Optoelectromagnetic field intensity sensor for ferromagnetic structure topography damage detection

Abstract

The utility model provides a kind of photoelectromagnetic field intensity sensor for ferromagnetic structure topography damage detection, including chip, magnetic fluid film and substrate, chip includes the LED light ray emitting module being set on substrate, the PD light ray receiving module being set on substrate, P electrode, N electrode and sapphire upper substrate layer;LED light ray emitting module, PD light ray receiving module are respectively with corresponding P electrode and N electrode conduction, PD light ray receiving module is distributed in the circumference of LED light ray emitting module, sapphire upper substrate layer is set on the upper surface of LED light ray emitting module and PD light ray receiving module;Magnetic fluid film is set on sapphire upper substrate layer, and magnetic fluid film is located above PD light ray receiving module and LED light ray emitting module.The utility model sensor is strong in anti-interference ability, accurate in testing, and high in sensitivity.

Description

Technical Field

[0001] This utility model relates to the field of morphology detection, and in particular to a photoelectric magnetic field strength sensor for detecting morphological damage in ferromagnetic structures. Background Technology

[0002] Ferromagnetic materials, primarily composed of steel and its alloys, possess excellent mechanical properties such as strength, hardness, plasticity, and toughness, and are widely used in various fields of industrial production, including structural components in bridges, ships, oil and gas pipelines, railways, aerospace, transportation, and petrochemical industries. These components or equipment typically operate under high-speed, high-temperature, high-pressure, and high-load environments. Under the influence of fatigue loads, internal working media, or external environmental factors, they are prone to various types of damage, such as corrosion and cracking, at points of structural inhomogeneity, porous areas, voids, and areas with concentrated dislocation defects. This not only reduces the service life of the equipment but can also lead to major safety accidents. Therefore, timely, efficient, and non-destructive testing of damaged areas in ferromagnetic components is of great significance for preventing component fracture and major safety accidents.

[0003] Damage detection is crucial for manufacturing, and common methods include electromagnetic detection, ultrasonic detection, and thermal imaging. Some capacitive and piezoelectric sensors are also used for morphological integrity and health monitoring of ferromagnetic materials. Eddy current sensing methods are widely used for damage detection in conductive materials. Capacitive and inductive micro-displacement sensors are primarily used for structural defect detection. While these methods offer high sensitivity, they face challenges such as complex structures, inaccurate measurement calibration, and susceptibility to electromagnetic interference. Especially in harsh industrial environments, distributed multi-point online monitoring is difficult to achieve. Currently, many damage detection methods are based on ultrasonic, thermal imaging, and CCD sensors, combining sensor imaging technology with machine learning to achieve high-resolution automated detection. However, these methods typically require expensive sensor arrays. Furthermore, the measured images are susceptible to background noise, leading to complex data processing. Therefore, there is an urgent need for a photoelectric magnetic field strength sensor with strong anti-interference capabilities, high accuracy, and high sensitivity for morphological damage detection in ferromagnetic structures. Utility Model Content

[0004] In order to overcome the shortcomings of the existing technology, the purpose of this utility model is to provide a photoelectric magnetic field strength sensor with strong anti-interference ability and accurate testing for detecting damage to ferromagnetic structures.

[0005] The objective of this utility model is achieved through the following technical solution:

[0006] A photoelectric magnetic field strength sensor for detecting morphological damage in ferromagnetic structures includes a chip, a magnetofluidic film, and a substrate. The chip includes an LED light emitting module, a PD light receiving module, a P electrode, an N electrode, and a sapphire upper substrate layer disposed on the substrate. The LED light emitting module and the PD light receiving module are respectively connected to the corresponding P electrode and N electrode. The PD light receiving modules are distributed around the LED light emitting module. The sapphire upper substrate layer is disposed on the upper surface of the LED light emitting module and the PD light receiving module. The magnetofluidic film is disposed on the sapphire upper substrate layer and is located above the PD light receiving module and the LED light emitting module.

[0007] Preferably, it further includes a frame-shaped resin mold disposed on the sapphire substrate, wherein the inner frame of the frame-shaped resin mold and the upper surface of the sapphire substrate form a groove-shaped structure, and the magnetofluid film is filled in the groove-shaped structure.

[0008] Preferably, it also includes a sealing shell, which is fitted onto the substrate. The LED light emitting module, PD light receiving module, sapphire upper substrate layer and frame-shaped resin mold are all located inside the sealing shell. The sealing shell encloses the magnetofluid membrane in a groove-shaped structure. The sealing shell is made of a non-magnetic material.

