Convergence - Issue 9

The Magazine of Engineering and the Sciences at UC Santa Barbara

FALL 2007, NINE

Energy:Plastic PowerClimate CluesMore from LessHydrogen HighwayControl Freaks

All EnergyFor the first time, we are devoting the bulk of an issue of Convergence to a single topic. We’re doing so because we believe energy efficiency is of great interest to you, our readers, and because we want to showcase the work UCSB is doing in the field.

You might not have thought of UCSB as an intellectual and research powerhouse in the field of energy. But in fact, we are engaged in a significant number of projects and initiatives related to this critical topic, involving professors and students in both engineering and the sciences.

It’s largely due to our highly interdisciplinary and entrepreneurial culture here at UCSB that so many innovations and discoveries are being made in a growing range of areas critical to the advancement of society, including energy.

Evelyn HuCo-Director, California NanoSystems Institute

Matthew TirrellDean, College of Engineering

Steven GainesActing Dean of Mathematical, Life and Physical Sciences, College of Letters & Science

Letter From the Deans

Cover Story: Plastic Power

Making photovoltaics at least as cheap as the grid.

Shorts... Have you heard?

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16 Which Way to the Hydrogen Highway?

23What is This?

More from LessA look at our energy future.

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2It may be the fuel of the future, but it’s a challenge to store and costly to generate.

CONTENTS fall 2007, nine

CONVERGENCE T he Magazine of Engineer ing and the Sciences at UC Santa Bar bara

question & answer:

6 Matthew TirrellThe Dean of the College of Engineering talks about energy.

10 Climate Cues from the Deep

David Lea probes the tropical ocean floor to understand global cooling in the past and warming in the present.

Control FreaksEngineers take embedded computing to new levels of precision in their quest for greater efficiency.

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Nobel laureate Alan J. Heeger (right) and Professor Guillermo Bazan lead research groups in UCSB's Center for Polymers and Organic Solids.

Mix sunlight with brainpower and you will get a form of energy that is cheap, inexhaustible, good for America and good for the planet. Such has been the dream, for several decades, of scientists, engineers, entrepreneurs and activists trying to bring photovoltaics – the generation of electric power directly from sunlight – into the economic mainstream. That goal may finally be in sight, and UC Santa Barbara researchers are working to bring it even closer.

Their most recent breakthrough, announced in July 2007 in the journal Science, was the development of tandem organic solar cells that convert more than 6% of the energy from sunlight into electricity. This conversion ratio is well below that of the most efficient silicon cells, which can capture about 25% of light energy. But it’s a big advance for organic cells, whose earlier efficiency topped out at about 5%. More important, the Science paper introduced a new architecture

for the multi-layer tandem cell, an advance that will lead to higher conversion efficiencies in the future.

At UC Santa Barbara, the nucleus of the photovoltaic effort is the Center for Polymers and Organic Solids (CPOS), where research groups of Nobel laureate Alan J. Heeger, Kwanghee Lee, Guillermo Bazan and other scientists are developing solar cells that can be painted, printed, mass-produced like photographic film or even woven into clothing. Technically speaking, they are bulk

heterojunction cells based on phase-separated blends of polymer semiconductors and globe-shaped carbon

structures called fullerenes. In simpler terms, they are power-generating plastic. Heeger says Lee’s work at CPOS “has resulted in the creation of a new architecture for our solar cells that yields the best performance obtained to date – a truly important step forward. This new architecture for the multi-layer tandem cell will lead to higher conversion efficiencies in the future.”

Paintable Photovoltaics Unlike the familiar rigid silicon cells that provide power for spacecraft and calculators, the plastic cells are thin, flexible films. Heeger says they can be applied like paint and literally printed like ink, using “standard printing tools.” Though they currently lag behind silicon in raw efficiency – the percentage of light converted to electricity – they are potentially much cheaper than silicon to produce and install.

The development of plastic photovoltaics is a “worldwide effort,” says Heeger, a professor of physics and materials who shared the 2000 Nobel Prize in chemistry for discovering polymers that conduct electricity. (He is also chief scientist and co-founder of a company, Konarka Technologies, working to commercialize the new solar-cell technology as “Power Plastic.”) The new tandem solar cells were developed by Lee and Heeger along with Jin Young Kim at Gwangju Institute of Science and Technology in Korea and Nelson Coates, Daniel Moses, Thuc-Quyen Nguyen and Mark Dante of CPOS.

The cells’ leap in efficiency comes from the use of two layers of photovoltaic material that are sensitive to different parts of the spectrum. Together, they absorb light (and energy) from a wider range of wavelengths than a single cell would. They are connected by a transparent layer of titanium oxide that serves as a conductor, collecting the electron flow generated by each of the cells.

In another approach to the problem of squeezing more electricity out of plastic, CPOS scientists have also seen good results from tweaking the solution that is used to coat films with photovoltaic materials. Recently they found that adding the chemical octanedithiol to the solvent toluene significantly raises the solar cell conversion efficiency. The discovery was due mostly to luck. Bazan, a professor of materials and chemisty and (along with Heeger) co-director of CPOS, says it came about when researchers were trying to incorporate gold nanoparticles into solar cells (as a way of amplifying light) and used the alkyl thiols to keep the gold from clumping. They realized that the process worked well without the gold – though Bazan says they’re not sure why. “Somehow, if you have [alkane dithiol] in solution, it allows the system to self-organize in a way that gives very good absorption of light, charge generation and charge collection,” he says.

Researchers at the Center for Polymers and Organic Solids are finding ways to reduce the cost of solar cells. Their goal: to make photovoltaics at least as cheap as the grid.

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The researchers are now trying to figure out just what makes this additive work, so that the process might be refined and improved further. “We’ve made the most efficient solar cells in the world,” says Bazan, “but this has opened up scientific issues.”

Herding ElectronsTo get a clearer picture of how scientists are trying to raise the efficiency of plastic photovoltaics to a cost-effective level, it’s helpful to look at just how photovoltaics work.

Solar cells produce electricity by transferring energy from photons to electrons in a semiconductor, such as silicon or (in plastic photovoltaics) a semiconducting organic polymer. In organic cells, the energized, negatively charged electrons jump from the light-absorbing polymer to another material. The polymer is left positively charged or, in physics terminology, “bearing a hole.” The resulting current is picked up by electrodes.

In conventional silicon solar cells, the current is produced at the junction between two layers of silicon that are “doped” with chemicals such as boron, arsenic or phosphorus to produce dissimilar charges (hence the term “heterojunction”). These charges are what pull electrons from one layer to the other. In a plastic solar cell, the polymers that absorb the photon energy and the fullerenes that attract the energized electrons are not separated into smooth layers but are melded together – it’s a “bulk” rather than “bi-layer” heterojunction. (The term “fullerene” is a tribute to R. Buckminster Fuller, the visionary architect who popularized the geodesic dome. Carbon atoms in fullerenes are arranged in geodesic patterns – another name for these structures is “buckyballs.”)

The challenge in plastic photovoltaics, says Bazan, is to get the electrons and holes moving toward the electrodes so that they can produce useful electricity. The structure of organic polymer solar cells makes this more complicated than in common silicon models. The fullerenes and polymers must be packed together

to move charges between them, since electron and hole transport are less efficient in these materials than in silicon. At the same time, it’s difficult to keep the electrons from breaking ranks and popping into the nearest holes. It is a race to the electrodes before electron and holes recombine and turn the original energy of the photon into heat.

