A current-modulated multi-current structure gas sensor

Abstract

The present invention discloses a current-modulated multi-current collecting structure gas sensor. The multi-current collecting structure gas sensor includes a solid electrolyte and a unit electrode group; the unit electrode group is set as one or more; each unit electrode group includes a sensitive electrode, a counter electrode and a current collecting group, the sensitive electrode is set as at least one, and the counter electrode is set as at least one; or each unit electrode group includes a sensitive electrode and a current collecting group, the sensitive electrode is set as at least two; the current collecting group is composed of a plurality of current collectors, the current collecting group is in contact with the sensitive electrode and the two adjacent current collectors are not in contact with each other. The present invention improves the structure of the gas sensor. By introducing a multi-current collecting structure, under the polarization effect of the bias current, the dimension of the gas-sensitive signal is expanded in a simple way with low cost and low power consumption, providing a new solution for improving the detection accuracy of the gas sensor.

Description

Technical Field

[0001] The invention belongs to the field of gas sensor detection, and in particular relates to a current-modulated multi-current collecting structure gas sensor. Background Art

[0002] Gas sensors, as essential tools for monitoring the composition and concentration of various gases in the environment, are widely used in fields such as air quality monitoring, industrial process control, safety warnings, and healthcare. However, in the complex environments of real-world applications, the cross-sensitivity of single-signal sensors to different gases is particularly prominent, which can easily lead to risks such as false alarms and missed alarms, posing severe challenges to their reliability and accuracy.

[0003] In order to further improve the sensor's ability to identify different gases, increasing the signal dimension of the gas-sensitive response has become a key technical strategy. Recently, researchers have proposed a semiconductor-solid electrolyte dual-mode gas sensor. By applying a bias current or voltage, the sensor can simultaneously generate two types of gas-sensitive signals, resistance and potential, significantly improving the selectivity and recognition accuracy of multiple gases (reference [1]). Although semiconductor-solid electrolyte dual-mode gas sensors have advantages in generating multi-dimensional gas-sensitive signals, when processing difficult-to-distinguish gas signals, they still need to rely on increasing the number of unit electrode groups or sensitive electrodes within the unit electrode groups to expand the signal dimension, thereby improving the gas recognition rate. Therefore, this method of increasing the dimension of the gas-sensitive signal increases the manufacturing cost and process complexity of the sensor to a certain extent, making it difficult to meet the application requirements of miniaturization and high integration.

[0004] [1] ZHANG H, ZHANG ZB, LI Z, et al. A chemiresistive-potentiometric multivariate sensor for discriminative gas detection[J]. NatureCommunications, 2023, 14(1): 3495. Summary of the Invention

[0005] To address the limitations of the aforementioned semiconductor-solid electrolyte dual-mode gas sensors, the present invention provides a current-modulated, multi-collector gas sensor. This improves the gas sensor's structure by introducing a multi-collector structure under the polarization effect of the bias current. This approach expands the gas-sensing signal dimension in a simple, low-cost, and low-power manner, providing a new solution for improving gas sensor detection accuracy.

[0006] Based on current modulation, the present invention introduces a multi-current collecting structure into the semiconductor-solid electrolyte dual-mode gas sensor. From the inflow end to the outflow end of the bias current, the potential polarity at each point in the sensitive electrode changes gradiently from positive to negative, thereby obtaining differentiated multi-dimensional resistance-potential signals and improving the accuracy of gas identification.

[0007] The present invention provides a multi-current structure gas sensor based on current modulation, comprising a solid electrolyte 1 and a unit electrode group.

[0008] The number of the unit electrode groups is one or more.

[0009] Each unit electrode group includes a sensitive electrode 2, a counter electrode 3 and a current collecting group 4, wherein at least one sensitive electrode 2 is provided and at least one counter electrode 3 is provided;

[0010] Alternatively, each unit electrode group includes a sensitive electrode 2 and a current collecting group 4, and the number of the sensitive electrodes 2 is at least two.

