Multi-mode flexible sensor with pressure-proximity-magnetic field sensing function and preparation method thereof

Abstract

The invention provides a multimode flexible sensor with pressure-proximity-magnetic field sensing and a preparation method thereof, and belongs to the technical field of flexible sensors. According to the application, the mold containing the inclined columnar hole array is prepared, the magnetic suspension is poured into the mold, then the first fabric is placed at the top of the mold, the magnetic inclined micro-column array can be integrated on the front surface of the first fabric after the magnetic suspension is cured, and after the first conductive layer is loaded on the back surface of the first fabric, the magnetic inclined micro-column array is integrated on the back surface of the first fabric. The integrated fabric electrode can be prepared; the integrated fabric electrode and the second fabric electrode are assembled in a butt joint mode, the magnetic inclined micro-column array serves as a dielectric layer, and the high-performance multi-mode flexible sensor which is high in sensitivity and fast in response is formed. The multi-mode flexible sensor can realize continuous and uninterrupted interaction, output signals of proximity sensing, pressure sensing and magnetic field sensing are not overlapped and are easy to distinguish, and the multi-mode flexible sensor has a good application prospect in the fields of medical health detection, human-computer interaction, electronic skin and the like.

Description

Technical Field

[0001] This invention relates to the field of flexible sensor technology, specifically to a multimode flexible sensor with pressure-proximity-magnetic field sensing and its fabrication method. Background Technology

[0002] Human skin, composed of the epidermis, dermis, and subcutaneous tissue, forms our body's protective barrier. Hair grows from hair follicles, penetrates the epidermis, and transmits external physical signals to the brain via mechanoreceptors and sensory nerves. Inspired by this, scientists have developed flexible tactile sensors that mimic the tactile sensation of human skin, converting external stimuli such as pressure, bending, and stretching into electrical signals. These sensors have wide applications in health monitoring, smart healthcare, intelligent prosthetics, bionic robots, and augmented reality.

[0003] Sensors operate in two main ways: contact and non-contact. Contact sensors acquire real-time physiological monitoring data through direct physical contact, such as pressing or stretching. Non-contact sensors, on the other hand, detect environmental signals, such as electromagnetic fields, temperature changes, or the proximity of objects, and convert these signals into electrical signals, enabling interaction without physical contact. This is particularly important for preventing the spread of viruses. Therefore, developing multimodal flexible sensors capable of simultaneously sensing pressure and proximity signals is crucial for building intuitive and scalable human-computer interaction platforms. With increasing demands for wearability, precise control, and versatility, the development of such sensors has become especially urgent.

[0004] In the prior art, patent CN107036657A discloses a method for fabricating a magnetic and force-induced ciliary bionic sensor. This patent involves placing a suspension of resin material and magnetic particles in a magnetic field environment, heating it until the solvent evaporates and the resin solidifies to obtain a magnetic ciliary array; then coating the surface of the obtained magnetic ciliary array with graphene oxide, followed by chemical reduction treatment to obtain a magnetically conductive ciliary array; finally, using this magnetically conductive ciliary array as a signal-sensitive layer, combined with an electrode layer, it functions as a sensor that responds to magnetic and force signals. However, the resin substrates in the electrode layer and signal-sensitive layer of this patent are both non-breathable polymer materials, which may cause skin discomfort with prolonged wear, limiting the sensor's application. Furthermore, the magnetic cilia manufactured using the magnetic field induction method in this patent have irregular shapes, and the growth height, diameter, and angle are difficult to control precisely. The entire fabrication method is also quite cumbersome, affecting not only the consistency and repeatability of the sensor but also its sensing performance. In addition, the sensor provided by this patent can only sense pressure and magnetic fields, not proximity signals, making it difficult to meet the development needs of multi-mode sensors.

[0005] In view of this, it is necessary to provide an improved multimode flexible sensor with pressure-proximity-magnetic field sensing and its fabrication method to solve the above problems. Summary of the Invention

[0006] In view of the technical problems existing in the background art, this application provides a multimode flexible sensor with pressure-proximity-magnetic field sensing and a method for its fabrication, aiming to solve the technical problems of traditional sensors having single function and poor sensing effect.

