CN113237568A - Flexible temperature sensor - Google Patents

Flexible temperature sensor Download PDF

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Publication number
CN113237568A
CN113237568A CN202110442943.XA CN202110442943A CN113237568A CN 113237568 A CN113237568 A CN 113237568A CN 202110442943 A CN202110442943 A CN 202110442943A CN 113237568 A CN113237568 A CN 113237568A
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CN
China
Prior art keywords
flexible
temperature
sensitive element
conductive
flexible electrode
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Pending
Application number
CN202110442943.XA
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Chinese (zh)
Inventor
黄景诚
陈国宁
邝淼
陈泽钦
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Guangzhou Carbon Technology Co ltd
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Guangzhou Carbon Technology Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by Guangzhou Carbon Technology Co ltd filed Critical Guangzhou Carbon Technology Co ltd
Priority to CN202110442943.XA priority Critical patent/CN113237568A/en
Publication of CN113237568A publication Critical patent/CN113237568A/en
Pending legal-status Critical Current

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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01KMEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K7/00Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
    • G01K7/16Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements
    • G01K7/22Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a non-linear resistance, e.g. thermistor

Abstract

The invention relates to a flexible temperature sensor, which comprises a flexible substrate, a first flexible electrode, a second flexible electrode and a conductive temperature-sensitive element, wherein the first flexible electrode, the second flexible electrode and the conductive temperature-sensitive element are arranged on the flexible substrate; the first flexible electrode is connected with a first end of the conductive temperature-sensitive element, and the second flexible electrode is connected with a second end of the conductive temperature-sensitive element; the surface of the conductive temperature-sensitive element is provided with a defect structure, so that the migration speed and the path of a carrier are changed by the defect structure when the conductive temperature-sensitive element is transported. According to the flexible temperature sensor, the material with the surface defect structure is used as the conductive temperature-sensitive element, so that the conductive temperature-sensitive element has higher temperature-sensitive characteristic, and the sensitivity and accuracy of the temperature sensor are improved.

