A microfluidic chip containing a superhydrophobic structure and a preparation method thereof

Abstract

The present invention provides a microfluidic chip containing a superhydrophobic structure, which belongs to the technical field of microfluidic chips. The superhydrophobic structure is arranged in a hydrophobic area to realize a superhydrophobic function. The superhydrophobic structure is a surface micron array or nanoarray with a special shape prepared above an insulating layer. The present invention also provides a method for preparing a microfluidic chip containing a superhydrophobic structure, which adopts a two-photon three-dimensional lithography device to prepare a surface micron array or nanoarray with a special shape above an insulating layer. The microfluidic chip containing a superhydrophobic structure and the preparation method thereof of the present invention avoid the method of using imported fluorine-containing hydrophobic materials in the prior art, can be completely domestically produced, and is no longer affected by international trade factors. At the same time, it also saves procurement and process costs, is of great significance, and has a wider applicability.

Description

Technical Field

[0001] The invention belongs to the technical field of microfluidic chips and relates to a microfluidic chip containing a super-hydrophobic structure and a preparation method thereof. Background Art

[0002] Microfluidics is a scientific technology that precisely controls and manipulates microscale fluids, primarily at the micro- and nanoscale. It has the ability to miniaturize basic laboratory functions in biology and chemistry, such as sample preparation, reaction, separation, and detection, onto a chip a few square centimeters. Its fundamental characteristic and greatest advantage lies in the flexible combination and large-scale integration of multiple unit technologies on a microscopic, controllable platform. It is an interdisciplinary field encompassing engineering, physics, chemistry, microfabrication, and bioengineering. To ensure the smooth and continuous movement of microfluidics on a chip, the chip surface must be superhydrophobic, and achieving this surface quality has become a key technology in this field.

[0003] In the existing technology, a layer of fluorine-containing hydrophobic material is usually coated on the surface of the chip, for example, Cytop (a non-crystalline, highly transparent fluorine-containing polymer, Cytop is the trade name, the corresponding material name is perfluoro (1-butenyl vinylether) polymer). However, this fluorine-containing hydrophobic material is imported and has not yet been domestically produced. It is subject to export controls by the country of origin, resulting in high procurement costs. In addition, the process of preparing the super-hydrophobic film is complex, and the labor and time costs are high.

[0004] Therefore, there is an urgent need to study a pioneering method to integrate the preparation process of superhydrophobic structures into the wafer production process of microfluidic chips, so as to reduce production costs and improve efficiency, while also achieving full localization and no longer being affected by international trade factors. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a microfluidic chip containing a superhydrophobic structure and a preparation method thereof, using a two-photon three-dimensional lithography device to prepare a surface micron array or nanoarray with a specific shape above the insulating layer, so that it can achieve both insulation function and superhydrophobic function.

[0006] To achieve the above object, the present invention provides a microfluidic chip containing a super-hydrophobic structure, wherein the chip range is divided into a droplet-driven effective area and an ineffective area, wherein the hydrophobic area includes the entire range of the droplet-driven effective area and a portion of the ineffective area, and the other portion of the ineffective area is the peripheral area of ​​the chip;

[0007] A droplet driving electrode array is provided in the droplet driving effective area for driving the flow of droplets, and a superhydrophobic structure is provided in the hydrophobic area to realize the superhydrophobic function. The superhydrophobic structure is a surface micron array or nano array with a special shape prepared above the insulating layer to realize both insulation and superhydrophobic functions.

[0008] Furthermore, the super-hydrophobic structure is a "T"-shaped surface micro-array or nano-array.

[0009] Furthermore, the superhydrophobic structure is a "T"-shaped surface micron array, the overall height of the unit "T" shape is H is 1um, the "cap" diameter D1 is 1um, the "cap" height H1 is 0.3um, the pillar diameter D2 is 0.4um, the pillar height H2 is 0.7um, and the distance D3 between adjacent "caps" is 1um.

[0010] Furthermore, the material of the surface micro-array or nano-array with a special shape is photoresist.

[0011] Furthermore, the range of the surface microarray or nanoarray of special shape is the range of the hydrophobic area.

[0012] The present invention also provides a method for preparing the microfluidic chip containing the super-hydrophobic structure as described above, characterized in that it comprises the following steps:

[0013] A driving circuit, the droplet driving electrode array and an insulating layer are sequentially manufactured on a chip substrate;

[0014] A two-photon three-dimensional lithography device is used to prepare a surface micrometer array or nanometer array of special shape on the insulating layer.

