Acoustically transparent electrochemical vector hydrophone

Abstract

The application discloses a kind of electrochemical vector hydrophone of sound transmission type, belong to underwater acoustic technical field, including sound transmission membrane, electrolyte, sound transmission channel, sensitive electrode, circuit and sealing shell;Sound transmission membrane is placed in the both sides of sound transmission channel;Electrolyte is used to provide the medium of electrochemical reaction, and sound wave can propagate in electrolyte;Sound transmission channel is filled with electrolyte inside, and sensitive electrode is embedded in the middle;Sensitive electrode includes a plurality of anode and a plurality of cathode, and electrolyte occurs electrochemical reaction in anode and cathode to generate current, and a plurality of flow holes are formed on electrode to make electrolyte pass smoothly;Circuit includes current-voltage conversion circuit and differential amplification circuit;Sealing shell, wrap inside structure and circuit of hydrophone, only expose sound transmission membrane, and internal gap is filled with insulating liquid.Sound wave signal is transmitted through sound transmission membrane, through sound transmission channel, acts on electrolyte near sensitive electrode, and causes the particle vibration of electrolyte near sensitive electrode.The application of very low frequency band is more reliable, and smaller in size.

Description

Technical Field

[0001] This invention belongs to the field of underwater acoustics technology, specifically relating to a sound-transmitting electrochemical vector hydrophone. Background Technology

[0002] Sound waves are currently the most effective carrier for transmitting information over long distances in the ocean, and a wealth of information can be obtained by detecting the sound field in the ocean. A hydrophone is a sensor that converts underwater acoustic signals into electrical signals. Compared to traditional scalar hydrophones, vector hydrophones can obtain not only scalar signals but also vector signals in the sound field, and have wide applications in underwater target tracking, sonar systems, distributed sensor networks, and ocean noise measurement.

[0003] The attenuation of underwater acoustic signals during propagation is positively correlated with the signal frequency; the higher the frequency, the faster the attenuation rate. Low-frequency underwater signals travel farther than high-frequency signals. Therefore, monitoring low-frequency and very low-frequency underwater target radiated noise is crucial for long-range target detection and localization. In recent years, with the continuous development and application of vibration damping and noise reduction technologies (such as anechoic tiles and wave-absorbing coatings) and underwater acoustic countermeasures technologies, the level of underwater target radiated noise has been continuously reduced. Therefore, low-frequency detection has become a development trend in underwater target detection. Electrochemical transducers possess the advantages of high sensitivity and low noise at low and very low frequencies, perfectly meeting the development needs of vector hydrophones.

[0004] Currently, vector hydrophones are mainly divided into inertial and differential pressure types. Differential pressure hydrophones utilize the finite difference principle of two or more acoustic pressure hydrophones to obtain gradient information. They have a simple structure and are easy to install, but operate at relatively high frequencies. Inertial hydrophones are typically co-vibration type, fixing the internal sensing element to a spherical or cylindrical shell and suspending it on a frame using flexible elements. The internal sensing element follows the overall vibration to acquire motion parameters, but installation is cumbersome, and the suspension method is not conducive to low-frequency extension. Another emerging type of inertial hydrophone uses a transparent acoustic structure with a ciliary sensor as the sensing element. The hydrophone base is fixed, and sound waves pass through the transparent shell and act on the sensing element, thus achieving direct measurement of particle acceleration. This type of hydrophone can be directly fixed to a mounting platform, making installation convenient and smaller, more suitable for hydrophone applications. Currently, its main drawback is low low-frequency sensitivity. Summary of the Invention

