JP2006220606A - Liquid sending device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize high-degree integration of a fine liquid-sending system having a simple structure, consuming very little power, and capable of performing efficiently a series of liquid-sending control including injection and discharge of fluid. <P>SOLUTION: This liquid sending device 11 is equipped with a substrate 2 which is the first substrate having a hydrophilic passage surface 3 having a hydrophobic domain 6 formed on a part thereof, a glass substrate 1 which is the second substrate wherein the position facing to the passage surface 3 is hydrophilic and a working electrode 4 is formed on a position facing to the hydrophobic domain 6, and a reference electrode 7. In the liquid sending device 11, the passage surface 3 and the working electrode 4 are arranged at a distance, and thereby a passage space 15 is formed between the passage surface 3 and the glass substrate 1, and in a state of a fluid 14 arranged between the substrate 2 and the glass substrate 1 and brought into contact with the reference electrode 7 and the working electrode 4, a potential difference is generated between the reference electrode 7 and the working electrode 4, to thereby control movement of the fluid 14 in the passage space 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus for controlling and feeding a small amount of fluid used in research fields such as chemistry, biology, medicine, material engineering, electrochemical engineering, semiconductor engineering, electronics, microchemical analysis, 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 a lab-on-a-chip (lab on a chip) that integrates a lab process (lab process) is being 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).
Japanese Patent Laid-Open No. 5-142198 (first page, FIG. 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 channel is, the greater the influence of interfacial tension and the like, and the resistance of the fluid flowing in the channel 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.

  The present invention solves the above problems, has a simple structure, consumes little power, can perform smooth liquid feeding even if the flow path is miniaturized, and in addition, sequentially It is an object of the present invention to realize a highly integrated micro liquid feeding system that can efficiently perform a series of liquid feeding control including injection and discharge of the fluid.

  In order to solve the above problems, the present invention has a hydrophilic flow path surface in which a hydrophobic region is formed in part, the first substrate, and the position facing the flow path surface is made hydrophilic. A second substrate on which a working electrode is formed at a position facing the hydrophobic region; and a reference electrode, and the flow path surface and the second substrate are arranged at a distance. Thus, a liquid delivery device in which a flow path space is formed between the flow path surface and the second substrate, wherein a fluid is disposed between the first substrate and the second substrate. In addition, the fluid moves in the flow path space by generating a potential difference between the reference electrode and the working electrode in a state where the fluid is in contact with the reference electrode and the working electrode. Provided is a liquid feeding device characterized by controlling the above.

  In the present invention, the first substrate having a hydrophilic channel surface partially formed with a hydrophobic region, the reference electrode is formed, and the position facing the channel surface is made hydrophilic. A second substrate on which a working electrode is formed at a position facing the hydrophobic region, and a distance between the flow path surface and the second substrate is disposed, A liquid delivery device in which a flow path space is formed between a flow path surface and the second substrate, wherein a fluid is disposed between the first substrate and the second substrate, and The fluid is controlled to move in the flow path space by causing a potential difference between the reference electrode and the working electrode in a state where the fluid is in contact with the reference electrode and the working electrode. Provided is a liquid feeding device characterized in that it is performed.

  According to the present invention, a first substrate having a hydrophilic channel surface partially formed with a hydrophobic region, a reference electrode, and a counter electrode are formed, and the position facing the channel surface is made hydrophilic. And a second substrate on which a working electrode is formed at a position facing the hydrophobic region, and the flow path surface and the second substrate are arranged with a distance. By the above, in the liquid feeding device in which a channel space is formed between the channel surface and the second substrate, a fluid is disposed between the first substrate and the second substrate, In addition, in the state where the fluid is in contact with the reference electrode, the counter electrode, and the working electrode, a potential difference is generated between the reference electrode and the working electrode, so that the fluid passes through the flow path space. Provided is a liquid feeding device characterized by controlling movement.

  It is preferable that an insulating layer is provided on the working electrode.

  The second substrate is preferably provided with a mixing electrode for mixing the fluid moving in the flow path space.

  The second substrate is preferably provided with a fluid discharge portion for discharging the fluid that moves in the flow path space.

  It is preferable that the potential of the working electrode is set within a range of potential that causes a change in interfacial tension due to adsorption of cations in the fluid.

  According to the liquid feeding device according to the present invention having the above-described configuration, it has a simple structure, consumes almost no electric power, and can carry out smooth liquid feeding even if the flow path is miniaturized. A highly integrated micro liquid feeding system capable of efficiently performing a series of liquid feeding control including fluid injection and discharge can be realized.

(principle)
One effective means for solving the problems of the present invention is to simplify as much as possible the structure and function of liquid feeding used in conventional micropumps and microvalves. In addition, if an electrochemical principle is used like the above-mentioned electroosmotic flow pump, it is advantageous as a solution method of the problem of simplifying the structure and function of these liquid feeding.

  Interfacial tension can be considered as one of the sources of resistance of the fluid flowing through the miniaturized flow path. However, the present inventors, on the contrary, can control the fluid feeding if this interfacial tension is used as the driving force for feeding the liquid, and in addition to the use of the capillary phenomenon, a very efficient liquid feeding mechanism is provided. I thought it could be realized. By the way, 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).

  Further, 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 the droplet 31 is placed on the substrate 34. The droplet 31 is, for example, an electrolytic solution. The substrate 34 is formed by providing, for example, a film layer 34b made of a polymer as an insulating layer on a metal substrate 34a made of gold, for example.

  In the case of FIG. 1, the substrate 34 on which the droplet 31 is placed and in contact, more precisely, the metal substrate 34a is called a working electrode (working electrode, driving electrode), and the droplet 31 is in contact with it. The other electrode is called a reference electrode (reference electrode, reference electrode) 33. In a state where the droplet 31 is placed on the substrate 34 and the droplet 31 is in contact with the reference electrode 33, a voltage is applied to the substrate 34, that is, the working electrode, so that the working electrode and the reference electrode 33 are interposed. Create a potential difference. 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 31 in a state in which a voltage is applied is more than the contact angle θ (see FIG. 1A) of the droplet 31 with respect to the substrate 34 before the voltage is applied. The contact angle θ ′ with respect to the substrate 34 (see FIG. 1B) becomes smaller. That is, when a voltage is applied, the substrate (working electrode) 34 is easily wetted.

