Abstract
Self-cleaning coatings have been developed for decades and lead to wide applications yet still limited by the expensive and complex processes. Inspired from the hydrophobicity of feather, we investigated the relation between the aligned structure and wettability of contour feathers. To go further, a facile two-step method was used to synthesize self-cleaning surfaces. The atmospheric pressure plasma (APP) technique was utilized to activate the surface and create hierarchical-structured metal-oxide coatings within a few seconds. The parameters of gas flow and coating time were evaluated and optimized. After silanization, the surfaces exhibited self-cleaning capability with low sliding angle and enhanced oleophobicity. Results indicated that all contour feathers were constructed by rachis, barbs and barbules. The terminals of barbules were hook-like shape, which could interlock with the adjacent barbules, forming the stable vane and maintaining fixed spacing. While the scale and spacing distance varied among species, leading to the difference in wettability and water resistance. APP-assisted nanoparticle deposition formed the hierarchical structure that enhanced the superhydrophobicity of the fluorinated surface. This method was also successfully applied on different substrates. In summary, we investigated the relation between hierarchical structure and wettability of feather, which could contribute to the micro-pattern design. We then developed a facile and cost- effective method to fabricate multifunctional, anti-wetting surfaces under atmospheric pressure and moderate temperature in short time, which could be applied to various substrates in different fields and overcome the limitations of current technologies.