We investigated the effective surface tension of liquid eutectic gallium indium (EGaIn) with oxide skin. Our visualization of the EGaIn interface during extension and compression indicated the compression causes the wrinkles on the oxide skin, which is then partially smoothed out by extension. We found that the creation of the interface was the combined result of tearing of the oxide skin and the unfolding of oxide wrinkles. Our experiments revealed that the effective surface tension depends on oxide wrinkle, and the value is 0.7 N/m in the absence of wrinkles, but can be as small as $\sim$0.5 N/m in the presence of surface wrinkles.

中文翻译：

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液相共晶镓铟的有效表面张力对表面氧化物皱纹的依赖性

我们研究了具有氧化皮的液态共晶镓铟 (EGaIn) 的有效表面张力。我们在拉伸和压缩过程中对 EGaIn 界面的可视化表明，压缩导致氧化皮上的皱纹，然后通过拉伸部分平滑。我们发现界面的产生是氧化皮撕裂和氧化皱纹展开的综合结果。我们的实验表明，有效表面张力取决于氧化皱纹，在没有皱纹的情况下该值为 0.7 N/m，但可以小到$～$存在表面皱纹时为 0.5 N/m。