Biochemical liquid drop sample preparation device regulated and controlled by sound field and electric field

Abstract

The utility model relates to a sound field and electric field regulated biochemical liquid drop sample preparation device which comprises a base, a first support is fixedly mounted on the base, a first driving motor is fixedly mounted on the first support, a first driving wheel is rotatably mounted at the output end of the first driving motor, and a first toothed belt is fixedly connected with a Y-axis moving platform; a first driving motor rotates, and a first driving wheel drives a first toothed belt, so that the Y-axis moving platform moves in the Y direction; the two sides of the base are each provided with a supporting arm, the top ends of the two supporting arms are connected through an upper supporting arm, and second driving motors are fixedly installed on the two supporting arms. Sound waves generated by the Archimedes spiral interdigital transducer are adopted, the sound waves are focused at the nozzle when being transmitted to the tail end of the spray head, liquid drops are promoted to be broken and generated, the printing speed of the liquid drops at the nozzle is adjustable by adjusting sine alternating-current voltage parameter values, the size of the printing liquid drops is effectively controlled, and the printing efficiency is improved. The preparation of various biochemical liquid drop samples can also be realized.

Description

Technical Field

[0001] The utility model relates to the field of biochemical droplet sample preparation, in particular to a biochemical droplet sample preparation device and method controlled by an acoustic field and an electric field. Background Art

[0002] Biochemical testing provides early disease warnings and personalized health management through the analysis of biomarkers, helping to assess treatment effectiveness and promote health intervention and scientific research. It is an important means to enhance the effectiveness of comprehensive health management. Droplet microfluidics aims to construct discrete microdroplets from incompatible multiphase fluids. Because the independent nature of microdroplets ensures that biochemical reactions proceed in a compartment-like microfluidic environment, droplet microfluidics is also known as "digital microfluidics technology." Microdroplets enable the digitization and programmability of microfluidics, providing a platform for solving extremely challenging research problems in biochemical medicine. Discrete microdroplets can achieve precise control of the volume of biochemical test samples, improving the accuracy of analysis results. Therefore, biochemical droplet sample preparation is a key step in high-precision biochemical testing.

[0003] Methods for preparing droplet samples can be divided into two types: passive and active, depending on whether external energy is involved. Passive preparation methods rely on different microfluidic channel structures to prepare microdroplets through continuous shearing of the continuous phase on the dispersed phase. These methods mainly include the T-channel method, the focusing channel method, and the capillary method. Passive methods generate droplets with simple structures, fast generation speed, and low cost, but it is difficult to accurately control parameters such as the size and generation speed of the generated individual droplets in real time. Active droplet sample preparation controls the surface energy of the microfluidic by introducing external energy during the droplet generation process. These methods mainly include acoustic field-assisted methods, electric field regulation methods, thermal control methods, and mechanical control. Active droplet sample preparation can achieve on-demand preparation of droplets and precise control of droplet parameters, but it also faces the challenges of increased energy consumption, high equipment complexity, and stability and uniformity control.

[0004] Commonly used biochemical droplet samples are all prepared using microfluidic chips. The preparation process is complex, the chips are expensive and cannot be reused, which affects the efficiency of the experiment. When performing biochemical tests on digital microfluidic chips, precise droplet supply is required. The pipettes commonly used in laboratories cannot meet this requirement. The size of the droplets will affect the biochemical tests performed on digital microfluidic chips. The manufacture of precise monodisperse droplets has always been a huge manufacturing challenge. Current digital microfluidic chips are often used to control monodisperse droplets, but they have specific requirements for the type of liquid materials or reagents used, which limits their scope of application. Utility Model Content

[0005] To address these issues and develop biochemical droplet sample preparation technology, the present invention aims to provide a biochemical droplet sample preparation device and method that utilizes on-demand control of acoustic and electric fields. By utilizing the focused acoustic force of focused acoustic waves, the volume of biochemical droplet samples can be precisely manipulated, enabling the on-demand quantitative preparation of discrete droplets of biochemical reagents. The design of an electric-field-driven digital microfluidic chip allows for the precise fusion of droplets of different reagent types, enabling reagent mixing and biochemical reactions.

