Method, apparatus, system and medium for fabricating gas sensing chip for litchi quality characteristics

Abstract

This application discloses a method, apparatus, system, and medium for fabricating a litchi quality characteristic gas sensing chip. The method includes: oxidizing a tin substrate under predetermined oxidation conditions to form a thin tin oxide layer on the surface of the tin substrate, obtaining a tin oxide composite substrate; performing Pt atomic deposition on the tin oxide composite substrate to obtain a Pt-modified composite substrate; peeling off the Pt-modified composite substrate to obtain Pt-modified tin oxide two-dimensional nanosheets; etching the chip substrate using deep reactive ion etching (DRIE) to obtain a micro-hotplate structure; and transferring the Pt-modified tin oxide two-dimensional nanosheets to the micro-hotplate electrode area of ​​the micro-hotplate structure to obtain the litchi quality characteristic gas sensing chip. This method improves the detection sensitivity and response speed of litchi quality characteristic gases by fabricating Pt-modified tin oxide two-dimensional nanosheets and integrating them into a micro-hotplate structure, enabling rapid sensing of litchi quality status.

Description

Technical Field

[0001] This application relates to the field of sensor technology, and in particular to a method, apparatus, system and medium for preparing a gas sensing chip for lychee quality characteristics. Background Technology

[0002] With the continuous development of cold chain storage and transportation technology for fruits and vegetables, monitoring the quality status of perishable fruits such as lychees has become a crucial step in ensuring food safety, reducing storage and transportation losses, and extending shelf life. Lychees are prone to ripening, spoilage, or decay during storage and transportation, and these quality changes are accompanied by the release of characteristic volatile gases, such as 2,3-butanediol. Therefore, identifying lychee quality changes through gas detection methods has significant application value.

[0003] However, in practical applications, the volatile gas composition in fruit and vegetable storage and transportation environments is complex, with significant background gas interference. Traditional gas sensors typically suffer from insufficient selectivity, low sensitivity, and poor response stability, making it difficult to accurately identify the characteristic gases produced during lychee spoilage in complex gas environments. Especially in cold chain storage and transportation scenarios, detection equipment also needs to meet the requirements of miniaturization, low power consumption, and integration. Existing sensor structures and material systems are insufficient to meet the demands for continuous, rapid, and highly selective detection. Summary of the Invention

[0004] This application provides a method, apparatus, system, and medium for preparing a litchi quality characteristic gas sensing chip. By preparing Pt-modified tin oxide two-dimensional nanosheets and integrating them into a micro-hot plate structure, the detection sensitivity and response speed of litchi quality characteristic gases are improved, making it suitable for litchi storage, transportation, and quality monitoring scenarios.

[0005] In a first aspect, this application provides a method for fabricating a gas sensing chip for litchi quality characteristics, comprising: Under set oxidation conditions, a tin substrate is oxidized to form a thin layer of tin oxide on the surface of the tin substrate, resulting in a tin oxide composite substrate. The tin oxide composite substrate is subjected to Pt atomic deposition treatment to form atomically dispersed Pt catalytic sites on the surface of the tin oxide thin layer, thereby obtaining a Pt modified composite substrate; The Pt-modified composite substrate was subjected to a peeling process to obtain Pt-modified tin oxide two-dimensional nanosheets; The chip substrate was etched using deep reactive ion etching (DRIE) to obtain the micro hot plate structure. The Pt-modified tin oxide two-dimensional nanosheets were transferred to the micro-hot plate electrode area of ​​the micro-hot plate structure to obtain a litchi quality characteristic gas sensing chip.

[0006] Secondly, this application provides a device for fabricating a gas sensing chip for lychee quality characteristics, comprising: An oxidation module is configured to oxidize a tin substrate under set oxidation conditions, thereby forming a thin layer of tin oxide on the surface of the tin substrate to obtain a tin oxide composite substrate. A deposition module is configured to perform Pt atomic deposition on the tin oxide composite substrate to form atomically dispersed Pt catalytic sites on the surface of the tin oxide thin layer, thereby obtaining a Pt-modified composite substrate. The stripping module is configured to strip the Pt-modified composite substrate to obtain Pt-modified tin oxide two-dimensional nanosheets. The etching module is configured to use deep reactive ion etching (DRIE) to etch the chip substrate to obtain a micro hot plate structure. The transfer module is configured to transfer the Pt-modified tin oxide two-dimensional nanosheets to the micro-hot plate electrode area of ​​the micro-hot plate structure to obtain a litchi quality characteristic gas sensing chip.

[0007] Thirdly, this application provides a system for fabricating a gas sensing chip for litchi quality characteristics, comprising: One or more processors; The memory stores one or more programs that, when executed by the one or more processors, cause the one or more processors to drive the litchi quality characteristic gas sensing chip fabrication apparatus as described in the second aspect.

[0008] Fourthly, this application provides a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to drive the litchi quality characteristic gas sensing chip preparation apparatus as described in the second aspect.

[0009] In this application, a tin oxide thin layer is formed by oxidizing a tin substrate, and atomically dispersed Pt catalytic sites are deposited on the surface of the tin oxide thin layer to obtain a tin oxide composite structure with catalytic modification effect. Subsequently, the Pt-modified composite substrate is exfoliated to obtain Pt-modified tin oxide two-dimensional nanosheets, which are then transferred to a micro-hotplate electrode region formed by deep reactive ion etching to obtain a litchi quality characteristic gas sensing chip. This method can improve the chip's detection sensitivity, response speed, and integration level for litchi quality characteristic gases. Attached Figure Description

[0010] Figure 1 This is a flowchart of a method for fabricating a gas sensing chip for lychee quality characteristics provided in an embodiment of this application; Figure 2 This is a flowchart of the method for preparing a tin oxide composite substrate provided in the embodiments of this application; Figure 3 This is a flowchart of the method for preparing the micro hot plate structure provided in the embodiments of this application; Figure 4 This is a flowchart of the litchi quality characteristic gas sensing chip transfer method provided in the embodiments of this application; Figure 5 This is a flowchart of the method for verifying the gas sensing chip for lychee quality characteristics provided in this application embodiment; Figure 6 This is a schematic diagram of the structure of the litchi quality characteristic gas sensing chip preparation device provided in the embodiments of this application; Figure 7 This is a schematic diagram of the structure of a gas sensing chip fabrication system for lychee quality characteristics provided in an embodiment of this application. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application will be described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely for explaining this application and not for limiting it. It should also be noted that, for ease of description, only the parts relevant to this application are shown in the drawings, not all of them. Before discussing exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe operations (or steps) as being processed sequentially, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. A process can be terminated when its operation is completed, but it may also have additional steps not included in the drawings. A process can correspond to a method, function, procedure, subroutine, subroutine, etc.

[0012] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0013] In the storage, transportation, and cold chain distribution of fruits and vegetables, quality monitoring of perishable fruits such as lychees is crucial for ensuring food safety and extending shelf life. Lychees release characteristic gases such as 2,3-butanediol during ripening or spoilage, and detecting these gases can help determine the quality status of the lychees. However, the composition of volatile gases in the fruit and vegetable storage and transportation environment is complex, and traditional gas sensors lack sufficient selectivity and sensitivity, making it difficult to accurately identify the characteristic gases of lychee spoilage.

