JP2011027473A - Manufacturing method of weighing apparatus, weighing apparatus, and mixing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a weighing apparatus capable of preparing mixed solutions at low costs or preparing required mixed solutions from a small amount of specimen, to provide a manufacturing method capable of easily manufacturing this weighing apparatus, and to provide a mixing apparatus using the weighing apparatus. <P>SOLUTION: In the manufacturing method of the weighing apparatus for liquids, the weighing apparatus comprises both of a first recess and a second recess shallower than the first recess in a substrate 2. The first recess and the second recess communicate with each other on the opening side of their upper parts and have independent recesses independent of each other on the side of their bottoms. The independent recess of the second recess is formed in such a way as to have a prescribed capacity. A plurality of types of masks 10 (10a, 10b, 10c) having different opening diameters are used to collectively dry-etch the substrate 2 and to form at least the first recess and the second recess in the substrate 2 through the use of micro-loading effects. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a weighing device, a weighing device obtained thereby, and a mixing device.

  In recent years, μm-TAS (Micro Total Analysis System), which applies micromachine technology and refines equipment and methods for chemical analysis and chemical synthesis, has attracted attention. The micronized TAS has advantages such as a smaller amount of sample, a shorter reaction time, and less waste compared to a conventional apparatus. Further, when used in the medical field, the burden on the patient can be reduced by reducing the amount of specimen such as blood, and the cost of the test can be reduced by reducing the amount of reagent. In addition, since the amount of specimen and reagent is small, the reaction time is greatly shortened and the efficiency of the test can be improved. And since it is excellent in portability, its application is expected in a wide range such as medical field and environmental analysis.

  Against this background, conventionally, the first flow path for feeding one of the two liquids and the other one of the two liquids are fed. A second flow path, and a third flow path extending from an merging portion of the first flow path and the second flow path on an extension line of the first flow path, and the second flow path. The flow path is composed of two flow paths, and the two flow paths are formed so as to be symmetrically merged from both sides with respect to the first flow path at the merge portion. It has been proposed (see, for example, Patent Document 1).

JP 2005-131556 A

  In the above mixing device, two kinds of liquids to be mixed are arranged in the first ports serving as the respective inlets, and these are merged and mixed at the merging portion, but in order to determine the mixing ratio, the first port is used. In order to accurately arrange the liquid, it is necessary to use an injector such as a micropipette (dispensing device).

By the way, when plural kinds of liquids are mixed, the amount of each liquid depends on the amount of the liquid having the lowest mixing ratio. That is, if the amount of the liquid with the lowest mixing ratio is large, the amount of other liquids also increases. Therefore, when an expensive reagent is used as the other liquid, the cost of the obtained mixed solution becomes very high. End up. In addition, when a small amount of specimen is used as the other liquid, it becomes difficult to adjust to a desired mixing ratio.
On the other hand, even when these expensive reagents and a small amount of sample are used as the liquid with the lowest mixing ratio, in order to reduce the amount of the obtained mixture and reduce the cost of the mixture, It is important to reduce the amount sufficiently.

However, the micropipetter for microinjection that has been generally used in the past has a minimum injection amount of about several hundreds of nl, and sufficiently satisfies the demand for reducing the cost or reducing the amount of specimen. There is no current situation.
The present invention has been made in view of the above circumstances, and the object thereof is to enable the preparation of a mixed solution at a lower cost or the preparation of a mixed solution required with a small amount of specimen. An object of the present invention is to provide a weighing device that can be manufactured, a manufacturing method that can easily manufacture the weighing device, and a mixing device that uses the weighing device.

In the method for manufacturing the weighing device according to the present invention, the substrate has at least a first recess and a second recess having a depth smaller than the first recess, and the first recess and the second recess are provided. Manufactures a liquid measuring device that has independent recesses that communicate with each other on the top opening side and that are independent from each other on the bottom side, and that the independent recesses of the second recess have a predetermined volume. When doing
Using a plurality of types of masks having different opening diameters, dry etching is collectively performed on the substrate, and at least the first concave portion and the second concave portion are formed in the substrate using a microloading effect. It is characterized by.

