Nature-inspired interlaced printing strategies for additive manufacturing highly improved mechanical properties

Abstract

In conventional additive manufacturing, the layer-by-layer approach leads to mechanical weaknesses, particularly in the vertical tensile strength (Z-axis) and the shear resistance between layers. The unique mechanism of mechanical enhancement found in natural materials has served as inspiration for solving the above problems. Here this study introduces two novel Interlaced Printing strategies for 3-axis printers inspired by nature. The proposed strategies involve moving the deposition head in the XY plane while periodically adjusting its height in the Z-axis, enhancing interlayer bonding and shear resistance. These strategies were closely examined to understand their impact on toolpath width and layer thickness, considering various parameters. Both strategies resulted in “dumbbell”-shaped toolpath geometries, a characteristic that can be lessened by reducing print speed. Mechanical tests revealed that objects printed using these strategies significantly outperform traditional planar toolpath methods in terms of mechanical strength, showing improvements of 31.9% and 67.5% in interlayer shear resistance. Notably, these new strategies can be combined with each other or with conventional methods, broadening their potential applications.