An ionic gel sensor device with self-powered humidity sensing function and a preparation method thereof

Abstract

A kind of ion gel sensor device with self-powered humidity sensing function and its preparation method belong to humidity sensor field, including the following steps: step 1. Di-vinyl benzene and tetra (3-mercapto propionic acid) pentaerythritol ester (PETMP) are added to methanol and tetrahydrofuran at room temperature to form a solution;Step 2. A certain amount of polyionic liquid and benzoin dimethyl ether are added to the solution;Step 3. A certain amount of solution is dropped on the interdigital electrode;Step 4. The gel solution on the interdigital electrode is treated by ultraviolet light;Step 5. After completion, it is packaged and stored. The pressure sensor device shows good sensitivity under different humidity, and has self-powered ability, and the element can be well used for the detection of breathing and other actions.

Description

Technical Field

[0001] This invention belongs to the field of humidity sensor and its fabrication technology, specifically relating to an ion gel sensor device with self-powered humidity sensing function and its fabrication method. Background Technology

[0002] The demands of industrial automation, environmental monitoring, healthcare, intelligent systems, and the Internet of Things, along with the development of new materials and technologies, have driven research in the sensor field, providing a foundation for solving practical problems, advancing scientific progress, and promoting social development. These fields require not only measurements of humidity and other parameters but also accurate measurements while considering factors such as sensor size, thus increasing the demand for novel sensors.

[0003] One feasible method for monitoring various signals is to use ion gels to fabricate sensors. These ion gels generally possess properties such as small size, high flexibility, portability, and wearability. The ion gel in this invention is a network-structured material formed by cross-linking divinylbenzene and pentaerythritol tetrakis(3-mercaptopropionic acid) (PETMP) with a polyionic liquid under 365nm ultraviolet light irradiation and 2,2-dimethoxy-2-phenylacetophenone as a photocatalyst. Under these conditions, the carbon-carbon double bonds in divinylbenzene can be opened and cross-linked with the thiol groups of pentaerythritol tetrakis(3-mercaptopropionic acid). Furthermore, other thiol groups of pentaerythritol tetrakis(3-mercaptopropionic acid) can connect to more divinylbenzene, thus forming a network structure through cyclic linking. When this structure receives a humidity signal, its internal structure will absorb or release water molecules. The absorbed water will increase the ionic conductivity inside the gel, causing a change in its impedance. As an emerging material, ion gel has the properties of both ionic liquids and gels, ensuring its electrical properties while giving it the flexibility and adsorption of gels. Due to its small size, it is highly competitive for measuring precise and complex environments. At the same time, it is inexpensive, does not require expensive equipment for preparation, is easy to integrate, and can be made into portable miniaturized devices. It also has the ability to generate its own electricity, eliminating the need for external power supply, further saving on material and volume requirements. Summary of the Invention

[0004] To address the performance issues of ionogel humidity sensors, this invention proposes a method for fabricating an ionogel sensor with self-powered humidity sensing functionality, comprising the following steps:

[0005] Step 1. Divinylbenzene and pentaerythritol tetrakis(3-mercaptopropionic acid) (PETMP) are added to methanol and tetrahydrofuran at room temperature to form a solution;

[0006] Step 2. Add a certain amount of polyionic liquid and benzoin dimethyl ether to the solution;

[0007] Step 3. Drop an appropriate amount of solution onto the interdigitated electrode;

[0008] Step 4. Treat the gel solution on the interdigitated electrodes with ultraviolet light;

[0009] Step 5. After completion, package and save the file.

[0010] Furthermore, in step 1, the divinylbenzene has a concentration of 50%, and its ratio with the PETMP in step 1 and the polyionic liquid in step 2 is 2:1:1, while the ratio of methanol to tetrahydrofuran is 1:1.

[0011] Furthermore, in step 1, the divinylbenzene has a concentration of 50%, and its ratio with the PETMP in step 1 and the polyionic liquid in step 2 is 1:1:1, while the ratio of methanol to tetrahydrofuran is 1:1.

[0012] Furthermore, the wavelength of the ultraviolet light in step 4 is 365 nm, and the reaction time is 90-120 minutes.

