A simple process optimization route to fabricate curved bionic compound eye array

Abstract

Abstract In this paper, a complete and simple process optimization route for the curved bionic compound eye (BCE) array fabrication is presented based on digital micromirror device (DMD) maskless lithography. Firstly, based on the study of edge bulge effect in the thermal reflow process, a proper curved BCE structure is designed. Then, through the optimization of multilayer coating process it can obtain a better uniformity of different photoresist layer and accurate thickness. Next, combined the DMD maskless lithography technology with the Poor Man’s dissolution rate monitor (DRM) approach, well-preformed hierarchical cylindrical structure can be simply fabricated. Lastly, the curved BCE structure can be obtained precisely by choosing the reasonable process control parameters, which depended on the study of two-step thermal reflow processes. This process optimization route makes it very easy to realize the curved BCE array structures with different ommatidium shapes. Experimental results showed the effectiveness of our process optimization method. The presented method is expected to provide a fast, economic and simple strategy for curved BCE array fabrication.