Flexible multi-dimensional force sensor based on centripetal gradient magnetic field and preparation method thereof

Abstract

The application discloses a flexible multi-dimensional force sensor based on a centripetal gradient magnetic field design and a preparation method thereof, and belongs to the field of electronic devices. The flexible multi-dimensional force sensor comprises, from top to bottom, a protective layer, a magnetic film layer, a buffer layer and a transmission layer. The protective layer comprises a flexible base material with force-sensitive characteristics. The magnetic film layer is provided with a cross-shaped groove on the bottom surface, and the edges of the groove are arc-shaped, so that a magnetic field with a gradient magnetic flux can be formed. The buffer layer comprises a strain material with a stepped shape. The transmission layer comprises an electromagnetic effect chip with three-axis magnetic field sensing capability and a readout circuit thereof. Compared with the prior art, the sensor of the application realizes natural decoupling from the magnetic field design, and has decoupling capability on three axes. The gradient design of the application enables the sensor to have different response slopes at different stress stages when subjected to stress, greatly improves the force measurement range of the device, and the sensing sensitivity and range on the three axes are the same.

Description

Technical Field

[0001] This invention relates to the field of electronic devices, specifically to a flexible multidimensional force sensor based on a centripetal gradient magnetic field design and its fabrication method. Background Technology

[0002] In today's era of rapid development in artificial intelligence and robotics, a wealth of electronic sensors, such as vision and hearing devices, are driving the development of bionic humanoid robots and natural interaction robots. However, tactile devices, which are particularly important in natural interaction, especially sensors for multi-dimensional forces in robots, still face challenges such as rigid sensors being difficult to adapt to bionic flexible skin, the difficulty in decoupling multi-dimensional force signals under a single sensor, the poor force sensing performance of flexible tactile sensors, and the difficulty in large-scale manufacturing. As a result, robots cannot achieve rich tactile interactions similar to those of humans in actual use.

[0003] The development of multidimensional force sensors faces the challenge of decoupling multidimensional force signals. Traditional piezoresistive and piezoresistive sensing mechanisms, at the physical level, are for sensing and analyzing one-dimensional signals, making it difficult to analyze multidimensional force signals and requiring complex device structures in the design. Magnetic fields, being three-dimensional vector fields, can be mapped bidirectionally between magnetic fields and multidimensional force fields through careful design and calculation, thus serving as a force sensing mechanism and effectively solving the problem of multidimensional force sensing and analysis. Compared to traditional mechanisms, there are currently fewer practical options available in this area, and challenges remain, including insufficient decoupling dimensions, poor decoupling effects, and cumbersome manufacturing processes.

[0004] Some existing technologies cannot achieve natural decoupling, leading to complex calculation processes and limited accuracy. Other existing technologies can achieve self-decoupling, but only for normal and tangential force stimulation; they cannot decouple forces on the x and y axes within the same xy-plane.

[0005] Therefore, to address the above challenges, there is a need for a novel flexible magnetic multidimensional force device with the potential for large-scale production. This device should be designed to achieve multidimensional force decoupling in various spatial directions while maintaining high mechanical performance, and should also be simple to manufacture and inexpensive. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention proposes a flexible multidimensional force sensor based on a centripetal gradient magnetic field design and its fabrication method. This method constructs a three-dimensional magnetic field with a centripetal gradient magnetic flux density, and the fabrication process is compatible with large-scale manufacturing, making it suitable for multidimensional force sensing and analysis, particularly for applications such as robotic tactile sensing. Furthermore, a flexible buffer layer is proposed, which utilizes gradient stress structures and gradient material moduli to design and control the sensor's stress sensitivity in both the tangential and normal directions, making it suitable for flexible multidimensional force sensors.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A first aspect of the present invention relates to a flexible multidimensional force sensor, comprising, from top to bottom:

[0009] The protective layer includes a flexible substrate material with force-sensitive properties;

[0010] The magnetic film layer has a cross-shaped groove on the bottom surface, and the edge of the groove is arc-shaped, which can form a centripetal magnetic field with gradient magnetic flux.

[0011] The buffer layer comprises a stepped strain material;

[0012] And, the transmission layer, including an electromagnetic effect chip with triaxial magnetic field sensing capability and its readout circuit.

[0013] Optionally, the cross-section of the protective layer is trapezoidal, spherical, or conical.

[0014] Optionally, the hardness of the stepped strain material increases sequentially from top to bottom.

