Large-area capacitive pressure sensor

Abstract

A large-area capacitive pressure sensor according to an embodiment of the present invention comprises: a first electrode layer including a plurality of electrodes; a second electrode layer including a plurality of electrodes; and a dielectric layer disposed between the first electrode layer and the second electrode layer, wherein each of the plurality of electrodes included in the first electrode layer and the second electrode layer may be honeycomb-shaped and arranged in rows while being electrically connected to one another.

Description

Large-area capacitive pressure sensor

[0001] The present invention relates to a large-area capacitive pressure sensor, and more specifically, to the structure of a large-area capacitive pressure sensor.

[0002] Pressure sensors are electronic devices that detect changes in pressure applied to the sensor, and they are classified into various types based on their diverse principles and structures. Examples include resistive pressure sensors, where the resistance of a material changes when pressure is applied; piezoelectric pressure sensors, which generate an electrical signal when a specific material receives pressure; capacitive pressure sensors, which utilize the principle that capacitance changes due to a change in the distance between two electrodes; inductive pressure sensors, which utilize changes in induction between a coil and a core; optical fiber pressure sensors, which utilize light interference caused by the deformation of an optical fiber; pressure diaphragm pressure sensors, which utilize the principle that a thin diaphragm deforms under pressure to generate an electrical signal; and vacuum pressure sensors, which measure pressure in a vacuum state.

[0003] These pressure sensors can be manufactured in large sizes and are utilized in medical, healthcare, smart home appliances, wearable devices, robots, artificial intelligence devices, sports, and rehabilitation. For pressure sensors manufactured in large sizes, while detecting the intensity of the pressure is important, the location where the pressure is generated is also important, so a pressure sensor capable of acquiring the precise location or a method for acquiring the precise location where the pressure is generated may be required.

[0004] The technical problem that the present invention aims to solve is to provide a large-area capacitive pressure sensor capable of acquiring the precise location where pressure is generated.

[0005] Furthermore, the technical problem that the present invention aims to solve is not limited to the purposes mentioned above, and other unmentioned purposes will be clearly understood by a person skilled in the art from the description below.

[0006] A large-area capacitive pressure sensor according to an embodiment of the present invention comprises a first electrode layer including a plurality of electrodes, a second electrode layer including a plurality of electrodes, and a dielectric layer disposed between the first electrode layer and the second electrode layer, wherein each of the plurality of electrodes included in the first electrode layer and the second electrode layer may be in the form of a honeycomb-shaped electrode arranged in a row and electrically connected.

[0007] In a large-area capacitive pressure sensor according to an embodiment of the present invention, the electrical connections of a plurality of electrodes included in the first electrode layer and a honeycomb-shaped electrode included in a plurality of electrodes included in the second electrode layer may have different directions.

[0008] In a large-area capacitive pressure sensor according to an embodiment of the present invention, a honeycomb-shaped electrode included in each of a plurality of electrodes included in the first electrode layer is electrically connected in a first direction, and a honeycomb-shaped electrode included in each of a plurality of electrodes included in the second electrode layer is electrically connected in a second direction, and the first direction and the second direction may be perpendicular.

[0009] In a large-area capacitive pressure sensor according to an embodiment of the present invention, the spacing between a plurality of electrodes included in the first electrode layer and the spacing between a plurality of electrodes included in the second electrode layer can be determined based on the area to which pressure is applied.

[0010] In a large-area capacitive pressure sensor according to an embodiment of the present invention, the spacing between a plurality of electrodes included in the first electrode layer and the spacing between a plurality of electrodes included in the second electrode layer can be determined based on the size of the honeycomb shape.

[0011] In a large-area capacitive pressure sensor according to an embodiment of the present invention, the spacing between a plurality of electrodes included in the first electrode layer and the spacing between a plurality of electrodes included in the second electrode layer may be the same as the thickness of the dielectric layer.

[0012] In a large-area capacitive pressure sensor according to an embodiment of the present invention, the spacing between the electrodes may be 1.5 to 2 mm.

