KR101887554B1 - Method for bonding heterogeneous substrates for fabricating elastomer-plastic hybrid microdevices - Google Patents

Abstract

(A) oxidizing a surface of a first substrate made of a silicone-based material; (b) introducing an amino group to the surface of the oxidized first substrate; And (c) bringing the first substrate and the second substrate into contact with each other such that a surface of the first substrate on which the amino group is introduced and a surface of a second substrate made of thermoplastic are in contact with each other, According to the bonding method of the present invention, it is possible to use only one kind of chemical substance for modifying the surface of a substrate at the time of bonding between heterogeneous substrates, all processes can be performed at room temperature, Furthermore, since the final oxidation step, which is generally required for device bonding, can be omitted, large-area heterogeneous substrate bonding can be made simpler and quicker than in the prior art.

Description

≪ Desc / Clms Page number 1 > METHOD FOR BONDING HETEROGENEOUS SUBSTRATES FOR FABRICATING ELASTOMER-PLASTIC HYBRID MICRODEVICES FOR ELEVATOR-PLASTIC HYBRID MICRO DEVICES

The present invention relates to a method of joining heterogeneous substrates for micro device manufacture, and more particularly, to a method of joining a room temperature bonding between an elastomeric substrate and a plastic substrate.

As a final step in microdevice fabrication, surface oxidation, surface-chemical modification, sol-gel coating, and the like are performed to achieve faster, simpler and more robust sealing. Various methods such as chemical gluing, ultrasonic bonding and dual-cure dry adhesive bonding have been attempted.

These methods provide high bond strength, good long term hydrolytic stability, and room temperature bonding potential during some or all of the bonding process, but many types of chemical use and multi-step surface modification processes remain unresolved. have.

On the other hand, biomolecules such as antibodies, peptides, proteins and the like that are very sensitive to heat and susceptible to external stimuli must be encapsulated within the microstructure or encapsulated in the form of microarrays prior to sealing the microdevice have. Also, fragile structures such as optical fibers, waveguides, etc. need to be embedded in the microfluidic system before the entire microfluidic system is assembled.

Therefore, it is urgently necessary to develop a bonding method that allows bonding at room temperature throughout the entire process, but uses a single chemical for surface modification.

Among the conventional techniques related to this, there is a method of using thermoplastic resin (thermoplastic) alone, using poly [dimethylsiloxane-co- (3-aminopropyl) -methylsiloxane], which is a PDMS derivative having an amine side chain group as an amine-PDMS PDMS linker is first coated on the surface of the plastic through aminolysis at room temperature and then the amine PDMS linker is coated on the coated plastic substrate with the adhesive (PC), polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polyvinyl chloride (PVC) were prepared by oxidizing the PDMS substrate. , And polyimide (PI) could be permanently bonded to the PDMS.

In another conventional technique, a surface of a non-silicone substrate such as plastic, ceramics and metal is instantaneously modified with mercaptosilane through a nucleophilic reaction at room temperature, The substrates and PDMS were oxidized and then permanently bonded.

In order to form a strong siloxane bond (Si-O-Si), which is the main driving force for bonding, although only one chemical substance is used at the time of surface modification and coating is performed at room temperature, The final surface oxidation process was essential during the sealing process. However, this final surface oxidation process can have serious adverse effects when introducing certain chemical functional groups into the microchannel or fixing biomolecules prior to capping the microdevice.

Korean Patent Publication No. 10-2015-0104321 (Publication date: 2015.09.15) Korean Patent Publication No. 10-2014-0143514 (published on Dec. 17, 2014) Korean Patent Publication No. 10-2001-0071745 (published on November 19, 2001).

 V. Sunkara, D.-K. Park, H. Hwang, R. Chantiwas, S. A. Soper and Y.-K. Cho, Lab Chip, 2011, 11, 962-965.  Y. Suzuki, M. Yamada and M. Seki, Sens. Actuators, B, 2010, 148, 323-329.  N. Y. Lee and B. H. Chung, Langmuir, 2009, 25, 3861-3866.  T. Kasahara, S. Matsunami, T. Edura, J. Oshima, C. Adachi, S. Shoji and J. Mizuno, Sens. Actuators, A, 2013, 195, 219-223.  K. G. Lee, S. Shin, B. I. Kim, N. H. Bae, M.-K. Lee, S. J. Lee and T. J. Lee, Lab Chip, 2015, 15, 1412-1416.  F. Saharil, F. Forsberg, Y. Liu, P. Bettotti, N. Kumar, F. Niklaus, T. Haraldsson, W. van der Wijngaart and K. B. Gylfason, J. Micromech. Microeng., 2013, 23, 025021.  H.-W. Shim, J.-H. Lee, T.-S. Hwang, Y. W. Rhee, Y. M. Bae, J. S. Choi, J. Han and C.-S. Lee, Biosens. Bioelectron., 2007, 22, 3188-3195.  J. Wu and N. Y. Lee, Lab Chip, 2014, 14, 1564-1571.  W. Wu, J. Wu, J.-H. Kim and N. Y. Lee, Lab Chip, 2015, 15, 2819-2825.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems of the prior art, and it is an object of the present invention to provide a method of manufacturing a semiconductor device, The present invention aims at providing a heterogeneous substrate joining method capable of performing all the processes at room temperature and omitting the final oxidation step generally required for device joining.

