Feng Xiaming, Li Sarah, Fan Jizhou, Li Guoqiang
Department of Mechanical and Industrial Engineering, Louisiana State University, Baton Rouge, LA, 70803, USA.
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA.
Sci Rep. 2025 Mar 12;15(1):8537. doi: 10.1038/s41598-025-92637-x.
Herein, we report hybrid fibrous artificial muscles with reversible actuation, i.e., expansion upon cooling and contraction upon heating, under external compression. Although many fibrous polymeric artificial muscles by twist insertion in precursor fibers have been developed, most of them cannot reversibly actuate without an external tensile load. While heterochiral Nylon muscles can reversibly actuate under external compressive load, the compressive stress applied is low (0.078 MPa). In this study, we inserted pre-tensioned polymeric fibers with reversible actuation into pre-compressed helical metallic spring and obtained hybrid fibrous artificial muscles. We employed two types of two-way shape memory polymers, one type of fishing line artificial muscle, and seven types of helical springs in preparing seven types of hybrid muscles. A structural mechanics model was developed, and numerical simulation was conducted to evaluate the effect of the design parameters on the actuation strain. It is found that all the hybrid muscles were free-standing (reversibly actuate without external load) and beyond free-standing (reversibly actuate under external compression load). As an example, one hybrid muscle actuated reversibly under 24 MPa compressive stress without buckling. We expect that this study will open new opportunities for the use of fibrous artificial muscles as linear actuators in soft robotics or other applications that need reversible actuation under external compression.
在此，我们报道了一种混合纤维人工肌肉，其在外部压缩下具有可逆驱动功能，即冷却时膨胀，加热时收缩。尽管已经开发出许多通过在前体纤维中插入捻度制成的纤维状聚合物人工肌肉，但其中大多数在没有外部拉伸载荷的情况下无法实现可逆驱动。虽然异手性尼龙肌肉在外部压缩载荷下可以可逆驱动，但其施加的压应力较低（0.078兆帕）。在本研究中，我们将具有可逆驱动功能的预拉伸聚合物纤维插入预压缩的螺旋金属弹簧中，从而获得了混合纤维人工肌肉。在制备七种类型的混合肌肉时，我们使用了两种类型的双向形状记忆聚合物、一种类型的钓鱼线人工肌肉和七种类型的螺旋弹簧。建立了结构力学模型，并进行了数值模拟，以评估设计参数对驱动应变的影响。结果发现，所有的混合肌肉都是自立式的（无需外部载荷即可可逆驱动），甚至超越了自立式（在外部压缩载荷下可逆驱动）。例如，一种混合肌肉在24兆帕的压应力下可逆驱动且不会发生屈曲。我们期望这项研究将为纤维人工肌肉在软机器人或其他需要在外部压缩下进行可逆驱动的应用中作为线性致动器的使用开辟新的机会。
