JP6090901B2 - Non-contact droplet mixing apparatus and non-contact droplet mixing method - Google Patents

Description

  The present invention relates to a non-contact droplet mixing apparatus and a non-contact droplet mixing method for capturing droplets to be mixed by ultrasonic waves and mixing them in a non-contact manner.

  When conducting tests in the field of drug discovery screening, biotechnology, biochemical reactions of substances, etc., the samples and specimens used in the assay system are mixed in small amounts or mixed into laboratory containers such as microplates. Small amounts are subdivided.

  Conventionally, when mixing a liquid sample or a liquid reagent, the liquid in the reaction vessel in which the sample and the reagent are reacted is stirred using a spatula or screw, so that the liquid after stirring adheres to the spatula or screw. As a result, the inspection of the next sample is carried over and the next sample or sample is contaminated, affecting the analysis result. From the viewpoint of preventing carry-over, a technique for handling a medicine or the like in a non-contact manner is required (for example, see Patent Document 1).

  The inventors of the present invention capture a minute object such as a droplet by ultrasonic standing wave, and convey the captured minute object in a non-contact manner through a linear non-contact conveyance path or a ring-shaped non-contact conveyance path. The technology has been proposed first (for example, see Patent Document 2).

JP-A-8-146007 JP 2011-062068 A

  The object of the present invention is to capture a minute object such as a droplet by the previously proposed ultrasonic standing wave, and to pass the captured minute object through a linear non-contact conveyance path or a ring-shaped non-contact conveyance path. It is another object of the present invention to provide a non-contact droplet mixing apparatus and a non-contact droplet mixing method that do not cause a carry-over by using a non-contact conveying technique.

  Other objects of the present invention and specific advantages obtained by the present invention will become more apparent from the description of embodiments described below.

The present invention includes a flexible diaphragm formed in an annular shape, a circular ring concentric with the flexible diaphragm, and a predetermined predetermined number equal to an integral multiple of a half wavelength of a sound wave in the space facing the flexible diaphragm. A reflector installed in a state of maintaining a gap, an ultrasonic vibrator for exciting the flexible diaphragm, a drive unit for exciting the ultrasonic vibrator by an electric signal, and the ultrasonic vibration by the drive unit Control means for controlling a generation state of an ultrasonic standing wave generated in an annular space sandwiched between the flexible vibration plate and the reflection plate by exciting a child to ultrasonically vibrate the flexible vibration plate; A droplet to be mixed is captured at a plurality of nodes of an ultrasonic standing wave generated in a space sandwiched between the flexural vibration plate and the reflection plate, and the ultrasonic standing wave is captured by the control means. By controlling the occurrence state of A non-contact droplet mixing apparatus for mixing by moving the section portion adjacent droplets to be mixed, captured in the node portions of the standing wave is formed in an annular shape concentric different diameter, and about a horizontal axis It is located above the plurality of nodes of the ultrasonic standing wave generated in the ring-shaped space sandwiched between the circumferential surfaces facing each other of the flexure diaphragm and the reflection plate installed coaxially. By capturing droplets to be mixed at at least two nodes and controlling the generation state of the ultrasonic standing wave by the control means, the mixing target captured at the nodes of the ultrasonic standing wave is controlled. It is characterized in that the droplets are mixed by moving to a node located adjacently below .

Further, the present invention provides a flexible diaphragm formed in an annular shape, and is formed in an annular shape concentric with the flexible diaphragm, and is equal to an integral multiple of a half wavelength of a sound wave in the space facing the flexible diaphragm. Droplets to be mixed at a plurality of nodes of the ultrasonic standing wave generated by ultrasonically vibrating the flexural vibration plate in a space sandwiched between reflection plates installed in a state where a predetermined interval is maintained. The non-contact liquid that moves and mixes the droplets to be mixed captured in the node of the ultrasonic standing wave to the adjacent node by controlling the generation state of the ultrasonic standing wave This is a droplet mixing method, which is formed in an annular shape having concentric and different diameters, and is a ring-shaped sandwiched between the opposing peripheral surfaces of the flexible vibration plate and the reflection plate, which are coaxially arranged around the horizontal axis. Located above multiple nodes of ultrasonic standing wave generated in space The droplets to be mixed are captured at at least two nodes, and the generation state of the ultrasonic standing wave is controlled so that the droplets to be mixed captured at the nodes of the ultrasonic standing wave are It is characterized by being moved and mixed to a node located adjacent to the lower part .

  In the present invention, for example, by controlling the intensity of the ultrasonic standing wave generated in the annular space, the mixing target droplet captured by the node of the ultrasonic standing wave is adjacent to the node. It can be moved to and mixed.

