Researchers exploring new methods to increase computer-chip performance

The work of a group of researchers at the University’s Institute for Biophysical Dynamics may prevent a repeal of Moore’s Law, a computer-industry standard that states computer chips should double in power approximately every 18 months.

Industry experts, including Intel co-founder Gordon Moore, who formulated the law, say the physical limits and rising cost of fabrication methods will end the rapid, exponential increase in computer-chip performance within the next 20 years—unless, of course, researchers at the IBD develop a viable new approach to the construction of computer devices.

A new approach might involve the manipulation of light instead of electric current and a template of some new biologically inspired material instead of silicon. “Will this become the commercially viable way in which we’re going to produce computers down the road? I don’t know. The odds are against such things happening,” said Norbert Scherer, IBD Co-director and Professor in Chemistry. But Scherer and four of his colleagues have begun to investigate the possibilities with a $2 million grant from the W.M. Keck Foundation in Los Angeles.

“If we can actually manipulate light in a sensible fashion, this would result in an astronomical increase in computational ability, because we could actually do calculations in parallel at the speed of light,” Scherer said.

Susan Lindquist, the Albert D. Lasker Professor of Medical Sciences in Molecular Genetics & Cell Biology and an investigator in the University’s Howard Hughes Medical Institute; David Grier and Heinrich Jaeger, both Associate Professors in Physics; and Milan Mrksich, Assistant Professor in Chemistry, are working with Scherer on the project.

The project is one of the first initiatives of the IBD, which was founded in 1998 to spur research that transcends the boundaries of traditional scientific disciplines. Lindquist and Jaeger are not members of the IBD, illustrating, Scherer said, how the institute provides the environment and motivation to pursue projects without regard to traditional intellectual boundaries.

“Our goal at the institute is to foster a culture of explicitly collaborative interdisciplinary research and not to be a collection of individual investigators doing their own things,” Scherer said.

“In recent years, interdisciplinary research and cross-trained investigators have had tremendous impact, as judged by the disproportionate number of Nobel Prizes awarded to physicists who were working in and actually creating the fields of structural and molecular biology,” Scherer said. “Similarly, advances in structural and molecular biology have impacted chemistry in areas of natural-product synthesis and drug design.”

The Keck project resulted from conversations Scherer had with Jaeger, who studies electronic transport in metallic structures, and Lindquist, who investigates how proteins cause disease by altering their conformation and changing shape.

There is an amazing similarity between the electron microscope images of a compound decorated with tiny metal dots, which Jaeger has organized into parallel arrays by applying an electric field, and the images of amyloid fibers, the proteins believed to play a key role in Alzheimer’s disease, with which Lindquist works.

Lindquist can completely alter the structure and function of the fibers by changing their amino acids.

Scherer wondered if it might be possible to make a hybrid of the two systems that could be fashioned into a useful new technology.

“Can we transmit light into these fibers that are much smaller than the wavelength of light? And if so, can we then also do some computational operation on them?” Scherer asked.

A more conservative outcome from these approaches would be a new route to electrical wires and interconnects, Scherer added.

According to Gordon Moore’s Second Law, every generation of computer chips costs twice as much to develop as the last. Continued exponential growth in contemporary computing depends upon the photolithography methods that industry uses to transfer ever-shrinking circuit designs onto silicon wafers. But these current methods may soon become prohibitively expensive.

Taking advantage of nature’s own design offers one possible route to further miniaturization.

“Biological structures are intrinsically organized on scales of nanometers to microns. Bio-molecules allow us to create and assemble order on these same length scales,” Scherer said.

The amyloid fibers Lindquist works with would serve as the basic material onto which Jaeger would systematically add his tiny dots of gold. At five or 10 nanometers in diameter, these gold dots are smaller than the AIDS virus and smaller than any feature on a computer chip currently being produced.

Mrksich, who specializes in bio-organic chemistry, will bring to the project further chemical capabilities to manipulate biological structures, Scherer said. Grier will supply the laser-tweezer techniques that could help build a device with such small features. And Scherer will provide the methods for channeling light through materials on biotemplates and for measuring efficiency.

Although the actual creation of a device is years away, during the two-year Keck project, the team will develop the design rules they would need to build a device in the next research phase. “We really need to interact with computer scientists to make a device,” Scherer said. “If we tell them what we can make, maybe they can tell us what it might be useful for.”