LIQUID DISPENSING DEVICE

A liquid dispensing device includes: a discharge part, discharging liquid toward a well of a well plate; and an opening plate, arranged between the discharge part and the well plate and having an opening formed therein corresponding to the well. The opening is smaller in size than the well when the opening plate is viewed in an XY plane.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of Japan Application No. 2022-204393, filed on Dec. 21, 2022. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

Technical Field

The disclosure relates to a liquid dispensing device that dispenses liquid to a well plate.

Related Art

There is known a liquid dispensing device that dispenses a liquid such as a sample or a specimen to a well plate (see, for example, Japanese Patent No. 6446151). In this liquid dispensing device, a predetermined amount of droplets (liquid) are discharged from an inkjet head toward each of a plurality of wells formed in an upper surface of the well plate.

In the conventional liquid dispensing device described above, when the droplets are discharged toward a well, there is a risk that the droplets may float up from this well and scatter to a well around this well due to an airflow generated within this well. As a result, a problem arises in that different droplets mix in each well, resulting in so-called contamination.

SUMMARY

A liquid dispensing device according to one aspect of the disclosure dispenses a liquid to a well plate having a well formed in an upper surface. The liquid dispensing device includes: a discharge part, discharging the liquid toward the well; and an opening plate, arranged between the discharge part and the well plate and having an opening formed therein corresponding to the well. The opening is smaller in size than the well in a plan view of the opening plate.

DESCRIPTION OF THE EMBODIMENTS

The disclosure provides a liquid dispensing device in which contamination can be reduced.

A liquid dispensing device according to a first aspect of the disclosure dispenses a liquid to a well plate having a well formed in an upper surface. The liquid dispensing device includes: a discharge part, discharging the liquid toward the well; and an opening plate, arranged between the discharge part and the well plate and having an opening formed therein corresponding to the well. The opening is smaller in size than the well in a plan view of the opening plate.

According to the present aspect, the opening plate is arranged between the discharge part and the well plate, and the opening is smaller in size than the well in a plan view of the opening plate. Accordingly, when the liquid is discharged from the discharge part through the opening of the opening plate toward the well directly below the opening, most of an airflow generated inside the well may bounce off an outer periphery of the opening to thereby circulate inside the well. Hence, almost no airflow is generated to flow outside the well through the opening, and a situation in which some of droplets discharged into the well float up from the well and scatter to, for example, wells around the well, can be reduced. As a result, contamination can be reduced.

For example, in the liquid dispensing device according to a second aspect of the disclosure, in the first aspect, in a plan view of the opening plate, the opening may be configured to be smaller in size than the well, and an outline of the opening may be configured to be arranged inside an outline of the well.

According to the present aspect, since the outer periphery of the opening of the opening plate protrudes in an annular and eave-like shape inside the well over the entire circumference of the well, contamination can be relatively effectively reduced.

For example, in the liquid dispensing device according to a third aspect of the disclosure, in the first aspect or the second aspect, a lower surface of the opening plate facing the well plate may be configured to have water repellency.

According to the present aspect, a droplet attached to the lower surface of the opening plate can be caused to drip into the well by its own weight.

For example, in the liquid dispensing device according to a fourth aspect of the disclosure, in the third aspect, the lower surface of the opening plate may be configured to have water repellency with a contact angle of 90° or more.

According to the present aspect, a droplet attached to the lower surface of the opening plate can be caused to easily drip into the well by its own weight.

According to the present aspect, for example, in the liquid dispensing device according to a fifth aspect of the disclosure, in any one of the first to fourth aspects, the opening plate may be configured to be made of a conductive material.

According to the present aspect, even if the opening plate is charged, charges on the opening plate can be discharged into the atmosphere. As a result, in the case where droplets discharged from the discharge part are charged, it can be prevented that the droplets repel against the charges on the opening plate and scatter to the outside of the well.

For example, in the liquid dispensing device according to a sixth aspect of the disclosure, in any one of the first to fifth aspects, on the lower surface of the opening plate facing the well plate, a first electrode may be configured to be arranged on the outer periphery of the opening, and the first electrode may be configured to be grounded.

