JP2010088977A - Sonic wave generation element, vessel and stirring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sonic wave generation element, a vessel and a stirring device capable of varying even a single sound flow generated in liquid into multiple modes. <P>SOLUTION: There are provided with the sonic wave generation element 14 having a piezoelectric substrate 14a and sound generation parts 14b, 14c disposed on the piezoelectric substrate; the vessel; and stirring device. In the sonic wave generation element 14, a plurality of sound generation parts are electrically connected in parallel, and the central frequencies of respective basic waves differ, and a part of resonant frequency zones overlap. At least one inflow port receiving liquid at one end of a micro flow path and an outflow port at the other end of the branched micro flow path branched from the micro flow path are formed on the vessel, and the vessel is provided with the sonic wave generation element near the branched part of the micro flow path and branched micro flow path. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sound wave generating element, a container, and a stirring device.

  2. Description of the Related Art Conventionally, a liquid mixing apparatus that mixes a liquid flowing in a micro flow channel using sound waves generated by sound wave generation means is known (see, for example, Patent Document 1). In this liquid mixing apparatus, the sound axis of the sound wave generated by the sound wave generating means is displaced from the center of the microchannel, and the liquid is mixed by the acoustic flow generated by the sound wave leaking into the liquid.

JP-A-2005-254112

  By the way, in order to properly mix the liquid flowing through the microchannel, it is necessary to change the acoustic flow generated in the liquid into a plurality of modes. Therefore, the liquid mixing apparatus must be provided with a plurality of sound wave generating means. There was a problem.

  The present invention has been made in view of the above, and an object of the present invention is to provide a sound wave generating element and a container capable of changing an acoustic flow generated in a liquid into a plurality of modes even when used alone. .

  In order to solve the above-described problems and achieve the object, a sound wave generating element of the present invention is a sound wave generating element having a piezoelectric substrate and a sound generating unit disposed on the piezoelectric substrate, and the plurality of sound generating elements. The parts are electrically connected in parallel, the center frequencies of the respective fundamental waves are different, and a part of the resonance frequency band overlaps.

  The sound wave generating element according to the present invention is characterized in that, in the above-mentioned invention, the ratio of the vibration response intensity to the electrical input signal of each sounding portion of the plurality of sounding portions changes according to the driving frequency. .

  The sound wave generating element of the present invention is characterized in that, in the above invention, the plurality of sound generating units switch sound generating units that generate sound waves according to the driving frequency.

  The sound wave generating element of the present invention is characterized in that, in the above invention, the driving frequency input to the sound wave generating element is changed based on information on a liquid analysis item, a property of the liquid, or a liquid amount. And

  In order to solve the above-described problems and achieve the object, the container of the present invention includes at least one inlet for allowing liquid to flow into one end of the microchannel, and a branched microchannel branched from the microchannel. A container having an outlet at the other end of the microchannel, wherein the sound wave generating element is provided in the vicinity of the branch portion of the microchannel and the branch microchannel.

  Further, in the container of the present invention, in the above invention, the starting point of the acoustic flow generated in the microchannel due to the sound wave generated from the one sounding part of the sound wave generating element having a plurality of sounding parts is near the inner wall of the container. The plurality of sound generating portions are formed such that the starting points of the acoustic flow by the adjacent sound generating portions are alternately positioned.

  In order to solve the above-described problems and achieve the object, the stirring device of the present invention includes at least one inflow port for allowing liquid to flow into one end of the microchannel and a branched microchannel branched from the microchannel. Of the container having an outlet formed at the other end thereof, the sound wave generating element provided in contact with the vicinity of the branch portion of the micro flow channel and the branch micro flow channel, and a drive unit for driving the sound wave generating device It is characterized by having.

  The stirring device according to the present invention is the above-described invention, wherein the starting point of the acoustic flow generated in the micro-channel due to the sound wave generated from the one sounding part of the sound wave generating element having a plurality of sounding parts is the inner wall of the container. It exists in two places apart in the vicinity, and the plurality of sound generation parts are formed such that the starting points of the acoustic flow by adjacent sound generation parts are alternately located.

  In the sound wave generating element of the present invention, the plurality of sound generating parts have different center frequencies, and a part of the resonance frequency band is overlapped. A sound wave generating element is provided in the vicinity. For this reason, according to the present invention, it is possible to provide a container including a sound wave generating element and a micro flow channel that can change an acoustic flow generated in a liquid into a plurality of modes even when used alone. Play.

(Embodiment 1)
Hereinafter, a first embodiment of a sound wave generating element, a container, and a stirring device according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing a container according to Embodiment 1 together with a stirring device. FIG. 2 is a plan view of the container shown in FIG. FIG. 3 is an enlarged cross-sectional view of part A of FIG.

  As shown in FIG. 1, the container 1 is formed with a microchannel 4 and a branched microchannel 5 branched from the center of the microchannel 4 by a substrate 2 and a cover 3. A surface acoustic wave element 14 which is a single sound wave generating element is in contact. The container 1 constitutes a so-called microchannel device used for mixing liquid chemicals or a liquid sample containing a reagent and a specimen together with the stirring device 10.

