SE543677C2 - Direct heating and/or self heating micro gas sensor - Google Patents

Direct heating and/or self heating micro gas sensor

Info

Publication number
SE543677C2
SE543677C2 SE2050334A SE2050334A SE543677C2 SE 543677 C2 SE543677 C2 SE 543677C2 SE 2050334 A SE2050334 A SE 2050334A SE 2050334 A SE2050334 A SE 2050334A SE 543677 C2 SE543677 C2 SE 543677C2
Authority
SE
Sweden
Prior art keywords
heater
gas
gas detection
detection element
contact
Prior art date
Application number
SE2050334A
Other languages
Swedish (sv)
Other versions
SE2050334A1 (en
Inventor
Hung Chu Manh
Hung Nguyen Hugo Minh
Hoa Nguyen Duc
Duy Nguyen Van
Toan Nguyen Van
Original Assignee
Hanoi Univ Of Science And Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hanoi Univ Of Science And Technology filed Critical Hanoi Univ Of Science And Technology
Priority to SE2050334A priority Critical patent/SE2050334A1/en
Publication of SE543677C2 publication Critical patent/SE543677C2/en
Publication of SE2050334A1 publication Critical patent/SE2050334A1/en

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
    • G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
    • G01N27/12—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/0004—Gaseous mixtures, e.g. polluted air
    • G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Analytical Chemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Pathology (AREA)
  • Immunology (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Biochemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Combustion & Propulsion (AREA)
  • Medicinal Chemistry (AREA)
  • Food Science & Technology (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)

Abstract

The invention relates to gas sensing devices (10; 20) and systems comprising a thin film gas sensing element and a thin film heater (3), provided on a thermally and electrically isolating substrate. The heater element (3) extends between two heater element terminals (1, 2) and the gas sensing element (4) is at one end connected to a gas sensing element terminal (5) and at the other end connected to the heater element (3).

