A paper-based humidity sensor and a printing preparation method

Abstract

The application discloses a paper-based humidity sensor and a printing preparation method, and relates to the technical field of humidity sensors. The paper-based humidity sensor comprises a paper base, two groups of lower electrodes are arranged on the paper base and are centrally symmetrical, and lead wires are arranged above the paper base. The printing preparation method of the paper-based humidity sensor comprises five steps of pre-preparing a substrate, laying lower electrodes, applying a humidity-sensitive material, mounting lead wires and laying upper electrodes. The paper-based humidity sensor adopts a concave design, so that the connection between devices is more stable, the reliability is higher, and the device is stable after long-term use and is not prone to loosening. In addition, the paper-based humidity sensor does not add lead in the production and manufacturing process, so that the safety and environmental protection of the production and manufacturing of the paper-based humidity sensor are ensured. Meanwhile, the production raw materials are simple and visible, the production cost is low, the paper-based humidity sensor can be accepted by the majority of producers, can be mass-produced, and is convenient to popularize and use.

Description

Technical Field

[0001] This invention relates to the field of humidity sensor technology, and in particular to a paper-based humidity sensor and its printing preparation method. Background Technology

[0002] A method for fabricating a paper-based flexible humidity sensor, disclosed in CN108680615A, includes: spin-coating polyamic acid (PAA) onto a paper substrate, heating and curing the substrate on a heated stage, growing a silver layer on the cured paper substrate using an in-situ silver growth method, and forming a flexible humidity sensor based on the paper substrate using blue film photolithography. This invention utilizes the hygroscopic properties of paper to manufacture a paper-based flexible humidity sensor using a simple process. It allows for large-scale production, is low-cost, has a simple and environmentally friendly fabrication process, and exhibits high sensitivity.

[0003] The paper-based flexible humidity sensor prepared by the above method has poor stability during use, the connection between devices is prone to loosening after long-term use, resulting in poor reliability and short service life, which makes it inconvenient for promotion and use. Summary of the Invention

[0004] The purpose of this invention is to provide a paper-based humidity sensor and a printing preparation method, which can solve the problems of poor stability, loosening of connections between devices after long-term use, poor reliability, and short service life.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a paper-based humidity sensor, comprising a paper substrate, two sets of lower electrodes arranged in a centrally symmetrical manner on the paper substrate, a lead wire arranged above the paper substrate, two sets of circular grooves formed on the lead wire, a humidity-sensitive material disposed on the top of the lower electrodes, the humidity-sensitive material being disposed at the circular grooves on the lead wire, and an upper electrode being installed on the top of the lead wire.

[0006] Preferably, both the humidity-sensitive material and the upper electrode are provided with recesses, adopting a concave design, which makes the connection between the devices more stable and reliable. It is stable after long-term use and is not prone to loosening. In addition, no lead is added in the production and manufacturing process of this paper-based humidity sensor, thereby ensuring the safety and environmental protection of the production and manufacturing of the paper-based humidity sensor. At the same time, the raw materials are simple and readily available, the production cost is low, which can be accepted by a wide range of producers, can be mass-produced, and is easy to promote and use.

[0007] Preferably, the moisture-sensitive material has a circular hole on its top to facilitate the installation of leads.

[0008] A method for printing and preparing a paper-based humidity sensor, comprising the following steps;

[0009] S1. Prefabricated substrate: Low-density cellulose paper is selected as the substrate. The low-density cellulose paper substrate is then cut into a rectangle. The low-density cellulose paper substrate is then placed in a container containing acetone, ethanol and deionized water for ultrasonic cleaning. After ultrasonic cleaning, it is taken out and placed in a drying oven for drying at a temperature of 40-80 degrees Celsius. After drying, it is taken out for use.

[0010] S2. Laying the lower electrodes: Flatten the low-density cellulose paper substrate obtained in S1, and then glue and fix two lower electrodes on it, keeping a certain distance between the two lower electrodes to form a concave shape.

[0011] S3. Apply moisture-sensitive material; Apply moisture-sensitive material to the low-density cellulose paper substrate and the lower electrode obtained in S2. During the application process, retain the concave design in the middle, and then dry until the coating cools and sets.

[0012] S4. Install the lead wire; After the moisture-sensitive material is coated and cooled to set, open two sets of circular grooves on its surface. The depth of the circular grooves should be such that the lower electrode is exposed. Then install the lead wire inside the circular grooves, so that one end of the lead wire is fixed to the top of the lower electrode and the other end is connected to the power supply.

