CN117007215A - Pressure sensor simulation system with variable dielectric constant and design method thereof - Google Patents

Abstract

This application provides a design method for a pressure sensor simulation system with variable dielectric constant. The dielectric constant of the insulating layer is set to be variable, and ε _(r) is used to represent the position on the insulating layer at a distance r from the center of the circle. Relative dielectric constant, construct the expression of the output capacitance of the basic model in the contact state, where the output capacitance includes the output capacitance of the contact area and the output capacitance of the non-contact area, based on the condition that the output capacitance of the contact area changes linearly with the pressure, derivation The expression of the relative dielectric constant ε _(r) ; and then setting the dielectric constant at any position on the insulating layer according to ε _(r) . This design allows the pressure sensor to increase the output capacitance of the contact area. Linearity, while improving the linearity of the output capacitance in the non-contact area, so that the overall capacitance of the pressure sensor can maintain a high linearity. This application also provides a pressure sensor simulation system with variable dielectric constant.

Description

A pressure sensor simulation system with variable dielectric constant and its design method

Technical field

The present application belongs to the technical field of pressure sensors, and specifically relates to a pressure sensor simulation system with variable dielectric constant and a design method thereof.

Background technique

A pressure sensor is a measuring device that converts pressure signals into electrical signals. The design process of the pressure sensor mainly includes two stages, one is the early simulation stage, and the other is the late physical stage. The simulation stage refers to designing the simulation model of the pressure sensor. Through the simulation model, performance-related simulation tests are conducted to verify the design. feasibility; the entity stage refers to manufacturing a pressure sensor entity with the same structure as the simulation model based on the results of the simulation stage, and conducting performance-related tests on the pressure sensor entity. Among them, the simulation stage does not require additional manufacturing of the physical structure of the pressure sensor, and has the advantages of adjustable parameters and convenient testing. The design process in the simulation phase is implemented through the simulation system.

In related technologies, the design of a pressure sensor simulation system usually includes two parts. The first part is the structural design on the pressure sensing side, and the second part is the circuit design on the signal conversion side. The reasonable design of both can improve the detection of the pressure sensor. Accuracy. Among them, the design of the pressure sensor mainly tends to optimize the diaphragm for pressure sensing, and improve the vibration performance of the pressure sensor by changing the material or thickness of the diaphragm. However, in the hardware structure of the pressure sensor, the diaphragm The vibration needs to be transmitted to the plate of the capacitor through the corresponding connector, so that there is no direct connection between the diaphragm and the capacitor. The influence of the diaphragm on the capacitance change is also limited by the connection structure between the diaphragm and the plate. The designed There is still a certain gap between the linearity of the pressure sensor and the ideal linearity.

Therefore, it is necessary to provide a pressure sensor simulation system with variable dielectric constant and a design method thereof to solve the above problems.

Contents of the invention

This application provides a pressure sensor simulation system with variable dielectric constant and a design method thereof. The dielectric constant of the insulating layer is set to be variable, and ε _(r) is used to represent the relative position on the insulating layer at a distance r from the center of the circle. Dielectric constant, construct the expression of the output capacitance of the basic model in the contact state, where the output capacitance includes the output capacitance of the contact area and the output capacitance of the non-contact area, based on the condition that the output capacitance of the contact area changes linearly with the pressure, the result is derived The expression of the relative dielectric constant ε _(r) is given, and then the dielectric constant at any position on the insulating layer is set according to the expression of ε _(r) to complete the construction of the basic model. This design method can improve the linearity of the pressure sensor.

In order to solve the above technical problems, the technical solution of this application is:

A design method for a pressure sensor simulation system with variable dielectric constant, including the following steps:

S1: Construct a basic model of the pressure sensor. The basic model includes a support frame and two flexible electrodes. The support frame surrounds a cylindrical chamber with openings at both ends. The two flexible electrodes respectively cover and completely seal the Both ends of the chamber are open, and the chamber is set in a vacuum state; two flexible electrodes are spaced apart to form a capacitor, at least one of the flexible electrodes is used to sense pressure and produce deformation, and at least one of the flexible electrodes is located in the chamber. A film-like insulation layer is attached to one side;

