Modeling of contact mechanics with experimental results for soft fingers

A new theory in contact mechanics for modeling of soft fingers is proposed to define the relationship between normal force and area of contact for soft fingers by considering the soft finger materials as nonlinearly elastic. The results show that the radius of contact is proportional to the normal force raised to the power of γ which ranges from 0 to 1/3. This new theory subsumes the Hertzian contact model for linear elastic materials where γ = 1/3. Experiments are conducted to validate the theory using artificial soft fingers made of various materials such as rubber and silicone. This theory provides basis for constructing friction limit surface numerically. Combining the results of the contact mechanics model with the contact friction model the normalized friction limit surface is derived for anthropomorphic soft fingers.