is a MicroBot microbots what is a micro
bot more typically what is a micro robot
most people just know it from what
they’ve seen in the movies well the
first thing you need to know about a
micro robot is it’s very small so we say
its submillimetre dimensions so for
reference a human hair is about 100
microns in diameter so the robots we’re
talking about here are very small so
about 8 human hair is wide but about 7
human hair is tall next thing we need to
know about these micro robots as we want
them to be mobile to move around in the
work space they want to be able to
control them wirelessly which is a
challenge so if you think about a
large-scale robot right you can put a
battery in this robot powered up and it
goes on its way but what happens if the
robot is really small right so you have
a tiny little robot you can’t stick a
battery on this robot it’s not going to
work so what are we going to do well one
thing we can think about doing is maybe
we can give this robot a little hat it
can make it magnetic and so if we stick
a magnet in its workspace it’s going to
be attracted to that magnet so it’s kind
of the approach that we take here except
we use special mat gets called
electromagnets so we can turn these on
and off whenever we want to and so we
can surround the workspace of the robot
with these electromagnets and control it
to move in the plane so one of the neat
applications for these micro robots is
in the body the body has lots of sticky
rough surfaces in it so if you wanted to
just you know pull our robot with their
electromagnet it’s going to get stuck in
that and that tissue so what can we do
well if you think about a car we want to
take the car off rodent it’s rough
terrain we stick big bulky tires on it
can negotiate that rough terrain so
being fed do the same thing with our
robots so now we can give this robot
some magnetic feet a little bit mattock
different magnetic properties than the
ones on its hat and we can add some
other electromagnets on the work space
and we can turn these on and off now
that the robot will now roll and tumble
like now and go over this rough terrain
just like an all-terrain tire once it
gets to our target location and we can
then use it to inject some medicine to
that target location so that’s the idea
be assigned this microscope tumbling by
a robot that we’ve developed
so it’s about three human hairs wide by
four human hairs long and it looks like
a dumbbell need to bail is a magnetic
body buts your oppositely pulled so in
one side the North Pole’s on the bottom
the other side the North Pole’s on the
top it has two modes of operation so for
this tumbling mode what we can do is we
can turn your electromagnet on from the
bottom and it’s going to call the robot
to stand up we can turn that field off
and put on a somatic field from the side
and call the to tilt over then we remove
that field it’s back on the ground so
now we can cycle this you can get the
robot to roll and tumble to the target
location I also have the second mode of
operation which is called a sliding mode
operation so in this case once we get to
our target location we might have
manipulate something there so how this
works is we again put a Matic field on
the bottom to stand it up then we can
tilt it to the side rather than letting
it fall back to the ground again we can
stand it back up again and we can do
this little stick slip motion and then
get the robot to kind of walk along the
surface and so here’s a video of the
robots that we fabricated in the lab
here at Purdue now so again they’re
about three human hairs wide by four
human hairs long and here we’re manually
controlling these electrode Mattox turn
turning them on and off to get the robot
to tumble along the surface so first was
on a silicon wafer here we’re showing it
on some biological tissue so you get a
sticky surface what you couldn’t just
pull this robot across it without having
this tumbling locomotion here it’s going
on top of a penny so now these features
of the penny are on the same size of the
robot itself it’s able to negotiate that
surface quite well so then once we get
to our target location we want may want
to do manipulation there so here’s the
slotting mode operation so the robot is
kind of walking across the surface and
here you can see it you know pushing a
small little component in this testbed
we’ve also had these robots go over
different bumps
so here’s traversing different bumps on
in the work space so it’s able to
negotiate that quite well we also have
these robots going up and down inclined
planes so we can go up and down these
slopes we’re also looking at alternate
evacuation techniques
it’s rather than tumbling the robot
end-over-end can we tumble it the other
way to get even some even more neat
applications and mobility so this is
application for these robots is inside
the body but there are other biological
applications
for these robots what you’re outside the
body and done it in Petri dishes so when
biologists use a petri dish the grill
typically grow cells and they’re all
congregated into one area so they would
like to take one of these cells move it
out from that group perform an
experiment on it or they would like to