[0005] To address key issues such as low-frequency sensitivity, the main objective of this invention is to provide a transparent electrochemical vector hydrophone, comprising a transparent diaphragm, an electrolyte, a sound transmission channel, a sensitive electrode, a circuit, and a sealing shell. The transparent diaphragm is placed on both sides of the sound transmission channel. The electrolyte provides the medium for the electrochemical reaction, allowing sound waves to propagate. The sound transmission channel is filled with the electrolyte, with the sensitive electrode embedded in the center. The sensitive electrode includes several anodes and several cathodes; the electrolyte undergoes an electrochemical reaction at the anode and cathode to generate current, and the electrode has several flow holes to allow the electrolyte to pass through smoothly. The circuit includes a current-to-voltage conversion circuit and a differential amplifier circuit. The sealing shell encloses the internal structure and circuit of the hydrophone, exposing only the transparent diaphragm, and its internal gaps are filled with an insulating liquid. The underwater acoustic signal passes through the transparent diaphragm and the sound transmission channel, acting on the electrolyte near the sensitive electrode, causing the electrolyte particles near the sensitive electrode to vibrate.

[0006] To achieve the aforementioned objective, the present invention employs the following technical solution:

[0007] A sound-transparent electrochemical vector hydrophone includes a sound-transparent membrane, an electrolyte, a sound transmission channel, a sensitive electrode, and a sealing shell. The sound-transparent membrane is disposed at both ends of the sound transmission channel, sealing the electrolyte, allowing external underwater acoustic waves to pass through the membrane and act on the electrolyte. The electrolyte serves two purposes: providing a medium for electrochemical reactions and transmitting underwater acoustic signals. The sound transmission channel is filled with electrolyte, and sound waves enter from one end, causing vibrations in liquid particles near the sensitive electrode in the middle of the channel, which then exit from the other end. The sensitive electrode is disposed in the middle of the sound transmission channel, and has several flow holes to allow the electrolyte to pass through. The circuitry includes a current-to-voltage conversion circuit and a differential amplifier circuit. The sealing shell is the outermost layer enclosing the internal structure and circuitry of the hydrophone, exposing only the sound-transparent membrane, and its internal gaps are filled with insulating liquid.

[0008] According to an embodiment of the present invention, the sound-permeable membrane is an inert elastic material with a density close to that of water and which does not react with electrolytes, seawater, etc.

[0009] According to embodiments of the present invention, the electrolyte comprises at least one of the following: an iodine-iodide mixed solution, a bromine-bromine mixed solution, and a ferricyanide-ferrocyanide mixed solution, wherein the electrochemical reaction occurring includes a reversible redox reaction.

[0010] According to an embodiment of the present invention, the sound transmission channel is a structure comprising a pipe with a uniform cross-section or a horn-shaped pipe, wherein the largest end of the horn-shaped pipe is connected to a sound-transmitting diaphragm and the smallest end is connected to a sensitive electrode.

[0011] According to an embodiment of the present invention, the sensitive electrode includes a silicon wafer with a metal foil deposited on its surface. The metal foil is divided into two pairs of cathodes and anodes by insulating spacers, arranged in the order of anode, cathode, cathode, anode, with the voltage between each pair of cathodes and anodes being 0.3 to 0.5V.

[0012] According to an embodiment of the present invention, the insulating liquid comprises silicone oil.

[0013] Beneficial effects:

[0014] (1) The present invention adopts a fixed installation method, which is more convenient than the suspension installation of the co-vibration hydrophone, especially the application of very low frequency band is more reliable, and the size is smaller.

[0015] (2) This invention uses the principle of electrochemical energy conversion to convert external speed signals into voltage signals. It is a speed-type device with the advantages of high low-frequency sensitivity.

[0016] (3) This invention utilizes sound waves to directly penetrate the electrolyte to pick up vibration signals, thereby realizing the direct measurement of vibration velocity signals and opening up a new measurement method. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of the structure of the acoustically transparent electrochemical vector hydrophone of the present invention;

[0018] Figure 2 This is an assembly diagram of the acoustically transparent electrochemical vector hydrophone of the present invention;

[0019] Figure 3 This is a schematic diagram illustrating the detection principle of the acoustically transparent electrochemical vector hydrophone of the present invention.

