Researchers at the University of Texas have developed a new system that can extract drinking water from the air using natural materials like food waste, tree branches, and seashells.
This innovative system transforms various natural materials into "molecularly functionalized biomass hydrogels" that have liquid-absorbing properties, allowing them to collect liters of drinking water from the atmosphere, even in dry conditions, by combining these materials with mild heat.
Professor Guihua Yu from the Department of Materials Science and Mechanical Engineering at the University of Texas stated, "With this invention, we've created a universal molecular engineering strategy that makes various natural materials highly efficient water absorbers. This is a significant step toward sustainable water collection systems."
The research team conducted field tests, producing 14.19 liters of clean water per day with one kilogram of absorbent material. Existing systems typically produce between 1 to 5 liters, while the new method offers significantly higher efficiency.
The researchers emphasized that their system differs from traditional approaches that select specific materials for specialized purposes. The new molecular strategy makes it possible to efficiently convert almost any type of biomass into a water-collecting material.
Current synthetic water absorbers generally use petrochemical substances and require high energy, whereas the biomass-based hydrogel developed by the University of Texas team is biodegradable, widely producible, and requires minimal energy for water release.
The secret to this success lies in a two-step molecular engineering process that imparts hygroscopic and heat-sensitive properties to biomass-based polysaccharides—such as cellulose, starch, or chitosan.
Lead author and PhD student Weixin Guan said, "At the end of the day, access to clean water must be simple, sustainable, and scalable. This material allows us to extract water from the air using the most abundant resources in nature."
Professor Yu and his team have been working on solutions for communities with limited access to water. Yu had previously worked on hydrogels capable of producing water even in the driest regions and developed a water filtration system that can be applied via injection.
The system holds significant potential for water systems. The researchers are focusing on scaling up and designing devices for real-world applications, including portable water collection devices, self-sustaining irrigation systems, and emergency drinking water solutions.
Yaxuan Zhao, a researcher working in Yu's lab, said, "The biggest challenge in sustainable water collection is developing an efficient and viable solution that can work outside the lab. This hydrogel, which can be made from widely available biomass and operates with low energy, holds great potential for rural areas, emergency interventions, and decentralized water systems."
