Abstract:
A fluid treatment device ( 100 ) has a first substrate ( 210 ), a second substrate ( 120 ), and a resin film ( 130 ) located between the first substrate ( 210 ) and the second substrate ( 120 ). On the first substrate ( 210 ) are formed a first flow channel ( 111 ), a region ( 214 ) facing a valve formed at the end of the first flow channel ( 111 ), a second flow channel ( 112 ), and a barrier wall ( 215 ) located between the region ( 214 ) facing the valve and the end of the second flow channel ( 112 ). On the second substrate ( 120 ) is formed a pressure compartment ( 123 ). The region ( 214 ) facing the valve and the barrier wall ( 215 ) face the pressure compartment ( 123 ) on opposite sides of a diaphragm ( 131 ) of resin film ( 130 ).

Description:
TECHNICAL FIELD 
     The present invention relates to a fluid handling device and a fluid handling method which are used for analysis or processing of a liquid sample, or the like. 
     BACKGROUND ART 
     In recent years, in order to perform analysis of trace amounts of substances such as proteins or nucleic acids with high accuracy and at high speed, microchannel chips have been used. The microchannel chips have an advantage of requiring smaller amounts of reagents and samples and thus are expected to be used in various applications including clinical inspection, food inspection, and environmental inspection. 
     In order to automate processing using the microchannel chip, providing a valve structure in the microchannel chip is proposed (refer to PTL 1, for example). 
     PTL 1 discloses a microchannel chip having a microvalve of a diaphragm valve structure which opens and closes a channel by changing the shape of a side wall of the channel. In the microchannel chip, a second channel is formed in the vicinity of a first channel. When pressure of a fluid in the second channel is increased, a wall (a diaphragm) of the first channel, which is located between the first channel and the second channel, is deformed so as to block the first channel. Therefore, the fluid flow in the first channel can be controlled by adjusting pressure to a fluid in the second channel. 
     CITATION LIST 
     Patent Literature  
     
         
         PTL 1 
         US Patent Application Publication No. 2005/0019794 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     However, the microchannel chip described in PTL 1 has the disadvantage of high manufacturing cost. With the technique described in PTL 1, in order to make the wall (diaphragm) of the first channel have elasticity, the entire microchannel chip is made of an expensive elastomer (e.g.; polydimethylsiloxane (PDMS)). For this reason, with the technique described in PTL 1, it is difficult to manufacture a microchannel chip at a low cost. 
     As means for suppressing the manufacturing cost, it is conceivable to manufacture a microchannel chip by using resin. However, when manufacturing a diaphragm by using a resin film having a certain level of thickness, since resin has high rigidity compared to an elastomer, it is difficult to completely block a channel by a resin film (diaphragm). That is, after a portion of the resin film (diaphragm) comes into contact with a channel, in order to bring the remainder of the diaphragm into contact with the channel, it is necessary to apply a very large amount of pressure. 
     An object of the present invention is to provide a fluid handling device of low manufacturing costs that allows for easy control of fluid flow in a channel, and a fluid handling method using the fluid handling device. 
     Solution to Problem 
     A fluid handling device according to the invention includes: a first substrate which includes a first channel, a valve body facing area formed at an end on one side of the first channel and having a substantially circular segment-shaped opening, a second channel, and a partition wall formed between the valve body facing area and an end on one side of the second channel; a second substrate which includes a third channel and a pressure chamber formed at an end on one side of the third channel and having an opening; and a resin film which is disposed between the first substrate and the second substrate and includes a substantially spherical cap-shaped diaphragm portion, in which the first substrate and the second substrate are integrated with each other with the resin film in between, the diaphragm portion is located between the opening of the valve body facing area, the end on one side of the second channel and the partition wall, and the opening of the pressure chamber, a center of a circular arc which is included in an edge of the opening of the valve body facing area and a center of an outer edge of the diaphragm portion coincide with each other when seen in a plan view, and the diaphragm portion comes into contact with the partition wall due to pressure in the pressure chamber, whereby fluid flow heading for the second channel from the valve body facing area through a gap between the partition wall and the diaphragm portion is stopped. 
