Thermoelectric conversion modules, thermoelectric power generation devices, liquid servers

Abstract

This invention provides a thermoelectric conversion module that can efficiently generate electromotive force by utilizing temperature differences. [Solution] The thermoelectric material-containing porous body 20 is made of a porous body containing a thermoelectric material, and a first electrode portion 11 is connected to one end of the thermoelectric material-containing porous body 20 and a second electrode portion 12 is connected to the other end, with one end of the thermoelectric material-containing porous body 20 being an easily absorbed liquid region 21 that easily absorbs liquid and the other end being a poorly absorbed liquid region 22 that does not easily absorb liquid, and the connecting portion 23 between the easily absorbed liquid region 21 and the poorly absorbed liquid region 22 The material is folded and the connecting portion 23 is made up of immersed portions 21A and 22A that are submerged in liquid, and the opposite sides of the easily absorbed region 21 and the poorly absorbed region 22 from the connecting portion 23 are made up of non-immersed portions 21B and 22B. The temperature difference between the non-immersed portion 22B and the immersed portion 22A of the poorly absorbed region 22, and the temperature difference between the immersed portion 21A and the non-immersed portion 21B of the easily absorbed region 21, generates an electromotive force between the first electrode portion 11 and the second electrode portion 12.

Description

Technical Field

[0001] The present invention relates to a thermoelectric conversion module that generates an electromotive force by the Seebeck effect using a temperature difference, a thermoelectric power generation device using this thermoelectric conversion module, and a liquid sensor.

Background Art

[0002] As the above-mentioned thermoelectric conversion module, a module using a thermoelectric conversion element capable of mutually converting thermal energy and electrical energy has been proposed. The Seebeck effect is a phenomenon in which an electromotive force is generated when a temperature difference is created between both ends of a thermoelectric conversion element, converting thermal energy into electrical energy. In recent years, the development of thermoelectric power generation using this effect has been active.

[0003] Here, for example, in Patent Documents 1 and 2, a thermoelectric conversion module using carbon nanotubes as the above-mentioned thermoelectric conversion element has been proposed. And in Non-Patent Document 1, a carbon nanotube composite material (carbon nanotube composite paper) has been proposed as a thermoelectric conversion material. Also, in Non-Patent Document 2, a technique is disclosed in which the above-mentioned carbon nanotube composite material (carbon nanotube composite paper) generates a temperature difference by the heat of vaporization when sucking up and evaporating a liquid, and generates electricity.

[0004] Here, in the above-mentioned carbon nanotube composite material (carbon nanotube composite paper), since an electromotive force is generated by sucking up a liquid, it can be considered for use as a liquid sensor. That is, when one end of the carbon nanotube composite material (carbon nanotube composite paper) is immersed in a liquid, the liquid is sucked up from one end side and evaporated at the other end side. The temperature of the other end side decreases due to the heat of vaporization during evaporation, and a temperature difference occurs between one end and the other end of the carbon nanotube composite material (carbon nanotube composite paper), generating an electromotive force. Therefore, by measuring this electromotive force, it becomes possible to detect the liquid. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 6553191 [Patent Document 2] Japanese Patent Publication No. 2022-041264 [Non-patent literature]

[0006] [Non-Patent Document 1] A. Miyama and T. Oya, Carbon Trends 7,100149(2022) [Non-Patent Document 2] Y.Kamekawa,et al.,Energies 16,8032(2023) [Overview of the project] [Problems that the invention aims to solve]

[0007] Incidentally, when one end of a conventional thermoelectric conversion module is immersed in a liquid, an electromotive force is generated by the temperature difference between the liquid temperature on the immersed end and the ambient temperature on the other end. However, if the temperature difference between the ambient temperature and the liquid temperature is small, a sufficient electromotive force cannot be obtained. Furthermore, when one end of the thermoelectric conversion module utilizing evaporation, as described above, is immersed in a liquid, an electromotive force is generated by the temperature difference between the liquid temperature on the immersed end and the temperature at the other end, which has decreased due to the heat of vaporization. However, if the temperature decrease due to the heat of vaporization is insufficient, the temperature difference becomes small, and a sufficient electromotive force cannot be obtained. As mentioned above, if sufficient electromotive force cannot be obtained, problems will arise such as the inability of a power generation device to generate electricity efficiently, and the inability of a liquid sensor to accurately detect liquid.

[0008] This invention has been made in view of the circumstances described above, and aims to provide a thermoelectric conversion module capable of efficiently generating electromotive force using a temperature difference, a thermoelectric power generation device using this thermoelectric conversion module, and a liquid sensor. [Means for solving the problem]

[0009] To solve the above problems, the thermoelectric conversion module of embodiment 1 of the present invention comprises a thermoelectric material-containing porous body made of a porous body containing a thermoelectric material, a first electrode portion connected to one end of the thermoelectric material-containing porous body and a second electrode portion connected to the other end, wherein one end of the thermoelectric material-containing porous body is an easily absorbent region that easily draws up liquid, and the other end of the thermoelectric material-containing porous body is a poorly absorbent region that does not easily draw up liquid, and the connection portion between the easily absorbent region and the poorly absorbent region is bent, and the connection portion is an immersion portion that is immersed in liquid, and the opposite side of the easily absorbent region and the poorly absorbent region from the connection portion The non-immersed portion is defined as the non-liquid-absorbing portion, and in the non-liquid-absorbing region, a temperature difference is generated between the immersed portion immersed in the liquid and the non-immersed portion exposed to the atmosphere. In the easily absorbed portion, the temperature of the non-immersed portion decreases due to the heat of vaporization when the liquid absorbed from the immersed portion evaporates in the non-immersed portion, thereby creating a temperature difference between the immersed portion and the non-immersed portion. The temperature difference between the non-immersed portion and the immersed portion in the non-liquid-absorbing region and the temperature difference between the immersed portion and the non-immersed portion in the easily absorbed portion are characterized in that an electromotive force is generated between the first electrode portion and the second electrode portion.

[0010] According to the thermoelectric conversion module of Embodiment 1 of the present invention, one end of a porous body containing a thermoelectric material is an easily absorbent region that readily absorbs liquid, and the other end of the thermoelectric material containing the porous body is a poorly absorbent region that does not readily absorb liquid. The connection between the easily absorbent region and the poorly absorbent region is bent, and the connection is an immersion portion that is submerged in liquid. The side of the easily absorbent region and the poorly absorbent region opposite the connection is a non-immersion portion. As a result, liquid is not absorbed in the poorly absorbent region, creating a temperature difference between the ambient temperature on the other end and the liquid temperature in the immersion portion. In the easily absorbent region, the temperature of the non-immersion portion decreases due to the heat of vaporization when the liquid absorbed from the immersion portion evaporates. (The temperature of the non-immersion portion of the easily absorbent region that decreases due to this heat of vaporization is called the vaporization temperature.)

