Fabrication and reliability testing of a MEMS piezoelectric acoustic sensor for applications in harsh environments

Abstract

The reliability of microelectromechanical system (MEMS) based piezoelectric acoustic sensors is important for a wide range of applications for environmental monitoring, medical diagnostics, and aerospace perspectives. These sensors must have long-term durability and stable performance under a variety of environmental conditions. This article includes a comprehensive framework for assessing the reliability of MEMS piezoelectric acoustic sensors with a focus on mechanical, electrical and thermal stability. The device comprises a zinc oxide layer (ZnO) between two metal electrodes, with a thin silicon dioxide film and micropaths worn on a glass substrate. The sensitivity and resonance frequency for this device were obtained at 203 μV/Pa and 78.9 kHz, respectively. The most critical factors evaluated include layer adhesion, substrate bonding strength of 8.9 MPa, a current bearing capacity of 91 mA, and thermal handling ability up to 600 °C. All of these aspects are important for determining the robustness and consistency of the sensor in performance.