CN114383761A - Pressure sensor with single-direction conductive function, preparation method and application thereof - Google Patents

Abstract

The invention relates to the technical field of sensors, and particularly discloses a pressure sensor with a single-direction conducting function, and a preparation method and application thereof. The pressure sensor includes: the flexible electrode structure comprises two layers of flexible electrodes and a dielectric layer positioned between the two layers of flexible electrodes; the dielectric layer comprises a base material and magnetic conductive fibers distributed in the base material, and the magnetic conductive fibers are arranged in a direction perpendicular to the flexible electrodes. The pressure sensor provided by the invention has the advantages of flexibility, high sensitivity and wide monitoring range.

Description

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

technical field

The invention relates to the technical field of sensors, in particular to a pressure sensor with a single-direction conduction function, a preparation method and application thereof.

Background technique

The accurate use of electronic sensors to measure important human information in real time plays an important role in health monitoring and medical care. Human skin can naturally distinguish pressure and various mechanical stimuli or mechanical deformation and conduct independent sensing. Therefore, wearable electronic sensor devices should also have the ability to Capable of highly sensitive perception of various mechanical stresses. However, most of the current sensors rely on the change of contact resistance to realize pressure sensing, and their deformation range is small, which cannot achieve high sensitivity and wide monitoring range.

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

SUMMARY OF THE INVENTION

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

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

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

The magnetic conductive fibers are oriented and distributed in the matrix material, and the flexible electrodes are assembled;

Wherein, the magnetic conductive fibers are oriented and arranged perpendicular 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 comprising the aforementioned pressure sensor.

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

Description of drawings

Fig. 1 is the schematic diagram of the magnetic conductive fiber after orientation arrangement of a specific embodiment of the present invention;

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

In Fig. 3, (a) is a graph showing the change of the ratio of real-time current to initial current with pressure changes for the sensors prepared in Example 1, Example 4 and Comparative Example 1 under different pressures; (b) respectively It is the graph of the change of the ratio of real-time current and initial current with pressure changes under different pressures of the sensors prepared in Example 1, Example 2 and Example 3 of the present invention; (c) is the pressure-free state, Example 1 The relationship between the current and the voltage of the prepared sensor at different voltages (volt-ampere curve); (d) is a curve diagram 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 the pressure sensor of a specific embodiment of the present invention at the same size and pressure and different frequencies; (f) is a sensor of a specific embodiment of the present invention (Example 1) under pressure stimulation, real-time current The change curve of ; (g) is the change curve of the real-time current of the sensor of a specific embodiment of the present invention (Example 1) under the same pressure stimulation for 3000 times.

Detailed ways

The endpoints of ranges and any values disclosed herein are not limited to the precise ranges or values, which are to be understood to encompass values proximate to those ranges or values. For ranges of values, the endpoints of each range, the endpoints of each range and the individual point values, and the individual point values can be combined with each other to yield one or more new ranges of values that Ranges should be considered as specifically disclosed herein.

A first aspect of the present invention provides a pressure sensor with a single-direction conductive function, the pressure sensor includes: two layers of flexible electrodes and a dielectric layer between the two layers of flexible electrodes; the dielectric layer includes a base material and distributed in Magnetic conductive fibers in the matrix 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 fibers may be (3-25):1 (eg 3:1, 4:1, 5:1, 10:1, 15:1, 20:1, 25:1, or any value in between).

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

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

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

The thickness of the dielectric layer is not particularly limited in the present invention, as long as it can meet the requirements of the present invention. For example, the thickness of the dielectric layer may be 2 mm-5 mm.

According to some embodiments of the present invention, the base material may be selected from thermally curable materials and/or photocurable 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. Wherein, the electrical insulation, weather resistance and shear resistance of the base material can be used for a long time at -50°C to 200°C.

According to some embodiments of the present invention, the thermally curable material may be selected from polydimethylsiloxane and/or silica gel.

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 each independently be 20 μm-70 μm.

According to some embodiments of the present invention, the flexible electrodes may be selected from interdigitated 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 the interdigital electrodes is 8-20 pairs.

