The analysis and investigation on the microelectrode fabrication by electrochemical machining

Electrochemical machining (ECM), also called the electrolysis machining, has become more and more important in micro-machining in recent years. In this paper, a 510 μm tungsten rod was used as the anode, and nickel plates were used as the cathode to fabricate the micro-pin used in scanning tunneling microscope (STM) by electrochemical polishing. Different from the needle shape in STM, a cylindrical shape of microelectrode is desired for the application in electrochemical drilling. The influence of working parameters on the electrode shape is investigated.Experimental results show that low applied voltage, high concentration electrolyte and an appropriate rotation of electrode are preferred to fabricate microelectrodes with diameter less than 100 μm. A higher rotational speed may result in an electrode of conical shape.