电驱动液晶弹性体复合材料研究

Liquid crystal elastomer (LCE), as a new type of smart materials, has broad application prospects in the fields of bionic materials and micro-robots. Aiming at the deficiencies of the traditional electric responsive LCEs, such as too few related studies, the lack of preparation process of the conductive layer and the single electromorphic mode, this project plans to prepare a novel kind of polyethylene/polysiloxane LCE with electrical responsive ability by screen-printing technology. The main contents include: the design and synthesis of liquid crystal monomer, preparation of polysiloxane LCEs, screen printing of ultra-thin stretchable conductive layer in specific areas of LCEs, preparation of polyethylene/polysiloxane bilayer film, exploration of the complex and locally programmable control deformation ability of the bilayer film under the electrical stimulation. The exploration of the basic control methods and inherent laws of the electro-deformation of such composite LCE film will help to broaden applications of screen-printing technology in the field of liquid crystalline materials. The composite LCE film will be further assembled into soft actuators such as mechanical grippers or cylindrical robots, which will help to verify the feasibility of using this electric-responsive polyethylene/polysiloxane LCE composite film as a new type of electric driven smart materials based on screen-printing technology and actively promote the practical application of LCE materials.

液晶弹性体，作为一种新型智能材料，在仿生材料、微型机器人等领域有广泛的应用前景。针对目前电驱动液晶弹性体的研究偏少、导电层的制备工艺欠缺以及电致形变模式单一等问题，本项目拟利用丝网印刷技术制备一类新型的具有电响应能力的聚乙烯/聚硅氧烷液晶弹性体复合膜材料，具体研究内容包括液晶单体的设计与合成、聚硅氧烷液晶弹性体的制备、在液晶弹性体特定区域丝网印刷超薄可拉伸导电层、聚乙烯/聚硅氧烷液晶弹性体双层复合膜的制备以及电刺激下复合膜复杂、局部可编程控制形变能力的研究。通过寻找此类液晶弹性体复合膜材料电致形变的基本方法和内在规律，拓宽丝网打印技术在液晶高分子领域的应用前景。将这种复合膜组装成为机械手爪、圆柱状机器人等软驱动器，初步验证基于丝网印刷技术的电刺激-响应聚乙烯/聚硅氧烷液晶弹性体复合膜作为一种新型电驱动智能材料在软驱动器领域的应用前景，为液晶弹性体走向实际应用起到积极的推动作用。

目前，在制备电驱动高分子软驱动器方面仍然存在一些难题。首先，为了提高高分子材料的导电性，通常将碳纳米管、银纳米线、石墨烯等无机纳米导电材料掺杂在其中，从而导致高分子材料本身的力学性能有所减弱并增加了制备方案的成本和复杂性；其次，为了实现电致形变高分子材料在应用中得到良好的供电，通常会在高分子材料中引入导线等元件。由于导线等元件的引入不可避免地阻碍了电驱动高分子材料的复杂驱动，故大多数已报道的电驱动聚合物软驱动器只能执行简单的收缩和弯曲等原位变形。为了解决上述难题，本文基于液晶弹性体材料设计并成功制备出一种新型的电驱动环状驱动器系统，该系统由环状液晶弹性体/炭黑电驱动软驱动器和导电轨道组成。其中，环状驱动器由一个环状的液晶弹性体薄膜作为内环，其表面均匀分布着4个U形的碳黑导电区域层作为外层；导电轨道由一对具有锯齿状表面的铜片构成。该环状驱动器不需要连接有导线和电极元件，通过其表面的导电区域与导电轨道之间形成动态连接，形成完整的闭合回路，得到供电，并能够在50 V直流电压的驱动下以1.6 mm/s的速度向前滚动。