JP2020176981A - Temperature sensor - Google Patents

Abstract

To provide a highly convenient temperature sensor.SOLUTION: A temperature sensor 1 according to an embodiment of the present invention includes: a flexible substrate; and a plurality of sensing units arranged on the flexible substrate. Each of the sensing units includes a thermoelectric conversion material, and detects a temperature in each sensing unit by using a voltage difference caused by a temperature gradient in the sensing units.SELECTED DRAWING: Figure 1

Description

The present invention relates to a temperature sensor, and more particularly to a temperature sensor using a thermoelectric conversion material.

The thermoelectric conversion material is a material that converts heat into electric power by utilizing the phenomenon that an electromotive force is generated when a temperature difference is generated at both ends of a p-type semiconductor or an n-type semiconductor, that is, the Seebeck effect. In recent years, such thermoelectric conversion materials have been used in various fields.

Patent Document 1 discloses a technique relating to a thermoelectric power generation device that generates thermoelectric power using exhaust gas discharged from an internal combustion engine. Patent Document 2 discloses a technique relating to a space power generation system using a thermoelectric conversion material. Patent Document 3 discloses a technique relating to a thermoelectric conversion material having a plurality of conductive materials and core-shell particles having a conductive core portion and an insulating shell portion.

Japanese Unexamined Patent Publication No. 2013-150420 Special Table 2006-507974 Japanese Unexamined Patent Publication No. 2014-241355

As described above, the thermoelectric conversion material is widely used as a power generation module because it is a material that converts heat into electric power. On the other hand, since an electromotive force is generated by a temperature difference in the thermoelectric conversion material, the thermoelectric conversion material can also be used as a temperature sensor by detecting this electromotive force.

When the thermoelectric conversion material is used as the temperature sensor, the temperature sensor can be configured by forming a sensing unit containing the thermoelectric conversion material on the substrate. Then, the temperature of the object to be measured can be measured by bringing the temperature sensor into contact with the object to be measured and detecting the electromotive force generated in the sensing unit. However, if the substrate on which the sensing part is formed is hard, the place where the temperature sensor is attached is limited, and the temperature sensor cannot be properly contacted with the object to be measured, so that the temperature can be measured accurately. There is a problem that it is not convenient, such as not being able to do it.

In view of the above problems, an object of the present invention is to provide a highly convenient temperature sensor.

The temperature sensor according to one aspect of the present invention includes a flexible substrate and a plurality of sensing units arranged on the flexible substrate, and each of the plurality of sensing units includes a thermoelectric conversion material in the sensing unit. The temperature in each of the sensing units is detected by using the voltage difference caused by the temperature gradient.

According to the present invention, it is possible to provide a highly convenient temperature sensor.

It is sectional drawing for demonstrating the temperature sensor which concerns on Embodiment 1. FIG. It is a top view for demonstrating the temperature sensor which concerns on Embodiment 1. FIG. It is a top view for demonstrating the temperature sensor which concerns on Embodiment 1. FIG. It is sectional drawing for demonstrating the temperature sensor which concerns on Embodiment 1. FIG. It is sectional drawing for demonstrating the structural example of the sensing part. It is sectional drawing for demonstrating the structural example of the sensing part. It is the top view and sectional drawing for demonstrating the structural example of the sensing part. It is sectional drawing for demonstrating the structural example of the sensing part. It is sectional drawing for demonstrating the temperature sensor which concerns on Embodiment 1. FIG. It is sectional drawing for demonstrating the temperature sensor which concerns on Embodiment 2. It is a top view for demonstrating the temperature sensor which concerns on Embodiment 2. FIG. It is sectional drawing for demonstrating the temperature sensor which concerns on Embodiment 2. It is a top view for demonstrating the temperature sensor which concerns on Embodiment 2. FIG.

Hereinafter, embodiments of the present invention will be described.
The temperature sensor according to the present embodiment includes a flexible substrate and a plurality of sensing units arranged on the flexible substrate. Each of the plurality of sensing units contains a thermoelectric conversion material, and the temperature in each sensing unit is detected by using the voltage difference caused by the temperature gradient in the sensing unit.

Since the temperature sensor according to the present embodiment uses a flexible substrate as the substrate, the temperature sensor can be made flexible. Therefore, for example, even when the object to be measured has a curved surface shape, the temperature sensor can be appropriately brought into contact with the object to be measured, and the temperature of the object to be measured can be accurately measured. Therefore, according to the invention according to the present embodiment, it is possible to provide a highly convenient temperature sensor. Further, since the temperature sensor according to the present embodiment includes a plurality of sensing units, it is possible to measure the temperature distribution in the plane of the temperature sensor.

Hereinafter, the present invention will be described in detail with reference to Embodiment 1 and Embodiment 2.
In the first embodiment, a configuration in which the temperature is detected by using the voltage difference (electromotive force) generated due to the temperature gradient in the thickness direction of the flexible substrate will be described.
In the second embodiment, a configuration in which the temperature is detected by using the voltage difference (electromotive force) generated due to the temperature gradient in the in-plane direction of the flexible substrate will be described.

<Embodiment 1>
FIG. 1 is a cross-sectional view for explaining the temperature sensor according to the first embodiment.
As shown in FIG. 1, the temperature sensor 1 includes flexible substrates 11 and 12, sensing units 13, and electrodes 14 and 15.

The flexible substrates 11 and 12 are flexible substrates and can be bent when a predetermined stress is applied. The flexible substrate 11 and the flexible substrate 12 are arranged so as to face each other. A sensing unit 13 is arranged between the flexible substrate 11 and the flexible substrate 12.

The flexible substrates 11 and 12 are film or sheet-like substrates, for example, resins such as polyimide, polyamide, polyamideimide, polyetherimide, polybenzoxazole, polyethylene terephthalate, polyethylene naphthalate, polypropylene, and polyphenylene sulfide, and rubber-like ones. It can be constructed by using an elastomer or the like. In the present embodiment, the flexible substrates 11 and 12 may be made of materials other than these as long as they have flexibility and insulating properties. The flexible substrates 11 and 12 may be configured by using the same substrate, or may be configured by combining different substrates. The thickness of the flexible substrates 11 and 12 can be, for example, about 5 to 1000 μm, but is not limited to this thickness.

The flexible substrates 11 and 12 may be decorative films that have been printed, transferred, painted, plated, engraved, or the like. Further, the flexible substrates 11 and 12 may be capable of forming a three-dimensional (3D) three-dimensional shape.

Each sensing unit 13 is arranged between the flexible substrate 11 and the flexible substrate 12, and is connected to the electrode 14 on the flexible substrate 11 side and connected to the electrode 15 on the flexible substrate 12 side. Highly conductive materials such as gold, silver, copper, and platinum can be used for the electrodes 14 and 15. The materials used for the electrodes 14 and 15 are not limited to these, and any material other than these may be used as long as it is a material having high conductivity.

