Fluid control structure and control method of T-shaped microchannel

Abstract

The invention discloses a fluid control structure and control method of a T-shaped microchannel, the T-shaped microchannel structure comprises a substrate, a T-shaped microchannel is arranged in the middle of the substrate, the T-shaped microchannel is composed of a transverse channel and a longitudinal channel, and the transverse channel and the longitudinal channel are communicated in the middle of the longitudinal channel and are perpendicular to each other. A liquid storage tank is arranged beside the longitudinal channel, and magnetorheological fluid is arranged in the liquid storage tank; four electromagnetic driving devices are arranged outside the T-shaped micro-channel, magnetic core axes of the four electromagnetic driving devices are parallel to the transverse channel and are controlled by the circuit control module to start and stop, and flowing of fluid in the T-shaped micro-channel is controlled by changing the position of magnetorheological fluid in the T-shaped micro-channel; the magnetorheological fluid is adopted as a fluid flow adjusting element, the response to an external magnetic field is fast, the inner surface of the T-shaped micro-channel is coated with the hydrophilic and oleophylic coating, the micro-channel can be completely filled with the magnetorheological fluid, adjustment of fluid flow is achieved, and the effect of adjusting and controlling the flow of the micro-channel is guaranteed.

Description

Technical Field

[0001] The invention relates to the field of fluid measurement and control, and in particular to a fluid control structure and method of a T-shaped microchannel. Background Art

[0002] Microfluidics is a discipline that has developed rapidly in the past decade based on multidisciplinary research fields. It is the science and technology of manipulating and controlling fluids at a microscopic scale. It utilizes the unique scale effect inside the microchannel and significantly enhances the reaction efficiency and accuracy in a small space, thereby achieving the goals of miniaturization, integration, rapidity and automation of the experimental process. In terms of engineering applications, microfluidics covers many fields, especially in thermal management, chemical reactions, medicine, electronics, aerospace and other industries. Microchannel technology can use micron-scale channels to efficiently control and regulate fluids. Therefore, it is very necessary to further control the flow of fluids in microchannels.

[0003] Common methods for controlling and regulating fluid flow in microchannels include mechanically driven fluid control, pressure driven fluid control, micro-bubble or droplet control methods, etc. However, existing methods still have certain limitations. First, they are used for special structures to achieve specified operating functions, which greatly limits their compatibility and applicability. Secondly, many micropumps, microvalves, and microactuators used to regulate fluid flow will increase the complexity and cost of the system, require more sophisticated design and manufacturing processes, and have poor system reliability. However, combining magnetorheological fluid with micro-microchannel fluid flow can well solve these limitations. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a fluid control structure and a control method of a T-shaped microchannel using magnetorheological fluid as a fluid flow regulating element.

[0005] In order to achieve the above-mentioned purpose, the technical solution proposed in the present invention is: a fluid control structure of a T-shaped microchannel, comprising a substrate, a T-shaped microchannel and a liquid storage tank are arranged in the substrate, and the T-shaped microchannel is composed of a transverse channel and a longitudinal channel; the transverse channel and the liquid storage tank are relatively arranged on both sides of the longitudinal channel, the liquid storage tank is connected to the longitudinal channel, and a magnetorheological fluid is arranged in the liquid storage tank; a first micro-electromagnetic drive device and a second micro-electromagnetic drive device are arranged on one side of the longitudinal channel, and the first micro-electromagnetic drive device and the second micro-electromagnetic drive device are arranged on both sides of the transverse channel, and a third micro-electromagnetic drive device and a fourth micro-electromagnetic drive device are arranged on the other side of the longitudinal channel, and the third micro-electromagnetic drive device and the fourth micro-electromagnetic drive device are arranged on both sides of the liquid storage tank; the first, second, third and fourth micro-electromagnetic drive devices are partially energized to form a magnetic field, and the magnetorheological fluid is controlled to be at different positions of the T-shaped microchannel, thereby controlling the flow of the fluid in the T-shaped microchannel.

[0006] The above technical solution is further designed as follows: the first micro-electromagnetic drive device is symmetrically arranged with the second micro-electromagnetic drive device, the first micro-electromagnetic drive device is symmetrically arranged with the fourth micro-electromagnetic drive device, the second micro-electromagnetic drive device is symmetrically arranged with the third micro-electromagnetic drive device, and the third micro-electromagnetic drive device is symmetrically arranged with the fourth micro-electromagnetic drive device; the first micro-electromagnetic drive device, the second micro-electromagnetic drive device, the third micro-electromagnetic drive device and the fourth micro-electromagnetic drive device are all close to the longitudinal channel, and all include a magnetic core shaft and a wire wound around the magnetic core shaft, and the axes of the four magnetic core shafts are all parallel to the transverse channel.

