Automatic ultrasonic control device for water-based liquid drops in oil phase system

Abstract

The utility model discloses an automatic ultrasonic control device for water-based liquid drops in an oil phase system, the control process of the water-based liquid drops is completed in the oil phase system, the problem of cross contamination of sample aerosols is avoided, and meanwhile accurate control of the water-based liquid drops is achieved through the synergistic effect of a three-axis motion platform and an ultrasonic transmitting unit.

Description

Technical Field

[0001] This invention relates to the field of droplet manipulation, and in particular to an automated ultrasonic manipulation device for aqueous droplets in an oil-phase system. Background Technology

[0002] Droplet manipulation technology, with its advantages of high precision, fast response, and low energy consumption, has wide applications in fields such as biomedicine and analytical chemistry. Currently, common droplet manipulation methods include external field driving techniques such as electric fields, magnetic fields, thermal gradients, and ultrasound. Among these, ultrasonic probes for droplet manipulation offer advantages such as contactless operation, high precision, and minimal thermal effects, and have been widely applied in research areas such as sample enrichment, mixing, and atomization.

[0003] Taking common nucleic acid testing as an example, droplet manipulation technology plays several important roles in the following aspects:

[0004] (1) It enables precise sample allocation: During the solution allocation process after nucleic acid extraction, the sample containing nucleic acid can be precisely divided into multiple tiny droplets, which helps to conduct parallel detection and improve the detection throughput. (2) It helps to construct the reaction system: By manipulating the droplets, the nucleic acid sample, primers, enzymes and other reaction reagents can be accurately mixed in proportion in the tiny reaction space (droplet), so that the nucleic acid amplification and other reactions can be carried out efficiently and orderly. (3) Ultrasonic non-contact manipulation can reduce cross-contamination between samples: Each droplet is relatively independent, which can prevent the nucleic acid of different samples from contaminating each other when conducting a large number of sample tests, ensuring the accuracy of the test results.

[0005] Existing ultrasonic hydraulic control technology has the following limitations:

[0006] (1) There is a problem of cross-contamination of sample aerosols: This contamination mainly comes from the aerosols generated during droplet manipulation, namely, the fine droplet particles suspended in the air. Sample contamination can seriously affect the accuracy of experimental results in biomedical analysis that requires high sensitivity and high precision; (2) The level of intelligence is not high: At present, ultrasonic levitation technology has carried out preliminary research on automated droplet manipulation, but there are still problems such as limited droplet movement range; in addition, the droplet movement path control lacks a feedback mechanism, making it difficult to achieve intelligent path optimization for complex scenarios; (3) The manipulation precision and efficiency are not high enough: Traditional acoustic levitation single transducers can only perform a single operation when manipulating droplets, resulting in low work efficiency. Moreover, the existing ultrasonic levitation technology mainly relies on the phase modulation of the ultrasonic probe array to regulate the spatial distribution of the sound field in droplet manipulation, but there are still problems such as low droplet position control precision and insufficient manipulation flexibility. Utility Model Content

[0007] The purpose of this invention is to provide an automated ultrasonic control device for aqueous droplets in an oil phase system. The control process of the aqueous droplets is completed within the oil phase system, avoiding the problem of cross-contamination of sample aerosols. At the same time, the precise control of the aqueous droplets is achieved through the synergistic effect of the three-axis motion platform and the ultrasonic transmitting unit.

[0008] An automated ultrasonic control device for aqueous droplets in an oil-phase system, comprising:

[0009] The workbench is equipped with an oil tank containing an oil phase system, and the bottom of the oil tank is provided with a superhydrophobic surface layer.

[0010] An ultrasonic transmitting unit includes at least one ultrasonic probe, the ultrasonic transmitting unit being disposed above the oil tank and controlling the movement of water droplets by acoustic radiation force;

[0011] A three-axis motion platform is connected to drive the ultrasonic transmitting unit to move in the XYZ three-dimensional direction. In the working state, the three-axis motion platform drives the ultrasonic probe to penetrate into the oil phase system.