[0015] Optionally, the electromagnetic effect chip is a three-axis Hall sensor chip or a three-axis magnetoresistive sensor chip.

[0016] Optionally, in the stepped strain material, the hardness between different layers of the strain material is controlled by the amount of curing agent added.

[0017] Optionally, the magnetic film layer is made of NdFeB / polydimethylsiloxane composite material or other polymer materials composed of rare earth magnetic materials and flexible polymer materials.

[0018] Optionally, the center of the cross-shaped groove in the magnetic film layer is aligned with the center of the north magnetic pole of the electromagnetic effect chip.

[0019] A second aspect of the present invention relates to a method for fabricating a flexible multidimensional force sensor, comprising the following steps:

[0020] A structure with a cross-shaped groove at the bottom is obtained by molding or etching, and the edge of the groove is arc-shaped; a magnetic field density modulus that decreases towards the center is induced to form a centripetal gradient magnetic field in the central region of the cross-shaped groove, and the magnetic flux density gradient decreases, thus obtaining a magnetic film layer.

[0021] A stepped buffer layer is prepared by molding or etching.

[0022] An electromagnetic effect chip with triaxial magnetic field sensing capability and its readout circuit are set up as the transmission layer.

[0023] The transmitting layer, buffer layer, magnetic film layer, and molded protective layer are bonded and assembled from bottom to top to obtain the flexible multidimensional force sensor.

[0024] A third aspect of the present invention relates to the above-mentioned decoupling method for flexible multidimensional force sensors, comprising the following steps:

[0025] The three-dimensional magnetic field of the magnetic film layer is represented as the superposition of three orthogonal sine waves;

[0026] The magnetic flux density and ratio beneath the magnetic film layer are calculated using the static magnetic scalar potential, magnetic field, and magnetization.

[0027] Based on the magnetic flux density and ratio, calculate the deformation in the x, y, and z directions in the three-dimensional coordinate system;

[0028] According to Hooke's Law, the forces in the three-dimensional direction are calculated using the contact area, shear modulus / elastic modulus, deformation, and thickness.

[0029] A fourth aspect of the present invention relates to the application of the aforementioned magnetic film layer in inducing the construction of a centripetal gradient magnetic field, wherein the magnetic film layer can induce the formation of a magnetic field density modulus that decreases towards the center through a cross-shaped groove structure, thereby forming a centripetal gradient magnetic field in the central region of the cross-shaped groove; and the magnetic flux density gradient decreases.

[0030] The specific principle is that, compared with the unstructured planar magnetic film, the magnetic film with the cross-shaped groove structure induces magnetic field lines to flow along the surface of the cross-shaped groove structure, forming a centripetal tangential vector component magnetic field that is different from the unidirectional normal magnetic field of the planar magnetic film, so that a centripetal magnetic field exists in a specific area below the original planar magnetic film.

[0031] Optionally, the magnetic film material can be a flexible material or a metallic material, and the magnetic film can be a rigid material or a flexible material. Different fabrication processes, such as photolithography or molding, can be used depending on the material.

[0032] Optionally, the size of the cross-shaped groove can be adjusted according to the required size of the central force decoupling region of the sensor. The central area of ​​the cross-shaped groove is the size of the force decoupling region. For example, in Example 1, the central area is 3mm*3mm. At the same time, different fabrication processes, such as photolithography or molding, can be selected according to the size of the groove.

[0033] A fifth aspect of the invention relates to a robotic arm comprising the aforementioned flexible multidimensional force sensor.

[0034] The beneficial effects of this invention are:

[0035] The sensor in this application achieves natural decoupling in terms of magnetic field design and has decoupling capability in all three axes.

[0036] The buffer layer of this application adopts a gradient design, which makes the sensor have different response slopes at different stress stages when subjected to stress, greatly improving the force measurement range of the device, and the sensing sensitivity and range are the same on all three axes. Attached Figure Description

[0037] The invention will now be further described with reference to the accompanying drawings.

[0038] Figure 1 This is a schematic diagram of the structure of the flexible multidimensional force sensor of this application;

[0039] Figure 2 This is a schematic diagram of the structure of the central magnetic film layer of the sensor in this application;

[0040] Figure 3 This is a schematic diagram of the magnetic field gradient on the lower surface of the sensor in this application;

[0041] Figure 4 This is a schematic diagram of the magnetic field gradient of each sensing surface below the sensor in this application;

[0042] Figure 5 This is a simulated cross-sectional view of the magnetofluid field of the magnetic film layer in this application.

