CN210811072U - Tensile Stress Sensors and Bend Sensing Devices - Google Patents

Abstract

The utility model relates to a tensile stress sensor, comprising a first conductive fiber and a second conductive fiber. The second conductive fiber is wound on the first conductive fiber to form at least one of the first conductive fiber and the second conductive fiber. The contact part between the two conductive fibers; the area of the contact part changes with the state of the second conductive fiber being stretched by an external force. The tensile stress sensor has the advantages of small size, large enough response, real-time monitoring, compatibility with existing textile technology and convenient wearing. The utility model also relates to a bending sensing device, comprising at least one of the tensile stress sensor and a flexible substrate, the tensile stress sensor is arranged on the flexible substrate, and the second conductive fibers are subjected to The flexible substrate stretches under the action of bending. The bending sensing device has the advantages of being washable, not easy to fall off, resisting movement interference, high resolution, high sensitivity and being compatible with the existing textile technology.

Description

Tensile Stress Sensors and Bend Sensing Devices

technical field

The utility model relates to the field of stress sensing, in particular to a tensile stress sensor and a bending sensing device.

Background technique

Stress sensors have important applications in many aspects, ranging from national defense engineering to civilian medical care. Stress sensing can be seen everywhere. With the development of society, we have higher and higher requirements for stress sensing accuracy.

The current stress sensing technology is mainly based on capacitive, piezoelectric, resistive or triboelectric effect, etc. No matter what kind of sensor, most of them use pressure-sensitive rubber, organic semiconductor materials, conductive polymers, etc. Materials that are sensitive and will produce corresponding responses, however, these materials have obvious disadvantages, that is, they are bulky and the response is not large enough, which will bring inconvenience to stress measurement.

In recent years, several types of flexible stress sensor technologies have been reported by related technicians: the carbon fiber-based plain cotton fabric (CPCF) reported by Mingchao Zhang et al., which experimentally showed its superior performance in detecting human motion; Chunya Wang et al. The carbonized silk fabric (CSFS) material can detect both large and subtle human motion, which is suitable for the fabrication of superelastic and highly sensitive strain sensors. Although these reported materials have excellent performance, they still have the following problems: the sensitivity of the sensor is not high enough, and it often requires a very large amount of deformation to produce detectable changes (such as resistance, capacitance, etc.).

For the above reasons, the development of a stress sensor with a small volume and a relatively large response with only a small amount of deformation has become an urgent need for the development of smart wearable electronic products.

Utility model content

Based on this, the purpose of the present invention is to provide a tensile stress sensor, which has the advantages of small size, sufficiently large response, real-time monitoring, compatible with existing textile technology and convenient to wear.

The technical scheme adopted by the utility model is as follows:

A tensile stress sensor includes a first conductive fiber and a second conductive fiber, the second conductive fiber is wound on the first conductive fiber to form at least one between the first conductive fiber and the second conductive fiber. The contact position between the two; from the radial section of the first conductive fiber at the contact position, the angle between the two central axes of the second conductive fiber respectively located on both sides of the contact position is less than 90°; The area of the contact portion varies with the state of the second conductive fiber being stretched by an external force.

The working principle of the tensile stress sensor is as follows: when the second conductive fiber is stretched by an external force, the greater the external force, the larger the area of the contact portion between the first conductive fiber and the second conductive fiber. The smaller the resistance between the first conductive fiber and the second conductive fiber at the contact part; and the smaller the external force, the smaller the area of the contact part between the first conductive fiber and the second conductive fiber, the smaller the first conductive fiber and the second conductive fiber. The resistance between the contact parts of the two conductive fibers is greater; thus, the magnitude of the tensile stress of the second conductive fibers can be reflected by measuring the change of the resistance, thereby realizing the induction and detection of the tensile stress.

The tensile stress sensor of the utility model is made of two conductive fibers, and has a simple structure. Since the diameter of the conductive fibers can be small, flexible and woven, the volume of the tensile stress sensor can be very large. Small, easy to use, and fully compatible with existing textile technology and textile materials, solving the problem of existing wearable devices that can only be "wearable" but not "wearable", and at the same time, the tensile stress The resistance between the two conductive fibers in the sensor has a sufficiently large response to tensile stress, and only a small amount of deformation is required to generate a detectable resistance response. Therefore, the tensile stress sensor has high sensitivity and can be monitored in real time.

The tensile stress sensor can be used for monitoring the range of motion of the limb, and when the limb returns to the original state, the resistance of the sensor can also return to the original state, with good recovery and high stability.

Further, when the second conductive fiber is not stretched by external force, the area of the contact part is the smallest. At this time, the first conductive fiber and the second conductive fiber are kept taut to prevent the contact part from disappearing, which is conducive to timely detection. to the emergence of stress.

Further, the two ends of the first conductive fiber are fixed, and the two ends of the second conductive fiber are fixed, so that the first conductive fiber and the second conductive fiber are always maintained in a taut state to avoid relative displacement between the two. cause the contact site to disappear.

