Khakse Pranjal, Dangers Falco, Elsersawy Rawan, Khondoker Mohammad Abu Hasan
Industrial Systems Engineering, Faculty of Engineering and Applied Science, University of Regina, Regina, SK S4S 0A2, Canada.
Materials (Basel). 2024 Jun 6;17(11):2770. doi: 10.3390/ma17112770.
This article demonstrates scalable production of liquid metal (LM)-based microwires through the thermal drawing of extrudates. These extrudates were first co-extruded using a eutectic alloy of gallium and indium (EGaIn) as a core element and a thermoplastic elastomer, styrene-ethylene/butylene-styrene (SEBS), as a shell material. By varying the feed speed of the co-extruded materials and the drawing speed of the extrudate, it was possible to control the dimensions of the microwires, such as core diameter and shell thickness. How the extrusion temperature affects the dimensions of the microwire was also analyzed. The smallest microwire (core diameter: 52 ± 14 μm and shell thickness: 46 ± 10 μm) was produced from a drawing speed of 300.1 mm s (the maximum attainable speed of the apparatus used), SEBS extrusion speed of 1.50 mm s, and LM injection rate of 5 × 105 μL s at 190 °C extrusion temperature. The same extrusion condition without thermal drawing generated significantly large extrudates with a core diameter of 278 ± 26 μm and shell thickness of 430 ± 51 μm. The electrical properties of the microwires were also characterized under different degrees of stretching and wire kinking deformation which proved that these LM-based microwires change electrical resistance as they are deformed and fully self-heal once the load is removed. Finally, the sewability of these microwires was qualitatively tested by using a manual sewing machine to pattern microwires on a traditional cotton fabric.
本文展示了通过对挤出物进行热拉伸来规模化生产基于液态金属（LM）的微丝。这些挤出物首先使用镓铟共晶合金（EGaIn）作为芯材、热塑性弹性体苯乙烯-乙烯/丁烯-苯乙烯（SEBS）作为壳材进行共挤出。通过改变共挤出材料的进料速度和挤出物的拉伸速度，可以控制微丝的尺寸，如芯直径和壳厚度。还分析了挤出温度如何影响微丝的尺寸。最小的微丝（芯直径：52±14μm，壳厚度：46±10μm）是在190℃挤出温度下，以300.1mm/s的拉伸速度（所用设备的最大可达速度）、1.50mm/s的SEBS挤出速度和5×105μL/s的液态金属注入速率生产出来的。在不进行热拉伸的相同挤出条件下，会产生直径为278±26μm、壳厚度为430±51μm的明显更大的挤出物。还对微丝在不同程度的拉伸和扭结变形下的电学性能进行了表征，结果证明这些基于液态金属的微丝在变形时会改变电阻，并且在去除负载后能完全自愈。最后，通过使用手动缝纫机在传统棉布上绘制微丝，对这些微丝的可缝纫性进行了定性测试。
