Flexible capacitive pressure sensor and method of manufacture

Abstract

The application discloses a flexible capacitive pressure sensor and a preparation method, relates to the technical field of flexible capacitive pressure sensors, and comprises a shell, a terminal post two arranged at one end of the shell, a shell cover arranged at the other end of the shell and a terminal post one arranged on the shell cover, wherein an upper packaging layer is arranged in the shell, an upper electrode layer is arranged on one side of the upper packaging layer, an intermediate dielectric layer is arranged on one side of the upper electrode layer, a lower electrode layer is arranged on one side of the intermediate dielectric layer, and a lower packaging layer is arranged on one side of the lower electrode layer; conductive film structures are arranged between the lower electrode layer, the upper electrode layer and the intermediate dielectric layer; a sealing assembly is arranged in the shell cover; and an extrusion assembly is further arranged in the shell cover; the sealing assembly is used to improve the sealing performance between the shell and the shell cover, prevent moisture and dust in the outside world from entering the shell, improve the accuracy of capacitive measurement, and further improve the service life of the flexible capacitive pressure sensor.

Description

Technical Field

[0001] This invention relates to the field of flexible capacitive pressure sensor technology, and more particularly to a flexible capacitive pressure sensor and its fabrication method. Background Technology

[0002] Flexible capacitive pressure sensors are sensors that detect pressure based on changes in capacitance. They are flexible and bendable, and are widely used in wearable devices, medical monitoring, and robotics. However, after prolonged use, the seals of existing flexible capacitive pressure sensors may age or crack, resulting in poor sealing performance. This allows external moisture, dust, and other impurities to enter the sensor, affecting the accuracy of capacitance measurements and reducing the sensor's lifespan. Summary of the Invention

[0003] To address the problems in the background art, this invention proposes a flexible capacitive pressure sensor and its fabrication method.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A flexible capacitive pressure sensor includes a housing, a second terminal block disposed at one end of the housing, a housing cover disposed at the other end of the housing, and a first terminal block disposed on the housing cover. The housing has an upper encapsulation layer, an upper electrode layer disposed on one side of the upper encapsulation layer, an intermediate dielectric layer disposed on one side of the upper electrode layer, a lower electrode layer disposed on one side of the intermediate dielectric layer, and a lower encapsulation layer disposed on one side of the lower electrode layer.

[0006] A circular hole is provided inside the terminal block, and a lead wire is provided inside the circular hole, and the lead wire is fixedly connected to the lower electrode layer.

[0007] The circular hole has an annular cavity three, and the annular cavity three is provided with a fixing component for fixing the lead wire.

[0008] A conductive thin film structure is provided between the lower electrode layer, the upper electrode layer and the intermediate dielectric layer;

[0009] The cover is provided with a sealing assembly for sealing the housing;

[0010] The shell cover is also equipped with a compression assembly.

[0011] Preferably, the sealing assembly includes an annular ring disposed on one side of the housing, an annular opening on one side of the housing cover, and an annular cavity II disposed within the annular opening, wherein a sealing capsule is disposed within the annular cavity II and the sealing capsule extends into the annular opening.

[0012] Preferably, a plurality of annular rubber rings are evenly provided on the inner wall of the sealing capsule, and annular grooves are formed on the inner and outer walls of the annular rubber rings to match the annular rubber rings.

[0013] Preferably, the sealed capsule is filled with hydraulic oil.

[0014] Preferably, the extrusion assembly includes multiple annular cavities I opened in the shell cover, cylindrical cavities symmetrically opened on the annular cavities I, and circular grooves I and II respectively opened at the ends of the cylindrical cavities. A connecting rod is slidably arranged in the cylindrical cavity. One end of the connecting rod is provided with a circular plate that cooperates with the circular groove I, and the other end is provided with an extrusion plate that cooperates with the circular groove II. A limiting plate is provided on the outer wall of the connecting rod in the annular cavity I, and a return spring is sleeved on the outer wall of the connecting rod between the limiting plate and the annular cavity I.

