CN220143418U - Microfluidic chip - Google Patents

Abstract

The utility model relates to a microfluidic chip, which comprises a functional plate with a first side surface and a second side surface which are oppositely arranged, and also comprises a first functional flow channel, a second functional flow channel and a sorting flow channel, wherein the first functional flow channel is arranged on the first side surface and comprises an inlet and an outlet, the inlet is used for feeding liquid, and the first functional flow channel is used for respectively gathering white blood cells and circulating tumor cells in a sample into strips; the second functional flow channel is arranged on the second side surface and is communicated with the area between the inlet and the outlet on the first functional flow channel, and the second functional flow channel is used for collecting leucocytes in the integrated belt; the sorting flow channel is arranged on the first side surface and communicated with the outlet, the sorting flow channel comprises a plurality of branch flow channels, two adjacent branch flow channels are arranged at an included angle, and the sorting flow channel is used for sorting the sorting sample flowing out from the outlet again so as to lead different cells to be shunted into the corresponding branch flow channels.

Description

Microfluidic chip

Technical Field

The utility model relates to the technical field of cell sorting, in particular to a microfluidic chip.

Background

Circulating tumor refers to tumor cells which are taken off from primary tumor into body fluid and participate in vivo circulation, and circulating tumor cell detection (CTC) is carried out periodically, so that early detection and early treatment of cancers are facilitated, and the worsening of the disease is avoided. The circulating tumor cells need to be sorted from the body fluid for use before testing can be performed. In the prior art, a microfluidic chip is often used to separate out circulating tumor cells in body fluid, for example, in the patent application with application number of cn202110130174.X, the microfluidic chip includes a removal flow channel 50 and a buffer flow channel 90, the removal flow channel 50 is used to collect white blood cells and circulating tumor cells in a sample into strips, the buffer flow channel 90 is used to collect white blood cells in the strips, and body fluid enters the microfluidic chip from an inlet, flows into the removal flow channel 50 first, and flows into the buffer flow channel 90 through the removal flow channel 50.

However, the body fluid is easy to shake when flowing into the removing flow channel 50, which affects the collection of tumor cells in the subsequent circulation, and a longer flow channel with buffer function needs to be arranged before the body fluid enters the removing flow channel 50, so that the movement of biological particles is prevented from being disturbed. However, the length of the flow channel for buffering is long, and the size of the microfluidic chip needs to be increased to meet the size requirement of the flow channel.

Disclosure of Invention

Based on this, it is necessary to provide a microfluidic chip for avoiding the problem that the size of the microfluidic chip increases due to the turbulence of the movement of the biological particles by providing a long flow channel having a buffer function.

A microfluidic chip comprising a functional plate having oppositely disposed first and second sides, the microfluidic chip further comprising:

the first functional flow channel is arranged on the first side surface and comprises an inlet and an outlet, the inlet is used for feeding liquid, and the first functional flow channel is used for respectively aggregating white blood cells and circulating tumor cells in a sample into bands;

the second functional flow channel is arranged on the second side surface and is communicated with the area between the inlet and the outlet on the first functional flow channel, and the second functional flow channel is used for collecting the leucocytes in the integrated belt;

the sorting flow channel is arranged on the first side face and communicated with the outlet, the sorting flow channel comprises a plurality of branch flow channels, two adjacent branch flow channels are arranged at an included angle, and the sorting flow channel is used for sorting the sorting sample flowing out from the outlet again so as to enable different cells to be shunted into the corresponding branch flow channels.

In one embodiment, the first functional flow passage includes a plurality of planar flow passages and barrier flow passages alternately arranged and communicated with each other, and a diversion hole for communicating with the second functional flow passage is provided in the barrier flow passage.

In one embodiment, a blocking member for blocking the focusing band of the circulating tumor cells is arranged at the entrance of the barrier flow channel corresponding to the flow dividing hole, and the blocking member is positioned at one side of the flow dividing hole away from the second functional flow channel.

In one embodiment, the blocking member protrudes from the wall surface of the barrier flow channel, one side of the blocking member, which faces away from the second functional flow channel, is an arc-shaped wall, and the bending direction of the arc-shaped wall is consistent with the bending direction of the inner wall surface of one side of the barrier flow channel, which is close to the blocking member.

