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Thanks, everyone.
As Megan said, we live with electronics today that is not
limited in the sense of functionality or even
processing power but limited sometimes of its form.
So it's not so much about Moore's Law, but about how
these systems are packaged.
And in particular, we'd like to look at new ways of doing
electronics.
If we look at the ways in which people make electronics
today, they're not creating these interesting fabrics.
They're creating really what are boxy and rigid
systems that are--
as [UNINTELLIGIBLE] spoke about earlier-- they're made
up of circuit boards that are then put into housing.
So if you go back even further in the food chain, they start
on wafer which is, in itself, a rigid substrate.
Those wafers are then diced, and then they go through the
backend packaging process, which puts them into lead
frames and then into chips.
And those chips are then soldered to boards.
Those boards are put into housing, all to protect a very
small amount of silicon that's actually at the heart of these
systems, our phones, our computers, and everything else
that we use in our daily lives.
And so there certainly has been a transition over the
past several decades for electronics to become smaller
and more functional.
Moore's Law has done a wonderful series of things for
us in terms of providing much greater
performance year over year.
But what we'd like to do is take a look at bio-inspired
and conformal-type systems which we think can open up the
use for these types of processes and many, many new
applications and literally taking it out of the box.
There are three fundamental ideas in doing this.
This is work that was done by John Rogers of the University
of Illinois.
He and his team have created a whole new class of systems
that match skin, for example, and its modulus, its
elasticity, and its ability to fold.
And we'll show several examples of that.
Well, one fundamental idea is that using MEMS-like
processes--
Micro-Electro-Mechanical Systems that have been used
for accelerometers and other types of sensors over the past
couple of decades--
is that you can etch silicon in a variety of ways and
actually create flexible silicon nanoribbons.
Now silicon, by itself, is very much like glass, very
brittle, very rigid.
But you make anything thin enough-- whether it be a two
by four turned into a piece of paper--
you can eventually make it thin enough so
that it can be bent.
And in this case, on the right-hand side, we move from
the diving board shown in the center images to interconnects
that buckle out of the plane and can be put on prestressed
elastomers.
These are rubber-like materials.
So we're no longer transferring electronics to
FR-4, which is what--
one of the big concerns in electronics today is all of
the things that are added to that.
But we're in fact able to do devices that are now on
flexible substrates that can then literally strain and
stretch in significant amounts, 100% or
more in many cases.
The second idea is once you've created these flexible
structures, how do you actually remove them from the
wafer that you've created?
Well, you can underetch and release--
also a well-known process--
and then transfer those through a printing mechanism
to this target substrate.
So you go from the mother substrate to a target
substrate, which can be any type of material.
And we'll show several examples of that.
In the lower left-hand corner, you can see a number of arrays
of these micromaterials that can be released from the wafer
and then printed to a target substrate using fairly
conventional types of machines in order to do that--
XY stages, pick-and-place devices, die bonders--
at very small and precise level but very doable.
The third concept is that of creating these stretchable
interconnects which are in effect these mechanisms that
allow you to strain and stretch these devices.
These serpentines that I show here--
and below, you can see some of the strains that are exhibited
and shown in false coloring here that enable that.
And you can have-- as I showed in an earlier slide--
out-of-plane and in-plane-type systems. So combining these
three ideas, you can then create some really interesting
new species of electronics.
And why is this important?
Well, I hope to show you that these new varieties of
electronics can now be used in ways we couldn't use
electronics before, perhaps improving implantable devices
that were just spoken about or putting on the body in a thin
and conformal way that cannot be seen under
your clothes for example.
So these silicon islands connected by interconnects can
be used in homogeneous or heterogeneous arrays of
sensors, computation elements, and so forth.
What we don't want to do is reinvent all of the silicon
that people have done today.
The IP in silicon continues to grow rapidly, and there's a
lot to take advantage of.
And you can actually implement systems not only by making
monolithic structures, but by incorporating [? COTS-type ?]
structures from existing devices and thinning them.
And so they can be incorporated into the systems.
As we zoom out from that array, we can see the density
of these interconnects--
the fabric-like structures that result--
that can be used in a wide variety of structures.
