Liquid ejection device and liquid filling method

Abstract

To achieve stable liquid discharge.SOLUTION: A liquid discharge device according to one embodiment includes a membranous member having a nozzle hole for discharging a liquid, a support that supports the membranous member, and liquid discharge means having a liquid holder for holding one or more liquids including the liquid. The face of the membranous member on the liquid holder side has a water contact angle of less than 90 degrees.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present application relates to a liquid ejection device and a liquid filling method. [Background technology]

[0002] Conventionally, liquid ejection devices have been known, such as inkjet type and dispenser type liquid ejection devices. For example, Patent Document 1 discloses a configuration having a liquid storage chamber that can store liquid and is placed on a displacement member, and ejects liquid such as a cell suspension from a liquid ejection head. Summary of the Invention [Problem to be solved by the invention]

[0003] However, in a liquid ejection device configured as in Patent Document 1, bubbles are generated in the liquid containing chamber when liquid is supplied to the ejection head, and there is room for improvement in ejection stability.

[0004] An object of the present invention is to stabilize the ejection of liquid. [Means for solving the problem]

[0005] A liquid ejection device according to one aspect of the present invention includes a film-like member having nozzle holes for ejecting a liquid, a support portion for supporting the film-like member, and a liquid holding portion for holding one or more liquids including the liquid. and, a contact angle between the surface of the film-like member on the side of the liquid holding portion and water being at least less than 90 degrees; The ten-point average roughness of the surface of the film member on the liquid holding portion side is 10 μm or less. do. [Effects of the Invention]

[0006] According to the present invention, the ejection of liquid can be stabilized. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram illustrating an example of the overall configuration of a liquid ejection device according to an embodiment. [Figure 2] 2A and 2B are diagrams showing an example of the configuration of a supply unit according to an embodiment, in which FIG. 2A shows liquid absorption by the supply unit, and FIG. 2B shows liquid delivery by the supply unit. [Figure 3] 3A and 3B are diagrams illustrating an example of the configuration of a liquid ejection unit according to an embodiment. [Figure 4] 5A and 5B are diagrams illustrating the positional relationship between a liquid discharge unit and a tube according to the embodiment. [Figure 5] 3 is a block diagram showing an example of the functional configuration of a control unit according to the first embodiment. FIG. [Figure 6] 6A and 6B are diagrams showing how a supply unit supplies liquid, with FIG. 6A showing liquid absorption and FIG. 6B showing liquid delivery. [Figure 7] 7A and 7B are diagrams showing a supplying process by a supplying unit, in which FIG. 7A is a diagram of the liquid ejecting unit as seen from above, and FIGS. 7B and 7C are cross-sectional views taken along the line AA in FIG. 7A. [Figure 8] FIG. 10 is a diagram showing an example in which the first liquid is supplied at a slower speed than the second liquid. [Figure 9] FIG. 10 is a diagram showing an example in which the first liquid is supplied intermittently. [Figure 10] FIG. 10 is a diagram showing a state in which the second liquid is stirred. [Figure 11] 5 is a flowchart illustrating an example of the operation of the liquid ejection device according to the embodiment. [Figure 12] 12A and 12B are diagrams showing a state in which air bubbles remain inside the liquid discharge part, in which FIG. 12A is a diagram of the liquid discharge part as seen from above, and FIG. 12B is a cross-sectional view taken along line AA in FIG. 12A. [Figure 13] FIG. 10 is a diagram showing the relationship between the height of the liquid and the contact angle. [Figure 14] FIG. 10 is a diagram showing an example of separation of a first liquid. [Figure 15] FIG. 10 is a block diagram showing an example of the functional configuration of a control unit according to a second embodiment. [Figure 16] FIG. 10 is a diagram showing how the first liquid is discharged. [Figure 17] 10 is a flowchart showing an example of the operation of the liquid ejection device according to the second embodiment. [Figure 18]10A to 10C are diagrams illustrating the operation of the liquid ejection device according to the second embodiment. [Figure 19] FIG. 10 is a diagram showing a liquid discharge part in which the contact angle between the upper surface of the film-like member and water is 90 degrees or more. [Figure 20] FIG. 10 is a diagram showing a liquid discharge section in which the contact angle between the upper surface of the film-like member and water is less than 90 degrees. [Figure 21] 10A and 10B are diagrams illustrating an example of a hydrophilic film formed on the upper surface of a film-like member. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, a description will be given of an embodiment of the invention with reference to the drawings. In this embodiment, as an example of a liquid ejection device, an example will be described in which a liquid ejection device 100 that ejects a cell suspension onto a well plate 400 by an inkjet method is applied. In each drawing, identical components are designated by the same reference numerals, and duplicated explanations will be omitted as appropriate. A cell suspension is an example of a liquid, and hereinafter the cell suspension will be simply referred to as a liquid.

