An electrokinetic micro-mixing device and method based on asymmetric aperture array

Abstract

The application provides an electric micro-mixing device and method based on asymmetric hole array. The device comprises a PDMS cover layer, a glass substrate layer and an electrode layer. The PDMS cover layer is used for forming a micro-channel structure, and comprises an inlet and outlet area, a channel area and an asymmetric hole area. The glass substrate layer is bonded with the PDMS cover layer. The electrode layer comprises a first electrode plate, a second electrode plate, a third electrode plate, a fourth electrode plate, a fifth electrode plate and a sixth electrode plate. The electrode plates are embedded in the PDMS cover layer and are connected with three pairs of asymmetric micro-holes respectively. The asymmetric micro-holes are arranged on the side wall of the micro-channel and are connected with an external electric field by using electric field driving technology. When the sample solution injected into the main micro-channel passes through the electric field, the flow direction is deflected by the electric field force, and a vortex is formed near the asymmetric micro-holes to promote the mixing of the sample, the mixing efficiency is high, and the mixing effect of the fluid can be flexibly controlled by adjusting the electric field signal, so that samples with different mixing degrees are obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microfluidic technology, and in particular, especially to an electric micro-mixing device and method based on asymmetric hole array. BACKGROUND

[0002] Microfluidic technology is a new technology for precise operation and control of fluid at micron or even nanometer level. It is widely used in medical, chemical, biomedical and other aspects due to its small scale, easy integration, multiplexing and high throughput screening. In these aspects, the mixing of microfluids plays a crucial role. Micro-mixing is a basic physical phenomenon in micro-mixers. Some biological processes that require rapid reaction, such as DNA hybridization, cell activation, enzyme reaction, protein folding, etc. inevitably involve the mixing of reactants. Rapid and uniform mixing is of great significance to microfluidic systems in the fields of chemical synthesis, biochemical analysis, drug delivery, nucleic acid sequencing or synthesis, etc. Researchers have found that due to the small Reynolds number of fluid at microscale, most of the fluid flows in the form of laminar flow. This flow form causes the layers of fluid to be parallel to each other, making mixing difficult to occur.

[0003] The existing micro-mixers can be divided into two categories according to the different mixing mechanisms. One of them is a micro-mixer that does not require external energy to drive the mixing of fluid. This type of micro-mixer is called passive micro-mixer. This type of micro-mixer mainly relies on molecular diffusion and chaotic convection to mix the fluid, but this type of micro-mixer generally has poor mixing effect and long mixing time. It is necessary to change the geometry of the microchannel, the structure inside the channel to stretch, fold, repeat and interleave the fluid inside to increase the contact area between the parallel fluids, thereby promoting mixing. There are many configurations of passive micro-mixers, mainly including parallel layer shape, disc type, tree shape, groove shape, etc. The characteristics of these micro-mixers are simple process, good sealing, and input sample is not easy to be contaminated. However, this type of micro-mixer needs to increase the length of the channel to prolong the mixing time to achieve the required mixing effect. Therefore, this type of micro-mixer has low efficiency in the mixing process of fluid, and the shape is fixed for use, which is not flexible enough, and often can only be used once.

[0004] Another micro-mixer needs to rely on external energy to drive, and then achieves the purpose of mixing, such micro-mixer is called active micro-mixer, which needs to be driven by external force to change the flow state of fluid in the original micro-channel. The existing active micro-mixer can be divided into electric field driving, magnetic field driving, acoustic field driving and pressure driving according to the driving mode, and the characteristics of these micro-mixers are that they do not need to increase the length of the channel to improve the mixing effect, reduce the mixing time, improve the mixing efficiency and operate flexibly. In the process of use, the mixing can be adjusted by controlling the external input energy, and the channel configuration is simple and easy to manufacture. In recent years, the electric driving type micro-mixer provides a new method for the mixing of fluid at micro scale. The movement mode of fluid in the micro-channel will change under the action of electric field force, which breaks the original laminar flow state and promotes mixing. The electric driving type micro-mixer relies on the addition of direct current or alternating current signal source to promote mixing, but since it needs to add a driving unit on the microchip, the electrode sheet directly contacts the input solution and the addition of higher input signal source will cause pollution to the input fluid, which is a problem that needs to be solved so far. SUMMARY

