Solar Decathlon

Students from Caltech and the Southern California Institute of Architecture (SCI-Arc) have been chosen to build a green house near the White House. They will compete against teams from around the world in the biennial Solar Decathlon, sponsored by the U.S. Department of Energy. Taking place in October 2011 on the National Mall in Washington, D.C., the two-week event will challenge teams of university students to design and build the most affordable, attractive, and energy-efficient house they can.

A panel of scientists, engineers, and other experts from the DOE's National Renewable Energy Laboratory selected the SCI-Arc/Caltech team as one of the 20 teams whose proposals and concept designs were the best. Now that they've been chosen, the students have 18 months to design, test, and build a state-of-the-art, solar-powered house—and they have to figure out how to transport it across the country and assemble it in the few days leading up to the event. "I can't think of any other project that I've done in the past that even compares in magnitude,"says Fei Yang, one of the student leaders at Caltech.

For the first time, the Decathlon will require the houses to cost $250,000 or less. The houses, which will be open to the public, must be within 600 and 1,000 square feet. The Decathlon's 10 "events" range from completing certain tasks, such as heating 15 gallons of water in under 10 minutes, to being judged by a panel of experts on such subjective aspects as the aesthetics of the architecture.

SCI-Arc first approached Caltech's chapter of Engineers for a Sustainable World, of which Yang is president, to recruit Techers to join the team. Yang, a junior mechanical engineering major, and Ben Kurtz, a junior physics major who helps lead the Caltech crew, say they jumped at the opportunity to get their hands dirty. "I think the difference between this and almost any other research project you can do at Caltech is that this is an immediate opportunity to affect the way things are done in the real world, and the way people live," Kurtz says. Ideally, they hope a contractor will be sufficiently impressed with their design to build and market their house.

As first-time participants coming from small schools, the SCI-Arc and Caltech team members are definitely underdogs, Yang says. Seven faculty members have already offered their guidance and expertise in a series of reading courses, and a new class is in the works for the next term. At this point, fewer than 20 Caltech students are involved. But as the team members proceed past the initial planning stages and toward actual construction, they will need more than a hundred people—and they're recruiting, Yang says. "We need as much help as we can get," adds Kurtz. "Anybody who wants to help is welcome."

Some of the features of the SCI-Arc-Caltech prototype are angled walls that minimize the amount of heating from the sun and a tilted roof that maximizes energy production from solar panels.

The team is sponsored by the Resnick Institute, which is providing financial support and helping with advising and fundraising.

Listen to an audio podcast about this project.

Marcus Woo
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Caltech Researchers Create Highly Absorbing, Flexible Solar Cells with Silicon Wire Arrays

PASADENA, Calif.—Using arrays of long, thin silicon wires embedded in a polymer substrate, a team of scientists from the California Institute of Technology (Caltech) has created a new type of flexible solar cell that enhances the absorption of sunlight and efficiently converts its photons into electrons. The solar cell does all this using only a fraction of the expensive semiconductor materials required by conventional solar cells.

"These solar cells have, for the first time, surpassed the conventional light-trapping limit for absorbing materials," says Harry Atwater, Howard Hughes Professor, professor of applied physics and materials science, and director of Caltech's Resnick Institute, which focuses on sustainability research.

The light-trapping limit of a material refers to how much sunlight it is able to absorb. The silicon-wire arrays absorb up to 96 percent of incident sunlight at a single wavelength and 85 percent of total collectible sunlight. "We've surpassed previous optical microstructures developed to trap light," he says. 

Atwater and his colleagues—including Nathan Lewis, the George L. Argyros Professor and professor of chemistry at Caltech, and graduate student Michael Kelzenberg—assessed the performance of these arrays in a paper appearing in the February 14 advance online edition of the journal Nature Materials.

Atwater notes that the solar cells' enhanced absorption is "useful absorption."

"Many materials can absorb light quite well but not generate electricity—like, for instance, black paint," he explains. "What's most important in a solar cell is whether that absorption leads to the creation of charge carriers."

The silicon wire arrays created by Atwater and his colleagues are able to convert between 90 and 100 percent of the photons they absorb into electrons—in technical terms, the wires have a near-perfect internal quantum efficiency. "High absorption plus good conversion makes for a high-quality solar cell," says Atwater. "It's an important advance."

The key to the success of these solar cells is their silicon wires, each of which, says Atwater, "is independently a high-efficiency, high-quality solar cell." When brought together in an array, however, they're even more effective, because they interact to increase the cell's ability to absorb light.

"Light comes into each wire, and a portion is absorbed and another portion scatters. The collective scattering interactions between the wires make the array very absorbing," he says.

This is a photomicrograph of a silicon wire array embedded within a transparent, flexible polymer film.
Credit: Caltech/Michael Kelzenberg

This effect occurs despite the sparseness of the wires in the array—they cover only between 2 and 10 percent of the cell's surface area.

"When we first considered silicon wire-array solar cells, we assumed that sunlight would be wasted on the space between wires," explains Kelzenberg. "So our initial plan was to grow the wires as close together as possible. But when we started quantifying their absorption, we realized that more light could be absorbed than predicted by the wire-packing fraction alone. By developing light-trapping techniques for relatively sparse wire arrays, not only did we achieve suitable absorption, we also demonstrated effective optical concentration—an exciting prospect for further enhancing the efficiency of silicon-wire-array solar cells."

Each wire measures between 30 and 100 microns in length and only 1 micron in diameter. “The entire thickness of the array is the length of the wire,” notes Atwater. “But in terms of area or volume, just 2 percent of it is silicon, and 98 percent is polymer.”

In other words, while these arrays have the thickness of a conventional crystalline solar cell, their volume is equivalent to that of a two-micron-thick film.

