JP5822491B2 - Fluid mixing device - Google Patents

Description

  The present invention relates to a fluid mixing apparatus. More specifically, the present invention relates to a fluid mixing apparatus that mixes a plurality of fluids, for example, a heterogeneous fluid containing a plurality of compounds or particulate materials, a two-phase fluid, a multiphase fluid, and the like by utilizing vortex flow and diffusion.

  A micropump using electroosmosis has advantages such as a relatively simple structure and easy mounting in a microchannel (microchannel). For this purpose, the micropump is used in fields such as μTAS (Micro-Total Analysis System, Lab-on-a-chip, fluid integrated circuit (fluid IC)).

  Under these circumstances, in recent years, a micropump using induced-charge electroosmosis (ICEO) has attracted attention. The reason is attracting attention because of the advantages that the flow rate of the liquid can be increased and the chemical reaction occurring between the electrode and the liquid can be suppressed by AC driving.

  Patent Document 1 discloses a mixer (mixing device) and a pump (liquid feeding device) that use induced charge electroosmosis, a micromixer that uses a vortex generated by an ICEO flow around a cylindrical metal post, and an ICEO flow. A utilized micropump is disclosed.

  On the other hand, Non-Patent Document 1 discloses a micromixer using a screw type (spiral type) vortex passively generated by a V-shaped groove structure provided on a flow path wall.

U.S. Pat. No. 7,081,189

“Science”, 295, 647, (2002)

  However, the mixer using the ICEO of Patent Document 1 needs to stop the flow in order to perform effective mixing. In addition, it may be difficult to continuously perform various processes in a constant flow, which may reduce the processing speed of the entire fluid device such as μTAS.

  Currently, a mixer that requires a large external pressure source is generally used as the mixer. As an alternative mixer, if a large-sized external pressure source or the like is not required, and a mixer with a small and simple structure can be realized, the size and cost of the entire system can be drastically reduced. There is a possibility of widening.

  In addition, if a small and simple mixer capable of continuously realizing effective mixing in a constant flow required by the apparatus can be realized, a fluid integrated circuit that greatly improves the processing speed of the entire fluid apparatus such as μTAS. May be possible.

  On the other hand, Non-Patent Document 1 generates screw-type vortices by the groove structure, but in order to utilize the generation of passive vortices when the fluid flows through the flow path, the flow speed required by the device is It is difficult to produce the desired screw flow rate. In addition, when the molecular diffusion coefficient of the fluid and fine particles to be mixed is low and the number of Piclays (= characteristic speed Ux characteristic distance w / molecular diffusion coefficient D) is low, the flow path length necessary for mixing is set in the fluid IC chip. It becomes difficult to keep it within the required size. Therefore, in the micromixer of Non-Patent Document 1, there is a possibility that the degree of freedom in designing a system such as a fluid integrated circuit may be reduced.

  The present invention has been made in view of such a background art, and is a small-sized fluid mixing device capable of continuously mixing fluids and controlling the length of flow paths necessary for fluid mixing. A device is provided.

The fluid mixing device provided by the present invention includes a flow path for conveying a plurality of fluids, a pair of electrodes provided in the flow path, and an alternating voltage application for applying an alternating voltage to the pair of electrodes. have a means, by applying the voltage to the pair of electrodes, the electric double layer is formed in the vicinity of the electrode, inducing generates a slip rate of the electrode surface to the ion to form the electric double layer charge In the fluid mixing apparatus using electroosmosis, the flow path is formed by being surrounded by a pair of substrates and a pair of spacer members, and the pair of the conductive structures constituting a part of the pair of spacer members. been electrode forming the pair of electrodes is arranged perpendicular or substantially perpendicular to the fluid transport direction opposing direction of the pair of electrodes is the flow path is the fluid being transported, the electrode The electrode surface of the front Is inclined in a range of not less than 60 degrees 20 degrees with respect to the normal to the surface of the substrate, by applying a 100KHz following AC voltage than 30Hz to the pair of electrodes, the axis of the fluid transport direction to the fluid And generating a flow in a direction around the shaft.

