Modal localization induced micro electric field sensor and detection method thereof

Abstract

The present disclosure provides a modal localization inductive micro electric field sensor and a detection method thereof. The sensor comprises a substrate, a resonator array arranged on the substrate through a support structure, an inductive structure arranged on both sides of the resonator array, the inductive structure comprising a movable structure and a fixed structure, the fixed structure being fixed on the substrate through the support structure, and the movable structure being supported by an elastic beam, a driving electrode arranged on one side of at least one resonator for driving the resonator array to drive the movable structure to vibrate, a perturbation electrode arranged on one side of the elastic beam for applying a voltage perturbation to make the resonator array generate a modal localization phenomenon, and a detection cover plate arranged above the resonator array and the inductive structure, one side of the detection cover plate close to the perturbation electrode being used for shielding the to-be-detected electric field above the inductive structure close to the perturbation electrode, and the other side of the detection cover plate being used for introducing the to-be-detected electric field above the inductive structure away from the perturbation electrode.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of sensors, and in particular to a modal localization inductive micro electric field sensor and a detection method thereof. BACKGROUND

[0002] Electric field detection has a wide range of applications in aerospace, meteorology, power, hazardous chemicals, industrial production and other fields. The resonant electric field sensor developed by micro-electro-mechanical system (MEMS) has the characteristics of small size, light weight and low cost, so it has become an important development direction in the field of electric field detection, and has been more and more applied and concerned in recent years. With the continuous expansion of the application of electric field sensors, the requirement for the sensitivity of the sensors is gradually improved. The sensor based on the principle of modal localization has important potential in improving the sensitivity. However, the research on micro electric field sensor is still in the initial stage, and the key performance parameters such as sensitivity and resolution of the sensor still have a lot of room for improvement, and the non-linear problem of electric field and modal localization output still needs to be further solved to reduce the error. SUMMARY

[0003] In view of the above problems, the present application provides a modal localization inductive micro electric field sensor and a detection method thereof to solve the above technical problems.

[0004] A first aspect of the present disclosure provides a modal localization inductive micro electric field sensor, comprising: a substrate, a resonator array, an inductive structure, a driving electrode, an elastic beam, a perturbation electrode and a detection cover plate; the resonator array is arranged on the substrate through a support structure; the inductive structure is arranged on both sides of the resonator array, and the inductive structure comprises a plurality of movable structures and a plurality of fixed structures, wherein the fixed structure and the movable structure are both parallel to the surface of the substrate, the fixed structure is fixed on the substrate through a support structure, and the movable structure is supported by the elastic beam; the driving electrode is arranged on one side of at least one resonator in the resonator array, for driving the resonator array to drive the movable structures on both sides to vibrate, so as to generate corresponding induced current on the fixed structure; the elastic beam is arranged on one side of the inductive structure and is in the same plane as the inductive structure; the perturbation electrode is arranged on one side of the elastic beam, for applying voltage perturbation to make the resonator array generate modal localization phenomenon; the detection cover plate is arranged above the resonator array and the inductive structure, and the side close to the perturbation electrode is used for shielding the to-be-measured electric field above the inductive structure close to the perturbation electrode, and the other side is used for introducing the to-be-measured electric field above the inductive structure away from the perturbation electrode.

[0005] Optionally, the resonator array is capacitively or mechanically coupled between adjacent resonators.

[0006] Optionally, the movable structures and the fixed structures correspond to each other one by one, and are strip structures, comb structures or irregular shape structures, and are staggered in a direction perpendicular to an arrangement direction of the resonator array.

[0007] Optionally, each group of corresponding movable structures and fixed structures are provided with combs on opposite sides, and the combs on the movable structures and the fixed structures are staggered with each other.

[0008] Optionally, one end of the driving electrode is fixed to the substrate through a support structure, and the other end is a comb structure, the comb structure of the driving electrode is staggered with the comb electrode on the corresponding resonator, and the resonator corresponding to the driving electrode is one pair of symmetrical resonators in the resonator array.

