Rheological Modification of Liquid Metal for Additive Manufacturing of Stretchable Electronics
Rheological Modification of Liquid Metal for Additive Manufacturing of Stretchable Electronics
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DOI：
10.1002/admt.201700351
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发表时间：
2018-04-01
影响因子：
6.8
通讯作者：
Menguc, Yigit
中科院分区：
文献类型：
--
作者：
Daalkhaijav, Uranbileg;Yirmibesoglu, Osman Dogan;Menguc, Yigit
快速制造柔性电子产品的挑战之一是从可伸缩导体印刷电路所涉及的复杂性。共晶镓合金通常用作导电材料，因为它们具有独特的高导电性、自愈性和可伸长性。然而，通过利用薄的氧化镓薄膜提供的结构稳定，有限的3D打印已经被证明。由于镓合金的低粘度和高表面张力，很难用液态金属(LM)打印垂直结构，这容易导致结合。提出了一种通过加入导电纳米或微镍填料来改变液态金属的物理结构的方法。由此产生的液态金属的流变性修改为糊状物，大大增加了流体弹性系数和屈服应力，使其可以3D打印。此外，变质处理还保持了纯液态金属的高电导率(3.9x10(6)+/-9.5x10(5)S m(-1))和延伸性(超过350%应变)。使用这种高导电性金属浆料打印3D立式结构的能力为制造更复杂的可伸缩电子产品开辟了新的机会。
One of the challenges to rapidly manufacturing flexible electronics is the complexity involved in printing circuitry from stretchable conductors. Eutectic gallium alloys are typically used as the conductive material because they have unique high conductivity, self-healing, and stretchable properties. However, limited 3D printing has been demonstrated by leveraging the structural stabilization provided by the thin gallium oxide film. Vertical structures are difficult to print with a liquid metal (LM) due to the low viscosity and high surface tension of the gallium alloy, which easily leads to coalescence. A method is presented to alter the physical structure of the liquid metal through the incorporation of a conductive nano- or micronickel fillers. The resulting rheological modification of the liquid metal to a paste drastically increases the fluidic elastic modulus and yield stress, rendering it 3D printable. Further, the modification retains the high electrical conductivity (3.9 x 10(6) +/- 9.5 x 10(5) S m(-1)) and stretchability (over 350% strain) of pure liquid metal. The ability to print 3D standing structures using this highly conductive metal paste opens up new opportunities to manufacture more complex stretchable electronics.