Microfluidic chip, its operation method, and microfluidic device

Abstract

The present disclosure relates to a microfluidic chip, an operation method thereof, and a microfluidic device. The microfluidic chip includes a sample inlet, a sample injection channel, and a reaction channel. A liquid measurement cavity is connected between the sample injection channel and the reaction channel via a liquid bridge and is in communication with the atmosphere via a communication structure. The sample injection channel and the reaction channel each include a photo-deformable material, such that a microfluid can be driven through the corresponding channel under the action of a Laplace pressure difference generated by asymmetric photo-deformation of the corresponding channel. A preset microfluid is stored at a position separated from a second liquid bridge in the reaction channel. In this microfluidic chip, the cross-sectional area of the sample injection channel is greater than the cross-sectional area of the liquid measurement cavity, which is greater than the cross-sectional area of the reaction channel, which is greater than the cross-sectional area of the liquid bridge. The cross-sectional area of the communication structure on the side adjacent to the liquid measurement cavity is greater than or equal to the cross-sectional area of the sample injection channel, and the depth of the sample injection channel and the reaction channel is greater than the depth of the liquid bridge.

Description

Technical Field

[0001] The present disclosure relates to the field of microfluidic technology, and more particularly, to a microfluidic chip, an operation method thereof, and a microfluidic device. Background Art

[0002] Microfluidics can integrate complex microfluidic operations such as sample preparation, reaction, separation, and detection in the biological, chemical, and medical analysis processes onto a chip of more than a dozen square centimeters, so that the entire analysis process can be automatically completed, with advantages such as high integration and large throughput. In a microfluidic chip, if a trace sample (such as 10 microliters or less) can be accurately and quantitatively measured, the detection accuracy can be effectively improved, the sample loss can be reduced, and it is particularly beneficial for the accurate detection of trace samples. However, in a traditional microfluidic chip, in order to achieve accurate and quantitative measurement of a trace sample, complex fluid channels need to be designed, and pumps, valves, etc. also need to be provided to drive and control the fluid movement. Not only is the structure complex, the operation cumbersome, and it is difficult to achieve portability, but also because the fluid driven by the pump must be in a continuous state, the entire front channel needs to be filled to complete the subsequent measurement operation, so the sample loss is large. Therefore, currently, the microfluidic chip based on pump drive cannot achieve accurate and quantitative measurement of a truly trace sample. Summary of the Invention

[0003] A brief overview of the present disclosure is given below to provide a basic understanding of some aspects of the present disclosure. However, it should be understood that this overview is not an exhaustive overview of the present disclosure. It is not intended to identify the key or important parts of the present disclosure, nor is it intended to limit the scope of the present disclosure. Its purpose is only to present some concepts of the present disclosure in a simplified form as a prelude to the more detailed description given later.

[0004] According to a first aspect of the present disclosure, there is provided a microfluidic chip, comprising: a sampling inlet configured to receive a sample microfluid; a sampling channel configured to communicate with the sampling inlet to receive the sample microfluid from the sampling inlet, the sampling channel comprising a photo-deformable material such that the microfluid can be driven through the sampling channel under the action of the Laplace pressure difference generated by the asymmetric photo-deformation of the sampling channel; a liquid metering chamber configured to communicate with the sampling channel via a first liquid bridge to meter a preset volume of the sample microfluid from the sampling channel, and configured to communicate with the atmosphere via a communication structure; and a reaction channel configured to communicate with the liquid metering chamber via a second liquid bridge to receive the preset volume of the sample microfluid from the liquid metering chamber, and a preset microfluid is stored at a position separated from the second liquid bridge in the reaction channel, the reaction channel comprising a photo-deformable material such that the microfluid can be driven through the reaction channel under the action of the Laplace pressure difference generated by the asymmetric photo-deformation of the reaction channel, wherein the cross-sectional area of the sampling channel is greater than the cross-sectional area of the liquid metering chamber, the cross-sectional area of the liquid metering chamber is greater than the cross-sectional area of the reaction channel, the cross-sectional area of the reaction channel is greater than the cross-sectional area of the first liquid bridge and greater than the cross-sectional area of the second liquid bridge, the cross-sectional area of the communication structure on the side adjacent to the liquid metering chamber is greater than or equal to the cross-sectional area of the sampling channel, and wherein the depth of the sampling channel is greater than the depth of the first liquid bridge, and the depth of the reaction channel is greater than the depth of the second liquid bridge.

[0005] According to a second aspect of the present disclosure, there is provided a method for operating a microfluidic chip according to various embodiments of the first aspect of the present disclosure, the method comprising: adding a sample microfluid to the sampling inlet to cause the added sample microfluid to enter the sampling channel; driving the sample microfluid in the sampling channel to a first connection point of the first liquid bridge and the sampling channel by selectively illuminating a local part of the sampling channel, so that the sample microfluid enters the first liquid bridge and fills the first liquid bridge, the liquid metering chamber and the second liquid bridge; driving the sample microfluid remaining in the sampling channel away from the first connection point by selectively illuminating a local part of the sampling channel, so that the sample microfluid in the sampling channel is separated from the sample microfluid in the first liquid bridge; and after the sample microfluid in the sampling channel is separated from the sample microfluid in the first liquid bridge, driving the preset microfluid in the reaction channel to a second connection point of the second liquid bridge and the reaction channel by selectively illuminating a local part of the reaction channel, so that the preset microfluid in the reaction channel contacts the sample microfluid in the second liquid bridge, thereby causing the sample microfluid in the liquid metering chamber to enter the reaction channel and mix with the preset microfluid in the reaction channel to obtain a first mixed microfluid.

[0006] According to a third aspect of the present disclosure, there is provided a microfluidic device, which includes a microfluidic chip according to various embodiments of the first aspect of the present disclosure and a light source configured to provide light illumination to the microfluidic chip to control the movement of microfluid in the microfluidic chip.

[0007] Other features and advantages of the present disclosure will become clearer through the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings. Description of the Drawings

[0008] The drawings forming a part of the specification depict embodiments of the present disclosure and, together with the description, are used to explain the principles of the present disclosure. The embodiments set forth in the drawings are illustrative and exemplary in nature and are not intended to limit the present disclosure. The following detailed description of exemplary embodiments can be clearly understood when read in conjunction with the following drawings, where like structures are indicated by like reference numerals, and where:

[0009] Figures 1 to 4 and Figure 12 is a schematic diagram showing a microfluidic chip according to some embodiments of the present disclosure;

[0010] Figure 5 is a schematic diagram showing a non-limiting example process of optically driven microfluid in a microfluidic chip according to an embodiment of the present disclosure;

[0011] Figure 6 is a flowchart showing a method of operating a microfluidic chip according to some embodiments of the present disclosure;

[0012] Figures 7 to 11 is a schematic diagram showing a microfluidic device according to some embodiments of the present disclosure. Detailed Description of Specific Embodiments

[0013] The following will describe various exemplary embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be noted that: Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present disclosure.

[0014] The following description of at least one exemplary embodiment is merely illustrative in nature and in no way limits the present disclosure or its application or use. That is, the structures and methods herein are shown in an exemplary manner to illustrate different embodiments of the structures and methods in the present disclosure. However, those skilled in the art will understand that they merely illustrate exemplary ways in which the present disclosure can be implemented, rather than exhaustive ways. In addition, the drawings are not necessarily drawn to scale, and some features may be enlarged to show details of specific components.

[0015] In addition, technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorization specification.

[0016] In all examples shown and discussed herein, any specific values should be construed as merely exemplary and not as a limitation. Thus, other examples of the exemplary embodiments may have different values.

[0017] The present disclosure provides, in one aspect, a microfluidic chip that can drive a fluid by the Laplace pressure difference generated by the asymmetric photoinduced deformation of a fluid channel, thereby enabling non-contact quantitative measurement of a trace sample. Since the microfluidic chip according to the present disclosure does not require a pump to drive the fluid, the requirement for fluid continuity is low, the sample loss is low, and the number of components and the overall volume of the microfluidic chip and its supporting equipment are also small. The microfluidic chip according to the present disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the actual microfluidic chip may also include other components, but in order to avoid obscuring the key points of the present disclosure, these other components are not discussed herein and are not shown in the drawings.

[0018] Figure 1 A microfluidic chip 100 according to some embodiments of the present disclosure is shown. As Figure 1 shown, the microfluidic chip 100 includes a sample inlet 101, a sample injection channel 102, a liquid measurement chamber 103, and a reaction channel 106. The sample inlet 101 is configured to receive a sample microfluid. The sample injection channel 102 is configured to communicate with the sample inlet 101 to receive the sample microfluid from the sample inlet 101. For example, the sample microfluid can be dropped at the sample inlet 101 to fill the sample inlet 101 and then enter the sample injection channel 102 and extend a certain distance. Additionally, in this article, the cross-section refers to the plane where the width and depth are located, which is perpendicular to the direction of the length. The plane illustrated in Figures 1 to 4 is the plane where the width and length are located, but it should be noted that these figures are provided for illustrative purposes and are not necessarily drawn to scale. In some embodiments, the cross-sectional area of the sample inlet 101 can be greater than or equal to the cross-sectional area of the sample injection channel 102. This can facilitate the spontaneous entry of the sample microfluid from the sample inlet 101 into the sample injection channel 102.

