Wearable Sweat Sensor Paves the Way for Real-Time Analysis of Body Chemistry

Wearable Sweat Sensor Paves the Way for Real-Time Analysis of Body Chemistry

flexible-sensor

The flexible sensor developed at UC Berkeley can be made into “smart” wristbands or headbands that provide continuous, real-time analysis of the chemicals in sweat.

 

Materials scientists have created a small, wearable sensor that can read the molecular composition of sweat and send its results in real time to a smartphone. The flexible plastic patches—which can be incorporated into wristbands and headbands—may be able to provide early warning of changes in the body, say their creators.

“The idea is to have this thumbs-up or thumbs-down device that will give real-time information: it could provide an alarm that you need to take some medication, or that you’re getting dehydrated and need to drink some water,” says Ali Javey, at the University of California, Berkeley, who helped to develop the sensors. He and his colleagues report their work in Nature.

Several labs have been developing sensors for sweat, which contains a multitude of electrolytes and metabolites—the final products of the body’s biological processes (for example, the lactic acid that builds up after exercise). But these sensors have tended to measure only one component of sweat at a time, and generally cannot transmit their measurements in real-time.

“Until now, sweat sensors have typically involved patches that are removed for subsequent chemical analysis by separate, non-wearable machines,” says John Rogers at the University of Illinois at Urbana–Champaign, who is also developing wearable electronics.  “The current device is wearable, it provides continuous data streams, and it measures multiple biomarkers simultaneously.”

Perspiration on your phone
Putting together existing advances in wearables technology, Javey’s team made the sensors from a

Users wearing the flexible sensor array can run and move freely while the chemicals in their sweat are measured and analyzed. The resulting data, which is transmitted wirelessly to a mobile device, can be used to help assess and monitor a user’s state of health.
Image by Der-Hsien Lien and Hiroki Ota, UC Berkeley

flexible electronics board joined to a flexible printed plastic sensor array, which can detect glucose, lactate, sodium, potassium and body temperature. When the sensors come into contact with sweat they generate electrical signals that are amplified and filtered, and then calibrated using skin temperature. This step is essential, says Javey: “Electrochemical sensors are very sensitive to temperature, and skin temperature can vary quite a bit when we are sweating.” The data are then wirelessly transmitted to a smartphone.

It’s an impressive achievement, says Jason Heikenfeld at the University of Cincinnati in Ohio, whose lab has also been developing wearable sweat sensors. “The sensors typically require electronics that are normally the size of a shoebox; they miniaturized them into something that can wrap around your wrist,” he says. The sensors have to be fabricated from basic chemicals in the laboratory, and cannot be purchased off the shelf like sensors found in today’s wearables, which measure heart rate and detect the body’s motion.

Challenges ahead

Javey says he has applied for patents on the technology. But there are still many challenges to overcome before

Wearable sensors measure skin temperature in addition to glucose, lactate, sodium and potassium in sweat. Integrated circuits analyze the data and transmit the information wirelessly to a mobile phone.
Image by Der-Hsien Lien and Hiroki Ota, UC Berkeley

you can expect to buy a sweat sensor incorporated into a wearable fitness band. For one thing, scientists aren’t used to working with such tiny quantities of fluid, and people aren’t always sweating. “Many applications will be outside athletics, where wearable bands or patches will have to locally stimulate sweat,” says Heikenfeld.

Sweat sensors will never be as accurate as blood tests, which are the “gold standard”, says Javey. Our bodies closely control the molecular composition of our blood, but the content of our sweat is more variable and is sometimes influenced by microbes on our skin—so the medical relevance of the information that sweat provides will need to be rigorously tested. However, sweat does have an advantage: taking blood samples with a needle is not a practical means of assessing health on a minute-by-minute basis.

In time, the researchers hope to incorporate more sensors that might provide an even deeper picture of what’s happening in the body. “We want to develop medical applications,” Javey says. He points to research suggesting that certain biomarkers in sweat may correlate with symptoms in people with depression. “By looking at those other chemicals we may be able to get information about the mental health of an individual,” he says.

[Scientific American]

February 4, 2016 / by / in , , , , , , , , , ,

Leave a Reply

Show Buttons
Hide Buttons

IMPORTANT MESSAGE: Scooblrinc.com is a website owned and operated by Scooblr, Inc. By accessing this website and any pages thereof, you agree to be bound by the Terms of Use and Privacy Policy, as amended from time to time. Scooblr, Inc. does not verify or assure that information provided by any company offering services is accurate or complete or that the valuation is appropriate. Neither Scooblr nor any of its directors, officers, employees, representatives, affiliates or agents shall have any liability whatsoever arising, for any error or incompleteness of fact or opinion in, or lack of care in the preparation or publication, of the materials posted on this website. Scooblr does not give advice, provide analysis or recommendations regarding any offering, service posted on the website. The information on this website does not constitute an offer of, or the solicitation of an offer to buy or subscribe for, any services to any person in any jurisdiction to whom or in which such offer or solicitation is unlawful.