A feedback electrochemical acoustic pressure hydrophone

Abstract

The present invention discloses a feedback-type electrochemical acoustic pressure hydrophone, belonging to the field of underwater acoustic technology. The device comprises a pressure membrane, an electrolyte, a flow channel, a sensitive electrode, a magnet, a coil, a gas chamber, a circuit, and a sealed housing. The pressure membranes are located on both sides of the hydrophone. The electrolyte moves with the pressure membrane under external pressure, providing an electrochemical reaction medium to the sensitive electrode. The flow channel contains the electrolyte and has the sensitive electrode embedded in its center. The sensitive electrode ensures the flow of the electrolyte within the flow channel. The gas chamber changes volume with external water pressure. The magnet is fixed to the pressure membrane on one side of the gas chamber. The circuit includes a current-voltage conversion circuit, a differential amplifier circuit, and a feedback circuit. The sealed housing encloses the internal structure and circuit of the hydrophone, and the internal gaps are filled with an insulating liquid. The present invention has the advantages of a low frequency band, high sensitivity, and low noise.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater acoustics, and in particular relates to a feedback electrochemical acoustic pressure hydrophone. Background Art

[0002] As a major maritime nation, my country boasts a vast coastline and abundant marine resources. Marine resource development, marine environmental monitoring, and marine military development are crucial means of safeguarding my country's maritime rights and interests. Because electromagnetic waves attenuate rapidly underwater and have limited propagation distance, they are difficult to use for underwater communications. In contrast, sound waves attenuate less underwater and are therefore widely used in underwater technology.

[0003] A hydrophone is a type of sensor that converts underwater acoustic signals into electrical signals. Pressure hydrophones only obtain sound field pressure signals and lack spatial directionality. A single device cannot detect underwater targets. Before the rise of vector hydrophones, multiple pressure hydrophones were generally used to form an array, and the array was used to calculate vector information and the target azimuth. As the detection frequency decreases, the aperture of the hydrophone array becomes larger and larger, making the array more difficult to deploy, and the azimuth resolution of the detection suffers from left-right chord ambiguity. Vector hydrophones can obtain vector parameters in the sound field, such as sound pressure gradient, particle velocity, acceleration, displacement, etc. With the development of underwater acoustic measurement technology, pressure hydrophones are gradually used to be assembled with vector hydrophones into composite hydrophones to obtain complete pressure and sound vector information, thereby using later algorithms to estimate the azimuth and improve detection accuracy.

[0004] Based on their principles, acoustic pressure hydrophones can be categorized as piezoelectric, fiber-optic, and capacitive. In recent years, research in China has primarily focused on improving the sensitivity of acoustic pressure hydrophones. These methods, however, are still based on the aforementioned principles. Compared to mature commercial devices developed abroad, these results still suffer from low sensitivity and high noise levels, making them difficult to meet the requirements for long-range detection of underwater targets. Summary of the Invention

[0005] In order to solve the above technical problems, the main purpose of the present invention is to provide a feedback electrochemical acoustic pressure hydrophone, which includes a pressure membrane, an electrolyte, a flow channel, a sensitive electrode, a magnet, a coil, a gas chamber, a circuit, and a sealed shell; the pressure membrane is located on both sides of the hydrophone, sealing the electrolyte in the flow channel, one side of which senses the pressure change caused by the external water sound, and the other side is connected to the gas chamber to balance the pressure on both sides; the electrolyte moves with the pressure membrane under the action of external pressure, providing an electrochemical reaction medium to the sensitive electrode; the flow channel contains the electrolyte and the sensitive electrode is embedded in the middle; the sensitive electrode includes a plurality of anodes and a plurality of cathodes, and the cathode and anode generate working electricity under the action of an external power supply. The electrode is provided with a number of flow holes to ensure that the electrolyte flows in the flow channel; the gas cavity is connected to the pressure membrane on one side to form a closed space, and the volume changes with the external water pressure; the magnet is fixed on the pressure membrane on one side of the gas cavity, and generates a force opposite to the movement of the pressure membrane under the action of the magnetic field generated by the energized coil; the coil uses the current generated by the sensitive electrode as the feedback current, which is fed back to the coil after circuit processing, so that the coil generates a magnetic field to control the movement of the magnet; the circuit includes a current-voltage conversion circuit, a differential amplifier circuit and a feedback circuit; the sealed shell wraps the internal structure and circuit of the hydrophone, exposing only one side of the pressure membrane, and the internal gap is filled with insulating liquid.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0007] A feedback electrochemical acoustic pressure hydrophone includes a pressure membrane, an electrolyte, a flow channel, a sensitive electrode, a magnet, a coil, a gas chamber, a circuit, and a sealed shell; the pressure membrane is arranged at both ends of the flow channel to seal the electrolyte, one side of which is in contact with the external water to sense the pressure change caused by the water sound, and the other side is in contact with the gas chamber. By compressing the gas chamber, the pressure is increased to balance the pressure membranes on both sides; the electrolyte provides a medium for the electrochemical reaction; the flow channel is filled with electrolyte; the sensitive electrode is arranged in the middle of the flow channel, and there are several flow holes on the electrode to allow the electrolyte to pass through; the magnet serves as a feedback A part is attached to the pressure membrane and generates a force opposite to the flow direction of the electrolyte under the magnetic field generated by the energized coil; the coil, as a part of the feedback, is fixed to the bottom of the gas cavity and generates a magnetic field by the energized current, and the magnitude and direction of the current control the magnitude and direction of the electromagnetic force; the gas cavity is filled with gas, and its volume changes with the magnitude of the external pressure; the circuit includes a current-voltage conversion circuit, a differential amplifier circuit and a feedback circuit; the sealed shell, as the outermost protective shell, wraps the internal structure and circuit of the hydrophone, exposing only one side of the pressure membrane, and the internal gap is filled with insulating liquid.

