Flexible gas flow sensor based on ion-conductive gel, preparation method and application

Abstract

This invention discloses a flexible gas flow rate sensor based on ion-conductive gel, its fabrication method, and its applications. Specifically, it includes blending a semiconductor active layer and a pore-forming agent; spin-coating and etching a porous semiconductor thin film onto an interdigitated electrode substrate; blending an ion-gel precursor solution; spin-coating or drop-casting the precursor solution; and photocrosslinking to prepare a gel thin film with ion-conducting properties. The sensor provided by this invention can achieve sensing responses to different inert gases and different gas flow rates at low power consumption, and can also be used for detecting human respiration via a Bluetooth testing module. It introduces airflow to regulate ion mobility and enhances the sensing performance of the device through a porous organic semiconductor thin film. The flexible sensor can adhere to the surface of other objects or the inner wall of airflow ducts. The device structure is simple and easily miniaturized, enabling the creation of millimeter-sized micro-sensors. It is suitable for mass production, low-power, and miniaturized devices.

Description

Technical Field

[0001] This invention belongs to the field of airflow detection and chemical sensor technology, specifically relating to a flexible gas flow rate sensor based on ion-conductive gel, its preparation method, and its application. Background Technology

[0002] Airflow sensing is a crucial function of the sensory systems of natural organisms, and airflow sensors are considered an important biomimetic recognition technology. In recent years, a series of airflow sensors with diverse sensing mechanisms have emerged, demonstrating broad application potential in fields such as respiratory monitoring, aircraft flight control, weather forecasting, coal mining, and electronic skin. However, traditional airflow sensors are limited by several persistent challenges, including material rigidity, structural complexity, low sensitivity, and high power consumption, thus hindering their practical application. Therefore, developing novel airflow sensors with high sensitivity, ease of fabrication, and low power consumption is of significant importance.

[0003] Most existing airflow sensors rely on classical sensing mechanisms, including temperature changes and mechanical deformation (such as pressure), generating identifiable signals (such as electrical and optical signals) due to minute changes in gas velocity. Based on these principles, researchers have proposed various sensors for detecting airflow changes, such as piezoresistive sensors, piezoelectric sensors, photoelectric sensors, triboelectric sensors, and calorimetric sensors. Among these, biomimetic sensors inspired by nature are considered one of the most promising for achieving efficient and non-destructive airflow monitoring. For example, a highly efficient piezoresistive fabric sensor based on spider cilia has been designed. Its working principle is that the fine carbon nanotube cilia grown in situ deform sufficiently under external force, resulting in a change in resistance. This sensor exhibits excellent sensing performance for trace airflow. However, it requires sufficient pressure to produce sufficient deformation, making it difficult to further reduce the detection limit, and requires complex microstructure design and modification of the sensitive material. At the same time, the linear correlation between velocity and pressure changes is poor, resulting in a non-linear change in the electrical signal of the airflow sensor. To improve the linear correlation, researchers have developed various strategies to improve the sensing and detection process, such as electroluminescence-assisted sensing. These new material designs and auxiliary technologies have significantly improved the overall performance of airflow velocity sensors, and they all share the common feature of being based on electronically conductive sensitive materials.

[0004] In contrast, ion-conductive gas flow sensors based on capacitive signals have received little attention. As an emerging sensor technology, solid-state ion-conductive sensors have attracted considerable attention due to their unique ion carrier characteristics, which endow them with unprecedented advantages, including a rich variety of carriers (such as inorganic and organic ions), diverse sensing mechanisms, and ion migration forming an electric double layer (which can reduce the device's operating voltage). This type of sensor holds promise for achieving high-performance gas flow sensing, particularly in obtaining lower detection limits and a linear relationship between the response signal and gas flow rate. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a flexible gas flow rate sensor based on ion-conductive gel, its preparation method and application, which solves the problems of sensitivity, power consumption and preparation of traditional gas flow sensors in the prior art.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A flexible gas flow sensor based on ion-conductive gel includes a substrate, interdigitated electrodes, a porous semiconductor layer, and an ion gel layer. The interdigitated electrodes are symmetrically disposed at both ends of the substrate, the porous semiconductor layer covers the interdigitated electrodes and the substrate, and the ion gel layer is disposed on the porous semiconductor.

