Heat conduction in multifunctional nanotrusses studied using Boltzmann transport equation

TL;DR

This study investigates heat conduction in nanotrusses with complex geometry using Boltzmann transport equation, revealing their potential to achieve low thermal conductivity alongside high stiffness and low density.

Contribution

It introduces a novel simulation approach for nanotruss heat conduction and identifies key parameters controlling thermal properties.

Findings

Thermal conductivity depends mainly on solid fraction and wall thickness.

Nanotrusses can achieve unique mechanical and thermal property combinations.

Simulations predict low thermal conductivity in nanotrusses with specific geometries.

Abstract

Materials that possess low density, low thermal conductivity, and high stiffness are desirable for engineering applications, but most materials cannot realize these properties simultaneously due to the coupling between them. Nanotrusses, which consist of hollow nanoscale beams architected into a periodic truss structure, can potentially break these couplings due to their lattice architecture and nanoscale features. In this work, we study heat conduction in the exact nanotruss geometry by solving the frequency-dependent Boltzmann transport equation using a variance-reduced Monte Carlo algorithm. We show that their thermal conductivity can be described with only two parameters, solid fraction and wall thickness. Our simulations predict that nanotrusses can realize unique combinations of mechanical and thermal properties that are challenging to achieve in typical materials.