Researchers Develop Window Screen That Cleans the Air
PALO ALTO, Calif.—Researchers at Stanford University have have developed a low-cost filter that captures tiny airborne particles while remaining largely transparent. The nanotechnology-based system, the researchers say, might someday be used in window screens that would allow light and air to pass through while improving indoor air quality. The technology would function without requiring any outside energy source or costly equipment and ductwork. The scientists aim to capture particulate matter less than 2.5 microns in size—invisible particles small enough to penetrate into the lungs and damage health. After testing their invention on a bad air day in Beijing, the researchers found that it captured nearly 99% of particulates while maintaining 77% transparency. A normal screen has 80% to 85% transparency. After measuring absorption rates, the scientists estimate that, in heavy pollution, such a screen could continue capturing particulates for more than 300 hours. To make it disposable, the researchers envision the screen as a film that could be applied to and taken off a conventional window screen.