Fig. 5: Accuracy comparison of the grip strength under considering the 3D contact area or not.

When considering the 3D contact area, Fmon (Eq. (8)), the accuracy of the grip strength calculated from Eq. (8), is higher than that of not considering the 3D contact area from Eq. (1), namely Fmon (Eq. (1)). Accuracy improves 11.18% after considering 3D contact area. Details in Fig. S12 in supporting information.