Particulate matter capturing method and particulate matter capturing device

Abstract

To provide a simplified configuration for securing a wider range of particulate matter that can be captured and capturing different types of particulate matter.SOLUTION: A particulate matter capturing method for capturing particulate matter in a fluid is provided, the method comprising preparing a flexible flow channel-forming member having formed therein a flow channel for allowing a fluid to flow, curving the flow channel-forming member and allowing the fluid containing particulate matter to flow through the flow channel in the curved flow channel-forming member, and capturing the particulate matter according to a curvature of the curved flow channel-forming member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method and an apparatus for collecting particulate matter in a fluid. [Background technology]

[0002] The air contains aerosols containing particles such as pollen and yellow sand that can be allergens, as well as various pathogenic microorganisms. Collecting and identifying these particles and microorganisms is desirable as a countermeasure against allergies and diseases. Various devices have been proposed for collecting atmospheric fine particles. A known example of a method for collecting airborne microorganisms is an impactor method (collecting air containing microorganisms by impacting it) (see, for example, Patent Documents 1 and 2 and Non-Patent Documents 1 and 2). Specifically, Patent Document 1 discloses a technique for collecting particles containing microorganisms by ejecting air containing microorganisms from a nozzle and causing the ejected air to collide with a collection surface located opposite the nozzle. Patent Document 2 and Non-Patent Document 2 disclose a device for classifying and collecting particles of different diameters by arranging nozzles with different diameters in stages as nozzles for ejecting aerosol-containing air, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5700594 [Patent Document 2] Special Publication No. 2010-540959 [Non-patent literature]

[0004] [Non-Patent Document 1] Kang, JS et al., "Real-time detection of an airborne microorganism using inertial impaction and mini-fluorescent microscopy", Lab Chip 14, 244-251 (2014) [Non-patent document 2] Tokyo Dylec Co., Ltd. website: https: / / www.t-dylec.net / service / an-200 / (verified February 26, 2024) Summary of the Invention [Problem to be solved by the invention]

[0005] However, when particles, etc. are collected using the impactor method as described above, there is a problem in that the locations where particles, etc. are collected are limited to the collision points on the collection surface where the aerosol, etc. is sprayed. In addition, since the size of particles that can be captured is determined by the spray conditions from the nozzle, etc., if it is desired to capture multiple types of particles, etc., with different sizes, etc., it is necessary to provide multiple stages of the device according to the particle sizes, etc., to capture, resulting in a problem of a complex device configuration. This problem is not limited to the collection of aerosols and microorganisms in the air, but also occurs when collecting granular matter in various fluids. [Means for solving the problem]

[0006] The present disclosure can be realized in the following forms. (1) According to one aspect of the present disclosure, there is provided a particulate matter collection method for collecting particulate matter in a fluid. The particulate matter collection method includes preparing a flexible flow path-forming member having a flow path formed therein for circulating the fluid, bending the flow path-forming member, circulating the fluid containing the particulate matter through the flow path within the curved flow path-forming member, and collecting the particulate matter according to the curvature of the curved flow path-forming member. According to this embodiment of the granular matter collection method, granular matter corresponding to the curvature of the curved flow path forming member can be collected without excessively limiting the collection location. Furthermore, the particle size of the granular matter to be collected can be easily changed by simply changing the curvature of the flow path forming member. Therefore, there is no need to prepare separate flow path forming members or other components for each type of granular matter to be collected, and various types of granular matter can be collected using a common flow path forming member. (2) In the particulate matter collection method of the above aspect, the particulate matter may be collected on the inner wall surface of the flow path in accordance with the curvature of the curved flow path forming member. With this configuration, particulate matter can be collected on the inner wall surface of the flow path provided in the curved portion of the flow path forming member in accordance with the curvature of the curved flow path forming member. Therefore, particulate matter can be collected on the flow path inner wall surface over a relatively wide range, that is, the range in which the flow path forming member has a specific curvature. (3) In the granular matter collection method of the above aspect, the flow path forming member may be curved to a curvature that is preset according to the granular matter to be collected. With this configuration, it is possible to collect the desired granular matter according to the preset curvature. (4) In the granular matter collection method of the above aspect, after the granular matter is collected on the inner wall surface of the flow path, the curved state of the flow path forming member may be released, and the granular matter collected on the inner wall surface of the flow path may be detected. With this configuration, the granular matter collected on the inner wall surface of the flow path can be easily detected while it is still collected on the inner wall surface of the flow path. (5) In the granular matter capturing method of the above aspect, the granular matter may be detected when the curvature of the flow path forming member is 0. With this configuration, when observing the external shape of the granular matter captured on the inner wall surface of the flow path using, for example, a microscope, it is possible to enlarge the focal plane and observe a wider area of ​​the inner wall surface of the flow path on which the granular matter is captured as the same focal plane. (6) In the particulate matter collection method of the above aspect, the flow path forming member may be curved so that the curvature varies depending on the location of the flow path formed inside the flow path forming member. With this configuration, different particulate matter can be collected depending on the curvature at each location of the flow path inside the flow path forming member. (7) According to another aspect of the present disclosure, there is provided a particulate matter collection device for collecting particulate matter in a fluid, the particulate matter collection device including: a flexible flow path forming member having a flow path formed therein for circulating the fluid; and a holding member for bending and holding the flow path forming member at a desired curvature. According to this type of granular matter collection device, by holding the flow path forming member with a holding member and bending the flow path forming member to a desired curvature, granular matter corresponding to the curvature of the curved flow path forming member can be collected without excessively limiting the collection location. Furthermore, by simply changing the curvature of the flow path forming member curved by the holding member, the particle size of the granular matter to be collected can be easily changed. Therefore, there is no need to prepare separate flow path forming members for each type of granular matter to be collected, and a common flow path forming member can be used to collect various types of granular matter. (8) In the particulate matter collection device of the above aspect, the flow path forming member may be made of a silicone resin or an acrylic resin. With this configuration, it is easy to ensure the flexibility of the flow path forming member. The present disclosure can be realized in various forms other than those described above, for example, a method for separating particulate matter in a fluid, a method for detecting and identifying particulate matter in a fluid, and the like. [Brief explanation of the drawings]

