|A Stirling Engine being powered by dry ice.|
When we think of engines, we think of heat, combustion, steam, electric motors, and the like. The Stirling Engine, invented in 1816 by Robert Stirling, uses the temperature differential between two surfaces to alternately heat and cool air. This pushes and pulls a piston in a cylinder, with the back-and forth motion transferred by a crankshaft to rotary motion. Stirling Engines are very quiet and submarines are powered by this technology.
In addition to heat, the temperature differential can be obtained through dry ice. Small demonstrator Stirling Engines can be powered with dry ice. The video to the right is a perfect example of this. A Science Fair project powering an engine with dry ice may be innovative enough to really impress the judges.
Make sure to follow all dry ice safe handling precautions.