电场驱动熔融喷射沉积高分辨率3D打印

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

  • 摘要: 针对传统熔融沉积成型面临的成型精度低和打印材料受限, 基于电流体动力熔融沉积在成形高度、材料种类、基板导电性和平整性、3D成形能力等方面的不足和局限性, 本研究提出一种电场驱动熔融喷射沉积3D打印新工艺, 其采用双加热集成式喷头并施加单极脉冲高电压(单电势), 利用电场驱动微量热熔融材料喷射并精准沉积来形成高分辨率结构.引入两种新的打印模式: 脉冲锥射流模式和连续锥射流模式, 拓展了可供打印材料的种类和范围.通过理论分析、数值模拟和实验研究, 揭示了所提出工艺的成形机理、作用机制以及成形规律.利用提出的电场驱动熔融喷射沉积3D打印方法, 结合优化工艺参数, 完成了三个典型工程案例, 即大尺寸微尺度模具、大高宽比微结构、宏微跨尺度组织支架和网格三维结构.其中采用内径250 μm喷头, 打印出最小线宽4 μm线栅结构, 高宽比达到25:1薄壁圆环微结构.结果表明, 电场驱动熔融喷射沉积高分辨率3D打印具有打印分辨率高、材料普适性广、宏/微跨尺度的突出优势, 为实现低成本、高分辨率熔融沉积3D打印提供了一种全新的解决方案.

     

    Abstract: 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.

     

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