According to the present aspect, even if the opening plate is charged, the charges on the opening plate can be flowed from the first electrode to the ground. As a result, in the case where droplets discharged from the discharge part are charged, it can be prevented that the droplets repel against the charges on the opening plate and scatter to the outside of the well.

For example, in the liquid dispensing device according to a seventh aspect of the disclosure, in the sixth aspect, on an upper surface of the opening plate opposite to the well plate, a second electrode may be configured to be arranged on the outer periphery of the opening, and the second electrode may be configured to be grounded.

According to the present aspect, even if the opening plate is charged, the charges on the opening plate can be flowed from the second electrode to the ground. As a result, in the case where droplets discharged from the discharge part are charged, it can be prevented that the droplets repel against the charges on the opening plate and scatter to the outside of the well.

For example, in the liquid dispensing device according to an eighth aspect of the disclosure, in any one of the first to seventh aspects, a barb curved toward the well may be configured to be formed on the outer periphery of the opening.

According to the present aspect, when droplets are discharged from the discharge part through the opening toward the well directly below the opening, an airflow generated inside the well is able to effectively bounce off the barb formed on the outer periphery of the opening. As a result, contamination can be relatively effectively reduced.

According to the liquid dispensing device according to one aspect of the disclosure, contamination can be reduced.

Hereinafter, embodiments of the disclosure will be described in detail using the drawings. All of the embodiments described hereinafter show general or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components and so on shown in the following embodiments are examples and do not intend to limit the disclosure. Among the components in the following embodiments, the components not recited in the independent claims are described as arbitrary components.

[1. Overall Configuration of Liquid Dispensing Device]

An overall configuration of a liquid dispensing device2according to Embodiment 1 is described with reference toFIG.1toFIG.3.FIG.1is a perspective view schematically illustrating an internal structure of the liquid dispensing device2according to Embodiment 1.FIG.2is an exploded perspective view illustrating a well plate8and an opening plate10of the liquid dispensing device2according to Embodiment 1.FIG.3is a plan view illustrating the well plate8of the liquid dispensing device2according to Embodiment 1.

InFIG.1, a left-right direction of the liquid dispensing device2is the X axis, a front-back direction of the liquid dispensing device2is the Y axis, and an up-down direction of the liquid dispensing device2is the Z axis. In this specification, a positive side of the Z axis is “up”, and a negative side of the Z axis is “down”.

As illustrated inFIG.1, the liquid dispensing device2includes a housing4, a tray6, the well plate8, the opening plate10, a discharge part12, a drive mechanism14, and a controller16. The liquid dispensing device2is a device for dispensing liquid to the well plate8. The liquid is, for example, a sample, a specimen or a reagent used in a test or the like in the medical field or the physical and chemical fields.

The housing4is formed in a hollow box shape. An opening (not illustrated) for putting in and out the well plate8is formed in a front surface of the housing4.

The tray6is for placing the well plate8, and is movably supported by a guide plate (not illustrated) arranged inside the housing4. Accordingly, the tray6is movable along the guide plate between a storage position (the position of the tray6illustrated inFIG.1) where the tray6is stored inside the housing4and a pull-out position (not illustrated) where the tray6is pulled out to a near side (negative side of the Y axis) through the opening of the housing4.

A pair of guide walls18and20for positioning the well plate8with respect to the tray6are arranged on an upper surface of the tray6. Each of the pair of guide walls18and20is formed in a substantially L-shape as viewed in an XY plane. The pair of guide walls18and20respectively contact a pair of diagonal corners among four corners of the well plate8.

As illustrated inFIG.2andFIG.3, the well plate8is, for example, formed in a substantially rectangular plate shape as viewed in the XY plane and made of resin or the like. The well plate8is removably placed on the upper surface of the tray6. In an upper surface of the well plate8, a plurality of wells22for storing droplets (liquid) discharged from the discharge part12are formed in a matrix (for example, 32 rows×48 columns). Each of the plurality of wells22is, for example, a recess formed in a rectangular shape as viewed in the XY plane. The number of wells22formed in one well plate8is, for example, 1536 (=32×48). In a plan view of the XY plane, a horizontal (X-axis direction) length D1of each well22is, for example, 1.7 mm, and a vertical (Y-axis direction) length D2of each well22is, for example, 1.7 mm.

