It is found that typical desert organisms such as desert scorpion have excellent erosion resistance and cross-scale structural coupling rules under the dynamic action of heterogeneous mixed media. The influence mechanism of surface morphology, cross-scale structure and flexibility on the erosion resistance of desert scorpion were revealed.

Desert scorpion survive in the desert environment where wind-sand erosion occurs frequently. Through long-term natural selection and evolution, the variation unfavorable to wind-sand erosion was gradually eliminated and the variation favorable to wind-sand erosion was gradually accumulated. The back plate of desert scorpion has millimeter arc structure, convex hull and groove on the surface, flexible nodal membrane between the back plate, flexible side membrane between the back plate and the web, and chitin micron convex array structure on the back plate. These multi-factors combined with multi-scale structure and morphology make desert scorpion have excellent erosion resistance.

Figure 1 Living scorpion and its body surface structures. (a) Living scorpion, (b) Bump, (c) Grooved nodal membrane, (d) Flexible lateral membrane

As shown in figure 2, through systematic experimental study, scorpion body surface erosion resistance principle is the result of multi-factor and multi-element coupling synergistic effect, which can be divided into the following three mechanisms. 1. The effect of surface morphology and configuration: under the effect of different surface morphology (groove, convex hull and curved surface) of scorpion, the impact angle and relative velocity of impact particles and material surface change due to the surface of different morphology and matrix surface are at a certain angle. At the same time, vortices are formed in the grooves, which further reduce the velocity of the impact particles and reduce the number of the particles hit the material surface. 2. The function of flexible connection: there is a flexible membrane on the surface of scorpion, which can reduce the maximum impact force of impact particles, extend the impact time and absorb part of the impact energy. 3, The role of ductile materials: chitin film of scorpion body surface is a good toughness material, the improvement of material toughness can effectively reduce the plow and shovel cut damage of impact particles. Under the coupling effect of the above three factors, scorpion body surface has excellent erosion resistance.