As shown in FIG. 1, each of the plurality of sensing units 13 determines the voltage difference between the electrodes 14 and 15 caused by the temperature gradient (temperature difference) in the thickness direction of the flexible substrates 11 and 12. Can be used to detect temperature.

For example, when the flexible substrate 12 side is used as a reference, the flexible substrate 12 side is the low temperature side and the flexible substrate 11 side is the high temperature side, and the relative temperature of the flexible substrate 11 side with respect to the flexible substrate 12 side can be detected. That is, the temperature difference between the flexible substrate 12 side (reference side) and the flexible substrate 11 side (measurement side) can be detected. In this case, it is preferable that the temperature on the flexible substrate 12 side (reference side) is constant. When the temperature on the flexible substrate 12 side can be specified, the absolute temperature on the flexible substrate 11 side can be obtained by detecting the temperature difference on the flexible substrate 11 side with respect to the flexible substrate 12 side. The same applies to the case where the flexible substrate 11 side is used as a reference.

In the temperature sensor according to the present embodiment, in order to increase the sensitivity of the temperature sensor, a means for cooling the flexible substrate (11 or 12) on the reference side (low temperature side) may be provided. For example, as a means for cooling the flexible substrate side (low temperature side), heat dissipation means such as a heat sink, fins, graphite sheet, heat dissipation sheet, heat spreader, a water cooling system, or the like can be used. The cooling means is not limited to these, and any other cooling means may be used.

Further, in the temperature sensor according to the present embodiment, in order to increase the sensitivity of the temperature sensor, a means for transferring heat may be provided on the measurement side (flexible substrate on the high temperature side). For example, a heat conductive sheet or the like can be used as a means for transferring heat.

In the present embodiment, the sensing unit 13 is mainly configured by using a thermoelectric conversion material. As described above, the thermoelectric conversion material is a material that converts heat into electric power by utilizing the Seebeck effect. The performance of thermoelectric conversion materials is evaluated using the dimensionless thermoelectric figure of merit (ZT). The dimensionless thermoelectric figure of merit (ZT) can be obtained using the following equation (1).

^{ZT = (S 2 · σ ·} T) / κ ··· (1)

Here, S is the Seebeck coefficient (V / K), σ is the conductivity (Sm), T is the absolute temperature (K), and κ is the thermal conductivity (W / (mK)). Further, the voltage that can be taken out from the thermoelectric conversion material can be calculated by using the following formula (2).

V (V) = S (V / K) x ΔT (K) ... (2)

As shown in the formula (2), the voltage that can be extracted from the thermoelectric conversion material increases as the temperature difference ΔT generated at both ends of the thermoelectric conversion material increases if the same thermoelectric conversion material is used.

In the present embodiment, the thermoelectric conversion material is not particularly limited as long as it exhibits the Seebeck effect and can be used as the thermoelectric conversion material. As an example, the thermoelectric conversion material includes tellurium compounds such as Bi-Te compounds, Pb-Te compounds and Sb-Te compounds, Co-Sb compounds, Fe-Sb compounds, Zn-Sb compounds, scutterdite compounds and the like. Antimon compounds, Fe-Si compounds, Ge-Si compounds, Mn-Si compounds, Mg-Si compounds and other silicon compounds, hexaborates and other boron compounds, crustrate compounds and other gallium compounds, Whistler compounds, Aluminum-based compounds such as Al-claslate compounds, tin-based / rare earth-based compounds such as half-Whisler metal-to-metal compounds, metal oxide-based compounds such as Co oxide, Ti oxide, V oxide, and Zn oxide, carbon materials, and organic Organic conductive materials such as low molecular weight materials, organic conductive polymers, and polymer composite materials can be used.

In the present embodiment, considering that the temperature sensor has flexibility and that the thermoelectric conversion material can be formed by printing or coating at the time of manufacturing, a conductive organic material (organic conductive material) is used. It is preferable to construct a thermoelectric conversion material.

Examples of the organic conductive material include a polymer having thiophene and its derivative as a skeleton, a polymer having phenylene vinylene and its derivative as a skeleton, a polymer having aniline and its derivative as a skeleton, and an oligomer having pyrrole and its derivative as a skeleton. Polymers, oligomers and polymers with acetylene and its derivatives in the skeleton, polymers with heptadiene and its derivatives in the skeleton, phthalocyanines and their derivatives, diamines, phenyldiamines and their derivatives, pentacene and its derivatives, porphyrin and its derivatives Low molecular weight materials such as derivatives, cyanine, quinone and naphthoquinone can be used. In particular, polythiophene and its derivatives are particularly preferable in consideration of the manufacturing process, stability in the atmosphere, charge mobility, and the like.

As the carbon material, for example, graphite, carbon nanotubes, carbon black, graphene nanoplates, graphene and the like can be used. Considering both the Seebeck coefficient and the conductivity, at least one selected from the group consisting of carbon nanotubes, carbon black, graphene nanoplates and graphene is preferable, more preferably carbon nanotubes, and particularly preferably single-walled carbon nanotubes. Is. If necessary, these carbon materials can be modified by introducing a substituent, or can be used in coexistence with a compound capable of promoting charge transfer.

The thermoelectric conversion material may be used alone or in combination of a plurality of thermoelectric conversion materials.

2 and 3 are top views for explaining the temperature sensor according to the present embodiment. In the temperature sensor according to the present embodiment, for example, as shown in FIG. 2, a plurality of sensing units 13 may be arranged in the row direction and the column direction. In other words, the plurality of sensing units 13 may be arranged in a matrix. By arranging the plurality of sensing units 13 in this way, the temperature distribution in the plane of the temperature sensor 1 (flexible substrate 11) can be measured.

Further, in the temperature sensor according to the present embodiment, as shown in FIG. 3, for example, a plurality of sensing units 13 may be arranged in a strip shape. By arranging the plurality of sensing units 13 in this way, the temperature distribution in the plane of the temperature sensor 1 (flexible substrate 11) (the temperature distribution in the direction perpendicular to the strip-shaped sensing unit 13, that is, the temperature distribution in the left-right direction of the paper surface). ) Can be measured.

The configurations of FIGS. 2 and 3 are examples, and the arrangement of the plurality of sensing units 13 on the plane (that is, the arrangement of the main surface of the temperature sensor 1 in the plane) may be other than this.

As described above, since the temperature sensor according to the present embodiment uses the flexible substrates 11 and 12 as the substrate, the temperature sensor can be made flexible. Therefore, for example, even when the object to be measured has a curved surface shape, the temperature sensor can be appropriately brought into contact with the object to be measured, and the temperature of the object to be measured can be accurately measured. Therefore, according to the invention according to the present embodiment, it is possible to provide a highly convenient temperature sensor.

