Pressure sensor

Abstract

A pressure sensor, according to an embodiment of the present invention, may comprise: a first electrode layer; a second electrode layer; a third electrode layer; a first elastic dielectric layer disposed between the first electrode layer and the second electrode layer; and a second elastic dielectric layer disposed between the second electrode layer and the third electrode layer.

Description

pressure sensor

[0001] The present invention relates to a pressure sensor, and more specifically, to a pressure sensor capable of sensing pressure in a vertical direction and pressure in a horizontal direction.

[0002] Various methods can be applied to sense pressure acting on a specific area. A commonly used method involves placing a first electrode and a second electrode, and an elastic dielectric between the first and second electrodes, in a specific area where pressure is to be sensed, and sensing the pressure through the change in the distance between the first and second electrodes caused by the pressure acting between them. For example, a surface pressure sensing device that senses pressure on a surface based on changes in the distance between the first and second electrodes can be placed on the surface of an object to sense pressure acting on a specific area of ​​the object.

[0003] Pressure sensors can be widely applied to various devices such as smart windows, displays, and mobile phones. Recently, pressure sensors are also being applied to robots, which are utilized in diverse fields including the medical and industrial sectors. For example, in industrial robots, pressure sensors are used as safety skins that detect collisions while absorbing the impact upon impact. However, these skins still lack the softness of skin, making them somewhat unsuitable for application to organs like the fingers of humanoid robots. Additionally, since pressure sensors currently only detect forces acting perpendicular to the surface, there is a problem in that they cannot fully achieve free directional capability.

[0004] The technical problem that the present invention aims to solve is to provide a pressure sensor capable of measuring the intensity of pressure in the vertical and horizontal directions.

[0005] In addition, the technical problem that the present invention aims to solve is to provide a pressure sensor capable of determining the direction in which pressure is applied.

[0006] In addition, the technical problem that the present invention aims to solve is to provide a pressure sensor capable of preventing errors in which pressures of unequal intensity are measured as equal depending on the direction in which pressure is applied.

[0007] In addition to this, the technical problems that the present invention aims to solve are not limited to those described above, and other technical problems may exist.

[0008] A pressure sensor according to an embodiment of the present invention may include a first electrode layer, a second electrode layer, a third electrode layer, a first elastic dielectric layer disposed between the first electrode layer and the second electrode layer, and a second elastic dielectric layer disposed between the second electrode layer and the third electrode layer.

[0009] In a pressure sensor according to an embodiment of the present invention, the first electrode layer includes a plurality of electrodes, and the plurality of electrodes may be arranged at a predetermined interval.

[0010] In a pressure sensor according to an embodiment of the present invention, the spacing between a plurality of electrodes included in the first electrode layer may be constant.

[0011] In the pressure sensor according to an embodiment of the present invention, the spacing between a plurality of electrodes included in the first electrode layer may not be constant.

[0012] In a pressure sensor according to an embodiment of the present invention, the second electrode layer and the third electrode layer may each include a plurality of electrodes.

[0013] In a pressure sensor according to an embodiment of the present invention, a plurality of electrodes included in the second electrode layer and a plurality of electrodes included in at least one electrode layer among a plurality of electrodes included in the third electrode layer can be arranged in a certain pattern.

[0014] In a pressure sensor according to an embodiment of the present invention, a plurality of electrodes included in the second electrode layer are spaced apart from each other along a second horizontal direction, a plurality of electrodes included in the third electrode layer are spaced apart from each other along a first horizontal direction, and the first horizontal direction and the second horizontal direction may be directions perpendicular to the thickness direction of the pressure sensor.

[0015] A pressure sensor according to an embodiment of the present invention further comprises at least one bonding layer, and the at least one bonding layer may be disposed in at least one of the following: between the first electrode layer and the first elastic dielectric layer, between the first elastic dielectric layer and the second electrode layer, between the second electrode layer and the second elastic dielectric layer, and between the second elastic dielectric layer and the third electrode layer.

[0016] In the pressure sensor according to an embodiment of the present invention, the first elastic dielectric layer and the second elastic dielectric layer may be composed of different elastic dielectrics.

