Researchers funded by the U.S. Army have developed a solar-powered technology that could help solve the clean-water crisis in developing countries.
At first blush, this low-cost device aimed at providing soldiers with drinkable water doesn’t look like much — just a black board dipped into a pond. However, this laser-processed, super-wicking and super-light-absorbing aluminium surface is the most efficient solar-based water sanitation system that exists to date.
So how does it work?
- The aluminum sheet has been transformed into a blackened water-attracting, energy-absorbing surface by applying a burst of femtosecond laser pulses to etch the surface with grooves or channels.
- Placed in a contaminated water source, the aluminum draws a thin film of water upwards over the metal’s surface while retaining almost 100pc of the energy it absorbs from the sun to quickly heat the water. The vaporization has been proven to reduce the presence of common contaminants such as urine, heavy metals and dyes to safe levels for drinking.
- Previously, the most common method of solar-based water evaporation was to heat large volumes of water, which only evaporates the top layer. Instead, this latest innovation pulls a thin layer of water out of the reservoir, saving the energy that would otherwise be needed to heat larger volumes. In addition, the wicking structure of the surface changes the intermolecular bonds of the water which further increases the efficiency of the evaporation process.
- The angle of the panels are continuously adjusted to face the sun as it rises and sets to maximize energy absorption. And — last but not least — the open-grooved surface makes for quick and easy cleaning.