S2: Set the dielectric constant of the insulating layer to be variable, use ε _(r) to represent the relative dielectric constant of the position on the insulating layer at a distance r from the center of the circle, and construct the output capacitance of the basic model in the contact state. Expression, wherein the output capacitance includes a contact area output capacitance and a non-contact area output capacitance, and based on the linear change of the contact area output capacitance and pressure, the expression of the relative dielectric constant ε _(r) is derived;

S3: Set the dielectric constant at any position on the insulating layer according to the expression of ε _(r) , complete the construction of the basic model, conduct a simulation test on the pressure sensor simulation system, measure the performance, and according to the test results Optimize and adjust the attribute parameters of the basic model to obtain the final simulation system.

Preferably, the pressure sensor is a contact pressure sensor. When the pressure is equal to the critical pressure, the two flexible electrodes are in just contact but do not squeeze each other; when the pressure is less than the critical pressure, the two flexible electrodes do not contact; When the pressure is greater than the critical pressure, the two flexible electrodes contact and squeeze each other.

Preferably, the flexible electrode includes a deformation area located opposite the chamber and a fixed area located on the periphery of the deformation area. The fixed area is fixed to the support frame, and the deformation area is used to sense pressure generation. Deformation, the shape of the deformation zone is the same as the cross-sectional shape of the chamber, and the insulation layer is attached to the deformation zone.

Preferably, the insulating layer and the central axis of the flexible electrode are located on the same straight line, and the insulating layer completely covers the exposed surface of the flexible electrode in the chamber.

Preferably, the contact area output capacitance C _t is expressed as:

In the formula, a _t represents the radius of the contact area; ε ₀ represents the vacuum dielectric constant; t _ox represents the thickness of the insulating layer.

Preferably, the structures of the two flexible electrodes are the same, both of the flexible electrodes are used to sense pressure and produce deformation, and the insulation layer is attached to one side of the two flexible electrodes located in the chamber. The thickness of the insulating layer on the two flexible electrodes is equal.

Preferably, the expression of the contact area output capacitance C _t is rewritten as:

Taking the differential of the contact area radius a _t for C _t we can get:

The contact area radius a _t is a function of pressure P. Under the condition that the contact area output capacitance C _t and pressure P change linearly, the contact area radius a _t and pressure P need to satisfy a linear functional relationship, so the above formula is further rewritten as:

but:

in, Represents the output sensitivity of the contact area of the pressure sensor; for the contact area, r= _at , then the above formula can be simplified to:

In the formula, D represents the bending stiffness of the deformation zone, and g represents the height of the chamber.

Preferably, one of the flexible electrodes is used to sense pressure and produce deformation, and the other flexible electrode is isolated from the outside world through a base and is not affected by pressure, and the insulating layer is provided on the flexible electrode connected to the base.

Preferably, the derivation process of the relative dielectric constant ε _(r) includes the following steps:

Rewrite the expression of output capacitance C _t as:

Taking the differential of the contact area radius a _t for C _t we can get:

The radius of the contact area a _t is a function of the pressure P. Under the condition that the output capacitance of the contact area changes linearly with the pressure, the above equation is further rewritten as:

but:

in, Represents the output sensitivity of the contact area of the pressure sensor; for the contact area, r= _at , then the above formula can be simplified to:

In the formula, D represents the bending stiffness of the deformation zone, and g represents the height of the chamber.

This application also provides a pressure sensor simulation system with variable dielectric constant, including:

Basic model: The basic model includes a support frame and electrodes. The basic model includes a support frame and two flexible electrodes. The support frame surrounds a cylindrical chamber with openings at both ends. The two flexible electrodes cover and The openings at both ends of the chamber are completely closed, and the chamber is set to a vacuum state; the two flexible electrodes are spaced apart to form a capacitor, at least one of the flexible electrodes is used to sense pressure and produce deformation, and at least one of the flexible electrodes is located A film-like insulating layer is attached to one side of the chamber;

Calculation module: used to set the dielectric constant of the insulating layer to be variable, using ε _(r) to represent the relative dielectric constant of the position on the insulating layer at a distance r from the center of the circle, and construct the basic model in the contact state The expression of the output capacitance, wherein the output capacitance includes the contact area output capacitance and the non-contact area output capacitance, and based on the linear change of the contact area output capacitance and pressure, the expression of the relative dielectric constant ε _(r) is derived;

Parameter setting module: used to set the dielectric constant at any position on the insulating layer according to the expression of ε _(r) , complete the construction of the basic model, conduct simulation tests on the pressure sensor simulation system, and measure Performance, optimize and adjust the attribute parameters of the basic model according to the test results to obtain the final simulation system.

