JP2011058943A - Liquid feeding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid feeding device wherein a valve is operated automatically only by injecting a solution into a channel without using an external device. <P>SOLUTION: This liquid feeding device 20 has two channels 23, 24. In the liquid feeding device 20, the one channel 23 includes a first reservoir 25 on the end, and a valve part 27 is arranged on the outlet side to the channel of the first reservoir 25, and the other channel 24 includes a second reservoir 28 on the end, and an operation part 30 is arranged at a prescribed distance from the outlet side to the channel of the second reservoir 28. The valve part 27 includes a valve electrode 31 having an electro-wetting action, and the operation part 30 includes an operation electrode 32 wherein a potential is changed by a battery action by being brought into contact with electrolytic solution, and the valve electrode 31 of the valve part 27 has an electric connection to the operation electrode 32 of the operation part 30. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid feeding device, and more particularly to a liquid feeding device that controls and feeds a small amount of fluid used in research fields such as chemistry, biology, medicine, and nanotechnology.

  In recent years, chemical reactions, cell culture, separation detection, etc. have been performed on a microchemical analysis system (μTAS) that performs chemical reactions on a chip, or a chip that has a small groove or indentation on a small substrate such as glass. Research on Lab on a Chip, which integrates laboratory processes (lab processes), has been actively conducted. As described above, this intends to miniaturize a conventional analysis system or chemical laboratory to the extent that it can be put on a palm.

  By miniaturizing the analysis system and the like, effects such as (1) a small amount of sample and reagent, (2) faster response, and (3) high throughput can be realized. The applications of these miniaturized analysis systems (hereinafter referred to as microsystems) are various, but on such microsystems, it is necessary to control and send a small amount of fluid. In particular, it is expected to realize a liquid delivery device in which all elements are integrated.

  Mechanical micropumps and microvalves have already been studied since the 1980s as devices for controlling and feeding a small amount of fluid. However, the construction of an advanced liquid delivery device in which these are integrated has been hardly successful so far. This seems to be due to the fact that it is difficult to achieve a high degree of structural integration. For this reason, when it is desired to introduce a minute fluid (for example, a solution) into a minute flow path and send it, a commercially available micro syringe pump is often used. Of course, this may be sufficient depending on the purpose such as basic research, but if a microsyringe pump is used, portability is impaired. Also, the micro syringe pump is very expensive.

  Therefore, as a means for feeding liquid in a relatively complicated microchannel, there is a liquid feeding mechanism that uses electroosmotic flow. The electroosmotic flow is a movement phenomenon that a solution in contact with a glass tube or the like exhibits under a high voltage, and is usually generated by analysis using capillary electrophoresis using DNA or the like as a measurement target. Capillary electrophoresis is performed by inserting an electrode into a solution reservoir containing DNA or other particles formed at the end of a microfluidic channel formed in quartz glass. This is a phenomenon in which a voltage is applied to move the solution in the microchannel. A liquid feeding mechanism using electroosmotic flow (hereinafter referred to as an electroosmotic pump) is structurally very simple and can be easily fed through a complicated flow channel network.

  By the way, regarding the electroosmotic flow, for example, the following Patent Document 1 discloses a material injection device of a capillary electrophoresis apparatus that suppresses electrophoresis and injects a material into the capillary by the electroosmotic flow (Patent Document 1). 1).

  However, conventional micropumps and microvalves have a problem that drive voltage and power consumption increase. Specifically, for example, even if the drive voltage is low, it is several tens of volts, and accordingly, power consumption has become a problem. Furthermore, the smaller the flow path, the greater the influence of interfacial tension and the like, and the resistance of the fluid flowing in the flow path increases. For this reason, there is a problem that liquid feeding becomes difficult particularly when a conventional mechanical pump such as a micropump or a microvalve is used. Similarly, the electroosmotic pump also has a problem because a high voltage is required, and the power consumption becomes too large to be ignored.

  Therefore, it has a simple structure, consumes little power, and can smoothly feed liquids even if the flow path is miniaturized. As a liquid-feeding apparatus for providing a highly integrated micro liquid-feeding system that can efficiently perform the liquid-feeding control, a liquid-feeding apparatus disclosed in Patent Document 2 has been proposed.

  The liquid delivery device disclosed in Patent Document 2 has a hydrophilic flow path surface in which a hydrophobic region is partially formed, the first substrate, and the position facing the flow path surface are made hydrophilic. A second substrate on which a working electrode is formed at a position facing the hydrophobic region, and a reference electrode, and a distance between the flow path surface and the second substrate is arranged; A liquid feeding device in which a flow path space is formed between a flow path surface and the second substrate, wherein the fluid is disposed between the first substrate and the second substrate, and the fluid is The fluid is controlled to move in the flow path space by generating a potential difference between the reference electrode and the working electrode in a state where the reference electrode and the working electrode are in contact with each other.

  Further, Patent Document 3 discloses a highly integrated liquid feeding device that controls and feeds a small amount of fluid using an electrochemical principle.

  Further, Patent Document 4 discloses a liquid feeding device that feeds a fluid having an electrolyte into a flow path so that the fluid can be divided and fed by a certain amount.

  In addition, a gold electrode and silver / silver chloride are formed in a micro flow path, and the liquid electrode is controlled by a potentiostat to control the liquid feed, and a long electrode is formed in the direction along the flow path. However, there has been reported a liquid feeding device that performs liquid feeding utilizing a change in wettability on the electrode surface (see Non-Patent Document 1). Furthermore, a liquid feeding device has been reported in which a gold electrode is formed in a part of a flow path and used as a valve by utilizing a change in wettability on the electrode surface by applying a voltage from the outside (Non-patent Document 2). reference).

Japanese Patent Laid-Open No. 5-142198 JP 2006-220606 A JP 2006-348906 A JP 2009-66464 A

W. Satoh et al. `` On-Chip Microfluidic Transport and Mixing Using Electrowetting and Incorporation of Sensing Functions '' Analytical Chemistry, 77 (2005) 6857 W. Satoh et al. `` Electrowetting-based valve for the control of the capillary flow '' Journal Applied Physics, 103 (2008) 034903

  However, in a liquid delivery device in which liquid control elements such as conventional micropumps and microvalves are integrated, it is necessary to apply a voltage from the outside in order to drive the micropumps and microvalves. It was necessary to connect an external device for applying.

  In view of the above-described problems, an object of the present invention is to provide a liquid feeding device in which valve operation is automatically performed only by injecting a solution into a flow path without using an external device.

  The liquid delivery device according to the present invention is configured as follows in order to achieve the above object.

  The first liquid delivery device (corresponding to claim 1) has two flow paths, and the end of one flow path is provided with a first liquid reservoir, and the flow of the first liquid reservoir A valve portion is disposed on the outlet side to the passage, and the second liquid reservoir portion is provided at the end of the other flow path, and is operated at a predetermined distance from the outlet side to the flow path of the second liquid reservoir portion. The valve section is provided with a valve electrode having an electrowetting action, and the operation section is a hydrophilic operation in which the electric potential changes due to the battery action when in contact with the electrolyte. An electrode is provided, and the valve electrode of the valve portion and the operation electrode of the operation portion are electrically connected.

  The second liquid feeding device (corresponding to claim 2) has two flow paths, and has an end of one of the flow paths with a first liquid reservoir, and the flow of the first liquid reservoir Valve portions and operation portions are alternately arranged in order from the outlet side to the passage, and the second liquid reservoir portion is provided at the end of the other flow passage, and the outlet of the second liquid reservoir portion to the flow passage is provided. A liquid delivery device in which an operation part and a valve part are alternately arranged in order from the side, wherein the valve part is provided with a valve electrode having an electrowetting action, and the operation part comes into contact with the electrolytic solution to It has a hydrophilic operation electrode whose electric potential changes by action, and the valve electrode of the valve unit and the operation electrode of the operation unit which are alternately arranged in each of the two flow paths are electrically connected to each other. To do.

  A third liquid delivery device (corresponding to claim 3) includes at least one liquid reservoir, a flow path in which a valve portion is disposed on the outlet side of the liquid reservoir, and at least one operation portion extended from the liquid reservoir. A liquid delivery device provided with a disposed flow path, wherein the valve part is provided with a valve electrode having an electrowetting action, and the operation part is hydrophilic in which the potential changes due to the battery action when in contact with the electrolyte. The operation electrode is provided, and the valve electrode of the valve portion and the operation electrode of the operation portion are electrically connected to each other.

