Magnetoelectric sensor based on hollow oscillator structure and preparation method thereof

Abstract

The invention discloses a magnetoelectric sensor based on a hollow vibrator structure and a preparation method thereof, the magnetoelectric sensor comprises a piezoelectric material and a magnetostrictive material, the piezoelectric material is a hollow vibrator structure, and the magnetostrictive material is bonded on the surface of the piezoelectric material to form the magnetoelectric sensor. According to the hollow vibrator structure prepared through high-precision methods such as laser cutting and chemical wet etching, the size and the weight of the sensor are reduced, and the mechanical performance and the vibration characteristic of the sensor are optimized. By means of the design, the high sensitivity of the sensor is kept, and meanwhile the response speed and stability of the sensor are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of sensors, and in particular relates to a magnetoelectric sensor based on a hollow vibrator structure and a preparation method thereof. Background Art

[0002] Magnetic sensors can measure key physical quantities such as magnetic field and current, and have large-scale applications in various fields. Magnetic sensors have developed into a branch of the modern sensor industry and are widely used in industry, national defense, science and technology, and medical fields. There are many types of magnetic sensors. The existing types of magnetic sensors include magnetoelectric sensors, fluxgate sensors, Hall sensors, magnetoresistive sensors, magnetic resonance magnetometers, and superconducting quantum interference devices (SQUIDs). Among them, although the power consumption and volume of magnetoresistive sensors are small, the resolution is low, and the sensitivity at low frequencies is difficult to improve, and the detection limit is about 1 nT; the sensitivity and resolution of fluxgate sensors are better than those of magnetoresistive sensors, but they have higher requirements for the performance of the magnetic core and the winding of the coil. At the same time, improving the low-frequency sensitivity of fluxgate sensors is also an important technical problem; the resolution of optically pumped magnetic sensors is high, but the volume is large, the structure is complex, and the price is expensive; SQUID is the magnetic sensor with the highest resolution at present, which can reach the fT level, but it also has the problem of large volume and high price, and must also work in an ultra-low temperature liquid helium environment. Summary of the invention

[0003] The object of the present invention is to provide a magnetoelectric sensor based on a hollow vibrator structure and a preparation method thereof to solve the above-mentioned problems.

[0004] To achieve the above object, the present invention adopts the following technical solutions: The magnetoelectric sensor based on the hollow vibrator structure includes a piezoelectric material and a magnetostrictive material. The piezoelectric material is a hollow vibrator structure, and the magnetostrictive material is bonded to the surface of the piezoelectric material to form the magnetoelectric sensor.

[0005] Furthermore, an upper electrode surface and a lower electrode surface are respectively provided on two opposite surfaces in the thickness direction of the piezoelectric material.

[0006] Furthermore, the piezoelectric material is one of AlN, quartz, LiNbO3, BaTiO3, ZnO, Pb(Zr, Ti)O3, Pb(Mg, Nb)O3-PbTiO3, Pb(Zn, Nb)O3-PbTiO3 or BiScO3-PbTiO3.

[0007] Furthermore, the magnetostrictive material is an alloy or oxide having a magnetostrictive effect, or a magnetostrictive composite material formed by combining them with a polymer, and is in the form of a single-layer or multi-layer sheet.

[0008] Furthermore, metals, alloys or oxides having magnetostrictive effect include iron, cobalt, nickel, manganese, Metglas, terbium-dysprosium-iron alloy, nickel-manganese-gallium alloy, iron-gallium alloy, nickel-iron oxide, cobalt-iron oxide, or manganese-zinc oxide.

[0009] Furthermore, the material of the upper electrode surface and the lower electrode surface is one of Au, Ag, Al, Cu, Pt, W, Fe, Co, Ni or Ti.

[0010] Furthermore, the piezoelectric material has a length of 0.01-1000 mm, a width of 0.01-1000 mm, and a thickness of 0.001-10 mm; the magnetostrictive material has a length of 0.01-1000 mm, a width of 0.01-1000 mm, and a thickness of 0.001-10 mm.

[0011] Furthermore, the magnetostrictive material is a single-layer structure or a multi-layer structure.