Further, the first conductive fiber is arranged straight, and its two ends are fixed respectively; the second conductive fiber is wound on the first conductive fiber and the two ends are folded in half to form a first conductive fiber and a second conductive fiber. At the contact part between the conductive fibers, the two ends of the second conductive fibers are fixed together; the first conductive fibers and the second conductive fibers are perpendicular to each other to form a T-shaped structure. Experiments have verified that in this configuration, after the second conductive fiber is stretched or bent for many times, the relative displacement between the first conductive fiber and the second conductive fiber is not easy to occur, and the initial resistance is stable and unchanged, so that the measurement error is smaller.

Further, the first conductive fibers and the second conductive fibers are respectively provided with fluffy structures at the contact positions; the fluffy structures include a plurality of conductive fiber filaments, and there are a plurality of gaps between the plurality of conductive fiber filaments. technical effect

Further, the first conductive fiber is made of carbon, metal or conductive polymer material; the second conductive fiber is made of carbon, metal or conductive polymer material.

Another object of the present invention is to provide a bending sensor device, which includes the tensile stress sensor described in any one of the above and a flexible substrate, the tensile stress sensor is arranged on the flexible substrate, Both ends of the first conductive fibers and both ends of the second conductive fibers are fixed on the flexible substrate; the second conductive fibers are stretched by the bending of the flexible substrate.

The working principle of the bending sensing device is as follows: when the flexible substrate is bent and the second conductive fibers are stretched, the greater the degree of bending of the flexible substrate, the greater the stretching effect on the second conductive fibers, the greater the effect of the first conductive fibers. The larger the area of the contact part between the fiber and the second conductive fiber is, the smaller the resistance between the first conductive fiber and the second conductive fiber is at the contact part; and the smaller the degree of bending of the flexible substrate, the less resistance to the second conductive fiber. The smaller the stretching effect of the conductive fiber, the smaller the area of the contact part between the first conductive fiber and the second conductive fiber, the greater the resistance between the first conductive fiber and the second conductive fiber at the contact part; by Therefore, by measuring the change of the resistance, the bending state of the flexible substrate can be reflected, so as to realize the induction and detection of the bending state.

The bending sensing device of the present invention adopts the above-mentioned tensile stress sensor as a sensing unit, and adopts a flexible substrate to carry the tensile stress sensor and implement bending, which can be used for monitoring the bending amplitude of limb movement, such as using It is used to measure the bending angle of the joint in the range of 0-180°, and when the limb returns to the original state, its resistance can also return to the original state, with good recovery and high stability.

The bending sensing device of the utility model has the advantages of being cleanable, not easy to fall off, anti-motion interference, high resolution, high sensitivity and compatible with the existing textile technology.

Further, the bending sensing device includes at least two tension-type stress sensors connected in series or in parallel.

Preferably, the tensile stress sensors are connected in series with each other; in each tensile stress sensor, the first conductive fiber is arranged straight, and its two ends are respectively fixed; the second conductive fiber is wound around the The first conductive fiber is folded in half to form a contact portion between the first conductive fiber and the second conductive fiber, and the two ends of the second conductive fiber are fixed together; the first conductive fiber and the second conductive fiber are fixed together. The second conductive fibers are perpendicular to each other to form a T-shaped structure.

It has been verified by experiments that after the second conductive fiber is stretched or bent for many times, the relative displacement between the first conductive fiber and the second conductive fiber is not easy for the tensile stress sensor with this configuration, and its initial resistance is stable and unchanged, so that the The measurement error of the bending angle is smaller; at the same time, the tensile stress sensors connected in series can obtain a larger resistance change, thereby obtaining a stronger response signal on the circuit and improving the detection sensitivity.

Further, the flexible substrate is a flexible circuit board, which is beneficial to the integration and miniaturization of the device.

For better understanding and implementation, the present utility model is described in detail below with reference to the accompanying drawings.

Description of drawings

1 is a schematic diagram of the basic structure of the tensile stress sensor of the present invention;

Fig. 2 is the A-A direction schematic diagram of Fig. 1;

3 is a schematic diagram of a first conductive fiber or a second conductive fiber with a fluffy structure;

4 is a schematic diagram of a tensile stress sensor with a fluffy structure of the present invention;

5 is a schematic diagram of the basic structure of the bending sensing device of the present invention;

6 is a schematic structural diagram of the tensile stress sensor of Example 1;

7 is a schematic structural diagram of the tensile stress sensor of Example 2;

8 is a schematic structural diagram of the tensile stress sensor of Example 3;

9 is a schematic structural diagram of the tensile stress sensor of Example 4;

10 is a schematic structural diagram of the bending sensing device of Embodiment 5;

FIG. 11 is a schematic diagram of the bending of the bending sensing device of Embodiment 5;

12 is a resistance-bending angle relationship diagram of the bending sensing device of Example 5;

13 is a test result diagram of a bending cycle experiment of the bending sensing device of Example 5;

14 is a schematic structural diagram of an implementation manner of the bending sensing device of Example 6;

15 is a schematic structural diagram of another implementation manner of the bending sensing device of Example 6;

16 is a side view of the bending sensing device of Example 6;

17 is a schematic structural diagram of the bending sensing device of Embodiment 7;

Fig. 18 is a schematic diagram of bending of the bending sensing device according to the seventh embodiment, wherein Fig. 18(a) is a schematic diagram of the bending sensing device when the bending angle is 0°, and Fig. 18(b) is the bending sensing device A schematic diagram of the device when the bending angle is 60°, and FIG. 18(c) is a schematic diagram of the bending sensing device when the bending angle is 90°;

19 is a schematic structural diagram of the bending sensing device of Embodiment 8;

FIG. 20 is a schematic structural diagram of the bending sensing device of Embodiment 9, wherein FIG. 20( a ) is a schematic structural diagram viewed from the front of the flexible substrate, and FIG. 20( b ) is a structural schematic diagram viewed from the back of the flexible substrate 20e .

