Capacitive force sensor, capacitive force sensor preparation method and tension sensor

Abstract

The invention discloses a capacitive force sensor, a capacitive force sensor preparation method and a tension sensor. The flexible force sensor comprises a first electrode; the insulating layer is arranged on the first electrode; the dielectric layer is arranged on the insulating layer, and the dielectric layer comprises a high polymer elastic matrix and a composite film of a porous sponge structure of a carbon nano tube; and a second electrode disposed on the dielectric layer. By utilizing the characteristics of the dielectric layer of the porous sponge structure, not only is the sensitivity of the capacitive force sensor improved, but also the measurement range of the capacitive force sensor is enlarged, and meanwhile, the capacitive force sensor also has the response capability to micro pressure and the quick response time.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a capacitive force sensor, a method for preparing a capacitive force sensor, and a tension sensor. Background Art

[0002] Among the diverse sensing mechanisms of flexible force sensors, capacitive force sensors have attracted widespread attention due to their excellent repeatability, temperature stability, low energy consumption, high spatial resolution, and adaptability to large-area applications.

[0003] In recent years, in order to achieve higher sensitivity, the design of dielectric materials in sensors has been optimized mainly by increasing air gaps or introducing conductive fillers. Among them, the methods of introducing air gaps in dielectric materials include: using micro-nano processing technology to create surface microstructures, constructing nanowire networks, integrating into fabrics or adding spacer layers to enhance the effect of air gaps on capacitance changes. At the same time, in order to significantly improve conductivity, common practices include coating with conductive nanomaterials or doping conductive fillers into dielectric materials.

[0004] However, these current methods of improving sensitivity are only applicable to a smaller force range, and the effect of improving sensitivity is relatively limited. Therefore, how to improve the force range and sensitivity of capacitive flexible force sensors is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present application is to provide a capacitive force sensor, a method for preparing a capacitive force sensor and a tension sensor, so as to solve the technical problems of small force range and low sensitivity of the capacitive flexible force sensor in the prior art.

[0006] To achieve the above objectives and other related objectives, the present application provides a capacitive force sensor, comprising:

[0007] a first electrode;

[0008] An insulating layer, disposed on the first electrode;

[0009] A dielectric layer is disposed on the insulating layer, wherein the dielectric layer comprises a composite film of a polymer elastic matrix and a porous sponge structure of carbon nanotubes;

[0010] The second electrode is disposed on the dielectric layer.

[0011] In an optional embodiment of the present application, in the dielectric layer, a mass ratio ω of the carbon nanotubes to the dielectric layer satisfies: 0.5%≤ω≤4%.

[0012] In an optional embodiment of the present application, the dielectric layer further comprises polyaniline, and the polyaniline is adsorbed on the surface of the carbon nanotubes to form a π-π conjugated system with the carbon nanotubes.

[0013] In an optional embodiment of the present application, the thickness of the insulating layer is between 800 nm and 900 nm.

[0014] In an optional embodiment of the present application, the material of the polymer elastic matrix includes polydimethylsiloxane.

[0015] In an optional embodiment of the present application, the insulating layer is made of at least one of polyethylene, polytetrafluoroethylene, polyvinyl chloride and polyimide.

[0016] In an optional embodiment of the present application, the dielectric layer is prepared by a sacrificial sugar template method.

[0017] In order to achieve the above-mentioned purpose and other related purposes, the present application also provides a tension sensor device, comprising:

[0018] A first component having a first surface;

[0019] A second component has a second surface, wherein the first surface and the second surface are arranged opposite to each other; and

[0020] A capacitive force sensor is sandwiched between the first surface and the second surface, and the capacitive force sensor includes:

[0021] a first electrode;

[0022] An insulating layer, disposed on the first electrode;

[0023] a dielectric layer, disposed on the insulating layer, the dielectric layer comprising a composite film of a polymer elastic matrix and a porous sponge structure of carbon nanotubes; and

[0024] A second electrode is disposed on the dielectric layer;

[0025] The first component and the second component are configured to reduce the distance between the first surface and the second surface when a tensile force is applied to the first component and / or the second component, so as to apply compressive stress to the capacitive force sensor.