[0012] The control unit is connected to the three-axis motion platform and the ultrasonic transmitting unit respectively. The control unit drives the three-axis motion platform to move the ultrasonic transmitting unit to control the droplet and regulates the voltage of the ultrasonic transmitting unit.

[0013] In some preferred implementations, the ultrasonic transmitting unit includes multiple ultrasonic probes arranged in an array. The multiple ultrasonic probes are symmetrically arranged with the center higher than the sides or the center higher than the periphery. The axis of the ultrasonic transmitting unit is perpendicular to the superhydrophobic surface layer, and when the aqueous droplet is located on the axis, the distance from each ultrasonic probe to the aqueous droplet is the same.

[0014] In some preferred implementations, the ultrasonic transmitting unit includes 16 ultrasonic probes arranged in a 4x4 array.

[0015] In some preferred implementations, the automated ultrasonic control device also includes an image acquisition unit disposed below the superhydrophobic surface layer of the worktable to acquire images of the aqueous droplets.

[0016] The control unit is communicatively connected to the image acquisition unit, and the control unit is configured to identify the three-dimensional coordinates, number, and diameter of the water droplets based on the image.

[0017] The visible light transmittance of the superhydrophobic surface layer is ≥50%.

[0018] In some preferred implementations, the image acquisition unit is an industrial camera with a frame rate ≥20fps, a working distance ≥10cm between the image acquisition unit and the superhydrophobic surface layer, and a field of view ≥6*6cm at 10cm.

[0019] In some preferred implementations, when the aqueous droplets are in a suspended state, the moving speed of the ultrasonic emitting unit is 1-65 mm / s;

[0020] When the water droplets are in a non-suspended state, the moving speed of the ultrasonic transmitting unit is 1-25 mm / s.

[0021] More preferably, the volume of the aqueous droplet is 10 nL-200 μL.

[0022] In some preferred implementations, the three-axis motion platform includes a frame, an X-axis slide block, a Y-axis slide block, a Z-axis slide block, and a controller. The X-axis slide block is movably mounted on the frame along the X-axis, the Y-axis slide block is movably mounted on the X-axis slide block along the Y-axis, and the Z-axis slide block is movably mounted on the Y-axis slide block along the Z-axis and is provided with a clamping part. The ultrasonic transmitting unit is fixed to the clamping part.

[0023] The X-axis slide block, Y-axis slide block, Z-axis slide block, and control unit are respectively connected to the controller. The control unit drives the X-axis slide block, Y-axis slide block, and Z-axis slide block to move through the controller.

[0024] More preferably, the three-axis motion platform includes two X-axis slides, with the worktable positioned between the two X-axis slides.

[0025] In some preferred implementations, the oil phase system is a low-density mineral oil with a density ≤0.9 g / mL (25°C);

[0026] The static contact angle between the aqueous droplet and the superhydrophobic surface layer is ≥154°, and the roll-off angle is <3°.

[0027] In some preferred implementations, the distance between the ultrasonic transmitting unit and the superhydrophobic surface layer is 5-30 mm during operation.

[0028] This utility model has at least the following beneficial effects:

[0029] (1) Applicable to oil phase systems, avoiding aerosol contamination: The oil phase system forms a protective layer, isolating droplets from contact with the outside world, ensuring the integrity of samples in applications such as nucleic acid detection, and avoiding cross-contamination of sample aerosols.

[0030] (2) Intelligent control: The image acquisition unit and the control unit work together to identify water droplets and provide feedback on their movement path, thereby enabling water droplet path optimization, obstacle avoidance, mixing and separation operations, and improving the level of intelligent control.

[0031] (3) Automation and high efficiency: The ultrasonic transmitting unit is driven by a three-axis motion platform to improve the efficiency and flexibility of droplet manipulation, meet the needs of complex experiments, and promote the development of automated multi-droplet manipulation. Attached Figure Description

[0032] Figure 1 A three-dimensional structural diagram of the automated ultrasonic control device provided in Example 1;

[0033] Figure 2 for Figure 1 The front view;

[0034] Figure 3 This is a schematic diagram of the ultrasonic transmitting unit in Example 1;

[0035] Figure 4 This is a schematic diagram illustrating the movement of a droplet without suspension.

