JP2018200248A - Gas sensor and manufacturing method thereof - Google Patents

Abstract

To provide a gas sensor capable of being manufactured at low cost, and excellent in reliability.SOLUTION: A gas sensor for detecting the concentration of a specific component in gas, comprises: a support 1; a pair of electrodes 2a, 2b provided on one surface of the support 1, and to which an electrical signal is applied; a sensitive substance 3a bridged between the pair of electrodes 2a, 2b, and whose electric characteristics change by reaction with the specific component; and a coating member 6 provided on the one surface side of the support 1, and forming a flow passage. Each of the electrodes 2a, 2b is coated with a carbon continuous film with a thickness of 1 μm or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gas sensor and a manufacturing method thereof, and more particularly to an improved gas sensing technique.

  Currently, medical care is highly developed, and its condition can be grasped by analyzing body fluids such as blood, saliva, urine, and exhaled breath. For example, research has been conducted on determining the presence or absence of dental caries by measuring the pH of saliva and diagnosing diabetes by measuring the blood sugar level of tears. In addition, by examining nitric oxide and hydrogen sulfide in exhaled breath, it is possible to grasp the state of inflammation, infection, etc. in the trachea and mouth. In general, these tests are performed in medical institutions. In a medical institution, body fluid and breath of a subject are collected, and the collected specimen is measured and analyzed.

  On the other hand, an apparatus has been developed for a subject to collect body fluid and breath at home and to measure and analyze the collected sample. This not only enables rapid examination and analysis, but can also be used as a means for reducing medical costs, as will be described below.

  In general, after being aware of a change in physical condition, see a medical institution. However, at that stage, the medical condition has already progressed, and advanced medical treatment and administration of expensive drugs are performed, and as a result, the medical cost burden may increase.

  If a change in physical condition can be detected at an early stage, it may be cured by reviewing lifestyle habits. For this reason, regular checkups are carried out as preventive treatments organized by the Health Insurance Association.

  However, since regular screening is generally about once to twice a year, there is a blank period between screenings, and diseases that develop during this period cannot be recognized.

  If the subject himself / herself collects bodily fluids and exhaled breaths at home and uses a device that can measure and analyze the collected specimens, the test frequency can be increased. Therefore, it becomes possible to detect a change in physical condition before being aware of it. Therefore, opportunities for advanced medical care and administration of expensive drugs are reduced, and medical costs can be reduced.

  There are various biosensing techniques, but electrochemical techniques are widely used because trace components can be detected with high sensitivity. In the electrochemical technique, biological information that is a chemical characteristic can be detected as an electrical signal, and thus there is an advantage that it is easy to process and analyze a signal obtained using a semiconductor device or the like. For this reason, development of new electrochemical sensing devices and sensing methods using the same has been actively carried out worldwide.

For example, Patent Document 1 describes an electrochemical sensor for introducing an ionomer to the electrode surface and measuring the concentration of nitric oxide in exhaled breath. Patent Document 2 describes a cobalt oxide-sensitive material carrying a noble metal. An electrochemical sensor is described that analyzes the carbon monoxide concentration by measuring the resistance of the layer.

  Patent Document 3 describes an electrochemical sensor that analyzes the concentration of mercaptan or hydrogen sulfide by measuring the resistance value of a sensitive layer containing titanium oxide, cerium oxide, and vanadium oxide.

  In these technologies, gases generated from living bodies such as sweat and breath, and gases in the environment are collected, and various chemical substances contained in the gases are adsorbed to the sensitive substances that cover the electrodes, so Measure the change in the current value, resistance value, and capacitance value flowing through the. Since these changes are very small, it is important to keep the electrode stability and the distance between the electrodes constant.

  As such a material, carbon is used in addition to a noble metal. This is because carbon is an electrochemically inactive material.

