Imaging system for studying improvement of sensitivity essence of gas sensor by sound tweezers

Abstract

The invention discloses an imaging system for studying improvement of sensitivity essence of a gas sensor by acoustic tweezers, which is provided with a sound source module and an optical imaging module, the gas sensor is placed at an antinode position of a sound field generated by the acoustic tweezers, the sensor is irradiated by a sheet-shaped light source, and the sheet-shaped light is scattered by gas, so that the sensitivity essence of the gas sensor is improved. Scattered light is shot and collected by a camera through gas on the gas sensor and a lens assembly and then processed through a data processing module, the gas concentration gradient on the gas sensor is obtained by moving the position of the sheet-shaped light source, analysis is conducted in combination with relevant parameters of the sound tweezers, and the research on the effect of the sound tweezers on improving the sensitivity of the gas sensor is facilitated. The problem that no related analysis system exists in the prior art is solved. Furthermore, a first convex lens and a second convex lens are adopted in the lens assembly, a double-telecentric light path is formed, the double-telecentric light path can receive parallel light more easily, and due to the characteristic, the contrast ratio of images shot by the camera is obvious, and recognition and detection of a follow-up algorithm are facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of gas sensing analysis, and in particular to an imaging system for studying the essence of acoustic tweezers in improving the sensitivity of a gas sensor. Background Art

[0002] Trace gas detection is closely related to human health, environmental protection, industrial production, etc. High-sensitivity trace gas sensing can timely and accurately monitor and control trace gas components, reduce accident risks, improve safety production coefficients, and achieve high-precision monitoring of human exhaled breath, and achieve early detection and early diagnosis of diseases such as lung cancer and asthma. In high-sensitivity gas sensing, some patents reconstruct the micro-nano surface interface materials of gas sensors to improve sensing sensitivity, and the article "Physical principle of enhancing the sensitivity of a metal oxide gas sensor using bulk acoustic waves" proposes the use of acoustic tweezers to increase the sensing baseline and improve the sensing sensitivity of gas.

[0003] In the above-mentioned technical means, the change of gas concentration on the surface of the material under the condition of acoustic tweezers is not explored to characterize the essential reason for the improvement of gas sensing sensitivity. Therefore, it is necessary to provide an imaging system for studying the essence of acoustic tweezers to improve the sensitivity of gas sensors. Summary of the invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide an imaging system for studying the nature of acoustic tweezers in improving the sensitivity of gas sensors.

[0005] The present invention provides an imaging system for studying the nature of acoustic tweezers improving the sensitivity of gas sensors, comprising:

[0006] A sound source module, comprising two acoustic tweezers symmetrically arranged on both sides of the gas sensor along a first direction, and the openings of the two acoustic tweezers face the gas sensor;

[0007] An optical imaging module, comprising a sheet-shaped light source disposed on one side of the gas sensor along a second direction, a camera disposed on a side of the gas sensor away from the sheet-shaped light source, and a lens assembly disposed between the camera and the gas sensor, wherein a central line connecting the centers of the sheet-shaped light source, the gas sensor, the lens assembly, and the camera forms a central axis, an extension direction of the central axis is the second direction, and the second direction is perpendicular to the first direction;

[0008] The lens assembly includes an objective lens, a first convex lens, a second convex lens, and a focusing lens arranged in sequence along a second direction from the gas sensor toward the camera, and the focal points of the first convex lens and the second convex lens on the sides close to each other overlap;

[0009] The data processing module is used to process the image information collected by the camera.

[0010] According to the technical solution provided in the embodiment of the present application, a liquid lens is further provided between the second convex lens and the focusing lens.

[0011] According to the technical solution provided in the embodiment of the present application, the sound source module further includes an adjustment component, which is used to simultaneously adjust the distance between the two acoustic tweezers and the gas sensor along the first direction.

