Experiments on transformation thermodynamics: Molding the flow of heat

TL;DR

This paper demonstrates the design, fabrication, and testing of a micro-structured thermal cloak that manipulates heat flow around an object, based on transformation thermodynamics principles.

Contribution

It introduces a practical implementation of transformation thermodynamics to create a thermal cloak that controls heat flow in a metal plate.

Findings

Successful fabrication of a thermal cloak with micro-structured materials

The cloak effectively redirects heat flow around the object

Transient heat protection achieved without altering downstream heat flow

Abstract

It has recently been shown theoretically that the time-dependent heat conduction equation is form-invariant under curvilinear coordinate transformations. Thus, in analogy to transformation optics, fictitious transformed space can be mapped onto (meta-)materials with spatially inhomogeneous and anisotropic heat-conductivity tensors in the laboratory space. On this basis, we design, fabricate, and characterize a micro-structured thermal cloak that molds the flow of heat around an object in a metal plate. This allows for transient protection of the object from heating, while maintaining the same downstream heat flow as without object and cloak.