Using polymer and ionic liquid as liquid droplet study in single-plate electrowetting system

In this study, several printing inks were used as liquid medium in single-plate electrowetting system. The goal is to study the feasibility of contact angle change of different liquid on single-plate electrowetting device under low voltage (<;40V). Results showed large ionic molecules inside the aqueous solution can prevent undesired electrolysis with appropriate selection of electrical bias. Addition of ionic surfactants and inorganic salts inside the aqueous solution to decrease interfacial surface condition is another common method used to decrease the electrowetting onset voltage but its concentration needs to be carefully controlled. It was shown that dielectric failure is strongly dependent on the size of the polar liquid molecules themselves. In addition, polymer with appropriate chain length or size and low enough viscosity can improve electrowetting behavior. Throughout this work, an initial guidance to electrowetting practitioners is provided.