[0013] An ion gel sensor device with self-powered humidity sensing function is prepared by the above method.

[0014] An application of an ionogel sensor device with self-powered humidity sensing function, wherein the ionogel sensor device has a self-powered function and does not require an external power source.

[0015] The beneficial effects of this invention are as follows: This invention solves the performance problem of ion gel humidity sensor devices, enabling the sensor device to have a smaller size, lower cost, and self-powered function, etc. By synthesizing a new type of ion gel, a self-powered humidity sensor device with better sensitivity and stability is provided, which is suitable for monitoring human physiological signals such as respiration.

[0016] This invention uses divinylbenzene and PETMP for reaction, which is low-cost and simple to prepare. The prepared device has good sensitivity and small size, and has self-powered characteristics. It can effectively detect some humidity signals and human respiratory signals. Attached Figure Description

[0017] Figure 1 The moisture absorption characteristic curve of the test element described in this invention is tested when switching between 11% and 97% relative humidity;

[0018] Figure 2 The response and recovery curves of the test element described in this invention under different relative humidities;

[0019] Figure 3 The impedance-time curve of the test element described in this invention under exhaled airflow at the human nose;

[0020] Figure 4 The humidity-voltage response curves of the test element described in this invention under different polarization times at 5V DC voltage and 97% relative humidity are shown.

[0021] Figure 5 The humidity-voltage response curves of the test element described in this invention under different polarization times at 5V DC voltage and 11% relative humidity are shown. Detailed Implementation

[0022] To make the technical means and objectives of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0023] A method for preparing an ion gel sensor device with self-powered humidity sensing function includes the following steps: Step 1: Methanol and tetrahydrofuran are mixed in a volume ratio of 1:1, and then divinylbenzene and pentaerythritol tetrakis(3-mercaptopropionic acid) ester (PETMP) are added to the mixed solution of methanol and tetrahydrofuran in a molar mass ratio of 1:1 using a dropper.

[0024] Step 2: Weigh out a small amount of benzoin dimethyl ether as a photocatalyst and a polyionic liquid with the same molar mass as PETMP using a balance, add them to the solution and mix thoroughly until there is no solid residue in the solution.

[0025] Step 3: Transfer the mixed solution to the interdigitated electrode using a 4μl pipette and react under 365nm ultraviolet light for 90-120 minutes, avoiding other light sources during the reaction.

[0026] Step 4: Store the solidified interdigital electrodes away from light.

[0027] To achieve good humidity sensing performance, the divinylbenzene in step 1 should have a concentration of 50%, and its ratio with the PETMP in step 1 and the polyionic liquid in step 2 should be 2:1:1, while the ratio of methanol to tetrahydrofuran should be 1:1.

[0028] To achieve the best power generation performance, the divinylbenzene in step 1 has a concentration of 50%, and its ratio with the PETMP in step 1 and the polyionic liquid in step 2 is 1:1:1, while the ratio of methanol to tetrahydrofuran is 1:1.

[0029] An ion gel sensor with self-powered humidity sensing function is prepared by the method described above. The invention uses conventional planar interdigitated electrodes with an alumina substrate, measuring 10 mm in length, 5 mm in width, and approximately 1 mm in thickness. The interdigitated carbon electrodes have a width of 100–400 μm, an interdigital spacing of 50–500 μm, and 5–7 pairs of interdigitated electrodes.

[0030] An application of an ionogel sensor device with self-powered humidity sensing function, wherein the ionogel sensor device has a self-powered function and does not require an external power source.

[0031] Example 1

[0032] The humidity-sensing ionic gel material used in this invention was prepared by dissolving 53.0 mg divinylbenzene, 50.0 mg PETMP, 42 mg polyionic liquid, and 4.0 mg benzoin dimethyl ether in a mixed solvent of 0.2 mL tetrahydrofuran and 0.2 mL methanol (the ratio of divinylbenzene, PETMP, and polyionic liquid was 1:1:1). After mixing evenly, 4 μl of the gel solution was dropped onto the interdigitated electrode using a pipette, and a crosslinking reaction was carried out under 365 nm ultraviolet light for 120 min. After the reaction was completed, the material was stored in the dark.