[0007] [Figure 1] 3 is a flowchart showing a particulate matter collection method according to an embodiment. [Figure 2] FIG. 2 is an explanatory diagram showing a schematic configuration of a flow path forming member. [Figure 3] FIG. [Figure 4]FIG. [Figure 5] FIG. [Figure 6] FIG. 2 is an explanatory diagram showing a photograph of the particulate matter collection device. [Figure 7] 3A to 3C are explanatory diagrams showing the steps of a particulate matter collection method. [Figure 8] FIG. 2 is an explanatory diagram showing how granular materials having different particle sizes are classified. [Figure 9] FIG. 3 is an explanatory view showing a microscopic photograph of the first sheet. [Figure 10] FIG. 4 is an explanatory view showing a microscope photograph of the first sheet observed at a further magnification. [Figure 11] An explanatory diagram showing the number of lycopodium observed in a micrograph. DETAILED DESCRIPTION OF THE INVENTION

[0008] A. Particulate matter collection method and particulate matter collection device: FIG. 1 is a flowchart showing a granular matter collection method according to an embodiment of the present disclosure. The granular matter collection method of this embodiment is a method for collecting granular matter in a fluid. The granular matter to be collected can be, for example, pollen, viruses, bacteria, fungi including yeast, cells including blood cells and sperm, spores, particles of various pollutants such as particulate matter (PM) in exhaust gas, or a mixture of multiple types of particles, such as a complex of pollen and PM2.5 (PM with a particle size of 2.5 μm or less). Fluids containing such granular matter can be various fluids, such as gases such as air, or liquids such as water, blood, culture medium, and swab fluid (a liquid containing substances attached to a swab used to wipe the surface of an object to be tested). Therefore, the particulate matter collection method of this embodiment can be applied to, for example, pollen, viruses, bacteria, spores, pollutants, etc. in the air; blood cells, bacteria, cancer cells, etc. in blood; cultured cells, sperm, etc. dispersed in culture medium; and bacteria in swab fluid. When carrying out the particulate matter collection method of this embodiment, first, a flow path forming member is prepared (step T100). In step T100 of this embodiment, a holding member 30 is prepared along with the flow path forming member. Below, a particulate matter collection device including a flow path forming member 20 and a holding member 30 will be described as an example of a particulate matter collection device that can be suitably used in the particulate matter collection method of this embodiment.

