CN211754501U

CN211754501U - Laminated passive micro mixer

Info

Publication number: CN211754501U
Application number: CN201921728314.8U
Authority: CN
Inventors: 章安良
Original assignee: Wuyi University
Current assignee: Wuyi University
Priority date: 2019-10-15
Filing date: 2019-10-15
Publication date: 2020-10-27
Anticipated expiration: 2029-10-15

Abstract

The utility model discloses a laminated passive micro mixer, which comprises a plurality of PDMS thin curing layers and a plurality of spacing paper sheets, wherein a channel with two inlets and one outlet is arranged on one PDMS thin curing layer, the rest PDMS thin curing layers are provided with channels with an inlet and an outlet, the PDMS thin curing layers with two inlets and an outlet are sequentially stacked from bottom to top to form a laminated structure, the upper PDMS thin curing layer is provided with the channels with the two inlets and the outlet, the upper channel and the lower channel are staggered, the spacing paper sheets are positioned between the edges of the two adjacent PDMS thin curing layers to form a micro cavity between the central areas, the upper channel and the lower channel are communicated through the micro cavity, the peripheral walls of the two adjacent PDMS thin curing layers are hermetically connected, the two inlets of the uppermost channel are respectively used as the inlets, and the outlet of the lowermost channel is used as the outlet; the mixing device has the advantages of high mixing efficiency, simple structure, convenient process and low process cost.

Description

Laminated passive micro mixer

Technical Field

The utility model relates to a micro mixer in the micro-fluidic chip especially relates to a passive micro mixer of stromatolite.

Background

The micro-fluidic chip integrates the conventional laboratory analysis instrument unit on a small substrate to complete the biochemical analysis function of the conventional laboratory, and has the advantages of small volume, less consumption of biochemical reagents, short analysis time and higher analysis automation, so that the micro-fluidic chip is emphasized by experts at home and abroad since the invention, is rapidly developed, gradually permeates into a plurality of subject fields, further influences the aspects of life of people, and has a great deal of literature and related results of the micro-fluidic chip every year. At present, the microfluidic chip has been widely applied in the fields of DNA analysis, protein analysis, drug detection, environmental monitoring, food safety and the like.

The microfluid mixing is an indispensable basic operation unit of the microfluidic chip, and reaction liquid must be fully mixed before the biochemical reaction is carried out for microfluidic analysis, so that reliable analysis precision can be achieved. Therefore, the micro-fluidic chip experts and scholars put a lot of effort and research the structure of the micro-mixer and the manufacturing method thereof continuously so as to reduce the manufacturing cost and improve the mixing efficiency, and invent the manufacturing method and structure of the micro-mixer with different mechanisms.

The micromixers are classified into two major types according to their energy supply, and the micromixers requiring no external energy supply are called passive micromixers, while the mixers requiring external energy supply are active micromixers. The active micromixer has various forms according to different energy sources, and the manufacturing method and the structure of the micromixer are different accordingly. Common active micromixers mainly include electromagnetic drive micromixers, thermal expansion micromixers, ultrasonic drive micromixers, mechanical agitation, electric drive micromixers, and the like. The active micromixer has the advantages of high mixing efficiency and high mixing speed, but has the common defects of relatively complex structure, volume increase caused by external energy supply, analysis cost improvement and small-size and automatic development direction with the micro-flow analysis. Thus, in some instances, passive micromixers function. The passive micro mixer does not need external energy supply, does not need an off-chip unit, has small volume and reduces the analysis cost.

Earlier simple passive micromixers appeared to be cross, T-shaped micromixers. The micro mixer is used for manufacturing a cross-shaped or T-shaped cross micro channel by a soft lithography or die casting method, microfluid to be mixed is input at two input ports, and is converged into a micro channel after passing through the cross-shaped or T-shaped cross micro channel, and the two microfluids are diffused in the same converged micro channel to realize passive mixing of the two microfluids. Such a micromixer has a simple structure, but the mixing efficiency needs to be further improved.