[0043] Figure 6 This is a top view of the magnetic flux field simulation of the magnetic film layer in this application;

[0044] Figure 7 This is a top view of the simulated magnetofluid field in the central region of the magnetic film layer in this application.

[0045] Figure 8 This is a diagram showing the response of the magnetic field to triaxial force in this application;

[0046] Figure 9 The magnetic field of this application identifies the force direction in the xoy plane;

[0047] Figure 10 Image showing the etching effect of the magnetic film layer in this application;

[0048] Figure 11 Example diagrams illustrating the application of the sensors in robotic arms in this application;

[0049] Figure 12 This is a diagram of the robotic arm touch data from this application.

[0050] The components corresponding to the numbers in the diagram are as follows:

[0051] 1. Protective layer; 2. Magnetic film layer, with a gray cross-shaped groove in the middle 12; 3. Top layer of the first inner buffer layer; 4. Second inner buffer layer; 5. Third inner buffer layer; 6. Transmission layer triaxial electromagnetic effect chip; 7. Buffer filler; 8. First outer buffer layer; 9. Second outer buffer layer; 10. Third outer buffer layer; 11. Transmission layer circuit board; 12. Cross-shaped groove. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] In some embodiments of this application, a flexible multidimensional force sensor is disclosed, the structural diagram of which is shown below. Figure 1 As shown.

[0054] (1) The top layer consists of a protective layer 1 with a raised structure. This layer can be made of various inert flexible substrate materials, such as soft silicone, PDMS, etc. The design idea is to protect the sensor from external corrosion, oxidation and other interference. At the same time, the raised structure has force-sensitive characteristics, especially sensitive to tangential force input. The thickness of this layer can be changed according to different usage scenarios, and it can also be changed into trapezoidal, spherical, conical and other shapes.

[0055] (2) Please refer to Figures 2-7 The second layer is a flexible magnetic film layer 2, which is the core layer of the sensor. This sensor uses a composite material made of rare-earth magnetic materials and a flexible substrate material, such as NdFeB magnetic powder mixed with Ecoflex soft silicone or FeSmN magnetic powder mixed with Ecoflex soft silicone, both of which can achieve sensing functions. Below this layer is a cross-shaped groove 12, with an arc-shaped surface formed by rounded corners of a central square area. The size of the central square area is related to the size of the magnetoelectric conversion chip in the fourth layer; the former needs to be larger than the latter. Specific dimensions and corresponding fabrication methods can be found in Example 1.

[0056] 2. After the layer is prepared, it needs to be magnetized on a magnetizer to make it a permanent magnet. The magnetization direction of the magnetizer is the normal direction of the planar layer. It can pass through the plane with the N pole facing down or the S pole facing down. The different directions only affect the sign of the normal sensing signal. After force-magnetic field calibration, it will not affect the device performance.

[0057] (3) The third layer is a buffer layer. This buffer layer has a clever gradient stress structure, which can effectively balance the normal and tangential stress deformation of the device. This layer first contains sublayers with increasing gradients from top to bottom. Each gradient layer uses a flexible strain material with different proportions (there are no restrictions on specific substrate materials, only that the hardness of the material can be adjusted through the preparation ratio). For example, the top layer uses PDMS with 10% curing agent, the middle layer uses PDMS with 30% curing agent, and the bottom layer uses PDMS with 50% curing agent. This gradient design allows the sensor to have different response slopes at different stress stages when subjected to stress, greatly improving the device's force measurement range. In some specific examples, the buffer layer structure is as follows: Figure 1 As shown, the first inner buffer layer 3, the second inner buffer layer 4, and the third inner buffer layer 5 are sequentially arranged above the triaxial electromagnetic effect chip 6 of the transmission layer from top to bottom, and are surrounded by buffer filler 7. A first outer buffer layer 8, a second outer buffer layer, and a third outer buffer layer 10 are disposed outside the buffer filler 7. Both the inner and outer buffer layers can be arranged in a gradient. Those skilled in the art should also understand that... Figure 1 The structure shown is just an example; the arrangement and number of buffer layers can be adjusted according to actual needs.