[0009] [First embodiment] <Example of overall configuration of liquid ejection device 100> First, the overall configuration of a liquid ejection device 100 will be described with reference to Fig. 1. Fig. 1 is a diagram illustrating an example of the overall configuration of a liquid ejection device 100 that uses an inkjet method.

[0010] As shown in FIG. 1, the liquid ejection device 100 includes a liquid ejection unit (also called an ejection head or a print head) 1, a supply unit 2, an ammeter 3, a control unit 4, and a storage unit 8.

[0011] In the embodiment, for convenience, the direction in which the liquid is ejected is defined as the Z-axis direction, and the plane perpendicular to the Z-axis direction is defined as the XY plane. In addition, in the Z-axis direction, the liquid ejection direction is defined as the downward direction, and the opposite direction is defined as the upward direction. Furthermore, for each component, the upper XY plane is defined as the top surface, and the lower XY plane is defined as the bottom surface. If the component is cylindrical with an internal cavity, the virtual XY planes of the component are defined as the top and bottom surfaces.

[0012] The liquid ejection device 100 supplies the liquid stored in the storage section 8 to the liquid ejection section 1 by the supply section 2, and ejects the liquid from the liquid ejection section 1, thereby forming droplets or tissue bodies of a cell suspension in wells 401, which are multiple well-shaped holes formed in a well plate 400.

[0013] The reservoir 8 is provided outside the liquid discharger 1 and stores the liquid 200 to be supplied to the liquid discharger 1. The reservoir 8 includes a first reservoir 81 and a second reservoir 82. The first reservoir 81 stores the first liquid. When two types of liquid are used, the second reservoir 82 stores the second liquid, which is a different type from the first liquid.

[0014] The supply unit 2 supplies the liquid stored in the storage unit 8 to the liquid discharge unit 1. The supply unit 2 includes a pump 21, a tube 22, and an actuator 23. The supply unit 2 drives the actuator 23 to change the positions of the pump 21 and the tube 22 and move them back and forth between the positions where the first storage unit 81 and the second storage unit 82 are respectively located and the position where the liquid discharge unit 1 is located.

[0015] Pump 21 and tube 22 absorb the first liquid at the position where first reservoir 81 is located, and then are moved by actuator 23 to the position where liquid discharger 1 is located, and after stopping, deliver the first liquid to liquid discharger 1. Note that "absorb" refers to sucking in liquid, and "deliver" refers to sending out liquid.

[0016] Furthermore, pump 21 and tube 22 absorb the second liquid at the position where second reservoir 82 is located, and then are moved by actuator 23 to the position where liquid discharger 1 is located, and after stopping, send the second liquid to liquid discharger 1. This allows supply unit 2 to supply each of the first liquid and the second liquid to liquid discharger 1.

[0017] The liquid discharger 1 discharges liquid supplied by the supply unit 2. The lower end of the liquid discharger 1 is inserted into the well 401. The liquid discharger 1 also has a MEMS (Micro Electro Mechanical System) chip 13 mounted on the lower end. When the drive waveform generator 7 applies a drive waveform (drive voltage) to the MEMS chip 13 via wiring 71 and 72, the liquid held in the liquid discharger 1 is discharged into the well 401 as droplets D.