[0012] According to the technical solution provided in the embodiment of the present application, the adjustment assembly includes two synchronously rotating screws, the threads of the two screws have opposite rotation directions, and the axis extension directions are both in the first direction, the two screws are threadedly connected with nuts, and the outer sides of the two nuts are provided with adjustment rods, the two adjustment rods are respectively connected to the two side surfaces of the acoustic tweezers, and the adjustment assembly also includes a limiter, which is used to limit the rotation of the adjustment rod around the screw.

[0013] According to the technical solution provided in the embodiment of the present application, the limiting member includes a limiting plate, a limiting groove for the adjustment rod to pass through is provided in the middle of the limiting plate, and the extension directions of the limiting plate and the limiting groove are both the first direction.

[0014] According to the technical solution provided in the embodiment of the present application, the lens assembly further includes a housing, the two screws are rotatably connected to the housing, and the limiting plate is connected to the outer surface of the housing.

[0015] According to the technical solution provided in the embodiment of the present application, the two screw rods are detachably connected between their close ends via a coupling, a bearing is mounted outside the coupling, a first connecting rod connected to the outer shell is provided on the outer wall of the bearing, and a second connecting rod connected to the outer shell is provided on one side surface of the middle part of the limit plate.

[0016] According to the technical solution provided in the embodiment of the present application, the data processing module includes an image preprocessing submodule, an interference fringe extraction submodule, a fringe frequency calculation submodule, a gas concentration calculation submodule, a three-dimensional information generation submodule and a gas concentration gradient submodule;

[0017] The image preprocessing submodule is used to process the image taken by the camera, perform noise reduction and grayscale processing on the image, and obtain a grayscale image;

[0018] The interference fringe extraction submodule is used to identify and process the interference fringes in the grayscale image to obtain a fringe image containing fringes with a single pixel width;

[0019] The fringe frequency calculation submodule is used to process the fringe image to obtain the fringe frequency of the interference fringe;

[0020] The gas concentration calculation submodule calculates the gas concentration value at the corresponding position based on the gas concentration and fringe frequency relationship model and the fringe frequency of the interference fringe;

[0021] The three-dimensional information generation submodule is to form three-dimensional information of the surface interface of the gas sensor micro-nano structure by combining the gas concentration value data of multiple positions;

[0022] The gas concentration gradient submodule calculates the difference in gas concentration between adjacent positions in the three-dimensional information to obtain the gas concentration gradient distribution on the surface of the gas sensor micro-nano structure.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] A sound source module and an optical imaging module are set up, and a gas sensor is placed at the antinode position of the sound field generated by the acoustic tweezers. The sensor is irradiated with a sheet light source, and the sheet light is scattered by the gas. The scattered light passes through the gas and the lens assembly on the gas sensor and is photographed and collected by a camera. After being processed by the data processing module, the gas concentration gradient on the gas sensor is obtained by moving the position of the sheet light source, and is analyzed in combination with the relevant parameters of the acoustic tweezers, so as to explore the role of the acoustic tweezers in improving the sensitivity of the gas sensor and solve the problem that there is no relevant analysis system in the prior art.

[0025] Furthermore, the lens assembly uses a first convex lens and a second convex lens to form a double telecentric optical path, which is more likely to receive parallel light. This feature makes the image captured by the camera have a clear contrast, which is convenient for subsequent algorithm recognition and detection. In addition, a liquid lens is also provided. By adjusting the focal length of the liquid lens, the gas concentration in different areas can be detected, thereby improving the comprehensiveness of data acquisition.

[0026] Furthermore, an adjustment component is provided to adjust the position between the two acoustic tweezers to achieve the purpose of variable test, so as to obtain more acoustic tweezers-related data for analysis. Furthermore, the two screws are rotated synchronously to drive the acoustic tweezers to move synchronously, so as to ensure that the gas sensor is always located between the two acoustic tweezers, thereby avoiding the situation where the distance deviation causes errors in subsequent analysis results.

