Soft actuators, made from soft materials, offer a safer alternative to rigid robots for use on hand rehabilitation devices. A current challenge is to ensure these actuators comply with human finger morphology. To gain better insights into actuator mechanics when worn on and interacting with human fingers, combining physical experiments with simulation approaches is necessary. However, no simulation has been implemented for finger-actuator interactions. This letter proposes a new joint modular soft actuator designed to comply with a dummy finger joint. The new actuator has a dual function design for increasing axial elongation during bending, facilitating compliance with finger morphology. In addition, a novel FEM for the new actuator's interaction with the dummy finger joint (dummy joint-soft actuator complex) is developed and used with physical experiments for evaluating actuator performance. Results show that the new design increases the dummy joint's bending range while exerting smaller contact forces on the joint. Even when the joint is blocked at specific bending angles, the actuator remains compliant to finger morphology. This research is a significant advancement in soft actuator design for hand rehabilitation, emphasizing the interaction between human fingers and soft actuators.

中文翻译：

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双功能关节模块化软执行器的开发及其使用新型假手指关节软执行器复杂模型的评估

由软材料制成的软执行器为手部康复设备上的刚性机器人提供了更安全的替代方案。当前的挑战是确保这些执行器符合人类手指形态。为了更好地了解执行器佩戴在人类手指上并与手指交互时的力学原理，有必要将物理实验与模拟方法相结合。然而，尚未对手指致动器交互进行模拟。这封信提出了一种新的关节模块化软执行器，旨在符合虚拟手指关节的要求。新型执行器具有双重功能设计，可增加弯曲过程中的轴向伸长率，有助于符合手指形态。此外，还开发了一种用于新执行器与虚拟手指关节（虚拟关节-软执行器复合体）相互作用的新型有限元模型，并通过物理实验来评估执行器性能。结果表明，新设计增加了假人关节的弯曲范围，同时对关节施加更小的接触力。即使当关节在特定的弯曲角度被阻挡时，执行器仍然符合手指形态。这项研究是手部康复软执行器设计的重大进步，强调了人类手指和软执行器之间的相互作用。