Spark-erosion perforating technology was used to fabricate a Cu-based template characterized by pores with radius of 0.5 mm inclined at 75°. A commercial silicone elastomer of poly(dimethylsiloxane) (PDMS) with a...Spark-erosion perforating technology was used to fabricate a Cu-based template characterized by pores with radius of 0.5 mm inclined at 75°. A commercial silicone elastomer of poly(dimethylsiloxane) (PDMS) with a rich Si-H content was used to produce an inclined array of primary setae. The technique of argon ion plasma etching on crystalline silicon was used to fabricate negative templates with radii of 5, 10, and 20 μm. The Si-H rich PDMS was used to cast three types of fine array templates, which acted as the secondary setae. A vinyl-rich PDMS precursor was used to bind the primary and secondary setae by a hydrosilylation reaction, thus allowing the formation of three different hierarchical arrangements of setae. Adhesion tests demonstrated that shear adhesion was anisotropic, first increasing in strength then decreasing to a stable level as slippage occurred. The adhesion strength was significantly influenced by the nature of the secondary setae, showing a strong correlation with aspect-ratio and concentration.展开更多
基金supported by the National Natural Science Foundation of China (50805076, 60910007)Doctoral Fund of Ministry of Education of China (200802871043)Science Research Foundations of Nanjing University of Aeronautics & Astronautics (NS2010216, NS2012014)
文摘Spark-erosion perforating technology was used to fabricate a Cu-based template characterized by pores with radius of 0.5 mm inclined at 75°. A commercial silicone elastomer of poly(dimethylsiloxane) (PDMS) with a rich Si-H content was used to produce an inclined array of primary setae. The technique of argon ion plasma etching on crystalline silicon was used to fabricate negative templates with radii of 5, 10, and 20 μm. The Si-H rich PDMS was used to cast three types of fine array templates, which acted as the secondary setae. A vinyl-rich PDMS precursor was used to bind the primary and secondary setae by a hydrosilylation reaction, thus allowing the formation of three different hierarchical arrangements of setae. Adhesion tests demonstrated that shear adhesion was anisotropic, first increasing in strength then decreasing to a stable level as slippage occurred. The adhesion strength was significantly influenced by the nature of the secondary setae, showing a strong correlation with aspect-ratio and concentration.
