Evaporation Engine Harvests Energy From Water Vapour At Room Temperature Bioengineers at the Columbia University have succeeded in harvesting energy from water evaporating at room temperature. The team led by Ozgur Sahin has developed a tiny, $5 evaporation engine that can drive a small buggy or power an LED. The engine practically uses nothing but water as the fuel and room temperature to function. Following is the photo of the functional engine that measures just about 4" on each side. ? This tiny engine is indeed a breakthrough innovation. The engine has been designed and developed to harvest the energy from natural phenomenon that was mostly ignored so far. The functioning of the engine is even more interesting. Sahins team employed hygroscopy-driven artificial muscles aka HYDRAs to power the engine. The HYDRAs are very tiny plastic strips that expand and contract based on the humidity in the air. A small band of HYDRA can have about a million+ expansion/contraction cycles wi...