Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Origami-inspired soft artificial muscles

wyss.harvard.edu

Post reply on HN
Print view View original

21–30 of 60 posts

Re: Origami-inspired soft artificial muscles

#21

Post by SketchySeaBeast »

mlevental wrote: post #13
tomp wrote: post #12

Earlier quoted context omitted.

A steel wirte isn't lifting anything, it's just holding .

i don't understand what this means. you understand that g = 9.81 m/s^2 ... every second? the difference between colloquial lifting and just holding is a matter of applying on the order of just 1% more force.

So if we took away 1% of that 1000x it's own weight it would be able to lift it? It can't. It will never be able to. Only thing I got out of my engineering dynamics class - ropes don't lift. Well, that and jokes about couple moments.

A lift is not a hold. A human can hold a ton of weight against gravity, but that's not them lifting it. See the squat. You can put a huge amount of weight on your back compared to the amount you can actually move. If you put them on an escalator, they could probably even move a distance with it. But that isn't them lifting it that distance.

Re: Origami-inspired soft artificial muscles

#22

Post by arghwhat »

timthelion wrote: post #18
tomp wrote: post #12

Earlier quoted context omitted.

A steel wirte isn't lifting anything, it's just holding .

But a steel wire can be reeled in using a reel. And if we don't include the airpump required for these origami muscles in our "muscle weight" then we don't need to include the winch weight in the case of the reeled wire.

Only counting the steel wire in the winch example is unfair in the other direction. You have to count a small part of the winch (pulley?) for it to be directly comparable.

But this is all incredibly silly, and what we all agree on is that they fail to consider the vacuum pump, valves and reinforced vacuum hoses in order to make their invention seem fancier.

Re: Origami-inspired soft artificial muscles

#23

Post by arghwhat »

SketchySeaBeast wrote: post #21
mlevental wrote: post #13

Earlier quoted context omitted.

i don't understand what this means. you understand that g = 9.81 m/s^2 ... every second? the difference between colloquial lifting and just holding is a matter of applying on the order of just 1% more force.

So if we took away 1% of that 1000x it's own weight it would be able to lift it? It can't. It will never be able to. Only thing I got out of my engineering dynamics class - ropes don't lift. Well, that and jokes about couple moments. A lift is not a hold. A human can hold a ton of weight against gravity, but that's not them lifting it. See the squat. You can put a huge amount of weight on your back compared to the am…

A human can hold several loaded shipping containers stacked upon each other against gravity.

The human will be very flat and leaking all over, but it will be holding the containers.

Re: Origami-inspired soft artificial muscles

#24

Post by ricardobeat »

mlevental wrote: post #13
tomp wrote: post #12

Earlier quoted context omitted.

A steel wirte isn't lifting anything, it's just holding .

i don't understand what this means. you understand that g = 9.81 m/s^2 ... every second? the difference between colloquial lifting and just holding is a matter of applying on the order of just 1% more force.

You mean infinity more force, since at rest (holding) no force is being applied at all.

Re: Origami-inspired soft artificial muscles

#26

Post by ricardobeat »

xchaotic wrote: post #11

The 1000x comparison is silly - in a straight up lifting of things, a simple steel wire can probably lift 100000x times it's weight. The tech has it's uses and they should highlight the flexibility rather than perceived strength...

Maybe the fact that flexible, water-soluble materials can even show up in a comparison to steel is enough of a breakthrough?

Re: Origami-inspired soft artificial muscles

#27

Post by JackFr »

arghwhat wrote: post #22
timthelion wrote: post #18

Earlier quoted context omitted.

But a steel wire can be reeled in using a reel. And if we don't include the airpump required for these origami muscles in our "muscle weight" then we don't need to include the winch weight in the case of the reeled wire.

Only counting the steel wire in the winch example is unfair in the other direction. You have to count a small part of the winch (pulley?) for it to be directly comparable. But this is all incredibly silly, and what we all agree on is that they fail to consider the vacuum pump, valves and reinforced vacuum hoses in order to make their invention seem fancier.

The proper comparison is not with the pulley, the wire or the winch, but rather the structure holding the pulley up.

Re: Origami-inspired soft artificial muscles

#29

Post by DennisP »

keenerd wrote: post #10
fallingfrog wrote: post #4

It looks like this is some kind of pneumatic system, and IMHO if you're calculating strength/weight you would need to take into account the weight of the air compressor, to have a fair comparison with biological muscle. Not to mention the fact that air compressors need to have an energy source, and are quite noisy.

The "big new thing" about this is that it doesn't use compressed air the way traditional air muscles do. It doesn't use compressed air at all. You're probably going to say that vacuum pumps are noisy/heavy next. But this doesn't need traditional high-grade vacuum pumps, very low grade will work. And of course it is entirely moot for industrial machines that stand in place. From what I can tell the trick comes from th…

If you get something working I'd love to see a how-to article.

Re: Origami-inspired soft artificial muscles

#30

Post by NickHoff »

I did my PhD with this group (Rob Wood). When I was there, these kind of actuators, and the robots you would put them in, were just getting started. It's great to see how far they've come.

One of the great benefits of these soft actuators is that you can embed them in soft structures and then get smooth movement in multiple directions. Instead of a rigid robotic arm with a few degrees of freedom, you could build something like a snake or an elephant trunk.

Another exciting area of research (my focus) is that since these actuators are fairly cheap, you could make lots and lots of robots with them. Think thousands. If you had a swarm of 1000 small robots, each of which has minimal power and sensors, what would you do with it? How would they coordinate their behavior? How would they communicate? For that matter, how would you even turn them all on? Swarm algorithms are fun to think about on robots, but are also useful for other problems out in the normal world.

(Don't focus on the "1000x" claim. It's true depending on how you measure, but it's not the exciting part.)

Post reply on HN