Sensitization type MEMS hydrophone and preparation method thereof

Abstract

The invention discloses a sensitization type MEMS hydrophone and a preparation method thereof. The sensitization type MEMS hydrophone comprises a sensitization type elastic substrate, a lower electrode assembly, a PZT piezoelectric sensitive assembly, an upper electrode assembly and an insulating material layer. The lower electrode assembly, the PZT piezoelectric sensitive assembly and the upper electrode assembly are sequentially arranged on the surface of the sensitization type elastic substrate from bottom to top, and the insulating material layers are arranged on the surface of the sensitization type elastic substrate, in the lower electrode assembly, in the PZT piezoelectric sensitive assembly and in the upper electrode assembly respectively. Therefore, the interior of the lower electrode assembly, the interior of the PZT piezoelectric sensitive assembly and the interior of the upper electrode assembly are insulated. The lower electrode assembly and the upper electrode assembly are led out through conductive cables and connected in series, electric signals generated by the PZT piezoelectric sensitive assembly are output through the lower electrode assembly and the upper electrode assembly, and signal measurement is achieved through a circuit and a test system. The MEMS hydrophone has the advantages of being compact in structure, high in sensitivity, high in anti-interference capacity and the like, and the application range of the MEMS hydrophone is widened.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrophones, and particularly relates to a sensitivity-enhanced MEMS hydrophone and a preparation method thereof. Background Art

[0002] MEMS hydrophones are widely used in underwater detection, identification, communication, target positioning, ranging, tracking, etc. Traditional MEMS hydrophones generally include capacitive MEMS hydrophones, piezoresistive MEMS hydrophones, and piezoelectric MEMS hydrophones with a flat membrane structure.

[0003] Capacitive MEMS hydrophones are usually designed and manufactured using the working principle of a parallel-plate capacitor. The capacitance between the plates is affected by the dielectric constant of the medium between the plates, the area of the plates, and the distance between the two plates. Therefore, the accuracy is relatively low. The disadvantage of capacitive MEMS hydrophones is that they are easily affected by parasitic capacitance during operation, which easily leads to a decrease in the working accuracy of the hydrophone.

[0004] Most piezoresistive MEMS hydrophones are made using the piezoresistive effect of semiconductors. The piezoresistive effect of semiconductors is due to the deformation of the semiconductor energy band under stress. The deformed energy band changes the effective mass of the density of states and the mobility of carriers. The piezoresistive characteristics of semiconductors are one order of magnitude higher than those of metals, which changes the resistance value. Therefore, by further using the change in the resistance value and the relationship between the changed resistance value and pressure, the change in the measured pressure can be indirectly obtained. The disadvantage of piezoresistive MEMS hydrophones is that they are very sensitive to temperature changes, which also results in poor stability, poor anti-interference ability, and susceptibility to temperature changes in actual use.

[0005] Traditional piezoelectric MEMS hydrophones usually use a flat membrane structure as a sensitivity-enhanced elastic substrate, and there are problems such as poor sensitivity, low-frequency response characteristics, and narrow working bandwidth, which cannot meet the requirements of improving the low-frequency response characteristics of hydrophones and broadening the working bandwidth of hydrophones. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a sensitivity-enhanced MEMS hydrophone and a preparation method thereof that are compact in structure, high in sensitivity, high in stability, and strong in anti-interference ability to solve the problem that existing MEMS hydrophones cannot simultaneously meet the requirements of high sensitivity, good low-frequency response characteristics, wide frequency bandwidth, etc.

[0007] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0008] A sensitivity-enhanced MEMS hydrophone, comprising: a sensitivity-enhanced elastic substrate, a lower electrode assembly, a PZT piezoelectric sensitive assembly, an upper electrode assembly, and an insulating material layer; the lower electrode assembly is disposed on the surface of the sensitivity-enhanced elastic substrate, the PZT piezoelectric sensitive assembly is disposed on the surface of the lower electrode assembly, the upper electrode assembly is disposed on the surface of the PZT piezoelectric sensitive assembly, and the insulating material layer is respectively disposed on the surface of the sensitivity-enhanced elastic substrate, inside the lower electrode assembly, inside the PZT piezoelectric sensitive assembly, and inside the upper electrode assembly to achieve insulation inside the lower electrode assembly, inside the PZT piezoelectric sensitive assembly, and inside the upper electrode assembly; both the lower electrode assembly and the upper electrode assembly are led out through conductive cables and are connected in series, and the electrical signal generated by the PZT piezoelectric sensitive assembly is output through the lower electrode assembly and the upper electrode assembly, and signal measurement is achieved through a circuit and a test system.

