Piezoelectric core–shell microstructure-based PVDF nanogenerator with enhanced electrical/mechanical properties for self-powered wireless tactile recognition/speed monitoring systems

With the development of artificial intelligence (AI) and the Internet of Things, self-supplied piezoelectric devices based on polyvinylidene fluoride (PVDF) have attracted widespread attention. However, the piezoelectric output of PVDF is limited, and there is a contradiction between improving piezoelectric performance and maintaining mechanical properties. Herein, a piezoelectric core–shell microstructure- based PVDF nanogenerator with enhanced piezoelectric/mechanical performance is proposed by coaxial electrospinning process. The core–shell microstructure improves the piezoelectric properties through the synergistic effect between the piezoelectric core and shell, while the cladding of the shell helps to maintain the mechanical properties. Moreover, the mechanism of enhanced piezoelectric synergistic effect is revealed by COMSOL simulation. The presented nanogenerators based on AlN-core–shell microstructures outputs is up to 65 V, a 2.3-fold improvement over AlN-doped nanogenerators, along with a 164 % increase in strain. Importantly, the capability of BTO and ZnO core–shell microstructures to enhance piezoelectric/mechanical performance is demonstrated, which proves the proposed strategy is a scalable method. Furthermore, a self-powered wireless tactile recognition and speed monitoring system are developed by combining AI algorithm technology and acquisition circuitry. The recognition accuracy of deformation and shape recognition reached 98.62 % and 98.81 %, respectively. The speed monitoring system can be applied to road interval speed detection. This study provides a new approach to improve the electrical and mechanical properties of PVDF-based nanogenerators, offering favorable support for the application of PVDF-based devices in fields including energy harvesting, device integration, flexible electronics, and human–computer interaction.