The beneficial effects of this application are:

This application sets the dielectric constant of the insulating layer to be variable, and uses ε _(r) to represent the relative dielectric constant of the position on the insulating layer at a distance r from the center of the circle, and constructs the output capacitance of the basic model in the contact state. Expression, wherein the output capacitance includes a contact area output capacitance and a non-contact area output capacitance, and based on the linear change of the contact area output capacitance and pressure, the expression of the relative dielectric constant ε _(r) is derived; and then according to ε _(r) Set the dielectric constant at any position on the insulating layer. This design allows the pressure sensor to improve the linearity of the output capacitance in the contact area, and at the same time improves the linearity of the output capacitance in the non-contact area, so that the pressure The overall capacitance of the sensor can maintain high linearity.

Description of the drawings

Figure 1 shows a schematic structural diagram of a pressure sensor basic model provided by this application;

Figure 2 shows the usage state diagram of the basic model shown in Figure 1;

Figure 3 shows the relationship curve between the theoretical dielectric constant ε _(r) of the insulating layer shown in Figure 1 and r after taking the logarithm;

Figure 4 shows the capacitance-pressure curve of a common contact pressure sensor;

Figure 5 shows the capacitance-pressure curve of the basic model of the pressure sensor shown in Figure 1;

Figure 6 shows a comparison chart between the basic model of the pressure sensor described in Figure 1 and the capacitance-pressure curve of an ordinary pressure sensor;

Figure 7 shows a schematic structural diagram of another pressure sensor basic model provided by this application;

Figure 8 shows the usage state diagram of the basic model shown in Figure 7;

Figure 9 shows the capacitance-pressure curve of the basic model of the pressure sensor shown in Figure 7;

Figure 10 shows a comparison diagram of the capacitance-pressure curve of the basic model of the pressure sensor described in Figure 7 and that of an ordinary pressure sensor.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

Please refer to Figures 1-10. The present invention provides a design method for a pressure sensor simulation system with variable dielectric constant, which includes the following steps:

S1: Construct a basic model 100 of the pressure sensor. The basic model 100 includes a support frame 10 and two flexible electrodes 20. The support frame 10 surrounds a cylindrical chamber 11 open at both ends. The two flexible electrodes 20 Cover and completely seal the openings at both ends of the chamber 11 respectively, and the chamber 11 is set to a vacuum state; two flexible electrodes 20 are spaced apart to form a capacitor, and at least one of the flexible electrodes 20 is used to sense pressure and generate deformation. , at least one side of the flexible electrode 20 located in the chamber 11 is attached with a film-like insulating layer 30 .

In the basic model 100 of the pressure sensor, flexible electrodes are used to equivalently replace the combined structure of the diaphragm, connectors and electrodes in the traditional non-contact pressure sensor, making the overall structure simpler. The flexible electrode 20 directly senses pressure and deforms after being affected by the pressure, thereby causing the capacitance between the two flexible electrodes 20 to change. In the traditional non-contact pressure sensor, the pressure is sensed through the diaphragm. The deformation of the diaphragm needs to be transmitted to the electrode through the corresponding connection structure, so that the deformation of the diaphragm is not directly related to the change of capacitance. The diaphragm has an impact on the capacitance change. The influence is also limited by the connection structure between the diaphragm and the plate. In the basic model 100 of the pressure sensor provided by this application, the pressure directly acts on the flexible electrode 20. Compared with the traditional non-contact pressure sensor, more sensitive pressure changes can be obtained, which can improve the detection sensitivity.

Furthermore, the basic model 100 of the pressure sensor is a contact pressure sensor, that is, during the measurement process, contact can occur between the two flexible electrodes 20, and after the contact, as the contact area increases, contact can still occur. Bring about changes in capacitance and continue the measurement process.