Since the silicon material is an expensive component of a conventional solar cell, a cell that requires just one-fiftieth of the amount of this semiconductor will be much cheaper to produce.

The composite nature of these solar cells, Atwater adds, means that they are also flexible. "Having these be complete flexible sheets of material ends up being important," he says, "because flexible thin films can be manufactured in a roll-to-roll process, an inherently lower-cost process than one that involves brittle wafers, like those used to make conventional solar cells."

Atwater, Lewis, and their colleagues had earlier demonstrated that it was possible to create these innovative solar cells. "They were visually striking," says Atwater. "But it wasn't until now that we could show that they are both highly efficient at carrier collection and highly absorbing."

The next steps, Atwater says, are to increase the operating voltage and the overall size of the solar cell. "The structures we've made are square centimeters in size," he explains. "We're now scaling up to make cells that will be hundreds of square centimeters—the size of a normal cell."

Atwater says that the team is already "on its way" to showing that large-area cells work just as well as these smaller versions.

In addition to Atwater, Lewis, and Kelzenberg, the all-Caltech coauthors on the Nature Materials paper, "Enhanced absorption and carrier collection in Si wire arrays for photovoltaic applications," are postdoctoral scholars Shannon Boettcher and Joshua Spurgeon; undergraduate student Jan Petykiewicz; and graduate students Daniel Turner-Evans, Morgan Putnam, Emily Warren, and Ryan Briggs.

Their research was supported by BP and the Energy Frontier Research Center program of the Department of Energy, and made use of facilities supported by the Center for Science and Engineering of Materials, a National Science Foundation Materials Research Science and Engineering Center at Caltech. In addition, Boettcher received fellowship support from the Kavli Nanoscience Institute at Caltech.

Lori Oliwenstein

Caltech Opens "Green" Building Offering New Opportunities in Information Science

Annenberg Center for Information Science and Technology combines multiple academic efforts under one roof

Pasadena, Calif., Oct. 30, 2009-New ideas in architecture will foster new ideas in information science as the California Institute of Technology (Caltech) opens its groundbreaking "green" building, the Walter and Leonore Annenberg Center for Information Science and Technology.

Designed by Los Angeles architectural firm Frederick Fisher and Partners, the Annenberg Center will serve as home to interdisciplinary research and instruction that address the growth and impact of information as it relates to all scientific and engineering practices.

Researchers in this emerging academic discipline come from five of Caltech's six academic divisions. The aim of the new facility is to bring physicists, biologists, engineers, and computer scientists together to foster collaboration and interdisciplinary research and teaching.

"The choice we made to bring together researchers from across disciplines has already led to new research and hiring practices," says Ares Rosakis, chair of the Division of Engineering and Applied Science (EAS) and Theodore von Kármán Professor of Aeronautics and Mechanical Engineering at Caltech.

In a move to help cultivate the potential wealth of new ideas, the building was created-inside and out-with sustainability in mind.

"A workplace should be a source of inspiration," says Rosakis. "As with other newly renovated Caltech buildings, the innovative design of this building inspires its residents."

The building-one of three new "green" constructions on the Caltech campus-is seeking a gold certification from the Leadership in Energy and Environmental Design (LEED). The coveted designation would be a result of the building's water and energy efficiency (30 percent reduction in water use; 28 percent reduction in energy use); use of recycled materials (more than 20 percent of materials have recycled content and have local or regional origins); and indoor environmental quality. The bamboo found throughout the building adds to the list of sustainable materials in use.

The construction of this state-of-the-art building was funded primarily by a $25-million gift from the Annenberg Foundation, founded in 1989 by Walter H. Annenberg and later led by his wife, Leonore. The foundation encourages the development of more effective ways to share ideas and knowledge, exemplified in the new building by its cross-disciplinary structure.

Funding also came from the Gordon and Betty Moore Foundation and Stephen D. Bechtel, Jr.

"Information science will provide the intellectual foundation for the exploitation of information across diverse disciplines," says Caltech president Jean-Lou Chameau. "It will result in the education of a new generation of leaders and the creation of innovative scientific, technological, and business models. The Annenberg Center will be the catalyst for this bold venture undertaken by the Caltech faculty."

Other highlights of the new building include

  • quantity and quality control for storm water;
  • individual HVAC controls and operable windows; and
  • a minimum of 75 percent of spaces with daylight access.

Faculty members are housed on the second and third floors of the Annenberg Center, where offices are designed with floor-to-ceiling windows to take advantage of the exterior views. Each of the rooms in the building has sensors that save on the use of energy for lighting, heating, and air-conditioning.

Spaces within the building include

  • 16 faculty offices, with an additional four for visiting faculty;
  • 16 studios for students;
  • 14 postdoctoral offices;
  • 33 graduate-student offices;
  • 14 administrative offices;
  • two lounge areas;
  • three kitchens;
  • five classrooms;
  • an auditorium;
  • a computer lab; and
  • a conference room.

The second-floor atrium contains unique bamboo screens, a staircase, and a skylight that gives the area an open feeling conducive to casual, collegial collaboration.  

The building uses furniture of classic and contemporary design to create an inspiring and inviting atmosphere. The lounge area has a spiral staircase connecting its two levels, and creating a spacious open area with an abundance of natural light.

The exterior landscaping of the Annenberg Center follows Caltech's goal to improve campus sustainability by including a multitude of native drought-resistant plants and hardscaping.

For a visual tour of the center, visit

Jon Weiner
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Caltech Researchers Show How Organic Carbon Compounds Emitted by Trees Affect Air Quality

Research provides first-ever glimpse of role of epoxides in atmospheric chemistry

PASADENA, Calif.—A previously unrecognized player in the process by which gases produced by trees and other plants become aerosols—microscopically small particles in the atmosphere—has been discovered by a research team led by scientists at the California Institute of Technology (Caltech).

