Flexible magnetic tactile sensor capable of sensing multiple parameters and preparation method and detection method

Abstract

This invention discloses a flexible magnetic tactile sensor capable of sensing multiple parameters, along with its fabrication and detection methods. The sensor comprises a flexible contact layer, an elastic substrate layer, and a magnetic sensor layer. The flexible contact layer is disposed on top of the elastic substrate layer and includes a magnetic film. The magnetic film comprises two or more sub-regions containing hard magnetic particles and sub-regions containing both hard and soft magnetic particles, which are alternately distributed. The magnetic sensor layer is disposed below the elastic substrate layer or embedded within it, and includes multiple magnetic sensors arranged in a one-to-one correspondence with the multiple sub-regions of the magnetic film. By selecting both hard and soft magnetic particles and organic polymers to prepare a composite particle magnetoelastic body, force / thermal information decoupling is achieved from both array layout design and signal processing perspectives. This not only enables highly sensitive measurement of force information but also allows for the determination of temperature information, demonstrating potential applications in multiple fields.

Description

Technical Field

[0001] This invention relates to the field of flexible tactile sensor technology, and specifically discloses a flexible magnetic tactile sensor capable of sensing multiple parameters, as well as its preparation and detection methods. Background Technology

[0002] Human skin contains numerous receptors that provide rich tactile feedback, enabling humans to not only dynamically adjust finger posture and contact force for precise object recognition, grasping, and manipulation, but also analyze surface texture and material characteristics. Tactile sensors, with tactile perception capabilities similar to human skin, can provide robots with sliding feedback, improving motion accuracy and sensitivity, and enhancing the interactivity, adaptability, and intelligence of robot component design and performance control. Furthermore, they hold broad application prospects in advanced medicine, virtual reality, and other fields.

[0003] The core of flexible tactile sensors is converting mechanical interactions into electrical signals that can be interpreted by digital controllers. Currently, researchers have developed a series of flexible tactile sensors based on measurement principles such as piezoresistive, piezoresistive, piezoelectric, and triboelectric sensing, utilizing flexible electronics technology, metal nanomaterials, two-dimensional conductive materials, and hydrogels. These sensors have demonstrated excellent performance in terms of high-precision sensing and rapid response. However, with further increases in the performance requirements of sensors, the internal complexity of sensor devices continues to rise, posing challenges to ensuring device stability.

[0004] Magnetotactic sensors typically consist of a magnetic source that generates a magnetic field signal and a magnetic sensor that detects the magnetic field signal. They offer advantages such as high sensitivity, low hysteresis, low power consumption, and ease of achieving three-dimensional detection and remote measurement. Furthermore, the magnetic field can penetrate biological bodies and water without loss of strength, providing wireless penetration. Existing flexible magnetic sensors utilize flexible magnetic materials and employ microstructure design and magnetization strategies to achieve highly sensitive force detection and three-dimensional force decoupling. However, research on measuring other parameters such as temperature is lacking, which limits the application of flexible magnetic tactile sensors in fields such as bionic robotics. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a flexible magnetic tactile sensor that can not only realize high-sensitivity measurement of force information, but also solve for temperature information and sense multiple parameters.

[0006] The present invention further provides a method for preparing the above-mentioned flexible magnetic tactile sensor capable of sensing multiple parameters.

[0007] The present invention further provides a detection method for detecting force information and temperature information using the above-mentioned flexible magnetic tactile sensor capable of sensing multiple parameters.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] A flexible magnetic tactile sensor capable of sensing multiple parameters includes a flexible contact layer, an elastic substrate layer, and a magnetic sensor layer. The flexible contact layer is disposed on the upper side of the elastic substrate layer and includes a magnetic film. The magnetic film includes two or more sub-regions containing hard magnetic particles and two or more sub-regions containing soft and hard magnetic particles, which are alternately distributed. The magnetic sensor layer is disposed on the lower side of the elastic substrate layer or embedded inside the elastic substrate layer and includes multiple magnetic sensors, which are arranged in a one-to-one correspondence with the multiple sub-regions of the magnetic film.

[0010] As a further preferred option of the above technical solution:

[0011] The hard magnetic particles are neodymium iron boron particles, which have a high magnetic energy product and good thermal stability, as well as good compatibility with various polymer matrices (such as resins, rubbers, etc.).

