This paper presents a study of the solvent-based precursors (inks) derived from composites of polyethylene oxide, graphene flakes and micro-scale spherical Eutectic Gallium Indium (EGaIn) fillers and their processing through direct-ink-writing (DIW). The presented studies focus on the influence of EGaIn fillers on ink rheology, DIW process mechanisms as well as electrical conductivity of the printed structures. The results show that EGaIn fillers vary the ink rheology towards a more elastic behavior with lower extensional viscosity. This leads to ink filaments capable of withstanding large extensional strains during DIW, forming continuous prints even when printing speed is higher than ink flow speed, and producing features with line width smaller than the nozzle diameter. Electrical conductivity of the prints reduces with increasing strain due to the deformation of the liquid EGaIn fillers along the printing direction. These findings can be utilized to control the DIW process and the properties of the conductive polymer composites.

本文介绍了对源自聚环氧乙烷、石墨烯薄片和微型球形共晶铟 (EGaIn) 填料的复合材料的溶剂基前体（油墨）及其通过直接墨水书写 (DIW) 进行加工的研究。所提出的研究侧重于 EGaIn 填料对油墨流变学、DIW 工艺机制以及印刷结构的导电性的影响。结果表明，EGaIn 填料使油墨的流变性朝着更具弹性的行为变化，同时具有更低的拉伸粘度。这导致墨丝能够在 DIW 期间承受较大的拉伸应变，即使在打印速度高于墨水流速时也能形成连续打印，并产生线宽小于喷嘴直径的特征。由于液态 EGaIn 填料沿印刷方向变形，印刷品的电导率随着应变的增加而降低。这些发现可用于控制 DIW 过程和导电聚合物复合材料的性能。