Description

DIRECT HEATING AND/OR SELF HEATING MICRO GAS SENSOR Field of the invention The present invention relates to micro scale gas sensors, in particular micro scale gas sensorsutilizing electrodes and gas sensing material of metal oxide semiconducting (MOS) material.In particular the invention relates to on-chips heater arrangements to control the temperature of the sensing material.
Background of the invention The need of gas detection can be traced back to the beginning of the coal mining industry forabout 200 years ago. One of the first portable gas detecting devices using catalytic sensorsWas created by Dr Oliver Johnson in 1926. The first gas sensor that employed metal oxidesemiconducting (MOS) material Was invented by Naoyoshi Taguchi in 1968 and shortly afterbecame commercially available by Figaro Engineering. Since that time, research on theminiaturization of gas sensor and on using other MOS material for detecting gases hasincreased. The need of detecting gases in environments such as laboratories, industries, indoorand outdoor environments are increasing rapidly due to the demand on comfort and on earlyWaming of hazardous gases. In many test and fabrication processes, deterrnination of gas concentration is an important issue.
Micro-electro-mechanical system (MEMS) technology has enabled the miniaturization of gassensors in an effective manner, mainly because thin f1lm deposition and patteming becameeasy processes by MEMS. Gas sensors of planar type are suitable for the MEMS techniques,sensor chips can be made in batch processes With high precision at low-cost. A planarMEMS-based gas sensor norrnally composes of a planar substrate on Which heater, electrodesand MOS sensing elements are deposited. The purpose of the on-chip integrated micro heater is to heat up the MOS sensing element.
In micro scale the heat loss during heating of the MOS sensing element is large in relation tothe heat generated. This is because in micro scale the heat source (or heater), yet to be at thetemperature of up to 500 °C, loses its heat to the substrate and to air. In the case of goodtherrnal isolation, the heat gradient from the heat source it large, this stipulates the need ofplacing the heater and the MOS sensing element close to each other. An ideal solution for this heat loss issue Would be an arrangement Where the MOS sensing element is Wrapped around 2 the heater. Unfortunately, this solution cannot be applied easily at low-cost using current MEMS technique, especially for the gas sensor of planar type.
In the prior art there is a need for a micro gas sensor With reduced heat loss and powerconsumption. The present invention is related to this heat loss and thus power consumption problem, at the same time With the designing of a multi gas sensor on the same chip.
Summary of the inventionThe object of the invention is to provide a micro gas sensor and system that overcomes thedraWbacks of prior art devices and systems With regards to the heating and temperature control of the sensing material in the sensor.
This is achieved by the micro gas sensor as defined in claim 1, and the system as defined in claim 7.
Thanks to the invention there is provided a gas sensing device comprising a thin film gassensing element, and a thin film heater element provided on a therrnally and electricallyisolating substrate, Wherein the heater element extends between and is at each end isconnected to a first and a second heater element terminal. The gas sensing element isextended between a first and a second end and is at the first end in contact With a gas sensing element terminal and at the second end in contact With the heater element.
In one embodiment of the invention there is a gas sensing device comprising at least a firstgas sensing element and a second gas sensing element Wherein first gas sensing element at itsfirst end is in contact With a first gas sensing element terrninals and at its second end is incontact With the heater element. The second gas sensing element is at its first end in contactWith a second gas sensing element terminal and at its second end is in contact With the heater element.
It is an advantage to reduce the amount of gas sensing element terrninals in a gas sensing device.
In one embodiment of the invention the heater element is provided With at least a first heatersection arranged to provide a first heating capacity and a second heater section arranged to provide a second heater capacity. The first gas sensing element is in contact With the first heater section and the second gas sensing element is in contact With the second heater section.
In one embodiment the first heater section and the second heater section have the same thickness and different Widths.
It is an advantage With the invention that the gas sensing element may have different temperatures.
