Michigan Engineering leads Department of Defense study on heat-to-electricity conversion
In early May, the United States Department of Defense granted $6.25 million to a team of University of Michigan researchers to study heat transfer at the nanoscale. The team aims to further this area of research for uses like heat-to-electricity conversion and utilizing LEDs for cooling.
Michigan Engineering is leading Massachusetts Institute of Technology, Purdue University, Stanford University and Yale University in this study. The team is headed by mechanical engineering professors Pramod Reddy and Edgar Meyhofer.
In a series of papers from 2016 to 2018, Reddy and Meyhofer’s research team conducted a new approach to thermal radiation. Through extensive work on energy flow at the nanoscale, they demonstrated energy transfer rates for objects separated by nanoscale gaps that can reach speeds up to 1,000 times faster than those predicted by Max Planck 120 years ago. They also have applied this in converting heat to electricity.
Additionally, they have demonstrated how to use LEDs for cooling devices situated nanometers away. This cooling effect discovered by Reddy’s and Meyhofer’s team has the potential to produce cooling equivalent to the power of sunshine on Earth’s surface.
Reddy said the main point of their research is to reveal the science of nanoscale energy conversion using photons, or particles of light.
“This is a basic science program, which is trying to understand new things that happen at the nanoscale,” Reddy said. “(In the) long-term, you are trying to leverage those to create (new) energy conversion technologies.”
Future smartphones and other new technologies may implement the team’s findings. While the size of devices continues to decrease, the amount of computing power wedged inside of them has been increasing. These changes eliminate heat from the microprocessor, thus restricting how much power can be stuffed inside a small device.
Reddy said their research findings could even be applied to future refrigeration methods.
“(This study) is aiming to understand how one can take advantage of new processes … and nanoscience and nanotechnology and try to make useful technologies out of it,” Reddy said. “For example, how to convert heat to electricity or to develop new ways of refrigeration, which are very different from the traditional refrigerator."
Army Research Office of the U.S. Army Combat Capabilities Development Command’s Army Research Laboratory, also known as CCDC, awarded the grant as part of the Department of Defense Multidisciplinary University Research Initiative program. MURI contains teams of researchers investigating important topics overlapping multiple traditional science and engineering disciplines, such as physics and mechanical engineering in the study.
In a press release, Dr. Pani Varanasi, chief of the Materials Science Division of the Army Research Office, said this research could tremendously benefit soldiers and army technology in the future.
“Advancements in near-field thermo-photovoltaics will enable soldiers to harness high efficiency power from any heat source on the battlefield,” Varanasi said. “This research may also spur the development of near-field-based thermal diodes and thermal transistors that could enable innovative thermal-based computing for niche future applications, as well as in thermal management of high-power electronics.”
According to Reddy, this study has thus far involved close collaboration between the research team members, which has been advantageous.
“What this kind of effort proves is that long-term collaborations can lead to solving important problems when people work closely,” Reddy said. “This project kind of highlights how this is very effectively done.”
Engineering sophomore Grace Dillon stressed the future significance of these findings and their potential effect on energy as a whole.
“This research takes a common and widely available resource — heat — and finds a way to efficiently create something useful out of it — energy,” Dillon said. “At the same time, research in this area works to remove obstacles from future microprocessor technology, which could greatly impact upcoming innovation.”
Engineering sophomore Mira Rodney said this project is important for Michigan Engineering students as it will provide them with an opportunity to study the principles of energy on a nanoscale.
“There are some students who wish to study this type of research and wish to make a difference in the world,” Rodney said. “This grant will be the first step to allowing those students to reach their goals”
Because the government recognized awarded the University this grant, Rodney said she believes this signifies a recognition of the necessity to have students involved in research.
“I think it is interesting that the Department of Defense is allowing (the University) to study energy principles that will help the country rather than just doing research for a class or other reasons,” Rodney said.
Studying heat-to-electricity conversion and electronic cooling techniques may have far-reaching impacts on various fields and areas of study, Dillon suggested.
“As an engineering student at U-M, it’s really exciting to see the University be at the forefront of this innovation,” Dillon said.