WO2020050234A1

WO2020050234A1 - Capillary and pipette

Info

Publication number: WO2020050234A1
Application number: PCT/JP2019/034510
Authority: WO
Inventors: 東別府　誠; 宮里　健太郎; 松下　哲也
Original assignee: 京セラ株式会社
Priority date: 2018-09-03
Filing date: 2019-09-03
Publication date: 2020-03-12
Also published as: JP7154303B2; JPWO2020050234A1

Abstract

This capillary is configured so that a first end and a second end, which are both ends thereof in the lengthwise direction, are open. The capillary includes a first hole and a second hole. The second hole is linked to the second end side of the first hole. The water-repelling properties of the inner surface of the second hole are different from the water-repelling properties of the inner surface of the first hole.

Description

Capillaries and pipettes

The present disclosure relates to capillaries and pipettes.

2. Description of the Related Art There is known a pipette that drives a pump action device to generate a negative pressure inside a capillary and sucks a liquid into the capillary. As such a pipette, there is also known a pipette in which a liquid inside a capillary is reciprocated in a longitudinal direction of the capillary and then agitated and mixed with the liquid after sucking a plurality of kinds of liquids (for example, Patent Document 1). And Patent Document 2).

JP-A-10-62437 JP-A-2000-304754

は In the capillary according to an aspect of the present disclosure, the first end and the second end, which are both ends in the length direction, are open. The capillary has a first hole and a second hole connected to the second end of the first hole. The water repellency of the inner surface of the second hole is different from the water repellency of the inner surface of the first hole.

A pipette according to one embodiment of the present disclosure controls the capillary, a pressure chamber communicating with the inside of the capillary via the second end, a driving unit that changes the volume of the pressure chamber, and controlling the driving unit. And a control unit that performs the control. The capillary has a first pipe located on the first end side and a second pipe located on the second end side. The first pipe portion has the first hole penetrating in a length direction. The second pipe portion has the second hole penetrating in a length direction. The control unit controls the drive unit so that the volume of the pressure chamber repeatedly increases and decreases, whereby at least a part of the liquid in the capillary reciprocates over the boundary between the first hole and the second hole. Control.

FIG. 2 is a cross-sectional view schematically illustrating a specific example of the pipette of the present disclosure. FIG. 2 is a cross-sectional view schematically illustrating a specific example of a capillary in the pipette of the present disclosure. FIG. 3 is a partially enlarged view of FIG. 2. 5 is a graph schematically illustrating an example of a change in voltage of a signal output by a first control unit. 5 (a), 5 (b), 5 (c), 5 (d), 5 (e) and 5 (f) are diagrams schematically showing the operation of the pipette of the present disclosure. . FIGS. 6A and 6B are schematic diagrams for explaining a modified example of the pipette and other modified examples. FIG. 4 is a diagram showing the effect of the outer diameter of the capillary tip on the amount of attached droplets. 8 is a table showing various conditions when FIG. 7 is obtained. FIG. 4 is a diagram illustrating an effect of an inner diameter of a capillary tip on a liquid suction amount.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The drawings used in the following description are schematic, and the dimensional ratios and the like in the drawings do not always match actual ones. Even in a plurality of drawings showing the same member, dimensional ratios and the like may not match each other in order to exaggerate shapes and the like.

において In the present disclosure, the term “water repellency” or “hydrophilicity” is sometimes used for both absolute and relative evaluation of properties.

For example, “having water repellency” indicates that the contact angle of the liquid to be aspirated by the pipette is 90 ° or more (absolute evaluation). Also, for example, “having hydrophilicity” indicates that the contact angle of the liquid to be aspirated by the pipette is less than 90 °. If the liquid to be suctioned by the pipette is not specified, the presence or absence of water repellency or hydrophilicity may be determined using the contact angle of water.

On the other hand, for example, “high water repellency”, “low water repellency”, or “different water repellency” means that two members touching a liquid to be sucked by a pipette (which may be water as described above). When the contact angles of the liquids are compared with each other, it means that one contact angle is larger, smaller, or different (relative evaluation) than the other contact angle. Therefore, for example, when the water repellency of the first member is higher than the water repellency of the second member, both the first member and the second member or the second member need not have the water repellency, It may have hydrophilicity.

[Outline of pipette]
FIG. 1 is a cross-sectional view schematically illustrating a configuration of a pipette 1 according to an embodiment of the present disclosure. In the drawings, the pipette 1 is given a fixed rectangular coordinate system xy for convenience. The + x side (the lower side in the drawing) is a side which is set lower when the liquid is sucked by the pipette 1.

The pipette 1 includes, for example, the capillary 10, a pipette body 20 that changes the air pressure in the capillary 10, and a first control unit 24 and a second control unit 25 that control the operation of the pipette body 20.

The inside of the capillary 10 is evacuated (depressurized) from the rear end (second end 12) of the capillary 10 by the pipette body 20 in a state where the tip (first end 11) on the + x side of the capillary 10 is in contact with the liquid. Liquid is drawn into the capillary 10. By sequentially performing the suction on a plurality of types of liquids, a plurality of types of liquids are stored in the capillary 10. Thereafter, when the exhaust and the air supply (decompression and increase in pressure in the capillary 10) are repeated from the second end 12 to the capillary 10 by the pipette body 20, a plurality of types of liquids flow in the capillary 10 in the length direction. Reciprocate (vibrate) along. Thereby, the plurality of types of liquids are stirred and, consequently, mixed.

[Capillary (Overview)]
The capillary 10 has a cylindrical shape in which the first end 11 and the second end 12 which are both ends in the length direction (x direction) are open. The “cylindrical shape” means a shape that is long in one direction (the length in one direction is longer than the length in other directions), hollow, and open at both ends. And does not mean only a cylindrical shape.

概略 The schematic shape of the capillary 10 may be various shapes. For example, in a cross section of the capillary 10 (a cross section orthogonal to the length direction; the same applies hereinafter), the shape of the inner edge (the inner surface of the capillary 10) and / or the outer edge (the outer surface of the capillary 10) is circular, elliptical, or oval. Alternatively, it may be a polygon or the like. Further, for example, the shape and / or size of the cross section (the inner edge and / or the outer edge) may be constant over the entire length of the capillary 10 or at least a part of the entire length of the capillary 10 in the length direction. It may be different depending on the position. Further, for example, in the cross section of the capillary 10, the inner edge and the outer edge may be similar to each other, or may not be similar. In addition, for example, the center line of the internal space (flow path) of the capillary 10 may extend linearly from the first end 11 to the second end 12, or may be bent at least in part.

In the description of the present embodiment, for the sake of convenience, the cross section (the inner edge and the outer edge) of the capillary 10 is assumed to be circular at any position in the length direction. In this case, the shape of the cross section of the hole of the capillary 10 is the same or similar (congruent) at different positions in the longitudinal direction of the capillary 10. When the inner diameters of the capillaries 10 at different positions in the longitudinal direction are different from each other, the cross-sectional area of the cross-sectional area of the holes at any of the different positions is similar or different. It may be taken to mean different from each other.

The dimensions of the capillary 10 may be appropriately set according to various circumstances such as the amount of the liquid to be collected and / or a method of attaching the capillary 10 to the pipette body 20. For example, the inner diameter of the capillary 10 may be 0.1 mm or more and 0.3 mm or less. Further, for example, the outer diameter of the capillary 10 may be 0.4 mm or more and 1.2 mm or less. Further, for example, the length of the capillary 10 may be 20 mm or more and 100 mm or less. Of course, dimensions outside the above range may be employed. In the following description, the outside diameter D1 and inside diameter D2 (see FIG. 2) at the first end 11 of the capillary 10 will be exemplified by values outside the above range (FIGS. 7 to 9). Needless to say, the outer diameter D1 and the inner diameter D2 may be within the above range.

材料 The material of the capillary 10 may be various. For example, examples of the material include glass, resin, ceramics, and metal. Examples of the resin include polypropylene, polyethylene, and polytetrafluoroethylene. Further, for example, in the capillary 10, a part in the length direction and another part may be made of different materials, and / or a part in the radial direction and another part may be made of materials different from each other. May be. Further, for example, the capillary 10 may be configured by forming a film made of another material on at least a part of the surface of a member made of one material. Further, for example, at least a part (that is, a part or the whole) of the capillary 10 may be made of a light-transmitting material (eg, resin or glass).

少なくとも At least a part (that is, part or all) of the surface of the capillary 10 may have water repellency. The area having the water repellency on the surface of the capillary 10 may be appropriately set. For example, the region having water repellency includes the end surface of the first end 11 (the surface facing in the + x direction), a part of the inner surface of the capillary 10 on the + x side, and a part of the outer surface of the capillary 10 on the + x side. In. In other words, the region having water repellency includes a region that comes into contact with the liquid. Since the area in contact with the liquid has water repellency, for example, the risk of liquid adhesion and / or unintentional movement is reduced, and the accuracy of the liquid collection amount is improved.