[0018] The ammeter 3 is a detector that detects the current generated in the piezoelectric element 133 included in the MEMS chip 13 in response to the ejection of liquid by the MEMS chip 13 .

[0019] The control unit 4 is a control device that controls the overall operation of the liquid ejection device 100. The control unit 4 also has a function of causing the supply unit 2 to send or absorb liquid in accordance with the back electromotive force of the piezoelectric element 133 based on the current detected by the ammeter 3, and controlling the amount of liquid held in the liquid ejection unit 1.

[0020] <Supply section 2> Next, the configuration of the supply unit 2 will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of the configuration of the supply unit 2, with Fig. 2(a) showing liquid absorption by the supply unit 2 and Fig. 2(b) showing liquid delivery by the supply unit 2.

[0021] 2, the supply unit 2 includes a pump 21 and a tube 22. The pump 21 is a device that absorbs and delivers liquid. Any pump may be used as the pump 21 as long as it is capable of both absorbing and delivering liquid.

[0022] The tube 22 is a tubular member that forms a path through which the liquid that is sucked or pumped by the pump 21 passes. There are no particular restrictions on the material of the tube 22, but a flexible tube containing a resin material is preferred from the viewpoint of allowing the path to be selected arbitrarily.

[0023] It is preferable that the tube 22 is detachable from the pump 21. The tube 22 may be a disposable member such as a disposable tip, or may be a member that can be washed and reused multiple times. The supply unit 2 may further include a supply needle below the tube 22.

[0024] As shown in Figure 2(a), the supply unit 2 uses the actuator 23 (see Figure 1) to move the pump 21 and the tube 22 to the position where the storage unit 8 is located, and drives the pump 21 with the tip of the tube 22 inserted inside the storage unit 8, thereby absorbing the liquid 200 stored in the storage unit 8.

[0025] As shown in FIG. 2(b), the supply unit 2 uses the actuator 23 to move the pump 21 and the tube 22 to the position where the liquid discharge unit 1 is located, and drives the pump 21 with the tip of the tube 22 inserted inside the liquid discharge unit 1, thereby sending liquid into the inside of the liquid discharge unit 1.

[0026] The actuator 23 may be any device that can move the pump 21 and the tube 22 together, and is preferably, for example, a crane that lifts and transports the pump 21 and the tube 22 together. However, the configuration is not limited to one in which the pump 21 and the tube 22 are movable, and at least one of the pump 21 and the tube 22, the storage unit 8, and the liquid discharge unit 1 may be moved by an actuator or the like.

[0027] <Liquid discharge part 1> Next, the configuration of the liquid discharger 1 will be described with reference to Fig. 3. Fig. 3 is a diagram showing an example of the configuration of the liquid discharger 1, and is an enlarged view of the vicinity of the portion P indicated by the dashed line in Fig. 1.

[0028] 3, the liquid discharger 1 includes a liquid chamber member 11, an elastic member 12, and a MEMS chip 13. The MEMS chip 13 includes a holder 131, a film member 132, and a piezoelectric element 133. The elastic member 12 is, for example, an adhesive or double-sided tape, and the liquid chamber member 11 and the MEMS chip 13 are bonded together by the elastic member 12.

[0029] The liquid discharger 1 can hold liquid in a liquid holding portion 14 formed by the liquid chamber member 11, the elastic member 12, and the holding portion 131.

[0030] The liquid discharger 1 has an atmosphere-opening part 11A. The tip of a tube 22 included in the supply part 2 passes through the atmosphere-opening part 11A and is inserted into the liquid discharger 1. The outer and inner shapes of the liquid discharger 1 are, for example, a cylinder or a prism.

[0031] The MEMS chip 13 is a device fabricated by microfabricating a silicon substrate using a semiconductor process that uses photolithography. The MEMS chip 13 includes a holding portion 131, a film-like member 132, and a piezoelectric element 133, which are integrally formed on the substrate.

