Fine particle collecting apparatus

Abstract

To provide a technique for easily increasing the intensity of ultrasonic waves for focusing fine particles.SOLUTION: The fine particle collecting device 10 includes a flow channel constituting part 20 constituting a flow channel 21 in which a liquid L flows, an ultrasonic wave generation source 30 for generating ultrasonic waves, an ultrasonic wave focusing part 40, and a transmission part 50. The ultrasonic wave focusing unit 40 has a reflection surface 41 that reflects the ultrasonic waves generated from the ultrasonic wave generator 30. The transmission unit 50 connects the ultrasonic wave focusing unit 40 and the flow path constituting part 20. The ultrasonic wave generation source 30 generates a longitudinal ultrasonic wave. The reflection surface 41 is curved so as to convert the longitudinal ultrasonic wave generated from the ultrasonic wave generation source 30 into the transverse ultrasonic wave and converge the converted transverse ultrasonic wave toward the transmission portion 50. In the fine particle collecting apparatus 10, ultrasonic waves are transmitted from the transmission part 50 to the liquid L.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to particle focusing devices. [Background technology]

[0002] Conventionally, there is known a technique for focusing fine particles in a fluid by using ultrasonic waves (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-26105 [Patent Document 2] Japanese Patent Application Publication No. 2023-37337 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Documents 1 and 2, the ultrasonic waves generated from the ultrasonic element are propagated directly into the liquid, and no consideration is given to increasing the intensity of the ultrasonic waves that focus the microparticles.

[0005] The present disclosure aims to provide a technique that makes it easy to increase the intensity of ultrasound that focuses microparticles. [Means for solving the problem]

[0006] The particle focusing device of the present disclosure comprises: a flow path forming portion that forms a flow path through which a liquid flows; an ultrasonic wave generating source that generates ultrasonic waves, A particle focusing device that focuses particles in the liquid by applying ultrasonic waves to the liquid, an ultrasonic focusing unit having a reflecting surface that reflects the ultrasonic waves generated from the ultrasonic generation source; a transmission unit connecting the ultrasonic focusing unit and the flow path configuration unit; Equipped with The ultrasonic wave generating source generates longitudinal ultrasonic waves, The reflecting surface is curved so as to convert the longitudinal ultrasonic waves generated from the ultrasonic wave generation source into transverse ultrasonic waves and to focus the converted transverse ultrasonic waves toward the transmitting section, Ultrasonic waves are transmitted from the transmission section to the liquid. [Effects of the Invention]

[0007] According to the present disclosure, it is easy to increase the intensity of the ultrasound that focuses the microparticles. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional perspective view of a particle focusing device according to the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the particle focusing device of the first embodiment. [Figure 3] FIG. 3 is a graph showing the relationship between the angle of incidence and the energy conversion rate from longitudinal waves to shear waves. [Figure 4] FIG. 4 is an explanatory diagram showing a state in which a node is formed in the center of the flow channel in the third direction. [Figure 5] FIG. 5 is an explanatory diagram showing how the particles in the liquid are focused at the center in the third direction and guided to the separation channel. [Figure 6] FIG. 6 is an explanatory diagram showing a state in which a node is formed in the center of the flow channel in the second direction. [Figure 7] FIG. 7 is a cross-sectional view of the particle focusing device of the second embodiment. [Figure 8] FIG. 8 is a cross-sectional view of the particle focusing device of the third embodiment. [Figure 9] FIG. 9 is a cross-sectional view of the particle focusing device of the fourth embodiment. [Figure 10] FIG. 10 is a cross-sectional view of the particle focusing device of the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Description of the embodiments of the present disclosure] In the following, embodiments of the present disclosure are listed and illustrated.

[0010] [1] A flow path forming portion that forms a flow path through which a liquid flows; an ultrasonic wave generating source that generates ultrasonic waves, A particle focusing device that focuses particles in the liquid by applying ultrasonic waves to the liquid, an ultrasonic focusing unit having a reflecting surface that reflects the ultrasonic waves generated from the ultrasonic generation source; a transmission unit connecting the ultrasonic focusing unit and the flow path configuration unit; Equipped with The ultrasonic wave generating source generates longitudinal ultrasonic waves, The reflecting surface is curved so as to convert the longitudinal ultrasonic waves generated from the ultrasonic wave generation source into transverse ultrasonic waves and to focus the converted transverse ultrasonic waves toward the transmitting section, The ultrasonic wave is transmitted from the transmitting portion to the liquid. Particle focusing device.