[0013] In a large-area capacitive pressure sensor according to an embodiment of the present invention, one of the plurality of electrodes included in the first electrode layer and the plurality of electrodes included in the second electrode layer may have the honeycomb-shaped electrode arranged in a zigzag pattern.

[0014] In a large-area capacitive pressure sensor according to an embodiment of the present invention, the size of the honeycomb-shaped electrode can be determined based on the spacing between the electrodes.

[0015] In a large-area capacitive pressure sensor according to an embodiment of the present invention, the size of the honeycomb-shaped electrode can be determined based on the area to which pressure is applied.

[0016] According to the present invention, a large-area capacitive pressure sensor capable of obtaining the exact location where pressure is generated can be provided.

[0017] In addition to these, the effects obtainable from the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

[0018] Figure 1 is a diagram illustrating a capacitive pressure sensor.

[0019] Figure 2 shows an exploded perspective view of a large-area capacitive pressure sensor as an example.

[0020] Figure 3 shows a plan view of the large-area capacitive pressure sensor of Figure 2.

[0021] FIGS. 4a to 4c are drawings showing various types of pressure applied to the large-area capacitive pressure sensor of FIG. 2.

[0022] FIGS. 5a to 5d are drawings showing electrodes disposed on the upper and lower portions of a dielectric layer in a large-area capacitive pressure sensor according to various embodiments of the present invention.

[0023] FIG. 6 is an exploded perspective view of a large-area capacitive pressure sensor according to one embodiment of the present invention.

[0024] FIGS. 7a and 7b are drawings for explaining the structure of a cell in a large-area capacitive pressure sensor according to one embodiment of the present invention.

[0025] FIGS. 8a to 8c are drawings showing various types of pressure applied to a large-area capacitive pressure sensor according to an embodiment of the present invention.

[0026] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0027] However, the technical concept of the present invention is not limited to some of the described embodiments but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more of the components among the embodiments may be selectively combined or substituted.

[0028] In addition, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a sense that is generally understood by those skilled in the art to which the present invention belongs, unless explicitly and specifically defined otherwise. Terms that are commonly used, such as terms defined in advance, may be interpreted in consideration of their meaning in the context of the relevant technology.

[0029] Furthermore, the terms used in the embodiments of the present invention are for the purpose of describing the embodiments and are not intended to limit the present invention.

[0030] In this specification, the singular form may include the plural form unless specifically stated otherwise in the text, and when described as "at least one of A and B and C (or more than one)," it may include one or more of all combinations that can be formed from A, B, and C.

[0031] In addition, terms such as first, second, A, B, (a), (b), etc. may be used when describing the components of the embodiments of the present invention.

[0032] These terms are intended merely to distinguish a component from other components and are not limited by the nature, order, sequence, etc., of the said component.

[0033] And, where it is stated that a component is 'connected', 'combined', or 'joined' to another component, this may include not only cases where the component is directly connected, combined, or joined to the other component, but also cases where it is 'connected', 'combined', or 'joined' due to another component located between the component and the other component.

[0034] Furthermore, when described as being formed or placed "above or below" each component, "above" or "below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, when expressed as "above or below," it may include the meaning of a downward direction as well as an upward direction relative to a single component.

[0035] Figure 1 is a diagram illustrating a capacitive pressure sensor.

[0036] Referring to FIG. 1, a capacitive pressure sensor (100) may include a first electrode (110), a second electrode (120), and a dielectric layer (130) disposed between the first electrode (110) and the second electrode (120). When pressure is applied between the first electrode (110) and the second electrode (120), the capacitance changes as the thickness of the dielectric layer (130) changes. The capacitive pressure sensor (100) can measure the applied pressure by checking the capacitance.

[0037] Specifically, capacitance can be calculated using [Equation 1].

