CN106179549B - Micro-fluidic chip and application thereof - Google Patents

Abstract

The invention discloses a microfluidic chip, which can realize automatic sample injection of multiple parallel reaction channels and stepwise concentration control. The microfluidic chip rotates on the centrifugal force platform, and by adjusting the speed, the sample in the sample chamber enters the spiral channel and flows in the spiral channel; by adjusting the size of the centrifugal force and the size structure of the metering valve, the sample entering the mixing chamber is controlled. order and volume. The invention also discloses a method based on the device, and a microfluidic chip structure corresponding to various liquids, including a plurality of sample chambers and a plurality of spiral channels. By adjusting the centrifugal force on the microfluidic chip, the invention realizes the automatic multi-sample injection and the stepped concentration control device on the microfluidic chip, and has a simple structure and convenient operation.

Description

A microfluidic chip and its application

technical field

The invention relates to the technical field of microfluidics, in particular to a device and method for automatic sample injection and stepwise concentration control of multiple parallel reaction channels on a microfluidic chip.

Background technique

The centrifugal force-driven microfluidic chip uses the centrifugal force generated by the microfluidic chip in circular motion as the driving force of the liquid flow, and adjusts and controls the dynamic characteristics of the fluid by changing the chip rotation speed and designing different channel configurations. . Centrifugal force drive is a relatively unique technology in microfluidic drive technology. Compared with other microfluidic drive methods, it has the advantages of convenient processing, low cost, high integration, high throughput, and no pulsation of fluid flow. The centrifugal force has a wide driving range, and the entire chip can be driven at the same time. The driving implementation is simple, no additional pump is required, and the existing optical disc drive can even be directly used. Microfluidic analysis technology integrates functional components such as microvalves, microchannels, microreaction chambers, and micropumps on chip materials like integrated circuits through micromachining technology. Molecular-level detection is more and more widely used in the fields of chemistry and biology because of its advantages in low consumption of materials and reagents, in-situ analysis, and rapid real-time.

When it is necessary to realize the mixing of specific concentrations of different liquids on the centrifugal force-driven microfluidic chip for experiments and characteristic measurement, the existing solutions either use manual configuration, which is time-consuming and inefficient; Either interrupt the experiment after running one step on the chip and reload and run the next step to achieve the above. In addition, manual sample injection is used, the operation is complicated, errors are easily introduced, and the cost is high.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is designed to overcome the deficiencies of the prior art. The method can realize the quantitative mixing of n (n≥1) kinds of liquids in the same microfluidic chip under the condition of uninterrupted experiment, and detect the mixture with the help of detection equipment.

The present invention adopts the following technical solutions for solving the above-mentioned technical problems:

According to the present invention, a microfluidic chip for realizing quantitative mixing of n (n≥1) kinds of liquids in the same microfluidic chip includes a chip body, a spiral channel, a sample chamber, a waste liquid chamber, a metering chamber, Microvalve, microfluidic channel, liquid mixing chamber; for the convenience of description, the same radius line from the center of the chip body to the edge is used as a reference, the position relatively close to the center of the chip body is called the proximal side, and the position relatively far from the center of the chip body Called the telecentric side, n spiral channels are set on the chip body, n is an integer greater than or equal to 1, the n spiral channels are distributed on the chip body at intervals, and each spiral channel starts from a position close to the center of the chip body The spiral extends to a position close to the edge of the chip body and terminates. The initial end is provided with a sample chamber, the termination end is provided with a waste liquid chamber, and a metering chamber is arranged along the outer edge of the spiral channel. The proximal side of the metering chamber is communicated with the spiral channel. The distal side of the chamber is connected with a micro-valve, the micro-valve is opened in the helical channel on the distal side of the micro-valve, the distal side of the metering chamber of the outermost helical channel is provided with a micro-valve and a micro-fluidic channel in sequence, and a liquid-mixing chamber is set on the distal side of the micro-fluidic channel .