[0020] Figure reference numerals: sound-permeable membrane-1, sound transmission channel-2, electrolyte-3, sensitive electrode-4, sealing shell-5, liquid injection hole-6, rubber pad-7, silicone oil-8, fixing plate-9, circuit-10, hydrophone core unit-100. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0022] Hydrophones in related technologies suffer from problems such as low sensitivity to low-frequency underwater acoustic signals and cumbersome installation. Sensors made using the electrochemical transduction principle have advantages such as good low-frequency performance, large installation tilt angle, large dynamic range, and low manufacturing cost. Electrochemical vector hydrophones designed based on this principle are sufficient to meet the measurement requirements of hydrophones for low-frequency signals.

[0023] Therefore, as Figure 1As shown, this invention provides a sound-permeable electrochemical vector hydrophone, comprising a sound-permeable membrane 1, an electrolyte 3, a sound transmission channel 2, a sensitive electrode 4, a circuit 10, and a sealing shell 5. The sound-permeable membrane 1 is disposed at both ends of the sound transmission channel 2, used to seal the electrolyte 3 and to allow external sound waves to penetrate and act on the electrolyte 3. The electrolyte 3 is used to generate an electrochemical current and to transmit underwater acoustic signals. The sound transmission channel 2 is filled with electrolyte 3, and sound waves enter from one end of the sound transmission channel 2, acting on the vicinity of the sensitive electrode 4 in the middle of the sound transmission channel 2, causing the liquid near the sensitive electrode 4 to vibrate. The sensitive electrode 4 is disposed in the middle of the sound transmission channel 2, and has several flow holes to allow the electrolyte 3 to pass through, used to output the current, and to output a differential current by connecting to an external differential circuit. The circuit 10 includes a current-to-voltage conversion circuit and a differential amplifier circuit. The sealing shell 5 encloses the internal structure and circuit 10 of the hydrophone, exposing only the sound-permeable membrane 1, and the internal gaps are filled with insulating liquid.

[0024] like Figure 1 As shown, the sound transmission channel 2 is tubular or horn-shaped, with a sensitive electrode 4 sandwiched between two rubber pads 7, connected to one end of the upper and lower sound transmission channels 2. The sound-permeable membrane 1, the sound transmission channel 2, the rubber pads 7, and the sensitive electrode 4 together form a sealed cavity filled with electrolyte 3. Electrolyte is injected into the cavity through the injection hole 6, and then sealed. The sealing shell 5 encloses the cavity except for the sound-permeable membrane 1, and the gap area between the sealing shell and the cavity is filled with silicone oil 8 to balance the internal and external pressure.

[0025] In an embodiment of the present invention, the acoustically transparent electrochemical vector hydrophone forms a sealed cavity through an acoustically transparent membrane 1, a sound transmission channel 2, and a sensitive electrode 4. An electrolyte 3 is disposed within the cavity. The electrolyte 3 undergoes an electrochemical reaction between the sensitive electrodes 4 to generate current. In the absence of external sound waves, the electrolyte 3 near each pair of electrodes undergoes a stable electrochemical reaction, and the output currents are the same, so there is no differential current output. In the presence of external sound waves, the electrolyte 3 near each pair of electrodes moves, causing the electrolyte to move. The electrochemical reaction rate of one pair of electrodes increases, while the electrochemical reaction rate of the other pair of electrodes decreases. The generated current difference is then output as a velocity-related current signal, thus completing the process of converting the underwater acoustic signal into an electrical signal.

[0026] In embodiments of the present invention, the acoustic membrane 1 is a rubber material with a density close to that of seawater and which does not react with the electrolyte, commonly including polyurethane, butyl rubber, etc. Its acoustic impedance is close to that of seawater, so that the sound waves lose almost no energy during penetration, ensuring that the sound waves act on the electrolyte as much as possible; at the same time, as a sealing structure, it should ensure that it does not react with the electrolyte 3. Since the electrolyte 3 used is mostly a solution with strong oxidizing properties, a suitable material can be selected from the rubber materials.

[0027] In embodiments of the present invention, the electrolyte 3 comprises at least one of the following: an iodine-iodide mixed solution, a bromine-bromine mixed solution, and a ferricyanide-ferrocyanide mixed solution, wherein a reversible redox reaction exists in the above solutions. Sound waves can propagate in the solution, thereby causing the liquid to vibrate. An electrochemical method is used to make the reaction rate sensitive to the vibration, thereby forming a correspondingly changing current on the electrode.