[0012] And / or, the soft magnetic particles in the soft and hard magnetic particles are iron oxide particles, which have excellent temperature sensitivity in the DC magnetization response generated under static magnetic field excitation, and the hard magnetic particles in the soft and hard magnetic particles are also neodymium iron boron particles.

[0013] And / or, the elastic substrate layer is made of a flexible and stretchable organic polymer material (such as Ecoflex silicone, a platinum-catalyzed silicone produced by Smooth-On in the United States, which has the characteristics of being ultra-soft, highly elastic and low in viscosity).

[0014] And / or, the magnetic sensor employs a Hall element (e.g., the MLX90393, a high-performance triaxial Hall effect sensor developed by Melexis, capable of measuring the strength and direction of a magnetic field). The Hall element includes the Hall element body and a flexible printed circuit board (fPCB), which allows for better fit with the magnetoelastic body and enhances the conformal capability of the flexible magnetic tactile sensor, enabling it to be better mounted on non-planar surfaces such as mechanical fingertips. Preferably, a microcontroller is connected to the Hall element to detect its output signal. The Hall element output signal is amplified and filtered by a preprocessing circuit before being input into the computer via a data card.

[0015] As a further preferred embodiment of the above technical solution: the sub-region containing hard magnetic particles and the sub-region containing soft and hard magnetic particles have the same cross-sectional shape (e.g., both are square or circular) and the same size.

[0016] As a further preferred embodiment of the above technical solution: the main body of the magnetic sensor is parallel to the magnetic film and arranged at the center of each sub-region.

[0017] A method for fabricating the above-mentioned flexible magnetic tactile sensor capable of sensing multiple parameters, wherein the fabrication process of the magnetic film is as follows:

[0018] First, a hard magnetic particle magnetoelastic with a micropillar array structure is prepared: an uncured organic polymer solution mixed with hard magnetic particles is poured into a micropillar array mold, and after vacuum defoaming treatment, it is placed in a uniform magnetic field until it is cured and formed. After magnetizing the cured elastomer along the direction of the cylindrical hole, it is demolded to obtain a hard magnetic particle magnetoelastic with hard magnetic particles arranged in an orderly manner in a specific direction.

[0019] Then, an organic polymer solution containing soft magnetic particles is filled into a magnetic elastomer containing hard magnetic particles, and after curing, the sub-region containing both soft and hard magnetic particles is obtained; an organic polymer solution without magnetic particles is used to fill a magnetic elastomer containing hard magnetic particles, and after curing, the sub-region containing hard magnetic particles is obtained.

[0020] Finally, the prepared sub-regions containing hard magnetic particles and sub-regions containing soft and hard magnetic particles are arrayed to obtain a magnetic film.

[0021] As a further preferred embodiment of the above technical solution, the specific steps include:

[0022] a) Micropillar array molds are prepared by 3D printing, which makes it easy to control the diameter, height and array distribution of the micropillar structure. The micropillar array molds are cleaned with ethanol and the surface is air-dried at room temperature.

[0023] b) Add neodymium iron boron particles to Ecoflex agent A and stir thoroughly, then add Ecoflex agent B and stir thoroughly. Pour the mixture into the micro-pillar array mold, and after defoaming treatment in a vacuum chamber (e.g., vacuum chamber with a vacuum degree of -0.1 MPa for 10 minutes), place it in a structured magnetic field (e.g., static magnetic field with a magnetic field strength of 0.1 Tesla) and let it stand at room temperature to wait for curing.

[0024] c) Demold the cured Ecoflex to obtain an elastomer containing NdFeB particles. Place the elastomer containing NdFeB particles into a magnetizer for magnetization to obtain a hard magnetic particle magnetoelastic body with magnetic properties.

[0025] d) The hard magnetic particle magnetoelastic body prepared in step c) is filled with Ecoflex without magnetic particles, and after defoaming and curing, a sub-region containing hard magnetic particles is obtained.

[0026] e) Add the iron oxide particles to Ecoflex A agent and stir thoroughly. Then add Ecoflex B agent and stir thoroughly. Fill the hard magnetic particle magnetoelastic body prepared in step c) and after defoaming and curing, a sub-region containing both soft and hard magnetic particles is obtained.

