Reposted from the University of Nevada, Las Vegas.
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 University of Nevada, Las Vegas is answering this problem with a groundbreaking technology that pulls large amounts of water from the air in low humidity. The research, whose co-authors include University of Utah engineers, was published Oct. 22 in the journal Proceedings of the National Academy of Sciences (PNAS).
UNLV mechanical engineering Prof. Jeremy Cho. Banner photo shows a prototype of an atmospheric water harvesting device developed in Cho’s lab. Credit: Jeff Scheid, UNLV.
UNLV 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.
Mechanical engineers Nathan Ortiz, left, and professor Sameer Rao of University of Utah describe a portable device they developed that draws fresh water from the atmosphere. They are co-authors on new research supporting high-yield technologies. Credit: Dan Hixson, University of Utah
“This work represents a significant shift in atmospheric water harvesting, opening doors to continuous operation and new applications of water production,” said co-author Sameer Rao, a U mechanical engineering professor. “These innovations are especially critical for the desert Southwest and its sustainability efforts.”
Rao’s Utah lab recently published a study that demonstrated the viability of a small portable device it designed, with funding from the U.S. Army, to draw drinking water from the atmosphere in arid places.
A key ingredient in the UNLV-led project 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,” Cho said. “There are so many cool things happening in nature – you just have to look around, learn, and be inspired.”
Along with Arizona State University, the U and UNLV are key partners in Southwest Sustainability Innovation Engine (SWSIE), a $15 million initiative funded by the National Science Foundation to confront the climate challenges facing the desert Southwest and spur economic development in the region. A UNLV startup company called WAVR Technologies, Inc. aims to bring this new technology to market as part of the SWSIE program.
Additionally, the new research demonstrates that atmospheric water harvesting can be solar-powered. Thanks to the frequent sunlight experienced in places such as the Las Vegas Valley – which averages 300 sunny days a year sunlight can provide enough energy to reduce the theoretical and eventual cost of generating water.
“Our water resources are depleting and our planet’s climate is changing,” Cho said. “To reach sustainability, we have to change our habits. This whole idea seemed like science fiction, but this is possible, and we’re actually doing it.”
“High-yield atmospheric water capture via bioinspired material segregation” was published on Oct. 22, 2024, in the journal Proceedings of the National Academy of Sciences. Authors come from UNLV, the University of Michigan and the University of Utah. In addition to Cho, co-authors include Yiwei Gao, Areianna Eason, Santiago Ricoy, Addison Cobb, Ryan Phung, Air Kashani, Mario R. Mata, Aaron Sahm, Nathan Ortiz and Sameer Rao.