[0032] However, the substrate is not limited to silicon, and other materials such as glass can also be used. Furthermore, the manufacturing method of the piezoelectric element 133 is not limited to the semiconductor process, and a process other than the semiconductor process, such as a process of patterning a piezoelectric precursor liquid by an inkjet method, can also be used.

[0033] In the MEMS chip 13, the holding portion 131 can be made of metal, silicon, ceramic, or the like.

[0034] There are no particular limitations on the size of the liquid discharge unit 1 and the amount of liquid 200 that can be accommodated in the liquid discharge unit 1, and these can be selected appropriately depending on the purpose. The amount of liquid 200 can be, for example, 1 μL to 1 mL, and when the liquid 200 is a cell suspension or the like in which cells are dispersed, it can also be 1 μL to 50 μL.

[0035] However, the amount of liquid 200 is a factor that contributes to the vibration characteristics of film member 132, and is controlled and changed by control unit 4.

[0036] The film-like member 132 is fixed to the lower end of the holding part 131. A nozzle hole 132a, which is a through-hole, is formed approximately in the center of the film-like member 132. The liquid 200 held in the liquid discharge part 1 is discharged as droplets from the nozzle hole 132a due to vibration of the film-like member 132. The planar shape of the film-like member 132 can be, for example, circular, but may also be elliptical or rectangular. It is preferable that the shape corresponds to the shape of the bottom of the holding part 131.

[0037] Although there are no particular limitations on the material of the film-like member 132, if it is too soft, the film-like member 132 will vibrate easily, making it difficult to immediately stop the vibration when not discharging, so it is preferable to use a material with a certain degree of hardness. Examples of materials that can be used for the film-like member 132 include metal materials, ceramic materials, and polymeric materials with a certain degree of hardness.

[0038] In particular, when cells are used as the sedimentary particles (not shown), it is preferable that the material of the membrane member 132 be a material that has low adhesiveness to cells and proteins. Cell adhesiveness is generally said to depend on the contact angle of the material with water, and when the material is highly hydrophilic or highly hydrophobic, cell adhesiveness is low. Various metal materials and ceramics (metal oxides) can be used as highly hydrophilic materials, and fluororesins and the like can be used as highly hydrophobic materials.

[0039] Other examples of such materials include stainless steel, nickel, aluminum, silicon dioxide, alumina, zirconia, etc. Alternatively, cell adhesion can be reduced by coating the surface of the material. For example, the surface can be coated with the aforementioned metal or metal oxide materials, or with a synthetic phospholipid polymer that mimics cell membranes (e.g., Lipidure, manufactured by NOF Corporation).

[0040] When there is no liquid 200, the film member 132 vibrates based on a resonance period determined by its dimensions and material. When there is liquid 200, the film member 132 has the characteristic that the resonance period varies depending on the amount of liquid 200 held in the liquid discharger 1. Generally, the more the liquid volume E of the liquid 200 increases, the greater the inertial force, and therefore the film member 132 tends to have a longer resonance period (a lower resonance frequency).

[0041] The nozzle hole 132a is preferably formed as a substantially circular through-hole approximately in the center of the membrane member 132. In this case, there are no particular limitations on the diameter of the nozzle hole 132a, but it is preferably at least twice the size of the sedimentary particles 250 in order to prevent the sedimentary particles 250 from clogging the nozzle hole 132a and to stably discharge the droplets D. Specifically, since the size of animal cells, particularly human cells, is generally about 5 μm to 50 μm, it is preferable to set the diameter of the nozzle hole 132a to 10 μm to 100 μm or more to match the size of the cells to be used.

[0042] On the other hand, if the droplets become too large, it becomes difficult to achieve the goal of forming minute droplets, so the diameter of the nozzle holes 132a is preferably 200 μm or less. Therefore, in the liquid ejection device 100, the diameter of the nozzle holes 132a is typically in the range of 10 μm to 200 μm.