[0011] The unit electrode group is disposed on the surface of the solid electrolyte 1 .

[0012] The current collecting group 4 is composed of a plurality of current collectors. The current collecting group 4 is in contact with the sensitive electrode 2 and two adjacent current collectors are not in contact with each other.

[0013] The sensitive electrode 2 is a semiconductor gas-sensitive material, including but not limited to one or a composite of SnO2, ZnO, NiO or WO3; the counter electrode 3 is platinum, or other metal or semiconductor gas-sensitive materials.

[0014] The solid electrolyte 1 includes but is not limited to YSZ, GDC, ESB or NASICON.

[0015] In each unit electrode group, the number of current collectors contained in the current collecting group contacted by at least one sensitive electrode is ≥ 3. The current collectors are platinum or other metals.

[0016] In the same unit electrode group, select at least one sensitive electrode with 3 or more current collectors. Use the two current collectors on the same sensitive electrode as end current collectors 5 and 6. Apply a bias current I0 between these two end current collectors to change the polarization degree at different locations on the sensitive electrode, thereby generating differentiated multidimensional gas-sensing signals. A greater number of current collectors between the two end current collectors 5 and 6 contributes to the generation of a greater number of differentiated gas-sensing signals, thereby improving gas recognition efficiency.

[0017] The bias current I0 is a constant current with a value range of 0.1 nA to 1 A.

[0018] When multiple sensitive electrodes with a number of current collectors ≥ 3 are selected to apply bias current, two current collectors on the same sensitive electrode are used as end current collectors, and bias current is applied between the end current collectors. The bias currents applied to the end current collectors of different sensitive electrodes may be the same or different.

[0019] The bias current I0 is used to change the polarization degree at different positions of the sensitive electrode to generate differentiated multi-dimensional gas-sensing signals. In the same unit electrode group, the magnitude of the bias current I0 can be adjusted according to the properties of the sensitive electrode, and each sensitive electrode can be set with a different bias current.

[0020] The present invention calculates the potential response by monitoring the voltage V between the current collector of the sensitive electrode 2 and the counter electrode 3 or the voltage V between the current collector of the sensitive electrode 2 and the current collector of another sensitive electrode as the gas composition changes.

[0021] Furthermore, by monitoring the voltage difference ΔV between the two end current collectors 5 and 6 of the sensitive electrode 2 and the counter electrode 3 as the gas composition changes, or the voltage difference ΔV between the two end current collectors 5 and 6 and any current collector of the other sensitive electrode as the gas composition changes, the resistance response, R = ΔV / I0. A model is constructed using the potential response value of the current collector and the resistance response value of the sensitive electrode after applying the bias current I0 for gas detection and discrimination.

[0022] Furthermore, as a preference, the current collecting group 4 is arranged below the sensitive electrode 2 and is in contact with both the sensitive electrode 2 and the solid electrolyte 1 .

[0023] The method for preparing a multi-current collector structure gas sensor of the present invention, taking a multi-current collector sensor composed of a semiconductor oxide sensitive electrode, a metal platinum counter electrode, and three or more platinum current collectors as an example, includes the following steps:

[0024] Step 1: Set the size of the current collector in the current collecting group 4 to 0.5 mm × 4.5 mm, and the spacing between adjacent current collectors to 1 mm; set the counter electrode 3 to a circular electrode with a radius of 0.6 mm; customize the screen printing template according to the above dimensions, print the platinum paste on the upper surface of the solid electrolyte 1 by screen printing, and calcine at 1000°C for 30 min; after calcination, use platinum paste to connect the platinum wire to the current collector and the counter electrode 3, and calcine at 1000°C for 30 min.

[0025] Step 2: Weigh an appropriate amount of sensitive electrode powder and prepare it into a suspension with ethanol. The ratio of sensitive electrode to ethanol is 0.02 g:1 mL. Seal and stir the prepared suspension for 20 min and ultrasonically disperse it for 10 min to make the sensitive electrode powder more evenly suspended in ethanol. After preheating the solid electrolyte in an oven at 150°C for 20 min, use a spray pen to spray the evenly dispersed sensitive electrode powder suspension onto the top of the current collecting group 4 and sinter it at 600°C for 3 h to form the sensitive electrode 2.

