By Anupum Pant
Well, this is not really coffee powered, rather heat-from-coffee-powered. This is a Stirling engine. An engine like any other heat engine which converts heat into mechanical energy. For a Stirling engine to work, all you need is a relatively tiny amount of temperature difference on its two sides.
The lower part of the engine setup can be heated using the heat from a coffee cup, and the upper part is exposed to the room temperate. As the lower part of it gets heated, the air expands, pushes the piston. Next, it cools, the air contracts and the piston comes back. This translation is converted to a circular motion in this specific setup. Sixty symbols explains…