A Columbia University team of researchers have created what is said to be the first ever engine that is driven by evaporation. The engine, in this case, is small and made of plastic and able to power LED lights and similar mild tasks when exposed to a plain puddle of water. The engine is being hailed as a scientific breakthrough, and it could in the future prove to be an inexpensive and effective way to generate useable amounts of energy from commonly found bodies of water.
The team’s work is detailed in a recent study published in Nature. Ozgur Sahin led the team, and has stated the engine — which is made of plastic — costs less than $5 and measures in at less than four inches, making it both compact and inexpensive. As you can see in the video below, all it needs is water poured into a moat of sorts around the engine.
The engine works based on what are essential artificial muscles – something the team calls HYDRA, a new material composed of plastic bands. These bands react to humidity, expanding and contracting when exposed to different levels, and they are able to do so in excess of a million times before the material begins to (very slightly) degrade.
The engine itself works by increasing in humidity when exposed to water, causing the bands to contract. This contraction is used to generate a small of amount of energy from an electromagnetic generator, and to also open vents that releases the humidity, causing the bands to relax and close the vent. This process continues over and over as long as there is water nearby evaporating.
SOURCE: Popular Mechanics