Detailed ways

Please refer to FIG. 1 , which is a schematic diagram of the basic structure of the tensile stress sensor of the present invention.

The tensile stress sensor 10 of the present invention includes a first conductive fiber 11 and a second conductive fiber 12. The second conductive fiber 12 is wound around the first conductive fiber 11 to form at least one of the first conductive fibers. The contact part 13 between the fiber 11 and the second conductive fiber 12, FIG. 1 shows that the second conductive fiber 12 is wound around the first conductive fiber 11 to form a contact part 13, but the number of the contact part 13 is not limited to one , which can be two or more. Moreover, the area of the contact portion 13 changes with the state of the second conductive fiber 12 being stretched by an external force, and the direction of the arrow in FIG. 1 represents the stretching direction.

As shown in FIG. 2 , viewed from the radial cross section of the first conductive fiber 11 at each contact site 13 , the second conductive fiber 12 is located between the two central axes on both sides of each contact site 13 , respectively. The angle α is less than 90°.

The working principle of the tensile stress sensor 10 is as follows: when the second conductive fiber 12 is stretched by an external force (the direction of the arrow in FIG. 1 indicates the stretching direction), the greater the external force, the greater the force between the first conductive fiber 11 and the first conductive fiber 11 . The larger the area of the contact portion 13 between the second conductive fibers 12, the smaller the resistance between the first conductive fiber 11 and the second conductive fiber 12 at the contact portion 13; The smaller the area of the contact portion 13 between the second conductive fibers 12, the greater the resistance between the first conductive fiber 11 and the second conductive fiber 12 at the contact portion 13; thus, by measuring the change in the resistance can reflect The magnitude of the tensile stress of the second conductive fibers 12, so as to realize the induction and detection of the tensile stress.

In order to detect the occurrence of tensile stress in time, in an embodiment, when the second conductive fiber 12 is not stretched by external force, the first conductive fiber 11 and the second conductive fiber 12 are also kept as tight as possible to prevent any The contact portion 13 disappears, and the area of the contact portion 13 is minimized.

In order to keep the first conductive fiber 11 and the second conductive fiber 12 in a taut state all the time, and to avoid the relative displacement between the two leading to the disappearance of the contact part 13, in one embodiment, the two parts of the first conductive fiber 11 The ends are fixed, and the two ends of the second conductive fibers 12 are also fixed.

In order to further improve the sensitivity of induction, as a preferred embodiment, as shown in Figures 3-4, the first conductive fibers 11 and the second conductive fibers 12 are respectively provided with fluffy structures 14 at the contact parts 13; The fluffy structure 14 includes a plurality of conductive fiber filaments 140, and there are a plurality of gaps between the plurality of conductive fiber filaments 140, and the number of the conductive fiber filaments 140 is preferably not less than ten; The conductive fiber filaments 140 in the fluffy structure 14 of the fiber 11 and the conductive fiber filaments 140 in the fluffy structure 14 of the second conductive fiber 12 are in contact with each other to form a plurality of conductive channels, and the total area of contact between them is the the area of the contact site 13;

Therefore, although the state of the second conductive fibers 12 being stretched by an external force only changes slightly (the direction of the arrow in FIG. 4 indicates the stretching direction), the number of voids between the conductive fiber filaments 140 in the fluffy structure 14 can also vary with The number of conductive channels formed also changes, that is, the area of the contact portion 13 changes accordingly, which is beneficial for the resistance generation between the contact portion 13 of the first conductive fiber 11 and the second conductive fiber 12 to be controlled. detected changes;

Therefore, using the first conductive fiber 11 and the second conductive fiber 12 with the fluffy structure 14 respectively to form the tensile stress sensor can make the area of the contact part 13 change with the change of the tensile state of the second conductive fiber 12 It is more significant, which is beneficial to improve the sensitivity of induction and realize the effective induction and detection of tiny tensile stress.

Specifically, as shown in FIG. 3 , the conductive fiber filaments 140 of the first conductive fiber 11 are arranged along the axial direction of the first conductive fiber 11 , and both ends thereof are connected to the first conductive fiber 11 ; the second conductive fiber The conductive fiber filaments 140 in 12 are arranged along the axial direction of the second conductive fiber 12, and both ends thereof are connected to the second conductive fiber 12; however, the direction of the conductive fiber filaments 140 is not limited by this, for example, it can also be It is perpendicular to different directions such as the side surface of the first conductive fiber 11 or the second conductive fiber 12 where it is located.