[0009] Preferably, the sealing shell is made of PDMS material.

[0010] Preferably, it further includes a lower substrate layer disposed on the upper surface of the substrate.

[0011] Preferably, an ITO current spreading layer is provided on the upper surface of the lower substrate layer.

[0012] Preferably, the lower substrate is made of a light-transmitting material, and a Bragg reflector is provided on the lower surface of the lower substrate.

[0013] Preferably, the substrate is provided with a power input interface and a light intensity signal output interface, and the P electrode and N electrode are electrically connected to the power input interface.

[0014] Preferably, a mask pattern is provided between the PD light receiving module and the LED light emitting module.

[0015] Compared with existing photoelectric magnetic field strength sensors for detecting morphological damage in ferromagnetic structures, the photoelectric magnetic field strength sensor of this invention has the following advantages:

[0016] By integrating a PD light receiving module with an LED light emitting module, and applying an external magnetic field, when the sensor scans the surface of a defect-free ferromagnetic material, the magnetic field strength changes, the arrangement of the magnetofluid within the magnetofluid film changes, and the refractive index of the magnetofluid film at the corresponding position changes. The PD light receiving module receives light intensity reflected by the magnetofluid film, and thus the photocurrent intensity received by the PD light receiving module provides feedback on the morphology of the ferromagnetic structure. Based on a pre-plotted curve showing the relationship between magnetic field strength and magnetofluid refractive index, morphological damage and defects of the ferromagnetic structure can be detected by observing changes in the intensity of the reflected photocurrent. Accurate results can be obtained simply by ensuring the stability of the externally applied magnetic field. It has strong anti-interference ability, high sensitivity, requires no measurement calibration, and has a simple structure. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the photoelectric magnetic field strength sensor chip used for detecting morphological damage in ferromagnetic structures according to this invention.

[0018] Figure 2 This is the curve showing the relationship between magnetic field strength and the refractive index of the magnetohydrodynamic fluid.

[0019] Among them: 10, sapphire substrate layer; 20, LED light emitting module; 30, PD light receiving module; 40, substrate; 50, P electrode; 60, N electrode; 70, magnetofluid film; 80, sealing shell. Detailed Implementation

[0020] To make the technical problem solved by this utility model, the technical solution adopted, and the technical effect achieved clearer, the technical solution of the embodiments of this utility model will be further described in detail below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0021] like Figure 1-2This embodiment provides a photoelectric magnetic field strength sensor for detecting morphological damage in ferromagnetic structures, including a chip, a magnetofluidic film 70, and a substrate 40. The chip includes an LED light emitting module 20, a PD light receiving module 30, a P electrode 50, an N electrode 60, and a sapphire upper substrate layer 10 disposed on the substrate 40. The LED light emitting module 20 and the PD light receiving module 30 are respectively connected to the corresponding P electrode 50 and N electrode 60. The PD light receiving modules 30 are distributed around the LED light emitting module 20. The sapphire upper substrate layer 10 is disposed on the upper surface of the LED light emitting module 20 and the PD light receiving module 30. The magnetofluidic film 70 is disposed on the sapphire upper substrate layer 10 and is located above the PD light receiving module 30 and the LED light emitting module 20.

[0022] Working principle: During use, a magnet is fixed to the back of the sensor to generate a fixed magnetic field, magnetizing the ferromagnetic material and maintaining a stable state by distributing the molecules within the magnetofluid in a certain regular pattern. Powering on activates the LED light emitting module 20 and the PD light receiving module 30. The surface of the magnetofluid film 70 is brought close to the ferromagnetic material under test while maintaining a certain distance. The magnetic field strength at the sensor location corresponding to the defective ferromagnetic material under test will change the refractive index of the magnetofluid. The light emitted by the LED light emitting module 20 is reflected at the interface between the sapphire and the magnetofluid. The PD light receiving module 30 receives this reflected light and feeds back the photocurrent intensity, thus indicating the magnetic field strength at the detection point.