[0008] According to an embodiment of the present invention, the pressure membrane is made of a rubber material or other equivalent material that does not react with electrolyte, seawater, etc.

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

[0010] According to an embodiment of the present invention, the flow channel is a structure including a pipe with a constant cross section or a trumpet-shaped pipe.

[0011] According to an embodiment of the present invention, the sensitive electrode includes a silicon wafer with a metal foil deposited on the surface, and the metal foil is divided into two pairs of cathodes and anodes by an insulating spacer, which are arranged in sequence of anode, cathode, cathode, anode (or cathode, anode, anode, cathode), and the voltage between each pair of cathodes and anodes is 0.3~0.5V.

[0012] According to an embodiment of the present invention, the gas cavity is connected to the pressure membrane on one side to form a closed space, and the internal pressure-volume product remains unchanged.

[0013] According to an embodiment of the present invention, the magnet is a magnet with strong magnetic force including permanent magnetic materials such as neodymium iron boron magnet and ferrite, fixed at the center of the pressure membrane on one side, and sleeved in the coil.

[0014] According to an embodiment of the present invention, the coil is fixed to the bottom of the gas chamber, and the feedback current passes through the coil to generate a magnetic field, causing the magnet to generate a feedback force acting on the pressure membrane.

[0015] According to an embodiment of the present invention, the insulating liquid includes silicone oil.

[0016] Beneficial effects:

[0017] (1) This invention is the first to use electrochemical principles to produce an acoustic pressure hydrophone, opening up a new measurement method.

[0018] (2) The present invention adopts the principle of electrochemical transduction to convert external sound pressure changes into electrolyte vibrations, and then uses the characteristics of electrochemistry to convert the electrolyte vibrations into voltage signals, which has the advantages of low frequency band, high sensitivity and low noise.

[0019] (3) The present invention adopts the method of electromagnetic force negative feedback to compensate the sound pressure scalar, broadens the frequency band range, and improves the performance of the electrochemical acoustic pressure hydrophone. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a structural cross-sectional view of the feedback electrochemical acoustic pressure hydrophone of the present invention;

[0021] Figure 2 is an assembly diagram of the feedback electrochemical acoustic pressure hydrophone of the present invention;

[0022] Figure 3It is a schematic diagram of the detection principle of the feedback electrochemical acoustic pressure hydrophone of the present invention.

[0023] Reference numerals: pressure membrane-1, flow channel-2, electrolyte-3, sensitive electrode-4, gas chamber-5, magnet-6, coil-7, sealing shell-8, rubber pad-9, silicone oil-10, injection hole-11, fixing plate-12, circuit-13, Ion-14, cathode-15, anode-16. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0025] Conventional hydrophones suffer from poor low-frequency performance, low sensitivity, and high noise. Vibration sensors fabricated using the electrochemical transduction principle offer advantages such as good low-frequency performance, high sensitivity, and low noise. Designing an electrochemical acoustic pressure hydrophone based on this principle can address these issues. Furthermore, the negative feedback design helps broaden the frequency band, further enhancing hydrophone performance.

