WO2010118637A1

WO2010118637A1 - Microfluidic distribution device, production method and application thereof

Info

Publication number: WO2010118637A1
Application number: PCT/CN2010/000494
Authority: WO
Inventors: 黄岩谊; 席建忠; 王建斌; 周莹
Original assignee: Huang Yanyi; Xi Jianzhong; Wang Jianbin; Zhou Ying
Priority date: 2009-04-14
Filing date: 2010-04-14
Publication date: 2010-10-21
Also published as: CN101533005B; CN101533005A

Abstract

A microfluidic distribution device is provided. The microfluidic distribution device includes a microfluidic distribution chip. The chip comprises at least one microfluidic layer, each of which comprises at least two parallel microfluidic channels or a set of microfluidic channels formed by one microfluidic root channel and its bifurcations. The cross-section area of the microfluidic channel is 1μm²-1mm². Inlets and outlets of the microfluidic channels are in communication with outside, while the other portions of the microfluidic channels are inside the microfluidic distribution chip. A production method and application of the microfluidic distribution device are also provided.

Description

Microfluid distribution device, preparation method thereof and use thereof

The invention relates to the field of micro-test equipment, and more precisely to the field of micro-flow distribution.

Background technique

Most biochemical reactions and cell-based chemical assays, especially large-scale screening assays and life science studies at the single-cell level, are carried out in liquid phases ranging from nanoliters to microliters. The small volume reaction not only reduces the cost of a single reaction, but also increases the reagent concentration for efficient reaction and greatly reduces reagent waste. These tests are often very difficult and require extensive pipetting operations to transfer liquid samples. Now, micro-upgrades of other precision small-volume liquid sample dispensers have been commercialized, but how to further expand to nanoscale is still one of the main challenges in large-scale reactions. On the other hand, some other methods, such as non-contact printing and ultrasonic spray, have been applied to the field of liquid transfer, but these technologies are usually only capable of pipetting other pipetting operations, and the equipment is expensive and difficult to heighten. Parallel integration to accommodate high volume operations.

Microfluidic technology is an ideal platform for upgrading other reactions due to its accurate liquid handling potential. High-volume, miniaturized reaction arrays capable of accurate submicroliter liquid handling have become powerful tools for new drug development, gene detection, protein crystallization, reaction condition screening, and cell-related research. There are several microfluidic pipetting methods that can replace traditional methods, such as highly integrated chips with multi-layer soft lithographically prepared pneumatic valves, and sequential droplet microfluidic chips for parameter screening.

Although these techniques significantly reduce the reaction volume and increase the scale of the reaction, they generally only work in closed reaction spaces such as polydimethylsiloxane (PDMS) micro chambers or liquid plugs, while they still exist. The equipment is expensive, and the operation method is complicated.

Summary of the invention

The object of the present invention is to solve the above technical problems, and to provide a nanoliter microfluidic distribution device suitable for mass testing, can be used in an open space, low in cost, and convenient to use, and the invention also provides a simple and inexpensive The method of preparing the microfluidic distribution device and providing several applications of the device in different fields.

In the present invention, the term "chip" refers to a sheet-like or plate-like object having a certain thickness; it may be a single-layer structure or a multilayer structure; its shape may be any shape, preferably having at least one The shape of the straight side is further preferably trapezoidal, square, or rectangular; the material thereof may be any material, preferably glass, ceramic, silicon, metal, polymer, further preferably a plastic polymer, for example, may be polydimethylsiloxane Alkane (PDMS), acrylonitrile-butadiene-styrene copolymer, polycarbonate (PC), polymethyl methacrylate (PMMA), polyurethane, polyethylene, polypropylene, Polymethylpentene, polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), cyclic polyolefin copolymer (Cyclic Olefin Copolymers; COC) polyvinylidene fluoride, polystyrene, polysulfone, nylon, A styrene-acrylic acid copolymer or a mixture of any two or more of the above.

The term "microfluidic channel" refers to a channel through which a liquid sample disposed inside a microfluidic distribution chip flows, and the liquid sample may flow along the microfluidic channel by capillary force or simultaneously by capillary force and external force, which may be a pumping force. , centrifugal force, vacuum or other similar force that can pull or push the liquid sample along the microfluidic channel.