[0006] In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions: a biochemical droplet sample preparation device regulated by an acoustic field and an electric field, the device comprising a base, a first support fixedly mounted on the base, a first drive motor fixedly mounted on the first support, a first driving wheel rotatably mounted on the output end of the first drive motor, a first toothed belt fixedly connected to the Y-axis moving platform, the first drive motor rotates, the first driving wheel drives the first toothed belt, so that the Y-axis moving platform realizes movement in the Y direction; a support arm is mounted on both sides of the base, the top ends of the two support arms are connected by an upper support arm, a second drive motor is fixedly mounted on the two support arms, a ball screw is rotatably mounted on the output end of the second drive motor, Z The Z-axis moving platform is connected to the ball screw through a screw nut, and the second drive motor rotates, which can drive the Z-axis moving platform to move in the Z direction through the ball screw; the front surface of the Z-axis moving platform is fixedly installed with a guide rail, and the third drive motor is fixedly installed on one side of the rear surface of the Z-axis moving platform. The output end of the third drive motor passes through the Z-axis moving platform and is rotatably installed with a second driving wheel. The second toothed belt is installed on the second driving wheel. The nozzle fixture is fixedly connected to the second toothed belt, and the nozzle fixture is slidably connected to the guide rail through a slider. The third drive motor rotates and drives the second toothed belt to move through the second driving wheel, so that the nozzle fixture can move in the X direction along the guide rail; the sound focusing nozzle assembly is fixedly installed on the nozzle fixture.

[0007] Furthermore, the acoustic focusing nozzle assembly includes four nozzles, namely a first nozzle, a second nozzle, a third nozzle, and a fourth nozzle. The four nozzles have the same structure. Each nozzle includes an interdigital transducer and a conical nozzle. The conical nozzle is arranged on the lower surface of the interdigital transducer. The interdigital transducer includes a piezoelectric substrate. The upper surface of the piezoelectric substrate has a circular groove, and a first spiral electrode and a second spiral electrode are fixedly installed in the groove. The conical nozzle has a vertical flow channel and a horizontal flow channel. The vertical flow channel and the horizontal flow channel are connected, wherein the other end of the horizontal flow channel is connected to the inlet on the conical surface of the conical nozzle, and the other end of the vertical flow channel is connected to the outlet at the tip of the conical nozzle.

[0008] Furthermore, the interdigital transducer is used to generate focused sound waves, the flow channel cross-section is circular, and the diameter of the circle is 100 microns; the material of the piezoelectric substrate is lithium niobate, and the material of the first spiral electrode and the second spiral electrode are both Cr-Au, and the conical nozzle is made on the piezoelectric substrate by 3D printing.

[0009] Furthermore, the chip fixture is fixedly mounted on the Y-axis moving platform, which includes a second support, two clamping parts symmetrically fixed on both sides of the upper surface of the second support, a groove is opened in the middle of the upper surface of the second support, and two L-shaped protrusions are arranged in the groove. The two L-shaped protrusions are used to position the digital microfluidic chip.

[0010] Furthermore, the digital microfluidic chip includes a third support, on which a piezoelectric piece, an electrode layer, a dielectric layer, a hydrophobic layer, and a PDMS cavity are sequentially arranged. The piezoelectric piece is a rectangular parallelepiped; the electrode layer includes a substrate, and the electrode layer is printed on the surface of the substrate by 3D printing. The electrode layer includes nine rows and nine columns, a total of 81 electrodes, and each electrode has a zigzag shape around its periphery. The substrate is made of glass, and the electrode is made of Au; the dielectric layer is made of photoresist SU8, and the hydrophobic layer is made of perfluorodecyltrichlorosilane; the dielectric layer is 300nm thick; the hydrophobic layer is 50nm thick; as shown in FIG. Figure 12 As shown, the PDMS cavity consists of a fusion zone, a mixing zone and a storage zone. The fusion zone is provided with four openings, namely a first opening, a second opening, a third opening and a fourth opening.

[0011] Furthermore, the mixing area and the storage area are transitioned by an arc, ensuring that the mixed liquid droplets enter the storage area smoothly.

