Insights from studies of gecko-inspired adhesion and their impact on our understanding of the evolution of the gekkotan adhesive system

The recent increase in interest about gekkotan adhesion, motivated at least in part by attempts to co-opt its principles and design features for human applications, has led to new ways of exploring the long-standing issue of how such a phenomenon might have evolved. The Gekkota is a highly speciose group, and one in which an adhesive apparatus has evolved independently on numerous occasions, capitalizing in each case upon common features of the integument that provide the basis for integrating the elaboration of microfibrillar arrays with morphological characteristics that promote the establishment and easy release of an adhesive bond. The explosion of knowledge about the phenomenon of adhesion at the nano-scale permits a new synthesis of how such a system functions in natural environments, and how it might have been acquired in the first place. In this summary we outline promising new lines of inquiry that have emerged from recent discoveries. These relate to aspects of the configuration and mechanical operation of setal fields and the patterns of expression of microfibrillar structures of varying dimensions and configurations; the means by which setal form and disposition promote attachment to and detachment from surfaces with minimal energy expenditure; and the real-world capabilities of the gekkotan adhesive system in the context of roughness, undulance and attachment potential at the scale of the setal fields. It is advocated that applied and curiosity-driven research can be reciprocally illuminating, and that the results of applied research can provide important insights that drive evolutionary thinking.