An improved chemiresistive gas sensor module with in-built electromagnet and gas detection method thereof

Abstract

An improved gas sensor module with in-built electromagnet and gas detection method thereof comprises base (002), metal pins (003), cylindrical substrate (004), PVC module cover (005), polymeric mesh (006), planar substrate (007), sensor module with integrated electromagnet (008), copper coil using which the electromagnet was prepared (009), sensor module cover with in-built electromagnet connected with voltage source for current flow and magnetic field generation (010). The present invention provides a more compact, cost-effective, reliable, and user-friendly solution for hassle-free "on demand- on spot magnetic field assisted sensing" by integrating an electromagnet directly with a sensor module. Charge flow through the solenoid produces homogeneous magnetic field flux directed perpendicularly to the gas sensor. The magnetic field strength precisely tuned by regulating the charge flow through the solenoid using a voltage source. The generated field will help to achieve higher sensing responses by chemiresistive sensing materials. Use of a magnetic field in this way often generate low- concentration gas detection ability in a sensor, which is otherwise not detectable by the same.

Description

AN IMPROVED CHEMIRESISTIVE GAS SENSOR MODULE WITH IN-BUILT ELECTROMAGNET AND GAS DETECTION METHOD THEREOFFIELD OF THE INVENTION

[0001] The present invention relates to an improved gas sensor module with an in-built electromagnet and gas sensing detection method thereof.

[0002] More specifically, the invention pertains to chemiresistive gas sensing technology and more specifically to an electromagnet-embedded gas sensor module developed for improving the sensing performance and detection ability of chemiresistive gas sensors under the influence of the magnetic field.BACKGROUND OF THE INVENTION

[0003] Chemiresistive gas sensing is a technology that involves measuring changes in the electrical resistance of sensing material in response to exposure to specific gases or volatile organic compounds (VOCs). Chemiresistive gas sensors play a crucial role in a wide range of industries, such as environmental monitoring, industrial safety, and healthcare for the measurement of the concentration of specific gases or VOCs. They are extensively employed due to their advantages, including fast and sensitive detection of target substances in the environment, cost-effectiveness, production flexibility, and ease of use. Ongoing research in chemiresistive gas sensing has led to the development of various techniques aimed at enhancing sensors’ sensitivity. These methods include nano-scale engineering, surface functionalization, and surface modification, which have proven effective in improving the sensing response of chemiresistive gas sensors, although most of these existing methods for enhancing chemiresistive sensing response typically require complex synthesis processes, which can often be resource-consuming and consequently costly. Furthermore, as most of the methods for optimizing sensitivity involve chemical synthesis, reproducibility of each parameter at the time of synthesis is very challenging. While sensitivity can be enhanced through external stimuli such as UV and visible light exposure, as well as temperature variation, these techniques are primarily utilized for refining the sensing properties of chemiresistive sensors, rather than enabling real-time, on-demand adjustments.

[0004] Chemiresistive gas sensors are essential in various industries, including environmental monitoring, industrial safety, and healthcare for the detection of gases or VOCs and measuring the concentration of a specific gas or VOC. So far, normal sensor modules have been used in sensing experiments, yet, very recently in 2022, it has been discovered that application of magnetic field can enhance response of chemiresistive gas sensors. However, from prior art search, there exists no gas sensor module with embedded electromagnet, which will be required for magnetic field induced gas sensing.

[0005] Reference be made to the patent of ‘Multifunctional compound sensor’ having patent number, W02005 / 031273A1, wherein the sensor module comprises a base designed to accommodate a substrate coated with sensing material, with the components enclosed by a protective cap. The response values achieved using these modules primarily rely on the characteristics of the sensing materials, thereby to attain a higher response, modifications to sensing materials are required, which can be a laborious task.

[0006] Reference be made to the patent of ‘Semi-conductor gas sensor with temperature compensation function’ having Chinese patent number CN 203365368 U wherein a heating coil around the substrate is involved, which is then integrated into a sensor module of previous design. The response values achieved using these modules primarily rely on the characteristics of the sensing materials and the control of temperature, therefore achieving higher response, modifications in sensing materials or temperature is required which is cumbersome.

[0007] Various techniques have already been established for improving the sensing performance of these chemiresistive gas sensors such as surface modification, nanostructure formation, use of UV radiation as external stimuli, modification of crystal and electronic structure, and so on.

