Why is Nitinol said to have a fascinating property of memory?

Answer 1

A more extensive answer can be found on wikipedia

Answer 2

When you heat a nitinol wire by passing an electric current through it, instead of expanding like almost every other material when heated, it remembers its earlier configuration and gets shorter. So you can use a bundle of nitinol wires to make an artificial muscle, which contracts when it receives a nerve signal, which is useful in robotics.

Answer 3

I like zee primes answer, I didnt know that