Transparent & Flexible Electronics
MASSIMO MARRAZZO -
Transparent & flexible electronics
Nanotechnology VOL. I 2011 Massimo Marrazzo - biodomotica.com 1
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I n de x Nanotechnology Graphene Nanotubes Printed electronics Ink for "printed electronics" Printer for "printed electronics" Transparent and Strong Plastic Transparent Electronics Flexible and trasparent displays Electronic paper / E-paper / E-ink Printed battery Charging batteries without wires WiTricity Solar Energy Seebeck effect - Thermoelectric Printed Memory Printed Antennas Wireless technologies Nanotube Radio Sound Lens Bio-Sensors Virtual Muscles Gecko Mems Ecology Link to transparent electronics Applications of transparent or flexible electronics Invisibility Cloak Acronyms Books Journal Papers Links Show/Convention/Exposition Blogs Toolbox iPad & iPhone applications for Nanotech Android applications for read RSS Nanotech 2011 Update
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Nanotechnology - http://www.nano.org.uk/whatis.htm
What is Nanotechnology? Nanotechnology originates from the Greek word “nanos” meaning “dwarf". A nanometre is one billionth (10-9) of a metre, which is tiny, only the length of ten hydrogen atoms, or about one hundred thousandth of the width of a hair! Although scientists have manipulated matter at the nanoscale for centuries, calling it physics or chemistry, it was not until a new generation of microscopes were invented in the nineteen eighties in IBM, Switzerland that the world of atoms and molecules could be visualized and managed. In simple terms, nanotechnology can be defined as 'engineering at a very small scale', and this term can be applied to many areas of research and development: from medicine to manufacturing to computing, and even to textiles and cosmetics. It can be difficult to imagine exactly how this greater understanding of the world of atoms and molecules has and will affect the everyday objects we see around us, but some of the areas where nanotechnologies are set to make a difference are described below. From Micro to Nano Nanotechnology, in one sense, is the natural continuation of the miniaturization revolution that we have witnessed over the last decade, where millionth of a metre (10-6 m) tolerances (microengineering) became commonplace, for example, in the automotive and aerospace industries enabling the construction of higher quality and safer vehicles and planes. It was the computer industry that kept on pushing the limits of miniaturization, and many electronic devices we see today have nano features that owe their origins to the computer industry — such as cameras, CD and DVD players, car airbag pressure sensors and inkjet printers. ©2008 Institute of Nanotechnology
What is Nanotechnology? A basic definition: Nanotechnology is the engineering of functional systems at the molecular scale. This covers both current work and concepts that are more advanced. In its original sense, 'nanotechnology' refers to the projected ability to construct items from the bottom up, using techniques and tools being developed today to make complete, high performance products. The Meaning of Nanotechnology When K. Eric Drexler popularized the word 'nanotechnology' in the 1980's, he was talking about building machines on the scale of molecules, a few nanometers wide motors, robot arms, and even whole computers, far smaller than a cell. Drexler spent the next ten years describing and analyzing these incredible devices, and responding to accusations of science fiction. Meanwhile, mundane technology was developing the ability to build simple structures on a molecular scale. As nanotechnology became an accepted concept, the meaning of the word shifted to encompass the simpler kinds of nanometer-scale technology. The U.S. National Nanotechnology Initiative was created to fund this kind of nanotech: their definition includes anything smaller than 100 nanometers with novel properties.
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Four Generations Mihail (Mike) Roco of the U.S. National Nanotechnology Initiative has described four generations of nanotechnology development (see chart below). The current era, as Roco depicts it, is that of passive nanostructures, materials designed to perform one task. The second phase, which we are just entering, introduces active nanostructures for multitasking; for example, actuators, drug delivery devices, and sensors. The third generation is expected to begin emerging around 2010 and will feature nanosystems with thousands of interacting components. A few years after that, the first integrated nanosystems, functioning (according to Roco) much like a mammalian cell with hierarchical systems within systems, are expected to be developed.
ÂŠ 2002-2008 Center for Responsible Nanotechnology TM CRN is an affiliate of World CareÂŽ, an international, non-profit, 501(c)(3) organization.
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Transparent & Flexible Electronics - http://en.wikipedia.org/wiki/NanoNano- (symbol n) is a prefix in the metric system denoting a factor of 10−9 or 0.000000001. It is frequently encountered in science and electronics for prefixing units of time and length, such as 30 nanoseconds (symbol ns), 100 nanometres (nm) or in the case of electrical capacitance, 100 nanofarads (nF). The prefix is derived from the Greek νάνος, meaning "dwarf", and was officially confirmed as standard in 1960. In the United States, the use of the nano prefix for the farad unit of electrical capacitance is uncommon; capacitors of that size are more often expressed in terms of a small fraction of a microfarad or a large number of picofarads. When used as a prefix for something other than a unit of measure, as in "nanoscience", nano means relating to nanotechnology, or on a scale of nanometres. See nanoscopic scale.
Prefix yotta zetta exa peta tera giga mega kilo hecto deca deci centi milli micro nano pico femto atto zepto yocto
Symbol Y Z E P T G M k h da0 10 d c m ì n p f a z y
10n 1024 1021 1018 1015 1012 109 106 103 102 101 10-1 10-2 10-3 10-6 10-9 10-12 10-15 10-18 10-21 10-24
SI prefixes Decimal 1000000000000000000000000 1000000000000000000000 1000000000000000000 1000000000000000 1000000000000 1000000000 1000000 1000 100 10 1 0.1 0.01 0.001 0.000001 0.000000001 0.000000000001 0.000000000000001 0.000000000000000001 0.000000000000000000001 0.000000000000000000000001
Short scale Septillion Sextillion Quintillion Quadrillion Trillion Billion Million Thousand Hundred Ten One Tenth Hundredth Thousandth Millionth Billionth Trillionth Quadrillionth Quintillionth Sextillionth Septillionth
Long scale Quadrillion Trilliard Trillion Billiard Billion Milliard
Milliardth Billionth Billiardth Trillionth Trilliardth Quadrillionth
The International System of Units (SI) specifies a set of unit prefixes known as SI prefixes or metric prefixes. An SI prefix is a name that precedes a basic unit of measure to indicate a decadic multiple or fraction of the unit. Each prefix has a unique symbol that is prepended to the unit symbol. Name
Representative objects with this size scale
Height of a 7-year-old child.
Length of a bee.
10-2 10-3 10-6 10-9
Size of typical dust particles.
Radius of a Hydrogen Atom is about 23 pm.
Size of our palm.
Thickness of ordinary paperclip.
The diametre of a C60 molecule is about 1 nm.
Size of a typical nucleus of an atom is 10 fm. 10-18 Estimated size of an electron
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Graphene - http://en.wikipedia.org/wiki/Graphene
Graphene is a one-atom-thick planar sheet of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. It can be viewed as an atomic-scale chicken wire made of carbon atoms and their bonds. The name comes from GRAPHITE + ENE; graphite itself consists of many graphene sheets stacked together.
Graphene is an atomic-scale chicken wire made of carbon atoms.
Integrated circuits Graphene has the ideal properties to be an excellent component of integrated circuits. Graphene has a high carrier mobility, as well as low noise allowing it to be utilized as the channel in a FET. The issue is that single sheets of graphene are hard to produce, and even harder to make on top of an appropriate substrate. Researchers are looking into methods of transferring single graphene sheets from their source of origin (mechanical exfoliation on SiO2 / Si or thermal graphitization of a SiC surface) onto a target substrate of interest. In 2008, the smallest transistor so far, one atom thick, 10 atoms wide was made of graphene. Transparent conducting electrodes Graphene's high electrical conductivity and high optical transparency make it a candidate for transparent conducting electrodes, required for such applications as touchscreens, liquid crystal displays, organic photovoltaic cells, and OLEDs. In particular, graphene's mechanical strength and flexibility are advantageous compared to indium tin oxide, which is brittle, and graphene films may be deposited from solution over large areas.
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N a n otu be s -
3D model of three types of single-walled carbon nanotubes. Carbon nanotubes (CNTs) are allotropes of carbon with a nanostructure that can have a length-to-diameter ratio greater than 1,000,000. These cylindrical carbon molecules have novel properties that make them potentially useful in many applications in nanotechnology, electronics, optics and other fields of materials science. They exhibit extraordinary strength and unique electrical properties, and are efficient conductors of heat. Inorganic nanotubes have also been synthesized. Their name is derived from their size, since the diameter of a nanotube is in the order of a few nanometers (approximately 1/50,000th of the width of a human hair), while they can be up to several millimeters in length (as of 2008). Nanotubes are categorized as single-walled nanotubes (SWNTs) and multi-walled nanotubes (MWNTs).
- http://www.unidym.com/technology/about_carbon.html What are Carbon Nanotubes? Carbon nanotubes (CNTs) are tubular cylinders of carbon atoms that have extraordinary electrical, mechanical, optical, thermal, and chemical properties.
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Individual carbon nanotubes can conduct electricity better than copper, possess higher tensile strength than steel, and conduct heat better than diamond. In electronic applications, carbon nanotubes can possess higher mobilities than single crystal silicon. All this in a material that is over 10,000 times thinner than a human hair. There are multiple forms of carbon nanotubes, varying in diameter, length, and in the tendency of the nanotubes to form ropes and bundles of tubes. Some forms of carbon nanotubes are metallic and highly conducting; other forms are semiconducting, and can form the basis of electronic switches.
- http://www.unidym.com/technology/about_carbon_more.html CARBON NANOTUBES Carbon nanotubes (fullerene nanotubes) are part of the fullerene family of carbon materials discovered by Dr. Richard E. Smalley and colleagues in 1985. They include single-wall carbon nanotubes (SWNTs), and nested (endohedral or endotopic) SWNTs, i.e., one, two or more tubular fullerenes nested inside another tubular fullerene. Each tubular fullerene is a huge carbon molecule, often having millions of carbon atoms bonded together to form a tiny tube. Carbon nanotube diameters range from about 0.5 to about 10 nanometers (one nanometer = 10-9 meter) and their lengths are typically between a few nanometers and tens of microns (one micron = 10-6 meter).
Carbon is a truly remarkable atom. It readily bonds with itself into extended sheets of atoms comprising linked hexagonal rings shown below. Each carbon atom is covalently bonded to its three nearest neighbors.
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This unique sheet structure is called graphene. Solid graphite is made up of layers of graphene stacked as shown above. No other element in the periodic table bonds to itself in an extended network with the strength of the carbon-carbon bond, which is among the strongest of chemical bonds. Some of the electrons in the carbon-carbon bonds are free to move about the entire graphene sheet, rather than stay home with their donor atoms, giving the structure good electrical conductivity. The tight coupling between atoms in the carboncarbon bond provides an intrinsic thermal conductivity that exceeds almost all other materials. As suggested by the carbon nanotube figure above, the structure of a fullerene nanotube is that of a sheet of graphene, wrapped into a tube and bonded seamlessly to itself. This is a true molecule with every atom in its place and very few defects: an example of molecular perfection on a relatively large scale. The special nature of the bonded carbon sheet, the molecular perfection of carbon nanotubes, and their long tubular shape endow them with physical and chemical properties that are unlike those of any other material. These properties include high surface area, excellent electrical and thermal conductivity, and tremendous tensile strength, stiffness, and toughness. In a single tube, every atom is on two surfaces - the inside and the outside, and a single gram of nanotubes has over 2400 m2 of surface area! The nature of the carbon bonding gives the tubes their great tensile strength and electrical and thermal conductivity. The carbon nanotubes' stiffness and toughness derives from their molecular perfection. In most materials the actual observed stiffness and toughness are degraded very substantially by the occurrence of defects in their structure. For example, high strength steel typically fails at about 1% of its theoretical breaking strength. Carbon nanotubes, however, achieve values very close to their theoretical limits because of their perfection of structure - there are no structural defects where mechanical failures can begin! It is, however, the tubular geometry of carbon nanotubes that gives them their most exotic properties. Depending on the orientation of the graphene sheet forming the tube's wall, the tube can be either metallic or semiconducting. The metallic tubes conduct electricity just as metals do and the semiconducting ones have great promise as the basic elements of a new paradigm for electronic circuitry at the molecular level. Basic Structure There are literally hundreds of different carbon nanotube structures. One can identify these structures by thinking of the carbon nanotube as a sheet of graphene wrapped into a seamless cylinder. As one might imagine, there are many ways to wrap a graphene cylinder, and the cylinder can have a wide range of dimensions. Soon after fullerene nanotubes were discovered, a classification scheme was devised to describe the different conformations of graphene cylinders. This classification scheme uses an ordered pair of numbers, (n,m), and is based upon the diagram of graphene shown below. Each carbon atom in the graphene sheet is bonded to three other carbon atoms, forming a Y-shaped vertex of carbon-carbon bonds. In order to make a seamless graphene tube of a uniform diameter, one must wrap the graphene sheet in a way that permits every carbon atom in the cylinder to be bonded to three other carbon atoms where the sheet joins to itself. The number of ways this wrapping can be achieved is countable according to the numbering scheme given in the figure below. The unit vectors of the 2-dimensional graphene lattice are shown as a1 and a2 below. Each vertex that could possibly join to the origin during a wrapping operation is labeled with an ordered pair wherein the first number of the pair is the distance (in lattice repeat units) of the vertex from the origin along a1, and the second number is the distance of the vertex from the origin along a2.
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- http://www.unidym.com/technology/cnt_application_electronics.html Transparent Conductive Films One of the more amazing attributes of carbon nanotubes is that they can form films that are highly electrically conductive, but almost completely transparent. The film is only about 50 nanometers thick, and very porous. Under an electron microscope, the film is seen to be a just a few layers of endless carbon nanotube ropes. The films have an ideal conductivity for multiple types of touch screens which have applications including point-of-sale terminals, games, portable computers, cell phones, personal digital assistants and many others. The transparent films used initially for touch screens also reach any application that requires a large-area transparent conductor, including LCD displays, plastic solar cells, and organic LED lighting, and transparent carbon nanotube films have been demonstrated in the laboratory to be effective in all these areas.
Printable Transistors The semiconducting properties of carbon nanotubes can be exploited to create printable transistors with extremely high performance. Specifically, researchers have shown CNT-based transistors employing a sparse nanotube network to achieve mobilities of 1 cm2/V-s (Schindler et al., Physica E (2006), while those using an aligned array of single-walled nanotubes can reach as high as 480 cm2/V-s [Kang et al., Nature Nanotech. 2, 230 (2007)]. Nanotubes also prove to be useful additives to polymer-based TFTs and help to overcome some of the shortcomings of those devices. Beyond their performance, such devices are compatible with solutionbased printing techniques, which enable dramatic cost savings in such devices as LCDs and OLED-based displays. Field Emission Carbon nanotubes are the best field emitters of any known material. This is understandable, given their high electrical conductivity, and the unbeatable sharpness of their tip. If the tip is placed close to another electrode and a voltage is applied between the tube and electrode, a large electric field builds up near the tip of the tube. The magnitude of the electric field is inversely proportional to the radius of curvature of the tip. Thus the sharper the tip is, the larger the electric field. Even with only a few volts applied to an electrode a few microns away from the nanotube tip, electric fields in the range of a millions of Volts per centimeter will build up near the tip. These fields are large enough to pull a substantial number of electrons out of the tip. As "cold cathode" electron emitters, carbon nanotube films have been shown to be capable of emitting over 4 Amperes per square centimeter. Furthermore, the current is extremely stable [B.Q. Wei, et al. Appl. Phys. Lett. 79 1172 (2001)]. An immediate application of this behavior receiving considerable interest is in field-emission flat-panel displays. Instead of a single electron gun, as in a traditional cathode ray tube display, there is a separate electron gun for each pixel in the display. The high current density, low turn-on and operating voltage, and steady, long-lived behavior make carbon nanotubes ideal field emitters for this application. Other applications utilizing the field-emission characteristics of carbon nanotubes include: high-resolution x-ray sources, general cold-cathode lighting sources, high-performance microwave tubes, lightning arrestors, and electron microscope cathodes.
Integrated Circuits Nanotubes might also represent a solution to thermal management problems plaguing the semiconductor industry. As more and more transistors are packed on chips, microprocessors are getting hotter and noisier. The industry is searching for new types of heat sinks to control temperatures on chips. Nanotubes have tremendous thermal conductivity, and a number of firms are developing nanotube-based heat sinks. Due to the unique conducting and semiconducting properties of nanotubes, devices based on individual carbon nanotubes may eventually replace existing silicon devices. For example, several prototypes for future memory devices based on nanotubes have been demonstrated. In light of their high carrying capacity, nanotubes might replace copper interconnects in integrated circuits. Additionally, individual nanotubes have been shown to be superior to existing silicon transistors and diodes.
- http://thefutureofthings.com/news/1106/high-speed-carbon-nanotube-based-chips.html High Speed Carbon Nanotube Based Chips A team of electrical engineers from Stanford University and Toshiba have developed nanotube wires that can withstand data transfer speeds comparable to those of commercially available chips. In a paper published in the _Nano Letters" Journal, the researchers reported they had successfully used nanotubes to wire a silicon chip operating at the same speeds as today's processors.
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Silicon CMOS integrated circuit with Carbon nanotube interconnect. (Credit: Gael Close Stanford University) - Copyright ÂŠ 2008 The Future of Things.
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Printed electronics - http://en.wikipedia.org/wiki/Printed_electronics Printed electronics is a set of printing methods used to create electrical devices. Paper's rough surface and high water absorption rate has focused attention on materials such as plastic, ceramics and silicon. Printing typically uses common printing equipment, such as screen printing, flexography, gravure, offset lithography and inkjet. Electrically functional electronic or optical inks are deposited on the substrate, creating active or passive devices, such as thin film transistors or resistors. Printed electronics is expected to facilitate widespread, very low-cost, low-performance electronics for applications such as flexible displays, smart labels, decorative and animated posters, and active clothing that do not require high performance. The term printed electronics is related to organic electronics or plastic electronics, in which one or more inks are composed of carbon-based compounds. These other terms refer to the ink material, which can be deposited by solution-based, vacuum-based or some other method. Printed electronics, in contrast, specifies the process, and can utilize any solution-based material, including organic semiconductors, inorganic semiconductors, metallic conductors, nanoparticles, nanotubes, etc.
- http://alislab.com/research/sub01.html Printed electronics (also called electronic printing) is the term for a relatively new technology that defines the printing of electronics on common media such as paper, plastic using standard printing processes. This printing preferably utilizes common press equipment in the graphics arts industry, such as screen printing, flexography, gravure, contact printing and offset lithography. Instead of printing graphic arts inks, families of electrically functional electronic inks (conducting polymer, SWNT, insulator solution, etc) are used to print active devices, such as thin film transistors, electronic paper, and flexible displays. Printed electronics is expected to facilitate widespread and very low-cost electronics useful for applications not typically associated with conventional silicon based electronics, such as flexible displays, RF-ID tags, printing displays, and functional clothing.
- http://en.wikipedia.org/wiki/Conductive_polymer Conductive polymers or more precisely intrinsically conducting polymers (ICPs) are organic polymers that conduct electricity. Such compounds may have metallic conductivity or be semiconductors. The biggest advantage of conductive polymers is their processability. Conductive polymers are also plastics, which are organic polymers. Therefore, they can combine the mechanical properties (flexibility, toughness, malleability, elasticity, etc.) of plastics with high electrical conductivity.
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Transparent & Flexible Electronics The fabrication of electronic devices on plastic substrates has attracted considerable recent attention owing to the proliferation of handheld, portable consumer electronics. Plastic substrates possess many attractive properties including biocompatibility, flexibility, light weight, shock resistance, softness and transparency. Achieving high performance electronics or sensors on plastic substrates is difficult, because plastics melt at temperatures above 120 degrees C. Central to continued advances in high-performance plastic electronics is the development of robust methods for overcoming this temperature restriction. Unfortunately, high quality semiconductors (such as silicon) require high growth temperatures, so their application to flexible plastics is prohibited. A group of researchers at the California Institute of Technology now showed that highly ordered films of silicon nanowires can be literally glued onto pieces of plastic to make flexible sensors with state-of-theart sensitivity to a range of toxic chemicals. These nanowires are crystalline wires made out of doped silicon â€“ the mainstay of the computer industry. By etching nanowires into a wafer of silicon, and then peeling them off and transferring them to plastic, they developed a general, parallel, and scalable strategy for achieving high performance electronics on low cost plastic substrates.
Photograph of the flexible sensor chip (Image: Heath Group, Caltech) By Michael Berger, Copyright 2008 Nanowerk LLC
- http://www.gizmag.com/go/4749/picture/16223/ By Mike Hanlon September 15, 2005
First polymer electronic transistor produced completely by means of continuous mass printing technology. The finger structure of the source/drain electrodes can be seen, behind them lies the reddish semiconsuctor layer. The gate electrode lies invisibly behind the white insulator layer.
Source: [pmTUC] Institute for Print- und Media Technology http://www.tu-chemnitz.de/mb/PrintMedienTech/pminstitut_en/download_en.php
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Transparent & Flexible Electronics About Printed Electronics World Printed Electronics World provides you with a daily update of the latest industry developments. Launched in May 2007, this free portal covers the progress to printed electronics in all its forms - from transistor circuits to power, sensors, displays, materials and manufacturing. Hosted and written by IDTechEx, the leading printed electronics analyst and event organiser, articles provide commentary, analysis and give a balanced view of the issue. Copyright ÂŠ 2008 IDTechEx Ltd.
Flexible, biocompatible LEDs could light the way for next gen biomedicine By Ben Coxworth October 22, 2010
Researchers from the University of Illinois at Urbana-Champaign have created bio-compatible LED arrays that can bend, stretch, and even be implanted under the skin. While this might cause some people to immediately think _glowing tattoos!", the arrays are actually intended for activating drugs, monitoring medical conditions, or performing other biomedical tasks within the body. Down the road, however, they could also be incorporated into consumer goods, robotics, or military/industrial applications. Many groups have been trying to produce flexible electronic circuits, most of those incorporating new materials such as carbon nanotubes combined with silicon. The U Illinois arrays, by contrast, use the traditional semiconductor gallium arsenide (GaAs) and conventional metals for diodes and detectors.
An LED array, transfer printed onto the fingertip of a vinyl glove
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Bending with a folded piece of paper Last year, by stamping GaAs-based components onto a plastic film, Prof. John Rogers and his team were able to create the array's underlying circuit. Recently, they added coiled interconnecting metal wires and electronic components, to create a mesh-like grid of LEDs and photodetectors. That array was added to a pre-stretched sheet of rubber, which was then itself encapsulated inside another piece of rubber, this one being biocompatible and transparent. The resulting device can be twisted or stretched in any direction, with the electronics remaining unaffected after being repeatedly stretched by up to 75 percent. The coiled wires, which spring back and forth like a telephone cord, are the secret to its flexibility. The research was recently published in the journal Nature Materials.
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Transparent & Flexible Electronics - http://blog.targethealth.com/?p=14473
Roll-to-roll Plastic Displays Oct 22 2010
A new company puts silicon transistors on plastic for flexible displays
This plastic material is used as the backing for Phicotâ€™s amorphous silicon electronics. Credit: Phicot
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(see also Printed electronic)
- http://en.wikipedia.org/wiki/Organic_electronics Organic electronics, or plastic electronics, is a branch of electronics that deals with conductive polymers, plastics, or small molecules. It is called 'organic' electronics because the polymers and small molecules are carbon-based, like the molecules of living things. This is as opposed to traditional electronics which relies on inorganic conductors such as copper or silicon. Conductive polymers are lighter, more flexible, and less expensive than inorganic conductors. This makes them a desirable alternative in many applications. It also creates the possibility of new applications that would be impossible using copper or silicon. Organic electronics not only includes organic semiconductors, but also organic dielectrics, conductors and light emitters. New applications include smart windows and electronic paper. Conductive polymers are expected to play an important role in the emerging science of molecular computers. In general organic conductive polymers have a higher resistance and therefore conduct electricity poorly and inefficiently, as compared to inorganic conductors. Researchers currently are exploring ways of "doping" organic semiconductors, like melanin, with relatively small amounts of conductive metals to boost conductivity. However, for many applications, inorganic conductors will remain the only viable option. Organic electronics can be printed.
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Ink for “printed electronics” http://www.printelectronicnews.com/2820/epoxy-ink-for-printed-electronics/ Fine-Line Epoxy Ink Recommended for Printed Electronics Applications -
December 2nd, 2010
Creative Materials, Inc., introduces 125-26, an exceptional conductive ink for screen- printing circuits with fineline widths and spaces. Creative Materials is expanding its line of products for the printed electronics market. Our newest product, 125-26A/B119-44 is a flexible two-part epoxy ink that features superior adhesion to ITOcoated surfaces and other low surface-energy substrates. This product has been used successfully in printed electronics applications and is recommended where high-performance on coated substrates is necessary.
http://www.printelectronicnews.com/2732/new-film-technologies/ New film technologies for printed polymer electronics developed -
October 22nd, 2010
Conductive nano inks for flexible circuits Bayer MaterialScience develops conductive and formable nano inks for use in areas such as printed polymer electronics under the BayInk® name. These can be applied digitally using Depending on the process, it is possible to apply line widths with a resolution of less than 30 micrometers that are no longer visible to the human eye. This enables conductor tracks, contacts and electrodes to be applied much more easily and effectively than with conventional methods, which are mostly more complicated and more energy- and material-intensive. The inks ad here to a very wide range of plastic films such as Makrofol® and Bayfol® and other flexible materials, as well as to rigid substrates. The range of applications is wide – for example, as invisible conductor tracks they can be used to simplify the complex design of touchscreens. Customized service along the entire process chain.
- http://www.nanotech-now.com/news.cgi?story_id=36811 Conductive nano inks for printed electronics Leverkusen | February 17th, 2010
The two conductive inks BayInk® TP S and BayInk® TP CNT from Bayer MaterialScience have been developed primarily for use in the growing “printed electronics” market. These new inks boast excellent adhesion to plastic films, other flexible substrates, glass, silicon and indium tin oxide.
- http://www.nanowerk.com/news/newsid=16884.php Methode's Inkjet Printable Conductive Ink Allows Printing of Circuits on Polyester with No Secondary Curing June 24, 2010
(Nanowerk News) Methode Development Company, a business unit of Methode Electronics, Inc., announces that its conductive inkjet printable ink can now print circuits directly onto treated polyesters. The ink, formulated for thermal and piezo inkjet systems, makes it possible for engineers to print working electrical circuits, right from their desktops – facilitating product development, prototyping, and manufacturing processes. With this technology, scale-up for high volume manufacturing can be easily achieved.
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Transparent & Flexible Electronics - http://www.inktec.com/english/product_info/electronic_tec.asp Transparent Electronic Conductive TEC is the acronym of _Transparent Electronic Conductive," and one of the salient features of that TEC ink is its transparency at liquid phase. It means TEC is non-particle type ink before sintering and specially designed by InkTec, which is a world-class research and manufacturing company of inkjet applications. - http://nanotechweb.org/cws/article/tech/33180 Inkjet prints transparent CNT film. Transparent conductive film for use in displays is one of the headline applications for carbon nanotubes (CNTs). The interconnected material is seen as being more robust than today's ITO electrodes and could prove a popular choice for flexible devices, but the challenge is to bring down production costs.
- http://www.epson.co.jp/e/newsroom/news_2004_11_01.htm Epson Inkjet Technology Used to Fabricate World's First Ultra-Thin Multilayer Circuit Board. Epson recently succeeded in producing a 20-layer circuit board sample by using an inkjet system to alternately "draw" patterns and form layers on the board using two types of ink: a conductive ink containing a dispersion of silver micro-particles measuring from several nanometers to several tens of nanometers in diameter, and a newly developed insulator ink. Copyright ÂŠ 2008 SEIKO EPSON CORP
https://buffy.eecs.berkeley.edu/PHP/resabs/resabs.php?f_year=2005&f_submit=one&f_absid=100770 High-Performance All-Inkjet-Printed Transistors for Ultra-low-cost RFID Applications -
Dec 16, 2010 Alejandro De La Fuente Vornbrock, Steven Edward Molesa, David Howard Redinger and Steven K. Volkman (Professors Ali Niknejad and Vivek Subramanian) Semiconductor Research Corporation, Defense Advanced Research Projects Agency and National Science Foundation
Printed electronics will enable the development of ultra-low-cost RFID circuits for use as electronic barcodes, since it eliminates the need for lithography, vacuum processing, and allows the use of low-cost web manufacturing. Recently, there have been several demonstrations of printed transistors with mobilities approaching or exceeding 1 cm2/V-s; however, all such devices have been fabricated using silicon substrates with thermally grown oxides or using vacuum sublimated materials. In order to achieve ultra low cost, performance must be maintained without silicon substrates or vacuum processing.
- http://www.laserfocusworld.com/display_article/206960/12/none/none/Feat/Semiconductor-ink-advances-flexible-displays Semiconductor ink advances flexible displays The technique being developed fabricates devices using high-volume inkjet printing to replace the photolithographic techniques used to create the thin-film-transistor backplane circuits used in displays. A liquid-based organic semiconductor material, developed by Xerox researchers, is used to print the semiconductor channel layers for large-area transistor arrays.By Beng Ong - Research fellow and manager, Advanced Materials and Organic Electronics Group, Xerox Research Centre of Canada. Copyright ÂŠ 2007: PennWell Corporation, Tulsa, OK
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Printer for â€œprinted electronicsâ€? - http://www.ntera.com/technology/printing_processes.php Web-Fed (Roll-to-Roll) Printed NCD Displays on Flexible Substrate
Printing Processes NanoChromics Ink Systems are compatible with existing printing equipment and processes. Sheet or Web-fed Screen Printing Flexographic Printing Inkjet Printing Leveraging additive print processes, NanoChromics Ink Systems can be combined with other printed electronic technologies (and traditional graphics inks) on the same substrate. Compatibility with existing, widely available printing equipment minimizes capital investment for traditional graphics printers looking to expand into printed electronics and functional media.
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Transparent & Flexible Electronics - http://www.citala.com/index.php/flexible-display-technology/Roll-To-Roll-Manufacturing.html Roll To Roll Manufacturing Citala, US-based roll-to-roll (R2R) manufacturing is state-of-the art with a track record of reliability. Citala was one of the first companies to offer genuine R2R manufacturing, enabling the production of large, cost-effective quantities. R2R enables solutions for patterning, coating, cutting, and combining different layers of customizable displays. Citala can manufacture flexible displays and optical shutters using the same line.
