Capacitive-piezoelectric-pyroelectric sensor and preparation method thereof

Abstract

The present invention provides a capacitive-piezoelectric-pyroelectric sensor and a preparation method thereof, wherein the capacitive-piezoelectric-pyroelectric sensor comprises a first electrode layer, a capacitive-piezoelectric-pyroelectric layer and a second electrode layer, wherein the capacitive-piezoelectric-pyroelectric layer is located between the first electrode layer and the second electrode layer; the capacitive-piezoelectric-pyroelectric layer comprises a PVDF material, and when the capacitive-piezoelectric-pyroelectric layer is subjected to an external force, it will deform, and the two surfaces of the capacitive-piezoelectric-pyroelectric layer will generate charges of opposite polarity and equal magnitude, and the capacitance between the first electrode layer and the second electrode layer will change; when the capacitive-piezoelectric-pyroelectric layer is heated or cooled, a potential difference is generated on the two surfaces of the capacitive-piezoelectric-pyroelectric layer. The capacitive-piezoelectric-pyroelectric sensor provided by the present invention can detect static force and dynamic force at the same time, and can also detect pressure and temperature at the same time.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a capacitive-piezoelectric-pyroelectric sensor and a preparation method thereof. Background Art

[0002] With the rapid development of smart portable wearable terminals such as smart skin, automotive systems, biological monitoring equipment and soft robots in recent years, a variety of flexible pressure sensors have been widely studied for various potential applications. Traditional capacitive-based flexible pressure sensors are more suitable for static force detection because of the hysteresis of flexible materials, which leads to delays in the acquisition of capacitive signals.

[0003] Existing pressure sensors are generally based on a single sensing mechanism. For piezoresistors and piezoceramics, they can be used as sensors for static pressure sensing applications, and for triboelectric and piezoelectric sensors, they can be used as self-powered pressure sensors to detect dynamic pressure. However, it is difficult for a single sensor to detect dynamic and static forces at the same time. For sensor arrays, it is very difficult to measure displacement deformation, pressure, vibration and other signals in multiple modes with a single sensor array working under two different sensing models. Therefore, seeking a multi-parameter sensor that can detect static and dynamic forces and temperature and pressure at the same time has become a technical problem that needs to be solved urgently in this field. Summary of the invention

[0004] To solve the above technical problems, an embodiment of the present invention provides a capacitive-piezoelectric-pyroelectric sensor, comprising a first electrode layer, a capacitive-piezoelectric-pyroelectric layer and a second electrode layer, wherein the capacitive-piezoelectric-pyroelectric layer is located between the first electrode layer and the second electrode layer; the capacitive-piezoelectric-pyroelectric layer comprises a PVDF material, and when the capacitive-piezoelectric-pyroelectric layer is subjected to an external force, it will deform, and charges of opposite polarity and equal magnitude will be generated on the two surfaces of the capacitive-piezoelectric-pyroelectric layer, and the capacitance between the first electrode layer and the second electrode layer will change; when the capacitive-piezoelectric-pyroelectric layer is heated or cooled, a potential difference will be generated on the two surfaces of the capacitive-piezoelectric-pyroelectric layer.

[0005] Preferably, the first electrode layer includes a plurality of first electrodes distributed in parallel, the second electrode layer includes a plurality of second electrodes distributed in parallel, and the first electrodes are perpendicular to the second electrodes.

[0006] Preferably, the first electrode and the second electrode are both made of AgNS material.

[0007] Preferably, the capacitive-piezoelectric-pyroelectric sensor further includes a first protective layer and a second protective layer, wherein the first protective layer is located on an outer surface of the first electrode layer, and the second protective layer is located on an outer surface of the second electrode layer.

[0008] Preferably, the first protective layer and the second protective layer are both made of flexible insulating material.

[0009] Preferably, the flexible insulating material comprises PDMS material.

