High-Performance All-Textile Flexible Piezoelectric Sensor Based on Electrospun MXene/PAN/K-BTO Nanofibers for Wearable Motion Monitoring

Abstract

The all-textile piezoelectric sensor, capable of achieving high-sensitivity pressure sensing while meeting the requirements of wearability, comfort, and structural flexibility, holds great significance for intelligent wearable motion monitoring. In this study, MXene was employed to induce the transition of polyacrylonitrile (PAN) molecular chains from a 31 helical conformation to a planar zigzag conformation, which significantly enhanced the piezoelectric output performance. Under an impulse force of 7 N at 1 Hz, the sensor exhibited an output voltage of 34.1 V, with a sensitivity of 1.51 V/N over the range of 1–9 N. The silver-based knitted fabric electrode (silver-knitted fabric) was knitted on a computerized flat-knitting machine, fully leveraging the advantages of the knitted electrode, including high conductivity (resistance of only 4.2 Ω), high air permeability (1235 mm/s), and excellent structural flexibility. The electrospun MXene/PAN/K-BTO composite nanofiber membrane was subsequently integrated with the silver-based knitted fabric electrode to construct an all-textile flexible piezoelectric sensor with a three-layer sandwich structure. After 2000 consecutive impact cycles, the sensor output signal remained stable without any attenuation. The sensor accurately identified various human motion patterns, including finger bending (approximately 0.08 V), elbow flexion and extension, and walking gait (approximately 18.1 V). Owing to its excellent skin adherence and high sensitivity to subtle movements, this sensor provides an effective monitoring tool for intensive care and consciousness recovery assessment. Furthermore, it holds promising potential for applications in sports health monitoring and human–computer interaction, offering solutions for next-generation embodied intelligence and personalized health monitoring systems.