The term "a microfluidic channel" has the following meaning: When the microfluidic channel is two or more juxtaposed microfluidic channels, the microfluidic channel between the two openings of the same microfluidic channel on the microfluidic distribution chip "microfluidic channel"; when the microfluidic channel is at least one microfluidic channel tree formed by at least one bifurcation of one microfluidic channel, microcirculation between any two adjacent bifurcation points The microfluidic channel between the channel or any one of its openings and its adjacent bifurcation point is "a microfluidic channel".

The term "forked" refers to a microfluidic channel divided into two or more microfluidic channels; "bifurcation" refers to a microfluidic channel divided into two microfluidic channels.

The terms "hydrophilic" and "hydrophobic" refer to the relative concept unless otherwise stated. For example, "the inner surface of the microwell of the microwell chip is coated with a hydrophilic material, and the outer surface of the microwell chip on the side of the microwell is coated with a hydrophobic material", which refers to the side of the microwell chip microwell opening. The outer surface is coated with a material that is more hydrophobic than the material coated on the inner surface of the microwell.

The present invention has been achieved by the following technical solutions. A microfluidic distribution device comprising a microfluidic distribution chip, the microfluidic distribution chip having at least one microfluidic layer; at least two parallel microfluidic channels or at least one of the at least one microfluidic layer a microfluidic channel tree formed by at least one bifurcation of the root microfluidic channel; wherein each of the at least two juxtaposed microfluidic channels has two openings on the microfluidic distribution chip, one of the openings In the microfluidic inlet, the other opening is a microfluidic outlet; in the microfluidic channel tree, the opening of the microfluidic channel on the microfluidic distribution chip is a microfluidic inlet, and the other microfluidic channels formed by the bifurcation are in the microflow The opening on the flow distribution chip is a microfluidic outlet; the microfluidic channel has a cross-sectional area of 1 μ m ² to 1 mm ² , and except for the inlet and the outlet communicating with the outside, the other portions are inside the microfluid distribution chip. In at least two juxtaposed microfluidic channels, each microfluidic channel can be assigned the same liquid sample or a different liquid sample; the external force applied to the liquid sample in the microfluidic channel and the transverse direction of the microfluidic channel can be adjusted. The cross-sectional area is used to adjust the flow rate of the liquid sample in the microfluidic channel. At least one group of microfluidic channels formed by at least one bifurcation of one microfluidic channel, since one microfluidic channel tree has only one microfluidic inlet, the liquid sample in the microfluidic channel of the same microfluidic channel tree is Similarly, the flow rate of the liquid sample in the microfluidic channel can be adjusted by adjusting the magnitude of the external force applied to the liquid sample in the microfluidic channel and the cross-sectional area of the microfluidic channel; while the liquid samples in the different microfluidic channel trees can be the same , can also be different; more than two microfluidic channel trees can be juxtaposed in the same microflow The layers may also be distributed in different microfluidic layers; when more than two microfluidic channel trees are distributed in different microfluidic layers, they may be staggered from each other or may be superimposed on each other.

The microfluidic distribution device can also include a microfluidic carrier chip for use with the microfluidic distribution chip for dispensing a liquid sample thereon. As long as the chip which can accept the liquid sample from the microfluid distribution chip can be used as a microfluidic carrying chip, its shape and material are not required, and may be, for example, a glass piece, a silicon piece, a metal piece, a plastic piece or the like. Preferably, the microwell can be disposed on the microfluidic carrier chip, and the size of the microwell can be set as needed, for example, several nanoliters to several microliters; the arrangement of the microwells and the microfluidic channel outlet on the microfluid distribution chip The arrangement is adapted, for example, if the microfluidic channel outlets on the microfluidic distribution chip are equally spaced on the side walls of the microfluidic distribution chip, the microwells are also arranged in the same flow at equal intervals in the microflow. Hosted on the chip. Further preferably, the microfluidic bearing chip outer surface of the microwell inner surface and the microwell opening side may be coated with a material having different hydrophilic properties, which has the advantages of facilitating the distribution of the liquid sample and preventing different microwells. The liquid samples in between are contaminated with each other. For example, if the liquid sample dispensed is aqueous, the inner surface of the microwell is coated with a hydrophilic material, and the outer surface of the microfluidic bearing chip on the side of the microwell is coated with a hydrophobic material, when flowing from the outlet of the microfluidic channel. When the liquid sample contacts the inner surface of the microwell, the droplets are confined within the microwell due to surface tension and are not carried to the outer surface of the microfluidic bearing chip or other microwells. Conversely, if the liquid sample to be dispensed is oily, the inner surface of the microwell is coated with a hydrophobic material, and the microfluidic side of the microwell opening side is coated with a hydrophilic material to achieve the same effect.

