Researchers Use Liquid Metal to Create Wires That Stretch Eight Times Their Original Length

来自北卡罗来纳州立大学的研究人员创建了导电线，该导电线的原始长度最多可以延长八倍，同时仍能运行。电线可用于从耳机到电话充电器的所有物品，并具有用于电子纺织品的潜力。

To make the wires, researchers start with a thin tube made of an extremely elastic polymer and then fill the tube with a liquid metal alloy of gallium and indium, which is an efficient conductor of electricity.

“Previous efforts to create stretchable wires focus on embedding metals or other electrical conductors in elastic polymers, but that creates a trade-off,” says Dr. Michael Dickey, an assistant professor of chemical and biomolecular engineering at NC State and co-author of a paper on the research.

“Increasing the amount of metal improves the conductivity of the composite, but diminishes its elasticity,” Dickey says. “Our approach keeps the materials separate, so you have maximum conductivity without impairing elasticity. In short, our wires are orders of magnitude more stretchable than the most conductive wires, and at least an order of magnitude more conductive than the most stretchable wires currently in the literature.”Video of the stretchable wires is available here.

While the manufacturing of the new wires is relatively straightforward, Dickey notes that one challenge needs to be addressed before the wires can be considered for popular products: how to minimize leakage of the metal if the wires are severed.

The paper, “Ultrastretchable Fibers with Metallic Conductivity Using a Liquid Metal Alloy Core,” is published online inAdvanced Functional Materials. The paper was co-authored by Shu Zhu, a former undergraduate at NC State; Dr. Ju-Hee So, a former Ph.D. student at NC State; Robin Mays and William Barnes, Ph.D. students at NC State; Dr. Sharvil Desai, a former postdoctoral researcher at NC State; and Dr. Behnam Pourdeyhimi, the William A. Klopman Distinguished Chaired Professor of Materials in NC State’s College of Textiles and a professor of chemical and biomolecular engineering in the university’s College of Engineering.

The research was funded by a National Science Foundation (NSF) CAREER award and the NSF’s Research Triangle Materials Research Science & Engineering Center.

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Note to Editors:The study abstract follows.

“Ultrastretchable Fibers with Metallic Conductivity Using a Liquid Metal Alloy Core”

Authors: Shu Zhu, Ju-Hee So, Robin Mays, Sharvil Desai, William R. Barnes, Behnam Pourdeyhimi, Michael D. Dickey

Published：在线12月13日，Advanced Functional Materials

Abstract:本文描述了可超紧密且具有金属电导率的纤维的制造和表征。纤维由液态金属合金，共凝着甘露膜（EGAIN）组成，并注入了由三嵌段共聚物组成的可拉伸空心纤维的核心，poly [苯乙烯b-（乙烯-b-叔丁基）-b-苯乙烯]（Sebs）（Sebs）） 树脂。通过使用市售熔体加工方法，空心纤维易于大规模生产，具有控制尺寸。纤维类似于常规的金属电线（金属芯，被聚合物绝缘包围），但可以在保持电导率的同时进一步拉伸数量级。机械测量带有和没有液态金属内部的机械测量表明，液体对纤维的机械性能具有可忽略的影响，这与大多数导电复合纤维形成鲜明对比。纤维还具有有或没有金属的相同触觉特性，因为导电元件仅限于纤维的核心。正如预期的那样，电测量结果表明，随着纤维的细长和横截面区域的变窄，纤维会增加电阻。具有较大直径（〜600 [微米]）的纤维从三角形变为拉伸过程中更圆形的横截面，这具有将电阻降低到理论预测的较低的吸引力。液体在纤维伸长过程中流动的能力可导致高达1000％的应变和金属电导率（〜3×10-5 [Omega] cm）高达700％应变。为了证明其实用性，可将超湿纤维用作可伸缩耳机和可拉伸电池充电器的电线。