Fabrication of MEMS Directional Acoustic Sensors for Underwater Operation
Author
Espinoza, Alberto
Alves, Fabio
Rabelo, Renato
Da Re, German
Karunasiri, Gamani
Date
2020-02Metadata
Show full item recordAbstract
In this work, microelectromechanical systems (MEMS)-based directional acoustic sensors operating in an underwater environment are explored. The studied sensors consist of a free-standing single wing or two wings pivoted to a substrate. The sensors operate in a narrow frequency band determined by the resonant frequency of the mechanical structure. The electronic readout of the mechanical response is obtained using interdigitated comb finger capacitors attached to the wings. The characteristics of MEMS sensors immersed in silicone oil are simulated using finite element modeling. The performance of the sensors is evaluated both in air and underwater. For underwater testing and operation, the sensors are packaged in a housing containing silicone oil, which was specially developed to present near unity acoustic transmission. The measurements show that the resonant frequency of the sensors obtained in air shifts to a lower frequency when immersed in silicone oil, which is primarily due to the mass loading of the liquid. The peak sensitivity of the MEMS sensors is approximately 6 mV/Pa or −165 dB re 1 V/μPa, and the directional response shows a dipole pattern. The signal-to-noise ratio was found to be about 200 or 23 dB at 1 Pa incident sound pressure. The results show the potential of MEMS sensors to be used in underwater applications for sound source localization.
Description
The article of record as published may be found at https://doi.org/10.3390/s20051245
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.Collections
Related items
Showing items related by title, author, creator and subject.
-
Methodology to distinguish features in complex and congested underwater environments
Mitchelson, Matthew Arthur (Monterey, California: Naval Postgraduate School, 2016-06);The underwater community involves researchers who conduct various work and experiments below the surface of Earth’s oceans. Today’s high-frequency sonar limitations do not provide sufficient information for the underwater ... -
PACKAGING AND CHARACTERIZATION OF BIO-INSPIRED UNDERWATER MEMS DIRECTIONAL SOUND SENSOR
Espinoza Peyrot, Alberto Antonio (Monterey, CA; Naval Postgraduate School, 2019-06);The thin-line towed array hydrophones and vector sensors are commonly used to determine the bearing of sound sources in underwater environment. In this thesis, a MEMS-based directional underwater acoustic sensor (inspired ... -
FEASIBILITY OF UNDERWATER MEMS DF ACOUSTIC SENSOR FOR NARROWBAND DETECTION
Roberts, Jason (Monterey, California. Naval Postgraduate School, 2020-06);A microelectromechanical system (MEMS)–based directional sound sensor has been developed to operate both in air and underwater. The sensor consists of two wings that are attached to a substrate using two torsional legs ...