Description

Flexible temperature sensor
Technical Field
The invention relates to the technical field of sensor equipment, in particular to a flexible temperature sensor.
Background
A temperature sensor (temperature transducer) refers to a sensor that senses temperature and converts it into a usable output signal. The temperature sensor is the core part of the temperature measuring instrument and has a plurality of varieties. The measurement method can be divided into a contact type and a non-contact type, and the measurement method can be divided into a thermal resistor and a thermocouple according to the characteristics of sensor materials and electronic elements.
The flexible temperature sensor is a temperature sensing device which keeps the original characteristics of softness, easy deformation and the like, converts a temperature signal into an electric signal through monitoring, and combines the temperature sensor with different flexible substrate materials to manufacture the temperature sensing device according to different use environments (such as different fields of medical health monitoring, sports, communication, aerospace, fire fighting and the like).
The flexible temperature sensor generally employs an NTC thermistor, which has ultra-thin and excellent electrical insulation properties and can be safely used in an environment where it may come into contact with an electrode. NTC is an abbreviation for Negative Temperature Coefficient, meaning that the resistance value of an NTC thermistor decreases with increasing Temperature. The temperature measuring, temperature compensating and temperature controlling assembly can be manufactured by utilizing the characteristic.
However, the resistance of the conventional thermistor can be obviously changed only when the conventional thermistor is changed in a large temperature range, the temperature-sensitive performance is poor, and the temperature-sensitive performance has large fluctuation in a certain temperature range.
Disclosure of Invention
Based on this, the invention aims to provide a flexible temperature sensor, which adopts a material with a surface defect structure as a conductive temperature-sensitive element, so that the conductive temperature-sensitive element has higher temperature-sensitive characteristic, and the sensitivity and accuracy of the temperature sensor are improved.
In a first aspect, the present invention provides a flexible temperature sensor, including a flexible substrate, and a first flexible electrode, a second flexible electrode and a conductive temperature-sensitive element disposed on the flexible substrate;
the first flexible electrode is connected with a first end of the conductive temperature-sensitive element, and the second flexible electrode is connected with a second end of the conductive temperature-sensitive element;
the surface of the conductive temperature-sensitive element is provided with a defect structure, so that the migration speed and the path of a carrier are changed by the defect structure when the conductive temperature-sensitive element is transported.
Further, the conductive temperature-sensitive element is made of a conductive temperature-sensitive material with a negative temperature coefficient.
Further, the conductive temperature-sensitive element is made of a carbon-based material.
Further, the carbon-based material includes at least any one of:
carbon fiber, carbon cloth, carbon paste, carbon film.
Further, the conductive temperature-sensitive element is of a square structure, a first end of the conductive temperature-sensitive element is arranged on the upper surface of the first flexible electrode, and a second end of the conductive temperature-sensitive element is arranged on the upper surface of the second flexible electrode.
The flexible touch screen further comprises a third flexible electrode and a fourth flexible electrode, wherein the third flexible electrode is connected with the first flexible electrode through a lead, and the fourth flexible electrode is connected with the second flexible electrode through a lead.
Further, the lead is made of a metal material, a conductive film or a carbon fiber material.
Further, the defect structure includes at least any one of:
point defects, line defects, surface defects, bulk defects.
Further, the number of defects on the surface of the conductive temperature-sensitive element is in positive correlation with the specific surface area of the conductive temperature-sensitive element.
Further, the flexible substrate is a flexible circuit board.
The flexible temperature sensor provided by the embodiment of the invention has the advantages that the first flexible electrode and the second flexible electrode are arranged on the flexible substrate, the conductive temperature-sensitive element is arranged between the first flexible electrodes, the surface of the conductive temperature-sensitive element is provided with the defect structure, so that current carriers can be scattered by the defect structure when being transported on the surface of the conductive temperature-sensitive element, the migration speed and the migration path of the current carriers are further changed, the resistance of the conductive temperature-sensitive element is increased, when the same external temperature change is detected, the conductive temperature-sensitive element has larger resistance change compared with the traditional NTC thermistor, and the curve of the resistance along with the temperature change is smoother, so that the flexible temperature sensor provided by the embodiment of the invention has higher temperature-sensitive characteristic, and compared with the traditional NTC thermistor, the temperature sensor can detect more subtle temperature change of a measured object, the temperature detection result is more accurate, and the sensitivity and the accuracy of the temperature sensor are greatly improved.
For a better understanding and practice, the invention is described in detail below with reference to the accompanying drawings.
Drawings
FIG. 1 is a schematic structural diagram of a flexible temperature sensor in accordance with one embodiment of the present invention;
FIG. 2 is a schematic diagram of the temperature measurement principle of a flexible temperature sensor according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of the pore size of the conductive temperature sensitive element of the flexible temperature sensor according to one embodiment of the invention;
FIG. 4 is a schematic structural diagram of a flexible temperature sensor in one embodiment of the present invention;
