Tiny structures inspired by the shape of cactus thorns allow the new material to collect drinking water day and night. To create it, the researchers combined the two technologies into one.
Microarchitecture hydrogel membrane material can collect water by generating solar vapor and collecting mist. They are two independent processes that typically require two separate devices. An article about this material was published in the journal Nature Communications.
At night, low-lying clouds along the coastline are filled with water droplets. Devices capable of collecting these droplets and converting the mist into drinking water.
Recycling solar steam is another method of collecting water. It works especially well in coastal areas as it also purifies water at night and during the day. In this method, the sun’s heat causes the water to evaporate, which can be condensed into drinking water.
“Water scarcity is a huge challenge that humankind will have to overcome as the world’s population continues to grow,” says Julia Greer, professor of materials science, mechanics and medical engineering. “Water covers three quarters of the globe, but only about half a percent is available fresh water.”
Researchers have devoted their careers to the development of micro and nanoarchitectural materials, that is, materials whose very shape (controlled at each length scale, nanoscopic and microscopic) gives them unusual and potentially useful properties. In this case, they created a membrane from an array of tiny thorns that resemble Christmas tree decorations, but are actually inspired by the shape of the thorns of a cactus.
In tests carried out at night, samples of the material ranging from 55 to 125 square cm were able to collect about 35 ml of water from the fog. In tests carried out during the day, the material was able to collect about 125 ml of water from solar steam.