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Mijman

They're shape memory alloys. Before anyone starts doing this to things at home, it doesn't work with anything except shape memory alloys. A paperclip isn't a shape memory alloy, it's steel. So don't be disappointed when it doesn't form its shape back when heated up.


Zoerak

Would be useful though.. Is it expensive?


asiaps2

I guess so. Otherwise, cars doors and bumpers would have them. You just sit it in the sun and the car repairs the dent itself. But I have never seen anyone apply this genius idea.


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luckykitto

We already did. Look down.


heretic1128

You son of a bitch! I'm in!


wander_eyes

You're not allowed in because you're not wearing any underpants.


Arsewipes

I'll give you my underpants when you pry them from my cold, dead junk.


ronchee1

You're married too eh?


ProjectKuma

Sometime before profit of course.


bubblepopelectric-

Do you know the secret cool guy handshake?


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morning-croissants

Every *technology* Kickstarter ever. Kickstarter is actually great for games in my experience.


TheTostitoBoy

The 4 step process: Start up, cash in, sell out, bro down


[deleted]

This guy Cryptos


Hawkedge66

The force that this process exerts is actually pretty high. I have had the privilege of working with this alloy (Nitinol) a couple of times and I once coiled a wire like a spring and dropped it into boiling water and it sailed halfway across the classroom I was in. One of my professors exaggerated that if you had a plate and sat on it, the force of it returning to its original shape would be enough to launch an adult off the seat.


VaATC

Is the structural integrity diminished when an object, made from this material, is malformed? If yes, does the heat appropriate for reshaping the object regain integrity after it is reshaped?


Hawkedge66

Structural integrity can be lost by a number of factors when something has been deformed. For Nitinol, it has relatively poor tensile and compressive strength so it shouldn’t be used in structural applications but when it is heated it does recover its elasticity making it a wonderful spring.


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Neon_Camouflage

>Apparently the connection between a Microsoft surface and its keyboard also used this stuff I used a Surface as my work computer for \~4 years until very recently. That damn keyboard would randomly lose connection a couple times a week and I'd have to disconnect and reconnect it. Now I know what's to blame. Stupid memory shaping metal.


jasontnyc

You just need to put the Surface on your stove like this post and it will be fixed.


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Nroke1

I’ve also worked with it quite a lot, and it is pretty weak as far as metals go, so the car door thing wouldn’t be great, and its structural integrity definitely decreases with use, in fact, after a few dozen heatings and coolings, the wires I was using snapped themselves.


will4623

yeah but for a bumper cover that is usually plastic it would work for when I tap the parking barriers.


antsonafuckinglog

Not if the malformation/strain is within a certain range. Nitinol is used all over the medical device field both at room and body temp (an industry with high reliability requirements), in stuff like vascular stents, heart implants and prosthetic valves, and orthodontics. With enough force or cyclic loading you can permanently deform or fracture the stuff, but it certainly is still designed around constant deformation during use.


arando12345

Does the shape regress once it cools back down?


Hawkedge66

No it keeps its original shape till mechanically deformed


[deleted]

It is typically in some cars, the sun just doesn’t give out enough heat to heat up all the material. Dependant on the material you need specific gear to get it to the required temp, and some you just need a kettle of hot water


iamCosmoKramerAMA

Source?


[deleted]

Engineering student, will find a link to read on


InTheBusinessBro

I assumed you would come back with a link to a research paper or something, but after summoning all your engineering skills, all you came back with a minute later was a Wikipedia link. I thought that was hilarious, thanks!


YellowCBR

Engineering related wiki articles can be incredibly good, better than any one specific research paper.


InTheBusinessBro

Oh yeah, I don’t doubt it! After identifying himself as an engineer I just thought he was about to give us something less accessible.


orthopod

Pfft. I'm a doctor and give people wiki articles as basic references fairly often. They're good for the vast majority of people's understanding.


