September 30, 2008
RTI International Scientists to Develop Next-Generation Thermoelectric Materials, Applications
RESEARCH TRIANGLE PARK, N.C. -– Scientists at RTI are teaming up with several leading universities and a major aerospace company to develop the next generation of thermoelectric materials – revolutionary technologies that can efficiently convert heat differentials or waste heat into electrical energy for a wide range of applications.
The research, funded by two separate contracts with U.S. Department of Defense organizations, seeks to advance the state of the art in thermoelectric (thermal-to-electric) power conversion materials, devices and applications.
For the first effort, funded by the Defense Sciences Office of the Defense Advanced Research Projects Agency (DARPA), RTI has received $1 million for the initial 12 months of work. The total value, if all phases of the development program are completed, could be up to $5.8 million. As part of this project, the RTI-led team will develop new materials and devices that operate across a broad temperature range – from 0o C to about 700o C, to achieve the goal of near 30 percent energy conversion efficiencies.
Achieving such efficiencies would lead to dramatic applications in DoD Army, Navy, and Air Force systems as well as in the commercial arena. For example, such a technology can pave the way for improving the fuel-efficiency of automobiles by almost 20 percent and can also lead to efficient energy harvesting for electronics.
"Since about 60 percent of the world’s energy from fossil fuels is wasted as heat, there is a considerable interest in converting even a fraction of this heat into useful electric power for significant savings in overall fuel-efficiency," said Rama Venkatasubramanian, Ph.D., principal investigator for the project at RTI and director of RTI’s Center for Solid State Energetics. "We are excited about the opportunity to collaborate with several outstanding research universities in this new DARPA program to make further advancements in nanoscale thermoelectric materials."
RTI’s research partners include California Institute of Technology, North Carolina State University, Purdue University, Ames Lab of Iowa State, University of California Riverside and University of Delaware as well as United Technologies Research Corporation.
This effort builds on a previously DARPA-funded initiative called Direct Thermal Energy Conversion (DTEC) in which RTI scientists achieved major improvements in device efficiencies and power densities for thermoelectric power conversion as well as demonstrated several early-stage applications of the technology.
The developments from this DTEC program already offer opportunities in wide-ranging applications from sensor power to increased fuel-efficiency in diesel generators to replacing heavy auxiliary power in many aerospace systems.
The second project worth $1.3 million over three years, seeks to improve the fuel-efficiency of the U.S. Army’s portable diesel generators using thermoelectric technologies. It is sponsored by the Strategic Environmental Research and Development Program (SERDP). SERDP is the Department of Defense’s environmental science and technology program, which is planned and executed in partnership with the U.S. Environmental Protection Agency and the U.S. Department of Energy.
"We are targeting a fuel-efficiency improvement of as much as 10 percent in diesel generators in this SERDP program, leveraging some of the DTEC-developed thermoelectric materials and device technologies," said Chris Caylor, Ph.D., of RTI, the principal investigator of this SERDP project.
RTI’s previous research in nanoscale superlattice materials, developed with DARPA support, resulted in a spin-off of the thermoelectric technology company, Nextreme Thermal Solutions, in December 2004. As part of the transaction, Nextreme acquired certain intellectual property rights in thin film thermoelectric from RTI. Since 2004, Nextreme has developed manufacturing methods and begun sampling thin-film thermoelectric modules with a variety of commercial customers in optoelectronics, electronics cooling and power generation applications.
Meanwhile, scientists at RTI have continued to advance the nanoscale materials as well as other materials and device technologies to develop power generation technologies for a wide range of temperatures and heat sources.