Introduction: DIY Artificial Muscle

Picture of DIY Artificial Muscle

Question: is it possible to build artificial muscle using household items?

Hypothesis: if polyethylene fishing line is coiled tightly, then it will be able to condence when heated because the tight coils will try and unwind when heated

Hi my name is anders and I have always loved the idea of exoskeletons, robots, and petty much anything that moves mechanically. Exoskeletons especially, they always seemed to be the coolest. The idea of being able to run faster, jump higher, or even lift a car above your head is awesome. One of my dreams is to be able to build one of these exoskeletons to do all those those things (besides lifting a car above my head, probably not going happen), so I've been doing quite a bit of research. I've looked into hydrolics and motors, but both are big and bulky and a bit out of my price range. I kept looking, and looking until finally I found something that would work, carbon nano tubes are ultra light and very small and compact, they are also extremely strong. Why does this matter? the university of Texas, dallas recently discovered that carbon nano tubes contract when an electrical current is passed through them, quite ingenious if I do say so myself. There is one problem with carbon nano tubes though, they are very difficult to make and aren't being sold, at least not to my knowledge. There I was back exactly where I started, square one, no other way to go, so some time went by and I went on YouTube and typed In "artificial muscle" and in the auto complete section below the box it said "artificial muscle fishing line", curious I clicked on it and found a pretty interesting video that I decided to watch it was an animation of a line being spun until it sarted forming coils, then it showed it stretching and then contracting. I watched some more videos and found out that these are extremely cheap and easy to make, assuming you've used a drill before. I also found out that their contraction strength was stronger than carbon Nanotubes and they were a hundred times stronger than a human muscle of equivalent size which is awesome. Another thing I learned was that they were made by the same university that makes artificial carbon muscles, this was very exciting for me because a would now be able to build these, and build a cheap exoskeleton at my house (if I can find the time).

Why did I build this and put it on instructables? The reason I built this was because there wasn't very many sources to get the info on how to build this. I also made it because I wanted to build a cheap, but effective replacement for motors and hydraulics.

Thank you for all your support, and tips to help me improve my instructables. Without you guys I wouldn't be doing this right now, you should expect many more indestructible in the future so don't forget to subscribe to me and/or favorite this instructable. If you have any question or concern then be sure to comment, or if you just want tell me how awesome this is that's fine too. Here it is, hope you enjoy it. Don't forget to vote for me, thank you.

Step 1:

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to make this, you will need a few basic things:

  1. Fishing line, this is what our muscle will be made of
  2. Wire to hang the drill up, if you don't have a mounted drill like me
  3. A pen or thin tube, to keep the line straight and to prevent it from spinning out of control
  4. Warn, if your making a large one that expands and contracts with heat
  5. Copper wool, if making an electrically powered one
  6. Paper clips or pop can tabs, to tie the line on to
  7. A drill of any kind
  8. not shone, a lighter and a place to hang the drill up

Step 2:

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if you don't have a mounted drill then this step is a necessity. Take some wire and hang it up some where

Step 3:

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put your drill on the wire and balance it out, it is crucial that you make it level.

Step 4:

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take a three foot piece of fishing line and hold it inside the drills bit holder, make sure that it's in the exact center, or else it will affect the quality of the muscle.

Step 5:

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on The other end of the line use the two half hitches knot to tie on the paper clip or the pop can tab.

Step 6:

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take some sort of weight (I used a flash light) and attach it to the other side of the paper clip, this weight will keep the line straight while you spin it.

Step 7:

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In The picture you can see what I did with the pen, I stuck it through the paper clip to hold on to.

Step 8:

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to make the coil you will need to hold the pen In one hand and push the button on the drill with the other. At first it will be slow but slowly, it will start shorten until it starts coilling than it will go really fast so you need to watch it carefully.

Step 9:

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practice makes perfect. If at first you don't succeed try try again.

Step 10:

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once your coil is all ready and at the desired length, then you will need to heat treat it. Do this by taking a lighter and quickly waving it across the line. You should go fast enough that It doesn't melt it, but slow enough so that it dosent put the flame out.

Step 11:

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this is what it should look like when your done.

Step 12:

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in one evening I made 10 of these, so I decided to make a combo muscle which is a bunch woven together

Step 13:

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start by lining them all up one Inch apart while hanging down from something, and on one side tie a piece of yarn to the paper clip.

Step 14:

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next weave the yarn in between the individual muscles, going back and forth.

Step 15:

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here is a diagram I drew up if you need it.

Step 16:

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once you get to the end your finished and are ready to test it, this can be done be hanging it up outing some weight on it and blasting it with a heat gun, a hair dryer won't do anything except make you look silly, so don't use a hair dryer!

Conclusion: I believe with this instructable I have proven that it is possible to make artificial muscles I. Your home cheaply and efficiently.

