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

Abstract

The invention provides a piezoelectric self-feedback excitation type miniature 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 miniature electric field sensor comprises a substrate used 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 enabling the piezoelectric driving structure to deform under the condition that driving voltage is applied to the piezoelectric driving structure so as to enable the elastic beam to generate vibration; the mutual shielding electric field induction structure is used for responding to the vibration of the elastic beam, and the mutual shielding electric field induction structure outputs an induction current signal in a differential form so as to suppress common-mode noise and detect the amplitude intensity of a to-be-detected electric field; and the vibration pickup reference structure is used for responding to the vibration of the elastic beam and outputting a reference current signal so as to adjust the magnitude of the driving voltage and enable the output sensitivity of the piezoelectric self-feedback excitation type miniature electric field sensor to be a preset value.

Description

Technical Field

[0001] The present disclosure relates to the technical field of electric field sensors, and more specifically to a piezoelectric self-feedback excitation micro electric field sensor, an electric field detection method and a sensor. Background Art

[0002] Electric field detection technology is widely used in aerospace, meteorology, electricity, hazardous chemicals, industrial production and other fields. Electric field sensors developed based on micro-electromechanical systems (MEMS) are used to detect electric fields because of their small size, light weight and low cost. Existing electric field sensors developed based on MEMS generally use electrostatic drive to modulate the electric field. However, the driving ability of electrostatic drive is weak and the interference to the measured electric field is large. As a result, the high requirements for existing electric field sensors cannot be met.

[0003] In the process of realizing the above-mentioned inventive concept, the inventors found that in the related technology, since the existing electric field sensors are affected by the driving mode, the output sensitivity and output resolution of the electric field sensors are less stable, and the detection stability of the electric field to be measured is less. Summary of the invention

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

[0005] According to the first aspect of the present 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 the substrate on both sides of the vibration pickup reference structure through elastic beams, and used for deforming the piezoelectric driving structure when a driving voltage is applied to the piezoelectric driving structure to cause the elastic beam to vibrate; a mutually shielded electric field sensing structure arranged above the substrate, and used for responding to the vibration of the elastic beam, the mutually shielded electric field sensing structure outputting an induced current signal in differential form, so as to suppress common mode noise and detect the amplitude strength of the electric field to be measured; a vibration pickup reference structure arranged on both sides of the mutually shielded electric field sensing structure, and used for responding to the vibration of the elastic beam, the vibration pickup reference structure outputting a reference current signal, 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.

[0006] According to an embodiment of the present disclosure, the mutually shielded electric field sensing structure includes an electric field sensing movable electrode and an electric field sensing fixed electrode; the electric field sensing movable electrode is suspended above a substrate by an elastic beam support, and is used to respond to the vibration of the elastic beam. Based on the charge induction principle, the electric field sensing movable electrode generates vibration in a vertical direction relative to the substrate, so that a relative change in position occurs between the electric field sensing movable electrode and the electric field sensing fixed electrode, and an induced current signal in a differential form is output; the electric field sensing fixed electrode is located above the substrate and is arranged opposite to the electric field sensing movable electrode, and 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 outputs an induced current signal in a differential form together with the electric field sensing movable electrode.

[0007] According to an embodiment of the present disclosure, a vibration pickup reference structure includes a movable reference electrode and a vibration pickup fixed electrode; the movable reference electrode is suspended above a substrate by an elastic beam support and is located on both sides of a mutually shielded electric field induction structure, and is used to respond to the vibration of the elastic beam, and the movable reference electrode generates vibrations in a vertical direction relative to the substrate, so as to cause a relative change in position between the movable reference electrode and the vibration pickup fixed electrode, thereby changing the capacitance between the movable reference electrode and the vibration pickup fixed electrode; the vibration pickup fixed electrode is fixed above the substrate and is arranged opposite to the movable reference electrode, and is used to provide a reference position corresponding to the position of the movable reference electrode when the movable reference electrode vibrates, and output a reference current signal according to the change in capacitance between the movable reference electrode and the vibration pickup fixed electrode.

[0008] According to an embodiment of the present disclosure, in the substrate, the area 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 other than 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 other than the end connected to the substrate is suspended.

[0009] According to an embodiment of the present disclosure, a piezoelectric driving structure includes a driving electrode layer and a piezoelectric layer, and a resonator is composed of an electric field-inducing movable electrode and a movable reference electrode; the driving electrode layer includes a first sub-driving electrode layer and a second sub-driving electrode layer, and the second sub-driving electrode layer is fixed on the elastic beam through an insulating layer, and the driving electrode layer is used to drive the piezoelectric layer to deform in response to a received driving voltage; the piezoelectric layer is arranged between the first sub-driving electrode layer and the 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.

