Enhancing Near-Field Heat Transfer in Composite Media: Effects of the Percolation Transition

TL;DR

This paper demonstrates that near-field heat transfer between a semi-infinite medium and a nanoparticle can be significantly enhanced by using composite materials, especially near the percolation transition, offering a new way to optimize nanostructure heat transfer.

Contribution

It reveals that composite media can greatly enhance near-field heat transfer, with maximum effects at the percolation transition, and shows robustness across various conditions and theories.

Findings

Heat transfer can be up to thirty times larger with composite media.

Enhancement peaks at the percolation transition.

Results are robust against material losses and shape variations.

Abstract

We investigate the near-field heat transfer between a semi-infinite medium and a nanoparticle made of composite materials. We show that, in the effective medium approximation, the heat transfer can be greatly enhanced by considering composite media, being maximal at the percolation transition. Specifically, for titanium inclusions embedded in a polystyrene sphere, this enhancement can be up to thirty times larger than in the case of the corresponding homogeneous titanium sphere. We demonstrate that our findings are robust against material losses, to changes in the shape of inclusions and materials, and apply for different effective medium theories. These results suggest the use of composite media as a new, versatile material platform to enhance, optimize, and tailor near-field heat transfer in nanostructures.