Triboelectric mechanism enhances piezoelectric performance of polyimide composite nanofibrous membrane

Flexible piezoelectric sensor demonstrates significant advancements in wearable electronics. However, the development of piezoelectric materials capable of operating under extreme conditions with exceptional thermal stability remains a critical challenge. Herein, FPI/PAN nanofibrous composite membrane was fabricated via a co-electrospinning technique, achieving a synergistic integration of piezoelectric and triboelectric effects. The synergistic interaction enhances mechanical-to-electrical conversion efficiency through charge superposition and interfacial polarization. The as-prepared sensor demonstrates favorable piezoelectric voltage output of 8 V and rapid response and recovery times (12 ms and 14 ms, respectively). The piezoelectric output remains stable after 10,000 cycles at 15 Hz/10 N, demonstrating excellent durability. In addition, the sensor has the ability to accurately detect diverse human motions, such as joint flexion, eye-blinking, and dynamic impacts. Notably, the FPI/PAN membrane maintains structural stability before 500 °C. Furthermore, it is found that the membrane exhibits a low dielectric constant (1.62-1.67) and smaller dielectric loss (0.0008-0.0024) within the range of 0-1 MHz. This study represents a new path for design and development of self-powered nanofibrous wearable sensors.