Abstract: Based on conventional electrical discharge machining (EDM), a new method is presented to fabricate tungsten microelectrode instantaneously in a single discharge. The influence of the main working parameters, such as electrode material, polarity, work fluid, pulse duration, peak current, is analyzed by experiments to obtain the microelectrode fabrication law. The forming mechanism is discussed through a lot of experiments and the energy spectrum analysis is carried out on the fabricated microelectrode. As the result of this research, a tungsten micro-electrode 350 μm in length and 30 μm in diameter can be fabri-cated on the top of the tungsten wire 0.125 mm in diameter by this method. And it can be used as tool electrode in drilling micro-hole. At the tip of tungsten microelectrode, the radius is about 100 nm. It can be used as microprobe of scanner and detecting device. This method can increase the efficiency of microelectrode or microprobe greatly. It will be one of powerful methods of fabricating microelectrode or microprobe.

Key words: EDM, Microelectrode, Micro-probe, Rapid fabrication, Single discharge