Jigsaw Pattern Infills Inspired by Toughening Mechanisms of Diabolical Ironclad Beetle for 3D Printing Technologies

Abstract The Jigsaw puzzle‐like biological shape of the diabolical ironclad beetle, renowned for exceptional toughness due to interlocking and laminated blade geometries, serves as inspiration for advanced infill designs in fused filament fabrication (FFF) 3D printing. Thus, a biomimetic Jigsaw pattern infill is developed to mitigate the structural failure typically observed in conventional infill under mechanical loads. Through experimental and computational analyses, the biomimetic features of the Jigsaw pattern infills have been verified. Additionally, central composite design statistics are conducted to identify comprehensive trends in design and 3D printing parameters. The synergetic effects of the infills with continuous carbon fiber reinforcement (CCFR) in 3D printing have been investigated. The Jigsaw infill minimizes mechanical strength losses caused by variability in infill density and extrusion flow rate, outperforming conventional infills. Moreover, specimens with Jigsaw infills (ASTM D790) achieve a flexural strength of 338.9 MPa at a carbon fiber volume fraction of 23.58%, surpassing that of specimens with line‐based solid infill (305.5 MPa at 32.16%). Jigsaw infills with CCFR have been intuitively demonstrated through 3D printed carjack applications, which reliably endure loads of up to 1089 kg. These features highlight the potential for lightweight structural applications in the automotive and robotic industries.