[0058] (4) The fourth layer is the output layer. This layer contains the magnetoelectric effect chip and the corresponding readout circuit. The magnetoelectric effect chip is required to be a chip with three-dimensional magnetic field sensing capability. Optional devices include triaxial Hall sensors or triaxial magnetoresistive sensors. Since the sensing mechanism of the sensor in this application is based on a three-dimensional design on a magnetic field, the selection of different sensing chips has little impact on decoupling and multi-directional sensing capability; it only affects the data response time and range. After calibrating the three-dimensional data, stable three-dimensional decoupling and multi-dimensional force sensing effects can be exhibited. The circuit layer of this layer can better meet the application scenarios of the sensor. The mounting requires rigid PCB or flexible PCB materials. For example, in curved surface integration, flexible PI material is required as the circuit substrate. In some specific examples, the structure of the output layer is as follows: Figure 1 As shown, the triaxial electromagnetic effect chip 6 of the transmission layer is disposed in the middle of the transmission layer circuit board 11, and its upper end surface is attached to the bottom surface of the third inner buffer layer 5.

[0059] In some embodiments of this application, the materials that can be used for each layer of the sensor are as follows:

[0060] (1) Protective layer 1: Ecoflex silicone-based materials and other inert flexible polymer materials

[0061] (2) Magnetic film layer 2: NdFeB / polydimethylsiloxane (PDMS) and other magnetic flexible composite materials;

[0062] (3) Buffer layer: Flexible materials such as PDMS or SEBS with different proportions.

[0063] (4) Transmission layer: The substrate used for the circuit can be a silicon board or a PI flexible board.

[0064] In some embodiments of this application, a centrally symmetrical arc-shaped microstructure is constructed in the second layer, namely the magnetic film layer 2, forming a magnetic field with gradient magnetic flux on the lower surface and directly below the magnetic film layer 2, such as... Figure 3 and Figure 4 As shown; a gradient magnetic field can form centripetal rotating magnetic field lines in three-dimensional space, such as... Figure 5 , Figure 6 , Figure 7 As shown. The decoupling principle of this three-dimensional magnetic field can be proven by the following mathematical derivation:

[0065] Simulations show that the area directly below a three-dimensional magnetic field can be represented as the superposition of three orthogonal sine waves:

[0066] M x =M0sin(kx),M y =M0sin(kx),M z =M0cos(kx) (S1)

[0067] Where k is the wave number and M0 is the maximum amplitude of each component. The magnetostatic scalar potential beneath magnetic film layer 2 is calculated using a second-order differential equation. They can be derived separately as follows:

[0068]

[0069] In MKS-SI units, the magnetic flux density B is proportional to the sum of the magnetic field H and the magnetization M, that is:

[0070] B=μ0(H+M)(S3)

[0071] Where μ0 is the free space permeability, which is 4π×10⁻⁶. -7 H·m⁻¹. The magnetic field H is a scalar potential. The negative gradient means that the magnetization M outside the magnetic material is zero.

[0072]

[0073] M = 0 (S5)

[0074] Combining equations (S2)-(S5), the magnetic flux densities Bx (along the x-axis) and Bz (along the z-axis) below the magnetic film layer 2 can be obtained as follows:

[0075]

[0076]

[0077]

[0078] Based on (S8), (S9), and (S10), we can calculate B at any point (x,z) or (y,z) on the xz plane or yz plane below the magnetic film layer 2. x B y and B z Total magnetic flux density B and ratio R B as follows:

[0079]

[0080]

[0081]

[0082]

[0083] We can then calculate the change in magnetic intensity (ΔB%) under displacement load along the z-axis (ΔZ) as follows:

[0084]

[0085] Summarizing the above formulas, the change in magnetic field caused by the longitudinal displacement ΔZ resulting from the normal pressure on magnetic film layer 2, i.e., the displacement of the central part of magnetic film layer 2 caused by the pressure, is ΔB(%) = e kΔZ ―1

[0086] When subjected to a resultant force with a tangential component, R B The changes in B(x) and B(z) are used to calculate the displacements Δx and Δy of the magnet in the x and y directions and the displacement Δz in the z direction.

[0087] From (S8) and (S9), we can obtain:

[0088]

[0089]

[0090]

[0091] Therefore, the shear component F of the external force F x and normal component F z The displacements Δx and Δz of the magnet can be used to calculate this, because according to Hooke's Law, the applied force is linearly related to the displacement of the elastic material.