The capillary 10 (part or all) may have water repellency on the surface by being made of a material having water repellency, for example. Further, for example, the capillary 10 (part or all) may have water repellency by forming a water repellent film on the surface of a member made of a material having no water repellency.

As the water-repellent film, various types may be used, and examples thereof include a water-repellent film formed by a silane coupling agent, a metal alkoxide-containing water-repellent film, a silicone-containing water-repellent film, and a fluorine-containing water-repellent film. Can be. Various methods may be used as a method for forming the water-repellent film on the surface of the capillary 10, for example, a dry process method or a wet process method may be used. Examples of the dry process method include a physical vapor deposition method and a chemical vapor deposition method. Examples of the former include a physical vapor deposition method and a sputtering method. Examples of the latter include a chemical vapor deposition (CVD) method and an atomic layer deposition (ALD) method. Examples of the wet process method include a sol-gel method, a dip coating method, and a coating method.

The capillary 10 is, for example, disposable and detachable from the pipette body 20. The attachment / detachment method may be an appropriate method. For example, the capillary 10 may be fixed by being pressed into a hole of the pipette body 20, or may be fixed by fastening or locking by a mechanism (not shown) provided in the pipette body 20. However, the capillary 10 may be used repeatedly, or may be fixed (for example, adhered) to the pipette body 20 in a non-detachable manner.

[Pipette body]
The pipette body 20 has a pressure chamber 21 (cavity) communicating with the inside of the capillary 10. The pipette body 20 reduces the pressure (exhaust) in the capillary 10 by increasing the volume of the pressure chamber 21 and increases the pressure (air supply) in the capillary 10 by decreasing the volume of the pressure chamber 21. Do. Thereby, for example, suction and discharge of liquid by the capillary 10 are realized. The configuration of the pipette body 20 that realizes such an operation may be an appropriate one. An example is shown below.

The pipette body 20 includes, for example, a flow path member 35 that forms a flow path (including the pressure chamber 21) communicating with the inside of the capillary 10, an actuator 40 that changes the volume of the pressure chamber 21, and a flow path member. And a valve 23 for permitting and prohibiting communication between the inside (flow path) of 35 and the outside.

(Flow path member)
The general outer shape and size of the flow path member 35 may be formed in an appropriate shape. In the illustrated example, the schematic outer shape of the flow path member 35 has an axial shape (a shape in which the length in the x direction is longer than the length in other directions) in series with the capillary 10. The size is, for example, a size that the user can pinch or grip (for example, the maximum outer diameter is 50 mm or less).

The internal space of the flow path member 35 connects, for example, the above-described pressure chamber 21, the communication flow path 27 connecting the capillary 10 and the pressure chamber 21, and the communication flow path (in another aspect, the pressure chamber 21) to the outside. And an open channel 28.

形状 The shape, position, size, and the like of the pressure chamber 21 may be set as appropriate. In the illustrated example, the pressure chamber 21 is located on a side surface of the flow path member 35. Further, for example, the schematic shape of the pressure chamber 21 is a thin shape having a substantially constant thickness with the direction (the y direction) overlapping the actuator 40 being the thickness direction. Here, the thin shape is a shape in which the length in the y direction is shorter than the maximum length in each direction orthogonal to the y direction. The planar shape (the shape viewed in the y direction) of the pressure chamber 21 may be an appropriate shape such as a circle, an ellipse, a rectangle, or a rhombus. The thickness (y direction) of the pressure chamber 21 is, for example, not less than 50 μm and not more than 5 mm. The diameter of the pressure chamber 21 (the maximum length in each direction orthogonal to the y direction) is, for example, 2 mm or more and 50 mm or less.

形状 The shapes, positions, sizes, and the like of the communication flow path 27 and the open flow path 28 may be appropriately set. For example, the flow path member 35 includes a first flow path 22 extending from the capillary 10 in the length direction (x direction) of the capillary 10 and a direction intersecting the first flow path 22 from the middle of the first flow path 22. And a second flow path 26 extending to the pressure chamber 21. A communication channel 27 is formed by the second channel 26 and a portion of the first channel 22 on the capillary 10 side from the connection position with the second channel 26. With such a flow path configuration, for example, the danger that the sucked liquid (for example, its splash) enters the pressure chamber 21 and adheres to the actuator 40 is reduced. As a result, the possibility that the operating characteristics of the actuator 40 change due to the attached liquid is reduced.

The first flow path 22 communicates with the outside of the flow path member 35, for example, on the side opposite to the capillary 10. An open channel 28 is formed by a portion of the first channel 22 opposite to the capillary 10 from a position connected to the second channel 26. Therefore, the flow path for releasing the liquid so that the liquid does not enter the pressure chamber 21 is also used as the open flow path 28 for opening the pressure chamber 21 to the outside, and the space efficiency is improved.

形状 The shapes and dimensions of the cross sections of the first flow path 22 and the second flow path 26 may be appropriately set. For example, the cross section of the first flow path 22 and the second flow path 26 is a circle having a diameter of 0.1 mm or more and 1 mm or less. Further, the inner diameters of the first flow path 22 and the second flow path 26 may be the same or different from each other. The shape and size of the cross section of the first flow path 22 and / or the second flow path 26 may be constant in the length direction or may be changed.

The flow path member 35 may be configured by combining members of an appropriate shape made of an appropriate material. In the illustrated example, the flow path member 35 has a first part 30 and a second part 60 joined to each other. The first part 30 has a through hole serving as the pressure chamber 21. The second part 60 has a first flow path 22 and a second flow path 26. The pressure chamber 21 is configured by a space surrounded by the first part 30, the second part 60, and the actuator 40. In addition, each of the first part 30 and the second part 60 may be configured by a combination of a plurality of members. The material of the first part 30 and the second part 60 may be, for example, metal, ceramic, resin, or any combination thereof.

(Actuator)
The actuator 40 constitutes, for example, one of the inner surfaces of the pressure chamber 21. Specifically, for example, the actuator 40 has a substantially plate shape, and is joined to the first part 30 so as to close the through hole of the first part 30 from the side opposite to the second part 60, and the communication passage 27 constitutes the inner surface on the opposite side to the inner surface where it opens. Then, the actuator 40 reduces the volume of the pressure chamber 21 by bending toward the pressure chamber 21 side (in other words, by displacing the inner surface of the pressure chamber 21 inward). Conversely, the actuator 40 increases the volume of the pressure chamber 21 by bending to the opposite side to the pressure chamber 21 (in other words, by displacing the inner surface of the pressure chamber 21 outward).

The specific configuration of the actuator 40 that causes the above-described bending deformation may be appropriately determined. For example, the actuator 40 is configured by a unimorph type piezoelectric element. More specifically, for example, the actuator 40 has two stacked piezoelectric

ceramic layers

40a and 40b. Further, the actuator 40 has an internal electrode 42 and a surface electrode 44 facing each other with the piezoelectric ceramic layer 40a interposed therebetween. The piezoelectric ceramic layer 40a is polarized in the thickness direction.

Then, when a voltage is applied to the piezoelectric ceramic layer 40a in the same direction as the polarization direction by the internal electrode 42 and the surface electrode 44, the piezoelectric ceramic layer 40a contracts in the plane direction. On the other hand, the piezoelectric ceramic layer 40b does not cause such shrinkage. As a result, the piezoelectric ceramic layer 40a bends toward the piezoelectric ceramic layer 40b. That is, the actuator 40 bends toward the pressure chamber 21. When a voltage in the opposite direction is applied, the actuator 40 bends to the side opposite to the pressure chamber 21.

(4) The shape and size of the actuator 40 may be appropriately set. For example, the actuator 40 is a flat plate having an appropriate planar shape. The planar shape may or may not be similar to the planar shape of the pressure chamber 21. The maximum length in each direction in plan view (when viewed in the y direction) is, for example, 3 mm or more and 100 mm or less. The thickness (y direction) of the actuator 40 is, for example, not less than 20 μm and not more than 2 mm. The materials, dimensions, shapes, conduction methods, and the like of various members constituting the actuator 40 may be appropriately set. An example is shown below.

The thickness of the piezoelectric

ceramic layers

40a and 40b may be, for example, not less than 10 μm and not more than 30 μm. The material of the piezoelectric

ceramic layers

40a and 40b may be, for example, a ferroelectric ceramic material. Such ceramic materials include lead zirconate titanate (PZT), NaNbO ₃ system, KNaNbO ₃ system, BaTiO ₃ system and (BiNa) NbO ₃ system, those BiNaNb ₅ O ₁₅ system. The piezoelectric ceramic layer 40b may be made of a material other than the piezoelectric material.

(4) The internal electrode 42 is located, for example, between the piezoelectric ceramic layer 40a and the piezoelectric ceramic layer 40b, and has substantially the same size as the actuator 40. The thickness of the internal electrode 42 may be, for example, 1 μm or more and 3 μm or less. The internal electrode 42 is externally conductive, for example, by a through electrode 48 penetrating the piezoelectric ceramic layer 40a and a connection electrode 46 located on the surface of the actuator 40 and connected to the through electrode 48.

