Two faculty members awarded grants to pursue innovative energy research


Michael McGehee


Yi Cui

Competition for federal funding is fierce, and the odds seem even slimmer for unconventional research, regardless of its potential. But two Stanford professors will receive awards to finance their work over the next year for just that kind of outside-of-the-box thinking.

"We recognize the difficulty faculty can have, particularly early in their careers, in gaining funding for high-risk, unproven projects," said Katherine "KT" Moortgat. She is a partner at Mohr Davidow Ventures, which is sponsoring the $75,000 grants. "The MDV award aims to enable new possibilities for these extraordinary faculty innovators."

Assistant Professor Yi Cui and Associate Professor Michael McGehee, both in materials science and engineering, submitted proposals detailing projects with, according to MDV, "potential to disrupt current thinking in their field or provoke new areas of research." The Menlo Park-based venture capital firm announced the four winners of its inaugural Innovators Award (the other two are from the University of California-Berkeley) on Nov. 15.

Cui has big ideas he hopes will improve rechargeable lithium ion batteries like those found in cell phones, laptops and other portable electronic devices. But at the root of his big idea is something very small: tiny silicon filaments called nanowires that efficiently transmit charge.

"We are talking about an energy density two to three times higher than current technology, or even higher," Cui said. "Basically, we want to change the fundamental mechanism of how the battery works."

Silicon nanowires have a much higher capacity for energy than traditional carbon, at least in theory, Cui said, so they should allow a battery to hold more energy.

"The current technology is great, but we want to move it one big step further," he said. "If you charge up your laptop battery, you can use it for four hours. What if you want to use if for 24 hours? Say you're taking an international flight, and you aren't able to recharge it."

Because nanowires are so small—with a diameter 1,000 times smaller than the thickness of a sheet of paper—and there are many of them present, they provide greater total surface area to contact the chemicals in a battery than would a larger, single electrode. This increase in the area of the electrode transmitting charge should result in greater power.

McGehee is attacking the energy problem from another angle. For the past seven years, he has been studying ways to make solar cells from organic materials—that is, polymers.

"The general advantage of organic electronics is you can make large area devices at low cost," said McGehee. "Solar cells are an application where you need to cover a very large area at low cost."

A laptop, for example, uses about 100 watts of power, and to collect that from the sun would require a solar cell a square meter in area—about the size of a four-person dinner table. Imagine, then, how large an area would be required to begin to contribute to the country's energy needs as a whole. Clearly, there needs to be a more economical method of producing solar cells.

McGehee is interested in technology similar to a roll-to-roll coating machine—like the ones used to print newspapers—to roll out solar cells and increase the efficiency of production.

"We're hoping to cut the costs by a factor of five to 10," McGehee said.

Several of his students plan to start up companies after graduating, so they hope to benefit from collaboration with the venture capital firm. In turn, MDV will have access to emerging technologies and potential areas for investment.

And for McGehee and Cui, of course, it's important to have the support to try something new.

"At this point, the federal government would probably not fund this project because it's not clear we're going to be able to get it to work," McGehee said of his specific plans for the grant. "But it's nice to be able to try it because this new idea will be really exciting if it does work."

John Cannon is a science-writing intern at the Stanford News Service.