An experimental study on the relation between surface texture and tactile friction

The main obstacle to calculate the ‘feel’ of a product from its surface properties is the ill-defined surface topography that is encountered after the most surface finishing processes. In this work this obstacle was avoided by producing well-defined surface topographies by laser texturing. The friction of textures having surface features with varying radii and spacings was investigated by measuring friction against the fingerpad. Within the range of conditions tested the coefficient of friction decreased with increasing normal load. The relation between the surface texture parameters and the coefficient of friction is influenced by the scale-dependent elastic behaviour of the skin top layer.

► The friction of textured surfaces sliding against the finger decreases strongly with normal load.
► Adhesion is the dominant friction mechanism.
► The friction increases with a factor two with increasing skin hydration.
► Varying the asperity radius and spacing does not influence friction.
► Laser texturing is a useful technique for producing well-defined surface textures.