Flexible temperature sensor and preparation method thereof

Abstract

The invention relates to a flexible temperature sensor and a preparation method thereof. The sensor is composed of a flexible substrate, a contact electrode, a power supply electrode, a thin film packaging layer and a Rhine system organic active layer, the contact electrode and the power supply electrode are respectively fixed on the flexible substrate, the Rhine system organic active layer covers the contact electrode and the power supply electrode, the thin film packaging layer is arranged on the surface of the Rhine system organic active layer, and the thin film packaging layer covers the power supply electrode. And the temperature change can be effectively sensed. A contact electrode and a power supply electrode of the sensor adopt a micron channel type electrode, a four-finger electrode or an interdigital electrode, and the channel size of an electrode active layer is 20 * 5 [mu] m. The Reyline system organic active layer is composed of a Rylene group and an imide group, an electrode and the organic active layer are formed on the surface of the flexible substrate through oxygen plasma treatment, vacuum deposition and coating processes, and finally the high-performance flexible temperature sensor is obtained. In addition, the invention further provides three electrode structures and technological methods, and it is ensured that the sensor has high sensitivity and stability.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to a flexible temperature sensor and a preparation method thereof. Background Art

[0002] With the development of flexible electronics, flexible temperature sensors are finding widespread application in smart wearable devices, wearable medical monitoring, smart homes, and environmental monitoring. Traditional temperature sensors are mostly made of rigid materials like metal and ceramics. These materials are susceptible to damage when subjected to high-intensity deformation or bending, and are not adaptable to various complex flexible application scenarios. Therefore, the development of flexible and high-performance temperature sensors is a pressing need in the current technological field.

[0003] Existing flexible temperature sensors mostly use conductive polymers or metal films as their conductive materials, but these sensors still have certain performance limitations. For example, they can suffer from poor temperature responsiveness, poor stability, and potential performance degradation after prolonged use. Especially for temperature sensing requiring highly accurate accuracy, conventional flexible materials often lack sufficient stability and response speed.

[0004] Linoline-based organic materials have become an important research direction for temperature sensor materials due to their adjustable band gap width, excellent conductivity, chemical stability and adaptability to flexible substrates. Summary of the Invention

[0005] The present invention provides a flexible temperature sensor and its preparation method. The sensor comprises a flexible substrate, a contact electrode, a power electrode, a thin-film encapsulation layer, and a rylene-based organic active layer. The contact electrode and power electrode are respectively fixed to the flexible substrate, and the rylene-based organic active layer covers the contact electrode and power electrode. The thin-film encapsulation layer is applied on the surface of the rylene-based organic active layer, effectively sensing temperature changes. The contact and power electrodes of the sensor utilize micron-channel electrodes, four-finger electrodes, or interdigitated electrodes, with the electrode active layer channel dimensions measuring 20 × 5 μm. The rylene-based organic active layer is composed of rylene and imide groups and has long conjugated chains, which contribute to the sensor's temperature sensing performance. The electrodes and organic active layer are formed on the surface of the flexible substrate through oxygen plasma treatment, vacuum deposition, and coating processes, ultimately resulting in a high-performance flexible temperature sensor. Furthermore, the present invention provides three electrode structures and process methods to ensure the sensor's high sensitivity and stability.

[0006] The flexible temperature sensor described in the present invention is composed of a flexible substrate (4), a contact electrode (2), a power electrode (3), a thin film encapsulation layer (5) and a linotype organic active layer (1). The contact electrode (2) and the power electrode (3) are respectively fixed on the flexible substrate (4), the contact electrode (2) and the power electrode (3) are covered with the linotype organic active layer (1), and the thin film encapsulation layer (5) is covered on the linotype organic active layer (1). The contact electrode (2) and the power electrode (3) are composed of micron channel type electrodes, four-finger electrodes or interdigitated electrodes, and the micron channel type electrode has a channel size of 20×5μm; the contact electrode (2) and the power electrode (3) are composed of six groups of parallel electrodes. The Rylene system organic active layer (1) comprises an organic semiconductor material containing a Rylene group and / or an imide group, which is an organic oligomer or a high molecular polymer; the Rylene group has a rigid conjugated structure composed of a benzene ring or a naphthalene ring, and the imide group is a -C(=O)-NH- structural unit, and the two can be located in the main chain or the side chain, or bridged by a conjugated structure to form an electron transport / donor channel; the thin film encapsulation layer (5) is polyimide, epoxy resin, silicone rubber, polyurethane, polyester film, fluorinated polymer, polyethylene terephthalate, thermoplastic polyurethane or carbon nanotube / graphene, and the contact electrode (2) and the power electrode (3) are Ag materials.