In order to improve the mixing effect of the passive micro mixer, when a T-shaped or cross-shaped micro mixer is manufactured, the length of the converged micro channel is often lengthened to ensure that the mixture is fully mixed; in addition, while the length of the micro-channel for mixing is increased, structures with different patterns are designed inside the micro-channel for mixing to improve the mixing efficiency, but the mixing efficiency of the passive micro-mixer is improved by changing the internal physical structure of the micro-channel, so that the process cost of the micro-mixer is increased, and improvement is needed. Such as: journal "Science, Science" vol 295, vol.1, 647-page 651 discloses a "microchannel unordered mixer, photonic mixer for microchannels" in 2002, which adopts an MEMS technology to design a cross fishbone-shaped groove at the bottom of a microchannel, namely, a row of fishbone strip-shaped patterns are designed by the MEMS technology, then a microchannel with fishbone-shaped at the bottom is manufactured by a die casting method, and is bonded and connected with an inlet and an outlet to form a passive micromixer with a special structure inside. The passive micro-mixer adopts a fishbone-shaped structure, so that the microfluid generates turbulence when passing through, the diffusion chance among mixed liquid is increased, and compared with the traditional method for improving the mixing efficiency by increasing the length of a micro-channel, the mixing efficiency of the mixed liquid is greatly improved. The passive micro mixer has the disadvantages of increasing process steps, having higher process requirements on template manufacturing, improving the manufacturing conditions and the process cost of the micro mixer, and being a challenge especially for common laboratories under the condition of limited conditions.

Disclosure of Invention

The utility model aims to solve the technical problem that a stromatolite passive micromixer is provided, its mixing efficiency is high, and simple structure, convenient, the low technological cost of technology.

The utility model provides a technical scheme that above-mentioned technical problem adopted does: a laminated passive micromixer is characterized by comprising a plurality of PDMS thin curing layers and a plurality of spacing paper sheets, wherein a channel with two inlets and an outlet is arranged on one PDMS thin curing layer in a penetrating manner from top to bottom, a channel with one inlet and one outlet is arranged on the other PDMS thin curing layer in a penetrating manner from top to bottom, a laminated structure is formed by sequentially laminating one PDMS thin curing layer and one spacing paper sheet from bottom to top, the PDMS thin curing layer with two inlets and one outlet is arranged on the uppermost part in the laminated structure, the positions of the channels on the two adjacent PDMS thin curing layers are staggered, the spacing paper sheets are positioned between the edges of the two adjacent PDMS thin curing layers, so that a microcavity is formed between the central areas of the two adjacent PDMS thin curing layers, and the channels on the two adjacent PDMS thin curing layers are communicated through the microcavity, the peripheral walls of two adjacent PDMS thin curing layers are connected in a sealing mode, two inlets of a channel on the PDMS thin curing layer at the uppermost position in the laminated structure are respectively used as input ports, and an outlet of a channel on the PDMS thin curing layer at the lowermost position in the laminated structure is used as an output port.

The channels on the uppermost PDMS thin curing layer in the laminated structure are T-shaped or Y-shaped channels, and the channels on the rest PDMS thin curing layers are vertical through channels. Since two input ports are required for the passive micromixer, the channel on the uppermost PDMS thin cured layer has two input ports, so that the channel on the uppermost PDMS thin cured layer can be designed to be T-shaped or Y-shaped.

The aperture of the channel on the PDMS thin curing layer is 100-200 microns. In contrast, the smaller the pore size of the channel, the better the mixing effect, and the pore size of the channel can be designed to be 120 μm in general.

The channels on the PDMS thin solidified layers are positioned at one corner end of the PDMS thin solidified layers, and the channels on two adjacent PDMS thin solidified layers are staggered in a diagonal direction when the PDMS thin solidified layers are stacked. The channels are designed at one corner of the PDMS thin cured layer, so that the two channels can be diagonally staggered when the two channels are stacked to achieve the best mixing effect, and the path formed by the two channels is the longest when the two channels are diagonally staggered.