  As shown in FIGS. 1 and 2, the micro flow path 4 and the branched micro flow path 5 have openings 4 a and 4 b serving as inflow ports and openings 5 a serving as outflow ports on the side surfaces of the container 1, respectively. As shown in FIG. 3, the branch microchannel 5 is supplied from the openings 4a and 4b and mixes different liquids flowing in a laminar flow in the microchannel 4 by molecular diffusion. However, the stirring performance of the container 1 is improved by the stirring device 10.

  Here, the surface acoustic wave element 14 is in contact with the bottom surface of the substrate 2 in the vicinity of the branching portion where the branched microchannel 5 branches from the microchannel 4 via an acoustic matching layer such as liquid or gel. However, in FIG. 3, in order to clearly show the arrangement of the surface acoustic wave element 14, the state viewed from above the container 1 is drawn with a solid line. In addition, the drawings showing the microchannels used in the following description including the microchannels 4 and the branch microchannels 5 mainly show the arrangement of the microchannels. It is not drawn accurately including the relative width between the roads.

  As shown in FIG. 1, the stirring device 10 includes a drive unit 11 and a surface acoustic wave element 14.

  The driving unit 11 drives the surface acoustic wave element 14 to forcibly stir different liquids flowing in the laminar flow in the branch microchannel 5, and includes a signal generator 12 and a drive control circuit 13. Yes. At this time, the drive unit 11 controls the frequency of the drive signal within a common resonance frequency band so that the plurality of sound generation units 14b and 14c simultaneously generate sound waves having different frequencies.

  The signal generator 12 has an oscillation circuit that can change the oscillation frequency based on a control signal input from the drive control circuit 13, and generates a high-frequency drive signal of about several MHz to several hundreds of MHz as a surface acoustic wave element. 14

  The drive control circuit 13 uses an electronic control means (ECU) with a built-in memory and timer, and controls the operation of the signal generator 12, so that the drive signal output from the signal generator 12 to the surface acoustic wave element 14 is output. Control voltage and current. The drive control circuit 13 controls the operation of the signal generator 12, for example, characteristics of sound waves (frequency, intensity, phase, wave characteristics) emitted by the surface acoustic wave element 14, waveforms (sine waves, triangular waves, rectangular shapes). Wave, burst wave, etc.) or modulation (amplitude modulation, frequency modulation) or the like. Further, the drive control circuit 13 can change the frequency of the high frequency signal oscillated by the signal generator 12 according to a built-in timer.

  The surface acoustic wave element 14 is a single sound wave generating element, and as shown in FIG. 4, sound generating portions 14b and 14c composed of comb-shaped electrodes (IDT) 140b and 140c are formed at intervals on the surface of the piezoelectric substrate 14a. A pair of input terminals 14e are connected in parallel by a bus bar 14f. The surface acoustic wave element 14 is in contact with the surface acoustic wave element 14 through an acoustic matching layer such as liquid or gel. The sound generation units 14b and 14c are sound generation units that convert the drive signal input from the drive control unit 11 into surface acoustic waves (sound waves). The surface acoustic wave element 14 is connected between the input terminal 14 e and the drive control unit 11.

  At this time, the sound generation units 14b and 14c have overlapping resonance frequency bands. That is, as shown in FIG. 5, the sound generation units 14b and 14c have a center frequency of the fundamental wave of the sound generation unit 14b as fc1 and a center frequency of the fundamental wave of the sound generation unit 14c as fc2 (fc1 <fc2) (MHz). The half-value widths Δfc1 and Δfc2, which are response intensity values of −3 dB of the vibration response intensity with respect to the electrical input signal at the respective center frequencies, are defined as resonance frequency bands, and some of the resonance frequency bands overlap. The sound generation units 14b and 14c individually have frequency characteristics indicated by dotted lines in FIG. 6 with respect to the input reflection coefficient (dB), and the solid line indicates the frequency characteristics obtained by combining the two. Furthermore, the sound generating portions 14b and 14c are formed so that the starting points of the acoustic flow are alternately located. This will be described later.

  Here, as the piezoelectric substrate 14a, for example, a Y-cut Z-propagation (YZ) lithium niobate (LiNbO3) crystal can be used. The sound generating portions 14b and 14c are formed on the piezoelectric substrate 14a by the photolithography technique together with the input terminals 14e and the bus bar 14f. Note that the drawings showing the surface acoustic wave elements used in the following description including the surface acoustic wave element 14 shown in FIG. 4 are mainly intended to show the outline of the configuration. The line width, pitch, or position on the piezoelectric substrate 14a of the mold electrode is not necessarily drawn accurately.

  In the container 1 configured as described above, when different liquids are supplied into the microchannel 4 from the openings 4a and 4b, the container 1 flows in a laminar flow in the branch microchannel 5 while maintaining an interface with the different liquids. The different liquids flow out from the opening 5a while being mixed by molecular diffusion inside.

  At this time, when the drive unit 11 inputs a drive signal to the surface acoustic wave element 14 through the input terminal 14e, the surface acoustic wave element 14 is generated by the sound generation unit 14b or the sound generation unit 14c according to the frequency of the input drive signal. Driven to induce surface acoustic waves (bulk waves). The induced surface acoustic wave (bulk wave) propagates from the acoustic matching layer into the substrate 2 and leaks as a longitudinal wave into a liquid sample having a close acoustic impedance. As a result, the container 1 generates two acoustic flows in the branched microchannel 5 from the position corresponding to the sounding portion 14b or the sounding portion 14c in the liquid sample to the upper left and the upper right (see FIG. 9). The effect of molecular diffusion is promoted.

