Researchers from the Wyss Institute of Biologically Inspired Engineering at the Harvard University developed a new prototype of an electric generator which uses bacteria to generate electricity.
The prototype is powered by alternating the humidity of the environment between the humidity levels of a misty day and that of a sunny day to cause the sheet of latex rubber, which is covered with spores, to straighten and bend. The generator will work by using the movement of the sheet of rubber. The back and forth bending of the sheet of rubber coated with spores on one side can be used to generate electricity.
"If this technology is developed fully, it has a very promising endgame," said Ozgur Sahin, Ph.D., lead author of the study and an associate professor from Columbia University, in a press release.
Sahin and his colleagues studied a soil bacterium called Bacillus subtilis which wrinkles as it dries out much like a grape wrinkling to form a raisin. However, unlike grapes which cannot reform into raisins, the bacterium will be able to assume their original shape after they have access to moisture.
They discovered that changing the humidity is enough to initiate the movement of the spores, and a spore-coated plank can generate as much as 1000 times force as the human muscle. Sahin has to experiment with other materials for the actuator but he concluded that rubber is more promising than silicon and plastic.
"Solar and wind energy fluctuate dramatically when the sun doesn't shine or the wind doesn't blow, and we have no good way of storing enough of it to supply the grid for long," said Don Ingber, M.D., Ph.D, Director of Wyss Institute Founding. "If changes in humidity could be harnessed to generate electricity night and day using a scaled up version of this new generator, it could provide the world with a desperately needed new source of renewable energy."
The study was published in the Jan. 26 issue of Nature Nanotechnology.
