It is well known that wind and solar hold great renewable energy potential, and we’re beginning to understand more about wave power, but now there’s a new kid on the block. Dr. Ozgur Sahin believes that water evaporation could be the largest power source in nature, and he’s even created prototype electrical generators that respond to changes in humidity to prove it. Keep reading to find out how a spore-coated plank can generate 1,000 times as much force as a human muscle.
In a 2012 study published in the Journal of the Royal Society Interface, Sahin and other researchers discovered how a soil bacterium called Bacillus subtilis not only dries up to become a tough, wrinkled, dormant spore, but can also immediately restore its original shape when water is introduced. When Sahin coated a tiny, flexible silicon plank in a solution containing the spores, it began to bend and straighten in reaction to the humidity in his breathe – before he could even get it under a microscope.
Sahin discovered that the flexible, spore-coated plank could generate 1,000 times as much force as human muscle when the humidity was increased from that of a dry, sunny day to a humid, misty day. Put another way, if you were to moisten one pound of dry spores, it would generate enough force to lift a car 3.2 feet off the ground.
Using LEGO, a miniature fan, a magnet and a spore-coated cantilever, Sahin then constructed a simple humidity-powered generator that produces electricity via the rotation of a magnet being driven by a cantilever that flips back and forth. The prototype can only capture a small percentage of the energy released, but genetically-engineered spores are just one way the efficiency could be increased.
“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,” said Wyss Institute Founding Director Don Ingber, M.D., Ph.D.
Images by Xi Chen/Columbia University