Fluid device and method for controlling fluid device

Abstract

To provide: a fluid device capable of stably capturing fine particles having a desired size; and a method for controlling the fluid device.SOLUTION: A fluid device 10 includes: a flow path 20 through which a fluid containing fine particles flows; an ultrasonic transmitter 60 configured to transmit an ultrasonic wave to the fluid in the flow path 20 in response to an input of a drive signal; a flow velocity measurement unit 40 configured to measure a flow velocity of the fluid in the flow path 20; and a controller 70 configured to control the ultrasonic transmitter 60. The controller 70 sets an amplitude of the drive signal according to a measured flow velocity that is a flow velocity measured by the flow velocity measurement unit 40, and inputs the drive signal having the set amplitude to the ultrasonic transmitter 60.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fluidic device and a method for controlling a fluidic device. [Background technology]

[0002] Conventionally, devices that separate fine particles dispersed in a fluid from the fluid are known. For example, a fluid device disclosed in Patent Document 1 includes a substrate on which a flow path is formed, and a piezoelectric element provided on the substrate. Ultrasonic waves generated by the piezoelectric element are transmitted into the flow path through the substrate, and generate standing waves in the fluid in the flow path. The fine particles in the fluid are focused in a predetermined range in the flow path due to the pressure gradient of the fluid formed by the standing waves, and a concentrated liquid containing the focused fine particles is collected. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2005 / 058459 Summary of the Invention [Problem to be solved by the invention]

[0004] In a fluidic device such as that described in Patent Document 1, it is desirable to adjust the size of particles that can be captured. However, when the output of the fluidic device (i.e., the amplitude of the ultrasonic waves) is adjusted so that particles of a desired size can be captured, there is a problem that the size of the particles that can be captured changes due to a change in the flow rate of the fluid. As a result, it is difficult to stably capture particles of a desired size. [Means for solving the problem]

[0005] A fluidic device according to a first aspect of the present disclosure comprises a flow path through which a fluid containing microparticles flows, an ultrasonic transmitting unit that transmits ultrasonic waves to the fluid in the flow path upon input of a drive signal, a flow rate measuring unit that measures the flow rate of the fluid in the flow path, and a control unit that controls the ultrasonic transmitting unit, wherein the control unit sets the amplitude of the drive signal in accordance with a measured flow rate, which is the flow rate measured by the flow rate measuring unit, and inputs the drive signal of the set amplitude to the ultrasonic transmitting unit.

[0006] A control method for a fluidic device according to a second aspect of the present disclosure is a control method for a fluidic device comprising a flow path through which a fluid containing fine particles flows, an ultrasonic transmitting unit that transmits ultrasonic waves to the fluid in the flow path upon input of a drive signal, and a flow rate measuring unit that measures the flow rate of the fluid in the flow path, wherein the amplitude of the drive signal is set according to a measured flow rate, which is the flow rate measured by the flow rate measuring unit, and the drive signal of the set amplitude is input to the ultrasonic transmitting unit. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing a fluidic device according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view that illustrates a separation module in the fluidic device of the first embodiment. [Diagram 3] 4 is a flowchart illustrating a control method of the fluidic device of the first embodiment. [Figure 4] FIG. 4 is a schematic diagram showing a fluidic device according to a second embodiment. [Diagram 5] FIG. 13 is a diagram showing a flow path system in a fluidic device according to a modified example. [Figure 6] FIG. 13 is a diagram showing a flow path system in a fluidic device according to another modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [First embodiment] A fluidic device according to a first embodiment will be described with reference to FIGS. (Configuration of Fluid Device) As shown in Figures 1 and 2, the fluidic device 10 of this embodiment comprises a flow path 20 through which a fluid S containing fine particles M flows, a pump 30 that generates a flow of the fluid S within the flow path 20, a flow rate measuring unit 40 that measures the flow rate of the fluid S in the flow path 20, a separation module 50 that includes a part of the flow path 20, a control unit 70 that controls the operation of the fluidic device 10, and a housing 80 that accommodates these.

[0009] The fluidic device 10 of this embodiment uses ultrasound to capture particles M in the fluid S in the flow path 20 in the separation module 50, thereby making it possible to recover the fluid S in which the particles M are concentrated. Furthermore, the fluidic device 10 of this embodiment measures the flow rate of the fluid S flowing through the flow path 20, and sets or adjusts the output of the fluidic device 10 (i.e., the amplitude of the ultrasound) based on the measurement result. In this embodiment, the fluid S is any liquid, such as water or blood, but is not limited thereto. The particles M are, but are not limited thereto, microfibers or cells, for example. In FIG. 2, for the sake of simplicity, the size of the multiple particles M is the same, but it is assumed that particles M of various sizes are dispersed in the fluid S.

