MicroEDM

MicroEDM, short for micro electrical discharge machining, is a manufacturing process that extends the EDM principle to micrometer-scale features. It removes material from a conductive workpiece by spark erosion with a matched electrode separated by a small, controllable gap in a dielectric fluid. A sequence of short electrical discharges causes local melting and vaporization, enabling the formation of micro-holes, micro-grooves, and microchannels.

Process and tooling are tailored for micro-scale fabrication. A micro-scale electrode, often made of tungsten, copper, or graphite, is shaped to a fine tip. The workpiece is positioned with high-precision stages, and the dielectric is flushed to clear debris. Pulse parameters such as on-time, off-time, current, and polarity are controlled to manage material removal and surface quality. Micro-EDM can perform drilling, milling, and finishing on a range of conductive materials, including hardened steels, carbides, and ceramics.

Advantages and limitations revolve around feature access and material properties. MicroEDM can produce complex geometries in very hard or brittle materials without mechanical contact, which is advantageous for precision tooling and MEMS components. Limitations include relatively slow material removal rates, electrode wear, and the potential for recast layers or surface roughness. The process requires conductive workpieces or coatings and relies on stable gap control and dielectric flushing.

Applications span precision tooling, micro-optics, medical devices, MEMS components, and microfluidic channels, where fine features and high hardness are needed. Development in microEDM continues to improve feature resolution, control, and multi-axis capabilities for increasingly intricate micro-scale parts.