KR20030025075A - Micro mixer for chaotic mixing of fluids - Google Patents

Abstract

PURPOSE: A micro mixer is provided to reduce loss of pressure, while permitting the chaotic mixing of fluids to be performed in a micro channel structure by driving fluids through the use of pressure or electric field. CONSTITUTION: A micro mixer comprises a micro channel structure; a clock-wise twisted blade element(110) and a counterclock-wise twisted blade element(120) disposed in the micro channel structure, and which performs a chaotic mixing on the fluid; grooves formed at the horizontal wall and vertical wall, and a groove formed at the bottom surface of the micro channel structure so as to allow for assembly of twisted blade elements; and two taps formed on twisted blade elements for an assembly to grooves. The micro mixer is produced by MEMS, LIGA or micro-stereolithography process.

Description

Micro mixer for chaotic mixing of fluids

The present invention is based on the principle of the Kenics Static Mixer to micronize the Kenics Static Mixer, i.e., to a micromixer for chaos mixing of fluids in which pressure loss does not occur significantly compared to microchannels having the same pipe diameter. It is about.

On the other hand, the present invention includes a twisted blade element twisted at a predetermined angle of a simple shape and a micro channel structure in which the twisted blade member is arranged to drive a fluid by pressure or an electric field or the like to mix chaos in the micro channel structure. This relates to a micromixer for chaotic mixing of fluids which makes this feasible.

With the miniaturization of analytical technology, research and development of micro devices that can process and analyze a large number of samples and reagents in small units are being carried out, and technologies such as biochips and lab-on-a-chip are in progress. This belongs to this category. Microdevices, such as biochips or lab-on-a-chips, contain multiple channels or microstructures that allow all the processes required for analysis to be performed on one small chip. In such a compact device, effective mixing of reagents and the sample carried by microchannels for analytical or (bio) chemical reactions is essential.

In existing large-scale systems, large Reynolds numbers can be used to drive propellers in fluids or to introduce moving parts, such as magnetic beads, into the fluid to induce turbulent flow through them. A mixture of fluids was obtained.

However, in the case of a very small system, the Reynolds number is greatly reduced so that turbulence is formed in addition to the laminar flow, so that only mixing by diffusion can be expected, and as a result, it is difficult to obtain a uniform mixture of fluids. In order to achieve the mixing performance of large-scale systems, moving parts are introduced inside the microchannel, which leads to the improvement of the mixing performance through the active mixing method. Difficult to manufacture results in expensive manufacturing costs and significant difficulties in use, cleaning and integration with other micro devices. Alternatively, there is a passive mixing method that introduces several static microstructures inside the microchannel to induce fluid mixing. In this case, the mixing performance may be lower than that of the active mixing method, but the problem of the active mixing method may be solved. In particular, the manufacturing cost may be greatly reduced and the integration with other micro devices may be easy.

Micro mixers using various manual mixing methods have been reported in response to the above requirements, but the conventional manual mixing methods have a disadvantage of causing a large pressure loss by installing many obstacles inside the micro channel. In addition, the increasingly complex obstacles to make the manufacturing process difficult has the disadvantage of increasing the manufacturing cost.

Figure 1 shows the configuration of the most representative Kenics Static Mixer (motionless mixer) in the conventional polymer processing technology (motionless mixer). This mixer 1 has a structure in which short helical elements 11 in clockwise and counterclockwise directions are alternately fixed in the circular pipe 10. These helical members 11 are fixed to the inner wall of the circular pipe 10 and are characterized in that each member 11 is alternately positioned at right angles as shown.

The fluid of the mixer 1 is characterized by being driven by the pressure difference at the end of the pipe 10, and the spiral elements 11 located in the pipe 10 are connected to the pipe 10 by the pressure difference. If the flow in the axial direction of the pipe 10 in addition to the axial direction to form a flow in the transverse direction of the axis. As a result, the two fluids 12, 13 entering the mixer are not only continuously divided in half by the helical elements 11, but also in the radial direction by the transverse flow resulting in chaotic mixing. This results in a very effective mixture of the two fluids.

However, the kinetic static mixer 1 which induces effective fluid mixing as described above cannot be used other than the driving of the fluid by the pressure difference, and cannot be applied at the micro level, and furthermore, the manufacturing method at the micro level. It also has an impossible problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a micromixer for chaotic mixing of fluids in which the kneas static mixer is micronized, that is, pressure loss does not occur significantly compared to microchannels having the same pipe diameter. Its purpose is to.