  A fourth liquid feeding device (corresponding to claim 4) is a liquid feeding device provided with a valve portion and an operation portion in contact with a part of a flow path, and the valve portion has a valve electrode having an electrowetting action. The operation unit includes a hydrophilic operation electrode whose potential changes due to battery action when it comes into contact with the electrolyte solution, and electrical connection is established when the valve electrode of the valve unit and the operation electrode of the operation unit are in contact with each other. It is characterized by being made.

  The fifth liquid feeding device (corresponding to claim 5) has two flow paths extending from the two liquid reservoirs and a mixing part at the boundary between the two flow paths, and is different from the two liquid reservoirs. A liquid feeding device comprising a flow path having an operation part at a predetermined distance from a liquid reservoir, wherein the mixing part includes a mixing electrode having an electrowetting action, and the operation part is in contact with the electrolyte solution to thereby provide a battery. A hydrophilic operation electrode whose potential is changed by an action is provided, and the mixing electrode of the mixing unit and the operation electrode of the operation unit are electrically connected.

    In the sixth liquid feeding device (corresponding to claim 6), in the above structure, preferably, the valve electrode is made of gold.

    The seventh liquid feeding device (corresponding to claim 7) is characterized in that, in the above configuration, the mixed electrode is preferably made of gold.

    In an eighth liquid feeding device (corresponding to claim 8), in the above structure, preferably, the operation electrode is made of zinc, and silver / silver chloride is formed in the first liquid reservoir and the second liquid reservoir. An electrode is provided, and the silver / silver chloride electrode of the first liquid reservoir and the silver / silver chloride electrode of the second liquid reservoir are electrically connected, and the electrolytic solution is put into the liquid reservoir, and the silver / silver chloride electrode And the operation electrode is immersed in an electrolytic solution to form a battery.

    In the ninth liquid feeding device (corresponding to claim 9), in the above structure, the flow path is preferably formed of a glass substrate and a polydimethylsiloxane (PDMS) substrate.

  ADVANTAGE OF THE INVENTION According to this invention, the liquid feeding apparatus which can perform liquid feeding control autonomously without the control from the outside is realizable.

It is a schematic diagram which shows the principle of liquid feeding. It is the top view (a) and A-A 'sectional view (b) of the liquid feeding device concerning a 1st embodiment of the present invention. It is the top view which decomposed | disassembled the liquid feeding apparatus which concerns on 1st Embodiment of this invention. It is a figure explaining the effect | action of the liquid feeding apparatus which concerns on 1st Embodiment of this invention. It is a figure explaining the effect | action of the liquid feeding apparatus which concerns on 1st Embodiment of this invention. It is a flowchart explaining the manufacturing method of the liquid feeding apparatus which concerns on 1st Embodiment of this invention. It is the top view (a) and A-A 'sectional drawing (b) of the 1st modification of the liquid feeding apparatus which concerns on 1st Embodiment of this invention. It is the top view (a) and A-A 'sectional view (b) of the 2nd modification of the liquid feeding apparatus which concerns on 1st Embodiment of this invention. It is the top view (a) and B-B 'sectional view (b) of the liquid delivery apparatus concerning a 2nd embodiment of the present invention. It is a figure explaining the effect | action of the liquid feeding apparatus which concerns on 2nd Embodiment of this invention. It is a figure explaining the effect | action of the liquid feeding apparatus which concerns on 2nd Embodiment of this invention. It is a figure explaining the effect | action of the liquid feeding apparatus which concerns on 2nd Embodiment of this invention. It is a figure explaining the effect | action of the liquid feeding apparatus which concerns on 2nd Embodiment of this invention. It is a top view of the liquid feeding apparatus which concerns on 3rd Embodiment of this invention. It is a figure explaining the effect | action of the liquid feeding apparatus which concerns on 3rd Embodiment of this invention. It is a figure explaining the effect | action of the liquid feeding apparatus which concerns on 3rd Embodiment of this invention. It is a figure explaining the effect | action of the liquid feeding apparatus which concerns on 3rd Embodiment of this invention. It is a top view of the liquid feeding apparatus which concerns on 4th Embodiment of this invention. It is a figure explaining the effect | action of the liquid feeding apparatus which concerns on 4th Embodiment of this invention. It is a figure explaining the effect | action of the liquid feeding apparatus which concerns on 4th Embodiment of this invention. It is a figure explaining the effect | action of the liquid feeding apparatus which concerns on 4th Embodiment of this invention. It is a top view of the liquid feeding apparatus which concerns on 5th Embodiment of this invention. It is a figure explaining the effect | action of the liquid feeding apparatus which concerns on 5th Embodiment of this invention. It is a figure explaining the effect | action of the liquid feeding apparatus which concerns on 5th Embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Preferred embodiments (examples) of the present invention will be described below with reference to the accompanying drawings.

  The present invention is based on the phenomenon that the interfacial tension between the electrode and the fluid (particularly electrolyte) interface can be controlled by the electrode potential (this control method is called electrowetting).

  First, the principle of liquid feeding based on the electrowetting will be described. FIG. 1 is a schematic diagram showing the principle of liquid feeding. FIG. 1 is a side sectional view showing a state in which a droplet 12 is placed on an electrode 11 formed of gold formed on a glass substrate 10. The droplet 12 is, for example, an electrolytic solution.

  In the case of FIG. 1, a power source 13 is connected to the electrode 11 on which the droplet 12 is placed and in contact. The reference electrode 9 is in contact with the droplet 12 from the power source 13 through the switch 14. When the droplet 12 is placed on the electrode 11 and the droplet 12 is in contact with the reference electrode 9, the switch 14 is turned on to apply a voltage to the electrode 11. A potential difference is generated between them. FIG. 1A shows a state before the voltage is applied, and FIG. 1B shows a state where the voltage is applied.

  As shown in FIGS. 1A and 1B, the droplet in a state where a voltage is applied, rather than the contact angle θ of the droplet 12 with respect to the electrode 11 before the voltage is applied (see FIG. 1A). The contact angle θ ′ of 12 with respect to the electrode 11 (see FIG. 1B) is smaller. That is, when a voltage is applied, the electrode 11 is easily wetted.

  This is considered to be due to the following principle. As shown in FIG. 1B, the arrow 15a is the interfacial tension generated between the gas and the solid, the arrow 15b is the interfacial tension generated between the gas and the liquid, and the arrow 15c is between the solid and the liquid. It is the interfacial tension that occurs. When a potential difference is generated between the electrode 11 and the reference electrode 9, the interfacial tension (arrow 15c) between the solid electrode 11 and the liquid droplet 12 (at the electrode 11-droplet 12 interface) is increased. descend. In other words, the electrode 11 is easily wetted by the droplet 12. Then, due to the interfacial tension between the gas and the solid (arrow 15a), the droplet 12 travels on the electrode 11 and is fed. When the voltage application is stopped and the potential difference between the electrode 11 and the reference electrode 9 is returned to zero, the liquid feeding stops.

  It is noted that the interfacial tension (arrow 15c) between the electrode 11 and the droplet 12 (at the electrode 11-droplet 12 interface) is affected by adsorption of ions in the droplet 12 to the surface of the electrode 11. It is. When it is changed to a more negative potential, adsorption of the cation becomes dominant, and when it is changed to a more positive potential, adsorption of the anion becomes dominant.

  FIG. 2A is a plan view of the liquid delivery device according to the first embodiment of the present invention, and FIG. The liquid feeding device 20 includes, for example, two flow paths 23 and 24 formed by a first substrate 21 and a second substrate 22. A first liquid reservoir 25 is provided at the end of one of the two channels 23 and 24. A valve portion 27 is arranged on the outlet 26 side of the first liquid reservoir portion 25 to the flow path 23. A second liquid reservoir 28 is provided at the end of the other channel 24. An operation unit 30 is disposed at a predetermined distance from the outlet 29 side of the second liquid reservoir 28 to the flow path 24.

  The first substrate 21 is made of, for example, a glass substrate, and the second substrate 22 is made of, for example, polydimethylsiloxane (PDMS).

  The valve unit 27 includes an electrode (valve electrode) 31 having an electrowetting action shown in FIG. For example, gold or the like is used for the valve electrode 31. The valve electrode 31 may be made of carbon or bismuth in addition to gold. This is because when the potential of the valve electrode 31 is changed, hydrogen or the like is not generated and the liquid feeding is hardly affected.