Specifically, the first conductive fibers 11 are carbon, metal or conductive polymer materials, the second conductive fibers 12 are carbon, metal or conductive polymer materials, and the conductive fiber filaments 140 in the fluffy structure 14 are carbon , metal or conductive polymer materials. In addition, the lengths and diameters of the first conductive fibers 11 and the second conductive fibers 12 are not limited, depending on actual needs.

In the tensile stress sensor of the present invention, there are various ways of winding the second conductive fibers around the first conductive fibers, and there are also various ways of arranging the first conductive fibers and the second conductive fibers, including The configurations described in the following Embodiments 1-4, but the tensile stress sensor of the present invention is not limited to the configurations of the Embodiments 1-4.

Please refer to FIG. 5 , which is a schematic diagram of the basic structure of the bending sensing device of the present invention.

The bending sensor device B of the present invention includes at least one tensile stress sensor 10 and a flexible substrate 20, the tensile stress sensor 10 is arranged on the flexible substrate 20, and the first conductive fiber Both ends of 11 and both ends of the second conductive fiber 12 are fixed on the flexible substrate 20; the second conductive fiber 12 is stretched by the bending of the flexible substrate 20, and the arrow in FIG. 5 indicates the bending state.

The working principle of the bending sensing device B is as follows: when the flexible substrate 20 is bent and the second conductive fibers 12 are stretched (the arrow in FIG. 5 indicates the bending state), the greater the degree of bending of the flexible substrate 20, the more effective it is. The greater the stretching effect of the second conductive fibers 12 is, the larger the area of the contact portion 13 between the first conductive fibers 11 and the second conductive fibers 12 is. The smaller the resistance between 13; and the smaller the degree of bending of the flexible substrate 20, the smaller the stretching effect on the second conductive fiber 12, the contact part 13 between the first conductive fiber 11 and the second conductive fiber 12. The smaller the area, the greater the resistance between the first conductive fiber 11 and the second conductive fiber 12 at the contact portion 13; thus, by measuring the change of the resistance, the bending state of the flexible substrate 20 can be reflected, and the bending state is realized. sensing and detection.

In order to detect the bending state of each part of the flexible substrate 20, in one embodiment, the bending sensing device B includes at least two tensile stress sensors 10 connected in series or in parallel. The resistances between the first conductive fibers 11 and the second conductive fibers 12 in each tensile stress sensor 10 are connected in series by using a connection circuit, and the above-mentioned parallel connection refers to using a connection circuit to connect the first conductive fibers 11 in each tensile stress sensor 10 in series. It is connected in parallel with the resistance between the second conductive fibers 12; as a preferred embodiment, the tensile stress sensors 10 are connected in series with each other, which is beneficial to obtain a greater resistance change.

The flexible substrate 20 is insulating, and its thickness and material are determined according to actual needs. In order to facilitate the integration and miniaturization of the device, in one embodiment, the flexible substrate 20 is a flexible circuit board.

In order to achieve better encapsulation and protection effects, in one embodiment, the bending sensing device B further includes an insulating flexible protective film, and the flexible protective film covers the flexible substrate 20 and the stretchable type. On the stress sensor 10, the thickness and material of the flexible protective film are determined according to actual needs.

Specifically, two or more of the tensile stress sensors 10 may be co-located on the same surface of the flexible substrate 20 to measure the state of the flexible substrate 20 being bent toward the other surface, such as As shown in FIG. 5 ; it can also be arranged on the two surfaces of the flexible substrate 20 respectively, so as to realize the measurement of the state of the flexible substrate 20 being bent in any direction of its surface.

In the bending sensing device of the present invention, there are various ways of arranging the tensile stress sensor on the flexible substrate, and there are also various ways of connecting two or more tensile stress sensors, including the following The configuration described in the embodiment 5-9, but the bending sensor device of the present invention is not limited to the configuration of the embodiment 5-9.

Example 1: Tensile Stress Sensor

As shown in FIG. 6 , the tensile stress sensor 10a of this embodiment includes a first conductive fiber 11a and a second conductive fiber 12a, the first conductive fiber 11a is arranged straight, and its two ends are fixed respectively; the second conductive fiber 11a The conductive fiber 12a is wound on the first conductive fiber 11a and folded at both ends to form a contact portion 13 between the first conductive fiber 11a and the second conductive fiber 12a. The two ends of the second conductive fiber 12a fixed together; the first conductive fiber 11a and the second conductive fiber 12a are perpendicular to each other to form a T-shaped structure; the area of the contact portion 13 changes with the state of the second conductive fiber 12a being stretched by external force. Variety.

Example 2: Tensile stress sensor

As shown in FIG. 7 , the tensile stress sensor 10b of this embodiment includes a first conductive fiber 11b and a second conductive fiber 12b, the first conductive fiber 11b is arranged straight, and its two ends are fixed respectively; the second conductive fiber 11b The conductive fibers 12b are wound on the first conductive fibers 11b to form a contact portion 13 between the first conductive fibers 11b and the second conductive fibers 12b, and both ends of the second conductive fibers 12b are respectively fixed; The area of the contact portion 13 changes with the state of the second conductive fiber 12b being stretched by an external force.