[0008] The interdigitated electrodes are deposited onto the substrate using patterning or atomic deposition methods.

[0009] The porous semiconductor layer is prepared by adding a pore-forming agent and solution etching.

[0010] The ionogel layer material includes a blend of a photocrosslinkable polymer, a photocrosslinking agent, and an ionic liquid.

[0011] The fabrication method of a flexible gas flow sensor based on ion-conductive gel includes the following steps:

[0012] Step S1: Select the substrate material, symmetrically set interdigitated electrodes at both ends of the substrate, and perform surface cleaning treatment on the substrate.

[0013] In step S2, a blended solution of semiconductor material and pore-forming agent is spin-coated onto the substrate containing the electrode in step S1 to form an organic semiconductor thin film. Subsequently, the pore-forming agent in the semiconductor thin film is removed to obtain a porous semiconductor layer.

[0014] Step S3: The ion gel precursor mixture solution is drop-coated onto the porous semiconductor layer prepared in step S2, and after curing, an ion gel layer is formed to obtain the flexible gas flow sensor.

[0015] In step S2, the spin coating process parameters for the blend solution are: spin coating speed 200-6000 r / min, spin coating time 5-240 s, annealing temperature 30-120°C, and annealing time 10-120 min.

[0016] In step S3, the ion gel precursor mixture solution is drop-coated onto the porous semiconductor layer, flattened with a transparent sheet, left to stand, and cured with ultraviolet light. The transparent sheet is then peeled off to obtain the ion gel layer.

[0017] The ionogel layer material includes a blend of a photocrosslinkable polymer, a photocrosslinking agent, and an ionic liquid, wherein the ionic liquid accounts for 10-50% of the total content, and the ultraviolet light irradiation time is 30-100s.

[0018] The flexible gas flow rate sensor responds to gas with a certain flow rate, and the rate of change of the response is linearly related to the gas flow rate.

[0019] Applications of flexible gas flow rate sensors based on ion-conductive gels: These flexible gas flow rate sensors are used to simulate airflow detection in scenarios such as mine exploration and gas leak early warning, as well as in the fields of flexible wearable devices and biomedical devices.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. An ion-conductive polymer gel is used as the sensing layer of a flexible gas flow rate sensor. Ion conduction offers advantages such as a rich variety of charge carriers (e.g., inorganic and organic ions), diverse sensing mechanisms, ion migration forming an electrical double layer (which can reduce the device's operating voltage), and miniaturization and mass production capabilities. When gas at a certain flow rate reaches the surface of the sensing layer and is adsorbed and dissolved, the change in the viscosity of the solid electrolyte surface and the intensified interaction between the gas and the mobile ions inside the gel lead to a change in the ion carrier migration rate, which is reflected in the capacitance signal, thus enabling sensitive detection of gas flow rate.

[0022] 2. The added porous semiconductor layer can increase gas permeability and adsorption, reduce the detection limit of airflow, and improve the sensing performance of the device. The sensor of this invention can be flexible and can be attached to the surface of other objects or the inner wall of airflow ducts. The device structure is simple and easy to miniaturize, enabling the realization of millimeter-sized micro-sensors.

[0023] 3. It can be integrated into masks to test human breathing behavior, such as normal breathing, rapid breathing, and deep breathing. Simultaneously, the device can be applied to more practical scenarios, including setting gas flow rate thresholds to provide early warning of gas leaks, detecting airflow in mine exploration to detect potential cavities and collapses, and sensing and forecasting weather changes, thus broadening the application scope of gas flow rate sensors in daily life, industry, and medicine.

[0024] 4. The present invention has a simple process, low cost and low power consumption. The gas flow sensing achieved by the ion conduction mechanism has universality and is very easy to realize miniaturized device design and mass array device printing. It is suitable for scale-up production and in-depth optimization and has excellent application prospects in the field of intelligent sensing. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the flexible gas flow rate sensor structure of the ion-conductive gel of the present invention.

