Design of a Fully-Soft Lift-Assist Wearable Suit Powered by Flat Inflatable Artificial Muscles

The development of soft pneumatic actuators has expanded their applications due to flexibility and adaptability in wearable systems. Among these, flat inflatable artificial muscles (FIAMs) show a significant potential for wearable robots designed to assist body movements. While existing devices focus on supporting specific joints, an integrated system for multiple joints has not yet been realized. This study introduces a fully soft wearable suit incorporating FIAMs to assist lifting motions through combined actuation of the arms and back. The design and fabrication process of FIAMs are described, along with a force estimation model adapted for integration with the wearable suit. The experimental validation demonstrates robust and consistent performance of FIAMs under cyclic testing. The modular structure allows seamless integration into the wearable suit, enabling active assistance for targeted muscle groups. Human testing is conducted using weight-lifting tasks to evaluate the suit. Muscle activation and respiratory indices are measured to quantify the effects of the suit. The results demonstrate a partial reduction in metabolic cost expenditure, indicating the potential of this wearable suit for physical assistance in daily and occupational tasks.