[0026] To achieve the above objectives and other related objectives, the present application also provides a method for preparing a capacitive force sensor, comprising:

[0027] A dielectric layer is prepared by a sacrificial sugar template method, wherein the dielectric layer comprises a composite film of a polymer elastic matrix and a porous sponge structure of carbon nanotubes;

[0028] preparing a first electrode, a second electrode and an insulating layer;

[0029] The first electrode, the insulating layer, the dielectric layer and the second electrode are assembled in sequence from bottom to top to obtain the capacitive force sensor.

[0030] In an optional embodiment of the present application, the dielectric layer further comprises polyaniline, and the polyaniline is adsorbed on the surface of the carbon nanotubes to form a π-π conjugated system with the carbon nanotubes.

[0031] The capacitive force sensor of the present application comprises a first electrode, an insulating layer, a dielectric layer and a second electrode, wherein the insulating layer is arranged on the first electrode, the dielectric layer comprises a composite film of a polymer elastic matrix and a porous sponge structure of carbon nanotubes, and the dielectric layer is arranged on the insulating layer; the second electrode is arranged on the dielectric layer. By utilizing the characteristics of the dielectric layer of the porous sponge structure, not only the sensitivity of the capacitive force sensor is improved, but also the measurement range of the capacitive force sensor is improved, and at the same time, the sensor has the ability to respond to tiny pressures and a fast response time. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Shown is a schematic structural diagram of a capacitive force sensor of the present application.

[0033] Figure 2 Shown is a three-dimensional assembly schematic diagram of the capacitive force sensor of the present application.

[0034] Figure 3 Shown is a scanning electron microscope image of the PDMS / CNTS composite porous dielectric layer.

[0035] Figure 4 Shown is a scanning electron microscope image of the PDMS / CNTS / PANI composite porous dielectric layer.

[0036] Figure 5 Shown are Fourier transform infrared spectra of PDMS / CNTS / PANI composite porous dielectric layer, PDMS porous dielectric layer, and PDMS / PANI composite porous dielectric layer.

[0037] Figure 6 Shown is a schematic structural diagram of the tension sensor of the present application. DETAILED DESCRIPTION

[0038] The following describes the implementation of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application.

[0039] See also Figure 1-6 It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present application in a schematic manner, and the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0040] like Figure 1 and 2 As shown, an embodiment of the present application discloses a capacitive force sensor 10. The capacitive force sensor 10 includes a first electrode 11, an insulating layer 12, a dielectric layer 13 and a second electrode 14. The insulating layer 12 is disposed on the first electrode 11, the dielectric layer 13 includes a composite film of a polymer elastic matrix and a porous sponge structure of carbon nanotubes, and the dielectric layer 13 is disposed on the insulating layer 12; the second electrode 14 is disposed on the dielectric layer 13. During preparation, the first electrode 11, the insulating layer 12, the dielectric layer 13 and the second electrode 14 are firstly manufactured separately, and then the first electrode 11, the insulating layer 12, the dielectric layer 13 and the second electrode 14 are assembled in sequence from bottom to top, thereby obtaining a capacitive force sensor 10 with a laminated structure.

[0041] In the present application, the first electrode 11 includes a substrate and an electrode layer disposed on the substrate. The substrate may be a polyethylene terephthalate film PET, a polyimide film, or an indium tin oxide film; the electrode layer may be an electrode material such as gold, silver, copper, platinum, etc., and may be formed on the substrate by a film forming process such as evaporation or magnetron sputtering. The second electrode 14 has the same or similar structure to the first electrode 11, so it will not be described again.

