Robert Full on engineering and evolution

Robert Full on engineering and evolution
http://www.ted.com/talks/robert_full_on_engineering_and_evolution.html

Welcome. If I could have the first slide please? Contrary to
calculations made by some engineers, bees can fly, dolphins can swim,
and geckos can even climb up the smoothest surfaces. Now what I want
to do, in the short time I have, is to try to allow each of you to
experience, sort of, the thrill of revealing natures design. I get to
do this all the time, and it's just incredible. I want to try to share
just a little bit of that with you in this presentation. The challenge
of looking at nature's designs -- and I'll tell you the way that we
perceive it, and the way we've used it. The challenge of course, is to
answer this question: What permits this extraordinary performance of
animals that allows them basically to go anywhere? And if we could
figure that out how can we implement those designs?

Well, many biologists will tell engineers and others, organisms have
millions of years to get it right, they're spectacular, they can do
everything wonderfully well. So the answer is biomimicry -- just copy
nature directly. We know from working on animals that the truth is
it's exactly what you don't want to do. Because evolution works on the
just-good-enough principle, not on a perfecting principle. And the
constraints in building any organism when you look at it are really
severe. Natural technologies have incredible constraints. Think about
it. If you were an engineer and I told you that you had to build an
automobile but it had to start off to be this big, then it had to grow
to be full size and had to work every step along the way. Think about
the fact that if you build an automobile I'll tell you that you also
inside it have to put a factory that allows you to make another
automobile.

(Laughter)

And you can absolutely never, absolutely never, because of history and
the inherited plan, start with a clean slate. So organisms have this
important history. Really evolution works more like a tinkerer than an
engineer. And this is really important when you begin to look at
animals. Instead we believe you need to be inspired by biology. You
need to discover the general principles of nature, and then use these
analogies when they're advantageous. This is a real challenge to do
this because animals, when you start to really look inside them, how
they work, appear hopelessly complex. There's no detailed history of
the design plans, you can't go look it up anywhere. They have way too
many motions for their joints, too many muscles, even the simplest
animal we think of, something like an insect, and they have more
neurons and connections than you can imagine.

How can you make sense of this? Well, we believed -- and we
hypothesized -- that one way animals could work simply, is if the
control of their movements tended to be built into their bodies
themselves. What we discovered was that two, four, six and eight
legged animals all produce the same forces on the ground when they
move. They all work like this kangaroo, they bounce. And they can be
modeled by a spring mass system that we call the spring mass system
because we're bio mechanists, it's actually a pogo stick. They all
produce the pattern of a pogo stick. How is that true? Well, a human,
one of your legs, works like two legs of a trotting dog, or works like
three legs together as one of a trotting insect, or four legs as one
as a trotting crab. And then they alternate in their propulsion, but
the patterns are all the same. Almost every organism we've looked at
this way -- you'll see next week -- I'll give you a hint, there'll be
an article coming out that says that really big things like T. Rex
probably couldn't do this, but you'll see that next week.

Now what's interesting is the animals then we said bounce along the
vertical plane this way, and in our collaborations with Pixar in "A
Bug's Life," we discussed the bipedal nature of the characters of the
ants. And we told them of course they move in another plane as well,
and they asked us this question. They say, "Why model just in the
sagittal plane or the vertical plane, when you're telling us these
animals are moving in the horizontal plane?" This is a good question.
Nobody in biology ever modeled it this way. We took their advice and
we modeled the animals moving in the horizontal plane as well. We took
their three legs, we collapsed them down as one, we got some of the
best mathematicians in the world from Princeton to work on this
problem. And we were able to create a model where animals are not only
bouncing up and down, but they're also bouncing side to side at the
same time. And many organisms fit this kind of pattern. Now why is
this important to have this model? Because it's very interesting. When
you take this model and you perturb it, you give it a push, as it
bumps into something, it self-stabilizes, with no brain, or no
reflexes, just by the structure alone. It's a beautiful model. Let's
look at the mathematics.

(Laughter)

That's enough.

(Laughter)

The animals, when you look at them running, appear to be self
stabilizing like this, using basically springy legs. That is, the legs
can do computations on their own, the control algorithms in a sense
are embedded in the form of the animal itself. Why haven't we been
more inspired by nature and these kinds of discoveries? Well, I would
argue that human technologies are really different from natural
technologies, at least they have been so far. Think about the typical
kind of robot that you see. Human technologies have tended to be
large, flat, with right angles, stiff, made of metal. They have
rolling devices and axles. There are very few motors, very few
sensors. Whereas nature tends to be small, and curved, and it bends
and twists and has legs instead and appendages, and has many muscles
and many, many sensors. So it's a very different design. However,
what's changing, what's really exciting -- and I'll show you some of
that next -- is that as human technology takes on more of the
characteristics of nature, then nature really can become a much more
useful teacher.