[0038] [Mathematical Formula 1]

[0039]

[0040] Here, C is capacitance, A is the cross-sectional area of ​​the first electrode (110) and / or the second electrode (120), d is the distance between the first electrode (110) and the second electrode (120), and ε is the permittivity of the dielectric. According to [Equation 1], if the pressure applied between the first electrode (110) and the second electrode (120) increases and the distance between the first electrode (110) and the second electrode (120) narrows, the capacitance increases, and if the pressure decreases and the distance between the first electrode (110) and the second electrode (120) widens, the capacitance decreases. The applied pressure can be verified using the magnitude of the measured capacitance. The capacitive pressure sensor (100) is used to measure pressure over a wide area as well as pressure over a narrow area. Here, a large-area capacitive pressure sensor, that is, a large-area capacitive pressure sensor, may refer to a pressure sensor capable of obtaining the location where pressure is applied.

[0041] Figure 2 shows an exploded perspective view of a large-area capacitive pressure sensor as an example, and Figure 3 shows a plan view of the large-area capacitive pressure sensor of Figure 2.

[0042] Referring to FIG. 2, the large-area capacitive pressure sensor (200) may include a first electrode layer (210), a dielectric layer (220), and a second electrode layer (230). In addition, a contact member for contacting the electrode and the dielectric layer, a circuit for measuring capacitance through the electrode, etc. may be further included, but since this is not the gist of the present invention, a description thereof is omitted.

[0043] According to one embodiment, the large-area capacitive pressure sensor (200) may have a structure in which a first electrode layer (210), a dielectric layer (220), and a second electrode layer (230) are stacked, and the lower surface of the first electrode layer (210) may be in contact with the upper surface of the dielectric layer (220), and the lower surface of the dielectric layer (220) may be in contact with the upper surface of the second electrode layer (230).

[0044] According to one embodiment, the first electrode layer (210) and the second electrode layer (230) may include a plurality of electrodes. The plurality of electrodes may be in the shape of thin rods. The arrangement of the plurality of electrodes included in the first electrode layer (210) and the plurality of electrodes included in the second electrode layer (230) may differ from one another. For example, the plurality of electrodes may be arranged in a horizontal direction in the first electrode layer (210), and the plurality of electrodes may be arranged in a vertical direction in the second electrode layer (230). The number of the plurality of electrodes included in the first electrode layer (210) and the number of the plurality of electrodes included in the second electrode layer (230) may be the same, but may also differ. In the large-area capacitive pressure sensor (200) configured in this way, pressure can be measured only at positions where the plurality of electrodes of the first electrode layer (210) and the plurality of electrodes of the second electrode layer (230) correspond to each other. According to one embodiment, only the portion where the electrode is placed on both the upper and lower surfaces of the dielectric layer (220) can be referred to as a cell.

[0045] Hereinafter, a method for measuring pressure and obtaining the location where pressure is applied using the large-area capacitive pressure sensor of FIG. 2 is described. Specifically, FIG. 3 shows a plan view of the large-area capacitive pressure sensor of FIG. 2. In FIG. 3, the part indicated by a solid line represents the first electrode layer (210), and the part indicated by a dotted line represents the second electrode layer (230). Referring to FIG. 3, the first electrode layer (210) includes four rod electrodes (Y1, Y2, Y3, Y4), and the second electrode layer (230) also includes four rod electrodes (X1, X2, X3, X4). As previously explained, the parts capable of measuring pressure in the capacitive pressure sensor (200), i.e., the cells, can be a total of 16.

[0046] For example, when pressure is applied to cell A, it can be determined that pressure has been applied because only the capacitance measured by the first rod electrode (Y1) among the four rod electrodes included in the first electrode layer (210) and the second rod electrode (X2) among the four rod electrodes included in the second electrode layer (230) is different from the capacitance measured by the other rod electrodes. Additionally, the intensity of the applied pressure can be measured based on the measured capacitance value. If pressure is applied to cell B, it can be determined that pressure has been applied because only the capacitance measured by the second electrode (Y2) among the four rod electrodes included in the first electrode layer (210) and the fourth rod electrode (X4) among the four rod electrodes included in the second electrode layer (230) is different from the capacitance measured by the other rod electrodes. Likewise, the intensity of the applied pressure can be measured based on the measured capacitance value. According to one embodiment, pressure may be applied to the center of the cell, but may not be, making it difficult to determine the exact location where the pressure is applied.