In one embodiment of the invention the gas sensing device comprises at least five thin film gas sensing elements Wherein the first gas sensing element is at its first end in contact With a 4 first heating section and at its second end in contact with a first gas sensing element terminal,the second gas sensing element is at its first end in contact with a second heating section andat its second end in contact with a second gas sensing element terminal, the third gas sensingelement is at its first end in contact with a third heating section and at its second end in contact with a third gas sensing element terminal, the fourth gas sensing element is at its firstend in contact with a fourth heating section and at its second end in contact with a fourth gassensing element terminal, and the f1fth gas sensing element is at its first end in contact with a f1fth heating section and at its second end in contact with a f1fth gas sensing element terminal.
In one embodiment of the invention the heater element has a gradually changing widthbetween the first and the second heater element terminal thereby providing a graduallychanging heating capacity along the length of the heater element. A first gas sensing elementis in contact with a first position of the heater element and at least a second gas sensing element is in contact with a second position of the heater element.
It is an advantage with the invention that a micro gas sensor that has a power consumption in the range of tens mW to uW may be provided.
It is a further advantage of the invention that a micro gas sensor that is capable to be used in battery driven handheld devices may be provided.
According to one aspect of the invention a gas sensing system is provided. The gas sensingsystem comprises a gas sensing device as described above, and a driving and measurementunit arranged to apply a voltage to the heater element or heating sections and to measure the resistance over the gas sensing element or gas sensing elements.
In one embodiment of the gas sensing system the first heater element terminal is set to a higher potential than the second heater element terminal.
In one embodiment of the gas sensing system the driving and measurement unit is arranged toapply a voltage between the first heater element terminal and the gas sensing elementterminal, or between the plurality of gas sensing element terminal, and to measure theresistance over the gas sensing element, or gas sensing elements between the first heaterelement terminal and the gas sensing element terminal, or the plurality of gas sensing element terrninals.
In the following, the invention Will be described in more detail, by Way of example only, Withregard to non-liniiting en1bodin1ents thereof, reference being n1ade to the acconipanying drawings.
Brief description of the drawings Figure 1 is a schematic illustration of a micro gas sensor according to the prior art; Figure 2 is a schematic illustration of a micro gas sensor according to the invention; Figure 3 is a schematic illustration of one embodiment of the invention; Figure 4 is a temperature simulation of one embodiment of the invention; Figure 5 is a micrograph of one experiment; Figure 6 is an illustration of a temperature test of one experiment; and Figure 7 is a schematic illustration of one embodiment of the invention.
Detailed description 77 CC 77 CC Terms such as ”top , bottom”, upper”, lower”, “below , above” etc., are used merely withreference to the geometry of the embodiment of the invention shown in the drawings and/or during norrnal operation and are not intended to limit the invention in any manner.
Throughout the drawings, the same reference numbers are used for similar or corresponding elements.
Despite of the fact that the design in Fig. l is not belong to the invention, it is included here to serve as reference so that detail description of the invention can be made effectively.
A gas sensor in micro scale using MOS sensing material normally comprises a substrate, e. g.a thin chip, on which a pair of separated electrodes and a sensing material are provided. Thesensing material can be a thin film, nanoparticles, nanorods or nanowire of metal oxidesemiconducting (MOS) material that bridges the two electrodes. For the MOS material to besensitive towards a certain gas constituent it norrnally needs to be heated up. Instead of havingan external heater, it is convenient to integrate one on the substrate, in vicinity to the sensingmaterial. Despite of efforts of making therrnal isolation for the heater the power consumption,almost only for heating, can still be in the range from several hundred mW to a few W,despite that the gap between the heater and the sensing material is brought down to few um.
This may specially be a problem for battery driven handheld devices.
The basic principle is that the heat needed for the MOS sensing material is transferred fromthe heater via the substrate by therrnal conduction, and/or via air or gas by therrnal convectionand by irradiation. This invention relates to a micro gas sensor designed for minimizing heatloss and thus power consumption that mainly goes to the need of heating the MOS sensing element.
