A magnetic droplet synthesis device based on magnetic field drive

Abstract

A magnetic droplet synthesis device based on magnetic field drive relates to the field of microfluidics. Two capillaries of the flow focusing system are arranged symmetrically on both sides of the middle pipe section of the T-shaped three-way pipe, and extend into the two side pipe sections of the T-shaped three-way pipe as the inlet of the dispersed phase solution respectively. The three pipe openings of the T-shaped three-way pipe serve as the inlet of the continuous phase solution. The two bifurcated pipe sections of the Y-shaped delivery pipe in the magnetic field adjustment area form two continuous phase pipelines, which are respectively connected to the two side pipe sections of the T-shaped three-way pipe. The magnetization mechanism includes a conductive coil wound around the outside of the continuous phase pipeline and connected to the magnetic field controller. The S-shaped mixing tube is connected to the main pipe section of the Y-shaped delivery pipe. The flow focusing system is used to generate stable and continuous droplets, which enter the magnetic field adjustment area under the drive of the continuous phase solution for magnetization. After the initial fusion in the Y-shaped delivery pipe, they are further mixed through the S-shaped mixing tube. The structure is simple and the efficiency and uniformity of droplet synthesis are improved.

Description

Technical Field

[0001] The invention relates to the technical field of microfluidics, in particular to a magnetic droplet synthesis device driven by a magnetic field. Background Art

[0002] Microfluidics is an advanced technology used to control and manipulate microscale fluids. Its core lies in the use of tiny channels and fine structures to achieve precise control of the flow and mixing of liquids at the micron level. Droplet synthesis technology is a type of microfluidic technology. The basis of this technology is to efficiently operate fluids, achieve rapid mixing and reaction through low flow rates at the microscale, and greatly reduce the use of reagents and samples. In recent years, droplet synthesis technology has made significant progress. Through mechanisms such as shear force, pressure difference or fluid interfacial tension, it can efficiently generate droplets of uniform size. This fine control improves the stability and repeatability of droplet generation and is widely used in many fields such as biomedical testing, chemical reactions, and material synthesis.

[0003] At present, the common droplet synthesis technologies include microfluidic chip method, spray method and copolymer method. Among them, the microfluidic chip method can accurately control the liquid flow rate and droplet size to achieve uniform droplet generation, but the microfluidic chip fluid control system is complex, the design and manufacturing process is difficult, and it is not suitable for high-viscosity fluids. The spray method has a simple structure and high generation efficiency, but the droplet generation uniformity is poor. The copolymer method is easy to operate and can achieve precise control of droplets, but it requires a complex synthesis environment, and the synthesis cycle is long and the efficiency is low. Summary of the invention

[0004] In order to address the shortcomings of the background technology, the present invention provides a magnetic droplet synthesis device driven by a magnetic field, which uses a flow focusing system to generate stable and continuous droplets, which enter the magnetic field adjustment area for magnetization under the drive of the continuous phase solution, and are further mixed through an S-type mixing tube after initial fusion in a Y-type delivery tube. The structure is simple and the efficiency and uniformity of droplet synthesis are improved.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a magnetic droplet synthesis device driven by a magnetic field, comprising a flow focusing system, a magnetic field adjustment region and an S-shaped mixing tube, wherein the flow focusing system comprises a T-shaped three-way pipe and two capillaries, wherein the two capillaries are symmetrically arranged in parallel on both sides of the middle pipe section of the T-shaped three-way pipe, wherein the ends of the two capillaries serve as a first dispersed phase solution inlet and a second dispersed phase solution inlet respectively, and the tips of the two capillaries extend into corresponding positions of the two side pipe sections of the T-shaped three-way pipe respectively, and the three pipe openings of the T-shaped three-way pipe serve as three continuous phase solution inlets, The magnetic field adjustment area includes a Y-shaped conveying pipe and two magnetizing mechanisms. The two bifurcated pipe sections of the Y-shaped conveying pipe are arranged in parallel to form two continuous phase pipes. The two continuous phase pipes are respectively connected to the pipe sections on both sides of the T-shaped three-way pipe, and the two continuous phase pipes are respectively coaxially arranged with two capillaries. The two magnetizing mechanisms are respectively installed on the two continuous phase pipes. The magnetizing mechanisms include conductive coils wound around the outside of the continuous phase pipes. Both ends of the conductive coils are connected to a magnetic field controller to control the magnetic field strength and direction. The S-shaped mixing pipe is connected to the main pipe section of the Y-shaped conveying pipe.

