Mind & Matter


Students Devise Water Purification Indicator

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Water purification research team. Photo credit Mary Levin, University of Washington.


This holiday season, it is fitting to remember the less fortunate. The United Nations' World Water Assessment Program indicates, for example, that one billion people lack access to safe drinking water—and over twice that number lack access to adequate sanitation. Although technology has a clear role to play in delivering potable water to all, widespread deployment of water sanitation has been cost prohibitive.


However, four engineering students from the University of Washington may have found the answer to this challenge. Intrigued by a process known as SODIS—short for the SOlar DISinfection of water that occurs when solar heat and ultraviolet rays purify water in plastic bottles—students Chin Jung Cheng, Charlie Matlack, Penny Huang and Jacqueline Linnes sought to overcome a major hurdle: knowing when the water is safe to drink. The team built a small device that detects particulate matter suspended in water. Operating in a fashion similar to a smoke detector, the device blinks when its beam of light is obstructed by particles. When it stops blinking, the water is officially potable.


The device costs only $3.40, although bulk purchasing should drive the price even lower. With financing from a private donor, two of the students have launched a company called PotaVida to mass-produce and promote the water purification indicator. The development of such a simple and cost-effective tool proves that technology need not be complex nor costly to be effective.




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About the Blogger

Blaine Brownell

thumbnail image Minnesota-based architect and author Blaine Brownell, AIA, is a self-defined materials researcher and sustainable building adviser. His "Product of the Week" emails and three volumes of Transmaterial (2006, 2008, 2010) provide designers with a steady flow of inspiration—a 21st-century Grammar of Ornament. Blaine has practiced architecture in Japan and the U.S. and has been published in more than 40 design, business, and science publications. The recipient of a Fulbright fellowship for 2006–07, he researched contemporary Japanese material innovations at the Tokyo University of Science. He currently teaches architecture and co-directs the M.S. in Sustainable Design program at the University of Minnesota. His book Matter in the Floating World was published by Princeton Architectural Press in 2011.