Their research on the creation and effects of these chemicals, called epoxides, is being featured in this week's issue of the journal Science.

Paul Wennberg, the R. Stanton Avery Professor of Atmospheric Chemistry and Environmental Science and Engineering and director of the Ronald and Maxine Linde Center for Global Environmental Science at Caltech, and John Seinfeld, the Louis E. Nohl Professor and professor of chemical engineering, have been studying the role of biogenic emissions—organic carbon compounds given off by plants and trees—in the atmospheric chemical reactions that result in the creation of aerosols.

"If you mix emissions from the city with emissions from plants, they interact to alter the chemistry of the atmosphere," Wennberg notes.

While there's been plenty of attention paid to the effect of emissions from cars and manufacturing, less is understood about what happens to biogenic emissions, especially in places where there are relatively few man-made emissions. That situation is the focus of the research that led to this Science paper. "What we're interested in," Wennberg explains, "is what happens to the chemicals produced by trees once they are emitted into the atmosphere."

In these studies, the research team focused on a chemical called isoprene, which is given off by many deciduous trees. "The king emitters are oaks," Wennberg says. "And the isoprene they emit is one of the reasons that the Smoky Mountains appear smoky."

Isoprene is no minor player in atmospheric chemistry, Wennberg notes. "There is much more isoprene emitted to the atmosphere than all of the gases—gasoline, industrial chemicals—emitted by human activities, with the important exceptions of methane and carbon dioxide," he says. "And isoprene only comes from plants. They make hundreds of millions of tons of this chemical . . . for reasons that we still do not fully understand."

"Much of the emission of isoprene occurs where anthropogenic emissions are limited," adds Caltech graduate student Fabien Paulot, the paper's first author. "The chemistry is very poorly understood."

Once released into the atmosphere, isoprene gets "oxidized or chewed on" by free-radical oxidants such as OH, explains Wennberg. It is this chemistry that is the focus of this new study. In particular, the research was initiated to understand how the oxidation of isoprene can lead to formation of atmospheric particulate matter, so-called secondary organic aerosol. "A small fraction of the isoprene becomes secondary organic aerosol," Seinfeld notes, "but because isoprene emissions are so large, even this small fraction is important."

Up until now, the chemical pathways from isoprene to aerosol were not known. Wennberg, Seinfeld, and their colleagues discovered that this aerosol likely forms from chemicals known as epoxides.

The name is apt. "These epoxides are nature's glue," says Wennberg. And, much like the epoxy you buy in a hardware store—which requires the addition of an acid for the compound to turn into glue—the epoxides found in the atmosphere also need an acidic kick in order to become sticky.

"When these epoxides bump into particles that are acidic, they make glue," Wennberg explains. "The epoxides precipitate out of the atmosphere and stick to the particles, growing them and resulting in lowered visibility in the atmosphere." Because the acidity of the aerosols is generally higher in the presence of anthropogenic activities, the efficiency of converting the epoxides to aerosol is likely higher in polluted environments, illustrating yet another complex interaction between emissions from the biosphere and from humans. 

"Particles in the atmosphere have been shown to impact human health, as they are small enough to penetrate deep into the lungs of people. Also, aerosols impact Earth's climate through the scattering and absorption of solar radiation and through serving as the nuclei on which clouds form. So it is important to know where particles come from," notes Seinfeld.

The research team was able to make this scientific leap forward thanks to their development of a new type of chemical ionization mass spectrometry (CIMS), led by coauthor and Caltech graduate student John Crounse. "These new CIMS methods open up a very wide range of possibilities for the study of new sets of compounds that scientists have been largely unable to measure previously, mainly because they decompose when analyzed with traditional techniques."

In general, molecules identified and quantified using mass spectroscopy must first be converted to charged ions. They are then directed into an electric field, where the ions are sorted by mass. The problem with traditional ionization techniques is that delicate molecules, such as those produced in the oxidation of isoprene, generally fragment during the ionization process, making their identification difficult or impossible. "This new method was originally developed in order to allow scientists to make atmospheric measurements from airplanes. It is able to ionize gases, even fragile peroxide compounds, while still preserving information about the size or mass of the original molecule," says Wennberg.

That makes determining the individual gases in a complex mixture much easier—especially when, as it turned out, you're looking at a chemical you weren't expecting to find.

Wennberg and colleagues also used oxygen isotopes—oxygen atoms with different numbers of neutrons in their nucleus, and thus different masses—to gain insight into the chemical mechanism yielding epoxides. Epoxides have remained unindentified so far because they have the same mass as another chemical that had been anticipated to form in isoprene oxidation, peroxide. "The oxygen isotopes separated the peroxides from epoxides and further showed that as the epoxides form, OH is recycled to the atmosphere," comments Paulot. "Since OH is the atmosphere detergent, cleaning the atmosphere of many chemicals, the recycling has important implications for the overall oxidizing capacity of the atmosphere."

The identification of a major photochemical pathway to formation of epoxides helps to explain just how tree emissions of organic carbon compounds influence the air in both city and rural settings. While trees aren't exactly the "killers" that Ronald Reagan was once so famously derided for calling them, their isoprene emission levels can—and often probably should—"be a part of the criteria we use when buying and planting trees in a polluted urban setting," notes Wennberg. In fact, he points out, the South Coast Air Quality Management District in Southern California already does this with its list of "approved" trees that don't emit large amounts of organic carbon compounds into the atmosphere.

In addition to Wennberg, Paulot, Crounse, and Seinfeld, other authors on the Science paper, "Unexpected epoxide formation in the gas-phase photooxidation of isoprene," are Henrik Kjaergaard of the University of Otago in New Zealand and the University of Copenhagen in Denmark; former Caltech postdoctoral scholar Andreas Kürten, now at Goethe University in Germany; and Caltech postdoctoral scholar Jason St. Clair.