[0043] The drive waveform generating source 7 is a signal generator that outputs a drive waveform as a drive signal to the piezoelectric element 133. By outputting the drive waveform to the piezoelectric element 133, the drive waveform generating source 7 can deform the film member 132 and eject the liquid 200 held in the liquid ejection unit 1 as droplets D. In addition, by deforming the film member 132 with a drive waveform set at a predetermined cycle, it is possible to cause the film member 132 to resonate and vibrate, causing ejection.

[0044] The piezoelectric element 133 is an example of a vibrating section that vibrates the film member 132, and is formed on the underside of the film member 132. The shape of the piezoelectric element 133 can be designed to match the shape of the film member 132. For example, if the planar shape of the film member 132 is circular, it is preferable to form the piezoelectric element 133 having an annular (ring-shaped) planar shape around the nozzle hole 132a.

[0045] FIG. 4 is a diagram showing an example of the positional relationship between the liquid discharger 1 and the tube 22 in the supply unit 2 when the supply unit 2 supplies the liquid 200 to the liquid discharger 1.

[0046] When the supply unit 2 supplies the liquid 200 to the liquid discharge unit 1, it is preferable that H is short, where H is the distance from the lower surface 22a of the tube 22 to the upper surface 132b of the membrane member 132. If H is short when supplying the liquid 200, the kinetic energy of the liquid 200 decreases when the supplied liquid 200 reaches the membrane member 132 or the upper surface of the previously supplied liquid 200, and the generation of bubbles due to vibration of the liquid 200 or splashing of the liquid 200 can be suppressed.

[0047] Furthermore, it is preferable that the centers of the upper and lower surfaces of the liquid chamber member 11 and the holding portion 131 in the liquid discharger 1 are on the same axis a'. It is also preferable that the lower surface of the tube 22 is smaller than the upper surface of the inner wall of the holding portion 131.

[0048] Furthermore, it is preferable that the tube 22 is inserted parallel to the axis a' into the liquid discharger 1. This prevents the tube 22 from coming into contact with the inner wall of the liquid discharger 1 when the tube 22 is inserted, and suppresses the transmission of vibration to the liquid discharger 1 and the generation of bubbles due to impact.

[0049] <Control unit 4> The functional configuration of the control unit 4 in the liquid ejection device 100 will now be described with reference to Fig. 5. Fig. 5 is a block diagram showing an example of the functional configuration of the control unit 4.

[0050] 5, the control unit 4 includes a discharge control unit 41, a supply control unit 42, and a stirring control unit 43. Each of these functions can be realized by an electric circuit, and some of these functions can also be realized by software (CPU: Central Processing Unit). These functions may also be realized by multiple circuits or multiple pieces of software.

[0051] The discharge control unit 41 controls the application of a drive waveform to the MEMS chip 13 by the drive waveform generation source 7, thereby controlling the discharge of droplets by the MEMS chip 13. Furthermore, the supply control unit 42 controls the supply of liquid to the liquid discharge unit 1 by the supply unit 2. The agitation control unit 43 controls the agitation of the liquid supplied to the liquid discharge unit 1 by the supply unit 2.

[0052] <liquid> Next, we will explain the first liquid stored in first storage section 81 and the second liquid stored in second storage section 82. The liquid that is filled first is the first liquid, and the liquid that is filled later is the second liquid.

[0053] The first liquid is not particularly limited as long as the contact angle, which is an index of wettability, with respect to the upper surface of the MEMS chip 13 is at least less than 90°, but the surface tension of the first liquid is preferably 30 mN / m or less, and more preferably 20 mN / m or less, in a 25°C environment. A first liquid with low surface tension spreads easily, so the first liquid spreads widely to every corner of the liquid discharger 1. This allows the first liquid to spread widely without creating voids within the liquid discharger 1 when supplied to the liquid discharger 1, thereby suppressing the generation and retention of air bubbles.

