Stick-on patch monitors sweat compounds to determine exercise efficiency

When you're sweating away in the gym or pounding the streets on your morning run, it's important to think that all the misery is going to do some good in the end. But physiology is a more complex thing than most of us realise, and if you aren't managing your nutrients and hydration properly, it is possible that not only is your exercise regime not going to make you more healthy, it might even pose a risk. One thing that can help determine what is going on in your body as you exercise is, ironically enough, your sweat. Researchers at Northwestern University in Illinois have now developed a small, flexible stick-on patch that can analyse sweat and tell wearers or physicians monitoring them whether they are putting themselves in danger, or are on the road to better fitness.

Prof John Rogers, a specialist in biomedical engineering, materials science and neurosurgery at Northwestern's medical school, has for many years worked with Yonggang Huang on stretchy electronics that can move with the skin, and they have now for the first time incorporated these into a device that can analyse biofluids. "Sweat is a rich, chemical broth containing a lot of important compounds with physiological health information," Rogers said. "By expanding our previously developed 'epidermal' electronics platform to include a complex network of microfluidic channels and storage reservoirs, we can now perform biochemical analysis of this important biofluid."