[0008] Reference be made to the Indian patent of “magnetic-electric gas sensor arrangement’ having patent number, IN 201831017951 A, wherein electromagnet has been introduced as a different set-up. This configuration also does not incorporate an electromagnet directly on the sensor module to enhance sensing responses.

[0009] By reference to PCT Patent application number PCT / KR2003 / 002151 discloses a compound sensor that has multiple functions. This compound sensor is especially usedin the car or the house and is formed into one package to check temperature, humidity, and gas simultaneously is comprising that covering material which is formed to cover on the upper side, supporting body material which binds to the lower limit of the said covering material, the multiplicity of linking pin material inserted among a multiplicity of insulating glass formed to multiplicity on the said supporting body material, the board material set up to separate and fix on the upper limit section of the said linking pin material and sensor chip formed to the multiplicity of the chip to detect temperature, humidity, and gas on upper limit of the said board material. However, this invention does not reveal about the integrated solenoid coil wrapped around the cap of the sensor module for the generation of the electromagnetic field.

[0010] By reference to IN Patent application number IN201831017951 discloses a gas sensor arrangement for determining a gas concentration. More specifically, the present invention discloses an improved highly sensitive gas sensor arrangement suitable for detecting small amounts of gas in the ambient atmosphere by a suitable nanocrystalline transition metal doped oxide semiconductor in the presence of an external DC electric field applied along the longitudinal direction and also an external magnetic field applied transverse direction. Whereas, in the present invention as soon as current passes through the solenoid coil wound on the gas sensor module, it generates the electromagnetic field at the core of the gas sensor module for improved detection behavior of the sensor.[Oi l] Thus, keeping in view the drawbacks of the hitherto reported prior arts, there is an immediate need of improving the sensing performance of these chemiresistive gas sensors.

[0012] However, none of the above-discussed inventions provides such an improved gas sensor module with an in-built electromagnet and gas detection method thereof. The improved gas sensor module comprises a base, metal pins, cylindrical or planar substrate sensor substrate, PVC module cover, polymeric mesh, integrated electromagnet made of copper coil tightly wound around the cap of the module.OBJECTIVES OF THE INVENTION

[0013] The main objective of the present invention is to provide an improved gas sensor module with an in-built electromagnet and gas sensing detection method thereof.

[0014] Another object of the present invention is to provide a compact electromagnetic embedded sensor module intended for improving point of care sensing performance and capability of chemiresistive gas sensor.

[0015] Another object of the present invention is to provide a method of gas detection in which a sensor module creates a magnetic field within the module’s core that helps in getting improved response towards the target gas and enhances the detection limit of the sensor.

[0016] Still, another object of the present invention is to provide more compactness along with a streamlined, cost-effective, reliable, and user-friendly solution for hassle-free “on demand- on-spot magnetic field assisted sensing” by integrating an electromagnet directly with sensor module.SUMMARY OF THE INVENTION

[0017] Accordingly, the present invention provides an improved gas sensor module with an inbuilt electromagnet and gas detection method thereof which comprises a chemiresistive gas sensor, more specifically the module of chemiresistive gas sensor and an electromagnet attached to the cap of the module.

[0018] In another aspect of the invention, the sensor module comprises a PVC-made module base wherein six metallic pins are affixed for attaching sensors and the base is enclosed by a polymeric cap with an opening at the top using a polymeric mess. Then a solenoid around the PVC-made cylindrical cap of the sensor module using insulated copper wire has been integrated. To ensure the stability of the entire setup, a polymeric sheet has been wrapped around the entire assembly.

[0019] In another aspect of the invention, the electromagnet source incorporated sensing module is configured in such a way so that the solenoid produce a uniform magnetic field around the sensor module. The voltage source generates charge flow through the enameled copper coil-based solenoid. As current passes through the solenoid, it creates a magnetic field within the solenoid’s core according to Ampere’s law. In a solenoid, electronic charges flow through the coil, generating a magnetic field directed perpendicular to the plane of charge flow. Nevertheless, the combined impact of the current flowing through the wire and the number of turns within the solenoid leads to anaccumulative effect, producing a robust and fairly uniform magnetic field within the core of the solenoid. Therefore, it is feasible to adjust magnetic field strength at a specific point in the vicinity of the sensor by controlling magnetic flux density through the manipulation of both the number of turns in the coil and the current passing through it, achieved by varying the voltage.

