Piezoelectric self-feedback excitation type micro electric field sensor, electric field detection method, and sensor

Abstract

The present disclosure provides a piezoelectric self-feedback excitation type micro electric field sensor, an electric field detection method and a sensor, and is applied to the technical field of electric field sensors. The piezoelectric self-feedback excitation type micro electric field sensor comprises: a substrate for supporting a vibration pickup reference structure, a piezoelectric driving structure, a mutual shielding electric field sensing structure and an elastic beam; the piezoelectric driving structure is used for deforming the piezoelectric driving structure to make the elastic beam vibrate when a driving voltage is applied to the piezoelectric driving structure; the mutual shielding electric field sensing structure is used for outputting a differential form of a sensing current signal in response to the vibration of the elastic beam, so as to suppress common mode noise and detect the amplitude strength of the electric field to be measured; the vibration pickup reference structure is used for outputting a reference current signal in response to the vibration of the elastic beam, so as to adjust the size of the driving voltage, so that the output sensitivity of the piezoelectric self-feedback excitation type micro electric field sensor is a predetermined value.

Description

Technical Field

[0001] This disclosure relates to the field of electric field sensor technology, and more specifically to a piezoelectric self-feedback excitation micro electric field sensor, an electric field detection method, and a sensor. Background Technology

[0002] Electric field detection technology is widely used in various fields such as aerospace, meteorology, power, hazardous chemicals, and industrial production. Electric field sensors based on microelectromechanical systems (MEMS) have advantages such as small size, light weight, and low cost, making them suitable for electric field detection. Existing MEMS-based electric field sensors generally use electrostatic actuation to modulate the electric field; however, electrostatic actuation has weak driving capability and is prone to interference with the measured electric field, thus failing to meet the high requirements for existing electric field sensors.

[0003] In the process of realizing the above-mentioned inventive concept, the inventors discovered that the existing electric field sensors suffer from low stability in output sensitivity and output resolution due to the influence of the driving method, resulting in low stability in the detection of the electric field to be measured. Summary of the Invention

[0004] In view of the above problems, this disclosure provides a piezoelectric self-feedback excitation micro electric field sensor, an electric field detection method, and a sensor.

[0005] According to a first aspect of this disclosure, a piezoelectric self-feedback excitation type micro electric field sensor is provided, comprising: a substrate for supporting a vibration pickup reference structure, a piezoelectric driving structure, a mutually shielded electric field sensing structure, and an elastic beam; a piezoelectric driving structure fixed to both sides of the vibration pickup reference structure on the substrate by the elastic beam, wherein the piezoelectric driving structure deforms when a driving voltage is applied to the piezoelectric driving structure, thereby causing the elastic beam to vibrate; a mutually shielded electric field sensing structure disposed above the substrate, wherein in response to the vibration of the elastic beam, the mutually shielded electric field sensing structure outputs a differential form of induced current signal to suppress common-mode noise and detect the amplitude intensity of the electric field to be measured; and a vibration pickup reference structure disposed on both sides of the mutually shielded electric field sensing structure, wherein in response to the vibration of the elastic beam, the vibration pickup reference structure outputs a reference current signal to adjust the magnitude of the driving voltage so that the output sensitivity of the piezoelectric self-feedback excitation type micro electric field sensor is a predetermined value.

[0006] According to embodiments of this disclosure, the mutually shielded electric field sensing structure includes a movable electric field sensing electrode and a fixed electric field sensing electrode. The movable electric field sensing electrode is suspended on the substrate by an elastic beam. In response to the vibration of the elastic beam, based on the principle of charge induction, the movable electric field sensing electrode vibrates in the vertical direction relative to the substrate, causing a relative change in position between the movable electric field sensing electrode and the fixed electric field sensing electrode, and outputting a differential induced current signal. The fixed electric field sensing electrode is located above the substrate and is disposed opposite to the movable electric field sensing electrode. It provides a reference position corresponding to the position of the movable electric field sensing electrode when the movable electric field sensing electrode vibrates, and together with the movable electric field sensing electrode, outputs a differential induced current signal.

[0007] According to embodiments of this disclosure, the vibration pickup reference structure includes a movable reference electrode and a fixed vibration pickup electrode. The movable reference electrode is suspended on the substrate by an elastic beam and is located on both sides of the mutually shielded electric field induction structure. In response to the vibration of the elastic beam, the movable reference electrode generates vibration in the vertical direction relative to the substrate, thereby causing a relative change in position between the movable reference electrode and the fixed vibration pickup electrode, and changing the capacitance between the movable reference electrode and the fixed vibration pickup electrode. The fixed vibration pickup electrode is fixed above the substrate and is disposed opposite to the movable reference electrode. It is used to provide a reference position corresponding to the position of the movable reference electrode when the movable reference electrode vibrates, and outputs a reference current signal according to the amount of capacitance change between the movable reference electrode and the fixed vibration pickup electrode.

[0008] According to embodiments of this disclosure, in the substrate, the region corresponding to the mutually shielded electric field induction structure and the vibration pickup reference structure is a hollow structure; the electric field induction fixed electrode is located above the substrate, including: one end of the electric field induction fixed electrode is connected to the substrate and receives a supporting force provided by the substrate, so that the structure of the electric field induction fixed electrode except for the end connected to the substrate is suspended; the vibration pickup fixed electrode is fixed above the substrate, including: one end of the vibration pickup fixed electrode is connected to the substrate and receives a supporting force provided by the substrate, so that the structure of the vibration pickup fixed electrode except for the end connected to the substrate is suspended.

[0009] According to embodiments of this disclosure, the piezoelectric drive structure includes a drive electrode layer and a piezoelectric layer, and the resonator is composed of an electric field-sensing movable electrode and a movable reference electrode; the drive electrode layer includes a first sub-drive electrode layer and a second sub-drive electrode layer, the second sub-drive electrode layer being fixed to the elastic beam through an insulating layer, the drive electrode layer being used to drive the piezoelectric layer to deform in response to a received drive voltage; the piezoelectric layer is disposed between the first sub-drive electrode layer and the second sub-drive electrode layer, and is used to cause the piezoelectric material in the piezoelectric layer to deform in response to the drive electrode layer, so that the elastic beam vibrates, thereby driving the resonator to vibrate.

[0010] According to embodiments of this disclosure, the material used to prepare the insulating layer includes at least one of the following: silicon dioxide, silicon nitride; the driving electrode layer is a conductor, and the conductor material used to prepare the driving electrode layer includes at least one of the following: platinum, gold, silver, aluminum, copper; the piezoelectric layer is obtained by sputtering or sol-gel deposition, and the material used to prepare the piezoelectric layer includes at least one of the following: aluminum nitride, zinc oxide, lead titanate, barium titanate, lead zirconate titanate, niobium-doped strontium titanate, niobium-doped titanium dioxide with a high piezoelectric coefficient.