[0027] Furthermore, a data processing module is finally set up to process the images taken by the camera through the image preprocessing submodule, interference fringe extraction submodule, fringe frequency calculation submodule, gas concentration calculation submodule, three-dimensional information generation submodule and gas concentration gradient submodule, and finally the gas concentration gradient distribution on the surface interface of the gas sensor micro-nano structure is obtained, which is convenient for subsequent analysis in combination with the relevant parameters of the acoustic tweezers.

[0028] It should be understood that the contents described in the summary of the invention are not intended to limit the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0030] Figure 1 A structural block diagram of an imaging system for studying the nature of acoustic tweezers to improve the sensitivity of gas sensors provided in an embodiment of the present application;

[0031] Figure 2 A schematic diagram of the optical path of a lens assembly in an imaging system for studying the nature of acoustic tweezers to improve the sensitivity of a gas sensor provided in an embodiment of the present application;

[0032] Figure 3 A schematic diagram of the structure of an adjustment component in an imaging system for studying the nature of acoustic tweezers to improve the sensitivity of a gas sensor provided in an embodiment of the present application;

[0033] Figure 4 A schematic diagram of the structure of a first connecting rod and a second connecting rod in an imaging system for studying the nature of acoustic tweezers to improve the sensitivity of a gas sensor provided in an embodiment of the present application.

[0034] Numbers in the figure: 1. sound source module; 11. acoustic tweezers; 12. adjustment component; 121. coupling; 122. screw; 123. nut; 124. adjustment rod; 125. limit plate; 126. limit groove; 127. bearing; 128. first connecting rod; 129. second connecting rod; 2. optical imaging module; 21. sheet light source; 22. lens assembly; 221. objective lens; 222. first convex lens; 223. second convex lens; 224. liquid lens; 225. focusing lens; 226. housing; 23. camera; 3. data processing module; 31. image preprocessing submodule; 32. interference fringe extraction submodule; 33. fringe frequency calculation submodule; 34. gas concentration calculation submodule; 35. three-dimensional information generation submodule; 36. gas concentration gradient submodule; 4. gas sensor. DETAILED DESCRIPTION

[0035] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It should also be noted that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0036] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0037] Please refer to Figure 1 to Figure 4 The embodiment of the present invention provides an imaging system for studying the nature of acoustic tweezers improving the sensitivity of gas sensors, comprising:

[0038] The sound source module 1 comprises two acoustic tweezers 11 symmetrically arranged on both sides of the gas sensor 4 along the first direction, and the openings of the two acoustic tweezers 11 face the gas sensor 4; wherein the center position of the two acoustic tweezers 11 is the antinode position, and the core advantage of placing the gas sensor 4 at the antinode of the ultrasonic standing wave is to utilize the maximum sound pressure amplitude and energy density at this position, and significantly improve the detection sensitivity by enhancing the gas-sensor interaction, the local enrichment effect and the amplified mechanical response;

[0039] The optical imaging module 2 includes a sheet light source 21 disposed on one side of the gas sensor 4 along the second direction, a camera 23 disposed on the side of the gas sensor 4 away from the sheet light source 21, and a lens assembly 22 disposed between the camera 23 and the gas sensor 4. The center line of the sheet light source 21, the gas sensor 4, the lens assembly 22 and the camera 23 forms a central axis, and the extension direction of the central axis is the second direction, and the second direction is perpendicular to the first direction; wherein the first direction is Figure 2 The up and down directions in the second direction are Figure 2 The sheet characteristics of the sheet light source 21 in the vertical direction help to improve the spatial resolution, so as to more accurately locate the gas concentration gradient, and the sheet light source 21 only illuminates a specific area, reducing background light interference, improving image contrast, and evenly illuminating the surface of the gas sensor 4, avoiding light intensity non-uniformity, and improving measurement accuracy. The clear structured light helps subsequent image processing and facilitates the detection of concentration gradient changes.

