植入式柔性神经电极在活体脑电信号检测中的研究进展

Implantable and Flexible Electronics for in Vivo Brain Activity Recordings

植入式神经电极是记录神经电生理信号的一种重要工具,具有单细胞的空间分辨率和亚毫秒级的时间分辨率,在神经科学和神经修复领域具有重要的应用。微纳米加工技术的发展,为植入式神经电极的构建提供了更多的解决方案。基于微纳米加工的植入式刚性电极,由于存在与大脑组织的力学性能不匹配的问题,容易造成大脑组织的免疫反应,影响神经电信号的长期稳定测量。而近年出现的新型植入式柔性神经电极,可与脑组织形成兼容性的界面,引起的免疫反应小,有利于神经电信号的长期稳定测量。此外,植入式柔性神经电极的微型化、高密度和多功能集成也是脑研究新技术的研究热点。本文主要对近年用于活体脑电信号检测的植入式柔性神经电极的相关研究进展进行了评述,包括柔性神经电极结构、电极组织界面、植入方法、微型化方法和集成方法等。

Implantable electronics are essential for electrophysiological recording at single-neuron and sub-millisecond resolution in the fields of neuroscience and neuroprosthesis.Advances in nano/microfabrication techniques offer new and exciting opportunities for the development of high-density implantable electronics.However,the mechanical mismatch between microfabricated rigid electronics and soft brain tissues has been shown to cause inflammatory responses,leading to signal degradation during chronic recording.Recently,flexible electronics with improved mechanical compatibility to brain tissues have been intensively investigated to improve the performance of chronic neural recordings.Flexible electronics can form conformal interfaces with brain tissue,resulting in minimized inflammatory responses and stable signal recordings.In addition,ultra-small,high-density,and multiple-functionality are also desirable features of flexible neural electronics.In this review,we highlight recent progress in microfabricated flexible electronics for in vivo brain activity recordings,with a focus on structural design,brain/tissue interface,implantation method,minimization and multifunctional integration.