Endogenous triboelectricity enhancing the piezoelectric performance of fluorinated polyimide foam for sound detection

Abstract

The wearable piezoelectric devices have witnessed significant progress in recent years. Nevertheless, challenges persist in developing wearable piezoelectric sensors with high piezoelectric output performance. This work proposes a unique synergistic coupling mechanism of piezoelectric and triboelectric effects within a porous foam. The fluorinated polyimide/nickel (FPI/Ni) foams were fabricated by incorporating Ni nanoparticles into FPI matrix via a one-step foaming process. An endogenous triboelectric mechanism for enhancing the piezoelectric property of FPI foams via interfacial engineering is proposed. The piezoelectric polarization and interfacial friction between the Ni nanoparticle and FPI matrix within the pores efficiently facilitate charge generation, improving machine-to-electric conversion capability. The resulting FPI foam exhibits exceptional electrical output performance (up to 49 V) and remarkable durability (10,000 cycles). Moreover, the fabricated sensors present precise human motion detection capability and demonstrate significant potential in correcting posture. An advanced artificial visual perception system is constructed with excellent performance in distinguishing complex auditory signals and human speech with different words. This study provides an effective structural design strategy for high-performance piezoelectric sensors, showing exceptional potential for applications in motion monitoring, sound recognition, and self-powered wearable devices in extreme environments.