Robotic artificial muscles (RAMs) are promising power sources for medical fields such as surgical robotics. However, existing RAMs are challenged by scalability, material costs and fabrications. The nonlinear hysteresis in fluid-driven RAMs causes oscillations in open-loop systems. To circumvent these limitations, this letter introduces hydraulically soft microtubule artificial muscle (SMAM) that is low-cost and scalable, yet simple to fabricate. The SMAM, which only requires a flexible silicone microtube and a hollow micro-coil, is elongated or contracted under a fluid pressure. The SMAM presents an ideal candidate for flexible robotic systems such as endoscopic surgical robots. Experiments are conducted to characterize the SMAMs. Results show that the hysteresis profiles between the input syringe plunger position and output position are stable regardless of its configuration, as opposed to the highly variable responses for the tendon-sheath mechanisms. A new nonlinear model is developed to characterize the asymmetric hysteresis phenomena of the SMAM. Compared to the Bouc-Wen hysteresis models, the developed model presents a better capture of hysteresis. To demonstrate the muscle capability, a SMAMs-driven pulley and a flexible surgical arm are given. The new SMAM and its asymmetric hysteresis model are expected to provide a path for the development of rapidly efficient and low-cost soft actuators for use in flexible medical devices and surgical robotic systems.

中文翻译：

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用于医疗应用的软微管人造肌肉（SMAM）的设计，制作和滞后建模

机器人人造肌肉（RAM）是用于医学领域（如外科机器人）的有前途的动力源。然而，现有的RAM受到可伸缩性，材料成本和制造的挑战。流体驱动RAM中的非线性磁滞引起开环系统的振荡。为了规避这些限制，这封信介绍了价格低廉，可扩展但易于制造的液压软性微管人造肌肉（SMAM）。仅需要柔性硅树脂微管和中空微线圈的SMAM在流体压力下可以伸长或收缩。SMAM为柔性机器人系统（例如内窥镜手术机器人）提供了理想的选择。进行实验以表征SMAM。结果表明，与配置的腱鞘机制相比，无论针筒的配置如何，输入针筒柱塞位置和输出位置之间的磁滞曲线都是稳定的。开发了一个新的非线性模型来表征SMAM的非对称磁滞现象。与Bouc-Wen磁滞模型相比，开发的模型可以更好地捕获磁滞。为了展示肌肉功能，给出了SMAM驱动的滑轮和柔性手术臂。新的SMAM及其非对称磁滞模型有望为开发用于柔性医疗设备和手术机器人系统的快速有效，低成本的软执行器提供一条途径。开发了一个新的非线性模型来表征SMAM的非对称磁滞现象。与Bouc-Wen磁滞模型相比，开发的模型可以更好地捕获磁滞。为了展示肌肉功能，给出了SMAM驱动的滑轮和柔性手术臂。新的SMAM及其非对称磁滞模型有望为开发用于柔性医疗设备和手术机器人系统的快速有效且低成本的软执行器提供一条途径。开发了一个新的非线性模型来表征SMAM的非对称磁滞现象。与Bouc-Wen磁滞模型相比，开发的模型可以更好地捕获磁滞。为了展示肌肉功能，给出了SMAM驱动的滑轮和柔性手术臂。新的SMAM及其非对称磁滞模型有望为开发用于柔性医疗设备和手术机器人系统的快速有效，低成本的软执行器提供一条途径。