Another object of the present invention is to include a twisted blade element twisted at an angle of a simple shape and a microchannel structure in which the twisted blade member is arranged to drive a fluid in a microchannel structure by driving a fluid by pressure or electric field or the like. There is provided a micromixer for chaotic mixing of fluids that allows mixing to be realized.

1 is a block diagram of a Kenics Static Mixer according to the prior art.

2 is a block diagram of a microchannel structure of the micromixer according to the present invention;

3a is a schematic view of a clockwise twisted blade element according to the present invention;

Figure 3b is a block diagram of a counterclockwise twisted blade member according to the present invention.

4a and 4b is an overall assembly configuration of the micromixer according to the present invention.

<Description of the symbols for the main parts of the drawings>

100 microchannel structure 101 groove

110: clockwise twist blade member 111, 121: tab

112: clockwise spiral part

120: counterclockwise twisted blade member 122: counterclockwise spiral

130: upper micro channel structure

140: lower microchannel structure

In order to achieve the above object, a micromixer for chaotic mixing of a fluid according to the present invention,

And a twisted blade member disposed in the microchannel structure and at least one twisted member spirally twisted at an angle to chaoticly mix the inflowing fluid, wherein the twisted blade member is assembled to the microchannel structure. Grooves on the horizontal and vertical walls are formed, the twisted blade member having at least two tabs for assembling the grooves, the micromixer structure being MEMS, LIGA or micro-stereolithography. It is characterized by the fact that it is manufactured through micromachining techniques such as

In a preferred embodiment of the present invention, the helical twist angle of the twist blade member is arbitrary, and the groove of the micro channel structure can be formed to match this arbitrary twist angle.

In a preferred embodiment of the present invention, the cross-sectional shape of the micro channel structure is determined by the micro machining technique.

In a preferred embodiment of the invention, the twisted blade members are arranged in plural in the micro channel structure in a combination of a clock member twisted clockwise and a blade member twisted counterclockwise.

In a preferred embodiment of the present invention, the choice of the material of the microchannel structure allows the flow drive of the fluids therein to be via a pressure or electric field.

In a preferred embodiment of the present invention, the micro channel structure and the twisted blade member can be manufactured by a predetermined lamination method.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the micromixer for chaotic mixing of the fluid according to the present invention. In the following description of the present invention, when it is determined that detailed descriptions of related well-known technologies or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of a user or an operator. Therefore, the definition should be made based on the contents throughout the specification.

2 shows a micro channel structure 100 of a micro mixer for chaotic mixing of fluids according to the present invention. Referring to FIG. 2, the micro channel structure 100 is a groove formed on its wall top and bottom surfaces in the form shown to facilitate engagement with the twisted blade members 110, 120 (FIG. 3) during assembly. (101). These grooves 101 are formed to fit the tabs 111 and 121 provided at both ends of the twisted blade members 110 and 120 as shown in FIGS. 3A and 3B, respectively.

The micro channel structure 100 is preferably manufactured through a micromachining technique such as MEMS, LIGA, etc., for example, an etching process. In particular, when the microchannel structure 100 is directly manufactured by etching through glass, quartz, or the like, or when the microchannel structure 100 is manufactured by using PDMS (polydimethylsiloxane) on a master obtained through a MEMS or LIGA process, etc. In addition, due to the nature of these materials, the surface of the channel structure 100 has a surface potential, and thus, electro-osmosis through an electric field may be used as a driving source of fluid flow.

3A and 3B respectively show a clockwise twisted blade member 110 and a counterclockwise twisted blade member 120 according to the present invention, wherein these two twisted blade members 110, 120 are microchannel structures 100. It includes tabs 111 and 121 at both ends to facilitate assembly. In addition, the twisted blade members 110 and 120 are fixed to the inside of the microchannel structure 100 so that the twisted blade spiral portion 112 and the clockwise direction can be expected to expect the mixing performance of the Kenics Static Mixer. And a twisted blade helical portion 122 in the counterclockwise direction. These three-dimensional twisted blade members 110 and 120 are fabricated through micromachining techniques such as micro-stereolithography (hereinafter referred to as " μ-STL "). In particular, the µ-STL technique is inferior to MEMS and LIGA in surface roughness, but a three-dimensional structure of a complicated shape can be manufactured by modeling and stacking a three-dimensional microstructure into a thin slice. However, the twisted blade members 110 and 120 according to the present invention may be preferable to manufacture by the μ-STL technique because the importance of the surface roughness is not a very important variable.

