KR20180117894A - Pressure sensing sensor and pressure sensing apparatus comprising the same - Google Patents

Abstract

A pressure sensing sensor according to one embodiment of the present invention comprises: a first electrode layer connected to a first electrode; a middle layer arranged on the first electrode layer; and a second electrode layer arranged on the middle layer, and connected to a second electrode having an opposite polarity with the first electrode, wherein the middle layer includes a foam having a spread porous area within a non-porous area, and conductive particles spread within the foam and having larger conductivity than that of the foam. The density of the middle layer is 0.1 g/cm^3 to 0.28 g/cm^3, and an aspect ratio of the porous area is 1 to 1.2-5.

Description

TECHNICAL FIELD [0001] The present invention relates to a pressure sensing sensor and a pressure sensing device including the pressure sensing sensor.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to pressure sensing, and more particularly, to a sensor and apparatus for sensing pressure.

There is a need for a device for sensing pressure in a variety of applications utilizing home pressure safety as well as pressure distribution.

The pressure sensing device includes a lower electrode, an intermediate layer disposed on the lower electrode, and an upper electrode disposed on the intermediate layer. The intermediate layer may be an elastic body in which conductive particles are dispersed. The pressure applied on the pressure sensing device can be detected using the principle that the resistance of the intermediate layer changes. The performance of such a pressure sensing device may be affected by the elastic restoring force and the conducting performance of the intermediate layer.

Generally, the intermediate layer can be manufactured by immersing a base material in an elastic solution in a conductive solution, followed by washing and drying. In this case, depending on the repetitive use of the pressure sensing device, the conductive particles adhered to the surface of the elastic substrate may be detached, and the separated conductive filler may not only be a source of contaminants but also cause the sensor sensitivity of the pressure sensing device .

Further, since it is difficult to uniformly disperse the conductive particles in the elastic body, there is a problem that the width of the variable resistors appears unevenly even in one pressure sensing device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pressure sensing device for sensing a pressure according to an applied weight.

A pressure sensor according to an embodiment of the present invention includes a first electrode layer connected to a first electrode, an intermediate layer disposed on the first electrode layer, and a second electrode layer disposed on the intermediate layer, And a second electrode layer connected to the second electrode, wherein the intermediate layer includes a foam in which void regions are dispersed in a non-void region, and conductive particles dispersed in the foam and having a conductivity higher than that of the foam, density is 0.1g / cm ³ to 0.28g / cm ^3, the aspect ratio of the gap region is 1: 1.2 to 5.

The aspect ratio of the void region may be 1 to 1.5 to 3.

The intermediate layer has a tensile strength of 1 kg / mm ² or more, a tear strength of 0.2 kg / cm or more, and a elongation of 100% or more.

At least a portion of the conductive particles may be dispersed in the surface of the non-pervious region and in the pervious region.

The conductive particles may include a first conductive particle and a second conductive particle different from the first conductive particle.

Wherein the electrical conductivity of the second conductive particle is higher than the electrical conductivity of the first conductive particle, the first conductive particle is dispersed in the surface of the non-void region and in the void region, Or may penetrate the boundary between the non-pored region and the pore region.

According to another aspect of the present invention, there is provided a pressure sensor including: a first electrode layer including a first conductive region connected to a first electrode; a first electrode layer disposed on the horizontal surface and spaced apart from the first electrode layer, And an intermediate layer disposed on the first electrode layer and the second electrode layer, wherein the intermediate layer has a void region dispersed in a non-void region, foam (foam) and is dispersed in the form comprises a greater conductivity than the conductive particles form, the density of the intermediate layer is 0.1g / cm ³ to 0.28g / cm ^3, the aspect ratio of the gap region is 1: 1.2 to 5.

A pressure sensing apparatus according to an embodiment of the present invention includes a pressure sensing sensor, a signal processing unit connected to the pressure sensing sensor, for processing electrical signals generated by the pressure sensing sensor, and a controller connected to the signal processing unit, Wherein the pressure sensing sensor includes a first electrode layer connected to the first electrode, an intermediate layer disposed on the first electrode layer, and a second electrode layer disposed on the intermediate layer, And a second electrode layer connected to a second electrode having a polarity opposite to that of the first electrode, wherein the intermediate layer comprises a foam having a void region dispersed in a non-void region and a second electrode layer dispersed in the foam, includes a large conductive particles, and the density of the intermediate layer is 0.1g / cm ³ to 0.28g / cm ^3, the aspect ratio of the gap region is 1: 1.2 to 5.

