So far researchers have had no luck finding alternative thermoelectric materials. But they have not yet tried high-throughput computational materials design. That will soon change. Starting this year, we will begin working with researchers at the California Institute of Technology and five other institutions to perform high-throughput searches for new thermoelectric materials. We intend to keep at it until we find the chemical compounds that could make those energy-saving, miracle-cooling technologies a reality.
The Golden Age of Materials Design
Our ability to access, search, screen and compare materials data in an automated way is in its infancy. As this field grows, what could it yield? We will venture a few guesses.
Many promising clean-energy technologies are just waiting for advanced materials to become viable. Photocatalytic compounds such as titanium dioxide can be used to turn sunlight and water into oxygen and hydrogen, which can then be processed into liquid fuels. Other photocatalysts can do the same thing with carbon dioxide. The dream is an “artificial leaf” that can turn sunlight and air into methanol-like liquid fuels we could burn in cars and airplanes [see “Reinventing the Leaf,” by Antonio Regalado; Scientific American, October 2010]. Researchers at the Joint Center for Artificial Photosynthesis, a U.S. Department of Energy research center, are using high-throughput methods to look for materials that could make this technology feasible.
What about finding new metal alloys for use in those cars and airplanes? Reducing a vehicle's weight by 10 percent can improve its fuel economy by 6 to 8 percent. U.S. industry already pours billions of dollars every year into research and development for metals and alloy manufacturing. Computer-guided materials design could multiply that investment. Significant advances in high-strength, lightweight and recyclable alloys would have a tremendous impact on the world economy through increased energy efficiency in transportation and construction.
Computing is another field in need of transformative materials. Recently we have seen many serious predictions that we are nearing the end of Moore's law, which says that computing power doubles roughly every two years. We have long known that silicon is not the best semiconductor. It just happens to be abundant and well understood. What could work better? The key is to find materials that can quickly switch from conducting to insulating states. A team at U.C.L.A. has made extremely fast transistors from graphene. Meanwhile a group at Stanford has reported that it can flip the electrical on/off switch in magnetite in one trillionth of a second—thousands of times faster than transistors now in use. High-throughput materials design will enable us to sort through these possibilities.
This list is much longer. Researchers are using computational materials design to develop new superconductors, catalysts and scintillator materials. Those three things would transform information technology, carbon capture and sequestration, and the detection of nuclear materials.
Computer-driven materials design could also produce breakthroughs that are hard to imagine. Perhaps we could invent a new liquid fuel based on silicon instead of carbon, which would deliver more energy than gasoline while producing environmentally benign reaction products such as sand and water. People have talked about the idea for decades, but no one has figured out a workable formula. High-throughput materials design could at least tell us if such a thing is possible or if we should focus our efforts elsewhere.
All of this is why we believe we are entering a golden age of materials design. Massive computing power has given human beings greater power to turn raw matter into useful technologies than they have ever had. It is a good thing, too. To help us deal with the challenges of a warming, increasingly crowded planet, this golden age cannot start soon enough.