  This is considered to be due to the following principle. As shown in FIG. 1B, the arrow 33a is the interfacial tension generated between the gas and the solid, the arrow 33b is the interfacial tension generated between the gas and the liquid, and the arrow 33c is between the solid and the liquid. It is the interfacial tension that occurs. When the potential of the substrate (working electrode) 34 is changed, the interfacial tension (arrow 33c) between the solid substrate 34 and the liquid droplet 31 (at the interface between the substrate 34 and the droplet 31) decreases. In other words, the substrate 34 is easily wetted by the droplets 31. Then, due to the interfacial tension between the gas and the solid (arrow 33a), the droplet 34 travels on the substrate 34 and is fed. When the voltage application is stopped and the potential is returned to the original state, liquid feeding stops.

  Note that the interfacial tension (arrow 33c) between the substrate 34 and the droplet 31 (at the interface between the substrate 34 and the droplet 31) affects the adsorption of ions in the droplet 31 to the surface of the substrate 34. 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. In FIG. 1, as an example of the insulating layer, a film layer (polymer layer) 34b made of a polymer is described as being provided on a metal substrate 34a as a working electrode. However, an insulating layer such as the film layer 34b made of this polymer is used. A similar change can occur even if is not provided on the working electrode.

  In principle, this electrowetting method consumes little power. Based on this electrowetting principle, the present inventors have invented a new liquid feeding device (mechanism) capable of smoothly controlling a series of liquid feeding including liquid feeding and discharging.

  The best mode for carrying out the liquid delivery device according to the present invention will be described with reference to the drawings based on the embodiments.

  FIGS. 2A and 2B are exploded plan views of the liquid delivery device 11 according to the first embodiment of the present invention. FIG. 2C is a virtual plan view seen from above the liquid delivery device 11 in which the substrate 2 in FIG. 2A and the glass substrate 1 in FIG. 2B are combined. FIG. 2D is an enlarged cross-sectional view of the vicinity of the flow path 13 obtained by cutting the liquid delivery device 11 of FIG. 2C along X-X ′.

  3A and 3B show a state in which the fluid 14 to be fed is arranged in the liquid feeding device 11 shown in FIG. The fluid 14 is indicated by hatching in FIGS. 3C and 3D are side cross-sectional views of the liquid feeding device 11. 3C and 3D also show a state in which the fluid 14 to be fed is arranged in the liquid feeding device 11.

  The liquid delivery device 11 includes a glass substrate 1 that is a second substrate on which electrodes are formed, and a substrate 2 that is a first substrate on which flow paths 13 are formed. In the present embodiment, a working electrode 4, a counter electrode 5, and a reference electrode 7 are formed on the glass substrate 1 as electrodes.

  In the substrate 2, the flow path portion 13 is formed in a concave shape and has a flow path surface 3. Specifically, the bottom surface of the elongated channel portion 13 formed in a concave shape is the channel surface 3.

  The flow path surface 3 is hydrophilic, but has a hydrophobic region 6 formed in part. On the glass substrate 1, the position facing the flow path surface 3 is hydrophilic, and the working electrode 4 is formed at a position facing the hydrophobic region 6.

  A concave liquid reservoir (reservoir) 10 is formed on the substrate 2. The liquid reservoir 10 is formed adjacent to the end 3d of the flow channel 13 having the flow channel surface 3 (see FIGS. 3C and 3D). The liquid reservoir 10 is for storing a fluid (solution, droplet, sample) 14 to be sent along the flow path surface 3. The liquid reservoir 10 is formed with an inlet 8 for introducing the fluid 14.

  The substrate 2 is made of, for example, a resin material, and materials such as silicone rubber, acrylic, and PET (polyethylene terephthalate) are conceivable. In this embodiment, the substrate 2 is formed of PDMS (polydimethylsiloxane) (the substrate 2 is also referred to as a PDMS substrate). In this case, the surface of the PDMS substrate near the position facing the working electrode 4 can be kept hydrophobic by protecting it during the oxygen plasma treatment. Thus, the substrate 2 having the hydrophilic flow path 3 in which the hydrophobic region 6 is partially formed can be formed. By forming the substrate 2 with such a resin material, there is an advantage that the processing is simple.

  In addition, the board | substrate 2 can also be formed with other materials, such as glass. In this case, contrary to the processing for the PDMS substrate, the portion that should be made hydrophilic is protected with a positive photoresist, and the portion that is not protected is a silane cup having a hydrophobic site such as dimethylchlorosilane. What is necessary is just to process with a ring agent. Thus, similarly, the substrate 2 having the hydrophilic flow path 3 in which the hydrophobic region 6 is partially formed can be formed.

  The surface 2a of the substrate 2 on which the flow path portion 13 and the liquid reservoir portion 10 are formed as shown in FIG. 2A is turned over, and the glass substrate 1 on which the electrode is formed as shown in FIG. It faces the surface 1a. At this time, the flow path surface 3 of the substrate 2 and the glass substrate 1 are arranged with a distance. In this embodiment, the flow path surface 3 and the glass substrate 1 are arranged with a predetermined distance h. Thus, the liquid feeding device 11 is assembled and completed (see FIGS. 2C and 2D). By disposing the flow path surface 3 and the glass substrate 1 at a distance, the liquid delivery device 11 has a space between the flow path surface 3 and the glass substrate 1, that is, specifically, the flow path surface. 3 and a hydrophilic region on the glass substrate 1 at a position facing the flow channel surface 3 and a working electrode 4 provided in parallel with the hydrophilic region, a flow channel space 15 is formed. The Rukoto.

  Actually, when the liquid feeding device 11 is formed by turning the surface 2a of the substrate 2 in FIG. 2A upside down and facing the surface 1a of the glass substrate 1 in FIG. 2B. In the plan view seen from above the liquid delivery device 11, the surface 2a of the substrate 2 cannot be seen. However, in order to facilitate understanding of the structure of the liquid delivery device 11, in FIG. 2C, in addition to the surface 1a of the glass substrate 1, it is assumed that the surface 2a of the substrate 2 on which the flow path surface 3 is formed is visible. Is displayed.