[0028] In embodiments of the present invention, the sound transmission channel 2 is a structure comprising a pipe of uniform cross-section or a horn-shaped pipe, wherein the largest end of the horn-shaped pipe is connected to the sound-transmitting diaphragm 1, and the smallest end is connected to the sensitive electrode 4. The sound transmission structure of the horn tube can amplify the particle velocity of the sound wave, thereby improving the sensitivity of the hydrophone.

[0029] In embodiments of the present invention, the sensitive electrode 4 includes, but is not limited to, a silicon wafer with metal foil; other metal electrodes that can stably exist in reversible redox systems such as iodine-iodide mixed solutions, bromine-bromine mixed solutions, and ferricyanide-ferrocyanide mixed solutions are also applicable. The electrode is only used for outputting current and does not participate in electrochemical reactions itself.

[0030] In the embodiments of the present invention, the sensitive electrodes 4 are arranged in the acoustic transmission channel 2 in the order of anode-cathode-cathode-anode. When the electrolyte 3 is stable, the differential output of the cathode current in the two pairs of anodes and cathodes is zero. When the electrolyte 3 is unstable, the symmetrical distribution of ions is broken, and the differential output is related to the vibration of the electrolyte 3. The transduction characteristics of the electrochemical principle give the device based on this principle advantages such as good low-frequency performance, large installation tilt angle, large dynamic range, and low manufacturing cost.

[0031] In an embodiment of the present invention, an iodine-iodide mixed solution is used as the electrolyte for the sensitive electrode 4 in an electrochemical reaction, as an example. The electrolyte in the sensitive device contains I... - and When an external voltage is applied between the anode and cathode, the following reaction occurs:

[0032] Oxidation reaction occurs at the cathode:

[0033]

[0034] A reduction reaction occurs at the anode:

[0035]

[0036] Overall redox reaction:

[0037]

[0038] When the applied voltage remains constant and the external environment is stable, no sound waves are transmitted, and the concentration distribution of ions in the electrolyte 3 at the anode and cathode tends to stabilize. At this time, the output current of each pair of electrodes is the same, and there is no differential output. When external sound waves are transmitted, the sound waves pass through the sound-permeable membrane 1 and act on the electrolyte 3, causing the electrolyte 3 near the electrodes to vibrate. This results in opposite changes in the ion concentration at each pair of anodes and cathodes, i.e., the concentration at one cathode increases. As the concentration increases, the cathode on the other side... As the concentration decreases, the current generated by the redox reaction changes accordingly, and the differential output is a velocity-dependent current. Because this hydrophone is sensitive to velocity changes and is a velocity-type device, its velocity sensitivity is independent of frequency compared to other accelerometer hydrophones, eliminating the need for frequency conversion. Therefore, it also exhibits high sensitivity at low frequencies.

[0039] In embodiments of the present invention, the voltage between the cathode and the anode includes 0.3 to 0.5 V. This voltage is introduced through an external circuit, which on the one hand promotes the convergence of cations and anions near the electrode to form a steady-state distribution, and on the other hand serves as the driving voltage for the electrochemical reaction.

[0040] In embodiments of the present invention, the current-to-voltage conversion circuit is used to convert the weak current signal generated by the sensitive electrode into a measurable voltage signal, and the differential amplifier circuit is used to differentially obtain a complete voltage signal from the two cathode signals, while removing common-mode interference.

[0041] In embodiments of the present invention, the sealing shell serves a protective function, wrapping around the outermost layer. The gaps between the sealing shell and the internal structure and circuitry of the hydrophone are filled with an insulating liquid, including silicone oil, which serves to insulate the electrodes and balance the pressure difference between the inside and outside underwater.

