JP2008104927A - Device for sorting fine particle in fluid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fine particle sorting device which selectively recovers fine particles contained in a fluid, or selectively recovers a fluid from which fine particles have been removed. <P>SOLUTION: The fine particle sorting device comprises a flow channel 20b through which a fluid flows, a fine particle monitoring mechanism for predicting the path of the fine particles in the fluid, and a nozzle 17 for selectively recovering the fine particles, or selectively recovering the fluid while avoiding the fine particles from the prediction by the fine particle monitoring mechanism. When image analysis by the fine particle monitoring mechanism shows that a bubble comes near to the tip end of the suction nozzle 17, a pump 14 is stopped so as not to suck the bubble from the suction nozzle 17. After the bubble passes the tip end of the nozzle and the possibility of sucking the bubble disappears, the pump 14 is actuated to suck the fluid again. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention is a device that can continuously supply a liquid that does not contain bubbles and fine particles that are removed from the bubbles by removing bubbles and fine particles that are floating in the liquid, a device that can remove the fine particles in the gas and continuously supply a gas that does not contain them. Alternatively, the present invention relates to an apparatus for selecting fine particles in liquid or gas and selectively supplying them.

If bubbles or fine particles are mixed in a fluid used in a production line such as microfabrication of a semiconductor device, a serious problem may occur.
In addition, if bubbles are mixed in ink used in the ink jet recording apparatus, the printing screen of the printer becomes faded, and in the case of a color printer, there is a problem of different colors. In this case, as a method for detecting air bubbles in the ink flow path and in the ink chamber, (1) a pressure fluctuation is generated in the ink and the pressure change is detected, and (2) a sound wave (for example, an ultrasonic wave) is applied to the ink. (3) A voltage is applied to the ink to detect a voltage change, (4) The ink is irradiated with light, and the light reflectance or The thing which detects the transmittance | permeability is mentioned. In addition, (5) a method of detecting a fluctuation in resonance frequency inherently present depending on the shape of the ink flow path and the ink chamber and the amount of ink is cited (see Patent Document 1).

  However, these methods are methods for detecting bubbles in the ink chamber, and are not methods for removing bubbles and collecting only ink. There is also a problem that the ink component is altered by applying an electric field to the ink component.

When air is mixed in a pipe filled with liquid and air bubbles are generated, the air bubbles are sucked into a pump disposed in the middle of the pipe and the pump may be idle.
As a device for removing such bubbles, a bubble detection device and a bubble removal device are cited (see Patent Document 2). This bubble detection device uses electrodes, but there is no 100% certainty for both detection and removal, and it is sufficient for removing large bubbles for the purpose of preventing the pump from spinning around. It cannot be used as an apparatus for removing fine particles in an ink jet recording apparatus.

  There has also been proposed an apparatus for feeding bubbles mixed in a micropump that handles a small amount of fluid (see Patent Document 3). However, this device is intended to prevent air bubbles from being mixed, and is a realization level in which air bubbles are difficult to be mixed. It is not a device that actually removes or sorts fine particles such as air bubbles.

JP 2000-296614 A JP-A-7-243895 JP 2006-4834 A

  The conventional bubble removal devices are aimed at large-sized bubbles, and are only for the purpose of preventing bubbles from being mixed. Remove and collect fine particles mixed in the fluid, or select fine particles. It is not a device for automatic recovery.

  Accordingly, an object of the present invention is to provide a fine particle sorting apparatus that selectively collects fine particles contained in a fluid or selectively collects a fluid from which fine particles have been removed.

  The fine particle sorting apparatus in the fluid of the present invention selectively collects the fine particles based on the flow path through which the fluid flows, the fine particle monitoring mechanism for predicting the traveling path of the fine particles in the fluid, and the prediction by the fine particle monitoring mechanism, or And a fine particle sorting mechanism that selectively collects fluid while avoiding fine particles.

  An example of the fluid is a liquid, and the fine particles in that case include bubbles.

  Gas can also be used as another example of the fluid.

  When the fine particle sorting apparatus is used as a device for selectively recovering fluid, an example of the fine particle sorting mechanism is a nozzle mechanism for sucking fluid from a fixed tip portion, and the fine particle nozzles for the fluid around the tip portion. And a fluid movement mechanism that causes displacement to move to a position where the mechanism is not sucked.

  The displacement for moving the fine particles by the fluid moving mechanism is caused by a liquid flow or an air flow.

  The fluid movement mechanism moves the fluid by any one of a method of applying an electric field or a magnetic field, a method of generating a sound wave by a piezoelectric element, and a method of deforming a shape memory alloy by heating or cooling by a heater or a Peltier element. Can be made.

  As another example of the fine particle sorting mechanism, a mechanism including a nozzle mechanism that sucks fluid from the tip and is supported so as to be movable, and a nozzle drive mechanism that drives the movement of the nozzle mechanism. Can do.

  The nozzle drive mechanism can drive the movement of the nozzle mechanism by an actuator based on any one of a piezoelectric element, an electromagnetic solenoid, static electricity, a shape memory alloy, air pressure, or liquid pressure.

  The fine particle sorting apparatus of the present invention includes a plurality of branch flow channels branched from a flow channel through which fluid flows, a fine particle monitoring mechanism for monitoring the presence or absence of fine particles in the fluid in each branch flow channel, and two each of the branch flow channels. Particulate-containing flow that merges each flow path branched into one flow path into a single flow path and a flow path that does not contain fine particles into a single flow path that merges the other flow paths from each branch flow path. And a flow path switching mechanism that is provided at each branch point of each branch flow path and switches the flow path based on monitoring by the fine particle monitoring mechanism.

  Each channel and the channel switching mechanism can be formed on a common substrate by microfabrication (for example, micromachine technology).

  An example of the fine particle sorting apparatus is that the flow path is a groove formed in the substrate by an etching technique, the flow path switching mechanism is formed by an etching technique, and serves as a valve and a valve seat. Mention may be made of using either sound waves or light waves.

