Droplet-based 3D printing is a promising technique for metal forming in space, owing to the advantages of dispensing without large-scale energy equipment or customized materials. However, the extreme environment in space, for example microgravity, would change the printing mechanisms significantly compared with those on the ground, which hinders the application of droplet-based 3D printing in space. To develop a droplet-based 3D printing technique suitable for space manufacturing, the droplet deposition behavior under microgravity should be physically simulated in normal gravity environment. Here, a novel experimental system comprising an anti-gravity electric field was developed to suppress the gravity effects on droplets deposition by manipulating the droplets to perpendicularly deposit on a vertical substrate. Parameter mappings of regulation voltage were established based on theoretical modeling and experimental results. The controllable region of flight trajectories locates in the top half of the electric field. The charging voltage shows better regulation accuracy than the deflection voltage. Under the manipulation of the electric field, droplets deposit on the substrate and solidify into regular morphologies. The solidified contour and adhesion force of the deposited droplets were measured. Finally, a freestanding pillar and a bending wall structure were fabricated. This work demonstrates the feasibility and effectiveness of the anti-gravity electric field in manipulating droplets to perpendicularly deposit on vertical surfaces against gravity, and forming 3D structures.

基于液滴的3D打印技术是一种有前途的空间金属成型技术，这归因于无需大规模能源设备或定制材料即可进行点胶的优势。然而，与地面上的那些相比，空间中的极端环境（例如微重力）将显着改变打印机制，这阻碍了基于液滴的3D打印在空间中的应用。要开发适用于空间制造的基于液滴的3D打印技术，应在正常重力环境下物理模拟微重力下的液滴沉积行为。在这里，开发了一种新型的包含反重力电场的实验系统，以通过控制液滴垂直沉积在垂直基板上来抑制重力对液滴沉积的影响。根据理论模型和实验结果建立了稳压电压的参数映射。飞行轨迹的可控制区域位于电场的上半部分。充电电压显示出比偏转电压更好的调节精度。在电场的控制下，液滴沉积在基板上并固化成规则的形态。测量沉积的液滴的固化轮廓和粘附力。最终，制造了独立柱和弯曲壁结构。这项工作证明了反重力电场在操纵液滴抵抗重力垂直沉积在垂直表面上并形成3D结构方面的可行性和有效性。飞行轨迹的可控制区域位于电场的上半部分。充电电压显示出比偏转电压更好的调节精度。在电场的控制下，液滴沉积在基板上并固化成规则的形态。测量沉积的液滴的固化轮廓和粘附力。最终，制造了独立柱和弯曲壁结构。这项工作证明了反重力电场在操纵液滴抵抗重力垂直沉积在垂直表面上并形成3D结构方面的可行性和有效性。飞行轨迹的可控制区域位于电场的上半部分。充电电压显示出比偏转电压更好的调节精度。在电场的控制下，液滴沉积在基板上并固化成规则的形态。测量沉积液滴的凝固轮廓和粘附力。最后，制造了独立式支柱和弯曲墙结构。这项工作证明了反重力电场在处理液滴以抵抗重力垂直沉积在垂直表面上并形成3D结构方面的可行性和有效性。在电场的控制下，液滴沉积在基板上并固化成规则的形态。测量沉积的液滴的固化轮廓和粘附力。最终，制造了独立柱和弯曲壁结构。这项工作证明了反重力电场在处理液滴以抵抗重力垂直沉积在垂直表面上并形成3D结构方面的可行性和有效性。在电场的控制下，液滴沉积在基板上并固化成规则的形态。测量沉积的液滴的固化轮廓和粘附力。最终，制造了独立柱和弯曲壁结构。这项工作证明了反重力电场在操纵液滴抵抗重力垂直沉积在垂直表面上并形成3D结构方面的可行性和有效性。