Fabrication process of bending-type smart artificial muscles using braiding technology and its application to soft mechanism with two bending units

Abstract McKibben artificial muscle is a fluid-driven soft actuator comprising sleeve fibres and a rubber tube, which contracts by fluid pressure. A part of the side of the artificial muscle is reinforced with a reinforcement material to suppress contraction in that area, thereby achieving the bending motion. In this study, we propose a novel fabrication process to realise bending-type smart artificial muscles (B-SAMs) that sense their curvature by using optical fibres as the reinforcement material. The optical fibre also serves as a curvature sensor owing to the attachment of a light emitter and light receiver on each end of the fibre. A braiding machine is employed to fabricate B-SAM, allowing the optical fibre to be integrated with the sleeve fibres to cover the rubber tube, rendering mass production easy. The versatility of the proposed method is demonstrated through fabricating and evaluating a soft mechanism with two bending units using this fabrication technique. The proposed simple and efficient fabricating process can promote the practical application of artificial muscles.