The number of microfluidic channels juxtaposed in the microfluid distribution chip can be set as needed, for example, 10 pieces. Preferably, the parallel microfluidic channels may be arranged in parallel and equally spaced on the microfluid distribution chip; further preferably, the angle between the sidewall plane where the microfluidic channel exit is located and the plane where the microfluid distribution chip is located is one The acute angle, for example, may be from 10 ° to 80 °, such that a liquid sample emerging from the microfluidic channel concentrates to the sharp tip tip under the influence of gravity and surface tension, facilitating the dispensing of the liquid sample to an accurate location.

The microfluidic channel tree in the microfluidic distribution chip is formed by bifurcation of the first microfluidic channel (referred to as "root microfluidic channel") connected to the microfluidic inlet to form more than two new micros Flow channels, and each new microfluidic channel can be forked to form a new microfluidic channel, all of which together form a microfluidic channel tree. Preferably, the bifurcation of the microfluidic channel tree is a bifurcation, and a microfluidic channel is bifurcated to form two new microfluidic channels, and the three microfluidic channels together form a letter Y or a letter T, new The microfluidic channel can be bifurcated. Further preferably, the microfluidic channel tree is bilaterally symmetric with the root microfluidic channel as an axis, and the new microfluidic channel formed by the bifurcation is turned to a direction parallel to the root microfluidic channel through an arc portion, except for the arc portion The other parts of the microfluidic channel are linear. Still more preferably, all of the microfluidic channels have the same cross-sectional area, and the microfluidic outlets are equally spaced on the same sidewall of the microfluidic distribution chip, the plane of the sidewalls and the plane of the microfluid distribution chip The angle is an acute angle, which can be, for example, 10 ° to 80 °. By the above means, the volume of the liquid sample dispensed from the outlet of each microfluidic channel in the same time can be made close to the phase Same.

In addition to the at least one microfluidic layer, at least one microfluidic control layer may be further disposed in the microfluid distribution chip, the microfluidic control layer has a microfluidic control channel, and the microfluidic control channel is disposed at a position corresponding to the microfluidic channel. The valve that opens or closes the microfluidic channel can be controlled. The valve may be an integrated resilient hydraulic valve, in which case the material of the microfluidic dispensing chip should be a flexible material. In this way, the microfluidic channel can be controlled to open or close the microfluidic channel as needed.

When the microfluidic distribution chip is used with the microfluidic carrier chip, it is preferably carried out by a computer-controlled three-position platform, which ensures that the dispensing of the liquid sample is fast and accurate.

The microfluid distribution chip can be prepared by a simple and inexpensive method as follows.

(1) Preparing a hollowed-out visor with a microfluidic channel pattern;

(2) uniformly coating a layer of photoresist on a substrate and baking it to cure;

(3) Exposing the photoresist with ultraviolet light under the occlusion of the visor;

(4) developing the photoresist with a developer to obtain a template having a microfluidic channel pattern;

(5) coating an uncured plastic polymer on the stencil, curing it, removing it from the stencil, and perforating at a suitable position of the microfluidic channel to form a microfluidic inlet;

(6) coating a layer of uncured plastic polymer on the substrate and curing it, bonding it to the side of the polymer layer obtained in step (5) having a microfluidic channel, and bonding The polymer layers together are further cured;

(7) The cured polymer layer is removed from the substrate, and excess polymer is removed along the end of the microfluidic channel to form a microfluidic outlet.

The substrate may be a flat plate having a smooth surface made of any material, for example, a metal sheet, a silicon wafer, a glass sheet, a ceramic sheet, a plastic sheet, etc.; the photoresist is not particularly limited, and the plastic polymer is not particularly limited. For example, it may be polydimethylsiloxane (PDMS), acrylonitrile-butadiene-styrene copolymer, polycarbonate (PC), polymethyl methacrylate (PMMA), polyurethane, polyethylene, poly Propylene, polymethylpentene, polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), polyvinylidene fluoride, polystyrene, polysulfone, nylon, styrene-acrylic acid copolymer or any two or more of the above mixture.

The microfluidic distribution device of the present invention can be applied in various fields such as microfluidics, microanalysis, drug screening, cell detection, and combinatorial chemical reactions.