[0012] Furthermore, the first electrode in the first row is electrode 1, the second electrode in the first row is electrode 2, ..., the ninth electrode in the ninth row is electrode 81; the fusion zone is located above electrodes 7-9, 16-18, and 25-27, the first opening on the fusion zone is located above electrode 7, the second opening is located above electrode 9, the third opening is located above electrode 25, and the fourth opening is located above electrode 27; the mixing zone is located above electrodes 10-14, 19-23, 28-32, 37-41, 46-50, 55-59, 64-68, and 73-77.

[0013] A method for preparing a biochemical droplet sample with on-demand regulation of acoustic and electric fields comprises the following steps:

[0014] S1: Install digital microfluidic chip;

[0015] S2: Use a dropper to inject silicone oil into the PDMS cavity until the silicone oil fills the PDMS cavity;

[0016] S3: Connect the corresponding solution to the acoustic focusing nozzle assembly;

[0017] S4: Control droplet generation;

[0018] S5: control the droplets for mixing;

[0019] S6: preparing a plurality of mixed droplets.

[0020] Repeat S4-S5 to prepare multiple mixed droplets, which are finally stored in the storage area for use.

[0021] Furthermore, S1 is specifically:

[0022] The microfluidic chip is placed between the two L-shaped protrusions in the groove of the chip fixture and fixed with two clamps to prevent it from moving.

[0023] Furthermore, S2 is specifically:

[0024] The function of silicone oil is to suspend the mixed droplets in it. There is a difference in dielectric constant between the silicone oil and the droplets, so that the dielectrophoretic force can be used to manipulate the droplets in the silicone oil.

[0025] Furthermore, S3 is specifically:

[0026] Solution A is connected to the inlet on the conical surface of the conical nozzle of the first nozzle of the acoustic focusing nozzle assembly through injection pump A, solution B is connected to the inlet on the conical surface of the conical nozzle of the second nozzle of the acoustic focusing nozzle assembly through injection pump B, solution C is connected to the inlet on the conical surface of the conical nozzle of the third nozzle of the acoustic focusing nozzle assembly through injection pump C, and solution D is connected to the inlet on the conical surface of the conical nozzle of the fourth nozzle of the acoustic focusing nozzle assembly through injection pump D.

[0027] Furthermore, S5 is specifically:

[0028] Turn on syringe pumps A, B, C and D. Driven by the syringe pumps, the solution enters and fills the L-shaped three-dimensional flow channel. The controller controls the first, second and third drive motors to align the outlets of the four conical nozzle tips of the acoustic focusing nozzle assembly with the four openings in the fusion zone. The positive electrode of the output signal of the surface acoustic wave signal generator is connected to the spiral electrode on the interdigital transducer, and the output signal of the signal generator is adjusted to a sinusoidal continuous output. Press the "output" button of the surface acoustic wave signal generator and set the corresponding sinusoidal AC voltage output value. Under the excitation of the AC voltage signal, the interdigital transducer folds the spherical acoustic vortex to generate acoustic waves. The acoustic waves converge at the outlet of the conical nozzle tip, squeezing the liquid in the L-shaped three-dimensional flow channel to generate liquid. Among them, the first nozzle produces droplet A, the second nozzle produces droplet B, the third nozzle produces droplet C, and the fourth nozzle produces droplet D. Droplet A enters the first opening of the fusion zone, droplet B enters the second opening of the fusion zone, droplet C enters the third opening of the fusion zone, and droplet D enters the fourth opening of the fusion zone.

[0029] Furthermore, S1 is specifically:

[0030] The electrodes on the electrode layer are energized in sequence. The electric field generated by the adjacent electrodes causes an asymmetric change in the contact angle along the droplet contour, triggering the movement of the droplet. Connect the positive pole of the DC power supply to the 8th electrode, and the negative pole of the DC power supply to the 7th and 9th electrodes. Under the action of the dielectrophoretic force, droplets A and B move to the position of the 8th electrode, contact and merge into droplet E; connect the positive pole of the DC power supply to the 6th electrode, and connect the negative pole of the DC power supply to the 25th and 27th electrodes. Under the action of the dielectrophoretic force, droplets C and droplet D move to the position of the 26th electrode, contact and merge into droplet F; connect the positive pole of the DC power supply to the 17th electrode, and connect the negative pole of the DC power supply to the 8th and 26th electrodes. Under the action of the dielectrophoretic force, droplets E and droplet F move to the position of the 17th electrode, contact and merge into droplet G; connect the positive pole of the DC power supply to the 16th electrode, and connect the negative pole of the DC power supply to the 8th and 26th electrodes. The first electrode is connected to the positive pole of the DC power supply, and the 17th electrode is connected to the negative pole of the DC power supply. Under the action of the dielectrophoretic force, the droplet G moves to the position of the 16th electrode; the 15th electrode is connected to the positive pole of the DC power supply, and the 16th electrode is connected to the negative pole of the DC power supply. Under the action of the dielectrophoretic force, the droplet G moves to the position of the 15th electrode; the 14th electrode is connected to the positive pole of the DC power supply, and the 15th electrode is connected to the negative pole of the DC power supply. Under the action of the dielectrophoretic force, the droplet G moves to the position of the 14th electrode; the 13th electrode is connected to the positive pole of the DC power supply, and the 14th electrode is connected to the negative pole of the DC power supply. Under the action of the dielectrophoretic force, the droplet G moves to the position of the 13th electrode; the 12th electrode is connected to the positive pole of the DC power supply, Connect the negative pole of the DC power supply to the 13th electrode, and the droplet G moves to the position of the 12th electrode under the action of the dielectrophoretic force; connect the positive pole of the DC power supply to the 21st electrode, and connect the negative pole of the DC power supply to the 12th electrode, and the droplet G moves to the position of the 21st electrode under the action of the dielectrophoretic force; connect the positive pole of the DC power supply to the 30th electrode, and connect the negative pole of the DC power supply to the 21st electrode, and the droplet G moves to the position of the 30th electrode under the action of the dielectrophoretic force; connect the positive pole of the DC power supply to the 39th electrode, and connect the negative pole of the DC power supply to the 30th electrode, and the droplet G moves to the position of the 39th electrode under the action of the dielectrophoretic force; connect the positive pole of the DC power supply to the 48th electrode, and connect the DC power supply to the 39th electrode. The negative pole of the power supply is connected, and the droplet G moves to the position of the 48th electrode under the action of the dielectrophoretic force; the 57th electrode is connected to the positive pole of the DC power supply, and the 48th electrode is connected to the negative pole of the DC power supply, and the droplet G moves to the position of the 57th electrode under the action of the dielectrophoretic force; the 66th electrode is connected to the positive pole of the DC power supply, and the 57th electrode is connected to the negative pole of the DC power supply, and the droplet G moves to the position of the 66th electrode under the action of the dielectrophoretic force; the 75th electrode is connected to the positive pole of the DC power supply, and the 66th electrode is connected to the negative pole of the DC power supply, and the droplet G moves to the position of the 75th electrode under the action of the dielectrophoretic force; the 75th electrode is connected to the negative pole of the DC power supply, and the droplet G moves to the storage area under the action of the dielectrophoretic force.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. This utility model uses sound waves excited by an interdigital transducer. When the sound waves propagate to the end of the nozzle, they are focused at the nozzle. By adjusting the parameter value of the sinusoidal AC voltage, the droplet printing speed at the nozzle can be adjusted, thereby achieving effective control of the print droplet size.

[0033] 2. The digital microfluidic chip of the utility model is easy to clean after use and can be reused many times;

[0034] 3. The biochemical droplet sample preparation process of this utility model can accurately control the amount of reagents used to achieve efficient detection;

[0035] 4. This utility model can realize the preparation of multiple reagent droplets, as well as the fusion and mixing of multiple droplets, laying the foundation for further detection;

[0036] 5. The three-dimensional flow channel structure of the acoustic focusing nozzle assembly of the utility model can be integrated by 3D printing or laser processing, which is simple to process and easy to use;

[0037] 6. This utility model uses a three-axis motion platform to control the acoustic focusing nozzle assembly to achieve precise positioning of the droplet printing position;

[0038] 7 The dielectrophoretic force used in the present invention is particularly suitable for combination with microfluidics. Through the construction of microelectrodes, a large electric field gradient can be formed in the PDMS chamber, and the required applied voltage is low, avoiding the generation of bubbles and Joule heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is an isometric view of a biochemical droplet sample preparation device with on-demand regulation of acoustic and electric fields according to the present invention;

