Nitinol: The Shape Memory Effect and Superelasticity

Bill demonstrates the temperature-dependent shape memory of nitinol metal. He explains how "twinning" in the crystal structure of nitinol produces the memory effect. He shows a nitinol-based engine that is powered by temperature differences. He closes the video with a description of superelasticity, a phenomenon related to the memory effect, which he demonstrates with a cardiac stent. (This video is dedicated to my second son: born right after the rough draft was finished, and who, thus, delayed the filming of the final video by eight months.)

[@rainbowwarrior6452]

Welcome back, Bill. We have missed you. I hope your family is well.

[@NublaNukes]

Deus Vult. Shhhh, if u want to keep seeing uploads.

[@bobsmithinson2050]

Deus Vult. How is this perceived as a threat?

[@edbigg4554]

Who's Bill? Use inbox

[@michelangelop3923]

@@NublaNukes he should have listen, now there are no more uploads

[@NyanNyanNyanNyanNyanNyanNyanN]

@@michelangelop3923 fuck u i blame u

[@geryon]

Nice to see a new video. It's been a while.

[@engineerguyvideo]

Second son born eight months ago ... appeared just after the draft was finalized, but prevented filming the final video ....

[@jpietersen519]

Congrats!

[@askquestionstrythings]

@@engineerguyvideo congrats on the addition.

[@SlartiMarvinbartfast]

Great to see you back Bill, an excellent video as always. Can we expect more videos in the near future? :) (Congrats on the second son).

[@Tabibito81]

Congrats! I was really hoping you weren't done making videos!

[@Beanpapac15]

One of the most consistently excellent channels on KZbin

[@mx.giraffe1971]

about the consistency...

[@casualbird7671]

@@mx.giraffe1971 ?

[@TantalumPolytope]

@@casualbird7671 his upload schedule is quite whack is what hes trying to say i think

[@engineerguyvideo]

“Whack” is an apt description

[@billgross3579]

So that's how cardiac stents retain their shape! Thank you for this!

[@loddude5706]

As I sit here 'hosting' three of them, I'm pretty grateful - eight years & counting - Nitinol eh? One for the pub quiz : )

[@joandar1]

Lod dude Good for you and the scientists that worked all this out from the metallurgists to the physicians and all of our loved ones even if it only me, lol. Cheers from John, Australia.

[@AbracadabraFC]

It is uncommon for cardiac (coronary) stent to be made of nitinol. It is not necessary due to 316L and L605 alloy, which are more affordable than nitinol, being good enough to withstand the pulsatile strain in the coronary artery. Nitinol stent however is commonly used in areas with high strain or tortuous section like femoral artery, or if removal is desired like in IVC filter. Source: I work in the industry

[@liamwatters2985]

Stephen Abracadabra beat me to it. Most of our coronary stents are cobalt alloy. We do however implant an aortic porcine tissue valve which has a reticulated Nitinol frame and is delivered transcatheter like a coronary stent. Slightly larger catheter though (16F)

[@Preinstallable]

Got in a car crash and had a heart attack when crashing? Save your life and your car! Car gets dumped in hot water and boom its fixed! Heart attack boom cardiac stent

[@MarcosScheeren]

about time… Great, as always!

[@jayemeljay2117]

Engineer Guy!! I've just come across your channel and I cannot believe the quality of your amazing content and explanations. Do you think this will lead to string instruments to stay in tune for ever?? Because that sounds so futuristic that I never even thought it was possible... But this technology should work right? Awesome Engineer Guy? Anyways just a crazy new subscriber that tapped the bell and all just a few seconds into the Titanic and Olympia video!!

[@puppergump4117]

​@@jayemeljay2117 That would mean to tune it you'd heat the instrument to 500 c, which would destroy it.

[@terrafirma9328]

75c, You weren't listening

[@DylanODonnell]

Worth the wait - now off to ebay ...

