A Flexible Dual-Mode Piezoelectric–Piezoresistive Sensor Based on MXene/PVDF-TrFE Hybrid Film

The advancement of flexible wearable sensors is revolutionizing electronics, medical diagnostics, and human-machine interfaces. However, conventional sensors relying on a single detection mechanism face challenges in capturing both static and dynamic signals. Additionally, their fabrication often requires expensive and complex processes. A cost-effective, highly sensitive dual-mode sensor [flexible dual-mode sensor (FDMS)] integrating piezoelectric and piezoresistive mechanisms was developed to address these challenges. An MXene/PVDF-TrFE hybrid layer was fabricated using a simple solution casting method to ensure enhanced performance, durability, and scalability. The sensing layer’s scanning electron microscopy (SEM) and edge detection analysis confirmed a refined grain structure with uniformly dispersed nanosheets, contributing to superior electromechanical properties. Performance evaluations demonstrate a strong linear correlation between applied pressure and piezoelectric and piezoresistive signals. The FDMS exhibits exceptional piezoelectric sensitivity (87.66 mV/N) and piezoresistive sensitivity of 0.37 kPa1 in the ultralow-pressure range (<0.5 kPa). Its applications in finger joint motion tracking and seat pressure monitoring highlight its potential for wearable technology. With high sensitivity, robustness, and scalable, low-cost production, this study advances multifunctional sensor applications for smart health monitoring and ergonomic assessments.