Citala's R2R-schematic diagram - © Copyright 2008 Citala. All Rights Reserved
- http://www.xenoncorp.com/print_mkt.html PHOTONIC SINTERING OF NANOPARTICLE INKS ON LOW- TEMPERATURE SUBSTRATES: PULSED LIGHT EXCELS The world of printed electronics is moving out of R&D and into production, and new developments in materials—particularly nanoparticle inks and photonic curing from Xenon Corporation—are in the driver’s seat. Here’s what’s happening: 1.) Functionally conductive inks and coatings now contain nanoparticles that permit the use of low-cost substrates such as paper, PET and polyethylene films. 2.) New developments allow inkjets and screen printers to use silver, gold and most recently, lower-cost copper nanoparticle inks. 3.) It is now possible to print at room temperature on flexible substrates such as printed circuit boards. Here’s the photonic curing contribution: The challenge has long been heat. How do you sinter or anneal nanoparticle inks at substrate temperatures, which are typically below 160C? Xenon’s photonic pulsed light curing answers this challenge. High energy peak pulses, delivered in milliseconds, quickly heat only the inks and not the substrates. The high energy removes the solvent, leaving only the metal flakes which are sintered or annealed, while the substrate is unaffected. This speed allows copper inks to be sintered too quickly for a surface oxide layer to develop, so conductivity is improved. - http://www.oled-display.net/oled-inkjet-printing CDT is sole supplier of the Litrex range of Ink Jet. Cambridge Display Technology have also partnered industry leaders across the globe to offer a fully inclusive ink jet package. To support the Litrex printer range CDT can offer materials, print heads, know-how and skills development packages. More about OLED Inkjet Printing and PLED at http://www.cdtltd.co.uk 22 Massimo Marrazzo - biodomotica.com
Transparent & Flexible Electronics - http://www.litrex.com/index.asp?sect=5&page=12 The Litrex _ precision inkjet printer is a low-cost, compact system for research and development of OLED/LEP, LCD, printed electronics, and biomaterial applications. - http://www.dimatix.com/ Dimatix is driving a revolution in micro-production technology that will deliver a new generation of applications in imaging, electronics and the biosciences. http://www.dea.brunel.ac.uk/cleaner/Electronics_Projects/Handbook_1.htm Over four years research work at Brunel University has demonstrated the feasibility of manufacturing electrical circuit interconnect via the established printing technology of offset lithography. It has been shown that offsetlithography can be used as a process for manufacture of low specification electrical interconnect, leading to reduced production time and raw material use when compared to conventional thick film printing approaches.
ÂŠ 2008 Cleaner Electronics Research Group
Conventional and Lithographically printed circuit boards for telephone assembly. This demonstrator surpassed all others in complexity and processor speed.
- http://www.engr.uiuc.edu/news/index.php?xId=074108960714 'Nanonet' circuits closer to making flexible electronics reality By Emil Venere, Purdue University
Together, researchers at Illinois and Purdue have overcome a major obstacle in producing transistors from networks of carbon nanotubes, a technology that could make it possible to print circuits on plastic sheets for applications including flexible displays and an electronic skin to cover an entire aircraft to monitor crack formation.
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Transparent and Strong Plastic Strong, Light, Transparent Plastic - http://thefutureofthings.com/news/1060/strong-light-transparent-plastic.html
Researchers from the University of Michigan (UM) have developed a composite plastic, which they say is strong as steel, but much lighter and transparent. The scientists name several possible applications for their invention. The composite plastic could be used in the making of stronger and lighter armor for soldiers and police forces and for protecting their vehicles. The material could also be used in micro-electromechanical devices, in micro-fluidics and biomedical sensors, in valves, and in unmanned aircrafts. Copyright ÂŠ 2009 The Future of Things. All rights reserved
- http://www.trnmag.com/Photos/2008/033108/Flexible%20silicon%20circuits%20Image.html Flexible silicon Stretchable and bendable computer circuits made from ordinarily brittle single-crystal silicon promise flexible electronic devices that perform at nearly the same level as today's rigid computer chips. ÂŠ Copyright Technology Research News, LLC 2000-2008. All rights reserved.
- http://www.news.uiuc.edu/news/08/0327electronics.html Foldable and stretchable, silicon circuits conform to many shapes
- http://www.wisegeek.com/what-is-the-difference-between-silicon-and-silicone.htm Difference Between Silicon and Silicone
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Transparent Electronics - http://www.indiastudychannel.com/resources/98936-Transparent-Electronics-or-Invisible-Electronics.aspx Transparent Electronics -- or Invisible Electronics Dec 2009 By Pratima
Transparent electronics is a emerging technology, which is satisfying the requirements of everything invisible or multi-purpose objects. What is Transparent Electronics? Its just Technology for next generation of optoelectronic devices and employs wide band-gap semiconductors for the realization of invisible circuits. Oxide semiconductors are very interesting materials because they combine simultaneously high/low conductivity with high visual transparency. How it works? Transparent oxide semiconductor based transistors have recently been proposed using as active channel intrinsic zinc oxide (ZnO). The main advantage of using ZnO deals with the fact that it is possible to growth at/near room temperature high quality polycrystalline ZnO, which is a particular advantage for electronic drivers, where the response speed is of major importance. Besides that, since ZnO is a wide band gap material (3.4 eV), it is transparent in the visible region of the spectra and therefore, also less light sensitive. Applications: They have been widely used in a variety of applications like: 1.antistatic coatings 2.touch display panels 3.solar cells, 4.flat panel displays 5.heaters 6.defrosters 7.optical coatings etc
- http://kn.theiet.org/magazine/issues/1009/transparent-electronics-1009.cfm Transparent electronics look to use in smart objects June 2010 By Chris Edwards
Transparent electronic materials will make it possible to build a new generation of smart objects. After crash-landing on Mars in the 2000 movie 'Red Planet', Val Kilmer tries to work out where he and his team have wound up on the surface. So, he unrolls a see-through computer that tries to match the local landscape with the images collected by scores of unmanned Mars probes over the years. It was a bomb at the box office. Ten years on, 'Red Planet' is not showing much sign of becoming a cult classic and ultimately profitable like 'Blade Runner'. But it's still inspiring engineers to work out how to make a roll-up, see-through map. Tolis Voutsas, director of the materials and devices applications lab at Sharp Laboratories of America, says: ''Red Planet' was shown in 2000. And we still don't have technology to do this. But thanks to Hollywood we still have the vision.' Director Antony Hoffman reckoned it might take a while to realise the transparent map. 'Red Planet' was set in 2056. Engineers such as Chris Bower, principal scientist at Nokia's research centre in Cambridge, are hoping that they can develop something similar much more quickly. Working on morph A couple of years ago, Nokia unveiled what it called the Morph concept. A set of videos showed what the portable computer and phone of the future might look like. Bower explained the idea at the Printed Electronics conference in Dresden in April: 'You can take a standard candy-bar phone and transform it. You can wrap it around your wrist so that it becomes a wearable device. 'We are working hard to enable the Morph concept. We are trying to build a library of functional surface materials that provide the ability to change colour or haptic feedback. We also need compliancy to reshape Massimo Marrazzo - biodomotica.com 25
Transparent & Flexible Electronics the device, with flexible and even stretchable displays. And transparency is something we require,' says Bower, showing a Photoshop-assisted mockup of Nokia's take on the transparent navigator. The roll-up map is not the only applications for see-through electronics. Douglas Keszler of Oregon State University, a leading researcher into transparent metal oxides, reckons these materials will find uses in car dashboards and windows to provide extra real estate for computer circuits. Carbon nanotubes and plastics are vying with metal oxides for a role in transparent electronics, but the metals have a solid lead historically. 'We believe metal oxides can enable transparent electronics and they have been around for some time,' says Flora Li, research associate at the University of Cambridge. In the Second World War, aircraft makers used transparent conductive oxides to deliver heat to windshields to keep them free of ice. Indium tin oxide (ITO) has become the one material that appears almost everywhere as a conductive coating for flat-screens and touchscreens. Unfortunately, the key component, indium, is a very rare and expensive metal, giving researchers a strong incentive to find other options. Peter Harrop, chairman of analyst firm IDTechEx, says: 'It's a defeat that indium tin oxide is still used for transparent electronics. There are replacements but they need to gain traction. That is a big opportunity for a lot of people.' Li says ITO represents the first generation of transparent electronics, forming just passive conductors on the surface of screens. 'The phase we are in now, we consider the second generation, allowing us to fabricate discrete transparent components,' she claims. The coming third generation will put active transparent components into many more devices. Thin-film transistors made out of metal oxides date back to the the 1960s but it's only since the late 1990s that research has shown that it is possible to create a library of standard components that you can see through. Keszler points to a paper on the creation of a p-type transistor by Hiroshi Kawazoe and colleagues at the Tokyo Institute of Technology in 1997 as the birth of modern transparent electronics. Up to that point, all the conductors were n-type. With the two types available, it became feasible to build thin-film diodes and transistors. There is a reason why transparent metal oxides are not more widely used in electronics. As with the organic polymers used in printed electronics, electrons do not move easily through most of them. According to Keszler, the best materials have a conductivity more than ten times worse than the contact metals used today in silicon chips. Li says even with this lower performance, there is still a useful role for these devices. She compares metal oxides to lower-grade forms of silicon used in flat-panel displays, such as polycrystalline and amorphous, non-crystalline silicon, often called alpha-silicon. 'Polysilicon gives you great mobility. But you need to use really high temperatures to get this. Alpha-silicon you can make at much lower temperatures but at the expense of lower mobility. This is where we believe transparent metal oxides fit in: filling a gap between organic materials and alpha-silicon in terms of cost and performance,' says Li. Whereas alpha-silicon generally has a mobility of around 1cm/Vs, researchers have managed to achieve around 30cm'/Vs for the widely available material zinc oxide, which is still five times lower than the polysilicon used in high-end displays but is usable. Mobility is only one of the concerns that researchers have with metal oxides. Sharp worked with startup Inpria, which Keszler co-founded, on indium gallium zinc oxide transistors. 'However, the current doesn't saturate,' says Voutsas, in the way that it should for a workable transistor. 'And the threshold voltage is high. That is why you don't see a product that uses amorphous-oxide TFTs.' As with the the transistor, researchers are working with a range of metals in the hope of finding combinations that work. Li says many of these materials are binary oxides that are difficult to produce reliably using sputtering - the balance between the two metals in the oxide varies, disrupting its ability to conduct electricity.
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Transparent & Flexible Electronics Like silicon-based processes, the metals can migrate into other layers, which Li found with indium zinc oxide and hafnium oxide gates. 'We found the indium migrated into the hafnium layer and destroyed the device. What we found really works with indium zinc is aluminium,' says Li. On the other hand, zinc oxides seem to work well with hafnium oxide. With work continuing on indium-based oxides, materials scientists have yet to find a genuine low-cost, easily available winner in transparent conductive oxides. 'But we think that this is one of the technologies that will emerge soon,' Voutsas concludes.
- http://www.technologyreview.com/computing/21964/?a=f High-quality, clear graphene films are a leap toward bendable OLED displays. Korean researchers have found a way to make large graphene films that are both strong and stretchy and have the best electrical properties yet. Prachi Patel-Predd - © 2009 - .technologyreview.com
© 2009 Ji Hye Hong - http://www.sciencenews.org/view/access/id/39865/title/Graphene_from_gases_for_new,_bendable_electronics_
Graphene from gases for new, bendable electronics Flexible, translucent and ultrathin, layers of carbon atoms called graphene are also excellent electrical conductors that could find use in flexible computer displays, molecular electronics and new wireless communications. Making high-quality graphene sheets is usually a slow, painstaking process, but now several research groups have discovered ways to make patterned graphene circuits using techniques borrowed from microchip manufacturing, which can be scaled up for mass production. By Patrick Barry - ©2009 - .sciencenews.org
- http://chem.skku.edu/graphene/ SKKU Graphene Research Laboratory
- http://www.nanowerk.com/spotlight/spotid=8787.php New work at the University of Southern California (USC) has now demonstrated the great potential of massively aligned single-walled carbon nanotubes for high-performance transparent electronics. "We fabricated transparent thin-film transistors on both rigid and flexible substrates with transfer printed aligned carbon nanotubes as the active channel and indium-tin oxide as the source, drain, and gate electrodes," Chongwu Zhou, Jack Munushian Associate Professor in USC's Department of Electrical Engineering, tells Nanowerk. "We have fabricated these transistors through low-temperature processing, which allowed device fabrication even on flexible substrates." By Michael Berger. Copyright 2008 Nanowerk LLC
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Transparent & Flexible Electronics - http://pubs.acs.org/doi/pdf/10.1021/nn800434d Transparent Electronics Based on Transfer Printed Aligned Carbon Nanotubes on Rigid and Flexible Substrates Fumiaki N. Ishikawa, Hsiao-kang Chang, Koungmin Ryu, Po-chiang Chen, Alexander Badmaev, Lewis Gomez De Arco, Guozhen Shen and Chongwu Zhou* Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089 ACS Nano, Article ASAP DOI: 10.1021/nn800434d Publication Date (Web): December 10, 2008
Report high-performance fully transparent thin-film transistors (TTFTs) on both rigid and flexible substrates.
http://www.eurekalert.org/pub_releases/2008-12/uosc-urp121608.php USC researchers print dense lattice of transparent nanotube transistors on flexible base It's a clear, colorless disk about 5 inches in diameter that bends and twists like a playing card, with a lattice of more than 20,000 nanotube transistors capable of high-performance electronics printed upon it using a potentially inexpensive low-temperature process. Its University of Southern California creators believe the prototype points the way to such long sought after applications as affordable "head-up" car windshield displays. The lattices could also be used to create cheap, ultra thin, low-power "e-paper" displays. ÂŠ2008 www.eurekalert.org
- http://www.nanowerk.com/spotlight/spotid=2062.php Transparent and flexible electronics with nanowire transistors Thin-film transistors (TFTs) and associated circuits are of great interest for applications including displays, large-area electronics and printed electronics (e.g. radio-frequency identification tags - RFID). Wellestablished TFT technologies such as amorphous silicon and poly-silicon are well-suited for many current applications - almost all mobile phone color screens use them - but face challenges in extensions to flexible and transparent applications. In addition, these TFTs have modest carrier mobilities, a measure of the velocity of electrons within the material at a given electric field. The modest mobility corresponds to a modest operating speed for this class of TFTs. Organic TFTs are generally better suited for flexible applications, and can be made transparent. However, mobilities in organic TFTs are generally quite low, restricting the speed of operation and requiring relatively large device sizes. Researchers at Purdue University, Northwestern University, and the University of Southern California now have reported nanowire TFTs that have significantly higher mobilities than other TFT technologies and therefore offer the potential to operate at much higher speeds. Alternatively, they can be fabricated using much smaller device sizes, which allows higher levels of integration within a given chip area. They also provide compatibility with a variety of substrates, as well as the potential for room-temperature processing, which would allow integration of the devices with a number of other technologies (e.g. for displays). "We have demonstrated fully-transparent thin-film transistors (TFTs) on both glass and flexible plastic substrates" Dr. David B. Janes tells Nanowerk.
Image of NWTs on a plastic substrate, showing the optical clarity and mechanical flexibility. Arrows point to the transistor array regions (Image: Dr. Janes) 28 Massimo Marrazzo - biodomotica.com
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The Clear Future of Electronics: Transparent Memory Device A group of scientists at Korea Advanced Institute of Science and Technology (KAIST) has fabricated a working computer chip that is almost completely clear -- the first of its kind. The new technology, called transparent resistive random access memory (TRRAM), is described in this week's issue of the journal Applied Physics Letters, which is published by the American Institute of Physics. 11.12.2008 - http://www.nanowerk.com/spotlight/spotid=1858.php Electronics can be so transparent One of the newly emerging areas of semiconductor technology is the field of transparent electronics. These thin-film materials hold the promise of a new class of flexible and transparent electronic components that would be more environmentally benign than current electronics. However, the emerging transparent electronics technology is facing manufacturing problems: current fabricating processes do not separate the device manufacturing from material synthesis. The transparent electronic materials, which are largely inorganic oxides. are directly deposited on the device substrate under harsh conditions which may cause damage to the existing layer or flexible substrate. The etching of small dimension oxide multilayer is also difficult due to the low selectivity of the etching recipe. New research results demonstrate that nanofabrication techniques could solve these problems. A group of researchers from Clarkson University and Pacific Northwest National Laboratory report that clear nanocrystals can serve as the appropriate electronic materials in the transparent device. "The purpose of our work is to demonstrate the fabrication of transparent devices using nanofabrication and nanomaterials" Dr. Feng Hua tells to Nanowerk. By Michael Berger, Copyright 2008 Nanowerk LLC
- http://techon.nikkeibp.co.jp/article/HONSHI/20071024/141211/ Transparent Electronic Products Soon a Reality Since the arrival of low-cost transparent transistors, R&D into transparent electronics has progressed rapidly. It will soon be possible, for instance, to embed transparent electronic circuits into large areas like windows, enabling the display of video imagery. Copyright ÂŠ 1995-2008 Nikkei Business Publications, Inc.
- http://dx.doi.org/doi:10.1038/nnano.2007.151 By Michael Berger, Copyright 2008 Nanowerk LLC
- http://nanoarchitecture.net/article/nanotubes-enable-flexible-transparent-electronics Nanotubes Enable Flexible, Transparent Electronics Flexible electronics have taken an important leap forward with the development of a new type of flexible, transparent electrode made using carbon nanotubes (CNTs). Jackson State University researchers made the electrode by applying boron-doped CNTs to glass and polymer film surfaces. The devices are 89% transparent to visible light and are robust; they maintain their conducting properties even after being folded and exposed to harsh environmental conditions.
- http://www.azom.com/News.asp?NewsID=7446 Invisible Electronics Northwestern University researchers report that by combining organic and inorganic materials they have produced transparent, high-performance transistors that can be assembled inexpensively on both glass and plastics.
- http://npl.postech.ac.kr/?mid=Trans_Electronic Advanced Display Nanodevice Transparent Thin film transistor(TFT) - http://oregonstate.edu/dept/ncs/newsarch/2006/Feb06/license2.htm OSU Licenses New Transparent Electronics to HP Scientists and engineers at Oregon State University have developed a new class of materials that can be used to create safe, inexpensive and transparent electronic circuits, and licensed the exclusive rights to develop and market products based on this technology to HP. Massimo Marrazzo - biodomotica.com 29
Transparent & Flexible Electronics
Flexible and trasparent displays For more info about this please see: Nanotechnology vol.2 Technology for E-books Readers (B/W & colors display) www.biodomotica.com/public/e-paper_e-book.pdf
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Electronic paper / E-paper / E-inkď›š For more info about this please see: Nanotechnology vol.2 Technology for E-books Readers (B/W & colors display) www.biodomotica.com/public/e-paper_e-book.pdf
by Emily Cooper - http://www.cooperhawk.com/contact.htm
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Printed battery - http://www.gizmag.com/worlds-smallest-battery-created/17237/ World’s smallest battery created By Darren Quick December 2010
Nano Battery A tin oxide anode contorts in response to ions flowing in as the battery charges. Sandia Labs http://www.popsci.com/science/article/2010-12/lithium-ion-batteries-swell-and-contort-while-charging-new-study-shows
Because battery technology hasn’t developed as quickly as the electronic devices they power, a greater and greater percentage of the volume of these devices is taken up by the batteries needed to keep them running. Now a team of researchers working at the Center for Integrated Nanotechnologies (CINT) is claiming to have created the world’s smallest battery, and although the tiny battery won’t be powering next year’s mobile phones, it has already provided insights into how batteries work and should enable the development of smaller and more efficient batteries in the future. The tiny rechargeable, lithium-based battery was created by a team led by Sandia National Laboratories researcher Jianyu Huang. It consists of a bulk lithium cobalt cathode three millimeters long, an ionic liquid electrolyte, and has as its anode a single tin oxide (Sn02) nanowire 10 nanometers long and 100 nanometers in diameter – that’s one seven-thousandth the thickness of a human hair. Because nanowire-based materials in lithium-ion batteries offer the potential for significant improvements in power and energy density over bulk electrodes the researchers wanted to gain an understanding of the fundamental mechanisms by which batteries work. They therefore formed the battery inside a transmission electron microscope (TEM) so they could study the charging and discharging of the battery in real time and at atomic scale resolution. By following the progression of the lithium ions as they travel along the nanowire, the researchers found that during charging the tin oxide nanowire rod nearly doubles in length. This is far more than its diameter increases and could help avoid short circuits that may shorten battery life. This unexpected finding goes against the common belief of workers in the field that batteries swell across their diameter, not longitudinally. “Manufacturers should take account of this elongation in their battery design,” Huang said. “These observations prove that nanowires can sustain large stress (>10 GPa) induced by lithiation without breaking, indicating that nanowires are very good candidates for battery electrodes,” he added. Atomic-scale examination of the charging and discharging process of a single nanowire had not been possible before because the high vacuum in a TEM made it difficult to use a liquid electrolyte. Huang’s group overcame this problem by demonstrating that a low-vapor-pressure ionic liquid – essentially molten salt – could function in the vacuum environment. This means that although the work was carried out using tin oxide nanowires, Huang says the experiments could be extended to other materials systems, either for cathode or anode studies. “The methodology that we developed should stimulate extensive real-time studies of the microscopic processes in batteries and lead to a more complete understanding of the mechanisms governing battery performance and reliability,” he said. “Our experiments also lay a foundation for in-situ studies of electrochemical reactions, and will have broad impact in energy storage, corrosion, electrodeposition and general chemical synthesis research field.” The research team’s work is reported in the December 10 issue of the journal Science.
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Transparent & Flexible Electronics http://www.energyharvestingjournal.com/articles/printed-lithium-reshaping-battery-00002104.asp Energy Scavenging, Power Scavenging - Making small electronic and electric devices self-sufficient -
Mar 2010 | Japan
Printed lithium reshaping battery
In February 2010, ITSUBO Advanced Materials Innovation Center and Hatanaka Electric in Japan announced a large area printed lithium polymer battery that can be reshaped as shown in the pictures. This is the statement from Mie Prefecture Industrial Support Center for the Promotion of Education and Science, Ministry of Industry-Academia Collaboration Urban Areas (a development in the Mie Ise Bay area). "This development of advanced materials and innovation creates a new generation all-solid polymer lithium secondary battery. It is a world first because the all-solid polymer lithium secondary battery employs a printing process. This battery, involving new electrode material and electrode interface control technology and a new polymer electrolyte, plus a separator, avoids the safety and reliability challenges of manufacturing polymer electrolyte lithium ion secondary batteries. A safe, thin, bendable, large area battery has resulted, which offers ease of stacking. Such batteries are welcome as the printed electronics sector is expected to grow rapidly. Development of this cell is continuing at the Principal Research and Development Center for Next Generation Batteries, Mie University, Mie Prefecture Industrial Research Institute (Kinseimatekku Co., Ltd., Kurehaerasutoma Co., Ltd., Shin-Co., Ltd., Toppan Printing Co., Ltd., Myeongseong Chemical Co., Ltd.). It has been jointly conducted by the government and academia."
Photos prototype polymer lithium secondary batteries Prototype battery performance "Cell size A6 (external dimension), cell thickness 450Âľm (external dimension) Initial charge and discharge efficiency of 99% Initial capacity of 45mAh (electrode material utilization efficiency of 80%) Operating voltage 1.8 V (voltage at 50% depth of discharge) Discharge rate of 0.02C ~ 1.0C of more than 100 cycle times (the current ongoing evaluation) Operating Temperature 0 ~ 25 CÂ°
In future, we will dramatically improve the performance of the battery cell structure design and optimization of polymer electrolyte interface control electrode materials." Second generation lithium batteries that are safer and have better performance are incorporated in the Lightning Car Company's Lightning sports car, the KleenSpeed Technologies 200mph Formula One car, the Hawkes Ocean Technologies Deepflight submarines, the PC-Aero pure electric aircraft etc. but even more powerful batteries will be welcome. For more read : Energy Harvesting and Storage for Electronic Devices 2009-2019
- http://newenergyandfuel.com/http:/newenergyandfuel/com/2010/01/08/printing-lithium-ion-batteries/ Printing Lithium Ion Batteries January 2010
The Advanced Materials Innovation Center (AMIC) of MIE Industry and Enterprise Support Center, a Japanbased foundation, has developed a lithium polymer battery that can be manufactured by printing technology.
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Printed Lithium Ion Sheet Battery. The research group used a normal sheet-shaped flexible substrate but employed a printing technology that can be applied to roll-to-roll production. When a roll-to-roll production method is used, the thickness of the flexible substrate can be reduced, enabling the manufacturing of thin batteries.
Printed Lithium Ion Sheet Battery Side View. Quite thin. There are two battery prototypes. One has an output voltage of about 4V at room temperature while the other has an output voltage of about 2V. The thickness of the battery is about 500µm, or 500 microns – that’s a halfmillimeter. Its negative and positive electrodes were formed on a flexible substrate by using printing technology. The AMIC isn’t disclosing the battery capacity. That could be disappointing, but the point is to get something small and light for something small and light. Such things at this point in time aren’t going to have huge power demands, yet. The AMIC says it did not use a printing technology to package the polymer electrolyte for the prototypes. Nor did they disclose the details of the polymer electrolyte or the negative or positive electrode materials. But the design and production by using printing technology offers reduced thickness, increased surface areas and laminated construction. Using a roll-to-roll production, costs can be reduced, and reducing costs for lithium technology is going to be a paramount concern. The sheet-shaped battery is being researched to be used with a flexible solar cell and be attached to a curved surface. If the battery is integrated with a solar cell formed on a flexible substrate, it is possible to build a sheet that can be used both as a power generator and as power storage. The effort is a three-year project that will end in March 2011. During the coming year, the research group plans to improve manufacturing technologies for commercial production, determine potential applications for the battery and set out the targets such as battery capacity. Having the construction technology for simply sheets of batteries might open far larger fields of uses. The capacity issue is of some concern, but 4 volts, using simple printing to construct the battery internal parts has to have a serious impact over time as the various anode and cathode materials are adapted to the assorted construction methods. The lithium polymer battery is being developed in a research project of MIE Industry and Enterprise Support Center with the partners of Toppan Printing Co Ltd., Shin-Kobe Electric Machinery Co. Ltd, Kureha Elastomer Co. Ltd., Kinsei Matec Co. Ltd., Meisei Chemical Works Ltd., MIE University, Suzuka National College of Technology and MIE Prefecture Industrial Research Institute. Massimo Marrazzo - biodomotica.com 35
Transparent & Flexible Electronics One has to think now that seeing something much lower in cost and simpler to manufacture will push research for thinner and lighter substrates, innovations in the anode and cathode materials and some clever electrolyte application processes. This research bodes well for the future of lithium batteries. Still quite expensive, lithium needs to get the manufacturing costs down. Perhaps printing is the path, and at 4 volts per cell, a compelling one indeed.
- http://news.cnet.com/8301-11128_3-20004170-54.html by Martin LaMonica May 2010
CAMBRIDGE, Mass.--Scientists at the Massachusetts Institute of Technology have successfully coated paper with a solar cell, part of a suite of research projects aimed at energy breakthroughs. Susan Hockfield, MIT's president, and Paolo Scaroni, CEO of Italian oil company Eni, on Tuesday officially dedicated the Eni-MIT Solar Frontiers Research Center. Eni invested $5 million into the center, which is also receiving a $2 million National Science Foundation grant, said Vladimir Bulovic, the center's director. The printed solar cells, which Bulovic showed at a press conference Tuesday, are still in the research phase and are years from being commercialized. However, the technique, in which paper is coated with organic semiconductor material using a process similar to an inkjet printer, is a promising way to lower the weight of solar panels. "If you could use a staple gun to install a solar panel, there could be a lot of value," Bulovic said.
Vladimir Bulovic, director of the Eni-MIT Solar Frontiers Research Center, holds a solar cell printed onto a piece of paper to spell MIT. This is the first paper solar cell, according to MIT and Eni. (Credit: Martin LaMonica/CNET)
The materials MIT researchers used are carbon-based dyes and the cells are about 1.5 percent to 2 percent efficient at converting sunlight to electricity. But any material could be used if it can be deposited at room temperature, Bulovic said. "Absolutely, the trick was coming up with ways to use paper," he said. MIT professor Karen Gleason headed the research and has submitted a paper for scientific review but it has not yet been published. MIT and Eni said this is the first time a solar cell has been printed on paper. During the press conference, Scaroni said that Eni is funding the center because the company understands that hydrocarbons will eventually run out and believes that solar can be a replacement. At the same time, he said, current technologies are not sufficient. "We are not very active (in alternative energy) today because we don't believe today's technologies are the answer of our problems," he said. Quantum dots The paper solar cells are one of many avenues being pursued around nanoscale materials at the Eni-MIT Solar Frontiers Center. Layers of these materials could essentially be sprayed using different manufacturing techniques to make a thin-film solar cell on a plastic, paper, or metal foils. 36 Massimo Marrazzo - biodomotica.com
Transparent & Flexible Electronics Silicon, the predominant material for solar cells, is durable and is made from abundant materials. Many companies sell or are developing thin-film solar cells, which are less efficient but are cheaper to manufacture. During a tour, Bulovic showed one of the center's labs, where researchers use a laser to blast light at nanomaterials for picoseconds. A picosecond is one trillionth of a second. The laser provides data on how the light excites electrons in the material, which will provide clues as to whether it will make a good solar cell material, he explained. MIT is focusing much of its effort on quantum dots, or tiny crystals that are only a few nanometers in size. A human hair is about 50,000 to 100,000 nanometers thick. By using different materials and sizes, researchers can fine-tune the colors of light that quantum dots can absorb, a way of isolating good candidates for quantum dot solar cells. Researchers at the center are also looking at different molecules or biological elements which can act as solar cell material. These cheap thin-film materials can be used on their own or added to silicon-based solar panels to enhance the efficiency, Bulovic said. If 0.3 percent of the U.S. were covered with photovoltaics with 10 percent efficiency, solar power could produce three times the country's needs, including a transition to electric vehicles, Bulovic said. For example, the easement strip on highways could be coated with material that could capture energy from the sun. But don't expect a revolution in solar power tomorrow. "I'm giving you a whole bunch of hype," Bulovic said while explaining solar's potential during the tour. "It usually takes 10 years from the time between when you invent something and you commercialize it." He estimated that many of the technologies in the labs were in the first three years of a five-to-seven-year development cycle
- http://laptopreviewshop.com/flexible-li-ion-battery.html Flexible Li-Ion battery Mircea / September 2010
Stanford scientists created a new flexible Li-Ion battery that’s as slim as a piece of paper and can easily bend.
Researchers from Stanford invented a very slim rechargeable Lithium-Ion battery (it’s only 300 µm thick) that can easily bend. Scientists Liangbing Hu, Hui Wu and Yi Cui managed to transform a simple piece of paper into a functional flexible battery. The piece of paper was covered on both sides with a layer of nano-tubes and a lithium compound. The lithium compound works as electrodes, while the nano-tubes collect and store electrical energy. The piece of paper separates the electrodes and keeps the whole thing together. Following tests, these batteries endured 300 charges flawlessly. This technology can easily be applied in paper-based electronics, an area that’s constantly evolving. Also, this technology can be used to store electrical energy, as Rice University professor Pulickel M. Ajayan states: “Such simple fabrication techniques could prove useful for integrating other nanomaterials for building the next generation of energy-storage devices.”
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Transparent & Flexible Electronics - http://winarco.com/ultra-thin-flexible-secondary-lithium-ion-paper-batteries-by-standford-university-researchers/ Ultra-thin Flexible Secondary Lithium-ion Paper Batteries by Standford University Researchers by Kevin Xu on September 2010
First we saw Flexible e-ink display and at the middle of this month Sony also introduces Flexible Electronic Paper display and recently the Department of Materials Science and engineering, Stanford University researchers has showing their new Innovation of Ultra-thin Flexible Secondary Lithium-ion Paper Batteries. The Standford University Researcher is using paper as separators and free-standing carbon nanotube thin films as both current collectors. The current collectors and Li-ion battery materials are integrated onto a single sheet of paper through a lamination process.
This new prototypes have been tested to be able to recharge up to 300 times without any problems. If the researcher able to bring their product to the surface, it will be a great contribution for our future batteries.