[0011] According to embodiments of this disclosure, the materials used to prepare the substrate include at least one of the following: silicon, ceramics, glass, and other organic materials.

[0012] A second aspect of this disclosure provides an electric field detection method, comprising: placing a piezoelectric self-feedback excitation micro electric field sensor in an electric field to be measured; applying a driving voltage to the driving electrode layer of the piezoelectric self-feedback excitation micro electric field sensor to cause an elastic beam to vibrate; responding to the vibration of the elastic beam, a relative change in position occurs between a movable reference electrode and a fixed pickup electrode based on a change in capacitance, and the fixed pickup electrode outputs a reference current signal; inputting the reference current signal into a feedback circuit; adjusting the magnitude of the driving voltage based on the reference current signal; applying the adjusted driving voltage to the driving electrode layer of the piezoelectric self-feedback excitation micro electric field sensor to obtain a piezoelectric self-feedback excitation micro electric field sensor with constant sensitivity; responding to the vibration of the elastic beam of the piezoelectric self-feedback excitation micro electric field sensor with constant sensitivity, and based on the principle of charge induction, using the relative change in position between the electric field-sensing movable electrode and the electric field-sensing fixed electrode, outputting a differential form of induced current signal; and obtaining the amplitude intensity of the electric field to be measured based on the differential form of the induced current signal.

[0013] A third aspect of this disclosure provides an electric field sensor, comprising: a piezoelectric self-feedback excitation micro electric field sensor with the structure described above, or a piezoelectric self-feedback excitation micro electric field sensor obtained by the preparation method described above.

[0014] According to embodiments of this disclosure, the electric field sensor further includes a two-dimensional or three-dimensional electric field sensor composed of multiple sensor-sensitive structures, for measuring two-dimensional or three-dimensional electric fields or voltages.

[0015] According to the piezoelectric self-feedback excitation micro electric field sensor, electric field detection method, and sensor disclosed herein, the piezoelectric self-feedback excitation micro electric field sensor includes a substrate, a piezoelectric driving structure, a mutually shielded electric field sensing structure, and a vibration pickup reference structure. The piezoelectric driving structure, the mutually shielded electric field sensing structure, and the vibration pickup reference structure are all disposed above the substrate. The piezoelectric driving structure is disposed on both sides of the substrate, and the mutually shielded electric field sensing structure and the vibration pickup reference structure are located between the two piezoelectric driving structures. The mutually shielded electric field sensing structure is located above the center of the substrate, and the vibration pickup reference structure is located on both sides of the mutually shielded electric field sensing structure. By applying a driving voltage only to the piezoelectric driving structure, the internal material of the piezoelectric driving structure deforms, thereby causing the elastic beam connected to the piezoelectric driving structure to vibrate. While reducing the driving voltage and decreasing coupling noise interference, the mutually shielded electric field sensing structure and the vibration pickup reference structure connected to the elastic beam vibrate perpendicular to the substrate direction, thereby improving the modulation capability of the electric field.

[0016] According to embodiments of this disclosure, further, based on the principle of charge induction, the mutually shielded electric field induction structure outputs a differential induced current signal to facilitate the detection of the amplitude intensity of the electric field under test based on the magnitude of the induced current signal. Simultaneously, the differential induced current signal eliminates common-mode noise caused by external environmental influences, improving charge induction efficiency and enabling accurate detection of the electric field under test. Based on capacitance changes, the vibration pickup reference structure outputs a reference current signal to facilitate inputting the reference current signal to the feedback circuit, reducing the sensitivity drift of the piezoelectric self-feedback excitation micro electric field sensor and minimizing the influence of ambient temperature on resonance. Thus, the driving voltage applied to the piezoelectric driving structure can be adjusted according to the reference current signal, improving the stability of the output sensitivity of the piezoelectric self-feedback excitation micro electric field sensor while maintaining the sensor in a continuous resonant state, achieving closed-loop resonator operation, improving the efficiency and accuracy of electric field detection, and maintaining the high output sensitivity and high resolution stability of the piezoelectric self-feedback excitation micro electric field sensor.

[0017] According to embodiments of this disclosure, the piezoelectric self-feedback excitation micro electric field sensor of this disclosure is applicable to electric field measurement environments in various fields, can accurately measure electric fields in various environments, is suitable for long-term stable measurement needs, and has a high degree of integration and application value. Attached Figure Description

[0018] The foregoing contents, as well as other objects, features, and advantages of this disclosure, will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0019] Figure 1A schematic diagram of the structure of a piezoelectric self-feedback excitation micro electric field sensor according to an embodiment of the present disclosure is shown.

[0020] Figure 2 A schematic diagram of the piezoelectric drive structure of a piezoelectric self-feedback excited micro electric field sensor according to an embodiment of the present disclosure is shown.

[0021] Figure 3 A schematic diagram of a piezoelectric self-feedback excited micro electric field sensor according to another embodiment of the present disclosure is shown;

[0022] Figure 4 A flowchart illustrating an electric field detection method according to an embodiment of the present disclosure is shown schematically.

[0023] Figure label:

[0024] The substrate 101, elastic beam 102, driving electrode layer 103, first sub-driving electrode layer 1031, second sub-driving electrode 1032, piezoelectric layer 104, insulating layer 105, strip-shaped electric field sensing movable electrode 106, electric field sensing fixed electrode 107, movable reference electrode 108, vibration pickup fixed electrode 109, and comb-shaped electric field sensing movable electrode 301. Detailed Implementation

[0025] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0026] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0027] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0028] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0029] In the technical solution of this invention, the user information (including but not limited to user personal information, user image information, user device information, such as location information) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, storage, use, processing, transmission, provision, disclosure, and application of related data all comply with relevant laws, regulations, and standards, take necessary confidentiality measures, do not violate public order and good morals, and provide corresponding operation entry points for users to choose to authorize or refuse.

[0030] Electric field detection technology is widely used in various fields such as aerospace, meteorology, power, hazardous chemicals, and industrial production. Electric field sensors based on Microelectromechanical Systems (MEMS) have advantages such as small size, light weight, and low cost, making them suitable for electric field detection. Existing MEMS-based electric field sensors generally use electrostatic actuation to modulate the electric field. However, electrostatic actuation suffers from weak driving capability and small oscillation amplitude, while novel thermal actuation methods have low energy efficiency, high temperature requirements, and limited applicability. These limitations prevent the existing electric field sensors from meeting the high requirements of current technology, resulting in low sensitivity and inaccurate electric field detection results.