[0007] The method for manufacturing the flexible temperature sensor is carried out according to the following steps: Micron channel electrode flexible temperature sensor: a. Using the flexible substrate (4) as a processing carrier, first performing an oxygen plasma activation treatment on the surface of the flexible substrate (4); b. Electrode fabrication: A micron-channel contact electrode (2) and a power electrode (3) with a channel size of 20×5 μm are deposited on the surface of the flexible substrate (4) obtained in step a by vacuum deposition. The electrode material is Ag material, and a stable conductive layer is formed by continuous deposition; c. Active layer and encapsulation layer coating: The coated organic active layer (1) of the linoline system is coated by a single variable speed coating method with an initial speed of 1000 rpm for 30 seconds, uniformly covering the contact electrode (2) and the power electrode (3) obtained in step b, and then coating the surface of the coated organic active layer (1) of the linoline system with a thin film encapsulation layer (5).

[0008] The method for manufacturing the flexible temperature sensor is carried out according to the following steps: Four-finger electrode flexible temperature sensor: a. Using the flexible substrate (4) as a processing carrier, first performing an oxygen plasma activation treatment on the surface of the flexible substrate (4); b. Electrode fabrication: On the surface of the flexible substrate (4), a four-finger electrode is deposited as a contact electrode (2) using a vacuum deposition method. The structure of the four-finger electrode is designed to be four parallel and equally spaced finger-shaped contact electrodes (2). The electrode material is Ag material, and a stable conductive layer is formed by continuous deposition; c. Coating of the active layer and the encapsulation layer: The coated organic active layer (1) of the linoline system is coated using a single variable speed coating method with an initial speed of 1000 rpm for 30 seconds, uniformly covering the four-finger electrode as the contact electrode (2), and then coating the surface of the coated organic active layer (1) of the linoline system with a thin film encapsulation layer (5).

[0009] The method for manufacturing the flexible temperature sensor is carried out according to the following steps: Interdigitated electrode flexible temperature sensor: a. Using the flexible substrate (4) as a processing carrier, first performing an oxygen plasma activation treatment on the surface of the flexible substrate (4); b. Electrode fabrication: creating an intercalation structure on the surface of a flexible substrate (4), and continuously depositing intercalation electrodes as contact electrodes (2) and power electrodes (3) by vacuum evaporation, wherein the electrode material is Ag material; c. Active layer and encapsulation layer coating: The linoline system organic active layer (1) is evenly covered on the interdigitated electrode as the contact electrode (2) and the power electrode (3) by a single variable speed coating method with an initial speed of 1000 rpm for 30 seconds, and then the surface of the linoline system organic active layer (1) is coated with a thin film encapsulation layer (5).

[0010] The flexible temperature sensor and preparation method described in the present invention fix the contact electrode and the power electrode on a flexible substrate, cover the contact electrode and the power electrode with a linolenic acid system organic active layer, and cover the linolenic acid system organic active layer with a thin film encapsulation layer. The sensor can effectively improve stability and sensitivity, and aims to address the shortcomings of existing flexible temperature sensors in terms of flexibility, stability, response speed and manufacturing process.

[0011] The flexible temperature sensor of the present invention has high sensitivity, excellent flexibility and long-term stability due to its unique structural design and material selection, and can be widely used in various smart devices, especially in wearable electronic products.

[0012] In the flexible temperature sensor of this invention, the contact and power electrodes utilize micron-channel electrodes, four-finger electrodes, or interdigitated electrodes. The electrode dimensions are precisely controlled to 20 x 5 μm, enabling high conductivity and accuracy within a compact footprint. The rylinium-based organic active layer is composed of either or both rylene and imide groups. These molecular systems possess long conjugated chains, enabling effective response to temperature changes and transmission of electrical signals.

[0013] Under the protection of the thin film encapsulation layer, the organic active layer of the lyophylline system exhibits excellent temperature sensitivity and stability, effectively extending the service life of the sensor.

[0014] The design of the thin-film encapsulation layer is another major innovation of this invention, providing effective environmental protection for the entire sensor while enhancing its mechanical flexibility and electrical stability. This encapsulation layer not only protects the lyoline-based organic active layer from environmental influences but also ensures the reliability of the temperature sensor over extended periods of use.

[0015] The fabrication method of the present invention combines oxygen plasma activation with vacuum electrode deposition to ensure good adhesion and conductivity between the contact and power electrodes and the flexible substrate. Coating with a linoline-based organic active layer and a thin-film encapsulation layer effectively protects the contact and power electrodes, as well as the linoline-based organic active layer, while also improving temperature response.

