Resistance Strain Gauge, Detection Device and Environmental Stimulus Factor Level Detection Method Based on Environment-Responsive Intelligent Gel

Abstract

The present invention provides a resistance strain gauge based on an environment-responsive intelligent gel, which includes a resistive strain gauge and an intelligent gel. The intelligent gel is an integral structure, attached to the resistive strain gauge and covering both the front and back sides of the resistive strain gauge, and the intelligent gel completely covers the sensitive grid wires of the resistive strain gauge; the intelligent gel is a gel that can undergo volume shrinkage or swelling in response to external environmental stimuli, and the volume shrinkage or swelling of the intelligent gel after responding to external stimuli will cause changes in the microstrain of the resistive strain gauge. The present invention also provides a resistance strain detection device based on an environment-responsive intelligent gel, and a method for detecting the level of environmental stimulus factors based on an environment-responsive intelligent gel. The present invention can achieve highly sensitive detection of the level of environmental stimulus factors.

Description

Technical Field

[0001] The invention belongs to the field of environmental stimulus factor level detection, and relates to a resistance strain gauge based on an environment-responsive intelligent gel, a detection device and an environmental stimulus factor level detection method. Background Art

[0002] The resistance strain gauge is made based on the strain resistance effect of metal wire. The resistance strain gauge is pasted on the surface of the test piece. When the strain on the surface of the test piece changes, for example, the strain change caused by temperature, mechanical loading, internal stress, etc. will be transmitted to the sensitive grid of the strain gauge, causing the resistance of the sensitive grid to change. Environmentally responsive smart gel refers to a smart gel that shrinks or swells in volume after responding to external environment, such as temperature, humidity, pH, ion concentration, ethanol, and biomarkers. Combining smart gel with a resistance strain gauge to construct a detection sensor, the volume swelling or shrinkage of the smart gel in response to external environmental stimuli is converted and amplified into an easily detectable resistance signal, which can realize convenient, simple and rapid detection of external signals.

[0003] At present, sensors based on environment-responsive smart gels mainly include converting the volume change signal of smart gels into optical signals, electrical signals, and flow signals. Sensors based on converting volume change signals of smart gels into electrical signals mainly include piezoresistive sensors and field effect transistors. Piezoresistive sensors based on smart gels are smart gels that undergo volume changes after responding to the external environment. The resulting stress changes cause the silicon diaphragm to deform, resulting in changes in the output voltage, thereby enabling simple detection. However, the sensor only forms a responsive gel layer on the surface of the silicon diaphragm, which cannot fully reflect the volume change of the smart gel after responding to environmental stimuli, and thus has the problems of low detection sensitivity and long detection time. Field effect transistors based on smart gels are smart gels that respond to external environmental stimuli. The change in charge density inside the smart gel network causes the charge density of the gate to change, and the dielectric constant changes, thereby changing the output current of the field effect transistor. However, the mechanism of action of the field effect transistor is that the charge density on the surface of the gate changes, thereby changing the membrane potential and controlling the current between the source and the drain. This means that during the detection process, the ion concentration of the sample to be tested will also affect the charge density, so the ion concentration of the sample to be tested will interfere with the test results. Therefore, developing sensors based on environmentally responsive smart gels that are easy to prepare and detect in order to improve detection sensitivity for highly sensitive and highly selective detection remains one of the urgent issues to be solved in the field of electrical signal detection. Summary of the invention

[0004] The object of the present invention is to overcome the deficiencies of the prior art and provide a resistance strain gauge, a detection device based on an environment-responsive intelligent gel, and a method for detecting the level of environmental stimulus factors, so as to achieve highly sensitive detection of the level of environmental stimulus factors.

[0005] To achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows:

[0006] A resistance strain gauge based on an environment-responsive intelligent gel includes a resistive strain gauge and an intelligent gel. The intelligent gel is an integral structure, attached to the resistive strain gauge and covering both the front and back sides of the resistive strain gauge, and the intelligent gel completely covers the sensitive grid wires of the resistive strain gauge; the intelligent gel is a gel that can undergo volume shrinkage or swelling in response to external environmental stimuli, and the volume shrinkage or swelling of the intelligent gel in response to external stimuli will cause a change in the microstrain of the resistive strain gauge.

[0007] In the above technical solution of the resistance strain gauge based on an environment-responsive intelligent gel, the larger the size of the intelligent gel, the longer the time required for the process of volume shrinkage or swelling in response to external stimuli. For example, the longer the time required to reach volume shrinkage or swelling equilibrium in response to external stimuli. Therefore, in order to shorten the response time, the intelligent gel only needs to be able to completely cover both the front and back sides of the area where the sensitive grid wires are arranged on the resistive strain gauge and ensure that the intelligent gel is an integral structure.

[0008] Further, in the above technical solution of the resistance strain gauge based on an environment-responsive intelligent gel, the size of the intelligent gel in the longitudinal length direction of the sensitive grid wires of the resistive strain gauge does not exceed the length of the resistive strain gauge. Furthermore, the size of the intelligent gel in the direction perpendicular to the longitudinal length direction of the sensitive grid wires of the resistive strain gauge is 105% - 140% of the width of the resistive strain gauge.

[0009] In the above technical solution of the resistance strain gauge based on an environment-responsive intelligent gel, the thickness of the intelligent gel is uniform, and the thickness of the intelligent gel is at least 0.5 mm, for example, it can be 0.5 - 5 mm, preferably 0.5 - 2 mm.

[0010] In the above technical solution of the resistance strain gauge based on an environment-responsive intelligent gel, the material of the intelligent gel is a temperature-responsive intelligent gel, a humidity-responsive intelligent gel, a pH-responsive intelligent gel, or a chemical substance-responsive intelligent gel. Further, the chemical substance-responsive intelligent gel includes an ion-responsive intelligent gel and a molecular-responsive intelligent gel. These intelligent gels can be the temperature, humidity, pH, or chemical substance-responsive intelligent gels reported in the prior art. For example, common ones include:

[0011] Pb 2+Responsive intelligent gel—poly(acrylamide-co-benzo-18-crown-6 acrylamide) gel, Sr 2+ Responsive intelligent gel—poly(N-isopropylacrylamide-co-5'-O-acryloyl-2',3'-O-isopropylidene guanosine) gel, K + Responsive intelligent gel—poly(N-isopropylacrylamide-co-15-crown-5 acrylamide) gel, ethanol-responsive intelligent gel—poly(N-isopropylacrylamide-co-acrylamide) gel, bisphenol A-responsive intelligent gel—poly(N-isopropylacrylamide-co-acrylic acid) gel, human immunoglobulin-responsive intelligent gel—poly(N-isopropylacrylamide-co-goat anti-human immunoglobulin) gel, thrombin-responsive molecularly imprinted gel disclosed in CN113607693A, temperature-responsive intelligent gel—poly N-isopropylacrylamide gel, etc., but not limited to these temperature or chemical substance-responsive intelligent gels listed above.

