Integrated fusion type magnetic sensor structure based on multi-source heterogeneous magnetic sensing units

Abstract

This invention relates to the field of sensors, and in particular to an integrated fused magnetic sensor structure based on multi-source heterogeneous magnetic sensing units. The integrated fused magnetic sensor structure based on multi-source heterogeneous magnetic sensing units includes a substrate shell, a solution cavity, and a coilless magnetic core magnetic sensing unit. The substrate shell is hollow inside and open at the top, with an excitation coil mounted on its outer side wall. The solution cavity is fixed inside the substrate shell and has an injection port for filling with a free radical solution. The solution cavity has a hollow through-hole arranged along its central axis and extending through it. The coilless magnetic core magnetic sensing unit is disposed within the hollow through-hole and has a quantum tunneling unit mounted on it. The integrated fused magnetic sensor structure based on multi-source heterogeneous magnetic sensing units described in this invention improves the robustness of the measurement system under dynamic background interference and enhances the accuracy, efficiency, and stability of the magnetic measurement system in practical engineering applications.

Description

Technical Field

[0001] This invention relates to the field of sensors, and in particular to an integrated fused magnetic sensor structure based on multi-source heterogeneous magnetic sensing units. Background Technology

[0002] As one of the Earth's fundamental physical fields, the magnetic field reflects the distribution of matter and geological structure within the Earth. Generally, the Earth's magnetic field serves as a boundary; areas below this range are considered weak magnetic fields. The development of weak magnetic field measuring instruments has significant research value not only in traditional fields such as geophysics and space magnetometry, but also holds immense potential in the medical field, particularly in non-destructive probing of the human body. Based on relatively mature magnetic measurement methods and working principles, various magnetic sensors have emerged. Among them, those widely used in weak magnetic field measurement include fluxgate sensors, inductive magnetic sensors, superconducting quantum interference devices (QFIDs), optically pumped sensors, resonant sensors, and magnetometers, etc.

[0003] Overhauser magnetic sensors show a signal frequency directly proportional to the magnetic field, allowing for accurate magnetic field measurement with simple error tracing and high accuracy. However, they also suffer from gradient-induced frequency aliasing, leading to lower measurement accuracy. Fluxgate sensors exhibit a positive correlation between output voltage and orthogonal magnetic fields, resulting in high sensitivity and resolution. However, their spectral width and linearity are limited by core parameters and environmental factors, leading to poor accuracy. TMR (tunneling magnetoresistive) sensors show a positive correlation between material resistance and orthogonal magnetic fields, offering wide bandwidth, but suffer from significant low-frequency noise. These issues severely restrict the development of high-performance magnetic sensors. Summary of the Invention

[0004] In view of this, the present invention provides an integrated fused magnetic sensor structure based on multi-source heterogeneous magnetic sensing units.

[0005] This invention provides an integrated fused magnetic sensor structure based on a multi-source heterogeneous magnetic sensing unit, comprising a substrate shell, a solution cavity, and a coilless magnetic core sensing unit. The substrate shell is hollow inside and open at the top, with an excitation coil on its outer side wall. The solution cavity is fixed inside the substrate shell and has an injection port for filling with a free radical solution. The solution cavity has a hollow through-hole arranged along its central axis and extending through it. The coilless magnetic core sensing unit is disposed inside the hollow through-hole and has a quantum tunneling unit on it.

[0006] Furthermore, the substrate shell, the solution cavity, and the coilless magnetic core magnetic sensing unit are all cylindrical structures. The hollow through hole is arranged along the axial direction of the solution cavity. The bottom wall of the substrate shell is provided with a through hole communicating with the hollow through hole. The substrate shell, the solution cavity, and the coilless magnetic core magnetic sensing unit are all coaxially arranged.

[0007] Furthermore, the outer wall of the base shell is provided with two annular grooves spaced apart along its axial direction, and each annular groove is provided with the excitation coil.

[0008] Furthermore, the injection port is conical, and there are two of them, both located at the upper end of the solution cavity. The two injection ports are evenly spaced along the circumference of the solution cavity.

[0009] Furthermore, the free radical solution comprises free radicals and an organic solvent, wherein the organic solvent is one of methanol or dimethyl ether.

[0010] Furthermore, the quantum tunneling unit is disposed in the middle of the coilless magnetic core magnetic sensing unit, and includes a free layer, a tunneling layer and a pinned layer arranged sequentially along the axial direction of the coilless magnetic core magnetic sensing unit. The free layer, tunneling layer and pinned layer are all integrally formed with the coilless magnetic core magnetic sensing unit.

