Hydrophobicity mechanism of non-smooth pattern on surface of butterfly wing

Twenty-nine species (24 genera, 6 families) of butterflies typical and common in northeast China were selected to make qualitative and quantitative studies on the pattern, hydrophobicity and hydrophobicity mechanism by means of scanning electron microscopy and contact angle measuring system. The scale surface is composed of submicro-class vertical gibbosities and horizontal links. The distance of scale is 48-91 mu m, length 65-150 mu m, and width 35-70 mu m. The distance of submicro-class vertical gibbosities on scale is 1.06-2.74 mu m, height 200-900 nm, and width 200-840 nm. The better hydrophobicity on the surface of butterfly wing (static contact angle 136.3 degrees-156.6 degrees) is contributed to the co-effects of micro-class scale and submicro-class vertical gibbosities on the wing surface. The Cassie equation was revised, and new mathematical models and equations were established.