The interval paper sheets are in a frame shape and are arranged between the edges of the two adjacent PDMS thin curing layers. In the actual processing, a common a4 paper can be directly cut into the paper with the same length and width as those of the PDMS thin curing layer, and then the middle part is hollowed out to form a frame-shaped spacing paper sheet, and the hollowed-out part is positioned between the central areas of two adjacent PDMS thin curing layers to form a micro-cavity.

The width of the frame edge of the spacing paper sheet is 1-2 mm. The rim width of the spacer sheet is defined to maximize the volume of the microcavity.

And the outer peripheral walls of the two adjacent PDMS thin curing layers are coated with gel-state PDMS, and the gel-state PDMS is cured to form a sealing ring to realize sealing connection. The effect of sealing and connecting the peripheral walls of two adjacent PDMS thin solidified layers by adopting PDMS is optimal.

And the input port and the output port are respectively led out with a thin hose.

Compared with the prior art, the utility model has the advantages of:

1) the laminated passive micro mixer is characterized in that a plurality of PDMS thin curing layers are sequentially laminated together, and the positions of the channels on two adjacent PDMS thin curing layers are staggered, so that a long microchannel is formed by all the channels and the micro cavities formed between the central areas of the two adjacent PDMS thin curing layers, namely the length of the microchannel is increased in the space direction, the mixture can be fully mixed, and the mixing efficiency is high; and the space of the micro-cavity is larger, so that the mixing effect is improved.

2) The laminated passive micromixer increases the length of the microchannel in the space direction, can reduce the length dimension of the passive micromixer to the minimum, and does not increase the length of the microchannel by increasing the length dimension of the passive micromixer.

3) The laminated passive micro mixer improves the mixing efficiency by increasing the length of the micro channel, avoids expensive process equipment required by manufacturing the internal physical structure of the passive micro mixer by adopting an MEMS technology, and solves the problem that a micro-flow micro mixing unit is difficult to develop because no corresponding expensive equipment is available in the common laboratory research.

4) The laminated passive micro mixer has the advantages of simple structure, convenient process and low process cost.

Drawings

Fig. 1 is a schematic structural diagram of a stacked passive micromixer according to a first embodiment;

fig. 2 is a schematic view of a structure in which the top 2 PDMS thin cured layers in the stacked passive micromixer according to the first embodiment are connected;

fig. 3 is a schematic cross-sectional structure of fig. 2.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments.

The laminated passive micromixer proposed in this embodiment, as shown in the figure, comprises 6 PDMS (polydimethylsiloxane) thin cured layers 1 and 5 pieces of spacing paper sheets 2, wherein a channel 3 with two inlets and an outlet is arranged on one PDMS thin cured layer 1 in a penetrating manner, a channel 3 with one inlet and one outlet is arranged on the other PDMS thin cured layers 1 in a penetrating manner, a laminated structure is formed by sequentially stacking one PDMS thin cured layer 1 and one spacing paper sheet 2 from bottom to top, the PDMS thin cured layer 1 with the channel 3 with two inlets and one outlet is arranged at the top in the laminated structure, the positions of the channels 3 on two adjacent PDMS thin cured layers 1 are staggered, the spacing paper sheets 2 are located between the edges of two adjacent PDMS thin cured layers 1, so that a microcavity 4 is formed between the central regions of two adjacent PDMS thin cured layers 1, and the channels 3 on two adjacent PDMS thin cured layers 1 are communicated through the microcavity 4, the peripheral walls of two adjacent PDMS thin cured layers 1 are hermetically connected, two inlets of the channel 3 on the uppermost PDMS thin cured layer 1 in the stacked structure are respectively used as input ports 51, an outlet of the channel 3 on the lowermost PDMS thin cured layer 1 in the stacked structure is used as an output port 52, and a thin hose (not shown in the figure) is respectively led out from the input ports 51 and the output port 52.