In the present embodiment, the number of wells22formed in one well plate8is 1536. However, the disclosure is not limited thereto, and the number of wells22may be, for example, 24 (=4×6), 96 (=8×12), or 384 (=16×24). As the number of wells22increases, an arrangement interval between the wells22decreases and the size of the wells22decreases.

The opening plate10is a plate for reducing contamination in the well plate8. As illustrated inFIG.1andFIG.2, the opening plate10is arranged to cover the upper surface of the well plate8. That is, the opening plate10is arranged between the well plate8and the discharge part12. A specific configuration of the opening plate10will be described later.

The discharge part12is a unit for discharging droplets toward one or more of the plurality of wells22of the well plate8, and is arranged inside the housing4. A method of discharging droplets by the discharge part12is an inkjet method in which mist-like droplets are discharged.

As illustrated inFIG.1, the discharge part12includes a carriage24, a cartridge26, and a nozzle28. The cartridge26is removably mounted in the carriage24. The inside of the cartridge26is filled with one or more types of liquid to be dispensed to the well plate8. The nozzle28is arranged at a lower end of the carriage24. A plurality of fine nozzle holes are formed in the nozzle28. In the discharge part12, a liquid supplied from the cartridge26is discharged in the form of mist-like droplets from the nozzle28toward the upper surface of the well plate8placed on the tray6in the storage position.

The drive mechanism14includes an X-axis mechanism30, a Y-axis mechanism32, and a Z-axis mechanism34, and is arranged inside the housing4. The X-axis mechanism30is a mechanism for moving the discharge part12in a scanning direction (X-axis direction). The Y-axis mechanism32is a mechanism for moving the discharge part12in a sub-scanning direction (Y-axis direction). The Z-axis mechanism34is a mechanism for moving the discharge part12in the up-down direction (Z-axis direction).

The controller16is for controlling the discharge part12and the drive mechanism14, and is arranged inside the housing4.

While the discharge part12is moving in the sub-scanning direction and reciprocating in the scanning direction, by discharging droplets from the discharge part12onto the upper surface of the well plate8, a predetermined amount (for example, amount on the order of picoliters) of liquid is stored in each of the plurality of wells22of the well plate8. Accordingly, the liquid is dispensed to the well plate8. In one discharge of droplets from the discharge part12, the droplets may be dispensed into each of several to more than ten wells22at once, or may be dispensed only to a single well22.

After the liquid is dispensed to the well plate8, a user, after moving the tray6from the storage position to the pull-out position, is able to take out the well plate8from the tray6by removing the opening plate10from the well plate8. The liquid stored in each of the plurality of wells22of the well plate8is used, for example, for analysis.

[2. Configuration of Opening Plate]

Next, a configuration of the opening plate10is described with reference toFIG.4toFIG.6.FIG.4is a plan view illustrating the opening plate10of the liquid dispensing device2according to Embodiment 1.FIG.5is a cross-sectional view illustrating an essential part of the liquid dispensing device2according to Embodiment 1, taken along line V-V inFIG.4.FIG.6is a cross-sectional view illustrating an essential part of the liquid dispensing device2according to Embodiment 1, taken along line VI-VI inFIG.4.

As illustrated inFIG.4, the opening plate10is, for example, formed in a substantially rectangular plate shape as viewed in the XY plane and made of resin or the like. In the opening plate10, a plurality of openings36are formed in a matrix (for example, 32 rows×48 columns) corresponding to the plurality of wells22of the well plate8. That is, the plurality of openings36correspond to the plurality of wells22on a one-to-one basis. The number of openings36formed in one opening plate10is the same as the number of wells22, and is, for example, 1536 (=32×48). Each of the plurality of openings36is formed in, for example, a rectangular shape as viewed in the XY plane.