[0007] In a first aspect, embodiments of this application provide a method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing capabilities, comprising the following steps:

[0008] S1. Prepare a mold containing an array of inclined columnar holes;

[0009] S2. Mix magnetic particles and elastic polymer to prepare a magnetic suspension; pour the magnetic suspension into the mold, and place a first fabric on top of the mold so that the first fabric comes into contact with the magnetic suspension. After the magnetic suspension solidifies, demold to obtain a magnetic tilted micropillar array fabric.

[0010] S3. A first conductive layer is disposed on the back side of the magnetic tilted micropillar array fabric to obtain an integrated fabric electrode;

[0011] S4. A second conductive layer is formed on the front side of the second fabric to obtain a second fabric electrode; the integrated fabric electrode is assembled with the front side of the second fabric electrode to obtain a multimode flexible sensor with pressure-proximity-magnetic field sensing.

[0012] In the technical solution of this application embodiment, an integrated fabric electrode can be formed by integrating a magnetic tilted micropillar array on the front side of the first fabric and loading a first conductive layer on the back side of the first fabric. Based on this, by docking and assembling the integrated fabric electrode and the second fabric electrode, the magnetic tilted micropillar array can act as a dielectric layer, forming a high-sensitivity, fast-response, high-performance multimode flexible sensor. Under pressure, the magnetic tilted micropillars bend downwards; under a magnetic field, they stretch upwards. This differentiated response allows for high-precision sensing and differentiation of pressure and magnetic field changes. Furthermore, the irregular surface and edge electric field effect of the fabric electrode enable it to sense the approach of objects. Under pressure, the relative capacitance change is greater than zero; under a magnetic field, the relative capacitance change is less than zero; and when a finger approaches, the relative capacitance change is less than zero. However, the magnitude of the change with distance differs, allowing the sensor to distinguish between capacitance changes caused by finger approach and magnetic field stimulation. Benefiting from the deformability of the tilted magnetic micropillar dielectric layer, the edge electric field effect of the fabric electrode, and the magnetic response of the dielectric layer, a multimode flexible sensor integrating pressure, proximity, and magnetic field sensing is formed. The embodiments of this application not only improve the sensitivity and accuracy of the sensor, but also enhance its application potential in the field of multimodal sensing, and have broad and important application prospects in the field of flexible wearable multifunctional sensors.

[0013] In some embodiments, in step S1, the tilt angle of the columnar holes in the tilted columnar hole array relative to the vertical direction is 10 to 60°.

[0014] In this embodiment, the sensitivity of the sensor can be improved by adjusting the tilt angle of the columnar hole.

[0015] In some embodiments, the magnetic tilted micropillars in the magnetic tilted micropillar array fabric have a length of 2–3.5 mm, a diameter of 500–1000 μm, and a distribution density of 9–36 micropillars / cm². 2 .

[0016] In this embodiment, by adjusting the size of the magnetic tilted micropillar, it is possible to make it more sensitive to differentiated responses to pressure and magnetic field environments.

[0017] In some embodiments, in step S2, the mass ratio of the magnetic particles to the elastic polymer is 1 to 3:1.

[0018] In this embodiment, the sensitivity of the sensor can be improved by adjusting the ratio of magnetic particles to elastic polymer.

[0019] In some embodiments, the magnetic particles include one or more of neodymium iron boron particles, magnetic nickel particles, magnetic carbonyl iron particles, and iron oxide particles.

[0020] In some embodiments, the elastic polymer includes one or more of polydimethylsiloxane, polydiethylsiloxane, polyurethane acrylate, and silicone rubber.

[0021] In some embodiments, the first fabric and the second fabric are woven fabrics or nonwoven fabrics; the woven fabrics include one of PET fabrics, spandex fabrics, nylon fabrics, cotton fabrics, nylon fabrics, and linen.

[0022] In some embodiments, the first conductive layer and the second conductive layer are formed by drying conductive silver paste; the conductive silver paste is loaded by printing or coating.

