Flexible self-energized distributed optical fiber stretching sensor

Abstract

The invention discloses a flexible self-energized distributed optical fiber tension sensor which comprises a stress luminescence mixture, a first elastomer, a second elastomer, a first silica optical fiber and a second silica optical fiber. And the stress luminescence mixture is tightly wrapped on the first elastomer. The first elastic body is used as a stretchable optical fiber wrapping layer to tightly wrap the second elastic body. And the second elastomer is made into a stretchable optical fiber core. The first silica fiber and the second silica fiber are embedded into two ends of the stretchable sensor. The stress light-emitting mixture can generate light intensity corresponding to tensile strength after being stretched, the light intensity is transmitted to two end points through the prepared stretchable optical fiber, and signals are collected by the silica optical fiber and transmitted to the distance for signal collection. Therefore, the stress position can be identified according to the light intensity proportion collected at two sides. And high-precision distributed stress identification is realized. The sensor integrates a sensing function and a transmission function, and has the characteristics of convenience in detection, simple structure, strong anti-electromagnetic interference capability and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and particularly to a structure of a flexible self-powered fiber optic tensile sensor, a preparation method thereof, and a calculation method for stress position identification. Background Art

[0002] In recent years, distributed fiber optic sensors have received extensive attention and rapid development. With the progress of fiber optic technology and the expansion of sensor application fields, they have shown great application potential in many fields such as civil engineering, environmental monitoring, oil exploration, and intelligent buildings.

[0003] Flexible and stretchable fiber optic sensors have characteristics such as softness, stretchability, and better biocompatibility. Compared with traditional distributed fiber optic sensors which have high rigidity and are difficult to stretch, they have significant advantages in human motion detection. Summary of the Invention

[0004] The main purpose of the present invention is to provide a flexible self-powered distributed fiber optic tensile sensor, which can effectively solve the problems in the background art. To achieve the above purpose, the technical solution adopted by the present invention is as follows: A flexible self-powered distributed fiber optic tensile sensor includes a stress luminescent mixture, a first elastomer, a second elastomer, a first quartz fiber, and a second quartz fiber. The stress luminescent mixture is composed of a self-luminescent material and an elastomer, and directly generates a corresponding intensity of light under the action of an external force without continuous excitation by a power source or a light source; the first elastomer is a stretchable fiber cladding made of PDMS with a main agent / curing agent ratio of 10:1; the second elastomer is a stretchable fiber core made of PDMS with a main agent / curing agent ratio of 20:1; the first quartz fiber and the second quartz fiber are multimode fibers with a transmission range from visible light to near-infrared light, and are used to transmit signals to the distal end for detection and demodulation respectively.

[0005] Preferably, the stress luminescent mixture is used to generate a light intensity signal that conforms to the tensile stimulus after receiving the tensile stimulus, and the stress luminescent mixture is tightly wrapped outside the first elastomer. The stress luminescent material in the stress luminescent mixture includes, but is not limited to, zinc sulfide.

[0006] Preferably, the first elastomer is used to prepare the cladding of the stretchable fiber, and the material is a low refractive index rubber compared to the core, including, but is not limited to, PDMS with a main agent / curing agent ratio of 10:1.

[0007] Preferably, the second elastomer is used to prepare the core of the stretchable fiber, and the material is a high refractive index rubber compared to the cladding, including, but is not limited to, PDMS with a main agent / curing agent ratio of 20:1.

[0008] Preferably, the quartz optical fiber is embedded in the second elastomer for collecting the optical signals transmitted in the second elastomer and transmitting the signals to a remote location for demodulation.

[0009] Compared with the prior art, the present invention has the following beneficial effects: 1. The tactile sensor of the present invention generates stress luminescence from a stress luminescent mixture without an external light source; 2. Compared with traditional distributed optical fibers, the sensor of the present invention has good flexibility and stretchability, and the flexible optical fiber can be used for monitoring human motion data; 3. The present invention is simple to prepare and has high precision, providing a new idea for distributed sensing. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic diagram of a flexible self-powered distributed optical fiber tensile sensor.

[0011] Figure 2 is a single-cycle stress luminescence intensity diagram of the flexible self-powered distributed optical fiber tensile sensor under different acting forces.

[0012] Figure 3 is the stability of the flexible self-powered distributed optical fiber tensile sensor under a 5 mm stretching condition.

[0013] Description of the reference numerals: 1. Stress luminescent mixture; 2. First elastomer; 3. Second elastomer; 4. First quartz optical fiber; 5. Second quartz optical fiber. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] The following specifically describes the specific embodiments of the present invention in conjunction with the drawings, but does not limit the present invention.

[0015] The flexible self-powered distributed optical fiber tensile sensor, as Figure 1 shown, includes a stress luminescent mixture 1; a first elastomer 2; a second elastomer 3; a first quartz optical fiber 4; and a second quartz optical fiber 5.

[0016] The stress luminescent mixture 1 has a cylindrical structure and tightly wraps the first elastomer 2, and the first elastomer 2 also has a cylindrical structure and tightly wraps the second elastomer 3; the second elastomer 3 has a cylindrical structure. The first quartz optical fiber 4 and the second quartz optical fiber 5 are cured in the second elastomer 3.

