Design and Optimization of MEMS-Based Four Beam Vector Hydrophone for Direction of Arrival

Abstract

Hydrophone, an acoustic sensor, used to pick up acoustic signals generated by different objects present in underwater. MEMS Vector Hydrophone is a recent advancement in the field of underwater acoustic sensors that provides the direction of the incoming acoustic signals. As the main sensing elements of these hydrophones are in micrometers hence light weight, which makes them useful for deployment in Autonomous Underwater vehicles (AUVs) and Remotely Operated Underwater Vehicles (ROVs). This paper presents simulation, modeling and design optimization of four beam MEMS Vector Hydrophone, using design modeler of ANSYS Workbench. This paper presents design optimization, stress, frequency, harmonic and electro-mechanical analysis of MEMS-based four beam Vector Hydrophone. Using ANSYS software design is optimized by changing important parameters to improve design and sensitivity that can be chosen for fabrication. Static structural analysis is performed on the structure for getting an optimized location for placing piezoresistors over cantilever beams. For better understanding of structural vibrations that can be induced in the Vector Hydrophone structure, the resonant frequencies of the structure were identified and quantified. The Receiving Voltage Sensitivity is −196.73 dB (0 dB = 1 V/µPa) which is further improved to −184.86 dB by design optimization (Xue et al. in Microelectron J 38:1021–1026, 2007 [1]). By incorporating pre-amplifier having a gain of 100, Voltage sensitivity further can be enhanced up to −156.73 dB (Hang et al. in Nano-Micro Lett 6:136–142, 2014 [2]).