     A fluid handling device according to the invention includes: a first substrate which includes a first channel, a valve body facing area formed at an end on one side of the first channel and having a substantially circular opening, a second channel, and a partition wall formed between the valve body facing area and an end on one side of the second channel; a second substrate which includes a third channel and a pressure chamber formed at an end on one side of the third channel and having an opening; and a resin film which is disposed between the first substrate and the second substrate and includes a substantially spherical cap-shaped diaphragm portion, in which the first substrate and the second substrate are integrated with each other with the resin film in between, the diaphragm portion is located between the opening of the valve body facing area, the end on one side of the second channel and the partition wall, and the opening of the pressure chamber, and when seen in a plan view, the diaphragm portion is larger than the opening of the valve body facing area and an edge of the opening of the valve body facing area and an outer edge of the diaphragm portion of the resin film are concentric circles, and the diaphragm portion comes into contact with the partition wall due to pressure in the pressure chamber, whereby fluid flow heading for the second channel from the valve body facing area through a gap between the partition wall and the diaphragm portion is stopped. 
     A fluid handling method according to the invention is a method of handling a fluid by using the fluid handling device described above, including: a step of introducing a first fluid into the first channel to move the first fluid from the first channel through a gap between the partition wall and the diaphragm portion to the second channel; and a step of stopping the first fluid flow by introducing a second fluid into the pressure chamber through the third channel and thus bringing the diaphragm portion into contact with the partition wall due to pressure of the second fluid in the pressure chamber. 
     Advantageous Effects of Invention 
     According to the invention, it is possible to provide a fluid handling device of low manufacturing costs that allows for easy control of fluid flow in a channel, and a fluid handling method using the fluid handling device. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1A  is a plan view of a microchannel chip according to Embodiment 1,  FIG. 1B  is a cross-sectional view taken along line B-B shown in  FIG. 1A , and  FIG. 1C  is a cross-sectional view taken along line C-C shown in  FIG. 1A ; 
         FIG. 2A  is a plan view of a first substrate,  FIG. 2B  is a cross-sectional view taken along line B-B shown in  FIG. 2A , and  FIG. 2C  is a cross-sectional view taken along line C-C shown in  FIG. 2A ; 
         FIG. 3A  is a plan view of a second substrate,  FIG. 3B  is a cross-sectional view taken along line B-B shown in  FIG. 3A , and  FIG. 3C  is a cross-sectional view taken along line C-C shown in  FIG. 3A ; 
         FIG. 4A  is a plan view of a resin film,  FIG. 4B  is a cross-sectional view taken along line B-B shown in  FIG. 4A , and  FIG. 4C  is a cross-sectional view taken along line C-C shown in  FIG. 4A ; 
         FIG. 5  is a partially enlarged plan view of the microchannel chip according to Embodiment 1; 
         FIG. 6  is a partially enlarged plan view of the microchannel chip according to Embodiment 1; 
         FIGS. 7A and 7B  are partially enlarged cross-sectional views of the microchannel chip according to Embodiment 1 for describing how the microchannel chip is used; 
         FIG. 8  is a partially enlarged plan view showing another example of the microchannel chip according to Embodiment 1; 
         FIG. 9  is a plan view of a microchannel chip according to Embodiment 2; 
         FIG. 10A  is a plan view of a first substrate,  FIG. 10B  is a plan view of a second substrate, and  FIG. 10C  is a plan view of a resin film; 
         FIG. 11  is a partially enlarged plan view of the microchannel chip according to Embodiment 2; 
         FIGS. 12A and 12B  are partially enlarged cross-sectional views of the microchannel chip according to Embodiment 2 for describing how the microchannel chip is used; and 
         FIG. 13  is a partially enlarged plan view showing another example of the microchannel chip according to Embodiment 2. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments of the invention will be described in detail with reference to the drawings. In the following description, as a representative example of a fluid handling device according to the invention, a microchannel chip will be described. 
     Embodiment 1 
     Configuration of Microchannel Chip 
       FIGS. 1A to 1C  are diagrams showing the configuration of microchannel chip  100  according to Embodiment 1.  FIG. 1A  is a plan view of microchannel chip  100 ,  FIG. 1B  is a cross-sectional view taken along line B-B shown in  FIG. 1A , and  FIG. 1C  is a cross-sectional view taken along line C-C shown in  FIG. 1A . 