[0009] FIG. 2 is an explanatory diagram showing a schematic configuration of a flow path forming member 20 provided in the particulate matter collection device. FIGS. 2(A) and 2(C) are side views, and FIG. 2(B) is a top view. In FIGS. 2(A) to 2(C) and FIGS. 3 to 5 described later, mutually orthogonal X, Y, and Z axes are shown to identify directions. The X, Y, and Z axes shown in the figures each indicate the same direction. However, for convenience in the description of FIG. 2, the +Z axis direction is also referred to as "upward," and in the description of FIGS. 3 to 5 described later, the -Y axis direction is also referred to as "upward." Note that FIG. 2 and FIGS. 3 to 5 described later show the layout of each part schematically and do not accurately represent the dimensional ratios of each part.

[0010] The flow path forming member 20 is a flexible member having a flow path formed therein for circulating a fluid. As shown in FIG. 2 , the flow path forming member 20 of this embodiment has a three-layer structure in which three rectangular plate-like members are stacked. That is, the flow path forming member 20 is formed by stacking a first sheet 22, a second sheet 24, and a third sheet 26 in this order. The first sheet 22 and the third sheet 26 are rectangular plate-like members of the same shape and size. As shown in FIG. 2(B) , the second sheet 24 is formed in a U-shape (a shape formed along three sides of a rectangle) in top view. The second sheet 24 is sandwiched between the first sheet 22 and the third sheet 26 to form a flow path 25 through which a fluid flows. The flow path 25 opens at the end side of the flow path forming member 20 in the −X-axis direction, forming an opening 23. The opening 23 functions as an inlet for guiding a fluid into the flow path 25. Furthermore, the first sheet 22 has a through-hole 21 that penetrates the first sheet 22 in the thickness direction near the end of the flow path 25 in the X-axis direction, at a position that overlaps with the flow path 25 in the Z-axis direction. The through-hole 21 functions as an outlet that guides the fluid that has flowed through the flow path 25 to the outside. In Figures 2(A) and 2(B), the outer peripheral portion of the second sheet 24 that is not exposed on the surface of the flow path forming member 20, the flow path 25 formed by the second sheet 24, and the through-hole 21 formed in the first sheet 22 are indicated by dashed lines.

[0011] The first sheet 22, the second sheet 24, and the third sheet 26 are each formed as a flexible member, and the entire flow path forming member 20, which is formed by stacking these sheets, needs only to have flexibility that allows it to be bent with a desired curvature, as described below. The materials constituting the first sheet 22, the second sheet 24, and the third sheet 26 may be, for example, silicone resins such as polydimethylsiloxane (PDMS), cycloolefin resins, acrylic resins, epoxy resins, polyamide resins, etc., and may be selected appropriately taking into consideration the environment in which the granular matter collection device 10 will be used, the types of fluid and granular matter, and the method for detecting the granular matter after collection. When observing the granular matter collected by the granular matter collection device, for example, by an optical method, it is desirable that at least the member constituting the collection surface that collects the granular matter (first sheet 22 in this embodiment) be transparent or translucent. The thickness of each of the first sheet 22, the second sheet 24, and the third sheet 26 may be appropriately selected in consideration of the flexibility and handling properties of the entire flow path forming member 20, and may be, for example, 0.1 mm to 5 mm.

[0012] 3 to 5 are explanatory diagrams showing the appearance of a holding member 30 as an example of a holding member provided in the particulate matter collection device. FIG. 3 is a perspective view, FIG. 4 is a front view, and FIG. 5 is a top view. The holding member 30 is a member for holding the flow path forming member 20 while bending it at a desired curvature. The holding member 30 includes a first holding plate 32 and a second holding plate 36. The first holding plate 32 and the second holding plate 36 are formed by bending rectangular frame-shaped members of approximately the same size in the same direction. That is, the first holding plate 32 and the second holding plate 36 are curved so as to be convex in the -Z axis direction. A rectangular opening 34 is formed in the center of the first holding plate 32, which is formed in a frame shape, and a rectangular opening 38 is formed in the center of the second holding plate 36. The first holding plate 32 is provided with a fastening portion 31 that protrudes upward (in the -Y-axis direction) from the upper edge, and a fastening portion 33 that protrudes downward (in the +Y-axis direction) from the lower edge. The second holding plate 36 is provided with a fastening portion 35 that protrudes upward (in the -Y-axis direction) from the upper edge, and a fastening portion 37 that protrudes downward (in the +Y-axis direction) from the lower edge. A fastening hole 39 that penetrates each fastening portion is formed in the center of each of the fastening portions 31, 33, 35, and 37. The holding member 30 only needs to have the strength to hold the flow path forming member 20, and can be made of, for example, metal, resin, wood, plaster, etc.