[0007] A first micro-electromagnetic drive device placement slot and a second micro-electromagnetic drive device placement slot are provided on one side of the longitudinal channel, and the first micro-electromagnetic drive device placement slot and the second micro-electromagnetic drive device placement slot are arranged on both sides of the transverse channel, and a third micro-electromagnetic drive device placement slot and a fourth micro-electromagnetic drive device placement slot are provided on the other side of the longitudinal channel, and the third micro-electromagnetic drive device placement slot and the fourth micro-electromagnetic drive device placement slot are arranged on both sides of the liquid storage tank;

[0008] The first micro-electromagnetic drive device is arranged in the first micro-electromagnetic drive device placement groove, the second micro-electromagnetic drive device is arranged in the second micro-electromagnetic drive device placement groove, the third micro-electromagnetic drive device is arranged in the third micro-electromagnetic drive device placement groove, and the fourth micro-electromagnetic drive device is arranged in the fourth micro-electromagnetic drive device placement groove.

[0009] The structure also includes a circuit control module, which includes a main power switch, a first drive switch, a second drive switch, a third drive switch, a fourth drive switch, a fifth drive switch and a sixth drive switch;

[0010] The first micro-electromagnetic drive device has a positive terminal of the first micro-electromagnetic drive device and a negative terminal of the first micro-electromagnetic drive device at both ends, the second micro-electromagnetic drive device has a positive terminal of the second micro-electromagnetic drive device and a negative terminal of the second micro-electromagnetic drive device at both ends, the third micro-electromagnetic drive device has a positive terminal of the third micro-electromagnetic drive device and a negative terminal of the third micro-electromagnetic drive device at both ends, and the fourth micro-electromagnetic drive device has a positive terminal of the fourth micro-electromagnetic drive device and a negative terminal of the fourth micro-electromagnetic drive device at both ends;

[0011] The first drive switch controls the positive electrode of the power supply to be connected to the positive terminal of the first micro-electromagnetic drive device, and the negative electrode is connected to the negative terminal of the first micro-electromagnetic drive device; the second drive switch controls the negative electrode of the power supply to be connected to the positive terminal of the first micro-electromagnetic drive device, and the positive electrode is connected to the negative terminal of the first micro-electromagnetic drive device; the sixth drive switch controls the positive electrode of the power supply to be connected to the positive terminal of the second micro-electromagnetic drive device, and the negative electrode is connected to the negative terminal of the second micro-electromagnetic drive device; the fifth drive switch controls the positive electrode of the power supply to be connected to the positive terminal of the third micro-electromagnetic drive device, and the negative electrode is connected to the negative terminal of the third micro-electromagnetic drive device; the third drive switch controls the positive electrode of the power supply to be connected to the positive terminal of the fourth micro-electromagnetic drive device, and the negative electrode is connected to the negative terminal of the fourth micro-electromagnetic drive device; the fourth drive switch controls the negative electrode of the power supply to be connected to the positive terminal of the fourth micro-electromagnetic drive device, and the positive electrode is connected to the negative terminal of the fourth micro-electromagnetic drive device.

[0012] The width of the transverse channel is equal to the width of the longitudinal channel, the width of the liquid storage tank is 1.5 times the width of the transverse channel, and the length of the liquid storage tank is equal to the width of the transverse channel.

[0013] The inner surfaces of the T-shaped microchannel and the liquid storage tank are coated with lipophilic and hydrophilic coatings. The inner surface coating of the transverse channel is arranged near one end of the longitudinal channel, and its length is 1.5 times of the width of the transverse channel. The inner surface coating of the longitudinal channel is arranged at the center, and its length is 2 times of the width of the transverse channel. The lipophilic and hydrophilic coating is arranged as a nano-silica solution modified by rich hydrophilic groups. The magnetorheological fluid is arranged as a water-based or oil-based magnetorheological fluid, and its shape is controlled by a magnetic field.

[0014] The cross sections of the transverse channel, the longitudinal channel and the liquid storage tank are all rectangular structures, and a cover plate is arranged above the transverse channel, the longitudinal channel and the liquid storage tank.

[0015] A method for controlling fluid in the T-shaped microchannel described above, wherein the method controls different switch combinations to close by a circuit control module to achieve fluid flow in different regions of the T-shaped microchannel, specifically:

[0016] (1) the circuit control module turns on the third micro-electromagnetic drive device and the fourth micro-electromagnetic drive device, and turns off the first micro-electromagnetic drive device and the fourth micro-electromagnetic drive device, that is, closes the main power switch, the fourth drive switch and the fifth drive switch, so that the magnetorheological fluid is attracted by the magnetic lines of force and accumulates in the liquid storage tank. At this time, the fluid flows in the transverse channel and the longitudinal channel;

[0017] (2) the circuit control module turns on the first micro-electromagnetic drive device and the second micro-electromagnetic drive device, and turns off the third micro-electromagnetic drive device and the fourth micro-electromagnetic drive device, that is, closes the main power switch, the second drive switch and the sixth drive switch, so that the magnetorheological fluid is attracted by the magnetic lines of force and accumulates in the micro-channel between the first micro-electromagnetic drive device and the second micro-electromagnetic drive device. At this time, the fluid flows in the longitudinal channel;

