Jun Yan,Xin Song,Haipeng Wu,Guoqiang Zhang,Huaiguo Xue,Jiefeng Gao
Superhydrophobic and light-responsive actuators (SLRAs) can be driven to move on water surface remotely and in a non-contact manner, and have shown promising applications in soft robotics, environmental protection, etc. It remains a big challenge to develop high performance SLRAs with excellent thermal stability, fast light responsivity and controllable motion. Here, we propose a layer-by-layer vacuum filtration method to prepare flexible, freestanding and superhydrophobic composite films composed of alternately deposited oleylamine modified acid carbon nanotubes (O-ACNTs) and aramid nanofibers (ANFs). The composite film has excellent thermal stability with the maximum weight loss rate temperature as high as 520 ℃. The closely packed structure and strong interlayer interaction ensure the surface stability and durability of the composite film. The composite film possesses excellent photothermal conversion performance, and can maintain the structure integrity without deformation when its surface temperature reaches 208 °C. When used as a self-propelled actuator, the SLRA film can response to the light quickly and move on the water surface, and the motion speed and direction can be controlled by adjusting the irradiation intensity and position. The outstanding thermal stability guarantees the stability and reliability of the self-propelled motions. The present study opens a new avenue to design high performance SLRAs.
Liquid crystal elastomers (LCEs) are among the key smart materials driving soft robotics and LCE fibers have garnered significant attention for their rapid response characteristics. A convenient and fast method for programming orientations of liquid crystal molecules is a focal issue in LCE applications. Inspired by the Kirigami technique, here, we propose a novel method for fabricating LCE fibers based on customizable cutting paths and secondary photo-cross-linking. While most existing LCE actuators exhibit contraction ratios of around 30 to 40%, our conical spiral actuator, fabricated from LCE-carbon nanotube (CNT) fiber using the proposed method, demonstrates a significantly higher contraction ratio, reaching up to 80%. The contraction ratio can be controlled by adjusting the cutting path parameters and we elucidate the mechanism linking liquid crystal orientation to the distribution of contraction ratio. Additionally, the conical spiral deformation of the actuator can be manipulated with light radiation, enabling versatile functionalities such as catching, twisting, and gripping. We hope that the novel LCE fiber fabrication method presented provides new insights for programming and preparing LCE fibers, offering a valuable reference for the application of smart soft materials.
危险品化学品经营许可证（带存储）