Exploring high-performance flexible actuators derived from natural resources is crucial for the development of green and environmentally friendly smart devices. In this study, we exfoliated natural silk using a green deep eutectic solvent (DES) to obtain silk nanofibers with average diameters and lengths in the ranges of 30–40 and 2–5 μm, respectively. After the DES treatment, the internal secondary conformation of silk changed; the concentration of β-sheets increased; and the random coil structure was destroyed. Furthermore, a silk nanofibrous membrane was fabricated via suction filtration-induced self-assembly. The fabricated actuators demonstrated an outstanding response speed of 25 s^–1 within a relative humidity range of 0–70%, accompanied by a maximum response value of 70%. They exhibited exceptional durability, with a bending capability of 1.1 cm^–1, and could be folded up to 20 times. By leveraging these properties, we successfully developed a unique robot capable of directional crawling and weightlifting through moisture-driven mechanisms. Notably, this innovative robot exhibited an extraordinary lifting capacity, which exceeded ten times its own weight. This paper presents a green and environmentally friendly next-generation method for manufacturing natural biobased humidity-responsive actuators.

中文翻译：

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基于使用低共熔溶剂剥离的丝纳米纤维的本质自驱动湿度执行器

探索源自自然资源的高性能柔性执行器对于开发绿色环保智能设备至关重要。在这项研究中，我们使用绿色低共熔溶剂 (DES) 剥离天然丝，以获得平均直径和长度分别在 30-40 和 2-5 μm 范围内的丝纳米纤维。 DES处理后，丝内部二级构象发生变化； β-折叠浓度增加；无规线圈结构被破坏。此外，通过吸滤诱导自组装制备了丝纳米纤维膜。所制造的执行器在 0-70% 的相对湿度范围内表现出 25 s ^–1的出色响应速度，同时最大响应值为 70%。它们表现出卓越的耐用性，弯曲能力为 1.1 cm ^–1，最多可折叠 20 次。通过利用这些特性，我们成功开发了一种独特的机器人，能够通过湿气驱动机制进行定向爬行和举重。值得注意的是，这款创新机器人表现出非凡的起重能力，超过其自身重量的十倍。本文提出了一种绿色环保的下一代制造天然生物基湿度响应执行器的方法。