Lead author of the research, Dr Ozgur Sahin predicts when evaporation energy is scaled up, it could one day produce electricity from giant floating power generators that sit on bays and reservoirs, or from huge rotating machines akin to wind turbines that sit above water. According to Sahin, evaporation-driven engines may find applications in powering robotic systems, sensors, devices and machinery that function in the natural environment.
Water wants to evaporate. It has a desire to evaporate. If you make a surface wet, it will dry up, that's the natural course. What we did was find a way to channel the desire into doing some useful work.
The technology is inspired by the property of bacterial spores, which expand when they absorb moisture and contract when they lose it. Dr Sahin and his team calculated the energy involved in expanding and contracting mixed billions of spores with diluted glue; created a kind of paste and applied it to both sides of a thin, double-sided plastic tape akin to that in cassette tapes—sections of which functioned as artificial muscles or hydra, expanding and contracting with changes in humidity.
With regard to the rotary piston-driven engine, Dr Sahin believes it may be possible to design engines which would require neither fuel to burn nor an electrical battery that use the mechanical energy stored in spores to propel a full-sized vehicle in future.