摘要
在神经工程中,微电极阵列是神经系统与外界电子电路的接口,其性能决定了整个神经系统的信号采集和刺激的效果.提出了一种基于Parylene的半球形柔性生物微电极阵列.在微电极的制备过程中,使用了光刻胶热熔技术和MEMS技术.半球形形貌的微电极有利于形成和神经组织的良好接触,并且相比同底面积的平板电极,表面积增加为2倍,这有利于降低界面阻抗,降低系统功耗.使用化学气相沉积法沉积Parylene C薄膜作为微电极的封装材料,它具有良好的生物相容性和柔性,可以降低对神经组织的损害.实验结果表明,与此半球形微电极底面积大1.3倍的平板电极相比,半球形微电极的界面阻抗下降了55%,并且界面阻抗随着微电极顶部开口直径的变化而变化.使用Comsol有限元软件进行了电极/组织液液面流出电流密度仿真,仿真结果也表明,微电极的流出电流密度也随着微电极顶部开口直径的变化而变化,因此可以通过调整微电极顶部开口直径来调节电流密度,从而满足不同部位需要不同电流密度刺激的要求.
In neural engineering, microelectrode arrays are the interfaces between nervous system and external electronic circuits. Their performance determines the effects of signal acquisition and stimulation of the whole nervous system. A Parylene-based hemispherical flexible microelectrode array was proposed The microelectrode arrays were fabricated by photoresist melt technology and MEMS technology. The hemispherical morphology can ensure good contact between microelectrode and tissue, and will increase surface area to the double size compared with planar microelectrodes with the same bottom area which is helpful in decreasing interface impedance and power consumption. Experimental results showed that the interface impedance of the hemispherical microelectrodes decreased by 55% compared with planar micro- electrodes whose bottom area is 1.3 times larger than that of the hemispherical microelectrodes, and the interface impedance varied with the contact area of microelectrodes and tissue caused by different dimensions of opening on the top of the microelectrodes. Comsol was used to simulate the current density of microeleetrodes. Simulation resuhs showed that the current density also varied with the opening dimension.Current density of microelectrode can be adjusted by adjusting the opening dimension at the top of microelectrode so as to meet the needs of different parts of tissue.
出处
《纳米技术与精密工程》
EI
CAS
CSCD
2011年第5期422-426,共5页
Nanotechnology and Precision Engineering
基金
国家自然科学基金资助项目(60876082)
上海市科委纳米专项基金资助项目(0852nm06600)
上海市教委曙光计划资助项目(08SG13)
航空科学基金资助项目(2008ZE57019)
