Transient response of piezoelectric thin-film vibration sensor under pulse excitation

We present an analytical model to describe the transient response of a piezoelectric thin-film vibration sensor under pulse excitation. The structure of the thin-film vibration sensor consists of four suspended flexural piezoelectric lead zirconate titanate-on-silicon beam transducers and a central seismic mass. The model takes into account the effect of device geometry and materials properties of the piezoelectric thin film. The relationships between the dynamic behavior and voltage sensitivity with the device's structure are established. It is found that with the increase of initial vibration magnitude U-0 and reciprocal time constant alpha (alpha=1/tau) of the excitation, the maximum voltage sensitivity increases, and the maximum output voltage decreases with the increase of the resonance frequency. When damping is taken into account, the output voltage of the device under pulse excitation is simply an exponentially decaying function of time. The results can be readily applied for design and fabrication of the on-chip vibration sensor or accelerometer.