- http://pubs.acs.org/doi/abs/10.1021/nn1018158 Thin, Flexible Secondary Li-Ion Paper Batteries Liangbing Hu†, Hui Wu†, Fabio La Mantia, Yuan Yang, and Yi Cui* Department of Materials Science and Engineering, Stanford University, Stanford, California 94305 ACS Nano, 2010, 4 (10), pp 5843–5848 DOI: 10.1021/nn1018158 Publication Date (Web): September 13, 2010 Copyright © 2010 American Chemical Society
There is a strong interest in thin, flexible energy storage devices to meet modern society needs for applications such as interactive packaging, radio frequency sensing, and consumer products. In this article, we report a new structure of thin, flexible Li-ion batteries using paper as separators and free-standing carbon nanotube thin films as both current collectors. The current collectors and Li-ion battery materials are integrated onto a single sheet of paper through a lamination process. The paper functions as both a mechanical substrate and separator membrane with lower impedance than commercial separators. The CNT film functions as a current collector for both the anode and the cathode with a low sheet resistance (5 Ohm/sq), lightweight (0.2 mg/cm2), and excellent flexibility. After packaging, the rechargeable Li-ion paper battery, despite being thin (300 µm), exhibits robust mechanical flexibility (capable of bending down to <6 mm) and a high energy density (108 mWh/g).
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Transparent & Flexible Electronics - http://www.powerpaper.com/ Power Paper's printable, environment-friendly battery technology. Power Paper pioneered the industry's first printable thin and flexible batteries over 10 years ago, and today its batteries and integration technologies enable a vast range of products for consumer, medical, and industrial applications. ©2008 Power Paper Ltd.
- http://www.powerpaper.com/?categoryId=33405 Power Paper
Specifications Power Paper has developed a number of standard clean printed batteries for use in a variety of products and applications. Currently, the company does not offer its thin batteries as stand-alone products, however, manufacturers interested in integrating Power Paper's thin printed batteries into their own products, or engaging in joint development projects, please see partnership opportunities or contact us. The general specifications for Power Paper’s current generation of batteries are as follows: Primary cell (multiple cell battery packs are possible) 1.5V Typical thickness (total) 0.7 mm Bending radius 2.5cm (1 inch) Nominal continuous current density (per active area) 0.1 mA/cm 2 Nominal capacity (per active area) 4.5 mAh/cm 2 Nominal internal resistance (1kHz impedance) 50 Ohm max Shelf life 3 years Temperature operating range -20°C to +60°C
http://www.bluesparktechnologies.com/index2.html Blue Spark UT (Ultra-Thin) Series The UT Series is the industry’s thinnest printed battery currently in production, with a 30 percent slimmer laminate profile (as thin as 500 microns ~ 0.020 in). The batteries are extremely flexible and durable, even under high duty levels, and offer the same “green” advantages as the ST Series. UT batteries are available in a variety of shapes and sizes. Typical standard form factors are 1.5V, capable of delivering approximately 12 mAh of energy, with peak drain currents of at least 1 mA. Overall voltage, storage capacity and thickness can be adjusted according to each customer’s power requirements. ©2010 Blue Spark Technologies.
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Transparent & Flexible Electronics - http://ozlab1.blogspot.com/2010_01_01_archive.html Power cells produced T-shirt fashion By James Sherwood July 2009
Power boffins have developed a prototype battery thatâ€™s not only lighter and thinner than existing power cells, but is produced using a printing process.
Printed Batteries Provide Paper-Thin Power August 2009
A team of German scientists has invented the world's first printable batteries. Thin, flexible and environmentally friendly, the batteries can be produced in large quantities for a fraction of what it takes to produce conventional batteries. The new battery is also different in other ways from conventional batteries. The printable version weighs less than one gram on the scales, is not even one millimeter thick and can therefore be integrated into bank cash cards, for example.The battery contains no mercury and is in this respect environmentally friendly. Its voltage is 1.5 V, which lies within the normal range.
- http://www.elektor.com/news/a-printed-battery.860844.lynkx A printed battery March 2009
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Transparent & Flexible Electronics The printed battery is an innovation developed by the department Printed Functionalities of the Fraunhofer ENAS in Germany. Series connections of printed batteries are possible for the first time, thus integer multiples of the nominal voltage of 1.5 V are realized (3 V, 4.5 V, 6 V). The battery system is zinc manganese which might be regarded as environmentally friendly. Parts of the batteries’ components may even be composed. By using high efficient printing technologies and the adaptation of the used materials, the production yield reaches almost 100 %. The printed batteries are especially suited for thin and flexible products. These might be e.g. intelligent chip and sensor cards, medical patches and plasters for transdermal medication and vital signs monitoring, as well as lab on chip analyses. The combination with other flexible or thin modules, at least, has to be accentuated. Hereby flexible displays and solar cells may be manufactured in the same manner of preparation and combined where required. More info Fraunhofer website
- http://gigaom.com/cleantech/mit-researchers-print-tiny-battery-using-viruses/ MIT Researchers Print Tiny Battery Using Viruses By Craig Rubens August 2008
Using nanorobots to build circuits is so last year’s fantasy. The latest technology of tomorrow uses viruses to construct everything from transistors to tiny batteries to solar cells. Researchers at MIT published a paper in the Proceedings of the National Academy of Sciences this week describing how they’ve successfully created tiny batteries, just four- to eight-millionths of a meter in diameter, using specially designed viruses. The hope is that these tiny batteries — which could be used in embedded medical sensors — and eventually other electronics, could be printed easily and cheaply onto surfaces and woven into fabrics.
Viruses are very orderly little critters and in high concentrations organize themselves into patterns, without high heat, toxic solvents or expensive equipment. By tweaking their DNA, the viruses, called M13, can be programmed to bind to inorganic materials, like metals and semiconductors. So far, the researchers have been able to use viruses to assemble the anode and electrolyte, two of the three main components of a battery. Eventually the work could also be used to make tiny electronics made up of silicon-covered viruses. Gross and cool. “It’s not really analogous to anything that’s done now,” lead researcher Angela Belcher told MIT Technology Review late last year when describing her work. “It’s about giving totally new kinds of functionalities to fibers.” The idea of thread-like electronics has gotten the interest of the Army, which has been funding Belcher’s research through the Army Research Office Institute of Collaborative Biotechnologies and the Army Research Office Institute of Soldier Nanotechnologies. Theoretically, these fibers could be woven into soldiers’ uniforms allowing clothing to sense biological or chemical agents as well as collect and store energy from the sun to power any number of devices. The team still has to create a cathode for the battery, but so far, so good; the researchers note that when a platinum cathode is attached, “the resulting electrode arrays exhibit full electrochemical functionality.” Belcher has also successfully created fibers that glow under UV light, tiny cobalt oxide wires and has even developed viruses that bind to gold. We’re still waiting to see some viral bling. Massimo Marrazzo - biodomotica.com 41
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- http://www.gizmag.com/go/7018/picture/32741/ Flexible see-through battery power By Mike Hanlon February 2007
Flexible see-through battery power All is no longer as it seems — the clear flexible plastic in the image is a battery — it is a polymer based rechargeable battery made by Japanese scientists. Drs Hiroyuki Nishide, Hiroaki Konishi and Takeo Suga at Waseda University have designed the battery — which consists of a redox-active organic polymer film around 200 nanometres thick. Nitroxide radical groups are attached, which act as charge carriers. Because of its high radical density, the battery has a high charge/discharge capacity. This is just one of many advantages the 'organic radical' battery has over other organic based materials according to the researchers. The power rate performance is strikingly high — it only takes one minute to fully charge the battery and it has a long cycle life, often exceeding 1,000 cycles. The team made the thin polymer film by a solution-processable method — a soluble polymer with the radical groups attached is _spin-coated" onto a surface. After UV irradiation, the polymer then becomes crosslinked with the help of a bisazide crosslinking agent. A drawback of some organic radical polymers is the fact they are soluble in the electrolyte solution which results in self-discharging of the battery — but the polymer must be soluble so it can be spin-coated. However, the photocrosslinking method used by the Japanese team overcomes the problem and makes the polymer mechanically tough. Dr Nishide said: This has been a challenging step, since most crosslinking reactions are sensitive to the nitroxide radical." Professor Peter Skabara, an expert in electroactive materials at the University of Strathclyde , praised the high stability and fabrication strategy of the polymer-based battery. The plastic battery plays a part in ensuring that organic device technologies can function in thin film and flexible form as a complete package." The news is reported in the edition of The Royal Society of Chemistry journal Chemical Communications.
- http://www.ee-yorkshire.com/yf/services/enquire.asp?id=10%20ES%2027F3%203ISQ&EnquiryType=BBS Transparent lithium ion secondary battery An Andalusian University has developed a novel transparent lithium ion secondary battery comprising a first transparent support, a first transparent electronic conductor and transparent positive and negative electrodes, a solid lithium ion electrolyte between the negative and positive electrodes, a second transparent conductor and a second transparent support. Its transparency to sunlight enables the integration of this battery into glass surfaces of buildings making it suitable for an energy saving and self-sustainable system, including lighting if combined with solar cells The invention also includes a method of manufacturing the battery.
Enterprise Europe Pdf document: transparent_lithium_ion_secondary_battery.pdf 42 Massimo Marrazzo - biodomotica.com
Transparent & Flexible Electronics
- http://www.oakridgemicro.com/tech/tfb.htm Thin-film rechargeable lithium batteries Thin-film rechargeable lithium batteries were developed by Dr. John Bates and his team of scientists and engineers from more than a decade of research at the Oak Ridge National Laboratory (ORNL). Unlike conventional batteries, thin film batteries can be deposited directly onto chips or chip packages in any shape or size, and when fabricated on thin plastics, the batteries are quite flexible.
Miniature thin film lithium battery on a ceramic substrate for use in an implantable medical device. Some of the unique properties of thin-film batteries that distinguish them from conventional batteries include: All solid state construction Can be operated at high and low temperatures (tests have been conducted between -20°C and 140°C) Can be made in any shape or size Cost does not increase with reduction in size (constant $/cm2) Completely safe under all operating conditions. Copyright © 2008 Oak Ridge Micro-Energy, Inc.
- http://www.excellatron.com/advantage.htm Thin Film Batteries A unique packaging technology has also been developed by Excellatron, enabling long-term shelf life of thin film batteries under harsh environmental conditions, such as high pressure, high temperature, and high humidity.
Rechargeable thin film solid state batteries manufactured by Excellatron. The total thickness of the battery is only 0.31mm ©Copyright 2008 Excellatron
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Transparent & Flexible Electronics - http://www.geomatec.co.jp/eng/product/products_06.html Thin-film rechargeable batteries Cooperation development with Iwate University
Film rechargeable battery An achievement in unparalleled thinness Thin-film rechargeable batteries are possible with a thickness of a few µm. The thin film is comprised of the support substrate, collectors, and electrodes, and nevertheless is thinner and more lightweight than even the thinnest current polymer batteries (several hundred µm thick). - http://news.rpi.edu/update.do?artcenterkey=2273&setappvar=page(1) Beyond Batteries: Storing Power in a Sheet of Paper Troy, N.Y. — Researchers at Rensselaer Polytechnic Institute have developed a new energy storage device that easily could be mistaken for a simple sheet of black paper. Copyright © 1996—2008 Rensselaer Polytechnic Institute
- http://www.frontedgetechnology.com/gen.htm NanoEnergy® is a miniature power source designed for highly space limited micro devices such as smart card, portable sensors, and RFID tag. ©2000-2008 Front Edge Technology, Inc.
Ultra thin Safe & environmentally friendly Long cycle life Flexible form factor Low self-discharge Bendable
As thin as 0.05 mm (0.002 inch) including package. All solid-state, using ceramic electrolyte LiPON developed by Oak Ridge National Laboratories. Contains no liquid or environmental hazardous material. More than 1, 000 cycles at 100% depth discharge. Can be made into different shapes and sizes. Less than 5% per year. Can be bent and twisted without damage.
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Charging batteries without wires - http://web.mit.edu/newsoffice/2007/wireless-0607.html MIT team experimentally demonstrates wireless power transfer, potentially useful for powering laptops, cell phones without cords. Franklin Hadley, Institute for Soldier Nanotechnologies Massachusetts Institute of Technology http://web.mit.edu/newsoffice/techtalk-info.html PDF
- http://12degreesoffreedom.blogspot.com/2008/03/wireless-electricity.html No strings (or wires) attached Researchers at the Massachusetts Institute of Technology think that transmitting power without wires is not only possible but within reach.
http://www.dailymail.co.uk/sciencetech/article-460602/The-end-plug-Scientists-invent-wireless-device-beams-electricity-home.html Scientists invent wireless device that beams electricity through your home
- http://news.cnet.com/Wireless-power-gets-recharged/2100-1041_3-6147684.html Wireless power gets recharged By Erica Ogg Staff Writer, CNET News.com
At the Consumer Electronics Show next week, two companies--Arizona-based start-up WildCharge and Michigan-based Fulton Innovation--will demonstrate what are expected to be very different ways to give gadgets juice, sans wires. The process creates an electromagnetic field, but does not interfere with Wi-Fi or Bluetooth devices and won't demagnetize credit cards, Baarman said. © 2008 CBS Interactive Inc
- https://www.wildcharge.com/index.cfm/fuseaction/category.display/category_ID/255/How_It_Works.htm The WildCharger pad is flat and thin with a conductive surface. Once a cell phone or other electronic device that is enabled with WildCharge technology is placed on the pad — anywhere on the pad and at any orientation — it will instantaneously receive power from the pad. It is that simple. And charging speed is the same as if the device is plugged to the wall! © 2008 WildCharge_
- http://ecoupled.com/technologyMain.html eCoupled technology_ is intelligent wireless power. It changes the way that people and devices interact with power and data. © 2008 Fulton Innovation , LLC
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WiTricity - http://en.wikipedia.org/wiki/WiTricity WiTricity, a portmanteau for wireless electricity, is a term coined initially by Dave Gerding in 2005 and used by an MIT research team led by Prof. Marin Soljaèiæ in 2007, to describe the ability to provide electrical energy to remote objects without wires. WiTricity is based on strong coupling between electromagnetic resonant objects to transfer energy wirelessly between them. The system consists of WiTricity transmitters and receivers that contain magnetic loop antennas critically tuned to the same frequency. As WiTricity operates in the electromagnetic near-field, the receiving devices must be no more than about a quarter wavelength from the transmitter (which is a few meters at the frequency used by the example system). In their first paper, the group also simulated GHz dielectric resonators.
1 Wall outlet 2 Resonant copper coil attached to frequency converter and plugged into outlet 3 Electromagnetic field 4 Resonant copper coil attached to light bulb
Wireless Light Marin Soljaèiæ and colleagues used magnetic resonance coupling to power a 60-watt light bulb. Tuned to the same frequency, two 60-centimeter copper coils can transmit electricity over a distance of two meters, through the air and around an obstacle.
- http://www.jcwa.or.jp/eng/knowledge/tech/tech05.html Non-contact recharging system watches Watches recharged by using a charger are called rechargeable watches. For wrist watches, the ordinary contact recharging method is not practical as it could lead to deterioration on a watch's quality characteristics such as water resistance. In this regard, however, a non-contact recharging system can be employed, so that the watch can be recharged without opening the case back when it is simply placed on a charger. When a watch is placed on a charger, an alternating magnetic field is created, which induces an alternating voltage in the internal coil of the watch. This induced voltage is rectified and stored in the energy storage unit to power the quartz watch. The mechanism of non-contact recharging system watches is explained below. 46 Massimo Marrazzo - biodomotica.com
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1. Place the watch on the charger. 2. An alternating current of approximately 20 Hz is applied to the primary coil inside the charger to produce an alternating magnetic field. 3. Across the secondary coil inside the watch, the induced voltage is generated based on Faraday's law of electromagnetic induction. 4. The alternating voltage induced across the secondary coil is rectified and stored in the secondary battery. 5. The secondary battery transmits the electrical energy to the driving circuit to run the quartz watch.
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Solar Energy - http://media.caltech.edu/press_releases/13325 Caltech Researchers Create Highly Absorbing, Flexible Solar Cells with Silicon Wire Arrays Pasadena, Calif.— Using arrays of long, thin silicon wires embedded in a polymer substrate, a team of scientists from the California Institute of Technology (Caltech) has created a new type of flexible solar cell that enhances the absorption of sunlight and efficiently converts its photons into electrons. The solar cell does all this using only a fraction of the expensive semiconductor materials required by conventional solar cells. "These solar cells have, for the first time, surpassed the conventional light-trapping limit for absorbing materials," says Harry Atwater, Howard Hughes Professor, professor of applied physics and materials science, and director of Caltech's Resnick Institute, which focuses on sustainability research.
This is a photomicrograph of a silicon wire array embedded within a transparent, flexible polymer film. [Credit: Caltech/Michael Kelzenberg]
The light-trapping limit of a material refers to how much sunlight it is able to absorb. The silicon-wire arrays absorb up to 96 percent of incident sunlight at a single wavelength and 85 percent of total collectible sunlight. "We've surpassed previous optical microstructures developed to trap light," he says. Atwater and his colleagues—including Nathan Lewis, the George L. Argyros Professor and professor of chemistry at Caltech, and graduate student Michael Kelzenberg—assessed the performance of these arrays in a paper appearing in the February 14 advance online edition of the journal Nature Materials. Atwater notes that the solar cells' enhanced absorption is "useful absorption." "Many materials can absorb light quite well but not generate electricity—like, for instance, black paint," he explains. "What's most important in a solar cell is whether that absorption leads to the creation of charge carriers." The silicon wire arrays created by Atwater and his colleagues are able to convert between 90 and 100 percent of the photons they absorb into electrons—in technical terms, the wires have a near-perfect internal quantum efficiency. "High absorption plus good conversion makes for a high-quality solar cell," says Atwater. "It's an important advance." The key to the success of these solar cells is their silicon wires, each of which, says Atwater, "is independently a high-efficiency, high-quality solar cell." When brought together in an array, however, they're even more effective, because they interact to increase the cell's ability to absorb light. "Light comes into each wire, and a portion is absorbed and another portion scatters. The collective scattering interactions between the wires make the array very absorbing," he says.
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This is a schematic diagram of the light-trapping elements used to optimize absorption within a polymerembedded silicon wire array. [Credit: Caltech/Michael Kelzenberg]
This effect occurs despite the sparseness of the wires in the arrayâ€”they cover only between 2 and 10 percent of the cell's surface area. "When we first considered silicon wire-array solar cells, we assumed that sunlight would be wasted on the space between wires," explains Kelzenberg. "So our initial plan was to grow the wires as close together as possible. But when we started quantifying their absorption, we realized that more light could be absorbed than predicted by the wire-packing fraction alone. By developing light-trapping techniques for relatively sparse wire arrays, not only did we achieve suitable absorption, we also demonstrated effective optical concentrationâ€”an exciting prospect for further enhancing the efficiency of silicon-wire-array solar cells." Each wire measures between 30 and 100 microns in length and only 1 micron in diameter. _The entire thickness of the array is the length of the wire," notes Atwater. _But in terms of area or volume, just 2 percent of it is silicon, and 98 percent is polymer." In other words, while these arrays have the thickness of a conventional crystalline solar cell, their volume is equivalent to that of a two-micron-thick film. Since the silicon material is an expensive component of a conventional solar cell, a cell that requires just onefiftieth of the amount of this semiconductor will be much cheaper to produce. The composite nature of these solar cells, Atwater adds, means that they are also flexible. "Having these be complete flexible sheets of material ends up being important," he says, "because flexible thin films can be manufactured in a roll-to-roll process, an inherently lower-cost process than one that involves brittle wafers, like those used to make conventional solar cells." Atwater, Lewis, and their colleagues had earlier demonstrated that it was possible to create these innovative solar cells. "They were visually striking," says Atwater. "But it wasn't until now that we could show that they are both highly efficient at carrier collection and highly absorbing." The next steps, Atwater says, are to increase the operating voltage and the overall size of the solar cell. "The structures we've made are square centimeters in size," he explains. "We're now scaling up to make cells that will be hundreds of square centimetersâ€”the size of a normal cell." Atwater says that the team is already "on its way" to showing that large-area cells work just as well as these smaller versions. In addition to Atwater, Lewis, and Kelzenberg, the all-Caltech coauthors on the Nature Materials paper, "Enhanced absorption and carrier collection in Si wire arrays for photovoltaic applications," are postdoctoral scholars Shannon Boettcher and Joshua Spurgeon; undergraduate student Jan Petykiewicz; and graduate students Daniel Turner-Evans, Morgan Putnam, Emily Warren, and Ryan Briggs. Their research was supported by BP and the Energy Frontier Research Center program of the Department of Energy, and made use of facilities supported by the Center for Science and Engineering of Materials, a National Science Foundation Materials Research Science and Engineering Center at Caltech. In addition, Boettcher received fellowship support from the Kavli Nanoscience Institute at Caltech. Lori Oliwenstein (626) 395-3631 email@example.com
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Transparent & Flexible Electronics - http://www.solarisnano.com/coretechnologies.php Solaris has proprietary and patented approaches for dramatically lowering the cost of solar panels and improving the efficiency of photovoltaics. Our proven and validated process for recharging of low manufacturing cost dye sensitized solar cells (DSSC) eliminates the existing lifetime limitations of these photovoltaics, allowing them to function beyond the lifetime of current silicon technology. When combined with government subsidies, these solar cells will cost the consumer less than $3,000 with a five year payback period. This is in comparison to current silicon technology which requires cash outlays of $12,000 or more with payback periods in excess of twelve years in most US residential markets. Furthermore, the Solaris’ non-toxic materials based process for recharging DSSCs allows for future improvements in the installed base of solar cells through recharging with newly developed, higher-efficiency dyes. This technology represents the world’s first and only rechargeable photovoltaic with the capability for post-installation upgrades. Based on conservative market growth and penetration, we believe that this product can exceed a billion dollars of annual revenue for Solaris within the next decade.
Various colors in a series-connected dye solar cell modules, courtesy of Dr. Winfried Hofmann, RWE-Schott Dye-sensitized electrochemical photovoltaic cells, also known as Graetzel Cells, offer significantly lower manufacturing costs because of their simplicity and use of low-cost active materials such as TiO2. Solaris Nanosciences has demonstrated a completely rechargeable dye sensitized solar cell (DSSC or Graetzel Cell) creating the lowest manufacturing cost, long-life photovoltaic system in the world. DSSCs which are based on low cost materials and simple construction, have to date suffered from limited operating lifetimes due to the degradation of the sensitizer dyes. Solaris' nontoxic chemical process allows the degraded dye in already installed DSSCs to be removed and replaced with new dye, restoring the performance of the original solar cell.
DSSC or Graetzel Cell - http://en.wikipedia.org/wiki/Dye-sensitized_solar_cell A dye-sensitized solar cell (DSSC, DSC or DYSC) is a class of low-cost solar cell belonging to the group of thin film solar cells. It is based on a semiconductor formed between a photo-sensitized anode and an electrolyte; a photoelectrochemical system. This cell was invented by Michael Grätzel and Brian O'Regan at the École Polytechnique Fédérale de Lausanne in 1991 and are also known as Grätzel cells. Michael Grätzel won the 2010 Millennium Technology Prize for the invention of the Grätzel cell. Grätzel's cell is composed of a porous layer of titanium dioxide nanoparticles, covered with a molecular dye that absorbs sunlight, like the chlorophyll in green leaves. The titanium dioxide is immersed under an 50 Massimo Marrazzo - biodomotica.com
Transparent & Flexible Electronics electrolyte solution, above which is a platinum-based catalyst. As in a conventional alkaline battery, an anode (the titanium dioxide) and a cathode (the platinum) are placed on either side of a liquid conductor (the electrolyte). Sunlight passes through the transparent electrode into the dye layer where it can excite electrons that then flow into the titanium dioxide. The electrons flow toward the transparent electrode where they are collected for powering a load. After flowing through the external circuit, they are re-introduced into the cell on a metal electrode on the back, flowing into the electrolyte. The electrolyte then transports the electrons back to the dye molecules. Dye-sensitized solar cells separate the two functions provided by silicon in a traditional cell design. Normally the silicon acts as both the source of photoelectrons, as well as providing the electric field to separate the charges and create a current. In the dye-sensitized solar cell, the bulk of the semiconductor is used solely for charge transport, the photoelectrons are provided from a separate photosensitive dye. Charge separation occurs at the surfaces between the dye, semiconductor and electrolyte. The dye molecules are quite small (nanometer sized), so in order to capture a reasonable amount of the incoming light the layer of dye molecules needs to be made fairly thick, much thicker than the molecules themselves. To address this problem, a nanomaterial is used as a scaffold to hold large numbers of the dye molecules in a 3-D matrix, increasing the number of molecules for any given surface area of cell. In existing designs, this scaffolding is provided by the semiconductor material, which serves double-duty.
- https://inlportal.inl.gov/portal/server.pt?open=514&objID=1269&mode=2&featurestory=DA_101047 Harvesting the sun's energy with antennas
INL researcher Steven Novack holds a plastic sheet of nanoantenna arrays, created by embossing the antenna structure and depositing a conductive metal in the pattern. Each square contains roughly 260 million antennas. Nanotechnology R&D usually occurs on the centimeter scale, but this INL-patented manufacturing process demonstrates nano-scale features can be produced on a larger scale. (Credit: U.S. Department of Energy's Idaho National Laboratory)
Researchers at Idaho National Laboratory, along with partners at Microcontinuum Inc. (Cambridge, MA) and Patrick Pinhero of the University of Missouri, are developing a novel way to collect energy from the sun with a technology that could potentially cost pennies a yard, be imprinted on flexible materials and still draw energy after the sun has set.
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Transparent & Flexible Electronics The new approach, which garnered two 2007 Nano50 awards, uses a special manufacturing process to stamp tiny loops of conducting metal onto a sheet of plastic. Each "nanoantenna" is as wide as 1/25 the diameter of a human hair. Because of their size, the nanoantennas absorb energy in the infrared part of the spectrum, just outside the range of what is visible to the eye. The sun radiates a lot of infrared energy, some of which is soaked up by the earth and later released as radiation for hours after sunset. Nanoantennas can take in energy from both sunlight and the earth's heat, with higher efficiency than conventional solar cells.
An array of loop nanoantennas, imprinted on plastic and imaged with a scanning electron microscope. The deposited wire is roughly 200 nanometers thick. (Credit: U.S. Department of Energy's Idaho National Laboratory)
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Transparent & Flexible Electronics Commercial solar panels usually transform less that 20 percent of the usable energy that strikes them into electricity. The team estimates individual nanoantennas can absorb close to 80 percent of the available energy. The circuits themselves can be made of a number of different conducting metals, and the nanoantennas can be printed on thin, flexible materials like polyethylene, a plastic that's commonly used in bags and plastic wrap. In fact, the team first printed antennas on plastic bags used to deliver the Wall Street Journal, because they had just the right thickness
- http://www.guardian.co.uk/environment/2007/dec/29/solarpower.renewableenergy Solar energy 'revolution' brings green power closer. Power from light: Photovoltaic (PV) devices convert light into electrical energy. PV cells are made of semiconductor materials such as silicon. When light shines on a PV cell, the energy is transferred to electrons in the atoms of the PV cell. These electrons become part of the electrical flow, or current, in an electrical circuit. First wave photovoltaic cell used thick silicon-wafer cells but were cumbersome and costly. The second generation of photovoltaic materials were developed about 10 years ago and use very thin silicon layers. These brought the price down dramatically but still need expensive vacuum processes in their construction. The third wave of PV, now being developed by firms such as Nanosolar, can print directly on to other materials and does not use silicon.
- http://www.sciencedaily.com/releases/2008/04/080410101210.htm Future Of Solar-powered Houses Is Clear: New Windows Could Halve Carbon Emissions Professor John Bell said QUT had worked with a Canberra-based company Dyesol, which is developing transparent solar cells that act as both windows and energy generators in houses or commercial buildings. "The transparent solar cells have a faint reddish hue but are completely see-through," Professor Bell said. "The solar cells contain titanium dioxide coated in a dye that increases light absorption. "The glass captures solar energy which can be used to power the house but can also reduce overheating of the house, reducing the need for cooling." Copyright © 1995-2008 ScienceDaily LLC
- http://www.hp.com/hpinfo/newsroom/press/2008/080604a.html HP Licenses Technology to Xtreme Energetics for Creation of Super-efficient Solar Energy System HP and Xtreme Energetics (XE), a solar energy system developer based in Livermore, Calif., today announced they have entered into an agreement for the development of a solar energy system designed to generate electricity at twice the efficiency and half the cost of traditional solar panels. Under the technology collaboration and licensing agreement, HP will license its transparent transistor technology to XE in return for royalty payments. The transparent transistor technology that will be used in XE's solar energy device was co-developed by HP and Oregon State University. The technology includes thin film transparent transistors, which are made from low-cost, readily available materials such as zinc and tin. The materials raise no environmental concerns and allow for higher mobility, better chemical stability and easier manufacture. © 2008 Hewlett-Packard Development Company, L.P
- http://www.xyhd.tv/2007/09/technical/nanosolar-the-solar-cell-you-print-on-your-computer/ Nano Solar uses an inkjet to create solar cells that are extremely thin, and cheap to manufacture. The Technology is interesting. Because it is printed the cells are amazingly thin, transparent even. So it can be applied to windows, or other surfaces. Using copper indium gallium diselenide (CIGS) an inorganic photovoltaic compound literally used as an ink a film, or sheet can be printed to what ever size and shape is needed and then nanocomponents in the ink align themselves properly via molecular self-assembly. XYHD.TV © 2007
- http://www.nanosolar.com/products.htm Nanosolar SolarPly_. Light-weight solar-electric cell foil which can be cut to any size. Non-fragile. No soldering required for electrical contact. Copyright © 2002 - 2008, Nanosolar, Inc.
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- http://www.octillioncorp.com/nano-power.php NanoPower Windows (nanosilicon photovoltaic solar cells) The technological potential of adapting existing glass windows into ones capable of generating electricity from the sun's solar energy has been made possible through a ground breaking discovery of an electrochemical and ultrasound process that produces identically sized (1 to 4 nanometers in diameter) nanoparticles of silicon that provide varying wavelengths of photoluminescence and high quantum efficiency (50% to 60%). Octillion Corp. © 2008
- http://www.nextenergynews.com/news1/next-energy-news1.7d.html Scientists Invent Solar Cell Sheet That Collects Energy at Night Researchers at Idaho National Laboratory, along with partners at Microcontinuum Inc. (Cambridge, MA) and Patrick Pinhero of the University of Missouri, are developing a novel way to collect energy from the sun with a technology that could potentially cost pennies a yard, be imprinted on flexible materials and still draw energy after the sun has set. Copyright © 2008, Next Energy News.
- http://www.sciencedaily.com/releases/2008/07/080731143345.htm 'Major Discovery' Primed To Unleash Solar Revolution: Scientists Mimic Essence Of Plants' Energy Storage System In a revolutionary leap that could transform solar power from a marginal, boutique alternative into a mainstream energy source, MIT researchers have overcome a major barrier to large-scale solar power: storing energy for use when the sun doesn't shine. Copyright © 1995-2008 ScienceDaily LLC
- http://www.openecosource.org/energy-systems/promising-and-innovative-konarka-photovoltaics Konarka builds Power Plastic® that converts light to energy — anywhere. The company develops and manufactures light-activated Power Plastic® that is inexpensive, lightweight, flexible and versatile. This material makes it possible for devices, systems and structures to have their own low cost embedded sources of renewable power. By integrating energy generation functionality into everyday devices, Konarka allows manufacturers to offer truly wireless applications. - http://www.konarka.com/index.php/site/tech_power_plastic/ Konarka builds products that convert light to energy anywhere. Download PDF file - http://science.howstuffworks.com/solar-cell.htm In this article, they will examine solar cells to learn how they convert the sun's energy directly into electricity. - http://www.rug.nl/edrec/nieuws/nieuwsberichten/ontwikkelingDoorzichtigeZonnecellen?lang=en Researcher from Groningen developes transparent solar cells
- http://greenmonk.net/hp-teaming-with-xtreme-energetics-to-produce-cheaper-more-efficient-cheaper-solar/ HP teaming with Xtreme Energetics to produce cheaper, more efficient cheaper solar - http://venturebeat.com/2008/06/16/xtreme-energetics-ultra-efficient-pretty-solar-systems-catch-hps-eye/ Xtreme Energetics' ultra-efficient, pretty solar systems catch HP's eye.
