KR101210937B1 - Pressure Sensitive Device And Tactile Sensors Using The Same - Google Patents

Abstract

The present invention is attached to the product for the exterior or interior of electronic and electrical appliances, components, automobiles, machinery, etc., and usually acts as an insulating film, and when a certain pressure or shock is applied, the pressure is changed to a conductive film so as to conduct electricity. The present invention relates to a device and a tactile sensor using the same, to provide a pressure sensitive device including a first electrode and a second electrode, a nonconductive elastic layer filled therebetween, and conductive filler particles sprayed onto the elastic polymer material layer. By adjusting the arrangement and content of the conductive filler particles, the present invention is superior to the conventional pressure sensor, and relates to an invention that makes it possible to more easily perform the prevention function by external impact.

Description

Pressure Sensitive Device And Tactile Sensors Using The Same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure sensitive element that normally functions as an insulating film, and converts into a conductive film when the pressure or shock is applied to the conductive film, and a tactile sensor formed using the same.

Conventional pressure sensors include mechanical pressure sensors, electric pressure sensors, and semiconductor pressure sensors.

Mechanical pressure sensors are mainly used for elasticity, such as full dome tube using elasticity of closed tube, bellows using change of pressure of gas and repulsive force of spring, and diaphragm using thin diaphragm. Etc.

Most electric pressure sensors convert mechanical displacements into electrical signals. Capacitives measure the displacement between capacitances between two electrodes, and force generated in proportion to the measured pressure and externally generated forces. There is an inverse balanced pressure sensor that balances the measured pressure with current and voltage.

The semiconductor pressure sensor has no hysteresis phenomenon, has excellent linearity, small size and light weight, and is very resistant to vibration, and has been used more and more recently because of its high sensitivity, high reliability, and excellent mass production.

The semiconductor pressure sensor chemically etches single crystal silicon to form a diaphragm, converts the stress generated from the diaphragm into an electrical signal, and measures the pressure to create a resistance on the diaphragm. The piezo-resistive effect is a piezo-resistive effect measuring pressure using a piezo-resistive effect. There is a capacitive type that measures the pressure by changing the capacitance between the electrodes and changing the capacitance between the electrodes.

The pressure sensors are variously applied to various home appliances such as refrigerators, air conditioners, automobile parts, general industrial devices, and semiconductor devices such as wafer adsorption pressure detection, and medical devices such as artificial heart.

However, the mechanical pressure sensor, the electric pressure sensor, and the semiconductor pressure sensor are not universal in terms of accuracy or magnitude of pressure, and thus there is inconvenience in that they are distinguished for each use purpose.

In addition, as the field of use is gradually increased, the market demands are diversified, and thus a more sensitive and reliable pressure sensor is required. However, there are limitations in developing different pressure sensors.

In addition, the conventional MEMS structure tactile sensor is complicated in structure, expensive, and due to limitations in use, there is a problem that it is difficult to apply to various fields and mass production.

According to the present invention, a pressure is applied to the first or second electrode by filling a non-conductive elastic layer in a region between the first electrode and the second electrode provided to be spaced apart from each other, and dispersing the conductive filler particles in the non-conductive elastic layer. Conductive filler particles can be connected to create an electrical tunneling effect. In this case, when a small driving voltage is applied to the first electrode and the second electrode, a change in current and resistance can be easily measured according to the presence and magnitude of pressure applied to the nonconductive elastic layer. An object of the present invention is to provide a pressure sensitive device capable of realizing high sensitivity and high reliability by efficiently dispersing filler particles and a tactile sensor using the same.

The pressure sensitive device according to the present invention includes a non-conductive elastic layer having conductive filler particles disposed therein and a first electrode and a second electrode formed on both sides of the non-conductive elastic layer, respectively, wherein the first electrode and the When no external force is applied while a driving voltage is applied to the second electrode, the conductive filler particles are kept spaced apart from each other to keep the first electrode and the second electrode insulated from each other. When an external force is applied to the first electrode or the second electrode, the non-conductive elastic layer is compressed in the direction in which the external force is applied, and an electric tunneling effect occurs between the conductive filler particles in the compressed region, thereby generating the first electrode. And an arrangement such that a current flows between the second electrode and the second electrode so that the current can also be increased in proportion to the increase in the external force. It is characterized by including the conductive filler particles.

