Qin Juanrong, Feng Pingping, Wang Yaru, Du Xiaolong, Song Botao
Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069 Shaanxi, People's Republic of China.
ACS Appl Mater Interfaces. 2020 Oct 14;12(41):46719-46732. doi: 10.1021/acsami.0c13594. Epub 2020 Sep 29.
Although progress has been made in the construction of stimulus-responsive actuators, the performance of these smart materials is still unsatisfactory, owing to their slow response, small deformation amplitude, uncontrollable bending direction, and unidirectional (2D to 3D) transformation. Herein, we employ a structural bionic strategy to design and fabricate a novel water/moisture responsive nanofibrous actuator with an alignment degree gradient. Owing to its different contraction gradient amplitudes along the thickness direction and the unique physical property of the nanofibrous material, the prepared actuator exhibits excellent shape deformation performance, including superfast response (less than 150 ms), controllable deformation directions, multiple actuation models, multiple dimensional deformation (0D-3D, 1D-3D, 2D-3D, and 3D-3D), large bending curvature (25.3 cm), and a repeatability rate of at least 1000. The actuation performance of the nanofibrous actuator is superior to the currently reported actuators. The nanofibers are integrated into layer-by-layer and side-by-side structures to achieve competitive and independent actuation, respectively. The outstanding shape-changing properties of the nanofibrous actuator result in the construction of practical intelligent devices for applications such as amphibious movement, intelligent protection, and cargo transportation. The nanofibrous actuator designed herein exhibits tremendous potential in soft robotics, sensors, and biomedicine.
尽管在刺激响应型致动器的构建方面已取得进展，但由于其响应缓慢、变形幅度小、弯曲方向不可控以及单向（二维到三维）转变，这些智能材料的性能仍不尽人意。在此，我们采用结构仿生策略来设计和制造一种具有取向度梯度的新型水/湿气响应型纳米纤维致动器。由于其沿厚度方向不同的收缩梯度幅度以及纳米纤维材料独特的物理性质，所制备的致动器表现出优异的形状变形性能，包括超快响应（小于150毫秒）、可控的变形方向、多种驱动模式、多维变形（0D - 3D、1D - 3D、2D - 3D和3D - 3D）、大弯曲曲率（25.3厘米）以及至少1000次的重复率。纳米纤维致动器的驱动性能优于目前报道的致动器。纳米纤维被整合到逐层和并排结构中，分别实现有竞争力的和独立的驱动。纳米纤维致动器出色的形状变化特性导致构建了用于两栖运动、智能保护和货物运输等应用的实用智能设备。本文设计的纳米纤维致动器在软机器人技术、传感器和生物医学领域展现出巨大潜力。
