JP2019154339A - Droplet formation head, droplet formation device and droplet formation method - Google Patents

Abstract

To provide a droplet formation head capable of forming droplets including one particle having settleability for one discharge.SOLUTION: A droplet formation head comprises: a first liquid storage part capable of storing a particle suspension in which particles having settleability are suspended, and comprising on a bottom part thereof, a supply port for supplying the particle suspension; a second liquid storage part for storing therein, the supply port of the first liquid storage part, comprising on a bottom part thereof, a discharge hole, and capable of storing a liquid; and discharge means for discharging the particle suspension with the liquid from the discharge hole, as a droplet.SELECTED DRAWING: Figure 3C

Description

  The present invention relates to a droplet forming head, a droplet forming apparatus, and a droplet forming method.

  In recent years, with the development of stem cell technology, technology development has been carried out to form a tissue body by ejecting a plurality of cells by an ink jet method.

  Examples of the ink jet system include a piezoelectric pressure system using a piezoelectric element, a thermal system using a heater, and an electrostatic system that pulls liquid by electrostatic attraction. Among these, the piezoelectric pressurization method is suitable for use in forming droplets of a cell solution because it is less likely to damage cells due to heat and electric field than other methods.

  For this reason, various droplet forming apparatuses using a piezoelectric pressurization method have been proposed (for example, see Patent Documents 1 and 2).

  An object of the present invention is to provide a droplet forming head capable of forming a droplet including one settling particle per discharge.

  The droplet forming head of the present invention as means for solving the problems is capable of containing a particle suspension in which sedimentation particles are suspended, and has a supply port for supplying the particle suspension at the bottom. 1 liquid storage part, the 2nd liquid storage part which accommodates the said supply port of the said 1st liquid storage part inside, has a discharge hole in the bottom part, and can store a liquid, and the said particle | grain suspension Discharge means for discharging the liquid together with the liquid from the discharge hole.

  ADVANTAGE OF THE INVENTION According to this invention, the droplet formation head which can form the droplet containing one sedimentation particle | grain per discharge can be provided.

FIG. 1 is a cross-sectional view illustrating a droplet forming head according to the first embodiment. FIG. 2 is an explanatory diagram illustrating the voltage applied to the piezoelectric element. FIG. 3A is an explanatory diagram illustrating a process in which droplets are formed by the droplet forming head according to the first embodiment. FIG. 3B is an explanatory diagram illustrating a process in which droplets are formed by the droplet forming head according to the first embodiment. FIG. 3C is an explanatory diagram illustrating a process in which droplets are formed by the droplet forming head according to the first embodiment. FIG. 4A is a cross-sectional view illustrating a height adjustment mechanism according to the second embodiment. FIG. 4B is a side view illustrating the height adjustment mechanism according to the second embodiment. FIG. 5 is a cross-sectional view illustrating a position adjustment mechanism according to the third embodiment. FIG. 6 is a cross-sectional view illustrating a pressure mechanism according to the fourth embodiment. FIG. 7 is a cross-sectional view illustrating another pressure mechanism according to the fourth embodiment. FIG. 8 is a cross-sectional view illustrating a negative pressure mechanism according to the fifth embodiment.

(Droplet forming head)
The droplet forming head of the present invention is capable of storing a particle suspension in which sedimentation particles are suspended, and includes a first liquid storage unit having a supply port for supplying the particle suspension at the bottom, A second liquid storage section that houses the supply port of the liquid storage section, has a discharge hole at the bottom, and can store the liquid, and discharge means for discharging the particle suspension together with the liquid as droplets from the discharge hole And, if necessary, other means.

In the droplet forming head of the present invention, in the conventional droplet forming apparatus, since the sedimentation particles settle, the nozzle density is concerned and the particle density cannot be increased. This is based on the knowledge that there was a problem that sometimes it was not included.
In the droplet forming head according to the present invention, when cells are used as the sedimenting particles in the conventional droplet forming apparatus, the settled cells may aggregate and adhere to the inside, so that it takes time and effort to wash. This is also based on the knowledge that there was a problem that the cells had to be discarded.