The technical solutions of the present invention are summarized as follows:

A microfluidic distribution device comprising a microfluidic distribution chip, characterized in that said microfluidic distribution chip has at least one microfluidic layer; said at least one microfluidic layer having at least two juxtaposed microfluidic channels or At least one group consists of a root micro a microfluidic channel tree formed by at least one bifurcation of the flow channel; wherein each of the at least two juxtaposed microfluidic channels has two openings on the microfluidic distribution chip, one of which is micro The flow inlet, the other opening is a micro-flow outlet; in the micro-flow channel tree, the opening of the micro-flow channel on the micro-flow distribution chip is a micro-flow inlet, and the other micro-flow channels formed by the bifurcation are distributed in the micro-flow The opening on the chip is a micro-flow outlet; the micro-flow channel has a cross-sectional area of 1 μ m ² to 1 mm ² , and except for the inlet and the outlet communicating with the outside, the other portions are inside the micro-flow distribution chip.

2. The microfluidic dispensing device of clause 1, wherein the microfluidic dispensing device further comprises a microfluidic carrier chip for use with the microfluidic distribution chip to accept a liquid sample dispensed by the microfluidic dispensing chip.

3. The microfluidic distribution device according to Item 2, wherein the microfluidic carrier chip is provided with at least two microwells that can be used to accommodate the liquid sample dispensed by the microfluid distribution chip, and the arrangement of the microwells The mode is adapted to the arrangement of the microfluidic channel outlets on the microfluidic distribution chip.

4. The microfluidic distribution device according to item 3, characterized in that the bifurcation of the microfluidic channel tree is a bifurcation, and a microfluidic channel is bifurcated to form two new microfluidic channels, the above three The microfluidic channels together form a letter Y or a letter T, and the new microfluidic channel can be bifurcated.

5. The microfluidic distribution device according to Item 3 or 4, wherein the microfluidic channel tree is bilaterally symmetric with the root microfluidic channel as an axis, and the new microfluidic channel formed by the bifurcation is transferred to an arc portion In the direction parallel to the root microfluidic channel, except for the arcuate portion described above, the other portions of the microfluidic channel are linear.

6. The microfluidic distribution device according to item 5, characterized in that the inner surface of the microwell is coated with a hydrophilic material, and the outer surface of the microfluidic bearing chip on the side of the microwell opening is coated with a hydrophobic material; or in the microwell The surface is coated with a hydrophobic material, and the outer surface of the microfluidic bearing chip on the side of the microwell opening is coated with a hydrophilic material.

7. The microfluidic distribution device according to item 6, wherein the microfluidic outlets are equally spaced on the same side wall of the microfluidic distribution chip.

8. The microfluidic dispensing device according to item 7, wherein the plane of the side wall and the plane of the microfluid distribution chip are at an angle of 10° to 80°.

9. The microfluidic distribution device according to item 8, characterized in that all of the microfluidic channels have the same cross-sectional area.

The microfluidic distribution device according to any one of claims 1 to 4, wherein the microfluid distribution chip is made of a flexible material.

11. The microfluidic distribution device according to item 10, wherein the microfluidic distribution chip further comprises at least one microfluidic control layer, the microfluidic control layer has a microfluidic control channel, and the microfluidic control channel corresponds to the microfluidic channel The position has a valve that can control the opening or closing of the microfluidic channel.

12. The microfluidic dispensing device of clause 11, wherein the valve is an integrated resilient hydraulic valve. 13. The method of preparing a microfluidic distribution chip according to Item 1-12, characterized in that the method comprises the following steps:

(8) Preparing a hollowed-out visor with a microfluidic channel pattern;

(9) uniformly coating a layer of photoresist on a substrate and baking it to cure;

(10) exposing the photoresist using ultraviolet light under the shielding of the visor;

(11) developing the photoresist with a developer to obtain a template having a microfluidic channel pattern;

(12) coating an uncured plastic polymer on the stencil, curing it, removing it from the stencil, and perforating at a suitable position of the microfluidic channel to form a microfluidic inlet;

(13) coating a layer of uncured plastic polymer on the substrate and curing it, bonding it to the side of the polymer layer obtained in the step (5) having a microfluidic channel, and bonding The polymer layer is further cured; the cured polymer layer is removed from the substrate, and the excess polymer is removed along the end of the microfluidic channel to form

14. The use of a microfluidic distribution chip according to items 1-12 in the fields of microfluidics, microanalysis, drug screening, cell detection, and combinatorial chemical reactions.