[0011] Furthermore, the free layer is made of a ferromagnetic material, the tunneling layer is made of an insulating material, and the pinned layer is made of a ferromagnetic material.

[0012] Furthermore, the coreless magnetic induction unit is made of cobalt-based amorphous material.

[0013] Furthermore, the base shell is made of polyester plastic or titanium material.

[0014] The beneficial effects of the technical solution provided by this invention are as follows: The integrated fused magnetic sensor structure based on multi-source heterogeneous magnetic sensing units described in this invention has the following advantages:

[0015] 1. By optimizing the fusion mechanism and structure, the robustness of the measurement system under dynamic background interference is improved, enabling the fusion sensor to have the advantages of Overhauser high precision, fluxgate high sensitivity and TMR magnetic sensor high bandwidth. In practical applications, the sensor can perform its original performance, improving the accuracy, efficiency and stability of the magnetic measurement system in practical engineering.

[0016] 2. The magnetic sensor's shape, frame, and other components are made of non-magnetic materials, thus avoiding magnetic interference from the substrate material to the sensor's sensitive unit.

[0017] 3. The coil-free structure design ensures that the magnetic induction unit itself is free from coil interference and does not couple with other magnetic induction units, thereby achieving the structural integration of multi-source heterogeneous magnetic induction units. Attached Figure Description

[0018] Figure 1This is a schematic diagram of the integrated fused magnetic sensor structure based on multi-source heterogeneous magnetic sensing units described in this invention (without a substrate shell).

[0019] Figure 2 This is a top view (without a base shell) of an integrated fused magnetic sensor structure based on multi-source heterogeneous magnetic sensing units as described in this invention.

[0020] Figure 3 This is a cross-sectional view of an integrated fused magnetic sensor structure based on multi-source heterogeneous magnetic sensing units, as described in this invention. Detailed Implementation

[0021] The invention will now be further described with reference to the accompanying drawings.

[0022] Please refer to Figure 1-3 The present invention provides an integrated fusion magnetic sensor structure based on a multi-source heterogeneous magnetic sensing unit, including a substrate shell 1, a solution cavity 2, and a coilless magnetic core magnetic sensing unit 3. The substrate shell 1 is hollow inside and open at the top, and an excitation coil 4 is provided on its outer side wall. The solution cavity 2 is fixed inside the substrate shell 1 and has a liquid injection port 5 for filling free radical solution. The solution cavity 2 has a hollow through hole arranged along its central axis and extending through it. The coilless magnetic core magnetic sensing unit 3 is disposed in the hollow through hole, and a quantum tunneling unit 6 is provided on the coilless magnetic core magnetic sensing unit 3.

[0023] In this invention, the substrate shell 1 is made of a non-magnetic material to eliminate magnetic interference from the substrate material. The excitation coil 4 generates both radio frequency (RF) and DC excitation signals. The RF signal generates a polarization magnetic field within the resonant cavity through a conductor. The excitation coil 4 excites the free radical solution within the solution cavity 2, while the DC signal excites the free radical solution through the coil, generating a DC deflection magnetic field. Free radical solution is injected into the solution cavity 2 through the injection port 5, forming a resonant cavity together with the conductor covering the outside of the container. The excitation coil 4 and the solution cavity 2 together form a dynamic nuclear polarization resonance unit. This unit is a magnetic induction unit based on the dynamic nuclear polarization resonance effect. The RF signal excites the electronic system in the free radical solution to an excited state. Due to coupling, the excited electronic system transfers energy to the proton system, also exciting the proton system, achieving electron-proton dual resonance and generating a Larmor signal. This enhances the proton excitation level, thereby increasing the signal-to-noise ratio of the probe output signal, enabling scalar measurement by the sensor, and improving the accuracy of magnetic field measurement. The quantum tunneling unit 6 is a magnetic induction unit based on the tunneling magnetoresistance effect, embedded in the center of the coilless magnetic core induction unit 3. Through the positive correlation between material resistance and orthogonal magnetic fields, it enables high-frequency vector measurement of the sensor, effectively improving the bandwidth of magnetic field measurement. The coilless magnetic core induction unit 3 is a magnetic induction unit based on the flux effect. It directly excites the amorphous magnetic core through the Larmor signal generated by the dynamic nuclear polarization resonance unit, avoiding the mutual coupling problem between the flux effect induction unit and the dynamic nuclear polarization resonance unit's frequency excitation coil 4, Larmor induction coil, etc., enabling low-frequency vector measurement of the sensor and effectively improving the sensitivity and resolution of magnetic field measurement.