[0015] Preferably, the conductive thin film structure includes a flexible substrate and microstructures based on sandpaper molding disposed on both sides of the flexible substrate.

[0016] Preferably, the fixing component includes a sealing cavity symmetrically opened in a circular hole, a fixing plate fixedly connected in the sealing cavity, a piston slidably disposed in the sealing cavity, and a guide rod slidably disposed on the fixing plate. One end of the guide rod is fixedly connected to the piston, and the other end is fixedly connected to an arc-shaped movable plate. An arc plate is slidably disposed on the inner wall of the arc-shaped movable plate. A compression spring is sleeved on the outer wall of the guide rod between the fixing plate and the piston. The sealing cavity is connected to the sealing capsule through a conduit.

[0017] A method for fabricating a flexible capacitive pressure sensor includes the following steps:

[0018] S1: First, place the upper encapsulation layer, upper electrode layer, conductive thin film structure, intermediate dielectric layer, conductive thin film structure, lower electrode layer and lower encapsulation layer in the housing in the following order. Then, solder the leads to the lower electrode layer. Finally, put the cover on the housing and connect the leads to the inside of the cover.

[0019] S2: After the cap is placed on the shell, the annular ring enters the sealing capsule and squeezes the sealing capsule, thereby causing the sealing capsule to wrap around the annular ring, achieving the first seal between the shell and the cap;

[0020] When the sealing capsule is squeezed, the annular rubber ring enters the annular groove on the ring, achieving a second seal between the shell and the cap; through the operation of the first and second seals, the sealing performance between the shell and the cap is further improved.

[0021] S3: When the sealing capsule is squeezed again, it will squeeze the circular plate, which will then drive the connecting rod to move, thereby driving the squeezing plate to move. This will squeeze the lower encapsulation layer, lower electrode layer, conductive film structure, intermediate dielectric layer, upper electrode layer and upper encapsulation layer, avoiding the lower encapsulation layer, lower electrode layer, conductive film structure, intermediate dielectric layer, upper electrode layer and upper encapsulation layer from shaking inside the housing when the flexible capacitive pressure sensor moves. This is beneficial to the use of the flexible capacitive pressure sensor.

[0022] S4: When the sealing capsule is squeezed, the hydraulic oil inside the sealing capsule enters the sealing cavity through the conduit, which in turn pushes the piston to move, thereby driving the guide rod to move, further driving the arc-shaped movable plate and the arc plate to move, and finally, the two arc plates clamp and fix the lead wire.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0024] 1. The present invention improves the sealing performance between the housing and the cover by using a sealing component, preventing external moisture and dust from entering the housing, thus improving the accuracy of capacitance measurement and further extending the service life of the flexible capacitive pressure sensor. The extrusion component facilitates the extrusion of the lower encapsulation layer, lower electrode layer, conductive film structure, intermediate dielectric layer, upper electrode layer, and upper encapsulation layer within the housing, preventing these components from wobbling within the housing during movement, thereby enhancing the usability of the flexible capacitive pressure sensor.

[0025] 2. The present invention uses a fixing component to facilitate the fixation of the internal leads of the flexible capacitive pressure sensor, preventing the leads from falling off during use, thereby ensuring the use of the flexible capacitive pressure sensor and improving its service life; the arc-shaped plate and the arc-shaped movable plate are slidably arranged so that when the arc-shaped plate contacts the leads, it will not cause the leads to rotate, preventing the leads from falling off due to the rotation of the cover, thus facilitating the protection of the leads and benefiting the use of the flexible capacitive pressure sensor. Attached Figure Description

[0026] Figure 1 A schematic diagram of the structure from a frontal view provided according to an embodiment of the present invention is shown;

[0027] Figure 2 A side-view structural schematic diagram is shown according to an embodiment of the present invention;

[0028] Figure 3 A schematic cross-sectional view of the structure provided in an embodiment of the present invention is shown;

