Capacitive pressure sensor and preparation method thereof

Abstract

The present invention is applicable to the field of sensor technology and provides a capacitive pressure sensor and a method for preparing the same. The capacitive pressure sensor comprises: an upper electrode layer, a lower electrode layer, and a dielectric layer located between the two electrode layers; the upper electrode layer and the lower electrode layer are composed of a plurality of first cellular structures arranged in an array, and the dielectric layer is composed of a plurality of second cellular structures arranged in an array; the first cellular structure and the second cellular structure are different; and the longitudinal cross-sections of the first cellular structure and the second cellular structure are both symmetrical structures with a zero Poisson's ratio, similar to a fingertip gyroscope. The present invention introduces a zero Poisson's ratio cellular structure similar to a fingertip gyroscope into the upper electrode layer, the lower electrode layer, and the dielectric layer located between the two electrode layers, so that the overall structure of the sensor exhibits zero Poisson's ratio mechanical properties. The fingertip gyroscope-like zero Poisson's ratio cellular structure is arranged in an array, thereby improving the measurement accuracy of the sensor while also improving the flexibility and sensitivity of the sensor.

Description

Technical Field

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

[0002] A capacitive pressure sensor consists of an upper electrode plate, a lower electrode plate, and a dielectric layer located between the two plates. The dielectric layer senses the magnitude of external pressure through its own deformation. When the sensor is subjected to pressure, the upper electrode plate will displace downward under the load, causing the dielectric layer to deform and reducing the distance between the two electrode plates. At this time, the capacitance between the two electrode plates changes as the distance between the plates changes. This change in capacitance is the sensor's signal output. Therefore, for a constant pressure, the greater the change in capacitance, the higher the sensor's sensitivity.

[0003] The current methods for improving sensor sensitivity mainly include increasing the flexibility of the capacitive pressure sensor or increasing the dielectric constant of the capacitive pressure sensor. The existing technology has a method of introducing a zero Poisson's ratio structure into the dielectric layer of the capacitive sensor, which improves the sensitivity of the sensor by microstructuring the internal electrodes and dielectric layer of the sensor, thereby improving the performance of the sensor. However, it only improves the mechanical deformation characteristics of the dielectric layer, does not comprehensively optimize the overall structure of the capacitive sensor, and does not make further sensitivity-enhancing designs for the structure of the dielectric layer matrix. At the same time, the traditional dielectric layer structure often produces additional strain perpendicular to the load direction when under pressure, resulting in strain loss, which affects the accuracy of the capacitive pressure sensor. Summary of the Invention

[0004] The embodiments of the present invention provide a capacitive pressure sensor and a method for manufacturing the same, so as to improve the flexibility and sensitivity of the capacitive pressure sensor and the measurement accuracy of the sensor.

[0005] In a first aspect, an embodiment of the present invention provides a capacitive pressure sensor, comprising: an upper electrode layer, a lower electrode layer, and a dielectric layer located between the two electrode layers;

[0006] The upper electrode layer and the lower electrode layer are composed of a plurality of first cell structures arranged in an array, and the dielectric layer is composed of a plurality of second cell structures arranged in an array; the first cell structure and the second cell structure are different;

[0007] The longitudinal sections of the first cellular structure and the second cellular structure are both fingertip gyroscope-type zero Poisson's ratio symmetrical structures; the fingertip gyroscope-type zero Poisson's ratio symmetrical structure is a structure including a first fan blade, three other fan blades that are symmetrical with the first fan blade in the upper and lower left and right directions, a vertical connecting wall located on the left and right symmetry axis of the first fan blade and the other three fan blades, and a horizontal connecting wall located on the upper and lower symmetry axis of the first fan blade and the other three fan blades.

[0008] As another embodiment of the present application, the capacitive pressure sensor further includes:

[0009] The upper surface of the dielectric layer is a layer of uncured polydimethylsiloxane adhesive, and is connected to the upper electrode layer;

[0010] The lower surface of the dielectric layer is a layer of uncured polydimethylsiloxane adhesive, and is connected to the lower electrode layer;

[0011] The upper surface of the upper electrode layer and the lower surface of the lower electrode layer are both provided with a layer of encapsulating silica gel.

[0012] As another embodiment of the present application, the first cellular structure is a cellular structure composed of a polydimethylsiloxane material mixed with ultra-high carbon fibers and carbon nanotubes;

[0013] The second cellular structure is a cellular structure composed of a polydimethylsiloxane material mixed with carbon nanotubes.