[0024] The present invention relates to an integrated fusion magnetic sensor structure based on multi-source heterogeneous magnetic sensing units. Starting from the mechanisms of proton energy level transition, nonlinear magnetization characteristics of iron core materials and magnetoresistive effect, the structure integrates multiple magnetic sensing units based on dynamic nuclear polarization resonance effect, magnetic flux effect and tunneling magnetoresistive effect to construct a novel integrated high-precision multi-parameter fusion magnetic sensor. This enables the new magnetic sensor to have the advantages of high accuracy of Overhauser magnetic sensors, high sensitivity of fluxgate sensors and high response speed of TMR magnetic sensors at the sensor level.

[0025] In the above embodiments, the base shell 1, the solution cavity 2, and the coilless magnetic core magnetic sensing unit 3 are all cylindrical structures. The hollow through hole is arranged along the axial direction of the solution cavity 2. The bottom wall of the base shell 1 is provided with a through hole communicating with the hollow through hole. The base shell 1, the solution cavity 2, and the coilless magnetic core magnetic sensing unit 3 are all coaxially arranged.

[0026] In this invention, the cylindrical base shell 1, the solution cavity 2, and the coilless magnetic core magnetic induction unit 3 facilitate the uniform emission of magnetic field signals. Ideally, the solution cavity 2 is a glass container, with its bottom wall fixedly connected to the bottom inner wall of the base shell 1.

[0027] In the above embodiment, the outer wall of the base shell 1 is provided with two annular grooves spaced apart along its axial direction, and each annular groove is provided with the excitation coil 4.

[0028] In this invention, the excitation coil 4 is arranged in each annular groove to ensure the strength of the generated radio frequency excitation signal and DC excitation signal, thereby realizing the excitation of the free radical solution.

[0029] In the above embodiment, the injection port 5 is conical, and there are two of them, both located at the upper end of the solution cavity 2. The two injection ports 5 are evenly spaced along the circumference of the solution cavity 2.

[0030] In this invention, the injection port 5 is integrally molded with the solution cavity 2. The conical structure of the injection port 5 facilitates the injection of free radical solution and ensures that the solution is not contaminated. In order to ensure the injection speed, the number of injection ports 5 can be increased in practical applications.

[0031] In the above embodiments, the free radical solution is either methanol or dimethyl ether.

[0032] In this invention, it should be noted that the free radicals in this invention refer to atoms, molecules or groups containing unpaired electrons, and are also one of the main substances that can generate electron paramagnetic resonance, such as TEMPONE free radicals.

[0033] In the above embodiment, the quantum tunneling unit 6 is disposed in the middle of the coilless magnetic core magnetic sensing unit 3, and includes a free layer 61, a tunneling layer 62 and a pinned layer 63 arranged sequentially along the axial direction of the coilless magnetic core magnetic sensing unit. The free layer 61, the tunneling layer 62 and the pinned layer 63 are all integrally formed with the coilless magnetic core magnetic sensing unit 3.

[0034] In this invention, the quantum tunneling unit 6 and the coilless magnetic core magnetic induction unit 3 are integrally molded, which can reduce the size and weight of the sensor and lower the production cost. The structure of the quantum tunneling unit 6 mainly includes a free layer 61, a tunneling layer 62, and a pinned layer 63, similar to a "sandwich" structure. The polarization direction of the free layer 61 is affected by the magnitude and direction of the applied magnetic field; the tunneling layer 62 is a thin non-ferromagnetic insulating layer; the polarization direction of the pinned layer 63 is fixed by the coupling between the pinned layer 63 and the antiferromagnetic layer. By changing the magnitude and direction of the applied magnetic field, the angle between the polarization directions of the free layer 61 and the pinned layer 63 can be changed, causing a change in the tunneling resistance, which is called the tunnel magnetoresistance. The change in resistance is the TMR effect. In the tunnel junction, due to the different coercivities of the two ferromagnetic layers, when saturated, the magnetization directions of the two ferromagnetic layers are parallel to each other. When reverse-magnetized, the magnetization directions of the two ferromagnetic layers become antiparallel. This is because the magnetization vector of the ferromagnetic layer with lower coercivity flips first. Therefore, the magnetization directions of the two ferromagnetic layers can be changed by altering the way the external magnetic field is changed, thereby changing their resistance, i.e., producing the TMR effect.

