A three‐dimensional multiscale finite element model describing the adhesion of a gecko seta

Abstract

A three‐dimensional multiscale model is presented which describes the adhesion and deformation of a gecko seta. The setae are micrometer fine hairs, covering the surface of the gecko toes, which enable the gecko to adhere to inclined and overhanging surfaces. The seta modeling is approached on three different length scales: At the top level, on the order of several micrometers, a finite element rod model is chosen to capture the branched microstructure of the gecko seta. At the intermediate level, on the order of several nanometers, a second finite element model is used to capture the detailed behavior of the seta tips, the so‐called spatulae. At the third level, on the order of Ångstroms, the adhesion forces between spatulae and substrate are modeled on the molecular level. The model allows for a detailed, yet efficient simulation of the mechanical seta behavior. A numerical relaxation technique is introduced to handle the jump‐off‐contact instability that can occur in pull‐off computations. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)