A Photo-Curing Method to Prepare Biomimetic Micro-Nano Structure of Butterfly Wing Scale

Abstract

It has been well-known that butterfly wings possess interesting optic properties. Recently, dendritic micro-nanostructure has been found in the wing scales of butterfly Trogonoptera brookiana, which shows excellent light-trapping effect, especially for the visible light. When light enters such a dendritic micro-nanostructure, it will be trapped and eventually absorbed by multiple reflections to generate heat. It is desirable to prepare a biomimetic structure resembling the micro-nanostructure of the butterfly wing scale, which may lead to a new material that can potentially improve the light utilization rate of solar thermal heater and other similar applications. However, a convenient method to make such a structure in large scale is still lacking. Herein, an easy and handy approach has been developed to prepare biomimetic dendritic structure. The starting material is negative photoresist, a chemical reagent which is widely used in photography. A simple device that can adjust the intensity and interval of ultraviolet illumination has been designed and set up. A periodic structure has been achieved via photo-curing with ultraviolet light and the ratio of illumination time has been optimized.