Controlling recast layer and material removal in reverse µEDM for sustainable fabrication of microelectrode arrays

Abstract

Microelectrode arrays (MEAs) are essential for researching neurons and heart tissue because they record and stimulate neuronal activity. For manufacturing MEAs on conductive materials, reverse microelectrical discharge machining, or reverse µEDM, presents a viable method. However, achieving precise MEAs requires control over recast layers generated during micromachining. This study focuses on recast layer thickness (RLT) and material removal rate (MRR) as key performance indicators for sustainable reverse µEDM fabrication of MEAs. RLT affects surface stability, while MRR influences energy consumption and cost. Optimising these responses depends on three input factors: feed rate, capacitance, and voltage. ANOVA analysis reveals that capacitance is crucial in both MRR and recast layer thickness (RLT) in reverse µEDM, contributing to 88.71% and 94.04% simultaneously. A hybrid artificial neural network-genetic algorithm for global optimisation was employed. The optimised parameters 46.5nF capacitance, 110 V voltage, and 5 µm/sec feed yielded a minimum RLT of 1.58 µm and a maximum MRR of 0.3 mm³/min. These advancements signify significant improvements in the precision and efficiency of MEAs fabrication through reverse µEDM, contributing to its sustainable implementation.

Pulsed power supply of Tr-RC and Tr-RLC topologies for improvement of micro electrical discharge machining

“…In other words, in contrast to traditional machining techniques, the micro EDM technique demonstrates a concurrent trade-off between machining efficiency and accuracy: the geometric accuracy of the microholes improves as the machining time decreases. Researchers have developed auxiliary processing techniques to remove interelectrode debris, such as the vibration and rotation of electrodes [14][15][16], which have shown some improvement, but still cannot completely avoid the accumulation of discharge debris in the interelectrode gap [17,18].…”