  An example of the fine particle monitoring mechanism includes an image pickup device that picks up the position of the fine particles in the flow passage with time, and a calculation unit that calculates the traveling path of the fine particles based on the image pickup result.

  In order to focus on the fine particles in the fluid, the imaging device is preferably adjusted so that the depth of field is longer than the depth of the flow path.

  Further, the computing means is adjusted so that the depth of field is shorter than the depth of the flow path, and the traveling path of the fine particles can be calculated three-dimensionally based on the image information obtained from the imaging device.

  Since the fine particle sorting apparatus of the present invention includes a fine particle monitoring mechanism and a fine particle sorting mechanism, the fine particles in the fluid can be selectively collected or the fluid can be selectively collected while avoiding the fine particles in the fluid. Can do.

  When the fluid is a liquid, for example, it is possible to remove or collect bubbles mixed in an ink jet or a medicine.

  When the fluid is a gas, it can be used in the manufacturing process after removing fine particles in the gas used in the semiconductor manufacturing process. Then, by removing fine particles from the fine particles in the gas or determining the shape of the fine particles, only specific fine particles can be captured and collected.

  In a fine particle sorting mechanism that selectively collects fluid, a nozzle mechanism that sucks fluid from a fixed tip portion and a displacement that moves to a position where the fine particle is not sucked by the nozzle mechanism are generated with respect to the fluid around the tip portion. If the fluid moving mechanism is used, the fine particles can be removed while the position of the nozzle is fixed, so that monitoring by the fine particle monitoring mechanism becomes easy.

As a fluid movement mechanism, a method of applying an electric field or a magnetic field, a method of generating a sound wave by a piezoelectric element, and a method of deforming a shape memory alloy by heating or cooling by a heater or a Peltier element can be used.
The method of applying an electric field is effective when there is a difference in charge between the fluid and the fine particles, and the condition is that the charge is stable. The condition is that at least one of the fluid and the fine particles is a non-conductor. Liquids that do not contain ions, such as organic solvents composed of CH groups, are suitable for use because they have low electrical conductivity and are easily charged. The method using an electric field has a charge application step before the process of separating by an electric field, and there is an effect that the applied charge amount and polarity can be adjusted there.

  The method of applying a magnetic field is effective when the magnetic fluid or the fine particles are composed of iron powder or the like. In the case of a system that contains a solvent containing magnetic material and a fine particle that does not, the external magnetic field clearly moves the solvent, but the fine particle follows the movement of the solvent, and the force does not act directly. There is a delay. There is also a method of using the time delay. It can also be used as a means for separating fine particles that respond to magnetic force and fine particles that are not.

A method using a sound wave by a piezoelectric element has a feature in that it is a movement of a fluid irrespective of a difference in physical properties between an electric field and a magnetic field because of a dynamic physical property. The mechanical properties are specific gravity, viscosity, fine particle shape, and sound velocity, and enable local movement of the fluid by sonic energy due to the characteristic difference.
The method of deforming the shape memory alloy by heating or cooling with a heater or a Peltier element is a method in which the position displacement is caused directly by the temperature of the shape memory alloy, and thus can be applied to any fluid.

  As another example of the fine particle sorting mechanism, if a fluid is sucked from the tip portion, and a nozzle mechanism that is supported so that the tip portion is movable, and a nozzle drive mechanism that drives the movement of the nozzle mechanism, It becomes possible to respond quickly to the fine particles, and the fine particles can be removed or selected more reliably.

As the nozzle driving mechanism, a piezoelectric element, an electromagnetic solenoid, static electricity, a shape memory alloy, a mechanism that drives the movement of the nozzle mechanism by an actuator of air pressure or liquid pressure can be used.
The method using a piezoelectric element is a simple method with a displacement of several tens of microns or less, and a quick response can be obtained.
The method using an electromagnetic solenoid is effective for obtaining a displacement greater than or equal to the displacement of the piezoelectric element, and has good displacement accuracy and control performance.
The method using static electricity has a limited device flexibility because the device has not been developed so much, but it is a device that can operate reliably even under strong magnetic field conditions, so it is stable even in the presence of a magnetic field. For example, it can be employed in a device that is embedded in a human body. This is because the patient is required to continue operation with high reliability even when the patient enters a strong magnetic field such as an MRI (Magnetic Resonance Imaging) apparatus.

The shape memory alloy method uses position displacement due to its temperature, and may be poor in time response due to temperature propagation delay, but is highly reliable because it is a simple mechanism system.
The method using air pressure is difficult to miniaturize, but is simple and highly reliable in the case of a nozzle mechanism system of several millimeters or more. In addition, there are many types and manufacturers of actuators, and there is a degree of freedom in design, and costs can be reduced. The liquid pressure is basically only the pressure medium changed from air to liquid, but specifically there is a hydraulic actuator. In this case, miniaturization is difficult, but it is useful when it is necessary to move the nozzle with a strong force. For example, if the nozzle is in a very viscous liquid and it needs to be moved reliably.

A plurality of branch flow channels, a fine particle monitoring mechanism for monitoring the presence or absence of fine particles in the fluid, a fine particle-containing flow channel in which one flow channel of each branch flow channel is combined into one flow channel, and each branch flow And a flow path switching mechanism for switching the flow path based on the monitoring by the fine particle monitoring mechanism. Good.
When a plurality of channels are used, the flow rate can be increased. The channel width is determined by the size of the detected fine particles and bubbles. The channel depth is also limited by the ability of the subject depth of the imaging device such as a camera. For this reason, there is an upper limit for the flow rate of a single flow path, and when a flow rate higher than that is required, a plurality of flow paths are preferable.