  Here, the surface acoustic wave element 14 is designed so that the electric impedance at the center frequency of each of the sound generating portions 14b and 14c is 50Ω, which is the same as that of the external electric system. At this time, the surface acoustic wave element 14 is shown in FIG. 7 as an equivalent circuit when the electrical impedances of the sound generating portions 14b and 14c are Z1 and Z2, respectively. Therefore, for example, when the drive unit 11 inputs a drive signal having the frequency fc1 to the surface acoustic wave element 14, as shown in FIG. 8, the sound generation unit 14b has an electrical impedance of Z1 = 50Ω, and the sound generation unit 14c has an electric impedance of Z2. = 500Ω. Therefore, in the surface acoustic wave element 14, the sound generating portion 14b is strongly excited, whereas the sound generating portion 14c is weakly excited.

  Here, as shown in FIG. 9, sound waves generated by the excitation of the sound generation units 14 b and 14 c propagate through the piezoelectric substrate 14 a and the substrate 2, respectively, and solid-liquid with the liquid sample Ls in the branch microchannel 5. It is mode-converted into a longitudinal wave at the interface and emitted into the liquid sample Ls. As this radiated longitudinal wave propagates through the liquid sample, an acoustic flow is generated. At this time, the sound generation units 14b and 14c are formed so that the starting points of the acoustic flow are alternately positioned, and the sound flow caused by the sound wave W1 generated by the excitation of the sound generation unit 14b is set as S11. Let S12 be the acoustic flow resulting from the sound wave W2 generated by excitation.

  Then, as shown in the figure, the acoustic flow S11 generated obliquely upward to the left in the liquid sample Ls in the acoustic flow S11 caused by the sound wave W1 generated by the sound generation unit 14b is caused by the sound wave W2 generated by the sound generation unit 14c. The liquid sample Ls is generated at a position sandwiched between two acoustic streams S12 generated diagonally upward to the right and diagonally upward to the left. For this reason, the two acoustic streams S12 are integrated with the acoustic stream S11 generated obliquely upward to the left, resulting in an acoustic stream S1 having a large cross-sectional area and a high flow velocity. On the other hand, the acoustic flow S11 generated obliquely upward to the right in the liquid sample Ls due to the sound wave W1 generated by the sound generating portion 14b is a single flow, and has a smaller cross-sectional area and a slower flow velocity than the acoustic flow S1. It is. For this reason, when the surface acoustic wave element 14 is driven at the drive frequency F = fc1, when viewed macroscopically, the liquid sample Ls in the branch microchannel 5 has an asymmetric acoustic flow S1 and acoustic flow S2 (= S11) occurs.

  On the other hand, for example, when the drive unit 11 inputs a drive signal having a frequency fc2 to the surface acoustic wave element 14, as shown in FIG. 10, the sound generation unit 14b has an electrical impedance of Z1 = 200Ω, and the sound generation unit 14c has an electrical impedance of Z2 = It is almost opposite to 50Ω. For this reason, in the surface acoustic wave element 14, contrary to the above, the sounding part 14 c is strongly excited while the sounding part 14 b is weakly excited.

  Accordingly, since the sound generating portions 14b and 14c are formed so that the starting points of the acoustic flow are alternately positioned, as shown in FIG. 11, the liquid in the acoustic flow S22 caused by the sound wave W2 generated by the sound generating portion 14c. The acoustic stream S22 generated obliquely upward to the right in the sample Ls is located between two acoustic streams S21 generated obliquely upward and to the left in the liquid sample Ls due to the sound wave W1 generated by the sound generation part 14b. Occurs. For this reason, the two acoustic streams S21 are integrated with the acoustic stream S22 generated obliquely upward to the right, resulting in an acoustic stream S3 having a large cross-sectional area and a high flow velocity. On the other hand, the acoustic flow S22 generated obliquely upward to the left in the liquid sample Ls due to the sound wave W2 generated by the sound generating portion 14c is a single flow, and has a smaller cross-sectional area and a slower flow velocity than the acoustic flow S3. It is. Therefore, when the surface acoustic wave element 14 is driven at the drive frequency F = fc2, when viewed macroscopically, the liquid sample Ls in the branch microchannel 5 has an asymmetric acoustic flow S3 and acoustic flow S4 (= S22) occurs.

  Here, with respect to the center frequencies fc1 and fc2 and the input reflection coefficient (dB), the automatic analyzer uses the stirrer 10 using the surface acoustic wave element 14 having the sound generation portions 14b and 14c having the frequency characteristics shown in FIG. The ion exchange water in the reaction vessel to be used was stirred. At this time, the flow velocity distribution of the acoustic flow generated when the surface acoustic wave element 14 is driven at the drive frequency F = fc1, and the flow velocity of the acoustic flow generated when the surface acoustic wave element 14 is driven at the drive frequency F = fc2. Each distribution is shown in FIG.