According to an aspect of the present invention, there is provided a method of manufacturing a semiconductor device, including: (a) oxidizing a surface of a first substrate made of a silicone material; (b) introducing an amino group to the surface of the oxidized first substrate; And (c) bringing the first substrate and the second substrate into contact with each other such that a surface of the first substrate on which the amino group is introduced and a surface of a second substrate made of thermoplastic are in contact with each other, A bonding method is provided.

Also, in the step (a), the surface of the first substrate is treated with an oxygen plasma to form an oxide film on the surface of the substrate.

In the step (b), the oxidized first substrate is immersed in a solution containing amino silane to introduce an amino group onto the surface of the substrate.

Also, the aminosilane may be at least one selected from the group consisting of 3-aminopropyltriethoxysilane (APTES), 3-aminopropyltrimethoxysilane (APTMS), N- (6-aminohexyl) (APMES) and 3- (N, N-dimethyl) -aminopropyltrimethoxysilane (AEAPS), N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane Silane (DMAPS). The present invention also provides a method for bonding a different substrate.

Also, the first substrate may be made of PDMS (poly (dimethylsiloxane)).

Also, the steps (a) to (c) are performed at room temperature.

And a step of oxidizing the first substrate and the second substrate is not performed before the step (b) is completed and the step (c) is performed.

The second substrate may be formed of polycarbonate (PC), polyimide (PI), poly (methyl methacrylate) (PMMA), polystyrene (PS), or poly (ethylene terephthalate) Thereby providing a heterogeneous substrate bonding method.

And, in another aspect of the invention, the present invention provides a heterogeneous substrate assembly produced by the above method.

Further, in another aspect of the present invention, the present invention provides a microdevice including the above-described heterogeneous substrate junction.

According to the method for bonding a heterogeneous substrate according to the present invention, it is possible to use only one kind of chemical substance for modifying the surface of a substrate at the time of bonding between heterogeneous substrates, the whole process can be performed at room temperature, It is possible to omit the final oxidation step required for large-area heterogeneous substrate bonding, which is simpler and quicker than in the prior art.

Accordingly, the method for bonding a heterogeneous substrate according to the present invention is a method of encapsulating a biomolecule sensitive to an external stimulus such as heat or plasma treatment, and embedding a fragile substance before the bonding step Which is a very useful joining method.

In addition, the method for bonding a heterogeneous substrate according to the present invention can be effectively used for implementing a microdevice. In particular, a biomolecule-immobilized surface such as a DNA, an antibody, an enzyme, a peptide or a protein microarray Which is very useful in the stable construction of a closed microfluidic system.

