Fig. 5. Force generation by the beetle on different textures. (A) Surface texture of sandpaper types (12 µm, P400 and P280). R_a, surface roughness; R_z, average height of surface irregularities. (B) Comparison of the claw tip dimensions with the sandpaper texture (12 µm type) (above: side view, below: top view). (C) An example of the typical force recording used for data processing. (D) Forces generated by beetles walking on different substrate textures. When the diameter of particles is comparable with the claw tip, the claw slips out of the particle. When the diameter of the particles is larger than that of the claw tip, the claw is interlocked with the particles.