Long-term implantable flexible neural interfaces for electrophysiological monitoring

With the rapid advancements in materials science, engineering, and microelectronics technology, intelligent dynamic prostheses, guided by motion intention, are progressively replacing conventional prosthetic solutions. Implantable interfaces within the neuromuscular system—including the brain, peripheral nerves, and muscles—can capture physiological electrical signals across a three-dimensional space-time, providing high efficacy in discerning motion intentions. However, challenges such as tissue damage during implantation and the mechanical mismatch between tissue and interfaces hinder their long-term functionality. Therefore, the development of flexible and even stretchable electrodes holds significant promise for long-term implantation applications. Additionally, the diverse cellular compositions across different sections of the brain, peripheral nerves, and the muscle system require specific electrode resolution, mechanical properties, and implantation strategies. This review presents the research progress in flexible implantable interfaces for electrophysiological monitoring, highlights methods to enhance performance and address foreign body responses, and proposes performance requirements and design principles for implantable interfaces across various anatomical regions.