     As shown in  FIGS. 1A to 1C , microchannel chip  100  has first substrate  110 , second substrate  120 , and resin film  130  disposed between first substrate  110  and second substrate  120 . A channel for making a fluid such as a reagent or a liquid sample flow therein is formed in first substrate  110 . On the other hand, resin film  130  functions as a diaphragm (a valve body) of a microvalve which controls the fluid flow flowing in the channel. A pressure chamber for controlling an operation of the diaphragm is formed in second substrate  120 . First substrate  110  and second substrate  120  are integrated with each other through resin film  130 . 
     Hereinafter, each constituent element of microchannel chip  100  will be described. 
     (First Substrate) 
       FIGS. 2A to 2C  are diagrams showing the configuration of first substrate  110 .  FIG. 2A  is a plan view of first substrate  110 ,  FIG. 2B  is a cross-sectional view taken along line B-B shown in  FIG. 2A , and  FIG. 2C  is a cross-sectional view taken along line C-C shown in  FIG. 2A . 
     First substrate  110  is a substantially rectangular transparent resin substrate. The thickness of first substrate  110  is not particularly limited. The thickness is, for example, in a range of 1 mm to 10 mm. The type of resin configuring first substrate  110  is not particularly limited and can be appropriately chosen from known resins. Examples of the resin configuring first substrate  110  include polyethylene terephthalate, polycarbonate, polymethylmethacrylate, vinyl chloride, polypropylene, polyether and polyethylene. 
     As shown in  FIGS. 2A to 2C , first channel  111 , second channel  112 , first fluid introduction port  113 , valve body facing area  114 , partition wall  115 , and fluid outlet port  116  are formed in first substrate  110 . First channel  111 , valve body facing area  114 , and second channel  112  function as a single channel, and thus a fluid introduced from first fluid introduction port  113  can flow to fluid outlet port  116  while the microvalve opens. 
     First channel  111  and second channel  112  are channels in which a fluid (e.g.; a reagent, a liquid sample) introduced from first fluid introduction port  113  flows. First channel  111  and second channel  112  are grooves formed in first substrate  110 . Openings of these grooves are blocked by resin film  130  (refer to  FIG. 1B ). The cross-sectional areas and the cross-sectional shapes of first channel  111  and second channel  112  are not particularly limited. For example, first channel  111  and second channel  112  are channels in which a fluid can move by capillary action. In this case, the cross-sectional shape of each of first channel  111  and second channel  112  is, for example, a substantially rectangular shape in which the dimension (width or depth) of one side is on the order of several tens of μm. As used herein, “cross section of a channel” means the cross section of a channel orthogonal to a direction in which a fluid flows. 
     First fluid introduction port  113  and fluid outlet port  116  are through-holes formed in first substrate  110 . First fluid introduction port  113  is formed at a first end (an end upstream) of first channel  111 . Further, fluid outlet port  116  is formed at a second end (an end downstream) of second channel  112 . Openings on one side of these through-holes are blocked by resin film  130  (refer to  FIG. 1B ). The shapes of first fluid introduction port  113  and fluid outlet port  116  are not particularly limited. The shape is, for example, a substantially columnar shape. The diameters of first fluid introduction port  113  and fluid outlet port  116  are not particularly limited. The diameter is, for example, about 2 mm. 
     Valve body facing area  114  is a recess formed in first substrate  110 . Valve body facing area  114  is formed at a second end (an end downstream) of first channel  111 . An opening of the recess faces resin film  130  (a diaphragm portion  131 ) (refer to  FIG. 1B ). The shape of an opening on the resin film  130  side of valve body facing area  114  is a substantially circular shape (refer to  FIGS. 2A and 5 ). The shape of valve body facing area  114  is not particularly limited as long as the shape of the opening is a substantially circular shape. The shape of valve body facing area  114  is, for example, a columnar shape. The diameter of the opening of valve body facing area  114  is not particularly limited. The diameter is, for example, about 0.5 mm. 
     Partition wall  115  is a wall formed between first channel  111  and a first end (an end upstream) of second channel  112 . As will be described later, partition wall  115  functions as a valve seat of the microvalve. 
