Comparison of Two Different Circular Diaphragm Models with Central Mass for MEMS Based FPI Pressure Sensor Performance Based on Sensitivity and Frequency Response

Yildiz F.

Sakarya Üniversitesi Fen Bilimleri Enstitüsü Dergisi, vol.25, no.3, pp.619-628, 2021 (Peer-Reviewed Journal) identifier


The sensitivity and the fundamental frequency of circular membrane with a central mass (embossment) were analytically evaluated for Fabry- Pérot interferometers (FPI) based pressure sensor. Two different previously developed model (named as M1 and M2, respectively in this study), which includes a diaphragm with center embossment, were considered to obtain results and performance of models were compared. Thickness of diaphragms were 5 µm and 10 µm with the radius of 300 µm, 500 µm,600 µm and 700 µm, respectively. According to the results, it was noted that diaphragm considering M1 model shows higher sensitivity and displacement compared to diaphragm considering M2 model. 155.15-102.87 nm/kPa and 149.5-39.7 nm/kPa sensitivity range were calculated for the diaphragm based on the M1and M2 model, respectively when 300 µm in radius and 5 µm thick diaphragm was used. Moreover, frequency response of diaphragm considering two different model is slightly different for thinner embossment; however, same frequency response was calculated for thicker embossment. For example, frequency range of 700 µm in radius and 10 µm was changes between 42-22.7 kHz and 42.2- 22.7 kHz when M1 and M2 model was considered. It was understand that compared with the conventional circular diaphragm (CD) model, non-uniform diaphragm with a central mass provides more geometrical parameters to tune the device performance (sensitivity) and it provides design flexibility on the sensor structure.