[0023] In some embodiments, when assembling a multimode flexible sensor, the first conductive layer and the second conductive layer are respectively connected to wires.

[0024] In the above embodiments, the required raw materials are widely available, the preparation process is simple, and it is easy to mass-produce. It is possible to produce multimode flexible sensors with good repeatability, low power consumption, high sensitivity and pressure-proximity-magnetic field sensing at a low cost.

[0025] Secondly, embodiments of this application provide a multimode flexible sensor with pressure-proximity-magnetic field sensing. The multimode flexible sensor is prepared using the above-described preparation method and includes an integrated fabric electrode and a second fabric electrode disposed opposite to each other. The integrated fabric electrode includes a first fabric, a magnetic tilted micropillar array disposed on one side of the first fabric, and a conductive layer disposed on the other side of the first fabric. The magnetic tilted micropillar array acts as a dielectric layer between the first fabric and the second fabric electrode.

[0026] In the technical solution of this application embodiment, by cleverly designing the structure of the multimode flexible sensor, the first fabric, the conductive layer, and the magnetic tilted micropillar array together constitute an integrated fabric electrode. This not only enables proximity sensing by utilizing the irregular surface and edge electric field effect of the fabric electrode, but also allows the magnetic tilted micropillar array to act as a dielectric layer, optimizing the electrode-dielectric layer interface coupling and shortening the sensor's response time. The multimode flexible sensor with pressure-proximity-magnetic field sensing provided by this application can achieve continuous and uninterrupted interaction, and the output signals of proximity sensing, pressure sensing, and magnetic field sensing do not overlap and are easy to distinguish. It has good application prospects in fields such as medical and health monitoring, human-computer interaction, and electronic skin.

[0027] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of a multimode flexible sensor with pressure-proximity-magnetic field sensing in an embodiment of this application;

[0030] Figure 2 This is a proximity sensing test data graph of the multimode flexible sensor prepared in Example 1 of this application;

[0031] Figure 3 This is a graph showing the pressure response and recovery time data of the multimode flexible sensor prepared in Example 1 of this application;

[0032] Figure 4 This is a graph showing the magnetic field response and recovery time data of the multimode flexible sensor prepared in Example 1 of this application;

[0033] Figure 5 The graph shows the pressure sensing sensitivity data of the multimode flexible sensors prepared in Example 1 and Comparative Example 1 of this application.

[0034] Figure 6 This is a graph showing the magnetic field sensing sensitivity data of the multimode flexible sensors prepared in Example 1 and Comparative Example 1 of this application;

[0035] Figure 7 This is a graph showing the pressure response and recovery time data of the sensor prepared in Comparative Example 2 of this application;

[0036] Figure 8 This is a graph showing the magnetic field response and recovery time data of the sensor prepared in Comparative Example 2 of this application;

[0037] Figure 9 This is a proximity sensing test data graph of the sensor prepared in Comparative Example 2 of this application. Detailed Implementation

[0038] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0040] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0041] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0042] To address the technical problems of existing sensors, such as limited functionality, poor sensing performance, and inability to accurately distinguish and sense pressure, proximity, and magnetic field changes, this application provides a method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing capabilities, comprising the following steps:

[0043] S1. Prepare a mold containing an array of inclined columnar holes;

[0044] S2. Mix magnetic particles and elastic polymer to prepare a magnetic suspension; pour the magnetic suspension into the mold, and place a first fabric on top of the mold so that the first fabric comes into contact with the magnetic suspension. After the magnetic suspension solidifies, demold to obtain a magnetic tilted micropillar array fabric.

[0045] S3. A first conductive layer is disposed on the back side of the magnetic tilted micropillar array fabric to obtain an integrated fabric electrode;

[0046] S4. A second conductive layer is formed on the front side of the second fabric to obtain a second fabric electrode; the integrated fabric electrode is assembled with the front side of the second fabric electrode to obtain a multimode flexible sensor with pressure-proximity-magnetic field sensing.

