三轴力解耦测量的高灵敏触觉传感器

Traditional capacitive tactile sensors have much lower sensitivity in the direction of shear force than in that in the normal direction owing to the existence of coupling measurement of signals. To resolve this issue, a highly sensitive tactile sensor, with triaxial force decoupling measurements was designed based on multilayer capacitor structure. The sensor comprised of measuring units for both the shear force and normal directions. The measuring unit for the shear force direction adopted differential finger elements with symmetric distribution to achieve highly sensitive measurements. The structure of an ultra-thin elastic silicone dielectric was adopted to improve the effective compression stiffness of the shear dielectric layer, thereby restraining the coupling interference from the normal direction. The measuring unit for the normal direction useed a sparse of elastic mesh microstructure as the dielectric to achieve highly sensitive measurements. The coupling interference from the direction of the shear force was restrained by extending the normal grounding electrode. The tactile sensor was manufactured based on the parametric design of the capacitor structure. Furthermore, a triaxial force system was built to test the sensor. The test results show that the sensitivity in the shear X and Y and normal directions are 0.206 pF/N, 0.251 pF/N, and 0.148 pF/N, respectively. Additionally, the maximum static coupling ratios between the shear X and Y directions and that between the shear and normal directions are 7.636% and 1.051%, respectively. The proposed sensor achieves decoupling measurement of the triaxial force and maintains the same level of high sensitivity in the shear force and normal directions.