The pressure sensing device according to the embodiment of the present invention can precisely detect the pressure according to the applied weight and accurately detect the pressure distribution.

Particularly, according to the embodiment of the present invention, it is possible to obtain a pressure sensing device having high durability and high elastic restoring force by minimizing the detachment of the conductive filler. Further, according to the embodiment of the present invention, the manufacturing process can be simplified.

Further, according to the embodiment of the present invention, it is possible to obtain a pressure sensing device in which the variation of the resistance value is reduced and the reliability is improved.

1 is a perspective view of a pressure sensing sensor according to an embodiment of the present invention.
2 is a perspective view of a pressure sensing sensor according to another embodiment of the present invention.
3 is a schematic cross-sectional view of an intermediate layer included in the pressure sensor according to an embodiment of the present invention.
4 is an enlarged view of an intermediate layer according to an embodiment of the present invention.
5 is an enlarged view of an intermediate layer according to another embodiment of the present invention.
6 is an enlarged view of an intermediate layer according to another embodiment of the present invention.
7 is a flow chart showing a method of manufacturing the intermediate layer of Fig.
8 is a flow chart showing a method of manufacturing the intermediate layer of Fig.
9 is a flow chart showing a method of manufacturing the intermediate layer of Fig.
10 is an SEM photograph of the intermediate layer produced according to the comparative example.
11 is a SEM photograph of an intermediate layer manufactured according to an embodiment of the present invention.
FIG. 12 is a graph showing the resistance values of the intermediate layer prepared according to the comparative example, measured at seven sensing points.
FIG. 13 is a graph showing the resistance values of the intermediate layer according to the embodiment, measured at seven sensing points.
14 is a cross-sectional view of a pressure sensing sensor according to another embodiment of the present invention.
15 is a block diagram of a pressure sensing device according to an embodiment of the present invention.

The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated and described in the drawings. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms including ordinal, such as second, first, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as a first component, and similarly, the first component may also be referred to as a second component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

In describing embodiments, it is to be understood that each layer (film), area, pattern or structure may be referred to as being "on" or "under" a substrate, layer, Includes all that is formed directly or via another layer. The criteria for top / bottom or bottom / bottom of each layer are described with reference to the drawings. In addition, the thickness or size of each layer (film), region, pattern or structure in the drawings may be modified for clarity and convenience of explanation, and thus does not entirely reflect the actual size.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, wherein like or corresponding elements are denoted by the same reference numerals, and redundant description thereof will be omitted.

FIG. 1 is a perspective view of a pressure sensing sensor according to an embodiment of the present invention, and FIG. 2 is a perspective view of a pressure sensing sensor according to another embodiment of the present invention.

1 and 2, the pressure sensor 100 includes a first electrode layer 110, a second electrode layer 120, an intermediate layer 130 disposed between the first electrode layer 110 and the second electrode layer 120, ). The first electrode layer 110 may be connected to a first electrode (not shown), and the second electrode layer 120 may be connected to a second electrode (not shown) having a polarity opposite to that of the first electrode layer. Although not shown, the first electrode and the second electrode may be connected via a rigid printed circuit board or a flexible printed circuit board. The intermediate layer 130 may be an elastic body in which conductive particles are dispersed.

Here, the first electrode layer 110 and the second electrode layer 120 may be a plating electrode or a printing electrode, and may be a flexible and stretchable electrode. For this purpose, the plating electrode or printing electrode may be formed on a flexible and stretchable base substrate, which may be, for example, an ester-based fabric or a urethane-based film, but is not limited thereto.

