Tested in California’s Death Valley<\/a> \u2013 one of the driest places on Earth \u2013 the harvester managed to extract over more than 50 milliliters of safe-to-drink water per day.<\/p>\n With 4.5 billion people<\/a> worldwide already without a consistent supply of safe drinking water, if such a device can be scaled and made easily accessible, it will save lives.<\/p>\n Related: Scientists Figured Out How to Extract Gold From Old Phones And Laptops<\/a><\/strong><\/p>\n “Our atmospheric water harvesting window sets a benchmark in daily water production and climate adaptability,” MIT mechanical engineer Chang Liu and colleagues write in their paper<\/a>.<\/p>\n “[It represents] an advance towards practical, scalable, safe and sustainable decentralized water solutions for the most water-stressed regions.”<\/p>\n Atmospheric water harvesters have so far been limited by a very low rate of water production (a few milliliters each day) and contamination with high levels of the materials used for the extraction, from salt to lithium.<\/p>\n In Death Valley, four surrounding mountain ranges push clouds up<\/a>, wringing them of most of their moisture before they reach the parched land beyond. This makes it a challenging test site for water collection.<\/p>\n But a hydrogel made from polyvinyl alcohol (PVA<\/a>), lithium chloride<\/a> (a salt that attracts water), glycerol<\/a>, and black ink was up to the task.<\/p>\n “Through our work with soft materials, one property we know very well is the way hydrogel is very good at absorbing water from air,” says<\/a> MIT mechanical engineer Xuanhe Zhao.<\/p>\n So the team molded this hydrogel into a bubble-wrap shape to increase its surface area for water collection. They ensured its microstructure lacked large enough pores to let the water-attracting salt slip out. Glycerol helped contain the salt inside the gel.<\/p>\n “We have built a meter-scale device that we hope to deploy in resource-limited regions, where even a solar cell is not very accessible,” explains<\/a> Zhao.<\/p>\n The panel of gel, sandwiched between panes of glass with a polymer outer film that assists with cooling, attracted up to 160 ml of water molecules overnight, when humidity was at its highest.<\/p>\n During the day, the water caught by the gel warms up, evaporates from the gel, and condenses on the cooler glass surface. Gravity, working on the vertical panel, along with a system of channels, then collects the water.<\/p>\n “This is just a proof-of-concept design, and there are a lot of things we can optimize,” says<\/a> Liu. “We’re working on a next generation of the material to further improve its intrinsic properties.”<\/p>\n Of course, even if technologically sound, such a device will only have its intended positive impacts if it can reach the people who need it the most<\/a>.<\/p>\n “It’s a test of feasibility in scaling up this water harvesting technology,” says<\/a> Zhao. “Now people can build it even larger, or make it into parallel panels, to supply drinking water to people and achieve real impact.”<\/p>\n![\"Strange](\"https:\/\/www.europesays.com\/us\/wp-content\/uploads\/2025\/06\/FurnaceCreekDryBedDeathValleyCalifornia-642x260.jpg\")
Furnace Creek in Death Valley. (Andy Kennelly\/500px\/Getty Images)<\/p>\n![\"Black,](\"https:\/\/www.europesays.com\/us\/wp-content\/uploads\/2025\/06\/MITatmosphericWaterHarvesterDeathValley.gif\")
The passive water harvester. (MIT<\/a>)<\/p>\n