视网膜柔性MEMS微电极的体外电化学稳定性评估  

In-vitro Electrochemical Stability Evaluation of a Flexible MEMS Microelectrode

作　　者：王昱[1] 隋晓红[1] 冯刚[1] 李刚[2] 柴新禹[1] 

机构地区：[1]上海交通大学生物医学工程学院,上海市200240 [2]中国科学院上海微系统与信息技术研究所,上海市200050

出　　处：《中国医疗器械杂志》2013年第1期6-9,共4页Chinese Journal of Medical Instrumentation

基　　金：国家973计划项目(2011CB707503;2011CB707505);国家自然科学基金(61273368;91120304);国家863计划项目(2009AA04Z326)

摘　　要：采用三电极测试法,研究了视网膜柔性MEMS微电极的体外电化学稳定性。结果表明,当体外测试的磷酸缓冲盐溶液的温度在人体生理性体温范围(35oC^40oC)内变化时,电极电化学阻抗没有发生显著变化。此外,在先负后正双相微电流脉冲(幅值为50μA)刺激下,电极附近区域生理盐水的pH值发生变化,且pH的变化值随着刺激电流频率的增大而减小:当频率从1Hz增加到100Hz时,由微电流刺激引发pH的变化值从0.03减小为0.005;而对电极施加单相电流刺激时(频率为150Hz,幅值为50μA),体外生理盐水的pH值随时间呈线性变化:正相刺激后pH值增加了0.15,负相刺激后pH值减小了0.15。Three-electrode testing method was used to investigate the effect of temperature on electrode impedance, and the pH shifts in saline solution resulting from the electrical stimulation were also determined. Experiments in PBS （phosphate buffered solution） solution showed that the electrode impedance was almost invariable at the human body temperature range （35℃ - 40℃）. And the experiments in unbuffered saline solution showed that pH shifts decreased from 0.03 to 0.005 when the frequency of biphasic charged-balanced pulses increased from 1 Hz to 100 Hz. Even stimulated by monophasic pulses （frequency is 15 Hz, amplitude is 50 μA）, the stimulus-induced pH shift of electrode only varies 0.15 （anodic pulse current increased 0.15 and cathodic pulse current decreased 0.15）.

关 键 词：植入式MEMS微电极 视觉假体 电化学阻抗 pH值 温度特性 

分 类 号：R996.3[医药卫生—毒理学] Q6[医药卫生—药学]