[0013] S5. Laying the upper electrode: After installing the lead wire in S4, glue and fix the upper electrode in the pre-reserved concave area on S4, so that the upper electrode is located between the two sets of lead wires and in the pre-reserved concave groove on S4. When the ambient humidity changes, the capacitance of the humidity-sensitive element changes accordingly. That is, when the relative humidity increases, the humidity-sensitive capacitance increases, and vice versa. The resulting paper-based humidity sensor not only has a fast response, rapid reaction, and high sensitivity, but also good dynamic response, strong corrosion resistance, reliable operation, low cost, and simple production process. By using low-density cellulose paper as the substrate, it has good flexibility and can be used in different humidity detection environments, increasing the application range of this paper-based humidity sensor. In addition, by adding humidity-sensitive material, when the ambient humidity changes, the capacitance of the humidity-sensitive element changes accordingly. That is, when the relative humidity increases, the humidity-sensitive capacitance increases, and vice versa, making the paper-based humidity sensor more rapid and sensitive.

[0014] Preferably, in step S1, the substrate is made into a rectangle of 4 cm × 2 cm with a paper thickness of 0.05 cm.

[0015] Preferably, in S1, the ultrasonic cleaning involves an ultrasonic dispersion power of 100-700W and an ultrasonic duration of 5-20 minutes.

[0016] Preferably, the distance between the two lower parts in S2 is 2-3 centimeters.

[0017] Preferably, the humidity-sensitive material in S3 is a thin-film capacitor whose dielectric constant changes with humidity due to its hygroscopic electrolyte material.

[0018] Preferably, the drying temperature in step S3 is 25-40 degrees Celsius, and the drying time is 5-10 minutes.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] (1) The paper-based humidity sensor uses a paper substrate, a lower electrode, leads, a humidity-sensitive material and an upper electrode in combination. The concave design makes the connection between the devices more stable and more reliable. It is stable after long-term use and is not easy to loosen. In addition, no lead is added in the production and manufacturing process of the paper-based humidity sensor, thus ensuring the safety and environmental protection of the production and manufacturing of the paper-based humidity sensor. At the same time, the raw materials are simple and readily available, the production cost is low, which can be accepted by a wide range of producers, can be mass-produced, and is easy to promote and use.

[0021] (2) The paper-based humidity sensor is manufactured by printing through five steps: prefabricating a substrate, laying the lower electrode, coating the humidity-sensitive material, installing the lead wire and laying the upper electrode. The paper-based humidity sensor can not only respond quickly and react rapidly, but also has high sensitivity. It also has good dynamic response, strong corrosion resistance, reliable operation, low cost and simple production process.

[0022] (3) The printing preparation method of the paper-based humidity sensor uses low-density cellulose paper as the substrate, which has good flexibility and can be used in different humidity detection environments, thus increasing the application range of the paper-based humidity sensor. In addition, by adding humidity-sensitive materials, the capacitance of the humidity-sensitive element changes when the ambient humidity changes. That is, when the relative humidity increases, the humidity-sensitive capacitance increases, and vice versa, making the paper-based humidity sensor more responsive and sensitive. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0024] Figure 1 This is a perspective view of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of the present invention.

[0026] Reference numerals: 1. Paper substrate; 2. Lower electrode; 3. Lead wire; 4. Humidity-sensitive material; 5. Upper electrode. Detailed Implementation

[0027] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0028] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0029] In the description of this invention, terms such as greater than, less than, and exceeding are understood to exclude the stated number, while terms such as above, below, and within are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0030] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0031] Example 1:

[0032] Please see Figure 1-2 This invention provides a technical solution: a paper-based humidity sensor, comprising a paper substrate 1, two sets of lower electrodes 2 arranged symmetrically on the paper substrate 1, a lead wire 3 arranged above the paper substrate 1, and two sets of circular grooves formed on the lead wire 3. A humidity-sensitive material 4 is arranged on the top of the lower electrodes 2, and the humidity-sensitive material 4 is located in the circular grooves on the lead wire 3. An upper electrode 5 is installed on the top of the lead wire 3. Both the humidity-sensitive material 4 and the upper electrode 5 are provided with recesses. The concave design makes the connection between the devices more stable, more reliable, and stable after long-term use, and less prone to loosening. In addition, no lead is added during the production and manufacturing process of this paper-based humidity sensor, thereby ensuring the safety and environmental protection of the production and manufacturing of this paper-based humidity sensor. At the same time, the raw materials are simple and readily available, the production cost is low, which can be accepted by a wide range of producers, can be mass-produced, and is easy to promote and use. A circular hole is formed on the top of the humidity-sensitive material 4 to facilitate the installation of the lead wire 3.

