Abstract:
The present invention relates to a microchannel chip capable of preventing fluid leakage caused by a lamination defect. Bottomed first regions, second regions, and third regions are formed by joining a film to a lower surface of the chip main body of a microchannel chip. The third regions are in communication with the second regions and are formed on carbon inks. The third regions are formed wider than the carbon inks are. The third regions are filled with an electroconductive adhesive.

Description:
TECHNICAL FIELD 
     The present invention relates to a fluid handling apparatus used for analysis, treatment or the like of a liquid sample and a fluid handling system including the same. 
     BACKGROUND ART 
     In recent years, micro-analytical systems are used to carry out an inspection/analysis of trace substances such as proteins and nucleic acids (e.g., DNA) accurately and at high speed in the scientific field such as biochemistry and analytical chemistry or in the medical field. 
     As an example of the micro-analytical system, there is a system which fills a channel formed on a micro-channel chip with a buffer solution, injects a sample through an injection port connected to the channel, applies a voltage to both ends of the channel and electrophoreses the sample to conduct an analysis. 
     The micro-channel chip is manufactured by joining a film (thin film) or thin plate to a chip body in which the channel is formed. A reservoir into which a liquid is injected is formed at both ends of the channel, and an electrode is formed in each reservoir. As an example of an electrode forming method, a method in which an electrode pattern is printed on a film or thin plate with a carbon ink is known (see PTL 1). One end of the electrode pattern formed in this manner is formed so as to be located inside the reservoir and the other end thereof is formed so as to be located outside the reservoir. The micro-channel chip is configured so that the electrode of the electrophoresis apparatus is made to contact the other end of the electrode pattern and a voltage can be applied to the liquid sample without contacting the liquid sample injected into the reservoir. 
     CITATION LIST 
     Patent Literature 
     PTL 1 
     U.S. Pat. No. 6,939,451 
     SUMMARY OF INVENTION 
     Technical Problem 
     According to the above electrode forming method, the periphery of the carbon ink layer in the film or thin plate may remain unbonded (insufficiently laminated) to the chip body due to the thickness of the carbon ink, and thus, the liquid may leak. 
     However, the background art adopts no measures for this liquid leakage, and the liquid leakage may cause contamination of the electrophoresis apparatus (electrode). 
     It is an object of the present invention to provide a fluid handling apparatus and a fluid handling system capable of preventing a liquid from leaking from the fluid handling apparatus such as a micro-channel chip and preventing contamination of an external environment. 
     Solution to Problem 
     According to an aspect of the present invention, there is provided a fluid handling apparatus including: a substrate member where a groove or a through hole is formed; a cover member that is bonded to one surface of the substrate member and has a thin film shape or a thin plate shape; and a transfer function section that is formed in a laminated shape to cover a part of a surface of the cover member on the side of the substrate member and transfers electricity or heat, wherein a groove or a through hole that forms a first region is formed in a portion of the substrate member corresponding to one end of the transfer function section, an opening of the groove or the through hole that forms the first region on the side of the cover member is closed by the cover member, a second region that communicates with an outside is formed in a portion of the substrate member corresponding to the other end of the transfer function section, the transfer function section electrically or thermally connects the first region and the second region to each other, a groove that forms a third region is formed in a portion of the substrate member corresponding to a portion between one end and the other end of the transfer function section to extend over edges of the transfer function section, an opening of the groove that forms the third region on the side of the cover member is closed by the cover member, and the third region communicates with the second region and is filled with an adhesive. 
     According to another aspect of the present invention, there is provided a fluid handling system including the fluid handling apparatus. 
     Advantageous Effects of Invention 
     According to the present invention, the groove is formed in the substrate member, and a space (third region) formed by closing the groove with the thin film or thin plate is filled with the adhesive. Accordingly, it is possible to prevent leakage of a liquid leaked through a gap between the substrate member and the cover member produced due to the thickness of the transfer function section of the laminated shape, and to prevent contamination of an external environment. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1A  to  FIG. 1D  are diagrams illustrating the shape of a micro-channel chip according to an embodiment of the present invention; 
         FIG. 2A  to  FIG. 2D  are diagrams illustrating the shape of a chip body of the micro-channel chip shown in  FIG. 1A  to  FIG. 1D ; 
         FIG. 3A  to  FIG. 3C  are diagrams illustrating the shape of a film after carbon ink printing of the micro-channel chip shown in  FIG. 1  to  FIG. 1D ; 
         FIG. 4  is an enlarged cross-sectional view along line E-E in  FIG. 1A ; 
         FIG. 5A  to  FIG. 5C  are diagrams illustrating the shape of a micro-channel chip according to an embodiment of the present invention (variation 1); and 
         FIG. 6A  to  FIG. 6C  are diagrams illustrating the shape of a chip body of the micro-channel chip shown in  FIG. 5A  to  FIG. 5C . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 
     Configuration of Micro-Channel Chip 
       FIG. 1A  to  FIG. 1D  are diagrams illustrating the shape of a micro-channel chip as a fluid handling apparatus according to the present embodiment.  FIG. 1A  is a plan view,  FIG. 1B  is a front cross-sectional view along line A-A,  FIG. 1C  is a bottom view, and  FIG. 1D  is a left side cross-sectional view along line B-B.  FIG. 1A  and  FIG. 1B  also show electrode rods  1   a  and  1   b  together. 