[0027] f) Assemble the sub-region containing hard magnetic particles prepared in step d) and the sub-region containing soft and hard magnetic particles prepared in step e) to form a magnetic film. Place the corresponding Hall element at the center of each sub-region of the magnetic film and use Ecoflex, which does not contain magnetic particles, to make an elastic substrate layer to complete the encapsulation.

[0028] As a further preferred embodiment of the above technical solution: the volume ratio of monomer Ecoflex A to crosslinking agent Ecoflex B is 1:1. The cured Ecoflex silicone is less likely to stick to the micropillar array mold, which can reduce the damage to the elastomer during the demolding process.

[0029] As a further preferred embodiment of the above technical solution: the mass ratio of hard magnetic particles to uncured organic polymer solution is 1:1 to 3:7.

[0030] As a further preferred embodiment of the above technical solution, the uniform magnetic field is a static magnetic field.

[0031] A detection method for detecting force / temperature information using the aforementioned flexible magnetic tactile sensor capable of sensing multiple parameters.

[0032] The magnetic field strength is obtained using the aforementioned flexible magnetic tactile sensor capable of sensing multiple parameters. The force and temperature information are calculated using the following models:

[0033] The magnetic field strength B detected by the magnetic sensor is:

[0034]

[0035] In the above formula, n and d are the carrier concentration and thickness of the Hall material, respectively, e is the electron charge, and I S The current flowing through the Hall material is I when the operating current is... S When fixed, Hall voltage V H It is positively correlated with the change in magnetic field strength B.

[0036] Based on the Hall element output voltage V corresponding to the sub-region containing hard magnetic particles h The magnetic field strength B obtained by solving h It only includes the term representing the change in magnetic field strength caused by external forces:

[0037] B h =f H ·H h+f σ ·σ

[0038] In the above formula, f H f σ The effective field calculation functions for the magnetization field and stress field of hard magnetic particles are H, respectively. h σ is the magnetization field of the hard magnetic particles, and σ is the strain generated by the magnetoelastic body under the action of external force. Based on the previously calibrated relationship between external force and strain, as well as the intensity of the magnetization field of the hard magnetic particles, a regression model of the contact force magnitude is constructed, which can solve for the force magnitude of the flexible magnetic tactile sensor that can sense multiple parameters.

[0039] Based on the Hall element output voltage V corresponding to the sub-region containing soft and hard magnetic particles S The obtained magnetic field strength Bs only includes the change in magnetic field strength caused by the external force:

[0040] B s =f H ·H h +f σ ·σ+f T ·T

[0041] In the above formula, f T Let T be the effective field calculation function for the temperature field, and T be the temperature value. Based on the finite difference principle, the following formula is used:

[0042] B s -B h =f T ·T

[0043] Based on the previously calibrated relationship between temperature and magnetic field changes, a regression model of the contact temperature magnitude is constructed, which can be used to obtain the temperature information of the flexible magnetic tactile sensor that can sense multiple parameters.

[0044] Compared with the prior art, the advantages of the present invention are as follows:

[0045] The flexible magnetic tactile sensor disclosed in this invention possesses excellent stretchability. By adjusting process parameters, the overall thickness of the sensor can be controlled, allowing it to maintain good conformality with the mounting surface. The elastic base layer serves as the application surface of the flexible magnetic tactile sensor. If a separate installation is adopted, the flexible contact layer and the magnetic sensor can be separated, eliminating the need for cable connections or direct contact, thus ensuring the stability of the magnetic sensor and enabling its application in underwater and other scenarios. This invention uses both hard and soft magnetic particles with organic polymers to prepare a composite particle magnetoelastic body. It achieves force / thermal information decoupling from both array layout design and signal processing levels, enabling not only high-sensitivity measurement of force information but also the determination of temperature information. This has significant application potential in multiple fields such as bionic robotics and advanced medicine.

[0046] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0047] Figure 1 This is a three-dimensional structural diagram of the flexible magnetic tactile sensor capable of sensing multiple parameters according to the present invention.

[0048] Figure 2 This is a schematic diagram of the preparation method of the flexible magnetic tactile sensor capable of sensing multiple parameters according to the present invention.

[0049] Figure 3 This is a graph showing the results of actual pressure measurement according to the present invention. The applied pressure is a positive pressure perpendicular to the surface of the magnetic film.

[0050] Figure 4 This is a graph showing the actual temperature measurement results of this invention.

