Multichannel differential electrode array compatible with magnetometer and preparation method

Abstract

The invention discloses a multi-channel differential electrode array compatible with a magnetometer and a preparation method, and belongs to the technical field of biomedical engineering and atomic magnetometer application, the multi-channel differential electrode array comprises a flexible substrate layer, a packaging layer and a flexible lead interface, a plurality of electrode groups are clamped between the flexible substrate layer and the packaging layer, each electrode group comprises two electrode units, and the flexible lead interface is arranged between the flexible substrate layer and the packaging layer. The electrode units are connected with the flexible lead wire interface through interconnection wires, and the two electrode units on the electrode group form a differential channel to carry out differential acquisition on signals; each electrode unit is of a wave ring grid structure, each wave ring grid structure is composed of a plurality of basic wave ring units, every two adjacent basic wave ring units located on the same row have an intersection area to form a first closed-loop graph, and the basic wave ring units and the first closed-loop graphs have multidirectional flexibility. According to the invention, high-fidelity and low-noise synchronous acquisition of the myomagnetic signals in an ultralow magnetic field environment can be realized, the spatial resolution of the myoelectric signals can be effectively enhanced, common-mode interference can be inhibited, and the stability of signal acquisition and the wearing comfort can be improved.

Description

Technical Field

[0001] The present invention relates to the field of biomedical engineering and atomic magnetometer application technology, and in particular to a multi-channel differential electrode array compatible with a magnetometer. Background Art

[0002] The SERF atomic magnetometer (Spin-Exchange Relaxation-Free Magnetometer), with its high sensitivity and extremely low noise floor, is an ideal platform for magnetomyography (MMG) detection. By synchronizing measurements with surface electromyography (EMG), it can obtain high-resolution muscle activity information, thereby enhancing the quality and depth of functional imaging interpretation.

[0003] The technology for collecting and analyzing surface electromyography (EMG) signals is quite mature. Multi-channel electrode arrays based on flexible meshes, microstructured substrates, and modular, interconnected designs enable large-area coverage, high-density channel integration, and long-term stable wear even on complex curved skin surfaces. These technologies have been widely applied in fields such as sports science, rehabilitation assessment, and human-computer interaction.

[0004] Compared with the mature application of surface electromyography (EMG) technology, the acquisition and application of magnetomyography (MMG) signals are still in the exploratory stage. Although the electrode system currently in widespread use can record EMG signals with high quality, it has significant limitations in magnetic field compatibility. Specifically, traditional electrode materials are prone to magnetic disturbances, and the wiring layout may also introduce additional magnetic noise, making it difficult to adapt to the application requirements of ultra-low magnetic field environments such as SERF-type atomic magnetometers. The existing electrode system lacks structural optimization and magnetic suppression design specifically for MMG scenarios, making it difficult to achieve high-fidelity, low-noise synchronous acquisition of magnetomyography signals.

[0005] To address the problems of magnetic interference and common-mode interference caused by cable coupling on current electromyographic electrodes in magnetometer platforms such as SERF, the present invention proposes a multi-channel differential electrode array and its preparation method compatible with magnetometers, aiming to achieve high-fidelity joint acquisition in a low-magnetic background. Summary of the Invention

[0006] The purpose of the present invention is to provide a multi-channel differential electrode array compatible with magnetometers, aiming to overcome the limitations of existing electrodes in terms of magnetic interference, wire arrangement and flexible fit, and to achieve stable, high-fidelity synchronous acquisition of electromyographic and magnetomyoelectric signals in an ultra-low magnetic field environment.

[0007] To achieve the above objectives, the present invention provides the following solution: The present invention provides a multi-channel differential electrode array compatible with a magnetometer, comprising a flexible substrate layer, a packaging layer, and a flexible lead interface. A plurality of electrode groups are sandwiched between the flexible substrate layer and the packaging layer. The electrode group includes two electrode units, which are connected to the flexible lead interface via interconnecting wires. The two electrode units on the electrode group form a differential channel for differential signal acquisition.

[0008] The electrode unit is a wave ring grid structure, which is composed of several basic wave ring units. Two adjacent basic wave ring units in the same row have an intersection area to form a first closed loop figure. The basic wave ring units and the first closed loop figure have multi-directional flexibility.