[0036] Figure 5 This is a schematic diagram of the movement of a suspended droplet.

[0037] Figure 6 This is a schematic diagram of droplet mixing;

[0038] The reference numerals in the figure are: 1-superhydrophobic surface layer, 2-three-axis motion platform, 21-frame, 22-X-axis slide block, 23-Y-axis slide block, 24-Z-axis slide block, 25-clamping part, 3-ultrasonic transmitting unit, 4-oil tank, 5-worktable, 6-image acquisition device, 7-lifting platform, 8-test platform. Detailed Implementation

[0039] The technical solution of this utility model will be further explained and described below through specific embodiments.

[0040] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are preferred embodiments of the present utility model and should not be considered as excluding other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0041] Unless otherwise expressly defined, in the claims, description and accompanying drawings of this utility model, the use of directional terms such as "top", "bottom", "inner", "outer", "upper", "lower", "front", "rear" to indicate orientation or positional relationship is based on the orientation and positional relationship shown in the accompanying drawings, and is only for the convenience of describing this utility model and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the specific protection scope of this utility model.

[0042] Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. In the following text, "droplet" refers to an aqueous droplet, and "sliding group" refers to an X-axis sliding group, a Y-axis sliding group, and / or a Z-axis sliding group.

[0043] Example 1

[0044] This embodiment provides an automated ultrasonic control device for aqueous droplets in an oil-phase system, which is mounted on a test platform 8, such as... Figure 1 , Figure 2 As shown, it includes a worktable 5, an image acquisition unit 6, a three-axis motion platform 2, an ultrasonic transmitting unit 3, and a control unit (not shown in the figure).

[0045] The height of the worktable 5 is designed to be 180-280mm to adapt to different operating environments. An oil tank 4 is installed on the worktable 5, containing low-density mineral oil with a density of 0.9g / mL as the oil phase system. A superhydrophobic surface layer 1 is provided at the bottom of the oil tank 4. The superhydrophobic surface layer 1 is formed by spraying and heat-treating a nanostructured superhydrophobic material. The static contact angle between the water droplet and the superhydrophobic surface is ≥154°, and the roll-off angle is <3°, which helps reduce the resistance of droplet movement on the superhydrophobic surface, thereby reducing the power consumption of ultrasonic control. Using this superhydrophobic surface layer 1, the surface energy is low, and the influence of liquid surface tension and viscosity on ultrasonic control is minimal.

[0046] An ultrasonic transmitting unit 3 is positioned above the oil tank. The ultrasonic transmitting unit 3 manipulates the droplets through acoustic radiation force, achieving either suspension or non-suspension of the droplets. When the ultrasonic waves emitted by the ultrasonic transmitting unit 3 encounter the superhydrophobic surface 11, sound wave reflection occurs, and the reflected waves are superimposed on the incident sound waves to form a reinforced ultrasonic standing wave. In this embodiment, it includes 16 ultrasonic probes arranged in a 4x4 array, with the probes arranged in a way that is higher in the middle and lower on both sides, so that the longitudinal section of the bottom surface of the ultrasonic transmitting unit 3 is... Figure 3The symmetrical parabolic structure shown has ultrasonic probes arranged symmetrically on both sides. The acoustic radiation is canceled out in the horizontal direction, and only the vertically upward acoustic radiation exists. The incident wave of the ultrasonic probe and the reflected wave of the other ultrasonic probe that is symmetrical with it mutually enhance each other to form a strengthened ultrasonic standing wave.

[0047] The axis of the ultrasonic transmitting unit 3 is perpendicular to the superhydrophobic surface layer 1 so that the sound waves can act directly on the droplet. When the water droplet is located on the axis and the distance between each ultrasonic probe and the water droplet is the same.

[0048] In this embodiment, the ultrasonic transmitting unit includes 16 ultrasonic probes arranged in a 4x4 array. In other possible implementations, the number of ultrasonic probes can be selected according to actual needs. Increasing the number of ultrasonic probes allows the ultrasonic transmitting unit to provide stronger driving force to drive the droplets, but an excessively large array may affect the operating area of ​​the three-axis motion platform, and vice versa. Preferably, the number of ultrasonic probes is controlled within a 20x20 array, i.e., no more than 400.

