FET (Field Effect Transistor) configuration humidity-sensitive sensor for detecting humidity
Through the FET configuration moisture-sensitive sensor, using flexible substrate, ionic gel dielectric layer and graphene conductive contacts, the existing humidity sensors have solved the stability, response speed and accuracy problems, achieving high sensitivity and high accuracy humidity detection, suitable for wearable electronic devices.
Patent Information
- Application Number
- CN202420646584.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-01
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2034-04-01
AI Technical Summary
Existing humidity sensors have defects in stability, response speed, accuracy and environmental adaptability, especially the electrical humidity sensors lack elastic plastic deformation capabilities such as stretching and bending, which limits their application and detection accuracy.
Using FET configuration moisture-sensitive sensor, including flexible substrate, ionic gel dielectric layer, MoS2 humidity-sensitive film layer and graphene conductive contacts, the interdigital structure and conductive silver paste electrode can achieve high sensitivity and high accuracy humidity detection. .
It realizes high sensitivity, high accuracy and long life humidity detection, and is light and soft, suitable for wearable electronic devices, enhancing the accuracy and safety performance of humidity detection.
Smart Images
Figure CN222166930U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a FET-type humidity-sensitive sensor for detecting humidity, belonging to the technical field of humidity-sensitive sensors. Background Art
[0002] Surface humidity refers to the moisture content and humidity level on the surface of the skin, which plays an important role in human health and comfort. Surface humidity affects skin health. When the surface humidity is too low, the skin is prone to dryness, dehydration and other problems. Excessive surface humidity can easily cause skin infections and allergic reactions. Secondly, surface humidity is also closely related to temperature regulation. The human body regulates its body temperature by evaporating water from the skin surface. When the surface humidity is too high, the evaporation effect is hindered, and the temperature regulation will be affected, which may lead to excessive body temperature. Conversely, when the surface humidity is too low, evaporation is too fast, which can lead to low body temperature. Therefore, monitoring surface humidity can not only help to understand the moisture status of the skin in a timely manner and prevent the occurrence of skin problems, but also help people better understand their body temperature status and take timely adjustment measures. With the improvement of living standards, it is particularly important to develop more accurate and intelligent surface humidity monitoring devices for physical health.
[0003] At present, humidity sensors mainly include two categories: electrical and optical. Among them, optical humidity sensors mainly use physical principles and various characteristics of materials to convert the measured quantity into easy-to-handle quantities, so as to obtain more accurate, miniaturized and intelligent humidity sensors. However, this integrated optical humidity sensor still has some difficult problems to solve. For example, the stability of the humidity sensor is affected by the extremely large physical size of the device, and the stability is difficult to guarantee. In addition, the preparation process of this type of photonic crystal structure device is complicated, and it does not have the ability of elastic-plastic deformation such as stretching and bending, and has poor environmental adaptability. Electrical humidity sensors are reliable and stable, and the preparation process is simple, but electrical humidity sensors currently have the disadvantages of slow response speed and insufficient accuracy. At the same time, existing electrical humidity sensors also have the disadvantages of not having the ability of elastic-plastic deformation such as stretching and bending, and poor environmental adaptability.
[0004] Most current electrical humidity sensor research focuses on resistive and capacitive humidity sensors. Although resistive sensors are cheap and easy to manufacture, they have defects such as size limitations, small measurement range, and difficulty in integration. Capacitive humidity sensors can achieve smaller size, faster response, and better linearity, but the humidity hysteresis is large. The fundamental reason is that the resistive and capacitive humidity sensors are too simple in structure and too single in parameters. They can only rely on changes in resistivity and dielectric constant to reflect the influence of water molecules on humidity-sensitive materials, which restricts the sensor's accurate detection of humidity.
[0005] In order to meet the requirements of low cost, scalability, stability and CMOS compatibility for humidity sensors, a new type of sensor structure needs to be prepared. Summary of the invention
[0006] In view of the deficiencies in the prior art, the utility model provides a FET-type humidity-sensitive sensor for detecting humidity.
[0007] The technical solution of the utility model is as follows:
[0008] A FET-configured humidity sensor for detecting humidity comprises, from bottom to top, a flexible substrate and an ion gel dielectric layer; a conductive silver paste electrode is arranged at one end of the ion gel dielectric layer, and a MoS2 humidity sensitive film layer is arranged at the other end; and a graphene conductive contact is arranged on the MoS2 humidity sensitive film layer.
[0009] Preferably, according to the utility model, the number of the graphene conductive contacts is 2, which are respectively located at two ends above the MoS2 humidity sensitive film layer.
[0010] Further preferably, the graphene conductive contacts serve as a source and a drain respectively, and have an interdigitated structure.
[0011] Preferably, according to the present utility model, the conductive silver paste electrode is used as a grid electrode and has a sinusoidal structure.
[0012] Preferably, according to the present invention, the thickness of the FET-type humidity sensor is 0.9-1.1 mm.
[0013] Preferably, according to the present invention, the thickness of the ion gel dielectric layer is 9.05-10.05 μm.
[0014] Preferably, according to the present invention, the thickness of the MoS2 humidity sensitive thin film layer is 10 to 20 nm.
[0015] Preferably, according to the present invention, the material of the flexible substrate is PDMS, PET, PI, PEN, PU or TPU.
[0016] Preferably, according to the present invention, the material of the ion gel dielectric layer is a gel film of a mixture of a PS-PEO-PS triblock copolymer or a PS-PMMA-PS triblock copolymer and an ionic liquid.
[0017] Preferably, according to the present invention, the ionic liquid includes but is not limited to BMIM-TFSI, DEME-TFSI, and EMIM-TFSI.
