Ice is known to be a rigid and brittle crystal that fractures when deformed. We demonstrate that ice grown as single-crystal ice microfibers (IMFs) with diameters ranging from 10 micrometers to less than 800 nanometers is highly elastic. Under cryotemperature, we could reversibly bend the IMFs up to a maximum strain of 10.9%, which approaches the theoretical elastic limit. We also observed a pressure-induced phase transition of ice from Ih to II on the compressive side of sharply bent IMFs. The high optical quality allows for low-loss optical waveguiding and whispering-gallery-mode resonance in our IMFs. The discovery of these flexible ice fibers opens opportunities for exploring ice physics and ice-related technology on micro- and nanometer scales.

众所周知，冰是一种坚硬易碎的晶体，变形时会破裂。我们证明了生长为直径从 10 微米到小于 800 纳米的单晶冰微纤维 (IMF) 的冰具有高弹性。在低温下，我们可以将 IMF 可逆弯曲到 10.9% 的最大应变，这接近理论弹性极限。我们还在急剧弯曲的 IMF 的压缩侧观察到压力引起的冰从 Ih 到 II 的相变。高光学质量允许在我们的 IMF 中实现低损耗光波导和回音壁模式共振。这些柔性冰纤维的发现为在微米和纳米尺度上探索冰物理和冰相关技术提供了机会。