  The operation unit 30 includes an operation electrode 32 whose potential is changed by a battery action by being in contact with the electrolytic solution. The operation electrode 32 is made of, for example, zinc having hydrophilicity, and a reference electrode 33 made of, for example, silver / silver chloride is provided in the second liquid reservoir 28. That is, it is formed of an electrode substrate made of silver, and a film layer made of silver chloride formed on the electrode substrate (hereinafter referred to as silver / silver chloride or Ag / AgCl). An electrolyte is put into the second liquid reservoir 28, and the silver / silver chloride reference electrode 33 and the operation electrode 32 are immersed in the electrolyte to form a battery. In addition, by forming the reference electrode 33 with silver / silver chloride, there is an advantage that the potential of the reference electrode 33 does not change so much when a battery is formed by introducing an electrolytic solution. The first liquid reservoir 25 is provided with a reference electrode 34 similar to the reference electrode 33. The reference electrode 33 and the reference electrode 34 are electrically connected by a wiring 33a such as gold.

  The valve electrode 31 of the valve unit 27 and the operation electrode 32 of the operation unit 30 are electrically connected by a wiring 35 such as gold.

  The valve electrode 31, the operation electrode 32, the reference electrodes 33 and 34, and the wiring 35 are formed on the first substrate 21 made of a glass substrate. The flow path portions 23 and 24 are formed on the second substrate 22.

  In the second substrate 22, the flow path portions 23 and 24 are formed in a concave shape and have a flow path surface 36. Specifically, the bottom surfaces of the elongated channel portions 23 and 24 formed in a concave shape are the channel surfaces 36 and 37. Here, the channel surface means the surface of the substrate forming the channel.

  The flow path surfaces 36 and 37 are hydrophobic. The glass surface facing the flow path surfaces 36 and 37 of the first substrate 21 is hydrophilic.

  In the second substrate 22, a concave first liquid reservoir (reservoir) 25 and a second liquid reservoir 28 are formed. The first liquid reservoir 25 is for storing a fluid (solution, droplet, sample) to be sent along the flow path surface 23. The second liquid reservoir 28 is for storing a fluid (electrolytic solution) to be fed along the flow path surface 24. The first liquid reservoir 25 is formed with an inlet 38 for introducing a fluid, and the second liquid reservoir 28 is formed with an inlet 39 for introducing a fluid.

  The second substrate 22 is made of, for example, a resin material, and materials such as silicone rubber, acrylic, and PET (polyethylene terephthalate) are conceivable. In the present embodiment, the substrate 22 is made of polydimethylsiloxane (PDMS) (the substrate 22 is also referred to as a PDMS substrate). Forming the substrate 22 with such a resin material has an advantage of easy processing.

  The substrate 22 can also be formed of other materials such as glass. In this case, it may be treated with a silane coupling agent having a hydrophobic site such as dimethyldichlorosilane. Thus, similarly, the substrate 22 having the hydrophobic flow path surfaces 36 and 37 can be formed.

  3A and 3B are plan views of the liquid feeding device 20 according to the first embodiment of the present invention in an exploded manner. The surface of the substrate 22 on which the flow path portions 23 and 24 and the liquid reservoir portions 25 and 28 are formed as shown in FIG. 3A is turned over, and the valve electrode 31 and the operation electrode shown in FIG. 32, the reference electrodes 33 and 34, the wiring 33a, and the surface of the glass substrate 21 on which the wiring 35 is formed. At this time, the flow path surfaces 36 and 37 of the substrate 22 and the glass substrate 21 are arranged with a distance. In the present embodiment, the flow path surfaces 36 and 37 and the glass substrate 21 are arranged with a predetermined distance h. Thus, the liquid feeding device 20 is assembled and completed (see FIGS. 2A and 2B). By disposing the flow path surfaces 36 and 37 and the glass substrate 21 with a distance, the liquid delivery device 20 has a space between the flow path surfaces 36 and 37 and the glass substrate 21, that is, specifically. Is between the flow path surfaces 36, 37, the hydrophilic region on the glass substrate 21 at a position facing the flow channel surfaces 36, 37, and the valve electrode 31 provided alongside the hydrophilic region. Thus, the flow path 23 is formed.

  In the liquid delivery device 20 according to this embodiment of the present invention, the substrate 22 having the hydrophobic flow path surfaces 36 and 37 having the above-described configuration and the glass substrate 21 on which the valve electrode 31 and the like are formed are separately provided. It is produced. Then, as already described, the surface of the glass substrate 21 on which the valve electrode 31 and the like are formed and the surface of the substrate 22 on which the flow path portions 23 and 24 and the like are opposed are assembled and completed. At this time, in the liquid feeding device 20, the flow path portion 23 of the substrate 22 is formed in a concave shape, so that the flow path surfaces 36 and 37 and the glass substrate 21 are interposed as shown in FIG. More precisely, there is a distance between the flow path surfaces 36, 37 and the surface of the glass substrate 21, and specifically, they are arranged with a predetermined interval (distance) h.

  In FIG. 2 (b), the thickness of the valve electrode 31 is exaggerated, but actually, the thickness of the valve electrode 31 is so thin that the flow path surface 36 and the glass substrate need not be considered. The predetermined distance (distance) h between the surface 21 a of the 21 and the surface 21 a is considered to be the same as the distance (distance) between the flow path surface 36 and the upper surface of the valve electrode 31 formed on the glass substrate 21. Further, even when it is necessary to consider the thickness of the electrode formed on the glass substrate 21 such as the bulb electrode 31, if the distance between the surface 21a (upper surface) of the glass substrate 21 and the flow path surface 36 is determined, Since the distance between the upper surface of the electrode having a predetermined thickness on the glass substrate 21 and the flow path surface 36 is naturally determined, in this embodiment, the distance between the upper surface of the glass substrate 21 and the flow path surface 36 is used as a reference. Yes.

  In the present embodiment, the channel portions 23 and 24 of the substrate 22 are formed in a concave shape so as to be disposed with a gap (distance) between the channel surface 36 and the glass substrate 21. On the other hand, the channel portion may be formed flat or convex. That is, the substrate may be formed so that the flat surface of the flow path portion or the upper surface of the flow path portion formed in a convex shape becomes the flow path surface. In this case, for example, a spacer is inserted between the substrate on which the flow path portion is formed and the glass substrate 21, thereby providing a space (distance) between the flow path surface and the glass substrate 21. 20 is assembled. The configuration using the spacer has an advantage that the interval (distance) can be easily adjusted.

  Thus, the flow paths 23 and 24 are formed by having a distance between the flow path surfaces 36 and 37 and the glass substrate 21. In the present embodiment, a predetermined distance h is maintained between the flow path surfaces 36 and 37 and the glass substrate 21, but there is a flow path space between the flow path surfaces 36 and 37 and the glass substrate 21. It is only necessary to have a distance so as to be formed, and it is not limited to the case where the predetermined distance h is maintained. For example, when the distance between the flow path surface 36 and the glass substrate 21 is gradually decreased and the flow path space is narrowed, or the distance between the flow path surface 36 and the glass substrate 21 is gradually increased. For example, the flow path space may expand. As described above, the same is true in other embodiments to be described later, as long as the distance is sufficient so that the channel space is formed between the channel surface and the second substrate such as the glass substrate.

  Next, the operation of the liquid delivery device 20 according to the first embodiment of the present invention will be described with reference to FIGS. 4 and 5. 4 and 5 show a state where the fluid 40 to be fed is arranged in the liquid feeding device 20 shown in FIG. The fluid 40 is shown with diagonal lines in FIGS. FIG. 4B and FIG. 5B are side sectional views of the liquid feeding device 20. FIG. 4B and FIG. 5B also show a state in which the fluid 40 to be fed is arranged in the liquid feeding device 20.

  In the liquid feeding device 20, a fluid 40 to be fed is introduced from an introduction port 38 provided in the substrate 22. In the present embodiment, for example, a KCl solution is used as the fluid 40. The introduced fluid 40 is disposed between the substrate 22 and the glass substrate 21, specifically, between the liquid reservoir 25 formed on the substrate 22 and the glass substrate 21. At this time, the fluid 40 stored in the liquid reservoir 25 is in contact with the reference electrode 34 on the glass substrate 21 and the valve electrode 31, specifically, the end portion 31 a of the valve electrode 31. At this time, the fluid 40 also contacts the hydrophobic flow path surface 36 on the substrate 22, but the fluid 40 cannot exceed the flow path space 23 a sandwiched between the hydrophobic flow path surface 36 and the valve electrode 31. Stays on. (See FIGS. 4A and 4B).