In one embodiment, the distance between the arc-shaped wall of the barrier and the inner wall surface of the barrier on the side close to the barrier is an obstacle distance, and the obstacle distance in the previous barrier is larger than the obstacle distance in the next barrier in the flow direction of the sample.

In one embodiment, the second functional flow channels include a plurality of flow sections which are sequentially communicated, the flow directions of any two adjacent flow sections are opposite, and the second functional flow channels are communicated with the plurality of flow dividing holes in a one-to-one correspondence manner.

In one embodiment, the volume of the last functional channel is smaller than the volume of the next functional channel along the flow direction of the sample.

In one embodiment, the sorting flow channel is Y-shaped, and the sorting flow channel includes two branched flow channels.

In one embodiment, the device further comprises a monotonic flow channel arranged on the first side surface, the monotonic flow channel is in a flaring shape, the monotonic flow channel comprises a large end and a small end, the large end is communicated with the inlet, and the small end is used for feeding liquid.

In one embodiment, the device further comprises a transition runner arranged on the first side face, the transition runner comprises a plurality of transition units which are communicated in sequence, the transition units are U-shaped, and the transition units are communicated with the small end.

The utility model has the beneficial effects that:

according to the microfluidic chip, the first functional flow channel and the sorting flow channel are arranged on the first side face of the functional plate, the second functional flow channel communicated with the first functional flow channel is arranged on the second side face, the first functional flow channel comprises the inlet and the outlet, a sample flows into the first functional flow channel through the inlet and then flows into the first functional flow channel, so that white blood cells and circulating tumor cells are respectively gathered into strips, because the second functional flow channel is communicated with the first functional flow channel, part of white blood cells gathered into strips can flow into the second functional flow channel through the first functional flow channel, so that white blood cells and circulating tumor cells are sorted, then the sorting flow channel communicated with the first functional flow channel is arranged at the outlet of the first functional flow channel, and different cells in the sample flowing out through the outlet of the first functional flow channel are shunted into the corresponding flow channels, so that the sorting flow channel can sort the sample flowing out through the outlet. According to the microfluidic chip provided by the utility model, the leucocytes and the circulating tumor cells are respectively gathered into the bands through the first functional flow channel, and then the leucocytes are collected through the second functional flow channel, so that the leucocytes and the circulating tumor cells are sorted, and the sorting flow channel is further arranged to sort the cells in the sorted sample flowing out through the outlet, so that the sorting effect is improved.

Drawings

Fig. 1 is a schematic structural diagram of a microfluidic chip according to an embodiment of the present utility model;

FIG. 2 is a schematic diagram of a communication structure between a first functional flow channel and a second functional flow channel according to an embodiment of the present utility model;

FIG. 3 is a schematic structural diagram of a first functional flow channel according to an embodiment of the present utility model;

FIG. 4 is a schematic view of a first view of an obstacle flow channel according to an embodiment of the present utility model;

fig. 5 is a schematic structural diagram of a second view of an obstacle flow channel according to an embodiment of the utility model.

In the figure:

100. a function board; 110. a first side;

200. a first functional flow path; 210. a planar flow channel; 220. obstacle flow path; 221. a diversion aperture; 222. a blocking member;

300. a second functional flow path;

400. sorting flow channels; 410. branching flow channels;

500. a monotonic flow path;

600. and a transition flow passage.

Detailed Description

In order that the above objects, features and advantages of the utility model will be readily understood, a more particular description of the utility model will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present utility model. The present utility model may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the utility model, whereby the utility model is not limited to the specific embodiments disclosed below.

In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present utility model.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present utility model, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

The embodiment of the utility model provides a microfluidic chip, as shown in fig. 1, the microfluidic chip comprises a functional board 100 with a first side 110 and a second side which are oppositely arranged, the microfluidic chip further comprises a first functional flow channel 200, a second functional flow channel 300 and a sorting flow channel 400, the first functional flow channel 200 is arranged on the first side 110, the first functional flow channel 200 comprises an inlet and an outlet, the inlet is used for feeding liquid, and the first functional flow channel 200 is used for respectively gathering white blood cells and circulating tumor cells in a sample into bands; the second functional flow channel 300 is arranged on the second side surface and is communicated with the area between the inlet and the outlet on the first functional flow channel 200, and the second functional flow channel 300 is used for collecting leucocytes in the integrated belt; the sorting flow channel 400 is disposed on the first side 110 and is communicated with the outlet, the sorting flow channel 400 includes a plurality of branch flow channels 410, and two adjacent branch flow channels 410 are disposed at an included angle, and the sorting flow channel 400 is used for sorting the sorted sample flowing out from the outlet again, so that different cells are shunted into the corresponding branch flow channels 410.