DRAWINGS

Fig. 1 Schematic diagram of microfluid distribution chip with multiple parallel microfluidic channels

Figure 2 Schematic diagram of a microfluidic distribution chip with a set of microflow channel trees

Figure 3 Schematic diagram of another microfluidic distribution chip with a set of microfluidic channel trees

Figure 4 Schematic diagram of the third microfluidic distribution chip with a set of microfluidic channel trees

Figure 5 Schematic diagram of the fourth microfluidic distribution chip with a set of microfluidic channel trees

Fig. 6 Schematic diagram of microfluidic distribution chip with two sets of microfluidic channel trees

Figure 7 Schematic diagram of a microfluid distribution chip with a microfluidic layer and a microfluidic control layer

Figure 8 Schematic diagram of a microfluidic carrier chip with a microwell array

Figure 9 Schematic diagram of the preparation process of a microfluid distribution chip with a set of microfluidic channel trees

Figure 10 Microfluidic distribution device working process diagram

Figure 11 Schematic diagram of the working process of the microfluidic distribution device

Figure 12 Microflow distribution device working process diagram

detailed description

Example 1

The structure of a microfluid distribution chip having a plurality of parallel microfluidic channels will be described in detail below with reference to FIG. Figure 1(a) is a front view of the microfluid distribution chip, Fig. 1(b) is a cross-sectional view along the I - I direction, 11 is a microfluidic channel, 12 is an inlet of the microfluidic channel, and 13 is an exit of the microfluidic channel .

Example 2

The structure of a microfluidic distribution chip having a set of microfluidic channel trees formed by a plurality of bifurcations of a single microfluidic channel will be described in detail below with reference to FIG. Figure 2 (a) is a front view of the microfluid distribution chip, Figure 2 (b) is a cross-sectional view along the I - I direction, 21a is the root microfluidic channel, and 21b is formed by the root microfluidic channel through the bifurcation The new microfluidic channel, 22 is the inlet of the microfluidic channel, and 23 is the outlet of the microfluidic channel. Two new microfluidic channels 21b formed by the bifurcation of the root microfluidic channel form a letter Y shape with the root microfluidic channel 21a.

Example 3

The structure of another microfluid distribution chip having a set of microfluidic channel trees will be described in detail below with reference to FIG. Figure 3 (a) is a front view of the microfluid distribution chip, Figure 3 (b) is a cross-sectional view along the I - I direction, 31a is the root microfluidic channel, and 31b is formed by the root microfluidic channel through the bifurcation The new microfluidic channel, 32 is the inlet of the microfluidic channel, and 33 is the outlet of the microfluidic channel. Two new microfluidic channels 31b formed by the bifurcation of the root microfluidic channel form a letter T shape with the root microfluidic channel 31a.

Example 4

The structure of a third microfluidic distribution chip having a set of microfluidic channel trees will be described in detail below with reference to FIG. Figure 4 (a) is a front view of the microfluid distribution chip, Figure 4 (b) is a cross-sectional view along the I - I direction, 41a is the root microfluidic channel, and 41b is formed by the root microfluidic channel through the bifurcation The new microfluidic channel, 42 is the inlet of the microfluidic channel, and 43 is the outlet of the microfluidic channel. Two new microfluidic channels 31b formed by the bifurcation of the root microfluidic channel form a letter T shape with the root microfluidic channel 31a. The entire microfluidic channel tree is bilaterally symmetric with the root microfluidic channel 41a as an axis, and 41b is turned by an arcuate portion 44 in a direction parallel to the root microfluidic channel. Except for the curved portion 44, the other portions of the microfluidic channel are It is linear. Example 5

The structure of the fourth microfluidic distribution chip having a set of microfluidic channel trees will be described in detail below with reference to FIG. Fig. 5(a) is a front view of the microfluid distribution chip, Fig. 5(b) is a cross-sectional view along the I - I direction, and Fig. 5(c) is a cross-sectional view along the Π - Π direction. The structure of the microfluidic distribution chip in this embodiment is similar to that in the embodiment 4. The difference is that the plane of the sidewall of the microfluidic channel exit is at an acute angle α from the plane where the microfluid distribution chip is located, and flows out from the microfluidic channel. The liquid sample concentrates on the tip of the acute angle under the action of surface tension and gravity, which facilitates the dispensing of the liquid sample to an accurate position.