[0009] Preferably, the plurality of electrode units are arranged in a rectangular array, and the two electrode units on the electrode group are located in the same column and arranged adjacent to each other.

[0010] Preferably, the basic wave ring unit and the first closed loop figure are one of rhombus, ellipse and hexagon.

[0011] Preferably, the electrode units and the interconnecting wires are both three-layer conductive structures, and the three-layer conductive structure is composed of a bottom carbon film, a middle silver film, and a top carbon film from bottom to top.

[0012] Preferably, the interconnecting wires are of a serpentine wave structure, forming a closed ring loop on a two-dimensional plane and having geometric balance and directional symmetry.

[0013] Preferably, the flexible substrate layer and the packaging layer are both made of polyimide film with a thickness not exceeding 5 μm, and the shapes of the flexible substrate layer and the packaging layer are consistent with the shapes of the plurality of electrode units.

[0014] Preferably, an adhesion layer and a bio-adhesive layer are sequentially provided outside the encapsulation layer, and both the adhesion layer and the bio-adhesive layer are made of silicone material.

[0015] Preferably, a release film is provided outside the bioconformable layer.

[0016] Preferably, the release film is made of polyethylene terephthalate and has a thickness of no more than 60 μm.

[0017] A method for preparing a multi-channel differential electrode array compatible with a magnetometer is also provided, comprising the following steps:

[0018] Step 1: Spin-coating a polyimide film on a glass substrate to form a flexible substrate layer, and patterning the flexible substrate layer to form a number of basic wave ring units;

[0019] Step 2: Using a magnetron sputtering process, a bottom carbon film, a middle silver film, and a top carbon film are sequentially deposited on the flexible substrate layer to form a three-layer conductive structure;

[0020] Step 3: Use dry etching or masking technology to remove the non-conductive areas on the three-layer conductive structure, leaving only the sensing area and the interconnection area, forming a plurality of electrode units and a plurality of interconnection wires;

[0021] Step 4: Spin-coat an encapsulation layer on the top carbon film and create windows in the encapsulation layer to expose the electrodes and interface areas.

[0022] Step 5: Spin-coat the adhesive layer and biocompatible layer on the encapsulation layer and overlay the release film;

[0023] Step 6: Peel the entire device off the glass substrate and connect it to the non-magnetic flexible lead interface to complete the preparation.

[0024] The present invention discloses the following technical effects:

[0025] (1) The multi-channel differential electrode array is composed of several basic wave ring units. In each wave ring grid, the current has two main routing paths. According to the right-hand screw rule, the two main routing paths generate magnetic fields with equal amplitude and opposite directions. The two magnetic fluxes highly overlap on the central axis and cancel each other out, thus forming a local "zero flux" band in the center of the grid. Residual magnetic fields only exist in the edge areas. Adjacent basic wave ring units in the same row form a first closed loop through the intersection area. Two auxiliary main routing paths are introduced in this area. The magnetic field direction generated by them is opposite to the original residual magnetic flux and the amplitude is equivalent, thereby further canceling the residual magnetic disturbance in the edge area and achieving secondary self-suppression of the local magnetic field. Several electrodes are grouped in pairs to form differential channels for differential acquisition, which can effectively enhance the spatial resolution of electromyographic signals and suppress common-mode interference. Therefore, the magnetic disturbance is low, and high-fidelity and low-noise synchronous acquisition of electromyographic signals can be achieved in ultra-low magnetic field environments.

[0026] (2) The multi-channel differential electrode array is composed of several basic wave ring units. Compared with traditional linear or solid electrodes, this structure has multi-dimensional stretching capabilities and better flexibility and ductility. This structure can effectively adapt to the complex curves of the skin and closely fit the surface of different parts of the human body. Especially under dynamic movement or epidermal deformation conditions, it can still maintain effective electrode contact and stable signal output. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0028] Figure 1 It is a structural schematic diagram of the present invention;

[0029] Figure 2 Schematic diagram of the structure of the three-layer conductive structure of the present invention;

[0030] Figure 3 Schematic diagram of the structure of the electrode unit in the present invention;

[0031] Figure 4 Schematic diagram of the arrangement of interconnecting wires in the present invention.