[0019] The sample injection channel 102 includes a photoinduced deformation material, such that the microfluid can be driven (also referred to as photoinduced driving in this article) through the sample injection channel 102 under the action of the Laplace pressure difference generated by the asymmetric photoinduced deformation of the sample injection channel 102 (to be described in combination with Figure 5Describe in detail the process of optically driven microfluidics in this article). The metering chamber 103 is configured to communicate with the sampling channel 102 via the first liquid bridge 104 to meter a preset volume of sample microfluidics from the sampling channel 102, and is configured to communicate with the atmosphere via the communication structure 105 to facilitate the inflow of the sample microfluidics into the metering chamber 103. The reaction channel 106 is configured to communicate with the metering chamber 103 via the second liquid bridge 107 to receive the preset volume of sample microfluidics metered from the metering chamber 103, and a preset microfluidics (not shown in the figure) is stored at a position separated from the second liquid bridge 107 in the reaction channel 106. The preset microfluidics can be added to the reaction channel 106 (e.g., via a separate sampling port different from the sampling port 101 that is directly communicated with the reaction channel 106) during the usage stage of the microfluidic chip 100, or can also be added to the reaction channel 106 in advance during the manufacturing stage of the microfluidic chip 100. The reaction channel 106 also includes a photo-deformable material, such that the microfluidics can be driven through the reaction channel 106 under the Laplace pressure difference generated by the asymmetric photo-deformation of the reaction channel 106. For example, the preset microfluidics can be driven to the second connection point of the second liquid bridge 107 and the reaction channel 106 under the Laplace pressure difference generated by the asymmetric photo-deformation of the reaction channel 106 to contact and mix with the preset volume of sample microfluidics received from the metering chamber 103 in the reaction channel 106 to obtain the first mixed microfluidics.

[0020] In the microfluidic chip 100, the cross-sectional area of the sampling channel 102 is larger than the cross-sectional area of the metering chamber 103, and the cross-sectional area of the metering chamber 103 is larger than the cross-sectional area of the reaction channel 106. In this way, it is beneficial for the microfluidics to enter the metering chamber 103 from the sampling channel 102 and enter the reaction channel 106 from the metering chamber 103 under the action of the Laplace pressure difference. The cross-sectional area of the communication structure 105 on the side adjacent to the metering chamber 103 is larger than or equal to the cross-sectional area of the sampling channel 102. In this way, it can prevent the microfluidics from overflowing into the communication structure 105 or even leaking into the atmospheric environment after the metering chamber 103 is filled. The cross-sectional area of the reaction channel 106 is larger than the cross-sectional area of the first liquid bridge 104 and larger than the cross-sectional area of the second liquid bridge 107. Thus, the first liquid bridge 104 and the second liquid bridge 107 are the thinnest channels in the microfluidic chip 100, and their volumes can be configured to be negligible compared to the volume of the metering chamber 103. Therefore, the preset volume of the sampled microfluidics can be substantially equal to the volume of the metering chamber 103. It can be understood that even if the volumes of the first liquid bridge 104 and the second liquid bridge 107 are not so negligible compared to the volume of the metering chamber 103, it does not affect the quantitative metering of the microfluidic chip 100, except that the preset volume of the sampled microfluidics will be equal to the sum of the volumes of the metering chamber 103, the first liquid bridge 104, and the second liquid bridge 107.

[0021] In addition, in the microfluidic chip 100, the depth of the injection channel 102 is greater than the depth of the first liquid bridge 104, and the depth of the reaction channel 106 is greater than the depth of the second liquid bridge 107. Due to the depth differences between the first liquid bridge 104 and the injection channel 102 and between the second liquid bridge 107 and the reaction channel 106, steps are formed at the first connection point between the first liquid bridge 104 and the injection channel 102 and at the second connection point between the second liquid bridge 107 and the reaction channel 106. The step at the second connection point between the second liquid bridge 107 and the reaction channel 106 causes the sample microfluid to stop in the second liquid bridge 107 at the second connection point under the action of surface tension instead of flowing spontaneously into the reaction channel 106 after filling the metering chamber 103 and then filling the second liquid bridge 107, thereby acting as a brake on the sample microfluid and ensuring that the metering chamber 103 can accurately perform the metering operation. In some embodiments, the difference in depth between the first liquid bridge 104 and the injection channel 102 can be configured to allow the microfluid to move across the first connection point between the first liquid bridge 104 and the injection channel 102 in the injection channel 102, and the difference in depth between the second liquid bridge 107 and the reaction channel 106 can be configured to allow the microfluid to move across the second connection point between the second liquid bridge 107 and the reaction channel 106 in the reaction channel 106. Since the Laplace pressure difference generated by asymmetric photo-deformation can favorably overcome the flow resistance to drive the fluid only in a straight-through pipe with a small flow resistance, there needs to be a significant difference between the depth of the first liquid bridge 104 and the depth of the injection channel 102, and between the depth of the second liquid bridge 107 and the depth of the reaction channel 106. If the depth of the first liquid bridge 104 is close to the depth of the injection channel 102 and the depth of the second liquid bridge 107 is close to the depth of the reaction channel 106, then the pipe shape of the injection channel 102 at the first connection point between the first liquid bridge 104 and the injection channel 102 (close to a tee with a large flow resistance) changes significantly compared to the pipe shape of the injection channel 102 in the part other than the first connection point (straight-through pipe), and the pipe shape of the reaction channel 106 at the second connection point between the second liquid bridge 107 and the reaction channel 106 (close to a tee) changes significantly compared to the pipe shape of the reaction channel 106 in the part other than the second connection point (straight-through pipe), which will cause the photo-driven of the microfluid in the injection channel 102 and the reaction channel 106 to be hindered and it is difficult to freely move from one end across the first connection point and the second connection point to the other end in the injection channel 102 and the reaction channel 106. Further, in some examples, the ratio of the depth of the first liquid bridge 104 to the depth of the injection channel 102 is less than 1:2, and the ratio of the depth of the second liquid bridge 107 to the depth of the reaction channel 106 is less than 1:2. In some examples, the ratio of the depth of the first liquid bridge 104 to the depth of the injection channel 102 is less than or equal to 1:4, and the ratio of the depth of the second liquid bridge 107 to the depth of the reaction channel 106 is less than or equal to 1:4.When the ratio of the depth of the first liquid bridge 104 to the depth of the sample injection channel 102 and the ratio of the depth of the second liquid bridge 107 to the depth of the reaction channel 106 meet such requirements, it can effectively prevent the microfluid from spontaneously entering the reaction channel 106 after filling the metering chamber 103 and then filling the second liquid bridge 107, and can also reduce the influence of the first connection point between the first liquid bridge 104 and the sample injection channel 102 on the optically driven microfluid in the sample injection channel 102 and the influence of the second connection point between the second liquid bridge 107 and the reaction channel 106 on the optically driven microfluid in the reaction channel 106.

[0022] The dimensions of the depth and width of each channel included in the microfluidic chip 100 of this article can be, for example, in the order of magnitude of 10 - 10 3 micrometers. In some embodiments, the width and depth of each of the sample injection channel 102, the first liquid bridge 104, the metering chamber 103, the second liquid bridge 107, and the reaction channel 106 are respectively between 10 micrometers and 2000 micrometers, and can be, for example, between 50 micrometers and 1000 micrometers. When within such a range, the processing difficulty of the microfluidic chip 100 is moderate, and the performance of optically driven fluid is also better. In a non-limiting example, the width of the sample injection channel 102 can be 450 micrometers, the width of the metering chamber 103 can be 350 micrometers, the width of the reaction channel 106 can be 250 micrometers, the widths of the first liquid bridge 104 and the second liquid bridge 107 can be 200 micrometers, the depths of the sample injection channel 102, the metering chamber 103, and the reaction channel 106 can be 200 micrometers, the depths of the first liquid bridge 104 and the second liquid bridge 107 can be 50 micrometers, and the volume of the metering chamber 103 can be 400 nanoliters. Based on these dimensions, it can be determined that the influence of the fluid volume in the first liquid bridge 104 and the second liquid bridge 107 on the metering accuracy can be ignored.

[0023] Combined with reference Figure 1 and Figure 5, in some embodiments, the microfluidic chip 100 may include a substrate 10 having a sample inlet 101 and a groove communicating with the sample inlet 101, and a photo-deformable film 20 attached to the substrate 10. The photo-deformable film 20 at least partially covers the groove to form a closed channel 30 together with the groove, so that the microfluid can be driven through the closed channel 30 under the action of the Laplace pressure difference generated by the asymmetric photo-deformation of the closed channel 30. The closed channel 30 may include a sample inlet channel 102 and a reaction channel 106. For example, a groove can be machined on the substrate 10 as the bottom surface and side surface of the closed channel 30 by a high-precision Computerized Numerical Control (CNC) machine tool. After the CNC machining is completed, the photo-deformable film 20 is covered on the groove as the upper surface of the closed channel 30 to obtain a complete channel structure. In some embodiments, in order to reduce the difficulty of CNC machining and improve the measurement accuracy, the cross-sectional shape of the channel can be rectangular. However, this is merely exemplary and not restrictive, and the channel can also have other suitable cross-sectional shapes. In some examples, the substrate 10 can be an acrylic substrate, which can not only meet the requirements of the microfluidic chip for materials and the requirements of CNC machining for materials, but also has good transparency, which is more conducive to observing the state of the microfluid in the microfluidic chip. The photo-deformable material can be any suitable photo-deformable material known now or developed in the future. In some examples, the photo-deformable material may include a photo-deformable liquid crystal polymer material. For example, a whole film made of a photo-deformable liquid crystal polymer material can be used as the photo-deformable film 20. In some examples, the photo-deformable liquid crystal polymer material may include a photo-responsive linear liquid crystal polymer material with a main chain of polycyclooctene and a side chain containing azobenzene. In some embodiments, the substrate 10 and the photo-deformable film 20 can be recycled and reused. For example, an acrylic substrate that has been used but not damaged can be recycled as a brand-new component after thorough cleaning and drying to produce a new microfluidic chip, and the film made of a photo-deformable liquid crystal polymer material can also be processed by first dissolving and then extracting to obtain the original material and then re-prepared into a film for producing a new microfluidic chip.