[0012] Based on the above resistance strain gauge based on environment-responsive intelligent gel, the present invention also provides a resistance strain detection device based on environment-responsive intelligent gel. The detection device includes the above resistance strain gauge based on environment-responsive intelligent gel, and also includes a test cavity, a data acquisition system and a computer processing system; the volume of the test cavity can at least accommodate the volume swelling change of the intelligent gel of the resistance strain gauge of the environment-responsive intelligent gel after responding to external environmental stimuli;

[0013] The resistance strain gauge of the environment-responsive intelligent gel is located in the test cavity, and the wire of the resistance strain gauge of the environment-responsive intelligent gel passes through the test cavity and is connected to the data acquisition system, and the data acquisition system is connected to the computer processing system.

[0014] In the technical solution of the above resistance strain detection device based on environment-responsive intelligent gel, the test cavity is a closed cavity with a sampling tube and an outlet tube, or a closed cavity with a window that can be opened and closed.

[0015] Based on the above resistance strain detection device based on environment-responsive intelligent gel, the present invention also provides a method for detecting the level of environmental stimulation factors based on environment-responsive intelligent gel. The method uses the above resistance strain detection device based on environment-responsive intelligent gel, and includes the following steps:

[0016] ① Determine the conversion relationship between the level of environmental stimulation factors and the microstrain difference or microstrain

[0017] Method 1: Introduce a blank sample into the test cavity so that the resistance strain gauge based on the environment-responsive intelligent gel is completely in the atmosphere of the blank sample. Use the data acquisition system and the computer processing system to measure the microstrain corresponding to the blank sample. After the microstrain measured by the computer processing system reaches stability, record the microstrain corresponding to the blank sample as the initial microstrain;

[0018] Prepare a series of standard samples with different levels of environmental stimulation factors. In the order of increasing levels of environmental stimulation factors, introduce the standard samples into the test cavity so that the resistance strain gauge based on the environment-responsive intelligent gel is completely in the atmosphere of the standard samples. Use the data acquisition system and the computer processing system to measure the microstrain corresponding to each standard sample. After the microstrain measured by the computer processing system reaches stability, record the microstrain corresponding to each standard sample to obtain a series of microstrains corresponding to the standard samples;

[0019] Calculate the difference between the microstrain corresponding to each standard sample and the initial microstrain to obtain a series of microstrain differences corresponding to the standard samples. Take the microstrain differences corresponding to each standard sample as the abscissa and the levels of environmental stimulation factors assigned to each standard sample as the ordinate to plot a working curve and determine the conversion relationship between the level of environmental stimulation factors and the microstrain difference;

[0020] Or, Method 2:

[0021] Prepare a series of standard samples with different levels of environmental stimulation factors. In the order of increasing levels of environmental stimulation factors, introduce the standard samples into the test cavity so that the resistance strain gauge based on the environment-responsive intelligent gel is completely in the atmosphere of the standard samples. Use the data acquisition system and the computer processing system to measure the microstrain corresponding to each standard sample. After the microstrain measured by the computer processing system reaches stability, record the microstrain corresponding to each standard sample to obtain a series of microstrains corresponding to the standard samples;

[0022] Take the microstrain corresponding to each standard sample as the abscissa and the levels of environmental stimulation factors assigned to each standard sample as the ordinate to plot a working curve and determine the conversion relationship between the level of environmental stimulation factors and the microstrain;

[0023] ②Quantitatively measure the level of environmental stimulation factors

[0024] Replace the resistance strain gauge based on the environment-responsive intelligent gel in the detection device with the same resistance strain gauge based on the environment-responsive intelligent gel as in step ①, or restore the intelligent gel in the resistance strain gauge based on the environment-responsive intelligent gel to the state before the test in step ①;

[0025] Replace the standard specimen in step ① with the specimen to be tested, measure the microstrain corresponding to the specimen to be tested, and calculate the level of the environmental stimulus factor of the specimen to be tested according to the conversion relationship between the level of the environmental stimulus factor determined in step ① and the microstrain; or, replace the standard specimen in step ① with the specimen to be tested, measure the microstrain corresponding to the specimen to be tested and calculate the difference between the microstrain of the specimen to be tested and the initial strain, obtain the microstrain difference corresponding to the specimen to be tested, and calculate the level of the environmental stimulus factor of the specimen to be tested according to the conversion relationship between the level of the environmental stimulus factor determined in step ① and the microstrain difference.

[0026] In steps ① and ②, except for the different levels of the environmental stimulus factor, other test conditions are the same.

[0027] In the technical solution of the above method for detecting the level of the environmental stimulus factor of the environment-responsive intelligent gel, the environmental stimulus factor is related to the material of the intelligent gel of the resistance strain gauge based on the environment-responsive intelligent gel in the detection device. When the material of the intelligent gel is a temperature-responsive intelligent gel, the environmental stimulus factor is temperature; when the material of the intelligent gel is a humidity-responsive intelligent gel, the environmental stimulus factor is humidity; when the material of the intelligent gel is a pH-responsive intelligent gel, the environmental stimulus factor is pH value; when the material of the intelligent gel is a chemical substance-responsive intelligent gel, the environmental stimulus factor is the corresponding chemical substance.

[0028] When the material of the intelligent gel is a chemical substance-responsive intelligent gel and the environmental stimulus factor is the corresponding chemical substance, when detecting the level of the environmental stimulus factor (the concentration of the chemical substance that can stimulate the intelligent gel to undergo volume contraction or swelling, abbreviated as the target substance concentration), in step ①, method one is used to determine the conversion relationship between the level of the environmental stimulus factor and the microstrain difference, and in step ②, the level of the environmental stimulus factor (target substance concentration) is determined according to the conversion relationship between the level of the environmental stimulus factor and the microstrain difference.

