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Wearable Muscles

ethz.ch

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Re: Wearable Muscles

#21

Post by leobg »

pvaldes wrote: post #15
leobg wrote: post #8

My immediate thought was: We could use those to power wings and fly! You see, I spent the last weeks reading up on Otto Lilienthal. And while we might think that we have already "cracked" flying, we actually haven't. Humans still cannot fly. We can only board. What we do not have achieved is the sense of "flying like a bird", which Lilienthal was after. The idea that you control your movements through the air directl…

The obvious step would be not try to fly, would be improving hang gliders to be safer, catch better the wind currents or avoid obstacles proactively and have more autonomy. If the device suddenly fails, you still are in a hand glider. Also engineering a motor that would flap like a colibri for hours without failing will be really hard and uncomfortable by the generated heat burning your back, but a motor that would f…

Flapping like a colibri would, I suppose, also be rather loud and create noise. What fascinated Lilienthal was the way large birds like storks fly: They do flap their wings to take off, and also when there are no thermals. But most of the time, they glide or use thermals to gain altitude.

I do have to say, whenever I see a stork above, or even just a red kite or pelican, I feel envious. Our drones and planes just seem crude in comparison.

To be clear: I'm not talking about flight as a means to get from A to B as quickly as possible. That's the domain of the jet engine, and no bird can match it. I'm talking about flying as a thing you do for the enjoyment of it, as a thing of beauty and wonder. In short, that which inspired humans to dream about flying machines in the first place.

Re: Wearable Muscles

#22

Post by Vecr »

rexf wrote: post #7

Looking forward to the future where wearable exoskeletons/exomuscle provide endurance, possible reduced injury, strength, etc. If the market is going to sell us AR glasses, a wearable ecosystem could provide battery power and shift weight around (away from your head). This system would provide power for any number of accessories (phone, watch, earbuds, etc).

etc may include: helmet mounted night vision optics, EW/ECM/jamming equipment, long range radios, gun optic sights, power to re-charge suicide drones if suitable targets fail to appear.

Re: Wearable Muscles

#23

Post by scotty79 »

If you could actuate hard, padded shell in this manner it could be a true exoskeleton. You'd just have to figure out how to design joints on the shell to have exact same range of motion as the limb inside it.

Re: Wearable Muscles

#24

Post by leobg »

10000truths wrote: post #11
leobg wrote: post #8

My immediate thought was: We could use those to power wings and fly! You see, I spent the last weeks reading up on Otto Lilienthal. And while we might think that we have already "cracked" flying, we actually haven't. Humans still cannot fly. We can only board. What we do not have achieved is the sense of "flying like a bird", which Lilienthal was after. The idea that you control your movements through the air directl…

The problem of “flying” in the sense you describe is fundamentally limited by the square cube law. Even birds, whose anatomies are literally evolved for flight, will have a tough time staying in the air if they are scaled up to have a similar mass to us humans.

Lilienthal himself didn't, as far as I know, address your precise argument (the water strider bug scaling issue). But your comment reminded me of this snippet from his 1889 book:

  The bodies of flying creatures are not so materially lighter than those of other animals, as to justify us in considering this difference in weight an essential condition of flight. It is often asserted that the hollow bones of birds facilitate their flight, especially since the hollows are filled with heated air, but it does not require much thought to come to the conclusion that this diminution of weight is barely worth mentioning. Also, we have not been able as yet to prove that the muscle and bone substance, as well as other parts of the bird's body, are specifically light. [...] After a bird is plucked, no one will assert that it is propor­ tionally lighter than other animals, and our housewives are certainly not under the impression that a pound of bird's flesh, even with the hollow bone included, is more bulky than an equal weight of flesh from another animal. [0]
[0] Otto Lilienthal, Birdflight As the Basis of Aviation, pages 2-3, https://s3-eu-west-1.amazonaws.com/bga-sg-archive/Books/BIRD...