  Further, in the present invention, for example, by controlling the mode of the ultrasonic standing wave generated in the annular space, the droplet to be mixed captured at the node of the ultrasonic standing wave is adjacent. It can be moved to the joint and mixed.

  Furthermore, in the present invention, the flexural diaphragm formed in an annular shape is vibrated at a plurality of locations by the plurality of ultrasonic transducers, and the phase of an electrical signal for exciting the plurality of ultrasonic transducers is controlled. Then, it is possible to propagate the traveling wave ultrasonic vibration in the circumferential direction of the flexural vibration plate and circulate and mix the droplets to be mixed captured at the node of the ultrasonic standing wave.

  In the present invention, a flexible diaphragm formed in an annular shape, and formed in an annular shape having a concentric diameter different from that of the flexible diaphragm, and is equal to an integral multiple of a half wavelength of a sound wave in the space facing the flexible diaphragm. Droplets to be mixed at a plurality of nodes of the ultrasonic standing wave generated by ultrasonically vibrating the flexural vibration plate in a space sandwiched between reflection plates installed in a state where a predetermined interval is maintained. By controlling the generation state of the ultrasonic standing wave, moving the mixing target droplet captured in the node of the ultrasonic standing wave to the adjacent node, and mixing. It is possible to provide a non-contact droplet mixing apparatus and a non-contact droplet mixing method in which droplets to be mixed can be supplemented by ultrasonic waves and mixed in a non-contact manner, and there is no possibility of carryover.

It is a figure which shows typically the structure of the non-contact droplet mixing apparatus to which this invention is applied. It is a figure which shows typically the structure of the linear non-contact conveyance path in the said non-contact droplet mixing apparatus. In the linear non-contact conveyance path, the droplets to be mixed are captured and conveyed at the nodes of the ultrasonic standing wave generated in the linear space sandwiched between the flexible diaphragm and the reflector. It is a figure which shows the state which exists. It is a figure which shows typically the structure of the ring-shaped non-contact conveyance path in the said non-contact droplet mixing apparatus. In the ring-shaped non-contact conveyance path, the droplets to be mixed are captured and conveyed in the node portion of the ultrasonic standing wave generated in the ring-shaped space sandwiched between the flexural vibration plate and the reflection plate. It is a figure which shows a state typically. A non-contact conveyance path configured to generate an ultrasonic standing wave in a semi-cylindrical space sandwiched between a flat-plate-shaped flexible vibration plate to which the present invention is applied and a semi-concentric and different-diameter annular reflector. It is a side view which shows typically the structure of the non-contact droplet mixing apparatus provided. In the said non-contact droplet mixing apparatus, it is a figure which shows typically the sound field mode used in order to capture a some droplet by the ultrasonic standing wave generated in ring-shaped space. It is a figure which shows the progress which capture | acquires and mixes the droplet of the mixing object captured by the node part of an ultrasonic standing wave in the said non-contact droplet mixing apparatus. It is a figure which shows typically the measurement result of the change of the sound pressure by the angle in the non-contact conveyance path of the said non-contact droplet mixing apparatus, ie, the sound field distribution of the circumferential direction. It is a figure which shows typically the relationship between the distance of a diaphragm and a reflecting plate in the non-contact conveyance path of the said non-contact droplet mixing apparatus, and sound pressure. It is a figure which shows the stirring effect of the droplet mixed in the said non-contact droplet mixing apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Needless to say, the present invention is not limited to the following examples, and can be arbitrarily changed without departing from the gist of the present invention.

  The present invention is applied to, for example, a non-contact droplet mixing apparatus 100 configured as shown in FIG.

  The non-contact liquid mixing apparatus 100 includes first to fourth non-contact conveyance paths 10A, 10B, 20, and 30 and a control unit 50 that controls these operations.

  In the non-contact droplet mixing apparatus 100, the first non-contact conveyance path 10A is installed in a horizontal state facing the flexible vibration plate 11A formed in a long flat plate shape and the flexible vibration plate 11A. The reflected reflector 12A, the plurality of ultrasonic transducers 13A for exciting the flexible vibration plate 11A at a plurality of locations in the longitudinal direction, and the plurality of ultrasonic transducers 13A are excited by electrical signals having different phases. It comprises a drive unit 14A.

  The flexible vibration plate 11A and the reflection plate 12A are installed in a horizontal state in which a predetermined interval equal to an integral multiple of the half wavelength of the sound wave between them is held in the vertical direction.