[0009] As a further improvement of the present invention, the lower electrode assembly includes an annular lower electrode and a circular lower electrode, the circular lower electrode is disposed inside the annular lower electrode, and an insulating material layer is provided between the annular lower electrode and the circular lower electrode; both the annular lower electrode and the circular lower electrode are led out through conductive cables.

[0010] As a further improvement of the present invention, the upper electrode assembly includes an annular upper electrode and a circular upper electrode, the circular upper electrode is disposed inside the annular upper electrode, and an insulating material layer is provided between the annular upper electrode and the circular upper electrode; both the annular upper electrode and the circular upper electrode are led out through conductive cables.

[0011] As a further improvement of the present invention, the PZT piezoelectric sensitive assembly includes an annular piezoelectric material layer and a circular piezoelectric material layer, the annular piezoelectric material layer is located between the annular lower electrode and the annular upper electrode, and the circular piezoelectric material layer is located between the circular lower electrode and the circular upper electrode.

[0012] As a further improvement of the present invention, after the sensitivity-enhanced elastic substrate is subjected to a uniform pressure p, the stress relationship is as follows:

[0013]

[0014] In the formula: p represents the uniform pressure applied to the sensitivity-enhanced elastic substrate, μ represents the Poisson's ratio of the sensitivity-enhanced elastic substrate, h represents the thickness of the sensitivity-enhanced elastic substrate, E represents the elastic modulus of the sensitivity-enhanced elastic substrate, R represents the radius of the sensitivity-enhanced structure, and r represents the distance between the stress application point and the center of the sensitivity-enhanced structure.

[0015] As a further improvement of the present invention, the annular piezoelectric material layer operates in the d 31 mode; after the PZT piezoelectric sensitive assembly is subjected to stress, the relationship between the equivalent electric potential generated on the surface of the annular piezoelectric material layer and the stress is as follows:

[0016]

[0017] In the formula: F represents the pressure applied to the piezoelectric material, w represents the length of the piezoelectric material, ε represents the dielectric constant of the piezoelectric material, ε0 represents the vacuum permittivity, and d 31 Piezoelectric constant.

[0018] As a further improvement of the present invention, the circular piezoelectric material layer operates in the d 33 mode; after the PZT piezoelectric sensitive component is stressed, the relationship between the equivalent electric potential generated on the surface of the circular piezoelectric material layer and the stress is as follows:

[0019]

[0020] In the formula: F represents the pressure applied to the piezoelectric material, w represents the length of the piezoelectric material, l represents the thickness of the piezoelectric material, ε represents the dielectric constant of the piezoelectric material, ε0 represents the vacuum permittivity, and d 33 Piezoelectric constant.

[0021] As a further improvement of the present invention, the PZT piezoelectric sensitive component is prepared by using PZT material or a hybrid material of ZnO material and PZT material.

[0022] As a general technical concept, the present invention also provides a preparation method applicable to the above-mentioned sensitivity-enhanced MEMS hydrophone, including the following steps:

[0023] Step S1: Use the screen printing process to print the annular lower electrode and the circular lower electrode on the surface of the sensitivity-enhanced elastic substrate;

[0024] Step S2: Use the screen printing process to print the annular piezoelectric material layer and the circular piezoelectric material layer on the surfaces of the annular lower electrode and the circular lower electrode respectively;

[0025] Step S3: Use the screen printing process to print the insulating material layer on the surface of the sensitivity-enhanced elastic substrate, and the insulating material layer fills the gaps between the annular lower electrode and the circular lower electrode and the gaps between the annular piezoelectric material layer and the circular piezoelectric material layer;