  A working electrode 4, a counter electrode 5, and a reference electrode 7 are formed on the glass substrate 1, and a three-electrode system (three-electrode system) is adopted. The three-electrode method is a method of measuring a current flowing between the working electrode 4 and the counter electrode 5 while applying a potential difference between the working electrode 4 and the reference electrode 7. The working electrode 4 is an electrode for applying a voltage, and is an electrode for generating a driving force for liquid feeding. The reference electrode 7 is an electrode serving as a potential reference. By adopting the three-electrode method, the current does not flow through the reference electrode 7 so that the potential of the reference electrode 7 serving as a potential reference is not shifted due to the influence of the current or the like. A potential difference can be accurately applied to the reference electrode 7.

  In the present embodiment, the three-electrode system is adopted, but the counter electrode 5 is not provided (the counter electrode 5 and the reference electrode 7 are integrated), and the working electrode 4 and the reference electrode 7 only (two-electrode system). May be adopted.

  The working electrode 4 and the counter electrode 5 are made of gold, for example. The working electrode 4 and the counter electrode 5 may be made of carbon or bismuth in addition to gold. In particular, the working electrode 4 is preferably formed of gold, carbon, or bismuth. This is because when a voltage is applied to the working electrode 4, hydrogen or the like is not generated and is not easily deteriorated. The reference electrode 7 is formed of an electrode substrate made of silver, a film layer made of silver chloride formed on the electrode substrate, and (hereinafter referred to as silver / silver chloride or Ag / AgCl). Thus, the reference electrode 7 is preferably formed of silver / silver chloride. By forming the reference electrode 7 with silver / silver chloride, there is an advantage that the potential of the reference electrode 7 does not change much even when a current is passed.

  As already described, the working electrode 4 is formed on the glass substrate 1 at a position facing the hydrophobic region 6 of the flow path surface 3 of the substrate 2. Further, the hydrophobic region 6 and the working electrode 4 are located in the vicinity of the liquid reservoir 10. The liquid reservoir 10 is formed adjacent to the end 3 d of the flow path 13, and the hydrophobic region 6 and the working electrode 4 are located in the vicinity of the liquid reservoir 10, so that the liquid is supplied to the liquid reservoir 10. In a state where the fluid 14 to be stored is stored, the end 3d of the flow path portion 13, and further the end 6a of the hydrophobic region 6 and the end 4a of the working electrode 4 are stored in the liquid storage 10. 14 (see FIGS. 3A and 3C).

  As shown in FIG. 2C, the reference electrode 7 and the counter electrode 5 are formed on the glass substrate 1 at positions facing the liquid reservoir 10 formed on the substrate 2. Therefore, the reference electrode 7 and the counter electrode 5 are located in the vicinity of the introduction port 8 through which the fluid (solution, droplet, sample) 14 is introduced. As a result, when the fluid 14 introduced from the introduction port 8 is stored in the liquid reservoir 10, the fluid 14 comes into contact with the reference electrode 7 and the counter electrode 5.

  In the present embodiment, the reference electrode 7 and the counter electrode 5 are formed on the glass substrate 1. However, if the fluid 14 to be fed stored in the liquid reservoir 10 can contact the reference electrode 7 and the counter electrode 5, However, it may not necessarily be formed on the glass substrate 1. For example, it may be formed on the substrate 2 or outside the glass substrate 1 and the substrate 2. More specifically, for example, the reference electrode 7 may be formed on the glass substrate 1 as the second substrate, the counter electrode 5 may be provided at a place other than the glass substrate 1, or both the reference electrode 7 and the counter electrode 5 may be provided on the glass substrate. You may provide in places other than one. This is the same in the case of the two-electrode system without the counter electrode 5, and the reference electrode 7 may be provided at a place other than the glass substrate 1 without being formed on the glass substrate 1.

  In the glass substrate 1, as described above, the position facing the flow path surface 3 is hydrophilic, but at least the peripheral portion 18 at the position facing the flow path surface 3 has a hydrophobic film layer. It may be formed. In the present embodiment, a hydrophobic film layer is formed on the peripheral portion 18 surrounding the position facing the working electrode 4 and the flow path surface 3 except for the position facing the liquid reservoir 10 in the glass substrate 1. Yes. This is because the fluid 14 that moves in the flow path space 15 beyond the working electrode 4 on the glass substrate 1 is reliably prevented from flowing outside the position facing the working electrode 14 and the flow path surface 3.

  In the liquid delivery device 11 according to this embodiment of the present invention, the substrate 2 having the hydrophilic flow path surface 3 partially formed with the hydrophobic region 6 having the above-described configuration, the working electrode 4 and the like are formed. The glass substrate 1 is manufactured separately. As described above, the surface 1a of the glass substrate 1 on which the working electrode 4 and the like are formed and the surface 2a of the substrate 2 on which the flow path portion 13 and the like are opposed are assembled and completed. At this time, in the liquid delivery device 11, since the flow path portion 13 of the substrate 2 is formed in a concave shape, as shown in FIG. 2D, between the flow path surface 3 and the glass substrate 1, more More precisely, there is a distance between the flow path surface 3 and the surface 1a of the glass substrate 1, and specifically, they are arranged with a predetermined distance (distance) h. In FIG. 2 (d), the thickness of the working electrode 4 is exaggerated, but in reality, the thickness of the working electrode 4 is so thin that it is not necessary to consider it. The predetermined distance (distance) h between the first surface 1 a and the surface 1 a is considered to be the same as the distance (distance) between the flow path surface 3 and the upper surface of the working electrode 4 formed on the glass substrate 1. Moreover, even when it is necessary to consider the thickness of the electrode formed on the glass substrate 1 such as the working electrode 4, if the distance between the surface 1a (upper surface) of the glass substrate 1 and the flow path surface 3 is determined, Since the distance between the upper surface of the electrode having a predetermined thickness on the glass substrate 1 and the flow path surface 3 is naturally determined, in this specification, the distance between the upper surface of the glass substrate 1 and the flow path surface 3 is used as a reference. Yes.

