Multi-Scale Investigation of Surface Topography of Ball Python']Python (Python']Python regius) Shed Skin in Comparison to Human Skin

A major concern in designing tribosystems is to minimize friction, save energy, and to reduce wear. Conventional philosophy for design centers on mechanical and material considerations. In particular, designers pay more attention to material properties and material choices based on mechanical properties rather than the design and shape of the contacting surfaces and the relation of that surface to the function of the device. As a result of thriving for miniaturization, focus has shifted toward optimal surface design (that is to construct a surface that is an integral part of the function of the tribosystem). Inspirations for such a trend come from studying natural systems and mimicking natural design rules. The major attraction is that natural systems, while functionally complex, are, in general, of optimized shape and performance. It is further believed that functional complexity of natural systems is what affords natural species to morph continuously to adapt with the operating environment. One bio-species that is of interest is the Ball Python. This is because such a species continuously slides against various surfaces, many of which are deemed tribologically hostile, without sustaining much damage. Much of the success of that species in adapting to its environment is attributed to surface design features. In that respect, studying these features and how do they contribute to the control of friction and wear is very attractive. This paper is a step in this direction. In this work we apply a multi-scale surface characterization approach to study surface design features of the Python regius. The focus is on those features that are typically used to assess the performance of high quality lubricating surfaces (such as those obtained through plateau honing). To this end, topographical features are studied by SEM and through White Light Interferometry (WLI). We probe the roughness of the surface on multi-scale and as a function of location within the body. In addition we draw a comparison of these features to those of human skin.