A flexible near-field communication antenna and its preparation method

Abstract

The present invention discloses a flexible and elastic near-field communication antenna, comprising an antenna coil, wherein the antenna coil is formed by spirally winding a wire on the same plane, and two adjacent turns of wire are arranged at intervals, and the wire is formed by connecting a plurality of circular arcs connected end to end, and the number of circular arcs on the two adjacent turns of wire is the same, and the curvature of the circular arcs is the same. The present invention also discloses a method for preparing the flexible and elastic near-field communication antenna. Compared with the prior art, the flexible and elastic near-field communication antenna of the present invention adopts a specific structure with excellent resilience, and has good anti-deformation ability. It can still work normally after being subjected to arbitrarily bending, twisting, folding, curling, and extrusion.

Description

Technical Field

[0001] The present invention relates to the field of flexible and elastic electronics and communication technologies, and in particular to a flexible and elastic near-field communication antenna and a preparation method thereof. Background Art

[0002] In recent years, flexible and elastic electronic devices have attracted extensive research attention due to the difficulty of traditional planar electronic devices to adapt to complex and changing environments. Flexible and elastic electronic devices have the advantages of being stretchable, bendable, and able to conform to arbitrary surfaces, and have important application prospects in smart healthcare, health monitoring, and intelligent robotics. However, currently, flexible and elastic electronic devices mainly rely on active, wired information transmission, which greatly limits their application.

[0003] Near-field communication (NFC) is an important type of wireless communication. It mainly operates at a resonant frequency of 13.56 MHz and combines contactless radio frequency identification (RFID) technology with wireless interconnection technology to achieve the transformation of equipment from wired to wireless and active to passive. The most core component is the antenna used to transmit and receive electromagnetic waves. The antenna obtains energy through the principle of magnetic field coupling, which can achieve both energy supply and data transmission. The research on flexible NFC antennas mainly uses conductive materials such as copper metal, textile conductive yarn, carbon nanomaterials, and conductive ink. The structure mainly includes 2D serpentine structures and traditional coil winding. The stretching range of these antennas is mainly between 15% and 100%, and there are problems such as poor conductivity or structural fracture during the stretching process.

[0004] Therefore, it is of great significance to develop flexible elastic near-field communication antennas with a larger stretching range and anti-deformation function. Summary of the Invention

[0005] The object of the present invention is to provide a flexible near-field communication antenna, which has good anti-deformation ability and can still work normally after being arbitrarily bent, twisted, folded, curled, or squeezed.

[0006] The present invention provides a flexible near-field communication antenna, comprising an antenna coil. The antenna coil is formed by spirally winding a wire on the same plane, with two adjacent turns of wire spaced apart. The wire is formed by connecting a plurality of circular arcs connected end to end. The circular arcs on two adjacent turns of wire correspond to each other, so that the antenna coil has a spider-web shape.

[0007] The present invention adopts a spider web shape. In real life, when the spider web is subjected to external impact force, it can absorb part of the impact load and maintain the stability of the web surface. The spider web has the functions of tuned vibration damping and impact protection, can absorb part of the external impact load and maintain structural stability.

[0008] Preferably, each circle of the conductive wire of the antenna coil includes at least 6 arc lines, the centers of the arc lines face the outside of the antenna coil, and the curvature of the arc lines is 15-60°.

[0009] Preferably, the wire is made of a conductive material and a polymer material by surface deposition, and the surface deposition method is selected from a template method, a microfluidic method, and a 3D printing method.

[0010] Preferably, the conductive material comprises liquid metal, and the liquid metal is selected from at least one of gallium, gallium-indium alloy, and gallium-indium-tin alloy.

[0011] Preferably, the conductive material further includes an auxiliary conductive material, and the auxiliary conductive material is selected from at least one of iron-based, cobalt-based, nickel-based, copper-based, silver-based single or multiple metals, amorphous soft magnetic alloys, carbon nanotubes, graphite, and graphene.

