A multi-layer film model for formation mechanism of bright whiteness in beetle scale

By taking the optical imaging of the internal micro-nanostructure of white beetle scales, a multilayer aperiodic model is presented in this paper to understand the complex natural formation mechanism of bright whiteness of a kind of white color beetle. Based on the proposed model, optical simulations of visible light reflectivity are conducted correlated with the variation of layer number, layer thickness and incident angle of visible light with alteration of the air-layer and chitin layer. The results showed larger incident angle will lead to lower reflectivity, smaller number of layers will also lead to lower reflectivity and higher fluctuations within the range of visible bandwidth. The simulated results match well with the measured reflective data, and the proposed model is reliable to interpret the formation mechanism of bright whiteness in beetle scale. The work here is an effect to further fabricate novel high-brightness optical composite films or coating materials for a variety of applications.