[0024] When specific light conditions are met, a photo-deformable material (e.g., the photo-deformable film 20) can undergo local photo-deformation, resulting in a change in the cross-sectional area of a local channel. Under the action of the Laplace pressure difference, the fluid in the channel will move in the direction of decreasing cross-sectional area. In some embodiments, the photo-deformable material (e.g., the photo-deformable film 20) is configured to expand in response to being illuminated, such that portions of the sample injection channel 102 and the reaction channel 106 have a larger cross-sectional area when illuminated compared to when not illuminated, thereby driving the microfluidics in the sample injection channel 102 and the reaction channel 106 in the direction of decreasing light intensity. In some embodiments, the photo-deformable material (e.g., the photo-deformable film 20) is configured to contract in response to being illuminated, such that portions of the sample injection channel 102 and the reaction channel 106 have a smaller cross-sectional area when illuminated compared to when not illuminated, thereby driving the microfluidics in the sample injection channel 102 and the reaction channel 106 in the direction of increasing light intensity.

[0025] Reference Figure 5 , which shows the plane where the length and depth are located, and is illustrated by the non-limiting example of the photo-deformable film 20 expanding under light: The microfluidics 40 is at position a (represented by the position of the left end face of the microfluidics 40), and the cross-sectional areas of all parts of the closed channel 30 are initially the same; after irradiating the photo-deformable film 20 with light that can cause the expansion of the photo-deformable film 20 at position a, since the part of the photo-deformable film 20 at position a expands under light, the cross-sectional area of the part of the closed channel 30 at position a increases, which is larger than the cross-sectional area of the part of the closed channel 30 at position b. Thus, the asymmetric photo-deformation of the closed channel 30 at position a and position b generates a Laplace pressure difference, and under the action of the Laplace pressure difference, the microfluidics 40 spontaneously moves from the position a with a larger cross-sectional area to the position b with a smaller cross-sectional area, thereby realizing the photo-driven of the microfluidics 40. Using such a principle, the photo-driven of the microfluidics 40 can be precisely controlled by controlling the position and intensity of the light illumination. Such a photo-driven method does not require an external driving device and can achieve contactless driving of the microfluidics only by using a light source that meets the conditions. And the driving accuracy is also relatively high.

[0026] For example, when using the microfluidic chip 100, sample microfluidics can be added to the sample injection port 101 to enable the added sample microfluidics to enter the sample injection channel 102. The sample injection port 101 can also be in communication with other components on the microfluidic chip 100 to receive, as sample microfluidics, the microfluidics processed by the other components from the other components. Then, for example, Figure 5The method shown photo-optically drives the sample microfluid in the injection channel 102 to the first connection point between the first liquid bridge 104 and the injection channel 102, so that the sample microfluid spontaneously enters the first liquid bridge 104 under the action of the Laplace pressure difference generated by the cross-sectional area of the injection channel 102 being larger than that of the liquid measurement chamber 103 and fills the first liquid bridge 104, the liquid measurement chamber 103, and the second liquid bridge 107. Since there is a depth difference between the second liquid bridge 107 and the reaction channel 106, the sample microfluid will not enter the reaction channel 106 under the action of surface tension after filling the second liquid bridge 107. Next, the sample microfluid remaining in the injection channel 102 is photo-optically driven away from the first connection point, so that the sample microfluid in the injection channel 102 is separated from the sample microfluid in the first liquid bridge 104. In this way, a preset volume of the sample microfluid can be accurately measured, and the preset volume is basically equal to the volume of the liquid measurement chamber 103. Since the volume of the liquid measurement chamber 103 can be very small, in some examples, the volume of the liquid measurement chamber 103 can be between 50 nanoliters and 1000 nanoliters, or between 100 nanoliters and 700 nanoliters. Therefore, the measurement of such a preset volume of the sample microfluid can be regarded as a simple and accurate trace sample quantitative measurement. However, those skilled in the art can understand that when specifically designing the volume of the liquid measurement chamber 103, it can be determined according to the specific usage scenario of the microfluidic chip 100. After the sample microfluid in the injection channel 102 is separated from the sample microfluid in the first liquid bridge 104, the preset microfluid in the reaction channel 106 is photo-optically driven to the second connection point between the second liquid bridge 107 and the reaction channel 106, so that the preset microfluid in the reaction channel 106 contacts the sample microfluid in the second liquid bridge 107, so that the sample microfluid in the liquid measurement chamber 103 spontaneously enters the reaction channel 106 under the action of the Laplace pressure difference generated by the cross-sectional area of the liquid measurement chamber 103 being larger than that of the reaction channel 106 and mixes with the preset microfluid in the reaction channel 106 to obtain the first mixed microfluid. The first mixed microfluid is a mixture of the preset microfluid and a preset volume of the sample microfluid. It can be understood that when it is necessary to obtain a mixture of the preset microfluid and multiple preset volumes of the sample microfluid, a preset volume of the sample microfluid can be measured again according to a process similar to the process described above.For example, after obtaining the first mixed microfluid, the first mixed microfluid can be optically driven away from the second connection point in the reaction channel 106, and then the sample microfluid in the injection channel 102 can be optically driven to the first connection point, so that the sample microfluid re-enters the first liquid bridge 104 and fills the first liquid bridge 104, the volume measurement chamber 103 and the second liquid bridge 107. Next, after optically driving away the sample microfluid that still remains in the injection channel 102 from the first connection point so that the sample microfluid in the injection channel 102 is separated from the sample microfluid in the first liquid bridge 104, the first mixed microfluid in the reaction channel 106 is optically driven to the second connection point, so that the first mixed microfluid in the reaction channel 106 contacts the sample microfluid in the second liquid bridge 107, thereby enabling the sample microfluid in the volume measurement chamber 103 to enter the reaction channel 106 and mix with the first mixed microfluid in the reaction channel 106 to obtain a second mixed microfluid. The second mixed microfluid is a mixture of the preset microfluid and two preset volumes of the sample microfluid. The structure of the microfluidic chip 100 allows for repeated operations and can measure the same volume of trace samples multiple times. Therefore, by using the microfluidic chip 100 and its method for optically driving fluids, a mixture of the preset microfluid and one or more preset volumes of the sample microfluid can be easily prepared.

[0027] To facilitate the optical driving of the microfluids in the injection channel 102 and the reaction channel 106, in some embodiments, each of the injection channel 102 and the reaction channel 106 can be configured to remain in communication with the atmosphere. For example, at least one end of each of the injection channel 102 and the reaction channel 106 can be open to the atmosphere, such as as Figure 1 shown. In other embodiments, each of the injection channel 102 and the reaction channel 106 can also be arranged in a circular shape. The circular shape only requires the channel to be connected end to end, and there is no restriction on the channel profile. For example, the profile of the circular channel can be various suitable shapes such as polygons (such as triangles, quadrilaterals, pentagons), circles, ellipses, etc. In this way, the gas in the injection channel 102 and the reaction channel 106 is not likely to impede the optical driving of the microfluids in the injection channel 102 and the reaction channel 106.

[0028] It should be noted that during the quantitative measurement process, it is necessary to avoid the fluids in the injection channel 102 and the reaction channel 106 being simultaneously connected to the liquid bridge. Otherwise, the fluid will continuously flow from the injection channel 102 through the liquid bridge into the reaction channel 106 under the action of the Laplace pressure difference, thereby losing the function of quantitative measurement.

[0029] In some embodiments, the injection channel 102, the volume measurement chamber 103, and the reaction channel 106 can be arranged parallel to each other, such as as Figure 1As shown, this can make the layout of the microfluidic chip 100 more compact and thus have a smaller volume. In some embodiments, the sampling channel 102 can be configured as a U-shaped channel, and the first liquid bridge 104 can be connected downstream of the elbow section of the U-shaped channel. For example, as Figure 1 shown, this can help maintain the flow rate and flow volume of the sample microfluid in the sampling channel 102 within a controllable range. The elbow section of the U-shaped channel can also effectively achieve the effects of buffering and liquid storage, and also reduces the footprint of the sampling channel 102 in the microfluidic chip 100, making the arrangement of the sampling channel 102 more reasonable.

[0030] In some embodiments, the communication structure 105 can include a balance channel that communicates with the liquid measurement chamber 103 at one end and with the atmosphere at the other end, and the cross-sectional area of the balance channel is greater than or equal to the cross-sectional area of the sampling channel 102. For example, as Figure 1 shown, a balance channel is connected to each of the left and right ends of the liquid measurement chamber 103, and the balance channel can extend, for example, to a place not covered by the photo-deformable film 20 to communicate with the atmosphere. In some embodiments, the communication structure 105 can also include a balance chamber that communicates with the liquid measurement chamber 103 and has a vertically penetrating through-hole to communicate with the atmosphere, and the cross-sectional area of the balance chamber is greater than or equal to the cross-sectional area of the sampling channel 102. For example, as Figure 2 shown, the through-hole 1051 can vertically penetrate the substrate 10 and the photo-deformable film 20. Figure 2 The communication structure 105 of Figure 1 can have a significantly shorter length compared to the communication structure 105 of

[0031] This can not only make the layout of the microfluidic chip 100 more compact but also reduce the processing difficulty of the microfluidic chip 100. In some embodiments, the communication between the communication structure 105 and the atmosphere is switchable, and when the communication structure 105 is not in communication with the atmosphere, the liquid measurement chamber 103 stops measuring. For example, a plug can be provided at the through-hole 1051, and when the plug blocks the through-hole 1051, it can prevent fluid from continuing to enter the liquid measurement chamber 103. Figure 1 and Figure 2 shown. In other embodiments, referring to Figure 3 , the first liquid bridge 104 and the second liquid bridge 107 can be offset from each other. For example, the intersection of the virtual extension line of the second liquid bridge 107 and the sampling channel 102 can be located downstream of the first connection point of the first liquid bridge 104 and the sampling channel 102. By Figure 3Such an arrangement can facilitate the use of a linear light source to scan light in the left-right direction on the microfluidic chip 100, thereby simultaneously controlling the movement of the fluid in the injection channel 102 and the movement of the fluid in the reaction channel 106 without causing the fluid in the injection channel 102 and the fluid in the reaction channel 106 to be connected to the liquid bridge at the same time.