[0033] A method for printing and preparing a paper-based humidity sensor includes the following steps: Step 1: Pre-fabrication of a substrate; selecting low-density cellulose paper as the substrate, then cutting the low-density cellulose paper substrate into a rectangular shape, then placing the low-density cellulose paper substrate in a container filled with acetone, ethanol, and deionized water for ultrasonic cleaning, then removing it and placing it in a drying oven for drying at 40 degrees Celsius, and then taking it out for later use; Step 2: Laying down the lower electrodes; flattening the low-density cellulose paper substrate obtained in Step 1, and then attaching and fixing two lower electrodes on it, maintaining a certain distance between the two lower electrodes to form a concave shape; Step 3: ... 3. Applying Moisture-Sensitive Material: Apply moisture-sensitive material to the low-density cellulose paper substrate and lower electrode obtained in step 2, retaining the concave design in the middle during the coating process, and then dry until the coating cools and sets. 4. Installing Leads: After the moisture-sensitive material has cooled and set, open two sets of circular grooves on its surface, the depth of which extends to expose the lower electrode. Then install leads inside the circular grooves, fixing one end of the lead to the top of the lower electrode and connecting the other end to the power supply. 5. Laying the Upper Electrode: After installing the leads in step 4, glue and fix the upper electrode to the concave area reserved in step 4, so that the upper electrode is... Located between the two sets of leads and in the recessed groove reserved in step four, the capacitance of the humidity-sensitive element changes with the ambient humidity. Specifically, the capacitance increases with increasing relative humidity and decreases with decreasing relative humidity. This results in a paper-based humidity sensor that not only responds quickly and efficiently with high sensitivity, but also exhibits good dynamic response, strong corrosion resistance, reliable operation, low cost, and simple manufacturing process. By using low-density cellulose paper as the substrate, it possesses excellent flexibility, making it suitable for various humidity detection environments and expanding the sensor's application range. Furthermore, the addition of humidity-sensitive materials enhances the sensor's ability to detect changes in ambient humidity. When humidity changes, the capacitance of the humidity-sensitive element changes accordingly. That is, when the relative humidity increases, the capacitance of the humidity-sensitive element increases, and vice versa, making the paper-based humidity sensor more responsive and sensitive. In step one, the substrate is made into a rectangle of 4 cm × 2 cm with a paper thickness of 0.05 cm. In step one, the ultrasonic cleaning is performed with an ultrasonic dispersion power of 100 and an ultrasonic duration of 5 minutes. In step two, the distance between the two substrates is 2 cm. In step three, the humidity-sensitive material is a thin-film capacitor with a dielectric constant that changes with humidity, which is a hygroscopic electrolyte material. In step three, the drying temperature is 25 degrees Celsius and the drying time is 5 minutes.

[0034] Example 2;

[0035] Please see Figure 1-2This invention provides a technical solution: a paper-based humidity sensor, comprising a paper substrate 1, two sets of lower electrodes 2 arranged symmetrically on the paper substrate 1, a lead wire 3 arranged above the paper substrate 1, and two sets of circular grooves formed on the lead wire 3. A humidity-sensitive material 4 is arranged on the top of the lower electrodes 2, and the humidity-sensitive material 4 is located in the circular grooves on the lead wire 3. An upper electrode 5 is installed on the top of the lead wire 3. Both the humidity-sensitive material 4 and the upper electrode 5 are provided with recesses. The concave design makes the connection between the devices more stable, more reliable, and stable after long-term use, and less prone to loosening. In addition, no lead is added during the production and manufacturing process of this paper-based humidity sensor, thereby ensuring the safety and environmental protection of the production and manufacturing of this paper-based humidity sensor. At the same time, the raw materials are simple and readily available, the production cost is low, which can be accepted by a wide range of producers, can be mass-produced, and is easy to promote and use. A circular hole is formed on the top of the humidity-sensitive material 4 to facilitate the installation of the lead wire 3.