[0026] Figure 2 This is a flowchart illustrating the fabrication method of the flexible gas flow sensor based on the ion-conductive gel of the present invention.

[0027] Figure 3 The real-time response curves and linear fitting curves of the flexible gas flow rate sensor of the ion-conductive gel of this invention for nitrogen gas at different gas flow rates are shown.

[0028] Figure 4 This is a linear fitting curve of the response of the flexible gas flow sensor of the ion-conductive gel of the present invention to airflow from different directions.

[0029] Figure 5 This invention demonstrates the application of the flexible gas flow sensor based on the ion-conductive gel in terms of low power consumption and flexibility.

[0030] Figure 6 These are the real-time response curves and linear fitting curves of the flexible gas flow rate sensor of the ion-conductive gel of this invention for argon gas at different gas flow rates.

[0031] Figure 7 This is the real-time response curve of the flexible gas flow rate sensor of the ion-conductive gel of the present invention to different types of gases (air, oxygen, carbon dioxide) with the same gas flow rate.

[0032] Figure 8 This invention demonstrates the application of integrating a flexible gas flow sensor made of ion-conductive gel into a mask to detect human respiration.

[0033] In the figure, the labels are: 1-substrate; 2-interdigitated electrode; 3-porous semiconductor layer; 4-ionogel layer. Detailed Implementation

[0034] The structure and working process of the present invention will be further described below with reference to the accompanying drawings.

[0035] Capacitive devices are easy to fabricate, chemically stable, and have long lifespans. Furthermore, most ion-conducting materials are flexible polymers, providing irreplaceable advantages for flexible wearable sensors. For example, ionic liquids, important ion-conducting materials, are typically composed of organic cations and anions, possessing outstanding natural advantages such as high thermal stability, excellent ionic conductivity, tunable polarity, and flexibility. They can rapidly combine with other polymer matrices to form flexible polymer films, allowing sensors to be flexible and adhere to the surfaces of other objects or the inner walls of airflow ducts. In addition, the sensor device of this invention has a simple structure and is easy to miniaturize, enabling the fabrication and mass production of millimeter-sized microsensors. This allows for the detection of extremely low flow rates of gas molecules, providing important candidate materials for the miniaturization of flexible wearable devices. Therefore, developing highly efficient ion-conducting sensing materials holds promise for solving key bottleneck problems in airflow sensors.

[0036] A flexible gas flow sensor based on ion-conductive gel includes a substrate, interdigitated electrodes, a porous semiconductor layer, and an ion gel layer; the interdigitated electrodes are symmetrically disposed at both ends of the substrate, the porous semiconductor layer covers the electrodes and the substrate, and the ion gel layer is disposed on the porous semiconductor.

[0037] Specific embodiments, such as Figures 1 to 7 As shown:

[0038] A flexible gas flow sensor based on ion-conductive gel includes a substrate 1, interdigitated electrodes 2, a porous semiconductor layer 3, and an ion gel layer 4. The interdigitated electrodes 2 are symmetrically disposed at both ends of the substrate 1 and are used to drive the ion carrier formation circuit in the sensing layer. The porous semiconductor layer 3 covers the interdigitated electrodes and the substrate 1 and is used to drive the ion carrier formation circuit in the sensing layer. The ion gel layer 4 is disposed on the porous semiconductor and can adsorb inert gas molecules in the gas flow, thereby causing a change in ion mobility and enabling the device to have sensing characteristics.

[0039] The substrate is located at the bottom of the gas flow rate sensing device as a support layer for the device, and the material is one or more of the following: polyimide, polyethylene naphthalate (PEN), polyethylene terephthalate (PET) substrate, or polydimethylsiloxane, etc.

[0040] The interdigitated electrodes are deposited on the substrate using patterning or atomic deposition methods, and form ion conduction pathways by providing an external voltage during testing. The electrode material is one or more of conductive metals, conductive alloys, conductive metal oxides, carbon nanotubes, and conductive polymers such as poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, and the thickness of the electrodes at both ends is 30-100 nm.