[0032] In some embodiments, reference Figure 4 The microfluidic chip 100 may further include a reaction chamber 108, which may be configured to communicate with the reaction channel 106 to receive one or more portions of a mixed microfluid (e.g., a first mixed microfluid, a second mixed microfluid, etc.) of a sample microfluid and a preset microfluid from the reaction channel. The reaction chamber 108 may provide a reaction site for the mixed microfluid for subsequent processing.

[0033] Figures 1 to 4 An embodiment of a microfluidic chip 100 including a single measuring liquid chamber 103 is shown, and the microfluidic chip 100 can measure multiple preset volumes of sample microfluids using the single measuring liquid chamber 103 by repeatedly operating the microfluidic chip 100. In other embodiments, the microfluidic chip according to the present disclosure may also include multiple measuring liquid chambers, so that the microfluidic chip can measure a desired volume of sample microfluids using a combination of measuring liquid chambers in the multiple measuring liquid chambers by a single operation.

[0034] Specifically, in some embodiments, the microfluidic chip may include a plurality of liquid metering chambers. Each of the plurality of liquid metering chambers is configured to communicate with the injection channel via a first liquid bridge corresponding to the liquid metering chamber to meter a preset volume of sample microfluidics corresponding to the liquid metering chamber from the injection channel, and is configured to communicate with the atmosphere via a communication structure corresponding to the liquid metering chamber. The reaction channel may be configured to communicate with each of the plurality of liquid metering chambers via a second liquid bridge corresponding to the liquid metering chamber to receive a preset volume of sample microfluidics corresponding to the liquid metering chamber from the liquid metering chamber. Similarly to the aforementioned microfluidic chip, the cross-sectional area of the injection channel is greater than the cross-sectional area of each of the plurality of liquid metering chambers, the cross-sectional area of each of the plurality of liquid metering chambers is greater than the cross-sectional area of the reaction channel, the cross-sectional area of the reaction channel is greater than the cross-sectional area of the first liquid bridge corresponding to each of the plurality of liquid metering chambers and greater than the cross-sectional area of the second liquid bridge corresponding to each of the plurality of liquid metering chambers, the cross-sectional area of the communication structure corresponding to each of the plurality of liquid metering chambers on the side adjacent to the liquid metering chamber is greater than or equal to the cross-sectional area of the injection channel, the depth of the injection channel is greater than the depth of the first liquid bridge corresponding to each of the plurality of liquid metering chambers, and the depth of the reaction channel is greater than the depth of the second liquid bridge corresponding to each of the plurality of liquid metering chambers. In some examples, the preset volume corresponding to each of the plurality of liquid metering chambers may be the same. In other examples, the preset volume corresponding to each of the plurality of liquid metering chambers may be different from the preset volume corresponding to other liquid metering chambers among the plurality of liquid metering chambers. In still other examples, the preset volume corresponding to each of the plurality of liquid metering chambers may not be an integer multiple of the preset volume corresponding to other liquid metering chambers among the plurality of liquid metering chambers.

[0035] In some embodiments, the connection of the connection structure corresponding to each liquid measuring chamber among the multiple liquid measuring chambers to the atmosphere is switchable, and when the connection structure is not connected to the atmosphere, the liquid measuring of the liquid measuring chamber corresponding to the connection structure stops. For example, the connection of the connection structure to the atmosphere can be controlled by any suitable switching mechanism. In some examples, a movable baffle or other closing structure can be provided at the opening of the connection structure that can be opened to the atmosphere. In some examples, the baffles for multiple connection structures can be integrated onto the same baffle card, so that the switching of different connection structures or their combinations can be achieved by moving the baffle card as a whole. In some embodiments, the connection of the connection structure to the atmosphere can be controlled by a light-responsive switching mechanism. Such a light-responsive switching mechanism can include a photo-deformable material. In some examples, the photo-deformable material may not close the opening of the connection structure when not exposed to light and may undergo photo-deformation (e.g., expansion) to close the opening of the connection structure when exposed to light. In other examples, the photo-deformable material may close the opening of the connection structure when not exposed to light and may undergo photo-deformation (e.g., contraction) to not close the opening of the connection structure when exposed to light. For example, a chamber containing a photo-deformable gel can be provided at the opening of the connection structure, or a film or thin plate formed of a photo-deformable material can be provided at the opening of the connection structure.

[0036] Thus, when operating a microfluidic chip including multiple liquid metering chambers, the following operations can be performed: according to the volume of the sample microfluid to be metered, making the communication structure corresponding to one or more of the multiple liquid metering chambers communicate with the atmosphere while making the communication structures corresponding to the remaining liquid metering chambers in the multiple liquid metering chambers not communicate with the atmosphere, and the sum of the preset volumes corresponding to the one or more liquid metering chambers is equal to the volume of the sample microfluid to be metered; adding the sample microfluid to the sample inlet so that the added sample microfluid enters the sample inlet channel; by selectively illuminating a part of the sample inlet channel, driving the sample microfluid in the sample inlet channel to the first connection point between the first liquid bridge corresponding to the one or more liquid metering chambers and the sample inlet channel, so that the sample microfluid enters the first liquid bridge corresponding to the one or more liquid metering chambers and fills the first liquid bridge corresponding to the one or more liquid metering chambers, the one or more liquid metering chambers, and the second liquid bridge corresponding to the one or more liquid metering chambers; by selectively illuminating a part of the sample inlet channel, driving the sample microfluid remaining in the sample inlet channel away from the first connection point, so that the sample microfluid in the sample inlet channel is separated from the sample microfluid in the first liquid bridge corresponding to the one or more liquid metering chambers; and after the sample microfluid in the sample inlet channel is separated from the sample microfluid in the first liquid bridge corresponding to the one or more liquid metering chambers, by selectively illuminating a part of the reaction channel, driving the preset microfluid in the reaction channel to the second connection point between the second liquid bridge corresponding to the one or more liquid metering chambers and the reaction channel, so that the preset microfluid in the reaction channel contacts the sample microfluid in the second liquid bridge corresponding to the one or more liquid metering chambers, thereby enabling the sample microfluid in the one or more liquid metering chambers to enter the reaction channel and mix with the preset microfluid in the reaction channel to obtain a mixed microfluid. For example, the sample microfluid can sequentially fill each of the one or more liquid metering chambers along the sample inlet channel from upstream to downstream. The sample microfluid in these liquid metering chambers can be received by the preset microfluid in the reaction channel after all of the one or more liquid metering chambers are filled with the sample microfluid, or the sample microfluid in each liquid metering chamber can be received by the preset microfluid in the reaction channel every time a liquid metering chamber is filled and then the next liquid metering chamber is filled. The specific operation is not particularly limited as long as it is ensured that the fluid in the sample inlet channel and the fluid in the reaction channel are not simultaneously connected to the first liquid bridge and the second liquid bridge corresponding to the same liquid metering chamber.

[0037] Figure 12 shows a microfluidic chip 100’, which compared with Figure 2The microfluidic chip 100 shown also includes a liquid measuring chamber 103', a corresponding first liquid bridge 104', a communication structure 105' and a second liquid bridge 107'. The liquid measuring chamber 103' is configured to communicate with the sampling channel 102 via the first liquid bridge 104' to measure a preset volume of sample microfluidics corresponding to the liquid measuring chamber 103' from the sampling channel 102, and is configured to communicate with the atmosphere via the communication structure 105'. The reaction channel 106 is configured to communicate with the liquid measuring chamber 103' via the second liquid bridge 107' to receive a preset volume of sample microfluidics corresponding to the liquid measuring chamber 103' from the liquid measuring chamber 103'. The cross-sectional area of the sampling channel 102 is larger than the cross-sectional area of the liquid measuring chamber 103', the cross-sectional area of the liquid measuring chamber 103' is larger than the cross-sectional area of the reaction channel 106, the cross-sectional area of the reaction channel 106 is larger than the cross-sectional area of the first liquid bridge 104' and larger than the cross-sectional area of the second liquid bridge 107', the cross-sectional area of the communication structure 105' on the side adjacent to the liquid measuring chamber 103' is larger than or equal to the cross-sectional area of the sampling channel 102, the depth of the sampling channel 102 is larger than the depth of the first liquid bridge 104', and the depth of the reaction channel 106 is larger than the depth of the second liquid bridge 107'.

[0038] The volume of the liquid measuring chamber 103' can be different from the volume of the liquid measuring chamber 103. For example, as Figure 12 shown, the volume of the liquid measuring chamber 103' is smaller than the volume of the liquid measuring chamber 103. Except for the different volumes, the other configurations of the liquid measuring chambers 103 and 103' can be the same. Here, it is assumed that the volume of the liquid measuring chamber 103' is 100 nanoliters and the volume of the liquid measuring chamber 103 is 150 nanoliters. Then, by operating the microfluidic chip 100' once, 100 nanoliters, 150 nanoliters or 250 nanoliters of sample microfluidics can be measured, and by operating the microfluidic chip 100' multiple times, integer multiples of 100 nanoliters, 150 nanoliters or 250 nanoliters of sample microfluidics can be measured.