[0009] Optionally, the detection cover plate at least includes: a conductive cover plate, a conductive cover plate extension layer, an insulating layer and a conductive shielding layer; the conductive cover plate extension layer and the insulating layer are located on the bottom surface of the conductive cover plate, the insulating layer is located above the sensing structure close to the perturbation electrode, and the metal cover plate extension layer is located above the sensing structure away from the perturbation electrode; the conductive shielding layer is arranged below the insulating layer and is fixed to the substrate by bonding or bonding.

[0010] Optionally, the conductive cover plate, the conductive cover plate extension layer and the conductive shielding layer are metal conductive materials or composite conductor materials.

[0011] The second aspect of the present disclosure provides a detection method of a modal-localized inductive micro electric field sensor, applied to the modal-localized inductive micro electric field sensor of the first aspect, and characterized in that the method comprises: applying a driving voltage to a driving electrode of the modal-localized inductive micro electric field sensor, and applying a perturbation voltage to a perturbation electrode of the modal-localized inductive micro electric field sensor; applying a to-be-detected electric field to the modal-localized inductive micro electric field sensor, collecting currents output by two-side sensing structures in the modal-localized inductive micro electric field sensor; calculating a ratio of the currents output by the two-side sensing structures, and converting a strength value of the to-be-detected electric field based on a mapping relationship between the ratio and a strength of the to-be-detected electric field.

[0012] The above at least one technical solution adopted in the embodiments of the present disclosure can achieve the following beneficial effects:

[0013] The embodiment of the present disclosure provides a modal localization-based inductive micro electric field sensor, which combines the modal localization amplification effect with high-sensitivity charge induction, and the electric field detection output signal is in the form of the induced current ratio generated by the sensing structure part at both ends of the resonator; the sensor is based on the detection principle, uses the form of a multilayer detection cover plate to shield one end of the electric field, places the electric field detection area on both sides of the sensitive structure (the resonator array and the sensing structure), increases the distance between the two end sensing areas, and prevents the influence of the intersection part between the electric field shielding area and the electric field exposed area on the electric field detection; the sensor fully utilizes the large amplitude ratio generated by the modal localization phenomenon in the weakly coupled resonant system, avoids the nonlinear relationship between the modal localization sensor output and the measured value, thereby reducing the influence of the nonlinear error on the electric field detection, and can greatly improve the sensitivity and resolution of the electric field measurement. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order for the present disclosure and its advantages to be more completely understood, a description will now be made with reference to the following description, taken in conjunction with the accompanying drawings, in which:

[0015] Figure 1 An illustrative schematic diagram of a modal localization inductive micro electric field sensor provided by the embodiment of the present disclosure is shown schematically;

[0016] Figure 2 An illustrative schematic diagram of a sensitive structure of a modal localization inductive micro electric field sensor provided by the embodiment of the present disclosure is shown schematically;

[0017] Figure 3A An illustrative schematic diagram of a sensing structure provided by the embodiment of the present disclosure is shown schematically;

[0018] Figure 3B An illustrative schematic diagram of a sensing structure provided by the embodiment of the present disclosure is shown schematically;

[0019] Figure 4 An illustrative cross-sectional view of a detection cover plate structure provided by the embodiment of the present disclosure is shown schematically;

[0020] Figure 5 An illustrative flowchart of a detection method of a modal localization inductive micro electric field sensor provided by the embodiment of the present disclosure is shown schematically.

[0021] REFERENCE NUMERALS

[0022] 1-substrate, 2-resonator array, 3-sensing structure, 31-movable structure, 32-fixed structure, 4-driving electrode, 5-detection cover plate, 51-conductive cover plate, 52-conductive cover plate extension layer, 53-insulating layer, 54-conductive shielding layer, 55-conductive gel, 6-metallic boss, 7-disturbance electrode, 8-elastic beam. DETAILED DESCRIPTION

[0023] Embodiments of the present disclosure will be described below with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. However, it will be apparent to one skilled in the art that the embodiments can be practiced without these specific details. In addition, in the following description, descriptions of well-known structures and techniques have been omitted to avoid unnecessarily obscuring the concept of the present disclosure.

[0024] The terms used herein are merely used to describe specific embodiments and are not intended to limit the present disclosure. The terms "include", "comprise" and the like used herein indicate the presence of the described features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0025] All terms used herein, including technical and scientific terms, have meanings commonly understood by one of ordinary skill in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having meanings consistent with the context of the specification, and should not be interpreted in an idealized or overly formal manner.