Here, the first electrode and the second electrode is characterized in that each formed to a thickness of 0.1㎛ ~ 5㎜, the first electrode and the second electrode is a film or polygon using a flexible conductive material (flexible) Characterized in that it is formed in a three-dimensional shape including a pillar, the flexible (flexible) conductive material (polyacetylene) (polyacetylene), polypyrole (polypyrole), polyaniline (polyaniline) and those containing any one selected from those mixed Characterized in that, the non-conductive elastic layer is formed to a thickness of 0.1 ㎛ ~ 5㎜, the non-conductive elastic layer is polyethylene (PE), high density polyethylene (high density PE), low density polyethylene (low density PE), bakelite, neoprene, nylon, polyvinyl chloride (PVC), polystyrene (PS), polyarc Polyacrylonitrile, ultra-high molecular weight polyethylene (UHMWPE), ethylene vinylacetate (EVA), polyvinyl butyral (PVB), polypropylene (PP), poly It is formed by using any one selected from polytetrafluoroethylene (polytetrafluoroethylene) and a mixture of these materials, the conductive filler particles are a spherical, rod-shaped or needle-like material having a size of 10nm ~ 100㎛ Characterized in that, the conductive filler particles are added by 0.05 to 95% by weight relative to the weight of the non-conductive elastic layer, the conductive filler particles are Ag, Au, Al, Cu, Pt, Ni and C ( And at least one selected from carbon-black, wherein the driving voltage applied to the first electrode and the second electrode is 1 kV to 100 V. High, and by the electrical tunneling effect, wherein current 1mA ~ 100A flowing between the first electrode and the second electrode.

In addition, the tactile sensor according to an embodiment of the present invention is characterized in that formed using the pressure sensitive element, provided with the pressure sensitive element alone to measure the strength of the pressure, or a plurality of pressure sensitive elements And measuring the area to which the pressure is applied.

In addition, the pressure sensor according to another embodiment of the present invention is provided with the pressure sensitive element, the first electrode is provided as a front electrode to act as a receiving portion to which the pressure is applied, the second electrode is the position of the pressure and It is characterized in that it is formed in a plurality of patterns so as to grasp the size information in real time.

The present invention is attached to the product for the exterior or interior of electronic and electrical appliances, components, automobiles, machinery, etc., and usually functions as an insulating film, and if a certain pressure or shock is applied, the current amount is linear or nonlinear in proportion to the size. The present invention relates to a pressure-sensitive device and a tactile sensor using the same, wherein the physical properties such as the type, strength, and size of the non-conductive elastic layer or conductive filler particles sensitive to pressure are controlled, and the conductive filler is dispersed in the elastic polymer material layer. By controlling the size and arrangement of the particles, it is better than the conventional pressure sensor, can easily prevent short circuit inside the product by external impact, and ground or spread the current in the desired direction to prevent damage to the product, It provides the effect to detect and prevent explosion and fire in advance. In addition, the present invention provides a simple and efficient manufacturing process compared to the existing tactile sensor, lowers the production cost, and can be applied to various applications because the sensor can be manufactured with a large area of flexibility.

In the present invention, in order to provide a pressure-sensitive device of the new concept to break away from the conventional pressure sensor device concept, a composition in which conductive filler particles are appropriately dispersed according to size, type and content in a polymer material having excellent non-conductive elasticity ( Hereinafter, 'semiconductor polymer composition') is used.

The semiconducting polymer composition is basically a substance in which a conductive material is well dispersed in the crystalline polymer resin and thus acts as a nonconductor at room temperature and in a steady state.

In the present invention, the semiconducting polymer composition performs an insulating film function in a normal state, and when an external shock is applied or a predetermined pressure is applied, the semiconducting polymer composition is converted into a conductive film to perform an energizing function. Therefore, it can act as a pressure sensor that detects a danger when it occurs.

In addition, by controlling the semiconducting polymer composition of the pressure-sensitive device provided in the present invention, a tactile sensor or a pressure sensor that can accurately measure the intensity of the pressure and the area to which the pressure is applied to an electrical signal such as current or resistance It can also work as.