[0026] Step S4: Use the screen printing process to print the annular upper electrode and the circular upper electrode on the surfaces of the annular piezoelectric material layer and the circular piezoelectric material layer;

[0027] Step S5: Use conductive cables to lead out the annular lower electrode and the circular lower electrode, and the annular upper electrode and the circular upper electrode respectively;

[0028] Step S6: Use an adhesive to paste and fix the sensitivity-enhanced elastic substrate with the annular lower electrode, annular piezoelectric material layer, annular upper electrode, circular lower electrode, circular piezoelectric material layer, circular upper electrode, and insulating material layer on the splint, realizing the peripheral fixed support of the sensitivity-enhanced elastic substrate.

[0029] As a further improvement of the present invention, in the step S1, the annular lower electrode and the circular lower electrode are fixed on the sensitivity-enhanced elastic substrate by sintering and forming;

[0030] In the step S2, the annular piezoelectric material layer is fixed on the annular lower electrode by sintering and forming, and the circular piezoelectric material layer is fixed on the circular lower electrode by sintering and forming;

[0031] In the step S3, the annular upper electrode is fixed on the annular piezoelectric material layer by sintering and forming, and the circular upper electrode is fixed on the circular piezoelectric material layer by sintering and forming;

[0032] In the step S4, the insulating material layer is fixed on the sensitivity-enhanced elastic substrate by sintering and forming.

[0033] Compared with the prior art, the advantages of the present invention are as follows:

[0034] 1. The sensitivity-enhanced MEMS hydrophone and its preparation method of the present invention form a piezoelectric hydrophone with a corrugated structure by arranging the lower electrode assembly on the surface of the sensitivity-enhanced elastic substrate, arranging the PZT piezoelectric sensitive assembly on the surface of the lower electrode assembly, and then arranging the upper electrode assembly on the surface of the PZT piezoelectric sensitive assembly. The lower electrode assembly and the upper electrode assembly are both led out through conductive cables. And an insulating material layer is provided to realize insulation inside the lower electrode assembly, inside the PZT piezoelectric sensitive assembly, and inside the upper electrode assembly, ensuring the reliability of piezoelectric signal detection and conduction. The present invention utilizes the high-sensitivity characteristics of the corrugated structure and the good low-frequency response characteristics of the flat film structure, obtaining a sensitivity-enhanced MEMS hydrophone with simple structure process, convenient production, and excellent performance. Moreover, through the design of the sensitivity-enhanced structure and the selection of piezoelectric materials, the functions of high sensitivity, wide bandwidth, and good low-frequency characteristics of the MEMS hydrophone are realized, providing a new idea for the design of MEMS hydrophones.

[0035] 2. The sensitivity-enhanced MEMS hydrophone and its preparation method of the present invention utilize the characteristics of high stability and good piezoelectric performance of the PZT material, combining the d31 and d33 working modes of the piezoelectric material, which can better improve the sensitivity of the MEMS hydrophone. And the hydrophone does not require an external power supply during operation, which can avoid the influence of temperature on the hydrophone, further improving the anti-interference ability and stability of the hydrophone, and solving the problems of poor stability, poor anti-interference ability, and susceptibility to temperature influence of traditional MEMS hydrophones. Description of the Drawings

[0036] Figure 1 This is a schematic diagram of the three-dimensional structure principle of the sensitivity-enhanced MEMS hydrophone in a specific embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of the two-dimensional structure principle of the sensitivity-enhanced MEMS hydrophone in a specific embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the two-dimensional structure principle of the sensitivity-enhanced MEMS hydrophone from another perspective in a specific embodiment of the present invention;

[0039] Legend: 1. Sensitivity-enhanced elastic substrate; 2. Annular lower electrode; 3. Annular piezoelectric material layer; 4. Annular upper electrode; 5. Circular lower electrode; 6. Circular piezoelectric material layer; 7. Circular upper electrode; 8. Insulating material layer. Detailed implementation manners

[0040] The present invention will be further described below in conjunction with the accompanying drawings of the specification and specific preferred embodiments, but this does not limit the protection scope of the present invention.