Here shown on a golf ball is one such structure, so you get
an idea of the scale here.
But what's important to note here is that it's truly
conformal, that it's not just covering the surface.
If I took a piece of paper and tried to wrap an orange or a
sphere, it wouldn't conform very well.
You'd have wrinkles and so forth.
It's the problem of the Mercator projection.
But with a stretchable substrate, one that can strain
and deflect, you can now actually cover that service,
not only that, but follow the ridges and the valleys of the
surfaces on top of that larger-scale surface.
So the dimples on the golf ball can then be
conformed to as well.
And so this is a rigid substrate,
the golf ball itself.
But of course, it could be an underlying flexible substrate
that you can attach it to.
And these arrays can be grown and created in the typical
ways that epitaxy is done in the semiconductor industry and
then transferred and printed to a wide variety of
materials, including paper, vinyl,
leather, fabric, and more.
This is an interesting set of materials, but it just shows
that there is a wide variety of materials that this can be
easily transferred to.
And then showing the different types of strain that can
happen in these particular printed materials.
A close up of one of them.
This is the printed material on paper that you can add to.
And why would this be important?
Well, what if you had an LED array, for example, that you
want to deflect and show as a flexible element?
You can do that.
You can have a large number of these devices that are woven
together and then transferred and printed.
And in fact, this could be separate.
You can have a separate process because it's more
economical to actually create a wafer of all LEDs and a
wafer of interconnects and then combine them.
So there are ways to combine these as well, so you don't
have to do it in a monolithic fashion.
This is a finger poking through an LED array.
Now we've had some interesting results with John's group
where implantable LEDs have resulted in some very
interesting emails and volunteers as human subjects
to have LEDs implanted in them.
And I think there's certainly a market for that.
But the point here really is not to show that we can put
LEDs on your body very easily, but that we could put any type
of electronics, whether it's a diagnostic device, a
monitoring device, or even one that delivers therapy.
In this case, together with The Gates Foundation, which is
funding this work, is what we call paper diagnostics.
This is being done in combination with Diagnostics
For All, which is a nonprofit group looking for ways to
deploy paper-based diagnostics in the developing world to be
able to detect diseases.
Microfluidic channels that are imprinted onto a piece of
paper, then upon which are printed
LEDs and photo detectors.
And so you have chemical assays that allow blood and
urine samples, for example, to be used in a way that when
they react in the presence or absence of these diseases,
that that transmittance then becomes a function of whether
that disease is there or not and to what level.
And so this is a very simple way to deploy diagnostics in a
very low cost way, without requiring complex or expensive
electronics.
You don't need to have an add-on to your smartphone, for
example, or send it to a laboratory for assessment.
Now here's an example of where we're starting to look at
interventional devices, catheters specifically.
And this is a tactile array on a catheter in tubular form
that can sense mechanical deformations of the
heart in real time.
And in this next video that you see here, you'll see a
conformal array on the heart that's beating rapidly.
And it's actually sensing in real time.
And there will be a short segment of showing
the data from this.
The important thing before I show this is to realize we're
not looking at a couple of discrete
electograms on the heart.
This is an epicardial application.
We're actually looking at what I think is a cinematic
visualization of what is going on in the heart.
And so that array is sticking to the heart not through any
complex adhesion principle, but van der Waals forces and
surface tension.
And then you can see on the bottom, as the red line
traverses in time, this is actually much
slower than real time.
Those are in seconds on the horizontal axis.
But each one of those pixels represents electrical activity
at that particular point.
And so we've transformed something from a very discrete
sort of lub-dub signal that you might see in a typical
heart monitor now to something that looks at one particular
region, a very small region, with hundreds, not single
digits, of electrodes.
And so what does that do?
That allows us to reveal what the electrical activity on the
surface of the heart -- or the interior of the
heart for that matter--
what can be done with that.
And what the clinicians and the researchers are looking at
right now-- or they're trying to interpolate from a few
discrete points, but now we can do this in a much higher
resolution way, both temporally and spatially.
This offers a tremendous opportunity for us.
