Mechanism and swimming experiment of micro mobile robot in water

This paper deals with a micro-mobile robot in water utilizing PZT(Pb(Zr, Ti)O₃) as an actuator. A robot driven by PZT requires a magnification mechanism and the effects of the resonance condition to enlarge the displacement of the PZT to some extent. In this paper, we show a prototype micro-mobile robot in water (double-fin-fish robot), which possesses a pair of fins and moves them symmetrically. Therefore, the momentum of this robot is canceled and the tendency to move straight ahead is improved. The size of the robot is 50 mm in length. We propose a structure for the magnification mechanism, which is made by the wire cut method. The magnification ratio is 326 geometrically. This robot has many possible applications, such as small pipeline inspections and biomedical fields