[0047] Through the above method, this embodiment integrates a magnetic tilted micropillar array on the front side of the first fabric and loads a first conductive layer on the back side of the first fabric, forming an integrated fabric electrode. Based on this, by docking and assembling the integrated fabric electrode and the second fabric electrode, the magnetic tilted micropillar array can act as a dielectric layer, forming a high-sensitivity, fast-response, high-performance flexible sensor. Under pressure, the magnetic tilted micropillars bend downwards; under a magnetic field, they stretch upwards. This differentiated response allows for high-precision sensing and differentiation of pressure and magnetic field changes. Furthermore, the irregular surface and edge electric field effect of the fabric electrode enable it to sense the proximity of objects, thus forming a multimode flexible sensor integrating pressure, proximity, and magnetic field sensing. This embodiment not only improves the sensitivity and accuracy of the sensor but also enhances its application potential in the field of multimodal sensing, showing broad and significant application prospects in the field of flexible wearable multifunctional sensors.

[0048] Furthermore, in some embodiments, in step S1, the tilt angle of the columnar holes in the tilted columnar hole array relative to the vertical direction is preferably 10 to 60°. By adjusting the tilt angle of the columnar holes to this range, the sensitivity of the sensor can be improved.

[0049] Furthermore, in some embodiments, the magnetic tilted micropillars in the magnetic tilted micropillar array fabric have a length of 2–3.5 mm, a diameter of 500–1000 μm, and a distribution density of 9–36 micropillars / cm². 2 By adjusting the size and arrangement of the columnar holes in the mold, magnetic tilted micropillars of the required size can be obtained, enabling them to respond more sensitively to pressure and magnetic field environments.

[0050] Furthermore, in some embodiments, in step S2, the mass ratio of the magnetic particles to the elastic polymer is 1 to 3:1. By adjusting the ratio of the magnetic particles to the elastic polymer to this range, the sensitivity of the sensor can be improved.

[0051] The magnetic particles include one or more of neodymium iron boron particles, magnetic nickel particles, magnetic carbonyl iron particles, and iron oxide particles; the elastic polymer includes one or more of polydimethylsiloxane, polydiethylsiloxane, polyurethane acrylate, and silicone rubber.

[0052] Furthermore, both the first and second fabrics are woven or non-woven fabrics; the woven fabric is preferably one of PET fabric, spandex fabric, nylon fabric, cotton fabric, nylon fabric, or linen. This application, by using fabric as a substrate, can achieve proximity sensing functionality by utilizing the irregular surface and edge electric field effect of the fabric electrodes.

[0053] Furthermore, in some embodiments, the first conductive layer and the second conductive layer are formed by drying conductive silver paste; the conductive silver paste is loaded by printing or coating. When assembling a multimode flexible sensor, a multimode flexible sensor with pressure-proximity-magnetic field sensing can be obtained by connecting the first conductive layer and the second conductive layer to wires respectively.

[0054] In the above embodiments, the required raw materials are widely available, the preparation process is simple, and it is easy to mass-produce. It is possible to produce multimode flexible sensors with good repeatability, low power consumption, high sensitivity and pressure-proximity-magnetic field sensing at a low cost, which has good application prospects.

[0055] This application also provides a multimode flexible sensor with pressure-proximity-magnetic field sensing capabilities. This multimode flexible sensor is fabricated using the above-described method, and its structural schematic diagram is shown below. Figure 1 As shown, it includes an integrated fabric electrode and a second fabric electrode disposed opposite to each other; the integrated fabric electrode includes a first fabric, a magnetic tilted micropillar array disposed on one side of the first fabric, and a conductive layer disposed on the other side of the first fabric; the magnetic tilted micropillar array acts as a dielectric layer between the first fabric and the second fabric electrode.

[0056] In the technical solution of this application embodiment, by cleverly designing the structure of the multimode flexible sensor, the first fabric, the conductive layer, and the magnetic tilted micropillar array together constitute an integrated fabric electrode. This not only enables proximity sensing by utilizing the irregular surface and edge electric field effect of the fabric electrode, but also allows the magnetic tilted micropillar array to act as a dielectric layer, optimizing the electrode-dielectric layer interface coupling and shortening the sensor's response time. The multimode flexible sensor with pressure-proximity-magnetic field sensing provided by this application can achieve continuous and uninterrupted interaction, and the output signals of proximity sensing, pressure sensing, and magnetic field sensing do not overlap and are easy to distinguish. It has good application prospects in fields such as medical and health monitoring, human-computer interaction, and electronic skin.