  The first non-contact conveyance path 10A is a linear space sandwiched between the flexible vibration plate 11A and the reflection plate 12A as a non-contact conveyance path for the droplet P1 to be mixed. By exciting the plurality of ultrasonic transducers 13A and ultrasonically vibrating the flexible vibration plate 11A, ultrasonic standing waves generated in a space between the flexible vibration plate 11A and the reflection plate 12A. The droplet P1 to be mixed is captured at the node of the ultrasonic wave, and the phase of the electric signal that excites the plurality of ultrasonic transducers 13A is controlled by the drive unit 14A, thereby the node of the ultrasonic standing wave. The droplet P1 to be mixed captured in (1) is conveyed in the longitudinal direction of the flexible vibration plate 11A.

  In the first non-contact conveyance path 10A, an ultrasonic wave that captures the droplet P1 to be mixed at the conveyance path entrance portion of the linear non-contact conveyance path sandwiched between the flexible vibration plate 11A and the reflection plate 12A. The reflector 12A is provided with an opening 15A that is located above the node of the standing wave and drops the trapped droplet P1 onto the node of the ultrasonic standing wave and captures it. The opening 15A may be a position where the conveyance target is captured, that is, a position close to the acoustic standing wave nodal line.

  The droplet P1 to be mixed introduced into the first non-contact conveyance path 10A through the opening 15A is automatically captured at the position of the acoustic standing wave node, and non-mixed along the linear conveyance path. It is conveyed by contact.

  Then, the first non-contact conveyance path 10 </ b> A non-contact conveys the captured droplet P <b> 1 to be mixed and passes it to the third non-contact conveyance path 20.

  The operation of capturing the droplet P1 to be mixed and the non-contact conveyance in the first non-contact conveyance path 10A is controlled by controlling the operation of the drive unit 14A by the control unit 50.

  Similarly to the first non-contact conveyance path 10A, the second non-contact conveyance path 10B is provided with a flexible vibration plate 11B formed in a long flat plate shape, and is horizontally opposed to the flexible vibration plate 11B. Reflector 12B installed in a stable state, a plurality of ultrasonic transducers 13B for exciting the flexible vibration plate 11A at a plurality of locations in the longitudinal direction, and a plurality of ultrasonic transducers 13B having different phases of electricity. The driving unit 14B is excited by a signal.

  The flexible vibration plate 11B and the reflection plate 1B are horizontally installed with a predetermined interval equal to an integral multiple of a half wavelength of the sound wave between them in the vertical direction.

  The second non-contact conveyance path 10B is a linear space sandwiched between the flexible vibration plate 11B and the reflection plate 12B serving as a non-contact conveyance path for the droplet P2 to be mixed. By exciting the plurality of ultrasonic transducers 13B to ultrasonically vibrate the flexural vibration plate 11B, ultrasonic standing waves generated in the space sandwiched between the flexural vibration plate 11B and the reflection plate 12B are generated. The droplet P2 to be mixed is captured at the node, and the phase of the electric signal for exciting the plurality of ultrasonic transducers 13B is controlled by the drive unit 14B, whereby the node of the ultrasonic standing wave is obtained. The captured droplet P2 to be mixed is conveyed in the longitudinal direction of the flexible vibration plate 11B.

  In the second non-contact conveyance path 10B, an ultrasonic wave that captures the droplet P2 to be mixed at the conveyance path entrance portion of the linear non-contact conveyance path sandwiched between the flexible vibration plate 11B and the reflection plate 12B. The reflector 12B is provided with an opening 15B that is located above the node of the standing wave and that drops and captures the droplet P2 to be mixed onto the node of the ultrasonic standing wave. The opening 15A may be a position where the conveyance target is captured, that is, a position close to the acoustic standing wave nodal line.

  The droplet P2 to be mixed that has been introduced into the second non-contact conveyance path 10B through the opening 15B is automatically captured at the position of the acoustic standing wave node, and is not moved along the straight conveyance path. It is conveyed by contact.

  Then, the second non-contact conveyance path 10 </ b> B non-contact conveys the captured droplet P <b> 2 to be mixed and passes it to the third non-contact conveyance path 20.

  The operation of capturing and non-contact conveyance of the droplet P2 to be mixed in the second non-contact conveyance path 10B is controlled by controlling the operation of the driving unit 14B by the control unit 50.

  In the non-contact droplet mixing apparatus 100, the first non-contact conveyance path 10A and the second non-contact conveyance path 10B are shown in FIG. A duralumin flexural vibration plate 11 is provided, and a pair of ultrasonic vibrators 13A and 13B provided on the connecting plate 112 are connected to both ends of the flexural vibration plate 11 in the longitudinal direction via ultrasonic horns 111A and 111B, respectively. Has been. The ultrasonic horns 111 </ b> A and 111 </ b> B are attached to the flexible diaphragm 11 in a state orthogonal to the longitudinal direction at both ends in the longitudinal direction.