  In the droplet forming head of the present invention, the particle suspension in which the sedimentary particles are suspended is accommodated in the first liquid accommodating portion, and the supply port of the first liquid accommodating portion is disposed in the vicinity of the discharge hole (nozzle). Has been. For this reason, when the droplet forming head of the present invention discharges droplets from the nozzle, together with the liquid stored in the second liquid storage unit, the particle suspension stored in the first liquid storage unit is also accompanied. Sedimentable particles can be discharged together more reliably. Further, in the droplet forming head of the present invention, since the sedimentary particles advect and do not diffuse in the second liquid storage portion, the sedimentation particles settle and settle together in the second liquid storage portion. In addition, the sedimentation particles are not wasted.

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant description may be omitted. In addition, here, an example is given for the discharge of a cell solution in which cells as sedimentation particles are suspended, but the present invention may be applied to ejection of a particle suspension in which sedimentation particles are suspended in other fields.

(First embodiment)
[Structure of droplet forming head]
A droplet forming head according to the first embodiment will be described.
FIG. 1 is a sectional view showing an example of a droplet forming head according to the first embodiment.
As shown in FIG. 1, a droplet forming head 100 includes a first liquid chamber 1 as a first liquid storage portion, a second liquid chamber 2 as a second liquid storage portion, and a film-like member. The membrane 3, the piezoelectric element 4 as a part of the discharge means, and the holding means 5.
In the present embodiment, for the sake of convenience, the side of the first liquid chamber 1 and the second liquid chamber 2 where the liquid surface exists is the upper side, and the side where the piezoelectric element 4 is present is the lower side. Moreover, in each part, let the surface where the 1st liquid chamber 1 and the 2nd liquid chamber 2 exist be an upper surface, and let the surface where the piezoelectric element 4 exists be a lower surface.

The first liquid chamber 1 accommodates a cell solution A in which cells P are suspended as a particle suspension in which sedimentation particles are suspended.
The structure of the first liquid chamber 1 is not particularly limited as long as the cell solution A can be accommodated and the supply port 1a for supplying the cell solution A is provided at the bottom, and is appropriately selected according to the purpose. Can do. Further, as shown in FIG. 1, the first liquid chamber 1 supplies the inner diameter of the portion above the supply port 1a of the first liquid chamber 1 so that a predetermined amount of the cell solution A can be accommodated. You may make it larger than the internal diameter of the opening | mouth 1a.
Examples of the material of the first liquid chamber 1 include metal, silicon, and ceramic.
There is no restriction | limiting in particular as a magnitude | size of the 1st liquid chamber 1, According to the objective, it can select suitably.

The supply port 1 a is accommodated in the second liquid chamber 2.
There is no restriction | limiting in particular as an internal diameter of the supply port 1a, Although it can select suitably according to the objective, It is preferable that it is comparable as the diameter of the discharge hole 3a mentioned later.
The position of the supply port 1a when accommodated in the second liquid chamber 2 is preferably arranged in the vicinity so as not to contact the discharge hole 3a from the viewpoint of not inhibiting the vibration of the discharge hole 3a. .

  The cell solution A includes cells P and a cell dispersion, and further includes other components as necessary.

  There is no restriction | limiting in particular as the cell P, According to the objective, it can select suitably, For example, an animal cell, especially a human origin cell etc. are mentioned.

The cell dispersion can be used without particular limitation as long as it is a cell culture medium usually used in the technical field. For example, depending on the type of cell P used, MEM medium, BME medium, DME medium, αMEM medium , IMDM medium, ES medium, DM-160 medium, Fisher medium, F12 medium, WE medium, RPMI1640 medium, and the like, which are described in p581 of "Tissue Culture Technology Third Edition" published by Asakura Shoten. Examples include a medium.
As a main component of the cell dispersion, water having high affinity with the cell P is preferable. Further, the cell dispersion preferably contains a salt for adjusting the osmotic pressure with the cell P and a pH adjusting agent for adjusting the pH. More specifically, a Tris buffer aqueous solution adjusted in pH or a PBS solution added with a metal salt such as Ca, K, Na, or the like equivalent to the culture solution can be used as the cell dispersion.
In addition, serum (such as fetal bovine serum), various growth factors, antibiotics, amino acids and the like may be added to the basal medium. A commercially available serum-free medium such as Gibco serum-free medium (Invitrogen) can also be used. In consideration of clinical application of the finally obtained cell tissue, it is preferable to use a medium that does not contain animal-derived components.

