A Flexible Hall Effect-Based Tactile Sensor With a Halbach Array

Human skin is highly sensitive to both normal and shear forces and can naturally decouple these two components. However, most existing robotic tactile sensors suffer from coupling between normal and shear forces, limited flexibility, and reliance on complex decoupling algorithms. To overcome these limitations, we proposed a tactile sensor base on magnetic principle. The sensor features a compact structure and flexibility. A circular magnetic film on the top is magnetized in a Halbach array, enabling the detection of both normal and shear forces while providing excellent self-decoupling capability. By adjusting the parameters of the elastomer layer, the measurement range and sensitivity can be tuned for various applications. Furthermore, calibration experiments demonstrate that the proposed sensor with the normal force exhibiting good linearity from 0 N to 15 N (fitting error 3.27%) and the shear force in the 0 N to 5 N range closely matching the theoretical curve (fitting error 3.52%). Grasping experiments further verify its effectiveness in detecting surface roughness and assisting force control in robotic grasping. These results suggest that the proposed sensor holds significant potential for applications in robotic grasping and tactile perception.