Microbial fuel cells (MFC) are expected as a type of electric power generation that does not depend on fossil fuel. Many challenges have been reported to increase the performance. However, there are few researches about MFC or MFC systems from mechanical device points of view. This research proposes and investigates a new idea to improve the performance by use of ultrasonic vibrations generated by piezo electronic devices. In this paper, possible effects of the ultrasonic vibrations are introduced, and a system structure for this application is discussed. As basic experiments, the effects of ultrasonic vibrations on phototrophic bacteria, are examined.