A thin-film micro pressure sensor

Abstract

The present invention discloses a thin-film micro pressure sensor, belonging to the technical field of pressure sensors. The thin-film micro pressure sensor includes at least a pair of diaphragms arranged oppositely, and a QTC material and a detection electrode are respectively provided on the opposite surfaces of the two diaphragms; one of the diaphragms is deformable and the other is not deformable; the deformable diaphragm is connected with a force conduction unit, and the force conduction unit includes a cavity and a filling liquid filled therein; the force conduction unit is used for receiving an external force pressing and conducting the external force to the deformable diaphragm, so that the deformable diaphragm deforms with the connection point as the center, and further enables the two diaphragms to be mutually close or far away. The present invention utilizes the property of isotropic liquid conduction. Even if a finger acts on different positions of the sensor diaphragm or acts on the sensor diaphragm in different postures, the effect of uniform conduction can be achieved under the action of the filling liquid, ensuring the accuracy and consistency of measurement.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure sensors, and in particular to a thin-film micro pressure sensor. Background Art

[0002] A pressure transducer is a device or apparatus that can sense a pressure signal and convert the pressure signal into an available output electrical signal according to a certain rule. At present, thin-film pressure sensors have emerged on the market, that is, a pressure-sensitive material is provided between the opposite surfaces of two membranes. By squeezing the membrane, the pressure and contact area between the two membranes are changed, thereby realizing the measurement of pressure.

[0003] However, the existing thin-film pressure sensors have the problem of poor consistency in use. When the finger touches at different points, due to the different postures of the finger relative to the membrane, even under the same pressure, different pressure values may be measured, resulting in inaccurate measurement; when the human hand directly transmits pressure, there is an uneven problem.

[0004] In view of this, a new technical solution is urgently needed to solve the above technical problems. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems existing in the above-mentioned prior art, and provide a thin-film micro pressure sensor.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A thin-film micro pressure sensor includes at least a pair of membranes arranged oppositely, and a QTC material and a detection electrode are respectively provided on the opposite surfaces of the two membranes; one of the membranes is set to be deformable, and the other membrane is set to be non-deformable; the deformable membrane is also connected with a force conduction unit, and the force conduction unit includes a closed cavity and a filling liquid filled therein;

[0008] The force conduction unit is used to receive an external force pressing and conduct the external force to the deformable membrane, so that the deformable membrane deforms with the connection point as the center, and further makes the two membranes close to or away from each other.

[0009] As a further improvement, the thin-film micro pressure sensor further includes a sensor body, and at least one side of the sensor body is provided with an inner cavity, an outer cavity and a channel communicating the two;

[0010] The membrane is arranged in the inner cavity; the force conduction unit is arranged in the communicating cavity formed by the inner cavity, the channel and the outer cavity.

[0011] As a further improvement, the non-deformable diaphragm is attached to the bottom wall of the inner cavity, and the bottom wall is a rigid wall;

[0012] The deformable diaphragm is suspended in the inner cavity, and the edge of the deformable diaphragm is sealingly connected to the inner side wall of the inner cavity;

[0013] An elastic membrane is provided at the opening of the outer cavity, and the edge of the elastic membrane is sealingly connected to the inner peripheral wall of the outer cavity;

[0014] The closed cavity between the elastic membrane and the deformable diaphragm forms the accommodating cavity.

[0015] As a further improvement, the deformable diaphragm is attached to the bottom wall of the inner cavity, and the bottom wall is a flexible wall;

[0016] The non-deformable diaphragm is attached to the top wall of the inner cavity, and the top wall is arranged as an arc protruding towards the bottom wall;

[0017] An elastic membrane is provided at the opening of the outer cavity, and the edge of the elastic membrane is sealingly connected to the inner peripheral wall of the outer cavity;

[0018] The closed cavity between the elastic membrane and the deformable diaphragm forms the accommodating cavity.

[0019] As a further improvement, the filling liquid is silicone oil, glycerol or any non-conductive liquid.

[0020] As a further improvement, the detection electrode includes a plurality of conductive rods arranged at intervals, and two adjacent conductive rods are respectively connected to a positive lead and a negative lead; all the conductive rods form a detection area.

[0021] As a further improvement, the detection area is circular, rectangular or any geometric shape.