[0016] A single variable speed coating method is used to ensure that the organic active layer of the linolenic acid system is evenly covered on the surface of the flexible substrate, further improving the performance of the sensor.

[0017] The flexible temperature sensor and its manufacturing method described in the present invention have the following main features (1) Levlin organic active layer: The Levlin organic active layer can produce significant resistance changes when the temperature changes, thereby achieving highly sensitive temperature detection. At the same time, the Levlin organic active layer can operate stably within a certain temperature range and has a long service life.

[0018] (2) The organic active layer of the linoline system can also adjust the band gap width by adjusting one or more linoline molecules, thereby adjusting the temperature response performance and temperature sensitivity of the sensor. The adjustability of the band gap significantly improves the response accuracy of the sensor in a wide temperature range.

[0019] (3) Contact electrode and power electrode design and process: This invention improves the accuracy and response speed of the temperature sensor by using micron-channel electrodes (the electrode portion consists of six groups of parallel electrodes), four-finger electrodes, and interdigitated electrodes. These electrode structures can ensure the conduction effect of current at different temperatures, thereby improving the performance of the temperature sensor.

[0020] (4) Efficient Manufacturing Method: The manufacturing method of the present invention includes the following steps: oxygen plasma activation treatment, continuous vacuum electrode deposition, coating of a linotype organic active layer, and thin-film encapsulation layer. This ensures a stable sensor structure and high production efficiency. Furthermore, the linotype organic active layer is coated using a single-pass variable speed method, resulting in a uniform coating and improving the performance and stability of the sensor.

[0021] (5) Optimized temperature response characteristics: Through the precisely designed electrode structure and organic active layer, the present invention can achieve rapid response to temperature changes and has good sensitivity to changes in different temperature ranges, so that the temperature sensor can accurately capture temperature fluctuations and improve reliability in practical applications.

[0022] (6) Wide range of applications: Due to its flexible substrate and high-performance organic active layer, the flexible temperature sensor of the present invention can be applied to various deformable devices and materials, such as wearable devices, smart phones, flexible electronic products, etc., and has strong market application prospects.

[0023] In summary, the present invention has obvious innovation and superiority in the design, manufacturing process, temperature response performance and other aspects of the flexible temperature sensor. It can provide high-performance and reliable temperature detection solutions for related fields and promote the development and application of flexible electronic technology.

[0024] The lysine molecular system can precisely regulate the energy band structure and band gap size of the active layer by changing the length of its conjugated chain, electron donation / acceptance ability and intermolecular interaction force, thereby changing its electronic properties and temperature response characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the cross-sectional structure of embodiments 1, 2, and 3 of the flexible temperature sensor of the present invention; Figure 2 This is a schematic structural diagram of the contact between the electrode and the active layer of Example 1 of the flexible temperature sensor of the present invention; Figure 3 This is a schematic structural diagram of the contact mode between the electrode and the active layer of Example 2 of the flexible temperature sensor of the present invention; Figure 4 This is a schematic structural diagram of the contact between the electrode and the active layer of Example 3 of the flexible temperature sensor of the present invention; Figure 5 The device resistance variation curves obtained in Examples 1, 2, and 3 of the flexible temperature sensor of the present invention as a function of low temperature are shown; Figure 6 The figure shows the curve of device resistance changing with high temperature obtained in Examples 1, 2 and 3 of the flexible temperature sensor of the present invention.

[0026] In the accompanying drawings, the components represented by the respective reference numerals are as follows: 1. Organic active layer of linoleum system; 2. Contact electrode; 3. Power electrode; 4. Flexible substrate; 5. Organic encapsulation layer. DETAILED DESCRIPTION Example 1