[0011] Therefore, in a porous body containing thermoelectric material, a temperature difference occurs between the ambient temperature of the non-immersed portion in the poorly absorbent region and the liquid temperature of the immersed portion, and between the liquid temperature of the immersed portion in the easily absorbent region and the vaporization temperature of the non-immersed portion. This temperature difference makes it possible to efficiently generate electromotive force. Furthermore, it is preferable that the porous material is a structure that exhibits capillary action. It is also preferable that the porous material is a moisture-absorbing heat-generating element that generates heat when wet. This allows for a large temperature difference between the immersed and unimmersed parts in the easily absorbent region, enabling efficient power generation.

[0012] The thermoelectric conversion module of embodiment 2 of the present invention is characterized in that, in the thermoelectric conversion module of embodiment 1, the thermoelectric material is a carbon nanotube. According to the thermoelectric conversion module of aspect 2 of the present invention, since the thermoelectric material is carbon nanotubes, it is possible to construct a thermoelectric material-containing porous body by making the carbon nanotubes themselves porous, or it is possible to construct the thermoelectric material-containing porous body by incorporating carbon nanotubes into an insulating porous body. Furthermore, in the easily absorbed liquid region, liquid can be reliably drawn up from the immersed portion, and the heat of vaporization of the drawn-up liquid ensures a temperature difference between the immersed and unimmersed portions of the easily absorbed liquid region. Furthermore, after use, the porous body containing thermoelectric material can be incinerated and disposed of, thereby reducing the environmental burden.

[0013] The thermoelectric conversion module of embodiment 3 of the present invention is characterized in that, in the thermoelectric conversion module of embodiment 1, the thermoelectric material is an organic thermoelectric material. According to the thermoelectric conversion module of embodiment 3 of the present invention, since the thermoelectric material is an organic thermoelectric material, it is possible to construct a thermoelectric material-containing porous body by making the organic thermoelectric material itself a porous structure, or it is possible to construct the thermoelectric material-containing porous body by incorporating the organic thermoelectric material into an insulating porous body. Furthermore, in the easily absorbed liquid region, liquid can be reliably drawn up from the immersed portion, and the heat of vaporization of the drawn-up liquid ensures a temperature difference between the immersed and unimmersed portions of the easily absorbed liquid region.

[0014] The thermoelectric conversion module of embodiment 4 of the present invention is characterized in that, in the thermoelectric conversion module of embodiment 1, the thermoelectric material is a nanotube or nanowire made of a compound semiconductor or silicon semiconductor. According to the thermoelectric conversion module of aspect 4 of the present invention, since the thermoelectric material is a nanotube or nanowire made of a compound semiconductor or silicon semiconductor, it is possible to construct a thermoelectric material-containing porous body by making the nanotube or nanowire itself a porous structure, or it is possible to construct the thermoelectric material-containing porous body by incorporating the nanotube or nanowire into an insulating porous body. Furthermore, in the easily absorbed liquid region, liquid can be reliably drawn up from the immersed portion, and the heat of vaporization of the drawn-up liquid ensures a temperature difference between the immersed and unimmersed portions of the easily absorbed liquid region.

[0015] The thermoelectric conversion module according to Aspect 5 of the present invention is characterized in that, in any one of the thermoelectric conversion modules of Aspect 1 to Aspect 4, the porous body is any one of paper, thread, non-woven fabric, cloth, and lead stick, or a composite fiber containing one or more of them. According to the thermoelectric conversion module of Aspect 5 of the present invention, since the porous body is any one of paper, thread, non-woven fabric, cloth, and lead stick (wick), or a composite fiber containing one or more of them, a porous body containing a thermoelectric material can be easily produced by incorporating the thermoelectric material into these paper, thread, non-woven fabric, cloth, and lead stick (wick). Also, in the easy liquid absorption region, the liquid can be surely sucked up from the immersion part, and the temperature difference between the immersion part and the non-immersion part of the easy liquid absorption region can be ensured by the heat of vaporization of the sucked-up liquid.

[0016] The thermoelectric conversion module according to Aspect 6 of the present invention is characterized in that, in any one of the thermoelectric conversion modules of Aspect 1 to Aspect 5, the liquid is a volatile liquid that can be volatilized at normal temperature. According to the thermoelectric conversion module of Aspect 6 of the present invention, since the liquid is a volatile liquid that can be volatilized at normal temperature, the liquid sucked up in the easy liquid absorption region can be vaporized even when used at normal temperature, and an electromotive force can be surely generated by the temperature difference due to the heat of vaporization.

[0017] The thermoelectric conversion module according to Aspect 7 of the present invention is characterized in that, in any one of the thermoelectric conversion modules of Aspect 1 to Aspect 6, the porous body containing the thermoelectric material has a p-type porous body containing a p-type thermoelectric material and an n-type porous body containing an n-type thermoelectric material, and the non-immersion part of the difficult liquid absorption region of the p-type porous body containing the thermoelectric material and the non-immersion part of the difficult liquid absorption region of the n-type porous body containing the thermoelectric material, or the non-immersion part of the easy liquid absorption region of the p-type porous body containing the thermoelectric material and the non-immersion part of the easy liquid absorption region of the n-type porous body containing the thermoelectric material are electrically connected.

[0018] According to the thermoelectric conversion module of aspect 7 of the present invention, in the porous body containing a p-type thermoelectric material and the porous body containing an n-type thermoelectric material, since the electromotive force generated by the temperature difference is reversed, the non-immersed part of the liquid-repellent region of the porous body containing the p-type thermoelectric material and the non-immersed part of the liquid-repellent region of the porous body containing the n-type thermoelectric material, or the non-immersed part of the liquid-absorbent region of the porous body containing the p-type thermoelectric material and the non-immersed part of the liquid-absorbent region of the porous body containing the n-type thermoelectric material, are electrically connected, so that the porous body containing the p-type thermoelectric material and the porous body containing the n-type thermoelectric material are connected in series, and a larger electromotive force can be generated.

[0019] The thermoelectric conversion module of aspect 8 of the present invention is any one of the thermoelectric conversion modules of aspects 1 to 6, and has a plurality of the porous bodies containing the thermoelectric material. The porous body containing the thermoelectric material is either a porous body containing a p-type thermoelectric material containing a p-type thermoelectric material or a porous body containing an n-type thermoelectric material containing an n-type thermoelectric material. The non-immersed part of the liquid-repellent region of the porous body containing the thermoelectric material and the non-immersed part of the liquid-absorbent region of the porous body containing the thermoelectric material are electrically connected by a conductor-containing porous body composed of a porous body containing a conductor.

[0020] According to the thermoelectric conversion module of aspect 8 of the present invention, the non-immersed part of the liquid-repellent region of the porous body containing the thermoelectric material and the non-immersed part of the liquid-absorbent region of the porous body containing the thermoelectric material, which is composed of either a porous body containing a p-type thermoelectric material containing a p-type thermoelectric material or a porous body containing an n-type thermoelectric material containing an n-type thermoelectric material, are electrically connected by a conductor-containing porous body composed of a porous body containing a conductor. Therefore, the porous bodies containing the thermoelectric material are connected in series, and a larger electromotive force can be generated. In addition, since they are connected via the conductor-containing porous body, a temperature difference between the non-immersed part of the liquid-repellent region of the porous body containing the thermoelectric material and the non-immersed part of the liquid-absorbent region of the porous body containing the thermoelectric material can be ensured.