[0029] Figure 4 An exploded view is shown according to an embodiment of the present invention;

[0030] Figure 5 for Figure 3 A magnified view of a section at point A in the middle;

[0031] Figure 6 for Figure 3 Enlarged view of part B in the image;

[0032] Figure 7 A schematic diagram of the shell cover provided according to an embodiment of the present invention is shown;

[0033] Figure 8 A cross-sectional structural schematic diagram of the shell cover provided according to an embodiment of the present invention is shown;

[0034] Figure 9 A schematic diagram of a conductive thin film structure provided according to an embodiment of the present invention is shown;

[0035] Figure 10 A schematic diagram of the structure of the fastener provided according to an embodiment of the present invention is shown;

[0036] Figure 11 A schematic diagram of the connection between the arc-shaped plate and the arc-shaped movable plate according to an embodiment of the present invention is shown.

[0037] Legend:

[0038] 1. Housing; 2. Housing cover; 3. Terminal 1; 4. Terminal 2; 5. Lower encapsulation layer; 6. Lower electrode layer; 7. Conductive thin film structure; 701. Flexible substrate; 702. Sandpaper microstructure; 8. Intermediate dielectric layer; 9. Upper electrode layer; 10. Upper encapsulation layer; 11. Sealing capsule; 12. Circular plate; 13. Limiting plate; 14. Annular cavity 1; 15. Return spring; 16. Squeezing plate; 17. Annular ring; 18. Annular rubber ring; 19. Ring 20. Circular groove; 21. Circular opening; 22. Circular cavity two; 23. Circular groove one; 24. Cylindrical cavity; 25. Circular groove two; 26. Hydraulic oil; 27. Connecting rod; 28. Conduit; 29. ​​Sealing cavity; 30. Piston; 31. Fixed plate; 32. Arc plate; 33. Guide rod; 34. Compression spring; 35. Arc movable plate; 36. Circular cavity three; 37. Circular hole; 38. Lead wire; 39. Bending spring; 40. Arc groove; 41. Arc slider. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Please see Figure 1 - Figure 11 The present invention provides a technical solution:

[0041] A flexible capacitive pressure sensor includes a housing 1 made of insulating plastic to prevent leakage and facilitate its use. A terminal 4 is located at one end of the housing 1, a cover 2 is located at the other end of the housing 1, and a terminal 3 is located on the cover 2 for energizing the flexible capacitive pressure sensor. An internal thread is formed on the inner wall of the housing 1, and an external thread that mates with the internal thread is formed on the outer wall of the end of the cover 2, facilitating the connection between the housing 1 and the cover 2.

[0042] The housing 1 contains an upper encapsulation layer 10, an upper electrode layer 9 on one side of the upper encapsulation layer 10, an intermediate dielectric layer 8 on one side of the upper electrode layer 9, a lower electrode layer 6 on one side of the intermediate dielectric layer 8, and a lower encapsulation layer 5 on one side of the lower electrode layer 6. Both the upper encapsulation layer 10 and the lower encapsulation layer 5 are made of polydimethylsiloxane (PDMS). Because PDMS is a flexible material, it makes the upper and lower encapsulation layers 10 and 5 flexible. The upper and lower encapsulation layers 10 and 5 protect the internal lower electrode layer 6, intermediate dielectric layer 8, and upper electrode layer 9, preventing external interference and damage to the flexible capacitive pressure sensor, while also giving the sensor good flexibility and waterproof performance. Both the upper electrode layer 9 and the lower electrode layer 6 are made of conductive polymer materials, which are a mixture of materials with good conductivity and flexibility, such as polyaniline, carbon nanotubes, and graphene. The intermediate dielectric layer 8 is made of a flexible material with a high dielectric constant, such as vinylidene fluoride (PVDF) and its copolymers.

[0043] A circular hole 36 is provided inside the terminal block 3, and a lead wire 37 is provided inside the circular hole 36. The lead wire 37 is fixedly connected to the lower electrode layer 6.

