Fluid-assisted one-step fabrication of fused deposition molding 3D printing parts with conductive networks and gradient functionalities

The steps of preparing fused deposition molding (FDM) 3D printing conductive materials by melt-compounding are cumbersome, and the addition of fillers degrades the bulk properties of the materials, which limits the promotion and application of FDM 3D printing conductive materials. The FDM 3D printing conductive parts can be prepared by embedding conductive fillers on the surface of the printing filaments or parts, but available preparation methods are difficult to accomplish in one step. Herein, we introduce a facile method of one-step preparation of conductive parts by fluid-assisted FDM 3D printing. In this method, a thin tube transports conductive fluid, loads conductive carbon nanotubes (CNTs) onto the surface of molten polycaprolactone (PCL) filaments at the nozzle, and forms the CNT layers to prepare conductive parts in one step. The SEM and Raman results show that the CNTs are embedded on the surface of the PCL filaments. The sample can obtain a con-ductivity of 4.24 S m-1 loading only 4 mg CNTs. It also revealed that the preparation method has little effect on the mechanical properties of the FDM 3D printed PCL parts. The results exhibited that the as-proposed one-step preparation of conductive parts by fluid-assisted 3D printing could provide a new method for FDM 3D printing and fabricating high-performance parts, which has great potentials in various fields.