[0006] Furthermore, the first dispersed phase solution inlet and the second dispersed phase solution inlet are respectively connected to a pulsation-free pump through a hose to supply two dispersed phase solutions, the two dispersed phase solutions are pre-mixed with magnetic particles, and the three continuous phase solution inlets are respectively connected to a pulsation-free pump through a hose to supply the continuous phase solution.

[0007] Furthermore, the T-shaped three-way pipe and two capillaries of the flow focusing system, the Y-shaped delivery pipe of the magnetic field adjustment area and the S-shaped mixing pipe are integrally formed of glass, and the hose connected to the pulsation-free pump is a PTFE hose.

[0008] Furthermore, the magnetic particles are Alnico nanoscale magnetic particles.

[0009] Furthermore, the S-shaped mixing tube includes alternatingly arranged mixing curved sections and gentle straight line sections.

[0010] Furthermore, magnetic field protection covers are respectively provided outside the conductive coils of the two magnetizing mechanisms.

[0011] Furthermore, the magnetic field protection cover is made of silicon steel material.

[0012] Furthermore, the conductive coil is made of nickel-copper alloy.

[0013] Furthermore, the inner diameter of the capillary is 10-100 μm.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: the device of the present invention generates stable and continuous droplets from two dispersed phase solutions mixed with magnetic particles through a flow focusing system, enters the magnetic field adjustment region under the drive of the continuous phase solution, and forms a directional magnetic field in the magnetic particles inside the magnetized droplets under the adjustment of the magnetizing mechanism. After merging through a Y-shaped conveying tube, they attract each other under the action of the magnetic field for preliminary fusion, effectively improving the application scope of fluid synthesis, and the droplets after preliminary fusion pass through an S-shaped mixing tube to extend the residence time of the droplets in the pipeline and increase the chance of contact fusion. In addition, the curved flow path of the S-shaped mixing tube can generate additional shear force and vortex, further promoting the mixing and fusion of the droplets, and improving the efficiency and uniformity of the droplet synthesis. The overall structure is simple and reasonable, and is easier to implement and apply than traditional complex fluid control systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the device of the present invention;

[0016] Figure 2 It is a schematic diagram of the flow focusing system generating droplets in the present invention;

[0017] Figure 3 It is a structural schematic diagram of the S-shaped mixing tube in the present invention.

[0018] 1. First dispersed phase solution inlet; 2. Second dispersed phase solution inlet; 3. Continuous phase solution inlet; 4. Continuous phase pipeline; 5. Conductive coil; 6. Magnetic field protection cover; 7. Magnetic field controller; 8. S-shaped mixing tube; 9. Mixing curved section; 10. Gentle straight line section. DETAILED DESCRIPTION

[0019] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, rather than 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 work are within the scope of protection of the present invention.

[0020] like Figure 1 to Figure 3 As shown, a magnetic droplet synthesis device based on magnetic field drive includes a flow focusing system, a magnetic field adjustment area and an S-shaped mixing tube 8.

[0021] Combination Figure 1As shown, the flow focusing system includes a T-shaped three-way pipe and two capillaries, the two capillaries are symmetrically arranged on both sides of the middle pipe section of the T-shaped three-way pipe, the ends of the two capillaries are respectively used as the first dispersed phase solution inlet 1 and the second dispersed phase solution inlet 2, the tips of the two capillaries are respectively extended into the corresponding positions of the two side pipe sections of the T-shaped three-way pipe, the inner diameter of the capillaries is 10-100 μm, and the three pipe openings of the T-shaped three-way pipe are used as three continuous phase solution inlets 3. Among them, the first dispersed phase solution inlet 1 and the second dispersed phase solution inlet 2 are respectively connected to a pulsation-free pump through a hose to supply two dispersed phase solutions, the two dispersed phase solutions are pre-mixed with magnetic particles, and the magnetic particles are Alnico nano-scale magnetic particles, the three continuous phase solution inlets 3 are respectively connected to a pulsation-free pump through a hose to supply the continuous phase solution, and the hose connected to the pulsation-free pump is preferably a PTFE hose, and the size, speed, mixing concentration and synthesis frequency of the droplets can be adjusted by controlling the flow rate, inlet pressure, phase viscosity and pore size.