[0026] like Figure 1 As shown, a feedback electrochemical acoustic pressure hydrophone of the present invention includes a pressure membrane 1, an electrolyte 3, a flow channel 2, a sensitive electrode 4, a magnet 6, a coil 7, a gas chamber 5, a circuit 13, and a sealed shell 8; the pressure membrane 1 is arranged at both ends of the flow channel 2 to seal the electrolyte 3, one side of which is in contact with the external water to sense the pressure change caused by the water sound, and the other side is in contact with the gas chamber 5. By compressing the gas chamber 5, the pressure is increased to balance the pressure membranes 1 on both sides; the electrolyte 3 provides a medium for the electrochemical reaction; the interior of the flow channel 2 is filled with the electrolyte 3; the sensitive electrode 4 is arranged in the middle of the flow channel 2, and has a plurality of flow holes on the sensitive electrode 4 to allow the electrolyte 3 to pass through; The magnet 6 is attached to the pressure membrane 1 as part of the feedback, and generates a force opposite to the flow direction of the electrolyte 3 under the magnetic field generated by the energized coil 7; the coil 7 is fixed to the bottom of the gas chamber 5 as part of the feedback, and generates a magnetic field by using the current, and the magnitude and direction of the current control the magnitude and direction of the electromagnetic force; the gas chamber 5 is filled with gas, and its volume changes with the external pressure; the circuit 13 includes a current-voltage conversion circuit, a differential amplifier circuit and a feedback circuit; the sealed shell 8 is the outermost protective shell, which encloses the internal structure and circuit 13 of the acoustic pressure hydrophone, exposing only one side of the pressure membrane 1, and the internal gap is filled with insulating liquid.

[0027] like Figure 1As shown, the flow channel 2 is tubular or trumpet-shaped, and the sensitive electrode 4 is sandwiched between two rubber pads 9, which are connected to one end of the upper and lower flow channels 2. The pressure membrane 1, the flow channel 2, the rubber pad 9 and the sensitive electrode 4 are pressed together by the fixing plate 12 to form a sealed cavity, which is filled with electrolyte 3. The gas cavity 5 is connected to the lower side of the pressure membrane 1, the magnet 6 is fixed on the pressure membrane 1 on this side, and the coil 7 is fixed to the bottom of the gas cavity 5, and the two constitute a feedback system. The injection hole 11 injects the electrolyte 3 into the sealed cavity, and then seals it. The circuit 13 is fixed to the structure. The sealing shell 8 wraps the internal structure and circuit 13 of the acoustic pressure hydrophone, exposing only the upper pressure membrane 1. The remaining gap is filled with silicone oil 10 to balance the internal and external pressures.

[0028] In an embodiment of the present invention, the feedback electrochemical acoustic pressure hydrophone comprises a pressure membrane 1, a flow channel 2, and a sensitive electrode 4, forming a sealed chamber. An electrolyte 3 is disposed within the chamber, and the lower end is connected to an air chamber 5 and a feedback system to balance the external pressure. The feedback system comprises the lower pressure membrane 1, a magnet 6, and a coil 7. When there are no external sound waves, the pressures on both sides of the electrolyte 3 are uniform and the electrolyte 3 does not move, resulting in the acoustic pressure hydrophone outputting background noise. When a sound pressure signal acts on the upper pressure membrane 1, the pressures on both sides of the electrolyte 3 become inconsistent. The air chamber 5 compresses, causing the pressures on both sides of the pressure membrane 1 to approach equilibrium. During this equilibrium process, the electrolyte 3 moves, the ion concentration near the electrodes changes, and the electrochemical reaction rate on the sensitive electrode 4 changes. The currents output by the two cathodes are differentiated as the final output current. A portion of this current is input into the coil 7 as a feedback signal through the feedback circuit of circuit 13, generating a magnetic field that drives the magnet 6 in opposite directions, thus achieving mechanical feedback. The above process converts the hydroacoustic signal into an electrical signal.

[0029] In the embodiment of the present invention, the pressure membrane 1 is made of butyl rubber or the like that does not react with the electrolyte 3 , seawater, or the like.

[0030] In an embodiment of the present invention, the electrolyte 3 includes at least one of the following: an iodine-iodide mixed solution, a bromine-bromide mixed solution, and a ferrocyanide-ferrocyanide mixed solution, wherein a reversible redox reaction occurs in the above solutions.

[0031] In the embodiment of the present invention, the flow channel 2 is a structure comprising a pipe of uniform cross-section or a trumpet-shaped pipe, wherein the largest end of the trumpet-shaped pipe is connected to the pressure membrane 1, and the smallest end is connected to the sensitive electrode 4. The trumpet-shaped pipe flow channel structure can increase the vibration velocity of the electrolyte near the electrode, thereby improving the sensitivity of the hydrophone.