  In the present example, the channel portion 13 of the substrate 2 was formed in a concave shape so as to be disposed with a gap (distance) between the channel surface 3 and the glass substrate 1. 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 1, so that there is a space (distance) between the flow path surface and the glass substrate 1. 11 is assembled. The configuration using the spacer has an advantage that the interval (distance) can be easily adjusted.

  Thus, the flow path space 15 is formed by having a distance between the flow path surface 3 and the glass substrate 1. In the present embodiment, a predetermined distance h is maintained between the flow path surface 3 and the glass substrate 1, but a flow path space is formed between the flow path surface 3 and the glass substrate 1. Need only have a distance, and is not limited to the case where the predetermined distance h is maintained. For example, when the distance between the flow path surface 3 and the glass substrate 1 is gradually decreased and the flow path space is narrowed, or the distance between the flow path surface 3 and the glass substrate 1 is gradually increased. For example, the flow path space may expand. As described above, it is sufficient to have a distance so that a flow path space is formed between the flow path surface and the second substrate such as a glass substrate.

  When no voltage is applied to the working electrode 4, the fluid 14 in contact with the end portion 4 a of the working electrode 4 and the end portion 6 a of the hydrophobic region 6 is sandwiched between the working electrode 4 and the hydrophobic region 6. The flow path space 15 that has been created cannot be exceeded and remains. Here, when a voltage is applied to the working electrode 4, the working electrode 4 becomes easily wetted as already described in the above principle, and the fluid 14 in contact with the end portion 4 a spreads beyond the working electrode 4. Then, the fluid 14 that exceeds the working electrode 4 passes through the channel space 15 surrounded by the hydrophilic channel surface 3 formed in the concave channel part 13 and the hydrophilic region of the glass substrate 1 into the capillary. Due to the phenomenon, the liquid moves and is fed.

  In this way, by causing a potential difference between the reference electrode 7 and the working electrode 4, it is possible to control the movement of the fluid 14 through the flow path space 15. In addition, the distance between the flow path surface 3 and the glass substrate 1, in this embodiment, the predetermined distance h is the height of the flow path (flow path height, flow path interval) through which the fluid 14 moves and is fed. .

  As in this embodiment, in the liquid feeding device of the present invention for feeding liquid by electrowetting, an electrode for generating a driving force for liquid feeding, that is, a working electrode (working electrode, driving electrode) 4 is provided. It is provided at a position facing the hydrophobic region 6 formed in a part of the hydrophilic flow path surface 3 for the fluid to be fed. By forming in this way, the fluid can be temporarily retained by the hydrophobic working electrode 4 and the hydrophobic region 6 when no voltage is applied. On the other hand, by applying a voltage to the working electrode 4, the working electrode 4 can be easily wetted, and the fluid can be wetted and spread beyond the working electrode 4. 3 and the hydrophilic region of the glass substrate 1 can be easily controlled to feed the fluid in the flow path space.

(Function)
Next, the operation of the liquid delivery device 11 according to the present embodiment will be described. In the liquid feeding device 11, a fluid 14 to be fed is introduced from an introduction port 8 provided in the substrate 2. In this embodiment, for example, a KCl solution is used as the fluid 14. The introduced fluid 14 is disposed between the substrate 2 and the glass substrate 1, specifically, between the liquid reservoir 10 formed on the substrate 2 and the glass substrate 1. At this time, the fluid 14 retained in the liquid reservoir 10 is in contact with the counter electrode 5, the reference electrode 7, and the working electrode 4 on the glass substrate 1, specifically, the end portion 4 a of the working electrode 4. is there. At this time, the fluid 14 also contacts the end portion 6 a of the hydrophobic region 6 on the substrate 2, but the fluid 14 cannot pass through the flow path space 15 sandwiched between the hydrophobic region 6 and the working electrode 4. Stays on. (See FIGS. 3A and 3C).

  In this state, a voltage is applied to the working electrode 4 to generate a potential difference between the reference electrode 7 and the working electrode 4. The potential of the working electrode 4 is set within a range of potentials at which changes in the interfacial tension are caused by adsorption of ions in the fluid 14, more preferably by adsorption of cations. The range of potential that causes the change in the interfacial tension includes the distance between the flow path surface 3 of the liquid delivery device 11 and the glass substrate 1 (predetermined interval h in this embodiment), the material of the glass substrate 1 and the substrate 2, and the hydrophobicity. It depends on the degree of the property, the surface state of the flow path surface 3 and the working electrode 4 and the like.

  The potential of the working electrode 4 is changed to, for example, an appropriate negative value within the range of potential at which the change in interfacial tension is caused. Then, as a result of the working electrode 4 becoming easily wetted, the fluid 14 spreads beyond the working electrode 4, and the hydrophilic flow path in the flow path space 15 sandwiched between the hydrophobic region 6 and the working electrode 4 and beyond. Inside, that is, the flow path space 15 sandwiched between the flow path surface 3 and the hydrophilic region of the glass substrate 1 moves (advances) by capillary action. In this way, the fluid 14 is fed (see FIGS. 3B and 3D).

  As described above, the fluid 14 is sent through the flow path space 15 sandwiched between the hydrophobic region 6 and the working electrode 4 as described above when the voltage is applied to the working electrode 4. This is because the interfacial tension between the fluid 14 and the fluid 14 (working electrode 4 -fluid 14 interface) is lowered, and the fluid 14 is easily wetted on the working electrode 4. Further, by using the capillary phenomenon together as described above, the flow path space 15 sandwiched between the flow path surface 3 and the hydrophilic region of the glass substrate 1 can be fed.

  It is the adsorption of ions on the electrode surface that affects the interfacial tension between the fluid 14 and the electrode including the working electrode 4 (fluid 14-electrode interface). When the working electrode 4 is changed to a more negative potential, adsorption of cations on the electrode surface is dominant, and when the working electrode 4 is changed to a more positive potential, adsorption of anions on the electrode surface is dominant. Become.

