Cleaning my considerable stash of accumulated nonsense, I found a booklet with samples of Nitinol shape memory alloy.
I remembered about 30 years ago I wanted to build a small robot arm and it never really worked. The enthusiasm and claims in the supplied booklet were a little over the top. Attaching the wire to an electrical contact and also strong mechanical joint was tricky. In any case it was slow to move.
I see this wire is still being sold... but who uses it here? Or back then? I think it was a fad for a while in Radio-Electronics.