Their device turns seawater into drinking water for less than bottling

Materials scientists in China have built a solar-powered device that turns seawater into drinking water for less than the cost of bottling it. Researchers from the Institute of Process Engineering at the Chinese Academy of Sciences and Shenzhen University designed a weave of nanoparticle spheres threaded with polymer, taking their cue from the humble shirt button. The spheres reflect sunlight into one another, absorbing 90.2% of incoming light and cutting the energy needed to evaporate water by nearly half. Earlier attempts at solar evaporation kept failing because the absorbing powders clumped like flour and the polymers cracked. This version held up, even in tests that mimicked a stormy coastline. Over a year, it produced 5.3 gallons of drinkable water daily, enough to irrigate a small plot of bok choi and corn. The team says scaling it up could undercut bottled water within two years. They are still working on the condensation.