Three-dimensional modeling and simulation of the sliding motion of a soft fingertip with friction, focusing on stick-slip transition

We have proposed a dynamic model to investigate the sliding motion of a 3-dimensional soft fingertip on a plane with friction. The fingertip is comprised virtually of a finite number of elastic compressible and bendable cantilevers whose free ends act as infinitesimal contact points. The contact surface is afterward meshed using finite element method based on coordinates of contact points. By introducing Coulomb´s law and contact compliance into each contact point, we are able to assess the frictional characteristic during sliding motions of the fingertip. We also successfully described dynamically localized displacements on the contact surface during stick slip transition, which occurs substantially on hemispherical soft fingertip. Moreover, each simulation trial was implemented in a very small amount of time comparing to commercial softwares, promising use of this model in realtime application In addition, we conducted experiments to valid proposed simulation, including force/moment and vision setups.