Alternatively, the first electrode layer 110 and the second electrode layer 120 may include conductive fibers. Here, the conductive fiber may be a metal wire or a plain fiber coated with a metal film on the surface. The conductive fibers may be ordinary fibers in which metal particles are dispersed. When the conductive fiber is a metal wire, the diameter of the metal wire may be 10 탆 to 500 탆. If the diameter of the metal wire is less than 10 mu m, the strength of the metal wire may be too weak to process the fabric. If the diameter of the metal wire exceeds 500 mu m, the rigidity of the metal wire may be high, It can damage the equipment, and the user is likely to feel a sense of heterogeneity. At this time, the metal wire may be Cu, Ni, or a stainless steel alloy. The stainless alloy may be, for example, a martensitic stainless alloy, a ferritic stainless alloy, an austenitic stainless alloy, a two-phase stainless alloy, a precipitation hardening stainless alloy, or the like. When the metal wire is a stainless steel alloy, corrosion resistance of the pressure sensor 100 can be increased. When the conductive fiber is a general fiber coated with a metal film on its surface, the metal film may be formed by a method in which the metal particles are coated on the surface of the common fiber by a plating method or a vapor deposition method. At this time, the metal particles may be Cu, Ni, or a stainless alloy, and the thickness of the metal film may be 1 to 50 탆. If the thickness of the metal film is less than 1 탆, the conductivity may be low, which may cause a loss in signal transmission. If the thickness of the metal film exceeds 50 탆, the metal film may be easily separated from the surface of the fiber.

1, the entire first electrode layer 110 may form the first conductive region, and the entirety of the second electrode layer 120 may form the second conductive region.

Alternatively, as shown in FIG. 2, the first electrode layer 110 may include a first conductive region 112, and the second electrode layer 120 may include a second conductive region 122. Here, the first conductive region 112 and the second conductive region 122 may be a plating electrode or a printing electrode formed on the base substrate. Alternatively, the first electrode layer 110 and the second electrode layer 120 may be formed of a fabric, and the first conductive region 112 and the second conductive region 122 may be formed of a fabric including conductive fibers. Here, the fabric means a fabric in which the warp yarns and the weft yarns are interwoven one above the other, and can include nonwoven fabrics arranged in an irregular manner as well as regularly interwoven fabrics of warp and weft yarns.

Here, the first conductive region 112 of the first electrode layer 110 and the second conductive region 122 of the second electrode layer 120 may be formed in different directions, and the first conductive region 112 and the second conductive region 122 may be formed in different directions. The point where the two conductive regions 122 intersect can serve as a single sensing point.

Accordingly, when the sensing point is pressed, the distance between the first conductive region 112 and the second conductive region 122, that is, the thickness of the intermediate layer 130, is reduced. As the applied force increases, at least one of the thickness and the volume of the intermediate layer 130 decreases, the density of the conductive material per unit volume of the intermediate layer 130 increases, and the distance between the conductive materials may become closer. The intermediate layer 130 has an insulating property in a steady state but may be damaged when a physical change occurs around the intermediate layer 130 or when a pressure is applied to the intermediate layer 130, Or volume, the piezoresistance is lowered. When the pressure resistance of the intermediate layer 130 is lowered, the pressure sensing sensor 100 according to the embodiment of the present invention can sense the weight according to the amount of change in the piezoresistance.

Although not shown, the first conductive region 112 may be formed to be larger than the second conductive region 122, and a plurality of second conductive regions 122 may be formed on one of the first conductive regions 112 have.

According to the embodiment of the present invention, the structure of the intermediate layer is changed to reduce the deviation of the variable resistance of the intermediate layer, to enhance the durability, and to improve the pressure sensing performance.

FIG. 3 is a schematic cross-sectional view of an intermediate layer included in a pressure-sensitive sensor according to an embodiment of the present invention, FIG. 4 is an enlarged view of an intermediate layer according to an embodiment of the present invention, FIG. 6 is an enlarged view of an intermediate layer according to another embodiment of the present invention. FIG. FIG. 7 is a flow chart showing a method for manufacturing the intermediate layer in FIG. 4, FIG. 8 is a flowchart showing a method for manufacturing the intermediate layer in FIG. 5, and FIG. 9 is a flowchart showing a method for manufacturing the intermediate layer in FIG.

3 to 6, the intermediate layer 130 includes a foam in which the void region 134 is dispersed in the non-void region 132, and conductive particles 136 dispersed in the foam and having higher conductivity than the foam.

Here, the non-pored region 132 of the foam may comprise at least one selected from the group consisting of polyurethane, polyolefin, rubber, silicone and elastomer. When the void region 134 is dispersed in the non-void region 132 of the foam, the intermediate layer 130 may have elasticity. Accordingly, if a pressure is applied to a point where the first electrode layer 110 and the second electrode layer 120 intersect, the thickness of the intermediate layer 130 is reduced, and the piezoresistance changes. At this time, the foam may be in a form in which the void region 134 is dispersed in the non-voided region 132.

