A new solar-assisted atmospheric water harvester has been engineered at the University of Texas at Austin as a passive system for freshwater production developing areas. Without the need for an external energy supply, theResearchers examine a sample of the newly-developed hydrogel. Source: University of Texas at Austin compact unit can provide water sufficient to meet the daily needs of an average household.

Similar systems have been devised and tested, including a device incorporating aluminum-based metal-organic-framework (MOF) materials designed to extract water from arid desert air. This system yields 400 ml of water per day from a kilogram of MOF, while the new harvesting approach provides up to 50 L per day per kg of hydrogel.

The moisture‐absorbent gel composed of water-absorbing polypyrrole chloride and a water-releasing polymeric network of poly N‐isopropylacrylamide, demonstrated efficient water production over a range of relative humidity levels. The material absorbs water from the atmosphere, which is only released after about five minutes of exposure to natural sunlight.

The solar-hydrogel system could potentially replace core components in existing solar-powered water purification systems or other moisture-absorbing technologies.