[0012] A method for preparing a magnetoelectric sensor based on a hollow vibrator structure comprises: The piezoelectric material is processed into a set size and shape to form a hollow vibrator structure, and then ultrasonically cleaned with ultrapure water; Electrodes are plated on the upper and lower ends of the surface of the piezoelectric material by annealing, evaporation or magnetron sputtering; The piezoelectric material is polarized along the thickness direction after the electrode is made; Two wires are respectively attached to the two electrode end surfaces of the piezoelectric material to conduct electrical signals; Process the magnetostrictive material into the set size and shape, and clean it with alcohol; A single layer or multiple layers of magnetostrictive material are bonded to the surface or upper and lower surfaces of a piezoelectric material using an adhesive to form a magnetoelectric composite material, thereby manufacturing a magnetoelectric sensor based on a hollow vibrator structure.

[0013] Furthermore, the hollowed-out oscillator structure is prepared by laser cutting, chemical wet etching, plasma etching, reactive gas etching or electron beam etching.

[0014] Compared with the prior art, the present invention has the following technical effects: The hollow vibrator structure prepared by high-precision methods such as laser cutting and chemical wet etching not only reduces the volume and weight of the sensor, but also optimizes the mechanical properties and vibration characteristics of the sensor. This design allows the sensor to maintain high sensitivity while also improving its response speed and stability.

[0015] Piezoelectric materials (such as AlN, BaTiO3, etc.) can convert mechanical energy into electrical energy, while magnetostrictive materials (such as Metglas, Terfenol-D, etc.) can deform under the action of a magnetic field. The two materials are combined together with a binder to form a composite material with magnetoelectric conversion function, which is the key to realizing magnetic field detection.

[0016] Using Au, Ag and other metals with good conductivity as electrode materials ensures stable signal transmission. At the same time, these metals also have good corrosion resistance and stability, which prolongs the service life of the sensor.

[0017] The electrodes on the upper and lower surfaces of the piezoelectric material are led out through wires, which facilitates connection with external circuits to realize signal collection and processing. This design simplifies the use process of the sensor and improves its practicality.

[0018] High-precision processing methods such as laser cutting and chemical wet etching are used to ensure the accuracy and consistency of the sensor structure. This helps to improve the sensitivity and repeatability of the sensor.

[0019] The key step to achieve the piezoelectric effect is to prepare electrodes by annealing, evaporation or magnetron sputtering, and polarize the piezoelectric material along the thickness direction. The polarized piezoelectric material can convert mechanical energy into electrical energy more efficiently.

[0020] The magnetostrictive material is bonded to the surface of the piezoelectric material using an adhesive to form a composite material with magnetoelectric conversion function. This composite method is simple and easy to implement, and can ensure a close bond between the two materials.

[0021] Due to the hollow vibrator structure and efficient magnetoelectric conversion materials, the sensor has a high sensitivity to weak signal AC magnetic fields, which makes the sensor show great advantages in weak magnetic field detection.

[0022] Because the sensor is small in size, highly sensitive, and can meet different performance requirements by adjusting material selection and structural design, it has a wide range of applications and can be used in many fields such as medical treatment, environmental monitoring, and security.

[0023] The stability and reliability of the sensor are ensured through fine processing and high-quality material selection. This enables the sensor to maintain stable performance during long-term use.

[0024] In summary, the magnetoelectric sensor based on the hollow vibrator structure proposed in this technical solution has shown significant advantages in structural design, material selection, manufacturing process and technical effect. This sensor is not only small in size and highly sensitive, but also has a wide range of applications and good stability and reliability, providing a new solution for weak magnetic field detection and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the present invention.

[0026] Among them: 1. piezoelectric material; 2. magnetostrictive material; 3. upper electrode surface of piezoelectric material; 4. lower electrode surface of piezoelectric material.

[0027] Figure 2 It is a schematic diagram of the working mode of the magnetoelectric sensor based on the hollow vibrator structure of the present invention.

[0028] Figure 3 This is a frequency response test diagram of the magnetoelectric sensor based on the hollow vibrator structure of the present invention under the optimal bias magnetic field.

[0029] Figure 4 This is a test result diagram of the AC magnetic field sensitivity of the magnetoelectric sensor based on the hollow vibrator structure of the present invention. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings: Example 1, please refer to Figure 1 The present invention provides a magnetoelectric sensor based on a hollow vibrator structure, including a piezoelectric material 1 and a magnetostrictive material 2. The piezoelectric material 1 is a hollow vibrator structure, and the magnetostrictive material 2 is bonded to the surface of the piezoelectric material 1 to form a magnetoelectric sensor.

[0031] Piezoelectric materials can convert mechanical energy into electrical energy, while magnetostrictive materials can deform under the action of a magnetic field. The two materials are combined together with a binder to form a composite material with magnetoelectric conversion function, which is the key to realizing magnetic field detection.