[0011] According to this configuration, ultrasonic waves generated from the ultrasonic source are reflected by the reflecting surface of the ultrasonic focusing unit. The reflecting surface converts the longitudinal ultrasonic waves generated from the ultrasonic source into shear ultrasonic waves and focuses the converted shear ultrasonic waves toward the transmitting unit. The particle focusing device focuses particles in the liquid using the shear ultrasonic waves focused toward the transmitting unit. In other words, according to this configuration, it is easy to increase the intensity of the ultrasonic waves that focus the particles.

[0012] [2] The transmitting section vibrates upon receiving ultrasonic transverse waves focused toward itself, and generates ultrasonic longitudinal waves in the flow path, thereby focusing the particles in the liquid. The particle focusing device according to [1].

[0013] The particle focusing device can generate longitudinal ultrasonic waves at the transmission part by utilizing the transverse ultrasonic waves focused toward the transmission part, and can focus particles in the liquid flowing through the flow path by the longitudinal ultrasonic waves generated from the transmission part.

[0014] [3] The reflecting surface has a shape along an ellipse in a cross section cut in a direction perpendicular to the direction in which the flow path extends, and the ratio of the major axis to the minor axis of the ellipse satisfies the condition of the following formula (1). The particle focusing device according to [1] or [2]. Major axis: Minor axis = CDA: √(CDA 2 -CTA 2 )...Equation (1) CDA is the propagation velocity of the longitudinal wave incident on the reflecting surface. CTA is the propagation speed of the transverse wave generated at the reflecting surface.

[0015] According to this configuration, the ultrasonic waves converted into shear waves by the reflecting surface can be focused onto a focal point.

[0016] [4] The ultrasonic wave generating source is a one-side generation unit disposed on one side of the flow path in a second direction perpendicular to a first direction in which the flow path extends; a second-side generating portion disposed on the other side of the flow path in the second direction, The ultrasonic focusing unit a one-side converging portion disposed on one side of the flow path in the second direction; an other-side converging portion disposed on the other side of the flow path in the second direction, the reflecting surface includes a one-side reflecting surface provided on the one-side focusing portion and a second-side reflecting surface provided on the second-side focusing portion, the transmission section is disposed between the one-side focusing section and the other-side focusing section, and is configured to connect the one-side focusing section and the other-side focusing section; the one-side generating unit and the other-side generating unit each generate longitudinal ultrasonic waves, the one-side reflecting surface is curved to convert the longitudinal ultrasonic waves generated from the one-side generating unit into shear waves and to focus the converted shear waves toward the transmitting unit, The other-side reflecting surface is curved so as to convert the longitudinal ultrasonic waves generated from the other-side generating portion into shear waves and to focus the converted shear waves toward the transmitting portion. The particle focusing device according to [2].

[0017] With this configuration, ultrasonic waves generated on both sides in the second direction can be focused toward the transmitting section, which causes the transmitting section to vibrate more, increases the intensity of ultrasonic waves generated in the flow channel, and improves the focusing performance of the particles.

[0018] [5] The ultrasonic wave generation in a second direction perpendicular to the first direction in which the flow path extends. The source and the ultrasonic focusing unit are disposed on the opposite side of the flow path configuration unit with the transmission unit interposed therebetween. are placed, The reflecting surface converts the longitudinal ultrasonic waves generated from the ultrasonic wave generation source into shear waves and focuses the converted shear waves at a focal point located closer to the flow path configuration unit than the center of the transmitting unit in the orthogonal direction. The particle focusing device according to [1].

[0019] This configuration allows the ultrasonic transverse waves to be focused at a position close to the flow path component, thereby increasing the vibration of the transmission section at a position close to the flow path component, thereby increasing the intensity of the ultrasonic waves generated in the flow path and improving the focusing performance of the particles.

[0020] [6] The ultrasonic wave generating source generates ultrasonic waves toward one side in a third direction perpendicular to a first direction in which the flow path extends, the ultrasonic reflecting surface reflects the longitudinal ultrasonic waves generated from the ultrasonic generation source and converts them into shear waves, and focuses the converted shear waves at a focal point located on the other side of the center of the transmission section in the third direction, The flow path configuration portion is disposed on the other side of the transmission portion in the third direction. The particle focusing device according to [2].