At this time, the density of the intermediate layer 130 is 0.1 g / cm ³ to 0.28 g / cm ³ , preferably 0.12 g / cm ³ to 0.18 g / cm ³ , and the width of the gap region 134 The aspect ratio can be 1 to 1.2 to 5, preferably 1.5 to 3.

If the density of the intermediate layer 130 is less than 0.1 g / cm ³ , the conductive particles 136 are likely to be detached, the elastic restoration of the foam is deteriorated, the performance of the pressure sensing sensor is not secured, If it exceeds 0.28 g / cm ³ , the deformation of the thickness is small, and the change in the piezoresistance is not measured or the weight sensing section becomes small.

If the ratio of the aspect ratio of the void region 134 is less than 1.2 to 1.2, the conductive particles 136 are likely to be detached. If the aspect ratio of the void region 134 exceeds 1 to 5, Is not measured or the weight detection classification becomes small.

The conductive particles 136 may include the first conductive particles 136-1 and the second conductive particles 136-2 which are different from the first conductive particles 136-1. At this time, the electrical conductivity of the second conductive particles 136-2 may be higher than the electrical conductivity of the first conductive particles 136-1. As described above, when the different types of conductive particles having different electric conductivities are dispersed in the intermediate layer 130, the range of the resistance value that varies depending on the pressure can be widened. Accordingly, the range of the pressure that can be sensed can be widened, and the precision of the pressure sensing can be enhanced. Here, the conductive particles may be selected from the group consisting of Au, Ag, Cu, Ni, a carbon-based material, a ceramic material, and a conductive polymer. At this time, the conductive polymer may include polyaniline or polypyrrole. The ceramic material may be, for example, a microcarbon coil barium titanate having a diameter of 100 mu m or less.

For example, the first conductive particles 136-1 may be amorphous carbon, and the second conductive particles 136-2 may be crystalline carbon. Crystalline carbon has higher electrical conductivity than amorphous carbon. For example, the first conductive particles 136-1 may include carbon black, and the second conductive particles 136-2 may be selected from the group consisting of carbon nanotubes, graphene, and graphite.

As described above, when the conductive particles 136 included in the intermediate layer 130 include not only amorphous carbon but also crystalline carbon, not only the range of the resistance value varying by the amorphous carbon but also the resistance value varying by the crystalline carbon Range can be covered, so that the range of the resistance value varying depending on the pressure can be widened. At this time, the conductive particles 136 may be contained in an amount of 1 to 10 wt% of the intermediate layer 130. When the conductive particles 136 contain less than 1 wt% of the intermediate layer 130, a change in the resistance of the pressure resistance at the time of pressurization may be insensitive. When the conductive particles 136 are contained in an amount of more than 10 wt% of the intermediate layer 130, it is difficult to ensure the insulating property of the intermediate layer 130 in the state where no pressure is applied, ), Which are not uniformly dispersed.

At this time, the amount of the first conductive particles 136-1 relative to 10 parts by weight of the second conductive particles 136-2 is 20 parts by weight or more and less than 100 parts by weight, preferably 20 parts by weight or more and less than 50 parts by weight, May be included in an amount of 20 parts by weight or more and less than 30 parts by weight. If the amount of the first conductive particles 136-1 is less than 20 parts by weight or exceeds 100 parts by weight based on 10 parts by weight of the second conductive particles 136-2, And the conductive particles can be aggregated without being evenly dispersed in the intermediate layer 130. For example, the second conductive particles 136-2 may be contained in an amount of 0.5 to 2.5 wt%, preferably 1 to 2 wt%, more preferably 1.2 to 1.8 wt% of the intermediate layer 130, The particles 136-1 may be contained in an amount of 1 to 7.5 wt%, preferably 2 to 6 wt%, and more preferably 2.4 to 5.4 wt% of the intermediate layer 130.

These conductive particles 136 may be dispersed in the surface of the non-void region 132 or in the void region 134 as shown in FIG. 4, or in the non-void region 132, Or may be dispersed to pass through the interface between the region 132 and the void region 134 or may be dispersed in the non-void region 132 as shown at 6, the interface between the non-void region 132 and the void region 134, May be dispersed within the surface or void region 134 of the substrate 132.