[0032] Embodiment 2, the present invention provides a magnetoelectric sensor based on a hollow vibrator structure, specifically comprising: A magnetoelectric sensor based on a hollow vibrator structure includes a piezoelectric material 1 and a magnetostrictive material 2; two wires are respectively connected to the upper and lower surface electrodes of the piezoelectric material 1; an adhesive is used to bond the magnetostrictive material 2 to one surface or the upper and lower surfaces of the piezoelectric material 1; the piezoelectric material 1 includes an upper electrode surface 3 and a lower electrode surface 4; the piezoelectric material 1 is a thin sheet structure; and the magnetostrictive material is a thin sheet structure. Figure 1 .a is a circular oscillator structure, Figure 1 .b is the longitudinal oscillator structure, Figure 1 .c is a bent oscillator structure.

[0033] The piezoelectric material 1 is a single crystal or polycrystalline ceramic material, specifically AlN, quartz, LiNbO3, BaTiO3, ZnO, Pb(Zr, Ti)O3, Pb(Mg, Nb)O3-PbTiO3, Pb(Zn, Nb)O 3- One of PbTiO3 or BiScO3-PbTiO3.

[0034] The magnetostrictive material 2 is an alloy or oxide having a magnetostrictive effect or a magnetostrictive composite material formed by combining them with a polymer, and is in the form of a multilayer sheet. The metal or alloy or oxide having a magnetostrictive effect includes iron, cobalt, nickel, manganese, Metglas, nickel-manganese-gallium alloy, iron-gallium alloy [Fe-Ga], terbium-dysprosium-iron alloy [Terfenol-D (Tb 0.27- 0.30 Dy 0.73-0.70 Fe 1.90-1.95 )], nickel manganese gallium alloy (Ni2MnGa), nickel iron oxide (NiFe2O4), cobalt iron oxide (CoFe2O4), manganese zinc ferrite (MnZnO3), etc., or a magnetostrictive composite material formed by the above magnetostrictive material and a polymer. The magnetostrictive material can be a single-layer structure or a multi-layer structure.

[0035] When the magnetic field sensor is working, the magnetostrictive material expands, contracts, or bends along its length under the action of the magnetic field, and the piezoelectric material produces strain driven by the deformation of the magnetostrictive material. Positive and negative charges gather on the upper and lower surfaces of the piezoelectric material and output signals through wires.

[0036] Embodiment 3, a method for manufacturing a magnetoelectric sensor based on a hollow vibrator structure, comprises the following steps: Step 1, providing a piezoelectric material, processing the piezoelectric material into a required size and shape, removing excess parts, hollowing out the required vibrator structure, and ultrasonically cleaning it with ultrapure water; Step 2, electrodes are plated on the upper and lower ends of the surface of the piezoelectric material by annealing, evaporation or magnetron sputtering; Step 3, the piezoelectric material is polarized along the thickness direction after the electrode is made; Step 4, two wires are respectively attached to two electrode end surfaces of the piezoelectric material to conduct electrical signals; Step 5, providing a magnetostrictive material, processing the magnetostrictive material into a required size and shape, and cleaning it with alcohol; Step 6: Use adhesive to bond a single layer or multiple layers of magnetostrictive material to the surface or upper and lower surfaces of the piezoelectric material to form a magnetoelectric composite material, thereby manufacturing a magnetoelectric sensor based on a hollow vibrator structure.

[0037] Figure 2This is a schematic diagram of the working mode of the magnetoelectric sensor based on the hollow vibrator structure of the present invention: under an AC magnetic field, the magnetostrictive material expands and contracts, and reciprocates under the AC magnetic field, driving the piezoelectric material to move, and outputting an electrical signal through a wire. Figure 1 .a is a schematic diagram of the vibration state of the circular oscillator structure. Figure 1 .b is a schematic diagram of the vibration state of the longitudinal oscillator structure. Figure 1 .c is a schematic diagram of the vibration state of the bending oscillator structure.

[0038] Figure 3 This is a frequency response test diagram of the magnetoelectric sensor based on the hollow vibrator structure of the present invention. Under the optimal magnetic field bias of the sensor of the present invention, the magnetoelectric coefficients of the magnetoelectric sensors with circular vibrator structure, longitudinal vibrator structure, and bending vibrator structure at resonance are 13.3 V / (cm Oe), 15.2 V / (cm Oe), and 2.17 V / (cm Oe), respectively.