  ADVANTAGE OF THE INVENTION According to this invention, the small fluid mixing apparatus which can mix a fluid continuously and can control the length of the flow path required for fluid mixing can be provided.

It is the schematic which shows one embodiment of the fluid mixing apparatus of this invention. It is explanatory drawing which shows the mechanism in which a vortex | eddy_current generate | occur | produces in a fluid by the voltage application to a pair of electrode. It is the schematic which shows the other embodiment of the fluid mixing apparatus of this invention. It is the schematic which shows the other embodiment of the fluid mixing apparatus of this invention. It is the schematic which shows the other embodiment of the fluid mixing apparatus of this invention. It is the schematic which shows the other embodiment of the fluid mixing apparatus of this invention.

  A fluid mixing apparatus according to the present invention includes a flow path for transporting a plurality of fluids, a pair of electrodes provided in the flow path, and a voltage applying unit for applying a voltage to the pair of electrodes. It is a fluid mixing device. The pair of electrodes are arranged such that the facing direction of the pair of electrodes is perpendicular or substantially perpendicular to the fluid conveyance direction in which the fluid is conveyed in the flow path. Then, by applying a voltage to the pair of electrodes, the fluid is caused to flow in a direction around the shaft with the fluid conveyance direction as an axis.

  In the fluid mixing apparatus of the present invention, a voltage sufficient to generate a sufficient vortex flow rate corresponding to the constant speed required by the apparatus is applied to the pair of electrodes. As a result, a vortex flow can be generated in a direction that goes around the axis with the direction in which the fluid is conveyed as an axis, and the fluid can be continuously and effectively mixed in a short time by the vortex and the molecular diffusion effect. In addition, the present invention is a fluid mixing device having a small and simple structure with a high degree of design freedom and capable of controlling the length of a flow path necessary for mixing fluids and keeping the flow path length within a required size. .

  Hereinafter, the fluid mixing apparatus of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view showing an embodiment of the fluid mixing apparatus of the present invention, FIG. 1 (a) is an overall schematic view, and FIG. 1 (b) is a partial schematic view. In FIG. 1A, 1 is a flow path for conveying a plurality of fluids, 2 and 3 are electrodes, a pair of electrodes provided facing the wall surface of the flow path 1 or the flow path, and 4 is an electrode. Voltage application means 5 for applying a voltage to the fluid is a fluid conveyance direction in which the fluid is conveyed in the flow path. Reference numeral 6 denotes an eddy current generated by applying a voltage to the pair of electrodes 2 and 3, and shows a flow generated in a direction around the axis around the fluid conveyance direction 5. 7 and 8 indicate the sliding speed Vs of the electrode surface generated by voltage application. 13 fluids are shown.

  The pair of electrodes 2 and 3 are disposed such that the facing direction 12 of the pair of electrodes is perpendicular or substantially perpendicular to the fluid conveyance direction 5 in which the fluid is conveyed in the flow path. Specifically, in FIG. 1B, the angle θ between the fluid conveyance direction 5 and the facing direction 12 of the pair of electrodes is 45 degrees or more and 135 degrees or less, preferably 80 degrees or more and 100 degrees or less, and more preferably. Is preferably approximately 90 degrees.

  The flow path 1 is formed by being surrounded by a pair of substrates and a pair of spacer members, and a pair of electrodes 2 and 3 are formed from a conductive structure constituting a part of the pair of spacer members. The electrode surface of the electrode is preferably inclined with respect to the normal line of the substrate surface. Specifically, in FIG. 1A, the inclination angle Φ between the electrode surface of the electrode 2 and the normal line of the substrate surface of the substrate 9 is 20 degrees or more and 60 degrees or less, preferably 30 degrees or more and 50 degrees. The following is desirable.

  FIG. 2 is an explanatory diagram showing a mechanism in which a vortex is generated in a fluid by applying a voltage to a pair of electrodes.

