Multi-phase composite micro mixer combined with negative poisson ratio micro valve

Abstract

The utility model discloses a multiphase composite micro-mixer combined with a negative Poisson's ratio micro-valve. The multiphase composite micro-mixer comprises a glass substrate, a micro-mixer micro-fluidic chip and a glass cover plate, the micro-fluidic chip of the micro-mixer is provided with a liquid inflow channel, a liquid mixing channel and a negative poisson ratio nickel-titanium alloy micro-valve; outlets of the multiple liquid inflow flow channels intersect and communicate with an inlet of the liquid mixing flow channel, the multiple liquid inflow flow channels are internally provided with negative Poisson's ratio nickel-titanium alloy micro valves, the exteriors of the multiple liquid inflow flow channels abut against heat conduction pieces, and the multiple heat conduction pieces are arranged on the glass substrate; the multi-phase composite micro-mixer is used for transferring heat to the negative Poisson's ratio nickel-titanium alloy micro-valve through the heat-conducting fin so as to regulate and control the opening and closing states of the negative Poisson's ratio nickel-titanium alloy micro-valve; the scheme is high in reliability, high in mixing efficiency, high in speed and capable of performing multiphase and quantitative mixing, so that the micromixer plays a greater effect in scientific research and social life.

Description

Technical Field

[0001] The utility model relates to the technical field of micro mixers, in particular to a multiphase composite micro mixer combined with a negative Poisson's ratio micro valve. Background Art

[0002] Microfluidics integrates basic operational units such as sample preparation, reaction, separation, and detection in chemical, biological, and medical analysis processes onto a micron-scale chip, automating complex analytical functions. Micromixers, a key component of this technology, are widely used. With the in-depth development and application of fluid micromixing technology in chemical engineering, medicine, and materials physics, these fields are placing higher demands on its three key performance indicators: efficient mixing, precise controllability, and portable integration.

[0003] Micromixers can be divided into passive micromixers and active micromixers according to the input energy. Current micromixers have the following disadvantages:

[0004] 1. Simply rely on two or more valve diaphragms to periodically and alternately disturb the fluid to achieve mixing.

[0005] 2. Most micro mixers are suitable for lower flow rate liquid control. When the flow rate is higher, the back pressure of the fluid channel is higher and cannot generate enough pressure for disturbance.

[0006] 3. Some mixers have complex structures and are difficult to process, which limits their wide application.

[0007] Therefore, a micro mixer with high reliability, high mixing efficiency, fast speed and the ability to perform multiphase and quantitative mixing is needed to play a greater role in scientific research and social life. Utility Model Content

[0008] The purpose of the utility model is to provide a multiphase composite micromixer combined with a negative Poisson's ratio microvalve, which has high reliability, high mixing efficiency, high speed and can perform multiphase and quantitative mixing.

[0009] In order to solve the above technical problems, the utility model provides a multiphase composite micromixer combined with a negative Poisson's ratio microvalve, comprising a glass substrate, a micromixer microfluidic chip arranged on the glass substrate, and a glass cover plate covering the micromixer microfluidic chip; the micromixer microfluidic chip is provided with a liquid inlet channel, a liquid mixing channel and a negative Poisson's ratio nickel-titanium alloy microvalve; the outlets of multiple liquid inlet channels intersect and are connected to the inlet of the liquid mixing channel, the multiple liquid inlet channels are provided with the negative Poisson's ratio nickel-titanium alloy microvalves, the outsides of the multiple liquid inlet channels are abutted with heat conducting plates, and multiple heat conducting plates are provided on the glass substrate; the multiphase composite micromixer is used to transfer heat to the negative Poisson's ratio nickel-titanium alloy microvalve through the heat conducting plates, and thereby regulate the opening and closing state of the negative Poisson's ratio nickel-titanium alloy microvalve.

[0010] In one embodiment, the liquid mixing channel includes a first branch channel and a chaotic mixing channel, the inlets of multiple first branch channels are connected to the intersection of the outlets of multiple liquid inflow channels, and the outlets of multiple first branch channels intersect and are connected to the inlet of the chaotic mixing channel.

[0011] In one embodiment, the two first branch channels are arranged in a ring shape around the chaotic mixing channel.

[0012] In one embodiment, the liquid mixing channel also includes a second branch flow channel, and the inlets of multiple second branch flow channels are connected to the intersection of the outlets of multiple first branch flow channels, and the outlets of multiple second branch flow channels intersect and are connected to the inlet of the chaotic mixing channel.

[0013] In one embodiment, the two second branch flow paths surround the chaotic mixing path in a ring shape, and the two first branch flow paths surround the two second branch flow paths.

[0014] In one embodiment, a plurality of separately arranged fluid obstruction dams are provided between the inlet and the outlet of the chaotic mixing passage.

