Fishing Line As Artificial "Muscle"

brindafella writes "Researchers have made what they describe as an 'almost embarrassing' discovery, that twisted nylon fishing line can form a 'powerful, large-stroke, high-stress artificial muscle' capable of lifting as much as 100 times more weight than human muscles. They twisted the fishing line, then heated it to 'set' the shape-memory. The scientists are from the Australian Research Centre of Excellence for Electromaterials Science at the University of Wollongong, and the University of Texas. The findings are published in Science magazine."

Comments

Fly fishermen have used this property for years

[BitZtream]

I've been using this property to tie flies since I was 5-7 years old ... 30 years ago. It wasn't new then. Admittedly, I never thought about using it or controlling it, but heat treating monofiliment isn't exactly new. Want a tight fly? Heat treat it, then give it a pinch to hold its shape after its good and warm. Use your fingers, not a tool that will nick the line and make it weak, as the heat treating already weakened its tensile strength considerably.

Mono hasn't been around that long so I suppose fly fishermen hasn't been doing it that long either, but still, this property is well known.

If only we had better search tools to be able to find things like this without rediscovering it. Its not wasted research by any means, but it sure does seem like we could make much more progress if we could benefit from the sum of human knowledge rather than the little bit we have domain specific knowledge of and trying to shoehorn everything else into it.

Re:Fly fishermen have used this property for years

[Sockatume]

Suffice to say the process they used is a bit more nuanced than that; I can't link to the paper's figures because of the paywall, but they developed complex hierarchical microstructures of the filaments, and different ones for different applications. (E.g. one structure gives you a fabric with pores that open as it warms up.)

Re:so they invented the spring

[tippe]

FTFA:

Spinks says to use these springs as artificial muscles heat is again applied, causing the whole coil to contract.
Critically, with the ordinary fibres, the amount of contraction is as much as 50 per cent of the starting length of the coil, he says.

That's a little more "muscle"-like than your average spring, I'd say.

Re:Heat is the limiting factor in our muscles, too

[drinkypoo]

Heat isn't the limiting factor here, it's what causes the fibre to actuate.

Yes, but they will have to be cooled in order to de-actuate. The rate of thermal transfer is going to limit the working rate. It's fascinating stuff.

Re:so they invented the spring

[noahwh]

They're not claiming to have invented a unique mechanism. They're claiming to have implemented a useful known mechanism in a low cost material.

Re:so they invented the spring

[Jarik C-Bol]

Reinventing the wheel is exactly what allows us to travel 80mph without even feeling it. The original wheel probably fell apart at about 5mph after 100 yards. Wow they're rubber, self-healing, last 4000 times longer. Whoever intended the phrase "you're reinventing the wheel" to be an insult was an idiot.