碳纳米管复合纤维的电化学驱动行为研究

The development of artificial muscle fibers that mimic the natural muscles is of great importance for applications in many areas. Carbon nanotube fibers have such excellent properties as light weight, high conductivity, high thermal conductivity and novel structural flexibility. They can generate actuations of stretch/release and rotation when driven by electrochemically charging and discharging, temperature difference, or solvent adsorption. Therefore, these integrated features make it a very promising candidate for the development of intelligent artificial muscle fibers. The electrochemically driven carbon nanotube fibers have the advantages of a low operating voltage, non-obvious thermal effect, quick response and easy control (The actuation strokes and actuation speeds can be adjusted by controlling the voltage function). However, pure carbon nanotube fibers commonly have a very small capacitance less than 10 F/g, which not only limits the actuation performance but also causes difficulty to maintain the actuation state after turning off the applied voltage. The present project aims at developing high-performance intelligent carbon nanotube composite fiber muscles by investigating the issues of increasing the capacitance of the muscles using additional high-capacitance nanomaterials, the regulation of the assembling structures of the composite fibers, and the electrochemical actuation behaviors of composite fiber muscles.

仿照生物肌肉，制备具有相似运动能力的人工肌肉纤维具有非常重要的实用意义。碳纳米管纤维具有诸如轻质、超强、高导电、高导热和结构柔性等优异属性，并可通过电化学充放电、温差、溶剂吸附等方式产生伸缩和转动，因而，非常有望用于研发智能人工肌肉纤维。其中，碳纳米管纤维的电化学驱动具有工作电压低、热效应不明显、反应快和易于控制(驱动量和驱动速度可由电压的大小和波形控制)等优点。然而，纯碳纳米管纤维的电容较小（通常低于10 F/g），这不仅使纤维的驱动性能受到限制，还导致在撤掉电压后纤维的驱动状态难以维持。基于此，本项目拟将高电容纳米材料和碳纳米管混纺提高复合纤维的电容，调控复合纤维的组装结构并研究其与纤维电化学驱动行为的关系，探索开发高性能智能纤维驱动器。

近些年来人工肌肉纤维的发展备受关注，人工肌肉纤维与生物肌肉运动行为类似并可以产生远高于生物肌肉的驱动量和能量密度。本项目针对目前电化学驱动人工肌肉纤维驱动量低展开研究，重点研究了碳纳米管复合纤维的制备及组装结构调控、复合纤维的力学和电化学电容性能表征、组装结构、电化学性能以及电化学驱动行为三者间关系和固态复合纤维驱动器的制备和测试等四方面内容。发现纤维中多级结构构筑对于仿生肌肉纤维的驱动量具有重要作用，多级结构的引入增大了离子在纤维中的嵌入量和进出速度，因而可以有效提高碳纳米管纤维的驱动量和响应速率。构筑了层状碳纳米管纤维和石墨烯/碳纳米管叠层复合纤维两类具有多级结构的人工肌肉纤维。分别实现了人工肌肉纤维收缩驱动量在水系电解液中-2V驱动电压下达到8.1%，输出能量密度为236J/kg（为生物骨骼肌的6.1倍）；有机电解液中，2.5V驱动电压下，驱动量达到50%以上，输出能量密度为1.5kJ/kg（生物骨骼肌的38.7倍），并且具有良好的循环稳定性。以此为基础构筑了在空气中可稳定运行人工肌肉纤维。研究成果有望在柔性外骨骼、仿生柔性机器人、仿生飞行器、医疗等方面具有重要的应用前景。.在项目的资助期间，发表相关的学术论文12篇，其中影响因子大于6的8篇，截止2020年1月13日引用共计121次。申请专利4项，培养博士生2名，硕士生6名。