Examples of the present invention will be described in detail below.
[Example 1]
1A and 1B are schematic views for explaining an embodiment of the present invention, FIG. 1A is an overall configuration diagram of a fine particle sorting apparatus, FIG. 1B is a cross-sectional view of a portion (cell portion) of FIG. And (D) are enlarged cross-sectional views of the portion b (nozzle tip portion) of (B), (C) is a diagram showing the path of the bubble with an arrow, and (D) is to move the nozzle 17 while avoiding the bubble. It is a figure explaining operation | movement.

A liquid as a fluid is stored in the tank 11 and is circulated in the direction of the arrow in the flow path by liquid feeding by the pump 13. At this time, the liquid is desirably circulated at a constant flow rate.
The cell 15 is provided in a flow path through which the liquid circulates, and a nozzle 17 for collecting the liquid is inserted from the upper part of the cell 15. Liquid recovery by the nozzle 17 is performed by a pump 14 connected to a subsequent stage.

The cell 15 is made of glass, for example, and has an internal shape of 2 mm in thickness, 10 mm in width, and 20 mm in length. Reference numerals 19 and 21 denote joints for connecting the cell 15 and the fluororesin tubes 20a and 20b.
The nozzle 17 is made of glass, and the inner diameter of the nozzle tip is about 100 μm.
The nozzle 17 has a nozzle tip that can move substantially to the left and right so as to avoid particles in the fluid by the nozzle drive mechanism (actuator 23) based on the prediction of the travel path by the particle monitoring mechanism. The fine particle monitoring mechanism will be described later.

The actuator 23 includes a coil 25 and a magnet 27. The nozzle 17 is rotatably supported with a fluorine packing 29 as a fulcrum. By supplying a predetermined current to the coil 25, the tip of the nozzle 17 moves in the cell 15.
The liquid sucked by the nozzle 17 is recovered from the recovery tube 43 via the flexible tube 31 and the pump 14. The tube 31 can be made of, for example, fluorine rubber.

  As another example of the nozzle drive mechanism in the embodiment, a piezoelectric element is used at the same location, and an actuator that expands and contracts at a predetermined voltage, an actuator that is controlled by air pressure, and a shape memory alloy are heated to an appropriate temperature and controlled. Examples include a micro heater or a micro Peltier element that can be heated or cooled to control and drive the temperature of the shape memory alloy.

[Particle monitoring mechanism]
A camera as an imaging device is installed so that the tip of the suction nozzle is at the top of the image and the focus is slightly below. When the depth of field in the Z-axis direction is set to ± 500 μm, bubbles having a diameter of at least 10 μm can be captured. In FIG. 1B, b is the image area. The size of the imaging area is, for example, 1.8 mm × 2.5 mm. 30 images are acquired per second, and the presence / absence of bubbles, the position of bubbles, and the velocity of bubbles can be obtained from the continuous images. The image data is sent to a computer and analyzed on-line to predict the path of fine particles. Based on the prediction by the fine particle monitoring mechanism, the suction nozzle 17 as the fine particle selection mechanism is moved one-dimensionally, two-dimensionally or three-dimensionally, and suction is performed so as to avoid bubbles.

Next, the movement model of the fine particles calculated by the calculation means and the operation of the nozzle will be described with reference to FIGS.
In FIG. 1D, coordinates are designated for the following explanation.
The center of the tip of the nozzle 17 is the zero point of the X axis and Y axis, and is expressed as (0, 0) as coordinates (X, Y). This is the home position of the nozzle 17. The downward direction in the figure is the positive direction of the Y axis. Further, the front direction perpendicular to the paper surface is defined as the positive direction of the Z axis.
In (D), the tip of the nozzle 17 performs a circular motion around the packing 29, but can be regarded as a straight line when the deflection angle is very small. The straight line is called a nozzle scanning line.

The position coordinates of the bubbles are expressed as (x (t), y (t)) from the image at time t.
When a plurality of bubbles are designated, the first position coordinate is represented as (x1 (t), y1 (t)), and the i-th position coordinate is represented as (xi (t), yi (t)). Bubbles can usually be represented by “circles”, but in reality they may be elliptical or deformed. In the description here, even in a circle, an ellipse, and other shapes, the position coordinates are represented as the position coordinates. Then, the bubble velocity is obtained from the image at a certain time t1 and the image at the subsequent time t2.

The velocity of bubble i at time t is expressed as (vi (t), wi (t)). Next, the bubble is approximated to a “circle” as a parameter for designating the shape of the bubble. At this time, the size of the bubble is designated by the radius p of the maximum circle for the purpose of avoiding the bubble. That is, even if an actual bubble has an elliptical shape, for example, a circle whose center is the center of gravity of the bubble is the smallest circle that fits in the circle and is regarded as a circular shape. The radius of the minimum circle at that time is p.
Next, if necessary, the shape of the bubble is approximated to an ellipse, the major axis q and the minor axis r are designated, and the major axis angle is designated by s. Here, s is an angle formed between the major axis of the ellipse and the X axis. s takes a value from -π to + π radians. The shape data of the bubble i at time t is represented by (pi (t)) or (pi (t), qi (t), ri (t), si (t)). If necessary, a parameter for specifying the bubble shape may be added.

As described above, as the bubbles, position data (xi (t), yi (t)) for each time, velocity data (vi (t), wi (t)), and shape data (pi (t), qi (t) ), ri (t), si (t)) are added by a computer (calculation means).
If the bubble deviates from the depth of field of the camera (particulate monitoring mechanism) and clearly deviates from the Z-axis direction of the nozzle, the capture of the bubble by the computer is stopped at that point, and conversely, Bubbles that have entered the depth of field and are likely to approach the nozzle are added with the data from that point and captured by the computer.

  In addition, one bubble may be separated or a plurality of bubbles may be combined into one. In that case, the calculation means determines whether it is another bubble or one bubble from the bubble shape, and updates the registration of the data.

  A case where the nozzle moves in three dimensions will be described. If there is a large difference between the nozzle tip and the Z-axis direction in the measurement of the bubble in the Z-axis direction due to the depth of field of the camera, the bubble image is blurred because the camera is focused on the nozzle tip. Sometimes. From the degree of blur, the position coordinate of the Z axis can be estimated. Further, when there is a time allowance between the image acquisition and the bubble flow velocity, the bubble Z-axis position can be obtained by shifting the focal position of the camera.