1 (a) to 1 (d) are conceptual views schematically showing a bonding method according to the present embodiment. FIG. 1 (e) is a cross-sectional view of an APTES-coated PDMS surface and This is a conceptual diagram showing the reaction mechanism expected to occur between thermoplastic plastic substrate surfaces.
Figs. 2 (a) to 2 (d) each show a PDMS that is not surface-treated; O ₂ plasma-treated PDMS; APTES-coated PDMS; And water contact angle on TEOS-coated PDMS.
Figs. 3 (a) to 3 (c) each show a PDMS without pristine treatment; APTES-coated PDMS (magnification of N1s peak for insertivity); And X-ray photoelectron spectroscopy (XPS) analysis of the TEOS-coated PDMS surface.
4 is a graph showing the surface amine density on the surface of PDMS according to amine concentration changes (1, 2 and 5%) and reaction time changes (10, 20 and 30 min) standard curve).
Figures 5 (a) through 5 (e) are experimental set-ups for peel testing, respectively; Separation of PDMS-PC junctions; PDMS and PC surfaces after separation; Area of 9 cm ² and 100 cm ² Results of delamination tests performed on PDMS-PC junctions; And PDMS-PI conjugates having areas of 9 cm ² and 100 cm ² , respectively.
Figures 6 (a) - (d) show PDMS-PC junctions not bonded when PDMS is coated with TEOS; Non-bonded PDMS-PI conjugates when PDMS is coated with TEOS; Bonded PDMS-PC junction when PDMS is coated with APTES; 6 (e) and 6 (f) are photographs showing burst test results at a pressure of 95 psi. Fig. 6 (b) is a photograph of leakage test results obtained by varying the flow rate using a PDMS-PC micro device.
Figures 7 (a) - (d) show fluorescence signals emitted by carboxylate-functionalized fluorophore adsorbed on PDMS, respectively; Fluorescence signals emitted by amine-functionalized fluorophore adsorbed on PDMS; A fluorescent signal emitted by a carboxylate-functionalized fluorophore adsorbed on APTES-coated PDMS; And fluorescence signals emitted by amine-functionalized fluorophore adsorbed on APTES-coated PDMS. Fig. 7 (e) is a photograph showing fluorescence signals emitted by a glutaraldehyde (GA) FIG. 7 (f) is a conceptual diagram showing the attachment of an amine-functionalized fluorescent moiety onto the APTES-coated PDMS, and FIG. 7 (f) terminated fluorescence image of a fluorescent sphere.
Figure 8 (a) is a PDMS-PC microdevice photograph with three microchambers for performing parallel multiplex polymerase chain reaction (PCR); Figure 8 (b) is an infrared (IR) camera photograph for each of the three stages of thermal cycling; Figure 8 (c) is a graph showing the initial denaturation and the temperature profile in the first four cycles; Fig. 8 (d) shows multiplex PCR results using a PDMS-PC microdevice for the 101 bp fragment of the eaeA gene of E. coli O157 and the 183 bp fragment of the invA gene of S. typhimurium (lanes 1 and 2 are Lanes 3 to 5 represent multiplex PCR results using PDMS-PC microdevices, lane M represents 100 bp (negative control) and lanes 3 to 5 represent multiplex PCR results using a thermal cycler A DNA size marker); Fig. 8 (e) is a graph showing the relative intensity of the target amplicon shown in Fig. 8 (d).
FIGS. 9 (a) to 9 (e) are schematic diagrams showing a spatial immobilization process of DNA amplification products in a microchamber. FIGS. 9 (a) to 9 (e) are GA coatings on APTES coated PDMS; Spatial spotting of DNA amplification products functionalized with amines; Removal of unfixed DNA; SYBR Green I dye staining; And blue light illumination, and Fig. 9 (f) is a fluorescence image of the DNA amplification product located inside the micro chamber.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Embodiments in accordance with the concepts of the present invention can make various changes and have various forms, so that specific embodiments are illustrated in the drawings and described in detail in this specification or application. It should be understood, however, that the embodiments according to the concepts of the present invention are not intended to be limited to any particular mode of disclosure, but rather all variations, equivalents, and alternatives falling within the spirit and scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises ", or" having ", or the like, specify that there is a stated feature, number, step, operation, , Steps, operations, components, parts, or combinations thereof, as a matter of principle.

Hereinafter, the present invention will be described in detail.

The method of bonding a hetero-substrate according to the present invention comprises the steps of: (a) oxidizing a surface of a first substrate made of a silicon-based material; (b) introducing an amino group to the surface of the oxidized first substrate; And (c) bringing the first substrate and the second substrate into contact with each other so that the surface of the first substrate, on which the amino group is introduced, and the surface of the second substrate made of thermoplastic come into contact with each other.

In the step (a), an oxidation process is performed so that a functional group having reactivity is formed prior to the introduction of an amino group onto the surface of a first substrate made of a silicone material.

Preferably, in this step, the surface of the first substrate is treated with an oxygen plasma to form an oxide film on the surface of the substrate where a functional group having a reactivity such as a hydroxyl group is exposed.

The oxygen plasma treatment may be performed using various types of plasma generating devices such as a corona discharger, a plasma generator, and a plasma asher. And the like.

On the other hand, the kind of the silicon-based material forming the first substrate is not particularly limited, and may be, for example, poly (dimethylsiloxane) (PDMS).

Conventionally, microdevices have been made by applying MEMS (Microelectromechanical Systems) technology using hard materials such as glass and metal, but the microfluidic devices of the materials have disadvantages such as complicated manufacturing process and high cost, The microfluidic device is manufactured using a polymeric material as a material for forming a microfluidic device. The fabrication cost of the microfluidic device is low, so that it can be used for a single use, flexibility can be given, and soft lithography ) Process and mass production is possible. In particular, PDMS has been widely used as a material for microfluidic devices because it has various advantages such as lower cost, excellent processability through soft lithography, gas permeability, and high transparency.

Next, in step (b), an amino group is introduced to the surface of the oxidized first substrate so as to form a strong chemical bond at an interface with a second substrate to be described later.

A specific method for introducing an amino group to the surface of the first substrate in this step is not particularly limited, but it is preferable to immerse the substrate in a solution containing a silane group and an amino silane having an amino group (-OH) on the oxidized first substrate and the alkoxyl group (-OR) of the aminosilane on the oxidized first substrate through the spin coating process, Bonding (Si-O-Si) is formed, and an amine-terminated first substrate having an amine group introduced into its surface is formed.

The aminosilane is not particularly limited in its kind, and examples thereof include 3-aminopropyltriethoxysilane (APTES), 3-aminopropyltrimethoxysilane (APTMS), N- (6-aminohexyl) Aminopropyl-dimethylethoxysilane (APMES), 3- (N, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane (AEAPS) Dimethyl) -aminopropyltrimethoxysilane (DMAPS), and the like.

