Abstract
A swimming micro fish robot whose size is as small as a killifish is useful to seek disaster victims in flood areas, because it can go into narrow spaces. In this study, two types of micro fish robots (each total length is about 50 mm) have been developed. One is a fish robot which moves its trunk and tail with small magnetic actuators composed of coils and neodymium magnets. Employing soft material for its tail fin has improved the robot's propulsion performance at an appropriate phase difference between two sets of actuators. As a result, this fish robot can swim considerably fast in water, though its power consumption is very small. In addition, it has been demonstrated that the fish robot can swim by supplying electric power from the authors' original small and lightweight direct-methanol fuel cells (named "Power Tube") with the aid of a voltage booster. Furthermore, it has been shown that another fish robot which moves its tail with an IPMC (ionic polymer-metal composite, notable as artificial muscle) actuator can swim smoothly in water, though its power consumption is considerably larger at present than the former fish robot.
