Piezoelectric sensor
By employing a piezoelectric layer and spiderweb-like electrode contact structure between the first and second circuit boards in the piezoelectric sensor, the problem of low sensitivity of the piezoelectric sensor is solved, and higher accuracy of electrical signals is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TIANJIN UNIV
- Filing Date
- 2024-10-28
- Publication Date
- 2026-04-28
AI Technical Summary
Existing piezoelectric sensors have low sensitivity, resulting in low accuracy of the measured electrical signals.
A piezoelectric layer is provided between the first circuit board and the second circuit board. The two sides are in contact with the first electrode and the second electrode, which are in a spider web shape, respectively. When the piezoelectric layer is compressed, positive and negative charges are generated on both sides. The spider web-shaped electrode absorbs the charge to improve the sensitivity.
The spiderweb-like electrode structure allows for a tighter wrapping of the piezoelectric layer, absorbing more charge and improving the sensitivity and accuracy of the electrical signal of the piezoelectric sensor.
Smart Images
Figure CN121933160A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of sensor technology, and more particularly to a piezoelectric sensor. Background Technology
[0002] With the rapid development of technology, technicians can use various methods to collect and analyze data. In cases where the target data cannot be obtained directly, it can be collected through sensors. Among them, piezoelectric sensors can convert pressure signals into electrical signals, and then further analyze and process the electrical signals to determine the magnitude of the pressure. However, in the existing technology, the sensitivity of piezoelectric sensors is low, which leads to low accuracy of the measured electrical signals. Summary of the Invention
[0003] In view of this, embodiments of this application provide a piezoelectric sensor with high sensitivity, which facilitates improving the accuracy of the measured electrical signal.
[0004] This application provides a piezoelectric sensor, comprising: a first circuit board with a spiderweb-shaped first electrode on one surface; a first signal output terminal connected to the first electrode; a second circuit board with a spiderweb-shaped second electrode on one surface; a second signal output terminal; the second circuit board being parallel to the first circuit board, with the surface of the second circuit board having the second electrode opposite to the surface of the first circuit board having the first electrode; and a piezoelectric layer disposed between the first and second circuit boards and in contact with both the first and second electrodes. When the piezoelectric layer is subjected to pressure, a positive charge is generated on the side of the piezoelectric layer near the first electrode, and a negative charge is generated on the side of the piezoelectric layer near the second electrode. The spiderweb-shaped first electrode absorbs a positive charge greater than a preset value, and the spiderweb-shaped second electrode absorbs a negative charge greater than the preset value, thereby improving the sensitivity of the piezoelectric sensor.
[0005] According to a specific implementation of an embodiment of this application, the first electrode includes a plurality of annular structures nested and spaced apart, and a first connecting portion; the plurality of annular structures are connected sequentially from the inside to the outside through the first connecting portion; the first connecting portion is connected to the first signal output terminal; the second electrode includes a plurality of annular structures nested and spaced apart, and a second connecting portion; the plurality of annular structures are connected sequentially from the inside to the outside through the second connecting portion; the second connecting portion is connected to the second signal output terminal.
[0006] According to one specific implementation of this application, the number of annular structures in the first electrode is equal to the number of annular structures in the second electrode.
[0007] According to a specific implementation of an embodiment of this application, the projection of the i-th ring structure in the first electrode onto the second circuit board is located in the region between the i-th ring structure and the (i-1)-th ring structure in the second electrode; wherein i is an integer, and is greater than or equal to 2 and less than or equal to the total number n of ring structures in the first electrode.
[0008] According to a specific implementation of an embodiment of this application, the centers of the plurality of annular structures in the first electrode are at the same position on the first circuit board; and / or, the centers of the plurality of annular structures in the second electrode are at the same position on the second circuit board.
[0009] According to a specific implementation of an embodiment of this application, the distance between any two adjacent ring structures in the plurality of ring structures in the first electrode is equal; and / or, the distance between any two adjacent ring structures in the plurality of ring structures in the second electrode is equal.
[0010] According to a specific implementation of an embodiment of this application, the first connecting part includes a plurality of straight line segments, each of the plurality of straight line segments being connected to each of the ring structures; and / or, the second connecting part includes a plurality of straight line segments, each of the plurality of straight line segments being connected to each of the ring structures.
[0011] According to a specific implementation of an embodiment of this application, the first connecting portion includes eight straight line segments, which are evenly distributed along the circumference of the annular structure; and / or, the second connecting portion includes eight straight line segments, which are evenly distributed along the circumference of the annular structure.
