SYDNEY, May 8 (Xinhua) -- Australia's Royal Melbourne Institute of Technology (RMIT University) said on Thursday that engineers have developed a sponge-like device that captures water from air and releases it by using the sun's energy even in low humidity.
The university said in a press release that the device uses a modified wood-based material to absorb atmospheric moisture, even in dry conditions, and releases it using only sunlight.
The innovation employs treated balsa wood infused with lithium chloride, iron oxide nanoparticles, and a carbon nanotube layer, said the press release.
The result is a sustainable and biodegradable sponge that can harvest water efficiently across a wide range of humidity levels (30-90 percent) and temperatures (5-55 degrees Celsius), it said.
Unlike traditional fog or dew harvesting systems, this device performs effectively in varied environmental conditions at less cost. In laboratory tests, it absorbed up to 2 milliliters of water per gram of material at a humidity of 90 percent and released nearly all of it within 10 hours of sunlight exposure. Outdoor trials demonstrated a daily water collection efficiency of 94 percent.
Each compact unit, roughly the size of a cup and equipped with a dome lid, a cooling mechanism, and a solar activation system, can produce 15 milliliters of water using nine sponge cubes weighing just 0.8 grams each. Even at a low humidity of 30 percent, it harvested 0.6 milliliters of water per gram overnight, it said.
The device's ability to harvest potable water from the atmosphere using only sunlight makes it invaluable in disaster-stricken areas where traditional water sources are compromised.
The researchers were in discussion with prospective industry partners on pilot-scale production and field deployment. ■