The second liquid chamber 2 has a membrane 3 at the bottom, and stores the supply port 1a of the first liquid chamber 1 and the liquid B therein.
There is no restriction | limiting in particular as the liquid B, According to the objective, it can select suitably, For example, the cell dispersion liquid mentioned above etc. are mentioned.
There is no restriction | limiting in particular as a material of the 2nd liquid chamber 2, It can select suitably according to the objective, For example, the material similar to the material of the 1st liquid chamber 1 is mentioned.

  The membrane 3 is disposed as the bottom of the second liquid chamber 2 and is fixed to the end of the lower surface of the second liquid chamber 2. A discharge hole 3a, which is a through hole, is formed at substantially the center of the membrane 3, and the cell solution A stored in the first liquid chamber 1 together with the liquid stored in the second liquid chamber 2 3 is ejected as droplets from the ejection hole 3a.

  The shape of the membrane 3 when viewed in plan is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a circle, an ellipse, and a rectangle. The shape of the bottom of the second liquid chamber 2 The one according to is preferable.

There is no restriction | limiting in particular as a material of the membrane 3, According to the objective, it can select suitably, For example, a metal, a ceramic, a polymeric material with a certain amount of hardness, etc. are mentioned. Among these, a material having low adhesion to the cell P is preferable.
Examples of the material having low adhesion to the cell P include a material having high hydrophilicity and a material having high hydrophobicity.
Examples of the highly hydrophilic material include a metal material and a ceramic material. In addition to this, as a highly hydrophilic material, for example, a surface coated with a metal material or a ceramic material, a surface coated with a synthetic phospholipid polymer imitating a cell membrane (for example, Lipidure manufactured by NOF Corporation). Things.
Examples of the metal material include stainless steel, nickel, and aluminum.
Examples of the ceramic material include silicon dioxide, alumina, zirconia, and the like.
Examples of the highly hydrophobic material include a fluororesin.

In the present embodiment, the discharge hole 3a is formed in a substantially circular shape substantially at the center of the membrane 3.
There is no restriction | limiting in particular as a shape of the discharge hole 3a, According to the objective, it can select suitably, For example, a perfect circle shape etc. are mentioned.
When the shape of the discharge hole 3a is a perfect circle, the upper limit value of the diameter of the discharge hole 3a is preferably 200 μm or less. If the upper limit value of the diameter of the discharge hole 3a is 200 μm or less, it is advantageous in that the droplets do not become too large and it is easy to form microdroplets. Moreover, as a lower limit value of the diameter of the discharge hole 3a, since the volume average particle diameter of animal cells, particularly human cells, as sedimentary particles is about 10 μm or more and 30 μm or less, the cells are prevented from clogging the discharge holes 3a. From the point of view, it is preferable that the volume average particle diameter of the cells is twice or more. Then, the lower limit value of the diameter of the discharge hole 3a is preferably 20 μm or more. Therefore, the diameter of the discharge hole 3a is preferably 20 μm or more and 200 μm or less.

As a volume average particle diameter of a cell, it can measure with the following measuring method, for example.
By removing 10 μL from the cell solution A and placing it on a PMMA plastic slide, the volume average particle diameter can be measured by using an automatic cell counter (Countess Automated Cell Counter, manufactured by Invitrogen). The number of cells can also be determined by the same measurement method.

The piezoelectric element 4 is disposed on the lower surface side of the membrane 3.
The shape of the piezoelectric element 4 is preferably a shape that matches the shape of the membrane 3. For example, when the shape of the membrane 3 when viewed from above is circular, it is preferable to dispose the annular (ring-shaped) piezoelectric element 4 having a planar shape around the discharge hole 3a.