[0010] 1, the flow path 20 has an inlet 21 through which the fluid S flows, a communication flow path 22 that communicates between the inlet 21 and the separation module 50, a separation flow path 23 included in the separation module 50, a concentrated outlet 24 that discharges the fluid S containing the particles M captured by the separation module 50 (i.e., a concentrated liquid), and a discharge port 25 that discharges the fluid S other than the concentrated liquid from the separation module 50. The concentrated outlet 24 and the discharge port 25 correspond to the discharge ports of the present invention.

[0011] The pump 30 may be any device capable of generating a flow of the fluid S in the flow passage 20, such as a peristaltic pump or a diaphragm pump. In this embodiment, the pump 30 is provided at any position in the communication passage 22.

[0012] The flow rate measurement unit 40 may be any device that measures the flow rate of the fluid S in the flow path 20, such as an ultrasonic flowmeter. In this embodiment, the flow rate measurement unit 40 is provided in the communication flow path 22 at a position downstream of the pump 30. However, the flow rate measurement unit 40 may be provided at a position upstream of the pump 30.

[0013] As shown in FIG. 2, the separation module 50 has a separation channel which is a part of the channel 20, and an ultrasonic transmitter 60 which transmits ultrasonic waves to the fluid S in the separation channel .

[0014] The separation flow path 23 is formed in, for example, a flow path substrate 51. The flow path substrate 51 is composed of a base substrate having a groove corresponding to the separation flow path 23, and a lid substrate covering the groove. These substrates are not particularly limited, and may be, for example, a glass substrate or a silicon substrate. The separation flow path 23 has an inflow flow path 231 into which the fluid S flows from the communication flow path 22, a flow path main body 232 in which a standing wave is formed, a concentration flow path 233 that selectively circulates the fluid S containing the particles captured by the standing wave, and a discharge flow path 234 that selectively circulates the other fluids S. The flow path main body 232 has a first wall surface 235 and a second wall surface 236 that face each other in an arbitrary flow path width direction (Y direction) perpendicular to the flow direction (X direction) of the fluid S. The flow path width L between the first wall surface 235 and the second wall surface 236 is a known value. The above-mentioned concentration outlet 24 is connected to the concentration flow path 233, and the above-mentioned outlet 25 is connected to the discharge flow path 234.

[0015] The ultrasonic transmitting unit 60 has an ultrasonic transmitting surface 60A that constitutes part of the first wall surface 235, and the ultrasonic transmitting surface 60A faces the fluid S in the flow path main body 232, thereby being able to transmit ultrasonic waves to the fluid S. Specifically, the ultrasonic transmission unit 60 includes an element substrate 61, a vibration membrane 62 supported by the element substrate 61, and a piezoelectric element 63 provided on the vibration membrane 62. The element substrate 61 is made of a semiconductor substrate such as Si, and an opening 611 is provided through the element substrate 61 in the thickness direction. The vibration membrane 62 is made of a laminated body of a plurality of types of films, such as a SiO2 film and a ZrO2 film, and is supported by the element substrate 61 and closes the opening 611. An acoustic matching layer may be provided in the opening 611. A portion of the vibration membrane 62 that overlaps with the opening 611 in a plan view in the thickness direction of the element substrate 61 constitutes a vibration unit 621 that transmits ultrasonic waves. The piezoelectric element 63 is provided at a position overlapping with the vibration unit 621. Although not shown, the piezoelectric element 63 is configured by sequentially stacking a lower electrode, a piezoelectric film, and an upper electrode on the vibration membrane 62.

[0016] In such an ultrasonic transmission unit 60, when a drive signal Sd is input from a drive circuit 71 described later to the piezoelectric element 63, the piezoelectric film of the piezoelectric element 63 expands and contracts, causing the vibration unit 621 to flex and vibrate in the thickness direction of the element substrate 61. The flexural vibration of the vibration unit 621 is converted into compression waves of the fluid S, and ultrasonic waves are propagated from the ultrasonic transmission unit 60 to the fluid S. Here, since the thickness direction of the element substrate 61 is the direction along the flow channel width direction (Y direction) of the flow channel main body 232, ultrasonic waves are transmitted in the flow channel width direction (Y direction).