[0041] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "side part", "center", "longitudinal direction", "transverse direction", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial direction", "radial direction", "circumferential direction", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present invention.

[0042] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0043] Embodiment 1

[0044] As Figure 1 、 Figure 2 and Figure 3As shown in the figure, the sensitivity-enhanced MEMS hydrophone of the present invention includes: a sensitivity-enhanced elastic substrate 1, a lower electrode assembly, a PZT piezoelectric sensitive assembly, an upper electrode assembly, and an insulating material layer 8. The lower electrode assembly is disposed on the surface of the sensitivity-enhanced elastic substrate 1, the PZT piezoelectric sensitive assembly is disposed on the surface of the lower electrode assembly, the upper electrode assembly is disposed on the surface of the PZT piezoelectric sensitive assembly, and the insulating material layer 8 is respectively disposed on the surface of the sensitivity-enhanced elastic substrate 1 and extends into the interior of the lower electrode assembly, the PZT piezoelectric sensitive assembly, and the upper electrode assembly to insulate the interiors of the lower electrode assembly, the PZT piezoelectric sensitive assembly, and the upper electrode assembly. Both the lower electrode assembly and the upper electrode assembly are led out through conductive cables and are connected in series. The electrical signal generated by the PZT piezoelectric sensitive assembly is output through the lower electrode assembly and the upper electrode assembly, and signal measurement is achieved through a circuit and a test system. The sensitivity-enhanced structure of this embodiment can increase the first-order characteristic frequency of the MEMS hydrophone itself and broaden the working bandwidth of the hydrophone.

[0045] In this embodiment, the PZT piezoelectric sensitive assembly is prepared from PZT (lead zirconate titanate) material. In other embodiments, it is prepared from a mixed material of ZnO material and PZT material. By reasonably controlling the thickness and position distribution of the ZnO material and the PZT material, the piezoelectric performance of the piezoelectric material itself can be fully exerted.

[0046] As Figure 1 shown, the lower electrode assembly includes an annular lower electrode 2 and a circular lower electrode 5. The circular lower electrode 5 is disposed inside the annular lower electrode 2, and an insulating material layer 8 is provided between the annular lower electrode 2 and the circular lower electrode 5. Both the annular lower electrode 2 and the circular lower electrode 5 are led out through platinum wires.

[0047] As Figure 1 shown, the upper electrode assembly includes an annular upper electrode 4 and a circular upper electrode 7. The circular upper electrode 7 is disposed inside the annular upper electrode 4, and an insulating material layer 8 is provided between the annular upper electrode 4 and the circular upper electrode 7. Both the annular upper electrode 4 and the circular upper electrode 7 are led out through platinum wires.

[0048] As Figure 1 shown, the PZT piezoelectric sensitive assembly includes an annular piezoelectric material layer 3 and a circular piezoelectric material layer 6. The annular piezoelectric material layer 3 is located between the annular lower electrode 2 and the annular upper electrode 4, and the circular piezoelectric material layer 6 is located between the circular lower electrode 5 and the circular upper electrode 7.

[0049] In this embodiment, the PZT material is printed on the surface of the sensitivity-enhanced elastic substrate 1 through a screen printing process, and a piezoelectric sensitive material film is formed through high-temperature sintering. After the sensitivity-enhanced elastic substrate 1 is subjected to acoustic pressure, deformation occurs. When the piezoelectric material is stressed, according to the piezoelectric effect, the pressure received will be converted into a charge signal output, completing the quasi-conversion of the force-electricity relationship, and further completing the measurement of pressure. After the sensitivity-enhanced elastic substrate 1 is subjected to a uniform pressure p, the stress relationship is as follows:

[0050]

[0051] In the formula: p represents the uniform pressure received by the sensitivity-enhanced elastic substrate 1, μ represents the Poisson's ratio of the sensitivity-enhanced elastic substrate 1, h represents the thickness of the sensitivity-enhanced elastic substrate 1, E represents the elastic modulus of the sensitivity-enhanced elastic substrate 1, R represents the radius of the sensitivity-enhanced structure, and r represents the distance between the stress point and the center of the sensitivity-enhanced structure.

