Flexible electret electromechanical sensor with micro-displacement amplification effect and preparation method thereof

Abstract

The application provides a flexible electret electromechanical sensor with micro-displacement amplification and a preparation method, and is used for solving the problems of insufficient weak signal detection sensitivity, lack of active micro-displacement amplification mechanism, poor environmental adaptability and insufficient conformal adhesion capability of the existing flexible electret electromechanical sensor. The sensor shell is provided with a first cavity in the upper part and a second cavity in the lower part. The first cavity and the second cavity are communicated through an airflow through hole. An electret film is sealingly arranged at the opening of the first cavity. A conformal film is sealingly arranged at the opening of the second cavity. When the conformal film is displaced and deformed, the gas in the second cavity is compressed. The gas in the second cavity flows to the first cavity through the airflow through hole. Under the action of the directional pressure boosting effect, the electret film is displaced and deformed more than the conformal film. The application realizes micro-displacement amplification through air pressure driving, and greatly improves the weak signal detection sensitivity.

Description

Technical Field

[0001] This invention relates to the field of electromechanical sensors, and in particular to a flexible electret electromechanical sensor with micro-displacement amplification function and its preparation method. Background Technology

[0002] Flexible electromechanical sensors can convert mechanical signals such as displacement and pressure into measurable electrical signals, making them one of the core components of flexible wearable devices, human-computer interaction systems, and soft robots. Among existing technologies, electret-based flexible sensors exhibit significant advantages in passive / low-power sensing due to their charge storage characteristics and piezoelectric-like effects.

[0003] However, the following key limitations still exist: ① Insufficient sensitivity for weak signal detection: For mechanical signals at the micro-displacement level, such as pulse and weak vibration, the deformation amplitude of the sensor's direct response is extremely small, resulting in a low signal-to-noise ratio of the output electrical signal, making it difficult to achieve accurate detection; ② Lack of active micro-displacement amplification mechanism: Existing electret sensors mostly rely on direct deformation response and do not utilize fluid dynamics or structural mechanics principles to amplify the signal, resulting in severe loss of weak signals during the mechanical-to-electrical signal conversion process; ③ Poor environmental adaptability: In humid, sweaty, or liquid contact scenarios, the surface of the electret film is easily contaminated or wetted by liquid, leading to charge leakage and capacitor structure failure, which seriously affects the stability of the sensor; ④ Insufficient conformal bonding capability: The substrate material of most flexible sensors cannot achieve close bonding with complex curved surfaces (such as human skin folds or irregular robot surfaces), which easily leads to signal distortion or false detection.

[0004] Therefore, developing a flexible electret electromechanical sensor that combines pneumatically driven micro-displacement amplification, superhydrophobic and anti-fouling properties, and high conformal bonding capability has become a key problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a flexible electret electromechanical sensor with micro-displacement amplification and its fabrication method. This addresses the technical problems of insufficient sensitivity for weak signal detection, lack of active micro-displacement amplification mechanism, poor environmental adaptability, and insufficient conformal bonding capability in flexible electret electromechanical sensors.

[0006] First, this application provides a flexible electret electromechanical sensor with micro-displacement amplification function, including a sensor housing, a first cavity in the upper part of the sensor housing, and a second cavity in the lower part of the sensor housing;

[0007] The first cavity and the second cavity are connected by an air passage. An electret film is sealed at the opening of the first cavity, and an adhesive film is sealed at the opening of the second cavity. When the adhesive film undergoes displacement deformation, it compresses the gas in the second cavity. The gas in the second cavity flows to the first cavity through the air passage. Under the action of directional pressurization effect, the electret film undergoes a displacement deformation greater than that of the adhesive film. When the electret film undergoes displacement deformation, it outputs an induced electrical signal that is positively correlated with the deformation based on a piezoelectric-like effect.

[0008] Optionally, the first cavity and the electret film, as well as the second cavity and the bonding film, all constitute a sealed cavity, and the cross-sectional area of ​​the first cavity is smaller than the cross-sectional area of ​​the second cavity.

[0009] Optionally, the bonding film is a bonding film conformally to the sensing object.

[0010] Optionally, the bonding film is made of PDMS, silicone, or thermoplastic polyurethane (TPU), and the bonding film is integrally formed with the sensor housing.