  As the pair of ultrasonic transducers 13A and 13B, for example, so-called bolt-clamped Langevin transducers each having a ring-shaped piezo element that is clamped and fixed by a bolt (not shown) are used, and electric signals for driving are used. Is excited by being applied to the piezo element from the drive unit 14.

  The driving unit 14 generates a two-phase high-frequency signal (first driving signal cos (ωt), second driving signal cos (ωt + θ)) having a frequency of about 20 to 50 kHz as an electric signal for driving. The generator 141 and the two power amplifiers 142A and 142B that amplify the first drive signal cos (ωt) and the second drive signal cos (ωt + θ) and supply the amplified signal to the pair of ultrasonic transducers 13A and 13B. And a phase controller 143 that variably controls the phase θ of the second drive signal cos (ωt + θ).

  In the non-contact conveyance path 10, high-frequency signals (first drive signal cos (ωt), second drive signal cos (ωt + θ)) having a frequency of about 20 to 50 kHz are supplied from the drive unit 40 as electric signals for driving. The ultrasonic vibrations of the pair of ultrasonic vibrators 13A and 13B excited by being supplied to the pair of ultrasonic vibrators 13A and 13B are amplified by the ultrasonic horns 111A and 111B, respectively, and the flexural vibration is obtained. Applied to the plate 11. Thereby, the flexural vibration can be excited in the flexural vibration plate 11 at several resonance frequencies.

  Here, the pair of ultrasonic vibrators 13A and 13B is efficient when the position of the antinode in the free vibration of the flexible diaphragm 11 is vibrated at two places in the longitudinal direction of the flexible diaphragm 11. The flexural vibration can be excited in the flexural vibration plate 11.

  And in this non-contact conveyance path 10, since the said flexure diaphragm 11 and the reflecting plate 12 oppose and are installed in the state which hold | maintained the predetermined space | interval equal to the integral multiple of the half wavelength of the sound wave between these. Then, the pair of ultrasonic transducers are excited by the drive unit 14 to ultrasonically vibrate the flexible vibration plate 11, so that the ultrasonic wave is fixed in a space between the flexible vibration plate 11 and the reflection plate 12. A standing wave is formed, and as shown in FIG. 3, the droplet P to be mixed can be captured at the node of this ultrasonic standing wave. The drive unit 14 excites the pair of ultrasonic transducers, that is, a high-frequency signal having a frequency of about 20 to 50 kHz (a first drive signal cos (ωt), a second drive signal cos ( By controlling the phase difference of (ωt + θ)), it is possible to control the direction and intensity of the flexural wave propagating through the flexural vibration plate 11, and in the non-contact conveyance path 10, the second drive signal By variably controlling the phase θ of cos (ωt + θ) by the phase control unit 43, the position of the node of the ultrasonic standing wave formed in the space sandwiched between the flexible vibration plate 11 and the reflection plate 12 is reflected. It is possible to control the spatial position of the droplet P to be mixed captured in the node of the ultrasonic standing wave by changing it to an arbitrary position and direction on one dimension in the longitudinal direction of the plate 12. The second drive by the phase controller 143 By continuously changing the phase θ of the signal cos (ωt + θ), the flexible vibration plate 10 is ultrasonically vibrated in the traveling wave, and the droplet P to be mixed captured at the node of the ultrasonic standing wave is Non-contact conveyance is possible in the longitudinal direction of the flexible vibration plate 11. A linear horizontal space sandwiched between the flexural vibration plate 11 and the reflection plate 12 serves as a transport path for the droplets P to be mixed.

  In this non-contact conveyance path 10, a pair of ultrasonic transducers 13A and 13B is excited by an electric signal, and a flexural vibration plate 11 formed in a long flat plate shape is vibrated at two locations in the longitudinal direction. The ultrasonic wave is caused to vibrate, the droplet P to be mixed is captured at the node of the ultrasonic standing wave generated in the space sandwiched between the flexural vibration plate 11 and the reflection plate 12, and the pair of ultrasonic vibrations. As shown in FIG. 3, by controlling the phase of the electrical signals that excite the sub-elements 13A and 13B, the flexural vibration plate 11 is ultrasonically vibrated in the traveling wave and is mixed in the node portion of the ultrasonic standing wave. The target droplet P can be conveyed in the longitudinal direction of the flexible vibration plate 11.

  Here, the reflecting plate 12 may be any material that sufficiently reflects sound waves, and a general aluminum plate or acrylic plate having a thickness of about 1 mm can be used.