Grid Parity in 2015? The crucial goal in the development of solar power is to reach “grid parity,” the point at which price of electric-ity from solar cells is no more than that of power from the local utility and its conventional sources. The federal government in its “Solar America Initiative” has set a target of grid parity by 2015. Many factors could affect that timetable, and some (like the price of oil, coal, natural gas and power generation) are beyond the control of solar-energy scientists. But researchers can improve solar power’s chances by continuing to whittle down its per-watt price. Increasing cell efficiency is part of this effort. So is lowering the manufacturing and installation costs of cells, along with cutting replacement cost by making cells more durable.

Efficiency numbers and other details of solar-cell technology are a distant concern to most potential customers, who really just want to know if they can buy this ultimate in renewable energy at a price they can afford. On that score, the mission of researchers is to enable most consumers to get a solar experience now available only to solar aficionados who are willing to pay the higher cost today as an investment in the future.

Heeger has a photovoltaic system installed at his home, and he knows first-hand that today’s solar systems work very well. “Silicon solar cells are wonderful technology,” he says. “When the sun comes up, my electric meter runs backwards.” But

this energy isn’t cheap. Heeger says, “It will take too long – eight to 10 years – to recoup that capital outlay. We really need something that is low-cost and generates over large areas.” Step by step, that vision of mass-market solar power is coming closer to reality as UCSB scientists come up with new designs and new concoctions to boost the power of plastic.

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“Silicon solar cells are wonderful technology,” Heeger says. “When the sun comes up, my electric meter runs backwards.”

UCSB's researchers have been able to develop solar cells that absorb photons from more of the sun's wavelength spectrum than did previous cells, creating the most efficient solar cells in the world.

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q u e s t i o n & a n s w e r:

matthew tirrell

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As this issue of Convergence makes clear, engineers and scientists at UC Santa Barbara are engaged in wide-ranging research related to energy – its sources, its environmental impact and its efficient use. Matt Tirrell, the Richard A. Auhll Professor and Dean of UCSB’s College of Engineering, recently sat down with the magazine’s senior writer, Tom Gray, to talk about UCSB’s important role as a source of new energy technology, now and in the future.

Convergence: Energy efficiency, conservation and alternative energy are hot topics these days, and a lot of research institutions would want to call themselves leaders in any of these areas. What makes UC Santa Barbara a leader?

Tirrell: Well, we’re trying to take a really sharp focus. And to be really specific, our skills and emphasis are not mainly on increasing the supply of energy. We’re talking about new technologies that deliver quality-of-life solutions by meeting people’s demand for energy while being more efficient about it. In other words, we’re after technologies that deliver results without wasting energy. So I’m differentiating our focus from research directly on environmental impacts, though there could be ramifications in the environment. I’m also not appealing specifically to human virtue. I’m not saying you should have a smaller car and make sure you recycle everything. That’s what I call conservation.

Convergence: Speaking of demand-side technology, what kind of start has been made in that direction at UCSB? What is going on now that points you toward new advances?

Tirrell: The biggest one, of course, is solid state lighting. Its entire rationale, more or less, is built around more efficient use of energy going into lighting. The second is a whole range of things that I call energy-efficient electronics, or new ways of doing computing. Most of the heat in computing is generated by pushing electrons through materials. But there are other ways of computing. Moving light through materials generates almost no heat. Flipping spins in materials – spintronics and quantum computation – generates almost no heat. There are big efforts in these areas at UCSB, and if they pan out, computing and other electronic functions will be much more energy efficient. Then there are bigger system-wide kinds of things. We have a group of people in electrical engineering working on lower power-consumption designs for chips. There are people in computer science who are using algorithms to try to make more energy-efficient networks so that a network has some intelligence; not every appliance or machine has to be on all the time; you can deploy the resources intelligently, when they are needed and you manage this using an innovative computer algorithm.

And, a group here has put forward a proposal for an engineering research center based on materials for transportation. This center would focus on a combination of things but mainly lightweight materials and high-temperature materials – such as high-temperature engine parts, so that engines could run hotter and therefore more efficiently. I think there’s a lot of power behind that initiative, coming out of our structural materials group and our high-temperature materials group. A lot of what we’re talking about here is based on materials science, in which UC Santa Barbara Engineering and Science is particularly strong.

Convergence: Speaking of materials science, how many of these efforts are essentially a re-branding of what UC Santa Barbara has been doing all along? What you’re talking about – spintronics, lightweight materials in aircraft engines, and so forth -- is well-established here. Is what you plan going forward any different from what you would be doing anyway?

Tirrell: Well, we have to certainly bring something substantial to the story in order to have any muscle, rather than just create something we haven’t done before. But I understand your point: What can be new about this? I think there can be lots of things. One is creating energy for the developing world. That might involve coupling more than one technology, like marrying our solar energy with our solid

An LED (Light Emitting Device) makes efficient use of energy.

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I’m a little baffled by certain things that are going on, like biofuels. I think we have plenty of stuff to burn for the foreseeable future, and I don’t really see a great advantage in creating more, given the adverse climate implications.

state lighting group. Think about what happened in Africa with telecommunications. They skipped the wired phase and have gone directly to wireless. We might be able to avoid building a lot of power plants in Africa. Instead, we might use technologies that marry solar with efficient delivery systems for lights and displays and so on. That’s the kind of thing that could happen as a result of the work we plan to do here.

Convergence: At UCSB, how much of this “marriage” between areas of technology is going on now, and how much do you want to push further?

Tirrell: I would like to push a lot of these things further. You know, people get grants for what they’re doing. Different people fund solid state lighting and organic

semiconductors. It’s not that these groups don’t want to work together towards these goals. If the right kind of funding became available, I’m sure they would. We would then generate more powerful collaborations on our campus.

Convergence: So you believe government and industry need to redirect some of their current funding?

Tirrell: I think there needs to be a much more astute direction. I’m a little baffled by certain things that are

going on, like biofuels. I think we have plenty of stuff to burn for the foreseeable future, and I don’t really see a great advantage in creating more, given the adverse climate implications. I guess I’m really trying to shine the spotlight back on the demand side rather than the supply side, and I think people are a little mixed up on what can produce really valuable returns on investment in the short term. For instance, the land mass that would have to be committed to growing the fuel that we need is huge.

Convergence: How much is politics interfering with funding decisions, and what could be done about that?

Tirrell: I suppose if I really knew what could be done about it, I would run for Senate rather than be a dean. But I don’t think there’s a chance that corn has anything to do

with our energy future, [though] maybe grass and cellulose and that sort of thing do. I understand that the American Physical Society has just commissioned a study headed by Burt Richter, a Nobel Prize winning physicist at Stanford, to analyze the kind of investment and return that could be expected from different technologies. I think we need more of that, and less politically-influenced discussion.

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Convergence: In terms of return, what is it the primary goal we should be seeking in energy research? Is it mainly climate-related now, or is it security related?

Tirrell: Well, I think all of those things are important for society at large. The thing I like about focusing on energy efficiency and technology is that it is indeed related to climate change. The 2006 Stern Review on the Economics of Climate Change says that a consistent reduction of 3% to 4 % a year in energy demand would essentially be consistent with getting carbon emission levels down to a safe level. But that’s not exactly the argument that I’m making. My argument is more that demand is growing and that it has to be met somehow – for example, in the developing world. And if we don’t think about technologies that do it, we really are going to have an energy crisis and possibly a social crisis. I’m trying to some extent to divorce what I’m saying from an ecological/environmental climate-change argument.

