All-day fresh water harvesting by microstructured hydrogel membranes

Abstract Solar steam water purification and fog collection are two independent processes that could enable abundant fresh generation. We developed a hydrogel membrane contains hierarchical three-dimensional microstructures with high surface area combines both functions serves as an all-day harvester. At night, the efficiently captures droplets directionally transports them to storage vessel. During daytime, it acts interfacial solar generator achieves evaporation rate of 3.64 kg m ?2 h ?1 under 1 sun enabled by improved thermal/vapor flow management. With homemade rooftop harvesting system, this can produce daily yield ~34 L in outdoor test, which demonstrates its potential for global scarcity relief.