Electrochemical Self-Healing of the Dielectric Interface in Molybdate-Assisted Electrowetting

Electrowetting is a technology that manipulates the liquid–solid interfacial energy or surface wettability with the aid of an electric field, which can subsequently actuate microfluidics and is not restricted to hydrophobic surfaces. Consequently, it has gained considerable interest in various fields, including biomimetic microsystems, reflective displays, and optical dynamic lenses. However, the intricate liquid–solid interfaces inherent in electrowetting systems present significant challenges, particularly concerning dielectric failure and electrode corrosion under sustained voltage conditions. This raises the following question: how can efficient self-repair be assured within such systems? In this paper, we propose an innovative approach that employs a molybdate solution to assist in the electrochemical passivation of electrowetting, thereby facilitating a low-voltage self-healing technology while mitigating the effects of water electrolysis. We focus on elucidating the underlying mechanisms through a comprehensive analysis of electrochemical reaction processes, supplemented by data derived from transient current curves. The passivation model based on transient current curves is used to gain insights into electrowetting phenomena in liquid–solid systems from the perspective of electrochemical reaction processes rather than conventional solid-state dielectric mechanisms. Our findings indicate that the implementation of self-healing treatments effectively suppresses leakage current in electrowetting systems and enhances the reliability of display device applications. This strategy holds the potential for broader applications across various fields involving microfluidic electrowetting devices that operate on liquid–solid dielectric interfaces, thereby offering promising prospects for future development and application.