A microwave resonance pressure sensor combined with PDMS pressure unit

Abstract

The present invention relates to a microwave resonant pressure sensor combined with a PDMS pressure unit, and belongs to the field of microwave sensing technology. The present invention forms a special microwave resonator structure by arranging an enhanced capacitor with a double-layer spiral complementary structure and an interdigital capacitor with a fork-type complementary structure to cooperate with an input port and an output port, so that the effective plane is expanded in three-dimensional space, the surface area of ​​the capacitor plate is increased, thereby increasing the capacitance, and being more conducive to the adsorption and desorption process of electrons on the electrode surface.

Description

Technical Field

[0001] The invention relates to a microwave resonance pressure sensor combined with a PDMS pressure unit, belonging to the technical field of microwave sensing. Background Art

[0002] In recent years, with the rapid development of the Internet of Things, artificial intelligence and new material technology, microwave pressure sensors have gradually entered the intelligent stage, and wearable devices have gradually entered people's field of vision.

[0003] With the development of micro-electromechanical systems (MEMS), a variety of silicon-based micro-nano sensors have been developed for use in wearable devices. These silicon-based sensors have good performance. However, these sensors lack deformation ability, and their rigidity and brittleness make them unable to fit tightly with soft human skin, thus limiting their ability to accurately collect various signals on the human body surface as wearable devices.

[0004] Although some micro-nano sensors have been manufactured using MEMS technology, such as CN117547305A shows a flexible ultrasonic blood pressure measurement device and preparation method integrating a MEMS pressure sensor, which are used to monitor human physiological signals, including smart bracelets on the market that integrate multiple sensors such as magnetic speed sensors, optical heart rate sensors, and temperature sensors. However, such products lack flexibility and may cause discomfort when worn for a long time. This problem has not been effectively solved.

[0005] Although existing nanomaterials and flexible electronic technologies will drive microwave pressure sensors toward ultra-sensitivity and miniaturization, especially in wearable devices and implantable medical devices, microwave pressure sensor devices that can solve the problem of balancing flexibility, wearability and accuracy have not yet been found. There are only adjustable range capacitive flexible pressure sensors and preparation methods disclosed in CN113091961A that can adjust the range of the flexible pressure sensor to change the accuracy, but they cannot be miniaturized because the internal metal coil and excitation coil layer limit the size.

[0006] In addition, the prior art also includes an intracranial pressure sensor, a detection device, and a preparation method proposed in CN108209900A, in which the inductor and the capacitor are independent structures, which increases the manufacturing cost and the device volume and reduces the installation flexibility. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a microwave resonance pressure sensor combined with a PDMS pressure unit, comprising:

[0008] A substrate carries a microwave resonator, wherein the microwave resonator comprises an input port and an output port, wherein the input port is connected to the output port through an enhanced capacitor and an interdigital capacitor in sequence, wherein the enhanced capacitor has a double-layer spiral complementary structure, so as to maximize self-inductance and achieve high area efficiency with a high coupling coefficient; the interdigital capacitor comprises an interdigital sensing electrode connected to the output port, and an interdigital excitation electrode connected to the enhanced capacitor, wherein the interdigital sensing electrode and the interdigital excitation electrode intersect each other to form a forked complementary structure, wherein both the interdigital sensing electrode and the interdigital excitation electrode have parasitic series inductance and resistance and can generate a resonance effect without externally connecting other inductors, so as to improve detection speed and reaction sensitivity;

[0009] The force-bearing plate is movably connected to the substrate, and the force-bearing plate is embedded with a PDMS pressure unit. When the pressure-bearing plate is subjected to pressure, it will move toward a direction close to the substrate.

[0010] Furthermore, the double-layer spiral complementary structure of the enhanced capacitor is composed of two metal sheets that are wound into a spiral and then interlaced with each other in a gap, and the winding direction is counterclockwise.

[0011] Furthermore, two metal sheets are respectively arranged in planes of low height to form a hierarchical structure of upper and lower layers, including an upper metal sheet and a lower metal sheet connected between layers through a connecting bridge, and the upper metal sheet and the lower metal sheet are respectively connected to the input port and the interdigital capacitor.

[0012] Furthermore, two metal sheets wound into a spiral and interlaced in the gap are respectively a spiral excitation electrode and a spiral sensing electrode. The plates of the spiral excitation electrode spiral counterclockwise inward at equal intervals from the input port, and the plates of the spiral sensing electrode spiral clockwise outward at equal intervals, followed by a cross-finger capacitor.