[0032] In the figure: 1. Flexible lead interface; 2. Electrode unit; 3. Interconnection wire; 4. Basic wave ring unit; 5. First closed-loop pattern; 6. Bottom carbon film; 7. Middle silver film; 8. Top carbon film; 9. Basic grid unit; 10. First main routing path; 11. Second main routing path; 12. Third main routing path; 13. Fourth main routing path; 14. Left-handed unit ring area; 15. Right-handed unit ring area; 16. Dual-rotation coupling area. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Reference Figures 1-4 The present invention provides a multi-channel differential electrode array compatible with a magnetometer, comprising: a flexible substrate layer, a packaging layer, and a flexible lead interface 1; a plurality of electrode groups are sandwiched between the flexible substrate layer and the packaging layer; the electrode group comprises two electrode units 2, and the electrode units 2 are connected to the flexible lead interface 1 via interconnecting wires 3; the two electrode units 2 on the electrode group form a differential channel for differential signal acquisition;

[0036] The electrode unit 2 is a wave ring grid structure, which is composed of several basic wave ring units 4. Two adjacent basic wave ring units 4 in the same row have an intersection area to form a first closed loop figure 5. The basic wave ring unit 4 and the first closed loop figure 5 have multi-directional flexibility and can be stretched in any direction. They can adapt to skin surface deformation and maintain conductive continuity.

[0037] Several electrode units 2 are grouped in pairs to form a differential channel for differential acquisition, which can effectively enhance the spatial resolution of the electromyographic signal and suppress common-mode interference.

[0038] Furthermore, the electrode units 2 are connected to a flexible lead interface 1 at the top edge of the array via a wave-shaped interconnecting conductor 3. This flexible lead interface 1 is used to connect to an external signal acquisition system. The electrode unit 2 array can also be directly connected to a non-magnetic flexible cable interface made of a non-ferromagnetic, flexible conductive material. This enables a low-magnetic interference data interface with magnetic field-sensitive equipment such as SERF atomic magnetometers, meeting the requirements of highly sensitive magnetic co-measurements.

[0039] Compared with traditional linear or solid electrodes, the basic wave ring unit of electrode unit 2 has the ability to stretch in multiple directions, has better flexibility and ductility, can effectively fit the complex surface of human skin, can adapt to the surface deformation caused by human movement, avoid local detachment or stress concentration, improve the stability of signal acquisition and wearing comfort, and achieve seamless cooperation with the SERF magnetometer through a multi-channel wiring layout without magnetic interference.

[0040] In this embodiment, the electrode unit 2 is composed of a plurality of basic wave ring units 4 of a diamond structure arranged periodically. Two adjacent basic wave ring units 4 in the same row form an intersection area in the edge area, thereby constructing a first closed-loop figure 5. Among them, the upper and lower vertices of each first closed-loop figure 5 intersect with the vertices of the adjacent basic wave ring units 4 in the upper and lower rows: the upper intersection point corresponds to the lower vertex of the basic wave ring unit 4 in the previous row, and the lower intersection point corresponds to the upper vertex of the basic wave ring unit 4 in the next row, forming a continuous grid structure to enhance structural stability and conductive continuity. Through the design of this structure, multiple groups of cyclically cross-arranged paths are formed, and each group of paths has four main routing paths with equal currents - namely, the first main routing path 10, the second main routing path 11, the third main routing path 12, and the fourth main routing path 13. The first main routing path 10, the second main routing path 11, the third main routing path 12, and the fourth main routing path 13 are all wavy in shape, and the demagnetization principle can be subdivided into two-stage coupling and flux cancellation mechanisms:

[0041] First, within the dual-rotation coupling region 16 at the center of each basic grid unit 9, the first main routing path 10 and the second main routing path 11 play a first-order magnetic field cancellation role. According to the right-hand screw rule, the first main routing path 10 generates a magnetic field perpendicular to the electrode unit and pointing outward on the grid centerline, while the second main routing path 11 generates a magnetic field of equal amplitude and opposite direction, perpendicular to the electrode unit and pointing inward. These two magnetic fields highly overlap and automatically cancel each other out on the centerline of the dual-rotation coupling region 16, forming a local zero flux band at the center of the grid. However, due to the difference in path distance, the further away from the centerline, the more obvious the residual perpendicular magnetic field component.

