Dynamic Multistage Sorption‐Based Atmospheric Water Harvesting Device With Redistributed Water Content

ABSTRACT Solar‐driven sorption‐based atmospheric water harvesting (SAWH) is an appealing way to address water scarcity in areas where liquid water sources are physically scarce. While multistage designs enhance vapor yield via latent heat recovery, conventional multistage SAWH suffers from decreased water content and reduced desorption kinetics in front stages, limiting energy recovery for subsequent stages. Here, we propose and demonstrate a dynamic multistage SAWH design for the first time, which not only recycles condensation heat but also dynamically redistributes water content, greatly enhancing the vapor yield for SAWH. The device consists of repeatable units as stages, with the first unit periodically switched to the last stage to maintain high water content in front stages, achieving high average vapor productivity. Outdoor tests show 172% and 36% increases in vapor yield compared to single‐stage and static multistage devices, respectively, reaching 3.95 kg m − 2 over five desorption hours under 0.74 kW m − 2 sunlight. Simulations indicate that batch‐assisted operation and hybrid solar–waste‐heat cycling can further enhance daily productivity. Our design is anticipated to be applicable to a range of sorbents and offers a universal strategy for promoting the yield of SAWH in remote and water‐stressed areas.