Surface characterization and friction of a bio-inspired reversible adhesive tape

A polyvinylsilixane sample fabricated to replicate biological attachment systems consisting of microscale pillars (about 230/mm(2)) approximately 50 mu m in diameter, 70 mu m in height, and 60 mu m center-to-center was characterized for surface roughness, friction force, and contact angle and compared to an unstructured sample. Macroscale coefficient of kinetic friction of the structured sample was found to be almost four times greater than the unstructured sample. This increase was determined to be a result of the structured roughness of the sample and not the random nanoroughness. The structured roughness also increased the hydrophobicity of the structured sample, which is important for self cleaning to occur.