[0052] In this embodiment, the annular piezoelectric material layer 3 operates in the d 31 mode. After the PZT piezoelectric sensitive component is stressed, the relationship between the equivalent electric potential generated on the surface of the annular piezoelectric material layer 3 and the stress is as follows:

[0053]

[0054] In the formula: F represents the pressure received by the piezoelectric material, w represents the length of the piezoelectric material, ε represents the dielectric constant of the piezoelectric material, ε0 represents the vacuum dielectric constant, d 31 piezoelectric constant.

[0055] In this embodiment, the circular piezoelectric material layer 6 operates in the d 33 mode. After the PZT piezoelectric sensitive component is stressed, the relationship between the equivalent electric potential generated on the surface of the circular piezoelectric material layer 6 and the stress is as follows:

[0056]

[0057] In the formula: F represents the pressure received by the piezoelectric material, w represents the length of the piezoelectric material, l represents the thickness of the piezoelectric material, ε represents the dielectric constant of the piezoelectric material, ε0 represents the vacuum dielectric constant, d 33 piezoelectric constant.

[0058] In this embodiment, by combining the sensitivity-enhanced structure with the PZT material with good piezoelectric performance and utilizing the d31 and d33 working modes of the piezoelectric material, the sensitivity of the MEMS hydrophone can be better improved. Moreover, when the hydrophone works, it does not require an external power supply, which can avoid the influence of temperature on the hydrophone and further improve the anti-interference ability and stability of the hydrophone.

[0059] Embodiment 2

[0060] In this embodiment, a preparation method applicable to the sensitized MEMS hydrophone in Embodiment 1 is further provided, including the following steps:

[0061] Step S1: Use the screen printing process to print the annular lower electrode 2 and the circular lower electrode 5 on the surface of the sensitized elastic substrate 1. And through sintering, the annular lower electrode 2 and the circular lower electrode 5 are formed and fixed on the sensitized elastic substrate 1.

[0062] Step S2: Use the screen printing process to print the annular piezoelectric material layer 3 and the circular piezoelectric material layer 6 on the surfaces of the annular lower electrode 2 and the circular lower electrode 5 respectively. And through sintering, the annular piezoelectric material layer 3 is formed and fixed on the annular lower electrode 2, and the circular piezoelectric material layer 6 is formed and fixed on the circular lower electrode 5.

[0063] Step S3: Use the screen printing process to print the insulating material layer 8 on the surface of the sensitized elastic substrate 1, and through sintering, the insulating material layer 8 is formed and fixed on the sensitized elastic substrate 1, so that the insulating material layer 8 fills the gaps between the annular lower electrode 2 and the circular lower electrode 5 and between the annular piezoelectric material layer 3 and the circular piezoelectric material layer 6.

[0064] Step S4: Use the screen printing process to print the annular upper electrode 4 and the circular upper electrode 7 on the surfaces of the annular piezoelectric material layer 3 and the circular piezoelectric material layer 6 respectively. And through sintering, the annular upper electrode 4 is formed and fixed on the annular piezoelectric material layer 3, and the circular upper electrode 7 is formed and fixed on the circular piezoelectric material layer 6.

[0065] The insulating material layer 8 is mainly used to isolate between the annular lower electrode 2 and the circular lower electrode 5, between the annular piezoelectric material layer 3 and the circular piezoelectric material layer 6, and between the annular upper electrode 4 and the circular upper electrode 7.

[0066] Step S5: Use platinum wires to lead out the annular lower electrode 2 and the circular lower electrode 5, and the annular upper electrode 4 and the circular upper electrode 7 respectively.

[0067] Step S6: Use a two-component epoxy adhesive to paste and fix the sensitized elastic substrate 1 with the annular lower electrode 2, the annular piezoelectric material layer 3, the annular upper electrode 4, the circular lower electrode 5, the circular piezoelectric material layer 6, the circular upper electrode 7 and the insulating material layer 8 on the splint, so as to realize the peripheral fixation of the sensitized elastic substrate 1.