[0018] The beneficial effects of the utility model are:
[0019] 1. The FET configuration humidity sensor provided by the utility model innovatively adopts a FET structure with a source, a gate and a drain, with graphene conductive contacts as the source and drain respectively, and a conductive silver paste electrode as the gate. Due to the existence of the gate structure, the difference in the current signal generated by the MoS2 humidity sensitive film layer absorbing water is more obvious, which can achieve a higher sensitivity response to humidity and expand the humidity measurement range, and at the same time has the advantages of high accuracy, high reliability, and long life.
[0020] 2. The FET configuration humidity sensor provided by the utility model uses an ion gel dielectric layer as the gate dielectric. Through the double electric layer principle, it can complete the regulation work that traditional FET transistors require a large voltage to complete by providing a micro voltage, thereby improving the safety performance of the device during use.
[0021] 3. The FET configuration humidity sensor provided by the utility model has the advantages of being light, thin, and soft, and is convenient to wear and use. It can be widely used in wearable electronic devices and as "electronic skin" in medical and health devices.
[0022] 4. The utility model improves the structure of the interdigital electrode, increases the contact area between the humidity sensitive film layer and the air environment, and enhances the accuracy of the detection data. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a structural schematic diagram of the FET-type humidity sensor of the utility model.
[0024] Figure 2 It is a three-dimensional structural schematic diagram of the FET configuration humidity sensor of the utility model.
[0025] Figure 3 The utility model is a circuit diagram of the FET configuration humidity sensor when in use.
[0026] In the figure, 1. flexible substrate, 2. ion gel dielectric layer, 3. MoS2 humidity sensitive film layer, 4. graphene conductive contact, 5. conductive silver paste electrode, 6. first source surface, 7. second source surface. DETAILED DESCRIPTION
[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0028] Example 1
[0029] like Figure 1 , 2 As shown, a FET configuration humidity sensor for detecting humidity includes, from bottom to top, a flexible substrate 1 and an ion gel dielectric layer 2; a conductive silver paste electrode 5 is provided on one end of the ion gel dielectric layer 2, and a MoS2 humidity sensitive film layer 3 is provided on the other end; two graphene conductive contacts 4 are provided on the MoS2 humidity sensitive film layer 3, and the graphene conductive contacts 4 are respectively located at two ends above the MoS2 humidity sensitive film layer 3.
[0030] The thickness of the ion gel dielectric layer 2 is 10 μm, the thickness of the MoS2 humidity sensitive film layer 3 is 20 nm, and the overall thickness of the FET configuration humidity sensitive sensor is 1 mm.
[0031] The graphene conductive contacts 4 serve as the source and drain respectively, and present an interdigitated structure, wherein the graphene conductive contact 4 close to the conductive silver paste electrode 5 is the source, and the graphene conductive contact 4 far from the conductive silver paste electrode 5 is the drain; the conductive silver paste electrode 5 serves as the gate, and presents a sinusoidal structure.
[0032] The material of the flexible substrate 1 is PET; the material of the ion gel dielectric layer is PS-PEO-PS triblock copolymer.
[0033] Example 2
[0034] like Figure 3 As shown, when the FET configuration humidity sensor of the utility model is working, the graphene conductive contact 4 as the source is connected to the first source meter 6 and the conductive silver paste electrode 5 as the gate; the graphene conductive contact 4 as the drain is connected to the second source meter 7 and the graphene conductive contact 4 as the source; the first source meter 6 and the second source meter 7 both use the graphene conductive contact 4 as the source as a low level.
[0035] The first source meter 6 provides a voltage to the conductive silver paste electrode 5 as the gate, so that the polarized charge in the ion gel dielectric layer 2 affects the conduction process of the semiconductor film, thereby controlling the change of the conduction current. In different temperature ranges, applying different voltage values to the first source meter 6 can simulate the relative humidity changes of the human body at different temperatures, thereby realizing the function of monitoring the relative humidity of the human body surface.
[0036] A voltage is applied to the graphene conductive contact 4 as the drain electrode through the second source meter 7, and the carriers in the MoS2 humidity sensitive film layer 3 are continuously accumulated on the surface, thereby conducting and generating a conduction current. When the FET configuration humidity sensor of the utility model is in a humid environment, the MoS2 humidity sensitive film layer 3 absorbs water molecules, causing the resistivity to decrease, thereby measuring an increased current value in the second source meter 7.
Claims
1. A FET-type humidity sensor for detecting humidity, characterized in that: From bottom to top, it includes a flexible substrate and an ion gel dielectric layer; a conductive silver paste electrode is arranged at one end of the ion gel dielectric layer, and a MoS2 humidity sensitive film layer is arranged at the other end; and a graphene conductive contact is arranged on the MoS2 humidity sensitive film layer.
2. The FET-type humidity sensor for detecting humidity according to claim 1, characterized in that: The number of the graphene conductive contacts is 2, which are respectively located at the two ends above the MoS2 humidity sensitive film layer.
3. The FET-type humidity sensor for detecting humidity as claimed in claim 2, characterized in that: The graphene conductive contacts serve as a source electrode and a drain electrode respectively, and are in an interdigitated structure.
4. The FET-type humidity sensor for detecting humidity according to claim 1, characterized in that: The conductive silver paste electrode serves as a grid electrode and has a sinusoidal structure.
5. The FET-type humidity sensor for detecting humidity according to claim 1, characterized in that: The thickness of the FET configuration humidity sensor is 0.9-1.1 mm.
6. The FET-type humidity sensor for detecting humidity according to claim 1, characterized in that: The thickness of the ion gel dielectric layer is 9.05-10.05 μm.
7. The FET-type humidity sensor for detecting humidity according to claim 1, characterized in that: The thickness of the MoS2 humidity sensitive thin film layer is 10-20 nm.