Synthetic Muscle Made of Fishing Line is 100 Times Stronger Than the Real Thing

by adventured • 12 years ago

186 62 12 years ago

anigbrowl3• 12 years ago

The paper is behind a paywall, but having read the methods and materials, this is a Very Big Deal. The amterials are cheap, the fabrication techniques are low tech enough that you can do it at home with basic tools, and the pwoer delivery is ridiculous. They've demonstrated it working with multi-kilogram weights. I'm going to buy some fishing line.

philwelch• 12 years ago

Fishing line is designed for hauling up hundreds of pounds of fish when being cranked up with a human-powered reel. It's not surprising that it can be applied in this fashion.

arnarbi• 12 years ago

If "strength" meant tensile strength, this would not be an article, let alone a paper.

The fact that fishing line can be applied this simply to create a "muscle" that forcefully contracts (that's what they mean by "strength" here) - then this is certainly both surprising and remarkable.

mdturnerphys2• 12 years ago

Did you see the temperatures? Unless you're worried about hysteresis you should give shape-memory wire (e.g. nitinol) a try. I've got some .004" (100-micron) nitinol wire that can lift 100 grams.

anigbrowl3• 12 years ago

I thought shape memory wire was very expensive though - a few thousadn $/kg? Though checking nitinol.com, it's certainly cheap enough to experiment with - thanks for the tip.

d23• 12 years ago

Since you seem to know a lot about this sort of thing, any idea how long before I'll be able to put these on my arms?

pavel_lishin2• 12 years ago

If it's controlled by applying heat and cold, human applications might be tricky.

jobu• 12 years ago

How durable are these synthetic muscles? (i.e. how many contractions?) Anytime I've dealt with twisted or tangled fishing line it seems like the strength is severely compromised.

cma• 12 years ago

"It forms a sinewy band that's flexible, dynamic, and can be reused millions of times"

Doesn't say what kind of "reuse" they are counting.

anigbrowl3• 12 years ago

Tested 1m times under load with no degradation (someone kindly sent me a copy of the paper). They talk about the process here: http://www.sciencemag.org/content/suppl/2014/02/19/343.6173....

Bpat• 12 years ago

Run some nichrome wire up the center of the coil and you could heat it really quickly.

rasz_pl3• 12 years ago

or melt it

scotty792• 12 years ago

I was thinking rather, put it in an ellastic tube and pass warm/cool liquid or air through it.

Sharlin• 12 years ago

Pumping electrons vs. pumping (and heating) a fluid? There's a reason we don't use steam engines anymore :)

huherto• 12 years ago

Looks cool!

Are there any applications for this? We can already do the same using pulleys. right?

ajcarpy20052• 12 years ago

Why didn't I think of this?

spiritplumber• 12 years ago

The best inventions leave you thinking "Why didn't I do this?"

Awesome, this looks like it can be done at home.

shearnie• 12 years ago

I wonder what is the potnetial of how quickly it could contract?

If not so fast, but incredibly strong, then I assume you could set it up with cranks and high gearing to make an engine. Like pedaling a push bike with your legs.

graeham2• 12 years ago

They did some tests at 1Hz for >1M cycles.

quarterwave• 12 years ago

Human muscle also stores energy in the form of glycogen, so it's got batteries included. The approx 25% energy efficiency of the human muscle is limited mostly by the 40% efficiency of burning glucose into ATP molecules. The article mentions 'relative inefficiency' of the new muscle - a quick search indicates it's around 1%. My respect for human muscles has increased!

davyjones• 12 years ago

Human muscles are capable of much...(comparable to chimpanzees?). But there is some sort of a governor in place to ensure safety. In extreme circumstances, the governor can be "turned off" (adrenalin?) and we have cases of mothers lifting cars to save her child, etc.

ekianjo• 12 years ago

lifting cars to save her child, etc.

Lifting cars is often an exaggeration in terms of wording, the reality is usually lifting up one side of the car, which is very different in terms of weight.

rasz_pl3• 12 years ago

no safety governor, just fine motor skills by addressing small specific muscle groups, hence unfortunate 'retard strength' myth (trading fine motor skills for blunt force)

Symmetry• 12 years ago

Essentially. IIRC there are a couple of negative feedback loops, one local and one involving the brain, and they usually limit you to about a 1/3 duty cycle for each muscle fiber. There are certainly ways that ratio can be increased, just yelling can increase the maximum force you can consciously exert by about 15%. I have no idea what the maximum is, but I'd imagine that going much further than what you're normally limited to drastically increases your odds of tearing something during exertion.

The reason chimpanzees can exert more force is anchoring, their muscles are anchored to the bone further form the joint so they have better mechanical advantage. A human has a much wider range of movement, though, and I believe we better maintain force under movement. So which a chimp might be able to lift themselves more easily, a human ends up being able to throw a rock or spear much further.

EDIT: Also, ekianjo is right that lifting cars is an exaggeration.

jp555• 12 years ago

Muscle is not the only tissue involved with moving a weight around. Obviously you need a skeleton that can bear the load, and a heart & lungs fit enough to pump adequately oxygenated blood. But don't underestimate the large role a strength-adapted central nervous system plays.

dewiz• 12 years ago

Given that human muscles also grow and self heal, yes we're still long from a better solution 😊

jjoonathan2• 12 years ago

I'd give up growing and self-healing if it meant not having to constantly lift to maintain condition and being able to swap out for a replacement in 5 minutes rather than spending weeks or months crippled while waiting for a self-heal.

