A new device, inspired by a rose, inexpensively collects and purifies water. The device is a new approach to solar steaming for water production — a technique that uses energy from sunlight to separate salt and other impurities from water through evaporation.

Made from layered, black paper sheets shaped into petals, the device is attached to a stem-like tube that collects untreated water from any water source; the 3D rose shape makes it easier for the structure to collect and retain more liquid. The black filtered paper is coated with polypyrrole, a special type of polymer that is known for its photothermal properties — converting solar light into thermal heat.

The water collection and purification device resembles a rose. (Cockrell School of Engineering/University of Texas at Austin)

Single, round layers of the coated paper originally were placed flat on the ground under direct sunlight. The single sheets showed promise as water collectors but not in sufficient amounts. The rose-shaped structure, however, allowed more direct sunlight to hit the photothermic material — with more internal reflections — than other floral shapes and also provided an 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 raindrops. 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.

The system includes a connection point for a low-pressure pump to help condense the water more effectively. Once it is condensed, the glass jar is designed to be compact, sturdy, and secure for storing clean water.

The device removes any contamination from heavy metals and bacteria and removes salt from seawater, producing clean water that meets drinking standard requirements set by the World Health Organization.

For more information, contact John Holden at This email address is being protected from spambots. You need JavaScript enabled to view it.; 512-529-6013.


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This article first appeared in the October, 2019 issue of Tech Briefs Magazine.

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