[0013] 1 , the flow path forming member 20 and the holding member 30 are prepared. Next, the flow path forming member 20 is curved using the holding member 30 to assemble the particulate matter collection device 10 (step T110). Here, the flow path forming member 20 is disposed between the first holding plate 32 and the second holding plate 36, and the fastening portion 31 of the first holding plate 32 is fastened to the fastening portion 35 of the second holding plate 36, and the fastening portion 33 of the first holding plate 32 is fastened to the fastening portion 37 of the second holding plate 36, thereby bringing the flow path forming member 20 into a curved state, and the flow path forming member 20 is held by the holding member 30. At this time, the first holding plate 32 and the second holding plate 36 of the holding member 30 are formed into a curved shape in advance so that the flow path forming member 20 and the flow path 25 within the flow path forming member 20 are held in a curved state with a desired curvature. The first holding plate 32 and the second holding plate 36 can be fastened together using, for example, bolts and nuts.

[0014] FIG. 6 is an explanatory diagram showing a photograph of a particulate matter collection device 10 in which a flow path forming member 20 is held by a holding member 30. The right side of FIG. 6 shows the particulate matter collection device 10 of this embodiment. As shown in FIG. 6, in the particulate matter collection device 10 of this embodiment, the openings 23 of the flow path forming member 20 open outside the outer periphery of the holding member 30. Furthermore, the through holes 21 of the flow path forming member 20 open in regions overlapping with the openings 34 in the first holding plate 32 of the holding member 30. In step T110, after the flow path forming member 20 is bent using the holding member 30 as described above, a fluid is circulated through the flow paths 25 of the flow path forming member 20, and particulate matter in the fluid is collected on the inner wall surfaces of the flow paths 25 (step T120). Thereafter, the bent state of the flow path forming member 20 is released, and the particulate matter collected on the inner wall surfaces of the flow paths 25 is detected (step T130).

[0015] Fig. 7 is an explanatory diagram showing the state of each step of the particulate matter collection method performed using the particulate matter collection device 10. In Fig. 7, the holding member 30 in the particulate matter collection device 10 is omitted. Fig. 7(A) shows the state of preparing the flow path forming member 20 in step T100, Fig. 7(B) shows the state of step T120, and Fig. 7(C) shows the state of step T130.

[0016] FIG. 7B shows how, in step T120, the openings of the through-holes 21 in the flow path forming member 20 are connected to a pump 50 using a suction pipe 52, and the flow paths 25 of the flow path forming member 20 are suctioned using the pump 50. As a result, air containing granular material 40 flows into the flow paths 25 through the openings 23 of the flow path forming member 20. In this embodiment, granular material 40 having a particle size corresponding to the curvature of the flow path forming member 20, i.e., the curvature of the flow paths 25, is captured on the inner wall surface of the flow path 25, specifically, on the inner wall surface of the first sheet 22 arranged on the convex side. However, unlike FIG. 7B, it is also possible to capture the granular material 40 to be collected on the inner wall surface of the flow path 25, rather than capturing the granular material 40 on the inner wall surface of the flow path 25, by classifying the granular material 40 in the fluid while flowing the fluid through the flow path 25 and then recovering the fluid discharged from the flow path 25 at an appropriate time. With this configuration, the particulate matter 40 can be collected without being limited to a specific location.

[0017] It is known that when a fluid flows through a channel, a secondary flow with a velocity component can occur in a cross section perpendicular to the channel axis. Furthermore, it is known that Dean vortices can occur as secondary flows in curved channels. Specifically, in curved channels, centrifugal force acts on the fluid flowing through the channel, but the magnitude of this centrifugal force is uneven between the channel wall and the center. Furthermore, a pressure gradient acts on the fluid due to the pressure distribution within the channel. These effects result in the formation of a pair of Dean vortices, a pair of vertically symmetrical vortices, near the channel wall. The strength of such Dean vortices (Dean flows) is known to vary depending on the Dean number De, as shown in equation (1) below. In equation (1), Re represents the Reynolds number, r represents the cross-sectional radius of the pipe, and R represents the radius of curvature. The definition of the Reynolds number is shown below in equation (2). In equation (2), ρ represents the fluid density, u represents the fluid velocity, L represents the characteristic length, and μ represents the fluid viscosity coefficient. As shown in equation (2), the Reynolds number Re is defined by an equation that includes the characteristic length L of the fluid, but in a fluid in which particles are dispersed, the particle size can be used as the characteristic length.