The piezoelectric element 4 has, for example, a structure in which electrodes for applying a voltage are provided on the upper surface and the lower surface of a piezoelectric material. By applying a voltage to the upper and lower electrodes of the piezoelectric element 4, a compressive stress is applied in the lateral direction of the paper surface, and the membrane 3 can be vibrated.
Examples of the piezoelectric material include lead zirconate titanate, bismuth iron oxide, metal niobate, barium titanate, and materials obtained by adding metals or different oxides to these.

  In the present embodiment, the piezoelectric element 4 vibrates the membrane 3. However, the present invention is not limited to this, and other modes may be employed. As another aspect, for example, a material having a linear expansion coefficient different from that of the membrane 3 may be pasted on the membrane 3 and heated to vibrate the membrane 3 using the difference in linear expansion coefficient. In the case of this aspect, it is preferable to arrange a heater in the vicinity of materials having different linear expansion coefficients and vibrate the membrane 3 by turning the heater on / off.

As shown in FIG. 1, the holding means 5 has a rod-like member 5a and a connector 5b.
The rod-shaped member 5a has a structure that can be detachably attached to the peripheral edge of the second liquid chamber 2 at one end, and a connector 5b is connected to the other end.
The connector 5b can hold the first liquid chamber 1 fixedly.
Therefore, the first liquid chamber 1 can be detached from the second liquid chamber 2 by the holding means 5. When the first liquid chamber 1 is detachable from the second liquid chamber 2, maintenance and maintenance of the droplet forming head 100 are facilitated.

[Drop formation process (operation) by the drop forming head]
A process in which the droplet forming head according to the first embodiment forms droplets will be described.
FIG. 2 is an explanatory diagram illustrating the voltage applied to the piezoelectric element. 3A to 3C are explanatory diagrams illustrating a process of forming droplets by the droplet forming head according to the first embodiment.
When the pulsed voltage shown in FIG. 2 is applied to the upper and lower electrodes of the piezoelectric element 4, a droplet D can be formed as shown in FIGS. 3A to 3C.

First, at the rising time of the applied voltage indicated by t1 in FIG. 2, the membrane 3 is rapidly deformed as shown in FIG. 3A, so that the liquid B accommodated in the second liquid chamber 2 and the membrane 3 are deformed. A high pressure is generated, and the liquid contained in the second liquid chamber 2 is pushed out from the nozzle by this pressure. At this time, in the vicinity of the discharge hole 3a, the viscous force defined by the product of the viscosity and the flow velocity gradient in the second liquid chamber 2 acts on the cell solution A in the first liquid chamber 1, and the second Along with the liquid B accommodated in the liquid chamber 2, the cell solution A containing the cells P accommodated in the first liquid chamber 1 is also pushed out together.
Moreover, it is preferable that the viscosity of the liquid B is higher than the viscosity of the cell solution A in that the cell solution A is easily entrained in the liquid B. Thereby, the droplet forming head according to the first embodiment can easily discharge one cell per discharge.

  Next, as shown by t2 in FIG. 2, when the constant voltage is applied to the piezoelectric element 4, as shown in FIG. 3B, the time until the generated pressure is relaxed upward, the liquid is discharged from the discharge hole 3a. The state of pushing out continues and the droplet D grows.

  In the fall time of the applied voltage indicated by t3 in FIG. 2, as shown in FIG. 3C, the fluid pressure near the interface between the cell solution A and the membrane 3 decreases when the membrane 3 returns to the original state. Then, a droplet D containing cells P is formed. At this time, the cell solution A containing the cells P accommodated in the first liquid chamber 1 is moved downwards in order to fill substantially the same volume as the droplet D at the same time as the droplet D is discharged. The next droplet can be formed.

  As described above, the droplet forming head 100 can continuously form the droplet D as shown in FIG. 3C by continuously applying the pulse voltage shown in FIG. 2 to the piezoelectric element 4. .

