A hybrid additive manufacturing platform based on fused filament fabrication and direct ink writing techniques for multi-material 3D printing

Among the available additive manufacturing (AM) technologies, fused filament fabrication (FFF) technique-broadly used in academia-seems to be a promising alternative to injection molding process in industry regarding physical prototypes. This is partially due to its accessibility, fast responsiveness and the substantial development of low-cost and open-source machines and filament materials. However, beyond the ongoing research efforts related to this material extrusion technique, the inherent layer-by-layer deposition strategy leads to lower mechanical performances compared to traditional formative and subtractive manufacturing processes. Indeed, recurrent anisotropic material properties and fracture strength still remains as the key challenges to be tackled in FFF, so as to get close to mechanical performances obtained by injection molding. In such a context, the main objective of the article is to extend mechanical parts' performances by improving fracture strength of FFF printed parts. To do so, an innovative hybrid additive manufacturing platform-combining FFF and direct ink writing (DIW) techniques-is proposed. The proposed platform is implemented through a dedicated digital workflow covering process planning algorithms and a new modular concept of hybrid 3D printer. The added value of the proposal is demonstrated with tensile strength tests and opens the door to multi-material 3D printing.