Subtle control on hierarchic reflow for the simple and massive fabrication of biomimetic compound eye arrays in polymers for imaging at a large field of view

Abstract

In this work, we demonstrate a simple yet flexible method to fabricate biomimetic compound eye (BCE) arrays in polymers massively by using a novel hierarchic reflow method. In this method, the subtle control on the thermal reflow of different polymeric materials shows that a hierarchic reflow process in polymers can be realized. As a result, ommatidia with a spherical microlens form can be formed on a convex curved surface with a sub-millimeter size. By using the developed method, BCEs with a field of view from 34.21° to 107.95°, ommatidia with a diameter ranging from 5.02 μm to 47.81 μm and numerical aperture ranging from 0.09 to 0.45 have been successfully obtained, which shows the great flexibility and tunability of the fabrication method. The optical tests show that the fabricated BCE has a near diffraction-limited optical performance, which may find application in highly compact endoscopic or surveillance devices as well as in wide-angle illuminating systems. The method developed in this work is flexible and compatible with the standard semiconductor manufacturing process so that it can be adapted to manufacture other useful photonic components with hierarchic microstructures massively and cost-effectively.