THE SKIN AND FRICTION: DEVIATIONS FROM AMONTON'S LAWS, AND THE EFFECTS OF HYDRATION AND LUBRICATION

SUMMARY.— The coefficient of friction has been determined for skin and various materials. It has been established that the behaviour of skin is not portrayed by the simple laws of friction, but by a more complex relationship of the type F =μWn. This is probably because skin is subject to viscoelastic rather than purely plastic deformation. Friction may be altered by the type of material in contact with skin and is further influenced by surface lubrication. Dry talcum powder reduces friction slightly for certain materials against skin, but increases friction when it becomes wetted.