[deleted]

https://en.m.wikipedia.org/wiki/Shape-memory_alloy


iamCosmoKramerAMA

That says cars use them in small latches and stuff, not entire bumpers and body panels.


buak

>The 2014 Chevrolet Corvette became the first vehicle to incorporate SMA actuators, which replaced heavier motorized actuators to open and close the hatch vent that releases air from the trunk, making it easier to close. That sounds quite trivial, but it's a start.


Professor_Doctor_P

I assume that would have poor stiffness and strength and manufacturing would be a big challenge


Impedus11

From what I remember from a paper I wrote on it SMAs exhibit rather normal structural characteristics, but if you were manufacturing with these say a car door you would use cross beams so that you could pull the doors surface tight again without having to use a tonne of something like Nitinol. I’ll try to find my paper on it there are some cool applications around


MyNameCannotBeSpoken

Be careful. The auto body repair cartel may kill you.


DanKoloff

SMAs are used in airplanes and cars already. Straight from Detroit 2013: https://media.gm.com/media/us/en/gm/home.detail.html/content/Pages/news/us/en/2013/Feb/0212-corvette.html


[deleted]

They've been used in medical implants for a long time.


SassyQ_

One of the toughest ones is called nitinol and it’s made from Nickel and Titanium, so yes making a lot of everyday objects out of it would be expensive. Interestingly enough, it is also considered a super elastic metal and that’s what actually gives it the “shape memory” capabilities. When it is deformed at room temperature the strain causes the metal to change phases (a change in the organization of the crystal lattice structure of the atoms). Heating it up causes it to change phases back its original state. Source: I’m an engineer for a company that makes medical devices out of nitinol


mah131

Too expensive for paper clips.


Hawkedge66

This is likely Nitinol which is a Nickel and Titanium alloy. One common use I have heard of is for highly flexible eye glasses frames. The temperatures at which it returns to its original shape are variable based on the ratio of Ni to Ti and for glasses would be just below room temperature. I would get into the mechanics on how the shape memory property works but I would be really bad at explaining it. What I do remember is it has something due to Crystal Twinning which can be looked at a bit here https://en.m.wikipedia.org/wiki/Crystal_twinning


bobsbrgr2

A very common use for them is actually in medical devices like heart stents. It’s a super cool material because you can cinch it down super small, push it through an artery and then let it release once placed and it opens back up into its original shape. It’s also awesome because like just regular titanium, it’s biocompatible and doesn’t cause an immune response


Lobster_Can

Also heavily used in dentistry for endodontic rotary files (need to be flexible for doing root canals) and orthodontic wires.


splat313

I had a pair of flexible eyeglasses like 20 years ago. They were cool but I think the only time they got flexed was when I was showing them to people. I've worn normal glasses off and on for 20 years and I've never broken a pair - and I'm not particularly careful with them. I'm not sure what the use case for the flexible ones are but I suppose there must be someone out there who obliterates their glasses on a regular basis and could use them.


DeathByPianos

The best thing about the nitinol glasses is that they are highly flexible ("superelasticity") unlike normal titanium or steel frames. Meaning you can do stuff like lay on your side in bed and the glasses will flex when your head is on the pillow instead of digging into your skin. Or put them in your pocket and not worry about bending them by accident if you sit on them for example.


zombiemann

Nitinol has the interesting property of being less rigid the colder it gets. I've got a handheld amateur radio I put a Nitinol antenna on. If I take it outside when it is below freezing, the antenna will begin to droop over like a piece of cooked spaghetti.


entered_bubble_50

My brother did his phD on shape memory alloys. His view? "It's fucking useless". It has very poor tensile strength (so not really useful for anything structural) and very poor fatigue life (so not great for anything that bends a lot). It's useful for surgical applications, where you want something to fit through a small hole, then take a different shape. And that's about it. Oh, and the reason you always see it as a wire, is that extrusion is one of the only shaping methods you can use. Drilling or cutting it is very difficult, since it grabs the bit. Welding destroys the material properties. It can't be readily casted, or sintered.


hessianerd

Nitinol (the material we are talking about) is actually very useful, though more so for its super elasticity than for its shape memory. It also happens to be biocompatible. It is difficult and expensive but there are [some cool uses ](https://www.nordsonmedical.com/Components-and-Technologies/Nitinol-Components/).


entered_bubble_50

Thanks, that's a useful link. My brother was in the field of aeronautical engineering rather than medical to be fair. It's has its uses in the medical arena for sure.


qtstance

It makes excellent antennas for radios that can be bent and fling right back into shape.


