WO2022255509A1 - Magnetorheological elastic body-based strain gauge capable of sensitivity control, and sensing apparatus comprising same - Google Patents

Abstract

The present invention provides a strain gauge capable of sensitivity control. The strain gauge according to the present invention comprises: a conductive thin film; and a support member for supporting at least one surface of the conductive thin film, and formed from a magnetorheological elastic body in which an elastic base contains magnetic particles. According to the present invention, by using the magnetorheological elastic body on the support member, for supporting the conductive thin film, and adjusting the strength of an electric field formed near the conductive thin film to adjust the rigidity of the support member, the sensitivity of the strain gauge may be variably adjusted.

Description

Magneto-rheological elastomer-based strain gauge capable of controlling sensitivity and sensing device including the same

The present invention relates to a strain gauge, and more particularly, to a strain gauge whose sensitivity can be controlled using a magnetorheological elastomer.

A strain gauge is a conductive thin film formed on the surface of a thin insulating substrate, and the mechanical deformation of the measured object is electrically measured by using the phenomenon in which the resistance value of the conductive thin film changes due to the tensile or compressive force applied to the measured object. It plays a role in converting into a signal.

Strain gauges are widely used in pressure sensors, load cells, torque sensors, acceleration sensors, and vibration sensors, and are attached to large structures (bridges, buildings, dams, retaining walls, etc.) It is also widely used to prevent safety accidents.

As such, since strain gauges are used in very diverse fields, when manufacturing strain gauges, they must be manufactured in consideration of sensitivity according to the purpose. For example, strain gauges used for low pressure measurement require higher sensitivity than those for high pressure measurement.

However, since the sensitivity of the strain gauge is determined by the physical properties or shapes of the substrate and the conductive pattern, it is difficult to adjust the sensitivity of the finished product ex post facto.

The present invention has been conceived against this background, and an object of the present invention is to provide a method for adjusting the sensitivity of a strain gauge.

In order to achieve this object, one aspect of the present invention, a conductive thin film; As for supporting at least one surface of the conductive thin film, a strain gauge including a support member made of a magnetorheological elastomer in which magnetic particles are contained in an elastic substrate is provided.

In the strain gauge according to one aspect of the present invention, the magnetorheological elastomer may be a porous magnetorheological elastomer in which a plurality of pores are formed inside an elastic substrate.

In addition, in the strain gage according to one aspect of the present invention, the conductive thin film may include a first conductive thin film and a second conductive thin film disposed vertically.

In addition, in the strain gauge according to one aspect of the present invention, the first conductive thin film and the second conductive thin film may be connected to the sensing device through separate wires.

In addition, in the strain gage according to one aspect of the present invention, the first conductive thin film and the second conductive thin film may be connected in parallel between two points connected to the sensing circuit.

In addition, in the strain gage according to an aspect of the present invention, the first conductive thin film and the second conductive thin film may be connected in series between two points connected to the sensing circuit.

Another aspect of the present invention is a strain gauge comprising a conductive thin film and a support member made of a magnetorheological elastomer in which magnetic particles are contained in an elastic substrate as supporting at least one surface of the conductive thin film; a sensing circuit connected to the strain gauge; a power supply unit supplying driving power to the sensing circuit; a sensing unit that detects changes in electrical characteristics of the sensing circuit; Provided is a sensing device including a control unit for controlling the output of a power supply unit in order to adjust the sensitivity of a strain gauge.

In the sensing device according to the present invention, the magnetorheological elastomer may be a porous magnetorheological elastomer in which a plurality of pores are formed inside the elastic substrate.

In addition, in the sensing device according to the present invention, the strain gauge includes a first conductive thin film and a second conductive thin film disposed vertically, and the support member surrounds the first conductive thin film and includes at least one of the second conductive thin film. One surface may be supported, the sensing circuit may be a Wheatstone bridge circuit, and the first conductive thin film and the second conductive thin film may be a first resistor and a second resistor constituting the Wheatstone bridge circuit, respectively.

According to the present invention, the sensitivity of the strain gauge can be adjusted in various ways by using a magnetorheological elastomer for a support member supporting the conductive thin film and controlling the stiffness of the support member by adjusting the strength of a magnetic field formed around the conductive thin film.