According to this method for manufacturing a weighing device, the weighing device having at least the first concave portion and the second concave portion is manufactured by batch dry etching using the microloading effect. Can be manufactured.
In the manufactured weighing device, the predetermined amount of liquid is formed in a predetermined volume by injecting a predetermined amount of liquid into the independent recess of the second recess by an injector such as a micropipette. Overflow from the independent recess can be arranged in the independent recess of the first recess communicating with the second recess. That is, the amount of the liquid disposed in the independent recess of the first recess is an amount obtained by subtracting the amount corresponding to the volume of the independent recess of the second recess from the amount measured by the injector. Therefore, by appropriately setting the volume of the independent recess of the second recess, the liquid measured by the injector can be re-measured to, for example, a half or a quarter thereof. Become. This makes it possible to measure even smaller amounts than the minimum amount stipulated by a small amount of injector, and the minimum unit amount of the liquid mixture is provided by mixing the liquid thus weighed. Can be significantly reduced as compared with the prior art.

In the manufacturing method of the weighing device, the plurality of second recesses are formed for one of the first recesses by performing dry etching all together using a plurality of types of masks. Is preferred.
Since the plurality of second recesses are formed, in the obtained weighing device, for example, different liquids are simultaneously metered using different second recesses, and these are directly measured in the independent recesses of the first recesses. It becomes possible to mix.

In the manufacturing method of the weighing device, the top opening side communicates with one of the first recesses by performing dry etching all together using a plurality of types of masks, and on the bottom side. It is preferable to form a third recess having independent recesses independent from each other, and to form the independent recess of the third recess in a predetermined volume different from that of the independent recess of the second recess.
Since the third concave portion is formed separately from the second concave portion, the obtained weighing device uses, for example, the second concave portion and the third concave portion so that different amounts of liquids are different from each other. It is possible to weigh them separately and mix them directly in the independent recesses of the first recess.

In the manufacturing method of the weighing device, the top opening side communicates with one of the second recesses by performing dry etching all together using a plurality of types of masks, and on the bottom side. It is preferable to form a fourth recess having independent recesses independent from each other and to form the independent recess of the fourth recess in a predetermined volume.
In this way, by injecting a predetermined amount of liquid into the independent recess of the fourth recess by an injector such as a micropipette, the predetermined amount of liquid is caused to overflow from the independent recess formed in a predetermined volume. , And can be arranged in an independent recess of the second recess communicating with the fourth recess. Therefore, the liquid disposed in the independent recess of the second recess in this way overflows and is disposed in the independent recess of the first recess, so that the liquid is disposed in the independent recess of the first recess. The amount of the liquid thus obtained is obtained by subtracting the amount corresponding to the volume of the independent recess of the fourth recess and the amount corresponding to the volume of the independent recess of the second recess from the amount measured by the injector. It becomes. Therefore, by appropriately setting the volume of the independent recess of the fourth recess and the volume of the independent recess of the second recess, respectively, the liquid measured by the injector is re-measured to a smaller amount. It becomes possible.

In the method for manufacturing the weighing device, the substrate is preferably a silicon substrate.
In this way, the formation of the first recess and the second recess can be performed with higher accuracy using the semiconductor device manufacturing technique.

The weighing device of the present invention is obtained by the method for manufacturing the weighing device.
According to this metering device, as described above, a predetermined amount of liquid is formed in a predetermined volume by injecting a predetermined amount of liquid into the independent recess of the second recess by an injector such as a micropipette. Overflowing from the independent recess can be arranged in the independent recess of the first recess communicating with the second recess. Therefore, by appropriately setting the volume of the independent concave portion of the second concave portion, it becomes possible to re-measure the liquid measured by the injector to a smaller amount. It becomes possible to carry out weighings that are even smaller than the minimum amount specified.

The mixing device of the present invention includes the weighing device, and a mixing unit that mixes the liquid supplied to the second concave portion of the weighing device and overflowed into the first concave portion with another liquid. It is characterized by having prepared.
According to this mixing device, as described above, the predetermined amount of liquid injected into the independent recess of the second recess of the metering device can be overflowed from the independent recess and disposed in the independent recess of the first recess. Therefore, by arranging another predetermined amount of liquid directly or indirectly in the mixing part, the plural kinds of liquids can be mixed at a desired mixing ratio by the mixing part.
Therefore, since a smaller amount can be measured especially by a weighing device, the minimum unit amount of the obtained mixed liquid is remarkably reduced as compared with the conventional one. It is possible to prepare a mixed solution using a small amount of specimen.