In the present embodiment, the channels 3 on the uppermost PDMS thin cured layer 1 in the stacked structure are Y-shaped channels, and the channels 3 on the remaining PDMS thin cured layers 1 are vertical through channels. Since two input ports 51 are required for the passive micromixer, the channel 3 on the uppermost PDMS thin cured layer 1 has two input ports, so that the channel 3 on the uppermost PDMS thin cured layer 1 can be designed into a Y-shaped structure, a T-shaped structure, or the like.

In the embodiment, the pore diameter of the channel 3 on the PDMS thin cured layer 1 is 100 to 200 micrometers, and relatively speaking, the smaller the pore diameter of the channel 3, the better the mixing effect, and generally, the pore diameter of the channel 3 can be designed to be 120 micrometers.

In this embodiment, the channels 3 of the PDMS thin cured layer 1 are located at one corner end of the PDMS thin cured layer 1, and the channels 3 of two adjacent PDMS thin cured layers 1 are diagonally staggered when stacked. The channels 3 are formed at one corner of the PDMS thin cured layer 1, so that the two upper and lower channels 3 may be diagonally staggered when the channels 3 are diagonally staggered, and the path formed by the upper and lower channels 3 is the longest when the channels are diagonally staggered, in order to achieve the best mixing effect when the PDMS thin cured layer 1 is stacked.

In the present embodiment, the spacing paper sheet 2 is in a frame shape, and the spacing paper sheet 2 is disposed between the edges of two adjacent PDMS thin cured layers 1. In actual processing, a common a4 paper may be cut into pieces having the same length and width as those of the PDMS thin cured layer 1, and then the middle portion of the pieces may be hollowed out to form a frame-shaped spacing paper piece 2, and the hollowed-out portion is located between the central regions of two adjacent PDMS thin cured layers 1 to form a micro-cavity 4.

In the present embodiment, the width W of the frame edge of the spacing paper piece 2 is 1-2 mm, for example, 1.5 mm, and the width W of the frame edge of the spacing paper piece 2 is defined to maximize the volume of the micro-cavity 4.

In this embodiment, the outer peripheral walls of two adjacent PDMS thin cured layers 1 are coated with gel-state PDMS, and the gel-state PDMS is cured to form the sealing ring 6 to achieve sealing connection. The effect of sealing and connecting the peripheral walls of two adjacent PDMS thin solidified layers 1 by PDMS is optimal.

When the laminated passive micro mixer is used, microfluid to be mixed enters a sample through two input ports 51 respectively, the microfluid enters a 1 st micro cavity after passing through a 1 st channel, passive mixing is realized while transportation, the microfluid reaches a 2 nd micro cavity through a 2 nd channel, transportation and mixing are realized in each channel and each micro cavity, and finally, the microfluid is transported to a subsequent operation unit of a microfluidic analysis device through a 6 th channel to an output port 52 for microfluidic operation, so that microfluidic analysis is completed.

The manufacturing method of the laminated passive micromixer comprises the following steps:

the method comprises the following steps: and manufacturing a plurality of PDMS thin curing layers with the same size, wherein a channel with two inlets and one outlet is formed in one PDMS thin curing layer in a penetrating manner from top to bottom, and a channel with one inlet and one outlet is formed in the other PDMS thin curing layers in a penetrating manner from top to bottom.

Here, the specific process of the step one is as follows:

vertically placing a fine metal wire with the diameter of 100-200 microns in a container; then pouring uncured PDMS into the container; then, curing by using a constant temperature box; taking out the solidified body, and extracting the fine metal wires; finally, the solidified body is sliced according to the required size (such as the thickness of 1-2 mm) to obtain a plurality of PDMS thin solidified layers with channels with one inlet and one outlet, and the channels on the PDMS thin solidified layers are positioned at one corner end.