1 is a cross-sectional view of a strain gauge according to a first embodiment of the present invention;

Figure 2 is a cross-sectional view taken along line A-A' of Figure 1

Figure 3 is a cross-sectional view taken along line BB 'of Figure 2

4 is a schematic configuration diagram of a sensing device including a strain gauge according to a first embodiment of the present invention.

5 is a process flow chart showing a method of manufacturing a strain gauge according to a first embodiment of the present invention.

6 is a cross-sectional view of a strain gauge according to a second embodiment of the present invention

7 is a process flow chart showing a method of manufacturing a strain gauge according to a second embodiment of the present invention.

8 is a cross-sectional view of a strain gauge according to a third embodiment of the present invention

9 is a process flow chart showing a method of manufacturing a strain gauge according to a third embodiment of the present invention.

10 is a cross-sectional view of a strain gauge according to a fourth embodiment of the present invention

11 is a cross-sectional view of a strain gauge according to a fifth embodiment of the present invention

12 is a view showing a state in which strain gauges are arranged in multiple layers;

13 is a cross-sectional view taken along line C-C′ of FIG. 11

14 is a schematic configuration diagram of a sensing device including a strain gauge according to a fifth embodiment of the present invention.

15 is a process flow chart showing a method of manufacturing a strain gauge according to a fifth embodiment of the present invention.

16 is a process flow chart showing another manufacturing method of a strain gauge according to a fifth embodiment of the present invention.

17 is a cross-sectional view of a strain gauge according to a sixth embodiment of the present invention

18 to 20 are views showing various methods of connecting upper and lower conductive thin films in a strain gauge according to a sixth embodiment of the present invention, respectively.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

For reference, there are portions shown in dimensions or ratios different from those of the actual drawings in the drawings attached to this specification, but this is for convenience of explanation and understanding, so it should be noted in advance that the scope of the present invention should not be construed as being limited thereto. In addition, in the present specification, when one element is connected, coupled, or electrically connected to another element, not only when it is directly connected, coupled, or electrically connected to another element, but also between other elements in the middle. and indirectly connected, bonded or electrically connected. In addition, when one element is directly connected or combined with another element, it means that it is connected or combined without another element in the middle. In addition, the fact that a part includes a certain component means that it may further include other components without excluding other components unless otherwise stated. In addition, since expressions such as front, back, left, right, up, and down in this specification are relative concepts that may vary depending on the viewing position, the scope of the present invention is not necessarily limited to the corresponding expressions.

<First Embodiment>

The strain gauge 100 according to the first embodiment of the present invention is a conductive thin film having a predetermined pattern ( 120), a support member 110 made of a magnetorheological elastomer (MRE) material surrounding both sides of the conductive thin film 120, and the support member 110 in a state in which one end of each is coupled to both ends of the conductive thin film 120 (110) may include a first wire 131 and a second wire 132 extending to the outside.

The strain gage 100 must be flexibly deformed when the object to be measured is deformed while being attached to the object to be measured. To this end, the supporting member 110 is preferably made of a thin and flexible material.

The support member 110 of the strain gauge 100 according to the first embodiment of the present invention may be divided into a base 110a and a cover 110b. For example, the conductive thin film 120 may be coupled to the upper surface of the base 110a made of magnetorheological elastomer, and the cover 110b made of magnetorheological elastomer may be coupled to the upper surface of the conductive thin film 120 and the base 110a. have.

Magneto-rheological elastomer is one in which magnetic particles 114 are contained in an elastic base material 112 such as natural rubber or silicone rubber. It is relatively flexible in a state in which a magnetic field is not applied, but when a magnetic field is applied, the attractive force between the magnetic particles 114 It has the characteristic of changing elasticity and rigidity.

The magnetorheological elastomer may be prepared by mixing, for example, a silicone rubber material, carbonyl iron powder (CIP), silicone oil, etc., but the type of composition is not necessarily limited thereto.

As illustrated in FIG. 1, the conductive thin film 120 connects a plurality of grids 122 having an elongated strip shape and ends of adjacent grids 122 to each other, but connecting the entire grid 122 in series. The connection part 124, the first electrode pad 126a to which the first wire 131 is coupled, the second electrode pad 126b to which the second wire 132 is coupled, and the first electrode pad 126a A first feeding part 128a connecting one end of the entire grid 122 and a second feeding part 128b connecting the second electrode pad 126b and the other end of the entire grid 122 are included.