The surface electrode 44 is located, for example, on the opposite side of the piezoelectric ceramic layer 40a from the piezoelectric ceramic layer 40b (outside of the pressure chamber 21), and has a surface electrode main body 44a and an extraction electrode 44b. The surface electrode main body 44a has, for example, a planar shape substantially equal to the pressure chamber 21, and is provided so as to overlap the pressure chamber 21 in the thickness direction. The extraction electrode 44b is formed so as to be extracted from the surface electrode main body 44a. The thickness of the surface electrode 44 may be, for example, 0.1 μm or more and 1 μm or less.

The materials of the internal electrode 42, the surface electrode 44, the connection electrode 46, and the through electrode 48 may be, for example, a metal material. More specifically, for example, the material of the internal electrode 42 and the through electrode 48 may be Ag-Pd. The material of the surface electrode 44 and the connection electrode 46 may be, for example, Au.

The actuator 40 or a part of the actuator 40 (for example, a part overlapping the surface electrode main body 44a) may be referred to as a driving unit 50. The actuator is not limited to a unimorph type piezoelectric element. For example, the actuator may be a bimorph-type piezoelectric element or an electrostatic actuator.

(valve)
The valve 23 is provided, for example, at a position where the open channel 28 communicates with the outside. By opening and closing the valve 23, communication between the inside and the outside of the flow path member 35 is permitted or prohibited. In the state where the communication is prohibited, the pressure in the capillary 10 is reduced and increased by the change in the volume of the pressure chamber 21. On the other hand, in a state where the communication is permitted, even if the volume of the pressure chamber 21 is changed, the pressure in the capillary 10 is not reduced or increased. An example of the use of the function in which the pressure is not reduced or increased will be described later.

The valve 23 opens and closes in response to, for example, a signal input from the outside. As the valve 23, various valves such as an electromagnetic valve or a piezoelectric valve can be used. The valve 23 may be closed when a signal is not input, and may be opened when a signal is input. Alternatively, the valve 23 may be opened when a signal is not input, and may be opened when a signal is input. The signal may be in a closed state, or a signal for closing and a signal for opening may be input.

[Control unit]
The first control unit 24 is electrically connected to the actuator 40, and changes the volume of the pressure chamber 21 by applying an electric signal to the actuator 40 to deform the actuator 40. Thus, it is possible to perform suction of the liquid into the capillary 10, discharge of the liquid from the capillary 10, and the like. By driving the actuator 40 so that the volume of the pressure chamber 21 periodically increases and decreases, the liquid sucked into the capillary 10 can be mixed by vibrating.

The second control unit 25 is electrically connected to the valve 23, and opens and closes the valve 23 by giving an electric signal to the valve 23. When the liquid has flowed into the first flow path 22, the liquid can be discharged from the valve 23 to the outside by opening the valve 23. Also, after the actuator 40 is deformed and the liquid is sucked in, the valve 23 is opened, the deformation of the actuator 40 is returned to the original state in that state, and the actuator 40 is deformed again after the valve 23 is closed. Liquid can be inhaled.

The first control unit 24 and the second control unit 25 can be configured using various integrated circuits. The first control unit 24 and the second control unit 25 may be configured by separate ICs (Integrated @ Circuit), may be synchronized, or may be partially or wholly integrated in the same IC. The first control unit 24 and / or the second control unit 25 may be fixedly provided on the pipette main body 20, may be provided so as to be relatively movable with respect to the pipette main body 20, or may be partially provided. A (for example, a driver) may be fixedly provided on the pipette body 20, and another part (for example, a part for outputting a command to the driver) may be provided so as to be relatively movable with respect to the pipette body 20.

[Capillary (details)]
FIG. 2 is an enlarged sectional view showing the capillary 10. FIG. 3 is a partially enlarged view of FIG.
The capillary 10 has a first pipe part 17 located on the first end 11 side and a second pipe part 18 located on the second end 12 side. The first pipe part 17 has a first hole 10a penetrating in the length direction, and the second pipe part 18 has a second hole 10b penetrating in the length direction. The second hole 10b is connected to the second end 12 of the first hole 10a. The first tube portion 17 is a portion of the capillary 10 having the first hole 10a, and the second tube portion 18 is a portion of the capillary 10 having the second hole 10b. The first pipe part 17 and the second pipe part 18 may be two parts of one integrally formed member (that is, they may not be separate members) or may be two members fixed to each other. You may.

(Water repellency)
The water repellency of the inner surface of the first hole 10a is different from the water repellency of the inner surface of the second hole 10b. That is, the capillary 10 has the first hole 10a and the second hole 10b whose inner surfaces have different water repellency. Thus, for example, when the liquid flows through the boundary 14 between the two, the flow of the liquid is likely to be disturbed due to the difference in water repellency. As a result, for example, when the actuator 40 is driven so that the liquid repeatedly reciprocates beyond the boundary 14, the liquid is easily mixed. In the following description, the water repellency of the inner surface of the first hole 10a may be abbreviated to the water repellency of the first hole 10a. The same applies to the second hole 10b.

水性 Either of the first hole 10a and the second hole 10b may have higher water repellency than the other. In the present embodiment, a case where the water repellency of the first hole 10a is higher than the water repellency of the second hole 10b is taken as an example. That is, in the present embodiment, the contact angle of the first hole 10a is larger than the contact angle of the second hole 10b.

When the water repellency of the first hole 10a is higher than the water repellency of the second hole 10b, both the first hole 10a and the second hole 10b may have water repellency (the contact angle is 90 ° or more). The first hole 10a may have water repellency and the second hole 10b may have hydrophilicity, or both the first hole 10a and the second hole 10b may have hydrophilicity. It may be. In the present embodiment, one of the above three aspects (an aspect in which at least the first hole 10a has water repellency) is taken as an example.

In each of the first hole 10a and the second hole 10b, the water repellency may be uniform or change in the length direction and / or the direction around the axis of the capillary 10. In the present embodiment, a uniform case is taken as an example. However, even if uniform, it goes without saying that there may be variations in water repellency due to processing errors. When the water repellency changes, the change may be continuous or discontinuous (stepwise). However, since the first hole 10a and the second hole 10b can define the boundary 14 from the viewpoint of the water repellency, the change in the water repellency between the two is discontinuous.

具体 The specific size of the contact angle between the first hole 10a and the second hole 10b may be appropriately set. For example, when the first hole 10a has water repellency (when the contact angle is 90 ° or more), the contact angle may be 90 ° or more and 95 ° or less (that is, a value close to 90 °). However, it may be 95 ° or more and 150 ° or less, or may be more than 150 °. Note that the angle exceeding 150 ° is a size that can be said to have so-called super water repellency. Further, when the second hole 10b has water repellency, the contact angle of the second hole 10b is 90 ° or more and 95 ° or less, and 95 ° or more and 150 ° as long as the contact angle is smaller than the contact angle of the first hole 10a. It may be less than or equal to 150 °. When the second hole 10b has hydrophilicity (when the contact angle is less than 90 °), the contact angle of the second hole 10b is 85 ° or more (ie, a value close to 90 °). May be 10 ° or more and 85 ° or less, or may be less than 10 °. In addition, less than 10 degrees is a size which can be said to have what is called superhydrophilicity.

The difference between the contact angle of the first hole 10a and the contact angle of the second hole 10b may be set as appropriate. For example, the difference between the two may be 5 ° or more, 10 ° or more, 30 ° or more, 90 ° or more, or 140 ° or more. In addition, as long as it does not contradict this lower limit, the difference between the two may be less than 180 °, 140 ° or less, 90 ° or less, 30 ° or less, or 10 ° or less (may be combined with any of the above lower limits. ). For example, the difference between the two may be 30 ° or more and 140 ° or less, or 30 ° or more and 90 ° or less. The larger the lower limit of the difference between the two is, for example, the stronger the effect of causing turbulence in the flow is. On the other hand, as the upper limit of the difference between the two increases, for example, the selection of the material becomes more difficult. Within the above range, the selection of the material is facilitated, for example, while obtaining the effect of causing turbulence in the flow.

(Hole shape, etc.)
The shapes and dimensions of the first hole 10a and the second hole 10b, the materials constituting these holes, and the like may be appropriately set. An example is shown below.

１The first hole 10a extends from the first end 11 to the boundary 14, for example. The second hole 10b extends from the boundary 14 to the second end 12, for example. Note that, unlike the example shown in the drawing, another hole (for example, a hole whose water repellency is equal to or less than the water repellency of the second hole 10 b) is formed from the boundary 14 to the first end 11, and / or the second from the boundary 14. It is also possible to configure another hole (for example, a hole whose water repellency is higher than the water repellency of the first hole 10a) up to the end 12.

