Method for detecting humidity by using araneus ventricosus dragline silk combined with micro-bottle resonant cavity

Abstract

The application discloses a method for detecting humidity by using Nephila clavipes traction silk combined with a micro-bottle resonant cavity, and comprises the following steps: 1, manufacturing the Nephila clavipes traction silk combined micro-bottle resonant cavity structure: (1) manufacturing a micro-bottle resonant cavity; (2) manufacturing a contraction rope woven by Nephila clavipes traction silk; (3) combining the Nephila clavipes traction silk with the micro-bottle resonant cavity; 2, based on the Nephila clavipes traction silk contraction rope combined micro-bottle resonant cavity structure manufactured in step 1, the environmental humidity is measured. The application combines the Nephila clavipes traction silk with the whispering gallery mode micro-bottle resonant cavity, uses the natural biological material Nephila clavipes traction silk to replace various hydrophilic materials coated on the surface of the micro-bottle resonant cavity, avoids complicated coating or deposition processes, simplifies the manufacturing process of the optical fiber humidity sensor, and greatly improves the stability and reliability of the structure in practical application due to the high strength, high flexibility and the superiority of the Nephila clavipes traction silk in sensing the humidity in the air.

Description

Technical Field

[0001] This invention relates to the field of fiber optic sensor technology, and in particular to a method for detecting humidity using a microbottle resonator (MBR) with a large-diameter circular traction wire. Background Technology

[0002] The traction silk of the orb-weaver spider possesses high strength and flexibility, which is beneficial for the miniaturization of humidity sensors at the microscale. The molecules in the traction silk are arranged in a tightly ordered, crystalline manner, similar to the crystalline structure of metal. Some cross-sections exhibit molecular arrangements resembling the molecular structure of rubber. These alternating cross-sections are the fundamental reason for the high strength and flexibility of the traction silk. Furthermore, because the protein components that make up the orb-weaver spider's traction silk have good moisture sensitivity, the traction silk undergoes super-shrinkage upon absorbing water, further improving the measurement accuracy of the humidity sensor.

[0003] Whispering-gallery mode microcavities have extremely small mode volumes, confining light energy within a micrometer-sized cavity. Even a single photon can generate a very strong electric field within the cavity, enabling strong interactions with other substances and exhibiting extremely high sensitivity. In humidity sensing, hydrophilic materials are typically coated onto the surface of the microcavity, and humidity sensing is achieved through the sensitivity of the hydrophilic material to water molecules. The geometric dimensions of microcavities are generally on the micrometer scale. Whether coating the surface of a microcavity with hydrophilic materials or using hydrophilic materials to fabricate the microcavity, the fabrication process and technology are extremely complex, requiring a high-precision platform. Unlike hydrophilic materials such as agarose, graphene oxide films, and zinc oxide, which require coating the surface of the microcavity, or using hydrophilic materials like glycerol directly to fabricate whispering-gallery mode microcavities, the traction silk of the giant spider, with its unique water absorption and ultra-high strength, avoids the need for precise coating operations at the micrometer scale, thus requiring less precision in the fabrication process.

[0004] In summary, current applications of fiber optic sensors for humidity sensing primarily involve coating the surface of whispering-gallery mode microcavities with various hydrophilic materials. However, most of these coating methods have stringent preconditions or complex operations, hindering fabrication and severely impacting the stability and strength of the whispering-gallery mode microcavities, thus impeding practical applications. The method of using a spider silk traction thread combined with a micro-bottle resonator to detect air humidity eliminates the need for material coating on the micro-bottle resonator surface. Instead, a contractile rope made from spider silk traction thread suspends one end of the micro-resonator. Humidity sensing is achieved by leveraging the super-contraction property of the spider silk after absorbing water, thereby altering the coupling state between the micro-bottle resonator and the tapered optical fiber.

[0005] Therefore, this invention develops a method for detecting humidity by combining the traction silk of a large-bellied spider with a micro-bottle resonant cavity, which effectively reduces the complexity of the manufacturing process and has a stable and highly repeatable structure. Summary of the Invention

[0006] In view of the above-mentioned deficiencies of the prior art, the purpose of this invention is to provide a method for detecting humidity by combining the traction silk of the giant spider with a micro-bottle resonant cavity, wherein the main component protein of the giant spider traction silk has a very strong affinity for water molecules, so the sensor is very sensitive to air humidity.