[@Shanidar1]

Dylan O'Donnell Those "magic" paper clips are quite expensive. $30 for 5!

[@bobert4522]

Cameron

[@GRBtutorials]

Why does your channel name appear as if you were the video creator?

[@engineerguyvideo]

What do you mean?

[@DylanODonnell]

Oh, GRBTutorials .. I think you mean I have a verified tick? All verified creators do.

[@OmegaScathach]

Couldn't believe my eyes when I saw the notification. Best content on KZbin! I watch the aluminium can video like twice a year!

[@markfryer9880]

OmegaScathach Only twice a year. Recommended viewing at least once every month. Preferably with a nice cold beverage in an aluminium can in your hand.

[@micahphilson]

That one really is a pure classic! One of the few science videos I regularly come back and watch once or twice a year, along with Scishow's most deadly chemicals one, their one on the different artificial sweeteners, and the Vsauce Deja Vu video!

[@micahphilson]

Haha! I suggested on Patreon that Cody from Cody's Lab mention this video, and he did! I hope you get a bunch of new fans, I've loved this channel since the instant I found it!

[@poweredbytones]

Im here from cody's lab as well.

[@koodude2313]

In all seriousness, you should switch off Patreon when they erect the new content creator friendly one being made to compete...

[@jayemeljay2117]

I'm here from the KZbin Algorithm finally sending me something awesome!! The Engineer Guy should totally hang out with Destin from SmarterEveryDay... They'd be instant best friends guaranteed!!

[@felixthecrazy]

Years ago, nitinol eyeglass frames in really cold winter air lose rigidity. They almost became floppy. A bit awkward when you'd like them to stay on your face.

[@snaplash]

I've had two Nitinol eyeglass frames snap in the middle of the bridge while just taking them off. It seems that it gets brittle over time with constant flexing. Cool stuff, but I'm not buying any more frames made of it.

[@felixthecrazy]

All of my frames for the last 20-ish years have been 'Flexon' brand nitinol. I had only one pair break and that was at the bridge while I was demonstrating how cool they were, lol. I think they didn't do so well on twisting but fine on bending. But at this point I think only the arms are made of nitinol.

[@hardcase1659]

@@snaplash Why would Nitinol be a selling point for a frame? I really don't see the reason.

[@fornestea7013]

@@hardcase1659 As said in the video, they are pretty resistant towards compression and bending, so if you were ever to unknowingly sit on your glasses, or step on it, the frames would not be damaged. It has its merits, but conventional frames are better if you ask me.

[@hardcase1659]

@@fornestea7013 I bet that using any alloyed spring steel would also be very resistant to deformation. Using Nitinol just doesn't seem like a practical investment.

[@beshtaa]

I never knew about that Nitinol and was pretty suprised when that spring bent itselfe back! But even more suprising is that engineerguy doesnt seem to age...

[@roidroid]

Every year he is heated to 76C

[@stickmanjoe7051]

nice

[@scott8919]

LMAO roidroid

[@Shanidar1]

roidroid That must mean he was conceived @~500 deg C

[@rickrose5377]

@@Shanidar1 I suspect that was the case with most of us.

[@ruready11]

Funny. When was young I had such a difficult time learning due to "focusing issues", but as an adult I'm locked in and understand perfectly and immediately. Thank you for the crystal clear explanations in your video! A new fan in Seattle!

[@jdos2]

YAY! The Nitinol fad is making a comeback! I had engineering samples in the early 80's- such an interesting material! Maybe we can find more uses for it this time around.

[@yellowlght9181]

It's history is even more interesting....

[@joed9849]

Congrats on the baby boy sir!

[@engineerguyvideo]

Thank you

[@kosherkingofisrael6381]

@@engineerguyvideo wait you have a baby, an heir to the engineerguy throne?

[@nichraygun28]

Yes congratulations sir

[@poulosegeorge5457]

@@kosherkingofisrael6381 Yes a true Nazi engineer who works with me to become the ruler of @engineerguy

[@lanog40]

@@poulosegeorge5457 what?

