Autonomous Self-Healable, Ag Nanowire-Polymer Composite Flexible Electrode for Underwater Sensors

Abstract

The development of self-healing electrodes tailored for underwater wearable sensors is paramount to broaden their applications in aquatic environments. However, autonomous self-healing of flexible electrodes, which encompasses both mechanical and electrical performance, remains a formidable challenge. Here, we present the development of a self-healing flexible electrode (AgNW–FPU), incorporating Ag nanowires (AgNWs) and a fluorine functionalized polyurethane (FPU) substrate. The FPU polymer was designed by systematically adjusting the dynamic bonds and chain mobility to achieve fast self-healing speed and efficiency. Higher dynamic bond content and good chain mobility led to the highest self-healing speed, both in air and underwater. The introduction of a fluorinated side chain enhanced hydrophobicity, further improving underwater self-healing. The AgNW–FPU electrode demonstrated fast underwater self-healing, driven by capillary bridges and enhanced contact between fractured nanowires. The AgNW-FPU electrodes were employed in a capacitive pressure sensor, showcasing its potential for underwater sensing applications.