Shear-Driven Direct-Write Printing of Room-Temperature Gallium-Based Liquid Metal Alloys
Shear-Driven Direct-Write Printing of Room-Temperature Gallium-Based Liquid Metal Alloys
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DOI：
10.1002/adem.201900400
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发表时间：
2019-09-16
影响因子：
3.6
通讯作者：
Tabor, Christopher E.
中科院分区：
文献类型：
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作者：
Cook, Alexander;Parekh, Dishit P.;Tabor, Christopher E.
镓基金属合金在室温下液态时具有高导电性。这些液态金属导体激发了独特的电子应用，例如可重构电路和具有极高应变耐受性的可拉伸组件。此前，液态金属已通过直写成功地形成图案，在室温下按需产生金属导电特征，无需后处理，分辨率低至约10μm。虽然大多数直写工艺通过压力或体积位移从喷嘴挤出材料，但液态金属是通过剪切驱动机制打印的，当金属的氧化物涂层弯液面粘附到打印基材上时，就会发生这种机制，并在远低于在没有剪切的情况下挤出金属所需的压力的情况下从喷嘴“拉出”。在此，阐明了实现液态金属剪切驱动打印的关键操作参数，包括点胶压力、基材的选择、打印高度、周围环境条件以及打印头的速度和加速度。这些研究提供了在室温下实施液态金属剪切驱动打印的最佳实践和限制的指南。
Gallium-based metal alloys have high electrical conductivity in the liquid state at room temperature. These liquid metal conductors inspire unique electronic applications such as reconfigurable circuits and stretchable components with extremely high strain tolerance. Previously, liquid metals have been successfully patterned via direct-writing, yielding metallically conductive features on-demand at room temperature that do not require post-processing, down to a resolution of approximate to 10 mu m. While most direct-write processes extrude materials from a nozzle via pressure or volumetric displacement, liquid metal is instead printed here by a shear-driven mechanism that occurs when the oxide-coated meniscus of the metal adheres to the printing substrate and is "pulled" from the nozzle at pressures that are well-below that needed to extrude the metal in the absence of shear. Herein, the key operating parameters that enable shear-driven printing of liquid metals including dispensing pressure, choice of substrate, print height, the surrounding environmental conditions, and the speed and acceleration of the print head are elucidated. A guide to the best practices as well as limitations for implementing shear-driven printing of liquid metals at room temperature is provided in these studies.