     (Second Substrate) 
       FIGS. 3A to 3C  are diagrams showing the configuration of second substrate  120 .  FIG. 3A  is a plan view of second substrate  120 ,  FIG. 3B  is a cross-sectional view taken along line B-B shown in  FIG. 3A , and  FIG. 3C  is a cross-sectional view taken along line C-C shown in  FIG. 3A . 
     Second substrate  120  is a substantially rectangular transparent resin substrate. The thickness of second substrate  120  is not particularly limited. The thickness is, for example, in a range of 1 mm to 10 mm. The type of resin configuring second substrate  120  is not particularly limited and can be appropriately chosen from known resins. An example of the resin configuring second substrate  120  is the same as an example of the resin configuring first substrate  110 . 
     As shown in  FIGS. 3A to 3C , third channel  121 , second fluid introduction port  122 , and pressure chamber  123  are formed in second substrate  120 . 
     Third channel  121  is a channel in which a fluid (e.g.; air) introduced from second fluid introduction port  122  flows. Third channel  121  is a groove formed in second substrate  120 . An opening of the groove is blocked by resin film  130  (refer to  FIG. 1C ). The cross-sectional area and the cross-sectional shape of third channel  121  are not particularly limited. For example, the cross-sectional shape of third channel  121  is a substantially rectangular shape in which, for example, the dimension (width or depth) of one side is on the order of several tens of μm. 
     Second fluid introduction port  122  is a through-hole formed in second substrate  120 . Second fluid introduction port  122  is formed at a first end (an end upstream) of third channel  121 . An opening on one side of the through-hole is blocked by resin film  130  (refer to  FIG. 1C ). The shape of second fluid introduction port  122  is not particularly limited. The shape is, for example, a substantially columnar shape. The diameter of second fluid introduction port  122  is not particularly limited. The diameter is, for example, about 2 mm. 
     Pressure chamber  123  is a recess formed in second substrate  120 . Pressure chamber  123  is formed at a second end (an end downstream) of third channel  121 . An opening of the recess is blocked by resin film  130  (refer to  FIG. 1C ). The shape of an opening of pressure chamber  123  on the resin film  130  side is not particularly limited as long as the opening is the same size as or larger than diaphragm portion  131  of resin film  130 , and is, for example, a substantially circular shape (refer to  FIGS. 3A and 5 ). The shape of pressure chamber  123  is not particularly limited. The shape is, for example, a columnar shape. The diameter of the opening of pressure chamber  123  is not particularly limited. The diameter is, for example, about 1 mm. 
     (Resin Film) 
       FIGS. 4A to 4C  are diagrams showing the configuration of resin film  130 .  FIG. 4A  is a plan view of resin film  130 ,  FIG. 4B  is a cross-sectional view taken along line B-B shown in  FIG. 4A , and  FIG. 4C  is a cross-sectional view taken along line C-C shown in  FIG. 4A . 
     Resin film  130  is a substantially rectangular transparent resin film. Resin film  130  functions as a valve body (a diaphragm) of a microvalve having a diaphragm structure. 
     A first surface of resin film  130  is joined to the surface of first substrate  110  where first channel  111  and the like formed. Further, a second surface of resin film  130  is joined to the surface of second substrate  120  where third channel  121  and the like formed (refer to  FIGS. 1A to 1C ). As described above, resin film  130  blocks the openings of first channel  111 , second channel  112 , first fluid introduction port  113 , and fluid outlet port  116  formed in first substrate  110  and the openings of third channel  121 , second fluid introduction port  122 , and pressure chamber  123  formed in second substrate  120 . 
     The type of resin configuring resin film  130  is not particularly limited as long as resin film  130  can function as a valve body (a diaphragm), and can be appropriately chosen from known resins. An example of the resin configuring resin film  130  is the same as the example of the resin configuring first substrate  110 . From the perspective of improving adhesion between resin film  130  and first and second substrates  110  and  120 , it is preferable that the resin configuring resin film  130  be the same as the resin configuring first substrate  110  and second substrate  120 . 
     The thickness of resin film  130  is not particularly limited as long as resin film  130  can function as a valve body (a diaphragm), and can be appropriately set according to the type (rigidity) of resin. For example, the thickness of resin film  130  is about 20 μm. 