Example 3: Tensile Stress Sensor

As shown in FIG. 8 , the tensile stress sensor 10c of this embodiment includes a first conductive fiber 11c and a second conductive fiber 12c, two ends of the first conductive fiber 11c are folded in half and fixed together; the second conductive fiber 11c The fiber 12c is wound on the first conductive fiber 11c and folded at both ends to form a contact portion 13 between the first conductive fiber 11c and the second conductive fiber 12c, and the two ends of the second conductive fiber 12c are fixed together.

The stretching direction of the first conductive fiber 11c under the external force is opposite to the stretching direction of the second conductive fiber 12c under the external force. When the first conductive fiber 11c is stretched, the second conductive fiber 12c is also stretched. When the second conductive fiber is stretched 12c, the first conductive fiber 11c is also stretched, so that the area of the contact portion 13 is pulled by an external force along with the first conductive fiber 11c and the second conductive fiber 12c changes depending on the state of extension.

Example 4: Tensile Stress Sensor

As shown in FIG. 9 , the tensile stress sensor 10d of this embodiment includes a first conductive fiber 11d and a second conductive fiber 12d, the first conductive fiber 11d is arranged straight, and its two ends are fixed respectively; the second conductive fiber 11d The conductive fibers 12d are spirally wound on the first conductive fibers 11d to form more than one contact portion 13 between the first conductive fibers 11d and the second conductive fibers 12d; The ends are respectively fixed; the total area of the contact portion 13 changes with the state of the second conductive fiber 12d being stretched by an external force.

Example 5: Bend Sensing Device

As shown in FIG. 10 , the bending sensor device B1 of this embodiment includes a tensile stress sensor 10a of Embodiment 1 and a flexible substrate 20a.

The flexible substrate 20a is a flexible circuit board, the two surfaces of which are the front and the back respectively. FIG. 10 shows the front of the flexible substrate 20a; Wires 31 and 32 are provided on the front side, and the wires 31 and 32 can be copper wires.

The tensile stress sensor 10a is disposed on the front surface of the flexible substrate 20a, wherein both ends of the first conductive fibers 11a are respectively fixed on the front surface of the flexible substrate 20a by silver glue, and the first conductive fibers 11a are respectively fixed on the front surface of the flexible substrate 20a. The ends of the two ends of the fibers 11a respectively pass through the through holes 201 and 202 to the back of the flexible substrate 20a; the two ends of the second conductive fibers 12a are fixed together on the front surface of the flexible substrate 20a by silver glue, And the ends of both ends of the second conductive fiber 12a pass through the through hole 203 to the back of the flexible substrate 20a together.

One end of the wire 31 is electrically connected to both ends of the first conductive fiber 11a, and the other end is a free end drawn out of the flexible substrate 20a; one end of the wire 32 is connected to the second conductive fiber Two ends of 12a are electrically connected, and the other end is a free end drawn out of the flexible substrate 20a. Specifically, the wires 31 can be fixedly connected to the silver glue at both ends of the first conductive fibers 11a, without being in direct contact with the first conductive fibers 11a; the wires 32 can be connected to the second conductive fibers 12a The silver glue at both ends of the two ends is fixedly connected without direct contact with the second conductive fibers 12a. The resistance between the free end of the wire 31 and the free end of the wire 32 is the resistance of the bending sensing device B1.

Through holes 201, 202 and 203 are provided on the flexible substrate 20a for the ends of the first conductive fibers 11a and the second conductive fibers 12a to pass through, so that when the tensile stress sensor 10a is installed on the front surface of the flexible substrate 20a, The back of the substrate 20a pulls the ends of the first conductive fibers 11a and the second conductive fibers 12a, so as to stretch the first conductive fibers 11a and the second conductive fibers 12a as tightly as possible.

The purpose of selecting the silver glue is that, on the one hand, the silver glue has a bonding effect, which can fix the two ends of the first conductive fiber 11a and the second conductive fiber 12a, so that the first conductive fiber 11a and the second conductive fiber 12a are kept in a taut state. , to avoid the relative displacement of the two and the disappearance of the contact part 13; on the other hand, the silver glue has a conductive function, and the wires 31 and 32 are connected with the silver glue to realize the connection between the wire 31 and the first conductive fiber 11a, the wire 32 and the The non-contact electrical connection between the second conductive fibers 12a prevents measurement errors caused by stretching the first conductive fibers 11a or the second conductive fibers 12a when the wires 31 and 32 move.

As shown in FIG. 11 , the relationship between the resistance of the bending sensing device B1 and the bending angle β of the present embodiment is measured. Specifically, the side of the flexible substrate 20a divided by the center line L1 is bent toward the back. The angle formed when the bending sensor B1 is used as the bending angle β of the bending sensing device B1, the bending angle β can be in the range of 0-180°, the center line L1 is perpendicular to the second conductive fiber 12a; the bending sensing device B1 The resistance change of is obtained by measuring the resistance value between the free end of the wire 31 and the free end of the wire 32;

The measurement results are shown in Figure 12. From this figure, it can be seen that the resistance and the bending angle β (in the range of 0-90°) are basically linear, indicating that the bending sensing device B1 has good sensing performance and can make good use of electricity. signal to represent the bending angle.

