WO2016197429A1

WO2016197429A1 - Resistance strain gage and resistance strain sensor

Info

Publication number: WO2016197429A1
Application number: PCT/CN2015/083718
Authority: WO
Inventors: 于喆; 于玫; 杨灿灿; 张隼
Original assignee: 中国科学院深圳先进技术研究院; 深圳三思创新电子科技有限公司
Priority date: 2015-06-09
Filing date: 2015-07-10
Publication date: 2016-12-15
Also published as: CN104880206B; CN104880206A

Abstract

Disclosed are a resistance strain gage (1000) and resistance strain sensor. The resistance strain gage (1000) comprises a flexible substrate (10) and a resistance strain sensing unit (20) attached to the flexible substrate (10), wherein two ends of the resistance strain sensing unit (20) are provided with extraction electrodes (22, 23). The resistance strain sensor comprises the resistance strain gage (1000) and a component under test (2000). The resistance strain gage (1000) and the component under test (2000) are deformed together under the action of a physical quantity. By measuring a variation value of a resistance of the resistance strain gage in the process of deformation to measure the magnitude of the physical quantity applied on the component under test (2000), a maximum strain of 200% and its corresponding physical quantity can be measured with a high integration level, good extendability and easy implementation.

Description

Resistance strain gauge and resistance strain sensor

Priority statement

This application claims the priority of the Chinese invention patent filed on June 9, 2015, the application number is CN201510312473.X, the invention is entitled "resistance strain gauge and resistance strain sensor", and all the contents of the invention patent are hereby incorporated. .

Technical field

The invention relates to the field of sensor technology, in particular to a resistance strain sensor for realizing a large-scale strain measurement range, in particular to a resistance strain gauge and a resistance strain sensor.

Background technique

Traditional strain gauges and strain gauge sensors are commonly used to study or verify the stress and deformation of certain components such as machinery, bridges, and buildings under working conditions. With the development of electronics and information technology, strain gauge sensor applications have gradually expanded to various aspects, and correspondingly, higher requirements have been put forward for variable sensing technology. In particular, biomedical devices, wearable electronic devices and the like applied to the human body have higher requirements for performance indexes such as flexibility of the sensor and large-scale measurement range. Strain sensors mainly include fiber strain sensors, piezoelectric material strain sensors, and resistance strain sensors.

Among them, the biggest problem of fiber strain sensor is that it requires a large number of equipment to assist it, the arrangement is difficult, and the cost is high, which restricts its application in miniaturization, low cost, portable equipment; Sensors are difficult to meet the requirements for sensor softness and large-scale measurement range due to the mechanical electrical properties and interface bonding of their materials.

At present, the strain sensing element commonly used is a resistance strain sensor based on the resistance strain effect, that is, the member to be tested is deformed by the measured physical quantity, and the resistance strain gauge attached thereto is deformed together, and the resistance strain gauge is deformed. The deformation is then converted into a change in resistance value, so that various physical quantities such as tension, pressure, torque, displacement, acceleration, and temperature can be measured. The functional layer materials of the existing resistance strain gauges mainly include metal and semiconductor, and the metal strain gauges have a wire type, a foil type, and a film type. Due to the poor flexibility of metal materials, the biggest disadvantage is that the sensitivity is low and the measurement range is small. Generally, only about a few percent of the strain value can be measured. For example, the strain value of platinum is ±8%, and the tungsten has about ±0.3%. Strain range, copper-nickel Gold has a range of strain values of ± 5%. The main disadvantages of semiconductor strain gauges are that they are affected by temperature, the preparation process is complicated, the preparation cost is high, and the deformation amount capable of reversible expansion and contraction is only about a few percent of the strain value. Therefore, conventional metal and semiconductor materials are greatly limited in their use for strain sensors, and in particular, it is difficult to measure large-scale strains.

In order to achieve softness and large-scale strain measurement, an attempt has been made to use an emerging material as a functional layer of a strain gauge. For example, Chinese Patent Publication No. CN101598529 discloses an elastic fabric coated with conductive particles or a mixture of fibers and an elastomer matrix. The strain gauge sensor has a maximum strain value of 50%. However, it is only used to measure the in-plane unidirectional strain, and its processing technology is complicated. If it is necessary to clean and dry the elastic fabric substrate, it is necessary to cure the conductive particles or fibers to remove the water or other solvent present therein. In particular, it is difficult to achieve micro- and nano-scale fine processing (small, miniaturized for sensors), integration (integrated with other electronic devices and systems), and poor scalability.

Further, as disclosed in Chinese Patent Publication No. CN104142118, a resistance strain sensor having a plurality of CNT films composed of the carbon nanotubes (CNT) fibers as a functional layer material having a strain value of more than 80% is disclosed. However, when deformed in the orientation direction of the non-CNT fibers, the linearity of the resistance change measured by the sensor is not high. Similarly, it is difficult to achieve micro- and nano-scale fine processing (small, miniaturized sensors), integration (integrated with other electronic devices and systems), and poor scalability.

Therefore, there is a need in the art to develop a resistance strain sensor capable of performing fine processing on a micrometer and a nanometer scale, and having good integration and expandability.