[0010] According to an embodiment of the present 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, and 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, and niobium-doped titanium dioxide with a high piezoelectric coefficient.

[0011] According to an embodiment of the present disclosure, the material used to prepare the substrate includes at least one of the following: silicon, ceramic, glass, and other organic materials.

[0012] The second aspect of the present disclosure provides an electric field detection method, including: placing a piezoelectric self-feedback excitation micro electric field sensor in an electric field to be measured; applying a driving voltage to a driving electrode layer of the piezoelectric self-feedback excitation micro electric field sensor to vibrate an elastic beam; in response to the vibration of the elastic beam, a relative change in position is generated between a movable reference electrode and a vibration pickup fixed electrode based on a capacitance change, and the vibration pickup fixed electrode outputs a reference current signal; inputting the reference current signal into a feedback circuit; based on the reference current signal, the feedback circuit adjusts the voltage of the driving voltage; 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; 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 charge induction principle, using the relative change in position between the electric field induction movable electrode and the electric field induction fixed electrode, outputting an induced current signal in differential form; according to the induced current signal in differential form, obtaining the amplitude strength of the electric field to be measured.

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

[0014] According to an embodiment of the present disclosure, the electric field sensor also includes a two-dimensional or three-dimensional electric field sensor composed of a plurality of sensor sensitive structures, which is used to measure a two-dimensional or three-dimensional electric field or voltage.

[0015] According to the piezoelectric self-feedback excitation type micro electric field sensor, electric field detection method and sensor disclosed in the present invention, the 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 arranged above the substrate, and the piezoelectric driving structure is arranged on both sides of the substrate. 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 is deformed, thereby causing the elastic beam connected to the piezoelectric driving structure to vibrate. While reducing the driving voltage and reducing the coupling noise interference, the mutually shielded electric field sensing structure and the vibration pickup reference structure connected to the elastic beam are driven to vibrate perpendicular to the substrate direction, so as to improve the modulation capability of the electric field.

[0016] According to the embodiments of the present disclosure, further, based on the charge induction principle, the mutually shielded electric field induction structure outputs a differential induced current signal, so that the amplitude strength of the electric field to be measured can be detected according to the current size of the induced current signal, and the common mode noise caused by the influence of the external environment can be eliminated according to the differential induced current signal, so as to improve the charge induction efficiency, and the electric field to be measured can be accurately detected. Based on the capacitance change, the vibration pickup reference structure outputs a reference current signal, so that the reference current signal can be input into the feedback circuit, and the sensitivity drift of the piezoelectric self-feedback excitation type micro electric field sensor can be reduced, and the influence of the ambient temperature on the resonance can be reduced. Therefore, the driving voltage applied to the piezoelectric driving structure can be adjusted according to the reference current signal, and the stability of the output sensitivity of the piezoelectric self-feedback excitation type micro electric field sensor can be improved, while the working state of the piezoelectric self-feedback excitation type micro electric field sensor is kept in a resonant state, so as to realize the closed loop of the resonator, improve the efficiency and accuracy of the detection of the electric field to be measured, and maintain the high output sensitivity and high resolution stability of the piezoelectric self-feedback excitation type micro electric field sensor.

[0017] According to the embodiments of the present disclosure, further, the piezoelectric self-feedback excitation micro electric field sensor of the present disclosure can be applicable to the electric field measurement environment in various fields, can achieve accurate measurement of the electric field in a variety of environments, is suitable for long-term stable measurement requirements, and has a high degree of integration and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above contents and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

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

[0020] Figure 2 A schematic diagram schematically shows a piezoelectric driving structure of a piezoelectric self-feedback excitation type micro electric field sensor according to an embodiment of the present disclosure;

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

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

[0023] Reference numerals:

[0024] 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, electric field sensing movable electrode 106 with strip structure, electric field sensing fixed electrode 107, movable reference electrode 108, vibration pickup fixed electrode 109 and comb-tooth structure electric field sensing movable electrode 301. DETAILED DESCRIPTION

[0025] Hereinafter, embodiments of the present disclosure will 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 present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0026] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

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

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

[0029] In the technical solution of the present invention, the user information (including but not limited to user personal information, user image information, user device information, such as location information, etc.) 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, and the collection, storage, use, processing, transmission, provision, disclosure and application of the relevant data comply with relevant laws, regulations and standards, take necessary confidentiality measures, do not violate public order and good morals, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0030] Electric field detection technology is widely used in a variety of fields such as aerospace, meteorology, electricity, hazardous chemicals, and industrial production. Electric field sensors developed based on micro-electromechanical systems (MEMS) have the advantages of small size, light weight, and low cost, so they are used to detect electric fields. Existing electric field sensors developed based on micro-electromechanical systems generally use electrostatic drive to modulate the electric field. However, electrostatic drive has problems such as weak driving ability and small oscillation amplitude, while the new thermal drive method has low energy utilization, high temperature requirements, and poor applicability. As a result, the high requirements for existing electric field sensors cannot be met, resulting in low sensitivity of electric field sensors, and thus, it is impossible to obtain accurate electric field detection results.