[0012] According to a specific implementation of an embodiment of this application, the first electrode further includes a third connecting portion, which is located outside the plurality of annular structures and connected to at least a portion of the plurality of straight line segments; the third connecting portion is also connected to the first signal output terminal; and / or, the second electrode further includes a fourth connecting portion, which is located outside the plurality of annular structures and connected to at least a portion of the plurality of straight line segments; the fourth connecting portion is also connected to the second signal output terminal.
[0013] According to a specific implementation of an embodiment of this application, the material of the first circuit board is a flexible material or a rigid material, the material of the second circuit board is a flexible material or a rigid material; and / or, the material of the piezoelectric layer is a flexible material or a rigid material.
[0014] In this embodiment of the piezoelectric sensor, a first circuit board has a first electrode arranged in a spiderweb pattern on one surface, and a first signal output terminal connected to the first electrode. A second circuit board has a second electrode arranged in a spiderweb pattern on one surface, and a second signal output terminal also provided. The second circuit board is arranged parallel to the first circuit board, and the surface of the second circuit board with the second electrode is opposite to the surface of the first circuit board with the first electrode. A piezoelectric layer is disposed between the first and second circuit boards and is in contact with the first and second electrodes, respectively. When the piezoelectric layer is subjected to pressure, a positive charge is generated on the side of the piezoelectric layer near the first electrode, and a negative charge is generated on the side of the piezoelectric layer near the second electrode. The spiderweb-shaped first and second electrodes can more tightly wrap the piezoelectric layer. In this way, the first electrode absorbs a positive charge greater than a preset value, and the spiderweb-shaped second electrode absorbs a negative charge greater than the preset value. That is, the first and second electrodes can absorb more charge, thereby facilitating the acquisition of a larger electrical signal and improving the sensitivity of the piezoelectric sensor. Attached Figure Description
[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 This is a schematic diagram of the structure of a piezoelectric sensor provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of the first electrode provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of the second electrode provided in one embodiment of this application; Figure 4 This is a schematic diagram showing the relative positional relationship between the first electrode and the second electrode in this embodiment; Figure 5 This is a comparison chart of the measurement results of the piezoelectric sensor with interlaced electrodes and the measurement results of the piezoelectric sensor with parallel electrodes in this embodiment. Figure 6 This is a comparison chart of the measurement results of the piezoelectric sensor in this embodiment with the measurement results of piezoelectric sensors with electrodes of other shapes. Detailed Implementation
[0017] The embodiments of this application will now be described in detail with reference to the accompanying drawings. It should be understood that the described embodiments are merely some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this 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. Therefore, they should not be construed as limitations on this invention.
[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.
[0020] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0021] To enable those skilled in the art to better understand the technical concept, implementation scheme and beneficial effects of the embodiments of this application, detailed descriptions are provided below through specific embodiments.
[0022] Figure 1 This is a schematic diagram of the structure of a piezoelectric sensor provided in one embodiment of this application. Figure 2 This is a schematic diagram of the structure of the first electrode provided in an embodiment of this application. Figure 3 This is a schematic diagram of the structure of the second electrode provided in one embodiment of this application, as shown below. Figures 1-3 As shown, the piezoelectric sensor in this embodiment may include: a first circuit board 1, a second circuit board 2, and a piezoelectric layer 3.
[0023] A first circuit board 1 has a first electrode 4 in a spider web pattern on one surface; the first circuit board 1 also has a first signal output terminal, and the first electrode 4 is connected to the first signal output terminal; a second circuit board 2 has a second electrode 5 in a spider web pattern on one surface; the second circuit board 2 also has a second signal output terminal, the second circuit board 2 is arranged parallel to the first circuit board 1, and the surface of the second circuit board 2 with the second electrode 5 is arranged opposite to the surface of the first circuit board 1 with the first electrode 4; a piezoelectric layer 3 is disposed between the first circuit board 1 and the second circuit board 2, and is in contact with the first electrode 4 and the second electrode 5 respectively.
[0024] When the piezoelectric layer 3 is subjected to pressure, a positive charge is generated on the side of the piezoelectric layer 3 near the first electrode 4, and a negative charge is generated on the side of the piezoelectric layer 3 near the second electrode 5. The spider web-shaped first electrode 4 absorbs a positive charge greater than a preset value, and the spider web-shaped second electrode 5 absorbs a negative charge greater than the preset value, thereby improving the sensitivity of the piezoelectric sensor.
