Nitinol as magic wire?

I see a lot of videos with nitinol, where shape memory effect was presented. Wire is deformed when cold, and returns to original shape when heated. Also hot water can be used, instead candle flame.
Here is short video, which I made.

Question is, how it works in microworld.
Nitinol exists in 2 solid - state phase. At low temperature (room temperature) exist state called martensite (monoclinic crystal structure). At high temperature (around 90 °C for my wire) nitinol is in austenite state (cubic structure).

During room temperature, Nitinol is in martensite state and has monoclinic structure. During deformation, crystalic structure making internal strain. When nitinol is heated, structure change to cubic structure. Nitinol decrease strain by returning to original shape.

Posted with STEMGeeks