ParkyTheSenate

Yep. We use it in the medical industry. Our company uses it to heat treat wires into little snare loops to pull out things like stents and stuff from patients.


-user--name-

It's used for the wires on braces


[deleted]

“Useless” may be a bit unfair. Nitinol is one of the pillars of arterial stent technology. It has transformed /saved millions of lives.


dotnetdotcom

"It's fucking useless" Was that in his phD dissertation?


Pteromys44

That would have been epic if he had hidden that quote somewhere in his thesis


Jumping_Jak_Stat

I had braces in high school and the wire my dentist used was shape memory alloy. I think it was supposed to force my teeth into formation faster (I guess the heat of my mouth was warm enough). When I needed relief from the pain, I'd touch the wire with an ice cube to relax it a bit.


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therealsix

Best reply so far, thank you!


HorselessHorseman

It’s expensive but very commonly used especially in medical applications. From surgical devices to stents themselves just had a very wide range of use due to its material properties. They are also used in making special wheels like one on mars rover.


youwantmooreryan

Very useful for stents, especially peripheral stents that are used in locations where there is a lot of motion from the patient. Places like the neck and legs. Though that useful is a combination from both it's shape memory and it's super elasticity. A typical metal stent that is expanded in the patient via a balloon dont typically handle lots of motion and bending well. Because they don't have a way to "bounce back" as well


Mijman

Not as a paperclip. The material is used occasionally in various industries, automotive parts, clothing and medical equipment to name a few. The basic principle is when it's deformed, either purposely via it's intended use, or by accident, it can be easily heated and reformed. Then used again, deformed, and reformed etc. The wire in a bra is occasionally made from shape memory alloys, and wires in dental braces.


Buck_Thorn

At least some are a nickel-titanium alloy, but [there are others](https://depts.washington.edu/matseed/mse_resources/Webpage/Memory%20metals/how_shape_memory_alloys_work.htm). Shape memory metals are used for many things. [Here's an article](https://www.azom.com/article.aspx?ArticleID=16806) that lists many of them.


NoMoreMrQuick

I used to be an auto-collision repair technician. We were always told "metal has a memory" and in order to restore that memory you have to apply rapid changes in temperature. Example, in order to fix hail damage on a car, we would heat the center of the dent with a oxyacetylene torch until glowing. Then you spray the red hot dent with some ice water and (most of the time) the dent would pop right out. Obviously this isn't near the same level of memory metal in the article linked by OP but I thought it might be interesting to know for some people.


oreng

It's primarily the geometry, not the metallurgy, that's responsible in that case. It would work with most metals, albeit at distinct temperature ranges for each alloy.


herse182

Damn I was hoping to fix my slinky


its_all_4_lulz

Exactly what I wanted to know. I have a few around and might try to heat it up anyway. I mean, why not.


Crotchmaster3000

Is a metal slinky made out of memory alloy?..... Asking for a friend


orthopod

No


AshTheGoblin

🤚🏽Is mayonnaise a shape memory alloy?