In the droplet forming head 100, bubbles may be mixed in the cell solution A containing the cells P stored in the first liquid chamber 1 or the liquid stored in the second liquid chamber 2. In this case, since the droplet forming head 100 has a gas-liquid interface above the first liquid chamber 1 and the second liquid chamber 2, the bubbles rise upward due to the difference in specific gravity of the liquid or cell solution A, Finally, it is discharged into the gas phase. Even in the case where the diameter of the bubbles is small and the bubbles are attached to the inner walls of the first liquid chamber 1 or the second liquid chamber 2 and are not easily discharged to the gas phase, the first liquid is vibrated by the vibration of the membrane 3 by the piezoelectric element 4. Since the inner walls of the chamber 1 and the second liquid chamber 2 also vibrate, the bubbles leave the inner wall and are discharged into the gas phase.
For this reason, for the purpose of efficiently eliminating bubbles, the membrane 3 is vibrated at a timing when droplets are not formed, and the bubbles are actively moved to the gas phase above the first liquid chamber 1 and the second liquid chamber 2. You may make it discharge | emit.

  As described above, the droplet forming head 100 according to the present embodiment has the first liquid chamber 1 having the supply port 1a for supplying the cell solution A at the bottom, the discharge hole 3a at the bottom, and the liquid B inside. And a second liquid chamber 2 capable of accommodating the supply port 1a, and discharge means for discharging the cell solution A together with the liquid B. Thereby, the droplet forming head 100 according to the present embodiment can form a droplet including one settling particle per discharge.

(Second Embodiment)
The droplet forming head of the second embodiment further includes a height adjusting mechanism that can adjust the height of the first liquid chamber 1 in addition to the droplet forming head of the first embodiment. Here, the height adjustment mechanism will be described.

FIG. 4A is a cross-sectional view illustrating a height adjustment mechanism according to the second embodiment. FIG. 4B is a side view illustrating the height adjustment mechanism according to the second embodiment.
As shown in FIGS. 4A and 4B, in the second embodiment, in the droplet forming head 100 of the first embodiment, the first liquid chamber 1 is provided with a screw portion 1b, and the connector 5b is a connector with a screw receiver. By changing to 5c, the height adjustment mechanism which can adjust the height of the 1st liquid chamber 1 is comprised.
For example, when the supply port 1a of the first liquid chamber 1 is too far away from the discharge hole 3a in the height direction, the supply port 1a is brought closer to the discharge hole 3a by the height adjusting mechanism. Thereby, the droplet forming head 100 is likely to generate a high pressure between the liquid B accommodated in the second liquid chamber 2 and the membrane 3 when the membrane 3 is deformed. For this reason, in the droplet discharge, the cell solution A accommodated in the first liquid chamber 1 is easily accompanied, and the droplet D containing the cells P can be formed more reliably. Further, when the first liquid chamber 1 is maintained or maintained, the supply port 1a can be separated from the discharge hole 3a.

  As described above, the droplet forming head 100 according to the second embodiment adjusts the relative height between the supply port 1a and the discharge hole 3a of the first liquid chamber 1 by having the height adjusting mechanism. By doing so, the cell solution A accommodated in the first liquid chamber 1 is likely to be accompanied, and the droplet D containing the cells P can be formed more reliably.

(Third embodiment)
The droplet forming head of the third embodiment further includes a position adjusting mechanism capable of adjusting the horizontal position of the first liquid chamber 1 in addition to the droplet forming head of the second embodiment. Here, the position adjusting mechanism will be described.

FIG. 5 is a cross-sectional view illustrating a position adjustment mechanism according to the third embodiment.
As shown in FIG. 5, in the third embodiment, in the droplet forming head 100 of the second embodiment, the sliding members 5d and 5e are provided on the rod-like member 5a, whereby the first liquid chamber 1 is horizontal. A position adjusting mechanism capable of adjusting the position of the direction is configured.
For example, when the center of the supply port 1a of the first liquid chamber 1 is not on the central axis of the discharge hole 3a, the sliding members 5d and 5e are slid in the direction indicated by S1 in FIG. The center is aligned with the central axis of the discharge hole 3a. Accordingly, the droplet forming head 100 is likely to be accompanied by the cell solution A stored in the first liquid chamber 1 when the membrane 3 is deformed, and more reliably forms the droplet D containing the cells P. Can do.

