Gas sensor, sensor device, and method for detecting acetone and ethanol

Abstract

To provide a technique capable of improving gas selectivity.SOLUTION: A gas sensor includes an adsorption unit configured to adsorb and concentrate a gas, a heater configured to heat the adsorption unit to desorb the gas from the adsorption unit, and a detection unit configured to detect the gas desorbed from the adsorption unit, wherein the adsorption unit includes an aluminosilicate zeolite having a Si / Al ratio of 1 or more and 2.75 or less, and acetone is detectable as the gas.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to gas sensors. [Background technology]

[0002] There has been a demand for technology capable of measuring low-concentration gases. For example, Patent Document 1 proposes a gas sensor having a heater layer and a gas detection unit that is heated by the heater layer and detects a gas to be measured, the gas detection unit having a gas sensing layer, a diffusion layer that covers the surface of the gas sensing layer, and an adsorption layer that covers the surface of the diffusion layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-20883 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology described in Patent Document 1 leaves room for improvement in terms of gas selectivity, and therefore there is a demand for a technology that can improve gas selectivity. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to one aspect of the present disclosure, there is provided a gas sensor. The gas sensor includes an adsorption unit that adsorbs and concentrates a gas, a heater that heats the adsorption unit to desorb the gas from the adsorption unit, and a detection unit that detects the gas desorbed from the adsorption unit. The adsorption unit contains an aluminosilicate zeolite having a Si / Al ratio of 1 to 2.75, and is capable of detecting acetone as the gas. According to this aspect of the gas sensor, because the adsorption unit contains an aluminosilicate zeolite having a Si / Al ratio of 2.75 or less, the desorption times of multiple gases adsorbed in the adsorption unit can be shifted depending on the heating of the adsorption unit. As a result, multiple gases can be separated and detected, improving gas selectivity.

[0007] (2) In the gas sensor described in (1) above, the pore diameter of the aluminosilicate zeolite may be 0.6 nm or more, and the gas may be acetone. According to this gas sensor, the pore diameter of the aluminosilicate zeolite is 0.6 nm or more, so that the selectivity for acetone can be further improved.

[0008] (3) In the gas sensor described in (1) or (2), the aluminosilicate zeolite may have a skeleton of FAU. According to this gas sensor, the aluminosilicate zeolite has a skeleton of FAU, which can further improve gas selectivity.

[0009] (4) According to another aspect of the present disclosure, a sensor device is provided. The sensor device includes the gas sensor according to any one of (1) to (3) above and an adjustment unit that adjusts the heating rate of the heater. According to this aspect of the sensor device, the adjustment unit that adjusts the heating rate of the heater makes it possible to easily shift the desorption timing of multiple gases concentrated in the adsorption unit by adjusting the heating rate. As a result, multiple gases can be easily separated and detected, thereby further improving gas selectivity.

[0010] (5) According to another aspect of the present disclosure, there is provided a method for detecting acetone and ethanol. This method is a method for detecting acetone and ethanol using the gas sensor described in any one of (1) to (3) above, characterized in that the heater is gradually heated to stagger the desorption times of acetone and ethanol concentrated in the adsorption section, thereby separately detecting acetone and ethanol. According to the method of this aspect, acetone and ethanol can be separately detected.

[0011] The present disclosure can be realized in various forms, such as an acetone sensor, a method for manufacturing a gas sensor, a method for manufacturing a sensor device, and a method for monitoring gas using a gas sensor. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view schematically showing the general configuration of a gas sensor. [Figure 2] FIG. 1 is a perspective view schematically illustrating a general configuration of a gas sensor. [Figure 3] FIG. 2 is a block diagram showing a schematic configuration of a sensor device. [Figure 4] 1 is a cross-sectional view schematically showing the general configuration of a gas sensor according to a first modified example. [Figure 5] FIG. 10 is a cross-sectional view schematically showing the general configuration of a gas sensor according to Modification 2. [Figure 6] FIG. 10 is a cross-sectional view schematically showing the general configuration of a gas sensor according to a third modification. [Figure 7] FIG. 1 is an explanatory diagram showing the desorption spectrum of acetone in Comparative Example 1. [Figure 8] FIG. 2 is an explanatory diagram showing the desorption spectrum of acetone in Example 1. [Figure 9] FIG. 10 is an explanatory diagram showing an example of an MS spectrum in Comparative Example 2. [Figure 10] FIG. 1 is an explanatory diagram showing the desorption spectrum of ethanol in Comparative Example 1. [Figure 11]FIG. 2 is an explanatory diagram showing the desorption spectrum of ethanol in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0013] A. Embodiment FIG. 1 is a cross-sectional view schematically illustrating the general configuration of a gas sensor 100 according to an embodiment of the present disclosure. FIG. 2 is a perspective view schematically illustrating the general configuration of the gas sensor 100. For convenience of illustration, FIGS. 1 and 2 only show the configuration of the main parts of the gas sensor 100. The gas sensor 100 according to this embodiment is a semiconductor sensor. The gas sensor 100 according to this embodiment is formed by MEMS. The gas sensor 100 includes an adsorption unit 10, a detection unit 20, and a heater 30. The gas sensor 100 according to this embodiment also includes a substrate 40 and a pair of electrodes 50. The gas sensor 100 according to this embodiment includes a substrate 40 having a heater 30 embedded therein, on which the pair of electrodes 50, the detection unit 20, and the adsorption unit 10 are layered in this order.