  Further, in the non-contact droplet mixing apparatus 100, the third non-contact conveyance path 20 includes a ring-shaped flexible vibration plate 21 and a reflection plate installed in a horizontal state so as to face the flexible vibration plate 21. 22, a plurality of ultrasonic vibrators 23 that vibrate the flexural diaphragm 21 at a plurality of locations in the circumferential direction, and a drive unit 24 that excites the plurality of ultrasonic vibrators 23 using electrical signals of different phases. With.

  The flexible vibration plate 21 and the reflection plate 22 are installed in a horizontal state in which a predetermined interval equal to an integral multiple of a half wavelength of a sound wave between them is held in the vertical direction.

  The third non-contact conveyance path 20 is a ring-shaped space sandwiched between the flexural vibration plate 21 and the reflection plate 22 as a non-contact conveyance path for the droplet P to be mixed. By exciting the plurality of ultrasonic vibrators to ultrasonically vibrate the flexural vibration plate 21, ultrasonic standing waves generated in the space between the flexural vibration plate 21 and the reflection plate 22 are generated. The droplet P to be mixed is captured at the node, and the phase of the electrical signal that excites the plurality of ultrasonic transducers 23 is controlled by the drive unit 24, so that the node of the ultrasonic standing wave is The captured droplet P to be mixed is conveyed in the circumferential direction of the flexible vibration plate 21.

  As shown in FIG. 4, a specific configuration example of the third non-contact conveyance path 20 includes, for example, two pairs of ultrasonic transducers 23A, 23B, 123A, which use so-called bolted Langevin transducers. 123B. The drive unit 24 includes four-phase high-frequency signals having a frequency of about 20 to 50 kHz (first drive signal cos (ωt), second drive signal cos (ωt + π), third drive signal sin (ωt), 4 drive signal sin (ωt + π)) is used as a drive electric signal, and the ultrasonic vibrators 23A and 23B are sent to the ultrasonic transducers 23A and 23B at opposite positions in the circumferential direction of the ring-shaped flexible diaphragm 21 (first phase). 1 drive signal cos (ωt), second drive signal cos (ωt + π)), and ultrasonic transducers 123A and 123B are made to have high-frequency signals of opposite phase (third drive signal sin (ωt), second 4, the traveling wave ultrasonic vibration of the flexible vibration plate 21 circulates as shown in FIG. 5, and the object to be mixed along the ring-shaped conveyance path as shown in FIG. 5. Droplets P1 and P2 can be conveyed.

  In the non-contact droplet mixing apparatus 100, the third non-contact conveyance path 20 includes the droplet P1 to be mixed that is non-contact conveyed via the first non-contact conveyance path 10A and the second non-contact conveyance path 10A. A plurality of ultrasonic standing waves generated in a space sandwiched between the flexural vibration plate 21 and the reflection plate 22 are mixed droplets P2 that are transported in a non-contact manner through the non-contact transport path 10B. After the droplets P1 and P2 to be mixed are captured and received individually at the nodes, the droplets P1 and P2 to be mixed are transported at high speed along the ring-shaped transport path.

  In the third non-contact conveyance path 20, the droplets P1 and P2 to be mixed captured by the plurality of nodes of the ultrasonic standing wave are conveyed at high speed along the ring-shaped conveyance path. As a result, they are mixed and dispersed and captured in a plurality of nodes.

  Then, the droplet P3 obtained by mixing the droplets P1 and P2 obtained by the high-speed non-contact conveyance operation is non-contact conveyed along the ring-shaped conveyance path of the third non-contact conveyance path 20, and the second It is delivered from the non-contact conveyance path 20 to the fourth non-contact conveyance path 30.

  The controller 50 controls the drive unit to capture the droplets P1 and P2 to be mixed in the third non-contact conveyance path 20, the high-speed non-contact conveyance operation for mixing, and the non-contact conveyance operation for delivery. 24 is controlled, and the excitation frequency and excitation intensity of the ultrasonic vibrator 23 are appropriately controlled according to the amount and viscosity of the droplets P1 and P2 to be mixed.

  The fourth non-contact conveyance path 30 is formed in a long flat plate shape, a linear deflection vibration plate 31, a reflection plate 32 installed in a horizontal state so as to face the deflection vibration plate 31, and the above A plurality of ultrasonic vibrators 33 that vibrate the flexural vibration plate 31 at a plurality of locations in the longitudinal direction, and a drive unit 34 that excites the plurality of ultrasonic vibrators 33 with electrical signals having different phases.

  The flexural vibration plate 31 and the reflection plate 32 are installed horizontally and at a predetermined interval equal to an integral multiple of half the wavelength of the sound wave between them.