[0022] As a further improvement, the conductive rod is a carbon rod.

[0023] As a further improvement, the sensor body is flat, and the axis of the channel is perpendicular to the plane where the sensor body is located.

[0024] As a further improvement, the number of the channels is set to one, and the channel is located on the central axis of the sensor body;

[0025] Alternatively, the number of the channels is set to multiple, and the multiple channels are symmetrically distributed around the central axis of the sensor body.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The thin-film micro pressure sensor of the present invention includes at least a pair of diaphragms arranged oppositely. On the opposite surfaces of the two diaphragms, a PTC material and a detection electrode are respectively arranged, and they are in close contact or away from each other, so as to realize the detection of external pressure. The force conduction unit of the present invention includes a cavity and a filling liquid filled therein. The external pressure acting on the sensor is absorbed by the filling liquid. Even if the finger acts on different positions of the sensor diaphragm, or the finger acts on the sensor diaphragm in different postures, the effect of uniform conduction can be achieved under the action of the filling liquid, ensuring the accuracy and consistency of measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0029] Figure 1 Shows a structural cross-sectional view of the thin-film micro pressure sensor according to Embodiment 1 of the present invention;

[0030] Figure 2 Shows a state schematic diagram of the thin-film micro pressure sensor according to Embodiment 1 of the present invention under pressure;

[0031] Figure 3 Shows a structural schematic diagram of the detection electrode of the thin-film micro pressure sensor according to Embodiment 1 of the present invention;

[0032] Figure 4 Shows a structural cross-sectional view of the thin-film micro pressure sensor according to Embodiment 2 of the present invention;

[0033] Figures 5 to 7 Shows three state schematic diagrams of the thin-film micro pressure sensor according to Embodiment 2 of the present invention under the conditions of left-side force, right-side force, and both-side forces;

[0034] Figure 8 Shows a structural cross-sectional view of the thin-film micro pressure sensor according to Embodiment 3 of the present invention;

[0035] Figure 9 Shows a state schematic diagram of the thin-film micro pressure sensor according to Embodiment 3 of the present invention under pressure;

[0036] Figure 10 Shows a structural cross-sectional view of the thin-film micro pressure sensor according to Embodiment 4 of the present invention;

[0037] Figure 11 Shows a state schematic diagram of the thin-film micro pressure sensor according to Embodiment 4 of the present invention under the condition of left-side force.

[0038] Description of Main Component Symbols:

[0039] 1 - Sensor body; 11 - Inner cavity; 111 - Inner side wall; 12 - Outer cavity; 121 - Inner peripheral wall; 13 - Channel; 14 - Bottom wall; 15 - Elastic membrane; 16 - Top wall; 21 - Deformable diaphragm; 22 - Non - deformable diaphragm; 31 - Chamber; 50 - Detection electrode; 51 - Carbon rod; 52 - Positive lead; 53 - Negative lead. Specific Embodiment

[0040] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

[0041] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

[0042] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0043] In the present invention, unless otherwise clearly defined and limited, the terms "mounted", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply indicates that the horizontal height of the first feature is less than that of the second feature.

[0045] The core of the present invention is to add a force conduction unit including a filling liquid to the thin-film micro pressure sensor. The main principle of the force conduction unit is to utilize the absorption and dispersion of pressure by the liquid to achieve the effect of uniformly conducting the external pressure, so as to solve the problems of uneven pressure conduction and inaccurate measurement values at various places caused by the direct action of the finger on the sensor in the prior art.

[0046] Embodiment 1

[0047] Please refer to Figure 1 and Figure 2 , this embodiment provides a thin-film micro pressure sensor, including a sensor body 1, and a pair of diaphragms and a force conduction unit arranged on the sensor body 1. The following description is with reference to the orientation of Figure 1 .

[0048] Specifically, one side of the sensor body 1 is provided with an inner cavity 11, an outer cavity 12 and a channel 13 communicating the two. The sensor body 1 is made of a rigid insulating material, such as plastic, glass, etc.

[0049] One of the pair of diaphragms is set to be deformable, and the other is set to be non-deformable. The deformation means that the diaphragm changes its shape in the normal direction under an external force.