  When a voltage is applied to the pair of electrodes 2 and 3, an electric field E is generated in the flow path 1. By this electric field, negative ions 12 gather on the positive electrode 2 side, positive ions 11 gather on the negative electrode 3 side, and a so-called electric double layer is formed in the vicinity of the electrode. The ions forming the electric double layer generate a sliding velocity Vs on the surface by an electric field along the electrode surface. This slip velocity Vs also has a net value with respect to the AC voltage, and this net slip velocity Vs generates a vortex 6 in a direction that goes around the axis around the fluid transport direction 5 in which the fluid is transported. .

  In the fluid mixing device of the present invention, a desired voltage is applied to the pair of electrodes 2 and 3 that are arranged opposite to each other in a direction perpendicular or substantially perpendicular to the fluid conveyance direction 5 in which the fluid is conveyed in the flow path. Apply. By applying the voltage, a vortex 6 having a fluid conveyance direction 5 as an axis in which the fluid is conveyed is generated, and mixing can be effectively and continuously realized in a constant flow of a plurality of fluids. Further, by controlling the voltage applied to the pair of electrodes 2 and 3, the applied frequency, and the like, the length of the flow path required for fluid mixing can be controlled within the required size. Therefore, the present invention can realize a fluid mixing device having a small and simple structure with a high degree of design freedom.

  In the present invention, the flow generated in the direction around the axis about the fluid conveyance direction 5 in which the fluid is conveyed is a single-axis vortex that circulates the entire flow path, and divides the cross section of the flow path. Multiple swirl groups with multiple axes may be used. In particular, to effectively promote mixing, it is desirable to generate vortices that cross the fluid phase flow of interest. In addition, the vortex generated in the direction of circling the axis around the fluid conveyance direction 5 in which the fluid is conveyed is combined with the flow in the direction in which the fluid is conveyed to form a screw-like flow. This includes cases where the flow is extremely slow or where the flow has stopped.

The voltage application means can be freely used such as a battery, an AC power supply, a DC power supply, a pulse voltage source, an arbitrary waveform voltage source, etc. In order to suppress the generation of bubbles due to an electrochemical reaction or the like, an AC voltage of 30 Hz or higher is desirable. It is preferable to use a voltage source. It is desirable to use an alternating voltage of 100 KHz or less in order to charge the electric double layer. The average electric field intensity E ₀ (= V ₀ / d) determined from the applied voltage V ₀ and the distance d between the electrodes is about 10 ⁴ V / m in order to generate an AC electroosmosis (ACEO) flow or an ICEO flow. Is preferably about 0.1 to 100.0 × 10 ⁴ V / m. In particular, the voltage application means comprises an AC voltage source, and by applying a voltage from the AC voltage source to a pair of electrodes, an eddy current due to AC electroosmosis (ACEO) or induced charge electroosmosis (ICEO) is generated in the fluid. It is preferable.

  Thus, the present invention is clearly distinguished from devices that require a passive, general power source. That is, the impedance connected to the pair of electrodes in the present invention does not include the impedance and power supply of a general power supply. The member that functions as a specific impedance will be described in detail in the embodiment, but the point that the voltage due to the thermal noise is increased by configuring the member with a shape or material that is substantially equal to the impedance of the liquid drive element. To preferred.

  As a material constituting the pair of electrodes, a conductive material that induces an electric charge by an electric field is used, and in addition to a metal, carbon, a carbon-based material, or the like can be given. Examples of the metal include gold and platinum. However, this member is also preferably made of gold, platinum, or a carbon material that is stable with respect to the liquid to be conveyed. In addition, it is preferable that a conductive material of a chemically stable material (gold, platinum, carbon, etc.) is brought into contact with the liquid surface, but an insulating film is applied to a metal such as Ta, Ti, Cu, Ag, Cr, Ni, etc. Etc. may be used.

  In addition, the number of the pair of electrodes provided in the flow path can be a plurality of pairs in order to efficiently generate a vortex, and the width of the flow path, the size of the conductive member, and the liquid to be conveyed Can be selected in consideration of the viscosity and the like.

  The electrode may be in the form of a bulk like a spacer, thin film, or linear. The electrode length along the flow path may be long or short, and a plurality of independent pairs of electrodes may be arranged along the flow path.

