Low voltage electrowetting optical deflector

Abstract

This paper demonstrates a low-operating-voltage electrowetting optical deflector (EOD) by reducing the interfacial surface tension between the electrolyte and the surrounding ambience. The goal of this study was to explore various approaches to achieving a low operating voltage. First, two kinds of fluoropolymers (Teflon® AF1601 and Cytop® CTL-809M) were utilized to confirm the thickness effect and wettability. Second, three different dielectric layers (SiO2, Si3N4, and Ta2O 5) with the same thickness were tested to confirm the dielectric constant effect. Finally, three different surfactants (sodium dodecyl sulfate (SDS), Triton X100, and Triton X15) were used to confirm the interfacial surface tension effect. In this article, we demonstrate that the contact angle of water can change as much as 70° in a dodecane/water/Cytop®/Ta 2O5 system (containing 1% SDS) with 11 V; furthermore, switchable apex angles of ̃±20° and deflection of a beam passing through the meniscus of EOD are presented. © 2011 The Japan Society of Applied Physics.