[0050] Among them, the deformable diaphragm 21 is suspended in the inner cavity 11, and the edge of the deformable diaphragm 21 is hermetically connected to the inner side wall 111 of the inner cavity 11.

[0051] The non-deformable diaphragm 22 is attached to the bottom wall 14 of the inner cavity 11. The bottom wall 14 is made of the same material as the sensor body 1, and the bottom wall 14 is a rigid wall.

[0052] Specifically in this embodiment, a detection electrode 50 is provided on the lower surface of the deformable diaphragm 21, and a QTC material is coated on the upper surface of the non-deformable diaphragm 22. It can be understood that in other embodiments, the detection electrode 50 and the QTC material can be arranged in an exchanged manner.

[0053] The force conduction unit includes a sealed cavity 31 and a filling liquid (not marked in the figure) filled in the cavity 31.

[0054] Specifically, an elastic membrane 15 is provided at the opening of the outer cavity 12 of the sensor body 1, and the edge of the elastic membrane 15 is hermetically connected to the inner peripheral wall 121 of the outer cavity 12. The elastic membrane 15 can be made of a membrane with certain elasticity and wear resistance, such as a silicon membrane.

[0055] The closed cavity between the elastic membrane 15 and the deformable membrane 21 forms the cavity 31 of the force conduction unit, and the cavity 31 is filled with a filling liquid. The filling liquid can be any non-conductive liquid, such as silicone oil, glycerol, etc.

[0056] The upper end of the force conduction unit is used to receive external force pressing, that is, the finger acts on the elastic membrane 15; the external force is absorbed by the filling liquid and conducted to the deformable membrane 21, and the deformable membrane 21 deforms around the connection point under the action of the external force, so that the two membranes change from the position of being away from each other to the position of being close to each other. Since the QTC material and the detection electrode 50 are arranged between the two membranes, the pressure and contact area between the two are changed, so that the corresponding sensing signal can be measured.

[0057] In the thin-film micro-pressure sensor of this embodiment, the external pressure is absorbed and conducted by the filling liquid of the force conduction unit. By using the property that the conduction of force by the liquid is isotropic, even if the finger acts on different positions of the sensor membrane, or the finger acts on the sensor membrane in different postures, the uniform conduction effect can be achieved under the conduction action of the filling liquid, ensuring the accuracy and consistency of the measurement.

[0058] It should be noted that the QTC material refers to Quantum Tunnelling Composite (abbreviated as QTC), which is a new type of force-sensitive material that has appeared on the market. It can sense the pressure and contact area between two membranes, and then output a measurable resistance value. Generally speaking, the greater the pressure and the contact area between the two membranes, the smaller the measured resistance value; on the contrary, the larger the measured resistance value.

[0059] Please refer to Figure 3 , the detection electrode 50 includes a plurality of conductive rods arranged at intervals, and adjacent two of the conductive rods are respectively connected to a positive lead 52 and a negative lead 53; all the conductive rods form a detection area.

[0060] Specifically, in this embodiment, the conductive rod is a carbon rod 51, and the detection area formed by all the carbon rods 51 is circular.

[0061] The working principle of the detection electrode 50 and the QTC material is as follows: As long as two adjacent carbon rods 51 are in contact with the QTC material at the same time, a detection circuit can be formed, and the corresponding resistance value can be measured by an instrument.

[0062] Press the two diaphragms to make them close to each other, so that the QTC material is in close contact with multiple carbon rods 51. The corresponding resistance values can be measured under different pressures and contact areas. The magnitude of the external pressure is calculated by the change in the resistance value.

[0063] The measurement principle and process of this embodiment are described as follows:

[0064] Apply pressure F from top to bottom. The pressure F acts on the elastic membrane 15, causing the filling liquid to flow from the outer cavity 12 to the inner cavity 11. The deformable diaphragm 21 bulges downward under the push of the filling liquid, thereby driving the carbon rod 51 thereon to be in close contact with the QTC material of the non-deformable diaphragm 22. During this process, the resistance value changes gradually. At equilibrium, the change amount of the resistance value can be measured.

[0065] It should be noted that the deformable diaphragm 21 has a certain elastic strength, which is sufficient to support the gravity of the filling liquid. That is, in the absence of external force, the diaphragm will not have obvious deformation.

