Robots of all kinds fascinate us, regardless of how big or how small they are. Now it seems that some of the brains at the Faculty of Engineering at Osaka City University have come up with a robotic fish that can swim around the tank powered by just a solid-polymer fuel cell, dubbed the “Power Tube”. The 10cm long robotic fish can swim, as well as dive and rise, owing to a joint at the front end of the fish. Initially the idea was to use a motor to get this little fish alive and kicking (swimming), but when they found out that the power consumption was about 1W, they switched to a magnet system that reduced the number to just 10mW. It seems that they’re planning to eventually develop a robotic fish that can swim for three consecutive days on a single charge. Maybe someday we’ll see such cool little fishes being mass produced and sold at your local toy store, eh? Video of this robotic fish in action is available after the jump.