[0021] This configuration allows the ultrasonic transverse waves to be focused at a position close to the flow path component, thereby increasing the vibration of the transmission section at a position close to the flow path component, thereby increasing the intensity of the ultrasonic waves generated in the flow path and improving the focusing performance of the particles.

[0022] [7] The flow path forming portion is made of a permeable material. The particle focusing device according to any one of [1] to [6].

[0023] According to this configuration, a user can view the flow path from outside the flow path forming unit, and can visually confirm the focusing state of the particles in the flow path.

[0024] [Details of the embodiments of the present disclosure] The particle focusing device of the present disclosure can be used, for example, for blood separation (separation of plasma and blood cells from blood), cell separation (selective separation of cells from cell culture fluid), catalyst separation (separation of catalysts after reaction), nanoparticle dispersion (separation of nanoparticles from liquid), fine powder separation (efficient recovery of fine solid powders from chemical reaction products), drug purification (removal of impurities during pharmaceutical manufacturing), and biopharmaceutical purification (separation of impurities in the manufacture of protein formulations and vaccines).

[0025] 1. First embodiment 1 and 2 show a particle focusing device 10 of a first embodiment. The particle focusing device 10 includes a flow path configuration section 20. The flow path configuration section 20 configures a flow path 21. The flow path 21 extends along a first direction. The particle focusing device 10 is a device that generates ultrasonic waves in the flow path 21 to focus particles 90 in a liquid L flowing through the flow path 21 (see FIG. 5).

[0026] The particle focusing device 10 includes an ultrasonic wave generating source 30, an ultrasonic wave focusing unit 40, a transmission unit 50, a power source P, and a control unit 60.

[0027] The ultrasonic wave generating source 30 generates longitudinal ultrasonic waves. The ultrasonic wave generating source 30 is configured by, for example, a piezoelectric element. The piezoelectric element has a piezoelectric body 31 and electrodes 32, 33 arranged on both sides of the piezoelectric body 31. The piezoelectric body 31 is made of ceramics such as lead zirconate titanate (PZT) or potassium sodium niobate (KNN). The ultrasonic wave generating source 30 is plate-shaped. When an AC voltage based on a power source P is applied to the ultrasonic wave generating source 30, the ultrasonic wave generating source 30 generates longitudinal ultrasonic waves in the thickness direction of the plate itself. The ultrasonic wave generating source 30 generates ultrasonic waves at a frequency of, for example, 30 kHz or more and 10 MHz or less.

[0028] The ultrasonic wave generating source 30 has a one-side generating unit 30A and an other-side generating unit 30B. The one-side generating unit 30A and the other-side generating unit 30B are each composed of a piezoelectric element. The one-side generating unit 30A is arranged on one side of the flow path 21 in a second direction perpendicular to the first direction. The other-side generating unit 30B is arranged on the other side of the flow path 21 in the second direction. The one-side generating unit 30A and the other-side generating unit 30B are each plate-shaped and extend along the first and second directions. The one-side generating unit 30A and the other-side generating unit 30B each generate longitudinal ultrasonic waves on one side in a third direction perpendicular to the first and second directions.

[0029] The ultrasonic generating source 30 (specifically, the one-side generating unit 30A and the other-side generating unit 30B) is joined to the other surface in the third direction of the ultrasonic focusing unit 40. In this specification, "joined" is not limited to a direct joining configuration, but also includes a joining configuration via another member.

[0030] The ultrasonic focusing unit 40 focuses the ultrasonic waves generated from the ultrasonic generation source 30. The ultrasonic focusing unit 40 is formed of, for example, a metal (e.g., duralumin). The ultrasonic focusing unit 40 has a reflecting surface 41 that reflects the ultrasonic waves generated from the ultrasonic generation source 30. The reflecting surface 41 is curved so as to protrude on the side opposite to the ultrasonic generation source 30. The reflecting surface 41 is curved so as to convert the longitudinal ultrasonic waves generated from the ultrasonic generation source 30 into shear ultrasonic waves and focus the converted shear ultrasonic waves toward the transmitting unit 50.

[0031] The ultrasonic focusing section 40 has a one-side focusing section 40A and an other-side focusing section 40B. The one-side focusing section 40A is arranged on one side of the flow path 21 in the second direction. The other-side focusing section 40B is arranged on the other side of the flow path 21 in the second direction. The one-side focusing section 40A and the other-side focusing section 40B have a shape that is wide in the first direction.