[0044] An annular cavity 35 is provided inside the circular hole 36, and a fixing component is provided inside the annular cavity 35 for fixing the lead wire 37. The use of the fixing component makes it easy to fix the lead wire 37 inside the flexible capacitive pressure sensor, preventing the lead wire 37 from falling off during use, thereby ensuring the use of the flexible capacitive pressure sensor and improving the service life of the flexible capacitive pressure sensor.

[0045] A conductive thin film structure 7 is provided between the lower electrode layer 6 and the upper electrode layer 9 and the intermediate dielectric layer 8. The conductive thin film structure 7 includes a flexible substrate 701 and sandpaper microstructures 702 disposed on both sides of the flexible substrate 701. The conductive thin film structure 7 using sandpaper microstructures 702 forms a conductive layer with a microscopic protrusion and depression structure similar to the surface of sandpaper on the flexible substrate 701. This microstructure enables the effective contact area between the intermediate dielectric layer 8, the upper electrode layer 9 and the lower electrode layer 6 to continuously change. When subjected to pressure, the deformation of the sandpaper microstructure 702 will cause a significant change in the capacitance value, thereby enabling the flexible capacitive pressure sensor to have high sensitivity over a wide range.

[0046] The preparation of the conductive thin film structure 7 involves selecting 80-mesh sandpaper, immersing it in deionized water, and ultrasonically cleaning it for 15 minutes to remove surface impurities and oil. The sandpaper is then placed in an oven and dried at 60°C for 30 minutes. After drying, a layer of silane release agent is uniformly coated onto its surface and allowed to air dry in a ventilated area. Then, conductive materials such as polymers, carbon nanotubes, or graphene are dispersed in a suitable solvent to form a uniform conductive solution. The prepared conductive solution, such as polyaniline, carbon nanotubes, or graphene, is coated onto the treated sandpaper using a spin-coating method at a speed of 2000 rpm for 30 seconds. The sandpaper coated with the conductive solution is then placed in an oven and dried at 80°C for 2 hours to remove the solvent. After drying, the conductive thin film structure 7 is carefully peeled off from the sandpaper, yielding a conductive thin film structure 7 with sandpaper microstructure 702.

[0047] The cover 2 is provided with a sealing component for sealing the housing 1; the use of the sealing component can improve the sealing between the housing 1 and the cover 2, prevent external moisture and dust from entering the housing 1, improve the accuracy of capacitance measurement, and further improve the service life of the flexible capacitive pressure sensor.

[0048] The housing 2 is also equipped with a compression assembly; the use of the compression assembly facilitates the compression between the lower encapsulation layer 5, lower electrode layer 6, conductive thin film structure 7, intermediate dielectric layer 8, upper electrode layer 9 and upper encapsulation layer 10 inside the housing 1, and avoids the lower encapsulation layer 5, lower electrode layer 6, conductive thin film structure 7, intermediate dielectric layer 8, upper electrode layer 9 and upper encapsulation layer 10 shaking inside the housing 1 when the flexible capacitive pressure sensor moves, thereby facilitating the use of the flexible capacitive pressure sensor.

[0049] In this invention, the sealing assembly includes an annular ring 17 disposed on one side of the housing 1, an annular opening 20 formed on one side of the housing cover 2, and an annular cavity 21 formed within the annular opening 20. A sealing capsule 11 is disposed within the annular cavity 21 and extends into the annular opening 20. The sealing capsule 11 is squeezed by the annular ring 17 to wrap around the outer wall of the annular ring 17, thereby achieving the first seal between the housing cover 2 and the housing 1. The sealing capsule 11 is made of rubber, and rubber has high elasticity, which makes the sealing capsule 11 highly elastic, thus facilitating the deformation of the sealing capsule 11 and facilitating the sealing between the housing cover 2 and the housing 1.