Finally, in the step (c), the surface of the first substrate, on which the amino group is introduced, and the surface of the second substrate made of thermoplastic are connected to each other through the steps (a) and (b) And the second substrate is brought into contact with each other to complete the heterogeneous substrate bonding body.

Unlike the prior art, the bonding step in this step can be carried out at room temperature immediately without oxidizing the surface of the first substrate having the amine group introduced therein and the surface of the second substrate made of the thermoplastic plastic, Thus, even if no subsequent oxidation and high temperature bonding is performed, a permanent rigid bond can be achieved between the dissimilar substrates.

Specifically, the amine functional group on the surface of the first substrate can attack a carbonate main backbone, carbonyl main skeleton, etc. forming a thermoplastic plastic to form a strong urethane linkage at room temperature As a result, the amine groups at the end of the first substrate react directly with the plastic through aminolysis and permanent solid bonding can be achieved even at room temperature.

Accordingly, the method of bonding a different substrate according to the present invention does not damage the original shape and profile of the microchannel formed before bonding, preserves the inherent light transmittance of the plastic substrate, as well as heat or plasma treatment plasma treatment, and the like, and is useful for encapsulating biomolecules sensitive to external stimuli and embedding fragile substances before the bonding step.

On the other hand, the second substrate is made of a known thermoplastic material, and the kind thereof is not particularly limited, and polycarbonate (PC), polyimide (PI), poly (methylmethacrylate) (PMMA), polystyrene (PS) or poly (ethylene terephthalate) (PET).

According to the method for bonding a heterogeneous substrate according to the present invention described above in detail, it is possible to use only one kind of chemical substance (aminosilane) for modifying the substrate surface at the time of bonding between heterogeneous substrates, Furthermore, since the final oxidation step, which is generally required for device bonding, can be omitted, large-area heterogeneous substrate bonding can be made simpler and quicker than in the prior art.

Accordingly, the method for bonding a heterogeneous substrate according to the present invention is a method of encapsulating a biomolecule sensitive to an external stimulus such as heat or plasma treatment, and embedding a fragile substance before the bonding step Which is a very useful joining method.

In addition, the method for bonding a heterogeneous substrate according to the present invention can be effectively used for implementing a microdevice. In particular, a biomolecule-immobilized surface such as a DNA, an antibody, an enzyme, a peptide or a protein microarray Which is very useful in the stable construction of a closed microfluidic system.

Hereinafter, the present invention will be described in detail by way of examples with reference to the drawings. However, the embodiments according to the present disclosure can be modified in various other forms, and the scope of the present specification is not construed as being limited to the embodiments described below. Embodiments of the present disclosure are provided to more fully describe the present disclosure to those of ordinary skill in the art.

<Examples>

1 (a) to 1 (d) are conceptual views schematically showing a joining method according to the embodiment of the present invention, and Fig. 1 (e) is a conceptual diagram showing a reaction mechanism for forming an urethane bond by reacting with an amine functional group of an APTES-coated PDMS and a carbonate or carbonyl group of a thermoplastic plastic substrate at the time of bonding by the above bonding method.

First, a PDMS prepolymer (Sylgard 184) and a curing agent were mixed at 10: 1 (w / w) and cured at 80 ° C for 30 minutes to prepare PDMS (FIG. Then, thermosetting PDMS (3 cm x 3 cm and 10 cm x 10 cm) was activated with an oxygen plasma (60 W) for 1 minute (Fig. 1B). Next, the substrate was immersed in an aqueous solution of 1% (v / v) 3-Aminopropyltriethoxysilane (APTES; ≥98.0%) at room temperature for 20 minutes PI thin film (thickness: 0.07 mm) (Fig. 1d). The PDMS substrate and the plastic substrate were maintained in contact with each other for 5 minutes under a load of 0.5 kg at room temperature. The two substrates contacted were bonded through the formation of urethane bonds at the interfacial interface, leaving the amine functionalities in the microchannels unreacted (Fig. 1e).

<Comparative Example>

A bonded body was prepared using the same process as in the above example, except that the PDMS substrate activated by oxygen plasma treatment was immersed in a 1% (v / v) TEOS (tetraethyl orthosilicate) aqueous solution.

Experimental Example 1 Measurement and Analysis of Water Contact Angle Change over Time for PDMS Substrates Treated in Examples and Comparative Examples

Figs. 2 (a) to 2 (d) each show a PDMS that is not surface-treated; O ₂ plasma-treated PDMS; APTES-coated PDMS; And water contact angle measurements on TEOS-coated PDMS.

The water contact angles for the untreated PDMS, oxygen plasma treated PDMS, APTES coated PDMS, and TEOS coated PMDS were about 100.8 ± 1.4 ° (FIG. 2a), <10 ° (FIG. 2b), 67.0 ± 2.8 ° (Figure 2c), and 30.1 ± 2.3 ° (Figure 2d).