Let t0 be the latest image acquisition time, and then the position of bubble i at time T is
T = t0 + Δt (1-1)
xi (T) = xi (t0 + Δt) = xi (t0) + vi (t0) · Δt (1-2)
yi (T) = yi (t0 + Δt) = yi (t0) + wi (t0) · Δt (1-3)
Can be guessed.

  Here, the time Tc when yi (Tc) = 0 is the time when the center of gravity of the bubble i crosses the nozzle scanning line. Since the bubble has a size, a part of the bubble crosses the nozzle scanning line at time Td when yi (Td) = pi (t0). Further, the time Te that completely passes through the nozzle scanning line can be obtained by solving yi (Te) = − pi (t0).

And
Tc = t0 + Δtc (2-1)
Td = t0 + Δtd (2-1)
Te = t0 + Δte (2-1)
.DELTA.tc = -yi (t0) / wi (t0) (3-1)
Δtd = [pi (t0) -yi (t0)] / wi (t0) (3-1)
Δte = [-pi (t0) -yi (t0)] / wi (t0) (3-1)
It becomes.

Using this, if Δtd ≦ Δt ≦ Δte,
xi (t0 + Δt) = xi (t0) + vi (t0) · Δt-{(pi (t0) ² -[(vi (t0) · (Δt-Δtc)] ² } ^1/2 (4-1)
From
xi (t0 + Δt) = xi (t0) + vi (t0) · Δt + {(pi (t0) ² -[(vi (t0) · (Δt-Δtc)] ² } ^1/2 (4-1)
Is a region where bubbles pass through the nozzle scanning line.

Next, the operation of this embodiment will be described.
FIG. 1C is an explanatory view showing the movement of bubbles. The pump 13 is set to flow at a constant flow rate so that bubbles are in a constant linear motion as much as possible in the area photographed by the camera. The camera image acquisition interval and its image processing time are as follows. Select the flow rate so that the suction nozzle control time is sufficient.

  Further, a function of fixing the position of the suction nozzle 17 and controlling the liquid suction speed from the suction nozzle 17 may be provided. According to the image analysis by the particle monitoring mechanism, when a bubble approaches the tip of the suction nozzle 17, the pump 14 is stopped so that the bubble is not sucked from the suction nozzle 17. Then, air bubbles are prevented from entering the collection tube 43. If the bubbles pass through the nozzle tip and there is no possibility of sucking the bubbles, the pump 14 is operated to suck the liquid again.

  In FIG. 2A, the horizontal axis is time Δt, the vertical axis is the nozzle scanning line of xi (t0 + Δt), and the area where bubbles pass is hatched. In this case, even if the bubbles are recognized as “circles” on the computer, they may be elliptical depending on the velocity direction of the bubbles crossing the nozzle scanning line. FIG. 2A is a map in which the position of the bubble on the nozzle scanning line is predicted after the time Δt from the time t0. If a continuous curve is created in a place other than the hatched area and the nozzle tip is moved there, if the prediction is certain, bubbles can be avoided at the nozzle tip.

  However, in reality, depending on the position of the bubble, a continuous curve cannot be created, or the nozzle drive system has a mass and is driven by a finite force, so the acceleration may naturally be limited. Since the second derivative value of the curve that is acceleration and the first derivative value that is the speed are within a certain range, and the nozzle drive range can only operate within a limited range from the home position, Axis values are limited. Taking these restrictions into consideration, a curve is created by a computer so as to be as continuous as possible.

  If the nozzle is moved too fast, turbulence will occur in the liquid near the nozzle tip, causing the bubble trajectory to be inadvertently changed. Moreover, if it becomes extremely fast operation (for example, speed exceeding a sound speed), it will be in a vacuum state locally and will be deaerated and a new bubble will be produced. It is desirable to prevent such a high-speed movement and to adopt a streamline structure that hardly disturbs the filled medium with respect to the movement of the nozzle portion in the X-axis direction.

  FIG. 2B is an example in which a curve is created as the trajectory of the nozzle tip when bubbles 1 to 4 are present. 2B is time t0, and FIG. 2C is t1. The coordinates of bubbles 1 to 4 change with time. At t1, the bubbles 1 and 2 have passed the nozzle tip, so they are no longer relevant for calculating the tip trajectory of the nozzle 17. Instead, in FIG. 2C, a new bubble 5 is generated, and a curve taking that into consideration is created at that time.

  This continuous curve is updated every time an image is acquired. The case of FIG. 3 is an example in which a continuous curve cannot be made, and the tip of the nozzle comes into contact with the bubble 1 or the bubble 3. In that case, a predetermined alarm is given to the outside, and at the same time, the pump 14 is stopped and the suction of the liquid is stopped. Then, the tip of the nozzle is forcibly moved to a position free of bubbles, a continuous curve is created therefrom, and liquid suction is resumed.

  In the above method, the creation of a continuous curve for moving the nozzle tip is obtained by calculation with a computer. When the calculation increases the computer load, the following method can be used to reduce the load. Obtaining the position and shape of the bubble from the latest image is the same as the previous example, but the following potential function is obtained for each bubble.

Ui = pi ³ / [(xi -xn) ² + (yi -yn) ² ] ^1/2 (5-1)
Here, (xi, yi) is the position of the bubble i, and (xn, yn) is the position of the nozzle tip at the time of the latest image acquisition. Pi is the radius of the bubble. The nozzle position is yn = 0 in the coordinate system of FIG.
The reason why pi is raised to the third power is only to assume a mass of gravitational gravitation in terms of mechanics, and it need not be. Add this Ui by the number of bubbles and let it be U.
U = U1 + U2 + U3 + ... + Um (5-1)
It is.