The position of the boundary 14 may be an appropriate position between the first end 11 and the second end 12. For example, the boundary 14 is located on the first end 11 side with respect to the longitudinal center of the capillary 10. For example, the length of the first hole 10a is about 5% to 30% of the total length of the capillary 10.

The shape and / or size of the cross section of the first hole 10a and the shape and / or size of the cross section of the second hole 10b may be the same or different. When the two are different in size, either may be larger. In each of the first hole 10a and the second hole 10b, the shape and / or size of the cross section may or may not be constant in the length direction of the capillary 10.

では In the illustrated example, the cross section (inner diameter) of the first hole 10a is larger toward the second hole 10b. On the other hand, the cross section (inner diameter) of the second hole 10b is constant in the length direction of the capillary 10. At the boundary 14, the inner diameter of the first hole 10a is larger than the inner diameter of the second hole 10b.

具体 The specific size of the difference between the inner diameter of the first hole 10a and the inner diameter of the second hole 10b may be appropriately set. For example, at the boundary 14, the inner diameter of the first hole 10a is 1.1 times or more, 1.5 times or more, or 2 times or more, and 5 times or less, 3 times or less of the inner diameter of the second hole 10b. Or twice or less (the former example of the lower limit value and the latter example of the upper limit value may be combined as long as there is no contradiction). Further, for example, the difference between the inner diameter of the first hole 10a and the inner diameter of the second hole 10b is not less than の of the thickness of the second member 16 described later (the length in the radial direction from the inner surface to the outer surface), 2/3 or more or 1 time or more, and less than 2 times, 18/10 times or less or 2/5 or less (unless inconsistent with the former example of the lower limit and the latter example of the upper limit, May be combined.). Further, for example, the inclination angle of the inner surface of the first hole 10a with respect to the center line of the first hole 10a is 1 ° or more, 2 ° or more or 3 ° or more, and 15 ° or less, 10 ° or less, or 7 ° or less ( Any of the former example of the lower limit value and the latter example of the upper limit value may be combined.)

In addition, the inner diameter of the first hole 10a at the first end 11 may be smaller than the inner diameter of the second hole 10b, may be the same (provided that there is a difference due to a processing error), or may be larger. Good. For example, the inner diameter of the first end 10 of the first hole 10a is 以上 or more, ／ or ４ or more, and 2 times or less, 1.5 times or less of the inner diameter of the second hole 10b. It is twice or less (any of the former example of the lower limit value and the latter example of the upper limit value may be combined).

Here, assuming that the end face of the first end 11 of the first hole 10a is the first end face 11a, the first end face 11a may be an annular shape having a circular opening. The outer diameter D1 of the first end face 11a in this case may be 0.4 mm or less. The inventor has found out that the liquid attached to the first end face 11a is taken into the capillary 10 when the capillary 10 is pulled out of the liquid. As a result, the amount of liquid taken into the capillary 10 slightly increases with respect to the amount intentionally sucked. When the outer diameter of the first end face 11a is large, the amount of the liquid to be increased also increases, which causes a problem when a small amount of liquid is sucked. By setting the outer diameter of the first end face 11a to 0.4 mm or less, it is possible to prevent many droplets from adhering to the first end face 11a, and a small amount of liquid can be sucked with high accuracy.

FIG. 7 shows the result of measuring the amount of liquid (water) attached to the first end face 11a under various conditions in the capillary shown in FIG. FIG. 8 shows various conditions at that time. In FIG. 7, the horizontal axis indicates the outer diameter D1. The vertical axis indicates the amount of liquid adhering to the first end face 11a. The plot shows the relationship between the outer diameter D1 and the measured amount of adhesion.

よう As shown in FIG. No. 1 to No. The liquid adhesion amount was measured for six types of capillaries up to six. The six types of capillaries differ from each other in the shape and material of the first member 15, the outer diameter D1, and the inner diameter D2. In the column of the shape of the first member 15, “taper” indicates that the inner diameter D <b> 2 and the outer diameter D <b> 1 of the first member 15 become smaller toward the first end 11 as in the example shown in FIG. 2. ing. Also, “straight” indicates that the inner diameter D2 and the outer diameter D1 of the first member 15 are constant from the second end 12 to the first end 11 unlike the example of FIG. The meanings of the abbreviations in the column of the material of the first member 15 are as follows. PP: polypropylene, FEP: flexible electric pipe, ETFE: ethylene tetrafluoro ethylene, PA12: polyamide12. In addition, No. The material No. 5 has a water-repellent film formed on a portion of the glass capillary which comes into contact with the liquid.

According to FIG. 7, it can be seen that by setting the outer diameter D1 of the first surface 11a to 0.4 mm or less, the amount of liquid adhering to the first end surface 11a can be reduced regardless of other conditions. Specifically, in the example of FIG. 7, by setting the outer diameter D1 to 0.4 mm or less, the amount of adhesion can be reduced to 5.0 nl or less. In addition, in the example of FIG. 7, when the outer diameter D1 exceeds 0.4 mm, the rate of change of the increase in the amount of adhesion with respect to the increase in the outer diameter D1 increases. Significance can be found about

At this time, the inner diameter D2 of the first end face 11a may be 0.06 mm or more. If the inner diameter D2 of the first end face 11a is too small, the flow path resistance increases, and the amount of liquid that can be sucked by a predetermined pressure change decreases. FIG. 9 shows a change in the amount of the sucked liquid when the inner diameter D2 of the first end face 11a is changed. In this figure, the horizontal axis indicates the inner diameter D2. The vertical axis indicates the liquid suction amount due to a predetermined pressure change. The plot shows the relationship between the inner diameter D2 and the suction amount, and includes some approximate values.

According to FIG. 9, it can be seen that by setting the inner diameter D2 of the first end face 11a to 0.06 mm or more, it is possible to prevent the amount of the sucked liquid from becoming too small. Further, in the example of FIG. 9, the aspect of the change in the suction amount with respect to the change in the inner diameter D2 is exponential, and by increasing the inner diameter D2 to 0.06 mm or more, the suction amount can be increased by increasing the inner diameter D2. It has been made easier. Contrary to the above description, an extremely small amount of suction may be realized by setting the inner diameter D2 to less than 0.06 mm.

(First member and second member)
The capillary 10 has a first member 15 that forms the first hole 10a, and a second member 16 that forms the second hole 10b. As described above, by forming the capillary 10 from a plurality of members, for example, it is easy to make the water repellency of the first hole 10a different from the water repellency of the second hole 10b.

１The first member 15 and the second member 16 may be made of various materials already mentioned as the material of the capillary 10. For example, the first member 15 is integrally formed of resin as a whole. In addition, for example, the entire second member 16 is integrally formed of glass. The water repellency of the resin forming the first member 15 is higher than the water repellency of the glass forming the second member 16.

The material of the second member 16 may be a light-transmitting material, and the material of the first member 15 may or may not be a light-transmitting material. In other words, the light transmission of the second member 16 may be higher than the light transmission of the first member 15. In this case, for example, a material having high water repellency can be selected as the material of the first member 15. On the other hand, as the material of the second member 16, a material suitable for irradiating the liquid with light for analyzing the liquid can be selected.

固定 The first member 15 and the second member 16 may be fixed by an appropriate method. Examples of the fixing method include fitting (press-fitting) of one member to the other member, locking with a claw, bonding with an adhesive, and welding by melting and solidifying at least one member. it can. Two or more of these methods may be combined. Alternatively, both members may be formed by forming one member first and filling a material for the other member into a mold in which the one member is arranged. Further, between the first member 15 and the second member 16, a packing made of a material having lower rigidity may be disposed.

In the illustrated example, the second member 16 is press-fitted into the first member 15 and both are fixed. Specifically, the first member 15 has a third hole 15a extending from the first hole 10a to a side opposite to the first end 11. The third hole 15a has a larger inner diameter than the first hole 10a. As a result, a step 15b is formed at the boundary between the first hole 10a and the third hole 15a. On the other hand, the second member 16 has an outer diameter equal to or slightly larger than the inner diameter of the third hole 15a. Then, the second member 16 is inserted into the third hole 15a from the side opposite to the first hole 10a, and the tip is locked to the step 15b. The detachment of the second member 16 from the first member 15 is prevented by the frictional force generated by the direct contact between the two members.

Also, even when the second member 16 is inserted into the first member 15 as described above, both may be joined. For example, an adhesive may be arranged between the inner surface of the third hole 15a and the outer surface of the second member 16. In this case, the outer diameter of the second member 16 may be slightly smaller, equal, or slightly larger than the inner diameter of the third hole 15a.

In the illustrated example, each of the third hole 15a and the second member 16 has a constant cross section and extends over its entire length. However, one or both of them may extend in a fixed cross section only in a part of the length direction, and may be fitted only in a portion extending in the fixed cross section. Further, the portions of the third hole 15a and the second member 16 that are fitted to each other do not have to extend in a fixed cross section. For example, both may be tapered so that the diameter increases toward the second end 12. Further, for example, a protrusion may be provided on at least one of the inner surface of the third hole 15a and the outer surface of the second member 16, so that the contact pressure may be increased.

