Characterization of load bearing metrological parameters in reptilian   exuviae in comparison to precision finished cylinder liner surfaces
  Design of precise functional surfaces is essential for many future applications. In the technological realm, the accumulated experience with the construction of such surfaces is not sufficient. Nature provides many examples of dynamic surfaces worthy of study and adoption, at least as a concept, within human engineering. In this work, we probe load-bearing features of the ventral skin of snake surfaces. We examine the structure of two snake species that mainly move by rectilinear locomotion. These are Python regius (pythonidae) and Bittis gabonica (Vipridae). To this end, we focus on the load bearing characteristics of the ventral skin surface (i.e. the Rk family of parameters). Therefore, we draw detailed comparison between the reptilian surfaces and two sets of technological data. The first set pertains to an actual commercial cylinder liner, whereas, the second set is a summary of recommended surface finish metrological values for several commercial cylinder liner manufacturers. The results highlight several similarities between the two types of surfaces. In particular, we show that there is a striking correspondence between the sense of texture engineering within both surfaces (although that their construction evolved along entirely different paths). We also show that reptilian surfaces manifest a high degree of specialization with respect to habitat constraints on wear resistance and adhesive effects. 
H. A. Abdel-Aal, M. El Mansori
physics.bio-ph