Summary of the invention

The invention provides a resistance strain gauge and a resistance strain sensor. A conductive strain film (ie, a resistance strain sensing layer) having a micrometer and a nano gap is attached to a flexible substrate to form a resistance strain gauge, and then the resistance strain gauge is attached. On the member to be tested, when the measured member is physically deformed, the resistance value of the conductive film changes, thereby obtaining a physical quantity change of the member to be tested, which solves the problem that the maximum strain amount measured by the resistance strain gauge in the prior art is small. Low integration and poor scalability.

The resistance strain gauge of the present invention comprises a flexible substrate and a resistance strain sensing unit, wherein the resistance strain sensing unit is attached to the flexible substrate. The resistance strain sensing unit further includes: a resistance strain sensing layer for changing a corresponding resistance value according to a magnitude of the generated deformation; a first electrode electrically connected to one end of the resistance strain sensing layer; and a second electrode And electrically connected to the other end of the resistance strain sensing layer.

The resistance strain sensor of the present invention includes a resistance strain gauge and a member to be tested, and the resistance strain gauge is attached to a surface of the member to be tested, and the member to be tested is deformed together by a physical quantity, and the measurement is performed. The amount of change in the resistance value of the resistance strain gauge during the deformation to measure the physical quantity acting on the member to be tested.

The invention provides a resistance strain gauge and a resistance strain sensor. A conductive film (ie, a resistance strain sensing layer) having a micrometer and a nano gap is attached to a flexible substrate to form a resistance strain gauge, and then the resistance strain is formed. The sheet adheres to the member to be tested. When the member to be tested is physically deformed, the strain gauge will deform along with the member to be tested, that is, the conductive film will be stretched, and the resistance value of the conductive film will change. The physical quantity (including tensile force, pressure, torque, displacement, acceleration, temperature, etc.) of the member to be tested can be obtained by the amount of change in the resistance value of the conductive film; since the conductive film is a stretchable gold having a micron and nano gap structure on the surface Made of film, the maximum strain can reach 200%; in addition, a plurality of strain gauges can be attached to the tested member to simultaneously monitor strain in different directions and different parts. In addition, the resistance strain gauge of the invention has the advantages of simple structure, high integration degree and good expandability.

It is to be understood that the foregoing general description of the invention,

DRAWINGS

The accompanying drawings, which are set forth in the claims

1 is a plan view of a first embodiment of a resistance strain gauge according to an embodiment of the present invention;

2 is a top view of a second embodiment of a resistance strain gauge according to an embodiment of the present invention;

Figure 3 is a cross-sectional view of the resistance strain gauge shown in Figure 1 taken along the line A-A;

Figure 4 is a cross-sectional view of the resistance strain gauge shown in Figure 1 taken along line B-B;

Figure 5 is a cross-sectional view of the resistance strain gauge shown in Figure 2 taken along the line C-C;

Figure 6 is a cross-sectional view of the resistance strain gauge shown in Figure 2 taken along the line D-D;

FIG. 7 is a top view of Embodiment 3 of a resistance strain gauge according to an embodiment of the present invention; FIG.

FIG. 8 is a top view of a fourth embodiment of a resistance strain gauge according to an embodiment of the present invention; FIG.

Figure 9 is a cross-sectional view of the resistance strain gauge shown in Figure 7 taken along the line E-E;

Figure 10 is a cross-sectional view of the resistance strain gauge shown in Figure 8 taken along the line F-F;

FIG. 11 is a schematic diagram of Embodiment 1 of a resistance strain sensor according to an embodiment of the present invention. view;

12 is a top view of a second embodiment of a resistance strain sensor according to an embodiment of the present invention;

FIG. 13 is a top plan view of Embodiment 3 of a resistance strain sensor according to an embodiment of the present invention; FIG.

14 is a top plan view of Embodiment 4 of a resistance strain sensor according to an embodiment of the present invention;

15 is a top plan view of Embodiment 5 of a resistance strain sensor according to an embodiment of the present invention;

16 is a schematic diagram of an integrated application of a resistance strain sensor and other sensors according to an embodiment of the present invention;

17 is a topographical view of a resistive strain sensing layer of a resistance strain gauge before stretching according to an embodiment of the present invention;

Figure 18 is a topographical view showing the stretching of the electrical resistance strain sensing layer of the strain gauge of Figure 17;

FIG. 19 is a diagram showing relationship between resistance change and strain of a resistive strain sensing layer of a strain gauge according to an embodiment of the present invention; FIG.

20 is a schematic diagram of a gap distribution of a nano crack before stretching of a resistive strain sensing layer of a strain gauge according to an embodiment of the present invention;

FIG. 21 is a schematic diagram showing a micro-nano crack gap distribution when a resistive strain sensing layer of a resistance strain gauge is stretched according to an embodiment of the present invention; FIG.

FIG. 22 is a specific application example of a resistance strain gauge having a tiled substrate according to an embodiment of the present invention;

FIG. 23 is a specific application example of a resistance strain gauge having a columnar structure substrate according to an embodiment of the present invention.