[0021] A thermoelectric power generation device according to aspect 9 of the present invention has one thermoelectric conversion module from any one of aspects 1 to 8, and is characterized by generating electricity based on the temperature difference between the non-immersed portion and the immersed portion in the poorly liquid-absorbing region and the temperature difference between the immersed portion and the non-immersed portion in the easily liquid-absorbing region.

[0022] According to the thermoelectric power generation device of embodiment 9 of the present invention, it has one of the thermoelectric conversion modules described in embodiments 1 to 8 above, and is configured to generate electricity using the temperature difference between the non-immersed part and the immersed part in the poorly liquid-absorbing region and the temperature difference between the immersed part and the non-immersed part in the easily liquid-absorbing region. Therefore, it is possible to utilize the temperature difference between the ambient temperature and the liquid temperature and the temperature difference between the liquid temperature and the vaporization temperature, making it possible to generate electricity efficiently.

[0023] A liquid sensor according to embodiment 10 of the present invention has a thermoelectric conversion module from any one of embodiments 1 to 8, and is characterized by detecting the presence or absence of liquid by detecting an electrical signal generated by the temperature difference between the non-immersed portion and the immersed portion in the non-liquid-absorbent region and the temperature difference between the immersed portion and the non-immersed portion in the easily absorbed region when the liquid is immersed in the immersion portion.

[0024] According to the liquid sensor of embodiment 10 of the present invention, it has one of the thermoelectric conversion modules described in embodiments 1 to 8 above, and is configured to sense the presence or absence of liquid by detecting electrical signals generated by the temperature difference between the non-immersed part and the immersed part in the non-liquid-absorbing region and the temperature difference between the immersed part and the non-immersed part in the easily absorbed liquid region. Therefore, it is possible to accurately sense the presence or absence of liquid by utilizing the temperature difference between the ambient temperature and the liquid temperature and the temperature difference between the liquid temperature and the vaporization temperature. [Effects of the Invention]

[0025] According to the present invention, it is possible to provide a thermoelectric conversion module capable of efficiently generating electromotive force by utilizing a temperature difference, a thermoelectric power generation device using this thermoelectric conversion module, and a liquid sensor. [Brief explanation of the drawing]

[0026] [Figure 1] This is a schematic diagram illustrating a thermoelectric conversion module, which is a first embodiment of the present invention. [Figure 2] Figure 1 shows cross-sectional photographs of the easily absorbed and poorly absorbed regions of the thermoelectric conversion module. (a) is a cross-sectional photograph of the poorly absorbed region, and (b) is a cross-sectional photograph of the easily absorbed region. [Figure 3] This is a schematic diagram illustrating a method for manufacturing a thermoelectric material-containing porous body used in the thermoelectric conversion module of the present invention. [Figure 4] This is a schematic diagram illustrating a thermoelectric conversion module, which is a second embodiment of the present invention. [Figure 5] This is a schematic diagram illustrating a thermoelectric conversion module, which is a third embodiment of the present invention. [Figure 6] This is an explanatory diagram showing the embodiments of the inventive example, Comparative Example 1, and Comparative Example 2 in the examples. [Modes for carrying out the invention]

[0027] Embodiments of the present invention will be described below with reference to the attached drawings. The embodiments described below are provided specifically to better illustrate the spirit of the invention and do not limit the present invention unless otherwise specified. Furthermore, the drawings used in the following description may be enlarged for convenience to clearly illustrate the features of the present invention, and the dimensional ratios of each component may not be the same as those in reality.

[0028] (First embodiment) First, a thermoelectric conversion module, which is the first embodiment of the present invention, will be described. As shown in Figure 1, the thermoelectric conversion module 10 according to this embodiment comprises a thermoelectric material-containing porous body 20 made of a porous body containing a thermoelectric material, and a first electrode section 11 and a second electrode section 12 connected to the thermoelectric material-containing porous body 20.

[0029] Furthermore, as shown in Figure 1, this embodiment includes a liquid holding section 30 in which the liquid 3 is held. The liquid 3 held in the liquid holding section 30 is preferably a volatile liquid that evaporates at room temperature (20°C). Examples of volatile liquids include water, various alcohols, and cleaning solutions. In this embodiment, the liquid 3 is water.

[0030] In this embodiment, as shown in Figure 1, the thermoelectric material-containing porous body 20 has a readily absorbent region 21 at one end that easily absorbs liquid and a non-absorbent region 22 at the other end that does not easily absorb liquid, and is bent at the connecting portion 23 between the readily absorbent region 21 and the non-absorbent region 22. The connecting portion 23 is configured to be immersed in the liquid 3, while one end and the other end of the thermoelectric material-containing porous body 20 are not immersed in the liquid. Specifically, in the easily absorbed liquid region 21, the connecting portion 23 is the immersed portion 21A, and the end opposite to the immersed portion 21A (one end of the thermoelectric material-containing porous body 20) is the non-immersed portion 21B. In the poorly absorbed liquid region 22, the connecting portion 23 is the immersed portion 22A, and the end opposite to the immersed portion 22A (the other end of the thermoelectric material-containing porous body 20) is the non-immersed portion 22B.

[0031] Here, the easily absorbed liquid region 21 and the poorly absorbed liquid region 22 can be formed as follows. For example, by press-forming the other end of the thermoelectric material-containing porous body 20 to crush the internal communication holes that form liquid channels, an easily absorbed region 21 and a poorly absorbed region 22 with different liquid absorption properties can be formed. Alternatively, by sealing the internal communication holes on the other end of the thermoelectric material-containing porous body 20 with resin, an easily absorbed region 21 and a poorly absorbed region 22 with different liquid absorption properties can be formed.

[0032] Furthermore, by improving the wettability of one end of the thermoelectric material-containing porous body 20 to a liquid and decreasing the wettability of the other end of the thermoelectric material-containing porous body 20, it is possible to form an easily absorbed region 21 and a poorly absorbed region 22 with different liquid absorption properties. In other words, if the liquid is water, by applying a hydrophilic treatment to one end of the thermoelectric material-containing porous body 20 and a hydrophobic treatment to the other end of the thermoelectric material-containing porous body 20, it is possible to form an easily absorbed region 21 and a poorly absorbed region 22 with different liquid absorption properties.