[0010] The present invention also provides a method for preparing a capacitive-piezoelectric-pyroelectric sensor, comprising the following steps:

[0011] providing a substrate;

[0012] forming a first protective layer on the substrate;

[0013] forming a first patterned first electrode layer on the first protective layer, wherein the first electrode layer comprises a plurality of first electrodes distributed in parallel;

[0014] Preparing a capacitive-piezoelectric-pyroelectric layer on the first electrode layer by using an electrospinning-hot pressing method;

[0015] forming a second patterned second electrode layer on the capacitive-piezoelectric-pyroelectric layer, wherein the second electrode layer comprises a plurality of second electrodes distributed in parallel, and the first electrodes are perpendicular to the second electrodes;

[0016] A second protective layer is formed on the second electrode layer.

[0017] Preferably, the forming of the first protective layer on the substrate comprises:

[0018] A flexible insulating solution is prepared, degassed, and then spin-coated on the substrate, and heated and cured to form the first protective layer.

[0019] Preferably, the flexible insulating solution is prepared by using PDMS prepolymer and a curing agent.

[0020] Preferably, the step of forming a first patterned first electrode layer on the first protective layer comprises:

[0021] A first mask is placed on the first protective layer, and a silver nanowire dispersion is sprayed onto the first protective layer. After the silver nanowire dispersion is solidified, the first mask is removed to obtain the first electrode layer.

[0022] Preferably, the method of preparing the capacitive-piezoelectric-pyroelectric layer on the first electrode layer by using an electrospinning-hot pressing method comprises:

[0023] Under stirring conditions in a water bath, PVDF powder is dissolved in DMF solvent to obtain PVDF spinning solution;

[0024] The PVDF spinning solution is placed in a syringe, and the syringe is placed on a spinning machine syringe pump for electrospinning to obtain a PVDF fiber film;

[0025] The PVDF fiber film is placed on the first electrode layer, and the capacitive-piezoelectric-pyroelectric layer is prepared by hot pressing.

[0026] Preferably, the second patterned second electrode layer is formed on the capacitive-piezoelectric-pyroelectric layer, comprising:

[0027] A second mask is placed on the capacitor-piezoelectric-pyroelectric layer, and a silver nanowire dispersion is sprayed on the capacitor-piezoelectric-pyroelectric layer. After the silver nanowire dispersion is cured, the second mask is removed to obtain the second electrode layer.

[0028] Preferably, the forming of the second protective layer on the second electrode layer comprises:

[0029] The flexible insulating solution is spin-coated on the second electrode layer, and after being heated and cured, the second protective layer is formed.

[0030] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0031] In the capacitive-piezoelectric-pyroelectric sensor provided by the present invention, the capacitive-piezoelectric-pyroelectric layer between the first electrode layer and the second electrode layer includes PVDF material (polyvinylidene fluoride, abbreviated as PVDF, is a highly non-reactive thermoplastic fluorine-containing polymer), which can be used as a dielectric material layer of the capacitive sensor, that is, when it is subjected to an external force, it will deform, so that the distance between the first electrode layer and the second electrode layer will change, thereby causing the capacitance to change; the capacitive-piezoelectric-pyroelectric layer can also be used as a piezoelectric material layer of the piezoelectric sensor, that is, when it is subjected to an external force, it will deform, so that charges of opposite polarity and equal magnitude will be generated on the two surfaces of the capacitive-piezoelectric-pyroelectric layer, and when the external force is removed, the capacitive-piezoelectric-pyroelectric layer returns to a non-charged state. Therefore, in the present invention, the responses of the capacitive sensor and the piezoelectric sensor are carried out simultaneously and do not interfere with each other, thereby solving the technical problem that it is difficult for the existing pressure sensor to detect dynamic force and static force at the same time, thereby achieving the purpose that the pressure sensor can detect static force and dynamic force at the same time. The capacitor-piezoelectric-pyroelectric layer can also be used as the pyroelectric material layer of the pyroelectric sensor. The two surfaces of the capacitor-piezoelectric-pyroelectric layer serve as electrodes. Due to the asymmetry of the PVDF molecular structure, it polarizes when the temperature changes. Therefore, when the capacitor-piezoelectric-pyroelectric layer is heated or cooled, its polarization degree changes, resulting in charge separation, thereby generating a potential difference, and then generating current, so that the sensor can detect pressure and temperature at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0033] Figure 1 A schematic diagram of the structure of a capacitive-piezoelectric-pyroelectric sensor provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. The terms "on" and "above" and any variations thereof are intended to describe positional relationships and do not represent a relationship of direct contact between the described objects.