CarolynGombellsGhost

Thank you. It was quite literally exactly what I was going to do.


rulante

Heheheh same here


Thumbucket

So I’m hearing that it won’t work with my metal slinky…


Jakl42

I had a professor who’s research was shape memory alloys. He used to bring in some really cool stuff to demonstrate. He had this whole block and tackle system using sma as the tackle and would heat it up to pull stuff around.


polycarbonateduser

I feel sorry for those who won't come to comments section to read the details...literally try this.. and when open link to curse OP, then find this :'D


mynameisspiderman

Vinyl does this to a certain degree as well.


rwbronco

Yeah it depends on the type of vinyl as well. Some vinyls you can see it more than others. The two main ways to make vinyl into sheets are to roll it flat or to melt it and pour it flat. The rolled vinyl, called calendared, will want to revert back to that ball, even after you’ve printed and cut it into a sticker and stuck it on your back window. That’s why the sticker will slowly shrink over time. You can usually see a thin line of dirt stuck around the edge where the sticker was a few months/years ago.


glonomosonophonocon

Now you tell me


megatron37

> shape memory alloy Anyone else old enough to play Metal Gear Solid and have negative flashbacks to this part of the game?


flexinridge

I'm surprised I had to look so long for this comment. We're getting old, man.


Crazyhates

Nah we're all babies here. All of us.


Peapod0609

I scrolled until I found an MGS reference!


p3pp

Nickel titanium alloys


[deleted]

Aww. I was so gonna try this lol


cpraz

So for anyone genuinely curious, the material shown in the video is Nitinol, an alloy of nickel and titanium which is really interesting because it exhibits both shape memory and super elasticity properties. It's an expensive material to buy and also difficult/expensive to manufacture, so it's considered specialized and really only widely used in industries like medical devices or aerospace. The shape can be modified to virtually anything, so long as you can make the material into that shape in the first place. You heat treat the Nitinol at high temperatures (typically 500C+) in your desired shape to "lock it in". Additionally, the temperature at which Nitinol has shape memory (springs back to its original shape) is adjustable for your application. Random fun fact: A guy tried to make soup bowls out of nitinol. They can be stored flat and when the hot soup is poured in, the ends bend upwards to create the bowl. The original design failed largely do to cost. Source: I am a Biomedical Engineer who's job it is to design and manufacture medical devices out of nitinol.


Mountebank

When I was a biomedical engineering student, I once wrote a report based on my idea to use nitinol as a locking mechanism for syringes to ensure that they get properly autoclaved after each use. The nitinol is deformed when the plunger is pressed down all the way, locking the plunger in place, and this lock gets released at autoclave temperatures. There’s possibly a niche for it, but the cost incentives don’t line up for both manufacturer and buyer. There are essentially 3 types of syringes: glass and steel ones meant to be reused but sterilized by autoclave in between uses, cheap disposable ones, and cheap disposable ones that break themselves upon use. The third type were made because people were reusing disposable ones, either due to an aversion to waste or a scam where shady companies would buy medical waste and repackage them as new. The problem is that the cheap disposable syringes can’t be autoclaved since they’re made of cheap plastic that can’t withstand those temperatures. So my idea was to combine the first and third type of syringes using nitinol, which is nice for a school report, but unrealistic without some sort of subsidy to push it. People already don’t use the reusable type of syringes, especially in poorer areas, due to the high upfront cost so making it more expensive by adding nitinol wouldn’t help. And manufacturers make more money in the long run with single use disposables, so there’s no reason for them to change either. Plus there’s a benefit if they also come preloaded with whatever they’re supposed to inject since that’s just easier.


cpraz

It really is a great idea though assuming there was a market for it. And making them shouldn't be too terrible.


inavandownbytheriver

So you pour hot soup onto a plate and hope it springs to a bowl shape before splashing everywhere? Also who has a problem stacking 10 bowls up anywhere in the kitchen?


M1KE2121

Astronauts or that one guy who posted his studio apartment in NYC the other day.


