Wearable Sweat Biosensor Array for Continuous Multi-Biomarker Monitoring During Exercise

Continuous non-invasive monitoring of metabolic biomarkers during physical activity provides real-time physiological insights for athletic performance optimization and chronic disease management. We present FlexSweat, a flexible wearable biosensor array integrated into a sports wristband format, simultaneously monitoring glucose, lactate, sodium, potassium, and pH in sweat. The array uses enzymatic electrochemical sensors with PEDOT:PSS organic electrodes offering high conformability and sweat compatibility. Calibration-free operation is achieved through ratiometric measurement and a machine learning correction model trained on inter-individual sweat composition variability. Validated against gold-standard blood analysis in 42 healthy adults during graded exercise, FlexSweat achieves mean absolute relative difference of 8.3% for glucose and 6.7% for lactate.