[0040] Figure 2 This is a rear view of a biochemical droplet sample preparation device with on-demand regulation of acoustic and electric fields according to the present invention;

[0041] Figure 3 is an axonometric view of the acoustic focusing nozzle assembly;

[0042] Figure 4 This is a front view of a single sprinkler head;

[0043] Figure 5 It is a side view of a single sprinkler head;

[0044] Figure 6 This is a top view of a single sprinkler head;

[0045] Figure 7 It is an axonometric view of a single sprinkler head;

[0046] Figure 8 is an isometric view of the chip fixture;

[0047] Figure 9 This is an exploded view of the digital microfluidic chip;

[0048] Figure 10 is an axial view of the digital microfluidic chip;

[0049] Figure 11 It is a schematic diagram of the printing position;

[0050] Figure 12 Schematic diagram of the droplet mixing principle. DETAILED DESCRIPTION

[0051] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0052] like Figure 1-2 As shown, a biochemical droplet sample preparation device regulated by acoustic and electric fields, the device includes a base 1, a first support 2 is fixedly mounted on the base 1, a first drive motor 3 is fixedly mounted on the first support 2, a first driving wheel 4 is rotatably mounted on the output end of the first driving motor 3, a first toothed belt 5 is fixedly connected to the Y-axis moving platform 6, the first driving motor 3 rotates, the first driving wheel 4 drives the first toothed belt 5, so that the Y-axis moving platform 6 can move in the Y direction; a support arm 7 is mounted on both sides of the base 1, the top ends of the two support arms 7 are connected by an upper support arm 8, a second drive motor 9 is fixedly mounted on the two support arms 7, a ball screw 10 is rotatably mounted on the output end of the second drive motor 9, a Z-axis moving platform 11 is connected to the ball screw 10 through a screw nut, the second drive motor 9 rotates, and the ball screw 10 can drive the Z-axis moving platform 11 to move in the Z direction; a guide rail 17 is fixedly mounted on the front surface of the Z-axis moving platform 11, and a third drive motor 12 is fixedly mounted on one side of the rear surface of the Z-axis moving platform 11,

[0053] The output end of the third drive motor 12 passes through the Z-axis moving platform 11 and is rotatably installed with a second active wheel 13. The second toothed belt 14 is installed on the second active wheel 13. The nozzle fixture 15 is fixedly connected to the second toothed belt 14. The nozzle fixture 15 is slidingly connected to the guide rail 17 through the slider 16. The third drive motor 12 rotates and drives the second toothed belt 14 to move through the second active wheel 13, so that the nozzle fixture 15 can move in the X direction along the guide rail 17; an acoustic focusing nozzle assembly 18 is fixedly installed on the nozzle fixture 15.

[0054] like Figure 3As shown, the acoustic focusing nozzle assembly 18 includes four nozzles, namely a first nozzle 18A, a second nozzle 18B, a third nozzle 18C and a fourth nozzle 18D. The four nozzles have the same structure. Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 As shown, each nozzle includes an IDT and a conical nozzle. The conical nozzle is located on the lower surface of the IDT. The IDT includes a piezoelectric substrate 18-1. The upper surface of the piezoelectric substrate 18-1 has a circular groove, in which a first spiral electrode 18-2 and a second spiral electrode 18-3 are fixedly mounted. The conical nozzle has a vertical flow channel 18-4 and a horizontal flow channel 18-5. The vertical flow channel 18-4 and the horizontal flow channel 18-5 are connected. The other end of the horizontal flow channel 18-5 is connected to the inlet 18-6 on the conical surface of the conical nozzle, and the other end of the vertical flow channel 18-4 is connected to the outlet 18-7 at the tip of the conical nozzle.

[0055] The interdigital transducer is used to generate focused sound waves. The flow channel cross-section is circular, and the diameter of the circle is 100 microns. The material of the piezoelectric substrate 18-1 is lithium niobate, and the material of the first spiral electrode 18-2 and the second spiral electrode 18-3 are both Cr-Au. The conical nozzle is made on the piezoelectric substrate 18-1 by 3D printing.