[0047] FIGS. 4a to 4c are drawings showing various types of pressure applied to the large-area capacitive pressure sensor of FIG. 2.

[0048] Referring to FIG. 4a, the pressure-applied portion (410) may be between cell (411) and cell (413). Specifically, the pressure-applied portion (410) may be rotated 90 degrees from the center of cell (411) and located at a distance of half the diameter of the cell. In FIG. 4a, pressure may be applied evenly to both cells (411, 413), so that the capacitance may change in both cells (411, 413). In this case, the location where pressure is applied can be determined based on the location of the cell where the capacitance has changed.

[0049] Referring to FIG. 4b and FIG. 4c, the pressure applied portion (420, 430) may be between three cells (421, 423, 425, 431, 433, 435). Specifically, in FIG. 4b, the pressure is applied at a location rotated 45 degrees from the center of cell (421) and at a distance of half the diameter of the cell, and in FIG. 4c, the pressure is applied at a location rotated -45 degrees from the center of cell (431) and at a distance of half the diameter of the cell. Since the pressure applied portion (420, 430) in both FIG. 4b and FIG. 4c is at the corner of one cell, sufficient pressure is applied to one cell (421, 431), but sufficient pressure may not be applied to the other two cells (423, 425) (433, 435). This is due to the shape of the cell; while the capacitance value in a cell to which sufficient pressure is applied is sufficient to determine that pressure has been applied, the capacitance values ​​in other cells may not be sufficient to determine whether pressure has been applied or if it is noise, making it difficult to determine the exact location where pressure has been applied.

[0050] FIGS. 5a to 5d are drawings showing electrodes disposed on the upper and lower portions of a dielectric layer in a large-area capacitive pressure sensor according to various embodiments of the present invention.

[0051] Referring to FIGS. 5a through 5d, the shape of one electrode, i.e., a cell, placed on the upper and lower portions of the dielectric layer may be honeycomb or hexagonal. FIGS. 5a and 5b may constitute a single large-area capacitive pressure sensor, and FIGS. 5c and 5d may constitute a single large-area capacitive pressure sensor. Here, it may not be important where the electrode is located on the upper or lower portion of the dielectric layer.

[0052] According to one embodiment, the electrodes constituting the first electrode layer may be connected in a vertical direction as shown in FIG. 5a, and the electrodes constituting the second electrode layer may be connected in a horizontal direction as shown in FIG. 5b. Alternatively, the electrodes constituting the first electrode layer may be connected in a vertical direction as shown in FIG. 5b, and the electrodes constituting the second electrode layer may be connected in a horizontal direction as shown in FIG. 5a. Alternatively, the electrodes constituting the first electrode layer may be connected in a horizontal direction as shown in FIG. 5c, and the electrodes constituting the second electrode layer may be connected in a vertical direction as shown in FIG. 5d. Alternatively, the electrodes constituting the first electrode layer may be connected in a horizontal direction as shown in FIG. 5d, and the electrodes constituting the second electrode layer may be connected in a vertical direction as shown in FIG. 5c.

[0053] According to one embodiment, in order to more accurately measure the location where pressure is applied, the honeycomb-shaped cells included in either the first electrode layer or the second electrode layer may be arranged in an alternating or zigzag pattern. In FIG. 5a and FIG. 5b, the cells of FIG. 5b may be arranged in a zigzag pattern, and in FIG. 5c and FIG. 5d, the cells of FIG. 5d may be arranged in a zigzag pattern. When the shape of the cells is honeycomb and the cells are arranged in a zigzag pattern, the location where pressure is applied can be measured more accurately.

[0054] FIG. 6 is an exploded perspective view of a large-area capacitive pressure sensor according to one embodiment of the present invention.