[0027] The flexible temperature sensor described in the present invention is composed of a flexible substrate 4, a contact electrode 2, a power electrode 3, a thin film encapsulation layer 5 and a linoline system organic active layer 1. The contact electrode 2 and the power electrode 3 are respectively fixed on the flexible substrate 4, and the linoline system organic active layer 1 is covered on the contact electrode 2 and the power electrode 3. The thin film encapsulation layer 5 covers the linoline system organic active layer 1. The contact electrode 2 and the power electrode 3 are composed of micron channel electrodes with a channel size of 20×5μm; the contact electrode 2 and the power electrode 3 are composed of six groups of parallel electrodes, and the linoline system organic active layer 1 is composed of a linoline system organic active layer containing The organic semiconductor material having a Rylene group and / or an imide group is an organic oligomer or a high molecular polymer; the Rylene group has a rigid conjugated structure composed of a benzene ring or a naphthalene ring, and the imide group is a -C(=O)-NH- structural unit. The two can be located in the main chain or side chain, or bridged by a conjugated structure to form an electron transport / donor channel; the thin film encapsulation layer 5 is polyimide, epoxy resin, silicone rubber, polyurethane, polyester film, fluorinated polymer, polyethylene terephthalate, thermoplastic polyurethane or carbon nanotube / graphene, and the contact electrode 2 and the power electrode 3 are Ag materials; Micron channel electrode flexible temperature sensor: See also Figure 2 This is a schematic diagram of the contact structure between the electrodes and the active layer of the micron-channel electrode flexible temperature sensor. The Ag material contact electrode 2 and the Ag material power electrode 3 are composed of six groups of parallel electrodes. a. Using the flexible substrate 4 as a processing carrier, the surface of the flexible substrate 4 is first activated with oxygen plasma to improve the adhesion of the subsequent electrode material; b. Electrode Fabrication: A micron-channel Ag contact electrode 2 and an Ag power electrode 3 with a channel size of 20×5 μm are deposited on the surface of the flexible substrate 4 obtained in step a using a vacuum deposition method. A stable conductive layer is formed by continuous deposition. The micron-channel electrode provides higher precision and sensitivity for capturing and transmitting temperature signals. c. Active layer and encapsulation layer coating: The rylene system organic active layer 1 composed of rylene groups and imide groups is coated by a single variable speed coating method with an initial speed of 1000 rpm for 30 seconds. The rylene system organic active layer 1 is evenly covered on the Ag material contact electrode 2 and the Ag material power electrode 3 obtained in step b by spin coating. Then, a polyimide film encapsulation layer 5 is coated on the surface of the rylene system organic active layer 1 to protect the rylene system organic active layer 1 from the influence of the external environment.

[0028] Final processing and testing: After coating, the entire sensor is cured at room temperature for 1 hour, and its resistance changes at different temperatures are tested to evaluate its stability in different temperature ranges. Figure 4 、 5 shown. Example 2

[0029] Preparation of four-finger electrode flexible temperature sensor: See also Figure 3 This is a schematic diagram of the contact structure of the electrodes and the active layer of the four-finger electrode flexible temperature sensor. The sensor is constructed according to Example 1: a. Using the flexible substrate 4 as a processing carrier, the surface of the flexible substrate 4 is first activated with oxygen plasma to improve the adhesion of the electrode material; b. Electrode fabrication: The flexible substrate 4 obtained in step a is deposited on its surface using a vacuum deposition method to form a four-finger electrode as a contact electrode 2. The four-finger electrode is designed to have four parallel, equally spaced finger-shaped Ag material contact electrodes 2. Continuous deposition forms a stable conductive layer, which can effectively increase the electrode surface area and improve the response speed of the sensor. c. Active layer and encapsulation layer coating: The rylene system organic active layer 1 composed of rylene groups and imide groups is evenly covered on the four-finger contact electrode 2 made of Ag material using a single variable speed coating method with an initial speed of 1000 rpm for 30 seconds. The surface of the rylene system organic active layer 1 is then coated with an epoxy resin thin film encapsulation layer 5 to ensure its stability and protective effect.

[0030] Final processing and testing: After coating, the entire sensor is cured at room temperature for 1 hour, and its stability in different temperature ranges is evaluated through temperature gradient testing. Figure 4 、 5 shown. Example 3

[0031] Preparation of interdigitated electrode flexible temperature sensor: See also Figure 3 Schematic diagram of the contact structure between the electrode and the active layer of the flexible temperature sensor with interdigitated electrodes, the sensor is implemented according to Example 1: a. Using the flexible substrate 4 as a processing carrier, the surface of the flexible substrate 4 is first activated with oxygen plasma to increase the surface tension and enhance the adhesion of the electrode; b. Electrode fabrication: An intercalation structure is created on the surface of the flexible substrate 4 obtained in step a, and intercalation electrodes are continuously deposited as Ag material contact electrodes 2 and Ag material power electrodes 3 by vacuum evaporation to further improve the contact efficiency between the electrodes; c. Active layer and encapsulation layer coating: The rylene system organic active layer 1 composed of rylene groups and imide groups is evenly coated on the surface of the Ag material contact electrode 2 and the Ag material power electrode 3 by spin coating using a single variable speed coating method with an initial speed of 1000 rpm for 30 seconds to ensure good electrical conductivity and temperature sensitivity. The surface of the rylene system organic active layer 1 is then coated with a polyurethane film encapsulation layer 5 to ensure its stability and protection and prevent the external environment from affecting the sensor performance.