[0014] As another embodiment of the present application, the equivalent Poisson's ratio formula of the characterization structure of the fidget gyro type zero Poisson's ratio structure is:

[0015]

[0016] Wherein, υ represents the equivalent Poisson's ratio, A represents the transverse strain of the fingertip gyro type zero Poisson's ratio structure, B represents the longitudinal strain of the fingertip gyro type zero Poisson's ratio structure, A0, A1, A2, A3, A 41 、A 42 、A 51 、A 52 、A 53 、A 54 and A 55 They respectively represent the intermediate result algebraic expressions corresponding to the transverse strain, F represents the equivalent concentrated force of the external uniformly distributed load on the fidget gyro type zero Poisson's ratio structure, L represents the oblique length of the fan blade in the longitudinal section, E represents the bending elastic modulus of the material, I represents the moment of inertia of the longitudinal section, r1 represents the first tangent radian of the longitudinal section, r2 represents the second tangent radian of the longitudinal section, B0, B1, B2, B3, B4 and B5 respectively represent the intermediate result algebraic expressions corresponding to the longitudinal strain.

[0017] As another embodiment of the present application, the intermediate algebraic expressions corresponding to the lateral strain are:

[0018] A0=m+Lsinβ+r2;

[0019]

[0020]

[0021] A 42 =-6(-2+π)r1 2 (Lsinβ+2r2)-2Lπr1cosβ(Lsinβ+3r2);

[0022] A 51 =(-4+π)r1 3 -r1 2 (2L+πr2);

[0023]

[0024] A 53 =-2L 2 (cosβ-(-2+π)sinβ);

[0025] A 54 =Lr2(-2πcosβ+(-2+π)(2+πsinβ));

[0026]

[0027] Among them, m represents the overhanging length of the transverse connecting wall in the fingertip gyroscope type zero Poisson's ratio structure, L represents the length of the oblique side of the fan blade of the fingertip gyroscope type zero Poisson's ratio structure, β is the angle between the oblique side of the fan blade of the fingertip gyroscope type zero Poisson's ratio structure and the horizontal direction, S represents the area of ​​the longitudinal section, k represents the shear constant, and G represents the shear elastic modulus of the fingertip gyroscope type zero Poisson's ratio structure.

[0028] As another embodiment of the present application, the intermediate algebraic expressions corresponding to the longitudinal strain are:

[0029] B0=m+Lcosβ+r1;

[0030]

[0031] B 32 =-Lπr1cosβ(Lcosβ-3r2)-3(-2+π)r1 2 (Lcosβ-2r2);

[0032]

[0033] B 51 =(-8+π 2 )r1 3 +(-8+3π)r1 2 (2L+πr2);

[0034]

[0035] in,

[0036] In a second aspect, an embodiment of the present invention provides a method for preparing a capacitive pressure sensor, comprising:

[0037] Making a mold corresponding to a basic component of a capacitive pressure sensor, wherein the basic component includes an upper electrode layer, a lower electrode layer, and a dielectric layer located between the two electrode layers;

[0038] The mold corresponding to the basic component is used to manufacture the basic component of the capacitive pressure sensor, wherein the upper electrode layer and the lower electrode layer are composed of a plurality of first cellular structures arranged in an array, and the dielectric layer is composed of a plurality of second cellular structures arranged in an array; the first cellular structure and the second cellular structure are different; the longitudinal sections of the first cellular structure and the second cellular structure are both fingertip gyroscope-type zero-Poisson's ratio symmetrical structures; the fingertip gyroscope-type zero-Poisson's ratio symmetrical structure is a structure including a first fan blade, three other fan blades that are symmetrical with the first fan blade in the upper and lower directions, a vertical connecting wall located on the left and right symmetry axis of the first fan blade and the other three fan blades, and a horizontal connecting wall located on the upper and lower symmetry axis of the first fan blade and the other three fan blades.

[0039] As another embodiment of the present application, the mold corresponding to the basic components of the capacitive pressure sensor includes:

[0040] Using 3D printing technology, a first fingertip gyroscope type zero Poisson's ratio structure mold corresponding to the upper electrode layer and the lower electrode layer is manufactured;

[0041] A second fingertip gyro type zero Poisson's ratio structure mold corresponding to the dielectric layer is manufactured using 3D printing technology.