[0057] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0058] Example 1

[0059] This embodiment provides a method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing capabilities, comprising the following steps:

[0060] S1. Fabrication of a mold containing an array of inclined columnar holes

[0061] An array of tilted cylindrical holes (tilt angle 15°, diameter 900 μm, length 2.5 mm, and density 36 holes / cm²) was cut from a 3 mm thick acrylic sheet using a laser cutter. 2 ).

[0062] S2. Fabrication of magnetic tilted micropillar array fabric

[0063] Magnetic particles (NdFeB neodymium iron boron particles with an average particle size of 5 mm) and the elastic polymer polydimethylsiloxane (prepolymer to curing agent mass ratio of 10:1) were added to n-hexane and stirred at 400 rpm for 10 min using a mechanical stirrer to obtain a magnetic suspension. The mass ratio of NdFeB particles to polydimethylsiloxane was 2:1, and the mass ratio of polydimethylsiloxane to n-hexane was 5:1.

[0064] The magnetic suspension was then poured into a mold, and a piece of PET twill fabric of the same size as the mold was placed on top of the mold, ensuring contact between the PET twill fabric and the magnetic suspension. The mold was then placed in a vacuum oven and dried at 70°C for 10 hours to solidify the magnetic suspension. During the solidification process, the PET twill fabric on top of the mold bonded to the magnetic tilted micropillars formed by the solidified magnetic suspension. After demolding, the magnetic tilted micropillar array fabric was obtained.

[0065] S3. Fabrication of integrated fabric electrode

[0066] Using the side of the magnetic tilted micropillar array fabric that carries the magnetic tilted micropillars as the front side, a layer of conductive silver paste is screen-printed onto the back side of the magnetic tilted micropillar array fabric. After placing it in a fume hood for 5 hours to allow the conductive silver paste to dry, a first conductive layer is formed on the back side of the magnetic tilted micropillar array fabric, resulting in an integrated fabric electrode. The shape of this integrated fabric electrode can be cut as needed.

[0067] S4. Fabrication of Multimode Flexible Sensors

[0068] Take another piece of PET twill fabric, and screen print a layer of conductive silver paste on one side of the PET twill fabric. After drying, a second conductive layer is formed on one side of the second fabric, resulting in a second fabric electrode. Using the side of the second fabric electrode with the second conductive layer as the front side, assemble the front side of the integrated fabric electrode with the front side of the second fabric electrode, so that the magnetic tilted micropillar array acts as the dielectric layer. Connect the first conductive layer and the second conductive layer to the wires respectively, thereby obtaining a multimode flexible sensor with pressure-proximity-magnetic field sensing.

[0069] The proximity sensing, pressure sensing, and magnetic field sensing performance of the multimode flexible sensor prepared in this embodiment were tested respectively, and the specific methods are as follows:

[0070] 1. Proximity sensor testing method

[0071] The sensor was fixed to the test bench, and an aluminum foil layer was placed between the sensor and the test bench as an isolation layer. Then, the copper wires leading from both ends of the sensor were connected to the electrodes of the Tonghui TH2638 high-speed precision capacitance meter. By adjusting the vertical distance between the object (such as a finger) and the sensor, the proximity between them was changed, and the high-speed precision capacitance meter recorded the changes in the sensor capacitance value in real time.

[0072] 2. Pressure Sensing Test Method

[0073] The sensor was fixed to a MARK-10ESM303 electric tensile and compressive strength measuring platform, and its two electrodes were connected to a Tonghui TH2638 high-speed precision capacitance meter via copper wires. Pressure was applied to the sensor using the measuring platform, and the capacitance change curve was recorded simultaneously.