[0050] In this invention, a plurality of annular rubber rings 18 are uniformly arranged on the inner wall of the sealing capsule 11. Annular grooves 19 are formed on the inner and outer walls of the annular rings 17 to cooperate with the annular rubber rings 18. Through the cooperation between the annular grooves 19 and the annular rubber rings 18, the contact area between the sealing capsule 11 and the annular rings 17 is increased, thereby improving the sealing performance between the cover 2 and the housing 1, that is, achieving a second seal between the cover 2 and the housing 1. Through the operation of the first and second seals, the sealing performance between the cover 2 and the housing 1 is improved, preventing external dust or moisture from entering the housing 1, thereby improving the service life of the flexible capacitive pressure sensor.

[0051] In this invention, the sealing capsule 11 is filled with hydraulic oil 25; the use of hydraulic oil 25 facilitates the filling of the sealing capsule 11, thereby ensuring that the sealing capsule 11 can drive the fixing member and the extrusion assembly to work after deformation.

[0052] In this invention, the extrusion assembly includes multiple annular cavities 14 formed within the shell cover 2, cylindrical cavities 23 symmetrically formed on the annular cavities 14, and circular grooves 22 and 24 respectively formed at the ends of the cylindrical cavities 23. A connecting rod 26 is slidably disposed within the cylindrical cavity 23. One end of the connecting rod 26 is provided with a circular plate 12 that mates with the circular groove 22. When the circular plate 12 is not extruded, it is positioned in the annular cavity 21 under the action of a return spring 15. The other end is provided with an extrusion plate 16 that mates with the circular groove 24. A limiting plate 13 is provided on the outer wall of the connecting rod 26 within the annular cavity 14 to limit the movement of the connecting rod 26. A return spring 15 is sleeved on the outer wall of the connecting rod 26 between plate 13 and annular cavity 14. The connecting rod 26 is moved by the compression of the circular plate 12 by the sealing capsule 11, which in turn moves the compression plate 16. This achieves compression between the lower encapsulation layer 5, lower electrode layer 6, conductive thin film structure 7, intermediate dielectric layer 8, upper electrode layer 9 and upper encapsulation layer 10, avoiding the lower encapsulation layer 5, lower electrode layer 6, conductive thin film structure 7, intermediate dielectric layer 8, upper electrode layer 9 and upper encapsulation layer 10 shaking in the housing 1 when the flexible capacitive pressure sensor moves, thus facilitating the use of the flexible capacitive pressure sensor.

[0053] In this invention, the fixing component includes a sealing cavity 28 symmetrically formed within a circular hole 36, a fixing plate 30 fixedly connected within the sealing cavity 28, a piston 29 slidably disposed within the sealing cavity 28, and a guide rod 32 slidably disposed on the fixing plate 30. One end of the guide rod 32 is fixedly connected to the piston 29, and the other end is fixedly connected to an arc-shaped movable plate 34. An arc-shaped groove 39 is formed on the inner wall of the arc-shaped movable plate 34. An arc-shaped slider 40 that cooperates with the arc-shaped groove 39 is provided on the outer wall of the arc-shaped plate 34. A bending spring 38 is provided between the arc-shaped slider 40 and the arc-shaped groove 39, and one end of the bending spring 38 is fixedly connected to the arc-shaped slider 40. One end is fixed to the inner wall of the arc-shaped groove 39, which is used to position the arc-shaped plate 31 and facilitate the clamping and fixing of the lead wire 37; a compression spring 33 is sleeved on the outer wall of the guide rod 32 between the fixed plate 30 and the piston 29, and the sealing cavity 28 is connected to the sealing capsule 11 through the conduit 27; wherein, by sliding the arc-shaped plate 31 and the arc-shaped movable plate 34 against each other, the arc-shaped plate 31 will not drive the lead wire 37 to rotate after contacting the lead wire 37, thus avoiding the lead wire 37 from falling off due to rotation, thereby facilitating the protection of the lead wire 37 and facilitating the use of the flexible capacitive pressure sensor.