Convergence: Why would you want to do that? Is it because it’s less political?

Tirrell: Yes. I don’t want our research to have to rise or fall on people’s views about climate change. And I believe that a real hook on this issue for many people – those who are prepared to invest in new technologies – is that we’re not making arguments that are politically based but are talking about things that lead to new businesses, create jobs, create wealth and have a societal benefit economically.

Convergence: You mentioned earlier that you are not trying to appeal to human virtue. That raises the question of whether the goals you talk about are achievable without some kind of behavioral changes. How much can technology and the research you’re talking about solve the world’s energy problem, and how much of a push is needed from public policy, not just to change behavior but to encourage adoption of the new technology?

Tirrell: I personally believe that that would be a good idea – that some incentives and policies should be developed to promote the use of new technologies. But I’m guessing that this will be a lot easier once a few more technologies prove themselves, and there’s always the risk that less efficient technologies will get the most encouragement. Right now, with lighting for example, even as strong as the case for solid state lighting appears, there are people questioning whether it will be a practical part of the solution in your lifetime or mine. You know, Australia has banned the [incandescent] light bulb after some period of time. This is driving the use of compact fluorescents, and, you know, this will also drive a lot of new installations based on compact fluorescents, and a certain amount of capital investment is married to the idea of compact fluorescents. If that gets a leg up, fluorescents may be here for a long time and solid state lighting may have trouble competing with them. Even if solid state lighting is more efficient, which is indisputable, it would require another round of expensive capital investment.

Convergence: Here’s a historical question. Roughly 30 years ago, there was a huge level of concern about energy and much effort to achieve “energy independence,” but much of our effort back then seemed to do little good. What’s the danger of the same mistakes being made now? How are things different this time?

Tirrell: My gut feeling is that there’s not much danger of the same mistakes being made, but I’m having a little harder time coming up with a convincing answer to the second part of your question: What’s really different this time? I think more people are more afraid of the climate consequences. I think people thought we were running out of oil in the 70s. I don’t think they believe this now. The high price of oil right now is a demand-driven thing, not really a supply-driven kind of thing. Oil is available for at least 50 years. This is a long time in most people’s mind. It’s not going to be there forever, but the price is high now because we don’t have the refining capacity, people are driving more, they just want more of it, and it takes a lot to turn oil into gasoline.

Convergence: Looking ahead, do you foresee any breakthrough energy technology that will make a huge difference in energy efficiency, say, 10 years from now? Is it solid state lighting or something else?

Tirrell: I would say solid state lighting is definitely a part of it, and I think, really, on the alternative energy side, solar energy is the most important thing.

Convergence: How does hydrogen fit in?

Tirrell: Well, hydrogen is not an energy source but a strategy for transporting energy. So your question is really a question of what is best and most convenient to turn solar energy into – using it to produce hydrogen or to generate electricity directly, for instance. Of all the alternative energy sources, solar is by far the most important. There’s so much of it, and there are good ways to improve our efficiency in capturing it. A lot of the developments in solar will be based on materials science and chemistry, having to do with the structure of matter, the capture of solar energy and the efficiency of transformations that you can make and control. I have the highest hope by far for solar energy.

UC Santa Barbara’s David Lea probes the tropical ocean floor to understand global cooling in the past and warming in the present.

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H ow cold was it then? How hot is it now? Those questions, on which so much science (and politics)

depends, are less straightforward than they might sound. Take the fact that, according to the U.S. National Climate Data Center, the earth’s surface temperature averaged about 58°F in 2006, which was about one degree above the average for the 20th century. That number is high compared to the recent past, but what about more distant times? And what does it tell us, if anything, about what causes global warming or what the future might bring?

This is where paleoclimatologists such as David Lea come in. The MIT-trained Lea is a professor of Earth Science at UC Santa Barbara and leader in research on prehistoric global warming and cooling. His work has filled gaps in the long-term temperature record and has played a key role in setting the context for today’s observations and debates. It also sheds light on how climate change occurs and what we might expect in our own century.

Lea’s focus is on the record of climate change encoded in the chemical archive of tropical oceans. By measuring trace levels of magnesium in the shells of tiny marine organisms deposited on the seabed, he has been able to construct a record of water temperatures going back 1.4 million years. (See the sidebar on page 11, “Tracing Ancient Temperatures.”)

His most important discovery, announced in 2000, was that the water near the Equator in the eastern and western Pacific cooled significantly – by about 5° F – during ice ages. This was not what most scientists expected, says Lea: “Ten or 15 years ago, people would have been inclined to say the tropics then were about the same as they are now.” What made this data especially striking was the timing of the temperature change. Lea found that the cooling of tropical seas preceded the buildup of ice on land by about 3,000 years. This ran counter to the most popular idea of how ice ages occur – in a sequence that starts with slight variations in the earth’s angle toward the sun, followed by the advance of glaciers and further cooling from feedback effects, such as the reflection of solar energy from the spreading layer of snow and ice. Instead, the root cause of the cooling had to be something that preceded the glaciation, several thousand years before.

In other words, the “How cold was it?” question turned out to be complicated in its own way. Just when and where the cooling occurred made a crucial difference. Lea says his data from the equatorial Pacific got him thinking. “One of the ideas that really captured my imagination was that the tropics are very responsive to greenhouse gas abundance in the atmosphere.” (Evidence from ice core samples shows that the level of carbon dioxide, a greenhouse gas, fell before the last ice age). That insight led Lea to study the tropical oceans for clues into the impact that greenhouse gases are having on global climate today.

It is in the waters near the Equator that climate trends are most directly linked to global climate change, he says. The public may hear mainly about shrinking glaciers and sea ice in polar regions or heat waves and other extreme weather in the temperate zones, but Lea says the much less volatile tropical seas are the best places to look for evidence that the earth’s atmosphere, as a whole, is heating up. One reason is that large expanses of the equatorial Pacific and Indian oceans are essentially static. They have little of the weather patterns that would cause sharp changes in temperature by drawing in or pushing out the colder air and water from higher latitudes. They are far from human influences such as the local warming of urban “heat islands.” And as large, deep pools, they have great thermal inertia; it takes a lot of heating or cooling, over a long time, to change their temperature much. Lea and fellow researchers, including James Hansen at NASA’s Goddard Institute for Space Studies, say they have found a slow but significant rise in water temperature – just over one degree Fahrenheit over the past century – in these regions.

Lea says global temperatures are warmer today than at any time since the last ice age ended some 10,000 years ago. And they seem to be not far from their highs of the past one million years.

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So what about that big question, “How hot is it?” On the basis of recent data and the chemical record from tropical oceans, Lea says global temperatures are warmer today than at any time since the last ice age ended some 10,000 years ago. And they seem to be not far from their highs of the past 1 million years. Lea cautions that temperature records get increasingly uncertain with age; he notes that scientists’ recent estimates of ocean temperatures at the time of the dinosaurs range from 77° F to 104° F. And he says the ability of climatologists to predict what happens next is far from reliable – though that fact is less than reassuring. On the subject of sea levels he says, “My sense is that we’re

probably not going to see a rise of more than a meter in this century,” but he says scientists have already been surprised by the speed with which the Arctic sea ice is shrinking. Melting sea ice does not raise sea levels, but if ice on land melts sooner than expected, the rise in sea levels could also be faster and more destructive – and not without precedent: “We know, for example, that 125,000 years ago, sea level was four to six meters higher than it is today.”