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Seebeck effect - Thermoelectric Electricity from the body heat http://www.eetimes.com/design/smart-energy-design/4011571/Energy-harvesting-chips-and-the-quest-for-everlasting-life
Energy-harvesting chips and the quest for everlasting life Erick O. Torres, Student Member, IEEE, and Gabriel A. Rincón-Mora, Senior Member, IEEE Georgia Tech Analog and Power IC Design Lab
Modern electronics continue to push past boundaries of integration and functional density, towards the elusive completely autonomous self-powered microchip. As systems continue to shrink, however, less energy is available on-board, leading to short device lifetime (runtime or battery life). Research continues to develop higher energy-density batteries but the amount of energy available is not only finite but also low, limiting the system's lifespan, which is paramount in portable electronics. Extended life is also particularly advantageous in systems with limited accessibility, such as biomedical implants and structure-embedded micro-sensors. The ultimate long-lasting solution should therefore be independent of the limited energy available during start-up, which is where a self-renewing energy source comes in, continually replenishing the energy consumed by the micro-system. State-of-the-art micro-electromechanical system (MEMS) generators and transducers can be such selfrenewing sources, extracting energy from vibrations, thermal gradients, and light. The energy extracted from these sources is stored in chip-compatible, rechargeable batteries such as thin-film lithium ion, which powers the loading application (e.g., sensor, etc.) via a regulator circuit. Since harvested energy manifests itself in irregular, random, low energy "bursts," a power-efficient, discontinuous, intermittent charger is required to transfer the energy from the sourcing devices to the battery. Energy that is typically lost or dissipated in the environment is therefore recovered and used to power the system, significantly extending the operational lifetime of the device. Harvesting Energy Energy harvesting is defined as the conversion of ambient energy into usable electrical energy. When compared with the energy stored in common storage elements, like batteries and the like, the environment represents a relatively inexhaustible source of energy. Consequently, energy harvesting (i.e., scavenging) methods must be characterized by their power density, rather than energy density. Table 1 compares the estimated power and challenges of various ambient energy sources. Light, for instance, can be a significant source of energy, but it is highly dependant on the application and the exposure to which the device is subjected. Thermal energy, on the other hand, is limited because the temperature differentials across a chip are typically low. Vibration energy is a moderate source, but again dependent on the particular application. Energy Source Light
Challenge Conform to small surface area
Variability of vibration
Small thermal gradients
Estimated Power (in 1 cm3 or 1 cm2) 10 µW - 15 mW (Outdoors: 0.15 - 15 mW) (Indoors: <10 µW) 1 - 200 µW (Piezoelectric: ~ 200 µW) (Electrostatic: 50 - 100 µW) (Electromagnetic: < 1µW) 15 µW (10°C gradient)
Comparison between different ambient energy sources
Vibration Energy Energy extraction from vibrations is based on the movement of a "spring-mounted" mass relative to its support frame. Mechanical acceleration is produced by vibrations that in turn cause the mass component to move and oscillate (kinetic energy). This relative displacement causes opposing frictional and damping forces to be exerted against the mass, thereby reducing and eventually extinguishing the oscillations. The damping forces literally absorb the kinetic energy of the initial vibration. This energy can be converted into electrical energy via an electric field (electrostatic), magnetic field (electromagnetic), or strain on a piezoelectric material. These energy-conversion schemes amount to harvesting energy from vibrations.
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Electromagnetic vibration energy harvester Electromagnetic energy harvesting uses a magnetic field to convert mechanical energy to electrical. A coil attached to the oscillating mass traverses through a magnetic field that is established by a stationary magnet. The coil travels through a varying amount of magnetic flux, inducing a voltage according to Faraday's law. The induced voltage is inherently small and must therefore be increased to viably source energy. Methods to increase the induced voltage include using a transformer, increasing the number of turns of the coil, and/or increasing the permanent magnetic field. However, each is limited by the size constraints of a microchip. Piezoelectric energy harvesting converts mechanical energy to electrical by straining a piezoelectric material. Strain, or deformation, in a piezoelectric material causes charge separation across the device, producing an electric field and consequently a voltage drop proportional to the stress applied. The oscillating system is typically a cantilever beam structure with a mass at the unattached end of the lever, since it provides higher strain for a given input force (a). The voltage produced varies with time and strain, effectively producing an irregular ac signal. Piezoelectric energy conversion produces relatively higher voltage and power density levels than the electromagnetic system.
(a) Piezoelectric energy harvesting beam and (b) MEMS varactors (c) in an energy-harvesting circuit Electrostatic (capacitive) energy harvesting relies on the changing capacitance of vibration-dependant varactors [3, 8-9]. A varactor, or variable capacitor, is initially charged and, as its plates separate because of vibrations, mechanical energy is transformed into electrical energy (Figures 3b and 3c). The most attractive feature of this method is its IC-compatible nature, given that MEMS variable capacitors are fabricated through relatively mature silicon micro-machining techniques. This scheme produces higher and more practical output voltage levels than the electromagnetic method, with moderate power density.
Thermal Energy Thermal gradients in the environment are directly converted to electrical energy through the Seebeck (thermoelectric) effect. Temperature differentials between opposite segments of a conducting material result in heat flow and consequently charge flow, since mobile, high-energy carriers diffuse from high to low concentration regions. Thermopiles consisting of n- and p-type materials electrically joined at the hightemperature junction are therefore constructed, allowing heat flow to carry the dominant charge carriers of each material to the low temperature end, establishing in the process a voltage difference across the base electrodes. The generated voltage and power is proportional to the temperature differential and the Seebeck coefficient of the thermoelectric materials. Large thermal gradients are essential to produce practical voltage and power levels. Nevertheless, temperature differences greater than 10째C are rare in a micro-system, consequently producing low voltage and power levels. 56 Massimo Marrazzo - biodomotica.com
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Thermoelectrics - http://en.wikipedia.org/wiki/Energy_harvesting Energy harvesting (also known as power harvesting or energy scavenging) is the process by which energy is derived from external sources (e.g., solar power, thermal energy, wind energy, salinity gradients, and kinetic energy), captured, and stored. Frequently, this term is applied when speaking about small, wireless autonomous devices, like those used in wearable electronics and wireless sensor networks.
Thermoelectrics In 1821, Thomas Johann Seebeck discovered that a thermal gradient formed between two dissimilar conductors produces a voltage. At the heart of the thermoelectric effect is the fact that a temperature gradient in a conducting material results in heat flow; this results in the diffusion of charge carriers. The flow of charge carriers between the hot and cold regions in turn creates a voltage difference. In 1834, Jean Charles Athanase Peltier discovered that running an electric current through the junction of two dissimilar conductors could, depending on the direction of the current, cause it to act as a heater or cooler. The heat absorbed or produced is proportional to the current, and the proportionality constant is known as the Peltier coefficient. Today, due to knowledge of the Seebeck and Peltier effects, thermoelectric materials can be used as heaters, coolers and generators (TEGs). Ideal thermoelectric materials have a high Seebeck coefficient, high electrical conductivity, and low thermal conductivity. Low thermal conductivity is necessary to maintain a high thermal gradient at the junction. Standard thermoelectric modules manufactured today consist of P- and N-doped bismuth-telluride semiconductors sandwiched between two metallized ceramic plates. The ceramic plates add rigidity and electrical insulation to the system. The semiconductors are connected electrically in series and thermally in parallel. Miniature thermocouples have been developed that convert body heat into electricity and generate 40ÂľW at 3V with a 5 degree temperature gradient, while on the other end of the scale, large thermocouples are used in nuclear RTG batteries. Practical examples are the finger-heartratemeter by the Holst Centre and the thermogenerators by the Fraunhofer Gesellschaft. Advantages to thermoelectrics: No moving parts allow continuous operation for many years. Tellurex Corporation (a thermoelectric production company) claims that thermoelectrics are capable of over 100,000 hours of steady state operation. Thermoelectrics contain no materials that must be replenished. Heating and cooling can be reversed. One downside to thermoelectric energy conversion is low efficiency (currently less than 10%). The development of materials that are able to operate in higher temperature gradients, and that can conduct electricity well without also conducting heat (something that was until recently thought impossible), will result in increased efficiency. Future work in thermoelectrics could be to convert wasted heat, such as in automobile engine combustion, into electricity.
Thermoelectric effect The thermoelectric effect is the direct conversion of temperature differences to electric voltage and vice versa. A thermoelectric device creates a voltage when there is a different temperature on each side. Conversely when a voltage is applied to it, it creates a temperature difference (known as the Peltier effect). At atomic scale (specifically, charge carriers), an applied temperature gradient causes charged carriers in the material, whether they are electrons or electron holes, to diffuse from the hot side to the cold side, similar to a classical gas that expands when heated; hence, the thermally induced current. This effect can be used to generate electricity, to measure temperature, to cool objects, or to heat them or cook them. Because the direction of heating and cooling is determined by the polarity of the applied voltage, thermoelectric devices make very convenient temperature controllers. Traditionally, the term thermoelectric effect or thermoelectricity encompasses three separately identified effects, the Seebeck effect, the Peltier effect, and the Thomson effect. In many textbooks, thermoelectric effect may also be called the Peltierâ€“Seebeck effect. This separation derives from the independent discoveries of French physicist Jean Charles Athanase Peltier and Estonian-German physicist Thomas Johann Seebeck. Joule heating, the heat that is generated whenever a voltage is applied across a resistive material, is somewhat related, though it is not generally termed a thermoelectric effect (and it is usually regarded as being a loss mechanism due to non-ideality in thermoelectric devices). The Peltierâ€“Seebeck and Thomson effects can in principle be thermodynamically reversible, whereas Joule heating is not. Massimo Marrazzo - biodomotica.com 57
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Seebeck discovered that a compass needle would be deflected when a closed loop was formed of two metals joined in two places with a temperature difference between the junctions. This is because the metals respond differently to the temperature difference, which creates a current loop, which produces a magnetic field. Seebeck, however, at this time did not recognize there was an electric current involved, so he called the phenomenon the thermomagnetic effect, thinking that the two metals became magnetically polarized by the temperature gradient. The Danish physicist Hans Christian Ørsted played a vital role in explaining and conceiving the term "thermoelectricity". The effect is that a voltage, the thermoelectric EMF, is created in the presence of a temperature difference between two different metals or semiconductors. This causes a continuous current in the conductors if they form a complete loop. The voltage created is of the order of several microvolts per kelvin difference. One such combination, copper-constantan, has a Seebeck coefficient of 41 microvolts per kelvin at room temperature.
The Seebeck Effect The generator module is a unique semiconductor device that relies upon the Seebeck effect to generate electricity. When two dissimilar semiconductors (p-type and n-type) at the same temperature are connected together they establish a static electric potential difference. With the introduction of a temperature difference heat flows across the joined semiconductors which in turn permits electrons to flow. With the electron flow or current comes the ability to power electrical devices such as the fan's motor.
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Seebeck-Thermoelectric - http://www.artechhouse.com/GetBlob.aspx?strName=Beeby-718_CH05.pdf Thermoelectric Energy Harvesting Gao Min - Cardiff University, United Kingdom
Thermoelectric module. (a) Schematic diagram of a thermoelectric module. (b) Crosssectional view of a thermoelectric module which consists of a number of n- and p-type thermocouples connected electrically in series but thermally in parallel and sandwiched between two ceramic plates. Low Power Systems
Advance in modern microelectronics has led to a significant reduction in the power level requirement. Modern-day remote wireless sensors can operate at a power level of about 130 µW. A quartz digital wristwatch requires merely 20 to 40 µW. At such a power level, it is possible to use thermoelectric devices to harvest ambient heat for powering remote sensor networks or mobile devices. This eliminates the needs for replacing batteries or for lengthy cabling from central power sources. A particularly attractive feature of thermoelectric devices is their ability to generate electricity from body heat that could power medical implants, personal wireless devices, or other consumer electronics. A successful example in this attempt is the thermoelectric wristwatch developed by Seiko and Citizen. Figure below shows a schematic cross-section of a thermoelectric watch. A miniature thermoelectric converter that consists of 2,268 pairs of Bi2Te3 thermocouples is mounted on the bottom case of the watch. It produces on average 25 µW of electricity from a temperature difference of 2–3K generated by body heat. The conversion efficiency is about 0.1% (compared with the corresponding Carnot efficiency of 0.66%). Although it is technologically successful, its commercialization has been restricted mainly due to the cost of the thermoelectric converter employed. In a normal environment, the temperature difference between human body and ambient is around 5–10K. The rate of heat generation for an average human body is typically around 100W. Using such data, the power output that can be harvested using a thermoelectric device is estimated to be 20–50 µW/cm2. This indicates that the power of about 2–5 mW may be obtained with a realistic surface area of 0.1 m2 (equivalent to an area of 40 cm × 25 cm) that enables heat extraction from a body without causing significant inconvenience or discomfort. Such a power level is sufficient for some low-power applications.
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A schematic diagram of thermoelectric wristwatch. A miniature thermoelectric converter is placed on the bottom case of the watch.
- http://www.jcwa.or.jp/eng/knowledge/tech/tech04.html Thermal generating system watches
- http://www.media.mit.edu/resenv/pubs/books/Starner-Paradiso-CRC.1.452.pdf Human Generated Power for Mobile Electronics Thad Starner Joseph A. Paradiso GVU Center, College of Computing Responsive Environments Group, Media Laboratory Georgia Tech MIT Atlanta, GA 30332-0280 Cambridge, MA 02139
Power from Body Heat Activity Kilocal/hr sleeping 70 lying quietly 80 sitting 100 standing at ease 110 conversation 110 eating meal 110 strolling 140 driving car 140 playing violin or piano 140 housekeeping 150 carpentry 230 hiking, 4 mph 350 swimming 500 mountain climbing 600 long distance run 900 sprinting 1,400 Human energy expenditures for selected activities.
Watts 81 93 116 128 128 128 163 163 163 175 268 407 582 698 1,048 1,630
Derived from: D. Morton. Human Locomotion and Body Form. The Williams & Wilkins Co., Baltimore, MD, 1952.
Table indicates that while sitting, a total of 116W of power is available. Using a Carnot engine to model the recoverable energy yields 3.7-6.4Wof power. In more extreme temperature differences, higher efficiencies may be achieved, but robbing the user of heat in adverse environmental temperatures is not practical. Evaporative heat loss from humans account for 25% of their total heat dissipation (basal, non-sweating) even under the best of conditions. This â€œinsensible perspirationâ€? consists of water diffusing through the skin, sweat glands keeping the skin of the palms and soles pliable, and the expulsion of water-saturated air from the 60 Massimo Marrazzo - biodomotica.com
Transparent & Flexible Electronics lungs. Thus, the maximum power available without trying to reclaim heat expended by the latent heat of vaporization drops to 2.8-4.8W. The above efficiencies assume that all of the heat radiated by the body is captured and perfectly transformed into power. However, such a system would encapsulate the user in something similar to a wetsuit. The reduced temperature at the location of the heat exchanger would cause the body to restrict blood flow to that area. When the skin surface encounters cold air, a rapid constriction of the blood vessels in the skin allows the skin temperature to approach the temperature of the interface so that heat exchange is reduced. This selfregulation causes the location of the heat pump to become the coolest part of the body, further diminishing the returns of the Carnot engine unless a wetsuit is employed as part of the design. While a full wetsuit or even a torso body suit is unsuitable for many applications, the neck offers a good location for a tight seal, access to major centers of blood flow, and easy removal by the user. The neck is approximately 1/15 of the surface area of the “core” region (those parts that the body tries to keep warm at all times). As a rough estimate, assuming even heat dissipation over the body, a maximum of 0.20-0.32W could be recovered conveniently by such a neck brace. The head may also be a convenient heat source for some applications where protective hoods are already in place - the head is also a very convenient spot for coupling sensory input to the user. The surface area of the head is approximately three times that of the neck and could provide 0.60-0.96W of power given optimal conversion. Even so, the practicality, comfort, and efficacy of such a system are relatively limited. Even given all the limitations mentioned above, practical body-worn, thermally-powered systems have been created. The Seiko Thermic wristwatch uses 10 thermoelectric modules to generate sufficient simbolo mu microW to run its mechanical clock movement from the small thermal gradient provided by body heat over ambient temperature.
Possible power recovery from body-centered sources. Total power for each action is included in parentheses.
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Fraunhofer Institute - http://www.fraunhofer.de/EN/press/pi/2007/08/Researchnews82007Topic1.jsp Electricity from body heat In collaboration with colleagues from the Fraunhofer Institute for Physical Measurement Techniques IPM and the Fraunhofer Institute for Manufacturing Engineering and Applied Materials Research IFAM, research scientists at the Fraunhofer Institute for Integrated Circuits IIS in Erlangen have developed a way of harnessing natural body heat to generate electricity. It works on the principle of thermoelectric generators, TEG for short, made from semiconductor elements. © 4/2008 Fraunhofer-Gesellschaft
- http://bme240.eng.uci.edu/students/08s/rogers/Heat.html Thermoelectrics Introduction: Scientists of the Fraunhofer Society, as well as the company Biophan, are exploring devices and semiconductor materials for the generation of electricity from small temperature gradients in the body. Up to 5°C of difference can be found across certain parts of the body, such as between the skin and the environment. As far back as 1998, the feasibility of scavenging power from this source was proven for nonbiomedical applications by Japanese watch company Seiko, which introduced a "Thermic" wristwatch that ran on heat from the skin.
Device Design: In the medical field, Biophan hopes to extend the operating life of small implants by continuously recharging them with a bismuth telluride semiconductor-based thermoelectric energy-scavenger. Pacemakers, for example, might have their lives extended from one decade to three by this method once the device is perfected, and lower-power devices might even run indefinitely. The company's goal is to produce a device that will be able to generate 100 µW at 4 V in a slim package about 1 inch squared, comparable in size to current Li-ion pacemaker batteries.
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Fujitsu - http://www.fujitsu.com/global/news/pr/archives/month/2010/20101209-01.html Fujitsu Develops Hybrid Energy Harvesting Device for Generating Electricity from Heat and Light Kawasaki, Japan, December 9, 2010 — Fujitsu Laboratories Ltd. today announced that it has developed a new hybrid energy harvesting device that generates electricity from either heat or light. With this single device, it is possible to derive energy from two separate sources, which previously could only be handled by combining individual devices. Furthermore, because the cost of the hybrid device is economical, this technology paves the way to the widespread use of highly efficient energy harvesting devices. The new technology has great potential in the area of energy harvesting, which converts energy from the surrounding environment to electricity. Since there is no need for electrical wiring or battery replacements, this development could enable the use of sensors in previously unserved applications and regions. It also has great potential for powering a variety of sensor networks and medical-sensing technologies. About Energy Harvesting Energy harvesting is the process for collecting energy from the surrounding environment and converting it to electricity, and is gaining interest as a future next-generation energy source. Conventionally, electricity is supplied by either a power plant or a battery, requiring electrical wiring and replacement batteries. In recent years, the idea of using ambient energy in the forms of light, vibration, heat, radio waves, etc. has become increasingly attractive, and a number of methods to produce electricity from these different kinds of energy sources have been developed. Energy harvesting technology would eliminate the need for replacing batteries and power cords.
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Overview of energy harvesting
Technological Challenges Since the amount of power available by energy harvesting is quite limited, there has been interest in utilizing multiple forms of external energy simultaneously - such as light and heat, or light and vibrations - in order to collect a sufficient amount for practical use. In the past, this has been achieved by combining different kinds of devices, which leads to higher costs. Newly-developed Technology Fujitsu Laboratories has developed a new hybrid harvesting device that captures energy from either light or heat, which are the most typical forms of ambient energy available for wide-scope application. This makes it possible for a single device to capture energy from either heat or light without combining two harvesting devices. In addition, as it can be manufactured from inexpensive organic materials, device production costs can remain low Details of the new technology are as follows. 1. New structure for hybrid generating devices By changing the electrical circuits connecting two types of semiconductor materials - P-type and N-type semiconductors - the device can function as a photovoltaic cell or thermoelectric generator (Figure below). 2. Development of an organic material for hybrid generating devices Fujitsu Laboratories successfully developed an organic material that is suitable for a generator in both photovoltaic and thermoelectric modes. The organic material features a high generating efficiency that can produce power from even indoor lighting in photovoltaic mode, and it can also generate power from heat in thermoelectric mode. Since the organic material and its process cost are inexpensive, production costs can be greatly reduced.
Single device featuring operation in both photovoltaic mode (left) and thermoelectric mode (right)
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Transparent & Flexible Electronics Results Until now, photovoltaic cells - which generate electricity from light, and thermoelectric devices - which generate electricity from temperature differentials, have only been available as separate devices. This new technology from Fujitsu Laboratories doubles the energy-capture potential through the use of both ambient heat and light in a single device. In medical fields, for example, the technology could be used in sensors that monitor conditions such as body temperature, blood pressure, and heartbeats - without batteries and electrical wiring. If either the ambient light or heat is not sufficient to power the sensor, this technology can supply power with both sources, by augmenting one source with the other. In addition, the technology can also be used for environmental sensing in remote areas for weather forecasting, where it would be problematic to replace batteries or run electric lines.
Prototype hybrid generating device manufactured on flexible substrate
□□□□□ - http://www.forbes.com/2010/06/07/nanotech-body-heat-technology-breakthroughs-devices.html
Turning Body Heat Into Electricity Osman Can Ozcanli, August 2010
Developments in nano-engineering could unleash new body-powered devices. The idea of converting the human body's energy into electricity has tantalized scientists for years. A resting male can put out between 100 and 120 watts of energy, in theory enough to power many of the electronics you use, such as your Nintendo Wii (14 watts), your cellphone (about 1 watt) and your laptop (45 watts). Eighty percent of body power is given off as excess heat. But only in sci-fi fantasies such as the Matrix film series do you see complete capture of this reliable power source. Current technology for converting body heat into electricity is capable of producing only a few milliwatts (one thousandth of a Watt), which is enough for small things such as heart rate monitors and watches. Some people fondly remember Seiko's Thermic watch, which runs continuously off body heat on 1 microwatt (onemillionth of a watt). It debuted in 1998 to rave reviews, but Seiko produced only 500 units before discontinuing it. If you own a Seiko Thermic, you never have to worry about changing batteries as long as your environment is cooler than your body. Recent developments in nanotechnology engineering promise to usher in lots more body-powered devices. The basic technology behind the concept of turning body heat into electricity is a thermoelectric device. It is usually a thin conductive material that exploits the temperature difference between its two sides to generate electricity, known as the Seebeck effect. Such devices can work in reverse, meaning if you were to apply electricity to the device, one side would get extremely cold and the other extremely hot. If you own a USBpowered drink chiller, you probably own a thermoelectric generator--only working in reverse. The same idea is also used in cooling some computers. Massimo Marrazzo - biodomotica.com 65
Transparent & Flexible Electronics A thermoelectric device placed on skin will generate power as long as the ambient air is at a lower temperature than the body. A patch of material one square centimeter in area can produce up to 30 microwatts. Place these generators side by side to multiply the amount of power being harvested. In 2006 Vladimir Leonov and Ruud J.M. Vullers from Belgium built a working prototype of a blood oxygen sensor, or pulse oxymeter, powered with body heat. It was about the size of a watch and was successfully tested on patients. It generated about 100 microwatts while the patient was asleep and up to 600 microwatts when awake and active. The group had to design the device so it could work with a record low power of 62 microwatts vs. commercially available 10-milliwatt pulse oxymeters. In 2007 the duo built a body-heat powered electroencephalograph device that monitored brain activity. Leonov and Vullers started by redesigning the EEG device so it consumed less power. The EEG had to wirelessly transmit real-time data to a computer, too, so it had to consume a lot more power than their first prototype. The 50-square-centimeter prototype was placed on the forehead of a person and harvested 3,500 microwatts, which was great, but came with a side effect: With so much area covered with thermoelectric devices sucking the heat, the sensation of cold became overwhelming to the patient.
The following year, the duo added photovoltaic cells to the top of the device to harvest solar power to offset some of the thermoelectric generation and make the device less chilly for the patient.
Next, they built a body-heat powered electrocardiograph device (EKG) that monitored heart activity. This time, they built the system as a washable shirt. In previous prototypes they used a super capacitor, which worked well. But when the capacitor was charged, it would waste any extra energy available from the thermoelectric device. In the shirt prototype they used a secondary battery as a storage device that constantly recharged using body heat. That cut out the waste and enabled them to shrink the device even more. Combining other forms of generation with smart storage systems will likely be the ways that body-heat- powered devices become practical. At MIT, researchers are working on improving the efficiency of the circuitry that harnesses the minute amounts of power generated by standard thermoelectric generators. Scientists Anantha Chandrakasan, director of MIT's Microsystems Technology Laboratories, and his colleague Yogesh Ramadass have created extremely efficient circuitry in an EKG sensor with a built-in processor and wireless radio.
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There's even greater potential in improving the efficiency of thermoelectric generators. Currently, a thermoelectric generator currently can only convert 0.4% of the heat energy into usable electrical power. With this efficiency, if you were to cover all of your body with thermoelectric generators you could produce 0.5 Watts of energy. This would feel extremely cold and would hardly be enough to power a cellphone. There is research being done by the U.S. Department of Energy and the University of California-Berkeley on developing more efficient thermoelectric generators. MIT Professor Peter Hagelstein published a paper in November that showed a way to improve the efficiency of thermoelectric generators by up to 4 times in practice and up to 9 times in theory. Devices with that kind of efficiency could be used anywhere there is wasted heat--on the walls of power plants or lining the hoods of automobiles. A company that is closely related to MIT, MTPV, is starting to work on commercializing Hagelstein's ideas.
- http://medgadget.com/archives/2007/10/wireless_eeg_powered_by_body_heat.html October 2007
Wireless EEG Powered by Body Heat
This autonomous electroencephalogram system, powered by body heat, is another interesting device developed by the IMEC, a Belgium/Netherlands nanotechnologies research center.
Here's more about this prototype's technology:
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Transparent & Flexible Electronics The entire system is wearable and integrated into a headband. The small size, low power consumption of only 0.8mW and autonomous operation increase the patient's autonomy and quality of life. Potential applications are detection of imbalance between the two halves of the brain, detection of certain kinds of brain trauma and monitoring of brain activity. The EEG system uses IMEC's proprietary ultra-low power biopotential readout ASIC to extract high-quality EEG signals with micro-power consumption. A low-power digital signal-processing block encodes the extracted EEG data which is sent to a PC via a 2.4GHz wireless radio. The whole system consumes only 0.8mW. The thermoelectric generator is mounted on the forehead and converts the heat flow between the skin and air into electrical power. The generator is composed of 10 thermoelectric units interconnected in a flexible way. At room temperature, the generated power is about 2-2.5mW or 0.03mW/cm2 which is the theoretical limit of power generation on human skin. Higher power generation would cause an uncomfortable sense of cold. The EEG system is operational in less than one minute after switching on the device. Future research targets further reduction of the power consumption of the different system components including the radio and processor. Also, a semiconductor process for manufacturing thermopiles is under development. This will allow a significant reduction of the production cost.
- http://www.research.a-star.edu.sg/research/6218 Microfabrication: The power of heat Published online September 2010
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- http://technicalstudies.youngester.com/2010/06/paper-electricity-generated-by-human.html Electricity Generated by Human Body
A resting male can put out between 100 and 120 watts of energy, in theory enough to power many of the electronics you use, such as your Nintendo Wii (14 watts), your cellphone (about 1 watt) and your laptop (45 watts). Eighty percent of body power is given off as excess heat. …. A thermoelectric device placed on skin will generate power as long as the ambient air is at a lower temperature than the body. A patch of material one square centimeter in area can produce up to 30 microwatts. Place these generators side by side to multiply the amount of power being harvested. …. A human body constantly generates heat as a useful side effect of metabolism. However, only a part of this heat is dissipated into the ambient as a heat flow and infrared radiation, the rest of it is rejected in a form of water vapor. Furthermore, only a small fraction of the heat flow can be used in a wearer’s friendly and unobtrusive energy scavenger. (For example, nobody would accept a large device on his/her face. Therefore, the heat flow from it practically cannot be used.) At last, due to the laws of thermodynamics, the heat flow cannot be effectively converted it into electricity. However, a human being generates more than 100 W of heat; therefore, a quite useful electrical power still can be obtained using a person as a heat generator. The tool for converting heat flow into electricity is a thermoelectric generator (TEG), the heart of which is a thermopile. Typically, only a few watts of heat flow can be harvested unobtrusively on a person and thermoelectrically converted into several milliwatts in a form of electricity. If we recall that watches consume 1000 times less, it is fairly good power. Moreover, PV cells of the same area typically generate much less power because not much light is available indoors, where the authors and the reader of this paper are resting now. The human body is not a perfect heat generator as a heat supply for a wearable TEG. The body has high thermal resistance; therefore, the heat flow is quite limited. This is explained by the fact that warm-blooded animals have received in the process of evolution a very effective thermal management. This includes a very high thermal resistance of the body at ambient temperatures below 20–25 °C if the skin temperature decreases below thermal comfort.1,2 As a result, not much heat is dissipated from the skin and only about 3–5 mW/cm2 is available indoors, on average.
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- http://www.sciencedaily.com/releases/2008/04/080412172006.htm Wireless EEG System Self-Powered By Body Heat And Light ScienceDaily (April 2008)
- http://www.ecofriend.org/entry/texas-instruments-to-manufacture-chips-powered-by-body-heat Texas Instruments to manufacture chips powered by body heat Arpita Mukherjee | Feb 2008
Imagine the day that will come when in order to recharge the batteries of your mobile phone you only have to hold it in your grasp for a few minutes saving a bit of your electricity bill. This is exactly what will be achieved by a new concept chip designed by Texas Instruments. The energy efficient chip is capable of functioning at 0.3 volts of energy that can be provided by any small heat source; even by body heat. This chip is expected to lengthen the life span of batteries in mobile phones, implantable medical devices and sensors. The energy efficient chip is the handiwork of Joyce Kwong, a graduate student of MIT and Professor Anantha Chandrakasan of MIT, will be ready for commercial application within the next five years. To enable the chip to work at 0.3V energy the memory and logic circuits currently prevalent with the existing 1V chips need to be redesigned. Instead of using a separate converter, there will be an inbuilt DC-to-DC converter that would help to reduce the voltage. It is a challenge to researchers to develop chips capable of functioning at low power as at very low power levels the imperfections in the silicon become more apparent.