In order to verify the bending recovery performance of the bending sensor device B1, it is installed on the index finger joint of the manipulator, and the back of the flexible base 20a is in contact with the index finger joint, as shown in FIG. The bending angle β is bent several times, and after each bending for a period of time, it returns to the original straight state, and at the same time, the resistance of the bending sensing device B1 is detected in real time, so as to carry out the bending cycle experiment;

The test results are shown in Figure 13, which shows the change of the bending sensing device B1 when the bending angle β is 0°→10°→0°→15°→0°→5°→90°→45°→0° The resistance curve in the process shows that the bending sensing device B1 can still recover to the original resistance after multiple bending, which shows the feasibility of detecting the bending angle of joints in motion, and has good stability and sensitivity.

Example 6: Bend Sensing Device

As shown in FIGS. 14-16 , the bending sensing device B2 of the present embodiment includes three tensile stress sensors 10 a , 10 a ′ and 10 a ″ of the first embodiment, a flexible substrate 20 b and a flexible protective film 50 .

The flexible substrate 20b is a flexible circuit board, and its two surfaces are a front side and a back side, respectively, and FIG. 14 and FIG. 15 show the front side of the flexible substrate 20b.

The three tensile stress sensors 10a, 10a' and 10a" are all arranged on the front surface of the flexible substrate 20b. Specifically, the installation method of each tensile stress sensor on the flexible substrate 20b is the same as that in Example 5. The tension-type stress sensor 10a is installed in the same way on the flexible substrate 20a, that is, the two ends of the first conductive fiber and the second conductive fiber are fixed on the front surface of the flexible substrate 20b by silver glue, and the first conductive fiber and the ends of both ends of the second conductive fiber respectively pass through the through holes on the flexible substrate 20b to the back surface thereof.

The three tensile stress sensors 10a, 10a' and 10a" are connected in series with each other.

Specifically, as shown in FIG. 14, the three tensile stress sensors 10a, 10a' and 10a" are arranged in a row and are aligned up and down, and the three tensile stress sensors 10a, 10a' and 10a" are The direction of the formed T-shaped structure is consistent; wherein, the two ends of the second conductive fiber 12a of the tensile stress sensor 10a are connected to one end of the first conductive fiber 11a' of the tensile stress sensor 10a' through the wire 33 Electrical connection, the two ends of the second conductive fiber 12a' of the tensile stress sensor 10a' are electrically connected to one end of the first conductive fiber 11a" of the tensile stress sensor 10a" through the wire 34. Both ends of the second conductive fiber 12a" of the tensile stress sensor 10a" are connected to one end 35 of the wire, and one end of the first conductive fiber 11a of the tensile stress sensor 10a is connected to one end of the wire 36, the wire 35 The resistance between the other end of the wire 35 and the other end of the wire 36 is the resistance of the bending sensing device B2, and a resistance measuring instrument can be connected between the other end of the wire 35 and the other end of the wire 36 to measure the resistance ; The wires 33, 34, 35 and 36 are all copper wires;

Alternatively, as shown in FIG. 15, the three tensile stress sensors 10a, 10a' and 10a" are arranged in a row and aligned left and right, and the directions of the T-shaped structures formed by two adjacent tensile stress sensors are opposite; Wherein, one end of the first conductive fiber 11a of the tensile stress sensor 10a is electrically connected to one end of the first conductive fiber 11a' of the tensile stress sensor 10a' through the printed circuit 41, and the tensile stress Both ends of the second conductive fiber 12a' of the sensor 10a' are electrically connected to one end of the first conductive fiber 11a" of the tensile stress sensor 10a" through the printed circuit 42, and the first conductive fiber 11a" of the tensile stress sensor 10a" is electrically connected. Two ends of the two conductive fibers 12a" are connected to one end of the printed circuit 43, two ends of the second conductive fiber 12a of the tensile stress sensor 10a are connected to one end of the printed circuit 44, and the other end of the printed circuit 43 is connected to The resistance between the other ends of the printed circuit 44 is the resistance of the bending sensing device B2; the printed circuits 41, 42, 43 and 44 are all silver layers.

As shown in FIG. 16 , the bending sensing device B2 can be regarded as having a three-layer structure, which are the flexible protective film 50 , the sensing layer 60 and the flexible substrate 20 b in order from top to bottom; The stress sensors 10a, 10a' and 10a" can be regarded as constituting the sensing layer 60, and the flexible protective film 50 covers the front surface of the flexible substrate 20b and the sensing layer 60 to protect the packaging effect.

Example 7: Bend Sensing Device

As shown in FIG. 17 , the bending sensing device B3 of the present embodiment includes two tensile stress sensors 10e, 10f and a flexible substrate 20c.

The structure of each tensile stress sensor is basically the same as that of the tensile stress sensor 10a of Embodiment 1, except that the second conductive fibers of the two tensile stress sensors 10e and 10f share one conductive fiber. Fibers 12ef, the conductive fibers 12ef are perpendicular to the first conductive fibers 11e and 11f of the two tensile stress sensors 10e and 10f, respectively, and are connected to the first conductive fibers 11e and 11f of the two tensile stress sensors 10e and 10f, respectively The conductive fibers 11e and 11f form a T-shaped structure, and both ends of the conductive fibers 12ef are fixed, respectively.