[0005] According to the technical problems of poor mixing effect, high input voltage and easy pollution of sample solution of the existing micro-mixing device, an electric micro-mixing device and method based on asymmetric hole array are provided. The micro-mixing device provides an alternating current signal source through the electrode sheet embedded on both sides of the micro-channel, and provides an asymmetric electric field through the asymmetric micro-holes on both sides. During the mixing process, different mixing effects can be obtained by changing the applied alternating voltage value. The micro-mixing device has simple channel structure and obvious effect, and can effectively create conditions for the mixing of micro-fluid.

[0006] The technical means adopted by the present application are as follows:

[0007] An electric micro-mixing device based on asymmetric hole array, comprising: a PDMS cover layer, a glass substrate layer and an electrode layer;

[0008] The PDMS cover layer is used to form a micro-channel structure, comprising an inlet and outlet area, a channel area and an asymmetric hole area.

[0009] The glass substrate layer is bonded with the PDMS cover layer.

[0010] The electrode layer comprises a first electrode plate, a second electrode plate, a third electrode plate, a fourth electrode plate, a fifth electrode plate and a sixth electrode plate.

[0011] Further, on the PDMS cover layer, the following is specifically provided:

[0012] The inlet and outlet area comprises a first inlet, a second inlet and an outlet.

[0013] The channel region comprises a first sample inlet channel, a second sample inlet channel and a main microchannel.

[0014] The asymmetric pore region comprises a first asymmetric microhole, a second asymmetric microhole and a third asymmetric microhole.

[0015] Further, in the electrode layer, the following is specifically provided:

[0016] The first electrode plate and the second electrode plate are respectively embedded in the PDMS cover layer and arranged on both sides of the first asymmetric microhole.

[0017] The third electrode plate and the fourth electrode plate are respectively embedded in the PDMS cover layer and arranged on both sides of the second asymmetric microhole.

[0018] The fifth electrode plate and the sixth electrode plate are respectively embedded in the PDMS cover layer and arranged on both sides of the third asymmetric microhole.

[0019] Further, the first inlet is connected to the main microchannel through the first sample inlet channel; the second inlet is connected to the main microchannel through the second sample inlet channel; and the main microchannel is connected to the outlet.

[0020] Further, the first electrode plate, the second electrode plate, the third electrode plate, the fourth electrode plate, the fifth electrode plate and the sixth electrode plate are connected to an external power supply.

[0021] Further, the first asymmetric microhole, the second asymmetric microhole and the third asymmetric microhole are arranged on both sides of the main microchannel near the inlet and are respectively connected to the first electrode plate, the second electrode plate, the third electrode plate, the fourth electrode plate, the fifth electrode plate and the sixth electrode plate.

[0022] Further, the first electrode plate, the second electrode plate, the third electrode plate, the fourth electrode plate, the fifth electrode plate and the sixth electrode plate are the same in structure and size.

[0023] Further, the first asymmetric microhole, the second asymmetric microhole and the third asymmetric microhole respectively comprise five groups of small holes and one group of large holes, and each of the five groups of small holes and each of the one group of large holes is symmetrically arranged on both sides of the main microchannel to form the first asymmetric microhole, the second asymmetric microhole and the third asymmetric microhole; wherein the diameter of each small hole is 10 μm and the diameter of each large hole is 500 μm.

