RTFA: http://www.nsf.gov/discoveries/disc_summ.jsp?cntn_…

Researchers at the University of Minnesota-Twin Cities are studying a remarkable species of bacteria, Geobacter sulfurreducens, that produces electric current when attached to a graphite electrode or other conductive surface.

Geobacter’s current capability already has been harnessed in so-called “microbial fuel cells” that use bacteria to convert wastewater organic compounds into electricity. Daniel Bond, a microbiologist at the University of Minnesota-Twin Cities, and his team have demonstrated the same phenomenon can be harnessed for use in batteries and biosensors.

A traditional battery or a hydrogen fuel cell requires a precious-metal catalyst such as platinum to strip electrons off the fuel source and pull them onto the electrode to generate electricity. Geobacter requires only graphite, an inexpensive and widely available form of carbon, to accomplish the same feat.
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The similarities between microbes and batteries have been evident to scientists for many years and the idea of using the former to serve as the latter has been around for at least 100 years. The problem was that known species of bacteria didn’t make a particularly good battery. Recently, when members of the U.S. Naval Research Laboratory found that electrodes in ocean sediments could generate electricity, the possible involvement of bacteria was more obvious. This led to the discovery that metal reducing bacteria could catalyze this process all by themselves.

There are uses for remote power sources deep in the ocean for sensors and communications and what a Geobacter battery lacks in power, it makes up in simplicity and efficiency. “There are no moving parts, it just works,” Bond said. Other research groups had made some progress in characterizing Geobacter’s current generating properties.

Move over voltaic cells, human energy consumption just made a new best friend! In all seriousness, though, this is pretty damn cool.