[0056] The chip fixture 19 is fixedly installed on the Y-axis moving platform 6, which includes a second support 19-1, two clamping parts 19-2 are symmetrically fixed on both sides of the upper surface of the second support 19-1, and a groove is opened in the middle of the upper surface of the second support 19-1. Two L-shaped protrusions 19-3 are arranged in the groove. The two L-shaped protrusions 19-3 are used to position the digital microfluidic chip 20.

[0057] like Figure 9 、 Figure 10 As shown, the digital microfluidic chip 20 includes a third support 20-1, on which a piezoelectric plate 20-2, an electrode layer 20-3, a dielectric layer 20-4, a hydrophobic layer 20-5 and a PDMS cavity 20-6 are sequentially arranged. The piezoelectric plate 20-2 is a rectangular parallelepiped; the electrode layer 20-3 includes a substrate, the surface of which is printed with an electrode layer 20-3 by 3D printing. The electrode layer includes nine rows and nine columns, a total of 81 electrodes, each electrode having a zigzag shape around its periphery. The substrate is made of glass, and the electrode is made of Au; the dielectric layer 20-4 is made of photoresist SU8, and the hydrophobic layer 20-5 is made of perfluorodecyltrichlorosilane; the dielectric layer 20-4 is 300nm thick; the hydrophobic layer 20-5 is 50nm thick; as shown Figure 12As shown, the PDMS cavity 20-6 consists of a fusion zone, a mixing zone and a storage zone. The fusion zone is provided with four openings 20-7, namely a first opening 20-7A, a second opening 20-7B, a third opening 20-7C and a fourth opening 20-7D.

[0058] The mixing area and the storage area are transitioned by an arc to ensure that the mixed liquid droplets enter the storage area smoothly.

[0059] Among them, the first electrode in the first row is electrode 1, the second electrode in the first row is electrode 2, ..., the ninth electrode in the ninth row is electrode 81; the fusion zone is located above electrodes 7-9, 16-18, and 25-27, the first opening on the fusion zone is located above electrode 7, the second opening is located above electrode 9, the third opening is located above electrode 25, and the fourth opening is located above electrode 27; the mixing zone is located above electrodes 10-14, 19-23, 28-32, 37-41, 46-50, 55-59, 64-68, and 73-77.

[0060] Example 2

[0061] A method for preparing a biochemical droplet sample with on-demand regulation of acoustic and electric fields comprises the following steps:

[0062] S1: Installing the digital microfluidic chip

[0063] The microfluidic chip 20 is placed between the two L-shaped protrusions 19 - 3 in the groove of the chip fixture 19 and fixed by two clamping members 19 - 2 to prevent it from moving.

[0064] S2: Use a dropper to inject silicone oil into the PDMS cavity until the silicone oil fills the PDMS cavity.

[0065] The function of silicone oil is to suspend the mixed droplets in it. There is a difference in dielectric constant between the silicone oil and the droplets, so that the dielectrophoretic force can be used to manipulate the droplets in the silicone oil.

[0066] S3: Connect the corresponding solution to the acoustic focusing nozzle assembly

[0067] Solution A is connected to the inlet on the conical surface of the conical nozzle of the first nozzle 18A of the acoustic focusing nozzle assembly through injection pump A, solution B is connected to the inlet on the conical surface of the conical nozzle of the second nozzle 18B of the acoustic focusing nozzle assembly through injection pump B, solution C is connected to the inlet on the conical surface of the conical nozzle of the third nozzle 18C of the acoustic focusing nozzle assembly through injection pump C, and solution D is connected to the inlet on the conical surface of the conical nozzle of the fourth nozzle 18D of the acoustic focusing nozzle assembly through injection pump D.