The flexible electrode 20 includes a deformation area 21 located opposite the chamber 11 and a fixed area 22 located on the periphery of the deformation area 21. The fixed area 22 is fixed to the support frame 10. The deformation area 21 The shape is the same as the cross-sectional shape of the chamber 11, which is circular. During use, the deformation zone 21 is used to sense pressure and deform, thereby changing the distance between the two flexible electrodes 20 and causing changes in capacitance; the fixation zone 22 is only used to form a fixation effect. , no deformation occurs.

During use, the basic model 100 of the pressure sensor includes the following states:

(1) Critical state: The pressure on the deformation zone 21 is equal to the critical pressure. The two flexible electrodes 20 are in perfect contact but do not squeeze. The critical pressure P _t is expressed as:

In the formula, D represents the bending stiffness of the deformation zone 21; g represents the height of the chamber; a represents the radius of the deformation zone 21;

(2) Low pressure state: the pressure on the deformation zone 21 is less than the critical pressure, and the two flexible electrodes 20 do not come into contact and maintain a certain distance;

(3) High-pressure state: the pressure on the deformation zone 21 is greater than the critical pressure, and the two flexible electrodes 20 come into contact and are extruded.

At least one side of the flexible electrode 20 located in the chamber 11 is attached with a film-like insulating layer 30 . It should be noted that when the insulating layer 30 is not attached to the surface of the flexible electrode 20, it itself is a conductive electrode, and the two conductive electrodes are spaced apart to form a capacitor. When the insulating layer 30 is attached to the surface of the flexible electrode, , that is, a double-layer structure including a conductive electrode and an insulating layer. When two flexible electrodes come into contact, there is no contact between the two conductive electrodes, but they are separated by the insulating layer.

In a traditional non-contact pressure sensor, the diaphragm drives two electrodes to move in parallel. Once the two electrodes come into contact, the distance between the two electrodes will not change, and the output capacitance of the entire sensor will no longer change. changes to reach the sensor's pressure measurement threshold. Therefore, if you want to obtain a larger measurement range, you need to increase the distance between the two electrodes so that the electrodes can obtain a larger change stroke. This method will increase the volume of the sensor. In this application, the deformation is directly generated by the flexible electrode 20. Since the degree of freedom at the center position of the flexible electrode 20 is greater than the degree of freedom at the edge position, the deformation amount at the center position is greater than the deformation amount at the edge position. Therefore, the two The center position of the flexible electrode 20 will be in contact first. As the measurement pressure increases, the area of the contact part also gradually increases. After the two electrodes are in contact, capacitance changes can still occur to maintain continuous measurement. When the two electrodes are initially the same, In the case of spacing, the measurement range of the sensor can be greatly increased, which is suitable for measurement of large pressure.

When subjected to pressure P, the deflection w _(r) of the deformation zone 21 at a distance r from the center of the circle is expressed as:

In the formula, w ₀ represents the deflection of the center of the deformation zone 21;

in,

In the formula, E, v, and h represent the Young's modulus, Poisson's ratio, and thickness of the deformation zone 21 respectively.

S2: Set the dielectric constant of the insulating layer to be variable, use ε _(r) to represent the relative dielectric constant of the position on the insulating layer at a distance r from the center of the circle, and construct the output capacitance of the basic model in the contact state. Expression, wherein the output capacitance includes a contact area output capacitance and a non-contact area output capacitance, and based on the condition that the contact area output capacitance changes linearly with pressure, the expression of the relative dielectric constant ε _(r) is derived.

In traditional non-contact pressure sensors, the insulating layer 30 usually uses a single material, and the relative dielectric constant is fixed everywhere. The output capacitance changes through changes in the electrode spacing. The output capacitance is inversely proportional to the electrode spacing. Therefore, the traditional The structural pressure sensor has poor linearity. Similarly, in the contact pressure sensor, if the dielectric constant of the insulating layer 30 remains constant, after the two electrodes 20 come into contact, the contact area will not produce new deformation, so that the capacitor formed by the contact area will The spacing is constant to the thickness of the insulating layer 30. As the pressure continues to increase, the contact area further expands. Due to the film stress, the nonlinearity between the change of the contact area of the two electrodes 20 and the pressure increases, resulting in an increase in the contact area. The linearity of capacitance change and pressure becomes worse; the capacitance of the uncontacted area increases as the pressure increases and then remains basically unchanged, causing the linearity of the overall output capacitance to decrease.

