High-Sensitivity Flexible Sensors Based on Island-Bridge Configuration for Real-Time Posture Monitoring Systems.

High-sensitivity, flexible sensors are crucial for precise posture monitoring in wearable electronics. Conventional single conductive network hydrogels suffer from limited strain-impedance response due to isolated conductive fillers. Herein, we propose a novel conjugative effect-assisted internal island-bridge mechanism to construct a sophisticated binary conductive network through p-π stacking and electrostatic interaction between MXene islands and PEDOT:PSS bridges. This island-bridge configuration enables effective disruption and restoration during deformation, overcoming the limitations of single conductive networks. Optimized PVA/MXene/PEDOT:PSS (PMP) hydrogels achieve remarkable 188% increase in conductivity (σ = 21.09 S cm-1) and 98% improvement in sensitivity (GF = 2.31). This exceptional strain-impedance response allows for precise detection of complex joint movements. Furthermore, we developed a lightweight (31 g), low-power (40 mW) wearable posture monitoring system (WPMS) integrating PMP sensors with wireless communication modules for real-time health management through postural analysis and correction. This work presents a theoretical framework for designing high-sensitivity flexible sensors based on island-bridge configurations, advancing the intersection of healthcare and wearable electronics.