KR20090093429A - Micro or Nanofluidic Chip having PDMS Thin Coated-NOA Channel and Manufacture Method Thereof - Google Patents

Abstract

A micro or nano fluid chip consisting of NOA channels including a thin PDMS layer and a manufacturing method of the same are provided to flow the fluid within the channel of the fluid chip as the capillary phenomena. A micro or nano fluid chip comprises a channel(103) and a thin PDMS layer(105). The channel is comprised of a NOA(norland optical adhesive). The thin PDMS layer is piled on the channel. The thin PDMS layer is finished with the oxygen plasma. A cover layer(107) is formed on the side of the thin PDMS layer. A SAM layer(self assembled monolayers, 104) is formed on the lower part of the thin PDMS layer.

Description

Micro or Nanofluidic Chip having PDMS Thin Coated-NOA Channel and Manufacture Method Thereof}

The present invention relates to a fluid chip including a channel layer on which a thin film PDMS layer is formed, and more particularly, to a micro or nano fluid chip including a thin film PDMS layer subjected to oxygen plasma treatment on a surface of a channel consisting of quinoa. It is about a method.

Micro or nanofluidic chips manufactured using microfluidics are chips containing micro or nanochannels. These fluid chips allow a small amount of fluid to flow through the microchannels, allowing various reactions and actions to take place on the chip, which had to go through many complex processes in a conventional laboratory. The fluid chip is also called a lab-a-chip.

More specifically, micro or nanofluidic chips are designed to automatically process the entire process of an experiment, such as sample injection, hybridization and detection, into one small chip, a breakthrough high-tech product that will eliminate flasks and test tubes in the future. Inside the fluid chip, a plurality of fine fluid grooves narrower than the hair are staggered.

Among the microfluidic chips, in particular, nanofluidic chips may be applied to various applications of nano biotechnology such as analysis, classification, and study of single molecule level of biomolecule materials.

One of many methods of manufacturing such a nanofluidic chip is to cover the cover layer after complex processes such as electron beam lithography and etching each time a channel is made. This method requires the use of high temperature and high pressure. it's difficult.

Therefore, recently, there is a method of covering a cover layer after preparing a micro or nano fluid channel layer through a process of forming a micro or nano channel pattern in a pre-formed master mold using a micro or nano imprinting technique. In this case, the cover layer may be formed on the channel layer by using a non-uniform deposition technique or by spin coating the adhesive layer on the cover layer.

However, in the non-uniform deposition technique, when the coating layer is deposited on the channel layer to form the cover layer, not only the channel size is reduced, but the reduced channel size is also non-uniform, which hinders fluid flow. In addition, in the method of spin-coating an adhesive layer on the cover layer, the adhesive layer of the cover layer flows into the channel layer to block a part of the channel layer, so that not only the channel size is different, but also the channel may be blocked, and thus the fluid may not flow.

Therefore, it is important that the fluid chip not only maintains the hydrophilicity essential for fluid flow for a long time while reducing the process required for the cover layer and the channel layer to be coupled, but also secures a channel space through which the fluid can flow.

Accordingly, the present invention provides a micro or nanofluidic chip including a channel layer formed by forming a thin film PDMS layer on a channel made of quinoa and subjected to oxygen plasma treatment, and a method of manufacturing the same.

The present invention also provides a micro or nanofluidic chip and a method of manufacturing the cover layer covering the channel layer can be used only by oxygen plasma treatment.

To this end, the micro or nanofluidic chip of the present invention includes a channel layer in which a PDMS layer of an oxygen plasma-treated thin film is laminated on a channel made of NOA, and a cover of the channel layer covered with oxygen plasma. It consists of a combination of layers.

In addition, the surface of the quinoa channel may be treated with an oxygen plasma to form a self-embedled monolayer (SAM) layer, and then a thin film PDMS layer may be formed.

In addition, the method of manufacturing a micro or nanofluidic chip of the present invention comprises the steps of forming a channel by pouring and curing the quinoa on the master mold, the step of thin film coating the top surface of the cured channel surface with PDMS, a thin film PDMS layer Treating the upper surface of the formed channel surface with oxygen plasma to form a channel layer, forming a cover layer treated with oxygen plasma, and combining the formed channel layer with the cover layer.

The method may further include forming an oxygen plasma and forming a SAM layer on an upper surface of the channel formed of quinoa.

The present invention maintains hydrophilicity for at least 30 days by the thin film PDMS layer treated with the oxygen plasma included in the channel layer, thereby allowing fluid to flow in the channel (fluid groove) of the fluid chip only by capillary phenomenon without external pressure.