[0051] The labels in the diagram represent:

[0052] 1. Micropillar array mold; 2. Hard magnetic particle magnetoelastic; 3. Magnetic poles for generating structural magnetic fields; 4. Elastomer without magnetic particles; 5. Soft magnetic particle magnetoelastic; 6. Elastic base layer; 7. Hall element; 8. Square vessel; 9. Sub-region containing hard magnetic particles; 10. Sub-region containing soft and hard magnetic particles. Detailed Implementation

[0053] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0054] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0055] In this invention, unless otherwise explicitly specified and limited, the terms "assembly," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0056] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0057] like Figure 1 and Figure 2 As shown in the figure, a method for fabricating a flexible magnetic tactile sensor capable of sensing multiple parameters in this embodiment includes the following steps:

[0058] a) Design and fabricate a micropillar array mold 1 with a square base and a side length of 15 mm using 3D printing. The micropillars on the micropillar array mold 1 have a diameter of 200 micrometers. A photopolymer 3D printer is used, and photosensitive resin is selected. After the mold is printed, the surface is cleaned with ethanol and then exposed to ultraviolet light for 30 minutes to obtain the micropillar array mold 1. Then, it is placed in a square mold with an inner side length of 15 mm.

[0059] b) Hard magnetic particle magnetoelastic body 2 was prepared according to the material ratio: 25wt% Ecoflex 00-30A agent, 25wt% Ecoflex 00-30B agent, and 50wt% neodymium iron boron particles, wherein the diameter of the neodymium iron boron particles was 5 micrometers. First, Ecoflex 00-30A agent and neodymium iron boron particles were mixed by magnetic stirring at 2000 rpm for 3 minutes. Then, Ecoflex 00-30B agent was added and mixed at the same speed for 3 minutes. Then, the mixture was slowly poured into a square mold containing the micro-pillar array mold 1 and transferred to a vacuum chamber with a vacuum degree of -0.1 MPa. After vacuuming for 10 minutes to complete defoaming, it was transferred to a structural magnetic field and allowed to stand for 6 hours to cure. Then, it was demolded to obtain the cured hard magnetic particle magnetoelastic body 2.

[0060] c) Prepare an elastomer without magnetic particles according to the material ratio: 45wt% Ecoflex 00-30A agent, 45wt% Ecoflex 00-30B agent, and 10wt% 5 viscosity dimethyl silicone oil. After mixing the materials, stir magnetically at 2000 rpm for 3 minutes. Slowly pour the mixture into a square mold containing the cured hard magnetic particle magnetoelastic 2 and place it in a vacuum chamber for defoaming for 10 minutes. Let it stand and cure for 6 hours, and then demold to obtain the sub-region 9 containing hard magnetic particles.

[0061] d) Prepare soft magnetic particle magnetoelastic body 5 according to the material ratio: 30wt% Ecoflex 00-30A agent, 30wt% Ecoflex 00-30B agent, 6.7wt% 5 viscosity dimethyl silicone oil, and 33.3wt% iron oxide particles, wherein the diameter of the iron oxide particles is 100 nanometers. After mixing the materials, stir magnetically at 2000 rpm for 3 minutes. Then, slowly pour the mixture into a square mold containing the cured hard magnetic particle magnetoelastic body 2 and place it in a vacuum chamber to defoam for 10 minutes. After standing and curing for 6 hours, demold to obtain sub-region 10 containing soft and hard magnetic particles.

[0062] e) Place two sub-regions 9 containing hard magnetic particles and two sub-regions 10 containing soft and hard magnetic particles into a square container 8 with a side length of 35 mm, in a manner that the sub-regions of the same type are not adjacent. Slowly pour a mixed solution with the same material ratio as the elastomer 4 without magnetic particles into the square container 8. The solution covers the soft magnetic particle magnetoelastic 5 and the hard magnetic particle magnetoelastic 2 by 5 mm. Then, place the square container 8 in a vacuum chamber to defoam and let it stand for 6 hours to cure.