[0024] The application also provides a microfluidic mixing method based on the above-mentioned asymmetric pore array-based electric micro-mixing device, comprising:

[0025] S1, inject the mixed solution into the first inlet, and inject another solution with different concentration into the second inlet, the injection speed of the two inlets is same;

[0026] S2, open the signal source, apply AC signal to the first electrode, the third electrode plate and the fifth electrode plate, the second electrode, the fourth electrode plate and the sixth electrode plate are grounded; at the same time, observe the flow and mixing of the input sample on the main microchannel;

[0027] S3, adjust the AC signal applied to the first electrode, the third electrode plate and the fifth electrode plate until the desired mixing effect is obtained.

[0028] Compared with the prior art, the present application has the following advantages:

[0029] 1. The electric micro-mixing device based on asymmetric hole array provided by the present application utilizes the force of electric field to exert force on the input sample solution, thereby changing the original motion state of the fluid and promoting the occurrence of mixing.

[0030] 2. The electric micro-mixing device based on asymmetric hole array provided by the present application can obtain the desired mixing effect by changing the external voltage value.

[0031] 3. The electric micro-mixing device based on asymmetric hole array provided by the present application has high mixing efficiency, small use limitation and low required voltage value.

[0032] 4. The electric micro-mixing device based on asymmetric hole array provided by the present application has asymmetric micro-hole structure, small direct contact area between the electrode and the sample solution, and less solution pollution.

[0033] Based on the above reasons, the present application can be widely popularized in the field of microfluidics. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0035] Figure 1 The structure diagram of the electric micro-mixing device provided by the present application.

[0036] Figure 2 The top view of the electric micro-mixing device provided by the present application.

[0037] Figure 3 The partial schematic view of the electric micro-mixing device provided by the present application.

[0038] In the figure: 1, PDMS cover layer; 2, glass substrate layer; 3, first inlet; 4, second inlet; 5, first sample inlet channel; 6, second sample inlet channel; 7, first electrode plate; 8, second electrode plate; 9, first asymmetric micro-hole; 10, third electrode plate; 11, fourth electrode plate; 12, second asymmetric micro-hole; 13, fifth electrode plate; 14, sixth electrode plate; 15, third asymmetric micro-hole; 16, main micro-channel; 17, outlet. DETAILED DESCRIPTION

[0039] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The technical solutions of the embodiments of the present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0040] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0041] It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a presence of a feature, step, operation, device, component and / or combination thereof.

[0042] Unless specifically stated otherwise, the relative arrangement of the components and steps illustrated in these embodiments and the numerical expressions and values are not limiting of the scope of the present application. It should be understood that the dimensions of the various parts shown in the drawings are not necessarily to scale. Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as part of the description of the present application. In all examples shown and discussed herein, any specific value should be interpreted as merely an example, and not as a limitation. Thus, other examples of the exemplary embodiments can have different values. It should be noted that similar reference numbers and letters in the following drawings represent similar items, and therefore, once an item is defined in one drawing, it need not be discussed further in subsequent drawings.

[0043] In the description of the present application, it needs to be understood that the orientation words such as "front, back, up, down, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicated orientation or positional relationship is generally based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, without making the opposite statement, these orientation words do not indicate and imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the scope of protection of the present application: the orientation words "inner, outer" refer to the inner and outer relative to the contour of each component itself.

[0044] For the convenience of description, spatial relative terms such as "over", "above", "upper surface", "upper" and the like can be used herein to describe the spatial positional relationship of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawing is inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" the other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0045] In addition, it needs to be pointed out that the use of "first", "second" and the like to define parts is only for the convenience of distinguishing the corresponding parts, and the above words have no special meaning unless otherwise stated, therefore, it cannot be understood as a limitation on the scope of protection of the present application.

[0046] As shown in 1-3, the present application provides an electric micro-mixing device based on asymmetric hole array, comprising: a PDMS cover layer 1, a glass substrate layer 2, an electrode layer; wherein:

[0047] The PDMS cover layer 1 is used to form a micro-channel structure, including an inlet and outlet area, a channel area, and an asymmetric hole area;

[0048] The glass substrate layer 2 is bonded with the PDMS cover layer 1;

[0049] The electrode layer comprises a first electrode plate 7, a second electrode plate 8, a third electrode plate 10, a fourth electrode plate 11, a fifth electrode plate 13 and a sixth electrode plate 14.