[0041] The porous semiconductor layer is prepared by adding a pore-forming agent and solution etching. The semiconductor material is an intrinsically conductive or doped conjugated polymer semiconductor, such as one or more of conductive polyaniline (PANI), polypyridine, and polythiophene. The pore-forming agent includes inorganic and organic materials, such as easily decomposable inorganic materials like ammonium bicarbonate (NH4HCO3) and toner, and organic materials like polyvinyl alcohol and polymethyl methacrylate (PMMA). The concentration of the prepared blend solution is 2-5 mg / mL. After spin-coating the semiconductor layer (i.e., the organic semiconductor thin film), the pore-forming agent is dissolved using water, acid, or alkaline solutions, or directly decomposed by heating to obtain the porous semiconductor layer. The thickness of the porous semiconductor layer is 50-100 nm.

[0042] The ionogel layer material comprises a blend of a photocrosslinkable polymer, a photocrosslinking agent, and an ionic liquid. The ionogel layer is driven by an external voltage, causing directional migration of internal ions. The ionogel layer material includes one or more of the following: polyethylene glycol diacrylate (PEGDA) gel, polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) gel, 2-hydroxy-2-methylphenylacetone (HOMPP), and 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMIm:TFSI). The ionic liquid content is generally 10-50% to ensure suitable initial capacitance and sensing performance, avoid adhesion to the transparent sheet, and the illumination time is 30-100 seconds.

[0043] This flexible gas flow sensor, through the design of an ion-conducting solid gel layer and a two-dimensional organic porous semiconductor layer, achieves sensitive response to gases with different flow rates within a working voltage of ±2V. The device can respond to inert gases such as nitrogen, argon, and air with a certain flow rate; the rate of response change is linearly related to the gas flow rate. Simultaneously, the device can identify different gas flow directions, exhibiting extremely low detection limits and high sensitivity. Integrating this device into a face mask allows for real-time detection of human respiration via wired or wireless means. Using a flexible microchip as a substrate enables the fabrication of miniaturized flow sensors and provides an important candidate technology for mass-producing devices, offering a new sensing mechanism and technology for the field of biomimetic flow sensing.

[0044] The fabrication method of a flexible gas flow sensor based on ion-conductive gel includes the following steps:

[0045] Step S1: Select a flexible substrate material, symmetrically arrange interdigitated electrodes at both ends of the substrate, and use Ar / O plasma to clean the surface of the substrate.

[0046] Step S2: Spin-coat the blended solution of semiconductor material and pore-forming agent onto the substrate containing the electrode in step S1 to obtain an organic semiconductor thin film. Then, use an etchant to remove the pore-forming agent from the organic semiconductor thin film to obtain a porous semiconductor layer. The spin-coating speed is 200-6000 r / min, the spin-coating time is 2-240 s, and then the film is annealed at 30-120°C for 10-120 min in a glove box hot stage.

[0047] In this step, the semiconductor material used is an intrinsically conductive or doped conjugated polymer semiconductor, such as conductive PANI and poly(3-hexylthiophene-2,5-dimethyl) semiconductors, or one or more of these. The pore-forming agent includes inorganic and organic materials, such as easily decomposable inorganic materials like NH4HCO3 and carbon powder, and organic materials like polyvinyl alcohol and PMMA. The concentration of the prepared blend solution is 2-5 mg / mL. After spin-coating the semiconductor layer, the pore-forming agent is dissolved using water, acid, or alkaline solutions, or directly decomposed by heating to obtain a porous semiconductor layer. The thickness of the porous semiconductor layer is 50-100 nm.

[0048] Step S3: Drop the ion gel precursor mixture solution onto the porous semiconductor layer prepared in step S2, flatten it with a transparent sheet, let it stand for 10-120 seconds, then place it under a UV lamp for 10-120 seconds, and peel off the transparent sheet to obtain the ion gel layer.

[0049] In this step, the ionogel layer material used is one or more of a photocrosslinkable polymer, photocrosslinking agent, and ionic liquid, such as PEGDA gel, PVDF-HFP gel, HOMPP, and BMIm:TFSI ionic liquid. The proportion of ionic liquid is generally 10-50%, and the illumination time is 10-120 seconds.