[0014] As shown in FIG. 1 , the base material 40 of this embodiment includes a substrate 41 and an insulating layer 42. The material of the substrate 41 is not particularly limited, but examples thereof include semiconductors such as silicon, silicon carbide, and gallium nitride. The substrate 41 has a through-hole 43 formed therein, penetrating from the upper surface to the lower surface of the substrate 41. The insulating layer 42 is formed on the upper surface of the substrate 41 so as to close the through-hole 43. With this configuration, the base material 40 of this embodiment has a diaphragm-type structure, and a decrease in thermal efficiency is suppressed. The material of the insulating layer 42 is not particularly limited, but examples thereof include insulators such as silicon oxide and silicon nitride. In this embodiment, the heater 30 is embedded in a region of the insulating layer 42 corresponding to the through-hole 43.

[0015] The heater 30 heats the adsorption unit 10. This causes the gas adsorbed and concentrated in the adsorption unit 10 to be desorbed, as described below. The heater 30 of this embodiment is configured to be able to heat the detection unit 20 in addition to the adsorption unit 10. In other words, the heater 30 has the dual function of heating the adsorption unit 10 and the detection unit 20. By heating the detection unit 20, the heater 30 changes the resistance value of the detection unit 20, as described below.

[0016] The heater 30 in this embodiment is a micro-heater. In this embodiment, the heater 30 is formed in a spiral shape that is generally rectangular when viewed from above and is embedded inside the insulating layer 42. The heater 30 is not limited to a spiral shape, and may be formed in any shape, such as a wave shape or a serpentine shape. In this embodiment, the heater 30 is formed to include a heating element made of platinum. However, the heater 30 is not limited to platinum, and may include a heating element made of a nickel-chromium alloy, a platinum alloy, a nickel alloy, a chromium alloy, or the like. The heater 30 is electrically connected to contact pads (not shown) and receives power from an external circuit via the contact pads.

[0017] The adsorption unit 10 of this embodiment is disposed by being stacked on the detection unit 20. The adsorption unit 10 adsorbs and concentrates gas. More specifically, the adsorption unit 10 adsorbs and concentrates gas when not heated by the heater 30, and desorbs the adsorbed gas when heated by the heater 30. The gas desorbed from the adsorption unit 10 diffuses toward the detection unit 20. The adsorption unit 10 of this embodiment is formed so as to cover the entire upper surface of the detection unit 20, but may also be formed so as to cover part of the upper surface of the detection unit 20.

[0018] The adsorption section 10 contains an aluminosilicate zeolite having a Si / Al ratio of 1 or more and 2.75 or less. From the viewpoint of improving the gas detection accuracy, the Si / Al ratio of the aluminosilicate zeolite contained in the adsorption section 10 is preferably 1 or more and 2.5 or less, and more preferably 1 or more and 2.25 or less. The Si / Al ratio of the aluminosilicate zeolite can be determined by measuring the Si amount and the Al amount using XRF after cutting out the adsorption section 10 of the gas sensor 100. Note that due to the nature of zeolite, the Si / Al ratio will never be less than 1.

[0019] The pore size of the aluminosilicate zeolite is not particularly limited and is preferably set according to the type of gas to be measured. When the gas to be measured is acetone, the pore size of the aluminosilicate zeolite is preferably 0.6 nm or more (6 Å or more), more preferably 0.7 nm or more (7 Å or more), and even more preferably 0.8 nm or more (8 Å or more), from the viewpoint of improving selectivity to acetone. The upper limit of the pore size of the aluminosilicate zeolite is preferably 1.0 nm or less (10 Å or less). In the present disclosure, the "pore size of the zeolite" refers to the median pore diameter in the pore structure of the zeolite. The pore size of the aluminosilicate zeolite can be determined by cutting out the adsorption portion 10 of the gas sensor 100 and then measuring the peak value of the pore distribution using the BET method under conditions of 77 K and N2 gas.

