Analysis of Nonaqueous Electrowetting Fluids for Displays

Abstract

Water remains the most extensively studied electrowetting fluid, but few reports exist on nonaqueous conducting solvents. Reported herein is a complete analysis of alternate fluids for electrowetting devices and displays. Emphasis is provided on real-world testing parameters, including contact angle response and immiscibility with oil, environmental range, interfacial tension, ionic content and influence on dielectric reliability, compatibility with additives such as soluble dyes or particle dispersions, and cross-diffusion of fluids or solutes. Out of 16 preselected fluids, six exhibited electrowetting performance comparable to the best aqueous:surfactant solutions. Use of the nonaqueous fluids in advanced display devices is also demonstrated.