Lea faces this uncertain future with a mix of optimism and concern. He believes that human activity now fuels global warming and that, by the same token, human ingenuity – including the energy efficiency and solar-power research being conducted at UCSB – is capable of solving the problem in the long run. “But to some extent we have to divide [our efforts] between the short term and the long term.” It will be some time until the needed technology comes of age, and in the meantime Lea says there’s no getting around the need to conserve. “We’re emitting, as a global community, 7 billion tons of carbon a year,” he says. “You don’t want to be too negative because it doesn’t inspire people, but you need to tell people that this is a serious problem.”

Tracing Ancient TemperaturesClimate change leaves records on both land and sea. Tree rings show variations in the amount of rain and snow. The temperature of long-ago rainwater is reflected in the proportion of oxygen and hydrogen isotopes in rock formations precipitated from water – such as stalactites and stalagmites in caves. In ocean environments, impurities in the fossilized calcite shells of organisms such as foraminifera (see photo on page 10) are clues to the temperature of the water at the time these tiny creatures lived. Lea measures one such trace element, magnesium, which precipitates in calcite at different levels depending on water temperature.

The amount of magnesium in the shells of foraminifera is very low. Each shell weighs about 10 micrograms, and the magnesium is only 0.25% of that. But Lea works with an apparatus, the inductively coupled plasma mass spectrometer, that is precise enough to detect differences in the level of magnesium corresponding to differences of 2° F (or roughly 1° C) in the temperature of the water when the shells were formed. His key findings on ancient tropical sea temperatures were based on samples taken from the sea floor at two widely separated sites in the Pacific Ocean, near the Galapagos Islands and northeast of New Guinea.

David Lea

More from LessCan society get through the 21st Century with its standard of living and the environment reasonably intact? The answer to that question depends greatly on energy – how it is produced and how it is used. Convergence asked experts at UC Santa Barbara for their view of the future, with a focus on the role of new technologies that can help us use energy more efficiently.

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Will LED’s Light the Way?

The future looks bright to advocates of solid state lighting, a technology in which semiconductors called light-emitting diodes (LEDs) take the place of incandescent or fluorescent bulbs. LEDs

are already common in cell phone displays, flat-panel TVs, traffic lights and control panels on consumer appliances. They are quickly taking over the flashlight market. Not so many years from now, they could be illuminating just about everything, from homes and offices to streets and stadiums.

That’s the scenario mapped out by engineers at UCSB’s Solid State Lighting and Energy Center (SSLEC), one of the world’s key sites for LED research. Led by UCSB Materials professors Shuji Nakamura (inventor of white, blue and green LEDs as well as the blue laser) and Steven DenBaars, SSLEC develops new LED technologies and works with companies to commercialize them. “A lot of excitement has occurred because the white LEDs we have developed are more efficient than fluorescent lighting and 10 times more efficient than incandescent,” says DenBaars. “I think within five years we could definitely be the dominant technology.”

The incandescent bulb, little changed in its basic design since Thomas Edison devised the first commercially practical electric light nearly 130 years ago, does seem to be on its way out. It turns only 1% to 4% of its electricity into light (much of the rest goes into heat), while fluorescents achieve efficiencies of up to 25% and LEDs can top 50%. It’s being pushed aside by the rising cost of electricity and promotion (by utilities and governments) of an affordable alternative, the compact fluorescent lamp (CFL). The real question now is what will take its place for the long term. LEDs are more energy efficient than CFLs – about three times more, DenBaars says – but they are also much more expensive. LED bulbs are now about 10 times as expensive as compact fluorescents with comparable light output.

At its current price of around $50, an LED that puts out the equivalent of a 60 watt incandescent would take about five years to return its cost in energy savings. “We need to get that [recovery period] down to something on the order of one year,” says DenBaars. But he says this shouldn’t be all that difficult for LEDs, if they behave as other semiconductors do. Like the fabrication of computer chips, the making of LEDs requires a big up-front investment in manufacturing technology. But once the expensive infrastructure is in place, LEDs can be produced in huge volume for little added cost. DenBaars says a new semiconductor typically falls 50% a year in price. If the

same happens for LEDs (and assuming that CFLs don’t fall almost as fast), they could well hit their competitive price point early in the next decade.

DenBaars, Nakamura and their colleagues at SSLEC are also trying to boost the LED revolution by making the devices more efficient, not just cheaper. Their near-term target is an LED that can turn at least 60% of its electricity into light; their ultimate goal is to raise the efficiency level to 80% or more. One thing holding them back from that goal is the relatively weak performance of green LEDs. White LED light is made up of combined hues from different semiconductors, and DenBaars says researchers so far have not been able to make a semiconductor that puts out green light as efficiently as red and blue LEDs can. “If we could develop a really efficient green LED, that would raise the

efficiency of white LEDs,” DenBaars says. “Then you could start talking about LEDs that are four to

five times more efficient than fluorescent.” According to the SSLEC, about 22%

of America’s total electrical output goes into lighting, so the potential

of these advanced LEDs is clear. A nationwide switch to these lights could have a huge impact on energy use and carbon output. If the people at SSLEC are right, it’s not far around the corner.

Toward Leaner Computing

The role of computers in the overall energy picture is

complex. As direct users of power, they are minor players. By

one U.S. Department of Energy estimate, about 3% of the electricity

used in buildings goes into computing. That’s far below the consumption for

lighting, appliances, electronics, refrigeration or space heating and cooling. On the other hand,

computers are crucial to energy efficiency and conservation. To cite just a few uses, they boost the fuel economy of cars and aircraft, manage power grids and, through the Internet, enable people to work together without the need for energy-burning travel. Researchers say computers could do even more energy-saving tasks if they could be made smaller, more rugged and more powerful. Tiny embedded computers in automobile engine blocks, for instance, could control fuel use more precisely than the devices now used with fuel injection and exhaust systems.

The challenge here is to make more efficient use of space as well as energy. Fred Chong, UCSB professor of computer science and head of the university’s computer engineering program, notes the shrinking of circuitry on computer chips is reaching its theoretical limits – at least until new technologies and architectures come along. “The reason we’re not using more energy [in computing] is not primarily because the world does not have more energy to give us,”

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Chong says. “It’s because heat limitations will not let us get more energy into that little chip.” One aspect of computing where energy efficiency could improve is in the internal power sources – the transformers that convert electricity from the grid into current for computing. “Because of other design constraints, computing devices are actually quite efficient,” Chong says. “What’s inefficient is the transformer. That’s what the computer industry is trying to force the [power source] manufacturers to fix.”

Chong sees new technologies on the way that “promise to revolutionize computing” by breaking the space constraints on chip design. One of these is the development of carbon nanotubes, which he calls “the wonder material of the new century,” with “very nice properties in terms of how small they are and how they conduct electricity.” But don’t expect most computers to use less power, he says. “You’re going to be designing chips that use about as much power, but we’re looking at putting more performance into that constraint.”

One new type of computing, still early in its experimental stage, can use less energy than the CMOS (complementary metal-oxide-semiconductor) technology in use today. This is quantum computing, which operates by switching the quantum states of particles rather than by moving electrons. “Quantum computing doesn’t fundamentally require energy dissipation,” says UCSB Physics Professor John Martinis. Classical CMOS computing uses energy and throws off heat, but quantum transitions conserve energy. If a particle goes from one state to another and back again, the net energy use is zero.

