Deserts like Death Valley can be an extraordinary source of drinking water
Mimi Ditchie Photography/Getty Images
The compact panels managed to extract a glass of clean water from the arid air of Death Valley, California.
Although the atmosphere over extremely dry regions can retain a significant amount of water, extracting it into usable supplies has proven challenging. Previous methods, including simple mesh fabrics and mist-capturing nets crafted from synthetic spider silk, have struggled to function effectively in real-world conditions.
Now, Xuanhe Zhao from the Massachusetts Institute of Technology and his team have created a unique water collector, about 0.5 meters tall and 0.1 meters wide. It features a glass panel embedded with absorbent hydrogels—gel-like substances formed from long polymer chains and lithium salts, enabling it to gather water molecules.
The hydrogel is designed to fold into an origami-like configuration, enhancing surface area to capture moisture during the night. The absorbed water evaporates when sunlight hits the glass panel the next day. The interior of the device is coated with a specialized cooling material, which collects the evaporated water as it condenses and drips into a storage compartment below.
Zhao and his team conducted a week-long test of the apparatus in Death Valley, where humidity can plummet to as low as 5%. In comparison, the annual average in London hovers around 70%. They discovered the device can harvest up to 160 milliliters of water each day, enough to fill a small glass.
It’s estimated that eight of these panels could meet the daily drinking water requirements of an average adult, making them especially beneficial in arid regions. “Given the compact design of the device, we believe larger arrays could provide drinking water to households for consumption,” says Zhao.
Zhao and his colleagues assert that while the device shows promise in real-world conditions, Daryl Williams from Imperial College London cautions that extended testing—beyond a week—could present challenges. “Outdoor environments are generally hostile. We want to observe how the device performs under such stress after three, six, or even nine months.”
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Source: www.newscientist.com