Fabrication and evaluation of aluminum nitride based MEMS piezoelectric vibration sensors for large-amplitude vibration applications

In this work, we designed a novel structure to produce vibration sensors with a linear voltage output that are suitable for large-amplitude vibration applications. Specifically, the sensor structure featured a cylindrical proof mass attached to a diaphragm structure with eight release holes. Based on this structure and using a commercial eight-inch microelectromechanical system foundry process, aluminum nitride based piezoelectric vibration sensors were successfully fabricated. The produced piezoelectric gauge film and the mechanical properties and electrical performance of the fabricated vibration sensors were comprehensively evaluated. The results demonstrated that the fabricated vibration sensors presented center resonance values within the frequency range of 5–6 kHz and an acceleration responsivity of up to 460 mV/g. The measured nonlinearity of the sensors was less than 1% in the testing range of 10–50 g at 150 Hz. The mass fabrication of our high-performance large-amplitude vibration sensors is expected to support the realization of many advanced domestic and industrial applications, e.g., for the rational and economical monitoring of the safety of industrial and civil structures over time.