[0033] In this embodiment, as shown in Figure 2, the other end of the thermoelectric material-containing porous body 20 is press-formed to crush the internal communication holes that form the liquid flow path, thereby forming an easily absorbed liquid region 21 and a poorly absorbed liquid region 22. In the poorly absorbent region 22, as shown in Figure 2(a), it can be confirmed that the internal communication holes are collapsed. In the easily absorbent region 21, as shown in Figure 2(b), internal communication holes are present. In this way, the porous body 20 containing the thermoelectric material forms an easily absorbent region 21 and a poorly absorbent region 22, each with different liquid absorption properties.

[0034] In this embodiment, it is preferable that the thermoelectric material-containing porous body 20 is composed of a porous body containing a thermoelectric material whose Seebeck coefficient has an absolute value of 3 μV / K or more. Furthermore, it is preferable that the thermoelectric material contained in the thermoelectric material-containing porous body 20 has a Seebeck coefficient with an absolute value of 40 μV / K or higher.

[0035] Thermoelectric materials possess semiconductor properties, specifically those of a p-type or n-type semiconductor. In this embodiment, the thermoelectric material-containing porous body 20 may be either a p-type or n-type semiconductor. Examples of thermoelectric materials include (a) carbon nanotubes (CNTs), (b) organic thermoelectric materials, (c) nanotubes or nanowires made of compound semiconductors or silicon semiconductors, (d) noble metal compounds, (e) carbon materials, and (f) metals such as Bi, Co, Fe, and Ni. Furthermore, thermoelectric materials (a) through (f) may be combined and used in their entirety.

[0036] Here, (a) in the case of carbon nanotubes, the thermoelectric material-containing porous body 20 can be constructed by making the carbon nanotubes themselves into a porous structure (paper, thread, nonwoven fabric, cloth, reed stick, etc.). Alternatively, the thermoelectric material-containing porous body 20 can be constructed by incorporating carbon nanotubes into other porous materials. The Seebeck coefficient of carbon nanotubes is approximately 5-170 μV / K.

[0037] (b) Examples of organic thermoelectric materials include PEDOT-based materials (PEDOT:PSS, PEDOT:Tos, etc.), π-conjugated nickel complex-based materials (poly(nickel-ethylenetetrathiolate)), and N-DMBI-based materials (N,N-dimethyl-2-phenyl-2,3-dihydro-1H-benzoimidazole). The Seebeck coefficient for PEDOT:PSS is approximately 10-100 μV / K. The Seebeck coefficient for PEDOT:Tos is approximately 40-210 μV / K. The Seebeck coefficient for π-conjugated nickel complex systems is approximately -16-140 μV / K. In the case of organic thermoelectric materials, a thermoelectric material-containing porous body 20 can be constructed by making the organic thermoelectric material itself a porous structure (paper, yarn, nonwoven fabric, cloth, reed stick, etc.). Alternatively, a thermoelectric material-containing porous body 20 can be constructed by incorporating the organic thermoelectric material into another porous body.

[0038] (c) In the case of nanotubes or nanowires made of compound semiconductors or silicon semiconductors, the thermoelectric material-containing porous body 20 can be constructed by incorporating one or more types of nanotubes or nanowires made of boron nitride nanotubes, compound semiconductors such as Si nanowires or Bi2Te3 nanowires, or silicon semiconductors into another porous body.

[0039] (d) Examples of noble metal compounds include copper compounds, silver compounds, gold compounds, platinum compounds, etc. Specifically, compounds of noble metal elements (Cu, Ag, Au, Pt) and S, Se, Te are preferred. In the case of precious metal compounds, the thermoelectric material-containing porous body 20 can be constructed by incorporating the precious metal compound into another porous body.

[0040] (e) Examples of carbon materials include carbon black and graphite. In the case of carbon materials, a thermoelectric material-containing porous body 20 can be constructed by incorporating carbon material into another porous body.

[0041] (f) In the case of metals such as Bi, Co, Fe, and Ni, the thermoelectric material-containing porous body 20 can be constructed by incorporating the metal Bi, Co, Fe, and Ni into other porous bodies. It is preferable to incorporate the metal Bi, Co, Fe, and Ni into other porous bodies by a plating method.

[0042] In this embodiment, the thermoelectric material-containing porous body 20 is a porous body impregnated with carbon nanotubes (CNTs), and has semiconductor properties, specifically those of a p-type or n-type semiconductor. In this embodiment, the thermoelectric material-containing porous body 20 may be either a p-type or n-type semiconductor.

[0043] As the porous material, fibrous materials such as paper, yarn, nonwoven fabric, cloth, and reed sticks are preferred. In this embodiment, the porous material is paper, and the thermoelectric material-containing porous material 20 is CNT-containing paper. The fibers may be natural fibers or artificial fibers, and paper, yarn, nonwoven fabric, cloth, reed sticks, etc., made by combining multiple fibers may also be used.

[0044] Furthermore, the porous material is preferably a structure that exhibits capillary action, and in addition to paper, thread, nonwoven fabric, cloth, and reed sticks, boards, films, meshes, hollow fibers, etc., can also be used. The porous material is preferably an insulating porous material. The porous material is preferably a moisture-absorbing and heat-generating element, and is preferably one that generates heat through the hydration reaction on the material surface caused by wetting, and through the release of strain associated with the swelling of the material.

[0045] Next, an example of a method for manufacturing the thermoelectric material-containing porous body 20 (CNT-containing paper) will be explained with reference to Figure 3.

[0046] First, pulp fibers are added to pure water and thoroughly stirred to obtain a pulp dispersion in which the pulp fibers are dispersed. Furthermore, a carbon nanotube dispersion is obtained by adding single-walled carbon nanotubes to pure water and stirring thoroughly. In this case, it is preferable that the amount of single-walled carbon nanotubes is 0.8% by mass or more and 8.0% by mass or less relative to the weight of the pulp fibers, which are the raw material for paper. It is also not necessary to add a dispersant. In addition, it is preferable to perform ultrasonic treatment for about 30 minutes when obtaining the carbon nanotube dispersion.

[0047] Next, as shown in Figure 3(a), the pulp suspension and the carbon nanotube dispersion are mixed and stirred to obtain a mixture. At this time, the carbon nanotubes will adhere to the pulp fibers. Then, as shown in Figure 3(b), the above-mentioned mixture is made into paper and dried to obtain a porous body containing thermoelectric material (CNT-containing paper).

[0048] Next, as shown in Figure 3(c), the obtained thermoelectric material-containing porous body (CNT-containing paper) is partially subjected to hot pressing to crush the internal communication pores and form easily absorbent regions 21 and poorly absorbent regions 22 with different liquid absorption properties. Then, the material is cut so that one end becomes an easily absorbent region 21 that has not been heat-pressed, and the other end becomes a poorly absorbent region 22 that has been heat-pressed. Then, by performing a folding process at the connecting portion 23 between the easily absorbed liquid region 21 and the poorly absorbed liquid region 22, the thermoelectric material-containing porous body 20 (CNT-containing paper) shown in Figure 1 is formed.