- http://www.gizmowatch.com/entry/electricity-from-body-heat-ultimate-solution-for-power-hungry-gizmos/ Electricity from body heat - Ultimate solution for power-hungry gizmos Bharat | August 2007
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Piezoelectric - http://www.memsinvestorjournal.com/2010/04/microstructured-piezoelectric-shoe-power-generator-outperforms-batteries.html Microstructured piezoelectric shoe power generator outperforms batteries by Ville Kaajakari, Ph.D. Assistant Professor, Louisiana Tech University
Energy harvesting is an attractive way to power MEMS sensors and locator devices such as GPS; however, the power harvesting technologies often fall short in terms of power output. For example, vibratory MEMS generators might give out only microwatts of electrical power. While this may be sufficient for emerging ultra low power sensors, many current applications require milliwatt power levels. As an example, commercially available running sensors for shoes consume over 100 uW of electrical power and requirements for GPS locators are even higher. Piezoelectric transducers generate electrical charge when compressed. This makes piezoelectric materials especially advantageous for power harvesting as they do not require bias voltage for operation. In principle, a piezoelectric transducer together with two rectifying diodes is sufficient for generating dc output voltage. The shoe power generator that our group has developed is based on a low-cost polymer transducer that has metallized surfaces for electrical contact. Unlike the conventional ceramic transducers, the plastic-based generator is soft and robust matching the properties of regular shoe fillings. The transducer can therefore replace the regular heel shock absorber with no loss in user experience. A significant challenge in harvesting piezoelectric energy is that piezoelectic materials are optimal for generating high voltages but provide only a low current output. The polymer used in the shoe transducer provides over 5 mJ of energy per step but at voltages too large (>50 V) to be directly used in low power sensors. A breakthrough in piezoelectric power generation is the new voltage regulation circuits that we developed at Louisiana Tech University that efficiently converts the piezoelectric charge into a usable voltage. A conversion circuit coverts the high voltage to a regulated 3 V output for charging batteries or for directly powering electronics at better than 70% conversion efficiency. Combined with the polymer transducer, the regulation circuit gives time-averaged power of 2 mW per shoe during a regular walk. The generated power output can be compared to typical storage capacity of 30 mAh for lithium coin/button cells -- with an average current consumption 0.5 mA, a miniature coin cell is depleted in less than three days whereas the shoe power generator gives power output as long as the user keeps walking. The total energy output can therefore easily surpass conventional batteries. In addition to running sensors and inertial navigation, the show power generator can be used to power RF transponders, GPS receivers, and locator tags that require a milliwatt power source.
- http://www.explainthatstuff.com/piezoelectricity.html Text copyright ÂŠ Chris Woodford 2009. All rights reserved.
Piezoelectricity You've probably used piezoelectricity (pronounced "pee-ay-zo-electricity") quite a few times today. If you've got a quartz watch, piezoelectricity is what helps it keep regular time. If you've been writing a letter or an essay on your computer with the help of voice recognition software, the microphone you spoke into probably used piezoelectricity to turn the sound energy in your voice into electrical signals your computer could interpret. If you're a bit of an audiophile and like listening to music on vinyl, your gramophone would have been using piezoelectricity to "read" the sounds from your LP records. Piezoelectricity (literally, "pressing electricity") is much simpler than it sounds: it just means using crystals to convert mechanical energy into electricity or viceversa. Let's take a closer look at how it works and why it's so useful!
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Transparent & Flexible Electronics What is piezoelectricity? Squeeze certain crystals (such as quartz) and you can make electricity flow through them. The reverse is usually true as well: if you pass electricity through the same crystals, they "squeeze themselves" by vibrating back and forth. That's pretty much piezoelectricity in a nutshell but, for the sake of science, let's have a formal definition: Piezoelectricity (also called the piezoelectric effect) is the appearance of an electrical potential (a voltage, in other words) across the sides of a crystal when you subject it to mechanical stress (by squeezing it). In practice, the crystal becomes a kind of tiny battery with a positive charge on one face and a negative charge on the opposite face; current flows if we connect the two faces together to make a circuit. In the reverse piezoelectric electric, a crystal becomes mechanically stressed (deformed in shape) when a voltage is applied across its opposite faces. What causes piezoelectricity?
What scientists mean by a crystal: the regular, repeating arrangement of atoms in a solid. The atoms are essentially fixed in place but can vibrate slightly.
Think of a crystal and you probably picture balls (atoms) mounted on bars (the bonds that hold them together), a bit like a climbing frame. Now, by crystals, scientists don't necessarily mean intriguing bits of rock you find in gift shops: a crystal is the scientific name for any solid whose atoms or molecules are arranged in a very orderly way based on endless repetitions of the same basic atomic building block (called the unit cell). So a lump of iron is just as much of a crystal as a piece of quartz. In a crystal, what we have is actually less like a climbing frame (which doesn't necessarily have an orderly, repeating structure) and more like threedimensional, patterned wallpaper.
Quartzâ€”probably the best known piezoelectric material. Photo by courtesy of US Geological Survey.
In most crystals (such as metals), the unit cell (the basic repeating unit) is symmetrical; in piezoelectric crystals, it isn't. Normally, piezoelectric crystals are electrically neutral: the atoms inside them may not be symmetrically arranged, but their electrical charges are perfectly balanced: a positive charge in one place cancels out a negative charge nearby. However, if you squeeze or stretch a piezoelectric crystal, you deform the structure, pushing some of the atoms closer together or further apart, upsetting the balance of positive and negative, and causing net electrical charges to appear. This effect carries through the whole structure so net positive and negative charges appear on opposite, outer faces of the crystal. The reverse-piezoelectric effect occurs in the opposite way. Put a voltage across a piezoelectric crystal and you're subjecting the atoms inside it to "electrical pressure." They have to move to rebalance themselvesâ€”and
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Transparent & Flexible Electronics that's what causes piezoelectric crystals to deform (slightly change shape) when you put a voltage across them. How piezoelectricity works 1. Normally, the charges in a piezoelectric crystal are exactly balanced, even if they're not symmetrically arranged. 2. The effects of the charges exactly cancel out, leaving no net charge on the crystal faces. (More specifically, the electric dipole momentsâ€”vector lines separating opposite chargesâ€”exactly cancel one another out.) 3. If you squeeze the crystal you force the charges out of balance. 4. Now the effects of the charges (their dipole moments) no longer cancel one another out and net positive and negative charges appear on opposite crystal faces. By squeezing the crystal, you've produced a voltage across its opposite facesâ€”and that's piezoelectricity!
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Nanowires - http://www.nature.com/nature/journal/v451/n7175/abs/nature06381.html Enhanced thermoelectric performance of rough silicon nanowires Nature 451, 163-167 (10 January 2008) | doi:10.1038/nature06381; Received 7 June 2007; Accepted 9 October 2007 Allon I. Hochbaum1,5, Renkun Chen2,5, Raul Diaz Delgado1, Wenjie Liang1, Erik C. Garnett1, Mark Najarian3, Arun Majumdar2,3,4 & Peidong Yang1,3,4 5. Department of Chemistry, 6. Department of Mechanical Engineering, 7. Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA 8. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA 9. These authors contributed equally to this work. Correspondence to: Arun Majumdar2,3,4Peidong Yang1,3,4 Correspondence and requests for materials should be addressed to A.M. (Email: firstname.lastname@example.org) and P.Y. (Email: email@example.com).
Approximately 90 per cent of the world's power is generated by heat engines that use fossil fuel combustion as a heat source and typically operate at 30–40 per cent efficiency, such that roughly 15 terawatts of heat is lost to the environment. Thermoelectric modules could potentially convert part of this low-grade waste heat to electricity. Their efficiency depends on the thermoelectric figure of merit ZT of their material components, which is a function of the Seebeck coefficient, electrical resistivity, thermal conductivity and absolute temperature. Over the past five decades it has been challenging to increase ZT > 1, since the parameters of 1 ZT are generally interdependent . While nanostructured thermoelectric materials can increase ZT >, the materials (Bi, Te, Pb, Sb, and Ag) and processes used are not often easy to scale to practically useful dimensions. Here we report the electrochemical synthesis of large-area, wafer-scale arrays of rough Si nanowires that are 20–300 nm in diameter. These nanowires have Seebeck coefficient and electrical resistivity values that are the same as doped bulk Si, but those with diameters of about 50 nm exhibit 100-fold reduction in thermal conductivity, yielding ZT = 0.6 at room temperature. For such nanowires, the lattice contribution to thermal conductivity approaches the amorphous limit for Si, which cannot be explained by current theories. Although bulk Si is a poor thermoelectric material, by greatly reducing thermal conductivity without much affecting the Seebeck coefficient and electrical resistivity, Si nanowire arrays show promise as highperformance, scalable thermoelectric materials.
- http://www.sciencedaily.com/releases/2008/01/080110161823.htm Body Heat To Power Cell Phones? Nanowires Enable Recovery Of Waste Heat Energy Energy now lost as heat during the production of electricity could be harnessed through the use of silicon nanowires synthesized via a technique developed by researchers with the U.S. Department of Energy's (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) at Berkeley. Copyright © 1995-2008 ScienceDaily LLC
- http://spie.org/x20171.xml Energy harvesting for self-powered nanosystems Zhong Lin (Z.L.) Wang
Energy from sources such as body movement or blood flow is converted to electrical energy by deforming piezoelectric semiconducting nanowires. 25 March 2008, SPIE Newsroom. DOI: 10.1117/2.1200801.1040
Developing novel technologies for wireless nanodevices and nanosystems is of critical importance for in situ, real-time and implantable biosensing and defense applications, and even wearable personal electronics. A nanodevice requires a power source, which may be provided directly or indirectly by a battery. But it is highly desirable for wireless devices to be self-powered. That requires exploring innovative nanotechnologies for converting mechanical, vibration, and hydraulic energy into electric energy for battery-free nanodevices. 74 Massimo Marrazzo - biodomotica.com
Transparent & Flexible Electronics We have demonstrated an innovative approach for converting mechanical energy into electricity using piezoelectric zinc oxide (ZnO) nanowires that can be grown on any substrate (e.g., metals, ceramics, polymers, and textile fibers) of any shape.
Schematic diagram showing the DC nanogenerator built using aligned ZnO nanowire arrays with a zigzag top electrode. The nanogenerator is driven by an external ultrasonic wave or mechanical vibration, and the output current is continuous. The lower plot is the output from a nanogenerator with the ultrasonic wave on and off. 2 The output current reached 600nA for a 3mm nanogenerator. The principle and technology demonstrated here have the potential to convert energy from mechanical movement (such as body motion, muscle stretching, and blood pressure), vibrations (such as acoustic and ultrasonic waves), and hydraulic movement (such as flow of body fluid and blood, or contraction of blood vessels) into electrical energy to power nanodevices and nanosystems. Relevant applications include implantable biosensing, wireless and remote sensing, nanorobotics, microelectromechanical systems, and sonic wave detection. This research was supported by the National Science Foundation, NASA, the Defense Research Projects Agency, and the National Institutes of Health. Thanks to Xudong Wang, Jinhui Song, and Jin Liu for their contribution.
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Transparent & Flexible Electronics - http://gtresearchnews.gatech.edu/self-powered-nanosensors/ Self-Powered Nanosensors: Researchers Use Improved Nanogenerators to Power Sensors Based on Zinc Oxide Nanowires Writer: John Toon - Georgia Institute of Technology
By combining a new generation of piezoelectric nanogenerators with two types of nanowire sensors, researchers have created what are believed to be the first self-powered nanometer-scale sensing devices that draw power from the conversion of mechanical energy. The new devices can measure the pH of liquids or detect the presence of ultraviolet light using electrical current produced from mechanical energy in the environment.
Figure shows (a) Fabrication of a vertical-nanowire integrated nanogenerator (VING), (b) Design of a lateralnannowire integrated nanogenerator (LING) array, (c) Scanning electron microscope image of a row of laterally-grown zinc oxide nanowire arrays, and (d) Image of the LING structure. (Click image for highresolution version. Credit: Zhong Lin Wang) The alternating current output of the nanogenerators depends on the amount of strain applied. “At a strain rate of less than two percent per second, we can produce output voltage of 1.2 volts,” said Wang. “The power output is matched with the external load.” Lateral nanogenerators integrating 700 rows of zinc oxide nanowires produced a peak voltage of 1.26 volts at a strain of 0.19 percent. In a separate nanogenerator, vertical integration of three layers of zinc oxide nanowire arrays produced a peak power density of 2.7 milliwatts per cubic centimeter.
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Printed Memory http://www.thinfilm.se/news/38-press-releases/220-thinfilm-works-with-parc-to-develop-next-generation-printed-memory-solutions
Thinfilm Works with PARC to Develop Next-Generation Printed Memory Solutions November 4th, 2010
Thinfilm (Thin Film Electronics ASA), a provider of advanced printed memory technology, and PARC (Palo Alto Research Center Incorporated), a premier center for commercial innovation, today announced that they are working together to provide next-generation memory technology enabled through printed electronics.
Thinfilm’s technology is based on using a ferroelectric polymer as the functional memory material sandwiched between two sets of electrodes in a passive matrix – each crossing of metal lines defines a memory cell. The memory function is based on an intrinsic mechanism related to orientation of the polymer chains. The polymer chains can be oriented in two different ways representing “0” and “1”. Each state is stable without application of an external field which means that information in the memory will not be lost when the power is turned off. This is referred to as a non-volatile memory. The intrinsic character of the polymer means that the technology is extremely scalable. Thinfilm has demonstrated 110 nm cells and shown that no lower limits Massimo Marrazzo - biodomotica.com 77
Transparent & Flexible Electronics could be found. An additional important characteristic of the technology is that it is based on non-toxic TM materials. This is very important in realizing our Memory Everywhere vision The Thinfilm-patented passive matrix is the “Holy grail” of memory architectures that dispenses with the need of active circuitry within the memory cell. This enables ultimate packing for high density memories as well as the possibility to stack memory layers on top of each other. The passive array memory architecture allows the memory portion to be separate from the read/write electronics enabling stand alone application without integration with printed logic.
- http://www.thinprofiletech.com/?p=46 Custom Printed Circuits with Embedded Power The TPT Advantage Why design the circuit to fit the battery? With the Embedded Power Platform® and TPT’s customizable battery technology, we design the battery to fit the circuit and its product form factor requirements. By printing the battery in-line with the circuit, we deliver a more robust solution that delivers more capacity at lower price.
Custom Design and Manufacture With manual sheet-fed, automatic sheet-fed, and web roll-to-roll presses, TPT can tailor the size of each run to the opportunity or substrate used, and easily scale up when demand rises. We handle a large variety of substrates and conductive materials in both sheet and web format. Best of all, as pioneers in the field of printed electronics, we can put our knowledge and experience to work for you. Battery Specifications Property
Battery Chemistry Cathode Anode Voltage Capacity Self-Discharge Durability and Flexibility Operating Temperature Storage Temperature Thickness Battery Tab Connection Form Factor Production Status
Carbon Zinc Manganese Dioxide Zinc 1.5 V, 3.0 V, 4.5 V, 6.0 V Up to 2.5 mAh/cm2, depending on formulation and thickness <1% per month ISO 7810 Compliant -10°C (15°F) to 60°C (140°F) -20°C (-5°F) to 40°C (105°F) 0.1 mm (100 microns; 4 mils) to 1.0 mm (1000 microns; 40 mils) Anisotropic conductive film (ACF) or ultrasonic weld Virtually unlimited Mass production
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Printed Antennas - http://www.media.rice.edu/media/NewsBot.asp?MODE=VIEW&ID=13899 Nano-based RFID tag, you're it Rice, Korean collaboration produces printable tag that could replace bar codes 3/18/2010
RFID tags printed through a new roll-to-roll process could replace bar codes CREDIT: GYOU-JIN CHO/SUNCHON NATIONAL UNIVERSITY
Rice researchers, in collaboration with a team led by Gyou-jin Cho at Sunchon National University in Korea, have come up with an inexpensive, printable transmitter that can be invisibly embedded in packaging. It would allow a customer to walk a cart full of groceries or other goods past a scanner on the way to the car; the scanner would read all items in the cart at once, total them up and charge the customer's account while adjusting the store's inventory. The technology reported in the March issue of the journal IEEE Transactions on Electron Devices is based on a carbon-nanotube-infused ink for ink-jet printers first developed in the Rice lab of James Tour, the T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of Massimo Marrazzo - biodomotica.com 79
Transparent & Flexible Electronics computer science. The ink is used to make thin-film transistors, a key element in radio-frequency identification (RFID) tags that can be printed on paper or plastic. "We are going to a society where RFID is a key player," said Cho, a professor of printed electronics engineering at Sunchon, who expects the technology to mature in five years. Cho and his team are developing the electronics as well as the roll-to-roll printing process that, he said, will bring the cost of printing the tags down to a penny apiece and make them ubiquitous. Printable RFIDs are practical because they're passive. The tags power up when hit by radio waves at the right frequency and return the information they contain. "If there's no power source, there's no lifetime limit. When they receive the RF signal, they emit," Tour said. Tour allayed concerns about the fate of nanotubes in packaging. _The amount of nanotubes in an RFID tag is probably less than a picogram. That means you can produce one trillion of them from a gram of nanotubes — a miniscule amount. Our HiPco reactor produces a gram of nanotubes an hour, and that would be enough to handle every item in every Walmart. "In fact, more nanotubes occur naturally in the environment, so it's not even fair to say the risk is minimal. It's infinitesimal."
- http://www.electroscience.com/smartcardappnotes.html New Flexible Polymer Silver from ESL ElectroScience The rapid growth in the use of these devices has necessitated the search for a fast, cost-efficient, seamless manufacturing route. Reel to reel technology, such as is used in the newspaper industry, is considered to be faster than traditional methods of handling substrate material. Institutes like Fraunhofer IZM are preparing smart cards/labels using continuous production lines. Central to the success of this manufacturing route is the use of polymer based thick-film pastes that can be screen-printed using specially adapted printers that accept a reel to reel process.
Smart label from the Fraunhofer Institut Zuverlässigkeit und Mikrointegration (IZM) in Munich, Germany
Fraunhofer IZM reel to reel process The choice of substrate material allows for relatively high processing temperatures (up to 150 °C for the few minutes it takes to cure the paste). Line/space resolutions of 200 µm have been achieved quite easily and the spread in resistance values of tracks printed at this thickness are good. The resistivity of ESL1901-S is 15-20 mΩ/square at a thickness of 25 µm when cured at 80 °C for two hours. The substrate chosen is thee plastic that is used for credit cards. It may well be that this resistivity is too high for some applications and ESL is working on a lower-resistivity polymer silver. While silver is the metal that has been chosen to produce the pioneer product, other metals are being considered for inclusion in a polymer matrix to make a screenprintable conductor for antennas. Copyright © 2004-2008 ESL ElectroScience. All rights reserved
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Wireless technologies Wi-Fi
- http://en.wikipedia.org/wiki/Wi-Fi Wi-Fi is the trade name for a popular wireless technology used in home networks, mobile phones, video games and more. Wi-Fi networks have limited range. A typical Wi-Fi home router using 802.11b or 802.11g with a stock antenna might have a range of 32 m (120 ft) indoors and 95 m (300 ft) outdoors. Range also varies with frequency band. Wi-Fi in the 2.4 GHz frequency block has slightly better range than Wi-Fi in the 5 GHz frequency block. Outdoor range with improved (directional) antennas can be several kilometres or more with line-of-sight. Wi-Fi performance decreases roughly quadratically as the range increases at constant radiation levels. 802.11 network standards Approximate indoor Approximate Outdoor Bandwidth Data rate per stream Modulation range range (MHz) (Mbit/s) (m) (ft) (m) (ft) 20 1, 2 DSSS, FHSS 20 66 100 330 35 115 120 390 6, 9, 12, 18, 24, 36, 48, 20 OFDM 54 --5,000 16,000 20 5.5, 11 DSSS 38 125 140 460 6, 9, 12, 18, 24, 36, 48, 2.4 20 OFDM, DSSS 38 125 140 460 54 7.2, 14.4, 21.7, 28.9, 20 70 230 250 820 43.3, 57.8, 65, 72.2[z] 2.4/5 OFDM 15, 30, 45, 60, 90, 120, 40 70 230 250 820 135, 150[z] y IEEE 802.11y-2008 extended operation of 802.11a to the licensed 3.7 GHz band. Increased power limits allow a range up to 5000m. As of 2009[update], it is only being licensed in the United States by the FCC. z Assumes Short Guard interval (SGI) enabled, otherwise reduce each data rate by 10%.
802.11 Freq. Protoco (GHz) l – 2.4 5 a 3.7[y] b 2.4 g
n • •
- http://en.wikipedia.org/wiki/WiMax WiMAX, the Worldwide Interoperability for Microwave Access, is a telecommunications technology that provides wireless data in a variety of ways, from point-to-point links to full mobile cellular type access. It is based on the IEEE 802.16 standard, which is also called WirelessMAN. WiMAX is a term coined to describe standard, interoperable implementations of IEEE 802.16 wireless networks, similar to the way the term Wi-Fi is used for interoperable implementations of the IEEE 802.11 Wireless LAN standard. However, WiMAX is very different from Wi-Fi in the way it works. A commonly-held misconception is that WiMAX will deliver 70 Mbit/s over 50 kilometers. In reality, WiMAX can do one or the other — operating over maximum range (50 km) increases bit error rate and thus must use a lower bitrate. Lowering the range allows a device to operate at higher bitrates. Typically, fixed WiMAX networks have a higher-gain directional antenna installed near the client (customer) which results in greatly increased range and throughput. Mobile WiMAX networks are usually made of indoor "customer premises equipment" (CPE) such as desktop modems, laptops with integrated Mobile WiMAX or other Mobile WiMAX devices. Mobile WiMAX devices typically have an omni-directional antenna which is of lower-gain compared to directional antennas but are more portable. In practice, this means that in a line-ofsight environment with a portable Mobile WiMAX CPE, speeds of 10 Mbit/s at 10 km could be delivered. However, in urban environments they may not have line-of-sight and therefore users may only receive 10 Mbit/s over 2 km. In current deployments, throughputs are often closer to 2 Mbit/s symmetric at 10 km with fixed WiMAX and a high gain antenna. It is also important to consider that a throughput of 2 Mbit/s can mean 2 Massimo Marrazzo - biodomotica.com 81
Transparent & Flexible Electronics Mbit/s, symmetric simultaneously, 1 Mbit/s symmetric or some asymmetric mix (e.g. 0.5 Mbit/s downlink and 1.5 Mbit/s uplink or 1.5 Mbit/s downlink and 0.5 Mbit/s uplink, each of which required slightly different network equipment and configurations. Higher-gain directional antennas can be used with a Mobile WiMAX network with range and throughput benefits but the obvious loss of practical mobility. Comparison with Wi-Fi Comparisons and confusion between WiMAX and Wi-Fi are frequent, possibly because both begin with the same two letters, are based upon IEEE standards beginning with "802.", and both have a connection to wireless connectivity and the Internet. Despite this, the two standards are aimed at different applications. · WiMAX is a long-range system, covering many kilometers that typically uses licensed spectrum (although it is possible to use unlicensed spectrum) to deliver a point-to-point connection to the Internet from an ISP to an end user. Different 802.16 standards provide different types of access, from mobile (similar to data access via a cellphone) to fixed (an alternative to wired access, where the end user's wireless termination point is fixed in location.) · Wi-Fi is a shorter range system, typically tens of meters, that uses unlicensed spectrum to provide access to a network, typically covering only the network operator's own property. Typically Wi-Fi is used by an end user to access their own network, which may or may not be connected to the Internet. If WiMAX provides services analogous to a cellphone, Wi-Fi is more analogous to a cordless phone. It's important to note, however, that free community wi-fi networks have shown that with proper antennas, wi-fi can have very long ranges. · WiMAX and Wi-Fi have quite different Quality of Service (QoS) mechanisms. WiMAX uses a mechanism based on setting up connections between the Base Station and the user device. Each connection is based on specific scheduling algorithms, which means that QoS parameters can be guaranteed for each flow. Wi-Fi has introduced a QoS mechanism similar to fixed Ethernet, where packets can receive different priorities based on their tags. This means that QoS is relative between packets/flows, as opposed to guaranteed. · WiMAX is highly scalable from what are called "femto"-scale remote stations to multi-sector 'maxi' scale base that handle complex tasks of management and mobile handoff functions and include MIMO-AAS smart antenna subsystems. Due to the ease and low cost with which Wi-Fi can be deployed, it is sometimes used to provide Internet access to third parties within a single room or building available to the provider, often informally, and sometimes as part of a business relationship. For example, many coffee shops, hotels, and transportation hubs contain Wi-Fi access points providing access to the Internet for customers.
Bluetooth is a wireless protocol utilizing short-range communications technology facilitating data transmission over short distances from fixed and/or mobile devices, creating wireless personal area networks (PANs). Maximum Permitted Power mW(dBm)
Class 1 100 mW (20 dBm) ~100 meters Class 2 2.5 mW (4 dBm) ~10 meters Class 3 1 mW (0 dBm) ~1 meter In most cases the effective range of class 2 devices is extended if they connect to a class 1 transceiver, compared to pure class 2 network. This is accomplished by the higher sensitivity and transmission power of Class 1 devices. Version Version 1.2 Version 2.0 + EDR WiMedia Alliance (proposed) 82 Massimo Marrazzo - biodomotica.com
Data Rate 1 Mbit/s 3 Mbit/s 53 - 480 Mbit/s
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RFID - http://en.wikipedia.org/wiki/RFID Radio-frequency identification (RFID) is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders. An RFID tag is an object that can be applied to or incorporated into a product, animal, or person for the purpose of identification using radio waves. Some tags can be read from several meters away and beyond the line of sight of the reader. Most RFID tags contain at least two parts. One is an integrated circuit for storing and processing information, modulating and demodulating a (RF) signal, and other specialized functions. The second is an antenna for receiving and transmitting the signal. Chipless RFID allows for discrete identification of tags without an integrated circuit, thereby allowing tags to be printed directly onto assets at a lower cost than traditional tags. RFID tags come in three general varieties:- passive, active, or semi-passive (also known as battery-assisted). Passive tags require no internal power source, thus being pure passive devices (they are only active when a reader is nearby to power them), whereas semi-passive and active tags require a power source, usually a small battery. Passive tags have practical read distances ranging from about 10 cm (4 in.) (ISO 14443) up to a few meters (Electronic Product Code (EPC) and ISO 18000-6), depending on the chosen radio frequency and antenna design/size. But thanks to deep-space technology, that distance is now 600 feet. Due to their simplicity in design they are also suitable for manufacture with a printing process for the antennas. The lack of an onboard power supply means that the device can be quite small: commercially available products exist that can be embedded in a sticker, or under the skin in the case of low frequency (LowFID) RFID tags.
Many active tags today have operational ranges of hundreds of meters, and a battery life of up to 10 years. Active tags may include larger memories than passive tags, and may include the ability to store additional information received from the reader. Special active RFID tags may include temperature sensors. Temperature logging is used to monitor the temperature profile during transportation and storage of perishable goods as fresh produce or certain pharmaceutical products. Other sensor types are combined with active RFID tags, including humidity, shock/vibration, light, radiation, temperature, pressure and concentrations of gases like ethylene. Semi-passive tags are similar to active tags in that they have their own power source, but the battery only powers the microchip and does not power the broadcasting of a signal. The response is usually powered by means of backscattering the RF energy from the reader, where energy is reflected back to the reader as with passive tags. An additional application for the battery is to power data storage. If energy from the reader is collected and stored to emit a response in the future, the tag is operating active Whereas in passive tags the power level to power up the circuitry must be 100 times stronger than with active or semi-active tags, also the time consumption for collecting the energy is omitted and the response comes with shorter latency time. The battery-assisted reception circuitry of semi-passive tags leads to greater sensitivity than passive tags, typically 100 times more. The enhanced sensitivity can be leveraged as increased range (by one magnitude) and/or as enhanced read reliability (by reducing bit error rate at least one magnitude). The enhanced sensitivity of semi-passive tags place higher demands on the reader concerning separation in more dense population of tags. Because an already weak signal is backscattered to the reader from a larger number of tags and from longer distances, the separation requires more sophisticated anti-collision concepts, better signal processing and some more intelligent assessment which tag might be where. For passive tags, the reader-to-tag link usually fails first. For semi-passive tags, the reverse (tag-to-reader) link usually collides first. Semi-passive tags have three main advantages 1) Greater sensitivity than passive tags 2) Longer battery powered life cycle than active tags. 3) Can perform active functions (such as temperature logging) under its own power, even when no reader is present for powering the circuitry. - http://www.gentag.com/technology.html A particular focus area for Gentag using RFID cell phones are diagnostic applications. RFID sensors can be integrated into low cost, non-invasive, disposable diagnostic devices such as _smart" disposable wireless skin patches or personal drug delivery systems and read directly with a cell phone under existing Gentag/Altivera patents. Copyright ÂŠ 2008 Gentag, Inc
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Nanotube Radio - http://www.lbl.gov/Tech-Transfer/techs/lbnl2431.html Nanotube Radio for Communications and Medical Applications Alex Zettl and his team at Berkeley Lab have invented and constructed a fully functional, integrated radio receiver based on a single carbon nanotube (CNT). The nanotube serves simultaneously as all essential components of a radio -- antenna, tunable band-pass filter, amplifier, and demodulator—to convert an electromagnetic signal into a mechanical signal and then into an electrical signal amplified and demodulated to produce audible sound. The radio is several orders of magnitude smaller than previous radios due to the use of the nanotube's electro-mechanical movement instead of a conventional radio's electrical components. Berkeley Lab's nanotube radio promises smaller, less complex, and lower power-requirement wireless communication devices. The radio can be configured to be either a receiver or a transmitter. Because its scale is compatible with biological systems, the radio also offers unique opportunities for radio controlled devices to be placed in the body for various diagnostic, therapeutic, monitoring, and sensory (auditory and visual) functions. In addition, the nanotube may be altered by contact with particles at the atomic scale that change the resonance frequency of the nanotube. This change may be used to detect the impingement of particles, whether solid or gaseous, to create a highly sensitive, inexpensive mass spectrometer or gas sensor. A mass spectrometer constructed using this technology can detect the mass of less than a single hydrogen atom. The nanotube application could also measure the masses of large molecules or those that are difficult to ionize, e.g., DNA, proteins, because it does not rely on ionizing a particle to make measurements, as in traditional mass spectrometers.
(a) Schematic of the nanotube radio. Radio transmissions tuned to the nanotube's resonance frequency force the charged nanotube to vibrate. Field emission of electrons from the tip of the nanotube is used to detect the vibrations and also amplify and demodulate the signal. A current measuring device, such as a sensitive speaker, monitors the output of the radio. (b) Transmissionelectron micrographs of a nanotube radio off resonance (top) and on resonance (bottom) during a radio transmission.
APPLICATIONS OF TECHNOLOGY: · All-in-one radio receiver for cell phones/wireless networks/GPS and other electronic devices · Radio controlled devices that can exist inside the body, e.g. used as drug release triggers, diagnostic instrumentation, interfacing with muscle or brain function · Ultra small hearing aid · RF antenna, tunable pass filter, amplifier, or demodulator · Mass spectrometer · Chemical sensor FOR MORE INFORMATION: Jensen, K., Weldon, J., Garcia, H., Zettl, A., Nanotube Radio, Nano Letters, Vol. 0, No. 0, A-D
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Transparent & Flexible Electronics - http://www.lbl.gov/Science-Articles/Archive/MSD-nanoradio.html Published patent application WO/2009/048695 available at http://www.wipo.int/. Available for licensing.