  The fourth non-contact conveyance path 30 is a non-contact conveyance path for the droplet P3 delivered from the third non-contact conveyance path 20 through a linear space sandwiched between the flexible vibration plate 31 and the reflection plate 32. The drive unit 34 excites the plurality of ultrasonic transducers 33 to ultrasonically vibrate the flexural vibration plate 31, thereby sandwiching the flexure vibration plate 31 and the reflection plate 32. The droplet P3 is captured at the node of the ultrasonic standing wave generated in the space, and the phase of the electrical signal for exciting the plurality of ultrasonic transducers 33 is controlled by the driving unit 34, thereby The droplet P3 captured at the node of the ultrasonic standing wave is conveyed in the longitudinal direction of the flexible diaphragm 31.

  In the fourth non-contact conveyance path 30, the superposition that captures the mixed droplet P <b> 3 at the conveyance path exit portion of the linear non-contact conveyance path sandwiched between the flexible vibration plate 31 and the reflection plate 32. The reflection plate 32 is provided with an opening 35 located below the node of the sonic standing wave and for dropping the droplet P3 from the node of the ultrasonic standing wave.

  Then, the droplet P3 transported in a non-contact manner via the fourth non-contact transport path 30 captures the droplet P3 at a node portion at the transport path exit portion of the fourth non-contact transport path 30. By stopping the generation of the standing ultrasonic wave and capturing it, it is dropped below the node and taken out through the opening 35.

  Here, in the non-contact droplet mixing apparatus 100, the first to fourth non-contact conveyance paths 10A, 10B, 20, and 30 include the flexible vibration plates 11A, 11B, 21, and 31 and the reflection plates 12A, 12B, 22 and 32 are installed in a horizontal state in which a predetermined interval equal to an integral multiple of the half wavelength of the sound wave between them is maintained in the vertical direction, but each of the flexural vibration plates 11A, 11B, 21, 31 and the reflection plate Even if 12A, 12B, 22 and 32 are installed in a vertical state in which a predetermined interval equal to an integral multiple of the half wavelength of the sound wave between them is held in the horizontal direction, the droplet P to be mixed is a nodal portion. Can be captured and transported in a non-contact manner. In this case, the openings 15A and 15B for dropping and capturing the droplets P1 and P2 to be mixed on the nodes of the ultrasonic standing wave and the openings 35 for taking out the mixed droplet P3 may be omitted. it can.

  Further, like the non-contact droplet mixing apparatus 200 shown in FIG. 6, the flexural vibration plate 111 and the reflection plate 112 which are formed concentrically and annularly in an annular shape and are arranged coaxially with the horizontal axis as the center are opposed to each other. The droplets P1 and P2 to be mixed are captured in at least two nodes located above the plurality of nodes of the ultrasonic standing wave generated in the ring-shaped space sandwiched between the surrounding surfaces. By controlling the state of generation of the ultrasonic standing wave, the droplets P1 and P2 to be mixed captured in the node of the ultrasonic standing wave are moved to the node located adjacent to the lower side. It can also be mixed.

  The non-contact droplet mixing apparatus 200 includes an annular flexural vibration plate 121, a concentric / different diameter annular reflective plate 122 whose outer peripheral surface faces the flexural vibration plate 311, and the flexural vibration plate 221. It comprises an ultrasonic transducer 123 that vibrates from the outer periphery, a drive unit 124 that excites the ultrasonic transducer 123 with an electrical signal, and a control unit 125 that controls the operation of the drive unit 124.

  In this non-contact droplet mixing apparatus 200, an aluminum ring having an inner diameter of 53 mm and an outer diameter of 61.5 mm is used for the annular flexural vibration plate 121, and an inner diameter of 28 mm and an outer diameter of 38 mm are used for the reflector 122. An acrylic ring was used. A 25.9 kHz respiratory vibration is excited by a bolted Langevin vibrator 123 having an ultrasonic horn 123A whose tip is fixed to the outer peripheral surface of the flexible diaphragm 121 by a cap bolt, and the flexible diaphragm 211 and the reflection are reflected. By generating an ultrasonic standing wave in a ring-shaped space sandwiched between opposing circumferential surfaces of the plate 212, at least two locations located above the plurality of nodes of the ultrasonic standing wave are provided. The droplets P1 and P2 to be mixed can be captured at the nodes, and the non-contact conveyance path 120 by the ultrasonic standing wave generated in the ring-shaped space is configured.

  The droplets P1 and P2 to be mixed are captured by being individually introduced into two nodes located above the plurality of nodes of the ultrasonic standing wave in an atomized state. And condensed.

