Large Aperture Electrowetting-Based Liquid Lens

The development of electrowetting-based liquid lens can break the limitations of the traditional zoom system, and its advantages have been paid more attention.Meanwhile, it has become a hot spot and key research direction at home and abroad.In this paper, we propose a large-aperture electrowetting-based liquid lens with a cylindrical cavity design using a combination of upper and lower electrodes.We explain its working principle and give its fabrication process.In developing the electrowetting liquid, a model for classifying the electrowetting conductive liquid is proposed.The electrowetting-based liquid lens proposed in this paper has an aperture of 8 mm,a Parylene C dielectric layer thickness of 3 μm, filled with the same density of electrowetting liquid with a refractive index difference of 0.1581, and the air bubbles in the liquid are extracted in a vacuum chamber.The liquid lens is sealed by an oil-immersion encapsulation process to ensure the hermeticity of the lens.The threshold voltage of the liquid lens is 60 V, and the minimum focal length of the liquid lens is about-68.73 mm and the maximum focal length is close to infinity when the applied voltage is changed from 60 V to 120 V; the voltage is continuously increased to 200 V when it breaks down, at this time, the lens limit of the zoom ratio is 1.8.The lens has good imaging quality throughout the entire zoom process.