[0017] As shown in FIG. 1, the control unit 70 includes a drive circuit 71 that drives the ultrasonic transmission unit 60, a processor 72 that performs various controls, and a memory 73.

[0018] The drive circuit 71 outputs a drive signal Sd of a predetermined frequency to the ultrasonic transmission unit 60. The amplitude of the drive signal Sd (i.e., drive voltage Vd) corresponds to the amplitude of the ultrasonic waves transmitted from the ultrasonic transmission unit 60.

[0019] The processor 72 executes a program stored in the memory 73 to function as a measurement control unit 721 and a drive control unit 722. Details of the measurement control unit 721 and the drive control unit 722 will be described later. The memory 73 is a storage device that stores various programs and various data. For example, the memory 73 stores a drive table or calculation coefficients that indicate the correspondence between the measured flow velocity V and the drive voltage Vd. It is preferable that the drive table or calculation coefficients are prepared for each size of the particles M to be captured. The size of the particles M may be divided into any numerical ranges, such as the dimensions or volume of the particles M.

[0020] The housing 80 houses the flow path 20, the flow rate measuring unit 40, the separation module 50 and the control unit 70. This allows the fluidic device 10 to be integrally configured. The inlet 21, the concentrated outlet 24 and the outlet 25 of the flow path 20 are provided in the housing 80. A battery that supplies power to each part of the fluidic device 10 may also be housed in the housing 80. Although not particularly limited, it is preferable to miniaturize the fluidic device 10 by housing each part in a housing 80 of 100 cc or less.

[0021] (Control mechanism of fluidic devices) The mechanism by which the particles M in the fluid S are concentrated in the fluidic device 10 of this embodiment will be described. The ultrasonic waves transmitted from the ultrasonic transmitting unit 60 are diffused radially into the fluid S as spherical waves, and among these, the ultrasonic waves traveling along the flow path width direction (Y direction) are repeatedly reflected between the first wall surface 235 and the second wall surface 236, thereby generating a standing wave SW within the flow path body 232. Here, when the frequency of the ultrasound transmitted from the ultrasound transmitting unit 60 is f, the mode order of the standing wave SW is m, the speed of sound in the fluid S is c, and the flow path width of the flow path 20 is L, the standing wave SW is formed when the condition of the following equation (1) is satisfied.

number

[0022] As shown in Fig. 2, when a standing wave SW of the first mode occurs, a node appears in the center of the flow path width direction (Y direction) of the flow path main body 232, and antinodes appear at both ends of the flow path width direction of the flow path main body 232. In this case, the particles M having a higher acoustic impedance than the fluid S are focused (acoustic focusing) at the node of the standing wave SW, that is, at the center of the flow path width direction of the flow path main body 232, during the process in which the fluid S flows through the flow path main body 232. Then, the fluid S (concentrated liquid) containing the focused particles M is discharged from the concentrated outlet 24 via the concentrated flow path 233, and the rest of the fluid S is discharged from the discharge port 25 via the discharge flow path 234. That is, the particles M are separated from the fluid S as a concentrated liquid. In this embodiment, for the sake of simplicity, an example is used in which a standing wave SW of a first mode is generated, but the mode order of the standing wave SW is not particularly limited.

[0023] Here, the trapping force of the fluidic device 10 on the particles M determines the lower limit of the size of the particles that can be trapped by acoustic focusing, and the greater the trapping force, the smaller the particles that can be trapped. The force of the fluid device 10 to capture the particles M depends on the amplitude of the ultrasonic waves (i.e., the driving voltage Vd) and the flow velocity of the fluid S. If the driving voltage Vd is adjusted at a predetermined flow velocity so that particles M of a desired size can be captured, when the flow velocity changes due to output fluctuations of the pump 30 or the like, the size range of the particles M that can be captured changes. For example, when the flow velocity is fast, the fluid S passes through the range where the standing wave SW is formed before the particles M of the desired size are sufficiently focused, and the particles M of the desired size cannot be sufficiently captured. On the other hand, when the flow velocity is slow, not only the particles M of the desired size but also smaller particles M are focused while the fluid S passes through the range where the standing wave SW is formed, and the accuracy of the size of the particles M that can be captured decreases. Therefore, in this embodiment, the flow velocity of the fluid S is measured as described below, and the driving voltage Vd is adjusted according to the measured flow velocity (measured flow velocity V), thereby making it possible to stably capture particles M of a desired size.