As shown in Figures 2 (a) and 2 (b), the contact angle of PDMS decreased from 100.8 ° to less than 10 ° after plasma treatment and then increased to 67.0 ° after treatment with 1% APTES solution ), Indicating that the amine functional groups have been successfully produced as in the previous studies. (Fig. 2 (d)) shows a slight increase in the contact angle when treated with a 1% TEOS solution after the plasma treatment was attributable to the fact that the addition of the ethoxy group (-OC ₂ H ₅ ) of TEOS and the hydroxyl group (Si) -containing functional groups have been introduced onto the surface of the PDMS through the reaction between the silicon-containing functional groups. For reference, the major difference between the chemical structure of APTES and TEOS is the presence of an amine group (-NH ₂ ) in place of the ethoxy group.

Experimental Example 2 X-ray photoelectron spectroscopy (XPS) analysis on the surface of the PDMS substrate processed in Examples and Comparative Examples

Figs. 3 (a) to 3 (c) each show a PDMS without pristine treatment; APTES-coated PDMS (magnification of N1s peak for insertivity); And X-ray photoelectron spectroscopy (XPS) analysis of the TEOS-coated PDMS surface.

As shown in Fig. 3 (a), for PDMS, four element peaks of Si2p, Si2s, C1s, and O1s were detected at approximately 102, 151, 284, and 532 eV, respectively. The N1s peak was further generated at about 399 eV by the APTES coating (see also the inset in FIG. 3 (b) for an enlarged view), which confirms the successful introduction of the amine functionalities onto the PDMS surface. On the other hand, the intensity of the O1s peak was significantly increased by APTES and TEOS treatment, which seems to be due to the condensation of the hydroxyl groups of the oxidized PDMS surface with the ethoxy groups of APTES and TEOS. Thus, by the masking effect of these coatings, the Si2p, Si2s and C1s peak intensities of the modified specimens were reduced compared to the untreated specimens.

Experimental Example 3 Analysis of Amine Functional Quantification on the Surface of PDMS Substrate Treated in Examples and Comparative Examples

4 is a graph showing the surface amine density on the surface of PDMS according to amine concentration changes (1, 2 and 5%) and reaction time changes (10, 20 and 30 min) standard curve).

For reference, the molar concentration and the percentage concentration have the following relationship.

Molarity = [(% x d) / MW] x 10

(%) Is the percent concentration, d is the density (or specific gravity), MW is the molecular weight, 1% APTES corresponds to 42 mM ATPES)

As shown in the inset in FIG. 4, the fluorescence intensity of fluorescein-5-isothiocyanate (FITC) reacting with the primary amine on the PDMS substrate showed a strong correlation with the amine group concentration (R ² = 0.9968).

The density of amine groups increased until the concentration of APTES reached 5%. As shown in FIG. 4, the surface amine density increased until the reaction time reached 20 minutes, but decreased when the reaction time increased by 30 minutes. This was probably because the reaction time increased and the outermost layer of APTES became thicker It seems to be because the masking of the amine groups that can be done. This allows the amine groups to be less exposed to hydrolysis, thereby blocking the amine reaction with FITC. The amine group densities after reacting with 1, 2, and 5% APTES on oxidized PDMS for 20 minutes were 0.83 ± 0.04, 0.92 ± 0.05, and 1.35 ± 0.07 nmol cm ^-2 , respectively. The density of amine groups grafted onto PDMS was found to be higher than the density on the PMMA (0.29 ± 0.02 and 0.16 ± 0.01), but lower than the density on the glass surface. The amine density of 0.83 ± 0.04 nmol cm ^-2 was a fairly sufficient value for DNA fixation, so 1% APTES was finally selected for PDMS coating for bonding.

< Experimental Example  4> PDMS -PC conjugates and PDMS Peel and delamination tests of the PI conjugate

Figures 5 (a) through 5 (e) are experimental set-ups for peel testing, respectively; Separation of PDMS-PC junctions; PDMS and PC surfaces after separation; Area of 9 cm ² and 100 cm ² Results of delamination tests performed on PDMS-PC junctions; And a PDMS-PI conjugate having an area of 9 cm ² and 100 cm ² , respectively.

The average bond strength of the PDMS-PC junction was 409 ± 6.6 kPa. The remaining PDMS attached ruptured on the PC (2 x 2 cm) confirms that a permanent bond has been established between the APTES coated PDMS and the PC (see Fig. 5 (c)). These bond strengths are described by Sunkara et al. And the bond strengths reported by Wu et al. (528 and 428.5 kPa, respectively), it is necessary to consider that this embodiment was carried out at room temperature rather than 80 ° C. Furthermore, it has been shown that the strength obtained by the previous method performed at room temperature is higher than the strength obtained by other methods, and in particular, this embodiment is achieved through a much simpler and faster process. For this reason, other joining methods according to the present invention require a specific type of device that requires cell patterning and experimental conditions of relatively low pressure (~ 35 kPa), or a microdevice that must withstand pressures of 125 to 300 kPa It can be considered as a promising alternative to the existing methods in case of intergration of the electrodes.