[0012] Preferably, the polymer material is selected from at least one of polydimethylsiloxane, polyurethane, aliphatic aromatic random copolyester, AB silica gel, and silicone weather-resistant adhesive.

[0013] Preferably, the flexible near-field communication antenna further comprises:

[0014] a substrate, on which the antenna coil is fixedly arranged;

[0015] a first electrode, one end of the first electrode being electrically connected to one end of the antenna coil;

[0016] a second electrode, one end of the second electrode being electrically connected to the other end of the antenna coil;

[0017] An electrical component is fixedly arranged on the substrate, and the other end of the first electrode is electrically connected to the other end of the second electrode through the electrical component.

[0018] Preferably, the material of the substrate is selected from at least one of cloth-based materials, paper-based materials, PI film, plastic film, PET film, PVA, PDMS, silicone, Ecoflex, skin, SBS elastomer, POE elastomer, rubber, resin, hydrogel, polyurethane, styrene block copolymer, PVC, polyimide, polyethylene terephthalate plastic, polyethylene octene co-elastomer, and thermoplastic elastomer.

[0019] Preferably, the material of the first electrode and the second electrode is selected from one of gold, platinum, silver, copper, and oxidized gallium-based liquid metal, and the electrical component is selected from capacitors and / or resistors.

[0020] Another object of the present invention is to provide a method for preparing a flexible near-field communication antenna, the method comprising the following steps:

[0021] S1. Setting a shape arrangement of the antenna coil, and manufacturing the antenna coil according to the set shape arrangement;

[0022] S2. Fixing the antenna coil prepared in step S1 on a substrate, measuring the inductance of the antenna coil and performing circuit matching, and selecting matching electrical components based on the circuit matching results;

[0023] S3. Electrically connect one end of the first electrode to one end of the antenna coil, one end of the second electrode to the other end of the antenna coil, and the other end of the first electrode to the other end of the second electrode via the matching electrical components selected in step S2.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] First, the antenna coil of the flexible near-field communication antenna of the present invention adopts a specific structure with excellent resilience and good deformation resistance. It can still work normally after being bent, twisted, folded, curled, or squeezed at will.

[0026] Secondly, the flexible near-field communication antenna produced by the present invention has good flexibility and stretchability, can conform to curved surfaces, fit well on the surface of human skin, and can withstand tensile deformation exceeding 700%;

[0027] Third, the flexible near-field communication antenna produced by the present invention has good robustness and can still work stably after being arbitrarily bent, twisted, folded, curled, and squeezed. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic structural diagram of a flexible near-field communication antenna manufactured according to an embodiment of the present invention;

[0029] Figure 2 is a graph showing the relationship between the stretching degree and the inductance of the flexible near-field communication antenna manufactured according to an embodiment of the present invention;

[0030] Figure 3 Graph showing the relationship between different stretching degrees, frequency, and loss of the flexible near-field communication antenna manufactured in an embodiment of the present invention;

[0031] Figure 4 FIG. 4 is a relationship diagram between frequency and cycle number of the flexible elastic near-field communication antenna manufactured in an embodiment of the present invention when the stretching degree is 100%.

[0032] Description of reference numerals:

[0033] 1-antenna coil; 2-substrate; 3-first electrode; 4-second electrode; 5-electrical component; 6-insulating layer. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] Example

[0036] like Figure 1 As shown, a flexible near-field communication antenna includes an antenna coil 1, a substrate 2, a first electrode 3, a second electrode 4 and an electrical component 5. The antenna coil 1 is formed by spirally winding a wire on the same plane, and two adjacent turns of wire are arranged at intervals. The wire is formed by connecting a number of circular arcs connected end to end, and the center of the circular arc is toward the outside of the antenna coil 1. The number of circular arcs on the two adjacent turns of wire is the same, both 8, and the curvature of the circular arc is the same, both 45°. The antenna coil 1 is fixedly set on the substrate 2, one end of the first electrode 3 is electrically connected to one end of the antenna coil 1, and one end of the second electrode 3 is electrically connected to the other end of the antenna coil 1. The electrical component 5 is fixedly set on the substrate 2, and the other end of the first electrode 3 is electrically connected to the other end of the second electrode 3 through the electrical component 5.