  The pair of electrodes may have a target structure or an asymmetric structure. In particular, in a pair of thin film electrodes, a pair of electrodes having greatly different electrode areas may be used. Further, there may be a stepped 3D structure on the surface of the thin film electrode. The linear electrodes may be arranged so that a round cross section or a polygon cross section is symmetrical or asymmetric. The pair of spacer-type electrodes may also be disposed symmetrically and asymmetrically on the inclined surface.

  The pair of electrodes is preferably composed of a pair of thin film electrodes disposed on the wall surface of the flow path in a direction parallel or substantially parallel to the fluid transport direction of the fluid. Or it is preferable that a pair of electrode consists of a pair of linear electrode arrange | positioned in the said flow path in the parallel or substantially parallel direction with respect to the fluid conveyance direction of the fluid.

In the present invention, the flow path for conveying the fluid can be made of a material generally used in the field such as μTAS. Specifically, it can be made of a material that is stable with respect to the liquid to be transported. Examples of such a material include inorganic materials such as SiO ₂ and Si, and polymer resins such as fluororesin, polyimide resin, and epoxy resin. Etc.

  The width w of the cross section of the channel is preferably about 10 μm to 1 mm in order to mix the fluid containing bio-related particles, but may be 1 to 2000 μm as necessary.

  The depth h of the flow path is preferably deeper (larger) than the width of the cross section of the flow path from the viewpoint of increasing the flow rate. Specifically, the depth / width of the channel cross-section is 0.1 or more, more preferably 0.2 or more, and still more preferably 0.5 or more.

  In the present invention, the fluid that can be transported in the flow path basically includes polar molecules containing a charged component, and examples thereof include water and solutions containing various electrolytes. In addition, the fluid may be a fluid containing fine bubbles or oil / fat materials contained in an electrolyte solution such as water, or a fluid containing inorganic and organic fine particles or colloidal particles.

  Moreover, in order to produce the apparatus of the present invention, a MEMS technique, a lithography technique, or the like that generally creates a fluid conveyance device using a so-called micro-channel such as a micro TAS can be used. Moreover, you may create by the bonding technique, press work, etc. which include machining.

  Hereinafter, the present invention will be described in detail with specific examples. In the following description with reference to the drawings, in principle, the same members in the drawings are denoted by the same reference numerals, and redundant description will be omitted.

Example 1
Example 1 will be described based on the fluid mixing apparatus shown in FIGS. 1 and 2.

  In FIG. 1, 1 is a flow path for transporting a plurality of fluids, 2 and 3 are a pair of electrodes located adjacent to the flow path, 4 is a voltage applying means for applying the voltage of the electrodes, and 5 is a flow path. This is the direction in which the fluid is conveyed in the path. Reference numeral 6 denotes an eddy current generated by applying a voltage to the pair of electrodes 2 and 3, and shows a flow generated in a direction around the axis with the fluid conveyance direction 5 in which the fluid is conveyed. Further, the pair of electrodes 2 and 3 are arranged to face each other in a direction perpendicular or substantially perpendicular to the fluid conveyance direction 5 in which the fluid is conveyed in the flow path. Moreover, 7 and 8 show the sliding speed Vs of the electrode surface generated by voltage application.

  In Example 1, the flow path 1 is composed of a pair of substrates 9 and 10 and a pair of spacer members, and the pair of electrodes 2 and 3 is a conductive structure constituting a part of the spacer member, and the electrode surface is It has a structure tilted from a direction perpendicular to the substrates 9 and 10.

