A novel configuration of variable-focus liquid lens based on an electrowetting-on-dielectric technique is presented, which consists of a glass slide coated with a conductive Indium Tin Oxide (ITO) film, a hydrophobic dielectric film, a hollow conical metal ring suspended right above a gap between the slide and the ring, and the lens liquid (water). By changing the voltage applied to a grounded metal ring and a ITO control electrode, both the position and curvature of the liquid meniscus can be reversibly adjusted, and the focal length of the lens can be tuned. The shapes of the suspended ring in the present work are also designed to self-center the lens liquid, then in fluences of different shapes of the suspended rings on the variation of optical power of the meniscus are discussed. Experimental results show that the liquid lens at a good imaging quality is able to focus on objects away from 2.5 cm up to infinity at a 40 V power supply and also able to offer the variation range of the optical power up to 40 m-1. Because of the properties such as low consumption, small sizes and high reversibility and so on, the demonstrated configuration provides great advantages in the field of microlens.%基于介质上电润湿效应提出了一种由覆盖有导电氧化铟锡(ITO)薄膜和疏水介质薄膜的玻璃片,悬浮在玻璃片上方的锥形金属圆环以及透镜中的液体组成的液体变焦透镜结构.通过改变施加在接地金属圆环和ITO控制电极之间的电压,实现了透镜液体的弯月面位置和曲率的可逆调整,从而改变透镜焦距.悬浮的金属圆环同时被用来使透镜中的水滴自居中,讨论了具有自居中效应的不同悬浮圆环形状对弯月面光学功率变化范围的影响.实验结果表明,施加40 V电压可以使透镜样品在2.5 cm和无限远之间聚焦,同时拥有高成像质量,光学功率变化范围达40 m-1.本文设计的液体变焦透镜兼具低功耗、小尺寸和高度可逆等特性,在微透镜应用领域具有很大优势.
展开▼