[0042] As another embodiment of the present application, manufacturing the basic component of the capacitive pressure sensor according to the mold corresponding to the basic component includes:

[0043] A first mixed liquid is obtained by using a polydimethylsiloxane material mixed with ultra-high carbon fibers and carbon nanotubes, and the uncured first mixed liquid is placed into the first fingertip gyro type zero Poisson's ratio structure mold to obtain the upper electrode layer and the lower electrode layer of the capacitive pressure sensor;

[0044] A second mixed liquid is obtained by using a polydimethylsiloxane material mixed with carbon nanotubes, and the uncured second mixed liquid is placed into the second fingertip gyro type zero Poisson's ratio structure mold to obtain the dielectric layer of the capacitive pressure sensor.

[0045] As another embodiment of the present application, the method for preparing a capacitive pressure sensor further includes:

[0046] connecting the upper surface of the dielectric layer to the upper electrode layer via a layer of uncured polydimethylsiloxane adhesive;

[0047] connecting the lower surface of the dielectric layer to the lower electrode layer via a layer of uncured polydimethylsiloxane adhesive;

[0048] A layer of encapsulating silica gel is scraped onto the upper surface of the upper electrode layer and the lower surface of the lower electrode layer.

[0049] An embodiment of the present invention provides a capacitive pressure sensor and a preparation method thereof. By introducing a fingertip gyroscope-like zero-Poisson's ratio cellular structure into an upper electrode layer, a lower electrode layer, and a dielectric layer located between the two motor layers, the overall structure of the sensor exhibits zero-Poisson's ratio mechanical characteristics. The fingertip gyroscope-like zero-Poisson's ratio cellular structure is arranged in an array to achieve a zero-Poisson's ratio porous treatment effect on the two electrode layers and the dielectric layer of the sensor, thereby improving the flexibility and sensitivity of the sensor and improving the measurement accuracy of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

[0051] Figure 1 1 is a schematic structural diagram of a capacitive pressure sensor provided by an embodiment of the present invention;

[0052] Figure 2 is a structural schematic diagram of a capacitive pressure sensor provided by another embodiment of the present invention;

[0053] Figure 3 This is a schematic diagram of a zero Poisson's ratio structure of a fingertip gyroscope provided by an embodiment of the present invention;

[0054] Figure 4 is a schematic diagram of the 3D structure of a capacitive pressure sensor provided by an embodiment of the present invention;

[0055] Among them, 1-upper electrode layer, 2-lower electrode layer, 3-dielectric layer, 4-first cellular structure, 5-second cellular structure, 21-upper surface of the dielectric layer, 22-lower surface of the dielectric layer, 23-upper surface of the upper electrode layer, 24-lower surface of the lower electrode layer, 31-first fan blade, 32-vertical connecting wall, 33-first arc surface, 34-horizontal connecting wall, 35-second arc surface, 41-3D upper electrode layer, 42-3D lower electrode layer, 43-3D dielectric layer. DETAILED DESCRIPTION

[0056] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0057] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below with reference to the accompanying drawings.

[0058] Figure 1 The structural diagram of the capacitive pressure sensor provided by the embodiment of the present invention is described in detail as follows.

[0059] The capacitive pressure sensor in the embodiment of the present invention may include:

[0060] An upper electrode layer 1, a lower electrode layer 2, and a dielectric layer 3 located between the two electrode layers;

[0061] The upper electrode layer 1 and the lower electrode layer 2 are composed of a plurality of first cellular structures 4 arranged in an array, and the dielectric layer 3 is composed of a plurality of second cellular structures 5 arranged in an array; the first cellular structure 4 and the second cellular structure 5 are different;

[0062] The longitudinal sections of the first cellular structure 4 and the second cellular structure 5 are both fingertip gyroscope-type zero Poisson's ratio symmetrical structures; the fingertip gyroscope-type zero Poisson's ratio symmetrical structure is a structure including a first fan blade, the other three fan blades that are symmetrical with the first fan blade in the upper and lower left and right directions, a vertical connecting wall located on the left and right symmetry axis of the first fan blade and the other three fan blades, and a horizontal connecting wall located on the upper and lower symmetry axis of the first fan blade and the other three fan blades.