  FIG. 2 shows the accumulation of the positive ions 11 near the negative electrode, the accumulation of the negative ions 12 on the positive ion electrode, and the electric field E when the left electrode 2 has a positive potential and the right electrode 3 has a negative potential. The generation of the slip velocity Vs due to the component along the electrode surface of FIG. Similarly, even if the voltages are switched, a sliding speed in the same direction is generated, so that an eddy current similar to DC can be generated for AC. However, the use of AC voltage has the effect of suppressing the generation of bubbles derived from electrochemical reactions, and it is preferable to use AC. In addition, the flow resulting from the movement of ions in the electric double layer formed to shield the induced charge generated on the electrode surface is known as induced charge electroosmosis (ICEO) or AC electroosmosis (ACEO). Yes. Example 1 is a fluid mixing device in which the voltage applying means is an AC voltage source and generates eddy currents by AC electroosmosis (ACEO) or induced charge electroosmosis (ICEO), and is effective in suppressing the generation of bubbles and the like. is there. Further, the direction of the vortex may be opposite due to the influence of the surface condition, ion response delay, Faraday current, and the like.

Now, in the case of simple mixing of a two-phase flow (for example, a two-phase flow in which the upper half is fluid A and the lower half is fluid B) having a flow path width w, a fluid flow velocity U, and a molecular diffusion coefficient D, mixing is performed. The required time (= mixing time t _m ) is t _{m to} w ² / D. Further, the distance necessary for mixing (= mixing distance dy _m ) is dy _{m to} U (w ² / D) = wPe, and the mixing distance is proportional to the number of Peckles Pe (= Uw / D).

On the other hand, in the case of a mixer using vortex flow, the substantial distance Δr to be diffused required to mix the fluid in the flow path length Δy decreases exponentially from the value of w, and λ is vortexed. Δr = weexp (−Δy / λ). Further, the flow time τr in the flow path when traveling Δy is τ _r = Δy / U, and the diffusion time τ _D required to diffuse Δr is τ _D = Δr ² / D = (w ² / D ) Exp (-2Δy / λ). Thus, by imposing the .tau.r = tau _D becomes conditions, mixing length [Delta] y _m is, Δy _m ~0.5λln for large Pe (Pe) [~λlog (Pe )] , and the mixing time tm is tm = Derutaym / U = (λ / U) ln (Pe). However, in this specification, ~ indicates order evaluation approximation. In other words, the evaluation is based on the digit (order), and if the digit is the same, it indicates that the order is the same even if the detailed numerical value is not the same.

  That is, the present invention, which uses an ICEO or ACEO flow or the like to generate a vortex flow around the direction of fluid conveyance and generate a screw type (spiral type) flow, allows fluid to flow more than a simple diffusion mixer when Pe is large. There is an effect that can be mixed at a short mixing distance. Also, there is an effect that the mixing time can be made shorter than that of the simple diffusion mixer.

Meanwhile, as disclosed in Non-Patent Document 1, even in a passive screw (helical) mixer to form a V-shaped groove in the bottom surface of the channel, mixing length [Delta] y _m is [Delta] y _m ~ for large Pe λlog (Pe), which is effective in mixing the fluid at a shorter mixing distance than the simple diffusion mixer.

  However, the active screw (helical) mixer of the present invention has an excellent design flexibility that is not found in the passive screw (helical) mixer. In particular, in the active type screw mixer, when the representative velocity of the vortex is Uv and α is a proportional constant, if λ to αw (U / Uv), then λ → 0 and Δr → w at the limit of Uv → 0. It is reasonable because it matches a simple mixer. On the other hand, in a passive screw mixer using a groove, λ is determined when the groove structure is determined, and λ is dynamically adjusted in accordance with a large variation state of Pe and design requirements, so that the mixing distance is designed (for example, 1 cm). There is a problem that cannot be suppressed. Further, in a passive screw mixer using a groove, even if the groove structure is adjusted, it is difficult to extremely improve U / Uv. At present, α to 25, U / Uv to 1, that is, λ A range of ~ w (U / Uv) ~ 25w is considered the best design.

  In the active type screw (helical) mixer using the ICEO etc. of the present invention, the U / Uv ratio is dynamically adjusted according to the large fluctuation situation of Pe and the design requirement, and the mixing distance is designed by changing the λ. For example, there is an effect that can be suppressed within 1 cm).