[0066] Embodiment Two

[0067] Please refer to Figures 4 to 7 , this embodiment provides a thin-film micro pressure sensor, including a sensor body 1, and two pairs of diaphragms and two force conduction units arranged on the sensor body 1. The following description is based on Figure 4 the orientation of

[0068] Specifically, inner cavities 11, outer cavities 12 and channels 13 connecting the two are provided on both the left and right sides of the sensor body 1 of this embodiment. The settings on both sides are symmetric, and the setting situation on each side is the same as that in Embodiment One.

[0069] As Figure 4 shown, the inner cavities 11 on the left and right sides share a bottom wall 14, and this bottom wall 14 is a rigid wall, that is, non-deformable. Non-deformable diaphragms 22 are attached to both the left and right side surfaces of the bottom wall 14, and the QTC material is coated on both non-deformable diaphragms 22.

[0070] A deformable diaphragm 21 is provided in the middle of the left and right inner cavities 11. This deformable diaphragm 21 can deform in the left and right directions. Specifically, the edge of the deformable diaphragm 21 is sealingly connected to the inner side wall 111 of the corresponding inner cavity 11.

[0071] An elastic membrane 15 is correspondingly disposed at the opening of the left and right outer cavities 12 , and the edge of the elastic membrane 15 is sealedly connected to the inner peripheral wall 121 of the corresponding outer cavity 12 .

[0072] The closed cavity between the elastic membrane 15 and the deformable diaphragm 21 on the same side forms a cavity 31 of the lateral force transmission unit, and the cavity 31 is filled with a filling liquid.

[0073] When the thin film micro-pressure sensor of this embodiment is in use, the structures on both sides work independently and the measurement results can be superimposed, thereby increasing the total measurement value.

[0074] The specific measurement process is described as follows:

[0075] 1) Please refer to Figure 5 , a pressure F is applied on the left side to act on the elastic membrane 15, and the elastic membrane 15 on the left side is deformed to the right, squeezing the filling liquid from the outer cavity 12 to the inner cavity 11. The deformable diaphragm 21 is pushed by the filling liquid to bulge to the right, thereby driving the carbon rod 51 thereon and the QTC material on the bottom wall 14 on this side to fit closely to each other, so that the change in resistance value can be measured.

[0076] 2) Please refer to Figure 6 , the situation on the right side is the same as that on the left side, and will not be repeated here.

[0077] 3) Please refer to Figure 7 When the finger applies pressure F to the sensor from both sides at the same time, assuming that the resistance change measured by the structure on the left is ΔR1, and the resistance change measured by the structure on the right is ΔR2, then the resistance change measured by the entire sensor is ΔR1+ΔR2. Under the same pressure, the entire sensor can obtain about twice the measurement value, thereby improving the detection sensitivity of the sensor to a certain extent.

[0078] In the above two embodiments, there is only one channel 13, and the channel 13 is located on the central axis of the sensor body 1. The point of application of the external pressure F can be any point on the elastic membrane 15, but after the conduction of the filling liquid, the pressure values ​​received by each point on the deformable diaphragm 21 are equal, and are equal to the pressure F; at the same time, the deformable diaphragm 21 will deform with the connection point as the center, and the connection point refers to the intersection point of the axis of the channel 13 and the deformable diaphragm 21, that is, the position where the diaphragm is deformed remains unchanged, thereby avoiding the problem of different measurement values ​​caused by the external pressure F acting on different application points.

[0079] Of course, in some other embodiments, a plurality of the channels 13 may be provided. The plurality of channels 13 are symmetrically distributed around the central axis of the sensor body 1. Similar to the case where one channel 13 is provided, the point of application of the external pressure F can be any point on the elastic membrane 15. Through the conduction of the filling liquid, the pressure values received by each point on the deformable diaphragm 21 are equal and all equal to the pressure F. At the same time, the deformable diaphragm 21 will deform with multiple connection points as the center. The multiple connection points refer to the intersection points of the axes of the multiple channels 13 and the deformable diaphragm 21, that is, the position where the diaphragm deforms remains unchanged, thereby avoiding the problem of different measurement values caused by the external pressure F acting on different points of application.