Purchase of the mass spectrometer used in this study was funded by a Major Research Instrumentation Award from the National Science Foundation. Additional support for the work described in the Science article came from Caltech trustee William Davidow and by grants from the Office of Science, the U.S. Department of Energy, the U.S. Environmental Protection Agency, the Royal Society of New Zealand, and NASA.

Lori Oliwenstein
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Caltech Researchers Link Tiny Sea Creatures to Large-scale Ocean Mixing

Mechanism, which focuses on impact of drag and water viscosity, shows how swimming animals affect the ocean environment

PASADENA, Calif. —Using a combination of theoretical modeling, energy calculations, and field observations, researchers from the California Institute of Technology (Caltech) have for the first time described a mechanism that explains how some of the ocean's tiniest swimming animals can have a huge impact on large-scale ocean mixing.

Their findings are being published in the July 30 issue of the journal Nature.

"We've been studying swimming animals for quite some time," says John Dabiri, a Caltech assistant professor of aeronautics and bioengineering who, along with Caltech graduate student Kakani Katija, discovered the new mechanism. "The perspective we usually take is that of how the ocean—by its currents, temperature, and chemistry—is affecting the animals. But there have been increasing suggestions that the inverse is also important-how the animals themselves, via swimming, might impact the ocean environment."

Specifically, Dabiri says, scientists have increasingly been thinking about how and whether the animals in the ocean might play a role in larger-scale ocean mixing, the process by which various layers of water interact with one another to distribute heat, nutrients, and gasses throughout the oceans.

Dabiri notes that oceanographers have previously dismissed the idea that animals might have a significant effect on ocean mixing, saying that the viscosity of water would damp out any turbulence created, especially by small planktonic animals. "They said that there was no mechanism by which these animals could impact large-scale ocean mixing," he notes.

But Dabiri and Katija thought there might be a mechanism that had been overlooked—a mechanism they call Darwinian mixing, because it was first discovered and described by Charles Darwin. (No, not that Darwin; his grandson.)

"Darwin's grandson discovered a mechanism for mixing similar in principle to the idea of drafting in aerodynamics," Dabiri explains. "In this mechanism, an individual organism literally drags the surrounding water with it as it goes."

Using this idea as their basis, Dabiri and Katija did some mathematical simulations of what might happen if you had many small animals all moving at more or less the same time, in the same direction. After all, each day, billions of tiny krill and copepods migrate hundreds of meters from the depths of the ocean toward the surface. Darwin's mechanism would suggest that they drag some of the colder, heavier bottom water up with them toward the warmer, lighter water at the top. This would create instability, and eventually, the water would flip, mixing itself as it went.

What the Caltech researchers also found was that the water's viscosity enhances Darwin's mechanism and that the effects are magnified when you're dealing with such minuscule creatures as krill and copepods. "It's like a human swimming through honey," Dabiri explains. "What happens is that even more fluid ends up being carried up with a copepod, relatively speaking, than would be carried up by a whale."

"This research is truly reflective of the type of exciting, without-boundaries research at which Caltech engineering professors excel—in this case a deep analysis of the movement of fluid surrounding tiny ocean creatures leading to completely revelatory insights on possible mechanisms of global ocean mixing," says Ares Rosakis, chair of the Division of Engineering and Applied Science at Caltech.

To verify the findings from their simulations, Katija and collaborators Monty Graham (from the Dauphin Island Sea Laboratory), Jack Costello (from Providence College), and Mike Dawson (from the University of California, Merced) traveled to the island of Palau, where they studied this animal-led transport of water—otherwise known as induced drift—among jellyfish, which are the focus of much of Dabiri's work.

"From a fluid mechanics perspective, this study had less to do with the fact that they're jellyfish, and more to do with the fact that they're solid objects moving through water," Dabiri explains.

Katija's jellyfish experiments involved putting fluorescent dye in the water in front of the sea creatures, and then watching what happened to that dye—or, to be more specific, to the water that took up the dye—as the jellyfish swam. And, indeed, rather than being left behind the jellyfish—or being dissipated in turbulent eddies—the dye travelled right along with the swimming creatures, following them for long distances.

These findings verified that, yes, swimming animals are capable of carrying bottom water with them as they migrate upward, and that movement indeed creates an inversion that results in ocean mixing. But what the findings didn't address was just how much of an impact this type of ocean mixing—performed by impossibly tiny sea creatures—could have on a large scale.

After a series of calculations, Dabiri and Katija were able to estimate the impact of this so-called biogenic ocean mixing. And, Dabiri says, it's quite a significant impact.

"There are enough of these animals in the ocean," he notes, "that, on the whole, the global power input from this process is as much as a trillion watts of energy—comparable to that of wind forcing and tidal forcing."

In other words, the amount of power that copepods and krill put into ocean mixing is on the same scale as that of winds and tides, and thus their impact is expected to be on a similar scale as well.

And while these numbers are just estimates, Dabiri says, they are likely to be conservative estimates, having been "based on the fluid transport induced by individual animals swimming in isolation." In the ocean, these individual contributions to fluid transport may actually interact with one another, and amplify how far the ocean waters can be pulled upward.

In addition, says Dabiri, they have yet to consider the effects of such things as fecal pellets and marine snow (falling organic debris), which no doubt pull surface water with them as they drift downward. "This may have an impact on carbon sequestration on the ocean floor," says Dabiri. "It's something we need to look at in the future."

Dabiri says the next major question to answer is how these effects can be incorporated into computer models of the global ocean circulation. Such models are important for simulations of global climate-change scenarios.

The work described in the Nature paper, "A viscosity-enhanced mechanism for biogenic ocean mixing," was supported by grants from the National Science Foundation's Biological Oceanography, Ocean Technology, Fluid Dynamics, and Energy for Sustainability programs, and by the Office of Naval Research, the Department of Defense's National Science and Engineering Graduate Fellowship, and the Charles Lee Powell Foundation.

