Implantable Pt-black Coated Microelectrode for Electrical Stimulation

摘要

In Bio-Medical Engineering,implantable stimulation system is helpful to restoring physiological function of organs. Due to the long time implantable system working in vivo, the power consumption of the whole system is crucial. Microelectrodes are very important to this system, its performance determines the power consumption and stimulation effects of the implantable stimulation system. Conventional implantable stimulation microelectrodes have small surface area, high electrode-tissue impedance and low charge storage capacity, which will increase power consumption and hinder stimulation effects. In this paper, we present a simple method to increase effective surface area of microelectrode by coating Pt-black on the electrode sites. The method combines electroplating Pt-black by pulse current under ultrasonic bath, which can significantly increase the effective surface area, decrease the interface impedance,and increase the charge storage capacity(CSC) and charge-injection capacity (Q).inj Moreover, the geometrical and properties of Pt-black coated microelectrodes were demonstrated by using a scanning electron microscope and the electrical properties were measured by an electrochemical analyzer compared with conventional microelectrodes without coatings, and the mechanical stability of pt-black coating was also tested. Experimental results showed that approximately 16 times lower interface impedance and 13 times higher charge storage capacity were achieved for this nanostructured microelectrode, and the decrease of CSC(Cathodal CSC ) only by 20% following an ultrasonic bath at room C temperature for 5min. Such Pt-black coated microelectrode will be promising for Bio-Medical Engineering.