Array Microchannels Formation in Glass Workpiece using Multi-Pass Electrochemical Discharge Milling Technique

In the last two decades, machinability of glass workpiece using electrochemical discharge machining (ECDM) has been widely explored. Microfeatures such as microchannels and microholes in glass workpiece find application in devices pertaining to biomedical and microfluidic fields. The present work reports the fabrication of array microchannels in the glass workpiece using the ECDM process. A multi-pass milling technique was used to create deep channels using stainless steel array tool electrodes and circular ring as anode. Experiments were performed using a pulsed DC power supply and KOH electrolyte (30 % wt.). Effect of the pass numbers i.e. the number of times the array tool electrodes was moved back and forth on the channel depth and width were analyzed. Up to seven passes were used to create straight microchannels and three passes to fabricate spiral-shaped microchannels in the glass workpiece. From the experimental results, it was observed that the microchannel depth and width showed an increasing trend with an increase in the pass number. Optical microscopic images depicted deep microchannels with smooth surfaces were fabricated using the ECDM process.