JP2002283293A - Microfluid control device and method of manufacturing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microfluid control device easy in changing a pattern such as a forming groove, capable of shortening a work process, requiring no completely disposable form by a reason for pollution, the easily reproduceable to reuse a base board. SOLUTION: This microfluid control device 8 is composed of the base board 1, a resin layer 2 on the base board, and a resin coat 7 on the resin layer, and forms a fluid circuit 5 on the resin layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a so-called μ-TA
The present invention relates to a microfluidic device that realizes S (micro / fine total analysis system) and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, in various fields such as genetic research and criminal investigation, it is necessary to develop a small-sized device and a highly sensitive detection method for analyzing components of trace fluids such as DNA and toxic substances. Sex is growing. Therefore,
A micro-TAS (Micro / Miniaturiz) that integrates micro flow channels, sampling units, filters, columns, detectors, etc. on a substrate and creates a chemical analysis system for analyzing components such as fluids by micromachining technology
ed Total Analysis System)
Is attracting attention. In high-precision analysis using a small amount of sample, there are many deficiencies in the most widely used spectroscopic analysis methods such as fluorescence analysis at present, and no advantage in terms of detection sensitivity is reported even if the size is reduced. However, μ-TAS
It can be expected that measurement can be performed with a small amount of sample or reagent.

[0003] In the medical field, various proteins, including counting of the number of red blood cells and white blood cells, are currently being used.
Ultimately, very expensive and large-scale biochemical analyzers are used to measure various parameters such as hormones and antigen-antibody, but by applying μ-TAS, such analysis and measurement can be performed. Inexpensive, rapid, and highly sensitive methods are being studied. Further, by using μ-TAS, replacement of parts and the like can be simplified, there is no need to worry about infection in blood analysis, and it is expected to contribute to the development of hygiene in the medical field. In addition, it is expected to play an active role in the field of genetic information (DNA) analysis, which is being studied most actively in the United States. One of the ultimate goals is to decode all human DNA, determine the cause of intractable disease at the genetic level, and perform treatments tailored to the individual. One of the goals is to perform the genetic decoding at the individual level quickly and accurately. , Μ−
TAS technology is expected. In the system itself, the μ-TAS can also enable miniaturization, cost reduction, reduction of ineffective volume, and the like. In addition, the amount of samples and reagents required for measurement can be significantly reduced, and the amount of waste liquid generated in analysis can be reduced. As described above, applications and further developments are expected in various fields due to the large number of advantages.

[0004]

SUMMARY OF THE INVENTION Such a μ-TAS
In the prior art, there has been proposed a device in which a miniaturized combination of a flow path, an analysis unit, a detection unit, and the like is fixed to a substrate. In such a conventional μ-TAS, the entire system must be washed each time the μ-TAS is used once. In particular, in the medical field and analysis of genetic information, the μ-TAS must be disposable. However, such μ-T
AS itself is an expensive fine system, and it is desired to develop a system and an apparatus that do not have to be all disposable.
Therefore, an object of the present invention is to provide a method for reusing and reusing a contaminated material without disposable for each measurement analysis.
An object is to provide a microfluidic device that enables TAS. It is a further object of the present invention to provide a method for manufacturing a microfluidic device which can be easily applied to a μ-TAS system in which such reproduction and reuse are easy.

[0005]