[0032] The reflecting surface 41 has a one-side reflecting surface 41A and an other-side reflecting surface 41B. The one-side reflecting surface 41A is provided on the one-side focusing portion 40A. The other-side reflecting surface 41B is provided on the other-side focusing portion 40B. The one-side reflecting surface 41A and the other-side reflecting surface 41B form a shape that is wide in the first direction.

[0033] The one-side reflecting surface 41A is curved so as to protrude toward the opposite side from the one-side generating unit 30A. The one-side reflecting surface 41A is curved so as to convert the longitudinal ultrasonic waves generated from the one-side generating unit 30A into shear waves and focus the converted shear waves toward the transmitting unit 50. The other-side reflecting surface 41B is curved so as to protrude toward the opposite side from the other-side generating unit 30B. The other-side reflecting surface 41B is curved so as to convert the longitudinal ultrasonic waves generated from the other-side generating unit 30B into shear waves and focus the converted shear waves toward the transmitting unit 50.

[0034] The transmission unit 50 connects the ultrasonic focusing unit 40 and the flow path configuration unit 20. The transmission unit 50 has a shape extending in the second direction. The transmission unit 50 has a shape that is wide in the first direction. The transmission unit 50 is disposed between the one-side focusing unit 40A and the other-side focusing unit 40B and connects the one-side focusing unit 40A and the other-side focusing unit 40B. The transmission unit 50 is thinner than the connection surface between the one-side focusing unit 40A and the other-side focusing unit 40B. The transmission unit 50 is formed, for example, from a metal (e.g., duralumin). The transmission unit 50 may be formed from the same material as the ultrasonic focusing unit 40, or may be formed from a different material. The transmission unit 50 vibrates upon receiving transverse ultrasonic waves focused toward itself, and generates longitudinal ultrasonic waves in the flow path 21, thereby focusing the particles 90 in the liquid L flowing through the flow path 21.

[0035] As indicated by the dashed-two-dot arrows in FIG. 2, the ultrasonic wave generating source 30 (specifically, the one-side generating unit 30A and the other-side generating unit 30B) generates longitudinal ultrasonic waves. These longitudinal waves are incident on the reflecting surface 41 (specifically, the one-side reflecting surface 41A and the other-side reflecting surface 41B). When the longitudinal waves generated by the ultrasonic wave generating source 30 are reflected by the reflecting surface 41, longitudinal waves and shear waves are generated. The dashed-two-dot arrows in FIG. 2 indicate the paths of the shear waves generated on the reflecting surface 41. The reflection angle θ2 of the shear wave generated on the reflecting surface 41 is smaller than the incident angle θ1 of the longitudinal wave incident on the reflecting surface 41. This relationship follows Snell's law. In other words, because the propagation velocity of the shear wave is smaller than the propagation velocity of the longitudinal wave, the reflection angle of the shear wave generated on the reflecting surface 41 is smaller than the incident angle of the longitudinal wave incident on the reflecting surface 41.

[0036] 3, the energy conversion rate from longitudinal waves to shear waves at reflecting surface 41 varies depending on the Poisson's ratio of the material constituting reflecting surface 41 and the angle of incidence of the longitudinal waves. Reflecting surface 41 includes reflection points where the energy conversion rate from longitudinal waves to shear waves is 50% or more. For example, at reflection points (e.g., reflection points 25A and 25B) where the Poisson's ratio of the material constituting reflecting surface 41 is 0.17 or more and 0.34 or less and the angle of incidence of the longitudinal waves is 40° or more and 85° or less, the energy conversion rate from longitudinal waves to shear waves is generally 50% or more.

[0037] The transverse ultrasonic waves generated at the reflecting surface 41 are focused on the transmitting section 50. This causes the transmitting section 50 to vibrate in the third direction, generating longitudinal ultrasonic waves toward the flow path 21. When the length X of the flow path 21 in the third direction is half the wavelength of the ultrasonic waves generated in the flow path 21, the wave shown by the dashed line in FIG. 4 is formed, and a node is formed in the center of the flow path 21 in the third direction. As a result, as shown in FIG. 5, the particles 90 in the flow path 21 are focused to the center in the third direction. The focused particles 90 are discharged from the separation flow path 70 provided in the particle focusing device 10.

[0038] Furthermore, when the length Y of the flow channel 21 in the second direction is half the wavelength of the ultrasonic waves generated in the flow channel 21, a wave shown by the dashed line in Fig. 6 is formed, and a node is formed in the center of the flow channel 21 in the second direction. As a result, the particles 90 in the flow channel 21 are focused at the center in the second direction. The length Y is shorter than the length X.

