Expanding Science with 4D Printed Polymers
Transcriber: Phuong Cao
Reviewer: Hani Eldalees
There are things I can’t force,
I must adjust.
There are times when the greatest change
needed is a change of viewpoint.
Let’s talk about cake. I’m
willing to bet that if
I gave everyone watching this your typical
cake ingredients, your flour,
butter, sugar, what have you,
and no recipe that very few of you could
successfully bake me a perfect cake.
Now, correct me if I’m wrong,
but my guess is some would come
out really flat like a pancake
and maybe someone bubble over the top
of the pan and I think we’d make
a big mess. So I want you to keep this
idea of baking a cake without a recipe
on the back burner, and we’re
going to pivot for a minute
and we’re going to talk about me.
I am Bailey Felix and I am
a senior bioengineering student
here at Syracuse University.
Now, growing up has a pretty average kid,
I played sports, but not all that well.
I play the violin. Definitely
wouldn’t call myself great,
but there is one thing that
I really excelled at.
It was finding creative
ways to hurt myself,
playing sports that would then
stomp all my doctors.
So by the time I was 14, I
was having knee surgery.
By the time I was 17, I was in
a back brace that went from
my shoulder blades all
the way down to my tailbone can picture
like a giant plastic corset.
And the route and the commonality in both
of these problems was my doctors didn’t
really know what was wrong or what to do.
So when I hurt my knee at swim practice
and it swelled and I went to the doctor.
They did their imaging, they ran
all their tests and they said,
I don’t think anything’s torn, I
don’t think anything’s broken,
but clearly something’s wrong
because you can’t walk.
So their only explanation
and their only solution
for me was surgery at 14 years old.
Similarly, when I hurt my back,
also at practice,
I go to the doctor and they say, I
don’t think you slipped a disc.
I don’t think anything’s torn. I
don’t think anything’s broken.
But clearly, something’s wrong
because you went from
the able bodied athlete to not being
able to pick up your backpack.
So their solution for me was a back brace,
that giant plastic corset,
and to hope for the best.
So being so young
and facing all of this really left me
wondering if only someone had been doing
the research on what was wrong with me.
Maybe then I wouldn’t be feeling
so miserable right now.
And that led me to the path I’m going
down now with bioengineering
and it really let this passion under me.
And I can stand here and tell you today
that my passion is to revolutionize
the field of health care and medicine
through the power of research.
And I think the team that I’ve
been working with for the past few years
is starting to do just that.
I’ve been working at the Syracuse
Biomaterials Institute under doctors
and Henderson working on 4D printing
shape memory polymers.
And now I know that sounds super
overwhelming. So let’s back it up.
We’ll go back to cake. You’re thinking of
has your flour, sugar, eggs, butter,
the cake I’m thinking of is made of
a special material that we call
a shape memory polymer. Now,
what this means is it’s a special
material that has
the ability to be deformed and held into
a temporary shape and then return to
and remember its original shape.
So picture this for me, something flat,
like a piece of paper,
and you shine a spotlight on it,
you heat it up to a certain temperature
and your flat sheet folds itself into
a cube or it folds itself into a flower.
Or imagine you have a hollow
tube like a PVC pipe
and you shine your special light.
You heat it up to a certain temperature
and that hollow tube shrinks down into
a fraction of the size. This is what
makes our material so cool
and so special.
And it’s what gives us the fourth
dimension to do 4D printing,
so if we were 3-D printing,
our product would be that 3D
holo to like that PVC pipe.
But that fourth dimension comes in when
your PVC pipe shrinks down to
a fraction of its size. That
shape change over time.
Is the 4D that fourth dimension
in 4D printing.
Now, I know that this can be
kind of hard to visualize,
so I have a little clip here for you
and you can watch in real time
the flat sheet curl itself into a tube.
So in seconds, you see a flat sheet
of this special material.
Curl itself up on its own. And this is
the special material for our cake.
So we have our ingredients,
but we can’t just buy this material in
the way that we need to
put it into our oven.
We have to do a little tampering
with it first.
So when we buy this material, it
comes in tiny little pellets.
You can imagine like the
size of the beads,
you make friendship bracelets out of at
summer camp and you can’t put something
so small into our oven,
which is a 3D printer.
So instead, we have to transform it,
melt it down and press it out into
what you see on the right here,
which is a long filament of
our special ingredient,
and this is the ingredient that
goes into our special cake.
So we have our ingredients for this cake
and our oven I’ve mentioned
is this 3D printer,
but the question that we
have is how can we make
the perfect cake since we
have no recipe?
Image you see, again,
here on your right is
the cake that we are looking
to make with our project.
The questions we have to answer to right
in the recipe for this cake or how
the printing process or how the
oven settings will change
the cake that comes out of the oven.
So we ask ourselves, how does
the temperature that we print our
cake at impact its shape change?
So if I print my cake or a bake my
cake at a higher temperature,
does that change its ability
to change into a new shape
and return back to its original shape
versus if I were to print that of
the lower temperature? We also ask,
how does the extrusion multiplier effect
the cake that comes out of the oven?
Not the fancy way of saying if I’m piping
my cake batter into the pan and
I squeeze my piping bag as hard as I can
and it comes up a novel full thickness,
does that change the cake versus if I
don’t squeeze my batter quite as hard
and it only comes out of the nozzle
at maybe ninety five percent in
the last parameter we had
to ask ourselves about,
this is the fiber orientation’s.
This means if I change the direction that
I pour my cake batter into the pan,
will it change its ability to change
shape and return to its original.
So if I were to print it in these
long horizontal directions,
does that change its ability to change
shape versus if I print on a diagonal
or if I print it in these little
vertical directions?
And it turns out this one
really does matter.
So we found that if we print our sample
and we bake our cake piping
the batter into the pan in these
long horizontal sweeps.
We get a better shape change than if we
were to print it in the bottom shorter,
short segments. So at this point,
I think you’re probably all saying
to yourself, OK, Bailey,
I get it cool polymer material, special
material cake shape change. So what?
And there’s really cool things that
researchers are able to do with this
technology and with the special material,
you have researchers like Dr. Hanga who
are creating self expandable cardiac
stents so that this means that they can
create almost like that PVC pipe,
shrink it down to a fraction of its
size and implant it in your body
and trigger it to return to its original
size and open collapsed blood vessels
or blocked blood vessels. You also have
researchers at the University of Colorado,
Denver, who are creating this hernia mesh
out of the special material.
So one of the challenges with
the current hernia mesh is that
it can be kind of sticky.
So to put it inside someone’s
body and get it in
the perfect spot isn’t always
the easiest of things.
But they’ve used the special material in
a way where they can implanted into
the body and have it unravel itself and
uncoil itself into the perfect spot.
So I stand here today to tell you
the really cool things that are now made
more possible because of this research.
So this research has told us the the
recipe for our perfect cake.
We know the ingredients, we have our oven,
and now we know how to put the two
together and not compromise
the shape changeability that makes
our material so special.
And I truly believe that this technology
and these developments are ones
that we will all see in
the coming years in health
care and medicine.
So I want to leave you here today
with this. Who wants cake?