Magnetostrictive microfluidic flow channel control device

Abstract

The invention discloses a magnetostrictive microfluidic flow channel control device which comprises a substrate, inner flow channels are distributed in the substrate, a liquid inlet is formed in the end of the substrate and communicated with an inlet in the end of each inner flow channel, a liquid outlet is formed in the tail end of each branched flow channel, and a flow channel structure module is arranged on each branched flow channel. A magnetic field excitation module is arranged for each flow channel structure module, each magnetic field excitation module comprises a magnetic circuit framework, each magnetic circuit framework is provided with a socket allowing the corresponding flow channel structure module to be inserted therein, each magnetic circuit framework is sleeved with a magnet exciting coil, and each magnet exciting coil is connected with a voltage controller through a lead. The device only comprises a flow channel structure module and a magnetic field excitation module, the micro-fluidic chip is simple in structure and convenient in experiment control, the magnetic field can be adjusted and controlled through the voltage controller, stepless regulation and control of the flow channel can be realized, the flow channel of the micro-fluidic chip can be independently controlled by combining related digital control equipment, peripheral control equipment can be simplified while complex experiments can be completed, and the integration level of the device module is improved.

Description

Technical Field

[0001] The invention relates to the technical field of microfluidic chips, and in particular to a magnetostrictive microfluidic flow channel control device. Background Art

[0002] Droplet microfluidics is a technology developed in recent years on microfluidic chips to study the generation, manipulation and application of droplets ranging from a few microns to hundreds of microns. It can use microdroplets as reactors, and has the characteristics of easy independent experimental regulation and saving reaction reagents. It can effectively prevent reagent contamination. Due to the high specific surface area of ​​droplets, the speed of reagent fusion and reaction is effectively increased. Droplet microfluidics has good biochemical compatibility and can perform preset digital manipulation of droplets. In microfluidics technology, the core is to establish connections between flow channels. On this basis, microfluidic chips can integrate multiple microunits to achieve more complex experimental research. In a microfluidic channel, any fluctuation in flow rate may cause unpredictability and non-repeatability of the experiment. The commonly used flow control systems are syringe pump drive systems and pressure control systems. The pressure control system uses gas pressure to squeeze the liquid in the cavity to provide flow. The flow output characteristics are good, and there is almost no flow pulsation in the flow channel. The commonly used pressure control system is still a relatively conventional air pressure control device, which causes the entire control system to have a large volume difference compared to the microfluidic chip, making it difficult to adapt to the future development trend of integrated microfluidic chips. Moreover, in some complex microfluidic experiments, it is often necessary to control and adjust some flow channels separately, which will lead to the complication of microfluidic chip design and higher control requirements for pressure control devices. As the complexity of the chip increases significantly, it poses greater challenges to the uncontrollable factors, success rate and repeatability of the experiment. Summary of the invention

[0003] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a magnetostrictive microfluidic flow channel control device, which utilizes the good magnetic control properties of soft magnetic materials to achieve microfluidic flow channel control, improve the controllability of microfluidic chips, and meet a wider range of applications.

[0004] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a magnetostrictive microfluidic flow channel control device, comprising a substrate, an inner flow channel is distributed in the substrate, the inner flow channel forms at least one bifurcated flow channel, the end of the substrate is provided with a liquid inlet connected to the end inlet of the inner flow channel, the end of each bifurcated flow channel is provided with a liquid outlet, and a flow channel structure module is provided on each bifurcated flow channel, the flow channel structure module comprises a hard shell and a structural flow channel, the structural flow channel is located in the middle of the hard shell, and its two ends are respectively connected to the bifurcated flow channel of the inner flow channel, and the tube wall of the structural flow channel is elastic The material is made, and the shell is filled with elastomeric material. The upper side and the lower side of the structural flow channel are symmetrically filled with soft magnetic particle layers. The side of the soft magnetic particle layer facing away from the structural flow channel is in contact with the shell, and the side close to the structural flow channel is limited by a pressure plate. The soft magnetic particle layer and the pressure plate are wrapped by elastomeric material. A magnetic field excitation module is provided for each flow channel structure module, and the magnetic field excitation module includes a magnetic circuit skeleton. The magnetic circuit skeleton is provided with a socket into which the flow channel structure module can be inserted. An excitation coil is sleeved on the magnetic circuit skeleton, and the excitation coil is connected to a voltage controller through a lead.