The flexible substrate 20c is a flexible circuit board, the two surfaces of which are the front and the back respectively. Figure 17 shows the front of the flexible substrate 20c; six through holes 204, 205, 206, 207 are provided on the flexible substrate 20c , 208 and 209, and the front surfaces thereof are provided with wires 37 and 38, and the wires 37 and 38 can be copper wires.

The two tensile stress sensors 10e and 10f are both disposed on the front surface of the flexible substrate 20c, and are aligned up and down, and the direction of the T-shaped structure formed by the two tensile stress sensors 10e and 10f is on the contrary.

Specifically, the two ends of the first conductive fiber 11e of the tensile stress sensor 10e are respectively fixed on the front surface of the flexible substrate 20c by silver glue, and the ends of the two ends of the first conductive fiber 11e The through holes 204 and 205 penetrate to the back of the flexible substrate 20c; the two ends of the first conductive fiber 11f of the tensile stress sensor 10f are respectively fixed on the front of the flexible substrate 20c by silver glue, and the first conductive fiber 11f of the tensile stress sensor 10f The ends of two ends of a conductive fiber 11f respectively pass through the through holes 206, 207 to the back of the flexible substrate 20c; the ends of the two ends of the conductive fiber 12ef respectively pass through the through holes 208, 209 to the back of the flexible substrate 20c; the back of the flexible substrate 20c.

One end of the wire 37 is electrically connected to both ends of the first conductive fiber 11e of the tensile stress sensor 10e, and the other end is a free end drawn out of the flexible substrate 20c; Both ends of the first conductive fiber 11f of the tensile stress sensor 10f are electrically connected, and the other end is a free end drawn out of the flexible substrate 20c. Specifically, the wires 37 can be fixedly connected with the silver glue at both ends of the first conductive fibers 11e, without being in direct contact with the first conductive fibers 11e; the wires 38 can be connected to the first conductive fibers 11f The silver glue at the two ends of the two ends is fixedly connected without direct contact with the first conductive fibers 11f. Therefore, the two tensile stress sensors 10e and 10f are connected in series through the shared conductive fiber 12ef, and the resistance between the free end of the wire 37 and the free end of the wire 38 is the bending sensing device Resistor for B3.

In the bending sensing device B3 of this embodiment, when the side of the flexible substrate 20c divided by the center line L2 is bent toward the back, the conductive fibers 12ef are stretched, and the two The resistances of both type stress sensors 10e and 10f change to produce a response to a change in bending state, the center line L2 being perpendicular to the middle of the conductive fiber 12ef. Please refer to FIG. 18 , wherein FIGS. 18( a ), 18 ( b ) and 18 ( c ) respectively show that the bending sensing device B3 is bent at a bending angle of 0° (no bending), 60° and 90° Schematic diagram of the time.

Example 8: Bend Sensing Device

As shown in FIG. 19 , the bending sensing device B4 of the present embodiment includes two tensile stress sensors 10a, 10a' of the first embodiment and a flexible substrate 20d.

The flexible substrate 20d is a flexible circuit board, and its two surfaces are the front side and the back side, respectively. FIG. 19 shows the front side of the flexible substrate 23d.

The two tensile stress sensors 10a, 10a' are both disposed on the front surface of the flexible substrate 20d. The installation method of the tensile stress sensor 10a on the flexible substrate 20a is the same, that is, the two ends of the first conductive fiber and the second conductive fiber are fixed on the front surface of the flexible substrate 20d by silver glue, and the first conductive fiber and the second conductive fiber are fixed on the front surface of the flexible substrate 20d by silver glue. The ends of both ends of the conductive fibers are respectively protruded from the through holes on the flexible substrate 20d to the back surface thereof.

The two tensile stress sensors 10a, 10a' are connected in parallel. Specifically, the two tensile stress sensors 10a, 10a' are aligned left and right, and the directions of the T-shaped structures formed by the two tensile stress sensors 10a, 10a' are consistent; One end of the first conductive fiber 11a of the tensile stress sensor 10a and one end of the first conductive fiber 11a' of the tensile stress sensor 10a' are connected together through the printed circuit 45, and the second tensile stress sensor 10a The two ends of the conductive fiber 12a and the two ends of the second conductive fiber 12a' of the tensile stress sensor 10a' are connected together by the printed circuit 46, and the resistance between the printed circuit 45 and the printed circuit 46 is the Resistance of bend sensing device B4; the printed circuits 45 and 46 are both silver layers.

Example 9: Bend Sensing Device

As shown in FIG. 20 , the bending sensing device B5 of this embodiment includes two tensile stress sensors 10a and 10g of Embodiment 1 and a flexible substrate 20e.

The flexible substrate 20e is a flexible circuit board, and its two surfaces are the front and the back, respectively. The flexible substrate 20e is provided with six through holes 201', 202', 203', 204', 205' and 206', and the front side is provided with wires 31' and 32', and the back side is provided with wires 33' and 34' , these wires can be copper wires.