[0026] Step 3: Connect the current collectors and counter electrode 3 in the current collection group 4 to the voltage test equipment respectively, and apply a bias current I0 between the end current collector 5 and the end current collector 6 to obtain or calculate the multi-dimensional differential resistance-potential signal generated by the sensor when the gas composition changes; the bias current I0 is a constant current with a value range of 0.1 nA to 1 A.

[0027] The method for gas detection and identification based on the multi-current structure gas sensor comprises the following steps:

[0028] Step 1: Connect the current collector and the counter electrode 3 in the current collecting group 4 to the voltage testing equipment respectively (or connect the current collector in the current collecting group 4 to any current collector in another sensitive electrode. The voltage of the current collector and the counter electrode 3 in the current collecting group 4 is described below as an illustrative example); select two current collectors as end current collectors 5 and 6, and apply a bias current I0 between the two end current collectors 5 and 6 to change the polarization degree at different positions of the sensitive electrode to generate differentiated multi-dimensional gas-sensing signals; the obtained multi-dimensional signals include potential signals and resistance signals:

[0029] The potential signals are: potential V1, potential V2, ... potential Vn, where n represents the number of current collectors;

[0030] The resistance signal is: R = ΔV / I0;

[0031] Step 2: Add standard gas to air to form a standard gas mixture with different concentration gradients in the concentration range of 10 ppb-2000 ppm, and obtain a multidimensional signal in the same manner as in step 1; calculate the potential and resistance response values ​​based on the multidimensional signal in the air atmosphere and the multidimensional signal in the mixed atmosphere;

[0032] Potential response value V 响应 =V a -V g ;

[0033] V a Indicates the voltage between the current collector and the counter electrode 3 in air atmosphere; V a1represents the voltage between the first current collector and the counter electrode 3, and so on, until V an , n represents the number of current collectors.

[0034] V g Indicates the voltage between the current collector and the counter electrode 3 under mixed atmosphere; V g1 represents the voltage between the first current collector and the counter electrode 3, and so on, until V gn , n represents the number of current collectors.

[0035] For the first current collector, its potential response value V 响应1 = V a1 - V g1 , and so on.

[0036] Resistance response value R 响应 = R a / R g ;

[0037] R a Indicates the resistance of the sensitive electrode in air atmosphere, R a = ΔV a / I0; where ΔV a It is the voltage difference between the two end current collectors and the counter electrode in air atmosphere, or the voltage difference between the two end current collectors and any current collector of the other sensitive electrode.

[0038] R g Indicates the resistance of the sensitive electrode in the mixed atmosphere, R g = ΔV g / I0. Where ΔV g It is the voltage difference between the two end current collectors and the counter electrode under mixed atmosphere, or the voltage difference between the two end current collectors and any current collector of the other sensitive electrode.

[0039] The above data were input into software (such as Origin software) for linear discriminant analysis (LDA). The input data included standard gas type column, multidimensional potential response value column (i.e. V 响应1 ~ V 响应n ) and the resistance response value column (R 响应 ); After the data input is completed, in the "Settings" interface of the linear discriminant analysis, select the "Linear" discriminant function, check "Canonical Discriminant Analysis", and after the settings are completed, click "Confirm" to obtain the confusion matrix of the linear discriminant analysis of multiple gases;

[0040] Step 3: For the gas to be tested, obtain the potential signal and resistance signal according to the method in step 1, and calculate the potential response value and resistance response value. In the data input interface of step 2, check "Predict test data" and enter the potential response value and resistance response value to be tested to obtain the type of gas to be tested.

