Adhesion and Friction Properties of Plant Surfaces with Typical Architectures in Different Humidity Conditions

Yujuan WANG
2017 Journal of Mechanical Engineering  
Abstract:Colloidal probes, based on the high precision of atomic force microscope (AFM), are employed to measure the adhesion and friction of original plant surfaces characterized with four typical architectures (smooth two-dimensional wax layers, low cuticular folds, high cuticular folds, three-dimensional wax crystals) and two plant surfaces exposed to chloroform in dry and various humidity environments. The results show that the surface energy and hydrophilicity of holly leaves are reduced
more » ... eaves are reduced by their smooth two-dimensional wax layers, which could not only lower the friction and adhesion between the colloidal probe and plant surfaces under dry conditions, but also prevent the formation of capillary bridges in ambient air with a low humidity, thus enhancing the desorption capability. The surface structure of Litchi leaves with low cuticular folds increases the gap between two interactive surfaces, against the formation of capillary bridges by the vapor condensation. As a consequence, the anti-adhesion performance of their surfaces is improved and better than that of two-dimensional wax layers in a wide range of humidity conditions. Water vapor around contact areas is excluded by cyclamen persicum leaves with high cuticular folds and nepenthes surfaces with three-dimensional wax crystals, making them possess a strong anti-adhesion capacity either in dry or high humidity ambient air. The coupling of three-dimensional architecture and wax crystals with low surface energy keeps the slippery surface of nepenthes presenting a better anti-adhesion effect than that of cyclamen persicum leaves with high cuticular folds. The results above provide a theoretical foundation for the design and preparation of bionic anti-adhesion surfaces. Key words:colloidal probe;humidity;adhesion;friction;typical architecture 月 2017 年 11 月 王玉娟等:典型构筑植物表面不同湿度条件下黏附和摩擦特性研究 87
doi:10.3901/jme.2017.21.086 fatcat:oopbmvkxgzcj7exsntq3el63ye