Fabrication of Micro-Holes in PMMA Using Micro-ECDM Process: Geometric Characteristics and EC Discharge Behaviour

High-quality micro-features with low production cost are in high demand for the development of cost-effective microfluidic devices. In this work, we present a scalable and cost-effective fabrication process for fabricating blind micro-holes in PMMA substrates via micro-electrochemical discharge machining (Micro-ECDM) for the first time. By providing the suitable applied voltage (V a ), uniformity of the electrochemical (EC) discharges and subsequent geometric characteristics of the micro-holes can be controlled. The stable and unstable EC discharge zones and micro-hole machining quality for different V a and tool conditions have been identified. For unstable and non-uniform EC discharge zone at V a of 26 V, the variation in the micro-hole output parameters is higher compared to stable and uniform EC discharge zones at V a of 28 V and 30 V. Based on the results, micro-holes with appropriate quality have been fabricated and characterized.