CN114383761B - Pressure sensor with unidirectional conductive function and preparation method and application thereof - Google Patents

Abstract

The invention relates to the field of sensor technology, and specifically discloses a pressure sensor with a single-directional conductive function and its preparation method and application. The pressure sensor includes: two layers of flexible electrodes and a dielectric layer located between the two layers of flexible electrodes; the dielectric layer includes a base material and magnetic conductive fibers distributed in the base material, and the magnetic conductive fibers are perpendicular to Flexible electrodes are oriented and arranged. The pressure sensor provided by the invention has the advantages of flexibility, high sensitivity and wide monitoring range.

Description

Pressure sensor with single-directional conductive function and preparation method and application thereof

Technical field

The invention relates to the field of sensor technology, and in particular to a pressure sensor with a single-directional conductive function and its preparation method and application.

Background technique

Real-time and accurate use of electronic sensors to measure important information about the human body plays an important role in health monitoring and medical care. Human skin can naturally distinguish between pressure and various mechanical stimuli or mechanical deformations and conduct independent sensing. Therefore, wearable electronic sensing devices should also have the ability to detect Ability to sense various mechanical stresses with high sensitivity. However, most current sensors rely on changes in contact resistance to achieve pressure sensing. Their deformation range is small and they cannot achieve high sensitivity and wide monitoring range.

Therefore, preparing pressure sensors with high sensitivity and wide monitoring range is still a hot topic in the field of sensors.

Contents of the invention

The purpose of the present invention is to overcome the technical problems existing in the prior art and provide a pressure sensor with a single-directional conductive function and its preparation method and application.

In order to achieve the above object, a first aspect of the present invention provides a pressure sensor with a single-directional conductive function. The pressure sensor includes: two layers of flexible electrodes and a dielectric layer located between the two layers of flexible electrodes; the dielectric layer includes A base material and magnetic conductive fibers distributed in the base material, and the magnetic conductive fibers are oriented perpendicular to the flexible electrode.

A second aspect of the present invention provides a method for preparing a pressure sensor with a single-directional conductive function. The method includes the following steps:

Make the magnetic conductive fibers directionally distributed in the matrix material and assemble the flexible electrode;

Wherein, the magnetic conductive fibers are oriented and arranged perpendicularly to the flexible electrodes.

A third aspect of the present invention provides a pressure sensor prepared by the aforementioned method.

A fourth aspect of the present invention provides an application of the aforementioned pressure sensor in the field of wearable devices and/or human-computer interaction.

A fifth aspect of the present invention provides a wearable device, which includes the aforementioned pressure sensor.

The pressure sensor provided by the invention has the advantages of flexibility, high sensitivity and wide monitoring range.

Description of the drawings

Figure 1 is a schematic diagram of directionally arranged magnetic conductive fibers according to a specific embodiment of the present invention;

Figure 2 is a schematic diagram of a sensor changing with pressure according to a specific embodiment of the present invention;

In Figure 3, (a) is a graph showing how the ratio of the real-time current to the initial current changes with the pressure of the sensors prepared in Example 1, Example 4 and Comparative Example 1 of the present invention under different pressures; (b) respectively It is a graph showing how the ratio of the real-time current to the initial current changes with pressure changes for the sensors prepared in Example 1, Example 2 and Example 3 of the present invention under different pressures; (c) is a graph of Example 1 under no pressure. The relationship between current and voltage (volt-ampere curve) of the prepared sensor at different voltages; (d) is a curve chart of the real-time current and pressure changes of the sensor (Example 1) of a specific embodiment of the present invention under different pressures. ; (e) is a current diagram of a pressure sensor of a specific embodiment of the present invention under the same pressure and different frequencies; (f) is a real-time current diagram of a sensor of a specific embodiment of the present invention (Example 1) under pressure stimulation. The change curve; (g) is the change curve of the real-time current of the sensor (Example 1) of a specific embodiment of the present invention under stimulation under the same pressure 3000 times.

