A miniature triaxial tactile sensor with calibratatele readout circuit

Industrial robot needed touch sensor to enhance the accuracy of the assembly and fabrication. In this paper, we designed and fabricated a novel tri-axial capacitive tactile sensor which can detect normal force and shear forces, simultaneously. The sensor consisted of a polymer bump, MEMS membrane, and readout circuit. The element of the sensor had individual sensing electrodes and polymer bump which can reduce the other-axis effect and enhance the sensitivity. The readout circuit calibrated the gain and offset of the output signal which can improve the error by the manufacture. The width and height of fabricated element are 950μm and 760μm, respectively. The measured sensitivities of the sensor with the calibratable readout circuit are 159 and 135mV/mN for the normal and shear force, respectively. The maximum other axis effect is 8.6% in the detection of normal force.