[0042] It should be noted that the electrode layer of the capacitive force sensor 10 can be selected according to different application scenarios. For example, gold is suitable for high-precision electrochemical analysis due to its chemical stability and conductivity; silver is suitable for a variety of electrochemical reactions due to its catalytic activity and stable potential; copper electrodes are widely used in fields such as electrical discharge machining due to their high electrical and thermal conductivity; platinum metal is indispensable in situations where electrodes do not participate in reactions due to its inertness and catalytic properties.

[0043] In the present application, the dielectric layer 13 may include two types of dielectric layers, one is a composite membrane of a porous sponge structure of a polymer elastic matrix and carbon nanotubes prepared by a sacrificial sugar template method, and the other is a composite membrane of a porous sponge structure of a polymer elastic matrix, carbon nanotubes and polyaniline prepared by a sacrificial sugar template method and a polymerization method. In the composite membrane of a porous sponge structure of a polymer elastic matrix and carbon nanotubes, the mass ratio ω of the carbon nanotubes to the dielectric layer 13 satisfies: 0.5%≤ω≤4%, for example 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%. It is understandable that in other embodiments, the mass ratio ω of the carbon nanotubes to the dielectric layer 13 may also be greater than 4.0%.

[0044] In the composite film of the porous sponge structure of the polymer elastic matrix, carbon nanotubes and polyaniline, the polyaniline can be adsorbed on the surface of the carbon nanotubes through a polymerization reaction to form a π-π conjugated system with the carbon nanotubes. The dielectric layer 13 of the porous sponge structure, the interwoven ligament structure inside it not only provides a 3D porous structure to increase the air gap, but also optimizes the electron transmission performance, thereby improving the detection range and sensitivity of the sensor. And due to the appropriate CNTS doping, the ligaments of the dielectric layer 13 are conductive, and an open-pore structure capable of realizing distributed parasitic capacitance can be realized.

[0045] Compared with the composite membrane of the porous sponge structure of the polymer elastic matrix, carbon nanotubes and polyaniline, the composite membrane of the porous sponge structure of the polymer elastic matrix and carbon nanotubes has the advantages of fast response speed, good stability and low detection limit, etc., in which the carbon nanotubes and polyaniline are combined through π-π non-covalent bonds to form a larger π-π conjugated system, and the electron delocalization ability is enhanced, thereby enhancing the conductive performance and increasing the conductivity of the dielectric layer 13. Therefore, the introduction of polyaniline can further improve the sensitivity, conductivity and detection range of the sensor, and also has the advantages of fast response speed, good stability and low detection limit.

[0046] The principle of the porous sponge structure dielectric layer 13 improving the detection range and sensitivity of the sensor is as follows: Since the capacitance change in the capacitive force sensor 10 is mainly affected by two factors, one is the change in the relative distance and relative area between the two plates of the device; the other is the change in the dielectric constant, the sensitivity of the capacitive pressure sensor mainly depends on the conductivity and deformation of the dielectric layer 13. When pressure is applied to the porous sponge structure dielectric layer 13, the compression generated by the dielectric layer 13 will cause the polymer elastic matrix to occupy the air gap when it is not pressed, thereby causing a change in the distance between the plates, and the porous sponge structure dielectric layer 13 has a large number of air gaps, which makes it easier to deform and the deformation is larger, so that the device has a wider detection range and higher sensitivity. The dielectric constant of the dielectric layer 13 is higher than that of air, so after applying pressure, the change in the dielectric constant will also increase the sensitivity. By adding conductive fillers (carbon nanotubes or carbon nanotubes and polyaniline composites), the sensitivity of the sensor can be improved in terms of the dielectric constant. This is because the conductive fillers are mixed into the insulating polymer elastic matrix. Since there is a significant difference in the conductivity of the polymer elastic matrix and the conductive fillers, a large amount of charge will accumulate at the boundary between them, resulting in interface polarization. This phenomenon further increases the dielectric constant of the dielectric layer 13 and the sensitivity of the sensor. As the conductive filler component increases, the interface polarization effect becomes more significant.

