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

Abstract

The sensitivity and the fundamental frequency of membrane with central mass (embossment) were analytically evaluated. Two different previously developed model (named as M1 and M2) of center embossment diaphragm were considered to obtain results. According to the results, it was noted that M1 structure shows higher sensitivity and displacement compared to M2. On the other hand, M2 structure provide more linearity on central deformation of membrane from applied pressure due to smaller displacement M1 counterpart. Moreover, frequency response of two structure is different for thinner embossment; however, this difference reduces for thicker embossment. As a result, the non-uniform structure of M2 model shows more flexibility on designing the sensors due to more geometrical parameters and provide more deformation linearity for effective detection of pressure. It was understand that compared with the conventional circular diaphragm (CD) structure used by Fabry-Perot interferometers (FPI) sensors, non-uniform structure provides extra geometrical parameters to tune the device performance and resulting in an enhanced design flexibility of the sensor structure.