Figures 5 (d) and 5 (e) show the peel test results for the junctions of different areas (9 cm ² (3 × 3 cm) and 100 cm ² (10 × 10 cm)). Specifically, when PDMS is oxidized by plasma treatment to form a hydroxyl group on the surface, these hydroxyl groups react with the ethoxy group of APTES to form amine-terminated PDMS. These amine functionalities, together with the carbonate backbones of some plastics such as PC and PI, form a chemically stable urethane or urethane derivative bond, resulting in a rigid bond.

Figures 6 (a) - (c) illustrate the results of a delamination test, showing that when PDMS is coated with TEOS, unbonded PDMS-PC conjugates; Non-bonded PDMS-PI conjugates when PDMS is coated with TEOS; This is a photograph showing a bonded PDMS-PC junction when PDMS is coated with APTES.

When PDMS is treated with 1% TEOS aqueous solution instead of APTES, the PDMS pieces are completely peeled off from the plastic substrate without rupturing (see FIGS. 6 (a) and 6 (b)). On the other hand, only a physical contact for 5 minutes resulted in a permanent bond between the APTES coated PDMS and the untreated PC (see Fig. 6 (c)). The rapid and robust bonding between the dissimilar substrates at low temperatures confirms the superiority of the bonding method according to the present invention.

Experimental Example 5 Leakage and Burst Tests of PDMS-PC Conjugate and PDMS-PI Conjugate

6 (e) and 6 (f) show the burst test results obtained at a pressure of 95 psi. Fig. 6 (d) shows leakage test results performed at various flow rates within the PDMS- It is a photograph.

No leakage occurred when the per-minute injection volume per minute was tested at a flow rate (7000 μL min ^-1 ) that was 2000 times the total internal volume of the microchannels used in the experiment . For the PDMS-PC conjugate, the maximum pressure recorded after three repetitions of the burst test reached approximately 95 psi (655 kPa). At this high pressure, the silicone tube connected to the inlet was expanded (see Fig. 6 (e)), but the junction maintained its integrity and the red ink flowing into the microchannel immediately after the burst test did not leak (See Fig. 6 (f)). These results have confirmed the potential for conjugation methods for high pressure experiments in a wide range of applications, including droplet-based microfluidics, blood plasma separation, and the like.

Experimental Example 6 Experimental and Analysis of Selective Immobilization of Fluorescent Sphere in Microchannel

In most bonding processes, surface oxidation is required at the final stage of device bonding. Surface oxidation can eliminate the surface amine functionalities introduced in the surface modification process. For example, as a result of measuring the change in water contact angle after the oxygen plasma treatment of the amine-coated PDMS, the surface of the hydrophilic surface due to disappearance of the amine functional group on the surface after the oxygen plasma treatment, , Respectively. However, in the absence of oxygen plasma treatment, amine-terminated PDMS maintained the amine-coated state in the absence of external stimulation for 60 days, which is a highly desirable phenomenon in applications requiring stable surface properties, Method can be used. Biomolecules often need to be immobilized within microchannels, and many biomolecules contain amines and carboxyls because they are proteins. For this reason, the amine coated surface has great advantages in fixing biomolecules inside the microchannel.

Since the bonding method according to the present invention does not require an oxidation step and a high temperature condition in the final step, the bonding can be completed only by capping the plastic on the amine-coated PDMS at room temperature, It is particularly advantageous to immobilize biomolecules sensitive to heat and external stimuli such as cells, proteins, peptides, enzymes, antibodies and the like before sealing the device. Occasionally, biomolecules must be immobilized at spatially defined locations, not entire microchannels. However, if a conventional surface coating method is used for biomolecule fixing, the entire inner wall of the microchannel can be completely coated, so that the coated area can not be controlled. To solve this problem, some existing researchers have adopted a micro-contacting technique for the purpose of realizing a spatial coating of a target biomolecule, but the contact-printed region Which must be protected against damage during the device sealing process.

However, with the bonding method according to the present invention, it is possible to directly place the chemical or biomolecule solution for surface functionalization only at specific points or regions where fixation is required before sealing the microdevice.

The bonding method according to the present invention is not limited to the above-described application fields, and can exhibit a great advantage when the microstructure, which is easily damaged by physical damage such as an optical fiber or a waveguide, is surrounded before the device is sealed. The experiment and analysis were carried out as follows.