FIG. 5 is a schematic diagram of a flexible temperature sensor in accordance with an embodiment of the present invention;
FIG. 6 is a graph comparing temperature-sensitive performance of a conductive temperature-sensitive element according to an embodiment of the present invention with that of a conductive temperature-sensitive element according to the prior art;
reference numerals: 10-a flexible temperature sensor, 11-a flexible substrate, 12-a first flexible electrode, 13-a second flexible electrode, 14-a conductive temperature-sensitive element, 15-a third flexible electrode and 16-a fourth flexible electrode.
Detailed Description
In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.
The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the present application. As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.
When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the application, as detailed in the appended claims. In the description of the present application, it is to be understood that the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not necessarily used to describe a particular order or sequence, nor are they to be construed as indicating or implying relative importance. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.
Further, in the description of the present application, "a plurality" means two or more unless otherwise specified. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.
Referring to fig. 1, which is a schematic diagram of a basic structure of a flexible temperature sensor 10 according to an embodiment of the present invention, in fig. 1, the flexible temperature sensor 10 includes a flexible substrate 11, and a first flexible electrode 12, a second flexible electrode 13 and a conductive temperature-sensitive element 14 disposed on the flexible substrate 11. The first flexible electrode 12 is electrically connected to a first end of the conductive temperature-sensitive element 14, and the second flexible electrode 13 is electrically connected to a second end of the conductive temperature-sensitive element 14.
The conductive temperature-sensitive element 14 is an electronic component made of a conductive temperature-sensitive material of which the resistance changes along with the temperature change, and the conductive temperature-sensitive element 14 is used for directly converting the temperature change into the resistance change.
As shown in fig. 2, which is a schematic diagram of an application scenario of the flexible temperature sensor of the present invention, in an embodiment, the first flexible electrode 12 is used to be connected to an anode of a power VCC through a lead, and the second flexible electrode 13 is used to be connected to a cathode of the power VCC through a lead, so that the power VCC, the first flexible electrode 12, the conductive temperature-sensitive element 14, and the second flexible electrode 13 form a complete power supply loop, and meanwhile, a current detection element may be further disposed in the power supply loop, when the conductive temperature-sensitive element 14 detects a temperature change, and thus a resistance changes, a current in the power supply loop may also change correspondingly, and by detecting a current change in the power supply loop, temperature detection may be implemented.
In fig. 2, the power source VCC is a dc power source. In other examples, the power may be supplied in a different form such as an ac power supply.
Aiming at the technical problem that the sensitivity and accuracy of a temperature sensor are not high enough due to the fact that the temperature-sensitive characteristic of a traditional conductive temperature-sensitive element is low, in the embodiment of the application, a conductive temperature-sensitive element 14 with a defect structure on the surface is adopted, and the material surface of the conductive temperature-sensitive element 14 contains a large number of defects.
The defect structure of the conductive temperature-sensitive element 14 may be one or more of a point defect, a line defect, a surface defect, and a bulk defect.
Point defects refer to structural defects where the perturbation to the crystal only reaches a few atomic spacings in any direction. Point defects are a local disorder of the crystal lattice in the crystal, affecting only a few neighboring particles. The point defects can be classified into the following three categories according to their different causes: intrinsic defects, impurity defects, and electronic defects.
The type of intrinsic defect is the occurrence of vacancies at lattice nodes in the lattice or the excess of particles in the interstitial spaces where no particles are present (interstitial particles). Furthermore, it is also possible that the position that the particles of one type occupy in the form of another type of particle should occupy is offset. The impurity defects are the largest number of point defects. Impurity particles with smaller radii often enter the crystal as interstitial particles. The electronic defect can be regarded as an electronic effect defect caused by the above two types of defects.
In the present embodiment, the point defect is preferably in the form of a plurality of non-adjacent vacancies appearing in the atomic arrangement on the surface of the electrically conductive and temperature sensitive member 14.
Line defects are also known as dislocations. Meaning that periodic disruptions within the lattice occur on a line with the dislocated atoms located near the line. In the embodiment of the present application, the linear defect is preferably in the form of a plurality of vacancies aligned in a straight line in the atomic arrangement on the surface of the conductive temperature sensitive member 14.
The surface defects are called "stacking faults". In the embodiment of the present application, the form of the surface defect is preferably a vacancy in one plane in the atomic arrangement on the surface of the electrically conductive temperature-sensitive member 14, and the form of the bulk defect is preferably a vacancy in a three-dimensional structure in the atomic arrangement on the surface of the electrically conductive temperature-sensitive member 14.