For example, if the number of wells22formed in one well plate8is 24, 96, or 384, the number of openings36formed in one opening plate10is 24, 96, or 384, respectively, which is the same as the number of wells22.

The plurality of openings36are respectively arranged directly above the plurality of wells22. Specifically, when the opening plate10is viewed in the XY plane, the size (area) of each of the plurality of openings36is smaller than the size (area) of each of the plurality of wells22, and an outline of each of the plurality of openings36is arranged inside an outline of each of the plurality of wells22. In a plan view of the XY plane, a horizontal (X-axis direction) length D3of each opening36is, for example, 1.0 mm (<D1), and a vertical (Y-axis direction) length D4of each opening36is, for example, 1.0 mm (<D2). As illustrated inFIG.5, an outer periphery of the opening36protrudes in an annular and eave-like shape inside the well22over the entire circumference of the well22. Accordingly, the droplets from the discharge part12may be discharged through the opening36of the opening plate10toward the well22directly below the opening36.

A lower surface (that is, the surface facing the well plate8) of the opening plate10has water repellency. In this case, a water-repellent coating may be applied to the lower surface of the opening plate10, or the opening plate10itself may be made of a water-repellent material. As the water-repellent coating, a fluorine-based surfactant, for example, can be used. As the water-repellent material, a material obtained by adding fluorine or a silicone polymer to a resin, for example, can be used. The lower surface of the opening plate10preferably has water repellency with a contact angle of 90° or more.

As illustrated inFIG.6, on the lower surface of the opening plate10, a positioning protrusion38protruding toward the well22is formed on the outer periphery of the opening36arranged in a corner among the plurality of openings36. When the opening plate10is placed on the upper surface of the well plate8, the positioning protrusion38is removably inserted into the well22, thereby positioning the opening plate10with respect to the well plate8. Accordingly, the plurality of openings36may each be arranged directly above each of the plurality of wells22.

Here, a configuration of a liquid dispensing device100according to a comparative example is described with reference toFIG.7.FIG.7is a cross-sectional view illustrating an essential part of the liquid dispensing device100according to a comparative example. InFIG.7, the same components as those in Embodiment 1 are assigned the same reference numerals, and the description thereof will be omitted.

As illustrated inFIG.7, since the liquid dispensing device100according to the comparative example does not include the opening plate10described above, the following problems occur. When droplets are discharged from the discharge part12toward a well22(hereinafter referred to as “well22a”) of the well plate8, an airflow arising from the discharge of droplets may be generated inside the well22a.This airflow is generated so as not only to circulate inside the well22abut also to flow outside the well22a.Hence, there is a risk that some of the droplets discharged to the well22amay float up from the well22aand scatter to a well22(hereinafter referred to as “well22b”) around the well22adue to the airflow flowing outside the well22a.As a result, a problem arises in that different droplets mix in the well22b,resulting in so-called contamination.

In contrast, since the liquid dispensing device2according to the present embodiment includes the opening plate10, the following effects are achieved. As described above, the outer periphery of the opening36of the opening plate10protrudes in an annular and eave-like shape inside the well22over the entire circumference of the well22of the well plate8.

Accordingly, as illustrated inFIG.5, when the droplets are discharged from the discharge part12through an opening36(hereinafter referred to as “opening36a”) of the opening plate10toward the well22(hereinafter referred to as “well22a”) directly below the opening36a,most of the airflow generated inside the well22amay bounce off an outer periphery of the opening36ato thereby circulate inside the well22a.Hence, almost no airflow is generated to flow outside the well22athrough the opening36a,and a situation in which some of the droplets discharged into the well22afloat up from the well22aand scatter to the well22(hereinafter referred to as “well22b”) around the well22acan be reduced. As a result, occurrence of contamination in the well plate8can be reduced.

As described above, the lower surface of the opening plate10has water repellency. Accordingly, even if some of the droplets discharged into the well22aare carried by the airflow circulating inside the well22aand thus adhere to the outer periphery of the opening36ain the lower surface of the opening plate10, these droplets can be caused to drip into the well22aby their own weight.

