Self-powered multifunctional flexible sensor for wearable biomonitoring

Wearable sensors advance toward the goal of multifunction and integration. Most previous researches focus on the pressure or temperature sensibility, while moisture perception enabling proximity sense and noncontact control of soft robotic and human-machine interfacing still remains a challenge. Herein, we reported a flexible self-powered multifunctional sensor (FSMS) based on fluoropolymer composites for simultaneously and actively detecting the moist, thermal and pressure stimuli. The inclusion of lithium chloride (LiCl) and polyvinyl alcohol (PVA) endows the fluoropolymer composites with excellent humidity sensing capabilities of low hysteresis (2.1%) and short response time (9 s). The as-prepared FSMS can be easily worn on versatile places of human body for wearable biomonitoring of arterial pulse and respiration as well as human-machine interaction. A moist-thermal coupling (MTC) mode is invented to boost the sensitivity for respiratory monitoring and noncontact human-machine interaction. This work opens up a new paradigm to develop multifunctional biomonitoring devices and artificial skin for next-generation wearable electronics.