Flexible temperature sensor

Abstract

Provided is a flexible temperature sensor including a flexible temperature-sensing fabric, wherein the flexible temperature-sensing fabric includes a fabric base and at least one flexible temperature-sensing conductive fiber, the fabric base is a flat fabric woven from a plurality of insulating fibers, and the temperature-sensing conductive fiber is fixed in the fabric base by weaving. The flexible temperature sensor has the advantages of being easy to fabricate, low in cost, washable, wide in temperature monitoring range, high in sensitivity, good in stability and repeatability, and compatible with existing textile technologies.

Claims

1. A flexible temperature sensor, comprising a flexible temperature-sensing fabric, wherein the flexible temperature-sensing fabric comprises a fabric base and at least one flexible temperature-sensing conductive fiber; the fabric base is a flat fabric woven from a plurality of insulating fibers, and the temperature-sensing conductive fiber is fixed in the fabric base in a woven manner, wherein the temperature-sensing conductive fiber is a carbon fiber doped with impurity ions, the resistance of the temperature-sensing conductive fiber has a negative temperature coefficient characteristic, and the impurity ions doped in the temperature-sensing conductive fiber include one or more of sodium ions, potassium ions, calcium ions, and chloride ions.

2. The flexible temperature sensor of claim 1, wherein the temperature-sensing conductive fiber has no cross or contact parts.

3. The flexible temperature sensor of claim 1, further comprising a data acquisition element, and two ends of the temperature-sensing conductive fiber are electrically connected to the data acquisition element respectively.

4. The flexible temperature sensor of claim 3, wherein the two ends of the temperature-sensing conductive fiber each have an end terminal electrode, and the terminal electrodes are electrically connected to the data acquisition element through wires.

5. The flexible temperature sensor of claim 1, further comprising a packaging housing, and the flexible temperature-sensing fabric is packaged in the packaging housing.

6. The flexible temperature sensor of claim 5, wherein the packaging housing is made of high-molecular polymer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

(2) FIG. 1 is a structural view of a flexible temperature sensor of embodiments of the invention;

(3) FIG. 2 is a side view of the flexible temperature sensor of embodiments of the invention;

(4) FIG. 3 is a picture of a flexible temperature-sensing fabric of embodiments of the invention;

(5) FIG. 4 is a chart of a temperature response range curve of the flexible temperature sensor of embodiments of the invention;

(6) FIG. 5 is a chart of a temperature response curve of the flexible temperature sensor within the body temperature range (30° C.-45° C.) of embodiments of the invention; and

(7) FIG. 6 is a chart of a temperature response curve of the flexible temperature sensor after the temperature sensor is washed for different times and dried in embodiments of the invention.

REFERENCE SIGNS

(8) 1, temperature-sensing conductive fiber; 2, fabric base; 3, weld point of temperature-sensing conductive fiber and wire; 4, wire; 5, packaging housing; 6, data acquisition element.

DETAILED DESCRIPTION

(9) Referring to FIG. 1-FIG. 3, the flexible temperature sensor of the invention includes a flexible temperature-sensing fabric, wherein the flexible temperature-sensing fabric includes a fabric base 2 and at least one flexible temperature-sensing conductive fiber 1, the fabric base 2 is a flat fabric woven from a plurality of insulating fibers, and the temperature-sensing conductive fiber 1 is fixed by weaving in the fabric base 2.

(10) Furthermore, the temperature-sensing conductive fiber 1 is a carbon fiber doped with impurity ions, and the resistance of the temperature-sensing conductive fiber 1 is particularly characterized by a negative temperature coefficient. Specifically, the impurity ions doped in the temperature-sensing conductive fiber may be one or more of sodium ions, potassium ions, calcium ions, chloride ions, etc.

(11) The temperature-sensing conductive fiber 1 is free of crossed or contact parts, so that short circuits are avoided.

(12) Furthermore, the insulating fibers are conventional textile fibers such as polyester fibers or flax fibers.

