Bioinspired Metafabric with Dual‐Gradient Janus Design for Personal Radiative and Evaporative Cooling

Abstract Personal radiative cooling fabrics are a promising zero‐energy solution for creating a cool and comfortable microclimate for outdoor crowds. Despite significant progress, achieving efficient radiative cooling under some extreme situations, such as thermal shock and intensive physical activity, remains a challenge. Herein, a bioinspired metafabric with a dual‐gradient Janus design is reported for personal radiative and evaporative cooling. The hierarchical fiber structure allows for an excellent solar reflectance of 99.4% and mid‐infrared emittance of 0.94, inducing a skin temperature drop of 17.8 °C under intense sunlight. Mesoporous silica nanoparticles fixed in the fibrous network can store evaporative cooling capacity by atmospheric moisture‐absorption in the mild and humid nighttime and release such cooling capacity by moisture‐desorption in the hot daytime, providing an additional skin temperature drop of 2.5 °C. Dual‐gradient Janus design endows the metafabric with an outstanding sweat‐wicking effect and high‐performance sweat evaporative cooling capacity. In the steady‐state evaporation tests, a maximum sweat consumption of only 0.5 ml h −1 can cool the skin to a comfortable temperature, preventing harmful excessive sweating. Additionally, the bioinspired metafabric also possesses favorable wearability and color expansibility. Given these first‐rate features, the bioinspired metafabric will pave the way for the development of advanced functional fabrics.