Effects of applied potential, initial gap, and megasonic vibrations on the localized electrochemical deposition of Ni-Co microcolumns

Abstract

This study demonstrates the localized electrochemical deposition (LECD) of nickel–cobalt (Ni-Co) alloy microcolumns and investigates the effects of the experimental parameters on the deposition process. The results revealed that the applied potential significantly affected the surface morphology, deposition rate, and compositions of the Ni-Co microcolumns. Although a high potential significantly improved the deposition rate of the microcolumns, the deterioration of the surface morphologies of the microcolumns was observed. The microcolumns were also deposited at different initial gaps, and smoother surface morphologies were achieved with a relatively larger initial gap. The addition of megasonic vibrations was shown to significantly increase the deposition rate, due to the accelerated ion mass transfer and bubble elimination. Furthermore, the compositions of deposited samples confirmed the anomalous co-deposition behavior of Ni-Co alloys. This study lays the experimental groundwork for potential applications such as micro actuators and magnetic helical microrobots.