[0007] To achieve the above objectives, the present invention provides a method for detecting humidity using a micro-bottle resonant cavity combined with the traction silk of a large-bellied spider, comprising the following steps:

[0008] Step 1: Fabrication of the spider silk combined with the micro-bottle resonant cavity structure, consisting of the following three parts:

[0009] (1) Fabrication of a micro-bottle resonant cavity

[0010] The coating layer of a single-mode optical fiber is removed, and its end face is cut using a fiber cleaver. The cut single-mode optical fiber is placed in a fiber fusion splicer, and one end of the single-mode optical fiber is melted by electrode arc discharge, forming a sphere under the action of surface tension, thus obtaining a single-mode optical fiber with a microsphere at one end. Another single-mode optical fiber with its end face cut is placed in the fiber fusion splicer and aligned with the single-mode optical fiber with a microsphere at one end before being fused together, finally forming a micro-bottle resonant cavity.

[0011] (2) Making a shrink rope woven from the spider's trailing silk.

[0012] One end of the traction silk is drawn from the tail of a live giant spider and attached to the outer wall of a cylindrical test tube. The cylindrical test tube is rotated at a constant speed, and the traction silk will be evenly wrapped around the outer wall of the test tube. After removing the traction silk, the silk is wrapped in two strands, and then the two strands are wrapped together again, making a total of four strands of spider silk to form a shrink rope.

[0013] (3) Combining the traction filaments of the giant spider with the micro-bottle resonant cavity

[0014] One end of the micro-bottle resonant cavity is fixed to the fixture, while the other end is suspended. One end of the contraction rope woven from the traction silk of the giant spider is fixed above the suspended end of the micro-bottle resonant cavity. The movable end of the contraction rope is fixed to the suspended end of the micro-bottle resonant cavity using UV glue. The structure of the giant spider traction silk combined with the micro-bottle resonant cavity is thus completed.

[0015] Furthermore, in step 1, the cladding diameter of the single-mode fiber is 125 μm, the core diameter is 10 μm, the fiber fusion splicer is a Fujikura (100P+) and the fiber cleaver is a Sumitomo (FC-6S).

[0016] Furthermore, the specific parameters for melting the single-mode optical fiber by electrode arc discharge in step 1 are a discharge intensity of 10 mA and a discharge time of 800 ms.

[0017] Furthermore, in step 1, the microsphere of the single-mode optical fiber, which is a microsphere at one end, has a diameter of 170 μm.

[0018] Furthermore, the specific parameters for splicing the single-mode fiber with the cut end face in step 1 to the single-mode fiber with a microsphere at one end are: discharge intensity 10mA and discharge time 500ms.

[0019] Furthermore, the diameter of the micro-bottle resonant cavity in step 1 is 150 μm, and the length of the micro-bottle region is 200 μm.

[0020] Furthermore, in step 1, the diameter of the traction silk of the giant spider is 4 to 8 μm, and the length of the prepared shrink rope is 1 cm.

[0021] Furthermore, the UV adhesive curing time in step 1 is 10 seconds.

[0022] Step 2: Based on the large-bellied spider traction silk combined with the micro-bottle resonant cavity sample prepared in Step 1, the ambient humidity is measured:

[0023] The *Archaeopteryx* traction silk combined with the micro-bottle resonator sample and the tapered optical fiber described in step 1 are placed in a sealed box. The top of the sealed box is cut open to place a microscope, and the side is cut open to insert a humidifier pipe. A digital signal generator is connected to oscilloscope input port a and a tunable laser, respectively. One end of the tapered optical fiber is connected to the tunable laser, and the other end is incident on a photodetector. The photodetector is connected to oscilloscope input port b. The microscope is used to observe and, in conjunction with a 3D platform, adjust the coupling state between the *Archaeopteryx* traction silk combined with the micro-bottle resonator sample and the tapered optical fiber. After adjusting to a stable coupling state, the top cover of the sealed box is closed, and the humidity inside the sealed box is changed by the humidifier. After the humidity increases, the contraction rope woven by the *Archaeopteryx* traction silk will absorb moisture from the air and produce a super-contraction phenomenon. Based on this, the suspended end of the micro-bottle resonator is subjected to an upward force, which changes the distance between the micro-bottle resonator and the tapered optical fiber, and the coupling state between the two changes. At the same time, the oscilloscope displays the waveform movement change, realizing the measurement of ambient humidity.