段 The step surface 15ba of the step portion 15b on the side of the second member 16 is inclined, for example, so that the inner side in the radial direction of the capillary 10 is located closer to the second member 16 side. On the other hand, the distal end face 16a of the second member 16 on the side of the step portion 15b is, for example, a planar shape orthogonal to the length direction of the capillary 10. A radially inner corner 15bb (an inner edge of the step surface 15ba) of the step 15b is in contact with the distal end surface 16a of the second member 16. Therefore, the contact between the step portion 15b and the second member 16 is a line contact. Note that the contact between the step portion 15b and the second member 16 may be different from the illustrated example. For example, the step surface 15ba may be a surface orthogonal to the length direction of the capillary 10, and the step surface 15ba and the tip end surface 16a may be in surface contact.

外形 The outer shape (the shape of the outer surface) of the first member 15 and the second member 16 may be appropriate. In the illustrated example, the first member 15 has a first portion 15e having a first end 11 and a second portion located on the second end 12 side with respect to the first portion 15e. 15f.

The first portion 15e has, for example, a part (most of the illustrated example) on the first end 11 side of the first hole 10a. The first portion 15e has, for example, a substantially constant thickness (length from the inner surface to the outer surface) over the entire length of the capillary 10 in the length direction. The outer shape of the first portion 15e is also tapered, corresponding to the tapered first hole 10a. The thickness of the first portion 15 e is relatively thin, for example, smaller than the thickness of the second member 16.

The second portion 15f has, for example, a part of the first hole 10a opposite to the first end 11 and a third hole 15a. The outer diameter of the second portion 15f is larger than that of the first portion 15e, for example. Further, the thickness of the second portion 15f is relatively thick, for example, larger than the thickness of the first portion 15e and the thickness of the second member 16. The shape of the outer surface of the second portion 15f is, for example, constant in the length direction of the capillary 10.

[A series of pipette operations]
An example of the operation of the pipette 1 will be described. FIG. 4 is a graph schematically illustrating an example of a temporal change of a voltage (signal level) in the drive signal SgA (Sg0 to Sg52) output from the first control unit 24. In FIG. 4, the horizontal axis t indicates time, and the vertical axis V indicates voltage. FIGS. 5A to 5F are schematic diagrams showing the state of the capillary 10 at any time shown on the horizontal axis of FIG.

(4) As shown in FIG. 4, the drive signal SgA output from the first control unit 24 to the actuator 40 has a waveform in which the voltage changes over time. On the other hand, the actuator 40 bends by a deformation amount corresponding to the applied voltage. The correspondence here is, for example, a one-to-one correspondence, in other words, a relation in which the amount of deformation is uniquely defined with respect to the voltage (excluding the state where the deformation is saturated). Therefore, the actuator 40 to which the drive signal SgA has been input follows the pressure of the drive signal SgA (change in voltage over time) so that the volume of the pressure chamber 21 becomes a volume corresponding to the voltage of the drive signal SgA. The volume of the chamber 21 is changed.

The relationship between the amount of change in the voltage of the drive signal SgA and the amount of change in the volume of the pressure chamber 21 is not necessarily a proportional relationship. However, for the sake of convenience, the description will be made assuming a proportional or nearly proportional relationship. Therefore, FIG. 4 may be regarded as showing not only the temporal change of the voltage of the drive signal SgA but also the temporal change of the volume of the pressure chamber 21.

基準 One of the internal electrode 42 and the surface electrode 44 is provided with a reference potential, and the other is supplied with the drive signal SgA. The voltage in FIG. 4 indicates a potential difference between the reference potential and the drive signal SgA. In other words, the drive signal SgA is an unbalanced signal. However, the drive signal SgA may be a balanced signal in which the potential is changed in both the internal electrode 42 and the surface electrode 44 and the potential difference is the voltage shown in FIG. Note that, in the present embodiment, a case where the drive signal SgA is an unbalanced signal is taken as an example, and therefore, the voltage in FIG. 4 may be described below as the potential of the drive signal SgA.

(4) The increase in the voltage of the drive signal SgA (change of the potential to the positive side) may correspond to an increase in the volume of the pressure chamber 21 or may correspond to a decrease in the volume of the pressure chamber 21. In other words, the direction of the internal electrode 42 and the surface electrode 44 from the electrode to which the drive signal SgA is applied to the electrode to which the reference potential is applied is opposite to the polarization direction of the piezoelectric ceramic layer 40a. Or the same orientation. Hereinafter, for convenience, it is assumed that an increase in the voltage of the drive signal SgA corresponds to an increase in the volume of the pressure chamber 21 (that is, suction of the liquid).

In the following, not only the operation of the pipette 1 itself, but also the operation performed by a user of the pipette 1 or an apparatus using (or including) the pipette 1 will be described. Here, a mode in which the user operates the pipette 1 will be described as an example. The operation on the pipette 1 by the user may be appropriately read as the operation on the pipette 1 of the device. For example, the movement of the pipette 1 by the user may be the movement of the pipette 1 by the device, and the operation of the user on the switch (not shown) of the pipette 1 may be the output of a command signal to the pipette 1 by the device. The apparatus may perform the same operation as the user on the pipette by, for example, sequence control.

(Time t0 to t1: liquid contact etc.)
Before time t1, the first control unit 24 outputs an initial signal Sg0 to the actuator 40 in response to a user operation on a switch (not shown). The initial signal Sg0 is a signal having a constant potential. Thereby, the volume of the pressure chamber 21 is maintained at a predetermined initial volume. The potential of the initial signal Sg0 may be a reference potential or may be different from the reference potential. Note that the drive signal SgA does not need to include the initial signal Sg0. That is, before time t1, the driving signal SgA may not be output, instead of the state where the initial signal Sg0 is output. The valve 23 is closed after time t0 unless otherwise specified.

The user brings the first end 11 of the capillary 10 into contact with the first liquid L1 before the time t1 (performs a liquid contacting step). Then, the user instructs the pipette 1 to suction the first liquid L1 by operating a switch (not shown) of the pipette 1. The time of this instruction corresponds to time t1 in FIG.

(Time t1 to t2: suction of the first liquid, etc.)
When the suction of the first liquid L1 is instructed, the first control unit 24 outputs a first suction signal Sg1 for driving the driving unit 50 so that the volume of the pressure chamber 21 increases. The first suction signal Sg1 is, for example, a signal that rises from the potential V0 of the initial signal Sg0 to a predetermined potential V1 and maintains the potential V1. Thereby, the first liquid L1 is sucked into the capillary 10 and held near the first end 11 of the capillary 10. The suction amount roughly corresponds to a potential difference from the potential V0 to the potential V1. In other words, the potential difference is set according to the target value of the suction amount.

(4) When a part of the first liquid L1 is sucked into the capillary 10, the user pulls up the capillary 10 from the rest of the first liquid L1 (performs a liquid separation step). Next, the user brings the first end 11 of the capillary 10 into contact with the second liquid L2 (performs a liquid contact step). Then, the user instructs the pipette 1 to suck the second liquid L2 by operating a switch (not shown) of the pipette 1. The time of this instruction corresponds to time t2 in FIG.

(Time t2 to t3: suction of the second liquid, etc.)
When the suction of the second liquid L2 is instructed, the first control unit 24 outputs a second suction signal Sg2 for driving the driving unit 50 so that the volume of the pressure chamber 21 increases. The second suction signal Sg2 is, for example, a signal that rises from the potential V1 of the first suction signal Sg1 to a predetermined potential V2 and maintains the potential V2. As a result, the second liquid L2 is sucked into the capillary 10 and held near the first end 11 of the capillary 10. FIG. 5A shows the state at this time. The suction amount of the second liquid L2 roughly corresponds to the potential difference from the potential V1 to the potential V2. In other words, the potential difference is set according to the target value of the suction amount.

(4) When a part of the second liquid L2 is sucked into the capillary 10, the user pulls up the capillary 10 from the rest of the second liquid L2 (performs a liquid separation step). Then, the user instructs the pipette 1 to mix the first liquid L1 and the second liquid L2 by operating a switch (not shown) of the pipette 1. The time of this instruction corresponds to time t3 in FIG.

(Time t3 to t4: air suction etc.)
When the mixing of the first liquid L1 and the second liquid L2 is instructed, the first control unit 24 outputs an air suction signal Sg3 for driving the driving unit 50 so that the volume of the pressure chamber 21 increases. The air suction signal Sg3 is, for example, a signal that rises to approximately a predetermined potential V3 and maintains the potential V3. Thus, the first liquid L1 and the second liquid L2 move toward the second end 12 and stop at a predetermined position in the capillary 10. FIG. 5B shows the state at this time. The movement amount of the first liquid L1 and the second liquid L2 roughly corresponds to the potential difference from the potential V2 to the potential V3. In other words, the potential difference is set according to the target value of the movement amount.

