Phase component of spearer propodus out layer of mantis shrimp

Effects of microstructure and phase component on mechanical property of spearerpropodus of mantis shrimp were investigated. The spearer propodus consisted ofthree layers including epicuticle (outer layer), exocuticle (middle layer), and endo-cuticle (inner layer). The outer layer was composed of fluorapatite, which was treatedas permeability barrier to environment. The compact middle layer and inner layerwere constituted of chitin-protein fibers, which exhibited the layered spiral structure.Under the in-situ tensile test environment, spearer propodus owned high mechanicalstrength, which bore maximum tensile fore of 320 N. In the in-situ tensile process,cracks extended along with zigzag lines on spearer propodus surface. The middlelayer and inner layer resisted the damage of force via the fracture and pulling offibers. The crack deflection and delamination phenomena were the mechanical prop-erty mechanisms of spearer propodus of mantis shrimp. The investigations providedtypical bionic models for the design and preparation of bionic structure materials,bionic anti-impact materials, and bionic soft materials in engineering fields.