[0024] (Method of controlling a fluid device) An example of a control method for the fluidic device 10 of this embodiment will be described with reference to the flowchart of Fig. 3. Note that, before the start of the flowchart, the size of the particles M to be captured may be set to a predetermined size in advance, or may be set according to the operation of the user. In addition, in this embodiment, for the sake of simplicity of explanation, it is assumed that the predetermined frequency f for forming the standing wave SW is determined in advance.

[0025] First, the pump 30 starts in response to a start operation by the user (step S1). At this time, the output of the pump 30 may be set in response to the operation by the user, or may be set to a predetermined output in advance.

[0026] After a predetermined time has elapsed since the start of the pump 30, the measurement control unit 721 outputs a measurement instruction to the flow rate measurement unit 40 and acquires the flow rate of the fluid S measured by the flow rate measurement unit 40 (i.e., the measured flow rate V) (step S2). Note that the predetermined time is, for example, the time required for the operation of the pump 30 to stabilize. In addition, the value of the measured flow rate V measured in step S2 is stored in the memory 73 as a reference flow rate Vs.

[0027] Next, the drive control unit 722 sets the drive voltage Vd in accordance with the measured flow velocity V measured in step S2 (step S3), thereby setting the amplitude of the ultrasonic waves transmitted from the ultrasonic transmission unit 60. For example, the drive control unit 722 identifies from the memory 73 a drive table or calculation coefficient corresponding to the size of the particle M to be captured, calculates the value of the drive voltage Vd corresponding to the measured flow velocity V measured in step S2 based on the identified drive table or calculation coefficient, and sets the calculated value in the drive circuit 71.

[0028] Thereafter, the driving circuit 71 starts outputting a driving signal Sd having a predetermined frequency f for forming the standing wave SW and the driving voltage Vd set in step S3 to the ultrasonic transmission unit 60 (step S4). As a result, ultrasonic waves are transmitted from the ultrasonic transmission unit 60, and a standing wave is formed in the fluid S, so that separation of a concentrated solution of the microparticles M starts.

[0029] Then, the measurement control unit 721 judges whether or not a predetermined measurement timing has arrived (step S5), and when it judges that the measurement timing has arrived (step S5; Yes), it outputs a measurement command to the flow velocity measurement unit 40 and acquires the measured flow velocity V measured by the flow velocity measurement unit 40 (step S6). This measurement timing is not particularly limited, but may be set, for example, at predetermined time intervals.

[0030] Next, the drive control unit 722 determines whether or not the measured flow velocity V measured in step S6 matches the reference flow velocity Vs stored in the memory 73 (step S7). Here, "match" is not limited to a perfect match, but includes a predetermined error. In other words, if |V-Vs| is within a preset error range, it is determined that the two match.

[0031] If the result of step S7 is No, the drive control unit 722 adjusts the drive voltage Vd in accordance with the measured flow velocity V measured in step S5 (step S8). Specifically, the drive control unit 722 identifies a drive table or a calculation coefficient corresponding to the size of the particle M to be captured from the memory 73, calculates a value of the drive voltage Vd corresponding to the measured flow velocity V measured in step S6 based on the identified drive table or calculation coefficient, and sets the calculated value in the drive circuit 71. In addition, the drive control unit 722 updates the value of the measured flow velocity V measured in step S6 as the reference flow velocity Vs stored in the memory 73.

[0032] If the measured flow velocity V is greater than the reference flow velocity Vs, the drive control unit 722 calculates a value greater than the current set value as the drive voltage Vd, and increases the drive voltage Vd set in the drive circuit 71. This increases the speed at which the particles M in the fluid S converge, so that the particles M of a desired size can be sufficiently converged while the fluid S passes through the range in which the standing wave SW is formed. On the other hand, when the measured flow velocity V is smaller than the reference flow velocity Vs, the drive control unit 722 calculates a value smaller than the current set value as the drive voltage Vd, and reduces the drive voltage Vd set in the drive circuit 71. This slows down the speed at which the particles M in the fluid S converge, so that while the fluid S passes through the range in which the standing wave SW is formed, it is possible to converge particles M of a desired size while preventing particles M smaller than the desired size from being converged.

[0033] If the result of the determination in step S7 is Yes, the ultrasonic transmission unit 60 continues to be driven by the current drive voltage Vd, and the process proceeds to step S9.

