The idea of turning the air around us into drinking water is a marvel on its own. And grabbing a sustainable amount of it from low-humidity environments has long been closer to science fiction than reality.
As a megadrought stresses the water supply throughout the Southwest, revolutionary research out of 51ԹϺ is answering this problem with a groundbreaking technology that pulls large amounts of water from the air in low humidity. The research was published Oct. 22 in the journal Proceedings of the National Academy of Sciences (PNAS).
51ԹϺ mechanical engineering professor H. Jeremy Cho leads a team of researchers with a radically different approach to atmospheric water harvesting, or transforming water vapor in the air around us into a usable form. Existing atmospheric water harvesting approaches have low yields and diminishing returns below 30% humidity.
“This paper really establishes that you can capture water at a very fast rate,” said Cho. “We can start to forecast how big of a system we would need to produce a set amount of water. If I have one square meter, which is around three feet by three feet, we can generate about a gallon of water per day in Las Vegas, and up to three times more in humid environments.”
This technology and approach has been tested outdoors in Las Vegas, and is effective down to 10% humidity. It directly captures water in a liquid salt solution that is suitable for subsequent processing into drinking water or energy production, enabling new capabilities for arid regions.
A key ingredient in the process is a hydrogel membrane “skin.” The inspiration for this material comes from nature – specifically tree frogs and air plants, which use a similar technique to transport water from ambient air into a liquid for internal storage.
“We took that biological idea and tried to do it in our own way,” he said. “There are so many cool things h