Crack propagation and toughening mechanisms of bio-inspired artificial spicules fabricated by additive manufacturing technique

In this study, for the first time, we produced synthetic spicule-inspired structures (SISs) by 3D printing technology to improve both strength and toughness of brittle rigid resin. The SISs with 0.375 mm cylinder wall thickness without cores showed an improvement of 21%, 1450%, 6000% and 68% in flexural strength, strain, specific toughness and buckling stress (compared to the control samples), respectively. The Shear test results showed that SISs, provide a structure with better dispersing stress. Changing the architecture of solid rods to spiculic structures led to stopping and deflecting the crack path, and subsequently prevented catastrophic failure in these structures. Therefore, SISs can offer a novel and promising approach to increase the strength and flexibility of these brittle materials.