The thickness of the temperature sensor 1 according to the present embodiment is preferably 5 μm or more and 20 mm or less. By setting the thickness of the temperature sensor 1 to 20 mm or less, the thickness of the temperature sensor 1 can be reduced, and the temperature sensor can be appropriately brought into contact with the object to be measured. The value of the thickness of the temperature sensor is an example, and the thickness of the temperature sensor 1 according to the present embodiment can be appropriately changed according to the environment in which the temperature sensor is used and the like.

Next, a modified example of the temperature sensor according to the present embodiment will be described.
FIG. 4 is a cross-sectional view for explaining the temperature sensor according to the present embodiment. In the temperature sensor 2 shown in FIG. 4, the sensing unit 13 includes a thermoelectric conversion material 17 and a low heat conduction region 18. Other configurations are the same as those of the temperature sensor 1 shown in FIG.

As shown in FIG. 4, the sensing unit 13 partially has a low thermal conductivity region 18 having a thermal conductivity lower than that of the thermoelectric conversion material 17. The low thermal conductivity region 18 is configured to reduce heat conduction from the flexible substrate 11 side to the flexible substrate 12 side in the sensing unit 13. In the configuration example shown in FIG. 4, the thermoelectric conversion material 17 of the sensing unit 13 has a U-shaped cross section when cut in a plane parallel to the thickness direction. The upper surface of the U-shaped cross section of the thermoelectric conversion material 17 is connected to the electrode 14, and the lower surface of the U-shaped cross section of the thermoelectric conversion material 17 is connected to the electrode 15. A low thermal conductivity region 18 is formed between the upper surface and the lower surface of the U-shaped cross section of the thermoelectric conversion material 17.

As described above, in the temperature sensor according to the present embodiment, a voltage difference is generated due to a temperature difference between the upper part and the lower part of the sensing unit 13 (thermoelectric conversion material), and the generated voltage difference (temperature). (Signal indicating) is being detected. At this time, since the heat of the upper part (flexible substrate 11 side) of the sensing unit 13 is conducted from the upper part to the lower part of the sensing unit 13, the temperature difference between the upper part and the lower part of the sensing unit 13 gradually becomes smaller. As a result, the voltage difference (signal indicating the temperature) generated in the sensing unit 13 gradually becomes smaller. Then, when the temperature becomes uniform in the entire sensing unit 13, the temperature difference between the upper part and the lower part of the sensing unit 13 disappears, so that the voltage difference (signal indicating the temperature) of the sensing unit 13 is not detected. That is, in the temperature sensor according to the present embodiment, it is important to reduce the heat transferred from the upper part to the lower part of the sensing unit 13 (make it difficult for the heat to be transferred).

Here, the thermal resistance R (m ² · K / W) is an index of the ease of heat transfer. The higher the thermal resistance, the more difficult it is to transfer heat, and the lower the thermal resistance, the easier it is to transfer heat. The thermal resistance R is calculated by the following formula using the values of the thermal conductivity λ (W / (m · K)) of the thermoelectric conversion material and the distance d (m) (thickness in FIGS. 1 and 4) through which heat is transferred. It can be represented by (3).

R = d / λ ・ ・ ・ (3)

Further, when there are regions having different thermal conductivity with respect to the direction of heat transfer, the thermal resistance for each region is obtained as shown in the following equation (4), and the sum of the added thermal resistances is the total heat. It becomes the resistance _RT .

_RT = Σ (dn / λn) ・ ・ ・ (4)

Here, n represents the number of regions having different heat conduction and is an integer of 1 or more. Further, dn is the distance (thickness) of the nth region, and λn is the thermal conductivity of the nth region.

As shown in the equation (4), the presence of a region having a low thermal conductivity (low thermal conductivity region 18) inside the sensing unit 13 increases the thermal resistance of the sensing unit 13 in the thickness direction. Therefore, the temperature difference between the upper part and the lower part of the sensing unit 13 can be maintained, and high-sensitivity temperature detection with a good S / N ratio can be performed. Similarly, by providing the low thermal conduction region 18 inside the sensing unit 13, even if the thickness of the sensing unit 13 is reduced, a high thermal resistance is maintained between the upper part and the lower part of the sensing unit 13. Can be done. Therefore, it is possible to reduce the thickness and size of the sensing unit 13.

As the material constituting the low thermal conductivity region 18, any material may be used as long as it has a lower thermal conductivity than the thermoelectric conversion material 17, but the difference in thermal conductivity from the thermoelectric conversion material 17 is particularly large. Is more preferable. Further, the shape of the material constituting the low thermal conductivity region 18 is not particularly limited, and for example, a material such as resin, gel, paper, wood, fiber, cloth, foam, ceramic, metal, compound, etc. that can maintain the shape by itself can be used. You may use it. Further, as long as a territorial interface can be formed, a material having no specific shape such as a gas such as air or gas, a liquid such as water, a solvent, a liquid compound, or a liquid resin compound may be used. These constituents may be used alone or in combination of two or more. Considering the low thermal conductivity and handling, it is preferable to use resin, paper, foam, fiber, air or the like as the material constituting the low thermal conductivity region 18. Among these, it is particularly preferable to use foam, fiber, or paper.

The arrangement of the thermoelectric conversion material 17 and the low thermal conductivity region 18 can be freely designed according to the device design as long as the arrangement is such that the thermal conductivity of the entire sensing unit 13 is lowered.

5 (a) to 5 (i) are cross-sectional views showing an arrangement example of the thermoelectric conversion material 17 and the low heat conduction region 18 in the sensing unit 13. FIG. 5A shows a configuration example in which the low heat conduction region 18 is arranged in a part of the central portion of the sensing portion 13. 5 (b), (c), and (g) show a configuration example in which the low heat conduction region 18 is arranged in a part of the upper part of the sensing unit 13. 5 (d) and 5 (f) show a configuration example in which the low heat conduction region 18 is arranged in a part from the upper part to the lower part of the sensing unit 13. FIG. 5 (e) shows a configuration example in which the low heat conduction region 18 is arranged in a part of the upper part and a part of the central part of the sensing unit 13. FIG. 5H shows a configuration example in which a circular (spherical) low heat conduction region 18 is arranged inside the sensing unit 13. FIG. 5 (i) shows a configuration example in which the low heat conduction region 18 is randomly arranged inside the sensing unit 13.

By providing the low heat conduction region 18 in the sensing unit 13 as shown in the configurations shown in FIGS. 5 (a) to 5 (i), the heat conduction from the upper part to the lower part of the sensing unit 13 can be reduced. The configurations shown in FIGS. 5 (a) to 5 (i) are examples, and in the present embodiment, the configuration of the sensing unit 13 may be other than these.

The sensitivity of the temperature sensor is such that the contact area between the sensing unit 13 and the object to be measured (the actual contact is between the flexible substrate and the object to be measured) is large, and the temperature difference in the thickness direction of the sensing unit 13 is maintained. The more you drip, the better. Therefore, as shown in FIGS. 4, 5 (a) and 5 (h), the entire upper surface of the sensing unit 13 and the entire lower surface of the sensing unit 13 are each composed of the thermoelectric conversion material 17. Is preferable.