  The electric potential of the valve electrode 31 is set within a range of electric potential that causes a change in interfacial tension due to adsorption of ions in the fluid 40, more desirably, adsorption of positive ions. The range of the potential that causes the change in the interfacial tension includes the distance between the flow path surface 36 of the liquid delivery device 20 and the glass substrate 21 (predetermined interval h in this embodiment), the material of the glass substrate 21 and the substrate 22, and the hydrophobicity. It depends on the degree of the property, the surface state of the flow path surface 36 and the valve electrode 31, and the like.

  In this state, the electrolytic solution 41 is introduced from the introduction port 39 provided in the substrate 22. In the present embodiment, for example, a KCl solution is used as the electrolytic solution 41. The introduced electrolytic solution 41 is disposed between the substrate 22 and the glass substrate 21, specifically, between the liquid reservoir 28 formed on the substrate 22 and the glass substrate 21. At this time, the electrolytic solution 41 stored in the liquid reservoir 28 flows through the flow path 24 while being in contact with the reference electrode 33 on the glass substrate 21. When the electrolytic solution 41 reaches the operation electrode 32 formed of zinc, a battery is formed by the silver / silver chloride electrode (reference electrode) 33, the electrolytic solution 41 and the operation electrode 32 of zinc, and the zinc The electric potential of the valve electrode 31 is changed to an appropriate negative value within the range of the electric potential causing the change in the interfacial tension by the electrical connection by the wiring 35. As a result, the valve electrode 31 is easily wetted. As a result, the fluid 40 spreads beyond the valve electrode 31, and the flow path space 23 a sandwiched between the hydrophobic flow path surface 36 and the valve electrode 31 and the flow path ahead. In other words, the flow path 23 sandwiched between the flow path surface 36 and the hydrophilic region of the glass substrate 21 moves (advances) by capillary action. In this way, the fluid 40 is fed (see FIGS. 5A and 5B).

  As described above, the fluid 40 is sent through the channel 23 sandwiched between the hydrophobic channel surface 36 and the valve electrode 31 as described above. When the potential of the zinc electrode 32 changes due to the electrical connection by the wiring 35 due to the battery action of the above, the interfacial tension between the valve electrode 31 and the fluid 40 (valve electrode 31-fluid 40 interface) is increased. This is because the fluid 40 tends to get wet on the valve electrode 31. By using the capillary phenomenon together as described above, the flow path 23 sandwiched between the flow path surface 36 and the hydrophilic region of the glass substrate 21 can be fed.

  It is the adsorption of ions to the electrode surface that affects the interfacial tension between the fluid 40 and the electrode including the valve electrode 31 (fluid 40-electrode interface). When the valve electrode 31 is changed to a more negative potential, the adsorption of cations on the electrode surface is dominant, and when the valve electrode 31 is changed to a more positive potential, the adsorption of anions on the electrode surface is dominant. Become.

  In the former case, that is, when the cation is adsorbed on the electrode surface by changing the valve electrode 31 to a more negative potential, the interface tension at the interface between the valve electrode 31 and the fluid 40 is not greatly affected by the type of ions. . The electrodes including the reference electrode 34 and the like are not affected (does not depend on the type of ions).

  On the other hand, in the latter case, that is, when the anion is adsorbed on the electrode surface by changing the valve electrode 31 to a more positive potential, the interfacial tension at the interface between the valve electrode 31 and the fluid 40 is greatly affected by the type of ions. coming out. Therefore, it is preferable to apply a negative voltage (potential) to the valve electrode 31 in order to perform liquid feeding with high reproducibility. Therefore, the operation electrode 32 is preferably made of a metal that becomes a negative electrode when a battery is formed.

  In addition, by setting the distance from the outlet 29 of the second liquid reservoir 28 of the operation electrode 32 to an appropriate distance, the time for the fluid to reach the operation electrode 32 according to the traveling speed of the fluid flowing through the flow path 24 is reduced. The time for opening the valve unit 27 in the flow path 23 can be adjusted.

  Next, a method for producing the liquid delivery device 20 according to the first embodiment will be described with reference to FIG.

  The method for manufacturing the liquid delivery device 20 includes a flow path and liquid reservoir forming step (step S11), an electrode and wiring forming step (step S12), and a substrate bonding step (step S13).

  The flow path and liquid reservoir forming step in step S11 is made of a material such as silicone rubber, acrylic, PET (polyethylene terephthalate), or a resin material made of PDMS (polydimethylsiloxane) (the substrate 22 is also referred to as a PDMS substrate). In the second substrate 22, concave flow paths 23, 24, a concave first liquid reservoir (reservoir) 25, a second liquid reservoir 28, and inlets 38, 39 are formed.

The electrode and wiring formation process of step S12 is as follows.
(1) A 200 nm-thick gold layer is formed on the substrate 21 by sputtering through a 40 nm chromium layer, for example.
(2) A positive photoresist is spin-coated on the substrate 21 on which the gold layer is formed, and baking is performed at 80 ° C. for 30 minutes.
(3) Through a photomask, after exposure with a mask aligner, development and rinsing are performed.
(4) The substrate 21 is immersed in a gold etching solution to remove the exposed gold layer. After washing with pure water and drying, the substrate 21 is immersed in acetone to dissolve and remove the photoresist, and then washed with acetone. Next, the substrate 21 is immersed in a chromium etching solution to remove the exposed portion of the chromium layer, washed with pure water, and then dried.
(5) Then, it is washed with pure water and dried. Thus, the valve electrode 31 is formed.
(6) In the same manner as described above, a gold layer that forms the base of the reference electrodes 33 and 34 is also formed on the upper surface of the substrate 21.
(7) A positive photoresist is spin-coated on the upper surface of the substrate 21 in the same manner as described above, followed by baking at 80 ° C. for 30 minutes, and then passing through a photomask and exposing with a mask aligner.
(8) After the substrate 21 is immersed in toluene and post-baked, the exposed photoresist is developed in a developer, rinsed with pure water, and dried.
(9) A silver layer having a film thickness of 400 nm, for example, is formed on the substrate 21 of (8) by sputtering.
(10) The substrate 21 is immersed in acetone, the photoresist is dissolved and removed, and washed with acetone. Thereby, the reference electrodes 33 and 34 are formed on the upper surface of the substrate 21.
(11) Further, the operation electrode 32 is formed by plating zinc.

  In the substrate bonding step in step S13, the two substrates formed in step S11 and step S12 are bonded together. For this, an adhesive can be used, or it can be sandwiched between two other substrates and fixed with light pressure. In this way, the liquid feeding device 20 can be manufactured.

  As described above, the liquid delivery device 20 according to the present embodiment has the two flow paths 23 and 24, and the first liquid reservoir 25 is provided at the end of one flow path 23, and the first A valve portion 27 is disposed on the outlet side of the liquid reservoir portion 25 to the flow path 23, and a second liquid reservoir portion 28 is provided at the end of the other flow path 24. In the liquid feeding device 20 in which the operation unit 30 is arranged at a predetermined distance from the outlet side to the flow path 24, the valve unit 27 includes a valve electrode 31 having an electrowetting action, and the operation unit 30 is There is an operation electrode 32 that changes its potential due to battery action when it comes into contact with the electrolyte, and the valve electrode 31 of the valve unit 27 and the operation electrode 32 of the operation unit 30 are electrically connected, so there is no external control. In addition, a liquid delivery device capable of autonomous liquid delivery control can be realized. .

  In the present embodiment, the same electrolytic solution is used for the liquid reservoirs 25 and 28, but liquid feeding may be performed using different electrolytic solutions.

  In this embodiment, a reference electrode such as a silver / silver chloride electrode is used. However, if the gold electrode is polarized due to a change in potential due to the battery action on the zinc electrode, the valve operation can be performed with this alone. It is expected that. Therefore, as shown in FIG. 7, there is no reference electrode, as shown in FIG. 8, a first modification in which the first liquid reservoir 25 and the second liquid reservoir 28 are connected by a flow path 28a, A similar experiment was attempted using a device having only a gold electrode and a zinc electrode without forming a silver / silver chloride electrode as in the second modification example in which there is no reference electrode and no flow path 28a. Liquid movement was observed. This indicates that automatic valve operation can be performed only with a simple electrode made of zinc and gold without using an external driving device such as a potentiostat.

  Next, a second embodiment of the present invention will be described. In the second embodiment, a plurality of valve electrodes and operation electrodes are alternately provided in the flow path. The same materials as those used in the liquid delivery device 20 of the first embodiment are used for the substrate and the electrode. Therefore, description of the constituent materials and the like is omitted.