[0068] S4: Controlling droplet generation

[0069] Turn on the syringe pumps A, B, C and D. Driven by the syringe pumps, the solution enters and fills the L-shaped three-dimensional flow channel. The controller controls the first drive motor 3, the second drive motor 9 and the third drive motor 12. The outlets of the four conical nozzle tips of the acoustic focusing nozzle assembly 18 are aligned with the four openings of the fusion zone. The positive electrode of the output signal of the surface acoustic wave signal generator is connected to the spiral electrode on the interdigital transducer. The output signal of the signal generator is adjusted to a sinusoidal continuous output. Press the "output" button of the surface acoustic wave signal generator and set the corresponding sinusoidal alternating current. Pressure output value, the interdigital transducer folds the spherical acoustic vortex under the excitation of the AC voltage signal to generate sound waves, and the sound waves converge at the outlet of the tip of the conical nozzle, squeezing the liquid in the L-shaped three-dimensional flow channel to produce liquid, wherein the first nozzle 18A produces droplet A, the second nozzle 18B produces droplet B, the third nozzle 18C produces droplet C, and the fourth nozzle 18D produces droplet D. Droplet A enters the first opening 20-7A of the fusion zone, droplet B enters the second opening 20-7B of the fusion zone, droplet C enters the third opening 20-7C of the fusion zone, and droplet D enters the fourth opening 20-7D of the fusion zone.

[0070] S5: Controlling droplet mixing

[0071] The electrodes on the electrode layer 20-3 are energized in sequence. The electric field generated by the adjacent electrodes causes an asymmetric change in the contact angle along the droplet contour, triggering the movement of the droplet. Connect the positive pole of the DC power supply to the 8th electrode, and the negative pole of the DC power supply to the 7th and 9th electrodes. Under the action of the dielectrophoretic force, droplets A and B move toward the position of the 8th electrode, contact and merge into droplet E; connect the positive pole of the DC power supply to the 6th electrode, and connect the negative pole of the DC power supply to the 25th and 27th electrodes. Under the action of the dielectrophoretic force, droplets C and droplet D move toward the position of the 26th electrode, contact and merge into droplet F; connect the positive pole of the DC power supply to the 17th electrode, and connect the negative pole of the DC power supply to the 8th and 26th electrodes. Under the action of the dielectrophoretic force, droplets E and droplet F move toward the position of the 17th electrode, contact and merge into droplet G; connect the positive pole of the DC power supply to the 16th electrode, and connect the negative pole of the DC power supply to the 8th and 26th electrodes. The first electrode is connected to the positive pole of the DC power supply, and the 17th electrode is connected to the negative pole of the DC power supply. Under the action of the dielectrophoretic force, the droplet G moves to the position of the 16th electrode; the 15th electrode is connected to the positive pole of the DC power supply, and the 16th electrode is connected to the negative pole of the DC power supply. Under the action of the dielectrophoretic force, the droplet G moves to the position of the 15th electrode; the 14th electrode is connected to the positive pole of the DC power supply, and the 15th electrode is connected to the negative pole of the DC power supply. Under the action of the dielectrophoretic force, the droplet G moves to the position of the 14th electrode; the 13th electrode is connected to the positive pole of the DC power supply, and the 14th electrode is connected to the negative pole of the DC power supply. Under the action of the dielectrophoretic force, the droplet G moves to the position of the 13th electrode; the 12th electrode is connected to the positive pole of the DC power supply, Connect the negative pole of the DC power supply to the 13th electrode, and the droplet G moves to the position of the 12th electrode under the action of the dielectrophoretic force; connect the positive pole of the DC power supply to the 21st electrode, and connect the negative pole of the DC power supply to the 12th electrode, and the droplet G moves to the position of the 21st electrode under the action of the dielectrophoretic force; connect the positive pole of the DC power supply to the 30th electrode, and connect the negative pole of the DC power supply to the 21st electrode, and the droplet G moves to the position of the 30th electrode under the action of the dielectrophoretic force; connect the positive pole of the DC power supply to the 39th electrode, and connect the negative pole of the DC power supply to the 30th electrode, and the droplet G moves to the position of the 39th electrode under the action of the dielectrophoretic force; connect the positive pole of the DC power supply to the 48th electrode, and connect the DC power supply to the 39th electrode. The negative pole of the power supply is connected, and the droplet G moves to the position of the 48th electrode under the action of the dielectrophoretic force; the 57th electrode is connected to the positive pole of the DC power supply, and the 48th electrode is connected to the negative pole of the DC power supply, and the droplet G moves to the position of the 57th electrode under the action of the dielectrophoretic force; the 66th electrode is connected to the positive pole of the DC power supply, and the 57th electrode is connected to the negative pole of the DC power supply, and the droplet G moves to the position of the 66th electrode under the action of the dielectrophoretic force; the 75th electrode is connected to the positive pole of the DC power supply, and the 66th electrode is connected to the negative pole of the DC power supply, and the droplet G moves to the position of the 75th electrode under the action of the dielectrophoretic force; the 75th electrode is connected to the negative pole of the DC power supply, and the droplet G moves to the storage area under the action of the dielectrophoretic force.