[0037] The preparation method of the flexible near-field communication antenna in this embodiment is as follows:

[0038] Use the slicing software to set up the required circuit model in advance. In this embodiment, the antenna coil 1 is made of conductive material and polymer material by 3D printing. The conductive material comprises liquid metal and auxiliary conductive material, and the liquid metal is gallium indium tin alloy, the auxiliary conductive material is selected from amorphous soft magnetic alloy, and the polymer material is polydimethylsiloxane. The printing parameters are set to include the extrusion needle thickness of 14G to 32G, the printing speed is set to 5mm / s-60mm / s according to the viscosity of the printing slurry, the extrusion volume is usually set to 100%, the extrusion pressure is 100Kpa to 400Kpa, the printing slurry is placed in the barrel, and the point is pressed. Click to start printing. The slurry is evenly extruded along the set antenna structure model path to obtain the antenna coil 1. Next, the antenna coil 1 is fixed on the substrate 2, the material of the substrate 2 is polyethylene octene co-elastomer. Then, the inductance of the antenna coil 1 is measured and the circuit is matched. The electrical component 5 is selected based on the circuit matching result. In this embodiment, the electrical component 5 is a capacitor. One end of the first electrode 3 and one end of the second electrode 4 are respectively led out from the two ends of the antenna coil 1. In this embodiment, the material of the first electrode 3 and the second electrode 4 is oxidized gallium-based liquid metal. The other end of the first electrode 3 and the other end of the second electrode 4 are electrically connected through a capacitor.

[0039] In the above embodiment, an insulating layer 6 is fixedly provided on the wire body of the antenna coil 1 to prevent a short circuit problem caused by contact between the first electrode 3 , the second electrode 4 and the wire body of the antenna coil 1 .

[0040] The flexible near-field communication antenna prepared in this embodiment was placed on a stretching machine for a stretching test (0-700%), and multiple action tests were performed using a folding tool (0-180°), a bending tool (1-5mm), a curling tool (0-1.25 turns), and a twisting tool (0-270°). All of these tests showed that the antenna could operate stably near a frequency of 13.56 MHz. The test results are shown in FIG. Figure 2 、 Figure 3 and Figure 4 .

[0041] In other embodiments, the antenna coil 1 is made of a conductive material and a polymer material by surface deposition, and the surface deposition method can be a template method or a microfluidic method.

[0042] In other embodiments, the conductive material is composed of liquid metal, and the liquid metal is selected from at least one of gallium, gallium-indium alloy, and gallium-indium-tin alloy.

[0043] In other embodiments, the conductive material is composed of liquid metal and auxiliary conductive material, and the auxiliary conductive material is selected from at least one of iron-based, cobalt-based, nickel-based, copper-based, silver-based single or multiple metals, carbon nanotubes, graphite, and graphene.

[0044] In other embodiments, the polymer material is selected from at least one of polyurethane, aliphatic aromatic random copolyester, AB silicone, and silicone weather-resistant adhesive.

[0045] In other embodiments, the material of the substrate 2 can be selected from at least one of cloth-based materials, paper-based materials, PI films, plastic films, PET films, PVA, PDMS, silicone, Ecoflex, skin, SBS elastomers, POE elastomers, rubber, resins, hydrogels, polyurethanes, styrene block copolymers, PVC, polyimides, polyterephthalate plastics, and thermoplastic elastomers.

[0046] In other embodiments, the material of the first electrode 3 and the second electrode 4 may be selected from one of gold, platinum, silver, and copper.

[0047] In other embodiments, the electrical component 5 may be a resistor.

