Abstract: To imitate the structure of nonsmooth surface of earthworm and the wearresistance performance caused by its body secrete, experiments with mixing lubrication of oil dripping were performed on a friction test bench on three bionic nonsmooth surfaces: hollow pit surface, throughhole surface with leading angle, and throughhole surface, which are similar to the body surface of earthworm. Results show that the nonsmooth surface with throughhole, which is most similar to the back surface of earthworm, possesses the best lubrication and wearresistance characteristics. The mechanism of the influence of bionic nonsmooth surface on the wearresistance was analyzed. It was found that proper designs of the hole geometry and the distribution of holes on the surface can effectively improve the wear performance.

Key words: bionics engineering, nonsmooth surface, wear, lubrication, earthworm