Atom by Atom conference program and speaker booklet

Information PROGRAM SPEAKERS ACTIVITIES

atombyatom into nanoscience

The Nanoscience Cooperative Research Center, nanoGUNE, and the Donostia International Physics Center (DIPC), are proud to welcome you to Atom by Atom. Thank you for accepting our invitation to enter the world of nanoscience and nanotechnology. It’s a world full of possibilities yet to be discovered. Atom by Atom intends to disseminate nanoscience and nanotechnology in a clear and accessible manner, covering different breakthroughs, challenges and implications in a number of fields, such as nanoelectronics, nanomedicine, nanophotonics, nanomaterials, among others. It is an ambitious objective, but we want to go beyond that and offer scientific rigor that goes hand in hand with entertainment and amusement, creating an experience of full immersion in science. We want to foster curiosity, interest, keenness, enthusiasm and critical thinking. We want to showcase science as a cultural activity which can be accessed by the general public. With this aim in mind, our program includes presentations and activities featuring highly prominent researchers. We sincerely hope that Atom

by Atom provides an atmosphere of intellectual freedom

and tolerance which will in turn stimulate a fluent and permanent dialogue between science and society. Get into nanoscience with us!

You can also follow the lectures on the following websites: http://atombyatom.nano gun e.eu http://dipc.ehu.es http://www.nanobasque.eu

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Contents PROGRAM .....................................4

Monday . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Tuesday . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Wednesday . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 SPEAKERS .....................................8

Speech summaries and biographies A C T I V I T I E S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Encounter with Nobel Laureates in kutxaEspacio de la Ciencia . . . . . . 20 Performance Rebufaplanetes with Pep Bou . . . . . . 22

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PROGRAM

Please visit the registration desk 30 minutes before each session to collect your simultaneous interpretation receiver. We would also like to remind you to disconnect your cellular phone upon entering the auditorium.

Thank you for your cooperation and enjoy the sessions.

monday28sept 17:30 – 18:00

Welcome Pedro Miguel Echenique, José María Pitarke and the President of the Basque Government Patxi López Álvarez

18:00 – 18:45

Opening Lecture Sir Harold Kroto THE NOBEL PRIZE IN CHEMISTRY 1996

Science, society and sustainability 19:00 – 19:45

Performance Pep Bou Rebufaplanetes

20:00 – 21:00

Welcoming Reception Banquet Hall, Kursaal Congress Center

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tuesday29sept 10:30 – 13:00

Encounter with Nobel Laureates in kutxaEspacio de la Ciencia

*

Open Forum Sir Harold Kroto Heinrich Rohrer Moderated by Pedro Miguel Echenique

17:30 – 18:15

Felix Goñi Lipidic nanoparticles: fat is beautiful

18:30 – 19:15

Emilio Mendez Nanotechnology and the energy challenge

19:30 – 20:15

Carlos Bustamante Grabbing the cat by the tail: DNA packaging motor End of Session

* ht t p : // ato m b y ato m . n a n o g u n e . e u For more information, see pages 20 –21 or visit:

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wednesday30sept 16:00 – 16:45

Juan Colmenero Molecule by molecule: molecular self-assembly and nanotechnology

17:00 – 17:45

Jose Maiz Nanoscience and nanotechnology: the promise, the reality, and the challenges

18:15 – 19:00

Sir John Pendry Transformation optics and nanotechnology

19:15 – 20:00

Albert Fert Spintronics: fundamentals, recent developments and perspective

20:00 – 20:15

Concluding Remarks Pedro Miguel Echenique, José María Pitarke

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SPEAKERS

Sir Harold Kroto Florida State University (USA) THE NOBEL PRIZE IN CHEMISTRY 1996

Science, society and sustainability Our modern world is precariously balanced on Science, Engineering and Technology (SET); an understanding of these disciplines is vital by all in positions of significant responsibility. Although wise decision-making may not be guaranteed by knowledge, common sense suggests that wisdom is not a likely consequence of ignorance.

SET have revolutionised our lives and there is no doubt that humanitarian contributions have improved the quality of life in the developed world immeasurably.

These improvements were brought about by scientific/technological advances based on doubt and questioning — evidence dependent philosophies totally at variance with the belief-based concepts that underpin all mystical societal attitudes.

Society has the power to use technology so that it can be of benefit or be detrimental. Political decisions have resulted in the existence of some 28,000 nuclear weapons worldwide; in addition it appears that our technologies may have catalysed a mindless plundering of the Planet’s resources. We may be hurtling towards disaster — we may not need an asteroid.