Through the design of the sample chamber, spiral channel, metering chamber, microvalve, mixing chamber and waste liquid pool, etc., the centrifugal force received by the device is adjusted so that the sample in the sample chamber enters the corresponding spiral channel, and the speed of the rotating platform is adjusted The flow state of the liquid sample on the microfluidic chip is controlled by the adjustment of the microfluidic chip, so that the sample enters and fills the metering chamber under the action of centrifugal force, and the excess liquid flows into the waste liquid pool, and then under the control of the capillary microvalve structure, to "from the outer layer" The sequence from the metering chamber of the spiral channel to the metering chamber of the inner spiral channel” enters the mixing chamber in turn. By designing the size of the metering chamber, the volume entering the mixing chamber is controlled; by designing the microvalve, the sequence of the samples entering the mixing chamber is realized. In this way, solutions with different concentrations can be integrated on the chip to achieve the purpose of automatic sample injection and specific concentration control of multiple parallel reaction channels. Simple structure and convenient operation.

For the n spiral channels set on the microfluidic chip, n can also be an integer greater than or equal to 2. In addition, the number n of the spiral channels can be increased at a maximum until the volume of the microfluidic chip can no longer be increased.

As a further optimized solution of the microfluidic chip of the present invention, ventilation holes can be provided on the spiral channel, the sample chamber and the waste liquid chamber.

On the microfluidic chip provided by the present invention, the microvalves of different spiral channels from outside to inside can move the fluid into the outside measuring chamber or mixing chamber according to the required sequence through the design of their thresholds. For example, the resistance of each micro-valve can be designed so that the resistance of each micro-valve is from the distal side to the micro-valve on the proximal side, and its threshold value gradually increases, so that when the rotation rate of the microfluidic chip increases, the micro-valve at the distal end can be realized before the proximal side. The micro-valve at the end is opened, so that when the rotation rate of the microfluidic chip increases, the liquid in the measuring chamber on the proximal side can enter into the measuring chamber of the helical channel on the distal side in turn.

By setting the volume of the measuring liquid chamber as required, different liquids can be mixed in the required proportion in the liquid mixing chamber.

Although the drawings of the microfluidic chip provided by the present invention are all circular, the shape of the chip can be designed as a square, ellipse, rectangle, triangle and other acceptable geometric shapes (including asymmetrical geometry).

When it is necessary to realize the quantitative mixing of n kinds of liquids and detect the mixture with the help of detection equipment, the following steps can be performed:

(1) respectively adding the liquid to be mixed into the sample chamber of the microfluidic chip with n spiral channels;

(2) The microfluidic chip is placed on the rotating platform, the microfluidic chip is rotated, the liquid enters the spiral channel, and fills the multiple metering chambers located on the distal side of the spiral channel in turn, and the excess liquid enters the spiral channel and terminates end of the waste chamber;

(3) Gradually speed up the rotation rate of the microfluidic chip, so that the liquid in the metering chamber starts with the liquid in the metering chamber of the most distal spiral channel, and the liquid in the metering chamber of the nearest spiral channel last. From the outside to the inside, it enters the mixed liquid chamber in turn, and the excess liquid enters the waste liquid chamber;

(6) Each liquid is mixed and reacted in the mixed liquid chamber, and the liquid in the mixed liquid chamber is detected by a detection device.

Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects: the present invention is based on a microfluidic chip device on a rotating platform, and by changing the rotation speed of the rotating platform, the flow state of the liquid sample in the spiral channel is controlled , control the liquid to enter and fill the metering chamber, and control the liquid sample to enter the mixing chamber sequentially from outside to inside by adjusting the opening and closing of the micro-valve. Through the design of the size and structure of the metering chamber and the microvalve, the automatic injection of various samples and the solution with a stepwise change in concentration are realized. The specific size of the corresponding structure can be adjusted according to the application of experimental objects and operating samples, so as to adapt to different types of experimental operations. The invention realizes the automatic injection of samples in multiple parallel reaction channels and the control of specific concentrations, and the mixed liquid chambers where solutions of different concentrations are located are distributed on a microfluidic chip, which can be simultaneously detected by a detection device. The structure is simple and the operation is convenient.