[0026] As shown in Figure 1 The modal localization inductive micro electric field sensor provided by the embodiments of the present disclosure includes a substrate 1, a resonator array 2, an inductive structure 3, a driving electrode 4, a perturbation electrode 7, a detection cover plate 5 and an elastic beam 8. The resonator array 2 and the inductive structure 3 are located in the same plane, and the resonator array 2 is arranged on the substrate 1 through a support structure; the inductive structure 3 is arranged on both sides of the resonator array 2, and the inductive structure 3 includes a plurality of movable structures 32 and a plurality of fixed structures 31, wherein the fixed structures 31 and the movable structures 32 are both parallel to the surface of the substrate 1, the fixed structures 31 are fixed on the substrate 1 through a support structure, and the movable structures 32 are supported by the elastic beam 8; the driving electrode 4 is arranged on one side of at least one resonator in the resonator array 2, for driving the resonator array 2 to drive the movable structures 32 on both sides to vibrate, so that corresponding inductive current is generated on the fixed structures 31; the elastic beam 8 is arranged on the side of each inductive structure 3 away from the resonator array 2, and is in the same plane as the inductive structure 3; the perturbation electrode 7 is arranged on the side of the elastic beam 8 close to the inductive structure 3, for applying voltage perturbation to make the resonator array 2 generate modal localization phenomenon; the detection cover plate 5 is arranged above the resonator array 2 and the inductive structure 3, and the side close to the perturbation electrode 7 is used to shield the to-be-measured electric field above the inductive structure 3 close to the perturbation electrode 7, and the other side is used to introduce the to-be-measured electric field above the inductive structure 3 away from the perturbation electrode 7.

[0027] The working principle of the modal localization inductive micro electric field sensor provided by the embodiments of the present disclosure is as follows: under the action of a driving voltage, the driving electrode 4 drives the resonator to vibrate, vibration energy is transmitted to the entire resonator array 2 through the coupling effect between the resonators, and the entire resonator system reaches a balanced state; a perturbation voltage is applied to the perturbation electrode 7, so that the resonator array 2 generates a modal localization phenomenon; a to-be-measured electric field is introduced above the sensing structure 3 away from the perturbation electrode 7, wherein, due to the shielding effect of the detection cover plate 5, the influence of the to-be-measured electric field on the sensing structure 3 close to the perturbation electrode 7 can be ignored, and the electric field above the sensing structure 3 close to the perturbation electrode 7 is the electric field generated by the perturbation voltage; the movable structure 32 in the sensing structure 3 horizontally vibrates under the drive of the resonator, and a corresponding induced current is generated on the fixed structure 31. According to the charge induction principle, the current output of the two sensing structures 3 is related to the electric field intensity above the movable structure 32 and the vibration amplitude of the movable structure 32. Since the perturbation voltage is constant, the vibration amplitude ratio of the movable structure 32 of the two sensing structures 3 and the electric field intensity above the fixed structure 31 remain unchanged, and the induced current ratio output by the two sensing structures 3 is linearly related to the to-be-measured electric field intensity. Therefore, the size of the measured electric field can be measured by detecting the ratio of the induced currents of the two sensing structures of the modal localization inductive micro electric field sensor provided by the embodiments of the present disclosure.

[0028] As shown in Figure 2 , the sensitive structure of the modal localization inductive micro electric field sensor provided by the embodiments of the present disclosure includes the resonator array 2, the sensing structure 3, the driving electrode 4 and the elastic beam 8.

[0029] Referring to Figure 2 , the resonator array 2 includes three resonators, each resonator includes two groups of support beams and a mass block, wherein the resonator structures on the left and right sides are the same, and the middle part of the middle resonator is provided with a rectangular mass block. The adjacent resonators in the resonator array 2 are capacitively coupled, and can vibrate in a direction parallel to the substrate 1 under the action of the driving electrode 4. Alternatively, each resonator can only include two groups of support beams, and the mass of each support beam can be equivalent to a mass block.