5 to 6, if at least a portion of the conductive particles 136 are dispersed in the non-void region 132 or dispersed to pass through the interface between the non-void region 133 and the void region 134, The particles 136 may be secured within the foam. Accordingly, it is possible to reduce the possibility that the conductive particles are separated from the intermediate layer 130 even when the pressure sensing sensor 100 is repeatedly used for a long time.

At this time, the conductive particles dispersed in the non-apertured region 132 with respect to the entire conductive particles 136 included in the intermediate layer 130 or dispersed through the interface between the non-apertured region 132 and the void region 134 are 20 wt % Or more, preferably 30 wt% or more, and more preferably 50 wt% or more. If less than 20 wt% of the conductive particles are dispersed in the non-pored area 132 or dispersed so as to pass through the interface between the non-pored area 132 and the pore area 134, contamination may occur due to the detachment of the conductive particles, The sensitivity can be reduced.

Particularly, as shown in Fig. 6, the first conductive particles 136-1 are dispersed in the surface of the non-void region 132 or in the void region 134, and the second conductive particles 136-2 are dispersed in the non- At least a portion of the second conductive particles 136-2 may be dispersed within the region 132 and may pass through the interface between the non-void region 132 and the void region 134. [

At this time, the second conductive particles 136-2 covering the low resistance value range due to the high electric conductivity are dispersed in the non-air-tight region 132, and the first conductive particles 136-2 covering the high resistance value range The second conductive particles 136-2 are less likely to be separated from the first conductive particles 136-1 even if the number of times of pressing with respect to the intermediate layer is increased. Thus, the ability to maintain a wide range of resistance value changes even in repeated use can be maintained.

This intermediate layer can be prepared by the following method.

7, to provide a foam density of 0.02g / cm ³ to 0.04g / cm ³ (S700). Here, the foam may include at least one selected from the group consisting of polyurethane, polyolefin, rubber, silicone and elastomer.

Next, the formed foam is immersed in a solution in which the conductive particles are dispersed, and then washed and dried (S710). Here, the conductive particles may be selected from the group consisting of Au, Ag, Cu, Ni, carbon nanotube (CNT), carbon black, graphene, ceramic material and conductive polymer. At this time, the conductive polymer may include polyaniline or polypyrrole. The ceramic material may be, for example, a microcarbon coil barium titanate having a diameter of 100 mu m or less.

 Next, the form is compressed (S720). At this time, the compression ratio may be 1/7 to 1/5. For example, the foam dried in step S710 may be compressed to a thickness of 1/7 to 1/5.

Referring to FIG. 8, the substrate and the conductive particles are mixed (S800). The base material may include at least one selected from the group consisting of polyurethane, polyolefin, rubber, silicone and elastomer, and the conductive particles may be at least one selected from the group consisting of Au, Ag, Cu, Ni, carbon nanotube (CNT) Fins, ceramic materials, and conductive polymers. At this time, the conductive material may be contained in 1 to 10 wt% of the substrate.

Next, the mixed base material and the conductive material are foam-molded (S810). At this time, the density of the foam-molded foam may be 0.02 g / cm ³ to 0.04 g / cm ³ .

Next, the form is compressed (S820). At this time, the compression ratio may be 1/7 to 1/5. For example, in step S810 foam foamed foams may be compressed to a thickness of 1/7 to 1/5.

9, the substrate and the second conductive particles are mixed (S900). The base material may include at least one selected from the group consisting of polyurethane, polyolefin, rubber, silicone and elastomer, and the conductive particles may be at least one selected from the group consisting of Au, Ag, Cu, Ni, carbon nanotube (CNT) Fins, ceramic materials, and conductive polymers.

Next, the mixed base material and the second conductive particles are foam-molded (S910). At this time, the density of the foam-molded foam may be 0.02 g / cm ³ to 0.04 g / cm ³ .

Next, the formed foam is dipped in a solution in which the first conductive particles are dispersed, and then washed and dried (S920). The first conductive particles may be selected from the group consisting of Au, Ag, Cu, Ni, carbon nanotubes (CNTs), carbon black, graphene, ceramic materials and conductive polymers, Lt; / RTI > At this time, the electrical conductivity of the second conductive particles may be higher than the electrical conductivity of the first conductive particles.

