Welcome!

We are a research group in the Mechanical Engineering department at Caltech, led by Professor Austin Minnich. Our lab's research focus is on understanding and engineering nanoscale heat transport for applications in the energy field like thermoelectric waste heat recovery. We use a variety of experimental and theoretical techniques to investigate nanoscale transport processes, with a particular emphasis on ultrafast optical techniques. We invite you to look at the website for more details about our work and facilities.



News

Nick successfully defends his thesis. Congrats! Apr 13, 2018

Xiangwen and Lina have moved on to their next positions. Congrats! Jan 13, 2018

Alex passes quals. Congrats! Sept 21, 2017

Benoit has moved on to his next position. Congrats! June 1, 2017

Zoila, Peishi, and Erika successfully pass candidacy. Congrats! May 31, 2017

Chengyun's work on phonon transmission spectra was publish in Physical Review B. May 15, 2017

Nate, Taeyong, and Junlong gave talks at the 2017 Spring MRS Conference. April 22, 2017

Lina publishes her work on low frequency thermal modes in Si and SiGe in Scientific Reports. March 14, 2017

Congrats to Austin for receiving tenure as a Professor in Mechanical Engineering and Applied Physics at Caltech. March 7, 2017

Junlong publishes his work on daytime radiative cooling in ACS Photonics. February 3, 2017

News Archive

Spotlightmore

imagePaper published in ACS Nano

This work theoretically demonstrates a near-field radiative thermal switch based on thermally excited surface plasmons in graphene resonators. The high tunability of graphene enables substantial modulation of near-field radiative heat transfer, which, when combined with the use of resonant structures, overcomes the intrinsically broadband nature of thermal radiation. Furthermore, we derive shape-agnostic analytical approximations for the resonant heat transfer that provide general scaling laws and allow for direct comparison between different resonator geometries dominated by a single mode. The presented scheme is relevant for active thermal management and energy harvesting as well as probing excited-state dynamics at the nanoscale. Mar 12, 2018

imagePaper published in Physical Review B

In this work, we examine how thermal resistance depends on the heater geometry using analytical solutions of the Boltzmann equation. We show that the spatial frequencies of the heater pattern play the key role in setting the thermal resistance rather than any single geometric parameter, and that for many geometries the thermal resistance in the quasiballistic regime is no different than the Fourier prediction. Jan 10, 2018

imagePaper published in Physical Review B

We present a lattice and molecular dynamics analysis of vibrations in a-Si that supports a qualitatively different picture in which propagating elastic waves dominate the thermal conduction and are scattered by elastic fluctuations rather than anharmonicity. Our work suggests that most heat is carried by propagating elastic waves in a-Si and demonstrates a route to achieve extreme thermal properties in amorphous materials by manipulating elastic fluctuations. Jan 10, 2018

image Paper published in Physical Review Letters

We report a study of the vibrational properties and lattice thermal conductivity of a polyethylene molecular crystal using an ab initio approach that rigorously incorporates nuclear quantum motion and finite temperature effects. We obtain a thermal conductivity along the chain direction of around 160 W/m/K at room temperature, providing a firm upper bound for the thermal conductivity of this molecular crystal. October 31, 2017