[0014] Existing technologies typically improve detection performance by optimizing sensitive materials, improving sensor structures, or introducing signal processing algorithms. However, they still suffer from problems such as insufficient material adsorption capacity, complex sensor structures, and low levels of miniaturization and integration, making it difficult to meet the high selectivity, low power consumption, and chip-level detection requirements in fruit and vegetable cold chain scenarios. Therefore, there is an urgent need to provide a micro gas sensing chip fabrication scheme suitable for detecting gas characteristics of lychee quality.

[0015] Figure 1 This is a flowchart illustrating a method for fabricating a gas sensing chip for lychee quality characteristics, as provided in an embodiment of this application. (Reference) Figure 1 The specific preparation method of the litchi quality characteristic gas sensing chip includes: S110. Under the set oxidation conditions, the tin substrate is oxidized to form a thin layer of tin oxide on the surface of the tin substrate, thereby obtaining a tin oxide composite substrate.

[0016] The tin substrate can be a sheet substrate, foil substrate, block substrate or strip substrate made of tin material. The oxidation conditions can include oxidation temperature, oxidation time, oxygen concentration, gas flow rate and heating rate. The tin oxide thin layer can be a tin dioxide layer or a tin oxide-containing surface oxide layer formed on the surface of the tin substrate. The tin oxide composite substrate can be a composite structure composed of a tin substrate and a surface tin oxide thin layer.

[0017] In one embodiment, the oxidation process for the tin substrate can be as follows: placing the tin substrate in an oxidation furnace, introducing oxygen-containing gas into the oxidation furnace, heating the oxidation furnace to a set oxidation temperature, and maintaining the set oxidation temperature for a preset oxidation time, so that the tin atoms on the surface of the tin substrate react with oxygen to generate a thin layer of tin oxide on the surface of the tin substrate.

[0018] Through the above steps, a continuous tin oxide thin layer can be formed on the surface of a tin metal substrate to obtain a tin oxide composite substrate, which provides a basic carrier for subsequent material deposition, interface modification or device fabrication on the tin oxide composite substrate.

[0019] Optionally, Figure 2 This is a flowchart of the method for preparing a tin oxide composite substrate provided in the embodiments of this application. (Reference) Figure 2The specific preparation method of this tin oxide composite substrate includes: S1101. A tin substrate is placed in an atmosphere furnace, and a mixture of oxygen and argon is introduced into the atmosphere furnace, wherein the volume fraction of oxygen in the mixture is 20% to 30%.

[0020] The atmosphere furnace can be a tube furnace, a box furnace, or other heat treatment equipment with adjustable gas composition and temperature to provide a controlled oxidation environment. The mixed gas can be an oxidation atmosphere formed by mixing oxygen and argon in a set ratio. Oxygen is used to react with tin atoms on the surface of the tin substrate, and argon is used to dilute the oxygen and stabilize the reaction environment inside the atmosphere furnace.

[0021] In one embodiment, the mixed gas can be introduced by placing a tin substrate in the sample loading area of ​​an atmosphere furnace, turning off the atmosphere furnace and turning on the gas inlet pipe, controlling the gas inlet flow rates of oxygen and argon respectively through a mass flow controller, so that the volume fraction of oxygen in the mixed gas is maintained in the range of 20% to 30%, and the mixed gas continuously flows over the surface of the tin substrate.

[0022] Through the above steps, an oxidizing atmosphere with controllable oxygen content can be provided for the tin substrate in the atmosphere furnace. This avoids insufficient tin oxide film formation due to excessively low oxygen concentration, and also avoids excessively high oxygen concentration leading to excessively fast oxidation rate or uneven film structure, thus providing atmospheric conditions for the subsequent formation of a stable tin oxide film.

[0023] S1102. The oxidation temperature of the atmosphere furnace is controlled at 400°C to 500°C.

[0024] The oxidation temperature can be the heating temperature used in the atmosphere furnace to cause the oxidation reaction on the surface of the tin substrate. Controlling the oxidation temperature between 400°C and 500°C allows the tin atoms on the surface of the tin substrate to react fully with the oxygen in the mixed gas, forming a relatively continuous tin oxide thin layer on the surface of the tin substrate.

[0025] In one embodiment, the oxidation temperature can be controlled by: starting the heating program of the atmosphere furnace, raising the furnace temperature to the range of 400°C to 500°C according to a preset heating rate, and detecting the furnace temperature in real time through a temperature sensor; increasing the heating power when the furnace temperature is lower than the set oxidation temperature, and reducing the heating power when the furnace temperature is higher than the set oxidation temperature, so that the furnace temperature is kept near the set oxidation temperature.

[0026] The above steps provide stable heat treatment conditions for the oxidation of the tin substrate surface, avoiding insufficient oxidation due to excessively low temperatures and excessively high temperatures that result in an excessively thick tin oxide layer or a rough structure, thus providing a temperature basis for obtaining the tin oxide composite substrate in the future.

[0027] S1103. Control the oxidation time to 2 to 3 hours to form a thin layer of tin oxide on the surface of the tin substrate, thereby obtaining a tin oxide composite substrate.

[0028] Among them, oxidation time can be the time for the tin substrate to react continuously under a set oxidation temperature and mixed gas environment, tin oxide thin layer can be the surface oxide layer formed after tin atoms on the surface of the tin substrate react with oxygen, and tin oxide composite substrate can be a composite substrate composed of a tin substrate and a tin oxide thin layer located on the surface of the tin substrate.

[0029] In one embodiment, the oxidation time can be controlled by starting to record the oxidation time after the furnace temperature has risen to and stabilized within the range of 400°C to 500°C, allowing the tin substrate to be continuously oxidized in a mixture of oxygen and argon for 2 to 3 hours. During the oxidation process, the mixed gas is continuously introduced into the furnace to ensure a stable oxygen source on the surface of the tin substrate.

[0030] By following the steps described above, the formation time of the tin oxide thin layer on the surface of the tin substrate can be controlled, so that the tin oxide thin layer has good continuity and thickness stability. This avoids the tin oxide thin layer being incomplete due to too short an oxidation time, and also avoids the tin oxide thin layer being too thick due to too long an oxidation time, thus providing a stable tin oxide surface for subsequent Pt atom deposition processing.

[0031] S120. The tin oxide composite substrate is subjected to Pt atomic deposition treatment to form atomically dispersed Pt catalytic sites on the surface of the tin oxide thin layer, thereby obtaining a Pt modified composite substrate.

[0032] Among them, Pt atomic deposition treatment can be a process of loading platinum element onto the surface of tin oxide thin film through atomic layer deposition; atomically dispersed Pt catalytic sites can be platinum active sites distributed on the surface of tin oxide thin film in the form of single atoms, sub-nano clusters or highly dispersed states; Pt modified composite substrate can be a composite structure composed of a metallic tin substrate, tin oxide thin film and surface Pt catalytic sites.