The prior art design norrnally comprises an on-chip integrated resistive heater, and a MOSsensing element in between two electrodes. The MOS sensing element is located in vicinity(typically a few um) of a heater, e. g. a meander heater, to receive as much heat as possible.Much effort has been put in therrnal isolation and minimizing this tiny distance, but the powerconsumption of a single sensor is still high. Figure l shows a micro gas sensor according tothe prior art. The micro gas sensor comprises a first l and a second 2 heater terminal, a heater3, a MOS sensing element 4, and a first 5 and a second 6 gas sensing element terminal, provided on a substrate. By applying a voltage on the first l and second 2 heater terrninals, 8 heat will be generated at the heater 3, and transfer to the MOS sensing element 4. Resistanceof the MOS sensing element 4 is measured between the first 5 and the second 6 gas sensingelement terminal. The amount of heat from the heater 3 that reaches the MOS sensing element4 depends on the therrnal conducting properties of the substrate, as well as therrnal irradiationand conVection condition in the area in between the MOS gas sensing element 4 and the heater 3.
Fig. 2 shows a schematic illustration of a micro gas sensor 10 according to the inVention. Ascan be seen in the figure in a micro gas sensor 10 according to the inVention the thin film (orMO S) gas sensing element 4 is in contact with the heater element 3. In this way when aVoltage is applied on the first 1 and second 2 heater terrninals, heat will be generated at heater3 and directly transferred to the thin film gas sensing element 4, i.e. direct heating mode.Resistance of the thin film gas sensing element 4 is measured between the first heater terminal1 and the gas sensing terminal 5. Notably, all parts of the micro gas sensor, i.e. the first 1 andsecond 2 heater terminal, the heater 3, the MOS sensing element 4, and the gas sensingelement terminal 5 may be deposited and pattemed on a therrnally isolating substrate (a chip)as thin films. In some embodiments of the inVention the first heater terminal 1 is set to a highpotential (for example 3 Volts), and the second heater terminal 2 is set to a low potential(Ground). Thus, the first heater terminal 1 may be the common source for the heater 3 and thethin film gas sensing element 4. As molecules of a gas come in contact with the surface of thethin film gas sensing element 4, its resistance will be changed and registered at the gas sensing element terminal 5. The measured resistance corresponds to concentration of the gas.
In a micro gas sensor 10, or a gas sensing device, according to the invention only oneterminal, e.g. the gas sensing element terminal 5, is needed for measuring the resistance of thethin film gas sensing element 4. This in contrast to a micro gas sensor according to the priorart that requires two separate gas sensing element terrninals at either ends of the gas sensing element for the same task, illustrated as the first 5 and second 6 gas sensing element in Figure 1.
Reducing the amount of gas sensing element terrninals required in a micro gas sensor is anadvantage, especially for designs comprising a multitude of gas sensing elements (or multi gas sensors) on the same chip, as will be discussed further below. 9 Fig. 3 shows a schematic illustration of one embodiment of the invention. It shows anillustration of a gas sensing device 20 comprising a multitude (here five, as an example) ofthin film gas sensing elements 41; 42; 43; 44; 45. The direct heating principle is the same asdescribed for the micro gas sensor 10 in Fig. 2, with the exception that in Fig. 3 the five thinfilm gas sensing elements 41; 42; 43; 44; 45 are in contact with a heating section 31; 32; 33;34; 35, so that there is one specific heater for each gas sensing element, and also one specificgas sensing element terminal 51; 52; 53; 54; 55. For example, the first thin film gas sensingelement 41 is at one end in contact with the first heating section 31 and at the other end incontact with the first gas sensing element terminal 51. According to one embodiment (notshown) there may be one common heater 3 connected to all thin film gas sensing elements 41; 42; 43; 44; 45.
Since the heating sections 31; 32; 33; 34; 35 are a thin film material, they may have differentwidths (for 31 through 35) in order to obtain different resistances and thus differenttemperatures, in other words the heating sections may have different heating capacities, forthe different gas sensing elements 41; 42; 43; 44; 45. An advantage with having differenttemperatures, or heating capacities, is that different gases react differently strong with the gassensing elements 41; 42; 43; 44; 45 (that norrnally are composed of the same material)depending on temperature. Thus, each of the thin film gas sensing elements 41; 42; 43; 44; 45may be used for a specific gas, i.e. several different gases may be detected by a gas sensingdevice 20 according to the invention. For example, five different gases may theoretically bedetected and quantified. For better discrimination and quantification of the measured gases in a gas mixture dedicated software (preferably with machine leaming capability) can be used.
The embodiments shown in Fig. 3 further demonstrates an advantage in striving forminimizing power consumption for heating, since the five heating sections 31; 32; 33; 34; 35constitute the common heater 3 and thus wasted heat is minimal compared with five single gas sensors on five separate chips.