[0018]

number

[0019]

number

[0020] It is known that by changing the Dean number De, it is possible to change the position of particles in a fluid in a flow channel perpendicular to the flow direction or to separate particles by size (see, for example, S. Ardabili et al., μTAS 2010). In this embodiment, by bending the flexible flow channel forming member 20 and appropriately setting the curvature (the reciprocal of the radius of curvature R) of the flow channel 25, it is possible to collect particulate matter having a specific particle size. In this embodiment, in particular, the curvature of the flow channel 25 causes the particulate matter to move to the flow channel wall surface, specifically, near the inner wall surface of the first sheet 22, thereby making it possible to collect the desired particulate matter on the flow channel wall surface.

[0021] FIG. 7(C) shows how, in step T130, the flow path forming member 20 is released from its curved state and observed using a camera 54 attached to a microscope as an imaging device to detect and identify the particulate matter 40. Because the flow path forming member 20 is flexible, the curved state can be easily released by removing the flow path forming member 20 from the holding member 30. This allows the flow path forming member 20 to be positioned so that it is flat, i.e., so that the curvature of the flow path forming member 20 is substantially zero. As a result, the focal plane of the flow path forming member 20 during microscopic observation can be expanded, allowing a wider area of ​​the flow path inner wall surface on which the particulate matter is trapped, for example, the entire flow path inner wall surface on which the particulate matter is trapped, to be observed at the same focal plane at once. Note that, when a camera 54 is positioned above the first sheet 22 to observe the outer surface of the first sheet 22 (the surface exposed on the surface of the flow path forming member 20) as shown in FIG. 7(C), the first sheet 22 may be formed using a material with sufficient transparency. Alternatively, prior to observation, the three-layer structure of the flow path forming member 20 may be disassembled to expose the inner wall surface of the first sheet 22 on which the granular substance 40 is maintained, and observation may be performed from this exposed surface side. In such a case, observation can be performed without any problems even if the first sheet 22 is made of an opaque material.

[0022] In addition to the above-described method of observing the appearance of the granular matter, various other methods can be used to detect and identify the granular matter trapped in the flow path 25. For example, a reaction solution that undergoes a specific reaction with the granular matter can be supplied to the flow path 25 in which the granular matter has been trapped, and various reactions can be carried out, such as a reaction that produces chemiluminescence or bioluminescence, a reaction that becomes detectable by fluorescence, or a reaction that involves a color reaction, to detect the granular matter. Depending on the reaction that proceeds between the granular matter and the detection solution, an appropriate detection method can be selected so that the extent of the reaction can be detected. For example, if the granular matter to be detected is bacteria, fungi, pollen, viruses, cells, etc., and antibodies have been obtained, the reaction that causes the luminescence or color reaction described above may include an antigen-antibody reaction. The luminescence or color reaction can be detected visually or using devices such as a camera, photodiode, or photomultiplier tube. In such detection, a light source for detection may be appropriately selected from natural light, ambient light, an LED light, a laser, an incandescent lamp, a mercury lamp, a xenon lamp, etc. The reaction that proceeds between the detection solution and the granular substance may include a reaction accompanied by light emission or color development, as well as an electrical reaction accompanied by, for example, a change in current value.

[0023] Alternatively, when viruses, bacteria, various cells, or the like are collected as particulate matter, the particulate matter may be identified by recovering the collected particulate matter from flow path 25, amplifying nucleic acids as genetic information contained in the particulate matter using, for example, PCR, and determining the base sequence by sequencing. Alternatively, the particulate matter recovered from flow path 25 may be cultured. For example, if the particulate matter is bacteria, the particulate matter may be cultured using an agar medium or the like, or if the particulate matter is cells, the particulate matter may be observed using an appropriate medium selected depending on the cells, and the resulting colonies or cultured cells may be observed, or nucleic acids may be extracted from the particulate matter and analyzed, thereby detecting the particulate matter.

[0024] Furthermore, as described above, when detecting signals such as light emitted by granular matter rather than observing the external shape, there is no need to secure a focal plane as in the case of using optical methods, and therefore granular matter may be detected without releasing the curved state of the flow path forming member 20.

[0025] According to the particulate matter collection method and particulate matter collection device 10 of this embodiment configured as described above, the use of a flexible flow path forming member 20 makes it easy to curve the flow path forming member 20 to a specific curvature, making it possible to collect desired particulate matter. Furthermore, in this embodiment, particulate matter 40 is collected on the inner wall surface of the flow path 25 provided in the curved portion of the flow path forming member 20, according to the curvature of the curved flow path forming member 20. Therefore, particulate matter 40 can be collected on the inner wall surface of the flow path 25 over a relatively wide range, that is, the range in which the flow path forming member 20 has a specific curvature.