[0025] In this embodiment, the material of the first circuit board 1 can be a rigid material or a flexible material. The material of the second circuit board 2 can be a rigid material or a flexible material.
[0026] When the material of the first circuit board 1 is a flexible material, the first circuit board 1 is a flexible printed circuit (FPC). Similarly, when the material of the second circuit board 2 is a flexible material, the second circuit board 2 is a flexible printed circuit (FPC).
[0027] The first electrode 4 and the second electrode 5 can be made of metallic materials, specifically, precious metals such as gold or silver. The materials of the first electrode 4 and the second electrode 5 can be the same or different.
[0028] The spiderweb-shaped first electrode 4 and second electrode 5 in this embodiment exhibit excellent ductility compared to electrode structures such as square bricks, honeycomb, circles, and thin sheets.
[0029] The piezoelectric layer 3 is made of piezoelectric material. When subjected to force, positive and negative charges will be generated on both sides of the piezoelectric layer 3. The positive charge can be transmitted to the subsequent signal processing module through the first electrode 4 and the negative charge through the second electrode 5.
[0030] In some cases, the piezoelectric material of the piezoelectric layer 3 can be either a rigid material or a flexible material.
[0031] With the first circuit board 1, the second circuit board 2, and the piezoelectric layer 3 all made of flexible materials, the piezoelectric sensor in this embodiment possesses overall softness and flexibility. In practical applications, the piezoelectric sensor of this embodiment can be placed above a human artery to sense physiological signals. For example, it is comfortable to wear on the skin surface. When subjected to pulse pressure, this sensor, made of flexible material, can undergo slight deformation with the skin's pulsation, thereby sensing the pulse signal in the piezoelectric layer 3.
[0032] The piezoelectric material of the piezoelectric layer 3 can be lead zirconate titanate film (PZT), polyvinylidene fluoride (PVDF), or hydrogel, etc.
[0033] In a specific example, the first electrode 4 and the second electrode 5 are arranged opposite to each other, and the first electrode 4 and the second electrode 5 are in complete contact with the piezoelectric layer 3, that is, the piezoelectric layer 3 completely covers the first electrode 4 and the second electrode 5.
[0034] The first signal output terminal on the first circuit board 1 and the second signal output terminal on the second circuit board 2 can be rectangular, square, triangular, cylindrical, or other shapes. The electrical signals from the first electrode 4 and the second electrode 5 can be transmitted to external devices through the first and second signal output terminals for further processing to obtain the pressure applied to the piezoelectric sensor.
[0035] In this embodiment, a spiderweb-shaped first electrode 4 is provided on one surface of the first circuit board 1, and a first signal output terminal is also provided on the first circuit board 1. The first electrode 4 is connected to the first signal output terminal. A spiderweb-shaped second electrode 5 is provided on one surface of the second circuit board 2, and a second signal output terminal is also provided on the second circuit board 2. The second circuit board 2 is arranged parallel to the first circuit board 1, and the surface of the second circuit board 2 with the second electrode 5 is arranged opposite to the surface of the first circuit board 1 with the first electrode 4. A piezoelectric layer 3 is disposed between the first circuit board 1 and the second circuit board 2, and is in contact with the first electrode 4 and the second electrode 5 respectively. When the piezoelectric layer 3 is subjected to pressure, a positive charge is generated on the side of the piezoelectric layer 3 near the first electrode 4, and a negative charge is generated on the side of the piezoelectric layer 3 near the second electrode 5. The spiderweb-shaped first electrode 4 and the second electrode 5 can more tightly wrap the piezoelectric layer 3. In this way, the first electrode 4 absorbs a positive charge greater than a preset value, and the spiderweb-shaped second electrode 5 absorbs a negative charge greater than the preset value. That is, the first electrode 4 and the second electrode 5 can absorb more charge, thereby facilitating the acquisition of a larger electrical signal and improving the sensitivity of the piezoelectric sensor.
[0036] In a specific example, the first electrode 4 includes multiple ring structures nested and spaced apart, and a first connecting portion 40; the multiple ring structures are connected sequentially from the inside to the outside through the first connecting portion 40; the first connecting portion 40 is connected to the first signal output terminal.