[0054] When two types of liquids are used, it is preferable that the first liquid is insoluble in the second liquid (i.e., the first liquid and the second liquid are not compatible). This prevents the first liquid from dissolving in the second liquid, thereby suppressing changes in the concentration and properties of the second liquid. It is also preferable that the first liquid has a lower density than the second liquid. If the first liquid has a lower density than the second liquid and is insoluble in it, when the second liquid is supplied, the first liquid completely covers the top surface of the second liquid like a lid, preventing the second liquid from coming into contact with the atmosphere. This suppresses volatilization of the second liquid and suppresses changes in concentration due to drying of the second liquid.

[0055] Furthermore, it is preferable that the first liquid is non-cytotoxic. Non-cytotoxicity means that it does not impair the function of cells. In this case, even if a cell suspension is used as the second liquid, it will not adversely affect the cells contained in the second liquid. The first liquid preferably has a viscosity that allows it to be ink-jet ejected.

[0056] Examples of the first liquid that meets these conditions include silicone oil and liquid paraffin.

[0057] The second liquid is a liquid to be ejected, and is not particularly limited as long as it is a liquid that can be ejected by the liquid ejection device 100. It may be ink or a cell suspension. When the liquid ejection device 100 is an inkjet type, the second liquid preferably has a viscosity that allows it to be ejected by the inkjet type, but for liquid ejection devices other than the inkjet type, the second liquid is not limited to this.

[0058] Incidentally, the first liquid may be the liquid to be ejected as long as its contact angle with the upper surface of the MEMS chip 13 is at least less than 90°. In this case, it is preferable that the first liquid has a higher density than the second liquid. If the first liquid has a higher density than the second liquid and is insoluble, when the second liquid is supplied, the second liquid completely covers the upper surface of the first liquid like a lid, preventing the first liquid from coming into contact with the atmosphere. This suppresses volatilization of the first liquid and suppresses changes in concentration due to drying of the first liquid. It is preferable that the second liquid be non-cytotoxic, such as silicone oil or liquid paraffin.

[0059] <Supply process> 6A and 6B are diagrams showing how the supply unit 2 supplies the liquid 200, with FIG. 6A showing the liquid absorption and FIG. 6B showing the liquid delivery.

[0060] As shown in FIG. 6(a), the tip of tube 22 is inserted into storage portion 8 and liquid 200 is sucked. Thereafter, as shown in FIG. 6(b), the tip of tube 22 is inserted into liquid discharge portion 1 and liquid 200 is delivered. In this manner, liquid 200 can be supplied to liquid discharge portion 1. Both the first liquid and the second liquid can be supplied in the same way, but supply portion 2 absorbs the first liquid from first storage portion 81 and the second liquid from second storage portion 82.

[0061] However, when the tip of the tube 22 is inserted into the liquid discharger 1 and the liquid 200 is supplied, air may enter the liquid discharger 1 as the liquid 200 is supplied, and bubbles may be generated within the liquid discharger 1. Most of the bubbles are expelled from the liquid discharger 1, but some may adhere to the wall surfaces within the liquid discharger 1 and remain within the liquid discharger 1. Air bubbles are particularly likely to remain at corners 134 where surfaces intersect within the liquid discharger 1.

[0062] Figure 7 is a diagram illustrating a supplying process by the supplying unit 2. Figure 7(a) is a diagram of the liquid ejecting unit 1 viewed from above, and Figures 7(b) and 7(c) are cross-sectional views taken along line AA in Figure 7(a).

[0063] 7(b) is a diagram showing the step of supplying the first liquid. In the step of supplying the first liquid, the supply unit 2 supplies the first liquid 201 from the first storage unit 81 to the liquid discharge unit 1. The first liquid 201 is a liquid having a lower surface tension than the second liquid 202. The first liquid 201 has a low surface tension and is therefore easily wetted and spreads, so that it spreads widely throughout the entire interior of the liquid discharge unit 1, and the generation and retention of air bubbles are suppressed. In the first liquid supply step, when the first liquid 201 is sent to the liquid discharger 1, if the distance from the lower surface 22a of the tube 22 to the upper surface 132b of the membrane member 132 is H, it is preferable that H is short. This reduces the kinetic energy of the supplied first liquid 201 when it reaches the membrane member 132, making it possible to suppress the generation of bubbles due to vibration or scattering of the first liquid 201.