Further, in the present embodiment, the thermoelectric conversion material 17 may be composed of a flexible fiber base material and a conductive material impregnated in the fiber base material. Further, the low thermal conductivity region 18 may be formed by using a heat insulating material. In this case, as shown in FIG. 6, the sensing unit 13 can be configured by bending the thermoelectric conversion material 17 and sandwiching the heat insulating material (low thermal conductivity region 18) inside.

That is, when the thermoelectric conversion material 17 is formed by impregnating the fiber base material with a conductive material, the thermoelectric conversion material 17 can be made flexible. In this case, as shown in FIG. 6, the sensing portion 13 can be formed by sandwiching the heat insulating material (low thermal conduction region 18) with the flexible thermoelectric conversion material 17. Therefore, the sensing unit 13 having the low thermal conductivity region 18 can be easily formed.

Further, in the present embodiment, as shown in FIG. 7, a plurality of thermoelectric conversion materials 22 are formed in a strip shape on the flexible base material 21. Then, as shown in FIG. 8, one end of the strip-shaped thermoelectric conversion material 22 in the longitudinal direction is on the flexible substrate 11 side (upper side) (see FIG. 4), and the other end is on the flexible substrate 12 side (lower side). The sensing portion 13 may be formed by bending the base material 21 on which the thermoelectric conversion material 22 is formed so as to be such that the heat insulating material (low heat conduction region 23) is sandwiched inside. As the material constituting the base material 21, the same material as the material constituting the flexible substrates 11 and 12 listed above can be used.

Further, in the present embodiment, the sensing unit 13 may be configured by impregnating the foam with the thermoelectric conversion material 17. In this case, the foam corresponds to the low thermal conductivity region 18 shown in FIG.

The sensing unit 13 (see FIGS. 6 and 8) formed as described above is subsequently provided with an electrode 14 and a flexible substrate 11 on the upper side, and an electrode 15 and a flexible substrate 12 on the lower side. The temperature sensor 2 as shown can be formed.

Further, as shown in FIG. 9, in the present embodiment, the sensing unit may be configured by using a p-type semiconductor and an n-type semiconductor. Specifically, as shown in FIG. 9, an electrode 33 and an electrode 34 are provided on a flexible substrate 12 below the temperature sensor 3, and a p-type semiconductor 31 and an n-type semiconductor 32 are arranged on the electrodes 33 and 34, respectively. Further, an electrode 35 is provided on the flexible substrate 11 on the upper side of the temperature sensor 3, and the upper end of the p-type semiconductor 31 and the upper end of the n-type semiconductor 32 are electrically connected by using the electrode 35.

Also in the temperature sensor 3 shown in FIG. 9, a voltage difference (electromotive force) is generated between the electrodes 33 and 34 due to the temperature difference between the p-type semiconductor 31 and the n-type semiconductor 32 in the thickness direction. Therefore, by measuring this voltage difference, the temperature on the flexible substrate 11 side can be detected. As shown in FIG. 9, when the p-type semiconductor 31 and the n-type semiconductor 32 are used as the thermoelectric conversion materials, a larger potential difference can be obtained than when a single thermoelectric conversion material is used. Therefore, the sensitivity of the temperature sensor can be improved.

For example, the above-mentioned thermoelectric conversion material can be used as the material of the p-type semiconductor 31 and the n-type semiconductor 32. Further, a p-type or n-type semiconductor can be obtained by appropriately adding a dopant to the above-mentioned material.

Next, a method of manufacturing the temperature sensor (see FIG. 1) according to the present embodiment will be described.
When manufacturing the temperature sensor 1, first, the patterns of the electrodes 14 and 15 are formed on the flexible substrates 11 and 12. For example, the electrodes 14 and 15 can be formed by using a vapor deposition method such as a sputtering method. Further, a conductive paste (silver paste or the like) obtained by forming a metal powder into a paste may be printed on the flexible substrates 11 and 12 by a printing method (screen printing or the like) to form a pattern of the electrodes 14 and 15. ..

Next, the sensing unit 13 is formed. The sensing unit 13 may be formed by cutting and polishing a bulk thermoelectric conversion material. In this case, the formed sensing portion 13 is arranged on the lower electrode 15.

Further, the sensing unit 13 may be formed by printing a thermoelectric conversion material on the flexible substrate 12 (electrode 15). Specifically, the sensing unit 13 may be formed on the electrode 15 by printing a liquid containing particles of the thermoelectric conversion material on the electrode 15 formed on the flexible substrate 12. In this case, if necessary, a solvent, a binder, an additive, or the like may be added to the liquid containing the particles of the thermoelectric conversion material. When the thermoelectric conversion material is formed by printing, a conductive organic material may be used as the thermoelectric conversion material.

After that, the flexible substrate 11 is arranged on the sensing unit 13. Specifically, the flexible substrate 11 is positioned so that the upper electrode 14 comes into contact with the sensing portion 13, and the flexible substrate 11 and the flexible substrate 12 are bonded together. As a result, the temperature sensor 1 can be formed.

Further, when forming the sensing unit 13 (see FIGS. 4 to 8) having the low heat conduction region 18, the following method can be used. For example, the sensing portion 13 may be formed by winding the thermoelectric conversion material 17 in the form of a sheet around the low thermal conductive region 18 made of a low thermal conductive material such as wood or paper (see FIG. 6). Further, a material having a lower thermal conductivity than that of the thermoelectric conversion material is dispersed in a liquid containing particles of the thermoelectric conversion material, and then this dispersion is applied onto a flexible substrate and cured to form a sensing unit 13. It may be formed. In this case, the low thermal conductivity region 18 can be formed inside the thermoelectric conversion material 17 (see FIG. 5 (h)). Further, the sensing unit 13 may be formed by impregnating the foam (fiber or sponge-like molded product) with a liquid thermoelectric conversion material. In this case, the foam corresponds to the low thermal conductivity region.

The above-mentioned manufacturing method of the temperature sensor is an example, and in the present embodiment, the temperature sensor may be manufactured by using another manufacturing method.

Since the temperature sensor 1 according to the present embodiment includes a plurality of sensing units 13 (see FIGS. 2 and 3), the in-plane temperature of the temperature sensor 1 (flexible substrate 11) can be measured at the same time. Therefore, the in-plane temperature distribution of the temperature sensor 1 can be measured. Further, since the temperature sensor 1 according to the present embodiment has flexibility, even if the surface shape of the object to be measured is a curved surface shape, the surface of the temperature sensor 1 can be appropriately brought into contact with the curved surface shape. Therefore, even if the surface shape of the object to be measured is a curved surface, the temperature distribution on the surface of the object to be measured can be measured.