[0039] The control unit 60 adjusts the AC voltage applied by the power supply P to the ultrasonic wave generating source 30 so that ultrasonic waves of a desired wavelength are generated in the flow path 21. The control unit 60 may, for example, adjust the voltage so that half the wavelength of the ultrasonic waves generated in the flow path 21 is length X, or so that half the wavelength of the ultrasonic waves generated in the flow path 21 is length Y, or so that the half wavelength of the ultrasonic waves generated in the flow path 21 alternates between length X and length Y. The control unit 60 may also adjust the voltage so that the ultrasonic waves generated in the flow path 21 are superposed waves containing multiple frequency components.

[0040] In this way, the particle focusing device 10 can generate longitudinal ultrasonic waves in the transmitting part 50 by utilizing the transverse ultrasonic waves focused toward the transmitting part 50. Then, the particle focusing device 10 can focus the particles 90 in the liquid L flowing through the flow path 21 by the longitudinal ultrasonic waves generated from the transmitting part 50.

[0041] Furthermore, according to the particle focusing device 10, the ultrasonic waves generated on both sides in the second direction can be focused toward the transmitting part 50. Therefore, the transmitting part 50 can be vibrated more, the intensity of the ultrasonic waves generated in the flow channel 21 can be increased, and the focusing performance of the particles 90 can be improved.

[0042] Furthermore, the reflective surface 41 has a shape that follows an ellipse in a cross section cut in a direction perpendicular to the first direction, and the ratio of the major axis to the minor axis of the ellipse satisfies the condition of the following formula (1). Major axis: Minor axis = CDA: √(CDA 2 -CTA 2 )...Equation (1) CDA is the propagation velocity of the longitudinal wave incident on the reflecting surface 41. CTA is the propagation velocity of the shear wave generated at the reflecting surface 41. According to this configuration, the transverse waves generated at the reflecting surface 41 are focused at the focal point F.

[0043] The focal point F is located on the other side of the center C of the transmitting unit 50 in the third direction. The flow path configuring unit 20 is disposed on the other side of the transmitting unit 50 in the third direction. With this configuration, it is possible to focus the transverse ultrasonic waves at a position close to the flow path configuring unit 20, and to increase the vibration of the transmitting unit 50 at a position close to the flow path configuring unit 20. As a result, it is possible to increase the intensity of the ultrasonic waves generated in the flow path 21, and improve the focusing performance of the microparticles 90.

[0044] Furthermore, the flow path configuring unit 20 has a surface on one side in the third direction joined to the transmission unit 50. The flow path configuring unit 20 protrudes to the other side in the third direction. At least a portion of the flow path configuring unit 20 is arranged on the other side in the third direction of the ultrasonic generating source 30 and the ultrasonic focusing unit 40. The flow path configuring unit 20 is detachable from the transmission unit 50. Therefore, the flow path configuring unit 20 can be easily attached to and detached from the transmission unit 50.

[0045] Furthermore, the flow path configuration unit 20 is made of a transparent member and is exposed to the outside of the ultrasonic wave generating source 30 and the ultrasonic focusing unit 40. With this configuration, a user can view the flow path 21 from the outside of the flow path configuration unit 20 and visually check the focusing state of the microparticles 90 in the flow path 21. The transparent member may be transparent or translucent. Furthermore, at least a portion of the flow path 21 (the entire flow path 21 in the example shown in FIG. 2) is disposed on the other side of the ultrasonic wave generating source 30 and the ultrasonic focusing unit 40 in the third direction. Therefore, a user can easily view the flow path 21 from the second direction.

[0046] 2. Second embodiment In the first embodiment, the flow path forming section 20 was configured to be arranged on the other side of the transmitting section 50 in the third direction. In contrast, a particle focusing device 210 of the second embodiment shown in Fig. 7 is configured such that the flow path forming section 20 is arranged on one side of the transmitting section 50 in the third direction. The particle focusing device 210 is otherwise the same as the particle focusing device 10 of the first embodiment. Even with this configuration, it is possible to focus the particles 90 in the liquid L flowing through the flow path 21 by the longitudinal ultrasonic waves generated from the transmitting section 50.