The embodiments shown in Fig. 3 additionally provide another altemative operation modethan the direct heating mode, namely self-heating mode, in which a voltage can be appliedbetween the first heater terminal 1 and the fifth heating section 55, for example. In such case,the fifth thin film gas sensing element 45 will be heated up by itself and its resistance can be measured between the same terrninals. The remaining thin gas sensing elements 41; 42; 43; 44; 45 may operate in the same way, but at different temperature depending on the appliedvoltages. Notably, the direct heating mode and the self-heating mode can be used in combination at the same time and in the same gas sensing device.
According to one aspect of the invention a gas sensing system is provided. The gas sensingsystem comprises a gas sensing device 10; 20 as described above and a driving andmeasurement unit arranged to apply a voltage to the heater element 3 or heating sections 31;32; 33; 34; 35 and to measure the resistance over the gas sensing element 4 or gas sensing elements 41; 42; 43; 44; 45.
According to one embodiment the driving and measurement unit is arranged to operateaccording to the direct-heating mode described above. The driving and measurement unit isarranged to apply a voltage between the first heater element terminal 1 and the second heaterelement terminal 2, and to measure the resistance over the gas sensing element 4 at the gassensing terminal 5, or over the plurality of gas sensing elements 41; 42; 43; 44; 45 at the gassensing terrninals 51; 52; 53; 54; 55 if a plurality of gas sensing elements 41; 42; 43; 44; 45are used. The resistance is measured between the first heater element terminal 1 and the gassensing element terminal 5 or the plurality of gas sensing element terminal 51; 52; 53; 54; 55.A schematic illustration of such an embodiment is shown in Figure 7, showing an example ofa set-up for data acquisition for such an embodiment. The voltage is preferably applied so thatthe first heater element terminal 1 is set to a higher potential than the potential of the secondheater element terminal 2. The potential of the second heater element terminal 2 is typically set to zero (ground).
According to one embodiment the driving and measurement unit is arranged to operateaccording to the self-heating mode described above. The driving and measurement unit isarranged to apply a voltage between the first heater element terminal 1 and the gas sensingelement terminal 5 or the plurality of gas sensing element terminal 51; 52; 53; 54; 55 if aplurality of gas sensing elements are used, and to measure the resistance over the gas sensingelement 4 or gas sensing elements 41; 42; 43; 44; 45 between the first heater element terminal1 and the gas sensing element terminal 5 or the plurality of gas sensing element terrninals 51; 52; 53; 54; 55. 11 It is possible to exchange the first heater element terminal 1 with the second heater elementterminal 2 so that the second heater element terrninal 2 is set to a higher potential than the first heater terrninal 1.
All embodiments and aspects can be combined with each other unless specifically stated otherwise.
EXPERIMENTS Fig. 4 shows an experiment where a result of a therrnal simulation of a gas sensing device 10illustrated Fig. 3 using the software Comsol is showed. The heating sections 31; 32; 33; 34;35, the heater terrninals 1; 2, the gas sensing element terrninals 51; 52; 53; 54; 55 are ofplatina with thickness of 100 nm. The applied Voltage between the first 1 and second 2 heaterterminal was 1.0 Volt. It is found that the heating sections 31; 32; 33; 34; 35, each 30 umlong, with the widths of 4.8; 6.5; 8.2; 10.8 and 17 um, respectively, provided the temperature337 °C; 287 °C; 237 °C; 189 °C and 140 °C, respectively.
Complete gas sensor devices were fabricated using deposition and patteming of thin filmtechnique. In the case where gas sensing elements are not a pattemed thin film, but insteadnanowires or nanorods, they are grown in a chemical vapor deposition step or in a hydrotherrnal growth step. The gas sensors can be fabricated in batch process.
Fig. 5 shows a part of a gas sensor 20 as the one described in Fig. 3 before the gas sensingelements 41; 42; 43; 44; 45 are deposited. Notably, the gas sensor itself, or the sensorsthemselves, occupy an area of less than 200><200 umz on the much larger substrate thatpractically may be 1><1 mmz or smaller, although 4><4 mmz or larger substrates are often made in laboratories for easy handling.
The first step of testing of the fabricated sensors is to test the heater until failure. As anexample, the heater was designed for the maximum operating temperature of 337 °C but thetest showed that it survived that temperature and broke at a higher temperature. It wasdesigned for the applied voltage of 1.0 Volt but it broke in the real test at approximately 6.0-6.5 Volts. Fig. 6 shows such a heater during the test until failure, taken by an IR camera (Flir,Therrnovision A40)