[0015] In one embodiment, the plurality of fluid obstruction dams are arranged obliquely relative to the conveying direction of the chaotic mixing passage, and the plurality of fluid obstruction dams are arranged parallel to each other.

[0016] In one embodiment, the negative Poisson's ratio nickel-titanium alloy microvalve is U-shaped, the U-shaped opening of the negative Poisson's ratio nickel-titanium alloy microvalve faces the inlet of the liquid inflow channel, and the unheated negative Poisson's ratio nickel-titanium alloy microvalve abuts against the peripheral wall of the liquid inflow channel.

[0017] In one embodiment, the negative Poisson's ratio nickel-titanium alloy microvalve includes a first phase transition temperature region of 5° to 15°, a second phase transition temperature region of 20° to 40°, and a third phase transition temperature region of 45° to 90°.

[0018] The beneficial effects of the utility model are as follows:

[0019] 1. This multiphase composite micromixer can achieve rapid mixing of multiple solutions and different phases with high mixing efficiency and fast mixing speed;

[0020] 2. The negative Poisson's ratio nickel-titanium alloy microvalve has a fast response speed and can well complete the concentration mixing of the predetermined mass or volume of the solution;

[0021] 3. The multiphase composite micro-mixer cleverly utilizes the dislocation principle to expand the applicable range of fluid flow. It has a sophisticated and simple structure, is easy to manufacture and install, and has modular characteristics, making it easy to integrate and apply. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 It is a structural diagram provided by an embodiment of the present utility model;

[0024] Figure 2 yes Figure 1 Schematic diagram of the disassembled structure;

[0025] Figure 3 yes Figure 2 Schematic diagram of the enlarged structure of part A.

[0026] The reference numerals are as follows:

[0027] 10. Glass substrate; 11. Thermal conductive sheet;

[0028] 20. Micro-mixer microfluidic chip; 21. Liquid inflow channel; 22. Liquid mixing channel; 221. First branch channel; 222. Second branch channel; 223. Chaotic mixing channel; 224. Fluid obstruction dam; 23. Negative Poisson's ratio nickel-titanium alloy microvalve;

[0029] 30. Glass cover; 31. Input hole; 32. Output hole. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0031] The utility model provides a multiphase composite micro-mixer combined with a negative Poisson's ratio micro-valve, which is implemented as follows: Figures 1 to 3 As shown, it includes a glass substrate 10, a micro-mixer microfluidic chip 20 provided on the glass substrate 10, and a glass cover 30 covering the micro-mixer microfluidic chip 20, wherein the micro-mixer microfluidic chip 20 can be processed by photolithography, and the glass substrate 10, the micro-mixer microfluidic chip 20, and the glass cover 30 are sealed by a thermal bonding method; the micro-mixer microfluidic chip 20 is provided with a liquid inlet channel 21, a liquid mixing channel 22 and a negative Poisson's ratio nickel-titanium alloy microvalve 23; the outlets of the multiple liquid inlet channels 21 intersect and are connected to the inlet of the liquid mixing channel 22, and the multiple liquid mixing channels 22 are connected to the inlet of the liquid mixing channel 22. Each liquid inflow channel 21 is provided with a negative Poisson's ratio nickel-titanium alloy microvalve 23, and the outside of the multiple liquid inflow channels 21 is abutted with a heat conducting plate 11, and the multiple heat conducting plates 11 are all arranged on the glass substrate 10, wherein the glass cover plate 30 is provided with corresponding input holes 31 and output holes 32, wherein the multiple input holes 31 are respectively connected to the inlets of the multiple liquid inflow channels 21, and the output holes 32 are connected to the outlet of the liquid mixing channel 22; the multiphase composite micromixer is used to transfer heat to the negative Poisson's ratio nickel-titanium alloy microvalve 23 through the heat conducting plate 11, and thereby regulate the opening and closing state of the negative Poisson's ratio nickel-titanium alloy microvalve 23.

[0032] During application, the liquids to be mixed are input through multiple liquid inlet channels 21 respectively, and converge into the liquid mixing channel 22 for mixing; during this process, by heating the heat conducting plate 11, the heat conducting plate 11 can transfer heat to the negative Poisson's ratio nickel-titanium alloy microvalve 23. Depending on the heating conditions, the opening and closing conditions of the negative Poisson's ratio nickel-titanium alloy microvalve 23 will also change accordingly.

[0033] For example, from Figure 3 As shown, in this embodiment, the negative Poisson's ratio nickel-titanium alloy microvalve 23 is arranged in a U-shape, and the U-shaped opening of the negative Poisson's ratio nickel-titanium alloy microvalve 23 faces the inlet of the liquid inflow channel 21, and the unheated negative Poisson's ratio nickel-titanium alloy microvalve 23 is in contact with the peripheral wall of the liquid inflow channel 21; specifically, the negative Poisson's ratio nickel-titanium alloy microvalve 23 at this time includes a first phase change temperature region of 5° to 15°, a second phase change temperature region of 20° to 40°, and a third phase change temperature region of 45° to 90°.