[0031] Furthermore, researchers are conducting in-depth research on the driving methods of electric field sensors to meet the current high demands for such sensors. During the research process, they discovered that existing electric field sensors suffer from low stability in output sensitivity and resolution due to the influence of their driving methods, resulting in unstable detection of the electric field under test.

[0032] In view of this, embodiments of the present disclosure provide a piezoelectric self-feedback excitation type micro electric field sensor, comprising: a substrate for supporting a vibration pickup reference structure, a piezoelectric driving structure, a mutually shielded electric field sensing structure, and an elastic beam; a piezoelectric driving structure fixed to both sides of the vibration pickup reference structure on the substrate by the elastic beam, wherein the piezoelectric driving structure deforms when a driving voltage is applied to the piezoelectric driving structure, thereby causing the elastic beam to vibrate; a mutually shielded electric field sensing structure disposed above the substrate, wherein in response to the vibration of the elastic beam, the mutually shielded electric field sensing structure outputs a differential form of induced current signal to suppress common-mode noise and detect the amplitude intensity of the electric field to be measured; and a vibration pickup reference structure disposed on both sides of the mutually shielded electric field sensing structure, wherein in response to the vibration of the elastic beam, the vibration pickup reference structure outputs a reference current signal to adjust the magnitude of the driving voltage so that the output sensitivity of the piezoelectric self-feedback excitation type micro electric field sensor is a predetermined value.

[0033] The following will be through Figures 1-3 A detailed description is provided of the piezoelectric self-feedback excitation micro electric field sensor according to the disclosed embodiments.

[0034] According to embodiments of this disclosure, a piezoelectric self-feedback excitation micro electric field sensor may include a substrate, an elastic beam, a piezoelectric driving structure, a mutually shielded electric field sensing structure, and a vibration pickup reference structure.

[0035] According to embodiments of this disclosure, the substrate can be used to support a vibration pickup reference structure, a piezoelectric drive structure, a mutually shielded electric field sensing structure, and an elastic beam.

[0036] According to embodiments of this disclosure, a piezoelectric drive structure can be fixed to both sides of a vibration pickup reference structure on a substrate by an elastic beam, so that when a driving voltage is applied to the piezoelectric drive structure, the piezoelectric drive structure deforms, thereby causing the elastic beam to vibrate.

[0037] According to embodiments of this disclosure, a piezoelectric drive structure can be prepared using novel materials, reducing the driving voltage while minimizing coupling noise interference. This allows the mutually shielded electric field induction structure and the vibration pickup reference structure to move in the vertical direction relative to the substrate, improving the electric field modulation capability. Furthermore, since the piezoelectric drive structure is driven to vibrate based on a piezoelectric driving method, the driving voltage applied to the piezoelectric drive structure can be reduced.

[0038] According to embodiments of this disclosure, a mutually shielded electric field sensing structure can be disposed above a substrate. In response to the vibration of an elastic beam, the mutually shielded electric field sensing structure outputs a differential form of induced current signal to suppress common-mode noise and detect the amplitude intensity of the electric field under test.

[0039] According to an embodiment of this disclosure, the mutually shielded electric field induction structure is connected to the elastic beam, so that when the elastic beam vibrates, the mutually shielded electric field induction structure vibrates, and an induced current signal is output according to the principle of charge induction.

[0040] According to embodiments of this disclosure, when a driving voltage is applied to the piezoelectric drive structure, the piezoelectric drive structure drives the elastic beam to vibrate, and the mutually shielded electric field induction structure outputs a differential induced current signal. The amplitude of the power plant under test can be obtained based on the magnitude of the differential induced current signal. At the same time, common-mode noise can be suppressed based on the differential induced current signal, thereby improving charge induction efficiency.

[0041] According to embodiments of this disclosure, a vibration pickup reference structure can be disposed on both sides of a mutually shielded electric field induction structure. In response to the vibration of the elastic beam, the vibration pickup reference structure outputs a reference current signal to adjust the magnitude of the driving voltage so that the output sensitivity of the piezoelectric self-feedback excitation micro electric field sensor is a predetermined value.

[0042] According to embodiments of this disclosure, the vibration-sensing reference structure is connected to the elastic beam, so that when the elastic beam vibrates, the vibration-sensing reference structure vibrates and outputs a reference current signal based on the change in capacitance.

[0043] According to embodiments of this disclosure, based on a predetermined relationship between the resonant frequency, amplitude, and reference current signal, the reference current signal can be input to the feedback circuit, thereby achieving closed-loop self-excitation of the piezoelectric self-feedback excitation micro electric field sensor. This reduces the sensitivity drift of the piezoelectric self-feedback excitation micro electric field sensor, reduces the influence of temperature on the resonance, improves the resonance stability of the piezoelectric self-feedback excitation micro electric field sensor, and improves the stability of the output sensitivity of the piezoelectric self-feedback excitation micro electric field sensor, so that the output sensitivity of the piezoelectric self-feedback excitation micro electric field sensor can be a predetermined value, and the electric field can be detected under stable sensitivity.

[0044] According to embodiments of this disclosure, the predetermined relationship between the resonant frequency, amplitude, and reference current signal can be characterized as the magnitude of the reference current signal being proportional to the product of the resonant frequency and the resonant amplitude.

[0045] According to embodiments of this disclosure, a piezoelectric self-feedback excitation type micro electric field sensor includes a substrate, a piezoelectric driving structure, a mutually shielded electric field sensing structure, and a vibration pickup reference structure. The piezoelectric driving structure, the mutually shielded electric field sensing structure, and the vibration pickup reference structure are all disposed above the substrate. The piezoelectric driving structure is disposed on both sides of the substrate, and the mutually shielded electric field sensing structure and the vibration pickup reference structure are located between the two piezoelectric driving structures. The mutually shielded electric field sensing structure is located above the center of the substrate, and the vibration pickup reference structure is located on both sides of the mutually shielded electric field sensing structure. By applying a driving voltage only to the piezoelectric driving structure, the internal material of the piezoelectric driving structure deforms, thereby causing the elastic beam connected to the piezoelectric driving structure to vibrate. While reducing the driving voltage and decreasing coupling noise interference, the mutually shielded electric field sensing structure and the vibration pickup reference structure connected to the elastic beam vibrate perpendicular to the substrate direction, thereby improving the modulation capability of the electric field.