[0033] In one embodiment, the formation of Pt catalytic sites can be achieved by placing a tin oxide composite substrate in an atomic layer deposition apparatus, alternately introducing Pt precursor gas and reactant gas into the reaction chamber, causing the Pt precursor to adsorb and react on the surface of the tin oxide thin layer, and controlling the number of deposition cycles to deposit Pt in an atomically dispersed state on the surface of the tin oxide thin layer, thereby forming Pt catalytic sites.

[0034] Through the above steps, atomically dispersed Pt catalytic sites can be formed on the surface of tin oxide thin film, resulting in a Pt-modified composite substrate, which provides an active interface for subsequent promotion of the adsorption, activation and resistance response changes of litchi quality characteristic gases on the tin oxide surface.

[0035] S130. The Pt-modified composite substrate is subjected to a peeling process to obtain Pt-modified tin oxide two-dimensional nanosheets.

[0036] The stripping process can be a process of separating the Pt-modified tin oxide layer from the surface of the tin metal substrate in the Pt-modified composite substrate. The Pt-modified tin oxide two-dimensional nanosheets can be two-dimensional sheet structures of tin oxide with atomically dispersed Pt catalytic sites on their surface.

[0037] In one embodiment, the stripping process can be performed by: placing the Pt-modified composite substrate in a stripping solution, allowing the stripping solution to enter the interface region between the tin oxide thin layer and the tin metal substrate, thereby weakening the bonding force between the tin oxide thin layer and the tin metal substrate; subsequently, subjecting the Pt-modified composite substrate to ultrasonic treatment or mechanical oscillation treatment, causing the tin oxide thin layer with Pt catalytic sites loaded on its surface to detach from the surface of the tin metal substrate, thereby obtaining Pt-modified tin oxide two-dimensional nanosheets.

[0038] Through the above steps, a thin layer of tin oxide loaded with Pt catalytic sites can be peeled off from the surface of a tin metal substrate to form Pt-modified tin oxide two-dimensional nanosheets, providing sheet-like functional materials for the subsequent preparation of catalytic electrodes, sensor sensitive layers or two-dimensional catalytic materials.

[0039] S140. The chip substrate is etched using a deep reactive ion etching process to obtain a micro hot plate structure.

[0040] The chip substrate can be a silicon substrate, a silicon-on-insulator substrate, or other semiconductor substrates suitable for microelectromechanical processing. The deep reactive ion etching process can be a process of deep trench etching of the chip substrate using alternating passivation and etching methods. The micro hot plate structure can be a miniature heating carrier with a suspended film layer, support beam, heat insulation groove, or back cavity structure.

[0041] In one embodiment, the micro hot plate structure can be prepared by: forming an etching mask layer on the surface of a chip substrate and creating an etching window corresponding to the micro hot plate structure in the etching mask layer; placing the chip substrate with the etching window into a deep reactive ion etching apparatus, and alternately introducing etching gas and passivation gas into the reaction chamber, so that the etching gas etches along the etching window into the chip substrate to form a heat insulation groove, a release cavity or a support structure, thereby obtaining the micro hot plate structure.

[0042] Through the above steps, a micro-hotplate structure with good thermal isolation effect can be formed in the chip substrate, providing a structural basis for the subsequent fabrication of heating electrodes, temperature measuring electrodes, and Pt-modified tin oxide two-dimensional nanosheet sensitive layers on the micro-hotplate structure.

[0043] Optionally, Figure 3This is a flowchart illustrating the fabrication method of the micro-hotplate structure provided in this application embodiment. The first and second surfaces are arranged opposite each other. The cantilever beam micro-hotplate structure has a length of 500 μm, a width of 100 μm, a thickness of 10 μm, and a cup-shaped insulating cavity depth of 200 μm. (Reference) Figure 3 The specific preparation method of this micro-hot plate structure includes: S1401. Perform deep reactive ion etching on the first surface of the chip substrate to form a cantilever beam micro-hot plate structure on the first surface.

[0044] The first surface can be a side surface used to form the micro hot plate structure and electrode structure. The deep reactive ion etching process can be a micromachining process that uses alternating etching gas and passivation gas to etch the chip substrate with a high aspect ratio. The cantilever beam micro hot plate structure can be a micro heating structure composed of a cantilever beam, a heating support area and a heat insulation release area.

[0045] In one embodiment, the cantilever beam micro-hotplate structure can be formed by: preparing an etching mask layer on the first surface of the chip substrate and forming an etching window corresponding to the cantilever beam micro-hotplate structure in the etching mask layer; placing the chip substrate with the etching window into a deep reactive ion etching apparatus, and alternately introducing etching gas and passivation gas into the apparatus cavity, so that the etching gas etches into the chip substrate along the etching window, thereby forming a cantilever beam micro-hotplate structure on the first surface.

[0046] Through the above steps, a cantilever beam micro-hot plate structure with supporting and heat-insulating functions can be formed on the first surface of the chip substrate, providing a structural basis for the subsequent fabrication of electrode areas and transfer of Pt-modified tin oxide two-dimensional nanosheets on the micro-hot plate structure.

[0047] S1402. Deep reactive ion etching is performed on the second surface of the chip substrate to form a cup-shaped heat-insulating cavity corresponding to the cantilever beam micro-hot plate structure, thereby obtaining the micro-hot plate structure.

[0048] The second surface can be a side surface opposite to the first surface, and the cup-shaped heat insulation cavity can be a recessed cavity structure formed by etching from the second surface toward the first surface. The cup-shaped heat insulation cavity is correspondingly set with the cantilever beam micro-hot plate structure to reduce the conduction of heat to the chip substrate body area when the micro-hot plate is working.

[0049] In one embodiment, the cup-shaped heat-insulating cavity can be formed by: flipping the chip substrate so that the second surface faces the etching direction of the deep reactive ion etching (DRIE) apparatus; preparing a back-side etching mask layer on the second surface and forming a back-side etching window in the back-side etching mask layer that corresponds to the position of the cantilever beam micro-hot plate structure; placing the chip substrate in the DIE apparatus and performing DIE etching on the chip substrate along the back-side etching window to form a cup-shaped heat-insulating cavity extending from the first surface on the second surface.

[0050] Through the above steps, a cup-shaped heat-insulating cavity corresponding to the cantilever beam micro-hot plate structure can be formed on the second surface of the chip substrate, reducing heat loss during micro-hot plate operation, improving heating efficiency and temperature response speed in the micro-hot plate area, and providing a thermal isolation structure basis for the subsequent formation of a gas sensing chip for lychee quality characteristics.

[0051] S150. The Pt-modified tin oxide two-dimensional nanosheets are transferred to the micro-hot plate electrode area of ​​the micro-hot plate structure to obtain the litchi quality characteristic gas sensing chip.

