Artificial finger skin having ridges and distributed tactile sensors used for grasp force control

An artificial elastic finger skin for robot fingers was developed for controlling the grasp force when the weight and friction coefficient of the grasped object are unknown. The elastic finger skin has ridges at the surface to divide the stick/slip area. It also has a pair of tactile sensors embedded per one ridge similar to human fingertips. The surface of the whole finger is curved so that the reaction force can be distributed. A finite element (FE) model of the elastic finger skin was developed to perform a dynamic contact analysis using the FE method in order to design the elastic finger skin. The elastic finger skin was then constructed. It was confirmed by calculation and experiment that the incipient slippage of the ridge that occurs near the edge of contact area can be detected. This result is useful for controlling the grasping force when the weight and friction coefficient between the elastic finger skin and grasping object are unknown