They are a living swimming self-powered robot
that is less than a millimeter across.
So some people were really afraid of the technology.
It's something new they've never seen before.
Other people were really excited about the potential to push discovery
in both computer science and in biological sciences.
I've heard this idea that this kind of work is so-called playing God.
But I get phone calls every week from people
with the most heartbreaking conditions.
And all of them are waiting for new science
to try to improve life for all.
Are they robots or are they not?
Are they organisms? Are they not?
They are forcing us to blur previous distinctions,
which might allow us to see the world
in a new way.
The xenobots are designed by computers,
and we built them in the real world out of real
living tissues.
We call these "xenobots" for two reasons;
the frog that these cells are made of is called Xenopus laevis.
So that's where the xeno comes from.
Bot means robot because this is a profoundly interesting
biorobotics platform.
There is no remote
control hidden off to the side.
They're made from genetically unmodified cells,
but they've been created by A.I.
And they are definitely not a normal animal.
Only in the past few decades have insights from biology
fed into engineering and vice versa.
A lot of the first applications in the field were very focused on medicine
so thinking about how do we put cells together
to make replacement tissues or organs for medical applications.
But then they also started getting more excited about, well,
maybe we could build things that don't already exist in nature.
And if you take that to the extreme, that is where this biobot project
really came from.
Can you put cells together and build
a synthetic organism from the ground up?
It's actually a new kind of engineering,
which is a collaboration with your material.
When you work with cells and tissues,
you are working with a material that actually has its own agenda.
It has preferences, it has the ability to solve certain kinds of problems.
It doesn't behave the way that wood and metal
might behave where you know exactly what it's going to do.
This brand new idea of building robots
out of living cells seemed really, really difficult.
Our collaborative
research on this project began around 2017.
What the original plan was, was to get computer
scientists and developmental biologists in the same room
under some funding to work together to try to create A.I.
systems and robots that could work out in the real world,
drawing inspiration from biology, which is so adaptive.
But there was nothing about building
robots out of frog cells.
At the time, we were designing virtual creatures
inside of a computer, soft robots that you could cut off
part of its body and it would deform
to recover its functionality.
As we were doing the study, I'd been watching Dr.
Bongard's and Dr.
Kriegman's simulated models.
But the things that they were building in their simulator
looked really similar to things that we could build with frog cells.
So could we build some sort of facsimile biologically?
I wasn't really sure that that was going to be possible.
I might have brushed Doug off and said, "You know,
sure, go try to do that." When Doug first said that he could make
the various shapes that Josh and Sam created, I had no doubt that he could,
because these cells are really motivated
to work together to build something.
They can adjust to all kinds of changes, all kinds of experimental perturbations
to really get their job done.
For example, he created tadpoles
with eyes on their tails and showed that these cells could see.
So that got me interested in this idea of modularity in your pieces of an animal
that can be moved around like Lego and reattached somewhere else.
And if you take that to the extreme, it's
taking the pieces of developing frog
and building something entirely new from the ground up.
And so when I said that this is possible,
I think that they probably believed it was a joke.
And really that's to a scientist throwing down the gauntlet.
So now I must build it, right?
I'll show them that this technology exists.
Unbeknownst to us, Doug spent
the week very carefully putting together some frog tissue
under the microscope to try and build
one of Sam's creations.
Honestly, I wasn't really sure what I was looking at at first,
if this was just kind of a party trick.
But it was completely unexpected.
And we started to realize that
if we can actually copy the movement
that we saw in the simulation,
then we would be able to design these systems
in the simulation and build them in reality.
And that was very exciting.
Doug is fantastically
talented, but it still takes him about 4 hours
to create one millimeter sized xenobot.
Turns out that an A.I.
can make billions and billions
of candidate designs for hours or days or
weeks on a supercomputer, which is much more efficient
at finding interesting, useful designs that Doug can build.
This kind of design process
takes inspiration from Darwinian evolution
and natural selection and applies it to robots.
What happens is that we supply the computer with these building blocks.
We have one block and it kind of contracts and expands.
This is simulating heart tissue.
And we have another block that is just passive frog cells.
And initially, the computer randomly assembles the blocks
into a bunch of random designs,
and then we supply a behavioral goal.
What should the system do?
At the very first experiment, what we started with was
we want a millimeter-sized machine
that walks along the bottom of a petri dish.
Basically, the supercomputer
deletes the poorly performing creatures,
makes randomly modified copies of the survivors.
And over many generations, this population
of robot designs
gets better at the objective.
You can evolve their shapes, their material, properties,
their control systems.
And this allows us to go through billions of years
of evolution all at once.
But eventually we get back the handful of champions
to see which, if any of them can be turned into reality.