[0052] Among them, the micro hot plate electrode area can be the area in the micro hot plate structure used to carry the sensitive material and corresponding to the heating electrode or test electrode. The Pt modified tin oxide two-dimensional nanosheet can be used as a sensitive material that responds to the quality characteristic gases of lychee. The quality characteristic gases of lychee can include alcohols, aldehydes, esters or sulfur-containing volatile gases released during the ripening, storage or deterioration of lychee. The lychee quality characteristic gas sensing chip can be a miniature gas sensing chip used to detect volatile gases related to lychee quality.

[0053] In one embodiment, the method for preparing the litchi quality characteristic gas sensing chip can be as follows: Pt-modified tin oxide two-dimensional nanosheets are dispersed in a dispersion medium to obtain a nanosheet dispersion; the nanosheet dispersion is transferred to the micro-hot plate electrode area of ​​the micro-hot plate structure, so that the Pt-modified tin oxide two-dimensional nanosheets cover the surface of the micro-hot plate electrode area to obtain the litchi quality characteristic gas sensing chip.

[0054] Through the above steps, Pt-modified tin oxide two-dimensional nanosheets can be integrated into the electrode area of ​​the micro-hot plate structure to form a litchi quality characteristic gas sensing chip with heating regulation and gas response capabilities, providing a sensor basis for subsequent detection of characteristic gases released during litchi quality changes.

[0055] Optionally, Figure 4 This is a flowchart of the litchi quality characteristic gas sensing chip transfer method provided in this application embodiment. (Reference) Figure 4 The specific methods for transferring the gas sensing chip for lychee quality characteristics include: S1501. The Pt-modified tin oxide two-dimensional nanosheets are attached to the transfer end of the transfer equipment, and the transfer temperature of the transfer equipment is set to 80°C and the transfer pressure of the transfer equipment is set to 0.1MPa.

[0056] The transfer equipment can be a micro-transfer equipment, hot-press transfer equipment, or precision mounting equipment used to transfer two-dimensional nanosheets from a temporary support position to the micro-hot plate electrode area. The transfer end can be the end structure in the transfer equipment used to adsorb, support, or contact the Pt-modified tin oxide two-dimensional nanosheets. The transfer temperature can be the heating temperature applied to the transfer end or support platform during the transfer process. The transfer pressure can be the pressure applied when the transfer end contacts the target transfer area.

[0057] Through the above steps, Pt-modified tin oxide two-dimensional nanosheets can be stably supported on the transfer end of the transfer equipment, and the temperature and pressure conditions can be provided for the subsequent transfer of the two-dimensional nanosheets to the micro hot plate electrode area.

[0058] S1502. Apply a 5V voltage to the positioning electrode of the micro-hot plate structure to form a positioning electric field between the Pt modified tin oxide two-dimensional nanosheet and the micro-hot plate electrode of the micro-hot plate structure.

[0059] The positioning electrode can be a positioning auxiliary electrode set in the electrode area of ​​the micro hot plate, and the positioning electric field can be an electric field formed between the micro hot plate electrode and the Pt modified tin oxide two-dimensional nanosheet, which is used to guide the Pt modified tin oxide two-dimensional nanosheet to attach to the micro hot plate electrode area.

[0060] In one embodiment, the positioning electric field can be formed by: moving the transfer end with the Pt-modified tin oxide two-dimensional nanosheet attached to it above the micro-hot plate electrode area of ​​the micro-hot plate structure, so that the Pt-modified tin oxide two-dimensional nanosheet and the micro-hot plate electrode area maintain a preset distance; then applying a 5V voltage to the electrode of the micro-hot plate structure to form an electric field distribution near the micro-hot plate electrode area, and causing the Pt-modified tin oxide two-dimensional nanosheet to be oriented and attached to the micro-hot plate electrode area under the action of the electric field.

[0061] Through the above steps, the positioning electric field generated by the micro-hot plate electrode can be used to assist the positioning of Pt-modified tin oxide two-dimensional nanosheets to the micro-hot plate electrode region, thereby improving the transfer accuracy and coverage stability of the two-dimensional nanosheets in the micro-hot plate electrode region.

[0062] S1503. Press the Pt-modified tin oxide two-dimensional nanosheets onto the micro-hot plate electrode region of the micro-hot plate structure, so that the Pt-modified tin oxide two-dimensional nanosheets are positioned and attached to the micro-hot plate electrode region under the action of the positioning electric field, thereby obtaining the litchi quality characteristic gas sensing chip.

[0063] The electrode region of the micro-hot plate can be the area in the micro-hot plate structure used to support the sensitive material and form an electrical connection with the test electrode.

[0064] In one embodiment, the press-on transfer method may be as follows: the transfer end with the Pt-modified tin oxide two-dimensional nanosheet attached is moved above the micro-hot plate electrode area, and the Pt-modified tin oxide two-dimensional nanosheet is aligned with the micro-hot plate electrode area; then the transfer end is controlled to descend towards the micro-hot plate electrode area, so that the Pt-modified tin oxide two-dimensional nanosheet contacts the micro-hot plate electrode area under a transfer pressure of 0.1 MPa, and is maintained at a transfer temperature of 80°C for a preset time, so that the Pt-modified tin oxide two-dimensional nanosheet is stably attached to the surface of the micro-hot plate electrode area.

[0065] Through the above steps, Pt-modified tin oxide two-dimensional nanosheets can be accurately transferred and fixed on the electrode area of ​​the micro hot plate, so that the two-dimensional nanosheets and the micro hot plate electrode can form a stable contact, thus obtaining a litchi quality characteristic gas sensing chip for detecting litchi quality characteristic gases.

[0066] Optionally, Figure 5 This is a flowchart of the litchi quality characteristic gas sensing chip verification method provided in this application embodiment. (Reference) Figure 5 The specific verification method for the gas sensing chip for lychee quality characteristics includes: S15031. Press the Pt-modified tin oxide two-dimensional nanosheets onto the micro-hot plate electrode region of the micro-hot plate structure, so that the Pt-modified tin oxide two-dimensional nanosheets are positioned and attached to the micro-hot plate electrode region under the action of the positioning electric field, thereby obtaining the gas sensing chip of the feature to be verified.

[0067] Among them, the feature gas sensing chip to be verified can be an intermediate chip structure that has completed the transfer of Pt-modified tin oxide two-dimensional nanosheets, but has not yet completed the transfer quality verification.

[0068] In one embodiment, the method for forming the gas sensing chip to be verified can be as follows: The transfer end with the attached Pt-modified tin oxide two-dimensional nanosheet is moved above the micro-hotplate electrode area, aligning the Pt-modified tin oxide two-dimensional nanosheet with the micro-hotplate electrode area; the transfer end is controlled to move downwards, pressing the Pt-modified tin oxide two-dimensional nanosheet onto the micro-hotplate electrode area, making the Pt-modified tin oxide two-dimensional nanosheet contact the micro-hotplate electrode area; during the pressing process, a positioning electric field is maintained between the micro-hotplate electrode area and the Pt-modified tin oxide two-dimensional nanosheet, reducing the lateral displacement of the Pt-modified tin oxide two-dimensional nanosheet under the action of the electric field and adhering it to the surface of the micro-hotplate electrode area; after pressing is completed, the transfer end is released, leaving the Pt-modified tin oxide two-dimensional nanosheet in the micro-hotplate electrode area, thus obtaining the gas sensing chip to be verified.