[0036] A method for printing and preparing a paper-based humidity sensor includes the following steps: Step 1: Pre-fabrication of a substrate; selecting low-density cellulose paper as the substrate, cutting the low-density cellulose paper substrate into a rectangle, then placing the low-density cellulose paper substrate in a container filled with acetone, ethanol, and deionized water for ultrasonic cleaning, removing it after ultrasonic cleaning and placing it in a drying oven for drying at 60 degrees Celsius, and then removing it for later use; Step 2: Laying down the lower electrodes; flattening the low-density cellulose paper substrate obtained in Step 1, and then attaching and fixing two lower electrodes on it, maintaining a certain distance between the two lower electrodes to form a concave shape; Step 3: ... Step 1: Applying Moisture-Sensitive Material; Apply the moisture-sensitive material to the low-density cellulose paper substrate and lower electrode obtained in Step 2, retaining a concave design in the middle during the coating process, and then dry until the coating cools and sets; Step 4: Installing Leads; After the moisture-sensitive material has cooled and set, open two sets of circular grooves on its surface, the depth of the circular grooves should be enough to expose the lower electrode, and then install the leads inside the circular grooves, fixing one end of the lead to the top of the lower electrode and connecting the other end to the power supply; Step 5: Laying the Upper Electrode; After the lead components installed in Step 4 are installed, glue and fix the upper electrode to the concave area reserved in Step 4, so that the upper electrode is positioned on both... The leads are positioned between the leads and in the recessed groove reserved in step four. When the ambient humidity changes, the capacitance of the humidity-sensitive element changes accordingly. That is, when the relative humidity increases, the capacitance increases, and vice versa. The resulting paper-based humidity sensor not only has a fast response, rapid reaction, and high sensitivity, but also good dynamic response, strong corrosion resistance, reliable operation, low cost, and simple manufacturing process. By using low-density cellulose paper as the substrate, it has excellent flexibility and can be used in different humidity detection environments, increasing the application range of this paper-based humidity sensor. In addition, by adding humidity-sensitive materials, when the ambient humidity changes... When the relative humidity changes, the capacitance of the humidity-sensitive element changes accordingly. That is, when the relative humidity increases, the capacitance of the humidity-sensitive element increases, and vice versa, making the paper-based humidity sensor more responsive and sensitive. In step one, the substrate is made into a rectangle of 4 cm × 2 cm with a paper thickness of 0.05 cm. In step one, the ultrasonic cleaning is performed with an ultrasonic dispersion power of 400 W and an ultrasonic duration of 12 minutes. In step two, the distance between the two substrates is 2.5 cm. In step three, the humidity-sensitive material is a thin-film capacitor with a dielectric constant that changes with humidity, which is a hygroscopic electrolyte material. In step three, the drying temperature is 32 degrees Celsius and the drying time is 7 minutes.

[0037] Example 3;

[0038] Please see Figure 1-2This invention provides a technical solution: a paper-based humidity sensor, comprising a paper substrate 1, two sets of lower electrodes 2 arranged symmetrically on the paper substrate 1, a lead wire 3 arranged above the paper substrate 1, and two sets of circular grooves formed on the lead wire 3. A humidity-sensitive material 4 is arranged on the top of the lower electrodes 2, and the humidity-sensitive material 4 is located in the circular grooves on the lead wire 3. An upper electrode 5 is installed on the top of the lead wire 3. Both the humidity-sensitive material 4 and the upper electrode 5 are provided with recesses. The concave design makes the connection between the devices more stable, more reliable, and stable after long-term use, and less prone to loosening. In addition, no lead is added during the production and manufacturing process of this paper-based humidity sensor, thereby ensuring the safety and environmental protection of the production and manufacturing of this paper-based humidity sensor. At the same time, the raw materials are simple and readily available, the production cost is low, which can be accepted by a wide range of producers, can be mass-produced, and is easy to promote and use. A circular hole is formed on the top of the humidity-sensitive material 4 to facilitate the installation of the lead wire 3.