- http://www.technologyreview.com/printer_friendly_article.aspx?id=20244 Copyright Technology Review 2011
- http://www.lbl.gov/Science-Articles/Archive/MSD-nanoradio.html Berkeley Researchers Create First Fully Functional Nanotube Radio
Block diagram for a traditional radio. All four essential components of a radio, antenna, tuner, amplifier, and demodulator may be implemented with a single carbon nanotube.
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Video - http://www.lbl.gov/Science-Articles/Archive/assets/images/2007/Oct/30-Tue/nanoradio-starwars.mov This QuickTime video was recorded on the nanotube radio using a Transmission Electron Microscope. At the beginning of the video, the nanotube radio is tuned to a different frequency than that of the transmitted radio signal so the nanotube does not vibrate and only static noise can be heard. As the radio is brought into tune with the transmitted signal, the nanotube begins to vibrate, which blurs its image in the video but allows the music to become audible. The song is the theme music to Star Wars by John Williams.
- http://thefutureofthings.com/news/1185/nanoradio-smallest-radio-receiver-in-the-world.html Smallest Radio Receiver in the World
Radio evolution - the nanoradio is nineteen orders-of-magnitude smaller than the Philco vacuum tube radio from the 1930s (Credit: Berkeley / A. Zettl and K. Jensen) Copyright ÂŠ 2008 The Future of Things. All rights reserved
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S ou n d Ultrathin loudspeakers made from transparent and flexible carbon nanotube films, don't require any of the bulky magnets and sound cones of conventional speakers. - http://pubs.acs.org/doi/abs/10.1021/nl802750z Flexible, Stretchable, Transparent Carbon Nanotube Thin Film Loudspeakers Lin Xiao, Zhuo Chen, Chen Feng, Liang Liu, Zai-Qiao Bai, Yang Wang, Li Qian, Yuying Zhang, Qunqing Li, Kaili Jiang, Shoushan Fan Department of Physics & Tsinghua-Foxconn Nanotechnology Research Centre, Tsinghua University, Beijing 100084, People's Republic of China, and Department of Physics, Beijing Normal University, Beijing 100875, People's Republic of China Nano Lett., 2008, 8 (12), pp 4539—4545 DOI: 10.1021/nl802750z Publication Date (Web): October 29, 2008
We found that very thin carbon nanotube films, once fed by sound frequency electric currents, could emit loud sounds. This phenomenon could be attributed to a thermoacoustic effect (see page 92). The ultra small heat capacity per unit area of carbon nanotube thin films leads to a wide frequency response range and a high sound pressure level. On the basis of this finding, we made practical carbon nanotube thin film loudspeakers, which possess the merits of nanometer thickness and are transparent, flexible, stretchable, and magnet-free. Such a single-element thin film loudspeaker can be tailored into any shape and size, freestanding or on any insulating surfaces, which could open up new applications of and approaches to manufacturing loudspeakers and other acoustic devices. Copyright © 2008 American Chemical Society
Video Nanotube-based speaker plays music from an iPod beneath it. - http://www.natureasia.com/asia-materials/highlight.php?id=340 Carbon nanotubes: Loud and clear To make a loudspeaker from the films was extremely simple. _All that was needed were two electrodes attached to the carbon nanotube films through which the audio frequency voltage is applied," says Kaili Jiang from the research team. The sound output from the loudspeaker was clear and the acoustic performance relatively constant across the audible frequency spectrum.
A carbon nanotubes loudspeaker placed in front of an iPod to demonstrate the possible integration with display devices Xiao, L. et al. Flexible, stretchable, transparent carbon nanotubes thin film loudspeakers. Nano Lett. Doi:10.1021/nl802750z (2008). © 2008 Tokyo Institute of Technology
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Transparent & Flexible Electronics by Colin Barras © Copyright 2008 Reed Business Information Ltd.
Hot nanotube sheets produce music on demand Sheets made of carbon nanotubes behave like a loudspeaker when zapped with a varying electric current, say Chinese researchers. The discovery could lead to new generation of cheap, flat speakers.
Video - http://thefutureofthings.com/news/5967/flexible-transparent-nanotube-based-loudspeakers.html Flexible, Transparent Nanotube-Based Loudspeakers Researchers from Tsinghua University and Beijing University have recently developed a thin film based on carbon nanotubes (CNT) that could replace conventional magnetic loudspeakers. By applying an audio frequency current through the CNT, the loudspeaker can generate sound with wide frequency range, high sound pressure levels (SPL), and low total harmonic distortion (THD). The uniqueness of this advancement is that the films are flexible, stretchable, transparent, and can be tailored into many shapes and sizes, freestanding or placed on a variety of rigid or flexible insulating surfaces.
Flat flexible speakers - http://www2.warwick.ac.uk/newsandevents/pressreleases/new_flat_flexible
A groundbreaking new loudspeaker, less than 0.25mm thick, has been developed by University of Warwick engineers, it's flat, flexible, could be hung on a wall like a picture, and its particular method of sound generation could make public announcements in places like passenger terminals clearer, crisper, and easier to hear. Lightweight and inexpensive to manufacture, the speakers are slim and flexible: they could be concealed inside ceiling tiles or car interiors, or printed with a design and hung on the wall like a picture. All speakers work by converting an electric signal into sound. Usually, the signal is used to generate a varying magnetic field, which in turn vibrates a mechanical cone, so producing the sound. Warwick Audio Technology's FFL technology is a carefully designed assembly of thin, conducting and insulating, materials resulting in the development of a flexible laminate, which when excited by an electrical signal will vibrate and produce sound. The speaker laminate operates as a perfect piston resonator. The entire diaphragm therefore radiates in phase, forming an area source. The wave front emitted by the vibrating surface is phase coherent, producing a plane wave with very high directivity and very accurate sound imaging.
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Transparent & Flexible Electronics - http://blogs.discovermagazine.com/80beats/2008/11/05/paper-thin-nanotube-speakers-can-turn-up-the-volume/ Paper-Thin Nanotube Speakers Can Turn Up the Volume by Nina Bai November 5th, 2008
Next-generation loudspeakers could be as thin as paper, as clear as glass, and as stretchable as rubber. Chinese researchers have discovered that sheets of carbon nanotubes can amplify sound as loud as conventional speakers can. These nanotube speakers could eventually be used to add audio capabilities to windows, video screens, and clothing. "It is so wonderfully simple, that it brings up a strong wave of ‘Duh, why didn’t I think of that!’," says physical chemist Howard Schmidt at Rice University [Nature News]. The researchers made the speaker by aligning carbon nanotubes, each about 10 nanometers in diameters, into thin flexible sheets. When they applied an electric current with an audio frequency to the sheets, the sheets broadcast the sounds loud and clear. The researcher describe their device in Nano Letters. The physics behind the nanotube speakers is different from that of conventional speakers. Unlike standard loudspeakers that generate sound by vibrations in the surrounding air molecules, the nanotube speaker doesn’t emit vibrations. The team used a laser vibrometer to detect vibrations in the sheet, but found nothing [Physorg.com]. Instead, it generates sound much as lightning produces thunder. When an electric current is applied to the nanotubes, they heat and expand the air near them, creating sound waves. "The difference is that thunder is not a controlled discharge. With carbon nanotubes, you can control the sound and play music," [researcher Kaili] Jiang says [Nature News]. The phenomenon is known as the thermoacoustic effect. The thermally induced pressure oscillations can heat the speakers up to 80 °C but the researchers say temperatures s lightly above room temperature would be adequate for consumer applications. The basic idea of using the thermoacoustic effect to make speakers isn’t new. In the late 19th century, researchers built a "thermophone" out of thin sheets of metal, but it could only produce a whisper of a sound. The new nanotube speakers can produce sounds 20 to 30 decibels louder than the thermophone, thanks to the low heat capacity of the nanotubes. "A key parameter that determines the sound generation efficiency is the heat capacity per unit area," [explains Jiang]. Put simply, that’s a measure of how much heat energy must be applied to a material to raise its temperature. The heat capacity per unit area of a carbon nanotube sheet is 260 times smaller than that of a platinum foil sheet [New Scientist]. ©2008 discovermagazine.com
□□□□□ Carbon Nanotubes Speaker - http://www.physorg.com/news144939492.html Carbon nanotubes could act as an efficient music speaker November 3, 2008 by Lisa Zyga
Video Excerpt from a video of Lin Xiao´s nanotube music speaker. The speaker produces sound when a current passes through, due to a thermoacoustic effect. Credit: Lin Xiao, et al. (PhysOrg.com) -- While carbon nanotubes are widely praised for their strength and electrical properties, no one has thoroughly investigated their acoustic properties, until now. A team of Chinese researchers has found that zapping sheets of carbon nanotubes with an electric current causes the nanotubes to emit sound. The team, which consists of scientists Shoushan Fan and colleagues at Tsinghua University in Beijing, China, and Beijing Normal University, hope that the discovery could lead to the development of cheap, flat loudspeakers. Examples of carbon nanotubes´ musical abilities can be heard here and here.
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Transparent & Flexible Electronics To create the nanotube speaker, the researchers sent an audio frequency current through a thin sheet of carbon nanotubes, generating a sound. Unlike standard loudspeakers that generate sound by vibrations in the surrounding air molecules, the nanotube speaker doesn´t emit vibrations. The team used a laser vibrometer to detect vibrations in the sheet, but found nothing. Instead, the nanotube speaker likely works as a thermoacoustic device: when an alternating current passes through the sheet, the sheet experiences rapid temperature oscillations alternating between room temperature and 80 °C (176 °F). These temperature oscillations cause pressure oscillations in the surrounding air, producing the sound, while the nanotube sheet remains static. One advantage of this method is that, even if part of the nanotube sheet breaks, it should continue to emit sound, unlike conventional speakers. This thermoacoustic phenomenon was actually discovered in the late nineteenth century, when scientists passed a current through a thin foil to produce sound, leading to the invention of the "thermophone." Although the principle is the same, however, the nanotube sheet acts much more efficiently than foil because it doesn´t require nearly as much applied heat to increase its temperature. Specifically, the nanotube sheet´s heat capacity is 260 times smaller than platinum foil, making nanotubes 260 times more efficient and able to produce a louder sound. The Chinese researchers envision several interesting applications for the nanotube speakers. Because the nanotube sheets can be stretched to be visually transparent and still produce sound, they might be fitted over the front of an LCD screen to replace conventional speakers. Another possibility is incorporating the nanotube speakers into textiles to create musical clothes. More information: Xiao, Lin, et al. "Flexible, Stretchable, Transparent Carbon Nanotube Thin Film Loudspeakers." ASAP Nano Lett., ASAP Article, 10.1021/nl802750z. © 2009 PhysOrg.com
- http://www.gizmag.com/nanotube-sheets-for-stealthy-submarines/16231/ Nanotube sheets could lead to stealthier submarines By Ben Coxworth September 2, 2010
One of the sound-generating carbon nanotube sheets Two years ago, Chinese scientists coated one side of a flag with a thin sheet of nanotubes, then played a song using the flapping sheet-coated flag as a speaker. It was a demonstration of flexible speaker technology, in which nanotubes can be made to generate sound waves via a thermoacoustic effect – every time an electrical pulse is sent through the microscopic layer of nanotubes, it causes the air around them to heat up, which in turn creates a sound wave. Now, an American scientist has taken that technology underwater, where he claims it could allow submariners to detect other submarines, and to remain hidden themselves. Research scientist Ali Aliev, of the University of Texas at Dallas, has determined that the low-frequency sound waves created by carbon nanotube sheets can be used by sonar systems to determine the location, depth, and speed of underwater objects. Aliev and his team also determined that the sheets could be tuned to transmit specific frequencies that would cancel out certain noises... noises such as those that a submarine makes while passing through the water, for instance.
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One obstacle that Aliev had to overcome was the fact that the sheets do not do well in direct contact with water. The sheets can oxidize when in contact with water at high temperatures, the high surface tension and vibrational frequency of water causes the nanotubes to bundle into acoustically-poor ropes, and ocean water can cause the sheets to short circuit. On the plus side, however, the hydrophobic (water-repellent) nature of the sheets causes an air envelope to form around the nanotubes, which in turn acts as a kind of resonating chamber for the sound waves, boosting their strength. Be that as it may, the sheets still needed to be protected from the water. In order to do so, Aliev encapsulated them in thin, flat gas-filled containers with acoustically-transparent windows. As with the air envelopes, the resonance that resulted from the sound waves being generated in such an enclosed space proved to be a benefit – the encapsulated sheets were actually ten times more effective at transmitting low-frequency sound underwater than non-encapsulated sheets. The researchers also experimented with stacking the sheets several deep, but found that this negatively affected the desired thermoacoustics. The optimum arrangement turned out to be a layer of just two separated sheets, which received their electrical pulses alternately instead of simultaneously. The research has just been published in the journal Nano Letters.
- http://www.physorg.com/news195720997.html Nanotech Speakers Hold Promise for Sonar Uses June 14, 2010
Thin, almost transparent sheets of multi-walled (MWNT) nanotubes are connected to an electrical source, which rapidly heats the nanotubes causing a pressure wave in the surrounding air to produce sound. Led by Dr. Ali Aliev, a research scientist at the NanoTech Institute, the team discovered that nanotubes excel at producing low frequency sound waves, which are ideal for probing the depths of the ocean with sonar. The team also confirmed previous studies noting the ability of nanoscience speakers to cancel noise when tuned to the correct frequency — say, the rumble of a submarine. “Nanotube sheets can easily be deployed on curved surfaces, like the hull of a sub,” Aliev said. “They’re very light, about 20 microns thick, and they’re 99 percent porous. Layers of nanotube sheets can be built up, each with a different function, for sonar projector applications or for control of the boundary layer losses for marine vehicles. Meaning, periodically heating the skin of a sub—or even an airplane—warms the thin pocket of air around the vehicle and reduces friction and turbulence. Or, these underwater sound generators could cancel out the sonar signal being sent out by another sub, leaving the friendly sub undetected.” More information: Journal paper: http://dx.doi.org/ … 21/nl100235n
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Thermoacoustic effect - http://www.five-shades-of-green-energy.com/thermoacoustics.html Thermoacoustics work both ways. Simply put, heat makes sound, sound makes heat. Thermoacoustics is heat that makes noise and noise that makes heat. More specifically sound oscillations that transport heat or cold, both of which can be used to generate sound oscillations. A definition is in order – it’s the study of phenomena influenced by thermodynamics and acoustics.
Resonance - http://www.phys.unsw.edu.au/jw/musFAQ.html How can a resonating chamber amplify sounds? Let's compare a string on immoveable mountings (an unplugged electric guitar approaches this) with a string on an acoustic guitar. In the former, the bridge (almost) doesn't move, so no work is done by the string. The string itself is inefficient at moving air because it is thin and slips through the air easily, making almost no sound. So nearly all the energy of the pluck remains in the string, where it is gradually lost by internal friction. In contrast, the string on the acoustic guitar moves the belly of the instrument slightly. Even though the motion is slight, the belly is large enough to move air substantially and make a sound. So the string converts some of its energy to sound in the air. Consequently, its vibration decreases more rapidly than does that of a similar string on an electric guitar. (Internal losses in the string are still very important, however.) So there is no extra energy: the energy for the sound comes from the string. Which raises an obvious question: if there is no amplification, how does such a little vibration make such a lot of sound? The answer is that our ears are rather sensitive (see our page on decibels and hearing). Consequently, even a small energy (even less than a millijoule) over several seconds makes a reasonably loud sound. Copyright © 2008 Joe Wolfe
- http://en.wikipedia.org/wiki/Sound_box A sound box or sounding box, (sometimes written soundbox), is an open chamber in the body of a musical instrument which alters the instrument's tone quality by modifying the way the instrument resonates. The purpose of the sound box is to amplify the volume of the instrument. - http://en.wikipedia.org/wiki/Resonance_chamber A resonance chamber uses resonance to amplify sound. The chamber has interior surfaces which reflect an acoustic wave. When a wave enters the chamber, it bounces back and forth within the chamber with low loss (See standing wave). As more wave energy enters the chamber, it combines with and reinforces the standing wave, increasing its intensity (volume). - http://www.glenbrook.k12.il.us/gbssci/Phys/Class/sound/u11l4b.html Resonance and Standing Waves
□□□□□ - http://www.murata-northamerica.com/murata/murata.nsf/pages/08032010 Ultra-Thin Waterproof Piezoelectric Speaker Smyrna, GA, August 3, 2010 - Murata Electronics North America today announced the launch of the world's first ultra-thin waterproof piezoelectric speaker. With a thickness of only 0.9mm, this 19.5mm x 14.1mm speaker enables greater design freedom for the rapidly growing and evolving mobile market. The speaker achieves IPX7 grade waterproof protection without the need of a costly water proof acoustic membrane. Using just ordinary acoustic mesh and double sided tape to seal the speaker to the front cavity, this waterproof speaker application allows for decreased application costs, thin size, and good sound performance. The high torque nature of the speaker's piezoelectric motor also makes it idea for operation in very small and thin back cavities where dynamic speakers struggle to operate. As such, these features make the speaker ideal for mobile phones, music players, digital still cameras, digital video cameras, IC recorders, e-books and other mobile equipment. There have been numerous indicators that demonstrate the growing trend towards waterproofing mobile equipment. For example, of the 50 new Japanese mobile phone models announced in late 2010, almost one 92 Massimo Marrazzo - biodomotica.com
Transparent & Flexible Electronics in four were waterproof. This trend is aided by Murata's speaker ability to overcome the above mentioned technical and cost challenges. Specific speaker characteristics include an average sound pressure level of 92.0±3.0dB (1400Hz±20%, 5Vrms sine wave, 10cm) and a capacitance of 0.9µF±30%. “We developed this waterproof speaker based on feedback from our customers and market trends," said Peter Tiller, senior group product manager, Murata Electronics North America. “Too often we hear of consumers losing a phone or camera due to accidental submersion in water. We hope our new speaker will allow more mobile consumer products to be waterproof and survive life's little accidents." Sample pricing of Murata's waterproof piezoelectric speaker is approximately $2.90 in small quantities and the lead-time is 11 weeks. Further information can be found on-line at http://www.murata-northamerica.com
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Le n s - http://www.optoiq.com/index/machine-vision-imaging-processing/display/vsd-article-display/articles/optoiq2/machinevision___image/technologies-__products/optics-__lenses_/2010/7/Tunable_Optics.html Disparate technologies are being employed in the development of miniaturized autofocus lenses Andrew Wilson, Editor - Jul 1, 2010
Many of the optical systems used in machine-vision and image-processing systems are based on glass or plastic lenses. While some of these systems employ fixed-focal-length lenses, others require lenses where the focal length must be changed. In traditional mechanically based lens systems, this is accomplished by translating the optical elements within the lens against each other. As the predominant method of focusing images for over a century, mechanical lens motion sharply contradicts the biological methods found in nature. By leveraging principles based on these methods, manufacturers are now developing different types of small deformable lenses that can be tuned over various focal distances. Because these lens systems can be miniaturized relatively easily, they are finding applications in smart machine-vision cameras, endoscopy systems, and cell phones.
Electrowetting technology First demonstrated more than five years ago by both Philips Research and Varioptic, liquid lenses that use electrowetting technology perform autofocusing by employing a lens comprising two immiscible fluids of different refractive indexes. In both the Philips and Varioptic designs, these consist of an electrically conducting water solution and electrically nonconducting oil (see figure below). The interface between these liquids then forms a natural diopter, due to the index difference of the two liquids.
By employing an electrically conducting water solution and electrically nonconducting oil, an interface that forms a natural diopter is created due to the index difference of the two liquids. To control the shape of the lens, an electric field is applied across the hydrophobic coating and the aqueous solution wets the sidewalls of the tube, altering the radius of curvature of the meniscus between the two fluids and thus the lens' focal length. To control the shape of the lens, an electric field is applied across the hydrophobic coating so that it becomes less hydrophobicâ€”a process called electrowetting that results from an electrically induced change in surface tension. As a result, the aqueous solution begins to wet the sidewalls of the tube, altering the radius of curvature of the meniscus between the two fluids and thus the lens' focal length. By increasing the electric field, the surface of the initially convex lens can be made completely flat or even concave. As a result it is possible to implement lenses that transition smoothly from being convergent to divergent and vice versa.
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Transparent & Flexible Electronics Liquid crystals Liquid crystals are also being employed in other types of electro-optical adaptive lens designs to perform autofocusing. In the technique used by LensVector, for example, a control voltage is applied to dynamically change the rotation of molecules in a liquid-crystal cell to achieve a change in refractive index. In applying this voltage, the differential rotation of the liquid-crystal molecules from the center to the periphery of the element is changed, focusing light at the desired focal distance (see figure below). By tuning this voltage, the differential rotation of molecules in the element results in a lens that can be focused from infinity to 10 cm.
Liquid crystals are also being employed in other types of electro-optical adaptive lens designs to perform autofocusing. Here, a control voltage is applied to dynamically change the rotation of molecules in a liquidcrystal cell to achieve a change in refractive index. By tuning this voltage, the differential rotation of molecules in the element results in a lens that can be focused from infinity to 10 cm. While such autofocus lenses have for a number of years been the subject of much research, they are now being deployed by companies developing smart cameras for machine vision. Indeed, autofocus lenses based on Varioptic's electrowetting technology have already been employed in both the DataMan 100 and 200 series of image-based ID readers from Cognex and the QX Hawk barcode imager from Microscan. In future, it appears that, whichever technology is adopted, such self-adaptive lenses will be used in other applications, most notably cell phones and endoscopy systems where miniaturization is an important design consideration.
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Transparent & Flexible Electronics - http://www.varioptic.com/en/tech/technology01.php Liquid lens for Autofocus The liquid lenses that we develop are based on the electrowetting phenomenon described below : a water drop is deposited on a substrate made of metal, covered by a thin insulating layer. The voltage applied to the substrate modifies the contact angle of the liquid drop. The liquid lens uses two isodensity liquids, one is an insulator while the other is a conductor. The variation of voltage leads to a change of curvature of the liquidliquid interface, which in turn leads to a change of the focal length of the lens.
□□□□□ - http://www.opticsinfobase.org/abstract.cfm?uri=oe-16-11-8084 Liquid micro-lens array activated by selective electrowetting on lithium niobate substrates S. Grilli, L. Miccio, V. Vespini, A. Finizio, S. De Nicola, and Pietro Ferraro Optics Express, Vol. 16, Issue 11, pp. 8084-8093 (2008) doi:10.1364/OE.16.008084
Lens effect was obtained in an open microfluidic system by using a thin layer of liquid on a polar electric crystal like LiNbO3. An array of liquid micro-lenses was generated by electrowetting effect in pyroelectric periodically poled crystals. Compared to conventional electrowetting devices, the pyroelectric effect allowed to have an electrode-less and circuit-less configuration. An interferometric technique was used to characterize the curvature of the micro-lenses and the corresponding results are presented and discussed. The preliminary results concerning the imaging capability of the micro-lens array are also reported.
2nd article - http://www.opticsinfobase.org/abstract.cfm?uri=OPN-19-12-34
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Transparent & Flexible Electronics - http://www.spectrum.ieee.org/dec04/4172 Through a Lens Sharply FluidFocus lens, uses electrostatic forces to alter the shape of a drop of slightly salty water inside a glass cylinder 3 millimeters in diameter and 2.2 mm long. By Benno Hendriks and Stein ÂŠ Copyright 2009 IEEE
Illustration: Bryan Christie
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Bio-Sensors - http://www.upenn.edu/pennnews/news/penn-researchers-provide-first-step-towards-electronic-dnasequencing-translocation-through-gra Researchers at the University of Pennsylvania have developed a new, carbon-based nanoscale platform to electrically detect single DNA molecules. Jordan Reese July 2010
Using electric fields, the tiny DNA strands are pushed through nanoscale-sized, atomically thin pores in a graphene nanopore platform that ultimately may be important for fast electronic sequencing of the four chemical bases of DNA based on their unique electrical signature. The pores, burned into graphene membranes using electron beam technology, provide Penn physicists with electronic measurements of the translocation of DNA. Graphene nanopore devices developed by the Penn team work in a simple manner. The pore divides two chambers of electrolyte solution and researchers apply voltage, which drives ions through the pores. Ion transport is measured as a current flowing from the voltage source. DNA molecules, inserted into the electrolyte, can be driven single file through such nanopores. As the molecules translocate, they block the flow of ions and are detected as a drop in the measured current. Because the four DNA bases block the current differently, graphene nanopores with sub-nanometer thickness may provide a way to distinguish among bases, realizing a low-cost, high-throughput DNA sequencing technique. In addition, to increase the robustness of graphene nanopore devices, Penn researchers also deposited an ultrathin layer, only a few atomic layers thick, of titanium oxide on the membrane which further generated a cleaner, more easily wettable surface that allows the DNA to go through it more easily. Although grapheneonly nanopores can be used for translocating DNA, coating the graphene membranes with a layer of oxide consistently reduced the nanopore noise level and at the same time improved the robustness of the device. Because of the ultrathin nature of the graphene pores, researchers were able to detect an increase in the magnitude of the translocation signals relative to previous solid state nanopores made in silicon nitride, for similar applied voltages. Research was conducted by Merchant, Healy, Wanunu, Ray, Neil Peterman, John Bartel, Michael D. Fischbein, Kimberly Venta, Luo, Johnson and DrndiĂŚ of Penn's Department of Physics and Astronomy. The research was supported by a National Institutes of Health grant and also grants from the U.S. Department of Defense, Army Research Office, Penn Genome Frontiers Institute, Nano-Bio Interface Center at Penn, Nanotechnology Institute of the Commonwealth of Pennsylvania and Pennsylvania Department of Health. The Department of Health specifically disclaims responsibility for any analyses, interpretations or conclusions.
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Transparent & Flexible Electronics - http://www.physics.upenn.edu/~drndic/group/graphene-nanopore.html
Graphene nanopore devices. (a) Device schematic. Few-layer graphene (1-5 nm thick) is suspended over a 1 ĂŹm hole in a 40 nm thick silicon nitride (SiN) membrane. The SiN membrane is suspended over an approx. 50 x 50 ĂŹm2 aperture in a silicon chip coated with a 5 ĂŹm SiO2 layer. The device is inserted into a PDMS measurement cell with microfluidic channels that form reservoirs in contact with either side of the chip. A bias voltage, VB, is applied between the reservoirs to drive DNA through the nanopore. (b) TEM image of a nanopore in a graphene membrane. Scale bar is 10 nm. (c) Ionic current-voltage measurement for this 10-nm graphene nanopore device in 1M KCl, pH 9.
- http://www.nanowerk.com/spotlight/spotid=4056.php Biosensing mechanism with carbon nanotubes explained Transistors are the key elements of many types of electronic (bio)sensors. Since the discovery that individual carbon nanotubes (CNTs) can be used as nanoscale transistors, researchers have recognized their outstanding potential for electronic detection of biomolecules in solution, possibly down to single-molecule sensitivity. To detect biologically derived electronic signals, CNTs are often - but not always - functionalized with (conductive) linkers such as proteins and peptides to interface with soluble biologically relevant targets (linkers need not be conductive as long as they are capable of localizing the target molecule in close vicinity of the tube). Although CNT transistors have been used as biosensors for some years now, the ultimate singlemolecule sensitivity, which is theoretically possible, has not been reached yet. One of the reasons that hampers the full exploitation of these promising nanosensors is that the sensing mechanism is still not well understood. Although a variety of different sensing mechanisms has been suggested previously, various studies contradict one another, and the sensing mechanism remained under debate. Researchers in The Netherlands - through modeling and specific control experiments - now have succeeded in identifying the sensing mechanism. They found that the majority of their experiments can be explained by a combination of electrostatic gating and Schottky barrier effects. Because these two mechanisms have different gate-potential dependence, the choice of gate potential can strongly affect the outcome of real-time biosensing experiments.
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Transparent & Flexible Electronics - http://en.wikipedia.org/wiki/Schottky_barrier Schottky barrier A Schottky barrier, named after Walter H. Schottky, is a potential barrier formed at a metal—semiconductor junction which has rectifying characteristics, suitable for use as a diode. The largest differences between a Schottky barrier and a p—n junction are its typically lower junction voltage, and decreased (almost nonexistent) depletion width in the metal. Not all metal—semiconductor junctions form Schottky barriers. A metal—semiconductor junction that does not rectify current is called an ohmic contact. Rectifying properties depend on the metal's work function, the band gap of the intrinsic semiconductor, the type and concentration of dopants in the semiconductor, and other factors. Design of semiconductor devices requires familiarity with the Schottky effect to ensure Schottky barriers are not created accidentally where an ohmic connection is desired. - http://www.nanowerk.com/spotlight/spotid=2749.php Reliably detecting foodborne pathogens with nanotechnology and encoding/decoding techniques. "With embedded forward error-correction function in biosensors, with the result that our multi-array biosensor not only can detect multiple pathogens simultaneously, but also could correct for errors induced by artifacts in biosensors and environment, thus increasing the accuracy and reliability of biosensors" Shantanu Chakrabartty explains to Nanowerk. "In our recent work we have demonstrated that we can successfully construct basic logic circuits (AND and OR) using computational primitives inherent in antigen-antibody interaction. The operation of these logic gates relies on selective conjugation of polyaniline (PANI) nanowires with an antigen-antibody complex. We have also developed corresponding electrical models for these logic gates which can be now be used in computer-aided design of biosensors. \d;0";3.0";Visualization of the final multii-array biosensor prototype (Reprinted with permission from IOP Publishing) Chakrabartty, an Assistant Professor and Director of the Adaptive Integrated Microsystems Laboratory at Michigan State University, led the work that has been reported in a recent paper in Nanotechnology ("Fundamental building blocks for molecular biowire based forward error-correcting biosensors") where he, together with first author Yang Liu and Associate Professor Evangelyn C. Alocilja describes the fabrication, characterization and modeling of fundamental logic gates that can be used for designing biosensors with FEC. By Michael Berger, Copyright 2008 Nanowerk LLC
- http://www.nano.org.uk/news/may2008/latest1395.htm NASA Nano-Biosensor Helps Detect Biohazards NASA has developed a revolutionary nanotechnology-based biosensor that can detect trace amounts of specific bacteria, viruses and parasites. This biosensor will be used to help prevent the spread of potentially deadly biohazards in water, food and other contaminated sources.
This NASA developed nanotechnology-based biosensor, designed to detect trace amounts of specific bacteria, viruses and parasites, has now been tested and licensed for commercialization by biosensor technology company Early Warning Inc., from Troy , N.Y. 23rd May 2008 NASA - ©2008 Institute of Nanotechnology
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Virtual Muscles almost invisible muscles to animate new elecronic devices - http://www.unwiredview.com/2008/01/25/foldable-rollable-phone-from-motorola/ By Staska on 25 Jan 08
Foldable/ rollable phone from Motorola The design of the mobile phones is always a fight between two opposite objectives - portability and usability. The more small and portable the device becomes, the less usable the user interface can be. You can make the phone screen only that small, until the information displayed on it becomes unreadable. The same goes for the input devices. Make the keyboard small enough, and the user will have a really hard time pressing the correct keys. Well. Motorola has an interesting idea what to do about that. In a patent application “User Interface System” it describes a concept of mobile phone with rollable display and/or keyboard.