The following partial differential function is obtained for this at the nozzle position (xn, yn) = (xn, 0). Then
F = −∂U / ∂x (6-1)
It becomes.
This corresponds to the force in the X-axis direction obtained from the potential function U. For example, if it is considered that the bubble has an electric charge and the electric charge of the same sign is also present at the nozzle tip, the charge amount of the bubble is proportional to the cube of its size. In this state, repulsive force acts on each nozzle tip from each bubble.

However, since the repulsive force is inversely proportional to the square of the distance, the force from the bubbles far from the nozzle tip is weak, and the influence of the nearby bubbles becomes large. F is a force applied to the nozzle tip. In this case, it is desirable to add a force corresponding to a frictional force proportional to the minus of the moving speed of the nozzle to the previous force F to prevent vibration of the nozzle tip. Then
F = −∂U / ∂x−f × (dxn / dt) (6-1)
It becomes.

Here, dxn / dt is the speed of the nozzle tip in the x-axis direction, and f is a parameter.
f is set to an optimum value by the mass of the nozzle and the force for controlling the nozzle. As f increases, the responsiveness of the movement of the nozzle tip deteriorates, but the movement becomes smooth.
By doing so, the nozzle tip moves while avoiding bubbles without performing complicated calculations.

  In this example, the bubble size is not taken into consideration, but it is desirable to use a potential function U that takes that into consideration. In addition, the potential inversely proportional to the distance is assumed because it is only an analogy from the charged repulsive force or universal gravitational force, and the potential inversely proportional to the distance derives a force inversely proportional to the square of the distance. The potential function may be a function that is inversely proportional to the square of the distance, or may be a function that becomes smaller and becomes smoother if possible.

[Example 2]
Example 1 was bubbles in the liquid, but now we will describe the separation of particulates in the gas. When it is desired to select only specific particles from particles (for example, metal fine particles) floating in the gas, the following is performed.
As an example, for hay fever that occurs in early spring, only specific pollen is collected from fine particles floating in the air, and the damage to the hay fever patient at that measurement point is measured from the amount collected per hour. This is the case. The size of the pollen is 20 μm to 40 μm, and its shape varies depending on the type of plant.

4A is an electron micrograph of chrysanthemum, FIG. 4B is mimosa, and FIG. 4C is nerine.
Although the fluid of Example 1 was a liquid, when the fluid is a gas, when only a specific particle floating in the gas is captured in the camera image, the force obtained from the potential energy Ui is not a repulsive force but an attractive force. To do. In that case, it is only necessary to change the sign of the potential function of the first embodiment. Then, the nozzle tip performs an operation of being attracted to the specified particle, and only the specific particle can be sucked.

In order not to suck other particles carelessly, the pump is operated after the identified particles come near the nozzle tip. The size of the pollen is 20 μm to 40 μm, but it is necessary to enlarge the image as compared with Example 1 in order to specify the structure.
The image areas in FIGS. 1C and 1D are 0.3 mm × 0.4 mm. In addition, since the pollen moves more intensely than in the liquid due to Brownian motion, the image acquisition is performed at a high speed of 100 images / second, and the temperature of the measurement unit is lowered to reduce Brownian motion.

[Example 3]
5A and 5B are schematic views showing still another embodiment of the present invention, in which FIG. 5A is an overall configuration diagram, and FIG. 5B is an enlarged cross-sectional view at a portion b of FIG.
Unlike Example 1, the means for avoiding bubbles is different. The suction nozzle 17 is fixed, and a pair of piezoelectric elements 33 (33a, 33b) is installed in the vicinity of the tip as a fluid movement mechanism. When one piezoelectric element 33a is extended, the other piezoelectric element 33b is controlled to be contracted. .
By expanding and contracting the piezoelectric element 33, a force is applied to the bubble in a direction perpendicular to the central axis of the nozzle 17 (left and right direction in the drawing: X direction), and the orbit of the bubble is removed from the axial position of the suction nozzle 17. The operation of the piezoelectric element 33 is merely the movement of the piezoelectric element instead of the movement of the nozzle 17 in the first embodiment, and the basic control is the same as in the first embodiment.

  In this embodiment, the liquid at the neighboring point is moved by expansion and contraction of the piezoelectric element 33 to avoid bubbles, but the piezoelectric element 33 generates a sound wave of the liquid by making the applied voltage into a short-time pulse. It is possible to make it. Although it is possible to use a force that directly radiates sound waves to the fine particles and pushes them in the traveling direction of the sound waves, i.e., acoustic radiation pressure, it is difficult to control the radiation direction. It is efficient to use the power from there.

  (1) A sound wave having the same frequency is constantly applied to the liquid from the pair of left and right piezoelectric elements 33 to form a standing wave sound field between the piezoelectric elements. (2) Sound pressure nodes and antinodes are alternately present at intervals of ¼ wavelength in the sound wave propagation direction. (3) A minute object that is sufficiently smaller than the wavelength of a sound wave receives a force from the antinode of the sound pressure toward the node, and has a physical phenomenon that is captured by the node of the sound pressure.

Using this method, the bubbles can be moved left and right by sound waves. Specifically, the bubbles flowing near the nozzle 17 are trapped by a standing wave, and then the bubbles are moved left and right by changing the phase of the sound wave. If you come to a course that does not enter the nozzle tip (traveling path), the sound wave intensity is set to zero and the trap is released. In addition, it is also possible to control so that bubbles are removed from the vicinity of the nozzle by adjusting the wavelength and intensity of the sound wave.
In this embodiment, a pair of piezoelectric elements is used, but only one of the piezoelectric elements may be used.

[Example 4]
Next, still another embodiment of the present invention will be described.
FIG. 6A is an overall configuration diagram of the fine particle sorting apparatus, and FIG. 6B is an enlarged cross-sectional view of the portion a in FIG.
The liquid from which bubbles are to be removed is stored in the tank 11 and circulated in the direction of the arrow in the flow path by the pump 13.