[0046] According to embodiments of this disclosure, further, based on the principle of charge induction, the mutually shielded electric field induction structure outputs a differential induced current signal to facilitate the detection of the amplitude intensity of the electric field under test based on the magnitude of the induced current signal. Simultaneously, the differential induced current signal eliminates common-mode noise caused by external environmental influences, improving charge induction efficiency and enabling accurate detection of the electric field under test. Based on capacitance changes, the vibration pickup reference structure outputs a reference current signal to facilitate inputting the reference current signal to the feedback circuit, reducing the sensitivity drift of the piezoelectric self-feedback excitation micro electric field sensor and minimizing the influence of ambient temperature on resonance. Thus, the driving voltage applied to the piezoelectric driving structure can be adjusted according to the reference current signal, improving the stability of the output sensitivity of the piezoelectric self-feedback excitation micro electric field sensor while maintaining the sensor in a continuous resonant state, achieving closed-loop resonator operation, improving the efficiency and accuracy of electric field detection, and maintaining the high output sensitivity and high resolution stability of the piezoelectric self-feedback excitation micro electric field sensor.

[0047] Furthermore, according to embodiments of this disclosure, the piezoelectric self-feedback excitation micro electric field sensor of this disclosure can be applied to electric field measurement environments in various fields, can accurately measure electric fields in various environments, is suitable for long-term stable measurement needs, and has a high degree of integration and application value.

[0048] According to embodiments of this disclosure, the materials used to prepare the substrate include at least one of the following: silicon, ceramics, glass, and other organic materials.

[0049] According to embodiments of this disclosure, in the substrate, the region corresponding to the mutually shielded electric field sensing structure and the vibration pickup reference structure is a hollow structure.

[0050] According to embodiments of this disclosure, the piezoelectric drive structure includes a drive electrode layer and a piezoelectric layer, and the resonator is composed of an electric field sensing movable electrode in a mutually shielded electric field sensing structure and a movable reference electrode in a vibration pickup reference structure.

[0051] According to embodiments of this disclosure, the resonator and the piezoelectric drive structure can be mechanically coupled through an elastic beam, and the electric field sensing movable electrode and the movable reference electrode can be connected through at least one of the elastic beam or capacitive coupling to form a sensor resonant structure.

[0052] According to an embodiment of this disclosure, the driving electrode layer includes a first sub-driving electrode layer and a second sub-driving electrode layer. The second sub-driving electrode layer is fixed to the elastic beam by an insulating layer and is used to drive the piezoelectric layer to deform in response to a received driving voltage.

[0053] According to embodiments of this disclosure, connecting the drive electrode layer and the elastic beam through an insulating layer can reduce the applied drive voltage, thereby reducing power consumption.

[0054] According to embodiments of this disclosure, the first sub-driving electrode layer can be a driving electrode layer on the side away from the substrate, and the second sub-driving electrode layer can be a driving electrode layer on the side closer to the substrate.

[0055] According to embodiments of this disclosure, the conductor material used to prepare the driving electrode layer may include at least one of the following: platinum, gold, silver, aluminum, and copper.

[0056] According to embodiments of this disclosure, the material used to prepare the insulating layer may include at least one of the following: silicon dioxide, silicon nitride; and the driving electrode layer is a conductor.

[0057] According to an embodiment of this disclosure, a piezoelectric layer is disposed between a first sub-driving electrode layer and a second sub-driving electrode layer, and is used to deform the piezoelectric material in the piezoelectric layer in response to the driving electrode layer, so that the elastic beam vibrates, thereby driving the resonator to vibrate.

[0058] According to an embodiment of this disclosure, a piezoelectric layer is disposed between the first sub-driving electrode layer and the second sub-driving electrode layer, an insulating layer is disposed below the second sub-driving electrode layer, and an elastic beam is disposed below the insulating layer.

[0059] According to embodiments of this disclosure, the piezoelectric layer can be deposited by sputtering or sol-gel method, and the material used to prepare the piezoelectric layer may include at least one of the following: aluminum nitride, zinc oxide, lead titanate, barium titanate, lead zirconate titanate, niobium-doped strontium titanate, and niobium-doped titanium dioxide having a high piezoelectric coefficient.

[0060] According to embodiments of this disclosure, the elastic beam can be a straight beam structure.

[0061] According to embodiments of this disclosure, a piezoelectric self-feedback excited micro electric field sensor includes at least one set of piezoelectric driving structures, that is, at least two piezoelectric driving structures, which are respectively located on both sides above the substrate.

[0062] According to embodiments of this disclosure, the electric drive structure includes a drive electrode layer and a piezoelectric layer. The drive electrode layer includes a first sub-drive electrode layer and a second sub-drive electrode layer. The second sub-drive electrode layer is fixed to the elastic beam through an insulating layer. The piezoelectric layer is disposed between the first sub-drive electrode layer and the second sub-drive electrode layer. When a periodic drive voltage is applied to the drive electrode layer, the piezoelectric layer deforms, causing the elastic beam to vibrate under pressure, thereby causing the resonator to vibrate. This allows the resonator to vibrate only by applying a drive voltage to the drive electrode layer, reducing the drive voltage and power consumption. By providing a piezoelectric drive structure at both ends of the elastic beam, the drive capability can be increased. Furthermore, by using a material with a high piezoelectric coefficient to prepare the piezoelectric layer, the coupling noise interference can be reduced while lowering the drive voltage, so that the electric field sensing movable electrode and the movable reference electrode can move in a vertical direction perpendicular to the substrate, thereby improving the electric field modulation capability.

[0063] According to embodiments of this disclosure, the mutually shielded electric field sensing structure may include a movable electric field sensing electrode and a fixed electric field sensing electrode.

[0064] According to embodiments of this disclosure, an electric field sensing movable electrode is suspended on a substrate by an elastic beam. In response to the vibration of the elastic beam, based on the principle of charge induction, the electric field sensing movable electrode generates vibration in the vertical direction relative to the substrate, so as to generate a relative change in position between the electric field sensing movable electrode and the electric field sensing fixed electrode, and output a differential form of induced current signal.

[0065] According to embodiments of this disclosure, when no driving voltage is applied to the driving electrode layer of the piezoelectric driving structure, the electric field sensing movable electrode and the electric field sensing fixed electrode are located on the same plane and can jointly constitute the sensitive structure of the piezoelectric self-feedback excitation micro electric field sensor, which can improve the output sensitivity of the piezoelectric self-feedback excitation micro electric field sensor.

[0066] According to an embodiment of the present disclosure, an electric field sensing fixed electrode is located above the substrate and is disposed opposite to an electric field sensing movable electrode. It is used to provide a reference position corresponding to the position of the electric field sensing movable electrode when the electric field sensing movable electrode vibrates, and together with the electric field sensing movable electrode, outputs a differential form of induced current signal.

