A flexible and springy form of ice
A flexible and springy form of ice
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DOI：
10.1126/science.abj4441
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发表时间：
2021-07
期刊：
影响因子：
56.9
通讯作者：
E. Schulson
中科院分区：
文献类型：
--
作者：
E. Schulson
单晶冰微纤维在弯曲至接近其断裂极限后恢复其形状水冰通常很脆弱，只要延伸<0.1%就会断裂（1）。在本期的第187页，Xu等人（2）表明，直径为几微米或更小的冷冰纤维可以弯曲，而不会断裂成半径为几十微米的近圆形。在卸载时，纤维弹回到其原始形状。这样的应变接近理论极限10.15%（3），因此变形完全是弹性的。微纤维可以像现有技术的片上光导（4，5）一样有效地传输可见光。作者还发现，极端弯曲在压缩侧产生了一个近表面层，该层相对较快地从冰Ih（六方晶体结构）转变为冰II（菱形晶体结构）。这种明显的弹性和透明度反映了材料内没有缺陷，并且结构变化意味着冰Ih到II转化的低障碍。
Single-crystal ice microfibers recover their shape after bending to near their breaking limit Water ice is ordinarily fragile and breaks if extended by just <0.1 % (1). On page 187 of this issue Xu et al. (2) show that fibers of cold ice a few micrometers or less in diameter can bend without breaking into a near-circular shape tens of micrometers in radius. Upon unloading, the fibers spring back to their original shape. Such strains are near the theoretical limit of ∼15% (3), so the deformation is completely elastic. The microfibers can transmit visible light as effectively as state-of-the-art on-chip light guides (4, 5). The authors also find that extreme bending creates a near-surface layer on the compressive side that transforms relatively quickly from ice Ih (hexagonal crystal structure) to ice II (rhombohedral crystal structure). This pronounced elasticity and transparency reflect the absence of defects within the material, and the structure change implies a low barrier for the ice Ih-to-II transformation.