Berkeley: Sweating it out on a treadmill, or racing to finish a half marathon, a runner might risk a potentially dangerous buildup of electrolytes in her blood.In theory a “sweat sensor” could monitor electrolyte levels in real time or track diabetes risk by measuring quick spikes in blood sugar levels. Such a device could find wide use, and make an impact in the marketplace. Current tests monitor these telltale signs only periodically, missing short-term fluctuations or suddenly spiking concentrations. But in a Cory Hall lab that’s been converted into a high tech mini-fitness center, researchers can now trace these metabolic changes second by second in a substance any good work out produces: sweat.
Ali Javey, a materials scientist and professor
of electrical engineering and computer sciences, has combined innovative
materials, sensor technology and integrated circuits to develop a
wearable sweat sensor network that can measure rapid fluctuations in
electrolytes and metabolites, and even the buildup of heavy metal
concentrations in perspiration.
Prototype sweat sensors are
printed on thin plastics and are embedded in headbands or wristbands to
monitor concentration levels of these metabolic markers in real-time.
lightweight sensor network tracks half a dozen chemical markers in
sweat as volunteers toil on a bike in his lab. The sensors within the
film are connected to a flexible electronic board with silicon
Integrated Circuits. The circuit board converts the voltage and current
measures of the sensors to a readout of electrolyte or metabolite
As they huff and puff, runners can monitor spikes
or dips in their electrolytes, metabolites and skin temperature on a
smart phone or other mobile device via Bluetooth. The readouts can also
be transmitted wirelessly to other sites for more detailed analysis.
by the 2016-17 Bakar Fellows Program, Javey is refining the sensor
fabrication process to make it more commercially practical for fitness
training, athletics, health diagnostics and even large-scale population
At the same
time, he is collaborating with exercise physiologists and medical
researchers to determine how reliably the changes measured by the
sensors “map” with workout intensity and certain measures of health
“About half of the California adult population is
pre-diabetic,” Javey says. “It is an alarming condition that leads to
diabetes if your eating and living habits don’t change. But most people
don’t know they have the condition. And many of us hate going to the
doctor — and hate blood draws to determine blood glucose levels.”
research suggests that sweat may be a reliable reservoir to draw on for
moment-to-moment glucose measures, Javey says. Sweat sensors could
provide the first non-invasive and inexpensive home test. In addition,
the sensors could potentially be used to detect the onset of fatigue and
dehydration in athletes during prolonged exercise activities. Finally,
Javey and team has explored detection of heavy metals (e.g., lead) in
sweat as an early exposure detection to these toxic species.
networking of the sensors is a novel design, enabling the device to
detect a combination of chemicals at any given time. The current
project can simultaneously monitor changes in sodium, potassium,
calcium, glucose, lactate, and heavy metal levels, among others.
networked capacity offers the chance to study how different molecular
concentrations vary in relation to each other. Doing so could
potentially help in assessing health conditions or disease risk.
sensors on the wristband or headband are chemically coated electrodes
that measure voltage or current as a proxy for electrolyte
concentration. Electrodes differ based on the type of chemical they are
designed to detect. The integrated circuit portion of this wearable
device converts the measured voltage and current to a readout of a given
chemical concentration. Since signal output is temperature-sensitive,
the chip is also needed to continuously calibrate the sensors to assure
they accurately record concentration as the sweat temperature changes.
his lab advances the sensor network innovation from a prototype to a
potentially commercial device, Javey intends to tap the tech transfer
expertise of mentors in the Bakar Fellows Program, with the aim of
developing a company produce and market the technology.