http://www.popularmechanics.com/science/energy/a16045/evaporation-engine/

More than a toy

On average, each pull of the engine creates roughly 50 microwatts. That’s a tiny amount of energy, but it’s enough to generate light with an LED by harvesting the energy of a puddle of water that’s doing nothing but existing at room temperature. Sahin also says that the materials used to make the engine are extremely cheap. Even including the HYRDAs, he says it should cost less than $5 to put together.

Get ya Holden or Ford ute, I’m not raceist, get ya mates to stand on the tail gate and piss off the back and the reaction will push ya ute forwards, if you have a 9 gallon keg on board you can travel a long way, and have a very pleasant journey, give the cops a friendly wave.

Glance Fleeting said:

http://www.popularmechanics.com/science/energy/a16045/evaporation-engine/

More than a toy

On average, each pull of the engine creates roughly 50 microwatts. That’s a tiny amount of energy, but it’s enough to generate light with an LED by harvesting the energy of a puddle of water that’s doing nothing but existing at room temperature. Sahin also says that the materials used to make the engine are extremely cheap. Even including the HYRDAs, he says it should cost less than $5 to put together.

The original “drinking bird” engine powered by evaporation was most popular as a toy, but I’ve always seen it as more than a toy, too.
https://www.youtube.com/watch?v=Yk71GY02diY

Would this be the elusive perpetual motion?

Yeah but does it fly?