title: Effect of stiffness of multi-level hierarchical attachment system on adhesion enhancement.
abstract: Geckos are known for their remarkable ability to cling on and detach from ceilings and walls using a unique attachment system. Their foot pads are covered by a large number of small hair (setae) that contain many branches per seta with a lower level of spatulae. This hierarchical structure gives the gecko adaptability to create a large real area of contact with rough surfaces. In this study, using the three-level hierarchical model recently developed to simulate a gecko seta contacting with random rough surface, the effects of spring stiffness and number of springs on the adhesion enhancement of multi-level hierarchical model are investigated. One- and three-level hierarchically structured spring models with different spring stiffnesses and number of springs on each level in contact with various rough surfaces are considered. The efficiency of attachment-the adhesion coefficient, the adhesion force, the number of contacts and the adhesion energy-for the three-level models with different stiffness is investigated in contact with different rough surfaces.
authors.affiliation: Nanotribology Laboratory for Information Storage and MEMS/NEMS, The Ohio State University, 201 W. 19th Avenue, Columbus, OH 43210-1142, USA.
authors.forename: Tae Wan
authors.initials: TW
authors.lastname: Kim
authors.forename: Bharat
authors.initials: B
authors.lastname: Bhushan
mesh_terms: D000268:Adhesiveness; D000818:Animals; D005528:Foot / Q000502:physiology*; D008116:Lizards / Q000502:physiology*; D008954:Models, Biological