Description of the symbols:

10 flexible substrate 20 first resistance strain sensing unit

21 resistance strain sensing layer 22 first electrode

23 second electrode

30 protective layer

40 second resistance strain sensing unit 50 third resistance strain sensing unit

60 fourth resistance strain sensing unit 70 fifth resistance strain sensing unit

80 sixth resistance strain sensing unit 90 seventh resistance strain sensing unit

α first angle β second angle

γ third angle δ fourth angle

1000 resistance strain gauge 2000 tested component

detailed description

The spirit and scope of the present invention will be apparent from the following description of the embodiments of the invention, The invention may be modified and modified by the teachings of the present invention without departing from the spirit and scope of the invention.

The illustrative embodiments of the invention and the description thereof are intended to illustrate the invention, but are not intended to limit the invention. In addition, the same or similar reference numerals or components are used in the drawings and the embodiments to represent the same or similar parts.

The terms "first", "second", etc., as used herein, are not specifically intended to refer to the order or order, and are not intended to limit the invention, only to distinguish between elements or operations described in the same technical terms. .

Regarding the directional terms used herein, for example, up, down, left, right, front or back, etc., only refer to the directions of the drawings. Therefore, the directional terminology used is used to illustrate that it is not intended to limit the creation.

As used herein, "including", "including", "having", "containing", and the like are meant to be open-ended, meaning to include but not limited to.

With respect to "and/or", "and/or" as used herein, includes any or all combinations of the recited.

The terms "substantially", "about" and the like, as used herein, are used to modify any quantity or error that may vary slightly, but such minor variations or errors do not alter the nature. In general, the range of minor variations or errors modified by such terms may be 20% in some embodiments, 10% in some embodiments, or 5% or other values in some embodiments. It should be understood by those skilled in the art that the aforementioned numerical values may be adjusted according to actual needs, and are not limited thereto.

Certain terms used to describe the present application are discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in the description of the application.

1 is a top view of a first embodiment of a resistance strain gauge according to an embodiment of the present invention. As shown in FIG. 1, the resistance strain gauge includes a flexible substrate 10 and a first resistance strain sensing unit 20, wherein The resistance strain sensing unit 20 further includes a resistance strain sensing layer 21, a first electrode 22, and a second electrode 23. The first resistance strain sensing unit 20 is attached to the flexible substrate 10 and deformed together with the flexible substrate 10, and the resistance strain sensing layer 21 is configured to change its corresponding resistance value according to the magnitude of the deformation generated; The electrode 22 is electrically connected to one end of the resistance strain sensing layer 21; the second electrode 23 is electrically connected to the other end of the resistance strain sensing layer 21. In other specific embodiments of the present invention, the first resistive strain sensing unit 20 is a conductive film having a micron and nanogap structure and still maintaining electrical conduction under a large deformation. The conductive film may be made of one of gold, platinum, copper and graphene. The conductive properties of gold, platinum, copper and graphene are very good, and gold, platinum and copper have micron and nano gap structures. The graphene film is a good measure of the amount of change in resistance produced by strain.

Referring to FIG. 1, a first resistance strain sensing unit 20 is attached to the flexible substrate 10 to deform together with the flexible substrate 10 under the measured physical quantity. The resistance strain sensing layer 21, the first electrode 22, and the second electrode 23 are made of a stretchable conductive film having a micron and nano gap structure on the surface, and in the present application, a micro-nano process (MEMS, Micro-Electro- The mechanical strain system 21, the first electrode 22 and the second electrode 23 are processed on the flexible substrate 10, and the invention is not limited thereto. In a specific embodiment of the invention, the first electrode 22 And the size of the second electrode 23 is 1.5×1.5 mm ² , the size of the resistance strain sensing layer 21 is 0.5×10 mm ² , and the thickness of the gold film is about 50 nm, the gold film can be maintained at 150% one-dimensional deformation. Electrically conductive and with multiple cycles of fatigue life at maximum elongation. The electrical resistance strain gauge provided by the embodiment of the invention is realized by adopting a novel micrometer and nano gap structure. When the conductive thin film is deformed together with the flexible substrate 10, the micron and nano gap structure of the conductive thin film can be well released. Local stress, which does not cause large penetration cracks inside the film, thus ensuring film continuity and electrical continuity; the resistance strain gauge and the flexible substrate 10 constitute a resistance strain gauge capable of measuring a large-scale deformation range, The strain gauge can measure strains up to 200%.

2 is a top view of a second embodiment of a resistance strain gauge according to an embodiment of the present invention. As shown in FIG. 2, the resistance strain gauge further includes a protective layer 30, wherein the protective layer 30 covers the resistance strain transmission. On the sensation layer 21, a protective layer 30 is used to protect the resistance strain sensing layer 21.

Referring to FIG. 2, the resistive strain sensing layer 21 is covered with a protective layer 30, which prevents foreign matter from entering the resistance strain sensing layer 21, and also prevents foreign objects from damaging the resistance strain sensing layer 21, and prolongs The service life of the resistance strain sensing layer 21 also ensures the accuracy of the measurement.

