High-resolution fused deposition 3D printing based on electric-field-driven jet

The existing fused deposition modeling (FDM) technique faces disadvantages of low resolution and limited printable materials; meanwhile the E-jet-based fused deposition method confronts limitations associated with the formation height, material type, conductivity, and flatness of the substrate, and the 3D forming ability. Herein, a new technology called electric-field-driven fused-jet deposition 3D printing was proposed. In the proposed technology, a dual-heated integrated nozzle connected to a single positive-pulse high voltage (single potential) was used to eject and precisely deposit a small amount of molten material to form a high-resolution structure based on the drive of the electric field force. Two novel printing modes, the continuous-cone and pulse-cone jet modes, were developed to broaden the range of printable materials using the proposed technique. The mechanism and rules of formation for the proposed process were systematically investigated via theoretical analysis, numerical simulation, and experimental verification. Using optimized process parameters and the proposed electric-field-driven fused-jet deposition 3D printing method, three typical cases, including a large micro-scale mold, a high-aspect-ratio micros-scale structure, a macro-micro-scale tissue scaffold, and a three-dimensional grid structure were fabricated. Outstanding results were obtained, including the printing of a wire grid structure with a minimum line width of 4 μm and a thin-walled ring microstructure with an aspect ratio of 25:1 using a nozzle with an inner diameter of 250 μm. The experimental results demonstrate that the proposed electric-field-driven fused-jet-deposition 3D printing method is a promising and effective method that meets the requirements of the high-resolution FDM process at low cost. The new technolgy proposed in this paper offers a novel solution for realizing high-resolution and macro/micro-scale fused-jet deposition 3D printing at low cost with good material universality.