[0069] Through the above steps, Pt-modified tin oxide two-dimensional nanosheets can be positioned and attached to the electrode area of ​​the micro hot plate to form a characteristic gas sensing chip to be verified, providing a verification object for subsequent detection of the coverage area, attachment position and electrode contact state of the two-dimensional nanosheets.

[0070] S15032. Calculate the overlap ratio of the gas sensing chip to be verified, and measure the equivalent contact resistance between the Pt modified tin oxide two-dimensional nanosheet and the micro hot plate electrode area.

[0071] Among them, the press-fit overlap ratio can be the ratio between the coverage area of ​​the Pt-modified tin oxide two-dimensional nanosheet on the micro hot plate electrode region and the area of ​​the micro hot plate electrode region, and the equivalent contact resistance can be the contact resistance exhibited after the Pt-modified tin oxide two-dimensional nanosheet and the micro hot plate electrode region form an electrical connection, which is used to characterize the adhesion and conduction state between the two-dimensional nanosheet and the micro hot plate electrode.

[0072] In one embodiment, the method for calculating the press-fit overlap ratio can be as follows: acquire a microscopic image of the gas sensing chip to be verified, identify the outline of the micro hot plate electrode region and the outline of the Pt-modified tin oxide two-dimensional nanosheet from the microscopic image; calculate the overlap area between the outline of the Pt-modified tin oxide two-dimensional nanosheet and the outline of the micro hot plate electrode region, and divide the overlap area by the area of ​​the micro hot plate electrode region to obtain the press-fit overlap ratio.

[0073] In one embodiment, the equivalent contact resistance can be measured by: contacting the test probes to the test ends of the micro hot plate electrode area, collecting the voltage value between the Pt-modified tin oxide two-dimensional nanosheet and the micro hot plate electrode area under a set test current; dividing the voltage value by the test current to obtain the equivalent contact resistance between the Pt-modified tin oxide two-dimensional nanosheet and the micro hot plate electrode area.

[0074] Through the above steps, the transfer quality of Pt-modified tin oxide two-dimensional nanosheets can be verified from two aspects: position coverage state and electrical connection state, providing a quantitative basis for subsequent judgment on whether the feature gas sensing chip to be verified meets the finished product requirements.

[0075] Optionally, calculating the overlap ratio of the gas sensing chip to be verified includes: Obtain a chip image of the gas sensing chip to be verified, and identify the nanosheet projection area of ​​the Pt-modified tin oxide two-dimensional nanosheet and the electrode projection area of ​​the micro hot plate electrode area from the chip image.

[0076] Among them, the chip image can be an image obtained by microscopic imaging of the gas sensing chip to be verified, the nanosheet projection area can be the coverage area of ​​the Pt-modified tin oxide two-dimensional nanosheet in the chip image, and the electrode projection area can be the location area of ​​the micro hot plate electrode area in the chip image.

[0077] In one embodiment, the method for identifying the nanosheet projection region can be as follows: acquiring a chip image of the gas sensing chip to be verified using a microscopic imaging device, performing grayscale conversion, filtering, and edge enhancement processing on the chip image, identifying the edge contour of the Pt-modified tin oxide two-dimensional nanosheet from the processed chip image, and determining the area enclosed by the edge contour as the nanosheet projection region.

[0078] In one embodiment, the electrode projection area can be identified by: identifying the metal boundary of the micro hotplate electrode from the chip image, and determining the area enclosed by the metal boundary as the electrode projection area.

[0079] Through the above steps, the location regions of the coverage area and the micro-hot plate electrode area of ​​the Pt-modified tin oxide two-dimensional nanosheet can be extracted from the chip image, providing an image region basis for subsequent calculation of the pressing overlap ratio.

[0080] Calculate the overlap area between the nanosheet projection region and the electrode projection region, as well as the electrode area of ​​the electrode projection region.

[0081] The overlapping area can be the area where the nanosheet projection area and the electrode projection area overlap in the chip image, and the electrode area can be the overall area of ​​the electrode projection area in the chip image.

[0082] In one embodiment, the method for calculating the overlapping area can be: mapping the nanosheet projection area and the electrode projection area to the same image coordinate system, extracting the overlapping pixels between the nanosheet projection area and the electrode projection area, and multiplying the number of overlapping pixels by the actual area corresponding to a single pixel to obtain the overlapping area.

[0083] In one embodiment, the electrode area can be calculated by counting the number of pixels in the electrode projection area, multiplying the number of pixels in the electrode projection area by the actual area corresponding to a single pixel, and obtaining the electrode area.

[0084] The above steps can quantify the actual coverage relationship between the Pt-modified tin oxide two-dimensional nanosheets and the micro-hot plate electrode area, providing area data for subsequent calculation of the press-fit overlap ratio based on the overlap area and electrode area.

[0085] The overlap ratio is obtained by dividing the overlap area by the electrode area.

[0086] The overlap ratio can be a proportional value used to characterize the extent to which Pt-modified tin oxide two-dimensional nanosheets cover the electrode area of ​​the micro-hot plate.

[0087] In one embodiment, the crimping overlap ratio can be calculated by reading the overlap area and the electrode area, using the overlap area as the numerator and the electrode area as the denominator, and calculating the ratio between the two to obtain the crimping overlap ratio.

[0088] Through the above steps, the coverage relationship between the Pt-modified tin oxide two-dimensional nanosheet and the micro-hot plate electrode area can be converted into a quantitative ratio, providing a basis for judging whether the transfer position of the gas sensing chip to be verified is qualified.

[0089] Optionally, measuring the equivalent contact resistance between the Pt-modified tin oxide two-dimensional nanosheet and the micro-hot plate electrode region includes: A detection voltage is applied to the detection electrode in the hot plate electrode region of the gas sensing chip to be verified.

[0090] The detection electrode can be an electrode in the hot plate electrode region used to detect the electrical connection state of the Pt-modified tin oxide two-dimensional nanosheets, and the detection voltage can be a test voltage applied to the detection electrode to form a detection current between the Pt-modified tin oxide two-dimensional nanosheets and the hot plate electrode region.

[0091] In one embodiment, the detection voltage can be applied by: contacting the test probe with the detection electrode of the gas sensing chip to be verified, activating the electrical testing equipment, and applying a preset detection voltage to the detection electrode, so that the detection electrode, the Pt-modified tin oxide two-dimensional nanosheet, and the micro-hot plate electrode area form a test circuit.

[0092] Through the above steps, stable electrical test conditions can be established on the detection electrode of the gas sensing chip to be verified, providing a basis for subsequent measurement of the equivalent contact resistance between the Pt-modified tin oxide two-dimensional nanosheet and the micro-hot plate electrode area.

[0093] The detection current corresponding to the detection electrode is collected.

[0094] The detection current can be the current value flowing through the test circuit formed by the detection electrode, the Pt-modified tin oxide two-dimensional nanosheet, and the micro-hotplate electrode region after a detection voltage is applied to the detection electrode. The detection current can be used to characterize the conduction state between the Pt-modified tin oxide two-dimensional nanosheet and the micro-hotplate electrode region.

