Plant‐Inspired Symbiotic Atmospheric Water Sorption–Evaporation for High Efficiency Adaptive Passive Cooling

Abstract

ABSTRACT Atmospheric water sorption–evaporation passive cooling couples two antagonistic processes, moisture harvesting and evaporative heat dissipation, whose intrinsic trade‐off hinders integrated system‐level design and limits stable operation under high heat fluxes. Inspired by the heat‐moisture regulatory strategies of tropical broadleaves and xerophytic plants, we develop a symbiotic atmospheric water sorption–evaporation (SAWSES) device that integrates a co‐designed valve‐channel‐interface cascade to orchestrate sorption, evaporation, and heat–mass transport. A thermo‐responsive P(NIPAM ‐co‐ AM)–LiCl hydrogel valve releases liquid water at elevated temperature and reabsorbs atmospheric moisture upon cooling, enabling reversible, bidirectional water transport. Tree‐like micro/nanostructured wicking interfaces drive rapid droplet‐to‐film transition for highly efficient thin‐film evaporation, while vapor‐permeable channels accelerate moisture uptake and expand the effective evaporating area. Together, SAWSES boosts moisture‐harvesting capacity by 27% and sustains high evaporation rates, achieving a 68°C temperature reduction under 6.8 kW/m 2 heat flux. Benchmarking against representative sorption–evaporation cooling materials, including polyethylene–hydrogel composites, MOFs, and PAM–salt hydrogels, SAWSES demonstrates superior temperature reduction while maintaining robust adaptive cooling under high thermal loads. This work establishes a plant‐inspired, self‐regulating thermal management strategy with strong potential for reliable deployment in adaptive passive cooling.