[0034] Therefore, after adopting this setting mode, in different temperature ranges, the two sides of the negative Poisson's ratio nickel-titanium alloy microvalve 23 will have different deformations. When the negative Poisson's ratio nickel-titanium alloy microvalve 23 needs to be opened, the heat conducting plate 11 is controlled to apply temperature to control the opening and closing of the negative Poisson's ratio nickel-titanium alloy microvalve 23. For example, when the temperature rises, the sheet metal on both sides of the negative Poisson's ratio nickel-titanium alloy microvalve 23 will curl inward and close. When the temperature drops, the shape of the negative Poisson's ratio nickel-titanium alloy microvalve 23 changes to its original shape, and the time for the negative Poisson's ratio nickel-titanium alloy microvalve 23 to change phase is short. The fastest speed can reach 0.01s. The control variable can be formed by calculating the flow rate of the flow channel and combining the deformation of the negative Poisson's ratio nickel-titanium alloy microvalve 23, thereby controlling the concentration and volume of the inflowing liquid, thereby achieving the effect of quantitative control and mixing. Moreover, due to its negative Poisson's ratio characteristics, it can withstand a large back pressure in the microchannel. During the loading process, it can absorb heat through martensitic phase transformation and better withstand greater stress during deformation. It is superior to other valve bodies and makes up for the shortcomings between the micromixer and the microvalve, thereby making the device have a better mixing effect.

[0035] like Figure 3 As shown, this embodiment specifically sets up three liquid inlet channels 21, and the three liquid inlet channels 21 form an angle of 60° with each other. After adopting this setting, the double 60-degree channel angle causes the solutions to collide, and convection collision is obtained under laminar flow state.

[0036] like Figure 3 As shown, this embodiment sets the liquid mixing channel 22 to include a first branch channel 221 and a chaotic mixing channel 223. The inlets of multiple first branch channels 221 are connected to the intersection of the outlets of multiple liquid inflow channels 21, and the outlets of multiple first branch channels 221 intersect and are connected to the inlet of the chaotic mixing channel 223. Specifically, this embodiment sets two first branch channels 221 to surround the chaotic mixing channel 223 in a ring shape.

[0037] With this arrangement, the two first branching channels 221 substantially form an annular branching region. When the liquids are branched and then merged, the disturbance of the fluids is increased, thereby improving the mixing performance.

[0038] like Figure 3 As shown, this embodiment sets the liquid mixing flow channel 22 to also include a second branch flow channel 222, and the inlets of the multiple second branch flow channels 222 are connected to the intersection of the outlets of the multiple first branch flow channels 221, and the outlets of the multiple second branch flow channels 222 intersect and are connected to the inlet of the chaotic mixing channel 223; specifically, this embodiment sets two second branch flow channels 222 to surround the chaotic mixing channel 223 in a ring shape, and the two second branch flow channels 222 are surrounded by two first branch flow channels 221.

[0039] With this arrangement, the two second diversion channels 222 substantially form an annular diversion area. After the liquid is diverted and merged again, the disturbance of the fluid is further increased, thereby improving the mixing performance.

[0040] like Figure 3 As shown, this embodiment provides a plurality of separately arranged fluid obstruction dams 224 between the inlet and outlet of the chaotic mixing passage 223, and the plurality of fluid obstruction dams 224 are arranged obliquely relative to the conveying direction of the chaotic mixing passage 223, and the plurality of fluid obstruction dams 224 are arranged parallel to each other.

[0041] After adopting this setting method, the applicable range of fluid flow is expanded through the design of the fluid obstruction dam 224 and the wide and narrow flow channels, which promotes greater convection in the cavity of the flow channel and further improves the effect of fluid mixing, so that the liquid can flow out through the outlet of the chaotic mixing passage 223 after being fully mixed.

[0042] The simulation verification of this embodiment is as follows:

[0043] By creating a chaotic convection effect, the fluid velocity is accelerated in intervals to allow the fluid to be mixed; COMSO6.1 is used to predict the plane streamlines of the fluid in the staggered module and to calculate the velocity and concentration of the fluid in the plane; the computational fluid dynamics software is based on finite elements, and the simulation conditions are to set the circular area and the straight structure area as two-dimensional, the fluid is water of different concentrations, and the initial concentration condition of the fluid is set as the inflow liquid concentration c1 = 1 mol / L of the first liquid inflow channel 21, the inflow liquid concentration c2 = 2 mol / L of the second liquid inflow channel 21, and the inflow liquid concentration c3 = 3 mol / L of the third liquid inflow channel 21, simulating the mixing of multiphase solutions, the inflow velocity is 10 mm / s, and the geometric dimensions of the above flow channels are all in the micron level. The numerical model adopts the continuity equation, the viscous incompressible Navier-Stokes equation and the convection-diffusion equation.

