Design, simulation and fabrication of a low cost capacitive tactile shear sensor for a robotic hand

In this paper a novel shear sensor design is described. The proposed design is able to measure static shear forces. The sensor is fabricated on a printed circuit board and uses a differential capacitor arrangement to detect shear force applied to the sensor surface. Both mathematical and COMSOL models have been developed for the described sensor. The sensor is intended for use in robotic hands for the detection of shear force at the tactile interface. The device can be fabricated at a low cost in both low and high volumes. Prototype sensors with a +/-0.525 mm displacement range were fabricated. Fixed displacements (over the range +/-0.5 mm) are applied to the capacitor common plate, without a silicone covering, and a range of shear forces (over the range +/-4 N) applied to the sensor, once covered with a silicone skin, and the differential capacitance of the transducer is recorded. The maximum standard deviation of the differential capacitance across all force values is 1.35e-15 F. The maximum standard deviation, at each force value, across a range of +/-2 N is 4.28e-16 F.