[0037] The second electrode 5 includes multiple ring structures nested in layers and spaced apart, and a second connecting part 50. The multiple ring structures are connected sequentially from the inside to the outside through the second connecting part 50. The second connecting part 50 is connected to the second signal output terminal.
[0038] The multiple annular structures of the first electrode 4 and the first connecting portion 40 may be made of a metallic material, specifically, a precious metal such as gold or silver. Similarly, the multiple annular structures of the second electrode 5 and the second connecting portion 50 may also be made of a metallic material, specifically, a precious metal such as gold or silver.
[0039] In this embodiment, in addition to improving the sensitivity of the piezoelectric sensor, the structure of the first electrode 4 and the structure of the second electrode 5 can save electrode materials and reduce the cost of the piezoelectric sensor.
[0040] The number of ring structures in the first electrode 4 may be different from or equal to the number of ring structures in the second electrode 5. In some examples, the number of ring structures in the first electrode 4 is equal to the number of ring structures in the second electrode 5.
[0041] See Figure 4 To further improve the sensitivity of the piezoelectric sensor, in some examples, the projection of the i-th ring structure in the first electrode 4 onto the second circuit board 2 is located in the region between the i-th ring structure and the (i-1)-th ring structure in the second electrode 5; where i is an integer, and is greater than or equal to 2 and less than or equal to the total number n of the ring structures in the first electrode 4.
[0042] The first ring structure in the first electrode 4 is the innermost ring structure among multiple nested ring structures, and the outermost ring structure is the nth ring structure, where n is the total number of ring structures in the first electrode 4.
[0043] The projection of the first annular structure of the first electrode 4 onto the second circuit board 2 is within the area enclosed by the first annular structure of the second electrode 5.
[0044] In this embodiment, the first electrode 4 and the second electrode 5 each have n rings, which are interleaved and staggered. The staggered structure not only increases the effective area of the electrode to sense the charge, but also, based on the differential principle, can effectively improve the sensing sensitivity.
[0045] See Figure 5Simulation experiments have shown that, compared to parallel electrodes, staggered electrodes can output a higher voltage under the same external force, thus proving the superiority of the staggered structure.
[0046] The multiple ring structures in the first electrode 4 can be eccentrically or concentrically arranged on the first circuit board 1. In some examples, the centers of the multiple ring structures in the first electrode 4 are in the same position on the first circuit board 1, that is, the multiple ring structures in the first electrode 4 are concentrically arranged.
[0047] Correspondingly, in some examples, the centers of the multiple ring structures in the second electrode 5 are located at the same position on the second circuit board 2.
[0048] It is understandable that the centers of the multiple ring structures in the first electrode 4 are in the same position on the first circuit board 1, and based on this, the centers of the multiple ring structures in the second electrode 5 are also in the same position on the second circuit board 2.
[0049] In the first electrode 4, multiple ring structures are arranged at intervals; the distance between any two adjacent ring structures can be equal or unequal. In some examples, the distance between any two adjacent ring structures in the first electrode 4 is equal. For example, the first electrode 4 includes three nested ring structures a1, a2, and a3, which are distributed sequentially from the inside out. The distance between a2 and a1 is equal to the distance between a3 and a2.
[0050] In the second electrode 5, multiple ring structures are arranged at intervals; the distance between each pair of adjacent ring structures can be equal or unequal. In some examples, the distance between each pair of adjacent ring structures in the second electrode 5 is equal. For example, the second electrode 5 includes three ring structures b1, b2 and b3 nested in layers, with b1, b2 and b3 distributed sequentially from the inside out, and the distance between b2 and b1 is equal to the distance between b3 and b2.
[0051] It is understandable that the distance between any two adjacent ring structures in the multiple ring structures of the first electrode 4 is equal, and based on this, the distance between any two adjacent ring structures in the multiple ring structures of the second electrode 5 is also equal.
[0052] The first connecting portion 40 can be a straight line or a curve; the first connecting portion 40 may include one straight line or multiple straight lines; the first connecting portion 40 may also include one curve or multiple curves. In some examples, the first connecting portion 40 includes multiple straight line segments, each of which is connected to a different ring structure. The number of multiple straight line segments can be two, three, five, nine, etc.
[0053] It is understood that the second connecting part 50 may also include multiple straight line segments, each of which is connected to a different annular structure. The number of straight line segments in the second connecting part 50 may be equal to or different from the number of straight line segments in the first connecting part 40.