For a 50:50 chance of surviving into the next century, every segment of society, from industrialists, engineers and scientists to politicians, farmers and fishermen must recognise that these issues are the most serious that the human race has ever confronted. Our only hope for survival rests on the shoulders of those who take survival and sustainability issues seriously — and do something about it.

I see a key role for nanoscience and nanotechnology, where chemistry overlaps condensed matter physics, molecular biology and materials engineering. Improved SET education is also vital.

We have manifestly failed in this endeavour but there may be one last hope: the internet is a major new communications technology which we must exploit to educate people on a global scale in the rational attitudes to decision-making that are now vital to our very survival.

Biography Sir Harold Kroto obtained a BSc in chemistry and a PhD in molecular spectroscopy at the University of Sheffield (UK). He spent a large part of his working career at the University of Sussex, where he holds an Emeritus professorship. In 1970, his studies on long linear carbon chain molecules led to the surprising discovery that they existed in interstellar space and also in stars. Sir Harold Kroto was awarded the Nobel Prize in Chemistry in 1996 along with Robert F. Curl Jr. and Richard E. Smalley for the discovery of fullerenes. He has been on faculty at Florida State University (USA) since 2004.

Monday 18:00

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Felix Goñi Universidad del País Vasco/Euskal Herriko Unibertsitatea (Spain) Biophysics Unit, Centro Mixto CSIC-UPV/EHU

Lipidic nanoparticles: fat is beautiful Both contemporary aesthetics and preventive medicine declare that fat should be avoided from diet and body. However, there is a lot to say in favor of fats, which are essential components of all living organisms, without exceptions. The subject of this lecture are the fats (also called lipids) which form the cell membranes, especially phospholipids and cholesterol. Phopholipids have a very interesting property, as they can form nanoparticles spontaneously when dispersed in water.

Lipidic nanoparticles (NPL) can be closed vesicles (liposomes), nanotubes or spherules (micelles). Cell and liposome membranes are in a peculiar physical state: the so-called liquid-crystalline phase. Cholesterol is an essential molecule for life.

Cholesterol itself does not disperse in water, but it integrates NPL and changes their properties. NPL can be used as a vehicle for drugs, to carry them directly to sick cells. Certain specialized fats derived from cholesterol (bile salts) turn diet fats into micelles or nanospheres, so that they can be digested. Some membrane lipids that are found in very low quantities are however very important, because they act catalytically and they modify the properties of the membranes locally.

Among these minority fats, we can mention the ceramides, which are segregated laterally and form specific nanoregions in the membranes, and the diglycerides, which turn the flat structure of membranes into three-dimensional nanostructures (cubic phases). Different types of NPL formed only by lipid and water can be visualized with techniques such as fluorescence confocal microscopy, cryo-transmission electron microscopy, or X-ray scattering. Beautiful images are often obtained that join aesthetic values with scientific and technical interest.

Biography Felix Goñi holds a PhD in medicine and surgery from the Universidad de Navarra (Spain). He completed his studies at the University of London (UK).

Since 1984 he has been senior lecturer of biochemistry and molecular biology at the Universidad del Pais Vasco/Euskal Herriko Unibertsitatea (Spain). From 1995-1999 he served as director of scientific policy for the Basque ministry of education, universities and research, and later became guest lecturer at the University of Victoria (British Columbia, Canada). Between 1994 and 1998 he was also president of the Sociedad de Biofísica of Spain. In 2002 Goñi was awarded the Premio Euskadi de Investigación by the Basque government, and since that time has been director of the Biophysics Unit, Centro Mixto CSIC-UPV/EHU.

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17:30 Tuesday

Emilio Mendez Center for Functional Nanomaterials Brookhaven National Laboratory (USA)

Nanotechnology and the energy challenge The energy crisis is as real and acute as it was a year ago despite the fact that the price of oil has dropped by almost a half. The reason is simple: 80% of the world’s energy consumption is supplied by fossil fuels (petroleum, carbon and natural gas). These energy sources are rapidly depleting, distributed unequally around the world and have negative effects on the environment. Therefore, it is essential to reduce energy consumption (e.g., more efficient systems for energy transmission, storage and use) and to develop renewable, non-polluting energy sources.

This urgent challenge is particularly hard to address while also trying to meet society’s demands for unlimited economic growth.