[@pdunbarUNC]

The only channel I allow notifications from!

[@KurtElliott]

I run a news channel so I get notifications from close to 100 channels plus a few other channels...

[@poonannyjones2375]

Kurt Elliott Literally nobody cares.

[@Shanidar1]

Paul Dunbar Thanks for that reminder, I hadn't clicked the bell!

[@Ktulu789]

Maybe you are missing cody's lab, physics girl, the action lab, veritasium, smarter every day, fraser cain, bruce yeany, practical engineering, tom scott, periodic videos, electroboom, engineering explained, steve mould to name a few. They are quite good too! ;) If you have recommendations, I'm interested :D

[@Laogeodritt]

@@Ktulu789 Big Clive for teardowns and detailed explanations of cheap and simple consumer electronic gadgets (he does a lot of dollar store/pound shop electronics for example, or household things like GFCI/RCD units). EEVBlog if you want to delve deeper into electronics-personally I'm watching him less since there's a lot less material geared to the fellow EE, but I imagine his teardowns, dumpster dives, etc., could be of huge interest to the more electronics-oriented hobbyist/curious viewer.

[@hoofheartedicemelted296]

So thorough. I love smart people who hold nothing back, instead of assuming you're too stupid to understand. Awesome. Thank you sir.

[@c3cubed]

To all the young KZbinrs that speak with cringe-worthy nasal tone and vocal fry: Listen to this fellow Bill's superb speaking voice, and learn. During the golden age of television and radio, his cadence and delivery modulation were a prerequisite for any broadcaster. Why is he so good? Simple. Like a great operatic singer, he understands the importance of controlled breathing and using his diaphragm - to elicit a superior resonance and gentle yet commanding tone. A joy to listen to, really, this is.

[@Bman-zn5jz]

It was a joy to read this. Superb use of the English language.

[@lyrimetacurl0]

Nice, but it's better to do it badly than to not do it at all.

[@c3cubed]

Many people tune out when a voice registers like fingernails on a blackboard. Either that, or they're tone-deaf and have tinnitus.

[@Bman-zn5jz]

@@lyrimetacurl0 I disagree. If done poorly one opens themselves up to mockery and ridecule. Then viewers will give their many suggestions on how to do it better . That's if they don't tune out. A few seconds of a poorly made video and most vacate and go elsewhere. Even if the subject matter is relevant and/informative. I remember the old adage. If your going to do something. Take your time and do it right.

[@zarifsafwanhoque4127]

It is possible for one to appreciate the past without having to curse the young under your every breath. This entire website was built by the "nasal-toned-vocal-fried-youth". Don't take it to heart, but you do come off as a cranky old man or one deluded youth with a faulty understanding of the past.

[@DotAHeaD-JamieJupiter-Xander]

Another excellent video depicting the amazing powers of years and years of accumulated knowledge refined, repurposed, and reforged to make human lives better! Can't say enough good things, Bill! Had me glued to the screen every step of the way! Looking forward to the next installment in your video series!

[@craigwright5585]

The production value of your videos is incredible. The topics are oddly satisfying. Great Job!!!!

[@MattRoszak]

It's always a pleasure to listen to this guy talk.

[@m00semanus]

This is one my top three favorite channels on KZbin. The content, presentation, and domain expertise are all excellent.

[@Gimpy2K5]

Always delighted to see a video from you. Thanks again for all the great content!

[@quahntasy]

Nice to see another one of those amazing videos. Was worth the wait.

[@ZJP]

Welcome back, Bill. Thank you for the informative video, as always. Congratulations on the growth of your family!

[@Riotlight]

I can’t believe I have been watching KZbin for years and never come across this channel before! This is one of those channels that I will have to go back and watch every single video. No crap getting in the way. Just clear explanation. Brilliant.