[0029] The following gives the detection method for the level of the environmental stimulus factor (the concentration of the chemical substance that can stimulate the intelligent gel to undergo volume contraction or swelling, abbreviated as the target substance concentration) when the material of the intelligent gel is a chemical substance-responsive intelligent gel and the environmental stimulus factor is the corresponding chemical substance:

[0030] ① Determine the conversion relationship between the target substance concentration and the microstrain difference

[0031] Introduce a blank specimen into the test cavity so that the resistance strain gauge based on the environment-responsive intelligent gel is completely in the atmosphere of the blank specimen. The blank specimen does not contain the target substance. Use the data acquisition system and the computer processing system to test the microstrain corresponding to the blank specimen. After the microstrain measured by the computer processing system reaches stability, record the microstrain corresponding to the blank specimen as the initial microstrain.

[0032] Prepare a series of standard specimens with different concentrations of the target substance. In the order of increasing concentration of the target substance, introduce the standard specimens into the test cavity so that the resistive strain gauge based on the environment-responsive intelligent gel is completely in the atmosphere of the standard specimens. Use the data acquisition system and the computer processing system to measure the microstrain corresponding to each standard specimen. After the microstrain measured by the computer processing system reaches stability, record the microstrain corresponding to each standard specimen to obtain a series of microstrains corresponding to the standard specimens;

[0033] Calculate the difference between the microstrain corresponding to each standard specimen and the initial microstrain to obtain a series of microstrain differences corresponding to the standard specimens. Use the microstrain differences corresponding to each standard specimen as the abscissa and the concentration of the target substance in each standard specimen as the ordinate to plot a working curve and determine the conversion relationship between the environmental stimulus factor level and the microstrain difference;

[0034] ②Quantitatively measure the level of the environmental stimulus factor

[0035] Replace the resistive strain gauge based on the environment-responsive intelligent gel in the detection device with the resistive strain gauge based on the environment-responsive intelligent gel used in step ①, or restore the intelligent gel in the resistive strain gauge based on the environment-responsive intelligent gel to the state before the test in step ①;

[0036] Replace the standard specimen in step ① with the specimen to be tested, measure the microstrain corresponding to the specimen to be tested and calculate the difference between the microstrain of the specimen to be tested and the initial strain to obtain the microstrain difference corresponding to the specimen to be tested. Calculate the level of the environmental stimulus factor of the specimen to be tested according to the conversion relationship between the concentration of the target substance and the microstrain difference determined in step ①;

[0037] In steps ① and ②, except for the different levels of the environmental stimulus factor, other test conditions are the same.

[0038] The present invention has been experimentally verified that when the intelligent gel used is the Pb 2+ responsive intelligent gel - poly(acrylamide - co - benzo - 18 - crown - 6 acrylamide) gel, the method of the present invention can be used to detect Pb at a concentration level of 10 -8 ~10 -4 mol / L. 2+

[0039] When the material of the intelligent gel is a temperature-responsive intelligent gel and the environmental stimulus factor is temperature, when detecting the level of the environmental stimulus factor (temperature), in step ①, method two is used to determine the conversion relationship between the environmental stimulus factor level and the microstrain difference, and in step ②, the level of the environmental stimulus factor (temperature) is determined according to the conversion relationship between the environmental stimulus factor level and the microstrain difference.

[0040] ​The following gives the detection method for the level of environmental stimulus factor (temperature) when the material of the intelligent gel is a temperature-responsive intelligent gel and the environmental stimulus factor is temperature:

[0041] ① Determine the conversion relationship between temperature and microstrain

[0042] Prepare a series of standard specimens with different temperatures. In the order of increasing temperature, introduce the standard specimens into the test cavity so that the resistance strain gauge based on the environment-responsive intelligent gel is completely in the atmosphere of the standard specimens. Use the data acquisition system and the computer processing system to measure the microstrain corresponding to each standard specimen. After the microstrain measured by the computer processing system reaches stability, record the microstrain corresponding to each standard specimen to obtain a series of microstrains corresponding to the standard specimens;

[0043] Take the microstrain corresponding to each standard specimen as the abscissa and the temperature of each standard specimen as the ordinate to draw a working curve and determine the conversion relationship between temperature and microstrain;

[0044] ② Quantitatively test the level of environmental stimulus factor

[0045] Replace the resistance strain gauge based on the environment-responsive intelligent gel in the detection device with the resistance strain gauge based on the environment-responsive intelligent gel that is the same as in step ①, or let the intelligent gel in the resistance strain gauge based on the environment-responsive intelligent gel return to the state before the test in step ①;

[0046] Replace the standard specimen in step ① with the specimen to be tested, measure the microstrain corresponding to the specimen to be tested, and calculate the temperature of the specimen to be tested according to the conversion relationship between temperature and microstrain determined in step ①;

[0047] In steps ① and ②, except for the different levels of environmental stimulus factors, other test conditions are the same.

[0048] The present invention has experimentally confirmed that when the intelligent gel used is a temperature-responsive intelligent gel - poly-N-isopropylacrylamide gel, the method of the present invention can achieve the detection of the environmental temperature of 22 - 37 °C.

[0049] When the material of the intelligent gel is a pH-responsive intelligent gel and the environmental stimulus factor is pH value, the detection method for the level of environmental stimulus factor (pH value) is similar to the above temperature detection method, except that the standard specimens are a series of solutions with different pH values.

[0050] When the material of the intelligent gel is a humidity-responsive intelligent gel and the environmental stimulus factor is humidity value, the detection method for the level of environmental stimulus factor (humidity) is similar to the above temperature detection method, except that the humidity in the test cavity is adjusted to different levels, and the environments with different humidity levels are used as a series of standard samples.

[0051] The principle of the present invention for detecting the level of environmental stimulus factors based on a resistance strain gauge of an environmentally responsive intelligent gel is mainly as follows:

[0052] The present invention combines a resistive strain gauge with an environmentally responsive intelligent gel. When the intelligent gel responds to external environmental stimuli, the volume contraction or swelling that occurs will cause a change in the microstrain of the resistive strain gauge. As Figure 1 shown in Figure b of 0 , the longitudinal initial length of the sensitive grid wire of the resistance strain gauge based on the environmentally responsive intelligent gel is L 0 (as shown in Figure e of Figure 1 ). When the intelligent gel in the resistance strain gauge based on the environmentally responsive intelligent gel is stimulated by external environmental stimulus factors, volume swelling occurs. The volume swelling of the intelligent gel coated on the resistive strain gauge will cause the longitudinal length of the sensitive grid wire to increase to L 0 +ΔL (as shown in Figure c of Figure 1 ). The increase in the longitudinal length of the sensitive grid wire will cause the resistance of the resistive strain gauge to increase to R 0 +ΔR (as shown in Figure f of Figure 1 ). When the intelligent gel in the resistance strain gauge based on the environmentally responsive intelligent gel is stimulated by external environmental stimulus factors, volume contraction occurs. The volume contraction of the intelligent gel coated on the resistive strain gauge will cause the longitudinal length of the sensitive grid wire to shorten to L 0 -ΔL (as shown in Figure a of Figure 1 ). The shortening of the longitudinal length of the sensitive grid wire will cause the resistance of the resistive strain gauge to decrease to R 0 -ΔR (as shown in Figure d of Figure 1 ).