  As described above, the droplet forming head 100 according to the third embodiment has the position adjusting mechanism, and thereby aligns the center of the supply port 1a with the central axis of the discharge hole 3a, thereby allowing the first liquid chamber 1 to be aligned. The cell solution A accommodated in the cell is easily entrained, and the droplet D containing the cell P can be formed more reliably.

(Fourth embodiment)
The droplet forming head of the fourth embodiment further includes a pressurizing mechanism in the first liquid chamber 1 of the droplet forming head of any one of the first to third embodiments. Here, the pressurizing mechanism will be described.

FIG. 6 is a cross-sectional view illustrating a pressure mechanism according to the fourth embodiment.
As shown in FIG. 6, in the fourth embodiment, in the first liquid chamber 1 of the droplet forming head of any one of the first to third embodiments, a cylinder 6 is provided in the upper part, and the first liquid chamber A pressurizing mechanism that enables pressurization of the chamber 1 is configured.
For example, when the viscosity of the cell solution A accommodated in the first liquid chamber 1 is high and it is difficult for the cells P to be accompanied by the supply port 1 a, the first liquid chamber 1 is pressurized by the control of the cylinder 6. Thereby, the droplet forming head 100 according to the fourth embodiment is likely to be accompanied by the cell solution A accommodated in the first liquid chamber 1, and more reliably forms the droplet D containing the cells P. Can do.
In addition, when one cell is targeted for one discharge, when the viscosity of the cell solution A is low and a plurality of cells P are entrained from the supply port 1a, after the first liquid chamber 1 is pressurized by the control of the cylinder 6, Lightly depressurize. Accordingly, the droplet forming head 100 according to the fourth embodiment can suppress the cell solution A stored in the first liquid chamber 1 from being accompanied too much during the droplet discharge, and thus is easily accompanied by a single. Thus, the droplet D containing the cell P can be formed more reliably.

In the fourth embodiment, the cylinder 6 is used as the pressurizing mechanism. However, the present invention is not limited to this, and the cylinder 6 may be changed to a pump 7 as shown in FIG. In this case, a sensor (not shown) that measures the pressure inside the first liquid chamber 1 and a control circuit or device that feeds back based on the measured value from the sensor and the pressure setting value of the pump 7 may be included. .
In the first embodiment, the membrane 3 and the piezoelectric element 4 are used as the discharge means. However, the present invention is not limited to this, and the cylinder 6 or the pump 7 may be used as the discharge means.

(Fifth embodiment)
In the droplet forming head of the fifth embodiment, the holding means 5 is changed to the negative pressure mechanism 8 in the droplet forming head of the first embodiment. Here, the negative pressure mechanism 8 will be described.

FIG. 8 is a cross-sectional view illustrating a negative pressure mechanism according to the fifth embodiment.
As shown in FIG. 8, the negative pressure mechanism 8 of the fifth embodiment includes a lid 8a, an O-ring 8b, an opening / closing part 8c, and a vent 8d.
The lid 8a is arranged so as to cover the second liquid chamber 2, and holds the first liquid chamber 1 through an O-ring 8b at the center thereof. In addition, the lid 8a is provided with a vent 8d and an opening / closing portion 8c that slides in the direction indicated by S2 in FIG. 8 so that the vent 8d can be opened and closed.
Thereby, the negative pressure mechanism 8 can make the 2nd liquid chamber 2 a negative pressure by sealing the upper part of the 2nd liquid chamber 2. FIG. For this reason, it becomes difficult to supply the liquid B from the second liquid chamber 2 in the droplet discharge, so that the cell solution A stored in the first liquid chamber 1 is easily supplied, and the cells P are more reliably removed. A droplet D containing can be formed.
Further, the negative pressure mechanism 8 can open the inside of the second liquid chamber 2 in a negative pressure by opening the opening / closing part 8d.