[0036] As described in the background art, it is difficult for existing pressure sensors to detect dynamic force and static force simultaneously and to detect temperature and pressure simultaneously.

[0037] In order to solve the above problems, the present invention provides a capacitive-piezoelectric-pyroelectric sensor, comprising a first electrode layer 2, a capacitive-piezoelectric-pyroelectric layer 3 and a second electrode layer 4, wherein the capacitive-piezoelectric-pyroelectric layer 3 is located between the first electrode layer 2 and the second electrode layer 4; the capacitive-piezoelectric-pyroelectric layer 3 comprises a PVDF material, and when the capacitive-piezoelectric-pyroelectric layer 3 is subjected to an external force, it will deform, and charges of opposite polarity and equal magnitude will be generated on the two surfaces of the capacitive-piezoelectric-pyroelectric layer 3, and the capacitance between the first electrode layer 2 and the second electrode layer 4 will change; when the capacitive-piezoelectric-pyroelectric layer 3 is heated or cooled, a potential difference will be generated on the two surfaces of the capacitive-piezoelectric-pyroelectric layer 3.

[0038] In the capacitive-piezoelectric-pyroelectric sensor provided by the present invention, the capacitive-piezoelectric-pyroelectric layer 3 between the first electrode layer 2 and the second electrode layer 4 includes PVDF material (polyvinylidene fluoride, abbreviated as PVDF, is a highly non-reactive thermoplastic fluorine-containing polymer), which can be used as a dielectric material layer of the capacitive sensor, that is, when it is subjected to an external force, it will deform, so that the distance between the first electrode layer 2 and the second electrode layer 4 will change, so that the capacitance changes; the capacitive-piezoelectric-pyroelectric layer 3 can also be used as a piezoelectric material layer of the piezoelectric sensor, that is, when it is subjected to an external force, it will deform, so that charges of opposite polarity and equal magnitude will be generated on the two surfaces of the capacitive-piezoelectric-pyroelectric layer 3, and when the external force is removed, the capacitive-piezoelectric-pyroelectric layer 3 returns to a non-charged state. Therefore, in the present invention, the responses of the capacitive sensor and the piezoelectric sensor are carried out simultaneously and do not interfere with each other, thereby solving the technical problem that it is difficult for the existing pressure sensor to detect dynamic force and static force at the same time, thereby achieving the purpose of the pressure sensor being able to detect static force and dynamic force at the same time. The capacitor-piezoelectric-pyroelectric layer 3 can also be used as the pyroelectric material layer of the pyroelectric sensor. The two surfaces of the capacitor-piezoelectric-pyroelectric layer 3 serve as electrodes. Due to the asymmetry of the PVDF molecular structure, it will polarize when the temperature changes. Therefore, when the capacitor-piezoelectric-pyroelectric layer 3 is heated or cooled, its polarization degree will change, resulting in charge separation, thereby generating a potential difference, and then generating current, so that the sensor can detect pressure and temperature at the same time.

