基于胆甾型液晶弹性体的机器人皮肤

This proposal aims to design and fabricate a stretchable "photonic skin" for robots. Unlike the prevailing "electronic skin", the photonic skin in this proposal maps the applied force and its distribution by straightforward color patterns. The skin is a film based on cholesteric liquid crystalline elastomers (CLCE) and mechano-sensitive chromophores or nanoparticles. When the film is pressed or stretched, the color of the film changes. The principle relies on the helical pitch change upon the external forces. Due to the involvement of mechano-sensitive chromophores (nanoparticles), pressure and strain could be differentiated. New cholesteric liquid crystalline elastomers with various chemical structures will be designed and synthesized. Different mechano-sensitive chromophores (nanoparticles) will be introduced into the CLCEs either by blending them into CLCEs or covalently attached to the CLCEs. Their ability to adjust the helical pitch of CLCEs will be characterized. The underlying mechanism will be investigated. The relationship between forces and color changes will be illustrated. Their performance as robot skin will be demonstrated. ..This project represents a new concept of robot skin. For all the artificial robot skin developed in the past, they were prepared by integrating thousands of tactile sensors into flexible substrates. Meanwhile, no robot skin uses color to signify external forces. The robot skin in this proposal is different. No traditional electronic or photonic tactile sensors are involved. The film itself is the sensor, visualizing the external forces continuously. No complex preparation steps are necessary. Meanwhile, the color signal is not affected by electronic or magnetic filed. As a novel intelligent film, the aimed material is also beneficial for a broad range of areas where pressure or strain monitoring is necessary.

本项目拟利用特殊力致变色薄膜制备机器人人工皮肤。设计并合成新型胆甾型液晶弹性体薄膜，筛选与之匹配的外力敏感组分，以物理共混或化学键合的方式引入到胆甾型液晶弹性体薄膜中，利用外力敏感组分调控胆甾型液晶的螺距，通过螺距变化导致的颜色变化赋予此新材料识别法向应力和拉伸力的功能,建立颜色变化与外力之间的定量关系，利用薄膜的颜色变化及图案来反映外界施力的大小和分布，为机器人人工皮肤设计与制备提供新材料新思路。本项目摒弃了目前采用复杂工艺在柔性基质上集成电子感应器阵列的主导路线。目标材料力学性能好，可拉伸变形，无需复杂工艺且可大面积制备。此种薄膜材料的成功开发，将极大的简化机器人人工皮肤的制备，并将为航空航天、医疗康复、海底探索、机械传感等诸多领域中压力和拉伸力的监测贡献一种新型智能响应材料。

本项目试图通过将胆甾型液晶弹性体与力致变色组分结合，探索制备无电子器件利用颜色变化来显示外力大小的方向的人工皮肤的可能性。.项目主要研究内容有二。一是设计合成对外力敏感的易于制备的胆甾型液晶弹性体；二是选择合适的力致变色组分并寻求合适的方法将其整合进液晶弹性体，从而得到具有力致变色功能的液晶弹性体。.重要结果及其科学意义如下：.1. 将动态共价键引入液晶弹性体， 通过简单的方法得到单畴的液晶弹性体，不仅有助于本项目的顺利进行，而且对促进液晶弹性体领域的发展具有重要意义。.2. 采用二硫键构筑液晶弹性体体系，克服了上述酯交换体系液晶基元选择受限的缺点，使得含酯键的液晶基元能够应用于可塑形液晶弹性体的制备，有利于此类型胆甾型弹性体的应用。.3. 将力致变色基团与液晶弹性体结合，得到了通过外力可以实现颜色变化的一种新材料，对于拓展液晶弹性体的应用具有一定的价值。