Engineering Minute

Engineering Minute – Solar-Powered Moisture Harvester

Researchers at The University of Texas at Austin have developed a breakthrough technology that relies on solar-power to absorb moisture from the air and produce clean, usable water from it. The technology uses hydrogels that are both highly absorbent and can release water when heated. This breakthrough technology was recently written about in the journal Advanced Materials.  


“We have developed a completely passive system where all you need to do is leave the hydrogel outside and it will collect water,” said Fei Zhao, a postdoctoral researcher at University of Texas at Austin, and co-author of the study. “The collected water will remain stored in the hydrogel until you expose it to sunlight. After about five minutes under natural sunlight, the water releases.”



From the University of Texas at Austin article: "This technology builds upon a 2018 breakthrough made by Yu and Zhao in which they developed a solar-powered water purification innovation using hydrogels that cleans water from any source using only solar energy. The team’s new innovation takes that work a step further by using the water that already exists in the atmosphere. For both hydrogel-based technologies, Yu and his research team developed a way to combine materials that possess both hygroscopic (water-absorbing) qualities and thermal-responsive hydrophilicity (the ability to release water upon simple heating).

'The new material is designed to both harvest moisture from the air and produce clean water under sunlight, avoiding intensive energy consumption,' said Yu, an associate professor of materials science and mechanical engineering.

Harvesting water from moisture is not exactly a new concept. Most refrigerators keep things cool through a vapor condensation process. However, the common fridge requires lots of energy to perform that action. The UT team’s technology requires only solar power, is compact and can still produce enough water to meet the daily needs of an average household. Prototype tests showed daily water production of up to 50 liters per kilogram of hydrogel."


Read more about the solar-powered moisture harvester at University of Texas at Austin.