[0095] In one embodiment, the method for acquiring the detection current may be: after applying a detection voltage to the detection electrode, reading the current response value in the test circuit through an electrical testing device, and determining the read current response value as the detection current.

[0096] The above steps enable the acquisition of the current response corresponding to the detection electrode, providing current data for subsequent calculation of the equivalent contact resistance between the Pt-modified tin oxide two-dimensional nanosheet and the micro-hot plate electrode region in conjunction with the detection voltage.

[0097] Dividing the detection voltage by the detection current yields the equivalent contact resistance between the Pt-modified tin oxide two-dimensional nanosheet and the micro-hot plate electrode region.

[0098] The equivalent contact resistance can be a resistance value used to characterize the electrical connection state between the Pt-modified tin oxide two-dimensional nanosheet and the electrode region of the micro-hot plate.

[0099] In one embodiment, the equivalent contact resistance can be calculated by reading the detection voltage and the detection current, using the detection voltage as the numerator and the detection current as the denominator, and calculating the ratio between the two to obtain the equivalent contact resistance between the Pt-modified tin oxide two-dimensional nanosheet and the micro-hot plate electrode region.

[0100] Through the above steps, the detection voltage and detection current collected during the electrical detection process can be converted into equivalent contact resistance, providing a quantitative basis for subsequent determination of whether a stable electrical connection is formed between the Pt-modified tin oxide two-dimensional nanosheet and the micro hot plate electrode region.

[0101] S15033, when the overlap ratio of the crimping is greater than 90% and the equivalent contact resistance is less than the set preset resistance threshold, the transfer of the gas sensing chip to be verified is deemed qualified, and the litchi quality characteristic gas sensing chip is obtained.

[0102] The preset resistance threshold can be the maximum allowable resistance value used to determine whether the transfer contact is qualified. The preset resistance threshold can be set to 100kΩ.

[0103] In one embodiment, the method for determining whether the transfer is qualified can be: if the overlap ratio of the press is greater than 90% and the equivalent contact resistance is less than a preset resistance threshold, it is determined that the Pt modified tin oxide two-dimensional nanosheet has fully covered the micro hot plate electrode area and formed a stable electrical connection with the micro hot plate electrode area, and the transfer is deemed qualified.

[0104] Through the above steps, the transfer quality of Pt-modified tin oxide two-dimensional nanosheets can be verified from both the transfer coverage area and the electrical contact state. This avoids situations where the coverage is in place but the electrical connection is unstable, or where the electrical connection exists but the coverage area is insufficient, thus obtaining a litchi quality characteristic gas sensing chip with qualified transfer.

[0105] Based on the above embodiments, Figure 6This is a schematic diagram of the structure of the litchi quality characteristic gas sensing chip fabrication apparatus provided in this application embodiment, used to implement the litchi quality characteristic gas sensing chip fabrication method of this application embodiment. (Reference) Figure 6 The litchi quality characteristic gas sensing chip preparation device provided in this embodiment specifically includes: oxidation module 11, deposition module 12, stripping module 13, etching module 14, and transfer module 15.

[0106] The system comprises the following modules: an oxidation module 11, configured to oxidize a tin substrate under set oxidation conditions to form a thin tin oxide layer on the surface of the tin substrate, resulting in a tin oxide composite substrate; a deposition module 12, configured to perform Pt atomic deposition on the tin oxide composite substrate to form atomically dispersed Pt catalytic sites on the surface of the tin oxide thin layer, resulting in a Pt-modified composite substrate; a stripping module 13, configured to strip the Pt-modified composite substrate to obtain Pt-modified tin oxide two-dimensional nanosheets; an etching module 14, configured to etch the chip substrate using deep reactive ion etching (DRIE) to obtain a micro-hotplate structure; and a transfer module 15, configured to transfer the Pt-modified tin oxide two-dimensional nanosheets to the micro-hotplate electrode area of ​​the micro-hotplate structure, resulting in a litchi quality characteristic gas sensing chip.

[0107] Based on the above embodiments, the oxidation module 11 includes: an atmosphere control unit configured to place the tin substrate in an atmosphere furnace and introduce a mixture of oxygen and argon into the atmosphere furnace, wherein the volume fraction of oxygen in the mixture is 20% to 30%; a temperature control unit configured to control the oxidation temperature of the atmosphere furnace at 400°C to 500°C; and an oxidation control unit configured to control the oxidation time at 2 hours to 3 hours, so that a thin layer of tin oxide is formed on the surface of the tin substrate, thereby obtaining a tin oxide composite substrate.

[0108] Based on the above embodiments, the etching module 14 includes: a cantilever beam etching unit configured to perform deep reactive ion etching on a first surface of the chip substrate to form a cantilever beam micro-hotplate structure on the first surface; and a cup-shaped etching unit configured to perform deep reactive ion etching on a second surface of the chip substrate to form a cup-shaped heat-insulating cavity corresponding to the cantilever beam micro-hotplate structure on the second surface, thereby obtaining a micro-hotplate structure. The first surface and the second surface are arranged opposite to each other. The length of the cantilever beam micro-hotplate structure is 500 μm, the width is 100 μm, and the thickness is 10 μm. The depth of the cup-shaped heat-insulating cavity is 200 μm.

[0109] Based on the above embodiments, the transfer module 15 includes: a transfer parameter unit configured to attach the Pt-modified tin oxide two-dimensional nanosheets to the transfer end of the transfer device, setting the transfer temperature of the transfer device to 80°C and the transfer pressure of the transfer device to 0.1 MPa; a positioning electric field unit configured to apply a 5V voltage to the positioning electrode of the micro-hot plate structure, so that a positioning electric field is formed between the Pt-modified tin oxide two-dimensional nanosheets and the micro-hot plate electrode of the micro-hot plate structure; and a chip pressing unit configured to press the Pt-modified tin oxide two-dimensional nanosheets to the micro-hot plate electrode area of ​​the micro-hot plate structure, so that the Pt-modified tin oxide two-dimensional nanosheets are positioned and attached to the micro-hot plate electrode area under the action of the positioning electric field, thereby obtaining a litchi quality characteristic gas sensing chip.

[0110] Based on the above embodiments, the chip pressing unit includes: an initial chip subunit, configured to press the Pt-modified tin oxide two-dimensional nanosheet to the micro-hot plate electrode region of the micro-hot plate structure, so that the Pt-modified tin oxide two-dimensional nanosheet is positioned and attached to the micro-hot plate electrode region under the action of the positioning electric field, to obtain a gas sensing chip to be verified; an overlap ratio subunit, configured to calculate the pressing overlap ratio of the gas sensing chip to be verified; an equivalent resistance subunit, configured to measure the equivalent contact resistance between the Pt-modified tin oxide two-dimensional nanosheet and the micro-hot plate electrode region; and a transfer verification subunit, configured to determine that the transfer of the gas sensing chip to be verified is qualified when the pressing overlap ratio is greater than 90% and the equivalent contact resistance is less than a preset resistance threshold, to obtain a litchi quality characteristic gas sensing chip.