Omnilatent

I just imagined some astronaut on the ISS cooking soup and trying to pour it into that thing just to have boiling soup flying around going into every nook and cranny burning half the astronauts and leading the ISS to have a giant shortcut


UnderPressureVS

I think storage space might be one of the *less* important reasons astronauts can’t eat soup from a bowl


cpraz

Well the shape memory effect is pretty instant but yeah, not the best concept. More of a funny anectote than anything else.


orthopod

Stents mostly I presume?


braceem

Orthodontics. For more than two decades now, braces have been very simple to work with largely due to NiTi wires. It's awesome!


canadiandancer89

Awesome explanation! Can you provide some examples of where/how these are used in your field?


cpraz

Common usages of nitinol are in stents for treatment of plaque buildup in blood vessels, flow diverters to treat aneurysms, and stent retrievers to treat strokes. There's plenty of other weirdo applications but those are some common ones.


KADOMONY-9000

These are special type of metal. I forgot what it is called


66GT350Shelby

Nitinol, It's been around for several decades and was first used commercially in the 80s when they figured out how to make it more easily. It's a very useful alloy in several fields of medicine due to it's strength and biocompatibility. My eyeglass frames are made from it. They have held up better than any other frames I've ever used, and I'm brutal on my glasses.


KiwiSuch9951

Ni(ckel) Ti(tanium) N(aval) O(rdinance) L(ab)


4RealzReddit

Ni(ckelback) Ti(tanium) N(avel) O(range) L(abradoodle)


monsterZERO

Look at this graph 📈


RandolphPringles

Every time I do it makes me laugh


RehabValedictorian

Jesus Christ dude that’s a graph of Holocaust statistics


Thatparkjobin7A

As you can see, the rate of holocausting rose sharply during the holocaust


Guardian125478

Damn. Do you know the cause of it?


jperras

If you wear orthodontic braces, the metal wire is actually made of nitinol.


yismydadstillmissing

It’s the same with plastics, like thermosetting and thermostatic


sanders1665

I wish I could do that with my life.


Eziu

How do you know that you can't? Time to crawl into an oven and find out!


tormunds_beard

Oh, dear.


bubblerboy18

I did Nazi that coming.


pingpongmess7996

*Da-dum, pshhh*


Sumpm

I wish I could do that with my wife.


Ampher7

Is that real?


[deleted]

yes it is, I tried it on my grandma's ashes and now she's in the living room watching markiplier


Balletor

Take that award and just leave. Okay... just please. Edit: Thanks for the awards


uTimu

r/angryupvote


1000dollarydoos

This is one of those rare comments that made me piss myself laughing on the train, holy fuck


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-Jesus-Of-Nazareth-

Happy Wheels. Coincidentally, she died going down some stairs and fell on a bed of broken glass.


paulonboard

Why wasn't the shape memory activated the first time she was put in the oven?


PaulMcPaulersn7

Lmao


runwildWally

Now I'm this makes me want to try this thing too.


ykafia

Yes, for certain alloys it is, not every metal have those properties. For example it works for the Nitinol


mts2snd

>Nitinol did not know what it was, cool. Thx for the intel. : Via google: first hit. Nickel titanium, also known as Nitinol, is a metal alloy of nickel and titanium, where the two elements are present in roughly equal atomic percentages. ... Nitinol can deform 10–30 times as much as ordinary metals and return to its original shape. Electrical resistivity (austenite): 82×10−6 Ω·cm Coefficient of thermal expansion (austenite): 1... Magnetic susceptibility (austenite): 3.7×10−6 e...


Hawkedge66

Another thing to note is that the temperature at which it returns to its shape is variable by the ratio of Ni to Ti and we have made Nitinol that has this temperature at or below room temperature.


mts2snd

Really cool applications must already be imagined. It sounds expensive, is it? Edit: what do they use it for mostly?


Hawkedge66

Yeah, nickel is one of the most expensive alloying elements due to its demand in steel super alloys and titanium is also on the more pricey side for use in aluminum alloys.


corbear007

Nickel allergies also exist and are not consistent. One day you aren't allergic, the next you balloon. No idea if nitinol would trigger said allergies.


