title: Enhanced adhesion by gecko-inspired hierarchical fibrillar adhesives.
abstract: The complex structures that allow geckos to repeatably adhere to surfaces consist of multilevel branching fibers with specialized tips. We present a novel technique for fabricating similar multilevel structures from polymer materials and demonstrate the fabrication of arrays of two- and three-level structures, wherein each level terminates in flat mushroom-type tips. Adhesion experiments are conducted on two-level fiber arrays on a 12-mm-diameter glass hemisphere, which exhibit both increased adhesion and interface toughness over one-level fiber samples and unstructured control samples. These adhesion enhancements are the result of increased surface conformation as well as increased extension during detachment.
authors.affiliation: Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213-3890, USA. mikemurphy@cmu.edu
authors.forename: Michael P
authors.initials: MP
authors.lastname: Murphy
authors.forename: Seok
authors.initials: S
authors.lastname: Kim
authors.forename: Metin
authors.initials: M
authors.lastname: Sitti
mesh_terms: D000268:Adhesiveness; D000269:Adhesives / Q000737:chemistry*; D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D008116:Lizards / Q000378:metabolism*; D008422:Materials Testing; D011140:Polyurethanes / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000269:Adhesives; D011140:Polyurethanes