[0039] When measuring 100 nanoliters of sample microfluidics, for example, the following operations can be performed: Connect the communication structure 105' to the atmosphere and disconnect the communication structure 105 from the atmosphere; Add sample microfluidics to the injection port 101 so that the added sample microfluidics enters the injection channel 102; By selectively illuminating a part of the injection channel 102, drive the sample microfluidics in the injection channel 102 to the first connection point between the first liquid bridge 104' and the injection channel 102, so that the sample microfluidics enters the first liquid bridge 104' and fills the first liquid bridge 104', the liquid measurement cavity 103', and the second liquid bridge 107'; By selectively illuminating a part of the injection channel 102, drive the sample microfluidics remaining in the injection channel 102 away from the first connection point between the first liquid bridge 104' and the injection channel 102, so that the sample microfluidics in the injection channel 102 is separated from the sample microfluidics in the first liquid bridge 104'; After the sample microfluidics in the injection channel 102 is separated from the sample microfluidics in the first liquid bridge 104', by selectively illuminating a part of the reaction channel 106, drive the pre-set microfluidics in the reaction channel 106 to the second connection point between the second liquid bridge 107' and the reaction channel 106, so that the pre-set microfluidics in the reaction channel 106 contacts the sample microfluidics in the second liquid bridge 107', thereby enabling the sample microfluidics in the liquid measurement cavity 103' to enter the reaction channel 106 and mix with the pre-set microfluidics in the reaction channel 106.

[0040] When measuring 150 nanoliters of sample microfluidics, for example, the following operations can be performed: Connect the communication structure 105 to the atmosphere and disconnect the communication structure 105' from the atmosphere; Add sample microfluidics to the injection port 101 so that the added sample microfluidics enters the injection channel 102; By selectively illuminating a part of the injection channel 102, drive the sample microfluidics in the injection channel 102 to the first connection point between the first liquid bridge 104 and the injection channel 102, so that the sample microfluidics enters the first liquid bridge 104 and fills the first liquid bridge 104, the liquid measurement cavity 103, and the second liquid bridge 107; By selectively illuminating a part of the injection channel 102, drive the sample microfluidics remaining in the injection channel 102 away from the first connection point between the first liquid bridge 104 and the injection channel 102, so that the sample microfluidics in the injection channel 102 is separated from the sample microfluidics in the first liquid bridge 104; After the sample microfluidics in the injection channel 102 is separated from the sample microfluidics in the first liquid bridge 104, by selectively illuminating a part of the reaction channel 106, drive the pre-set microfluidics in the reaction channel 106 to the second connection point between the second liquid bridge 107 and the reaction channel 106, so that the pre-set microfluidics in the reaction channel 106 contacts the sample microfluidics in the second liquid bridge 107, thereby enabling the sample microfluidics in the liquid measurement cavity 103 to enter the reaction channel 106 and mix with the pre-set microfluidics in the reaction channel 106.

[0041] When 250 nanoliters of sample microfluid is to be measured, for example, the following operations can be performed: connect the connecting structure 105 to the atmosphere and connect the connecting structure 105' to the atmosphere; add sample microfluid to the injection port 101 so that the added sample microfluid enters the injection channel 102; selectively expose the injection channel 102 locally to light, drive the sample microfluid in the injection channel 102 to the first connection point between the first liquid bridge 104 and the injection channel 102, so that the sample microfluid enters the first liquid bridge 104 and fills the first liquid bridge 104, the measuring liquid chamber 103 and the second liquid bridge 107; selectively expose the injection channel 102 locally to light, drive the sample microfluid still remaining in the injection channel 102 away from the first connection point between the first liquid bridge 104 and the injection channel 102, so that the sample microfluid in the injection channel 102 and the sample microfluid in the first liquid bridge 104 are connected. Separation; by selectively irradiating part of the injection channel 102 with light, the sample microfluid still retained in the injection channel 102 is driven to the first connection point between the first liquid bridge 104' and the injection channel 102, so that the sample microfluid enters the first liquid bridge 104' and fills the first liquid bridge 104', the liquid measuring chamber 103' and the second liquid bridge 107'; by selectively irradiating part of the injection channel 102 with light, the sample microfluid still retained in the injection channel 102 is driven away from the first connection point between the first liquid bridge 104' and the injection channel 102, so that the sample microfluid in the injection channel 102 is separated from the sample microfluid in the first liquid bridge 104'; after the sample microfluid in the injection channel 102 is separated from the sample microfluid in the first liquid bridge 104', by selectively irradiating part of the reaction channel 106 with light, the preset microfluid in the reaction channel 106 (assuming that Figure 12 The microfluid is pre-set in the reaction channel 106 and is located on the left side of the second liquid bridge 107', and is driven to the second connection point between the second liquid bridge 107' and the reaction channel 106, so that the pre-set microfluid in the reaction channel 106 contacts with the sample microfluid in the second liquid bridge 107', so that the sample microfluid in the liquid measuring chamber 103' enters the reaction channel 106 and is mixed with the pre-set microfluid in the reaction channel 106 to obtain a first mixed microfluid; by selectively irradiating the reaction channel 106 locally, the first mixed microfluid in the reaction channel 106 is driven to the second connection point between the second liquid bridge 107 and the reaction channel 106, so that the first mixed microfluid in the reaction channel 106 contacts with the sample microfluid in the second liquid bridge 107, so that the sample microfluid in the liquid measuring chamber 103 enters the reaction channel 106 and is mixed with the first mixed microfluid in the reaction channel 106 to obtain a second mixed microfluid.

[0042] Except for the different number of liquid measuring chambers, other embodiments of the microfluidic chip 100' are similar to the various embodiments of the microfluidic chip 100' described above, and will not be described in detail here.Figure 12 Only two liquid metering chambers are shown in the microfluidic chip 100', but the present disclosure is not limited thereto, and may include three or more liquid metering chambers. In some examples, the microfluidic chip 100' may include no more than three liquid metering chambers.

[0043] The present disclosure also provides, in another aspect, a method 200 for operating the microfluidic chips 100, 100' according to any one of the foregoing embodiments. Referring to Figure 6 , the method 200 includes: at step S202, adding a sample microfluid to the injection port 101 to cause the added sample microfluid to enter the injection channel 102; at step S204, by selectively illuminating a part of the injection channel 102, driving the sample microfluid in the injection channel 102 to the first connection point of the first liquid bridge 104 and the injection channel 102, so that the sample microfluid enters the first liquid bridge 104 and fills the first liquid bridge 104, the liquid metering chamber 103, and the second liquid bridge 107; at step S206, by selectively illuminating a part of the injection channel 102, driving the sample microfluid remaining in the injection channel 102 away from the first connection point, so that the sample microfluid in the injection channel 102 is separated from the sample microfluid in the first liquid bridge 104; at step S208, after the sample microfluid in the injection channel 102 is separated from the sample microfluid in the first liquid bridge 104, by selectively illuminating a part of the reaction channel 106, driving the preset microfluid in the reaction channel 106 to the second connection point of the second liquid bridge 107 and the reaction channel 106, so that the preset microfluid in the reaction channel 106 contacts the sample microfluid in the second liquid bridge 107, thereby causing the sample microfluid in the liquid metering chamber 103 to enter the reaction channel 106 and mix with the preset microfluid in the reaction channel 106 to obtain a first mixed microfluid.

[0044] In some embodiments, method 200 may further include: driving the first mixed microfluid in reaction channel 106 away from the second connection point by selectively illuminating a local portion of reaction channel 106; driving the sample microfluid in sample introduction channel 102 to the first connection point by selectively illuminating a local portion of sample introduction channel 102, such that the sample microfluid re-enters the first liquid bridge 104 and fills the first liquid bridge 104, the volume measurement chamber 103, and the second liquid bridge 107; driving the sample microfluid remaining in sample introduction channel 102 away from the first connection point by selectively illuminating a local portion of sample introduction channel 102, such that the sample microfluid in sample introduction channel 102 is separated from the sample microfluid in the first liquid bridge 104; after the sample microfluid in sample introduction channel 102 is separated from the sample microfluid in the first liquid bridge 104, driving the first mixed microfluid in reaction channel 106 to the second connection point by selectively illuminating a local portion of reaction channel 106, such that the first mixed microfluid in reaction channel 106 contacts the sample microfluid in the second liquid bridge 107, thereby causing the sample microfluid in the volume measurement chamber 103 to enter reaction channel 106 and mix with the first mixed microfluid in reaction channel 106 to obtain a second mixed microfluid. By repeating the above steps similarly, mixtures of the preset microfluid and more portions of the sample microfluid of a preset volume can be obtained.

[0045] In some embodiments, method 200 may further include: driving the mixed microfluid of one or more preset volumes of the sample microfluid and the preset microfluid (e.g., the first mixed microfluid, the second mixed microfluid, etc.) through reaction channel 106 into a reaction chamber or other channels or chambers communicating with reaction channel 106 by selectively illuminating a local portion of reaction channel 106 for subsequent operations.

[0046] In some embodiments, for the microfluidic chip 100', the method 200 may include: according to the volume of the sample microfluid to be measured, making the communication structure corresponding to one or more of the plurality of liquid measuring cavities communicate with the atmosphere and making the communication structures corresponding to the remaining liquid measuring cavities in the plurality of liquid measuring cavities not communicate with the atmosphere, the sum of the preset volumes corresponding to the one or more liquid measuring cavities being equal to the volume of the sample microfluid to be measured; adding the sample microfluid to the sample inlet so that the added sample microfluid enters the sample inlet channel; by selectively illuminating a part of the sample inlet channel, driving the sample microfluid in the sample inlet channel to the first connection point between the first liquid bridge corresponding to the one or more liquid measuring cavities and the sample inlet channel, so that the sample microfluid enters the first liquid bridge corresponding to the one or more liquid measuring cavities and fills the first liquid bridge corresponding to the one or more liquid measuring cavities, the one or more liquid measuring cavities, and the second liquid bridge corresponding to the one or more liquid measuring cavities; by selectively illuminating a part of the sample inlet channel, driving the sample microfluid remaining in the sample inlet channel away from the first connection point, so that the sample microfluid in the sample inlet channel is separated from the sample microfluid in the first liquid bridge corresponding to the one or more liquid measuring cavities; and after the sample microfluid in the sample inlet channel is separated from the sample microfluid in the first liquid bridge corresponding to the one or more liquid measuring cavities, by selectively illuminating a part of the reaction channel, driving the preset microfluid in the reaction channel to the second connection point between the second liquid bridge corresponding to the one or more liquid measuring cavities and the reaction channel, so that the preset microfluid in the reaction channel contacts the sample microfluid in the second liquid bridge corresponding to the one or more liquid measuring cavities, so that the sample microfluid in the one or more liquid measuring cavities enters the reaction channel and is mixed with the preset microfluid in the reaction channel to obtain a mixed microfluid.