[0074] 3. Magnetic field sensing test methods

[0075] A stable static magnetic field is provided by a magnetic gap formed by two NdFeB magnets with a surface magnetic pole strength of 400 mT. The sensor is fixed at a certain position in the center of the magnetic gap, and copper wires leading from the sensor's electrodes are connected to the two electrodes of a high-speed precision capacitance meter (Tonghui, TH2638). The magnetic field strength applied to the sensor is changed by moving the sensor's position within the magnetic gap. The capacitance change of the sensor under different magnetic field strengths is synchronously recorded by the high-speed precision capacitance meter. The strength of the entire magnetic field is calibrated using a high-precision handheld digital gaussmeter (CH-Hall Electronicdevices, TX-15).

[0076] The proximity sensing test data graphs, pressure response and recovery time data graphs, and magnetic field response and recovery time graphs obtained using the above methods are shown below. Figure 2 , Figure 3 , Figure 4 As shown.

[0077] Depend on Figure 2-4 It can be seen that the multimode flexible sensor provided in this application can respond quickly to proximity, pressure and magnetic field, and the output signals of proximity sensing, pressure sensing and magnetic field sensing do not overlap and are easy to distinguish.

[0078] Comparative Example 1

[0079] This comparative example provides a method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing. Compared with Example 1, the only difference is that the cylindrical hole in the mold is set vertically with an inclination angle of 0 relative to the vertical direction. The remaining steps are the same as in Example 1 and will not be repeated here.

[0080] The pressure sensing sensitivity and magnetic field sensing sensitivity of the multimode flexible sensors prepared in Example 1 and Comparative Example 1 were tested, and the results are as follows: Figure 5 , Figure 6 As shown. By Figure 5-6 It can be seen that the pressure sensing sensitivity and magnetic field sensing sensitivity of the multimode flexible sensor prepared in Example 1 are both higher than those of Comparative Example 1, indicating that tilting the magnetic micropillar array in this application can significantly improve the sensitivity of the sensor.

[0081] Comparative Example 2

[0082] This comparative example provides a method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing. Compared with Example 1, the only difference is that the PET twill fabric used in steps S2 and S4 is replaced with a polyvinyl chloride film. The remaining steps are the same as in Example 1 and will not be repeated here.

[0083] The sensor prepared in this comparative example was tested, and its proximity sensing performance and response time results are as follows: Figure 7-9 As shown.

[0084] The results above demonstrate that the enhanced edge electric field effect of the fabric electrode provided by this invention endows the flexible multimode sensor with a sensitive response to proximity, significantly increasing the sensor's sensing dimensions. Simultaneously, the excellent interface coupling and superior mechanical compliance of the integrated fabric electrode give the flexible multimode sensor a faster response time to pressure and magnetic fields.

[0085] Examples 2-3 and Comparative Example 3

[0086] Examples 2-3 and Comparative Example 3 respectively provide a method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing. Compared with Example 1, the only difference is that the tilt angle of the cylindrical hole in the mold is changed. The other steps are the same as in Example 1 and will not be repeated here. The tilt angles in Examples 2-3 and Comparative Example 2 and the sensitivity of the resulting multimode flexible sensors are shown in Table 1.

[0087] Table 1 shows the tilt angle and sensor sensitivity in Examples 2-3 and Comparative Example 3.

[0088]

[0089] As can be seen from Table 1, by adjusting the tilt angle of the magnetic micropillars, the sensitivity of the sensor for pressure sensing and magnetic field sensing can be effectively controlled.

[0090] Examples 4-5 and Comparative Examples 4-5

[0091] Examples 4-5 and Comparative Examples 4-5 respectively provide a method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing. Compared with Example 1, the only difference is the change in the mass ratio of magnetic particles and elastic polymer. The remaining steps are the same as in Example 1 and will not be repeated here. The mass ratios in Examples 4-5 and Comparative Examples 3-4 and the sensitivity of the resulting multimode flexible sensors are shown in Table 2.

[0092] Table 2 shows the mass ratios and sensor sensitivities in Examples 4-5 and Comparative Examples 4-5.