[0111] Based on the above embodiments, the overlap ratio subunit includes: a region identification component configured to acquire a chip image of the gas sensing chip to be verified, and identify the nanosheet projection area of ​​the Pt-modified tin oxide two-dimensional nanosheet and the electrode projection area of ​​the micro hot plate electrode area from the chip image; an area calculation component configured to calculate the overlap area of ​​the nanosheet projection area and the electrode projection area and the electrode area of ​​the electrode projection area; and an overlap calculation component configured to divide the overlap area by the electrode area to obtain the pressing overlap ratio.

[0112] Based on the above embodiments, the equivalent resistance subunit includes: a detection voltage component configured to apply a detection voltage to a detection electrode in the micro-hot plate electrode region of the gas sensing chip to be verified; a detection current component configured to acquire the detection current corresponding to the detection electrode; and an equivalent resistance component configured to divide the detection voltage by the detection current to obtain the equivalent contact resistance between the Pt-modified tin oxide two-dimensional nanosheet and the micro-hot plate electrode region.

[0113] The litchi quality characteristic gas sensing chip fabrication apparatus provided in this application embodiment, through the coordinated operation of oxidation module 11, deposition module 12, stripping module 13, etching module 14, and transfer module 15, achieves a complete process from oxidation of the tin substrate, preparation of Pt-modified tin oxide two-dimensional nanosheets, to integration of the micro-hotplate structure. Oxidation module 11 is used to oxidize the tin substrate to obtain a tin oxide composite substrate; deposition module 12 is used to form atomically dispersed Pt catalytic sites on the surface of the tin oxide thin layer to obtain a Pt-modified composite substrate; stripping module 13 is used to strip Pt-modified tin oxide two-dimensional nanosheets; etching module 14 is used to perform deep reactive ion etching on the chip substrate to obtain the micro-hotplate structure; transfer module 15 is used to transfer the Pt-modified tin oxide two-dimensional nanosheets to the micro-hotplate electrode area to obtain the litchi quality characteristic gas sensing chip. This embodiment can improve the controllability of sensitive material preparation and chip integration, and enhance the consistency of chip fabrication.

[0114] The litchi quality characteristic gas sensing chip preparation device provided in this application embodiment can be used to execute the litchi quality characteristic gas sensing chip preparation method provided in the above embodiment, and has corresponding functions and beneficial effects.

[0115] Figure 7 This is a schematic diagram of a gas sensing chip fabrication system for lychee quality characteristics provided in an embodiment of this application. (Refer to...) Figure 7 The litchi quality characteristic gas sensing chip fabrication system includes: a processor 21, a memory 22, a communication device 23, an input device 24, and an output device 25. The litchi quality characteristic gas sensing chip fabrication system can have one or more processors 21, and the litchi quality characteristic gas sensing chip fabrication system can have one or more memories. The processor 21, memory 22, communication device 23, input device 24, and output device 25 of the litchi quality characteristic gas sensing chip fabrication system can be connected via a bus or other means.

[0116] The memory 22, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the litchi quality characteristic gas sensing chip fabrication apparatus in any embodiment of this application (e.g., the oxidation module 11, deposition module 12, stripping module 13, etching module 14, and transfer module 15 in the litchi quality characteristic gas sensing chip fabrication apparatus). The memory 22 may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a function; the data storage area may store data created based on the use of the device, etc. Furthermore, the memory 22 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some instances, the memory may further include memory remotely located relative to the processor, and these remote memories can be connected to the device via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0117] The communication device 23 is used for data transmission.

[0118] The processor 21 executes various functional applications and data processing of the device by running software programs, instructions and modules stored in the memory 22, thereby realizing the above-mentioned method for preparing a gas sensing chip for lychee quality characteristics.

[0119] Input device 24 can be used to receive input digital or character information, and to generate key signal inputs related to user settings and function control of the device. Output device 25 may include display devices such as a display screen.

[0120] The litchi quality characteristic gas sensing chip preparation system provided above can be used to drive the litchi quality characteristic gas sensing chip preparation device provided in the above embodiments, and has corresponding functions and beneficial effects.

[0121] This application also provides a storage medium containing computer-executable instructions. When executed by a computer processor, these instructions drive the fabrication of a litchi quality characteristic gas sensing chip. The fabrication of the litchi quality characteristic gas sensing chip, when operated, enables a method for fabricating the litchi quality characteristic gas sensing chip. The method includes, but is not limited to: oxidizing a tin substrate under set oxidation conditions to form a thin tin oxide layer on the surface of the tin substrate, obtaining a tin oxide composite substrate; performing Pt atomic deposition on the tin oxide composite substrate to form atomically dispersed Pt catalytic sites on the surface of the tin oxide thin layer, obtaining a Pt-modified composite substrate; performing a peeling process on the Pt-modified composite substrate to obtain Pt-modified tin oxide two-dimensional nanosheets; etching the chip substrate using a deep reactive ion etching process to obtain a micro-hotplate structure; and transferring the Pt-modified tin oxide two-dimensional nanosheets to the micro-hotplate electrode region of the micro-hotplate structure to obtain the litchi quality characteristic gas sensing chip.

[0122] Storage medium—any type of memory device or storage device. The term "storage medium" is intended to include: mounting media, such as CD-ROM, floppy disk, or magnetic tape devices; computer system memory or random access memory, such as DRAM, DDR RAM, SRAM, EDO RAM, etc.; non-volatile memory, such as flash memory, magnetic media (e.g., hard disk or optical storage); registers or other similar types of memory elements, etc. Storage medium may also include other types of memory or combinations thereof. Furthermore, storage medium may reside in a first computer system in which a program is executed, or it may reside in a different second computer system connected to the first computer system via a network (such as the Internet). The second computer system can provide program instructions to the first computer for execution. The term "storage medium" may include two or more storage media residing in different locations (e.g., in different computer systems connected via a network). Storage medium may store program instructions (e.g., specifically implemented as a computer program) executable by one or more processors.

[0123] Of course, the storage medium containing computer-executable instructions provided in the embodiments of this application, which drives the above-mentioned litchi quality characteristic gas sensing chip preparation device to run, is not limited to implementing the related operations of the above-mentioned litchi quality characteristic gas sensing chip preparation method, but can also implement the related operations in the litchi quality characteristic gas sensing chip preparation method provided in any embodiment of this application.

[0124] The storage medium and litchi quality characteristic gas sensing chip preparation system provided in the above embodiments can drive the litchi quality characteristic gas sensing chip preparation device provided in any embodiment of this application. For technical details not described in detail in the above embodiments, please refer to the litchi quality characteristic gas sensing chip preparation device provided in any embodiment of this application.

[0125] The above description is merely a preferred embodiment and the technical principles employed in this application. This application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions that can be made by those skilled in the art will not depart from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application. The scope of this application is determined by the scope of the claims.