Claims (10)

:: 1. Gasdetektor (10; 20) innefattande ett gasdetekterande tunnfilmselement (4), och etttunnfilmsvärmarlement tillhandahållet på ett termiskt och elektriskt isolerande substrat, varvidvärmarelementet (3) är utsträckt mellan och är anslutet till en första (1) och en andra (2)värmarelementterminal, kännetecknad av att gasdetektionselementet (4) är utsträckt mellan enförsta och andra ände och vid den första änden är i kontakt med en gasdetektionselementterminal(5) och vid den andre änden i kontakt med värmarelementet (3).A gas detector (10; 20) comprising a gas detecting thin film element (4), and a thin film heating element provided on a thermally and electrically insulating substrate, the heating element (3) extending between and connected to a first (1) and a second (2) heating element terminal. , characterized in that the gas detection element (4) extends between one first and second end and at the first end is in contact with a gas detection element terminal (5) and at the other end in contact with the heater element (3). 2. Gasdetektorn (20) enligt krav 1, innefattande åtminstone ett första gasdetektionselement (41) ochett andra gasdetektionselement (42), varvid det första gasdetektionselementet (41) vid sin förstaände är i kontakt med en första gasdetektionselementterminal (51) och vid sin andra ände är ikontakt med värmarelementet (3), varvid det andra gasdetektionselement (42) vid sin första ände äri kontakt med en andra gasdetektionselementterminal (52) och vid sin andra ände är i kontakt medvärmarelementet (3).The gas detector (20) according to claim 1, comprising at least a first gas detection element (41) and a second gas detection element (42), the first gas detection element (41) at its first end being in contact with a first gas detection element terminal (51) and at its second end is in contact with the heater element (3), the second gas detection element (42) at its first end being in contact with a second gas detection element terminal (52) and at its second end being in contact with the heater element (3). 3. Gasdetektorn (20) enligt krav 1 eller 2, varvid värmarelementet (3) är försedd med åtminstone enförsta värmarsektion (31) anordnad att tillhandahålla en första värmarkapacitet och en andravärmarsektion (32) anordnad att tillhandahålla en andra värmarkapacitet och varvid det förstagasdetektionselementet (41) är i kontakt med den första värmarsektionen (31) och det andragasdetektionselementet (42) är i kontakt med den andra värmarsektionen (32).The gas detector (20) according to claim 1 or 2, wherein the heating element (3) is provided with at least one first heating section (31) arranged to provide a first heating capacity and a second heating section (32) arranged to provide a second heating capacity and wherein the first gas detection element (41 ) is in contact with the first heater section (31) and the second gas detection element (42) is in contact with the second heater section (32). 4. Gasdetektorn (20) enligt krav 3, varvid den första värmarsektionen (31) och den andravärmarsektionen (32) har samma tjocklek men olika bredd.The gas detector (20) according to claim 3, wherein the first heater section (31) and the second heater section (32) have the same thickness but different widths. 5. Gasdetektorn (20) enligt krav 4, varvid gasdetektionselementet (41) innefattar åtminstone femgasdetektionselementet (41; 42; 43; 44; 45) varvid det första gasdetektionselementet (41) vid sinförsta ände är i kontakt med den första värmarsektionen (31) och vid sin andra ände är i kontakt medden första gasdetektionselementterminalen (51), det andra gasdetektionselementet (42) vid sinförsta ände är i kontakt med den andra värmarsektionen (32) och vid sin andra ände är i kontakt medden andra gasdetektionselementterminalen (52), det tredje gasdetektionselementet (43) vid sinförsta ände är i kontakt med den tredje värmarsektionen (33) och vid sin andra ände är i kontakt medden tredje gasdetektionselementterminalen (54), det fjärde gasdetektionselementet (44) vid sinförsta ände är i kontakt med den fjärde värmarsektionen (34) och vid sin andra ände är i kontakt medden fjärde gasdetektionselementterminalen (54), och det femte gasdetektionselementet (45) vid sinförsta ände är i kontakt med den femte värmarsektionen (35) och vid sin andra ände är i kontakt medden femte gasdetektionselementterminalen (55).The gas detector (20) according to claim 4, wherein the gas detection element (41) comprises at least the five gas detection element (41; 42; 43; 44; 45), the first gas detection element (41) at its first end being in contact with the first heater section (31) and at its second end is in contact with the first gas detection element terminal (51), the second gas detection element (42) at its first end is in contact with the second heater section (32) and at its second end is in contact with the second gas detection element terminal (52), the third the gas detection element (43) at its first end is in contact with the third heater section (33) and at its second end is in contact with the third gas detection element terminal (54), the fourth gas detection element (44) at its first end is in contact with the fourth heater section (34 ) and at its second end is in contact with the fourth gas detection element terminal (54), and the fifth gas detection element (45) at its first end is in contact with the n the fifth heater section (35) and at its other end is in contact with the fifth gas detection element terminal (55). 