[0064] 7(c) is a diagram showing the step of supplying the second liquid. In the step of supplying the second liquid, the supply unit 2 supplies the second liquid 202 from the second reservoir 82 to the liquid discharger 1. Because the second liquid 202 is supplied to the liquid discharger 1 to which the first liquid 201 has been supplied, the liquid discharger 1 can hold the second liquid 202 in a state where air bubbles are suppressed compared to when only the second liquid 202 is supplied to the liquid discharger 1.

[0065] In the step of supplying the second liquid, when the second liquid 202 is sent to the liquid discharger 1, it is preferable that the lower surface 22a of the tube 22 contacts at least a part of the first liquid 201. For example, it is preferable that the lower surface 22a of the tube 22 contacts the upper surface of the first liquid 201 or is inserted into the first liquid 201. This reduces the kinetic energy of the second liquid 202 when it reaches the upper surface of the first liquid 201 that was previously supplied, making it possible to suppress the generation of bubbles due to vibration or scattering of the first liquid 201 or the second liquid 202.

[0066] Thus, in this embodiment, after the supply unit 2 supplies the first liquid 201 with a small contact angle to the upper surface of the MEMS chip 13 to the liquid ejection unit 1, the second liquid 202 is supplied to the liquid ejection unit 1. Therefore, since the first liquid 201 with a small contact angle to the upper surface of the MEMS chip 13 reaches the corners inside the liquid ejection unit 1 and the upper surface of the film member earlier than the second liquid 202, the generation and residue of bubbles in the liquid ejection unit 1 are suppressed.

[0067] <Details of the Second Supply Step> Next, the details of the second supply step will be described. By performing the second supply step after the first supply step, the generation and residue of bubbles can be suppressed, but it is more preferable to take the mode shown in FIG. 8 or FIG. 9 below. Here, let the supply rate of the first liquid 201 in the first step be V1, and the supply rate of the second liquid 202 in the second step be V2. V1 and V2 respectively indicate the supply rate when supplied over the supply time T1 for the specified supply amount Q1, and the supply rate when supplied over the supply time T2 for the specified supply amount Q2.

[0068] FIG. 8 is a diagram showing an example of supplying the first liquid 201 at a lower speed than the second liquid 202. <000^276> As shown in FIG. 8, it is preferable that the supply rate V1 of the first liquid 201 in the first supply step is lower than the supply rate V2 of the second liquid 202 in the second supply step (V1 < V2). By making V1 lower than V2, the generation of bubbles can be further suppressed when supplying the first liquid 201. When changing the supply amounts of Q1 and Q2, although the filling time changes accordingly, it is assumed that the supply rate remains V1 < V2.

[0070] FIG. 9 is a diagram showing an example of intermittently supplying the first liquid 201.

[0071] 9, it is preferable to divide the supply time T1 during which the liquid supply amount Q1 is supplied in the first supply step into T1A, T1B, and T1C. In other words, it is preferable to divide the supply amount Q1 of the first liquid 201 in the first supply step into multiple parts and supply them intermittently in small amounts. By supplying the first liquid 201 intermittently in this manner, it is possible to further suppress the generation of bubbles when the first liquid 201 is supplied.

[0072] <Stirring process> 10 is a diagram showing the agitation of the second liquid 202. In order to prevent a portion of the second liquid 202 from settling, it is preferable to have a step of agitating the second liquid 202 supplied to the liquid discharger 1.

[0073] The stirring is preferably performed by the supply unit sending and absorbing the second liquid 202.

