Abstract text

By resistor attached by a piezoelectric element, measurement with high accuracy is possible by strain of the piezoelectric element and there is not a trouble by a short, a piezoelectric actuator, the piezoelectric element and a positioning device therewith. The piezoelectric actuator includes; a piezoelectric element which is formed into an arbitrary shape, polarized in an arbitrary direction, and includes electrodes provided on at least two surfaces opposed in a thickness direction thereof; a driver power supply for applying a voltage between the electrodes to generate strain in the piezoelectric element; a driver power supply for applying a voltage to generate strain in the piezoelectric element; resistors provided on the electrodes through intermediation of insulators; and a displacement detection device connected with the resistors; The electrodes of the piezoelectric element on which the resistors are provided are set at a ground potential.