[0031] Furthermore, researchers conducted a deeper research on the driving mode of electric field sensors in order to meet the current high demand for electric field sensors. During the research and development process, researchers found that in the related technology, the output sensitivity and output resolution of the electric field sensors were affected by the driving mode, resulting in low stability of the output sensitivity and output resolution of the electric field sensors, and low stability of the detection of the electric field to be measured.

[0032] In view of this, an embodiment of the present disclosure provides a piezoelectric self-feedback excitation type micro electric field sensor, comprising: a substrate, used to support 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 on both sides of the vibration pickup reference structure on the substrate through elastic beams, and used to deform the piezoelectric driving structure when a driving voltage is applied to the piezoelectric driving structure, so as to cause the elastic beam to vibrate; a mutually shielded electric field sensing structure, arranged above the substrate, and used to respond to the vibration of the elastic beam, and the mutually shielded electric field sensing structure outputs an induced current signal in a differential form, so as to suppress common mode noise and detect the amplitude strength of the electric field to be measured; a vibration pickup reference structure, arranged on both sides of the mutually shielded electric field sensing structure, and used to respond to the vibration of the elastic beam, and the vibration pickup reference structure outputs a reference current signal, 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.

[0033] The following will be passed Figure 1~Figure 3 The piezoelectric self-feedback excitation micro electric field sensor of the disclosed embodiment is described in detail.

[0034] According to an embodiment of the present 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 an embodiment of the present disclosure, the substrate may be used to support a vibration pickup reference structure, a piezoelectric driving structure, a mutually shielded electric field sensing structure, and an elastic beam.

[0036] According to an embodiment of the present disclosure, the piezoelectric driving structure can be fixed on both sides of the vibration pickup reference structure on the substrate through elastic beams, so that when a driving voltage is applied to the piezoelectric driving structure, the piezoelectric driving structure is deformed to cause the elastic beams to vibrate.

[0037] According to the embodiments of the present disclosure, a piezoelectric driving structure can be prepared by adopting a new material, thereby reducing the driving voltage and the coupling noise interference, so that the mutually shielded electric field sensing structure and the vibration pickup reference structure can move in the vertical direction relative to the substrate, thereby improving the electric field modulation capability. Furthermore, since the piezoelectric driving structure is driven to vibrate based on the piezoelectric driving method, the driving voltage applied to the piezoelectric driving structure can be reduced.

[0038] According to an embodiment of the present disclosure, a mutually shielded electric field sensing structure can be disposed above the substrate, and is used to output a differential induced 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.

[0039] According to an embodiment of the present 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 charge induction principle.

[0040] According to the embodiments of the present disclosure, when a driving voltage is applied to the piezoelectric driving structure, the piezoelectric driving structure drives the elastic beam to vibrate, and the mutually shielded electric field sensing structure outputs a differential induced current signal. The amplitude of the power plant to be tested can be obtained based on the size of the differential induced current signal. At the same time, common mode noise can be suppressed based on the differential induced current signal to improve the charge sensing efficiency.

[0041] According to an embodiment of the present disclosure, a vibration pickup reference structure can be arranged on both sides of the mutually shielded electric field sensing structure, and is used to respond to the vibration of the elastic beam, and the vibration pickup reference structure outputs a reference current signal to facilitate adjusting 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 an embodiment of the present disclosure, the vibration pickup reference structure is connected to the elastic beam, so that when the elastic beam vibrates, the vibration pickup reference structure vibrates, and a reference current signal is output according to the capacitance change.

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

[0044] According to an embodiment of the present disclosure, the predetermined relationship between the frequency and amplitude of the resonance and the reference current signal can be characterized as the magnitude of the reference current signal being proportional to the product of the frequency of the resonance and the amplitude of the resonance.

[0045] According to an embodiment of the present disclosure, a 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 arranged above the substrate, and the piezoelectric driving structure is arranged on both sides of the substrate. 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 is deformed, thereby causing the elastic beam connected to the piezoelectric driving structure to vibrate. While reducing the driving voltage and reducing the coupling noise interference, the mutually shielded electric field sensing structure and the vibration pickup reference structure connected to the elastic beam are driven to vibrate perpendicular to the direction of the substrate, so as to improve the modulation capability of the electric field.