[0042] Secondly, in order to effectively eliminate the residual magnetic field in the above-mentioned edge area, a second-level magnetic field compensation mechanism is introduced: that is, the left-handed unit ring area 14 is provided with a third main routing path 12 with the same direction and strength as the second main routing path 11. The magnetic field generated by the third main routing path 12 is equal to and opposite to the residual magnetic field of the first main routing path 10 in the center of the area, thereby achieving secondary magnetic field cancellation at the midline of the left-handed unit ring area 14; similarly, the magnetic field direction of the fourth main routing path 13 in the right-handed unit ring area 15 is equal to and opposite to the residual magnetic field of the second main routing path 11 in the ring area, also forming secondary magnetic field cancellation on the midline of the right-handed unit ring area 15.

[0043] Overall, the multiple basic grid cells 9 of the entire electrode unit are repeated and staggered, allowing the magnetic field offsetting effects of the birotatory coupling region 16, the left-handed unit ring region 14, and the right-handed unit ring region 15 to be superimposed layer by layer. Ultimately, the magnetic field generated by these four main lines in space always maintains a precise local equilibrium state. Once attached to the surface of human skin, the electrode unit forms a fully self-balancing "zero flux" shielding layer across the entire area, effectively suppressing low-frequency and power-frequency magnetic field interference from the external environment, significantly reducing induced noise interference during electrode measurement, and improving the signal-to-noise ratio and measurement accuracy of electromyographic signal acquisition, achieving the goal of efficient demagnetization.

[0044] In some optional embodiments, a plurality of electrode units 2 are arranged in a rectangular array, and two electrode units 2 on an electrode group are located in the same column and are arranged adjacent to each other.

[0045] In this embodiment, 10 electrode units 2 are set, and the 10 electrode units 2 are divided into two rows. The 5 electrode units 2 on the first row are numbered 1 to 5 from left to right, and the 5 electrode units 2 on the second row are numbered 6 to 10 from left to right; they are grouped by columns, and each column contains two upper and lower electrode units 2, forming a total of 5 groups of differential channels, namely 1 and 6, 2 and 7, 3 and 8, 4 and 9, 5 and 10, and differential acquisition is performed on each of them, which effectively enhances the spatial resolution of the electromyographic signal and suppresses common-mode interference.

[0046] In some optional embodiments, the basic wave ring unit 4 and the first closed-loop graphic 5 are in the shape of a rhombus, an ellipse, or a hexagon.

[0047] In some optional embodiments, the electrode units 2 and the interconnecting wires 3 are both three-layer conductive structures, and the three-layer conductive structure is composed of a bottom carbon film 6, a middle silver film 7, and a top carbon film 8 from bottom to top.

[0048] The bottom carbon film 6 is about 50nm thick and is used to provide biocompatibility and electrochemical stability; the middle silver film 7 is about 300nm thick and serves as a high-conductivity channel to ensure low impedance of signal transmission; the top carbon film 8 is about 50nm thick; it forms a packaging structure for the middle silver conductor, which is used to isolate water vapor and electrolyte corrosion, while inhibiting metal ion migration, blocking the magnetic polarization path of the silver film, and reducing the magnetic coupling effect, that is, used for packaging protection and suppressing magnetization effect.

[0049] In some optional embodiments, the interconnection wire 3 has a serpentine wave structure, and the interconnection wire 3 forms a closed ring loop on a two-dimensional plane and has geometric balance and directional symmetry.

[0050] Interconnect conductor 3 features a serpentine-shaped structure, significantly extending its physical length and increasing its inductance, effectively reducing transient magnetic fields generated by rapidly changing currents. The serpentine structure also bends the current path, reducing the overall transient current rate and, consequently, the strength of the magnetic field surrounding the conductor. The differential arrangement of the electrodes, coupled with the serpentine-shaped structure of the interconnect, further counteracts common-mode magnetic interference.

[0051] The interconnecting wires 3 form a closed ring loop on a two-dimensional plane and have geometric balance and directional symmetry, so that the external magnetic flux changes passing through this area produce directional cancellation within the structural scale, thereby realizing the magnetic interference weakening function at the structural level.

