A multilayer piezoelectric nanogenerator based on PVDF and BaTiO ₃ nanocomposite with enhanced performance induced by simultaneously electrospinning and electrospraying

Piezoelectric materials have garnered significant interest owing to width range of applications in sensing and energy harvesting by converting environmental mechanical energy to electricity. Improving the performance of piezoelectric nanogenerators (PENGs) is an important challenge to develop these devices. Herein, a novel method was used to enhance the piezoelectricity of the PENGs based on PVDF NFs (polyvinylidene fluoride nanofibers) and BaTiO3 NPs (barium titanate nanoparticles) by simultaneously electrospinning of PVDF NFs and electrospraying of BaTiO3 NPs. Two set of nanogenerator devices were prepared which differ in piezoelectric layer arrangements and volume fraction of piezopolymer and piezoceramic parts. Results showed that, in case of simultaneously electrospinning and electrospraying (E/E), a significant increase in piezoelectric phase content and voltage output has been observed in comparison with the layer by layer arrangement. The improved piezoelctric performace may result from better dipole alignment facilitated by a more intense electric field during the simultaneously E/E process, along with heightened interactions between the two materials arising from enhanced contact in a multilayer configuration. Moreover, the optimum volume ratio of piezopolymer to piezoceramic to obtain the maximum output was 1.5 to 0.5. Therefore, simultaneously E/E effectively enhance the piezoelectric performance without having the common challenges in the electrospinning process of nanocomposites, as well as decreasing the total preparation time and simplifies the processing steps. Having such features, leads to hold great appeal of these nanogenerators for diverse applications.