[0032] Final processing and testing: Curing at room temperature for 1 hour, testing the working performance of the temperature sensor, and evaluating its stability in different temperature ranges. Figure 4 、 5 shown.

Claims

1. A flexible temperature sensor, characterized in that: The sensor is composed of a flexible substrate (4), a contact electrode (2), a power electrode (3), a thin film encapsulation layer (5) and a linoline system organic active layer (1). The contact electrode (2) and the power electrode (3) are fixed on the flexible substrate (4), respectively. The linoline system organic active layer (1) is covered on the contact electrode (2) and the power electrode (3). The thin film encapsulation layer (5) is covered on the linoline system organic active layer (1). The contact electrode (2) and the power electrode (3) are composed of micron channel type electrodes, four-finger electrodes or interdigitated electrodes. The micron channel type electrode has a channel size of 20×5μm. The contact electrode (2) and the power electrode (3) are composed of six groups of parallel electrodes. The linoline system organic active layer (1) is covered on the contact electrode (2) and the power electrode (3). The organic active layer (1) of the phenoxy group system is composed of an organic semiconductor material containing a Rylene group and / or an imide group, which is an organic oligomer or a high molecular polymer; the Rylene group has a rigid conjugated structure composed of a benzene ring or a naphthalene ring, and the imide group is a -C(=O)-NH- structural unit, and the two are located in the main chain or side chain, or are bridged by a conjugated structure to form an electron transport / donor channel; the thin film encapsulation layer (5) is polyimide, epoxy resin, silicone rubber, polyurethane, polyester film, fluorinated polymer, polyethylene terephthalate, thermoplastic polyurethane or carbon nanotube / graphene, and the contact electrode (2) and the power electrode (3) are Ag materials.

2. The method for manufacturing a flexible temperature sensor according to claim 1, wherein: Follow these steps: Micron channel electrode flexible temperature sensor: a. Using the flexible substrate (4) as a processing carrier, first performing an oxygen plasma activation treatment on the surface of the flexible substrate (4); b. Electrode fabrication: A micron-channel contact electrode (2) and a power electrode (3) with a channel size of 20×5 μm are deposited on the surface of the flexible substrate (4) obtained in step a by vacuum deposition. The electrode material is Ag material, and a stable conductive layer is formed by continuous deposition; c. Active layer and encapsulation layer coating: The coated organic active layer (1) of the linoline system is coated by a single variable speed coating method with an initial speed of 1000 rpm for 30 seconds, uniformly covering the contact electrode (2) and the power electrode (3) obtained in step b, and then coating the surface of the coated organic active layer (1) of the linoline system with a thin film encapsulation layer (5).

3. The method for manufacturing a flexible temperature sensor according to claim 1, wherein: Follow these steps: Four-finger electrode flexible temperature sensor: a. Using the flexible substrate (4) as a processing carrier, first performing an oxygen plasma activation treatment on the surface of the flexible substrate (4); b. Electrode fabrication: On the surface of the flexible substrate (4), a four-finger electrode is deposited as a contact electrode (2) using a vacuum deposition method. The structure of the four-finger electrode is designed to be four parallel and equally spaced finger-shaped contact electrodes (2). The electrode material is Ag material, and a stable conductive layer is formed by continuous deposition; c. Coating of the active layer and the encapsulation layer: The coated organic active layer (1) of the linoline system is coated using a single variable speed coating method with an initial speed of 1000 rpm for 30 seconds, uniformly covering the four-finger electrode as the contact electrode (2), and then coating the surface of the coated organic active layer (1) of the linoline system with a thin film encapsulation layer (5).

4. The method for manufacturing a flexible temperature sensor according to claim 1, wherein: Follow these steps: Interdigitated electrode flexible temperature sensor: a. Using the flexible substrate (4) as a processing carrier, first performing an oxygen plasma activation treatment on the surface of the flexible substrate (4); b. Electrode fabrication: creating an intercalation structure on the surface of a flexible substrate (4), and continuously depositing intercalation electrodes as contact electrodes (2) and power electrodes (3) by vacuum evaporation, wherein the electrode material is Ag material; c. Active layer and encapsulation layer coating: The linoline system organic active layer (1) is evenly covered on the interdigitated electrode as the contact electrode (2) and the power electrode (3) by a single variable speed coating method with an initial speed of 1000 rpm for 30 seconds, and then the surface of the linoline system organic active layer (1) is coated with a thin film encapsulation layer (5).

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