[0054] Working principle: A method for fabricating a flexible capacitive pressure sensor, comprising the following steps:

[0055] Step 1: First, place the upper encapsulation layer 10, upper electrode layer 9, conductive thin film structure 7, intermediate dielectric layer 8, conductive thin film structure 7, lower electrode layer 6 and lower encapsulation layer 5 in the housing 1 in the following order. Then, solder the lead wire 37 to the lower electrode layer 6. Finally, cover the housing 1 with the cover 2 and connect the lead wire 37 to the inside of the cover 2.

[0056] Step 2: After the shell cover 2 is threaded onto the shell 1, the annular ring 17 enters into the sealing capsule 11 and squeezes the sealing capsule 11, thereby causing the sealing capsule 11 to wrap around the annular ring 17, achieving the first seal between the shell 1 and the shell cover 2.

[0057] When the sealing capsule 11 is squeezed, the annular rubber ring 18 will enter the annular groove 19 on the annular ring 17, achieving a second seal between the shell 1 and the shell cover 2; through the operation of the first seal and the second seal, the sealing performance between the shell 1 and the shell cover 2 is further improved.

[0058] The first and second sealing processes described above improve the sealing performance between housing 1 and cover 2, preventing external dust or moisture from entering housing 1 and thus extending the service life of the flexible capacitive pressure sensor.

[0059] Step 3: When the sealing capsule 11 is squeezed again, it will squeeze the circular plate 12, thereby driving the connecting rod 26 to move, which in turn drives the squeezing plate 16 to move, realizing the squeezing between the lower encapsulation layer 5, the lower electrode layer 6, the conductive thin film structure 7, the intermediate dielectric layer 8, the upper electrode layer 9 and the upper encapsulation layer 10. This avoids the lower encapsulation layer 5, the lower electrode layer 6, the conductive thin film structure 7, the intermediate dielectric layer 8, the upper electrode layer 9 and the upper encapsulation layer 10 shaking inside the housing 1 when the flexible capacitive pressure sensor moves, thus facilitating the use of the flexible capacitive pressure sensor.

[0060] Step 4: When the sealing capsule 11 is squeezed, the hydraulic oil 25 inside the sealing capsule 11 enters the sealing cavity 28 through the conduit 27, thereby pushing the piston 29 to move, which in turn drives the guide rod 32 to move, further driving the arc-shaped movable plate 34 and the arc-shaped plate 31 to move synchronously. Finally, the two arc-shaped plates 31 clamp and fix the lead wire 37. When the two arc-shaped plates 31 come into contact with the lead wire 37, the arc-shaped plates 31 are in a stationary state. As the shell cover 2 rotates, the arc-shaped plates 31 will not rotate, so that the arc-shaped plates 31 will not slide against the lead wire 37. This further avoids the phenomenon of friction between the arc-shaped plates 31 and the lead wire 37 causing damage to the lead wire 37 or the lead wire 37 rotating and causing the lead wire 37 to fall off. This facilitates the protection of the lead wire 37 and is beneficial to the use of flexible capacitive pressure sensors.

