High Sensitivity and Wide Detection Range MXene/PDMS Flexible Piezoresistive Sensor with Microdome Array for Cervical Posture Recognition

Flexible pressure sensors that simultaneously deliver high sensitivity and a broad detection range are highly desirable for wearable electronics but remain constrained by inherent trade-offs. Here, we present a high-performance flexible piezoresistive pressure sensor with microdome-structured MXene/PDMS composites. The sensing mechanism is elucidated through in-situ optical microscopy combined with finite element analysis, which directly visualizes the progressive evolution of the interfacial contact area during microdome deformation under compression. This progressive contact modulation effectively alleviates the sensitivity-range bottleneck. Consequently, the sensor achieves an exceptional sensitivity of 314 kPa-1 in the low-pressure regime while maintaining robust sensing performance across an extended working range (up to 390 kPa). Furthermore, it exhibits fast response and recovery times (31/34 ms) and superior long-term durability over 3000 loading-unloading cycles. This outstanding electromechanical performance enables comprehensive multiscale physiological monitoring, capable of capturing small pressure variations down to 1 kPa including respiratory patterns and arterial pulses, as well as high-load scenarios such as joint flexion and gait monitoring. Building upon these capabilities, a real-time cervical posture recognition system was implemented as a representative paradigm of intelligent health management. By integrating a logistic regression machine learning classifier, the system attained a classification accuracy of 98.5% on the test set. This work proposes a rational structural engineering strategy, providing a versatile and dependable sensing platform for next-generation intelligent health monitoring and human-machine interfaces.