[0018] (3) the circuit control module turns on the second micro-electromagnetic drive device and the third micro-electromagnetic drive device, and turns off the first micro-electromagnetic drive device and the fourth micro-electromagnetic drive device, that is, closes the main power switch, the fifth drive switch, and the sixth drive switch, so that the magnetorheological fluid is attracted by the magnetic lines of force and accumulates in the micro-channel between the second micro-electromagnetic drive device and the third micro-electromagnetic drive device. At this time, the fluid flows in the transverse channel and the longitudinal channel;

[0019] (4) The circuit control module turns on the first micro-electromagnetic drive device and the fourth micro-electromagnetic drive device, and turns off the second micro-electromagnetic drive device and the third micro-electromagnetic drive device, that is, closes the main power switch, the first drive switch and the third drive switch, so that the magnetorheological fluid is attracted by the magnetic lines of force and accumulates in the micro-channel between the first micro-electromagnetic drive device and the fourth micro-electromagnetic drive device. At this time, the fluid flows in the transverse channel and the longitudinal channel.

[0020] The beneficial effects of the present invention are:

[0021] The present invention adopts magnetorheological fluid as a fluid flow regulating element, which has a fast response to an external magnetic field, and by coating a hydrophilic and lipophilic coating on the inner surface of a T-shaped microchannel, the magnetorheological fluid can completely fill the microchannel, realize the switching of each flow path in the channel, realize the regulation of fluid flow, and ensure the effect of regulating the flow of the microchannel; the use of magnetorheological fluid to regulate the channel flow can adapt to the flow conditions under different working conditions, and ensure that the entire system can operate normally under various working conditions; since the magnetorheological fluid is used as the fluid flow regulating element, there is no mechanical element inside the T-shaped microchannel, which helps to ensure that the flow in the channel is smooth and continuous, and reduces unnecessary energy loss, reduces wear and failure rate inside the channel, thereby reducing maintenance costs and increasing the service life of the channel; a circuit control module is set to control the micro electromagnetic drive device, which is convenient to operate and responds quickly, and the adjustment circuit controls the magnetic field strength, has strong adaptability to working conditions, and is easy to replace.

[0022] The present invention uses magnetorheological fluid as a fluid flow regulating element. The magnetorheological fluid can control the flow rate or flow resistance through the control of an external magnetic field without direct contact with the fluid itself. This non-contact control method avoids wear and corrosion of mechanical parts and is particularly suitable for control scenarios in microchannels of extremely small sizes, which can greatly improve the stability and reliability of the system. The flow in a microchannel may be very complex, including turbulence, shear flow, etc. The flow resistance in the microchannel is adjusted by the rheological characteristics of the magnetorheological fluid under the action of a magnetic field, which can effectively alleviate the flow problems caused by the size of the microchannel. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0024] Figure 2 It is a schematic diagram of the structure of the present invention when it is not powered on;

[0025] Figure 3 is a schematic diagram of the coating structure on the inner surface of the micro-channel;

[0026] Figure 4 is a schematic diagram of the connection of the circuit control module of the present invention;

[0027] Figure 5 It is a schematic diagram of the structure of the transverse channel and the longitudinal channel of the present invention when they are flowing;

[0028] Figure 6 It is a schematic diagram of the magnetic circuit when the transverse channel and the longitudinal channel of the present invention flow;

[0029] Figure 7 This is a schematic diagram of the structure of the longitudinal channel of the present invention when it is flowing;

[0030] Figure 8 It is a schematic diagram of the magnetic circuit when the longitudinal channel of the present invention flows;

[0031] Fig. 9 It is a schematic diagram of the structure of the transverse channel and the longitudinal channel (1-B<—>5-C) of the present invention when flowing;

[0032] Fig.10 It is a schematic diagram of the magnetic circuit when the transverse channel and the longitudinal channel (1-B<—>5-C) of the present invention flow;

[0033] Fig.11 It is a schematic diagram of the structure of the transverse channel and the longitudinal channel (1-B<—>5-D) of the present invention when flowing;

[0034] Fig.12 It is a schematic diagram of the magnetic circuit when the transverse channel and the longitudinal channel (1-B<—>5-D) of the present invention are flowing.

[0035] Meanings of the reference numerals in the figure: 1. transverse channel, 2. positive terminal of the second micro-electromagnetic drive device, 3. second micro-electromagnetic drive device, 4. negative terminal of the second micro-electromagnetic drive device, 5. longitudinal channel, 6. positive terminal of the third micro-electromagnetic drive device, 7. third micro-electromagnetic drive device, 8. negative terminal of the third micro-electromagnetic drive device, 9. liquid storage tank, 10. magnetorheological fluid, 11. negative terminal of the fourth micro-electromagnetic drive device, 12. fourth micro-electromagnetic drive device, 13. positive terminal of the fourth micro-electromagnetic drive device, 14. negative terminal of the first micro-electromagnetic drive device, 15. first micro-electromagnetic drive device, 16. positive terminal of the first micro-electromagnetic drive device, 17. cover plate, 18. substrate, 19. circuit control module, 20. placement groove of the first micro-electromagnetic drive device, 21. placement groove of the second micro-electromagnetic drive device, 22. placement groove of the third micro-electromagnetic drive device, 23. placement groove of the fourth micro-electromagnetic drive device, 24. coating. DETAILED DESCRIPTION