As described above, since the temperature sensor 1 according to the present embodiment has flexibility, it is possible to measure the temperature of various measurement objects. As an example, it can be used for measuring body temperature distribution, detecting local heat generation in electronic devices such as circuits, and the like.

In the temperature sensor 1 according to the present embodiment, the voltage differences (signals) detected by the plurality of sensing units 13 may be individually displayed on the display, or the temperature distribution may be visually displayed like a thermograph. You may try to do it.

Further, as described above, the temperature information obtained by the temperature sensor 1 according to the present embodiment is the relative temperature (that is, the temperature on the flexible substrate 11 side with respect to the temperature on the flexible substrate 12 side). Therefore, when temperature detection is performed using the temperature sensor 1 according to the present embodiment, predetermined processing is performed on the voltage difference data detected by the plurality of sensing units 13 as necessary. The data may be normalized to provide temperature distribution information. Further, by separately measuring the reference temperature and combining it with the normalized temperature distribution information, the calibration curve, or the like, the information may be the absolute temperature instead of the relative temperature. For example, the absolute temperature of the flexible substrate 11 side is obtained by setting the temperature of the flexible substrate 12 side to be a reference temperature (constant) and detecting the temperature difference of the flexible substrate 11 side with respect to the flexible substrate 12 side. be able to.

<Embodiment 2>
Next, Embodiment 2 of the present invention will be described.
10 and 11 are a cross-sectional view and a top view for explaining the temperature sensor according to the second embodiment, respectively. As shown in FIGS. 10 and 11, the temperature sensor 4 according to the present embodiment includes a flexible substrate 41, a sensing unit 43, and electrodes 44 and 45. In the present embodiment, a configuration for detecting the temperature by using the voltage difference (electromotive force) generated due to the temperature gradient in the in-plane direction of the flexible substrate 41 will be described. Since the other configurations are the same as those of the temperature sensor described in the first embodiment, duplicated description will be omitted as appropriate.

As shown in FIGS. 10 and 11, in the temperature sensor 4 according to the present embodiment, the sensing portion 43 is formed on the flexible substrate 41. Each of the plurality of sensing units 43 is arranged so as to extend in the in-plane direction of the flexible substrate 41, and is connected to the electrode 44 on one side in the longitudinal direction of the sensing unit 43 in the longitudinal direction of the sensing unit 43. It is connected to the electrode 45 on the other side. The temperature sensor 4 according to the present embodiment detects the temperature by using the voltage difference between the electrode 44 and the electrode 45 caused by the temperature gradient in the in-plane direction of the flexible substrate 41.

For example, when the electrode 45 side (right side of the paper surface) is used as a reference, the electrode 45 side is the low temperature side and the electrode 44 side is the high temperature side, and the relative temperature of the electrode 44 side with respect to the electrode 45 side can be detected. That is, the temperature difference on the electrode 44 side with respect to the electrode 45 side can be detected. In this case, it is preferable that the temperature on the electrode 45 side (reference side) is constant. When the temperature on the electrode 45 side can be specified, the absolute temperature on the electrode 44 side can be obtained by detecting the temperature difference on the electrode 44 side with respect to the electrode 45 side. The same applies to the case where the electrode 44 side (left side of the paper surface) is used as a reference.

The temperature sensor according to the present embodiment may be provided with means for cooling the electrode 45 on the reference side (low temperature side) in order to increase the sensitivity of the temperature sensor. For example, as a means for cooling the electrode 45 side (low temperature side), heat dissipation means such as a heat sink, fins, graphite sheet, heat dissipation sheet, heat spreader, a water cooling system, or the like can be used. The cooling means is not limited to these, and any other cooling means may be used.

Further, in the temperature sensor according to the present embodiment, in order to increase the sensitivity of the temperature sensor, a means for transferring heat may be provided on the measurement side (flexible substrate on the high temperature side). For example, a heat conductive sheet or the like can be used as a means for transferring heat.

In the present embodiment, the materials constituting the flexible substrate 41, the sensing unit 43, and the electrodes 44, 45 are the flexible substrates 11, 12, the sensing unit 13, and the electrodes 14, 15 provided by the temperature sensor described in the first embodiment. A material similar to the material constituting the above can be used.

Further, in the temperature sensor according to the present embodiment, similarly to the temperature sensor according to the first embodiment, even if the sensing unit 13 partially includes a low thermal conductivity region having a lower thermal conductivity than the thermoelectric conversion material. Good.

That is, as in the temperature sensor 5 shown in FIGS. 12 and 13, the sensing unit 13 may be configured by using the thermoelectric conversion material 47 and the low heat conduction region 48. More specifically, as shown in FIGS. 12 and 13, the sensing unit 43 partially has a low thermal conductivity region 48 having a thermal conductivity lower than that of the thermoelectric conversion material 47. The low thermal conductivity region 48 is configured to reduce heat conduction from the electrode 44 side to the electrode 45 side in the sensing unit 43 (when the electrode 45 side is the low temperature side).

In the configuration examples shown in FIGS. 12 and 13, the thermoelectric conversion material 47 of the sensing unit 43 extends in the in-plane direction of the flexible substrate 41, and the low heat conduction region 48 is provided in the upper portion near the central portion of the thermoelectric conversion material 47. ing. The place where the low heat conduction region 48 is arranged is not limited to the place shown in FIGS. 12 and 13, and may be provided in any place between the electrode 44 and the electrode 45 of the sensing unit 43. Good. In other words, it can be arranged at any position as long as the heat conduction from the electrode 44 side to the electrode 45 side in the sensing unit 43 can be reduced. Since the materials constituting the low thermal conductivity region 48 are the same as those described in the first embodiment, duplicated description will be omitted.

Further, in the present embodiment, a material having a thermal conductivity lower than that of the thermoelectric conversion material is dispersed in a liquid containing particles of the thermoelectric conversion material, and then this dispersion is applied onto the flexible substrate 41 and cured. As a result, the sensing unit 43 may be formed. In this case, the low thermal conductivity region 48 can be formed inside the thermoelectric conversion material 47 (see FIG. 5 (h)). Further, the sensing unit 43 may be formed by impregnating the foam (fiber or sponge-like molded product) with a liquid thermoelectric conversion material. In this case, the foam corresponds to the low thermal conductivity region.

Since the flexible substrate 41 is also used as the substrate in the temperature sensors 4 and 5 according to the present embodiment, the temperature sensor can be made flexible. Therefore, for example, even when the object to be measured has a curved surface shape, the temperature sensor can be appropriately brought into contact with the object to be measured, and the temperature of the object to be measured can be accurately measured. Therefore, according to the invention according to the present embodiment, it is possible to provide a highly convenient temperature sensor.