In addition, the cover layer covering the channel layer is easily combined with the channel layer only by the oxygen plasma treatment by the thin film PDMS layer treated with the oxygen plasma coated on the quinoa channel, thereby simplifying the process.

In addition, the channel layer is hardened by the quinoa channel, so that when it is combined with the cover layer, there is no pushing phenomenon, thereby protecting the space in which the fluid flows inside the channel (fluid groove), resulting in defect or damage of the fluid chip. Not coming

1 is an explanatory diagram showing a manufacturing process of a micro or nanofluidic chip in which a thin film PDMS layer is formed.

Figure 2a is a picture of the PDMS channel layer, Figure 2b is a picture of the noah channel layer.

3 is a cross-sectional photograph of a micro or nano fluid chip manufactured by the method of FIG. 1.

Figure 4a is a photograph showing the hydrophilicity of the micro or nano-fluidic chip after one month manufactured by the method of FIG.

Figure 4b is a graph showing the contact angle between the channel layer, the bulk PDMS layer formed of the fluid chip manufactured by the method of Figure 1 and the contact angle between the water and water for a month.

* Description of the symbols for the main parts of the drawings *

100: fluid chip 101: master mold

102: Noah 103: the channel

104: sampling layer 105: thin film PDMS layer

106: channel layer 107: cover layer

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

The micro or nanofluidic chip of the present invention comprises a channel layer and a cover layer covering the channel layer.

The channel layer is composed of a channel made of NOA, a Self Assembled Monolayers (SAM) layer made of amino silane, and an oxygen plasma-treated poly (dimethylsiloxane) layer. In this case, the channel layer is formed with a fluid groove through which the fluid can flow, and the shape of the fluid groove may be any shape as long as the fluid can pass therethrough. In addition, the thin film PDMS layer treated with the oxygen plasma means oxygen plasma treatment on the PDMS layer surface.

The cover layer covers a side of the thin film PDMS layer treated with the oxygen plasma of the channel layer. In addition, the cover layer is a substrate treated with an oxygen plasma, wherein the substrate used is a glass plate, a silicon wafer, a plate made of PDMS, a plate coated with PDMS, or the like.

In addition, as a method of supplying hydroxyl group (OH) to a quinoa channel, a thin film PDMS layer, and a cover layer, UVO (UV with Oxygen), corona, etc. can be used.

Noah (NOA, product name of Norland products inc.) Forming the channel of the channel layer is a transparent, colorless, liquid photopolymerizable polymer compound of the acrylic polyurethane type, and can be cured by exposure to ultraviolet rays.

1 is an explanatory diagram showing a manufacturing process of a micro or nanofluidic chip in which a thin film PDMS layer is formed.

Referring to FIG. 1, the quinoa 102 is poured into a master mold 101 and then exposed to ultraviolet light for 1 hour to form a micro or nano sized hardened channel 103. Thereafter, the cured channel 103 is removed from the master mold 101 and again exposed for 12 hours under ultraviolet light to cure the secondary (FIG. 1A).

The oxygen plasma is treated on the surface of the cured quinoa channel 103. For example, oxygen plasma treatment is performed on the upper surface of the channel for 30 seconds under 25 W power, where the upper surface refers to the surface of the surface on which a plurality of fluid grooves are formed through which the fluid can flow. The conditions for treating the oxygen plasma are not limited to this, and may be any conditions as long as the surface can be treated.

Thereafter, the PDMS layer should be coated on the NOA channel surface 103 treated with the oxygen plasma. Generally, PDMS is excellent in non-adhesion with other materials. Therefore, if the PDMS is directly coated on the channel surface 103 formed of quinoa, defects may occur. Thus, the SAM layer 104 is included to increase the adhesion between the channel surface 103 treated with the oxygen plasma and the PDMS.

The process of forming the oxygen plasma treatment, the fountain layer formation, and the thin film PDMS layer which are sequentially performed on the quinoa channel surface 103 is as follows. Hydroxyl group (OH) generated by oxygen plasma treatment reacts with amino silane to form a spring layer in which an amino group is formed at the terminal, and the terminal amino group is reacted with PDMS to coat the PDMS by chemical bonding. To form.