^{Specifically,} w~100μm, U~1mm / ^s, when the ^D~10 -12 ^m 2 / s, the Pe~10 ^5. At this time, in the case of a passive screw (spiral) mixer, the mixing distance is Δy _{m to} λlog (Pe) to 25 w · log (Pe) = 125 w = 1.25 cm, and the mixing distance is kept within the design specification (1 cm). I can't.

On the other hand, in the active type screw (helical) mixer using the ICEO or the like of the present invention, U / Uv to 0.5, that is, Uv = 2 mm / s is adjusted to λ = 12.5 w. As a result, the mixing distance can be Δy _{m to} λlog (Pe) to 12.5 w · log (Pe) = 62.5 w to 0.6 cm, and the mixing distance can be suppressed within the design specification (1 cm). is there.

1 and 2, when the average width of the flow path is w, the height of the flow path is h, and the inclination angle of the electrodes 2 and 3 with respect to the normal to the substrate surface is Φ, the typical velocity of the vortex is Uv to βε. (HsinΦ) E ₀ ² / μ. Where ε is the dielectric constant of the fluid (for example, in the case of water, ε to 80ε ₀ ; ε ₀ is the vacuum dielectric constant), μ is the viscosity of the fluid, E ₀ = V ₀ / w is the average applied electric field, V ₀ is an applied voltage to the electrodes 2 and 3 (effective voltage in the case of AC). Β is a parameter that varies depending on the electrode interface, the applied voltage, the representative size of the system, etc., and has a size of about 0.001 to 1. Also, the direction of rotation of the vortex often shows the opposite direction to the standard theory.

Now, w = 100 μm, h = 100 μm, Φ = 30 °, ε-80ε ₀ , β-0.1, μ = 1 mPa · s, c-hsinΦ-50 μm. At this time, when a voltage of V ₀ = 1.0, 1.5, 2.0, and 3.0 V is applied, an electric field of E ₀ = 10, 15, 20, 30 kV / m, and Uv˜0.35, 0 A typical eddy current velocity of 80, 1.4, 3.2 mm / s is obtained.

^{Therefore, α~25, w~100μm, U~1mm / s} , when the ^D~10 -12 ^m 2 / s, i.e., when the Pe～10 ^5, a fluid mixing system of the present _{invention, V} 0 = 1 When voltages of 0.0, 1.5, 2.0, and 3.0 V are applied, U / Uv to 2.86, 1.25, 0.71, and 0.31, so Δym [˜1.25 cmx (U / Uv)] is 3.58, 1.56, 0.89, and 0.39. Therefore, if a voltage of 2 V or more is applied, there is an effect that the mixing distance can be suppressed within the design specification (1 cm).

  In addition, when mixing biosamples, mixing at a flow rate higher than necessary may damage the biosample, and various types of biosamples should be dynamically adjusted to the optimal vortex flow rate and processed using a passive mixer. It is difficult. In the present invention, the optimum vortex flow velocity can be set as appropriate according to the number of Piclays, and there is an effect of avoiding damage to the biosample.

  Further, if the tilt angle Φ of the electrode surface is too small, a sufficient speed cannot be obtained, and if it is too large, the flow path becomes flat and is strongly affected by the viscosity, and is preferably about 20 to 60 degrees.

(Example 2)
FIG. 3 is a schematic diagram showing the characteristics of the fluid mixing apparatus of the present embodiment.

  The fluid mixing apparatus of the present embodiment is different from the apparatus of Embodiment 1 in that the shape of the pair of electrodes and the number and distribution of vortexes formed are different.

FIG. 3A has non-parallel electrode surfaces facing the flow path, and the cross section of the flow path formed by the pair of electrodes and the upper and lower substrates is a (conformal) trapezoid. By applying an AC or DC voltage to the pair of electrodes 2 and 3, two vortex flows 6 can be generated, and the same effect as in the first embodiment can be obtained.
FIG. 3B is an example in which the left and right of the pair of electrode surfaces have an asymmetric inclination angle Φ, and the cross section of the flow path is a trapezoid (non-conformal). By applying an AC or DC voltage to the pair of electrodes, one eddy current can be generated, and the same effect as in the first embodiment can be obtained.
FIG. 3C shows an example in which the channel surface has a concave electrode surface on the left and right, and four eddy currents can be generated by applying an AC or DC voltage to a pair of electrodes. Effects can be obtained.
FIG. 3 (d) shows an example in which the channel surface has a convex electrode surface on the left and right, and four vortex flows can be generated by applying an AC or DC voltage to a pair of electrodes. Similar effects can be obtained.