[0080] Embodiment III

[0081] Please refer to Figure 8 and Figure 9 , this embodiment provides a thin-film micro pressure sensor, including a sensor body 1, and a pair of diaphragms and a force conduction unit provided on the sensor body 1. The following description is made with reference to the orientation of Figure 8 .

[0082] The difference between the thin-film micro pressure sensor of this embodiment and that of Embodiment I is that:

[0083] The bottom wall 14 of the inner cavity 11 is a flexible wall, that is, the bottom wall 14 can deform in the normal direction.

[0084] The deformable diaphragm 21 is attached to the bottom wall 14 of the inner cavity 11 and can deform therewith; the non-deformable diaphragm 22 is attached to the top wall 16 of the inner cavity 11. QTC materials and detection electrodes 50 are respectively provided on the two diaphragms. Specifically, in this embodiment, the deformable diaphragm 21 is coated with QTC materials, and the detection electrodes 50 are provided on the non-deformable diaphragm 22. The setting of the detection electrodes 50 is the same as that in Embodiment I and will not be described herein again.

[0085] The top wall 16 of the inner cavity 11 is provided as a downwardly convex arc, so that the two diaphragms are in a mutually pressed position in the initial state.

[0086] The other structural settings of this embodiment are the same as those in Embodiment I.

[0087] The working principle and process of this embodiment are described as follows:

[0088] Apply pressure F from top to bottom. The pressure F acts on the elastic membrane 15, causing the filling liquid to flow from the outer cavity 12 to the inner cavity 11. The volume of the outer cavity 12 decreases and the volume of the inner cavity 11 increases. The bottom wall 14 bulges downward under the push of the filling liquid, causing the bottom wall 14 to move away from the top wall 16. As a result, the two diaphragms move away from each other. During this process, the resistance value changes gradually. At equilibrium, the change in the resistance value can be measured.

[0089] It should be noted that the bottom wall 14 has a certain elastic strength to sufficiently support the gravity of the filling liquid. That is, in the absence of external force, the bottom wall 14 will not have obvious deformation.

[0090] Embodiment 4

[0091] Please refer to Figure 10 and Figure 11 , this embodiment provides a thin-film micro pressure sensor, including a sensor body 1, and two pairs of diaphragms and two force conduction units provided on the sensor body 1. The following description is based on Figure 10 the orientation of

[0092] Specifically, inner cavities 11, outer cavities 12 and channels 13 connecting the two are provided on both the left and right sides of the sensor body 1 of this embodiment. The settings on both sides are symmetric, and the setting of each side is the same as that of Embodiment 3.

[0093] As Figure 10 shown, the inner cavities 11 on the left and right sides share a bottom wall 14. The bottom wall 14 is a flexible wall and can be deformed in the left-right direction. Deformable diaphragms 21 are attached to both the left and right side surfaces of the bottom wall 14, and the QTC material is coated on the deformable diaphragms 21.

[0094] Non-deformable diaphragms 22 are attached to the top walls 16 of the left and right inner cavities 11, and detection electrodes 50, such as carbon rods 51, are provided on the non-deformable diaphragms 22.

[0095] Elastic membranes 15 are respectively provided at the openings of the left and right outer cavities 12, and the edges of the elastic membranes 15 are hermetically connected to the inner peripheral walls 121 of the corresponding outer cavities 12.

[0096] The closed cavities between the elastic membrane 15 and the deformable diaphragm 21 on the same side form the cavities 31 of the force conduction units on that side, and the cavities 31 are filled with filling liquid.

[0097] Since the bottom wall 14 is a flexible wall, the left and right cavities 31 of this embodiment can be deformed cooperatively.

[0098] Please refer to Figure 11, taking the application of pressure F on the left side as an example, the pressure F acts on the elastic membrane 15 on the left side, causing the filling liquid to flow from the outer cavity 12 to the inner cavity 11. The volume of the left outer cavity 12 decreases and the volume of the left inner cavity 11 increases. The bottom wall 14 bulges and deforms to the right, causing the bottom wall 14 to move away from the top wall 16 on the left - thus, the measured resistance value on the left gradually increases; at the same time, the right - bulging bottom wall 14 presses the inner cavity 11 on the right, causing the filling liquid to flow from the inner cavity 11 to the outer cavity 12 on the right. The volume of the right outer cavity 12 increases, and then pushes the elastic membrane 15 on the right to bulge and deform to the right. During this process, the bottom wall 14 and the top wall 16 on the right are in close contact with each other - thus, the measured resistance value on the right gradually decreases.