[0053] Furthermore, the present invention connects the resistance strain gauge based on the environmentally responsive intelligent gel to a data acquisition system and a computer processing system. When the intelligent gel responds to external environmental stimuli (such as temperature, humidity, pH value, chemical substances such as ions or molecules), and its volume changes, it will cause a change in the longitudinal length of the sensitive grid wire of the resistive strain gauge, and then the resistance changes. That is, the signal of the intelligent gel's response to external environmental stimuli is converted and amplified into an easily monitored resistance signal. Through the data acquisition system and the computer processing system, the microstrain change of the resistive strain gauge can be captured. Since the change in the volume of the intelligent gel is related to the change in external environmental stimuli, and the resistance signal is related to the deformation degree of the resistive strain gauge, therefore, the present invention can achieve quantitative and real-time detection of external environmental stimulus signals by measuring the microstrain or microstrain difference of the resistance strain gauge based on the environmentally responsive intelligent gel.

[0054] Compared with the prior art, the technical solution provided by the present invention has the following beneficial technical effects:

[0055] 1. The present invention provides a resistance strain gauge based on an environmentally responsive intelligent gel, and based on this strain gauge, a resistance strain detection device based on an environmentally responsive intelligent gel is provided. Since the intelligent gel is an integral structure, it adheres to the resistive strain gauge and covers both the front and back sides of the resistive strain gauge, and the intelligent gel completely covers the sensitive grid wires of the resistive strain gauge. When the intelligent gel responds to an external stimulus and undergoes volume shrinkage or swelling, the microstrain of the resistive strain gauge will change. Thus, the signal of the intelligent gel's response to the external environmental stimulus is converted and amplified into an electrical resistance signal that is easy to monitor. The microstrain change of the resistive strain gauge can be captured through a data acquisition system and a computer processing system. Since the volume change of the intelligent gel is related to the change of the external environmental stimulus, and the resistance signal is related to the deformation degree of the resistive strain gauge, therefore, by measuring the microstrain or the difference in microstrain of the resistance strain gauge based on the environmentally responsive intelligent gel, the quantitative and real-time detection of the external environmental stimulus signal can be achieved.

[0056] 2. The resistance strain gauge based on an environmentally responsive intelligent gel provided by the present invention utilizes the Wheatstone bridge amplification principle inside the resistive strain gauge to convert and amplify the volume signal generated by the intelligent gel's response to the external environmental stimulus into an electrical signal that is easy to read. Compared with an optical detection system, this resistance strain gauge based on an environmentally responsive intelligent gel is not affected by interference waves and the interference of light sources on the detection process during actual detection applications, and has the advantage of good detection accuracy.

[0057] 3. The detection device provided by the present invention can be constructed from a resistance strain gauge based on an environmentally responsive intelligent gel and conventional supporting equipment for detection based on a resistance strain gauge in the prior art, without special components, and has the characteristics of miniaturization, low price of experimental equipment, and simple operation. The environmental stimulus factor level detection method provided by the present invention is also based on this detection device. It can not only achieve highly sensitive detection of the environmental stimulus factor level, but also has simple detection operations and does not rely on professional detection personnel, and has the advantage of being easy to be widely applied. Description of the Drawings

[0058] Figure 1 is a schematic diagram of the principle for the resistance strain gauge based on an environmentally responsive intelligent gel of the present invention to achieve the detection of the environmental stimulus factor level.

[0059] Figure 2 is a schematic diagram of the structure of the resistance strain gauge based on an environmentally responsive intelligent gel, Figure 2 in which, 1 - resistive strain gauge, 2 - intelligent gel.

[0060] Figure 3Photographs of the front (Figure a) and back (Figure b) of the resistive strain gauge used in Example 1, and photographs of the front (Figure c) and back (Figure d) of the resistive strain gauge based on environmentally responsive intelligent gel.

[0061] Figure 4 Figure 4 is a schematic structural diagram of the resistive strain detection device based on environmentally responsive intelligent gel of the present invention. In the figure, 1 - resistive strain gauge, 2 - intelligent gel, 3 - test cavity, 3-1 - sampling tube, 3-2 - sample outlet tube, 4 - data acquisition system, 5 - computer processing system.

[0062] Figure 5 Figures a and b of -5 are optical photographs of the circular intelligent gel after being immersed in pure water and 10 -5 mol / L Pb 2+ solution and reaching swelling equilibrium.

[0063] Figure 6 Figure 2+ is the deformation force generated by the circular intelligent gel after being immersed in the above-mentioned Pb 2+ solution with different concentrations and reaching swelling equilibrium.

[0064] Figure 7 Figure is the relationship between the microstrain difference of the resistive strain gauge and the deformation force of the intelligent gel.

[0065] Figure 8 Figure is a working curve drawn in Example 5 with the microstrain difference corresponding to each standard specimen as the ordinate and the Pb 2+ concentration in each standard specimen as the abscissa.

[0066] Figure 9 Figure is a working curve drawn in Example 5 with the microstrain difference corresponding to each standard specimen as the abscissa and the Pb 2+ concentration in each standard specimen as the ordinate.

[0067] Figure 10 Figure is a working curve drawn in Example 8 with the microstrain corresponding to each standard specimen as the abscissa and the temperature in each standard specimen as the ordinate. Specific Embodiments

[0068] The following further illustrates the resistive strain gauge, detection device, and environmental stimulus factor level detection method based on environmentally responsive intelligent gel of the present invention through examples. It is necessary to point out that the following examples are only used to further illustrate the present invention and cannot be construed as limiting the protection scope of the present invention. Those skilled in the art make some non-essential improvements and adjustments to the present invention based on the above-mentioned invention content for specific implementation, which still fall within the protection scope of the present invention.