[0020] The framework of the aluminosilicate zeolite is not particularly limited, and examples thereof include FAU (faujasite), CHA (chabazite), and FER (ferrierite). However, from the viewpoint of further improving gas selectivity, FAU is preferred. The pore diameter of FAU is approximately 0.7 nm, and gases larger than the pore diameter are not adsorbed inside, so that selectivity to acetone in particular can be improved. The cation contained in the aluminosilicate zeolite is not particularly limited, and examples thereof include H + , Na + , K.+ The adsorption section 10 of the present embodiment includes H-FAU zeolite. After cutting out the adsorption section 10 of the gas sensor 100, the aluminosilicate zeolite contained in the adsorption section 10 is subjected to XRD and EPMA to identify the zeolite framework and cation species.

[0021] The detection unit 20 is laminated on the upper surface of the insulating layer 42 in a region corresponding to the through-hole 43, i.e., the region where the diaphragm is formed. The detection unit 20 detects gas desorbed from the adsorption unit 10. Specifically, when the detection unit 20 is heated by the heater 30, an oxidation-reduction reaction occurs between oxygen on the surface of the detection unit 20 and the gas desorbed from the adsorption unit 10. The resistance value of the detection unit 20 changes depending on the transfer of electrons due to this oxidation-reduction reaction. The detection unit 20 is formed of a thin film of an oxide semiconductor. The oxide semiconductor that forms the detection unit 20 is not particularly limited, but examples include tin dioxide (SnO2), tungsten trioxide (WO3), zinc oxide (ZnO), and indium oxide (In2O3). In addition to the oxide semiconductor, the detection unit 20 may also contain a metal such as palladium, platinum, gold, or iridium.

[0022] The pair of electrodes 50 are disposed spaced apart from each other on the upper surface of the insulating layer 42. As shown in FIG. 2, in this embodiment, the pair of electrodes 50 have a comb-like external shape and are made of platinum. Note that the pair of electrodes 50 are not limited to platinum, and may be made of gold, titanium, or the like. As shown in FIG. 1, the pair of electrodes 50 are connected to the detection unit 20 and detect changes in the resistance value of the detection unit 20.

[0023] The gas to be measured in the gas sensor 100 is not particularly limited, but a highly polar gas is suitable. The gas to be measured preferably contains at least one selected from the group consisting of acetone, ethanol, hydrogen, and ammonia, and more preferably contains at least one selected from the group consisting of acetone and ethanol. For example, when acetone and ethanol are contained in the gas to be measured, acetone can be separated and detected by utilizing the difference in polarity between acetone and ethanol.

[0024] The gas sensor 100 of the present disclosure includes an adsorbent 10 containing an aluminosilicate zeolite with a Si / Al ratio of 1 to 2.75. Therefore, the framework is rich in Al and cations that act as charge compensation for Al. The cations form an electric field with the anions that form the framework of the zeolite, specifically improving the desorption activation energy of gases with relatively high polarity. Therefore, when multiple types of gases are adsorbed on the adsorbent 10, gradually heating the adsorbent 10 with the heater 30 allows gases with lower desorption activation energies to be desorbed from the adsorbent 10 and diffused to the detection unit 20 in order.

[0025] The heating rate of the heater 30 is not particularly limited, but from the viewpoint of improving the separation accuracy for multiple types of gases, it is preferably 20°C / min or more and less than 80°C / min, more preferably 30°C / min or more and less than 70°C / min, and even more preferably 40°C / min or more and less than 60°C / min.

[0026] As a specific example of the operation of the gas sensor 100, for example, when the heater 30 is not driven, i.e., when the adsorption unit 10 is not heated, the gas is adsorbed and concentrated in the adsorption unit 10. Thereafter, the heater 30 is gradually heated to a predetermined temperature, for example, about 250°C, to shift the timing of desorption of the measurement target gas and the impurity gas, and then the heater 30 is further heated to a higher temperature, for example, about 300°C to 400°C, to diffuse the gas remaining in the adsorption unit 10. Thereafter, the driving of the heater 30 is stopped, allowing the gas to be adsorbed into the adsorption unit 10 again.

