Design and modeling a resonance humidity sensor

Microelectromechanical systems (MEMS) technology has enabled the realization of microsensors with the advantages of low power consumption, compact size, batch fabrication, and increased reliability. Humidity microsensors, which are fabricated using MEMS technology, have a wide range of applications in the industry and consumer products. In this paper, we investigate a humidity resonance microsensor with an activated alumina layer as a humidity absorber layer. The microsensor consists of a piezoelectric microcantilever, which is modeled using the Euler-Bernoulli beam theory to study the humidity absorption of the alumina layer based on the experimental results and the performance of the microsensor. The results show a humidity coverage of 0 to 70% with 370 (Hz/%RH) sensitivity. The first-mode resonant frequency of the microcantilever varies from 285 kHz to 249 kHz and the second-mode resonant frequency of the microcantilever varies from 1800 kHz to 1550 kHz. Also, the maximum deflection of the microcantilever increase to 400 nm in 70% relative humidity.

Keywords:

Piezoelectric Microcantilever , Humidity Microsensor , Activated alumina