But the real payoff from quantum computing may come from its ability, at least in theory, to vastly expand processing power. Martinis, a superconductor specialist who has been working on quantum devices for several years, points out that the CMOS transistor has only two states, on and off – or 0 and 1. A quantum transistor has greater possibilities since in quantum theory a particle can be in two states at the same time. That allows parallel processing of many input states without requiring more hardware. Martinis suggests that quantum computing could even be used to build “less power-hungry classical computers” – similar to current models in their design, except at the level of the individual transistor. That goal, not to mention the prospect of wholly new computer design based on quantum theory, is still far off. Martinis and fellow researchers are still trying to build a quantum transistor integrated into a circuit capable of simple calculations. He says the state of quantum computing is where classical computing was in the early 1950s: “This is really long-term research, but it has important practical applications.”

If You Build It, Will They Buy?It takes more than new technology to create an energy-efficient future. Even the best science will have no impact unless it finds its way into widely adopted products. Innovations such as LED lamps, hybrid (or hydrogen) cars and solar cells all could have great benefits to human well-being and to the environment, but not if they remain niche-market items, bought only by the greenest among us. At

Continued on Page 28

Post-doctoral student Hisashi Masui, Professor Steen Denbaars, Professor Shuji Nakamura, and graduate student researcher Natalie Fellows

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It's two days packed with engaging keynote speakers, sessions highlighting exciting research at UC Santa Barbara, and details on how to work with the university and license our technology. The event also affords the opportunity to network with presenters and guests alike at an evening reception the first day, lunch on the second day, and breaks in between.

imagine most cars in the nation running on an energy source that’s carbon-free, produced entirely in the U.S. and as abundant as water. You wouldn’t be the first to have this vision. The dream of a hydrogen-based economy has been around as long as concerns about oil imports and global warming. And at least one technology that’s crucial to this dream, the hydrogen fuel cell, is already in use. So why isn’t America on the hydrogen highway now?

The answer, as with so many other energy issues, is a matter of technology, economics and consumer preferences. Hydrogen is abundant, but it is costly to extract in environmentally sustainable ways (most of it now is produced from fossil fuels). It can be used – and is being used – to power vehicles ranging from spacecraft to buses. But the current method of storing it, in bulky tanks, rules it out for the typical passenger car.

Chris Van de Walle, a materials professor at UCSB, breaks down the hydrogen engineering task into three issues. One of these, the conversion of hydrogen into useful energy, has been in engineers’ sights the longest. The technology of fuel cells, which produce electricity from the combining of hydrogen and oxygen to form water, is more than a century old and is “very well developed.” Van de Walle says the other two issues, generation and storage, “are still very much in the research stage.” It’s not that producing and storing hydrogen is difficult. The challenge is to do so in ways that make environmental and economic sense for large-scale consumer markets, such as the car-owning public.

Storage and generation are both targets of research at UCSB. Van de Walle’s group focuses on storage, particularly on finding lightweight materials that can hold and dispense hydrogen efficiently. Another group of researchers, including Professor Umesh Mishra in Electrical and Computer Engineering and professors Steven DenBaars and Shuji Nakamura in Materials, are experimenting with a new method to extract hydrogen directly from solar cells in water.

The extraction experiments use semiconductor technology similar to that of blue or white light-emitting diodes (LEDs). Researchers have found that gallium nitride, which produces the light in the

LEDs, can be used in combination with the element indium to separate hydrogen and oxygen in water when exposed to sunlight. The process essentially combines photovoltaics (the production of electricity from light) and electrolysis (the separation of hydrogen and oxygen using an electric current in water). The difference is that a separate power source, such as an external solar cell, is not needed. Everything happens in the gallium indium nitride semiconductor.

The gallium nitride technique was first discovered by a Japanese scientist, Kazuhiro Ohkawa, who works with Nakamura. Mishra says UCSB researchers are now working to develop electrode designs and grow materials that can produce hydrogen more efficiently than the existing technology of electrolysis powered by separate solar cells. Mishra says they are “just starting work and the results so far are much worse than electrolysis at the moment.” But the new technology, if honed to high efficiency, is potentially a big leap forward for the hydrogen economy. Van de Walle says, “Everyone here is excited about this and wants to push the research further.” (See sidebar on page 19.)

Mishra says gallium nitride hydrogen extraction has the advantage of simplicity in structure and manufacturing. “You don’t need any metals to collect the electrons,” he says. “You don’t have to fabricate anything. Basically what you do is just grow the material and you’re done.” He also notes that success here would also move photovoltaic technology forward: “If we make this work, we can also make a good gallium nitride solar cell.”

On the storage side, the engineering problem is basically that of packing sufficient energy into a small enough space without adding too much weight. Most hydrogen-powered vehicles today use compressed hydrogen stored in large tanks. This works for buses – it’s widely used in Germany, for instance – but Van de Walle says “it takes up a heck of a lot of space.” There’s

Which Way to the Hydrogen Highway?It may be the fuel of the future, but it’s a challenge to store and costly to generate. Here’s what UC Santa Barbara engineers are doing to solve those problems.

"It’s not that producing and storing hydrogen is difficult. The challenge is to do so in ways that make environmental and economic sense for large-scale consumer markets, such as the car-owning public," says Van de Walle.

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Which Way to the Hydrogen Highway?

"It’s not that producing and storing hydrogen is difficult. The challenge is to do so in ways that make environmental and economic sense for large-scale consumer markets, such as the car-owning public," says Van de Walle.

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also a problem of leakage. Loading hydrogen is a more complicated operation than filling a gas tank. Van de Walle thinks auto manufacturers feeling pressure to get hydrogen cars on the road are likely to use tanks in the early models, but he and other engineers have a different and more efficient storage technology in mind for the longer run.

Their focus is on substances that hold hydrogen like a sponge, with the hydrogen atoms bonded weakly to the crystal structure of the host material so that they can be released with a small amount of heat. Plenty of metals are known to do this. Palladium, for instance, can absorb 900 times its volume in hydrogen at room temperature. For every atom, the metal holds one hydrogen atom when the two come together as palladium hydride. But each palladium atom is 100 times heavier than a hydrogen atom, so the weight–percent storage efficiency of palladium hydride is no more than 1%. Even if this metal were more abundant and less costly, it would not work as a substitute for today’s gas tank. The amount of it needed to store hydrogen for a 300-mile driving range would be far too heavy. Researchers are aiming to produce materials that can hold at least 6 % of their weight in hydrogen.

At first glance, 6% doesn’t seem such a hard target to reach. Many materials with hydrogen-holding ability are much lighter than palladium. Magnesium is four times lighter, and each of its atoms binds not just to one but to two hydrogen atoms. So by weight, it’s eight times more efficient than palladium. “That sounds very exciting, but there are lots of other criteria to be satisfied,” says Van de Walle. A crucial requirement is easy extraction of hydrogen at low temperature. Magnesium hydride needs to be heated to 300°C (572°F) to release its hydrogen, burning up a lot of energy in the process. At the current state of knowledge, he concludes, “storing lots of hydrogen and storing it in a way you can easily get it out is really difficult.”

