To provide a piezoelectric actuator that is capable of giving sufficient deformation amount even when an area of electrodes arranged between stacked piezoelectric sheets is made smaller, and that has good energy efficiency and a fluid transferring device using the actuator.

A second part S is arranged that has the electrodes 24, 25 on the both sides of a part (a first part F) of the piezoelectric actuator 50 corresponding to the center of a pressure chamber 16. The electrodes 24, 25 of the second part S are positioned on the far side from the pressure chamber 16 in the thickness direction. When a voltage is impressed between the electrodes 24, 25, the piezoelectric sheets 54 to 56 sandwiched between the electrodes contract in the surface direction to bend the second part S upwards. This bend causes the first part F to be pushed upwards, causing the bottom side to be bent in a recessed shape and thereby increasing the capacity of the pressure chamber 16.

COPYRIGHT: (C)2004,JPO