     As shown in  FIGS. 4A to 4C , resin film  130  includes substantially spherical cap-shaped diaphragm portion  131 . As shown in  FIG. 1B , valve body facing area  114 , partition wall  115 , and the first end (the end upstream) of second channel  112  of first substrate  110  and pressure chamber  123  of second substrate  120  face each other with resin film  130  interposed therebetween. The portion which is located between the opening of valve body facing area  114 , partition wall  115 , and the first end (the end upstream) of second channel  112 , and the opening of pressure chamber  123 , of resin film  130 , is diaphragm portion  131 . Diaphragm portion  131  has a substantially spherical cap shape and is not joined to first substrate  110  and second substrate  120 . 
     As shown in  FIGS. 4B and 4C , diaphragm portion  131  is deformed so as to form a protruding shape toward pressure chamber  123 . For this reason, when pressure in pressure chamber  123  is not increased, diaphragm portion  131  does not come into contact with partition wall  115  of first substrate  110 . The height of diaphragm portion  131  in a normal state is not particularly limited as long as a fluid can flow through a gap which is formed between diaphragm portion  131  and partition wall  115 . For example, the height of diaphragm portion  131  is on the order of several tens of μm. 
       FIG. 5  is a partially enlarged plan view of the microchannel chip  100 . In this drawing, constituent elements formed in first substrate  110  are shown by solid lines, constituent elements formed in second substrate  120  are shown by dashed lines, and a constituent element formed in resin film  130  is shown by a dashed-dotted line. As described above, the shape of the opening on the resin film  130  side of valve body facing area  114  formed in first substrate  110  is a substantially circular shape. Further, the shape of diaphragm portion  131  of resin film  130  is a substantially spherical cap shape. Since diaphragm portion  131  faces not only valve body facing area  114 , but also partition wall  115  and the first end (the end upstream) of second channel  112 , diaphragm portion  131  is larger than the substantially circular opening of valve body facing area  114 . On the other hand, diaphragm portion  131  is the same size as or smaller than the opening of pressure chamber  123 . 
     As shown in  FIG. 5 , when microchannel chip  100  is viewed in a plan view, center C1 of the substantially circular opening of valve body facing area  114  coincides with center C2 of an outer edge of substantially spherical cap-shaped diaphragm portion  131 . That is, an edge of the opening of valve body facing area  114  and the outer edge of diaphragm portion  131  of resin film  130  are concentric circles. By doing so, as shown in  FIG. 6 , distance L from center C2 of diaphragm portion  131  to partition wall  115  becomes constant (the same distance as the radius of valve body facing area  114 ). 
     In addition, in the example shown in  FIGS. 1A to 1C ,  5 , and  6 , an aspect is shown in which the sizes of diaphragm portion  131  and the opening of pressure chamber  123  almost coincide with each other. However, the invention is not limited thereto, and the size of diaphragm portion  131  is not particularly limited as long as diaphragm portion  131  is located in the opening of pressure chamber  123  and formed so as to function as a diaphragm for opening and closing a communication portion between first channel  111  and second channel  112 . That is, the size of diaphragm portion  131  may be the same size as or smaller than the opening of pressure chamber  123 . 
     Microchannel chip  100  according to the present embodiment is manufactured, for example, by joining first substrate  110  shown in  FIGS. 2A to 2C , second substrate  120  shown in  FIGS. 3A to 3C , and resin film  130  (or flat resin film  130 ) shown in  FIGS. 4A to 4C . For example, resin film  130  is joined to first substrate  110  and second substrate  120  by thermocompression bonding with various conditions adjusted. 
     [How to Use Microchannel Chip] 
     Next, how to use microchannel chip  100  according to the present embodiment will be described with reference to  FIGS. 7A and 7B .  FIGS. 7A and 7B  are partially enlarged cross-sectional views (corresponding to  FIG. 1B ) of microchannel chip  100  for describing how microchannel chip  100  is used. 