Every week, Sam provides
me with a model of shapes that perform a particular function,
basically a blueprint, almost like if you're assembling furniture or Lego.
So it all starts with a developing
frog embryo that's 24 hours old.
And at this stage, all of the cells are still stem cells.
STEM cells can become anything like
skin or an internal organ.
But we have an atlas that maps these different regions of the embryo.
And so over the course of the next 24 hours,
I very carefully, with microsurgery
tools, harvest different parts of the embryo
and collect them into different piles.
So these cells are naturally sticky.
So if you take loose stem cells and put them together into a pile,
they're adhere into a sphere over time.
And so if you're very tricky and very careful and have very good
fine motor skills, you can now take the sphere
that has all sorts of different tissues inside
and sculpt it to reveal some form,
the way that you would sculpt the away a piece of wood.
I think that there's this misconception
that all of biology is this hard, rigorous discipline
and that there's no creativity or beauty or artistry.
It's incredibly amazing and relaxing to look down the eyepiece
and to build something that no one has ever seen before.
But it's also important to the science to generate shapes
that wouldn't be produced naturally.
And it took us another year or so to be able to defend that.
There was a match between the evolutionary
algorithms, dreams or designs
and what we were getting in reality.
The moment we had that early data, I got up from my desk,
my hands were shaking to just absorb
the implications that this was possible.
When I saw
these creatures for the first time, I was I was absolutely blown away.
They have spontaneous motion.
They gather together and have really complex interactions in a group.
They can heal themselves.
So if you cut one almost in half, it will zip back up.
And that's just that's just the beginning.
So the first designs that I built in the lab were cardiac driven.
So these are heart cells through contractions these walked.
But eventually we switched to cilia.
So these are small hair like structures on the outside of the body.
It produces movement that is much faster.
And using cilia, it allows the robot to swim
instead of crawl
And Doug, trying to visualize
the movement of the xenobots that he built, placed
dye particles on the bottom of the dish.
And what we noticed was that
they will tend to create piles, which led us to the idea
that they could be designed to be better and better bulldozers.
And that's an interesting behavior that can be leveraged
for all sorts of interesting mechanical work.
But Mike Levin had the idea of what would happen
if these particles were replaced with stem cells.
So this is the material that the biobots they themselves are made of.
And if the xenobots made big enough
piles of cells, those piles could themselves
form into little children bulldozers.
So unlike every other living system that we know of,
the xeno bots do not reproduce through growth.
We give them additional building materials in like a robot in a stockroom.
They stick together as materials to build a copy of themselves.
So just by starting the first generation as a c-shape,
the spheres that were created were much larger, which created larger
offspring and allowed us to get the five to six generations.
We don't want uncontrolled self-replication.
That's a dangerous thing.
But for a roboticist, the realization that xenobots could
self-replicate is a huge deal
because roboticists have been trying to create
self-replicating machines for a very long time.
Seems that when you do this with living
materials, it's suddenly much easier
The thing that caught me by far
the most guard in this entire project was the public response.
A lot of the global media saw this as a huge breakthrough,
which was followed by a massive outpouring of opinion on social media.
Fear, paranoia, excitement, it just went wild.
We were getting tweets and Instagram
posts and news stories from countries all across the world.
The xenobots might escape from the lab
and replicate out of control.
Now a lot of people, they will say, "Well, this isn't natural or so-called things
that shouldn't be created." But we really have to understand
the ethics of this, much like any other biological experiment
is really, really critical to think about
before you do anything.
When I first read articles about xenobots,
my response as a bioethicist
was that I find it very difficult to sort of view these
as morally different
than other tissues in a dish.
I understand that they're different from cells that we normally culture
because they've sort of been given a task to do.
Any manipulation that happens
doesn't yet affect
how an animal interacts with the environment.
It should always be on our radar
that people might do nefarious things with the knowledge
produced or the technologies that are used in this research.
But that's not what people are reacting to
when the public reads that there's a robot made of cells.
I don't think people are sort of wrong
to think, "Oh, that reminds me of Frankenstein."
It's not surprising
that people continue to return to that
trope of scientists
creating things in the lab that are not able to be controlled
because it's one that constantly is in pop culture.
It's in the sort of social imaginary that informs our
our beliefs and our opinions.
Again, it's not going to happen in this case,
but I think the lack of clarity and certainty
about what exactly has been created definitely fuels
a negative reaction among people who read about it.
So there is not scientific consensus about the definition of organism,
and there is not consensus about what is a robot.
The ambiguity about the terms
then yields a moral uncertainty and a moral ambiguity.
What's going on here?
What is it?
It's then wrong for that to be the final word.
It's one input into the calculus
of what do we owe to the creature that we've created?