(13) In order to realize acquisition of detection data, the flexible temperature sensor further includes a data acquisition element 6, wherein the two ends of the temperature-sensing conductive fiber 1 are electrically connected to the data acquisition element 6 respectively. The data acquisition element 6 acquires an electrical signal by a constant voltage source and a single-chip microcomputer, then the electrical signal is converted into a temperature value according to a temperature curve formula, and the temperature value is transmitted to a terminal to be directly displayed. Two terminal electrodes are arranged respectively at the two ends of the temperature-sensing conductive fiber 1, are electrically connected to the data acquisition element 6 through wires 4 respectively, and are welded to the wires 4, and weld points 3 are shown in FIG. 1 and FIG. 2.

(14) In order to protect the flexible temperature-sensing fabric, the flexible temperature sensor further includes a packaging housing 5, and the flexible temperature-sensing fabric is packaged inside the packaging housing, as shown in FIG. 1 and FIG. 2. Furthermore, the packaging housing 5 is made from a high-molecular polymer. The packaging housing 5 is transparent or semi-transparent. For the sake of a clearer display of the relation between the packaging housing 5 and other components, the contour of the packaging housing 5 is drawn with a blank full line in FIG. 1 and FIG. 2.

Embodiment 1

(15) In this embodiment, sodium ions are doped into a chemical fiber precursor, and then the chemical fiber precursor is oxidized and carbonized at a high temperature to obtain a sodium ion-doped carbon fiber used as the temperature-sensing conductive fiber 1; afterwards, terminal electrodes are made by electroplating copper at the two ends of the temperature-sensing conductive fiber 1 and then are respectively welded to silver wires 4; and finally, the temperature-sensing conductive fiber 1 welded to the wires 4 is woven with polyesters to obtain a flat flexible temperature-sensing fabric, wherein the fiber in a dark color in FIG. 3 is the temperature-sensing conductive fiber 1.

(16) Afterwards, the flexible temperature-sensing fabric is packaged with a high-molecular polymer to manufacture a packaging housing 5, so that the flexible temperature sensor is obtained; then, the flexible temperature sensor is placed on a variable-temperature stand to test a temperature response range curve of the flexible temperature sensor. As can be seen from FIG. 4 which is a chart of the temperature response range curve of the flexible temperature sensor of embodiments of the invention, the flexible temperature sensor of embodiments of the invention is of a negative temperature coefficient type, that is, the resistance of the flexible temperature sensor decreases with the increase of temperature. In addition, the flexible temperature sensor of embodiments of the invention can detect temperatures ranging from −150° C. to 150° C., and the temperature response curve of the flexible temperature sensor matches a quadratic function fitting curve, which means that the flexible temperature sensor of embodiments of the invention has a wide temperature detection range.

Embodiment 2

(17) The flexible temperature sensor is prepared through the method in Embodiment 1 and is then placed on the variable-temperature stand to detect the temperature response of the sensor within the body temperature variation range, wherein the detection range is 30° C.-45° C., and the temperature interval is 1° C., and an obtained temperature response curve is shown in FIG. 5. As can be seen from FIG. 5, the flexible temperature sensor of embodiments of the invention has good sensitivity, the resistance variation of the sensor is in a good linear relation with the temperature variation within 30° C.-45° C., and thus, the flexible temperature sensor can monitor the body temperature in real time.

Embodiment 3

(18) The flexible temperature sensor is prepared through the method in Embodiment 1, is then placed in water to be ultrasonically cleaned for different times after the packaging housing 5 is removed, and then is dried to test the temperature response performance of the sensor at the temperature of 30° C. and the temperature of 70° C. As shown in FIG. 6, the test result indicates that the repeatability of the temperature response of the sensor is good after the sensor is ultrasonically cleaned for as long as 60 minutes, which fully proves that the flexible temperature sensor of embodiments of the invention is washable and is stable in temperature response.

(19) Although the invention has been illustrated and described in greater detail with reference to the preferred exemplary embodiment, the invention is not limited to the examples disclosed, and further variations can be inferred by a person skilled in the art, without departing from the scope of protection of the invention.

(20) For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.