Qing Hao, assistant professor in the University of Arizona Department of Aerospace and Mechanical Engineering, has received a 2017 Faculty Early Career Development Award of $506,353 from the National Science Foundation to continue his research on nanoscale energy transport. The award is the NSF’s highest honor for junior faculty members.
Hao is working toward development of ways to facilitate or impede heat transfer in a polycrystalline thin film or bulk material, typically made up of grains smaller than one hundredth the width of a human hair. These nanostructured materials are used widely in electronic devices, solar cells, optical technology, thermal protection layers, thermoelectric power generation, refrigeration, and in structural materials for aircraft and automobiles, buildings and roads.
In the five-year NSF project, which began March 1, Hao is focusing on thermal transport across grain boundaries of a polycrystalline material. Grain boundaries are two-dimensional defects that restrict heat transfer in nanomaterials by scattering phonons, quasi-particles that represent vibrational waves and transmit sound and heat.
“Previous studies on the role of grain boundaries in thermal conductivity have analyzed the averaged impact of millions of grain boundaries across the whole material,” said Hao. “Our study will be the first to analyze in detail how phonons interact with a single grain boundary.”
NSF Career Awards include a STEM outreach component. With his students, Hao is developing an educational plan for local high-school and middle-school students participating in the UA’s Mathematics, Engineering, Science Achievement, or MESA, program.
“Our goal is to teach these students about nanotechnology in their own lives, while increasing their interest in STEM careers and encouraging them to better prepare for college,” he said.
The Career Award is the latest of several efforts for Hao, who is also working on discovering new materials for energy-related applications. As a doctoral student at MIT, he coauthored a Science paper on high-performance nanostructured bismuth antimony telluride bulk alloys, which led to a 2008 R&D 100 award. Four years after joining the UA faculty, he received an Air Force Office of Scientific Research Young Investigator Award -- one of only 57 nationwide in 2015 -- for his research on graphene, the strongest, thinnest and most heat-conductive material known.
“Career: Thermal Transport Studies of Individual Grain Boundaries within Nanostructured Materials” is supported by the National Science Foundation under grant No. 1651840.