[0092]

[0093]

[0094]

[0095] Where S is the contact area, and γ, ε, G, E, and h are the shear strain, normal strain, shear modulus, elastic modulus, and thickness of the elastic layer, respectively. For isotropic elastic materials, G = E / (2(1+V)), where V is the Poisson's ratio of the material. By aligning the center of the cross groove 12 of the magnetic film layer 2 with the center of the north magnetic pole of the triaxial Hall sensor, and taking this static state as the initial point, we can consider setting the B(x,y,z) state to zero. Substituting Δx, Δy, and Δz from equation (S14-S16) and introducing four compensation coefficients, we can obtain the decoupling calculation formula for forces in any direction along the triaxial axis:

[0096]

[0097]

[0098]

[0099] Where c1 and c2 are the compensation coefficients for elastic modulus and shear modulus, respectively, because the overall elastic / shear modulus of the sensor is a result of the modulus of the top or middle layers (as well as some unseen defects in the manufacturing process). b1-b3 are the system biases, representing the calibration of the fourth-layer magnetoelectric chip signal in different applications.

[0100] Example 1:

[0101] This embodiment discloses the fabrication of the above-mentioned sensor, specifically using the following materials:

[0102] (1) Protective layer 1: Ecoflex-0030 material; 1mm thick, trapezoidal; bottom length and width are 10mm*10mm, top length and width are 6mm*6mm.

[0103] (2) Magnetic film layer 2: NdFeB / Ecoflex-0030; length and width are 10mm*10mm, thickness is 1mm; bottom groove depth is 0.5mm, and the size of the groove center area is 3mm*3mm.

[0104] (3) Buffer layer: The gradient layer uses PDMS with a thickness of 0.5mm, the top layer is 5mm*5mm in length and width, and the gradient is +1mm / layer; the filler uses Ecoflex-0030 with a thickness of 2mm and a length and width of 10mm*10mm.

[0105] (4) Transmission layer: A three-axis Hall sensor chip is used, with a chip length and width of 3mm*3mm. The PCB substrate uses a silicon substrate with an overall thickness of 1.2mm.

[0106] Preparation process:

[0107] 1. Design molds and perform 3D modeling based on the thickness and shape of each layer, and use a 3D printer to prepare the molds; pay attention to the mold design for the cross groove 12 structure of the second layer, namely the magnetic film layer 2.

[0108] 2. Position the PCB of the outgoing layer (fourth layer) and mark the center of the Hall sensor chip to complete the fabrication of the fourth layer.

[0109] 3. Mix PDMS solution and curing agent in a 10:1 ratio, stir mechanically for 2-3 minutes, defoam under pressure for 0.5 minutes, pour into a gradient structure mold, cure at 80 degrees Celsius for one hour, take it out, align the four-layer Hall sensor chip, place the gradient structure in the designed position, pour in solution-like Ecoflex-0030 to fill, and thermosetting to complete the preparation of the third layer.

[0110] 4. Prepare the Ecoflex-0030 mixed solution, then add the mixed NdFeB rare earth material with a diameter of 5 micrometers at a ratio of 1:1 with the Ecoflex-0030 mixed solution and stir at ultra-high speed with a planetary gravity mixer for 2 minutes, and then defoam under pressure for 0.5 minutes. After that, pour it into the mold of the magnetic film layer 2 structure, heat-cur it into a film, take it out, and put it into a unidirectional magnetizer. Magnetize the lower surface as the north pole and the magnetization intensity is 2T. The magnetic film layer 2 is then prepared. Use silicone rubber adhesive to adhere it to the buffer layer, and pay attention to center alignment.

[0111] 5. Simultaneously, pour the solution of Ecoflex-0030 into the corresponding mold of the top layer, heat-cur it into a film, and then remove it. After the protective layer 1 is prepared, use silicone rubber adhesive to adhere it above the magnetic film layer 2, paying attention to center alignment, and the device preparation is complete.

[0112] like Figure 8 and Figure 9 As shown, the sensor prepared by the above method can communicate with the computer by connecting it to an Arduino host computer and transmit three-dimensional sensing signals. Force testing on the three axes by a press shows that the magnetic field responses of the sensor on the three axes do not interfere with each other when pressure is applied. When pressure is applied in multiple arbitrary directions in the horizontal direction, its x-axis and y-axis magnetic fields can distinguish different directions with high precision, proving that it has good decoupling properties.

[0113] Example 2:

[0114] This embodiment discloses the fabrication of the above-mentioned sensor, specifically using the following materials:

[0115] (1) Protective layer 1: Ecoflex-0030 material; 1mm thick, semi-circular; bottom length and width are 3mm*3mm.

[0116] (2) Magnetic film layer 2: NdFeB / Ecoflex-0030; thickness 0.5mm, bottom groove depth 0.25mm; length and width 3mm*3mm.

