Dynamically Tunable Subambient Daytime Radiative Cooling Metafabric with Janus Wettability
Chonghui Fan, Yuxin Zhang, Zhiwen Long, Alfred Mensah, Qingqing Wang, Pengfei Lv, Qufu Weı
Abstract
Abstract Incorporating zero‐energy‐input cooling technology into personal thermal management (PTM) systems is a promising solution for preventing heat‐related illnesses while reducing energy consumption. Although concepts for passive radiative cooling materials are proposed, achieving subambient cooling performance while providing good wearing comfort remains a challenge. Here, a moisture‐wicking nonwoven metafabric is reported that assembles radiative cooling and evaporative heat dissipation to achieve high‐performance thermal and moisture comfort management. This metafabric demonstrates excellent spectral‐selectivity (sunlight reflection of ≈92%, atmospheric window thermal emissivity of ≈97%) and Janus wettability through large‐scale electrospinning and hierarchical design, and also inherits superior elasticity, air/moisture permeability of nonwoven fabric. Subambient temperature drops of ≈6.5 °C (≈750 W m −2 solar intensity) for stand‐alone metafabric are observed. Thanks to the moisture‐wicking effect (water evaporation rate of 0.31 g h −1 and water transport index of 1220%) of metafabric that enables fast evaporation of sweat, a maximum generation of 1 mL h −1 of sweat can cool the skin, thus reducing the excessive sweating risk after intense exercise. Additionally, the cooling performance of metafabric can be regulated by applying various strains (0–100%). The cost‐efficiency and good wearability of metafabric provide an innovative way to sustainable energy, smart textiles, and thermal wet comfort applications.