In a specific embodiment of the invention, the protective layer 30 has elasticity, and the material of the protective layer 30 is rubber or polydimethylsiloxane. The invention is not limited thereto, as long as it can provide a protective effect and does not affect the physical measurement of the material.

3 is a cross-sectional view of the resistance strain gauge shown in FIG. 1 along the AA direction, as shown in FIG. 3, the first resistance strain gauge 20 is attached to the flexible substrate 10, and the first resistance strain sensing unit 20 (in the figure) Not further indicated) further comprising a resistive strain sensing layer 21, a first electrode 22 and a second electrode 23, the flexible substrate 10 being deformed by a physical quantity, since the first resistive strain sensing unit 20 is attached to the flexible substrate 10, A resistive strain sensing unit 20 is deformed together with the flexible substrate 10.

4 is a cross-sectional view of the resistance strain gauge shown in FIG. 1 taken along the line BB, as shown in FIG. 4, the first resistance strain sensing unit 20 is attached to the flexible substrate 10, as various portions have been described above, It will not be described in detail to save space.

5 is a cross-sectional view of the resistance strain gauge shown in FIG. 2 in the CC direction, and FIG. 5 is different from FIG. 3 in that the resistance strain sensing layer 21 is further covered with a protective layer 30 to protect the resistance strain sensing. The layer 21 also prevents foreign objects from damaging the resistance strain sensing layer 21, prolonging the service life of the resistance strain sensing layer 21, and also ensuring measurement accuracy.

6 is a cross-sectional view of the resistance strain gauge shown in FIG. 2 in the DD direction. As shown in FIG. 6, the protective layer 30 also covers both side walls of the resistance strain sensing layer 21, thereby being better protected. The resistance strain sensing layer 21 is not limited to the invention.

In a specific embodiment of the present invention, the resistance strain gauge further includes a bottom layer (not shown), wherein the underlayer is disposed between the flexible substrate 10 and the first resistance strain sensing unit 20 The underlayer is mainly used to enhance adhesion between the flexible substrate 10 and the first resistance strain sensing unit 20.

The underlayer is disposed between the flexible substrate 10 and the first resistance strain sensing unit 20, and the underlayer can enhance the conductive film (ie, the gold film, including: the resistance strain sensing layer 21, the first electrode 22 And the adhesion of the second electrode 23) to the flexible substrate 10, the material of the underlayer may be one of titanium, chromium, and copper, and the invention is not limited thereto. The underlayer effectively enhances the adhesion of the conductive film and the flexible substrate 10. When the flexible substrate 10 is deformed by the physical quantity, the conductive film is deformed together with the flexible substrate 10, further ensuring measurement accuracy.

In a specific embodiment of the present invention, the protective layer 30 can be coated on the underlayer at the same time, thereby preventing the difference The object enters the gap between the bottom layer and the flexible substrate 10 and the first resistance strain sensing unit 20, thereby ensuring the adhesion between the underlayer and the flexible substrate 10 and the first resistance strain sensing unit 20. The present invention does not This is limited.

FIG. 7 is a top view of a third embodiment of a resistance strain gauge according to an embodiment of the present invention, and FIG. 7 is different from that of FIG. 1 in that the flexible substrate 10 is a columnar structure, and the first resistance strain sensing unit 20 is attached to the The flexible substrate 10 is deformed together with the flexible substrate 10 under the measured physical quantity, and the other is exactly the same as the resistance strain gauge shown in FIG. 1, and will not be described again here to save space.

FIG. 8 is a top view of a fourth embodiment of a resistance strain gauge according to an embodiment of the present invention, and FIG. 8 is different from FIG. 7 in that the resistance strain gauge further includes a protective layer 30, wherein the protective layer 30 covers On the resistance strain sensing layer 21, a protective layer 30 is used to protect the resistance strain sensing layer 21.

9 is a cross-sectional view of the resistance strain gauge shown in FIG. 7 in the EE direction. As shown in FIG. 9, the flexible substrate 10 has a columnar structure, and the first resistance strain sensing unit 20 is attached to the flexibility of the columnar structure. On the substrate 10, the first resistance strain sensing unit 20 also exhibits a fan ring structure; in addition, the first resistance strain sensing unit 20 may also exhibit a ring structure, which is not limited thereto.

A specific application implementation of the first resistive strain sensing unit 20 attached to the planar substrate, and a specific embodiment in which the first resistive strain sensing unit 20 is attached to the flexible substrate 10 having a columnar structure will be described later.

10 is a cross-sectional view of the resistance strain gauge shown in FIG. 8 in the FF direction, and FIG. 10 is different from FIG. 8 in that the resistance strain gauge further includes a protective layer 30, wherein the protective layer 30 covers the resistor On the strain sensing layer 21, a protective layer 30 is used to protect the resistance strain sensing layer 21. In Fig. 10, the protective layer 30 covers the entire columnar flexible substrate 10, and can provide a good protection.

In a specific embodiment of the present invention, the resistance strain gauge further includes a bottom layer, wherein the underlayer is disposed between the flexible substrate 10 and the first resistance strain sensing unit 20, and the bottom layer is used for reinforcement Adhesion between the flexible substrate 10 and the first electrical resistance strain sensing unit 20.

