Spherically Encapsulated Variable Liquid Lens on Coplanar Electrodes

We herein demonstrated an electrowetting liquid lens using a spherical polymeric encapsulation on coplanar electrodes. In order to vary the focal length, the conductive inner lens was actuated by applying a voltage to the pinwheel-shaped coplanar electrodes. Silicone oil with a low vapor pressure was used as a nonconductive outer liquid lens, which was spherically encapsulated by chemical vapor deposition of thin-film polymer. The use of polymeric (parylene) encapsulation with coplanar indium-tin-oxide (ITO) electrodes provides a unique advantage in achieving an improved transparency, a wafer-level packaging of the liquid lens and the convenient accessibility of the electrical signal.