When deformation occurs in the object to be measured while the strain gauge 100 is attached to the object to be measured, the plurality of grids 122 having fine line widths are compressed or stretched, respectively, and the resistance value is changed. Deformation can be measured.

The material or thickness of the conductive thin film 120 and the length or width of the grid 122 are not limited to those shown in the drawings, and may be deformed and manufactured into various shapes depending on the purpose of the strain gauge 100.

However, in order for the strain gauge 100 to be flexibly deformed in response to the deformation of the object to be measured, it is preferable that the conductive thin film 120 is also made of a thin and flexible material.

For example, the conductive thin film 120 may be a metal-based material such as metal, carbon-coated metal, or a heterogeneous composite metal, or may be a carbon-based material such as carbon nanotube, graphene, graphite, or fullerene, or may be doped with It may be a ceramic material such as zinc oxide, indium tin oxide (ITO), copper oxide, or iron oxide, an organic material such as pentacene, a conductive polymer material, or other types of conductive material.

The conductive thin film 120 may be connected to the Wheatstone bridge circuit ( 210 in FIG. 4 ) through the first and second wires 131 and 132 and serve as a resistance of the Wheatstone bridge circuit 210 .

A method of forming the conductive thin film 120 on the upper surface of the base 110a is not particularly limited either.

As an example, a conductive material may be directly printed on the upper surface of the base 110a by a technique such as screen printing or inkjet printing, or a conductive material may be printed by a method such as chemical vapor deposition (CVD) or physical vapor deposition (PVD) using a mask. may be deposited to form the conductive thin film 120 .

As another example, after depositing or combining a conductive material on the entire upper surface of the base 110a, the conductive thin film 120 may be formed by photolithography.

As another example, a film or plate made of a conductive material may be processed into a predetermined pattern and attached to the upper surface of the base 110a.

FIG. 3 is a cross section taken along the line BB' of FIG. 1, illustrating a magnetic field formed around the grid 122 and the power supply portions 128a and 120b when current flows through the conductive thin film 120. .

In this way, when a magnetic field is formed around the grid 122 and the feeding parts 128a and 120b, an attractive force is generated between the magnetic particles 114 contained in the support member 110 made of magnetorheological elastomer, and this causes no magnetic field. Compared to the case, the support member 110 is hardened and rigidity is increased.

As the rigidity of the support member 110 increases, the range of change due to external force decreases, so it is more suitable for the purpose of measuring minute deformation of the object to be measured in detail.

Conversely, when the support member 110 is relatively flexible and its rigidity is low, it is more suitable for measuring the large deformation of the object to be measured because the range of change due to external force is large.

Accordingly, by adjusting the intensity of the magnetic field generated from the conductive thin film 120, the rigidity of the support member 110 can be appropriately changed, and through this, it is possible to adjust the sensitivity of the strain gauge 100 ex post facto.

Since the strength of the magnetic field is proportional to the strength of the current, the stiffness of the support member 110 can be changed by adjusting the strength of the current flowing through the conductive thin film 120 . In addition, the strength of the current flowing through the conductive thin film 120 may be controlled by adjusting the magnitude of the voltage applied across both ends of the conductive thin film 120 .

4 shows a schematic configuration diagram of a sensing device 200 including a strain gauge 100 according to a first embodiment of the present invention.

As illustrated in the drawing, the sensing device 200 includes a Wheatstone bridge circuit 210 in which the conductive thin film 120 of the strain gauge 100 and three resistors R1, R2, and R3 are connected in a rectangular shape, and a Wheatstone bridge circuit 210. The power supply unit 220 for applying the driving voltage Vin between a pair of nodes (eg, N1 and N3) facing each other of the stone bridge circuit 210, and the opposite side of the Wheatstone bridge circuit 210 A sensing unit 230 for detecting a voltage or current between another pair of nodes (eg, N2 and N4), a control unit 240 for controlling the operation of the sensing unit 230 and the power supply unit 220, and an input unit (250).