The above objects of the present invention have been attained by the following means. In the present invention, a channel (a groove) or the like, which is a component of the μ-TAS, is processed using a laser. That is, the present invention provides (1) a microfluidic device comprising: a substrate; a resin layer on the substrate; and a resin coat covering the resin layer, wherein a fluid circuit is formed in the resin layer.
(2) The microfluidic device according to (1), wherein the substrate is selected from silicon, glass or ceramics, and (3) a groove in which the fluid circuit has at least a portion of the substrate surface formed by laser processing and having a bottom as a bottom surface. (1) The microfluidic device according to (1), wherein the fluid circuit is formed by coating a resin layer including the groove with a laminate resin. (5) A resin layer is formed on a substrate, and the resin layer is removed by laser processing to form a groove having a predetermined pattern serving as a fluid flow path. A method of manufacturing a microfluidic device, in which a fluid circuit is formed by laminating the entire surface of the subsequent resin layer with a resin coat; (6) washing the resin layer and the resin coat on the substrate to reuse the substrate; (5) The method for manufacturing a microfluidic device according to (5), (7) optical analysis is performed by irradiating light from the side opposite to the fluid circuit forming surface on the substrate of the microfluidic device. (1) An analysis method using the microfluidic device according to (1), and (8) an analysis method using the microfluidic device according to (1), in which electric wiring is provided on the substrate and electrochemical analysis is performed. Is what you do. The microfluidic device in the present invention is the above-mentioned μ-TA
It is used for S.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a method for manufacturing a microfluidic device according to the present invention will be described with reference to the drawings. FIG. 1 shows a manufacturing process of a microfluidic device according to the present invention using μ-TAS as an example. FIG. 1A shows a substrate 1 made of silicon or the like, and FIG. 2B shows a resin layer 2 made of
1 shows a resin layer forming substrate 3 before processing on which is applied. Figure (c)
FIG. 3 is a perspective view showing a laser processing step, in which the resin layer forming substrate 3 is processed by a laser beam 4 to form a flow path 5. The method of forming the flow path 5 with the laser light 4 is not particularly limited, and may be adapted to a circuit pattern (groove width, depth, circuit shape) to be formed as a laser light source. There are a method of performing scanning exposure, a method of fixing the laser light source, and moving the substrate 3 with respect to the laser light so that a pattern suitable for a target circuit is formed. By this laser processing, the entrance, distribution section,
A flow path 5 that forms a mixing / reaction section, an analysis section, a storage section, a detection section, an outlet, and the like is formed. The difference in the shape depending on the location of the flow path 5 in FIG. 9C corresponds to the shape of the flow path for each purpose. Thus, the resin flow path forming substrate 6 is formed.

Next, as shown in FIG. 1D, a laminate 7 is applied to the upper surface of the substrate having the flow path 5, and a microfluidic device 8 is manufactured by covering all the components. In the present invention, as the substrate, in addition to inorganic materials such as silicon, glass (quartz glass), ceramics, and metal, Teflon (trade name, polytetrafluoroethylene) and other plastics are used. In the case where analysis or the like is performed by irradiating light from the side (lower surface) opposite to the circuit forming surface of the microfluidic device in FIG. The thickness of the substrate is not particularly limited, but is preferably in the range of 0.1 to 5 mm, more preferably 0.4 to 1 mm.

The thickness of the resin layer applied on the substrate is not particularly limited, but is preferably 10 to 1000 μm, more preferably 20 to 50 μm. The thickness of the resin layer is determined depending on the type to be measured, the amount of the sample required for the measurement, and the like. If the thickness is too large, laser processing is difficult. If the thickness is too small, fluid such as a sample liquid does not flow. Any resin may be used as long as it is easy to apply on the substrate by spin coating or lamination, and does not react with or elute with the analysis sample. For ease of replacement and replacement, a resin that can be easily washed off after use is preferable. By using such a resin, it is not necessary to throw away everything, and the silicon substrate can be reused.

The resin may be any resin as long as it satisfies the above-mentioned conditions, and examples thereof include a benzocyclobutene resin (BCB) and a fluororesin such as Teflon. The thickness of the resin layer 2 and the depth of the groove of the flow path 5 are usually the same. However, the resin may be partially left depending on the function of a certain part of the flow path circuit. In the case of performing optical measurement, there is no problem even if the resin partially remains as long as the wavelength is equal to or less than the wavelength of the measurement light. Processing for forming the flow path in the resin layer is preferably performed by laser processing. The laser is preferably an ultraviolet laser. Processing with ultraviolet light enables processing with little thermal effect. In machining, etc., precise processing is difficult due to distortion or damage due to heat, but due to processing using ultraviolet laser, less heat is generated,
A decrease in accuracy due to heat of the workpiece can be suppressed. Further, the light condensing property of the laser largely depends on the wavelength. The shorter the wavelength, the better the light condensing property. Therefore, it can be used for precision processing and fine processing that require high accuracy. In addition, the fact that heat is hardly generated enables processing into a material such as resin which is weak to heat. Among such ultraviolet laser light, a preferable ultraviolet laser light has a wavelength of 350 nm or less, and more preferably 150 nm or less.
３００300 nm.

