A conformal sensor for wireless sweat level monitoring

A conformal, wearable and wireless system for continuously monitoring the local body sweat loss during exercise is demonstrated in this work. The sensor system includes a sweat absorber, an inter-digitated capacitance sensor, and a communication hub for data processing and transmission. Experimental results show that the sensor has excellent sensitivity and consistent response to sweat rate and level. A 150% variation in the sensor capacitance is observed with 50μL/cm² of sweat collected in the absorber. During wear tests, the sensor system is placed on the subject´s right anterior thigh for measuring the local sweat response during exercise (eg. running), and the measured sweat loss (147μL) was verified by the weight change within the absorbent material (144mg). With a conformal and wireless design, this system is ideal for applications in sport performance, dehydration monitoring, and health assessment^.