CONVERGENCE The Magazine of Engineering and the Sciences at UC Santa Barbara
Photovoltaics with a Twist
Location, Location, Location Watching Your Brain Q & A with Nobel Laureate David Gross The UV Lagoon
Primordial Nano Soup WINTER 2005, ONE 1
Welcome to Convergence, a new magazine that
embodies a core idea here at UC Santa Barbara. We call it “science without silos.” Convergence is about the people in science and engineering at UCSB. Even more than that, it’s about how they work across disciplines to expand knowledge and push back the frontiers of technology. UCSB is well known for such creative interaction, and Convergence puts a spotlight on it. UCSB is distinctly committed to dissolving artificial barriers between fields of science and engineering while continuing to teach the core knowledge that each discipline requires. We hope you find Convergence to be a window into the exciting work of the university -- and that you’ll want to learn even more.
Matthew Tirrell Dean, College of Engineering
Martin Moskovits Dean of Mathematical, Life and Physical Sciences, College of Letters & Science
Evelyn Hu Co-Director, California NanoSystems Institute
WINTER 2005, one
David Gross Q&A
UCSBâ€™s newest Nobel Laureate talks about education, the university and the joy of science.
6 10 16 22
News and events from Engineering and the Sciences at UC Santa Barbara.
Lighting the Way Researchers focus on photonic switching to remove the remaining roadblocks on the optical Internet.
What Is This Thing? Location, Location, Location
The UV Lagoon Engineers and marine scientists pioneer the practice of ecotechnology, working together to revive coral reefs.
Watching the Mind at Work
What actually happens when we think? Real-time brain imaging has some answers to that question.
Satellites, software and wireless technology are giving social science a new sense of place.
SPECIAL POSTER PULL OUT The Electromagnetic Spectrum: Waves that we all ride on. PAGE 12-13
UCSB scientists see a bright future for photovoltaics, the technology of producing electricity from sunlight. And theyâ€™re spreading the word with a documentary.
CONVERGENCE Th e M a g a z in e o f
E n g i n e e r i ng 3and the Sciences at UC Santa Barbara
David J. Gross, awarded the 2004 Nobel Prize in physics, has been helping UCSB stay on the leading edge of research since he came to the university in 1997. He is a professor of physics and heads the university’s Kavli Institute for Theoretical Physics. Before coming to Santa Barbara, he did graduate work at UC Berkeley, was a junior fellow at Harvard and, from 1969 to 1997, taught at Princeton University. His Nobel Prize, shared with H. David Politzer of the California Institute of Technology and Frank Wilczek of the Massachusetts Institute of Technology, recognizes his pathbreaking work on the structure of the atomic nucleus and the fundamental nature of matter. The Royal Swedish Academy of Sciences noted that the three scientists’ “discovery of asymptotic freedom in the theory of the strong interaction” in 1973 has “brought physics one step closer to fulfilling a grand dream, to formulate a unified theory comprising gravity as well––a unified theory for everything.” Gross, 63, continues that quest today, with a focus on string theory. Convergence recently talked with him about education, the excitement of science and how UCSB and the Kavli Institute are advancing scientific knowledge.
Tell us something about the process that put you on your career path. At what point did you decide on science, and on physics in particular, as your life work? I was 13 or 14 when I first became seriously interested in science. I was reading a lot of popular science books at the time, by authors like Arthur Eddington and George Gamow, and these really excited me. So I thought I wanted to be a theoretical physicist. I don’t think that I knew at the time what that meant, but it just seemed exciting to find out how nature worked. Then I tried to read more serious books on physics on my own. I saw that by using mathematics and using your mind, you could figure out new things. Would you say that your education — especially in the early years – gave you the right encouragement and preparation for a scientific career? I went to high school in Israel, where the teaching overall was probably better than I would have received in the United States. But physics wasn’t very well taught. And I taught myself the math so that I could get out of class. I did undergraduate work in Israel, then to Berkeley for grad work. I was born in Washington D.C., and I wanted to go back to America. Berkeley was great. In fact, my education got better and better as I went along. At least for me, the further I got along, the closer I got to the frontier where I could do science myself, the more fun it was, and the more I learned. The best education is to do research. Do you think universities in the U.S. are adequately preparing the next generation of scientists? At the undergraduate level there’s an incredible variation in the quality of scientific education; some is good, some is bad. But at the graduate level the teaching in the U.S. is by far the best in the world. Everybody knows that, and that’s why so many graduate students come here. Tell us a little about your move to UC Santa Barbara from Princeton. What was it that attracted you to UCSB, the West Coast and your role at the Kavli Institute for Theoretical Physics? Partly, it was time for a change. I had been at Princeton for 27 years, and it was nice to have the new challenge of leading the Institute. I knew the institute well and it was a wonderful place. I liked California, too. After going to graduate school in Berkeley, I vowed I would come back.
PICTURE WILL CHANGE
to do things that can’t be done elsewhere. We also try to take initiatives in developing new areas of what usually is called physics.
Science departments at UCSB place great stress on interdisciplinary work. Is this level of cross-fertilization exceptional for a U.S. university?
Tell us something about current work being done at the Institute.
I spent most of my academic life at Princeton, which is a great university but one with strong barriers among disciplines. One of its traditions is not to have strong relationships between departments. Santa Barbara is different from that. It has bootstrapped itself from being a second-rate institution to a top-flight one by creating a culture of departments helping each other.
Right now, we’re growing a program in theoretical biology. Many theoretical physicists are looking at what has happened in biology in last decade – such as the human genome project. You have so much data and so many components identified. Now you have to figure out their physics — how they work. Biologists have long resisted theory because theory never did anything for them, except for Darwin’s theory, which has worked well. But their attitude is different now.
The Institute has had a big role in that, as has the College of Engineering. It’s also just the attitude of the people here — they really wanted to improve rapidly. They weren’t worried, as people often are, about hiring people who were better than themselves. They also created a culture of working together that works remarkably well.
Speaking of new areas for physics-related research, is there a limit to how much the traditional barriers between disciplines can be broken down?
What do you see as the role of the Kavli Institute in relation to other organizations for advanced physics research? Do you see the Institute filling a unique niche?
