Artificial muscles robotic arm with full range of motion [video]

If they worked a little on making those things quieter, they'd be like 10X more creepy by virtue of being 10X closer to crossing the uncanny valley. When you make a robotic arm that is so closely modeled after a human arm, isn't that one of the goals?

Wow that is an amazing demo, mainly because of how clean and contained the forearm is. I am not sure what the external hydraulic source is like (size, efficiency, etc) and of course a mechanical design like this isn't self-healing the way a biological arm is, but still pretty cool to see.

Yah. But it also bleed out or really care if it losses a limb. Just needs another buddie to attach a new one.

A few comparisons:

> forearm with hand [weighs] only 1 kg

That is slightly below a human forearm with a hand.

> This artificial muscles robotic arm is operated by water and consumes 200W at peak

The ideal consumption necessary to raise this 7 kg dumbbell by 1 meter in 1 second is 7 watts.

Human muscle is about 20% efficient, so it probably consumes about 35 watts. Almost a tenth the power.

A human arm can also achieve about double the maximum output of that robotic arm: for instance this crank[0] offers 400 W max, with a more typical 50 W sustained output.

> achieve human immortallity [sic] by transplanting the brain into the machine

That feels like a stretch, given the complex needs of a brain (not just in glucose fed through veins, but also immunity protection and so much more). Brain transplant into an organic body seems easier, and even that does not address the fact that brain cells themselves age.

[0]: https://www.electricpedals.com/hand-crank-generator

This guy is a great engineer, I’ve been following his stuff for a while now. But there are unfortunately several fundamental limits which mean this type of system will likely never reach human level performance in a real world system.

I work in robotics, specifically compliant and modular actuators, similar to the ones in the video.

As I see it, (and many others in the field) One of the biggest issues in robotics is a lack of good artificial muscles. The need for them is that in a robot which can work with people you want it to have both high enough force output and power density to actually move things, but you also want the robots arms to be back drivable; you want to be able to move its arms by an outside force. For welding robots you want the opposite, zero backdriving and zero backlash.

To get back-drivability, good torque and reasonable power density, you generally can’t use spinning electric motors. You need to hear them too much. This is why Boston dynamics use hydraulics. It’s also why Boston dynamics is unlikely to ever sell you an Atlas in its current form because those custom hydraulic actuators make the system so unreliable and expensive, even a mining or gas company would struggle to justify it.

The short and long of it is this: if you want a robot that can do the things humans can do, like play soccer and rock climbing and knitting, then you need muscles like humans have.

So you need artificial muscles. There are a lot of different ways of making them. [1] the issue is no published technology is able to give you want you need to make a good analogue of human muscles.

The muscles in the video are (correct me if I’m wrong) soft fluidic actuators. These actually have pretty good potential, especially compared to things like piezoelectric actuators. But when taking into account how you would actually put these in a real world robot, problems arise.

But the main downside is you need lots of pumps and tubing to make it work, and it has limited maximum stress and relatively low actuation bandwidth. In a nut shell, to make these strong enough to do much useful work, you need them to be really big, and that means they can’t move very fast. There is a reason you don’t see any commercially available robots with this kind of actuator.

I really hope this creator can make his system do what he has set out to achieve. And perhaps he will be the one to figure out a new kind of actuator which does tick all the right boxes.

Conflict of interest: The startup I work at is developing a commercial product using a new kind of artificial muscle. So my views may be coloured by that.

[1] See this paper for a good breakdown of artificial muscles: https://sci-hub.se/downloads/2019-10-12/7c/zhang2019.pdf?ran...