The idea of using energy from the sun to evaporate and purify water is ancient. The Greek philosopher Aristotle reportedly described such a process more than 2,000 years ago.
Now, researchers are bringing this technology into the modern age, using it to sanitize water at what they report to be record-breaking rates.
By draping black, carbon-dipped paper in a triangular shape and using it to both absorb and vaporize water, they have developed a method for using sunlight to generate clean water with near-perfect efficiency.
"Our technique is able to produce drinking water at a faster pace than is theoretically calculated under natural sunlight," said lead researcher Qiaoqiang Gan, PhD, associate professor of electrical engineering in the University at Buffalo School of Engineering and Applied Sciences.
Solar stills have been around for a long time. These devices use the sun's heat to evaporate water, leaving salt, bacteria and dirt behind. Then, the water vapor cools and returns to a liquid state, at which point it's collected in a clean container.
The low-cost technology could provide drinking water in regions where resources are scarce, or where natural disasters have struck. The advancements are described in a study published in the journal Advanced Science.