Transcript
DR WATT
I'm here at the University of Auckland’s Bioengineering Institute to meet Dr Iain Anderson and learn about biomimetics which is all about designs in nature inspiring designs in the human realm. Iain and his team have developed an artificial muscle and are finding amazing possibilities for its use.
DR ANDERSON
My name is Iain Anderson and I'm a principal investigator with the Auckland Bioengineering Institute and a senior lecturer with the Department of Engineering Science. Biomimetics is the study of life to look for solutions to engineering problems, to look for inspiration from living things.
VOICE-OVER
Iain’s team have been creating machines that have no hard parts in them at all. Instead they work by using a revolutionary, specially designed artificial muscle.
DR ANDERSON
Imagine you’ve got a rubbery material like an acrylic or silicone and you stretch it very, very thin.Then you paint both sides with a flexible electrode, a conducting material that they can stretch. We use carbon grease. You then produce a potential difference across that, a voltage and when that occurs you get charges lining up on both sides. So the pluses and the minuses want to get together, so they try and squash this membrane. The light charges on each side also want to get a part, so it extrudes outward.
VOICE-OVER
What Iain and his team has created are artificial muscles, also known as actuators, that expand and contract when electrically stimulated. At the lab, I met one of the key players in Iain’s team, Ben O’Brien, who shows me how the artificial muscle works.
BEN O’BRIEN
If you look at how much natural muscle is used in life, it's everywhere, right? From elephants to ants, it's all muscle, it's all the same system. It's ubiquitous, it's so useful it's just used everywhere. We hope that with the artificial muscles we can achieve the same widespread use because they have the same overall performance requirements. So what we have here is, we have a membrane that we've stretched out, applied to a triangular frame. You see there's three black zones.
DR WATT
Three black triangles.
BEN O’BRIEN
Yep. Now what these triangles are made of is conducting carbon grease on the membranes. We have a sandwich. We have carbon grease, carbon grease with a bi-electric in the middle, that same stretchy material. So when we turn the motor on, you can see this principle in action. By actuating in sequence we can make that outer orbiter move around in the inner rotor and cause the rotation of the shaft.
VOICE-OVER
Incredibly, it is the super thin artificial muscles that are rotating the central shaft, not the other way around. The potential applications are huge.
BEN O’BRIEN
So we could apply it to industry, to consumer electronics, to health care, to all sorts of fields, yeah. So you can imagine a prosthetic arm or some kind of gauntlet that augments the strength in your body. This has a real advantage over a conventional technology because it's lightweight and strong.
DR ANDERSON
Can we produce a polymer material, electro-active material that can sense its own position as well? And this is what we've been working on.
BEN O’BRIEN
If you close your eyes you can probably touch your nose, that’s because your arms are self-sensing. You know where your hands are, you know what your body is doing, even when you're not looking at it. Now this type of self-sensing we can also recreate in the artificial muscle technology. When the actuator stretches, when the muscle stretches, there is an associated mechanical deformation which changes the electrical properties. So as it stretches the capacitance will change or as the electrodes stretch their resistance will change.
Now, if we measure these parameters, these electrical parameters as we are using the muscle, then we can work out what's the mechanical state of the muscle.
DR WATT
Now Ben is using the principles of biomimetics to take self-sensing to another level.
BEN O’BRIEN
How can we use self-sensing to control groups of actuators working together? So a really neat example of this is something we call the ctenophore or comb jelly. It's a very small jellyfish-like animal and it has thousands of actuators running in rows down its side. In the ctenophore each petal is self-sensing, so each petal can detect the contact of the previous and use that to actuate. So you have one petal, it bends, it hits the next which bends, which hits the next, which hits the next and you get a wave of actuation running down.
DR ANDERSON
Artificial muscles you can not only actuate to produce a motion or create a force, you can also self-sense and you can also generate electricity too.
THOMAS McKAY
This is basically a new type of generator. It's made from artificial muscles, so we can potentially make fully soft generators. This energy that I'm using to pull the artificial muscle and then when I release that, that mechanical energy that I use to stretch it is converted into electrical energy.
VOICE-OVER
To show us how versatile the generator is, we take it outside to show how easily the artificial muscle powered generator can use natural resources like wind to generate power.
THOMAS McKAY
There's no wind today so we’re probably going to have to cheat and get you to do the honours.
DR WATT
I'll be the wind.
THOMAS McKAY
One day we brought it up out here when there was a bit of wind and we had the generator start at 30 volts and it was able to pump itself up to a kilovolt.
DR WATT
So this plants produce a thousand volts?
THOMAS McKAY
Yeah, a thousand volts, just from the wind.
DR WATT
It doesn’t need much movement to actually pump that, does it?
VOICE-OVER
And if that isn't enough, I'm back in the lab with Scott Walbran who is beginning to harness muscle signals directly from the human arm to control the artificial muscles.
SCOTT WALBRAN
My work’s not on artificial limbs. If somebody has an amputation say through here, then they’ve still got all this muscle here. It's not doing anything but if they try and control their hand that’s been cut off, that muscle will still activate.
VOICE-OVER
Scott’s wired me up to see if I can use my own arm muscle to control the movement of the artificial muscle.
DR WATT
By clenching my fist I get this muscle to work this artificial muscle. Incredible! It's awesome! I feel like the Bionic Man.
VOICE-OVER
The breakthrough of these revolutionary artificial muscles could change the face of engineering in the future and lead to whole new frontiers in soft computing.
DR ANDERSON
Get rid of all that hard stuff and you can maybe have mechanical devices that will be almost animal-like in their performance.
BEN O’BRIEN
Creating an actuator that can move a lot that is also strong, that is also lightweight, that is also quiet, that is also efficient, this is the Holy Grail of robotics.
DR WATT
Machines and technology continue to play an increasing role in our lives. Who knows what the next 50 years will bring? That’s it for this episode of Ever Wondered? If you enjoyed the science and you want to find out more, visit the Ever Wondered? website. Join me again next time.