[0017] According to an embodiment of the present invention, a pressure sensor capable of measuring the intensity of pressure in the vertical and horizontal directions can be provided.

[0018] According to an embodiment of the present invention, a pressure sensor capable of determining the direction in which pressure is applied can be provided.

[0019] 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.

[0020] FIG. 1 is a perspective view of a pressure sensor according to an embodiment of the present invention.

[0021] FIG. 2 is a plan view illustrating the sensing of a pressure sensor according to an embodiment of the present invention.

[0022] Figure 3 is a cross-sectional view illustrating the sensing in Figure 2.

[0023] FIG. 4 is a cross-sectional view illustrating the sensing of a pressure sensor when pressure is applied obliquely according to an embodiment of the present invention.

[0024] FIG. 5 is a perspective view of a pressure sensor according to one embodiment of the present invention.

[0025] FIG. 6 is an exploded perspective view of a pressure sensor according to one embodiment of the present invention.

[0026] FIGS. 7a and 7b are cross-sectional views illustrating pressure sensing when force is applied in a vertical direction and an oblique direction to a horizontal pressure sensor according to one embodiment of the present invention.

[0027] FIG. 8 is a drawing showing a robot with a pressure sensor applied according to an embodiment of the present invention.

[0028] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] In addition, terms such as first, second, A, B, (a), (b), etc. may be used to describe the components of the embodiments of the present invention.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] FIG. 1 is a perspective view of a pressure sensor according to an embodiment of the present invention, FIG. 2 is a plan view illustrating the sensing of a pressure sensor according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view illustrating the sensing in FIG. 2.

[0038] Referring to FIG. 1, the pressure sensor (100) may include a first electrode layer (110), an elastic dielectric layer (120), and a second electrode layer (130) that are sequentially stacked in the thickness direction. The elastic dielectric layer (120) may be located between the first electrode layer (110) and the second electrode layer (130).

[0039] The first electrode layer (110) may include a first electrode (110a). The first electrode (110a) may be disposed on one side of the elastic dielectric layer (120). The second electrode layer (130) may include a second electrode (130a). The second electrode (130a) may be disposed on the other side of the elastic dielectric layer (120). The first electrode (110a) and the second electrode (130a) may be arranged in a predetermined pattern. For example, the first electrode (110a) may be spaced apart from each other along a first horizontal direction and extend in a second horizontal direction. The second electrode (130a) may be spaced apart from each other along a second horizontal direction and extend in a first horizontal direction. The first horizontal direction and the second horizontal direction may be directions perpendicular to the thickness direction. Furthermore, one of the first electrode (110a) and the second electrode (130a) may not have a pattern.

[0040] According to one embodiment, pressure can be determined by the capacitance measured by one of a plurality of first electrodes (110a) and one of a plurality of second electrodes (130a). After measuring the capacitance for all possible cases in which the first electrode (110a) and the second electrode (130a) can be selected, the point corresponding to the first electrode (110a) and the second electrode (130a) having the largest capacitance may be the location where pressure is applied. Accordingly, the location where pressure is applied can be determined based on the arrangement in which the first electrode (110a) and the second electrode (130a) are placed on the elastic dielectric layer (120). The capacitance formed by the first electrode (110a) and the second electrode (130a) will be described later.

[0041] And a bonding layer (not shown) for attaching the first electrode layer (110) and the second electrode layer (130) to the elastic dielectric layer (120) may be additionally disposed in the first electrode layer (110) and the second electrode layer (130).

[0042] The first electrode (110a) and the second electrode (130a) may be made of, for example, conductive fibers. The conductive fibers may include metals such as silver (Ag), copper (Cu), and gold (Au). For example, the conductive fibers may have a structure in which a conductive material, such as metal, is coated onto a core made of ordinary fibers such as polyester, nylon, acrylic, polypropylene, polyurethane, cotton, silk, acetate, etc., or they may be yarns made solely of conductive materials. In addition, any electronic fiber material may be used as the conductive fiber. And the non-conductive fibers may be the ordinary fibers described above.

