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. 2021 Jan 1:7:1.
doi: 10.1038/s41378-020-00227-w. eCollection 2021.

Design and implementation of a jellyfish otolith-inspired MEMS vector hydrophone for low-frequency detection

Renxin Wang  1 , Wei Shen  1 , Wenjun Zhang  1 , Jinlong Song  1 , Nansong Li  2 , Mengran Liu  3 , Guojun Zhang  1 , Chenyang Xue  1 , Wendong Zhang  1
Affiliations

Design and implementation of a jellyfish otolith-inspired MEMS vector hydrophone for low-frequency detection

Renxin Wang et al. Microsyst Nanoeng. .

Abstract

Detecting low-frequency underwater acoustic signals can be a challenge for marine applications. Inspired by the notably strong response of the auditory organs of pectis jellyfish to ultralow frequencies, a kind of otolith-inspired vector hydrophone (OVH) is developed, enabled by hollow buoyant spheres atop cilia. Full parametric analysis is performed to optimize the cilium structure in order to balance the resonance frequency and sensitivity. After the structural parameters of the OVH are determined, the stress distributions of various vector hydrophones are simulated and analyzed. The shock resistance of the OVH is also investigated. Finally, the OVH is fabricated and calibrated. The receiving sensitivity of the OVH is measured to be as high as -202.1 dB@100 Hz (0 dB@1 V/μPa), and the average equivalent pressure sensitivity over the frequency range of interest of the OVH reaches -173.8 dB when the frequency ranges from 20 to 200 Hz. The 3 dB polar width of the directivity pattern for the OVH is measured as 87°. Moreover, the OVH is demonstrated to operate under 10 MPa hydrostatic pressure. These results show that the OVH is promising in low-frequency underwater acoustic detection.

Keywords: Engineering; Physics.

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Conflict of interest statement

Conflict of interestThe authors declare that they have no conflict of interest.

Figures

Fig. 1
Fig. 1. Microstructure models of auditory organs of pectis jellyfishes and OVH.
a Auditory organs of pectis jellyfishes, b OVH with an otolith-shaped cilium and cross beam; b is the width of the beam, t is the thickness of the beam, l is the length of the beam, w is the half-width of the mass square, h is the height of the rod, d is the radius of the rod, R is the outer radius of the sphere, and r is the inner radius of the sphere.
Fig. 2
Fig. 2. Analysis of the influence of the structure parameters on the resonance frequency and stress.
a Mechanical analysis of the structure; b relationship of the resonance frequency and various structure parameters; c relationship of the maximum stress on the beam and various structure parameters.
Fig. 3
Fig. 3. Simulation and comparison of the stress on the microstructures.
a Stress nephogram on the cross beam of the OVH when external pressure is applied on the cilium along the X-direction. b Stress distributions on the beams of various structures. Values of the X-axis indicate the distance of the site on the beam from the starting point.
Fig. 4
Fig. 4. Stress nephogram under 60 g shock along diverse directions.
a Along the X-direction; b along the Z-direction. The maximum stress on the beam could be extracted as 115.8 MPa along the X-direction and 12.5.
Fig. 5
Fig. 5. Sketch of the microfabrication process.
(1) Thermal oxidation; (2) 1st lithography, Etch SiO2 with 40 nm residue; (3) Boron light implantation, remove photoresist; (4) 2nd lithography, Boron heavy implantation; (5) Remove surface SiO2, anneal, remove photoresist; (6) Sputter, 3rd lithography, etch the metal, anneal to form Ohm contact; (7) 4th lithography, forward shallow etch; (8) 5th lithography, forward through etch; (9) 6th lithography, backside through etch, release the structure.
Fig. 6
Fig. 6. Measurement results of the OVH.
a Microscopy photograph of the cross-beam microstructure. Cross beam, piezoresistors, metal lines, and shallow groove can be seen; b picture of an otolith-shaped cilium mounted on a beam; c picture of the chip on the PCB and in the shell; the otolith-shaped cilium has been mounted vertically on the center of the cross beam; d receiving sensitivity–frequency response curve; e directivity pattern at 100 Hz with 3 dB polar width of the OVH at 87°; f setup of the 10 MPa hydrostatic pressure measurement; g otolith-shaped microstructure after the 10 MPa test; h data acquisition under 10 MPa
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References

    1. Testa C, Greco L. Prediction of submarine scattered noise by the acoustic analogy. J. Sound Vib. 2018;426:186–218. doi: 10.1016/j.jsv.2018.04.011. - DOI
    1. McConnel JA. Analysis of a compliantly suspended acoustic velocity sensor. J. Acoust. Soc. Am. 2003;113:1395–1405. doi: 10.1121/1.1542646. - DOI - PubMed
    1. Yildiz S, Dorman LM, Kuperman WA. Using hydrophones as vector sensors. J. Acoust. Soc. Am. 2014;135:2361–2364. doi: 10.1121/1.4877778. - DOI
    1. Ma R, Zhang WT, Li F. Two-axis slim fiber laser vector hydrophone. IEEE Photon. Techol. Lett. 2011;23:335–337. doi: 10.1109/LPT.2011.2104413. - DOI
    1. Di Iorio L, Gervaise C, Jaud V. Hydrophone detects cracking sounds: non-intrusive monitoring of bivalve movement. J. Exp. Mar. Biol. Ecol. 2014;432:9–16.