If dry bacteria spores of the genus Bacillus were boxers, commentators would say they punch above their weight.
When they dehydrate, the rod-shaped spores— dormant cells that help the microorganism survive tough environmental conditions and are naturally found in soil and vegetation—shrivel or curl like a leaf. Add some moisture and they straighten out again. Studies have shown that they can absorb water and expand with remarkable force. Now scientists say this phenomenon can be harnessed to use the microbes as a potential source of renewable energy or as muscles to make superstrong robots.
In research recently reported in the journal Nature Nanotechnology, a team detailed how they smeared spores on a flat piece of rubber and created a bacteria-powered generator.
Researchers have built an electricity generator that can harvest energy from the most gentle movements. They say their device can produce a steady current to power consumer electronics using a gentle breeze, flowing water from a tap or normal body movement.
The Georgia Tech and Chinese Academy of Sciences team, led by materials science and engineering professor Zhong Lin Wang, report the generator creates electricity by harvesting static from a rotating disc that rubs against another stationary one. This static electricity generation, a phenomenon called the triboelectric effect, is the same that causes people who have shuffled their shoes across a carpet to get a shock when they touch something else.
Their work is reported in the journal Nature Communications today. In it, Wang’s team demonstrates the hand-sized triboelectric generator (TEG) recharging a smartphone and powering LEDs, a digital alarm clock and a wireless transmitter. They say the four-inch-diameter device is already sufficiently low-cost and energy-dense to operate electronics and could be ratcheted up to large-scale power generation.
Click through for more images and to see how much power the device puts out.