In the configuration example shown in FIGS. 10 to 13, the sensing unit 43 and the electrodes 44 and 45 are exposed, but the temperature sensor according to the present embodiment includes the sensing unit 43 and the electrodes 44. A cover may be further provided so as to cover the upper surface of the 45. The cover can be constructed by using, for example, the same material or resin material as the flexible substrate 41. By providing a cover on the upper portion, it is possible to prevent the sensing unit 43 and the electrodes 44 and 45 from coming into direct contact with the object to be measured.

Next, examples of the present invention will be described. In the examples described below, a temperature sensor was manufactured using a thermoelectric conversion material, and it was verified whether or not the temperature could be detected using the manufactured temperature sensor.

<Example 1>
The temperature sensor according to Example 1 was produced by using the following method. The temperature sensor according to the first embodiment corresponds to the configuration of the temperature sensor 1 shown in FIG.

First, the electrodes 15 were formed by applying 5 mm × 10 mm silver paste on a 50 μm PET (polyethylene terephthalate) film (corresponding to the flexible substrate 12) in a straight line at 5 locations so that the intervals were 1 cm. Next, an n-type semiconductor diced to a cross section of 5 mm × 5 mm and a thickness of 15 mm, which serves as a sensing portion 13, was placed at the center of each electrode 15. Bi ₂ Te ₃ was used as the n-type semiconductor. The thermal conductivity and Seebeck coefficient of Bi ₂ Te ₃ at 300 K are 1.5 W / (m · K) and −180 μV / K, respectively.

Further, the electrode 14 was formed on a 50 μm PET film (corresponding to the flexible substrate 11 in FIG. 1). The arrangement of the electrodes 14 was set to a position corresponding to the arrangement of the electrodes 15. Then, the lower PET film (corresponding to the flexible substrate 12) and the upper PET film (corresponding to the flexible substrate 11) were bonded so that the upper portion of the sensing portion 13 and the central portion of the electrode 14 were in contact with each other. Then, the silver paste of the electrode was dried and cured under the condition of 150 ° C. for 30 minutes, and the electrodes 14 and 15 and the sensing unit 13 were integrated to prepare a temperature sensor according to Example 1.

Using the temperature sensor according to Example 1 produced in this way, the voltage difference in the sensing unit 13 was measured to determine the temperature. Specifically, the electrode portion of the electrode 15 not in contact with the sensing portion 13 was connected to one end of the voltmeter, and the electrode portion of the electrode 14 not in contact with the sensing portion 13 was connected to the other end of the voltmeter. Then, the electromotive force generated due to the temperature difference in the sensing unit 13 was measured using a voltmeter. A voltmeter was also connected to the other four electrodes to measure the electromotive force. In the following, in order to distinguish the five sensing units, they will be referred to as sensing units S11 to S15.

In an atmosphere of 27 ° C., a metal block at 40 ° C. and a metal block at 60 ° C. were placed on the upper PET film (corresponding to the flexible substrate 11). The metal block at 40 ° C. was installed at a position corresponding to the sensing units S11 to S13, and the metal block at 60 ° C. was installed at a position corresponding to the sensing units S14 to S15. Then, the electromotive force in the sensing units S11 to S15 immediately after the metal block was installed was measured using a voltmeter.

As a result, the voltage values of the sensing units S11 to S13 corresponding to the metal block at 40 ° C. were −2260 μV, −2370 μV, and −2290 μV, respectively. When the temperature of the upper part of the sensing units S11 to S13 was obtained using these voltage values, it was 39.6 ° C., 40.2 ° C., and 39.7 ° C., respectively. The voltage values of the sensing units S14 to S15 corresponding to the metal block at 60 ° C. were −5820 μV and −5900 μV, respectively. When the temperatures of the upper parts of the sensing units S14 to S15 were obtained using these voltage values, they were 59.3 ° C. and 59.8 ° C., respectively.

From the above results, it was verified that the temperature can be accurately measured by using the temperature sensor according to the first embodiment.

<Example 2>
The temperature sensor according to Example 2 was produced by using the following method. The temperature sensor according to the second embodiment corresponds to the configuration of the temperature sensor 1 shown in FIG. The temperature sensor according to the second embodiment uses a different thermoelectric conversion material as compared with the temperature sensor according to the first embodiment.

First, the electrode 15 is applied on a 50 μm PET film (corresponding to the flexible substrate 12 in FIG. 1) with a silver paste of 5 mm × 10 mm at 9 locations (3 columns in length and 3 rows in width) so as to have an interval of 1 cm. Was formed. Next, a sensing unit 13 having a size of 5 mm × 5 mm is placed in the center of each electrode 15, and an Orgacon EL-P 5015 (poly (3,4-ethylene) made by SIGMA-ALDRICH, which is a kind of polythiophene derivative, is used. A composite composed of dioxythiophene) and polystyrene sulfonic acid) was formed and dried by screen printing. Further, screen printing and drying were repeated for 9 cycles on the same portion to form a 250 μm sensing portion 13. The thermal conductivity and Zeebeck coefficient at 300K of this sensing unit are 0.2W / (m · K) and + 17μV / K, respectively.

Further, the electrode 14 was formed on a 50 μm PET film (corresponding to the flexible substrate 11). The arrangement of the electrodes 14 was set to a position corresponding to the arrangement of the electrodes 15. Then, the lower PET film (corresponding to the flexible substrate 12) and the upper PET film (corresponding to the flexible substrate 11) were bonded so that the upper portion of the sensing portion 13 and the central portion of the electrode 14 were in contact with each other. Then, the silver paste of the electrode was dried and cured under the condition of 150 ° C. for 30 minutes, and the electrodes 14 and 15 and the sensing unit 13 were integrated to prepare a temperature sensor according to Example 2.

Using the temperature sensor according to Example 2 produced in this way, the voltage difference in the sensing unit 13 was measured to determine the temperature. Specifically, the electrode portion of the electrode 15 not in contact with the sensing portion 13 was connected to one end of the voltmeter, and the electrode portion of the electrode 14 not in contact with the sensing portion 13 was connected to the other end of the voltmeter. Then, the electromotive force generated due to the temperature difference in the sensing unit 13 was measured using a voltmeter. A voltmeter was similarly connected to the other eight electrodes to measure the electromotive force. In the following, in order to distinguish the nine sensing units, they will be referred to as sensing units S21 to S29.

In an atmosphere of 27 ° C., a metal block at 40 ° C., a metal block at 60 ° C., and a metal block at 80 ° C. were placed on the upper PET film (corresponding to the flexible substrate 11), respectively. The 40 ° C. metal block is located at a position corresponding to the sensing units S21 to S23, the 60 ° C. metal block is located at a position corresponding to the sensing units S24 to S26, and the 80 ° C. metal block is located at a position corresponding to the sensing units S27 to S29. Each was installed. Then, the electromotive force in the sensing units S21 to S29 immediately after the metal block was installed was measured using a voltmeter.