Lori Oliwenstein
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Caltech Announces Initiative for a New $90 Million Sustainability Institute

Initial $30 million in gifts revealed at Institute's commencement ceremony

Pasadena, Calif.—As the U.S. Secretary of Energy and hundreds of graduates and their families looked on, California Institute of Technology (Caltech) president Jean-Lou Chameau began today's commencement ceremony by announcing $30 million in gifts as the first phase of a proposed $90 million initiative for a new institute.

The funds will go towards the creation of the Resnick Sustainability Institute at Caltech. The initial gift of $20 million was made by Stewart and Lynda Resnick, and an additional $10 million came from the Gordon and Betty Moore Matching Program. The plans include a second phase of funding to be initiated next year as part of a challenge grant. Ultimately, the endowment for the new institute will exceed $90 million.

The vision of the Resnick Sustainability Institute is to provide a path to sustainability by focusing on innovative science and engineering developments required for groundbreaking energy technologies.  Such technologies may one day help solve our global energy and climate challenges. With the support of the Resnick Sustainability Institute, some of the brightest minds in the world will apply Caltech's unique approach to interdisciplinary research toward high-risk, high-return energy science and technology. 

"I have enjoyed many conversations with Stewart and Lynda on exciting developments in science and technology and their potential for addressing many of our environmental and economic challenges," says Chameau. "This generous gift from the Resnicks reflects their extraordinary desire and courage to make a difference. With their support, we are poised to launch an initiative at Caltech that will herald a new era in energy research."

"We are passionately committed to finding alternative and sustainable energy solutions," say Stewart and Lynda Resnick.  "We're making this investment because Caltech is truly one of America's greatest research universities, and we are confident that this new institute will develop the breakthrough technologies we need to address the daunting challenges of energy security, rapidly accelerating energy demand, and climate change."

The new institute will leverage prior grants from the Gordon and Betty Moore Foundation and work being done by Caltech researchers such as Harry Atwater, the Howard Hughes Professor and professor of applied physics and materials science, who leads Caltech's Energy Frontier Research Center, recently funded by the Department of Energy; and Harry Gray, the Arnold O. Beckman Professor of Chemistry, and Nate Lewis, the George L. Argyros Professor and professor of chemistry, who lead Caltech's Center for Chemical Innovation, funded by the National Science Foundation.

The Resnicks' existing relationship with Caltech includes Stewart Resnick's role as a member of the Board of Trustees. He is also chairman and, with his wife, Lynda, owner of Roll International Corporation, a private holding company he founded in 1962. The company has diverse interests including Paramount Citrus, Paramount Farming, and Paramount Farms, growers and processors of citrus, almonds, and pistachios; POM Wonderful, the largest grower of pomegranates and makers of POM Wonderful pomegranate juice; Teleflora, the floral-by-wire service; FIJI Water, a leading premium bottled-water brand; and Suterra, one of the largest biorational pest control providers in the world.

The Resnicks have a long history of giving to Los Angeles institutions, including a 2008 pledge of $55 million to the Los Angeles County Museum of Art.

The announcement of the gift was made during Chameau's opening remarks at Caltech's 115th annual commencement ceremony. This year's keynote speaker, Department of Energy Secretary Steven Chu, remarked that the timing of the gift announcement was especially appropriate, as it involved energy science and sustainability, two of his programmatic efforts at the energy department.

# # #

About the Resnicks:

Stewart Resnick is chairman and Lynda Resnick is vice chairman of Roll International Corporation, a privately held Los Angeles-based holding company.  Among their holdings are Paramount Citrus, Paramount Farming, and Paramount Farms, growers and processors of citrus, almonds, and pistachios; POM Wonderful, the largest grower of pomegranates and makers of the all-natural POM Wonderful pomegranate juice; Teleflora, the floral-by-wire service; FIJI Water, a leading premium bottled-water brand; and Suterra, one of the largest biorational pest control providers in the world.

Stewart Resnick is a member of the executive board of the UCLA Medical Sciences; a member of the board of trustees of Bard College, New York; a member of the board of trustees of the J. Paul Getty Trust; a member of the board of Conservation International; and a member of the advisory board of the Anderson School of Management at UCLA.

Lynda Resnick is vice chairman of the Los Angeles County Museum of Art's board of trustees, as well as the chair of the museum's acquisitions committee and executive committees. She is on the executive board of the Aspen Institute; the executive board for the UCLA Medical Sciences; Prostate Cancer Foundation; and the Milken Family Foundation. She is also a trustee of the Philadelphia Museum of Art. Lynda is also the best-selling author of the recently published book Rubies in the Orchards: How to Uncover the Hidden Gems in Your Business.


About Gordon and Betty Moore:

Gordon and Betty Moore are the cofounders and directors of the Gordon and Betty Moore Foundation. They have been contributing to science, technology, education, and conservation projects for decades. A California native,  Moore earned a PhD in chemistry from Caltech in 1954. In 1968 he cofounded Intel, and became president and CEO in 1975. He was elected chairman and CEO in 1979. In 1987, he relinquished the CEO title, he was named chairman emeritus in 1997. Moore is also a member of the National Academy of Engineering and an IEEE Fellow. He received the National Medal of Technology in 1990 and was named a Caltech Distinguished Alumni in 1975. Moore served as chairman of the Caltech Board of Trustees from 1995 until the beginning of 2001 and continues as a senior trustee. In 2001, the Moores announced two gifts to Caltech totaling $600 million--the largest donation in history to an institution of higher education.

About Caltech:

Caltech is recognized for its highly select student body of 900 undergraduates and 1,200 graduate students, and for its outstanding faculty. Since 1923, Caltech faculty and alumni have garnered 32 Nobel Prizes and five Crafoord Prizes.

