阅读说明：本技术 一种基于液晶绕流空化的微混合器及其单、多级混合系统 (Micro mixer based on liquid crystal streaming cavitation and single-stage and multi-stage mixing system thereof ) 是由 于佳佳 黄利 李杭蔚 李友荣 李谷元 于 2021-09-23 设计创作，主要内容包括：本发明涉及一种基于液晶绕流空化的微混合器及其单、多级混合系统,属于微流控技术领域。微型混合器包括样品试剂入口、混合主通道、钝体、基底和液晶；所述样品试剂入口、混合主通道和钝体设置于基底上方；液晶为微通道内化学反应或生物检测所需化学试剂、微生物等样品的载体,携带不同化学试剂、微生物等样品的液晶从不同样品试剂入口流入,进入并沿混合主通道方向流动,流经钝体发生绕流空化,利用空化非定常流动特性实现样品的充分混合。本发明利用液晶在Stokes流动区域发生绕流空化来增强液晶所携带样品之间的掺混,从而达到低Reynolds数下样品充分混合的效果,实现在简单的微小槽道内依靠最基本的实验设备高效地完成化学反应或生物检测。(The invention relates to a micro mixer based on liquid crystal streaming cavitation and a single-stage and multi-stage mixing system thereof, belonging to the technical field of micro flow control. The micro mixer comprises a sample reagent inlet, a mixing main channel, a blunt body, a substrate and liquid crystals; the sample reagent inlet, the mixing main channel and the blunt body are arranged above the substrate; the liquid crystal is a carrier of samples such as chemical reagents, microorganisms and the like required by chemical reaction or biological detection in the micro-channel, the liquid crystal carrying the samples such as different chemical reagents, microorganisms and the like flows in from the inlets of the different reagents and flows along the direction of the mixing main channel, flows through the blunt body to generate streaming cavitation, and the samples are fully mixed by utilizing the cavitation unsteady flow characteristic. The invention utilizes the streaming cavitation of the liquid crystal in the Stokes flow area to enhance the mixing of samples carried by the liquid crystal, thereby achieving the effect of fully mixing the samples under the low Reynolds number and realizing the high-efficiency completion of chemical reaction or biological detection in a simple micro channel by means of the most basic experimental equipment.)

1. A micro mixer based on liquid crystal streaming cavitation is characterized in that: the micro mixer comprises a sample reagent inlet, a mixing main channel, a blunt body, a substrate and liquid crystal;

the sample reagent inlet, the mixing main channel and the flow-around bluff body are arranged above the substrate;

the sample reagent inlet is provided with more than 2 parallel inlets, and the tail ends of the parallel inlets are connected with the main mixing channel;

the blunt body is arranged in the mixing main channel;

the liquid crystal is a carrier of chemical reagents and microorganism samples required by chemical reaction or biological detection, the liquid crystal carrying different samples flows into the mixing main channel from different sample reagent inlets, flows along the direction of the mixing main channel, flows through the blunt body to generate streaming cavitation, and the chemical reaction or biological detection is realized after mixing.

2. The micro mixer based on the streaming cavitation of the liquid crystal according to claim 1, characterized in that: the sample reagent inlet, the mixing main channel and the bluff body are all made of polydimethylsiloxane PDMS materials.

3. The micro mixer based on the streaming cavitation of the liquid crystal according to claim 1, characterized in that: the substrate is made of a glass material.

4. The micro mixer based on the streaming cavitation of the liquid crystal according to claim 1, characterized in that: the blunt body is a cylinder arranged in the main channel.

5. The micro mixer based on the streaming cavitation of the liquid crystal according to claim 4, characterized in that: the blunt bodies are arrays of the same geometric cylinder.

6. The micro mixer based on the streaming cavitation of the liquid crystal according to claim 4, characterized in that: the blunt body is an array of different geometric cylinders.

7. The micro mixer based on the streaming cavitation of the liquid crystal according to claim 1, characterized in that: the liquid crystal adopts organic small molecule liquid crystal as a carrier for a hydrophobic chemical reagent or a microorganism sample; the liquid crystal adopts water-soluble liquid crystal as a carrier for hydrophilic chemical reagents or samples of microorganisms.