Example 6

The structure of the microfluid distribution chip having two microfluidic layers and two sets of microfluidic channel trees will be described in detail below with reference to FIG. Description. Fig. 6(a) is a front view of the microfluid distribution chip, Fig. 6(b) is a cross-sectional view along the 1-1 direction, and Fig. 6(c) is a cross-sectional view along the Π-Π direction. The microfluidic channels in the upper microfluidic layer are indicated by solid black lines, while the microfluidic channels in the lower microfluidic layer are indicated by solid gray lines. Two sets of microfluidic channel trees can be assigned different liquid samples, as shown in Figure 6(c). During operation, two different liquid samples are collected and mixed at the lower end of the microfluidic distribution chip.

Example 7

The structure of a microfluid distribution chip having a microfluidic layer and a microfluidic control layer composed of a flexible material will be described in detail below with reference to FIG. Fig. 7 (a) is a front view of the microfluid distribution chip, Fig. 7 (b) is a cross-sectional view taken along the line I - I, and Fig. 7 (c) is a cross-sectional view along the Π - Π direction. The upper layer is a microfluidic control layer, wherein the microfluidic control channel is indicated by a solid black line; the lower layer is a microfluidic layer, wherein the microfluidic channel is indicated by a solid gray line. There are four microfluidic control channels, namely 751, 752, 753 and 754, and there are four microfluidic channels with outlets, namely 731, 732, 733 and 734. The microfluidic control channel has only one opening on the microfluid distribution chip, and the other end is sealed inside the microfluid distribution chip, in which the gas is introduced, and the pressure of the gas can be adjusted as needed. The microfluidic control channel is provided with an enlarged cavity at some locations intersecting the microfluidic channel (as shown by the black square in Figure 7(a), the expanded cavity is the integrated elastic hydraulic pressure of claim 12. Valve), so at these locations, the wall between the microfluidic channel and the microfluidic control channel is thin (as shown in Figure 7(b)). When the air pressure in the microfluidic control channel exceeds a critical value P _e , the enlarged cavity expands, thereby blocking the microfluidic channel at the corresponding position in the lower layer. Figure 7(c) shows the case where the air pressure in the 751 channel does not exceed P _e and the air pressure in the 753 channel exceeds P _e . Thus, by controlling the magnitude of the air pressure in the microfluidic control channel, the opening and closing of each microfluid distribution channel can be freely controlled. For example, if you want to turn the 732 channel on and turn off the other microflow distribution channels, you only need to lower the pressure of the 752 and 754 channels below P _e and raise the pressure of the 751 and 753 channels above P _e. can.

Example 8

The structure of a microfluidic carrying chip having a plurality of microwells will be described in detail below with reference to FIG. Fig. 8(a) is a front view of the microfluidic carrying chip, and Fig. 8(b) is a cross-sectional view along the I - I direction. 81 is a microwell, 82 is the inner surface of the microwell, and 83 is the outer surface of the microwell carrying chip. The arrangement of the microwell on the microfluidic carrier chip should be compatible with the microfluidic distribution chip used. For example, if the microfluid distribution outlets of the microfluidic distribution chip are arranged at equal intervals, the microwell should also be the same. The pitch is arranged on the microfluidic carrier chip. 82 and 83 are coated with materials having opposite hydrophilic properties.

Example 9

Preparation of a microfluidic distribution chip. A method of preparing a microfluid distribution chip including only one microfluidic layer (such as the microfluid distribution chip in the embodiment 1-5) will be described in detail below with reference to FIG. (a) Prepare a 3'' wafer and clean and dry the surface. (b) Apply a layer of photoresist SU-8 of about 100 m on the silicon wafer; prepare a hollowed-out visor with a microfluidic channel pattern, and use 300 mJ/ for the SU-8 under the visor. Cm ² ultraviolet light with a center wavelength of 365 nm Irradiation, then baking SU-8 at 65 °C for 3 minutes, baking at 95 °C for 10 minutes, developing with a developer, and finally baking the wafer at 150 ° C for 3 hours to fully crosslink SU-8 , thereby obtaining a template of the microfluid distribution chip. (c) The template was treated in steam of trimethylchlorosilane for 5 minutes at room temperature, then covered with a layer of 4 mm uncured PDMS, and then cured at 80 ° C for 1 hour to cure PDMS. (d) The cured PDMS is removed from the stencil and perforated at a predetermined location to form a microfluidic inlet. (e) The side of the PDMS layer having the microfluidic channel was bonded to a cured PDMS layer and then cured at 80 ° C overnight to fully cure the PDMS. (f) Use a blade to remove excess PDMS at a suitable location to form a microfluidic outlet.