The trajectory of the spiral channel can be obtained through various trajectory equations. For example, the trajectory (X, Y) parameter equation of the spiral channel can be:

X _t =r+R*t/2*π*cos(t) Y _t =r+R*t/2*π*sin(t)

t is the radian angle between the trajectory of the point and the X axis, r is the distance between the start point of the spiral channel and the center of the chip, and (r+R) is the distance between the end point of the spiral channel and the center of the chip.

Description of drawings

Fig. 1 is a schematic diagram of the microfluidic chip when the number "n" of the spiral channels on the microfluidic chip of the present invention is 1.

2 is a top view of the microfluidic chip when the number "n" of the spiral channels on the microfluidic chip of the present invention is 1.

3 is a schematic diagram of the microfluidic chip when the number "n" of the spiral channels on the microfluidic chip of the present invention is 2.

FIG. 4 is a schematic diagram of the microfluidic chip when the number “n” of the spiral channels on the microfluidic chip of the present invention is 3. FIG.

5 is a schematic diagram of the microfluidic chip when the number "n" of the spiral channels on the microfluidic chip of the present invention is 4.

Fig. 6 is the local spiral channel, the volume chamber, the microvalve, the microfluidic channel and the mixed liquid chamber on the microfluidic chip when the number "n" of the spiral channels on the microfluidic chip of the present invention is 4. Enlarge the image.

Reference numerals: 1-chip body, 2-sample chamber, 3-metering chamber, 4-spiral channel, 5-microvalve, 6-microfluidic channel, 7-liquid mixing chamber, 8-waste liquid chamber, 9-motor, 10-vent, 11-spindle.

Detailed ways

The technical scheme of the present invention will be further described below in conjunction with the accompanying drawings:

As shown in Figures 1 and 2, it is a microfluidic chip of the present invention. The chip body is provided with a spiral channel, and the corresponding sample chamber, spiral channel, waste liquid chamber, metering chamber, microvalve, microcirculation channel and mixing chamber. The sample chamber is located near the center of the chip, the waste liquid chamber is located near the edge of the chip, the spiral channel has a proximal end and a distal end, the proximal end communicates with the sample chamber, and the distal end communicates with the waste pool. The metering chambers are distributed on the outside of the helical channel along the helical channel and communicate with the helical channel, and a micro-valve is connected to the outside of each metering chamber;

Add the liquid to the sample chamber, use the rotating device to rotate the chip, the sample moves along the spiral channel, enter the metering chamber, adjust the rotation speed of the chip, make the sample into the sample chamber, adjust the rotation rate of the chip, make the sample enter the spiral channel, and then under the centrifugal force Under the action of , the sample enters 10 measuring chambers respectively. At this time, the capillary microvalve is closed, and the sample cannot flow out from the measuring chamber, so the measuring chamber will be filled instantly, and the excess sample will enter the waste liquid chamber; increase the chip speed , so that the samples enter 10 mixing chambers respectively. The resistance of the microvalve and the size of the metering chamber are pre-set. The microvalve controls the sequence of the sample entering the mixing chamber, and the size of the metering chamber controls the volume of the sample entering the mixing chamber, which can realize different proportions between samples.

Since air will remain in the chip structure, and the inner diameter of the spiral channel is very small, ventilation holes need to be designed. The position and number of ventilation holes can be adjusted according to the specific application experiment scene.