And here's one example that's really exciting. This is a collaboration
we have with Stanford. And they developed this new technique called
Shape Deposition Manufacturing. It's a technique where they can mix
materials together and mold any shape that they like, and put in the
material properties. They can embed sensors and actuators right in the
form itself. For example, here's a leg -- the clear part is stiff, the
white part is compliant, and you don't need any axles there or
anything. It just bends by itself beautifully. So you can put those
properties in. It inspired them to show off this design by producing a
little robot they named Sprawl. Our work has also inspired another
robot, a biologically-inspired bouncing robot, from the University of
Michigan and McGill named RHex, for robot hexapod, and this one's
autonomous. Let's go to the video and let me show you some of these
animals moving. And then some of the simple robots that have been
inspired by our discoveries. Here's what some of you did this morning,
although you did it outside not on a treadmill. Here's what we do.

(Laughter)

This is a death's head cockroach -- this is an American cockroach you
think you don't have in your kitchen. This is an eight-legged
scorpion, six-legged ant, forty-four-legged centipede. Now I said all
these animals are sort of working like pogo sticks -- they're bouncing
along as they move and you can see that in this ghost crab from the
beaches of Panama and North Carolina. It goes up to four meters per
second when it runs. It actually leaps into the air and has aerial
phases when it does it, like a horse, and you'll see it's bouncing
here. What we discovered is whether you look at the leg of a human
like Richard, or a cockroach, or a crab, or a kangaroo, the relative
leg stiffness of that spring is the same for everything we've seen so
far. Now what good are springy legs then, what can they do? Well, we
wanted to see if they allowed the animals to have greater stability
and maneuverability. So we built a terrain that had obstacles three
times the hip height of the animals that we're looking at, and we were
certain they couldn't do this. And here's what they did. The animal
ran over it and it didn't even slow down. It didn't decrease its
preferred speed at all. We couldn't believe that it could do this. It
said to us that if you could build a robot with very simple springy
legs, you could make it as maneuverable as any that's ever been built.

Here's the first example of that, this is the Stanford Shape
Deposition Manufactured robot named Sprawl. It has six legs -- there
are the tuned springy legs. It moves in a gait that an insect uses and
here it is going on the treadmill. Now what's important about this
robot, compared to other robots, is that it can't see anything, it
can't feel anything, it doesn't have a brain, yet it can maneuver over
these obstacles without any difficulty whatsoever. It's this technique
of building the properties into the form. This is a graduate student,
this is what he's doing to his thesis project, very robust if a
graduate student does that to his thesis project.

(Laughter)

This is from McGill and University of Michigan, this is the RHex,
making its first outing in a demo.

(Laughter)

Same principle. It only has six moving parts. Six motors, but it has
springy, tuned legs. It moves in the gait of the insect it has the
middle leg moving in synchrony with the front and the hind leg on the
other side. Sort of an alternating tripod, and they can negotiate
obstacles just like the animal.

(Laughter)

Oh my God.

(Applause)

It'll go on different surfaces, here's sand, although we haven't
perfected the feet yet, but I'll talk about that later. Here's RHex
entering the woods.

(Laughter)

Again this robot can't see anything, it can't feel anything, it has no
brain. It's just working with a tuned mechanical system, with very
simple parts. But inspired from the fundamental dynamics of the
animal. Ah, I love him Bob. Here's it going down a pathway. I
presented this to the jet propulsion lab at NASA, and they said that
they had no ability to go down craters to look for ice, and life
ultimately, on Mars. And he said -- especially with legged-robots
because they're way too complicated. Nothing can do that. And I talk
next. I showed them this video with the simple design of RHex here,
and just to convince them we should go to Mars in 2011, I tinted the
video orange just to give them the sense of being on Mars.

(Laughter)

(Applause)

Another reason why animals have extraordinary performance and can go
anywhere, is because they have an effective interaction with the
environment. The animal I'm going to show you that we studied to look
at this is the gecko. We have one here and notice its position. It's
holding on. Now I'm going to challenge you. I'm going show you a
video. One of the animals is going to be running on the level, and the
other one's going to be running up a wall. Which one's which? They're
going at a meter a second. How many think the one on the left is
running up the wall?

(Applause)

Okay. The point is it's really hard to tell, isn't it? It's
incredible, we looked at students do this and they couldn't tell. They
can run up a wall at a meter a second, 15 steps a second and they look
like they're running on the level. How do they do this? It's just
phenomenal. The one on the right was going up the hill. How do they do
this -- they have bizarre toes -- they have toes that uncurl like
party favors when you blow them out, and then peel off the surface
like tape. Like if we had a piece of tape now we'd peel it this way.
They do this with their toes. It's bizarre. This peeling inspired
iRobot that we work with, to build Mecho-Geckos. Here's a legged
version and a tractor version, or a bulldozer version. Let's see some
of the geckos move with some video, and then I'll show you a little
bit of a clip of the robots. Here's the gecko running up a vertical
surface, there it goes, in real time, there it goes again. Obviously
we have to slow this down a little bit.