Detailed ways

The endpoints of ranges and any values disclosed herein are not limited to the precise range or value, but these ranges or values are to be understood to include values approaching such ranges or values. For numerical ranges, the endpoint values of each range, the endpoint values of each range and individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges. These values The scope shall be deemed to be specifically disclosed herein.

A first aspect of the present invention provides a pressure sensor with a single-directional conductive function. The pressure sensor includes: two layers of flexible electrodes and a dielectric layer located between the two layers of flexible electrodes; the dielectric layer includes a base material and a layer distributed in Magnetic conductive fibers in the base material, and the magnetic conductive fibers are oriented perpendicular to the flexible electrodes.

According to some embodiments of the present invention, the weight ratio of the base material to the magnetic conductive fiber may be (3-25):1 (such as 3:1, 4:1, 5:1, 10:1, 15:1, Any value between 20:1, 25:1 or above).

According to some embodiments of the present invention, the magnetic conductive fiber may be cylindrical.

Preferably, the magnetic conductive fiber has a length of 0.5-3mm and a diameter of 0.1-0.3mm.

According to some embodiments of the present invention, the conductivity of the magnetic conductive fiber may be (1.5-2)×10 ^-3 Ω·cm; the magnetic permeability may be (8-9)×10 ³ H/m.

According to some embodiments of the present invention, the magnetic conductive fiber can be selected from at least one of nickel-plated carbon fiber, nickel-plated metal fiber, nickel-plated stainless steel, iron-plated carbon fiber and cobalt-plated carbon fiber, preferably nickel-plated carbon fiber and/or Cobalt plated carbon fiber.

The present invention has no special limitation on the thickness of the dielectric layer, as long as it can meet the requirements of the present invention. For example, the thickness of the dielectric layer can be 2 mm to 5 mm.

According to some embodiments of the present invention, the base material may be selected from thermal curing materials and/or photo curing materials.

In the present invention, the thermal conductivity of the base material can be 0.134-0.159W/M*K, the light transmittance can be 95-100%, and it has physiological inertness and good chemical stability. Among them, the base material has electrical insulation, weather resistance, and shear resistance, and can be used for a long time at -50°C to 200°C.

According to some embodiments of the present invention, the thermosetting material may be selected from polydimethylsiloxane and/or silicone.

According to some embodiments of the present invention, the photocurable material may be photosensitive polyurethane.

According to some embodiments of the present invention, the thicknesses of the two layers of flexible electrodes may independently range from 20 μm to 70 μm.

According to some embodiments of the present invention, the flexible electrode may be selected from interdigital electrodes and/or conductive metal electrodes.

According to some embodiments of the present invention, the upper electrode of the pressure sensor is a conductive metal electrode, and the lower electrode is an interdigital electrode.

According to some embodiments of the present invention, the number of pairs of interdigital electrodes is 8-20 pairs.

According to some embodiments of the present invention, the interdigital line width and line spacing of the interdigital electrode are each independently 100-200 μm.

According to a preferred embodiment of the present invention, the interdigital electrode is prepared by magnetron sputtering, wherein the magnetron sputtering time is 20-40 minutes.

According to a preferred embodiment of the present invention, the magnetron sputtering causes the metal thickness deposited on the interdigital electrodes to be 70-100 nm. Preferably, the deposited metal is selected from copper and/or gold, preferably copper.

According to some embodiments of the present invention, the conductive metal electrode is a mesh electrode; the conductive metal electrode is selected from at least one of copper electrode, nickel cloth and silver cloth.

According to some embodiments of the present invention, the sensitivity of the pressure sensor may be 10,000-40,000 kPa ^-1 .

A second aspect of the present invention provides a method for preparing a pressure sensor with a single-directional conductive function. The method includes the following steps:

Make the magnetic conductive fibers directionally distributed in the matrix material and assemble the flexible electrode;

Wherein, the magnetic conductive fibers are oriented and arranged perpendicularly to the flexible electrodes.

