Investigations on anisotropic frictional response on different types of shed snake’s skin

Optimisation of the texture and topography of surfaces which undergo rubbing or sliding plays a decisive role in minimizing frictional losses in a mechanical system. Furthermore, the incorporation of the ability to exhibit varying frictional behaviour along different directions in surfaces can prove to be especially beneficial in mechanical systems possessing more than one degree of freedom. Nature along with evolution has successfully provided such a surface structure in squamate reptiles. This research is aimed at observing the microstructure of the snake skin shed through Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM), and studying the frictional response of shed skins of three indigenous snake species namely, Ophiophagus hannah, Ptyas mucosa and Python molurus. This paper also establishes a connection between the frictional behaviour and micro-structure in the snakes. The results confirm the presence of anisotropic friction in the ventral scales of snakes.