Bacterial spores offer a new source of renewable energy

With mighty bursts of rehydration, bacterial spores offer a new source of renewable energy.

Bacillus spores quickly shrivel in dry times and bloat with a blast of humidity. The transitions, which take about half a second, pack a powerful punch that biophysicist Ozgur Sahin at Columbia University realized could translate to usable energy. By smearing spores onto a flat piece of rubber about the length of a human hand, Sahin and his colleagues developed a spore-powered generator. In arid conditions, parched spores pull the rubber into a curve, while wafts of wet air plump up spores and spring it flat again.

The team linked the rubber to an electromagnetic generator, so that every flex produced an electric current. Since the spores tote such a high energy potential, more than 1,000 times that of mammalian muscle.