[0052] Furthermore, the wave ring interconnection conductor 3 is designed using the 10W line width principle of PCB layout, where the width of the interconnection conductor 3 is 0.12mm, and the spacing between adjacent conductors is set to 1.2mm, that is, the spacing is 10 times the conductor width; this design has a clear electromagnetic compatibility (EMC) optimization purpose.

[0053] That is, there is sufficient spacing between the wires. Taking a given width of 0.12mm as an example, the spacing between interconnecting wires 3 is set to 1.2mm. This spacing significantly reduces the electromagnetic coupling between adjacent interconnecting wires 3, effectively suppressing electromagnetic interference (EMI) and crosstalk caused by high-frequency signals or transient currents. The magnetic field coupling between the wires rapidly decays as the distance increases (the magnetic field strength decays exponentially with the spacing), forming a low magnetic field intensity area and improving the overall electromagnetic environment. Through this layout (the wire spacing is 10 times the wire width), the magnetic field of adjacent interconnecting wires 3 is rapidly attenuated, significantly improving the electromagnetic compatibility of the entire circuit, achieving the purpose of effective demagnetization and reducing electromagnetic interference. It is particularly suitable for high-sensitivity biosignal acquisition systems such as electromyography.

[0054] In some optional embodiments, the flexible substrate layer and the packaging layer are both made of polyimide film with a thickness not exceeding 5 μm, and the shapes of the flexible substrate layer and the packaging layer are consistent with the shapes of the electrode units 2 .

[0055] Ensure that an electro-magnetic decoupling path is formed between the conductor grids when the magnetic field is disturbed.

[0056] In some optional embodiments, an adhesion layer and a bio-adhesive layer are sequentially provided outside the encapsulation layer, and both the adhesion layer and the bio-adhesive layer are made of silicone material.

[0057] The adhesion layer uses Bluestar 4642 silicone with a thickness of 80μm; the bio-bonding layer uses Ecoflex 0030 silicone with a spin-coated thickness of approximately 8μm. It is used to improve wearing comfort and interface stability, and achieve large-area bonding and comfort with complex skin surfaces. It can not only collect multi-channel electromyographic signals with high fidelity, but also provide a stable, low-interference reference substrate for myomagnetic measurement.

[0058] In some optional embodiments, a release film is disposed outside the bioconformable layer.

[0059] In some optional embodiments, the release film is made of polyethylene terephthalate (PET) and has a thickness of no more than 60 μm.

[0060] The thickness is 50μm, which is used for the overall peeling and transfer of the device after preparation to ensure structural integrity and magnetic field consistency.

[0061] A method for preparing a multi-channel differential electrode array compatible with a magnetometer is also provided, comprising the following steps:

[0062] Step 1: Spin-coating a thin film of polyimide on a glass substrate to form a flexible substrate layer, and patterning the flexible substrate layer to form a number of basic wave ring units;

[0063] Step 2: Using a magnetron sputtering process, a bottom carbon film 6, a middle silver film 7 and a top carbon film 8 are sequentially deposited on the flexible substrate layer to form a three-layer conductive structure;

[0064] Step 3: Use dry etching or masking technology to remove the non-conductive areas on the three-layer conductive structure, leaving only the sensing area and the interconnection area, to form a plurality of electrode units 2 and a plurality of interconnection wires 3;

[0065] Step 4: Spin-coating an encapsulation layer on the top carbon film 8 and opening windows on the encapsulation layer to expose the electrodes and interface areas;

[0066] Step 5: Spin-coat the adhesive layer and biocompatible layer on the encapsulation layer and overlay the release film;

[0067] Step 6: Peel the entire device off the glass substrate and connect it to the non-magnetic flexible lead interface 1 to complete the preparation.

[0068] Specifically:

[0069] Spin-coating a polyimide film on a glass substrate to form an initial flexible substrate, and patterning a basic wave ring unit pattern by laser etching or photolithography;

[0070] A magnetron sputtering process is used to sequentially deposit a bottom carbon film 6, a middle silver film 7, and a top carbon film 8 to form a three-layer conductive functional film;

[0071] By using masking or dry etching technology, the conductive patterns of the electrode sensing area and the interconnection channel area of ​​the three-layer conductive functional film are retained, and the metal in the remaining areas is removed;

[0072] Spin-coat the PI encapsulation layer and partially open windows to expose the electrodes and wiring connection areas;

[0073] A Bluestar 4642 adhesion layer (approximately 80 microns thick) and an Ecoflex 0030 bio-conformable layer (approximately 8 microns thick) were spin-coated on the encapsulation layer in sequence;

[0074] Finally, a PET release film (about 50 microns thick) is attached to the outermost layer of the device for overall device peeling and protection.

