Here is a cool stirling engine powered by your hot coffee and tea. It is a compact design and easily fits on a standard mug. Simply make sure your tea or coffee is hot, and the rest is easy. After a few minutes, the engine comes to life and keeps going as long as your drink is hot.
This tea powered engine doesn’t require any assembly. You can further experiment with this by putting a cup of hot water underneath and small ice cubes on top.