[0033] Example 2

[0034] The preparation of the ionogel material with the best hydrovoltaic power generation properties involved in this invention involves dissolving 53.0 mg divinylbenzene, 100.0 mg PETMP, 84 mg polyionic liquid, and 4.0 mg benzoin dimethyl ether in a mixed solvent of 0.3 mL tetrahydrofuran and 0.3 mL methanol (the ratio of divinylbenzene, PETMP, and polyionic liquid is 2:1:1). After mixing evenly, 4 μl of the gel solution is dropped onto the interdigitated electrode using a pipette, and a crosslinking reaction is carried out under 365 nm ultraviolet light for 120 min. After the reaction is completed, the material is stored in the dark.

[0035] Example 3

[0036] The performance testing of the sensitive element was conducted according to methods disclosed in the art. Specifically, the humidity sensing element was tested using a KEYSIGHT E4990A Impedance Analyzer. Different relative humidity environments were prepared using saturated salt solutions, with relative humidity levels including 11% (LiCl), 33% (MgCl2), 54% (Mg(NO3)2), 75% (NaCl), 85% (KCl), and 97% (KNO3). The impedance between the interdigitated electrode pins of the element prepared in Example 1 was read under 1 volt AC current at different relative humidity equilibrium states. The moisture absorption characteristic curve of the element during the transition between 11% and 97% relative humidity was tested. Figure 1The response and recovery curves of the original component under different relative humidities were tested. Figure 2 ), and the impedance-time variation curve of the component under the exhaled airflow at the human nose ( Figure 3 ).

[0037] Example 4

[0038] The performance of the sensitive element was tested according to methods disclosed in the art. Specifically, the humidity sensing element was tested using a Keithley 2450 SourceMeter. Different relative humidity environments were prepared using saturated salt solutions, with relative humidity levels including 11% (LiCl), 33% (MgCl2), 54% (Mg(NO3)2), 75% (NaCl), 85% (KCl), and 97% (KNO3). The voltage between the interdigitated electrode pins of the element prepared in Example 2 was read under different relative humidity equilibrium states. Humidity-voltage response curves were obtained under 5V DC voltage and 97% relative humidity for different polarization times. Figure 4 Humidity-voltage response curves at different polarization times under 5V DC voltage and 11% relative humidity ( Figure 5 ).

[0039] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing an ion gel sensor device with self-powered humidity sensing function, characterized in that, Includes the following steps: Step 1. Divinylbenzene and pentaerythritol tetrakis(3-mercaptopropionic acid) (PETMP) are added to methanol and tetrahydrofuran at room temperature to form a solution; Step 2. Add a certain amount of polyionic liquid and benzoin dimethyl ether to the solution; Step 3. Drop an appropriate amount of solution onto the interdigitated electrode; Step 4. Treat the gel solution on the interdigitated electrodes with ultraviolet light; Step 5. After completion, package and save the file.

2. The method for preparing an ion gel sensor device with self-powered humidity sensing function according to claim 1, characterized in that, In step 1, the divinylbenzene concentration is 50%, and the ratio of divinylbenzene to pentaerythritol tetrakis(3-mercaptopropionic acid) (PETMP) in step 1 and the polyionic liquid in step 2 is 2:1:1, while the ratio of methanol to tetrahydrofuran is 1:

1.

3. The method for preparing an ion gel sensor device with self-powered humidity sensing function according to claim 1, characterized in that, In step 1, the divinylbenzene concentration is 50%, and its ratio with pentaerythritol tetrakis(3-mercaptopropionic acid) ester (PETMP) in step 1 and the polyionic liquid in step 2 is 1:1:1, while the ratio of methanol to tetrahydrofuran is 1:

1.

4. The method for preparing an ion gel sensor device with self-powered humidity sensing function according to claim 1, characterized in that, The ultraviolet light used in step 4 is 365 nm, and the reaction time is 90-120 minutes.

5. An ionogel sensor device with self-powered humidity sensing function, characterized in that, It is prepared by the method described in any one of claims 1 to 4, and the prepared ion gel sensor has a self-powered function and does not require an external power source.

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