Beam bundle model of human-like fingertip for investigation of tactile mechanism

We have proposed a Beam Bundle Model for modeling of a human fingertip during pushing and sliding action with friction, especially stick-to-slip transition, to overcome mentioned issues. In order to construct its three-dimensional non-homogeneous structure, we took sequence of magnetic resonant images, which bring consecutive cross-sectional layers of the human fingertip with distribution of skin, tissue, bone, and nail. Simulation results show a twofold aspect. Firstly, it can generate not only normal force distribution caused by pushing, but also response of friction force during sliding. Secondly, and more interestingly, the model dynamically produces localized displacement phenomenon on the contact area during stick-to-slip phase, which indicates how slippage erodes the contact area before the total slippage of the fingertip occurs. Finally, we investigated role of sliding mechanism acting on human fingertips' contact area in stable lifting of an object, in order to show the potential of the model in studying tactile mechanism of human and apply to robotic systems.