[0047] Other embodiments of the method 200 may refer to those described above with respect to the microfluidic chips 100, 100' and will not be elaborated herein.

[0048] In yet another aspect, the present disclosure also provides a microfluidic device 300. Referring to Figure 7 , the microfluidic device 300 includes the microfluidic chip 100 (including the microfluidic chip 100') according to any of the foregoing embodiments and a light source 310 configured to provide light illumination to the microfluidic chip 100 to control the movement of the microfluid in the microfluidic chip 100. The light source 310 may take any suitable form such as a point light source, a line light source, a surface light source, an array light source, etc., and may be any suitable light source such as a light emitting diode (LED), a laser, etc. In some embodiments, when the first liquid bridge 104 and the second liquid bridge 107 are staggered from each other such that the intersection point of the virtual extension line of the second liquid bridge 107 and the sample inlet channel 102 is downstream of the first connection point between the first liquid bridge 104 and the sample inlet channel 102 (for example, asFigure 3 As shown in Figure 3 , the light source 310 may be a line light source, which may be configured to simultaneously control the movement of the microfluid in the sample injection channel 102 and the movement of the microfluid in the reaction channel 106. In some embodiments, the light source 310 may be configured to be movable relative to the microfluidic chip 100 to scan the illumination position on the microfluidic chip 100 so as to generate an asymmetric photo-deformation along the channel to drive the fluid. For example, the relative movement between the light source 310 and the microfluidic chip 100 may be achieved by fixing the light source 310 and moving the microfluidic chip 100, or by fixing the microfluidic chip 100 and moving the light source 310, or by moving the light source 310 and the microfluidic chip 100 simultaneously at different speeds, which is not particularly limited herein. In some embodiments, for example, as Figure 8 shown in Figure 8 , the light source 310 may include an array of multiple light sources 310_1, 310_2, 310_3, and each of the multiple light sources 310_1, 310_2, 310_3 has a different illumination position on the microfluidic chip 100. Thus, the switching of the illumination position can be achieved by turning on and off each light source. Although Figure 8 only three light sources 310_1, 310_2, 310_3 are shown in Figure 8 , this is merely exemplary and not restrictive. More light sources can be arranged as needed, and they can be arranged in any suitable array such as a one-dimensional array, a two-dimensional array, etc.

[0049] In Figure 7 the embodiments of Figure 7 , it can be understood that a scanning of the positive-phase light spot on the microfluidic chip 100 is provided. In some other embodiments, a scanning of the anti-phase light spot on the microfluidic chip 100 can also be provided. For example, referring to Figure 9, the microfluidic device 300 may further include a light-shielding sheet 320, which is disposed between the microfluidic chip 100 and the light source 310 and is configured to prevent the selectable portions of the sample injection channel 102 and the reaction channel 106 of the microfluidic chip 100 from receiving the light of the light source 310 while the remaining portions receive the light of the light source 310. The light source 310 may be configured, for example, to provide light illumination to the entire microfluidic chip 100, and the projection of the light-shielding sheet 320 on the microfluidic chip 100 provides an inverted light spot. Wherein the microfluidic chip 100 and the light source 310 may be stationary, and the light-shielding sheet 320 may be movable, so that different selectable portions of the sample injection channel 102 and the reaction channel 106 of the microfluidic chip 100 can be selected, which is equivalent to providing a scan of the inverted light spot. In some other embodiments, the light-shielding sheet 320 may also be configured to allow the selectable portions of the sample injection channel 102 and the reaction channel 106 of the microfluidic chip 100 to receive the light of the light source 310 while the remaining portions do not receive the light of the light source 310. For example, the light source 310 may be configured to provide light illumination to the entire microfluidic chip 100, and the light-shielding sheet 320 may block all light except for the openings provided for light leakage. In this case, the microfluidic chip 100 and the light source 310 may be stationary, and the light-shielding sheet 320 may be movable, so that different selectable portions of the sample injection channel 102 and the reaction channel 106 of the microfluidic chip 100 can be selected, which is still equivalent to providing a scan of the positive light spot.

[0050] In some other embodiments, referring to Figure 10 , the microfluidic device 300 may alternatively include a light attenuation sheet 330, which is disposed between the microfluidic chip 100 and the light source 310 and is configured to make the light of the light source 310 received by the selectable portions of the sample injection channel 102 and the reaction channel 106 of the microfluidic chip 100 have an attenuated intensity compared to the light of the light source 310 received by the remaining portions of the sample injection channel 102 and the reaction channel 106. The light source 310 may be configured, for example, to provide light illumination to the entire microfluidic chip 100, and the projection of the light attenuation sheet 330 on the microfluidic chip 100 provides an attenuated light spot. Wherein the microfluidic chip 100 and the light source 310 may be stationary, and the light attenuation sheet 330 may be movable, so that different selectable portions of the sample injection channel 102 and the reaction channel 106 of the microfluidic chip 100 can be selected, which is equivalent to providing a scan of the attenuated light spot.

[0051] It can be understood that although it is described above that the light-shielding sheet 320 or the light attenuation sheet 320 moves while the light source 310 and the microfluidic chip 100 are stationary, this is merely exemplary and not restrictive. The relative movement between the above components can be achieved in various ways as long as the scanning of the positive light spot, the inverted light spot or the attenuated light spot on the microfluidic chip 100 can be realized.

[0052] To provide an automation level for the microfluidic device 300, in some embodiments, referring to Figure 11 , the microfluidic device 300 may further include a controller 340. The controller 340 may be configured to execute the method 200 shown in any of the foregoing embodiments. For example, the controller 340 may be configured to: control the light source 310 to drive the sample microfluid in the sampling channel 102 to the first connection point of the first liquid bridge 104 and the sampling channel 102 by selectively illuminating a part of the sampling channel 102, so that the sample microfluid enters the first liquid bridge 104 and fills the first liquid bridge 104, the liquid measuring chamber 103 and the second liquid bridge 107; control the light source 310 to drive the sample microfluid remaining in the sampling channel 102 away from the first connection point by selectively illuminating a part of the sampling channel 102, so that the sample microfluid in the sampling channel 102 is separated from the sample microfluid in the first liquid bridge 104; after the sample microfluid in the sampling channel 102 is separated from the sample microfluid in the first liquid bridge 104, control the light source 310 to drive the preset microfluid in the reaction channel 106 to the second connection point of the second liquid bridge 107 and the reaction channel 106 by selectively illuminating a part of the reaction channel 106, so that the preset microfluid in the reaction channel 106 contacts the sample microfluid in the second liquid bridge 107, thereby enabling the sample microfluid in the liquid measuring chamber 103 to enter the reaction channel 106 and mix with the preset microfluid in the reaction channel 106 to obtain a first mixed microfluid.

[0053] In some embodiments, the controller 340 may also be configured to: control the light source 310 to drive the first mixed microfluid in the reaction channel 106 away from the second connection point by selectively illuminating a part of the reaction channel 106; control the light source 310 to drive the sample microfluid in the sample injection channel 102 to the first connection point by selectively illuminating a part of the sample injection channel 102, so that the sample microfluid re-enters the first liquid bridge 104 and fills the first liquid bridge 104, the liquid measuring chamber 103 and the second liquid bridge 107; control the light source 310 to drive the sample microfluid remaining in the sample injection channel 102 away from the first connection point by selectively illuminating a part of the sample injection channel 102, so that the sample microfluid in the sample injection channel 102 is separated from the sample microfluid in the first liquid bridge 104; after the sample microfluid in the sample injection channel 102 is separated from the sample microfluid in the first liquid bridge 104, control the light source 310 to drive the first mixed microfluid in the reaction channel 106 to the second connection point by selectively illuminating a part of the reaction channel 106, so that the first mixed microfluid in the reaction channel 106 contacts the sample microfluid in the second liquid bridge 107, thereby enabling the sample microfluid in the liquid measuring chamber 103 to enter the reaction channel 106 and mix with the first mixed microfluid in the reaction channel 106 to obtain a second mixed microfluid. The controller 340 repeats the above steps similarly to obtain a mixture of the preset microfluid and more portions of the sample microfluid with a preset volume.

[0054] In some embodiments, the controller 340 may also be configured to control the light source 310 to drive a mixed microfluid of one or more portions of the sample microfluid with a preset volume and the preset microfluid (e.g., the first mixed microfluid, the second mixed microfluid, etc.) through the reaction channel 106 into a reaction chamber or other channels or chambers communicating with the reaction channel 106 for subsequent operations.

[0055] The microfluidic chip and the microfluidic device according to the present disclosure effectively utilize the Laplace pressure difference generated by the asymmetric photo-deformation of the channel, and realize the non-contact precise driving of the microfluid only by using a simple light source without any external driving equipment. Moreover, the precise quantitative trace measurement operation at the back end can be realized without filling the entire front channel, with low sample loss, few components, small overall volume, simple and robust structure, high repeatability, and high portability and automation.