8. The micro mixer based on the streaming cavitation of the liquid crystal according to claim 1, characterized in that: the microchannel comprises a plurality of sub-channels which are superposed up and down or left and right in parallel to form a multichannel micro mixer.

9. A single-stage mixing system based on a micromixer according to any one of claims 1 to 8, characterized in that: the single-stage mixing system also includes a single-stage micromixer.

10. The multistage mixing system based on the micromixer according to any one of claims 1 to 8, characterized in that: the multistage mixing system also comprises a plurality of micro mixers which are connected in series, in parallel or in series and parallel.

Technical Field

The invention belongs to the technical field of microfluidics, and relates to a micro mixer based on liquid crystal streaming cavitation and a single-stage and multi-stage mixing system thereof.

Background

The micro-fluidic chip integrates traditional laboratories of biology, chemistry and the like on a small chip by adopting a micro-electro-mechanical system technology to realize multiple functions of sample introduction, dilution, mixing, reaction, detection and the like, and is also called a lab-on-a-chip. The micro-fluidic chip has the advantages of miniaturization, integration, portability and the like, the social demand for the on-site real-time detection of the micro-fluidic chip is increased in a blowout mode in recent years, and particularly the critical moment for dealing with the epidemic situation of the new coronary pneumonia is achieved. Competition in the field of microfluidic chips is primarily based on fluid manipulation mechanisms and methods. Micro-scale flow is typically characterized by a small number of reynolds (re) flows, flows in laminar flow regions, and laminar non-mixing flows lead to difficulties in mixing of samples (chemicals, microorganisms, etc.) within the microfluidic chip, thereby affecting chemical or biological reactions within the microfluidic chip. Therefore, micromixing is one of the cores of fluid manipulation at the microscale, and is an important index for measuring the technology of microfluidic chips.

The blunt body arranged in the micro-channel is a passive mixing mode based on chaos effect, the flow line mode is changed by utilizing the streaming generated by the blunt body, the mixing among all the flow layers is enhanced, and a better mixing effect is obtained. Compared with passive mixing in forms of layered composite type, injection type and the like, passive mixing with a built-in bluff body has the advantages of simple structure, low difficulty in processing and integration, easiness in operation and the like, but the application conditions are extremely harsh (the requirement on Re is more than 150). Compared with active mixing in the forms of magnetic stirring, electric field promotion and the like, passive mixing with a built-in blunt body has the advantages of simple required equipment, low cost, no external field interference and the like, but the mixing efficiency is relatively low. Therefore, the passive mixing of the built-in bluff body has obvious advantages, but the two problems of harsh application conditions and relatively low mixing efficiency are not ignored.

The invention takes liquid crystal as a carrier of samples such as chemical reagents, microorganisms and the like required by chemical reaction or biological detection in a micro-channel, the liquid crystal carrying the samples such as different chemical reagents, microorganisms and the like flows in from different reagent inlets, enters and flows along the direction of a main mixing channel, flows through a bluff body to generate streaming cavitation, and utilizes the streaming cavitation and the flow characteristics of the liquid crystal in the micro-channel under an extremely low Re number (Re <1) to realize the efficient mixing of the samples such as the chemical reagents, the microorganisms and the like, thereby providing a new way for the efficient mixing of the fluid under the micro-scale, finally realizing the efficient completion of complex chemical reaction or biological detection in the simple micro-channel by means of most basic experimental equipment, and remarkably reducing the workload of analysis and detection and related cost.

Disclosure of Invention

In view of the above, the present invention provides a micro mixer based on liquid crystal streaming cavitation and a single-stage and multi-stage mixing system thereof, and aims to solve the problems of complex structure, high cost, low laminar flow mixing efficiency, complex operation, and high processing and integration difficulty existing in the existing mixing technology.

In order to achieve the purpose, the invention provides the following technical scheme:

a micro mixer based on liquid crystal streaming cavitation comprises a sample reagent inlet, a mixing main channel, a blunt body, a substrate and liquid crystal;

the sample reagent inlet, the mixing main channel and the flow-around bluff body are arranged above the substrate;

the sample reagent inlet is provided with more than 2 parallel inlets, and the tail ends of the parallel inlets are connected with the main mixing channel;

the blunt body is arranged in the mixing main channel;

the liquid crystal is a carrier of chemical reagents and microorganism samples required by chemical reaction or biological detection, the liquid crystal carrying different samples flows into the mixing main channel from different sample reagent inlets, flows along the direction of the mixing main channel, flows through the blunt body to generate streaming cavitation, and the chemical reaction or biological detection is realized after mixing.