One of the things I did when coming here was an effort to explore the relationship between physics and biology; many physicists are resistant to that idea because biology isn’t “physics,” as traditionally defined. But disciplines also have a valid role in training scientists. There’s always pressure from graduate and undergraduate students to change the character of the courses, but I think it is still
It’s a very unique institution — probably the first of its kind when it was created 25 years ago. There are many national labs, which are centers built around facilities, but this is the first facility for theoretical users. Its main function is to serve as a center for conferences, projects and other activities, hosting about 1,000 visitors a year, with probably 30 percent from outside this country. It has been copied, mainly in mathematics, but I think it’s still unusual in physics.
"Biologists have long resisted theory because theory never did anything for them," says Gross.
We have certain goals: To run, choose and manage programs, to help the best scientists interested in a particular problem come together in a carefree atmosphere, to work on the problem and interact across disciplines in ways they could not do at home. We do other things to help the community of theoretical physics, broadly considered. For instance, we have had some success in bringing the best graduate students here for six months at a time. The Institute has a public lecture series, a journalist-in-residence program for science journalists, and a program to re-invigorate college teachers who still want to have an active research life. In general, we try
Professor David Gross seated with members of the Royal Swedish family at the Nobel banquet in Stockholm.
essential to preserve the disciplines at least through some point in graduate school. They train you to think in a particular way, and you would lose that if you broke down boundaries between disciplines. Astrophysics is an example. As a theoretical science, it has existed only since early in the 20th century, and you still couldn’t have the astrophysics without the physics. Even today, all the good astrophysicists get their undergraduate and graduate degrees in physics departments. You mentioned some of the Institute’s public outreach activities, such as public lectures and programs for journalists. How important are these to the Institute’s – and the university’s – mission? They’re very important. We have a public lecture series because, much more than newspaper editors are willing to admit, people are turned on by science. It’s important to convey the excitement of science. That’s often why kids turn to it – as I know from my own life.
Lighting the Way Researchers at UCSB, Stanford and technology firms work to remove roadblocks on the fiber-optic Internet. The challenge: To come up with a high-capacity, powersaving photonic packet switch.
How fast is the Internet? The answer depends on where you sit, in time as well as space. If you judge it by the standards (and demands) of five years ago, its speed is blinding and its capacity is virtually limitless. But it looks far less adequate in view of what users are likely to demand just a few years from now. And in the here and now, it presents a mixed picture of wide-open data superhighways and emerging bottlenecks. Fiber optics have created plenty of room for traffic growth between Internet nodes, where data is processed and routed to its ultimate destination. But at each of those junctions, the light signals have to be converted to electronic form for routing, and then reconverted to light. How much does this optical-electric-optical (OEO) process slow things down? Maybe not much now, but just wait until millions of Internet users simultaneously want to download high-definition DVDs in a few seconds. When that day comes, the best of today’s routers may not be up to the task. One way to get rid of any potential OEO roadblock is to drop the “E”– that is, route the photons without having to convert them to electrons. Researchers at the UCSB School of Engineering have been pursuing this vision for a number of years, working to create the switching technologies for an all-optical Internet. Now, joined by industry and academic colleagues and with funding from the Defense Advanced Research Project Agency (DARPA), they are eyeing an especially ambitious goal: A system that routes packets, the basic data units of the Internet, with no optical-to-electric conversion.
A $16 MILLION PUSH
Their project, named LASOR for Label Switched Optical Router, started in April 2004 with the first in a series of DARPA grants that will total $15.8 million over four years. It is led by Daniel J. Blumenthal, UCSB professor of electrical and computer engineering, and includes Stanford University as well as several major technology firms — Cisco Systems, JDS Uniphase, Agility Communications and Calient Networks. The LASOR team aims ultimately to shrink the size of state-of-the-art routers, which now take up a full 7-foot equipment rack, down to a single linecard. It also wants to push optical router
Professor Daniel Blumenthal
receivers. A router reads each packet’s digital address label and sends it on its way to be reconstituted at its eventual destination. So there’s a great deal of data to sort, and a great deal to be stored while the sorting goes on.
capacity to more than 100 terabits (trillion bits) per second. That’s about 100 times the capacity of the most advanced routers today. These are tall technological orders, but LASOR is not starting from scratch. It builds on achievements in optical switching technology, at UCSB and elsewhere, dating back well into the 1990s. During that decade, the university’s Multi-disciplinary Optical Switching Technology program (MOST) developed photonic circuit switches and hatched Calient Networks, which sells them to major telecommunications carriers. Blumenthal co-founded Calient in 1999 along with another UCSB engineering professor, John Bowers.
In today’s Internet, routers read packets to see where they’re headed and to determine which path (such as a fiber or a wavelength) to put them on next. In an optical router, the packet would have to carry some form of optical identification instead of (or in addition to) its electronic address. Blumenthal and other UCSB researchers are looking to solve this problem with a standard called All-Optical Label Switching (AOLS), in which packets are tagged with optical labels that can route them independently of their bit-rate, length or coding format. AOLS would require the router to read only the small label, not the full packet header, thereby streamlining the routing process.
Later, in 2003, a UCSB research team created the world’s first tunable “photon copier,” which uses all-optical technology to transcribe data from one light wavelength to another. It’s role in a router would be to direct packets using the color of light rather than flows of electricity.
"If you can’t buffer them, you have to drop them," says Bowers.
The copier was a breakthrough not just because it eliminated the electronic middleman in a key switching function, but also because it integrated two devices, a widely tunable laser and an all-optical wavelength converter, on the same chip. Blumenthal says this integration is crucial in making optical switching practical for the Internet. “The core idea [of LASOR] is to increase the number of components at the chip level for a certain function,” he says.
Another significant technical hurdle is buffering. John Bowers, who is focusing his research on this problem, points out that all commercial electronic routers “have a huge amount of memory in them,” in which packets are held during the routing process. “If you can’t buffer them, you have to drop them,” says Bowers. But photons, unlike electrons, are hard to store. Bowers is working on “delay lines,” wafers with wave guides that divert the photonic packets into a sort of holding pattern as they are being processed. He is also investigating “slow light,” a method of retarding the propagation of light so that photons can be packed into smaller spaces.