[0055] Similar to FIG. 2, a large-area capacitive pressure sensor (600) according to one embodiment of the present invention may also include a first electrode layer (610), a dielectric layer (620), and a second electrode layer (630). The first electrode layer (610), the dielectric layer (620), and the second electrode layer (630) may be stacked so that the lower surface of the first electrode layer (610) may come into contact with the upper surface of the dielectric layer (620), and the lower surface of the dielectric layer (620) may come into contact with the upper surface of the second electrode layer (630).

[0056] The first electrode layer (610) and the second electrode layer (630) may include a plurality of electrodes. The electrodes included in the first electrode layer (610) and the second electrode layer (630) may be the same as any one of FIGS. 5a to 5d. That is, the first electrode layer (610) may include the electrode described in FIG. 5a, and the second electrode layer (630) may include the electrode described in FIG. 5b. Alternatively, the first electrode layer (610) may include the electrode described in FIG. 5b, and the second electrode layer (630) may include the electrode described in FIG. 5a. Alternatively, the first electrode layer (610) may include the electrode described in FIG. 5c, and the second electrode layer (630) may include the electrode described in FIG. 5d. Alternatively, the first electrode layer (610) may include the electrode described in FIG. 5d, and the second electrode layer (630) may include the electrode described in FIG. 5c.

[0057] In FIG. 2, the electrodes included in the first electrode layer and the second electrode layer were in the shape of thin rods, but in FIG. 5, electrodes with honeycomb shapes connected in a row may be included. The honeycomb-shaped electrodes included in the first electrode layer and the second electrode layer may have the same size and shape. In addition, the honeycomb-shaped electrodes included in the first electrode layer and the second electrode layer may be arranged to correspond to each other.

[0058] According to one embodiment, as shown in FIG. 6, the method for estimating the location where pressure is applied in a large-area capacitive pressure sensor according to one embodiment of the present invention may be the same or similar as described in FIG. 3. Each cell of the honeycomb shape may have coordinates, and by measuring the capacitance of each cell, the intensity of the pressure can be measured based on whether pressure is applied and the magnitude thereof. In addition, if the capacitance of a plurality of cells is different from that of other cells, the location where pressure is applied may be estimated to be the surrounding area rather than a specific cell.

[0059] FIGS. 7a and 7b are drawings for explaining the structure of a cell in a large-area capacitive pressure sensor according to one embodiment of the present invention.

[0060] Specifically, FIG. 7a shows a portion of the cross-sectional area of ​​a large-area capacitive pressure sensor. Referring to FIG. 7a, electrodes (720, 722) are disposed on the upper part of a dielectric layer (710), and electrodes (730, 732) are disposed on the lower part of the dielectric layer (710) to form a cell (740). The electrodes (720, 722) on the upper part of the dielectric layer can be connected left and right, and the electrodes (730, 732) on the lower part of the dielectric layer can be connected front and back. Alternatively, the electrodes (720, 722) on the upper part of the dielectric layer can be connected front and back, and the electrodes (730, 732) on the lower part of the dielectric layer can be connected left and right. The electrodes can be arranged at regular intervals. The spacing between electrodes, that is, between cells, can be constant. The spacing between cells can be determined based on the area that overlaps due to pressure. In addition, the spacing between cells can be determined based on the size of the cells. The size of the cell can also be determined based on the spacing between cells and / or the area overlapping due to pressure. Additionally, it may be determined by considering the streamlining of the pressure sensor. According to one embodiment, the distance between cells can be equal to or similar to the thickness of the dielectric layer (710). For example, as shown in FIG. 7b, if the thickness of the dielectric layer is 1.5 to 2 mm, the distance between cells can also be 1.5 to 2 mm. According to one embodiment, if the distance between cells (B) is 1.5 to 2 mm, the size of the cell, that is, the distance (A) between one side forming the cell and the corresponding side, can be 15.06 mm.

[0061] FIGS. 8a to 8c are drawings showing various types of pressure applied to a large-area capacitive pressure sensor according to an embodiment of the present invention.

