Abstract

Pneumatic muscle fibers (PMFs) are a type of pneumatic artificial muscles (PAMs) with millimeter-scale diameter, which show great power to be a soft actuator under injecting the compressed fluid into its bladder. In this paper, the pressurized PMF was considered and investigated as a spring system due to the active contraction capability. The stiffness and variable stiffness characteristics of pressurized PMFs were theoretically investigated by utilizing a non-linear quasi-static model. Experiments were conducted to validate the theoretical model, and the experimental results have good agreement with the model predictions. A variable stiffness composite which was embedded with PMFs into the soft elastomer was presented and experimented to explore the potential adaptive shape-changing behaviors. The composite presented in this paper consists of 16 PMFs with the linear array distribution and two rectangular plates were used to support the PMFs. By taking advantage of the variable stiffness characteristics of pressurized PMFs, the presented composite shows the capability of varying stiffness partly and the shapes of the presented composite can change flexibly.

摘要

气动肌肉纤维 (PMF) 是一种直径为毫米级的气动人造肌肉 (PAM)，在将压缩流体注入膀胱的情况下，它显示出强大的动力作为软致动器。在本文中，由于主动收缩能力，加压 PMF 作为弹簧系统被考虑和研究。利用非线性准静态模型从理论上研究了加压 PMF 的刚度和变刚度特性。对理论模型进行了实验验证，实验结果与模型预测吻合较好。提出了一种将 PMF 嵌入软弹性体中的可变刚度复合材料，并进行了实验以探索潜在的自适应变形行为。本文提出的复合材料由 16 个线性阵列分布的 PMF 组成，两个矩形板用于支撑 PMF。通过利用加压PMF的可变刚度特性，所提出的复合材料显示出部分改变刚度的能力，并且所提出的复合材料的形状可以灵活变化。