[0047] In the present application, the material of the polymer elastic matrix can be, for example, polydimethylsiloxane (PDMS). The advantages of PDMS are mainly reflected in the following aspects: first, its elastomer is extremely sensitive to small changes in physical quantities in the outside world, which significantly improves the sensitivity of the capacitive sensor. Secondly, the elastomer helps to reduce errors, thereby improving the accuracy and stability of the measurement. In addition, PDMS has excellent flexibility and durability, and can withstand various environmental changes and mechanical vibrations during long-term use, which enhances the reliability of the capacitive sensor. The elastomer also has strong adaptability and can be adjusted and replaced according to the shape and size of the object to be measured, so that it is suitable for objects of different shapes and sizes to be measured, thereby expanding the application range and flexibility of the capacitive force sensor 10. Finally, compared with the sensitive layer of other sensors, the PDMS elastomer in the capacitive sensor has a lower manufacturing cost, a simple manufacturing process, and is easy to mass produce, which also helps to reduce the manufacturing cost of the sensor. It is understandable that in other embodiments, terephthalate PET, polyimide, PI, polyurethane PU, etc. can also be used as polydimethylsiloxane PDMS.

[0048] In the present application, the insulating layer 12 is arranged between the first electrode 11 and the dielectric layer 13, and the insulating layer 12 is arranged to play an insulating role, so that the device has capacitive properties. The thickness of the insulating layer 12 is between 800nm ​​and 900nm, for example, 800nm, 820nm, 840nm, 860nm, 880nm, 900nm or any value within the above range. It should be noted that in the capacitive force sensor 10, a reasonable thickness of the insulating layer 12 helps to improve the performance of the sensor. First, it helps to improve the sensitivity of the sensor, because the dielectric properties of the insulating layer 12 directly affect the change in capacitance, thereby affecting the sensor's ability to detect small displacements. Secondly, a reasonable thickness of the insulating layer 12 can reduce the parasitic capacitance between the plates, which may affect the output stability and accuracy of the sensor. In addition, the appropriate thickness of the insulating layer 12 can also prevent electrical breakdown between the plates, especially in high-voltage or high-temperature working environments, which is crucial to ensuring the safety and reliability of the sensor. Finally, a reasonable thickness of the insulating layer 12 helps to reduce external electromagnetic interference, improve the anti-interference ability of the sensor, and ensure that the sensor can work stably in a complex electromagnetic environment.

[0049] The material of the insulating layer 12 can be one of polyethylene (PE), polytetrafluoroethylene, polyvinyl chloride, polyimide or a combination thereof. The insulating layer 12 of different materials can be selected according to the actual use requirements of the capacitive force sensor 10. For example, the polyethylene insulating layer 12 is environmentally friendly and has good electrical insulation performance, but is not suitable for high temperature environments; polytetrafluoroethylene is chemically resistant and non-sticky, and has stable performance; polyvinyl chloride is low-cost and flame-retardant, but contains halogens and has poor thermal stability; polyimide has excellent high-temperature stability and insulation, and is suitable for high-performance applications.

[0050] This application also introduces a method for preparing a PDMS / CNTS composite porous dielectric layer using a sacrificial sugar template method, and the specific process is as follows:

[0051] Add carbon nanotubes (CNTS) to n-hexane dispersant (of course, other types of dispersants can also be used), stir evenly, and then ultrasonically disperse the obtained solution to obtain solution A; mix PDMS monomer and n-hexane dispersant (of course, other types of dispersants can also be used) and ultrasonically treat and evenly mix to obtain solution B; mix solution A and solution B evenly and ultrasonically disperse to obtain solution C, and add PDMS curing agent to solution C and mix evenly, using magnetic stirring; use instant sugar cubes as a template for preparing PCL, immerse the instant sugar cubes into solution C after adding PDMS curing agent, seal and place in a refrigerator to stand; put the instant sugar cubes soaked in solution C into an oven to solidify PDMS, and obtain a carbon nanotube-doped PDMS nanocomposite material carrying a sugar cube skeleton; peel off the excess nanocomposite material, put it into water to dissolve the instant sugar cubes as a template, and thus obtain a porous structure composite material PCL doped with PDMS by CNTS. The amount of carbon nanotubes can be adjusted to prepare a PDMS / CNTS composite porous dielectric layer with a carbon nanotube mass ratio of 0.5% to 4%.

