Polymer-based piezoelectric materials: Structure, mechanism, applications, and future trends

The increasing need for materials with specific functionalities has spurred significant interest in piezoelectric materials. This study examines polymer-based piezoelectric materials, detailing their fundamental principles, synthesis, properties, and applications. The piezoelectric effect in these polymers originates from the alignment of molecular dipoles, with semi-crystalline polymers like PVDF demonstrating superior piezoelectric responses due to their polar crystalline phases. Various synthesis and fabrication techniques are employed to produce polymer-based piezoelectric materials with tailored properties. Specifically, solution casting enables precise control over film morphology and crystalline phases, while coating methods like spin coating and spray coating facilitate the production of thin films on various substrates. Electrospinning is used to create nanofibres with high surface area and enhanced β-phase formation, and melt processing offers scalability for large-area applications. Additive manufacturing is also emerging as a promising technique for creating complex piezoelectric structures. Piezoelectric polymers are finding increasing importance in applications such as flexible electronics, wearable devices, and smart materials, with the potential to drive innovations in areas like healthcare, environmental monitoring, and human-machine interfaces. Key challenges remain, including the relatively low piezoelectric coefficient of polymers compared to ceramics and the complexities associated with achieving optimal piezoelectric phases and uniform nanoparticle dispersion. Future research should prioritize the development of new polymer materials, enhancing piezoelectric performance through nanocomposites, and simplifying processing techniques to overcome these limitations and expand their industrial and commercial use.