[0046] According to the embodiments of the present disclosure, further, based on the charge induction principle, the mutually shielded electric field induction structure outputs a differential induced current signal, so that the amplitude strength of the electric field to be measured can be detected according to the current size of the induced current signal, and the common mode noise caused by the influence of the external environment can be eliminated according to the differential induced current signal, so as to improve the charge induction efficiency, and the electric field to be measured can be accurately detected. Based on the capacitance change, the vibration pickup reference structure outputs a reference current signal, so that the reference current signal can be input into the feedback circuit, and the sensitivity drift of the piezoelectric self-feedback excitation type micro electric field sensor can be reduced, and the influence of the ambient temperature on the resonance can be reduced. Therefore, the driving voltage applied to the piezoelectric driving structure can be adjusted according to the reference current signal, and the stability of the output sensitivity of the piezoelectric self-feedback excitation type micro electric field sensor can be improved, while the working state of the piezoelectric self-feedback excitation type micro electric field sensor is kept in a resonant state, so as to realize the closed loop of the resonator, improve the efficiency and accuracy of the detection of the electric field to be measured, and maintain the high output sensitivity and high resolution stability of the piezoelectric self-feedback excitation type micro electric field sensor.

[0047] According to the embodiments of the present disclosure, further, the piezoelectric self-feedback excitation micro electric field sensor of the present disclosure can be applicable to the electric field measurement environment in various fields, can achieve accurate measurement of the electric field in a variety of environments, is suitable for long-term stable measurement requirements, and has a high degree of integration and application value.

[0048] According to an embodiment of the present disclosure, the material used to prepare the substrate includes at least one of the following: silicon, ceramic, glass, and other organic materials.

[0049] According to an embodiment of the present disclosure, in the substrate, the area corresponding to the mutually shielding electric field induction structure and the vibration pickup reference structure is a hollow structure.

[0050] According to an embodiment of the present disclosure, the piezoelectric driving structure includes a driving electrode layer and a piezoelectric layer, and the resonator is composed of an electric field induction movable electrode in a mutually shielded electric field induction structure and a movable reference electrode in a vibration pickup reference structure.

[0051] According to an embodiment of the present disclosure, mechanical coupling can be achieved between the resonator and the piezoelectric driving structure 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 and capacitive coupling to form a sensor resonant structure.

[0052] According to an embodiment of the present 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 on the elastic beam through an insulating layer and is used to drive the piezoelectric layer to deform in response to a received driving voltage.

[0053] According to the embodiments of the present disclosure, the driving electrode layer and the elastic beam are connected through the insulating layer, so that the applied driving voltage can be reduced, thereby reducing power consumption.

[0054] According to an embodiment of the present disclosure, the first sub-driving electrode layer may be a driving electrode layer far away from a side of the substrate, and the second sub-driving electrode layer may be a driving electrode layer close to a side of the substrate.

[0055] According to an embodiment of the present 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 an embodiment of the present 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 the present disclosure, the piezoelectric layer is disposed between the first sub-driving electrode layer and the 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 as to vibrate the elastic beam and drive the resonator to vibrate.

[0058] According to an embodiment of the present 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 an embodiment of the present disclosure, the piezoelectric layer can be obtained by sputtering or sol-gel deposition, 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 with a high piezoelectric coefficient.

[0060] According to an embodiment of the present disclosure, the elastic beam may be a straight beam structure.

[0061] According to an embodiment of the present disclosure, the piezoelectric self-feedback excitation micro electric field sensor includes at least one group of piezoelectric driving structures, that is, at least two piezoelectric driving structures, and the two piezoelectric driving structures are respectively located on two sides above the substrate.

[0062] According to an embodiment of the present disclosure, the electric 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 through an insulating layer, and the piezoelectric layer is arranged between the first sub-driving electrode layer and the second sub-driving electrode layer. When a periodic driving voltage is applied to the driving electrode layer, the piezoelectric layer is deformed, driving the elastic beam to be forced to vibrate, thereby causing the resonator to vibrate, so that only the driving voltage is applied to the driving electrode layer to cause the resonator to vibrate, thereby reducing the driving voltage and reducing power consumption. By arranging a piezoelectric driving structure at both ends of the elastic beam, the driving capability can be increased. Furthermore, by using a material with a high piezoelectric coefficient to prepare the piezoelectric layer, the driving voltage can be reduced while reducing the coupling noise interference, 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 an embodiment of the present disclosure, the mutually shielding electric field inducing structure may include an electric field inducing movable electrode and an electric field inducing fixed electrode.