[0049] In this embodiment, the ultrasonic transmitting units are arranged symmetrically with a higher center and lower sides. In other possible implementations, the ultrasonic transmitting units can also be arranged with a higher center and lower sides, in which case the ultrasonic transmitting units are axially symmetrical. Alternatively, the ultrasonic probes can be directly arranged on the same horizontal plane or straight line, in which case the distance from each ultrasonic probe to the droplet is different. Or, the ultrasonic transmitting unit may include only one ultrasonic probe perpendicular to the superhydrophobic surface layer and pointing downwards.

[0050] The ultrasonic probe used in this paper is suitable for use in oil-phase systems. Such probes are not readily available commercially, but can be obtained by modifying ordinary ultrasonic probes using conventional techniques. For example, an acoustic impedance matching layer or coupling agent can be added to enable ultrasonic waves to operate in oil-phase systems. Reference can be made to examples of acoustic impedance matching layers, such as those used in high-frequency underwater acoustic transducer matching layer technology research and the preparation and performance testing of amidation-modified acoustic matching layers in air-coupled ultrasonic transducers. The focus of this application is on using this ultrasonic probe in the structure of an automated ultrasonic control device for oil-phase systems; no additional limitations are made on the processing methods of the ultrasonic probe.

[0051] Thanks to the superhydrophobic surface 11, the low surface energy significantly reduces the adhesion between the droplet and the surface. Simultaneously, the aqueous droplet exhibits a slight buoyancy advantage in low-density mineral oil. Therefore, under low-power conditions, ultrasonic standing waves can effectively control the suspension of aqueous droplets in low-density mineral oil or their non-suspended sliding on the superhydrophobic surface 11. Furthermore, in operation, the distance between the ultrasonic probe and the superhydrophobic surface layer 1 is between 5-30 mm. When the droplet is suspended, the moving speed of the ultrasonic transmitting unit 3 is controlled within the range of 1-65 mm / s. In the non-suspended state, i.e., when the droplet slides on the superhydrophobic surface layer 1, the moving speed of the ultrasonic transmitting unit 3 is adjusted to 1-25 mm / s. The three-axis motion platform 2 is responsible for driving the ultrasonic transmitting unit 3 to perform precise spatial movement, enabling it to be positioned in the X, Y, and Z coordinate axes. This platform consists of a frame 21, two parallel X-axis sliding groups 22, Y-axis sliding groups 23, and Z-axis sliding groups 24, and a controller. The X-axis slide block 22 is movable along the X-axis and is mounted on the frame 21. The Y-axis slide block 23 is movable along the Y-axis and is mounted on the X-axis slide block 22. The Z-axis slide block 24 is movable along the Z-axis and is mounted on the Y-axis slide block 23 and is provided with a clamping part 25. The ultrasonic transmitting unit 3 is clamped and fixed on the three-axis motion platform 2 by the clamping part 25.

[0052] Four precision sliding blocks can move independently to achieve precise motion control of the ultrasonic transmitting unit 3 in three dimensions. In this embodiment, the X-axis has a controllable range of 100-580mm, the Y-axis has a controllable range of 100-380mm, and the Z-axis has a controllable range of 100-480mm. Therefore, the ultrasonic transmitting unit 3, connected along three axes, can have a maximum motion space of 380×580×480mm. Furthermore, the electrical excitation signal of the ultrasonic transmitting unit 3 can be dynamically adjusted: it is energized when performing droplet lifting and droplet movement manipulation in the oil phase, and de-energized during non-droplet-manipulated motion phases and when the droplet reaches the target position and the task ends.

[0053] In this embodiment, the ultrasonic emitting unit 3 can precisely manipulate the droplet under ultrasonic excitation. Preferably, the droplet volume is in the range of 10 nanoliters (nL) to 150 microliters (μL).

