Steering mechanism and swimming experiment of micro mobile robot in water

Recently many micro robots have been proposed for various purposes due to the advances of the precise process technology, and further progress in t h s field is expected.'11[21 One of the features that a micro robot has is a good possible advantage to work in a very small space. For instance in terms of medical technology a common application is to perform a delicate surgical operation supported by using micro machines thus avoiding unnecessary incisions. For an industrial application the use of micro robots is also proposed to maintain factory pipelines. As well as the medical case, the use of micro robots can help to avoid dismantling and reassembling. Micro robots can restrict their work to affected part or the breakdown spot and do not give unnecessary influence on their surroundings. Mother machine is the kind of robot that transports such micro robots and micro modules for accurate local work and operation in a very small Following the concept, we have aimed to develop a micro mobile robot. "A Study on In-Pipe Inspection Robot", a former research report is an advancement in this field.['] However this robot has two problems yet to be solved. 1) The robot may scratch the inside of the pipes because the propulsion mechanism involves physical contact with the inside of the pipes to move forward. 2) It is dependent on the condition of the inside surface of the pipes if the robot can move or not. As usual pipes are filled with some fluid. Fluid gives an even environment irrespective of the shape or the condition of pipes. Therefore, adopting the principle of movement which utilizes the fluid force, the robot can maneuver as far as the space is filled with some viscous fluid.Ls1 "Mechanism and Swimming Experiment of Micro Mobile Robot in Water,[6" our recent research report describes such a robot. The robot devised in the former research uses fins for propulsion.[61 The mechanism and principle proved effective both theoretically and experimentally. In addition, we examined the downsizing considering the Reynolds number, and we obtained the result that the robot could be minimized down to a few millimeter. The robot, however, has only 1 degree of freedom(D. 0. F.) in its propulsion. Therefore, the robot can not make proper motion when it meets obstacles or it comes to a junction. In t h s paper, we propose a prototype micro mobile robot with a new steering mechanism, which has 2 D. 0. F.. As well as the former 1 D. 0. F. robot, it is important that the simpler the mechanism and structure and the fewer the actuators, the better in terms of minimizing the robot in the future.