Song Zhiqi, Wu Ting, Zhang Libing, Song Haijun
College of Mechanical Engineering, Jiaxing University, Jiaxing 314001, China; School of Mechanical Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China.
College of Mechanical Engineering, Jiaxing University, Jiaxing 314001, China.
J Colloid Interface Sci. 2025 Jun 15;688:183-192. doi: 10.1016/j.jcis.2025.02.147. Epub 2025 Feb 21.
Flexible actuators are widely used in soft robots, flexible electronics, and biomedicine. However, there still exists a significant challenge in fabricating flexible actuators with multi-response and self-sensing capabilities. In order to address this issue, a novel multi-responsive and self-sensing flexible actuator incorporating an MXene/cellulose nanofibers (MXene/CNF) Janus film was ingeniously developed. MXene/CNF Janus film was prepared using a layered filtration method. The MXene layer of the Janus film exhibits outstanding photothermal conversion properties as well as remarkable electrothermal conversion performance, while its CNF layer showcases excellent moisture absorption properties. As a result of the hydrogen bonding between MXene and CNF, the MXene/CNF Janus film exhibits excellent mechanical properties (Young's modulus of 3620.55 MPa). Using MXene as the printing solution, MXene/polyethylene (MPE) strain sensor with the function of self-sensing the deformation of the flexible actuator was prepared on the PE film by electrohydrodynamic (EHD) printing technology. The MXene/CNF Janus film was assembled with MPE film to fabricate a MXene/CNF-MPE smart flexible actuator with multi-responsive actuation capability and the self-sensing deformation function. Under a near-infrared light intensity of 250 mW/cm, the fabricated actuator can achieve a bending curvature of 1.54 cm within 6.8 s, and it reaches a bending curvature of 4.39 cm within 28 s under a 4 V voltage. Moreover, during the process of environmental humidity changing from 50 % to 80 %, the fabricated actuator demonstrates a bending curvature of 1.81 cm. While responding to these multiple stimuli, the flexible actuator can self-sense the bending deformation through the resistance change of the MPE-based flexible strain sensor. Lastly, the flexible actuator demonstrates the possibilities in gesture recognition of bionic hand and bionic flytrap.
柔性致动器广泛应用于软体机器人、柔性电子和生物医学领域。然而，制造具有多响应和自传感能力的柔性致动器仍然存在重大挑战。为了解决这个问题，一种新型的包含MXene/纤维素纳米纤维（MXene/CNF）双面薄膜的多响应和自传感柔性致动器被巧妙地开发出来。MXene/CNF双面薄膜采用层状过滤法制备。双面薄膜的MXene层具有出色的光热转换性能以及显著的电热转换性能，而其CNF层则展现出优异的吸湿性能。由于MXene和CNF之间的氢键作用，MXene/CNF双面薄膜具有出色的机械性能（杨氏模量为3620.55MPa）。以MXene作为打印溶液，通过电液动力（EHD）打印技术在PE薄膜上制备了具有自传感柔性致动器变形功能的MXene/聚乙烯（MPE）应变传感器。将MXene/CNF双面薄膜与MPE薄膜组装在一起，制造出具有多响应驱动能力和自传感变形功能的MXene/CNF-MPE智能柔性致动器。在250mW/cm的近红外光强度下，所制备的致动器能够在6.8秒内实现1.54cm的弯曲曲率，在4V电压下28秒内达到4.39cm的弯曲曲率。此外，在环境湿度从50%变化到80%的过程中，所制备的致动器表现出1.81cm的弯曲曲率。在响应这些多种刺激时，柔性致动器可以通过基于MPE的柔性应变传感器的电阻变化自传感弯曲变形。最后，柔性致动器展示了在仿生手和仿生捕蝇草手势识别方面的可能性。