[0011] The bonding film is used to achieve gapless bonding with irregular curved surfaces, human skin, or component surfaces, and to convert the minute pressure, micro-vibration, or micro-deformation of the sensing object into vertical micro-displacement of the film without distortion.

[0012] Optionally, the electret film is a multilayer superhydrophobic porous electret film;

[0013] The electret film includes a dielectric layer, an electret layer, an electrode layer, and a superhydrophobic coating. The electret layer, the electrode layer, and the superhydrophobic coating are stacked sequentially from the inside to the outside on both sides of the dielectric layer.

[0014] Optionally, the superhydrophobic coating is a biomimetic micro / nano structure superhydrophobic coating with a water contact angle of not less than 150° and a roll-off angle of not more than 10°.

[0015] The electrode layer is one of the following: silver nanowire or carbon nanotube composite film, PSS conductive polymer film, conductive graphene film, or ultrathin metal film; the electret layer is FEP electret, PTFE electret, or PVDF electret; and the dielectric layer is a porous flexible dielectric layer with a porosity of 30%–60%.

[0016] Optionally, the sensor housing is provided with a gap layer for separating the first cavity and the second cavity;

[0017] The air passage is disposed on the gap layer, and the air passage includes a plurality of micron-sized through holes evenly distributed in an array.

[0018] Optionally, the gap layer is made of a flexible polymer film material; the thickness of the gap layer is 50μm~500μm.

[0019] Optionally, the sensor housing is bonded to the electret film and the spacer layer by oxygen plasma bonding, thermo-press bonding, or adhesive sealing.

[0020] Secondly, this application provides a method for fabricating a flexible electret electromechanical sensor with micro-displacement amplification, which is used to fabricate the aforementioned flexible electret electromechanical sensor with micro-displacement amplification. The specific steps are as follows:

[0021] S1: The sensor housing and the conformal bonding film to the sensing object are integrally formed using a molding method;

[0022] S2: An unopened gap layer is prepared using a molding method, and micron-sized through holes are uniformly arrayed in the gap layer by laser etching process to form air passages;

[0023] S3: Prepare a porous dielectric layer, and stack an electret layer, an electrode layer and a superhydrophobic coating layer sequentially from the inside to the outside on both sides of the dielectric layer to obtain an electret thin film;

[0024] S4: The sensor housing with the bonding film is flexibly encapsulated with the gap layer and electret film.

[0025] Because of the adoption of the above technical solution, the present invention has the following advantages:

[0026] 1. This application uses a pneumatic coupling structure consisting of a "coated film, spacer layer, airflow hole and electret film" to convert the initial micro-displacement into airflow pressurization, which drives the electret film to produce amplified deformation, thus solving the problem of insufficient sensitivity in weak signal detection and greatly improving the sensitivity in weak signal detection.

[0027] 2. This application uses flexible materials such as PDMS and TPU to prepare a bonding film that conformally fits the sensing object, which can achieve gapless bonding with human skin and irregular component surfaces, avoiding signal distortion caused by poor contact.

[0028] 3. The biomimetic superhydrophobic coating on the surface of the electret film of this application has moisture-proof, oil-proof and self-cleaning functions, which can effectively resist environmental interference such as sweat, moisture and dust, and improve the long-term stability of the sensor in complex scenarios.

[0029] 4. This application uses electret materials to achieve passive operation, eliminating the need for an external power supply, thus reducing the power consumption and system complexity of the sensor. It has broad application prospects in wearable physiological monitoring, soft robot tactile perception, and industrial weak vibration detection.

[0030] 5. This application ensures the airtightness of the air chamber through a flexible packaging structure and sealing bonding process. At the same time, the flexible material of the multi-layer structure is suitable for repeated bending and deformation in use scenarios, which improves the mechanical reliability and service life of the sensor.

[0031] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0032] The accompanying drawings of this invention are described below.

[0033] Figure 1 This is a schematic diagram of the structure of the flexible electret electromechanical sensor of the present invention.

[0034] Figure 2 For the present invention Figure 1 Sectional view at point A-A'.

[0035] Figure 3 This is a schematic diagram of the layered structure of the electret thin film of the present invention.

