The Ga-Sb and Ga-AgCl liquid metal-based electrodes with self-healing for sweat pH Sensors

Abstract

Flexible electronic devices with self-healing have garnered a wide attention, and the development of liquid metal-based electrode may extend their applications. The application of self-healing electronics is challenging and has not fully proven in a complex physiological environment. Herein, a one-step method prepared Ga-Sb and Ga-AgCl inks were employed to fabricate pH and reference electrodes for self-healing sweat pH devices. The Ga-Sb electrode exhibited a high pH sensitivity (62 mV/pH), small hysteresis (12 mV), excellent stability (1.5 mV/h) and selectivity. The Ga-AgCl electrode was insensitive to pH but demonstrated favorable selectivity and stability (2 mV/h), especially in solutions with halide ion. The wearable sweat pH sensor, incorporating both the two electrodes, offered real-time pH monitoring with excellent response performance. Additionally, these electrodes could be effectively repaired by simple heating treatment and maintained stable performance. This study provides a novel approach for the development of repairable and durable wearable sweat detecting devices.