[0064] According to an embodiment of the present disclosure, the electric field sensing movable electrode is suspended above the substrate by an elastic beam support, and is used to respond to the vibration of the elastic beam. Based on the charge induction principle, the electric field sensing movable electrode generates vibration in a vertical direction relative to the substrate, so as to cause a relative change in position between the electric field sensing movable electrode and the electric field sensing fixed electrode, and output a differential induced current signal.

[0065] According to an embodiment of the present 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 in the same plane, which can together constitute the sensitive structure of the piezoelectric self-feedback excitation type micro electric field sensor, thereby improving the output sensitivity of the piezoelectric self-feedback excitation type micro electric field sensor.

[0066] According to an embodiment of the present disclosure, the electric field sensing fixed electrode is located above the substrate and is arranged 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 output a differential induced current signal together with the electric field sensing movable electrode.

[0067] According to an embodiment of the present disclosure, an electric field sensing fixed electrode is suspended above a substrate through elastic beam support, including: 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 the end connected to the substrate is suspended, so that the electric field sensing movable electrode can vibrate in space.

[0068] According to an embodiment of the present disclosure, the electric field sensing movable electrode and the electric field sensing fixed electrode are arranged opposite to each other, and each of the electric field sensing movable electrode and the electric field sensing fixed electrode includes at least one group, that is, at least two electric field sensing movable electrodes and two electric field sensing fixed electrodes.

[0069] According to an embodiment of the present disclosure, the electric field sensing movable electrode and the electric field sensing fixed electrode may both be one of the following structures: a strip structure, a comb-tooth structure, and an irregular structure.

[0070] According to the embodiments of the present disclosure, under the action of the driving voltage, the piezoelectric material in the piezoelectric driving structure can be deformed, and the elastic beam is forced to vibrate, driving the resonator to vibrate vertically up and down relative to the substrate. The position of the electric field sensing movable electrode changes, so that the position between the electric field sensing movable electrode and the electric field sensing fixed electrode changes relatively. The position change between the electric field sensing movable electrode and the electric field sensing fixed electrode changes the induction 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 charges, thereby forming an electric field shielding effect on the other electric field sensing electrode. In the process of the resonator vibrating up and down, the electric field sensing movable electrode and the electric field sensing fixed electrode shield each other and output differentially at the same time, effectively improving the charge induction 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 amplitude of the electric field to be measured can be obtained by measuring the magnitude of the current signal.

[0071] According to an embodiment of the present disclosure, the mutually shielded electric field sensing structure includes an electric field sensing movable electrode and an electric field sensing fixed electrode. The electric field sensing movable electrode is suspended on a substrate through elastic beam support. The electric field sensing fixed electrode is arranged opposite to the electric field sensing movable electrode. 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 other than the end connected to the substrate is suspended in the air, and is combined in 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 electric field sensing movable electrode has a certain space to vibrate in a vertical direction relative to the substrate, thereby generating vibrations with respect to the electric field sensing. Due to the relative change in the position between the fixed electrodes, the induction effect of the electric field sensing movable electrode and the electric field sensing fixed electrode on the spatial field to be measured changes. Since the side facing area between the electric field sensing movable electrode and the electric field sensing fixed electrode changes, the electric field sensing movable electrode and the electric field sensing fixed electrode are shielded from each other, and mutual shielding differential induction is achieved, thereby improving the charge induction efficiency and suppressing common mode noise according to the differential output signal. The electric field sensing fixed electrode and the electric field sensing movable electrode jointly output a differential periodic induced current signal, so as to obtain the amplitude of the electric field to be measured according to the current of the induced current signal.

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

[0073] According to an embodiment of the present disclosure, the movable reference electrode can be suspended above the substrate by means of an elastic beam support and located on both sides of the mutually shielded electric field induction structure, so that in response to the vibration of the elastic beam, the movable reference electrode generates vibration in a vertical direction relative to the substrate, so as to cause a relative change in position between the movable reference electrode and the vibration pickup fixed electrode, thereby changing the capacitance between the movable reference electrode and the vibration pickup fixed electrode.

[0074] According to an embodiment of the present 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 in the same plane, and can together constitute a 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, and then adjust 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 an embodiment of the present disclosure, the vibration pickup fixed electrode can be fixed above the substrate and arranged opposite to the movable reference electrode, so as to provide a reference position corresponding to the position of the movable reference electrode when the movable reference electrode vibrates, and output a reference current signal according to the change in capacitance between the movable reference electrode and the vibration pickup fixed electrode.

[0076] According to an embodiment of the present disclosure, the vibration pickup fixed electrode is located 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 in the air, thereby allowing the movable reference electrode to vibrate in space.

