Getting on the elliptical machine is half the battle, but what does sweat really tell you? Researchers have developed a flexible device that sticks to the skin, analyzes your sweat and sends the results to your smartphone.
Researchers say the device — about the size of a quarter — offers insight into whether you need to drink more water or down an energy drink to boost electrolyte levels.
“The intimate skin interface created by this wearable, skin-like … system enables new measurement capabilities not possible with the kinds of absorbent pads and sponges currently used in sweat collection,” said John Rogers, lead author of a study reporting development of the “lab on the skin.”
Rogers is a professor of materials science and engineering, biomedical engineering and neurological surgery at Northwestern University’s McCormick School of Engineering in Evanston, Ill.
You stick the patch on your skin when you start moving and tiny channels collect your sweat and route it to different compartments where it interacts with chemicals that change color to reflect sweat loss, the acidity level of perspiration, and concentrations of chloride, glucose, and lactate. To get the data, a user takes a smartphone photo of the device. An app then analyzes that photo and displays the information.
The device is disposable, designed to be used once for a few hours while attached to the skin of the forearm or back. “Sweat has biochemical components within it that tell us a lot about physiological health,” said Rogers.
Why bother analyzing sweat?
Rogers said in a university news release, it’s “a rich, chemical broth containing a number of important chemical compounds with physiological health information.” Researchers tested the device on two groups of cyclists and reported their findings in the journal Science Translational Medicine. They said the device gave accurate accounts of the acidity of sweat and concentrations of glucose, chloride, and lactate.
The patches stayed in place and worked even when people wore them in an outdoor race. The sweat patches are designed for a one-time use over a couple of hours.