用于电刺激的植入式铂黑微电极

传统的植入式电刺激微电极表面积小，电极／组织界面阻抗高，并且电荷存储容量（CSC）小，这些都会增加植入式系统的功耗并影响电刺激效果．提出了一种在电极点电镀铂黑的方法来增加微电极的有效面积（ESA）．通过在超声波浴下使用脉冲电流电镀的方法，可以极大地增加微电极的ESA，降低界面阻抗并增加CSC和电荷注入容量．铂黑微电极的几何特性和电学特性分别由扫描电子显微镜（SEM）和电化学分析仪测定，并与未镀铂黑的电极特性进行了对比，对铂黑镀层的机械稳定性也做了相应的测试．实验结果表明，铂黑镀层的纳米结构使铂黑电极相比普通铂电极界面阻抗降低了1／16，CSC扩大13倍．在5min的室温超声波衰减实验中，阴极电荷存储容量（CSCc）仅减小20％．

Implantable Pt-Black Coated Microelectrode for Electrical Stimulation

Conventional implantable electrical stimulation microelectrodes have small surface area, high electrode-tissue interface impedance and low charge storage capacity （ CSC ）, which will increase power consumption and hinder stimulation effect. In this paper, a method was presented to increase the effective surface area（ESA） of microelectrode by coating Pt-black on the electrode sites. The method combines with electroplating Pt-black by pulse current under ultrasonic bath, which can significantly increase the ESA, decrease the interface impedance, and increase the CSC and charge-injection capacity. Moreover, the geometrical properties of Pt-black coated microelectrodes were demonstrated by using a scanning elec- tron microscope（SEM） and the electrical properties were measured by an electrochemical analyzer com- pared with conventional microelectrodes without coatings. The mechanical stability of Pt-black coating was also tested. Experimental results show that approximately 16 times lower interface impedance and 13 times higher CSC were achieved by this nanostructured microelectrode. Cathodal charge storage capacity （ CSCc ） decreased only by 20% after an ultrasonic bath at room temperature for 5 min.