The potential revolution by nanotechnology may play a decisive role in meeting the energy challenge. Nanotechnology exploits the unique properties of matter at dimensions of only a few nanometres, in other words, 100,000 times thinner than a human hair. At this scale there are materials that are cheaper than conventional catalysts which can conduct electricity better than copper or aluminium, or accelerate chemical reactions, or even convert sunlight into electricity more efficiently than today’s solar panels. But in order to utilise these materials in a practical and economic fashion, we must first answer some important scientific questions and find solutions to some serious technical problems. The answers and solutions will only be possible through the collective and coordinated efforts of scientists and engineers and with the vigorous and continued support from society for research in nanoscience.

Biography Emilio Mendez earned his undergraduate degree in physics from Universidad Complutense in Madrid (Spain) and received his PhD in physical sciences from the Massachusetts Institute of Technology (USA). For fifteen years he worked at the IBM Watson Research Center in New York and joined Stony Brook University in 1995 as a physics professor. He has also been Distinguished Visiting Professor at the NTT Basic Research Laboratories (Japan) and the Paul-DrudeInstitut (Germany), and Distinguished Professor with Fundación BBVA and Fundación Iberdrola at the Universidad Autónoma de Madrid (Spain). He is a member of the Fundación Consejo España-Estados Unidos and a Fellow of the American Physical Society. Mendez has received several awards, including the Premio Príncipe de Asturias 1998 and the first Fujitsu Quantum Device Award in 2000. In 2006 he became the director of the Center for Functional Nanomaterials at Brookhaven National Laboratory (USA).

Tuesday 18:30

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Carlos Bustamante University of California, Berkeley (USA)

Grabbing the cat by the tail: DNA packaging motor As part of their infection cycle, many viruses must package their newly replicated genomes inside a protein capsid to insure its proper transport and delivery to other host cells. Bacteriophage φ29 packages its 6.6 mm long double-stranded DNA into a 42 nm dia. x 54 nm high capsid using a multimeric ring motor that belongs to the ASCE (Additional Strand, Conserved E) superfamily of ATPases. These ring motors are found in all forms of life and are responsible for a remarkable range of cellular functions, from translocation of nucleic acids, and the unfolding of polypeptides to the synthesis of ATP. A number of fundamental questions remain as to the coordination of the various subunits in these multimeric rings. The portal motor in bacteriophage φ29 is ideal to investigate these questions and is a remarkable machine that must overcome entropic, electrostatic, and bending energies to package the DNA to near-crystalline density inside the capsid.

Using optical tweezers, we find that this motor can work against loads of up to ~57 picoNewtons on average, making it one of the strongest molecular motors ever reported. We establish the force-velocity relationship of the motor and find that the rate-limiting step of the motor’s cycle is force dependent even at low loads. Interestingly, the packaging rate decreases as the prohead is filled, indicating that an internal pressure builds up due to DNA compression. We determine that the capsid pressure at the end of the packaging is ~6 MegaPascals, corresponding to an internal force of ~52 pN acting on the motor. We have identified where in the mechanochemical cycle the chemical energy of ATP is converted into mechanical work. Using ultra-high resolution optical tweezers, we have performed the first direct measurement of the step size of a translocating ring ATPase. What emerges is a surprising mechanism that involves a step size with a non-integer number of base pairs and that reveals an unexpected degree of coordination among the individual subunits that has not been proposed previously for a ring ATPase. These surprising observations have forced us to reconsider the standard models by which DNA translocases engage DNA and to propose new models by which conformational changes in the ring are converted into DNA motion.

Biography Carlos Bustamante received a BS in 1981 from Universidad Peruana Cayetano Heredia in Lima (Peru) and a PhD in biophysics from the University of California, Berkeley (USA). Since 1994, he has held an appointment as a Howard Hughes Medical Institute Investigator. He is professor of biochemistry and molecular biology, physics and chemistry at UC Berkeley and head of the Advanced Microscopies Department at Lawrence Berkeley National Laboratory.

Bustamante has received numerous awards and holds several advisory roles within UC Berkeley and the larger scientific community.