[0054] It is understandable that if the first connecting part 40 includes multiple straight segments, and each of the multiple straight segments is connected to each of the ring structures, the second connecting part 50 may also include multiple straight segments, and each of the multiple straight segments is connected to each of the ring structures.
[0055] See Figure 2 In some examples, the first connecting portion 40 includes eight straight segments, which are evenly distributed circumferentially along the annular structure, making the first electrode 4 structure resemble a spider web. Spider web-shaped electrodes are biomimetic electrodes, a hot topic in the field of biosensing. In nature, spiders capture prey by weaving webs. To trap insects, the spider web must possess sufficient toughness and cushioning properties to prevent prey from breaking through and escaping. Research has found that spider web-shaped electrodes have many advantages. In this embodiment, the first electrode 4 can further improve the sensitivity of the piezoelectric sensor. See [link to relevant documentation]. Figure 6 Compared to hexagonal, square, and circular electrodes, the piezoelectric sensor with a spider web-shaped electrode has higher sensitivity. In addition, when the center of the spider web shape is impacted, each straight segment can disperse the impact force on the central area to the surrounding areas. Stress dispersion helps to improve the service life of the first electrode 4, which is of great significance, especially for micro sensors where the first electrode 4 has narrow and easily broken lines.
[0056] See Figure 3 Similar to the first connecting part 40, in some examples, the second connecting part 50 includes eight straight line segments, which are evenly distributed along the circumference of the ring structure.
[0057] It is understood that the first connecting part 40 includes a plurality of eight straight line segments, which are evenly distributed along the circumference of the ring structure, and the second connecting part 50 also includes a plurality of eight straight line segments, which are evenly distributed along the circumference of the ring structure.
[0058] In some examples, the first electrode 4 may also include a third connection portion located outside the plurality of annular structures and connected to at least a portion of the plurality of straight segments; the third connection portion is also connected to the first signal output terminal.
[0059] The shape of the third connecting part can be regular or irregular. In a specific example, the shape of the third connecting part can be a rectangle or a square.
[0060] In some other examples, the second electrode 5 also includes a fourth connection portion located outside the plurality of annular structures and connected to at least a portion of the plurality of straight line segments; the fourth connection portion is also connected to the second signal output terminal.
[0061] The shape of the fourth connecting part may be the same as or different from that of the third connecting part.
[0062] It is understood that the first electrode 4 also includes a third connecting part, which is located outside the plurality of annular structures and connected to at least a portion of the plurality of straight segments; the third connecting part is also connected to the first signal output terminal. In addition, the second electrode 5 also includes a fourth connecting part, which is located outside the plurality of annular structures and connected to at least a portion of the plurality of straight segments; the fourth connecting part is also connected to the second signal output terminal.
[0063] The technical solution of this application will be described below with reference to a specific embodiment.
[0064] See Figure 1 In this embodiment, the piezoelectric sensor body adopts a "sandwich structure" consisting of five layers. The outer layer is an FPC flexible circuit board with patterned electrodes, with the electrode surfaces facing each other, and a piezoelectric film sandwiched in the middle. The flexible circuit board can be made of polyimide or polyester film, the piezoelectric film can be made of materials such as PZT, PVDF, and hydrogel, and the electrode wires can be deposited using materials such as gold, silver, copper, nickel, and graphite.
[0065] The first circuit board 1, the second circuit board 2, and the piezoelectric layer 3 are of equal size and are arranged in relation to each other; the outer contour of the first electrode 4 is smaller than that of the first circuit board 1, the outer contour of the second electrode 5 is smaller than that of the first circuit board 1, the first electrode 4 and the second electrode 5 are directly opposite each other and in contact with the piezoelectric layer 3.
[0066] The sensor has an overall size of approximately 15 mm × 8 mm and a thickness of 1-2 mm; the electrode sensing area is approximately 6 mm × 6 mm, and a 2-3 mm square interface is reserved on the right side.
[0067] The first electrode 4 and the second electrode 5 are concentric rings in the shape of a spider web. The multi-layered ring structure of the first electrode 4 and the second electrode 5 specifically includes n layers (n ranges from 1 to 20). The width and spacing of the electrode lines (ring structure) range from 60 to 100 μm. In this way, the best balance between manufacturing process and sensing performance can be achieved.
[0068] The first electrode 4 and the second electrode 5 include radial lines (connecting lines) spaced 45° apart to relieve stress and fix the spider web. Specifically, the spider web structure of the first electrode 4 and the second electrode 5 adopts an interlaced arrangement design, with each layer of circular rings interlaced to form an interdigitated structure, such as... Figure 3 As shown.
