Song Xiaomin, Zhang Hongxia, Zhang Ziling, Zhao Ruoxin, Jia Dagong, Liu Tiegen
Opt Express. 2021 Mar 15;29(6):8323-8332. doi: 10.1364/OE.418630.
Varifocal lenses (especially large-aperture lenses), which are formed by two immiscible liquids based on electrowetting and dielectrophoretic effects, are usually modulated by an external high-voltage power source, with respect to the volume of the liquid. Hence, a Maxwell force-driven liquid lens with large aperture and low threshold voltage is proposed. With the polarization effect, the accumulated negative charges on the surface of the polyvinyl chloride/dibutyl adipate gel near the anode results in the generation of Maxwell force and deformation with cosine wave. The effect of surface roughness on wettability is linear with the cosine of the contact angle, leading to a sharp reduction in the threshold voltage when the volume of liquid is increased. When the volume of the droplet increases to 80 μl, the threshold voltage is about 10 V. Hence, the aperture of polarization effect-driven liquid lenses can potentially reach the centimeter level. Moreover, when Maxwell force increases, the lens ranges from concave to convex lens, which holds great promise in rich application such as those in light-sheet microscopes and virtual reality systems.
基于电润湿和介电泳效应由两种互不相溶的液体形成的变焦透镜（特别是大孔径透镜），通常通过外部高压电源根据液体体积进行调制。因此，提出了一种具有大孔径和低阈值电压的麦克斯韦力驱动液体透镜。由于极化效应，阳极附近聚氯乙烯/己二酸二丁酯凝胶表面积累的负电荷导致麦克斯韦力的产生和余弦波变形。表面粗糙度对润湿性的影响与接触角的余弦呈线性关系，当液体体积增加时，阈值电压会急剧降低。当液滴体积增加到80 μl时，阈值电压约为10 V。因此，极化效应驱动液体透镜的孔径有可能达到厘米级别。此外，当麦克斯韦力增加时，透镜从凹透镜变为凸透镜，这在诸如光片显微镜和虚拟现实系统等丰富应用中具有很大的前景。