     First, as shown in  FIG. 7A , liquid  140  such as a reagent or a liquid sample is introduced into first channel  111  by supplying liquid  140  into first fluid introduction port  113 . At this time, pressure in pressure chamber  123  is not increased and thus a gap is formed between resin film  130  (diaphragm portion  131 ) and partition wall  115  (a valve open state). Liquid  140  advances through first channel  111 , the gap between partition wall  115  and resin film  130  (diaphragm portion  131 ), and second channel  112  by capillary action or pressure from the outside and reaches fluid outlet port  116 . In addition, a fluid (a first fluid) which is introduced from first fluid introduction port  113  need not be liquid and may be gas. 
     Subsequently, as shown in  FIG. 7B , air is introduced from second fluid introduction port  122  into pressure chamber  123  through third channel  121 . As a result, pressure in pressure chamber  123  increases, and thus the shape of resin film  130  (diaphragm portion  131 ) changes. Specifically, diaphragm portion  131  turns into a protruding shape toward the valve body facing area  114  side. In this way, resin film  130  (diaphragm portion  131 ) comes into contact with partition wall  115  (a valve close state). Liquid  140  cannot advance between partition wall  115  and resin film  130  (diaphragm portion  131 ) and the flow of liquid  140  stops. In addition, a fluid (a second fluid) which is introduced from second fluid introduction port  122  need not be air and may be liquid or gas other than air. 
     When diaphragm portion  131  turns into the protruding shape toward the valve body facing area  114  side, since the shape of diaphragm portion  131  is a substantially circular shape, the heights of the respective points of diaphragm portion  131  change concentrically. That is, when the distances from the center of diaphragm portion  131  are the same, heights are also the same. As described above, in microchannel chip  100  according to the present embodiment, distance L from the center of diaphragm portion  131  to partition wall  115  is constant (the same distance as the radius of valve body facing area  114 ) (refer to  FIG. 6 ). Therefore, when diaphragm portion  131  turns into the protruding shape toward the valve body facing area  114  side, diaphragm portion  131  uniformly comes into contact with partition wall  115 . As a result, in microchannel chip  100  according to the present embodiment, even if pressure in pressure chamber  123  is not excessively increased, it is possible to reliably stop the flow of liquid  140  in first channel  111 . 
     By the above procedure, allowing liquid  140  to flow from first channel  111  to second channel  112  and stopping the flow of liquid  140  from first channel  111  to second channel  112  can be performed at any timing. For example, it is possible to allow liquid  140  to react with a specific reagent in first fluid introduction port  113  for a given length of time, thereafter, moving liquid  140  in first fluid introduction port  113  into fluid outlet port  116 , and react liquid  140  with another reagent in fluid outlet port  116 . 
     [Effects] 
     Microchannel chip  100  according to the present embodiment allows easy control of the fluid (a first fluid) flow flowing from first channel  111  to second channel  112 , by adjusting the pressure of a fluid (a second fluid) in pressure chamber  123 . Further, since microchannel chip  100  according to the present embodiment can be manufactured using resin, rather than an elastomer, it is possible to suppress manufacturing costs. In this manner, in microchannel chip  100  according to the present embodiment, a manufacturing cost is low and it is possible to easily control the fluid flow in a channel. 
     In addition, in the description so far, microchannel chip  100  has been described in which one microvalve structure which includes valve body facing area  114 , partition wall  115 , and pressure chamber  123  is formed. However, the number of microvalve structures in microchannel chip  100  is not limited thereto. For example, as shown in  FIG. 8 , a plurality of microvalve structures may be formed in single microchannel chip  100 . 
     Embodiment 2 
     Configuration of Microchannel Chip 
       FIG. 9  is a plan view showing the configuration of microchannel chip  200  according to Embodiment 2. Microchannel chip  200  has, similar to microchannel chip  100  according to Embodiment 1, first substrate  210 , second substrate  120 , and resin film  130  disposed between first substrate  210  and second substrate  120  (refer to  FIGS. 12A  and  12 B). 
       FIG. 10A  is a plan view of first substrate  210 ,  FIG. 10B  is a plan view of second substrate  120 , and  FIG. 10C  is a plan view of resin film  130 . Similar to microchannel chip  100  according to Embodiment 1, first substrate  210  and second substrate  120  are integrated with each other through resin film  130  (refer to  FIGS. 12A and 12B ). 
