MXene-Based Flexible Sensors: From Innovative Synthesis to Multifunctional Applications and Future Perspectives

Flexible sensors are distinguished from rigid electronic devices by their lightweight characteristics and excellent deformation repeatability. Nonetheless, the suboptimal performance of flexible sensors, such as sensitivity, sensing range, and response time, necessitates the development of advanced optimization strategies, including material composition design, microstructure engineering, and device architecture innovation. The remarkable mechanical properties and high electrical conductivity of MXenes position them as promising materials for flexible sensors. This review systematically summarizes the progress in innovative synthesis methods of MXenes. The tunable conductivity, mechanical flexibility, and multi-functionality of MXenes are discussed. Subsequently, flexible strain and pressure sensors (categorized as piezoresistive, piezoelectric, capacitive, and triboelectric), along with gas and humidity sensors, are systematically analyzed. Finally, key challenges pertaining to biocompatibility and environmental stability are highlighted. Collectively, this review delivers a comprehensive and up-to-date perspective on MXene-based flexible sensors, establishing a robust foundation for future explorations and technological innovations in the field.