[@LightningSe7en]

Always a pleasure to watch Bill.

[@ssj4gogeta77]

A nitinol demonstration was what made me want to go into the materials side of chem E when I first started undergrad. Still just as fascinating! Thanks Engineer Guy!

[@batsk8]

You deserve much more views. Your "simplistic" way of explaining the nature of our universe is the best there is in any media. Great videos from the beginning. Keep it up! Wish you all the best!

[@shubjero]

Bill, your delivery is incredible. Thanks for these contributions to youtube.. amazing stuff!

[@micahphilson]

Yay! It's so uncommon to see these videos in my subscription feed, it truly is a good day when it occurs!

[@markfryer9880]

Micah Philson I had to look twice at the release day to make sure. Yay a new Engineer Guy video!

[@photolabguy]

What an awesome way to start the day!

[@jopomeister]

Engineerguy! I cannot truly express in a comment how happy I am to see a new video of yours. It is somewhat based on the fact that it's coincided with a somewhat turbulent time in my life, but the largest factor in it is that your videos induce a great feeling of happiness and comfort. Thank you.

[@LarryBordo]

Welcome back! I'm glad you took the time to spend quality time with your family and your new son. Thank you for making this video, it was interesting

[@kylevolkmer394]

The Bob Ross of engineering, I'd love to see you upload more often!

[@matthewwhite546]

Clear and concise, as always. Thank you.

[@NielsBohr107]

Congratulations on the new addition to your family! Glad to see you're back, it's always a pleasure to watch your videos.

[@engineerguyvideo]

Thank you

[@ToTo-hc5vb]

You're amazing Bill. Glad to see you back making these great videos. Hope to watch more of you soon!

[@incubrian]

"I'm Bill Hammack- the coolest damn guy on KZbin"

[@rngsus4002]

Nope hes not

[@__________________________177]

Yes he iiiiiis

[@RCTanksTrucks247]

One of my favorite channels. I learn so much in a short period of time.

[@Nayr15473]

PhD in Materials Science, and I have never understood Nitinol until I saw this video. Thank you!

[@4.0.4]

Love your work Bill. I hope you keep loving it too, and that your life allows you to keep pursuing what seems to be a passion. Not only you teach, you make it fun.

[@srirammusic4033]

Welcome back Sir!

[@roidroid]

I'm curious now to see a SHEET of super elastic Nitinol

[@JagdeepSir7869]

Those who have disliked the video, kindly justify why you disliked such a perfect explanatory video.

[@xgvto5374]

Have missed your videos greatly, congratulations on your second son, and your video is wonderful as always.

[@mohamedzarif4473]

i love it edit Very fascinating!!!

[@kalebhelsley4834]

Cody's lab sent me here, I was curious how it worked after seeing him use it, Thanks

[@fathybalamita1537]

I have watched a lot of videos explaining how Nitinol works, Your video is by far the best explanation of how this metal. Thank you.

[@macrossactual]

Always a treat. Thank you Bill and production team!

[@MrIhba]

Need more videos from you, more than any other videos in KZbin. Please do upload videos more frequent.

[@centpushups]

Did you know you can run electricity through it to make to heat it up too.

[@engineerguyvideo]

I didn't know that!

[@gautamdamodaran]

I was always fascinated about this technology. Thank you very much for this detailed video. I have seen volt meters (kind of) working based on heated nitinol wire. May try googling 'nitinol drive unit Foxboro' for further information :)

[@centpushups]

@@engineerguyvideo it opens up quite the possibilities. Being able to trigger it on command. Came up with the idea for use in a steerable catheter tip. Did not have enough time to develop it but it was exciting project.

[@roidroid]

--Isnt this also the wire thats used for resistive heaters, like toasters? Lots of uses, this stuff.-- _edit: Nope that's "Nichrome" not Nitinol, thx @heyou_

[@MattSieker]

@@engineerguyvideo There's a video by Mike's Electric Stuff where he takes apart a disposable insulin pump, and the pump mechanism used nitinol wire

[@sanches2]

I teach this in one of my classes, but now i will recompose a bit my lecture. This is the most friendly and interesting presentation i've seen up to this moment. Thank you!