[0013] Furthermore, the forked sensing electrode is a fork-shaped structure, including a sensing connection end and a plurality of sensing strip electrodes equidistantly arranged on the connection end; the forked excitation electrode is also a forked structure, including an excitation connection end and a plurality of excitation strip electrodes equidistantly arranged on the connection end; the width of the forked sensing strip electrode is equal to the width of the forked excitation strip electrode. The forked sensing electrodes and the forked excitation electrodes are interpolated with each other to form a forked complementary structure, and adjacent sensing strip electrodes and excitation strip electrodes are a group periodically arranged in the same plane. The advantage of setting up the forked capacitor in this way is that the structure is stable, and its performance changes relatively little under the influence of environmental factors such as temperature and humidity changes, and it can maintain good stability.

[0014] The end surface of the PDMS pressure unit close to the substrate is provided with a ring-shaped groove adapted to the double-layer spiral complementary structure and a strip array groove adapted to the fork-shaped complementary structure. When the force plate is pressed downward, the PDMS pressure unit can be accurately embedded in the gap of the enhanced capacitor and the gap of the forked capacitor through the ring-shaped groove and the strip array groove, thereby squeezing out the air in the gap between the plates, changing the dielectric constant between the spiral sensing electrode and the spiral excitation electrode, and between the forked sensing electrode and the forked excitation electrode, thereby changing the capacitance value of the enhanced capacitor and the forked capacitor, and causing a corresponding change in the frequency response of the microwave resonator.

[0015] In one embodiment of the present invention, the microwave resonant pressure sensor combined with the PDMS pressure unit can also be used in pressure detection: the pressure module is used in the COMSOL software to add a mechanical physical field, and the displacement change law diagram of the force-bearing plate under different pressures is calculated through a steady-state solver; the displacement change law curve of the force-bearing plate under different pressures is combined with the transmission characteristic curve of the microwave resonator at different displacement nodes to obtain the pressure parameters corresponding to the resonant frequency one by one, thereby obtaining the precise value of the pressure acting on the force-bearing plate. For example, by placing one side of the PDMS pressure unit of the pressure sensor on the inner side of the wrist near the artery, the physiological dynamic parameters are converted into electrical signals of changes in the resonant frequency curve, and then connected to the analog-to-digital conversion circuit, and the calculated heart rate results are displayed to the user in the form of numbers, charts (such as heart rate curves), etc. through the display screen of the data processing equipment; for another example, the method of using this application to monitor respiratory pressure in a ventilator, the microwave resonant pressure sensor combined with the PDMS pressure unit is bonded to the airflow duct of the ventilator by an adhesive and packaged, and the dielectric constant changes between the plates of the enhanced capacitor and the interdigital capacitor in the microwave resonator and the resonant frequency of the microwave resonator caused by the changes in respiratory pressure are measured by means of the measurement circuit and HFSS software to accurately measure the required respiratory pressure.

[0016] Beneficial effects of the present invention:

[0017] The present invention forms a special microwave resonator structure by arranging an enhanced capacitor with a double-layer spiral complementary structure and an interdigital capacitor with a fork-type complementary structure to cooperate with an input port and an output port, so that the effective plane is expanded in three-dimensional space, the surface area of ​​the capacitor plate is increased, thereby increasing the capacitance and being more conducive to the adsorption and desorption process of electrons on the electrode surface; wherein, the double-layer spiral complementary structure of the enhanced capacitor and the fork-type complementary structure of the interdigital capacitor can achieve a larger capacitance value on the same area, and are more suitable for integrated circuits and small electronic devices, so that the two capacitors show good capacitance characteristics, and can both generate resonance effects independently under the action of their own parasitic series inductance and resistance, and can both be used as pressure sensitive areas, and also realize synchronous dual-point measurement, can perform asynchronous measurement comparison, expand the measurement range of the device, and broaden the measurement method.

[0018] In addition, the force-bearing plate is equipped with a PDMS pressure unit. Due to the excellent flexibility and stretchability of the PDMS material, it is particularly suitable for wearable sensors or soft electronic devices. It is easier to bend and deform, and can even be worn on the human body surface for applications such as human physiological signal monitoring. Furthermore, the PDMS pressure unit has a ring groove that adapts to the double-layer spiral complementary structure and a strip array groove that adapts to the fork-type complementary structure. It can link the microwave resonator to change the capacitance value of the enhanced capacitor and the fork-finger capacitor, so that the frequency response of the microwave resonator changes accordingly.

