The Relationship between Superhydrophobicity, Self-Cleaning Performance and Microstructure of Moth Wing

The microstructure and superhydrophobicity of the moth wing surfaces were investigated by a scanning electron microscope (SEM), an atomic force microscope (AFM) and a contact angle (CA) meter. The relationship between superhydrophobicity, self-cleaning performance and microstructural characteristic was discussed. The wing surface is of low adhesion (sliding angle 1~4°) and high hydrophobicity (CA 151~158°). The removal rate of CaCO3 pollution from the wing surface is as high as 86.7%. There is a good positive correlation (R 2 =0.8883) between pollution removal rate and roughness index of the wing surface. The coupling effects of hydrophobic material and rough microstructure contribute to the complex wettability and remarkable self-cleaning property of the wing surface. Moth wing can be used as a template for design of micro-controllable superhydrophobic surface and nano self-cleaning material. This work may offer inspirations for preparation of novel interfacial material with multi-functions.