According to some embodiments of the present invention, the method of assembling the flexible electrode includes: solidifying the flexible electrode and a base material distributed with magnetic conductive fibers together;

Alternatively, after the matrix material on which the magnetic conductive fibers are distributed is cured, the flexible electrodes are adhered.

Wherein, the flexible electrodes and the matrix material on which the magnetic conductive fibers are distributed are solidified together, which may mean that one or more flexible electrodes and the matrix material on which the magnetic conductive fibers are distributed are solidified together.

According to some embodiments of the present invention, the magnetic conductive fibers are directionally distributed in the base material in the following manner:

The magnetic conductive fibers are mixed with the matrix material and placed in a mold, and the conductive fibers are oriented and distributed in the matrix material in a direction parallel to the magnetic field under the induction of a magnetic field perpendicular to the mold.

In the present invention, the flexible electrode on the upper surface is first covered and then solidified, which can reduce the contact resistance, help stabilize the device, and simplify the preparation process.

According to some embodiments of the present invention, the weight ratio of the base material to the magnetic conductive fiber is (5-20):1.

The magnetic conductive fiber, the base material and the flexible electrode described in the second aspect of the present invention have the same meaning as the aforementioned first aspect. No further details will be given here.

According to some embodiments of the present invention, the mold may be a flat mold. In order to obtain better results, the bottom of the mold is made of sandpaper. Among them, the sandpaper surface has a sphenoid ridge structure, which can effectively improve the sensing sensitivity.

According to some embodiments of the invention, the mixing is performed with stirring. The stirring speed can be 1500-3000rpm, and the stirring time can be 20-30min;

According to some embodiments of the present invention, the conditions for the magnetic field induction may include: the magnetic field intensity is 0.1-0.3T; the magnetic field induction is performed under a uniform magnetic field.

According to some embodiments of the present invention, the curing is light curing or thermal curing.

Preferably, the photocuring conditions include: the wavelength of ultraviolet light is 360-380nm, the intensity is 20-50W, and the time is 20-30s.

Preferably, the thermal curing conditions include: 70-80°C and a time of 60-90 minutes.

In the present invention, there is no particular restriction on the assembly method of the flexible electrode, as long as it can meet the requirements of the present invention. For example, the assembly method may be lamination and/or pasting.

A third aspect of the present invention provides a pressure sensor prepared by the aforementioned method.

A fourth aspect of the present invention provides an application of the aforementioned pressure sensor in the field of wearable devices and/or human-computer interaction.

The method of the present invention can also be applied to 3D printing, and sample materials with specific patterns can be oriented and printed.

A fifth aspect of the present invention provides a wearable device, which includes the aforementioned pressure sensor.

The present invention will be described in detail below through examples.

Example 1

(1) Add 4g of nickel-plated carbon fiber (diameter: 0.2mm, length: 2mm, conductivity: 1.5×10-3Ω·cm, magnetic permeability: 8×103H/m) into 16g of base material (polydimethylsiloxane) alkane (PDMS)), stir for 20 minutes at 2000 rpm, mix evenly and pour into a flat mold (material: acrylic (polymethyl methacrylate; 4cm (length) × 4cm (width) × 2mm (height))), the bottom of the mold sandpaper with a rough surface), and scrape the mixed nickel-plated carbon fiber and base material surfaces (use a thin blade to evenly scrape the film on the base material), and then place the mold containing the nickel-plated carbon fiber and base material Placed in a magnetic field in a vertical direction, the nickel-plated carbon fiber is oriented and twisted along the direction of the magnetic field under the induction of a 0.2T magnetic field (uniform magnetic field) to obtain a dielectric layer precursor; then, on the obtained dielectric layer precursor The surface is covered with a conductive film (copper mesh, 4cm (length) × 4cm (width)) with a thickness of 50 μm, left to stand at room temperature, and self-leveled for 10 minutes to obtain a dielectric layer precursor whose upper surface is covered with a conductive film;