[0040] The lens assembly 22 includes an objective lens 221, a first convex lens 222, a second convex lens 223, and a focusing lens 225, which are sequentially arranged along the second direction from the gas sensor 4 toward the camera 23, and the focal points of the first convex lens 222 and the second convex lens 223 on the sides close to each other overlap;

[0041] A data processing module 3, used for processing image information collected by the camera 23;

[0042] like Figure 1 and Figure 2As shown, a sound source module 1 and an optical imaging module 2 are provided, and acoustic tweezers 11 are placed above and below the gas sensor 4. When the acoustic tweezers 11 are started, the sheet light source 21 emits light to form a light source, and the light passes through the gas and the lens assembly 22 on the gas sensor 4 and is photographed and collected by the camera 23. After being processed by the data processing module 3, the gas concentration gradient on the gas sensor 4 is obtained, and the relevant parameters of the acoustic tweezers 11 are combined for analysis, so as to explore the role of the acoustic tweezers 11 in improving the sensitivity of the gas sensor 4, and solve the problem that there is no relevant analysis system in the prior art.

[0043] Furthermore, the lens assembly 22 uses a first convex lens 222 and a second convex lens 223. Because the focal points of the two sides close to each other coincide, a double telecentric optical path is formed. The double telecentric optical path is more likely to receive parallel light. This feature makes the image captured by the camera 23 have obvious contrast, which is convenient for subsequent algorithm recognition and detection.

[0044] In some embodiments, a liquid lens 224 is further disposed between the second convex lens 223 and the focusing lens 225; Figure 2 and Figure 3 As shown, the liquid lens 224 is a lens with adjustable focal length. By adjusting the focal length of the liquid lens 224, the gas concentration in different areas can be detected, thereby improving the comprehensiveness of data acquisition.

[0045] In some embodiments, the sound source module 1 further includes an adjustment component 12, and the adjustment component 12 is used to simultaneously adjust the distance between the two acoustic tweezers 11 and the gas sensor 4 along the first direction;

[0046] like Figure 2 and Figure 3 As shown, by adjusting the position between the two acoustic tweezers 11, the purpose of variable test is achieved, which makes it easier to obtain more acoustic tweezers 11 related data for analysis.

[0047] In some embodiments, the adjustment component 12 includes two synchronously rotating screw rods 122, the threads of the two screw rods 122 are opposite to each other, and the axis extension direction is the first direction, the two screw rods 122 are threadedly connected with nuts 123, and the outer sides of the two nuts 123 are provided with adjustment rods 124, and the two adjustment rods 124 are respectively connected to the side surfaces of the two acoustic tweezers 11, and the adjustment component 12 also includes a limiter, which is used to limit the adjustment rod 124 from rotating around the screw rod 122;

[0048] like Figure 2 and Figure 3 As shown, the synchronous rotation of the two screws 122 drives the acoustic tweezers 11 to move synchronously, ensuring that the gas sensor 4 is always located between the two acoustic tweezers 11, thereby avoiding the situation where the distance deviation causes errors in subsequent analysis results.

[0049] In some embodiments, the limiting member includes a limiting plate 125, a limiting groove 126 is provided in the middle of the limiting plate 125 for the adjusting rod 124 to pass through, and the extending directions of the limiting plate 125 and the limiting groove 126 are both the first direction;

[0050] like Figure 3 As shown, the structure of this type of limiter is simple and can ensure the stability of the adjustment rod 124. Furthermore, the limit plate 125 is provided with scale values ​​extending from the center to both sides, so as to more accurately obtain the position data of the acoustic tweezers 11.

[0051] In some embodiments, the lens assembly 22 further includes a housing 226, the two screws 122 are rotatably connected to the housing 226, and the limit plate 125 is connected to the outer surface of the housing 226;

[0052] like Figure 3 and Figure 4 As shown, the adjustment component 12 can move synchronously with the housing 226 of the lens component 22, thereby ensuring that the center positions of the two acoustic tweezers 11 coincide with the central axis, making it easier to use the adjustment component 12 and the lens component 22.

