Geoff Wehmeyer’s research group uses Rice’s electron microscopes to deepen understanding of nanoscale heat transfer and improve the performance of products ranging from transistors to light-emitting diodes and heat-assisted magnetic recording devices.
“The interfaces between materials are a major barrier to thermal management of nanotechnologies. Our goal is to probe the small-scale mechanisms of how heat flows across material junctions, which would allow engineers to achieve more efficient device performance,” said Wehmeyer, assistant professor of mechanical engineering (MECH) and recipient of a 2022 National Science Foundation (NSF) CAREER Award.
He was awarded a five-year, $535,934 grant for his proposal: “Nanoscale temperature mapping across interfaces using scanning transmission electron microscopy.”
CAREER Awards, among the most competitive issued by the NSF, are annually given to some 400 young scientists and engineers in support of “early career faculty who have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization.”
“By improving our basic understanding of nanoscale heat flow mechanisms across interfaces,” Wehmeyer said, “engineers could tailor the composition and structure of these interfaces to optimize cooling strategies. That could lead to improved device durability and efficiency.”
Currently, engineers find it difficult to evaluate the predictions of various interfacial heat transport theories at the nanoscale, partially because thermal experiments are not able to map temperature at the finest length scales of interest.
Wehmeyer proposes developing scanning transmission electron microscopy nano-thermometry experiments. By using atomic-scale calculations, researchers could better understand interfacial heat transport and offer high-resolution insight into relations between interface structure and thermal performance.
The CAREER Award will also support Wehmeyer’s collaborations with the Rice Office of STEM Engagement and Houston-area community colleges on summer research experiences for students and outreach events that promote career opportunities in nanotechnology and thermal management.
Wehmeyer earned his Ph.D. in MECH from the University of California, Berkeley, in 2018, and joined the Rice faculty the same year. In 2019, he was one of nine researchers in the U.S. selected to receive NASA’s Early Career Faculty Award from the Space Technologies Mission Directorate. Wehmeyer was also awarded a Sophia Meyer Farb Prize for Teaching by Rice’s Phi Beta Kappa chapter in 2021.
His Nanoscale Heat Transfer Lab includes two postdoctoral scholars, four doctoral students, a master’s student and six undergraduate researchers.