[0047] 3. Third embodiment 8 corresponds to a configuration in which the other-side generating section 30B and the other-side focusing section 40B are removed from the particle focusing device 10 of the first embodiment. Specifically, the particle focusing device 310 includes a flow path configuration section 20, an ultrasonic wave generating source 330, an ultrasonic focusing section 340, a transmission section 50, a power source P, and a control section 60. The ultrasonic wave generating source 330 includes a one-side generating section 30A. The ultrasonic focusing section 340 includes a one-side focusing section 40A. Even with this configuration, it is possible to convert longitudinal ultrasonic waves generated from the ultrasonic wave generating source 330 into shear ultrasonic waves, and to focus the converted shear ultrasonic waves toward the transmission section 50.

[0048] 4. Fourth embodiment A particle focusing apparatus 410 of the fourth embodiment shown in FIG. 9 corresponds to a configuration in which a vibration absorber 80 is added to the particle focusing apparatus 310 of the third embodiment. The vibration absorber 80 is made of, for example, a cushioning material such as urethane or rubber, a bubble cushioning material, or a shock-absorbing gel. The vibration absorber 80 is bonded to the surface of the transmission unit 50 on the other side in the second direction. The vibration absorber 80 prevents the shear ultrasonic waves focused toward the transmission unit 50 from being reflected by the surface of the transmission unit 50 on the other side in the second direction. This makes it possible to prevent interference of reflected waves from adversely affecting the focusing of ultrasonic waves at the ultrasonic focusing unit 40. As a result, the focusing efficiency of ultrasonic waves can be improved.

[0049] 5. Fifth embodiment The particle focusing device 510 of the fifth embodiment shown in FIG. 10 corresponds to a configuration in which the other-side generation section 30B and the other-side focusing section 40B are removed from the particle focusing device 310 of the first embodiment, and the flow path configuration section 20 is arranged on the other side of the transmission section 550 in the second direction.

[0050] The particle focusing device 510 includes a flow path configuration unit 20, an ultrasonic wave generating source 530, an ultrasonic wave focusing unit 540, a transmission unit 550, a power source P, and a control unit 60. The ultrasonic wave generating source 530 has the one-side generating unit 30A described in the first embodiment. The ultrasonic wave focusing unit 540 has the one-side focusing unit 40A described in the first embodiment. The transmission unit 550 connects the one-side focusing unit 40A of the ultrasonic wave focusing unit 540 to the flow path configuration unit 20. The transmission unit 550 is disposed between the one-side focusing unit 40A and the flow path configuration unit 20. In other words, the one-side focusing unit 40A is disposed on one side of the transmission unit 550 in the second direction, and the flow path configuration unit 20 is disposed on the other side of the transmission unit 550 in the second direction. The flow path configuration unit 20 is oriented such that the length of the flow path 21 in the second direction is longer than the length in the third direction. A focal point F5 is set at the junction between the flow path forming unit 20 and the transmitting unit 550. According to this configuration, the ultrasonic transverse waves focused toward the transmitting unit 550 are propagated as transverse waves to the flow path 21. As a result, the liquid L in the flow path 21 vibrates in the third direction, and the particles 90 are focused at the center of the flow path 21 in the third direction.

[0051] <Other embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings, and the various features of the above-described and following embodiments may be combined in any compatible combination.

[0052] (1) In the first to fifth embodiments described above, the ultrasonic waves are focused toward the transmitting unit 50. However, strictly speaking, the configuration is not limited to the ultrasonic waves being focused at a focal point. For example, the shape of the reflecting surface may be adjusted so that the ultrasonic waves are transmitted almost evenly to the surface of the transmitting unit, or the ultrasonic waves may be stronger near the center of the surface of the transmitting surface.

[0053] (2) In the first to fifth embodiments, the ultrasonic wave generating source 30, the ultrasonic focusing unit 40, the transmitting unit 50, and the flow path 21 are configured to extend in the first direction, but they do not necessarily have to have the same shape in each cross section. For example, the ultrasonic wave generating source 30 may have a shape divided into multiple parts in the first direction, and the flow path 21 may have a different shape in part in the first direction.