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

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

According to a preferred embodiment of the present invention, the magnetron sputtering enables the thickness of the metal 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 electrodes are mesh electrodes; and the conductive metal electrodes are selected from at least one of copper electrodes, nickel cloth and silver cloth.

According to some embodiments of the present invention, the sensitivity of the pressure sensor may be 10000-40000 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 comprising the following steps:

The magnetic conductive fibers are oriented and distributed in the matrix material, and the flexible electrodes are assembled;

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

According to some embodiments of the present invention, the manner of assembling the flexible electrode includes: curing the flexible electrode and the matrix material distributed with the magnetic conductive fibers together;

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

Wherein, curing the flexible electrodes together with the matrix material distributed with the magnetic conductive fibers may mean that one or more flexible electrodes are cured together with the matrix material distributed with the magnetic conductive fibers.

According to some embodiments of the present invention, the manner in which the magnetic conductive fibers are oriented and distributed in the matrix material may be:

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 method of first covering the upper surface of the flexible electrode and then curing can reduce the contact resistance, facilitate the stabilization of the device, and at the same time 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 according to the second aspect of the present invention have the same meanings as those of the aforementioned first aspect. It will not be repeated here.

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

According to some embodiments of the present invention, the mixing is performed with stirring. The rotating speed of the stirring can be 1500-3000rpm, and the 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 strength is 0.1-0.3 T; and the magnetic field induction is performed under a uniform magnetic field.

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

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

Preferably, the thermal curing conditions include: 70-80° C. for 60-90 min.

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

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 in 3D printing, where a sample material with a specific pattern can be oriented to print.

A fifth aspect of the present invention provides a wearable device comprising the aforementioned pressure sensor.

The present invention will be described in detail below by means of examples.

Example 1

(1) Add 4g nickel-plated carbon fiber (diameter 0.2mm, length 2mm, conductivity 1.5×10-3Ω·cm, magnetic permeability 8×103H/m) into 16g base material (polydimethylsiloxane alkane (PDMS)), stir at 2000rpm for 20min, mix well and pour into a flat mold (material: acrylic (polymethyl methacrylate; 4cm (length) × 4cm (width) × 2mm (height)), the bottom of the mold The surface of the mixed nickel-plated carbon fiber and the base material is scraped (a thin blade is used to make a uniform film on the base material), and then the mold with the nickel-plated carbon fiber and the base material is installed. Placed in a vertical magnetic field, under the induction of a 0.2T magnetic field (uniform magnetic field), the nickel-plated carbon fibers in it are oriented and twisted along the direction of the 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, 4 cm (length) × 4 cm (width)) with a thickness of 50 μm, left standing at room temperature, and self-leveling for 10 min to obtain a dielectric layer precursor covered with a conductive film on the upper surface;

The obtained dielectric layer precursor is thermally cured at 70° C. for 60 minutes to obtain a dielectric layer with a conductive film covering the upper surface, wherein the thickness of the dielectric layer is 2 mm;

(2) The interdigital electrodes were prepared by magnetron sputtering (the time was 30 min), the thickness of the copper deposited on the interdigital electrodes was 100 nm, the thickness of the interdigital electrodes was 72 μm, and the interdigital line width and line spacing of the interdigital electrodes were respectively 150 μm; stick it as a lower electrode to the lower surface of the dielectric layer whose upper surface is covered with a conductive film.

Example 2

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

The obtained dielectric layer precursor is thermally cured at 70° C. for 60 minutes to obtain a dielectric layer with a conductive film covering the upper surface, wherein the thickness of the dielectric layer is 2 mm;

(2) The interdigital electrodes were prepared by magnetron sputtering (the time was 30 min), the thickness of the copper deposited on the interdigital electrodes was 100 nm, the thickness of the interdigital electrodes was 72 μm, and the interdigital line width and line spacing of the interdigital electrodes were respectively 150 μm; stick it as a lower electrode to the lower surface of the dielectric layer whose upper surface is covered with a conductive film.