(A), (b) is a schematic block diagram of one Embodiment of the measuring device of this invention. (A)-(d) is explanatory drawing of the manufacturing method of the measuring apparatus shown in FIG. It is a top view which shows schematic structure of the mixing apparatus of this invention.

The present invention will be described in detail below.
First, the weighing device according to the present invention will be described. 1 (a) and 1 (b) are diagrams showing an embodiment of a weighing device according to the present invention, FIG. 1 (a) is a plan view of the weighing device, and FIG. 1 (b) is FIG. 1 (a). It is AA sectional view taken on the line.

  1A and 1B, reference numeral 1 denotes a weighing device. The weighing device 1 includes a silicon substrate 2, a first concave portion 3, a second concave portion 4, a third concave portion 5, 4, the fifth recess 7, the sixth recess 8, and the seventh recess 9 are formed.

  The first concave portion 3 is an elongated groove-shaped concave portion as shown in FIG. 1 (a), and as shown in FIGS. 1 (a) and 1 (b), the second concave portion is formed on the upper opening side 3a. 4, the third recess 5 and the sixth recess 8 communicate with each other. Further, the first recess 3 has the second recess 4, the third recess 5, and the lower side of the upper opening side 3 a communicating with the sixth recess 8, that is, the bottom side, the second recess 4, 3, the independent recess 3 b, independent of the third recess 6 and the sixth recess 8. Although the volume of the independent recess 3b is not particularly determined, the independent recess 3b is sufficiently larger than each of the independent recesses of the second recess 7 to the seventh recess 9 described later, and therefore deeper than these independent recesses. Is formed.

In contrast to the groove-shaped first recess 3, the second recess 4, the third recess 5, the fourth recess 6, the fifth recess 7, the sixth recess 8, and the seventh recess 9 are As shown in FIG. 1 (a), they are formed on both sides of the first recess 3, respectively, and thus are formed in two.
As shown in FIG. 1B, the upper side opening 4a of the second concave portion 4 communicates with the upper side opening 3a of the first concave portion 3, and the bottom portion as shown by a two-dot chain line in FIG. The side is an independent recess 4 b that is independent from the first recess 3. In the present embodiment, the independent recess 4b has a volume of 225 nl.
As for the 4th recessed part 6, the upper side opening 6a is connected to the upper side opening 4a of the 2nd recessed part 4, and the bottom part side became independent from the 2nd recessed part 4 as shown by the dashed-two dotted line in FIG.1 (b). It is an independent recess 6b. In this embodiment, the independent recess 6b has a volume of 150 nl.

Although the third recess 5 is not shown in the drawing, the upper side opening communicates with the upper side opening 3 a of the first recess 3 and the bottom side is independent from the first recess 3, similarly to the second recess 4. It is a recess. In this embodiment, the independent concave portion has a volume different from that of the independent concave portion 4b of the second concave portion 4, that is, 300 nl in the present embodiment.
Although not shown, the fifth recess 7 has an upper opening that communicates with the upper opening of the third recess 5 and a bottom that is an independent recess that is independent of the third recess 5. In this embodiment, the independent recess has a volume different from that of the independent recess of the third recess 5, and is 200 nl in this embodiment.

Although the sixth recess 8 is not shown, the upper opening is communicated with the upper opening 3 a of the first recess 3 and the bottom is independent from the first recess 3, similarly to the second recess 4. It is a recess. In this embodiment, the independent concave portion has a volume different from that of the independent concave portion 4b of the second concave portion 4, that is, 150 nl in the present embodiment.
Although the seventh recess 7 is not shown, the upper side opening communicates with the upper side opening of the sixth recess 8, and the bottom side is an independent recess independent of the sixth recess 8. In this embodiment, the independent recess has a volume different from that of the independent recess of the sixth recess 5, that is, 100 nl in this embodiment.

  In order to manufacture the weighing device 1 having such a configuration, first, a silicon substrate (silicon substrate) 2 is prepared, and then a resist film is formed on the upper surface thereof by a known method. Subsequently, the resist film is exposed using an exposure mask and further developed to be patterned, and a large number of square or circular openings (for example, several tens to several hundreds) are formed as shown in FIG. A resist mask 10 having the same is formed. However, for this resist mask 10, a plurality of types of masks having different opening diameters are used for each depth of the recess to be formed.

