Electrochemical etching technique for tungsten electrodes with controllable profiles for micro-electrical discharge machining

Lately, the development of micro/nano-scale devices in optics, displays, communications, electronics, and fuel-cell industries has given rise to the advent of various micro-machining techniques for fabricating microstructures. Moreover, the demand for the fabrication of complicated microstructures increases constantly. Micro-EDM is one of many methods that has been used to successfully fabricate microstructures, hence the need for high-quality micro-electrode tools is also growing. There are several well-known fabrication techniques such as reverse electrical discharge machining and wire electrical discharge grinding. However, these are limited by low aspect ratio and lengthy fabrication time. In this paper, we propose a novel micro electrode fabrication process with low-cost, easy setup, and quick and flexible implementation compared to commonly used methods. Our approach is based on the electrochemical etching technique. In this technique, a tungsten wire is etched until we obtain a desired profile. Several experiments were carried out to analyze the etching parameters and to evaluate the accuracy of our proposed method. The results detailed the role of every key parameter such as applied voltage, ring diameter, oscillation speed, etc... And demonstrated that this method can be used to fabricate a desired micro-electrode in a 16-minute timeframe with an error of less than 7%.