[0039] In order to make the above-mentioned purposes, features and beneficial effects of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] An embodiment of the present invention provides a capacitive-piezoelectric-pyroelectric sensor, which includes a first protective layer 1, a first electrode layer 2, a capacitive-piezoelectric-pyroelectric layer 3, a second electrode layer 4 and a second protective layer 5 in sequence, wherein the first protective layer 1 is located on the outer surface of the first electrode layer 2, the first electrode layer 2 is located between the first protective layer 1 and the capacitive-piezoelectric-pyroelectric layer 3, the second electrode layer 4 is located between the capacitive-piezoelectric-pyroelectric layer 3 and the second protective layer 5, and the second protective layer 5 is located on the outer surface of the second electrode layer 4.

[0041] The first protective layer 1 and the second protective layer 5 are made of insulating materials. As an embodiment, the capacitive-piezoelectric-pyroelectric sensor can be used as a flexible sensor, so the first protective layer 1 and the second protective layer 5 are both made of flexible insulating materials. As an embodiment, the flexible insulating material includes PDMS material.

[0042] The capacitor-piezoelectric-pyroelectric layer 3 is located between the first electrode layer 2 and the second electrode layer 4. The capacitor-piezoelectric-pyroelectric layer 3 includes PVDF material, which can be used as a dielectric material layer of a capacitive sensor, that is, when it is subjected to an external force, it will deform, so that the distance between the first electrode layer 2 and the second electrode layer 4 will change, thereby causing the capacitance to change; the capacitor-piezoelectric-pyroelectric layer 3 can also be used as a piezoelectric material layer of a piezoelectric sensor, that is, when it is subjected to an external force, it will deform, so that charges of opposite polarity and equal magnitude will be generated on the two surfaces of the capacitor-piezoelectric-pyroelectric layer 3. When the external force is removed, the capacitor-piezoelectric-pyroelectric layer 3 returns to a non-charged state. Therefore, in this embodiment, the responses of the capacitive sensor and the piezoelectric sensor are performed simultaneously and do not interfere with each other, thereby achieving the purpose that the pressure sensor can detect static force and dynamic force at the same time. The capacitor-piezoelectric-pyroelectric layer 3 can also be used as a pyroelectric material layer of a sensitive sensor. The two surfaces of the capacitor-piezoelectric-pyroelectric layer 3 are used as electrodes. Due to the asymmetry of the PVDF molecular structure, it will be polarized when the temperature changes. Therefore, when the capacitor-piezoelectric-pyroelectric layer 3 is heated or cooled, its polarization degree will change, resulting in charge separation, thereby generating a potential difference and then generating current. The sensor can detect pressure and temperature at the same time.

[0043] The capacitive-piezoelectric-pyroelectric sensor provided by the present invention can be used as a single sensor, then the first electrode layer 2 and the second electrode layer 4 are single electrodes. The capacitive-piezoelectric-pyroelectric sensor provided by the present invention can also be used as a sensor array, then the first electrode layer 2 and the second electrode layer 4 are electrode arrays respectively. As an embodiment, the first electrode layer 2 includes a plurality of first electrodes distributed in parallel, and the second electrode layer 4 includes a plurality of second electrodes distributed in parallel. In order to locate the force position through the intersection, the first electrode is perpendicular to the second electrode.

[0044] Since the material of the electrode is a mature technology in this field, the present invention does not impose any specific limitation on this. As an embodiment, the first electrode and the second electrode are both made of AgNWS material.

[0045] An embodiment of the present invention further provides a method for preparing a capacitive-piezoelectric-pyroelectric sensor, comprising the following steps:

[0046] 1. Provide a substrate;

[0047] 2. forming a first protective layer 1 on the substrate;

[0048] 3. forming a first patterned first electrode layer 2 on the first protective layer 1, wherein the first electrode layer 2 includes a plurality of first electrodes distributed in parallel;

[0049] 4. preparing the capacitive-piezoelectric-pyroelectric layer 3 on the first electrode layer 2 by electrospinning-hot pressing method;

[0050] 5. forming a second patterned second electrode layer 4 on the capacitive-piezoelectric-pyroelectric layer 3, wherein the second electrode layer 4 comprises a plurality of second electrodes distributed in parallel, and the first electrodes are perpendicular to the second electrodes;

[0051] 6. Forming a second protective layer 5 on the second electrode layer 4 .