     As shown in  FIG. 1A  to  FIG. 1D , micro-channel chip  10  includes transparent chip body (substrate member)  12  that is an approximately rectangular flat plate, film (cover member)  14 , and carbon inks (electrodes as transfer function sections)  16   a  and  16   b.    
     The thickness of chip body  12  is approximately 1 mm, the thickness of film  14  is approximately 100 μm, and the thickness of carbon inks  16   a  and  16   b  is approximately 10 μm. 
     Chip body  12  and film  14  are formed of a resin material such as polyethylene terephthalate, polycarbonate, polymethylmethacrylate, vinyl chloride, polypropylene, polyether or polyethylene. Different materials may also be used for chip body  12  and film  14 . 
     Carbon inks  16   a  and  16   b  are printed on film  14 . Film  14  is bonded to chip body  12  by adhesion using an organic adhesive or thermo compression bonding. 
       FIG. 2A  to  FIG. 2D  are diagrams illustrating the shape of chip body  12 .  FIG. 2A  is a plan view,  FIG. 2B  is a front cross-sectional view along line C-C,  FIG. 2C  is a bottom view, and  FIG. 2D  is a left side cross-sectional view along line D-D. 
     Elongated micro-groove  22  is formed on undersurface  21  of chip body  12 , which is a surface that faces film  14 . Micro-groove  22  has a substantially rectangular cross section having a length (width and depth) per side of the order of several tens of micrometers. In a state where chip body  12  and film  14  are bonded together, channel  22 ′ is formed as the opening of micro-groove  22  is closed by film  14 . 
     Through holes  23   a  and  23   b  which are open outward, having an approximately circular cross section are formed at both ends of each micro-groove  22  of chip body  12 . The diameter of through holes  23   a  and  23   b  is several hundreds of micrometers to several millimeters. In a state where chip body  12  and film  14  are bonded together, bottomed first regions  23   a ′ and  23   b ′ having functions as an injection port and an exhaust port of a buffer solution and a sample are formed as openings of through holes  23   a  and  23   b  are closed by film  14 . 
     Through holes  24   a  and  24   b  having an approximately circular cross section are formed in chip body  12 . The diameter of through holes  24   a  and  24   b  is several hundreds of micrometers to several millimeters. In a state where chip body  12  and film  14  are bonded together, bottomed second regions  24   a ′ and  24   b ′ having a function of insertion ports of electrode rods  1   a  and  1   b  are formed as openings of through holes  24   a  and  24   b  are closed by film  14 . 
     On undersurface  21  of chip body  12 , groove  25   a  is formed in connection to through hole  24   a  at a position on carbon ink  16   a , and groove  25   b  is formed in connection to through hole  24   b  at a position on carbon ink  16   b . In a state where chip body  12  and film  14  are bonded together, third regions  25   a ′ and  25   b ′ are formed as openings of grooves  25   a  and  25   b  are closed by film  14 . Third regions  25   a ′ and  25   b ′ are located on carbon inks  16   a  and  16   b . The width of third regions  25   a ′ and  25   b ′ is formed so as to be greater than the width of carbon inks  16   a  and  16   b  (see  FIG. 4 ). Third regions  25   a ′ and  25   b ′ are filled with conductive adhesives  26   a  and  26   b  (see  FIG. 1  and  FIG. 4 ). Thus, it is possible to prevent unbonded portions of chip body  12  and film  14  generated by the thickness of carbon inks  16   a  and  16   b  from becoming unexpected channels, to prevent a liquid leaked from first regions  23   a ′ and  23   b ′ from reaching second regions  24   a ′ and  24   b′.    