[0050] In specific implementation, as a preferred embodiment of the present application, continue to refer to Figure 1 ,2 On the PDMS cover layer 1, the specific arrangement is as follows:

[0051] The inlet and outlet area includes the first inlet 3, the second inlet 4 and the outlet 17.

[0052] The channel area includes the first sample channel 5, the second sample channel 6 and the main microchannel 16.

[0053] The asymmetric hole area includes the first asymmetric microhole 9, the second asymmetric microhole 12 and the third asymmetric microhole 15.

[0054] In specific implementation, as a preferred embodiment of the present application, continuing to refer to Figure 1 、 2 In the electrode layer, the specific arrangement is as follows:

[0055] The first electrode plate 7 and the second electrode plate 8 are respectively embedded in the PDMS cover layer 1 and arranged on both sides of the first asymmetric microhole 9.

[0056] The third electrode plate 10 and the fourth electrode plate 11 are respectively embedded in the PDMS cover layer 1 and arranged on both sides of the second asymmetric microhole 12.

[0057] The fifth electrode plate 13 and the sixth electrode plate 14 are respectively embedded in the PDMS cover layer 1 and arranged on both sides of the third asymmetric microhole 15.

[0058] In specific implementation, as a preferred embodiment of the present application, continuing to refer to Figure 1 、 2 The first inlet 3 is connected with the main microchannel 16 through the first sample channel 5; the second inlet 4 is connected with the main microchannel 16 through the second sample channel 6; and the main microchannel 16 is connected with the outlet 17.

[0059] In specific implementation, as a preferred embodiment of the present application, the first electrode plate 7, the second electrode plate 8, the third electrode plate 10, the fourth electrode plate 11, the fifth electrode plate 13 and the sixth electrode plate 14 are connected with an external power supply.

[0060] In specific implementation, as a preferred embodiment of the present application, the first asymmetric microhole 9, the second asymmetric microhole 12 and the third asymmetric microhole 15 are arranged on both sides of the main microchannel near the inlet and respectively connected with the first electrode plate 7, the second electrode plate 8, the third electrode plate 10, the fourth electrode plate 11, the fifth electrode plate 13 and the sixth electrode plate 14.

[0061] In a specific implementation, as a preferred embodiment of the present application, the first electrode plate 7, the second electrode plate 8, the third electrode plate 10, the fourth electrode plate 11, the fifth electrode plate 13 and the sixth electrode plate 14 have the same structure and size.

[0062] In a specific implementation, as a preferred embodiment of the present application, as shown in FIG. 1, the first asymmetric micropore 9, the second asymmetric micropore 12 and the third asymmetric micropore 15 each include five groups of small holes and one group of large holes, and each group of small holes and each group of large holes are symmetrically arranged on both sides of the main microchannel 16 to form the first asymmetric micropore 9, the second asymmetric micropore 12 and the third asymmetric micropore 15, respectively. Figure 3

[0063] The present application also provides a microfluidic mixing method based on the above-mentioned asymmetric hole array-based electric micro-mixing device, comprising:

[0064] S1, injecting the solution to be mixed into the first inlet 3, and injecting another solution with different concentration into the second inlet 4, and the injection speed of the two inlets is the same;

[0065] S2, turning on the signal source, and applying an alternating signal to the first electrode plate 7, the third electrode plate 10 and the fifth electrode plate 13, and grounding the second electrode plate 8, the fourth electrode plate 11 and the sixth electrode plate 14; at the same time, observing the flow and mixing of the input sample on the main microchannel 10;

[0066] S3, adjusting the alternating signal applied to the first electrode plate 7, the third electrode plate 10 and the fifth electrode plate 13 until the desired mixing effect is obtained, and finally the mixed solution flows into the waste pool through the outlet.