The obtained dielectric layer precursor was thermally cured at 70°C for 60 minutes to obtain a dielectric layer with an upper surface covered with a conductive film, where the thickness of the dielectric layer was 2 mm;

(2) Use magnetron sputtering (time: 30 minutes) to prepare interdigital electrodes. The thickness of copper deposited on the interdigital electrodes is 100nm, the thickness of the interdigital electrodes is 72μm, and the interdigital line width and line spacing of the interdigital electrodes are respectively 150 μm; adhere it as a lower electrode to the lower surface of the above-mentioned dielectric layer whose upper surface is covered with a conductive film.

Example 2

(1) Add 4.4g of nickel-plated carbon fiber (diameter of 0.2mm, length of 2mm, conductivity of 1.5×10-3Ω·cm, magnetic permeability of 8×103H/m) into 15.6g of base material (polydimethyl siloxane (PDMS), stir for 20 minutes at 2000 rpm, mix evenly and pour into a flat mold (material: acrylic (polymethylmethacrylate; 4cm (length) × 4cm (width) × 2mm (height)), The bottom of the mold is sandpaper with a rough surface), and the surface of the mixed nickel-plated carbon fiber and base material is scraped (use a thin blade to evenly scrape the film on the base material), and then the nickel-plated carbon fiber and base material are installed. The mold is placed in a vertical magnetic field, and the nickel-plated carbon fibers are oriented and twisted along the direction of the magnetic field under the induction of a 0.2T magnetic field (uniform magnetic field) to obtain a dielectric layer precursor; then, on the obtained dielectric layer The surface is covered with a conductive film (copper mesh, 4cm (length) × 4cm (width)) with a thickness of 50 μm, left to stand at room temperature, and self-leveled for 10 minutes to obtain a dielectric layer precursor whose upper surface is covered with a conductive film;

The obtained dielectric layer precursor was thermally cured at 70°C for 60 minutes to obtain a dielectric layer with an upper surface covered with a conductive film, where the thickness of the dielectric layer was 2 mm;

(2) Use magnetron sputtering (time: 30 minutes) to prepare interdigital electrodes. The thickness of copper deposited on the interdigital electrodes is 100nm, the thickness of the interdigital electrodes is 72μm, and the interdigital line width and line spacing of the interdigital electrodes are respectively 150 μm; adhere it as a lower electrode to the lower surface of the above-mentioned dielectric layer whose upper surface is covered with a conductive film.

Example 3

(1) Add 3.6g of nickel-plated carbon fiber (diameter of 0.2mm, length of 2mm, conductivity of 1.5×10-3Ω·cm, magnetic permeability of 8×103H/m) into 16.4g of base material (polydimethyl siloxane (PDMS), stir for 20 minutes at 2000 rpm, mix evenly and pour into a flat mold (material: acrylic (polymethylmethacrylate; 4cm (length) × 4cm (width) × 2mm (height)), The bottom of the mold is sandpaper with a rough surface), and the surface of the mixed nickel-plated carbon fiber and base material is scraped (use a thin blade to evenly scrape the film on the base material), and then the nickel-plated carbon fiber and base material are installed. The mold is placed in a vertical magnetic field, and the nickel-plated carbon fibers are oriented and twisted along the direction of the magnetic field under the induction of a 0.2T magnetic field (uniform magnetic field) to obtain a dielectric layer precursor; then, on the obtained dielectric layer The surface is covered with a conductive film (copper mesh, 4cm (length) × 4cm (width)) with a thickness of 50 μm, left to stand at room temperature, and self-leveled for 10 minutes to obtain a dielectric layer precursor whose upper surface is covered with a conductive film;

The obtained dielectric layer precursor was thermally cured at 70°C for 60 minutes to obtain a dielectric layer with an upper surface covered with a conductive film, where the thickness of the dielectric layer was 2 mm;

(2) Use magnetron sputtering (time: 30 minutes) to prepare interdigital electrodes. The thickness of copper deposited on the interdigital electrodes is 100nm, the thickness of the interdigital electrodes is 72μm, and the interdigital line width and line spacing of the interdigital electrodes are respectively 150 μm; adhere it as a lower electrode to the lower surface of the above-mentioned dielectric layer whose upper surface is covered with a conductive film.