[0026] Furthermore, according to this embodiment, the particle size of the granular material 40 to be collected can be easily changed by simply changing the curvature of the flow path forming member 20. Therefore, there is no need to prepare separate flow path forming members or other components for each type of granular material 40 to be collected. A common flow path forming member 20 can be used to collect various types of granular material. Here, as described above, the curvature of the flow path forming member 20 is preset according to the type of granular material to be collected, and a holding member 30 having a shape that can achieve the preset curvature is prepared in advance. This allows the desired granular material to be collected according to the preset curvature. For example, if pollen is to be collected and it is difficult to prepare a sufficient amount of pollen, a preliminary experiment using Lycopodium, a known pollen simulant, may be conducted to determine a curvature suitable for collection in advance.

[0027] 8A and 8B are explanatory diagrams illustrating how granular matter of different particle sizes can be classified by varying the curvature of the flow path forming member 20 when the flow path forming member 20 is curved according to an embodiment of the present invention. FIG. 8A illustrates a state in which the flow path forming member 20 is curved with a smaller curvature, and FIG. 8B illustrates a state in which the curvature is larger. The curvature can be changed by replacing the holding member 30 and depending on the shape of the holding member 30 used; the holding member 30 is not shown in FIG. 8. As shown in FIG. 8, by changing the curvature while using a common flow path forming member 20, the behavior of the granular matter in the fluid flowing through the flow path 25 can be changed, making it possible to collect granular matter of a desired particle size.

[0028] 8 shows a state in which the first discharge path 28 and the second discharge path 29 are connected in parallel to the through hole 21. For example, a flow path switching unit (not shown) may be provided between the first discharge path 28 and the second discharge path 29 and the through hole 21, and the discharge path into which the fluid discharged from the through hole 21 flows may be switched when collecting granular matter from the flow path 25. FIG. 8(A) shows a state in which granular matter is collected via the first discharge path 28, and FIG. 8(B) shows a state in which granular matter is collected via the second discharge path 29. Note that, as in the above-described embodiment, when collecting granular matter on the inner wall surface of the flow path 25, and then changing the curvature of the flow path forming member 20 used to collect a different type of granular matter after collecting granular matter at a specific curvature, the granular matter that has already been collected may be collected from the flow path 25 before changing the curvature. The particulate matter can be collected from inside the flow path 25 by, for example, scavenging or washing the inside of the flow path 25 with a fluid selected according to the particulate matter.

[0029] In the above embodiment, the flow path 25 has an opening 23 at one end thereof as an inlet for introducing a fluid into the flow path 25, and a through-hole 21 at the other end thereof as an outlet for introducing the fluid that has flowed through the flow path 25 to the outside, but a different configuration may be used. For example, the flow path 25 may have inlets at both ends thereof and an outlet at the middle thereof. With such a configuration, for example, by supplying different fluids to the respective inlets, it becomes possible to simultaneously collect granular matter from two types of fluids.

[0030] Furthermore, in the above embodiment, the flow path forming member 20 has a three-layer structure, but may have a different structure. For example, a two-layer structure may be formed by stacking two plate-like members, with a groove structure for forming the flow path 25 provided on the contact surface of one plate-like member with the other plate-like member. Alternatively, the flow path forming member may be formed from a single layer of plate-like member, with the flow path 25 formed as a hole-like structure penetrating such a plate-like member in the longitudinal direction. Furthermore, instead of being a plate-like member with a rectangular cross section, the flow path forming member 20 may be, for example, a tubular member with a circular or elliptical cross section and with through-holes penetrating in the longitudinal direction as the flow path 25.

[0031] Furthermore, in the above embodiment, the flow path forming member 20 is curved at a specific curvature by the holding member 30, but a different configuration may be used. For example, the flow path forming member 20 may be curved in multiple stages so that the curvature varies depending on the location of the flow path 25 formed therein in a single flow path forming member 20. With such a configuration, it becomes possible to capture particulate matter of different particle sizes at different locations of the flow path 25 in the flow path forming member 20.

