A team of engineers from Australia and China has developed a sponge-like device that can extract drinkable water from the air, even in low humidity conditions where traditional methods like fog harvesting and radiative cooling typically fail. Powered entirely by the sun, the innovation offers a promising solution for water scarcity in remote or disaster-affected areas.
Designed by researchers from RMIT University in Melbourne and five Chinese institutions, the device functions effectively across a wide range of environmental conditions, including humidity levels between 30% and 90% and temperatures from 5 to 55 degrees Celsius.
At the core of the invention is a modified form of balsa wood, chosen for its naturally porous, spongy structure. The wood has been enhanced with lithium chloride, iron oxide nanoparticles, and a carbon nanotube layer, enabling it to absorb moisture from the atmosphere and release it on demand using solar heat.
The composite material is housed in a small cup-like container with a dome lid, anti-pollution tray, a passive cooling mechanism, and a solar-powered activation system. The design allows the lid to remain open to collect moisture and then close under sunlight to trigger water release into the cup.
In laboratory testing, the device demonstrated the ability to absorb up to 2 milliliters of water per gram of material at 90% humidity, releasing nearly all of it within 10 hours of sunlight exposure. Using nine small sponge cubes, researchers collected 15 milliliters of water in a single cycle.
Outdoor tests confirmed the system’s reliability, with a collection rate of 2.5 milliliters per gram overnight and a 94% water recovery rate during the day. Even in low humidity conditions (30%), the device absorbed approximately 0.6 milliliters per gram of material.
Beyond performance, the material showed durability and resilience. It maintained its water-absorbing capabilities after being stored at -20°C for 20 days and performed consistently over 10 absorption-release cycles, with less than a 12% drop in efficiency.
The team employed artificial intelligence to optimize the device’s design and performance predictions under different conditions, further improving its practical application potential.
This solar-powered water-from-air device holds promise for use in off-grid locations, disaster zones, and arid regions. Its low cost, scalability, and reliance on renewable energy make it a compelling option for emergency water access. The current prototype is 15 cubic millimeters, but researchers say it can be scaled up or configured in modular arrays to increase output.
If further developed, this bioinspired innovation could become a vital tool in addressing global water scarcity challenges.
By Impact Lab
