JPH11201976A - Droplet jetting device for pipetting fine amount of liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exchange liquid to be jetted just by exchanging a nozzle and to reduce the using amount of the liquid to be jetted. SOLUTION: This droplet jetting device for jetting the fine amount of droplets from the nozzle by an impact force generation means for making impact force act on the liquid to be jetted is composed of a main body 2 provided with the impact force generation means 5 and the nozzle 1 freely attachable and detachable to/from the main body 2 and capable of holding the liquid 7 to be jetted. The liquid 7 to be jetted is held only by the nozzle 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a droplet ejecting apparatus for dispensing an extremely small amount of droplets used for a chemical reaction or the like.

[0002]

2. Description of the Related Art In the field of biotechnology, PCR
(Polymerase Chain Reaction) and EIA (Enzyme Immu
noAssay). In these reactions, it is important to reduce the amount of the reaction solution from the viewpoint of cost reduction and the like. For this reason, a technique for accurately and quickly dispensing a small amount of liquid is required. In recent years, a liquid dispensing device using an ink jet technology has been developed as a technology that meets this demand. The ink jet technology was originally developed for printing, but has been applied as a technology capable of dispensing a small amount of liquid accurately and at high speed.

[0003] Japanese Patent Publication No. 7-6975 and BioTec
hniques Vol.15, No.2, 324 (1993) describes the use of inkjet technology as a dispensing device.
No. 005668 and US Pat. No. 5,449,754.
The specification describes the use of ink-jet technology as an organic chemical synthesis, and further describes JP-A-4-262256 and Analytical Chemistry Vol. 67, No. 17, 3051.
(1995) describe the use of inkjet technology as an immunological reaction.

[0004]

In any of these ink-jet technologies, a liquid to be ejected from a nozzle is supplied from a reservoir provided outside the ink-jet. Can be produced. Therefore, it is useful as a technique for dispensing a large number of microdroplets. However, in general, hundreds of test reagents may be used in a clinical test or the like, and in order to avoid mixing these test reagents, it is necessary to clean the nozzle with a large amount of cleaning liquid for each ejection of one type of droplet. Had to do. Therefore, a large amount of work time is required for one clinical test or the like. Further, in order to perform the operation without rinsing the nozzle, a dedicated nozzle and a liquid reservoir are required for each test reagent, and there is a problem that the apparatus becomes complicated. The present invention has been made in view of such problems of the related art, and has as its object to accurately and rapidly dispense various kinds of trace liquids.

[0005]

According to the present invention, there is provided a droplet ejecting apparatus for ejecting a small amount of droplets from a nozzle by an impact force generating means for applying an impact force to a liquid to be ejected. A main body having the impact force generating means; and a nozzle detachable from the main body and capable of holding a liquid to be ejected, wherein the liquid to be ejected is held only by the nozzle. It is a liquid drop ejection device.

[0006]

Embodiments of the present invention will be described below. In the following description, in order to understand the contents, numbers corresponding to the drawings are given in the description, but the present invention is not limited to this.

1 and 2 schematically show an ink jet apparatus. FIG. 1 shows a state in which a detachable nozzle 1 is joined to an ink jet main body 2, and FIG. 2 shows a state in which it has been detached. Reference numeral 3 denotes a liquid ejection port, 41 denotes a capillary provided in the nozzle 1, 42 denotes a capillary provided in the ink jet main body 2, 5 denotes an impact force generator provided in the ink jet main body 2, and 61 and 62 denote connectors.

First, the basic operation of the present invention will be described with reference to FIG. In FIG. 1, connectors 61 and 62 provided on the nozzle 1 and the ink jet main body 2 are joined together, and capillaries 41 and 42 are in communication. Also,
The capillary 41 on the liquid ejection port 3 side is filled with the liquid to be ejected 7, and is insoluble and inactive with respect to the liquid to be ejected 7 on the side of the impact force generator 5 (upward in the drawing) from the liquid to be ejected 7. Liquid 8 is filled. That is, the capillary 41 and the capillary 42 are connected as one capillary, and the nozzle 1 is filled with the liquid 7 to be ejected, and the upper part thereof is filled with the liquid 8. Here, the liquid 8 is not particularly limited as long as it has an insoluble and inert property with respect to the liquid 7 to be ejected. For example, when the liquid 7 to be ejected is a water-soluble liquid, As the liquid 8, an oil-based liquid (such as silicone oil) can be used.