       FIG. 3A  to  FIG. 3C  are diagrams illustrating the shape of film  14  after printing of carbon inks  16   a  and  16   b .  FIG. 3A  is a plan view,  FIG. 3B  is a front view, and  FIG. 3C  is a left side view. 
     Film  14  with carbon inks  16   a  and  16   b  printed thereon is bonded to undersurface  21  of chip body  12  through adhesion using a transparent organic adhesive, thermo compression bonding or the like so as to cover at least micro-groove  22 , through holes  23   a ,  23   b ,  24   a  and  24   b  and grooves  25   a  and  25   b.    
     When film  14  is bonded to chip body  12 , both ends of carbon ink  16   a  are located inside first region  23   a ′ and inside second region  24   a ′, and both ends of carbon ink  16   b  are located inside first region  23   b ′ and inside second region  24   b ′. Carbon inks  16   a  and  16   b  are provided with conductivity and have functions as electrodes. 
     Electrophoresis by Micro-Channel Chip 
     First, in micro-channel chip  10 , a buffer solution is injected into first region (injection port)  23   a ′ to fill the interior of channel  22 ′. Next, a sample for analysis is injected. Further, electrode rods  1   a  and  1   b  are inserted into second regions  24   a ′ and  24   b ′ to come into contact with conductive adhesives  26   a  and  26   b.    
     A voltage is applied to both ends of channel  22 ′ as a current flows through electrode rods  1   a  and  1   b . This causes the sample to moves into through channel  22 ′ toward first region (exhaust port)  23   b′.    
     Inside channel  22 ′, the sample is separated according to a different migration speed every molecular weight. A tester can obtain the electrophoresis result by detecting fluorescence intensity. 
     Effect of Present Embodiment 
       FIG. 4  is an enlarged cross-sectional view along line E-E in  FIG. 1A . As shown in  FIG. 4 , the periphery of carbon ink  16   b  ( 16   a ) in film  14  remains unbonded (insufficiently laminated) to chip body  12  due to the thickness of carbon ink  16   b  ( 16   a ), and thus, gaps  31   a  and  31   b  may be produced between chip body  12  and film  14  at edges of carbon ink  16   a  ( 16   b ). 
     Gaps  31   a  and  31   b  become unexpected channels that are connected to first region  23   b ′ ( 23   a ′). Thus, the liquid (buffer solution and sample) injected into channel  22 ′ of micro-channel chip  10  leaks through gaps  31   a  and  31   b  from first region  23   b ′ ( 23   a ′) by the capillary phenomenon. 
     Third region  25   b ′ ( 25   a ′) is formed in micro-channel chip  10  according to the present embodiment. Width W 1  of third region  25   b ′ ( 25   a ′) is formed so as to be greater than width W 2  of carbon ink  16   b  ( 16   a ), and thus, third region  25   b ′ ( 25   a ′) is connected to gaps  31   a  and  31   b . As third region  25   b ′ ( 25   a ′) is filled with conductive adhesive  26   b  ( 26   a ), openings of gaps  31   a  and  31   b  toward third region  25   b ′ ( 25   a ′) are closed. 
     Accordingly, the liquid does not move to second region  24   a ′ ( 24   b ′) from first region  23   b ′ ( 23   a ′) through gaps  31   a  and  31   b.    
     As a result, according to the present embodiment, it is possible to prevent the liquid from leaking outward and prevent contamination of the electrodes or external environment. 
     Variations 
     Hereinafter, variations of the micro-channel chip according to the present embodiment will be described. 
     Variation 1 
       FIG. 5A  to  FIG. 5C  are diagrams illustrating the shape of variation 1 of the micro-channel chip according to the present embodiment. A micro-channel chip  10 - 1  of variation 1 is used to heat a sample using a heater.  FIG. 5A  is a plan view,  FIG. 5B  is a front cross-sectional view along line F-F, and  FIG. 5C  is a bottom view.  FIG. 5A  and  FIG. 5B  show electric heater  1   a - 1  together. In  FIG. 5A  to  FIG. 5C , parts common to those in  FIG. 1A  to  FIG. 1D  are assigned the same reference numerals, and detailed descriptions thereof will be omitted. 
       FIG. 6A  to  FIG. 6C  are diagrams illustrating the shape of the chip body of the micro-channel chip shown in  FIG. 5A  to  FIG. 5C .  FIG. 6A  is a plan view,  FIG. 6B  is a front cross-sectional view along line G-G, and  FIG. 6C  is a bottom view. In  FIG. 6A  to  FIG. 6C , parts common to those in  FIG. 2A  to  FIG. 2D  are assigned the same reference numerals, and detailed descriptions thereof will be omitted. 
