Molecular Dynamics Study on Nano/Microscale Thermal Energy Transport

Abstract

Thermal energy transport at nano- and microscales is governed by interfacial interactions, spatial confinement, and characteristic length scales, for which conventional Fourier descriptions may become inadequate. This talk presents nonequilibrium molecular dynamics studies of heat transfer across vacuum nanogaps and solid–liquid interfaces. At subnanometer separations, quasi-Casimir coupling enables phonon transmission between two solid surfaces, while interfacial thermal resonance provides efficient energy transfer channels. For SiC nanogaps, vibrational spectra and local heat flux analyses show that identical atomic terminations enhance heat transfer via improved interfacial phonon matching. Moreover, negative electric fields modify vibrational displacements of interfacial atoms and strengthen optical phonon dominated tunneling channels. For solid–liquid systems, Kapitza length was examined under constant heat flux and overall temperature difference at nano- and microscales. Three primary regimes of solid–liquid interfacial heat transfer are identified: phononic, transition, and conductive regimes. These findings provide a unified multiscale framework for understanding interfacial thermal transport and support the design of nano- or microscale thermal management systems.

Wentao Chen

Associate Professor

My research interests include extreme near-field heat transfer, thermal transport at the solid-solid and solid-liquid interface, and molecular dynamics simulation.