In addition to its prestigious on-campus research programs, Caltech operates the Jet Propulsion Laboratory, the W. M. Keck Observatory in Mauna Kea, the Palomar Observatory, and the Laser Interferometer Gravitational-Wave Observatory (LIGO). Caltech is a private university in Pasadena, California. For more information, visit

Jon Weiner
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Caltech Scientists Predict Greater Longevity for Planets with Life

Billion-year life extension for Earth also doubles the odds that advanced life will be found elsewhere in the universe

PASADENA, Calif.- Roughly a billion years from now, the ever-increasing radiation from the sun will have heated Earth into uninhabitability; the carbon dioxide in the atmosphere that serves as food for plant life will disappear, pulled out by the weathering of rocks; the oceans will evaporate; and all living things will disappear.

Or maybe not quite so soon, say researchers from the California Institute of Technology (Caltech), who have come up with a mechanism that doubles the future lifespan of the biosphere—while also increasing the chance that advanced life will be found elsewhere in the universe.

A paper describing their hypothesis was published June 1 in the early online edition of the Proceedings of the National Academy of Science.

Earth maintains its surface temperatures through the greenhouse effect. Although the planet's greenhouse gases—chiefly water vapor, carbon dioxide, and methane-have become the villain in global warming scenarios, they're crucial for a habitable world, because they act as an insulating blanket in the atmosphere that absorbs and radiates thermal radiation, keeping the surface comfortably warm.

As the sun has matured over the past 4.5 billion years, it has become both brighter and hotter, increasing the amount of solar radiation received by Earth, along with surface temperatures. Earth has coped by reducing the amount of carbon dioxide in the atmosphere, thus reducing the warming effect. (Despite current concerns about rising carbon dioxide levels triggering detrimental climate change, the pressure of carbon dioxide in the atmosphere has dropped some 2,000-fold over the past 3.5 billion years; modern, man-made increases in atmospheric carbon dioxide offset a fraction of this overall decrease.)

The problem, says Joseph L. Kirschvink, the Nico and Marilyn Van Wingen Professor of Geobiology at Caltech and a coauthor of the PNAS paper, is that "we're nearing the point where there's not enough carbon dioxide left to regulate temperatures following the same procedures."

Kirschvink and his collaborators Yuk L. Yung, a Caltech professor of planetary science, and graduate students King-Fai Li and Kaveh Pahlevan, say that the solution is to reduce substantially the total pressure of the atmosphere itself, by removing massive amounts of molecular nitrogen, the largely nonreactive gas that makes up about 78 percent of the atmosphere. This would regulate the surface temperatures and allow carbon dioxide to remain in the atmosphere, to support life, and could tack an additional 1.3 billion years onto Earth's expected lifespan.

In the "blanket" analogy for greenhouse gases, carbon dioxide would be represented by the cotton fibers making up the blanket. "The cotton weave may have holes, which allow heat to leak out," explains Li, the lead author of the paper.

"The size of the holes is controlled by pressure," Yung says. "Squeeze the blanket," by increasing the atmospheric pressure, "and the holes become smaller, so less heat can escape. With less pressure, the holes become larger, and more heat can escape," he says, helping the planet to shed the extra heat generated by a more luminous sun.

Strikingly, no external influence would be necessary to take nitrogen out of the air, the scientists say. Instead, the biosphere itself would accomplish this, because nitrogen is incorporated into the cells of organisms as they grow, and is buried with them when they die.

In fact, "this reduction of nitrogen is something that may already be happening," says Pahlevan, and that has occurred over the course of Earth's history. This suggests that Earth's atmospheric pressure may be lower now than it was earlier in the planet's history.

Proof of this hypothesis may come from other research groups that are examining the gas bubbles formed in ancient lavas to determine past atmospheric pressure: the maximum size of a forming bubble is constrained by the amount of atmospheric pressure, with higher pressures producing smaller bubbles, and vice versa.

If true, the mechanism also would potentially occur on any extrasolar planet with an atmosphere and a biosphere.

"Hopefully, in the future we will not only detect earth-like planets around other stars but learn something about their atmospheres and the ambient pressures," Pahlevan says. "And if it turns out that older planets tend to have thinner atmospheres, it would be an indication that this process has some universality."

Adds Yung: "We can't wait for the experiment to occur on Earth. It would take too long. But if we study exoplanets, maybe we will see it. Maybe the experiment has already been done."

Increasing the lifespan of our biosphere—from roughly 1 billion to 2.3 billion years—has intriguing implications for the search for life elsewhere in the universe. The length of the existence of advanced life is a variable in the Drake equation, astronomer Frank Drake's famous formula for estimating the number of intelligent extraterrestrial civilizations in the galaxy. Doubling the duration of Earth's biosphere effectively doubles the odds that intelligent life will be found elsewhere in the galaxy.

"It didn't take very long to produce life on the planet, but it takes a very long time to develop advanced life," says Yung. On Earth, this process took four billion years. "Adding an additional billion years gives us more time to develop, and more time to encounter advanced civilizations, whose own existence might be prolonged by this mechanism. It gives us a chance to meet."

The work described in the paper, "Atmospheric Pressure as a Natural Regulator of the Climate of a Terrestrial Planet with Biosphere," was funded by NASA and the Virtual Planetary Laboratory at Caltech.

Kathy Svitil

DOE Names Caltech Professor as Director of EFRC Focusing on Light-Material Interactions

Caltech also picked to partner in three additional EFRCs

PASADENA, Calif.--The U.S. Department of Energy (DOE) Office of Science has announced that it will fund the creation of 46 Energy Frontier Research Centers (EFRCs) over the next five years, including one that will be housed at the California Institute of Technology (Caltech). That EFRC will be headed by Harry Atwater, the Howard Hughes Professor and professor of applied physics and materials science.