[0072] Of course, it's also possible to energize different electrodes, first allowing droplets A and C to contact and fuse, then droplets B and D to contact and fuse, and then fuse into droplet H. The mixed droplets then move sequentially to the top of the 10th electrode, then along the 19th, 28th, 37th, 46th, 55th, 64th, and 73rd electrodes, before finally entering the storage area. There are many permutations and combinations possible, and I won't go into detail here.

[0073] S6: Preparing multiple mixed droplets

[0074] Repeat S4-S5 to prepare multiple mixed droplets, which are finally stored in the storage area for use.

[0075] The solution A is a glucose oxidase solution, the solution B is a glucose solution, the solution C is water, and the solution D is a color developing solution of tetramethylbenzidine. The finally prepared biochemical detection droplets will show different colors and are used for detecting the concentration of glucose.

[0076] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

Claims

1. A biochemical droplet sample preparation device regulated by acoustic and electric fields, the device comprising a base (1), characterized in that: A first support (2) is fixedly mounted on the base (1), a first drive motor (3) is fixedly mounted on the first support (2), a first driving wheel (4) is rotatably mounted on the output end of the first driving motor (3), a first toothed belt (5) is fixedly connected to the Y-axis moving platform (6), the first driving motor (3) rotates, the first driving wheel (4) drives the first toothed belt (5), and the Y-axis moving platform (6) moves in the Y direction; a support arm (7) is mounted on both sides of the base (1), the top ends of the two support arms (7) are connected by an upper support arm (8), and a second drive motor (9) is fixedly mounted on the two support arms (7).

2. The biochemical droplet sample preparation device controlled by acoustic and electric fields according to claim 1, characterized in that: A ball screw (10) is rotatably mounted on the output end of the second drive motor (9), and the Z-axis moving platform (11) is connected to the ball screw (10) via a screw nut. The second drive motor (9) rotates, and the ball screw (10) can drive the Z-axis moving platform (11) to move in the Z direction; a guide rail (17) is fixedly mounted on the front surface of the Z-axis moving platform (11), and the third drive motor (12) is fixedly mounted on one side of the rear surface of the Z-axis moving platform (11).

3. The biochemical droplet sample preparation device controlled by acoustic and electric fields according to claim 2, characterized in that: The output end of the third driving motor (12) passes through the Z-axis moving platform (11) and is rotatably mounted with a second driving wheel (13). The second toothed belt (14) is mounted on the second driving wheel (13). The nozzle fixture (15) is fixedly connected to the second toothed belt (14). The nozzle fixture (15) is slidably connected to the guide rail (17) via a slider (16). The third driving motor (12) rotates and drives the second toothed belt (14) to move via the second driving wheel (13), so that the nozzle fixture (15) moves in the X direction along the guide rail (17). An acoustic focusing nozzle assembly (18) is fixedly mounted on the nozzle fixture (15).

4. The biochemical droplet sample preparation device controlled by acoustic and electric fields according to claim 3, characterized in that: The acoustic focusing nozzle assembly (18) includes four nozzles, namely a first nozzle (18A), a second nozzle (18B), a third nozzle (18C) and a fourth nozzle (18D). The four nozzles have the same structure. Each nozzle includes an interdigital transducer and a conical nozzle. The conical nozzle is arranged on the lower surface of the interdigital transducer. The interdigital transducer includes a piezoelectric substrate (18-1). A circular groove is provided on the upper surface of the piezoelectric substrate (18-1). A first spiral electrode (18-2) and a second spiral electrode (18-3) are fixedly installed in the groove. A vertical flow channel (18-4) and a horizontal flow channel (18-5) are provided inside the conical nozzle. The vertical flow channel (18-4) and the horizontal flow channel (18-5) are connected, wherein the other end of the horizontal flow channel (18-5) is connected to the inlet (18-6) on the conical surface of the conical nozzle, and the other end of the vertical flow channel (18-4) is connected to the outlet (18-7) at the tip of the conical nozzle.

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