[0048] The above examples utilize readily available raw materials, low production costs, environmental friendliness, and high utilization rates. The use of 3D direct-write printing technology significantly improves the resolution of the flexible near-field communication antenna, while the lossless creation of a liquid metal flexible near-field communication antenna coil ensures excellent stretchability and high conductivity. Leveraging the unique structural characteristics of the flexible near-field communication antenna, the innovative application of this technology to the flexible near-field communication antenna results in superelasticity, deformation resistance, and multi-directional stretchability. This technology holds great potential for applications in information exchange, wearable devices, implantable devices, and other applications for monitoring animal, plant, and human data.

[0049] Although the present disclosure is disclosed as above, the protection scope of the present disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A flexible near-field communication antenna, characterized by: The invention comprises an antenna coil (1), wherein the antenna coil (1) is formed by spirally winding a wire on the same plane, and two adjacent turns of the wire are arranged at intervals, the wire is formed by connecting a plurality of circular arcs connected end to end, and the circular arcs on the two adjacent turns of the wire correspond to each other so that the antenna coil (1) is in a spider web shape, the wire is made of a conductive material and a polymer material by surface deposition, and the surface deposition method is selected from one of a template method, a microfluidic method, and a 3D printing method, the conductive material includes liquid metal, and the liquid metal is selected from at least one of gallium, a gallium-indium alloy, and a gallium-indium-tin alloy, and the polymer material is selected from at least one of polydimethylsiloxane, polyurethane, aliphatic aromatic random copolyester, AB silicone, and silicone weathering adhesive; Also includes: a substrate (2), the antenna coil (1) being fixedly arranged on the substrate (2); a first electrode (3), one end of the first electrode (3) being electrically connected to one end of the antenna coil (1); a second electrode (4), one end of the second electrode (4) being electrically connected to the other end of the antenna coil (1); An electrical component (5) is fixedly arranged on the substrate (2), and the other end of the first electrode (3) and the other end of the second electrode (4) are electrically connected via the electrical component (5).

2. The flexible near-field communication antenna according to claim 1, wherein: Each circle of the conductive wire of the antenna coil (1) comprises at least 6 arc lines, the centers of the arc lines face the outside of the antenna coil (1), and the arc angle of the arc lines is 15-60°.

3. The flexible near-field communication antenna according to claim 1, wherein: The conductive material also includes an auxiliary conductive material, and the auxiliary conductive material is selected from at least one of iron-based, cobalt-based, nickel-based, copper-based, silver-based single or multiple metals, amorphous soft magnetic alloys, carbon nanotubes, graphite, and graphene.

4. The flexible near-field communication antenna according to claim 1, wherein: The material of the substrate (2) is selected from at least one of cloth-based materials, paper-based materials, PI films, plastic films, PET films, PVA, PDMS, silicone, Ecoflex, skin, SBS elastomers, POE elastomers, rubber, resins, hydrogels, polyurethanes, styrene block copolymers, PVC, polyimides, polyterephthalate plastics, polyethylene octene copolymers, and thermoplastic elastomers.

5. The flexible near-field communication antenna according to claim 1, wherein: The materials of the first electrode (3) and the second electrode (4) are selected from one of gold, platinum, silver, copper, and oxidized gallium-based liquid metal, and the electrical component (6) is selected from a capacitor and / or a resistor.

6. A method for preparing the flexible near-field communication antenna according to claim 1, characterized in that: The preparation method specifically comprises the following steps: S1. Setting the shape and arrangement of the antenna coil (1), and manufacturing the antenna coil (1) according to the set shape and arrangement; S2, fixing the antenna coil (1) obtained in step S1 on the substrate (2), measuring the inductance of the antenna coil (1) and performing circuit matching, and selecting a matching electrical component (6) based on the circuit matching result; S3. Electrically connect one end of the first electrode (3) to one end of the antenna coil (1), electrically connect one end of the second electrode (4) to the other end of the antenna coil (1), and electrically connect the other end of the first electrode (3) to the other end of the second electrode (4) via the matching electrical component (6) selected in step S2.

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