In the basic model 100 provided in this application, the output capacitance of the basic model 100 of the pressure sensor includes two parts, one part is the output capacitance of the contact part, and the other part is the output capacitance of the non-contact part. Due to the existence of stress, during the deformation process of the flexible electrode 20, nonlinear changes are likely to occur between the area and pressure of the contact part, which in turn leads to nonlinear changes between the capacitance of the contact part and the outside world. The relative dielectric constant of the insulating layer 30 is set to a variable form. In the derivation process of ε _(r) , the functional relationship between ε _(r) and r is directly derived based on the linear change of the output partial capacitance, and This guides the setting of the dielectric constant at any position of the insulating layer 30, which can well compensate for the nonlinearity of the capacitance of the contact part due to the existence of stress, so that the output capacitance of the contact part can maintain a high relationship with the external pressure. linearity. The distance between the uncontacted parts gradually decreases, and the area of the uncontacted parts also gradually decreases. The capacitance of the uncontacted parts increases first and then remains basically unchanged. Due to the setting of ε _(r) , the capacitance-pressure curve of the uncontacted parts remains unchanged. The total capacitance output by the basic model 100 of the pressure sensor is the sum of the capacitance of the contact part and the capacitance of the non-contact part. Therefore, the basic model 100 of the pressure sensor proposed in this application has high Linear.

Preferably, the insulating layer 30 completely covers the exposed surface of the flexible electrode 20 in the chamber 11 .

S3: Set the dielectric constant at any position on the insulating layer according to the expression of ε _(r) , complete the construction of the basic model, conduct a simulation test on the pressure sensor simulation system, measure the performance, and according to the test results Optimize and adjust the attribute parameters of the basic model to obtain the final simulation system.

The process of simulation test adopts conventional technology in this field, for example, COSMOL software can be used. The final simulation system can be used to guide the subsequent production of the pressure sensor and provide theoretical guidance for the design of the pressure sensor.

Please refer to Figures 1-6. In one embodiment of the present application, the two flexible electrodes 20 are both used to sense pressure and produce deformation. The two flexible electrodes 20 have the same structure. The two flexible electrodes 20 are located at The insulating layer 30 is attached to both sides of the chamber 11 , and the thickness of the insulating layer on the two flexible electrodes 20 is equal.

It can be seen from Figure 5 that the capacitance of the contact part can maintain a high linearity, while the capacitance of the non-contact part increases with the increase of pressure, and the linearity is improved; as can be seen from Figure 6, compared with ordinary contact pressure Compared with the sensor, the linearity of this embodiment is 1.2% and the linearity of the ordinary contactor pressure sensor is 8.4%. This embodiment has higher linearity.

Without contact:

The output capacitance of the pressure sensor:

In contact state:

The output capacitance C ₂ of the pressure sensor includes two parts: the first part is the contact area capacitance C _t ; the second part is the non-contact area capacitance C _ut ; C ₂ =C _t +C _ut .

in,

In the formula, a _t represents the radius of the contact area,

In the formula,

Since the relative dielectric constant ε _(r) of the insulating layer is a function of r, the contact area capacitance C _t can also be rewritten as:

Taking the differential of the contact area radius a _t for C _t we can get:

Under the condition that the output capacitance of the contact area changes linearly with the pressure, the radius of the contact area a _t and the pressure P need to satisfy a linear functional relationship, so the above equation is further rewritten as:

but:

in, Represents the output sensitivity of the contact area of the pressure sensor; for the contact area, r= _at , then the above formula can be simplified to:

Please refer to 7-10. In another embodiment of the present application, one of the flexible electrodes 20 is used to sense pressure and produce deformation, and the other flexible electrode 20 is isolated from the outside world through the base 40 and is not affected by pressure. The insulating layer 30 is disposed on the flexible electrode 20 connected to the base 40 .

It can be seen from Figure 9 that the capacitance of the contact part can maintain a high linearity, while the capacitance of the non-contact part increases with the increase of pressure, and the linearity is improved; as can be seen from Figure 10, compared with ordinary contact pressure Compared with the sensor, the linearity of this embodiment is 1.8% and the linearity of the ordinary contact pressure sensor is 8.4%. This embodiment has higher linearity.