[0056] In the specification and claims, words such as "left", "right", "front", "back", "top", "bottom", "upper", "lower", "higher", "lower", etc., if present, are used for descriptive purposes and not necessarily to describe an invariant relative position. It should be understood that such words are interchangeable under appropriate circumstances, such that the embodiments of the present disclosure described herein, for example, can operate in other orientations different from those shown or otherwise described herein. For example, when the device in the drawings is inverted, a feature previously described as "above" other features can then be described as "below" the other features. The device can also be oriented in other ways (rotated 90 degrees or in other orientations), and the relative spatial relationships will be interpreted accordingly.

[0057] In the specification and claims, when an element is referred to as being "above", "attached" to, "connected" to, "coupled" to, "operatively coupled" to, or "in contact" with another element, etc., the element can be directly above, directly attached to, directly connected to, directly coupled to, directly operatively coupled to, or directly in contact with the other element, or there can be one or more intervening elements. In contrast, when an element is referred to as being "directly" above, "directly attached" to, "directly connected" to, "directly coupled" to, "directly operatively coupled" to, or "directly in contact" with another element, there will be no intervening elements. In the specification and claims, a feature being arranged "adjacent" to another feature can mean that the feature has a portion that overlaps with the adjacent feature or a portion that is above or below the adjacent feature.

[0058] As used herein, the word "exemplary" means "serving as an example, instance, or illustration" and not as a "model" to be precisely replicated. Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Moreover, the present disclosure is not limited by any theory, whether expressed or implied, given in the technical field, background art, summary of the invention, or detailed description.

[0059] As used herein, the word "substantially" means including any minor variations due to design or manufacturing defects, tolerances of devices or components, environmental effects, and / or other factors. The word "substantially" also allows for differences from perfect or ideal situations due to parasitic effects, noise, and other practical considerations that may exist in an actual implementation.

[0060] Additionally, for reference purposes only, terms such as "first", "second", and the like may also be used herein and are not intended to be limiting. For example, unless the context clearly indicates otherwise, the words "first", "second", and other such numerical words referring to a structure or element do not imply an order or sequence.

[0061] It should also be understood that when the term "comprising / including" is used herein, it indicates the presence of the stated features, wholes, steps, operations, units, and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, units, and / or components and / or combinations thereof.

[0062] In this disclosure, the term "provide" is used in a broad sense to cover all ways of obtaining an object. Thus, "providing an object" includes, but is not limited to, "purchasing", "preparing / manufacturing", "arranging / setting", "installing / assembling", and / or "ordering" the object, etc.

[0063] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit this disclosure. As used herein, the singular forms "a", "an", and "the" are also intended to include the plural forms unless the context clearly indicates otherwise.

[0064] Those skilled in the art should be aware that the boundaries between the above operations are merely illustrative. Multiple operations can be combined into a single operation, a single operation can be distributed among additional operations, and operations can be performed at least partially overlapping in time. Moreover, alternative embodiments can include multiple instances of a particular operation, and the order of operations can be varied in various other embodiments. However, other modifications, variations, and substitutions are also possible. The aspects and elements of all the embodiments disclosed above can be combined in any manner and / or in combination with aspects or elements of other embodiments to provide multiple additional embodiments. Therefore, this specification and the drawings should be regarded as illustrative rather than restrictive.

[0065] Although some specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and not for limiting the scope of this disclosure. The embodiments disclosed herein can be combined arbitrarily without departing from the spirit and scope of this disclosure. Those skilled in the art should also understand that various modifications can be made to the embodiments without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A microfluidic chip, comprising: An injection port configured to receive sample microfluid; An injection channel configured to communicate with the injection port to receive sample microfluid from the injection port, the injection channel including a photo-deformable material such that the microfluid can be driven through the injection channel under the action of the Laplace pressure difference generated by the asymmetric photo-deformation of the injection channel; A metering chamber configured to communicate with the injection channel via a first liquid bridge to meter a preset volume of sample microfluid from the injection channel, and configured to communicate with the atmosphere via a communication structure; And A reaction channel configured to communicate with the metering chamber via a second liquid bridge to receive the preset volume of sample microfluid from the metering chamber, and a preset microfluid is stored at a position separated from the second liquid bridge in the reaction channel, the reaction channel including a photo-deformable material such that the microfluid can be driven through the reaction channel under the action of the Laplace pressure difference generated by the asymmetric photo-deformation of the reaction channel, Wherein, the cross-sectional area of the injection channel is greater than the cross-sectional area of the metering chamber, the cross-sectional area of the metering chamber is greater than the cross-sectional area of the reaction channel, the cross-sectional area of the reaction channel is greater than the cross-sectional area of the first liquid bridge and greater than the cross-sectional area of the second liquid bridge, the cross-sectional area of the communication structure on the side adjacent to the metering chamber is greater than or equal to the cross-sectional area of the injection channel, and Wherein, the depth of the injection channel is greater than the depth of the first liquid bridge, and the depth of the reaction channel is greater than the depth of the second liquid bridge.

2. The microfluidic chip according to claim 1, wherein The injection channel is configured as a U-shaped channel, and the first liquid bridge is connected downstream of the elbow section of the U-shaped channel.

3. The microfluidic chip according to claim 1, wherein, The communication structure includes a balance channel that communicates with the metering chamber at one end and communicates with the atmosphere at the other end, and the cross-sectional area of the balance channel is greater than or equal to the cross-sectional area of the injection channel; Or The communication structure includes a balance chamber that communicates with the metering chamber and has a vertical through-hole to communicate with the atmosphere, and the cross-sectional area of the balance chamber is greater than or equal to the cross-sectional area of the injection channel.

4. The microfluidic chip according to claim 1, wherein, The communication between the communication structure and the atmosphere is switchable, and when the communication structure is not in communication with the atmosphere, the metering chamber stops metering.

5. The microfluidic chip according to claim 1, wherein The first liquid bridge and the second liquid bridge are aligned with each other.

6. The microfluidic chip according to claim 1, wherein The first liquid bridge and the second liquid bridge are offset from each other such that the intersection of the virtual extension line of the second liquid bridge and the injection channel is downstream of the first connection point of the first liquid bridge and the injection channel.

7. The microfluidic chip according to claim 1, wherein, The width and depth of each of the injection channel, the first liquid bridge, the metering chamber, the second liquid bridge and the reaction channel are respectively between 10 microns and 2000 microns.

8. The microfluidic chip according to claim 1, wherein, The volume of the metering chamber is between 50 nanoliters and 1000 nanoliters.

9. The microfluidic chip according to claim 1, wherein The difference in depth between the first liquid bridge and the injection channel is configured to allow microfluid to move across the first connection point between the first liquid bridge and the injection channel in the injection channel, and the difference in depth between the second liquid bridge and the reaction channel is configured to allow microfluid to move across the second connection point between the second liquid bridge and the reaction channel in the reaction channel.

10. The microfluidic chip according to claim 1, wherein, The ratio of the depth of the first liquid bridge to the depth of the injection channel is less than 1:2, and the ratio of the depth of the second liquid bridge to the depth of the reaction channel is less than 1:

2.

11. The microfluidic chip according to claim 1, wherein, The ratio of the depth of the first liquid bridge to the depth of the injection channel is less than or equal to 1:4, and the ratio of the depth of the second liquid bridge to the depth of the reaction channel is less than or equal to 1:

4.

12. The microfluidic chip according to claim 1, wherein, The pre-set microfluid can be driven to the second connection point between the second liquid bridge and the reaction channel under the Laplace pressure difference generated by the asymmetric photo-induced deformation of the reaction channel to contact and mix with the pre-set volume of sample microfluid received from the metering cavity in the reaction channel to obtain a first mixed microfluid.

13. The microfluidic chip according to claim 1, wherein, The photo-responsive deformation material is configured to expand in response to being irradiated with light, so that the cross-sectional areas of parts of the injection channel and the reaction channel when irradiated with light are larger than those when not irradiated with light, thereby driving microfluid in the injection channel and the reaction channel in the direction of decreasing light intensity; Or The photo-responsive deformation material is configured to contract in response to being irradiated with light, so that the cross-sectional areas of parts of the injection channel and the reaction channel when irradiated with light are smaller than those when not irradiated with light, thereby driving microfluid in the injection channel and the reaction channel in the direction of increasing light intensity.

14. The microfluidic chip according to claim 1, wherein, The photo-responsive deformation material includes a photo-responsive liquid crystal polymer material.

15. The microfluidic chip according to claim 14, wherein, The photo-responsive liquid crystal polymer material includes a photo-responsive linear liquid crystal polymer material with a main chain of polycyclooctene and side chains containing azobenzene.

16. The microfluidic chip according to claim 1, further comprising: A reaction cavity, configured to communicate with the reaction channel to receive the first mixed microfluid of the pre-set volume of sample microfluid and the pre-set microfluid from the reaction channel.

17. The microfluidic chip according to claim 1, wherein, The pre-set microfluid is added to the reaction channel during the use stage of the microfluidic chip, or is added to the reaction channel during the manufacturing stage of the microfluidic chip.

18. The microfluidic chip according to claim 1, wherein, The microfluidic chip includes a plurality of metering cavities, each of the plurality of metering cavities is configured to communicate with the injection channel via a first liquid bridge corresponding to the metering cavity to measure a pre-set volume of sample microfluid corresponding to the metering cavity from the injection channel, and is configured to communicate with the atmosphere via a communication structure corresponding to the metering cavity, and the reaction channel is configured to communicate with each of the plurality of metering cavities via a second liquid bridge corresponding to the metering cavity to receive a pre-set volume of sample microfluid corresponding to the metering cavity from the metering cavity, Wherein, the cross-sectional area of the sample injection channel is larger than the cross-sectional area of each of the plurality of liquid metering chambers, the cross-sectional area of each of the plurality of liquid metering chambers is larger than the cross-sectional area of the reaction channel, the cross-sectional area of the reaction channel is larger than the cross-sectional area of the first liquid bridge corresponding to each of the plurality of liquid metering chambers and larger than the cross-sectional area of the second liquid bridge corresponding to each of the plurality of liquid metering chambers, and the cross-sectional area of the communication structure corresponding to each of the plurality of liquid metering chambers on the side adjacent to the liquid metering chamber is greater than or equal to the cross-sectional area of the sample injection channel, and wherein, the depth of the sample injection channel is greater than the depth of the first liquid bridge corresponding to each of the plurality of liquid metering chambers, and the depth of the reaction channel is greater than the depth of the second liquid bridge corresponding to each of the plurality of liquid metering chambers.