Figure 3 shows a microfluidic chip according to the present invention. The chip body is provided with two spiral channels, and the corresponding sample chamber, spiral channel, waste liquid chamber, metering chamber, microvalve, microfluidic channel and liquid mixing chamber. . It can realize automatic injection of 2 kinds of samples and control of specific concentration. The specific operation process is as follows. Two samples (sample A and sample B) are firstly added to the two sample chambers (for the convenience of description, the spiral channel with sample A is called spiral channel A, and the spiral channel with sample B is called as spiral channel A). Spiral channel B), adjust the rotation speed of the microfluidic control chip, so that sample A and sample B enter the corresponding spiral channel respectively, and then under the action of centrifugal force, the two samples enter the metering chamber outside the corresponding spiral channel respectively. When the capillary microvalve of the spiral channel is closed, the sample cannot flow out of the metering chamber, so the metering chamber will be filled instantly, and the excess sample will enter the waste liquid chamber. Compared with the microvalve of the inner spiral channel, the microvalve of the outer spiral channel is farther from the center of the chip, so it is subjected to a greater centrifugal force and will open before the microvalve of the inner spiral channel. Increase the rotation speed of the microfluidic chip, so that the microvalve of the outer spiral channel is open and the microvalve of the inner spiral channel is closed, then the sample in the metering chamber of the outer spiral channel will enter the mixing chamber through the microvalve through the microfluidic channel; Continue to increase the motor speed, so that the microvalve of the inner spiral channel opens, the sample in the metering chamber of the inner spiral channel will pass through the microvalve, and under the action of centrifugal force, it will instantly pass through the metering chamber, microvalve, and microcirculation of the outer spiral channel. into the mixing chamber. In this process, the microvalve controls the order of the samples entering the mixing chamber, and the size of the metering chamber controls the volume of the samples entering the mixing chamber, which can realize different proportions of samples.

Table 1 Set 2 spiral channels on the microfluidic chip body to achieve 10 ratios of 2 liquids

Volume of 10 metering chambers on spiral channel A (microliters) 6 7 8 9 10 1 2 3 4 5 Volume of 10 metering chambers on spiral channel B (microliters) 15 13 11 17 19 16 11 13 14 8 A:B (volume ratio) of the mixture in the mixing chamber 6/15 7/13 8/11 9/17 10/19 1/6 2/11 3/13 4/14 5/8

In addition, other operation schemes can be adopted, such as placing the liquid in the sample chamber at the same time, and by changing the structure of the sample chamber and the contact angle with the helical channel, the purpose of selecting samples in different sample chambers to enter the helical channel at different speeds is achieved. Due to the centrifugal force that the liquid is always subjected to during the rotation process, it is only necessary to adjust the speed according to the type and requirements of the applicable liquid, the design of the size of the measuring chamber, the size of the micro-valve and the size of the structural channel, the number of the measuring chamber and the mixing chamber. The adjustment of the two samples can realize the automatic injection of the two samples and the stepwise change of the solution concentration.

4 is a microfluidic chip of the present invention. Three spiral channels are arranged on the chip body, and corresponding sample chambers, spiral channels, waste liquid chambers, metering chambers, microvalves, microfluidic channels and liquid mixing chambers. It can realize automatic injection of 3 kinds of samples and control of specific concentrations. The specific operation process is as follows, put two samples (sample A, sample B, sample C) into three sample chambers (for the convenience of description, here the spiral channel adding sample A is called spiral channel A, and the spiral channel adding sample B is The spiral channel is called spiral channel B, and the spiral channel with sample C is called spiral channel C). Adjust the rotation speed of the microfluidic chip so that sample A, sample B and sample C enter the corresponding spiral channel respectively, and then under the action of centrifugal force, the three samples enter the measurement chamber outside the corresponding spiral channel. The capillary microvalve of the spiral channel is closed, and the sample cannot flow out of the metering chamber, so the metering chamber will be filled instantly, and the excess sample will enter the waste liquid chamber. Compared with the microvalves of the inner spiral channels, the microvalves of the outer spiral channels are farther from the center of the chip, so they are subjected to greater centrifugal force and will open before the microvalves of the inner spiral channels. Increase the rotation speed of the microfluidic chip so that the microvalve of the outermost spiral channel is in an open state, and the microvalves of all the inner spiral channels are in a closed state, then the sample in the metering chamber of the outermost spiral channel will pass through the microfluidic channel through the microvalve. Enter the mixing chamber; continue to increase the motor speed, so that the micro-valve of the inner spiral channel is opened in turn, the sample in the metering chamber of the inner spiral channel will pass through the micro-valve, and under the action of centrifugal force, it will pass through the relative outer spiral channel. chamber, microvalve, enter the metering chamber of the spiral channel on the opposite side, and finally enter the mixing chamber through the microfluidic channel. In this process, the microvalve controls the order of the samples entering the mixing chamber, and the size of the metering chamber controls the volume of the samples entering the mixing chamber, which can realize different proportions of samples.

