Do you know this engine?
It is called Stirling engine.
Robert Stirling invented this engine system about 200 years ago.
The piston can work up and down by a wide range of temperature.
It must be an eco engine system, I believe.
The engine capacity is so low that it has not been spotlighted .
This Stirling engine, which I have, shows you how to work very simply.
Put it on your hand, and the piston starts up and down by the difference between air and your hand temperature.
It is amazing!
Made by Mr. M, a friend of mine
