Leakage current study for dielectric breakdown in electrowetting systems

In this paper, we study the leakage current and breakdown phenomena of SU8 dielectric film in electrowetting systems. The experimental results showed that the leakage current is negligible when the applied voltage is smaller than the onset voltage of contact angle saturation, but this current exhibits a rapid increase when the applied voltage is higher. Dielectric breakdown occurs when the voltage is further increased and a dramatic increase of current is observed. The film thickness dependence of breakdown current suggests that intermediate dielectric thickness is most advantageous for designing efficient electrowetting systems.