[0005] In the above scheme: the substrate is made of a non-magnetic conductive material, and the non-magnetic conductive material is one of glass, polymethyl methacrylate, and polydimethylsiloxane.

[0006] In the above scheme: the cross-sections of the inner flow channel and its branched flow channels and structural flow channels are all circular.

[0007] In the above scheme: the soft magnetic particle layer is filled in the middle of the upper and lower sides of the structural flow channel.

[0008] In the above scheme: the shell is made of hard polymer material, and the elastic material is silicone rubber material. The shell can be made of hard material as long as it is non-magnetic. The wall of the structural flow channel is made of elastic non-magnetic material.

[0009] In the above scheme: the soft magnetic particles of the soft magnetic particle layer are particles made of high-purity iron powder or carbonyl iron powder, and the particle size is micron level.

[0010] In the above scheme: the magnetic circuit skeleton is made of pure iron or high-permeability magnetic nickel alloy material.

[0011] In the above scheme: the magnetic circuit skeleton is a C-shaped structure, the structural flow channel is inserted into its open end, the upper and lower sides correspond to the upper and lower sides of the opening of the magnetic circuit skeleton respectively, and the excitation coil is wound on the sealed side of the magnetic circuit skeleton.

[0012] In the above scheme: there are two forked flow channels on the inner flow channel, and the magnetic circuit skeleton is formed by two "["-shaped skeletons connected up and down, and the closed ends of the two "["-shaped skeletons are wrapped with excitation coils. The two ends of the two "["-shaped skeletons are respectively located on the upper and lower sides of the flow channel structure modules of the two forked flow channels, and the two groups of excitation coils are connected in parallel to lead out a group of leads connected to the voltage controller.

[0013] Beneficial effects: The microfluidic flow channel control device designed by the present invention only includes a flow channel structure module and a magnetic field excitation module; it has a simple structure and is easy to operate in experiments. The magnetic field can be adjusted and controlled by a voltage controller to achieve infinite regulation of the flow channel. The flow channel of the microfluidic chip can be controlled separately in combination with relevant digital control equipment. While completing complex experiments, it simplifies the peripheral control equipment and improves the integration of the device module. It improves the reliability of the chip experimental system and the stability of the experimental results, and also makes the experimental system easier to assemble and operate, so as to further deepen and expand the application scope of this technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a microfluidic chip containing a magnetostrictive flow channel structure module.

[0015] Figure 2 Radial cross-section diagram of the flow channel structure module.

[0016] Figure 3 Structural diagram of the split flow channel control device.

[0017] Figure 4 Structural diagram of the integrated flow channel control device.

[0018] Figure 5 Axial cross-sectional structure diagram of the flow channel structure module when it is not excited by the magnetic field.

[0019] Figure 6 Axial cross-sectional structure diagram of the flow channel structure module when it is excited by a magnetic field. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below through specific embodiments:

[0021] Example 1

[0022] like Figure 1-3 As shown, the magnetostrictive microfluidic flow channel control device includes a substrate 1. The substrate 1 is a hard substrate made of non-magnetic material, specifically glass, polymethyl methacrylate, polydimethylsiloxane and the like. A liquid inlet 2 is provided at the left end of the substrate 1. The liquid inlet 2 is an open structure for conveniently receiving experimental liquid materials. An inner flow channel 3 is distributed in the substrate 1. The inner flow channel 3 is a circular cross-section. The inner flow channel 3 forms at least one bifurcated flow channel, Figure 1The example in the figure shows two bifurcated flow channels. Of course, multiple bifurcated flow channels can also be set to expand more flow channels. The liquid inlet 2 is connected to the end inlet of the inner flow channel 3. The liquid outlet 5 is set at the end of each bifurcated flow channel. A flow channel structure module 4 is set on each bifurcated flow channel. The flow channel structure module 4 includes a hard shell 41 and a structural flow channel 42. The shell is made of a hard polymer material, etc., which is non-magnetic to ensure that it is not easy to deform. The structural flow channel 42 is located in the middle of the hard shell 41, and its two ends are respectively connected to the bifurcated flow channel of the inner flow channel. The cross-section of the structural flow channel 42 is circular. The tube wall 46 of the structural flow channel 42 is made of elastic material, which is convenient for deformation and non-magnetic. The shell 41 is filled with an elastomeric material 43, and its outer side is tightly bonded to the filled elastomeric material 43. The elastomeric material 43 can be a silicone rubber material, which is non-magnetic. The elastomeric material 43 fills the remaining space of the shell. The upper and lower sides of the structural flow channel 42 are symmetrically filled with soft magnetic particle layers 44, such as Figure 5 and 6 Preferably, the soft magnetic particle layer 44 is arranged in the middle of the upper and lower sides of the structural flow channel. The soft magnetic particles of the soft magnetic particle layer 44 are particles made of high-purity iron powder or carbonyl iron powder, and the particle size is micron-level.