The two tensile stress sensors 10a and 10g are provided on the front and back surfaces of the flexible substrate 20e, respectively.

Specifically, as shown in FIG. 20( a ), the installation method of the tensile stress sensor 10a on the flexible substrate 20e is the same as the installation method of the tensile stress sensor 10a on the flexible substrate 20a in Embodiment 5, namely , the two ends of the first conductive fiber 11a and the second conductive fiber 12a are fixed on the front surface of the flexible substrate 20e by silver glue, and the ends of the first conductive fibers 11a are respectively connected from the through holes 201 on the flexible substrate 20e. ' and 202' go out to its back, and the ends of both ends of the second conductive fiber 12a go out to its back from the through holes 203' on the flexible substrate 20e; Both ends of the first conductive fiber 11a are electrically connected, and the other end is a free end drawn out of the flexible substrate 20e; one end of the wire 32' is electrically connected to both ends of the second conductive fiber 12a, which is The other end is the free end drawn out of the flexible substrate 20e.

Specifically, as shown in FIG. 20(b), in the tensile stress sensor 10g, both ends of the first conductive fiber 11g and the second conductive fiber 12g are fixed on the back of the flexible substrate 20e by silver glue, and all the The ends of the two ends of the first conductive fiber 11g are respectively protruded from the through holes 204' and 205' on the flexible substrate 20e to the front surface thereof, and the ends of the two ends of the second conductive fiber 12g are passed through the through holes on the flexible substrate 20e. 206' goes out to its front; at the same time, one end of the wire 33' is electrically connected to the two ends of the first conductive fiber 11g, and the other end is the free end drawn out of the flexible substrate 20e; the One end of the wire 34' is electrically connected to both ends of the second conductive fiber 12g, and the other end is a free end drawn out of the flexible substrate 20e.

The two tensile stress sensors 10a, 10g are insulated from each other, so that the two tensile stress sensors 10a, 10g measure independently, respectively, wherein the tensile stress sensor 10a measures the direction of the flexible substrate 20e toward it. The tensile stress sensor 10g measures the bending state of the flexible substrate 20e in the front direction, so the bending sensor device B5 can be used to measure the bending angle greater than 180°.

The above-mentioned embodiments only represent several embodiments of the present utility model, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the utility model patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, which all belong to the protection scope of the present invention.

Claims (10)

1. A tensile stress sensor, characterized in that it comprises a first conductive fiber and a second conductive fiber, wherein the second conductive fiber is wound on the first conductive fiber to form at least one first conductive fiber The contact part with the second conductive fiber; from the radial section of the first conductive fiber at the contact part, the second conductive fiber is located between the two central axes on both sides of the contact part respectively The angle is less than 90°; the area of the contact portion changes with the state of the second conductive fiber being stretched by an external force. 2 . The tensile stress sensor according to claim 1 , wherein when the second conductive fiber is not stretched by an external force, the area of the contact portion is the smallest. 3 . 3 . The tensile stress sensor according to claim 2 , wherein both ends of the first conductive fiber are fixed, and both ends of the second conductive fiber are fixed. 4 . 4 . The tensile stress sensor according to claim 3 , wherein the first conductive fiber is arranged straight and its two ends are fixed respectively; the second conductive fiber is wound on the first conductive fiber. 5 . And the two ends are folded in half to form a contact part between the first conductive fiber and the second conductive fiber, and the two ends of the second conductive fiber are fixed together; the first conductive fiber and the second conductive fiber They are perpendicular to each other to form a T-shaped structure. 5 . The tensile stress sensor according to claim 1 , wherein the first conductive fiber and the second conductive fiber are respectively provided with a fluffy structure at the contact portion; the fluffy structure It includes a plurality of conductive fiber filaments, and there are a plurality of gaps between the plurality of conductive fiber filaments. 6. The tensile stress sensor according to any one of claims 1-4, wherein the first conductive fiber is made of carbon, metal or conductive polymer material; the second conductive fiber is made of carbon, metal or conductive polymer materials. 7. A bending sensing device, characterized in that it comprises at least one tensile stress sensor according to any one of claims 1-6 and a flexible substrate, the tensile stress sensor being arranged on the flexible substrate , both ends of the first conductive fibers and both ends of the second conductive fibers are fixed on the flexible substrate; the second conductive fibers are stretched by the bending of the flexible substrate. 8. The bending sensing device according to claim 7, characterized in that it comprises at least two said tensile stress sensors connected in series or in parallel. 9 . The bending sensing device according to claim 8 , wherein: the tensile stress sensors are connected in series with each other; in each tensile stress sensor, the first conductive fibers are arranged straight, and the The two ends are respectively fixed; the second conductive fiber is wound on the first conductive fiber and the two ends are folded in half to form a contact part between the first conductive fiber and the second conductive fiber, the second conductive fiber The two ends are fixed together; the first conductive fiber and the second conductive fiber are perpendicular to each other to form a T-shaped structure. 10 . The bending sensing device according to claim 7 , wherein the flexible substrate is a flexible circuit board. 11 .

Images