[0041] The standard gas includes one or more of 2-ethylhexanol (2-EH), dioctyl phthalate (DOP), ethanol (CH3CH2OH), acetone (CH3COCH3), benzene (C6H6), toluene (C7H8), propane (C3H8), methane (CH4), ethylene (C2H4), hydrogen (H2), ammonia (NH3), nitrogen dioxide (NO2), nitric oxide (NO) or carbon monoxide (CO).

[0042] The beneficial effects of the present invention are embodied in:

[0043] 1. Under the polarization effect of the bias current, the multi-current structure gas sensor of the present invention enables the sensitive electrodes at different polarization positions to produce differentiated gas-sensitive responses. At the same time, the multi-current structure is used to obtain multi-dimensional resistance-potential signals, which can significantly improve the selectivity for different gases and enhance the reliability and accuracy of gas identification in complex environments.

[0044] 2. Compared with the semiconductor-solid electrolyte dual-mode gas sensor, when the number of sensitive electrodes or unit electrode groups is the same, the multi-current collector structure gas sensor based on current modulation of the present invention can increase at least one-dimensional gas-sensitive signal for each additional current collector. By further increasing the number of current collectors in the current collector group, multi-dimensional recognition of gas-sensitive signals can be achieved using a single sensitive electrode or unit electrode group, which is more conducive to the miniaturization and high integration of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a structural schematic diagram of a multi-current collecting structure gas sensor based on current modulation; the numbers in the figure are: 1 solid electrolyte, 2 sensitive electrode, 3 counter electrode, 4 current collecting group, 5 and 6 end current collectors.

[0046] Figure 2 Schematic diagram of the structure of a semiconductor-solid electrolyte dual-mode gas sensor with a single sensitive electrode or a unit electrode group; numbers in the figure are: 1 solid electrolyte, 2 sensitive electrode, 3 counter electrode, 5 and 6 end current collectors.

[0047] from Figure 1 and Figure 2It can be seen that the multi-current structure gas sensor based on current modulation of the present invention can generate at least four-dimensional gas-sensitive signals (potential signals: V1, V2, Vn, resistance signal: R, (R= (V1-Vn) / I0)), while the semiconductor-solid electrolyte dual-mode gas sensor of a single sensitive electrode or unit electrode group can only generate a two-dimensional gas-sensitive signal (potential signal: V, resistance signal: R) at most; by increasing the number of collectors in the collector group 4, the multi-current structure gas sensor based on current modulation can generate higher-dimensional gas-sensitive signals, thereby further improving the ability to identify different gases.

[0048] Figure 3 This is a structural schematic diagram of a seven-current structure gas sensor based on current modulation; the numbers in the figure are: 1 solid electrolyte, 2 sensitive electrode, 3 counter electrode, 4 current collecting group, 5 and 6 end current collectors, 7, 8, 9, 10 and 11 current collectors.

[0049] Figure 4 This is a structural schematic diagram of a two-current collector structure gas sensor based on current modulation; the numbers in the figure are: 1 solid electrolyte, 2 sensitive electrode, 3 counter electrode, 5 and 6 end collectors.

[0050] Figure 5 a is a gas-sensitive response curve of a seven-collector structure gas sensor based on current modulation to 20 ppm hydrogen when a bias current of 0.3 μA is applied. Figure 5 b is the resistance-potential response value of a seven-collector structure gas sensor based on current modulation to 20 / 50 / 100 / 200 ppm hydrogen when a bias current of 0.3 μA is applied. Figure 5 Figure c is the gas-sensitive response curve of a seven-collector structure gas sensor based on current modulation to 20 / 50 / 100 / 200 ppm hydrogen when a 0.3 μA bias current is applied. Figure 5 (a) It can be seen that the sensor generates two types of gas-sensitive signals, including seven-dimensional potential signals and one-dimensional resistance signals. Under the polarization effect of the bias current (I0 = 0.3 μA), the baseline potential of the seven current collectors in the air presents a transition state from positive to negative. After the introduction of 20 ppm H2, the gas-sensitive response sizes and change trends of the seven current collectors show great differences. The gas-sensitive response behaviors of the end current collectors 5 and 6 are opposite (potential 1 and potential 7), while the resistance change shows the gas-sensitive response behavior of a typical n-type semiconductor, that is, the resistance decreases. Further, combined with Figure 5(b) and (c) show that most potential responses and resistance responses are linearly related to the logarithmic concentration of hydrogen, and the sensitivity of different current collectors to hydrogen (linear fitting slope) varies. Overall, under the polarization effect of the bias current, each current collector has significant differences in response size, response change trend, and sensitivity, which greatly enriches the gas-sensitive response information of the sensor. Combined with the resistance response, it expands the dimension of the gas-sensitive signal and has great potential in identifying different gases.