[@equalizer1553]

Hope this signals a new era of videos! Love this channel!

[@inverted720]

Great vid and topic.. Quick question, what is the deterioration rate of the metal reshaping back to the high temperature form? Or in other words how many times could it be rated for returning to the high temperature state?

[@thebrainnugget]

Depends on the size, how much it gets deformed, and the Nickle-Titanium ratio. However, as long as you stay within a certain stress percentage, there is little-to-no metal fatigue and it can return to its original shape for a very long time.

[@BenJuan26]

Why doesn't the nitinol spring at the beginning exhibit superelasticity when you stretch it?

[@Yogui3108]

In the case of nitinol specifically, the atomic ratio of nickel and titanium dictates whether it's shape memory or superelastic. A change in about 0.1 at% nickel results in a drastically different transformation temperature than before.

[@alvaro_gavilan_rojas]

How fast you show the concept, in 20 seconds..20 seconds that convinces you to stay another 9 minutes. Thanks for the video!

[@5MinuteEarth]

You are a superlative teacher; I wish to thank you for providing a plethora of material with which I, and many many others, can enhance the mind and knowledge-base. There is certainly beauty in the science.

[@chadwickthezulu]

Did anyone else get optical illusions from the pattern of spheres starting at 1:59 ? If you focus on one sphere, the others appear to move slightly.

[@joraforever9899]

The thumbnail made me believe this is a Nile red video

[@smopoo]

Absolutely brilliant as usual! Thanks for the brilliantly presented info, you and your team are amazing.

[@KainYusanagi]

Always love seeing new videos from you- you always cover such facinating topics!

[@StopChangingUsernamesYouTube]

Protip for any wannabe psychics and people who just want soup to be exciting again: There are spoons made out of this stuff.

[@luigivercotti6410]

My mother would have loved that, so that if I took ages to eat the soup it'd grow cold and the spoon would get all floppy

[@Hans-jc1ju]

How does the efficiency of the nitinol engine compare to a sterling one?

[@0xsergy]

Not very efficient considering the energy lost in heating water. Still super neat though

[@numanumatard]

Id be curious to see how many joules of thermal energy is absorbed to reach max speed. Theres mire efficient ways to heat things, like with current. Niti is resustive compared to other alloys

[@jasongreene303]

It's wonderful to see new work from you, I truly enjoy your efforts. Thank you, and I hope you and your family at doing well

[@jaibacca]

I'm so happy I saw this pop up in my subscription feed. Glad to see you back!

[@KmeierGaming]

ive heard about using nitinol in the "tires" for future vehicles like the mars rover where a tire inflated with a gas isnt an option and because its a "tire" it needs to retain its shape.

[@TheDuckofDoom.]

In the literal sense a thick iron hoop can be a tire, as seen on old horse drawn wagons. I'm not certain of the etymology but I think the term comes from the iron hoop "tying" the other wheel parts together similar to the hoops on a wooden cask, but of course it also served to wear much longer than bare wood and was fairly simple to replace. The moon rovers used woven spring-steel wire tires. Inflation with gas is always an option but repairing punctures and re-inflating could be a bit more trouble.

[@markfryer9880]

wolfedog99 Yeah calling for roadside assistance from Mars or beyond is just a tad too expensive

[@koflropter]

What a coincidence, I've just been watching this kzbin.info/www/bejne/aJ3ZZ4mpZpedgsU

[@taylorwest6986]

Great content, but I could listen to you read a phone book and be transfixed.

[@Guru_1092]

Agreed. Definitely has a radio announcer voice.

[@lordkennedy2410]

He wrote at least 2 books

[@jeffbergstrom9658]

So glad Bill's back! These are some of my favorite videos on KZbin.