  FIG. 9 is a plan view and a B-B ′ sectional view of the liquid delivery device according to the second embodiment of the present invention. The liquid feeding device 50 includes, for example, two flow paths 51 and 52 formed by the first substrate 21 and the second substrate 22. A first liquid reservoir 25 is provided at the end of one of the two channels 51 and 52. Valve portions 27-1, 27-2, 27-3 and operation portions 30-1, 30-2, 30-3 are alternately arranged on the outlet 26 side of the first liquid reservoir 25 to the flow path 51 in turn. Has been placed. A second liquid reservoir 28 is provided at the end of the other flow path 52. The operation units 30-4, 30-5, and 30-6 and the valve units 27-4, 27-5, and 27-6 are alternately arranged in this order from the outlet 29 side to the flow path 52 of the second liquid reservoir 28. Has been.

  The valve portions 27-1, 27-2, 27-3, 27-4, 27-5, and 27-6 include valve electrodes 31-1, 31-2, 31-3, 31-4, 31-5 and 31-6 are provided. The operation units 30-1, 30-2, 30-3, 30-4, 30-5, and 30-6 include operation electrodes 32-1, 32-2, 32-3, 32-4, and 32-5. 32-6 is provided. The valve electrode 31-1 and the operation electrode 32-4 are electrically connected by a wiring 35-1, and the valve electrode 31-4 and the operation electrode 32-1 are electrically connected by a wiring 35-2. The valve electrode 31-2 and the operation electrode 32-5 are electrically connected by a wiring 35-3, and the valve electrode 31-5 and the operation electrode 32-2 are electrically connected by a wiring 35-4. 31-3 and the operation electrode 32-6 are electrically connected by the wiring 35-5, and the valve electrode 31-6 and the operation electrode 32-3 are electrically connected by the wiring 35-6.

  Next, the operation of the liquid delivery device 50 according to the second embodiment of the present invention will be described with reference to FIGS. 10 to 13 show a state in which the fluid 40 to be fed is arranged in the liquid feeding device 50 shown in FIG. 9. The fluid 40 is indicated by hatching in FIGS. FIG. 9B to FIG. 13B are side sectional views of the liquid feeding device 50. 10 (b) to 13 (b) also show a state in which the fluid 40 to be fed is arranged in the liquid feeding device 50. FIG.

  In the liquid feeding device 50, a fluid 40 to be fed is introduced from an introduction port 38 provided in the substrate 22. In the present embodiment, for example, a KCl solution is used as the fluid 40. The introduced fluid 40 is disposed between the substrate 22 and the glass substrate 21, specifically, between the liquid reservoir 25 formed on the substrate 22 and the glass substrate 21. At this time, the fluid 40 stored in the liquid reservoir 25 is in contact with the end of the valve electrode 31-1. At this time, the fluid 40 also contacts the hydrophobic flow path surface 36 on the substrate 22, but the fluid 40 cannot exceed the flow path space 51 a sandwiched between the hydrophobic flow path surface 36 and the valve electrode 31. Stays on. (See FIGS. 10A and 10B).

  In this state, an electrolytic solution 40 to be fed is introduced from an introduction port 39 provided in the substrate 22. In the present embodiment, for example, a KCl solution is used as the electrolytic solution 40. The introduced electrolytic solution 40 is disposed between the substrate 22 and the glass substrate 21, specifically, between the liquid reservoir 28 formed on the substrate 22 and the glass substrate 21. At this time, the electrolytic solution 40 retained in the liquid reservoir 28 flows through the flow path 52. And if electrolyte solution reaches | attains the operation electrode 32-4 formed from zinc, the valve electrode 31-1 which consists of gold will be polarized by the change of the electric potential by the battery action on a zinc electrode. As a result, the valve electrode 31-1 is easily wetted. As a result, the fluid 40 extends beyond the valve electrode 31-1, and the flow path space 51 a sandwiched between the hydrophobic flow path surface 36 and the valve electrode 31-1. Inside and beyond the hydrophilic flow path, that is, the flow path space 51 sandwiched between the flow path surface 36 and the hydrophilic region of the glass substrate 21 moves (advances) by capillary action. In this way, the fluid 40 is fed (see FIGS. 11A and 11B).

  Next, the fluid 40 exceeding the operation electrode 32-4 of the flow path 52 is in a state of being in contact with the valve electrode 31-4 on the glass substrate 21, specifically, the end portion of the valve electrode 31-4. At this time, the fluid 40 also contacts the hydrophobic flow path surface 37 on the substrate 22, but the fluid 40 exceeds the flow path space 52b sandwiched between the hydrophobic flow path surface 37 and the valve electrode 31-4. It stays without being.

  In this state, the fluid 40 flows through the flow path 51. Then, when the electrolytic solution reaches the operation electrode 32-1 formed of zinc, the valve electrode 31-4 made of gold is polarized by a change in potential due to the battery action on the zinc electrode. As a result, the valve electrode 31-4 is easily wetted. As a result, the fluid 40 extends beyond the valve electrode 31-4, and the channel space 52b sandwiched between the hydrophobic channel surface 37 and the valve electrode 31-4. Inside and beyond the hydrophilic flow path, that is, the flow path space 52 sandwiched between the flow path surface 37 and the hydrophilic region of the glass substrate 21 moves (advances) by capillary action. In this way, the fluid 40 is fed (see FIGS. 12A and 12B).

  Furthermore, the fluid 40 that exceeds the operation electrode 32-1 of the flow path 51 is in a state of being in contact with the valve electrode 31-2 on the glass substrate 21, specifically, the end portion of the valve electrode 31-2. At this time, the fluid 40 also contacts the hydrophobic flow path surface 36 on the substrate 22, but the fluid 40 exceeds the flow path space 51b sandwiched between the hydrophobic flow path surface 36 and the valve electrode 31-2. It stays without being seen (see FIGS. 12A and 12B).

  In this state, the fluid 40 flows through the flow path 52. When the electrolytic solution reaches the operation electrode 32-5 made of zinc, the valve electrode 31-2 made of gold is polarized by a change in potential due to the battery action on the zinc electrode. As a result, the valve electrode 31-2 is easily wetted. As a result, the fluid 40 extends beyond the valve electrode 31-2, and the channel space 51b sandwiched between the hydrophobic channel surface 36 and the valve electrode 31-2. Inside and beyond the hydrophilic flow path, that is, the flow path space 51 sandwiched between the flow path surface 36 and the hydrophilic region of the glass substrate 21 moves (advances) by capillary action. In this way, the fluid 40 is fed (see FIGS. 13A and 13B).

  As described above, the fluid 40 is sent through the channel space sandwiched between the hydrophobic channel surface and the valve electrode as described above due to the change in potential due to the battery action by the electrolyte of the operation electrode. When the valve electrode is polarized and the potential is changed, the interfacial tension between the valve electrode and the fluid 40 (valve electrode-fluid interface) is decreased, and the fluid 40 is easily wetted on the valve electrode. Further, by using the capillary phenomenon together as described above, it is possible to send liquid in a flow path space sandwiched between the flow path surface and the hydrophilic region of the glass substrate 21.

  As described above, the valve electrodes 31-1, 31-2, 31-3, 31-4, 31-5, 31-6 provided in the flow paths 51, 52 are connected to the operation units 30-1, 30-2. , 30-3, 30-4, 30-5, and 30-6, the gold electrode is polarized by the change in potential due to the battery action by the electrolyte solution of the zinc electrode, and the potential can be changed to allow the fluid 40 to pass through. Thus, it is possible to realize a liquid delivery apparatus that can autonomously perform liquid delivery control without external control.

  The distances from the outlets 26 and 29 of the second liquid reservoirs 25 and 28 of the operation electrodes 32-1, 32-2, 32-3, 32-4, 32-5, and 32-6 are set to appropriate distances. Thus, the time for the fluid to reach the operation electrodes 32-1, 32-2, 32-3, 32-4, 32-5, and 32-6 according to the traveling speed of the fluid flowing through the flow paths 51 and 52 is set. The time for opening the valve portions 27-1, 27-2, 27-3, 27-4, 27-5, 27-6 in the flow paths 51, 52 can be adjusted. .

  In this embodiment, the reference electrode is not provided in the liquid reservoir, and the two liquid reservoirs are not connected by the flow path. However, the reference electrode is provided in the liquid reservoir as in the first embodiment. Even if it is provided, the same effect can be obtained. Further, the same effect can be obtained even if the two liquid reservoirs are connected by the flow path without providing the reference electrode as shown in the first modification of the first embodiment.