[0069] The piezoelectric sensor in this embodiment not only improves the sensitivity of the piezoelectric sensor but also saves electrode material. The spiderweb structure of the first electrode 4 and the second electrode 5 adopts an alternating arrangement design, which not only increases the effective area of the electrode induced charge but also effectively improves the sensing sensitivity based on the differential principle. This piezoelectric sensor has broad application prospects. It can be used to measure minute deformations (stress, force sensitivity, etc.), such as pulse, as well as various physiological signals such as heartbeat and respiration. It is relatively easy to manufacture, readily mass-produce, and possesses strong commercial value.
[0070] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0071] The various embodiments in this specification are described in a related manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.
[0072] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A piezoelectric sensor, characterized in that, include: A first circuit board, one surface of which is provided with a first electrode in a spider web pattern; the first circuit board is also provided with a first signal output terminal, and the first electrode is connected to the first signal output terminal. The second circuit board has a second electrode in a spider web pattern on one surface; the second circuit board also has a second signal output terminal. The second circuit board is arranged parallel to the first circuit board, and the surface of the second circuit board with the second electrode is arranged opposite to the surface of the first circuit board with the first electrode. A piezoelectric layer is disposed between the first circuit board and the second circuit board, and is in contact with the first electrode and the second electrode, respectively; When the piezoelectric layer is subjected to pressure, a positive charge is generated on the side of the piezoelectric layer near the first electrode and a negative charge is generated on the side of the piezoelectric layer near the second electrode. The spider-web-shaped first electrode absorbs a positive charge greater than a preset value, and the spider-web-shaped second electrode absorbs a negative charge greater than the preset value, thereby improving the sensitivity of the piezoelectric sensor.
2. The piezoelectric sensor according to claim 1, characterized in that, The first electrode includes multiple ring structures nested and spaced apart, and a first connecting portion; the multiple ring structures are connected sequentially from the inside to the outside through the first connecting portion; the first connecting portion is connected to the first signal output terminal; The second electrode includes multiple ring structures nested together and spaced apart, and a second connecting portion. The multiple ring structures are connected sequentially from the inside to the outside through the second connecting portion; the second connecting portion is connected to the second signal output terminal.
3. The piezoelectric sensor according to claim 2, characterized in that, The number of annular structures in the first electrode is equal to the number of annular structures in the second electrode.
4. The piezoelectric sensor according to claim 3, characterized in that, The projection of the i-th ring structure in the first electrode onto the second circuit board is located in the region between the i-th ring structure and the (i-1)-th ring structure in the second electrode; where i is an integer, and is greater than or equal to 2 and less than or equal to the total number n of ring structures in the first electrode.
5. The piezoelectric sensor according to claim 2, characterized in that, The centers of the multiple ring structures in the first electrode are located at the same position on the first circuit board; and / or, the centers of the multiple ring structures in the second electrode are located at the same position on the second circuit board.
6. The piezoelectric sensor according to claim 5, characterized in that, In the first electrode, the distance between any two adjacent ring structures in the plurality of ring structures is equal; and / or, in the second electrode, the distance between any two adjacent ring structures in the plurality of ring structures is equal.
7. The piezoelectric sensor according to any one of claims 2-6, characterized in that, The first connecting portion includes multiple straight line segments, each of which is connected to a ring structure; and / or, the second connecting portion includes multiple straight line segments, each of which is connected to a ring structure.
8. The piezoelectric sensor according to claim 7, characterized in that, The first connecting portion includes eight straight line segments, which are evenly distributed along the circumference of the annular structure; and / or, the second connecting portion includes eight straight line segments, which are evenly distributed along the circumference of the annular structure.
9. The piezoelectric sensor according to claim 7, characterized in that, The first electrode further includes a third connection portion located outside the plurality of annular structures and connected to at least a portion of the plurality of straight line segments; the third connection portion is also connected to the first signal output terminal; and / or, the second electrode further includes a fourth connection portion located outside the plurality of annular structures and connected to at least a portion of the plurality of straight line segments; the fourth connection portion is also connected to the second signal output terminal.
10. The piezoelectric sensor according to claim 1, characterized in that, The first circuit board is made of a flexible or rigid material; the second circuit board is made of a flexible or rigid material; and / or the piezoelectric layer is made of a flexible or rigid material.