The stop position of the first liquid L1 and the second liquid L2 may be a position where both the first liquid L1 and the second liquid L2 are located on the first end 11 side of the boundary 14 or the first liquid L1. Both the first liquid L1 and the second liquid L2 may be located at positions closer to the second end 12 than the boundary 14, or may be located at a position where either the first liquid L1 or the second liquid L2 straddles the boundary 14. Good. In the description of the present embodiment, the subsequent operation will be described by taking as an example a case where both the first liquid L1 and the second liquid L2 are located on the first end 11 side of the boundary 14.

When both the first liquid L1 and the second liquid L2 are located on the first end 11 side or the second end 12 side of the boundary 14, the liquid and the boundary 14 may be separated from each other or may be adjacent to each other. Is also good. The term “adjacent” refers to, for example, a distance at which the boundary 14 is separated from the liquid or a distance at which the liquid is overlapped (any distance may be based on the center of the liquid surface) in the length direction of the capillary 10. , 1/10 or less of the length obtained by dividing the volumes of the first liquid L1 and the second liquid L2 by the area of the cross section at the boundary 14 of the first hole 10a.

When the second control unit 25 determines that a predetermined time has elapsed after the start of the output of the air suction signal Sg3, the second control unit 25 controls the valve 23 to open the open flow path 28. Note that, as described above, this control may be performed by either outputting the signal or stopping the output of the signal. The predetermined time is a time sufficient for the first liquid L1 and the second liquid L2 to move to the target position by the air suction signal Sg3.

(Time t4 to t5: restoration of pressure chamber, etc.)
When the first control unit 24 determines that a predetermined time has elapsed after starting the control for opening the valve 23 (time t4), the first control unit 24 outputs a restoration signal Sg4 for driving the driving unit 50 so that the volume of the pressure chamber 21 decreases. I do. The restoration signal Sg4 is, for example, a signal that generally drops to a predetermined potential V4 and maintains the potential V4. Although the volume of the pressure chamber 21 is reduced by the restoration signal Sg4, since the valve 23 is opened, the portion of the capillary 10 closer to the second end 12 than the first liquid L1 and the second liquid L2 is. No pressure boost is performed. As a result, the positions of the first liquid L1 and the second liquid L2 do not change.

The predetermined time from the opening of the valve 23 to the time t4 is a time sufficient to open the valve 23. The potential V4 may be the same, higher, or lower than the initial potential V0 and / or the reference potential. In the illustrated example, the potential V4 is the same as the initial potential V0. When the potential V4 is the reference potential, the restoration signal Sg4 has a falling portion (intentionally used as a signal) generated in a process of transition from the state in which the air suction signal Sg3 is being output to the state in which the output is stopped. That is not the one output to

After that, if the second control unit 25 determines that the predetermined time has elapsed from the time t4, the second control unit 25 controls the valve 23 to close the open flow passage 28. Note that, as described above, this control may be performed by either outputting the signal or stopping the output of the signal. The predetermined time from time t4 is a time sufficient for the actuator 40 to be displaced by the restoration signal Sg4 corresponding to the potential V4.

(Time t5 to t8: mixing, etc.)
When the first control unit 24 determines that a predetermined time has elapsed after starting the control to close the valve 23 (time t5), the mixing signal Sg5 for driving the driving unit 50 so that the volume of the pressure chamber 21 repeatedly increases and decreases (time t5). Sg51 and Sg52). Thereby, the movement of the liquid toward the second end 12 shown in FIG. 5B (FIG. 5F), FIG. 5C and FIG. 5D, and FIG. 5D and FIG. (E) and the movement of the liquid to the first end 11 shown in FIG. 5 (f) are alternately repeated. Eventually, the first liquid L1 and the second liquid L2 are stirred, and both are mixed. The number of repetitions may be set as appropriate.

Thereafter, for example, the mixed liquid is irradiated with light while being held in the capillary 10 (for example, in the second member 16), and its properties are examined. For example, a fluorescence measurement, a scattering measurement, an absorption measurement, and / or a spectroscopic measurement are performed. Although not particularly shown, prior to the measurement, the liquid may be moved to a position suitable for measurement by the same operation as the operation of moving the liquid to an arbitrary position between times t3 and t4. The mixed liquid may be discharged from the capillary 10 and used for various purposes instead of being used for measurement while being held in the capillary 10.

In FIG. 4, the waveform of the drive signal SgA is a waveform composed of a plurality of straight lines such as a rectangular wave. However, part or all of the waveform of the drive signal SgA may be a waveform including a curve such as a sine wave.

[Mixing operation of pipette]
The mixed signal Sg5 alternates between a first signal Sg51 that drives the drive unit 50 so that the volume of the pressure chamber 21 increases and a second signal Sg52 that drives the drive unit 50 so that the volume of the pressure chamber 21 decreases. Contains repeatedly. As shown in FIG. 5B (FIG. 5F), FIG. 5C and FIG. 5D, the liquid (first liquid L1 and second liquid L1 and second liquid L1) At least a part of the liquid L2) flows from the first hole 10a to the second hole 10b. Similarly, as shown in FIGS. 5D, 5E, and 5F, due to the increase in the volume of the pressure chamber 21, at least a part of the liquid is removed from the second hole 10b through the second hole 10b. It flows to one hole 10a. That is, the liquid reciprocates at least partially over the boundary 14 repeatedly.

All of the liquid (L1 + L2) may repeatedly exceed the boundary 14 as shown in the illustrated example, or, unlike the illustrated example, only a part thereof may repeatedly exceed the boundary 14. In the case where all of the liquid repeatedly crosses the boundary 14, the liquid may leave the boundary 14 after crossing the boundary 14 and then return, or may return from a state in which the liquid exceeds the boundary 14 and is adjacent to the boundary 14. Is also good. "Adjacent" is as described in the air suction signal Sg3 and the description of FIG. 5B. Whether all or a part of the liquid exceeds the boundary 14 or separates from the boundary 14 differs depending on whether the liquid flows toward the first hole 10a or the second hole 10b. May be changed, or may be changed in the process of repeating reciprocation.

In the description of the present embodiment, the liquid (L1 + L2) moves from the state in which the liquid (L1 + L2) exceeds the boundary 14 and is adjacent to the boundary 14 both when flowing toward the first hole 10a and when flowing toward the second hole 10b. Take a case where the vehicle is turned back and the state is maintained even if reciprocation is repeated. In such a case, for example, the whole liquid can be made to exceed the boundary 14, and the reciprocating cycle can be shortened.

The first signal Sg51 and the second signal Sg52 may be appropriately set so that the above-described operation is realized.

For example, first, in the present embodiment, immediately before mixing, the liquid (L1 + L2) is adjacent to the boundary 14 on the first end 11 side by the air suction signal Sg3. In this case, the mixed signal Sg5 includes, for example, first (as a signal whose output starts at time t5) the first signal Sg51 for moving the liquid to the second end 12 side, for example. In addition, the amount of change in the potential of the first signal Sg51 (the amount of increase in the volume of the pressure chamber 21) and the amount of change in the potential of the second signal Sg52 (the amount of decrease in the volume of the pressure chamber 21) are each approximately a liquid ( L1 + L2). The last signal included in the mixed signal Sg5 may be either the first signal Sg51 or the second signal Sg52. For example, the signal included in the mixed signal Sg5 second from the start (the second signal Sg52 in the present embodiment).

Note that, unlike the above, the liquid may be made to be adjacent to the second end 12 side of the boundary 14 by the air suction signal Sg3. In this case, the mixed signal Sg5 may include, for example, the second signal Sg52 for first moving the liquid to the first end 11 side. Further, the liquid may be spread over the boundary 14 by the air suction signal Sg3. In this case, the mixed signal Sg5 may include, for example, a signal in which the amount of change in the potential of the first signal Sg51 or the second signal Sg52 is first reduced. Conversely, the liquid may be separated from the boundary 14 by the air suction signal Sg3. In this case, the mixed signal Sg5 may include, for example, a signal in which the amount of change in the potential of the first signal Sg51 or the second signal Sg52 is first increased.

When the first signal Sg51 and the second signal Sg52 are inverted with respect to the passage of time, the first signal Sg51 and the second signal Sg52 may have the same waveform or different waveforms. In other words, the waveforms of both signals may be line-symmetric or asymmetric with respect to an axis of symmetry (not shown) parallel to the vertical axis of the graph shown in FIG. In the example shown in FIG. 4, the waveforms of both signals are asymmetric.

Specifically, for example, the rate of change of the potential of the first signal Sg51 over time is greater than the rate of change of the potential of the second signal Sg52 over time. In the illustrated example, the first signal Sg51 is a signal whose potential rises rapidly (with a rise time of about 0), and the second signal Sg52 is a signal whose potential gradually decreases in proportion to time. Have been. That is, the combination of the first signal Sg51 and the subsequent second signal Sg52 is a so-called reverse sawtooth signal. Specific values of these rates of change may be set as appropriate.