[0042] like Figure 2 As shown, the present invention is symmetrically distributed from top to bottom, consisting of a fixing plate 9, a sound-permeable membrane 1, a sound transmission channel 2, a rubber pad 7, and a sensitive electrode 4. The entire structure is pressed together by screws to form a sealed chamber, and then electrolyte is injected into it through the injection hole 6. After the circuit 10 is soldered, it is fixed to the internal structure of the hydrophone to form the core unit 100 of the hydrophone, which is placed in the protective shell 5, with only the upper and lower sound-permeable membranes 1 exposed.

[0043] like Figure 3 As shown, the acoustically transparent electrochemical vector hydrophone is fixed on the mounting platform and placed underwater. When external sound waves arrive, the sound waves pass through the acoustically transparent membrane 1, through the sound transmission channel 2, and act on the electrolyte 3 near the sensitive electrode 4, causing the electrolyte 3 to vibrate. This causes a change in the ion concentration at the anode and cathode, thereby changing the chemical reaction rate. The current generated by the electrodes also changes accordingly. The difference between the currents of the two pairs of electrodes yields an electrical quantity related to the physical quantity of the vibration velocity of the sound wave particles.

[0044] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A sound-transmitting electrochemical vector hydrophone, characterized in that, It includes an acoustic membrane, electrolyte, sound transmission channel, sensitive electrode, and sealing shell; The sound-permeable membrane is placed at both ends of the sound transmission channel, sealing the electrolyte, and external sound waves can pass through the sound-permeable membrane and act on the electrolyte. The electrolyte serves as a medium for electrochemical reactions and also for transmitting underwater acoustic signals. The sound transmission channel is filled with electrolyte. Sound waves enter from one end of the sound transmission channel, pass through the sensitive electrode in the middle of the sound transmission channel, and cause the particles of the electrolyte near the sensitive electrode to vibrate, and then exit from the other end of the sound transmission channel. The sensitive electrode is located in the middle of the sound transmission channel, and several flow holes are provided on the sensitive electrode to allow the electrolyte to pass through smoothly. The circuit includes a current-to-voltage conversion circuit and a differential amplifier circuit. The acoustically transparent electrochemical vector hydrophone forms a sealed cavity through an acoustically transparent membrane, a sound transmission channel, and sensitive electrodes. An electrolyte is placed inside the cavity. The electrolyte undergoes an electrochemical reaction between the sensitive electrodes to generate current. When there are no external sound waves, the electrolyte near each pair of electrodes undergoes a stable electrochemical reaction, and the output current is the same, so there is no differential current output. When there are external sound waves, the electrolyte near each pair of electrodes moves, causing the electrolyte to move. The electrochemical reaction rate of one pair of electrodes increases, and the electrochemical reaction rate of the other pair of electrodes decreases. The generated current difference is then output as a velocity-related current signal, completing the process of converting the underwater acoustic signal into an electrical signal. The sealing shell is set as the outermost layer, enclosing the internal structure and circuitry of the hydrophone, with only the sound-permeable diaphragm exposed. The internal gaps are filled with an insulating liquid, which includes silicone oil. The sensitive electrodes are arranged in the sound transmission channel in the order of anode-cathode-cathode-anode; The sound-permeable membrane is an inert elastic material with a density close to that of water and does not react with electrolytes or seawater.

2. The acoustically transparent electrochemical vector hydrophone according to claim 1, characterized in that, The electrolyte comprises at least one of the following: Electrochemical reactions occurring in iodine-iodide mixed solutions, bromine-bromine mixed solutions, and ferricyanide-ferrocyanide mixed solutions include reversible redox reactions.

3. The acoustically transparent electrochemical vector hydrophone according to claim 1, characterized in that, The sound transmission channel is a structure comprising a pipe with a uniform cross-section or a horn-shaped pipe, wherein the largest end of the horn-shaped pipe is connected to the sound-transmitting membrane, and the smallest end is connected to the sensitive electrode.

4. The acoustically transparent electrochemical vector hydrophone according to claim 1, characterized in that, The sensitive electrode includes a silicon wafer with a metal foil deposited on its surface. The metal foil is divided into two pairs of cathodes and anodes by insulating spacers, arranged in the order of anode, cathode, cathode, anode, with the voltage between each pair of cathodes and anodes ranging from 0.3 to 0.5V.

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