W
earable devices are a hotbed
of sensors as well as a design
conundrum due to size,
power, and integration challenges.
At the same time, however, major
advancements in sensor and micro-
electromechanical systems (MEMS)
technologies are reinvigorating the
analog side with more accurate mea-
surements and the digital front with
more robust sensor fusion.
For a start, sensor miniaturization
is a key driver for space-constrained
wearable designs. For example,
motion sensors are now available in
tiny packages of 2 × 2 mm for fitness
trackers, smartwatches, and hearables.
And these compact sensors come in-
tegrated with plug-and-play functions
like a step counter, so they can be
easily incorporated even into clothes,
jewelry, and watches.
Take the example of the ICM-
20648, a six-axis motion-tracking chip
from TDK’s InvenSense operation,
which comes integrated with a mo-
tion-sensing processor and software
algorithm. That allows the wearable
sensor IC to offer features such as
a built-in activity classifier, calorie
counter, and bring-to-see gesture
tuned for wrist-worn wearables.
What’s also apparent is that
wearables are commonly associated
with activity-tracking devices such as
fitness bands and sports watches. But
many of these devices are so muchmore than simple monitoring gad-
gets. So there is a need for new types
of sensors that can bring new func-
tionalities to wearable devices. Take
environment sensors, for instance,
that can employ mapping applications
to allow wearable devices to check the
air quality and, thus, identify most
polluted areas in a town.Beyond fitness trackers
The demand for basic wristbands is
waning, and at the same time, the mar-
ket for wearable electronics in health
care is quickly expanding, especially
for personal health-monitoring devices
such as smart patches and digital blood
pressure monitors.
These wearable devices can monitorNew AI features extend performance of
MEMS sensors for wearable designs
Algorithms and software
frameworks drive new
innovations in MEMS sensors
for tiny wearable devices vying
for less power usage and more
AI featuresBY MAJEED AHMAD
Contributing WriterFig. 1: Wearable devices like smartwatches will add more sensors to boost functionality and
utility, extending features beyond simple monitoring gadgets.Fig. 2: The always-on position tracking sensor is optimized for use with GPS/GNSS modules. IMAGE: (TOP) TDK; (BOTTOM) BOSCH SENSORTEC8 FEATURE MEMS & Sensors for Wearables
JANUARY 2019 • electronicproducts.com • ELECTRONIC PRODUCTS