  For example, Patent Document 4 describes using carbon as an electrode material for an electrochemical sensor. The carbon electrode described here was provided so as to cover the insulating substrate, the conductive layer provided on the insulating substrate, the first carbon layer provided on the conductive layer, and the first carbon layer. A second carbon layer. The first carbon layer includes carbon having an SP2 bond and an SP3 bond and having an amorphous structure. The second carbon layer contains carbon having an SP2 bond. Specifically, the first carbon layer is a carbon layer made of diamond-like carbon or amorphous carbon having an amorphous structure, formed by vapor phase growth.

Japanese Patent No. 6076749 Japanese Patent Laying-Open No. 2015-040753 JP-A-2006-125916 Japanese Patent No. 5120453

  The problems found by the inventors regarding the prior art when inventing the present invention are described below.

  As shown in Patent Documents 1 to 4, a biosensor has been invented that electrochemically measures and analyzes components of gas and body fluid obtained from a living body to obtain a numerical value as a biomarker.

  About such an existing biosensor, it is necessary to improve reliability. Moreover, in order to widely disseminate this, it is desired to reduce costs and improve productivity in manufacturing.

  One of the most important points to realize these is that the electrode, which is an important element when performing electrochemical measurements, is actually used from various viewpoints including cost, etc. in terms of form, material and manufacturing method. Whether it can be adapted to the manufacture of

  About the form of an electrode, it is necessary for a measurement electrode to be able to be made into various shapes according to a use. For example, the measurement electrode is not a flat surface but a curved surface or a three-dimensional shape, thereby improving compatibility with various apparatuses.

  Generally, noble metals such as gold and platinum are selected as the electrochemically stable conductive material. Since these substances are very expensive, they are formed as a thin film on a substrate and formed into an electrode shape by patterning. However, in order to avoid pinholes, it is necessary to ensure a certain film thickness, so that even a thin film has a high cost.

  On the other hand, in Patent Document 1, since glass or silicon ceramic is used for the base and a dry etching process is used for processing the base or forming electrodes, there are problems in terms of manufacturing method and cost.

  In Patent Documents 2 and 3, a baked sensitive material is used, which is convenient to carry. However, since the electrode is produced by baking a noble metal paste, the foreign matter contained in the paste is increased by the electrode. There is a problem that the shape of the sensor is limited because there is a concern about the change in electrochemical characteristics and pinholes that occur due to remaining inside, and the difficulty in printing a paste on a three-dimensional substrate.

  In Patent Document 4, two types of carbon layers having different structures are provided. However, the two types of carbon layers have different manufacturing methods and have problems in manufacturing cost and manufacturing lead time.

  Accordingly, an object of the present invention is to provide a gas sensor that can be manufactured at low cost and has excellent reliability, and a method for manufacturing the gas sensor.

  According to the first aspect of the present invention, the electrode has two or more electrodes, the surface of the electrode is made of a carbon film, and the carbon film is a continuous film having a thickness of 1 micrometer or more. The electrodes are cross-linked by a sensitive substance, and equipped with a gas concentration detector that reads the electrical signal flowing through the sensitive substance or changes in the characteristics of the sensitive substance, and the gas sample flows along the tube-shaped flow path. A gas sensor is provided in which a sample is efficiently supplied to a sensitive material.

  According to the second aspect of the present invention, the method includes a step of obtaining an electrode having a continuous film made of carbon and having a thickness of 1 micrometer or more by a plating method, and a step of forming a tube shape serving as a flow path for a gas sample. A method for manufacturing a gas sensor is provided.

  According to the present invention, a gas sensor that can be manufactured at low cost and has excellent reliability and a method for manufacturing the gas sensor are provided.