  In this non-contact droplet mixing apparatus 200, in order to capture a plurality of droplets P1 and P2 by ultrasonic standing waves generated in a ring-shaped space, one nodal circle and 12 as shown in FIG. The sound field mode with the tangent line was used.

  In the non-contact droplet mixing apparatus 200, an experiment was performed using water as the droplets P1 and P2 to be mixed. As a result, the mixing target was near the node of the ultrasonic standing wave generated in the ring-shaped space. By atomizing the liquid, the two droplets P1 and P2 can be captured at the nodes and separately levitated, and by controlling the generation state of the ultrasonic standing wave, (A) in FIG. , (B), (C), (D), the droplets P1 and P2 to be mixed, which are captured in the nodes of the ultrasonic standing wave, are moved to the nodes located adjacently below. Could be mixed.

Here, as a method of mixing two droplets P1 and P2 trapped in two nodes and separately levitated,
(1) A method of generating a circumferential traveling wave by exciting the retraction mode with a 90 ° phase difference (2) A method of changing the sound field mode by switching the driving frequency during levitation (3) Moving the transducer or reflector (4) There is a method of changing the sound field strength or the sound field mode by modulating the drive voltage.

  In the non-contact droplet mixing device 200, the method (3) is adopted, and the sound field intensity or the sound field mode is changed by moving the diaphragm 311.

  FIG. 8A shows a state in which the droplets P1 and P2 are captured and floated separately at two nodes in the non-contact droplet mixing apparatus 200.

  FIG. 8B shows the non-contact droplet mixing apparatus 200 in which droplets P1, P2 are shaken by shaking the vibrator 211 in a state where the droplets P1, P2 are captured and floated separately at two nodes. P2 is moved.

  FIG. 8C shows a state in which in the non-contact droplet mixing apparatus 200, the droplets P1 and P2 are moved by shaking the vibrator 121 so that the two droplets P1 and P2 come into contact with each other and are combined with the surface tension. Show.

  FIG. 8D shows a mixed state of two droplets P1 and P2 in the non-contact droplet mixing apparatus 200. FIG.

  Here, with respect to the non-contact conveyance path 120 by the ultrasonic standing wave generated in the ring-shaped space in the non-contact droplet mixing apparatus 200, the sound field distribution measurement was performed using a laser Doppler vibrometer. FIG. 9 shows a change in sound pressure with angle, that is, a circumferential sound field distribution. That is, when the distance L between the vibration plate 121 and the reflection plate 122 at an angle of 90 ° is 7.5 mm and 10 mm, the sound pressure is larger when L = 7.5 mm with the center aligned. In the vicinity of 90 ° where mixing is performed, the movement of the nodes due to the change in the distance L is hardly observed.

  Further, the relationship between the distance L between the diaphragm 121 and the reflector 122 and the sound pressure is shown in FIG. In the non-contact droplet mixing apparatus 200, the maximum sound pressure changes greatly before and after L = 7 mm, and when the diaphragm 121 is lowered, the sound pressure temporarily decreases and the acoustic radiation force decreases. The mixture is moved in the circumferential direction by gravity. Thereafter, when the diaphragm 121 returns to its original position, the sound pressure increases again and is captured by a strong sound field in the 90 ° direction.

The relationship between the sound pressure p and the measured particle velocity ν _LDV is expressed by the following equation (1).

become that way.

  In equation (1), n is the refractive index of air, ρ is the density of air, l is the length of the sound field, c is the speed of sound (in the air, 15 ° C., light wavelength 633 nm, 1 atm, l = 30 mm) Calculated.)

  In the non-contact droplet mixing apparatus 200, the liquid is captured and floated as droplets P at the nodes in the non-contact conveyance path 120 by the ultrasonic standing wave generated in the ring-shaped space. FIGS. 11A, 11B, and 11C show changes in time observed by adding a small amount of water-based ink to the droplet P. FIG.

  The droplet P captured and levitated at the node is rotating, and immediately after the water-based ink is added, it remains at the center of the droplet P as shown in FIG. Thereafter, as shown in FIG. 11C, the ink in the central portion diffuses throughout.

  Therefore, the non-contact droplet mixing devices 100 and 200 have an effect of stirring the liquid P3 in which the two droplets P1 and P2 are mixed.

