27 Jan 2014:
Changes in Humidity
Are Used to Generate Electricity
Bacillus subtilis bacterial spores
Researchers have created a new kind of generator that uses bacterial spores to harness the untapped power of evaporating water.
Scientists from Harvard and Columbia universities have created small, prototype generators by coating a sheet of rubber with a soil bacterium, Bacillus subtilis
, that greatly expands and contracts with changes in humidity. Building a generator out of Legos, a miniature fan, a magnet, and the spore-covered sheet of latex, the researchers used the humidity-driven flexing of the rubber sheet to drive the movement of the magnet, which generated electricity. The developers of the potential renewable energy technology said that large electrical generators could one day be powered by changes in humidity from sun-warmed ponds and harbors. The scientists said that moistening and then drying a pound of the spores produces enough force to lift a car one meter. “If this technology is developed fully, it has a very promising endgame,” said Columbia University researcher Ozgur Sahin.
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Tribal people and ranchers join together to stop a project that would haul coal across their Montana land. Watch the video.
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An aerial view of why Europe’s per capita carbon emissions are less than 50 percent of those in the U.S. View the photos.
The 2015 Yale e360 Video Contest winner documents a Northeastern town's bitter battle over a wind farm. Watch the video.
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