[0067] According to an embodiment of this disclosure, an electric field sensing fixed electrode is suspended on a substrate by an elastic beam, comprising: one end of the electric field sensing fixed electrode is connected to the substrate and receives a supporting force provided by the substrate, so that the structure of the electric field sensing fixed electrode, except for the end connected to the substrate, is suspended, thereby allowing the electric field sensing movable electrode to vibrate in space.

[0068] According to embodiments of this disclosure, the electric field-sensing movable electrode and the electric field-sensing fixed electrode are disposed opposite to each other, and each of the electric field-sensing movable electrode and the electric field-sensing fixed electrode contains at least one set, that is, at least two electric field-sensing movable electrodes and two electric field-sensing fixed electrodes.

[0069] According to embodiments of this disclosure, both the electric field-sensing movable electrode and the electric field-sensing fixed electrode can be one of the following structures: a strip structure, a comb structure, or an irregular structure.

[0070] According to embodiments of this disclosure, under the action of a driving voltage, the piezoelectric material in the piezoelectric driving structure can deform, the elastic beam is forced to vibrate, and the resonator vibrates vertically up and down relative to the substrate. By changing the position of the electric field-sensing movable electrode, the relative positions between the electric field-sensing movable electrode and the electric field-sensing fixed electrode change. The positional change between the electric field-sensing movable electrode and the electric field-sensing fixed electrode changes the sensing effect of the electric field in the electric field space. That is, the electric field-sensing electrode closer to the electric field source senses more charge, thereby forming an electric field shielding effect on the other electric field-sensing electrode. During the up and down vibration of the resonator, the electric field-sensing movable electrode and the electric field-sensing fixed electrode shield each other. At the same time, differential output effectively improves the charge sensing efficiency of the electric field-sensing electrode while suppressing common-mode noise. Under the periodic driving voltage, the periodic vibration of the resonator causes the electric field-sensing movable electrode and the electric field-sensing fixed electrode to form a periodic induced current signal. The magnitude of the electric field to be measured can be obtained by measuring the magnitude of the current signal.

[0071] According to embodiments of this disclosure, the mutually shielded electric field sensing structure includes a movable electric field sensing electrode and a fixed electric field sensing electrode. The movable electric field sensing electrode is suspended on the substrate by an elastic beam. The fixed electric field sensing electrode is disposed opposite to the movable electric field sensing electrode. One end of the fixed electric field sensing electrode is connected to the substrate and receives a supporting force provided by the substrate, so that the structure of the fixed electric field sensing electrode, except for the end connected to the substrate, is suspended and integrated into the substrate. The area corresponding to the mutually shielded electric field sensing structure and the vibration pickup reference structure is a hollow structure, so that the movable electric field sensing electrode has a certain space to vibrate in the vertical direction relative to the substrate, thereby generating an electric field sensing electrode. Due to the relative change in position between the fixed electrodes, the induction effect of the electric field in the space between the movable and fixed electrodes changes. As the facing area of ​​the sides between the movable and fixed electrodes changes, they become mutually shielded, achieving mutually shielded differential induction, thereby improving charge induction efficiency. Based on the differential output signal, common-mode noise is suppressed. The fixed and movable electrodes jointly output a differential periodic induced current signal, so that the amplitude of the electric field to be measured can be obtained from the magnitude of the induced current signal.

[0072] According to embodiments of this disclosure, the vibration pickup reference structure may include a movable reference electrode and a fixed vibration pickup electrode.

[0073] According to embodiments of this disclosure, a movable reference electrode can be suspended on a substrate by an elastic beam and located on both sides of a mutually shielded electric field induction structure. In response to the vibration of the elastic beam, the movable reference electrode generates a vibration in the vertical direction relative to the substrate, thereby causing a relative change in position between the movable reference electrode and the vibration pickup fixed electrode, and changing the capacitance between the movable reference electrode and the vibration pickup fixed electrode.

[0074] According to embodiments of this disclosure, when no driving voltage is applied to the driving electrode layer of the piezoelectric driving structure, the movable reference electrode and the vibration pickup fixed electrode are located on the same plane and can jointly constitute the vibration pickup reference structure of the resonator of the piezoelectric self-feedback excitation type micro electric field sensor, so as to convert the mechanical vibration signal of the resonator into a measurable reference current signal, thereby adjusting the driving voltage according to the reference current signal in combination with the closed-loop feedback circuit to achieve resonant closed-loop self-excitation.

[0075] According to embodiments of this disclosure, a fixed electrode for picking up vibrations can be fixed above a substrate and disposed opposite to a movable reference electrode. It is used to provide a reference position corresponding to the position of the movable reference electrode when the movable reference electrode vibrates, and to output a reference current signal based on the capacitance change between the movable reference electrode and the fixed electrode for picking up vibrations.

[0076] According to an embodiment of the present disclosure, the vibration pickup and fixing electrode is located above the substrate, including: one end of the vibration pickup and fixing electrode is connected to the substrate and receives a supporting force provided by the substrate, so that the structure of the vibration pickup and fixing electrode other than the end connected to the substrate is suspended, thereby allowing the movable reference electrode to vibrate in space.

[0077] According to embodiments of this disclosure, the potential of the fixed pickup electrode can be clamped at a predetermined value so that the capacitance between it and the movable reference electrode changes, thereby outputting a reference current signal.

[0078] According to embodiments of this disclosure, the movable reference electrode and the vibration pickup fixed electrode are disposed opposite to each other, and each of the movable reference electrode and the vibration pickup fixed electrode contains at least one set, that is, at least two movable reference electrodes and two vibration pickup fixed electrodes.

[0079] According to embodiments of this disclosure, both the movable reference electrode and the vibration pickup fixed electrode can be one of the following structures: a strip structure, a comb structure, or an irregular structure.

[0080] According to embodiments of this disclosure, the vibration pickup reference structure includes a movable reference electrode and a fixed vibration pickup electrode. The movable reference electrode is suspended on a substrate by an elastic beam and is located on both sides of a mutually shielded electric field induction structure. The fixed vibration pickup electrode is fixedly disposed opposite to the movable reference electrode. One end of the fixed vibration pickup electrode is connected to the substrate and receives a supporting force provided by the substrate, so that the structure of the fixed vibration pickup electrode, except for the end connected to the substrate, is suspended. When the elastic beam vibrates, the fixed vibration pickup electrode can provide a reference position corresponding to the position of the movable reference electrode. The movable reference electrode vibrates in the vertical direction relative to the substrate, causing a relative change in position between the movable reference electrode and the fixed vibration pickup electrode, thereby changing the position of the movable reference electrode. The capacitance between the reference electrode and the fixed pickup electrode, and the clamping of the potential of the fixed pickup electrode, cause the output current of the fixed pickup electrode to change with the capacitance. When the movable reference electrode vibrates, the fixed pickup electrode outputs a reference current signal. Based on the relationship between the reference current signal and the resonant frequency and amplitude, the reference current signal is input to the closed-loop feedback circuit to achieve closed-loop self-excitation of the drive, improve the stability of the resonance, thereby improving the sensitivity and resolution stability of the piezoelectric self-feedback excitation micro electric field sensor, reducing the sensitivity drift of the piezoelectric self-feedback excitation micro electric field sensor, and reducing the influence of ambient temperature on the piezoelectric self-feedback excitation micro electric field sensor.