What are the kinds of safeguards and oversight we should have on the research?
And where do we go from there?
Is the conversation that needs to happen at this point.
I really think about the old story of Adam
naming the animals in the Garden of Eden.
It's the idea that we have to figure out what criteria we're going to use
to establish our relationship with these other beings and from that perspective.
This is the first step towards a new science of really finding
the essence of new types of synthetic organisms by robotics
that are going to be very plentiful in the coming decades.
They're going to be all around us.
We there are quite a few challenges
that we still have to tackle in this field.
I'm a professor of mechanical engineering at MIT,
and in my lab, we specifically look at how we can build
machines that are we call bio hybrid because they're part biological
and part made out of synthetic materials.
The biological robots that we're building
are powered by muscle tissue so that every time the muscle contracts,
you could get something that looks like movement.
The actual muscle tissue that looks like sort of a pink
jelly like rubber band was formed using these mouse
skeletal muscle cells that we had genetically engineered
so that when we shine blue light on them, the muscle would contract.
What we're really thinking about right now is how do we take all these other
cell types like motor neurons
and then get the neurons to grow into the muscle and form
functional connections that can turn portions of the muscle on or off.
We could potentially use that to programed
a clump of stem cells into any sort of shape.
The answer to this one question, what kind of signals
could we give these cells to get them to do something different,
is really the gateway to a profound improvement in human health.
Birth defects, traumatic injury,
cancer, degenerative disease, all of these things could be solved
if we had the ability to tell cells what to build.
Once we understand how this works, we can test this in xenobots
by showing that we can make cells, build whatever structures we want,
and that will go directly towards regenerative medicine inside of bodies
hunting down cancer cells to regenerative repair.
And let's be clear, I don't think that actual xenobots,
of course, made out of frog cells that are going to be in human bodies.
But as we move towards human medicine, the next step is going to be to
make these out of mammalian and eventually out of the patient's own cells.
Making a fully biological robot
that could go inside the body and do some functional task to restore
somebody's health or quality of life
is certainly within the realm of possibility.
But at the end of the day,
we want robots that can tackle a whole bunch of different problems.
We're optimistic
that we can create more and more powerful A.I.
that dreams up more and more complex, useful,
maybe general purpose biobots.
So the obvious next step from a robotics
perspective is to add sensors
so they can move towards or away from a stimuli.
We would like to engineer the system to respond intelligently
to environmental cues of all kinds.
So you could imagine creating sentinel by a robots that sense
contaminants in the environment, and then you retrieve them
and you have a biological readout of what's
going on in the local waterway.
We also have a whole bunch of technological challenges ahead of us.
What we'd like to do, for better or worse, is replace Doug
with a biofabrication facility
that can pump out millions or possibly billions of biobots.
That might allow us to scale up this technology.
But I think their most important long-term implication
is that they are new scientific instrument.
They're a new type of telescope or microscope.
And so we have a whole separate research program
that's spinning off of this to really understand
some of the basic rules that cells use to assemble to treat human disease.
And then, of course, we're going to try to augment their cognitive capacities
by asking, what does it take to make a collection of cells
better at navigating problems in various spaces?
How do we move from just a ball of motors to a ball or another
shape of sensors, memory and motors?
And then maybe we can achieve something that can learn and exhibit
higher level cognition.
That is going to help us to understand
the foundations of neurological intelligence.
Think about it.
We were all single celled organisms once.
We were bacteria before that.
And now you and I feel like an integrated, centralized intelligence
with our own memories and hopes and preferences.
There was no time at which a magic
lightning bolt said, "Okay, before you were just chemistry and physics.
Now you're a cognitive creature." That doesn't happen.
We can't roll the tape of life back on Earth, but we can create xenobots
to ask, how do small,
competent subunits work together to make a larger mind?
That is perhaps the most profound puzzle facing us.
It does feel like
sometimes there's some magic involved in the design process,
and it can feel quite big as these questions
begin to spiral into larger and larger research programs.
There are so many questions here
that are really pushing beyond known boundaries.
They are themselves crashing all of our definitions of organism, of
animal, of robot,
or none of these terms are appropriate now in their original meanings.
But we are most certainly at the edge of many unknowns here.
It's very exciting.
A.I. not just design
parts of biological systems like proteins, but they can design
whole new kinds of organisms that look and act completely differently
from anything else that has existed on Earth.
Mother Nature has been working here
on the planet Earth for 3.5 billion years, and despite her
immense creative capability,
she has only explored a very,
very, very small part of mophospace,
the space of all possible organisms.
It would be
beautiful, and it is beautiful and wondrous
to open our eyes wider to understand
not just life as it is,
but to understand life as it could be.