ABSTRACT
In this chapter, we review the experimental and theoretical research over the last 2 decades that has provided insights into the mechanisms involved in the gecko adhesion system. Theoretically models developed to explain the numerous properties of the gecko adhesion pads, including strong adhesion, anisotropic adhesion, self-cleaning, shear-induced adhesion, and adhesion under various environmental conditions and to surfaces of different roughness, are discussed. Experimental results from various research groups are also presented consistent with the theoretical analyses, e.g., the peel zone model, which predicts the adhesion force as a function of the peel angle and explains the anisotropic adhesion in geckos. Although researchers in field have managed to explain several of the unique properties of the gecko adhesion system, there still remain open questions, which need to be answered before fully understanding the gecko adhesion system. These answers will be crucial for researchers seeking to develop a true gecko-like dry adhesive.