[0050] Example 1: The flow rate of nitrogen gas was detected using a flexible sensor made of ion-conductive gel.

[0051] This embodiment 1 provides a flexible gas flow sensor based on an ion-conductive gel, comprising: a substrate 1, interdigitated electrodes 2, a porous semiconductor layer 3, and an ion gel layer 4. In this embodiment, the substrate 1 is made of a flexible PEN conductive electrode. The interdigitated electrodes 2 are made of indium tin oxide (ITO). The porous semiconductor layer 3 is preferably made of conductive polyaniline, with PMMA as the pore-forming agent, and acetic acid is used to remove the pore-forming agent from the semiconductor layer. The ion gel layer 4 is made of PEGDA gel, photocured using the photocrosslinking agent HOMPP, and with BMIm:TFSI as the ion carrier.

[0052] Specifically, the fabrication method of the flexible gas flow sensor based on ion-conductive gel in this example is as follows: Figure 2 As shown, it includes the following steps:

[0053] Step S1: In this example, a square glass plate with indium tin oxide as interdigitated electrodes is selected as the substrate, with a size of 1.5cm×1.5cm and an effective area of ​​5mm×5mm for the interdigitated electrodes. The substrate is cleaned using Ar / O plasma.

[0054] Step S2: A porous semiconductor layer is prepared on the clean interdigitated electrode obtained in Step S1 using spin coating. In this example, PANI and PMMA are dissolved in chloroform solution at a concentration of 5 mg / mL, and then the two solutions are mixed in a 1:1 volume ratio. Spin coating is then performed in an atmospheric environment at a rotation speed of 1000 r / min for 10 s and 2000 r / min for 50 s. The device with the spin-coated semiconductor layer is placed on a hot stage at 100°C for annealing for 60 min. After cooling, it is immediately immersed in acetic acid for 1 h. The immersed device is then cleaned with deionized water and dried with an air gun to obtain the porous semiconductor layer 3.

[0055] In step S3, PEGDA, HOMPP and BMIm:TFSI are mixed in a mass ratio of 2:1:1 to obtain a blend solution. Then, 0.2 μL of the solution is dropped onto the porous semiconductor layer 3 prepared in step S2 above. A transparent PET sheet with an area of ​​5 mm × 5 mm and a thickness of 10 μm is cut and placed on the solution to form a uniform thin layer by means of surface tension. After standing for 1 min, the device is irradiated with a 365 nm ultraviolet light for 40 s. Then, the transparent PET sheet is gently peeled off to obtain an ion gel layer 4 with a thickness of about 5 μm.

[0056] The flexible gas flow rate sensor based on ion-conductive gel provided in Example 1 was tested for gas flow rate sensing. The device's response to nitrogen gas at different flow rates and its ability to identify airflow from different directions were studied. Furthermore, the integration of the sensor into a mask for wireless monitoring of human respiration via Bluetooth module was investigated, demonstrating its promising application potential in the biomedical field.

[0057] The performance testing method is as follows: The device is fixed in a 1.8L metal chamber with stable humidity. A pipeline using high-purity nitrogen as the gas source is connected through an opening in the chamber, and the outlet is placed close to the sensing part of the device. The device is then connected to an external LCR meter via wires to test the capacitance signal. It should be noted that a gas flow meter is used to regulate the gas flow rate in the gas inlet pipeline, and a gas valve switch is installed between the flow meter and the metal chamber to facilitate control of the airflow entering the chamber.

[0058] Figure 3 These are the real-time response curves and linear fitting curves of the flexible gas flow rate sensor made of ion-conductive gel in Example 1 of this invention for nitrogen gas at different flow rates. It can be seen that the device response is stable, with significant differences in response between different flow rates. The detection limit is as low as 2.5 mL / min, and there is a good linear relationship between the response and the flow rate.

[0059] Figure 4 This is a linear fitting curve of the response of the flexible gas flow sensor made of ion-conductive gel in Embodiment 1 of the present invention to airflow from different directions. It can be seen that the device has good response to airflow in the 0°, 45° and 90° directions, and the slope of the response fitting line has slight differences, indicating that the sensor is suitable for detecting airflow at different angles.

