Researchers from the University of California at Berkeley are interested in what perspiration may say about an athlete’s overall health. They developed a wearable smart wristband that monitors the chemicals in sweat in real time, and sends the data to a smart phone app that not only monitors health while exercising and under strain, but that can potentially warn about extreme body temperature, dehydration and fatigue.

Wristband monitors chemicals in perspiration in real time. Image source: UC Berkeley: Wei Gao The wrist band collects data that can be simultaneously and selectively measured through multiple sweat analytes, including metabolites and electrolytes. Sweat contains physiologically rich information which makes it a useful body fluid for non-invasive sensors that can be worn. With five sensors on the flexible band, the device measures skin temperature and calibrates its readings in real time. Glucose and lactate sensors embedded in the band are influenced by body temperature, so the smart wrist band adjusts its readings with the temperature change.

Part of the band is made with flexible plastic, including custom-built sensors that measure concentrations of sodium and potassium ions, the main electrolytes that make sweat salty, as well as levels of glucose and lactate. All of these are indicators of what is occurring on the cellular level. The rest of the device consists of a flexible circuit board that holds 11 standard computer chips. The chips interpret information and transmit it wirelessly.