While participating in last year's El Tour de Tucson, a competitive long-distance bicycle race, more than a dozen volunteers were simultaneously participating in and conducting a real-world scientific study, one that involved a diminutive device that rapidly and painlessly analyzes body chemistry from sweat.

Among the volunteers were faculty and students at the University of Arizona and University of Illinois who helped develop a first-of-its-kind soft, stretchable, wearable microfluidic sweat sensor. The device is applied and directly adheres to the skin and measures biomarkers in the wearer's sweat to reveal information regarding internal chemistries, loss of electrolytes, fluid status and the overall body's response to exercise.