Design Of Bionic Compound Eye By Using Electrowetting-based Liquid Lens

Insect compound eyes are natural multi-aperture curved optical system with large field of view,small size,high sensitivity,sensitivity to moving objects,and real-time image analysis and processing.Bionic compound eye system is an optical imaging system designed based on the imaging principle of insect compound eyes,which has been widely used in industrial detection,security,autonomous navigation,robot and other fields.Due to the shortcomings of the traditional bionic compound eye system,such as complicated zoom structure,easy to wear and high cost,the self-zoom liquid lens based on the electrowetting-ondielectric(EWOD)is applied to the design of the bionic compound eye optical system,replacing the complex mechanical focusing device in the traditional bionic compound eye system.In this paper,a bionic compound eye optical system based on electrowetting liquid lens surface array is designed.The bionic compound eye model is constructed by COMSOL software,and the image quality and optical properties of the system are discussed in detail by means of ZEMAX optical software.The main research work is as follows:First of all,this paper introduces the research background and current situation of bionic compound eye system,expounds the physiological structure and optical characteristics of insect compound eyes,summarizes the structure working principle of bionic compound eye system and electrowetting liquid lens,and gives the imaging theory of bionic compound eye and the basic theory of EWOD.Secondly,the model of auto-focusing liquid lens based on EWOD is constructed by COMSOL software,the changes of the double liquid interface in the lens cavity under voltage control are analyzed by simulation,this paper derived the electrowetting liquid lens focal length and the relation between the working voltage,map out the working voltage control through the liquid lens of emergent light divergence and convergence.Thirdly,a bionic compound eye based on electrowetting liquid lens array is designed and the relationship between the imaging position and working voltage is deduced.The effects of base curvature radius,size of sub-eye lens and uniformity of sub-eye arrangement on image quality and optical characteristics of the system are analyzed by means of ZEMAX optical software.The changes in object distance or the position of the receiving sensor,the adaptive focusing ability of the system and the corresponding adjustment range of the imaging receiving surface are discussed and calculated.The results show that the angle of view increases with the increase of base curvature.Compared with the non-uniform lens array,the uniform sub-eye lens array can effectively lower the image aberration of the edge lens.Reducing the size of small lens unit can reduce the aberration of edge lens defocus.The bionic compound eye system can realize adaptive zoom and solve the problem of defocusing aberration caused by the change of object distance and image distance.In other words,the position of the receiving detector is fixed,when the object distance changes,the focal length of the sub-eye lens can be adjusted by controlling the working voltage to refocus the image on the receiving detection surface,which can meet the requirement of high-quality imaging of the object within the depth of field range of 5.2?265.9mm.Accordingly,when the object is stationary,due to the adjustable focal length of the sub-eye lens,the position of the system receiving detector moves to receive imaging within the range of 1.9?15mm according to the actual needs.The related research results will provide a new research idea for the research of imitated compound eye system.