     Variation 1 is a case where there is only one metal film  16   a - 1  with an excellent heat transfer property as a transfer function section. In  FIG. 5A  to  FIG. 5C , micro-channel chip  10 - 1  is configured so that the shapes of chip body  12 - 1  and film  14 - 1  are different from those of chip body  12  and film  14  shown in  FIG. 1A  to  FIG. 1D . 
     Further, in  FIG. 6A  to  FIG. 6C , one through hole  23   a , one through hole  24   a  and one through hole  27  are formed in chip body  12 - 1 . Further, one groove  25   a  is formed on undersurface  21 - 1  of chip body  12 - 1 . No micro-groove is formed on chip body  12 - 1 . 
     In a state where chip body  12 - 1  and film  14 - 1  are bonded together, through hole  27  serves as injection port  27 ′ of the adhesive that communicates with third region  25   a ′. In micro-channel chip  10 - 1  of variation 1, adhesive  26 - 1  that fills third region  25   a ′ is injected through injection port  27 ′. Adhesive  26 - 1  is introduced into third region  25   a ′ according to the capillary phenomenon, and is stopped at an opening of third region  25   a ′ toward second region  24   a ′ by the capillary phenomenon. Thus, metal film  16   a - 1  inside second region  24 ′ a  is not covered with adhesive  26 - 1 , and thus, it is possible to cause electric heater  1   a - 1  to be directly contact with metal film  16   a - 1 . 
     In this manner, adhesive  26 - 1  that flows in third region  25   a ′ of the channel shape stops its flow at a place where adhesive  26 - 1  reaches an opening of second region  24   a ′ that is a wide space, and does not cover and hide transfer function section (metal film)  16   a - 1  in second region  24   a ′. Since adhesive  26 - 1  has only to prevent second region  24   a ′ and third region  25   a ′ from communicating with each other and need not have the transfer function, it is possible to increase the degree of freedom for selection. 
     According to variation 1, similarly, the liquid leaked from first region  23 ′ a  is stopped in third region  25 ′ a , and can be prevented from reaching second region  24   a ′. As a result, it is possible to prevent the liquid from leaking, to prevent contamination of an external environment, and to safely heat the sample injected into first region  23   a ′ using electric heater  1   a - 1 . 
     In the above embodiment, a case where carbon inks  16   a  and  16   b  are used as conductive members and metal film  16   a - 1  is used as a heat transfer member has been described, but the present invention is not limited thereto. That is, other conductive members and heat transfer members may be used to achieve the same effect. 
     Further, in the above embodiment, a case where film  14  is bonded to chip body  12  has been described, but the present invention is not limited thereto. For example, as shown in FIG. 1 of PTL 1, a thin plate may be bonded to a chip body to achieve the same effect. 
     According to the present invention, as described in the above embodiment, the space (third region) that communicates with gaps (unexpected channels) that may be produced at edges of the transfer function section is formed between the space (first region) into which the liquid is introduced and the space (second region) electrically or thermally connected thereto via the transfer function section, and the third region is filled with the adhesive. Accordingly, it is possible to prevent the liquid introduced into the first region from leaking out to the space of the second region. As long as this effect can be achieved, the shape of the groove of the substrate member for formation of the first region and the second region is not limited to the shape shown in the above embodiment. The first region may be a space in the middle of a flow passage. 
     This application is entitled and claims the benefit of Japanese Patent Application No. 2011-082820, filed on Apr. 4, 2011, the disclosure of which including the specification, drawings and abstract is incorporated herein by reference in its entirety. 
     INDUSTRIAL APPLICABILITY 
     The fluid handling apparatus and the fluid handling system according to the present invention can be used for an apparatus that carries out an inspection/analysis of trace substances accurately and at high speed in the scientific field such as biochemistry and analytical chemistry or in the medical field. 
     REFERENCE SIGNS LIST 
     
         
           10  Micro-channel chip 
           12 ,  12 - 1  Chip body 
           14 ,  14 - 1  Film 
           16   a ,  16   b  Carbon ink 
           16   a - 1  Metal film 
           22  Micro-groove 
           22 ′ Channel 
           23   a ,  23   b ,  24   a ,  24   b ,  27  Through hole 
           23   a ′,  23   b ′,  26 ′ First region 
           24   a ′,  24   b ′ Second region 
           25   a ,  25   b  Groove 
           25   a ′,  25   b ′ Third region 
           26   a ′,  26   b ′,  26 - 1  Adhesive 
           27 ′ Injection port