[0017] The stress-luminescence hybrid material 1 can directly generate stress luminescence corresponding to the force under the action of an external force, without the need for continuous power supply or light source excitation. The stress-luminescence signal can be collected through a quartz optical fiber and transmitted to a remote end for detection and demodulation. The stress-luminescence hybrid material 1 has a cylindrical structure with an inner diameter of 4 mm, an outer diameter of 5 mm, and a length of 150 mm, and is made by mixing a stress-luminescence material and an elastomer material. In this case, the elastomer material is selected as polydimethylsiloxane (PDMS), and the stress-luminescence material is selected as ZnS:Cu 2+ The reason for choosing zinc sulfide is that zinc sulfide has excellent properties such as high brightness, good self-recovery, and stability among current luminescent materials.

[0018] In this example, the first elastomer 2 selected is PDMS with a main agent / curing agent ratio of 10:1. The refractive index of the main agent / curing agent ratio of 10:1 is 1.3889, and the low-refractive-index elastic material is used to prepare the cladding of the stretchable optical fiber. The second elastomer 3 selected in this example is PDMS with a main agent / curing agent ratio of 20:1. The refractive index of the PDMS with a main agent / curing agent ratio of 20:1 is 1.4012, and the high-refractive-index elastic material is used to prepare the core of the stretchable optical fiber.

[0019] As Figure 2 shown, the light intensity generated by the flexible self-powered distributed fiber optic tensile sensor is proportional to the tensile strength received.

[0020] As Figure 3 shown, the stability of the flexible self-powered distributed fiber optic tensile sensor under the tensile condition of 5 mm for 150 times.

[0021] In summary: The present invention provides a self-powered, stretchable fiber optic strain sensor with distributed sensing capabilities. The principle is based on the fact that when the optical fiber is stimulated by tensile forces at different positions, the ratio of the different light intensities at both ends of the optical fiber can be recorded. According to the light intensity ratio, the force application position can be determined. After determining the force application position, the tensile strength can be determined according to the relationship between the tensile strength and the light intensity. In addition, multiple tensile cyclic movements in the experiment prove the excellent stability and durability of the sensor. Furthermore, the stretchable optical fiber is insensitive to signal interferences such as temperature, humidity, and bending, and can achieve accurate measurements under various conditions. Therefore, the flexible self-powered distributed fiber optic tensile sensor of the present invention shows great potential in the fields of wearable sensing, biomedical devices, health detection, etc.

[0022] The above content is a preferred embodiment of the present invention, but the embodiments of the present invention are not limited by the above content. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A self-powered optical fiber stretch sensor, characterized in that: A stress luminescent mixture (1), a first elastomer (2), a second elastomer (3), a first quartz optical fiber (4), and a second quartz optical fiber (5); The stress luminescent mixture (1) is a composite material of stress luminescent material and elastomer. After being stretched, it can generate light intensity corresponding to the stretching strength without the need for additional power supply, and is eventually transmitted to the remote end by the quartz optical fiber for recording and demodulation. The first elastomer (2) is a low-refractive-index silica gel, which serves as the cladding of the stretchable optical fiber. The second elastomer (3) is made into the stretchable optical fiber core. The first elastomer (2) tightly wraps the second elastomer (3) as the stretchable optical fiber cladding. The stress luminescent mixture is tightly wrapped outside the first elastomer (2); the quartz optical fiber (4) and the quartz optical fiber (5) are embedded at both ends of the stretchable sensor; When detecting the stretching signal, the signal intensity collected by the quartz optical fiber (4) is The signal strength collected by the quartz optical fiber (5) is The ratio of the two light intensities is Wherein: the light intensity emitted by the stress luminescent mixture (1) under stress is I0, the total length of the flexible self-powered distributed optical fiber stretch sensor is L, the distance between the light emitting position of the stress luminescent mixture (1) and the second quartz optical fiber (5) is X, and the linear attenuation coefficient of the flexible self-powered distributed optical fiber stretch sensor is .

2. A flexible self-powered optical fiber stretch sensor according to claim 1, characterized in that: The stress luminescent mixture (1), the first elastomer (2), and the second elastomer (3) are a compact structure formed by sequentially thermally curing from the outside to the inside.

3. The flexible self-powered optical fiber stretch sensor according to claim 1, characterized in that: The stress luminescent material of the stress luminescent composite (1) includes but is not limited to zinc sulfide.

4. The flexible self-powered optical fiber stretch sensor according to claim 1, characterized in that: The material of the first elastomer (2) includes but is not limited to polydimethylsiloxane (PDMS) elastomer with a ratio of main agent / curing agent = 10:

1.

5. The flexible self-powered optical fiber stretch sensor according to claim 1, characterized in that: The material of the second elastomer (3) includes but is not limited to polydimethylsiloxane (PDMS) elastomer with a ratio of main agent / curing agent = 20:

1.

6. The flexible self-powered optical fiber stretch sensor according to claim 1, characterized in that: The first quartz optical fiber (4) and the second quartz optical fiber (5) include but are not limited to visible light quartz optical fibers with a diameter of 400 um, which are used as pigtails for light collection and long-distance transmission.

7. The flexible self-powered optical fiber stretch sensor according to claim 1, characterized in that: The stress position is identified by calculating the intensity ratio at both ends using the attenuation characteristics of the optical fiber.

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