[0034] Thereafter, the control unit 70 determines whether or not to stop the separation of the concentrated liquid (step S9). For example, when a stop command is input by the user or when a predetermined time has elapsed, the control unit 70 determines Yes in step S9 and stops the operations of the pump 30 and the ultrasonic transmission unit 60 (step S10). On the other hand, when the control unit 70 determines No in step S9, the process returns to step S5. Thus, while the flow chart of FIG. 3 continues, the drive voltage Vd is controlled in response to the measured flow velocity V.

[0035] (Effects of this embodiment) As described above, the fluidic device 10 of this embodiment can focus the particles M in the fluid S by the acoustic force of the ultrasonic waves transmitted from the ultrasonic transmission unit 60. In addition, the amplitude of the ultrasonic waves can be appropriately set by adjusting the amplitude of the drive signal Sd according to the measured flow velocity V. As a result, the particles M of a desired size can be stably captured.

[0036] In this embodiment, the control unit 70 increases the amplitude of the drive signal Sd when the measured flow velocity V is greater than the reference flow velocity Vs, and decreases the amplitude of the drive signal Sd when the measured flow velocity V is smaller than the reference flow velocity Vs. This makes it possible to more stably capture particles M of a desired size.

[0037] In this embodiment, the control unit 70 adjusts the amplitude of the drive signal Sd based on the set size of the particles M and the measured flow velocity V. This makes it possible to more suitably collect particles M of a desired size.

[0038] In this embodiment, the flow rate measurement unit 40 measures the flow rate of the fluid S between the separation module 50 and the pump 30 in the flow path 20. In this configuration, the pump 30, the flow rate measurement unit 40, and the separation module 50 can be configured as separate entities, making it easy to install and maintain each component.

[0039] The ultrasonic transmission unit 60 of the present embodiment includes a vibration unit 621 provided in the flow path 20, and can efficiently transmit ultrasonic waves from the ultrasonic transmission unit 60 to the fluid S. This can reduce power consumption.

[0040] In this embodiment, the ultrasonic transmitter 60 transmits ultrasonic waves to the fluid S, thereby generating a standing wave SW in the fluid S along a direction perpendicular to the flow direction of the fluid S. This makes it possible to focus the particles M in the fluid S on the nodes (or antinodes) of the standing wave SW, and thus makes it possible to suitably collect the particles M.

[0041] In this embodiment, the fluid device 10 further includes a housing 80 that houses the flow rate measurement unit 40, the ultrasonic transmission unit 60, and the control unit 70, and the housing 80 is provided with the inlet 21, the concentrated outlet 24, and the outlet 25 of the flow path 20. In this configuration, the fluid device 10 is integrally constructed, and the portability of the fluid device 10 can be improved.

[0042] [Second embodiment] A fluidic device according to the second embodiment will be described with reference to FIG. The fluidic device 10A of the second embodiment has substantially the same configuration as the first embodiment, except that it further includes a configuration for inspecting particles M. In the following, the same configurations as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted or simplified.

[0043] The fluidic device 10A of the second embodiment includes an inspection module 90 instead of the concentrated outlet 24 of the flow path 20 of the first embodiment. The inspection module 90 is connected to the concentrated flow path 233 in the separation module 50, collects the fluid S (concentrated liquid) containing the focused particles M, and obtains various information about the particles M in the collected concentrated liquid. Moreover, the processor 72 of the second embodiment also functions as an inspection control unit 723 that controls the inspection module 90 by executing a program stored in the memory 73. This inspection control unit 723 performs analysis of the particles M based on information acquired by the inspection module 90. The inspection control unit 723 may display the analysis results on the display unit 81, or may transmit the analysis results to an external terminal via wired or wireless communication.

[0044] The types of inspection and analysis performed by the inspection module 90 and the inspection control unit 723 are not particularly limited. For example, the inspection module 90 and the inspection control unit 723 may be configured as a spectrophotometer such as a cell counter that measures the concentration of the particles M. The inspection module 90 may also include an imaging means, and the inspection control unit 723 may analyze the particles M based on the captured image. Alternatively, the inspection module 90 may include a laser light source and a spectroscope, and the inspection control unit 723 may analyze the particles M by various spectroscopy methods such as absorptiometry and Raman spectroscopy.

[0045] The control method of the fluidic device 10A of the second embodiment is similar to that of the first embodiment, except that the determination in step S9 of FIG.

[0046] In addition to the effects of the first embodiment, the fluidic device 10A of the second embodiment described above can suitably test the collected particles M. In particular, the fluidic device 10A of the second embodiment can be suitably used for testing particles M of a specific size in a fluid S containing particles M of various sizes.

