Portable sun-powered water harvester could combat water scarcity
University of California Berkeley researchers have designed an extreme-weather proven, hand-held device that can extract and convert water molecules from the air into drinkable water using only ambient sunlight as its energy source, a study published in Nature Water shows.
This atmospheric water harvester used an ultra-porous material known as a metal-organic framework (MOF) to extract water repeatedly in the hottest and driest place in North America, Death Valley National Park. These tests showed the device could provide clean water anywhere, addressing an urgent problem, as climate change exacerbates drought conditions.
“Almost one-third of the world’s population lives in water-stressed regions. The UN projects in the year 2050 that almost 5 billion people on our planet will experience some kind of water stress for a significant part of the year,” said Omar Yaghi, the Berkeley chemistry professor who invented MOFs and is leading this study. “This is quite relevant to harnessing a new source for water.”
Other kinds of materials such as hydrogels, zeolites or salts cannot operate in low-humidity conditions, in an energy-efficient manner and with a high capacity all at once. MOF-powered harvesters can, making them an exceptionally powerful tool to address water scarcity issues related to anything from drinking water to agriculture. This technology can also be used to secure pure water in regions where water is abundant, but not clean.
The study illustrates one way specially-designed MOFs could help society combat and adapt to climate change. Experts at the College of Computing, Data Science, and Society’s Bakar Institute of Digital Materials for the Planet (BIDMaP) are using data science and machine learning to accelerate and scale up the designing of these molecules, materials and devices.
“What we’re doing at BIDMaP is creating what I call the ‘digital innovation cycle’ to connect the molecule, the material and how the material is configured and fits into the device including the actual device design, its efficiency and performance,” said Yaghi, co-director and chief scientist of BIDMaP. “All of these are connected, and each part has to be optimized to get the highest performance.”
The authors of the study, “MOF water harvester produces water from Death Valley desert air in ambient sunlight,” are Woochul Song, Zhiling Zheng, Ali Alawadhi and Yaghi. They are affiliated with Berkeley’s Department of Chemistry, Kavli Energy NanoScience Institute and BIDMaP.