  The tube 20b connected to the tank 11 is branched into eight transparent thin tubes 35a to 35h. Each tube 35a to 35h has an inner diameter of 1 mm and an outer diameter of 2 mm, and can be immediately recognized from the outside if bubbles are introduced. The material is a fluorine-based resin. In the fourth embodiment, the eight tubes 35a to 35h are installed flat so that a single camera can shoot in a focused state. In addition, three-way valves 37a to 37h as flow path switching mechanisms are attached to each tube.

  The eight tubes 35a to 35h are branched into two at the branch points provided with the three-way valves 37a to 37h, respectively, and one of the branch tubes is one microparticle-containing tube (flow path) for collecting the liquid. 39, and the other tube via the three-way valves 37 a to 37 h is connected to the collection tube 43. 19a, 19b and 21 are joints for connecting the tubes.

From the camera image, it is monitored which bubble enters the tube and at which position the bubble moves and at what speed. When the air bubbles come near the three-way valves 37a to 37h, the three-way valve is switched to flow the air bubbles in another direction (for example, the fine particle-containing tube 39 side). Thereafter, if the bubbles are removed, the three-way valves 37a to 37h are returned to the original particle-free tube (flow path) 40 side, and only the fluid is recovered from the tube 43.
The liquid exiting from the collection tube 43 is a liquid from which bubbles have been completely removed. The camera image also monitors the piping side without bubbles of the three-way valves 37a to 37h, that is, the piping to the tube 40, and may output an alarm signal when bubbles flow into the piping due to some trouble.

[Example 5]
Next, still another embodiment of the present invention will be described.
FIG. 7 is a schematic view of a chip-type particle sorting apparatus, (A) is a top view, (B) is a left side view of (A), (C) is an EF cross-sectional view of (A), and (D) is (A) is a right side view, (E) is a CD sectional view of (A), and (F) is an AB sectional view of (A).
In this example, the eight thin tubes 35a to 35h and the three-way valves 37a to 37h of Example 4 are formed on a glass substrate.

The glass chip 51 has a five-layer structure, and is formed by forming a flow path by etching with hydrofluoric acid or the like on the substrate p4 and attaching the substrates p3 and p5 on the upper and lower sides thereof. A substrate p1 and a substrate p2 are attached to the upper surface of the substrate p3.
As shown in (C), the crossing portion 52 where the flow paths intersect has a hole 53 in the substrate p3 which is the center of the five layers, and the flow path of the substrate p2 and the flow path of the substrate p4 on both sides thereof. It is supposed to be connected.

A block (valve) 54 spans between the two flow paths and functions as a flow path switching mechanism.
The material of the block may be glass of the same material as that forming the flow path, but because of the sliding motion, a material having a lower coefficient of friction and a different hardness has better sliding characteristics. For example, a fluororesin is preferably used. In the case of a glass material, a fine block can be produced by hydrofluoric acid etching and polishing techniques, and for a fluororesin or the like, this block can be produced by cutting a thin film having the same thickness with a laser. The operation of installing this block on the glass chip can be done by human operation with a microscope and tweezers, but in mass production, it is set by robot operation with a micromanipulator applying microelectronic device fabrication technology.

  The substrate p1 is a glass substrate that covers the substrate p2. The size of the glass chip 51 is, for example, a rectangle of 3.8 mm × 6.0 mm, and the overall thickness is 0.85 mm. The thickness of the substrate p1 is 0.35 mm, the thickness of the substrate p2 is 0.1 mm, the thickness of the substrate p3 is 0.15 mm, the thickness of the substrate p4 is 0.1 mm, and the thickness of the substrate p5 is 0.15 mm. The channel width of the AB cross section is 0.05 mm.

Next, the operation of this embodiment will be described.
The liquid from which bubbles are to be removed passes through the glass chip 51 from the inlet 55 under pressure.
The glass chip 51 is formed with a narrow flow path by an etching technique, and each flow path is provided with a function (block 54) corresponding to the three-way valve of the fourth embodiment. 56 or 57 is selectively removed or recovered.
When the size of bubbles and fine particles to be removed is smaller, the configuration of Example 4 may limit the removal, but in Example 5, the flow path is expanded from the micron order to the nanometer size. Therefore, it is possible to cope with the case where the size of the fine particles is small.

  FIG. 8 is an example in which the tubes 20b, 20a, and 43 used in the third embodiment are attached to the IN side and the OUT side of the glass chip 51 described in the fifth embodiment. A glass chip 51 is installed in the frame of the metal body 61, and is sandwiched between the joints 21, 19a, 19b, thereby realizing a liquid seal. The camera image area at this time is a rectangle of 3.1 mm × 5.1 mm. The tube size is 0.5 mm in outer diameter and 0.3 mm in inner diameter on both the IN side and the OUT side.

  As shown in FIG. 7F, a block 54 is inserted between the substrate p5 and the substrate p4 at a place corresponding to the three-way valve in the flow path. Since the block 54 is moved in the direction of the arrow by the piezoelectric element 58, the block 54 opens and closes the flow path and serves as a three-way valve. (F) 56 is a member for fixing the piezoelectric element 58 to the glass chip 51.

  Bonding between the block 54 and the piezoelectric element 58 may be physical bonding, or one may be a magnet and the other may be a material sensitive to magnetic force. In this example, a piezoelectric element is used to move the block. However, the piezoelectric element 58 is formed of a shape memory alloy, and the temperature is changed by energizing a portion corresponding to the heater at a nearby point, and the element moves in the direction of the arrow. You may make it make it.

[Example 6]
Next, still another embodiment of the present invention will be described.
FIG. 9 is a modification of the glass chip 51 shown in Example 5, (A) is a top view, and (B) is a cross-sectional view taken along AB in (A).
In the sixth embodiment and the fifth embodiment, the block 54 as the flow path switching mechanism is different, but the other flow path configurations are the same.