[0023] The side of the soft magnetic particle layer 44 facing away from the structural flow channel 42 is in contact with the shell 41, and the side close to the structural flow channel 42 is limited by the pressure plate 45. The soft magnetic particle layer 44 and the pressure plate 45 are wrapped by the elastomer material 43, and the pressure plate 45 is made of hard non-magnetic material.

[0024] A magnetic field excitation module is provided for each flow channel structure module 4, and the magnetic field excitation module includes a magnetic circuit skeleton 6, and a socket is provided on the magnetic circuit skeleton 6 for inserting the flow channel structure module therein, and an excitation coil 7 is sleeved on the magnetic circuit skeleton 6, and the excitation coil 7 is connected to a voltage controller 9 through a lead 8. The magnetic circuit skeleton 6 is made of pure iron or a high-permeability magnetic nickel alloy material.

[0025] In this embodiment, the magnetic circuit skeleton 6 is a C-shaped structure, the left side of which is closed, and the right open end is a socket matching the flow channel structure module 4, the structural flow channel 42 is inserted into its open end, and the upper and lower sides correspond to the upper and lower sides of the opening of the magnetic circuit skeleton 6, that is, the open end of the magnetic circuit skeleton 6 is placed on the upper and lower sides of the structural flow channel 42, and the excitation coil 7 is wound on the sealed side of the magnetic circuit skeleton 6. Each excitation coil 7 leads out a group of leads 8 and is respectively connected to the voltage controller 9. Of course, the structure of the magnetic circuit skeleton 6 is not limited to the C-shaped structure, as long as other structural forms that meet the conditions are also acceptable.

[0026] When the volume and flow rate of the droplets need to be controlled during the experiment, the excitation voltages of the two voltage controllers 9 can be adjusted to generate excitation currents in the two excitation coils 7, and a corresponding magnetic field will be generated in the magnetic circuit skeleton, and magnetic poles will be formed at the ends of the skeleton. Since the flow channel structure module 4 is placed in the middle of the end of the C-shaped skeleton, it can be affected by the magnetic field perpendicular to the end. After the soft magnetic particle layer 44 in the flow channel structure module 4 is excited by the magnetic field, each soft magnetic particle will be polarized, and a strong interaction force will be generated between each other. Under the drive of the force, an orderly organizational structure will be formed along the direction of the magnetic field. Due to the mutual squeezing of the soft magnetic particles in the structure, a magnetostrictive effect is generated on a macro scale, showing a strong external force along the direction of the magnetic field. Figure 5 and Figure 6 It is an axial cross-sectional structure diagram of the flow channel structure module when it is not excited and when it is excited by the magnetic field. From the comparison diagram, it can be seen that the force will push the upper and lower pressure plates 45 to squeeze the filled elastomeric material 43 toward the middle position, thereby compressing the flow channel wall to change the cross-sectional shape and size of the structural flow channel 42, so as to realize the control of the droplet flow rate and volume size in the bifurcated flow channel of the flow channel 3 in the microfluidic chip. In this excitation mode, the corresponding bifurcated flow channel of the inner flow channel 3 can be individually controlled.

[0027] Embodiment 2, as Figure 4 As shown, the rest is the same as Example 1, except that the magnetic circuit skeleton 6 is formed by connecting two "["-shaped skeletons up and down, the closed ends of the two "["-shaped skeletons are wound with excitation coils 7, and the two ends of the two "["-shaped skeletons are respectively located at the upper and lower sides of the flow channel structure modules 4 of the two forked flow channels, and the two groups of excitation coils are connected in parallel to lead out a group of leads 8 connected to the voltage controller 9. When multiple forked flow channels are set, the structural form of the magnetic circuit skeleton 6 can also be changed, so that multiple flow channel structure modules are located in the same magnetic circuit structure.