{Also, for example, the change amount dV52 of the potential of the second signal Sg52 (the decrease amount of the volume of the pressure chamber 21) is larger than the change amount dV51 of the potential of the first signal Sg51 (the increase amount of the volume of the pressure chamber 21). The difference may be set as appropriate, and may be set, for example, such that the operation described below is performed. Since the change dV52 is larger than the change dV51, the potential of the mixed signal Sg5 gradually decreases. When the mixing is completed (when the output of the mixed signal Sg5 is completed), the potential of the mixed signal Sg5 may be smaller, equal to, or larger than the potential V0 of the initial signal Sg0 and / or the reference potential. Is also good.

As described above, in the present embodiment, the pipette 1 has the capillary 10 open at both ends (the first end 11 and the second end 12) in the length direction and the inside of the capillary 10 via the second end 12. It has a communicating pressure chamber 21, a drive unit 50 that changes the volume of the pressure chamber 21, and a control unit (first control unit 24) that controls the drive unit 50. The capillary 10 has a first pipe part 17 located on the first end 11 side and a second pipe part 18 located on the second end 12 side. The first pipe part 17 has a first hole 10a penetrating in the length direction, and the second pipe part 18 has a second hole 10b penetrating in the length direction. The second hole 10b is connected to the second end 12 of the first hole 10a. The water repellency of the inner surface of the first hole 10a is different from the water repellency of the inner surface of the second hole 10b. Then, the first control unit 24 repeatedly increases and decreases the volume of the pressure chamber 21 so that at least a part of the liquid in the capillary 10 reciprocates over the boundary between the first hole 10a and the second hole 10b. To control the driving unit 50.

Therefore, for example, when the liquid exceeds the boundary 14, the flow of the liquid is disturbed due to the difference in water repellency, and thus the liquid is easily stirred. Specifically, for example, when the liquid crosses the boundary 14 from the lower side of the water repellency to the higher side, the liquid near the inner surface of the capillary 10 is less likely to flow along the inner surface of the capillary 10. As a result, for example, the flow of the liquid is likely to be separated from the inner surface of the capillary 10, and the vortex is likely to be generated. The vortex promotes agitation of the liquid. Thus, for example, mixing of the two liquids is promoted.

In the present embodiment, the water repellency of the inner surface of the first hole 10a is higher than the water repellency of the inner surface of the second hole 10b.

場合 In this case, for example, the flow from the second hole 10b to the first hole 10a has a higher resistance than the flow in the opposite direction. As a result, for example, the possibility that the liquid is ejected from the first end 11 during mixing is reduced. Further, when the first hole 10a extends from the boundary 14 to the first end 11, when the liquid is sucked from the first end 11, the possibility that the liquid adheres to the first end 11 is reduced. You. As a result, for example, the correspondence between the increase in the volume of the pressure chamber 21 and the suction amount of the liquid is stabilized, and the accuracy of liquid measurement is improved.

In the present embodiment, the inner diameter of the first hole 10a is larger than the inner diameter of the second hole 10b at the boundary 14 between the first hole 10a and the second hole 10b.

In this case, for example, when the liquid exceeds the boundary 14, the flow of the liquid is disturbed due to the difference in the inner diameter, and the two liquids are more likely to be mixed. Specifically, for example, when the liquid crosses the boundary 14 from the side having the smaller inner diameter to the side having the larger inner diameter, the flow is likely to be separated from the inner surface of the capillary 10 and a vortex is likely to be generated. The vortex promotes agitation of the liquid. Further, when the water repellency of the first hole 10a is higher than the water repellency of the second hole 10b, the direction in which the water repellency increases and the direction in which the inner diameter increases are the same. As a result, for example, the effect that peeling is likely to occur due to an increase in water repellency and the effect that peeling is likely to occur due to an increase in the inner diameter are superimposed. As a result, the effect of promoting the stirring is improved.

In the present embodiment, the inner diameter of the first hole 10a is larger toward the second hole 10b.

In this case, for example, the liquid is more likely to be disturbed than when the inner diameter of the first hole 10a is constant. As a result, for example, stirring of the liquid is promoted. Further, for example, when the first hole 10a extends to the first end 11, the inner diameter of the first end 11 can be reduced to improve the accuracy of liquid measurement. On the other hand, at the boundary 14, the inner diameter of the first hole 10a is made larger than the inner diameter of the second hole 10b, and the above-described effect of promoting mixing due to the difference in the inner diameter can be obtained.

In addition, in the present embodiment, the capillary 10 has a first member 15 and a second member 16. The first member 15 is hollow having a first hole 10a. The second member 16 has a hollow shape having the second hole 10 b and is fixed to the first member 15.

In this case, for example, it is easy to make the material forming the first hole 10a and the material forming the second hole 10b different from each other. As a result, for example, it is easy to make the water repellency of the first hole 10a and the water repellency of the second hole 10b different from each other.

In the present embodiment, the first member 15 extends from the first hole 10a to the side opposite to the first end 11 from the first hole 10a, and has a larger inner diameter than the first hole 10a. And a stepped portion 15b due to the inner diameter of the first hole 10a being smaller than the inner diameter of the third hole 15a. The second member 16 is inserted into the third hole 15a and locked on the step 15b, and has a tip surface 16a on the step 15b side. The step surface 15ba on the tip surface 16a side of the step portion 15b is inclined so that the inner side in the radial direction of the capillary 10 is located closer to the tip surface 16a. A radially inner corner portion 15bb of the step portion 15b is in contact with the distal end surface 16a.

In this case, for example, the second member 16 can be connected to the first member 15 with a simple configuration in which the two members are inserted. Further, for example, the contact between the second member 16 and the step portion 15b is a line contact, so that it is easier to secure a contact pressure than in the case of a surface contact. As a result, for example, the sealing performance at the boundary 14 can be improved. In addition, for example, a space is formed outside the corner 15bb between the distal end surface 16a of the second member 16 and the step 15b. This space can be used, for example, to release excess adhesive when an adhesive is interposed between the inner surface of the first member 15 and the outer surface of the second member 16.

Also, in the present embodiment, the first member 15 is made of resin, and the second member 16 is made of glass.

In this case, for example, it is easy to increase the water repellency of the first member 15 and lower the water repellency of the second member 16. For example, it is easy to set the contact angle of the first member 15 to 95 ° or more and the water repellency of the second member 16 to 60 ° or less. That is, it is easy to increase the difference in water repellency between the first hole 10a and the second hole 10b. As a result, for example, it is easy to improve the effect of promoting mixing due to the difference in water repellency. Further, since a resin that can be easily molded is used as the material of the first member 15, the dimensional accuracy near the first end 11 can be improved, and the accuracy of liquid measurement can be improved. On the other hand, since glass that can easily ensure translucency is used as the material of the second member 16, the accuracy of analyzing a liquid using light can be improved.

In addition, in the present embodiment, the first control unit 24 outputs the drive signal SgA whose signal level (voltage) changes with time and forms a waveform to the drive unit 50. The drive unit 50 changes the volume of the pressure chamber 21 according to a change with time of the voltage of the drive signal SgA so that the volume of the pressure chamber 21 becomes a volume corresponding to the voltage of the drive signal SgA. The drive signal SgA includes the first signal Sg51 and the second signal Sg52 alternately and repeatedly. The first signal Sg51 is a signal for driving the driving unit 50 such that at least a part of the liquid flows from the first hole 10a to the second hole 10b due to an increase in the volume of the pressure chamber 21. The second signal Sg52 is a signal for driving the driving unit 50 so that at least a part of the liquid flows from the second hole 10b to the first hole 10a due to the decrease in the volume of the pressure chamber 21. The waveform of the first signal Sg51 and the waveform obtained by inverting the waveform of the second signal Sg52 so that the elapsed time is reversed are different from each other.

In this case, for example, when the liquid flows from the first hole 10a to the second hole 10b and when the liquid flows in the opposite direction, a flow suitable for each can be formed. For example, the first hole 10a and the second hole 10b are different in water repellency, inner diameter, and / or position with respect to the first end 11, and the flow can be formed in consideration of the difference. For example, it is as follows.

In the present embodiment, the absolute value of the rate of change of the signal level (voltage) of the second signal Sg52 over time is smaller than the absolute value of the rate of change of the voltage of the first signal Sg51 over time.

In this case, the flow from the second hole 10b to the first hole 10a becomes gentler than when the absolute values of the two change rates are the same. As a result, when the liquid flows out from the second hole 10b to the first hole 10a, it is possible to reduce the occurrence of a phenomenon in which the liquid is scattered into fine particles. Further, for example, the possibility that the liquid is discharged from the first end 11 is reduced.

In the present embodiment, the water repellency of the inner surface of the first hole 10a is higher than the water repellency of the inner surface of the second hole 10b. The absolute value of the change amount dV52 of the signal level (voltage) of the second signal Sg52 is larger than the absolute value of the change amount dV51 of the voltage of the first signal Sg51.