[0036] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Embodiment 1

[0038] Combination Figure 1 and Figure 2 As shown, the fluid control structure of the T-type microchannel of this embodiment includes a substrate 18, in which a T-type microchannel is provided, and the T-type microchannel is composed of a transverse channel 1 and a longitudinal channel 5, wherein the end points of the transverse channel 1 are A and B, the end points of the longitudinal channel 5 are C and D, and the connecting point of the transverse channel 1 and the longitudinal channel 5 is B; a liquid storage tank 9 connected to the longitudinal channel 5 is provided on the side of the longitudinal channel 5 opposite to the transverse channel 1, that is, the liquid storage tank 9 and the transverse channel 1 are arranged on both sides of the longitudinal channel 5, a magnetorheological fluid 10 is arranged in the liquid storage tank 9, a first micro-electromagnetic drive device placement groove 20 and a second micro-electromagnetic drive device placement groove 21 are provided on one side of the longitudinal channel 5, and the first micro-electromagnetic drive device placement groove 20 and the second micro-electromagnetic drive device placement groove 21 are arranged on both sides of the transverse channel 1, and a third micro-electromagnetic drive device placement groove 22 and a fourth micro-electromagnetic drive device placement groove 23 are provided on the other side of the longitudinal channel 5, and the third micro-electromagnetic drive device placement groove 22 and the fourth micro-electromagnetic drive device placement groove 23 are arranged on both sides of the liquid storage tank 9.

[0039] The width of the transverse channel 1 is equal to the width of the longitudinal channel 5, which is w. The depth of the transverse channel 1 is equal to the depth of the longitudinal channel 5, which is d. The length of (1-B<—>5-C) and the length of (1-B<—>5-D) in the longitudinal channel 5 are equal to c. The width of the liquid storage tank 9 is 1.5 times the width of the transverse channel 1, and its width e is 1.5w. The depth is equal to the depth of the transverse channel 1, which is d. The length of the liquid storage tank 9 is equal to the width of the transverse channel 1, which is w.

[0040] like Figure 3 As shown, the inner surface of the liquid storage tank 9 is coated with a coating, the magnetorheological fluid 10 is set to be one of a water-based or oil-based magnetorheological fluid 10, the shape is controlled by a magnetic field, the coating length of the transverse channel 1 is 1.5w, the coating lengths of (1-B<—>5-C) and (1-B<—>5-D) in the longitudinal channel 5 are the same, set to 2w, the coating is set to be an oleophilic and hydrophilic coating 24, and the oleophilic and hydrophilic coating 24 is set to be a hydrophilic group-rich modified nano-silica sol. The oleophilic and hydrophilic coating 24 allows the magnetorheological fluid 10 to be well combined with the wall of the transverse channel 1 and the longitudinal channel 5, ensuring that the magnetorheological fluid changes the fluid flow effect in the channel.

[0041] When the fluid is gas, either water-based or oil-based magnetorheological fluid 10 can be selected, and the base liquid of the selected magnetorheological fluid 10 should not be miscible with the gas selected by the fluid; when the fluid is liquid, the base liquid of the magnetorheological fluid 10 should not be miscible with the liquid selected by the fluid.

[0042] Initially, the magnetorheological fluid 10 is arranged in the liquid storage tank 9 and fills the internal volume. A third micro-electromagnetic drive device placement slot 22 is arranged on one side of the liquid storage tank 9 and the longitudinal channel 5, and a fourth micro-electromagnetic drive device placement slot 23 is arranged on one side. The accumulation length of the magnetorheological fluid 10 in the transverse channel 1 is e, and the transverse channel length l is set to 5e. The accumulation length of the magnetorheological fluid 10 in the longitudinal channels 5 (1-B<—>5-C) and (1-B<—>5-D) is e, and the length c is set to 2e.

[0043] A cover plate 17 is arranged above the transverse channel 1, the longitudinal channel 5 and the liquid storage tank 9, thereby forming a closed flow channel together with the base plate 18. A first micro-electromagnetic drive device placement groove 20 is arranged on one side of the transverse channel 1 and the longitudinal channel 5, and a second micro-electromagnetic drive device placement groove 21 is arranged on one side. A third micro-electromagnetic drive device placement groove 22 is arranged on one side of the liquid storage tank 9 and the longitudinal channel 5, and a fourth micro-electromagnetic drive device placement groove 23 is arranged on one side.