[0019] In general, the present invention solves the problems of inconvenience in human wearing, insufficient accuracy, limited application directions, large size and limited medical detection applications. It has the advantages of easy processing and low cost. The design of the connecting bridge enhanced capacitor and the interdigital capacitor of the double-layer spiral structure makes the sensor miniaturized, and the sensor can be integrated into small devices. It is suitable for the rapidly developing smart sensor networks and wearable devices. The use of PDMS as a pressure unit can enhance the safety and reliability of the sensor in the biomedical field, such as monitoring pressure changes inside or outside the body, which is of great significance to the development of medical equipment and biosensors.

[0020] In addition, the present invention can also be integrated with other functional modules, such as combining with microfluidic channels to detect pressure changes in fluids, or integrating with acoustic devices to achieve joint measurement of sound waves and pressure. This multifunctional integration enables microwave pressure sensors to be widely used in more complex environments and application scenarios, such as medical testing, environmental monitoring, and industrial automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure in one embodiment of the present invention.

[0022] Figure 2A top view of the structure of a substrate in one embodiment of the present invention.

[0023] Figure 3 FIG. 1 is a top view of the structure of an interdigital capacitor in one embodiment of the present invention.

[0024] Figure 4 It is a schematic diagram of the three-dimensional structure of a load-bearing plate in one embodiment of the present invention.

[0025] Figure 5 It is a curve chart of simulation results of a microwave resonator in one embodiment of the present invention.

[0026] In the figure, 1, connection bridge; 2, input port; 3, output port; 4, enhanced capacitor; 5, interdigital capacitor. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] like Figure 1-Figure 5 The present invention provides a microwave resonance pressure sensor combined with a PDMS pressure unit, comprising:

[0030] Base plate, located Figure 1A microwave resonator is carried below the microwave resonator, the microwave resonator comprising an input port 2 and an output port 3, the input port 2 is connected to the output port 3 via an enhanced capacitor 4 and a forked capacitor 5 in sequence, the enhanced capacitor 4 has a double-layer spiral complementary structure, to maximize the self-inductance and achieve a high area efficiency with a high coupling coefficient; the forked capacitor 5 has a forked sensing electrode connected to the output port 3 and a forked excitation electrode connected to the enhanced capacitor 4, the forked sensing electrodes and the forked excitation electrodes intersect each other to form a forked complementary structure, the forked sensing electrodes and the forked excitation electrodes both have parasitic series inductance and resistance and can produce a resonance effect without externally connecting other inductors, to improve the detection speed and reaction sensitivity;

[0031] Load plate, located at Figure 1 The pressure plate is movably connected to the substrate, and the pressure plate is embedded with a PDMS pressure unit. When the pressure plate is subjected to pressure, it will move toward the direction close to the substrate.

[0032] Furthermore, if Figure 2 The double-layer spiral complementary structure of the enhanced capacitor 4 is composed of two metal sheets wound into a spiral shape and interlaced with each other in the gap, and the winding direction is counterclockwise. The two metal sheets are respectively arranged in a plane of low height to form a hierarchical structure of upper and lower layers, including an upper metal sheet and a lower metal sheet connected between layers through a connecting bridge, and the upper metal sheet and the lower metal sheet are respectively connected to the input port 2 and the interdigital capacitor 5.

[0033] Furthermore, two metal sheets wound into a spiral and interlaced in the gap are respectively a spiral excitation electrode and a spiral sensing electrode. The plates of the spiral excitation electrode spiral counterclockwise inward at equal intervals from the input port, and the plates of the spiral sensing electrode spiral clockwise outward at equal intervals, followed by a cross-finger capacitor.

[0034] Furthermore, the forked sensing electrode is a fork-shaped structure, including a sensing connection end and a plurality of sensing strip electrodes equidistantly arranged on the connection end; the forked excitation electrode is also a forked structure, including an excitation connection end and a plurality of excitation strip electrodes equidistantly arranged on the connection end; the width of the forked sensing strip electrode is equal to the width of the forked excitation strip electrode. The forked sensing electrodes and the forked excitation electrodes are interpolated with each other to form a forked complementary structure, and adjacent sensing strip electrodes and excitation strip electrodes are a group periodically arranged in the same plane. The advantage of setting up the forked capacitor in this way is that the structure is stable, and its performance changes relatively little under the influence of environmental factors such as temperature and humidity changes, and it can maintain good stability.

