Effective Wetting Area at Solid–Liquid Interface Measured by Electrochemical Impedance Method

Abstract

The intermediate wetting state at nano/microstructured surfaces can be described using the partial wetting model between the Wenzel and the Cassie-Baxter models. However, the effective wetting area at solid-liquid interface in the intermediate wetting state is still open for question. In this study, micro-patterned Si surfaces were fabricated by deep reactive-ion etching and its effective wetting area was estimated by the electrochemical impedance measurements. The experimental effective wetting areas were compared with the theoretical predictions and the effect of microstructure size on the wetting state was investigated.