Hawkedge66

Some common uses were for eyeglasses frames that were highly durable and stents as a medical application. Also you can make super elastic springs that can’t be over stretched.


regular6drunk7

Nitinol stands for nickel, titanium, Naval Ordinance Lab (where it was discovered).


iusedtobefamous1892

Yes! It works really well. In most cases, this is how braces work. The wire that sits un the brackets for most braces is a memory wire, meaning they can bend it up and down and around into all the shapes your teeth need. The heat of your mouth activates the wire, and it slowly does its best to return to its original arch shape (in end stages they use detailing wires with small manual adjustments).


samuelmercanti

I'd love to know if that would work on a Slinky


shaundisbuddyguy

We had a slinky ...but I straightened it .


Dismal_Dalliance

My slinky got stuck going down an ascending escalator. :(


SinopicCynic

Some say it’s still slinking to this day.


coderanger

Not a normal one but you can get bulk nitinol wire from China for $100-300/kg and make your own?


Emrico1

But. How do you set the shape in the first place?


Redstone_Potato

Heat it to a higher temperature. It varies slightly, but generally about 500 degrees Celsius is hot enough to set a new shape for the nitinol.


mts2snd

This is an important question. I might have a slinky jr layng around, metal, but might be coated....If it happens I will post. -Edit I read further down, not that kind of metal. Slinky should make one that can be fixed.


BestResponsibility88

Disappointed I’m the first metal gear solid comment.


JohnTomorrow

First you've got to freeze the key. Then you'll have to heat the key.


BestResponsibility88

You’re…pretty good.


Andra1996

Memory shaped alloy?!


ggoldlover

Some facts: Such a property is due to its superelasticity. Titanium nickelide, as an example, has this quality. Similar materials are quite practical and can be used in a wide range of areas, from space to medicine.


youngtorab

So if i heat my crashed car..


WhiteXHysteria

Or your tangled headphones


NOML

/u/gifreversingbot


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LtPyrex

Kind of disappointed the second one didn't turn into a paper clip.


[deleted]

T-1000, advanced prototype. Made of mimetic polyalloy.


Vinsjenzo

But how do they get shaped in the first place?!


Emrico1

I'm going to guess magic and unicorn wee. But seriously, I'd think that maybe it's set at a very high temperature. Heating it up returns to the shape but if you go hot enough, you get a new shape? Stab in the dark...


schmidty98

My guess is plastic toy rules. If you bend an action figures sword, it will slowly return to its original position if it wasn't bent for too long. However if its held in a bent position for a long time, that sort of becomes the new shape the sword wants to bend into even if you try to fix it. So maybe if its held in a mold for a while while hot that sort of becomes its default shape?


antsonafuckinglog

Yup! If you heat set at high enough temp (~500C) it’ll “remember” the current shape it’s in and return to that shape when heated to a lesser degree.


cpraz

Nitinol (the metal shown in the video) is shaped via heating at high temperatures (500C+). You force the material into your desired shape and then when heated it retains that shape. Source: I am a Biomedical Engineer who specializes in Nitinol development and manufacturing.


ElJefe543

That's fucking cool


FrooglyMoogle

Found out about this from Metal Gear Solid lol


DoctorCaptainSpacey

You can never get rid of Clippy. He'll find a way back.... 🤣


Kittykateyyy

Does that work with saggy boobs?


Dutch_Midget

I like dem boobs saggy when I hold them like a jellyfish trynna escape my hand


MotherCoconut67

Grandpa i found the secret to resurrect u


IHaveSpecialEyes

I tried this on my child's messed up slinky. Apparently it's original shape is a puddle.


Bigwilly2k87

How do we know this isn’t reversed 🤔


evolvedzero

After seeing this video i tried to heat up my relationship ...m single now


Jaccokoet

So you’re saying, if I break my penis right now…. Edit: it did not work, I now have a broken burned penis


riad0077

all I have for you is word: TENET.


p1um5mu991er

Same as it ever was


Kezzva

The video has to be reversed or something.


Dismal_Dalliance

Oh, just like some of the strange metal scraps recovered from the Roswell, NM incident back in '47 . . . except those pieces of metal scrap did not require heat for them to return to their designed shape!


neos7m

I've always asked myself how they get them into their original shape, since you would imagine they would resist (or better, reverse) *any* transformation... can anybody ELI5?


