Design and analysis of the next generation Ormia differential microphone

The design and analysis of a biologically-inspired differential microphone diaphragm is presented in this thesis.;The current generation differential microphone diaphragm is designed based on the previous studies of the unique directional hearing mechanism in the ears of the fly, Ormia ochracea. The objective of the current design is to achieve a differential microphone diaphragm that has high sensitivity and essentially inaudible noise. The finite element software ANSYS is used to design the diaphragm structure. The diaphragm design employs two types of sensing methods: capacitive sensing and optical sensing. A reliable and convenient design process is developed to transfer the geometry from the finite element model in ANSYS to the silicon fabrication software L-Edit.;A simple lumped-mass model of the diaphragm demonstrates the principles of the diaphragm's structural acoustic response. The simple lumped-mass model takes into account the effects of the fluid domain under the diaphragm and exhibits its significant contribution on the diaphragm response. The finite element model extended from the simple lumped-mass approach enables the structural acoustic analysis to account for the complex motion of the diaphragm. The finite element software COMSOL is used to develop a model for analyzing the diaphragm response including the effects of the air in the back-volume.