[0043] Additionally, the first electrode (110a) and the second electrode (130a) may be woven together with non-conductive fibers using conductive fibers. That is, the first electrode layer (110) may be a sheet woven in a form in which the first electrode (110a) and non-conductive fibers are woven together. Likewise, the second electrode layer (130) may be a sheet woven together with the second electrode (130a) and non-conductive fibers. In this case, since the first electrode (110a) and the second electrode (130a) have intersecting arrangement directions, if the first electrode (110a) is a warp in the first electrode layer (110), the second electrode (130a) may be a weft in the second electrode layer (130). Additionally, the first electrode layer (110) and the second electrode layer (130) may have a structure in which conductive fibers and non-conductive fibers are woven together in various ways, such as plain weave, twill weave, and satin weave.

[0044] As illustrated in FIG. 1, the elastic dielectric layer (120) may be located between the first electrode layer (110) and the second electrode layer (130). Thus, the first electrode (110a), the elastic dielectric layer (120), and the second electrode (130a) can be modeled as a capacitor.

[0045] A capacitor may include a dielectric between its top and bottom surfaces. When the area between the top and bottom surfaces is A, the distance between the top and bottom surfaces is L, and the permittivity of the dielectric is ε, the capacitance C of the capacitor is given by the following [Equation 1].

[0046] [Mathematical Formula 1]

[0047]

[0048] Referring to [Equation 1], capacitance is inversely proportional to the distance between the top and bottom surfaces when the permittivity and the area of ​​the top and bottom surfaces are constant.

[0049] However, the elastic dielectric layer (120) can be deformed when subjected to external force. When the elastic dielectric layer (120) is subjected to external force, the thickness of the elastic dielectric layer (120) located between the first electrode layer (110) and the second electrode layer (130) changes, and thus the capacitance between the first electrode layer (110) and the second electrode layer (130) changes. Depending on the change in capacitance, the signal transmitted by the first electrode layer (110) and the second electrode layer (130) may change.

[0050] For example, as illustrated in FIGS. 2 and 3, when pressure is applied to the pressure sensor (100) in the y direction (vertical direction), the thickness (a2) of the elastic dielectric layer (120) in the pressure-applied area becomes thinner than the thickness (a1) of the elastic dielectric layer (120) in the pressure-applied area. Accordingly, the capacitance of the elastic dielectric layer (120) in the pressure-applied area changes, allowing pressure to be detected.

[0051] The elastic dielectric layer (120) may be made of a dielectric material having elasticity and restoring force that allows the shape to be deformed when a contact force is applied from the outside and returns to the original shape when the contact force is released. The elastic dielectric layer (120) may include, for example, a fiber substrate having a random fiber arrangement such as a foam, nonwoven fabric, or nanoweb, a synthetic fiber or natural fiber including one selected from the group consisting of polyurethane, nylon, polyethylene terephthalate, and polyester, an elastomer, rubber, urethane, etc.

[0052] Additionally, the elastic dielectric layer (120) may include an elastic body and a conductive composite dispersed within the elastic body. Here, the elastic body may be a fiber substrate having a random fiber arrangement such as the aforementioned foam, nonwoven fabric, or nanoweb, a synthetic fiber or natural fiber including one selected from the group consisting of polyurethane, nylon, polyethylene terephthalate, and polyester, an elastomer, rubber, urethane, etc. The conductive composite may be coated on the surface of the fibers forming the elastic body or dispersed within the elastic body. Accordingly, the elastic dielectric layer (120) has insulating properties with a resistance of 1 kΩ or more in a normal state, but when a physical change occurs around the elastic dielectric layer (120), that is, when pressure is applied to the pressure sensor, the thickness of the elastic dielectric layer (120) decreases, and the resistance changes. By utilizing this phenomenon, pressure can be measured by the change in resistance.

[0053] The conductive composite may include a conductive polymer and a conductive powder. The conductive composite may be included in an amount of 1 to 10 wt% of the elastomer. If the conductive composite is included in an amount exceeding 10 wt% of the elastomer, it becomes difficult to guarantee insulation properties in the absence of applied pressure. The conductive polymer may include polyaniline or polypyrrole. Additionally, the conductive powder may include one selected from the group consisting of Au, Ag, Cu, Ni, CNT (Carbon Nano Tube), graphene, and ceramic fillers.

