Micro EDM Milling with Automated Electrochemical Fabrication of the Cylindrical Microtool

Micro electrical discharge machining in the milling configuration (mu EDM milling) allows machining of complex microparts in a flexible way by controlling the erosion process along the 3D path of a thin cylindrical microtool. This technique is attracting growing interest for the processing of mesoscopic and/or high aspect ratio parts. A bottleneck in the development of this technology is the fabrication of thin diameter tools with large aspect ratios. In this paper, we introduce an innovative mu EDM milling machine along with a machine entirely developed in our laboratory used to form microtools by electrochemical fabrication. The fabrication process is performed automatically according to a method derived from the technology originally developed for the fabrication of Scanning Tunnelling Microscope (STM) tips. Examples of fabricated tungsten microtools with 4 to 10 mu m diameters over a 300 to 800 mu m lengths are presented along with preliminary data about the machining of microfluidic channels in stainless steel and titanium.