11 is a top view of a first embodiment of a resistance strain sensor according to an embodiment of the present invention. As shown in FIG. 11, the resistance strain sensor includes: a strain gauge 1000 and a member to be tested 2000, wherein The resistance strain gauge 1000 is attached to the surface of the member to be tested 2000, and is deformed together with the measured physical quantity of the member to be tested 2000 by measuring the resistance value of the strain gauge 1000 during the deformation process. The physical quantity acting on the member to be tested 2000 is measured. In a specific embodiment of the invention, the physical quantity may be tension, pressure, torque, displacement, acceleration or temperature. degree.

Referring to FIG. 11, the resistance strain sensor provided by the present invention has the advantages of simple structure, reliable principle, and low cost, and can realize micrometer size and can flexibly detect an example with small space.

12 is a top view of a second embodiment of a resistance strain sensor according to an embodiment of the present invention, and FIG. 12 is different from FIG. 11 in that the flexible substrate 10 is a columnar structure, and the strain gauge 1000 is adhered to the same. The surface of the member to be tested 2000 is deformed together with the member to be tested 2000 by a physical quantity (including tensile force, pressure, torque, displacement, acceleration, temperature, etc.).

13 is a top view of a third embodiment of a resistance strain sensor according to an embodiment of the present invention. As shown in FIG. 13, the resistance strain gauge further includes a second resistance strain sensing unit 40, and a second resistance strain sensing. The unit 40 is vertically disposed with the first resistance strain sensing unit 20, and the second resistance strain sensing unit 40 is attached to the flexible substrate 10.

Referring to FIG. 13, the materials of the first resistance strain sensing unit 20 and the second resistance strain sensing unit 40 are fabricated by a micro-nano processing process, and the first resistance strain sensing unit 20 and the second resistance strain sensing unit 40 are The materials used may be different. For example, the first resistance strain sensing unit 20 is made of gold, and the second resistance strain sensing unit 40 is made of graphene, and the first resistance strain sensing unit 20 and the second resistance strain can be realized. The vertical cross arrangement of the sensing unit 40 enables simultaneous detection of strains in the same part and in different directions, and the application is flexible, expandable, and more competitive in practical applications. The resistance strain sensor shown in FIG. 13 is only one specific embodiment of the present invention. The first resistance strain sensing unit 20 is horizontally disposed, and the second resistance strain sensing unit 40 is vertically disposed only in a relative manner. The sensing unit 20 is disposed vertically, and the second resistive strain sensing unit 40 is horizontally disposed. In other specific embodiments, the first resistive strain sensing unit 20 and the second resistive strain sensing unit 40 can also be configured according to actual measurement requirements. The first resistance strain sensing unit 20 and the second resistance strain sensing unit 40 are presented in a non-vertical layout, for example, a scissors-like layout or a parallel layout, etc., and the invention is not limited thereto.

Referring again to FIG. 13, an insulation layer (not shown) is disposed between the first resistance strain sensing unit 20 and the second resistance strain sensing unit 40. The arrangement of the insulating layer can prevent the mutual influence between the first resistance strain sensing unit 20 and the second resistance strain sensing unit 40, so that the measurement result is more accurate. Of course, in a specific embodiment of the present invention, when the lengths of the first resistance strain sensing unit 20 and the second resistance strain sensing unit 40 are long, only the first resistance strain sensing unit 20 is measured. Or when the stress of the second resistance strain sensing unit 40 is received, since the area of the intersection portion is relatively small, the influence of the overlapping portion on the measurement result can be neglected, so that the insulating layer can be omitted to achieve This saves and prepares simple results.

14 is a plan view of a fourth embodiment of a resistance strain sensor according to an embodiment of the present invention, and FIG. 15 is a top view of a fifth embodiment of a resistance strain sensor according to an embodiment of the present invention, as shown in FIGS. 14 and 15 The resistance strain gauge further includes a third resistance strain sensing unit 50, and/or a fourth resistance strain sensing unit 60, and/or a fifth resistance strain sensing unit 70, and/or a sixth resistance strain transmission. Sense unit 80 and/or seventh resistance strain sensing unit 90, wherein the third resistance strain sensing unit 50 is arranged side by side in parallel with the first resistance strain sensing unit 20; the fourth resistance strain sensing unit 60 and the The first resistance strain sensing unit 20 is arranged at a first angle α; the fifth resistance strain sensing unit 70 and the first resistance strain sensing unit 20 are arranged at a second angle β; the sixth resistance strain The sensing unit 80 and the first resistance strain sensing unit 20 form a third angle γ layout; the seventh resistance strain sensing unit 90 and the first resistance strain sensing unit 20 form a fourth angle δ Layout; wherein the third resistor The variable sensing unit 50, and/or the fourth resistive strain sensing unit 60, and/or the fifth resistive strain sensing unit 70, and/or the sixth resistive strain sensing unit 80, and/or Or the seventh resistance strain sensing unit 90 is attached to the flexible substrate 10. The above-mentioned resistance strain sensing unit is made by a micro-nano processing technology, and the materials used may be the same or different, and the invention is not limited thereto.

