Researchers at Columbia University have found a way to collect and harness power from evaporation of water. Ozgur Sahin and his team recently published a paper in Nature Communications’ journal about how it all works.
The technology makes use of the property of bacterial spores, which are like seeds that can germinate into a living microbe under the right conditions. Absent those conditions, however, they are rather good at absorbing water whenever they find it. During absorption they swell and when they lose the water they contract, and they can do this repeatedly, without much wear and tear.
The technology is far from powering our cars, but the proof of concept is developed enough to propel a small lightweight cart.