[0053] In some embodiments, the two screw rods 122 are detachably connected to each other through a coupling 121, a bearing 127 is sleeved on the outer surface of the coupling 121, a first connecting rod 128 connected to the outer shell 226 is provided on the outer wall of the bearing 127, and a second connecting rod 129 connected to the outer shell 226 is provided on one side surface of the middle part of the limiting plate 125; Figure 4 As shown, holding or fixing the housing 226 can fix the screw rod 122. The two screw rods 122 cooperate with each other through the coupling 121 and the bearing 127 to achieve stable synchronous rotation and ensure the stability of the adjustment.

[0054] In some embodiments, the data processing module 3 includes an image preprocessing submodule 31, an interference fringe extraction submodule 32, a fringe frequency calculation submodule 33, a gas concentration calculation submodule 34, a three-dimensional information generation submodule 35 and a gas concentration gradient submodule 36;

[0055] The image preprocessing submodule 31 is used to process the image captured by the camera 23, perform noise reduction and grayscale processing on the image, and obtain a grayscale image;

[0056] The interference fringe extraction submodule 32 is used to identify and process the interference fringes in the grayscale image to obtain a fringe image containing fringes with a single pixel width;

[0057] The fringe frequency calculation submodule 33 is used to process the fringe image and obtain the fringe frequency of the interference fringe;

[0058] The gas concentration calculation submodule 34 calculates the gas concentration value at the corresponding position based on the gas concentration and fringe frequency relationship model and the fringe frequency of the interference fringe;

[0059] The three-dimensional information generation submodule 35 combines the gas concentration value data at multiple positions to form three-dimensional information of the micro-nano structure surface interface of the gas sensor 4;

[0060] The gas concentration gradient submodule 36 calculates the difference in gas concentration between adjacent positions in the three-dimensional information to obtain the gas concentration gradient distribution on the surface of the micro-nano structure of the gas sensor 4.

[0061] The method for using the optical analysis system specifically includes the following steps:

[0062] Step 1, rotating the screw 122, driving the nut 123 to move synchronously, driving the acoustic tweezers 11 to move synchronously through the nut 123 and the adjusting rod 124, after being fixed, starting the acoustic tweezers 11, and recording the relevant parameters of the acoustic tweezers 11, including the distance between the screw 122 and the gas sensor 4 and the sound frequency and sound decibel of the acoustic tweezers 11;

[0063] Step 2: Adjust the focal length of the liquid lens 224. After each adjustment, take photos with the camera 23 to obtain several sets of image information containing interference fringes. Each set of image information corresponds to a depth level of the micro-nano structure surface of the gas sensor 4. All depth levels are combined to form the entire three-dimensional area of ​​the micro-nano structure surface of the gas sensor 4. In addition, each time the focal length of the liquid lens 224 is adjusted, the position of the sheet light source 21 needs to be moved horizontally to ensure that the light can be focused by the focusing lens 223 and incident on the camera 23.

[0064] Step 3: Process each image information through the image preprocessing submodule 31;

[0065] Firstly, the median filter algorithm is used to process the interference image to remove isolated noise points such as salt and pepper noise in the image, while better retaining the image edge details;

[0066] Then grayscale processing is performed to convert the color image into a grayscale image;

[0067] Step 4: the interference fringe extraction submodule 32 processes the grayscale image;

[0068] First, the Sobel operator is used to detect the edge of the preprocessed image. The Sobel operator detects the edge by calculating the grayscale change gradient of the image in the horizontal and vertical directions. For each pixel in the image, its gradient value in the horizontal and vertical directions is calculated respectively, and then the pixel is judged whether it is an edge point according to the set threshold, and finally the interference fringe edge that can clearly identify the surface is selected;

[0069] Then, the image is processed by a morphological thinning algorithm, such as a thinning algorithm based on a structural element, by continuously eroding edge pixels until the thinning condition is met, that is, when there is only one connected component in the neighborhood of a pixel point and the pixel point is an edge point, the pixel point is retained, otherwise it is deleted, and this process is repeated until the stripe reaches a single-pixel width, thereby obtaining a stripe image containing stripes with a single-pixel width.

