Mimicking bicolor by changing the reflectance of the substrate in a one-dimensional periodic structure

In nature, some beetles can display bicolor on their elytra. In order to explore the bicolor mechanism, we experimentally studied the optical and structural properties of the Carabus lafossei beetle. We found a multilayer structure in the cuticle of the beetle. Due to the different multilayer thicknesses in different areas, the beetle displayed bicolor. Here, we provide another approach to fabricate bicolor by depositing the same multilayer stack on a substrate with different reflectances at different areas. In this paper, the substrate with different reflectances is achieved by prefabricating sculpted hexagons (SU-8) on a silicon substrate. By coating a (ZnS/MgF2)3.5 multilayer, the sculpted structure displays green color at the ridges (SU-8/silicon area) and yellow color at the basins (silicon area).