[0063] It should be noted that, in addition to introducing the fingertip gyroscope-type zero Poisson's ratio symmetrical structure into the dielectric layer 3 of the capacitive pressure sensor in the embodiment of the present invention, a fingertip gyroscope-type zero Poisson's ratio microstructure array is also applied to the upper electrode layer 1 and the lower electrode layer 2, so that the lateral strain of the sensor approaches zero, and the overall structure presents zero Poisson's ratio mechanical properties, which effectively reduces the strain loss of the sensor and thereby improves the measurement accuracy of the above-mentioned capacitive pressure sensor.

[0064] like Figure 2 As shown, the capacitive pressure sensor in the embodiment of the present invention may further include:

[0065] The upper surface 21 of the dielectric layer 3 is a layer of uncured polydimethylsiloxane adhesive and is connected to the upper electrode layer 1;

[0066] The lower surface 22 of the dielectric layer 3 is a layer of uncured polydimethylsiloxane adhesive and is connected to the lower electrode layer 2;

[0067] The upper surface 23 of the upper electrode layer 1 and the lower surface of the lower electrode layer 2 are both covered with a layer of encapsulating silica gel.

[0068] Optionally, the first cellular structure 4 is a cellular structure composed of a polydimethylsiloxane material mixed with ultra-high carbon fibers and carbon nanotubes, and the second cellular structure 5 is a cellular structure composed of a polydimethylsiloxane material mixed with carbon nanotubes.

[0069] It should be noted that mixing carbon nanotubes into the polydimethylsiloxane matrix as the material of the second cellular structure 5 can effectively improve the dielectric constant of the dielectric layer 3, which is beneficial to improving the conversion efficiency of the change in the distance between the upper electrode layer 1 and the lower electrode layer 2 to the change in capacitance value, thereby improving the sensitivity of the sensor.

[0070] Optional, Figure 3 Figure 2 is a schematic diagram of the zero-Poisson's ratio symmetrical structure of a fingertip gyroscope, i.e., a longitudinal cross-sectional view of the first cellular structure 4 and the second cellular structure 5. When the capacitive pressure sensor is subjected to force, stress acts on the vertical connecting wall 32, the transverse connecting wall 34, the first blade 31, and the other three blades symmetrical to the first blade 31. The first tangent arc r1 between the vertical connecting wall 32 and the first curved surface 33 and the second tangent arc r2 between the transverse connecting wall 34 and the second curved surface 35 are both reduced.

[0071] like Figure 3 The equivalent Poisson's ratio formula of the fingertip gyroscope zero Poisson's ratio symmetrical structure is as follows:

[0072]

[0073] Among them, υ represents the equivalent Poisson's ratio, A represents the transverse strain of the fingertip gyroscope zero Poisson's ratio structure, B represents the longitudinal strain of the fingertip gyroscope zero Poisson's ratio structure, A0, A1, A2, A3, A 41 、A 42 、A 51 、A 52 、A 53 、A 54 and A 55 are the intermediate algebraic expressions corresponding to the transverse strain, F represents the equivalent concentrated force of the external uniformly distributed load on the fingertip gyroscope type zero Poisson's ratio structure, L represents the oblique length of the fan blade in the longitudinal section, E represents the bending elastic modulus of the material, I represents the moment of inertia of the longitudinal section, r1 represents the first tangent radian of the longitudinal section, r2 represents the second tangent radian of the longitudinal section, B0, B1, B2, B3, B4 and B5 represent the intermediate algebraic expressions corresponding to the longitudinal strain, respectively.

[0074] Furthermore, the intermediate algebraic expressions corresponding to the lateral strain of the fingertip gyro type zero Poisson's ratio structure are:

[0075] A0=m+Lsinβ+r2;

[0076]

[0077] A 42 =-6(-2+π)r1 2 (Lsinβ+2r2)-2Lπr1cosβ(Lsinβ+3r2);

[0078] A 51 =(-4+π)r1 3 -r1 2 (2L+πr2);

[0079]

[0080] A 53 =-2L 2 (cosβ-(-2+π)sinβ);

[0081] A 54 =Lr2(-2πcosβ+(-2+π)(2+πsinβ));

[0082]

[0083] Among them, m represents the outward extension length of the transverse connecting wall 34 in the fingertip gyroscope type zero Poisson's ratio structure, L represents the length of the oblique side of the fan blade 31 of the fingertip gyroscope type zero Poisson's ratio structure, β represents the angle between the oblique side of the fan blade 31 of the fingertip gyroscope type zero Poisson's ratio structure and the horizontal direction, S represents the area of ​​the longitudinal section, k represents the shear constant, and G represents the shear elastic modulus of the fingertip gyroscope type zero Poisson's ratio structure.

