Advances in flexible piezoelectrics for wearable and implantable medical devices

Abstract Flexible piezoelectric materials have garnered increasing attention due to their potential applications in wearable and implantable medical devices. While wearable technologies provide continuous health monitoring, their reliance on batteries limits long-term usability. In contrast, implantable medical devices (IMDs) offer both monitoring and therapeutic functions, but they face challenges such as power supply limitations, biocompatibility issues and long-term stability concerns. This review focuses on the role of flexible piezoelectric nanogenerators (PENGs) in overcoming these challenges by enabling self-powered operation, high-sensitivity biosensing and therapeutic applications. We discuss how material properties, including piezoelectric performance, mechanical flexibility and biocompatibility, influence device functionality. Additionally, key challenges, including material degradation, encapsulation strategies and integration with existing medical technologies, are examined. By highlighting recent advances in PENG-based IMDs for energy harvesting, physiological monitoring and medical therapies, this review provides insights into the future development of self-sustaining and multifunctional biomedical devices.