植入式硅神经微电极的发展

Development of implantable silicon neural microelectrodes

神经科学和神经工程研究需要研究大脑神经元的电活动情况,以了解大脑产生、传输和处理信息的机制。植入式神经微电极作为一种传感器件,是时间分辨率最高的神经电活动传感手段之一。介绍了国内外几种主要的植入式硅基神经微电极的结构特点、制备方法和性能特点。分析表明,未来通过不断结构优化和改性修饰,特别是在高通量的神经记录方面,通过与同样基于硅材料的电路的集成,硅神经微电极能够进一步提高生物相容性,解决大规模的电极通道体内外传输与连接问题,实现对神经元的在体大规模长时间记录。

The mechanisms by which the brain produces, transmits, and processes information are related with the neuroscience and the neural engineering, involving the electrical activity of brain neurons. As a kind of implantable sensor, the micro neural probe is one of the highest resolution tools used to record the neural activity. It can record electrical potentials of single neurons without damaging the nervous system. In order to record tens of billions of neurons in the brain, the more electrodes that can be simultaneously implanted, the more details of information processing by brain can be obtained. Thus, smaller volume and higher integration are required. As a kind of mature micro machining materials, silicon enjoys excellent mechanical properties and good biological compatibility. The neural microelectrode array fabricated from silicon has the advantages of small size, high integration and good electrical consistency. In this paper, the structure characteristics, the preparation methods and the performance of several mainstream implanted silicon based neural microelectrodes are reviewed. Through the continuous optimization of the structure, and the improvement of the modification methods and methods, the number of electrodes on one probe can be increased greatly, and the bioeompatibility of the silicon based neural electrode be improved dramatically. In the area of high-throughput neural recording, the silicon based electrode fabricated with standard CMOS process and integrated with amplifier, as well as the analogue to digital circuit is a hopeful method to realize large-scale neural recording in-vivo, to replace the point to point connection between the electrode array in body and the recording equipment outside body with several digital lines.