[0054] Additionally, the elastic dielectric layer (120) may include micropores. And the thickness of the elastic dielectric layer (120) may be less than a few mm.

[0055] FIG. 4 is a cross-sectional view illustrating the sensing of a pressure sensor when pressure is applied obliquely according to an embodiment of the present invention.

[0056] Referring to FIG. 4, pressure can be applied to the pressure sensor in an oblique direction (direction a). The pressure in the oblique direction (direction a) can consist of pressure in the vertical direction (direction y) and pressure in the horizontal direction (-x direction). As described above, the pressure sensor is modeled as a capacitor to sense pressure, and thus can sense pressure based on the distance between the electrode on the upper surface of the elastic dielectric layer and the electrode on the lower surface of the elastic dielectric layer, that is, the thickness of the elastic dielectric layer. The pressure sensor of FIG. 1 can sense pressure in the vertical direction, but may not be able to sense pressure in the horizontal direction. In this case, the pressure sensor measures the intensity of the pressure in the vertical direction rather than the actual intensity of the pressure. Therefore, even if pressure of substantially different intensity is applied, it may be measured as the same pressure depending on the direction in which the pressure is applied. Since such a pressure sensor cannot accurately determine the direction in which the pressure is applied and the intensity of the total pressure, the fields in which it can be applied may be limited.

[0057] Below, a pressure sensor capable of sensing horizontal pressure in addition to vertical pressure is described.

[0058] FIG. 5 is a perspective view of a pressure sensor according to one embodiment of the present invention, and FIG. 6 is an exploded perspective view of a pressure sensor according to one embodiment of the present invention.

[0059] Referring to FIG. 5, the pressure sensor (500) may include a first electrode layer (510), a first elastic dielectric layer (520), a second electrode layer (530), a second elastic dielectric layer (540), and a third electrode layer (550) that are sequentially stacked in the thickness direction. The first elastic dielectric layer (520) may be located between the first electrode layer (510) and the second electrode layer (530), and the second elastic dielectric layer (540) may be located between the second electrode layer (530) and the third electrode layer (550).

[0060] According to one embodiment, the pressure sensor (500) may include a horizontal pressure sensor (560) capable of measuring pressure in the horizontal direction and a vertical pressure sensor (570) capable of measuring pressure in the vertical direction. In FIG. 5, the horizontal pressure sensor (560) may include a first electrode layer (510) and a first elastic dielectric layer (520), and the vertical pressure sensor (570) may include a second electrode layer (530), a second elastic dielectric layer (540), and a third electrode layer (550). According to one embodiment, the pressure sensor (500) may measure pressure in the vertical direction using the vertical pressure sensor (570) and then measure pressure in the horizontal direction using the horizontal pressure sensor (560) based on the above.

[0061] The first electrode layer (510) may include a first electrode. The first electrode may be disposed on one side of the first elastic dielectric layer (520). A vertical pressure sensor (570) may be disposed on the other side of the first elastic dielectric layer (520). A second electrode layer (530) of the vertical pressure sensor (570) may be disposed on the other side of the first elastic dielectric layer (520). The first electrode may be arranged in a predetermined pattern. For example, the first electrode may be spaced apart from each other along the second horizontal direction and extend in the first horizontal direction. Alternatively, the first electrode may be spaced apart from each other along the first horizontal direction and extend in the second horizontal direction. The first horizontal direction and the second horizontal direction may be directions perpendicular to the thickness direction. The plurality of first electrodes may be spaced apart at equal intervals, but may not be. For example, the spacing between the plurality of first electrodes may vary depending on the location where the pressure sensor (500) is disposed. If the spacing between multiple first electrodes is narrow, it is difficult to sense high pressure, but the resilience is good, so the sensing speed can be fast. Also, it may vary depending on the dielectric constant of the first elastic dielectric layer (520). If the dielectric constant of the first elastic dielectric layer (520) is high, it is good for sensing high pressure, but the resilience is relatively poor, so the sensing speed may be slow.