[0035] like Figure 3As shown, the length of each sensing strip electrode / excitation strip electrode is set to L, and the center distance between adjacent electrodes of the same sex (between two adjacent sensing strip electrodes or between two adjacent excitation strip electrodes) is λ. Since the lengths and center distances of the sensing strip electrodes and the excitation strip electrodes are equal, a sensing strip electrode and its most adjacent excitation strip electrode can be set as a group, and each group is periodically arranged on the plane where the substrate is located in an equidistant manner.

[0036] The end surface of the PDMS pressure unit close to the substrate is provided with a ring-shaped groove adapted to the double-layer spiral complementary structure and a strip array groove adapted to the fork-shaped complementary structure. When the force plate is pressed downward, the PDMS pressure unit can be accurately embedded in the gap of the enhanced capacitor and the gap of the forked capacitor through the ring-shaped groove and the strip array groove, thereby squeezing out the air in the gap between the plates, changing the dielectric constant between the spiral sensing electrode and the spiral excitation electrode, and between the forked sensing electrode and the forked excitation electrode, thereby changing the capacitance value of the enhanced capacitor and the forked capacitor, and causing a corresponding change in the frequency response of the microwave resonator.

[0037] The formed microwave resonance type pressure sensor combined with the PDMS pressure unit is a flexible sensor.

[0038] In addition, the microwave resonant pressure sensor combined with the PDMS pressure unit can also be used in pressure detection: use the pressure module in the COMSOL software to add a mechanical physical field, and calculate through the steady-state solver to obtain the displacement change law diagram of the force-bearing plate under different pressures; combine the displacement change law curve of the force-bearing plate under different pressures with the transmission characteristic curve of the microwave resonator at different displacement nodes to obtain the pressure parameters corresponding to the resonant frequency, thereby obtaining the precise value of the pressure acting on the force-bearing plate.

[0039] The simulation results of microwave resonator are shown in Figure 2. Figure 5 As shown, from the reflection parameter S11 curve 6, it can be seen that the resonant frequency of the resonator is about 7.45GHz, and the reflection coefficient at the resonance point is about -16.4dB, indicating that the impedance matching of the resonator is good. The 3dB frequency band of the resonator is about 4.96GHz-10.13GHz, and the bandwidth is about 5.17GHz, showing good wide-band working characteristics. Observing the transmission parameter S21 curve 7, within the corresponding working frequency band, the average value of the transmission parameter is greater than -10dB, indicating that the signal transmission loss is small and the transmission characteristics meet the application standards.

[0040] The following examples illustrate the application of a microwave resonance pressure sensor combined with a PDMS pressure unit in pressure detection.

[0041] Example 1

[0042] Wearable device uses the application to detect physiological dynamic parameters:

[0043] Wearable devices may include wearable sports intelligent detection devices such as sports watches and sports bracelets.

[0044] By placing one side of the pressure sensor PDMS pressure unit on the inside of the wrist close to the artery, the physiological dynamic parameters are converted into electrical signals of changes in the resonant frequency curve, and then connected to the analog-to-digital conversion circuit. The calculated heart rate results are displayed to the user in the form of numbers, charts (such as heart rate curves), etc. through the display screen of the data processing equipment. The measurable physiological dynamic parameters include pulse, blood pressure, heart rate, etc.

[0045] Since PDMS has high elasticity due to its low Young's modulus, as well as good flexibility and biocompatibility, the microwave resonant pressure sensor combined with the PDMS pressure unit can be designed on the curved part of the wrist as required. In addition, the material of the flexible sensor exhibits good repeatability and recovery when subjected to multiple pressure applications and releases. In addition, the inside of a watch or bracelet is selected as the installation location for the microwave resonant pressure sensor combined with the PDMS pressure unit, and it is connected to the built-in circuit board (PCB). It is also possible to consider using waterproof and sweat-resistant materials for packaging.

