Ultra-Low-Voltage Electrowetting

Electrovariable optical components based on liquid/liquid interfaces encompass microfluidic lenses and mirrors, fiber-optic switches, and display elements. These devices function on the basis of the electrowetting effect, where a liquid interface is deformed by an applied electric field. Existing electrovariable lenses use electrowetting on dielectrics; however, because of voltage losses across the dielectric layer typically a voltage variation of ∼60 V is required to achieve a full focal range. To date the lowest recorded voltage for shape deformation in display elements is 25 V, which is not ideal for portable devices. Herein we investigate the properties of an alternative system, based on the interface between two immiscible electrolytic solutions (ITIES). This system shows promise, reducing the voltage requirement for a substantial electrowetting response by 2 orders of magnitude. Presented are the first experimental demonstration of ITIES-based ultra-low-voltage electrowetting and a preliminary study of its dynamics.