[0020] In accordance with the other aspect of the present disclosure, enhancement in the sensing response of different chemiresistive gas sensors towards their target gases due to the magnetic field has been observed in a more straightforward manner.

[0021] In another aspect of the present invention, this sensor module comprises a PVC-made module base wherein six metallic pins are affixed for attaching sensors and the base is enclosed by a polymeric cap with an opening at the top using a polymeric mess.

[0022] In another aspect of the present invention, solenoids, comprising enameled copper coils with 100 and 200 turns each, featuring wire thickness ranging from 0.05 to 0.5 mm, have been integrated with the caps of PVC sensor modules measuring 10 mm in height and 17 mm in diameter, using polymeric sheets.

[0023] In yet another aspect of the present invention, a planer or cylindrical substrate has been affixed to the base of the module.

[0024] In still another aspect of the present invention, the magnetic field has been produced by using a simple voltage source that controls current flow passing through the solenoid wire, thereby the strength of the magnetic field has been regulated.DESCRIPTION OF THE DRAWINGS

[0025] The present invention is illustrated in figures 1 to 6 of the drawings accompanying this specification. In the drawings like reference numbers indicate corresponding parts in the various figures.

[0026] Figure 1 represents all the components of the sensor module wherein the substrate coated with sensing material is placed at the core of the module, as per an embodiment herein.

[0027] Figure 2 represents a perspective view of a sensor module with an in-built magnetic field source for generating as well as regulating magnetic field at the core of the electromagnet and the sensor module, as per an embodiment herein.

[0028] Figure 3 (3a, 3b) represents the solenoid and solenoid embedded sensor module, where the direction of current and corresponding magnetic field direction have been illustrated, as per an embodiment herein.

[0029] Figure 4 represents how the strength of the magnetic field depends on the current passing through the coil, as per an embodiment herein.

[0030] Figure 5 (5a, 5b) represents how the magnetic field varies with current in different types of solenoids, as per an embodiment herein.

[0031] Figure 6 (6a-6d) represents the effect of the magnetic field on the gas sensing response of different systems towards individual gases, as per an embodiment herein.

[0032] The referral numerals in the figures refer to 001 - sensor module, 002 - base, 003 - metal pins, 004 - cylindrical sensor substrate, 005 - PVC module cover, 006 - polymeric mesh, 007 - planar sensor substrate, 008 - sensor module with integrated electromagnet, 009 - copper coil using which the electromagnet was prepared, 010 - sensor module cover with in-built electromagnet connected with voltage source for current flow and magnetic field generation .DETAILED DESCRIPTION OF THE INVENTION

[0033] The following description with reference to the drawings are being provided to aid in comprehending the embodiment of the current disclosure and its associated claims. The invention offers an easier route for improving the sensing performance of a chemiresistive gas sensor.

[0034] The present invention provides an improved gas sensor module with an in-built electromagnet and gas detection method thereof comprises sensor module (001), base (002), metal pins (003), cylindrical sensor substrate (004), PVC module cover (005), polymeric mesh (006), planar sensor substrate (007), sensor module with integrated electromagnet (008), copper coil using which the electromagnet was prepared (009),sensor module cover with in-built electromagnet connected with voltage source for current flow and magnetic field generation (010); wherein, the base (002) is made up of a PVC (PolyVinyl Chloride) polymer; wherein, the sensor substrate (004, 007) is placed inside the base with six metallic pins (003) for attaching the sensor.

[0035] In another embodiment, the polymeric cap (PVC) encloses the base with a mesh-like opening at the top of the cap. An integrated solenoid coil with a specific number of turns wound around the PVC-made cylindrical cap of the sensor module using insulated copper wire, further the number of turns vary based on the application of the sensor module. The voltage source generates and varies voltage for the required amount of current generation. The polymeric sheet is wrapped around the entire assembly to stabilize the entire setup.

[0036] In another embodiment, the invention relates to an improved gas sensor module with an in-built electromagnet and gas detection method thereof . The present invention introduces a unit embodiment wherein an electromagnet is seamlessly integrated into a sensor module, resulting in the generation and regulation of a magnetic field at the module's core. This straightforward yet inventive arrangement offers a practical means to enhance sensitivity and expand the detection limits for a variety of sensing materials without perturbing the stability of the sensing system which is a key aspect that distinguishes this invention.