[0052] In step (1), the substrate can be a flat substrate such as a glass substrate or a silicon wafer.

[0053] In step (ii), the specific method for forming the first protective layer 1 on the substrate includes: preparing a flexible insulating solution, degassing the flexible insulating solution, spin coating the solution on the substrate, and heating and curing the solution to form the first protective layer 1.

[0054] The flexible insulating solution can be a PDMS solution prepared with a certain mass ratio of PDMS prepolymer and curing agent, such as a PDMS prepolymer and curing agent in a mass ratio of 10:1. Step (ii) specifically includes: firstly preparing a PDMS solution with a mass ratio of 10:1 of PDMS prepolymer and curing agent, and degassing it in a vacuum drying oven at room temperature; then spin coating the PDMS solution on a glass substrate; again, placing the glass substrate with the PDMS solution spin-coated on a hot plate and heating it at 70°C for 2 hours to finally obtain a first protective layer 1.

[0055] Step (iii) specifically includes: placing a first mask on the first protective layer 1 and fixing it. Then spraying a silver nanowire dispersion onto the first protective layer 1, and removing the first mask after the silver nanowire dispersion is cured to obtain the first electrode layer 2. The first electrode layer 2 includes a plurality of first electrodes distributed in parallel, and the first electrodes are row electrodes.

[0056] Step (iv) specifically includes: dissolving PVDF powder in DMF (DMF Chinese name is dimethylformamide, a transparent liquid that is miscible with water and most organic solvents) solvent under stirring in a water bath to obtain PVDF spinning solution; placing the PVDF spinning solution in a syringe, and placing the syringe on a spinning machine injection pump for electrostatic spinning to obtain a PVDF fiber film; placing the PVDF fiber film on the first electrode layer 2, and using hot pressing to prepare the capacitive-piezoelectric-pyroelectric layer 3.

[0057] As a specific implementation method, a certain mass of solvent DMF is weighed into a conical flask using an electronic balance, a magnetic stirrer is added, and the flask is placed in a water bath for stirring; then a certain mass of PVDF powder is weighed, slowly added into the stirring conical flask, and the bottle cap is tightly closed to prevent water vapor from entering the conical flask; the water bath temperature is set to 60°C, and the solution is continuously stirred and dissolved for 4 hours until the solution is clear and transparent, thereby obtaining a PVDF spinning solution of a certain mass concentration. The PVDF spinning solution is pumped into a 20mL syringe, which is fixed to the spinning machine injection pump, and a 20G (1 / 2 inch, flat) stainless steel needle is installed. The needle is connected to the positive electrode of the high-voltage power supply, the receiving roller is connected to the negative electrode of the high-voltage power supply, and the receiving substrate is attached to the roller; the injection pump specification is set to 20mL, the liquid supply speed is 2mL / h, the roller speed is 300 rpm, the slide stroke is 20cm, the spinning distance is 15cm, the spinning voltage is positive 15kV, negative 5kV, the temperature is 35°C, the humidity is 40%, the timing is 120min, and finally the equipment door is closed and the exhaust is turned on to obtain a PVDF fiber film with no beads and broken filaments. The prepared PVDF fiber film is placed on the first electrode layer 2 and a flexible PVDF film is prepared by hot pressing. The flexible PVDF film is the capacitive-piezoelectric-pyroelectric layer 3.

[0058] Step (iv) specifically includes: placing a second mask on the capacitor-piezoelectric-pyroelectric layer 3 and fixing it, then spraying a silver nanowire dispersion onto the capacitor-piezoelectric-pyroelectric layer 3, and removing the second mask after the silver nanowire dispersion is solidified to obtain the second electrode layer 4. The second electrode layer 4 includes a plurality of second electrodes distributed in parallel, which are perpendicular to the first electrodes and are column electrodes.

