Due to their high deformability, lightness, and safe interaction with the surrounding environment, flexible actuators are key ingredients in soft robotics technologies. Among these, electro-thermal actuators (ETAs), based on carbon nanotubes (CNTs), are used to generate agile movements when current is applied. The extent of movement is determined mostly by the coefficient of thermal expansion (CTE) of the materials arranged in a bi-/tri-layer structure. However, current CNT-based ETAs usually accomplish only simple actions with limited movements. In this work, we successfully developed novel ETAs that are capable of carrying out various controllable movements, such as extremely high bending curvature or unique actuations mimicking a wheel and a worm. These superior functionalities are achieved by adding a third layer or hinges composed of a thermo-responsive shape memory polymer (SMP) onto a bi-layer CNT-kapton ETA. To predict the unique movements of the “triangle” and “worm” actuators, finite element simulations were performed. The combination of SMP and electro-thermal behavior demonstrates its potential for applications in the field of soft actuators and robotics.

中文翻译：

---

由形状记忆聚合物和碳纳米管组成的预编程三层电热执行器。

由于其高度的可变形性，轻便性以及与周围环境的安全交互作用，柔性执行器是软机器人技术中的关键要素。其中，基于碳纳米管（CNT）的电热致动器（ETA）用于在施加电流时产生敏捷运动。运动程度主要由双层/三层结构中排列的材料的热膨胀系数（CTE）决定。但是，当前基于CNT的ETA通常只能完成动作有限的简单动作。在这项工作中，我们成功开发了新颖的ETA，它们能够执行各种可控的运动，例如极高的弯曲曲率或模仿轮子和蜗杆的独特驱动。通过将由热响应形状记忆聚合物（SMP）组成的第三层或铰链添加到双层CNT-kapton ETA上，可以实现这些优越的功能。为了预测“三角形”和“蜗杆”执行器的独特运动，进行了有限元模拟。SMP和电热行为的结合展示了其在软执行器和机器人技术领域的应用潜力。