The challenge ahead is to apply integrated systems such as the photon tuner to packet switching, a task that takes optical technology to a new level of complexity. In circuit switching, used for voice telephony, all data between a sender and receiver travels on one dedicated path, with no other data allowed on it, once a connection is made. In packet switching, each path contains countless tiny data packets (thousands from a single e-mail message) that come from different senders and are headed to different
In the near term, Bowers says LASOR’s goal for the summer of 2005 is to build an all-optical packet router by the summer of 2005. “That would be pretty exciting,”
Professor Dan Blumenthal and post doctoral student Wei Wang in the photonics lab in the newly-opened Engineering Science Building he says– but nothing compared to the breakthroughs that may come after that. Blumenthal says LASOR is akin to the groundbreaking technological advances early in the semiconductor revolution. The state of optical switching today, he says, is “the equivalent of where electronics was in the 50s,” when scientists were just learning how to arrange transistors into integrated circuits on silicon chips. Blumenthal sees the same kind process starting in photonic switching, spurred (as was the creation of ICs) by the need for speed, power and low cost. “If you’re not going to do any significant data processing on the chips, then the faster and faster you go, the more power you’re going to burn up,” he says. The 100-terabit photonic packet switch may still seem far off, but with Internet traffic doubling each year, the point at which the market will demand such capacity is just around the corner. Forty years ago, the interaction of demand with engineering ingenuity set off explosive growth in the processing power of semiconductors. The same forces are at work today in optical technology. Just as electronics rapidly transformed the universe of information then, photonics could be poised to make a similar leap, with help of UCSB and LASOR, right now.
Professor John Bowers
UCSB researchers use real-time brain imaging to shed light on how humans think. James J. Blascovich, professor and chair of the Department of Psychology, says functional magnetic resonance imaging (fMRI) technology can help scientists better understand how people learn, how they tell the real from the make-believe and how they retrieve memories. It could illuminate the brain’s most subtle actions and, in Blascovich’s words, help “put the mind and body back together.” Similarly to the way an MRI uses a magnetic field to produce a snapshot of the brain’s anatomy at one point in time, fMRI produces a video that tracks blood flow as regions of the brain are activated over time. Researchers use it to see what occurs biologically when someone is asked to perform a particular mental task or is given certain sensory cues. One task getting researchers’ attention is the act of attention itself. What goes on in the brain when we focus on something in our environment? Barry Giesbrecht, an assistant professor of cognitive and perceptual sciences at UCSB, has conducted experiments in which he instructs people to attend to an object such as a rectangle in a cued location (where attention has been directed) as opposed to an uncued spot. “The strength of fMRI lies in its specificity,” Giesbrecht says, “it allows us to measure ongoing cortical activity evoked by key cognitive functions like attention.”
Blascovich hopes to have the facility finished by June 2006. The university has provided initial funding for construction, he says, and “we are seeking additional necessary support” for such things as fMRI equipment “through development efforts and research funding agencies so that the brain imaging center as part of the mind science initiative can be active when the physical facility is completed.” “Mind science” as Blascovich defines it, is “the study of psychological, biological, and computational processes that govern mental function.” As such, it brings a wide range of disciplines together from the physical and social sciences, and it covers much more than fMRI brain imaging. But fMRI research is crucial because it embodies the core idea of the mind-science enterprise – that the mind and the brain occupy the same reality, and that the workings of the mind can legitimately be studied with the methods of physical science.
Other UCSB researchers are using fMRI to look at episodic memory (how the brain recollects specific events, real or imagined), at the differences between types of tasks, such as memory and spatial judgment, and at social interaction (how people are subtly or automatically influenced by one another). Diane Mackie, professor and vice-chair of social psychology, sees therapeutic potential as fMRIs show how these cognitive processes work: “Many people think that some kind of malfunction in the system for reasoning about social information is related to autism.”
“Over the last 20 to 25 years, Blascovich says, “psychological scientists have sort of put the nail in the coffin of mind-body dualism.” He adds that now, with the advent of programs such as the Mind Science Initiative, “there is good reason to think that mind science may well become the major intellectual undertaking of this century.”
The practical impact of fMRI research could be broad and deep. The studies of attention and retrieval of memories, for instance, could lead to more effective methods of teaching and training, in and outside the classroom. At present, UCSB’s researchers lack fMRI capability of their own. Mackie says they have an arrangement to use the research-oriented fMRI equipment at Dartmouth College – a better arrangement, she says, “than having to get magnet time at medical schools.” But plans are moving forward to launch a new Mind Science Initiative, including fMRI equipment, in the lower level of UCSB’s new Psychology Addition.
WHAT IS THIS ?
See answer on inside back cover
News and Events from the Engineering and the Sciences at UC Santa Barbara
The center’s mission is to promote global excellence in materials science and engineering through a series of research and educational programs. The ICMR will offer an international materials science forum for scientists and engineers and will create international programs, including workshops, exchange programs, visitors programs and summer schools. Tony Cheetham, who has led UCSB’s Materials Research Lab (MRL) for the past 12 years, has been named the ICMR’s director. He is supported by a faculty steering committee and an international advisory board, chaired by Professor C.N.R. Rao, president of the Third World Academy of Sciences (TWAS). The ICMR’s partners at UCSB include the MRL, the UCSB Materials Department and the California NanoSystems Institute (CNSI). The center is also working with 16 partner institutions, including the International Center for Theoretical Physics and TWAS, both located in Trieste, Italy. Other partner institutions are located in India, South Korea, Singapore, Mexico, Chile, Israel, Germany, Australia, France, and Switzerland.
UCSB Geographer Wins NASA Award in Earth Sciences Christopher Still, an assistant professor of geography at UCSB, has been given a NASA New Investigator Program in Earth Sciences Award for his proposal, “C4 Photosynthesis and the Carbon Cycle: An Integrated Plan of Research and Education.” Still plans to combine remote sensing data provided by several NASA satellites with models of atmospheric circulation and the terrestrial carbon cycle. The three-year award will provide a total of $350,000.
Russell Kightley Media www.rkm.com.au
New International Center for Materials Research (ICMR) Funded with $3.5 million NSF Grant A new International Center for Materials Research at UCSB has been established with a five-year, $3.5 million grant from the National Science Foundation.