[0077] According to an embodiment of the present disclosure, the potential of the vibration pickup fixed electrode can be clamped at a predetermined value so that the capacitance between the fixed electrode and the movable reference electrode changes and a reference current signal is output.

[0078] According to an embodiment of the present disclosure, the movable reference electrode and the vibration pickup fixed electrode are arranged opposite to each other, and each of the movable reference electrode and the vibration pickup fixed electrode includes at least one group, that is, at least two movable reference electrodes and two vibration pickup fixed electrodes.

[0079] According to an embodiment of the present disclosure, the movable reference electrode and the vibration pickup fixed electrode may both be one of the following structures: a strip structure, a comb-tooth structure, and an irregular structure.

[0080] According to an embodiment of the present disclosure, a vibration pickup reference structure includes a movable reference electrode and a vibration pickup fixed 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 vibration pickup fixed electrode is fixedly arranged opposite to the movable reference electrode. 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. When the elastic beam vibrates, the vibration pickup fixed electrode can provide a reference position corresponding to the position of the movable reference electrode. The movable reference electrode generates vibration in a vertical direction relative to the substrate, so that a relative change in position occurs between the movable reference electrode and the vibration pickup fixed electrode, thereby changing the movable The capacitance between the reference electrode and the vibration pickup fixed electrode, and because the potential of the vibration pickup fixed electrode is clamped, the current output by the vibration pickup fixed electrode can change with the change of the capacitance. When the movable reference electrode vibrates, the vibration pickup fixed electrode outputs a reference current signal, so that according to the relationship between the reference current signal and the frequency and amplitude of the resonance, the reference current signal is input into the closed-loop feedback circuit to realize the 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 the embodiment of the present disclosure, when a periodic driving voltage is applied to the driving electrode layer, the amplitudes of the electric field sensing movable electrode and the movable reference electrode are consistent.

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

[0083] According to an embodiment of the present disclosure, the electric field sensor also includes a two-dimensional or three-dimensional electric field sensor composed of a plurality of sensor sensitive structures, which can be used to measure a two-dimensional or three-dimensional electric field or voltage.

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

[0085] like Figure 1 As shown, Figure 1 The structure of a piezoelectric self-feedback excitation type micro electric field sensor is shown. The piezoelectric self-feedback excitation type micro electric field 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 on both sides of the vibration pickup reference structure on the substrate through the elastic beam. The piezoelectric driving structure includes a driving electrode layer and a piezoelectric layer. The driving electrode layer is fixed on the elastic beam through an insulating layer. The mutually shielded electric field sensing structure includes an electric field sensing movable electrode and an electric field sensing fixed electrode. The vibration pickup reference structure includes a movable reference electrode and a vibration pickup fixed electrode. Figure 1As shown, the piezoelectric self-feedback excitation micro electric field sensor in the figure 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. The two piezoelectric driving structures are both located on the outside of the substrate 101 and respectively include 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. The piezoelectric layer 104 in the first piezoelectric driving structure is arranged 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 through the insulating layer 105. The piezoelectric layer 104 in the second piezoelectric driving structure is also arranged 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 second elastic beam 102 through the insulating layer 105. The electric field sensing movable electrode 106 and the electric field sensing fixed electrode 106 in the mutually shielded electric field sensing structure are connected to the second elastic beam 102. The electrode 107 is located directly above the hollow substrate 101, one end of the electric field sensing movable electrode 106 of the strip structure is connected to the first elastic beam 102, and the other end of the electric field sensing movable electrode 106 of the strip structure is connected to the second elastic beam 102, one end of the electric field sensing fixed electrode 107 is connected to the substrate 101, and the other end of the electric field sensing fixed electrode 107 is also connected to the substrate 101, the electric field sensing movable electrode 106 and the electric field sensing fixed electrode 107 are arranged opposite to each other, and the two vibration pickup reference structures are respectively located on both sides of the mutually shielded electric field sensing 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, and 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 a piezoelectric driving structure of a piezoelectric self-feedback excitation micro electric field sensor according to an embodiment of the present disclosure is schematically shown.

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

[0088] Figure 3 A schematic diagram schematically shows the structure of a piezoelectric self-feedback excitation micro electric field sensor according to another embodiment of the present disclosure.

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

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

[0091] According to an embodiment of the present disclosure, the electric field sensor also includes a two-dimensional or three-dimensional electric field sensor composed of a plurality of sensor sensitive structures, which can be used to measure a two-dimensional or three-dimensional electric field or voltage.

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

[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 an electric field to be measured.