Example 3

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

The obtained dielectric layer precursor is thermally cured at 70° C. for 60 minutes to obtain a dielectric layer with a conductive film covering the upper surface, wherein the thickness of the dielectric layer is 2 mm;

(2) The interdigital electrodes were prepared by magnetron sputtering (the time was 30 min), the thickness of the copper deposited on the interdigital electrodes was 100 nm, the thickness of the interdigital electrodes was 72 μm, and the interdigital line width and line spacing of the interdigital electrodes were respectively 150 μm; stick it as a lower electrode to the lower surface of the dielectric layer whose upper surface is covered with a conductive film.

Example 4

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

The obtained dielectric layer precursor is thermally cured at 70° C. for 60 minutes to obtain a dielectric layer with a conductive film covering the upper surface, wherein the thickness of the dielectric layer is 2 mm;

(2) The interdigital electrodes were prepared by magnetron sputtering (the time was 30 min), the thickness of the copper deposited on the interdigital electrodes was 100 nm, the thickness of the interdigital electrodes was 72 μm, and the interdigital line width and line spacing of the interdigital electrodes were respectively 150 μm; stick it as a lower electrode to the lower surface of the dielectric layer whose upper surface is covered with a conductive film.

Comparative Example 1

The method of Example 1 was carried out, except that the orientation induction of the nickel-plated carbon fibers was not performed with a magnetic field.

Test the effect of the pressure sensor obtained above:

(a) in Figure 3 is the use of linear motor to apply variable pressure to the pressure sensors prepared in Example 1, Example 4, and Comparative Example 1, wherein a digital source meter Keithley-2400 ( is used to apply a constant voltage , using the digital source meter Keithley-6517 to test the current. According to the test results, the ratio of the real-time current to the initial current increases with the increase of the applied pressure.

The test results of (a) in FIG. 3 show that the pressure sensors prepared in Example 1, Example 4 and Comparative Example 1 have good response to pressure.

The different curves and different slopes of (a) in FIG. 3 respectively show that the response of the pressure sensor prepared in Example 1 to pressure is much higher than that in Example 4 and Comparative Example 1.

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

The different curves and different slopes of (a) in FIG. 3 respectively indicate that the response of the pressure sensor prepared in Example 1 to pressure is much higher than that in Examples 2 and 3.

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

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

(d) in Figure 3 represents the current corresponding to the pressure sensor prepared in Example 1 under a specific applied pressure (1-100kPa, such as 1kPa, 15kPa, 38kPa, 48kPa, and 58kPa); the results show that the output current signal is in the same Stable under stressful stimulation and increased with increasing stress.

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

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

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

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

Claims (14)

1. A pressure sensor having a unidirectional electrical conduction function, the pressure sensor comprising: the flexible electrode structure comprises two layers of flexible electrodes and a dielectric layer positioned between the two layers of flexible electrodes; the dielectric layer comprises a base material and magnetic conductive fibers distributed in the base material, and the magnetic conductive fibers are arranged in a direction perpendicular to the flexible electrodes.

2. The pressure sensor of claim 1, wherein the weight ratio of the base material to the magnetic conductive fibers is (3-25): 1;

and/or the magnetic conductive fiber is cylindrical; preferably, the length of the magnetic conductive fiber is 0.5-3mm, and the diameter is 0.1-0.3 mm;

and/or the conductivity coefficient of the magnetic conductive fiber is (1.5-2) multiplied by 10^-3Omega cm; magnetic permeability of (8-9) × 10³H/m。

3. Pressure sensor according to claim 1 or 2, wherein the magnetic conductive fibers are selected from at least one of nickel-plated carbon fibers, nickel-plated metal fibers, nickel-plated stainless steel, iron-plated carbon fibers and cobalt-plated carbon fibers, preferably nickel-plated carbon fibers and/or cobalt-plated carbon fibers.

4. The pressure sensor of claim 1 or 2, wherein the dielectric layer has a thickness of 2mm-5 mm;

and/or, the substrate material is selected from a thermosetting material and/or a photo-curing material;

preferably, the thermosetting material is selected from polydimethylsiloxane and/or silica gel;

preferably, the light-curable material is a light-sensitive polyurethane.