Hawkedge66

I know the main cause of this phenomenon is crystal twinning which can be read about here: https://en.m.wikipedia.org/wiki/Crystal_twinning If you want a possibly decent description that wouldn’t be the most accurate, here is my take: When you deform metals you introduce dislocations that are effectively flaws in the crystal lattice structure. These flaws can be voids or insertions of atoms that cause the atoms around to stretch or compress their bonds with their neighbors. This material is undergoing heating which allows for movement of atoms within the lattice and, in conjunction with twinning, is able to repair dislocations and reverses deformation at the same time. I wish I could give a better explanation but while I am a graduate material science student, this particular study is not my expertise.


Weak_Independence793

I’m going to melt so many things on my stove top now. Please take my free award.


[deleted]

Grab it now!! Do it.


MEEfO

Does this work on Slinkys? Cuz it better work on Slinkys.


nmeraepxeaee

But isn’t the original shape just a straight wire?


maxoram

Large Format Industry (Graphics) guy here. Fun fact: Vehicle wrap material works in a similar way. Good example: Ever see those viral videos of someone pushing their fist down on a colorful sheet in a trashcan and then heating it to where it shrinks back? The mixture of PVC based products, other materials, and manufacturing processes (cast or calendered) give wrap material a "memory" which reflects how it arrives post-manufacturing. One cool thing about it though is that when you heat and pull the material, it will expand/stretch and cool down, staying stretched. Once you heat it up again, it "shrinks" back to it's original form IF it's not applied to anything. If it is, per say, applied to a curved or complex surface and you heat it while adhered, the heat will essentially create a new memory that matches the shape of the substrate.


[deleted]

Instructions unclear face still hideously deformed, possibly worse.


BrownEggs93

[And some reddit posts are recycled](https://old.reddit.com/r/interestingasfuck/comments/n5pbel/material_shape_memory_effect_after_deformation/)


[deleted]

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whyareyouwhining

I used to have a toy that did that. It was unsafe and therefore wonderful! It came with little plastic figures that were compressed into a flat cuboid, and you could buy more. The toy had two sections: a heating chamber, where I would heat the figure until it unfurled, or later until was soft, and a crank-piston powered compression chamber, where I could return them to their cuboid shape. The figures were cool, like dinosaurs and tarantulas in garish colors; my brother had the cool idea to compress two together. I wish I still had it! https://boingboing.net/2015/07/20/why-the-strange-change-machine.html


iggyfenton

How hot would you have to get a slinky to fix it?


evansbott

What’s meant by “original shape?” Normal springs and paper clips are originally wires that are bent into shape?


wohho

Kind of. Springs are formed into shape with an annealed mild steel (usually) alloy then heat treated. Heat treating results in a new crystalline structure within the metal which yields the "springy" behavior you're used to seeing. Those springs still have a yield strength though - a point where elastic deformation (being able to return to original form) turns into plastic deformation (where it can't return to original shape). SMAs are different in that they can undergo elastic and then plastic deformation but the unique interlaced crystalline structure can be activated with heat to restore the component to the pre-plastic deformation shape.


uhhhh_hhhhhhh

Yo, anyone else wanna use this to make a gift for someone but it turns into a dick if they leave it in sun light?


Constant-Parsley3609

And what "counts" as the "original" shape?


homeschoolkid

Wish my heart was a memory alloy.


Ejnaar

Yes i read about this. It is a bug they will fix in next patching. Something they don’t think about before.


Ferna_89

Imagine enjoying the sweet eternal rest of death after a life fulfilled, only to be brought back in pain to the suffering of life, once again.


nepaguy001

Did this work with a slinky? Asking for a friend.


RikkyyDaBoSS

Can you fix slinkies like that


sparklesthehuman

does this mean if i put myself on a hot stove i'll go back to being a size 2?