Research On Ultra-compact Micro Multi-spherical Bionic Compound Eye

Bionic curved compound eye is an optical imaging system designed based on the curved surface structure of biological compound eye in nature.Bionic curved compound eye has the advantages of high integration,large field of view,small size and strong functionality,and is suitable for many precise micro-vision fields such as autonomous navigation,panoramic imaging,smart cameras and so on.However,the existing bionic curved compound eye has some problems,such as poor imaging quality,complex structure,difficult miniaturization and high processing difficulty,which make it limited in practical engineering application.Therefore,a micro-scale bionic multi-spherical compound eye structure with large field of view,simple structure and excellent imaging quality is proposed.Two-photon polymerization(TPP)processing technology has nanometer limit manufacturing resolution and high 3D controllability,which provides an effective solution for the manufacture of micro curved compound eye.Therefore,it is of great significance to research on super concise miniature bionic curved compound eye in this paper.(1)Structural design of ultra-compact micro multi-spherical bionic compound eye.Using optical simulation analysis,the influence of sub-eye arrangement on the field of view of curved compound eye is studied.The filling factor of compound eye was explored,and the composition parameters of bionic curved compound eye were determined.In order to improve the development quality of the internal structure of TPP,the designed curved compound eye adds through holes and brackets,and carries out fluid simulation to verify the development advantages of compound eye with gaps.The spot diagrams and Modulation Transfer Function curves were used to evaluate the design.By simulating and analyzing the focal spots of each sub-eye of multi-spherical bionic compound eye and single-spherical bionic compound eye,it is verified that the multi-spherical bionic compound eye solves the phenomenon of defocusing the edge of the field of view of single-spherical bionic compound eye.(2)TPP processing and imaging detection of bionic multi-spherical compound eye.The impacts of different layer thickness,laser power and scanning speed on the forming quality of bionic curved compound eye in TPP were studied.According to the research results,the bionic curved compound eye structure was prepared with the best processing parameters.SEM and white light interferometer were used to detect the surface morphology and size of the bionic curved compound eye structure.Focusing and imaging detection platforms were built to detect the optical performance of qualified bionic curved compound eye samples.It is verified that the actual field of view angle of multi-spherical bionic compound eye is consistent with the theoretical angle.The focusing and imaging comparison between single spherical bionic compound eye and bionic multi-spherical compound eye shows that the bionic multi-spherical compound eye proposed solves the problem of poor imaging quality at the edge of the field of view of single spherical compound eye.(3)Research on image mosaic in large field of view based on SIFT and weighted fusion algorithm.According to the imaging characteristics of curved compound eye.The algorithm of image mosaic and fusion is studied.SIFT algorithm is selected for feature point extraction,and weighted fusion algorithm is selected for image fusion.Experiments on two images and multiple images show that the algorithm is effective.Based on the urgent need of integration,miniaturization and large field of view of medical endoscope,a wireless medical endoscope with bionic multi-spherical compound eye as lens is proposed.