Table 2 Set 3 spiral channels on the microfluidic chip body to achieve 9 kinds of ratios of 3 kinds of liquids

Volume of 9 metering chambers on spiral channel A (microliters) 6 7 8 9 10 1 2 3 4 Volume of 9 metering chambers on spiral channel B (microliters) 8 10 9 13 15 7 9 8 13 Volume of 9 metering chambers on spiral channel C (microliters) 11 14 12 13 17 7 11 13 17 A:B:C (volume ratio) of the mixture in the mixing chamber 6/8/11 7/10/14 8/9/12 9/13/13 10/15/17 1/7/7 2/9/11 3/8/13 4/13/17

Figure 5 is a microfluidic chip of the present invention, the chip body is provided with 4 spiral channels, and the corresponding sample chamber, spiral channel, waste liquid chamber, metering chamber, microvalve, microfluidic channel and liquid mixing chamber. It can realize automatic injection of 4 kinds of samples and control of specific concentrations. The specific operation process is as follows, put two kinds of samples (sample A, sample B, sample C, sample D) into 4 sample chambers (for the convenience of description, the spiral channel for adding sample A is called spiral channel A, The spiral channel of sample B is called spiral channel B, the spiral channel of sample C is called spiral channel C, and the spiral channel of sample D is called spiral channel D). Adjust the rotation speed of the microfluidic chip so that sample A, sample B, sample C and sample D enter the corresponding spiral channel respectively, and then under the action of centrifugal force, the four samples enter the metering chamber outside the corresponding spiral channel, respectively. At this time, the capillary microvalve of the spiral channel is closed, and the sample cannot flow out of the metering chamber, so the metering chamber will be filled instantly, and the excess sample will enter the waste liquid chamber. Compared with the microvalve of the inner spiral channel, the microvalve of the relatively outer spiral channel is farther from the center of the chip, so the centrifugal force is greater, and the microvalve of the inner spiral channel will be opened before the microvalve of the inner spiral channel. Increase the rotation speed of the microfluidic chip, so that the microvalve of the outermost spiral channel is open, and the microvalves of all the inner spiral channels are closed, then the sample in the metering chamber of the outermost spiral channel will pass through the microvalve through the microfluidic channel. Enter the mixing chamber; continue to increase the motor speed, so that the micro-valve of the inner spiral channel is opened in turn, and the sample in the metering chamber of the inner spiral channel will pass through the micro-valve in turn, and under the action of centrifugal force, it will pass the measurement of the relative outer spiral channel. chamber, microvalve, enter the metering chamber of the spiral channel on the opposite side, and finally enter the mixing chamber through the microfluidic channel. In this process, the microvalve controls the order of the samples entering the mixing chamber, and the size of the metering chamber controls the volume of the samples entering the mixing chamber, which can realize different proportions of samples.

Table 3 Set 4 spiral channels on the microfluidic chip body to realize 9 kinds of ratios of 4 kinds of liquids

The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be considered that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field of the present invention, without departing from the concept of the present invention, some simple deductions or substitutions can be made, which should be regarded as belonging to the protection scope of the present invention.