[0037] In accordance with the present invention provides: (i) an electromagnet has been embedded with a PVC-made sensor module, (ii) Electric current has been initiated and adjusted to create and control the magnetic field within the core of the sensor's module, (iii) The response and detection limit of the sensors has been regulated under the influence of a magnetic field while performing sensing experiments using the arrangement, (iv) Improved response values with respect to reported values have been achieved in widely used chemiresistive sensors.

[0038] In one particular embodiment of this disclosure, both the sensor and electromagnet have been integrated in close proximity within the sensor module to ensure that the magnetic field strength is evenly dispersed throughout the sensor's vicinity. Furthermore, even in cases where the field needs to be eliminated, there is no necessity to disassemble thesetup that safeguards against disturbances. A detailed description of each component of the sensor module with an in-built electromagnet has been given below.

[0039] The present invention as illustrated in Figure 1, we have the sensor module (001), which boasts an outer diameter of 17 mm and a height of 10 mm. The sensor module is constructed from PVC and the base (002) of the sensor includes six metal pins (003) for establishing connections. The sensor substrate (004), coated with the sensing material, is affixed to these pins using platinum wire.

[0040] In another embodiment, the entirety of this assembly is enclosed within a PVC module cover (005), which has an open top covered with a 200 pm polymeric mesh (006). This module offers versatility in terms of sensor substrates; it accommodate either a planar (007) or cylindrical (004) substrate design. When employing a cylindrical substrate, the sensor incorporates circular gold electrodes, while the planar substrate variant features interdigitated electrodes. Then sensor module equipped with an integrated electromagnet (008) has been fabricated. In the assembly process, a tightly wound copper coil (009) is subsequently applied around the module's cap, and the assembly is encapsulated within a polymeric sheet, thereby forming a module featuring an integrated solenoid (008). Figures 2 and 3 illustrate the complete setup of the gas sensor module, which includes an electromagnet assembly. This electromagnet comprises a solenoid of copper wire, separately depicted in Figure 3a, measuring 0.2 mm in thickness and the length of the solenoid is 10 mm. Magnetic field (B) is generated within the solenoid core following eq. (1) and (2),

[0041] B= pnl (1)

[0042] B = pnIR2 / 2[R2+z2]3 / 2(2)

[0043] where, p= permeability of the core material, n= number of turns per unit length (N / l), 1= current through the coil, 1= length of the coil, R= radius of the coil, z= the position of the point where the field is being calculated if R is higher than 1 of the coil. Figure 3b shows how the direction of the field at the core of the integrated electromagnet depends on the direction of the current through the coil (010).TABLE 1

[0044] TABLE 1 represents the relationship (011) between magnetic field strength (B), current (I) and number of turns per unit length in the coil (n). The directly proportional relationship between B and I, n further has been justified in Figure 4.

[0045] In another embodiment, the module has been meticulously crafted to facilitate convenient regulation of the magnetic field at the core of the solenoid. However, from the above-mentioned equation, it has been noticed that the field around the coil adjusted in several ways such as varying current, increasing the number of turns in the coil, adjusting module material, and modifying coil length and diameter. In this specific scenario, where the material of the module, coil material, and the dimensions (length and diameter) of the coil remain constant, the regulation of field strength has been achieved through the implementation of the following two methods: (i) Varying Current: The most common method is to change the amount of electric current passing through the solenoid's coil. According to Ampere's Law, the strength of the magnetic field is directly proportional to the current flowing through the coil. Therefore, by increasing or decreasing the current, the magnetic field strength has been tuned, (ii) Changing the Number of Coil Turns: Another way to regulate the magnetic field strength is by altering the number of turns in the coil. Increasing the number of turns while keeping the current constant has resulted in a stronger magnetic field and vice versa.

[0046] This configuration allows for the generation of a wide range of magnetic field strengths (012), (013) in the vicinity of the sensor, as depicted in EXAMPLE 1 and 2 along with Figure 5. Furthermore, altering the material of the module, the coil material, and the thickness of the coil resulted in the production of magnetic fields with different strengths. This aspect is also encompassed within the scope of the present disclosure.