Van de Walle and his collaborators tackle this problem with computational experiments. Instead of producing and testing actual materials, they perform quantum-mechanical calculations to find which materials might hold the most hydrogen per weight with just the right amount of bonding strength. A key quantity is the “formation enthalpy,” the difference between the energy of a material in combination with hydrogen (the hydride compound) and the energy of the same material and the hydrogen when the hydrogen is removed. Palladium hydride is lower in energy than hydrogen and palladium separately, but not much lower. So its formation enthalpy is small, and its hydrogen atoms are not too tightly bound.

Van de Walle’s group has now taken the calculations to a higher level of complexity, investigating how bonding strength changes as hydrogen is gradually drawn out of a hydride compound – as it would be in a real-world hydrogen car. Calculations for sodium alanate, a promising storage

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Getting the H2 out of H2OScientists have long known that water can be split into molecular hydrogen (H2) and oxygen (O2) by passing a current through the water between two plates (electrodes). Hydrogen collects at the cathode, the negatively-charged electrode (where electrons enter the water), and oxygen collects at the positively charged anode. The method being investigated at UCSB by Umesh Mishra and others also uses electric current to extract hydrogen, but without the need for an external electrical source.

In the UCSB experiments, a semiconductor made from gallium nitride (GaN) with indium (In) added is immersed in water and exposed to sunlight. Like a solar cell, the semiconductor reacts to the light by creating a flow of negatively charged electrons with positively-charged spaces (called “electron holes”) that the electrons leave behind. Without water around them, the electrons would flow toward the holes, generating electrical current. Immersed in water, they bind to positively-charged hydrogen atoms, forming H2 molecules that bubble to the surface and can be collected there. The holes bind to negatively-charged oxygen atoms, forming O2 molecules.

material, show that when hydrogen atoms diffuse through the material they carry an electrical charge. “No one had seen this,” Van de Walle says. “Everybody was implicitly assuming that these hydrogen atoms were neutral.”

The upshot of this discovery is that these charges make a big difference in how storage materials release hydrogen, and a big difference in how the materials respond to the presence of impurities. Van de Walle has calculated, for instance, that a small amount of titanium added to sodium alanate has a

919

"At the current state of knowledge, storing lots of hydrogen and storing it in a way you can easily get it out is really difficult,” Van de Walle says.

Van de Walle has found that magnesium is able to bind to not one, but to two hydrogen atoms.

“huge impact” on the release of hydrogen, lowering the needed temperature from over 200°C to 100°C, the boiling point of water. “We have an explanation for why adding titanium is a good thing,” he says. “Now that we know what the mechanism is, we can look for other impurities that might be able to do a better job than titanium.”

Engineers take embedded computing to new levels of precision in their quest for greater efficiency.

aving energy can be as simple as turning off the lights when you leave a room and as elaborate as the network of little machines in a modern control system. The typical automobile is controlled for fuel efficiency at several crucial points, including the fuel injection system, the

exhaust, air intake, engine cooling, air conditioning and transmission. Among other things, sensors and computers control the mix of fuel and air, choose the most efficient gear and regulate the flow of engine coolant. Much more elaborate systems control jetliners and spacecraft, for stability and safety as well as efficiency. And the future promises much more of this technology, at higher levels of precision, interaction and complexity.

Researchers at UC Santa Barbara’s Center for Control, Dynamical Systems and Computation (CCDC) have long been working at the frontiers of control engineering. This field draws on the disciplines of mathematics, computer science and several branches of engineering – computer, chemical, electrical and mechanical. Started in 1991 by Petar Kokotovic, now an emeritus professor of electrical and computer engineering, the CCDC functions as an interdisciplinary meeting place for faculty, graduate students and visiting researchers. It’s “an umbrella that keeps us united,” says Andy Teel, a professor of electrical and computer engineering who is on the CCDC faculty and is a former director of the center. (The current director is Mustafa H. Khammash, a professor of mechanical engineering.)

Work at CCDC goes well beyond cars and fuel efficiency. The center’s research covers control problems of many kinds, from the hardware of MEMS (micro-electro-mechanical systems) to software and computational problems such as the development of algorithms for multi-layered “hybrid” systems such as the control of jetliners and the automation of freeways. But control-system theory is widely applicable. Solving

a problem in one area can lead to solutions in others. In Teel’s case, his research (focused on

feedback control algorithms for nonlinear and hybrid dynamical systems) has led him to such diverse applications as drug-

treatment scheduling for HIV patients, mobile robots, optimization of car engine performance and aerospace work. Control theory can be applied just about everywhere in a technology-driven world.

Teel’s automobile work had its roots in research that Kokotovic was pursuing with the

Ford Motor Co. when he retired. Along with a UCSB graduate student, Dobrivoje Popovic,

and Ford researchers, Teel sought a way to find the optimal settings for adjustable parameters (such as fuel and air intake, exhaust and spark timing) that affect an engine’s fuel consumption, and to do so across the full range of engine speeds and torque outputs. For this extremely accurate tuning of a running engine, the researchers came up with algorithms based on extremum seeking (ES), a control method suited to dynamic, hard-to-model systems. The object was “to work out a system to map out the characteristics of

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engines,” Teel says. In practical terms, their research helped point the way to higher fuel efficiency by showing how better to manage the engine’s efficiency-related inputs in real time.

Research as Teel’s responds to the challenge of controlling environments that grow increasingly complicated as more hardware comes into play and more functions are automated. Control theory is not just about managing specific systems, but about deciding which of these systems need to be used at any time and in any situation. Teel points to modern jetliners as an example. They use different controls (autopilot, landing approach systems) for different phases of flight, and are also designed to switch automatically from one control to another, as well as monitoring warning systems, as circumstances change. Essentially, they do as much of the pilot’s decision-making as possible. For these hybrid systems, he says, the point is not so much to solve a particular problem “but trying to figure out what are the right problems to solve.”

Roy Smith, a member of CCDC and a professor of electrical and computer engineering, is working in a similar vein. His research focuses on cooperative controls in interacting systems, specifically systems controlling spacecraft that detect planets beyond our solar system. He is using mathematical techniques that also can be applied to earthbound systems “that have multiple sensors that need to collectively share information and decide on a course of action.” That’s a good description of the computing embedded in a modern car, and Smith knows that side of automotive technology well. As far back as 1980 he was helping to develop microprocessors for real-time control of automobile engines for efficiency. Later, he worked on emissions control systems for marine engines, autos and trucks.

Smith says fuel-efficiency technology in cars could go further if sensors were deployed at more points in and around the engine – within each cylinder, for instance. The control of the air-fuel ratio now depends on sensors mounted mainly in the fuel injection and manifold, he says, which can only estimate the actual properties of combustion; sensors in the cylinders would measure the combustion directly. “This could buy you a 10% to 15% gain in efficiency,” Smith says – but maybe not without a push from government. The sensors would be costly (they need to have electronics rugged enough to work in high heat), and Smith sees the automotive industry as “very cost-sensitive.”

Smith is also working with Forrest Brewer, a professor of electrical and computer engineering, on algorithms that enable control systems to use less energy in calculations. For his part, Brewer is developing new architectures for embedded computing to simplify the processing required by MEMS devices (such as sensors) and reducing their power needs. “The control systems themselves are not a big source of energy consumption,” says Smith. “But it would be easier to put those systems in many more places and get more precise control of physical systems” if the control technology is more efficient. And “the more things you bring under control, the more you can control them for energy efficiency.”

“The more things you bring under control, the more you can control them for energy efficiency,” says Smith.

