Calibrations on Shear Angle Detections in Vertically Stacked Capacitive Tactile Sensors

Four factors that contribute to shear angle derivation tolerances in a vertically stacked capacitive tactile sensor with the highest detection sensitivity were thoroughly studied. The fringe effect that appears in a sensing array was found as an environmental factor contributing to the tolerance (0.031°); the torsional deformation that appears in the electrode was found as a structural factor contributing to the tolerance (0.011°); the torque-induced deformation generated from the bump was found as an applicational factor contributing to the tolerance (0.087°); and the asymmetrical stress distribution in the elastomeric dielectric was found as an operational factor contributing to the tolerance (− 0.968°). The effects of these factors were neglected in previous related studies. This paper provides a calibration solution for each case. Additionally, tolerances projected from the contributions of these factors under different conditions are provided with high coefficients of determination based on corresponding regressions. This paper provides scientific and quantified tolerances for verifying the derived shear angle when accurate detection is desired.