[0063] f) Apply room temperature adhesive ELASTOSIL E43, a high-performance silicone material brand produced by Wacker Chemie AG, Germany, to the surface of Hall element 7. This adhesive is widely used in industrial, construction, automotive, medical, and consumer products fields. Attach Hall element 7 to the center of the corresponding magnetic film sub-region, i.e., the position where the Hall element 7 outputs the largest voltage signal. Then, slowly pour in a mixed solution with the same material ratio as the non-magnetic particle elastomer 4 to fill the gaps between the soft magnetic particle magnetoelastic 5, the hard magnetic particle magnetoelastic 2, and the PCB board. After curing, an elastic base layer 6 is obtained. After demolding, the sensor fabrication is complete. The resulting flexible magnetic tactile sensor structure capable of sensing multiple parameters is shown below. Figure 1 As shown.

[0064] Preferably, the Hall element 7 is a linear Hall element, with the input being the magnetic induction intensity and the output being the voltage proportional to the input.

[0065] Preferably, the organic polymer used is Ecoflex silicone, which has a low elastic modulus and large deformation characteristics, which can improve the force sensitivity of the sensor and achieve excellent sensing of minute forces.

[0066] Preferably, the PCB board can be an fPCB board manufactured based on flexible electronic printing technology, which can not only better fit with the magnetic elastomer (including soft magnetic particle magnetic elastomer 5 and hard magnetic particle magnetic elastomer 2), but also improve the conformal capability of the flexible magnetic tactile sensor, so that the flexible magnetic tactile sensor can be better installed on non-planar surfaces such as mechanical fingertips.

[0067] Figure 3 The relationship between the Hall element signal and the load during the actual pressure test of the present invention is shown. The signal intensity of the superimposed Hall element output signal corresponding to sub-region 9 containing hard magnetic particles and the Hall element output signal corresponding to sub-region 10 containing soft and hard magnetic particles is used as input to construct a regression model of the contact force magnitude, so as to solve for the magnitude of the contact force.

[0068] Figure 4 The relationship between the Hall element signal and the load during the actual temperature test of the present invention is shown. By differentiating the Hall element output signal corresponding to sub-region 9 containing hard magnetic particles and the Hall element output signal corresponding to sub-region 10 containing soft and hard magnetic particles, a regression model of the contact temperature magnitude is constructed based on the relationship between temperature and differential signal intensity to obtain the contact temperature magnitude.

[0069] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. A flexible magnetic haptic sensor capable of sensing multiple parameters, characterized in that: The system includes a flexible contact layer, an elastic substrate layer (6), and a magnetic sensor layer. The flexible contact layer is disposed on the upper side of the elastic substrate layer (6). The flexible contact layer includes a magnetic film. The magnetic film includes two or more sub-regions (9) containing hard magnetic particles and two or more sub-regions (10) containing soft and hard magnetic particles. The sub-regions (9) containing hard magnetic particles and the sub-regions (10) containing soft and hard magnetic particles are alternately distributed. The magnetic sensor layer is disposed on the lower side of the elastic substrate layer (6) or embedded inside the elastic substrate layer (6). The magnetic sensor layer includes multiple magnetic sensors. The multiple magnetic sensors are arranged one-to-one with the multiple sub-regions of the magnetic film. The magnetic field strength is obtained using the aforementioned magnetic sensor, and the force and temperature information are calculated using the following models: Magnetic sensor detected magnetic field strength B Is: In the above formula n and d These represent the carrier concentration and thickness of the Hall material, respectively. e For electron charge, I S The current flowing through the Hall material, when the operating current... I S When fixed, Hall voltage V H With magnetic field strength B The changes are positively correlated; The output voltage of the Hall element (7) corresponding to the sub-area (9) containing hard magnetic particles V h The magnetic field strength obtained by solving B h Only the term of the change in the magnetic field strength caused by the external force In the above formula f H , f σ These are the effective field calculation functions for the magnetization field and stress field of hard magnetic particles, respectively. H h For the magnetization field of hard magnetic particles, σ The strain generated by the magnetoelastic body under external force is determined by constructing a regression model of the contact force based on the previously calibrated relationship between external force and strain, as well as the magnetization field strength of hard magnetic particles. This model can be used to solve for the force magnitude of the flexible magnetic tactile sensor that can sense multiple parameters. The output voltage of the Hall element (7) corresponding to the sub-area (10) containing soft and hard magnetic particles V S The magnetic field strength obtained by solving Bs Only the term of the change in the magnetic field strength caused by the external force In the above formula f T is the effective field calculation function for the temperature field, T is the temperature value, according to the differential principle, by the following formula: Based on the previously calibrated relationship between temperature and magnetic field changes, a regression model of the contact temperature magnitude is constructed, which can be used to obtain the temperature information of the flexible magnetic tactile sensor that can sense multiple parameters.