[0070] Step 5, the fringe frequency calculation submodule 33 processes the fringe image containing single-pixel width fringe;

[0071] First, perform a two-dimensional Fourier transform on the fringe image. The Fourier transform converts the image from the spatial domain to the frequency domain, so that the frequency information of the interference fringes can be obtained and presented as a spectrum diagram;

[0072] Then, through the peak detection algorithm, the pixel points in the spectrum are traversed to find the local maximum point with an amplitude greater than the set threshold as the peak point, and its corresponding frequency is the fringe frequency of the interference fringe;

[0073] Step 6: The gas concentration calculation submodule 34 calculates the gas concentration value at each depth level;

[0074] Among them, the relationship model between gas concentration and fringe frequency can adopt a linear model.

[0075] C=aF+b

[0076] Wherein, C is the gas concentration, F is the fringe frequency, a and b are fitting coefficients, which are obtained by simulation through pre-experimental establishment, and then the fringe frequency corresponding to each image information can be calculated to obtain the corresponding gas concentration value, and the gas concentration value corresponds to a depth level of the surface interface of the micro-nano structure of the gas sensor 4;

[0077] Step 7, the three-dimensional information generation submodule 35 processes the gas concentration value data at each depth level;

[0078] First, a registration method based on feature points is used, such as the SIFT (Scale Invariant Feature Transform) algorithm. First, an image information is used as the initial image, feature points are extracted from the initial image, and then matching feature points are found in the remaining image information. By calculating the transformation matrix between the feature points, the remaining image information is transformed into the same coordinate system as the initial image.

[0079] Then, the image information is combined. Based on the volume rendering method, the registered images can be regarded as different slices in the three-dimensional volume data. According to the position of each pixel point in the three-dimensional space, it is mapped into the three-dimensional space through algorithms such as ray projection, and finally a three-dimensional image of the surface interface of the micro-nano structure of the gas sensor 4 is obtained as the three-dimensional information output of the surface interface of the micro-nano structure of the gas sensor 4;

[0080] Step 8, the gas concentration gradient submodule 36 calculates the difference in gas concentration between adjacent positions in the three-dimensional information;

[0081] Through the concentration difference formula:

[0082] G x (i,j)=C(i+1,j)-C(i,j)

[0083] G y (i,j)=C(i,j+1)-C(i,j)

[0084] Among them, G x is the gas concentration difference in the horizontal direction, G y is the gas concentration difference in the horizontal direction, (i, j is the pixel position, and finally the gas concentration gradient distribution on the surface of the micro-nano structure of the gas sensor 4 is obtained.

[0085] In the description of this specification, the terms "connection", "installation", "fixation" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0086] In the description of this specification, the description of the terms "one embodiment", "some embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0087] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An imaging system for studying the nature of acoustic tweezers to improve the sensitivity of gas sensors, characterized in that: include: A sound source module (1) comprising two acoustic tweezers (11) symmetrically arranged on both sides of the gas sensor (4) along a first direction, the openings of the two acoustic tweezers (11) facing the gas sensor (4); The optical imaging module (2) comprises a sheet-shaped light source (21) arranged on one side of the gas sensor (4) along a second direction, a camera (23) arranged on the side of the gas sensor (4) away from the sheet-shaped light source (21), and a lens assembly (22) arranged between the camera (23) and the gas sensor (4), wherein a central line connecting the centers of the sheet-shaped light source (21), the gas sensor (4), the lens assembly (22) and the camera (23) forms a central axis, and an extension direction of the central axis is the second direction, and the second direction is perpendicular to the first direction. The lens assembly (22) comprises an objective lens (221), a first convex lens (222), a second convex lens (223), and a focusing lens (225) arranged in sequence along a second direction from the gas sensor (4) toward the camera (23), wherein the focal points of the first convex lens (222) and the second convex lens (223) on the sides close to each other overlap; A data processing module (3) is used to process the image information collected by the camera (23).

