How skin patch can diagnose your health while you sweat

Researchers in the US are creating a skin patch that can test sweat droplets while people exercise and send the results to their smartphones, in a new way to track health and fitness.

The experimental gadget, the size of a small coin, goes well beyond activity monitors such as the Fitbit.

“Sweat has biochemical components that tell us a lot about physiological health,” says JohnRogers, who led the research and directs Northwestern University’s Centre for Bio-Integrated Electronics in Illinois.

Today’s wearable technology helps people track their calories, activity and heart rate. A wearable biosensor would be “radically different”, Rogers says.

For simple fitness purposes, it could give an early warning that it’s time to replenish electrolytes before someone starts to feel dehydrated. But eventually with additional research, Rogers envisions more sophisticated use of such devices, such as real-time monitoring of how the body adjusts during military training, or to screen people for diseases such as diabetes or cystic fibrosis.

Rogers, who did much of the research while at the University of Illinois at Urbana-Champaign, has worked to develop electronic devices that can stretch and twist with the body. The skin-like sweat patch adds a capability called microfluidics, capturing and analysing tiny amounts of body fluid.