Enhancing the Detection Sensitivity in Capacitive Tactile Sensors With Optimized Electrode Shapes

This work evaluated several electrode designs in a capacitive tactile sensor (CTS) to provide an optimized solution that shows the maximized sensitivity in shear force detection. In addition to shear angle derivation procedure, identical overlapping areas between the paired electrodes in capacitors were assigned for fair comparison on detection sensitivity of normal force. The theoretical calculation, numerical simulation, practical fabrication, analysis, and discussion were comprehensively conducted in this work with a typical CTS that showed square electrodes as a reference. Results indicated that when the number of legs in a polygon electrode is small, the detection sensitivity in shear force application is high. Furthermore, because the operating principle was unaltered, all designs exhibited compatible detection capability on shear angle in terms of resolution and accuracy. Although only two extreme cases of CTSs with triangular and circular electrodes were demonstrated as proofs-of-concept in this work, the universal solution is also eligible to other designs with polygon electrodes.