Re: Wearable Muscles

#25

Post by poulpy123 »

leobg wrote: post #8

My immediate thought was: We could use those to power wings and fly! You see, I spent the last weeks reading up on Otto Lilienthal. And while we might think that we have already "cracked" flying, we actually haven't. Humans still cannot fly. We can only board. What we do not have achieved is the sense of "flying like a bird", which Lilienthal was after. The idea that you control your movements through the air directl…

We can't fly by flapping wings like birds but we can certainly glide like raptor birds by para- or hand-gliding

Re: Wearable Muscles

#26

Post by thejohnconway »

10000truths wrote: post #11
leobg wrote: post #8

My immediate thought was: We could use those to power wings and fly! You see, I spent the last weeks reading up on Otto Lilienthal. And while we might think that we have already "cracked" flying, we actually haven't. Humans still cannot fly. We can only board. What we do not have achieved is the sense of "flying like a bird", which Lilienthal was after. The idea that you control your movements through the air directl…

The problem of “flying” in the sense you describe is fundamentally limited by the square cube law. Even birds, whose anatomies are literally evolved for flight, will have a tough time staying in the air if they are scaled up to have a similar mass to us humans.

Some birds and several pterosaurs got to human masses and more. Staying in the air is not much of a problem, but launching is. Pterosaurs have a massive advantage here in that they launched with all four limbs, meaning they could use their flight muscles to launch. Birds can't do this and have to rely on their legs (which are useless in the air).

Re: Wearable Muscles

#27

Post by leobg »

JetAlone wrote: post #20
leobg wrote: post #8

My immediate thought was: We could use those to power wings and fly! You see, I spent the last weeks reading up on Otto Lilienthal. And while we might think that we have already "cracked" flying, we actually haven't. Humans still cannot fly. We can only board. What we do not have achieved is the sense of "flying like a bird", which Lilienthal was after. The idea that you control your movements through the air directl…

There have been massive struggles taken on by individuals and small teams to create ornithopters that can carry people. A solely human powered ornithopter was able to stay airborne for 19 seconds - using a mediatory lever to transfer push/pull leg power into wing motions. https://www.youtube.com/watch?v=DM9GJ3JOJv0 Then there is, of course, the story of the skycycle, which is rotational. https://www.nytimes.com/1979/…

Cool video. I wish they would have used an electric car for the camera man. As it is, the car's engine noise tremendously distracts from the grace of the ornithopter.

To fly like a bird, you probably need more motion control over the wings than just "up and down". I believe birds can angle their wings, they can curve them, and they can sense differences in air speed and air pressure across the wing's surface. That's why it seems to me that any form of artificial muscle would be a huge step.

Re: Wearable Muscles

#28

Post by leobg »

poulpy123 wrote: post #25
leobg wrote: post #8

My immediate thought was: We could use those to power wings and fly! You see, I spent the last weeks reading up on Otto Lilienthal. And while we might think that we have already "cracked" flying, we actually haven't. Humans still cannot fly. We can only board. What we do not have achieved is the sense of "flying like a bird", which Lilienthal was after. The idea that you control your movements through the air directl…

We can't fly by flapping wings like birds but we can certainly glide like raptor birds by para- or hand-gliding

Very true. But imagine you could strap on such the wings of a glider along with artificial muscles that map to, say, your arms and hands. You could take off and fly and land like a bird. No need for a cliff or runway or anything. You'd also be as silent as an eagle circling above the tree tops.

Re: Wearable Muscles

#29

Post by thejohnconway »

centixel wrote: post #14
10000truths wrote: post #11

Earlier quoted context omitted.

The problem of “flying” in the sense you describe is fundamentally limited by the square cube law. Even birds, whose anatomies are literally evolved for flight, will have a tough time staying in the air if they are scaled up to have a similar mass to us humans.

Wikipedia says a Pteranodon[0] might have weighed up to 200kg. I wonder if the different mix of gases in the atmosphere during the Cretaceous period made any difference to how much weight could be supported while flying. 0: https://en.m.wikipedia.org/wiki/Pteranodon

Annoyingly, the wikipedia article was wrong, and mistakenly gave the figures for Quetzalcoatlus in that paragraph. Pteranodon weighed more like 20-30kg (I've edited it).

The constraint on the size of flying animals is launch, not flight. Pterosaurs could get bigger than birds because they used quadrupedal launch, meaning they could use their flight muscles during the initial leap.

Re: Wearable Muscles

#30

Post by asd4 »

It's a single axis version of a system my group at NASA developed:

https://roundupreads.jsc.nasa.gov/pages.ashx/787/New%20weara...

The internal application was to improve mobility in space suits. We had a partnership with some medical researchers looking to help patients with otherwise limited mobility.

Shoulders are difficult. The human body has a lot of amazing degrees of freedom. One of the biggest challenges was efficient and effective transfer of the assist forces to the body.

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