[0069] Example 1

[0070] In this embodiment, a resistance strain gauge based on an environmentally responsive intelligent gel and a preparation method thereof are provided.

[0071] In this embodiment, a schematic structural diagram of the resistance strain gauge based on the environmentally responsive intelligent gel is as Figure 2 shown, including a resistive strain gauge 1 and an intelligent gel 2.

[0072] The specific resistive strain gauge 1 adopted in this embodiment is composed of a substrate, a sensitive grid wire, solder joints and wires. The material of the substrate is polyimide, the material of the sensitive grid wire is constantan alloy, the sensitivity coefficient is 2, the working temperature is -70°C to +200°C, and the maximum microstrain is 50000 μm. The model of this resistive strain gauge is BA120-6AA (where 120 is the resistance value of the resistive strain gauge, and 6AA means the longitudinal length of the sensitive grid wire of the resistive strain gauge is 6 mm). It has two sides, and the sensitive grid wire is arranged on its front side (as shown in Figure 3 Figure a of Figure 3 Figure b of which is the reverse side of this resistive strain gauge.

[0073] The intelligent gel 2 is a uniform-thickness integral structure, attached to the resistive strain gauge and covering both the front and back sides of the resistive strain gauge 1, and the intelligent gel 2 completely covers the sensitive grid wire of the resistive strain gauge; the size of the intelligent gel 1 in the longitudinal length direction of the sensitive grid wire of the resistive strain gauge does not exceed the length of the resistive strain gauge, and the size of the intelligent gel 2 in the direction perpendicular to the longitudinal length direction of the sensitive grid wire of the resistive strain gauge exceeds 1 mm on each of the left and right edges of the resistive strain gauge. In this embodiment, photos of both the front and back sides of the resistance strain gauge based on the environmentally responsive intelligent gel are as shown in Figure 3 Figures c and d of

[0074] The intelligent gel 2 is a gel that can undergo volume shrinkage or swelling in response to external environmental stimuli. The volume shrinkage or swelling of the intelligent gel in response to external stimuli will cause a change in the microstrain of the resistive strain gauge 1. Specifically, this intelligent gel is a Pb 2+ -responsive intelligent gel, and the specific material is poly(acrylamide-co-benzo-18-crown-6 acrylamide) gel.

[0075] The preparation method of the above resistance strain gauge based on the environmentally responsive intelligent gel is as follows:

[0076] (1) Using acrylamide and benzo-18-crown-6 acrylamide as monomers, tetra-arm polyethylene glycol acrylamide as a crosslinking agent, ammonium persulfate as an initiator, and N,N,N’,N’-tetramethylethylenediamine as a catalyst. The monomers, crosslinking agent, initiator, and catalyst are dissolved in deionized water to form a gel prepolymer solution.

[0077] In the gel prepolymer solution, the concentration of acrylamide is 2 mol / L, the molar ratio of benzo-18-crown-6 acrylamide to acrylamide is 1:5, the mass ratio of the initiator to acrylamide is 1:10, and the molar ratio of the crosslinking agent to acrylamide is 1:50.

[0078] (2) Place a resistive strain gauge of model BA120-6AA in a mold, and make the resistive strain gauge be in the exact middle of the mold. The mold has a cuboid-shaped cavity with a length of 10 mm, a width of 4 mm, and a thickness of 1 mm. Then inject the gel prepolymer liquid into the mold to a depth of 8 mm, and place the mold under the condition of 8 °C for reaction for 7 h, and the gel prepolymer solution will turn into a gel state.

[0079] (3) Take out the resistive strain gauge with the attached gel obtained in step (2) from the mold, and soak it in deionized water for 48 h to remove the unreacted raw materials, thus obtaining a resistive strain gauge based on an environment-responsive intelligent gel.

[0080] Example 2

[0081] In this example, a resistive strain detection device based on an environment-responsive intelligent gel is provided.

[0082] The structural schematic diagram of the resistive strain detection device based on an environment-responsive intelligent gel is as Figure 4 shown, and it includes the resistive strain gauge based on an environment-responsive intelligent gel described in Example 1, a test cavity 3, a data acquisition system 4, and a computer processing system 5; the test cavity 3 is a closed cavity with a sample inlet tube 3-1 and a sample outlet tube 3-2, specifically a closed sample cell with a sample inlet tube and a sample outlet tube. The length of the closed sample cell is 2.5 cm, the width is 1 cm, and the height is 4 cm. The volume of the test cavity 3 can at least accommodate the volume swelling change of the intelligent gel of the resistive strain gauge based on an environment-responsive intelligent gel after responding to external environmental stimuli.

[0083] The resistance strain gauge of the environment-responsive intelligent gel is located in the test cavity 3. The wire of the resistance strain gauge of the environment-responsive intelligent gel passes through the test cavity 3 and is connected to the data acquisition system 4, and the data acquisition system 4 is connected to the computer processing system 5. The data acquisition system is used to collect the micro-strain signals of the resistive strain gauge, amplify the signals and transmit them to the computer processing system. The model of the data acquisition system is MX440-B. The data acquisition system has 4 interfaces and can simultaneously collect the micro-strain signals of 4 resistive strain gauges.

[0084] Example 3

[0085] In this example, the poly(acrylamide-co-benzo-18-crown-6 acrylamide) gel in Example 1 was investigated for its deformation force in response to different concentrations of Pb 2+ after that.

[0086] (1) Using acrylamide and benzo-18-crown-6 acrylamide as monomers, tetra-arm-polyethylene glycol acrylamide as a cross-linking agent, ammonium persulfate as an initiator, and N,N,N’,N’-tetramethylethylenediamine as a catalyst. The monomers, cross-linking agent, initiator, and catalyst were dissolved in deionized water to form a gel prepolymer solution.

[0087] In the gel prepolymer solution, the concentration of acrylamide was 2 mol / L, the molar ratio of benzo-18-crown-6 acrylamide to acrylamide was 1:5, the mass ratio of the initiator to acrylamide was 1:10, and the molar ratio of the cross-linking agent to acrylamide was 1:50.

[0088] (2) Inject the gel prepolymer liquid into a cylindrical mold, and then place the mold under the condition of 8 °C for reaction for 7 h. The gel prepolymer solution is transformed into a gel state, and then the obtained gel is transferred to deionized water and soaked for 48 h to remove the unreacted raw materials, thus obtaining a circular poly(acrylamide-co-benzo-18-crown-6 acrylamide) intelligent gel, simply referred to as a circular intelligent gel.

