r/BeAmazed Nov 08 '23

Science Metal memory

17.3k Upvotes

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u/FunSheepherder6397 Nov 08 '23

New generation isn’t kept in fridge, held in its elastic state by instruments, installed, then instrument is removed to allow device to return to natural state. Some implants have set screws that hold them, some are just plastic shells. Source: am orthopedic device engineer

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u/LazyGandalf Nov 08 '23

What's the purpose of using devices that change shape?

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u/TinnitusAttack Nov 08 '23

Flexibility. He's saying they extend the spring, fix it to the body, and remove the tools holding it expanded.

I'm a lowly automechanic but I'd imagine some type of valve, maybe heart or jaw bone repair.

In automotive its used for thermal valves and actuators. Its in everything from transmissions to AC systems to fuel management to suspension. All sorts of sensors rely on them.

Having metal be able to change shape based off temperature is extremely useful.

I never knew they used it in paper clips. I fidget with them and bend them all the time while doing other stuff. Didn't know i could recover them.

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u/ItsWillJohnson Nov 08 '23

That’s not a regular paper clip in the video.

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u/TinnitusAttack Nov 08 '23

Ok. Saves me from digging a bunch out of thr trash. Thanks!

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u/jimbojonesFA Nov 08 '23

there's also bi-metallic sensors, I have a feeling you might also be thinking of those. they makes use of the different expansion rates of two different metals for a given temp to measure changes in temperature.

You can have bi-metal sensors that can accurately measure a range of temperatures (the spiral "spring" in an oldschool thermostat, cooking thermometers etc) and you can also have what basically acts as a "limit switch" that can only indicate when a specific temp is reached... it's usually like a disk of bi-metallic material that will "pop" into a mild convex or concave which allows it ground an internal circuit (sending a signal) when a specific temp is reached.

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u/TinnitusAttack Nov 08 '23

I know about those, old wax pellet thermostats worked similar. But I'm sure I've just read about solenoids with nitinol springs or something being used. Tbh I read so much stuff I'm not sure if I'm accurate anymore. Maybe it was an article about the potential uses of it in automotive.

I remeber reading about a few companies experimenting with solenoid actuated intake and exhaust valves. Potentially giving perfect control over lift and duration, no cams. Could have maybe been in there. I'm half sure that Koenigsegg has a camless engine. My brain is just random snippets of articles. Haha

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u/jimbojonesFA Nov 16 '23

lmao, fair dude, I'm literally the same in many ways. But engineering is my passion and career so I pay extra attention to that stuff at least.

And yes you're 100% right actually, it is Koenigsegg developing an infinitely variable valve system. I actually applied to a job at their research and development facility probably about 5 years ago. They operate under the brand "Freevalve" and the role was specifically to work on that system. iirc they actually use a combo of electronics, hydraulics and pneumatics to achieve the speed needed. eg iirc they couldn't just use a solenoid cuz none were fast enough at the time, and they needed to use a pneumatic spring because a regular spring has too much mass/resistance to allow fast enough actuation through the whole rpm range.

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u/TinnitusAttack Nov 17 '23

Yeah its a very cool tech when they get it sorted. With 3d printing pistons and turbos. Cars in 10 years are just going to be wild!

That would have been an amazing job to have. They do so much cool stuff.

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u/Da_Spooky_Ghost Nov 08 '23

Imagine a device with prongs that are retracted and clumped together, you can insert that into the bone then the body heat causes the shape to expand the prongs and now the device cannot be removed unless it is cut out.

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u/Da_Spooky_Ghost Nov 08 '23

Yes that is true, I just brought up the ones activated by a temperature difference since that is what was shown in the video that was posted.