[0030] One end of the driving electrode 4 is fixed to the substrate 1 through a support structure, and the other end is a comb structure. As shown in Figure 2 , the comb structure of each driving electrode is staggered with the comb electrode on the corresponding resonator, the corresponding resonator is a pair of symmetrical resonators in the resonator array 2, and the driving electrode is arranged on both sides of each resonator. Referring to Figure 2The driving electrode 4 is close to two resonators on the two ends of the resonator array 2, is coplanar with the resonators that are not vibrated, is fixed on the substrate 1 by the support structure at one end, is etched into a comb shape at the other end, and is opposite to the comb electrode on the resonator, and is used for driving the two resonators on the two ends of the resonator array 2 to vibrate horizontally. The driving mode of the driving electrode 4 and the number and shape design of the electrode pairs are set according to specific conditions, and the embodiment does not limit this.

[0031] Reference Figure 2 The induction structure 3 is arranged on the two sides of the resonator array 2. Reference Figure 3A and Figure 3B The induction structure 3 includes a plurality of movable structures 32 and a plurality of fixed structures 31. The movable structures 32 and the fixed structures 31 correspond to each other, and are all strip structures and are arranged in a staggered manner perpendicular to the arrangement direction of the resonator array 2 (that is, the transverse central axis of the resonator array 2). The induction structure 3 is provided with an elastic beam 8 away from the resonator array 2. The movable structures 32 in the induction structure 3 are connected to the support structure through the elastic beam 8; and the fixed structures 31 are fixed on the substrate 1 through the support structure.

[0032] As shown in Figure 3A and Figure 3B , in the embodiment, 16 pairs of fixed structures 31 are arranged. The induction structures 3 on the two sides of the resonator array 2 are completely the same. When the shielding structure 32 is vibrated parallel to the plane of the substrate 1 under the driving of the resonator array 2, an induced current will be generated on the fixed structure 31 under the action of the electric field. As shown in Figure 3B , the side opposite to the corresponding fixed structure 31 of each movable structure 32 can be provided with a comb tooth, and the comb teeth of the movable structure 32 and the fixed structure 31 are staggered with each other. The induction structure 3 can also adopt a vertical vibration mode, and the specific implementation mode of the charge induction is not limited in the embodiment. Alternatively, the movable structure 32 and the fixed structure 31 can also be irregular shape structures, for example, curved shape, broken line shape, etc.

[0033] Reference Figure 4The detection cover plate 5 comprises at least a conductive cover plate 51, a conductive cover plate extension layer 52, an insulating layer 53 and a conductive shielding layer 54. The conductive cover plate extension layer 52 and the insulating layer 53 are both located on the bottom surface of the conductive cover plate 51. The insulating layer 53 is located above the sensing structure 3 close to the perturbation electrode 7, and the conductive cover plate extension layer 52 is located above the sensing structure 3 away from the perturbation electrode 7. The conductive shielding layer 54 is arranged below the insulating layer 53 and is fixed to the substrate 1 by bonding or bonding. Specifically, the conductive shielding layer 54 can be connected to the metal boss 6 arranged on the substrate 1 through the conductive gel 55, so that the conductive shielding layer 54 is fixed to the substrate 1. The conductive cover plate 51 and the conductive cover plate extension layer 52 below it can guide the electric field to be measured into the gap between the resonators below the conductive cover plate extension layer 52. The insulating layer 53 is used to hinder the conduction of electric charges between the resonators on the other side. The conductive shielding layer 54 is used to conduct the electric charges to the ground, thereby shielding the electric field above the sensing structure 3 on this side.

[0034] In the modal localization sensing type micro electric field sensor provided in the embodiments of the present disclosure, the resonators are driven to work at the required resonance frequency through the designed driving structure, and a constant perturbation voltage is applied to one end of the resonator array 2, so that a stable stiffness perturbation can be generated on the weakly coupled resonator array 2. The sensing structures 3 on both sides of the resonator array 2 vibrate with the resonator array 2. Based on the principle of modal localization, the amplitude ratio of the sensing structures 3 on both sides is only related to the size of the external perturbation. When the perturbation size does not change, the amplitude ratio of the sensing structures 3 below the insulating layer 53 to the sensing structures 3 below the insulating layer 53 remains unchanged, and therefore the current ratio of the sensing currents output by the sensing structures 3 on both sides only reflects the change of the electric field to be measured and is in a linear relationship with the electric field to be measured.

