Investigation of 3D-printed PLA–stainless-steel polymeric composite through fused deposition modelling-based additive manufacturing process for biomedical applications

Abstract

Among the several 3D printing technologies, fused deposition modelling (FDM) is gaining popularity because it can fabricate geometrically complex shapes of polymeric bio-implants at reasonable quality and cost mainly due to lower cost of FDM-based 3D printers as well as the filament form of feedstock material. Particularly, to cater the need of cost-effective biomedical applications, both poly(lactic) acid (PLA) and stainless-steel materials individually displayed the biocompatibility for various biomedical applications. The pure polymeric components are generally lower in mechanical strength, but these limitations can be resolved by developing a polymer–metallic composite; therefore, the recently developed PLA–stainless-steel composite was selected for the present work. This is new material and the current literature lacks in providing the necessary FDM processing parameters to obtain desired functional properties of PLA–stainless-steel components with unaltered biocompatibility. Therefore, the objective here is to obtain the optimized processing parameters through the design of experiments that shows the desired functional properties of PLA–stainless-steel specimens manufactured by FDM and later validate the structural strength through the tensile and impact tests. It was observed that the PLA–stainless-steel composite has a toughness of 18 kJ/m² and has an ultimate tensile strength of ~69 MPa at 45° and ~23 MPa at 90° raster orientation of the print. Biocompatibility of the PLA–stainless-steel polymeric composite was assessed using pre-osteoblast cells, and materials were found to have biocompatibility unchanged from pure PLA. Overall, it was proved from this work that the low-cost desktop FDM printer can be numerically optimized using statistical analyses to fabricate the next-generation biomaterials for biomedical implants with tailored dimensions and surface finish with required mechanical strength and biocompatibility.