[0093]

[0094]

[0095] As can be seen from Table 2, adjusting the mass ratio of magnetic particles to elastic polymer can effectively regulate the sensitivity of the sensor for pressure sensing and magnetic field sensing.

[0096] In summary, this application provides a multimode flexible sensor with pressure-proximity-magnetic field sensing and its fabrication method, belonging to the field of flexible sensor technology. This application involves preparing a mold containing an array of tilted columnar holes, pouring a magnetic suspension into the mold, placing a first fabric on top of the mold, and integrating the magnetic tilted micropillar array on the front side of the first fabric after the magnetic suspension has solidified. After loading a first conductive layer on the back side of the first fabric, an integrated fabric electrode is obtained. By assembling the integrated fabric electrode with a second fabric electrode, the magnetic tilted micropillar array acts as a dielectric layer, forming a high-sensitivity, fast-response, high-performance multimode flexible sensor. This multimode flexible sensor can achieve continuous and uninterrupted interaction, and the output signals for proximity sensing, pressure sensing, and magnetic field sensing do not overlap and are easily distinguishable, showing promising application prospects in medical and health monitoring, human-computer interaction, and electronic skin.

[0097] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing, characterized in that, Includes the following steps: S1. Prepare a mold containing an array of inclined columnar holes; S2. Mix magnetic particles and elastic polymer to prepare a magnetic suspension; pour the magnetic suspension into the mold, and place a first fabric on top of the mold so that the first fabric comes into contact with the magnetic suspension. After the magnetic suspension solidifies, demold to obtain a magnetic tilted micropillar array fabric. S3. A first conductive layer is disposed on the back side of the magnetic tilted micropillar array fabric to obtain an integrated fabric electrode; S4. A second conductive layer is formed on the front side of the second fabric to obtain a second fabric electrode; the integrated fabric electrode is assembled with the front side of the second fabric electrode to obtain a multimode flexible sensor with pressure-proximity-magnetic field sensing.

2. The method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing according to claim 1, characterized in that, In step S1, the tilt angle of the columnar holes in the inclined columnar hole array relative to the vertical direction is 10 to 60°.

3. The method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing according to claim 1, characterized in that, The magnetic tilted micropillars in the magnetic tilted micropillar array fabric have a length of 2–3.5 mm, a diameter of 500–1000 μm, and a distribution density of 9–36 micropillars / cm. 2 .

4. The method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing according to claim 1, characterized in that, In step S2, the mass ratio of the magnetic particles to the elastic polymer is 1 to 3:

1.

5. The method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing according to claim 1, characterized in that, The magnetic particles include one or more of neodymium iron boron particles, magnetic nickel particles, magnetic carbonyl iron particles, and iron tetroxide particles.

6. The method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing according to claim 1, characterized in that, The elastic polymer includes one or more of polydimethylsiloxane, polydiethylsiloxane, polyurethane acrylate, and silicone rubber.

7. The method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing according to claim 1, characterized in that, The first fabric and the second fabric are woven fabrics or non-woven fabrics; the woven fabrics include one of PET fabrics, spandex fabrics, nylon fabrics, cotton fabrics, nylon fabrics, and linen.

8. The method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing according to claim 1, characterized in that, The first conductive layer and the second conductive layer are formed by drying conductive silver paste; the conductive silver paste is loaded by printing or coating.

9. The method for fabricating a multimode flexible sensor with pressure-proximity-magnetic field sensing according to claim 1, characterized in that, When assembling a multimode flexible sensor, the first conductive layer and the second conductive layer are respectively connected to wires.

10. A multimode flexible sensor with pressure-proximity-magnetic field sensing, characterized in that, The material is prepared by any one of claims 1 to 9, comprising an integrated fabric electrode and a second fabric electrode disposed opposite to each other; the integrated fabric electrode comprises a first fabric, a magnetic tilted micropillar array disposed on one side of the first fabric, and a conductive layer disposed on the other side of the first fabric; the magnetic tilted micropillar array serves as a dielectric layer between the first fabric and the second fabric electrode.

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