In the microfluidic chip, the first functional flow channel 200 and the sorting flow channel 400 are provided on the first side 110 of the functional plate 100, the second functional flow channel 300 communicating with the first functional flow channel 200 is provided on the second side, the first functional flow channel 200 includes an inlet and an outlet, the sample flows into the first functional flow channel 200 through the inlet and then flows in the first functional flow channel 200, so that the white blood cells and the circulating tumor cells are respectively collected into bands, because the second functional flow channel 300 communicates with the first functional flow channel 200, part of the white blood cells collected into bands can flow into the second functional flow channel 300 through the first functional flow channel 200, so that the white blood cells and the circulating tumor cells are sorted, and then the sorting flow channel 400 communicating with the first functional flow channel 200 is provided on the outlet, and different cells in the sample flowing out through the outlet of the first functional flow channel 200 are shunted into the corresponding flow channels, so that the sorting flow channel 400 can sort the sample flowing out through the outlet. According to the microfluidic chip provided by the utility model, the white blood cells and the circulating tumor cells are respectively gathered into strips through the first functional flow channel 200, and then the white blood cells are collected through the second functional flow channel 300, so that the white blood cells and the circulating tumor cells are sorted, and the sorting flow channel 400 is further arranged to sort the cells in the sorted sample flowing out through the outlet, so that the sorting effect is improved.

As shown in fig. 1, in some embodiments, the sorting channel 400 has a Y-shape, and the sorting channel 400 includes two branched channels 410. Because of the difference in cell diameter, nuclear to cytoplasmic ratio and cell deformability of the cells in the sorted sample, each particle will flow in focus at a different location within the first functional flow channel 200, and when the sorted sample flows out into the sorting flow channel 400 through the outlet of the first functional flow channel 200, different particles will split into different branch flow channels 410. Providing two branch flow channels 410 to sort the sorted samples again improves sorting accuracy.

In some embodiments, the number of the branch flow passages 410 may be three, four or even more, and the number of the branch flow passages 410 is not limited herein, and the specific number is set according to experimental needs.

Specifically, as shown in fig. 1, the microfluidic chip further includes a monotonic flow channel 500 disposed on the first side 110, the monotonic flow channel 500 is in a flared shape, the monotonic flow channel 500 includes a large end and a small end, the large end is communicated with the inlet, and the small end is used for liquid intake. The monotonic flow channel 500 is provided at the inlet end of the first functional flow channel 200 in a flared shape, and a sample can enter the first functional flow channel 200 through the small end of the monotonic flow channel 500 and the large end of the monotonic flow channel 500 in sequence. The monotone runner 500 is arranged to prevent the original biological particle movement from being disturbed after the smaller runner suddenly enters the wide runner, thereby playing the most basic role of buffering. Such a design also avoids the need for a longer flow path to focus the particles into a band and the chip size is controlled.

Specifically, as shown in fig. 1, the microfluidic chip further includes a transition flow channel 600 disposed on the first side 110, where the transition flow channel 600 includes a plurality of sequentially communicated transition units, the transition units are in a U-shape, and the transition units are communicated with the small end. The transition unit is U-shaped, so that the buffer effect and the effect of aggregating circulating tumor cells can be achieved.

More specifically, as shown in fig. 1, the transition flow channel 600 is disposed in the first row, and the first functional flow channel 200 and the sorting flow channel 400 are disposed in the second row, and since the transition flow channel 600 and the first functional flow channel 200 are connected by the monotonic flow channel 500, it is necessary to arrange the monotonic flow channel 500 in an arc-shaped structure, and when passing through the monotonic flow channel 500, the centrifugal force to which the sample in the middle of the flow channel is subjected is maximized, thereby flowing to the outer edge of the channel. The flow velocity of the fluid near the channel walls of the monotonic flow channel 500 is minimal and the centrifugal force experienced is minimal, thereby being compressed by the intermediate fluid. Thus, under the action of the monotone flow channel 500, the circulating tumor cells can be greatly close to the bottom of the inner wall of the monotone flow channel 500, so as to prepare for the subsequent separation of the circulating tumor cells and the removal of the white blood cells through the first functional flow channel 200.

