The effect of integrating a bio-inspired convex structure with a low-surface energy polymer on soil adhesion and friction

The capacity of soil-burrowing animals to move freely in sticky soil is a motivational trait for developing soil-engaging tools with high operational efficiency. Meanwhile, outstanding hydrophobicity, chemical stability, and corrosion resistance make ultra-high molecular weight polyethylene (UHMW-PE) a potential option for reducing soil adhesion. This study looked into the viability of combining a domed surface inspired by the micro-convex structure of the dung beetle skin with the UHMW-PE as a surface coating to reduce sliding resistance. The sliding resistances of three plates (a flat plate of carbon steel, a flat plate of UHMW-PE, and a domed plate of UHMW-PE) were assessed under varied operating and soil conditions. In each treatment, the tested plate was dragged for 0.7 m of the soil bin length, and the sliding resistance was recorded using the distributed stress and strain test and analysis system (DH3820 N). The results revealed that in all treatments, the sliding resistance of the UHMW-PE domed plate was significantly lower than that of the flat steel plate. Furthermore, the UHMW-PE domed plate outperformed the other tested plates in reducing sliding resistance in more moist and sticky soils, paving the way for the development of highly practical and effective soil-engaging tools.