Optionally, the sample reagent inlet, the mixing main channel and the bluff body are all made of polydimethylsiloxane PDMS material.

Optionally, the substrate is made of a glass material.

Optionally, the blunt body is a cylinder disposed in the main channel.

Optionally, the blunt bodies are an array of identical geometric cylinders.

Optionally, the blunt body is an array of different geometric cylinders.

Optionally, the liquid crystal adopts organic small molecule liquid crystal as a carrier for a hydrophobic chemical reagent or a microorganism sample; the liquid crystal adopts water-soluble liquid crystal as a carrier for hydrophilic chemical reagents or samples of microorganisms.

Optionally, the microchannel includes a plurality of sub-channels stacked up and down or stacked left and right in parallel to form a multichannel micromixer.

Based on the single-stage mixing system of the micromixer, the single-stage mixing system further comprises a single-stage micromixer.

Based on the multistage mixing system of the micromixer, the multistage mixing system also comprises a plurality of micromixers which are connected in series, in parallel or in series and parallel.

The invention has the beneficial effects that:

1. the micro mixer and the single-stage and multi-stage mixing systems thereof have simple structures and low processing difficulty, and can realize high-efficiency mixing only by liquid crystal materials, the blunt bodies and the micro channels.

2. The micro mixer and the single-stage and multi-stage mixing systems thereof have lower manufacturing cost, the cost is mainly concentrated on liquid crystal materials, various liquid crystals are easily purchased in the market, and the price is lower.

3. The micro mixer and the single-stage and multi-stage mixing systems thereof have good mixing effect, the mixing effect under the extremely low Re number is far better than that of the existing layered composite type, injection type and other built-in passive mixers with bluff bodies, and the typical characteristic of small flowing Re number of micro-scale fluid is met.

4. The micro mixer and the single-stage and multi-stage mixing systems thereof have simple use conditions, can realize high-efficiency mixing under extremely low Re number, do not need a magnetic field and an electric field generator in active mixing, do not need to meet the strict Re number requirement (Re is more than 150) in passive mixing, and are suitable for micro-fluidic chips.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.

Drawings

For the purposes of promoting a better understanding of the objects, aspects and advantages of the invention, reference will now be made to the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic structural diagram of a micro-mixer based on liquid crystal streaming cavitation in an embodiment;

FIG. 2 is a diagram of the evolution of nematic phase 5CB liquid crystal Stokes streaming cavitation in a micro channel along with time;

FIG. 3 is a nematic 5CB liquid crystal Stokes streaming cavitation vortex cell perturbation map in a micro channel;

FIG. 4 is a schematic diagram of a single stage mixer with bluff bodies of different geometries;

FIG. 5 is a schematic diagram of a same geometry bluff body array single stage mixer;

FIG. 6 is a schematic diagram of a single stage mixer with a bluff body array of different geometries;

FIG. 7 is a schematic parallel cross-sectional view of a single-stage multi-channel micromixer;

fig. 8 is a schematic cross-sectional view of a multi-stage multi-channel serial micromixer.

Reference numerals: 1-a bypass blunt body, 2-a substrate, 3-a mixing main channel, a-a sample reagent inlet I, a B-a sample reagent inlet II and a C-a sample reagent outlet III.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention in a schematic way, and the features in the following embodiments and examples may be combined with each other without conflict.

Wherein the showings are for the purpose of illustrating the invention only and not for the purpose of limiting the same, and in which there is shown by way of illustration only and not in the drawings in which there is no intention to limit the invention thereto; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc., based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of description, but it is not an indication or suggestion that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes, and are not to be construed as limiting the present invention, and the specific meaning of the terms may be understood by those skilled in the art according to specific situations.

