Self-adaptive detachable pneumatic soft actuators using uniformly distributed temporary-bonding-fasteners for wearable applications

Human skin, especially the skin above rotating joints, has numerous creases and folds, so it can stretch and shrink with the movement of the musculoskeletal system. When we bend our fingers or elbows where there are joints, not only the rotating of bone joints occurs but also obvious stretching of the covered skin. However, most designs of soft actuators for wearable rotation-assistance of joints do not take into account these bending and stretching coupled deformations but focus only on the bending deformations. This situation results in different degrees of buckling of soft actuators when bending with joints due to inconsistencies in deformation. This study demonstrates detachable pneumatic soft actuators (DPSAs) in a single design for wearable fabrics capable of generating self-adaptive bending and extending deformation when rotating the joint. The DPSA is that of a pneumatic soft linear actuator with temporary bonding fasteners uniformly distributed to one side of the soft actuator. The bonding fasteners enable the DPSA to easily attach to the stretchable fabrics and further to conformably fit the joints of the human body. The self-adaptability of DPSAs enables the fabrics to not only actively rotate the human joints but also passively accommodate large skin stretches, without buckling even at large offset distances. Moreover, DPSAs in a single design are capable of good interchangeability and reusability supported by temporary bonding fasteners. Applications for both robotic glove and elbow assistance are finally demonstrated by utilizing identical DPSAs.