Scientists built a sponge pulling water from dry air; yields 1.72L per kg/day

Image: AI-generated representation of a wood-based sponge that pulls water from air as dry as 15% humidity Water vapour is present almost everywhere, even in places where rivers, lakes and groundwater are scarce. The challenge has always been turning that invisible moisture into usable freshwater efficiently enough to make atmospheric water harvesting practical. Now, researchers have developed a wood-based material that can capture water from remarkably dry air. The sponge continued absorbing moisture at relative humidity as low as 15%, while a larger system built from the material produced as much as 1.72 litres of freshwater per kilogram of sorbent per day during outdoor testing.The technology combines a porous sponge made from balsa wood with lithium chloride, a moisture-attracting salt, and a separate layer designed to capture and store solar heat. This allows the material to absorb water vapour from the atmosphere and then release the collected water even when sunlight becomes weak or disappears.The work, published in Nature Communications under the title ‘Hygroscopic wood sponge with dual phase change function for enhanced all-weather atmospheric water harvesting,’ was led by...