Self‐Powered Wireless System for Monitoring Sweat Electrolytes in Personalized Healthcare Wearables

Abstract The demand for non‐invasive health monitoring with wearables poses challenges in developing sustainable, self‐powered systems, as current energy harvesters face issues like complex fabrication, low robustness, and insufficient power density for continuous biosensing. In this study, a wearable self‐powered biosensing platform combining a electromagnetic‐triboelectric hybrid generator (ETHG) with an advanced electrochemical sweat‐ion‐sensing patch is proposed. A Halbach magnet array within the electromagnetic generator (EMG) enhances magnetic flux concentration and power output, while advanced Nylon@polyallylamine and polyvinylidene fluoride@Co 3 O 4 nanofiber films significantly boost the triboelectric generator's performance. Mechanical and theoretical modeling reveals an optimized power output of 328 mW for the EMG and 0.65 mW for the triboelectric component at 6 Hz. This hybrid approach not only enhances the power density but also simplifies the fabrication process and improves the charging performance and robustness of the system. To address potential drift in solid‐contact ion‐selective electrodes, nanoporous carbon ‐modified electrodes increase hydrophobicity, enhancing sensitivity for Na + (56.1 mV dec −1 ), K + (55.2 mV dec −1 ), and Ca 2+ (30.8 mV dec −1 ), along with excellent performance in pH (69.7 mV dec −1 ) sensing. Integrating ETHG with a flexible microfluidics‐enabled patch enables real‐time on‐body sweat monitoring, with data wirelessly transmitted via Bluetooth, offering an efficient and robust platform for continuous health monitoring applications.