IEEE Spectrum June, 2015 - 34

sensors

Giving Your
Body a "Check
Engine" Light
Temporary
TaTToos can
replace
Today's clunky
biomedical
sensors

by Tekla S. Perry

I turn the key to start the lIttle

Ford SUV I've rented for my visit
to the University of Illinois at UrbanaChampaign, and a message flashes
briefly on the dash: "Tire pressure
low." I ignore it. My own car is 12 years
old; I'm not accustomed to a car that
monitors its own health. Turns out,
though, that the little Ford wasn't kidding. The next morning I find the car
has a flat tire.
Modern cars are laden with sensors
that constantly monitor the vehicle's
vitals and indicate, for example, when a
filter needs replacing or whether the air
bag is working. Electronics diagnose failures after they happen and even predict
problems that are imminent. Wouldn't
it be great if we could monitor our bodies in much the same way?
That very idea, ironically enough,
is what has brought me to Illinois. I'm
34

jun 2015

north american

here to see John Rogers, a materials
science professor at the University of
Illinois with a bold vision: Someday, he
believes, we will all have sensors on
our bodies that send information to a
mobile phone, similar to the way a car's
sensors feed the vehicle's computer.
We've already taken the first steps in
this direction. Many of us now wear fitness bands that track our activity and
heart rate and assume we're sleeping
if we don't move for a while. But most
of these bands aren't exactly chic or
unobtrusive, so even the more diehard among us take them off sometimes. And the information they
dispense is interesting but hardly vital:
They can't detect signs that you're getting sick or tell your doctors anything
they need to know, much less replace
an office visit.
But there's no reason why they can't,
says Rogers. Think about your last
medical exam. Your doctor checked
your pulse, your temperature, your
blood pressure, and maybe your blood

oxygen. If any anomalies showed up,
you may have been sent for further
tests-perhaps an electrocardiogram
for your heart, a blood test to check
for diabetes, electromyography if you
were having muscle weakness, or possibly even a polysomnogram at a sleep
lab to check for apnea. All of these
tests require specialized and costly
equipment, trained medical technicians, or invasive pokes.
These tests-and more-could be
accomplished by means of sensors
so light, durable, and comfortable that
you could wear them on your body for
weeks at a time. It's no distant dream:
At press time, several sensors developed by members of Rogers's research
team had entered or were about to
enter clinical trials in the United States
and Europe, and the first commercial
versions were expected to become
available by the end of this year.
Rogers says these sensors are so
much like skin that you don't notice
you're wearing them-and I didn't
have to take his word for it. I wore
one on my inner forearm for more
than a week. This version was a test
unit that simply transmitted a greeting
when triggered by an Android smartphone; units with biosensors haven't
yet been made available to journalists.
Simple though it was, my sensor
delighted me. It clung unobtrusively
and tenaciously to my arm as I went
about my life-showering, sleeping,
and exercising. It also got me thinking
about how future versions of these sensors are going to make our lives better-
not a decade from now but within a
couple of years, Rogers promises.

by the numbers

1 billion
number of visits to u.s. doctors'
offices in 2010

SPectrum.ieee.orG

the IllInoIs team Isn't the only

one trying to make skinlike electronics. Takao Someya is leading a
group at the University of Tokyo that's
working to develop electronic skin
made of organic semiconductors and

StatiStic Source: 2010 NatioNal ambulatory medical care Survey, cdc

Part 1: Reading the Code

http://SPectrum.ieee.orG

Table of Contents for the Digital Edition of IEEE Spectrum June, 2015