(Example 3)
FIG. 4 is a schematic diagram showing the fluid mixing apparatus of the present embodiment.

  The apparatus of the present embodiment is different from the apparatus of the first embodiment in that the pair of electrodes is a pair of thin film electrodes 42 and 43 arranged in parallel with a gap on the wall surface of the flow path.

  In FIG. 4, reference numerals 44 and 45 denote insulating channel walls, and by applying an AC voltage to the thin film electrodes 42 and 43, eddy currents 46 and 47 having axes in the fluid transport direction of the channel are generated. The same effect as 1 can be obtained.

Example 4
FIG. 5 is a schematic diagram showing the fluid mixing apparatus of the present embodiment.

  The apparatus of the present embodiment is different from the apparatus of the first embodiment in that the pair of electrodes has an asymmetric electrode area.

In FIG. 5A, by applying an AC voltage to the asymmetric electrodes 52 and 53, a vortex 56 having an axis in the fluid conveyance direction of the flow path is generated, and the same effect as in the first embodiment is obtained.
FIG. 5B shows an example in which there are a plurality of asymmetrical pairs of electrodes, and the same effect as in the first embodiment can be obtained by applying an AC voltage.
FIG. 5C shows an example in which there are a plurality of asymmetrical pairs of electrodes above and below, and the same effect as in the first embodiment can be obtained by applying an AC voltage.
FIG. 5D shows an example in which there are a pair of asymmetric electrodes on the left and right flow path walls extending vertically, and the same effect as in the first embodiment can be obtained by applying an AC voltage.

(Example 5)
FIG. 6 is a schematic diagram showing the fluid mixing apparatus of the present embodiment.

  The fluid mixing apparatus according to the present embodiment is different from the apparatus according to the first embodiment in that the pair of electrodes are linear electrodes 62 and 63 arranged in parallel in the flow path 1. The diameter of the linear electrode is preferably 1 μm to 1 mm.

  In FIG. 6, by applying an AC voltage to the linear electrodes 62 and 63, a vortex 66 having an axis in the fluid conveyance direction of the flow path is generated, and the same effect as in the first embodiment is obtained.

  Since the fluid mixing apparatus of the present invention can continuously mix the fluids and control the length of the flow path necessary for mixing as required, the μTAS, the fluid integrated circuit, the lob-on- It can be used in fields such as a-chip.

1 Flow path 2, 3 Electrode 4 Voltage application means 5 Fluid transport direction 6 Eddy current 7, 8 Slip velocity Vs
9, 10 Substrate 12 Opposing direction of a pair of electrodes 13 Fluid

Claims (1)

A flow path for conveying a plurality of fluids, and a pair of electrodes provided in the flow path, have a an AC voltage application means for applying an AC voltage to the pair of electrodes, said pair of electrodes A fluid mixing device using induced electric charge electroosmosis in which an electric double layer is formed in the vicinity of the electrode by applying the voltage and a slip velocity of the electrode surface is generated in ions forming the electric double layer. The flow path is formed by being surrounded by a pair of substrates and a pair of spacer members, and the pair of electrodes is formed from a conductive structure constituting a part of the pair of spacer members. , The opposing direction of the pair of electrodes is arranged to be perpendicular or substantially perpendicular to the fluid conveyance direction in which the fluid is conveyed in the flow path, and the electrode surface of the electrode is a normal to the surface of the substrate 20 degrees or more against Degrees is inclined in the following ranges, by applying a 100KHz following AC voltage than 30Hz to the pair of electrodes, thereby generating the direction of flow orbiting the shaft the fluid transport direction as an axis to the fluid A fluid mixing device.

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