Of course, the idea of flexible/rollable screens and keyboards is nothing new. The are quite a few of these gadgets on the market or at least in late prototype stage. The problem with these devices is that flexible/rollable is by definition not rigid. And using the phone with a keypad or display flapping in the wind, is not such a good idea. But Motorola has found the way around this little problem, by using a reservoir with electrorheological fluid beneath the foldable display or keypad. This fluid becomes a solid material when electric current is applied to it, and then reverts again to fluid state when the electric current disappears. The phone with either rollable display or keypad will have all it’s working electronics in a solid part, with an enclosure for the flexible part located here as well. In inactive state the flexible part rests in an enclosure. Whenever the call comes in, or you want to make one, press a button. Electric current is applied, the display rolls out and springs into a solid state, and you use the device as any other mobile phone. Press the button again, and display folds back-in. To take it even further, both display and keypad can be made flexible. You just put all the necessary electronics into a solid container, with the enclosures for flexible display and keypad. This way you could make matchbox sized mobile mobile phone, which will be as easy to use as any other clamshell. Looks like an interesting, if pretty far fetched idea, which probably won’t come to life anytime soon.
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Transparent & Flexible Electronics - http://www.newscientist.com/blog/invention/2006/06/origami-gadgets.html June 06, 2006
Sony patents fold-up origami gadgetry At Sony Tokyo labs are working on a clever way to get bulky electronic devices into small pockets. Their plan is to create handheld computers, phones and portable games consoles that fold up for carrying and then become rigid for use. The body and screen of folding gadgets would be made from a flexible polymer containing conductive rubber bracing struts filled with a gel of aluminosilicate particles suspended in silicone oil.
When a current is passed through the struts, the particles clump together and harden the gel, making the gadget solid enough to use. Sony has found that it would take very little power to make such a folding device harden, so the drain on its battery should be low. The company's patent adds that the transition from soft to hard takes just milliseconds. It suggests that the same technique could even be used in a video game controller to make it jolt or change shape in response to on-screen action.
Electrorheological (ER) fluids -
Electrorheological (ER) fluids are suspensions of extremely fine non-conducting particles (up to 50 micrometres diameter) in an electrically insulating fluid. The apparent viscosity of these fluids changes reversibly by an order of up to 100,000 in response to an electric field. For example, a typical ER fluid can go from the consistency of a liquid to that of a gel, and back, with response times on the order of milliseconds. The effect is sometimes called the Winslow effect, after its discoverer the American inventor Willis Winslow, who obtained a US patent on the effect in 1947 and wrote an article published in 1949 Applications The normal application of ER fluids is in fast acting hydraulic valves and clutches, with the separation between plates being in the order of 1 mm and the applied potential being in the order of 1 kV. In simple terms, when the electric field is applied, an ER hydraulic valve is shut or the plates of an ER clutch are locked together, when the electric field is removed the ER hydraulic valve is open or the clutch plates are disengaged. Other common applications are in ER brakes (think of a brake as a clutch with one side fixed) and shock absorbers (which can be thought of as closed hydraulic systems consisting of a valve with no external pump). There are many novel uses for these fluids, including use in the US army's planned future force warrior project. They plan to create bulletproof vests using an ER fluid because the ability to soak the fluid into cloth creates the potential for a very light vest that can change from a normal cloth into a hard covering almost instantaneously. Other potential uses are in accurate abrasive polishing and as haptic controllers and tactile displays. 102 Massimo Marrazzo - biodomotica.com
Transparent & Flexible Electronics ER fluid has also been proposed to have potential applications in flexible electronics, with the fluid incorporated in elements such as rollable screens and keypads, in which the viscosity-changing qualities of the fluid allowing the rollable elements to become rigid for use, and flexible to roll and retract for storing when not in use. Motorola filed a patent application for mobile device applications in 2006 The change in apparent viscosity is dependent on the applied electric field, i.e. the potential divided by the distance between the plates. The change is not a simple change in viscosity, hence these fluids are now known as ER fluids, rather than by the older term Electro Viscous fluids. The effect is better described as an electric field dependent shear yield stress. When activated an ER fluid behaves as a Bingham plastic (a type of viscoelastic material), with a yield point which is determined by the electric field strength. After the yield point is reached, the fluid shears as a fluid, i.e. the incremental shear stress is proportional to the rate of shear (in a Newtonian fluid there is no yield point and stress is directly proportional to shear). Hence the resistance to motion of the fluid can be controlled by adjusting the applied electric field.
- http://web.phys.ust.hk/index.php?option=com_content&task=view&id=88&Itemid=79 Electrorheological (ER) fluids denote a class of materials consisting of nanometer to micrometer sized solid particles dispersed in a liquid, whose rheological (i.e., deformation and flow) properties are controllable by an external electric field. In particular, they can reversibly transform from a liquid to a solid within one hundredth of a second. While in the solid state (with the electric field applied), the strength of that solid, measured by the yield stress, is the critical parameter that governs the application potential of the ER fluid.
Composition of ER fluids
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Transparent & Flexible Electronics At HKUST, eight years of research work on ER fluids led to a breakthrough last year in the synthesis of a novel type of ER fluid that consists of 70-nanometer-sized coated nanoparticles dispersed in insulating oil. These new fluids, which harness the extremely high electric field that exists in Debye double layers, exhibit yield stress one order of magnitude higher than the best commercially available ER particles. The significance of this breakthrough is that the yield stress has broken the theoretical upper bound predicted on the basis of linear response of the component materials, thereby signifying a new mechanism. This new class of ER fluids is thus denoted as having a 'Giant Electrorheological' (GER) Effect, surpassing the threshold that the General Motors study has set for automotive applications. It is envisioned that HKUST's GER fluids can be used not only in those classical applications, but also in micro-electromechanical systems (MEMS) or nano-EMS as replacements for microgears, reducing cost and increasing reliability and simplicity of controlled mechanical motion in the micro- to nanoscale. After its publication in Nature Materials, this new breakthrough has been reported around the world in the Washington Post, Science News, New Scientist, NanoToday, Nanotech, Technology Review News (TRN), and thirty other media outlets.
Magnetorheological fluid - http://en.wikipedia.org/wiki/Magnetorheological_fluid A magnetorheological fluid (MR fluid) is a type of smart fluid. It is a suspension of micrometer-sized magnetic particles in a carrier fluid, usually a type of oil. When subjected to a magnetic field, the fluid greatly increases its apparent viscosity, to the point of becoming a viscoelastic solid. Importantly, the yield stress of the fluid when in its active ("on") state can be controlled very accurately by varying the magnetic field intensity. How it works The magnetic particles, which are typically micrometer or nanometer scale spheres or ellipsoids, are suspended within the carrier oil are distributed randomly and in suspension under normal circumstances, as below.
When a magnetic field is applied, however, the microscopic particles (usually in the 0.1-10 µm range) align themselves along the lines of magnetic flux, see below. When the fluid is contained between two poles (typically of separation 0.5-2 mm in the majority of devices), the resulting chains of particles restrict the movement of the fluid, perpendicular to the direction of flux, effectively increasing its viscosity. Importantly, mechanical properties of the fluid in its _on" state are anisotropic. Thus in designing a magnetorheological (or MR) device, it is crucial to ensure that the lines of flux are perpendicular to the direction of the motion to be restricted.
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Transparent & Flexible Electronics - http://science.howstuffworks.com/smart-structure1.htm What is MR Fluid Looking at it in a beaker, MR fluid doesn't seem like such a revolutionary substance. It's a gray, oily liquid that's about three times denser than water. It's not too exciting at first glance, but MR fluid is actually quite amazing to watch in action. A simple demonstration by David Carlson, a physicist at the North Carolina lab, shows the liquid's ability to transform to solid in milliseconds. He pours the liquid into the cup and stirs it around with a pencil to show it's liquid. He then places a magnet to the bottom of the cup, and the liquid instantly turns to a near-solid. To further demonstrate that it's turned to a solid, he holds the cup upside down, and none of the MR fluid drops out.
by David Carlson, a physicist at the North Carolina lab
Above, MR fluid prior to magnetization. Below, the fluid turned into a solid after it was magnetized. Notice the shiny surface of the liquid in the top photo and the dull surface in the bottom photo.
by David Carlson, a physicist at the North Carolina lab
Typical MR fluid consists of these three parts: 路 Carbonyl Iron Particles -- 20 to 40 percent of the fluid is made of these soft iron particles that are just 3 to 5 micrometers in diameter. A package of dry carbonyl iron particles looks like black flour because the particles are so fine. 路 A Carrier Liquid -- The iron particles are suspended in a liquid, usually hydrocarbon oil. Water is often used in demonstrating the fluid. 路 Proprietary Additives -- The third component of MR fluid is a secret, but Lord says these additives are put in to inhibit gravitational settling of the iron particles, promote particle suspension, enhance lubricity, modify viscosity and inhibit wear. So, what is it that gives MR fluid its unique ability to transform from liquid to solid and from solid to liquid quicker than you can blink an eye? The carbonyl iron particles. When a magnet is applied to the liquid, these tiny particles line up to make the fluid stiffen into a solid. This is caused by the dc magnetic field, making the particles lock into a uniform polarity. How hard the substance becomes depends on the strength of the magnetic field. Take away the magnet, and the particles unlock immediately. 漏 1998-2008 HowStuffWorks, Inc.
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Geck o (new adhesive) - http://www.nanowerk.com/spotlight/spotid=3180.php For super-strong nanotechnology dry adhesives look no further than the gecko Animals that cling to walls and walk on ceilings owe this ability to micro- and nanoscale attachment elements. The highest adhesion forces are encountered in geckos. For centuries, the ability of geckos to climb any vertical surface or hang from ceilings with one toe has always generated considerable interest. A gecko is the heaviest animal that can 'stand' on a ceiling, with its feet over its head. This is why scientists are intensely researching the adhesive system of the tiny hairs on its feet. On the sole of a gecko's toes there are some one billion tiny adhesive hairs called setae (3-130 micrometers in length), splitting into even smaller spatulae (about 200 nanometers in both width and length) at the end. It was found that these elastic hairs induce strong van der Waals forces. This finding has prompted many researchers to use synthetic microarrays to mimic gecko feet. Recentwork, mainly from A. Dhinojwala, P.M. Ajayan, M. Meyyappan, and L. Dai groups, as well as the Max Planck Institute for Metals Research in Germany has indicated that aligned carbon nanotubes (CNTs) sticking out of substrate surfaces showed strong nanometer-scale adhesion forces. Although carbon nanotubes are thousands of times thinner than a human hair, they can be stronger than steel, lighter than plastic, more conductive than copper for electricity and diamond for heat. Applications of such bio-inspired development of artificial dry adhesive systems with aligned carbon nanotubes could range from low-tech fridge magnets to holding together electronics or even airplane parts.
a) photo showing a stainless steel adapter of 473 g hanging on a SiO2/Si-wafer supported vertically aligned SWCNT dry adhesive film (4mm x 4mm) b) pre-pressed (2 kg) from the Si side onto a horizontally-placed glass surface c) a comparison of the maximum achievable adhesion forces for: (i) microfabricated polymer hairs (ii) vertically aligned MWCNT (iii) the as-grown aligned vertically aligned SWCNT. The dashed line represents the adhesion force for gecko feet d) a side-top view SEM image of the vertically aligned SWCNT film under a high magnification. Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission. - http://dx.doi.org/doi:10.1002/adma.200700023 By Michael Berger, Copyright 2008 Nanowerk LLC
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Transparent & Flexible Electronics - http://nanolab.me.cmu.edu/projects/geckohair/ Nature can be an inspiration for innovations in science. One such inspiration is comes from the gecko lizard which can climb on walls and ceilings of almost any surface texture. Rather than using it's claws or sticky substances, the gecko is able to stick to smooth surfaces through dry adhesion which requires no energy to hold it to the surface and leaves no residue. The dry adhesion force comes from surface contact forces such as van der Waals forces which act between all materials in contact. Copyright © 2008 Mike Murphy & Yigit Menguc.
http://www.lclark.edu/~autumn/dept/geckostory.html How Geckos Stick to Walls
Nature v. 405: 681-685. - http://polypedal.berkeley.edu/twiki/pub/PolyPEDAL/PolypedalPublications/57_adhesive_force.pdf Nature — from http://www.lclark.edu/~autumn/private/u38j47a0t/
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Transparent & Flexible Electronics - http://www.nsf.gov/discoveries/disc_summ.jsp?org=OIG&cntn_id=116297&preview=false Researchers move one step closer to nature with the development of polymers and directional adhesion that follow the workings of a gecko's foot. February 9, 2010
Video on Stickybot - http://www.nsf.gov/discoveries/disc_videos.jsp?org=OIG&cntn_id=116297&media_id=66263 Stickybot employs the same principles as a gecko through the use of dry adhesion to climb walls. Credit: Mark R. Cutkosky, Stanford University and Sangbae Kim, MIT
- http://www.nsf.gov/news/news_summ.jsp?org=NSF&cntn_id=112445&preview=false As Sticky as a Gecko ... but Ten Times Stronger! By Zina Deretsky, NSF October 14, 2008
The secret behind the gecko's ability to stick so well is a forest of pillars at the micro-/nano-scale on the underside of the gecko's foot. Because there are so many pillars so close together, they are held tightly to the surface the gecko is walking on by a molecular force called the Van der Waals force. This relatively weak force causes uncharged molecules to attract each other. In an unprecedented feat, Liming Dai, at the University of Dayton, and colleagues report in the October 10th issue of Science successful construction of a gecko-inspired adhesive that is ten times stronger than a gecko, at about 100 newtons per square centimeter. The researchers constructed their adhesive out of two slightly different layers of multi-walled carbon nanotubes. The lower layer is composed of vertically-aligned carbon nanotubes, while the upper segment-which comes into contact with the surface it is sticking to--is curly, like a mess of spaghetti. As shown in the figure, the adhesive sticks best when it is pulled down parallel to the surface it is sticking to-this is called shear adhesion. This action arranges the tips of the curly nanotubes so they have maximum contact with the substrate, thereby maximizing the Van der Waals force. Pulling the adhesive off in a motion perpendicular to the substrate is much easier--at this angle the sticking force is ten times weaker. In this way, the adhesive has strong shear adhesion for firm attachment and relatively weak adhesion for detachment perpendicularly to the substrate. Just like a gecko, the adhesive can stick to a wall when needed, and then lift off easily to take the next step. This breakthrough, supported by the National Science Foundation, will have many technological applications.
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- http://www.nsf.gov/news/news_images.jsp?cntn_id=112445&org=NSF Researchers have created a gecko-inspired adhesive with ten times the stickiness of a gecko's foot, by combining vertically aligned nanotubes with curly spaghetti-like nanotubes. Credit: Zina Deretsky, National Science Foundation after Liangti Qu et al., Science 10/10/2008
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Eecs.berkeley research - http://robotics.eecs.berkeley.edu/%7Eronf/Gecko/index.html Biologically Inspired Synthetic Gecko Adhesives Langmuir, Oct 2009
Combined Lamellar Nanofibrillar Array Lamellar structures act as base support planes for high-aspect ratio HDPE fiber arrays. Nanofiber arrays on lamella can adhere to a smooth grating with 5 times greater shear strength than flat nanofiber array
□□□□□ Gecko Tire for Model Car (Nov. 2008) Microfiber array wrapped on model car tire demonstates high friction. (Note: so far, tire only works on smooth surfaces.) - High friction from a stiff polymer using micro-fiber arrays, Phys. Rev. Letters, 2006
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□□□□□ Directional Adhesion of Angled Microfibers (Nov. 2008) Angled polypropylene microfibers show strong directional adhesion effects, with shear strength in direction of fibers 45 times larger than sliding against fiber directions. A 1 sq. cm. patch supported a load of 450 grams in shear. - Directional adhesion of gecko inspired angled microfiber arrays, Applied Physics Letters, 2008.
□□□□□ Self Cleaning Gecko Adhesive (Sep. 2008) First synthetic gecko adhesive which cleans itself during use, as the natural gecko does. After contamination by microspheres, the microfiber array loses all adhesion strength. After repeated contacts with clean glass, the microspheres are shed, and the fibers recover 30% of their original adhesion. The fibers have a non-adhesive default state, which encourages particle removal during contact. - Contact Self-Cleaning of Synthetic Gecko Adhesive, Langmuir 2008
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□□□□□ - http://robotics.eecs.berkeley.edu/~ronf/Gecko/gecko-facts.html Gecko Adhesion Frequently Asked Questions
- http://robotics.eecs.berkeley.edu/~ronf/Gecko/gecko-compare.html Comparison of Fibrillar Adhesives (to glass)
- http://robotics.eecs.berkeley.edu/~ronf/Gecko/prl-friction.html High Friction from a Stiff Polymer using Micro-Fiber Arrays
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Me m s - http://www.memsnet.org/mems/what_is.html Micro-Electro-Mechanical Systems, or MEMS, is a technology that in its most general form can be defined as miniaturized mechanical and electro-mechanical elements (i.e., devices and structures) that are made using the techniques of microfabrication. The critical physical dimensions of MEMS devices can vary from well below one micron on the lower end of the dimensional spectrum, all the way to several millimeters. Likewise, the types of MEMS devices can vary from relatively simple structures having no moving elements, to extremely complex electromechanical systems with multiple moving elements under the control of integrated microelectronics. The one main criterion of MEMS is that there are at least some elements having some sort of mechanical functionality whether or not these elements can move. The term used to define MEMS varies in different parts of the world. In the United States they are predominantly called MEMS, while in some other parts of the world they are called “Microsystems Technology” or “micromachined devices”. While the functional elements of MEMS are miniaturized structures, sensors, actuators, and microelectronics, the most notable (and perhaps most interesting) elements are the microsensors and microactuators. Microsensors and microactuators are appropriately categorized as “transducers”, which are defined as devices that convert energy from one form to another. In the case of microsensors, the device typically converts a measured mechanical signal into an electrical signal.
A surface micromachined electro-statically-actuated micromotor fabricated by the MNX. This device is an example of a MEMS-based microactuator.
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A surface micromachined resonator fabricated by the MNX. This device can be used as both a microsensor as well as a microactuator.
- http://www.memx.com/ This site is dedicated to providing educational material on this fascinating new technology.
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http://community.safenano.org/blogs/andrew_maynard/archive/2008/05/21/carbon-nanotubes-the-newasbestos-not-if-we-act-fast.aspx Carbon nanotubes: the new asbestos? Not if we act fast. Carbon nanotubes have great potential as a unique material that can be used in many unique and beneficial ways—from reducing our environmental impact to curing diseases. But mis-steps now could easily undermine trust in this nascent industry, and prevent the material's potential from being realized. © 2009 Andrew Maynard - http://community.safenano.org/
- http://en.wikipedia.org/wiki/Wi-Fi Wi-Fi Pollution Standardization is a process driven by market forces. Interoperability issues between non-Wi-Fi brands or proprietary deviations from the standard can still disrupt connections or lower throughput speeds on all user's devices that are within range, to include the non-Wi-Fi or proprietary product. Moreover, the usage of the ISM band in the 2.45 GHz range is also common to Bluetooth, WPAN-CSS, ZigBee and any new system will take its share. Wi-Fi pollution, or an excessive number of access points in the area, especially on the same or neighboring channel, can prevent access and interfere with the use of other access points by others, caused by overlapping channels in the 802.11g/b spectrum, as well as with decreased signal-to-noise ratio (SNR) between access points. This can be a problem in high-density areas, such as large apartment complexes or office buildings with many Wi-Fi access points. Additionally, other devices use the 2.4 GHz band: microwave ovens, security cameras, Bluetooth devices and (in some countries) Amateur radio, video senders, cordless phones and baby monitors, all of which can cause significant additional interference. General guidance to those who suffer these forms of interference or network crowding is to migrate to a Wi-Fi 5 GHz product, (802.11a, or the newer 802.11n if it has 5 GHz support) as the 5 GHz band is relatively unused and there are many more channels available. This also requires users to set up the 5 GHz band to be the preferred network in the client and to configure each network band to a different name (SSID). It is also an issue when municipalities, or other large entities such as universities, seek to provide large area coverage. This openness is also important to the success and widespread use of 2.4 GHz Wi-Fi. - http://www.organicui.org/?page_id=70 Sustainability Implications of Organic UI Technologies: An Inky Problem The moment you have decided that sustainability is an issue with respect to interaction design and the design of interactive devices is the moment you realize how complex the business of deciding what to actually do about it is. It is not just a simple matter of calculating the energy and environmental costs of manufacturing, use, salvage, and disposal of one technology over another. For example, it was long ago claimed that computing technologies would create a paperless office—a claim which is not yet in sight. Many people around me print things rather than read on screen. They like to hold paper in their hands and mark things up. Ever since I acquired a portrait mode capable LCD monitor, I have mostly stopped printing things personally. I can now read and write a whole page of text on my 1200×1600 pixel screen at once at 140% of the size it would be if I printed it. As a result, I almost never print anything anymore. The environmental costs of the energy used to power my display must be weighed against the costs of printing the page when I am just reading, assuming that I would actually power-off my display when I am reading what has been printed. Furthermore, the environmental cost of production of the portrait mode display and the environmental costs of the premature obsolescence and disposal of the display I had before this one are also part of the equation. by Eli Blevis © 2008 ACM and/or the authors
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Links to transparent electronics Nanotechnology
http://techon.nikkeibp.co.jp/article/HONSHI/20071024/141211/ http://www.nanowerk.com/spotlight/spotid=1858.php http://www.nanowerk.com/spotlight/spotid=2062.php http://www.nanowerk.com/spotlight/spotid=8787.php http://npl.postech.ac.kr/?mid=Trans_Electronic
Transparent solar cells
http://www.hp.com/hpinfo/newsroom/press/2008/080604a.html http://www.octillioncorp.com/OCTL_20080818.html http://www.octillioncorp.com/nano-power.php
Solar Cell Sheet That Collects Energy at Night
Transparent acoustic transducer
http://nanoarchitecture.net/article/nanotubes-enable-flexible http://dvice.com/archives/2008/04/firstpaper_erea.php http://www.sciencedaily.com/releases/2008/03/080331172507.htm
Samsung Mobile Display's
Flexible see-through battery power
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applications of transparent or flexible electronics LG GD900 transparent keypad mobile - http://www.gadgetlite.com/2009/03/31/pictures-lg-gd900-transparent/ More pictures of LG GD900 transparent keypad mobile ahead of CTIA 2009 March 2009
LG is increasing the buzz on its 13.4mm thick GD900 handset ahead of the upcoming CTIA Wireless Show 2009. The GD900 which you will recall was first shown at the MWC 2009, Barcelona. Its been said that this time, the 7.2 HSPDA slider with world's first transparent glass (not plastic folks!) keypad will be functional, running LG's new S-Class UI on the three inch display. GD900 features a vibrational haptic feedback and the transparent keypad seems to double as a touch-sensitive mouse pad. The GD900 will be available in Europe and Asia in May.
LG-GD900 transparent mobile
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Transparent & Flexible Electronics - http://www.intomobile.com/2009/04/02/lg-gd900-style-up-close-and-personal-with-the-transparent-phone/ LG GD900 Style — Up close and personal with the 'transparent' phone by Will Thursday, April 2nd, 2009
Having a capacitance-based touchscreen and touch-sensitive keypad allows the LG Style to support multitouch features like pinch-to-zoom. But, the touch-interaction isn't just limited to the display — multi-touch gestures are supported on both the touchscreen display and the keypad. The LG GD900 Style allows the user to navigate through the UI using swiping motions on the transparent slide-out keypad. The keypad also goes beyond simple multi-touch with its support for finger-gestures. Simply trace a _W" (or whatever movement you choose to program) on the keypad and the LG Style will launch the web browser. Trace an _M" and you get the music player. It makes sense.
□□□□□ TDK the transparent OLED - http://laptopreviewshop.com/tdk-joins-the-transparent-oled-fight.html TDK joins the transparent OLED fight Mircea / October 4, 2010
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Transparent & Flexible Electronics TDK makes its entrance on the transparent OLED market with 2-inch passive matrix screen with a humble QVGA (320 x 240) resolution. Sure, no eye-popping specs here, but a claimed 50 percent transmittance which means that half of what's behind the screen can be seen through it, knocks out both Samsung and LG.
TDK also presented another 3.5 inch flexible OLED screen which is as thin as 0.3 mm. It's made using a resin substrate and squeezes only 256 x 54 pixels at the moment, but TDK plans to take both technologies step by step into the realm of awesomeness. Be sure to keep your eye on these if you find yourself at CEATEC 2010, and who knows, maybe we'll even hear about a flexible transparent OLED screen soon if these technologies will merge together.
□□□□□ - http://www.crunchgear.com/2010/10/05/ceatec-2010-eyes-on-with-tdks-bendable-and-transparent-oleds-video/ TDK's two passive matrix mini OLED panels by Serkan Toto on October 2010
t this year's CEATEC: TDK's two passive matrix mini OLED panels, one of which is transparent and the other bendable (like the one Sony showed earlier this year). What's cool is that both prototypes are showcased as black-and-white and color models. You can see both displays in action in the videos I took at the exhibition below. The flexible type is just 0.3mm thin and sized at 3.5 inches. Apparently, TDK plans to start mass-producing this panel as early next year. Its picture quality wasn't really as high as you'd want it to be, but there is still time for improvements. The panel with the bigger wow-factor, the see-through type, was really cool. It has a transmittance of about 50% and features QVGA resolution — which is OK, at a screen size of about 2 inches. I want one, but I am not sure why exactly screens (of any size) would have to be transparent.
Video on TDK's displays
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□□□□□ - http://www.engadget.com/2010/10/05/tdks-see-through-and-curved-oled-display-eyes-on/ TDK's see-through and curved OLED display eyes-on By Chris Ziegler posted Oct 5th 2010
Engadget.com - By Chris Ziegler
Remember the Sony Ericsson Xperia Pureness? At a list price of $1,000, it'd be hard to forget -- but with a monochrome see-through display, the whole transparency thing was little more than a novelty on a phone that served little practical purpose. TDK might have the solution with its new transparent QVGA OLEDs, available now to manufacturers in monochrome and in a lovely color variant by the end of the year. At two inches, they offer 200ppi pixel density and are more secure than you might think: the light only shines in one direction, so you actually can't see any data from the back even though you can still see through the display. At a glance, the display's didn't seem as vibrant as the best AMOLEDs on the market, but then again, these are passive matrix -- and you can really tell in our videos after the break where the refresh scans stand out.
□□□□□ - http://www.gizmag.com/tdk-unveils-flexible-oled-display-at-ceatec/16569/ By Rick Martin October 5, 2010
TDK unveils flexible OLED display at CEATEC
□□□□□ - http://www.kenteklaserstore.com/Category.aspx?CategoryID=315 Toward roll-to-roll printed power sources and control electronics Dr. Jukka Hast, Dr. Kimmo Solehmainen and Marja Vilkman, VTT Technical Research Centre of Finland
To pave the way for commercialization of printed electronics and optics applications, two European Unionfunded projects are developing roll-to-roll-based fabrication technologies. In the first project, called FACESS (Flexible Autonomous Cost efficient Energy Source and Storage), roll-to-roll printed organic photovoltaics and energy storage devices are being developed. In the second one, Polaric (Printed, Organic and Large-Area Realisation of Integrated Circuits), the aim is to bring the performance of printed electronics to a new level by combining roll-to-roll compatible high-resolution steps in the transistor fabrication process, and to demonstrate the developed high-performance organic electronics in various consumer applications.
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Transparent & Flexible Electronics Traditionally, the primary function of printing has been the delivery of data and information for visual inspection and further interpretation by humans or machines. Nowadays, printing and other large-area R2R (roll-to-roll)compatible processes enable cost-efficient mass manufacturing of electronics and other functionalities on large-area and flexible substrates such as plastic, paper and fabrics. New printable-functional materials, print-production processes and reading mechanisms are expanding the role and function of printing toward novel application fields. This is the opportunity gap between traditional paper, packaging and printing industry products, and ICT/ electronics industry products, and it can realize completely new types of applications and businesses; e.g., disposable sensors, simple “electronic” components and circuits, large-area functional paperlike intelligent products, smart packages, tag-and-code technology-based ICT and hybrid media services. In the FACESS project, energy harvesting and storage are being tackled. The goal of the project partners – VTT Technical Research Centre and Suntrica Oy, both of Finland; Interuniversity Micro-Electronics Centre of Belgium; Commissariat à l’Energie Atomique of France; Politechnika Warszawska of Poland; Umicore SA of Belgium; and Coatema Coating Machinery GmbH and Coatema Maschinenbau GmbH, both of Germany – is to develop cost-efficient R2R production techniques for organic solar cell modules and rechargeable lithium batteries. Also in development is an application-specific integrated circuit (ASIC) chip that would optimize and control the battery charge from the organic solar modules. To be flexible, the chip is thinned to 30 µm and interconnected on the flexible backplane. The plan is to use R2R-compatible production technologies to manufacture an energy storage foil of four printed organic solar cell modules comprising a 100-cm2 area, a printed battery and an interconnected ASIC to control the charge operation. Under AM1.5, a reference organic solar cell module can produce 250 mW of power to charge the battery. The battery size is approximately 30 cm2 and its capacity, between 1 and 3 mAh/cm2. In Figure, four gravure-printed organic solar cell modules operate at 2.3 percent photon-conversion efficiency 2 at air mass 1.5 illumination on a 15.5-cm area per module. The modules are manufactured using commercially available conductive – and photoactive – polymers. The rechargeable lithium battery has anode and cathode electrodes screen-printed on aluminum and copper foils, and an assembled commercial separator foil. The battery produces ~40-mAh capacity. The 30-µm-thick ASIC is flip-chip-bonded using anisotropically conducting adhesive on the backplane substrate.
This energy storage foil is from the FACESS project
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Transparent & Flexible Electronics All other components of the energy source built for the FACESS project are printed, except for the electronic part. This is because the performance limitations of printed electronic circuits force the use of traditional, silicon-based microchips for the control electronics. To enable wholly printed devices, the printed circuits must be improved significantly. After the FACESS and POLARIC projects, high-performing organic electronic building blocks and manufacturing platforms can be used in all areas of printed electronics, including sensors, memory, batteries, photovoltaics, lighting and any combination of these devices. By combining different functionalities and blocks on the same flexible foil, and integrating the whole process in a cost-efficient way, the huge market potential for printed electronics and optics will turn into reality. Meet the authors Dr. Jukka Hast is a senior research scientist; e-mail: firstname.lastname@example.org. Dr. Kimmo Solehmainen also is a senior research scientist; e-mail: email@example.com. Marja Vilkman is a research scientist; email: firstname.lastname@example.org. All three work at VTT Technical Research Centre of Finland, Printed Functional Solutions.
□□□□□ Flexible Autonomous Cost Efficient Energy Source and Storage = FACESS - http://www.vtt.fi/proj/facess/index.jsp
□□□□□ - http://www.vtt.fi/proj/facess/facess_overview.jsp Flexible Autonomous Cost Efficient Energy Source and Storage Project overview The general objectives of this project are the following: to manufacture efficient organic solar cells (OSC) and a thin film battery (TFB) on flexible substrate using commercially available materials and cost efficient roll-toroll (R2R) mass production techniques, printing, as well as integrate a control transistor circuitry on a foil. The ultimate goal is to integrate these three structures to a single assembly resulting in a flexible, fully autonomous energy source. In this assembly organic solar cells harvest the solar energy and charge the thin film batteries which provide the electricity for an external load. The Si-based transistor circuitry integrated on the foil controls the charge operation.
