Solar evaporator with self-regulating channel network inspired by the respiration function of leaves

As a potentially effective solution for achieving future freshwater sufficiency and a low-carbon environment, the development of solar-driven interfacial evaporation (SDIE) technology toward practical applications has become increasingly imperative. However, fluctuating natural illumination introduces significant instability to dynamic evaporation, imposing higher demands on water transport. Inspired by efficient photosynthesis in leaves achieved through respiratory behavior under environmental variations, this study developed a self-regulating network evaporator (SNE) featuring numerous internally distributed self-regulating units composed of thermosensitive SA-g-PNIPAAm hydrogel microspheres. Capillary channels interconnect the carbon link-loaded surface with each unit, mimicking the dynamic collaboration among leaf stomata, veins, and mesophyll cells. By designing the distribution layout of the units, the coupling mechanism between global thermally-driven water supply and the water/thermal balance within the evaporation surface under varying irradiance was explored, revealing the existence of an optimal dynamic surface relative water content (RWC) range for evaporation enhancement. The SNE with optimized sodium alginate (SA) content demonstrated exceptional dynamic thermal-water management capability (RWC fluctuation <4%), achieving an average evaporation efficiency of 90% across irradiance intensities of 0.5–2 kW/m 2 . Furthermore, through sequential water supply and structural design of the units, the SNE maintains average evaporation rate and average evaporation efficiency of 1.97 kg·m −2 ·h −1 and 97%, respectively, during 9-h standard solar irradiation (1 kW/m 2 ) while reducing hydrogel consumption by 36%. Under all-day outdoor illumination with irradiance fluctuations up to 60%, the SNE achieved a seawater desalination efficiency of 96% with only 2% RWC variation, demonstrating its potential for practical applications under diurnal environmental fluctuations.