Example 10

A microfluidic distribution chip having a plurality of microfluidic layers or having a plurality of microfluidic layers and a microfluidic control layer. The preparation method is similar to the preparation method of the microfluidic distribution chip in Example 9. If the structures of the channels of different layers are different, the steps (a) and (b) in Embodiment 9 should be repeated to obtain templates of different patterns, and then the PDMS layers of channels having different structures are respectively prepared by using the respective templates. Finally, the PDMS layers are bonded together and fully cured to form a microfluidic outlet and an inlet. If the channels of the different layers are of the same structure, the same number of PDMS layers can be prepared using the same template, and then the PDMS layers are bonded together and fully cured to form a microfluidic outlet and an inlet.

Example 11

Preparation of a microfluidic carrier chip with a microwell. Prepare a glass plate coated with a chrome film, spin a layer of SU-8 on the chrome film, and use a 150 mJ/cm ² center wavelength of 365 nm for SU-8 under the occlusion of a well-designed visor. Irradiation with ultraviolet light, then baking SU-8 at 65 ° C for 3 minutes, baking at 95 ° C for 10 minutes, developing with a developer, and then baking the glass piece at 150 ° C for 3 hours to make SU-8 fully Cross-linking. The chrome film is etched with an etchant, and the etched chrome film is then used as a mask for etching the glass. Finally, the glass plate was etched with a mixed acid of hydrochloric acid and hydrofluoric acid (molar ratio HC1 _: HF: H ₂ 0 = 1 _: 1 : 2). After the etching is completed, a microwell is formed on the glass plate, and the size of the microwell capacity can be controlled by the size of the mask pattern and the etching time. The outer surface of the microwell carrier chip was modified with 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane to form a hydrophobic outer surface. Specifically, 5 μl of 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane is dissolved in 2.5 ml of toluene to form a solution, 0.8 ml of this solution is spin-coated onto a silicon wafer, and then the solution is printed. On a flat PDMS stamp, the solution coated PDMS stamp plane is contacted with the outer surface of the microwell carrier chip for 20 minutes. The outer surface of the microwell carrier chip is coated with a layer of hydrophobic 1H, 1H, 2H. 2H-perfluorodecyltriethoxysilane with a contact angle of 95°.

Example 12

The operation of the microfluid distribution device will be described in detail below with reference to Figs. A microfluidic distribution chip and a microfluidic carrier chip having a microwell array were prepared in accordance with the methods of Examples 9 and 11, respectively. Microfluidic core with microwell array The structure of the chip is shown in Figure 8. The structure of the micro-flow distribution chip is shown in Figure 4. The microfluidic channel has a cross-sectional dimension of 100 μm×100 m and the microwell has a volume of approximately 120 nanoliters. Since the relative position of the microfluidic distribution chip and the microfluidic carrier chip is critical to the operational accuracy during the operation of the microfluidic distribution device, a computer controlled three-dimensional mobile platform is used to control the movement of the chip. The liquid sample in the microfluidic channel is driven by compressed air, and the velocity of the microfluid distribution can be conveniently adjusted by adjusting the pressure of the compressed air. Figure 10 (a) is the state before the distribution of the microfluid; Figure 10 (b) is the state of the microfluid distribution process, from which it can be clearly seen that the droplets of the liquid sample are hung at the exit of the microfluidic channel; c) is a microfluidic carrier chip to which a liquid sample is dispensed, and the distribution mode is interlaced; FIG. 10(d) is an enlarged view of a portion of the dotted line in FIG. 10(c); FIG. 10(e) is a solution of a fluorescein solution. Fluorescence micrograph of a microfluidic carrier chip. The liquid sample of a few nanoliters to several hundred nanoliters can be accurately dispensed using the microfluidic dispensing device of this embodiment, and when 115 nanoliters of the liquid sample is dispensed at a time, the error between the different channels is less than 6%.

Figure 11 details the operation of the microfluidic distribution device, the liquid sample dispensed being an aqueous solution of potassium thiocyanate. Fig. 11(a): Under the control of the three-dimensional platform, the microfluidic outlet of the microfluidic distribution chip moves toward the microwell; Fig. 11(b): generates a droplet driven by pulse pressure; Fig. 11(c): liquid The droplets continue to increase, contact and infiltrate into the hydrophilic inner surface of the microwell; Figure 11(d): The microfluidic distribution chip continues to move forward and the droplets remain in the microwell. It can be seen from this process that liquid samples in adjacent microwells do not contaminate each other.

