A Digital Push-Pull Liquid Pump for Tunable Liquid-Filled Lens

A digital push-pull liquid pump is proposed in this paper. The driving force of the push-pull liquid pump is the dielectric force generated from the permittivity discontinuousness of two immiscible liquids. It is used to control the liquid movement in the micro-channel. The liquid movement leads to the liquid volume change of the liquid-filled lens; the curvature of liquid lens changes as the volume changes. Therefore the focal length can be adjusted by the liquid pump. A 10 mm diameter tunable liquid-filled lens with the push-pull liquid pump is demonstrated. A digital electrode design is shown to control precisely the liquid movement by the area of electrode with high applied voltage.