On a table in a lab in west London sits a plastic chamber two feet tall, one foot wide, and about three inches thick. It’s divided vertically in half by a thin polymer film: on one side roils a solution of either ferricyanide or buffered oxygen; on the other, nitrogen bubbles through a broth of organic chemicals. And swimming in that nutrient broth are trillions of single-celled microbes, noshing.
What electrochemist Peter Bennetto and his colleagues at King’s College have created in their little plastic chamber of microbes is a battery--a living battery. Harnessed properly, Bennetto says, the energy released by these bugs could one day power everything from wristwatches and automobiles to Third World villages. The potential, he claims, is enormous.
Looking at the latest prototype--a cell the size and shape of a Jeep’s outboard gasoline can, with a meager half-volt of power--an observer might be forgiven some skepticism. But though the device may seem primitive, it’s the product of more than 200 years of speculation and research. The late-eighteenth-century Italian physician