Figures 7 (a) - (d) show fluorescence signals emitted by carboxylate-functionalized fluorophore adsorbed on PDMS, respectively; Fluorescence signals emitted by amine-functionalized fluorophore adsorbed on PDMS; A fluorescent signal emitted by a carboxylate-functionalized fluorophore adsorbed on APTES-coated PDMS; And fluorescence signals emitted by amine-functionalized fluorophore adsorbed on APTES-coated PDMS. Fig. 7 (e) is a photograph showing fluorescence signals emitted by a glutaraldehyde (GA) FIG. 7 (f) is a conceptual diagram showing the attachment of an amine-functionalized fluorescent moiety onto the APTES-coated PDMS, and FIG. 7 (f) terminated fluorescence image of a fluorescent sphere.

As shown in Figs. 7 (a) and (b), almost no fluorescence was detected when PDMS was not coated with APTES. However, when APTES-coated PDMS is used, the carboxylate-functionalized fluorescent moiety is successfully immobilized through the covalent bond between the carboxyl group (-COOH) of the fluorescent moiety and the amine functional group of the coated PDMS, (See Fig. 7 (c)). This bond between the carboxylate-functionalized fluorophore and the amine-functionalized channel wall causes the N- [3- (dimethylamino) propyl] -N'-ethylcarbodiimide hydrochloride (EDC) N-Hydroxysulfosuccinimide (NHS; 98.5%) buffer. A further step of treating amine coated PDMS with 25 wt% aqueous glutaraldehyde (GA) solution resulted in the reaction of the GA with the amine group of the fluorophore, resulting in the attachment of the functionalized fluorescent dye to the amine. In fact, it is known that amine groups and aldehyde groups crosslink. Figure 7 (d) shows that strong red fluorescence is generated by the amine-functionalized fluorophore adsorbed on the APTES coated PDMS.

7 (e), the GA coating also forms a Schiff base bond between the aldehyde group of the GA and the amine group of the fluorophore modified with amine functionalized PDMS and amine to form APTES coating &lt; RTI ID = 0.0 &gt;Lt; RTI ID = 0.0 &gt; PDMS. &Lt; / RTI &gt; It was confirmed by the strong red fluorescence that the PDMS and plastic microchannel walls were successfully adhered to the amine functionalized fluorophore (see Fig. 7 (f)). This finding is very noteworthy in that the use of amine end species for surface modification requires fewer steps than the use of carboxylate end species. As described above, an EDC / NHS reaction is required to activate the carboxylate functionality, which can be cumbersome compared to using a GA coating. Another advantage is that all four internal microchannel walls can be tuned to have the same surface properties, because APTES coated PDMS can be coated with GA and reacted with amine-terminated fluorophore. Thus, all four walls can be modified to have amine functionalities. On the other hand, it was confirmed that the GA coating does not affect the PC surface.

<Experimental Example 7> Thermal stability test and analysis of PDMS-PC micro device

Figures 8 (a) and 8 (b) show the temperature measured using a chamber-type reactor made using a PDMS-PC microdevice and an infrared (IR) camera. At this time, three microchambers were formed on the PDMS side through replica molding and were used to simultaneously perform three sets of multiplex PCR. The temperature was precisely controlled to perform multiple PCR using the micro chamber, and was measured over the first 20 minutes after initiation of amplification (see FIG. 8 (c)). The mean temperatures during denaturation, annealing and extension stages were 95.1 ± 0.26 ° C, 48.3 ± 0.3 ° C, and 72.2 ± 0.28 ° C, respectively, and the coefficient of variation (CV) ) Values were 0.3% (n = 10), 0.6% (n = 10), and 0.4% (n = 10), respectively. From these results, it can be seen that the heat transmitted through the PC has a very uniform distribution and relatively low variability.

Since the PC has a relatively low thermal conductivity (0.19-0.22 WK ^-1 m ^-1, at 23 ° C), the entire surface temperature of the PC substrate reaches 95.0 ± 0.18 ° C at 31.0 ± 0.06 ° C after about 1 minute The denaturation was carried out at 105 ° C for 60 seconds, annealing at 48 ° C for 45 seconds, Followed by 30 cycles of extension at 79 DEG C for 50 seconds.

Experimental Example 8 Experiments and Analysis of Multiplex Polymerase Chain Reaction (PCR) Using PDMS-PC Microdevice

Fig. 8 (d) shows multiplex PCR results of E. coli O157 eaeA gene (183 bp) and S. typhimurium invA gene (101 bp). The negative control (lane 1) and the positive control (lane 2) were analyzed using a conventional thermal cycler. Lanes 3 to 5 show multiplex PCR results using PDMS-PC microdevices. The mean intensities of the amplicons obtained using microdevices were 14-28% and 18-27%, respectively, as compared to the positive control for E. coli O157: H7 and S. typhimurium (see FIG. 8 (e)). Multiplex PCR has been successfully performed. From this, it was confirmed that it is possible to simultaneously detect a large number of pathogens in an economical manner and monitor them in real time by using the junction method according to the present invention. Due to the high thermal stability provided by the bonding by the present method, the device sustained a continuous thermal cycling for about two hours without leaking. These results confirmed the applicability and potential of the bonded device by this method in applications requiring high pressure and high temperature conditions.