[0062] The second electrode layer (530) may include a second electrode. The second electrode may be disposed on one side of the second elastic dielectric layer (540). And the third electrode layer (550) may include a third electrode. The third electrode may be disposed on the other side of the second elastic dielectric layer (540). The second electrode and the third electrode may be arranged in a predetermined pattern. For example, the second electrode may be spaced apart from each other along the second horizontal direction and extend in the first horizontal direction in multiple numbers. The third electrode may be spaced apart from each other along the first horizontal direction and extend in the second horizontal direction in multiple numbers. Furthermore, one of the second electrode and the third electrode may not have a pattern. According to one embodiment, the location where pressure is applied in the vertical direction can be determined based on the arrangement in which the second electrode and the third electrode are disposed on the second elastic dielectric layer (540).

[0063] According to one embodiment, a bonding layer is disposed between the first electrode layer (510) and the first elastic dielectric layer (520), between the first elastic dielectric layer (520) and the second electrode layer (530), between the second electrode layer (530) and the second elastic dielectric layer (540), and between the second elastic dielectric layer (540) and the third electrode layer (550) so as to bond them to each other.

[0064] A bonding layer (not shown) for attaching the first electrode layer (110) and the second electrode layer (130) to an elastic dielectric layer (120) may be additionally disposed in the first electrode layer (110) and the second electrode layer (130).

[0065] According to one embodiment, at least one of the first electrode, the second electrode, and the third electrode may be composed of, for example, a conductive fiber. The conductive fiber may include a metal such as silver (Ag), copper (Cu), or gold (Au). For example, the conductive fiber may have a structure in which a conductive material such as a metal is coated on a core made of a general fiber such as polyester, nylon, acrylic, polypropylene, polyurethane, cotton, silk, acetate, etc., or it may be a thread made solely of a conductive material. In addition, any electronic fiber material may be used as the conductive fiber. And the non-conductive fiber may be the general fiber described above.

[0066] Additionally, at least one of the first electrode, the second electrode, and the third electrode may be woven together with a non-conductive fiber using a conductive fiber. That is, the first electrode layer (510) may be a sheet woven in a form in which the first electrode and the non-conductive fiber are woven together. Likewise, the second electrode layer (530) may be a sheet woven together with the second electrode and the non-conductive fiber, and the third electrode layer (550) may be a sheet woven together with the third electrode and the non-conductive fiber. For example, the first electrode may be arranged in any direction, and the first electrode may be either a warp or a weft in the first electrode layer (510). Since the arrangement directions of the second electrode and the third electrode intersect each other, if the second electrode is a warp in the second electrode layer (530), the third electrode may be a weft in the third electrode layer (550). Additionally, the second electrode layer (530) and the third electrode layer (550) may have a structure in which conductive fibers and non-conductive fibers are woven together in various ways, such as plain weave, twill weave, and satin weave.

[0067] The first elastic dielectric layer (520) and the second elastic dielectric layer (540) can be deformed when subjected to external force. In the first elastic dielectric layer (520), the spacing between the plurality of first electrodes included in the first electrode layer (510) changes due to a horizontal force applied externally, thereby changing the capacitance between the plurality of first electrodes. This is explained in detail in FIGS. 7a and 7b.

[0068] The second elastic dielectric layer (540) causes the thickness of the elastic dielectric layer (120) located between the first electrode layer (110) and the second electrode layer (130) to change due to a vertical force applied from the outside, thereby changing the capacitance between the first electrode layer (110) and the second electrode layer (130). This may be the same or similar as described above in FIGS. 1 to 3.

[0069] The first elastic dielectric layer (520) and the second elastic dielectric layer (540) may be made of a dielectric material having elasticity and restoring force that allows the shape to be deformed when a contact force is applied from the outside and returns to the original shape when the contact force is released. The first elastic dielectric layer (520) and the second elastic dielectric layer (540) may include, for example, a fiber substrate having a random fiber arrangement such as a foam, nonwoven fabric, or nanoweb, a synthetic fiber or natural fiber including one selected from the group consisting of polyurethane, nylon, polyethylene terephthalate, and polyester, an elastomer, rubber, urethane, etc.