Still’s project is aimed at understanding the role of “C4” plants, mostly from tropical and subtropical grasslands and savannas, in the global carbon cycle. Many of the world’s most aggressive weeds are C4 plants and they can grow very quickly. But they are also important crop plants such as corn, sorghum and sugar cane. Understanding these plants is important because they respond differently than most other plant types to changes in light, temperature, and atmospheric carbon dioxide. Still wants to learn how these plants will respond to climate change and variations in atmospheric composition and how much carbon dioxide they take from and release into the atmosphere during photosynthesis and respiration.
Graduate Students from U.C. Santa Barbara's ICMR program visist Jawaharlal Nehru Center for Advanced Scientific Research in Bangalore, India
CNR Rao (Chair of the International Advisory Board, ICMR), Tony Cheetham (Director, ICMR) and David Gross (Member, ICMR Steering Committee) at the first meeting of the International Advisory Board on November 19, 2004 in Paris, France.
The image above shows a generalized composite plant cell. In this diagram, the plant cell is surrounded by a cell wall (in this picture just the primary cell wall is shown). The green discoid structures at the cell periphery are chloroplasts, where C3 and C4 photosynthesis occurs.
News and Events from the Engineering and the Sciences at UC Santa Barbara
Engineering Science Building Opens The new, 54,000-square-foot, $30million Engineering Science Building was officially opened on October 22, 2004, with more than 350 friends, alumni, faculty and students there to participate. Guest speakers Robert F. Leheny, deputy director of the Defense Advanced Research Projects Agency (DARPA), and Neal Hunter, chairman of Cree, Inc., lauded the progress of UC Santa Barbara in their remarks.
and Sue Cooper were recognized with the naming of the Steve (‘68) and Sue Cooper Computer Lab, and Craig (‘72) and Gayle (‘75) Cummings were recognized with the naming of the Craig and Gayle Cummings Mountain Terrace. These individuals made leadership gifts to support the priorities of Dean Matthew Tirrell, including the building of a novel Technology Management Program within the College of Engineering that prepares UCSB students to be leaders in growing technology companies.
The three-story incubator for emerging technologies includes 19 research laboratories and 24 faculty offices. The faculty and students there are involved in materials science, solid state lighting, photonics for telecommunications, high-speed electronics, micro-electro mechanical systems and chemical and biological engineering. The College of Engineering had the honor of recognizing some of its most generous contributors, many of whom are UCSB alumni, through named spaces within the Engineering Science Building. Mark (‘66) and Susan Aas (‘67) Bertelsen were recognized with the naming of the Bertelsen-Aas Conference Room and Terrace, Steve
“Much of the work is taking place where the disciplines of mechanical, electrical, chemical and biological engineering and materials sciences intersect,” said Associate Dean Umesh Mishra. “A lot of the low-hanging fruit in new advances occurs at the boundaries. That philosophy has been transferred to this building. By bringing all these people together, we will make new discoveries based on these interactions.”
News and Events from the Engineering and the Sciences at UC Santa Barbara 33-Year Hunt for Proof of Spin Current Now Over A group of researchers led by David D. Awschalom, professor of physics and electrical and computer engineering at UCSB, has reported the first-ever experimental observation of the spin Hall effect. The discovery, announced during November 2004 in Science (www.scienceexpress.org), has a wide range of possible uses in electronics and computing.
The Hall effect, named after American physicist Edwin Hall, who discovered it in 1879, occurs when an electric current flows through a conductor in a magnetic field, creating a measurable transverse voltage. The magnetic field creates the effect by exerting a force on the moving charge carriers and pushing them to one side of the conductor. The resulting buildup of charge at the side of the conductor ultimately balances this force induced by the magnetic field, producing a measurable voltage between opposite sides of the conductor. This classic Hall effect is widely used in today’s sensors and electronics. The spin Hall effect is a somewhat similar phenomenon in quantum physics, based on the angularmomentum property of electrons called “spin.” In analogy to the classic Hall effect, electrons with opposite spins (“spin-up” and “spin-down”) move toward opposite sides of a semiconductor wire, but in this case
without a magnetic field. The spin Hall effect generates a current across an applied electric field based on the electrons’ spin rather than their charge.
hours, requiring the researchers to carefully control the laboratory environment and the experimental conditions for data collection.
The spin Hall effect was predicted in 1971 by Russian physicists M.I. D’yakonov and V. I. Perel, but for 33 years it defied experimental detection. Awschalom and his graduate students Yuichiro Kato and Roberto Myers, along with Art Gossard, a professor of materials and electrical and computer
This discovery is particularly crucial to the development of electronspin-based technologies known as “spintronics.” Awschalom sees many potential applications, including sensing technologies, quantum computing, quantum communication and the shuttling of spin information in semiconductors. “The most exciting aspect of this finding is that you don’t know exactly where it’s going to lead,” he said. This research was funded in part by the Defense Advanced Research Projects Agency and the National Science Foundation.
engineering, first discovered the signatures of the spin Hall effect in semiconductor chips made from gallium arsenide (GaAs), which are similar to those used in cell phones. The also studied the effect in samples made from indium gallium arsenide (InGaAs). “We were initially skeptical when we first observed this in the laboratory,” said Awschalom. “We kept asking ourselves, ‘Why hadn’t anyone seen this earlier?’” Kato agrees: “We thought it was just noise at first, but the peaks kept reproducing as the scans were repeated.” The research team constructed a Kerr microscope with 1-micrometer resolution that allowed them to observe regions of electrons with opposite spins accumulated along the edges of the semiconductor chips. Some of the experiments carried out at UCSB ran for nearly 30 continuous
David Awschalom Gets 2005 Oliver E. Buckley Prize In recognition of his leading role in research that has led to discoveries such as that of the spin Hall effect, David D. Awschalom was recently awarded the 2005 Oliver E. Buckley Prize. The award, given annually by the American Physical Society, cited Awschalom for his fundamental contributions to experimental studies of quantum spin dynamics and spin coherence in condensed matter systems. Awschalom is professor of physics and electrical and computer engineering at UCSB and leads the university’s Center for Spintronics and Quantum Computation. He is also associate scientific director of the California NanoSystems Institute. The Buckley Prize recognizes and encourages outstanding theoretical or experimental contributions to condensed matter physics. Endowed in 1952 by AT&T Bell Laboratories (now Lucent Technologies) to recognize outstanding scientific work, it is named in memory of Oliver E. Buckley, a past president of Bell Labs. Only 70 other scientists have received the award, 13 of whom have gone on to receive the Nobel Prize.