Although not shown in the drawing, the controller 240 may include a memory and a processor that executes a computer program stored in the memory.

The processor of the control unit 240 may calculate values such as pressure, displacement, torque, acceleration, frequency, etc. applied to the object to be measured using the voltage value or current value detected by the sensing unit 230 and an operation program stored in the memory. have.

The input unit 250 is a means for inputting necessary commands by the user, and buttons, keypads, touch pads, touch screens, toggle switches, and the like can be used without limitation. In an embodiment of the present invention, when a user inputs a sensitivity selection command through the input unit 250, the processor of the control unit 250 executes a sensitivity control program so that the driving voltage output from the power supply unit 220 corresponds to the input command. can be changed by

When the driving voltage of the power supply unit 220 changes, the strength of the current flowing through the conductive thin film 120 of the strain gauge 100 changes, and as a result, the strength of the magnetic field around the grid 122 and the power supply units 128a and 128b increases. Therefore, the rigidity of the support member 110 varies as the attraction between the magnetic particles 114 contained in the support member 110 changes.

As such, when the stiffness of the support member 110 changes, the sensitivity of the strain gauge 100 also changes.

Therefore, the sensitivity level of the strain gage 100 and the corresponding driving voltage are stored in a lookup table through a preliminary experiment, and when the user selects a sensitivity level through the input unit 250, the control unit 240 generates the lookup table The sensing device 200 can be configured to control the driving voltage of the power supply unit 220 with reference to , and through this, the user can adjust the sensitivity of the strain gauge 100 ex post facto as needed.

Hereinafter, the manufacturing method of the strain gauge 100 according to the first embodiment of the present invention will be described with reference to the flowchart of FIG. 5 .

First, a base 110a made of a magnetorheological elastomer is prepared, and a conductive thin film 120 is formed on an upper surface of the base 110a. As described above, the conductive thin film 120 may be formed on the upper surface of the base 110a by various methods such as photolithography, screen printing, inkjet printing, deposition, and coating. (See Fig. 5 (a), (b))

Subsequently, ends of the first and second wires 131 and 132 are respectively coupled to the first and second electrode pads 126a and 126b of the conductive thin film 120 with solder or the like. The other ends of the first and second wires 131 and 132 are coupled to the node of the Wheatstone bridge circuit 210, whereby the strain gauge 100 is one resistor among the four resistors constituting the Wheatstone bridge circuit 210. becomes (See Fig. 5 (c))

Subsequently, a cover 110b made of magnetorheological elastomer is prepared, and the cover 110b is coupled to the top of the conductive thin film 120 and the base 110a.

At this time, the cover 110b may be attached after applying an adhesive to the top of the conductive thin film 120 and the base 110a, or an intermediate product in which the conductive thin film 120 and the wires 131 and 132 are coupled to the base 110a. The cover 110b may be formed by putting the molten magneto-rheological elastomer in a mold. (See Fig. 5 (d))

<Second Embodiment>

As shown in the cross-sectional view of FIG. 6 , in the strain gauge 100a according to the second embodiment of the present invention, the conductive thin film 120 is formed on the upper surface of the thin insulating film 150, and the insulating film 150 and the conductive thin film 120 are formed. There is a difference in that the thin film 120 is surrounded by the base 110a and the cover 110b.

Referring to the process flow chart of FIG. 7 , in order to manufacture the strain gauge 100a according to the second embodiment of the present invention, first, a thin insulating film 150 is prepared and a conductive thin film 120 is formed on the upper surface thereof.

As described above, the conductive thin film 120 may be formed on the upper surface of the insulating film 150 by photolithography, screen printing, inkjet printing, deposition, coating, or the like. (See Fig. 7 (a))

Subsequently, the insulating film 150 on which the conductive thin film 120 is formed is coupled to the upper surface of the magnetorheological elastomer base 110a using an adhesive or the like, and the first and second electrode pads 126a of the conductive thin film 120 , 126b) is coupled to one end of the first and second wires 131 and 132, respectively. (See Fig. 7 (b))

Subsequently, a cover 110b made of magnetorheological elastomer is prepared, and the cover 110b is coupled to the top of the conductive thin film 120, the insulating film 150, and the base 110a.