Further, as shown in fig. 2 to 4, the first functional flow passage 200 includes a plurality of planar flow passages 210 and barrier flow passages 220 alternately arranged and communicated with each other, and a flow dividing hole 221 for communicating with the second functional flow passage 300 is provided in the barrier flow passage 220. When a sample (such as blood) is poured into the first functional flow channel 200 for cell sorting, the sample passes through the plane flow channel 210 and the barrier flow channel 220 with asymmetric curved surfaces, and white blood cells and circulating tumor cells in the blood relatively move in the first functional flow channel 200 due to the main effects of inertia lifting force and dean drag force, and after the particles are stressed uniformly, the particles are stabilized at a certain cross-section position in the first functional flow channel 200, so that a strip motion of focused flow is formed, and the strip motion moves downstream along with liquid flow. Because of the difference in cell diameter, nuclear mass ratio and cell deformability of the individual particles, such as white blood cells and circulating tumor cells in blood, the individual particles will flow in focus at different positions in the flow channel, but because of the similar diameters of some particles, such as tumor cells and white blood cells in blood, the focus flow positions formed in the flow channel are close, so that the planar flow channel 210 and the barrier flow channel 220 are alternately arranged, the planar flow channel 210 can smoothly pass through the flow channel for the individual particles, such as tumor cells in a blood sample, and the barrier flow channel 220 enables the focus band of the individual particles, such as white blood cells in the blood sample, in the flow channel to be disturbed, so that the inertial lift force and dean drag force are changed, and the original balance is destroyed, so that the white blood cells flow into the second functional flow channel 300 through the separation hole 221.

Specifically, as shown in fig. 2 to 4, a blocking member 222 for blocking the focusing band of circulating tumor cells is provided at the entrance of the corresponding diverting hole 221 in the blocking flow channel 220, and the blocking member 222 is located at the side of the diverting hole 221 facing away from the second functional flow channel 300. The blocking member 222 can block the focused circulating tumor cells from flowing into the diversion hole 221, the circulating tumor cells flow downstream of the first functional flow passage 200 along the blocking member 222, white blood cells are uniformly distributed in the first functional flow passage 200, and part of white blood cells flow out of the first functional flow passage 200 from the diversion hole 221. The blocking piece 222 is arranged to block the circulating tumor cells when the diversion holes 221 are used for discharging, so that the circulating tumor cells are prevented from flowing into the diversion holes 221, the content proportion of the circulating tumor cells in the liquid at the downstream of the diversion holes 221 is increased, and the recovery rate of the circulating tumor cells can be further effectively improved.

Specifically, as shown in fig. 2 to 4, the blocking member 222 is disposed protruding from the wall surface of the barrier flow channel 220, the side of the blocking member 222 facing away from the second functional flow channel 300 is an arc-shaped wall, and the bending direction of the arc-shaped wall coincides with the bending direction of the inner wall surface of the barrier flow channel 220 on the side close to the blocking member 222. The upper wall surface of the blocking member 222 is provided with an arc-shaped wall, namely, the side, close to the circulating tumor cell aggregation, of the blocking member 222 is provided with an arc-shaped wall, so that the blocking member is matched with the circulating tumor cell aggregation belt. The inner top surface of the obstruction runner 220 is provided with an arc-shaped wall, and the curved square shape of the upper wall surface is consistent with that of the inner top surface, so that the influence of the blocking piece 222 on the circulating tumor cell aggregate is consistent, and the disturbance of the circulating tumor cell focusing band is avoided.

It should be noted that, when the sample such as blood is flushed into the first functional flow channel 200 to perform cell sorting, the small-amplitude semi-arc-shaped blocking member 222 also has an effect of scattering cells near the dispensing hole 221 when passing through the barrier flow channel 220.

Specifically, as shown in fig. 4 and 5, the stopper 222 and the function plate 100 are integrally provided. The first functional flow channel 200 is disposed on the first side 110, and the blocking member 222 is formed by a protruding portion reserved in the opening process of the first functional flow channel 200. The blocking member 222 is disposed about the periphery of the side of the arcuate wall opposite the flow aperture 221 in a portion thereof. The white blood cells flowing toward the diverting hole 221 are blocked by the blocking member 222 away from the sidewall of the arc wall, and finally flow into the diverting hole 221.

