[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.)

[gene-h]

I believe soft actuators have hidden costs. While the actuators themselves may be cheap, the valving and pumps may not be.

[NickHoff]

Certainly. For what I said about the swarms to make sense, each robot must have a self-contained power source or be externally powered in a wholesale manner (generally by absorbing energy from the environment). For single (or few) robots though, you usually want the neat actuation mechanics and you're happy to pay the cost of the actuators and associated support hardware. The supporting hardware is always getting lighter and smaller though.

[YeGoblynQueenne]

Well, since you've worked with those kinds of actuators I hope you can clarify something I wasn't sure about in the article: can the same muscle perform different actions? For example, could you have a muscle that can bend to the left, then to the right of some central line?

I'm asking because the statement [edit: in the article] that "designing how the skeleton folds defines how the whole structure moves" makes me think that perhaps the range of motions each muscle can perform is limited by construction.

Ahem. That's not to downplay the obvious usefuleness of such a device. As far as I'm concerned t's the first time in ages I find a robotics piece of news cool.

[NickHoff]

In general no, single actuators move in one dimension and then only in one direction. In humans we have muscle pairs, one contracts to open the joint and the other contracts to close the joint. Of course you can do the same thing with artificial actuators, but you're right, the really interesting stuff happens when you have lots of "actuators" (like a sheet that has a hundred individually inflatable cells) or the material that the actuators are embedded in folds in an interesting way. The properties of the skeleton have as much to do with the dynamics of the robot as the actuators do.

[YeGoblynQueenne]

Thanks for answering. I looked at the video again and I can see that a couple of setups use multiple muscles- that's what you're talking about I think. I'm guessing that it's going to be a lot easier to wrap a hundred individual muscles of this kind around an artificial skeleton than it is with "hard" ones.

I wonder also what all this means for more, let's say, traditional robots- like the ones we often see from Boston Dynamics. I guess it's still early to say but if I understand this correctly, people can now make cheap, light robots. Where does that leave heavy, expensive ones?

It's not a rhetorical question- Ferrari and McLaren didn't hang up their spanners just because Toyota and Datsun sell lots of cheap cars...

[mark-r]

It does seem from the description that only one motion is possible for one of these muscles. Full motion would require combining multiple muscles with complementary motion, similar to the way the body works.

The speed seems much slower than that of an actual muscle. Is this inherent in the technology or just a limitation of the current prototypes?

[creep]

I can imagine this being modified for spring-like muscles, with a more elastic material. Other than that, you can just suck the air out faster (which has a limit) would work better with shorter muscle "segments".

[QAPereo]

If you had a swarm of 1000 small robots, each of which has minimal power and sensors, what would you do with it?

Do you need to ask? Look around, although many uses positive and negative would be found the primary two would be: espionage and “warfare” in that order.

[tikwidd]

Do you know of any way to "charge" the vacuum that drives these over a long period (from differences in air pressure?) so that they could passively build up energy and release in short bursts?