Review of the frictional properties of finger-object contact when gripping

Gripping is an everyday task which is taken for granted by many. The current paper examines extant knowledge of how objects are gripped for manipulation, and the relationship, the coefficient of friction, between finger and object, has on various grip parameters. It is found that friction is an essential part of the feedback and feedforward control system for grip. The friction of the finger-object contact can be measured in several different ways, using methods of either a probe moving on a finger or a finger moving on a flat surface. These friction measurements can then be used to gain information about the effect of normal force, sliding speed, contact area, and level of moisture present. They also can provide information about the changes between test subjects, for example, the effects of age, gender, and race. Knowing the effect of these parameters can help to improve the manoeuvrability of everyday items through inclusive design; designing products to be used by the whole population regardless of age or ability. The current paper also suggests areas of further investigation so that knowledge of skin friction can be expanded and applied to a larger range of materials and applications.