Zhang Qingqing, Xue Yuxuan, Zhao Yafei, Zou Kehan, Yuan Wenbo, Tian Yuqing, Chen Jiaming, Chen Jiangcheng, Xi Ning
Department of Industrial and Manufacturing System Engineering, The University of Hong Kong, Hong Kong SAR, China.
Sci Rep. 2024 Feb 27;14(1):4710. doi: 10.1038/s41598-024-55405-x.
A rotary motor combined with fibrous string demonstrates excellent performance because it is powerful, lightweight, and prone to large strokes; however, the stiffness range and force-generating capability of twisted string transmission systems are limited. Here, we present a variable stiffness artificial muscle generated by impregnating shear stiffening gels (STGs) into a twisted string actuator (TSA). A high twisting speed produces a large impact force and causes shear stiffening of the STG, thereby improving the elasticity, stiffness, force capacity, and response time of the TSA. We show that at a twisting speed of 4186 rpm, the elasticity of an STG-TSA reached 30.92 N/mm, whereas at a low twisting speed of 200 rpm, it was only 10.51 N/mm. In addition, the STG-TSA exhibited a more prominent shear stiffening effect under a high stiffness load. Our work provides a promising approach for artificial muscles to coactivate with human muscles to effectively compensate for motion.
旋转电机与纤维绳相结合表现出优异的性能，因为它功率大、重量轻且易于产生大冲程；然而，绞合绳传动系统的刚度范围和力产生能力是有限的。在此，我们展示了一种通过将剪切增稠凝胶（STG）浸渍到绞合绳致动器（TSA）中而产生的可变刚度人工肌肉。高扭转速度会产生较大的冲击力并导致STG的剪切增稠，从而提高TSA的弹性、刚度、力承载能力和响应时间。我们表明，在4186转/分钟的扭转速度下，STG - TSA的弹性达到30.92牛/毫米，而在200转/分钟的低扭转速度下，仅为10.51牛/毫米。此外，STG - TSA在高刚度负载下表现出更显著的剪切增稠效果。我们的工作为人工肌肉与人类肌肉共同激活以有效补偿运动提供了一种有前景的方法。
