Design and simulation of MEMS Directional Microphone for battle Damage Assessments

MEMS Directional Microphone has found immense application in consumer products, medical applications and also defense applications. A directional microphone can be used in defense application where by the device can be mounted on an MAV and sent to enemy territory to record the conversation of the enemy and take strategic decisions based on the conversation. It can also be used in Battle Damage Assessment (BDA) applications where by the extent of damage because of the battle can be analyzed by finding the extent of pressure due to the attack and direction of the missile attack. In this paper the authors have designed and simulated a MEMS directional Microphone whose mechanical structure is inspired by the hearing organ of the parasitoid Ormia Ochracea. Eight different structures have been designed and simulated using COMSOL Multiphysics and Conventorware Turbo. On simulation the best frequency response for parallel plate structure is 15.7 kHz and for comb structure is 7.68 kHz. A detailed mathematical analysis has also been carried out where by the theoretical results have been compared with the simulated results. The MEMS directional microphone can be fabricated using SOIMUMPs or PolyMUMPs process for different structures designed in the paper.