[0059] The specific method of step (iv) includes: preparing a PDMS solution again with a PDMS prepolymer and a curing agent in a mass ratio of 10:1, and degassing the PDMS solution in a vacuum drying oven at room temperature; then spin coating the PDMS solution on the second electrode layer 4, and after the PDMS solution is spin coated, heating it at 70°C on a hot plate to cure it for 2 hours to obtain a second protective layer 5.

[0060] In summary, the present invention has the following beneficial effects:

[0061] 1. The present invention utilizes a pressure sensor to work in two different sensing modes

[0062] The pressure sensor array prepared by the present invention can work under two different sensing modes: capacitive mode and piezoelectric pyroelectric mode. Capacitive pressure sensor devices can be used as necessary sensor devices for static pressure sensing applications. In the capacitive pressure sensor, the capacitive-piezoelectric-pyroelectric layer 3 is sandwiched between two electrodes (the first electrode layer 2 and the second electrode layer 4) as a dielectric layer. PVDF deforms under the action of pressure, thereby changing the capacity of the capacitive sensor. Therefore, the capacitance on the electrode layer increases. The piezoelectric-based self-powered pressure sensor can be used for dynamic pressure sensing applications. The capacitive-piezoelectric-pyroelectric layer 3 is a piezoelectric material. When an external force is applied in a certain direction of the piezoelectric material to cause it to deform, charges of opposite polarity and equal magnitude will be generated on its two opposite surfaces. The capacitive and piezoelectric sensing modes do not interfere with each other and can be tested simultaneously.

[0063] 2. The present invention uses a pressure sensor to simultaneously detect the pressure and temperature parameters

[0064] In pyroelectric sensors, due to the asymmetry of the PVDF molecular structure, it polarizes when the temperature changes. Therefore, when PVDF is heated or cooled, its polarization degree changes, resulting in charge separation, thereby generating a potential difference. Equal amounts of charges with opposite signs will be generated at both ends of the PVDF crystal. The temperature change can be converted into electrical energy. Temperature detection is performed. Combined with the above-mentioned pressure sensing, a dual-parameter sensing array is formed.

[0065] 3. The present invention uses a word line structure to reduce the number of leads

[0066] In the present invention, the first electrode layer 2 includes a plurality of first electrodes distributed in parallel, and the second electrode layer 4 includes a plurality of second electrodes distributed in parallel, the first electrodes are perpendicular to the second electrodes, and the sensing unit of each individual lead is replaced by a row and column electrode, and these sensing units involve the intersection nodes of the metal row (X) and column (Y) electrodes, which greatly reduces the number of data acquisition channels or addressing lines from (X×Y) to (X+Y), which is beneficial to wiring. Therefore, the sensor array of the present invention adopts a word line structure, which requires fewer electrode lines than an array of single unit leads, greatly reduces the number of wires, and is more suitable for large-area and large-size manufacturing.

[0067] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A capacitive-piezoelectric-pyroelectric sensor, characterized in that: It includes a first electrode layer, a capacitor-piezoelectric-pyroelectric layer and a second electrode layer, wherein the capacitor-piezoelectric-pyroelectric layer is located between the first electrode layer and the second electrode layer; the capacitor-piezoelectric-pyroelectric layer includes PVDF material, and when the capacitor-piezoelectric-pyroelectric layer is subjected to external force, it will deform, and two surfaces of the capacitor-piezoelectric-pyroelectric layer will generate charges of opposite polarity and equal magnitude, and the capacitance between the first electrode layer and the second electrode layer changes; when the capacitor-piezoelectric-pyroelectric layer is heated or cooled, a potential difference is generated on the two surfaces of the capacitor-piezoelectric-pyroelectric layer.