[0084] Optionally, the shear constant k in the embodiment of the present invention is a fixed value of 1.2.

[0085] Furthermore, the intermediate algebraic expressions corresponding to the longitudinal strain of the fingertip gyro-type zero Poisson's ratio structure are:

[0086] B0=m+Lcosβ+r1;

[0087]

[0088] B 32 =-Lπr1cosβ(Lcosβ-3r2)-3(-2+π)r1 2 (Lcosβ-2r2);

[0089]

[0090] B 51 =(-8+π 2 )r1 3 +(-8+3π)r1 2 (2L+πr2);

[0091]

[0092] in,

[0093] It should be noted that the above-mentioned fingertip gyroscope-type zero Poisson's ratio cell structure is arranged in an array to form the upper electrode layer, lower electrode layer and dielectric layer of the sensor, which improves the conversion efficiency of the distance change between the two electrode layers to the capacitance value change, thereby improving the flexibility and sensitivity of the sensor.

[0094] The above-mentioned capacitive pressure sensor introduces a fingertip gyroscope-type zero Poisson's ratio cellular structure into the upper electrode layer, the lower electrode layer and the dielectric layer located between the two motor layers, so that the lateral strain of the capacitive pressure sensor approaches zero, and the overall structure of the sensor presents a zero Poisson's ratio mechanical property, which effectively reduces the strain loss of the sensor, thereby improving the measurement accuracy of the sensor; the fingertip gyroscope-type zero Poisson's ratio cellular structure is arranged in an array to achieve a zero Poisson's ratio porous treatment effect on the two electrode layers and the dielectric layer of the sensor, thereby improving the conversion efficiency of the distance change between the two electrode layers to the capacitance value change, and improving the flexibility and sensitivity of the sensor; using a polydimethylsiloxane matrix material mixed with carbon nanotubes, the dielectric constant of the sensor dielectric layer is increased, and the sensitivity of the sensor during measurement is improved.

[0095] An embodiment of the present invention further provides a method for preparing a capacitive pressure sensor, comprising:

[0096] A mold corresponding to the basic components of the capacitive pressure sensor is manufactured, wherein the basic components of the capacitive pressure sensor include Figure 1 Shown are an upper electrode layer 1, a lower electrode layer 2 and a dielectric layer 3 located between the two electrode layers.

[0097] Optionally, a 3D printing technology is used to manufacture a first fingertip gyroscope type zero Poisson's ratio structure mold corresponding to the upper electrode layer 1 and the lower electrode layer 2 .

[0098] Optionally, a 3D printing technology is used to manufacture a second fingertip gyro type zero Poisson's ratio structure mold corresponding to the dielectric layer 3 .

[0099] The mold corresponding to the above-mentioned basic components is used to manufacture the basic components of the capacitive pressure sensor, wherein the upper electrode layer 1 and the lower electrode layer 2 are composed of a plurality of first cellular structures 4 arranged in an array, and the dielectric layer 3 is composed of a plurality of second cellular structures 5 arranged in an array; the first cellular structure 4 and the second cellular structure 5 are different; the longitudinal sections of the first cellular structure 4 and the second cellular structure 5 are both fingertip gyroscope-type zero-Poisson's ratio symmetrical structures; the fingertip gyroscope-type zero-Poisson's ratio symmetrical structure is a structure including a first fan blade, three other fan blades that are symmetrical with the first fan blade in the upper and lower directions, a vertical connecting wall located on the left and right symmetry axis of the first fan blade and the other three fan blades, and a horizontal connecting wall located on the upper and lower symmetry axis of the first fan blade and the other three fan blades.

[0100] Optionally, a polydimethylsiloxane material mixed with ultra-high carbon fiber and carbon nanotubes is used to obtain a first blended liquid, and the uncured first blended liquid is placed in a first fingertip gyroscope-type zero Poisson's ratio structure mold and compressed under certain external conditions to preliminarily form a conductive network with a fingertip gyroscope-type zero Poisson's ratio structure, and then the preliminarily formed conductive network is subjected to external forced compression to obtain an upper electrode layer 1 and a lower electrode layer 2 with a dense fingertip gyroscope-type zero Poisson's ratio structure.