[0089] A series of identical circular gel sheets were prepared in this step.

[0090] (3) Respectively place the circular intelligent gels prepared in step (2) into Pb solutions with concentrations of 10 -8 mol / L, 10 -7 mol / L, 10 -6 mol / L, 10 -5 mol / L, 10 -4 mol / L for soaking. During the soaking process, the benzo-18-crown-6 acrylamide in the gel network can specifically recognize and capture Pb 2+ 2+ ​And form a 1:1 positively charged complex with it, resulting in an increase in the electrostatic repulsion of the gel network, manifested as the volume swelling of the circular intelligent gel.

[0091] Figure 5 Figures a and b respectively show the optical photos of the circular intelligent gel after soaking in pure water and 10 -5 mol / L Pb 2+ solution and reaching the swelling equilibrium. After soaking in pure water and reaching the swelling equilibrium, the diameter of the circular intelligent gel is 1.05 cm. After soaking in 10 -5 mol / L Pb 2+ solution and reaching the swelling equilibrium, the diameter of the circular intelligent gel is 1.25 cm.

[0092] Use a universal testing machine to test the deformation force generated by the circular intelligent gel after soaking in the above-mentioned Pb 2+ solution with different concentrations and reaching the swelling equilibrium. The results are as Figure 6 shown. As Figure 6 can be seen, due to the different degrees of volume change of the circular intelligent gel in response to different concentrations of Pb 2+ the deformation forces generated are also different.

[0093] Example 4

[0094] In this example, use the detection device described in Example 2 to test the relationship between the microstrain of the resistance strain gauge and the deformation force of the intelligent gel after the intelligent gel responds to different concentrations of Pb 2+ solution.

[0095] (1) Fill the sealed cavity of the detection device described in Example 2 with pure water, and use the data acquisition system 4 and the computer processing system 5 to test the microstrain after filling with pure water. After the microstrain measured by the computer processing system reaches stability, record the microstrain corresponding to pure water, denoted as the initial microstrain.

[0096] (2) Fill the sealed cavity of the detection device described in Example 2 with 10 -8 mol / L, 10 -7 mol / L, 10 -6 mol / L, 10 -5 mol / L, 10 -4 mol / L Pb 2+ solution respectively, and use the data acquisition system 4 and the computer processing system 5 to test the microstrain after filling with different concentrations of Pb 2+ solution. After the microstrain measured by the computer processing system reaches stability, record the microstrain corresponding to each sample. Calculate the difference between the microstrain of each sample and the initial microstrain, denoted as the microstrain difference.

[0097] (3) Combine with the deformation force generated by the circular intelligent gel after soaking in Pb solutions with different concentrations in Example 3 and reaching the swelling equilibrium, and obtain the relationship between the microstrain difference of the resistance strain gauge and the deformation force of the intelligent gel, as 2+ shown. From Figure 7 it can be seen that the microstrain difference of the resistance strain gauge increases with the increase of the deformation force of the intelligent gel, and the deformation force of the intelligent gel increases with the increase of the Pb Figure 7 concentration, that is, the microstrain difference of the resistance strain gauge also increases with the increase of the Pb 2+ concentration. 2+ The increase of the concentration.

[0098] Example 5

[0099] In this example, the detection device in Example 2 is used to determine the conversion relationship between the Pb 2+ concentration and the microstrain difference of the resistive strain gauge sensor, and the steps are as follows:

[0100] ① Use deionized water as the blank sample, introduce the blank sample into the test cavity and completely submerge the resistance strain gauge based on the environment-responsive intelligent gel, and use the data acquisition system and computer processing system to test the microstrain corresponding to the blank sample. After the microstrain measured by the computer processing system reaches stability, record the microstrain corresponding to the blank sample as the initial microstrain.

[0101] ② Prepare Pb 2+ solutions with concentrations of 10 -8 mol / L, 10 -7 mol / L, 10 -6 mol / L, 10 -5 mol / L, 10 -4 mol / L using deionized water and water-soluble lead salts as standard samples, and label them as 1# to 5# standard samples respectively. 2+ solution

[0102] Use 1# to 5# standard samples (that is, in the order of increasing Pb 2+ concentration) to replace the blank sample in step ① in turn, and measure the microstrain of each standard sample respectively to obtain a series of microstrains corresponding to the standard samples.

[0103] ③ Calculate the difference between the microstrain corresponding to the 1# to 5# standard samples and the initial microstrain to obtain a series of microstrain differences corresponding to the standard samples.

[0104] Take the microstrain difference corresponding to each standard sample as the ordinate and the Pb 2+ concentration in each standard sample as the abscissa to draw a working curve, asFigure 8 As shown, determine the conversion relationship between the microstrain difference and the Pb 2+ concentration. The result is ΔR = 102086[Pb 2+ 0.4451 , and the correlation coefficient R 2 = 0.9958. Here, ΔR is the microstrain difference with the unit of μm / m, and [Pb 2+ is the Pb 2+ concentration with the unit of mol / L.

[0105] Take the microstrain differences corresponding to each standard specimen as the abscissa and the Pb 2+ concentration in each standard specimen as the ordinate to plot the working curve. As Figure 9 shown, determine the conversion relationship between the Pb 2+ concentration and the microstrain difference. The result is [Pb 2+ = 3E-13ΔR 2.9444 , where [Pb 2+ is the lead ion concentration with the unit of mol / L, and ΔR is the microstrain difference with the unit of μm / m.

[0106] Take the Pb -8 solution with a concentration of 1×10 2+ mol / L as the test specimen. Based on the conversion relationship between the Pb 2+ concentration and the microstrain difference determined above, test the Pb 2+ concentration in the test specimen.

[0107] Replace the resistive strain gauge based on the environmentally responsive intelligent gel in the detection device with the resistive strain gauge based on the environmentally responsive intelligent gel that is the same as that in step ①, that is, replace the resistive strain gauge based on the environmentally responsive intelligent gel in the detection device used in step ① with the unused resistive strain gauge based on the environmentally responsive intelligent gel prepared in Example 1.

[0108] Replace the blank specimen in step ① with the test specimen, measure the microstrain corresponding to the test specimen and calculate the difference between the microstrain of the test specimen and the initial strain measured in step ① to obtain the microstrain difference corresponding to the test specimen. Calculate the Pb 2+ concentration in the test specimen according to the conversion relationship between the Pb 2+ concentration and the microstrain difference described above. The result is 1×10 - 8 mol / L.