5. The pressure sensor of claim 1 or 2, wherein the two layers of flexible electrodes each independently have a thickness of 20-70 μ ι η;

and/or the flexible electrode is selected from an interdigital electrode and/or a conductive metal electrode;

preferably, the upper electrode of the pressure sensor is a conductive metal electrode, and the lower electrode is an interdigital electrode;

preferably, the number of pairs of the interdigital electrodes is 8-20 pairs;

preferably, the line width and the line distance of the interdigital electrode are respectively and independently 100-200 μm;

preferably, the conductive metal electrode is a mesh electrode; the conductive metal electrode is selected from at least one of a copper electrode, a nickel cloth and a silver cloth.

6. The pressure sensor according to any of claims 1-5, wherein the sensitivity of the pressure sensor is 10000-40000kPa^-1。

7. A method of making a pressure sensor having a single-direction conductive function, the method comprising: the magnetic conductive fibers are directionally distributed in the base material, and the flexible electrode is assembled;

wherein the magnetic conductive fibers are aligned perpendicular to the flexible electrodes.

8. The method of claim 7, wherein assembling the flexible electrode comprises: curing the flexible electrode and the matrix material distributed with the magnetic conductive fibers together;

or after the matrix material distributed with the magnetic conductive fibers is solidified, the flexible electrode is adhered and covered.

9. The method of claim 7 or 8, wherein the magnetically conductive fibers are directionally distributed in the matrix material by:

and mixing the magnetic conductive fibers with the matrix material, and placing the mixture into a mold, wherein the conductive fibers are directionally distributed in the matrix material in a direction parallel to a magnetic field under the induction of the magnetic field perpendicular to the mold.

10. The method of claim 9, wherein the weight ratio of the base material to the magnetic, electrically conductive fibers is (5-20): 1;

and/or the magnetic conductive fiber is cylindrical; preferably, the length of the magnetic conductive fiber is 0.5-3mm, and the diameter is 0.1-0.3 mm;

and/or the conductivity coefficient of the magnetic conductive fiber is (1.5-2) multiplied by 10^-3Omega cm; magnetic permeability of (8-9) × 10³H/m；

And/or 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, preferably nickel-plated carbon fiber and/or cobalt-plated carbon fiber;

and/or, the substrate material is selected from a thermosetting material and/or a photo-curing material;

preferably, the thermosetting material is selected from polydimethylsiloxane and/or silica gel;

preferably, the light-curable material is a photosensitive polyurethane;

and/or, the mould is a flat mould; the bottom of the mold is made of abrasive paper;

and/or, the mixing is carried out under stirring; the stirring speed is 1500-3000rpm, and the time is 20-30 min;

and/or, the magnetic field-induced conditions comprise: the magnetic field intensity is 0.1-0.3T; the magnetic field induction is carried out under a uniform magnetic field;

and/or, the curing is photo-curing or thermal curing;

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

preferably, the conditions for the thermal curing include: at 70-80 deg.C for 60-90 min.

11. The method of any one of claims 7-10, wherein the flexible electrode has a thickness of 20 μ ι η to 70 μ ι η;

and/or the flexible electrode is selected from an interdigital electrode and/or a conductive metal electrode;

preferably, the upper electrode of the pressure sensor is a conductive metal electrode, and the lower electrode is an interdigital electrode;

preferably, the conductive metal electrode is a mesh electrode; the conductive metal electrode is selected from at least one of a copper electrode, a nickel cloth and a silver cloth;

preferably, the number of pairs of the interdigital electrodes is 8-20 pairs;

preferably, the line width and the line distance of the interdigital electrode are respectively and independently 100-200 μm;

preferably, the conductive metal electrode is a mesh electrode; the conductive metal electrode is selected from at least one of a copper electrode, a nickel cloth and a silver cloth;

preferably, the interdigital electrode is prepared by magnetron sputtering, wherein the magnetron sputtering time is 20-40min,

and/or the magnetron sputtering ensures that the thickness of the metal deposited on the interdigital electrode is 70-100 nm;

preferably, the deposited metal is selected from copper and/or gold, preferably copper.

12. A pressure sensor prepared by the method of any one of claims 7-11.

13. Use of a pressure sensor according to any of claims 1-6 and 12 in the field of wearable devices and/or human-computer interaction.

14. A wearable device, characterized in that it comprises a pressure sensor according to any of claims 1-6 and 12.

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