A configuration of a liquid dispensing device2A according to a modification of Embodiment 1 is described with reference toFIG.8.FIG.8is a cross-sectional view illustrating an essential part of the liquid dispensing device2A according to a modification of Embodiment 1.FIG.8is a cross-sectional view illustrating an essential part of the liquid dispensing device2A taken along a cutting line corresponding to line VI-VI inFIG.4. In the present modification, the same components as those in Embodiment 1 are assigned the same reference numerals, and the description thereof will be omitted.

As illustrated inFIG.8, in the liquid dispensing device2A of the present modification, the positioning protrusion38described above is not formed on a lower surface of an opening plate10A. That is, the liquid dispensing device2A includes a positioning pin40instead of the positioning protrusion38described above. Through the opening36arranged in a corner among a plurality of openings36of the opening plate10A, the positioning pin40is removably inserted through the well22directly below the opening36. A lower end of the positioning pin40is in contact with a bottom of the well22.

Accordingly, as in Embodiment 1, the opening plate10A is positioned with respect to the well plate8. If the user experiences a feeling that the lower end of the positioning pin40is in contact with the bottom of the well22when inserting the positioning pin40into the opening36, it can be determined that the opening plate10A is correctly positioned.

It is sufficient if the positioning pin40can be pulled out from the well22after the opening plate10A is positioned with respect to the well plate8. Accordingly, the droplets from the discharge part12can be discharged also into the well22into which the positioning pin40has been inserted. Alternatively, the positioning pin40may be left inserted through the well22after the opening plate10A is positioned with respect to the well plate8.

A configuration of a liquid dispensing device2B according to Embodiment 2 is described with reference toFIG.9.FIG.9is a cross-sectional view illustrating an essential part of the liquid dispensing device2B according to Embodiment 2.FIG.9is a cross-sectional view illustrating an essential part of the liquid dispensing device2B taken along a cutting line corresponding to line V-V inFIG.4. In each embodiment illustrated below, the same components as those in Embodiment 1 are assigned the same reference numerals, and the description thereof will be omitted.

As illustrated inFIG.9, in the liquid dispensing device2B, an opening plate10B is made of, for example, a conductive material such as metal, silicon, or carbon. Accordingly, for example, when the opening plate10B is taken out from a plastic packaging bag or the like, even if the opening plate10B is charged with charges (for example, positive charges), the charges on the opening plate10B can be discharged into the atmosphere. As a result, in the case where the droplets discharged from the discharge part12are charged with charges (for example, positive charges), it can be prevented that these droplets repel against the charges on the opening plate10B and scatter to the outside of the well22.

As illustrated inFIG.9, in the liquid dispensing device2B, a barb42is formed on an outer periphery of each of a plurality of openings36B of the opening plate10B. The barb42is curved toward the well22over the entire circumference of the opening36B. Accordingly, when droplets are discharged from the discharge part12through the opening36B toward the well22directly below the opening36B, an airflow generated inside the well22is able to effectively bounce off the barb42of the opening36B. As a result, contamination can be relatively effectively reduced.

A configuration of a liquid dispensing device2C according to Embodiment 3 is described with reference toFIG.10toFIG.13.FIG.10is a plan view illustrating a lower surface side of an opening plate10C of the liquid dispensing device2C according to Embodiment 3.FIG.11is a plan view illustrating an upper surface side of the opening plate10C of the liquid dispensing device2C according to Embodiment 3.FIG.12is a cross-sectional view illustrating an essential part of the liquid dispensing device2C according to Embodiment 3, taken along line XII-XII inFIG.11.FIG.13is a cross-sectional view illustrating an essential part of the liquid dispensing device2C according to Embodiment 3, taken along line XIII-XIII inFIG.11.

