Directional Resonant MEMS Acoustic Sensor and Associated Acoustic Vector Sensor

Area of Science:

• Acoustic Engineering
• Micro-electromechanical Systems (MEMS)
• Sensor Technology

Background:

• Development of portable systems for detecting quiet or distant acoustic sources.
• Need for high-sensitivity acoustic sensors with precise direction-finding capabilities.

Purpose of the Study:

• To design, model, analyze, and evaluate a novel MEMS acoustic sensor.
• To develop and test an acoustic vector sensor array (AVS) utilizing the novel sensor.
• To assess the performance of the sensor and AVS in both laboratory and field conditions, including underwater environments.

Main Methods:

• Design and fabrication of a MEMS-based acoustic sensor operating at resonance.
• Integration of sensors into an acoustic vector sensor array (AVS).
• Experimental evaluation using various acoustic sources (tones, gunshots, drones) in lab and field settings.

Main Results:

• The MEMS acoustic sensor achieved high acoustic sensitivity (-84.6 dB re 1 V/μPa) and a maximum signal-to-noise ratio (SNR) of 88 dB.
• The AVS provided unambiguous 360-degree azimuthal coverage.
• Accurate acoustic direction of arrival determination with an average error within 3.5° in field experiments.

Conclusions:

• The developed MEMS acoustic sensor and AVS demonstrate significant potential for detecting and locating acoustic sources.
• The system's performance, including high sensitivity and directional accuracy, is suitable for various specific applications.
• The sensor's resonant frequency can be tuned for specific acoustic signature detection.