[0035] In the modal localization sensing type micro electric field sensor provided in the embodiments of the present disclosure, the detection cover plate 5 comprises a multi-layer structure, the electric field detection area is arranged on both sides of the sensitive structure, the distance between the two sensing areas is increased, the influence of the intersection part of the electric field shielding area and the electric field exposed area on the electric field detection is prevented, and a larger acceptable range of alignment error is provided when the cover plate is connected to the sensitive structure in actual operation. Based on the principle of modal localization, the electric field sensor adopts a charge sensing detection output mode, avoids the nonlinear relationship between the electric field to be measured and the output, eliminates the influence of nonlinear errors on electric field measurement, has the characteristics of high sensitivity, large charge sensing area and high integration, and is conducive to the wide application of the electric field sensor in meteorological detection, aerospace, industrial production, smart grid, national defense and military, and scientific research.

[0036] In this embodiment, the conductive cover plate 51, the conductive cover plate extension layer 52, and the conductive shielding layer 54 can be made of metal conductive materials such as metal or silicon wafers, or composite conductor materials. The conductive shielding layer 54 and the metal boss 6 can be made of gold or aluminum, and the insulating layer 53 can be made of polytetrafluoroethylene or silicon dioxide. The materials used for each layer and the cover plate structure are determined according to specific circumstances and are not limited here.

[0037] In addition to the aforementioned modal localization inductive micro electric field sensor, this disclosure also provides a detection method for the modal localization inductive micro electric field sensor.

[0038] like Figure 5 As shown in the embodiments of this disclosure, a detection method for a modal localization inductive micro electric field sensor includes S501 to S503.

[0039] S501, a driving voltage is applied to the driving electrode 4 of the modal localization inductive micro electric field sensor, and a perturbation voltage is applied to the perturbation electrode 7 of the modal localization inductive micro electric field sensor.

[0040] S502, apply the electric field to be measured to the modal localization inductive micro electric field sensor, and collect the current output by the sensing structures 3 on both sides of the modal localization inductive micro electric field sensor.

[0041] S503, calculate the ratio of the currents output by the two induction structures 3, and based on the mapping relationship between the ratio and the electric field strength to be measured, calculate the strength value of the electric field to be measured.

[0042] In this embodiment, the driving structure drives the resonator to vibrate under the action of the driving voltage, and the energy is conducted to the entire resonator array 2 through the coupling structure, causing the sensing structures 3 on both sides of the sensor to vibrate and generate induced current. A perturbation voltage is applied to the perturbation electrode 7, causing the resonator array 2 to produce a mode localization phenomenon. Due to the shielding effect of the detection cover plate 5, the influence of the electric field to be measured on the sensing structure 3 on the side closer to the perturbation electrode 7 can be ignored. According to the principle of charge induction, the current output of the sensing structures 3 on both sides is related to the electric field strength above them and the vibration amplitude of the movable structure 32. Since the perturbation voltage is constant, the ratio of the vibration amplitude of the movable structure 32 on both sides of the sensing structures 3 and the electric field strength above the fixed structure 31 remain unchanged, and the ratio of the induced current output by the sensing structures 3 on both sides is linearly related to the electric field strength to be measured. Therefore, the magnitude of the electric field to be measured can be measured by detecting the ratio of the induced currents on both sides of the mode localization inductive miniature electric field sensor provided in this embodiment.

[0043] Those skilled in the art can understand that the features recited in various embodiments of the present disclosure and / or claims can be combined or / and integrated, even if such combination or integration is not explicitly recited in the present disclosure. In particular, the features recited in various embodiments of the present disclosure and / or claims can be combined and / or integrated in various combinations, without departing from the spirit and teachings of the present disclosure. All such combinations and / or integrations fall within the scope of the present disclosure.

[0044] While the present disclosure has been shown and described with reference to certain exemplary embodiments thereof, it is to be understood that the present disclosure is not limited to the above- described embodiments, but instead is applicable to any modifications or permutations thereof falling within the scope of the appended claims and their equivalents. Accordingly, the scope of the present disclosure should be determined not by the embodiments disclosed above, but by the appended claims and their equivalents.