[0036] Figure 4 This is a logic block diagram of the method for fabricating the flexible electret electromechanical sensor of the present invention.

[0037] Figure 5 This is a simulation diagram of the displacement of the bonding film and the electret film of the present invention and the corresponding fluid velocity field in the cavity.

[0038] Figure 6 The response curve of the output voltage of the flexible electret electromechanical sensor of the present invention as a function of displacement.

[0039] Figure 7 The output voltage stability test diagram of the flexible electret electromechanical sensor of this invention in an environment with a humidity of 85%RH.

[0040] In the figure: 1-sensor housing; 2-first cavity; 3-second cavity; 4-airflow hole; 5-adhesion film; 6-electret film; 601-superhydrophobic coating; 602-electrode layer; 603-electret layer; 604-dielectric layer; 7-gap layer. Detailed Implementation

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments. The terms "upper," "lower," "vertical," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "connected" and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, an integral connection, an electrical connection, or a signal connection; they can refer to a direct connection or an indirect connection through an intermediate medium.

[0042] Example 1:

[0043] like Figure 1 and Figure 2 The flexible electret electromechanical sensor with micro-displacement amplification function shown includes a sensor housing 1, and a gap layer 7 is provided inside the sensor housing 1, which divides the sensor housing 1 into an upper first cavity 2 and a lower second cavity 3.

[0044] The gap layer 7 is provided with a plurality of uniformly arrayed micron-sized through holes, which together form an air passage 4 for connecting the first cavity 2 and the second cavity 3. An electret film 6 is sealed at the opening of the first cavity 2, and an adhesive film 5 is sealed at the opening of the second cavity 3. When the adhesive film 5 undergoes displacement deformation, it compresses the gas in the second cavity 3. The gas in the second cavity 3 flows to the first cavity 2 through the air passage 4. Under the action of directional pressurization effect, the electret film 6 undergoes a displacement deformation greater than that of the adhesive film 5. When the electret film 6 undergoes displacement deformation, it outputs an induced electrical signal that is positively correlated with the deformation based on the piezoelectric effect.

[0045] In this embodiment, the sensor housing 1 is used to fix the various layers of the structure and provide mechanical support, so as to maintain the overall flexibility and structural stability of the sensor.

[0046] In this embodiment, the bonding film 5 is a fully flexible elastic bonding film conformally to the sensing object, used to bond to the surface of the object to be measured and to sense external forces to generate initial micro-displacement deformation; the bonding film 5 is made of PDMS, silicone or thermoplastic polyurethane (TPU), and the bonding film 5 is integrally formed with the sensor housing 1; the bonding film 5 is used to achieve gapless bonding with irregular curved surfaces or human skin or component surfaces, and to convert the small pressure, micro-vibration or micro-deformation of the sensing object into vertical micro-displacement of the film without distortion.

[0047] In this embodiment, the first cavity 2 and the electret film 6, as well as the second cavity 3 and the bonding film 5, all constitute sealed cavities. The cross-sectional area of ​​the first cavity 2 is smaller than that of the second cavity 3. When the second cavity 3 is compressed by the bonding film 5 and its volume changes, the internal airflow flows directionally into the first cavity 2 through the airflow hole array, driving the electret film 6 to produce an amplified deformation greater than the initial micro-displacement, thereby realizing the micro-displacement air pressure coupling amplification effect.

[0048] In this embodiment, the gap layer 7 is made of a flexible polymer film material; the thickness of the gap layer 7 is 50μm~500μm; the sensor housing 1 is bonded to the electret film 6 and the gap layer 7 by oxygen plasma bonding, hot pressing bonding or adhesive sealing (flexible encapsulation adhesive or PI encapsulation film or PDMS encapsulation layer).

[0049] like Figure 3 As shown, the electret film 6 is a multilayer superhydrophobic porous electret film; the electret film 6 includes a dielectric layer 604, an electret layer 603, an electrode layer 602 and a superhydrophobic coating 601, and the electret layer 603, the electrode layer 602 and the superhydrophobic coating 601 are stacked sequentially from the inside to the outside on both sides of the dielectric layer 604.

