Fig. 8. Experimental climbing machine, `Stickybot' (A), for testing anisotropic adhesive structures and force control strategies. Inset (B) shows experimental measurements of normal vs shear forces in an anisotropic frictional adhesive inspired by gecko setae. We used the same methods as for isolated gecko setal arrays. The urethane microarrays demonstrated a similar frictional adhesion response to that of gecko setae (Fig. 3D). Data were taken on a patch with an area of 35 mm². The area of each Stickybot toe is 431 mm² (C) Magnified view showing angled contact surface of frictional adhesive microarray.