  FIG. 13 shows the acoustic flow in the ion-exchanged water contained in the reaction vessel when the surface acoustic wave element 14 is driven at the center frequency fc1 (= 78.3 MHz) and the center frequency fc2 (= 79.2 MHz), respectively. It is the figure which visualized flow velocity (mm / s) distribution with PIV, the vertical axis and the horizontal axis are the side walls on the basis of the intersection line of the side wall inner surface and bottom wall upper surface of the reaction vessel to which the surface acoustic wave element 14 is attached. The distance in the upward direction (mm) along the vertical direction and the distance in the vertical direction of the sidewall (mm) are shown.

  In the figure, θ represents an angle formed by the acoustic flow with respect to the vertical surface of the side wall. PIV is an image processing velocity measurement method (Particle Image Velocimetry). Usually, a marker such as a tracer is added to an invisible flow to make it visible, and image processing and image analysis are performed. It is a method to obtain instantaneous and multi-point velocity information of the flow field by adding technology.

  On the other hand, when the surface acoustic wave element 14 is driven at a driving frequency F = f1 (<fc1) lower than the center frequency fc1 of the sounding part 14b, the sounding part 14b has an electrical impedance of Z1 = 200Ω, and the sounding part 14c has an electrical impedance of Z2. = ∞. For this reason, the surface acoustic wave element 14 is weakly excited only in the sounding portion 14b. For this reason, when the surface acoustic wave element 14 is driven at the drive frequency F = f1, when viewed macroscopically, the liquid sample Ls in the branch microchannel 5 is symmetrical with a minimum cross-sectional area and a low flow velocity. Acoustic flows S5 and S6 are generated.

  When the surface acoustic wave element 14 is driven at a driving frequency F = f2 (fc1 <f2 <fc2) intermediate between the center frequency fc1 of the sound generation unit 14b and the center frequency fc2 of the sound generation unit 14c, the sound generation unit 14b and the sound generation unit 14c The electrical impedance is Z1, Z2 = 100Ω. For this reason, the surface acoustic wave element 14 is excited to approximately the same degree by the sound generating portion 14b and the sound generating portion 14c with an electrical impedance between 50Ω and 200Ω. For this reason, when the surface acoustic wave element 14 is driven at the drive frequency F = f 2, when viewed macroscopically, in the liquid sample Ls in the branched microchannel 5, the acoustic flows S 7 and S 8 have substantially the same flow velocity. A symmetrical acoustic flow S7, S8 with a slightly larger cross-sectional area is produced.

  On the other hand, when the surface acoustic wave element 14 is driven at a drive frequency F = f3 (> fc2) higher than the center frequency fc2 of the sounding part 14c, the sounding part 14b has an electrical impedance of Z1 = ∞ and the sounding part 14c has an electrical impedance of Z2. = 200Ω. For this reason, the surface acoustic wave element 14 is weakly excited only in the sounding portion 14c. For this reason, when the surface acoustic wave element 14 is driven at the drive frequency F = f3, when viewed macroscopically, the liquid sample Ls in the branch microchannel 5 is symmetrical with a minimum cross-sectional area and a low flow velocity. Acoustic flows S9 and S10 are generated.

  Accordingly, the acoustic flow generated in the liquid sample Ls in the branch microchannel 5 is shown in FIG. 14 for each of the drive frequencies F = f1, fc1, f2, fc2, and f3. When the electrical impedance of the external electrical system is another value, for example, 70Ω, it may be designed so that the electrical impedance at the center frequency of the sound generating portions 14b and 14c is 70Ω.

  Therefore, the stirrer 10 creates in advance a drive frequency at which stirring is best while measuring the stirring state of the liquid sample due to the difference in driving frequency as a combination table with the liquid sample, and stores it in the drive control circuit 13. Then, the stirring device 10 automatically selects the drive frequency based on the liquid sample supplied to the container 1 and outputs it to the drive control circuit 13. Thereby, the stirring apparatus 10 can drive the surface acoustic wave element 14 at a frequency optimal for the liquid sample to be supplied.

  For this reason, the stirring device 10 switches the drive frequency of the drive signal for driving the surface acoustic wave element 14 with the drive unit 11, for example, the drive signal having the frequency fc1 that is the center frequency of the sound generation unit 14 b is applied to the surface acoustic wave element 14. input. Then, as shown in FIG. 15, the container 1 is directed toward the opening 4a by the acoustic flow S1 having a large cross-sectional area and a high flow velocity in the branch microchannel 5 and the acoustic flow S2 having a small cross-sectional area and a low flow velocity. Backflow occurs. As a result, the container 1 generates an asymmetric flow field in the branching microchannel 5 and the interface collapses. Therefore, the stirring effect increases toward the opening 5a, and the length of the branching microchannel 5 required for molecular diffusion is increased. Can be shortened.

  On the other hand, for example, when a drive signal having a frequency fc2, which is the center frequency of the sound generation unit 14c, is input to the surface acoustic wave element 14, the container 1 has a large cross-sectional area in the branch microchannel 5 as shown in FIG. A backflow toward the opening 4b is generated by the acoustic flow S3 having a high flow velocity and the acoustic flow S4 having a small cross-sectional area and a low flow velocity. As a result, the container 1 generates an asymmetric flow field in the branching microchannel 5 and the interface collapses. Therefore, the stirring effect increases toward the opening 5a, and the length of the branching microchannel 5 required for molecular diffusion is increased. Can be shortened.