[0050] The superhydrophobic coating 601 is a biomimetic micro / nano structure superhydrophobic coating with a water contact angle of not less than 150° and a roll-off angle of not more than 10°; the electrode layer 602 is one of silver nanowire or carbon nanotube composite film, PSS conductive polymer film, conductive graphene film, or ultrathin metal film; the electret layer 603 is FEP electret, PTFE electret, or PVDF electret; the dielectric layer 604 is a porous flexible dielectric layer with a porosity of 30%–60% to improve dielectric constant, flexibility, and deformation response sensitivity.

[0051] In this embodiment, the superhydrophobic coating 601 is prepared using flexible PDMS as a substrate and replicated using a lotus leaf template, possessing hydrophobic, oil-repellent, self-cleaning, and moisture-proof / dust-proof functions; the electrode layer 602 possesses high conductivity, high flexibility, and high bending stability; the electret layer 603 has high charge storage density and high charge stability, and can generate an induced potential to output an electrical signal when the film deforms; the dielectric layer 604 is based on PDMS, doped with BaTiO3, TiO2, or SiO2 nanoparticles, and forms a porous structure by using a foaming agent to create pores.

[0052] The working principle of the flexible electret electromechanical sensor in this application is as follows:

[0053] When the object under test experiences micro-pressure, micro-vibration, or micro-deformation, the conformal film 5 of the sensing object first senses the external force and generates an initial micro-displacement, compressing the second cavity 3. The airflow in the second cavity 3 flows directionally into the first cavity 2 through the airflow holes 4 on the gap layer 7. Due to the directional pressurization effect of the airflow, and the fact that the cross-sectional area of ​​the first cavity 2 is smaller than that of the second cavity 3, the gas drives the electret film 6 to generate an amplified deformation much larger than the initial micro-displacement. During the deformation process, the electret film 6 outputs an induced electrical signal that is positively correlated with the deformation amount based on a piezoelectric effect, achieving high-sensitivity detection of weak signals.

[0054] In summary, the flexible electret electromechanical sensor of this application is a fully flexible, self-powered structure that does not require an external power supply. It can achieve high-sensitivity detection of micro-displacement, micro-pressure, and micro-vibration, and is suitable for wearable physiological monitoring, soft robot tactile sensing, human-computer interaction, and industrial weak vibration detection.

[0055] Example 2:

[0056] like Figure 4 The method shown is for fabricating a flexible electret electromechanical sensor with micro-displacement amplification capability. This sensor is used to fabricate a flexible electret electromechanical sensor for sensing micro-displacements of the temporalis and masseter muscles. The flexible electret electromechanical sensor is integrally adapted to the curved surfaces of the temporalis and masseter muscles of the human face, enabling precise sensing of weak micro-displacements, micro-deformations, and micro-vibrations generated by chewing, biting, and teeth grinding movements, achieving low-power passive sensing detection. The specific steps are as follows:

[0057] S1: The sensor housing 1 and the conformal bonding film 5, which is integrally formed with the sensing object, are manufactured using a molding method; the specific steps are as follows:

[0058] S1.1: The PDMS adhesive film 5 and sensor housing 1, which are adapted to the curved surface of the temporalis and masseter muscles of the human face, are integrally molded using the molding method. The PDMS prepolymer and curing agent in the matrix PDMS material are uniformly mixed in a weight ratio of 10:1.

[0059] S1.2: Pour the fully stirred and vacuum degassed PDMS matrix mixture into a custom-made maxillofacial profiling mold. The mold is made by cutting polymethyl methacrylate (PMMA) blocks with a laser cutting machine to match the facial contour curvature of the temporalis and masseter muscles.

[0060] S1.3: Place the mold filled with PDMS mixture into a vacuum drying oven at 60℃~80℃ and heat to cure for 2.5~3h. After natural cooling, demold to obtain a PDMS sensor housing 1 with a bonding film 5 that can closely fit the bite area of ​​the face.

[0061] In this embodiment, PDMS material can be replaced with flexible elastic materials such as silicone or thermoplastic polyurethane (TPU).

[0062] S2: An unopened gap layer 7 is prepared using a molding method, and micron-sized through holes are uniformly arrayed in the gap layer 7 by laser etching process to form air passages 4;

[0063] In this embodiment, the gap layer 7 is made of various flexible polymer insulating films. The shape and array arrangement of the air passages, the thickness of the gap layer and other process parameters can be flexibly adjusted according to the different jaw and facial contours of the human body and the sensitivity requirements for detecting occlusal micro-displacement.

