Research conducted by mechanical engineers at the University of Utah is showing significant progress toward pulling water out of the air. The U.S. Department of Defense asked them to develop a device that provides soldiers with access to drinking water anywhere they may be.

The new research introduces a compact rapid cycling fuel-fired atmospheric water harvesting (AWH) device. The device uses hygroscopic (water-seeking) materials to attract water molecules out of the air, then adds heat to release the molecules into liquid form.

Think of the hygroscopic materials like Lego blocks that can be built into any sort of structure. The researchers for this study – Sameer Rao, assistant professor in the John and Marcia Price College of Engineering, and Nathan Ortiz, a mechanical engineering graduate student – arranged the materials into a structure that maximizes gas separation.

“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,” Ortiz said in an article on the university’s website. “What’s special about these absorbent materials is they have just an immense amount of internal surface area. There are so many sites for water molecules to get stuck.”

Rao and Ortiz explain how the device works in this video.

The prototype of the device, which uses one kilogram of hygroscopic material, produced five liters of water per day.

As Rao described it, the device “produces water on demand.”

Photo credit: Dan Hixson, University of Utah, College of Engineering