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19:30 Tuesday

Juan Colmenero Universidad del País Vasco/Euskal Herriko Unibertsitatea (Spain) Centro de Física de Materiales, Centro Mixto CSIC-UPV/EHU Donostia International Physics Center

Molecule by molecule: molecular self-assembly and nanotechnology The term “self-assembly” is traditionally used to define the process by which certain molecules under certain conditions spontaneously associate to form thermodynamically stable geometric structures (aggregates). Self-assembly phenomena are widely observed in nature and the units that associate are not only molecules but can also be atoms, colloidal particles, macromolecules (polymers) and biological molecules, such as lipids and peptides.

The objects formed by self-assembly are usually tens or hundreds of nanometers in size (1 nanometer = 10-9 meter, i.e., 0.000000001 meter), hence the interest in self-assembly processes in relation to current developments in nanoscience and nanotechnology. Simply defined, nanotechnology is the ability to manipulate atoms and/or molecules (structural units) to create structures (aggregates) at the nanometric scale which show emerging properties of technological interest. The process of obtaining nanometric structures through atomic or molecular manipulation is obviously similar to spontaneous self-assembly. The major difference, however, is that atomic or molecular manipulation calls for highly sophisticated technological means and is usually a process which requires investment in time, effort and money. The beauty of self-assembly is that it occurs spontaneously under the appropriate conditions. Therefore, it is not difficult to imagine that an in-depth understanding and control of the self-assembly processes would make it possible to define simple methods for obtaining nanostructures with adjustable sizes and properties. In this way, self-assembly becomes one of the key processes in the development of nanotechnology.

Biography Juan Colmenero is professor at the Universidad del Pais Vasco/Euskal Herriko Unibertsitatea (Spain). He has been visiting professor at IFF Forschungszentrum Jülich (Germany) and has been on numerous international scientific committees, most notably Institut Laue-Langevin (France) and the Jülich Centre for Neutron Science. He is also member of the editorial boards of the Colloid & Polymer Science, Journal of Polymer Science Part B and Polymer Physics.

His work has earned him a number of distinctions including Premio Xabier María Munibe en Ciencia y Tecnología (1998) and Premio Euskadi de Investigación (2000) granted by the Basque government, and a medal from the Real Sociedad Española de Física (2003).

Wednesday 16:00

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Jose Maiz Intel Corporation (USA)

Nanoscience and nanotechnology: the promise, the reality, and the challenges The terms nanoscience and nanotechnology refer to the comprehension, ability to manipulate and productive use of the unique physical properties of particles and structures of nanometric dimensions. We are undeniably at the beginning of a technological revolution that will result in many new products with a profound impact in the fields of materials, electronics, medicine and consumer products. Although we still do not know what the final impact of this revolution will be, it will likely follow the same model as other major transformations, such as electronics, the invention of antibiotics, the internal combustion engine or the human genome decoding. Development in all of these cases was gradual and although progress at first seemed slower than originally predicted, they all ended up having a much greater overall impact than initially expected and in ways that no one could have imagined. Twenty-five years ago, who would have imagined the profound impact the computer, wireless communications and the Internet would have on economics, labour and globalisation? Such a thing was unfathomable, even though forty years have gone by since the discovery of the transistor. This presentation will explore the basic trends, gradual impact and some of the future directions of the nanometric revolution. As in previous cases, investing in training a highly qualified workforce and in developing an ecosystem that encourages the speedy translation of discovery into products with technological, industrial and social impact will be key to this revolution. Societies that are capable of making such investments will benefit enormously not only from the products themselves, but also from an economy based on innovation

Biography Jose Maiz graduated with a degree in physics from the Universidad de Navarra (Spain) in 1976. Upon completion of his PhD in electrical engineering at the Ohio State University in 1983, he joined Intel Corporation. Over his 25-year career at Intel, he has worked on the development of 11 semiconductor technology generations and was named Intel Fellow in 2002. Maiz was recognized as an IEEE Fellow in 2008 for his contributions to the reliability of integrated circuits.

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17:00 Wednesday

Sir John Pendry Imperial College London (UK)

