Effect of counterface roughness on adhesion of mushroom-shaped microstructure.
In this study, the effect of the substrate roughness on adhesion of mushroom-shaped microstructure was experimentally investigated. To do so, 12 substrates having different isotropic roughness were prepared from the same material by replicating topography of different surfaces. The pull-off forces generated by mushroom-shaped microstructure in contact with the tested substrates were measured and compared with the pull-off forces generated by a smooth reference. It was found that classical roughness parameters, such as average roughness (Ra) and others, cannot be used to explain topography-related variation in pull-off force. This has led us to the development of an integrated roughness parameter capable of explaining results of pull-off measurements. Using this parameter, we have also found that there is a critical roughness, above which neither smooth nor microstructured surface could generate any attachment force, which may have important implications on design of both adhesive and anti-adhesive surfaces.
Department of Mechanical Engineering, Technion, Haifa 32000, Israel. mehaytam@technion.ac.il
Haytam
H
Kasem
Michael
M
Varenberg
D000268:Adhesiveness; D004852:Epoxy Compounds / Q000737:chemistry*; D008422:Materials Testing; D055616:Microtechnology; D011145:Polyvinyls / Q000737:chemistry*; D012833:Siloxanes / Q000737:chemistry*; D013499:Surface Properties
D004852:Epoxy Compounds; D011145:Polyvinyls; D012833:Siloxanes; C034183:vinyl polysiloxane
attachment; biomimetics; fibrillar adhesives; pull-off force; surface topography