Fabrication Of High Fill Factor And Small Aperture Bionic Compound Eyes Structure

The biological compound eyes have many advantages of wild field of view,fast temporal resolution,high sensitivity to the moving objects and high energy utilization ratio.The bionic compound eyes have been widely applied to medical endoscopes,panoramic imaging,micro aircraft navigation,wearable devices,high-speed target capture and accurate guidance.But the existing fabrication methods of bionic compound eyes cannot meet all the requirements of high fill factor,small aperture and easily be achieved.Therefore,we present a fabrication method of high fill factor and small aperture bionic compound eyes.The bionic compound eyes structure fabricated by this method have wild field of view,small aperture,wide processing surface range and controllable curved substrate surface.The main contents of this paper are as followed:(1)The structure features and working mechanism of biological compound eyes,the application background and fabrication method of bionic compound eyes are analyzed in detail;(2)The target parameters of bionic compound eyes are designed and then we fabricate micro-lens arrays with 26 um small aperture using the traditional photoresist melting method;(3)We propose a fabrication method of bionic compound eyes of high fill factor and wide processing surface range.Then we analyze the experimental mechanism and surface influence factors of this method.A series of experiments are carried to prove the feasibility of this method.After that,we fabricate the micro-lens arrays structure of small aperture with ommatidium aperture is 30 um and high fill factor with 90.6%;(4)We put forward a new fabrication method for of bionic compound eyes structure--topological mapping method and the experimental mechanism of this method was introduced.The three-dimensional model of elastic membrane was established and the stress analysis was carried out using the finite element analysis software ANSYS 15.0.Then we obtained the displacement of elastic film under different pressure and determine the appropriate gas pressure difference between membrane.After that,we built the experiment system and fabricated elastic PDMS membrane with micro-lens arrays structure on it.At last,the bionic compound eyes structure was fabricated by topological mapping method.The measuring results shown that the bionic compound eyes have good uniformity,smooth surface and clear imaging.