[0054] By adjusting the voltage of the ultrasonic transmitting unit 3 and controlling the distance between the droplet and the ultrasonic transmitting unit 3, the capture and release of the droplet are achieved. Manipulation in low-density mineral oil significantly reduces the power consumption requirements of the equipment; only a small voltage is needed for the ultrasonic transmitting unit 3 to capture the droplet. If the goal is to suspend the droplet, the voltage of the ultrasonic transmitting unit 3 can be adjusted to exceed a certain threshold. Alternatively, even with a small droplet volume, suspension in low-density mineral oil can be easily achieved. According to the principle of acoustic wave interference enhancement, if the distance between the ultrasonic transmitting unit 3 and the superhydrophobic surface 11 is an integer multiple of half the wavelength, the incident wave and the reflected wave superimpose to form an enhanced standing wave. When the droplet is at a node position, i.e., an integer multiple of half the wavelength, it experiences acoustic radiation force. When the acoustic radiation force for an aqueous droplet exceeds a certain threshold, the droplet will overcome the downward force of gravity and surface tension, and be manipulated by the ultrasonic standing wave to suspend in the low-density mineral oil.

[0055] Image acquisition unit 6 is located below the oil tank and is mainly responsible for capturing image information of the droplets. In this embodiment, image acquisition unit 6 is mounted on a lifting platform 7, allowing for adjustable distance between it and the oil tank 4. To improve image acquisition, the superhydrophobic surface layer 1 at the bottom of the oil tank 4 has a light transmittance of ≥50% to ensure effective penetration of visible light. Furthermore, image acquisition unit 6 is communicatively connected to the control unit via a data connection cable and directly transmits the captured image data to the control unit for analysis and processing.

[0056] The image acquisition unit 6 uses an industrial-grade camera suitable for oil-phase systems. This camera has a frame rate of at least 20fps to ensure image continuity and clarity during dynamic droplet manipulation. The camera lens can be configured as fixed-focus or zoom, depending on the specific droplet manipulation requirements. The working distance between the image acquisition unit 6 and the superhydrophobic surface layer 1 is no less than 10cm, ensuring that the field of view covers an area of ​​at least 6cm × 6cm at this distance. Taking the distance from the industrial camera lens to the superhydrophobic surface layer 1 as an example, its adjustment range is between 100-180mm to adapt to different field of view and working distance requirements.

[0057] The control unit is connected to the three-axis motion platform 2 and the ultrasonic transmitting unit 3, respectively. The control unit uses a target detection network to perform in-depth image processing on the real-time images of oil-phase droplets captured by the image acquisition unit 6, thereby extracting the number, diameter, and specific coordinates of the droplets on the superhydrophobic surface layer 1. Based on this data, the control unit plans a path according to the preset droplet manipulation task and the conditions of the oil-phase environment (whether there are obstacles or other droplets, etc.). Subsequently, the control unit sends commands to the controller of the three-axis motion platform 2 to guide the ultrasonic transmitting unit 3 to move according to the planned path.

[0058] The control unit can be a computer, and the image processing involved can be implemented using conventional image processing methods of existing technology, without any limitation.

[0059] The following describes the working process of the automated ultrasonic control device:

[0060] Manipulating the non-suspended movement of droplets: See Figure 4 The control unit controls the movement of the three-axis motion platform 2, causing the ultrasonic emitting unit 3 to move directly above the target droplet A. The distance between the ultrasonic emitting unit 3 and droplet A is adjusted to a suitable value that is an integer multiple of half the wavelength. An electrical signal is applied to the ultrasonic emitting unit 3. Under the action of acoustic radiation force, the droplet's gravity and acoustic radiation force are balanced, but it does not leave the superhydrophobic surface layer 1, i.e., it is in a non-suspended state. According to the set non-suspended droplet manipulation task, the control unit sends a signal to the controller of the three-axis motion platform 2, causing the ultrasonic emitting unit 3 to drag the droplet towards the target position. After reaching the target position, the ultrasonic emitting unit 3 is de-energized, completing the non-suspended movement of the droplet.

