Using a laser beam to chisel light passageways through exotic semiconducting material, researcher Evelyn Hu helped secure this year’s highest UCSB faculty honor.
A committee of faculty chose Hu last month to receive the Faculty Research Lectureship Award, given each year to recognize outstanding work by a specific UCSB researcher. As part of receiving this year’s award, Hu will give a lecture titled “Michelangelo’s Laser: Sculpting Form into Function” on May 24 at 4 p.m. in the Engineering Sciences Building, room 1001. The lecture will focus on Hu’s recent work of creating very small light passageways a few hundred times smaller than the diameter of a human hair. At such a microscopic level, light behaves differently than in large everyday devices like a flashlight. The implications for tiny light passageways include developing extremely fast computers and communication devices that could make current technology obsolete.
Hu has been at UCSB since 1984, and has been co-director of the California NanoSystems Institute, a collaborative research center supported by UCLA and UCSB, since its inception in 2000. Hu also gained industry experience at Bell Labs in the late 1970s before coming to UCSB.
“I have been working on nanosystems, perhaps before they were even called nanosystems,” Hu said. “These are fundamental studies, but they have important engineering applications.”
Some of those applications include building computer chips that could make new desktop computers very small, consume less power and run significantly faster than today’s best machines. To build these next generation computer chips, Hu said that researchers will need to understand the nature of how electricity and light flow through materials at an extremely microscopic scale. She said the title of her lecture alludes to the inspiration needed to construct these tiny structures.
“The reason for the title is that in physical sciences, there is an art to making structures,” Hu said. “Michelangelo was a great painter and a great sculptor. Many thought he could look at a piece of marble and see the statue within.”
Similarly, Hu said that it helps to envision how a material in the laboratory might be carved with a laser into strips just a few hundred nanometers wide – less than 100 atoms across. Some of the materials that Hu works with are semiconductors, materials that can be made to allow or restrict the flow of electricity. When cut up and assembled into tiny shapes, electricity flowing in the ultra-small semiconductor does not behave the same way as in conventional electrical circuits, thus leading to more advanced circuitry.
“The beauty is in its optical or electrical performance,” Hu said. “It’s not like taking a chisel and removing marble.”
One of Hu’s Ph.D. electrical engineering students, Kevin Hennessy said that a current research project is to construct circuits that use light instead of electric current to send signals. The field is known as nanophotonics, and could potentially revolutionize the field of computer chips.
“Sometimes [nanophotonics] is refereed to as nanotechnology,” Hennessy said. “This is sculpting and forming matter to make very small devices for future applications in computers and communications and things like that. In this group we focus on designing and fabricating the building blocks that will be essential components for next generation computer systems and communication systems.”
Though the first applications that may use the nanophotonic building blocks are computers and communications, the technology is not ready to be implemented in these fields yet, Hennessy said. Researchers at UCSB are currently working on this issue of building computer chips that use light instead of electricity, but there are still manufacturing issues that mean nanophotonic products cannot be produced commercially yet.
“What we understand now about the devices is leaps and bounds ahead of where we where when I started four years ago,” Hennessy said. “For these sorts of technologies to become prevalent in industry, it will take a while just because the cost of fabrication is still very high.”
Another of Hu’s research interests is to use biological substances to help build conventional computer chips. Yan Gao, one of Hu’s postdoctoral students at the UCSB Institute for Collaborative Biotechnologies, said Hu has directed research into using bacteria to help cut a block of raw semiconductor into a working circuit.
“The cool thing about Evelyn’s project is that she is trying to combine the conventional [chip making techniques] into the biological technology,” Gao said. “The main goal is to overcome the challenge of reducing the size of [internal chip components].”
Another of Hu’s postdoctoral students, Elaine Haberer, said one of Hu’s most remarkable traits is the ability to join very different research fields.
“She always finds a connection between them even though they seem to be very different things,” Haberer said.