Aug. 22, 2019
Dr. Simon Dai, assistant professor of mechanical engineering, uses a goniometer to measure the water contact angle on a new surface. He and his team, which includes doctoral student Zongqi Guo (right), have received funding to create a more durable lubricant for sustainable water harvesting.
Dr. Simon Dai, assistant professor of mechanical engineering in the Erik Jonsson School of Engineering and Computer Science at The University of Texas at Dallas, has been awarded a three-year grant to advance technology he has developed to harvest clean water from the air without using external energy.
The funding was provided through the Army Research Office’s Young Investigator Program. The project will further the development of an earlier surface engineered by Dai and fellow researchers that can attract and capture water droplets from fog and moisture in the air.
“Our ultimate goal is to harvest water from air, particularly humid air, directly for agriculture, horticulture or drinking purposes without using any external energy. It’s a passive technology that can be used anywhere on the planet as long as there is humid air.”
The surface they designed, called a “slippery rough surface,” or SRS, involves the use of a liquid lubricant that attracts water and quickly directs it through microgrooves into reservoirs. The researchers have filed a patent for the technology.
“A liquid lubricant can be depleted by water,” Dai said. “If that happens, the surface will lose water-harvesting capability. More importantly, the liquid lubricant might also contaminate the harvested water.”
The new funding will help Dai’s research group create a more durable lubricant for sustainable water harvesting. Because the liquid lubricant wraps around water droplets, some of it can be lost to runoff or evaporation.
“Our ultimate goal is to harvest water from air, particularly humid air, directly for agriculture, horticulture or drinking purposes without using any external energy. It’s a passive technology that can be used anywhere on the planet as long as there is humid air,” Dai said. “We hope this can contribute to overcome the problem of water scarcity in arid regions.”
Dr. Mario Rotea, department head of mechanical engineering and the Erik Jonsson Chair in the Jonsson School, said water scarcity was identified as one of humanity’s top 10 problems over the next 50 years by Dr. Richard E. Smalley, winner of the 1996 Nobel Prize in Chemistry.
“Dr. Dai’s research paves the way toward a practical solution to this problem,” Rotea said. “His approach is focused on durability aspects of nano-engineered surfaces, which is a recognized barrier for the application of nanotechnology to this and other important problems.”
The new focus involves using a liquid polymer, which would act as a coating that cannot be washed off but behaves like a lubricant. The new technology also would have a self-cleaning mechanism that removes contaminants and provides safe drinking water.
The durable water-harvesting surface, inspired by processes in nature, has a wide variety of applications in a broad range of industries. It can be optimized and adjusted to fit specific applications, Dai said.
The Young Investigator Program award is one of the most prestigious honors bestowed by the Army to outstanding researchers who are beginning their independent careers. The program is designed to identify and support scientists and engineers who show promise for doing creative work in order to encourage their teaching and research careers. The Army Research Office is an element of U.S. Army Combat Capabilities Development Command’s Army Research Laboratory.
“Through this research, Dr. Dai is pushing the envelope by developing new fundamental scientific understanding of how liquids interact with functionalized and patterned surfaces,” said Dr. Evan Runnerstrom, manager of the materials design program at Army Research Office. “If his approach is successful, this knowledge can be leveraged to create artificial surfaces with control over liquid-surface interactions at the molecular level. This could lead to the design of robust, self-cleaning surfaces that resist contamination across various Department of Defense missions, in addition to the ability to harvest and purify water in the field.”