It should be noted that, as shown in fig. 4 and fig. 5, in some embodiments, the flow channel profiles of the planar flow channel 210 and the barrier flow channel 220 may be the same, and both the flow channel profiles of the planar flow channel 210 and the barrier flow channel 220 are the same, so as to facilitate processing; the planar flow path 210 is different from the barrier flow path 220 in that a diversion hole 221 and a barrier 222 are provided on the barrier flow path 220. In some embodiments, the flow channel profiles of the planar flow channel 210 and the obstruction flow channel 220 may be different, and the specific flow channel profile may be processed according to actual operation requirements.

Specifically, referring back to fig. 3, the distance between the arc-shaped wall of the barrier 222 and the inner wall surface of the barrier flow channel 220 on the side close to the barrier 222 is the barrier distance, and the barrier distance in the previous barrier flow channel 220 is larger than the barrier distance in the next barrier flow channel 220 in the flow direction of the sample. The distance between the arc-shaped wall of the barrier 222 and the inner wall surface of the barrier flow channel 220 on the side close to the barrier 222 is the barrier distance, that is, the distance between the upper wall surface of the barrier 222 and the inner top surface of the barrier flow channel 220 is the barrier distance D, the value of the barrier distance D in the previous barrier flow channel 220 is larger than the value of the barrier distance D in the next barrier flow channel 220 along the flow direction of the sample, the sample flows along the flow direction, the inertial focusing flow band is disturbed by the barrier flow channel 220, the circulating tumor cells in the target particles such as blood samples can also generate a certain scattering state due to the tiny change of the internal force, the inertial focusing flow band in the flow is influenced, and the positions of the upper wall surface of the barrier 222 and the inner top surface of the barrier flow channel 220 can be prevented from losing the target particles and removing non-target particles such as white blood cells in the blood along with the decrease of the liquid flow direction distance.

In some embodiments, as shown in fig. 1-3, the first functional flow channel 200 includes four planar flow channels 210 and four barrier flow channels 220, and the barrier flow channels 220 are in communication with the monotonic flow channel 500, and the sample flows from right to left (right to left as shown in fig. 3) as it flows from the monotonic flow channel 500 into the first functional flow channel 200. Along the flow direction of the sample, the first inter-obstacle distance D1 > the second inter-obstacle distance D2 > the third inter-obstacle distance D3 > the fourth inter-obstacle distance D4.

In some embodiments, the first functional flow channel 200 includes four planar flow channels 210 and four barrier flow channels 220, and the barrier flow channels 220 are in communication with the monotonic flow channel 500, from right to left (right to left as shown in fig. 3) as the sample flows from the monotonic flow channel 500 into the first functional flow channel 200. The last obstacle pitch and the last obstacle pitch may be equal, for example, in the flow direction of the sample, the first obstacle pitch D1 > the second obstacle pitch D2 > the third obstacle pitch d3=the fourth obstacle pitch D4.

Referring back to fig. 1 and 2, the second functional flow channels 300 include a plurality of flow sections that are sequentially communicated, the flow directions of any two adjacent flow sections are opposite, and the plurality of second functional flow channels 300 are in one-to-one correspondence communication with the plurality of diversion holes 221. The second functional flow channel 300 is provided with a plurality of flow channel sections, one end of the flow section is communicated with the diversion holes 221 in a one-to-one correspondence manner, the other end of the flow section is communicated with air, and when a sample passes through the junction of the barrier flow channel 220 and the second functional flow channel 300, as the other end of the flow section of the second functional flow channel 300 is connected with the outside air, when the sample such as blood stably runs in the flow channel, the external liquid pressure difference influences the liquid outflow proportion in the pipeline, so that the leucocytes can flow out through the flow channel sections.

Specifically, as shown in fig. 1 and 2, the volume of the previous second functional flow channel 300 is smaller than the volume of the next second functional flow channel 300 in the flow direction of the sample. When the sample enters the first functional flow channel 200 from the monotonic flow channel 500 along the direction of the sample flow, the nuclei and the small cells in the sample are unevenly stressed due to the generation of internal vortex, which is more easily confused. In this case, the large cells such as tumor cells to be sorted are also affected, so that, for conservation, the volume of the second functional flow channel 300 gradually increases along the flow direction of the sample, that is, the volume of the previous second functional flow channel 300 is smaller than the volume of the next second functional flow channel 300, so that the internal pressure of the second functional flow channel 300 can be reduced to change the stress of the whole sample, and the circulating tumor cells are prevented from flowing into the second functional flow channel 300.