Manufacturing a Y-shaped structure by using a fine metal wire with the diameter of 100-200 microns, and placing the manufactured metal wire structure in a container; then pouring uncured PDMS into the container, so that the height of the uncured PDMS is the required size (for example, the thickness is 1-2 mm) of the PDMS thin curing layer; then, curing by using a constant temperature box; the solidified body was then removed and the thin wire was extracted to obtain a thin solidified layer of PDMS having a channel with two inlets and one outlet, the channel in the thin solidified layer of PDMS being located at one corner.

Step two: and manufacturing a plurality of frame-shaped interval paper sheets with the outer frame size consistent with the size of the PDMS thin curing layer and the frame edge width of 1-2 mm.

Step three: the PDMS thin curing layers with the two inlets and the outlet and the channels on the two adjacent PDMS thin curing layers are communicated through the micro-cavities formed between the central areas of the two PDMS thin curing layers at the top in the laminated structure.

Step four: and coating gel-state PDMS between the peripheral walls of two adjacent PDMS thin curing layers, curing (the curing process can be realized by using a constant temperature box), and forming a sealing ring to realize sealing connection.

Step five: and taking two inlets of the channel on the topmost PDMS thin curing layer in the laminated structure as input ports and leading out the thin hoses, and taking an outlet of the channel on the bottommost PDMS thin curing layer in the laminated structure as an output port and leading out the thin hoses.

Claims

1. A laminated passive micromixer is characterized by comprising a plurality of PDMS thin curing layers and a plurality of spacing paper sheets, wherein a channel with two inlets and an outlet is arranged on one PDMS thin curing layer in a penetrating manner from top to bottom, a channel with one inlet and one outlet is arranged on the other PDMS thin curing layer in a penetrating manner from top to bottom, a laminated structure is formed by sequentially laminating one PDMS thin curing layer and one spacing paper sheet from bottom to top, the PDMS thin curing layer with two inlets and one outlet is arranged on the uppermost part in the laminated structure, the positions of the channels on the two adjacent PDMS thin curing layers are staggered, the spacing paper sheets are positioned between the edges of the two adjacent PDMS thin curing layers, so that a microcavity is formed between the central areas of the two adjacent PDMS thin curing layers, and the channels on the two adjacent PDMS thin curing layers are communicated through the microcavity, the peripheral walls of two adjacent PDMS thin curing layers are connected in a sealing mode, two inlets of a channel on the PDMS thin curing layer at the uppermost position in the laminated structure are respectively used as input ports, and an outlet of a channel on the PDMS thin curing layer at the lowermost position in the laminated structure is used as an output port.

2. The laminated passive micromixer of claim 1, wherein said channels on the uppermost of said PDMS thin cured layers in said laminated structure are T-shaped or Y-shaped channels, and said channels on the remaining PDMS thin cured layers are vertical through channels.

3. The laminated passive micromixer according to claim 2, wherein the pore size of the channels on the PDMS thin cured layer is 100 to 200 μm.

4. A laminated passive micromixer according to any one of claims 1 to 3, wherein said channels in said thin cured layers of PDMS are located at one corner of said thin cured layers of PDMS, and said channels in two adjacent thin cured layers of PDMS are diagonally offset when laminated.

5. The laminated passive micromixer of claim 1, wherein said spacer paper sheets are in the form of frames, and said spacer paper sheets are disposed between the edges of two adjacent said thin cured layers of PDMS.

6. The laminated passive micromixer according to claim 5, characterized in that the width of the rim of said spacer paper sheet is 1-2 mm.

7. The laminated passive micromixer of claim 1, wherein said gel-state PDMS is coated between the outer peripheral walls of two adjacent thin cured layers of PDMS, and cured to form a sealing ring for sealing connection.

8. A laminated passive micromixer according to claim 1 wherein fine flexible tubes lead from said input port and said output port, respectively.