[0099] At equilibrium, the final change in the measured resistance value can be obtained. Assuming that the change in resistance measured on the left is ΔR1 and the change in resistance measured on the right is ΔR2, then the change in resistance measured by the entire sensor is ΔR1 + ΔR2. Compared with the case of only setting a pair of diaphragms, the thin - film micro - pressure sensor of this embodiment can obtain a measured value approximately twice as large, thereby improving the detection sensitivity of the sensor to a certain extent.

[0100] The situation of applying pressure F on the right side is the same as that on the left side, and will not be elaborated here.

[0101] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above - mentioned terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0102] Although the embodiments of the present invention have been shown and described above, it can be understood that the above - mentioned embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above - mentioned embodiments within the scope of the present invention.

Claims

1. A thin-film micro pressure sensor, characterized in that, it includes at least a pair of diaphragms arranged oppositely, and a QTC material and a detection electrode are respectively arranged on the opposite surfaces of the two diaphragms; one of the diaphragms is set to be deformable, and the other diaphragm is set to be non-deformable; the deformable diaphragm is also connected with a force conduction unit, and the force conduction unit includes a closed cavity and a filling liquid filled therein; the force conduction unit is used to receive an external pressing force and conduct the external force to the deformable diaphragm, so that the deformable diaphragm deforms with the connection point as the center, and further makes the two diaphragms close to or away from each other; it further includes a sensor body, and at least one side of the sensor body is provided with an inner cavity, an outer cavity and a channel connecting the two; the diaphragm is arranged in the inner cavity; the force conduction unit is arranged in the communicating cavity formed by the inner cavity, the channel and the outer cavity; the non-deformable diaphragm is attached to the bottom wall of the inner cavity, and the bottom wall is a rigid wall; the deformable diaphragm is suspended in the inner cavity, and the edge of the deformable diaphragm is hermetically connected with the inner side wall of the inner cavity; an elastic membrane is arranged at the opening of the outer cavity, and the edge of the elastic membrane is hermetically connected with the inner peripheral wall of the outer cavity; the closed cavity between the elastic membrane and the deformable diaphragm forms the cavity; the number of the channels is set to be multiple, and the multiple channels are symmetrically distributed around the central axis of the sensor body; the sensor body is provided with two pairs of the diaphragms and two of the force conduction units, and the inner cavity, the outer cavity and the channel connecting the two are arranged on both the left and right sides of the sensor body, and the inner cavities on both sides share a bottom wall.

2. The thin-film micro pressure sensor according to claim 1, characterized in that, the deformable diaphragm is attached to the bottom wall of the inner cavity, and the bottom wall is a flexible wall; the non-deformable diaphragm is attached to the top wall of the inner cavity, and the top wall is set to be an arc protruding towards the direction of the bottom wall; an elastic membrane is arranged at the opening of the outer cavity, and the edge of the elastic membrane is hermetically connected with the inner peripheral wall of the outer cavity; the closed cavity between the elastic membrane and the deformable diaphragm forms the cavity.

3. The thin-film micro pressure sensor according to any one of claims 1-2, characterized in that, the filling liquid is silicone oil, glycerol or any non-conductive liquid.

4. The thin-film micro pressure sensor according to any one of claims 1-2, characterized in that, the detection electrode includes a plurality of conductive rods arranged at intervals, and adjacent two of the conductive rods are respectively connected with a positive lead and a negative lead; all the conductive rods form a detection area.

5. The thin-film micro pressure sensor according to claim 4, characterized in that, the detection area is circular, rectangular or any geometric shape.

6. The thin-film micro pressure sensor according to claim 4, characterized in that, the conductive rod is a carbon rod.

7. The thin-film micro pressure sensor according to claim 1, characterized in that, the sensor body is flat, and the axis of the channel is perpendicular to the plane where the sensor body is located.

8. The thin-film micro pressure sensor according to claim 7, characterized in that, the number of the channels is set to one, and the channel is located on the central axis of the sensor body.

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