     In microchannel chip  200  according to Embodiment 2, the shapes of valve body facing area  214  and partition wall  215  provided in first substrate  210  are different from those in microchannel chip  100  according to Embodiment 1. Therefore, in the present embodiment, only first substrate  210  will be described. The same constituent elements as those in microchannel chip  100  according to Embodiment 1 are denoted by the same reference numerals and description thereof is omitted. 
     As shown in  FIG. 10A , first channel  111 , second channel  112 , first fluid introduction port  113 , valve body facing area  214 , partition wall  215 , fluid outlet port  116  are formed in first substrate  210 . First channel  111 , valve body facing area  214 , and second channel  112  function as a single channel, and thus a fluid introduced from first fluid introduction port  113  can flow to fluid outlet port  116  while the microvalve opens. 
     Valve body facing area  214  is a recess formed in first substrate  210 . Valve body facing area  214  is formed at a second end (an end downstream) of first channel  111 . An opening of the recess faces resin film  130  (diaphragm portion  131 ) (refer to  FIGS. 12A and 12B ). The shape of an opening on the resin film  130  side of valve body facing area  214  is an approximate circular segment (refer to  FIG. 10A ). As used herein, “circular segment” refers to a shape which is obtained when a circle is divided into two by a single chord. The circular segment includes a single circular arc and a single chord connecting both ends of the circular arc. The shape of valve body facing area  214  is not particularly limited as long as the shape of the opening is an approximate circular segment. For example, the valve body facing area  214  has a columnar shape whose bases are circular segments. 
     Partition wall  215  is a wall formed between valve body facing area  214  (a chord portion of the circular segment) and a first end (an end upstream) of second channel  112 . Partition wall  215  functions as a valve seat of a microvalve. 
       FIG. 11  is a partially enlarged plan view of microchannel chip  200 . In this drawing, constituent elements formed in first substrate  210  are shown by solid lines, constituent elements formed in second substrate  120  are shown by dashed lines, and a constituent element formed in resin film  130  is shown by a dashed-dotted line. As described above, the shape of the opening on the resin film  130  side of valve body facing area  214  formed in first substrate  210  is an approximate circular segment. The shape of diaphragm portion  131  of resin film  130  is a substantially spherical cap shape. 
     As shown in  FIG. 11 , when microchannel chip  200  is viewed in a plan view, center C1 of the circular arc which is a portion of an edge of the approximately circular segment-shaped opening of valve body facing area  214  coincides with center C2 of an outer edge of substantially spherical cap-shaped diaphragm portion  131 . Further, the radius of the outer edge of diaphragm portion  131  is smaller than the radius (the distance between center C1 and the circular arc) of the circular arc of valve body facing area  214 . By doing so, as shown in  FIG. 11 , the distance from the edge (a circular arc portion) of the opening of valve body facing area  214  to the outer edge of diaphragm portion  131  becomes constant. In addition, as long as the distance from the edge (the circular arc portion) of the opening of valve body facing area  214  to the outer edge of diaphragm portion  131  is constant, the radius of the outer edge of diaphragm portion  131  may be equal to or slightly larger than the radius (the distance between center C1 and the circular arc) of the circular arc of valve body facing area  214 . Resin film  130  between the edge (the circular arc portion) of the opening of valve body facing area  214  and the outer edge of diaphragm portion  131  has a flat plate shape (refer to  FIGS. 12A and 12B ). 
     In addition, even when the radius of the outer edge of diaphragm portion  131  is smaller than the radius of the circular arc of valve body facing area  214 , since the shape of the opening of valve body facing area  214  is an approximate circular segment, diaphragm portion  131  can face not only valve body facing area  214 , but also partition wall  215  and the first end (the end upstream) of second channel  112 . 
     Microchannel chip  200  according to the present embodiment can be manufactured, for example, by joining first substrate  210  shown in  FIG. 10A , second substrate  120  shown in  FIG. 10B , and resin film  130  shown in  FIG. 10C  to each other. For example, resin film  130  is joined to first substrate  210  and second substrate  120  by thermocompression bonding with various conditions adjusted. 
     [How to Use Microchannel Chip] 
     Next, how to use microchannel chip  200  according to the present embodiment will be described with reference to  FIGS. 12A and 12B .  FIGS. 12A and 12B  are partially enlarged cross-sectional views of microchannel chip  200  for describing how microchannel chip  200  is used. 