Hereinafter, specific details of other embodiments will be described with reference to the accompanying drawings.

Advantages and features of the present invention, and methods of achieving the same will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

1A and 1B are cross-sectional views showing cross sections of the pressure sensitive element according to the present invention.

Referring to FIG. 1A, the first electrode 130 and the second electrode 140 are provided at predetermined intervals.

In this case, the first electrode 130 and the second electrode 140 may be different depending on the use and function of the pressure-sensitive device, respectively, polyacetylene, polypyrole, polyaniline and polyaniline and They are preferably provided with a thickness of 0.1 μm to 5 mm by using a flexible conductive material including any one selected from mixed materials. In addition, the first electrode 130 and the second electrode 140 may be provided in a plate shape or a film shape formed by a sheet molding machine, and may be provided in various shapes including a three-dimensional shape formed by a casting machine.

Next, the non-conductive elastic layer 100 is filled in an area between the first electrode 130 and the second electrode 140. In this case, conductive filler particles 120 are included in the non-conductive elastic layer 100.

Here, the non-conductive elastic layer 100 is polyethylene (PE), high density polyethylene (high density PE), low density polyethylene (low density PE), bakelite (neoprene), nylon (nylon), Polyvinyl chloride (PVC), polystyrene (PS), polyacrylonitrile, ultra-high molecular weight polyethylene (UHMWPE), ethylene vinylacetate (EVA), poly Polybutylyl butyral (PVB), polypropylene (polypropylene; PP), polysapluorethylene (polytetrafluoroethylene) and any one selected from a mixture of these materials are provided, preferably formed of a thickness of 0.1㎛ ~ 5㎜ Do.

The conductive filler particles 120 may include at least one selected from Ag, Au, Al, Cu, Pt, Ni, and Carbon (black), and have a spherical, rod-shaped or needle-shaped material having a size of 10 nm to 100 μm. And, it is preferably added as much as 0.05 to 95% by weight relative to the weight of the non-conductive elastic layer 100, wherein the conductive filler particles 120 may be mixed in different sizes or different types of particles at the same time.

The pressure 150 may be applied to the first electrode 130 or the second electrode 140 of the pressure sensitive element provided as described above. In FIG. 1B, the pressure 150 is applied to the first electrode 130. Indicates.

The first filler 130 and the non-conductive elastic layer 100 are compressed by the pressure 150, and the conductive filler is dispersed in the area between the compressed point of the first electrode 130 and the second electrode 140. The spacing between the particles 120 is reduced, and the cases in which they are connected to each other occur. At this time, when a driving voltage of 1 kV to 100 V is applied to the first electrode 130 and the second electrode 140, an electric tunneling effect 160 occurs between the conductive filler particles 120 connected to each other. A current of 1 mA to 100 A flows between the first electrode 130 and the second electrode 140.

As the strength of the pressure 150 increases, the area between the first electrode 130 and the second electrode 140 at the compressed point is reduced, so that the electric field and the electric tunneling effect 160 in this area are increased. The current increases and the resistance decreases.

On the other hand, when the force compressing the first electrode 130 is reduced or removed, the gap between the point where the first electrode 130 is compressed by the restoring force of the nonconductive elastic layer 100 and the second electrode 140 are As the electric field effect and the density of the conductive filler particles 120 decrease in the region, the electric tunneling effect decreases again. As the electrical tunneling effect decreases, the amount of current decreases and the resistance increases in inverse proportion to the amount of current.

The change in current or resistance as described above is measured through the first electrode 130 and the second electrode 140, and the strength of the pressure 150 is combined by combining data such as elastic modulus of the nonconductive elastic layer 100. Or you can calculate the area accurately.

2 is a graph illustrating a change in resistivity of a piezoelectric sensitive element according to a change in pressure.