[0035] In the above embodiments, the free layer 61 is made of ferromagnetic material, the tunneling layer 62 is made of insulating material, and the pinned layer 63 is made of ferromagnetic material.

[0036] In this invention, both the free layer and the pinned layer are metallic ferromagnetic layers composed of ferromagnetic materials; the tunneling layer is a non-ferromagnetic insulating layer with a thickness of 1-2 nm, generally composed of MgO or Al2O3; the magnetic moment of the free layer is relatively free and rotatable relative to the magnetic moment of the pinned layer, and it flips with the change of the external field; the pinned layer is composed of a ferromagnetic layer and an antiferromagnetic layer, and the exchange coupling between the ferromagnetic layer and the antiferromagnetic layer determines the direction of the magnetic moment of the ferromagnetic layer.

[0037] In the above embodiments, the coilless magnetic core magnetic induction unit is made of cobalt-based amorphous material.

[0038] In this invention, the coilless magnetic core magnetic sensing unit 3 is a thin cylindrical structure with a hollow interior, which can effectively utilize the magnetic flux effect while reducing the weight and production cost of the sensor. Furthermore, the coilless magnetic core magnetic sensing unit 3 employs a coilless structure design, eliminating mutual interference between coils. Specifically, the thickness of a single-layer coilless magnetic core magnetic sensing unit in this invention is 0.025 mm. The cobalt-based amorphous wire possesses high permeability, low coercivity, and good temperature characteristics, resulting in better output signal from the magnetic sensing unit.

[0039] In the above embodiments, the base shell 1 is made of polyester plastic or titanium material.

[0040] In this invention, non-magnetic materials such as polyester plastic and titanium constitute the skeleton structure of the magnetic sensor, which has the advantages of low implementation cost.

[0041] Of course, the above are only preferred embodiments of the present invention and are not intended to limit the scope of application of the present invention. Therefore, any equivalent changes made to the principle of the present invention should be included within the protection scope of the present invention.

Claims

1. An integrated fusion magnetic sensor structure based on multi-source heterogeneous magnetic sensing units, characterized in that, The device includes a base shell, a solution cavity, and a coilless magnetic core magnetic sensing unit. The base shell is hollow inside and open at the top, with an excitation coil on its outer side wall. The solution cavity is fixed inside the base shell and has an injection port for filling with free radical solution. The solution cavity has a hollow through-hole arranged along its central axis and extending through it. The coilless magnetic core magnetic sensing unit is disposed inside the hollow through-hole and has a quantum tunneling unit on it. The substrate shell, the solution cavity, and the coilless magnetic core induction unit are all cylindrical structures. The hollow through-hole is arranged along the axial direction of the solution cavity. The bottom wall of the substrate shell has a through-hole communicating with the hollow through-hole. The substrate shell, the solution cavity, and the coilless magnetic core induction unit are all coaxially arranged. The outer wall of the substrate shell has two annular grooves spaced apart along its axial direction. Each annular groove contains the excitation coil. The quantum tunneling unit is located in the middle of the coilless magnetic core induction unit. It includes a free layer, a tunneling layer, and a pinned layer arranged sequentially along the axial direction of the coilless magnetic core induction unit. The free layer, tunneling layer, and pinned layer are all integrally formed with the coilless magnetic core induction unit.

2. The integrated fusion magnetic sensor structure based on multi-source heterogeneous magnetic sensing units according to claim 1, characterized in that, The injection port is conical and has two ports, both located at the upper end of the solution cavity. The two injection ports are evenly spaced along the circumference of the solution cavity. 3.The integrated fusion magnetic sensor structure based on multi-source heterogeneous magnetic sensing units according to claim 1, wherein, The free radical solution comprises free radicals and an organic solvent, wherein the organic solvent is one of methanol or dimethyl ether.

4. The integrated fusion magnetic sensor structure based on multi-source heterogeneous magnetic sensing units according to claim 1, characterized in that, The free layer is made of ferromagnetic material, the tunneling layer is made of insulating material, and the pinned layer is made of ferromagnetic material.

5. The integrated fusion magnetic sensor structure based on multi-source heterogeneous magnetic sensing units according to claim 1, characterized in that, The coilless magnetic core magnetic induction unit is made of cobalt-based amorphous material.

6. The integrated fusion magnetic sensor structure based on multi-source heterogeneous magnetic sensing units according to claim 1, characterized in that, The base shell is made of polyester plastic or titanium material.

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