  In the former case, that is, when the working electrode 4 is changed to a more negative potential and the cation is adsorbed on the electrode surface, the interface tension at the interface between the working electrode 4 and the fluid 14 is not greatly affected by the type of ions. . The electrodes including the reference electrode 7 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 working electrode 4 is changed to a more positive potential and an anion is adsorbed on the electrode surface, the interfacial tension at the interface between the working electrode 4 and the fluid 14 is greatly affected by the type of ions. coming out. Therefore, it is preferable to apply a negative voltage (potential) to the working electrode 4 in order to perform liquid feeding with high reproducibility.

  Further, according to the present invention, the current value generated by applying a voltage to the working electrode 4 is typically on the order of μA, and the power consumption value is also on the order of μW. By further miniaturization, it can be further reduced. These current values and power consumption values are very small compared to the case of using a conventional micropump or the like. The source of the current value is the Faraday current accompanying the reduction of oxygen or the like, or the charging current of the electric double layer. The height of the flow path (flow path height, flow path spacing, flow path surface 3 and glass substrate 1 The power consumption can also be reduced by adjusting the distance between them, in the case of this embodiment, the predetermined interval h) to lower the drive potential.

  The liquid feeding device 61 according to the second embodiment of the present invention is similar to the configuration of the liquid feeding device 11 of the first embodiment, and the same components as those of the liquid feeding device 11 of the first embodiment are denoted by the same reference numerals. The illustration and description are omitted. Also, description of the same operations and effects as those of the first embodiment is omitted.

  4A and 4B are plan views of the liquid feeding device 61 according to the second embodiment of the present invention. The surface 2a of the substrate 2 on which the flow path surface 3 and the like shown in FIG. 4 (b) are formed is turned over so as to face the surface 1a of the glass substrate 1 shown in FIG. 4 (a). Thus, the liquid feeding device 61 is assembled and completed. FIG. 4C is an enlarged cross-sectional view of the completed liquid delivery device 61 in the vicinity of the flow path cut by X-X ′ in FIGS. 4A and 4B. 4D and 4E are enlarged cross-sectional views of the glass substrate 1 in the vicinity of the flow path cut along X-X ′ and Y-Y ′ in FIG.

  FIGS. 5A and 5B are schematic plan views showing a state in which the fluid to be fed is arranged in the liquid feeding device 61 shown in FIG. Also in FIG. 5, in order to facilitate understanding of the structure of the liquid feeding device 61, the surface 1 a of the glass substrate 1 is virtually displayed as being visible. In FIG. 5, fluids to be sent are indicated by hatching.

  One of the features that the liquid feeding device 61 according to the second embodiment is different from the liquid feeding device 11 according to the first embodiment is that a mixing electrode 62 for mixing the fluid moving in the flow path space 15 is provided. is there. The mixed electrode 62 is an electrode having the same function as the working electrode 4 described in the first embodiment, but is an electrode used for mixing a plurality of different fluids.

  In the liquid delivery device 61, a plurality of hydrophilic flow paths, in this embodiment, two flow paths 64a and 64b are formed on the glass substrate 1. These flow paths 64 a and 64 b are hydrophilic regions at positions facing the flow path surface 3 on the substrate 2. An inlet 8 for injecting fluid is provided at each end of each flow path 64a, 64b. Further, as in the first embodiment, the reference electrode 7 and the counter electrode 5 (not shown in FIG. 4, both refer to FIG. 2C) are formed. The reference electrode 7 and the counter electrode 5 may be provided at any place on the glass substrate 1 or at a place other than the glass substrate 1 as long as the place is in contact with the fluid. Further, as described in the first embodiment, the counter electrode 5 and the reference electrode 7 may be integrated to adopt a two-electrode system (two-electrode system).

  On the glass substrate 1, elongated mixed electrodes 62 are formed where the channels 64 a and 64 b extending in parallel intersect each other (see FIG. 4A). On the other hand, the substrate 2 is made of PDMS, for example, similarly to the first embodiment, and a hydrophobic region 6 is formed in a part thereof (see FIG. 4B). The substrate 2 can be formed of a material other than PDMS, for example, glass, as described in the first embodiment. The mixed electrode 62 is disposed at a position on the glass substrate 1 facing the hydrophobic region 6 formed in a part of the flow path surface 3 of the substrate 2. (See FIG. 4 (c)). Accordingly, the mixed electrode 62 is disposed on the glass substrate 1 at a position where the flow passage spaces 15 sandwiched between the flow passages 64 a and 64 b and the flow passage surface 3 meet. In order to adjust the ease of mixing, the hydrophobic region 6 on the substrate 2 can be protruded from the surroundings, or conversely recessed.

  In the glass substrate 1, the position facing the flow path surface 3 is made hydrophilic, but at least the peripheral portion 18 at the position facing the flow path surface 3 is formed with a hydrophobic film layer to form a hydrophobic region. To be. In the present embodiment, in the glass substrate 1, the peripheral portion 18 surrounding the introduction port 8, the flow paths 64 a and 64 b, and the mixing electrode 62 is formed into a hydrophobic region in which a hydrophobic film layer is formed ( (See FIGS. 4A, 4D, and 4E). This is because the fluid that moves in the flow path space 15 beyond the working electrode 4 on the glass substrate 1 is surely prevented from flowing outside the flow paths 64 a and 64 b and the mixing electrode 62.

  In the liquid feeding device 61 of the present embodiment, the mechanism and driving method for feeding fluid to the flow path space 15 sandwiched between the flow paths 64a and 64b and the flow path surface 3 are the same as those of the liquid feeding apparatus 11 of the first embodiment. is there.

  That is, the mixed electrode 62 has a role as a drive electrode that applies a voltage and feeds fluid, similarly to the working electrode 4 (for example, see FIG. 3 of the first embodiment). Made of material. Such a mixed electrode 62 can be easily formed in the same manner as in the first embodiment only by changing the pattern of the photomask used for the glass substrate 1.

  In the liquid feeding device 61, when a plurality of fluids are introduced from the respective inlets 8, the flow paths 64a and 64b are hydrophilic. Therefore, each fluid spontaneously passes through the flow paths 64a and 64b due to capillary action. Spread and proceed. Each fluid comes into contact with both peripheral ends of the mixing electrode 62 (see FIG. 5A). In a state where no voltage is applied to the mixed electrode 62, the fluid remains in contact with both peripheral ends of the mixed electrode 62. Here, when a voltage is applied to the mixed electrode 62, the mixed electrode 62 is easily wetted, and each fluid that has been in contact with both peripheral ends of the mixed electrode 62 spreads and mixes on the mixed electrode 62 ( (Refer FIG.5 (b)). In this way, each fluid can be fed onto the mixing electrode 62 and can be mixed on the mixing electrode 62.