Next, the form is compressed (S930). At this time, the compression ratio may be 1/7 to 1/5. For example, the foam dried in step S920 may be compressed to a thickness of 1/7 to 1/5.

As described in FIGS. 7 to 9, when the foam having an initial density of 0.02 g / cm ³ to 0.04 g / cm ³ is compressed to a thickness of 1/7 to 1/5, the final density is 0.1 g / cm ³ to 0.28 g / cm < ³ >, and the aspect ratio of the void region is 1 to 1.2 to 5.

Thus, if the initial density is impregnated with a form that when the impregnation of 0.02g / cm ³ to 0.04g / cm ³ to form a conductive particle dispersed solution, exceeding 0.04g / cm ³ in which the conductive particle dispersion solution The conductive particles can be uniformly arranged on the foam. Further, when the foam is compressed to a thickness of 1/7 to 1/5, an intermediate layer with improved physical properties can be obtained with a higher compression ratio. That is, an intermediate layer having an aspect ratio of 1: 1.2 to 5 is obtained, and the conductive particles are trapped in the void region, so that the possibility of detaching the conductive particles after repeated use for a long time is low. In addition, tensile strength, tear strength and elongation are increased. For example, the intermediate layer prepared according to the embodiment of the present invention may have a tensile strength of 1 kg / mm ² or more, a tear strength of 0.2 kg / cm or more, and a elongation of 100% or more. When the tensile strength, tear strength and elongation of the intermediate layer satisfy the above conditions, a pressure sensing sensor having excellent durability can be obtained while the elastic force is high and the range of the variable resistance is wide.

Hereinafter, the present invention will be described in more detail with reference to Comparative Examples and Examples.

FIG. 10 is an SEM photograph of an intermediate layer produced according to a comparative example, and FIG. 11 is an SEM photograph of an intermediate layer manufactured according to an embodiment of the present invention. FIG. 12 is a graph showing the resistance values of the intermediate layer prepared according to the comparative example at seven sensing points, FIG. 13 is a graph showing the resistance values of the intermediate layer prepared according to the embodiment at seven sensing points, to be.

In the comparative example, an intermediate layer was prepared by dipping a foam having an initial density of 0.07 / g / cm ³ and a thickness of ³ T in a solution in which conductive particles were dispersed, followed by washing and drying, and compressing to a thickness of 1 T.

In the practice, an intermediate layer was prepared by dipping a foam having an initial density of 0.03 g / cm ³ and a thickness of 6 T in a solution in which conductive particles were dispersed, followed by washing and drying, and compressing to a thickness of 1 T.

The foams used in the comparative examples and the examples were polyurethane, the conductive particles were CNT, and the conductive particles were added at 3 wt% with respect to the total foam.

Table 1 shows the density, aspect ratio, tensile strength, tear strength and elongation of the intermediate layer according to the comparative example and the example. Table 2 shows the resistance value of the intermediate layer according to the comparative example measured at 7 sensing points And Table 3 shows the resistance value of the intermediate layer according to the embodiment measured at seven sensing points.

Properties Comparative Example Example Density (g / cm ³⁾ 0.21 0.18 Tensile strength (kg / mm ² ) 0.26 3.48 Tear strength (kg / cm) 0.16 0.34 Elongation (%) 56 115

Referring to Fig. 10 to 11 and Table 1, the final density of the intermediate layer made in accordance with the intermediate layer is manufactured as in Example according to the comparative example is prepared according to a similar, comparative example to 0.21g / cm ³ and 0.18g / cm ³ The aspect ratio of the void region of the intermediate layer is 1 to 1 to 1.2 but the aspect ratio of the void region of the intermediate layer produced according to the embodiment is 1.2 to 5 per 1. As a result, the conductive particles become trapped in the void region, and the possibility that the conductive particles are separated from the foam is lowered.

Also, referring to Table 1, it can be seen that the physical properties of the intermediate layer prepared according to Examples, such as tensile strength, tearing strength and elongation, are improved compared to those of the intermediate layer prepared according to the comparative example. Thus, it can be seen that the durability and pressure sensing performance of the intermediate layer produced according to the embodiment is improved.