  Thus, even if the surface acoustic wave element 14 is used alone, the acoustic flow generated in the liquid can be changed into a plurality of modes. For this reason, the container 1 controls the driving frequency F within the frequency band (f1 to f3) by the driving unit 11 so that the plurality of sound generating units 14b and 14c simultaneously generate sound waves having different frequencies, or in time division. By switching the driving frequency F between the frequency fc1 and the frequency fc2, it is possible to always drive one or more sounding portions and stir the liquid sample Ls in the branch microchannel 5 by the acoustic flow and the molecular diffusion. The stirring efficiency is improved, and the time required for stirring can be shortened.

  Here, as shown in FIG. 17, the surface acoustic wave element 14 may be in contact with the bottom surface of the substrate 2 such that the sound generating portions 14 b and 14 c are positioned along the branch microchannel 5 at the center of the channel. Further, the surface acoustic wave element 14 may exchange the positions of the sound generation unit 14b and the sound generation unit 14c. When arranged in this manner, the surface acoustic wave element 14 can generate an acoustic flow having a distribution different from the acoustic flow shown in FIG.

  In addition, the container 1 used the openings 4a and 4b of the microchannel 4 as inflow ports and the opening 5a of the branching microchannel 5 as outflow ports. However, in the container 1, the use of the openings 4a and 4b and the opening 5a is arbitrary depending on the state of the acoustic flow generated by the surface acoustic wave element 14 in the liquid sample. For example, the container 1 branches from the opening 4a of the microchannel 4 The opening 5a of the microchannel 5 may be used as an inlet, and the opening 4b of the microchannel 4 may be used as an outlet.

  Further, the container 1 may be configured by attaching the surface acoustic wave element 14 to the bottom surface of the container 1 via an acoustic matching layer such as an epoxy resin. In this case, the surface acoustic wave element 14 is detachably connected between the input terminal 14e and the drive control unit 11, and a drive signal is input. Even if the container 1 is configured in this way, the same effect can be obtained.

(Embodiment 2)
Next, a second embodiment of the container having the microchannel according to the present invention will be described in detail with reference to the drawings. The container in the first embodiment stirs the liquid sample flowing in from the two openings and outflows from the one opening, whereas the container in the second embodiment stirs the liquid sample flowing in from the two openings. Depending on the concentration, it is allowed to flow out from the three openings.

  FIG. 18 is a perspective view showing a container according to Embodiment 2 together with a stirring device. FIG. 19 is a plan view of the container shown in FIG. 20 is an enlarged cross-sectional view of a portion B in FIG. In addition, since the container provided with the micro flow path of Embodiment 2 uses the stirring apparatus of Embodiment 1, the same code | symbol is used about the stirring apparatus.

  In the container 20, as shown in FIG. 18, a microchannel 23 and branch microchannels 24, 25, and 26 are formed by a substrate 21 and a cover 22. In the container 20, the surface acoustic wave element 14 of the stirring device 10 is attached to the side surface of the substrate 21 and the cover 22 in the vicinity of the branching portion where the branching microchannels 24, 25, and 26 branch from the microchannel 23.

  As shown in FIGS. 18 and 19, the micro flow path 23 is formed along one straight line on one side of the substrate 21 and the cover 22, and openings 23 a and 23 b serving as inflow ports are formed at both ends. The branch microchannels 24, 25, and 26 branch laterally from the middle branch portion of the microchannel 23 in three directions at substantially the same angle. The branch microchannels 24, 25, and 26 are opened on the side surface of the container 20 and have openings 24 a, 25 a, and 26 a that serve as outlets at the ends.

  When a different liquid is supplied into the microchannel 23 from the openings 23a and 23b, the container 20 configured as described above flows in a laminar flow while maintaining an interface with the different liquid. At this time, if the flow rate of the liquid supplied from the openings 23a and 23b is the same, the liquid sample Ls1 flowing from the opening 23a flows into the branching microchannel 24 while maintaining the concentration, as shown in FIG. . The liquid sample Ls2 flowing in from the opening 23b flows into the branching micro flow channel 26 while maintaining the concentration. The liquid sample Ls1 flowing in from the opening 23a and the liquid sample Ls2 flowing in from the opening 23b flow into the branch microchannel 25 by equal amounts. In the branched microchannel 25, the liquid sample Ls1 and the liquid sample Ls2 flow to the opening 25a while maintaining the interface, and are mixed by molecular diffusion while flowing down.

  At this time, when the drive unit 11 inputs a drive signal to the surface acoustic wave element 14 through the input terminal 14e, the surface acoustic wave element 14 is generated by the sound generation unit 14b or the sound generation unit 14c according to the frequency of the input drive signal. Driven to induce surface acoustic waves (bulk waves). The induced surface acoustic wave (bulk wave) propagates from the acoustic matching layer into the substrate 21 and leaks as a longitudinal wave into a liquid sample having a close acoustic impedance. As a result, the container 20 has two asymmetrical shapes parallel to the branching microchannels 24 and 26, starting from positions corresponding to the sounding portion 14b or the sounding portion 14c in the liquid sample in the branching microchannels 24, 25, and 26. An acoustic flow is generated and the liquid samples Ls1 and Ls2 are agitated.

