School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
Alan G. MacDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, TX 75080.
Proc Natl Acad Sci U S A. 2024 Oct 8;121(41):e2412288121. doi: 10.1073/pnas.2412288121. Epub 2024 Sep 30.
Biomimetic actuation technologies with high muscle strokes, cycle rates, and work capacities are necessary for robotic systems. We present a muscle type that operates based on changes in muscle stiffness caused by volume expansion. This muscle is created by coiling a mechanically strong braid, in which an elastomer hollow tube is adhesively attached inside. We show that the muscle reversibly contracts by 47.3% when driven by an oscillating input air pressure of 120 kilopascals at 10 Hz. It generates a maximum power density of 3.0 W/g and demonstrates a mechanical contractile efficiency of 74%. The muscle's low-pressure operation allowed for portable, thermal pneumatical actuation. Moreover, the muscle demonstrated bipolar actuation, wherein internal pressure leads to muscle length expansion if the initial muscle length is compressed and contraction if the muscle is not compressed. Modeling indicates that muscle expansion significantly alters its stiffness, which causes muscle actuation. We demonstrate the utility of BCMs for fast running and climbing robots.
仿生驱动技术需要具有高肌肉行程、高循环速率和高工作能力，以满足机器人系统的需求。我们提出了一种基于肌肉硬度变化的肌肉类型，这种肌肉通过卷曲一个机械强度高的编织物来实现，其中一个弹性体空心管被粘在里面。我们展示了这种肌肉在 10 Hz 时，通过 120 千帕的振荡输入气压驱动，可以可逆地收缩 47.3%。它产生的最大功率密度为 3.0 W/g，机械收缩效率为 74%。这种肌肉的低压操作允许使用便携式热气动驱动器。此外，这种肌肉还表现出双极驱动，即如果初始肌肉长度被压缩，则内部压力会导致肌肉长度扩张，如果肌肉没有被压缩，则会导致肌肉收缩。模型表明，肌肉的膨胀会显著改变其硬度，从而导致肌肉的驱动。我们展示了 BCM 在快速奔跑和攀爬机器人中的应用。