[0068] During the processing and manufacturing of the MEMS hydrophone, it is necessary to ensure the center alignment of the annular lower electrode 2, the annular piezoelectric material layer 3, the annular upper electrode 4, the circular lower electrode 5, the circular piezoelectric material layer 6, the circular upper electrode 7, the insulating material layer 8 and the splint, so as to prevent the problem of uneven stress when the sensitized elastic substrate 1 is stressed.

[0069] During use, the encapsulated MEMS hydrophone is fixed on a specific test fixture to prevent the MEMS hydrophone from loosening and being damaged during the test. When testing in an anechoic tank, the MEMS hydrophone detects an underwater acoustic signal. The sensitized elastic substrate 1 will deform due to the sound pressure. The annular piezoelectric material layer 3 printed and fixed on the annular lower electrode 2 and the circular piezoelectric material layer 6 printed on the circular lower electrode 5 will be subjected to stress. Depending on the different positions distributed on the sensitized elastic substrate 1, the annular piezoelectric material layer 3 mainly operates in the d 31 mode, and the circular piezoelectric material layer 6 mainly operates in the d 33 mode. The piezoelectric material itself has piezoelectric properties and will generate an electrical signal according to the magnitude of the detected sound pressure. The electrical signal generated by the annular piezoelectric material layer 3 is mainly output through the annular lower electrode 2 and the annular upper electrode 4. The electrical signal generated by the circular piezoelectric material layer 6 is mainly output through the circular lower electrode 5 and the circular upper electrode 7. Finally, the electrical signals output from the annular lower electrode 2 and the annular upper electrode 4 are connected in series with the electrical signals output from the circular lower electrode 5 and the circular upper electrode 7 through platinum wires, and then the signal measurement is realized through a circuit and a test system. By detecting the circuit signal, the magnitude of the actual underwater acoustic signal detected by the MEMS hydrophone can be deduced.

[0070] The above is only the preferred embodiment of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements should also be regarded as within the protection scope of the present invention.

Claims

1. A sensitivity-enhanced MEMS hydrophone, characterized in that Comprising: A sensitized elastic substrate (1), a lower electrode assembly, a PZT piezoelectric sensing assembly, an upper electrode assembly, and an insulating material layer (8); the lower electrode assembly is disposed on the surface of the sensitized elastic substrate (1), the PZT piezoelectric sensing assembly is disposed on the surface of the lower electrode assembly, the upper electrode assembly is disposed on the surface of the PZT piezoelectric sensing assembly, and the insulating material layer (8) is respectively disposed on the surface of the sensitized elastic substrate (1), inside the lower electrode assembly, inside the PZT piezoelectric sensing assembly, and inside the upper electrode assembly to achieve insulation inside the lower electrode assembly, inside the PZT piezoelectric sensing assembly, and inside the upper electrode assembly; both the lower electrode assembly and the upper electrode assembly are led out through conductive cables and are connected in series, and the electrical signal generated by the PZT piezoelectric sensing assembly is output through the lower electrode assembly and the upper electrode assembly and the signal measurement is realized through a circuit and a test system.

2. The sensitized MEMS hydrophone according to claim 1, wherein The lower electrode assembly includes an annular lower electrode (2) and a circular lower electrode (5), the circular lower electrode (5) is disposed inside the annular lower electrode (2), and an insulating material layer (8) is provided between the annular lower electrode (2) and the circular lower electrode (5); both the annular lower electrode (2) and the circular lower electrode (5) are led out through conductive cables.

3. The sensitized MEMS hydrophone according to claim 2, wherein The upper electrode assembly includes an annular upper electrode (4) and a circular upper electrode (7), the circular upper electrode (7) is disposed inside the annular upper electrode (4), and an insulating material layer (8) is provided between the annular upper electrode (4) and the circular upper electrode (7); both the annular upper electrode (4) and the circular upper electrode (7) are led out through conductive cables.

4. The sensitized MEMS hydrophone according to claim 3, characterized in that The PZT piezoelectric sensing assembly includes an annular piezoelectric material layer (3) and a circular piezoelectric material layer (6), the annular piezoelectric material layer (3) is located between the annular lower electrode (2) and the annular upper electrode (4), and the circular piezoelectric material layer (6) is located between the circular lower electrode (5) and the circular upper electrode (7).