[0047] In another embodiment, to assess the practicality of the configuration, we conducted experiments to evaluate the magnetic field generated by this assembly in conjunction with well-established sensing materials. Notably, the utilization of the magnetic field, as depicted in Figure 6a, has demonstrated enhancements in response value with respect to the previously reported carbon monoxide (CO) sensing performance of both ZnO (014) and copper-doped ZnO (015). Furthermore, Figure 6b illustrates an improved response towards ammonia (NH3) for both tin dioxide (SnOi) (016) and vanadium- doped SnOi (017) compared to prior reports, achieved through the application of an external magnetic field. In Figure 6c, it is evident that the nitrogen dioxide (NO2) response of indium oxide (h Cb) (018) and iron-doped ImCh (019) has exhibited substantial enhancements, with the magnetic field playing a pivotal role. Moreover, the application of the magnetic field generated by the sensor module (Figure 6d) has enabled the detection of very low concentrations (500 ppb) of NO2 in the iron-doped ImOs-bascd gas sensor (020), which is previously undetectable by the same sensor (020). The capacity for improving gas sensing responses through magnetic field application is observed across a wide range of gas concentrations, as elucidated in Figure 6d. Comprehensive details and discussions of these findings are provided in EXAMPLES 2, 3, and 4. Further, the applicability and effectiveness of this magnetic field-based sensing approach towards various gas concentration scenarios (021) have been substantiated in Figure 6d.EXAMPLES

[0048] The following examples are given by way of illustration of the working of the invention in actual practice and should not be construed to limit the scope of the present invention in any way.EXAMPLE-1

[0049] In another embodiment, a 10 mm-long solenoid has been crafted using copper wire with a diameter of 0.05 mm, and it's been integrated with the gas sensor module having a diameter of 17 mm. The solenoid consists of 200 turns. Subsequently, the entire assembly has been encased within a polymeric sheet to securely integrate the coil into the module. Figure 5a visually illustrates how applying a voltage through the coil generates a magnetic field.

[0050] Due to the reduced thickness of the copper wire employed in this solenoid compared to the one mentioned earlier, a lesser amount of current flows through this coil. Consequently, in order to generate a magnetic field of comparable strength, the number of turns in the coil has been increased.EXAMPLE-2

[0051] In another embodiment, a second 10 mm-long solenoid has been manufactured using copper wire with a diameter of 0.11 mm, and it has been incorporated into the gas sensor module, which itself has a 17 mm diameter. This solenoid is comprised of 200 turns. Following this, the entire assembly has been enclosed within a polymeric sheet to ensure the secure integration of the coil into the module. Figure 5b provides a visual representation of the magnetic field generated when voltage is applied to the coil.

[0052] In this case, we employed 200 turns of copper wire with a thickness of 0.11 mm. Due to the larger cross-sectional area of the wire compared to the previous example, we required a lower voltage input to generate a magnetic field of similar strength.EXAMPLE-3

[0053] The utilization of ZnO and Cu-doped ZnO for chemiresistive CO sensing has previously been documented. We conducted gas sensing experiments using chemiresistive sensors based on pure ZnO and Cu-doped ZnO, which are integrated into gas sensor modules with in-built electromagnets. We reproduced the results and improved the sensing capabilities of both sensors by applying a magnetic field. Figure 6a illustrates the enhancement in the 30 ppm CO sensing performance when influenced by the magnetic field generated by the electromagnet embedded in the sensor module.EXAMPLE-4

[0054] In another embodiment, we conducted gas sensing experiments utilizing chemiresistive sensors based on pure SnCh and V-doped SnCh, which are integrated into gas sensor modules with in-built electromagnets. Both of these sensors have already exhibited a response to NH3. We reproduced the results and further improved the sensing response of both sensors with respect to the reported value by applying a magnetic field using the present set-up. Figure 6b illustrates the enhancement in the NH3 sensing response of SnOi and V-doped SnCh when influenced by the magnetic field generated by the electromagnet embedded in the sensor module.EXAMPLE-5

[0055] In another embodiment, I Ch and Fe-doped I Ch sensors on pure are placed into gas sensor modules with in-built electromagnets. The sensing response of both sensors has been increased by applying a magnetic field. Figure 6c illustrates the enhancement in the NO2 sensing response of I Ch and Fe-doped I Ch when influenced by the magnetic field generated by the electromagnet embedded in the sensor module. Being ferromagnetic material, the highest change in chemiresistive response has been observed by Fe-doped h Ch towards NO2. Figure 6d demonstrates that the magnetic field produced by the electromagnet- sensor module assembly operates effectively across a broad range of gas concentrations and enhance the sensor's detection ability.