2. The imaging system for studying the nature of acoustic tweezers improving the sensitivity of gas sensors according to claim 1, characterized in that: A liquid lens (224) is also provided between the second convex lens (223) and the focusing lens (225).

3. The imaging system for studying the nature of acoustic tweezers improving the sensitivity of gas sensors according to claim 2, characterized in that: The sound source module (1) further comprises an adjustment component (12), wherein the adjustment component (12) is used to simultaneously adjust the distance between the two acoustic tweezers (11) and the gas sensor (4) along a first direction.

4. The imaging system for studying the nature of acoustic tweezers improving the sensitivity of gas sensors according to claim 3, characterized in that: The adjustment component (12) includes two synchronously rotating screw rods (122), the threads of the two screw rods (122) are opposite to each other, and the axis extension direction is the first direction, the two screw rods (122) are threadedly connected with nuts (123), and the outer sides of the two nuts (123) are provided with adjustment rods (124), and the two adjustment rods (124) are respectively connected to the side surfaces of the two acoustic tweezers (11), and the adjustment component (12) also includes a limiter, which is used to limit the rotation of the adjustment rod (124) around the screw rod (122).

5. The imaging system for studying the nature of acoustic tweezers improving the sensitivity of gas sensors according to claim 4, characterized in that: The limiting member comprises a limiting plate (125), a limiting groove (126) for the adjusting rod (124) to pass through is provided in the middle of the limiting plate (125), and the extending directions of the limiting plate (125) and the limiting groove (126) are both the first direction.

6. The imaging system for studying the nature of acoustic tweezers improving the sensitivity of gas sensors according to claim 5, characterized in that: The lens assembly (22) further comprises a housing (226), the two screw rods (122) are rotatably connected to the housing (226), and the limiting plate (125) is connected to the outer surface of the housing (226).

7. The imaging system for studying the nature of acoustic tweezers improving the sensitivity of gas sensors according to claim 6, characterized in that: The two screw rods (122) are detachably connected at their mutually adjacent ends via a coupling (121); a bearing (127) is sleeved on the outer surface of the coupling (121); a first connecting rod (128) connected to the outer shell (226) is disposed on the outer wall of the bearing (127); and a second connecting rod (129) connected to the outer shell (226) is disposed on the surface of one side of the middle portion of the limiting plate (125).

8. The imaging system for studying the nature of acoustic tweezers improving the sensitivity of gas sensors according to claim 1, characterized in that: The data processing module (3) comprises an image preprocessing submodule (31), an interference fringe extraction submodule (32), a fringe frequency calculation submodule (33), a gas concentration calculation submodule (34), a three-dimensional information generation submodule (35) and a gas concentration gradient submodule (36); The image preprocessing submodule (31) is used to process the image captured by the camera (23), perform noise reduction and grayscale processing on the image, and obtain a grayscale image; The interference fringe extraction submodule (32) is used to identify and process the interference fringes in the grayscale image to obtain a fringe image containing fringes with a single pixel width; The fringe frequency calculation submodule (33) is used to process the fringe image to obtain the fringe frequency of the interference fringe; The gas concentration calculation submodule (34) calculates the gas concentration value at the corresponding position based on the fringe frequency of the interference fringe according to the gas concentration and fringe frequency relationship model; The three-dimensional information generation submodule (35) combines the gas concentration value data at multiple positions to form three-dimensional information of the micro-nano structure surface interface of the gas sensor (4); The gas concentration gradient submodule (36) calculates the difference in gas concentration between adjacent positions in the three-dimensional information to obtain the gas concentration gradient distribution on the surface of the micro-nano structure of the gas sensor (4).

Images