Experimental evidence for the bending of heat flux in a thermal metamaterial

Multilayered oriented composites constituted from two materials of different thermal conductivities are shown to have the ability to direct thermal energy. The composites behave as effective media with anisotropic thermal conductivity. The guiding of the heat flux is shown experimentally with bending angle ranging from ∼25° to the maximum possible value of ∼45° (for the considered prototypical composites) with respect to a horizontal temperature gradient—in excellent accord with theoretical estimates and computational simulations. Such thermal metamaterials lay the basis for efficient manipulation of heat and for thermal elements, such as thermal concentrators and cloaks.

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