When performing maintenance / maintenance such as removing the first liquid chamber 1 and cleaning the droplet forming head 100, the second liquid chamber 2 is hermetically sealed so that it is accommodated in the first liquid chamber 1. There is a possibility that the cell solution A that has been flown into the second liquid chamber 2. In this case, by opening the opening / closing part 8d and releasing the sealing of the second liquid chamber 2, it is possible to avoid the cell solution A from flowing into the second liquid chamber 2, and waste the cells P. There is no.
In the fifth embodiment, the O-ring is arranged between the first liquid chamber 1 and the lid 8a to increase the sealing degree. However, the present invention is not limited to this. For example, the second liquid chamber 2 A sealing member or the like may be disposed between the lid 8a and the lid 8a.

(Droplet forming device)
The droplet forming apparatus includes the above-described droplet forming head, and further includes other means as necessary.
Other means are not particularly limited and may be appropriately selected according to the purpose. However, a scanning mechanism capable of scanning the droplet forming head with three axes, and a discharge direction adjustment capable of adjusting the discharge direction with three axes. A mechanism is preferred. When the droplet forming apparatus has a scanning mechanism and a discharge direction adjusting mechanism, it is advantageous in that patterning discharge on a flat surface is possible. Further, in this case, it is advantageous in that three-dimensional modeling can be performed by discharging the patterning so as to be laminated.

  As described above, the droplet forming head of the present invention can store a particle suspension in which sedimentation particles are suspended, and includes a first liquid storage that includes a supply port for supplying the particle suspension at the bottom. And a second liquid storage part that has a discharge hole at the bottom and can store a liquid, and a particle suspension together with the liquid from the discharge hole. Discharge means for discharging as droplets. Thereby, the droplet forming head of the present invention can form a droplet including one sedimentary particle per discharge.

  Note that the droplet forming head of the present invention has been described by taking an example in which droplets containing one cell per discharge can be formed. However, the present invention is not limited to this. For example, in an internal combustion engine, The present invention can also be applied to a fuel injection device that injects fuel containing a combustion accelerator.

As an aspect of this invention, it is as follows, for example.
<1> a first liquid storage unit capable of storing a particle suspension in which sedimentation particles are suspended, and having a supply port for supplying the particle suspension at the bottom;
A second liquid storage portion that houses the supply port of the first liquid storage portion, has a discharge hole at the bottom, and can store a liquid;
Discharge means for discharging the particle suspension together with the liquid as droplets from the discharge hole;
A droplet forming head characterized by comprising:
<2> The droplet forming head according to <1>, wherein the discharge unit pressurizes the particle suspension to discharge the particle suspension together with the liquid as droplets from the discharge hole. .
<3> The discharge hole is disposed in the film member,
The droplet forming head according to <1>, wherein the discharge unit discharges the particle suspension together with the liquid as droplets from the discharge hole by vibrating the film-like member.
<4> The droplet forming head according to any one of <1> to <3>, wherein the first liquid storage unit includes a pressurizing mechanism that pressurizes the particle suspension.
<5> The droplet forming head according to any one of <1> to <4>, wherein the first liquid storage unit is detachable from the second liquid storage unit.
<6> The droplet formation according to any one of <1> to <5>, wherein the first liquid storage unit includes a height adjusting mechanism capable of adjusting a height from the supply port to the discharge hole. Head.
<7> The droplet forming head according to any one of <1> to <6>, wherein the first liquid storage unit includes a position adjusting mechanism capable of adjusting a position in a horizontal direction.
<8> The droplet forming head according to any one of <1> to <7>, wherein the second liquid storage unit includes a negative pressure mechanism that makes a negative pressure inside.
<9> A droplet forming apparatus having the droplet forming head according to any one of <1> to <8>.
<10> A first liquid storage unit capable of storing a particle suspension in which sedimentation particles are suspended, and having a supply port for supplying the particle suspension at the bottom;
Using a droplet forming head having the supply port of the first liquid storage unit therein, a discharge hole at the bottom, and a second liquid storage unit capable of storing a liquid,
Discharge for storing the particle suspension in the first liquid storage unit, storing the liquid in the second liquid storage unit, and discharging the particle suspension together with the liquid as droplets from the discharge hole A droplet forming method including a step.
<11> The droplet forming method according to <10>, wherein the liquid has a higher viscosity than the particle suspension.
<12> The discharge step according to any one of <10> to <11>, wherein the particle suspension is pressurized as the liquid droplets from the discharge holes together with the liquid by pressurizing the particle suspension. This is a droplet forming method.
<13> In the discharge step, the particle suspension is discharged as droplets from the discharge holes together with the liquid by vibrating the film-like member in which the discharge holes are arranged. <10> to <11 > A droplet forming method according to any one of the above.
<14> The droplet forming method according to any one of <10> to <13>, wherein the particle suspension is pressurized by a pressurizing mechanism included in the first liquid storage unit.
<15> The droplet forming method according to any one of <10> to <14>, wherein the negative pressure mechanism included in the second liquid container includes a negative pressure inside the first liquid container. is there.