[0047] [Variations] The present invention is not limited to the above-described embodiments, and the present invention includes configurations obtained by modifying, improving, and appropriately combining the embodiments within the scope that can achieve the object of the present invention.

[0048] (Variation 1) In each of the above embodiments, an example is shown in which the flow rate measurement unit 40 is configured to measure the flow rate of the fluid S between the separation module 50 and the pump 30, but the arrangement of the flow rate measurement unit 40 is not limited to this.

[0049] Fig. 5 is a flow path diagram showing the arrangement of a flow rate measurement unit 40 according to a modified example. As shown in Fig. 5, the flow rate measurement unit 40 may measure the flow rate of the fluid S in the separation module 50. In this case, the flow rate measurement unit 40 can be configured integrally with the separation module 50. In this modified example, by measuring the flow rate of the fluid S in the separation module 50, the amplitude of the drive signal Sd can be adjusted with higher accuracy.

[0050] 6 is a flow path diagram showing the arrangement of the flow rate measurement unit 40 according to another modified example. As shown in FIG. 6, the flow rate measurement unit 40 may measure the flow rate of the fluid S in the pump 30. In this case, the flow rate measurement unit 40 can be configured integrally with the pump 30. In such a modified example, a commercially available pump with an integrated flow meter can be used as the pump 30 and the flow rate measurement unit 40.

[0051] In each of the above embodiments, for the sake of simplicity, the flow velocity measurement unit 40 is described as outputting the flow velocity, but the flow velocity measurement unit 40 may be a sensor that at least detects the flow velocity. In this case, the measurement control unit 721 may perform a calculation process to calculate the flow velocity based on the detection signal input from the flow velocity measurement unit 40.

[0052] (Variation 2) In each of the above-described embodiments, in the control method for the fluidic device 10, 10A (see FIG. 3), the flow velocity measurement unit 40 measures the flow velocity (step S2) to initially set the reference flow velocity Vs, but this is not limiting. For example, the initial value of the reference flow velocity Vs may be set in advance based on the output of the pump 30, etc. In this case, the drive voltage Vd may be set in advance.

[0053] (Variation 3) In each of the above embodiments, the control method for the fluid device 10, 10A (see FIG. 3) involves repeatedly measuring the flow rate (step S6) after the start of separation of the concentrated liquid, and adjusting the driving voltage Vd according to the measured flow rate V, but this is not limited to this. For example, after the initial setting of the driving voltage Vd in accordance with the first measured flow velocity V (step S3), it is not necessary to adjust the driving voltage Vd in accordance with the measured flow velocity V (steps S6 to S8).

[0054] (Variation 4) Although the fluidic devices 10, 10A of the above embodiments include a pump 30 that generates a flow of the fluid S, such a pump 30 may not be included. For example, the pump 30 may be disposed outside the housing 80 and provided as a separate body from the fluidic devices 10, 10A. Alternatively, when the fluid S supplied to the fluidic devices 10, 10A has a flow, the pump 30 may not be provided.

[0055] (Variation 5) Although the fluidic device 10, 10A in each of the above-described embodiments includes a housing 80 for housing each component, such a housing 80 may not be included.

[0056] (Variation 6) In the separation module 50 of each of the above-described embodiments, the separation channel 23 that is a part of the channel 20 is formed, but this is not limiting, and the entire channel 20 may be formed in the separation module 50 .

[0057] (Variation 7) In the fluidic devices 10 and 10A of the above-described embodiments, the configuration of the ultrasonic transmission section 60 is not limited to that described above. For example, the ultrasonic transmission unit 60 may have a plurality of vibration units 621. In this case, a plurality of openings 611 may be provided in an array on the element substrate 61, and a portion of the vibration membrane 62 provided on the element substrate 61 that overlaps with each opening 611 may constitute the vibration unit 621. A piezoelectric element 63 is provided for each vibration unit 621, so that ultrasonic waves are transmitted from each vibration unit 621. The ultrasonic transmission unit 60 may have a configuration for vibrating a piezoelectric actuator, or may have a configuration for vibrating a vibration plate included in an electrostatic actuator. Such an ultrasonic element can transmit ultrasonic waves by generating vibrations when a drive signal Sd of a predetermined drive frequency is applied.

[0058] (Variation 8) In each of the above embodiments, the standing wave SW is generated in the width direction of the flow channel 20, which is a direction perpendicular to the flow direction of the fluid S. However, the standing wave SW may be generated in the depth direction of the flow channel 20. Furthermore, the fluidic devices 10 and 10A of the above embodiments are not limited to forming a standing wave SW in the flow path. For example, the fluidic devices 10 and 10A may be any devices that use the acoustic force of ultrasonic waves to manipulate particles M of a desired size.

