Towards a micromechanical understanding of biological surface devices

Interesting analogies exist between the science of materials in small dimensions and the mechanics of biological systems. In both instances, mechanical forces and displacements are measured and the results are interpreted in the light of theoretical expectations. The approaches are, however, fundamentally different: consideration of structural diversity and global performance in biology contrasts with more quantitative evaluation of local properties and emphasis on micromechanical modeling in materials science. We report on two examples of our first efforts to combine these approaches in the investigation of biological attachment systems in insects. Nanoindentation studies were performed on the head-neck joint and the wing-locking mechanism in a beetle, and the foot-substrate adhesion in flies and geckos has been examined from the perspective of theoretical contact mechanics. By aiming at a quantitative understanding of the interrelationship between local material properties and complex structures, such studies may lead to the design of artificial attachment systems which are potentially useful in micro-technology.