Thermobile: Nitinol wire loop heat engine http://physicstoys.blogspot.com/p/physics-toy-store.html The memory wire straightens out when heated (contact with heat conducting brass wheel) causing the wheels to spin, providing mechanical kinetic energy from a cup of warm tea water. See previous post for a demonstration of Nitinol wire. ➡️ Follow the link above for info on where to get this device and other amazing items featured here on Physicsfun | Physicsfun