[0044] A first micro-electromagnetic drive device 15 is horizontally arranged in the first micro-electromagnetic drive device placement groove 20, and a first micro-electromagnetic drive device positive terminal 16 is arranged at the left end of the first micro-electromagnetic drive device 15, and a first micro-electromagnetic drive device negative terminal 14 is arranged at the right end. A second micro-electromagnetic drive device 3 is horizontally arranged in the second micro-electromagnetic drive device placement groove 21, and a second micro-electromagnetic drive device positive terminal 2 is arranged at the left end of the second micro-electromagnetic drive device 3, and a second micro-electromagnetic drive device negative terminal 4 is arranged at the right end. A third micro-electromagnetic drive device 7 is horizontally arranged in the third micro-electromagnetic drive device placement groove 22, and a third micro-electromagnetic drive device positive terminal 6 is arranged at the left end of the third micro-electromagnetic drive device 7, and a third micro-electromagnetic drive device negative terminal 8 is arranged at the right end. A fourth micro-electromagnetic drive device 12 is horizontally arranged in the fourth micro-electromagnetic drive device placement groove 23, and a fourth micro-electromagnetic drive device positive terminal 11 is arranged at the left end of the fourth micro-electromagnetic drive device 12, and a fourth micro-electromagnetic drive device negative terminal 11 is arranged at the right end. The four micro-electromagnetic drive devices are all close to the longitudinal channel 5.

[0045] The first micro-electromagnetic drive device 15 is symmetrically arranged with the second micro-electromagnetic drive device 3, the first micro-electromagnetic drive device 15 is symmetrically arranged with the fourth micro-electromagnetic drive device 12, the second micro-electromagnetic drive device 3 is symmetrically arranged with the third micro-electromagnetic drive device 7, and the third micro-electromagnetic drive device 7 is symmetrically arranged with the fourth micro-electromagnetic drive device 12. The magnetic core axes of the first micro-electromagnetic drive device 15, the second micro-electromagnetic drive device 3, the third micro-electromagnetic drive device 7 and the fourth micro-electromagnetic drive device 12 are all parallel to the transverse channel 1.

[0046] Combination Figure 4 As shown, this embodiment is also provided with a circuit control module 19 for controlling the opening and closing of the first micro-electromagnetic driving device 15, the second micro-electromagnetic driving device 3, the third micro-electromagnetic driving device 7 and the fourth micro-electromagnetic driving device 12 to form vertical or horizontal magnetic lines to control the fluid flow in the T-shaped microchannel.

[0047] The circuit control circuit of the circuit control module 19 mainly includes a main power switch SB0, a switch SB1 of the first micro-electromagnetic drive device 15 controls the positive pole of the power supply to be connected to the positive terminal 16 of the first micro-electromagnetic drive device, and the negative pole is connected to the negative terminal 14 of the first micro-electromagnetic drive device, a switch SB2 of the first micro-electromagnetic drive device 15 controls the negative pole of the power supply to be connected to the positive terminal 16 of the first micro-electromagnetic drive device, and the positive pole is connected to the negative terminal 14 of the first micro-electromagnetic drive device, and a switch SB6 of the second micro-electromagnetic drive device 3 controls the positive pole of the power supply to be connected to the positive terminal 2 of the second micro-electromagnetic drive device, and the positive pole is connected to the negative terminal 14 of the first micro-electromagnetic drive device. The negative terminal 4 of the micro-electromagnetic drive device, the switch SB5 of the third micro-electromagnetic drive device 7 controls the positive pole of the power supply to be connected to the positive terminal 6 of the third micro-electromagnetic drive device, and the negative pole is connected to the negative terminal 8 of the third micro-electromagnetic drive device, the switch SB3 of the fourth micro-electromagnetic drive device 12 controls the positive pole of the power supply to be connected to the positive terminal 13 of the fourth micro-electromagnetic drive device, and the negative pole is connected to the negative terminal 11 of the fourth micro-electromagnetic drive device, the switch SB4 of the fourth micro-electromagnetic drive device 1 controls the negative pole of the power supply to be connected to the positive terminal 13 of the fourth micro-electromagnetic drive device, and the positive pole is connected to the negative terminal 11 of the fourth micro-electromagnetic drive device.

[0048] Embodiment 2

[0049] This embodiment provides a fluid control method for the T-shaped microchannel described in the first embodiment. The method controls four micro-electromagnetic drive devices to change the control of the magnetorheological fluid 10 through the circuit control module 19, specifically including:

[0050] (1) Figure 5 and Figure 6 As shown, when the transverse channel 1 and the longitudinal channel 5 are in circulation, that is, the fluid flows in the flow channel (1-A<—>1-B<—>5-C, 5-D), the main power switch (SB0) is turned off in the circuit control module 19, the switch of the third micro-electromagnetic drive device 7 (SB5) and the fourth micro-electromagnetic drive device 12 (SB4) are turned off, and the switch of the first micro-electromagnetic drive device 15 (SB1, SB2), the switch of the second micro-electromagnetic drive device 3 (SB6) and the fourth micro-electromagnetic drive device 12 (SB3) are turned on, so that the magnetorheological fluid 10 is attracted by the magnetic lines of force and accumulates in the liquid storage tank 9. At this time, the magnetic force lines formed between the third micro-electromagnetic drive device 7 and the fourth micro-electromagnetic drive device 12 are arranged perpendicular to the flow direction of the fluid in the transverse channel 1, and the fluid medium passing through the transverse channel 1 and the longitudinal channel 5 exerts a friction force along the flow direction on the magnetorheological fluid 10. The resultant force of the magnetic field force of the third micro-electromagnetic drive device 7 and the fourth micro-electromagnetic drive device 12 acting on the magnetorheological fluid 10, the surface tension of the liquid storage tank 9, and the pressure of the fluid acting on the free surface of the magnetorheological fluid 10 is balanced with the friction force between the fluid and the magnetorheological fluid 10, and the magnetorheological fluid 10 is in a static and stable state;

[0051] (2) Figure 7 and Figure 8 As shown, when the longitudinal channel 5 flows, that is, the fluid flows in the flow channel (5-C<—>1-B<—>5-D), the main power switch (SB0) is turned off in the circuit control module 19, the switch of the first micro-electromagnetic drive device 15 (SB2) and the switch of the second micro-electromagnetic drive device 3 (SB6) are turned off, and the switch of the first micro-electromagnetic drive device 15 (SB1), the switch of the third micro-electromagnetic drive device 8 (SB5) and the fourth micro-electromagnetic drive device 12 (SB3, SB4) are turned on, and the rheological fluid 11 is attracted by the magnetic lines of force and thus accumulates in the transverse channel 1. At this time, the magnetic lines of force formed between the first micro-electromagnetic drive device 15 and the second micro-electromagnetic drive device 3 are arranged perpendicular to the flow direction of the fluid in the transverse channel 1, and the fluid medium in the longitudinal channel 5 exerts a friction force on the magnetorheological fluid 10 along the flow direction. The resultant force of the magnetic field force of the first micro-electromagnetic drive device 15 and the second micro-electromagnetic drive device 3 on the magnetorheological fluid 10 and the surface tension of the transverse channel 1 are balanced with the friction between the fluid and the magnetorheological fluid 10, and the magnetorheological fluid 10 is in a static and stable state;

[0052] (3) Fig. 9 and Fig.10 As shown, when the channel 1 and the longitudinal channel 5 (1-B<—>5-C) are in communication, that is, the fluid flows in the flow channel (1-A<—>1-B<—>5-C), the circuit control module 19 turns off the main power switch (SB0), turns off the switch of the second micro-electromagnetic drive device 3 (SB6) and the switch of the third micro-electromagnetic drive device 7 (SB5), turns on the switch of the first micro-electromagnetic drive device 15 (SB1, SB2), and the fourth micro-electromagnetic drive device 12 (SB3, SB4), so that the magnetorheological fluid 10 is attracted by the magnetic lines of force and accumulates in the longitudinal channel 5 (1- B<—>5-D), at this time, the magnetic lines of force formed between the second micro-electromagnetic drive device 3 and the third micro-electromagnetic drive device 7 are arranged horizontally with the flow direction of the fluid in the transverse channel 1, and the fluid medium through the transverse channel 1 and the longitudinal channel 5 (1-B-5-C) exerts a friction force along the flow direction on the magnetorheological fluid 10, and the magnetic field force of the second micro-electromagnetic drive device 3 and the third micro-electromagnetic drive device 7 acting on the magnetorheological fluid 10, the surface tension of the longitudinal channel 1B-5D and the friction force between the fluid and the magnetorheological fluid 10 are balanced, and the magnetorheological fluid 10 is in a static and stable state;

[0053] (4) Fig.11 and Fig.12As shown, when the transverse channel 1 and the longitudinal channel 5 (1-B<—>5-D) are in circulation, that is, the fluid flows in the flow channel (1-A<—>1-B<—>5-D), the main power switch (SB0) is turned off in the circuit control module 19, the switch of the first micro-electromagnetic drive device 15 (SB1) and the fourth micro-electromagnetic drive device 12 (SB3) are turned off, and the switch of the first micro-electromagnetic drive device 15 (SB2), the switch of the second micro-electromagnetic drive device 3 (SB6), the switch of the third micro-electromagnetic drive device 7 (SB5) and the fourth micro-electromagnetic drive device 12 (SB4) are turned on, so that the magnetorheological fluid 10 is attracted by the magnetic lines of force and accumulates. In the longitudinal channel 5 (1-B<—>5-C), at this time, the magnetic lines of force formed between the first micro-electromagnetic drive device 15 and the fourth micro-electromagnetic drive device 12 are arranged horizontally with the flow direction of the fluid in the transverse channel 1, and the fluid medium through the main transverse channel 1 and the longitudinal channel 5 (1-B<—>5-D) exerts a friction force on the magnetorheological fluid 10 along the flow direction. The magnetic field force of the first micro-electromagnetic drive device 15 and the fourth micro-electromagnetic drive device 12 acting on the magnetorheological fluid 10, the surface tension of the longitudinal channel 5 (1-B<—>5-C) and the friction force between the fluid and the magnetorheological fluid 10 are balanced, and the magnetorheological fluid 10 is in a static and stable state.