Referring to FIGS. 12 to 13 and Tables 2 and 3, it can be seen that, in the case of the intermediate layer manufactured according to the embodiment, the uniformity of the resistance variation by sensing points is higher than that of the intermediate layer manufactured according to the comparative example. That is, when the pressure is applied to seven sensing points in the range of 1 to 600 Kpa, the standard deviation of the resistance change of the intermediate layer prepared according to the comparative example is represented by 1.40E + 06 to 2.36E + 09, And the standard deviation of the resistance change of the intermediate layer is 3.22E + 04 to 3.12E + 07. In particular, when the pressure is applied to seven sensing points in the range of 100 to 600 Kpa, the standard deviation of the resistance change of the intermediate layer prepared according to the comparative example is represented by 1.40E + 06 to 2.02E + 07, It can be seen that the standard deviation of the resistance change of the intermediate layer is remarkably reduced to 3.22E + 04 to 1.60E + 05. From this, it can be seen that the conductive particles are evenly dispersed in the intermediate layer produced according to the embodiment as compared with the intermediate layer prepared according to the comparative example, and a more reliable pressure sensing sensor can be obtained.

12 to 13 and Tables 2 to 3, in the case of the intermediate layer prepared according to the embodiment in comparison with the intermediate layer prepared according to the comparative example, the average value of the resistance for seven sensing points Is low. As described above, in the case of the intermediate layer manufactured according to the embodiment, since the electric conductivity is higher than that of the intermediate layer prepared according to the comparative example, the pressure sensing performance is excellent.

In the above description, the intermediate layer is formed between the first electrode layer and the second electrode layer. However, the first electrode layer and the second electrode layer may be disposed on the same plane.

14 is a cross-sectional view of a pressure sensing sensor according to another embodiment of the present invention. 1 to 13 will not be described.

Referring to FIG. 14, the pressure sensing sensor 100 includes a first electrode layer 110 including a first conductive region, a second electrode layer 120 including a second conductive region, and an intermediate layer 130.

The second electrode layer 120 may be disposed on the horizontal surface of the first electrode layer 110 and the intermediate layer 130 may be disposed on the first electrode layer 110 or the second electrode layer 120.

Thereby, ground connection is possible in one layer, and it is not necessary to provide an additional grounding electrode, so that the material cost and manufacturing cost of the pressure sensing sensor 100 can be reduced and the thickness of the pressure sensing sensor 100 can be reduced.

The first electrode layer 110 and the second electrode layer 120 may be bonded to the intermediate layer 130 through the adhesive layer 140. At this time, the adhesive layer 140 may include an insulator, and may be disposed between one region of the first electrode layer 110 and one region of the second electrode layer 120 and the middle layer 130.

The adhesive layer 140 may be spaced apart from the first electrode layer 110 and the second electrode layer 120. Further, the adhesive layer 140 may be a structure in which an insulating adhesive is coated on both sides of the film. At this time, the adhesive layer 140 may be disposed in only a part of the first electrode layer 110 and a part of the second electrode layer 120. For example, the adhesive layer 140 may be disposed in an area other than an edge of the first electrode layer 110 and an edge of the second electrode layer 120. Accordingly, when a pressure is applied on the pressure sensor, the edge of the first electrode layer 110 directly contacts the middle layer 130, and the edge of the second electrode layer 120 can directly contact the middle layer 130 , The current can flow through the intermediate layer 130 without any error caused by the adhesive layer 140. [

When pressure F is applied on the pressure sensing sensor 100, the thickness of the elastic intermediate layer 130 changes. Due to the thickness variation of the intermediate layer 130, the first electrode layer 110 and the second electrode layer 120 spaced apart from each other are connected to each other through the intermediate layer 130 to allow electricity to pass therethrough. Then, the degree of pressure is detected from the generated electric signal. Here, the intermediate layer 130 may have a structure according to the embodiment of the present invention described with reference to FIGS.

The pressure sensing sensor according to an embodiment of the present invention may be included in the pressure sensing device.

15 is a block diagram of a pressure sensing device according to an embodiment of the present invention.

Referring to FIG. 15, the pressure sensing device 200 may include a pressure sensing sensor 100, a signal processing unit 210, a control unit 220, and a communication unit 230. The pressure sensing sensor 100 may generate an electrical signal due to a resistance change according to a change of at least one of the thickness and the volume of the intermediate layer 130 according to an embodiment of the present invention. The electric signals of the first electrode layer 110 and the second electrode layer 120 are transmitted to the signal processing unit 210. The first electrode layer 110 and the second electrode layer 120 may be connected to the signal processing unit 210 by a flexible printed circuit board (FPCB).