  10A, 10B, 20, 30, 120 Non-contact carrying path, 11A, 11B, 21, 31, 131, 121 Deflection diaphragm, 12A, 12B, 22, 32, 122 Reflector, 13, 13A, 13B, 23, 23A , 23B, 33, 123 Ultrasonic vibrator, 14A, 14B, 24, 34, 124 Drive unit, 50, 125 Control unit, 100, 200 Non-contact droplet mixing device, P1, P2, P3 droplets

Claims (8)

A flexural diaphragm formed in an annular shape, and formed in an annular shape concentric with the flexural vibration plate, and opposed to the flexural diaphragm, and maintained a predetermined interval equal to an integral multiple of half the wavelength of sound waves in the space. A reflector installed in a state, an ultrasonic vibrator for exciting the flexible vibration plate, a drive unit for exciting the ultrasonic vibrator with an electric signal, and the ultrasonic vibrator is excited by the drive unit. Control means for controlling a generation state of an ultrasonic standing wave generated in an annular space sandwiched between the flexible vibration plate and the reflection plate by ultrasonically vibrating the flexible vibration plate, The droplet to be mixed is captured at a plurality of nodes of the ultrasonic standing wave generated in the space between the flexural vibration plate and the reflection plate, and the generation state of the ultrasonic standing wave is determined by the control means. By controlling the above ultrasonic standing wave The mixture target droplets captured in part a non-contact droplet mixing apparatus for mixing by moving the section portion adjacent,
Ultrasound generated in a ring-shaped space formed between concentric and annular rings, which are arranged coaxially with a horizontal axis as the center and sandwiched between the opposing peripheral surfaces of the reflecting plate and the reflecting plate Capturing droplets to be mixed in at least two nodes located above the plurality of nodes of the standing wave;
By controlling the generation state of the ultrasonic standing wave with the control means, the droplet to be mixed captured in the node of the ultrasonic standing wave is moved to the node located adjacent to the lower side. A non-contact droplet mixing apparatus characterized by mixing .   The control means controls the intensity of the ultrasonic standing wave generated in the annular space, so that the droplet to be mixed captured in the node of the ultrasonic standing wave is applied to the adjacent node. The non-contact droplet mixing apparatus according to claim 1, wherein the mixing is performed by moving.   The control means controls the mode of the ultrasonic standing wave generated in the annular space, so that the droplet to be mixed captured in the node of the ultrasonic standing wave is placed in the adjacent node. The non-contact droplet mixing apparatus according to claim 1, wherein the mixing is performed by moving. Exciting the flexural diaphragm formed in the annular shape at a plurality of locations by a plurality of the ultrasonic transducers,
The control means controls the phase of an electrical signal that excites the plurality of ultrasonic transducers by the driving unit, propagates traveling wave ultrasonic vibration in the circumferential direction of the flexible diaphragm, and The non-contact droplet mixing apparatus according to claim 1, wherein the droplets to be mixed captured by the wave node are circulated and mixed. A flexural diaphragm formed in an annular shape, and formed in an annular shape concentric with the flexural vibration plate, and opposed to the flexural diaphragm, and maintained a predetermined interval equal to an integral multiple of half the wavelength of sound waves in the space. In the space between the reflectors installed in a state, the liquid droplets to be mixed are captured at a plurality of nodes of the ultrasonic standing wave generated by ultrasonically vibrating the flexural vibration plate, A non-contact droplet mixing method in which a droplet to be mixed captured by a node portion of the ultrasonic standing wave is moved to an adjacent node portion and mixed by controlling a generation state of the sonic standing wave. ,
Ultrasound generated in a ring-shaped space formed between concentric and annular rings, which are arranged coaxially with a horizontal axis as the center and sandwiched between the opposing peripheral surfaces of the reflecting plate and the reflecting plate Capturing droplets to be mixed in at least two nodes located above the plurality of nodes of the standing wave;
By controlling the generation state of the ultrasonic standing wave, the droplet to be mixed captured in the node of the ultrasonic standing wave is moved to the node located adjacent below and mixed. A non-contact droplet mixing method. By controlling the intensity of the ultrasonic standing wave generated in the annular space, the droplet to be mixed captured in the node of the ultrasonic standing wave is moved to the adjacent node and mixed. The non-contact droplet mixing method according to claim 5 . By controlling the mode of the ultrasonic standing wave generated in the annular space, the droplet to be mixed captured in the node of the ultrasonic standing wave is moved to the adjacent node and mixed. The non-contact droplet mixing method according to claim 5 . Exciting the flexural diaphragm formed in the annular shape at a plurality of locations by a plurality of the ultrasonic transducers,
Controlling the phase of the electrical signal that excites the plurality of ultrasonic transducers, propagating the traveling-wave ultrasonic vibration in the circumferential direction of the flexural vibration plate, and mixing target captured at the node of the ultrasonic standing wave The non-contact droplet mixing method according to claim 5 , wherein the droplets are circulated and mixed.