2 is a result of experiments using the embodiment according to FIGS. 1A and 1B, and the electric tunneling effect is increased according to the pressure, and the amount of current is increased when the electric tunneling effect is increased. You can see that (Resistivity) decreases. In addition, there is a difference in resistivity depending on the filler content (Filler Amount), as shown, has a linear or non-linear change, and in the present invention by utilizing the state corresponding to the 'A' region as a tactile sensor or a pressure sensor It can be utilized. The content of the filler (% by weight) indicated here represents the weight of the filler relative to the total weight of the non-conductive elastic layer and the conductive filler particles.
This is the content that appears when the amount of conductive filler particles added by 0.05 to 95% by weight relative to the weight with the non-conductive elastic layer as described in the description of Figure 1a.
As a result, when the addition amount of the conductive filler particles is 10% by weight of the total weight combined with the conductive filler particles and the non-conductive elastic layer, the resistivity is rapidly reduced in the pressure range of 7 to 14 Pa. It can be seen that.
Similarly, when the amount of the conductive filler particles added is 30% by weight of the total weight of the conductive filler particles and the non-conductive elastic layer combined, it can be seen that it can be utilized as a sensor in the pressure range of 6 ~ 13Pa, conductive filler particles When the addition amount of the conductive filler particles and the non-conductive elastic layer is 50% by weight of the combined weight it can be seen that it can be utilized as a sensor in the pressure range of 5 ~ 12Pa.

3 is a schematic diagram illustrating a tactile sensor according to a first embodiment of the present invention.

Referring to FIG. 3, the non-conductive elastic layer 200 including the conductive filler particles 220 arranged regularly, and the first electrode 230 and the second electrode 240 are provided on the upper and lower portions thereof, respectively. Pressure sensitive devices are manufactured in unit sizes to act as tactile sensors that sense the strength of pressure.

When a predetermined pressure 270 is applied to the first electrode 230 of the tactile sensor, the current or resistance of the pressure sensitive element changes accordingly, and the change process is performed by the first connection part 260 and the second connection part 265. The intensity of the pressure 270 may be measured by monitoring in the measuring device 280 and combining the monitored results.

4 is a schematic diagram illustrating a tactile sensor according to a second embodiment of the present invention.

Referring to FIG. 4, the non-conductive elastic layer 300 including the conductive filler particles 320 arranged regularly, and the first electrode 330 and the second electrode 340 are provided on the upper and lower portions thereof, respectively. Pressure sensitive elements are fabricated in unit sizes, and each unit pressure sensitive element is numbered.

Next, by arranging and combining unit pressure sensitive elements 1 to 16 in a matrix form, it acts as a tactile sensor 400 that senses the strength of the pressure and the area to which the pressure is applied.

When a pressure having a predetermined area is applied to a portion where the first electrodes 330 of the tactile sensor 400 are coupled, a current or resistance of a predetermined number of unit pressure sensitive elements is changed, and the change process is performed. The first connection part 360 and the second connection part 365 are monitored in the measuring device 380, and the monitored results may be combined to measure the area and intensity to which the pressure 370 is applied.

5 is a schematic diagram illustrating a pressure sensor according to a third embodiment of the present invention.

Referring to FIG. 5, a nonconductive elastic layer 410 including conductive filler particles is provided at a central portion thereof, and upper and lower electrodes 430 and lower electrodes 440 are provided on both sides of the nonconductive elastic layer, respectively. In this case, the upper electrode 430 is provided as a front electrode to act as a receiving unit to which pressure is applied, and the lower electrode 440 is formed in a plurality of patterns so as to grasp the position and size information of the pressure in real time. Here, the upper electrode 430 and the lower electrode 440 may be formed of an Ag printed thin film in consideration of electrical conductivity and flexibility.

Next, when the lower electrode 440 is provided in a plurality of patterns, the lower electrode 440 may be mounted on the PCB substrate 450 so that the lower electrode 440 may be uniformly connected to the nonconductive elastic layer 410. In addition, the PCB substrate 450 may extend to the outer surface of the non-conductive elastic layer 410, and the connection part 460 is further provided on the extended PCB substrate 450.

Finally, the upper protective film 470 and the lower protective film 480 are provided on the upper electrode 430 and the PCB substrate 450.

The pressure sensor 500 provided as described above has a total thickness t of 5.5 to 2 mm to be applied to various fields such as a blood pressure measuring sensor, an intrusion detection sensor, a traffic analysis sensor, a car seat monitoring sensor, or a touch screen. can do.

