Effect of Origami-Inspired Infill Design on the Mechanical Properties of Vacuum-Assisted Material Extrusion Printed Samples

Fused deposition modeling (FDM) is a widely used additive manufacturing technique that constructs 3D objects layer by layer using materials like PLA and ABS. However, optimizing the mechanical strength of printed parts remains challenging due to poor interlayer bonding along the z-axis. This study addresses this challenge by integrating a vacuum system into an open-source desktop FDM printer and investigating the effects of atmospheric and vacuum pressure on the mechanical properties of three origami-inspired infill patterns: Kresling, Miura-Ori, and Mountain Valley. Samples were printed with PLA and ABS filaments and analyzed for tensile strength and microstructure such as scanning electron microscopy and FTIR analysis. The results show that the Miura-Ori pattern consistently delivered superior performance, with vacuum-printed samples under 20 kPa showing significantly higher maximum stress and elastic modulus (PLA: 29.82 MPa, 1361.72 MPa; ABS: 24.87 MPa, 1122.07 MPa). Scanning electron microscopy confirmed improved layer bonding in vacuum-printed samples. At the same time, FTIR analysis revealed that ABS samples printed with the Miura-Ori pattern under vacuum conditions showed increased absorbance for styrene rings and thiocyanates, with a shift in the absorption maximum to lower wave numbers, indicating improved molecular mobility. For PLA, shifts in the -C = O stretching band under vacuum conditions suggest polymer structure and crystallinity changes, affecting its mechanical properties. These findings highlight the potential of vacuum-assisted FDM printing for improving the quality and mechanical strength of 3D-printed components. This research can be used in fields that need more robust, durable 3D-printed parts. It can help create lightweight, vital components like brackets and panels in the aerospace and automotive industries. Medical devices could benefit by making more durable custom prosthetics and tools. It can be applied to create tougher housings and enclosures in consumer electronics. Robotics and drones could use it to print stronger, lighter parts like frames and gears. It can also improve the production of sporting goods and architectural components where strength and reliability are essential.