The manufacturer of this engine maintains a very informative web page. For more info, see the American Stirling Company
Theory: The cycle of heating and cooling air causes expansion and contraction that drives a piston, turning a propellor.
Description: This is a nice motor that makes it easy to see how it works. The motor can be placed on top of a beaker full of hot water, on some ice, or even on a cup of hot coffee or an ice cream cone.
Setup time: 10 minutes.
References: (available in the demo room)