Hybrid smart actuators fabricated using composites of carbon fibers and shape memory polymers have been extensively studied in recent years. However, relatively slow shape recovery has combined with the reset of shape deformation during cycles to restrict their practical use. An electrothermally reversible actuator based on carbon nanotube (CNT) composite yarn containing CNT fiber and thermoplastic polyurethane (TPU) resin with excellent shape memory was investigated in this paper. The combination of CNT yarn and TPU resin considerably amplified the contraction and stability. Large tensile stroke was obtained within 5 s (∼13.8%) while lifting a load that was ∼1905 times as heavy as the actuator. The generated contractive stress reached more than 33 MPa (corresponding to 120 g of the load) at a weight-to-yarn mass ratio of 28 400, which was about 30 times more than the shape recovery stress of shape memory polymer. In terms of the stability study, the process of annealing and contraction training was introduced. In addition, the quantitative relationship between temperature and contraction was also rigorously explored, which facilitated a more accurate and controllable contractile stroke. Great potential applications ranging from soft robots, wearable intelligent devices, and biomimetic devices to self-deployable structures in the aerospace field are likely to benefit from the advantages of low density, fast response without hysteresis, super flexible structure, as well as stitchability and large-scale production.

中文翻译：

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分层碳纳米管复合纱线的肌肉†

近年来，已经对使用碳纤维和形状记忆聚合物的复合材料制造的混合智能执行器进行了广泛的研究。但是，相对较慢的形状恢复与循环期间形状变形的复位相结合，从而限制了它们的实际使用。本文研究了一种基于碳纳米管（CNT）复合纱线的电热可逆致动器，该复合纱线包含具有良好形状记忆的碳纳米管和热塑性聚氨酯（TPU）树脂。CNT纱线和TPU树脂的结合极大地增强了收缩性和稳定性。在5 s（〜13.8％）内获得大的拉伸行程，同时提起的重量约为执行器的1905倍。在28400的重纱质量比下，产生的收缩应力达到33 MPa以上（相当于120 g的载荷），大约是形状记忆聚合物的形状恢复应力的30倍。在稳定性研究方面，介绍了退火和收缩训练的过程。此外，还严格探索了温度与收缩之间的定量关系，这有助于更准确和可控制的收缩冲程。从低密度，快速响应，无滞后，超柔韧性结构，可缝制性和大尺寸等优点，可能会受益匪浅，从软机器人，可穿戴智能设备和仿生设备到航空领域的可自行部署结构，应有尽有。规模化生产。介绍了退火和收缩训练的过程。此外，还严格探索了温度与收缩之间的定量关系，这有助于更准确和可控制的收缩冲程。从低密度，快速响应，无滞后，超柔韧性结构，可缝制性和大尺寸等优点，可能会受益匪浅，从软机器人，可穿戴智能设备和仿生设备到航空领域的可自行部署结构，应有尽有。规模化生产。介绍了退火和收缩训练的过程。此外，还严格探索了温度与收缩之间的定量关系，这有助于更准确和可控制的收缩冲程。从低密度，快速响应，无滞后，超柔韧性结构，可缝制性和大尺寸等优点，可能会受益匪浅，从软机器人，可穿戴智能设备和仿生设备到航空领域的可自行部署结构，应有尽有。规模化生产。