News and Events from the Engineering and the Sciences at UC Santa Barbara their blood, which is affected by cycles of eating patterns, exercise, stress, sleep, hormones, and a host of other factors.
Awschalom and his research group at UCSB have pioneered new experimental techniques that led to the discovery of long-lived electron spin lifetimes and coherence in semiconductors and nanostructures. They recently demonstrated allelectrical generation and manipulation of both electron and nuclear spins in prototype solid state devices. This work opens the door to new opportunities for research and technology in the emerging fields of semiconductor spintronics and quantum computation. The Spintronics Center, headed by Awschalom, is affiliated with the California NanoSystems Institute, which is one of four California Institutes for Science and Innovation, supported by the state and private industry, and established in 2000. Engineering Theory Used to Ease Impact of Diabetes UCSB’s College of Engineering and the Santa Barbara-based Sansum Diabetes Research Institute have received $600,000 in federal grants to collaborate on research aimed at optimizing insulin regulation in patients with diabetes. The grants, awarded by the National Institutes of Health, are funding a twoyear project that will apply engineering theory to develop a mathematical description of the natural blood glucose cycle. People with insulindependent (type 1) diabetes take insulin throughout the day to regulate the amount of glucose, or sugar, in
The potential advantage to people with diabetes is simple: By better understanding these factors, the blood glucose levels can be more precisely regulated, thus reducing the impact and risks of diabetes to patients. The goal of the project is to create a model that will optimize the timing and dose of insulin delivery based on a patient’s unique response to insulin. The model will be tested in both computer simulations and in clinical studies with people with type 1 diabetes. The two principal investigators, Francis J. Doyle III, PhD, and Lois Jovanovic, M.D., offer a combination of expertise in systems engineering, endocrinology, and clinical work. Doyle is the Duncan and Suzanne Mellichamp Chair in Process Control at UCSB. He is also a professor in the Department of Chemical Engineering and holds a joint appointment in the Biomolecular Science and Engineering Program. Jovanovic is Director and Chief Scientific Officer of Sansum Diabetes Research Institute. She is also adjunct professor of biomedical science and engineering, at UCSB and clinical professor of medicine at the University of Southern California. Stress and UTIs Urinary tract infections are responsible for more than 9 million doctor visits a year. UCSB scientists have recently shown how the risk of UTIs can be affected by factors such as oxidative stress, heat shock and high pH. Writing in the November 19, 2004, issue of the journal Molecular Cell, researchers associated with the Department of Molecular Cellular and Developmental Biology describe how E. coli bacteria, which cause about 80 percent of human UTIs, migrate from their normal home in the bowel and colonize the urinary tract. The scientists – Aaron D. Hernday, Bruce A. Braaten, Gina Broitman-
Maduro, Patrick Engelberts and David A. Low – studied how the expression of hair-like cell surface structures – called “pili” – on the surface of the E. coli cells are controlled by environmental conditions. Pili play an important role in the adherence of the cells to the urinary tract, and hence in their ability to cause infections. If the cells cannot stick to the sides of the urinary tract and colonize, then they wash out, and no infection occurs. Certain stressful conditions can influence the genetic “switch” that causes the bacteria to be covered in pili. The study shows a mechanism by which a sensor called Cpx detects stressful environmental conditions and sends a signal to turn the switch off. This response may be important in allowing bacteria to avoid stressful environments.
News and Events from the Engineering and the Sciences at UC Santa Barbara A Living Nanoscale Necklace A team of UCSB researchers in physics and biology has made a discovery at the nanoscale level that could be crucial to the production of miniaturized materials. Dubbed a “living necklace,” the finding was completely unexpected. This discovery could influence the development of vehicles for chemical, drug and gene delivery, enzyme encapsulation systems and biosensors and circuitry components, as well as templates for nanosized wires and optical materials. The findings are reported in the November 16, 2004, issue of the Proceedings of the National Academy of Sciences. The team included Cyrus Safinya, a professor of materials and physics and faculty member of the Biomolecular Science & Engineering Program, Leslie Wilson, a professor of biochemistry in the Department of Molecular, Cellular and Developmental Biology, and researchers Daniel Needleman, Uri Raviv, Miguel Ojeda-Lopez and Herbert Miller. They performed their work with synchrotron x-ray scattering techniques at the Stanford Synchrotron Radiation Laboratory and with sophisticated electron and optical microscopy at UCSB. The scientists studied microtubules from bovine brain tissue to learn more about the mechanisms responsible for their assembly and shape. Microtubules are nanometer-scale hollow cylinders derived from cell cytoskeleton. In an organism, microtubules and their assembled structures are critical components in a broad range of cell functions—from providing tracks for the transport of cargo to forming the spindle structure in cell division. Their functions include the transport of neurotransmitters in neurons. The mechanism of their assembly within an organism has been poorly understood. The researchers discovered a new type of higher-order assembly of microtubules. Positively-charged large, linear molecules resulted in a tightly-bundled hexagonal grouping of microtubules – a result that was predicted. But, unexpectedly, the scientists found that small,
Researchers have discovered linear, branched, and loop-shaed necklaces of microtubules.
spherical divalent cations caused the microtubules to assemble into “necklaces” of distinct linear, branched and loop-shaped varieties. The researchers believe the living necklace phase is the first experimental realization of a new type of membrane in which the long microtubule molecules are oriented in the same direction but can diffuse within the living membrane. The scientists foresee applications based on both the tight bundle and living necklace phases. For example, metallization of necklace bundles with different sizes and shapes would produce nanomaterials with controlled optical properties. The assemblies could potentially be used as drug or gene carriers, with each nanotube containing a distinct chemical.
LOCATION, LOCATION, LOCATION As geographic information systems put more data on the map, social sciences are discovering the power of place as an analytical tool.
here? It is such a basic question that one might think scientists in all disciplines would be asking it. It’s fundamental to the science of geography, but elsewhere, especially in the social sciences, researchers have often ignored the value of location as a means of discovery – what UCSB geography professor Michael Goodchild calls the “spatial lens.”