[0109] Example 6

[0110] ​In this embodiment, a resistance strain gauge based on an environmentally responsive intelligent gel is provided. Its structure is basically the same as that of the resistance strain gauge based on an environmentally responsive intelligent gel in Embodiment 1, except that the material of the intelligent gel is a temperature-responsive intelligent gel, specifically poly(N-isopropylacrylamide) gel.

[0111] Embodiment 7

[0112] In this embodiment, a resistance strain detection device based on an environmentally responsive intelligent gel is provided. Its structure is basically the same as that of the resistance strain detection device based on an environmentally responsive intelligent gel in Embodiment 2, except that the resistance strain gauge based on an environmentally responsive intelligent gel in Embodiment 6 is used to replace the resistance strain gauge based on an environmentally responsive intelligent gel in Embodiment 2.

[0113] Embodiment 8

[0114] In this embodiment, the detection device in Embodiment 7 is used to determine the conversion relationship formula between the temperature and the microstrain of the resistive strain gauge sensor. The steps are as follows:

[0115] Introduce deionized water into the test cavity and completely submerge the resistance strain gauge based on the environmentally responsive intelligent gel. Place the test cavity on a temperature-controlled hot stage. Use the temperature-controlled hot stage to sequentially adjust and stabilize the temperature of the deionized water in the test cavity at 22°C, 25°C, 28°C, 31°C, 34°C, and 37°C. Take the deionized water under these temperature conditions as standard specimens, and use the data acquisition system and the computer processing system to test the microstrain corresponding to each standard specimen. After the microstrain measured by the computer processing system reaches stability, record the microstrain corresponding to each standard specimen.

[0116] Take the microstrain corresponding to each standard specimen as the abscissa and the temperature in each standard specimen as the ordinate to draw a working curve, as Figure 10 shown, and determine the conversion relationship formula between the temperature and the microstrain. The result is T = -4E-7R 3 + 0.0035R 2 - 11.554R + 12675. In the formula, T is the temperature of the environment where the resistance strain gauge based on the environmentally responsive intelligent gel is located, with the unit of °C, and R is the microstrain, with the unit of μm / m.

[0117] In practical applications, when it is necessary to detect the temperature of the specimen to be tested, first restore the temperature of the deionized water in the test cavity to 22°C so that the intelligent gel in the resistance strain gauge based on the environmentally responsive intelligent gel returns to the state before the test.

[0118] Replace the aforementioned standard specimen with the specimen to be tested. There is no need to turn on the hot stage to regulate the temperature, but heat preservation measures can be taken on the outer surface of the test cavity to prevent the temperature of the specimen to be tested from changing significantly in a short time. Use the data acquisition system and the computer processing system to test the microstrain corresponding to the specimen to be tested. After the microstrain measured by the computer processing system reaches stability, record the microstrain corresponding to the specimen to be tested.

[0119] According to the aforementioned conversion relationship between temperature and microstrain, the temperature of the specimen to be tested can be calculated from the microstrain corresponding to the specimen to be tested, that is, the temperature of the environment where the resistive strain gauge based on the environment-responsive intelligent gel is located.

[0120] Example 9

[0121] In this example, a resistive strain gauge based on an environment-responsive intelligent gel is provided. Its structure is basically the same as that of the resistive strain gauge based on the environment-responsive intelligent gel in Example 1, except that: ① the material of the intelligent gel is Sr 2+ responsive intelligent gel, specifically poly(N-isopropylacrylamide-co-5'-O-acryloyl-2',3'-O-isopropylidene guanosine) gel; ② the model of the resistive strain gauge used is BA120-3AA, the length of the intelligent gel is 5 mm, the width is 4 mm, and the thickness is 0.5 mm.

[0122] Example 10

[0123] In this example, a resistive strain detection device based on an environment-responsive intelligent gel is provided. Its structure is basically the same as that of the resistive strain detection device based on the environment-responsive intelligent gel in Example 2, except that the resistive strain gauge based on the environment-responsive intelligent gel in Example 9 is used to replace the resistive strain gauge based on the environment-responsive intelligent gel in Example 2. Using this detection device, the detection of Sr 2+ concentration can be realized according to the method of Example 5.

[0124] Example 11

[0125] In this example, a resistive strain gauge based on an environment-responsive intelligent gel is provided. Its structure is basically the same as that of the resistive strain gauge based on the environment-responsive intelligent gel in Example 1, except that: ① the material of the intelligent gel is K + responsive intelligent gel, specifically poly(N-isopropylacrylamide-co-15-crown-5 acrylamide) gel; ② the model of the resistive strain gauge used is BA120-10AA, the length of the intelligent gel is 12 mm, the width is 4 mm, and the thickness is 1.5 mm.

[0126] Example 12

[0127] In this embodiment, a resistance strain detection device based on an environment-responsive intelligent gel is provided. Its structure is basically the same as that of the resistance strain detection device based on an environment-responsive intelligent gel in Embodiment 2, except that the resistance strain gauge based on an environment-responsive intelligent gel in Embodiment 11 is used to replace the resistance strain gauge based on an environment-responsive intelligent gel in Embodiment 2. Using this detection device, K can be realized according to the method in Embodiment 5 + concentration detection, for example, the detection of K in blood can be realized + concentration detection.

[0128] Embodiment 13

[0129] In this embodiment, a resistance strain gauge based on an environment-responsive intelligent gel is provided. Its structure is basically the same as that of the resistance strain gauge based on an environment-responsive intelligent gel in Embodiment 1, except that: ① the material of the intelligent gel is an ethanol-responsive intelligent gel, specifically poly(N-isopropylacrylamide-co-acrylamide) gel; ② the model of the resistive strain gauge used is BA120-6AA, the length of the intelligent gel is 8 mm, the width is 4 mm, and the thickness is 2 mm.

[0130] Embodiment 14

[0131] In this embodiment, a resistance strain detection device based on an environment-responsive intelligent gel is provided. Its structure is basically the same as that of the resistance strain detection device based on an environment-responsive intelligent gel in Embodiment 2, except that the resistance strain gauge based on an environment-responsive intelligent gel in Embodiment 13 is used to replace the resistance strain gauge based on an environment-responsive intelligent gel in Embodiment 2. Using this detection device, the detection of ethanol concentration can be realized according to the method in Embodiment 5.

