The dimension of this gap can vary from a few μm to
100 μm depending on the application and has a dramatic
influence on the machining accuracy. During the machining
process, the motion control logic mainly depends on the
variation of the interelectrode gap (IEG) size. The different
issues influencing the IEG size such as variation in local anodic current efficiency, short circuits and variation of electrolyte
conductivity in the IEG can be met during the ECM or
μECM process [3, 7, 44]. These events influence the material
removal rate and therefore create a non-desired variation of
the IEG.