1 is a perspective view schematically showing a gas sensor according to a first embodiment of the present invention. The perspective view which shows the manufacturing process of the gas sensor roughly. 1 is a plan view schematically showing a gas sensor according to a first embodiment of the present invention. The perspective view which shows schematically the gas sensor which concerns on 2nd Embodiment of this invention. The top view which shows the same gas sensor roughly. The perspective view which shows roughly the manufacturing process of the gas sensor which concerns on 3rd Embodiment of this invention. The perspective view which shows schematically the manufacturing process of the gas sensor which concerns on 4th Embodiment of this invention. The top view which shows roughly the gas sensor which concerns on 5th Embodiment of this invention. The top view which shows roughly the gas sensor which concerns on 6th Embodiment of this invention. The perspective view which shows schematically the gas sensor which concerns on 7th Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings. In addition, in order to abbreviate | omit duplicate description, the same referential mark is attached | subjected to the component which exhibits the same or similar function in an accompanying drawing. In addition, the dimensions of each part shown in the description are examples, and can be appropriately changed according to various conditions such as the purpose of use and the type of gas used.
<First Embodiment>
FIG. 1 is a perspective view schematically showing a gas sensor 8 according to the first embodiment of the present invention, and FIG. 2 is a perspective view schematically showing a manufacturing process of the gas sensor 8. As shown in FIG. The gas sensor 8 is an electrochemical sensor. The gas sensor 8 uses, for example, a breath derived from a living body, sputum, body odor and the like as a gas sample.

  As shown in FIG. 1, the gas sensor 8 includes a flat plate-like support body 1 and a cover member 6 disposed to face the upper surface side of the support body 1. The cover member 6 is open at both ends in the longitudinal direction of the support 1, and the support 1 and the cover member 6 form a rectangular tube. As indicated by an arrow 7, a flow path through which a gas sample to be inspected flows from the near side to the far side is formed by this rectangular cylinder. As the material (material) of the support 1, for example, glass such as quartz, Nippon Electric Glass Neoceram, Corning Vycor, sapphire, silicon nitride, silicon carbide, plastic, or the like can be used.

  On the support 1, a pair of electrodes 2a and 2b are arranged such that the longitudinal direction thereof is along the flow direction. The pair of electrodes 2a and 2b is set at a constant interval.

  The sensitive substance 3a is cross-linked between the electrodes 2a and 2b. The electrodes 2 a and 2 b are covered with a carbon film 4. The carbon film 4 is a protective layer made of a continuous film having a thickness of 1 μm, and pinholes are hardly generated. The electrodes 2a and 2b are connected to an external measuring instrument (not shown).

  Such a gas sensor 8 is manufactured by the following process. That is, as shown in FIG. 2A, two stainless steel bases 5 having a width of 1 mm, a length of 40 mm, and a thickness of 300 μm are prepared and held so as to be parallel to each other with an interval of 500 μm. And this is fixed to the support body 1 of width 10mm, length 50mm, and thickness 5mm.

  Next, as shown in FIG. 2B, the base 5 fixed to the support 1 was coated with a carbon film 4 with a thickness of 1 μm by plating to form an electrode 2a and an electrode 2b. Although not shown, a power supply line is provided on each base (metal conductor) 5 and electroplating is performed. Further, as shown in FIG. 2C, a tin oxide paste as a sensitive material 3a was applied to the surface and sintered so as to crosslink the electrodes 2a and 2b.

  As shown in FIG. 1, a gas sensor 8 was obtained by forming a tube shape by covering the support 1 with a covering member 6 so that the electrodes 2a and 2b were inside. The manufacturing method of the gas sensor is not limited to the above, and after the carbon film 4 is formed on the base 5 by plating, the base 5 covered with the carbon film 4 may be fixed to the support 1.

  The gas sensor 8 according to this embodiment configured as described above is used as shown in FIG. The gas sensor 8 has a tube shape with both ends open, and as shown in FIG. 3A, the gas sensor 8 has a shape that can serve as a flow path for a gas sample from the near side to the far side. Note that the gas sample can pass from one port (front side) of the gas sensor 8 to the other port (back side) in the direction indicated by the arrow 7.