Example 4

(1) Add 4g of nickel-plated carbon fiber (diameter: 0.2mm, length: 2mm, conductivity: 1.5×10-3Ω·cm, magnetic permeability: 8×103H/m) into 16g of base material (polydimethylsiloxane) alkane (PDMS)), stir for 20 minutes at 2000 rpm, mix evenly and pour into a flat mold (material: acrylic (polymethyl methacrylate; 4cm (length) × 4cm (width) × 2mm (height))), the bottom of the mold (The surface is a smooth acrylic material), and scrape the mixed nickel-plated carbon fiber and the base material's surface (use a thin blade to evenly scrape the film on the base material), and then put the nickel-plated carbon fiber and base material into the The mold is placed in a vertical magnetic field, and the nickel-plated carbon fibers are oriented and twisted along the direction of the magnetic field under the induction of a 0.2T magnetic field (uniform magnetic field) to obtain a dielectric layer precursor; then, the upper surface of the obtained dielectric layer is Cover it with a conductive film (copper mesh, 4cm (length) × 4cm (width)) with a thickness of 50 μm, let it stand at room temperature, and self-level for 10 minutes to obtain a dielectric layer precursor whose upper surface is covered with a conductive film;

The obtained dielectric layer precursor was thermally cured at 70°C for 60 minutes to obtain a dielectric layer with an upper surface covered with a conductive film, where the thickness of the dielectric layer was 2 mm;

(2) Use magnetron sputtering (time: 30 minutes) to prepare interdigital electrodes. The thickness of copper deposited on the interdigital electrodes is 100nm, the thickness of the interdigital electrodes is 72μm, and the interdigital line width and line spacing of the interdigital electrodes are respectively 150 μm; adhere it as a lower electrode to the lower surface of the above-mentioned dielectric layer whose upper surface is covered with a conductive film.

Comparative example 1

The process was carried out in the same manner as in Example 1, except that no magnetic field was used to induce the orientation of the nickel-plated carbon fibers.

Test the effect of the pressure sensor obtained above:

(a) in Figure 3 uses a linear motor to apply variable pressure to the pressure sensors prepared in Example 1, Example 4, and Comparative Example 1, in which a digital source meter Keithley-2400 (is used to apply a constant voltage , a digital sourcemeter Keithley-6517 was used to test the current. From the test results, it can be seen that the ratio of the real-time current to the initial current increases with the increase of the applied pressure.

The test results in (a) in Figure 3 show that the pressure sensors prepared in Example 1, Example 4 and Comparative Example 1 have better responsiveness to pressure.

Different curves and different slopes in (a) in Figure 3 respectively indicate that the pressure sensor prepared in Example 1 has a much higher responsiveness to pressure than Example 4 and Comparative Example 1.

The test conditions in (b) in Figure 3 are the same as in (a) in Figure 3, and respectively represent the response currents to different pressures in Example 1, Example 2 and Example 3.

Different curves and different slopes in (a) in Figure 3 respectively indicate that the pressure sensor prepared in Example 1 has a much higher responsiveness to pressure than Example 2 and Example 3.

(c) in Figure 3 is a linear relationship diagram between voltage and current tested on the pressure sensor prepared in Example 1. The test method is an electrochemical workstation, applying variable voltage and testing its current. The results show that the pressure sensor prepared in Implementation 1 is a pure resistive device.

The test methods for (d)-(g) in Figure 3 are the same as (a) and (b).

(d) in Figure 3 shows the current corresponding to the pressure sensor prepared in Example 1 under specific applied pressure (1-100kPa, such as 1kPa, 15kPa, 38kPa, 48kPa and 58kPa); the results show that the output current signal is at the same It is stable under pressure stimulation and increases with pressure increase.