[0081] According to embodiments of this disclosure, when a periodic driving voltage is applied to the driving electrode layer, the amplitudes of the electric field-induced movable electrode and the movable reference electrode are consistent.

[0082] According to embodiments of this disclosure, the electric field sensor may include a piezoelectric self-feedback excitation micro electric field sensor with the structure described above.

[0083] According to embodiments of this disclosure, the electric field sensor also includes a two-dimensional or three-dimensional electric field sensor composed of multiple sensor-sensitive structures, which can be used to measure two-dimensional or three-dimensional electric fields or voltages.

[0084] Figure 1 A schematic diagram illustrating the structure of a piezoelectric self-feedback excitation micro electric field sensor according to an embodiment of the present disclosure is shown.

[0085] like Figure 1 As shown, Figure 1 The structure of a piezoelectric self-feedback excitation micro electric field sensor is shown. The sensor includes a substrate, an elastic beam, a piezoelectric driving structure, a mutually shielded electric field sensing structure, and a vibration pickup reference structure. The piezoelectric driving structure is fixed to both sides of the vibration pickup reference structure on the substrate via the elastic beam. The piezoelectric driving structure includes a driving electrode layer and a piezoelectric layer. The driving electrode layer is fixed to the elastic beam via an insulating layer. The mutually shielded electric field sensing structure includes a movable electric field sensing electrode and a fixed electric field sensing electrode. The vibration pickup reference structure includes a movable reference electrode and a fixed vibration pickup electrode. Figure 1As shown, the piezoelectric self-feedback excitation type micro electric field sensor includes a substrate 101, two elastic beams 102, two piezoelectric driving structures, a mutually shielded electric field sensing structure, and two vibration pickup reference structures. Both piezoelectric driving structures are located outside the substrate 101 and each includes a driving electrode layer 103. The driving electrode layer 103 includes a first sub-driving electrode layer 1031 and a second sub-driving electrode 1032. In the first piezoelectric driving structure, a piezoelectric layer 104 is disposed between the first sub-driving electrode layer 1031 and the second sub-driving electrode 1032, and the second sub-driving electrode 1032 is connected to the first elastic beam 102 via an insulating layer 105. Similarly, in the second piezoelectric driving structure, a piezoelectric layer 104 is also disposed between the first sub-driving electrode layer 1031 and the second driving electrode 1032, and the second sub-driving electrode 1032 is connected to the second elastic beam 102 via an insulating layer 105. The mutually shielded electric field sensing structure includes a movable electric field sensing electrode 106 and a fixed electric field sensing electrode 106. Electrode 107 is located directly above the hollow substrate 101. One end of the strip-shaped electric field induction movable electrode 106 is connected to the first elastic beam 102, and the other end of the strip-shaped electric field induction movable electrode 106 is connected to the second elastic beam 102. One end of the electric field induction fixed electrode 107 is connected to the substrate 101, and the other end of the electric field induction fixed electrode 107 is also connected to the substrate 101. The electric field induction movable electrode 106 and the electric field induction fixed electrode 107 are arranged opposite to each other. Two vibration pickup reference structures are located on both sides of the mutually shielded electric field induction structure. One end of the movable reference electrode 108 in the first vibration pickup reference structure is connected to the elastic beam 102, and one end of the vibration pickup fixed electrode 109 is connected to the substrate 101. One end of the movable reference electrode 108 in the second vibration pickup reference structure is connected to the elastic beam 102, and one end of the vibration pickup fixed electrode 109 is connected to the substrate 101. The movable reference electrode 108 and the vibration pickup fixed electrode 109 in the two vibration pickup reference structures are arranged opposite to each other.

[0086] Figure 2 A schematic diagram of the piezoelectric drive structure of a piezoelectric self-feedback excited micro electric field sensor according to an embodiment of the present disclosure is shown.

[0087] like Figure 2 As shown, Figure 2 A piezoelectric driving structure is shown. Located on a substrate, the piezoelectric driving structure includes a driving electrode layer and a piezoelectric layer. The driving electrode layer includes a first sub-driving electrode layer and a second sub-driving electrode layer. The piezoelectric driving structure is connected to an elastic beam via an insulating layer, and the elastic beam is connected to the substrate. Figure 2 As shown, Figure 2The piezoelectric drive structure includes a first sub-drive electrode layer 1031, a second sub-drive electrode 1032, and a piezoelectric layer 104. In addition to the piezoelectric drive structure, it also includes an insulating layer 105, an elastic beam 102, and a substrate 101. The piezoelectric layer 104 is located between the first sub-drive electrode layer 1031 and the second sub-drive electrode 1032 of the drive electrode layer 103. The second sub-drive electrode 1032 and the elastic beam 102 are connected through the insulating layer 105. The elastic beam 102 is connected to the substrate.

[0088] Figure 3 A schematic diagram illustrating the structure of a piezoelectric self-feedback excited micro electric field sensor according to another embodiment of the present disclosure is shown.

[0089] like Figure 3 As shown, Figure 3 This illustrates a piezoelectric self-feedback excitation miniature electric field sensor with a comb-tooth structure for the movable electrode used in electric field sensing. Figure 1 The layout and specific structure of the substrate, elastic beam, piezoelectric drive structure, and two vibration pickup reference structures in the strip-structured piezoelectric self-feedback excitation micro electric field sensor shown are the same. The only difference is that the comb-shaped movable electric field sensing electrode 301 and the fixed electric field sensing electrode 107 in the mutually shielded electric field sensing structure are located directly above the hollow substrate. One end of the comb-shaped movable electric field sensing electrode 301 is connected to the first elastic beam 102, and the other end is connected to the second elastic beam 102. One end of the fixed electric field sensing electrode 107 is connected to the substrate, and the other end is also connected to the substrate. The comb-shaped movable electric field sensing electrode 106 and the fixed electric field sensing electrode 107 are arranged opposite to each other.

[0090] According to embodiments of this disclosure, the electric field sensor may include a piezoelectric self-feedback excitation micro electric field sensor with the structure described above.