  As shown in FIG. 3 (B), when the subject holds one mouth of the tube of the gas sensor 8 and blows exhaled air into the tube, the tube shape becomes the flow channel of exhaled air, and the expiratory material 3a Can be supplied to. At this time, if an electrical signal is applied to the sensitive substance 3a, the electrical characteristics when a specific gas is not present are different from the electrical characteristics when a specific gas is present. By comparing the electrical characteristics, the concentration of the gas can be measured.

  In addition, even when the electrode of the gas sensor 8 is enlarged, exhaled gas can be efficiently supplied to the sensitive substance 3a through the flow path, and an improvement in measurement accuracy can be expected.

  The gas sensor 8 according to the present embodiment configured as described above can solve one or more of the problems described above. The gas sensor 8 according to the present embodiment employs a structure including that the surface layers of the electrodes 2 a and 2 b are the carbon film 4. The carbon film 4 is a continuous film having a thickness of 1 μm or more. Carbon is electrochemically inert. Therefore, even when the carbon film is brought into contact with a living body, a liquid, or a gas, it is difficult to cause deterioration.

  Moreover, the carbon film 4 is a protective layer made of a continuous film as described above. That is, this protective layer is not a porous film or a film composed of carbon particles, but a dense film, unlike those formed using carbon paste. And since this carbon film 4 has sufficient thickness, it is hard to produce a pinhole.

  In addition, as described above, the carbon film 4 is not a porous film or a film composed of carbon particles, but a continuous film. Therefore, this protective layer has high electrical conductivity. Therefore, this gas sensor 8 is excellent in reliability and can be measured with high accuracy. Carbon is a cheaper material than precious metals, and its price fluctuation is small. Therefore, this gas sensor can be manufactured at a relatively low cost.

  Therefore, according to the gas sensor 8 which concerns on this embodiment, it becomes possible to improve reliability at low cost.

  Furthermore, it is preferable that the carbon film 4 covers at least the entire region where the gas sample can come into contact with the surface. The carbon film 4 is formed by, for example, a plating method. For example, it is possible to use a carbon plating technique that is implemented by I'MCEP Co., Ltd. using molten salt electrolysis. According to the plating method, a thick protective layer can be formed. For example, a protective layer having a thickness of 0.1 to 20 μm can be formed, and preferably the thickness of the protective layer is 1 to 5 μm.

  Further, according to the plating method, the carbon film 4 having a uniform thickness can be formed even when the substrate has a complicated shape. For example, when the substrate 5 has a curved or bent shape, the carbon film 4 is formed so as to cover at least a region corresponding to a curved or bent portion of the metal surface of the substrate 5. Can do.

  Further, according to the plating method, the protective layer can be formed at a relatively low cost and with high productivity.

  As another method for forming the carbon film 4 on the surface of the substrate 5 using an electrochemical reaction, conductive carbon particles are contained in an electrolytic solution containing a metal to be deposited so that the substrate 5 becomes a cathode. There is a method of forming the carbon film 4 by causing an electrochemical reaction. As the carbon particles, for example, those containing a graphite structure and composed of a mixture of sp2 structure and sp3 structure are used.

  As a metal to be deposited, for example, in addition to noble metals such as gold, platinum, silver, rhodium and ruthenium, iron, nickel, cobalt, copper, chromium, zinc or alloys thereof can be used in an electrolytic plating solution made of an aqueous solution. A thing can be selected suitably. Alternatively, when a non-aqueous dimethyl sulfone bath is used, aluminum can be used as the metal to be deposited.

  Prior to coating the carbon film 4 by plating, the electrodes 2a and 2b are formed in advance so that the substrate 5 conforms to the sensor shape. Examples of the formation include bending the base 5 and cutting it into a necessary shape, and press working or lathe processing can be used for these processes. As an example of the processed shape, a dumbbell shape, a spring shape, a donut shape, or the like can be selected. The power supply line to electroplating may be sealed with resin when used for input / output of electrical signals for sensing.