  In this embodiment, an LED (light emitting diode) 63 is provided adjacent to the block 54 serving as a valve, and the opening / closing of the flow path is driven by turning on / off the LED. Further, the block 54 may be moved by the pressure of light instead of the LED, or another groove is formed on the substrate p5, and the pressure of a medium such as air or an appropriate liquid is applied thereto, A mechanism for moving the block 54 in a piston motion may be used.

[Example 7]
Next, still another embodiment of the present invention will be described.
FIG. 10 shows a modification of the glass chip 51 shown in the fifth embodiment and shows a top view.
This is a case where the piezoelectric element actuator 65 (65a, 65b) is used as a valve of the flow path switching mechanism, and a PZT actuator is used. This PZT (Lead zirconate titanate) is the most common piezoelectric element, and is an oxide of Pb, Zr, and Ti, and is called PZT from the beginning. An actuator using the piezoelectric element is called a PZT actuator.
In this case, PZT is embedded in a predetermined portion of the glass substrate, or PZT is formed on the substrate p4 by vapor deposition, and wiring for applying a voltage is formed. For these, a manufacturing technique in the field of semiconductor device manufacturing can be used. The valve functions by narrowing and closing the flow path due to the distortion of the PZT. In this case, both the bubble side channel 67 and the bubbleless channel 69 can be closed.

  The presence / absence of bubbles, the position of bubbles, and their velocity are measured by the camera information by the camera information, whereby the opening / closing timing of the valve is adjusted, and the bubbles are transferred to the bubble liquid channel (particle-containing channel) 67, A liquid-only fluid is cut into a bubble-free channel (particle-free channel) 69. Although the timing is controlled by a computer, it has a function of maintaining learning ability and opening and closing at an optimal timing. However, even if the bubbles are separated in the optimal control state of the computer, the control may be erroneously performed and bubbles may enter the bubble-free channel 69.

  In that case, in the case of FIG. 10, both valves (piezoelectric element actuators 65a and 65b) are closed so that the pattern portion is not used for a while. In case of trouble, a predetermined alarm is also issued. In this example, four branch patterns are formed on one glass plate, but hundreds or thousands of patterns can be formed. In such a case, a pattern in which air bubbles enter by mistake closes both valves and kills the function. After the number exceeds a set value, an alarm is issued and an initial return operation of this device is promoted. Can also be built.

What is important in the above example is (1) Since all the flow paths are monitored by the camera, at least the substrates p1, p2, p3, p4 and the cell 15 are observed so that the presence of bubbles and fine particles can be seen by the camera. Since the material is selected so as to be transparent at the wavelength of the camera measurement, and (2) the cost is reduced and the system is simple, monitoring is performed with one camera as much as possible. It is preferable to be formed.
In the above embodiment, a visible light camera is assumed, but a silicon substrate may be used instead of the glass plate. In that case, since it becomes transparent in the infrared region, an infrared camera is used as the camera.

As in the present invention, in order to collect only the fluid while avoiding the particles in the fluid or to selectively collect the fine particles, two steps of techniques are required. The first is a reliable method for detecting fine particles, and the second is a method for reliably avoiding or collecting the fine particles. When the fluid is a liquid, the fine particles include bubbles.
The former method is configured by simultaneously measuring the presence / absence of bubbles and fine particles, their positions, and their velocities using a camera as a sensor.
Further, the removal technique is configured by using one of two techniques.

  The first is a method in which only a liquid or gas is sucked by moving a thin suction nozzle to avoid bubbles, fine particles and fine particles in a gas. Further, when collecting specific fine particles and bubbles selectively, the suction nozzle is quickly moved to a place where it exists and is collected by suction. The suction nozzle is automatically moved by computer control based on the camera image data. Since the bubbles and fine particles have a micron order size, the size of the suction nozzle, the moving distance of the suction nozzle, and the control accuracy are also in the micron order, and the camera image becomes a microscopic image.

  Secondly, the liquid can be passed through multiple thin transparent tubes or channels, and data can be acquired with a camera, and it can be sequentially determined from the image data which tube or bubble has been sucked. It is to be. Each tube or channel has a three-way valve. By opening and closing the three-way valve of the tube that has taken in bubbles and particles, the bubbles and particles flow to another channel. In one channel, only liquid (only gas in the case of a gaseous medium) is used. Since bubbles and fine particles are of micron order size, tubes and channels are made by micromachine technology and semiconductor manufacturing etching technology, valves are also fine size, and their control is also light, sound waves, etc. It uses micromachine technology that makes full use of.

Moreover, since this invention can be applied to the following technical fields, they are listed.
(1) Bubble removal for separation of monomer in liquid discharge and solvent in coating (precision coating) process, (2) Bubble removal for improving accuracy of water for analyzer, (3) Polisher in CMP process Bubble removal to reduce load, (4) Bubble removal in emulsion coating in screen printing process, (5) Printing ink bubble removal in screen printing process, (6) Ink bubble removal in inkjet printing, (7) Paint And bubble removal with printing inks, especially water-based materials, (8) Bubble removal to improve mill efficiency in the manufacturing process using a mill, (9) Bubble removal to improve accuracy in viscosity measurement, (10) Coating Removal of bubbles to improve efficiency during liquid production / filling, (11) Removal of bubbles in the pulp and paper industries, (12) Removal of bubbles in a size press process for surface treatment of paper, 3) Bubble removal in chemical dyeing in padding dyeing and resin processing of rubber and latex, (14) Bubble removal in adhesive production and coating / antifreeze production management, (15) Bubbles in oil refining and boilers Removal, (16) cleaning and removal of bubbles in washing tub, (17) removal of bubbles in other industrial wastewater, (18) removal of bubbles to prevent corrosion of pipes in wastewater treatment, (19) floating in the atmosphere and liquid (20) Removal of bubbles for rust prevention at the time of cleaning / cutting in metal processing, (21) Removal of foreign matters for countermeasures against defects at the time of cleaning / cutting in metal processing, ( 22) Removal of bubbles in the abolition process such as food processing, (23) Removal of bubbles in the fermentation process of food processing, (24) Removal of hair (100 μm) of fruit juice and liquid food, removal of sand foreign matter and bubbles, (25) Fruit Removal of bubbles for quality stability, bacteria extraction and removal in juice and other liquid foods, (26) Removal of bubbles in fats and oils during food processing, (27) Removal of giant bubbles in cosmetic products, (28) Cosmetic products Removal of bubbles for efficiency and uniformity in filling (29) Removal of bubbles in the production of amino acids and antibiotics, (30) Removal of bubbles in fuel cells, (31) Removal of bubbles in resist coating in semiconductor and FPD manufacturing processes .