6. Gasdetektorn (10, 20) enligt krav 1, varvid värmarelementet (3) uppvisar en gradvis förändring ibredd mellan den första (1) och den andra värmarelementterminalen och därmed tillhandahåller engradvis förändring av värmarkapaciteten längs värmarelementets (3) längd, och varvid det första gasdetektionselementet (41) är i kontakt med värmarelementet (3) vid en första position ochåtminstone ett andra gasdetektionselementet (42) är i kontakt med värmarelementet (3) vid enandra position.The gas detector (10, 20) according to claim 1, wherein the heating element (3) exhibits a gradual change in width between the first (1) and the second heating element terminal and thus provides a gradual change of the heating capacity along the length of the heating element (3), and wherein the first the gas detection element (41) is in contact with the heater element (3) at a first position and at least one second gas detection element (42) is in contact with the heater element (3) at a second position. 7. Ett gasdetekterande system innefattande gasdetektorn (10, 20) enligt krav 1-6, och en driv- ochmätenhet, varvid driv- och mätenheten är anordnat att anbringa en spänning över värmarelementet(3) eller värmarsektionerna (31; 32; 33; 34; 35) och att mäta resistansen övergasdetektionselementet (4) eller gasdetektionselementen (41; 42; 43; 44; 45).A gas detecting system comprising the gas detector (10, 20) according to claims 1-6, and a drive and measuring unit, wherein the drive and measuring unit is arranged to apply a voltage across the heater element (3) or the heater sections (31; 32; 33; 34 ; 35) and measuring the resistance of the supergas detection element (4) or the gas detection elements (41; 42; 43; 44; 45). 8. Gasdetekterande systemet enligt krav 7, varvid driv- och mätsystemet är anordnat att anbringa enspänning över den första värmarelementterminalen (1) och den andra värmarelementterminalen (2),och att mäta resistansen över gasdetektionselementet (4) mellan den förstavärmarelementterminalen (1) och gasdetektionselementterminalen (5), eller att mäta resistansenöver gasdetektionselementen (41; 42; 43; 44; 45) mellan den första värmarelementterminalen (1)och gasdetektionselementterminalerna (51; 52; 53; 54; 55).The gas detecting system according to claim 7, wherein the drive and measuring system is arranged to apply a single voltage across the first heater element terminal (1) and the second heater element terminal (2), and to measure the resistance of the gas detection element (4) between the first heater element terminal (1) and the gas detection element terminal. (5), or measuring the resistance across the gas detection elements (41; 42; 43; 44; 45) between the first heater element terminal (1) and the gas detection element terminals (51; 52; 53; 54; 55). 9. Gasdetekterande systemet enligt krav 8, varvid den första värmarelementterminalen (1) är satt tillen högre potential än den andra värmarelementterminalen (2).The gas detecting system according to claim 8, wherein the first heating element terminal (1) is set to a higher potential than the second heating element terminal (2). 10. Gasdetekterande systemet enligt krav 7, varvid driv- och mätsystemet är anordnat att anbringaen spänning över den första värmarelementterminalen (1) och gasdetektionselementterminalen (5)eller flertalet gasdetektionselementterminalerna (51; 52; 53; 54; 55) den andravärmarelementterminalen (2), och att mäta resistansen över gasdetektionselementet (4) ellerflertalet gasdetektionselementen (41; 42; 43; 44; 45) mellan den första värmarelementterminalen (1)och gasdetektionselementterminalen (5), eller flertalet gasdetektionselementterminalerna (51; 52;53; 54; 55).The gas detecting system according to claim 7, wherein the drive and measuring system is arranged to apply voltage across the first heater element terminal (1) and the gas detection element terminal (5) or the plurality of gas detection element terminals (51; 52; 53; 54; 55) the second heater element terminal (2), and measuring the resistance of the gas detection element (4) or the plurality of gas detection elements (41; 42; 43; 44; 45) between the first heater element terminal (1) and the gas detection element terminal (5), or the plurality of gas detection element terminals (51; 52; 53; 54; 55).
SE2050334A 2020-03-26 2020-03-26 Direct heating and/or self heating micro gas sensor SE2050334A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
SE2050334A SE2050334A1 (en) 2020-03-26 2020-03-26 Direct heating and/or self heating micro gas sensor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE2050334A SE2050334A1 (en) 2020-03-26 2020-03-26 Direct heating and/or self heating micro gas sensor