In order to form the fountain layer 104, 0.5 wt% of an amino silane solution is applied to the surface of the oxygen plasma-treated channel to react the channel surface with the amino silane for 10 minutes. At this time, the amino silane is 3-aminopropyltriethoxysilane (3-aminopropyltriethoxysilane), 4-aminobutyltriethoxysilane (4-aminobutyltriethoxysilane), (aminoethylaminomethyl) phenethyltrimethoxysilane ((aminoethylaminomethyl) phenethyltrimethoxysilane ), N- (2-aminoethyl) -3-aminopropylsilanetriol, N- (2-aminoethyl) -3-aminopropylsilane triol, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (N- (2-aminoethyl) -3-aminopropyltrimethoxysilane), N- (2-aminoethyl) -3-aminopropyltriethoxysilane (N- (2-aminoethyl) -3-aminopropyltriethoxysilane), N- (6- Aminohexyl) aminomethyltrimethoxysilane (N- (6-aminohexyl) aminomethyl trimethoxysilane), N- (6-aminohexyl) aminopropyltrimethoxysilane (N- (6-aminohexyl) aminopropyltrimethoxysilane), N- (2- Amino ethyl) -11-amino undecyl trimethoxysilane (N- (2-aminoethyl) -11-aminoundecyl trimethoxysilane) etc. are used. For example, 0.5 wt% aqueous solution of 3-aminopropyltriethoxysilane is applied to the surface of the channel treated with oxygen plasma.

The channel surface treated up to the amino silane may be washed with distilled water since amino silane may not be present.

In this way, the PD layer (Mn = 5000) is dropped on the channel surface on which the fountain layer 104 is formed, and the PDMS coating layer 105 has a thickness of about 10 nm. For example, when the PDMS layer 105 of the thin film is reacted for 4 hours by dropping PDMS on the channel surface on which the fountain layer 104 is formed at 80 ° C., a coating layer having a thickness of about 8 nm to about 10 nm can be obtained. Thereafter, in order to remove the PDMS that has not reacted with the fountain layer 104, the channel 103 on which the PDMS layer 105 is formed is soaked in 2-propanol for 1 minute.

Coating PDMS with a thin film is to maintain hydrophilicity for a long time. The reason why the thin film PDMS coating maintains hydrophilicity for a long time is that the thickness of the PDMS layer, which is changed from hydrophobic to hydrophilic by oxygen plasma treatment on the upper surface of the PDMS layer, becomes tens or hundreds of nanometers below the surface of the PDMS layer. This is because a splitting does not occur in the chain of the polymer, and thus a polymer having a small molecular weight does not occur, thereby maintaining a hydrophilic PDMS layer. However, when the thickness of the PDMS is thick, when the surface of the PDMS, which has been changed to hydrophilic due to oxygen plasma treatment, has elapsed for a predetermined time, a crack occurs in the chain of PDMS polymer on the bottom of the coated PDMS. The small molecular weight polymer gradually diffuses toward the surface, thereby restoring the original hydrophobicity of the surface.

Therefore, when the thickness of the PDMS coating layer is changed to hydrophilic due to oxygen plasma treatment, it is likely to recover to its original hydrophobicity after a certain time or period. (B of FIG. 1)

In this way, the channel layer 106 is formed by sequentially performing an oxygen plasma treatment, a fountain layer 104, a thin film PDMS layer 105, and an oxygen plasma treatment on the channel 103 made of quinoa.

In addition to the channel layer 106, the cover layer 107 constituting the fluid chip 100 covers the channel layer 106 and performs oxygen plasma treatment on the surface of the substrate. Finally, the oxygen plasma treated channel layer 106 and the cover layer 107 are combined on a 60 ° C. hot plate prepared to promote the bonding of the two layers to complete the fluid chip 100. In this case, the substrate used as the cover layer 107 may be any one selected from a glass plate, a silicon wafer, a plate made of PDMS, and a plate coated with PDMS (FIG. 1C).

In this case, the channel layer 106 is due to the oxygen plasma-treated thin film PDMS layer Since the cover layer 107 can be easily bonded only by the oxygen plasma treatment, the fluid chip manufacturing process is simplified. In addition, since the channel layer 106 is not pushed when the cover layer 107 is covered by the strength of the quinoa channel 103, the channel layer 106 protects a space in which the fluid flows inside the channel so that the fluid chip is defective or damaged. Does not bring

FIG. 2 is a photograph of a PDMS channel layer and a photograph of a quinoa channel layer, and FIG. 3 is a cross-sectional photograph of a micro or nanofluidic chip manufactured by the method of FIG. 1.

FIG. 2A is a photograph of a channel layer formed of oxygen plasma treated PDMS, and FIG. 2B is a photograph of a channel layer formed of oxygen plasma treated NOA. 3 is a cross-sectional photograph of a fluid chip manufactured by the method of FIG. 1.

In general, the channel layer made of PDMS can be easily combined with a cover layer formed only by oxygen plasma treatment. However, as shown in the photograph of FIG. 2A, the PDMS cannot form a channel including a fluid groove properly, thereby causing a problem such as obstructing the flow of the fluid.