Referring to FIG. 15, the first resistance strain sensing unit 20 and the third resistance strain sensing unit 50 are disposed in parallel, a fourth resistance strain sensing unit 60, and/or a fifth resistance strain sensing unit 70, and/or a sixth The resistance strain sensing unit 80 and/or the seventh resistance strain sensing unit 90 are disposed around the first resistance strain sensing unit 20 and the third resistance strain sensing unit 50, and can simultaneously detect different parts and strains in different directions. The utility model has the advantages of wide application, flexible application and strong expandability. In a specific embodiment of the present invention, only the fifth resistance strain sensing unit 70, the sixth resistance strain sensing unit 80 and the seventh resistance strain sensing unit 90 may be included therein. One or more of the present inventions are not limited thereto.

The present invention does not specifically define the magnitude relationship between the first angle α, and/or the second angle β, and/or the third angle γ and/or the fourth angle δ, The fourth resistance strain sensing unit 60, and/or the fifth resistance strain sensing unit 70, and/or the sixth resistance strain sensing unit 80 and/or the seventh resistance strain sensing unit 90 surround a layout of the first resistance strain sensing unit 20 and the third resistance strain sensing unit 50, the first angle α, and/or the second angle β, and/or the third angle γ And/or the fourth angle δ is an angle facing the first resistance strain sensing unit 20 and the third resistance strain sensing unit 50, for example, in an embodiment of the invention, the An angle α, the second angle β, the third angle γ, and the fourth angle δ are different from each other; in another embodiment of the present invention, the first angle α, the second The angle β, the third angle γ, and the fourth angle δ are the same in magnitude. For example, the first angle α, the second angle β, the third angle γ, and the fourth angle δ are both 45 degrees, or the first angle α and the fourth angle δ are 45 degrees, the second angle β and the third angle γ are 60 degrees. In addition, the present invention does not limit the number of the resistance strain sensing units. The number of the resistance strain sensing units may be appropriately increased or decreased on the premise that the object of the invention is satisfied. For example, the third resistance strain sensing unit 50 may not be provided. That is, only the fourth resistance strain sensing unit 60, and/or the fifth resistance strain sensing unit 70, and/or the sixth resistance strain sensing unit 80 and/or the seventh resistance strain The sensing unit 90 surrounds the layout of the first resistance strain sensing unit 20 (as shown in FIG. 14), and may further be provided with two resistance strain gauges, respectively, with the first resistance strain sensing unit 20 and the third resistance strain. The sensing unit 50 is vertically disposed, and the invention is not limited thereto.

In a specific embodiment of the present invention, if the first resistance strain sensing unit 20 overlaps with other resistance strain sensing units (as shown in FIG. 15), then the first resistance strain sensing unit 20 And/or the fourth resistance strain sensing unit 60, and/or the fifth resistance strain sensing unit 70, and/or the sixth resistance strain sensing unit 80, and/or the seventh An insulating layer is disposed between the resistance strain sensing units 90.

FIG. 16 is a schematic diagram of an integrated application of a resistance strain sensor and other sensors according to an embodiment of the present invention. As shown in FIG. 16 , the resistance strain sensing layer material of the resistance strain gauge is fabricated by using a micro-nano processing technology (MEMS). Therefore, the size can be flexibly designed and processed, the nanometer-sized structure can be realized at a minimum, and it is easy to integrate with other sensors, electronic devices and systems. The shape, size, number and arrangement of the resistance strain gauges can be adjusted according to practical application requirements.

17 is a topographical view of a resistive strain sensing layer of a resistive strain gauge according to an embodiment of the present invention; FIG. 18 is a resistive strain sensing layer of a resistive strain gauge of FIG. a surface topography diagram in stretching; as shown in FIGS. 17 to 18, the first electrode 22, the second electrode 23, and the resistance strain sensing layer are made of a stretchable gold film having a micron and nano gap structure on the surface, The bottom layer is titanium. Figures 17 to 18 are the scanning electron micrographs (SEM) of the gold film before stretching, stretching (ε=100%) and tensile reduction. The gold film can be seen from the figure. The micro- and nano-gap structure of the surface, which can release local stress well when the film is stretched. Figure 17 shows the original nano-gap structure of the conductive film. From Figure 17, the nano-gap is in an arbitrary distribution state. When the conductive film is subjected to stress stretching, the part The nano-gap will expand and merge into a micron-gap with a width of micron (as shown in Figure 18) to release the local stress generated during stretching without creating large penetration cracks inside the film. The stretchability is ensured without causing large penetration cracks inside the film, thereby ensuring its stretchability.