  At this time, the stirring device 10 switches the frequency of the signal for driving the surface acoustic wave element 14 which is a single sound wave generating element by the driving unit 11 and inputs, for example, a drive signal having the frequency fc1 to the surface acoustic wave element 14. Then, as shown in FIG. 21, the container 20 is parallel to the branch microchannel 24, and has a large cross-sectional area, a high flow velocity, and an acoustic stream S 1 (see FIG. 14) and the branch microchannel 26. Thus, the acoustic flow S2 (see FIG. 14) having a small cross-sectional area and a low flow velocity is generated asymmetrically.

  For this reason, when the liquid sample Ls1 flows into the container 20 from the opening 23a and the liquid sample Ls2 flows into the container 20 from the opening 23b, the interface between the liquid sample Ls1 and the liquid sample Ls2 is broken by the asymmetric acoustic flows S1 and S2. As a result, the container 20 is supplied with the liquid mixture Lm of the liquid sample Ls1 and the liquid sample Ls2 into the branch microchannel 24. At this time, the liquid sample Ls2 flows into the branch microchannel 26, and the liquid mixture of the liquid sample Ls1 and the liquid sample Ls2 having a smaller mixing ratio than the branch microchannel 24 flows into the branch microchannel 25.

  On the other hand, for example, when a drive signal having a frequency fc2 is input to the surface acoustic wave device 14, the container 20 is parallel to the branched microchannel 26 and has a large cross-sectional area and a high flow velocity as shown in FIG. The flow S3 (see FIG. 14) and the acoustic flow S4 (see FIG. 14) that are parallel to the microchannel 24 and have a small cross-sectional area and a low flow velocity are generated asymmetrically. For this reason, when the liquid sample Ls1 flows in from the opening 23a and the liquid sample Ls2 flows in from the opening 23b, the container 20 causes the liquid sample Ls1 and the liquid sample Ls2 to flow into the branch microchannel 26 by the asymmetric acoustic flows S3 and S4. The liquid mixture Lm is supplied. At this time, the liquid sample Ls1 flows into the branch microchannel 24, and the liquid mixture of the liquid sample Ls1 and the liquid sample Ls2 having a larger mixing ratio than the branch microchannel 26 flows into the branch microchannel 25.

  Therefore, the container 20 can change the concentration ratio of the liquid sample flowing into each of the branch microchannels 24, 25, and 26 by switching the frequency of the signal that drives the surface acoustic wave element 14.

  Here, similarly to the container 1 of the first embodiment, the container 20 has the openings 23a and 23b of the microchannel 23 and the branched microflow according to the mode of the acoustic flow generated by the surface acoustic wave element 14 in the liquid sample. Use of the openings 24a, 25a, 26a of the passages 24, 25, 26 as outlets and outlets is arbitrary.

(Modification)
Next, a container used as a micro sorter will be described below as a modification using the characteristics of the container 20 that can change the micro flow path to which the mixed liquid is supplied.

  In the container 30, as shown in FIGS. 23 and 24, a micro flow path 33 and branched micro flow paths 34, 35, and 36 are formed by a substrate 31 and a cover 32. The container 30 is provided with a particle detector 37 on the upper surface of the cover 32 above the microchannel 33, and the substrate 31 and the cover in the vicinity of the branching portion branching from the end of the microchannel 33 to the branching microchannels 34, 35, and 36. The surface acoustic wave element 14 of the stirrer 10 is in contact with the side surfaces of 32 via an acoustic matching layer such as liquid or gel.

  As shown in FIGS. 23 and 24, the micro flow path 33 is formed along one straight line on one side of the substrate 31 and the cover 32, and an opening 33a serving as an inlet for the liquid sample is formed at one end. The branching micro flow channels 34, 35, and 36 branch from the other end of the micro flow channel 33 to the side at approximately the same angle in three directions. The branch microchannels 34, 35, and 36 have openings 34 a, 35 a, and 36 a at the end portions that open on the side surfaces of the container 30 and serve as liquid sample outlets.

  The particle detector 37 is caused by properties such as the surface reaction result (luminescence intensity), size (particle diameter), composition, movement speed, etc. of the particle component contained in the liquid sample flowing down the microchannel 33. For example, optical measurement means such as a photodetector that detects light emitted from the particle component. The particle detector 37 detects an optical signal obtained according to the property of the particle component, and outputs a detection signal to the drive control circuit 13. Here, the drive control circuit 13 selects the driving frequency of the surface acoustic wave element 14 that is a single sound wave generating element based on the detection signal input from the particle detector 37, and the high frequency generated by the signal generator 12. Change the frequency of the signal.

  In the container 30 configured as described above, the surface acoustic wave element 14 is not driven when the particle detector 37 does not detect the optical signal from the particle component contained in the liquid sample supplied from the opening 33a. At this time, as shown in FIG. 25, the liquid sample Ls containing the particle component P flowing down the microchannel 33 is branched into the branching microchannels 34, 35 and 36 and flows down.