  That is, as shown in FIG. 2A, in the formation region 11 of the first recess 3, the resist mask 10a has a sufficiently large (wide) opening diameter. On the other hand, in the formation region 12 of the second recess 4, the resist mask 10b is formed with a smaller (narrower) opening diameter than the resist mask 10a. Further, in the formation region 13 of the fourth recess 6, the resist mask 10c is formed with a smaller (narrower) opening diameter than the resist mask 10b.

  Although not shown, the resist mask 10 has a larger (wider) opening diameter than the resist mask 10b in the formation region of the third recess 5, and the resist mask 10 has a resist pattern in the formation region of the fifth recess 7. The mask 10 is formed with a slightly smaller (narrower) opening diameter than the resist mask 10b. In the formation region of the sixth recess 8, the resist mask 10 is formed with the same opening diameter as the resist mask 10c. In the formation region of the seventh recess 9, the resist mask 10 is opened from the resist mask 10c. The aperture is small (narrow).

The size (width) of the opening diameter is appropriately determined by investigating the relationship between the etching conditions and the etching depth through experiments and simulations in advance.
Further, in each formation region from the first recess 3 to the seventh recess 9, the boundary between the adjacent recesses from the first recess 3 to the seventh recess 9 is on the upper opening side. However, the opening diameter is made sufficiently small (narrow) so as to be independent from each other on the bottom side. The opening diameter at the boundary is also determined appropriately by examining the relationship between the etching conditions and the etching depth in advance through experiments and simulations.

  In this way, the depth of each concave portion corresponds to the entire area from the formation region 11 of the first concave portion 3 to the formation region of the seventh concave portion 9 with respect to the substrate 2 and all the boundary portions thereof. Once the resist mask 10, that is, the resist mask 10 having an opening diameter corresponding to the depth to the independent recesses and the depth of the upper opening communicating with the recesses, the substrate is formed by dry etching such as reactive ion etching (RIE). Etch the upper surface side of 2 at once.

  Then, due to the microloading effect, at a certain point after the start of etching, the etching depth is small and the opening diameter is large in the formation region 13 where the opening diameter is small (narrow) as shown in FIG. In the deep formation region 11, the etching depth is deep. Further, in the formation region 12 in which the opening diameter is in the middle of these, the etching depth is also in the middle between the formation region 13 and the formation region 11.

  Then, as shown in FIG. 2B to FIG. 2D showing the etching states in the order of the etching time, the etching recess formed corresponding to each opening of the resist mask 10 becomes deeper as the etching time elapses. And spread laterally. Then, when a certain amount of time has passed, adjacent ones of the etching recesses corresponding to the openings of the resist mask 10 communicate with each other as shown in FIG. However, since the microloading effect continues, these etching recesses correspond to the respective opening diameters of the resist mask 10 as described above, and the depths of the formation region 13, the formation region 12, and the formation region 11 in this order. Is deeply formed.

  Further, by further etching, in the formation region of each recess, as shown in FIG. 1B, corresponding to each opening diameter of the resist mask 10, the recesses (3 4, 6) are formed. At that time, the opening diameter of the resist mask 10 is formed sufficiently small (narrow) so that adjacent recesses communicate with each other at the upper opening side and are independent from each other at the bottom side. Therefore, the depth is shallower than that of each of the recesses (3, 4, 6). Therefore, each concave part (3, 4, 6) communicates with the part 14 corresponding to this boundary part on the upper opening side (3a, 4a, 6a), and the adjacent parts communicate with each other on the bottom side. Independent recesses (3b, 4b, 6b) are formed.

  Therefore, each condition such as the opening diameter of the resist mask 10, the size (area) of the formation region of each recess (3-9), the etching time, and the depths of the independent recesses 3a-9a of each recess (3-9) The volume of each of the independent recesses 3a to 9a can be formed to the predetermined volume described above by performing an etching under the conditions set based on the above relationship.

