In this paper, we propose a novel tactile sensor in which array of rigid elements is inserted to measure tangential force in addition to perpendicular force. The sensor structure is based on a tactile sensor using pressure sensitive rubber covered with elastic body and single-sided electrode sheet, which was developed in our previous study, in order to derive distribution of pressure magnitude. The principle is described, and two dimensional finite element analysis is carried out. Numerical results show that the perpendicular force and the tangential force can be derived simultaneously with the proposed sensor, and the effect of dimensions of the rigid element is discussed by both mechanical prediction and numerial results. A 3 × 3 unit-cell tactile sensor with pressure sensitive rubber and electrode sheet is prototyped, and experiments are undertaken using 6-axis force sensor as a reference. Experimental results having characteristics in dependence on tangential force and perpendicular force are compared with analytical results. The contributions of rigid element to sensor output is observed experimentally in agreement with simulations, and sensor properties are described.
