Fabrication of Deep Microfeatures in Glass Substrate using Electrochemical Discharge Machining for Biomedical and Microfluidic Applications

Microchannels created in glass-based substrates have wide application in biomedical and microfluidics devices. Electrochemical discharge machining (ECDM) is a low cost method to fabricate microfeatures in electrically nonconductive materials such as glass, quartz, ceramic, etc. In this work, ECDM has been used to fabricate an array of microchannels in soda-lime glass substrate using a pulse power supply and 30% (wt.) KOH electrolyte. Multi-tip array tools with different configurations were used as tool electrode. Deep microchannels of different geometries i.e. straight, spiral, and, zigzag were fabricated using multi-pass micro-milling approach. The effect of pass number on the geometrical characteristics of the microchannel such as depth, width was studied. The surface quality of the fabricated microchannels was analyzed using an optical microscope. The channel depth and width showed an increasing trend with an increase in the pass number. Microchannels with smoother sidewalls and bottom surfaces were fabricated. Tool wear was found to be significant as the channel depth and the pass number was increased.