[0023] When detecting the morphology of ferromagnetic materials, a magnet on the back of the sensor generates a magnetic field to magnetize the ferromagnetic material, causing it to generate a magnetic field in space and maintaining stability within the magnetofluid. A displacement stage is used to maintain a certain relative distance between the surface of the magnetofluid film 70 and the ferromagnetic structure under test. The sensor is moved by scanning. The arrangement of the magnetofluid within the magnetofluid film 70 changes, and the refractive index of the magnetofluid at the corresponding location changes with the magnetic field at the chip's location. Different morphologies of ferromagnetic materials generate different magnetic field strengths at the same relative position, resulting in different refractive indices of the magnetofluid at that location. For ferromagnetic structures with defects or cracks, during the scanning process, smooth and intact parts at the same relative position will... When a magnetic field of the same magnitude is generated, the refractive index of the magnetic fluid remains unchanged, but the magnetic field generated at the defect will change, thus causing a change in the refractive index of the magnetic fluid. The light emitted by the LED light emitting module 20 is reflected at the interface between the sapphire and the magnetic fluid. The different refractive indices of the magnetic fluid cause different incident angles of the light, which in turn cause different intensities of the reflected light received by the PD light receiving module 30. In the detection of the magnetic field of a magnetized material (such as an electromagnet) at a certain position in space, the sensor is placed at the designated position. The magnetic field strength at this position affects the refractive index of the magnetic fluid, thereby affecting the photocurrent intensity detected by the sensing chip, thus realizing the detection of the change in the magnetic field strength generated by the magnetic material in space.

[0024] Due to the rearrangement caused by the magnetic field of the magnetofluid, in order to ensure the overall shape of the magnetofluid film 70, a frame-shaped resin mold is also included on the sapphire substrate 10. The inner frame of the frame-shaped resin mold and the upper surface of the sapphire substrate 10 form a groove-shaped structure, and the magnetofluid film 70 is filled in the groove-shaped structure. Furthermore, the thickness of the magnetofluid film 70 is 0.2 μm to 10 μm.

[0025] To protect the magnetofluid membrane 70, a sealing shell 80 is also included. The sealing shell 80 covers the substrate 40. The LED light emitting module 20, the PD light receiving module 30, the sapphire upper substrate layer 10, and the frame-shaped resin mold are all located inside the sealing shell 80. The sealing shell 80 encloses the magnetofluid membrane 70 within a groove-like structure. The sealing shell 80 is made of a non-magnetic material. The non-magnetic material of the sealing shell 80 does not affect the distribution of the magnetic field, ensuring that the magnetofluid can respond sensitively to changes in the magnetic field strength.

[0026] Furthermore, the sealing shell 80 is made of PDMS material. The PDMS sealing shell 80 is a non-magnetic material and is deformable, adapting to changes in the shape of the magnetofluid membrane 70. When the defects on the surface of the ferromagnetic structural component are severe, the magnetofluid arrangement at the corresponding location changes significantly, potentially causing substantial changes in the local shape of the magnetofluid membrane 70. Using the PDMS sealing shell 80 does not restrict the changes in the magnetofluid membrane 70, ensuring that the magnetofluid makes a precise and sensitive arrangement according to changes in the magnetic field.

[0027] The inner wall of the sealed shell 80 may also be provided with a non-magnetic reflective material to prevent light transmission caused by the small thickness of the magnetic fluid film 70, ensuring that the intensity of the light reflected by the magnetic fluid film 70 is high, so that the photocurrent intensity signal received by the PD light receiving module 30 is strong, and improving the accuracy of the test.

[0028] It also includes a lower substrate layer, which is disposed on the upper surface of the substrate 40.

[0029] An ITO current spreading layer is provided on the upper surface of the lower substrate layer.

[0030] The lower substrate is made of a light-transmitting material, and a Bragg reflector is provided on the lower surface of the lower substrate. To improve testing accuracy, the light from the LED light emitting module 20 is reflected by the Bragg reflector and then reflected onto the magnetofluid film 70, ensuring the consistency of optical parameters in the testing environment.

[0031] The substrate 40 is provided with a power input interface and a light intensity signal output interface. The P electrode 50 and the N electrode 60 are electrically connected to the power input interface. The power input interface and the light intensity signal output interface on the substrate 40 are respectively connected to an external power supply and a light intensity signal display.

[0032] To prevent the light emitted by the LED light emitting module 20 from being captured by the PD light receiving module 30 without being reflected by the magnetofluid membrane 70, a mask pattern is provided between the PD light receiving module 30 and the LED light emitting module 20.

[0033] The preparation method of the sensor of this utility model:

[0034] S1. A 6μm thick LED epitaxial structure composed of InGaN / GaN multiple quantum wells was grown on a 4-inch upper substrate using metal-organic chemical vapor deposition (MOCVD) technology, and an LED light emitting module 20 and a PD light receiving module 30 were set accordingly.