As the impact force generating means 5, a device usually used in an ink-jet method can be used. Specifically, quartz, Rochelle salt, barium titanate, adenosine diphosphate, or the like is used. It is possible to use a device that uses an impact force due to the piezoelectric effect of the piezo element, or a device that locally generates gas by heating or the like and uses the impact force generated by the gas generation. However, considering the easiness of controlling the generation of the impact force and the possibility of the liquid to be ejected being denatured due to heat generation, an apparatus utilizing the impact force by the piezoelectric effect of the piezo element is preferable. Here, an impact force is applied to the liquid 8 by activating the impact force generating means 5,
The impact force propagates through the liquid 8 in the capillary, acts on the liquid to be ejected 7 held in the capillary 41 in the nozzle 1, and a small amount of liquid droplets (the liquid to be ejected 7) from the liquid ejection port 3.
Is injected.

Next, the configuration of the detachable nozzle 1 which is a feature of the present invention will be described. The nozzle 1 has a structure that can be separated from the impact force generating means 5 on the liquid ejection port 3 side. As a structure that can be separated, in addition to means using a connector as shown in FIG. 1, the capillaries of the nozzle 1 and the ink jet main body 2 are fitted together, or the terminals of the capillaries are brought into contact with each other, and then the surrounding area is taped. Means may be used. However, from the viewpoint of workability, means using a connector is preferable. As a disconnecting structure by a connector, for example, a structure in which a claw portion provided on one connector is engaged with a concave portion provided on the other connector,
There are a structure in which a connector is provided with a helical structure and screwed together, a structure in which connectors are joined by magnetism, and a structure of a combination thereof, but is not limited thereto.

[0011] The material of the connector may be copper, iron, or the like.
Metal such as stainless steel, resin such as polypropylene, polyethylene, polyacetal, polyamide, polyimide, polyamide imide, aramid resin, epoxy resin, or glass or ceramics can be used. Is preferred,
Further, from the viewpoint of moldability, an extrusion molded product or an injection molded product is more preferable. The connector may be made of the same material or a different material as the capillary. For example, when the capillary is made of glass, the connector is preferably made of metal or resin. When the capillary is made of metal, the connector is preferably made of metal or resin. Further, when the capillary is made of resin, the connector is preferably made of resin, and more preferably an integrally molded product.

The material of the capillary in the nozzle 1 is a metal such as copper, iron, stainless steel or the like, a resin such as polypropylene, polyethylene, polyacetal, polyamide, polyimide, polyamideimide, aramid resin, epoxy resin, or the like, similarly to the connector. Glass, ceramics, or the like can be used. However, in order to efficiently transmit the impact force generated by the impact force applying means to the liquid ejection port, it is more preferable to use a material having high rigidity.

According to the present invention, the nozzle 1
It is important that the liquid to be ejected 7 is held only in the liquid. By operating the ink jet main body 2 to which the nozzle 1 containing the liquid to be ejected 7 is attached, the liquid to be ejected 7 can be dispensed. Further, if only the nozzle 1 is replaced, another liquid to be ejected is dispensed. It becomes possible. In addition, since the liquid 7 to be ejected can be dispensed only by the amount held in the nozzle 1, the usage amount of the liquid to be ejected can be reduced.

The means for holding the liquid 7 to be ejected in the capillary 41 of the nozzle 1 is such that, after the nozzle 1 is joined to the ink jet main body 2, a negative pressure is applied to the capillary 42 of the ink jet main body 2 so that the liquid to be jetted from the liquid jet port 3. A method of sucking the jet liquid 7 and the nozzle 1
Attached to the tip of a liquid injection device or a syringe type injector having the same configuration as that described above, the liquid 7 is sucked from the liquid injection port 3 as described above, or the liquid 7 is injected from the liquid injection device side. After the injection, there is a method of removing the nozzle 1 from the apparatus and attaching the nozzle 1 to the inkjet main body 2.
Since the diameter of the liquid injection port 3 is as very small as 10 to 100 μm, even after the liquid 7 to be injected is introduced into the nozzle 1 and the nozzle 1 is removed, the liquid 7 does not overflow due to the surface tension of the liquid 7 to be injected.