[0032] Although the holding member 30 is shown in FIGS. 3 to 5 to sandwich and hold the flow path forming member 20 while pressing down on the outer periphery of the flow path forming member 20, other configurations may be used. For example, as long as fluid can be supplied to and discharged from the flow paths 25 of the flow path forming member 20, the first holding plate 32 and the second holding plate 36 may cover a wider area of ​​the flow path forming member 20 and sandwich the flow path forming member 20 without providing the openings 34 and 38. Alternatively, rather than sandwiching and holding the flow path forming member, the holding member may hold both ends of the flow path forming member in the longitudinal direction, which is the direction of fluid flow, and curve the flow path forming member by making the distance between the ends shorter than the longitudinal length of the flow path forming member. In such a case, the desired curvature of the flow path forming member can be achieved by changing the distance between the positions at which both ends of the flow path forming member are held. [Example]

[0033] In the following, an example will be described in which the flow path forming member 20 shown in FIG. 2 and the holding member 30 shown in FIGS. 3 to 5 are fabricated, and the particulate matter collecting device 10 shown in FIG. 6 is assembled.

[0034] <Assembly of particulate matter collector> A flow path forming member 20 and a holding member 30 were fabricated (step T100). In the flow path forming member 20, a 0.2 mm thick sheet made of acrylic resin was used as the first sheet 22, a 1 mm thick sheet made of silicone resin was used as the second sheet 24, and a 3 mm thick sheet made of silicone resin was used as the third sheet 26. The size of the flow path forming member 20 was such that the length in the X-axis direction (length α in FIG. 2(B)), which is the longitudinal direction, was 50 mm, the length in the Y-axis direction (length β in FIG. 2(B)) was 25 mm, the width of the U-shaped second sheet 24 (length γ in FIG. 2(B)) was 7.5 mm, and the diameter of the cross section of the through-hole 21 was 3 mm.

[0035] The holding member 30 was produced using a 3D printer. Then, the flow path forming member 20 was attached to the holding member 30 to assemble the particulate matter collection device 10 shown on the right side of Fig. 6 (step T110). In addition to the curved holding member 30 provided in the particulate matter collection device 10 of the embodiment shown on the right side of Fig. 6, a non-curved, flat plate-shaped holding member 130 was also produced. The left side of Fig. 6 shows a particulate matter collection device 110 as a comparative example, in which the flow path forming member 20 is held using the above-mentioned flat plate-shaped holding member 130. As shown in Fig. 6, the two holding plates that make up the holding members 30 and 130 were fastened together using bolts and nuts.

[0036] <Experiment details> Lycopodium was used as the granular material to be collected. Lycopodium is also used as a pollen bulking agent and is known as a pollen simulant. First, 10 mg of Lycopodium was weighed out onto a paper wrapper using an electronic microbalance. Next, for each of the granular matter collection devices 10 and 110 shown in FIG. 6, the flow path 25 of the flow path forming member 20 was connected to a vacuum pump (pump 50) with a pressure of -0.075 MPa via the through-hole 21, as shown in FIG. 7(B), and the paper-like Lycopodium was sucked into the flow path 25 through the opening 23 (step T120). Thereafter, the flow path forming member 20 was removed from each of the holding members 30 and 130, the three-layer structure of the flow path forming member 20 was disassembled, and the surface of the first sheet 22 on which the flow path 25 was formed was observed under a microscope (step T130).

[0037] Fig. 9 is an explanatory diagram showing a micrograph of the first sheet 22 after particulate matter has been collected. Fig. 9(A) shows the first sheet 22 removed from the particulate matter collection device 10, and Fig. 9(B) shows the first sheet 22 removed from the particulate matter collection device 110. The micrograph shown in Fig. 9 shows the entire first sheet 22, created by pasting together multiple images using a tiling function. As shown in Fig. 9(B), in the particulate matter collection device 110 that performs collection using a flat flow path forming member 20, the collected Lycopodium was sparse in the center of the flow path 25. However, as shown in Fig. 9(A), in the particulate matter collection device 10 that performs collection using a curved flow path forming member 20, it was confirmed that Lycopodium was collected over the entire surface of the flow path 25.

[0038] Figure 10 is an explanatory diagram showing a micrograph of the first sheet 22 near the center of the flow path 25 after particulate matter collection, magnified from Figure 9 . Figure 10(A) shows the first sheet 22 removed from the particulate matter collection device 10, and Figure 10(B) shows the first sheet 22 removed from the particulate matter collection device 110. Figure 11 is an explanatory diagram showing the number of Lycopodium particles observed in the micrograph of Figure 10. The number of Lycopodium particles was counted using image analysis software ImageJ. Specifically, the image was converted into an 8-bit image using ImageJ, and then binarized using the Threshold function within the range of 0-56. The image was then subjected to adjustable watershed with a tolerance of 0.2, and the number of particles was counted using the Analyze particle function. As shown in Figures 10 and 11, it was confirmed that the particulate matter collection device 10 can collect significantly more Lycopodium particles than the particulate matter collection device 110.