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News and Events from Engineering and the Sciences at UC Santa Barbara

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and longer wavelengths. "The result is six and a half percent efficiency," said Heeger. "This is the highest level achieved for solar cells made from organic materials. I am confident that we can make additional improvements that will yield efficiencies sufficiently high for commercial products." He expects this technology to be on the market in about three years.

The new tandem architecture the research team discovered both improves light harvesting and promises to be less expensive to produce. In their paper, the authors explain that the cells "… can be fabricated to extend over large areas by means of low-cost printing and coating technologies that can simultaneously pattern the active materials on lightweight flexible substrates."

The multilayered device is the equivalent of two cells in series, said Heeger. The deposition of each layer of the multilayer structure by processing the materials from solution is what promises to make the solar cells less expensive to produce.

The cells are separated and connected by the material TiOx, a transparent titanium oxide. This is the key to the multilayer system that allows for the higher-level efficiencies. TiOx transports electrons and is a collecting layer for the first cell. In addition, it acts as a stable foundation that allows the fabrication of the second cell, thus completing the tandem cell architecture.

The findings have implications for the evolution of sensory systems in general.

Researchers here announced they have built

the world's first mode-

locked silicon evanescent laser,

a significant step toward

combining lasers and other key

optical components with the existing electronic capabilities in silicon. The research provides a way to integrate optical and electronic functions on a single chip and enables new types of integrated circuits. It introduces a more practical technology with lower cost, lower power consumption and more compact devices. The research was published in Optics Express September 3.

Mode-locked evanescent lasers can deliver stable short pulses of laser light that are useful for many potential optical applications, including high-speed data transmission, multiple wavelength generation, remote sensing (LIDAR) and highly accurate optical clocks.

Computer technology now depends mainly on silicon electronics for data transmission. By causing silicon to emit light and exhibit other potentially useful optical properties, integration of photonic devices on silicon becomes possible. The problem in the past? It is extremely difficult, nearly impossible, to create a laser in silicon.

Less than one year ago, a research team at UCSB and Intel, led by John Bowers, a professor of electrical and computer engineering, created laser light from electrical current on silicon by placing a layer of InP above the silicon. In this new study, Bowers, Brian Koch, a doctoral student, and others have used this platform to demonstrate electrically-pumped lasers emitting 40 billion pulses of light per second. This is the first ever achievement of such a rate in

silicon and one that matches the rates produced by other mediums in standard use today. These short pulses are composed of many evenly spaced colors of laser light, which could be separated and each used to transmit different high-speed information, replacing the need for hundreds of lasers with just one.

Creating optical components in silicon will lead to optoelectronic devices that can increase the amount and speed of data transmission in computer chips while using existing silicon technology. Employing existing silicon technology would represent a less expensive and more feasible way to mass-produce future-generation devices that would use both electrons and photons to process information, rather than just electrons as has been the case in the past. This research builds upon the development of the first hybrid silicon laser, announced by UCSB and Intel a year ago, enabling new applications for silicon-based optics.

A higher efficiency organic solar cell was created by Physics Professor Alan Heeger and his research team. Heeger worked with Kwanghee Lee of Korea and a team of other scientists to create a new "tandem" organic solar cell with increased efficiency. The discovery was reported in the July 13 issue of Science.

Tandem cells are comprised of two multilayered parts that work together to gather a wider range of the spectrum of solar radiation –– at both shorter

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SHORTS... HAVE yOu HEARd?News and Events from Engineering and the Sciences at UC Santa Barbara

A tiny galaxy, the smallest in size and mass known to exist at that distance, has been identified by an international team of scientists led by two from UCSB. The scientists used data collected by NASA's Hubble Space Telescope and the W. M. Keck Observatory in Hawaii. This galaxy is about half the size, and approximately one-tenth the "weight" of the smallest distant galaxies typically observed, and it is 100 times lighter than our own Milky Way.

The findings will be published in the December 20, 2007 issue of Astrophysical Journal. "Even though this galaxy is more than six billion light years away, the reconstructed image is as sharp as the ordinary ground-based images of the nearest structure of galaxies, the Virgo cluster, which is 100 times closer to us," said lead author Phil Marshall, a postdoctoral fellow at UCSB.

Second author Tommaso Treu, an assistant professor of physics at UCSB, explained that the imaging is made possible by the fact that the newly discovered galaxy is positioned behind a massive galaxy, creating an "Einstein ring." The matter distribution in the foreground bends the light rays in much the same way a magnifying glass does. By focusing the light rays, this gravitational lensing effect increases the apparent brightness and size of the background galaxy by more than a factor of 10.

A research team led by UCSB and San Jose State University has discovered forests of a species of kelp previously thought endangered or extinct in deep waters near the Galapagos Islands. The discovery has important implications for biodiversity and the resilience of tropical marine systems to climate change. The research was published in September in the Proceedings of the National Academy of Sciences.

"The ecosystems that form in these cold, deep pockets beneath warm tropical waters look more like their cousins in California than the tropical reefs just 200 feet above," said co-author Brian Kinlan, a researcher with UCSB’s Marine Science Institute. "It is very similar to what we see when we climb a high mountain. For example, high alpine country in California looks more like Alaska."

Kinlan and Michael Graham, associate professor at SJSU, began by developing a mathematical model designed to predict likely habitat for the kelp, Eisenia galapagensis, based on information from satellites and oceanographic instruments on light, depth and nutrient availability. The research team tested the model by traveling to the predicted habitat, where they searched for the kelp. Scuba divers found the kelp forests from 40 to 200 feet below the surface, making the mission a success.

The research suggests that marine biodiversity may be more tolerant of climate change than presumed. While global warming may heat coral reefs and alter life there, marine communities may continue to thrive in kelp forests deep beneath the surface, where cooler nutrient-rich waters are less affected by surface warming.

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SHORTS... HAVE yOu HEARd?News and Events from Engineering and the Sciences at UC Santa Barbara

Matthew Tirrell, the Richard A. Auhll Professor and Dean of the College of

Engineering, was awarded the

William H. Walker Award by the American Institute of Chemical Engineers

(AIChE) in November. The award is presented to a

member of AIChE who has made an outstanding contribution to chemical engineering literature.

Tirrell has been a Sloan and a Guggenheim Fellow, a recipient of the Camille and Henry Dreyfus Teacher-Scholar Award and has received the Allan P. Colburn, Charles Stine and the Professional Progress Awards from AIChE, and delivered its Institute Lecture in 2001. He is a member of the National Academy of Engineering, a Fellow of the American Institute of Medical and Biological Engineers, a Fellow of the American Association for the Advancement of Science and a fellow of the American Physical Society. In 2003, he concluded more than two years of service as co-chair of the steering committee for the National Research Council, producing a report "Beyond the Molecular Frontier: Challenges for Chemistry and Chemical Engineering," published by the National Academy Press. He currently serves on the Board of Directors of the Cottage Health System in Santa Barbara.

Tirrell's research is focused on the manipulation and measurement of interfacial properties of materials used in applications from coatings and adhesion to lubrication and bioengineering.

AIChE is the world’s leading organization for chemical engineers, with more than 40,000 members from 93 countries.

Oscar H. Ibarra, a professor of computer science, has been awarded the 2007 Blaise Pascal Medal for Computer Science by the European Academy of Sciences. The academy established the medal in 2003 to recognize outstanding and demonstrated personal contributions to science and technology, and the promotion of excellence in research and education.