After the above-mentioned defect structure occurs in the conductive temperature-sensitive element 14, the carriers are scattered by the defect structure when being transported on the surface of the conductive temperature-sensitive element 14, and further the speed and the path of the carrier migration are changed, so that the resistance of the conductive temperature-sensitive element 14 is changed correspondingly along with the change of the number of the defects, wherein the larger the number of the defects is, the larger the resistance of the conductive temperature-sensitive element 14 is because the thermistor of the conductive temperature-sensitive element is directly related to the carrier mobility of the material. Here, the carrier refers to an electron or a hole inside the material, and the magnitude of the transfer speed thereof is affected by temperature.
In one embodiment, the number of defects on the surface of the conductive temperature-sensitive element 14 is in positive correlation with the specific surface area of the conductive temperature-sensitive element 14, i.e. the specific surface area can be used to characterize the number of surface defects.
In an embodiment, the flexible substrate 11 may be a flexible circuit board, and the wires connected to the first flexible electrode 12 and the second flexible electrode 13 in fig. 2 may be wires disposed inside the flexible substrate 11.
In one embodiment, the temperature-sensitive and conductive element 14 is made of a temperature-sensitive and conductive material with a negative temperature coefficient, that is, the resistance of the temperature-sensitive and conductive element 14 decreases as the detected temperature increases.
In one embodiment, the conductive temperature sensitive element 14 is made of a carbon-based material, and the carbon-based material includes at least any one of the following: carbon fiber, carbon cloth, carbon paste, carbon film. The carbon-based material has the characteristics of high conductivity, low cost, excellent stability and the like.
In one embodiment, the defect structure of the conductive temperature sensitive element 14 is a plurality of micropores formed on the surface of the carbon-based material, and the size distribution of the micropores is shown in fig. 3.
In one embodiment, the first flexible electrode 12 and the second flexible electrode 13 are made of carbon fiber material, which has good flexibility and electrical conductivity.
As shown in fig. 4, in another embodiment, the conductive temperature-sensitive element 14 of the embodiment of the present application is a square structure, a first end of the conductive temperature-sensitive element 14 is disposed on the upper surface of the first flexible electrode 12, and a second end of the conductive temperature-sensitive element 14 is disposed on the upper surface of the second flexible electrode 13, so that the conductive temperature-sensitive element 14 and the first flexible electrode 12 and the second flexible electrode 13 have good contact, and the first flexible electrode 12 and the second flexible electrode 13 are connected to an external power source through a conducting wire disposed inside the flexible substrate 11 or through an external conducting wire.
In another embodiment, as shown in fig. 5, the flexible temperature sensor of the embodiment of the present application further includes a third flexible electrode 15 and a fourth flexible electrode 16, the third flexible electrode 15 is connected to the first flexible electrode 12 through a lead, and the fourth flexible electrode 16 is connected to the second flexible electrode 13 through a lead, in the example of fig. 5, both the third flexible electrode 15 and the fourth flexible electrode 16 and the lead may be made of carbon fiber materials. The third flexible electrode 15 and the fourth flexible electrode 16 are connected to an external power source through a lead wire provided inside the flexible substrate 11 or through an external lead wire. In other examples, the conductive wires may be made of a metal material, such as copper wires and gold wires, or conductive films formed by sputtering.
As shown in fig. 6, the left side of fig. 6 is a schematic diagram of a change curve of the resistance of the conductive temperature-sensitive material along with the temperature change when the common carbon-based material is used as the conductive temperature-sensitive element of the flexible temperature sensor, as can be seen from the diagram, the change amount of the resistance along with the temperature is small, and a large number of burrs are generated on the curve.
Fig. 6 is a schematic diagram of a change curve of resistance of the conductive temperature-sensitive material with temperature change when the carbon-based material with the surface having the defect structure is used as the conductive temperature-sensitive element of the flexible temperature sensor according to the embodiment of the present application, as can be seen from the diagram, the change amount of the resistance with temperature is much higher than that of the left diagram, and the curve is smoother.
The flexible temperature sensor provided by the embodiment of the invention has the advantages that the first flexible electrode and the second flexible electrode are arranged on the flexible substrate, the conductive temperature-sensitive element is arranged between the first flexible electrodes, the surface of the conductive temperature-sensitive element is provided with the defect structure, so that current carriers can be scattered by the defect structure when being transported on the surface of the conductive temperature-sensitive element, the migration speed and the migration path of the current carriers are further changed, the resistance of the conductive temperature-sensitive element is increased, when the same external temperature change is detected, the conductive temperature-sensitive element has larger resistance change compared with the traditional NTC thermistor, and the curve of the resistance along with the temperature change is smoother, so that the flexible temperature sensor provided by the embodiment of the invention has higher temperature-sensitive characteristic, and compared with the traditional NTC thermistor, the temperature sensor can detect more subtle temperature change of a measured object, the temperature detection result is more accurate, and the sensitivity and the accuracy of the temperature sensor are greatly improved.
The flexible temperature sensor provided by the embodiment of the invention is structurally flexible, so that the flexible temperature sensor can be well attached to various curved objects, and has wide application prospects in the fields of health monitoring, bionic robots and the like.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.

