Underwater sensing plays a vital role in perceiving various hydrodynamic stimuli for underwater operations, while fishes evolve an adaptable, durable, and multifunctional lateral line sensory system to feel mechanical deformations from nearly all sources as well as water temperature changes. Such perfect integration of multiple functions into one biological system poses a great challenge for artificial soft sensors. Here, by constructing a stretchable and water‐proof core‐cladding hydrogel–elastomer hybrid optical fiber, nearly all the underwater sensations of fish lateral lines can be realized with unprecedented sensing stability. High‐refractive‐index salt, LiBr, is introduced to the hydrogel core to enable long‐range light propagation with a low loss coefficient (≈0.32 dB cm⁻¹), and the dissimilar yet tightly adhered hydrogel–elastomer interface is readily deformable, contributing to the ultrasensitive optical response to subtle environmental stimulations, induced by either motions, hydrostatic pressure variations, ultrasonic/audible sound waves, or water flows. Moreover, the optical loss of the hybrid fiber is linearly responsive to wide temperature changes (5–70 °C), caused by the altered light scattering from hydrogel chain clustering. The present elastomer–hydrogel hybrid optical fiber offers a new designing strategy in developing next‐generation underwater stretchable ray‐optic sensors.

中文翻译：

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界面可变形的热敏水凝胶-弹性体混合纤维，可用于多种水下传感

水下感测在感知各种水下动力刺激方面起着至关重要的作用，而鱼类则进化出一种适应性强，耐用且多功能的侧线感官系统，以感知几乎所有来源的机械变形以及水温变化。将多种功能完美地集成到一个生物系统中对人工软传感器提出了巨大的挑战。在这里，通过构建可拉伸且防水的芯层水凝胶-弹性体混合光纤，几乎可以实现鱼侧线的几乎所有水下感知，并具有前所未有的感知稳定性。高折射率的盐，溴化锂，被引入到水凝胶芯，以使长范围内具有低损耗系数光传播（≈ 0.32分贝厘米^-1），并且水凝胶与弹性体之间的界面紧密结合，很容易变形，从而对运动，静水压力变化，超声/可听声波或水流引起的细微环境刺激产生了超灵敏的光学响应。此外，由于水凝胶链簇的光散射改变，混合光纤的光损耗对宽温度变化（5-70 ° C）具有线性响应 。当前的弹性体-水凝胶混合光纤为开发下一代水下可伸缩射线传感器提供了一种新的设计策略。