[0051] Figure 6 Figure 6 shows the confusion matrix of a seven-collector structure gas sensor based on current modulation for classification prediction of seven gases when a bias current of 0.3 μA is applied. When there are seven collectors under the sensitive electrode 2, the seven collectors form collector group 4, and a total of eight-dimensional gas-sensing signals (7V_1R, seven potential signals V1, V2, V3, V4, V5, V6, and V7, and one resistance signal R (R=(V1-V7) / I0, I0 = 0.3 μA)) are obtained. In the figure, the classification prediction accuracy of ethylene (C2H4), carbon monoxide (CO), acetone (C3H6O), methane (CH4), ammonia (NH3), hydrogen (H2), and nitrogen dioxide (NO2) are 100%, 100%, 100%, 100%, 50%, 100%, and 100%, respectively. The average classification prediction accuracy of the sensor for the seven gases is 92.86%.

[0052] Figure 7 Figure 3 is the confusion matrix of a current-modulated two-current collector structure gas sensor for classification prediction of seven gases when a bias current of 0.3 μA is applied. When there are only two current collectors under the sensitive electrode 2, the two current collectors are used as end current collectors 5 and 6, and current collector group 4 cannot be formed. A total of three-dimensional gas-sensing signals (2V_1R, two potential signals V1 and V2, and one resistance signal R (R=(V1-V2) / I0, I0 = 0.3 μA)) are obtained. In the figure, the classification prediction accuracy of ethylene (C2H4), carbon monoxide (CO), acetone (C3H6O), methane (CH4), ammonia (NH3), hydrogen (H2), and nitrogen dioxide (NO2) are 75%, 50%, 50%, 25%, 50%, 75%, and 100%, respectively. The average classification prediction accuracy of the sensor for the seven gases is 60.71%.

[0053] contrast Figure 6 、 Figure 7 It can be found that compared with the two-current structure with the same bias current, the seven-current structure gas sensor with bias current has an improved classification prediction accuracy of 52.95% for seven gases, and the gas recognition ability is greatly improved. DETAILED DESCRIPTION

[0054] The technical solution of the present invention is described in detail below through specific examples. The following examples are implemented under the premise of the technical solution of the present invention, and provide detailed implementation plans and specific operating processes. The following examples are only used to help understand the implementation methods and core ideas of the present invention, but the scope of protection of the present invention is not limited to the following examples.

[0055] Example 1:

[0056] In this embodiment, the seven-collector structure gas sensor based on current modulation is as follows: Figure 3 As shown, SnO2 is used as the sensitive electrode, precious metal Pt is used as the counter electrode, YSZ is used as the solid electrolyte, and precious metal Pt is used as the current collector. The preparation steps are as follows:

[0057] (1) The size of the seven current collectors in the current collecting group 4 was set to 0.5 mm × 4.5 mm, and the spacing between adjacent current collectors was 1 mm; the counter electrode 3 was set to a circular electrode with a radius of 0.6 mm; a screen printing template was customized according to the above dimensions, and platinum paste was printed on the upper surface of the YSZ commercial solid electrolyte 1 by screen printing, and calcined at 1000°C for 30 min; after calcination, the platinum wire was connected to the current collector and the counter electrode 3 with platinum paste, and calcined at 1000°C for 30 min.

