A black laser-created aluminum panel can purify water containing human waste and heavy metals in accordance with the consumption standards set by the World Health Organization and the United States Environmental Protection Agency for drinking water. , using only sunlight as an energy source .
2 hours for 5 milliliters
Chunlei Guo and his colleagues at the University of Rochester in New York conceived the panel using short-pulse lasers to alter the surface of a 3-centimeter square aluminum foil. They created rows of tube-shaped microscopic grooves in the metal and also tiny nanoscale bumps.
The resulting sheet has a black appearance and attracts water. According to Guo:
If I put a sample [of the aluminum] vertically and put a drop of water at the bottom of the sample, the water will flow uphill against gravity.
When one end of the panel is placed in dirty water, it draws a thin layer of water upwards, which evaporates in the sun, purifying it. By placing the panel inside a glass box, the team collected the evaporated water for use, separating it from the dirty water with a layer of insulation.
It took 2 hours to obtain around 5 milliliters of purified water , so the researchers would like to expand the process to purify larger volumes of water. They also aim to improve the efficiency of the method by making double-sided panels.