[0061] Manipulating droplet levitation and movement: See Figure 5 The control unit controls the movement of the three-axis motion platform 2, causing the ultrasonic emitting unit 3 to move directly above the target droplet B. The distance between the ultrasonic emitting unit 3 and droplet B is adjusted to a suitable value that is an integer multiple of half the wavelength. An electrical signal is applied to the ultrasonic emitting unit 3, and under the action of acoustic radiation force, the droplet is lifted into a suspended state, leaving the superhydrophobic surface layer 1, thus entering a suspended state. According to the set suspended droplet manipulation task, the control unit sends a signal to the controller of the three-axis motion platform 2, causing the ultrasonic emitting unit 3 to drag the droplet towards the target position. After reaching the target position, the ultrasonic emitting unit 3 is de-energized, completing the suspended movement of the droplet.

[0062] Manipulating droplet mixing: See Figure 6 In the superhydrophobic surface layer 1, there is a droplet C in the area 11a to be moved, which is the object to be moved by the ultrasonic transmitting unit 3. In the non-movable area, there is a droplet D, which is the object to be mixed. The control unit controls the three-axis motion platform 2 to move the ultrasonic transmitting unit 3 to the position of droplet C. After reaching the position of droplet C, the ultrasonic transmitting unit 3 is powered on, and under the action of acoustic radiation force, droplet C can move with the ultrasonic transmitting unit 3. According to the set droplet mixing task, the control unit sends a signal to the controller of the three-axis motion platform 2, causing the ultrasonic transmitting unit 3 to drag droplet C to the position of droplet D. After reaching the position of droplet D, the ultrasonic transmitting unit 3 is de-powered, and droplet C and droplet D are mixed to form droplet E.

[0063] The real-time position of the target droplet can be obtained by image processing of the acquired images. During the process of the ultrasonic transmitting unit 3 moving above the target droplet, the control unit can determine the distance that the ultrasonic transmitting unit 3 needs to move on the x, y, and z axes based on the distance between the initial position of the ultrasonic transmitting unit 3 and the position of the target droplet. During the process of the ultrasonic transmitting unit 3 dragging the droplet, the control unit can adjust the distance that the ultrasonic transmitting unit 3 needs to move on the x, y, and z axes in real time based on the distance between the current position of the target droplet and the target position.

[0064] Example 2

[0065] This embodiment uses the automated ultrasonic manipulation device provided in Example 1 to achieve droplet mixing during enzyme activity assay. See also Figure 6 The mixing process is as follows:

[0066] On a superhydrophobic surface 11, a specific region 11a is defined as the region to be moved, containing an enzyme droplet C. In the non-movable region of this surface, a droplet D containing substrate is contained. An ultrasonic transmitting unit 3 can precisely control the movement of the enzyme droplet C, ensuring it reaches the exact position of the substrate-containing droplet D. Through this precise movement control, the mixing of the enzyme droplet C and the substrate-containing droplet D is achieved, thus completing the droplet mixing process.

[0067] Image acquisition module 6 is responsible for capturing images of the droplets within oil tank 4 and transmitting these images to the control unit. The control unit determines the spatial position of the droplets using one of two methods: either by executing an image processing algorithm or by inputting the droplet images into a pre-trained recognition model. Both methods aim to accurately acquire the three-dimensional coordinates of the droplets. The control unit then performs calculations to determine the initial positional deviation between the enzyme droplet C and the ultrasonic transmitting unit 3. Based on this calculation, the control unit further determines the required movement distance of the ultrasonic transmitting unit 3 along the X, Y, and Z axes. Subsequently, the control unit generates corresponding control signals and sends them to the three-axis motion platform 2. Upon receiving the control signals, the controller on the three-axis motion platform 2 drives the sliding blocks along each axis to move precisely, causing the ultrasonic transmitting unit 3 to partially immerse itself in oil tank 4 and precisely position itself directly above the target sample enzyme droplet C, placing the droplet C at a node position. At this position, the ultrasonic transmitting unit 3 is energized, using acoustic radiation to manipulate the enzyme droplet C, thus achieving its movement.

[0068] Based on the preset droplet mixing task parameters, the control unit will recalculate the necessary movement distance of the ultrasonic transmitting unit 3 along the X, Y, and Z axes, according to the distance between the current position coordinates of the ultrasonic transmitting unit 3 and the coordinates of the droplet D containing the substrate. This calculation process aims to achieve precise planning of the movement path of the ultrasonic transmitting unit 3. After the path planning is completed, the control unit will send corresponding command signals to the controller of the three-axis motion platform 2 to drive the ultrasonic transmitting unit 3 to precisely move the enzyme droplet C towards the predetermined position of the droplet D containing the substrate.

