Wireless power transfer to moving ornamental robot fish in aquarium

We have constructed an underwater wireless power transfer system for the swimming robot fish using a coupled resonator WPT technique. The WPT systems are usually affected by dielectric material, the resonant frequency being shifted, and the power transfer loss being increased. By use of the primarily magnetic coupling, we have tried to realize a system that is hardly affected by the water. In addition, we have devised the resonator structure and the way of coil winding aiming at distribution everywhere in the aquarium. Then, a switching regulator for the power supply has contributed to improve the efficiency of the system.