The humidity-driven flexing of a spore-covered piece of latex rubber (right) drives the movement of a magnet, which produces electricity (Photo: Xi Chen/Columbia University)
As Bacilli bacteria dry out and form spores (shown here), they wrinkle, and as they rehydrate, they swell (Photo: Xi Chen/Columbia University)
Ozgur Sahin believes that water evaporation is the largest power source in nature. In an effort to demonstrate the potential of this untapped resource, Sahin and his fellow researchers have created prototype electrical generators with rubber sheets that move in response to changes in humidity thanks to a coating of bacterial spores.
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