Behboodi A, DeSantis C, Lubsen J, Lee S C K
Annu Int Conf IEEE Eng Med Biol Soc. 2020 Jul;2020:4930-4935. doi: 10.1109/EMBC44109.2020.9176332.
To increase the acceptability of exoskeletons, there is growing attention toward finding an alternative soft actuator that can safely perform at close vicinity of the human body. In this study, we investigated the capability of the dielectric elastomer actuators (DEAs), for muscle-like actuation of rehabilitation robots. First, an artificial skeletal muscle was configured using commercially available stacked DEAs arranged in a 3x4 array of three parallel fibers consisting of four DEAs connected in series. The shortening and force generation capabilities of this artificial muscle were then measured. An alternate 3x5 version of this muscle was mounted on the forearm of an upper extremity phantom model to actuate its elbow joint. The actuation capability of this muscle was then tested under various tensile loads, 1 N to 4 N, placed at the center of mass of the forearm+hand of the phantom model. The active range of motion and angular velocity of the phantom model's tip of the hand were measured using a motion capture system. The 3×4 artificial muscle produced 30.47 N of force and 5.3 mm of maximum shortening. The 3x5 artificial muscle was capable of actuating the elbow flexion 19.5º with 16.2 º/s angular velocity in the sagittal plane, under a 1 N tensile load. The active range of motion was substantially reduced as the tensile loads increased, which limits the capability of these muscles in the current upper extremity exoskeleton design.
为了提高外骨骼的可接受性，人们越来越关注寻找一种能够在人体附近安全运行的替代软驱动器。在本研究中，我们研究了介电弹性体驱动器（DEA）用于康复机器人肌肉样驱动的能力。首先，使用市售的堆叠式DEA构建人工骨骼肌，这些DEA排列成3×4阵列，由三根平行纤维组成，每根纤维由四个串联的DEA连接而成。然后测量了这种人工肌肉的缩短和力产生能力。将这种肌肉的另一种3×5版本安装在上肢模型的前臂上，以驱动其肘关节。然后在1 N至4 N的各种拉伸载荷下，将其放置在模型前臂+手部的质心处，测试这种肌肉的驱动能力。使用运动捕捉系统测量模型手部尖端的主动运动范围和角速度。3×4人工肌肉产生了30.47 N的力和5.3 mm的最大缩短量。在1 N拉伸载荷下，3×5人工肌肉能够在矢状面内以16.2°/s的角速度驱动肘关节屈曲19.5°。随着拉伸载荷的增加，主动运动范围大幅减小，这限制了这些肌肉在当前上肢外骨骼设计中的能力。