In the non-contact state, the capacitance C ₁ output by the pressure sensor is expressed as:

In the formula, ε ₀ represents the vacuum dielectric constant; t _ox represents the thickness of the insulating layer, and θ represents the central angle. In the non-contact state, the output capacitance of the pressure sensor is inversely proportional to the electrode spacing, so there is a high degree of nonlinearity between the output capacitance and pressure.

In contact state:

The output capacitance C ₂ of the pressure sensor includes two parts: the first part is the contact area capacitance C _t ; the second part is the non-contact area capacitance C _ut ; C ₂ =C _t +C _ut .

in,

In the formula, a _t represents the radius of the contact area,

In the formula,

Since the relative dielectric constant ε _(r) of the insulating layer is a function of r, the contact area capacitance C _t can also be rewritten as:

Taking the differential of the contact area radius a _t for C _t we can get:

The radius of the contact area a _t is a function of the pressure P. Under the condition that the output capacitance of the contact area changes linearly with the pressure, the above equation is further rewritten as:

but:

in, Represents the output sensitivity of the contact area of the pressure sensor; for the contact area, r= _at , then the above formula can be simplified to:

In the previous embodiment, the two flexible electrodes 20 are both attached with an insulating layer 30. Therefore, in order to adapt to this deformation mode, the chamber 11 needs to select a larger height. The thickness of the insulating layer 30 It needs to be set smaller, for example, the height of the chamber is twice the height of the chamber in the latter embodiment, and the thickness of the insulating layer is half of the thickness of the insulating layer in the latter embodiment. As the height of the chamber increases, the value of the capacitance C _ut of the non-contact area can be reduced, so that the former embodiment can achieve better linearity than the latter embodiment.

It should be noted that the least squares method is used to fit the output capacitance-pressure curve of the sensor, and the percentage of nonlinearity (NL) is calculated using the following formula:

Among them, C _max and C _min are the maximum and minimum capacitance in the interval, |ΔC ₊ | and |ΔC _- | are the maximum and minimum deviations of the fitted straight line from the actual value.

The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above-mentioned specific implementations. The above-mentioned specific implementations are only illustrative and not restrictive. Those of ordinary skill in the art will Inspired by this application, many forms can be made without departing from the purpose of this application and the scope protected by the claims, all of which fall within the protection of this application.

Claims (10)