Maps have long been used everywhere to describe places, illustrate trends and, of course, to get from here to there. The use of place not just to show data but to shed light on underlying causes is something newer and not yet so universal. But it’s advancing fast, helped along by UCSB research and by converging technologies: Satellites, wireless telecommunications, computers and the software that puts them all together, GIS. GIS (for “geographic information systems”) is the digital answer to the printed map. While the map can present only as much information as can be displayed on a sheet of paper, GIS has virtually unlimited capacity to show the data specific to a given place. It can also combine different “layers” of data to meet a researcher’s needs. Population density, crime rates, household income and education levels, average July temperature, elevation – the list of potential layers is limited only by the information available in the system. The mix can also include real-time data, such as the movements of people, machines or wildlife, from the Global Positioning System (GPS). So GIS is a “map” that not only can adapt to the choice of information desired, but also can adapt as the information itself changes over time.
Space, Time and Science
Government, geographers and businesses caught on to the potential of GIS some time ago. (Among other things, it’s a great way to spot and sort potential customers). Other social sciences such as sociology, political science, economics, demographics and anthropology have been slower to adopt it as a tool, say Goodchild and Professor Keith Clarke, chair of the UCSB Geography Department. “Spatial analytic techniques are very powerful, but so far only geographers have been interested in them,” Clarke says. One reason, Goodchild suggests, is that place-specific analysis goes against the scientists’ desire to find general rules that transcend particular conditions. “The trend in science has been to remove space and time,” says Goodchild. “What we seek is general, not tied to a specific location or a point in time.” Earlier attempts to use geographic factors such as climate to explain human behavior also were not up to modern scientific standards. Now, though, the ability of computers to collect, integrate and analyze a vast body of location-specific data has shown the way to a more sophisticated, scientifically valid use of place. It’s the use of location “not so much as an explanatory variable,” says Goodchild, but as context. Rather than being a causal factor by itself, he says, location “helps identify other causes” that analysis would otherwise miss. It’s especially good for teasing out the story behind residuals, when observed data deviates significantly from expected values. “If I observe that the biggest residuals in a nation-side study of urban areas are in the Front Range of the Rockies, that may suggest to me that the missing factor might have been elevation, since Denver is among the highest cities in the U.S.,” Goodchild says. Continued on page 21
Tom Pingel, a UCSB PhD student in geography, using the wearable GIS technology in the field. He is the author of the software running on the devices.
â€œThe trend in science has been to remove space and time," says Professor Michael Goodchild.
THE UV LAGOON Where Nanotech Meets Biology... Pioneering the practice of ecotechnology, engineers and marine scientists work with light and chemical signals to help restore the coral reef environment.
ost people who have some acquaintance with new science hear “nanotechnology” and probably think small – really small. That’s understandable, since nanotech is the science of manipulating matter at the atomic or molecular level, where distance is measured in billionths of a meter. It would seem, too, that the experimental subjects in this realm are too miniscule to see, hear or feel. But the paths of this technology can take surprising turns to the large-scale, the low-tech and even the do-it-yourself. So it is that scientists from the California NanoSystems Institute (CNSI), a research-and-development program run by UCSB and UCLA, are working with marine biologists in that biggest of labs, the Pacific Ocean, on the problem of how to regenerate damaged undersea environments, especially coral reefs. Their tool kit is eclectic. Ultraviolet light-emitting diodes, red alga and bathtub caulk have all been part of the experimental mix. Evelyn Hu, co-director of the CNSI and a professor of electrical engineering and materials at UCSB, says nanotechnology makes is possible “to create not only new materials but also a whole variety of new environments.” For the past two years, she and other scientists from CNSI and UCSB’s Marine Science Institute have been working under a $1.2 million grant from the W.M. Keck Foundation to put nanotech to work in real-world – in this case, underwater – ecosystems.
Night Lights for Fish The nature of this new interdisciplinary frontier, called ecotechnology, can be summed up by a story of light cones. These are LED-studded cylinders, looking something like chubby bottlebrushes, used to test how fish larvae respond to nighttime beacons of light at different wavelengths. Hu brings out one of these to show a visitor at her office: It is crusted with sea salt and slathered with hardware-store caulking. But it also holds some advanced electronics, specifically the gallium nitride LEDs that emit high-frequency colors such as white, blue and ultraviolet. If it looks less than elegant, it has been effective. During the summer of 2003, researchers deployed light cones with different wavelengths in a South Pacific lagoon. In the process, Hu and other scientists on the project learned not only how light lures fish but also how to deal with practical problems such as corrosion and salt water deposits. How did anyone get the idea of lighting up lagoons in the first place? The answer lies in the convergence of science and engineering disciplines, a trend that is well advanced at UCSB. Hu says this experiment grew out of discussions she had with Russ Schmitt and Sally Holbrook, professors of ecology, evolution and marine biology. Schmitt and Holbrook were doing research on population dynamics and species diversity in marine communities. Hu was intrigued with possible uses for new surfaces and semiconductors emerging from nanotech research. She and Schmitt developed the idea of using LEDs made from gallium nitride to attract larval fish to suitable reef habitats. Gallium nitride, unlike older semiconductors, is capable of emitting bright white, blue and ultraviolet light at low power. The ideas for using gallium nitride came to mind pretty naturally, since UCSB is home to the leading academic research into this compound and gallium nitride expert Steven DenBaars, a materials professor, is involved in the ecotechnology program.
What works for coral works for chips.
Saving an Experiment Hu knew that low-frequency light (such as red, yellow and green) is quickly absorbed by water and would not be visible to fish beyond a very short distance. But higher-frequency light (white, blue and especially UV) travels further. It would be capable of drawing fish from a considerable distance, as long as the fish were attracted to it. And if these light lures could be shown to work, they might play an important role in regenerating fish populations.
Ultimately, the field test in Moorea can be seen as an early step, at a large scale, toward true nano-scale uses for gallium nitride. While researchers in the lab are finding new ways to grow the semiconductor in nanowire form (as was announced recently by UC Berkeley), scientists and engineers in the field, typified by the UCSB team, are showing how such breakthroughs can change our environment and our lives.