  When the drive control circuit 13 selects the drive frequency F = fc1 based on the detection signal input from the particle detector 37, the surface acoustic wave element 14 is driven at the frequency fc1. As a result, as shown in FIG. 26, the container 30 is in parallel with the branching microchannel 34, and is parallel to the branching microchannel 36 and the acoustic flow S1 (see FIG. 14) having a large cross-sectional area and a high flow velocity. The acoustic flow S2 (see FIG. 14) having a small cross-sectional area and a low flow velocity is generated asymmetrically. As a result, the liquid sample Ls containing the reacted particle component P1 flowing down the microchannel 33 has its flow rate flowing to the branching microchannels 34 to the branching microchannels 35 and 36 due to the asymmetric acoustic flows S1 and S2. Increases over flowing flow rate. Therefore, the container 30 can increase the flow rate of the liquid sample Ls containing the particle component P1 to the branch microchannel 34 by driving the surface acoustic wave element 14 at the frequency fc1.

  On the other hand, when the drive control circuit 13 selects the drive frequency F = fc2 based on the detection signal input from the particle detector 37, the surface acoustic wave element 14 is driven at the frequency fc2. As a result, as shown in FIG. 27, the container 30 is parallel to the branching microchannel 36, and is parallel to the branching microchannel 34 and the acoustic flow S3 (see FIG. 14) having a large cross-sectional area and a high flow velocity. In addition, the acoustic flow S4 (see FIG. 14) having a small cross-sectional area and a low flow velocity is generated asymmetrically. As a result, the liquid sample Ls containing the particle component P2 after the reaction flowing down the microchannel 33 has a flow rate flowing to the branching microchannel 36 due to the asymmetric acoustic flows S1 and S2 to the branching microchannels 34 and 35. Increases over flowing flow rate. Therefore, the container 30 can increase the flow rate of the liquid sample Ls containing the particle component P2 to the branch microchannel 36 by driving the surface acoustic wave element 14 at the frequency fc2.

  As described above, the container 30 changes the driving frequency of the surface acoustic wave element 14 so that the liquid sample Ls containing the particle component P1 flows in a large amount and the liquid sample Ls containing the particle component P2 flows in a large amount. Since it can be switched, it can be used as a micro sorter.

  The container 30 may be configured by attaching the surface acoustic wave element 14 to the side surface via an acoustic matching layer such as an epoxy resin. In this case, the surface acoustic wave element 14 is detachably connected between the input terminal 14e and the drive control unit 11, and a drive signal is input. Even if the container 30 is configured in this way, the same effect can be obtained.

  In the surface acoustic wave device of the present invention, the sound generating portions may be formed so that the resonance frequency bands partially overlap and the starting points of the acoustic flow by the adjacent sound generating portions are alternately located. For this reason, as shown in FIG. 28, the surface acoustic wave element 14 as a single sound wave generating element has a center frequency fc3 (fc1 <fc2 <fc3) (MHz) in addition to the sound generating portions 14b and 14c of the center frequencies fc1 and fc2. ) May be connected in parallel. When such a surface acoustic wave element 14 is used, the acoustic flow generated in the liquid sample can be made more complicated.

  Therefore, when such a surface acoustic wave element 14 is used, the stirring device 10 can generate various types of acoustic flows in the liquid sample by appropriately changing the frequency for driving the surface acoustic wave element 14. Therefore, it is possible to efficiently stir the liquid sample according to the amount of liquid while suppressing excessive energy consumption, and it is possible to shorten the time required for stirring.

  The surface acoustic wave element 14 may be driven wirelessly, or the liquid sample may be agitated using surface acoustic waves in addition to bulk waves.

  The “single sound wave generating element” of the present invention, as described above, has acoustic flow origins at two places due to sound waves generated from one sounding part, and a plurality of sounding parts are adjacent to each other. It means any configuration that is formed so that the starting points of the acoustic flow by the sound generating portion are alternately positioned and substantially function as one sound wave generating element. Therefore, even if a plurality of sound generating parts are provided on separate piezoelectric substrates, the structure of the single sound generating element can be functioned as a single component by functioning as a single unit. It can be referred to as a “sound wave generating element”. Depending on the application, the shape and arrangement (dimensions, position), etc., of the plurality of sound generating units may be optimized as appropriate.

