Metamaterials based on solid composites enable continuous and tunable thermal conductivity anisotropy for thermal management applications

Thermal metamaterials enable heat flow manipulation through artificial structures in both magnitude and direction and provide flexibility in achieving diverse applications. These metamaterials can provide thermal management of power electronic devices such as batteries in electric vehicles. However, the existing designs lack responsiveness during temperature changes and are difficult to package in limited space. By investigating macroscopic heat conduction using a theoretical framework, we design a tunable, thermal-metamaterial-based device by strategically arranging rotatable, sandwich-structured unit cells composed of conventional solid materials. The device can adapt and adjust the heat flux and heat flow direction continuously. The multifunctional thermal-metamaterial-based device presents a solution for addressing the challenges associated with regulating heat transfer in engineering applications.