[0052] The preparation method of the PDMS / CNTS composite porous dielectric layer will be described in detail below with a specific example:

[0053] First, 0.22g of multi-walled carbon nanotubes were added to 10ml of n-hexane, and the solution obtained by ultrasonic dispersion for 3h after stirring was ultrasonically treated to obtain solution A. Secondly, 10g of PDMS monomer was mixed with 10ml of n-hexane and ultrasonically treated to obtain solution B. Solution A and solution B were mixed evenly and ultrasonically dispersed for 3h to obtain solution C, and 1g of PDMS curing agent was added to solution C to mix evenly, and magnetic stirring was used for 10-20min. Instant sugar cubes were used as templates for preparing PCL. The specific method was: immerse the instant sugar cubes in solution C, seal them and place them in a refrigerator for 24h. The instant sugar cubes soaked with solution C were placed in an oven at 60°C for 90min to solidify PDMS and obtain a CNTS-doped PDMS nanocomposite material carrying a sugar cube skeleton. Finally, the excess nanocomposite material was peeled off and placed in water to dissolve the instant sugar cubes used as templates, thereby obtaining a PDMS / CNTS composite porous dielectric layer with a carbon nanotube mass fraction of approximately 2%. Figure 3 The scanning electron microscope (SEM) image of the PCL composite material is shown, which clearly demonstrates the three-dimensional network structure of the PCL composite material.

[0054] The preparation method of the PDMS / CNTS composite porous dielectric layer of the present application adopts sugar cubes as sacrificial templates and utilizes the uniform combination inside the sugar cubes to provide a more controllable and uniform pore distribution for the polymer elastic matrix. This preparation method is not only simple to manufacture and low in cost, but also conducive to industrial production.

[0055] This application also introduces a method for preparing a PDMS / CNTS / PANI composite porous dielectric layer by combining a sacrificial sugar template method with a polymerization method. The specific process is as follows:

[0056] First, a PDMS / CNTS composite porous dielectric layer is prepared by a sacrificial sugar template method; then the PDMS / CNTS composite porous dielectric layer is placed in an aniline monomer solution, and then an ammonium persulfate solution is quickly poured into the aniline monomer solution containing the PDMS / CNTS composite porous dielectric layer, and a polymerization reaction is carried out with stirring. After a certain polymerization time under ice-water bath conditions, the PDMS / CNTS composite porous dielectric layer is taken out, and quickly rinsed with deionized water and alcohol, and then placed in an oven to dry after being rinsed clean. Finally, a PDMS / CNTS / PANI composite porous dielectric layer is obtained. Under ice bath conditions, the polymerization reaction time t satisfies: 15min≤t≤35min. For example, t is 15min, 20min, 25min, 30min, 35min or any value within the above range, such as 25min.

[0057] The preparation method of the PDMS / CNTS / PANI composite porous dielectric layer will be described in detail below with a specific example:

[0058] First, prepare a PDMS / CNTS porous composite dielectric layer with a mass fraction of carbon nanotubes of approximately 2wt%. Then, in the process of synthesizing PANI, place it in aniline monomer solution D, which is a solution obtained by dissolving aniline monomer in HCL aqueous solution and dispersing it evenly under ice bath conditions. Then dissolve ammonium persulfate in HCL aqueous solution to obtain solution E, and quickly pour liquid E into liquid D containing the porous dielectric layer, and a polymerization reaction occurs with stirring. After reacting for 25 minutes under ice water bath conditions, remove the porous dielectric layer from the reacted solution, quickly rinse it with deionized water and alcohol, and place it in an oven after rinsing it clean, and dry it at 60°C for 12 hours. In this way, a PDMS / CNTS / PANI composite porous dielectric layer is obtained. Figure 4 A scanning electron microscope (SEM) photograph of the PDMS / CNTS / PANI composite porous dielectric layer is shown. It can be seen from the figure that dispersed CNTS agglomerates can be observed on the skeleton of the sponge structure, and aniline is adsorbed on the surface of CNTS to polymerize and grow to form polyaniline. During the polymerization process, CNTS acts as a crystal nucleus, causing PANI to adsorb and grow on the surface of CNTS.

[0059] Figure 5The Fourier transform infrared spectra of the PDMS / CNTS / PANI composite porous dielectric layer, the PDMS porous dielectric layer, and the PDMS / PANI composite porous dielectric layer are shown, wherein the PDMS porous dielectric layer and the PDMS / PANI composite porous dielectric layer can be prepared by referring to the sacrificial sugar template method described above. Figure 5 It can be seen that two characteristic peaks appear at 910cm-1 and 1580cm-1, which are caused by the stretching vibration of the CH and diarylamine CN bonds of the π-disubstituted benzene ring, respectively. In addition, the characteristic peaks at 1490cm-1 and 1410cm-1 are caused by the stretching vibration of the C=C in the quinone ring and the benzene ring, respectively; the CN stretching vibration peak of the quinone ring appears at 1310cm-1; the peak at 1660cm-1 corresponds to the C=N vibration in the quinone structure. These peaks appear simultaneously in the infrared spectrum of the CNT / PANI nanocomposite, indicating that the emeraldine salt phase in the nanocomposite contains the main characteristic peaks of PANI. It should be noted that the same peak also exists in CNTS and CNT / PANI nanocomposites, but the peak position has changed. This shows that with the polymerization of polyaniline, the resonance frequency of the conjugated bond decreases, that is, the flow capacity of electrons on the conjugated large π bond is enhanced, thereby enhancing its conductivity. At the same time, this also provides spectral evidence for the increase in conductivity obtained in the conductivity test with the increase in PANI polymerization time. The CN stretching vibration peak of the quinone ring appears at 1310cm-1. This is a weak peak in the pure PANI / PDMS layer, but in the spectrum of the PDMS / CNTS / PANI composite porous dielectric layer, the intensity of this peak is significantly enhanced, indicating that the vibration units of the CN bond in the PDMS / CNTS / PANI composite porous dielectric layer are significantly increased. This new CN covalent bond is mainly formed between the imine nitrogen atom in the aniline molecule and the carbon atom in the carbon nanotube, which further explains the existence of a certain interface effect between CNTS and PANI.

[0060] like Figure 6 As shown, the embodiment of the present application also introduces a tension sensing device, including a first component 20, a second component 30 and a capacitive force sensor 10. The first component 20 has a first surface; the second component 30 has a second surface, and the first surface and the second surface are arranged opposite to each other; the first component 20 and the second component 30 are configured to reduce the distance between the first surface and the second surface when tension is applied to the first component 20 and / or the second component 30, so as to apply compressive stress to the capacitive force sensor 10, thereby achieving the purpose of measuring tension. The capacitive force sensor 10 adopts Figure 1 and Figure 2 For the structure shown, please refer to the description of the relevant part above.

[0061] In summary, the capacitive force sensor of the present application includes a first electrode, an insulating layer, a dielectric layer and a second electrode, wherein the insulating layer is disposed on the first electrode, the dielectric layer includes a composite film of a polymer elastic matrix and a porous sponge structure of carbon nanotubes, and the dielectric layer is disposed on the insulating layer; the second electrode is disposed on the dielectric layer. By utilizing the characteristics of the dielectric layer of the porous sponge structure, not only the sensitivity of the capacitive force sensor is improved, but also the measurement range of the capacitive force sensor is improved.