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic explaining one Example of this invention, (A) is a whole block diagram of a fine particle sorter, (B) is sectional drawing in a part (cell part) of (A), (C) and (D ) Is an enlarged cross-sectional view of the portion b (nozzle tip portion) of (B), (C) is a diagram showing the advancing path of the bubble with an arrow, and (D) explains the operation of moving the nozzle while avoiding the bubble. FIG. (A) is a map in which the position of the bubble in the nozzle scanning line is predicted after time Δt at time t0, and (B) shows a curve as the trajectory of the nozzle tip when bubbles 1 to 4 exist. This is an example of creation, and (C) is a diagram in which a new bubble 5 is generated and a curve considering it is created at that time. It is the figure which showed the other example of the track | orbit of a nozzle tip. (A) is chrysanthemum, (B) is mimosa, and (C) is an electron micrograph of nerine. It is the schematic which shows another Example, (A) is a whole block diagram, (B) is an expanded sectional view in the b part of (A). It is the schematic which shows another Example, (A) is a whole block diagram of a fine particle sorter, (B) is an expanded sectional view in a part of (A). BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic of a chip | tip type | mold particle | grain sorting apparatus, (A) is a top view, (B) is the left view of (A), (C) is EF sectional drawing of (A), (D) is a right view. , (E) is a CD sectional view, and (F) is an AB sectional view. This is an example in which the tube used in Example 3 is attached to the glass chip 51 described in the same example. It is a modification of the glass chip | tip 51 shown in Example 5, (A) is a top view, (B) is sectional drawing in AB of (A). It is a modification of the glass chip 51 shown in Example 5. FIG.

Explanation of symbols

11 Tank 13, 14 Pump 15 Cell 17 Nozzle 19, 21 Fitting 23 Actuator 25 Coil 27 Magnet 29 Packing 31 Tube 33 Piezoelectric Element

Claims (14)

A flow path through which fluid flows;
A particle monitoring mechanism for predicting a traveling path of particles in the fluid;
A fine particle sorting mechanism for selectively collecting the fine particles based on prediction by the fine particle monitoring mechanism, or selectively collecting a fluid while avoiding the fine particles;
A device for sorting fine particles in a fluid.   The fine particle sorting apparatus according to claim 1, wherein the fluid is a liquid, and bubbles are included as the fine particles.   The fine particle sorting apparatus according to claim 1, wherein the fluid is a gas. The fine particle sorting device is a device for selectively collecting a fluid,
The fine particle sorting mechanism includes: a nozzle mechanism that sucks fluid from a fixed tip portion; and a fluid movement mechanism that causes displacement of the fluid around the tip portion to move to a position where the fine particle is not sucked by the nozzle mechanism. The fine particle sorting apparatus according to any one of claims 1 to 3.   The fine particle sorting apparatus according to claim 4, wherein the displacement for moving the fine particles by the fluid moving mechanism is caused by a liquid flow or an air flow.   The fluid moving mechanism is a method of applying a fluid by any one of a method of applying an electric field or a magnetic field, a method of generating a sound wave by a piezoelectric element, and a method of deforming a shape memory alloy by heating or cooling by a heater or a Peltier element. 6. The fine particle sorting apparatus according to claim 4, wherein the fine particle sorting apparatus is a moving mechanism.   7. The fine particle sorting mechanism includes a nozzle mechanism that sucks fluid from a tip portion and is supported so that the tip portion can move, and a nozzle drive mechanism that drives movement of the nozzle mechanism. The fine particle sorter according to any one of the above.   8. The fine particle sorting apparatus according to claim 7, wherein the nozzle driving mechanism drives movement of the nozzle mechanism by an actuator based on any one of a piezoelectric element, an electromagnetic solenoid, static electricity, a shape memory alloy, air pressure, and liquid pressure. A plurality of branch channels branched from the channel through which the fluid flows;
A fine particle monitoring mechanism for monitoring the presence or absence of fine particles in the fluid of each branch channel;
A fine particle-containing flow path that is formed by merging each of the flow paths branched into two each of the branch flow paths;
A fine particle-free flow path that joins the other flow paths from the branch flow paths into a single flow path;
A flow path switching mechanism that is provided at each branch point of each branch flow path and performs flow path switching based on monitoring by the fine particle monitoring mechanism;
A device for sorting fine particles in a fluid.   The fine particle sorting apparatus according to claim 9, wherein each flow path and the flow path switching mechanism are formed on a common substrate by microfabrication. The flow path is a groove formed in the microchip by an etching technique,
The flow path switching mechanism is formed by an etching technique, serves as a valve and a valve seat, and is opened and closed by using any one of magnetism, static electricity, sound waves, and light waves. Fine particle sorter.   9. The particulate monitoring mechanism includes an imaging device that captures the position of the particulate in the channel over time, and an arithmetic unit that calculates a traveling path of the particulate based on the imaging result. The fine particle sorting apparatus according to one item.   The fine particle sorting apparatus according to claim 12, wherein the imaging device is adjusted so that a depth of field is longer than a depth of the flow path.   The computing means is such that the depth of field is adjusted to be shorter than the depth of the flow path, and the traveling path of the fine particles is calculated three-dimensionally based on image information obtained from the imaging device. Item 13. The fine particle sorting apparatus according to Item 12.

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