[0054] It should be noted that the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, but is intended to include all modifications within the scope indicated by the claims or the scope equivalent to the claims. [Explanation of symbols]

[0055] 10…Particle focusing device 20...flow path configuration section 21...Flow path 25A…Reflection point 25B…Reflection point 30...Ultrasonic source 30A...One side generator 30B...Other side generating part 31...Piezoelectric body 32...Electrode 33...Electrode 40…Ultrasonic focusing section 40A...One-side focusing section 40B…Other side focusing section 41...Reflective surface 41A...One-side reflective surface 41B…Other side reflective surface 50...Transmission section 60...Control unit 70...Separation channel 80...Vibration absorber 90...Fine particles 210…Particle focusing device 310…Particle focusing device 330...Ultrasonic source 340…Ultrasonic focusing section 410…Particle focusing device 510…Particle focusing device 530...Ultrasonic source 540…Ultrasonic focusing section 550...Transmission section C…center F…Focus F5…Focus L…Liquid P…Power supply θ1…Incidence angle θ2…reflection angle

Claims

1. a flow path forming portion that forms a flow path through which a liquid flows; an ultrasonic wave generating source that generates ultrasonic waves, A particle focusing device that focuses particles in the liquid by applying ultrasonic waves to the liquid, an ultrasonic focusing unit having a reflecting surface that reflects the ultrasonic waves generated from the ultrasonic generation source; a transmission unit connecting the ultrasonic focusing unit and the flow path configuration unit; Equipped with The ultrasonic wave generating source generates longitudinal ultrasonic waves, The reflecting surface is curved so as to convert the longitudinal ultrasonic waves generated from the ultrasonic wave generation source into transverse ultrasonic waves and to focus the converted transverse ultrasonic waves toward the transmitting section, The ultrasonic wave is transmitted from the transmitting portion to the liquid. Particle focusing device.

2. The transmitting section vibrates upon receiving ultrasonic transverse waves focused toward itself, and generates ultrasonic longitudinal waves within the flow path, thereby focusing the particles in the liquid.

10. The particle focusing device of claim 1.

3. The reflecting surface has a shape along an ellipse in a cross section cut in a direction perpendicular to the direction in which the flow channel extends, and the ratio of the major axis to the minor axis of the ellipse satisfies the condition of the following formula (1):

3. The particle focusing device according to claim 1 or 2. Major axis : Minor axis = CDA : √(CDA) ２ -CTA ２ ) ・・・Form (1) CDA is the propagation velocity of the longitudinal wave incident on the reflecting surface. CTA is the propagation speed of the transverse wave generated at the reflecting surface.

4. The ultrasonic wave generating source a one-side generation unit disposed on one side of the flow path in a second direction perpendicular to a first direction in which the flow path extends; a second-side generating portion disposed on the other side of the flow path in the second direction, The ultrasonic focusing unit a one-side converging portion disposed on one side of the flow path in the second direction; an other-side converging portion disposed on the other side of the flow path in the second direction, the reflecting surface includes a one-side reflecting surface provided on the one-side focusing portion and a second-side reflecting surface provided on the second-side focusing portion, the transmission section is disposed between the one-side focusing section and the other-side focusing section, and is configured to connect the one-side focusing section and the other-side focusing section; the one-side generating unit and the other-side generating unit each generate longitudinal ultrasonic waves, the one-side reflecting surface is curved so as to convert the longitudinal ultrasonic waves generated from the one-side generating unit into shear waves and to focus the converted shear waves toward the transmitting unit, The other-side reflecting surface is curved so as to convert the longitudinal ultrasonic waves generated from the other-side generating portion into shear waves and to focus the converted shear waves toward the transmitting portion.

3. The particle focusing device of claim 2.

5. In a second direction perpendicular to a first direction in which the flow path extends, the ultrasonic wave generating source and the ultrasonic focusing unit are disposed on opposite sides of the flow path configuring unit with the transmission unit interposed therebetween, The reflecting surface converts the longitudinal ultrasonic waves generated from the ultrasonic wave generation source into shear waves and focuses the converted shear waves at a focal point located closer to the flow path configuration unit than the center of the transmitting unit in the orthogonal direction.

10. The particle focusing device of claim 1.

6. the ultrasonic wave generating source generates ultrasonic waves toward one side in a third direction perpendicular to a first direction in which the flow path extends, the reflecting surface reflects the longitudinal ultrasonic waves generated from the ultrasonic wave generation source and converts them into shear waves, and focuses the converted shear waves at a focal point located on the other side of the center of the transmitting section in the third direction, The flow path configuration portion is disposed on the other side of the transmission portion in the third direction.

3. The particle focusing device of claim 2.

7. The flow path forming portion is made of a permeable material.

3. The particle focusing device according to claim 1 or 2.

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