Fabrication on low voltage driven electrowetting liquid lens by dip coating processes

Abstract

A low voltage driven electrowetting on dielectric liquid focus lens was fabricated based on a tiny glass tube which had been coated with ITO (indium tin oxide)–Al2O3–TiO2–Teflon multilayered thin films on the inside. Method of sol–gel/chemical solution dip coating was used for the film preparation. A cambered interface between silicon oil and aqueous solution containing NaCl and sodium dodecyl sulfate (SDS) was used for the lens refraction. The curvature of the interface was adjusted by changing the applied voltage. The contact angle of aqueous solution in oil atmosphere was reduced from 155° to 67° when −10V DC was applied. The leakage current was only 28nA at that applied voltage and its focal length changed from −2mm to infinity then to 10mm.