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

[0096] According to the embodiments of the present disclosure, a driving voltage may be applied only to the driving electrode layer, and the piezoelectric layer may be forced to deform through the driving voltage, thereby driving the piezoelectric driving structure to vibrate. Then, through the insulating layer connected to the elastic beam, the elastic beam may 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 capacitance change, and the vibration pickup fixed electrode outputs a reference current signal.

[0098] According to the embodiments of the present disclosure, the vibration of the resonator can be driven by the vibration of the elastic beam, 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 current output by the fixed vibration pickup electrode can change with the change of capacitance, thereby outputting a reference current signal.

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

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

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

[0102] In operation S460, the adjusted driving voltage is applied to the driving electrode layer of the piezoelectric self-feedback excitation type micro electric field sensor to obtain the piezoelectric self-feedback excitation type 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 charge induction principle, the relative change in position between the electric field induction movable electrode and the electric field induction fixed electrode is utilized to output a differential induced current signal.

[0104] According to the embodiments of the present disclosure, the vibration of the resonator can be driven by the vibration of the elastic beam, 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 output differentially at the same time to obtain a periodic induced current signal in differential form, thereby achieving the goal of suppressing common mode noise while improving the charge induction efficiency of the electrode.

[0105] In operation S480, the amplitude strength of the electric field to be measured is obtained according to the differential induced current signal.

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

[0107] According to the embodiments of the present disclosure, a piezoelectric self-feedback excitation micro electric field sensor is placed in an electric field to be measured, and a driving voltage is applied to the driving electrode layer of the piezoelectric self-feedback excitation micro electric field sensor to make the elastic beam vibrate. The elastic beam vibrates and at the same time makes the resonator vibrate, so that the reference movable electrode and the electric field sensing movable electrode simultaneously generate periodic vibrations with a constant amplitude. The reference current signal output by the vibration-picking fixed electrode is then input into a feedback circuit so that the feedback circuit can adjust the voltage of the driving voltage according to the reference current signal. While obtaining a piezoelectric self-feedback excitation micro electric field sensor with constant sensitivity, the amplitude strength of the electric field to be measured can be obtained according to the differential induced current signal output by the electric field sensing movable electrode and the electric field sensing fixed electrode.

[0108] According to an embodiment of the present disclosure, a piezoelectric self-feedback excitation type micro electric field sensor is placed in an electric field to be measured, and a driving voltage is applied to a driving electrode layer of the piezoelectric self-feedback excitation type micro electric field sensor to make the elastic beam vibrate. In response to the vibration of the elastic beam, a relative change in position occurs between a movable reference electrode and a vibration pickup fixed electrode based on a capacitance change. The vibration pickup fixed electrode outputs a reference current signal, and the reference current signal is input into a feedback circuit. The feedback circuit can adjust the voltage of the driving voltage according to the reference current signal, and the adjusted driving voltage is applied to the driving electrode layer of the piezoelectric self-feedback excitation type micro electric field sensor. Pressure is applied to obtain a piezoelectric self-feedback excitation micro electric field sensor with constant sensitivity. At this time, the elastic beam of the sensor vibrates. Based on the charge induction principle, the relative change in position between the electric field induction movable electrode and the electric field induction fixed electrode is utilized to output a differential induced current signal. According to the differential induced current signal, the amplitude strength of the electric field to be measured can be obtained, thereby realizing accurate detection of the amplitude of the electric field to be measured. In addition, due to the use of materials with high piezoelectric coefficients, the coupling noise interference can be reduced while reducing the driving voltage, thereby realizing the vertical movement of the movable electrode and improving the electric field modulation capability.

[0109] According to the embodiments of the present disclosure, further, by combining the feedback circuit to form a closed-loop self-excitation of the drive, the stability of the resonance and the sensitivity stability of the sensor can be improved, the sensitivity drift of the micro electric field sensor can be reduced, and the influence of the ambient temperature on the sensor can be reduced. Furthermore, according to the up and down vibration between the electric field sensing fixed electrode and the electric field sensing movable electrode, mutual shielding differential sensing can be achieved, common mode noise can be effectively suppressed, and the charge sensing efficiency can be improved.

[0110] It will be appreciated by those skilled in the art that the features described in the various embodiments of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations and / or combinations are not explicitly described in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the features described in the various embodiments of the present disclosure may be combined and / or combined in a variety of ways. All of these combinations and / or combinations fall within the scope of the present disclosure.

