Today, 2.2 billion people lack access to safe drinking water, including over 46 million in the US, according to MIT News. MIT engineers have developed a novel, passive atmospheric water harvester that extracts clean drinking water from air vapor, even in dry desert conditions like Death Valley. The device uses a black hydrogel panel with bubble-wrap-like domes that absorb water vapor overnight and release it during the day, where it condenses on a cooled glass surface and is collected as drinkable water. Unlike other systems, this design requires no external power and minimizes salt contamination by stabilizing salt within the hydrogel. After testing for over a week, it produced up to 160 milliliters of water daily in very low humidity, showing promise to provide sustainable water in resource-limited and arid regions. They write:
MIT team has developed and tested a new atmospheric water harvester and shown that it efficiently captures water vapor and produces safe drinking water across a range of relative humidities, including dry desert air.
The new device is a black, window-sized vertical panel, made from a water-absorbent hydrogel material, enclosed in a glass chamber coated with a cooling layer. The hydrogel resembles black bubble wrap, with small dome-shaped structures that swell when the hydrogel soaks up water vapor. When the captured vapor evaporates, the domes shrink back down in an origami-like transformation. The evaporated vapor then condenses on the the glass, where it can flow down and out through a tube, as clean and drinkable water. […]
โWe imagine that you could one day deploy an array of these panels, and the footprint is very small because they are all vertical,โ says Zhao, who has plans to further test the panels in many resource-limited regions. โThen you could have many panels together, collecting water all the time, at household scale.โ […]
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