KAUST team create hydrogel combination to tap more water from air

The team at KAUST (King Abdullah University of Science & Technology) in Saudi Arabia said the device can capture its own weight in water from fresh air and then release it when warmed by sunlight.

The Earth’s air is estimated to contain almost 13 trillion tons of water but previous attempts to exploit the renewable resource have either been too inefficient, expensive or complex for practical use. Now, a prototype device developed by Peng Wang from the Water Desalination and Reuse Center and his team could change that.

Central to the device is calcium chloride, a form of salt that is cheap, stable, and non-toxic. This deliquescent salt has such a high affinity for water that it will absorb so much vapour from the surrounding air that eventually a pool of liquid forms, said Renyuan Li, a PhD student in Wang's team. "The deliquescent salt can dissolve itself by absorbing moisture from air.”