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

Claims

1. A piezoelectric self-feedback excitation micro electric field sensor, comprising: A substrate, used for supporting a vibration pickup reference structure, a piezoelectric driving structure, a mutually shielded electric field sensing structure and an elastic beam; A piezoelectric drive structure, fixed on both sides of the vibration pickup reference structure on the substrate through the elastic beam, and configured to deform the piezoelectric drive structure when a driving voltage is applied to the piezoelectric drive structure, so as to cause the elastic beam to vibrate; A mutually shielded electric field sensing structure is disposed above the substrate and is used to respond to the vibration of the elastic beam, and the mutually shielded electric field sensing structure outputs a differential induced current signal to suppress common mode noise and detect the amplitude strength of the electric field to be measured; A vibration pickup reference structure is arranged on both sides of the mutually shielded electric field induction structure and is used to respond 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.

2. The sensor according to claim 1, characterized in that The mutually shielded electric field induction structure comprises an electric field induction movable electrode and an electric field induction fixed electrode; The electric field sensing movable electrode is suspended on the substrate through the elastic beam support, and is used for responding to the vibration of the elastic beam. Based on the charge induction principle, the electric field sensing movable electrode generates vibration in a vertical direction relative to the substrate, so that a relative position change occurs between the electric field sensing movable electrode and the electric field sensing fixed electrode, and the differential induced current signal is output; The electric field sensing fixed electrode is located above the substrate and is arranged 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 output the differential induced current signal together with the electric field sensing movable electrode.

3. The sensor according to claim 1, characterized in that The vibration pickup reference structure includes a movable reference electrode and a vibration pickup fixed electrode; The movable reference electrode is suspended on the substrate through the elastic beam support and is located on both sides of the mutually shielded electric field induction structure, and is used for responding to the vibration of the elastic beam, the movable reference electrode generates vibration in a vertical direction relative to the substrate, so as to generate a relative change in position between the movable reference electrode and the vibration pickup fixed electrode, thereby changing the capacitance between the movable reference electrode and the vibration pickup fixed electrode; The vibration pickup fixed electrode is fixed above the substrate and is arranged 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 output the reference current signal according to the change in capacitance between the movable reference electrode and the vibration pickup fixed electrode.

4. The sensor according to claim 2 or 3, characterized in that: In the substrate, the area 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, and includes: 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 other than the end connected to the substrate is suspended in the air; 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 the support force provided by the substrate so that the structure of the vibration pickup fixed electrode except the end connected to the substrate is suspended.

5. The sensor according to claim 1, characterized in that The piezoelectric driving structure includes a driving electrode layer and a piezoelectric layer, and the resonator is composed of the electric field sensing movable electrode and the movable reference electrode; The driving electrode layer comprises a first sub-driving electrode layer and a second sub-driving electrode layer, wherein the second sub-driving electrode layer is fixed on the elastic beam through an insulating layer, and the driving electrode layer is used to drive the piezoelectric layer to deform in response to a received driving voltage; The piezoelectric layer is disposed between the first sub-driving electrode layer and the 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 as to vibrate the elastic beam, thereby driving the resonator to vibrate.

6. The sensor according to claim 1, characterized in that 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, and niobium-doped titanium dioxide with a high piezoelectric coefficient.

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

8. An electric field detection method using the piezoelectric self-feedback excitation micro electric field sensor according to any one of claims 1 to 7, comprising: Placing the piezoelectric self-feedback excitation type micro electric field sensor in the electric field to be measured; Applying a driving voltage to the driving electrode layer of the piezoelectric self-feedback excitation type micro electric field sensor to vibrate the elastic beam; 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 capacitance change, and the vibration pickup fixed electrode outputs the reference current signal; Inputting the reference current signal into a feedback circuit; Based on the reference current signal, the feedback circuit adjusts the voltage of the driving voltage; Applying the adjusted driving voltage to the driving electrode layer of the piezoelectric self-feedback excitation type micro electric field sensor to obtain the piezoelectric self-feedback excitation type micro electric field sensor with constant sensitivity; In response to the vibration of the elastic beam of the piezoelectric self-feedback excitation type micro electric field sensor with constant sensitivity, based on the charge induction principle, the relative change in position between the electric field induction movable electrode and the electric field induction fixed electrode is utilized to output an induced current signal in a differential form; The amplitude strength of the electric field to be measured is obtained according to the differential induced current signal.

9. An electric field sensor, comprising: A piezoelectric self-feedback excitation type micro electric field sensor as described in any one of claims 1 to 7 or a piezoelectric self-feedback excitation type micro electric field sensor obtained by the preparation method as described in claim 7.

10. The electric field sensor according to claim 9, characterized in that: The electric field sensor also includes a two-dimensional or three-dimensional electric field sensor composed of a plurality of sensor sensitive structures, which is used to measure a two-dimensional or three-dimensional electric field or voltage.

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