arrange these cells into a certain
configuration for the Grillet scalpel
there are some other tissue engineering
applications so when they do this they
typically use a probe and it will move
the use of probe and actuate it to push
the cell to where it needs to be into it
and to arrange it in some certain matter
one of the problems with this is that
when the user does this they have no
idea how much force they’re actually
pushing the cell with so if you can it
they don’t know how much force they’re
applying to the cell you can damage the
cell so we’d like to be able to come
with the micro robot to help with these
kinds of applications also if you look
at it at a single cell by itself it’s a
pretty neat structure it has a nucleus
in the middle of the cell and it has a
skeleton which is called the
cytoskeleton on the inside and so if you
push them on this cell with it with a
probe and exerts a small force to cell
skeleton will actually reconfigure
itself to be stiffer where that force
was applied and so this is interesting
and so the study of these forces and how
the cell reacts to it and develops is
called mechanobiology is a very popular
field and so people interested in trying
to study this behavior so again we come
with a micro robot can help these
applications that would be great finally
if you look at two different cells they
say L cell a and insell B and you apply
the same force to these cells they may
deform or deflect in different amounts
and this force displacement relationship
for the cells is called its stiffness
and so if we can have a robot to help us
apply these small forces we can record
the stiffness of the cells that help to
characterize them so a normal cell will
have a different stiffness property than
say a cancer cell and so which how can
we come with the market robot to help
with these in vitro or inside a petri
dish applications well what we can do is
we can add our take our magnetic micro
robot so if we have a magnetic body we
control the position of it in the petri
dish by turning electromagnets on and
off but now we need to be able to apply
small forces and record those forces so
how we’re going to do that so we use
something called a vision based micro
force sensor
so what this is it’s a soft compliance
structure and we know the stiffest of
this devices so as it pushes on an
object is going to deform we can now
observe that deformation with the
microscope with a camera attached from a
microscope if we know the deformation
and we know the stiffness then we can
back out what the force is going to be
so here’s an example some one of these
robots called the Micro for sensing
mobile micro robot it’s about 700
microns footprint so seven human hairs
wide seven human hairs long on the back
end of it you can see a little magnetic
body which we’re then using with our
electromagnets to control its position
orientation in the workspace the end
effector that little spring structure is
that soft compliant end effector and you
see how we’re pushing on this
microsphere our cell is deforming and we
track that and we can then figure out
how much force we’re using so now we can
make sure we play in those cells very
safely they also can get this robot to
move autonomously so we can plan a path
around obstacles in the workspace so it
basically gives itself little GPS
coordinates then the robot then can
follow these GPS coordinates
autonomously and then get to the cell
and then push it to its target location
and this works there’s quite well in
this case and here we’re controlling
just one robot at a time so but really
cool we control teams and swarms of
these robots inside they feature just to
have multiple of these robots working
independently all at the same time so
how can we do that well if we go back to
our example with our electromagnets in
our in our robots if we have it say a
team of three robots and we switch these
electromagnets on all these robots are
getting the same global fields and so
they’re all going to do the same thing
so the question is how do you get
independent control of these robots if
they’re all magnetic but what these
electromagnets are are actually just
coils with current running through them
so if we can take these coils and we can
shrink them down to the same size of the
robots roughly and we can kind of turn
them on their end right we can then
arrange them on the bottom of a petri
dish in a big array and then depending
on the direction of the current how it
flows through these coils we can get an
attractive force on the robot or a
postive force on the robot and then by
planning that and in turn and an
attorney these on and off at the right
time we can then get
independent motion of these teams of
microrobots in that network space so
we’ve simulated this this idea and here
you can see three robots being
controlled by these a planar array of
micro coils and we’re able to
independent control these robots we can
also use them for collaborative
manipulation so travelling informations
to move different objects around in the
workspace so we’ve prototyped a system
like this at the millimeter scale well
we have these coils which are about four
millimeters by four millimeters in size