As a result, the voltage values of the sensing units S21 to S23 corresponding to the metal block at 40 ° C. were 218 μV, 207 μV, and 213 μV, respectively. When the temperatures of the upper parts of the sensing units S21 to S23 were obtained using these voltage values, they were 39.8 ° C, 39.2 ° C, and 39.5 ° C, respectively.

The voltage values of the sensing units S24 to S26 corresponding to the metal block at 60 ° C. were 544 μV, 558 μV, and 546 μV, respectively. When the temperatures of the upper parts of the sensing units S24 to S26 were obtained using these voltage values, they were 59 ° C., 59.8 ° C., and 59.1 ° C., respectively.

The voltage values of the sensing units S27 to S29 corresponding to the metal block at 80 ° C. were 884 μV, 874 μV, and 879 μV, respectively. When the temperatures of the upper parts of the sensing units S27 to S29 were obtained using these voltage values, they were 79 ° C., 78.4 ° C., and 78.7 ° C., respectively.

From the above results, it was verified that the temperature can be accurately measured by using the temperature sensor according to the second embodiment. Further, even when the sensing unit 13 was formed by screen printing, the temperature could be measured using the temperature sensor.

<Example 3>
The temperature sensor according to Example 3 was produced by using the following method.
First, a 20 mm × 40 mm paper waste cloth (thickness 5 μm) was impregnated with Clevios PH1000 (PEDOT: PSS manufactured by Heraeus) and dried at room temperature for 12 hours. The long side of the paper waste containing PH1000 was folded in half, and a thick paper of 15 mm × 15 mm (thickness 570 μm) was sandwiched between them to form the sensing portion S31.

The paper waste on one side of the thick paper is called the upper side paper waste, and the paper waste on the other side is called the lower side paper waste. The thermal conductivity and Seebeck coefficient of the paper waste containing PH1000 at 300 K are 0.1 W / (m · K) and + 18 μV / K, respectively. Since the sensing unit according to the third embodiment contains thick paper, the thermal conductivity of the sensing unit is expected to be even lower.

Then, two pieces of 30 mm × 10 mm silver paste coated on a 50 μm PET film were prepared, and each silver paste was used as an upper electrode and a lower electrode. The temperature sensor according to Example 3 was produced by laminating two PET films so that the lower electrode was at the center of the lower side paper waste and the upper electrode was at the center of the upper paper waste. did.

The electrode portion not in contact with the sensing portion of the upper electrode was connected to one end of the voltmeter, and the electrode portion not in contact with the sensing portion of the lower electrode was connected to the other end of the voltmeter. Then, the electromotive force generated due to the temperature difference in the sensing unit was measured using a voltmeter.

A metal block at 40 ° C. was placed on the upper PET film in an atmosphere of 27 ° C. Then, when the electromotive force in the sensing unit S31 5 minutes after the metal block was installed was measured using a voltmeter, the voltage value was 215 μV. When the temperature of the upper part of the sensing unit S31 was obtained using this voltage value, it was 38.9 ° C.

From the above results, it was possible to form the temperature sensor even when the sensing portion was manufactured by impregnating the paper waste with a conductive organic material. Further, in the third embodiment, a low thermal conductivity region (thick paper) is provided in the sensing portion to lower the thermal conductivity of the sensing portion. Therefore, the temperature of the sensing unit could be measured even after 5 minutes had passed since the metal block was installed. That is, it is considered that the temperature of the sensing unit could be prevented from becoming uniform.

<Example 4>
The temperature sensor according to Example 4 was produced by using the following method.
First, a 20 mm × 20 mm paper waste (thickness 100 μm) was impregnated with Clevios PH1000 (PEDOT: PSS manufactured by Heraeus) and dried at room temperature for 12 hours to form a sensing portion S41. The thermal conductivity and Seebeck coefficient of the paper waste containing PH1000 at 300 K are 0.1 W / (m · K) and + 18 μV / K, respectively.

Next, two pieces of 30 mm × 10 mm silver paste coated on a 50 μm PET film were prepared, and each silver paste was used as an upper electrode and a lower electrode. Two PET films are laminated so that the lower electrode is at the center of the lower side paper waste and the upper electrode is at the center of the upper paper waste to prepare the temperature sensor according to Example 4. did.

The electrode portion not in contact with the sensing portion of the upper electrode was connected to one end of the voltmeter, and the electrode portion not in contact with the sensing portion of the lower electrode was connected to the other end of the voltmeter. Then, the electromotive force generated due to the temperature difference in the sensing unit was measured using a voltmeter.

A metal block at 40 ° C. was placed on the upper PET film in an atmosphere of 27 ° C. Then, when the electromotive force in the sensing unit S41 immediately after installing the metal block was measured using a voltmeter, the voltage value was 210 μV. When the temperature of the upper part of the sensing unit S41 was obtained using this voltage value, it was 38.7 ° C.

From the above results, it was possible to form the temperature sensor even when the sensing portion was manufactured by impregnating the paper waste with a conductive organic material.

<Example 5>
The temperature sensor according to Example 5 was produced by using the following method. The temperature sensor according to the fifth embodiment corresponds to the configuration of the temperature sensor 1 shown in FIG. The temperature sensor according to the fifth embodiment uses a different thermoelectric conversion material as compared with the temperature sensor according to the first embodiment.

First, the electrode 15 is applied on a 50 μm PET film (corresponding to the flexible substrate 12 in FIG. 1) with a silver paste of 5 mm × 10 mm at 9 locations (3 columns in length and 3 rows in width) so as to have an interval of 1 cm. Was formed.

Next, a thermoelectric conversion material containing carbon nanotubes was prepared. Specifically, 0.4 parts by mass of the single-walled carbon nanotube "TUBALL" manufactured by Kusumoto Kasei Co., Ltd., 0.4 parts by mass of the following organic compound A, and 79.2 parts by mass of N-methylpyrrolidone are prepared and mixed. did. Further, 140 parts by mass of zirconia beads (particle diameter φ1.25 mm) were added, shaken with a disperser for 2 hours, and then filtered to remove the zirconia beads to prepare a dispersion liquid containing a thermoelectric conversion material.

Next, a sensing portion 13 having a size of 5 mm × 5 mm was formed in the central portion of each electrode 15. Specifically, the dispersion liquid containing the thermoelectric conversion material prepared as described above was screen-printed on each electrode and then dried. Further, screen printing and drying were repeated for 9 cycles on the same portion to form a 250 μm sensing portion 13. The thermal conductivity and Seebeck coefficient at 300 K of this sensing unit are 8 W / (m · K) and +65.3 μV / K, respectively.

Further, the electrode 14 was formed on a 50 μm PET film (corresponding to the flexible substrate 11). The arrangement of the electrodes 14 was set to a position corresponding to the arrangement of the electrodes 15. Then, the lower PET film (corresponding to the flexible substrate 12) and the upper PET film (corresponding to the flexible substrate 11) were bonded so that the upper portion of the sensing portion 13 and the central portion of the electrode 14 were in contact with each other. Then, the silver paste of the electrode was dried and cured under the condition of 150 ° C. for 30 minutes, and the electrodes 14 and 15 and the sensing unit 13 were integrated to prepare a temperature sensor according to Example 5.

