Fig. 1. The principle of shear force perception

Fig. 2. Apply shear forces along the y-direction at different areas

Fig. 3. Strain at different depths during sliding process

Fig. 4. Strain at different depths under pressure

Fig. 5. 3D structure and top view of sensor

Fig. 6. Sliding detection experimental device

Fig. 7. Sensitivity calibration of pressure and shear force

Fig. 8. Wavelength shift in different sliding directions

Fig. 9. Confusion matrix for SVM recognition of sliding direction

Fig. 10. The structure of 1D-CNN network

Fig. 11. The parameter optimization process of 1D-CNN network