[0069] When enzyme droplet C successfully reaches the position of substrate-containing droplet D under the guidance of ultrasonic transmitting unit 3, ultrasonic transmitting unit 3 will be de-energized. At this point, enzyme droplet C and substrate-containing droplet D have completed mixing in the oil tank, forming a new droplet E. Finally, after confirming that enzyme droplet C and substrate-containing droplet D have successfully mixed and formed droplet E and reached the predetermined target position, ultrasonic transmitting unit 3 remains de-energized, and the entire droplet mixing process ends.

[0070] In the context of oil tank environments, droplet mixing technology can prevent the potential influence of oxygen on enzyme activity and avoid aerosol contamination of the reaction, thereby enabling more accurate determination of enzyme activity.

[0071] Example 3

[0072] This embodiment uses the automated ultrasonic manipulation device provided in Embodiment 1 to achieve droplet mixing during sample processing for nucleic acid detection. See also Figure 6 The mixing process is as follows:

[0073] On a superhydrophobic surface 11, a specific region 11a is defined as the region to be moved, containing a collected cell sample droplet C (such as a throat swab or nasal swab sample). In the non-movable region of this surface, a lysis buffer droplet D is contained. An ultrasonic transmitting unit 3 can accurately control the movement of the cell sample droplet C, ensuring it reaches the precise location of the lysis buffer droplet D. This precise movement control enables the mixing of the cell sample droplet C and the lysis buffer droplet D to release nucleic acids.

[0074] Image acquisition module 6 is responsible for capturing images of the droplets within oil tank 4 and transmitting these images to the control unit. The control unit determines the spatial position of the droplets using one of two methods: either by executing an image processing algorithm or by inputting the droplet images into a pre-trained recognition model. Both methods aim to accurately acquire the three-dimensional coordinates of the droplets. The control unit then performs calculations to determine the initial positional deviation between the cell sample droplet C and the ultrasonic transmitting unit 3. Based on this calculation, the control unit further determines the required movement distance of the ultrasonic transmitting unit 3 along the X, Y, and Z axes. Subsequently, the control unit generates corresponding control signals and sends them to the three-axis motion platform 2. Upon receiving the control signals, the controller on the three-axis motion platform 2 drives the sliding blocks along each axis to move precisely, causing the ultrasonic transmitting unit 3 to partially immerse itself in oil tank 4 and precisely position itself directly above the cell sample droplet C, placing the droplet C at a node position. At this position, the ultrasonic transmitting unit 3 is energized, using acoustic radiation to manipulate the cell sample droplet C, thus achieving its movement.

[0075] Based on the preset droplet mixing task parameters, the control unit will recalculate the necessary movement distance of the probe along the X, Y, and Z axes, according to the distance between the current position coordinates of the ultrasonic transmitting unit 3 and the coordinates of the lysis fluid droplet D. This calculation process aims to achieve precise planning of the probe's movement path. After the path planning is completed, the control unit will send corresponding command signals to the controller of the three-axis motion platform 2 to drive the ultrasonic transmitting unit 3 to precisely move the cell sample droplet C towards the predetermined position of the lysis fluid droplet D.

[0076] When cell sample droplet C successfully reaches the position of lysis buffer droplet D under the guidance of ultrasonic transmitter unit 3, ultrasonic transmitter unit 3 will be de-energized. At this point, cell sample droplet C and lysis buffer droplet D have completed mixing in the oil bath, forming a new droplet E. Finally, after confirming that cell sample droplet C and lysis buffer droplet D have successfully mixed and formed droplet E and reached the predetermined target position, ultrasonic transmitter unit 3 remains de-energized, and the entire droplet mixing process ends.

[0077] Droplet mixing technology in an oil tank provides a more controllable and automated operating environment for nucleic acid testing. Droplets in the air may become unstable due to evaporation or air flow, affecting their volume and mixing effect. Droplet mixing in an oil tank can provide more precise control over the position, volume, and mixing ratio of droplets, thereby improving the accuracy of nucleic acid testing.