[0056] In another embodiment, the present invention provides an improved gas sensor module with an in-built electromagnet and gas detection method thereof on which comprises a chemiresistive gas sensor, more specifically the module of chemiresistive gas sensor and an electromagnet attached to the cap of the module and the sensing module described herein features an innovative design of electromagnet integrated sensor module that seamlessly produce and regulate magnetic field around gas sensors during gas sensing experiment via voltage source that influences sensitivity of chemiresistive gas sensors placed at the module’s core. In another aspect of the invention, the sensor module comprises a PVC-made module base wherein six metallic pins are affixed for attaching sensors and the base is enclosed by a polymeric cap with an opening at the top using a polymeric mess. Then a solenoid around the PVC-made cylindrical cap of the sensor module using insulated copper wire has been integrated. To ensure the stability of the entire setup, a polymeric sheet has been wrapped around the entire assembly.

[0057] In another embodiment of the invention, the electromagnet source incorporated sensing module is configured in such a way so that the solenoid produce a uniform magnetic field around the sensor module. The voltage source generates charge flow through the enameled copper coil-based solenoid. As current passes through the solenoid, it creates a magnetic field within the solenoid’s core according to Ampere’s law. In a solenoid, electronic charges flow through the coil, generating a magnetic field directed perpendicular to the plane of charge flow. Nevertheless, the combined impact of the current flowing through the wire and the number of turns within the solenoid leads to an accumulative effect, producing a robust and fairly uniform magnetic field within the core of the solenoid. Therefore, it is feasible to adjust magnetic field strength at a specific point in the vicinity of the sensor by controlling magnetic flux density through the manipulation of both the number of turns in the coil and the current passing through it, achieved by varying the voltage.

[0058] In an embodiment of the present disclosure, enhancement in the sensing response of different chemiresistive gas sensors towards their target gases due to the magnetic field has been observed in a more straightforward manner.

[0059] In another embodiment of the present invention, this sensor module comprises a PVC- made module base wherein six metallic pins are affixed for attaching sensors and the base is enclosed by a polymeric cap with an opening at the top using a polymeric mess.

[0060] In another embodiment of the present invention, solenoids, comprising enameled copper coils with 100 and 200 turns each, featuring wire thickness ranging from 0.05 to 0.5 mm, have been integrated with the caps of PVC sensor modules measuring 10 mm in height and 17 mm in diameter, using polymeric sheets.

[0061] In another embodiment of the present invention, a planer or cylindrical substrate has been affixed to the base of the module.

[0062] In another embodiment of the present invention, a magnetic field has been produced by using a simple voltage source that controls current flow passing through the solenoid wire, thereby the strength of the magnetic field has been regulated.

[0063] In another embodiment of the present invention, the improved chemiresistive gas sensor module with embedded electromagnet has been developed to facilitate magnetic field- induced chemiresistive gas sensing. This six-metal pin-headed PVC-made cylindrical sensor module features a round base with space for placing a gas sensor and a cap with an in-built electromagnet, coupled like a solenoid made of insulated copper wire. This arrangement generate a tunable magnetic field on the gas sensor welded to the pins inside the cylindrical module. Charge flow through the solenoid produces homogeneous magnetic field flux directed perpendicularly to the gas sensor. The magnetic field strength precisely tuned by regulating the charge flow through the solenoid using a voltage source. The generated field will help to achieve higher sensing responses by chemiresistive sensing materials. The use of a magnetic field in this way often generate low-concentration gas detection ability in a sensor, which is otherwise not detectable by the same.ADVANTAGES OF THE INVENTION

[0064] The main advantages of the present invention are:

[0065] This disclosure has focused on a single embodiment involving an electromagnet- attached sensor module, it's worth noting that we can integrate the magnetic field source and the sensor module into a single unit.

[0066] Generate and regulate the magnetic field around the sensor by changing the current and number of turns in the coil.

[0067] Integrated device simplifies the process of conducting gas sensing measurements under the influence of a magnetic field, eliminating the need for ferrite rings and their positioning required to manipulate flux through the sensor or any other external field source.