4A and 4B show the overall configuration and assembly method of the micromixer for chaotic mixing of fluids using the concept of the KENIX static mixer as shown in FIG. 1 according to the present invention. 4A and 4B, the micromixer of the present invention includes an upper microchannel structure 130, a lower microchannel structure 140, and one or more twisted blade members 110, 120. In particular, since the upper and lower micro channel structures 130 and 140 have the same shape, they can be manufactured through the same process. As a result, as shown in FIG. 4B, one or more twisted blade members 110 and 120 may be arranged and assembled according to the purpose of the flow path of the micro mixer made by using the upper and lower micro channel structures 130 and 140. .

The micromixer for chaotic mixing of the fluid produced as described above will include the features of the KENIX static mixer described with reference to FIG. 1 so that the two fluids coming into the micromixer of the present invention are helical portions 112 and 122 of the twist blade member. Not only continue to split in half, but also cross-flow to cause radiation mixing to induce micro level chaotic mixing. In addition, when the microchannel structures 130 and 140 are made of a material including a surface potential such as glass, quartz, or PDMS, not only driving of the flow by pressure but also driving of the flow using an electric field is possible.

On the other hand, the micromixer for chaotic mixing of the fluid according to the present invention can be produced at a time by the micromixer of Figure 4b through the stacking method of the μ-STL technique. That is, the micro mixer for chaotic mixing of FIG. 4B may be manufactured at once in the form of FIG. 1 having various cross-sectional shapes using the μ-STL technique described with reference to FIGS. 3A and 3B.

As described above, the micromixer for chaotic mixing of fluids according to the present invention provides the advantage that the pressure reduction does not occur significantly compared to the microchannels having the same pipe diameter, i.

In addition, the present invention includes a twisted blade element twisted at a predetermined angle in a simple shape and a microchannel structure in which the twisted blade member is arranged to drive a fluid by a pressure or an electric field or the like to mix chaos in the microchannel structure. This provides an advantage that can be realized.

That is, the present invention arranges one or more twisted blade members inside the microchannel structure, and the twisted blade members are arranged by the user in one direction or in a staggered direction, so that the micromixer is driven by the flow of pressure, electric field, or the like. It is possible to induce chaotic mixing in the inside, which significantly increases the mixing performance inside the micromixer, which greatly degrades the mixing performance.

Moreover, the present invention can achieve the advantage that the shape of the twisted blade member is simple to greatly reduce the pressure loss, which is one of the major disadvantages of the conventional manual mixing type micro mixer. In particular, the introduction of the twisted blade members into the microchannel structure is facilitated, thereby facilitating the introduction into micro device manufacturing processes such as biochips.

Although a preferred embodiment of the present invention has been described in detail above, those skilled in the art to which the present invention pertains may make various changes without departing from the spirit and scope of the invention as defined in the appended claims. It will be appreciated that modifications or variations may be made. Therefore, changes in the future embodiments of the present invention will not be able to escape the technology of the present invention.

Claims (6)

In the micro mixer for chaotic mixing the incoming fluid, A microchannel structure and at least one twisted blade member disposed within the microchannel structure and twisted at a predetermined angle in a spiral to chaoticly mix the incoming fluid; The microchannel structure is formed with grooves on the horizontal wall and the vertical wall and grooves on the bottom wall for the twist blade member to be assembled, The twisted blade member has at least two tabs for assembling into the grooves, The micromixer structure is a micromixer for chaos mixing of fluids, characterized in that it is produced through micromachining techniques such as MEMS, LIGA or micro-stereolithography. The micromixer as claimed in claim 1, wherein the helical twist angle of the twist blade member is arbitrary and the groove of the micro channel structure is formed by this arbitrary helical twist angle. The micromixer of claim 1, wherein the cross-sectional shape of the microchannel structure is determined by the micromachining technique. 4. A method according to any one of claims 1 to 3, wherein the twisted blade members are disposed in the microchannel structure in a plurality of twisted blade members in a combination of clockwise and counterclockwise twisted blade members. Micro mixer for chaotic mixing of fluids. 2. The micromixer for chaotic mixing of fluids according to claim 1, wherein the selection of the material of the microchannel structure causes the flow drive of the fluids therein to be via a pressure or an electric field. The micromixer for chaotic mixing of a fluid of claim 1, wherein the entirety of the micromixer structure is manufactured by a predetermined lamination method.