Example one

The microfluid single-stage efficient mixer based on liquid crystal streaming cavitation implementation as shown in fig. 1 comprises a first sample reagent inlet A, a second sample reagent inlet B, a mixing main channel 3, a substrate 2 arranged below the mixing main channel 3, a liquid crystal carrier arranged in the mixing main channel 3 and capable of flowing along the channel direction, a streaming blunt body 1 arranged in the mixing main channel 3, and a sample reagent outlet III C.

When in use, the liquid crystal carrier carrying samples such as chemical reagents, microorganisms and the like is arranged in the micropumpThe first sample and the second sample enter the mixing main channel 3 through the first sample reagent inlet A and the second sample reagent inlet B respectively. The micropump can adjust the speed of the mixed process fluid, the speed directly influencing the cavitation effect. When the liquid crystal carrier is nematic phase 5CB, the critical Re number of the streaming cavitation of the nematic phase 5CB liquid crystal in the micro-channel is (2.6 +/-0.3) multiplied by 10^-3Far less than the Re number requirement of the conventional passive mixing, i.e. Re>150 as shown in fig. 2. When the streaming cavitation of the nematic phase 5CB liquid crystal in the tiny channel occurs, the rear of the blunt body will generate random vortex cell disturbance, and the mixing effect is enhanced, as shown in FIG. 3. Samples such as chemical reagents and microorganisms required by chemical reaction or biological detection in the micro-channel are subjected to enhanced fluid mixing under the turbulence effect of nematic liquid crystal streaming cavitation, so that the samples such as the chemical reagents and the microorganisms are more fully mixed.

Example II

Different components and contents of chemical reagents, microorganisms and other samples have different requirements on the mixing effect required by detection. Therefore, the invention can meet the requirements of quicker and more accurate detection by changing the blunt body. Under general conditions, the detection difficulty is low, the amount of samples such as detected chemical reagents, microorganisms and the like is enough, and the accurate detection can be realized by the mixing effect of a single cylinder. As shown in FIG. 4, as the detection difficulty increases, the precision requirement increases, the shape and size of the cylinder can be changed to enhance the blending effect, and the detection purpose is achieved. In actual detection, when the blending effect of cylinder is not enough to satisfy the detection needs, can promote the blending effect with the triangular prism blunt body. But the triangular prism blunt mixing microchannel can be more difficult and costly to manufacture. When the single-column blunt body blending effect cannot meet the detection requirements of samples such as higher-precision chemical reagents, microorganisms and the like, the blunt body of the present invention may be configured as a plurality of blunt body arrays of the same geometric structure, as shown in fig. 5. To further improve the blending effect, the same geometry blunt body array may also be configured as a different geometry blunt body array, as shown in fig. 6.

EXAMPLE III

As the micro mixer provided by the invention does not need an external electric field or magnetic field, the micro mixer has the advantages of simple and small structure, easiness in integration, convenience in carrying and the like, and has a wide application range. In the nucleic acid detection in the new crown epidemic situation, a large number of examinees and a large detection amount need to be subjected to primary mixing for multiple times and large amount, and the same condition can also occur in the detection of food safety. For the mixing requirements of repetition and large amount, the single-stage mixer can be integrated in parallel, and the mixing detection is carried out in a multi-line mode, so that the detection efficiency can be greatly improved, and the detection cost and time are saved, as shown in fig. 7. In some detection of samples such as chemical reagents and microorganisms, sometimes, if a mixed secondary product is to be detected, multiple samples such as chemical reagents and microorganisms need to be mixed in multiple stages, as shown in fig. 8, generally, the detection difficulty of the secondary product is higher than that of the primary product, so that a better blending effect is needed, and the blending effect needs to be enhanced step by step. Based on the third embodiment, the blending effect can be improved step by step.

Example four

In the detection of samples such as chemical reagents, microorganisms and the like, hydrophobic samples to be detected, such as lipid, adopt organic small molecule liquid crystal such as 5CB, MBBA and the like as a carrier; hydrophilic test samples, such as urine, should use water-soluble liquid crystal such as SSY, DSCG, etc. as carrier, as shown in Table 1.

TABLE 1 common Carrier liquid Crystal

Finally, the above embodiments are only intended to illustrate the technical solutions of the present invention and not to limit the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all of them should be covered by the claims of the present invention.