docs/03_module-2-why-is-it-revolutionary/04_the-revolutionaries/05_3d-printed-battery-paul-braun.en.txt

[MUSIC] Hi. I'm standing here in front of
the Material Science building, here in the insuring quad of
the University of Illinois campus. We're here today to talk
to Professor Paul Braun. Paul's a professor of material science and
engineering here at the University of Illinois, and it's famous for being part
of the team that 3D printed a battery. Now this battery doesn't
look anything like this, but it performs a similar function. We're going to talk to Paul about
this battery, about 3D printing, and how this technology will
change our lives forever. Please join me. Hello Paul, thanks for
meeting with us today. >> My pleasure, thank you. >> Could you tell us a bit about yourself. >> I've been at the University of
Illinois since 1999 as a, on the faculty. Although, I actually was here from
1993-1998 as a graduate student and before that was at Cornell. After finishing my PhD at Illinois, then
I went to Bell Labs for a year, which is really when my work transformed from
things that would say more fundamental chemistry to thinking a lot more about
the technological impact of materials. And then, obviously, came back here
a year after that, where I've been, since I joined as an assistant professor. [SOUND] So my home department is
material science and engineering, and then I have a in chemistry, and we do
some work in the Beckman Institute and the MRL and
a number of the other labs on campus. Everything is made of something, and so material science is what
can you make things out of? How can you improve
the properties of materials? It could be, how do I make stronger
glass for say, a smartphone? How do I make faster computer chips,
more efficient light bulbs, better materials for
doing drug deliveries? You can really think about
materials science as the applied aspects of the chemistry and
physics. Where maybe we don't care as
much about the fundamentals, we still pay attention to them. But, how can we make these building
blocks that impact the world? [SOUND] 3D printing, the way that
we think about it, is very broad, in how can I three dimensionally
structure materials, in what we would call deterministic ways. And so, some of our work on batteries,
we start by doing electroplating. And so, we electroplate nickel. So, a very simple metal. These are easy to electroplate. But we electroplate that using
a very complicated polymer, that when we expose the light
generates some 3D super. Structure. It's akin to a lost-wax process. But then some people will directly print
much more complicated materials to start with, and so using print heads that can
extrude out materials that can withstand very high temperatures, or
that may cause cells to grow in certain ways if you want the three dimensionally
print scaffold for a human organ. [SOUND] We've been really excited by
this idea of 3D printing of a battery, and we realized if you zoom in
on the inside of a battery, really what you have is,
you have three important things. You have something that
can carry the electrons, because batteries have
to have electricity. You have something that can hold
onto the energy storage material, so somehow a battery stores
energy through chemistry. So that's in a material. And typically today, it uses lithium ions. So I have to have some way to
move these lithium ions around. And so what you need is, you need a three
dimensional structure that can conduct electricity, hold onto the active
energy storage material, and provide a really good way to move the ions between
the plus and minus sides of the electrode. And so
conventionally when people make a battery, they do it by casting and
they get a random assortment of materials. And sometimes you have good networks and
sometimes don't, and so the performance varies. But instead, if you could really build it
much the way you think of a city where you have super highways and local roads and
places for the buildings. And so, you'd define the architecture
to give you really efficient eye on transport, really efficient electron
transport and put the energy storage stuff just where you want it,
you can go into new performance metrics. Maybe really high power or
better energy, fast charging. So we started doing this in large form
batteries and this is something we've taken really far and now we have a start
up company working on that, but then, we said, wouldn't it be really interesting
if you could make small batteries that you could print and maybe put them
directly on a silicon a computer chip. And so, we had to think about
new paradigms in materials, because normal battery materials
use high temperatures. Grow some processes that aren't
compatible with computer chips. So we realized, we needed a way to
be able to 3D print the positive and negative terminals directly
onto some substrate. We were able to do this
using optical patterning. So taking this light sensitive polymer. Exposing it with light. When you expose it
multiple beams of light, the way that the light interacts,
creates a 3D pattern in the polymer. We then dissolve a way the polymer of that
hasn't reacted with the light, and so that leave behind what
looks to be like a sponge. We take that sponge and
then we do electroplating, the same way people use to
put chrome on a bumper. We put it in solution and
we fill all the pores with metal, so this is where the electrons can go. Then we remove the polymer,
which was the house initially. And now,
we do a second electroplating process, and a third electroplating process. One grows the positive
side of the battery, one grows the minus side of the battery. And you end up then with fingers
of positive and negative, if you look down on the battery like this. So now they're really close together, which means you can move