Publications (2)

Publication Number Publication Date
SE543677C2 true SE543677C2 (en) 2021-06-01
SE2050334A1 SE2050334A1 (en) 2021-06-01

Family

ID=76160059

Family Applications (1)

Application Number Title Priority Date Filing Date
SE2050334A SE2050334A1 (en) 2020-03-26 2020-03-26 Direct heating and/or self heating micro gas sensor

Country Status (1)

Country Link
SE (1) SE2050334A1 (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4744246A (en) * 1986-05-01 1988-05-17 Busta Heinz H Flow sensor on insulator
US5605612A (en) * 1993-11-11 1997-02-25 Goldstar Electron Co., Ltd. Gas sensor and manufacturing method of the same
US20040099047A1 (en) * 2002-11-25 2004-05-27 Raisanen Walfred R. Thin film gas sensor
US7461540B2 (en) * 2006-04-29 2008-12-09 Moenkemoeller Ralf Metal-oxide gas sensor
WO2009045448A2 (en) * 2007-10-01 2009-04-09 Scott Technologies, Inc. Gas measuring device and method of manufacturing the same

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4744246A (en) * 1986-05-01 1988-05-17 Busta Heinz H Flow sensor on insulator
US5605612A (en) * 1993-11-11 1997-02-25 Goldstar Electron Co., Ltd. Gas sensor and manufacturing method of the same
US20040099047A1 (en) * 2002-11-25 2004-05-27 Raisanen Walfred R. Thin film gas sensor
US7461540B2 (en) * 2006-04-29 2008-12-09 Moenkemoeller Ralf Metal-oxide gas sensor
WO2009045448A2 (en) * 2007-10-01 2009-04-09 Scott Technologies, Inc. Gas measuring device and method of manufacturing the same

Also Published As

Publication number Publication date
SE2050334A1 (en) 2021-06-01

Similar Documents

Publication Publication Date Title
US10598621B2 (en) Gas sensing device with chemical and thermal conductivity sensing
CN101213425B (en) Interdigitated, full wheatstone bridge flow sensor transducer
US9995593B2 (en) Method for operating a sensor array
US20160187279A1 (en) Metal oxide gas sensor array devices, systems, and associated methods
US11474056B2 (en) Sensor for determining the thermal capacity of natural gas
US7635091B2 (en) Humidity sensor formed on a ceramic substrate in association with heating components
US11175190B2 (en) Device and method for the in-situ calibration of a thermometer
CN102004125B (en) Thermal humidity sensor
Kang et al. Temperature control of micro heater using Pt thin film temperature sensor embedded in micro gas sensor
CN108700539A (en) CMOS integrated micro-heaters for gas sensor device
CN101408442A (en) Air mass flow sensor of silicone base thin-film structure
SE543677C2 (en) Direct heating and/or self heating micro gas sensor
JP2007322355A (en) Gas sensor and gas detection system
US20200049647A1 (en) Sensor Device and Electronic Assembly
US6361204B1 (en) Device for measuring the thermal conductivity of a fluid
US20220128502A1 (en) Sensor Device and Method for Operating A Sensor Device
Sabate et al. Multisensor chip for gas concentration monitoring in a flowing gas mixture
CN112189129B (en) Integral temperature control within diagnostic test sensor
Simon et al. In-situ pressure measurements of encapsulted gyroscopes
de Almeida et al. On the modeling of new tunnel junction magnetoresistive biosensors
Zhang et al. Thermal conductivity measurement system for molecules-based compounds available in a wide temperature region
WO2002073175A1 (en) Zero shift compensation oxygen sensor
JP2008046143A (en) Thermal fluid sensor and flow sensor
KR20080079486A (en) Contact combustion mode gas sensor form micromachine

Legal Events

Date Code Title Description
NUG Patent has lapsed