Nitinol paper clip returns to form after bending - GIF

[Jon]

After a little poking around, I believe that there are different methods to imprint a form, usually involving very high heat. The shape changing has something to do with shifting among different crystalline structures. More: https://en.wikipedia.org/wiki/Austenite , https://en.wikipedia.org/wiki/Martensite

I searched for "nitinol" at the US patent site; 69 patents listed: Patent Database Search Results: TTL/nitinol in US Patent Collection. Looks like the most common use is in medicine: stents, catheters, suturing tools, etc.

Some example patents:

Nitinol Ring Marmon Clamp


Nitinol Ice Blades


Nitinol Loop Suture Passer


Flexible Drill and Method of Joining Nitinol to Dissimilar Metals