[0091] According to embodiments of this disclosure, the electric field sensor also includes a two-dimensional or three-dimensional electric field sensor composed of multiple sensor-sensitive structures, which can be used to measure two-dimensional or three-dimensional electric fields or voltages.

[0092] Figure 4 A flowchart illustrating an electric field detection method according to an embodiment of the present disclosure is shown schematically.

[0093] like Figure 4 As shown, the electric field detection method of this embodiment includes operations S410 to S480.

[0094] In operation S410, a piezoelectric self-feedback excitation micro electric field sensor is placed in the electric field to be measured.

[0095] In operation S420, a driving voltage is applied to the driving electrode layer of the piezoelectric self-feedback excitation micro electric field sensor to cause the elastic beam to vibrate.

[0096] According to embodiments of this disclosure, a driving voltage can be applied only to the driving electrode layer, which forces the piezoelectric layer to deform, thereby causing the piezoelectric driven structure to vibrate. Then, through the insulating layer connected to the elastic beam, the elastic beam can also be driven to vibrate periodically.

[0097] In operation S430, in response to the vibration of the elastic beam, a relative change in position occurs between the movable reference electrode and the vibration pickup fixed electrode based on the change in capacitance, and the vibration pickup fixed electrode outputs a reference current signal.

[0098] According to embodiments of this disclosure, the vibration of the elastic beam can drive the vibration of the resonator, thereby driving the vibration of the movable reference electrode, causing a relative change in the position between the movable reference electrode and the fixed vibration pickup electrode, resulting in a change in the capacitance between the movable reference electrode and the fixed vibration pickup electrode. At the same time, since the potential of the fixed vibration pickup electrode is clamped, the magnitude of the current output by the fixed vibration pickup electrode can change with the change in capacitance, thereby outputting a reference current signal.

[0099] In operation of S440, the reference current signal is input to the feedback circuit.

[0100] In operation of S450, the feedback circuit adjusts the magnitude of the drive voltage based on the reference current signal.

[0101] According to embodiments of this disclosure, the feedback circuit can obtain the resonant frequency and amplitude based on the reference current signal, thereby adjusting the magnitude of the driving voltage applied to the driving electrode layer to achieve closed-loop self-excitation of the drive, improving the stability of the resonance and the sensitivity stability of the sensor.

[0102] In operation S460, an adjusted driving voltage is applied to the driving electrode layer of the piezoelectric self-feedback excitation micro electric field sensor to obtain a piezoelectric self-feedback excitation micro electric field sensor with constant sensitivity.

[0103] In operation S470, in response to the vibration of the elastic beam of the piezoelectric self-feedback excitation micro electric field sensor with constant sensitivity, based on the principle of charge induction, the relative position change between the electric field induction movable electrode and the electric field induction fixed electrode is used to output a differential form of induced current signal.

[0104] According to embodiments of this disclosure, the vibration of the elastic beam can drive the vibration of the resonator, thereby driving the vibration of the electric field-sensing movable electrode, causing a relative change in position between the electric field-sensing movable electrode and the electric field-sensing fixed electrode. During the up-and-down vibration of the resonator, the electric field-sensing movable electrode and the electric field-sensing fixed electrode shield each other, and at the same time, differential output is obtained to obtain a differential form of periodic induced current signal, thereby improving the charge induction efficiency of the electrode while suppressing common-mode noise.

[0105] In operation S480, the amplitude intensity of the electric field to be measured is obtained based on the differential form of the induced current signal.

[0106] According to embodiments of this disclosure, the amplitude of the electric field to be measured can be obtained from the magnitude of the induced current signal.

[0107] According to embodiments of this disclosure, a piezoelectric self-feedback excitation micro electric field sensor is placed in the electric field to be measured. A driving voltage is applied to the driving electrode layer of the piezoelectric self-feedback excitation micro electric field sensor to cause the elastic beam to vibrate. The vibration of the elastic beam causes the resonator to vibrate simultaneously, thereby causing the reference movable electrode and the electric field sensing movable electrode to simultaneously generate periodic vibrations with a constant amplitude. The reference current signal output by the vibration pickup fixed electrode is then input into the feedback circuit so that the feedback circuit can adjust the magnitude of the driving voltage according to the reference current signal. This results in a piezoelectric self-feedback excitation micro electric field sensor with constant sensitivity. At the same time, the amplitude intensity of the electric field to be measured can be obtained from the differential form of the induced current signal output by the electric field sensing movable electrode and the electric field sensing fixed electrode.

[0108] According to embodiments of this disclosure, a piezoelectric self-feedback excitation micro electric field sensor is placed in the electric field to be measured. A driving voltage is applied to the driving electrode layer of the piezoelectric self-feedback excitation micro electric field sensor to cause an elastic beam to vibrate. In response to the vibration of the elastic beam, a relative positional change occurs between the movable reference electrode and the vibration-pickup fixed electrode based on the capacitance change. The vibration-pickup fixed electrode outputs a reference current signal, which is input to a feedback circuit. The feedback circuit can adjust the magnitude of the driving voltage according to the reference current signal, and apply the adjusted driving voltage to the driving electrode layer of the piezoelectric self-feedback excitation micro electric field sensor. By applying pressure, a piezoelectric self-feedback excitation micro electric field sensor with constant sensitivity is obtained. At this time, the elastic beam of the sensor vibrates. Based on the principle of charge induction, the relative position change between the electric field induction movable electrode and the electric field induction fixed electrode is generated, and a differential induced current signal is output. According to the differential induced current signal, the amplitude intensity of the electric field to be measured can be obtained, realizing the accurate detection of the amplitude of the electric field to be measured. Furthermore, due to the use of materials with high piezoelectric coefficients, the driving voltage can be reduced while reducing coupling noise interference, realizing the vertical movement of the movable electrode and improving the electric field modulation capability.

[0109] According to embodiments of this disclosure, by combining a feedback circuit to form a closed-loop self-excited drive, the stability of the resonance and the sensitivity stability of the sensor can be improved, the sensitivity drift of the miniature electric field sensor can be reduced, and the influence of ambient temperature on the sensor can be reduced. Furthermore, based on the vertical vibration between the electric field sensing fixed electrode and the electric field sensing movable electrode, mutually shielded differential induction can be achieved, effectively suppressing common-mode noise and improving charge induction efficiency.