[0028] Figure 4 The integrated magnetic field excitation mode has the same working principle as that of Example 1, the main difference being that the two flow channel structure modules 4 are placed in the same magnetic circuit structure. Under magnetic field excitation, the two flow channel structure modules will be simultaneously controlled by the same magnetic field excitation, which is suitable for scenarios where multiple flow channels are simultaneously controlled. The present invention proposes a device with separate microchannel control, which can effectively reduce the complexity of chip design and corresponding control systems, and can further improve the controllability of microfluidic experiments.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A magnetostrictive microfluidic flow channel control device, comprising a substrate (1), wherein an inner flow channel (3) is distributed in the substrate (1), wherein the inner flow channel forms at least one bifurcated flow channel, wherein a liquid inlet (2) is provided at the end of the substrate (1) and communicates with the end inlet of the inner flow channel (3), wherein a liquid outlet (5) is provided at the end of each bifurcated flow channel, wherein a flow channel structure module (4) is provided on each bifurcated flow channel, wherein the flow channel structure module (4) comprises a hard outer shell (41) and a structural flow channel (42), wherein the structural flow channel (42) is located in the middle of the hard outer shell (41), and wherein both ends of the structural flow channel (42) are respectively connected to the bifurcated flow channel of the inner flow channel, wherein the tube wall of the structural flow channel (42) is made of an elastic material, and the outer shell (41) is filled with an elastomeric material ( 43), the upper and lower sides of the structural flow channel (42) are symmetrically filled with soft magnetic particle layers (44), the side of the soft magnetic particle layer (44) facing away from the structural flow channel (42) is in contact with the shell (41), and the side close to the structural flow channel (42) is limited by a pressure plate (45), and the soft magnetic particle layer (44) and the pressure plate (45) are surrounded by an elastomeric material (43). A magnetic field excitation module is provided for each flow channel structure module (4), and the magnetic field excitation module includes a magnetic circuit skeleton (6), and the magnetic circuit skeleton (6) is provided with a socket into which the flow channel structure module can be inserted, and an excitation coil (7) is sleeved on the magnetic circuit skeleton (6), and the excitation coil (7) is connected to a voltage controller (9) through a lead wire (8).

2. The magnetostrictive microfluidic flow channel control device according to claim 1, characterized in that: The substrate (1) is made of a non-magnetic conductive material, and the non-magnetic conductive material is one of glass, polymethyl methacrylate, and polydimethylsiloxane.

3. The magnetostrictive microfluidic flow channel control device according to claim 1, characterized in that: The cross sections of the inner flow channel (3) and its bifurcated flow channel and the structural flow channel (42) are all circular.

4. The magnetostrictive microfluidic flow channel control device according to any one of claims 1 to 3, characterized in that: The soft magnetic particle layer (44) is filled in the middle of the upper and lower sides of the structural flow channel (42).

5. The magnetostrictive microfluidic flow channel control device according to claim 4, characterized in that: The shell (41) is made of a hard polymer material, and the elastic material (43) is a silicone rubber material.

6. The magnetostrictive microfluidic flow channel control device according to claim 5, characterized in that: The soft magnetic particles of the soft magnetic particle layer (44) are particles made of high-purity iron powder or carbonyl iron powder, and the particle size is in the micron level.

7. The magnetostrictive microfluidic flow channel control device according to claim 6, characterized in that: The magnetic circuit skeleton (6) is made of pure iron or a high-permeability magnetic nickel alloy material.

8. The magnetostrictive microfluidic flow channel control device according to claim 7, characterized in that: The magnetic circuit skeleton (6) is a C-shaped structure, the structural flow channel (42) is inserted into its open end, and the upper and lower sides respectively correspond to the upper and lower sides of the opening of the magnetic circuit skeleton (6), and the excitation coil (7) is wound on the sealed side of the magnetic circuit skeleton (6).

9. The magnetostrictive microfluidic flow channel control device according to claim 7, characterized in that: The inner flow channel (3) has two bifurcated flow channels, the magnetic circuit skeleton (6) is formed by two "["-shaped skeletons connected up and down, the closed ends of the two "["-shaped skeletons are wound around the excitation coil (7), the two ends of the two "["-shaped skeletons are respectively located at the upper and lower sides of the flow channel structure modules (4) of the two bifurcated flow channels, and the two groups of excitation coils are connected in parallel to lead out a group of leads connected to the voltage controller.

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