Design of bidirectional frictional behaviour for tactile contact using ellipsoidal asperity micro-textures

Abstract Tactile perception and friction can be modified by producing a deterministic surface topography. Change of feature arrangement texture symmetry produce an anisotropic frictional behaviour. It is generally achieved through skin hysteresis promoting its deformation. This work investigates whether bidirectional created with microscale ellipsoidal asperity textures, thus relying on the adhesive component friction. For this purpose, four textured samples various dimensions were moulded silicone rubber having elastic modulus comparable to that skin. Coefficient measurements conducted in-vivo in two sliding directions range normal loads up 4 N. Finite element method (FEM) was used study deformation effects, explain observed difference, predict material influence. Measurements performed perpendicular major radii showed consistently higher coefficients than during parallel sliding. larger dimensions, change direction increased factor 2. The numerical analysis effect mostly related deflection. Bidirectional differences further controlled spacing, properties.