Failure mechanism transition of 3D-printed biomimetic sutures

Inspired by the biological sutures in nature, triangular suture specimens with different tooth tip angle and material combinations were fabricated via multi-material 3D printing. From mechanical experiments under uni-axial tension, two basic failure mechanisms were observed: tooth breakage and the cohesive failure of the interfacial layer. It was found that when the tooth tip angle increases and/or the strength of the material in the interfacial layer increases, the failure mechanism of sutures can transit from tooth breakage mode to the cohesive failure of the interfacial layer. To further understand the different failure mechanisms of sutures, advanced nonlinear finite element simulations were performed. The finite element models can predict both the overall load-displacement relation and the failure mechanisms of the 3D printed sutures.