FIG. 19 is a diagram showing relationship between resistance change and strain of a resistive strain sensing layer of a strain gauge according to an embodiment of the present invention. The sizes of the first electrode 22 and the second electrode 23 of the resistive strain sensing unit are both 1.5×. 1.5mm ² , the size of the resistance strain sensing layer is 0.5×10mm ² , and the thickness of the gold film is about 50nm. The film can maintain electrical conduction under 150% one-dimensional deformation and has more at maximum stretching rate. The fatigue life of the secondary cycle. As shown in FIG. 19, y=ax, y=ln(R/R ₀ ), x=ε, a=2.86178, correlation coefficient r=0.9963, and the resistance strain gauge measures the resistance strain sensing layer after cyclic stretching 100 times. Correspondence diagram of the change in resistance and the strain causing the change. In Fig. 19, y = ln(R/R ₀ ), x = ε, where R ₀ is the initial resistance value, R is the resistance value at the time of strain, and ε is the dependent variable; as can be seen from Fig. 19, y and x correspond A good linear relationship: y = ax, to ensure the accuracy of physical measurements (including tensile force, pressure, torque, displacement, acceleration or temperature) when the strain gage is subjected to large strains. The initial value of the resistance R ₀ and the linear coefficient a are determined by the size and structure of the resistive strain sensing layer, but the resistance values vary similarly with strain. It can be seen from FIG. 19 that the resistance strain gauge has the characteristics of high response speed, high sensitivity, and good linearity. The maximum deformation range that the strain gage can achieve under the condition of maintaining electrical conduction can be adjusted by changing the size of the resistance strain sensing layer.

FIG. 20 is a schematic diagram showing the distribution of the nano crack gap before the tensile strain of the resistance strain sensing layer of the electrical resistance strain gauge according to the embodiment of the present invention; FIG. 21 is a schematic diagram of the resistance strain sensing layer of the electrical resistance strain gauge according to the embodiment of the present invention; Schematic diagram of the micro-nano crack gap distribution during stretching, as shown in FIG. 20 and FIG. 21, FIG. 20 is a schematic diagram of a plurality of nano-crack gap structures on the surface of the conductive film before stretching, and FIG. 21 is when the conductive film is subjected to stress stretching. Part of the nano-gap is partially merged into a micro-gap to release the local stress generated in the stretching without causing large penetration cracks inside the film, which ensures the stretchability of the resistance strain sensing layer.

FIG. 22 is a specific application example of a resistance strain gauge having a tile-shaped substrate according to an embodiment of the present invention; FIG. 23 is a specific application example of a resistance strain gauge having a columnar structure substrate according to an embodiment of the present invention; As shown in Fig. 22 and Fig. 23, two kinds of structural diagrams of the resistance strain gauge are given, that is, a tiled structure and a columnar structure, and two different structures can be reasonably used according to practical applications. Figures 22 and 23 show two specific operational examples of two strain gauges in the biomedical field. Figure 22 The resistance strain gauge for the flat structure is attached to the knee joint of the knee joint damaged patient or the hemiplegia patient in the form of a knee guard. When the patient performs rehabilitation training, the patient is guided by real-time detection of the range of motion at the knee joint of the patient. Rehabilitation training, so as to prevent the patient from over-exciting the amount of exercise before the consciousness is fully restored, causing secondary damage to the knee joint. Figure 23 is a columnar structure of the electrical resistance strain gauge in the form of a bracelet attached to the patient's wrist for pulse testing, this wear method is more easy to operate than the flat-state resistive strain sensor, without the use of adhesives, The advantage of higher gas permeability and more beautiful appearance.

The invention provides a resistance strain gauge and a resistance strain sensor. A conductive film (ie, a resistance strain sensing layer) having a micrometer and a nano gap is attached to a flexible substrate to form a resistance strain gauge, and then the resistance strain is formed. The sheet adheres to the member to be tested. When the member to be tested is physically deformed, the strain gauge will deform along with the member to be tested, that is, the conductive film will be stretched, and the resistance value of the conductive film will change. The physical quantity (including tensile force, pressure, torque, displacement, acceleration, temperature, etc.) of the member to be tested can be obtained by the amount of change in the resistance value of the conductive film; since the conductive film is stretchable conductive having a micron and nano gap structure on the surface The film is made up to a maximum strain of 200%; in addition, a plurality of strain gauges can be adhered to the member to be tested, and strains in different directions and different parts can be simultaneously monitored. The strain gauge of the present invention has a simple structure and low cost. , high integration, good scalability and so on.

The present invention has at least the following beneficial effects:

The invention proposes a new resistance strain gauge which can be deformed in a large scale. The conductive film of the strain gauge is realized by a novel micron and nano gap structure; when the conductive film is deformed together with the flexible substrate, the micron of the conductive film The nano-gap structure can release local stress well without causing large penetration cracks inside the film, thus ensuring its stretchability.

The invention attaches a resistance strain gauge to the member to be tested, and constitutes a resistance strain sensor capable of measuring a large-scale deformation range, and the resistance strain sensor can measure a strain of at most 200%.

The conductive film of the resistance strain gauge of the invention is made by micro-nano processing technology, and the resistance strain gauge can be processed into micrometer or nanometer size, which can realize integration of multiple resistance strain gauges, can simultaneously detect strains of different parts and different directions, and can Integrate with other sensors, electronics and systems.