the electrons fast. They have lots of pores which
helps you move the electrons, but they're all connected with metal. So using that, we were able to make a battery which
was only a few millimeters on the side. So something like a tenth
of an inch on the side. And about five times
thinner than a human hair. And this battery could generate enough
power to light up an LED and flash an LED. [SOUND] This is not going to replace say,
a laptop battery. Where we think is that,
if we can move power down to the chip, now you could have a really small chip. Maybe a little bigger
than a grain of rice, and then that would have its own battery
built, right in with that chip. Which means, if you took that grain
of rice sized object, and you say, sprinkled it around and
each one had a little radio transmitter or a little blinking light on it,
you could power those wherever they are, without attaching any wires
off to the outside world. You're not going to have a lot of power,
this is batteries. Power is proportional to volume, so you
want a lot of power you get a big battery. You're not going to drive a car
on a tiny little battery. But if you make a battery small,
and you still want a lot of power, you need this 3D structure, so
you can move ions and electrons quickly. And so, that gives you the ability
to pulse out, and send information. So you could have this just sitting
all around and then, once a day, it would send just a little burst of
information that is only possible, because that micro battery's
sitting right by the computer chip. [SOUND] We'll take the applications
really in two space. One is the idea of
three-dimensionally structuring or 3D printing of the internal
components of a battery. You know, we see that applying at sort
of all [INAUDIBLE] scale, so even for sale a large car battery,
if you can control the internal structure, that may give you the ability to
charge the car in say 5 minutes, because now you provide really fast
ways that the ions can move and the electrons can move and
you can put power in to that. And the other regime is when
the batteries get very small. And here, we can really push
the performance metrics to the absolute, because we then control every detail
of the three-dimensional structure. And the applications in that space
are things like, small pills that you might swallow, that have enough power
to be able to transmit a radio signal. Out, or potentially deliver energy
in the body, to do some therapeutic. And, you can make that
a much smaller device, because the battery can still give
you a lot of power when it's small. There's the idea of basically,
the sensors everywhere, so instead of walking around a building and saying, I'll
pick the five places I want to sensor, I make them so small that
they're basically just the dust. And so
you can sprinkle them where you'd like and they can transmit until the battery dies,
and if they're small and environmentally friendly, you can sweep
them up, and maybe they just rust and disappear, so they turn right back into
the iron that's mined out of the earth. Those are just a list of
possible applications. [SOUND] I think you really will be able
to think about changing the design space of products, where today,
if you have a battery-powered product, you generally have to size
it to fit the battery. The microelectronics have
really been miniaturized but the batteries haven't been
equivalently miniaturized. So now,
instead of the device overall function and shape being limited by
the size of the battery. Now, the battery scales
with the electronics. We think if you're going to build
miniaturized electronic devices, the best place to put the power,
is to put it right on the chip. [SOUND] If I think about
the work in Batteries and other, like why would you want to print this? First of all, there's, of course,
the customization aspect. When you make one cell phone for
the masses, you have to limit function in exchange for
mass production. Can we give ourselves this diversity of
customization and retain the function. Because I don't think anyone's going to
a really kludgy cell phone which is four times bigger, just so
it has an extra axes of an accelerometer. But maybe they would be very interested if
the cell phone was designed to be certain shape that fit on their body or
in their clothes in a certain way. And that's not what the next person has,
so I think it's customization for function will be the,
where we can really get legs. Customization for aesthetics is fun,
but maybe not give us the legs we need. To find out more about what we're doing, a great place to start is
just my department webpage. So at University of Illinois, the Material Science department
has a webpage that lists faculty. I give a number of talks that
are sometimes more public interest oriented and
some of these can be found on the web. Then I also have a startup company
working on batteries named Xerion, and they have a webpage that talks about
some of that technology evolution. For detailed inquiries,
people often reach out directly. [SOUND] What I really
enjoyed is that this field is one that nobody is an expert. That it's a new area, it's a growing area. People have made contributions
coming in from everything, from really hardcore physics
through the chemistry through design and engineering. And I think it's really the diversity and the open-endedness of the field that
allows really the human imagination to sort of run wild, and
then reduce it to a tangible object. And that's different than most areas of
engineering, where you go to a catalog and you can pick out this gear and
this gear and that. And if they don't fit,
you are out of luck. I think it really opens up
the human imagination and how we can make the things the world uses. >> Thank you so much. >> Hey, thank you.
>> You did a great job. [MUSIC] [SOUND]