Using the temperature sensor according to Example 5 produced in this way, the voltage difference in the sensing unit 13 was measured to determine the temperature. Specifically, the electrode portion of the electrode 15 not in contact with the sensing portion 13 was connected to one end of the voltmeter, and the electrode portion of the electrode 14 not in contact with the sensing portion 13 was connected to the other end of the voltmeter. Then, the electromotive force generated due to the temperature difference in the sensing unit 13 was measured using a voltmeter. A voltmeter was similarly connected to the other eight electrodes to measure the electromotive force. In the following, in order to distinguish the nine sensing units, they will be referred to as sensing units S51 to S59.

In an atmosphere of 27 ° C., a metal block at 40 ° C., a metal block at 60 ° C., and a metal block at 80 ° C. were placed on the upper PET film (corresponding to the flexible substrate 11), respectively. The 40 ° C. metal block is located at a position corresponding to the sensing units S51 to S53, the 60 ° C. metal block is located at a position corresponding to the sensing units S54 to S56, and the 80 ° C. metal block is located at a position corresponding to the sensing units S57 to S59. Each was installed. Then, the electromotive force in the sensing units S51 to S59 immediately after the metal block was installed was measured using a voltmeter.

As a result, the voltage values of the sensing units S51 to S53 corresponding to the metal block at 40 ° C. were 816.3 μV, 835.8 μV, and 822.8 μV, respectively. When the temperatures of the upper parts of the sensing units S51 to S53 were obtained using these voltage values, they were 39.5 ° C, 39.8 ° C, and 39.6 ° C, respectively.

The voltage values of the sensing units S54 to S56 corresponding to the metal block at 60 ° C. were 2141.8 μV, 2154.9 μV, and 2122.3 μV, respectively. When the temperatures of the upper parts of the sensing units S54 to S56 were obtained using these voltage values, they were 59.8 ° C, 60 ° C, and 59.5 ° C, respectively.

The voltage values of the sensing units S57 to S59 corresponding to the metal block at 80 ° C. were 3447.8 μV, 3454.4 μV, and 3421.7 μV, respectively. When the temperatures of the upper parts of the sensing units S57 to S59 were obtained using these voltage values, they were 79.8 ° C, 79.9 ° C, and 79.4 ° C, respectively.

From the above results, it was verified that the temperature can be accurately measured by using the temperature sensor according to the fifth embodiment. Further, even when the sensing unit 13 was formed by using the thermoelectric conversion material containing carbon nanotubes, the temperature could be measured by using the temperature sensor.

Although the present invention has been described above in accordance with the above-described embodiment, the present invention is not limited to the configuration of the above-described embodiment, and is within the scope of the claimed invention within the scope of the claims of the present application. It goes without saying that it includes various modifications, modifications, and combinations that can be made by a person skilled in the art.

1, 2, 3, 4, 5 Temperature sensors 11, 12 Flexible substrate 13 Sensing unit 14, 15 Electrodes 17 Thermoelectric conversion material 18 Low thermal conductivity region 21 Base material 22 Thermoelectric conversion material 23 Insulation material (low thermal conductivity region)
31 p-type semiconductor 32 n-type semiconductor 33, 34, 35 Electrodes 41 Flexible substrate 43 Sensing section 44, 45 Electrodes 47 Thermoelectric conversion material 48 Low thermal conductivity region

Claims (12)

Flexible board and
A plurality of sensing units arranged on the flexible substrate are provided.
Each of the plurality of sensing units contains a thermoelectric conversion material, and the temperature in each of the sensing units is detected by using the voltage difference caused by the temperature gradient in the sensing unit.
Temperature sensor. The flexible substrate includes a first flexible substrate and a second flexible substrate arranged so as to face the first flexible substrate.
The plurality of sensing units are arranged between the first flexible substrate and the second flexible substrate.
Each of the sensing units is connected to the first electrode on the first flexible substrate side, and is connected to the second electrode on the second flexible substrate side.
Each of the plurality of sensing units detects the temperature on the first flexible substrate side by using the voltage difference between the first and second electrodes caused by the temperature gradient in the thickness direction of the flexible substrate. To do,
The temperature sensor according to claim 1. The sensing unit partially has a low thermal conductivity region having a lower thermal conductivity than the thermoelectric conversion material.
The low heat conduction region is configured to reduce heat conduction from the first flexible substrate side to the second flexible substrate side in the sensing unit.
The temperature sensor according to claim 2. The thermoelectric conversion material of the sensing portion has a U-shaped cross section when cut in a plane parallel to the thickness direction.
The upper surface of the U-shaped cross section is connected to the first electrode.
The lower surface of the U-shaped cross section is connected to the second electrode.
The low heat conduction region is formed between the upper surface and the lower surface of the U-shaped cross section.
The temperature sensor according to claim 3. The thermoelectric conversion material is composed of a flexible fiber base material and a conductive material impregnated in the fiber base material.
The low thermal conductivity region is constructed by using a heat insulating material.
The sensing portion is formed by bending the thermoelectric conversion material and sandwiching the heat insulating material inside.
The temperature sensor according to claim 3. The thermoelectric conversion material is formed in a plurality of strips on a flexible base material.
In the sensing unit, the thermoelectric conversion material is provided so that one end of the strip-shaped thermoelectric conversion material in the longitudinal direction is on the first flexible substrate side and the other end is on the second flexible substrate side. It is formed by bending the formed base material and sandwiching a heat insulating material constituting the low heat conductive region inside.
The temperature sensor according to claim 3. The temperature sensor according to claim 3, wherein the sensing unit is formed by impregnating a foam with a thermoelectric conversion material. The temperature sensor according to any one of claims 2 to 7, wherein the temperature sensor has a thickness of 20 mm or less. Each of the plurality of sensing units
The flexible substrate is arranged so as to extend in the in-plane direction, is connected to the first electrode on one side in the longitudinal direction of the sensing portion, and is connected to the first electrode on the other side in the longitudinal direction of the sensing portion. Is connected to
The temperature is detected by using the voltage difference between the first and second electrodes caused by the temperature gradient in the in-plane direction of the flexible substrate.
The temperature sensor according to claim 1. The sensing unit partially has a low thermal conductivity region having a lower thermal conductivity than the thermoelectric conversion material.
The low heat conduction region is configured to reduce heat conduction from the first electrode side to the second electrode side in the sensing unit.
The temperature sensor according to claim 9. The temperature sensor according to any one of claims 1 to 10, wherein the sensing unit is formed by printing the thermoelectric conversion material on the flexible substrate. The temperature sensor according to any one of claims 1 to 11, wherein the thermoelectric conversion material is made of an organic material having conductivity.

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