[@derponmyherp8005]

I have been waiting for your videos like this for awhile now! Excellent content. Good to have you back!

[@kingsidorak]

BILL! BILL! BILL! Bill Hammack the Engineering guy!

[@Richard-Freeman]

CodysLab! Subbed :)

[@Ualava44]

So happy to see you again sir and as always thank you for the wonderful video.

[@JLoon824]

Great to see a new video from you! Your videos are always interesting and your latest does not disappoint.

[@SiddharthJhakaas]

Here from Cody's lab

[@decasaint532]

Aren't you that one guy without pants??

[@cale0176]

I have never before seen such concise, information packed content in my life before.

[@darshanrai3652]

Nitinol caught my eye with its application in stents and has been fascinating me for a few weeks now. Brilliant to see a video come out about it right now!

[@srirammusic4033]

Are you going to be consistently uploading from now,Sir?

[@engineerguyvideo]

I'll try.

[@srirammusic4033]

All the best👍🏻👍🏻

[@jarettiechroeb1399]

"Not dead" - me for seven months. Finally proven correct.

[@gusmartin6053]

So glad to see you back! Excited for more amazing videos!

[@thiagoaragao636]

Thank you a lot. I've been searching about the subject "shape memory alloys" and had a lot of trouble to understand it. With your video, it all became clearer to me.

[@tsmithkc]

Well isn't this a sight for sore eyes!

[@MasterZiomekPL]

Any1 from Cody's Lab?

[@mumeihozumi8458]

Owo

[@Nill757]

Another superbly described technology. Bill Hammack remains the best communicator of science and engineering on You Tube.

[@nphlelps]

Thanks Bill, we're so glad to have you back!

[@MatuIlMito]

You are alive?!?

[@engineerguyvideo]

Yes ... for now ....

[@ikmnification5737]

I bet Apple has a Nithinol Power Cable developed, but they're not releasing it until they actually need something "new" to add to their product line.

[@TheDuckofDoom.]

I would bet they purposely design cables to have a short life. (And I would make this bet because I know from simple examination of the products that they do this.Their enthusiasm for designed obsolescence, to the point of releasing updates that purposefully hobble otherwise functioning devices, has put Apple into legal trouble in some countries.)

[@Redbikemaster]

@@TheDuckofDoom. you watch Louis Rossmann too?

[@craigtxtx]

Was happy to see a notification of a new video. I love your content.

[@BenDiaz]

Welcome back Bill! Great video as always.

[@edwin3928ohd]

Proud to be FIRST!!!! (it means something for once, haha) Edit : I have looked forward to this for centuries)

[@theSato]

Pleaaase do videos more often than twice a year! They don't even need to be these super premium videos with elaborate examples/graphics, or about an amazing subject. Would be happy just to hear you talk about engineering stuff off-the-cuff without any editing.

[@KinGSiN99]

Great to have you back...we need more

[@OnTheRiver66]

Excellent video. I’ve been fascinated by nitinol ever since I handled a piece and watched it magically go back into shape.

[@hvheerden]

Fascinating property. As always, exceptional presentation.

[@angelcuevas8008]

This video should have a gazillion views. What a great material and even greater explanation!

[@Burilo86]

You are back! Good to see you sir!

[@BenjaminBjornsen]

This is the best presentation of Nitinol and how/why it works on KZbin, well-done. I would love it if you did a video on a variety of nitinol engines.

[@onepercentile]

Nitinol is amazing. Fantastic video delivery!! Very easy to follow. Thank you

[@makatron]

So nice to have you back!

[@miguelbalde1503]

This was a wonderful video! Supremely interesting and your explanations are always fantastic! I'm glad to see you're still making videos!

[@shaxawanchya3310]

Thank you very much. Your videos has been useful. Specially you speak in a very clear good English that non-English speakers understand easily. Thank you very much again.