Biomimetic Adaptive Hydrothermal Balance Fabric‐Based Dual‐Interface Solar Evaporator for Efficient and Stable Desalination

Abstract Matching energy input to water supply is key to efficient solar‐driven interfacial water evaporation, but conventional interfacial solar steam generators (ISSGs) fail to adapt to diurnal solar flux fluctuations, thus hindering the achievement of dynamic hydrothermal balance. Inspired by marine octopuses, a fabric‐based dual‐interface solar evaporator (PDMS‐CFs‐CFF‐SF) is developed by integrating 3D knitting and electrostatic flocking, enabling adaptation to light intensity changes. When light intensity exceeds the upper interface's water supply capacity and heat accumulates, hydrophobic spacer yarns facilitate the directional transfer of excess heat to the lower interface, thereby triggering dual‐interface evaporation. The lower interface, leveraging its large‐pore structure, regulates moisture content to match the transferred excess heat. Moreover, the octopus‐inspired structure increases the evaporation area, enriches vapor escape channels, enhances thermal insulation performance, and adapts to sunlight incident at different angles. Under 1 kW m −2 irradiation, the evaporator achieves an evaporation rate of 3.14 kg m −2 h −1 and an efficiency of 129.32%. This work provides a novel structural strategy for developing ISSGs with dynamic hydrothermal balance capabilities.