[0064] S3: Prepare a porous dielectric layer 604, and sequentially stack an electret layer 603, an electrode layer 602, and a superhydrophobic coating 601 on both sides of the dielectric layer 604 from the inside out to obtain an electret film 6; the specific steps are as follows:

[0065] S3.1: Using PDMS as the matrix, doping with 10 wt% BaTiO3 nanoparticles, adding a foaming agent, mixing and then spin-coating, heating and curing in a vacuum drying oven at 60℃~80℃ and foaming, a porous dielectric layer 604 with a thickness of 250 μm and a porosity of about 40% is obtained.

[0066] S3.2: Use a 50 μm thick FEP film as an electret layer 603, and attach two electret layers 603 to both sides of the dielectric layer 604 respectively;

[0067] S3.3: Deposit a 100 nm thick silver nanowire / carbon nanotube composite conductive film on the surface of electret layer 603;

[0068] S3.4: Using PDMS as a substrate, a lotus leaf micro-nano structure template is replicated and then subjected to low surface energy fluorination treatment to obtain a superhydrophobic coating with a water contact angle of about 155° and a roll-off angle of about 8°.

[0069] S3.5: Through oxygen plasma bonding process, a tightly composite superhydrophobic porous electret film is formed.

[0070] In this embodiment, the electret layer 603 can be replaced with high-performance electret dielectric materials such as PTFE and PVDF; the electrode material can be replaced with PEDOT:PSS conductive polymer, graphene, or ultrathin metal film.

[0071] S4: The sensor housing 1 with the bonding film 5 is flexibly encapsulated with the gap layer 7 and the electret film 6; the specific steps are as follows:

[0072] S4.1: The sensor housing 1 with bonding film 5, the gap layer 7 with air passage 4, and the multilayer composite superhydrophobic porous electret film 6 are sealed and bonded to each other using PDMS pre-curing liquid; the overall edge gap of the sensor is fully encapsulated with flexible encapsulating adhesive or PDMS pre-curing liquid to ensure the airtightness of the first and second air chambers.

[0073] S4.2: Place the assembled device in a vacuum drying oven at 60℃~80℃ and heat to cure for 1~2 hours. After full curing and shaping, a prototype of a flexible electret electromechanical sensor is finally obtained that can be attached to the temporalis and masseter muscles of the human body for biting action, chewing movement and nighttime micro-displacement monitoring of molars.

[0074] In this embodiment, the fabricated sensor is a fully flexible passive structure that can conformally fit the irregular curved surfaces of the temporalis and masseter muscles of the human face without gaps. During operation, the sensor utilizes the chamber pressure coupling and airflow regulation through the air passages to amplify the weak initial micro-displacements generated by biting and chewing movements. The simulation results of the thin-film deformation under pressure drive are as follows: Figure 5 As shown, the amplification effect of the structure on the initial micro-displacement is intuitively verified; the amplified deformation can drive the electret film to produce significant deformation, outputting a stable induced electrical signal. The response curve of the sensor output voltage as a function of displacement is shown in the figure. Figure 6 As shown, it exhibits good linearity and sensitivity. Meanwhile, the biomimetic superhydrophobic coating on the electret film surface endows the sensor with moisture-proof, sweat-proof, and self-cleaning properties. The output voltage stability test results after 3 days of continuous use in an environment with 85% RH are as follows: Figure 7 As shown, the signal amplitude did not decrease significantly, demonstrating the long-term reliability of the device in facial attachment scenarios.

[0075] In summary, this sensor can accurately achieve highly sensitive non-invasive monitoring of biting force, mandibular micro-displacement, chewing rhythm, and sleep bruxism behavior, and is suitable for various scenarios such as orthodontic monitoring, temporomandibular joint health assessment, and sleep maxillofacial behavior monitoring.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A flexible electret electromechanical sensor with micro-displacement amplification function, characterized in that, The sensor housing (1) includes a first cavity (2) in the upper part of the sensor housing (1) and a second cavity (3) in the lower part of the sensor housing (1). The first cavity (2) and the second cavity (3) are connected by an air passage (4). An electret film (6) is sealed at the opening of the first cavity (2), and an adhesive film (5) is sealed at the opening of the second cavity (3). When the adhesive film (5) undergoes displacement deformation, it compresses the gas in the second cavity (3). The gas in the second cavity (3) flows to the first cavity (2) through the air passage (4). Under the action of directional pressurization effect, the electret film (6) undergoes displacement deformation greater than that of the adhesive film (5). When the electret film (6) undergoes displacement deformation, it outputs an induced electrical signal that is positively correlated with the deformation based on a piezoelectric effect.

