Solar-Powered Sponge Device Harvests Water from Air Even in Low Humidity

Researchers have developed a novel sponge-like device that can extract moisture from the air and release it into a container using solar energy. Unlike traditional fog-harvesting or radiative cooling techniques, this new technology functions reliably across a wide range of humidity levels (30%–90%) and temperatures (41°F-131°F), making it suitable for diverse and challenging environments.

At the heart of the device is a modified balsa wood structure, engineered to be porous and integrated with lithium chloride, iron oxide nanoparticles, and a layer of carbon nanotubes. This combination enhances both water adsorption and release, creating an efficient moisture capture-and-release system. Artificial intelligence was used to predict and optimize performance under varying environmental conditions, yielding excellent results in laboratory tests.

Experimental data shows that under 90% humidity, each gram of material can adsorb approximately 2 milliliters of water and release nearly all of it within 10 hours—outperforming many existing technologies. Outdoor trials revealed that the device could collect up to 2.5 milliliters per gram overnight, with a daytime release efficiency of 94%. Even at just 30% humidity, the material retained a water absorption capacity of 0.6 milliliters per gram.

Cost-effective and scalable, the device uses widely available, biodegradable balsa wood as its primary material. It also demonstrates strong durability—retaining functionality after 20 days of storage at -4°F and showing less than 12% efficiency loss after 10 reuse cycles. Its modular design allows flexible scaling, making it a promising solution for arid regions and emergency water supply in disaster scenarios.