  Next, a third embodiment will be described. The third embodiment has at least one liquid reservoir, a flow path in which a valve portion is disposed on the outlet side of the liquid reservoir, and a flow path in which at least one operation portion extending from the liquid reservoir is disposed. . The materials for the substrate and electrodes are the same as those used in the first embodiment. Therefore, the description of the substrate and electrode materials constituting the apparatus is omitted.

  FIG. 14 is a plan view of a liquid delivery device according to the third embodiment of the present invention. The liquid feeding device 60 includes, for example, at least one liquid reservoir portion (five liquid reservoir portions 61 to 65 in FIG. 14) and liquid reservoir portions 62 to 65 formed by the first substrate 21 and the second substrate 22. A flow path 78 in which valve sections 66 to 69 are disposed on the outlet side and a flow path 78 in which at least one operation section (four operation sections 74 to 77 in FIG. 14) extending from the liquid reservoir section 61 is disposed. Have.

  The valve portions 66 to 69 are provided with valve electrodes 80 to 83, respectively, and the operation portions 74 to 77 are provided with operation electrodes 84 to 87, respectively. The valve electrode 80 and the operation electrode 84 are electrically connected by a wiring 90. The valve electrode 81 and the operation electrode 85 are electrically connected by a wiring 91. The valve electrode 82 and the operation electrode 86 are electrically connected by a wiring 92. The valve 83 and the operation electrode 87 are electrically connected by a wiring 93.

  Next, the operation of the liquid delivery device 60 according to the third embodiment of the present invention will be described with reference to FIGS. 15 to 17 show a state in which the fluid 40 to be fed is disposed in the liquid feeding device 60 shown in FIG. The fluid 40 is indicated by hatching in FIGS.

  In the liquid feeding device 60, the fluid 40 to be fed is introduced into the liquid reservoirs 61 to 65 provided on the substrate 22. In the present embodiment, for example, a KCl solution is used as the fluid 40. The introduced fluid 40 is disposed between the substrate 22 and the glass substrate 21, specifically, between the liquid reservoirs 61 to 65 formed on the substrate 22 and the glass substrate 21. At this time, the fluid 40 retained in the liquid reservoirs 62 to 65 is in contact with the valve electrodes 80 to 83, specifically, the end portions of the valve electrodes 80 to 83. At this time, the fluid 40 also comes into contact with the hydrophobic flow path surface on the substrate 22, but the fluid 40 flows in the flow paths of the valve portions 66 to 69 sandwiched between the hydrophobic flow path surface and the valve electrodes 80 to 83. You can't get past the space.

  In this state, the electrolytic solution 40 retained in the liquid reservoir 61 flows through the flow path 78. When the electrolytic solution 40 reaches the operation electrode 84 formed of zinc, the valve electrode 80 made of gold is polarized by a change in potential due to the battery action on the zinc electrode. As a result, the valve electrode 80 is easily wetted. As a result, the fluid 40 spreads beyond the valve electrode 80, and in the flow path space of the valve portion 66 sandwiched between the hydrophobic flow path surface and the valve electrode 80 and beyond. In the hydrophilic flow path, that is, the flow path 70 sandwiched between the flow path surface and the hydrophilic region of the glass substrate 21 is moved (advanced) by capillary action. In this way, the fluid 40 is fed (see FIG. 15).

  Next, in the liquid feeding device 60, the electrolytic solution 40 retained in the liquid reservoir 61 flows through the flow path 78. When the electrolytic solution 40 reaches the operation electrode 85 made of zinc, the valve electrode 81 made of gold is polarized by a change in potential due to the battery action on the zinc electrode. As a result, the valve electrode 81 is easily wetted. As a result, the fluid 40 spreads beyond the valve electrode 81, and in the flow path space of the valve portion 67 sandwiched between the hydrophobic flow path surface and the valve electrode 81 and beyond. In the hydrophilic channel, that is, the channel 71 sandwiched between the channel surface and the hydrophilic region of the glass substrate 21 is moved (advanced) by capillary action. In this way, the fluid 40 is fed (see FIG. 16).

  Further, in the liquid feeding device 60, the electrolytic solution 40 retained in the liquid reservoir 61 flows through the flow path 78. When the electrolytic solution 40 reaches the operation electrode 86 made of zinc, the valve electrode 82 made of gold is polarized by a change in potential due to the battery action on the zinc electrode. As a result, the valve electrode 82 is easily wetted. As a result, the fluid 40 spreads beyond the valve electrode 82, and in and beyond the flow path space of the valve portion 68 sandwiched between the hydrophobic flow path surface and the valve electrode 82. In the hydrophilic flow path, that is, the flow path 72 sandwiched between the flow path surface and the hydrophilic region of the glass substrate 21 is moved (advanced) by capillary action. In this way, the fluid 40 is fed (see FIG. 17).

  As described above, the fluid 40 is sent through the channel space sandwiched between the hydrophobic channel surface and the valve electrode as described above due to the change in potential due to the battery action by the electrolyte of the operation electrode. When the valve electrode is polarized and the potential is changed, the interfacial tension between the valve electrode and the fluid 40 (valve electrode-fluid interface) is decreased, and the fluid 40 is easily wetted on the valve electrode. Further, by using the capillary phenomenon together as described above, it is possible to send liquid in a flow path space sandwiched between the flow path surface and the hydrophilic region of the glass substrate 21.

  As described above, the valve electrodes 80 to 83 provided in the flow paths 70 to 73 can pass the fluid 40 by changing the potential when the electrolytic solution passes over the operation electrodes 84 to 87. Thus, it is possible to realize a liquid delivery apparatus that can autonomously perform liquid delivery control without external control.

  The operation electrodes 84, 85, 86, 87 are set at appropriate distances from the outlet of the liquid reservoir 61, so that the operation electrodes 84, 85, 86, The time required for the fluid to reach 87 can be adjusted, whereby the time for opening the valve portion 66 in the flow path 70, the time for opening the valve portion 67 in the flow path 71, and the valve portion in the flow path 72 can be adjusted. The time for opening 68 and the time for opening the valve unit 69 in the flow path 73 can be adjusted.

  Next, a fourth embodiment will be described. In the fourth embodiment, a valve portion and an operation portion are provided in contact with a part of the flow path. The same substrate and electrode as those used in the first embodiment are used. Therefore, description of the material of the substrate and the electrode of the device is omitted.

  FIG. 18 is a plan view of a liquid delivery device according to the fourth embodiment of the present invention. The liquid delivery device 100 includes liquid reservoirs 101, 102, and 103, and flow paths 101a, 102a, and 103a are provided from the liquid reservoirs 101, 102, and 103, respectively. The channel 101a and the channel 102a are connected to each other by a channel 106 provided with the valve unit 104 and the operation unit 105 in contact with each other. Further, a valve portion 107 is provided in the flow path 102a. Furthermore, the flow path 102a and the flow path 103a are connected to each other by a flow path 110 provided with a valve portion 108 and an operation portion 109 in contact with each other. Further, a valve portion 111 is provided in the flow path 103a.

  The valve electrode 104a of the valve unit 104 and the operation electrode 105a of the operation unit 105 are in contact with each other, and the valve electrode 107a of the valve unit 107 is electrically connected by the operation electrode 105a and the wiring 112. Further, the valve electrode 108 a of the valve unit 108 and the operation electrode 109 a of the operation unit 109 are in contact, and the valve electrode 111 a of the valve unit 111 is electrically connected by the operation electrode 109 a and the wiring 113. In the lower right part of FIG. 18, the valve unit 104 and the operation unit 105 are shown enlarged.

  Next, the effect | action of the liquid feeding apparatus 100 which concerns on 4th Embodiment of this invention is demonstrated with reference to FIGS. 19 to 21 show a state where the fluid 40 to be fed is arranged in the liquid feeding device 100 shown in FIG. The fluid 40 is indicated by hatching in FIGS.

  In the liquid feeding device 100, the fluid 40 to be fed is introduced from the inlet of the liquid reservoirs 101, 102, 103 provided on the substrate 22. In the present embodiment, for example, a KCl solution is used as the fluid 40. The introduced fluid 40 is disposed between the substrate 22 and the glass substrate 21, specifically, between the liquid reservoirs 101, 102, 103 formed on the substrate 22 and the glass substrate 21. At this time, the fluid 40 retained in the liquid reservoirs 102 and 103 is in contact with the end portions of the bulb electrodes 104a, 107a, 108a, and 111a on the glass substrate 21. The fluid 40 stays without exceeding the flow path space of the valve portions 104, 107, 108, 111 provided with the valve electrodes 104a, 107a, 108a, 111a. (See FIG. 19).