You can't use regular cameras. You have to take 1,000 pictures per
second to see this. And here's some video at 1,000 frames per second.
Now I want you to look at the animal's back. Do you see how much it's
bending like that? We can't figure that out -- that's an unsolved
mystery. We don't know how it works. If you have a son or a daughter
that wants to come to Berkeley, come to my lab and we'll figure this
out. Okay, send them to Berkeley because that's the next thing I want
to do. Here's the gecko mill.

(Laughter)

It's a see through treadmill with a see through treadmill belt, so we
can watch the animals feet, and video tape them through the treadmill
belt, to see how they move. Here's the animal that we have here,
running on a vertical surface, pick a foot and try to watch a toe, and
see if you can see what the animal's doing. See it uncurl and then
peel these toes. It can do this in 14 milliseconds. It's unbelievable.
Here are the robots that they inspire, the Mecho-Geckos from iRobot.
First we'll see the animals toes peeling -- look at that. And here's
the peeling action of the Mecho-Gecko it uses a pressure-sensitive
adhesive to do it. Peeling in the animal, peeling in the Mecho-Gecko,
that allows them climb autonomously can go on the flat surface
transition to a wall, and then go on to a ceiling. There's the
bulldozer version. Now it doesn't use pressure-sensitive glue. The
animal does not use that. But that's what we're limited to at the
moment.

What does the animal do? The animal has weird toes, and if you look at
the toes they have these little leaves there, and if you blow them up
and zoom in you'll see that's there's little striations in these
leaves. And if you zoom in 270 times, you'll see it looks like a rug.
And if you blow that up, and zoom in 900 times, you see there are
hairs there, tiny hairs, and if you look carefully those tiny hairs
have striations. And if you zoom in on those 30,000 times, you'll see
each hair has split ends. And if you blow those up they have these
little structures on the end. The smallest branch of the hairs looks
like a spatula and an animal like that has 1 billion of these
nano-size split ends to get very close to the surface. In fact there's
the diameter of your hair, a gecko has 2 million of these and each
hair has 100 to 1,000 split ends. Think of the contact of that that's
possible.

We were fortunate to work with another group at Stanford that built us
a special manned sensor that we were able to measure the force of an
individual hair. Here's an individual hair with a little split end
there, when we measured the forces they were enormous, they were so
large that a patch of hairs about this size, the gecko's foot could
support the weight of a small child -- about 40 pounds easily. Now how
do they do it? We've recently discovered this. Do they do it by
friction? No, force is too low. Do they do it by electrostatics? No,
you can change the charge, they still hold on. Do they do it by
interlocking? That's kind of a like a Velcro like thing. No, you can
put them on molecular smooth surfaces -- they don't do it. How about
suction? They stick on in a vacuum. How about wet adhesion? Or
capillary adhesion? They don't have any glue and they even stick under
water just fine. If you put their foot under water they grab on. How
do they do it then? Believe it or not they grab on by intermolecular
forces, by van der Waals forces.

You know you probably had this a long time ago in chemistry where you
had these two atoms, they're close together, and the electrons are
moving around. That tiny force is sufficient to allow them to do that
because it's added up so many times with these small structures. What
we're doing is we're taking that inspiration of the hairs, and with
another colleague at Berkeley, we're manufacturing them. And just
recently we've made a breakthrough where we now believe we're going to
be able to create the first synthetic, self cleaning, dry adhesive.
Many companies are interested in this.

(Laughter)

We also presented to Nike even.

(Laughter)

(Applause)

We'll see where this goes. We were so excited about this that we
realized that that small-size scale, and where everything gets sticky,
and gravity doesn't matter anymore, we needed to look at ants and
their feet, because one of my other colleagues at Berkeley, has built
a six-millimeter silicone robot with legs. But it gets stuck. It
doesn't move very well. But the ants do and we'll figure out why, so
that ultimately we'll make this move. And imagine, you're going to be
able to have swarms of these six-millimeter robots available to run
around. Where's this going? I think you can see it already.

Clearly the internet is already having eyes and ears, you have web
cams and so forth. But it's going to also have legs and hands. You're
going to be able to do programmable work through these kinds of
robots, so that you can run, fly and swim anywhere. We saw David
Kelly's at the beginning of that with his fish. So in conclusion, I
think the message is clear. If you need a message, if nature's not
enough, if you care about search and rescue, or mine clearance, or
medicine, or the various things we're working on, we must preserve
nature's designs, otherwise these secrets will be lost forever. Thank
you.