基于CMOS工艺的抗光噪声神经微电极

Resistant Light Noise Neural Microelectrode Based on CMOS Process

摘要:

为了减小神经电极的宽度,提高电极在光照下的抗噪声干扰能力,提出了一种基于0.18μm CMOS工艺的抗光噪声神经微电极。采用CMOS的多层布线代替传统电极导线的单层排布,并将电极衬底接地以有效减小光噪声。阐述了基于CMOS工艺的神经电极结构设计、制备过程与结构表征,并对所制备的神经电极进行了电化学阻抗测试和光噪声测试。该神经电极宽度仅为70μm,实验证明:1kHz频率下电极的阻抗一致性好,且在1mW/mm2的光遗传常用光辐照下,该电极的噪声电压仅为0.07~0.08mV,远低于传统硅电极12~13mV的噪声幅值。结果表明,基于CMOS工艺的神经电极抗光噪声能力远优于传统硅电极,对硅基微电极在光遗传中的应用具有重要意义。

Abstract:

In order to reduce the width of the neural electrode and improve the antinoise ability of the electrode under illumination, a neural microelectrode resistant to light noise was proposed based on 0.18μm CMOS process. Multilayer wiring was used to replace the singlelayer arrangement of conventional electrode. And the substrate of the electrode was grounded to effectively reduce the light noise. The structure design, preparation process and structural characterization of the neural electrode were described. The prepared neural electrode was tested for electrochemical impedance and light noise. The width of the neural electrode based on CMOS process is only 70μm. Experiments show that the consistency of the electrode impedance is good at 1kHz. In addition, the noise voltage of this electrode is only 0.07~0.08mV under the irradiation of commonly used light of 1mW/mm2, which is much lower than the noise amplitude of the traditional silicon electrode of 12~13mV.The results show that the resistance to light noise of the neural electrode based on CMOS process is much better than that of traditional silicon electrodes. It is of great significance to the application of siliconbased microelectrodes in optogenetics.