2. The capacitive-piezoelectric-pyroelectric sensor according to claim 1, characterized in that: The first electrode layer includes a plurality of first electrodes distributed in parallel, the second electrode layer includes a plurality of second electrodes distributed in parallel, and the first electrodes are perpendicular to the second electrodes.

3. The capacitive-piezoelectric-pyroelectric sensor according to claim 2, characterized in that: The first electrode and the second electrode are both made of AgNS material.

4. The capacitive-piezoelectric-pyroelectric sensor according to claim 1, characterized in that: It also includes a first protective layer and a second protective layer, wherein the first protective layer is located on the outer surface of the first electrode layer, and the second protective layer is located on the outer surface of the second electrode layer.

5. The capacitive-piezoelectric-pyroelectric sensor according to claim 4, characterized in that: The first protective layer and the second protective layer are both made of flexible insulating material.

6. The capacitive-piezoelectric-pyroelectric sensor according to claim 5, characterized in that: The flexible insulating material comprises PDMS material.

7. A method for preparing a capacitive-piezoelectric-pyroelectric sensor, characterized in that: The following steps are involved: providing a substrate; forming a first protective layer on the substrate; forming a first patterned first electrode layer on the first protective layer, wherein the first electrode layer comprises a plurality of first electrodes distributed in parallel; Preparing a capacitive-piezoelectric-pyroelectric layer on the first electrode layer by using an electrospinning-hot pressing method; forming a second patterned second electrode layer on the capacitive-piezoelectric-pyroelectric layer, wherein the second electrode layer comprises a plurality of second electrodes distributed in parallel, and the first electrodes are perpendicular to the second electrodes; A second protective layer is formed on the second electrode layer.

8. The method for preparing a capacitive-piezoelectric-pyroelectric sensor according to claim 7, characterized in that: The step of forming a first protective layer on the substrate comprises: A flexible insulating solution is prepared, degassed, and then spin-coated on the substrate, and heated and cured to form the first protective layer.

9. The method for preparing a capacitive-piezoelectric-pyroelectric sensor according to claim 8, characterized in that: The flexible insulation solution is prepared by using a PDMS prepolymer and a curing agent.

10. The method for preparing a capacitive-piezoelectric-pyroelectric sensor according to claim 7, characterized in that: The step of forming a first patterned first electrode layer on the first protective layer comprises: A first mask is placed on the first protective layer, and a silver nanowire dispersion is sprayed onto the first protective layer. After the silver nanowire dispersion is solidified, the first mask is removed to obtain the first electrode layer.

11. The method for preparing a capacitive-piezoelectric-pyroelectric sensor according to claim 7, characterized in that: The method of preparing the capacitive-piezoelectric-pyroelectric layer on the first electrode layer by using the electrospinning-hot pressing method comprises: Under stirring conditions in a water bath, PVDF powder is dissolved in DMF solvent to obtain PVDF spinning solution; The PVDF spinning solution is placed in a syringe, and the syringe is placed on a spinning machine syringe pump for electrospinning to obtain a PVDF fiber film; The PVDF fiber film is placed on the first electrode layer, and the capacitive-piezoelectric-pyroelectric layer is prepared by hot pressing.

12. The method for preparing a capacitive-piezoelectric-pyroelectric sensor according to claim 7, characterized in that: The second patterned second electrode layer is formed on the capacitive-piezoelectric-pyroelectric layer, comprising: A second mask is placed on the capacitor-piezoelectric-pyroelectric layer, and a silver nanowire dispersion is sprayed on the capacitor-piezoelectric-pyroelectric layer. After the silver nanowire dispersion is cured, the second mask is removed to obtain the second electrode layer.

13. The method for preparing a capacitive-piezoelectric-pyroelectric sensor according to claim 7, characterized in that: The forming of the second protective layer on the second electrode layer comprises: The flexible insulating solution is spin-coated on the second electrode layer, and after being heated and cured, the second protective layer is formed.

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