Influence of the finger inclination on its frictional interaction with micro-textured surfaces

Tribology of touch is a subject of high interest, which has led to a certain number of experimental studies, each of them done under different contact conditions. The present paper aims at determining, in the case of the friction of the finger on four different micro-textured surfaces, the influence of the normal force and the inclination of the finger. The experiments were done with four target angles and two target forces, all at the same contact speed. The friction coefficient was shown to decrease when the finger was tilted upwards, for the four surfaces and for both normal force conditions. A friction law has been then fitted to the experimental results, trying to bring further insights on the experimental observations.