[0117] (3) Buffer layer: The gradient layer uses Ecoflex-0030 with a thickness of 0.5mm. The top layer is 1mm*1mm in length and width, and the gradient is +1mm / layer. The filler uses Ecoflex-0010 with a thickness of 1mm and a length and width of 3mm*3mm.

[0118] (4) Transmission layer: A three-axis Hall sensor chip is used, with a chip length and width of 3mm*3mm. The PCB substrate uses a flexible PI substrate with an overall thickness of 1mm.

[0119] Preparation process:

[0120] 1. Based on the thickness of each layer, prepare a four-layer smooth film according to the material preparation and thermosetting process in Example 1;

[0121] 2. The structure of protective layer 1, magnetic film layer 2, and buffer layer is etched using low-power laser engraving to create the designed structure and shape, such as... Figure 10 As shown;

[0122] 3. Bond the four layers together using soft silicone adhesive, while ensuring the center of the magnetoelectric chip is aligned with the four layers above.

[0123] According to the above embodiments, the sensor device of this application can be applied in fields such as machine touch sensing, for example, it can be applied in the touch components of a robotic arm. Figure 11 and Figure 12 As shown, when the robotic arm touches human skin, it detects a lump. The sensor receives an increase in oblique force, and the magnetic fields along the x and z axes change. After repeated pressing, it is confirmed to be a lump.

[0124] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0125] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A flexible multi-dimensional force sensor, characterized by, From top to bottom, in order, include: a protective layer, including a flexible base material with force-sensitive properties; a magnetic film layer, the bottom surface is provided with a cross-shaped groove, and the edges of the groove are arc-shaped, capable of forming a centripetal magnetic field with gradient magnetic flux; a buffer layer, including a stepped strain material; and a transmission layer, including an electromagnetic effect chip with three-axis magnetic field sensing capability and its readout circuit.

2. The flexible multi-dimensional force sensor of claim 1, wherein, The cross-section of the protective layer is trapezoidal, spherical or conical.

3. The flexible multi-axis force sensor of claim 1, wherein, The hardness of the stepped strain material increases from top to bottom.

4. The flexible multi-axis force sensor of claim 1, wherein, The electromagnetic effect chip is a three-axis Hall sensor chip or a three-axis magnetoresistive sensor chip.

5. The flexible multi-axis force sensor of claim 1, wherein, The material of the magnetic film layer is a polymer material composed of rare earth magnetic material and flexible high polymer material.

6. The flexible multi-axis force sensor of claim 1, wherein, The center of the cross-shaped groove of the magnetic film layer is in a straight line with the center of the north magnetic pole of the electromagnetic effect chip.

7. A method of manufacturing a flexible multi-dimensional force sensor, characterized by, The method comprises the following steps: A structure with a cross-shaped groove at the bottom is prepared by mold forming or etching forming, and the edges of the groove are arc-shaped; a magnetic field density modulus that decreases towards the center is induced to form a centripetal gradient magnetic field in the central area of the cross-shaped groove, and the magnetic flux density gradient decreases to obtain the magnetic film layer; A buffer layer with a stepped shape is prepared by mold forming or etching forming; An electromagnetic effect chip with three-axis magnetic field sensing capability and its readout circuit are set as the transmission layer; The transmission layer, buffer layer, magnetic film layer and mold-formed protective layer are bonded and assembled from bottom to top to obtain the flexible multi-dimensional force sensor.

8. The decoupling method of the flexible multi-dimensional force sensor according to any one of claims 1-6, characterized in that, The method comprises the following steps: The centripetal magnetic field of the magnetic film layer is represented as the superposition of three orthogonal sine waves; The magnetic flux density and ratio below the magnetic film layer are calculated by static magnetic scalar potential, magnetic field and magnetization intensity; According to the magnetic flux density and ratio, the deformation variables in the x, y and z directions of the three-dimensional coordinate system are calculated; According to Hooke's law, the three-dimensional directional force is calculated by the contact area, shear modulus / elastic modulus, deformation variables and thickness.

9. Use of a magnetic film layer according to any one of claims 1 to 6 for inducing a centripetal gradient magnetic field in a construction, characterized in that, The magnetic film layer can induce a magnetic field density modulus that decreases towards the center through a cross-shaped groove structure to form a centripetal gradient magnetic field in the central area of the cross; and the magnetic flux density gradient decreases.

10. A robot, characterized in that The flexible multi-dimensional force sensor of any one of claims 1-6 is included.

Images