[0070] Additionally, the first elastic dielectric layer (520) and the second elastic dielectric layer (540) may include an elastomer and a conductive composite dispersed within the elastomer. Here, the elastomer may be a fiber substrate having a random fiber arrangement such as the aforementioned foam, nonwoven fabric, or nanoweb, a synthetic fiber or natural fiber including one selected from the group consisting of polyurethane, nylon, polyethylene terephthalate, and polyester, an elastomer, rubber, urethane, etc. The conductive composite may be coated on the surface of the fibers forming the elastomer or dispersed within the elastomer.

[0071] The conductive composite may include a conductive polymer and a conductive powder. The conductive composite may be included in an amount of 1 to 10 wt% of the elastomer. If the conductive composite is included in an amount exceeding 10 wt% of the elastomer, it becomes difficult to guarantee insulation properties in the absence of applied pressure. The conductive polymer may include polyaniline or polypyrrole. Additionally, the conductive powder may include one selected from the group consisting of Au, Ag, Cu, Ni, CNT (Carbon Nano Tube), graphene, and ceramic fillers.

[0072] Additionally, the elastic dielectric layer (120) may include micropores.

[0073] According to one embodiment, the first elastic dielectric layer (520) and the second elastic dielectric layer (540) may be composed of the same material, but are not limited thereto. For example, the first elastic dielectric layer (520) may be composed of nylon, and the second elastic dielectric layer (540) may be composed of polyurethane.

[0074] FIGS. 7A and 7B are cross-sectional views illustrating pressure sensing when force is applied in a vertical direction and an oblique direction to a horizontal pressure sensor according to one embodiment of the present invention.

[0075] Referring to FIGS. 7a and 7b, the first electrode layer may include a plurality of electrodes (511, 512, 513, 514, 515, 516). For example, the spacing between the plurality of electrodes (511, 512, 513, 514, 515, 516) may be constant, but is not limited thereto. For convenience of explanation, it may be assumed that the spacing between the plurality of electrodes (511, 512, 513, 514, 515, 516) shown in FIGS. 7a and 7b is constant.

[0076] To sense pressure in the horizontal direction, the capacitance between adjacent electrodes among a plurality of electrodes (511, 512, 513, 514, 515, 516) may need to be measured. The direction and intensity of the applied pressure can be sensed by using the change in capacitance measured before the pressure is applied and the capacitance measured after the pressure is applied. For example, the horizontal pressure may be applied in a direction where the capacitance measured after the pressure is applied becomes larger than the capacitance measured before the pressure is applied, relative to the point where the pressure is applied.

[0077] More specifically, FIGS. 7a and 7b illustrate cases where pressure is applied, for example, between the third electrode (513) and the fourth electrode (514), where FIG. 7a shows the case where pressure is applied in the vertical direction and FIG. 7b shows the case where pressure is applied in the horizontal direction.

[0078] As shown in FIG. 7a, when pressure (710) is applied in a vertical direction, the first electrode layer can be symmetrical. Due to the pressure (710) in the vertical direction, the third electrode (513) and the fourth electrode (514) are pressed, and the gap between the third electrode (513) and the fourth electrode (514) can be narrowed. Also, the gap between the second electrode (512) and the third electrode (513), and between the fourth electrode (514) and the fifth electrode (515) can be narrowed. However, the gap between the third electrode (513) and the fourth electrode (514), which is directly affected by the pressure, may be narrower than the gap between the second electrode (512) and the third electrode (513), and between the fourth electrode (514) and the fifth electrode (515). On the other hand, the space between the first electrode (511) and the second electrode (512), and between the fifth electrode (515) and the sixth electrode (516), which are not directly or indirectly affected by the pressure (710) in the vertical direction, may not change. Therefore, the space between the second electrode (512) and the third electrode (513), between the third electrode (513) and the fourth electrode (514), and between the fourth electrode (514) and the fifth electrode (515) may become narrower than before the pressure was applied, and the capacitance may increase, while the capacitance between the first electrode (511) and the second electrode (512) and the capacitance between the fifth electrode (515) and the sixth electrode (516) may not change. In other words, the capacitance may change symmetrically with respect to the location where the pressure is applied. In this case, the pressure may be determined to have been applied in the vertical direction.