Transformation optics and nanotechnology Conventionally we control light only with a precision equal to the wavelength — about 0.5microns for visible light. Now researchers wish to integrate optics with nanotechnology and this demands new theoretical tools to enable this goal. Transformation optics is a new technique in optics which in principle enables control of light with unlimited precision. Combined with the new metamaterials transformation optics is a powerful tool for the control of light on all length scales. I shall describe the theory and give some examples of nanostructures that shape light to nanometric precision. Every day materials owe their properties to the individual atoms and molecules from which they are composed. The macroscopic electromagnetic fields are averages over the fluctuating local fields, averages that are very well defined as there are typically billions of molecules contained in one cubic wavelength of matter. Metamaterials extend this concept replacing the molecules with man made structures that might have dimensions of nanometres for visible light or in the case of GHz radiation may be as large as a few millimetres, but still much less than the wavelength. In this way properties are engineered through structure rather than through chemical composition. Metamaterials give enormous choice of material parameters for electromagnetic applications. So much so that we might ask if there is a new way to design electromagnetic systems exploiting this new flexibility. In an ideal world magnetic and electrical field lines can be placed anywhere that the laws of physics allow and a suitable metamaterial found to accommodate the desired configuration of fields. It was to answer the question of what parameters to choose for the metamaterial that we developed transformation optics. The idea is quite straightforward: start with a field pattern that obeys Maxwell’s equations for a system that is topologically similar to the desired configuration but confined either to free space or a simple configuration of permittivity and permeability, then distort the system until the fields are in the desired configuration. Next rewrite Maxwell’s equations using the new coordinate system. Some time ago it was shown that Maxwell’s equations are of the same form in any coordinate system but the precise values of permittivity and permeability will change.

These new values of permittivity and permeability are the ones we must give to our metamaterial if we want the fields to take up the distorted configuration.

Biography Sir John Pendry is a theoretical physicist. He has worked at the Blackett Laboratory, Imperial College London (UK) since 1981. He began his career in the Cavendish Laboratory at University of Cambridge, followed by six years at the Daresbury Laboratory of the Science and Technology Facilities Council where he headed the theory group. In collaboration with the Marconi Company he designed a series of “metamaterials”. These made accessible completely novel materials with properties not found in nature. Sir John Pendry was head of the department of physics at Imperial College London and principal of the faculty of physical sciences. He is also an honorary fellow of Downing College at Cambridge and an IEEE Fellow. In 2004 he was knighted for his services to science.

Wednesday 18:15

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Albert Fert Université Paris-Sud (France) Unité Mixte de Physique CNRS/Thales THE NOBEL PRIZE IN PHYSICS 2007

Spintronics: fundamentals, recent developments and perspective The basic concept of spintronics is the manipulation of spin currents, in contrast to mainstream electronics in which the spin of the electron is ignored. It takes its roots in results of fundamental research on the electrical conduction in ferromagnetic conductors and its development followed the discovery of the Giant Magnetoresistance (GMR) of the magnetic multilayers in 1988. Today spintronics is a field of research in considerable expansion along many novel directions.

After an introduction on the fundamentals of spin dependent conduction, the GMR and the applications of GMR, I will focus on recent developments in spintronics. This will include a review of results on spin transfer effects (magnetic switching or generation of microwave oscillations by injection of spin angular momentum from an electrical current), on spintronics with semiconductors and on spintronics with carbon-based materials. The synchronization and phase locking of a collection of STO’s (Spin Transfer Oscillators) is an example of the important new problems raised by the progress in the generation of microwave oscillations by spin transfer. Other examples of challenging fields of research are molecular spintronics and single electron spintronics.

Biography Albert Fert received master’s degrees in mathematics and physics from the École Normale Supérieure (France) and in 1970 he earned a PhD in physical science from the Université Paris-Sud. Since 1976 Fert has been professor at Université Paris-Sud and in 1995 became scientific director of the joint laboratory, Unité Mixte de Physique CNRS/Thales, a collaboration between the Centre National de la Recherche Scientifique and Thales Group. He is also an adjunct professor of physics at Michigan State University (USA). In 1988 Fert discovered the giant magnetoresistance (GMR) effect in multilayers of iron and chromium which is recognized as the birth of spin transport electronics or “spintronics”. GMR was simultaneously and independently discovered by Peter Grünberg at Forschungszentrum Jülich (Germany). For the discovery of the giant magnetoresistance effect, Fert was awarded the 2007 Nobel Prize in Physics together with Peter Grünberg.

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19:15 Wednesday

Heinrich Rohrer THE NOBEL PRIZE IN PHYSICS 1986

Heinrich Rohrer was born in Buchs (Switzerland). He received his PhD in experimental physics in 1960 from the Swiss Federal Institute of Technology (ETH Zürich) with a thesis on superconductivity. After a post-doctorate at Rutgers University in New Jersey (USA), he joined IBM’s Zurich Research Laboratory in 1963 as a research staff member. His research interests included Kondo systems, phase transitions, multicritical phenomena, scanning tunneling microscopy, and, most recently, nanomechanics. He retired from IBM in 1997 and took research appointments at CSIC (Spain) and RIKEN (Japan).