[0062] Referring to FIG. 8a, the pressure-applied portion (810) may be between cell (811) and cell (813). Specifically, the pressure-applied portion (810) may be rotated 90 degrees from the center of cell (813) and located at a distance of half the diameter of the cell. In FIG. 8a, pressure may be applied evenly to both cells (811, 813), so that the capacitance may change in both cells (811, 813). In this case, the location where the pressure is applied can be determined based on the location of the cell where the capacitance has changed.

[0063] In FIG. 8b, the pressure applied portion (820) may be rotated 45 degrees from the center of the cell (823) and located at a distance of half the diameter of the cell. Referring to FIG. 8b, pressure may not be applied equally to the two cells (823, 825), but may be applied similarly.

[0064] Additionally, in FIG. 8c, the pressure may be rotated by -45 degrees from the center of the cell (831) and located at a distance of half the diameter of the cell. Referring to FIG. 8c, the pressure may not be applied equally to the two cells (831, 835), but may be applied similarly.

[0065] Compared to FIGS. 4a to 4c, the overlapping area is small at certain angles in FIGS. 4a to 4c, making it difficult to estimate the exact location where pressure is applied, whereas in FIGS. 8a to 8c, the overlapping area can be evenly overlapped at all angles, allowing for the estimation of the exact location where pressure is applied.

[0066] Although the invention has been described above with reference to embodiments, this is merely illustrative and does not limit the invention. Those skilled in the art will understand that various modifications and applications not exemplified above are possible within the scope of the essential characteristics of the embodiments. For example, each component specifically shown in the embodiments may be modified and implemented. Furthermore, differences related to such modifications and applications should be interpreted as being included within the scope of the invention as defined in the appended claims.

Claims

1. A first electrode layer comprising a plurality of electrodes; A second electrode layer comprising a plurality of electrodes; and It includes a dielectric layer disposed between the first electrode layer and the second electrode layer, and A large-area capacitive pressure sensor in which each of the plurality of electrodes included in the first electrode layer and the second electrode layer is in the form of honeycomb-shaped electrodes arranged in a row and electrically connected.

2. In Paragraph 1, A large-area capacitive pressure sensor in which the electrical connections of a plurality of electrodes included in the first electrode layer and a plurality of honeycomb-shaped electrodes included in the second electrode layer are oriented differently.

3. In Paragraph 2, The honeycomb-shaped electrodes included in each of the plurality of electrodes included in the first electrode layer are electrically connected in a first direction, and The honeycomb-shaped electrodes included in each of the plurality of electrodes included in the second electrode layer are electrically connected in a second direction, and A large-area capacitive pressure sensor in which the first direction and the second direction are perpendicular.

4. In Paragraph 1, A large-area capacitive pressure sensor in which the spacing between a plurality of electrodes included in the first electrode layer and the spacing between a plurality of electrodes included in the second electrode layer are determined based on the area to which pressure is applied.

5. In Paragraph 1, A large-area capacitive pressure sensor in which the spacing between a plurality of electrodes included in the first electrode layer and the spacing between a plurality of electrodes included in the second electrode layer are determined based on the size of the honeycomb shape.

6. In Paragraph 1, A large-area capacitive pressure sensor in which the spacing between a plurality of electrodes included in the first electrode layer and the spacing between a plurality of electrodes included in the second electrode layer are the same as the thickness of the dielectric layer.

7. In Paragraph 1, A large-area capacitive pressure sensor in which the spacing between the electrodes is 1.5 to 2 mm.

8. In Paragraph 1, A large-area capacitive pressure sensor in which a plurality of electrodes included in the first electrode layer and one of the plurality of electrodes included in the second electrode layer are arranged in a zigzag pattern, wherein the honeycomb-shaped electrodes are arranged in a zigzag pattern.

9. In Paragraph 1, A large-area capacitive pressure sensor in which the size of the above honeycomb-shaped electrode is determined based on the spacing between the electrodes.

10. In Paragraph 1, A large-area capacitive pressure sensor in which the size of the above honeycomb-shaped electrode is determined based on the area to which pressure is applied.

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