Origami enables the folding of objects into a variety of shapes. This paper presents a swimming robot using the folding and unfolding motion of a tabular origami. A squid-inspired jet propulsion mechanism is used to design an origami swimming robot. The swimming robot utilizes a pulsed-jet mechanism through the folding motion of the tubular origami structure, which could deform and undulate to provide propulsion for the swimming robot. The robot is incorporated in a stable body, while both swimming forward and steering are generated by the folding motion of the origami structure and undulating fins. An analytical model to investigate the jet propulsion mechanism to capture the relationship between the motor's speed and the generated thrust is developed. The prototype of the swimming robot is fabricated by 3D printing, and experiments verify the robot's components and assembly system. The results show that the swimming robot could achieve swimming forward by folding origami, which could provide unique advantages over other existing underwater propulsion technologies, including scalability and water treatment capabilities. The origami structure provides a novel and simple propulsion mechanism for the swimming robot here, and the mechanism promotes the development of a new class of independent swimming robots.
INTRODUCTIONSwimming robots can remote access most of the Earth's surface for a variety of environmental, archaeological, industrial, and scientific purposes [1][2][3]. Many practical applications for swimming robots in this setting include exploration and inspection tasks. In the past few decades, the growing demands for swimming applications have driven the research of swimming robots [4][5]. The way to propulsion is one of the essential features of underwater robots. After years of evolution, aquatic animals have different propulsion methods with high efficiency. The way they move and the streamlined shape can significantly reduce underwater resistance. Many bionic swimming robots are inspired by their biological counterparts [6][7][8][9]. Most underwater creatures oscillate or undulate through their fins that imitate the swinging or undulating mode to generate propulsion power. The undulating bionic underwater robot can drive its body to swing asymmetrical alternately on the left and This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.