  In order to measure an expensive reagent or a specimen such as blood using the measuring device 1 formed in this way, for example, a micropipette with a minimum injection volume of 150 nl is used, and a 150 nl sample measured with this micropipette is used. Liquid is injected into the fourth recess 6. Then, by repeating this operation three times, a total of 450 nl of liquid is injected into the fourth recess 6. Then, since the volume of the independent recess 6b of the fourth recess 6 is 150 nl, 300 nl obtained by subtracting 150 nl of the volume from the injection amount overflows from the independent recess 6 b and flows into the second recess 4.

Since the volume of the independent recess 4b of the second recess 4 is 225 nl, 75 nl obtained by subtracting 225 nl of the volume from the amount of the liquid that has flowed further flows into the first recess 3.
Therefore, by using a micro pipettor with a capacity of 150 nl and using the fourth recess 6 and the second recess 4 from now on, 75 nl, which is half of the capacity, can be measured into the first recess 3. . Therefore, the liquid in the 1st recessed part 3 is inhaled with another micropipette, and a desired liquid mixture can be prepared by inject | pouring with another liquid to the mixing apparatus prepared separately.

  Similarly, by using the third concave portion 5 or the fifth concave portion 7 to the seventh concave portion 9, and also using a micro pipetter having a different minimum injection amount at one time, the minimum injection amount of the micro pipetter is used. Smaller amounts can be easily weighed. At that time, by using a plurality of sets such as the second recess 4 and the fourth recess 6 that communicate with each other, various amounts can be measured. In addition, the liquid is directly injected into the second recess 4, the third recess 5, and the sixth recess 8 that communicate directly with the first recess 3, and overflows from these independent recesses so that the first recess 3. A desired amount may be measured inside.

Next, a mixing device using such a weighing device 1 will be described.
FIG. 3 is a plan view showing an embodiment of the mixing apparatus of the present invention, and 20 in FIG. 3 is a mixing apparatus. The mixing device 20 includes a weighing device 1 formed on the substrate 2 shown in FIGS. 1A and 1B, and a mixing unit 21 formed on the substrate 2.

  In the present embodiment, the mixing unit 21 includes a recess that communicates with the first recess 3 and functions as a liquid pool. In the present embodiment, the first recess 3 is formed such that the bottom surface of the independent recess 3b is inclined. That is, the bottom surface of the independent recess 3b of the first recess 3 is inclined so as to become lower from the second recess 4 side shown in FIG. 1A toward the sixth recess 8 side. And the said mixing part 21 is formed and arrange | positioned on the extension line, The depth of this mixing part 21 is deeper than the said independent recessed part 3b. Note that the inclination of the bottom surface of the independent recess 3 b can be reduced by appropriately changing the opening diameter of the resist mask 10 shown in FIG. 2A in the formation region 11 of the first recess 3. It can be formed by a loading effect.

  In order to mix the first liquid and the second liquid using the mixing device 20, first, the second liquid 7 to the seventh concave portion 9 of the metering device 1 are used, and the first liquid is desired. A small amount is weighed into the first recess 3. Then, the weighed first liquid flows in the independent recess 3 b of the first recess 3 and flows down to the mixing unit 21. Separately, the desired amount of the second liquid is measured using the measuring device 1. Then, the second liquid also flows down to the mixing unit 21 through the first recess 3. Therefore, the first liquid and the second liquid prepared in a desired amount (a very small amount) can be guided to the mixing unit 21 and mixed there.

When the amount of the second liquid is relatively large, the second liquid may be directly injected into the first recess 3 or the mixing unit 21 from the micropipette.
Moreover, about the liquid used for mixing, it is needless to say that it may be three or more types without being limited to two types.

In such a mixing device 20, a predetermined amount of liquid injected into the independent recesses such as the second recess 4 of the measuring device 1 overflows from the independent recesses to the independent recesses 3 b of the first recess 3. Therefore, by mixing another predetermined amount of liquid directly or indirectly in the mixing unit 21, the mixing unit 21 can mix the plurality of types of liquids at a desired mixing ratio. it can.
Therefore, since a smaller amount can be measured especially by a weighing device, the minimum unit amount of the obtained mixed liquid is remarkably reduced as compared with the conventional one. It is possible to prepare a mixed solution using a small amount of specimen.