[0068] While this current disclosure has been presented and explained in connection with different embodiments, individuals with expertise in the field will recognize that adjustments in structure and specifics are possible without deviating from the fundamental principles and extent of this disclosure, as defined by the attached claims and their equivalents.

Claims

WE CLAIM:

1. An improved gas sensor module with in-built electromagnet and gas detection method thereof comprises base (002), metal pins (003), cylindrical substrate (004), PVC module cover (005), polymeric mesh (006), planar substrate (007), sensor module with integrated electromagnet (008), copper coil using which the electromagnet was prepared (009), sensor module cover with in-built electromagnet connected with voltage source for current flow and magnetic field generation (010) ; wherein, the base (002) is made up of a PVC (Poly Vinyl Chloride) polymer; wherein, the sensor chip (004) placed inside the base with six metallic pins (003) for attaching sensor; wherein, the polymeric cap (PVC) for enclosing the base with mesh like opening at top of the cap; wherein, an integrated solenoid coil with specific number of turns wound around the PVC made cylindrical cap of the sensor module using insulated copper wire, further the number of turns vary based on the application of the sensor module; wherein, the voltage source to generate and vary voltage for required amount of current generation; wherein, the polymeric sheet wrapped around the entire assembly to stabilise the entire setup; wherein, the module of chemiresistive gas sensor and an electromagnet attached to the cap of the module; wherein, the sensing module produce and regulate magnetic field around gas sensors during gas sensing experiment via voltage source that influences sensitivity of chemiresistive gas sensors placed at the module’s core; wherein the method of gas detection comprises a plurality of steps.

2. The improved gas sensor module with in-built electromagnet as claimed in claim 1, utilizes the cap of the module for placing the solenoid as an electromagnet; alternatively, the electromagnet placed on other parts of the module or somewhere near the module.

3. The improved gas sensor module with in-built electromagnet as claimed in claim 1, utilizes PVC as the module material which has permeability similar to free space; wherein, material with different permeability for the module used and will result in different magnetic field strength.

4. The improved gas sensor module with in-built electromagnet as claimed in claim 1, employs a solenoid made from enameled copper wire as the magnetic field source;wherein other insulated metallic wires selected from the group consisting of silver, gold, or aluminum to construct the solenoid.

5. The improved gas sensor module with in-built electromagnet as claimed in claim 1, claim 4, wherein the thickness of the copper wire falls in the sub millimetre range (0.05- 0.5 mm) thereby tuning the thickness of solenoid wire, current flow as well as the magnetic field adjusted; wherein, Solenoid consists 100 or 200 turns of copper wire wherein the number of turns directly proportional to the field it produces at its core, further the number of turns varied to obtain desired magnetic field strength.

6. The improved gas sensor module with in-built electromagnet as claimed in claim 1, claim 5 wherein the dimension of the solenoid used in the sensor module with in-built electromagnet has been chosen similar to the module dimension, thus change in module dimension will help to change the dimension of the solenoid as well as a number of turns, thereby will help to achieve magnetic field having different strength.

7. The improved gas sensor module with in-built electromagnet as claimed in claim 1, wherein, the current passing around the sensor module with an in-built electromagnet has been varied using voltage sources ranging from 0V to 10V and consequently varying the magnetic field strengths.

8. The improved gas sensor module with in-built electromagnet as claimed in claim 1, claim 8 wherein, Current flow as well as magnetic field produced using voltage source regulated up to 21V using a simple voltage source.

9. The improved gas sensor module with in-built electromagnet as claimed in claim 1, wherein, Magnetic field produced at the core of the electromagnet integrated sensor module helped to improve chemiresistive response of sensing materials; wherein higher response with respect to previous values has been achieved using pure and doped ZnO, SnOi and IroCh based sensors.

10. The method of gas detection as claimed in claim 1, comprises the steps of: a) allowing gas to flow through the gas sensor module wound with solenoid; b) the sensor modulecreates a magnetic field within the solenoid’s core (which is wound around the sensor module) by passing current (current generated by supplying voltage from voltage source); c) sensor module adjust the current in the solenoid for on-demand and on-spot magnetic field variation to improve the gas sensitivity of the sensing material; d) using the generated magnetic field, the gas sensor detect the concentrations of different gases at very low concentration.

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