The award to Ibarra is in recognition of his outstanding contributions in theory of computing, design and analysis of algorithms, computational complexity, parallel computing, formal verification and membrane computing. The European Academy of Sciences is a non-profit, non-governmental, independent organization of distinguished scholars and engineers engaged in research and development of advanced technologies.

Virgil Elings and Betty

Elings Wells gave $12.5 million gift to support research and innovation at

the California NanoSystems

Institute (CNSI). In recognition of their gift, the new CNSI building will be named Elings Hall.

The CNSI is a multidisciplinary research partnership between UCLA and UC Santa Barbara established by the state in 2000 with the support of the state legislature and California industry. By exploring the power and potential of manipulating structures molecule-by-molecule, the CNSI is creating revolutionary new materials, devices, and systems that will enhance virtually every aspect of our lives –

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Virgil Elings

Betty Elings Wells

secretary of the corporation.

Wells said that she made the gift to UCSB to honor her former husband and mentor, the devoted employees at Digital Instruments – many of whom were UCSB graduates – and to support the university with which she has been affiliated since her arrival in Santa Barbara 40 years ago.

The CNSI building, now known as Elings Hall, stands near the eastern entrance to the campus and is the hub for nano-science research at UCSB.

UC Santa Barbara has received a $350,000 gift from Tegal Corporation, of Petaluma, to establish an endowed chair for the director of the California NanoSystems Institute (CNSI). The professorship will be named for the late scientific pioneer Peter J. Clarke, a longtime Santa Barbara resident and founder of Sputtered Films Inc. In 1967, Clarke invented the first commercially successful magnetron sputtering device in his basement laboratory.

Tegal is a leading designer and manufacturer of plasma etch and

Written and reported by staff writers and editors, and by staff from the Office of Public Affairs.

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SHORTS... HAVE yOu HEARd?News and Events from Engineering and the Sciences at UC Santa Barbara

helping to drive California's economy through innovations in medical delivery and health care, powerful new information technologies, energy efficient devices, environmental improvements and more.

The Elings and Wells gift is the largest contribution to The Campaign for UC Santa Barbara, which seeks to raise $500 million to ensure UCSB's excellence for future generations. With this recent gift, a total of $449 million has been contributed to The Campaign by alumni and friends.

Virgil Elings is a former UCSB professor of physics who made fundamental contributions leading to the scientific revolution at the nano-scale. In 1987, he co-founded Digital Instruments (DI), which made the power of atomic scanning probe microscopy readily available to scientists and engineers, enabling them to view and explore nano-scale features and structures never seen before – a critical starting point in nano-science and nano-technology.

During their marriage, Betty Elings Wells was a real estate investor and business partner with her former husband, Virgil Elings. Together, they launched numerous entrepreneurial ventures, including Digital Instruments, where she was office manager and

deposition systems used in the production of integrated circuits, MEMS, and nano-technology devices. The recent gift was made through Sputtered Films, which is now a subsidiary of Tegal. Sputtered Films' success is based largely on Clarke's brilliant invention and its subsequent evolution.

Thomas Mika, chairman and president of Tegal, said the company's contribution to UCSB recognizes Clarke's pivotal role in advancing technology, his love of collaborative multidisciplinary scientific research, and his deep bond with the campus and long and fruitful collaboration with Evelyn Hu, scientific director of the CNSI and the first to hold the Clarke Chair.

Hu, who is also a professor of electrical and computer engineering and materials, said she was honored to be appointed to the Clarke Chair and grateful to Tegal for its generosity. Her research focuses on the formation of nano-photonic devices that may provide more energy-efficient lighting sources and may also facilitate new, faster computation and communications.

some point, they have to make a compelling “buy me now” case to ordinary consumers and most businesses.

This is where it’s essential to pay attention to economics – specifically environmental economics, the specialty of Charles D. Kolstad, a professor in UCSB’s Donald Bren School of Environmental Science & Management.

Some existing energy-efficient technology sits on the shelf because of cost and quality issues, Kolstad says. “The problem often isn’t that something is physically impossible. Usually it’s just too expensive” – and not quite good enough to make consumers want to switch. Kolstad cites the case of compact fluorescent lamps (CFLs), which he notes “have been around a long time” without being widely adopted by consumers. “Some people who are technologists say, ‘Why don’t people replace incandescents with these things?’ Well, they just haven’t worked as well. Sometimes the color is off. Sometimes they’re not very bright.” CFLs have improved and are starting to take off now, but they’re getting help from subsidies (courtesy of utility companies) and regulations pushing their use.

As for solid state lighting – LEDs – Kolstad sees these as “the light of the future, but the fit with consumer needs has to improve and the price has to follow.” Fuel-efficient cars such as hybrids, he says, will be a harder sell as long “you have low prices of gasoline” (and he considers $3 a gallon still relatively cheap). Kolstad thinks solar cells may make their case on cost alone, with quality and performance issues less significant. Rising electricity rates and the falling cost-per-watt of photovoltaics will drive demand. But for solar power to become “a big part of the solution,” it will have to overcome a fundamental feature of solar – it only works when the sun is shining.

So what works? Kolstad cites the recent history of batteries as a case in which demand aligned with technology to produce big gains in efficiency. Consumer demand for more compact cell phones with more features other than basic calling drove engineers to develop much lighter, smaller, higher-capacity battery technology. “We tend to forget what phones were like 15 years ago,” Kolstad says. “They were like bricks we were carrying around.” Demand for efficiency in cars is more difficult to produce. The most direct way is to impose a tax that sharply raises gas prices, but Kolstad notes that this is “a very hard thing to do in the U.S.” That leaves the regulatory option – tightening fuel economy rules – with help from a gas guzzler tax. It takes higher prices to make people conserve, Kolstad says, but fuel economy standards alone advance energy efficiency and “still do a lot of good.”

Will LED's Light the Way?Continued from page 14

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FALL 2007, NINE

Editor in Chief: Barbara Bronson Gray

Creative Director: Peter Allen

Senior Writer: Tom Gray

Copy Editor: Marie Howell

Editorial Board:Matthew Tirrell, Dean, College of EngineeringSteven Gaines, Acting Dean of Mathematical, Life and Physical Sciences, College of Letters and ScienceEvelyn Hu, Scientific Director, California NanoSystems InstituteGeorge Thurlow, Executive Director and Assistant Vice Chancellor, Alumni AssociationKristi Newton, Assistant Dean of Development, Engineering and the SciencesBarbara Bronson Gray, Communications and Media Relations, Engineering and the SciencesPeter Allen, Marketing Director, Engineering and the SciencesJoy Williams, Assistant Dean for Budget and Administration, EngineeringMichelle Keuper, Executive Assistant to the Dean, College of Letters and Science

Convergence is a publication of Engineering and the Sciences at the University of California, Santa Barbara, CA 93106-5130.

To make a change of address: please send e-mail to [email protected] or send your name and new address to Marie Howell, Marketing Coordinator, Engineering and the Sciences, UC Santa Barbara, Santa Barbara, CA 93106-5130.

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CONVERGENCEThe Magazine of Engineering and the Sciences at UC Santa Barbara

What is this? Answer from page 23

This image of a fractal was generated by computer science students Chris Grzegorczyk and Kyo Lee using their real time interactive parallel visualization tool (started in Prof. John Gilbert's CS240A course). The picture is a rendering of the trajectories of points under the action of f(z)=z^2+c, for z and c in C. The intensity of each pixel reflects the frequency with which the corresponding region is visited (which is very expensive computationally), rather than the traditional method which reflects only the number of iterations.

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