[0027] Generally, acetone and ethanol are hydrophilic molecules with similar molecular diameters, making them difficult to separate in a gas sensor. However, according to the gas sensor 100 of the present disclosure, gradually heating the adsorption unit 10 while acetone and ethanol are adsorbed thereto causes ethanol to desorb first, followed by acetone, which has a higher dipole moment than ethanol, at a higher temperature. Therefore, gradually increasing the temperature of the heater 30 can stagger the desorption times of acetone and ethanol concentrated in the adsorption unit 10, thereby enabling acetone and ethanol to be detected separately. Thus, the gas sensor 100 of the present disclosure can detect multiple gases separately, improving gas selectivity.

[0028] Furthermore, according to the gas sensor 100 of the present disclosure, the adsorption unit 10 adsorbs and concentrates the gas. As a result, the gas can be detected even when the concentration of the gas to be measured is low, thereby improving the sensitivity of the gas sensor 100. Generally, biogases, for example, exhaled breath or emitted from the skin of a living body, are present in trace amounts and contain many impurities, making it difficult to accurately detect a specific gas. However, according to the gas sensor 100 of the present disclosure, the gas selectivity and sensitivity can be improved, making it suitable for measuring biogases for disease testing, health management, personal authentication, detection of illegal drugs such as narcotics, and the like. Applications of the gas sensor 100 are not limited to these, and various other applications include, for example, air quality monitoring, food hygiene management, and detection of hazardous materials such as landmines and explosives.

[0029] The method for manufacturing the gas sensor 100 of this embodiment is not particularly limited, but it can be manufactured, for example, by the following method.

[0030] First, a MEMS substrate is fabricated. For example, a 4-inch silicon wafer with a thickness of 400 μm is cleaned with a cleaning solution, and then an insulating film is formed on both sides of the wafer. To form the insulating film, for example, a silicon oxide film with a thickness of 100 nm is formed by thermal oxidation, a silicon nitride film with a thickness of 200 nm is formed by low-pressure CVD, and a silicon oxide film with a thickness of 100 nm is formed on the entire surface by plasma CVD. On one side of the wafer on which the insulating film has been formed, for example, a tantalum oxide film with a thickness of 20 nm is formed as an adhesion layer by RF sputtering, and then a platinum film with a thickness of 110 nm is formed on top of that by RF sputtering as a heating element. The heater 30 is then fabricated by patterning the film surface into the desired shape using photolithography. Specifically, for example, a photoresist ink is spin-coated on the film surface, forming a film and drying it to form a resist, which is then exposed and developed through a glass mask, and excess portions are removed by wet etching. The heater 30 is formed, for example, in a square spiral shape with an outer periphery of 0.5 mm square and an L / S of 20 μm / 20 μm. The heater 30 is then covered with an insulating film. Specifically, for example, on the surface on which the heater 30 is patterned, a silicon oxide film is formed to a thickness of 100 nm by plasma CVD, and a silicon nitride film is formed to a thickness of 200 nm by low-pressure CVD. This forms the heater 30 embedded in the insulating layer 42.

[0031] Thereafter, contact pads are formed. Specifically, for example, both ends of the heater 30 embedded in the insulating layer 42 are exposed by photolithography and reactive ion etching. Thereafter, for example, a 1 μm gold film is formed by DC sputtering, and then contact pads are formed at two locations on both ends of the exposed heater 30 by photolithography and wet etching. Thereafter, a diaphragm is formed. Specifically, silicon is removed from the surface opposite the surface on which the heater 30 is formed, for example, in an area of ​​1 mm square. To remove the silicon, for example, the insulating film is removed by photolithography and reactive ion etching, and then the exposed silicon is removed by wet etching.

[0032] Thereafter, a pair of electrodes 50 are formed. Specifically, for example, a film of titanium and platinum as an adhesion layer is formed on the insulating layer 42 by RF sputtering, and then the film is patterned by photolithography and wet etching to form the pair of electrodes 50. A spatial gap in which a part of the detection unit 20 is disposed is formed between the pair of electrodes 50. The spatial gap is, for example, 20 μm. The pair of electrodes 50 are connected to a pair of contact pads, respectively. Note that the pair of electrodes 50 may be formed in the same manner as when the contact pads connected to the heater 30 are formed.