The nozzle 1 preferably has a reservoir capable of holding the liquid 7 to be ejected. Specifically, the nozzle
A part of the capillary in 1 is enlarged to have a bulge portion, and the bulge portion is used as a reservoir to hold the liquid 7 to be ejected. (In other words, the shape of a single-sphere pipette) By this, it is possible to hold a larger amount of the liquid 7 to be ejected than simply holding the liquid 7 in the capillary, and it is possible to produce a large number of droplets. The method of transmitting the impact force to the liquid to be ejected in the nozzle through the liquid filled in the capillary in the main body has been described above, but the method is not limited to this, and the impact force is directly applied to the closed nozzle base except for the liquid ejection port. , And
A method is also possible in which an impact force is transmitted to the liquid to be ejected held in the nozzle through the nozzle base to eject the liquid to be ejected.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. A tubular transparent glass capillary 41 was inserted into a hole provided in a polypropylene connector 61 in advance, and was fixed with an adhesive to produce a nozzle 1 (total length: about 1 cm, liquid jet port diameter: about 50 μm, capillary inner diameter). About 0.
8 mm). Then, the nozzle 1 is connected to the ink jet main body 2
To the connector 62 by screwing. Thereafter, the silicone oil 8 was introduced from the ink jet main body 2 side, and it was confirmed that one or two drops of the silicone oil came out from the liquid injection port 3, and it was confirmed that the capillary 41 and the capillary 42 were filled with the silicone oil 8. Prepare pure water 7 (colorless) produced by ion exchange resin in a beaker,
After the liquid jet port 3 was immersed in a beaker, a negative pressure was applied to the silicon oil by a micro syringe (not shown) connected to the capillary 42 on the ink jet main body side to introduce pure water 7 into the capillary 41. At this time, pure water is located at approximately half the position of the nozzle (at a position approximately 0.5 cm from the liquid injection port).
Introduced.

The above silicone oil 8 is placed on a slide glass.
The same silicone oil as that described above was applied to the front of the liquid injection port 3, and the piezoelectric element 5 was operated to drop liquid droplets on a slide glass. Observation with a microscope confirmed that the colorless droplets were floating in the silicone oil, and that the pure water 7 was normally jetted. The nozzle containing pure water was removed, and a new nozzle was attached in the same manner. After performing pre-preparation as in the pure water experiment, water 7 colored in red was introduced into the capillary 41 in the same manner as in the pure water experiment, and was poured into silicon oil on a slide glass. Observation with a microscope confirmed that the red droplets were floating in the silicone oil, and that the red water 7 was normally jetted.

[0018]

According to the present invention, the liquid to be ejected can be exchanged only by exchanging only the liquid ejection port side. In addition, if the amount of the liquid to be ejected is sufficient to enter the liquid ejection port, the ejection can be performed, so that the amount of the liquid to be ejected can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a state in which an inkjet main body and a nozzle are joined.

FIG. 2 is a schematic diagram illustrating a state in which an inkjet main body and a nozzle are detached.

[Explanation of symbols]

 1: Nozzle 2: Inkjet main body 3: Liquid ejection port 41: Capillary (nozzle 1 side) 42: Capillary (inkjet main body 2 side) 5: Impact force generator (piezoelectric element) 61: Connector (nozzle 1 side) 62: Connector (Inkjet body 2 side) 7: Liquid to be injected (pure water, red water) 8: Liquid (silicone oil)

Claims (1)

[Claims] 1. A droplet ejecting apparatus for ejecting a small amount of droplets from a nozzle by an impact force generating means for applying an impact force to a liquid to be ejected, wherein the droplet ejecting apparatus has a main body having the impact force generating means. And a nozzle detachable from the main body and capable of holding a liquid to be ejected, wherein the liquid to be ejected is held only by the nozzle.