Anglers casting their lines last September into a Montana creek may not have noticed, but a diminutive power plant was churning away in a shallow spot by the shore. The device generated electricity—with the aid of river-dwelling bacteria—to power a sensor system that wirelessly transmitted data to a receiver about 10 miles away. The underwater device, small enough to fit in a person’s hand, was the first attempt to power such a system with a microbial fuel cell.
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Microbial fuel cells take advantage of the long-known fact that some microbes produce electricity when they break down organic matter. Only recently, however, have scientists discovered that they could tap into this energy in a practical manner and use it as an alternative energy source.