It should be noted that, although the volume of the plurality of second functional flow channels 300 is changed, such a change may result in a decrease in the effect of removing leukocytes, but may prevent the loss of target cells (i.e., circulating tumor cells). The increase in volume of the second functional flow path 300 in the direction of sample flow also changes the pressure in the second functional flow path 300, so that the liquid tends to flow out of the leukocyte removal channel more.

The change in volume of the second functional flow path 300 may be a change in width, depth, or length of the second functional flow path 300. If a fixed flow channel depth and width (the width generally being determined by the graver used) the volume can be varied by varying the length of the flow path (i.e., the pipe circumference) of the second functional flow channel 300.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the utility model. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.

Claims (9)

1. A microfluidic chip comprising a functional plate (100) having a first side (110) and a second side arranged opposite, characterized in that the microfluidic chip further comprises:

the first functional flow channel (200) is arranged on the first side surface (110), the first functional flow channel (200) comprises an inlet and an outlet, the inlet is used for feeding liquid, and the first functional flow channel (200) is used for respectively aggregating white blood cells and circulating tumor cells in a sample into bands;

a second functional flow channel (300) disposed on the second side surface and communicating with a region between the inlet and the outlet on the first functional flow channel (200), the second functional flow channel (300) being configured to collect the leucocytes in an integrated band;

the sorting flow channel (400) is arranged on the first side surface (110) and is communicated with the outlet, the sorting flow channel (400) comprises a plurality of branch flow channels (410), two adjacent branch flow channels (410) are arranged at an included angle, and the sorting flow channel (400) is used for sorting a sorting sample flowing out through the outlet again so as to lead different cells to be shunted into the corresponding branch flow channels (410);

the device further comprises a monotonic flow passage (500) arranged on the first side face (110), the monotonic flow passage (500) is in a flaring shape, the monotonic flow passage (500) comprises a large end and a small end, the large end is communicated with the inlet, and the small end is used for feeding liquid.

2. The microfluidic chip according to claim 1, wherein the first functional flow channel (200) comprises a plurality of planar flow channels (210) and barrier flow channels (220) alternately arranged and communicating with each other, and a flow dividing hole (221) for communicating with the second functional flow channel (300) is provided in the barrier flow channel (220).

3. The microfluidic chip according to claim 2, wherein a blocking member (222) for blocking a focusing band of circulating tumor cells is provided at an inlet of the barrier flow channel (220) corresponding to the flow dividing hole (221), and the blocking member (222) is located at a side of the flow dividing hole (221) facing away from the second functional flow channel (300).

4. A microfluidic chip according to claim 3, wherein the blocking member (222) protrudes from the wall surface of the barrier flow channel (220), the side of the blocking member (222) facing away from the second functional flow channel (300) is an arc-shaped wall, and the bending direction of the arc-shaped wall is consistent with the bending direction of the inner wall surface of the side of the barrier flow channel (220) close to the blocking member (222).

5. The microfluidic chip according to claim 4, wherein a distance between the arc-shaped wall of the barrier (222) and the inner wall surface of the barrier (220) on a side close to the barrier (222) is an obstacle distance, and a value of the obstacle distance in a previous one of the obstacle channels (220) is larger than a value of the obstacle distance in a next one of the obstacle channels (220) in a flow direction of the sample.

6. The microfluidic chip according to claim 2, wherein the second functional flow channels (300) comprise a plurality of sequentially communicated flow sections, the flow directions of any two adjacent flow sections are opposite, and the second functional flow channels (300) are communicated with the plurality of flow dividing holes (221) in a one-to-one correspondence.

7. The microfluidic chip according to claim 6, wherein the volume of the last one of the second functional channels (300) is smaller than the volume of the next one of the second functional channels (300) in the flow direction of the sample.

8. The microfluidic chip according to claim 1, wherein the sorting channel (400) has a Y-shape, and the sorting channel (400) comprises two of the branching channels (410).

9. The microfluidic chip according to claim 1, further comprising a transition flow channel (600) disposed on the first side (110), wherein the transition flow channel (600) comprises a plurality of sequentially communicated transition units, wherein the transition units are in a U-shape, and wherein the transition units are communicated with the small end.