[0049] In the thermoelectric conversion module 10 of this embodiment, as shown in Figure 1, when the connecting portion 23 of the thermoelectric material-containing porous body 20 is immersed in liquid (water), in the easily absorbed region 21, liquid (water) is drawn up from the immersed portion 21A, and the liquid 3 evaporates in the non-immersed portion 21B. The heat of vaporization at this time lowers the temperature of the non-immersed portion 21B of the easily absorbed region 21 to the vaporization temperature. On the other hand, in the poorly absorbed region 22, the liquid 3 is not absorbed from the immersed portion 22A, and the non-immersed portion 22B of the poorly absorbed region becomes the ambient temperature. Here, the typical temperature relationship is ambient temperature > liquid temperature > vaporization temperature. In the low-liquid-absorption region 22, an electromotive force is generated by the temperature difference between the ambient temperature of the non-immersed portion 22B and the liquid temperature of the immersed portion 22A. In the easily-absorbent region 21, an electromotive force is generated by the temperature difference between the liquid temperature of the immersed portion 21A and the vaporization temperature of the non-immersed portion 21B.

[0050] In this embodiment of the thermoelectric power generation device, the above-described thermoelectric conversion module 10 is provided, and the connecting portion 23 of the thermoelectric material-containing porous body 20 is immersed in the liquid 3. The device is configured to generate electricity from the electromotive force generated by the temperature difference between the ambient temperature of the non-immersed portion 22B of the poorly absorbent region 22 and the liquid temperature of the immersed portion 22A, and from the electromotive force generated by the temperature difference between the liquid temperature of the immersed portion 21A of the easily absorbent region 21 and the vaporization temperature of the non-immersed portion 21B.

[0051] In this embodiment of the liquid sensor, the above-described thermoelectric conversion module 10 is provided, and when liquid 3 is present at the location where the connecting portion 23 of the thermoelectric material-containing porous body 20 is located, the presence of liquid 3 is detected by the electromotive force generated by the temperature difference between the ambient temperature of the non-immersed portion 22B of the poorly absorbent region 22 and the liquid temperature of the immersed portion 22A, and by the electromotive force generated by the temperature difference between the liquid temperature of the immersed portion 21A of the easily absorbent region 21 and the vaporization temperature of the non-immersed portion 21B.

[0052] In the thermoelectric conversion module 10 of this embodiment, which has the above configuration, one end of the thermoelectric material-containing porous body 20, which is made of a porous body containing a thermoelectric material, is an easily absorbent region 21 that easily absorbs liquid 3, and the other end of the thermoelectric material-containing porous body 20 is a poorly absorbent region 22 that does not easily absorb liquid 3. The connecting portion 23 between the easily absorbent region 21 and the poorly absorbent region 22 is bent, and the connecting portion 23 is immersed in the liquid. Therefore, the non-immersed parts 21B and 22B are located on the opposite side of the connecting part 23 between the easily absorbed liquid region 21 and the poorly absorbed liquid region 22. In the poorly absorbed liquid region 22, liquid 3 is not drawn up from the immersed part 22A, resulting in a temperature difference between the ambient temperature of the non-immersed part 22B and the liquid temperature of the immersed part 22A. In the easily absorbed liquid region 21, the temperature of the non-immersed part 21B decreases due to the heat of vaporization when the liquid 3 drawn up from the immersed part 21A evaporates, resulting in a temperature difference.

[0053] As a result, in the thermoelectric conversion module 10 of this embodiment, a temperature difference is created between the ambient temperature of the non-immersed portion 22B of the poorly liquid-absorbing region 22 of the thermoelectric material-containing porous body 20 and the liquid temperature of the immersed portion 22A, and between the liquid temperature of the immersed portion 21A of the easily liquid-absorbing region 21 and the vaporization temperature of the non-immersed portion 21B. These temperature differences make it possible to efficiently generate electromotive force.

[0054] Furthermore, in the thermoelectric conversion module 10 of this embodiment, if the thermoelectric material is carbon nanotubes, it is possible to construct a thermoelectric material-containing porous body by making the carbon nanotubes themselves porous, or by incorporating carbon nanotubes into an insulating porous body. Furthermore, in the easily absorbed liquid region 21, the liquid 3 can be reliably drawn up from the immersed portion 21A, and the heat of vaporization of the drawn-up liquid 3 can ensure a temperature difference between the immersed portion 21A and the non-immersed portion 21B of the easily absorbed liquid region 21. Furthermore, after use, the porous body 20 containing thermoelectric material can be incinerated and disposed of, thereby reducing the environmental burden.

[0055] Furthermore, in the thermoelectric conversion module 10 of this embodiment, if the porous material is a composite fiber containing one or more of the following: paper, yarn, nonwoven fabric, cloth, or reed stick, then the thermoelectric material-containing porous material 20 can be easily produced by incorporating carbon nanotubes into the paper, yarn, nonwoven fabric, cloth, or reed stick. In addition, the liquid 3 can be reliably drawn up from the immersion portion 21A of the easily absorbent liquid region 21 of the thermoelectric material-containing porous material 20. Furthermore, after use, the porous body 20 containing thermoelectric material can be incinerated and disposed of, thereby reducing the environmental burden.

[0056] Furthermore, in the thermoelectric conversion module 10 of this embodiment, if the liquid 3 is a volatile liquid that can evaporate at room temperature, even when used at room temperature, the liquid 3 drawn up from the immersed portion 21A can be efficiently vaporized in the non-immersed portion 21B within the easily absorbed liquid region 21 of the thermoelectric material-containing porous body 20, and an electromotive force can be generated by the temperature difference between the liquid temperature in the immersed portion 21A and the vaporization temperature in the non-immersed portion 21B.

[0057] In this embodiment of the thermoelectric power generation device, the thermoelectric conversion module 10 described above is included, and power is generated by the temperature difference between the non-immersed portion 22B and the immersed portion 22A of the non-liquid-absorbing region 22, and the temperature difference between the immersed portion 21A and the non-immersed portion 21B of the easily absorbed region 21. Therefore, it is possible to utilize the temperature difference between the ambient temperature and the liquid temperature, and the temperature difference between the liquid temperature and the vaporization temperature, making it possible to generate power efficiently.

[0058] In this embodiment of the liquid sensor, the thermoelectric conversion module 10 described above is included, and when liquid is present in the immersed portion 21A of the easily absorbed region 21, the presence or absence of liquid 3 can be accurately detected by detecting the electrical signals generated by the temperature difference between the non-immersed portion 22B and the immersed portion 22A of the poorly absorbed region 22, and the temperature difference between the immersed portion 21A and the non-immersed portion 21B of the easily absorbed region 21.

[0059] (Second Embodiment) Next, a thermoelectric conversion module 110, which is a second embodiment of the present invention, will be described. As shown in Figure 4, the thermoelectric conversion module 110 according to this embodiment includes a thermoelectric material-containing porous body 120 made of a porous body containing a thermoelectric material, specifically a p-type thermoelectric material-containing porous body 120P and an n-type thermoelectric material-containing porous body 120N. Furthermore, the device includes a first electrode section 111 and a second electrode section 112 connected to the thermoelectric material-containing porous body 120.