Claims (6)

1. A microfluidic chip, characterized in that: comprises a chip body (1), a spiral channel (4), a sample chamber (2), a waste liquid chamber (8), a metering chamber (3), a micro valve (5), a micro flow channel (6) and a liquid mixing chamber (7); regard as the reference with the same radius line from the directional edge in chip body (1) center, will be relatively close to the position at chip body (1) center and be called nearly heart side, keep away from the position at chip body (1) center relatively and be called far away the heart side, set up n spiral channel on chip body (1), n is more than or equal to 2's integer, n spiral channel interval distribution in proper order on chip body (1), every spiral channel (4) is from being close to chip body (1) central point and beginning, the spiral extends to and is close to chip body (1) border point and ends, the initiating terminal is provided with sample room (2), the termination end is provided with waste liquid room (8), along spiral channel (4) outer fringe interval overall arrangement have metering chamber (3), metering chamber (3) nearly heart side communicates with each other with spiral channel (4), metering chamber (3) far away heart side is connected with microvalve (5), microvalve (5) open in its spiral channel (4) of far away heart side, a microvalve (5) and a microfluidic channel (6) are sequentially arranged on the telecentric side of the metering chamber (3) of the outermost spiral channel (4), and a liquid mixing chamber (7) is arranged on the telecentric side of the microfluidic channel (6); the threshold value of each micro valve (5) from the far center side to the near center side is gradually increased, so that when the rotation rate of the microfluidic chip is increased, the micro valve (5) at the far center side is opened before the micro valve (5) at the near center side; the volume of the metering chamber (3) is set according to requirements so as to realize the mixing of different liquids in the liquid mixing chamber (7) in required proportion.

2. The microfluidic chip according to claim 1, wherein the trajectory (X, Y) parameter equation of the spiral channel is:

Xt＝r+R*t/2*π*cos(t)

Yt＝r+R*t/2*π*sin(t)

t is the angle between the connecting line of the point on the spiral channel and the center of the chip and the X axis, R is the distance between the starting point of the spiral channel and the center of the chip, and (R + R) is the distance between the ending point of the spiral channel and the center of the chip.

3. Microfluidic chip according to claim 1 or 2, wherein the number n of spiral channels (4) can be increased to the maximum, which is not increased due to the chip body (1) of the microfluidic chip.

4. The microfluidic chip according to claim 1 or 2, wherein the spiral channel (4), the sample chamber (2) and the waste liquid chamber (8) are further provided with vent holes (10).

5. Microfluidic chip according to claim 1 or 2, characterized in that the chip body (1) is circular.

6. A method for realizing automatic feeding and quantitative mixing of n liquids by using the microfluidic chip as claimed in any one of claims 1 to 5 and detecting the mixture by means of a detection device, comprising the following steps:

(1) respectively adding liquid to be mixed into a sample chamber (2) of the micro-fluidic chip with n spiral channels;

(2) placing the micro-fluidic chip on a rotating platform, rotating the micro-fluidic chip, allowing liquid to enter a spiral channel (4), filling a plurality of metering chambers (3) located on the telecentric side of the spiral channel (4) in sequence, and allowing redundant liquid to enter a waste liquid chamber (8) located at the terminating end of the spiral channel (4);

(3) gradually increasing the rotation rate of the microfluidic chip to enable the liquid in the metering chamber (3) to enter the liquid mixing chamber (7) in sequence from outside to inside, wherein the liquid in the metering chamber (3) of the farthest heart side spiral channel (4) is the first liquid and the liquid in the metering chamber (3) of the nearest heart side spiral channel (4) is the last liquid, and the redundant liquid enters the waste liquid chamber (8);

(4) and mixing and reacting the liquids in the liquid mixing chamber (7), and detecting the liquids in the liquid mixing chamber (7) by using a detection device.

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