[0101] Optionally, a polydimethylsiloxane material mixed with carbon nanotubes is used to obtain a second mixed liquid, and the uncured second mixed liquid is placed in a second fingertip gyro type zero Poisson's ratio structure mold to obtain the dielectric layer 3 of the capacitive pressure sensor.

[0102] Optionally, the upper surface 21 of the dielectric layer 3 is connected to the upper electrode layer 1 through a layer of uncured polydimethylsiloxane adhesive, the lower surface 22 of the dielectric layer 3 is connected to the lower electrode layer 2 through a layer of uncured polydimethylsiloxane adhesive, and a layer of encapsulating silicone is scraped on the upper surface 23 of the upper electrode layer 1 and the lower surface 24 of the lower electrode layer 2.

[0103] like Figure 4 , which is a schematic diagram of the 3D structure of a capacitive pressure sensor obtained by the above-mentioned preparation method according to an embodiment of the present invention, includes an upper electrode layer 41 , a lower electrode layer 42 and a dielectric layer 43 located between the two electrode layers.

[0104] The above-mentioned capacitive pressure sensor preparation method can quickly obtain an upper electrode layer, a lower electrode layer and a dielectric layer with a fingertip gyroscope-like zero Poisson's ratio structure by making the materials and molds of the capacitive pressure sensor, so that the obtained sensor has good flexibility and sensitivity, thereby making the measurement results more accurate.

[0105] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0106] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A capacitive pressure sensor, characterized in that: include: an upper electrode layer, a lower electrode layer, and a dielectric layer located between the two electrode layers; The upper electrode layer and the lower electrode layer are composed of a plurality of first cell structures arranged in an array, and the dielectric layer is composed of a plurality of second cell structures arranged in an array; the first cell structure and the second cell structure are different; The longitudinal sections of the first cellular structure and the second cellular structure are both fingertip gyroscope-type zero Poisson's ratio symmetrical structures; the fingertip gyroscope-type zero Poisson's ratio symmetrical structure is a structure including a first fan blade, three other fan blades that are symmetrical with the first fan blade in the upper and lower left and right directions, a vertical connecting wall located on the left and right symmetry axis of the first fan blade and the other three fan blades, and a transverse connecting wall located on the upper and lower symmetry axis of the first fan blade and the other three fan blades; each fan blade includes a first arc connected to the vertical connecting wall, a second arc connected to the transverse connecting wall, and an oblique edge connected between the first arc and the second arc, the first arc bends in a direction away from the vertical connecting wall, the second arc bends in a direction away from the transverse connecting wall, two adjacent first arcs constitute a first arc surface, two adjacent second arcs constitute a second arc surface, and the first tangent arc is between the vertical connecting wall and the first arc surface. The second tangent arc is between the transverse connecting wall and the second arc surface. , the length of the oblique side is , the transverse connecting wall extends outward relative to each blade, and the extension length of the transverse connecting wall is .

2. The capacitive pressure sensor according to claim 1, wherein: The capacitive pressure sensor further includes: The upper surface of the dielectric layer is a layer of uncured polydimethylsiloxane adhesive, and is connected to the upper electrode layer; The lower surface of the dielectric layer is a layer of uncured polydimethylsiloxane adhesive, and is connected to the lower electrode layer; The upper surface of the upper electrode layer and the lower surface of the lower electrode layer are both provided with a layer of encapsulating silica gel.

3. The capacitive pressure sensor according to claim 2, wherein: The first cellular structure is a cellular structure composed of a polydimethylsiloxane material mixed with ultra-high carbon fibers and carbon nanotubes; The second cellular structure is a cellular structure composed of a polydimethylsiloxane material mixed with carbon nanotubes.

4. The capacitive pressure sensor according to claim 3, wherein: The equivalent Poisson's ratio formula for the characterization structure of the fingertip gyro type zero Poisson's ratio structure is: in, represents the equivalent Poisson's ratio, represents the lateral strain of the fingertip gyro type zero Poisson's ratio structure, represents the longitudinal strain of the fingertip gyro type zero Poisson's ratio structure, 、 、 、 、 、 、 、 、 、 and They represent the intermediate algebraic expressions corresponding to the transverse strain, represents the equivalent concentrated force of the external uniformly distributed load on the fidget gyro type zero Poisson's ratio structure, represents the oblique length of the fan blade in the longitudinal section, represents the bending elastic modulus of the material, represents the moment of inertia of the longitudinal section, represents the first tangent arc of the longitudinal section, represents the second tangent arc of the longitudinal section, 、 、 、 、 and They respectively represent the intermediate algebraic expressions corresponding to the longitudinal strain.