2. The flexible magnetic tactile sensor capable of sensing multiple parameters according to claim 1, characterized in that: The hard magnetic particles are neodymium iron boron particles; And / or, the soft magnetic particles in the soft and hard magnetic particles are iron oxide particles, and the hard magnetic particles are neodymium iron boron particles. And / or, the elastic substrate (6) is made of a flexible and stretchable organic polymer material; And / or, the magnetic sensor employs a Hall element (7), which includes a Hall element body and a flexible printed circuit board.

3. The flexible magneto-tactile sensor of perceptible multiple-variables according to claim 1, characterized in that: The sub-region (9) containing hard magnetic particles and the sub-region (10) containing soft and hard magnetic particles have the same cross-sectional shape and the same size.

4. The flexible magneto-tactile sensor of perceptible multiple-variables according to claim 3, characterized in that: The main body of the magnetic sensor is parallel to the magnetic film and is arranged at the center of each sub-region.

5. A method of manufacturing the flexible magneto-tactile sensor of perceivable multiple variables according to any one of claims 1 to 4, characterized in that: The preparation process of the magnetic film is as follows: First, a hard magnetic particle magnetoelastic body with a micro-pillar array structure (2) is prepared: an uncured organic polymer solution mixed with hard magnetic particles is poured into a micro-pillar array mold (1), and after vacuum defoaming treatment, it is placed in a uniform magnetic field until it is cured and formed. After magnetizing the cured elastomer along the direction of the cylindrical hole, it is demolded to obtain a hard magnetic particle magnetoelastic body (2) with hard magnetic particles arranged in an orderly manner in a specific direction. Then, the organic polymer solution containing soft magnetic particles is filled into the hard magnetic particle magnetoelastic body (2), and after curing, the sub-region containing both soft and hard magnetic particles (10) is obtained; the hard magnetic particle magnetoelastic body (2) is filled with an organic polymer solution without magnetic particles, and after curing, the sub-region containing hard magnetic particles (9) is obtained. Finally, the prepared sub-regions (9) containing hard magnetic particles and (10) containing soft and hard magnetic particles are arranged in an array to obtain a magnetic film.

6. The method of claim 5, wherein the method further comprises: Specifically, the following steps are included: a) A micropillar array mold (1) was prepared by 3D printing, the micropillar array mold (1) was cleaned with ethanol and the surface was air-dried at room temperature; b) Add neodymium iron boron particles to Ecoflex A agent and stir thoroughly. Then add Ecoflex B agent and stir thoroughly. Pour into the micro-pillar array mold (1). After defoaming treatment in a vacuum box, place in a structured magnetic field and let stand at room temperature to wait for curing. c) Demold the cured Ecoflex to obtain an elastomer containing neodymium iron boron particles. Place the elastomer containing neodymium iron boron particles into a magnetizer for magnetization to obtain a magnetic hard magnetic particle magnetoelastic body (2). d) The hard magnetic particle magnetoelastic body (2) prepared in step c) is filled with Ecoflex without magnetic particles, and after defoaming and curing, the sub-region containing hard magnetic particles (9) is obtained. e) Add the iron oxide particles to Ecoflex A agent and stir thoroughly, then add Ecoflex B agent and stir thoroughly before filling the hard magnetic particle magnetoelastic body (2) prepared in step c). After defoaming and curing, the sub-region (10) containing both soft and hard magnetic particles is obtained. f) Assemble the sub-region (9) containing hard magnetic particles prepared in step d) and the sub-region (10) containing soft and hard magnetic particles prepared in step e) to form a magnetic film. Place the corresponding Hall element (7) at the center of each sub-region of the magnetic film and use Ecoflex, which does not contain magnetic particles, to make an elastic substrate layer (6) to complete the encapsulation.

7. The method of claim 6, wherein the method further comprises: The volume ratio of monomer Ecoflex A to crosslinking agent Ecoflex B is 1:

1.

8. The method of claim 5, wherein the method further comprises: The mass ratio of hard magnetic particles to uncured organic polymer solutions is 1:1 to 3:

7.

9. The method of claim 5, wherein the method further comprises: The uniform magnetic field is a static magnetic field.

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