Purifying water using the sun is effective, but slow and inefficient. Usually, only the top layer of the water can evaporate. But how about a super-wicking, laser-etched sheet of aluminum? This new method is around 100% efficient, and seems to just work.
The aluminum sheet was developed by a team led by Subhash C. Singh the University of Rochester, and it’s as ingenious as it is simple. A network of tiny, laser-etched capillaries runs over the surface of a sheet of black aluminum. These capillaries wick water quickly over the entire sheet. Because the sheet uses a capillary action, it can be tilted to face and track the sun, and the water still sticks in its channels. Thus, it is always gathering the maximum possible solar energy.
The black aluminum then absorbs the Sun’s heat, evaporating the water and purifying it. Contaminants are left behind, and can be rinsed off with water. The result is pure drinking water, using plain, cheap aluminum sheets that have been lasered.
This could be revolutionary. You can take dirty pond or river water and turn it into drinking water with equipment that is cheap, rugged, and simple. This kind of thing is always touted as being good in disaster-rescue situations, but that’s usually code for “no easy commercial applications.” In this case, it’s easy to see how such a simple and robust device could be essential in the places where water is scarcest.