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Abstract Thin films based on PbZr_1−xTi_xO₃and K_1−xNa_xNbO₃are increasingly being commercialized in piezoelectric MEMS due to the comparatively low drive voltages required relative to bulk actuators, as well as the facile approach to making sensor or actuator arrays. As these materials are incorporated into devices, it is critically important that they operate reliably over the lifetime of the system. This paper discusses some of the factors controlling the electrical and electromechanical reliability of lead zirconate titanate (PZT)-based piezoMEMS films. In particular, it will be shown the gradients in the Zr/Ti ratio through the depth of the films are useful in increasing the lifetime of the films under DC electrical stresses. 

Piezoelectric microelectromechanical systems (piezoMEMS) enable dense arrays of actuators which are often driven to higher electrical fields than their bulk piezoelectric counterparts. In bulk ceramics, high field driving causes internal heating of the piezoelectric, largely due to field-induced domain wall motion. Self-heating is then tracked as a function of vibration velocity to determine the upper bound for the drive levels. However, the literature is limited concerning self-heating in thin film piezoMEMS. In this work, it is shown that self-heating in piezoMEMS transducer arrays occurs due to domain wall motion and Ohmic losses. This was demonstrated via a systematic study of drive waveform dependence of self-heating in piezoMEMS arrays. In particular, the magnitude of self-heating was quantified as a function of different waveform parameters (e.g., amplitude, DC offset, and frequency). Thermal modeling of the self-heating of piezoMEMS using the measured hysteresis loss from electrical characterization as the heat source was found to be in excellent agreement with the experimental data. The self-heating model allows improved thermal design of piezoMEMS and can, furthermore, be utilized for functional heating, especially for device level poling.