Universal thermometry of solid-liquid interfacial thermal conductance

TL;DR

A universal broadband thermometry method is introduced for quantifying solid-liquid interfacial thermal conductance across diverse interfaces, validated on multiple systems, and revealing the influence of surface and material properties on heat transfer.

Contribution

The paper presents a novel, broadly applicable thermometry technique capable of measuring interfacial thermal conductance for various solid-liquid interfaces, including nonpolar and polymer systems.

Findings

Measured ITC for Al-water as 50-55 MW/m^2K, consistent with prior data.

Found significantly lower ITC values for glass-water and Si-water interfaces.

Extended validation to viscous liquids and polymers, demonstrating broad applicability.

Abstract

Solid-liquid interfacial thermal conductance (ITC) critically influences heat transport in microfluidic, electronic, and energy systems, yet most optical thermometry techniques are limited to specific metal-liquid interfaces. In this work, we introduce a universal broadband square-pulsed thermometry method that enables simultaneous quantification of ITC across a wide range of arbitrary solid-liquid interfaces, while also providing accurate measurements of nanoscale liquid-film thickness. To validate the method, we applied it to Al-water interfaces, yielding ITC values in the range of 50-55 MW m^(-2) K^(-1), consistent with prior studies. The technique also reveals markedly lower ITCs for glass-water (9.9 MW m^(-2) K^(-1)) and Si-water (5.7 MW m^(-2) K^(-1)), and further measurements on Al-silicone oil (~10 MW m^(-2) K^(-1)) and PMMA-silicone oil (~0.4 MW m^(-2) K^(-1)) extend the validation to highly viscous nonpolar liquids and polymer-liquid interfaces. These results highlight the capability of the method to capture thermal transport differences across diverse solid-liquid combinations. Further comparisons with acoustic/diffuse mismatch models and molecular dynamics simulations, together with theoretical analysis, highlight the influence of vibrational mismatch, wettability, and surface condition on interfacial thermal transport. This broadly applicable technique enables rapid, quantitative characterization of solid-liquid interfacial thermal transport, with broad implications for interfacial heat transfer science and technology.