19. The microfluidic chip according to claim 18, wherein, The preset volume corresponding to each of the plurality of liquid metering chambers is different from the preset volumes corresponding to the other liquid metering chambers among the plurality of liquid metering chambers, and wherein, the communication between the communication structure corresponding to each of the plurality of liquid metering chambers and the atmosphere is switchable, and when the communication structure is not in communication with the atmosphere, the liquid metering chamber corresponding to the communication structure stops metering.

20. The microfluidic chip according to any one of claims 1 to 19, comprising: a substrate having the sample injection port and a groove communicated with the sample injection port provided thereon; and a photo-deformable film attached to the substrate, the photo-deformable film at least partially covering the groove so as to form a closed channel together with the groove, such that the microfluid can be driven to pass through the closed channel under the action of the Laplace pressure difference generated by the asymmetric photo-deformation of the closed channel, and the closed channel includes the sample injection channel and the reaction channel.

21. A method for operating the microfluidic chip according to any one of claims 1 to 20, comprising: adding a sample microfluid to the sample injection port to enable the added sample microfluid to enter the sample injection channel; driving the sample microfluid in the sample injection channel to the first connection point between the first liquid bridge and the sample injection channel by selectively irradiating a part of the sample injection channel with light, such that the sample microfluid enters the first liquid bridge and fills the first liquid bridge, the liquid metering chamber and the second liquid bridge; driving the sample microfluid remaining in the sample injection channel away from the first connection point by selectively irradiating a part of the sample injection channel with light, such that the sample microfluid in the sample injection channel is separated from the sample microfluid in the first liquid bridge; and after the sample microfluid in the sample injection channel is separated from the sample microfluid in the first liquid bridge, driving the preset microfluid in the reaction channel to the second connection point between the second liquid bridge and the reaction channel by selectively irradiating a part of the reaction channel with light, such that the preset microfluid in the reaction channel contacts the sample microfluid in the second liquid bridge, thereby enabling the sample microfluid in the liquid metering chamber to enter the reaction channel and mix with the preset microfluid in the reaction channel to obtain a first mixed microfluid.

22. The method according to claim 21 further comprises: driving the first mixed microfluid through the reaction channel into a reaction chamber communicating with the reaction channel by selectively locally illuminating the reaction channel.

23. The method according to claim 21 further comprises: driving the first mixed microfluid in the reaction channel away from the second connection point by selectively locally illuminating the reaction channel; driving the sample microfluid in the sampling channel to the first connection point by selectively locally illuminating the sampling channel, so that the sample microfluid re-enters the first liquid bridge and fills the first liquid bridge, the liquid measuring chamber and the second liquid bridge; driving the sample microfluid remaining in the sampling channel away from the first connection point by selectively locally illuminating the sampling channel, so that the sample microfluid in the sampling channel is separated from the sample microfluid in the first liquid bridge; and after the sample microfluid in the sampling channel is separated from the sample microfluid in the first liquid bridge, driving the first mixed microfluid in the reaction channel to the second connection point by selectively locally illuminating the reaction channel, so that the first mixed microfluid in the reaction channel contacts the sample microfluid in the second liquid bridge, thereby enabling the sample microfluid in the liquid measuring chamber to enter the reaction channel and mix with the first mixed microfluid in the reaction channel to obtain a second mixed microfluid.

24. The method according to claim 21, wherein The method is used to operate the microfluidic chip according to claim 19, and wherein the method comprises: making the communication structure corresponding to one or more of the plurality of liquid measuring chambers communicate with the atmosphere and making the communication structures corresponding to the remaining liquid measuring chambers in the plurality of liquid measuring chambers not communicate with the atmosphere according to the volume of the sample microfluid to be measured, and the sum of the preset volumes corresponding to the one or more liquid measuring chambers is equal to the volume of the sample microfluid to be measured; adding sample microfluid to the sampling port so that the added sample microfluid enters the sampling channel; driving the sample microfluid in the sampling channel to the first connection point between the first liquid bridge corresponding to the one or more liquid measuring chambers and the sampling channel by selectively locally illuminating the sampling channel, so that the sample microfluid enters the first liquid bridge corresponding to the one or more liquid measuring chambers and fills the first liquid bridge corresponding to the one or more liquid measuring chambers, the one or more liquid measuring chambers and the second liquid bridge corresponding to the one or more liquid measuring chambers; driving the sample microfluid remaining in the sampling channel away from the first connection point by selectively locally illuminating the sampling channel, so that the sample microfluid in the sampling channel is separated from the sample microfluid in the first liquid bridge corresponding to the one or more liquid measuring chambers; and After the sample microfluid in the injection channel is separated from the sample microfluid in the first liquid bridge corresponding to the one or more metering cavities, by selectively illuminating a part of the reaction channel, the preset microfluid in the reaction channel is driven to the second connection point of the reaction channel and the second liquid bridge corresponding to the one or more metering cavities, so that the preset microfluid in the reaction channel contacts the sample microfluid in the second liquid bridge corresponding to the one or more metering cavities, thereby enabling the sample microfluid in the one or more metering cavities to enter the reaction channel and mix with the preset microfluid in the reaction channel to obtain a mixed microfluid.

25. A microfluidic device, comprising the microfluidic chip according to any one of claims 1 to 20 and a light source configured to provide light illumination to the microfluidic chip to control the movement of the microfluid in the microfluidic chip.

26. The microfluidic device according to claim 25, wherein, The microfluidic chip is the microfluidic chip according to claim 6, and the light source is a linear light source configured to simultaneously control the movement of the microfluid in the injection channel and the movement of the microfluid in the reaction channel.

27. The microfluidic device according to claim 25, wherein, the light source is configured to be movable relative to the microfluidic chip to scan the light illumination position on the microfluidic chip; or the light source comprises an array of a plurality of light sources, and each light source in the plurality of light sources has a different light illumination position on the microfluidic chip.

28. The microfluidic device according to claim 25, further comprising one of the following: a light shield disposed between the microfluidic chip and the light source and configured to allow a selectable portion of the injection channel and the reaction channel of the microfluidic chip to receive the light illumination from the light source while the remaining portions do not receive the light illumination from the light source, or configured to prevent a selectable portion of the injection channel and the reaction channel of the microfluidic chip from receiving the light illumination from the light source while the remaining portions receive the light illumination from the light source; or a light attenuation sheet disposed between the microfluidic chip and the light source and configured to cause the light illumination received by a selectable portion of the injection channel and the reaction channel of the microfluidic chip to have an attenuated intensity compared to the light illumination received by the remaining portions of the injection channel and the reaction channel.

29. The microfluidic device according to claim 28, wherein, the microfluidic chip and the light source are fixed, and the light shield or the light attenuation sheet is movable, so as to be able to select different selectable portions of the injection channel and the reaction channel of the microfluidic chip.

30. The microfluidic device according to claim 25, further comprising a controller configured to: control the light source to drive the sample microfluid in the injection channel to the first connection point of the first liquid bridge and the injection channel by selectively illuminating a part of the injection channel, so that the sample microfluid enters the first liquid bridge and fills the first liquid bridge, the metering cavity and the second liquid bridge; Control the light source to drive the sample microfluidics remaining in the sample injection channel away from the first connection point by selectively illuminating a part of the sample injection channel, so that the sample microfluidics in the sample injection channel is separated from the sample microfluidics in the first liquid bridge; And After the sample microfluidics in the sample injection channel is separated from the sample microfluidics in the first liquid bridge, control the light source to drive the preset microfluidics in the reaction channel to the second connection point between the second liquid bridge and the reaction channel by selectively illuminating a part of the reaction channel, so that the preset microfluidics in the reaction channel contacts the sample microfluidics in the second liquid bridge, thereby enabling the sample microfluidics in the volume measurement chamber to enter the reaction channel and mix with the preset microfluidics in the reaction channel to obtain a first mixed microfluidic.

31. The microfluidic device according to claim 30, wherein, The controller is further configured to: Control the light source to drive the first mixed microfluidic through the reaction channel into a reaction chamber communicating with the reaction channel by selectively illuminating a part of the reaction channel.

32. The microfluidic device according to claim 30, wherein, The controller is further configured to: Control the light source to drive the first mixed microfluidic away from the second connection point in the reaction channel by selectively illuminating a part of the reaction channel; Control the light source to drive the sample microfluidics in the sample injection channel to the first connection point by selectively illuminating a part of the sample injection channel, so that the sample microfluidics re-enters the first liquid bridge and fills the first liquid bridge, the volume measurement chamber, and the second liquid bridge; Control the light source to drive the sample microfluidics remaining in the sample injection channel away from the first connection point by selectively illuminating a part of the sample injection channel, so that the sample microfluidics in the sample injection channel is separated from the sample microfluidics in the first liquid bridge; And After the sample microfluidics in the sample injection channel is separated from the sample microfluidics in the first liquid bridge, control the light source to drive the first mixed microfluidic in the reaction channel to the second connection point by selectively illuminating a part of the reaction channel, so that the first mixed microfluidic in the reaction channel contacts the sample microfluidics in the second liquid bridge, thereby enabling the sample microfluidics in the volume measurement chamber to enter the reaction channel and mix with the first mixed microfluidic in the reaction channel to obtain a second mixed microfluidic.

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