It is a perspective view which shows the container which concerns on Embodiment 1 with a stirring apparatus. It is a top view of the container shown in FIG. It is the cross-sectional top view to which the A section of FIG. 2 was expanded. It is a perspective view of the sound wave generating element of the present invention. It is a figure which shows the resonance frequency band of the sound generation part which a part overlaps. FIG. 5 is a frequency characteristic diagram regarding a center frequency and an input reflection coefficient included in a sound generating unit of the surface acoustic wave device of FIG. FIG. 5 is an equivalent circuit diagram of the surface acoustic wave device of FIG. 4. FIG. 8 is an equivalent circuit diagram when the surface acoustic wave device of FIG. 7 is driven at the center frequency of one sounding portion. FIG. 9 is a cross-sectional view illustrating a sound wave generated by each sounding unit in the case of FIG. 8 and an acoustic flow generated in the liquid sample by the sound wave. FIG. 8 is an equivalent circuit diagram when the surface acoustic wave element of FIG. 7 is driven at the center frequency of the other sounding portion. FIG. 11 is a cross-sectional view illustrating a sound wave generated by each sounding unit in the case of FIG. 10 and an acoustic flow generated in the liquid sample by the sound wave. It is a frequency characteristic figure which shows an example of the center frequency and input reflection coefficient which the two sound generation parts which a surface acoustic wave element has. It is the figure which visualized the flow velocity distribution of the acoustic flow which generate | occur | produces when each sound generation part which has the frequency characteristic shown in FIG. 12 is driven by a center frequency. FIG. 5 is a cross-sectional view showing the acoustic flow generated in the liquid sample in the branch microchannel for each driving frequency when the surface acoustic wave device of FIG. 4 is driven. FIG. 4 is a cross-sectional plan view corresponding to FIG. 3 showing an acoustic flow generated in a branched microchannel when a surface acoustic wave element is driven at a frequency equal to the center frequency of one sounding portion. FIG. 4 is a cross-sectional plan view corresponding to FIG. 3 showing an acoustic flow generated in a branched microchannel when a surface acoustic wave element is driven at a frequency equal to the center frequency of the other sounding portion. It is a cross-sectional top view corresponding to FIG. 3 which shows the other attachment method of the surface acoustic wave element attached to the board | substrate bottom face of a container. It is a perspective view which shows the container which concerns on Embodiment 2 with a stirring apparatus. It is a top view of the container shown in FIG. It is the cross-sectional top view which expanded the B section of FIG. FIG. 21 is a cross-sectional plan view corresponding to FIG. 20 showing an acoustic flow generated in a branched microchannel when a surface acoustic wave element is driven at a frequency equal to the center frequency of one sounding portion. FIG. 21 is a cross-sectional plan view corresponding to FIG. 20 showing an acoustic flow generated in a branch microchannel when a surface acoustic wave element is driven at a frequency equal to the center frequency of the other sounding portion. It is a perspective view which shows the container used as a micro sorter with a stirring apparatus as a modification of Embodiment 2. FIG. It is a top view of the container shown in FIG. FIG. 25 is an enlarged cross-sectional plan view of a portion C in FIG. 24 showing the flow of the liquid sample Ls containing the particle component P flowing down the microchannel when the surface acoustic wave element is stopped to the branched microchannel. FIG. 26 is a cross-sectional plan view corresponding to FIG. 25 showing an acoustic flow generated in the branched microchannel when the surface acoustic wave element is driven at a frequency equal to the center frequency of one sounding portion. FIG. 26 is a cross-sectional plan view corresponding to FIG. 25 showing the acoustic flow generated in the branched microchannel when the surface acoustic wave element is driven at a frequency equal to the center frequency of the other sounding portion. It is a front view which shows the other example of a surface acoustic wave element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Container 2 Board | substrate 3 Cover 4 Micro flow path 4a, 4b Opening 5 Branching micro flow path 5a Opening 10 Stirrer 11 Drive part 12 Signal generator 13 Drive control circuit 14 Surface acoustic wave element 14a Piezoelectric board 14b, 14c Sound generation part 140b, 140c Comb electrode (IDT)
140d Comb electrode (IDT)
14e input terminal 14f bus bar 20 container 21 substrate 22 cover 23 micro flow path 24, 25, 26 branch micro flow path 23a, 23b opening 24a, 25a, 26a opening 30 container 31 substrate 32 cover 33 micro flow path 33a opening 34, 35, 36 branching micro flow path 34a, 35a, 36a opening 37 particle detector

Claims (8)

A sound wave generating element having a piezoelectric substrate and a sounding portion disposed on the piezoelectric substrate,
The sound wave generating element characterized in that the plurality of sound generating parts are electrically connected in parallel, the center frequencies of the fundamental waves are different, and a part of the resonance frequency band overlaps.   2. The sound wave generating element according to claim 1, wherein in the plurality of sound generation units, a ratio of a vibration response intensity to an electric input signal of each sound generation unit is changed according to a driving frequency.   The sound generation element according to claim 1, wherein the plurality of sound generation units switch sound generation units that generate sound waves according to the drive frequency.   The sound wave generating element according to claim 1, wherein the driving frequency input to the sound wave generating element is changed based on information on a liquid analysis item, a property of the liquid, or a liquid amount. A container having at least one inlet for allowing liquid to flow into one end of the microchannel, and an outlet formed at the other end of the branched microchannel branched from the microchannel;
A container in which the sound wave generating element according to any one of claims 1 to 4 is provided in the vicinity of a branch portion between the microchannel and the branch microchannel.   The origin of the acoustic flow generated in the micro-channel due to the sound wave generated from the one sounding portion of the sound wave generating element having a plurality of sounding portions is present at two locations apart near the inner wall of the container, 6. The container according to claim 5, wherein the portion is formed so that the starting points of the acoustic flow by the adjacent sound generating portions are alternately positioned. The microchannel and the branched microchannel of a container in which an outlet is formed at the other end of the branch microchannel branched from the microchannel and at least one inlet for allowing liquid to flow into one end of the microchannel The sound wave generating element according to any one of claims 1 to 4, which is provided so as to be in contact with the vicinity of the branch portion of
A drive unit for driving the sound wave generating element;
A stirring apparatus comprising:   The origin of the acoustic flow generated in the micro-channel due to the sound wave generated from the one sounding portion of the sound wave generating element having a plurality of sounding portions is present at two locations apart near the inner wall of the container, The stirrer according to claim 7, wherein the part is formed so that the starting points of the acoustic flow by the adjacent sounding parts are alternately positioned.

Images