In the above-described embodiment, the mixing unit 21 is configured by only the concave portion, but the present invention is not limited to this, and a mixing unit having various configurations can be employed. For example, instead of the mixing unit 21 shown in FIG. 3, a mixing unit using a pump made of a piezoelectric element as described in JP-A-2005-131556 may be used.
Specifically, a pump made of the above-described piezoelectric element is arranged upstream of the mixing unit 21 shown in FIG. 3, and the liquid in the independent recess 3 b of the first recess 3 is forcibly sucked, and the recess ( It can flow into the mixing part 21). In that case, it is possible to eliminate the inclination of the bottom surface of the independent recess 3b of the first recess 3 and to form it substantially horizontally.

  Moreover, about the measuring device 1 shown to Fig.1 (a), (b), the 1st recessed part 3 is prescribed | regulated as the mixing part in this invention, and the 2nd recessed part 4 (or 3rd recessed part 5, 6th) is defined. By defining the concave portion 8) as the first concave portion in the present invention and the fourth concave portion 6 (or the fifth concave portion 7 and the seventh concave portion 9) as the second concave portion in the present invention, The weighing device 1 can be used as it is as the mixing device of the present invention.

  That is, the first liquid is injected into the fourth recess 6 (or the fifth recess 7 or the seventh recess 9) defined as the second recess, overflows the first liquid, and the first liquid is measured in a minute amount. The liquid is allowed to flow into the second recess 4 (or the third recess 5 or the sixth recess 8) defined as the first recess. Then, the first liquid that has flowed into the second concave portion 4 (or the third concave portion 5 and the sixth concave portion 8) and the second liquid supplied separately from the first liquid are defined as a mixing portion. Guide into the recess 3 and mix here. About the 2nd liquid, you may make it inject | pour into a mixing part (1st recessed part 3) directly with a micropipette etc. FIG.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, although the silicon substrate is used as the substrate 2 in the embodiment, for example, a glass substrate can also be used.

  DESCRIPTION OF SYMBOLS 1 ... Metering device, 2 ... Substrate (silicon substrate), 3 ... 1st recessed part, 3a ... Upper opening side, 3b ... Independent recessed part, 4 ... 2nd recessed part, 4a ... Upper opening side, 4b ... Independent recessed part, 5 3rd recessed part, 5a ... Upper opening side, 5b ... Independent recessed part, 6 ... 4th recessed part, 6a ... Upper opening side, 6b ... Independent recessed part, 7 ... 5th recessed part, 7a ... Upper opening side, 7b ... Independent concave portion, 8 ... sixth concave portion, 8a ... upper opening side, 8b ... independent concave portion, 9 ... seventh concave portion, 9a ... upper opening side, 9b ... independent concave portion, 10, 10a, 10b, 10c ... resist mask ( Mask), 20 ... mixing device, 21 ... mixing unit

Claims (7)

The substrate has at least a first recess and a second recess having a shallower depth than the first recess, and the first recess and the second recess communicate with each other on the upper opening side; and In manufacturing a liquid metering device having independent recesses independent from each other on the bottom side, and the volume of the independent recesses of the second recess is a predetermined volume,
Using a plurality of types of masks having different opening diameters, dry etching is collectively performed on the substrate, and at least the first concave portion and the second concave portion are formed in the substrate using a microloading effect. A method of manufacturing a weighing device.   2. The weighing apparatus according to claim 1, wherein a plurality of the second recesses are formed for one of the first recesses by performing dry etching collectively using a plurality of types of masks. Manufacturing method.   By performing dry etching collectively using a plurality of types of masks, a third recess having an independent recess independent from each other on the bottom side and communicating with one of the first recesses The measuring device according to claim 1 or 2, wherein the independent concave portion of the third concave portion is formed in a predetermined volume different from the independent concave portion of the second concave portion. Production method.   By performing dry etching collectively using a plurality of types of masks, a fourth recess having an independent recess independent from each other on the bottom side and communicating with one of the second recesses on the upper opening side The method for manufacturing a weighing device according to any one of claims 1 to 3, wherein the independent concave portion of the fourth concave portion is formed in a predetermined volume.   The method for manufacturing a weighing device according to any one of claims 1 to 4, wherein the substrate is a silicon substrate.   A weighing device obtained by the method of manufacturing a weighing device according to any one of claims 1 to 5.   7. A weighing device according to claim 6, and a mixing unit that mixes the liquid that has been supplied to the second recess of the weighing device and overflowed into the first recess with another liquid. A mixing device characterized by.

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