[0059] [Summary of this disclosure] The following is a summary of this disclosure. (Appendix 1) The fluidic device according to the present disclosure comprises a flow path through which a fluid containing fine particles flows, an ultrasonic transmitting unit that transmits ultrasonic waves to the fluid in the flow path upon input of a drive signal, a flow rate measuring unit that measures the flow rate of the fluid in the flow path, and a control unit that controls the ultrasonic transmitting unit, wherein the control unit sets the amplitude of the drive signal in accordance with a measured flow rate, which is the flow rate measured by the flow rate measuring unit, and inputs the drive signal of the set amplitude to the ultrasonic transmitting unit. In this configuration, the acoustic force of the ultrasonic waves transmitted from the ultrasonic transmitter can be used to manipulate and collect particles in the fluid. In addition, the amplitude of the drive signal can be adjusted according to the measured flow velocity, thereby adjusting the amplitude of the ultrasonic waves and stabilizing the size of the collected particles.

[0060] (Appendix 2) In the fluidic device described in Supplementary Note 1, it is preferable that the control unit increases the amplitude of the drive signal when the measured flow velocity is greater than a reference flow velocity while the ultrasonic transmission unit transmits ultrasonic waves to the fluid, and decreases the amplitude of the drive signal when the measured flow velocity is less than the reference flow velocity. This makes it possible to stably collect fine particles of a desired size.

[0061] (Appendix 3) In the fluidic device according to Supplementary Note 1 or 2, it is preferable that the control unit sets the amplitude of the drive signal based on the size of the microparticle and the measured flow velocity, thereby making it possible to more suitably collect microparticles of a desired size.

[0062] (Appendix 4) The fluidic device according to any one of Supplementary Note 1 to Supplementary Note 3 may further include a separation module including the ultrasonic transmission unit and a part of the flow path, and a pump that generates a flow of the fluid in the flow path, and the flow rate measurement unit may measure the flow rate of the fluid in the flow path between the separation module and the pump. In such a configuration, the pump, the flow rate measurement unit, and the separation module can be configured as separate entities, making it easy to install and maintain each component.

[0063] (Appendix 5) The fluidic device according to any one of Supplementary Note 1 to Supplementary Note 3 may further include a separation module including the ultrasonic transmission unit and at least a part of the flow path, and the flow rate measurement unit may measure the flow rate of the fluid in the separation module. In such a configuration, the amplitude of the drive signal for manipulating particles of a desired size can be set more accurately.

[0064] (Appendix 6) The fluidic device according to any one of Supplementary Note 1 to Supplementary Note 3 may further include a pump that generates a flow of the fluid in the flow path, and the flow rate measuring unit may measure the flow rate of the fluid in the pump. In such a configuration, a commercially available pump with an integrated flow meter can be suitably used.

[0065] (Appendix 7) In the fluidic device according to any one of Supplementary Note 1 to Supplementary Note 6, it is preferable that the ultrasonic transmission unit has a vibration unit provided in the flow path, and a piezoelectric element provided in the vibration unit and transmitting the ultrasonic waves to the fluid by flexurally vibrating the vibration unit. This improves the efficiency of ultrasonic wave propagation from the ultrasonic transmission unit to the fluid, and reduces power consumption.

[0066] (Appendix 8) In the fluidic device according to any one of Supplementary Note 1 to Supplementary Note 7, it is preferable that the ultrasonic transmitter transmits ultrasonic waves to the fluid to generate a standing wave in the fluid along a direction perpendicular to the flow direction of the fluid, thereby making it possible to focus particles in the fluid on nodes (or antinodes) of the standing wave, and to more suitably collect the particles.

[0067] (Appendix 9) The fluidic device according to any one of Supplementary Note 1 to Supplementary Note 8 further includes a housing that houses the flow rate measuring unit, the ultrasonic transmission unit, and the control unit, and the housing is preferably provided with an inlet through which the fluid flows into the flow path, and one or more outlets through which the fluid flows out of the flow path. In this configuration, the fluidic device is integrally constructed, and the portability of the fluidic device can be improved.

[0068] (Appendix 10) The fluidic device according to any one of Supplementary Note 1 to Supplementary Note 6 may further include an inspection module that collects the particles focused by the ultrasonic waves and inspects the collected particles.

