低压双液体变焦透镜的理论及工艺研究

Study on Theory and Technology of Low Voltage Variable-focus Double Liquid Lens

通过对仅有单层介电薄膜双液体变焦透镜模型的相关理论分析,得出介电层薄膜的厚度及均匀性对双液体变焦透镜的性能影响很大,并绘制了双液体变焦透镜焦距与驱动电压、介电层厚度的关系曲线.在此基础上,以降低双液体变焦透镜的驱动电压为目的,对介电层的选择进行了分析,选择既可充当介电层又可充当疏水层的派瑞林材料作为双液体变焦透镜的介电层材料,通过真空蒸发镀膜工艺得到了合适厚度的介电层派瑞林薄膜,并对所镀薄膜表面形貌以及厚度进行了测试.选择氯化钾以及溴代十二烷作为导电液体和油性液体,利用离心方式除去液体中溶有的气体,进而制作完成双液体变焦透镜样品.电驱变焦实验得到低压双液体变焦透镜样品的变焦范围为±20mm,驱动电压约为30V,对于实验过程中出现的迟滞效应,通过对杨氏方程中引入摩擦力项,合理地解释了其原因.

In this paper, theoretical analysis of the cylindrical double-liquid lens model with single-layer dielectric film, tells us that the thickness and uniformity of the dielectric film have great influence on the performance of variable-focus double liquid lens. The relation curve between focal length of liquid lens and driving voltage is drawn. On this basis, parylene is chosen as the dielectric film of low voltage variable-focus double liquid lens to reduce the driving voltage. The parylene film inside the cylindrical chamber with suitable thickness is coated by vacuum evaporation, and the surface appearance and the thickness of the film are also measured. In the experiment, the conducting liquid of potassium chloride and insulating liquid of silicone oil are chosen, with centrifugal degasification processing heore used. At last, a sample of liquid lens is produced. The sample has excellent property with focal range ± 20 V under the maximum driving voltage 30 V. The friction term is introduced into Yong＇s equation and a reasonable explanation is given for the phnomenon of variable-focus hysteresis.