Microbes use mud to make electricity
But a group of US researchers led by Daniel R. Bond have come one step closer to making microbial fuel cells a reality: They harnessed bacteria to generate electricity from underwater sediments.
The microbes make excess electrons that they stick directly to graphite wires, which in turn send current to a second wire very much like a car battery does. These bacterial batteries will probably never power a car, but they should be adequate to run underwater sensors.
Reference: Science, 18 January 2002