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Itâ€™s a kind of magic Invisibility Cloak - http://newscenter.lbl.gov/feature-stories/2009/05/01/invisibility-cloak/ Blurring the Line Between Magic and Science: Berkeley Researchers Create an _Invisibility Cloak" May 01, 2009
A team led by Xiang Zhang, a principal investigator with Berkeley Lab's Materials Sciences Division and director of UC Berkeley's Nano-scale Science and Engineering Center, has created a _carpet cloak" from nanostructured silicon that conceals the presence of objects placed under it from optical detection. While the carpet itself can still be seen, the bulge of the object underneath it disappears from view. Shining a beam of light on the bulge shows a reflection identical to that of a beam reflected from a flat surface, meaning the object itself has essentially been rendered invisible. We have come up with a new solution to the problem of invisibility based on the use of dielectric (nonconducting) materials," says Zhang. _Our optical cloak not only suggests that true invisibility materials are within reach, it also represents a major step towards transformation optics, opening the door to manipulating light at will for the creation of powerful new microscopes and faster computers." Zhang and his team have published a paper on this research in the journal Nature Materials entitled: An Optical Cloak Made of Dielectrics. Co-authoring the paper with Zhang were Jason Valentine, Jensen Li, Thomas Zentgraf and Guy Bartal, all members of Zhang's research group.
These three images depict how light striking an object covered with the carpet cloak acts as if there were no object being concealed on the flat surface. In essence, the object has become invisible. (Image by Thomas Zentgraf)
Previous work by Zhang and his group with invisibility devices involved complex metamaterials â€” composites of metals and dielectrics whose extraordinary optical properties arise from their unique structure rather than their composition. They constructed one material out of an elaborate fishnet of alternating layers of silver and magnesium fluoride, and another out of silver nanowires grown inside porous aluminum oxide. With these metallic metamaterials, Zhang and his group demonstrated that light can be bent backwards, a property unprecedented in nature. While metallic metamaterials have been successfully used to achieve invisibility cloaking at microwave frequencies, until now cloaking at optical frequencies, a key step towards achieving actual invisibility, has not been successful because the metal elements absorb too much light.
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Image (a) is a schematic diagram showing the cloaked region (marked with green) which resides below the reflecting bump (carpet) and can conceal any arbitrary object by transforming the shape of the bump back into a virtually flat object. Image (b) was taken with a scanning electron microscope image of the carpet coated bump. Says Zhang, _Even with the advances that have been made in optical metamaterials, scaling sub-wavelength metallic elements and placing them in an arbitrarily designed spatial manner remains a challenge at optical frequencies." The new cloak created by Zhang and his team is made exclusively from dielectric materials, which are often transparent at optical frequencies. The cloak was demonstrated in a rectangular slab of silicon (250 nanometers thick) that serves as an optical waveguide in which light is confined in the vertical dimension but free to propagate in the other two dimensions. A carefully designed pattern of holes — each 110 nanometers in diameter — perforates the silicon, transforming the slab into a metamaterial that forces light to bend like water flowing around a rock. In the experiments reported in Nature Materials, the cloak was used to cover an area that measured about 3.8 microns by 400 nanometers. It demonstrated invisibility at variable angles of light incident. Right now the cloak operates for light between 1,400 and 1,800 nanometers in wavelength, which is the nearinfrared portion of the electromagnetic spectrum, just slightly longer than light that can be seen with the human eye. However, because of its all dielectric composition and design, Zhang says the cloak is relatively easy to fabricate and should be upwardly scalable. He is also optimistic that with more precise fabrication this all dielectric approach to cloaking should yield a material that operates for visible light — in other words, true invisibility to the naked eye. In this experiment, we have demonstrated a proof of concept for optical cloaking that works well in two dimensions" says Zhang. _Our next goal is to realize a cloak for all three dimensions, extending the transformation optics into potential applications." This research was funded in part by the U.S. Department of Energy's Office of Science through its Basic Energy Sciences program and by the U.S. Army Research Office. Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research and is managed by the University of California. Visit website at http://www.lbl.gov. Additional information: A copy of the Nature Materials paper _An Optical Cloak Made of Dielectrics" by Zhang, et al., can be read here: http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat2461.html For more information about the research of Xiang Zhang, visit his Website at http://xlab.me.berkeley.edu/ To learn more about the earlier work by Zhang and his group on invisibility read a UC Berkeley press release at http://www.universityofcalifornia.edu/news/article/18368
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Acronyms See also: Nanotechnology vol.2 Technology for E-books Readers (B/W & colors display) www.biodomotica.com/public/e-paper_e-book.pdf
AFM AMOLED CIGS CMOS CNT DEA DSSC EAP EW EMF ERF ESD ESNAM FFL FEC FET F-OLED GPS GUI IPMC ITO LAN LCD LCM LED LEP LOPE-C MEMS MR MRF MRAM MWNT NEMS OEL OLED Organic UI PANI PH OLED PDA PDMS PEN PET PM-OLED P-OLED PV RFID RRAM R2R STM SWNT TEC TEG TFT TiO2
Atomic Force Microscope Active Matrix Organic light emitting diode Copper Indium Gallium Selenide (semiconductor material) Complementary Metal-Oxide Semiconductor (transistor type) Carbon Nanotube Dielectric Elastomer Actuators Dye sensitized solar cell or Graetzel Cell Electroactive Polymers Electro-wetting Electromotive force Electrorheological fluid Electrostatic discharge European Scientific Network for Artificial Muscles Flat, Flexible Loudspeakers Forward error-correction (biosensors) Field Effect Transistor Flexible Organic light emitting diode Global Position System Graphical User Interface Ionic polymer-metal-composite Indium Tin Oxide Local area networks Liquid Crystal Display Liquid crystal module Light-emitting diode Light emitting polymer Large-area, Organic and Printed Electronics Convention Micro Electronic Mechanical Systems Magneto-Resistive Magnetorheological fluid Magnetoresistive Random Access Memory - A memory fabricated using nanotechnology which uses electron spin to store data. Multi-walled nanotubes Nanoelectromechanical systems Organic Electroluminescent (display technology) Organic Light-Emitting Diode User Interface Polyaniline Phosphorescent Organic Light-Emitting Diode Personal Digital Assistant (electronic handheld information device) Polydimethylsiloxane (organic polymer) Polyethylene Naphthalate (electrical insulation material) Plastic substrates: polyethylene teraphthalate Passive matrix Polymer light emitting diode Photovoltaic Radio Frequency Identification Resistive random access memory Roll-To-Roll (manufacturing) Scanning tunneling microscope Single-walled nanotubes Transparent Electronic Conductive Thermoelectric generators Thin Film Transistor (Liquid Crystal Display, LCD technology) Titanium Dioxide (Photocatalyst coatings) Massimo Marrazzo - biodomotica.com 127
Transparent & Flexible Electronics T-OLED TRRAM TUI WECA Wi-Fi WiMAX
Transparent organic light-emitting device Transparent resistive random access memory Touch User Interface Wireless Ethernet Compatibility Alliance Wireless Fidelity (IEEE 802.11 wireless networking) Worldwide Interoperability for Microwave Access
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B o o ks http://www.foresight.org/nano/Bookstore.html http://www.azonano.com/BookReview.asp?cat=5 http://www.azom.com/bookreview.asp?cat=10 http://www.materialsviews.com/view/0/books.html http://www.worldscibooks.com/nanosci/nanosci.shtml http://www.nanolabweb.com/index.cfm/action/main.default.searchResults/topicID/6/CFID/5216341/CFTOKEN/ 29616759/index.html
Transparent Electronics by Wager, John F., Keszler, Douglas A., Presley, Rick E. About this title: Transparent electronics is an emerging technology that employs wide band-gap semiconductors for the realization of invisible circuits. This monograph provides the first roadmap for transparent electronics, identifying where the field is, where it is going, and what needs to happen to move it forward. Although the central focus of this monograph involves transparent electronics, many of the materials, devices, circuits, and process-integration strategies discussed herein will be of great interest to researchers working in other emerging fields of optoelectronics and electronics involving printing, large areas, low cost, flexibility, wearability, and fashion and design. Computational Physics of Carbon Nanotubes by Hashem Rafii-Tabar About this title: Carbon nanotubes are the fabric of nanotechnology. Investigation into their properties has become one of the most active fields of modern research. This book presents the key computational modeling and numerical simulation tools to investigate carbon nanotube characteristics. In particular, methods applied to geometry and bonding, mechanical, thermal, transport and storage properties are addressed. Nanostructure Design: Methods and Protocols by Ehud Gazit (Editor), Ruth Nussinov (Editor) About this title: As one of the fastest growing fields of research in the 21st century, nanotechnology is sure to have an enormous impact on many aspects of our lives. Nanostructure Design: Methods and Protocols serves as a major reference for theoretical and experimental considerations in the design of biological and bioinspired building blocks, the physical characterization of the formed structures, and the development of their technical applications. Current Topics in Elastomers Research by Bhowmick K Bhowmick, Anil K Bhowmick (Editor) About this title: Written by a world-renowned expert, this concise and pioneering work explores the latest advances in elastomers research. Discussion includes new developments with rubber, nanotechnology, and elastomers; the direction of current research; and the new materials derived using new technologies. Conductive Electroactive Polymers: Intelligent Polymer Systems, Third Edition by Gordon G Wallace, Geoffrey M Spinks, Leon A P Kane-Maguire About this title: An in-depth look at intelligent polymer systems, this third edition features new chapters on the synthesis and fabrication of nanocomponents and nanostructures for polypyrroles, polythiophenes, and polyanilines. Massimo Marrazzo - biodomotica.com 129
Transparent & Flexible Electronics Nanostructures in Electronics and Photonics by Faiz Rahman (Editor) About this title: Nanotechnology is the buzzword these days. This book provides a broad overview of nanotechnology as applied to contemporary electronics and photonics. The areas of application described are typical of what originally set off the nanotechnology revolution. Photonic Ink and Elastic Ink Lab-to-Market by Ozin, Z. Anorg. Allg. Chem., 2008, 634, 1871-2100 P-Ink is made of a metallopolymer opal gel that reversibly swells and shrinks with application and removal of a voltage. Elast-Ink is made of an elastomeric opal that undergoes reversible dimensional changes on applying and removing a mechanical force. Artificial Muscles: Applications of Advanced Polymeric Nanocomposites by Professor Mohsen Shahinpoor, Kwang J Kim, Mehran Mojarrad About this title: Smart materials are the way of the future in a variety of fields, from biomedical engineering and chemistry to nanoscience, nanotechnology, and robotics. Featuring an interdisciplinary approach to smart materials and structures, "Artificial Muscles: Applications of Advanced Polymeric Nanocomposites" thoroughly reviews the existing knowledge of ionic polymeric conductor nanocomposites (IPCNCs), including ionic polymeric metal nanocomposites (IPMNCs) as biomimetic distributed nanosensors, nanoactuators, nanotransducers, nanorobots, artificial muscles, and electrically controllable intelligent polymeric network structures. Challenges in the Management of New Technologies by Marianne Horlesberger (Editor), Mohamed El-Nawawi (Editor), Tarek Khalil (Editor) About this title: New developments in bio- and nanotechnologies and also in information and communication technologies have shaped the research environment in the last decade. Increasingly, highly educated experts in R&D departments are collaborating with scientists and researchers at universities and research institutes to develop new technologies. Commercializing Micro-Nanotechnology Products by David Tolfree (Editor), Mark J Jackson (Editor) About this title: Micro-nanotechnologies are already making a profound impact on our daily lives. New applications are well underway in the US, Asia, and Europe, but their potential disruptive nature, along with public concerns, have produced challenges that must be overcome. Nanotechnology: Health and Environmental Risks (Perspectives in Nanotechnology) by Shatkin, Jo Anne About this title: Nanotechnology promises to be the third wave of technological innovation, but the rapid integration of nanomaterials into consumer products is not without concern. "Nanotechnological Risks" presents various methods for evaluating health, safety, and environmental nanotechnology risks Encyclopedia of Nanoscience and Nanotechnology, Volumes 1-10 by Smalley, Richard About this title: Professor Richard E. Smalley, Nobel Prize Laureate in Chemistry The Encyclopedia of Nanoscience and Nanotechnology is the world's first single most comprehensive reference source ever published in the field of nanotechnology. Nanotechnology: Ethics and Society by Deb Bennett-Woods About this title: Nanotechnology promises to be the next great human technological revolution, but such change often comes at the price of unforeseen consequences. "Navigating the Boundaries" explores several of the practical and ethical dilemmas presented by this technological leap. This book provides a framework for deciding how to best take advantage of nanotechnology opportunities while minimizing potential negative effects
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Transparent & Flexible Electronics Nanotechnology 101 by John Mongillo About this title: What should the average person know about science? Because science is so central to life in the 21st century, science educators and other leaders of the scientific community believe that it is essential that everyone understand the basic concepts of the most vital and far-reaching disciplines. "Nanotechnology 101" does exactly that. Organic Nanostructures by Jerry L Atwood (Editor), Jonathan W Steed (Editor) About this title: Filling the need for a volume on the organic side of nanotechnology, this comprehensive overview covers all major nanostructured materials in one handy volume. Alongside metal organic frameworks, this monograph also treats other modern aspects, such as rotaxanes, catenanes, nanoporosity and catalysis Nanotechnology for Dummies by Richard Booker, Earl Boysen About this title: This title demystifies the topic for investors, business executives, and anyone interested in how molecule-sized machines and processes can transform our lives. Along with dispelling common myths, it covers nanotechnology's origins, how it will affect various industries, and the limitations it can overcome. This handy book also presents numerous applications such as scratch-proof glass, corrosion resistant paints, stainfree clothing, glare-reducing eyeglass coatings, drug delivery systems, medical diagnostic tools, burn and wound dressings, sugar-cube-sized computers, mini-portable power generators, even longer-lasting tennis balls, and more.
The Nanotech Pioneers: Where Are They Taking Us by Steven A Edwards About this title: Hype, hope, or horror? This work is a vivid look at nanotechnology, written by an insider and experienced science writer. The variety of new products and technologies that will spin out of nanoscience is limited only by the imagination of the scientists, engineers and entrepreneurs drawn to this new field. Steve Edwards concentrates on the reader's self interest: no military gadgets, wild fantasies of horror nanobot predators and other sci-fi stuff, but presents a realistic view of how this new field of technology will affect people in the near future.
Molecular Devices and Machines: A Journey Into the Nanoworld by Vincenzo Balzani, Margherita Venturi, Alberto Credi About this title: The miniaturization of bulky devices and machines is a process that confronts us on a daily basis. However, nanoscale machines with varied and novel characteristics may also result from the enlargement of extremely small building blocks, namely individual molecules. This bottom-up approach to nanotechnology is already being pursued in information technology, with many other branches about to follow. Written by a team of experienced authors headed by Vincenzo Balzani, one of the pioneers in the development of molecular machines Covers such diverse aspects as sensors, memory components, solar energy conversion, biomolecules as molecular machines, and much more
Transparent Electronics: From Synthesis to Applications Antonio Facchetti (Editor), Tobin Marks (Editor) ISBN: 978-0-470-99077-3 Hardcover 470 pages April 2010 Structured to strike a balance between introductory and advanced topics, this monograph juxtaposes fundamental science and technology / application issues, and essential materials characteristics versus device architecture and practical applications. The first section is devoted to fundamental materials compositions and their properties, including transparent conducting oxides, transparent oxide semiconductors, p-type wideband-gap semiconductors, and single-wall carbon nanotubes. The second section deals with transparent electronic devices including thin-film transistors, photovoltaic cells, integrated electronic circuits, displays, sensors, solar cells, and electro-optic devices. Massimo Marrazzo - biodomotica.com 131
Transparent & Flexible Electronics Nanotechnology: New Promises, New Dangers by Toby Shelley Zed Books: 2006. 208 pp. Toby Shelley's book Nanotechnology provides a short, accessible primer on the world of nanotechnology â€” the revolutionary realm of seeing, measuring, controlling and making things on the scale of atoms and molecules. It raises key questions about how this disruptive technology will affect human health, the environment, civil liberties, weaponry, and people in developing countries.
Microstrip and Printed Antennas New Trends, Techniques and Applications 1. Edition - November 2010 504 Pages, Hardcover ISBN-10: 0-470-68192-6 ISBN-13: 978-0-470-68192-3 - John Wiley & Sons This book focuses on new techniques, analysis, applications and future trends of microstrip and printed antenna technologies, with particular emphasis to recent advances from the last decade. Attention is given to fundamental concepts and techniques, their practical applications and the future scope of developments. Several topics, essayed as individual chapters include reconfigurable antenna, ultra-wideband (UWB) antenna, reflectarrays, antennas for RFID systems and also those for body area networks. Also included are antennas using metamaterials and defected ground structures (DGSs). This book provides a reference for R&D researchers, professors, practicing engineers, and scientists working in these fields.
Chapters 1-4 Presentation Slides for Science at the Nanoscale: An Introductory Textbook by Chin Wee Shong, Sow Chorng Haur & Andrew T. S. Wee National University of Singapore ISBN: 9789814241038 August 2009 228 pages - http://www.panstanford.com/books/nanosci/v004.html Unbounding the Future: the Nanotechnology Revolution By Eric Drexler and Chris Peterson, with Gayle Pergamit William Morrow and Company, Inc.New York This book delivers a rich array of micro-scenarios of nanotechnology at work, some thrilling, some terrifying, all compelling. Probably none represent exactly what will happen, but in aggregate they give a deep sense of the kind of thing that will happen. Strategies of how to stay ahead of the process are proposed, but the ultimate responsibility for the wholesome use and development of nanotechnology falls on every person aware of it. That now includes you. â€” Stewart Brand http://crnano.org/unbounding.htm Jet-printed Si nanowires for flexible backplane applications W.S. Wong, S. Raychaudhuri, S. Sambandan, R. Lujan, R.A. Street ISBN: 978-1-4398-3402-2 - Pages: 862 The integration of Si nanowire (Si NW) materials with low-temperature plastic substrates can enhance the performance of low-cost flexible electronics. We report the properties of Si NW field-effect transistors (FETs) fabricated with various contact metals and passivation layers. We also demonstrate the use of dielectrophoresis and inkjet printing to pattern and assemble active matrix display backplane arrays of Si NW FETs from a liquid suspension.
Brochure: " Nanotechnology: Innovation for tomorrow's world " Brochure of the European Commission to illustrate to the public what nanotechnology is Brochure is available as pdf in Danish, German, English, Greek, Spanish, French, Italian, Dutch, Polish, Portuguese, Slovenian, Finnish, Swedish, Arab, Chinese, Russian , Czech, Slovak and in Estonian. http://cordis.europa.eu/nanotechnology/src/pe_leaflets_brochures.htm This site is designed to help you find out about European Research. Whether you are a researcher or a teacher, in business or in politics, there is something for you here. You can read about the latest political decisions, or the latest advances in research; there is even a set of online leaflets about European Research in Action, written for the non-specialist and available in 11 or more languages. http://ec.europa.eu/research/index.cfm?lg=en&pg=about 132 Massimo Marrazzo - biodomotica.com
Transparent & Flexible Electronics 7 things every reporter should know before writing about nanotechnology and 7 questions to ask every _nano" company
by Nathan Tinker, PhD, Senior Director The Nanotech Company, with Darrell Brookstein, Managing Director http://www.merlinq.nl/index.php?option=com_content&task=view&id=280&Itemid=74 What are nanoscience and nanotechnologies? http://www.nanotec.org.uk/finalReport.htm
For Italian readers: Quanto è piccolo il mondo. Sorprese e speranze dalle nanotecnologie Pacchioni Gianfranco, 2007, Zanichelli Cosa sono le nanotecnologie. Istruzioni per l'uso della prossima rivoluzione scientifica Narducci Dario,2008, Sironi (collana Galápagos) Brochure: " La Nanotecnologia: Innovazione per il mondo di domani " http://cordis.europa.eu/nanotechnology/src/pe_leaflets_brochures.htm
Journal Papers http://rogers.mse.uiuc.edu/publications.html Journal Papers on Transparent Electronics Disclaimer: The PDF documents on this WebPages are provided for educational and personal purposes alone and are subject to their respective publisher's copyrights.
J. Yoon, A.J. Baca, S.-I. Park, P. Elvikis, J.B. Geddes, L. Li, R.H. Kim, J. Xiao, S. Wang, T.H. Kim, M.J. Motala, B.Y. Ahn, E.B. Duoss, J.A. Lewis, R.G. Nuzzo, P.M. Ferreira, Y. Huang, A. Rockett and J.A. Rogers, _Ultrathin Silicon Solar Microcells for Semitransparent, Mechanically Flexible and Microconcentrator Module Designs," Nature Materials 7, 907-915 (2008). S. Jeon, D.J. Shir, Y.S. Nam, R. Nidetz, M. Highland, D.G. Cahill, J.A. Rogers, M.F. Su, I.F. El-Kady, C.G. Christodoulou and G.R. Bogart, _Molded Transparent Photopolymers and Phase Shift Optics for Fabricating Three Dimensional Nanostructures," Optics Express 15(10), 6358-6366 (2007). Q. Cao, Z.T. Zhu, M.G. Lemaitre, M.G. Xia, M. Shim and J.A. Rogers, "Transparent Flexible Organic Thin-Film Transistors That Use Printed Single-Walled Carbon Nanotube Electrodes," Applied Physics Letters 88, 113511 (2006). http://www.interscience.wiley.com
Wiley InterScience® is a leading international resource for scientific, technical, medical and scholarly content.
http://www3.interscience.wiley.com/journal/10008336/home Advanced Materials
http://www3.interscience.wiley.com/journal/117935002/grouphome Advanced Functional Materials
http://www3.interscience.wiley.com/journal/67500980/home Advanced Engineering Materials
http://www3.interscience.wiley.com/journal/121524295/home Nanomedicine and Nanobiotechnology
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Links http://www.nano.org.uk The Institute of Nanotechnology (IoN) is a registered Charity, whose core activities are focused on education and training in nanotechnology, in the widest sense. The Institute was one of the world's first nanotechnology information providers and is now a global leader.
http://www.crnano.org/whatis.htm The Center for Responsible Nanotechnology (CRN) is a non-profit research and advocacy think tank concerned with the major societal and environmental implications of advanced nanotechnology.
http://www.nanowerk.com Nanowerk is committed to educate, inform and inspire about nanosciences and nanotechnologies.
http://nanotechweb.org/cws/home Nanotechnology journal
http://thefutureofthings.com The Future of Things (TFOT) is an online magazine dedicated to bringing original content on science, technology, and medicine from around the world.
http://www.citala.com/index.php A leader in flexible displays, Citala is the pioneer of the Active Pixel Display (APD_)â€”a flexible reflective display that represents a paradigm shift in the display arena.
http://www.electroscience.com/smartcardappnotes.html Thick-Film Materials and Ceramic Tapes
http://www.cdtltd.co.uk Cambridge Display Technology, a subsidiary of Sumitomo Chemical, leads the development of display technology based on polymer organic light emitting diodes (P-OLEDs).
http://www.vdma.org/wps/portal/Home/en The Organic Electronics Association is a working group within VDMA, representing the whole process chain in organic electronics like e.g. plastic chips, organic displays, sensors and photovoltaics. Our members are international leading companies and institutions and include component and material suppliers, equipment and tool suppliers, producers and system integrators, end-users and research institutes.
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Transparent & Flexible Electronics http://www.nanotechobserver.com/ Nanotech Observer is a multilingual, Web-based, free-content encyclopedia project based mostly on anonymous contributions. Nanotech Observer's articles provide links to guide the user to related pages with additional information.
http://printedelectronics.idtechex.com/printedelectronicsworld/en/ Printed Electronics World provides you with a daily update of the latest industry developments. Launched in May 2007, this free portal covers the progress to printed electronics in all its forms - from transistor circuits to power, sensors, displays, materials and manufacturing.
http://www.sciencedaily.com ScienceDaily is one of the Internet's leading online magazines and Web portals devoted to science, technology, and medicine.
http://www.nanoforum.org/ European Nanotechnology Community Nanoforum has produced Nanotechnology Education Tree which is designed to give an introduction to nanotechnology applications in health, the environment, energy, electronics and modern life
http://www.nanotech-now.com Very much like a White Paper, we seek to provide a forum and format that helps clarify nanotechnology and nanoscale science, to laymen, general business persons, non-specialists, highly skilled technicians, professionals, and academics."
http://www.foresight.org Founded in 1986, we were the first organization to educate society about the benefits and risks of nanotechnology. At that time our focus was on preparing society for nanotechnology, then a little known science and technology.
http://www.zyvex.com We started Zyvex to develop practical uses for molecular nanotechnology to transform how we make physical goods â€” creating clean, flexible, and powerful manufacturing for the 21st century.
http://www.sciencemuseum.org.uk/antenna/nano The Science Museum provides an educational and interactive overview of nanotechnology
http://www.nanotechproject.org/consumerproducts An inventory of nanotechnology-based consumer products currently on the market.
http://www.rmnanotech.com RMNanotech.com contains links to sites where you can purchase Nanotechnology products and Nanotechnology books.
http://www.almaden.ibm.com/st/nanoscale_st/ IBM Research at Almaden participates in a wide variety of activities that fall under the broad scope of nanoscale science and technology. The activities span synthesizing nanoscale materials, nanoscale fabrication for creating nanoscale structures and devices, and developing novel methods to probe and manipulate atoms. http://www.cordis.europa.eu/nanotechnology Nanotechnology Homepage of the European Commission
http://www.nano.gov The National Nanotechnology Initiative (NNI) is the program established in fiscal year 2001 to coordinate Federal nanotechnology research and development.
http://www.futuretechnologycenter.eu The Future Technology Center offers forecasting services on new technologies based on continuous tracking and trend analysis of global technological developments.
http://www.physorg.com/nanotech-news/ Internet news portal provides the latest news on science including: Physics, Space Science, Earth Science, Health and Medicine
http://community.safenano.org/ The UK's premier source of information on nanoparticle hazard, and nanotoxicology
http://www.oled-display.net This site informs about OLED - Organic light emitting diodes
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http://www.nanotech.it Italian http://www.venetonanotech.it Italian http://www.nanotecnologica.com Spanish http://www.nanovip.com video â€” Spanish http://www.nanomicro.recherche.gouv.fr/fr/cnano.html French http://fr.wikipedia.org/wiki/Nanotechnologie French http://www.mannometer-nanometer.de http://nanonet.mext.go.jp
NanotechJapan is the official web site for the Nanotechnology Network Project (2007-2012) funded by the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT). The primary aim of the Project is to provide nanotechnology researchers with access to advanced research facilities of the participating institutions.
National Institute of Advanced Industrial Science and Technology (AIST)
NanoChina.cn provides a bridge between the nanotechnology activities that are taking place in China and the rest of the world, with the aim of disseminating information and setting up nano-business and networking opportunities.
Show/Convention/Exposition Bvents is the largest source of information on conferences, tradeshows, conventions, corporate events and exhibitions worldwide. http://www.bvents.com
B l og s Top 50 Nanotech & Biomaterial Blogs by Miranda on January 12, 2010
http://mastersinhealthinformatics.com/2010/top-50-nanotech-biomaterial-blogs/ 50 Forward Thinking Nanotech Blogs http://becomingacomputertechnician.com/?page_id=98 http://www.gizmag.com http://www.engadget.com http://us.gizmodo.com http://www.crunchgear.com http://www.howtogeek.com Italian Blogs http://www.blogtopsites.com/technology/italian http://chiacchieresulnano.blogspot.com/search/label/nanotecnologie
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T o ol box http://www.nanoword.net Nanoword.net is an online nanotechnology resource focusing on education of the general public and distribution of nanotech products.
http://www.nanoengineer-1.com/mambo Founded in 2004, Nanorex Inc. is a developer of open-source computational modeling tools for the design and analysis of atomically precise nanosystems.
http://www.ides.com/?source=.NetProspector Plastic Properties http://www.plastics-extrusion.co.uk Plastic Properties http://www.dynalabcorp.com/home_defaultpage.asp Plastic Properties http://www.claremicronix.com/
o Products o Display Drivers o E Ink and ePaper
http://www.wikipedia.com Free Online Encyclopedia http://www.howstuffworks.com HowStuffWorks, a wholly owned subsidiary of Discovery Communications, is the award-winning source of credible, unbiased, and easy-to-understand explanations of how the world actually works.
http://www.google.com Internet search engine http://www.thefreedictionary.com/ Free Online Dictionary, Thesaurus, Encyclopedia, Acronyms http://www.patentstorm.us/ PatentStorm offers full-text U.S. patents and patent applications from the U.S. Patent Office, providing advanced search capabilities and full image retrieval in handy PDF format.
http://www.wipo.int/portal/index.html.en Patents and patent applications http://translate.google.com http://world.altavista.com http://www.babylon.com
Online translator Online translator Online / Offline translator
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iPad & iPhone applications for Nanotech iPhone - AzoNano http://www.azonano.com/iphone/ The AZoNanotechnology App from wwww.azonano.com â€” The A to Z of Nanotechnology, represents the world of Nanotechnology in the palm of your hand.
- findNano http://www.nanotechproject.org/news/archive/8295/ findNano allows users to browse an inventory of more than 1,000 nanotechnology-enabled consumer products, from sporting goods to food products and electronics to toys, using the iPhone and iPod Touch. Using the built-in camera, iPhone users can even submit new nanotech products to be included in future inventory updates.
- Nanovip http://www.nanovip.com/free-nanovip-app Nanovip is an online Nanotechnology Portal bringing you the latest nanotech news, jobs and more. Updated in real time
- PhysOrg.con News Lite http://www.physorg.com/help/iphone/
- Technology News This news application will provide you the relevant information of all type of academic and research technologies. Like biotechnology, Information technology, Auto technology, communication, computing, Biometrics, nanotechnology, robotic technology and so on
http://itunes.apple.com/it/app/tiscali/id361736404?mt=8 Italian Apps
iPad - PhysOrg.con News Lite HD http://www.physorg.com/help/ipad/ - Tiscali per iPad
http://itunes.apple.com/it/app/tiscali-per-ipad/id396097628?mt=8 Italian Apps
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Android applications to read RSS Nanotech http://www.talkandroid.com/8805-top-5-android-rss-readers/
gReader gReader is an RSS feed client that allows you to view your feeds by site, or view all at the same time
FeedR FeedR allows you to view you feeds by category. Even better, you can color code your categories so that you can find the news that you want to read fast.
FastReader FastReader is an RSS feed client that gets you your news in a time efficient manner. The app has 2 tabs, one that shows you each feed, and another that lets you view all of the feeds at once.
FeedSquares FeedSquares is not your ordinary RSS reader. In fact, there are no apps like it. Instead of giving you a boring list of your feeds, FeedSquares gives you colorful boxes that represent each feed. If you only have one or two feeds that you get news from, then this app is not for you. But if you have a bunch of news from a bunch of places, then look no further.
NewsRob NewsRob is a very sleek app that gets you your news from your Google Reader account.
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BIODOMOTICA Massimo Marrazzo www.biodomotica.com email@example.com
Disclaimer No one can sell or ask money for this e-book. Every info in this document is available free on Internet, like this e-book. I don’t receive money or any other benefits by the companies cited. I’m not responsible for errors, damages, mistakes o any fraud by websites listed in this e-book. If you don’t want be mentioned here just write me an email to (firstname.lastname@example.org) and I’ll delete any reference of you from this e-book.
Copyright © 2011 Massimo Marrazzo - Biodomotica This document may be used and distributed provided that this copyright statement is not removed from the file and that any derivative work contains the original copyright notice. If you want reproduce, distribute, print articles mentioned in this e-book you must contact owners of copyright, not me. Any of the trademarks, service marks, collective marks, design rights or similar rights that are mentioned, used or cited in “A foldable World” are the property of their respective owners.
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How nanotechnology & printed electronics might lead to foldable and transparent devices