Even in this case, the cover 110b may be attached after applying the adhesive on the upper portion of the conductive thin film 120 and the base 110a, or the middle where the conductive thin film 120 and the wires 131 and 132 are coupled to the base 110a. The cover 110b may be formed by placing the product in a mold and injecting a melted magnetorheological elastomer. (See Fig. 7 (c))

<Third Embodiment>

As shown in the cross-sectional view of FIG. 8, the strain gauge 100b according to the third embodiment of the present invention is the same as the second embodiment in that the insulating film 150 on which the conductive thin film 120 is formed is used, but the strain gauge 100b according to the third embodiment is supported. There is a difference from the second embodiment in that the member 110 is not divided into the base 110a and the cover 110b but is integrally formed.

Referring to the process flow chart of FIG. 9 , in order to manufacture the strain gauge 100b according to the third embodiment of the present invention, first, a thin insulating film 150 is prepared and a conductive thin film 120 is formed on the upper surface thereof. (See Fig. 9 (a))

Subsequently, when the insulating film 150 on which the conductive thin film 120 is formed is put into a mold and a magnetorheological elastomer melt is injected, the support member 110 surrounding both the upper and lower surfaces of the conductive thin film 120 and the insulating film 150 can be formed at once. (See Fig. 9 (b))

<Fourth Embodiment>

In the strain gauge 100c according to the fourth embodiment of the present invention, as shown in the cross-sectional view of FIG. 10, the support member 160 surrounding the conductive thin film 120 includes a base 160a made of a porous magnetorheological elastomer and a cover. 160b is different from the first embodiment, and the basic structure is the same as that of the strain gauge 100 according to the first embodiment.

The porous magnetorheological elastomer is prepared by mixing, for example, silicone rubber material, silicone oil, carbonyl iron powder, ethanol, etc. in a predetermined weight ratio, and going through a homogenization and curing process, while ethanol evaporates during the curing process. A large number of pores are formed inside.

As shown in the figure, when the support member 160 surrounding the conductive thin film 120 is formed of a porous magnetorheological elastomer in which a large number of pores 116 are formed inside the elastic substrate 112, a magnetorheological elastomer without pores can be obtained. Since flexibility and elasticity are improved compared to the case of using the strain gauge, it is possible to manufacture a strain gauge more suitable for large deformation.

<Fifth Embodiment>

As illustrated in the cross-sectional view of FIG. 11 and FIG. 12, the strain gauge 100d according to the fifth embodiment of the present invention includes a first conductive thin film 120a and a second conductive thin film ( 120b) is different from the previous embodiment in that it is formed in multiple layers.

In this way, when the first and second conductive thin films 120a and 120b are formed in multiple layers, as illustrated in FIG. 13, which is a cross-sectional view taken along line C-C' of FIG. 11, the upper and lower grids 122 and Since current flows in both of the front parts 128a and 128n, the strength of the magnetic field greatly increases in the area where the upper and lower magnetic fields overlap, and the strength of the magnetic field greatly decreases in the area where the magnetic fields cancel out.

Therefore, in the strain gauge 100d according to the fifth embodiment of the present invention, the shape of each grid 122 as well as the vertical spacing between the first and second conductive thin films 120a and 120b or the upper grid 122 and the lower grid By appropriately adjusting the degree of horizontal misalignment of (122), the strength of the magnetic field can be adjusted in a much more diverse manner than in the case of using the single-layer conductive thin film 120.

Therefore, in the strain gauge 100d according to the fifth embodiment of the present invention, the rigidity of the support member 110 can be adjusted more diversely than in the case of using the single-layer conductive thin film 120 .

Meanwhile, the first conductive thin film 120a and the second conductive thin film 120b included in the strain gauge 100d according to the fifth embodiment of the present invention, as shown in the sensing device 200a of FIG. It may also be used as a resistance of the stone bridge circuit 210.

As such, it is known that the accuracy of the sensing device 200a increases as the number of strain gauges used in the Wheatstone bridge circuit 210 increases.

When the strain gage 100d includes three or more conductive thin films 120 , three or four conductive thin films may be used as resistors of the Wheatstone bridge circuit 210 .

A method of manufacturing the strain gauge 100d according to the fifth embodiment of the present invention is not particularly limited.