[0060] As shown in Figure 4, the p-type thermoelectric material-containing porous body 120P(120) has a liquid-absorbing region 121P(121) at one end that easily absorbs liquid and a liquid-reducing region 122P(122) at the other end that does not easily absorb liquid, and is bent at the connection point 123P(123) between the liquid-absorbing region 121P(121) and the liquid-reducing region 122P(122).

[0061] The connecting portion 123P is configured to be immersed in the liquid 3, while one end and the other end of the p-type thermoelectric material-containing porous body 120P are not immersed in the liquid. Specifically, in the easily absorbed liquid region 121P, the connecting portion 123P is the immersed portion 121PA, and the end opposite to the immersed portion 121PA (one end of the p-type thermoelectric material-containing porous body 120P) is the non-immersed portion 121PB. In the poorly absorbed liquid region 122P, the connecting portion 123P is the immersed portion 122PA, and the end opposite to the immersed portion 122PA (the other end of the p-type thermoelectric material-containing porous body 120P) is the non-immersed portion 122PB.

[0062] Furthermore, as shown in Figure 4, the n-type thermoelectric material-containing porous body 120N(120) has a liquid-absorbing region 121N(121) at one end that easily absorbs liquid, and a liquid-reducing region 122N(122) at the other end that does not easily absorb liquid, and is bent at the connecting portion 123N(123) between the liquid-absorbing region 121N(121) and the liquid-reducing region 122N(122).

[0063] The connecting portion 123N is configured to be immersed in the liquid 3, while one end and the other end of the n-type thermoelectric material-containing porous body 120N are not immersed in the liquid 3. Specifically, in the easily absorbed liquid region 121N, the connecting portion 123N is the immersed portion 121NA, and the end opposite to the immersed portion 121NA (one end of the n-type thermoelectric material-containing porous body 120N) is the non-immersed portion 121NB. In the poorly absorbed liquid region 122N, the connecting portion 123N is the immersed portion 122NA, and the end opposite to the immersed portion 122NA (the other end of the n-type thermoelectric material-containing porous body 120N) is the non-immersed portion 122NB.

[0064] In this embodiment, as shown in Figure 4, the non-immersed portion 122PB of the poorly liquid-absorbing region 122P of the p-type thermoelectric material-containing porous body 120P and the non-immersed portion 122NB of the poorly liquid-absorbing region 122N of the n-type thermoelectric material-containing porous body 120N are electrically connected. In this embodiment of the thermoelectric conversion module 110, the portion where the non-immersed portion 122PB of the poorly liquid-absorbing region 122P of the p-type thermoelectric material-containing porous body 120P and the non-immersed portion 122NB of the poorly liquid-absorbing region 122N of the n-type thermoelectric material-containing porous body 120N are connected becomes the ambient temperature.

[0065] In the p-type thermoelectric material-containing porous body 120P, the immersed portion 122PA of the poorly absorbent region 122P and the immersed portion 121PA of the easily absorbent region 121P reach the liquid temperature, while the non-immersed portion 121PB of the easily absorbent region 121P reaches the vaporization temperature. On the other hand, in the n-type thermoelectric material-containing porous body 120N, the immersed portion 122NA of the poorly absorbent region 122N and the immersed portion 121NA of the easily absorbent region 121N reach the liquid temperature, while the non-immersed portion 121NB of the easily absorbent region 121N reaches the vaporization temperature.

[0066] Thus, in the thermoelectric conversion module 110 according to this embodiment, a temperature difference in opposite directions occurs between the p-type thermoelectric material-containing porous body 120P and the n-type thermoelectric material-containing porous body 120N. However, since the electromotive force generated by the temperature difference between the p-type thermoelectric material-containing porous body 120P and the n-type thermoelectric material-containing porous body 120N is in opposite directions, a large electromotive force is generated by the temperature difference between the ambient temperature, liquid temperature, and vaporization temperature.

[0067] According to the thermoelectric conversion module 110 of this embodiment, as described above, the non-immersed portion 122PB of the poorly liquid-absorbing region 122P of the p-type thermoelectric material-containing porous body 120P and the non-immersed portion 122NB of the poorly liquid-absorbing region 122N of the n-type thermoelectric material-containing porous body 120N are electrically connected. As a result, the p-type thermoelectric material-containing porous body 120P and the n-type thermoelectric material-containing porous body 120N are connected in series, and sufficient electromotive force is generated in the p-type thermoelectric material-containing porous body 120P and the n-type thermoelectric material-containing porous body 120N, respectively, due to the temperature difference between the ambient temperature, liquid temperature, and vaporization temperature, and an even larger electromotive force can be generated. Therefore, when the thermoelectric conversion module 110 according to this embodiment is used in a thermoelectric power generation device, it becomes possible to generate electricity even more efficiently by utilizing the temperature difference. Furthermore, when the thermoelectric conversion module 110 according to this embodiment is used as a liquid sensor, the presence or absence of liquid can be detected with even greater accuracy and speed.

[0068] (Third embodiment) Next, a thermoelectric conversion module 210, which is a third embodiment of the present invention, will be described. As shown in Figure 5, the thermoelectric conversion module 210 according to this embodiment has a plurality of p-type thermoelectric material-containing porous bodies 220, which are made of a porous body containing a thermoelectric material (first p-type thermoelectric material-containing porous body 220P1, second p-type thermoelectric material-containing porous body 220P2). Furthermore, it includes a first electrode section 211 and a second electrode section 212 connected to the thermoelectric material-containing porous body 220.

[0069] As shown in Figure 5, the first p-type thermoelectric material-containing porous body 220P1(220) has a readily absorbent region 221P1(221) at one end that easily absorbs liquid and a non-absorbent region 222P1(222) at the other end, and is bent at the connection point 223P1(223) between the readily absorbent region 221P1(221) and the non-absorbent region 222P1(222).

[0070] The connecting portion 223P1 is configured to be immersed in the liquid 3, while one end and the other end of the first p-type thermoelectric material-containing porous body 220P1 are configured not to be immersed in the liquid 3. Specifically, in the easily absorbed liquid region 221P1, the connecting portion 223P1 is the immersed portion 221P1A, and the end opposite to the immersed portion 221P1A (one end of the first p-type thermoelectric material-containing porous body 220P1) is the non-immersed portion 221P1B. In the poorly absorbed liquid region 222P1, the connecting portion 223P1 is the immersed portion 222P1A, and the end opposite to the immersed portion 222P1A (the other end of the first p-type thermoelectric material-containing porous body 220P1) is the non-immersed portion 222P1B.

[0071] As shown in Figure 5, the second p-type thermoelectric material-containing porous body 220P2(220) has a readily absorbent region 221P2(221) at one end that easily absorbs liquid and a non-absorbent region 222P2(222) at the other end that does not easily absorb liquid, and is bent at the connection point 223P2(223) between the readily absorbent region 221P2(221) and the non-absorbent region 222P2(222).