[0033] Thereafter, the detection unit 20 is formed on the insulating layer 42 and the pair of electrodes 50. For example, with the base material 40 heated to 450°C, a tin dioxide film is formed to a thickness of 200 nm using RF sputtering, and then a palladium film is similarly formed to a thickness of 1 nm. More specifically, using a metal mask with 0.5 mm square openings, the detection unit 20 is formed in the region corresponding to the through-hole 43 so as to overlap the spiral portion of the heater 30 and the comb-teeth portion of the pair of electrodes 50.

[0034] Thereafter, the adsorption part 10 is formed on the insulating layer 42 and the detection part 20. Specifically, for example, H-FAU type zeolite is first mixed with deionized water to prepare a 5 mg / mL suspension. After dispersing this with a homogenizer, 0.5 μL of the suspension is dropped onto the surface of the detection part 20 and allowed to dry naturally. After that, the adsorption part 10 is formed by baking in an air atmosphere at 500°C for 3 hours. Through the above steps, the gas sensor 100 is manufactured.

[0035] B. Other forms FIG. 3 is a block diagram showing a schematic configuration of a sensor device 200 according to another embodiment of the present disclosure. The sensor device 200 includes the gas sensor 100 according to the above embodiment and an adjustment unit 150. The adjustment unit 150 is realized, for example, by a control device including a microcomputer. The adjustment unit 150 adjusts the temperature rise rate of the heater 30. As a result, the sensor device 200 gradually heats the adsorption unit 10 by gradually raising the temperature of the heater 30. As a result, the multiple gases concentrated in the adsorption unit 10 are desorbed in order, starting with the gas with the lowest desorption temperature, and diffuse to the detection unit 20. Therefore, the multiple gases diffuse to the detection unit 20 with their desorption times staggered, and are detected separately from one another.

[0036] The sensor device 200 of the present disclosure includes the adjustment unit 150 that adjusts the temperature rise rate of the heater 30, and therefore can easily shift the desorption times of the multiple types of gases concentrated in the adsorption unit 10. As a result, the multiple types of gases can be easily separated and detected.

[0037] C. Variations The configuration of the gas sensor 100 in the above embodiment is merely an example and can be modified in various ways. For example, the gas sensor 100 may have the following configuration.

[0038] FIG. 4 is a cross-sectional view schematically illustrating the overall configuration of a gas sensor 100a according to Modification 1. In the gas sensor 100 according to the above embodiment, the adsorption unit 10 is stacked on the detection unit 20. However, the present disclosure is not limited to this configuration. The detection unit 20 may be spaced apart from the adsorption unit 10 as long as it can detect gas desorbed from the adsorption unit 10. For example, as shown in FIG. 4, the gas sensor 100a may include an adsorption unit 10a and a detection unit 20a provided on different substrates 45a and 46a. In this configuration, in addition to a heater 30a for heating the adsorption unit 10a, a heater 31a for heating the detection unit 20a may be embedded in an insulating layer 42a of the substrate 46a on which the detection unit 20a is stacked.

[0039] FIG. 5 is a cross-sectional view schematically illustrating the general configuration of a gas sensor 100b according to Modification 2. In the gas sensor 100 according to the above embodiment, the adsorption unit 10 and the detection unit 20 are separate, but the present disclosure is not limited to this. As shown in FIG. 5, the adsorption unit 10b and the detection unit 20b may be formed from a single member. That is, the adsorption unit 10b and the detection unit 20b may be formed from a member containing a mixture of the components of the adsorption unit 10b and the detection unit 20b. In the example shown in FIG. 5, aluminosilicate zeolite is dispersed as the adsorption unit 10b in tin dioxide as the detection unit 20b.

[0040] FIG. 6 is a cross-sectional view schematically illustrating the general configuration of a gas sensor 100c according to Modification 3. While the gas sensor 100 according to the above embodiment is formed using MEMS, the present disclosure is not limited to this. As shown in FIG. 6, the base material 40c may be formed using an insulating substrate such as an alumina substrate instead of the MEMS. In this embodiment, the heater 30 may be embedded in a region capable of heating the adsorption unit 10. [Example]

[0041] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. Acetone or ethanol was adsorbed onto the zeolites of the examples and comparative examples, and then the desorption spectra were confirmed.

[0042] <Sample> Details of the zeolite samples for forming the adsorbent 10 are shown in Table 1 below.