[0044] The continuity equation is:

[0045] ▽.u=0

[0046] The viscous incompressible Navier-Stokes equations are:

[0047]

[0048] The convection-diffusion equation is:

[0049]

[0050] Where u is the velocity vector of the fluid, ρ is the fluid density, v is the kinematic viscosity of the fluid, t is the time, p is the fluid pressure, c is the molar concentration of the component, and D is the diffusion coefficient of the component.

[0051] In addition to the basic fluid mechanics analysis equations mentioned above, the Reynolds number (Re) can reflect the motion state of the fluid and is used to analyze the mixing performance of the fluid. It has great reference value for the design of flow channel dimensions, the estimation of inflow velocity, and the comparison of mixing efficiency. Its mathematical definition is:

[0052]

[0053] During the simulation, the inner wall of the channel was set to a non-slip boundary condition, the outlet was not set to pressure, and the fluid temperature was 298.15K.

[0054] From the simulation results, it can be seen that the mixing effect is good and the efficiency is high. The structural device is fully feasible. The fluid speed in the flow channel can reach up to 0.2m / s. The mixing of the three liquid phases can be completed within a few hundred milliseconds of the total flow channel length. The mixing speed is fast and the efficiency is high.

[0055] The concentration is standardized. The concentration is subtracted from the average value, squared, and then divided by the average value. Finally, the square root is taken to obtain the normalized value and a concentration distribution graph is drawn after calculation. The closer the value is to 0, the better the mixing effect is. It can be seen that the mixing effect at the outlet is good.

[0056] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A multiphase composite micromixer combined with a negative Poisson's ratio microvalve, characterized in that: The invention comprises a glass substrate, a micro-mixer microfluidic chip arranged on the glass substrate, and a glass cover plate covering the micro-mixer microfluidic chip; The micro-mixer microfluidic chip is provided with a liquid inlet channel, a liquid mixing channel, and a negative Poisson's ratio nickel-titanium alloy microvalve; the outlets of the plurality of liquid inlet channels intersect and are connected to the inlet of the liquid mixing channel; the plurality of liquid inlet channels are each provided with the negative Poisson's ratio nickel-titanium alloy microvalve; the exteriors of the plurality of liquid inlet channels are each abutted with a heat conducting sheet, and the plurality of heat conducting sheets are each provided on the glass substrate; The multiphase composite micromixer is used to transfer heat to the negative Poisson's ratio nickel-titanium alloy microvalve through the heat conducting plate, thereby regulating the opening and closing state of the negative Poisson's ratio nickel-titanium alloy microvalve.

2. The multiphase composite micromixer according to claim 1, characterized in that: The liquid mixing channel includes a first branch channel and a chaotic mixing channel. The inlets of multiple first branch channels are connected to the intersection of the outlets of multiple liquid inflow channels, and the outlets of multiple first branch channels intersect and are connected to the inlet of the chaotic mixing channel.

3. The multiphase composite micromixer according to claim 2, characterized in that: The two first branch channels are surrounded by the chaotic mixing channel in a ring shape.

4. The multiphase composite micromixer according to claim 2, characterized in that: The liquid mixing channel also includes a second branch flow channel, the inlets of the plurality of second branch flow channels are connected to the intersection of the outlets of the plurality of first branch flow channels, and the outlets of the plurality of second branch flow channels intersect and are connected to the inlet of the chaotic mixing channel.

5. The multiphase composite micromixer according to claim 4, characterized in that: The two second branch flow paths surround the chaotic mixing path in a ring shape, and the two first branch flow paths are surrounded by the two second branch flow paths.

6. The multiphase composite micromixer according to claim 2, characterized in that: A plurality of fluid obstruction dams arranged separately are provided between the inlet and the outlet of the chaotic mixing passage.

7. The multiphase composite micromixer according to claim 6, characterized in that: The plurality of fluid obstruction dams are arranged obliquely relative to the conveying direction of the chaotic mixing passage, and the plurality of fluid obstruction dams are arranged parallel to each other.

8. The multiphase composite micromixer according to claim 1, characterized in that: The negative Poisson's ratio nickel-titanium alloy microvalve is U-shaped, and the U-shaped opening of the negative Poisson's ratio nickel-titanium alloy microvalve faces the inlet of the liquid inflow channel, and the unheated negative Poisson's ratio nickel-titanium alloy microvalve abuts against the peripheral wall of the liquid inflow channel.

9. The multiphase composite micromixer according to claim 8, characterized in that: The negative Poisson's ratio nickel-titanium alloy microvalve includes a first phase transition temperature region of 5° to 15°, a second phase transition temperature region of 20° to 40°, and a third phase transition temperature region of 45° to 90°.

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