  It should be noted that the present embodiment and the first embodiment can be implemented in combination. At that time, for the working electrode 4 as described in the first embodiment, the reference electrode 7 and the counter electrode 5 provided in the vicinity of the liquid reservoir 10 are fed to the mixing electrode 62 to be mixed. It can also be used. In this case, the reference electrode 7 and the counter electrode 5 are used to send the fluid once retained beyond the working electrode 4. When the fluid is mixed on the mixing electrode 62, the mixing electrode 62 is used. 62 is used by switching. Alternatively, a reference electrode and a counter electrode for the mixed electrode 62 may be separately formed in the vicinity of the mixed electrode 62. Further, as with the working electrode, the mixed electrode 62 may of course employ a two-electrode system in which the reference electrode and the counter electrode are integrated.

(Function)
The operation of the second embodiment will be briefly described with reference to FIG. When, for example, different types of fluids are injected from the introduction ports 8 of the liquid feeding device 61, the injected fluids spontaneously spread through the hydrophilic flow paths 64a and 64b by capillary action. In this way, each fluid is sent to the vicinity of the mixing electrode 62. Each fluid that has been sent remains in contact with both peripheral ends of the mixing electrode 62 (FIG. 5A).

  In this state, when a potential (voltage) is applied to the mixed electrode 62, the fluids that remain in contact with both peripheral ends of the mixed electrode 62 spread and mix on the mixed electrode 62. FIG. 5B shows a mixed fluid 64.

  The liquid feeding device 91 according to the third embodiment of the present invention is common to the principle of the liquid feeding device 11 of the first embodiment, and the same components as those of the liquid feeding device 11 of the first embodiment are denoted by the same reference numerals. The illustration and description are omitted. Also, the description of the same operation and effect as those in Examples 1 and 2 is omitted. FIG. 6A is a plan view of a substrate 81 constituting a liquid feeding device 91 according to Embodiment 3 of the present invention, and FIG. 6B is a plan view of the liquid feeding device 91 according to Embodiment 3 of the present invention. It is a partial sectional side view.

  One of the features of the liquid feeding device 91 according to the third embodiment which is different from the liquid feeding devices 11 and 61 of the first and second embodiments is that a fluid discharge portion 92 for discharging the fluid moving in the flow path space 15 is provided. Is to be. The fluid discharge unit 92 includes a through hole 93 formed in the substrate 81 which is the second substrate, and a working electrode 94 provided at least on the side wall 93 a of the through hole 93. More preferably, the fluid discharge unit 92 has a through-hole 93 formed in the substrate 81 as the second substrate and means for absorbing fluid provided in the lower portion of the substrate 81, specifically, in the lower portion of the substrate 81. A porous material 95 that is in close contact, and a working electrode 94 provided on at least the side wall 93a of the through-hole 93 are provided. In this embodiment, the working electrode 94 is provided on the side wall 93 a of the through hole 93 and the lower surface 81 a of the substrate 81.

  The porous material 95 can be accommodated in the container 96 below the substrate 81. Examples of the porous substance 95 include a hydrophilic mesh and filter paper. The porous material 95 is used for sucking a fluid, and is not necessarily limited to a porous material as long as it plays a role as a means for sucking a fluid. The container 96 is made of, for example, plastic, glass, acrylic, PET, silicone rubber, polyethylene, or the like.

  The counter electrode 5 and the reference electrode 7 are provided on the upper surface 81b of the substrate 81, which is the second substrate (see FIGS. 6A and 6B). On the other hand, the substrate 2, which is the first substrate, is made of, for example, PDMS in the same manner as in the first embodiment, and has a concave flow path portion 13 (however, the flow path portion 13 is not shown in FIG. 6). The flow path part 13 of FIG. 2 of Example 1 which is a structure is formed. In the channel space 15, the surface of the substrate 2 facing the upper surface 81 b of the substrate 81, that is, the channel surface that is the bottom surface of the concave channel part 13 is made hydrophilic. In the same manner as in the first embodiment, the substrate 2 is combined with the upper surface 81b of the substrate 81 provided with the fluid discharge portion 92 so that the surface on which the flow path portion 13 is formed, and the liquid feeding device 91 is completed. .

In the liquid feeding device 91, a substrate 81 is produced using an acrylic plate as the second substrate instead of the glass substrate 1 (see Examples 1 and 2). The use of an acrylic plate has the advantage that the through holes can be easily formed. In this embodiment, the substrate 81 is manufactured using an acrylic plate. However, the substrate 81 is not limited to the acrylic plate as long as it is hydrophilic (or can be made hydrophilic) and can form a through hole. Also in the present embodiment, the substrate 81 may be manufactured using glass, for example, as in the first and second embodiments, or a substrate having a glass (SiO ₂ ) layer formed on the surface thereof. FIG. 7 shows a manufacturing process of the substrate 81.

A manufacturing process of the substrate 81 will be described with reference to FIGS.
(1) First, a through hole 93 is formed in a substrate 81 made of acrylic (FIG. 7A). The through hole 93 has a diameter of about 0.5 mm, for example, and then the substrate 81 is cleaned in acetone.
(2) A chromium layer having a thickness of 40 nm, for example, a gold layer having a thickness of 200 nm is formed on the substrate 81 by sputtering. Thereby, a thin film of a gold layer is also formed on the side wall 93 a in the through hole 93.
(3) A positive photoresist is spin-coated on the substrate 81 on which the gold layer is formed, and baking is performed at 80 ° C. for 30 minutes.
(4) Through a photomask, after exposure with a mask aligner, development and rinsing are performed.
(5) The substrate 81 is immersed in a gold etching solution to remove the exposed gold layer. After washing with pure water and drying, the substrate 81 is immersed in acetone to dissolve and remove the photoresist, and then washed with acetone.
(6) The substrate 81 is immersed in a chromium etching solution to remove the exposed portion of the chromium layer. Then, it is washed and dried with pure water. Thus, the working electrode 94 is formed (FIG. 7B).
(7) Similarly to the above, the base layer of the reference electrode 7 and the gold layer constituting the counter electrode 5 are formed on the upper surface 81 b of the substrate 81.
(8) A positive photoresist is spin-coated on the upper surface 81b of the substrate 81 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.
(9) The substrate 81 is immersed in toluene and post-baked, and then the exposed photoresist is developed in a developer, rinsed with pure water, and dried.
(10) A silver layer having a thickness of, for example, 400 nm is formed on the substrate 81 of (9) by sputtering.
(11) The substrate 81 is immersed in acetone, the photoresist is dissolved and removed, and washed with acetone. As a result, the reference electrode 7 is formed on the upper surface 81 b of the substrate 81.