Figure 2b is a channel formed by using a quinoa instead of the difficult to form the PDMS channel as shown in the picture is formed accurately the shape of the channel including the fluid groove. However, the cover layer for covering the noah channel layer is difficult to be combined with the channel layer only by oxygen plasma treatment. Therefore, the cover layer is formed through a complex process such as spin coating and curing the toluene solution in which quinoa is dissolved on the film, thereby being combined with the channel layer.

Referring to FIG. 3, the channel layer is formed of a quinoa channel, and an oxygen plasma-treated thin film PDMS layer is formed on the upper surface of the channel layer, thereby being combined with the oxygen plasma-treated cover layer. The substrate used as the cover layer here is a silicon wafer.

The channel layer in which the thin film PDMS layer formed by the oxygen plasma treatment on the quinoa channel is easily combined with the cover layer formed only by the oxygen plasma treatment to reduce the process, and the phenomena do not occur when the cover layer is covered by the noah channel. .

Figure 4a is a photograph showing the hydrophilicity of the micro or nano-fluidic chip after one month manufactured by the method of FIG.

Referring to FIG. 4A, after the fluid chip is manufactured by the method of FIG. 1, the fluid chip flows through the fluid chip after a certain period of time (monthly), thereby confirming whether the fluid flows into the channel (fluid groove) only by capillary action without external pressure. It is a photograph.

In the picture, the fluid, that is, 100ug / ml of BSA-FITC aqueous solution showing green fluorescence, filled the inside of the fluid chip channel (fluid groove) of 500nm X 500nm size after a certain period of time without external pressure. This shows that the fluid chip maintains hydrophilicity after a certain period of time.

FIG. 4B is a graph illustrating a comparative measurement of a contact angle between a thin film PDMS surface and a bulk PDMS surface and water formed on the quinoa surface by the method of FIG. 1 for one month.

Referring to FIG. 4B, the contact angle between water and each surface is measured by dropping water before and after oxygen plasma treatment on the thin film PDMS surface and the bulk PDMS surface formed on the quinoa surface by the method of FIG. 1. .

1 and 7 days and 30 days after the oxygen plasma was applied to the PDMS thin film surface and the bulk PDMS surface formed on the quinoa surface before and immediately after the treatment, the water and each channel layer surface It is a figure which measured the contact angle. Herein, bulk PDMS means mm or cm thick PDMS pad.

The contact angle is said to be hydrophobic when the water and surface angle is more than 90 degrees, and the surface material is hydrophilic when the angle between water and surface is not more than 90 degrees.

Referring to the bar graph of FIG. 4B, it can be seen that the PDMS not treated with the oxygen plasma basically has hydrophobic properties. However, it can be seen from the graph that the surface of the thin film PDMS or the bulk PDMS surface has a hydrophilic property since the contact angle is less than 20 degrees after the oxygen plasma treatment.

In the graph, it can be seen that the bulk PDMS surface treated with oxygen plasma has a large contact angle over time, and thus, the contact angle is greater than 90 degrees and returned to hydrophobic properties from 7 days. However, it can be seen that the surface on which the oxygen plasma-treated thin film PDMS layer is formed is maintained in hydrophilicity since the contact angle does not exceed 90 degrees even after 30 days of manufacture. In this case, the period during which the hydrophilicity of the surface on which the thin film PDMS layer is formed is maintained is not limited to 30 days, and as shown in the graph, the contact angle is maintained not to exceed 50 degrees from 7 days to 30 days. The hydrophilicity can be maintained even if it becomes more than a day.

Therefore, the fluid chip having the PDMS layer of the oxygen plasma-treated thin film on the surface of the channel can maintain hydrophilicity for a long time, thereby allowing the fluid to flow into the channel (fluid groove) only by capillary action.

Claims (7)

A microfluidic or nanofluidic chip in which a thin layer of poly (dimethylsiloxane) (PDMS), which has been treated with oxygen plasma, is formed on a channel formed of a NOA. The micro or nanofluidic chip of claim 1, wherein a cover layer is formed on a side of the PDMS layer. The micro or nanofluidic chip of claim 1, wherein a SAM layer is formed under the thin film PDMS layer. The micro or nanofluidic chip of claim 2, wherein the cover layer is treated with an oxygen plasma. A method for manufacturing the micro or nanofluidic chip of claim 1, comprising forming a thin film PDMS layer in a quinoa channel and subjecting the thin film PDMS layer to oxygen plasma treatment. The method of claim 5, further comprising forming a fountain layer before forming the thin film PDMS layer. 7. The method of claim 6, further comprising performing an oxygen plasma treatment prior to forming the fountain layer.