Claims

1. A method for fabricating a gas sensing chip for litchi quality characteristics, characterized in that, include: Under set oxidation conditions, a tin substrate is oxidized to form a thin layer of tin oxide on the surface of the tin substrate, resulting in a tin oxide composite substrate. The tin oxide composite substrate is subjected to Pt atomic deposition treatment to form atomically dispersed Pt catalytic sites on the surface of the tin oxide thin layer, thereby obtaining a Pt modified composite substrate; The Pt-modified composite substrate was subjected to a peeling process to obtain Pt-modified tin oxide two-dimensional nanosheets; The chip substrate was etched using deep reactive ion etching (DRIE) to obtain the micro hot plate structure. The Pt-modified tin oxide two-dimensional nanosheets were transferred to the micro-hot plate electrode area of ​​the micro-hot plate structure to obtain a litchi quality characteristic gas sensing chip.

2. The method for preparing a litchi quality characteristic gas sensing chip according to claim 1, characterized in that, The step of oxidizing a tin substrate under set oxidation conditions to form a thin layer of tin oxide on the surface of the tin substrate, thereby obtaining a tin oxide composite substrate, includes: A tin substrate is placed in an atmosphere furnace, and a mixture of oxygen and argon is introduced into the atmosphere furnace, wherein the volume fraction of oxygen in the mixture is 20% to 30%. The oxidation temperature of the atmosphere furnace is controlled at 400°C to 500°C; The oxidation time is controlled to be 2 to 3 hours, so that a thin layer of tin oxide is formed on the surface of the tin substrate, thus obtaining a tin oxide composite substrate.

3. The method for preparing a litchi quality characteristic gas sensing chip according to claim 1, characterized in that, The process employs deep reactive ion etching to etch the chip substrate, resulting in a micro hotspot structure, including: Deep reactive ion etching is performed on the first surface of the chip substrate to form a cantilever beam micro-hot plate structure on the first surface; Deep reactive ion etching is performed on the second surface of the chip substrate to form a cup-shaped heat-insulating cavity corresponding to the cantilever beam micro-hot plate structure, thus obtaining the micro-hot plate structure. The first surface and the second surface are arranged opposite to each other. The cantilever beam micro-heat plate structure has a length of 500μm, a width of 100μm, and a thickness of 10μm. The cup-shaped heat insulation cavity has a depth of 200μm.

4. The method for preparing a litchi quality characteristic gas sensing chip according to claim 1, characterized in that, The process of transferring the Pt-modified tin oxide two-dimensional nanosheets onto the micro-hot plate electrode region of the micro-hot plate structure to obtain a litchi quality characteristic gas sensing chip includes: The Pt-modified tin oxide two-dimensional nanosheets were attached to the transfer end of a transfer device, and the transfer temperature of the transfer device was set to 80°C and the transfer pressure of the transfer device was set to 0.1 MPa. A 5V voltage is applied to the positioning electrode of the micro-hot plate structure to form a positioning electric field between the Pt-modified tin oxide two-dimensional nanosheet and the micro-hot plate electrode of the micro-hot plate structure. The Pt-modified tin oxide two-dimensional nanosheets are pressed onto the micro-hot plate electrode region of the micro-hot plate structure, so that the Pt-modified tin oxide two-dimensional nanosheets are positioned and attached to the micro-hot plate electrode region under the action of the positioning electric field, thus obtaining a litchi quality characteristic gas sensing chip.

5. The method for preparing a litchi quality characteristic gas sensing chip according to claim 4, characterized in that, The process of pressing the Pt-modified tin oxide two-dimensional nanosheets onto the micro-hot plate electrode region of the micro-hot plate structure, thereby positioning and attaching the Pt-modified tin oxide two-dimensional nanosheets to the micro-hot plate electrode region under the action of the positioning electric field, yields a litchi quality characteristic gas sensing chip, comprising: The Pt-modified tin oxide two-dimensional nanosheets are pressed onto the micro-hot plate electrode area of ​​the micro-hot plate structure, so that the Pt-modified tin oxide two-dimensional nanosheets are positioned and attached to the micro-hot plate electrode area under the action of the positioning electric field, thus obtaining the feature gas sensing chip to be verified. Calculate the overlap ratio of the gas sensing chip to be verified, and measure the equivalent contact resistance between the Pt-modified tin oxide two-dimensional nanosheet and the electrode area of ​​the micro-hot plate. If the overlap ratio of the crimping is greater than 90% and the equivalent contact resistance is less than the preset resistance threshold, the transfer of the gas sensing chip to be verified is deemed qualified, and the litchi quality characteristic gas sensing chip is obtained.

6. The method for preparing a litchi quality characteristic gas sensing chip according to claim 5, characterized in that, The calculation of the overlay ratio of the gas sensing chip to be verified includes: Obtain a chip image of the gas sensing chip to be verified, and identify the nanosheet projection area of ​​the Pt-modified tin oxide two-dimensional nanosheet and the electrode projection area of ​​the micro hot plate electrode area from the chip image. Calculate the overlap area between the nanosheet projection region and the electrode projection region, as well as the electrode area of ​​the electrode projection region; The overlap ratio is obtained by dividing the overlap area by the electrode area.

7. The method for preparing a litchi quality characteristic gas sensing chip according to claim 5, characterized in that, The measurement of the equivalent contact resistance between the Pt-modified tin oxide two-dimensional nanosheet and the micro-hot plate electrode region includes: A detection voltage is applied to the detection electrode in the hot plate electrode region of the gas sensing chip to be verified; Collect the detection current corresponding to the detection electrode; Dividing the detection voltage by the detection current yields the equivalent contact resistance between the Pt-modified tin oxide two-dimensional nanosheet and the micro-hot plate electrode region.

8. A device for preparing a gas sensing chip for lychee quality characteristics, characterized in that, include: An oxidation module is configured to oxidize a tin substrate under set oxidation conditions, thereby forming a thin layer of tin oxide on the surface of the tin substrate to obtain a tin oxide composite substrate. A deposition module is configured to perform Pt atomic deposition on the tin oxide composite substrate to form atomically dispersed Pt catalytic sites on the surface of the tin oxide thin layer, thereby obtaining a Pt-modified composite substrate. The stripping module is configured to strip the Pt-modified composite substrate to obtain Pt-modified tin oxide two-dimensional nanosheets. The etching module is configured to use deep reactive ion etching (DRIE) to etch the chip substrate to obtain a micro hot plate structure. The transfer module is configured to transfer the Pt-modified tin oxide two-dimensional nanosheets to the micro-hot plate electrode area of ​​the micro-hot plate structure to obtain a litchi quality characteristic gas sensing chip.

9. A system for fabricating a gas sensing chip for lychee quality characteristics, characterized in that, include: One or more processors; The memory stores one or more programs that, when executed by the one or more processors, cause the one or more processors to drive the litchi quality characteristic gas sensing chip preparation apparatus as described in claim 8.

10. A storage medium containing computer-executable instructions, characterized in that, The computer-executable instructions, when executed by a computer processor, are used to drive the litchi quality characteristic gas sensing chip preparation apparatus as described in claim 8.

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