Skin patch developed to analyze sweat during exercise

There’s a new product being created that could be valuable to triathletes and endurance athletes. Researchers at Northwestern University are developing a skin patch that tests your sweat during exercise to see how the body is responding.

Designed for one-time use, the patch tests key biomarkers as an athlete exercises — these include hydration and electrolyte levels. For triathletes, this could help deliver an early warning that the body is in need of replenishment.

“The intimate skin interface created by this wearable, skin-like microfluidic system enables new measurement capabilities not possible with the kinds of absorbent pads and sponges currently used in sweat collection,” said John A. Rogers, who led the research team.

“Sweat is a rich, chemical broth containing a number of important chemical compounds with physiological health information. By expanding our previously developed ‘epidermal’ electronics platform to include a complex network of microfluidic channels and storage reservoirs, we now can perform biochemical analysis of this important biofluid.”

The patch is easy to use — athletes simply apply the patch to the skin and start moving. Its collects perspiration and moves it to different compartments where it interacts with chemicals that change colour to reflect sweat loss and the perspiration’s acidity level, as well as chloride, glucose and lactate. You can use your smartphone to take a picture of the patch after use with an app that interprets what they mean.

When tested, the patches stayed in place and successfully collected the data of the 21 athletes riding indoors, and 12 riding during an outdoor, long distance bike race.

Rogers see the patch in the same realm as technology like heart rate and power meters  hopes to improve the patch to work for more than just one-time use and expand cover more of the body.