[0061] The above description of the embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A flexible capacitive pressure sensor comprising a housing, a terminal post two provided at one end of the housing, a housing cover provided at the other end of the housing, and a terminal post one provided on the housing cover, characterized in that, The shell is internally provided with an upper packaging layer, one side of the upper packaging layer is provided with an upper electrode layer, one side of the upper electrode layer is provided with an intermediate dielectric layer, one side of the intermediate dielectric layer is provided with a lower electrode layer, one side of the lower electrode layer is provided with a lower packaging layer; A circular hole is formed in the terminal post one, a lead wire is arranged in the circular hole, and the lead wire is fixedly connected with the lower electrode layer; An annular cavity three is formed in the circular hole, and a fixing member for fixing the lead wire is arranged in the annular cavity three; The lower electrode layer and the upper electrode layer are both provided with a conductive film structure between the conductive film structure and the intermediate dielectric layer; The shell cover is internally provided with a sealing assembly for sealing the shell; The shell cover is further provided with an extrusion assembly; The sealing assembly comprises an annular ring arranged on one side of the shell, an annular opening formed on one side surface of the shell cover, and an annular cavity two formed in the annular opening, and a sealing capsule is arranged in the annular cavity two and extends into the annular opening; The extrusion assembly comprises a plurality of annular cavities one formed in the shell cover, a cylindrical cavity symmetrically formed on the annular cavity one, and a circular groove one and a circular groove two respectively formed at the end of the cylindrical cavity, a connecting rod is slidably arranged in the cylindrical cavity, one end of the connecting rod is provided with a circular plate matched with the circular groove one, and the other end is provided with an extrusion plate matched with the circular groove two, a limiting plate is arranged on the outer wall of the connecting rod in the annular cavity one, and a return spring is sleeved on the outer wall of the connecting rod between the limiting plate and the annular cavity one; The fixing member comprises a sealing cavity symmetrically formed in the circular hole, a fixing plate fixedly connected in the sealing cavity, a piston slidably arranged in the sealing cavity, and a guide rod slidably arranged on the fixing plate, one end of the guide rod is fixedly connected with the piston, the other end is fixedly connected with an arc-shaped movable plate, an arc-shaped plate is slidably arranged on the inner wall of the arc-shaped movable plate, an extrusion spring is sleeved on the outer wall of the guide rod between the fixing plate and the piston, and the sealing cavity is communicated with the sealing capsule through a conduit.

2. A flexible capacitive pressure sensor according to claim 1, wherein, A plurality of annular rubber rings are uniformly arranged on the inner wall of the sealing capsule, and annular grooves are formed on the inner wall and the outer wall of the annular ring matched with the annular rubber rings.

3. A flexible capacitive pressure sensor according to claim 2, wherein, The sealing capsule is filled with hydraulic oil.

4. A flexible capacitive pressure sensor according to claim 3, wherein, The conductive film structure comprises a flexible substrate and a sandpaper microstructure arranged on both sides of the flexible substrate.

5. A method for manufacturing a flexible capacitive pressure sensor according to any one of claims 1 to 4, characterized in that The method comprises the following steps: S1: sequentially install the upper packaging layer, the upper electrode layer, the conductive film structure, the intermediate dielectric layer, the conductive film structure, the lower electrode layer and the lower packaging layer in the shell, then weld the lead wire and the lower electrode layer together, and finally cover the shell cover on the shell and connect the lead wire with the inside of the shell cover; S2: after the shell cover is covered on the shell, the annular ring enters the sealing capsule and extrudes the sealing capsule, so that the sealing capsule wraps the annular ring, realizing the first sealing between the shell and the shell cover; When the sealing capsule is extruded, the annular rubber ring enters the annular groove on the annular ring, realizing the second sealing between the shell and the shell cover; through the first sealing and the second sealing, the sealing between the shell and the shell cover is further improved; S3: When the sealing capsule is squeezed again, it will squeeze the circular plate, which will then drive the connecting rod to move, thereby driving the squeezing plate to move. This will squeeze the lower encapsulation layer, lower electrode layer, conductive film structure, intermediate dielectric layer, upper electrode layer and upper encapsulation layer, avoiding the lower encapsulation layer, lower electrode layer, conductive film structure, intermediate dielectric layer, upper electrode layer and upper encapsulation layer from shaking inside the housing when the flexible capacitive pressure sensor moves. This is beneficial to the use of the flexible capacitive pressure sensor. S4: When the sealing capsule is squeezed, the hydraulic oil inside the sealing capsule enters the sealing cavity through the conduit, which in turn pushes the piston to move, thereby driving the guide rod to move, further driving the arc-shaped movable plate and the arc plate to move, and finally, the two arc plates clamp and fix the lead wire.

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