[0024] Furthermore, the dimensions of the sealed box in step 2 are 40*50*50cm.

[0025] Furthermore, the parameters of the triangular wave signal generated by the digital signal generator in step 2 are 10Hz and 1Vpp; the tunable laser is a SANTEC TSL-710; and the photodetector range is 1400-1700nm.

[0026] Furthermore, the oscilloscope used in step 2 is a Tektronix MDO4034C.

[0027] Furthermore, in step 2, the microscope eyepiece magnification is 2 and the objective lens magnification is 7.5.

[0028] Furthermore, the diameter of the uniform tapered waist region of the tapered optical fiber in step 2 is 2 μm.

[0029] Furthermore, the increase in humidity in step 2 is achieved by keeping the room temperature constant at 24.5°C and gradually increasing the indoor humidity from 31.5%RH to 81.5%RH.

[0030] The beneficial effects of this invention are as follows:

[0031] (1) The basic structure of this invention is simple, requiring only single-mode optical fiber and traction silk from the giant spider.

[0032] (2) The spider silk used in this invention has high strength and is quite sensitive to moisture in the air. It is a natural biological humidity sensor with a small structure and simple manufacturing process.

[0033] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the fabrication process of a micro-bottle resonant cavity according to a preferred embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the spider silk weaving process according to a preferred embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of a humidity measuring device according to a preferred embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of the equatorial cross-section of a micro-bottle resonator coupled to a tapered fiber waveguide according to a preferred embodiment of the present invention;

[0038] Figure 5 This is a humidity sensitivity spectrum of a preferred embodiment of the present invention;

[0039] Among them, 1-single-mode optical fiber, 2-electrode inside the optical fiber fusion splicer, 3-spherical shape of the fused tip of the single-mode optical fiber, 4-micro-bottle resonant cavity, 5-large-bellied spider traction wire, 6-contraction rope woven from the large-bellied spider traction wire, 7-tapered optical fiber, 8-fixed end. Detailed Implementation

[0040] The preferred embodiments of the present invention are described below with reference to the accompanying drawings to make the technical content clearer and easier to understand. The present invention can be embodied in many different forms, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0041] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of some components has been appropriately exaggerated in the drawings.

[0042] Example

[0043] This embodiment provides a method for detecting humidity using a combination of a large-bellied spider's traction silk and a micro-bottle resonant cavity, including the following steps:

[0044] Step 1: Fabrication of a micro-bottle resonant cavity structure using the traction silk of the giant spider.

[0045] (1) Fabrication of a micro-bottle resonant cavity

[0046] The coating layer of a single-mode optical fiber is removed, and the end face is cut using a fiber cleaver. The cut single-mode optical fiber is placed in a fiber fusion splicer, and one end of the single-mode optical fiber is melted by electrode arc discharge, forming a sphere under the action of surface tension, resulting in a single-mode optical fiber with a microsphere at one end and a diameter of 170 μm. Another single-mode optical fiber with a cut end face is placed in the fiber fusion splicer and aligned with the first optical fiber before being fused together, finally forming a micro-bottle resonant cavity with a diameter of 150 μm and a length of 200 μm for the micro-bottle region.

[0047] The single-mode fiber has a cladding diameter of 125 μm and a core diameter of 10 μm.

[0048] (2) Making a shrink rope woven from the spider's trailing silk.

[0049] One end of the traction silk is drawn from the tail of a live giant orb-weaver spider and attached to the outer wall of a cylindrical test tube. The cylindrical test tube is rotated at a constant speed, and the traction silk will be evenly wrapped around the outer wall of the test tube. After removing the traction silk, the silk is wrapped in two strands, and then the braided silk is used as one strand, and then wrapped in two strands in two. A total of four strands of traction silk are wrapped together to make a shrink rope with a length of 1cm.

[0050] The diameter of the traction silk of the giant orb-weaver spider is 4 to 8 μm.