(e) in Figure 3 shows that the output current of the pressure sensor prepared in Example 1 increases as the frequency increases, and does not increase as the frequency of applied force increases.

(f) in Figure 3 shows the application of force to the pressure sensor prepared in Example 1. The response time of the current is 30 ms, and a current signal is generated immediately upon application of force. It shows that the device signal responds quickly to pressure.

(g) in Figure 3 shows that the current signal of the pressure sensor prepared in Example 1 still maintains good stability after 3000 cycles.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical concept of the present invention, many simple modifications can be made to the technical solution of the present invention, including the combination of various technical features in any other suitable manner. These simple modifications and combinations should also be regarded as the disclosed content of the present invention. All belong to the protection scope of the present invention.

Claims (24)

1. A pressure sensor with a single-directional conductive function, characterized in that the pressure sensor includes: two layers of flexible electrodes and a dielectric layer located between the two layers of flexible electrodes; the dielectric layer includes a base material and a layer distributed in Magnetic conductive fibers in the matrix material, and the magnetic conductive fibers are oriented perpendicular to the flexible electrode; Wherein, the magnetic conductive fiber is selected from at least one of nickel-plated carbon fiber, nickel-plated metal fiber, nickel-plated stainless steel, iron-plated carbon fiber and cobalt-plated carbon fiber; the matrix material is selected from thermosetting materials and/or light-curing materials. . 2. The pressure sensor according to claim 1, wherein the weight ratio of the matrix material to the magnetic conductive fiber is (3-25):1; And/or, the magnetic conductive fiber is cylindrical; And/or, the conductivity coefficient of the magnetic conductive fiber is (1.5-2)×10 ^-3 Ω·cm; the magnetic permeability is (8-9)×10 ³ H/m. 3. The pressure sensor according to claim 2, wherein the magnetic conductive fiber has a length of 0.5-3mm and a diameter of 0.1-0.3mm. 4. The pressure sensor according to claim 3, wherein the magnetic conductive fiber is nickel-plated carbon fiber and/or cobalt-plated carbon fiber. 5. The pressure sensor according to any one of claims 1-4, wherein the thickness of the dielectric layer is 2mm-5mm. 6. The pressure sensor according to claim 5, wherein the thermal curing material is selected from polydimethylsiloxane and/or silicone; the light curing material is photosensitive polyurethane. 7. The pressure sensor according to any one of claims 1-4 and 6, wherein the thickness of the two layers of flexible electrodes is independently 20 μm-70 μm; And/or, the flexible electrode is selected from interdigital electrodes and/or conductive metal electrodes; The upper electrode of the pressure sensor is a conductive metal electrode, and the lower electrode is an interdigital electrode; The number of pairs of interdigitated electrodes is 8-20 pairs; The interdigital line width and line spacing of the interdigital electrode are each independently 100-200 μm. 8. The pressure sensor according to claim 7, wherein the conductive metal electrode is a mesh electrode; the conductive metal electrode is selected from at least one of copper electrode, nickel cloth and silver cloth. 9. The pressure sensor according to claim 5, wherein the thickness of the two layers of flexible electrodes is independently 20 μm-70 μm; And/or, the flexible electrode is selected from interdigital electrodes and/or conductive metal electrodes; The upper electrode of the pressure sensor is a conductive metal electrode, and the lower electrode is an interdigital electrode; The number of pairs of interdigitated electrodes is 8-20 pairs; The interdigital line width and line spacing of the interdigital electrode are each independently 100-200 μm. 10. The pressure sensor according to claim 9, wherein the conductive metal electrode is a mesh electrode; the conductive metal electrode is selected from at least one of copper electrode, nickel cloth and silver cloth. 11. The pressure sensor according to any one of claims 1-4, 6, 8-10, wherein the sensitivity of the pressure sensor is 10000-40000kPa ^-1 . 