[0032] In the embodiments of the present invention, 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-bromide mixed solutions, and ferrocyanide-ferrocyanide mixed solutions are also suitable. The electrodes are used only to output current and do not participate in the electrochemical reaction.

[0033] In an embodiment of the present invention, the sensitive electrodes 4 are arranged in the flow channel 2 in the order of anode 16-cathode 15-cathode 15-anode 16 (or cathode 15, anode 16, anode 16, cathode 15). When the electrolyte is stable, the differential output of the two pairs of electrode currents is zero. When the electrolyte is unstable, the symmetrical distribution state of the ions is broken, and the differential output is related to the vibration of the electrolyte.

[0034] In the embodiment of the present invention, an iodine-iodide mixed solution is used as an electrolyte for electrochemical reaction of the sensitive electrode 4 as an example. The electrolyte in the sensitive device contains I - and Ion 14, after applying voltage between cathode 15 and anode 16, the redox reaction that occurs is as follows:

[0035]

[0036]

[0037] Under the condition of constant external voltage, when the external environment is stable, the concentration distribution of ions in the cathode and anode of the electrolyte 3 tends to be stable, and the output current of each pair of electrodes is the same, and there is no output of the difference. When there is sound pressure outside, a pressure difference is formed on both sides of the electrolyte 3, and the gas cavity 5 is compressed, causing the electrolyte 3 to move to one side, resulting in opposite changes in the ion concentration at each pair of cathode 15 and anode 16, that is, the cathode 15 on one side has a positive current. The concentration of ions 14 increases, and the cathode 15 on the other side The concentration of ions 14 decreases, and the current generated by the redox reaction changes accordingly. After differentiation, the output is a current related to the sound pressure.

[0038] In the embodiment of the present invention, the voltage between the cathode 15 and the anode 16 is 0.3-0.5 V. This voltage is introduced through an external circuit, which not only promotes the anions and cations to approach the electrodes to form a steady-state distribution, but also serves as a driving voltage for the electrochemical reaction.

[0039] In an embodiment of the present invention, the gas cavity 5 is connected to the pressure membrane 1 on one side to form a closed space, the internal pressure-volume product remains unchanged, the volume of the gas cavity 5 changes with the external sound pressure, and the electrolyte 3 also moves accordingly, thereby converting the external sound pressure signal into a vibration signal of the electrolyte.

[0040] In an embodiment of the present invention, the magnet 6 is a magnet with relatively strong magnetic force, including a neodymium iron boron magnet, which is fixed at the center of the pressure membrane 1 on one side of the gas chamber 5 and placed in the coil 7 to generate feedback force with the magnetic field in the coil 7.

[0041] In an embodiment of the present invention, the coil 7 is fixed at the bottom of the gas chamber 5 , and the differential current generated by the sensitive electrode 4 is used as the feedback current. The input coil 7 generates a magnetic field, causing the magnet 6 to generate a feedback force acting on the pressure membrane 1 .

[0042] In an embodiment of the present invention, the current-voltage conversion circuit in the circuit 13 is used to convert the weak current signal generated by the sensitive electrode 4 into a measurable voltage signal, the differential amplifier circuit is used to differential the signals of the two cathodes 15 to obtain a complete voltage signal while removing common-mode interference, and the feedback circuit is used to adjust the magnitude of the feedback force of the magnet 6.

[0043] In the embodiment of the present invention, the sealing shell 8 plays a sealing role and is wrapped in the outermost layer. The gap between the internal structure of the hydrophone and the circuit 13 is filled with an insulating liquid. The insulating liquid includes silicone oil, which plays the role of insulating the sensitive electrode and balancing the pressure difference between the inside and outside of the water.

[0044] like Figure 2 As shown, first, the magnet 6 is fixed to the lower pressure membrane 1, and the coil 7 is fixed to the bottom of the gas chamber 5. Then, screws are used to tighten the fixing plate 12, pressure membrane 1, flow channel 2, rubber pad 9, sensitive electrode 4, and gas chamber 5 to form a sealed electrolyte chamber. The electrolyte 3 is then injected into the chamber through the injection hole 11. The welded circuit 13 is then fixed to the structure, and the internal electrochemical structure and circuit 13 are enclosed in a sealed shell 8, leaving only the upper pressure membrane 1 exposed for sensing sound pressure. Finally, the gap within the sealed shell 8 is filled with silicone oil 10 to achieve insulation and internal and external pressure balance.