  The droplet forming head according to any one of <1> to <8>, the droplet forming apparatus according to <9>, and the droplet forming method according to any one of <10> to <15>. According to this, the above-mentioned problems can be solved and the object of the present invention can be achieved.

Japanese Translation of National Publication No. 07-501481 JP 2017-083439 A

1 1st liquid chamber (1st liquid storage part)
1b Screw part (part of the height adjustment mechanism)
2 Second liquid chamber (second liquid container)
3 Membrane (membrane-like member, part of discharge means)
3a Discharge hole 4 Piezoelectric element (part of discharge means)
5 Holding means 5a Bar-shaped member 5b Connector 5c Connector with screw receiver (part of height adjustment mechanism)
5d, 5e Sliding member (part of position adjustment mechanism)
6 Cylinder (an example of a pressure mechanism)
7 Pump (Example of pressurizing mechanism)
8 Negative pressure mechanism 8a Lid 8b O-ring 8c Opening / closing part 8d Vent 100 Droplet forming head D Droplet P cell (sedimentable particle)

Claims (11)

A first liquid storage unit capable of storing a particle suspension in which settling particles are suspended, and having a supply port for supplying the particle suspension at the bottom;
A second liquid storage portion that houses the supply port of the first liquid storage portion, has a discharge hole at the bottom, and can store a liquid;
Discharge means for discharging the particle suspension together with the liquid as droplets from the discharge hole;
A droplet forming head comprising:   The droplet forming head according to claim 1, wherein the discharge unit pressurizes the particle suspension to discharge the particle suspension together with the liquid as droplets from the discharge hole. The discharge hole is disposed in the film-like member;
The droplet forming head according to claim 1, wherein the ejection unit ejects the particle suspension together with the liquid as droplets from the ejection hole by vibrating the film-like member.   4. The droplet forming head according to claim 1, wherein the first liquid storage unit includes a pressurizing mechanism that pressurizes the particle suspension. 5.   5. The droplet forming head according to claim 1, wherein the first liquid container is detachable from the second liquid container.   6. The droplet forming head according to claim 1, wherein the first liquid storage unit has a height adjusting mechanism capable of adjusting a height from the supply port to the discharge hole.   The liquid droplet forming head according to claim 1, wherein the first liquid storage unit has a position adjusting mechanism capable of adjusting a position in a horizontal direction.   8. The droplet forming head according to claim 1, wherein the second liquid storage unit includes a negative pressure mechanism that makes a negative pressure inside.   A droplet forming apparatus comprising the droplet forming head according to claim 1. A first liquid storage unit capable of storing a particle suspension in which settling particles are suspended, and having a supply port for supplying the particle suspension at the bottom;
Using a droplet forming head having the supply port of the first liquid storage unit therein, a discharge hole at the bottom, and a second liquid storage unit capable of storing a liquid,
Discharge for storing the particle suspension in the first liquid storage unit, storing the liquid in the second liquid storage unit, and discharging the particle suspension together with the liquid as droplets from the discharge hole A droplet forming method comprising a step.   The droplet forming method according to claim 10, wherein the viscosity of the liquid is higher than the viscosity of the particle suspension.

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