[0015] Furthermore, a two-photon three-dimensional lithography device is used to prepare a surface micrometer array or nanometer array of a special shape on the insulating layer:

[0016] coating a layer of photoresist on the insulating layer;

[0017] Importing a preset special-shaped three-dimensional structure array design into a two-photon three-dimensional lithography device, and using the two-photon three-dimensional lithography device to perform photolithography curing on the photoresist;

[0018] Cleaning removes the photoresist that has not been cured by photolithography.

[0019] Furthermore, the photoresist that has not been photocured is removed by wet method using a stripping solution.

[0020] Furthermore, the special-shaped surface micro-array or nano-array is a T-shaped surface micro-array or nano-array, and the special-shaped three-dimensional structure array design drawing is a T-shaped three-dimensional structure array design drawing.

[0021] Further, it is characterized in that the surface micron array or nano array in the shape of a "T", the overall height H of the unit "T" shape is 1um, the "cap" diameter D1 is 1um, the "cap" height H1 is 0.3um, the pillar diameter D2 is 0.4um, the pillar height H2 is 0.7um, and the distance D3 between adjacent "caps" is 1um.

[0022] The advantages of the present invention using the above technical solution are:

[0023] The microfluidic chip containing a superhydrophobic structure and the preparation method thereof of the present invention use two-photon three-dimensional lithography equipment to prepare a surface micron array or nanoarray with a specific shape above an insulating layer to achieve a superhydrophobic function; the preparation process of the superhydrophobic structure is integrated into the chip flow process of the microfluidic chip, which not only reduces costs but also improves efficiency; avoids the use of imported fluorine-containing hydrophobic materials in the prior art, can fully achieve localization, is no longer affected by international trade factors, and also saves procurement and process costs, which is of great significance and has wider applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 Schematic diagram of the range division of the microfluidic chip containing a super-hydrophobic structure of the present invention;

[0026] Figure 2 A schematic structural diagram of a "T"-shaped surface microarray or nanoarray according to an embodiment of the present invention;

[0027] Figure 3 Schematic diagram of the process flow of preparing a surface micro-array or nano-array with a specific shape on an insulating layer using a two-photon three-dimensional lithography device in the present invention;

[0028] Explanation of the accompanying figures: 1-chip; 2-droplet driving effective area 2; 3-inactive area; 4-hydrophobic area; 11-chip substrate; 12-driving circuit; 21-the droplet driving electrode array; 22-insulating layer; 23-photoresist; 24-graphic photoresist layer. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] The present invention provides a microfluidic chip containing a super-hydrophobic structure, such as Figure 1 As shown, the chip 1 is divided into a droplet driving active area 2 and an inactive area 3, the hydrophobic area 4 includes the entire droplet driving active area 2 and a portion of the inactive area 3, and the other portion of the inactive area 3 is the peripheral area of ​​the chip 1;

[0031] A droplet driving electrode array 21 is provided in the droplet driving effective area 2 for driving the flow of droplets, and a super-hydrophobic structure is provided in the hydrophobic area 4 to realize the super-hydrophobic function. The super-hydrophobic structure is prepared above the insulating layer above the droplet driving electrode array 21, and is a surface micro-array or nano-array with a specific shape, realizing both insulation and super-hydrophobic functions.

[0032] Wherein, the super hydrophobic structure is a surface micron array or nano array of a special shape, such as a surface micron array or nano array of a "T" shape. Figure 2 As shown, the research is based on the surface hydrophobic structures of lotus leaves, butterfly wings, water strider feet, etc. in nature, which is a bionic technology. When the super-hydrophobic structure is a "T"-shaped surface micron array, the overall height H of the unit "T" shape can be designed to be 1um, the "cap" diameter D1 is 1um, the "cap" height H1 is 0.3um, the pillar diameter D2 is 0.4um, the pillar height H2 is 0.7um, and the distance D3 between adjacent "caps" is 1um. The range of the surface micron array or nano array with a special shape needs to be controlled to be the range of the hydrophobic area. In some embodiments, the material of the surface micron array or nano array with a special shape is photoresist.