[0069] (Appendix 11) The control method of the fluidic device according to the present disclosure is a control method of a fluidic device including a flow path through which a fluid containing fine particles flows, an ultrasonic transmitter that transmits ultrasonic waves to the fluid in the flow path by inputting a drive signal, and a flow velocity measuring unit that measures the flow velocity of the fluid in the flow path, and the amplitude of the drive signal is set according to a measured flow velocity, which is the flow velocity measured by the flow velocity measuring unit, and the drive signal of the set amplitude is input to the ultrasonic transmitter. According to this method, the size of the collected fine particles can be stabilized. [Explanation of symbols]

[0070] 10, 10A... fluid device, 20... flow path, 21... inlet, 22... communication flow path, 23... separation flow path, 231... inlet flow path, 232... flow path main body, 233... concentration flow path, 234... discharge flow path, 235... first wall surface, 236... second wall surface, 24... concentration outlet, 25... discharge port, 30... pump, 40... flow rate measurement unit, 50... separation module, 60... ultrasonic transmission unit, 60A... ultrasonic transmission surface, 61... element substrate Plate, 611...opening, 62...vibrating membrane, 621...vibrating part, 63...piezoelectric element, 70...control part, 71...drive circuit, 72...processor, 721...measurement control part, 722...drive control part, 723...inspection control part, 73...memory, 80...housing, 81...display part, 90...inspection module, f...predetermined frequency, L...flow path width, M...particle, S...fluid, Sd...drive signal, SW...standing wave, V...measured flow velocity.

Claims

1. A flow path through which a fluid containing fine particles flows, an ultrasonic transmitter that transmits ultrasonic waves to the fluid in the flow path by inputting a drive signal, a flow velocity measurement unit that measures the flow velocity of the fluid in the flow path, and a control unit that controls the ultrasonic transmitter, wherein the control unit sets the amplitude of the drive signal according to the measured flow velocity measured by the flow velocity measurement unit, and inputs the drive signal with the set amplitude to the ultrasonic transmitter. A fluid device.

2. While the ultrasonic transmitter transmits the ultrasonic waves to the fluid, when the measured flow velocity is greater than a reference flow velocity, the control unit increases the amplitude of the drive signal, and when the measured flow velocity is less than the reference flow velocity, the control unit decreases the amplitude of the drive signal. The fluid device according to claim 1.

3. The control unit sets the amplitude of the drive signal based on the size of the fine particles to be captured and the measured flow velocity. The fluid device according to claim 1.

4. a separation module including at least a part of the flow path and provided with the ultrasonic transmitter, and a pump that generates a flow of the fluid in the flow path, wherein the flow velocity measurement unit measures the flow velocity of the fluid between the separation module and the pump in the flow path. The fluid device according to claim 1.

5. further comprising a separation module including at least a part of the flow path and provided with the ultrasonic transmitter, wherein the flow velocity measurement unit measures the flow velocity of the fluid in the separation module. The fluid device according to claim 1.

6. further comprising a pump that generates a flow of the fluid in the flow path, wherein the flow velocity measurement unit measures the flow velocity of the fluid in the pump. The fluid device according to claim 1.

7. The ultrasonic transmitter has a vibration part provided in the flow path, and a piezoelectric element provided on the vibration part that transmits the ultrasonic waves to the fluid by flexurally vibrating the vibration part. The fluid device according to claim 1.

8. The ultrasonic transmitter generates a standing wave in the fluid along a direction orthogonal to the flow direction of the fluid by transmitting the ultrasonic waves to the fluid. The fluid device according to claim 1.

9. further comprising a housing that houses the flow velocity measurement unit, the ultrasonic transmitter, and the control unit, The fluid device according to claim 1, wherein the housing is provided with an inlet through which the fluid flows into the flow path and one or more outlets through which the fluid flows out of the flow path.

10. The fluid device according to claim 1, further comprising an inspection module that collects the microparticles focused by the ultrasonic waves and inspects the collected microparticles.

11. A flow path through which a fluid containing microparticles flows; An ultrasonic transmitter that transmits ultrasonic waves to the fluid in the flow path by inputting a drive signal; A flow velocity measurement unit that measures the flow velocity of the fluid in the flow path, and a control method for a fluid device, comprising: A control method for a fluid device, wherein the amplitude of the drive signal is set according to a measured flow velocity measured by the flow velocity measurement unit, and the drive signal having the set amplitude is input to the ultrasonic transmitter.

Images