For the invention of the scanning tunneling microscope, together with Gerd Binnig, professor Rohrer was co-recipient of the King Faisal Prize and the Hewlett Packard Europhysics Prize in 1984, and the Nobel Prize in Physics in 1986. In 1987, he was awarded the Cresson Medal of the Franklin Institute in Philadelphia, Pennsylvania (USA). The practical value of the invention was recognized by the induction to the US National Inventors Hall of Fame in 1994. In addition, he is a member and honorary member of various professional societies and academies. He has also received honorary degrees from several universities.

Nobel Laureates Sir Harold Kroto and Heinrich

Encounter with Nobel

Laureates

in kutxaEspacio de la Ciencia

Rohrer with Professor Pedro Miguel Echenique will participate in an interactive session for school children. See pages 20 –21 for more information.

The activity is sponsored by kutxaEspacio with the support of the Department of Education, Universities and Research of the Basque Government via the Suspertu Project.

http: // atombyatom .nan o g un e. eu

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ACTIVITIES

Encounter with Nobel Laureates in kutxaEspacio de la Ciencia . . . . . . . . . . . . . . . . . . 20 Performance Rebufaplanetes with Pep Bou . . . . . . . . . . . . . . . . 22

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Encounter with Nobel

Laureates

in kutxaEspacio de la Ciencia

The Atom by Atom program features an interactive session involving school children, Nobel Laureates Sir Harold Kroto and Heinrich Rohrer, and Professor Pedro Miguel Echenique. The session is geared toward physics and chemistry teachers and students of the 2009/10 term in fourth year of secondary education and first and second year of high school. You can also follow Encounter with Nobel Laureates on the Obra Social de kutxa website at: www.kutxasocial.net/img-mant.nsf/kutxa-html/ Premios-Nobeles.html The activity is sponsored by kutxaEspacio de la Ciencia with the support of the Department of Education, Universities and Research of the Basque Government via the Suspertu Project.

htt p://atombyatom .nan o g un e.eu 20

tuesday29sept 10:30 – 13:00

Encounter with Nobel Laureates in kutxaEspacio de la Ciencia

10:30 – 11:30

Open Forum Sir Harold Kroto Professor of Chemistry Florida State University (USA) THE NOBEL PRIZE IN CHEMISTRY 1996

Heinrich Rohrer THE NOBEL PRIZE IN PHYSICS 1986

Moderated by Pedro Miguel Echenique

11:30 – 12:00

Coffee Break

12:00 – 13:00

Question & Answer Session Students ask the three scientists questions

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monday28sept 17:30 – 18:00

Welcome Pedro Miguel Echenique, José María Pitarke and the President of the Basque Government Patxi López Álvarez

18:00 – 18:45

Opening Lecture Sir Harold Kroto THE NOBEL PRIZE IN CHEMISTRY 1996

Science, society and sustainability 19:00 – 19:45

Performance Pep Bou Rebufaplanetes

20:00 – 21:00

Welcoming Reception Banquet Hall, Kursaal Congress Center

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REBUFAPLANETES Pep Bou began his career 27 years ago with Bufaplanetes. The current performance is a new version of that now classic piece of Catalonian theater seen by audiences throughout Europe.

Bubbles are science in action A bubble is a thin film of soapy water. The film that makes the bubble has three layers. A thin layer of water is sandwiched between two layers of soap molecules. Each soap molecule is oriented so that its polar (hydrophilic) head faces the water, while its hydrophobic hydrocarbon tail extends away from the water layer. No matter what shape a bubble has initially, it will try to become a sphere. The sphere is the shape that minimizes the surface area of the structure, which makes it the shape that requires the least energy to achieve.

When two bubbles meet, they will merge walls to minimize their surface area. If bubbles that are the same size meet, then the wall that separates them will be flat. If bubbles that are different sizes meet, then the smaller bubble will bulge into the large bubble. Bubbles meet to form walls at an angle of 120°. If enough bubbles meet, the cells will form hexagons.

Taken from “Learn the Science of How Bubbles Work” by Dr. Anne Marie Helmenstine, About.com.

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atombyatom thanks

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Atom by Atom supports San Sebastian 2016

ht t p : // ato m b y ato m . n a n o g u n e . e u

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atombyatom into nanoscience

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