[0033] The present invention also provides a method for preparing the microfluidic chip containing the super-hydrophobic structure as described above, comprising the following steps:

[0034] The driving circuit 12, the droplet driving electrode array 21 and the insulating layer 22 are sequentially manufactured on the chip substrate 11;

[0035] A two-photon three-dimensional lithography device is used to prepare a surface micrometer array or nanometer array of a special shape on the insulating layer 22 .

[0036] Furthermore, a schematic diagram of the process of preparing a surface micron array or nanometer array of a special shape on the insulating layer 22 using a two-photon three-dimensional lithography device is shown in FIG3 :

[0037] Coating a layer of photoresist 23 on the insulating layer 22;

[0038] Importing a preset special-shaped three-dimensional structure array design into a two-photon three-dimensional lithography device, and using the two-photon three-dimensional lithography device to perform photolithography curing on the photoresist 23;

[0039] The photoresist that has not been cured by photolithography is removed by cleaning to obtain a surface micron array or nanometer array 24 of a special shape. The photoresist that has not been cured by photolithography can be removed by a wet method using a stripping solution according to actual conditions.

[0040] In some embodiments, the special-shaped surface micro-array or nano-array 24 is a T-shaped surface micro-array or nano-array, and the special-shaped three-dimensional structure array design drawing is a T-shaped three-dimensional structure array design drawing. Of course, it can also be designed into other shapes such as a honeycomb array, a grid array, a micro-pillar array, etc., in which case a corresponding three-dimensional structure array design drawing is designed. For the "T"-shaped surface micro-array or nano-array, for example, the overall height H of the unit "T" shape can be designed to be 1um, the "cap" diameter D1 can be 1um, the "cap" height H1 can be 0.3um, the pillar diameter D2 can be 0.4um, the pillar height H2 can be 0.7um, and the distance D3 between adjacent "caps" can be 1um.

[0041] The advantages of the present invention using the above technical solution are:

[0042] The microfluidic chip containing a superhydrophobic structure and the preparation method thereof of the present invention use two-photon three-dimensional lithography equipment to prepare a surface micron array or nanoarray with a specific shape above an insulating layer to achieve a superhydrophobic function; the preparation process of the superhydrophobic structure is integrated into the chip flow process of the microfluidic chip, which not only reduces costs but also improves efficiency; avoids the use of imported fluorine-containing hydrophobic materials in the prior art, can fully achieve localization, is no longer affected by international trade factors, and also saves procurement and process costs, which is of great significance and has wider applicability.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A microfluidic chip containing a superhydrophobic structure, characterized in that: Dividing the chip into a droplet driving effective area and an ineffective area, wherein the hydrophobic area includes the entire droplet driving effective area and a portion of the ineffective area, and the other portion of the ineffective area is the peripheral area of ​​the chip; A droplet driving electrode array is provided in the droplet driving effective area for driving the droplet flow, and a super-hydrophobic structure is provided in the hydrophobic area to achieve a super-hydrophobic function. The super-hydrophobic structure is a surface micro-array or nano-array with a special shape prepared above the insulating layer to achieve both insulating and super-hydrophobic functions. The super-hydrophobic structure is a "T"-shaped surface micron array or nano array. The super-hydrophobic structure is a "T"-shaped surface micron array. The overall height of the unit "T" shape is H, which is 1um. The "cap" diameter D1 is 1um. The "cap" height H1 is 0.3um. The pillar diameter D2 is 0.4um. The pillar height H2 is 0.7um. The distance D3 between adjacent "caps" is 1um. The material of the special-shaped surface micron array or nano array is photoresist.

2. A method for preparing a microfluidic chip containing a super-hydrophobic structure as claimed in claim 1, characterized in that: The following steps are involved: A driving circuit, the droplet driving electrode array and an insulating layer are sequentially manufactured on a chip substrate; A two-photon three-dimensional lithography device is used to prepare a surface micrometer array or nanometer array of special shape on the insulating layer.

3. The preparation method according to claim 2, characterized in that Two-photon three-dimensional lithography equipment is used to prepare surface micro-arrays or nano-arrays of special shapes on top of the insulating layer: coating a layer of photoresist on the insulating layer; Importing a preset special-shaped three-dimensional structure array design into a two-photon three-dimensional lithography device, and using the two-photon three-dimensional lithography device to perform photolithography curing on the photoresist; Cleaning removes the photoresist that has not been cured by photolithography.

4. The preparation method according to claim 2, characterized in that The photoresist that has not been cured by photolithography is removed by wet method using a stripping solution.

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