[0075] The device is released from the glass substrate as a whole through thermal responsive peeling, and connected to a non-magnetic flexible wiring system to complete the packaging of the finished electrode array.

[0076] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, 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 therefore cannot be understood as a limitation on the present invention.

[0077] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A multi-channel differential electrode array compatible with a magnetometer, characterized in that: It comprises a flexible substrate layer, a packaging layer and a flexible lead interface (1), wherein a plurality of electrode groups are sandwiched between the flexible substrate layer and the packaging layer, wherein the electrode group comprises two electrode units (2), and the electrode units (2) are connected to the flexible lead interface (1) via interconnecting wires (3), and the two electrode units (2) on the electrode group form a differential channel for differential signal acquisition; The electrode unit (2) is a wave ring grid structure, which is composed of a plurality of basic wave ring units (4). Two adjacent basic wave ring units (4) located in the same row have an intersection area to form a first closed loop pattern (5). The basic wave ring units (4) and the first closed loop pattern (5) have multi-directional flexibility.

2. The multi-channel differential electrode array compatible with a magnetometer according to claim 1, characterized in that: The plurality of electrode units (2) are arranged in a rectangular array, and two electrode units (2) on the electrode group are located in the same column and arranged adjacent to each other.

3. The multi-channel differential electrode array compatible with a magnetometer according to claim 1, characterized in that: The basic wave ring unit (4) and the first closed-loop figure (5) are in the shape of a rhombus, an ellipse, or a hexagon.

4. The multi-channel differential electrode array compatible with a magnetometer according to claim 1, characterized in that: The electrode unit (2) and the interconnecting wire (3) both have a three-layer conductive structure, and the three-layer conductive structure comprises, from bottom to top, a bottom carbon film (6), a middle silver film (7), and a top carbon film (8).

5. The multi-channel differential electrode array compatible with a magnetometer according to claim 1, characterized in that: The interconnecting wire (3) is a serpentine wave structure, and the interconnecting wire (3) forms a closed annular loop on a two-dimensional plane and has geometric balance and directional symmetry.

6. The multi-channel differential electrode array compatible with a magnetometer according to claim 1, characterized in that: The flexible substrate layer and the packaging layer are both made of polyimide film with a thickness not exceeding 5 μm. The shapes of the flexible substrate layer and the packaging layer are consistent with the shapes of the plurality of electrode units (2).

7. The multi-channel differential electrode array compatible with a magnetometer according to claim 1, characterized in that: An adhesion layer and a bio-adhesive layer are sequentially arranged outside the packaging layer, and both the adhesion layer and the bio-adhesive layer are made of silicone material.

8. The multi-channel differential electrode array compatible with a magnetometer according to claim 1, characterized in that: A release film is arranged outside the bio-adhesive layer.

9. The multi-channel differential electrode array compatible with a magnetometer according to claim 8, characterized in that: The release film is made of polyethylene terephthalate and has a thickness not exceeding 60 μm.

10. A method for preparing a multi-channel differential electrode array compatible with a magnetometer, according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: Spin-coating a polyimide film on a glass substrate to form a flexible substrate layer, and patterning the flexible substrate layer to form a number of basic wave ring units; Step 2: using a magnetron sputtering process to sequentially deposit a bottom carbon film (6), a middle silver film (7) and a top carbon film (8) on the flexible substrate layer to form a three-layer conductive structure; Step 3: using dry etching or masking technology to remove the non-conductive areas on the three-layer conductive structure, leaving only the sensing area and the interconnection area, to form a plurality of electrode units (2) and a plurality of interconnection wires (3); Step 4: Spin-coating an encapsulation layer on the top carbon film (8), and opening windows on the encapsulation layer to expose the electrodes and interface areas; Step 5: Spin-coat the adhesive layer and biocompatible layer on the encapsulation layer and overlay the release film; Step 6: Peel the entire device off the glass substrate and connect it to the non-magnetic flexible lead interface (1) to complete the preparation.

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