MEMS Underwater Directional Acoustic Sensor in Near Neutral Buoyancy Configuration

Sensors

Fabio Alves¹  Gamani Karunasiri¹  Leland McCarty¹  Renato Rabelo¹  Jaehyun Park¹ 

[1] Naval Postgraduate School, Monterey, CA 93943, USA;

关键词: neutral buoyancy;    MEMS acoustic sensor;    directional acoustic sensor;    underwater;   

DOI  :  10.3390/s22041337

来源: DOAJ

【 摘 要 】

A MEMS directional acoustic sensor housed in an air cavity and operated underwater in a near-neutral buoyancy configuration is demonstrated. The sensor consists of two wings connected by a bridge and attached to a substrate by two centrally mounted torsional legs. The frequency response showed two resonant peaks corresponding to a rocking mode (wings moving in opposite directions) and a bending mode (wings moving in the same direction). Initial tests of the sensor using a shaker table showed that the response is highly dependent on the vibration direction. In air, the sensor showed a maximum sensitivity of about 95 mV/Pa with a cosine directional response. Underwater, the maximum sensitivity was about 37 mV/Pa with a similar cosine directional response. The measured maximum SNR was about 38 dB for a signal generated by a sound stimulus of 1 Pa when the sensor is operated near the bending resonance. The results indicate that this type of MEMS sensor can be operated in a near-neutral buoyant configuration and achieve a good directional response.

【 授权许可】

Unknown