Final thoughts: In the future I might use copper wire instead of warn so that I will be able to electronically contract these muscles, to make them more efficient and easier to use

Thanks for taking your time to look at my instructible, and I would like to say thank you to every one who has given support and has encouraged me to make more instructibles. if you want to see many more things like this then be sure to follow me. If you made this yourself then I want to see it, leave a photo in the comments below, and For all my followers I say thank you for the support. Don't forget to vote for me, thank you.


杰思 (author)2017-01-22

I had used different diameter of nylon fishing line to build artificial muscle. However it won't contract whenever i heated it. I built it according to your steps but it still don't contract. Did you miss some detail that I must obey in this page?

iskanderus (author)杰思2017-04-06

It works :)

AdrianM222 (author)2017-04-05

I know that how to cold down the fibre is the problem. But.... Why don't use an alternative fibre? For example, use one to open a hand and other one to close it. That way you will reduce the reaction time by half and make repetitive movements faster.

AdrianM222 (author)2017-04-05

How fast does it expands and contracts?

SparkyBoom52 (author)2016-08-16

Hey just out of curiosity what Fishing Line did you use?

OliverS78 (author)2016-07-22

Hi Mr,
I am also very interested in this topic and read a lot... My thought: a human muscle is contracting and a other muscle stretch it with the own contraction again, so is it recommendable to do this with it? I would use a coil and electric resistance too, but I dont want to wait up the stretch and a cooling mechanism is a complex thing again. Do you know what I mean?

up645443 (author)2016-02-29

Is it possible to get the muscle to expand and contract without the use of heat, mostly just stretching it by hand, much like a spring motion?

Pure Carbon (author)up6454432016-02-29

Not that I'm aware of, I did a poor job of explaining this and have yet to update this guide, in the mean time I'll link you to a blog that explains these perfectly!

twiz.graal (author)2015-03-24

I have actually been developing a new concept of prosthetic hand using this technology. Although I do realize that this is not at the peak of artificial muscle fiber technology, I plan on doing extensive scientific research regarding the fishing line technique. I'm positive that this concept will give rise to new developments, of which I will use to update my relatively new design.

twiz.graal (author)twiz.graal2015-03-24

All I need to do now is get my hands on one of those damn 3D printers x_x

There is a 3D printer out there called the peachy printer $100! The Peachy Printer - The First $100 3D Printer & Scanner | Peachy Printer Kit

k-labit (author)twiz.graal2015-12-18

You can buy a kit for about $300 nowadays. I got a prussa i3 off of ebay for

~ $280.

has had some problems that I have needed to fix, but the price made it
worth it. If you are not able to purchase a printer, you could try to
find a makerspace that has one.

Pure Carbon (author)twiz.graal2015-03-26

I know right! I've been entering contest after contest trying to win one, but so far no luck.

Pure Carbon (author)twiz.graal2015-03-26

I've done quite a bit of research on these. I've created an equation to calculate how much current is needed to heat a steel wire of a certain length to get about 150f (which is the ideal temperature for contracting these). The only reason I'm doing this research is because I'm building an exoskeleton which I hope do do an instructable on in the future, where I will release the code for the arduino that I have controlling The muscles. This will hopefuly all be released this summer.

-Thanks for your comment twiz.graal

k-labit (author)2015-12-18

This is pretty cool. I am going to try using it for animatronics. It will be nice to get rid of the obnoxious motor sound. It will also make the movement more realistic. BTW you got a favorite and a vote if you decide to enter a contest.

agu3rra (author)2015-09-27

Thanks for the tutorial. Here's the original article journal published on this topic at AAAS if you'd like to share:

Link to presentation:

I really liked the idea of using silver coated fishing line so that the muscle can be actuated electronically, but I haven't found any available locally. I recently bought carbon paint, which is primarily used to recover PCB damaged trails, so it's an ink that conducts electricity. I'm planning on using it to see if I can overcome the fact that no silver coated line is easily found.

Good luck in your projects. :)

Best regards,


iskanderus (author)agu3rra2015-10-03

Andre, why did you choose silver coated nylon (or equivalent), rather than heating the wire? I know that silver coated nylon has live cycle 7000 only.

agu3rra (author)iskanderus2015-10-04

Hello. It's because one can actuate the muscle by simply passing electrical current thru it. Didn't know about its lower life cycle. This is probably the researchers at the Univ. of Texas used carbon coating on a nylon wire before twisting it.



iskanderus (author)agu3rra2015-10-22

Silver painted nylon (not carbon) is overheating due to rigid nature of metals which crack under too much deformation. That's why silver painted nylon has not so long life. I am using wire wrapped over nylon fiber.

iskanderus (author)2015-10-03

One muscle vs double muscle alternately contract and relax. Simply twisted nylon fishing line with copper wire. There is only one major problem - cooling. This dramatically reduces the possibility of using these muscles in robotics.

iskanderus (author)2015-09-07

Experiment#3 with thermoactive polymer artificial muscle: load 200g, contraction 1 cm, length of muscle 7cm, speed 625ms.

iskanderus (author)2015-09-02

DIY contracting muscle

iskanderus (author)2015-07-07

Can anybody show the video with contracting muscles? Your own video.

iskanderus (author)iskanderus2015-07-07

I can

FlorianK2 (author)2015-05-31

which diameter of nylon did you use?

dullsome (author)2015-05-15

Hello Mr.Carbon:

I am extremely curious about the principle of the shrink when the "muscle" is being heated.Could you please explain it for me?Thanks a lot!!!