[0039] The present disclosure is not limited to the above-described embodiments, and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0040] The present disclosure can also be realized in the following forms. [Application example 1] A particulate matter collection method for collecting particulate matter in a fluid, comprising: preparing a flexible flow path forming member having a flow path formed therein for allowing the fluid to flow; The flow path forming member is curved, The fluid containing the particulate matter is caused to flow through the flow path in the curved flow path forming member, and the particulate matter is collected in accordance with the curvature of the curved flow path forming member. Particulate matter collection method. [Application example 2] The particulate matter collection method according to Application Example 1, The particulate matter is collected on the inner wall surface of the flow path according to the curvature of the curved flow path forming member. Particulate matter collection method. [Application example 3] The particulate matter collection method according to Application Example 1 or 2, The flow path forming member is curved at a curvature that is set in advance depending on the particulate matter to be collected. Particulate matter collection method. [Application example 4] The particulate matter collection method according to any one of Application Examples 1 to 3, After collecting the particulate matter on the inner wall surface of the flow path, the curved state of the flow path forming member is released, and the particulate matter collected on the inner wall surface of the flow path is detected. Particulate matter collection method. [Application example 5] The particulate matter collection method according to Application Example 4, The detection of the particulate matter is carried out when the curvature of the flow path forming member is 0. Particulate matter collection method. [Application Example 6] The particulate matter collection method according to any one of Application Examples 1 to 5, The flow path forming member is curved so that the curvature varies depending on the location of the flow path formed inside the flow path forming member. Particulate matter collection method. [Application Example 7] A particulate matter collection device for collecting particulate matter in a fluid, comprising: a flexible flow path forming member having a flow path formed therein for allowing the fluid to flow; a holding member for holding the flow path forming member while bending it at a desired curvature; Equipped with Particulate matter collection device. [Application Example 8] The particulate matter collection device according to Application Example 7, The flow path forming member is made of silicone resin or acrylic resin. Particulate matter collection device. [Explanation of symbols]

[0041] 10,110...Particulate matter collection device 20...flow path forming member 21...Through hole 22...1st seat 23...Opening 24...Second seat 25...Flow path 26...Third seat 28…1st discharge path 29…Second discharge path 30, 130...Retaining member 31... Fastening part 32...1st holding plate 33... Fastening part 34...Opening 35... Fastening part 36...Second holding plate 37... Fastening part 38...Opening 39...Fastening hole 40...Particulate matter 50...Pump 52...Suction tube 54...Camera

Claims

1. A particulate matter collection method for collecting particulate matter in a fluid, comprising: preparing a flexible flow path forming member having a flow path formed therein for allowing the fluid to flow; The flow path forming member is curved, The fluid containing the particulate matter is caused to flow through the flow path in the curved flow path forming member, and the particulate matter is collected in accordance with the curvature of the curved flow path forming member. Particulate matter collection method.

2. 2. The particulate matter collection method according to claim 1, The particulate matter is collected on the inner wall surface of the flow path according to the curvature of the curved flow path forming member. Particulate matter collection method.

3. 2. The particulate matter collection method according to claim 1, The flow path forming member is curved at a curvature that is set in advance depending on the particulate matter to be collected. Particulate matter collection method.

4. 3. The particulate matter collection method according to claim 2, After collecting the particulate matter on the inner wall surface of the flow path, the curved state of the flow path forming member is released, and the particulate matter collected on the inner wall surface of the flow path is detected. Particulate matter collection method.

5. 5. The particulate matter collection method according to claim 4, The detection of the particulate matter is carried out when the curvature of the flow path forming member is zero. Particulate matter collection method.

6. 2. The particulate matter collection method according to claim 1, The flow path forming member is curved so that the curvature varies depending on the location of the flow path formed inside the flow path forming member. Particulate matter collection method.

7. A particulate matter collection device for collecting particulate matter in a fluid, comprising: a flexible flow path forming member having a flow path formed therein for allowing the fluid to flow; a holding member for holding the flow path forming member while bending it at a desired curvature; Equipped with Particulate matter collection device.

8. 8. The particulate matter collecting device according to claim 7, The flow path forming member is made of silicone resin or acrylic resin. Particulate matter collection device.

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