"Solar steaming" is an eco-friendly form of water purification in which sunlight is used to heat tainted water, turning it to steam which condenses back into liquid. That clean liquid is then collected as drinking water. A new system offers improved performance, and it copies the structure of the rose flower.

  Led by Assoc. Prof. Donglei (Emma) Fan, a team from The University of Texas at Austin started with round pieces of paper that were coated with a black polymer known as polypyrrole – it's particularly good at converting solar light into heat. Those papers were initially just placed flat on the ground in the sunlight, where they showed promise for solar steaming, although they weren't efficient enough for practical use.

    Inspired by a book she had read called The Black Tulip, Fan proceeded to try placing multiple papers together in a rose petal-like arrangement, contained within a glass jar. Tainted water was then drawn up into them through a stem-like tube that extended down into a vessel below.