SnO2 induced electrostatic polarization PVDF composite nanofibers for efficient energy harvesting and self-powered wireless monitoring /motion recognition systems

With the rapid development of the Internet of Things and flexible electronics, piezoelectric nanogenerators (PENGs) based on polyvinylidene fluoride (PVDF) have demonstrated a wide range of potential applications in wearable devices. However, there are still challenges in developing high-performance PENGs, which affect their potential applications in more scenarios. Herein, we propose a SnO2-PVDF (SP)-PENG based on low-cost and environment-friendly SnO2 nanoparticles modulated via electrospinning, achieving outstanding piezoelectric output performance. The piezoelectric output of SP-PENG is up to 49.2 V, which is 11.7 times higher than that of pure PVDF-PENG. From the theoretical perspective, the enhanced electrostatic polarization is achieved by the strengthened local electric field due to the presence of low-resistivity SnO2 in the SP fibers. The mechanism of enhanced electrostatic polarization is also declared by COMSOL simulation. Moreover, the SP-PENG exhibits excellent durability (41,600 cycles) and long-term stability (8 months). A self-powered wireless sensing-monitoring system is realized by combining SP-PENG with circuit design. The motion recognition system is accomplished by integrating an assistance of a 1D CNN-LSTM joint learning model, which is verified by an alphabetic handwriting recognition with a classification accuracy up to 100 %. This study provides significant insights for enhancing the performance of PENGs and offers valuable guidance for exploring the application of PENGs in flexible electronics and artificial intelligence.