An Angle-Sensitive Microcolumn-Based Capacitive Shear Force Sensor for Robot Grasping

Shear force sensors play an indispensable role in tactile perception for robot manipulation tasks. However, recent advancements in shear force sensors have been hindered by issues such as direction sensitivity and integration limitations. This paper proposes a microcolumn array dielectric layer produced using photolithography technology that enables tunability of sensor sensitivity and detection range by adjusting the aspect ratio and interval of the microstructures. Meanwhile, the impact of five constant normal force couplings on the sensitivity of shear force perception is investigated. The structure array with a 1:2 aspect ratio and 600 mu m interval demonstrates an ultrahigh sensitivity of 6.189 N-1 and outstanding linearity (R2 = 0.9873) within the range up to 0.1 N. The sensor exhibits low hysteresis and robust stability over 3000 cycles. Additionally, it exhibits remarkable anisotropic direction sensitivity, enabling accurate positioning within a quarter-circle angle. An intentionally designed orthogonal array is employed to extend the shear angle range up to 360 degrees. Owing to the high performance of the sensor, it is further integrated onto a gripper to facilitate the grasping operation and effectively capture delicate movements. The experimental outcomes highlight that the designed sensor holds promise for applications in robotic applications and electronic skin domains. A capacitive shear force sensor based on microcolumns dielectric layer with a 1:2 aspect ratio and 600 mu m interval realizes ultrahigh anisotropic sensitivity to shear forces from different directions. The single sensor achieves a shear range of 90 degrees, and the range can be further expanded to 360 degrees via orthogonal sensor array. Additionally, the sensor successfully monitors robot grasping. image