Cubic stress tensor sensor for robot skins

The purpose of this research is to produce a sensor chip that measures a stress tensor in an arbitrary point in an elastic body such as an artificial skin for a robot. The sensor consists of a cube-shaped rigid body and sub-sensors that measure normal stress on each corner of the cube. We explain the theory to decompose shear stress and non-uniform normal stress. Also, we fabricate a prototype sensor. The theory is examined by the prototype. The experimental results show that the sensor can measure the normal stress and the shear stress at once. Also, the results suggest that the sensor can measure the gradient of contact surface.