[0022] Principles of droplet generation in flow focusing system Figure 2 As shown, the prepared dispersed phase solution is driven into the capillary by a pulsation-free pump, and the continuous phase solution is driven into the two side pipe sections of the T-shaped three-way pipe by a pulsation-free pump. The dispersed phase solution flowing out from the tip of the capillary meets the continuous phase solution from both sides at the center point and is continuously sheared under the action of the shear force of the flow and the surface tension until stable and uniform droplets are formed.

[0023] The magnetic field adjustment area includes a Y-shaped conveying pipe and two magnetizing mechanisms. The two bifurcated pipe sections of the Y-shaped conveying pipe are arranged in parallel to form two continuous phase pipes 4. The two continuous phase pipes 4 are respectively connected to the pipe sections on both sides of the T-shaped three-way pipe, and the two continuous phase pipes 4 are respectively coaxially arranged with two capillaries. The two magnetizing mechanisms are respectively installed on the two continuous phase pipes 4. The magnetizing mechanisms include a conductive coil 5 wound around the outside of the continuous phase pipe 4, which is made of nickel-copper alloy. Both ends of the conductive coil 5 are connected to a magnetic field controller 7 to control the magnetic field strength and direction.

[0024] In addition, to avoid interference from the surrounding magnetic field, a magnetic field shield 6 can be respectively provided outside the conductive coils 5 of the two magnetizing mechanisms. The area of ​​the magnetic field shield 6 is larger than that of the conductive coil 5, and is made of silicon steel material. While wrapping the conductive coil 5, it is tightly buckled on the continuous phase pipe 4, and only the connecting line between the conductive coil 5 and the magnetic field controller 7 is allowed to pass through. The area inside the magnetic field shield 6 is a controllable magnetic field area. When the conductive coil 5 is energized, electromagnetic induction will be generated and then a magnetic field will be generated. The magnetic field shield 6 can effectively shield the surrounding magnetic field from interfering with droplet synthesis. The magnetic field controller 7 can change the size of the electrical signal and the direction of the current to control the strength and direction of the magnetic field, thereby causing the magnetic particles in the droplets to generate a directional magnetic field. In order to facilitate the control of the magnetic field intensity, the diameter of the conductive coil 5 should be as small as possible, while covering most of the continuous phase pipe 4.

[0025] Combination Figure 3 As shown, the S-shaped mixing tube 8 is connected to the main section of the Y-shaped delivery pipe, and the S-shaped mixing tube 8 includes a mixing curved section 9 and a gentle straight section 10 arranged alternately, wherein the mixing curved section 9 generates vortices and recirculation due to the increase in the curvature of the pipe, which can increase the mixing efficiency of the droplets, and the relatively gentle flow condition of the gentle straight section 10 can prevent the droplets from breaking due to excessive disturbance. Therefore, the S-shaped mixing tube 8 can enhance the mixing effect by generating chaotic convection, and further improve the uniformity of the droplet mixing. In addition, the curvature of the mixing curved section 9 and the length of the gentle straight section 10 in the S-shaped mixing tube 8 can be changed according to needs to meet the needs of mixing different fluids.

[0026] In order to improve the integrity of the pipeline, the T-shaped three-way pipe and two capillaries of the flow focusing system, the Y-shaped delivery pipe of the magnetic field adjustment area and the S-shaped mixing pipe 8 are preferably formed in one piece with glass.

[0027] Before droplet synthesis, magnetic particles are first added to the two dispersed phase solutions to be synthesized and stirred sufficiently to make the magnetic particles fully dissolved in the dispersed phase solutions, so that the generated droplets have magnetism. The configured continuous phase solution and the two dispersed phase solutions are respectively driven by pulsation-free pumps to be sent into three continuous phase solution inlets 3 and the first dispersed phase solution inlet 1 and the second dispersed phase solution inlet 2. During pumping, the pulsation-free pump of the continuous phase solution is first started, and the required flow rate is set. When the continuous phase solution completely fills the pipeline and flows out, the pulsation-free pumps of the two dispersed phase solutions are turned on. When the dispersed phase solution and the continuous phase solution meet at the tips of the two capillaries, they are continuously sheared under the action of the shear force and surface tension of the flow until stable and uniform droplets are formed. The droplets generated by the two dispersed phase solutions enter their respective magnetic field adjustment areas respectively under the drive of the continuous phase solution, form a directional magnetic field through the magnetizing mechanism, and then converge at the intersection of the Y-type conveying pipe for preliminary fusion, and then generate shear force and vortex through the S-type mixing tube to complete further mixing, and finally discharged for collection.