[0051] (3) Combining the traction filaments of the giant spider with the micro-bottle resonant cavity

[0052] One end of the micro-bottle resonator is fixed to the fixture, while the other end is suspended. One end of the contraction rope woven from the traction silk of the giant spider is fixed above the suspended end of the micro-bottle resonator. The movable end of the contraction rope is fixed to the suspended end of the micro-bottle resonator using UV glue. The micro-bottle resonator is then constructed by combining the giant spider traction silk with the micro-bottle resonator.

[0053] Step 2: Detect ambient humidity based on the structure prepared in Step 1.

[0054] The large-bellied spider traction silk combined with the micro-bottle resonant cavity sample described in step one, along with a tapered optical fiber with a uniform conical waist diameter of 2 μm, was placed in a sealed box measuring 40*50*50 cm. A microscope with an eyepiece magnification of 2x and an objective lens magnification of 7.5x was placed in the top of the sealed box, and a humidifier pipe was inserted through a side cut. A digital signal generator was connected to oscilloscope input port a and a tunable laser, generating a triangular wave signal with parameters of 10 Hz and 1 Vpp. One end of the tapered optical fiber was connected to the tunable laser, and the other end was incident on a photodetector with a range of 1400-1700 nm. The photodetector was connected to oscilloscope input port b. Microscopic observation and coordination were performed. The coupling state between the spider silk traction wire and the micro-bottle resonator sample and the tapered optical fiber was adjusted using a 3D platform. After achieving a stable coupling state, the top cover of the sealed box was closed, and the humidifier was turned on to change the humidity inside the sealed box. The room temperature was kept constant at 24.5℃, and the indoor humidity was gradually increased from 31.5%RH to 81.5%RH. The shrinkage rope woven by the spider silk absorbed moisture from the air and underwent super-shrinkage, resulting in an upward force acting on the suspended end of the micro-bottle resonator. This changed the distance between the micro-bottle resonator and the tapered optical fiber, altering their coupling state. Simultaneously, the oscilloscope displayed the waveform shift, thus enabling the measurement of the ambient humidity.

[0055] This embodiment uses a spider's traction wire combined with a micro-bottle resonator and a tapered optical fiber to measure air humidity. The embodiment uses a shrinkable rope made of spider traction wire as the humidity-sensitive material. This structure has a simpler manufacturing process compared to humidity sensing structures that coat the surface of a whispering-gallery mode micro-resonator with a hydrophilic material. Spider traction wire has high strength and is also a natural humidity sensor found in nature. The spider traction wire is coupled to the micro-bottle resonator via a waveguide in the tapered optical fiber. Light propagates in the uniform conical waist region of the tapered optical fiber in the form of an evanescent field. When the distance between the uniform conical waist region of the tapered optical fiber and the micro-bottle resonator is sufficiently close, the light is coupled into the micro-bottle resonator through the evanescent field, exciting the whispering-gallery mode.

[0056] Orb-weaver spider traction silk is a natural biomaterial with high strength and high flexibility. The protein components that make up the orb-weaver spider traction silk have good moisture sensitivity and hygroscopicity, which can further improve the measurement accuracy of humidity sensors.

[0057] This invention features a compact and highly repeatable structure with a simple basic structure, requiring only single-mode optical fiber and large-bellied spider traction wire. Through simple structural combination, it successfully reduces the process complexity of fabricating sensor structures in the field of humidity sensing. It has important application value in fields such as construction engineering, chemical industry, and aerospace, and provides new ideas for improving sensor humidity detection methods and other related fields.