In the liquid dispensing device2C, the opening plate10C is composed of, for example, a printed wiring board. As illustrated inFIG.10, on a lower surface (that is, the surface facing the well plate8) of the opening plate10C, a plurality of first electrodes44are arranged on the outer periphery of each of the plurality of openings36. Each of the plurality of first electrodes44is made of, for example, copper foil, and is formed in, for example, a rectangular ring shape as viewed in the XY plane, so as to surround the entire circumference of the opening36. The plurality of first electrodes44are electrically connected to each other by a conductive pattern46made of copper foil or the like.

As illustrated inFIG.11, on an upper surface (that is, the surface opposite to the well plate8) of the opening plate10C, a plurality of second electrodes48are arranged on the outer periphery of each of the plurality of openings36. Each of the plurality of second electrodes48is made of, for example, copper foil, and is formed in, for example, a rectangular ring shape as viewed in the XY plane, so as to surround the entire circumference of the opening36. The plurality of second electrodes48are electrically connected to each other by a conductive pattern50made of copper foil or the like.

As illustrated inFIG.10toFIG.12, a through hole52is formed in a corner of the opening plate10C. The conductive pattern46formed on the lower surface of the opening plate10C and the conductive pattern50formed on the upper surface of the opening plate10C are electrically connected via the through hole52. As illustrated inFIG.12, a guide wall20C includes a support54and a grounding electrode56. The support54protrudes from a side surface of the guide wall20C and supports the lower surface of the opening plate10C. The grounding electrode56is formed on an upper surface of the support54and is electrically connected to the conductive pattern46of the opening plate10C. The grounding electrode56is grounded via, for example, an earth wire (not illustrated). That is, each of the plurality of first electrodes44and the plurality of second electrodes48is grounded via the grounding electrode56.

For example, when the opening plate10C is taken out from a plastic packaging bag or the like, even if the opening plate10C is charged with charges (for example, positive charges), the charges on the opening plate10C can be caused to flow to the ground via each of the plurality of first electrodes44and the plurality of second electrodes48. As a result, as illustrated inFIG.13, in the case where the droplets discharged from the discharge part12are charged with charges (for example, positive charges), it can be prevented that these droplets repel against the charges on the opening plate10C and scatter to the outside of the well22.

Although not illustrated, various electronic components may be mounted on the opening plate10C. For example, an acceleration sensor and a communication module may be mounted on the opening plate10C. The acceleration sensor detects an inclination of the opening plate10C with respect to a horizontal plane (XY plane). The communication module wirelessly transmits a detection signal from the acceleration sensor to the controller16(FIG.1) by a communication method such as Bluetooth (registered trademark) Low Energy (BLE). If the controller16determines that the opening plate10C is inclined with respect to the horizontal plane based on the detection signal received from the communication module, the controller16stops the discharge of droplets from the discharge part12.

Although the liquid dispensing device according to each embodiment of the disclosure has been described above, the disclosure is not limited to each embodiment described above.

In each embodiment described above, a plurality of wells22are configured to be formed in the well plate8. However, the disclosure is not limited thereto, and a single well22may be configured to be formed in the well plate8. In this case, in the opening plate10(10A,10B,10C), a single opening36(36B) may be configured to be formed corresponding to the single well22.

In each embodiment described above, the well22and the opening36are both of a rectangular shape as viewed in the XY plane. However, the disclosure is not limited thereto, and the well22and the opening36may be of any shape such as a polygonal shape or a circular shape. For example, the well22may be of a polygonal shape as viewed in the XY plane, and the opening36may be of a circular shape as viewed in the XY plane.

If there is a configuration for suppressing charging in the opening plates10B and10C as in Embodiments 2 and 3 described above, the size of the opening36with respect to the size of the well22is preferably 80% or less. In this case, a well plate in which the number of wells22is 384 or 1536 is suitable for the well plate8. On the other hand, if there is no configuration for suppressing charging in the opening plates10B and10C, in order to prevent droplets from scattering to the outside of the well22due to charge repulsion, the size of the opening36with respect to the size of the well22is preferably 60% or less. In this case, a well plate in which the number of wells22is 24 or 96 is suitable for the well plate8.

The disclosure can be applied, for example, as a liquid dispensing device for dispensing a liquid such as a reagent to a well plate.