  The sensitive material 3a is used for the measurement. As the sensitive substance 3a, generally used oxide semiconductors, organic semiconductors, and compound semiconductors can be used. Examples of oxide semiconductors include tin oxide, zinc oxide, and indium oxide. May be used alone or in combination. Moreover, it will not be limited if it shows reaction with respect to a specific chemical substance.

  The sensitive substance 3a needs to electrically connect the electrode 2a and the electrode 2b. For this reason, the sensitive substance 3a needs to be cross-linked so as to electrically connect the electrodes 2a and 2b.

  As the covering shape of the sensitive substance 3a, it is sufficient that at least two electrodes 2a and 2b are electrically connected. Therefore, the covering shape may be a shape covering the entire electrode 2a and electrode 2b. For example, only the side walls of the electrode 2a and the electrode 2b may be in contact with the sensitive material 3a.

  For the above reasons, the sensitive material 3a is preferably in the form of a gel, a paste, or a sheet in order to achieve a continuous bridge between the electrodes 2a and 2b with the sensitive material 3a. If it is a gel or paste, it can be used by applying it sufficiently thickly by printing or spraying, and firing and drying as necessary. In addition, if it is a sheet, it can be processed in advance to the required shape, and can be used by being affixed on the electrode 2a and electrode 2b. It is also possible to cut and use, and in the latter case, there is a merit that alignment is not required when the sensitive material sheet is bonded.

  Assuming that the mouth of the tube of the gas sensor 8 is added to the mouth, a circular shape having a diameter of 0.5 to 5 cm or a square having a side length of 0.5 to 5 cm is desirable, and the length of the tube is 1-20 cm is desirable from the operativity. The thickness of the tube material is preferably 0.1 to 1 cm.

  Moreover, even if the electrode area of the gas sensor 8 is increased, the gas sensor 8 can be efficiently supplied to the sensitive substance 3a even if the electrode area of the gas sensor 8 is increased, and the accuracy of the gas sensor 8 is expected to be improved.

  As described above, the chemical substance is detected by measuring the electrical characteristics between the electrode 2a and the electrode 2b in contact with the sensitive substance 3a and capturing the change. The electrical characteristics include voltage, current, inductance, capacity, impedance, and the like. Further, as an electric signal applied at the time of measurement, direct current, alternating current, arbitrary sine wave, rectangular wave, impulse waveform, or the like can be freely selected.

  It is necessary to reduce the noise as much as possible when measuring the electric signal. For that purpose, it is desirable to make the distance between the electrodes 2a and 2b as small as possible in two or more electrodes.

  By reducing the distance between each electrode 2a and electrode 2b, the resistance value of the sensitive substance 3a itself becomes small, and it becomes easy to detect a change in electrical characteristics even with a very small amount of chemical substance. In order to realize this, it is desired that the distance between the electrodes is 1 mm or less, preferably 0.5 mm or less. When the distance between the electrodes exceeds 1 mm, there are disadvantages in terms of a decrease in detection accuracy due to an increase in resistance value, a material cost, baking / drying time, and the like as compared with a case where the distance is less than 1 mm.

  The substrate 5 may have a planar shape, a curved shape, a combination of planar shapes, a combination of curved shapes, a combination of a planar shape and a curved shape, and a flexible It may be a simple film.

By disposing the electrode 2a and the electrode 2b along the longitudinal direction of the support 1, the opposing areas of the electrode 2a and the electrode 2b are increased, and the amount of the gas sample that reacts with the sensitive substance 3a can be increased. Accuracy can be improved.
Second Embodiment
FIG. 4 is a perspective view showing a gas sensor 10 according to the second embodiment of the present invention, and FIG. 5 is a cross-sectional view of the gas sensor 10. As shown in FIG. 4, a blower 9 is installed at the inlet of the tube so that the gas sample moves along the flow path of the gas sensor 10, and the surrounding gas sample is efficiently supplied to the sensitive substance 3a. The gas sensor 10 has a tube shape, and when viewed from one tube-shaped mouth as shown in FIG. 5, both ends of the tube shape are open and can be a flow path for a gas sample.