[0039] A method for printing and preparing a paper-based humidity sensor includes the following steps: Step 1: Pre-fabrication of a substrate; selecting low-density cellulose paper as the substrate, then cutting the low-density cellulose paper substrate into a rectangle, then placing the low-density cellulose paper substrate in a container filled with acetone, ethanol, and deionized water for ultrasonic cleaning, then removing it and placing it in a drying oven for drying at 80 degrees Celsius, and then taking it out for later use; Step 2: Laying down the lower electrodes; flattening the low-density cellulose paper substrate obtained in Step 1, and then attaching and fixing two lower electrodes on it, maintaining a certain distance between the two lower electrodes to form a concave shape; Step 3: ... 3. Applying Moisture-Sensitive Material: Apply moisture-sensitive material to the low-density cellulose paper substrate and lower electrode obtained in step 2, retaining the concave design in the middle during the coating process, and then dry until the coating cools and sets; 4. Installing Leads: After the moisture-sensitive material has cooled and set, open two sets of circular grooves on its surface, the depth of the circular grooves should be enough to expose the lower electrode, and then install leads inside the circular grooves, fixing one end of the lead to the top of the lower electrode and connecting the other end to the power supply; 5. Laying the Upper Electrode: After the lead components installed in step 4 are installed, glue and fix the upper electrode to the concave area reserved in step 4, so that the upper electrode is positioned on... Between the two sets of leads, located in the recessed groove reserved in step four, the capacitance of the humidity-sensitive element changes with the ambient humidity. Specifically, the capacitance increases with increasing relative humidity and decreases with decreasing relative humidity. This results in a paper-based humidity sensor that not only responds quickly and efficiently with high sensitivity, but also exhibits good dynamic response, strong corrosion resistance, reliable operation, low cost, and simple manufacturing process. By using low-density cellulose paper as the substrate, it possesses excellent flexibility, making it suitable for various humidity detection environments and expanding the sensor's application range. Furthermore, the addition of humidity-sensitive materials allows the capacitance to change with varying ambient humidity levels. When the relative humidity changes, the capacitance of the humidity-sensitive element changes accordingly. That is, when the relative humidity increases, the capacitance of the humidity-sensitive element increases, and vice versa, making the paper-based humidity sensor more responsive and sensitive. In step one, the substrate is made into a rectangle of 4 cm × 2 cm with a paper thickness of 0.05 cm. In step one, the ultrasonic cleaning is performed with an ultrasonic dispersion power of 700 W and an ultrasonic duration of 20 minutes. In step two, the distance between the two substrates is 3 cm. In step three, the humidity-sensitive material is a thin-film capacitor with a dielectric constant that changes with humidity, which is a hygroscopic electrolyte material. In step three, the drying temperature is 40 degrees Celsius and the drying time is 10 minutes.

[0040] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for printing and preparing a paper-based humidity sensor, characterized in that, Includes the following steps; S1. Prefabricated substrate: Low-density cellulose paper is selected as the substrate. The low-density cellulose paper substrate is then cut into rectangles. The low-density cellulose paper substrate is then placed in a container containing acetone, ethanol and deionized water for ultrasonic cleaning. After ultrasonic cleaning, it is taken out and placed in a drying oven for drying at a temperature of 40-80 degrees Celsius. After drying, it is taken out for use. S2. Laying the lower electrodes: Flatten the low-density cellulose paper substrate obtained in S1, and then glue and fix two lower electrodes on it, keeping a certain distance between the two lower electrodes to form a concave shape. S3. Apply moisture-sensitive material; A moisture-sensitive material is coated on the low-density cellulose paper substrate and the lower electrode obtained in S2. During the coating process, the concave design in the middle is retained, and then the coating is dried until it cools and sets. S4. Install the lead wire; After the moisture-sensitive material is coated and cooled to set, open two sets of circular grooves on its surface. The depth of the circular grooves should be such that the lower electrode is exposed. Then install the lead wire inside the circular grooves, so that one end of the lead wire is fixed to the top of the lower electrode and the other end is connected to the power supply. S5. Lay the upper electrode; After installing the lead wire in S4, stick and fix the upper electrode in the pre-reserved concave area on S4, so that the upper electrode is located between the two sets of lead wires and in the pre-reserved concave groove on S4. When the ambient humidity changes, the capacitance of the humidity-sensitive element changes accordingly. That is, when the relative humidity increases, the humidity-sensitive capacitance increases, and vice versa.

2. The printing preparation method of a paper-based humidity sensor according to claim 1, characterized in that: The substrate in S1 is a rectangle measuring 4 cm × 2 cm, with a paper thickness of 0.05 cm.

3. The printing preparation method of a paper-based humidity sensor according to claim 2, characterized in that: In S1, the ultrasonic cleaning process involves an ultrasonic dispersion power of 100-700W and an ultrasonic duration of 5-20 minutes.

4. The printing preparation method of a paper-based humidity sensor according to claim 3, characterized in that: The distance between the two lower electrodes in S2 is 2-3 cm.

5. The printing preparation method of a paper-based humidity sensor according to claim 4, characterized in that: The humidity-sensitive material in S3 is a thin-film capacitor whose dielectric constant changes with humidity, and is a hygroscopic electrolyte material.

6. The printing preparation method of a paper-based humidity sensor according to claim 4, characterized in that: The drying temperature in S3 is 25-40 degrees Celsius, and the drying time is 5-10 minutes.

7. A paper-based humidity sensor, prepared using the printing preparation method according to any one of claims 1-6.

Images