The signal processing unit 210 processes the electrical signal received from the first electrode layer 110 and the second electrode layer 120 and transmits the processed electrical signal to the control unit 220. The control unit 220 receives the signal processed by the signal processing unit 210 The control signal can be generated. For example, the control unit 220 can control the on / off state of the pressure sensing device 200 by using the result of processing the signal sensed by the pressure sensing sensor 100. In another example, the controller 220 may generate diagnostic information using the result of processing the signal sensed by the pressure sensor 100. As another example, the controller 220 may generate an alarm signal for the user by using the result of processing the signal sensed by the pressure sensor 100.

The communication unit 230 transmits the control signal generated by the control unit 220 to the external device.

At this time, the pressure sensing sensor 100 is disposed in a space independent from the signal processing unit 210, the control unit 220, and the communication unit 230, and may be connected through the FPCB. Alternatively, the pressure sensing sensor 100 may be disposed in the same space as the signal processing unit 210, the control unit 220, and the communication unit 230, and may be connected through the FPCB.

The pressure sensing sensor according to an embodiment of the present invention can be applied to various applications using pressure distribution such as a pressure sensing insole, a pressure sensing glove, a pressure sensing mat, a pressure sensing chair, a home safety device, and the like.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims. It can be understood that

100: Pressure sensor
110: first electrode layer
120: second electrode layer
130: middle layer

Claims (8)

A first electrode layer connected to the first electrode,
An intermediate layer disposed on the first electrode layer, and
And a second electrode layer disposed on the intermediate layer and connected to a second electrode having a polarity opposite to that of the first electrode,
Wherein the intermediate layer comprises a foam having void regions dispersed in a non-void region, and conductive particles dispersed in the foam and having a higher conductivity than the foam,
The density of the intermediate layer is 0.1g / cm ³ to 0.28g / cm ^3, the aspect ratio of the gap region is in one-to-1.2 to 5, the pressure sensor. The method according to claim 1,
Wherein the aspect ratio of the void region is 1 to 1.5 to 3. The method according to claim 1,
Wherein the intermediate layer has a tensile strength of 1 kg / mm ² or more, a tear strength of 0.2 kg / cm or more, and a elongation of 100% or more. The method according to claim 1,
And at least a part of the conductive particles are dispersed in the surface of the non-void region and in the void region. The method according to claim 1,
Wherein the conductive particles comprise a first conductive particle and a second conductive particle different from the first conductive particle. 6. The method of claim 5,
Wherein the electric conductivity of the second conductive particles is higher than the electric conductivity of the first conductive particles,
Wherein the first conductive particles are dispersed in the surface of the non-void region and in the void region, and the second conductive particles are dispersed in the non-void region or pass through a boundary between the non- . A first electrode layer including a first conductive region connected to the first electrode,
A second electrode layer disposed on the horizontal surface of the first electrode layer and including a second conductive region connected to a second electrode having a polarity opposite to the first electrode,
And an intermediate layer disposed on the first electrode layer and the second electrode layer,
Wherein the intermediate layer comprises a foam having void regions dispersed in a non-void region, and conductive particles dispersed in the foam and having a higher conductivity than the foam,
The density of the intermediate layer is 0.1g / cm ³ to 0.28g / cm ^3, the aspect ratio of the gap region is in one-to-1.2 to 5, the pressure sensor. Pressure sensor,
A signal processor connected to the pressure sensor for processing an electrical signal generated by the pressure sensor,
A control unit connected to the signal processing unit and generating a control signal based on the signal processed by the signal processing unit,
/ RTI >
The pressure sensor
A first electrode layer connected to the first electrode,
An intermediate layer disposed on the first electrode layer, and
And a second electrode layer disposed on the intermediate layer and connected to a second electrode having a polarity opposite to that of the first electrode,
Wherein the intermediate layer comprises a foam having void regions dispersed in a non-void region, and conductive particles dispersed in the foam and having a higher conductivity than the foam,
The density of the intermediate layer is 0.1g / cm ³ to 0.28g / cm ^3, the aspect ratio of the gap region is in one-to-1.2 to 5, the pressure sensing device.

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