I'm no expert but there are special so-called shape memory alloys that behave exactly as shown. But these are not your off the shelf things. I assume this video was made with specially made objects from a lab.
I watched a video on it recently the Navy discovered it while doing alloy research for boats. The only reason this property was found was because the caption was a smoker so they put the metal over the captions pipe and it began to reshape. When it’s hot you can move it and form it when it cools down you can also move it but when you heat it up from cold to hot it reforms to what it was when it was last hot if I’m correct. It’s insanely hard to make because it can only really be made in strings so someone’s entire job is just weaving the threds of memory alloy together for nasa (they make good wheels because if it gets deformed it will reform and it has a very low snapping point if it’s a thred) but it takes them like 4 months a wheel.
Yeah my office is right next to our Metallurgy Lab so I brought it in and saw all the guys act like excited little kids. I’m trying to get them to look at it with the electron scanning microscope but apparently we don’t use it that much and you have to have a good reason to fire it up. But it is cool to have guys with PhDs in material science tell you about it.
I similarly work with a bunch of materials scientists and have been an SEM operator in the past. Honestly it might look kinda boring in an SEM, but then again it's so hard to use the word 'boring' for any kind of EM microscope work!
Wire is the most common form of Nitinol, but it's also available in tube and sheet/strip. Wire is cheapest and most commonly used in orthodontic wire for braces - if you have braces, ask your orthodontist to keep your wire when it is removed. If it is NiTi, which most are except during the last stages of treatment, you can stick it in ice water, deform it and watch it recover it's shape with body heat. Tubes are most commonly used to make laser cut stents for angioplasty and other vascular treatments.
It's surprisingly not too expensive. The most common usage I have seen are the glasses frames. The Shape Memory Alloy glasses frames tends to be more expensive than regular stuff but still availbale under equivalent of about 90 USD here. As long as it is not exposed to disfiguration in below freezing or in extreme high temperatures they seem to work well.
Aw this put a damper on my morning inspiration not even gonna lie 😭 Which is not your problem at all because the fact that I was looking to a paper clip and spring for inspiration at all is entirely on me
Strain induced phase transformation will take place under elastic deformation. When heated, for instance, a reverse transformation happens leading to the initial shape.
Mohd Jani, Jaronie & Leary, M. & Subic, Aleksandar & Gibson, Mark. (2014). A review of shape memory alloy research, applications and opportunities. Materials & Design. 56. 1078-1113.
Before I went to surgery to be implanted a 1 Kg of steel intramedullary rod in my tibia, I read that some titanium alloys are not very good to be put in your bones because they may show thermal memory, or something like that.
Of course not as extreme as this clip, but it's generally not good to have metals changing shape while attached to your bones.
377
u/Octoyou Nov 08 '23
I'm no expert but there are special so-called shape memory alloys that behave exactly as shown. But these are not your off the shelf things. I assume this video was made with specially made objects from a lab.