Fabrication and characterization of PZT multilayer actuators

Abstract

Multilayer actuators with sixty 165-μm-layers (6.5 mm × 6.5 mm × 10 mm) of lead zirconate-titanate (PZT-4D) were made and tested to determine their possible use for low voltage electromechanical uses. These actuators were fabricated via tapecasting and cofired with integral platinum electrodes. After firing, external lead wires were attached for poling, testing, and final use. Such multilayers require <70 V to achieve drive fields of 10 V/mil rms (0.55 MV/m p-p). Piezoelectric coefficients (effective d33 of 263 pC/N, effective g33 ∼ 35 mV · m/N), electromechanical hysteresis (<10%), relative dielectric permittivity at 1 kHz of ∼ 1000, and dielectric dissipation (<0.01) are comparable to those measured on monolithic pieces. The field limit on reproducible actuator performance is >4 MV/m. The high capacitance of the actuators results in a measured transition from capacitive to inductive behavior at high frequency (∼850 kHz) as the actuator becomes electrically resonant with typical test leads.