and our robots are two millimeters in
diameter and we are actually able to get
these robots to move independently in
this workspace using this technique so
we know this idea is going to work our
true goal then is actually to move this
not from the millimeter scale and not at
the movements but actually use it at the
micro scale so how do we do that well
it’s possible to make these these micro
coils or you know along the same size of
the robot about 300 microns in diameter
it’s very hard to do it’s very expensive
so what can we do that’s a little bit
cheaper needs and easier to make so if
we want to use some standard printed
circuit board technology instead of
using micro coils we can actually use
micro strips of wire and we can arrange
them in two layers and it works the same
way so now if we have current going in
one direction through one of these
vertical coils and give us a force to
the right on the robot if we change the
direction of current then it will give
us a force to the left and if we use
some of the horizontally mounted coils
and micro strips of wire we can now get
forces going up and forces going down
depending on the direction of the
current and so by doing this we can now
if we put two micro robots in the
workspace we can independently control
their positions in the workspace at the
same time and someone that need
applications here is for advanced
manufacturing if you can then use these
robots to assemble very small components
to commit really interesting devices so
we’re working on some new 3d printing
technology to make essentially micro
scale legos and if we can you think of
anything if you think of you could make
with these legos now you can make here
with this system so it’s pretty exciting
while this is I think a very exciting
application I think the more exciting
and more impactful applications are the
medical domain those are the ones
actually hit closer to home for me and
I’ll tell you why
so growing up and part of a big Italian
family so this is a picture of me and
all my cousins on one side and family is
that my grandfather’s birthday party a
couple years ago we always have a great
time we’re together and usually the life
of the party is my cousin gel which you
can see here next to me
about four years ago Joe suffered a
massive stroke so a stroke is when you
have a blood clot moves from somewhere
in the body into the brain it cuts off
blood flow to the brain if you’re lucky
you can get a drug and it can dissolve
this this this clot or the surging it’s
in a place in the brain where the
surgeon can go when you remove it
himself in Joe’s case in other people’s
cases it can be in a deeper part of the
brain where it’s hard to get out and
then the people can suffer with this
condition for quite a while and Joe
suffered about two years before he
passed away with this so this is
definitely an unscripted event in Joe’s
life in my life but I think these events
you can also use for inspiration and
motivation so now one of my goals is can
we design a robot if we can use for the
applications like this where the surgeon
can’t get up the blood clot but the
robot can can remove that and help
people like Joe to recover learn and
return to a healthy life other
interesting medical applications that
are they’re targeted drug delivery
so these micro robots remember very
small they’re run the same size of of
cells and also tumors so you can load
this with the drugs if you can precisely
control where it’s going to go you know
what’s going to get to the tumor site
you can actually put a lot more drugs on
this and you can how it’s efficiently
done because those drugs traditionally
will get diffused to everywhere in the
body so you can have higher
concentrations of drugs getting to the
target site if you can be delivered with
these micro robots hopefully get some
better patient outcomes that way another
application we break your therapy in
this case you have these radioactive
seeds which need to be delivered to the
tumor site for cancer treatment again
you can have Micro robots deliver these
to the to the site rather than having a
very invasive procedure done which is
currently done so hopefully this
wouldn’t help with recovery don’t forget
better outcomes as well you also can use
these micro robots for biopsies you can
add these little spikes or spokes to the
end of the robot you can then use them
to travel inside the body take a tissue
sample bring it
and in figure out if it’s Kant if a
cancerous tumor or not and hopefully
again less invasively that it’s
currently done right now so the bottom
line is these micro robots and offer
unprecedented capabilities that you just
can’t get with these larger macro scale
robots I mean the future we hope to have
these micro robots around the same size
of red blood cells with onboard
computers cameras intelligence arms
hands and all the sorts of interesting
things so we could do a lot of different
healthcare applications so hopefully
have a better idea of what a micro bot
is now and you can be excited about
these applications as I am in the future
if you can think it the microbots can do
[Music]
the only limit is your imagination
[Music] microbots