In the present invention, when processing is performed with ultraviolet laser light, it is considered that grooves are formed by a laser ablation phenomenon. This mechanism is considered as follows. When an ultraviolet laser is applied to a polymer material, the molecular bonds are broken and the polymer is evaporated. (A) When a polymer material is first irradiated with an ultraviolet laser having a wavelength of 250 nm or the like for several tens of ns, (b) excited molecules and various active species are generated at a high density on the surface of the polymer material. (C) If the energy received by the molecule from the laser is greater than the chemical bonds that make up the molecule (if it exceeds the processing threshold, which is a material-specific value), the chemical bond is broken and the molecule is broken Decomposed to the atomic or atomic level. Therefore, rapid volume expansion occurs. (D) At this time, the excessively applied energy becomes the kinetic energy of the molecules, and the molecules are ejected to an open space above the workpiece to be removed.

After the formation of the flow channel, the laminating process is performed as described above. There are several types of laminating methods themselves, and any method may be used. As a specific example, in the case of lamination of a plastic film, extrusion lamination, dry lamination, and wet lamination are typical. Laminate 7
The thickness is to cover the upper surface of the resin layer formed by the resin coating, completely seal the upper surface of the flow path, and to give the microfluidic device sufficient strength to form a fluid circuit of a predetermined pattern. I just need. The thickness of such a laminate is usually 10 to 200 μm, preferably 20 to 1 μm.
00 μm. The microfluidic device of the present invention includes various known μ-TASs as described in the related art section.
It can be applied to Some examples of the detection method used therein will be described. 1) Electrochemical detection method From the viewpoint of integrating a chemical system on a single substrate, detection is also integrated on the substrate, which is suitable for the present invention. The microelectrode can be easily formed on a substrate by using micromachining technology, does not require a light source, and can be one of ideal detection methods for microchemical systems. 2) Chemiluminescence method In the detection method using chemiluminescence, since the reaction system itself emits light, there is no need for an external light source such as a laser or a complicated optical system such as a microscope. Good. Therefore, it is one of the ideal detection methods for integration like a microelectrode. 3) Electrochemiluminescence method In the electrochemiluminescence method, chemiluminescence can be controlled by applying a voltage to an electrode, so that a simple and highly reliable result can be obtained.

The microfluidic device of the present invention can be returned to the original silicon substrate by washing the resin layer with a solvent.

Next, the present invention will be described in more detail with reference to examples. Reference Example 1 In order to determine a laser condition capable of processing only a 30 μm thick BCB resin portion applied on a silicon substrate, 1.1 mJ, 2.1 mJ, 3.5 mJ, and 5.5 m per shot were obtained.
Under each laser output condition of J, 1.00 mm / s,
0.75mm / s, 0.50mm / s, 0.25mm /
The sample was moved and processed at a speed of s. FIG. 2 is a graph showing the relationship between the processing sample moving speed v and the groove depth d at each of the obtained laser outputs. When a cross section of the processed portion processed at each moving speed v at a laser output of 5.5 mJ / shot was observed with a micrograph, it reached the silicon substrate when v = 0.50 mm / s in processing at a laser output of 5.5 mJ. It can be seen that processing has been completed just before. But,
In the case of v = 0.25 mm / s in (d), the influence of the laser clearly appears on the silicon substrate in the vicinity of the deepest part of the processed portion, and it is considered that the silicon substrate is damaged. In such a case, the silicon substrate may be processed at a moving speed smaller than v = 0.25 mm so as not to be damaged.

Example 1 A microfluidic device of the present invention was manufactured according to the steps shown in FIG. 30 μm thick on a 380 μm thick silicon substrate
Was formed by spin coating. A substrate 6 (shown in FIG. 1 (c)) was formed by forming a flow path in the coated resin portion with an ultraviolet laser in a range of 30 μm width and 30 μm depth. Next, this substrate was laminated with a fluororesin to a thickness of 30 μm, and the whole was covered to form a microfluidic device. Example 2 10 on a quartz substrate having a thickness of 380 μm as shown in FIG.
Then, a gold vapor-deposited electrode 11 as shown in FIG. 3B was provided, and a BCB resin film 12 was applied thereon by spin coating to a thickness of 25 μm using the substrate as a substrate. This state is shown in FIG.
It was shown to. This resin film was processed with a 250 nm ultraviolet laser at a pulse energy of 10 mJ at 10 shots / sec to form a groove 13 having a width of 50 μm and a depth of 25 μm.
This state is shown in FIG. Next, a 30 μm-thick fluororesin laminate (not shown) was applied to the PCB resin film after laser processing in the same manner as in Example 1 to cover all the components. When a fluid sample is caused to flow through the fluid circuit including the grooves 13 thus formed, the gold vapor-deposited electrodes intersect with the grooves, so that the fluid sample between the electrodes can be subjected to electrochemical analysis. FIG. 4 is a drawing in which a microphotograph (magnification: 50 times) of another example of the microfluidic device incorporating the electrode formed by such a method as viewed from the quartz substrate (transparent) side is directly copied. . In the figure, 20 is a groove, 21 is an electrode, and 22 is a pad. There is a quartz substrate on the front side of the drawing paper.

