Self-Healing Artificial Muscles

Valor1016 writes "Researchers in California have developed an artificial muscle that heals itself and generates electricity. 'We've made an artificial muscle that, when you apply electricity to it, it expands, more than 200 percent, the motion and energy is a lot like human muscles,' said Qibing Pei, a scientist at UCLA and study author. The researchers used flexible carbon nanotubes as electrodes. If an area of the carbon nanotube fails, the region around it seals itself by becoming non-conductive and prevents the damage from spreading to other areas. This material also conserves about 70% of the energy you put into it. As the material contracts after an expansion the rearranging of the carbon nanotubes generates a small electric current that can be captured and used to power another expansion or stored in a battery. The research appeared in the January issue of Advanced Materials."

NOT Healing

The muscle does not heal. It shuts down damaged areas "to prevent spread of damage."
 
Typically, "healing" refers to repair of damage, not isolation of damage.

Re:NOT Healing

It sounds similar to the rip-proof diamond weave fabric used for hot air balloons. You can cut/puncture it, but the damage will stay isolated. Still, it's far better than the normal situation in these cases where surrounding material near the defect, because it's all interdependent, becomes weaker and perpetuates the damage.

Re:NOT Healing

Though you are correct, I'm not gonna worry about it too much if its on the nanotube level of things. A few tubes out of commission will hardly keep my massively muscular robot body from raining down destruction upon mine enemies.

Re:

Said like a true super villain, just before the hero exploits your only weakness and unleashes a horde of advanced nanotube-tearing nanobots on you.

Question

I'm no doctor, but...

We've made an artificial muscle that, when you apply electricity to it, it expands

Isn't that backwards?

I have an application

I'm no doctor, but... We've made an artificial muscle that, when you apply electricity to it, it expands Isn't that backwards?

Well, I see great applications in artificial penises. Much better than the pump ones!

Re:

Since muscle expansion and contraction is always referenced in the direction of force, the article disagrees with you.

The power stroke for a biological muscle is the contraction. While these "muscles" are interesting and could have many uses, powering lim

Re:Question

It is the "How do you push rope" question.

In order to be biologically uselfull they will need to be pliant and flexible. If they are pliant and flexible they won't have the tensile strength to move bones around.

Well... Here comes a whole new round of PENIS

SPAMMERS....

If you get them ANGRY...

...Do they turn GREEN and get BIGGER?

Amazing!

Is there anything carbon nanotubes can't do? Every few weeks I read about some new application for those things; space elevators, batteries, muscles, it just doesn't end. I'm honestly impressed.

Self healing?

The system isn't so much self healing as failure resistant. The fact that broken nanotubes seal themselves in order to prevent damage from spreading doesn't mean that they are self healing, just that they don't propagate failure. They don't regain strength over time after being damaged. Also the fact that they recover 70% of energy used doesn't make them energy efficient, energy efficient would be to find out that the energy used to exert a force over a distance or the power required to get the actuator to push a load at a velocity was nearly equivalent to the electrical input. Plus even if it was really efficient you still need to supply the power in the first place, so there's a high overhead. Even at 100% efficiency for the non-recoverable energy, you'd be supplying 333% of what you got out in physical labor from the device.

Re:Self healing?

But still are human muscles that efficient?

I don't know what the exact numbers are, but when this thing can work all day on a bowl of rice, we'll call it more efficient.

Re:Self healing?

Well calories convert to joules, so say a 1500-calorie (kcal, because food calories are kilocalories for whatever reason) diet converts to (1,500,000 * 4.18) = 6,270,000 joules, which converts to about 2 kilowatt hours...So enough juice to run your microwave for a couple of hours, or a 100watt bulb for 20 hours.

Not too shabby for the amount of energy in a "Double Whopper" meal (with cheese) from Burger King.

Contraction speed

One big question about artificial muscles is about the time required for the muscle to contract. One can make an artificial muscle out of an aligned block copolymer, but it would generally take hours to do anything after the electric potential is applied.

Reversibility, flexibility, bio-compatibility, and tensile strength are also important considerations. When the article is published in Advanced Materials, I'm actually going to read it to find out.

BAD pun, BAD!

From TFA:
Artificial muscles have been around for years but have essentially hamstrung themselves. Some artificial muscles get so big they tear, developing uneven film thickness and random particles that cause muscle failure.

Grooooooan. I guess I'm dating myself, but I remember when the Discovery Channel had something to do with "science". :(

Ah'll be bahck

Wait, so they've invented a muscle that can isolate damage and keep on going? Didn't anyone learn ANYTHING from Terminator 2? T-1000, here we come...

Another expansion

"As the material contracts after an expansion the rearranging of the carbon nanotubes generates a small electric current that can be captured and used to power another expansion or stored in a battery."

The other expansion should not be of the same muscle, of course; alternate between two opposing muscles and you can get a very efficient walking motion going.

(I said "walking," dammit, not "wanking!")

All of the posts complaining that "muscles should contract, not expand" -- hey, it's not that hard to use an expansion to create a useful pulling force. Wrap an elastic sleeve around it that will get shorter as it gets rounder, and mechanically it will work very much like a muscle.

Re:Better than the real thing

How exactly is it better than the real thing?

1. it doesn't heal itself, just mitigates the damage.
2. requires carbon nanotubes which would be very hard to manufacture inside a self contained unit.
3. requires electricity.

Is it awesome? Yes. Is it better than human muscle? No, just different.

Re:

1) Biological muscles don't repair beyond minor damage either. Be it nanotubes or protein-based fibers, either can and will break eventually, usually in tiny amounts at a time. Those ruptures are usually contained, but not repaired. Otherwise injuries woul

Re:Nanotechnology is very interesting.

I really start to wonder what could be around the corner.

Grey goo?

Re:

Nah, Grey Goo is thermodynamically impossible...

To get nano scale replicators you would get an extremly complex molecule/molecule system and at the same time to manipulate it on an atom scale you would need very high energy concentrations.

One thing we know

Re:Nanotechnology is very interesting.

Given that the earth is full of nanomachine colonies trying desperately to consume all available resources and expand indefinitely, I'm pretty sure grey goo won't be all that interesting. If algae and fungi haven't taken over the world after several billion years of trying...

Re:

That sounds like nanotech from Soviet Russia.

Re:

... and they have a self healing artifical penis that expands to up to 100 times its original size.