Advances in Atmospheric Water Harvesting Hydrogels: A Review of Material Design, System Integration, and Practical Applications

The global freshwater shortage poses severe threats to human life, thus driving extensive research on sorbent‐based atmospheric water harvesting (SAWH). Hydrogel materials, owing to their unique 3D network structures, possess exceptional capabilities in water absorption, storage, and desorption, which make them pivotal for SAWH application. This review systematically analyzes recent advances in hydrogel‐based atmospheric water harvesting (AWH), with a focus on material design and system optimization. Specifically, the working principles of hydrogel‐based sorbents are elucidated by examining two fundamental processes: water adsorption and desorption. Moreover, we highlight how the applications of SAWH hydrogels are expanding beyond water production into domains such as agricultural irrigation, energy harvesting, and thermal management, which reveals their considerable versatility. Finally, we present future research directions for hydrogel materials aimed at addressing water scarcity and promoting sustainable resource use.