[0058] (2) Weigh an appropriate amount of commercial SnO2 nanopowder and prepare it into a suspension with ethanol. The ratio of SnO2 nanopowder to ethanol is 0.02 g:1 mL. Stir the prepared suspension in a sealed container for 20 min and ultrasonically disperse it for 10 min to make the SnO2 nanopowder more evenly suspended in the ethanol. Preheat the YSZ solid electrolyte 1 in an oven at 150°C for 20 min, spray the evenly dispersed SnO2 nanopowder suspension onto the top of the current collecting group 4 with a spray pen, and sinter it at 600°C for 3 h to form a sensitive electrode 2. Place the prepared sensor in a quartz tube and prepare for gas sensing testing.

[0059] The seven-collector structure gas sensor based on current modulation in this embodiment can be used to identify multiple gas types, specifically including the following steps:

[0060] (1) The quartz tube containing the sensor was placed in a tubular muffle furnace. The operating temperature of the sensor was set to 450 °C, and the gas flow rate in the quartz tube was set to 200 sccm.

[0061] (2) If Figure 3As shown, a multi-channel data acquisition device is selected to collect voltage signals, and the seven current collectors in the current collection group 4 and the platinum wire on the counter electrode 3 are respectively connected to the seven voltage channels of the data acquisition; a source meter (current source) is used to apply a bias current of 0.3 μA (I0 = 0.3 μA) between the two end current collectors (current collector 5 and current collector 6) to obtain or calculate the multi-dimensional differential resistance-potential signal generated by the sensor when the gas composition changes; the obtained multi-dimensional signal can be divided into two categories: potential signal and resistance signal; the potential signal includes: potential V1, potential V2, potential V3, potential V4, potential V5, potential V6, potential V7; in Figure 3 Calculate the voltage difference ΔV between collector 5 and collector 6 1-7 , the resistance signal is R 1-7 (R 1-7 = ΔV 1-7 / I0, I0=0.3 μA); In this embodiment, a total of eight-dimensional gas-sensitive signals are obtained for gas identification, including seven-dimensional potential signals (potential V1, potential V2, potential V3, potential V4, potential V5, potential V6, potential V7) and one-dimensional resistance signal (resistance R 1-7 ).

[0062] (3) Gas sensitivity tests were performed using seven air mixtures with different concentrations: ethylene (C2H4: 50 / 100 / 200 / 500 ppm), carbon monoxide (CO: 50 / 100 / 200 / 500 ppm), acetone (C3H6O: 20 / 50 / 100 / 200 ppm), methane (CH4: 50 / 100 / 200 / 500 ppm), ammonia (NH3: 50 / 100 / 200 / 500 ppm), hydrogen (H2: 20 / 50 / 100 / 200 ppm), and nitrogen dioxide (NO2: 50 / 100 / 200 / 500 ppm). Each gas was tested three times at each concentration.

[0063] (4) The potential response is calculated as V 响应 = V a -V g (V a : The voltage between the current collector at the sensitive electrode 2 and the counter electrode 3 in air atmosphere, V g : The voltage between the current collector at the sensitive electrode 2 and the counter electrode 3 in the target gas atmosphere); the resistance response is calculated as: R 响应 =R a / R g (R a : Resistance of the sensitive electrode 2 in air atmosphere, R g : resistance of the sensitive electrode 2 in the target gas atmosphere).

[0064] (5) The eight-dimensional gas sensitive responses (including seven-dimensional potential response values ​​and one-dimensional resistance response values) of the seven-collection flow structure gas sensor based on current modulation (I0 = 0.3 μA) to seven gases are input into the Origin software for linear discriminant analysis (LDA). The input data is divided into a prediction model training set (prediction model construction) and a test set (prediction of the gas category to be tested) in a 2:1 manner. The input data of the training set includes: gas type column, seven-dimensional potential response value column and one-dimensional resistance response value column; the input data of the test set includes: seven-dimensional potential response value column and one-dimensional resistance response value column; in the "Input Data" interface of the linear discriminant analysis, check "Prediction Test Data", in the "Settings" interface, select the "Linear" discriminant function, check "Typical Discriminant Analysis", and after the settings are completed, the prediction classification results of the seven gases can be obtained, as shown in the following figure. Figure 6 As shown in Figure 3, the sensor's average prediction classification accuracy for the seven gases is 92.86%.

