A magnetostrictive microfluidic flow channel control device

Abstract

The present invention discloses a magnetostrictive microfluidic flow channel control device, comprising a substrate, an inner flow channel distributed within the substrate, a liquid inlet provided at the end of the substrate and connected to the end inlet of the inner flow channel, a liquid outlet provided at the end of each bifurcated flow channel, a flow channel structure module provided on each bifurcated flow channel, a magnetic field excitation module provided for each flow channel structure module, the magnetic field excitation module comprising a magnetic circuit skeleton, a socket provided on the magnetic circuit skeleton for inserting the flow channel structure module therein, an excitation coil sleeved on the magnetic circuit skeleton, and the excitation coil connected to a voltage controller via a lead. The present invention only comprises a flow channel structure module and a magnetic field excitation module; the structure is simple, and experimental manipulation is convenient. The magnetic field can be adjusted and controlled by a voltage controller to achieve stepless regulation of the flow channel. The flow channel of the microfluidic chip can be independently controlled in combination with relevant digital control equipment, simplifying peripheral control equipment while completing complex experiments and improving the integration of the device modules.

Description

Technical Field

[0001] The present 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, a technique developed in recent years on microfluidic chips, is a method for generating, manipulating, and applying droplets ranging from a few microns to hundreds of microns. Using droplets as reactors, it facilitates independent experimental control, conserves reagents, and effectively prevents reagent contamination. The droplets' high specific surface area effectively increases the speed of reagent fusion and reaction. Droplet microfluidics boasts excellent biochemical compatibility and enables pre-defined digital manipulation of droplets. The core of microfluidics is establishing connections between flow channels. On this basis, microfluidic chips can integrate multiple microunits, enabling 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 at present 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. However, the commonly used pressure control system is still a relatively conventional air pressure control device, resulting in a large difference in the volume of the entire control system 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 the 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 shortcomings of the existing technology, 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 solution: 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 structure is made of a material and filled with an elastomeric material in the shell. The upper and lower sides 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 with an elastomeric material. A magnetic field excitation module is provided for each flow channel structure module. 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 the voltage controller through a lead.

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

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

[0007] In the above solution: 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 solution, the outer shell is made of a hard polymer material, and the elastomer is a silicone rubber material. Any hard material is sufficient as long as the outer shell is non-magnetic. The wall of the structural flow channel is made of an elastic, non-magnetic material.

[0009] In the above solution, the soft magnetic particles in 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 solution: the magnetic circuit skeleton is made of pure iron or high-permeability magnetic nickel alloy material.

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

[0012] In the above scheme: there are two bifurcated 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 bifurcated flow channels, and the two groups of excitation coils are connected in parallel to lead out a group of leads and are connected to the voltage controller.

[0013] Beneficial Effects: The microfluidic flow channel control device designed in this invention only includes a flow channel structure module and a magnetic field excitation module. It has a simple structure and convenient experimental control. The magnetic field can be adjusted and controlled by a voltage controller to achieve infinite control of the flow channel. It can be combined with relevant digital control equipment to independently control the flow channel of the microfluidic chip. While it can complete complex experiments, it simplifies peripheral control equipment and improves the integration of device modules. It improves the reliability of the chip experimental system and the stability of experimental results, and also makes the experimental system easier to assemble and operate, further deepening and expanding 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 excited by a magnetic field. DETAILED DESCRIPTION

[0020] The present invention will be 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, etc. A liquid inlet 2 is set at the left end of the substrate 1. The liquid inlet 2 is an open structure to facilitate the reception of experimental liquid materials. An internal flow channel 3 is distributed within the substrate 1. The internal flow channel 3 has a circular cross-section. The internal flow channel 3 forms at least one bifurcated flow channel. Figure 1The example shown 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. A 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 channels 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 and 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 disposed 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 their particle size is micron-level.

[0023] The side of the soft magnetic particle layer 44 that is back to 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] Each flow channel structure module 4 is provided with a magnetic field excitation module, which includes a magnetic circuit skeleton 6. The magnetic circuit skeleton 6 is provided with a socket for inserting the flow channel structure module. The magnetic circuit skeleton 6 is provided with an excitation coil 7, which is connected to the voltage controller 9 via a lead 8. The magnetic circuit skeleton 6 is made of pure iron or a high-permeability magnetic nickel alloy.

[0025] In this embodiment, the magnetic circuit skeleton 6 is a C-shaped structure, with its left side closed and its right open end serving as a socket for the flow channel structure module 4. The structural flow channel 42 is inserted into this open end, with its upper and lower sides corresponding to the upper and lower sides of the opening of the magnetic circuit skeleton 6. In other words, the open end of the magnetic circuit skeleton 6 rests on the upper and lower sides of the structural flow channel 42, and the excitation coil 7 is wound around the sealed side of the magnetic circuit skeleton 6. Each excitation coil 7 extends a set of leads 8, each of which is connected to a voltage controller 9. Of course, the structure of the magnetic circuit skeleton 6 is not limited to a C-shape; other structures that meet the requirements 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. The ends of the skeleton form magnetic poles. 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 along the direction of the magnetic field will be formed. Due to the mutual squeezing of the soft magnetic particles in the structure, a magnetostrictive effect is generated macroscopically, showing a strong external force along the direction of the magnetic field. Figure 5 and Figure 6 It is an axial cross-sectional structural 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 3 can be individually controlled.

[0027] Example 2, as Figure 4 As shown, the rest is the same as Example 1, except that the magnetic circuit skeleton 6 is formed by two "["-shaped skeletons connected upper and lower, with the closed ends of the two "["-shaped skeletons wrapped around the excitation coil 7. The two ends of the two "["-shaped skeletons are respectively located on the upper and lower sides of the flow channel structure modules 4 of the two bifurcated flow channels. The two sets of excitation coils are connected in parallel to lead out a set of leads 8 connected to the voltage controller 9. When multiple bifurcated flow channels are provided, the structural form of the magnetic circuit skeleton 6 can also be changed to allow multiple flow channel structure modules to be located in the same magnetic circuit structure.

[0028] Figure 4 The integrated magnetic field excitation mode works in the same principle as in Example 1, with 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 are simultaneously controlled by the same magnetic field excitation, making them suitable for scenarios where multiple flow channels are being manipulated simultaneously. By proposing a device with independent microchannel control, the present invention can effectively reduce the complexity of chip design and the corresponding control system, further improving the controllability of microfluidic experiments.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. 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 solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all 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), a liquid outlet (5) is provided at the end of each bifurcated flow channel, and a flow channel structure module (4) is provided on each bifurcated flow channel, wherein the flow channel structure module (4) comprises a hard shell (41) and a structural flow channel (42), wherein 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, wherein the tube wall of the structural flow channel (42) is made of elastic material, and the 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 elastomer material (43), and 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 (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), 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 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 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 connecting two "["-shaped skeletons up and down, the closed ends of the two "["-shaped skeletons are wound around the excitation coils (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 sets of excitation coils are connected in parallel to lead out a set of leads connected to the voltage controller.

Images