"It is essential and very appropriate for a place like Caltech to serve as an intellectual center for fundamental scientific research in solar energy," says Atwater. "We have programs that support work on photovoltaic devices, but the Energy Frontier Research Center will address fundamental optical science issues relevant to solar energy. It's the kind of center that is best suited to our strengths."

In addition, Caltech researchers will partner with three additional EFRCs at other institutions.

According to Ares Rosakis, chair of Caltech's Division of Engineering and Applied Science, "Radical new approaches to harnessing solar energy are at the heart of many efforts here at Caltech to help contribute to the world's energy infrastructure with innovative, sustainable, core technologies. This new center brings Caltech one step closer to our goal of providing the resources necessary for some of the best minds in the country to lay the groundwork for a new energy economy."

This $777 million program is a major effort to accelerate the scientific breakthroughs needed to build a new 21st-century economy, the White House said in announcing the initiative. The 46 new EFRCs, which will each be funded at $2-5 million per year for a planned initial five-year period, will be established at universities, national laboratories, nonprofit organizations, and private firms across the nation.

Supported in part by funds made available under President Obama's American Recovery and Reinvestment Act, the EFRCs will bring together groups of leading scientists to address fundamental issues in fields ranging from solar energy and electricity storage to materials sciences, biofuels, advanced nuclear systems, and carbon capture and sequestration.

The EFRCs were selected from a pool of some 260 applications received in response to a solicitation issued in 2008 by the DOE's Office of Science. Over 110 institutions from 36 states plus the District of Columbia will be participating in the EFRC research. In all, the EFRCs will involve nearly 700 senior investigators and employ, on a full- or part-time basis, over 1,100 postdoctoral associates, graduate students, undergraduate students, and technical staff. Roughly a third of these researchers will be supported by Recovery Act funding.

Atwater's EFRC, entitled "Light Material Interactions in Energy Conversion," will include collaborations with scientists at Lawrence Berkeley National Laboratory and the University of Illinois, and some of the work will be done at the Molecular Foundry at Lawrence Berkeley National Laboratory.

"The goal of the center is to understand how to sculpt and mold the flow of light through materials," Atwater explains. "By that I mean we will be working to design structures at the nanoscale that steer and change the speed of light to optimally convert sunlight to electricity and chemical fuels."

The three additional EFRCs that will be partnering with Caltech researchers include

  • Rational Design of Innovative Catalytic Technologies for Biomass Derivative Utilization (headed by the University of Delaware), with Mark Davis, the Warren and Katharine Schlinger Professor of Chemical Engineering at Caltech
  • EFRC for Solid State Lighting Science (headed by Sandia National Laboratories), with Harry Atwater
  • Center for Catalytic Hydrocarbon Functionalization (headed by the University of Virginia), with William Goddard, the Charles and Mary Ferkel Professor of Chemistry, Materials Science, and Applied Physics at Caltech

# # #

Lori Oliwenstein

Caltech Scientists Create New Enzymes for Biofuel Production

Enzymes are important step toward cheaper biofuels

Researchers at the California Institute of Technology (Caltech) and world-leading gene-synthesis company DNA2.0 have taken an important step toward the development of a cost-efficient process to extract sugars from cellulose--the world's most abundant organic material and cheapest form of solar-energy storage. Plant sugars are easily converted into a variety of renewable fuels such as ethanol or butanol.

In a paper published this week in the early edition of the Proceedings of the National Academy of Sciences, Frances H. Arnold, the Dick and Barbara Dickinson Professor of Chemical Engineering and Biochemistry at Caltech, and her colleagues report the construction of 15 new highly stable fungal enzyme catalysts that efficiently break down cellulose into sugars at high temperatures. Previously, fewer than 10 such fungal cellobiohydrolase II enzymes were known. In addition to their remarkable stabilities, Arnold's enzymes degrade cellulose over a wide range of conditions.

Biofuels are made by converting renewable materials--for example, corn kernels, wood chips left over from pulp and paper production, prairie grasses, and even garbage--into fuels and chemicals. Most biofuels used today are made from the fermentation of starch from corn kernels. That process, although simple, is costly because of the high price of the corn kernels themselves.

Agricultural waste, such as corn stover (the leaves, stalks, and stripped cobs of corn plants, left over after harvest), is cheap. These materials are largely composed of cellulose, the chief component of plant-cell walls. Cellulose is far tougher to break down than starch. An additional complication is that while the fermentation reaction that breaks down corn starch needs just one enzyme, the degradation of cellulose requires a whole suite of enzymes, or cellulases, working in concert.

The cellulases currently used industrially, all of which were isolated from various species of plant-decaying filamentous fungi, are both slow and unstable, and, as a result, the process remains prohibitively expensive. "Even a two-fold reduction in their cost could make a big difference to the economics of renewable fuels and chemicals," says Arnold.

Arnold and Caltech postdoctoral scholar Pete Heinzelman created the 15 new enzymes using a process called structure-guided recombination. Using a computer program to design where the genes recombine, the Caltech researchers "mated" the sequences of three known fungal cellulases to make more than 6,000 progeny sequences that were different from any of the parents, yet encoded proteins with the same structure and cellulose-degradation ability.

By analyzing the enzymes encoded by a small subset of those sequences, the Caltech and DNA2.0 researchers were able to predict which of the more than 6,000 possible new enzymes would be the most stable, especially under higher temperatures (a characteristic called thermostability).

Thermostability is a requirement of efficient cellulases, because at higher temperatures--say, 70 or even 80 degrees Celsius--chemical reactions are more rapid. In addition, cellulose swells at higher temperatures, which makes it easier to break down. Unfortunately, the known cellulases from nature typically won't function at temperatures higher than about 50 degrees Celsius.