[0046] During the user's exercise, the expansion and pulsation of the radial artery at the wrist moves the force plate downward, and the PDMS pressure unit is embedded in the gap between the plates of the enhanced and interdigitated capacitors, increasing the dielectric constant of the medium between the plates, reducing the resonant frequency and shifting the resonant curve to the left. When the radial artery at the wrist contracts to a normal state, the PDMS flexible material returns to its initial state, and the resonant frequency and curve are restored. Each decrease in the resonant frequency is reflected as a jump in the digital signal, and the corresponding heart rate can be calculated at a fixed time interval.

[0047] Example 2

[0048] How to use the app to monitor respiratory pressure in a ventilator:

[0049] The microwave resonance pressure sensor combined with the PDMS pressure unit is bonded to the airflow duct of the ventilator by an adhesive and packaged, and the sensor is packaged and protected by waterproof and antifouling materials.

[0050] Since changes in breathing pressure will cause changes in the dielectric constant between the capacitor plates of the resonator, thereby affecting the resonant frequency of the resonator, the required breathing pressure can be accurately measured by using measurement circuits and HFSS software for simulation data analysis.

[0051] During the detection process, the pressure in the ventilator airflow pipeline will change due to the patient's breathing. When the patient exhales, the pressure in the pipeline increases, the pressure sensor force plate moves down, and the PDMS pressure unit is accurately embedded in the gap of the enhanced capacitor and the gap of the interdigital capacitor through the ring groove of the ring layer and the strip array groove. The dielectric constant between the plates increases and the resonant frequency decreases; when the patient inhales, the pressure in the pipeline decreases, the pressure sensor force plate moves up, the dielectric constant between the plates decreases, and the resonant frequency increases. When the patient breathes normally, the resonant frequency will fluctuate periodically. The microwave resonant pressure sensor combined with the PDMS pressure unit can provide real-time and accurate monitoring data to help doctors make more accurate diagnosis and treatment decisions. In addition, its excellent stability and biocompatibility enable it to meet the strict requirements of medical equipment.

[0052] Example 3

[0053] Use microwave resonant pressure sensors combined with PDMS pressure cells to measure pressure in mechanical equipment or changing forces during material transportation:

[0054] The thickness and structure of the PDMS pressure unit on the force plate are designed by gradient thickness, so that it can withstand large pressure changes and maintain sensitivity. The gradient thickness design means that the thickness of the PDMS pressure unit gradually increases from the pressure receiving surface to the fixed support surface. This design can make the pressure more reasonably distributed during the transmission process; near the pressure receiving surface, the thinner PDMS can quickly respond to pressure changes and effectively transmit the pressure signal to the inside; as the thickness increases, the thicker part inside can withstand greater pressure.

[0055] The flexible nature of the PDMS pressure cell enables it to bend and adapt to the curved surfaces of various industrial equipment. Sensors are installed at key locations of pressure pipes, robot arm joints, or material conveyor belts. The microwave resonant pressure sensor combined with the PDMS pressure cell monitors the pressure status of the equipment in real time, which can warn of potential failures, help companies achieve predictive maintenance, reduce equipment downtime, and reduce maintenance costs.

[0056] The high sensitivity and stability of the microwave resonant pressure sensor combined with the PDMS pressure unit enable more accurate control of industrial automation systems, improve production efficiency, and reduce material waste. In high-pressure or hazardous material application scenarios, the real-time monitoring and feedback of the microwave resonant pressure sensor combined with the PDMS pressure unit can greatly improve the safety of industrial operations and reduce the risk of accidents; and it also has good flexibility, high temperature resistance, and chemical corrosion resistance, and can adapt to the harsh conditions of the industrial environment.

[0057] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A microwave resonant pressure sensor combined with a PDMS pressure unit, characterized in that: include: A substrate carries a microwave resonator, wherein the microwave resonator comprises an input port and an output port, wherein the input port is connected to the output port through an enhanced capacitor and an interdigital capacitor in sequence, wherein the enhanced capacitor has a double-layer spiral complementary structure; the interdigital capacitor comprises an interdigital sensing electrode connected to the output port and an interdigital excitation electrode connected to the enhanced capacitor, wherein the interdigital sensing electrodes and the interdigital excitation electrodes intersect each other to form a forked complementary structure, wherein both the interdigital sensing electrodes and the interdigital excitation electrodes have parasitic series inductance and resistance and can generate a resonance effect without externally connecting other inductors; The force-bearing plate is movably connected to the substrate, and the force-bearing plate is embedded with a PDMS pressure unit. When the pressure-bearing plate is subjected to pressure, it will move toward a direction close to the substrate.