  In this state, the electrolytic solution 40 to be fed is introduced from the inlet of the liquid reservoir 101 provided on the substrate 22. In the present embodiment, for example, a KCl solution is used as the electrolytic solution 40. The introduced electrolytic solution 40 is disposed between the substrate 22 and the glass substrate 21, specifically, between the liquid reservoir 101 formed on the substrate 22 and the glass substrate 21. At this time, the electrolytic solution 40 retained in the liquid reservoir 101 flows through the flow path 101a. When the electrolytic solution reaches the operation electrode 105a formed of zinc, the valve electrode 104a made of gold is polarized by a change in potential due to the battery action on the zinc electrode. As a result, the valve electrode 104a and the valve electrode 107a are easily wetted. As a result, the fluid 40 spreads beyond the valve electrodes 104a and 107a, and in the flow path space of the valve portions 104 and 107 and in the hydrophilic flow path ahead. In other words, the channel space sandwiched between the channel surface and the hydrophilic region of the glass substrate 21 moves (advances) by capillary action. In this way, the fluid 40 is fed (see FIG. 20).

  Further, when the electrolytic solution 40 flows through the flow path 110 and reaches the operating electrode 109a made of zinc, the valve electrode 108a made of gold is polarized by a change in potential due to the battery action on the zinc electrode. . As a result, the valve electrode 108a and the valve electrode 111a are easily wetted. As a result, the fluid 40 spreads beyond the valve electrodes 108a and 111a, and in the flow path space of the valve portions 108 and 111 and in the hydrophilic flow path ahead. In other words, the channel space sandwiched between the channel surface and the hydrophilic region of the glass substrate 21 moves (advances) by capillary action. In this way, the fluid 40 is fed (see FIG. 21).

  As described above, the fluid 40 is sent through the channel space sandwiched between the hydrophobic channel surface and the valve electrode as described above due to the change in potential due to the battery action by the electrolyte of the operation electrode. When the valve electrode is polarized and the potential is changed, the interfacial tension between the valve electrode and the fluid 40 (valve electrode-fluid interface) is decreased, and the fluid 40 is easily wetted on the valve electrode. Further, by using the capillary phenomenon together as described above, it is possible to send liquid in a flow path space sandwiched between the flow path surface and the hydrophilic region of the glass substrate 21.

  As described above, the valve electrodes 104a, 107a, 108a, and 111a provided in the flow paths 102a, 103a, 106, and 110 are polarized by changing the potential due to the battery action by the electrolytic solution of the operation electrodes 105a and 109a. However, by changing the potential, the fluid 40 can be passed, and a liquid feeding device capable of autonomously performing liquid feeding control without external control can be realized.

  Note that by adjusting the distance from the outlet of the liquid reservoir 101 of the operation electrode 105a to an appropriate distance, the time for the fluid to reach the operation electrode 105a can be adjusted according to the traveling speed of the fluid flowing through the flow path 101a. Thus, the time for opening the valve portions 104 and 107 can be adjusted. In addition, by setting the distance of the operation electrode 109a from the valve portion 107 to an appropriate distance, the time for the fluid to reach the operation electrode 109a can be adjusted according to the traveling speed of the fluid flowing through the flow path 110. Thus, the time for opening the valve portions 108 and 111 can be adjusted.

  Next, a fifth embodiment will be described. In the fifth embodiment, there are two flow paths extending from two liquid reservoirs and a mixing part at the boundary between the two flow paths, and the operation is performed at a predetermined distance from a liquid reservoir different from the two liquid reservoirs. It consists of a channel having a section. The mixing unit includes a mixed electrode having an electrowetting action, and the operation unit includes an operation electrode whose potential changes due to a battery action when in contact with the electrolyte, and operates the mixing electrode and the operation unit of the mixing unit. The electrodes are electrically connected. The substrate and the operation electrode are made of the same material as that used in the first embodiment. Therefore, descriptions of the substrate and the materials constituting the operation electrode are omitted.

  One of the features that the liquid feeding device 200 according to the fifth embodiment is different from the liquid feeding device 20 according to the first embodiment is that a mixing electrode for mixing the fluid moving in the flow path space is provided. is there. The mixed electrode is an electrode having the same function as the valve electrode described in the first embodiment, but is an electrode used for the purpose of mixing a plurality of different fluids.

  FIG. 22 is a plan view of a liquid delivery device according to the fifth embodiment of the present invention. The liquid feeding device 200 includes, for example, two flow paths 203 and 204 extending from the two liquid reservoirs 201 and 202 and a mixing unit 205 at the boundary between the two flow paths. Further, the flow path 208 has an operation portion 207 at a predetermined distance from a liquid reservoir 206 different from the two liquid reservoirs 201 and 202.

  The mixing unit 205 is provided with a mixing electrode 210. The operation unit 207 is provided with operation electrodes 211. The mixed electrode 210 and the operation electrode 211 are electrically connected by a wiring 212.

  Next, the operation of the liquid delivery device 200 according to the fifth embodiment of the present invention will be described with reference to FIGS. 23 and 24 show a state in which fluids 250 and 251 to be fed are arranged in the liquid feeding device 200 shown in FIG. The fluids 250 and 251 are indicated by hatching in FIGS.

  In the liquid feeding device 200, fluids 250 and 251 to be fed and mixed are introduced from introduction ports 201 and 202 provided in the substrate 22. The introduced fluids 250 and 251 are disposed between the substrate 22 and the glass substrate 21, specifically, between the liquid reservoirs 201 and 202 formed on the substrate 22 and the glass substrate 21. At this time, the fluid 250 stored in the liquid reservoir 201 is in contact with the end 210 a of the mixed electrode 210 on the glass substrate 21. The fluid 250 remains without exceeding the flow path space of the mixing unit 205. In addition, the fluid 251 stored in the liquid reservoir 202 is in contact with the other end 210 b of the mixed electrode 210 on the glass substrate 21. The fluid 251 remains without exceeding the flow path space of the mixing unit 205. (See FIG. 23).

  In this state, the electrolytic solution 40 is introduced from the inlet of the liquid reservoir 206 provided on the substrate 22. In the present embodiment, for example, a KCl solution is used as the electrolytic solution 40. The introduced electrolytic solution 40 is disposed between the substrate 22 and the glass substrate 21, specifically, between the liquid reservoir 206 formed on the substrate 22 and the glass substrate 21. At this time, the electrolytic solution 40 retained in the liquid reservoir 206 flows through the flow path 208. When the electrolytic solution reaches the operation electrode 211 made of zinc, the mixed electrode 210 made of gold is polarized by a change in potential due to the battery action on the zinc electrode. As a result, the mixed electrode 210 is easily wetted. As a result, the fluid 250 and the fluid 251 spread beyond the mixed electrode 210, and the capillary phenomenon occurs in the channel space sandwiched between the hydrophobic channel surface and the mixed electrode 210. To move forward. In this way, the fluid 250 and the fluid 251 are mixed (see FIG. 24).

  In the liquid feeding device 200 of the fifth embodiment, the mechanism and driving method for feeding fluid to the flow path space sandwiched between the flow paths 203 and 204 and the flow path surface are the same as those of the liquid feeding device 20 of the first embodiment. is there.

  That is, the mixed electrode 210 has a role as a drive electrode for changing the electric potential and sending a fluid like the valve electrode, and is made of, for example, the same material as the valve electrode. Such a mixed electrode 210 can be easily formed just by changing the pattern of the photomask used for the glass substrate 21 as in the first embodiment.

  As described above, according to the liquid feeding device according to the fifth embodiment, when the potential of the mixing electrode 210 is changed by the operation electrode 211 electrically connected by the wiring 212, the fluid is automatically mixed. It is possible to realize a liquid feeding device that can autonomously perform liquid feeding control without external control.

  In addition, by adjusting the distance from the outlet of the liquid reservoir 206 of the operation electrode 211 to an appropriate distance, the time for the fluid to reach the operation electrode 211 can be adjusted according to the traveling speed of the fluid flowing through the flow path 208. Accordingly, the time for opening the mixing unit 205 can be adjusted.

  Of course, it is also possible to manufacture a liquid delivery device by appropriately combining the first to fifth embodiments described above.

  According to the present invention, by changing the electric potential of the valve electrode, it is possible to easily control the movement of the fluid by using the interfacial tension of the fluid and smoothly feed and discharge the fluid. For this reason, the structure of the conventional liquid delivery apparatus can be simplified.