[0110] Those skilled in the art will understand that the features described in the various embodiments of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments of this disclosure can be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0111] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of this disclosure. It should be understood that the above are only specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A piezoelectric self-feedback excitation type miniature electric field sensor, comprising: Substrate, used to support the vibration pickup reference structure, piezoelectric drive structure, mutually shielded electric field sensing structure and elastic beam; A piezoelectric driving structure is provided, comprising two sides of a vibration pickup reference structure fixed on a substrate by an elastic beam. The piezoelectric driving structure includes a driving electrode layer and a piezoelectric layer. The driving electrode layer includes a first sub-driving electrode layer and a second sub-driving electrode layer. The second sub-driving electrode layer is fixed on the elastic beam by an insulating layer. The piezoelectric layer is disposed between the first sub-driving electrode layer and the second driving electrode layer. The piezoelectric driving structure is used to apply a driving voltage to the first sub-driving electrode layer and the second driving electrode layer based on piezoelectric driving, driving the piezoelectric material in the piezoelectric layer to deform, so that the elastic beam vibrates in a direction perpendicular to the substrate. This drives a resonator composed of an electric field sensing movable electrode in the mutually shielded electric field sensing structure and a movable reference electrode in the vibration pickup reference structure through at least one of the elastic beam or capacitive coupling methods to vibrate, thereby reducing the driving voltage and power consumption and increasing the driving capability. The piezoelectric layer is deposited by sputtering or sol-gel method. A mutually shielded electric field sensing structure is disposed above the substrate to respond to the vertical vibration of the elastic beam. Based on the principle of charge induction, the mutually shielded electric field sensing structure outputs a differential periodic induced current signal to suppress common-mode noise and detect the amplitude intensity of the electric field under test based on the induced current signal with constant output sensitivity. A vibration pickup reference structure is disposed on both sides of the mutually shielded electric field induction structure and fixed above the substrate. One end of the vibration pickup fixed electrode is connected to the substrate and receives a supporting force provided by the substrate, so that the structure of the vibration pickup fixed electrode, except for the end connected to the substrate, is suspended. The vibration pickup reference structure includes at least two movable reference electrodes and at least two vibration pickup fixed electrodes. The movable reference electrodes are supported and suspended on the substrate by the elastic beam, and are used to generate vibration in the vertical direction relative to the substrate in response to the vibration of the elastic beam, so that the three sides of the movable reference electrodes are positioned relative to the substrate in the direction perpendicular to the substrate. The fixed electrode generates a change in its surface area, altering the capacitance between the movable reference electrode and the fixed electrode. The fixed electrode is fixed above the substrate and positioned opposite the movable reference electrode. It provides a reference position corresponding to the position of the movable reference electrode when the movable reference electrode vibrates. Based on the capacitance change, it converts the mechanical vibration signal of the resonator into a reference current signal and outputs it. This allows the magnitude of the driving voltage to be adjusted according to a predetermined relationship where the magnitude of the reference current signal is proportional to the product of the resonant frequency and the resonant amplitude, thereby maintaining the sensor's output sensitivity at a predetermined value. The vibration-picking fixed electrode and the electric field-sensing fixed electrode in the mutually shielded electric field-sensing structure both surround the sides of the comb-shaped structure of the movable reference electrode and the electric field-sensing movable electrode in the mutually shielded electric field-sensing structure. The vibration-picking fixed electrode is arranged adjacent to the electric field-sensing fixed electrode and the piezoelectric drive structure, and there is no movable reference electrode or electric field-sensing movable electrode therein.

2. The sensor according to claim 1, characterized in that, The mutually shielded electric field sensing structure includes: The electric field sensing movable electrode is suspended on the substrate by the elastic beam. In response to the vibration of the elastic beam, based on the charge induction principle, the electric field sensing movable electrode generates vibration in the vertical direction relative to the substrate, so as to generate a relative change in position between the electric field sensing movable electrode and the electric field sensing fixed electrode, and output the differential form of induced current signal. The electric field sensing fixed electrode is located above the substrate and is disposed opposite to the electric field sensing movable electrode. It is used to provide a reference position corresponding to the position of the electric field sensing movable electrode when the electric field sensing movable electrode vibrates, and together with the electric field sensing movable electrode, outputs the differential form of induced current signal.

3. The sensor according to claim 2, characterized in that, In the substrate, the region corresponding to the mutually shielded electric field sensing structure and the vibration pickup reference structure is a hollow structure; The electric field sensing fixed electrode is located above the substrate, and includes: one end of the electric field sensing fixed electrode is connected to the substrate and receives a supporting force provided by the substrate, so that the structure of the electric field sensing fixed electrode, except for the end connected to the substrate, is suspended.

4. The sensor according to claim 1, characterized in that, The materials used to prepare the insulating layer include at least one of the following: silicon dioxide and silicon nitride; the driving electrode layer is a conductor, and the conductor material used to prepare the driving electrode layer includes at least one of the following: platinum, gold, silver, aluminum, and copper; the materials used to prepare the piezoelectric layer include at least one of the following: aluminum nitride, zinc oxide, lead titanate, barium titanate, lead zirconate titanate, niobium-doped strontium titanate, and niobium-doped titanium dioxide, which have a high piezoelectric coefficient.

5. The sensor according to claim 1, characterized in that, The materials used to prepare the substrate include at least one of the following: silicon, ceramics, glass, and other organic materials.

6. A method for detecting electric field using a piezoelectric self-feedback excitation micro electric field sensor according to any one of claims 1 to 5, comprising: The piezoelectric self-feedback excitation micro electric field sensor is placed in the electric field to be measured; A driving voltage is applied to the driving electrode layer of the piezoelectric self-feedback excitation micro electric field sensor to cause the elastic beam to vibrate; In response to the vibration of the elastic beam, a relative change in position occurs between the movable reference electrode and the vibration-pickup fixed electrode based on the change in capacitance, and the vibration-pickup fixed electrode outputs the reference current signal. The reference current signal is input into the feedback circuit; Based on the reference current signal, the feedback circuit adjusts the magnitude of the driving voltage; An adjusted driving voltage is applied to the driving electrode layer of the piezoelectric self-feedback excitation micro electric field sensor to obtain the piezoelectric self-feedback excitation micro electric field sensor with constant sensitivity. In response to the vibration of the elastic beam of the piezoelectric self-feedback excitation micro electric field sensor with constant sensitivity, based on the principle of charge induction, the relative position change between the electric field induction movable electrode and the electric field induction fixed electrode is used to output a differential form of induced current signal. The amplitude intensity of the electric field to be measured is obtained from the differential form of the induced current signal.

7. An electric field sensor, comprising: The piezoelectric self-feedback excitation micro electric field sensor as described in any one of claims 1 to 5, or the piezoelectric self-feedback excitation micro electric field sensor obtained by the detection method described in claim 6.

8. The electric field sensor according to claim 7, characterized in that, The electric field sensor also includes a two-dimensional or three-dimensional electric field sensor composed of multiple sensor-sensitive structures, used to measure two-dimensional or three-dimensional electric fields or voltages.

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