2. A microwave resonant pressure sensor combined with a PDMS pressure unit according to claim 1, characterized in that: The double-layer spiral complementary structure of the enhanced capacitor is composed of two metal sheets that are wound into a spiral and then interlaced with each other in a gap, and the winding direction is counterclockwise.

3. A microwave resonant pressure sensor combined with a PDMS pressure unit according to claim 2, characterized in that: Two metal sheets are respectively arranged in planes of low height to form a hierarchical structure of upper and lower layers, including an upper metal sheet and a lower metal sheet connected between layers through a connecting bridge, wherein the connecting bridge is a bridge structure composed of metal wires suspended on a substrate and separated from the substrate by air; the upper metal sheet and the lower metal sheet are respectively connected to an input port and a finger capacitor.

4. The microwave resonance pressure sensor combined with the PDMS pressure unit according to claim 3, characterized in that: Two metal sheets wound into a spiral and interlaced in the gap are respectively a spiral excitation electrode and a spiral sensing electrode. The plates of the spiral excitation electrode spiral counterclockwise inward at equal intervals from the input port, and the plates of the spiral sensing electrode spiral clockwise outward at equal intervals, followed by a cross-finger capacitor.

5. The microwave resonance pressure sensor combined with a PDMS pressure unit according to claim 4, characterized in that: The interdigitated sensing electrode is a fork-shaped structure, including a sensing connection end and a plurality of sensing strip electrodes arranged at equal intervals on the connection end; the interdigitated excitation electrode is also a fork-shaped structure, including an excitation connection end and a plurality of excitation strip electrodes arranged at equal intervals on the connection end; the width of the interdigitated sensing strip electrodes is equal to the width of the interdigitated excitation strip electrodes.

6. The microwave resonance pressure sensor combined with a PDMS pressure unit according to claim 5, characterized in that: The interdigitated sensing electrodes and the interdigitated excitation electrodes are interpolated with each other to form a forked complementary structure, and adjacent sensing strip electrodes and excitation strip electrodes are arranged periodically in a group in the same plane.

7. The microwave resonance pressure sensor combined with a PDMS pressure unit according to claim 6, characterized in that: The end surface of the PDMS pressure unit close to the substrate is provided with a ring-shaped groove adapted to the double-layer spiral complementary structure and a strip array groove adapted to the fork-shaped complementary structure. When the force plate is pressed downward, the PDMS pressure unit can be accurately embedded in the gap of the enhanced capacitor and the gap of the forked capacitor through the ring-shaped groove and the strip array groove, thereby squeezing out the air in the gap between the plates, changing the dielectric constant between the spiral sensing electrode and the spiral excitation electrode, and between the forked sensing electrode and the forked excitation electrode, thereby changing the capacitance value of the enhanced capacitor and the forked capacitor, and causing a corresponding change in the frequency response of the microwave resonator.

8. Application of the microwave resonant pressure sensor combined with the PDMS pressure unit according to any one of claims 1 to 7 in pressure detection, characterized in that: The pressure module is used to add mechanical physical fields in the COMSOL software, and the displacement change law diagram of the force-bearing plate under different pressures is calculated through the steady-state solver. The displacement change law curve of the force-bearing plate under different pressures is combined with the transmission characteristic curve of the microwave resonator at different displacement nodes to obtain the pressure parameters corresponding to the resonant frequency, thereby obtaining the precise value of the pressure acting on the force-bearing plate.

9. A method for detecting physiological dynamic parameters using the application of claim 8 by a wearable device, characterized in that: By placing one side of the pressure sensor PDMS pressure unit on the inside of the wrist close to the artery, the physiological dynamic parameters are converted into electrical signals of changes in the resonant frequency curve, and then connected to the analog-to-digital conversion circuit, the calculated heart rate results are displayed to the user in digital and graphical form through the display screen of the data processing equipment.

10. The method for monitoring respiratory pressure in a ventilator using the application of claim 8, characterized in that: The microwave resonant pressure sensor combined with the PDMS pressure unit is bonded to the airflow duct of the ventilator by an adhesive and encapsulated. With the help of a measurement circuit and HFSS software, the changes in the dielectric constant between the plates of the enhanced capacitor and the interdigital capacitor in the microwave resonator and the resonant frequency of the microwave resonator caused by the changes in the respiratory pressure can be used to accurately measure the required respiratory pressure.

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