This is a tactile array on the exterior of a glove.
So it's printed to a vinyl glove and then
pressed against the heart.
So the surgeon now can have sensors in their finger that
allows them to sense in real time what's
going on on the heart.
And those signals can be brought back and then visually
displayed as well.
So you're essentially putting pixels or eyes in your finger
in a way that was not easily possible before.
Again, those are printed and transferred.
And this is a close-up of the actual array that
was used on the heart.
A little messy now with tissue, and water, and saline
solution dumped on it during the course of the
intervention.
But you can see the various elements and the serpentine
curves that allow it to stretch and flex as the heart
continues to pump blood and move rapidly.
This is an example of a catheter.
This is an interventional device for cardiac
applications in particular.
What we're looking at for this-- and you'll be able to
see this later if you wish--
so I'm expanding the catheter out here.
And it stretches.
And there's a series of electrodes circumferentially
around the balloon.
This is not very dense.
The image shows just a few electrodes, but here we have
about a dozen.
And we're building systems that have far more than that.
We're able to map the pulmonary vein activity for
the purposes of looking at ablation for the correction of
cardiac arrhythmias.
So these are sort of electrical storms of the heart
that propagate through the heart.
And we need ways in which we can actively short circuit
that or rather prevent that from propagating.
By ablating tissue in particular areas, you can stop
those arrhythmias.
So this is an application where the printed electrodes
that are used in the balloon can be both used for the map
and the zap part of arrhythmia correction through ablation
techniques.
The other interesting thing here, although these devices
and the one in this prototype from last year are passive, we
can actually add active CMOS elements in there to do things
like multiplexing, or diagnostics, or provide other
processing techniques right on the balloon.
What we're trying to do is minimize the amount of
material that we have to have traversing the length of the
catheter into the backend consoles.
And so there are wireless techniques and other things
that we can do with respect to that.
So we've done a whole series of animal tests over the past
year and a half, and a lot more exciting things are
happening this year as well.
So one of the also exciting things is perhaps a whole
class of what we call epidermal electronics.
This is a multifunctional device that has both an
antenna, LED, strain gauges, temperature sensors.
This one I'm showing on the image is functional.
This is one of the systems that was built.
This morning, I actually took one of the Band-Aid-type
systems. And this is a non-functioning device, but I
was able to place that on my skin.
I don't know if you can see that, but you're welcome to
ask me to show you my arm later.
This is the same pattern that you see up here, but
transferred to a bandage and applied just
as easily as a Band-Aid.
And now this can be externally powered through induction,
basically field generation of power.
Additionally, you can have communications with the device
and then perform a whole series of things, including
ECG-, EMG-type sensing on the body wherever
you place this unit.
And so this is starting to make you think about classes
of monitoring systems for patients, for example, or
athletes who want to achieve peak performance.
And so there's a lot of interest in different fields
for the ability to monitor people in real time at high
frequency continuously and to get good data from that.
So it's not, again, small, discrete,
low-interval-type reads.
And so this is an earlier one with water-soluble PVA, which
is the substrate that's carrying it.
Now the elastomeric substrate here is only
about 30 microns thick.
The electronics layer is even thinner, less than 7 microns.
So you can see that this is quite thin.
It is thinner than a Band-Aid, much.
And you can think of this-- this is
really a temporary tattoo.
You're applying it in exactly the same way, but now you're
able to deploy electronics on the body and show that.
In final, I think I just want to leave you with the idea
that although I'm showing you some interesting health and
medical applications, there are many more in energy
harvesting and so forth that can be used with this.
Even taking high performance crystalline solar cells,
creating fabrics of those, so they can be deployed very
easily and achieve performance levels that are not attainable
today by organic systems, which are also potential
flexible and stretchable substrate-type materials.
But human-computer interfaces, integrated personal power,
again, the idea of resolution in time and in space, as well
as the idea of body analytics.
Being able to mine information in real time from the body
over large numbers of people, we think will lead to whole
ways of doing clinical research, and monitoring, and
tagging inputs and outputs from people for monitoring
their health.
Thank you.
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