14 DAY TRIAL // Researchers working with the Harvard and Columbia universities say that, according to their investigations into the matter at hand, it is possible to use natural changes in the humidity of a given region as an energy source.
What's more, the scientists claim to have even found a way to harvest the energy potential of evaporating water with the help of a soil bacterium known to the scientific community as Bacillus subtilis.
In a paper in the journal Nature Nanotechnology, the specialists detail that their experiments into tapping into the energy potential of evaporating ponds, harbors and the like boiled down to piecing together several miniature generators.
Thus, a sheet of rubber that was coated with spores of said soil bacterium stood at the core of each of the generators that the scientists created.
When exposed to a fairly low air concentration of water vapors, the rubber sheet dried out and bended. Later, when coming in contact with elevated humidity, it straightened.
The researchers say that this regular bending and straightening of the spore-coated sheet of rubber can be used to generate movement, and that the latter's energy can be successfully harnessed and put to better use.
“The sheet bends when it dries out, much as a pine cone opens as it dries or a freshly fallen leaf curls, and then straightens when humidity rises,” the Harvard University's website reads.
Furthermore, “Such bending back and forth means that spore-coated sheets or tiny planks can act as actuators that drive movement, and that movement can be harvested to generate electricity.”
For the time being, the prototype generators built as part of these experiments only harness a small amount of the energy produced through evaporation.
However, the researchers say that their performance could be increased by toying with the genetic makeup of the spores and getting them to be stiffer and more elastic.
The scientists who worked on this project say that, unlike solar, the energy potential of evaporating water can be harvested night and day, meaning that this power source is more reliable.
“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,” says specialist Don Ingber.
“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,” he adds.
Check out the video below to see how a spore-coated sheet of rubber used in this investigation responded to changes in the humidity of the environment is was placed in.