[0043] [Table 1]

[0044] <Gas adsorption method> A zeolite sample was placed in a container and activated by purging with nitrogen gas for 20 minutes while heating in a heater at 250°C. Gas replacement was then performed by purging with acetone or ethanol for 2 minutes while heating in a heater at 250°C under a nitrogen atmosphere. Then, acetone or ethanol was injected for 60 minutes at room temperature under a nitrogen atmosphere. In both cases, the injected gas concentration was 500 ppm and the gas flow rate was 200 sccm. The zeolites of Example 1, Comparative Example 1, and Comparative Example 2 were used for acetone adsorption, and the zeolites of Example 1 and Comparative Example 1 were used for ethanol adsorption.

[0045] <Gas desorption method> The gas-adsorbed zeolite was analyzed using a TPD instrument. The heating rate was 50°C / min, and the carrier gas was 300 sccm helium. Acetone was detected using a mass spectrum (m / z) of 43, and ethanol was detected using a mass spectrum (m / z) of 45.

[0046] <Acetone desorption results> Fig. 7 is an explanatory diagram showing the acetone desorption spectrum in Comparative Example 1. Fig. 8 is an explanatory diagram showing the acetone desorption spectrum in Example 1. The zeolite of Comparative Example 1 [H-FAU (Si / Al ratio = 250)] had an acetone desorption peak temperature of 121.3°C. In contrast, the zeolite of Example 1 [H-FAU (Si / Al ratio = 2.75)] had an acetone desorption peak temperature of 312.7°C, which was higher than the acetone desorption temperature of the zeolite of Comparative Example 1.

[0047] 9 is an explanatory diagram showing an example of an MS spectrum in Comparative Example 2. In the zeolite of Comparative Example 2 [H-MFI (Si / Al ratio = 12)], the mass spectrum at 43 m / z did not stand out compared to the surrounding mass numbers. In other words, acetone could not be detected in the zeolite of Comparative Example 2. The reason for this is thought to be that the pore diameter of the zeolite of Comparative Example 2 was relatively small at 0.65 nm, and the pore diameter was therefore insufficient for acetone molecules to adsorb and desorb.

[0048] <Ethanol desorption results> FIG. 10 is an explanatory diagram showing the desorption spectrum of ethanol in Comparative Example 1. FIG. 11 is an explanatory diagram showing the desorption spectrum of ethanol in Example 1. In FIGS. 10 and 11, the desorption spectrum of ethanol is shown by a solid line, and the desorption spectrum of acetone is shown by a dashed line. In the zeolite of Comparative Example 1 [H-FAU (Si / Al ratio = 250)], the desorption peak temperature of ethanol and the desorption peak temperature of acetone were almost the same temperature, and the desorption peak temperature difference was 13.7°C. In contrast, in the zeolite of Example 1 [H-FAU (Si / Al ratio = 2.75)], the difference between the desorption peak temperatures of ethanol and acetone was large, and the desorption peak temperature difference was 89.1°C. Therefore, it was found that by using a zeolite with a small Si / Al ratio, a desorption temperature difference of acetone and ethanol can be generated at a level that allows the peaks to be separated.

[0049] The present invention is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit of the present invention. For example, the technical features in the embodiments and examples corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of symbols]

[0050] 10, 10a, 10b... Adsorption portion, 20, 20a, 20b... Detection portion, 30, 30a, 31a... Heater, 40, 40c, 45a, 46a... Base material, 41... Substrate, 42, 42a... Insulating layer, 43... Through hole, 50... Electrode, 100, 100a, 100b, 100c... Gas sensor, 200... Sensor device, 150... Adjustment portion

Claims

1. an adsorption section that adsorbs and concentrates gas; a heater that heats the adsorption unit to desorb the gas from the adsorption unit; a detection unit that detects the gas desorbed from the adsorption unit; A gas sensor comprising: the adsorption section contains an aluminosilicate zeolite having a Si / Al ratio of 1 or more and 2.75 or less, Acetone can be detected as the gas. A gas sensor comprising:

2. 2. The gas sensor according to claim 1, The pore diameter of the aluminosilicate zeolite is 0.6 nm or more, The gas is acetone. A gas sensor comprising:

3. 3. The gas sensor according to claim 1, The framework of the aluminosilicate zeolite is FAU. A gas sensor comprising:

4. The gas sensor according to claim 1 or 2; an adjusting unit that adjusts the temperature rise rate of the heater; A sensor device comprising:

5. 3. A method for detecting acetone and ethanol using the gas sensor according to claim 1, comprising: The heater is gradually heated to stagger the desorption times of the acetone and ethanol concentrated in the adsorption section, thereby separating and detecting the acetone and ethanol. A method characterized by:

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