AME Department Seminar: Energy transfer in nanoscale gaps and atomic junctions


Prof. Pramod Reddy
Departments of Mechanical Engineering and Materials Science and Engineering
University of Michigan, Ann Arbor.


Understanding radiative and conductive heat transfer in nanoscale gaps and devices is of considerable interest for creating novel energy conversion and information processing devices. In this talk, I will first describe ongoing efforts in our group to experimentally elucidate nanoscale radiative heat transfer. Specifically, I will present our recent experimental work where we have addressed the following questions: Can existing theories accurately describe radiative heat transfer in single nanometer sized gaps1? Can radiative thermal conductances that are orders of magnitude larger than those between blackbodies be achieved2? In order to address these questions we have developed a variety of instrumentation including novel nanopositioning platforms and microdevices, which will also be described. In addition, I will also discuss recent experimental work3 from our group where we made first measurements of heat transport and Peltier cooling at the atomic scale to elucidate the novel quantum transport properties that arise in atomic and molecular junctions. Finally, I will briefly outline how these technical advances can be leveraged for future investigations of nanoscale heat transport and near-field thermophotovoltaic energy conversion.

[1] K. Kim, et al. “Radiative heat transfer in the extreme near-field”, Nature (2015).
[2] B. Song et al., “Radiative heat conductance between dielectric and metallic parallel plates at nanoscale gaps”, Nature Nanotechnology (2016); D. Thompson et al., “Hundred-fold enhancement in far-field radiative heat transfer over the blackbody limit”, Nature (2018).
[3] L. Cui, et al. “Quantized thermal transport in single-atom junctions”, Science (2017); L. Cui et al., “Peltier cooling in molecular junctions”, Nature Nanotechnology (2017)


Prof. Pramod Reddy received a B. Tech and M. Tech in Mechanical Engineering from the Indian Institute of Technology, Bombay in 2002, and a Ph.D. in Applied Science and Technology from the University of California, Berkeley in 2007. He was a recipient of the NSF CAREER award in 2009, the DARPA Young Faculty Award in 2012, and the Young Alumnus Achiever Award from IIT Bombay in 2017. He is currently an associate professor in the departments of Mechanical Engineering and Materials Science and Engineering at the University of Michigan, Ann Arbor.

Host: Tengfei Luo (