That line of thought led ecotech researchers to the field station in Moorea, an island not far from Tahiti in French Polynesia. Working in a tropical paradise has one disadvantage – a shortage of sophisticated spare parts. So the researchers had to improvise, or else, when the salt water started corroding the electrical contacts. “You know you have to solve the problem or your experiment is gone for a year,” Hu says. They made do with what they could find at the local hardware store – bathtub caulk, as much as they could buy. It worked. The experiment went forward, and the team found that larval fish were drawn to the cones with the highest-frequency light, ultraviolet, more than those beaming blue or yellow.
Nanotechnology is also about surfaces and structures, living and inorganic. That leads to more opportunities for cross-disciplinary work. Dan Morse, a UCSB professor of molecular genetics and biochemistry, has been collaborating for the past decade with colleagues in engineering, physics and chemistry on processes such as biomineralization – how organisms make bones, teeth, shells and the coral skeletons. The same line of inquiry, he says, has charted “new routes to semiconductor fabrication.” What works for coral, in other words, works for chips.
This finding points to techniques for rebuilding fish populations in reefs damaged by pollution or misuse. The feat of operating LED lures under five feet of salt water offers other possibilities. These include the use of tiny electronic devices such as sensors and cameras to monitor and control biological processes in the ocean – or in another saline environment, the human body.
Engineering a Home for Coral
Morse and his wife Aileen, an associate at UCSB’s Marine Biotechnology Center, are working with Hu and others on another Keck-supported project focused on reef ecology. This one probes the chemical cues that lead coral larvae to settle on a surface and calcify, building up the structures that provide a haven for so many other species. Red algae emit the needed chemical signal, while the larvae crawl over the surface of the algae to find a place to call home.
Nighttime beacons containing LED-studded cylinders that emit light at different wavelengths were placed on the South Pacific lagoon floor to test how fish larvae responded25 to the different emissions.
The Morses have been able to attract coral by grinding up algae and putting the chemical inducer on glass beads. Now Daniel Morse says they are now working with Hu and Matt Tirrell, dean of the UCSB College of Engineering, who can bring their material-science background to bear on the quest for the ideal coral digs. Morse says he’s tapping Hu’s knowledge of semiconductor nano-fabrication and Tirrell’s expertise in the surface attachment of biological molecules. As Hu notes, “We’ve been successful in using techniques for the making of silicon wafers to deposit inducers on surfaces.”
No Scientific Silos The ecotechnology team is a study in the sharing of knowledge across the disciplines. Along with Hu, Tirrell, Schmitt, Holbrook, DenBaars and the Morses, it includes Alison Butler, professor of chemistry and biochemistry, materials professor David R. Clarke and Kimberly Turner, assistant professor of mechanical engineering. Also in the program are Steven Gaines, professor of ecology and director of the Marine Science Institute, and Andrew Brooks, an associate at UCSB’s Coastal Research Center. Such collaboration is common at UCSB – so prevalent that people on campus might forget how rare it is in the wider academic world. Dan Morse, who taught microbiology and molecular genetics at Harvard Medical School before coming to Santa Barbara, says UCSB is unusual among universities. When he speaks in the U.S. and abroad about this interdepartmental research, he says he’s often approached by professors, students and administrators “who say they have never heard of things being done in this way, and who would like to do the same interdisciplinary things at their institutions.” It may help that the ocean environment is hard to ignore at Santa Barbara, where engineers work a stone’s throw from the sea and the 1969 oil spill is a pivotal event in local history.
It’s a synergy that works both for the scientists and for the fish. For whatever reason, the university has long rejected the idea of leaving marine biology solely to the biologists, or of ignoring what electrical engineers might be able to do to protect and restore the environment. The UV lagoon in the South Pacific is one venue, among many, in which the sciences get together and find sometimes surprising ways to apply their widely differing types of knowledge. It’s a synergy that works both for the scientists and, as we’ve seen, for the fish.
Continued from page 16
Software for Data Explorers
Goodchild is principal investigator of the UCSB-based Center for Spatially Integrated Social Science (CSISS), a program to create tools for spatial analysis and to promote their use. Started in 1999 with funding from the National Science Foundation, CSISS holds summer workshops on spatial social science, brings specialists together to apply spatial methods to major social issues, disseminates best-practice examples and develops software to tap the analytic potential of GIS. The latest CSISS software package is GeoDa, from a team led by Luc Anselin at the University of Illinois. It combines statistical analysis and mapping so that users can spot significant geographic patterns -- such as which neighborhoods have a crime rate more than one standard deviation above the regional mean. And it’s a tool for exploratory data analysis. The same information can be displayed on a screen in different forms, such as a map, table and histogram; when the user changes one of these, the others change with it. Where does all this exploration lead? The potential destinations are as varied as the supply of data, which is growing dramatically. Using traditional public sources such as the Census, a program such as GeoDa can lead to new insights in political science, criminology and economics, to name just a few disciplines. It gives researchers a way to try out theories that, for lack of enough data and processing power, have not been tested. For instance, Goodchild says computerized spatial analysis based on GIS can gauge the impact of distance decay, the principle that human interaction declines in an often predictable way with distance. Researchers now have the ability to see how the population density of a city, for instance, might affect crime patterns and other phenomena.
This new processing power is arriving as a surge of new data is being made available from private-sector sources and GPS. The ability of satellites to track movements of just a few feet, and then to transmit that information to computers running GIS, opens up a whole new field of data: Not just points but tracks as well. With the help of people who agree to carry tracking devices, researchers now can analyze commuting patterns and other travel in minute detail. Adding other types of data, they can
note the different patterns of tightly defined demographic groups, such as single parents and employed middle-aged males in a particular city.