We aren't there yet either, but when judging practicality you have to include biology's failings alongside its strengths :)

DigitalSea• 12 years ago

"Bro, do you even lift?" just took on a whole new meaning. This is super cool though, as the article says, I cannot believe someone hasn't discovered this sooner. I wonder if we will be seeing military and or medical applications using similar materials and techniques soon? This could work wonders for rehabilitation.

beambot2• 12 years ago

These have been known for some time; just search for "twisted string actuator". I recall doing a literature survey to see how far back the idea went... Here are a few links...

(PDF) http://www.dexmart.eu/fileadmin/dexmart/public_website/downl...

http://books.google.com/books?id=cDx8_ug_GGgC&pg=PA95&dq=twi...

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=569572...

There are patents dating back to the 1930s, 1970s, and 1980s. In recent years, this is (again) being actively explored by roboticists.

EDIT: My bad! The twisted actuators in this work are using heat (and potentially light / electricity) to expand and contract, not the actually twisting motion.

scriptproof• 12 years ago

I believe you have not read the article entirely. The principle is not to twist the line to contract the muscle, that is made with an actuator, the principle is to apply a current to a mechanically twisted fiber to contract it and produce a movement.

beambot2• 12 years ago

My mistake! From the PM article: "Also, by blending in conductive wire or wrapping the muscle with a light-absorbing coating, the researchers can control the muscles' movements with electricity and light instead of direct heat."

So these are heat-driven actuators (and potentially electricity or light driven). Very cool! Thanks for the clarification. (Also, this isn't at all evident from the Science abstract. I will read full paper tomorrow when I can pierce the paywall.)

runewell• 12 years ago

Can this be used in robotics? I know the air-compression muscles provide some of the best performance for grip and human-like motion but they require noisy heavy equipment and can be costly. Although this solution looks more primitive it makes me wonder if it could be engineered into an effective replacement at a much lower cost and weight along with silence when in operation.

XorNot• 12 years ago

Heat controlled, so you'd need a central heating and cooling reservoir to achieve motion with any rapidity.

x0054• 12 years ago

This has been discussed on the Slingshot Chanel. I am surprised that this has not been explored more until now.

https://www.youtube.com/watch?v=f3t2_AX8HUk

daralthus• 12 years ago

Somebody who read the paper, can you tell us how much was the achieved length change? It doesn't seem that much in the video.

graeham2• 12 years ago

49%, from the abstract, although this is an extreme in their results.

Quite an impressive application actually. It has quick actuation, large force generation, and large displacements. Typically these "muscle replacements" are lacking in at least one of these and thus make them impractical outside the lab.

tomp• 12 years ago

Wow, that actually makes it useful, unlike what was shown on the video.

marcosdumay• 12 years ago

And cheap. Don't forget cheap.

Looks like it got everything.

bane• 12 years ago

So now the entire field of artificial muscles is going to change to find materials that do something like this, but better.

I love how the video shows you how to both make the muscle fiber as well as shows it working under load.

tlarkworthy• 12 years ago

Not mentioned in the article but highlighted in the paper is that this actuator has no hysteresis. If you have played with shape memory alloy, you will know the non-linearities in it are extremely hard to perform control with. So this is a big advantage of this actuator over SMA wire for control.

jrockway• 12 years ago

"Synthetic teeth made from diamonds 1000 times stronger than the real thing."

"Synthetic airplane made from black box material 1000 times more heat resistant than the real thing."

pavel_lishin2• 12 years ago

Would there actually be a disadvantage to having diamond teeth? (Aside from aesthetic issues - I don't want my teeth to literally sparkle.)

omegaham• 12 years ago

One problem is that diamonds are surprisingly brittle. If you tap a diamond along a cleavage point, it will break. Diamond cutters take advantage of this; you can break a diamond with a wooden dowel if you hit it in the right place. I'd be really unhappy if my tooth just split in half because I bit down on something slightly wrong. Of course, regular teeth do that too...

PhasmaFelis• 12 years ago

You'd need to have all your teeth replaced, or the diamond ones would tear up the natural ones.

I'm okay with that, mind you. THE BRIGHTEST SMILE

logfromblammo• 12 years ago

Perfect cleavage in 4 directions.

For teeth, you want nephrite as the base with a thin shell of corundum on the surface.

mrfusion• 12 years ago

Can someone put up instructions for making it?

ilyasimenko2• 12 years ago

Video in the article is pretty straightforward. I have tried it myself with 0.35 mm fishing line, but I haven't got a heat gun, and that was a huge problem. I've tried to heat the coil with lighter, but it's really difficult to control the temperature. If it's too low, coil does not contract, if too high - melts immediately. But one of about ten attempts was successful, so it definitely could be done at home.

IgorPartola• 12 years ago

Do you have a hair dryer? If you can actually use a cheap heat gun, Harbor Freight Tools sells them really cheap in the US.

mhb• 12 years ago

What is the activation temperature (range)?

ChuckMcM2• 12 years ago

Pretty cool, much simpler than Nitonal (aka Muscle wire). Sigh, and another cool thing to build in my "spare" time.

mdturnerphys2• 12 years ago

How is it simpler than nitinol?

ChuckMcM2• 12 years ago

The lack of hysterisis and creep means that you can drive them with and open loop drive system. That is a much simpler system to build.

ajcarpy20052• 12 years ago

Hydraulics could be another solution but better if the pumps are small and distributed and more integral to the overall structure than a large pump for each muscle group.

Synthetic Muscle Made of Fishing Line is 100 Times Stronger Than the Real Thing

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