[0054] The technical solutions of the present invention are not limited to the above-mentioned embodiments, and any technical solutions obtained by equivalent replacement methods fall within the scope of protection required by the present invention.

Claims

1. A fluid control structure of a T-shaped microchannel, comprising a substrate (18), characterized in that: The substrate (18) is provided with a T-shaped microchannel and a liquid storage tank (9), wherein the T-shaped microchannel is composed of a transverse channel (1) and a longitudinal channel (5); the transverse channel (1) and the liquid storage tank (9) are arranged on opposite sides of the longitudinal channel (5); the liquid storage tank (9) is connected to the longitudinal channel (5); a magnetorheological fluid (10) is arranged in the liquid storage tank (9); a first micro-electromagnetic drive device (15) and a second micro-electromagnetic drive device (3) are arranged on one side of the longitudinal channel (5); the first micro-electromagnetic drive device (15) and the second micro-electromagnetic drive device (3) are arranged on both sides of the transverse channel (1); a third micro-electromagnetic drive device (7) and a fourth micro-electromagnetic drive device (12) are arranged on the other side of the longitudinal channel (5); the third micro-electromagnetic drive device (7) and the fourth micro-electromagnetic drive device (12) are arranged on both sides of the liquid storage tank (9); The first, second, third and fourth micro-electromagnetic drive devices are partially energized to form a magnetic field, controlling the magnetorheological fluid (10) to be located at different positions in the T-shaped microchannel, thereby controlling the flow of the fluid in the T-shaped microchannel.

2. The fluid control structure of the T-shaped microchannel according to claim 1, characterized in that: The first micro-electromagnetic drive device (15) is symmetrically arranged with the second micro-electromagnetic drive device (3), the first micro-electromagnetic drive device (15) is symmetrically arranged with the fourth micro-electromagnetic drive device (12), the second micro-electromagnetic drive device (3) is symmetrically arranged with the third micro-electromagnetic drive device (7), and the third micro-electromagnetic drive device (7) is symmetrically arranged with the fourth micro-electromagnetic drive device (12); the first micro-electromagnetic drive device (15), the second micro-electromagnetic drive device (3), the third micro-electromagnetic drive device (7) and the fourth micro-electromagnetic drive device (12) are all close to the longitudinal channel (5), and all include a magnetic core shaft and a wire wound around the magnetic core shaft, and the axes of the four magnetic core shafts are all parallel to the transverse channel (1).

3. The fluid control structure of the T-shaped microchannel according to claim 2, characterized in that: A first micro-electromagnetic drive device placement groove (20) and a second micro-electromagnetic drive device placement groove (21) are provided on one side of the longitudinal channel (5), and the first micro-electromagnetic drive device placement groove (20) and the second micro-electromagnetic drive device placement groove (21) are arranged on both sides of the transverse channel (1); a third micro-electromagnetic drive device placement groove (22) and a fourth micro-electromagnetic drive device placement groove (23) are provided on the other side of the longitudinal channel (5), and the third micro-electromagnetic drive device placement groove (22) and the fourth micro-electromagnetic drive device placement groove (23) are arranged on both sides of the liquid storage tank (9); The first micro-electromagnetic drive device (15) is arranged in a first micro-electromagnetic drive device placement groove (20), the second micro-electromagnetic drive device (3) is arranged in a second micro-electromagnetic drive device placement groove (21), the third micro-electromagnetic drive device (7) is arranged in a third micro-electromagnetic drive device placement groove (22), and the fourth micro-electromagnetic drive device (12) is arranged in a fourth micro-electromagnetic drive device placement groove (23).