5. The sensitized MEMS hydrophone according to claim 4, wherein After the sensitized elastic substrate (1) is subjected to a uniform pressure p, the stress relationship is as follows: Where: p represents the uniform pressure applied to the sensitized elastic substrate (1), μ represents the Poisson's ratio of the sensitized elastic substrate (1), h represents the thickness of the sensitized elastic substrate (1), E represents the elastic modulus of the sensitized elastic substrate (1), R represents the radius of the sensitized structure, and r represents the distance between the force application point and the center of the sensitized structure.

6. The sensitized MEMS hydrophone according to claim 5, characterized in that, The annular piezoelectric material layer (3) operates in the d 31 mode; after the PZT piezoelectric sensing component is stressed, the relationship between the equivalent electric potential generated on the surface of the annular piezoelectric material layer (3) and the stress is as follows: Where: F represents the pressure applied to the piezoelectric material, w represents the length of the piezoelectric material, ε represents the dielectric constant of the piezoelectric material, ε0 represents the permittivity of free space, and d 31 Piezoelectric constant.

7. The sensitized MEMS hydrophone according to claim 5, wherein The circular piezoelectric material layer (6) operates in the d 33 mode; after the PZT piezoelectric sensing component is stressed, the relationship between the equivalent electric potential generated on the surface of the circular piezoelectric material layer (6) and the stress is as follows: Where: F represents the pressure applied to the piezoelectric material, w represents the length of the piezoelectric material, l represents the thickness of the piezoelectric material, ε represents the dielectric constant of the piezoelectric material, ε0 represents the permittivity of free space, and d 33 Piezoelectric constant.

8. The sensitized MEMS hydrophone according to any one of claims 1 to 7, characterized in that, The PZT piezoelectric sensing assembly is prepared from a PZT material or a hybrid material of ZnO material and PZT material.

9. A preparation method for a sensitized MEMS hydrophone according to any one of claims 4 to 7, characterized in that, Including the following steps: Step S1, printing the annular lower electrode (2) and the circular lower electrode (5) on the surface of the sensitized elastic substrate (1) by using a screen printing process; Step S2, printing the annular piezoelectric material layer (3) and the circular piezoelectric material layer (6) on the surfaces of the annular lower electrode (2) and the circular lower electrode (5) respectively by using a screen printing process; Step S3: Use the screen printing process to print the insulating material layer (8) on the surface of the sensitized elastic substrate (1), and the insulating material layer (8) fills the gaps between the annular lower electrode (2) and the circular lower electrode (5), and between the annular piezoelectric material layer (3) and the circular piezoelectric material layer (6); Step S4: Use the screen printing process to print the annular upper electrode (4) and the circular upper electrode (7) on the surfaces of the annular piezoelectric material layer (3) and the circular piezoelectric material layer (6); Step S5: Use conductive cables to lead out the annular lower electrode (2) and the circular lower electrode (5), and the annular upper electrode (4) and the circular upper electrode (7) respectively; Step S6: Use an adhesive to paste and fix the sensitized elastic substrate (1) with the annular lower electrode (2), the annular piezoelectric material layer (3), the annular upper electrode (4), the circular lower electrode (5), the circular piezoelectric material layer (6), the circular upper electrode (7) and the insulating material layer (8) on the splint to achieve peripheral fixation of the sensitized elastic substrate (1).

10. The preparation method according to claim 9, characterized in that, In the said Step S1, the annular lower electrode (2) and the circular lower electrode (5) are fixed on the sensitized elastic substrate (1) by sintering; In the said Step S2, the annular piezoelectric material layer (3) is fixed on the annular lower electrode (2) by sintering, and the circular piezoelectric material layer (6) is fixed on the circular lower electrode (5) by sintering; In the said Step S3, the annular upper electrode (4) is fixed on the annular piezoelectric material layer (3) by sintering, and the circular upper electrode (7) is fixed on the circular piezoelectric material layer (6) by sintering; In the said Step S4, the insulating material layer (8) is fixed on the sensitized elastic substrate (1) by sintering.

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