[0065] (6) For the two-current structure gas sensor with the same bias current (I0 = 0.3 μA), the gas prediction and recognition process is similar to the above process. The only difference is the change in the dimension of the input data. The input data of the training set includes: gas type column, two-dimensional potential response value column and one-dimensional resistance response value column; the input data of the test set includes: two-dimensional potential response value column and one-dimensional resistance response value column; Figure 7 As shown in the figure, the average classification prediction accuracy of the sensor for the seven gases is 60.71%.

[0066] The above description is merely an exemplary embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

[0067] Other technical information that helps to understand the invention:

[0068] [1] Yi Jianxin, Zhang Hong. A semiconductor-solid electrolyte dual-mode sensor and its application in gas identification [P]. Anhui Province: CN202010484970.9, 2022-01-14.

[0069] [2] ZHANG H, ZHANG ZB, LI Z, et al. A chemiresistive-potentiometric multivariate sensor for discriminative gas detection[J]. NatureCommunications, 2023, 14(1): 3495.

Claims

1. A current-modulated multi-current structure gas sensor, characterized by: The multi-current structure gas sensor includes a solid electrolyte and a unit electrode group; The unit electrode group is provided as one or more; Each unit electrode group includes a sensitive electrode, a counter electrode and a current collecting group, wherein the sensitive electrode is provided at least one and the counter electrode is provided at least one; Or each unit electrode group includes a sensitive electrode and a current collecting group, and the sensitive electrodes are provided in at least two; The unit electrode group is arranged on the surface of the solid electrolyte; The current collecting group is composed of a plurality of current collectors, the current collecting group is in contact with the sensitive electrode and two adjacent current collectors are not in contact with each other; In each unit electrode group, the number of current collectors contained in the current collecting group contacted by at least one sensitive electrode is ≥3; At least one sensitive electrode containing 3 or more current collectors is selected, and the two current collectors on the same sensitive electrode are used as end current collectors. A bias current I0 is applied between the end current collectors. The bias current I0 is used to change the polarization degree at different positions of the sensitive electrode to generate differentiated multi-dimensional gas-sensing signals.

2. The multi-current structure gas sensor according to claim 1, characterized in that: The sensitive electrode is a semiconductor gas-sensitive material; the counter electrode is platinum, or other metal or semiconductor gas-sensitive materials.

3. The multi-current structure gas sensor according to claim 1, characterized in that: The bias current I0 is a constant current with a value range of 0.1 nA~1 A.

4. The multi-current structure gas sensor according to claim 1 or 3, characterized in that: When multiple sensitive electrodes with a number of current collectors ≥ 3 are selected to apply bias current, two current collectors on the same sensitive electrode are used as end current collectors, and bias current is applied between the end current collectors. The bias currents applied to the end current collectors of different sensitive electrodes may be the same or different.

5. The multi-current structure gas sensor according to claim 1, characterized in that: The potential response is calculated by monitoring the voltage V between the current collector of the sensitive electrode and the counter electrode or the voltage V between the current collector of the sensitive electrode and the current collector of another sensitive electrode as the gas composition changes; By monitoring the change of the voltage difference ΔV between the two end current collectors and the counter electrode in the sensitive electrode, or the voltage difference ΔV between the two end current collectors and any current collector in the other sensitive electrode as the gas composition changes, the resistance response is calculated, R = ΔV / I0.

6. The multi-current structure gas sensor according to claim 5, characterized in that: A model is constructed using the potential response value of the current collector and the resistance response value of the sensitive electrode after applying the bias current I0, which is used for gas detection and discrimination.

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