Pure Carbon (author)dullsome2015-05-15

Basically, the way I understand it is the muscles are coiled extremely tight and when they are pulled/stretched gaps are created between the coils. These gaps unwind the line a bit causing the coils to try and rewind it, but they can't due to the force pulling them apart. This is where the heat comes in, because of nylons unique properties it rewinds itself more causing the muscle to work against gravity and contract or shrink. I hope that this was any help answering your question, if you have any more then please feel free to ask them.

-Thank you

danny.taylor.5667 (author)2015-04-06

nano muscle should be used in the military for thair TALOS armour

That would be cool, but the only problem is how new the technology is.

JeffreyW (author)2015-03-26

How about interweaving nichrome filament to add a heat source?

Pure Carbon (author)JeffreyW2015-03-27

Nichrome would defiantly work, this upcoming week I was planning to start steel wire tests, then I think I will move on to testing Nichrome wire and report which one works better here on this page. I will also make a video about my findings on my YouTube channel.

-Thanks for the comment

kik (author)2015-02-27

I have made some of these back when it was annaunced in the media, I had very nice results operating the muscles with boiling hot water. Contractions are large and strong.

Pure Carbon (author)kik2015-02-27

I use steel wire and a battery to contract these. I'm currently working on an exoskeleton using these which I hope will better explain how these work and show some real world applications for these for YouTube video.

kik (author)Pure Carbon2015-03-11

Please share a link to video when you are ready. And can you share details on wire and current/voltage you using to actuate them? Keep up the good work.

Pure Carbon (author)kik2015-03-11

Absolutely, it will be coming out within the next month or so. I've been extremely busy so I haven't been able to make the video. If you subscribe to me on YouTube I can guarantee that you will be one of the first people to watch it. I've made an equation that will allow people to calculate how much power is required to produce a certain amount of heat if they know the length and the Gage of the wire. I thank you for your patience with me.

RandomIdeaMan (author)2014-05-16

nice explanation.

I heard about this on a podcast a month or two back, but haven't had a chance to play with it my self yet.

If you use copper wire (as you said at the end) rather than yarn would you be able to heat the wire to make it contract? Or would the stiffness in the wire be too much for the fishing line to over come?

thank you for your comment, I haven't tried it yet but I'm assuming that the fishing line was condensed when you put It on, the weave would allow it to stretch and still pull the weight. Just be sure that the copper wire at a low gauge and is coated, conducive thread might work as well.

iskanderus (author)Pure Carbon2015-01-31

I am sure your muscule does'nt work.

Pure Carbon (author)iskanderus2015-02-01


iskanderus (author)Pure Carbon2015-02-03

On the video from Texas the process of contractions was very slowly. There are lots of additional conditions to each strand can be contract. And about step 10. It seems to me "step10" kills the ability to contracting.

Pure Carbon (author)iskanderus2015-02-03

Have you done any research on these at all? The reason they contract is because of the tight coils that are constantly trying to unwind. Because they are wound in the opposite direction that the muscle is trying to unwind, the two forces are equal to each other so they stay nutrally balanced. This is what keeps them in the nice coils. When heat is applied to them the coils try harder to unwind, but because of that opposing force they can only; you guessed it contract.

You also said "There are lots of additional conditions to each strand can be contract." What conditions?

iskanderus (author)Pure Carbon2015-02-03

I also read a theory. I've been watching these studies a year. And yes, I'm trying to repeat the result. Nothing interesting comes out. And by the way, "the performance of each coil can be varied based on the weight applied to the end of the cord during twist insertion, and, of course, by the total number of twists" (conditions).

Grall (author)2014-10-28

I like it. But I how fast can the contractions be? Does it speed up with a more abrupt application of heat? Conversely can it be slowed down?

Pure Carbon (author)Grall2014-10-29

It depends on the temperature. I wrapped some steel wire around it, hooked a battery to it, and it contracted very quickly. If I had to guess with more wire there would be less heat making it contract slower

stormneel (author)2014-06-27

How much can it lift?

Can this also be used run faster and jump higher?

Pure Carbon (author)stormneel2014-06-27

thank you for you question. It can lift a hundred times more weight then a human muscle of equal size, so if you were to make an exoskeleton using these then you would be able to run faster and jump higher, some advantages this has over things like motors or hydrolics is that it's lighter, cheaper, stronger, and contracts and expands better. If your trying to build an exoskeleton then I strongly recommend using this.

nerfrocketeer (author)2014-05-16

Haha cool!

thank you.

rimar2000 (author)2014-05-16

Good work!

Pure Carbon (author)rimar20002014-05-16

Muchos gracias.

About This Instructable




Bio: My whole life I have thought of ways to make things that you can only go out and buy, follow me and I will teach ... More »
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