In this case, it is easy to keep the liquid that reciprocates over the boundary 14 within a certain range. Specifically, it is as follows. Note that, for convenience of explanation, the strictness of the principle is ignored. When the liquid is located in the capillary 10, a liquid surface on the first end 11 side and a liquid surface on the second end 12 side are formed. At each liquid level, a surface tension acts to shrink the liquid level. Due to this surface tension, a force acting on each liquid surface in the length direction (x direction) of the capillary 10 is generated with a magnitude corresponding to the magnitude of the surface tension and the magnitude of the contact angle. When the liquid is straddling the boundary 14, since the water repellency of the first hole 10a is higher than the water repellency of the second hole 10b, the contact angle on the liquid surface in the first hole 10a is It is larger than the contact angle on the liquid surface in the two holes 10b. Therefore, the force in the x direction acting on the liquid surface in the first hole 10a does not balance with the force in the x direction acting on the liquid surface in the second hole 10b. As a result, the liquid as a whole receives a force from the side having a large contact angle to the side having a small contact angle. That is, the liquid tends to flow from the first hole 10a to the second hole 10b. Therefore, when the absolute value of the amount of change dV51 of the voltage of the first signal Sg51 and the absolute value of the amount of change dV52 of the voltage of the second signal Sg52 are the same, the position of the liquid gradually increases in the process of repeating the reciprocation of the liquid. May shift to the second hole 10b side. However, by making the absolute value of the change amount dV52 larger than the absolute value of the change amount dV51, the position of the liquid can be maintained within a certain range. As a result, for example, it becomes easy to repeat the reciprocation of the liquid so that all of the liquid crosses the boundary 14 and turns back immediately after the crossing. As a result, the effect of promoting agitation utilizing the difference in water repellency can be improved.

[Modification]
(Modification of the second member)
FIG. 6A is a cross-sectional view illustrating a configuration of a capillary 210 according to a modification. The capillary 210 differs from the capillary 10 of the embodiment only in the material constituting the second member. Specifically, the second member 216 according to the modified example has a main body 216x and a water-repellent film 216y that covers at least a part of the inner surface of the main body 216x. The main body 216x is made of, for example, glass. The material of the water-repellent film 216y is as described above. Even in such a configuration, the same effect as the embodiment can be obtained by making the water repellency of the inner surface of the first hole 210a different from the water repellency of the inner surface of the second hole 210b.

(Modification Example of Drive Signal)
FIG. 6B is a diagram illustrating a drive signal SgB according to a modification. This diagram corresponds to a part of FIG. 4 (approximately at times t6 to t8). In this modification, the first signal Sg51 and the second signal Sg52 included in the drive signal SgB are configured by curves. More specifically, in the illustrated example, each of the first signal Sg51 and the second signal Sg52 is configured by a 周期 cycle of a sine wave. Even in such a drive signal SgB, the absolute value of the change rate of the second signal Sg52 may be smaller than the absolute value of the change rate of the first signal Sg51.

Here, the waveform of each of the first signal Sg51 and the second signal Sg52 is configured by a curve, which means that the rate of change changes from the start to the end of each signal. In such a case, whether or not the absolute value of the rate of change of the second signal Sg52 is greater than the absolute value of the rate of change of the first signal Sg51 may be determined based on the average value of the rates of change of both. . That is, in the illustrated example, since the amount of change dV1 occurs in the first signal Sg51 during the time length T1, the average value of the change rate is dV1 / T1. Similarly, in the second signal Sg52, since the change amount dV2 occurs during the time length T2, the average value of the change rate is dV2 / T2. If | dV2 / T2 |> | dV1 / T1 |, it may be determined that the absolute value of the rate of change of the second signal Sg52 is greater than the absolute value of the rate of change of the first signal Sg51.

Although not particularly shown, the signal for repeatedly increasing and decreasing the volume of the pressure chamber 21 may have a shape similar to a rectangular wave. In this case, for example, the rising portion of the rectangular wave is the first signal, the falling portion of the rectangular wave is the second signal, and the portion having a constant potential therebetween is a signal other than the first signal and the second signal. is there.

技術 The technology according to the present disclosure is not limited to the above embodiments and modified examples, and may be implemented in various modes.

For example, the pipette is not limited to the one that mixes two liquids sucked by the pipette itself. Specifically, for example, a capillary in which a reactant is formed in advance on the inner surface is attached to the pipette body, and then a liquid (one liquid) is sucked by the pipette, and the reactant reacts by a reciprocating flow in the length direction of the capillary. May be dissolved in a liquid. Further, for example, a pipette sucks a liquid (one liquid) in which two liquids are already mixed, a solvent (one liquid) in which a solute is already contained, or a liquid (one liquid) in which fine substances are already dispersed. Thus, it may be used to further mix, dissolve or disperse. Further, the pipette may be one that sucks and mixes three or more liquids.

In addition, for example, in the above-described embodiment, an example in which the valve 23 is opened and closed after the air is sucked is shown. However, in some cases, the valve 23 may not be opened and closed. In this case, the restoration signal Sg4 becomes unnecessary, and the mixing signal Sg5 may be output following the air suction signal Sg3. Further, the valve 23 and the control circuit 25 need not be provided.

DESCRIPTION OF SYMBOLS 1 ... Pipette, 10 ... Capillary, 10a ... 1st hole, 10b ... 2nd hole, 21 ... Pressure chamber, 50 ... Drive part, 24 ... 1st control part (control part), 11 ... 1st end, 12 ... No. Two ends, 17: first pipe section, 18: second pipe section.

Claims

A capillary having a first end and a second end which are both ends in a length direction,
A first hole,
A second hole connected to the second end side of the first hole, the second hole having a water repellency of an inner surface different from that of the inner surface of the first hole;
The capillary according to claim 1, wherein the water repellency of the inner surface of the first hole is higher than the water repellency of the inner surface of the second hole.
The capillary according to claim 1, wherein an inner diameter of the first hole is larger than an inner diameter of the second hole at a boundary between the first hole and the second hole.
The capillary according to any one of claims 1 to 3, wherein the first hole has a larger inner diameter toward the second hole.
A hollow first member having the first hole,
The capillary according to any one of claims 1 to 4, wherein the capillary has a hollow shape having the second hole, and has a second member fixed to the first member.
The first member includes:
Said first hole;
A third hole extending from the first hole to a side opposite to the first end, and having a larger inner diameter than the first hole;
A step formed by the inner diameter of the first hole being smaller than the inner diameter of the third hole;
The second member is inserted into the third hole and locked to the step portion,
The second member has a distal end surface on the side of the step portion,
The surface on the distal end surface side of the step portion is inclined so as to be located closer to the distal end surface side in the radial direction of the capillary, and the radially inner corner portion of the step portion is the distal end. The capillary according to claim 5, which is in contact with a surface.
The first member is made of resin,
The capillary according to claim 5, wherein the second member is made of glass, or made of glass except for at least a part of a surface.
When the end face of the first end is a first end face,
The first end face is annular with a circular opening,
The capillary according to any one of claims 1 to 7, wherein an outer diameter of the first end surface is 0.4 mm or less.
The capillary according to claim 8, wherein an inner diameter of the first end surface is 0.06 mm or more.
A capillary according to any one of claims 1 to 9,
A pressure chamber communicating with the interior of the capillary via the second end;
A drive unit for changing the volume of the pressure chamber,
A control unit for controlling the driving unit;
Has,
The capillary has a first pipe portion located on the first end side, and a second pipe portion located on the second end side.
The first pipe portion has the first hole penetrating in a length direction,
The second pipe portion has the second hole penetrating in a length direction,
The control unit controls the drive unit so that the volume of the pressure chamber repeatedly increases and decreases, whereby at least a part of the liquid in the capillary reciprocates over the boundary between the first hole and the second hole. Control the pipette.
The control unit outputs a drive signal whose signal level changes with time and forms a waveform to the drive unit,
The drive unit changes the volume of the pressure chamber following a change with time of the signal level so that the volume of the pressure chamber becomes a volume corresponding to the signal level,
The drive signal is
A first signal for driving the driving unit such that at least a part of the liquid flows from the first hole to the second hole by increasing a volume of the pressure chamber;
A second signal for driving the driving unit such that at least a portion of the liquid flows from the second hole to the first hole due to a decrease in the volume of the pressure chamber;
Are repeated alternately,
The pipette according to claim 10, wherein a waveform of the first signal and a waveform obtained by inverting the waveform of the second signal so that the elapsed time is reversed are different from each other.
The pipette according to claim 11, wherein the absolute value of the rate of change of the signal level of the second signal over time is smaller than the absolute value of the rate of change of the signal level of the first signal over time.
The water repellency of the inner surface of the first hole is higher than the water repellency of the inner surface of the second hole,
The pipette according to claim 11, wherein an absolute value of a change amount of a signal level of the second signal is larger than an absolute value of a change amount of a signal level of the first signal.