[0079] As shown in FIG. 7b, when pressure (720) is applied in an oblique direction, the first electrode layer may be pushed in one direction. Due to the pressure (720) in an oblique direction, the third electrode (513) and the fourth electrode (514) may be pushed to the left. That is, due to the pressure (720) in an oblique direction, the distance between the first electrode (511) and the second electrode (512) and the distance between the second electrode (512) and the third electrode (513) may be narrowed, and the distance between the fourth electrode (514) and the fifth electrode (515) and the distance between the fifth electrode (515) and the sixth electrode (516) may be widened. Accordingly, the capacitance between the first electrode (511) and the second electrode (512), and the capacitance between the second electrode (512) and the third electrode (513), can be increased, and the capacitance between the fourth electrode (514) and the fifth electrode (515), and the capacitance between the fifth electrode (515) and the sixth electrode (516), can be decreased. Therefore, it can be determined that horizontal pressure has been applied in the direction in which the capacitance has increased relative to the location where pressure was applied.

[0080] According to the above description, the direction and intensity of the actual applied pressure can be predicted based on the pressure sensed by the horizontal pressure sensor and the pressure sensed by the vertical pressure sensor.

[0081] FIG. 8 is a drawing showing a robot with a pressure sensor applied according to an embodiment of the present invention.

[0082] A pressure sensor according to an embodiment of the present invention may be placed at various locations on a robot. For example, as shown in FIG. 8, the pressure sensor may be located on the outer surface of the robot (800). Additionally, the pressure sensor may be located on various parts of the robot (800), such as the chest (810), abdomen (820), legs (830), and hands (840), and may be arranged to surround the robot (800). With this configuration, the outer surface of the robot (800) can be easily protected by the pressure sensor. At the same time, the pressure sensor can detect the force applied to the outer surface of the robot (800). Furthermore, the pressure sensor may be electrically connected to the robot (800). Accordingly, a signal (e.g., pressure information) detected by the pressure sensor may be transmitted to the robot (800). Accordingly, the robot (800) may perform processing of the pressure information by a processor, a control unit, etc., mounted inside.

[0083] In addition to the above, the pressure sensor according to the embodiment of the present invention can be attached to various products. For example, the pressure sensor can be attached to a smart window, a display, a mobile phone, etc.

[0084] 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. First electrode layer; Second electrode layer; Third electrode layer: A first elastic dielectric layer disposed between the first electrode layer and the second electrode layer; and A pressure sensor comprising a second elastic dielectric layer disposed between the second electrode layer and the third electrode layer.

2. In Paragraph 1, The first electrode layer comprises a plurality of electrodes, and The above plurality of electrodes are pressure sensors arranged at fixed intervals.

3. In Paragraph 2, A pressure sensor in which the spacing between a plurality of electrodes included in the first electrode layer is constant.

4. In Paragraph 2, A pressure sensor in which the spacing between a plurality of electrodes included in the first electrode layer is not constant.

5. In Paragraph 1, A pressure sensor in which the second electrode layer and the third electrode layer each comprise a plurality of electrodes.

6. In Paragraph 5, A pressure sensor in which a plurality of electrodes included in the second electrode layer and a plurality of electrodes included in at least one electrode layer among a plurality of electrodes included in the third electrode layer are arranged in a certain pattern.

7. In Paragraph 5, A plurality of electrodes included in the second electrode layer are spaced apart from each other along the second horizontal direction, and A plurality of electrodes included in the third electrode layer are spaced apart from each other along the first horizontal direction, and A pressure sensor in which the first horizontal direction and the second horizontal direction are directions perpendicular to the thickness direction of the pressure sensor.

8. In Paragraph 1, It further includes at least one bonding layer, and A pressure sensor, wherein the above-mentioned at least one bonding layer is disposed in at least one of the following: between the first electrode layer and the first elastic dielectric layer, between the first elastic dielectric layer and the second electrode layer, between the second electrode layer and the second elastic dielectric layer, and between the second elastic dielectric layer and the third electrode layer.

9. In Paragraph 1, A pressure sensor in which the first elastic dielectric layer and the second elastic dielectric layer are composed of different elastic dielectrics.

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