  The gas sensor 10 is provided with a covering member 6 so that the gas sample moves along the flow path. The surrounding gas sample can be moved in the direction of the arrow 7 by the blower 9, and the gas sample is sensitive. The substance 3a can be efficiently supplied, and improvement in measurement accuracy can be expected.

  Further, even when the electrode of the gas sensor 10 is enlarged, the surrounding gas sample can be efficiently supplied to the sensitive substance 3a through the flow path, and an improvement in measurement accuracy can be expected.

  In the case of the gas sensor 10 provided with the blower 9, the outer size of the mouth of the tube is preferably a circle having a diameter of 1 to 10 cm, or a square having a side length of 1 to 10 cm, and the length of the tube is preferably 2 to 20 cm. The thickness of the tube material is preferably 0.1 to 2 cm.

For example, when the body odor is used as a gas sample, the body odor can be efficiently supplied to the sensitive substance 3a by installing the blower 9 in the flow direction of the tube-shaped gas sensor 10 in a body odor atmosphere.
<Third Embodiment>
FIG. 6 is a perspective view showing a manufacturing process of the gas sensor 8 according to the third embodiment of the present invention. As shown in FIG. 6A, four stainless steel bases 5 having a width of 1 mm, a length of 40 mm, and a thickness of 300 μm are prepared, and held at intervals of 500 μm so as to be parallel to each other. This was fixed to a support 1 having a width of 10 mm, a length of 50 mm, and a thickness of 5 mm.

  Next, as shown in FIG. 6B, the base 5 fixed to the support 1 was coated with a carbon film 4 with a thickness of 1 μm by plating to form electrodes 2a, 2b, 2c and 2d. Although not shown, a power supply line was provided on each base 5 and electroplating was performed.

  Further, as shown in FIG. 6C, the sensitive material 3a and the sensitive material 3b were respectively applied to the surfaces and sintered so as to bridge between the electrodes 2a and 2b and between the electrodes 2c and 2d. . Similarly to the first embodiment, a tubular member was formed by covering the support 1 with the covering member 6 so that the electrode of FIG. Further, as in the second embodiment, the blower 9 is installed so that the gas sample moves along the flow path of the gas sensor, and the surrounding gas sample is efficiently supplied to the sensitive substance 3a and the sensitive substance 3b. A gas sensor was obtained.

When the sensitive substance 3a and the sensitive substance 3b are different substances, two components can be measured simultaneously. Further, when the sensitive substance 3a and the sensitive substance 3b are the same substance, the measurement accuracy can be improved.
<Fourth embodiment>
FIG. 7 is a perspective view showing a manufacturing process of the gas sensor 8 according to the fourth embodiment of the present invention. As shown in FIG. 7A, four stainless steel bases 5 having a width of 1 mm, a length of 20 mm, and a thickness of 300 μm are prepared, the long side is spaced by 500 μm, and the short is spaced by 3 mm. These were held parallel to each other, and fixed to a support 1 having a width of 10 mm, a length of 50 mm, and a thickness of 5 mm.

  Next, as shown in FIG. 7B, the substrate 5 fixed to the support 1 was coated with a carbon film 4 with a thickness of 1 μm by plating to form electrodes 2a, 2b, 2e and 2f. Although not shown, a power supply line was provided on each base 5 and electroplating was performed.

  Further, as shown in FIG. 7C, the sensitive material 3a and the sensitive material 3c were applied and sintered on the surface so as to bridge between the electrodes 2a and 2b and the electrodes 2e and 2f, respectively. Similarly to the first embodiment, a tubular member was formed by covering the support 1 with the covering member 6 so that the electrode of FIG. Further, similarly to the second embodiment, the blower 9 is installed so that the gas sample moves along the flow path of the gas sensor, and the surrounding gas sample is efficiently supplied to the sensitive substance 3a and the sensitive substance 3c. A gas sensor was obtained.

