Intelligent thermal cloak-concentrators

TL;DR

This paper introduces a novel class of intelligent thermal metamaterials called thermal cloak-concentrators that can automatically switch between cloaking and concentrating heat flow based on temperature changes, using nonlinear thermal conduction.

Contribution

It presents the analytical and numerical design of switchable thermal metamaterials that change function with temperature, inspired by intelligent electronic components, and confirms their behavior through effective medium theory.

Findings

Demonstrated switchable cloaking and concentrating behavior

Validated designs with homogeneous isotropic materials

Enabled potential for multifunctional heat flow control

Abstract

How to macroscopically control the flow of heat at will is up to now a challenge, which, however, is very important for human life since heat flow is a ubiquitous phenomenon in nature. Inspired by intelligent electronic components or intelligent materials, here we demonstrate, analytically and numerically, a unique class of intelligent bifunctional thermal metamaterials called thermal cloak-concentrators, which can automatically change from a cloak (concentrator) to a concentrator (cloak) when the applied temperature field decreases (increases). For future experimental realization, the behavior is also confirmed by assembling homogeneous isotropic materials according to the effective medium theory. The underlying mechanism originates from the effect of nonlinearity in thermal conduction. This work not only makes it possible to achieve a switchable Seebeck effect, but also offers guidance both for macroscopic manipulation of heat flow at will and for the design of similar intelligent multifunctional metamaterials in optics, electromagnetics, acoustics, or elastodynamics.