[0060] Figure 5 This is an example of the application of the flexible gas flow sensor made of ion-conductive gel in Embodiment 1 of the present invention, demonstrating its low power consumption and flexibility. As can be seen, the device still exhibits a significant airflow response curve at a low operating voltage of 30mV. The device, based on a flexible PEN substrate, remains stable after being bent 200 times with a radius of 9mm, illustrating the device's low power consumption advantage and its application potential in the field of flexible wearables.

[0061] Example 2: Detection of different types of gas flow rates by a flexible sensor using ion-conductive gel.

[0062] To further demonstrate the universality of Example 1 in sensing the flow rate of different types of gases, Example 2 is identical to Example 1 except that the inert gas is changed to argon. The device preparation steps and testing conditions will not be described separately.

[0063] Figure 6These are the real-time response curves and linear fitting curves of the flexible gas flow rate sensor made of ion-conductive gel in Embodiment 2 of the present invention for argon gas at different flow rates. It can be seen that the device response is very stable and the linear relationship is good, indicating that this sensor can be used for argon gas flow rate detection.

[0064] Figure 7 These are the real-time response curves of the flexible gas flow rate sensor made of ion-conductive gel in Embodiment 2 of the present invention for different types of gases (air, oxygen, and carbon dioxide) at the same gas flow rate. These curves further demonstrate that the sensor can be stably and widely applied to the flow rate detection of various gases.

[0065] Example 3: Application of flexible sensor made of ion-conductive gel in respiratory detection.

[0066] To further demonstrate the feasibility of applying Example 1 in the field of flexible wearable electronics, Example 3 integrates a flexible gas flow sensor of ion-conductive gel into a mask and tests the real-time breathing curve of the subject via Bluetooth connection. The structure of the sensor used is the same as that in Example 1, and the preparation steps of the device will not be described separately.

[0067] Figure 8 This invention extends the application of the flexible gas flow sensor based on ion-conductive gel integrated into a mask for detecting human respiration, as described in Embodiment 1 of this invention. It includes a test diagram and actual response curves. Wireless connection via Bluetooth allows real-time viewing of the human respiration response curve on a mobile phone, expanding the application of this sensor in the biomedical and flexible wearable electronics fields.

[0068] The flexible gas flow sensor responds to air and inert gas with a certain flow rate, and the rate of change of the response is linearly related to the gas flow rate.

[0069] The device operates at a voltage within ±2V, enabling gas flow velocity sensing, and can operate at low voltages of 20-50mV. The gas flow sensing capability allows the device to respond to gases with a certain flow velocity, including nitrogen, argon, and air, while also identifying the flow direction. It exhibits extremely low detection limits and high sensitivity.

[0070] Applications of flexible gas flow rate sensors based on ion-conductive gels: These flexible gas flow rate sensors are used to simulate airflow detection in scenarios such as mine exploration and gas leak early warning, as well as in the fields of flexible wearable devices and biomedical devices.

[0071] With low power consumption, it can detect gas flow rates in the range of 1-150 mL / min, using a capacitance signal as the output signal to obtain a linear relationship between capacitance change and gas flow rate. The sensor can be fabricated as flexible, allowing it to adhere to other objects or the inner wall of airflow ducts; its simple structure and ease of miniaturization enable millimeter-sized microsensors. By equipping the device on a mask and connecting it to detection software via wired or Bluetooth wireless means, real-time and stable respiratory monitoring of the tested person can be achieved. This sensor can also be used to simulate applications of airflow detection in scenarios such as mine exploration and gas leak early warning.

[0072] The flexible gas flow sensor based on ion-conductive gel described in the embodiments of this invention enables the sensing of gas flow rate and detection of human respiration. This invention features a simple preparation process, strong versatility, and ease of mass production. Using ion-conductive materials as the main sensing layer, it achieves sensitive gas flow rate detection and compatibility with wearable electronic devices, providing a new technology for numerous applications such as real-time health monitoring, gas leak early warning, and mine exploration.

