Lens-profile control by electrowetting fabrication technique

In this letter, an electrowetting fabrication technique for the production of lenses is proposed. The unique capability of controlling the lens profile during the electrowetting fabrication processes is successfully demonstrated. The electrowetting fabrication technique involves the use of an electrically conductive ultraviolet (UV)-curable polymer and the electrowetting phenomenon. The control of the lens profile is achieved by adjusting the voltage across a hydrophobic dielectric layer sandwiched between an electrically conductive UV-curable polymer (the liquid) and an electrically conductive substrate (the electrode), and thereby introducing different degrees of the electrowetting phenomenon. For a lens fabricated on a hydrophobic Teflon layer, it is found that when the applied voltage is increased, the focal length increases, and the curvature decreases. Due to its unique ability of controlling the lens profile during fabrication, the electrowetting fabrication technique can be easily adopted for the production of lenses, microlenses, lens or microlens arrays with elements of different focal lengths, and mandrels for lenses or microlenses.