When the sensitive substance 3a and the sensitive substance 3c are different substances, two components can be measured simultaneously. Further, when the sensitive substance 3a and the sensitive substance 3c are the same substance, the measurement accuracy can be improved.
<Fifth Embodiment>
FIG. 8 is a sectional view schematically showing a gas sensor 12 according to the fifth embodiment of the present invention. In the gas sensor 12, three sets of the support 1 described above were used, and the long sides of each of the supports 1 were connected via the connection portion 11 to form a tube shape having a triangular cross section serving as a gas sample flow path. Each electrode 2a, 2b, electrode 2g, 2h, electrode 2i, 2j is located inside the tube shape. The connecting portion 11 is rubber, adhesive, or the like.

  The gas sensor 12 includes three sets of electrodes 2a and 2b, electrodes 2g and 2h, electrodes 2i and 2j, and sensitive materials 3a, 3d, and 3e that are arranged in a bridge. When the sensitive materials 3a, 3d, and 3e are different materials, three types of components can be measured simultaneously. Further, when two to three sensitive substances are the same, the measurement accuracy can be improved.

Thus, the gas sensor 12 which is an electrochemical gas sensor can have a plurality of sets of electrodes and sensitive substances. By using a plurality of different sensitive substances, it is possible to measure a plurality of types of chemical substances at a time. In addition, by using the same type of sensitive substance for a plurality of sets of electrodes, the measurement accuracy can be increased.
<Sixth Embodiment>
FIG. 9 is a sectional view schematically showing a gas sensor according to the sixth embodiment of the present invention. The gas sensor 14 used three sets of the above-described supports 1 and connected the long sides of each of the supports 1 via the connecting portion 11 to form a tube shape having a triangular cross section serving as a gas sample flow path. The electrodes 2a and 2b and the electrodes 2k and 2l are located inside the tube shape. The connecting portion 11 is rubber, adhesive, or the like.

  The gas sensor 14 includes two sets of electrodes 2a and 2b, electrodes 2k and 2l, and sensitive materials 3a and 3f arranged in a cross-linked manner. When the sensitive materials 3a and 3f are different materials, two kinds of components can be measured simultaneously. Moreover, when two sensitive substances are the same, measurement accuracy can be improved.

Thus, the gas sensor 12 which is an electrochemical gas sensor can have a plurality of sets of electrodes and sensitive substances. By using a plurality of different sensitive substances, it is possible to measure a plurality of types of chemical substances at a time. In addition, by using the same type of sensitive substance for a plurality of sets of electrodes, the measurement accuracy can be increased.
<Seventh embodiment>
FIG. 10 is a perspective view schematically showing a gas sensor 8 according to the seventh embodiment of the present invention. The support 1 of the gas sensor 8 includes a power supply unit 16 that supplies power to each unit, an electrical signal generation unit 17 that generates electrical signals, an electrical signal detection unit 18 that detects electrical signals, a recording unit 19 that records measurement results, A measurement result display unit 15 for displaying the measurement results, a wireless output unit 20 for outputting the measurement results wirelessly, and a wired output unit 21 for outputting the measurement results by wire are mounted.

  According to the gas sensor 8 configured as described above, the power sensor function, the electric signal generation function, the measurement result detection function, and the measurement result for performing the application and measurement of the electric signal have the same function as the gas sensor 8 described above. And a function for displaying the measurement result are necessary. These functions may be built in the gas sensor 8 or may be an external device. Moreover, you may provide the function to output a measurement result by a wire, and the function to output a measurement result by radio | wireless.