Experimental Example 9 Direct Detection of PCR Amplification Products in a Microchamber of PDMS-PC Microdevice

To identify the advantages of the conjugation method according to the invention in site-specific fixation, a 153 bp PCR (5'-terminal) functionalized with an amine group using an amine-tagged primer The amplification product was immobilized on the PDMS surface treated with GA (see Fig. 9).

FIGS. 9 (a) to 9 (e) are schematic diagrams showing a spatial immobilization process of DNA amplification products in a microchamber. FIGS. 9 (a) to 9 (e) are GA coatings on APTES coated PDMS; Spatial spotting of DNA amplification products functionalized with amines; Removal of unfixed DNA; SYBR Green I dye staining; And blue light illumination, and Fig. 9 (f) is a fluorescence image of the DNA amplification product located inside the micro chamber.

Specifically, a microchamber-engraved PDMS substrate was first treated with 1% APTES and then the bottom of the microchamber was coated with a solution in which 2.5% GA was dissolved in 100 mM Na ₃ PO ₄ buffer (pH 7.0) (See Fig. 9 (a)). After holding at room temperature for 30 minutes, the GA was rinsed 3 times from the surface using Na ₃ PO ₄ buffer (pH 7.0), and then the microchamber was sealed with a PC slab of the same size, A few drops (0.2 μL) of the amine-functionalized DNA diluted with 100 mM Na ₃ PO ₄ buffer (pH 7.0) were added to a predetermined area of the surface treated with GA (see FIG. 9 (b)) . After holding in a humidified chamber for 2 hours at 30 ° C to immobilize the DNA target, the microchamber was washed with distilled water and then 5 × SSC buffer / 0.1% Tween 20 was added to remove the unfixed DNA , And incubation was carried out for 15 minutes using the same (Fig. 9 (c)). Finally, the micro chamber was again washed with distilled water and the dye (SYBR Green I dye) was colored (see Fig. 9 (d)). An image of a DNA spot was photographed under a blue light source (497 nm) (see Figure 9 (e)). As shown in Figure 9 (f), through the fluorescent signal, It was confirmed that the target was successfully fixed at a specific position on the micro chamber surface.

EXPERIMENTAL EXAMPLE 10 Optical Encapsulation Experiment in Microchannel of PDMS-PC Microdevice

An optical fiber (diameter 200 μm) was encapsulated in the microchannel of the PDMS-PC microdevice using the bonding method according to the present invention. The outer coat layer and the cladding layer, which serve as physical protections for the glass core in the optical fiber, were removed before encapsulation. When the outer coat layer and the cladding layer are removed as described above, the optical fiber is extremely sensitive to external pressure such as temperature and pressure at the time of encapsulation. When the room temperature bonding method according to the present invention is used, the two substrates are subjected to a conformal contact ). The stability of the encapsulated optical fiber was confirmed by passing white light through the optical fiber, and physical damage to the optical fiber occurred when heat and pressure were applied.

Claims (10)

(a) oxidizing a first substrate surface made of a silicon-based material;
(b) treating the surface of the oxidized first substrate with aminosilane to introduce an amino group to the surface of the first substrate through a siloxane bond (Si-O-Si); And
(c) bringing the first substrate and the second substrate into contact with each other so that the surface of the first substrate on which the amino group is introduced and the surface of the second substrate formed of a thermoplastic thermoplastic having a carbonate group or a carbonyl group are in contact with each other, Bonding the first substrate surface and the second substrate surface via urethane bonding,
Wherein the step of oxidizing the first substrate and the second substrate is not performed before the step (b) is completed and the step (c) is performed. The method according to claim 1,
Wherein the oxide film is formed on the surface of the substrate by treating the surface of the first substrate with oxygen plasma in the step (a). The method according to claim 1,
Wherein the oxidized first substrate is immersed in a solution containing amino silane in step (b) to introduce an amino group onto the surface of the substrate. The method of claim 3,
Aminopropyltriethoxysilane (APTES), 3-aminopropyltrimethoxysilane (APTMS), N- (6-aminohexyl) -3-aminopropyltrimethoxysilane (AHAPS), N - (2-aminoethyl) -3-aminopropylmethyldimethoxysilane (AEAPS), 3-aminopropyl-dimethylethoxysilane (APMES) and 3- (N, DMAPS). &Lt; / RTI &gt; The method according to claim 1,
Wherein the first substrate is made of PDMS (poly (dimethylsiloxane)). The method according to claim 1,
Wherein the steps (a) to (c) are performed at room temperature. delete The method according to claim 1,
Characterized in that the second substrate is made of polycarbonate (PC), polyimide (PI), poly (methyl methacrylate) (PMMA), polystyrene (PS) or poly (ethylene terephthalate) Bonding method. A heterogeneous substrate assembly produced by the method of any one of claims 1 to 6 and 8. A microdevice comprising a heterogeneous substrate junction of claim 9.

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