[0028] In summary, this scheme adopts magnetic field driven droplet synthesis technology, which uses the flexibility and adjustability of the external magnetic field to control the synthesis and flow of droplets. It does not rely on complex fluid control systems and precise control mechanisms, but effectively controls the droplet synthesis process by adjusting the intensity and direction of the magnetic field. It is suitable for various fluid properties and is not easily affected by the viscosity and complexity of the fluid. It is relatively simple and easy to operate as a whole, which facilitates the rapid adjustment of parameters in the experiment to meet the changing experimental needs.

[0029] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other forms of assembly without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0030] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A magnetic droplet synthesis device driven by a magnetic field, characterized in that: The invention comprises a flow focusing system, a magnetic field adjustment region and an S-shaped mixing tube (8), wherein the flow focusing system comprises a T-shaped three-way pipe and two capillaries, wherein the two capillaries are arranged symmetrically on both sides of the middle pipe section of the T-shaped three-way pipe, the ends of the two capillaries are respectively used as a first dispersed phase solution inlet (1) and a second dispersed phase solution inlet (2), the tips of the two capillaries are respectively extended into corresponding positions of the pipe sections on both sides of the T-shaped three-way pipe, the three pipe openings of the T-shaped three-way pipe are respectively used as three continuous phase solution inlets (3), the magnetic field adjustment region comprises a Y-shaped conveying pipe and two magnetizing mechanisms, the Y-shaped Two bifurcated pipe sections of the conveying pipe are arranged in parallel to form two continuous phase pipes (4), the two continuous phase pipes (4) are respectively connected to the pipe sections on both sides of the T-shaped three-way pipe, and the two continuous phase pipes (4) are respectively arranged coaxially with the two capillaries. The two magnetizing mechanisms are respectively installed on the two continuous phase pipes (4), and the magnetizing mechanisms include a conductive coil (5) wound around the outside of the continuous phase pipe (4). Both ends of the conductive coil (5) are connected to a magnetic field controller (7) to control the intensity and direction of the magnetic field. The S-shaped mixing pipe (8) is connected to the main pipe section of the Y-shaped conveying pipe.

2. The magnetic droplet synthesis device based on magnetic field drive according to claim 1, characterized in that: The first dispersed phase solution inlet (1) and the second dispersed phase solution inlet (2) are respectively connected to a pulsation-free pump via a hose to supply two dispersed phase solutions, wherein the two dispersed phase solutions are pre-mixed with magnetic particles, and the three continuous phase solution inlets (3) are respectively connected to a pulsation-free pump via a hose to supply the continuous phase solution.

3. The magnetic droplet synthesis device based on magnetic field drive according to claim 2, characterized in that: The T-shaped three-way pipe and two capillaries of the flow focusing system, the Y-shaped delivery pipe of the magnetic field adjustment area and the S-shaped mixing pipe (8) are integrally formed of glass, and the hose connected to the pulsation-free pump is a PTFE hose.

4. The magnetic droplet synthesis device based on magnetic field drive according to claim 2, characterized in that: The magnetic particles are Alnico nano-scale magnetic particles.

5. The magnetic droplet synthesis device based on magnetic field drive according to claim 1, characterized in that: The S-shaped mixing tube (8) comprises mixing curved sections (9) and gentle straight sections (10) which are arranged alternately.

6. The magnetic droplet synthesis device based on magnetic field drive according to claim 1, characterized in that: The conductive coils (5) of the two magnetizing mechanisms are respectively covered with magnetic field protection covers (6) outside.

7. The magnetic droplet synthesis device based on magnetic field drive according to claim 6, characterized in that: The magnetic field protection cover (6) is made of silicon steel material.

8. The magnetic droplet synthesis device based on magnetic field drive according to claim 1, characterized in that: The conductive coil (5) is made of nickel-copper alloy.

9. The magnetic droplet synthesis device based on magnetic field drive according to claim 1, characterized in that: The inner diameter of the capillary is 10-100 μm.

Images