5. The capacitive pressure sensor according to claim 4, characterized in that: The intermediate algebraic expressions corresponding to the transverse strain are: ； ； ； ； ； ； ； ； ； ； ； in, represents the outward extension length of the transverse connecting wall in the fingertip gyro type zero Poisson's ratio structure, represents the oblique side length of the fan blade of the fingertip gyro type zero Poisson's ratio structure, is the angle between the oblique side of the fan blade of the fingertip gyroscope type zero Poisson's ratio structure and the horizontal direction, represents the area of ​​the longitudinal section, represents the shear constant, represents the shear elastic modulus of the fidget gyro type zero Poisson's ratio structure.

6. The capacitive pressure sensor according to claim 5, characterized in that: The intermediate algebraic expressions corresponding to the longitudinal strain are: ； ； ； ； ； ； ； ； in, , .

7. A method for preparing a capacitive pressure sensor, characterized in that: include: Making a mold corresponding to a basic component of a capacitive pressure sensor, wherein the basic component includes an upper electrode layer, a lower electrode layer, and a dielectric layer located between the two electrode layers; The mold corresponding to the basic component is used to manufacture the basic component of the capacitive pressure sensor, wherein the upper electrode layer and the lower electrode layer are composed of a plurality of first cellular structures arranged in an array, and the dielectric layer is composed of a plurality of second cellular structures arranged in an array; the first cellular structure and the second cellular structure are different; the longitudinal sections of the first cellular structure and the second cellular structure are both fingertip gyroscope-type zero Poisson's ratio symmetrical structures; the fingertip gyroscope-type zero Poisson's ratio symmetrical structure includes a first fan blade, three other fan blades that are symmetrical with the first fan blade in the upper and lower directions, and a left-right opposite position between the first fan blade and the other three fan blades. The structure of the vertical connecting wall on the axis of symmetry and the transverse connecting wall located on the upper and lower symmetry axes of the first fan blade and the other three fan blades; each fan blade includes a first arc connected to the vertical connecting wall, a second arc connected to the transverse connecting wall and an oblique edge connected between the first arc and the second arc, the first arc is bent in the direction away from the vertical connecting wall, the second arc is bent in the direction away from the transverse connecting wall, two adjacent first arcs constitute a first arc surface, two adjacent second arcs constitute a second arc surface, and the first tangent arc is between the vertical connecting wall and the first arc surface. The second tangent arc is between the transverse connecting wall and the second arc surface. , the length of the oblique side is , the transverse connecting wall extends outward relative to each blade, and the extension length of the transverse connecting wall is .

8. The preparation method according to claim 7, characterized in that The mold corresponding to the basic components of the capacitive pressure sensor includes: Using 3D printing technology, a first fingertip gyroscope type zero Poisson's ratio structure mold corresponding to the upper electrode layer and the lower electrode layer is manufactured; A second fingertip gyro type zero Poisson's ratio structure mold corresponding to the dielectric layer is manufactured using 3D printing technology.

9. The preparation method according to claim 8, characterized in that The method of manufacturing the basic component of the capacitive pressure sensor according to the mold corresponding to the basic component includes: A first mixed liquid is obtained by using a polydimethylsiloxane material mixed with ultra-high carbon fibers and carbon nanotubes, and the uncured first mixed liquid is placed into the first fingertip gyro type zero Poisson's ratio structure mold to obtain the upper electrode layer and the lower electrode layer of the capacitive pressure sensor; A second mixed liquid is obtained by using a polydimethylsiloxane material mixed with carbon nanotubes, and the uncured second mixed liquid is placed into the second fingertip gyro type zero Poisson's ratio structure mold to obtain the dielectric layer of the capacitive pressure sensor.

10. The preparation method according to claim 9, characterized in that The method for preparing the capacitive pressure sensor further includes: connecting the upper surface of the dielectric layer to the upper electrode layer via a layer of uncured polydimethylsiloxane adhesive; connecting the lower surface of the dielectric layer to the lower electrode layer via a layer of uncured polydimethylsiloxane adhesive; A layer of encapsulating silica gel is scraped onto the upper surface of the upper electrode layer and the lower surface of the lower electrode layer.

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