Scientists have moved a step closer to being able to harvest drinking water directly out of the air.
The breakthrough could help supply troops in the field and address water shortages emerging in many parts of the world.
University of Utah mechanical engineering researchers this week unveiled a compact rapid cycling fuel-fired water extraction device.
The device draws water molecules out of non-humid air, then applies heat to release those molecules into liquid form.
Senior author of the study Sameer Rao said hygroscopic materials used in the device intrinsically had an affinity to water.
“They soak up water wherever you go,” he said. “We work with a specific type of hygroscopic material called a metal organic framework.”
This framework can be structured to create a molecule ideal for gas separation.
“They can make it specific to adsorb water vapor from the air and nothing else. They’re really selective,” Dr Rao said.
“The water molecules themselves get trapped on the surfaces of our material, and that’s a reversible process. And so instead of becoming ingrained into the material itself, it sits on the walls.”
Just a gram of this material holds as much surface area as two football fields. So just a little material can capture a lot of water.
Dr Rao said the research specifically looked at applications for defence and the possibility of producing water on demand in dry areas.
In the study, the prototype achieved its target of producing five litres of water per day per kilogram of adsorbent material. This would mean, over three days in the field, this devise would outperform packing water in canteens.
The full report is on the University of Utah website.
