Measurement of nonlinear piezoelectric coefficients using a micromechanical resonator

TL;DR

This paper presents a novel method to measure nonlinear piezoelectric coefficients using a micromechanical resonator, enabling better characterization of material behaviors in MEMS devices through harmonic detection at resonance.

Contribution

It introduces a new experimental approach for quantifying nonlinear piezoelectric properties in materials like aluminum nitride using resonator harmonic response.

Findings

Measured second-order piezoelectric coefficient of aluminum nitride: -(23.1±14.1)×10^{-22} m/V^2

Demonstrated detection of harmonics generated at large drive amplitudes

Proposed method enhances understanding of nonlinear behavior in MEMS materials

Abstract

We describe and demonstrate a method by which the nonlinear piezoelectric properties of a piezoelectric material may be measured by detecting the force that it applies on a suspended micromechanical resonator at one of its mechanical resonance frequencies. Resonators are used in countless applications; this method could provide a means for better-characterizing material behaviors within real MEMS devices. Further, special devices can be designed to probe this nonlinear behavior at specific frequencies with enhanced signal sizes. The resonators used for this experiment are actuated using a 1-$\mu$m-thick layer of aluminum nitride. When driven at large amplitudes, the piezoelectric layer generates harmonics, which are measurable in the response of the resonator. In this experiment, we measured the second-order piezoelectric coefficient of aluminum nitride to be $-(23.1\pm14.1)\times10^{-22}\ \mathrm{m/V^2}$.