[0073] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product or device.

[0074] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0075] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0076] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0077] It should be understood that this solution is not limited to the specific embodiments described above. Devices and structures not described in detail herein should be understood as being implemented in a manner common to the art. Any person skilled in the art can make many possible variations and modifications to this solution, or modify it into equivalent embodiments, without departing from the scope of this solution, using the methods and techniques disclosed above. This does not affect the substantive content of this solution. Therefore, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this solution, without departing from its scope, still fall within the protection scope of this solution.

Claims

1. A flexible gas flow rate sensor based on ion-conductive gel, characterized in that: The device comprises a substrate, interdigitated electrodes, a porous semiconductor layer, and an ion gel layer. The interdigitated electrodes are symmetrically disposed at both ends of the substrate to drive the formation of ion carrier circuits in the sensing layer. The porous semiconductor layer covers the interdigitated electrodes and the substrate to increase gas permeability and adsorption, reducing the detection limit of the gas flow. The ion gel layer is disposed on the porous semiconductor to adsorb gas molecules in the gas flow, thereby causing changes in ion mobility and giving the device sensing characteristics. The ion gel layer material includes a blend of photocrosslinkable polymers, photocrosslinking agents, and ionic liquids. The ion gel layer is driven by an external voltage to induce directional migration of internal ions. This enables sensitive response to gases with different flow rates within a working voltage of ±2V, with the response rate of change showing a linear relationship with the gas flow rate, and simultaneously identifying the direction of different gas flow rates.

2. The flexible gas flow sensor based on ion-conductive gel according to claim 1, characterized in that: The interdigitated electrodes are deposited onto the substrate using patterning or atomic deposition methods.

3. The flexible gas flow rate sensor based on ion-conductive gel according to claim 1, characterized in that: The porous semiconductor layer is prepared by adding a pore-forming agent and solution etching.

4. A method for preparing a flexible gas flow sensor based on the ion-conductive gel of claim 1, characterized in that: Includes the following steps: Step S1: Select the substrate material, symmetrically set interdigitated electrodes at both ends of the substrate, and perform surface cleaning treatment on the substrate. Step S2: Spin-coat the blended solution of semiconductor material and pore-forming agent onto the substrate containing the electrode in step S1 to form an organic semiconductor thin film. Then remove the pore-forming agent from the semiconductor thin film to obtain a porous semiconductor layer. Step S3: The ion gel precursor mixture solution is drop-coated onto the porous semiconductor layer prepared in step S2, and after curing, an ion gel layer is formed to obtain the flexible gas flow sensor.

5. The method for fabricating a flexible gas flow sensor based on ion-conductive gel according to claim 4, characterized in that: In step S2, the spin coating process parameters for the blend solution are: spin coating speed 200-6000 r / min, spin coating time 5-240 s, annealing temperature 30-120°C, and annealing time 10-120 min.

6. The method for fabricating a flexible gas flow sensor based on ion-conductive gel according to claim 4, characterized in that: In step S3, the ion gel precursor mixture solution is drop-coated onto the semiconductor layer, flattened with a transparent sheet, left to stand, and cured with ultraviolet light. The transparent sheet is then peeled off to obtain the ion gel layer.

7. The method for fabricating a flexible gas flow sensor based on ion-conductive gel according to claim 6, characterized in that: The ionogel layer material includes a blend of a photocrosslinkable polymer, a photocrosslinking agent, and an ionic liquid, wherein the ionic liquid accounts for 10-50% of the total content, and the ultraviolet light irradiation time is 30-100s.

8. The method for fabricating a flexible gas flow sensor based on ion-conductive gel according to claim 4, characterized in that: The flexible gas flow rate sensor responds to gas with a certain flow rate, and the rate of change of the response is linearly related to the gas flow rate.

9. The application of the flexible gas flow sensor based on the ion-conductive gel of claim 1, characterized in that: This flexible gas flow velocity sensor is used to simulate airflow detection in scenarios such as mine exploration and gas leak early warning, as well as in the fields of flexible wearable devices and biomedical devices.

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