Nitinol Memory Spring Coil

Nitinol (pronounced 'night-in-all') is an alloy metal, its name stands for Nickel (Ni), Titanium (Ti), and the Naval Ordnance Laboratory (NOL) where it was discovered.

Bend it, then drop it into hot water and watch it return to its original shape! This crystalline metal changes phase around 45 °C (113 °F). You can also retrain this wire by annealing it. First bend it into the desired shape, heat it to a dull red glow along the entire length, and then cool it by immersing it in water. After cooling, the wire can be deformed but will instantly return to its newly trained shape when dunked into hot water!