     First, as shown in  FIG. 12A , liquid  140  such as a reagent or a liquid sample is introduced into first channel  111  by supplying liquid  140  into first fluid introduction port  113 . At this time, pressure in pressure chamber  123  is not increased and thus a gap is formed between resin film  130  (diaphragm portion  131 ) and partition wall  215  (a valve open state). Liquid  140  advances through first channel  111 , the gap between partition wall  215  and resin film  130  (diaphragm portion  131 ), and second channel  112  by capillary action or pressure from the outside and reaches fluid outlet port  116 . In addition, a fluid (a first fluid) which is introduced from first fluid introduction port  113  need not be liquid and may be gas. 
     Subsequently, as shown in  FIG. 12B , air is introduced from second fluid introduction port  122  into pressure chamber  123  through third channel  121 . As a result, pressure in pressure chamber  123  increases, and thus the shape of resin film  130  (diaphragm portion  131 ) changes. Specifically, diaphragm portion  131  turns into a protruding shape toward the valve body facing area  214  side. In this way, resin film  130  (diaphragm portion  131 ) comes into contact with partition wall  215  (a valve close state). Liquid  140  cannot advance between partition wall  215  and resin film  130  (diaphragm portion  131 ) and the flow of liquid  140  stops. In addition, a fluid (a second fluid) which is introduced from second fluid introduction port  122  need not be air and may be liquid or gas other than air. 
     In microchannel chip  200  according to the present embodiment, since the radius of the outer edge of diaphragm portion  131  is smaller than the radius of the circular arc of valve body facing area  214 , it is difficult for a gap to be formed between diaphragm portion  131  and partition wall  215  (refer to  FIG. 12B  by comparing with  FIG. 7B ). Therefore, when diaphragm portion  131  turns into the protruding shape toward the valve body facing area  214  side, diaphragm portion  131  uniformly comes into contact with partition wall  215 . As a result, in microchannel chip  200  according to the present embodiment, even if pressure in pressure chamber  123  is not excessively increased, it is possible to reliably stop the flow of liquid  140  in first channel  111 . 
     By the above procedure, allowing liquid  140  to flow from first channel  111  to second channel  112  and stopping the flow of liquid  140  from first channel  111  to second channel  112  can be performed at any timing. 
     [Effects] 
     Microchannel chip  200  according to the present embodiment has the effects that it is difficult for air bubbles to enter between diaphragm portion  131  and partition wall  215  and therefore easier to handle microchannel chip  200 , in addition to the same effects as those of microchannel chip  100  according to Embodiment 1. 
     In addition, as shown in  FIG. 13 , two or more protruding stripes or recessed stripes  214   a  and  214   b  extending in a direction perpendicular to resin film  130  may be formed in a side wall configuring valve body facing area  214 . In this case, it is preferable that the two or more protruding stripes or recessed stripes  214   a  and  214   b  be disposed symmetrically with respect to an opening of first channel  111 . By doing so, it becomes possible to make liquid  140  passing through a central portion in valve body facing area  214  preferentially flow, and thus it becomes more difficult for air bubbles to enter between diaphragm portion  131  and partition wall  215 . 
     This application claims the right of priority based on Japanese Patent Application No. 2011-161914 filed on Jul. 25, 2011 and Japanese Patent Application No. 2012-160407 filed on Jul. 19, 2012. The entire contents described in the specifications and the drawings of the applications are incorporated herein by reference. 
     INDUSTRIAL APPLICABILITY 
     The fluid handling device according to the invention is useful as a microchip or a microchannel chip which is used in, for example, a scientific field, a medical field, or the like. 
     REFERENCE SIGNS LIST 
     
         
           100 ,  200  Microchannel chip 
           110 ,  210  First substrate 
           111  First channel 
           112  Second channel 
           113  First fluid introduction port 
           114 ,  214  Valve body facing area 
           115 ,  215  Partition wall 
           116  Fluid outlet port 
           120  Second substrate 
           121  Third channel 
           122  Second fluid introduction port 
           123  Pressure chamber 
           130  Resin film 
           131  Diaphragm portion 
           140  Liquid 
           214   a ,  214   b  Recessed stripe