AVS 53rd International Symposium
    MEMS and NEMS Tuesday Sessions
       Session MN-TuP

Paper MN-TuP9
The Adhesion Analysis of Multi Layered Hierarchical Structure of Gecko Feet

Tuesday, November 14, 2006, 6:00 pm, Room 3rd Floor Lobby

Session: Aspects of MEMS and NEMS Poster Session
Presenter: T.W. Kim, The Ohio State University
Authors: T.W. Kim, The Ohio State University
B. Bhushan, The Ohio State University
Correspondent: Click to Email
Several creatures including insects, spiders, and lizards, have a unique ability to cling on ceiling and wall that utilizes dry adhesion. Geckos, in particular, have developed the most complex adhesive structures capable of smart adhesionâ?"the ability to cling on different smooth and rough surfaces and detach at will. The gecko feet are comprised of a complex fibrillar structure of ridges called lamellae that are covered in microscale setae that branch off into branches with nanoscale spatulae. This hierarchical structure enables the gecko the adaptability to create a large real area of contact with rough surfaces. van der Waals attraction between the large numbers of spatulae in contact with rough surface is responsible for high adhesion. In order to investigate the effect of geckoâ?Ts hierarchical structure, we consider single and multi layered hierarchically structured spring models for simulation of seta contacting with random rough surfaces. Single contact (spatula) was assumed as spherical. Rough surfaces with various roughness parameters are generated, which is a common range of most of natural and artificial rough surfaces at the scale size of gecko seta. The simulation results show that multi layered hierarchy structure has higher adhesive force than single hierarchy structure, due to better adaptation and attachment ability.