Wetting Mechanism And Experimental Research On Electrically Controlled Liquid Interface

With the rapid development of science technology,microfluidic technology of controlling micro-droplet came into being.The liquid zoom lens based on the principle of electrowetting has many advantages,such as fast response,wide zoom range,low energy consumption,image stablility and so on,and it is widely used in the field of micro-optics such as mobile phone camera and microscope,and has attracted the close attention of researchers at home and abroad.Compared with the traditional optical imaging system,it not only overcomes the problems of large structure size,slow response speed,optical accumulation error and optical distortion error,but also meets the requirements of modern miniaturization,integration and intelligent optical system.Based on this,a double liquid zoom lens based on the principle of electrowetting is proposed,and makes an in-depth research on the key scientific problem of electrowetting liquid zoom lens——electrowetting mechanism of droplets on the surface of dielectric films from both theoretical analysis and experimental test,and the specific contents include the following aspects:Research on the wetting mechanism of electrically controlled under the action of direct current(DC)electric field: Based on the principle of electrowetting,a theoretical model of electrowetting is constructed,which is coupled with driving voltage,dielectric layer thickness,ambient temperature and gravity(droplet volume).According to the principle of minimum energy and the volume of the droplets are constant.The electrowetting mathematical equations of the contact angle and driving voltage,dielectric layer thickness,ambient temperature and gravity(droplet volume)under DC condition are established.Research on the contact interface behavior of electrowetting effect: The electrowetting behavior of Na Cl droplets on the surface of parylene films was researched and analyzed by orthogonal experimental design.At the same time,the theoretical analysis results were compared with the experimental test results,and the correctness of the experimental results was verified theoretically.In addition,based on the best experimental results of orthogonal experiments,the influence of single factors such as driving voltage,dielectric layer thickness,ambient temperature and gravity(droplet volume)on the electrowetting behavior of Na Cl droplets on the surface of parylene films under DC condition was investigated emphatically.Research on the distribution of electric field and its control strategy: Starting from the Lippmann-Young equation,the equivalent theoretical model of alternating current(AC)electrowetting is constructed,and the mathematical equations of electrowetting is established,which is coupled with the main factors such as contact angle and driving voltage,dielectric layer thickness and AC frequency under AC condition.The electrowetting behavior of Na Cl droplets on the surface of the parylene films was researched and analyzed by orthogonal experimental design,and the theoretical analysis results were compared with the experimental test results,and the correctness of the experimental results was verified theoretically.In addition,based on the best experimental results of orthogonal experiments,the influence of single factors such as driving voltage,dielectric layer thickness and AC frequency on the electrowetting behavior of Na Cl droplets on the surface of the parylene films under AC voltage was investigated emphatically.According to the above analysis,this study provides an effective theoretical basis for liquid zoom lens,which can be applied to extreme conditions such as temperature environment and AC electric field,and provides theoretical basis for the application of dielectric wetting theory in practical engineering,and also has important guiding significance for the development,design,optimization and performance improvement of electrowetting liquid zoom lens.