  In addition, this invention is not limited to the said embodiment, In the implementation stage, it can change variously in the range which does not deviate from the summary. Further, the embodiments may be implemented in combination as appropriate, and in that case, the combined effect can be obtained. Furthermore, the present invention includes various inventions, and various inventions can be extracted by combinations selected from a plurality of disclosed constituent elements. For example, even if several constituent requirements are deleted from all the constituent requirements shown in the embodiment, if the problem can be solved and an effect can be obtained, the configuration from which the constituent requirements are deleted can be extracted as an invention.

  DESCRIPTION OF SYMBOLS 1 ... Support body, 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k, 2l ... Electrode, 3a, 3b, 3c, 3d, 3e, 3f ... Sensitive substance, 4 ... Carbon film DESCRIPTION OF SYMBOLS 5 ... Base | substrate, 6 ... Cover member, 7 ... Moving direction of gas sample, 8 ... Gas sensor, 9 ... Blower, 10 ... Gas sensor, 11 ... Connection part, 12 ... Gas sensor, 14 ... Gas sensor, 15 ... Measurement result display part, DESCRIPTION OF SYMBOLS 16 ... Power supply part, 17 ... Electric signal generation part, 18 ... Electric signal detection part, 19 ... Recording part, 20 ... Wireless output part, 21 ... Wired output part

Claims (14)

A gas sensor for detecting the concentration of a specific component in a gas,
A support;
A pair of electrodes provided on one surface of the support and applied with an electrical signal;
A sensitive substance that is cross-linked between the pair of electrodes and changes electrical characteristics by reacting with the specific component;
Provided on the upper surface of the one surface of the support, and has a covering member that forms a flow path;
Each of the electrodes is a gas sensor covered with a continuous carbon film having a thickness of 1 μm or more. A gas sensor for detecting the concentration of a specific component in a gas,
Three or more supports that are arranged in a tubular shape with their surfaces facing each other to form a flow path;
A pair of electrodes provided on the inner surface of at least one of the supports, to which an electrical signal is applied;
A sensitive substance that is cross-linked between the pair of electrodes and changes electrical characteristics by reacting with the specific component;
Each of the electrodes is a gas sensor covered with a continuous carbon film having a thickness of 1 μm or more.   The gas sensor according to claim 2, further comprising a connecting portion for sealing between the supports.   The gas sensor according to claim 1, wherein a blower is provided in one opening of the flow path.   The gas sensor according to claim 1 or 2, comprising two or more pairs of the pair of electrodes.   The gas sensor according to claim 1 or 2, wherein the pair of electrodes are arranged along a longitudinal direction of the support.   The gas sensor according to claim 1 or 2, wherein an opening of the flow path is formed with an exhalation air inlet.   The gas sensor according to claim 1, wherein the sensitive substance includes at least one of an oxide semiconductor, an organic semiconductor, and a compound semiconductor. An electric signal generator for inputting an electric signal to the pair of electrodes;
The gas sensor according to claim 1, further comprising an electric signal detector that detects an electric signal from the pair of electrodes.   The gas sensor according to claim 9, further comprising a recording unit that records a measurement result detected by the electrical signal detection unit or a display unit that displays the measurement result.   The gas sensor according to claim 9, further comprising at least one of a wireless output unit and a wired output unit that outputs measurement results detected by the electrical signal detection unit to the outside. Bonding the metal conductor onto the support;
Coating the metal conductor with carbon by electroplating;
A method of manufacturing a gas sensor comprising a step of forming a flow path by covering the support with a cover member with the metal conductor facing inside. Coating a metal conductor with carbon by electroplating;
Bonding the metal conductor onto a support;
A method of manufacturing a gas sensor comprising a step of forming a flow path by covering the support with a cover member with the metal conductor facing inside. Adhering a metal conductor on at least one of the three or more supports;
Coating the metal conductor with carbon by electroplating;
A method of manufacturing a gas sensor comprising a step of forming a channel by forming the support in a tubular shape with the metal conductor inside.