Replication of Butterfly Scales Nano-Structure with Two-Photon Polymerization Method and the Optical Effect Analysis

Biologically structural colors have been attracting more and more researcher’s attention and many bionics theoretical achievements of this kind may be used for surface decorating and product anti-counterfeiting. But further application has been restricted for the bottleneck problem in specimen manufacture, because of the complexity and nano-dimention of the biological structure. In this work, based on the optimized structure parameters of butterfly scales which have structural color, the specimen was manufactured using the ‘two-photon polymerization method’. Using a femto-second laser system and the photoreswast SU8 of polymer monosomic material, specimen of bionic structural color were prepared. The sample was 30×30μm. The manufacture parameters included that the laser intensity was 5.5-7mw, the distance of the adjacent points was 100nm, the exposure time was 0.6ms, and the numerical aperture of the objective lens was 1.4. The optical effects of the replication structure had been calculated with 1D photonic ‘crystal band gap’ theory. The results of the calculation showed a great consistency with natural butterfly structural color. This work is a meaningful exploration for replication of butterfly or other bionic specimens.