  In the configuration of this embodiment, the fluid 104 fed through the flow path space 15 can be discharged using the fluid discharge portion 92 by using the principle of the present invention described above. That is, when the fluid 104 is present in the flow path space 15, the fluid 104 is discharged from the through hole 93 because the side wall 93 a of the through hole 93 is hydrophobic when no voltage is applied to the working electrode 94. Instead, it remains in the flow path space 15. Here, when a voltage is applied to the working electrode 94, the working electrode 94 is easily wetted. The fluid 104 wets and spreads on the working electrode 94 that is easily wetted, in other words, the side wall 93a of the through hole 93a that is easily wetted, and flows out from the through hole 93 to the lower portion of the substrate 81. The fluid 104 that has flowed out is sucked by the porous material 95 that is in close contact with the lower portion of the substrate 81, and the fluid 104 can be discharged.

  FIG. 8 is a side cross-sectional view of the liquid feeding device 91 and shows a state where the fluid 104 is discharged. The operation of the present embodiment will be briefly described with reference to FIG. The flow path space 15 of the liquid delivery device 91 is in a state of being filled with the fluid 104 (FIG. 8A). In a state where the working electrode 94 is not applied, the side wall 93a of the through hole 93 is in a hydrophobic state, so that the fluid 104 cannot flow out of the through hole 93 and remains in the flow path space 15.

  Next, a voltage is applied to the working electrode 94. As a result, the side wall 93a of the through hole 93 is easily wetted, and the fluid 104 in the flow path space 15 wets and spreads the side wall 93a, passes through the through hole 93, and is provided in close contact with the lower portion of the substrate 81. The substance 95 oozes out (FIG. 8B).

  The porous substance 95 vigorously sucks the fluid 104, and the fluid 104 in the flow path space 15 is sucked by the porous substance 95. Thus, the fluid 104 is discharged from the flow path space 15 (FIG. 8C).

  In the present embodiment, the reference electrode 7 and the counter electrode 5 are formed on a surface (upper surface 81 b) different from the working electrode 94. As a result, there is an advantage that no adverse effect is exerted on the liquid feeding of the fluid traveling in the flow path space 15 along the upper surface 81 b of the substrate 81. On the other hand, unlike the present embodiment, the reference electrode 7, the counter electrode 5, and the working electrode 94 may be formed on the same surface. In this case, the working electrode 94 is formed only in the region of the side wall 93 a of the through hole 93. Thereby, when a fluid is sent in the flow path space 15, it can be made not to have a bad influence.

  In this embodiment, the porous material 95 is in close contact with the lower portion of the substrate 81 as the structure of the fluid discharge portion 92. However, this is only an example of discharging the fluid. The configuration is not limited.

(Modification)
It is also possible to combine a plurality of liquid feeding devices 91 described in the third embodiment. FIG. 9 is a schematic plan view of a liquid feeding device 101 according to a modification of the liquid feeding device 91 according to the third embodiment. Also in FIG. 9, in order to facilitate understanding of the structure of the liquid delivery device 101, a state where the second substrate on which the counter electrode 5, the reference electrode 7, and the through-hole 93 are formed is virtually shown.

  The liquid feeding device 101 is connected by combining a plurality of liquid feeding device portions 91a to 91c similar to the liquid feeding device 91 of the third embodiment, and at one end of each of the liquid feeding device portions 91a to 91c, The fluid inlet 8 as described in the first embodiment is provided. Furthermore, the reaction compartment 102 in which a plurality of fluids are mixed at the other end of the liquid delivery device portions 91a to 91c, that is, the end of each of the liquid delivery device portions 91a to 91c on the side opposite to the introduction port 8. Is formed. More specifically, the reaction compartment 102 is provided at a location where each of the liquid delivery device portions 91a to 91c is connected, in other words, at a location where each fluid sent by each of the liquid delivery device portions 91a to 91c meets, Is formed.

  About the effect | action and effect of liquid feeding apparatus part 91a-91c, since it is the same as that of the liquid feeding apparatus 91 of Example 3, description is abbreviate | omitted. If the liquid feeding device 101 having such a configuration is used, a plurality of fluids are sequentially injected from the introduction port 8, for example, are fed through the flow paths of the liquid feeding device portions 91 a to 91 c by capillary action, and are discharged from the through holes 93. In addition, only the necessary fluid can be sent to the reaction compartment 102. Furthermore, unnecessary fluid after mixing in the reaction compartment 102 can be discharged from the through-hole 93, and a series of liquid supply systems including liquid injection, liquid supply, and discharge can be easily constructed. it can.

  In addition to the above-described modification, it is of course possible to manufacture a liquid feeding device in which the above-described first to third embodiments are appropriately combined.

  In each of the above embodiments and modifications, the fluid is brought into direct contact with the working electrode made of metal such as gold. However, in each of the above embodiments and modifications, the principle (see FIG. 1) is already described. As described above, the same effect can be obtained even when the insulating layer is provided on the working electrode and a fluid is brought into contact with the insulating layer. In addition, in this specification, the meaning of bringing fluid into contact with the working electrode means that the fluid is brought into contact with the working electrode indirectly through an insulating layer provided on the working electrode, as well as when the fluid is brought into direct contact with the working electrode. It is also included in the case of This is because the actions and effects of the present invention are similarly generated.