Example 13

The working process of the microfluidic distribution device. A schematic diagram of the structure of the microfluid distribution chip in the microfluidic distribution device of this embodiment is shown in FIG. Figure 12 clearly shows the operation of the microfluidic distribution device. Figure 12 (a): Appearance of the microfluidic distribution chip with 8 distribution channels; Figure 12 (b): The first microfluidic channel is opened from the right, while the other microfluidic channels are closed; Figure 12 (c) ): The third microfluidic channel is opened from the right, while the other microfluidic channels are turned off; Figure 12(d)-(f): The graphic letter "N" formed by dispensing the liquid sample at different locations using the microfluidic distribution chip ", jagged and "PKU".

Claims

A microfluidic distribution device comprising a microfluidic distribution chip, characterized in that said microfluidic distribution chip has at least one microfluidic layer; said at least one microfluidic layer having at least two juxtaposed microfluidic channels or At least one set of microfluidic channel trees formed by at least one bifurcation of one microfluidic channel; wherein each of the at least two juxtaposed microfluidic channels has two openings on the microfluidic distribution chip One of the openings is a microfluidic inlet, and the other opening is a microfluidic outlet; in the microfluidic channel tree, the opening of the microfluidic channel on the microfluidic distribution chip is a microfluidic inlet, and the other is formed by a bifurcation. The opening of the microfluidic channel on the microfluidic distribution chip is a microfluidic outlet; the microfluidic channel has a cross-sectional area of 1 μ m ² to 1 mm ² , and other parts are distributed in the microfluid except that the inlet and the outlet communicate with the outside world. The inside of the chip.

2. The microfluidic dispensing device of claim 1 wherein the microfluidic dispensing device further comprises a microfluidic carrier chip for use with the microfluidic distribution chip to accept a liquid sample dispensed by the microfluidic dispensing chip.

3. The microfluidic distribution device according to claim 2, wherein the microfluidic carrier chip is provided with at least two microwells that can be used to accommodate the liquid sample dispensed by the microfluidic distribution chip, and the arrangement of the microwells The mode is adapted to the arrangement of the microfluidic channel outlets on the microfluidic distribution chip.

4. The microfluidic distribution device according to claim 3, wherein the bifurcation of the microfluidic channel tree is a bifurcation, and a microfluidic channel is bifurcated to form two new microfluidic channels, the three The microfluidic channels together form a letter Y or a letter T, and the new microfluidic channel can be bifurcated.

The microfluidic distribution device according to claim 3 or 4, wherein the microfluidic channel tree is bilaterally symmetric with the root microfluidic channel as an axis, and the new microfluidic channel formed by the bifurcation is turned to an arc portion In the direction parallel to the root microfluidic channel, except for the above-mentioned curved portion, the other portions of the microfluidic channel are linear.

6. The microfluidic distribution device according to claim 5, wherein the inner surface of the microwell is coated with a hydrophilic material, and the outer surface of the microfluidic bearing chip on the side of the microwell opening is coated with a hydrophobic material; or the microwell The surface is coated with a hydrophobic material, and the outer surface of the microfluidic bearing chip on the side of the microwell opening is coated with a hydrophilic material.

7. The microfluidic distribution device according to claim 6, wherein the microfluidic outlets are equally spaced on the same side wall of the microfluidic distribution chip.

8. The microfluidic dispensing device according to claim 7, wherein the plane of the side wall and the plane of the microfluidic distribution chip are at an angle of 10[deg.] to 80[deg.].

9. The microfluidic distribution device according to claim 8, wherein all of the microfluidic channels have the same cross-sectional area.

The microfluidic distribution device according to any one of claims 1 to 9, wherein the microfluidic distribution chip is composed of a flexible material.

11. The microfluidic distribution device according to claim 10, wherein the microfluid distribution chip further comprises at least one micro The flow control layer, the micro flow control layer has a micro flow control channel, and the micro flow control channel is provided with a valve that can control the opening or closing of the micro flow channel at a position corresponding to the micro flow channel.

12. The microfluidic dispensing device of claim 11 wherein the valve is an integrated resilient hydraulic valve.

13. A method of fabricating a microfluidic distribution chip according to any of claims 1-12, characterized in that the method comprises the following steps:

(1) Preparing a hollowed-out visor with a microfluidic channel pattern;

14. Use of a microfluidic dispensing chip according to claims 1-12 in the fields of microfluidics, microanalysis, drug screening, cell detection, combinatorial chemical reactions.