[0078] The above description is only a preferred embodiment of the present utility model, and therefore cannot be used to limit the scope of the present utility model. All equivalent changes and modifications made in accordance with the scope of the present utility model patent and the contents of the specification should still fall within the scope of the present utility model.

Claims

1. An automated ultrasonic control device for aqueous droplets in an oil-phase system, characterized in that, include: The workbench is equipped with an oil tank containing an oil phase system, and the bottom of the oil tank is provided with a superhydrophobic surface layer. An ultrasonic transmitting unit includes at least one ultrasonic probe, the ultrasonic transmitting unit being disposed above the oil tank and controlling the movement of water droplets by acoustic radiation force; A three-axis motion platform is connected to drive the ultrasonic transmitting unit to move in the XYZ three-dimensional direction. In the working state, the three-axis motion platform drives the ultrasonic probe to penetrate into the oil phase system. The control unit is connected to the three-axis motion platform and the ultrasonic transmitting unit respectively. The control unit drives the three-axis motion platform to move the ultrasonic transmitting unit to control the droplet and regulates the voltage of the ultrasonic transmitting unit.

2. The automated ultrasonic control device as described in claim 1, characterized in that, The ultrasonic transmitting unit includes multiple ultrasonic probes arranged in an array. The multiple ultrasonic probes are symmetrically arranged in a form where the middle is higher than the sides or the middle is higher than the surrounding area. The axis of the ultrasonic transmitting unit is perpendicular to the superhydrophobic surface layer, and when the aqueous droplet is located on the axis, the distance from each ultrasonic probe to the aqueous droplet is the same.

3. The automated ultrasonic control device as described in claim 2, characterized in that, The ultrasonic transmitting unit includes 16 ultrasonic probes, which are arranged in a 4x4 array.

4. The automated ultrasonic control device as described in claim 1, characterized in that, It also includes an image acquisition unit, which is disposed below the superhydrophobic surface layer of the worktable to acquire images of the water droplets; The control unit is communicatively connected to the image acquisition unit, and the control unit is configured to identify the three-dimensional coordinates, the number of water droplets, and the diameter of the water droplets based on the image. The visible light transmittance of the superhydrophobic surface layer is ≥50%.

5. The automated ultrasonic control device as described in claim 4, characterized in that, The image acquisition unit is an industrial camera with a frame rate of ≥20fps. The working distance between the image acquisition unit and the superhydrophobic surface layer is ≥10cm, and the field of view at 10cm is ≥6*6cm.

6. The automated ultrasonic control device as described in claim 1, characterized in that, When the aqueous droplet is in a suspended state, the moving speed of the ultrasonic emitting unit is 1-65 mm / s; When the aqueous droplet is in a non-suspended state, the moving speed of the ultrasonic emitting unit is 1-25 mm / s.

7. The automated ultrasonic control device as described in claim 6, characterized in that, The volume of the aqueous droplet is 10 nL-200 μL.

8. The automated ultrasonic control device as described in claim 1, characterized in that, The three-axis motion platform includes a frame, an X-axis slide block, a Y-axis slide block, a Z-axis slide block, and a controller. The X-axis slide block is movably mounted on the frame along the X-axis. The Y-axis slide block is movably mounted on the X-axis slide block along the Y-axis. The Z-axis slide block is movably mounted on the Y-axis slide block along the Z-axis and is provided with a clamping part. The ultrasonic transmitting unit is fixed to the clamping part. The X-axis slide block, the Y-axis slide block, the Z-axis slide block, and the control unit are respectively connected to the controller. The control unit drives the X-axis slide block, the Y-axis slide block, and the Z-axis slide block to move through the controller.

9. The automated ultrasonic control device as described in claim 7, characterized in that, The three-axis motion platform includes two X-axis slides, and the worktable is disposed between the two X-axis slides.

10. The automated ultrasonic control device as described in claim 1, characterized in that, The oil phase system is a low-density mineral oil with a density ≤0.9g / mL (25℃); The static contact angle between the aqueous droplet and the superhydrophobic surface layer is ≥154°, and the roll-off angle is <3°.

Images