  In each of the above embodiments of the present invention, the glass substrate 21 or the substrate 22 as the second substrate is sandwiched between the flow path surfaces of the concave flow path portions formed on the substrate 22 as the first substrate. The channel space was used as a channel through which a fluid was sent or discharged. On the other hand, as already described, the flow path portion is not necessarily formed in a concave shape in the first substrate. For example, a plane on the first substrate may be used as the flow path surface. In this case, a liquid feeding device is configured by the first substrate having a planar flow path surface and the second substrate on which a valve electrode or the like is formed. It is also conceivable to form a liquid feeding device with a first substrate having a channel portion formed in a convex shape and having an upper surface as a channel surface, and a second substrate on which a valve electrode or the like is formed.

  Next, an experiment performed on the liquid feeding device described in the second to fifth embodiments will be described. The structure shown in FIG. 9 was used as a liquid feeding device for confirming the principle. Two flow paths 51 and 52 were formed of a glass substrate 21 and a polydimethylsiloxane (PDMS) substrate 22. On the glass substrate 21, a zinc electrode, a silver / silver chloride electrode constituting a battery, and a gold electrode serving as a bulb were formed. Silver / silver chloride electrodes were formed at the solution inlets of the two channels, and zinc electrodes and gold electrodes were alternately formed in and between the channels. Six combinations were formed in which the zinc electrode in one channel and the gold electrode in the other channel were connected.

  A battery is formed by the zinc electrode and the silver / silver chloride electrode in one channel, and a potential is applied to the gold electrode. Thereby, the solution passes through the valve portion, and thereafter, formation of a battery and passage of the solution through the valve portion occur alternately.

  Next, in order to perform more complicated liquid feeding control, each element was simplified, and a device (liquid feeding apparatus) including only a gold electrode and a zinc electrode was also produced. Furthermore, in order to show the possibility of application to chemical analysis, a mechanism for mixing the solution filled in the two compartments in accordance with the progress of the solution flowing in another control channel was prepared. Further, a glucose solution and a solution containing glucose oxidase (GOD, 400 U / ml), horseradish peroxidase (HRP, 100 U / ml) and Amplex Red (1 mM) were mixed. The glucose concentration was determined.

  Next, the experimental results will be described. First, the function of the liquid delivery device in FIG. 9 was examined. When the solution was introduced into the flow channel 51 and reached the valve portion composed of the PDMS flow channel and the gold electrode, the solution stopped here (FIG. 10). Next, when the solution was introduced into the flow path 52 and passed through the zinc electrode, the solution that had been stationary in the flow path 51 passed through the valve portion and moved to the next valve (FIGS. 11 to 13). Thereafter, in the same manner, it was confirmed that the solutions in the two solutions proceed alternately.

  Experiments on the third embodiment shown in FIG. 14 to FIG. 17 are also performed, and sequential liquid feeding is performed in different channel networks, and the valves in the channels are sequentially opened in conjunction with the liquid feeding in the control channel. It was confirmed that Moreover, the experiment about 4th Embodiment shown in FIGS. 18-21 was also conducted, and the operation | movement of the valve part has been confirmed.

  Further, experiments were also conducted on the fifth embodiment shown in FIGS. A PDMS micropillar and a gold electrode (valve) were arranged at the center of the mixing region. Even when the compartments on both sides of the valve were filled with the solution, they did not pass through the valve section. However, when the solution reached the zinc electrode in the control channel and the battery was activated, the valve part became hydrophilic and the two solutions were mixed.

  As described above, according to the present invention, it is possible to realize a liquid delivery apparatus that can autonomously perform liquid delivery control without external control. And the liquid sending apparatus which can mix a several solution at the timing decided in the decided order, or can send to the following division is realizable. Thereby, the device (liquid feeding apparatus) which can perform the biosensing accompanying the process of a some solution is realizable.

  The configurations, shapes, sizes, and arrangement relationships described in the above embodiments are merely schematically shown to the extent that the present invention can be understood and implemented, and the numerical values and the compositions (materials) of the respective components Is just an example. Therefore, the present invention is not limited to the described embodiments, and can be variously modified without departing from the scope of the technical idea shown in the claims.

  The liquid delivery device according to the present invention is integrated by miniaturizing a laboratory such as medicine, basic research of biology such as local injection of an object, microanalysis system such as DNA and protein, and cell culture / separation detection. It is used for laboratory chips, sensors, microreactors, etc.

DESCRIPTION OF SYMBOLS 10 Glass substrate 11 Valve electrode 12 Droplet 13 Power supply 14 Switch 20 Liquid feeding device 21 1st board | substrate 22 2nd board | substrate 23 Flow path 24 Flow path 25 1st liquid reservoir part 26 Outlet 27 Valve part 28 2nd liquid Reservoir 29 Exit 30 Operation unit 31 Valve electrode 32 Operation electrode 33 Reference electrode 34 Reference electrode 35 Wiring 36 Channel surface 37 Channel surface 38 Inlet 39 Inlet 40 Fluid 50 Liquid feeder 60 Liquid feeder 100 Liquid feeder 200 Liquid feeder Device 205 Mixing unit 210 Mixing electrode

Claims (9)

Has two channels,
One end of the flow path is provided with a first liquid reservoir,
A valve portion is disposed on the outlet side of the first liquid reservoir to the flow path;
At the end of the other flow path, a second liquid reservoir is provided,
A liquid feeding device in which an operation unit is arranged at a predetermined distance from an outlet side to the flow path of the second liquid reservoir,
The valve portion includes a valve electrode having an electrowetting action,
The operation portion includes a hydrophilic operation electrode whose potential changes due to a battery action by being in contact with an electrolyte solution,
The liquid feeding device, wherein the valve electrode of the valve portion and the operation electrode of the operation portion are electrically connected. Has two channels,
One end of the flow path is provided with a first liquid reservoir,
Valve portions and operation portions are alternately arranged in order from the outlet side to the flow path of the first liquid reservoir portion,
At the end of the other flow path, a second liquid reservoir is provided,
In the liquid feeding device, the operation unit and the valve unit are alternately arranged in order from the outlet side to the flow path of the second liquid reservoir,
The valve portion includes a valve electrode having an electrowetting action,
The operation portion includes a hydrophilic operation electrode whose potential changes due to a battery action by being in contact with an electrolyte solution,
The liquid feeding device, wherein the valve electrode of the valve portion and the operation electrode of the operation portion, which are alternately arranged in each of the two flow paths, are electrically connected to each other. At least one liquid reservoir and a flow path having a valve portion disposed on the outlet side of the liquid reservoir;
A liquid feeding device provided with a flow path in which at least one operation unit extending from a liquid reservoir is disposed,
The valve portion includes a valve electrode having an electrowetting action,
The operation portion includes a hydrophilic operation electrode whose potential changes due to a battery action by being in contact with an electrolyte solution,
The liquid feeding device, wherein the valve electrode of the valve portion and the operation electrode of the operation portion are electrically connected to each other. A liquid feeding device provided with a valve portion and an operation portion in contact with a part of a flow path,
The valve portion includes a valve electrode having an electrowetting action,
The operation portion includes a hydrophilic operation electrode whose potential changes due to a battery action by being in contact with an electrolyte solution,
The liquid feeding device, wherein the valve electrode of the valve portion and the operation electrode of the operation portion are in contact with each other to make electrical connection. A flow path having two flow paths extending from two liquid reservoirs and a mixing part at the boundary between the two flow paths and an operation part at a predetermined distance from a liquid reservoir different from the two liquid reservoirs A liquid delivery device comprising:
The mixing unit includes a mixing electrode having an electrowetting action,
The operation portion includes a hydrophilic operation electrode whose potential changes due to a battery action by being in contact with an electrolyte solution,
The liquid feeding device, wherein the mixing electrode of the mixing unit and the operation electrode of the operation unit are electrically connected.   The liquid feeding device according to claim 1, wherein the valve electrode is made of gold.   The liquid feeding device according to claim 5, wherein the mixed electrode is made of gold.   The operation electrode is made of zinc, and a silver / silver chloride electrode is provided in the first liquid reservoir and the second liquid reservoir, and the silver / silver chloride electrode of the first liquid reservoir and the first The silver / silver chloride electrode of the liquid reservoir 2 is electrically connected, the electrolytic solution is put into the liquid reservoir, and the silver / silver chloride electrode and the operation electrode are immersed in the electrolytic solution to It forms, The liquid feeding apparatus of any one of Claims 1-7 characterized by the above-mentioned. The liquid flow feeding device according to claim 1, wherein the flow path is formed of a glass substrate and a polydimethylsiloxane (PDMS) substrate.

Images