Modelling and Design Optimization of a Soft-exosuit for Wearable Assistive Devices

Recent advancements in soft-robotic technologies provide a novel paradigm for designing wearable assistive devices (exosuits), making them comfortable, safe, and offering an enhanced range of motion. However, modeling these nonlinear actuation technologies is challenging, particularly due to complex interaction mechanics with the body. As a result, current studies often investigate actuation performance in isolation, which leads to poor translation in wearable applications. This work presents the modeling and design optimization of a soft-exosuit for assisting the motion of the index finger. We modelled both the exosuit and finger using a hybrid multibody toolbox and included their interaction mechanics. The optimal exosuit design for maximum bending of the finger joints resulted in a narrow exosuit base thickness compared to its tip. Moreover, we compared the influence of the objective function on the design of the exosuit. Our results show that it is essential to include interaction mechanics when evaluating actuation performance in these scenarios. The proposed modelling approach can be extended to designing optimal exosuits for other joints of interest.