Electroactive materials for bioelectronics and regenerative medicine: mechanisms, interfaces, and applications

Electroactive materials, capable of generating, transmitting, and modulating electrical signals in physiological environments, have emerged as a cornerstone for bioelectronic devices and regenerative medicine. Recent advancements in conductive hydrogels, piezoelectric, triboelectric, thermoelectric, and optoelectronic systems have provided novel approaches for the development of flexible biological interfaces, self-powered sensing, and low-power electrical stimulation. However, as applications transition from short-term experimental prototypes to long-term wearables and chronic implants, the mere pursuit of high conductivity or output power is no longer sufficient to meet practical demands. Factors such as interface impedance, signal noise, environmental stability, stimulation safety, and scalability in manufacturing have become critical limiting factors in their widespread adoption. This review systematically examines the mechanisms and fundamental properties of various electroactive materials through the lens of biological responses to electrical signals at multiple scales, proposing an integrated framework for defining requirements, selecting materials, fabricating devices, and validating performance. It also summarizes the current research progress and key challenges faced in typical biological application scenarios. Finally, the paper offers insights into the future development directions of electroactive materials in bioelectrical interface engineering, system-level integration, and intelligent manufacturing.