Tactile perception is a largely subjective experience, due to individual differences in semantic interpretation, skin hydration, receptor density, and mechanical properties of the skin. Characterisation of roughness, elasticity, adhesion, and tactile friction, for example, is invaluable to obtaining a quantitative description of the tactile character of surfaces. Roughness often dominates, but, because they are intimately related, tactile friction and roughness also work in concert to create differing experiences [1]. All else being constant, when roughness is small or similar between surfaces, tactile friction is the dominant cue for discrimination [2]. Changing the properties of ...