Water purification inspired by a rose

The rose may be one of the most iconic symbols of the fragility of love in popular culture, but now the flower could hold more than just symbolic value. A new device for collecting and purifying water, developed at The University of Texas at Austin, was inspired by a rose and, while more engineered than enchanted, is a dramatic improvement on current methods. Each flower-like structure costs less than 2 cents and can produce more than half a gallon of water per hour per square meter.


Fan and her team experimented with a number of different ways to shape the paper to see what was best for achieving optimal water retention levels. They began by placing single, round layers of the coated paper flat on the ground under direct sunlight. The single sheets showed promise as water collectors but not in sufficient amounts. After toying with a few other shapes, Fan was inspired by a book she read in high school. Although not about roses per se, “The Black Tulip” by Alexandre Dumas gave her the idea to try using a flower-like shape, and she discovered the rose to be ideal. Its structure allowed more direct sunlight to hit the photothermic material — with more internal reflections — than other floral shapes and also provided enlarged surface area for water vapor to dissipate from the material. The device collects water through its stem-like tube — feeding it to the flower-shaped structure on top. It can also collect rain drops coming from above. Water finds its way to the petals where the polypyrrole material coating the flower turns the water into steam. Impurities naturally separate from water when condensed in this way.