Hereinafter, the manufacturing method according to the first embodiment will be described with reference to FIG. 15 .

First, a first conductive thin film 120a is formed on the base 110a made of magnetorheological elastomer, and the first and second wires 131a and 132a are coupled. (See Fig. 15 (a), (b))

Next, an intermediate layer 110c made of a magnetorheological elastomer is formed on the base 110a and the first conductive thin film 120a. At this time, the intermediate layer 110c may be attached after applying an adhesive on the base 110a and the first conductive thin film 120a, and the first conductive thin film 120a and the wires 131 and 132 may be attached to the base 110a. The intermediate layer 110c may be formed by putting the combined intermediate product into a mold and injecting a melted magnetorheological elastomer. (See Fig. 15 (c))

Subsequently, a second conductive thin film 120b is formed on the upper surface of the intermediate layer 110c, and the first and second wires 131b and 132b are coupled. (See Fig. 15 (d))

Subsequently, a cover 110b made of a magnetorheological elastomer is formed on the middle layer 110c and the second conductive thin film 120b. Even in this case, the cover 110b may be attached after applying an adhesive on the upper portion of the second conductive thin film 120b and the intermediate layer 110c, or the cover 110b may be formed by putting the intermediate product in a mold and injecting a magneto-rheological elastomer melt. can also form. (See Fig. 15 (e))

Next, a manufacturing method according to the second embodiment will be described with reference to FIG. 16 .

First, a first intermediate product in which the first conductive thin film 120a is formed on the first insulating film 150a and the first and second wires 131a and 132a are combined, and the second conductive thin film is formed on the second insulating film 150b. (120b) is formed and the second intermediate product is prepared by combining the first and second wires (131b, 132b). (See Fig. 16 (a))

Subsequently, the support member 110 is formed at once by putting the first intermediate product and the second intermediate product into a mold and injecting a melted magnetorheological elastomer. (See Fig. 16 (b))

Meanwhile, although it is shown that two conductive thin films 120a and 120b are arranged vertically in FIGS. 11 and 12, it is not limited thereto, so three or more conductive thin films may be arranged vertically.

In addition, FIGS. 11 and 12 show that the first conductive thin film 120a and the second conductive thin film 120b are disposed in the same direction while being vertically spaced apart, but are not limited thereto. For example, the first conductive thin film 120a and the second conductive thin film 120b may be disposed in directions that cross each other when viewed from above.

In addition, although it is shown in FIG. 13 that the directions of currents flowing through the first conductive thin film 120a and the second conductive thin film 120b are the same, it is not limited thereto, and currents may flow in opposite directions.

<Sixth Embodiment>

As illustrated in the cross-sectional view of FIG. 17 , the strain gauge 100e according to the sixth embodiment of the present invention includes a first conductive thin film 120a and a second conductive thin film 120b inside the support member 110 . It is the same as that of the fifth embodiment in that it is formed of multiple layers.

However, in the strain gauge 100e according to the sixth embodiment of the present invention, the first conductive thin film 120a and the second conductive thin film 120b are electrically connected to each other by the connecting portion 180 to form a Wheatstone bridge circuit 210 ) is different from the fifth embodiment in that it serves as a single resistor.

The first conductive thin film 120a and the second conductive thin film 120b may be connected in various ways.

As an example, as shown in FIG. 18, the first electrode pad 126a of the first conductive thin film 120a and the first electrode pad 126a of the second conductive thin film 120b located thereon are connected to each other. 180, and connect the second electrode pad 126b of the first conductive thin film 120a and the second electrode pad 126b of the second conductive thin film 120b positioned above the second electrode pad 126b to the connecting portion 180. can connect

In this state, if the first and second wires 131 and 132 are respectively connected to the first and second electrode pads 126a and 126b of the second conductive thin film 120b, the first conductive thin film 120a and the second conductive thin film ( 120b) are resistors connected in parallel with each other.

As another example, as shown in FIG. 19, the second electrode pad 126b of the first conductive thin film 120a and the first electrode pad 126a of the second conductive thin film 120b positioned diagonally above the second electrode pad 126a are Connected to the connection part 180, the first wire 131 and the second electrode pad 126a of the first conductive thin film 120a and the second electrode pad 126b of the second conductive thin film 120b, respectively. Wires 132 can be connected.