[0014]

The microfluidic device of the present invention is widely used as a substrate in recent years and uses a silicon substrate or the like which is inexpensive and a resin is applied on the substrate by spin coating to form a resin portion. By doing so, it is possible to reduce the cost and simplify the cleaning and replacement. Further, the used resin portion can be washed off. Thereby, it is not necessary to throw away everything, and the substrate can be reused. If this microfluidic device is used, μ-TAS can be more easily put to practical use. Furthermore, since this microfluidic device forms a flow path in the resin layer, it is possible to change a pattern such as a groove to be formed, shorten a processing step, and prototype a fluid system on a chip quickly and easily. Further, there is an advantage that the range of selection of a processing target (eg, resin) is widened. Furthermore, since the material is hardly affected by heat by using an ultraviolet laser, there is an excellent effect that precision and fine processing can be performed, and the material can be used for a material which is weak to heat.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one example of a manufacturing process of a microfluidic device of the present invention.

FIG. 2 is a graph showing a relationship between a moving speed of a laser beam and a groove depth in laser processing used in the manufacturing method of the present invention.

FIG. 3 is an explanatory view showing one example of a manufacturing process of the microfluidic device of the present invention when a gold vapor deposition electrode is formed on a substrate.

FIG. 4 is an explanatory view of an enlarged photograph of a groove formed in an electrode and a resin portion as viewed from the back side of a quartz substrate of a microfluidic device as a preferred embodiment of the present invention.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Resin layer 4 Laser beam 5 Fluid circuit 7 Laminate 8 Microfluidic device 10 Quartz substrate 11 Gold vapor deposition electrode 12 BCB resin film 13 Groove 20 Groove 21 Electrode 22 Pad

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G01N 37/00 101 G01N 37/00 101 // B29C 59/16 B29C 59/16 F term (reference) 2G042 FB02 HA02 HA03 2G058 AA09 CC05 CC19 DA07 EA03 EA05 EA11 EA19 FA07 FB01 FB14 GA01 GA11 GA20 4F209 AH33 PA15 PB01 PC03 PG05 PG14 PW31 4G075 AA02 AA30 AA39 AA65 BC10 BD09 BD15 CA13 CA32 CA36 DA02 EB50 EB04 EB21 FB31

Claims (8)

[Claims] 1. A microfluidic device comprising: a substrate; a resin layer on the substrate; and a resin coat covering the resin layer, wherein a fluid circuit is formed in the resin layer. 2. The microfluidic device according to claim 1, wherein the substrate is selected from silicon, glass and ceramics. 3. The microfluidic device according to claim 1, wherein the fluid circuit is formed by a groove having at least a part of the substrate surface formed by laser processing and having a bottom as a bottom. 4. The microfluidic device according to claim 3, wherein the fluid circuit is formed by coating the resin layer including the groove with a laminating resin. 5. A resin layer is formed on a substrate, the resin layer is removed by laser processing to form a groove having a predetermined pattern serving as a fluid flow path, and the entire surface of the resin layer after the processing is formed. A microfluidic device by laminating the substrate with a resin coat to form a fluid circuit. 6. The method according to claim 5, wherein the resin layer and the resin coat on the substrate are washed away and the substrate is reused. 7. The analysis method using a microfluidic device according to claim 1, wherein the optical analysis is performed by irradiating the microfluidic device with light from the side opposite to the fluid circuit forming surface side on the substrate. 8. The analysis method using the microfluidic device according to claim 1, wherein an electric wiring is provided on the substrate and electrochemical analysis is performed.