Nitinol Nickel titanium, also known as Nitinol, is a metal alloy of nickel and titanium, where the two elements are present in roughly equal atomic percentages. Nitinol alloys exhibit two closely related and unique properties: the shape memory effect and superelasticity. Shape memory is the ability of nitinol to undergo deformation at one temperature, stay in its deformed shape when the external force is removed, then recover its original, undeformed shape upon heating above its "transformation

A Nitinol wire returns to its original, pre-set shape after being heated due to a phenomenon called the shape memory effect. This ability comes from a reversible, temperature-dependent change in the material's atomic structure, not from a simple expansion or melting. | Fadhel Mahdi

Thermobile http://physicstoys.blogspot.com/p/physics-toy-store.html Nitinol wire loop heat engine- 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