The fabric-based pneumatic exosuit is now a hot research topic because it is lighter and softer than traditional exoskeletons. Existing research focused more on the mechanical properties of the exosuit (e.g., torque and speed), but less on its wearability (e.g., appearance and comfort). This work presents a new design concept for fabric-based pneumatic exosuits Volume Transfer, which means transferring the volume of pneumatic actuators beyond the garments profile to the inside. This allows for a concealed appearance and a larger stress area while maintaining adequate torques. In order to verify this concept, we develop a fabric-based pneumatic exosuit for knee extension assistance. Its profile is only 26mm and its stress area wraps around almost half of the leg. We use a mathematical model and simulation to determine the parameters of the exosuit, avoiding multiple iterations of the prototype. Experiment results show that the exosuit can generate a torque of 7.6Nm at a pressure of 90kPa and produce a significant reduction in the electromyography activity of the knee extensor muscles. We believe that Volume Transfer could be utilized prevalently in future fabric-based pneumatic exosuit designs to achieve a significant improvement in wearability.

翻译：基于织物的气动外衣因其比传统外骨骼更轻、更柔软而成为当前研究热点。现有研究主要聚焦于外衣的机械性能（如扭矩和速度），而较少关注其可穿戴性（如外观和舒适度）。本研究提出了一种基于织物的气动外衣的新设计概念——体积转移，即将气动执行器的体积从服装轮廓外部转移至内部。这一设计既能实现隐蔽外观，又能增大受力面积，同时保持足够的扭矩。为验证该概念，我们开发了一款用于辅助膝关节伸展的基于织物的气动外衣，其轮廓厚度仅为26毫米，受力面积几乎包裹半个腿部。通过数学模型和仿真确定外衣参数，避免了原型的多次迭代。实验结果表明，该外衣在90kPa压力下可产生7.6Nm扭矩，并显著降低膝伸肌的肌电活动。我们认为体积转移概念可广泛应用于未来基于织物的气动外衣设计中，以显著提升其可穿戴性。