[0072] The connecting portion 223P2 is configured to be immersed in the liquid 3, while one end and the other end of the second p-type thermoelectric material-containing porous body 220P2 are not immersed in the liquid. Specifically, in the easily absorbed liquid region 221P2, the connecting portion 223P2 is the immersed portion 221P2A, and the end opposite to the immersed portion 221P2A (one end of the second p-type thermoelectric material-containing porous body 220P2) is the non-immersed portion 221P2B. In the poorly absorbed liquid region 222P2, the connecting portion 223P2 is the immersed portion 222P2A, and the end opposite to the immersed portion 222P2A (the other end of the second p-type thermoelectric material-containing porous body 220P2) is the non-immersed portion 222P2B.

[0073] In this embodiment, as shown in Figure 5, the non-immersed portion 222P1B of the poorly liquid-absorbing region 222P1 of the first p-type thermoelectric material-containing porous body 220P1 and the non-immersed portion 221P2B of the easily liquid-absorbing region 221P2 of the second p-type thermoelectric material-containing porous body 220P2 are electrically connected by a conductive porous body 250 made of a porous body containing a conductor. In this embodiment, the conductive porous body 250 connects the non-immersed portion 222P1B of the poorly liquid-absorbing region 222P1 of the first p-type thermoelectric material-containing porous body 220P1 and the non-immersed portion 221P2B of the easily liquid-absorbing region 221P2 of the second p-type thermoelectric material-containing porous body 220P2 at a distance from each other, resulting in a thermally isolated structure.

[0074] In this embodiment of the thermoelectric conversion module 210, the non-immersed portion 222P1B of the poorly absorbent region 222P1 of the first p-type thermoelectric material-containing porous body 220P1, and the non-immersed portion 122P2B of the poorly absorbent region 222P2 of the second p-type thermoelectric material-containing porous body 220P2 are at ambient temperature. Furthermore, the immersed portions 221A1 and 222A1 of the first p-type thermoelectric material-containing porous body 220P1, and the immersed portions 221A2 and 222A2 of the second p-type thermoelectric material-containing porous body 220P2, reach liquid temperature. Furthermore, the non-immersed portion 221P1B of the easily absorbed liquid region 221P1 of the first p-type thermoelectric material-containing porous body 220P1, and the non-immersed portion 221P2B of the easily absorbed liquid region 221P2 of the second p-type thermoelectric material-containing porous body 220P2, are at the vaporization temperature.

[0075] As described above, in the thermoelectric conversion module 210 according to this embodiment, the first p-type thermoelectric material-containing porous body 220P1 and the second p-type thermoelectric material-containing porous body 220P2 are connected in series, and the non-immersed portion 222P1B of the poorly liquid-absorbing region 222P1 of the first p-type thermoelectric material-containing porous body 220P1 and the non-immersed portion 221P2B of the easily liquid-absorbing region 221P2 of the second p-type thermoelectric material-containing porous body 220P2 are connected at a distance from each other, resulting in a thermally isolated structure. Therefore, a large electromotive force is generated by the temperature difference between the ambient temperature, the liquid temperature, and the vaporization temperature.

[0076] According to the thermoelectric conversion module 210 of this embodiment, as described above, the first p-type thermoelectric material-containing porous body 220P1 and the second p-type thermoelectric material-containing porous body 220P2 are connected in series, and sufficient electromotive force is generated in the first p-type thermoelectric material-containing porous body 220P1 and the second p-type thermoelectric material-containing porous body 220P2, respectively, due to the temperature difference between the ambient temperature, liquid temperature, and vaporization temperature, and an even larger electromotive force can be generated. Therefore, when the thermoelectric conversion module 210 according to this embodiment is used in a thermoelectric power generation device, it becomes possible to generate electricity even more efficiently by utilizing the temperature difference. Furthermore, when the thermoelectric conversion module 210 according to this embodiment is used as a liquid sensor, the presence or absence of liquid can be detected with even greater accuracy and speed.

[0077] Although embodiments of the present invention have been described above, the present invention is not limited thereto and can be modified as appropriate without departing from the technical spirit of the invention. For example, in this embodiment, water was used as the liquid for the explanation, but other liquids may also be used. Furthermore, although this embodiment has been described as having a liquid holding section 30 for holding liquid 3, it is not limited to this, and there are no particular limitations as long as the immersion section is immersed in the liquid.

[0078] Furthermore, although this embodiment has described the use of a thermoelectric material-containing porous body (thermoelectric material-containing paper) in which the porous body is paper, it is not limited to this, and a thermoelectric material-containing porous body (thermoelectric material-containing yarn) in which the porous body is yarn may also be used, a thermoelectric material-containing porous body (thermoelectric material-containing cloth) in which the porous body is cloth may also be used, or a thermoelectric material-containing porous body (thermoelectric material-containing lead stick) in which the porous body is a lead stick may also be used. Furthermore, thermoelectric material-containing yarns (CNT-containing yarns) impregnated with carbon nanotubes as thermoelectric materials can be manufactured by the following method.

[0079] The method for incorporating carbon nanotubes into yarn is basically the same as manual dyeing techniques. One method involves immersing the base yarn in a carbon nanotube dispersion, then heating the dispersion to a temperature below boiling point (around 60°C) to evaporate the water, thereby coating the yarn with concentrated carbon nanotubes. This impregnation method allows for the incorporation of more carbon nanotubes into the yarn.

[0080] The base yarn (substrate) necessary for producing CNT-containing yarn is typically made from naturally derived yarns such as cotton, linen, wool, or silk, or from chemically synthesized synthetic fibers such as polyester or nylon. However, a blend of these yarns may also be used. In the case of yarns that do not absorb dye, such as synthetic fibers, a carbon nanotube dispersion may be applied to its surface and dried to produce a CNT-containing yarn. [Examples]

[0081] The results of the verification experiments conducted to confirm the effects of the present invention are described below.

[0082] First, as described in the section on the first embodiment, a thermoelectric material-containing porous body (CNT-containing paper) containing carbon nanotubes (CNTs) as the thermoelectric material was prepared.

[0083] (Example of the present invention) As shown in Figure 6, in this example of the present invention, the other end of the thermoelectric material-containing porous body (CNT-containing paper) is heat-pressed to make the thermoelectric material-containing porous body (CNT-containing paper) have a region that easily absorbs liquid and a region that does not easily absorb liquid, and a thermoelectric conversion module is prepared in which the structure is folded at the connection between these liquid-absorbing and liquid-not-absorbing regions.

[0084] (Comparative Example 1) As shown in Figure 6, in Comparative Example 1, no heat press processing was performed on the thermoelectric material-containing porous body (CNT-containing paper), and the entire thermoelectric material-containing porous body (CNT-containing paper) was made into an easily absorbent region. A thermoelectric conversion module was prepared with a structure in which the thermoelectric material-containing porous body (CNT-containing paper) was folded in the longitudinal center.