4. The fluid control structure of the T-shaped microchannel according to claim 3, characterized in that: It also includes a circuit control module (19), wherein the circuit control module (19) includes a main power switch, a first drive switch, a second drive switch, a third drive switch, a fourth drive switch, a fifth drive switch, and a sixth drive switch; The first micro-electromagnetic drive device (15) is provided with a first micro-electromagnetic drive device positive terminal (16) and a first micro-electromagnetic drive device negative terminal (14) at two ends, the second micro-electromagnetic drive device (3) is provided with a second micro-electromagnetic drive device positive terminal (2) and a second micro-electromagnetic drive device negative terminal (4) at two ends, the third micro-electromagnetic drive device (7) is provided with a third micro-electromagnetic drive device positive terminal (6) and a third micro-electromagnetic drive device negative terminal (8) at two ends, and the fourth micro-electromagnetic drive device (12) is provided with a fourth micro-electromagnetic drive device positive terminal (13) and a fourth micro-electromagnetic drive device negative terminal (11) at two ends; The positive electrode of the first drive switch control power supply is connected to the positive terminal (16) of the first micro-electromagnetic drive device, and the negative electrode is connected to the negative terminal (14) of the first micro-electromagnetic drive device; the negative electrode of the second drive switch control power supply is connected to the positive terminal (16) of the first micro-electromagnetic drive device, and the positive electrode is connected to the negative terminal (14) of the first micro-electromagnetic drive device; the positive electrode of the sixth drive switch control power supply is connected to the positive terminal (2) of the second micro-electromagnetic drive device, and the negative electrode is connected to the negative terminal (4) of the second micro-electromagnetic drive device; the positive electrode of the fifth drive switch control power supply is connected to the positive terminal (6) of the third micro-electromagnetic drive device, and the negative electrode is connected to the negative terminal (8) of the third micro-electromagnetic drive device; the positive electrode of the third drive switch control power supply is connected to the positive terminal (13) of the fourth micro-electromagnetic drive device, and the negative electrode is connected to the negative terminal (11) of the fourth micro-electromagnetic drive device; the negative electrode of the fourth drive switch control power supply is connected to the positive terminal (13) of the fourth micro-electromagnetic drive device, and the positive electrode is connected to the negative terminal (11) of the fourth micro-electromagnetic drive device.

5. The fluid control structure of the T-shaped microchannel according to claim 4, characterized in that: The width of the transverse channel (1) is equal to the width of the longitudinal channel (5), the width of the liquid storage tank (9) is 1.5 times the width of the transverse channel (1), and the length of the liquid storage tank (9) is equal to the width of the transverse channel (1).

6. The fluid control structure of the T-shaped microchannel according to claim 5, characterized in that: The inner surfaces of the T-shaped microchannel and the liquid storage tank (9) are coated with an oleophilic and hydrophilic coating (24), and the oleophilic and hydrophilic coating (24) is provided with a nano-silica solution modified with a rich hydrophilic group.

7. The fluid control structure of the T-shaped microchannel according to claim 6, characterized in that: The inner surface coating of the transverse channel (1) is arranged near one end of the longitudinal channel (5), and its length is 1.5 times the width of the transverse channel (1); the inner surface coating of the longitudinal channel (5) is arranged at the center, and its length is 2 times the width of the transverse channel (1).

8. The fluid control structure of the T-shaped microchannel according to claim 7, characterized in that: The magnetorheological fluid (10) is configured as a water-based or oil-based magnetorheological fluid (10), and the shape of the fluid is controlled by a magnetic field.

9. The fluid control structure of the T-shaped microchannel according to claim 8, characterized in that: The cross-sections of the transverse channel (1), the longitudinal channel (5) and the liquid storage tank (9) are all rectangular structures, and a cover plate (17) is arranged above the transverse channel (1), the longitudinal channel (5) and the liquid storage tank (9).

10. A method for controlling fluid in a T-shaped microchannel according to any one of claims 3 to 9, characterized in that: The circuit control module (19) turns on the third micro-electromagnetic drive device (7) and the fourth micro-electromagnetic drive device (12), and turns off the first micro-electromagnetic drive device (15) and the fourth micro-electromagnetic drive device (3), that is, closes the main power switch, the fourth drive switch and the fifth drive switch, so that the magnetorheological fluid (10) is attracted by the magnetic lines of force and accumulates in the liquid storage tank (9), and the fluid flows in the transverse channel (1) and the longitudinal channel (5); The circuit control module (19) turns on the first micro-electromagnetic drive device (15) and the second micro-electromagnetic drive device (3), and turns off the third micro-electromagnetic drive device (7) and the fourth micro-electromagnetic drive device (12), that is, closes the main power switch, the second drive switch and the sixth drive switch, so that the magnetorheological fluid (10) is attracted by the magnetic lines of force and accumulates in the micro-channel between the first micro-electromagnetic drive device (15) and the second micro-electromagnetic drive device (3), and the fluid flows in the longitudinal channel (5); The circuit control module (19) turns on the second micro-electromagnetic drive device (3) and the third micro-electromagnetic drive device (7), and turns off the first micro-electromagnetic drive device (15) and the fourth micro-electromagnetic drive device (12), that is, closes the main power switch, the fifth drive switch and the sixth drive switch, so that the magnetorheological fluid (10) is attracted by the magnetic lines of force and accumulates in the micro-channel between the second micro-electromagnetic drive device (3) and the third micro-electromagnetic drive device (7), and the fluid flows in the transverse channel (1) and the longitudinal channel (5); The circuit control module (19) turns on the first micro-electromagnetic drive device (15) and the fourth micro-electromagnetic drive device (12), and turns off the second micro-electromagnetic drive device (3) and the third micro-electromagnetic drive device (7), that is, closes the main power switch, the first drive switch and the third drive switch, so that the magnetorheological fluid (10) is attracted by the magnetic lines of force and accumulates in the micro-channel between the first micro-electromagnetic drive device (15) and the fourth micro-electromagnetic drive device (12), and the fluid flows in the transverse channel (1) and the longitudinal channel (5).

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