The Study Of Liquid Galvanometer Based On Electro Wetting Effect

In recent years,micro devices based on the electricwetting have small size,low power consumption,fast response and other characteristics,so they have been widely used in the microfluidic control technology,optical lens,optical display devices and other fields.The developments in these field are flourishing.Because the display of the intelligent wear-type equipment has large volume,high energy consumption and is not able to achieve a transparent display,a liquid galvanometer based on electro wetting is proposed to solve these problems.In the liquid galvanometer,the droplet driven by high frequency alternating current realizes its resonance,then the beam through the droplet can realize high speed optical scanning.This paper is studying the liquid galvanometer mainly from the simulation and experiments.Firstly,the theory of electrowetting is analyzed and that electrowetting is caused by the effect of horizontal electric field force is known.The driving mechanism of DC and AC current is analyzed respectively.Then,the needle-planar electrode structure is established according to the electrowetting model to simulate the droplet's wetting process,and the results are compared with the experimental results to verify the correctness and rationality of the electrowetting model.The planar electrode structure is obtained by the evolution of the needle-plane electrode structure and the electro wetting driven model.It verifies the mechanism of electro wetting by DC driven.The planar electrode structure is used as a two-dimensional liquid galvanometer structure.The parameters of the galvanometer structure driven by AC current are determined.These parameters make the droplet resonance.On the basis of droplet's resonance,the deflection angles which the beam enters the droplet from different position can be researched by simulation.The results show that the resonant frequency of the droplet is 5.6kHz,and the variation of beam deflection angle is 10.5°.Finally,the electrodes,the dielectric layers and the hydrophobic layer are prepared in order on ITO glass.The electrodes are made by wet etching and the hydrophobic layer is made by spin coating.After these preparation,each dielectric layer is tested for its bearing capacity by applying voltage.The results show that the bearing capacity of each dielectric layer may be related to its thickness,surface cleanliness,impurities in the film and uniformity.