[0045] like Figure 3 As shown, when the feedback electrochemical acoustic pressure hydrophone is working underwater, when there is no external sound pressure, the electrolyte 3 does not move, and there is no current after the difference. When there is external sound pressure, a pressure difference is formed on both sides of the electrolyte 3, and the gas cavity 5 is compressed, causing the electrolyte 3 to move to one side, resulting in the cathode 15 on one side being The concentration of ions 14 increases, and the cathode 15 on the other side The concentration of ions 14 decreases, and the currents generated by the two pairs of electrodes change in opposite directions. After differentiation, the output current is related to the sound pressure. This current also serves as a feedback current. After being processed by the feedback circuit, it is input to the coil 7 to generate a magnetic field. The magnet 6 generates a force in the magnetic field in the opposite direction to the movement of the electrolyte 3 to balance the movement, thereby achieving the purpose of force balance feedback.

[0046] It will be easily understood by those skilled in the art that the above description is only 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 in the scope of protection of the present invention.

Claims

1. A feedback electrochemical acoustic pressure hydrophone, characterized in that: It includes pressure membrane, electrolyte, flow channel, sensitive electrode, magnet, coil, gas chamber, circuit and sealing shell; The pressure membranes are placed at both ends of the flow channel to seal the electrolyte in the flow channel. One side is in direct contact with the external water to sense pressure changes, and the other side is connected to the gas cavity. The pressure on the pressure membranes on both sides is balanced by compressing the gas cavity. The electrolyte provides a medium for the electrochemical reaction of the sensitive electrode; The interior of the flow channel is filled with electrolyte; The sensitive electrode is placed in the middle of the flow channel. There are several flow holes on the sensitive electrode, and the electrolyte in the flow channel can pass through smoothly. When voltage is applied to the anode, current is generated at the cathode. The magnet, as a part of the feedback, is fixed on the pressure membrane and generates a magnetic force under the magnetic field to move the pressure membrane; The coil is fixed to the bottom of the gas chamber as part of the feedback. When electricity is applied to the coil, a magnetic field is generated. The magnitude and direction of the current controls the magnitude and direction of the magnetic force of the magnet. The gas cavity is fixed on one side of the pressure membrane and is filled with gas, and its volume changes with the external water pressure; The circuit includes a current-voltage conversion circuit, a differential amplifier circuit and a feedback circuit; The sealing shell is the outermost protective shell, which encloses the internal structure and circuit of the hydrophone, with only one side of the pressure membrane exposed, and the internal gap is filled with insulating liquid.

2. The feedback electrochemical acoustic pressure hydrophone according to claim 1, characterized in that: The pressure membrane is made of a rubber material that does not react with the electrolyte and is not corroded by seawater.

3. The feedback electrochemical acoustic pressure hydrophone according to claim 1, characterized in that: The electrolyte comprises at least one of the following: The electrochemical reactions occurring in the iodine-iodide mixed solution, the bromine-bromide mixed solution, and the ferrocyanide-ferrocyanide mixed solution include reversible redox reactions.

4. The feedback electrochemical acoustic pressure hydrophone according to claim 1, characterized in that: The flow channel is a structure including a pipe with a constant cross section or a trumpet-shaped pipe.

5. The feedback electrochemical acoustic pressure hydrophone according to claim 1, characterized in that: The sensitive electrode includes a silicon wafer with metal foil deposited on the surface. The metal foil is divided into two pairs of cathodes and anodes by an insulating spacer, and is arranged in sequence of anode, cathode, cathode, anode or cathode, anode, anode, cathode. The voltage between each pair of cathodes and anodes is 0.3 to 0.5V.

6. The feedback electrochemical acoustic pressure hydrophone according to claim 1, characterized in that: The gas cavity is connected to the pressure membrane on one side to form a closed space, and the internal pressure-volume product remains unchanged.

7. The feedback electrochemical acoustic pressure hydrophone according to claim 1, characterized in that: The magnet comprises neodymium iron boron and ferrite, is fixed at the center of the pressure film on one side, and is placed in the coil.

8. The feedback electrochemical acoustic pressure hydrophone according to claim 1, characterized in that: The coil is fixed at the bottom of the gas chamber, and the feedback current passes through the coil to generate a magnetic field, which causes the magnet to generate a feedback force acting on the pressure membrane.

9. The feedback electrochemical acoustic pressure hydrophone according to claim 1, characterized in that: The insulating liquid is silicone oil.

Images