Sensor design and calibration of piezoresistive composite material

In this paper we outline the design of a tactile sensor suitable for force calibration. The sensor is composed of piezoresistive composite material, sandwiched between two electrodes and arranged as sensor array. This sensor design allows to cover large surfaces with tactile perception, for example, as tactile robot skin. However, inhomogeneity as a result of randomly dispersed conductive filler in the polymer and unknown pressure areas have prevented this sensor material to be calibrated properly until now. We present an appropriate sensor design, successfully demonstrating force calibration of large sensor cells. Drift correction based on the Voigt-model increases the accuracy of the sensor. Finally, experiments with a 2×2 calibrated sensor array prove the reliability of the force sensor.