Abstract
The microstructure investigated in this study was inspired by the anisotropic microornamentation of scales from the ventral body side of the California King Snake (Lampropeltis getula californiae). Frictional properties of snake-inspired microstructured polymer surface (SIMPS) made of epoxy resin were characterised in contact with a smooth glass ball by a microtribometer in two perpendicular directions. The SIMPS exhibited a considerable frictional anisotropy: Frictional coefficients measured along the microstructure were about 33% lower than those measured in the opposite direction. Frictional coefficients were compared to those obtained on other types of surface microstructure: (i) smooth ones, (ii) rough ones, and (iii) ones with periodic groove-like microstructures of different dimensions. The results demonstrate the existence of a common pattern of interaction between two general effects that influence friction: (1) molecular interaction depending on real contact area and (2) the mechanical interlocking of both contacting surfaces. The strongest reduction of the frictional coefficient, compared to the smooth reference surface, was observed at a medium range of surface structure dimensions suggesting a trade-off between these two effects.
Highlights
Owing to the lack of extremities, the ventral body side of snakes is in almost continuous contact with the substrate
The angle in the direction of the measurement along the snake-inspired microstructured polymer surface (SIMPS)’ microstructure is 47°, in the opposite direction 62°, and in lateral direction 55° (Table 2, Figure 2a).The quality of the moulded polymer surfaces was inspected by scanning electron microscope (SEM) and atomic force microscopy (AFM) (Figure 3)
SIMPS demonstrated a considerable reduction of the frictional coefficient, if compared to the same polymer with smooth surface
Summary
Owing to the lack of extremities, the ventral body side of snakes is in almost continuous contact with the substrate. The measurements perpendicular to the orientation of the microstructure with structural wavelength dimensions of 25 μm, 50 μm, and 100 μm revealed a lower frictional coefficient, if compared to the smooth polymer surface.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