12. The pressure sensor according to claim 5, wherein the sensitivity of the pressure sensor is 10000-40000kPa ^-1 . 13. The pressure sensor according to claim 7, wherein the sensitivity of the pressure sensor is 10000-40000kPa ^-1 . 14. A method of preparing a pressure sensor with a single-directional conductive function, characterized in that the method includes: directionally distributing magnetic conductive fibers in a base material and assembling flexible electrodes; The magnetic conductive fibers are oriented and arranged perpendicular to the flexible electrode; The method of assembling the flexible electrode includes: solidifying the flexible electrode and the base material distributed with the magnetic conductive fibers together; or, after the base material distributed with the magnetic conductive fibers is cured, the flexible electrode is then adhered; wherein, the curing For light curing or heat curing; The magnetic conductive fibers are directionally distributed on the base material in the following manner: The magnetic conductive fibers are mixed with the matrix material and placed in a mold, and the conductive fibers are oriented and distributed in the matrix material in a direction parallel to the magnetic field under the induction of a magnetic field perpendicular to the mold; The weight ratio of the matrix material to the magnetic conductive fiber is (5-20):1; The magnetic conductive fiber is cylindrical; the length of the magnetic conductive fiber is 0.5-3mm, and the diameter is 0.1-0.3mm; The conductivity coefficient of the magnetic conductive fiber is (1.5-2)×10 ^-3 Ω·cm; the magnetic permeability is (8-9)×10 ³ H/m; The magnetic conductive fiber is selected from at least one of nickel-plated carbon fiber, nickel-plated metal fiber, nickel-plated stainless steel, iron-plated carbon fiber and cobalt-plated carbon fiber; The matrix material is selected from thermal curing materials and/or light curing materials. 15. The method according to claim 14, wherein the mold is a flat mold; the bottom of the mold is made of sandpaper; And/or, the mixing is performed under stirring; the stirring speed is 1500-3000rpm, and the stirring time is 20-30min; And/or, the conditions for the magnetic field induction include: the magnetic field intensity is 0.1-0.3T; the magnetic field induction is performed under a uniform magnetic field. 16. The method according to claim 15, wherein the magnetic conductive fiber is nickel-plated carbon fiber and/or cobalt-plated carbon fiber. 17. The method according to claim 15, wherein the thermal curing material is selected from polydimethylsiloxane and/or silicone; the light curing material is photosensitive polyurethane. 18. The method according to claim 15, wherein the photocuring conditions include: the wavelength of ultraviolet light is 360-380nm, the intensity is 20-50W, and the time is 20-30s; the thermal curing conditions include: 70-80℃, time 60-90min. 19. The method according to any one of claims 14-18, wherein the thickness of the flexible electrode is 20 μm-70 μm; And/or, the flexible electrode is selected from interdigital electrodes and/or conductive metal electrodes; The upper electrode of the pressure sensor is a conductive metal electrode, and the lower electrode is an interdigital electrode; The number of pairs of interdigitated electrodes is 8-20 pairs; The interdigital line width and line spacing of the interdigital electrode are each independently 100-200 μm; The interdigital electrode is prepared by magnetron sputtering, wherein the magnetron sputtering time is 20-40 minutes, And/or, the magnetron sputtering causes the thickness of the metal deposited on the interdigital electrode to be 70-100 nm, and the deposited metal is selected from copper and/or gold. 20. The method according to claim 19, wherein the conductive metal electrode is a mesh electrode; the conductive metal electrode is selected from at least one of copper electrode, nickel cloth and silver cloth. 21. The method of claim 19, wherein the deposited metal is selected from copper. 22. The pressure sensor prepared by the method according to any one of claims 14-21. 23. Application of the pressure sensor according to any one of claims 1-13 and 22 in the field of wearable devices and/or human-computer interaction. 24. A wearable device, characterized in that the wearable device includes the pressure sensor according to any one of claims 1-13 and 22.