When connected in this way, the first conductive thin film 120a and the second conductive thin film 120b become resistors connected in series with each other, and the grid 122 of the first conductive thin film 120a and the grid of the second conductive thin film 120b In 122, currents in the same direction flow.

As another example, as shown in FIG. 20 , the first electrode pad 126a of the first conductive thin film 120a and the first electrode pad 126a of the second conductive thin film 120b positioned above the first electrode pad 126a are Connected to the connection part 180, the first wire 131 and the second electrode pad 126b of the first conductive thin film 120a and the second electrode pad 126b of the second conductive thin film 120b, respectively. Wires 132 can be connected.

When connected in this way, the first conductive thin film 120a and the second conductive thin film 120b become resistors connected in series with each other, and the grid 122 of the first conductive thin film 120a and the grid of the second conductive thin film 120b In 122, currents in opposite directions flow.

In the above, preferred embodiments of the present invention have been described, but the present invention is not limited to the above-described embodiments and may be modified or modified in various forms in a specific application process.

For example, it has been described above that the support member 110 made of a magnetorheological elastomer surrounds both sides of the conductive thin film 120, but is not limited thereto.

For example, one side of the conductive thin film 120 is bonded to and supported by a base 110a made of magnetorheological elastomer, and a protective layer is formed on the other side of the conductive thin film 120 using an insulating material other than magnetorheological elastomer. may be

As such, the present invention can be practiced in various forms, modified or modified, and if the modified or modified embodiments also include the technical spirit of the present invention disclosed in the claims to be described later, it is natural that they fall within the scope of the present invention. .

[Description of code]

100: strain gauge 110: support member

110a: base 110b: cover 110c: intermediate layer

112: elastic substrate 114: magnetic particles 116: pores

120: conductive thin film 122: grid 124: connection portion

126a, 126b: first and second electrode pads 128a, 128b: first and second power supply units

131, 132: first and second wires 150: insulating film

160: support member 160a: base 160b: cover

180: connection part 200: detection device 210: Wheatstone bridge circuit

220: power supply unit 230: detection unit 240: control unit

250: input unit

Claims (9)

1. conductive thin film;

   A support member made of a magneto-rheological elastomer containing magnetic particles in an elastic substrate for supporting at least one surface of a conductive thin film.

   A strain gauge containing
2. According to claim 1,

   The magnetorheological elastomer is a strain gauge, characterized in that a porous magnetorheological elastomer in which a plurality of pores are formed inside the elastic substrate
3. According to claim 1,

   The strain gauge characterized in that the conductive thin film includes a first conductive thin film and a second conductive thin film disposed vertically
4. According to claim 3,

   The strain gauge characterized in that the first conductive thin film and the second conductive thin film are connected to the sensing circuit through separate wires, respectively.
5. According to claim 3,

   The first conductive thin film and the second conductive thin film are connected in parallel to each other between two points connected to the sensing circuit, characterized in that the strain gauge
6. According to claim 3,

   The first conductive thin film and the second conductive thin film are connected in series between two points connected to the sensing circuit, characterized in that the strain gauge
7. a strain gauge comprising a conductive thin film and a supporting member supporting at least one surface of the conductive thin film and made of a magnetorheological elastomer in which magnetic particles are contained in an elastic substrate;

   a sensing circuit connected to the strain gauge;

   a power supply unit supplying driving power to the sensing circuit;

   a sensing unit that detects changes in electrical characteristics of the sensing circuit;

   A control unit that controls the output of the power supply unit to adjust the rigidity of the support member of the strain gauge.

   a sensing device comprising
8. According to claim 7,

   The magnetorheological elastomer is a sensing device, characterized in that a porous magnetorheological elastomer in which a plurality of pores are formed inside the elastic substrate
9. According to claim 7,

   The strain gauge includes a first conductive thin film and a second conductive thin film disposed vertically,

   The support member supports at least one surface of the second conductive thin film in a state surrounding the first conductive thin film,

   The sensing circuit is a Wheatstone bridge circuit,

   The first conductive thin film and the second conductive thin film are a first resistor and a second resistor constituting the Wheatstone bridge circuit, respectively.

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