1. A design method for a pressure sensor simulation system with variable dielectric constant, which is characterized in that it includes the following steps: S1: Construct a basic model of the pressure sensor. The basic model includes a support frame and two flexible electrodes. The support frame surrounds a cylindrical chamber with openings at both ends. The two flexible electrodes respectively cover and completely seal the Both ends of the chamber are open, and the chamber is set in a vacuum state; two flexible electrodes are spaced apart to form a capacitor, at least one of the flexible electrodes is used to sense pressure and produce deformation, and at least one of the flexible electrodes is located in the chamber. A film-like insulation layer is attached to one side; S2: Set the dielectric constant of the insulating layer to be variable, use ε _(r) to represent the relative dielectric constant of the position on the insulating layer at a distance r from the center of the circle, and construct the output capacitance of the basic model in the contact state. Expression, wherein the output capacitance includes a contact area output capacitance and a non-contact area output capacitance, and based on the linear change of the contact area output capacitance and pressure, the expression of the relative dielectric constant ε _(r) is derived; S3: Set the dielectric constant at any position on the insulating layer according to the expression of ε _(r) , complete the construction of the basic model, conduct a simulation test on the pressure sensor simulation system, measure the performance, and according to the test results Optimize and adjust the attribute parameters of the basic model to obtain the final simulation system. 2. The design method of a pressure sensor simulation system with variable dielectric constant according to claim 1, characterized in that the pressure sensor is a contact pressure sensor, and when the pressure is equal to the critical pressure, the two flexible electrodes are exactly Contact but not mutual extrusion; when the pressure is less than the critical pressure, the two flexible electrodes do not contact; when the pressure is greater than the critical pressure, the two flexible electrodes contact and form mutual extrusion. 3. The design method of a pressure sensor simulation system with variable dielectric constant according to claim 1, wherein the flexible electrode includes a deformation zone disposed directly opposite the chamber and a deformation zone located on the periphery of the deformation zone. A fixed area, the fixed area is fixed to the support frame, the deformation area is used to sense pressure and generate deformation, the shape of the deformation area is the same as the cross-sectional shape of the chamber, and the insulation layer is attached to the on the deformation zone. 4. The design method of a pressure sensor simulation system with variable dielectric constant according to claim 3, wherein the insulating layer and the central axis of the flexible electrode are located on the same straight line, and the insulating layer is completely Cover the exposed surface of the flexible electrode in the chamber. 5. The design method of a pressure sensor simulation system with variable dielectric constant according to claim 1, characterized in that the contact area output capacitance C _t is expressed as: In the formula, a _t represents the radius of the contact area; ε ₀ represents the vacuum dielectric constant; t _ox represents the thickness of the insulating layer. 6. The design method of a pressure sensor simulation system with variable dielectric constant according to claim 5, characterized in that the two flexible electrodes have the same structure, and both of the two flexible electrodes are used to sense pressure and produce deformation. , the insulating layer is attached to one side of the two flexible electrodes located in the chamber, and the thickness of the insulating layer on the two flexible electrodes is equal. 7. The design method of a pressure sensor simulation system with variable dielectric constant according to claim 6, characterized in that the expression of the contact area output capacitance C _t is rewritten as: Taking the differential of the contact area radius a _t for C _t we can get: The contact area radius a _t is a function of pressure P. Under the condition that the contact area output capacitance C _t and pressure P change linearly, the contact area radius a _t and pressure P need to satisfy a linear functional relationship, so the above formula is further rewritten as: but: in, Represents the output sensitivity of the contact area of the pressure sensor; for the contact area, r= _at , then the above formula can be simplified to: In the formula, D represents the bending stiffness of the deformation zone, and g represents the height of the chamber. 8. The design method of a pressure sensor simulation system with variable dielectric constant according to claim 5, characterized in that one of the flexible electrodes is used to sense pressure and produce deformation, and the other flexible electrode communicates with the outside world through a substrate. Isolated from pressure, the insulating layer is disposed on a flexible electrode connected to the substrate. 9. The design method of a pressure sensor simulation system with variable dielectric constant according to claim 8, characterized in that the derivation process of the relative dielectric constant ε _(r) includes the following steps: Rewrite the expression of output capacitance C _t as: Taking the differential of the contact area radius a _t for C _t we can get: The radius of the contact area a _t is a function of the pressure P. Under the condition that the output capacitance of the contact area changes linearly with the pressure, the above equation is further rewritten as: but: in, Represents the output sensitivity of the contact area of the pressure sensor; for the contact area, r= _at , then the above formula can be simplified to: In the formula, D represents the bending stiffness of the deformation zone, and g represents the height of the chamber. 10. A pressure sensor simulation system with variable dielectric constant, characterized by including: Basic model: The basic model includes a support frame and electrodes. The basic model includes a support frame and two flexible electrodes. The support frame surrounds a cylindrical chamber with openings at both ends. The two flexible electrodes cover and The openings at both ends of the chamber are completely closed, and the chamber is set to a vacuum state; the two flexible electrodes are spaced apart to form a capacitor, at least one of the flexible electrodes is used to sense pressure and produce deformation, and at least one of the flexible electrodes is located A film-like insulating layer is attached to one side of the chamber; Calculation module: used to set the dielectric constant of the insulating layer to be variable, using ε _(r) to represent the relative dielectric constant of the position on the insulating layer at a distance r from the center of the circle, and construct the basic model in the contact state The expression of the output capacitance, wherein the output capacitance includes the contact area output capacitance and the non-contact area output capacitance, and based on the linear change of the contact area output capacitance and pressure, the expression of the relative dielectric constant ε _(r) is derived; Parameter setting module: used to set the dielectric constant at any position on the insulating layer according to the expression of ε _(r) , complete the construction of the basic model, conduct simulation tests on the pressure sensor simulation system, and measure Performance, optimize and adjust the attribute parameters of the basic model according to the test results to obtain the final simulation system.