Into the Present, into the Field
The next step in GIS is to perform all this analysis as the data is being collected, so that observers can not only record new information but process it almost immediately. That’s the mission of another UCSB research program, Project Battuta, led by Goodchild and Clarke, (they are joined by a team from Iowa State University, led by professors Sarah M. Nusser in Statistics and Leslie L. Miller in Computer Science). Project Battuta, named after the 14th Century Moroccan traveler and chronicler Ibn Battuta, weds GPS and GIS with the wireless Internet to bring both data and analysis into real time – and out of the lab. Field observers use handheld and wearable devices to gather and receive data via WiFi. The information includes their precise location, determined by GPS, as well as any data they enter at that spot. This can be demographic data, like the household facts recorded in a census. It can also be disease or ecological data – or both, in the case of one of Goodchild’s students, who has been using Battuta tools to track vectors for the West Nile virus by mapping crows and jays in relation to their natural habitats. Clarke, responsible for developing the Battuta hardware, calls it “a complete computer system entirely contained within clothing,” with the output on a projector screen attached to the field researcher’s eyeglasses. “The idea was that we would bring out maps and images, place you on them, rotate them according to your position, pan and zoom,” he says. “You can see yourself on the map as a moving dot,” he adds, with the view either from straight up or at an angle. The researcher thus becomes a bit like Ibn Battuta himself, who helped create the science of geography by recording his 22 years of travel throughout the Muslim world. The pioneers at the interface of space, computer and telecom technologies are similarly advancing science by chronicling where they are and what they see. Their medium is software, rather than paper and ink, and their tools are much more powerful. But they’re after the same form of knowledge – the nature of a place, what makes it unique and also what it tells us about the wider human and natural worlds.
POWER A century after Einstein’s photon and 50 years after the invention of the first practical device to draw electricity from sunlight, two Nobel laureates at UCSB are pushing photovoltaics forward with research and a video project.
ome anniversaries call for a party. For physics professors Walter Kohn and Alan Heeger, the anniversaries of the solar cell and Einstein’s photon theory of light are the occasion for something more ambitious – an outreach program for students, teachers, policy-makers and the public. At its heart is a planned documentary on the past, present and future of solar electric power. Kohn, who was awarded the Nobel Prize in Chemistry in 1998 for his seminal work on the electronic structure of materials, is the executive producer for the project. Heeger, whose 2000 Nobel in Chemistry recognized his role in the discovery of conductive polymers – plastics that have properties of metals and semiconductors – is on the project’s board of scientific experts, along with UCSB Physics Chair James Allen and Stanford University Physics Professor Z. X. Shen. Their mission, as Kohn explains, is to tell a “kind of morality tale” about how science works and, in particular, why solar electricity is a scientific project whose time has come. “We use these anniversaries to provide a case history of how science, beginning with the most fundamental questions – the nature of light, the quantization of light – evolved into another stage, in which theoretical and materials science had advanced to where it could produce a practical solar cell,” Kohn says. Then they will turn to the future and explain how solar energy will help the world cope with what Kohn calls “a whopping global energy problem in 20 or 30 years.”
Kohn has lined up the services of producer/director David Kennard, whose credits include such major series as “Cosmos” with Carl Sagan, “The Ascent of Man” with J. Bronowski and “Unforgivable?” with The Dalai Lama. The centerpiece of the project will be a 50-minute documentary titled “Electricity from Sunlight: A Century Since Einstein’s Photon, Half a Century of Modern Solar Electricity.” It will be filmed in the U.S. and abroad, featuring interviews with scientists and depictions of photovoltaics in action. Another video, 20 minutes long, will be shot to present “more advanced photovoltaic science for classroom use,” Kohn says. He expects to distribute 15,000 DVD copies to high schools, community colleges, colleges, universities and science museums. A Web site with live streaming video is also in the works, along with plans to submit the video for airing on public television and the Discovery Channel. The project’s total production budget is about $500,000, of which about half has been raised. “Additional support from private donors and private and corporate foundations will be gratefully acknowledged,” Kohn says. The dual anniversary that the Kohn wants to commemorate with his film refers to two breakthroughs, one in theory and the other in application. The first was the publication, in 1905, of Einstein’s paper introducing the concept that light acted as discrete bundles of energy – photons – as well as waves. The second was the 1954 invention by Bell
Laboratories researchers of the first practical silicon solar cell, which converted photons from sunlight directly into electrical energy. Kohn now sees solar electricity at another pivotal point, where it is ready to take off as one of the world’s primary sources of power. Its role up to now has been significant, especially in underdeveloped regions where solar cells help make up for the lack of a power grid. But converging economic trends – solar electricity is getting cheaper to produce while fossil-fuel prices are rising – have been pushing photovoltaics into the energy mainstream. “Solar energy is quite realistically estimated, in two or three decades, to contribute perhaps something in the vicinity of 25% of total electricity consumption,” he says.
"Solar energy is estimated, in two or three decades, to contribute perhaps 25% of total electricity," says Kohn. One reason for solar power’s rise is the development of new technology that brings down the per-watt cost. One of the leaders in this area, on both the theory and practice sides, is Heeger. His research in semiconductors and metallic polymers not only earned him his Nobel prize but also helped spark the creation of new materials for photovoltaics. He is currently working in conjunction with Lowell, Mass.-based Konarka Technologies (where he is a director and the firm’s chief scientist) to develop low-cost solar cells using semiconducting polymers that can be molded like plastics and printed onto flexible surfaces. “They are, in fact, inks with functionality,” he says. Heeger says these plastics are not currently as efficient as silicon solar cells. The most efficient commercial silicon cells convert more than 30% of light energy into electric power. The materials Heeger is working currently to develop convert only about 5%. “We see many opportunities for improvement” Heeger says. “If we got 10%, it would be a revolution.” Solar cells based upon conducting polymers are potentially more cost-effective than silicon cells because they can be produced more cheaply per unit of area. Heeger explains: “Area and cost are the two issues here. If the cost is sufficiently low, implementing large areas would be cost effective.” He hopes to see “plastic” solar cells reach commercial viability within two years. “The experiments done so far on these polymer photovoltaic cells are good enough to give us confidence that they could be used economically on roof tops; that’s the Holy Grail.” In these ways, Kohn and Heeger are covering the bases of solar-energy science – research, development and teaching, to students at UCSB and to both the wider public and policy makers. Their project also goes beyond the specific cause of promoting photovoltaics, as important as that may be. Kohn says he hopes the outreach makes the case not only for solar electricity but for science as a career: “We want to motivate young people and show them what wonderful opportunities science can bring.” Movie directors – and Nobel Laureates – Alan Heeger and Walter Kohn
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