Analysis of Linearity and Frequency Response of a New Piezoelectric Flextensional Actuator Using a Homodyne Interferometer and the J1-J4Method

Piezoelectric transducers are widely used in high resolution positioning systems, compact ultrasonic motors and vibration suppressors. In this work it is described the experimental characterization of a new flextensional piezoactuator designed by the topology optimization method. Using a homodyne Michelson interferometer and applying the J₁-J₄ method for signal demodulation, which provides a linear and direct measurement of dynamic optical phase shift independently of fading, the nanometric displacements of points on the piezoactuator surface were determined. Linearity and frequency response of the flextensional piezoactuator were evaluated up to 50 kHz, beyond the first resonance frequency of its PZT-5A piezoceramic. To confirm the observed frequencies of resonance it was also utilized an impedance analyzer to measure the magnitude and phase of the piezoactuator admittance