Claims (10)

1. A flexible temperature sensor, characterized by:
the flexible substrate comprises a flexible substrate, a first flexible electrode, a second flexible electrode and a conductive temperature-sensitive element, wherein the first flexible electrode, the second flexible electrode and the conductive temperature-sensitive element are arranged on the flexible substrate;
the first flexible electrode is connected with a first end of the conductive temperature-sensitive element, and the second flexible electrode is connected with a second end of the conductive temperature-sensitive element;
the surface of the conductive temperature-sensitive element is provided with a defect structure, so that a carrier is transferred by the defect structure to change the migration speed and the path, wherein the carrier refers to electrons or holes in the material, and the migration speed is influenced by the temperature.
2. A flexible temperature sensor according to claim 1, wherein:
the conductive temperature-sensitive element is made of a conductive temperature-sensitive material with a negative temperature coefficient.
3. A flexible temperature sensor according to claim 2, wherein:
the conductive temperature-sensitive element is made of a carbon-based material.
4. A flexible temperature sensor according to claim 3, wherein:
the carbon-based material includes at least any one of:
carbon fiber, carbon cloth, carbon paste, carbon film.
5. A flexible temperature sensor according to any one of claims 1 to 4, wherein:
the first end of the conductive temperature-sensitive element is arranged on the upper surface of the first flexible electrode, and the second end of the conductive temperature-sensitive element is arranged on the upper surface of the second flexible electrode.
6. A flexible temperature sensor according to claim 5, wherein:
the flexible electrode structure comprises a first flexible electrode, a second flexible electrode and a third flexible electrode, wherein the first flexible electrode is connected with the second flexible electrode through a lead, and the second flexible electrode is connected with the fourth flexible electrode through a lead.
7. A flexible temperature sensor according to claim 6, wherein:
the lead is made of a metal material, a conductive film or a carbon fiber material.
8. A flexible temperature sensor according to claim 1, wherein:
the defect structure includes at least any one of:
point defects, line defects, surface defects, bulk defects.
9. A flexible temperature sensor according to claim 1, wherein:
the number of the defects on the surface of the conductive temperature-sensitive element is in positive correlation with the specific surface area of the conductive temperature-sensitive element.
10. A flexible temperature sensor according to claim 1, wherein:
the flexible substrate is a flexible circuit board.
CN202110442943.XA 2021-04-23 2021-04-23 Flexible temperature sensor Pending CN113237568A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110442943.XA CN113237568A (en) 2021-04-23 2021-04-23 Flexible temperature sensor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110442943.XA CN113237568A (en) 2021-04-23 2021-04-23 Flexible temperature sensor

Publications (1)

Publication Number Publication Date
CN113237568A true CN113237568A (en) 2021-08-10

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Application Number Title Priority Date Filing Date
CN202110442943.XA Pending CN113237568A (en) 2021-04-23 2021-04-23 Flexible temperature sensor

Country Status (1)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114623947A (en) * 2022-03-24 2022-06-14 广东粤港澳大湾区协同创新研究院 Flexible temperature sensor and preparation method thereof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114623947A (en) * 2022-03-24 2022-06-14 广东粤港澳大湾区协同创新研究院 Flexible temperature sensor and preparation method thereof
CN114623947B (en) * 2022-03-24 2023-10-27 广东粤港澳大湾区协同创新研究院 Flexible temperature sensor and preparation method thereof

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