[0039] Figure 4 The figures are test results of the AC magnetic field sensitivity of the magnetoelectric sensor based on the hollow vibrator structure of the present invention. a and b are the test results of the AC magnetic field sensitivity of the bending vibrator of the present invention at an operating frequency of 1 kHz and the test results of the AC magnetic field sensitivity at a resonant operating frequency, respectively, with detection limits of 3.61 nT and 39.49 pT, respectively. c and d are the test results of the AC magnetic field sensitivity of the circular vibrator of the present invention at an operating frequency of 1 kHz and the test results of the AC magnetic field sensitivity at a resonant operating frequency, respectively, with detection limits of 0.967 nT and 7.99 pT, respectively. e and f are the test results of the AC magnetic field sensitivity of the longitudinal vibrator of the present invention at an operating frequency of 1 kHz and the test results of the AC magnetic field sensitivity at a resonant operating frequency, respectively, with detection limits of 0.784 nT and 6.28 pT, respectively.

[0040] The above embodiments of the present invention are merely examples for illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes and modifications can be made based on the above description. It is impossible to list all the embodiments here. Any obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A magnetoelectric sensor based on a hollow vibrator structure, characterized in that: It comprises a piezoelectric material (1) and a magnetostrictive material (2), wherein the piezoelectric material (1) is a hollow vibrator structure, and the magnetostrictive material (2) is bonded to the surface of the piezoelectric material (1) to form a magnetoelectric sensor.

2. The magnetoelectric sensor based on the hollow vibrator structure according to claim 1 is characterized in that: An upper electrode surface (3) and a lower electrode surface (4) are respectively arranged on two opposite surfaces in the thickness direction of the piezoelectric material (1).

3. The magnetoelectric sensor based on the hollow vibrator structure according to claim 1, characterized in that: The piezoelectric material (1) is one of AlN, quartz, LiNbO3, BaTiO3, ZnO, Pb(Zr, Ti)O3, Pb(Mg, Nb)O3-PbTiO3, Pb(Zn, Nb)O3-PbTiO3 or BiScO3-PbTiO3.

4. The magnetoelectric sensor based on the hollow vibrator structure according to claim 1, characterized in that: The magnetostrictive material (2) is a metal, alloy or oxide having a magnetostrictive effect, or a magnetostrictive composite material formed by combining them with a polymer, and is in the form of a single-layer or multi-layer thin sheet.

5. The magnetoelectric sensor based on the hollow vibrator structure according to claim 4 is characterized in that: Metals, alloys or oxides having magnetostrictive effect include iron, cobalt, nickel, manganese, Metglas, terbium-dysprosium-iron alloy, nickel-manganese-gallium alloy, iron-gallium alloy, nickel-iron oxide, cobalt-iron oxide, or manganese-zinc oxide, etc.

6. The magnetoelectric sensor based on the hollow vibrator structure according to claim 1, characterized in that: The material of the upper electrode surface (3) and the lower electrode surface (4) is one of Au, Ag, Al, Cu, Pt, W, Fe, Co, Ni or Ti.

7. The magnetoelectric sensor based on the hollow vibrator structure according to claim 1, characterized in that: The length of the piezoelectric material is 0.01-1000 mm, the width is 0.01-1000 mm, and the thickness is 0.001-10 mm; the length of the magnetostrictive material is 0.01-1000 mm, the width is 0.01-1000 mm, and the thickness is 0.001-10 mm.

8. The magnetoelectric sensor based on the hollow vibrator structure according to claim 7, characterized in that: The magnetostrictive material has a single-layer structure or a multi-layer structure.

9. The method for preparing a magnetoelectric sensor based on a hollow vibrator structure according to any one of claims 1 to 8, characterized in that: include: The piezoelectric material is processed into a set size and shape to form a hollow vibrator structure, and then ultrasonically cleaned with ultrapure water; Electrodes are plated on the upper and lower ends of the surface of the piezoelectric material by annealing, evaporation or magnetron sputtering; The piezoelectric material is polarized along the thickness direction after the electrode is made; Two wires are respectively attached to the two electrode end surfaces of the piezoelectric material to conduct electrical signals; Process the magnetostrictive material into the set size and shape, and clean it with alcohol; A single layer or multiple layers of magnetostrictive material are bonded to the surface or upper and lower surfaces of a piezoelectric material using an adhesive to form a magnetoelectric composite material, thereby manufacturing a magnetoelectric sensor based on a hollow vibrator structure.

10. The method for preparing a magnetoelectric sensor based on a hollow vibrator structure according to claim 9, characterized in that: The hollow oscillator structure is prepared by laser cutting, chemical wet etching, plasma etching, reactive gas etching or electron beam etching.

Images