Thermal diode-like metafabric with tunable asymmetric structure for continuous personal cooling

Abstract

Personal cooling textiles that can ensure human health and alleviate energy crises have been fabricated from various mechanisms including radiation, evaporation, and convection. However, there exists a significant challenge in achieving continuous cooling solely through thermal conduction especially in a changing environment. We report a novel strategy to create a thermal diode-like metafabric (TDM) with a tunable asymmetric structure that enables unidirectional thermal conductivity. The premise of the design is that the TDM dissipates body heat via the dense layer and insulates against environmental heat with the fluffy layer, making the heat dissipation function like a “thermal diode”. The resulting TDM can achieve a continuous cooling of 3.5 °C compared to cotton fabric, solely through thermal conduction. Additionally, it also integrates properties of ultrahigh air and moisture permeability, shape memory, and mechanical durability. The successful synthesis of such fascinating material may offer new perspectives on the design and advancement of thermal management materials in various fields.