Claims

1. A modal localized inductive micro-electric field sensor, characterized in that, The application relates to a resonator array device, which comprises a substrate (1), a resonator array (2), an induction structure (3), a driving electrode (4), an elastic beam (8), a perturbation electrode (7) and a detection cover plate (5). The resonator array (2) is arranged on the substrate through a support structure; The induction structure (3) is arranged on both sides of the resonator array (2), and the induction structure (3) comprises a plurality of movable structures (32) and a plurality of fixed structures (31), wherein the fixed structures (31) and the movable structures (32) are both parallel to the surface of the substrate (1), the fixed structures (31) are fixed on the substrate (1) through a support structure, and the movable structures (32) are supported through the elastic beam (8). The driving electrode (4) is arranged on one side of at least one resonator in the resonator array (2) and is used for driving the resonator array (2) to drive the movable structures (32) on both sides to vibrate, so that corresponding induction currents are generated on the fixed structures (31). The elastic beam (8) is arranged on one side of each induction structure (3) and is in the same plane as the induction structure (3). The perturbation electrode (7) is arranged on one side of the elastic beam (8) and is used for applying a voltage perturbation to make the resonator array (2) generate a mode localization phenomenon. The detection cover plate (5) is arranged above the resonator array (2) and the induction structure (3), and one side close to the perturbation electrode (7) is used for shielding the to-be-measured electric field above the induction structure (3) close to the perturbation electrode (7), and the other side is used for introducing the to-be-measured electric field above the induction structure (3) far away from the perturbation electrode (7). The detection cover plate (5) at least comprises a conductive cover plate (51), a conductive cover plate extension layer (52), an insulating layer (53) and a conductive shielding layer (54). The conductive cover plate extension layer (52) and the insulating layer (53) are both located on the bottom surface of the conductive cover plate (51), the insulating layer (53) is located above the induction structure (3) close to the perturbation electrode (7), and the conductive cover plate extension layer (52) is located above the induction structure (3) far away from the perturbation electrode (7). The conductive shielding layer (54) is arranged below the insulating layer (53) and is fixed on the substrate (1) through bonding or bonding. The resonator array (2) is electrically coupled or mechanically coupled between adjacent resonators. The movable structures (32) and the fixed structures (31) correspond to each other, and are all strip structures, comb structures or irregular shape structures and are arranged in a staggered mode perpendicular to the arrangement direction of the resonator array (2).

2. The modal localized inductive micro-electrical field sensor according to claim 1, characterized in that, Each corresponding movable structure (32) and fixed structure (31) is provided with a comb tooth on the opposite side, and the comb teeth on the movable structure (32) and the fixed structure (31) are staggered.

3. The modal localized inductive micro-electrical field sensor according to claim 1, wherein, ​ 4. The modal localized inductive micro-electrical field sensor according to claim 3, characterized in that, ​ 5. The modal localized inductive micro-electrical field sensor according to claim 1, wherein, One end of the drive electrode (4) is fixed on the substrate (1) through a support structure, and the other end is a comb structure; the comb structure of the drive electrode (4) is staggered with the comb electrode on the corresponding resonator, and the resonator corresponding to the drive electrode (4) is a pair of symmetrical resonators in the resonator array (2).

6. The modal localized inductive micro-electrical field sensor of claim 1, wherein, The conductive cover plate (51), the conductive cover plate extension layer (52) and the conductive shielding layer (54) are metal conductive materials or composite conductor materials.

7. A detection method of a modal-localized inductive micro-electric field sensor, applied to the modal-localized inductive micro-electric field sensor according to any one of claims 1 to 6, characterized in that, Comprise: A driving voltage is applied to the drive electrode (4) of the modal localization inductive micro electric field sensor, and a disturbance voltage is applied to the disturbance electrode (7) of the modal localization inductive micro electric field sensor; A to-be-measured electric field is applied to the modal localization inductive micro electric field sensor, and the currents output by the two-side sensing structures (3) in the modal localization inductive micro electric field sensor are collected; The ratio of the currents output by the two-side sensing structures (3) is calculated, and based on the mapping relationship between the ratio and the to-be-measured electric field intensity, the intensity value of the to-be-measured electric field is converted.

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