[0132] Embodiment 15

[0133] In this embodiment, a resistance strain gauge based on an environment-responsive intelligent gel is provided. Its structure is basically the same as that of the resistance strain gauge based on an environment-responsive intelligent gel in Embodiment 1, except that the material of the intelligent gel is a bisphenol A-responsive intelligent gel, specifically poly(N-isopropylacrylamide-co-acrylic acid) gel.

[0134] Embodiment 16

[0135] In this embodiment, a resistance strain detection device based on an environmentally responsive intelligent gel is provided. Its structure is basically the same as that of the resistance strain detection device based on an environmentally responsive intelligent gel in Embodiment 2, except that the resistance strain gauge based on an environmentally responsive intelligent gel in Embodiment 15 is used to replace the resistance strain gauge based on an environmentally responsive intelligent gel in Embodiment 2. Using this detection device, the detection of bisphenol A concentration can be achieved with reference to the method in Embodiment 5.

[0136] Embodiment 17

[0137] In this embodiment, a resistance strain gauge based on an environmentally responsive intelligent gel is provided. Its structure is basically the same as that of the resistance strain gauge based on an environmentally responsive intelligent gel in Embodiment 1, except that the intelligent gel is made of a human immunoglobulin-responsive intelligent gel, specifically poly(N-isopropylacrylamide-co-goat anti-human immunoglobulin) gel.

[0138] Embodiment 18

[0139] In this embodiment, a resistance strain detection device based on an environmentally responsive intelligent gel is provided. Its structure is basically the same as that of the resistance strain detection device based on an environmentally responsive intelligent gel in Embodiment 2, except that the resistance strain gauge based on an environmentally responsive intelligent gel in Embodiment 17 is used to replace the resistance strain gauge based on an environmentally responsive intelligent gel in Embodiment 2. Using this detection device, the detection of human immunoglobulin concentration can be achieved with reference to the method in Embodiment 5.

Claims

1. A resistance strain gauge based on an environmentally responsive intelligent gel, characterized in that, it includes a resistive strain gauge (1) and an intelligent gel (2). The intelligent gel (2) is an integral structure, attached to the resistive strain gauge and covering both the front and back sides of the resistive strain gauge (1), and the intelligent gel (2) completely covers the sensitive grid wires of the resistive strain gauge; the intelligent gel (2) is a gel that can undergo volume shrinkage or swelling in response to external environmental stimuli, and the volume shrinkage or swelling of the intelligent gel in response to external stimuli will cause a change in the microstrain of the resistive strain gauge (1); the size of the intelligent gel (2) in the longitudinal length direction of the sensitive grid wires of the resistive strain gauge does not exceed the length of the resistive strain gauge; the size of the intelligent gel (2) in the direction perpendicular to the longitudinal length direction of the sensitive grid wires of the resistive strain gauge is 105% - 140% of the width of the resistive strain gauge (1); the thickness of the intelligent gel (2) is uniform, and the thickness of the intelligent gel (2) is 0.5 - 2 mm; the intelligent gel (2) is a poly(acrylamide - co - benzo - 18 - crown - 6 acrylamide) gel.

2. A resistance strain detection device based on an environmentally responsive intelligent gel, characterized in that, it includes the resistance strain gauge based on an environmentally responsive intelligent gel described in claim 1, and also includes a test cavity (3), a data acquisition system (4) and a computer processing system (5); the volume of the test cavity (3) can at least accommodate the volume swelling change of the intelligent gel (2) of the resistance strain gauge based on an environmentally responsive intelligent gel in response to external environmental stimuli; the resistance strain gauge based on an environmentally responsive intelligent gel is located in the test cavity (3), the wire of the resistance strain gauge based on an environmentally responsive intelligent gel passes through the test cavity (3) and is connected to the data acquisition system (4), and the data acquisition system (4) is connected to the computer processing system (5).

3. The resistance strain detection device based on an environmentally responsive intelligent gel according to claim 2, characterized in that, the test cavity (3) is a closed cavity with a sampling tube (3 - 1) and an outlet tube (3 - 2), or a closed cavity with a window that can be opened and closed.

4. A method for detecting the level of environmental stimulus factors based on an environmentally responsive intelligent gel, characterized in that, this method uses the detection device described in claim 2 or 3, and includes the following steps: ① Determine the conversion relationship between the level of environmental stimulus factors and the difference in microstrain Introduce a blank sample into the test cavity so that the resistance strain gauge based on an environmentally responsive intelligent gel is completely in the atmosphere of the blank sample, use the data acquisition system and the computer processing system to test the microstrain corresponding to the blank sample, and after the microstrain measured by the computer processing system reaches stability, record the microstrain corresponding to the blank sample as the initial microstrain; Prepare a series of standard specimens with different levels of environmental stimulus factors. In the order of increasing environmental stimulus factor levels, introduce the standard specimens into the test cavity so that the resistance strain gauge based on the environment-responsive intelligent gel is completely in the atmosphere of the standard specimens. Use the data acquisition system and the computer processing system to measure the microstrain corresponding to each standard specimen. After the microstrain measured by the computer processing system reaches stability, record the microstrain corresponding to each standard specimen to obtain a series of microstrains corresponding to the standard specimens; Calculate the difference between the microstrain corresponding to each standard specimen and the initial microstrain to obtain a series of microstrain differences corresponding to the standard specimens. Take the microstrain differences corresponding to each standard specimen as the abscissa and the environmental stimulus factor levels assigned to each standard specimen as the ordinate to plot a working curve and determine the conversion relationship between the environmental stimulus factor level and the microstrain difference; ②Quantitatively measure the level of environmental stimulus factors Replace the resistance strain gauge based on the environment-responsive intelligent gel in the detection device with the resistance strain gauge based on the environment-responsive intelligent gel used in step ①, or restore the intelligent gel in the resistance strain gauge based on the environment-responsive intelligent gel to the state before the test in step ①; Replace the standard specimen in step ① with the specimen to be tested, measure the microstrain corresponding to the specimen to be tested and calculate the difference between the microstrain of the specimen to be tested and the initial strain to obtain the microstrain difference corresponding to the specimen to be tested. Calculate the level of the environmental stimulus factor of the specimen to be tested according to the conversion relationship between the environmental stimulus factor level and the microstrain difference determined in step ①; In steps ① and ②, except for the different levels of environmental stimulus factors, other test conditions are the same; the level of the environmental stimulus factor refers to the Pb 2+ concentration.

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