Biomimetic bamboo leaf double-sided microstructure composite surface and its delayed icing performance

Abstract

The frost phenomenon occurred on the surface of engineering equipment can not only lead to a reduction in the efficiency of equipment but a higher energy consumption. How to effectively inhibit or delay the frost behavior on a material surface and improve the anti-frost property on the surface is of great importance. It is found that the nano needle structure on the surface of bamboo leaves can provide large Laplace pressure to drive droplets to bounce and hence delay the condensation process. In addition, in the frost crystal growth stage, the nano needle structure can reduce the contact area between droplets and the surface of bamboo leaves, and hence limit the phase-change heat transfer of water vapor and increase the thermodynamic barrier when nucleation of water vapor occurs, thereby delaying the frost crystal growth. In this paper, inspired by bamboo leaves, biomimetic structures are constructed on the surface of an aluminum alloy by laser processing and sol-gel method. Results reveal that delayed frost formation on the surface is realized, which is of immense practical value in engineering and many other aspects.