[0062] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

[0063] The above description of the embodiment shown in the application (including the content described in the abstract of the specification) is not intended to be exhaustive or to limit the application to the precise form disclosed herein. Although the specific embodiment of the application and the example of the application are described herein for the purpose of illustration only, as those skilled in the art will recognize and understand, various equivalent modifications can be within the spirit and scope of the application. As pointed out, these modifications can be made to the application according to the above description of the embodiment described in the application, and these modifications will be within the spirit and scope of the application.

[0064] Thus, although the present application has been described herein with reference to specific embodiments thereof, freedom of modification, various changes and substitutions are also within the above disclosure, and it should be understood that in some cases, some features of the present application will be adopted without corresponding use of other features without departing from the scope and spirit of the proposed application. Therefore, many modifications may be made to adapt specific environments or materials to the substantial scope and spirit of the present application. The present application is not intended to be limited to the specific terms used in the claims below and / or the specific embodiments disclosed as the best mode for carrying out the present application, but the present application will include any and all embodiments and equivalents falling within the scope of the appended claims. Thus, the scope of the present application will be determined solely by the appended claims.

Claims

1. A capacitive force sensor, characterized in that: include: a first electrode; An insulating layer, disposed on the first electrode; A dielectric layer is disposed on the insulating layer, wherein the dielectric layer comprises a composite film of a polymer elastic matrix and a porous sponge structure of carbon nanotubes; The second electrode is disposed on the dielectric layer.

2. The capacitive force sensor according to claim 1, characterized in that: In the dielectric layer, a mass ratio ω of the carbon nanotubes to the dielectric layer satisfies: 0.5%≤ω≤4%.

3. The capacitive force sensor according to claim 1, characterized in that: The dielectric layer further comprises polyaniline, which is adsorbed on the surface of the carbon nanotubes to form a π-π conjugated system with the carbon nanotubes.

4. The capacitive force sensor according to claim 1, characterized in that: The thickness of the insulating layer is between 800nm ​​and 900nm.

5. The capacitive force sensor according to claim 1, characterized in that: The material of the high polymer elastic matrix includes polydimethylsiloxane.

6. The capacitive force sensor according to claim 1, characterized in that: The insulating layer is made of at least one of polyethylene, polytetrafluoroethylene, polyvinyl chloride and polyimide. 7 . The capacitive force sensor according to claim 1 , wherein the dielectric layer is prepared by a sacrificial sugar template method.

8. A tension sensor device, characterized in that: include: A first component having a first surface; A second component has a second surface, wherein the first surface and the second surface are arranged opposite to each other; as well as A capacitive force sensor is sandwiched between the first surface and the second surface, and the capacitive force sensor includes: a first electrode; An insulating layer, disposed on the first electrode; a dielectric layer, disposed on the insulating layer, the dielectric layer comprising a composite film of a polymer elastic matrix and a porous sponge structure of carbon nanotubes; and A second electrode is disposed on the dielectric layer; The first component and the second component are configured to reduce the distance between the first surface and the second surface when a tensile force is applied to the first component and / or the second component, so as to apply compressive stress to the capacitive force sensor.

9. A method for preparing a capacitive force sensor, characterized in that: include: A dielectric layer is prepared by a sacrificial sugar template method, wherein the dielectric layer comprises a composite film of a polymer elastic matrix and a porous sponge structure of carbon nanotubes; preparing a first electrode, a second electrode and an insulating layer; The first electrode, the insulating layer, the dielectric layer and the second electrode are assembled in sequence from bottom to top to obtain the capacitive force sensor.

10. The method for preparing a capacitive force sensor according to claim 9, characterized in that: The dielectric layer further comprises polyaniline, which is adsorbed on the surface of the carbon nanotubes to form a π-π conjugated system with the carbon nanotubes.

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