  According to the present invention, by applying a potential to the working electrode, it is possible to easily control the movement of the fluid using the interfacial tension of the fluid, and to smoothly feed and discharge the fluid. This eliminates the need for a check valve (check valve) to prevent the backflow of fluid, which was necessary when liquid was fed using a conventional mechanical micropump or microvalve, and was complicated in the past. In addition, the structure of the liquid delivery device can be simplified.

  In each of the above embodiments of the present invention, the glass substrate 1 or the substrate 81 as the second substrate and the flow path surface 3 of the concave flow path portion 13 formed on the substrate 2 as the first substrate. The sandwiched channel space 15 was used as a channel through which fluid was sent or discharged. On the other hand, as already described, the flow path portion 13 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 the working electrode and the like are 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 working electrode and the like are formed.

  The best mode of the liquid delivery device according to the present invention has been described based on the embodiments. However, the present invention is not particularly limited to such embodiments, and the scope of the technical matters described in the claims. It goes without saying that there are various embodiments within.

  Examples of the use of the present invention include miniaturization and integration of laboratories for medical and basic research such as local injection of objects, microanalysis systems such as DNA and proteins, and cell culture / separation detection. Laboratory chips, sensors, microreactors and the like.

It is a schematic diagram which shows the principle of electrowetting. FIGS. 2A and 2B are exploded plan views of the liquid delivery device according to the first embodiment of the present invention, and FIG. 2C shows the substrate 2 in FIG. 2A and FIG. 2B. FIG. 2D is a virtual plan view seen from above when combined with the glass substrate 1 of FIG. 2. FIG. 2D is a flow obtained by cutting the liquid delivery device 11 of FIG. It is an expanded sectional view near a road part. 3 (a) and 3 (b) show a state in which the fluid to be fed is arranged in the liquid feeding device 11 shown in FIG. 2 (c). FIGS. 3 (c) and 3 (d) These are sectional side views of the liquid feeding apparatus which concerns on Example 1. FIG. 4 (a) and 4 (b) are exploded plan views of the liquid feeding device according to the second embodiment of the present invention, and FIG. 4 (c) shows the completed liquid feeding device in FIG. 4 (b). 4D is an enlarged cross-sectional view of the vicinity of the flow path cut along XX ′. FIGS. 4D and 4E show the glass substrate 1 cut along XX ′ and YY ′ in FIG. It is an expanded sectional view of the flow path vicinity. FIGS. 5A and 5B are schematic plan views showing a state in which the fluid to be fed is arranged in the liquid feeding device shown in FIG. FIG. 6A is a plan view of a substrate constituting the liquid feeding device according to the third embodiment of the present invention, and FIG. 6B is a partial view of the liquid feeding device according to the third embodiment of the present invention. It is a sectional side view. It is a figure which shows the preparation process of the board | substrate of the liquid feeding apparatus which concerns on Example 3. FIG. It is a partial sectional side view of the liquid feeding apparatus which concerns on Example 3 which shows a mode that a fluid is discharged | emitted. 10 is a schematic plan view of a liquid delivery device according to a modification of Example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass substrate 1a, 2a surface 2, 34, 81 board | substrate 3 flow-path surface 3d end part 4a, 6a terminal part 4, 94 working electrode 5 counter electrode 6 hydrophobic region 7, 33 reference electrode 8 introduction port 10 liquid reservoir part (reservoir)
DESCRIPTION OF SYMBOLS 11, 61, 91, 101 Liquid sending apparatus 13 Flow path part 14, 64, 104 Fluid 15 Flow path space 18 Peripheral part 31 Droplet 33a, 33b, 33c Arrow 34a Metal substrate 34b Film layer 62 Mixed electrode 63 Hydrophilic area | region 64a, 64b Flow path 81a Lower surface 81b Upper surface 91a, 91b, 91c Liquid feeding device part 93 Through-hole 93a Side wall 95 Porous substance 102 Reaction compartment

Claims (7)

A first substrate having a hydrophilic channel surface partially formed with a hydrophobic region;
A position facing the flow path surface is made hydrophilic; a second substrate having a working electrode formed at a position facing the hydrophobic region;
A flow path space between the flow path surface and the second substrate by disposing a distance between the flow path surface and the second substrate. A liquid delivery device to be formed,
A fluid is disposed between the first substrate and the second substrate, and the fluid is in contact with the reference electrode and the working electrode. A liquid feeding device characterized by controlling the movement of the fluid in the flow path space by generating a potential difference therebetween. A first substrate having a hydrophilic channel surface partially formed with a hydrophobic region;
A second electrode on which a reference electrode is formed, a position facing the flow path surface is made hydrophilic, and a working electrode is formed at a position facing the hydrophobic region, and the flow path surface A liquid feeding device in which a flow path space is formed between the flow path surface and the second substrate by being disposed at a distance from the second substrate,
A fluid is disposed between the first substrate and the second substrate, and the fluid is in contact with the reference electrode and the working electrode. A liquid feeding device characterized by controlling the movement of the fluid in the flow path space by generating a potential difference therebetween. A first substrate having a hydrophilic channel surface partially formed with a hydrophobic region;
A second electrode on which a reference electrode and a counter electrode are formed, a position facing the channel surface is made hydrophilic, and a working electrode is formed at a position facing the hydrophobic region, and A liquid delivery device in which a flow path space is formed between the flow path surface and the second substrate by disposing the flow path surface and the second substrate with a distance. ,
In a state where a fluid is disposed between the first substrate and the second substrate, and the fluid is in contact with the reference electrode, the counter electrode, and the working electrode, the reference electrode and the action A liquid feeding device that controls the movement of the fluid in the flow path space by generating a potential difference with an electrode.   The liquid feeding device according to claim 1, wherein an insulating layer is provided on the working electrode.   5. The liquid feeding device according to claim 1, wherein a mixing electrode for mixing the fluid moving in the flow path space is provided on the second substrate. 6.   6. The liquid feeding device according to claim 1, wherein the second substrate is provided with a fluid discharge portion for discharging the fluid moving through the flow path space.   The liquid feeding device according to any one of claims 1 to 6, wherein the potential of the working electrode is set within a potential range in which a change in interfacial tension is caused by adsorption of cations in the fluid.