"Enzymes that are highly thermostable also tend to last for a long time, even at lower temperatures," Arnold says. "And, longer-lasting enzymes break down more cellulose, leading to lower cost."

Using the computer-generated sequences, coauthor Jeremy Minshull and colleagues from DNA2.0 of Menlo Park, California, synthesized actual DNA sequences, which were transferred into yeast in Arnold's laboratory. The yeast produced the enzymes, which were then tested for their cellulose-degrading ability and efficiency. Each of the 15 new cellulases reported in the PNAS paper was more stable, worked at significantly higher temperatures (70 to 75 degrees Celsius), and degraded more cellulose than the parent enzymes at those temperatures.

"This is a really nice demonstration of the power of synthetic biology," Arnold says. "You can rapidly generate novel, interesting biological materials in the laboratory, and you don't have to rely on what you find in nature. We just emailed DNA2.0 sequences based on what we pulled out of a database and our recombination design, and they synthesized the DNA. We never had to go to any organism to get them. We never touched a fungus."

Next, the researchers plan to use the structure-guided recombination process to perfect each of the half-dozen or so cellulases that make up the soup of enzymes required for the industrial degradation of cellulose. "We've demonstrated the process on one of the components. Now we have to create families of all of the other components, and then look for the ideal mixtures for each individual application," Arnold says, with the ultimate goal of creating a cost-efficient recipe for cellulosic biofuel.

"If you think about it, energy is the biggest industry there is," Arnold says. "If we can replace foreign oil with renewable biofuels, that's an enormous contribution. And that replacement is slow right now because these enzymes are just too expensive."

The work in the paper, "A Family of Thermostable Fungal Cellulases Created by Structure-Guided Recombination," was supported by the Army-Industry Institute for Collaborative Biotechnologies and the Caltech Innovation Institute.

Kathy Svitil
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Caltech Scientists Lead Deep-Sea Discovery Voyage

Research mission uncovers several new species and thousands of fossilized coral samples.

PASADENA, Calif.--Scientists from the California Institute of Technology (Caltech) and an international team of collaborators have returned from a month-long deep-sea voyage to a marine reserve near Tasmania, Australia, that not only netted coral-reef samples likely to provide insight into the impact of climate change on the world's oceans, but also brought to light at least three never-before-seen species of sea life.

"It was truly one of those transcendent moments," says Caltech's Jess Adkins of the descents made by the remotely operated submersible Jason. Adkins was the cruise's lead scientist and is an associate professor of geochemistry and global environmental science at Caltech. "We were flying--literally flying--over these deep-sea structures that look like English gardens, but are actually filled with all of these carnivorous, Seuss-like creatures that no one else has ever seen."

The voyage on the research vessel RV Thompson explored the Tasman Fracture Commonwealth Marine Reserve, southwest of Tasmania. The voyage was funded by the National Science Foundation and was the second of two cruises taken by the team, which included researchers from the United States--including scientists from Caltech and the Woods Hole Oceanographic Institution in Massachusetts, which owns and operates the submersible Jason--and Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO). The first of those voyages was taken in January 2008, with this most recent one spanning 33 days from mid-December 2008 through mid-January 2009.

Up until now, the area of the reef the scientists were exploring--called the Tasman Fracture Zone--had only been explored to a depth of 1,800 meters (more than 5,900 feet). Using Jason, the researchers on this trip were able to reach as far down as 4,000 meters (well over 13,000 feet).

"We set out to search for life deeper than any previous voyage in Australian waters," notes scientist Ron Thresher from CSIRO's Climate Adaptation and Wealth from Oceans Flagships.

The cruise had two main goals, says Adkins. One was to try to use deep-sea corals to reconstruct the paleoclimate--with an emphasis on the changes in climate over the last 100,000 years--and to understand the fluctuations in CO2 found in the ice-core records. Investigators also wanted to look at changes in the ocean over a much smaller slice of time--the past few hundred to one thousand or so years. "We want to see what's happened to the corals over the Industrial Revolution timescale," says Adkins. "And we want to see if we can document those changes."

The second goal? "Simply to document what's down there," says Adkins.

"In one sense, the deep ocean is less explored than Mars," he adds. "So every time you go to look down there you see new things, magical things."

Among the "magical things" seen on this trip were

  • a new species of carnivorous sea squirt that "looks and behaves like a Venus fly trap," says Adkins;
  • new species of barnacles (some of which Adkins says may even belong to an entirely new family); and
  • a new species of sea anemone that Adkins calls "the bane of our existence," because it looks just like the coral they were trying to collect.

The sea anemone was particularly vexing for the researchers, because they were hoping to find deep-sea (or abyssal) samples of the fossilized coral, but were unable to find the coral much below 2,400 meters (nearly 7,800 feet). The look-alike sea anemone, on the other hand, kept popping up all over the place on the deep-sea floor, raising--and then dashing--the scientists' hopes.

This carnivorous sea squirt was one of the new species seen during the voyage of the RV Thompson.
Credit: Advanced Imaging and Visualization Laboratory, WHOI/Jess Adkins, Caltech

"Not being able to find the coral down deeper was our single biggest disappointment on the trip," says Adkins.

Still, the 10,000-plus samples collected will help the researchers begin their work of deciphering just what has been happening to the ocean throughout the centuries of climate change, and during and between glacial cycles. First up: dating the fossils collected on this trip in order to determine which slice of history they came from.

"The deep ocean is part and parcel of these rapid climate changes," says Adkins. "These corals will be our window into what their impact is on climate, and how they have that impact. The info is there; now we just have to unpack it."

Further funding for the research came from CSIRO, the Commonwealth Environmental Research Facilities' Marine Biodiversity Hub, and the Australian Department of the Environment, Water, Heritage and the Arts.

Lori Oliwenstein


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