2. The flexible electret electromechanical sensor with micro-displacement amplification function according to claim 1, characterized in that, The first cavity (2) and the electret film (6) and the second cavity (3) and the bonding film (5) all constitute sealed cavities, and the cross-sectional area of ​​the first cavity (2) is smaller than the cross-sectional area of ​​the second cavity (3).

3. The flexible electret electromechanical sensor with micro-displacement amplification function according to claim 1, characterized in that, The bonding film (5) is a bonding film conformally to the sensing object.

4. The flexible electret electromechanical sensor with micro-displacement amplification function according to claim 1 or 3, characterized in that, The bonding film (5) is made of PDMS, silicone or thermoplastic polyurethane (TPU), and the bonding film (5) is integrally formed with the sensor housing (1). The bonding film (5) is used to achieve gapless bonding with irregular curved surfaces or human skin or component surfaces, and to convert the small pressure, micro-vibration or micro-deformation of the sensing object into vertical micro-displacement of the film without distortion.

5. The flexible electret electromechanical sensor with micro-displacement amplification function according to claim 1, characterized in that, The electret film (6) is a multilayer superhydrophobic porous electret film; The electret film (6) includes a dielectric layer (604), an electret layer (603), an electrode layer (602), and a superhydrophobic coating (601). The dielectric layer (604) is provided with the electret layer (603), the electrode layer (602), and the superhydrophobic coating (601) stacked sequentially from the inside to the outside on both sides.

6. The flexible electret electromechanical sensor with micro-displacement amplification function according to claim 5, characterized in that, The superhydrophobic coating (601) is a biomimetic micro-nano structure superhydrophobic coating with a water contact angle of not less than 150° and a roll-off angle of not more than 10°. The electrode layer (602) is one of the following: silver nanowire or carbon nanotube composite film, PSS conductive polymer film, conductive graphene film, or ultrathin metal film; the electret layer (603) is FEP electret, PTFE electret, or PVDF electret; and the dielectric layer (604) is a porous flexible dielectric layer with a porosity of 30%–60%.

7. The flexible electret electromechanical sensor with micro-displacement amplification function according to claim 1 or 2, characterized in that, The sensor housing (1) is provided with a gap layer (7) for separating the first cavity (2) and the second cavity (3). The air passage (4) is disposed on the gap layer (7), and the air passage (4) includes a number of micron-sized through holes evenly distributed in an array.

8. The flexible electret electromechanical sensor with micro-displacement amplification function according to claim 7, characterized in that, The gap layer (7) is made of a flexible polymer film material; the thickness of the gap layer (7) is 50μm~500μm.

9. The flexible electret electromechanical sensor with micro-displacement amplification function according to claim 7, characterized in that, The sensor housing (1) is bonded to the electret film (6) and the gap layer (7) by oxygen plasma bonding, hot pressing bonding or adhesive sealing.

10. A method for fabricating a flexible electret electromechanical sensor with micro-displacement amplification capability, characterized in that, The specific steps for preparing the flexible electret electromechanical sensor with micro-displacement amplification as described in any one of claims 1-9 are as follows: S1: The sensor housing (1) and the conformal bonding film (5) that is conformal to the sensing object are integrally formed by the molding method. S2: An unopened gap layer (7) is prepared by molding, and micron-sized through holes are uniformly distributed in the gap layer (7) by laser etching process to form air passages (4). S3: Prepare a porous dielectric layer (604), and stack an electret layer (603), an electrode layer (602) and a superhydrophobic coating (601) sequentially from the inside to the outside on both sides of the dielectric layer (604) to obtain an electret film (6). S4: The sensor housing (1) with the bonding film (5) is flexibly encapsulated with the gap layer (7) and the electret film (6).

Images