Get Your Science On: Nifty Nitinol
Check out this nifty experiment: nitinol is a nickel-titanium metal alloy with a remarkable property: shape memory! You can bend a nitinol wire with ease, but when it’s warmed with a hair dryer it regains its original shape!
How to Build It
Nitinol, sometimes sold as Memory Wire, is widely available online. All you need is a way to heat the nitinol wire: a hair dryer or cup of hot water work well. You can “program” a new shape but heating the wire to an even higher temperature in which is glows red hot.
What’s Going On
Nitinol wire undergoes a phase transition between two different structures of solid. At high temperatures, it forms a rigid crystal called the “parent phase”, while at low temperatures it forms a more flexible crystal structure called the “daughter phase”.