[0085] (Comparative Example 2) As shown in Figure 6, in Comparative Example 1, a thermoelectric material-containing porous body (CNT-containing paper) was subjected to a heat press process, so that the entire thermoelectric material-containing porous body (CNT-containing paper) was made into a liquid-retentive region, and a thermoelectric conversion module was prepared with a structure in which the thermoelectric material-containing porous body (CNT-containing paper) was folded in the longitudinal center.

[0086] The folded portions of the thermoelectric material-containing porous body (CNT-containing paper) of the above-described example of the present invention, Comparative Example 1, and Comparative Example 2 were immersed in water, and the electromotive force generated between the first electrode portion connected to one end of the thermoelectric material-containing porous body (CNT-containing paper) and the second electrode portion connected to the other end of the thermoelectric material-containing porous body (CNT-containing paper) was measured.

[0087] In Comparative Example 1, the temperature of the folded portion immersed in water (liquid temperature) was 22.8°C, while the vaporization temperature at one end and the other end of the thermoelectric material-containing porous body (CNT-containing paper), which was lowered by the heat of vaporization when the liquid evaporated, was 20.6°C. Here, the electromotive force generated by the temperature difference between the bent portion and one end cancels out the electromotive force generated by the temperature difference between the bent portion and the other end, resulting in an electromotive force of 0.00V between the first electrode portion and the second electrode portion.

[0088] In Comparative Example 2, the temperature of the folded portion immersed in water (liquid temperature) was 22.8°C, while the temperature at one end and the other end of the thermoelectric material-containing porous body (CNT-containing paper) was 24.7°C, the ambient temperature. Here, the electromotive force generated by the temperature difference between the bent portion and one end cancels out the electromotive force generated by the temperature difference between the bent portion and the other end, resulting in an electromotive force of 0.01V between the first electrode portion and the second electrode portion.

[0089] In contrast, in the present invention, the other end of the thermoelectric material-containing porous body (CNT-containing paper) (the other end of the poorly absorbent region) had an ambient temperature of 24.7°C, the temperature of the folded portion immersed in water (liquid temperature) was 22.8°C, and the other end of the thermoelectric material-containing porous body (CNT-containing paper) (the other end of the easily absorbent region) had a vaporization temperature of 20.6°C, which was the temperature reduced by the heat of vaporization when the liquid evaporated. Here, the electromotive force generated by the temperature difference between the bent portion and one end is added to the electromotive force generated by the temperature difference between the bent portion and the other end, resulting in an electromotive force of 0.98V between the first electrode portion and the second electrode portion.

[0090] From the above, it has been confirmed that the present invention provides a thermoelectric conversion module capable of efficiently generating electromotive force by utilizing temperature differences. [Explanation of symbols]

[0091] 10,110,210 Thermoelectric Conversion Modules 11,111,211 1st electrode part 12,112,212 2nd electrode part 20, 120, 220 Thermoelectric materials contain porous materials. 21,121,221 Areas of easily absorbable liquids 22,122,222 Difficult-to-absorb liquid area

Claims

1. The device comprises a porous body containing a thermoelectric material, a first electrode portion connected to one end of the porous body containing the thermoelectric material, and a second electrode portion connected to the other end of the porous body containing the thermoelectric material. One end of the porous body containing the thermoelectric material is a region that easily absorbs liquid, and the other end of the porous body containing the thermoelectric material is a region that does not easily absorb liquid, and the body is bent at the connection between the easily absorbed region and the poorly absorbed region. The connecting portion is an immersion portion that is submerged in liquid, and the portion opposite to the connecting portion of the easily absorbed liquid region and the poorly absorbed liquid region is a non-immersion portion. In the aforementioned poor liquid-absorbing region, a temperature difference occurs between the immersed portion submerged in the liquid and the unimmersed portion exposed to the atmosphere. In the readily absorbent region, the temperature of the non-immersed portion decreases due to the heat of vaporization when the liquid absorbed from the immersed portion evaporates in the non-immersed portion, creating a temperature difference between the immersed portion and the non-immersed portion. A thermoelectric conversion module characterized in that an electromotive force is generated between the first electrode portion and the second electrode portion due to the temperature difference between the non-immersed portion and the immersed portion in the poorly liquid-absorbing region, and the temperature difference between the immersed portion and the non-immersed portion in the easily liquid-absorbing region.

2. The thermoelectric conversion module according to claim 1, characterized in that the thermoelectric material is a carbon nanotube.

3. The thermoelectric conversion module according to claim 1, characterized in that the thermoelectric material is an organic thermoelectric material.

4. The thermoelectric conversion module according to claim 1, characterized in that the thermoelectric material is a nanotube or nanowire made of a compound semiconductor or silicon semiconductor.

5. The thermoelectric conversion module according to claim 1, characterized in that the porous body is a composite fiber containing one or more of the following: paper, yarn, nonwoven fabric, or cloth.

6. The thermoelectric conversion module according to claim 1, characterized in that the liquid is a volatile liquid that can evaporate at room temperature.

7. The thermoelectric material-containing porous body comprises a p-type thermoelectric material-containing porous body containing a p-type thermoelectric material and an n-type thermoelectric material-containing porous body containing an n-type thermoelectric material, wherein the non-immersed portion of the poorly liquid-absorbing region of the p-type thermoelectric material-containing porous body and the non-immersed portion of the poorly liquid-absorbing region of the n-type thermoelectric material-containing porous body, or the non-immersed portion of the easily liquid-absorbing region of the p-type thermoelectric material-containing porous body and the non-immersed portion of the easily liquid-absorbing region of the n-type thermoelectric material-containing porous body are electrically connected, as described in claim 1.

8. The thermoelectric conversion module according to claim 1, wherein the thermoelectric material-containing porous body comprises a plurality of the thermoelectric material-containing porous bodies, each of which is either a p-type thermoelectric material-containing porous body containing a p-type thermoelectric material or an n-type thermoelectric material-containing porous body containing an n-type thermoelectric material, and the non-immersed portion of the poorly liquid-absorbing region of the thermoelectric material-containing porous body and the non-immersed portion of the easily liquid-absorbing region of the thermoelectric material-containing porous body are electrically connected by a conductive porous body made of a porous body containing a conductor.

9. A thermoelectric power generation device having a thermoelectric conversion module according to any one of claims 1 to 8, characterized in that it generates electricity based on the temperature difference between the non-immersed portion and the immersed portion in the poorly liquid-absorbing region and the temperature difference between the immersed portion and the non-immersed portion in the easily liquid-absorbing region.

10. A liquid sensor having a thermoelectric conversion module according to any one of claims 1 to 8, characterized in that it detects the presence or absence of liquid by detecting an electrical signal generated by the temperature difference between the non-immersed portion and the immersed portion in the non-liquid-absorbent region and the temperature difference between the immersed portion and the non-immersed portion in the easily absorbed region when the liquid is immersed in the immersed portion.

Images