[0058] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for detecting humidity using a micro-bottle resonant cavity combined with the traction silk of a large-bellied spider, characterized in that, Includes the following steps: Step 1: Fabrication of the spider silk combined with the micro-bottle resonant cavity structure (1) Fabrication of a micro-bottle resonant cavity Remove the coating from a single-mode optical fiber and cut the end face using a fiber cleaver. The cut single-mode fiber is placed in a fiber fusion splicer, and the end face of the single-mode fiber is melted by electrode arc discharge. Under the action of surface tension, it forms a sphere, resulting in a single-mode fiber with a microsphere at one end. Another single-mode fiber with a cut end face is placed in the fiber fusion splicer and aligned with the single-mode fiber with a microsphere at one end before being fused together to finally form a micro-bottle resonant cavity. (2) Making a shrink rope woven from the spider's trailing silk. One end of the traction silk is drawn from the tail of a live giant spider and attached to the outer wall of a cylindrical test tube. The cylindrical test tube is rotated at a constant speed, and the traction silk will be evenly wrapped around the outer wall of the test tube. After taking out the traction silk, it is wrapped in two strands, and then the braided strands are used as one strand, and then wrapped in two strands in two, for a total of four strands of spider silk are wrapped together to make a shrink rope. (3) Combining the traction filaments of the giant spider with the micro-bottle resonant cavity One end of the micro-bottle resonant cavity is fixed to the clamp, and the other end is suspended. One end of the contraction rope woven from the traction silk of the giant spider is fixed above the suspended end of the micro-bottle resonant cavity. The movable end of the contraction rope is fixed to the suspended end of the micro-bottle resonant cavity using ultraviolet glue. The structure of the giant spider traction silk combined with the micro-bottle resonant cavity is completed. Step 2: Based on the large-bellied spider traction silk combined with the micro-bottle resonant cavity structure fabricated in Step 1, the ambient humidity is measured. The large-bellied spider traction silk combined with the micro-bottle resonant cavity sample and the tapered optical fiber described in step 1 are placed in a sealed box. The top of the sealed box is cut open to place a microscope, and a small hole is cut open on the side to insert a humidifier pipe. The digital signal generator is connected to the oscilloscope input port a and the tunable laser respectively. One end of the tapered optical fiber is connected to a tunable laser, and the other end is incident on a photodetector. The photodetector is connected to the oscilloscope input port b; the coupling state between the spider silk traction wire, the micro-bottle resonator sample, and the tapered optical fiber is adjusted using a microscope and a 3D platform; after adjusting to a stable coupling state, the top cover of the sealed box is closed, and the humidity inside the sealed box is changed by a humidifier; as the humidity increases, the shrinking rope woven by the spider silk absorbs moisture from the air and shortens in length. Based on this, the suspended end of the micro-bottle resonator is subjected to an upward force, which changes the distance between the micro-bottle resonator and the tapered optical fiber, thus changing the coupling state between them. At the same time, the oscilloscope displays the waveform movement change, realizing the measurement of humidity in the air.

2. The method for detecting humidity using a combination of a large-bellied spider's traction silk and a micro-bottle resonant cavity as described in claim 1, characterized in that... In step 1, the single-mode fiber cladding diameter is 125 μm, the fiber core diameter is 10 μm, the micro-bottle resonator diameter is 150 μm, and the length of the micro-bottle region is 200 μm.

3. The method for detecting humidity using a micro-bottle resonant cavity combined with the traction silk of a giant spider as described in claim 1, characterized in that... The specific parameters for melting the single-mode optical fiber by electrode arc discharge in step 1 are: discharge intensity of 10mA and discharge time of 800ms.

4. The method for detecting humidity using a micro-bottle resonant cavity combined with the traction silk of a large-bellied spider as described in claim 1, characterized in that... The specific parameters for splicing the single-mode fiber with the cut end face in step 1 to the single-mode fiber with a microsphere at one end are: discharge intensity 10mA and discharge time 500ms.

5. The method for detecting humidity using a combination of a large-bellied spider's traction silk and a micro-bottle resonant cavity as described in claim 1, characterized in that... The traction silk of the giant spider in step 1 has a diameter of 4 to 8 μm, and the prepared shrink rope has a length of 1 cm.

6. The method for detecting humidity using a combination of a large-bellied spider's traction silk and a micro-bottle resonant cavity as described in claim 1, characterized in that... The parameters of the triangular wave signal generated by the digital signal generator in step 2 are 10Hz and 1Vpp; the tunable laser is a SANTEC TSL-710; and the photodetector range is 1400-1700nm.

7. The method for detecting humidity using a micro-bottle resonant cavity combined with the traction silk of a large-bellied spider as described in claim 1, characterized in that, The uniform tapered waist region diameter of the tapered optical fiber in step 2 is 2 μm.

8. The method for detecting humidity using a combination of a large-bellied spider's traction silk and a micro-bottle resonant cavity as described in claim 1, characterized in that... The increase in humidity in step 2 is achieved by keeping the room temperature constant at 24.5°C and gradually increasing the indoor humidity from 31.5%RH to 81.5%RH.

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