The resistance strain gauge and the resistance strain sensor of the invention have fatigue life of multiple cycles, and the conductive film material can be processed on different elastic base materials such as silica gel, fabric, etc., which are less restricted by the substrate (backing material), and the functional layer is The base material together has a very high flexibility, can be bent and deformed, can meet the complex body surface morphology and dynamic deformation requirements of the organism, can measure the deformation of the tissue, can be applied in fields such as biomedicine, has wide application, and is more practical in practical applications. Competitive.

The resistance strain gauge and the resistance strain sensor of the invention are simple in preparation, reliable in principle, low in cost, and the prepared resistance strain sensor is transparent, and the materials used have absolute safety and environmental friendliness to the human body.

The resistance strain gauge is prepared by micro-nano processing technology, and can be expanded into multiple channels, which can realize integration of multiple sensing units, and can simultaneously monitor strains in different directions and different parts.

The resistance strain gauge is small in size, light in weight, simple in structure, convenient in use, fast in response, and has little influence on the working state and stress distribution of the device under test, and can be used for both static measurement and dynamic measurement.

The resistance strain sensor of the invention has high sensitivity, short response time and long fatigue life.

The above is only the exemplary embodiments of the present invention, and any equivalent changes and modifications made by those skilled in the art should fall within the scope of protection of the present invention without departing from the spirit and scope of the present invention. .

Claims

A resistance strain gauge, characterized in that the resistance strain gauge comprises:

a flexible substrate (10);

a first resistance strain sensing unit (20) attached to the flexible substrate (10), the first resistance strain sensing unit (20) further comprising:

a resistance strain sensing layer (21) for changing a corresponding resistance value according to the magnitude of the deformation generated;

a first electrode (22) electrically connected to one end of the resistance strain sensing layer (21);

A second electrode (23) is electrically connected to the other end of the resistance strain sensing layer (21).
The resistance strain gauge according to claim 1, wherein the resistance strain gauge further comprises:

A protective layer (30) overlying the resistive strain sensing layer (21) for protecting the resistive strain sensing layer (21).
The resistance strain gauge according to claim 2, wherein the protective layer (30) has elasticity, and the material used is rubber or polydimethylsiloxane.
The electrical resistance strain gauge according to claim 1, wherein said flexible substrate (10) has elasticity, and the material used is rubber or polydimethylsiloxane.
The resistance strain gauge according to claim 1, wherein the flexible substrate (10) has a planar structure or a columnar structure.
The resistance strain gauge according to claim 1, wherein the resistance strain sensing layer (21) is a conductive film that remains electrically conductive under a large deformation, and the conductive film is made of gold or platinum. One of copper, graphene.
The resistance strain gauge according to claim 6, wherein said electroconductive thin film has a micron and nanogap structure.
The resistance strain gauge according to claim 1, wherein the resistance strain gauge further comprises:

A second resistive strain sensing unit (40) disposed perpendicularly to the first resistive strain sensing unit (20) is attached to the flexible substrate (10).
The resistance strain gauge according to claim 8, wherein an insulating layer is interposed between said first resistance strain sensing unit (20) and said second resistance strain sensing unit (40).
The resistance strain gauge according to claim 1, wherein the resistance strain gauge further comprises:

a third resistive strain sensing unit (50) arranged side by side with the first resistive strain sensing unit (20).
The resistance strain gauge according to claim 1, wherein the resistance strain gauge further comprises:

a fourth resistance strain sensing unit (60) arranged at a first angle (α) with the first resistance strain sensing unit (20);

And/or a fifth resistive strain sensing unit (70) disposed at a second angle (β) between the first resistive strain sensing unit (20);

And/or a sixth resistance strain sensing unit (80) disposed at a third angle (γ) between the first resistive strain sensing unit (20);

And/or a seventh resistance strain sensing unit (90) arranged at a fourth angle (δ) between the first resistance strain sensing unit (20);

The third resistance strain sensing unit (50), the fourth resistance strain sensing unit (60), the fifth resistance strain sensing unit (70), and the sixth resistance strain sensing unit (80) The seventh resistance strain sensing unit (90) is attached to the flexible substrate (10).
The resistance strain gauge according to claim 11, wherein said fourth resistance strain sensing unit (60), and/or said fifth resistance strain sensing unit (70), and/or said A six-resistance strain sensing unit (80) and/or the seventh resistance strain sensing unit (90) is disposed around the first resistive strain sensing unit (20).
The resistance strain gauge according to claim 10, wherein said first resistance strain sensing unit (20), and/or said fourth resistance strain sensing unit (60), and/or said An insulating layer is provided between the five-resistance strain sensing unit (70), and/or the sixth resistance strain sensing unit (80), and/or the seventh resistance strain sensing unit (90).
A resistance strain sensor comprising: the resistance strain gauge (1000) according to any one of claims 1 to 13 and a member to be tested (2000),

Attaching the strain gauge (1000) to the surface of the member to be tested (2000), and deforming together with the member (2000) under the influence of a physical quantity, by measuring the strain gauge during the deformation process The amount of change in the resistance value of (1000) measures the physical quantity acting on the member (2000) to be tested.
The resistance strain gauge sensor of claim 14 wherein said physical quantity comprises: tensile force, and/or pressure, and/or torque, and/or displacement, acceleration, and/or temperature.