[0035] S2. A 0.12-μm thick indium tin oxide (ITO) layer was deposited on the p-GaN surface as a current spreading layer;

[0036] S3. Define a mask pattern with a spacing of 10μm between the LED light emitting module 20 and the PD light receiving module 30, and etch the exposed GaN spacing onto the sapphire substrate layer 10 using ICP.

[0037] S4. P and N electrodes with a thickness of 1.65 μm were evaporated on the bare current spreading layer and n-GaN, respectively.

[0038] S5. A 0.36-μm thick SiO2 passivation treatment was performed using plasma-enhanced chemical vapor deposition to form the lower substrate layer;

[0039] S6. A 3.16-μm thick SiO2 / TiO2 distributed Bragg mirror was prepared using an optical coating machine.

[0040] S7. After rapid annealing, the sapphire substrate layer 10 is thinned to 150μm by grinding and polishing.

[0041] S8. A frame-shaped resin mold is horizontally placed on the upper surface of the sapphire substrate 10 to form a groove structure with the sapphire substrate 10.

[0042] A certain amount of magnetic fluid is evenly dripped into the groove structure using a pipette until the groove is filled, forming a magnetic fluid film 70.

[0043] A PDMS sealing shell 80 is placed on top of the groove-shaped structure filled with magnetofluid, so that a cover is formed on the top of the groove to seal the magnetofluid inside the groove.

[0044] The above embodiments are only some preferred embodiments of this utility model and should not be used to limit the scope of protection of this utility model. Any non-substantial changes and substitutions made by those skilled in the art based on this utility model shall fall within the scope of protection claimed by this utility model.

Claims

1. A photoelectric magnetic field strength sensor for detecting morphological damage in ferromagnetic structures, comprising a chip, a magnetofluid film, and a substrate, characterized in that, The chip includes an LED light emitting module, a PD light receiving module, a P electrode, an N electrode, and a sapphire upper substrate layer disposed on the substrate; the LED light emitting module and the PD light receiving module are respectively connected to the corresponding P electrode and N electrode, the PD light receiving modules are distributed around the LED light emitting module, and the sapphire upper substrate layer is disposed on the upper surface of the LED light emitting module and the PD light receiving module; a magnetofluid film is disposed on the sapphire upper substrate layer, and the magnetofluid film is located above the PD light receiving module and the LED light emitting module.

2. The photoelectric magnetic field strength sensor for detecting morphological damage in ferromagnetic structures according to claim 1, characterized in that, It also includes a frame-shaped resin mold disposed on the sapphire substrate, wherein the inner frame of the frame-shaped resin mold and the upper surface of the sapphire substrate form a groove-shaped structure, and the magnetofluid film is filled in the groove-shaped structure.

3. The photoelectric magnetic field strength sensor for detecting morphological damage in ferromagnetic structures according to claim 1, characterized in that, It also includes a sealing shell, which covers the substrate. The LED light emitting module, PD light receiving module, sapphire upper substrate layer and frame-shaped resin mold are all located inside the sealing shell. The sealing shell encloses the magnetofluid membrane in a groove-shaped structure. The sealing shell is made of non-magnetic material.

4. The photoelectric magnetic field strength sensor for detecting morphological damage in ferromagnetic structures according to claim 3, characterized in that, The sealing shell is made of PDMS material.

5. The photoelectric magnetic field strength sensor for detecting morphological damage in ferromagnetic structures according to claim 1, characterized in that, It also includes a lower substrate layer disposed on the upper surface of the substrate.

6. The photoelectric magnetic field strength sensor for detecting morphological damage in ferromagnetic structures according to claim 5, characterized in that, An ITO current spreading layer is provided on the upper surface of the lower substrate layer.

7. The photoelectric magnetic field strength sensor for detecting morphological damage in ferromagnetic structures according to claim 5, characterized in that, The lower substrate layer is made of a light-transmitting material, and a Bragg reflector is provided on the lower surface of the lower substrate layer.

8. The photoelectric magnetic field strength sensor for detecting morphological damage in ferromagnetic structures according to claim 1, characterized in that, The substrate is provided with a power input interface and a light intensity signal output interface, and the P electrode and N electrode are electrically connected to the power input interface.

9. The photoelectric magnetic field strength sensor for detecting morphological damage in ferromagnetic structures according to claim 1, characterized in that, A mask pattern is provided between the PD light receiving module and the LED light emitting module.

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