Princeton University postdoctoral researcher Xiaohui Xu and engineering professor Rodney D. Priestley were developing a jellylike material for use in artificial skin when they realized it could have another use: purifying drinking water. The two designed a new hydrogel that can be used as a low-cost, sunlight-powered filter for the hundreds of thousands of people around the world who lack access to clean drinking water.
“You can think of it as a sustainable, high-tech sponge,” says Priestley. Beyond off-grid applications, the two are exploring other ways the gel might be used, including to purify rainwater on building roofs or to help filter lead out of water at schools. They’re now launching a startup to begin making the tech a reality.
HOW IT WORKS
1. When placed on a floating, porous plate in a polluted river or another body of water, the gel naturally absorbs only water, leaving contaminants like heavy metals and bacteria behind.
2. The gel is removed from the body of water and placed in the sun, which triggers it to heat up.
3. Once it reaches 91 degrees Fahrenheit, the gel becomes hydrophobic and releases the clean water, which is safe to drink, into another container.
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