While the present invention has been particularly shown and described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Such changes and modifications may belong to the present invention without departing from the scope of the present invention. Therefore, the scope of the present invention should be judged by the claims described below.

1A and 1B are cross-sectional views showing a cross section of a pressure sensitive element according to the present invention.

2 is a graph showing a change in resistivity of a piezoelectric sensitive element according to a change in pressure.

3 is a schematic diagram illustrating a tactile sensor according to a first embodiment of the present invention;

4 is a schematic diagram illustrating a tactile sensor according to a second embodiment of the present invention.

5 is a schematic diagram illustrating a pressure sensor according to a third embodiment of the present invention.

Claims (16)

A nonconductive elastic layer including conductive filler particles therein; And It is formed on both sides of the non-conductive elastic layer, and includes a flexible first electrode and a second electrode made of a material containing at least one of polyacetylene, polypyrole and polyaniline (polyaniline) , The conductive filler particles have a particle size of 10nm ~ 100㎛, have a shape of one or more of spherical, rod-shaped and needle-like, added in a ratio of 0.05 to 95% by weight relative to the total weight of the nonconductive elastic layer, When no external force is applied while a driving voltage is applied to the first electrode and the second electrode, the conductive filler particles are kept spaced apart from each other to insulate the first electrode from the second electrode. Keep it up, When an external force is applied to the first electrode or the second electrode, the non-conductive elastic layer is compressed in the direction in which the external force is applied, and an electric tunneling effect is generated between the conductive filler particles in the compressed region to generate the first electrode. Including the conductive filler particles having an arrangement such that a current flows between the first electrode and the second electrode, the current can also increase in proportion to the increase in the external force, The conductive filler particles are pressure-sensitive device, characterized in that added in a proportion of 10 to 50% by weight of the total weight of the conductive filler particles and the non-conductive elastic layer combined. The method of claim 1, The first electrode and the second electrode is a pressure sensitive element, characterized in that formed in each of a thickness of 0.1㎛ ~ 5mm. The method of claim 1, The first electrode and the second electrode Pressure sensitive element characterized in that formed in a three-dimensional shape including a film or polygonal pillar. delete The method of claim 1, The non-conductive elastic layer is a pressure-sensitive device, characterized in that formed to a thickness of 0.1㎛ ~ 5㎜. The method of claim 1, The non-conductive elastic layer is polyethylene (PE), high density polyethylene, low density PE, bakelite, neoprene, nylon (nylon), poly chloride Polyvinyl chloride (PVC), polystyrene (PS), polyacrylonitrile, ultra-high molecular weight polyethylene (UHMWPE), ethylene vinylacetate (ethylene vinylacetate (EVA), polyvinylbutyl A pressure sensitive device, characterized in that formed using any one selected from polyvinyl butyral (PVB), polypropylene (PP), polytetrafluoroethylene, and mixed materials thereof. delete delete The method of claim 1, The conductive filler particles are at least one selected from Ag, Au, Al, Cu, Pt, Ni, and carbon (Carbon-black) pressure sensitive device characterized in that. The method of claim 1, The driving voltage applied to the first electrode and the second electrode is a pressure sensitive element, characterized in that 1V ~ 100V. The method of claim 1, And a current of 1 mA to 100 A flowing between the first electrode and the second electrode by the electrical tunneling effect. It formed using the pressure sensitive element of Claim 1, The tactile sensor characterized by the above-mentioned. 13. The method of claim 12, The tactile sensor comprising the pressure sensitive element alone to measure the strength of the pressure. 13. The method of claim 12, And a plurality of pressure sensitive elements to measure an area to which pressure is applied. A pressure sensitive device according to claim 1, wherein the first electrode is provided as a front electrode to act as a receiving unit to which pressure is applied, and the second electrode is configured to grasp the position and size information of the pressure in real time. Pressure sensor, characterized in that formed in a plurality of patterns. 16. The method of claim 15, The pressure sensor is a pressure sensor, characterized in that applied to the blood pressure measurement sensor, intrusion detection sensor, traffic analysis sensor, car seat monitoring sensor or touch screen (Touch Screen).

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