[0067] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.​

Claims

1. An electrically powered micro-hybrid device based on an asymmetric aperture array, characterized in that, include: PDMS cover layer (1), glass substrate layer (2), electrode layer; wherein: The PDMS cover layer (1) is used to form a microchannel structure, including an inlet / outlet area, a channel area, and an asymmetric pore area; The glass substrate layer (2) is bonded to the PDMS cover layer (1); The electrode layer includes a first electrode plate (7), a second electrode plate (8), a third electrode plate (10), a fourth electrode plate (11), a fifth electrode plate (13), and a sixth electrode plate (14); The asymmetric aperture region includes a first asymmetric micropore (9), a second asymmetric micropore (12), and a third asymmetric micropore (15). The first asymmetric micropore (9), the second asymmetric micropore (12), and the third asymmetric micropore (15) are disposed on both sides of the main microchannel near the entrance, and an asymmetric electric field is provided through the asymmetric micropores on both sides. The first electrode plate (7) and the second electrode plate (8) are respectively embedded in the PDMS cover layer (1) and disposed on both sides of the first asymmetric micropore (9); The third electrode plate (10) and the fourth electrode plate (11) are respectively embedded in the PDMS cover layer (1) and disposed on both sides of the second asymmetric micropore (12); The fifth electrode plate (13) and the sixth electrode plate (14) are respectively embedded in the PDMS cover layer (1) and disposed on both sides of the third asymmetric micropore (15).

2. The electrically driven micro-hybrid device based on an asymmetric aperture array according to claim 1, characterized in that, The PDMS cover layer (1) is specifically configured as follows: The entrance / exit area includes a first entrance (3), a second entrance (4), and an exit (17); The channel area includes a first injection channel (5), a second injection channel (6), and a main microchannel (16).

3. The electrically driven micro-hybrid device based on an asymmetric aperture array according to claim 2, characterized in that, The first inlet (3) is connected to the main microchannel (16) through the first injection channel (5); the second inlet (4) is connected to the main microchannel (16) through the second injection channel (6); the main microchannel (16) is connected to the outlet (17).

4. The electrically driven micro-hybrid device based on an asymmetric aperture array according to claim 1, characterized in that, The first electrode plate (7), the second electrode plate (8), the third electrode plate (10), the fourth electrode plate (11), the fifth electrode plate (13), and the sixth electrode plate (14) are connected to an external power source.

5. The electrically driven micro-hybrid device based on an asymmetric aperture array according to claim 1, characterized in that, The first electrode plate (7), the second electrode plate (8), the third electrode plate (10), the fourth electrode plate (11), the fifth electrode plate (13), and the sixth electrode plate (14) have the same structure and size.

6. The electrically driven micro-hybrid device based on an asymmetric aperture array according to claim 1, characterized in that, The first asymmetric micropore (9), the second asymmetric micropore (12) and the third asymmetric micropore (15) each include five sets of small holes and one set of large holes. Each five sets of small holes and each set of large holes are symmetrically arranged on both sides of the main microchannel (16) to form the first asymmetric micropore (9), the second asymmetric micropore (12) and the third asymmetric micropore (15) respectively. The diameter of the small holes is 10 μm and the diameter of the large holes is 500 μm.

7. A microfluidic mixing method based on the electrodynamic micromixing device based on an asymmetric aperture array as described in any one of claims 1-6, characterized in that, include: S1. The mixed solution is injected into the first inlet (3), and another solution of different concentration is injected into the second inlet (4) at the same rate. S2. Turn on the signal source and apply AC signals to the first electrode plate (7), the third electrode plate (10), and the fifth electrode plate (13). The second electrode plate (8), the fourth electrode plate (11), and the sixth electrode plate (14) are grounded. At the same time, observe the flow and mixing of the input sample in the main microchannel (16). S3. Adjust the AC signal applied to the first electrode plate (7), the third electrode plate (10), and the fifth electrode plate (13) until the desired mixing effect is obtained.

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