Experimental investigation of thermal architected metamaterials for regulating transient heat transfer

Abstract

Metamaterials have innovative functionalities as a result of artificial design. By arbitrarily designing thermal conductivity, thermal metamaterials have achieved thermal invisible cloaks, camouflages, and deceptions in steady-state. However, density and specific heat capacity have sometimes been overlooked, despite the fact that they are critical for managing transient heat flow and that density are an indicator of creating lightweight materials. The traditional materials are incapable of synchronously controlling thermal conductivity, density, and specific heat capacity. In this research, we experimentally investigate a novel thermal architected metamaterial that can modulate (accelerate or decelerate) transient heat transfer velocity without disrupting the steady-state. The novel type of thermal architected metamaterial achieves efficiency using a topology based on neutral inclusion theory. The transient heat transfer velocity is regulated by altering the effective density and specific heat capacity on the one hand, while the steady-state heat transfer is maintained by keeping the effective thermal conductivity on the other. The density of the architected metamaterial could be adjusted by selecting an appropriate specific heat capacity. The method we provide can be utilized to create lightweight energy-efficient materials (by accelerating transient heat transfer) as well as lightweight engineered thermal protection materials (by decelerating transient heat transfer). Moreover, the proposed thermal architected metamaterial could control heat flow velocity continuously, and this characteristic covers the gaps left by natural materials.