Power-packed bacterial spores generate electricity

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.