[0074] The stirring may be performed after the second liquid 202 is supplied, or may be performed while the second liquid 202 is being supplied. When stirring is performed after the second liquid 202 is supplied, it is preferable to stir the second liquid 202 while keeping the tube 22 inserted into the liquid discharge part 1 inserted in the second liquid 202. This makes it possible to stir the second liquid 202 while suppressing the generation of new bubbles in the supplied first liquid 201 and second liquid 202.

[0075] Furthermore, the tube 22 may be moved up and down while stirring the second liquid 202. This allows the second liquid 202 to be stirred evenly.

[0076] <Liquid ejection method using liquid ejection device 100> Next, a liquid ejection method using the liquid ejection device 100 will be described with reference to Fig. 11. Fig. 11 is a flowchart illustrating an example of the operation of the liquid ejection device 100.

[0077] First, in step S91, the supply control unit 42 drives the supply unit 2 to supply the first liquid 201 to the liquid discharge unit 1 as a first supply step.

[0078] Subsequently, in step S92, the supply control unit 42 drives the supply unit 2 to supply the second liquid 202 to the liquid discharge unit 1 as a second supply step.

[0079] Thereafter, in step S93, the stirring control unit 43 determines whether or not stirring of the second liquid 202 is necessary.

[0080] If it is determined in step S93 that the second liquid 202 needs to be stirred (step S93, No), the stirring control unit 43 causes the supply unit 2 to stir the second liquid 202 in step S93-1.

[0081] If it is determined in step S93 that the second liquid 202 does not need to be stirred (step S93, Yes), it is determined in step S94 whether or not the volume of the second liquid 202 is sufficient.

[0082] If it is determined in step S94 that the volume of the second liquid 202 is not sufficient (step S94, No), the process returns to step S92, and the operation of step S92 is performed again.

[0083] If it is determined in step S94 that the volume of the second liquid 202 is sufficient (step S94, Yes), then in step S95 the discharge control section discharges the second liquid 202 as a discharge step.

[0084] Subsequently, in step S96, the supply control unit 42 determines whether or not additional ejection of the second liquid 202 is necessary.

[0085] In step S96, if it is determined that additional ejection of the second liquid 202 is necessary (step S96, Yes), the process returns to step S95, and the operation of step S95 is performed again.

[0086] If it is determined in step S96 that additional ejection of the second liquid 202 is not necessary (step S96, No), the liquid ejection device 100 ends the operation.

[0087] <Action and effect> FIG. 12 shows a state in which an air bubble remains in the liquid discharger 1, where FIG. 12(a) is a view of the liquid discharger 1 as seen from above, and FIG. 12(b) is a cross-sectional view taken along line AA of FIG. 12(a). In FIG. 12, an air bubble 210 remains in a corner 134 of the liquid discharger 1. As shown in FIG. 12(b), if the surface tension of the liquid prevents the liquid from reaching the corner 134 where the inner wall surface of the film-like member 132 and the inner wall surface of the holding portion 131 intersect, a space is created in the corner 134. Air in the space adheres to the wall surface as air bubbles, making it easier for air bubbles to remain in the corner 134. Air bubbles may also adhere to and remain on the upper surface of the film-like member 132, etc.

[0088] If air bubbles remain inside the liquid discharger 1, the pressure applied to the liquid when discharging the liquid will be absorbed by the air bubbles, making the discharge unstable. If the liquid is discharged while it contains air bubbles in this way, the discharge by the liquid discharger 1 may become unstable.

[0089] In this embodiment, the first liquid 201 is supplied before the second liquid 202, and the first liquid 201 has a contact angle of at least less than 90° with respect to the top surface of the MEMS chip 13. The first liquid 201 has a small contact angle and spreads easily, so it spreads widely throughout the entire interior of the liquid discharger 1 and reaches the corners 134. This makes it possible to suppress the generation and retention of air bubbles at the corners 134. By supplying the second liquid 202 after the first liquid 201 has reached the corners 134, the liquid discharger 1 can hold the second liquid 202 in a state where air bubbles are suppressed.

[0090] Fig. 13 is a diagram showing the relationship between the height of the liquid and the contact angle. Specifically, Fig. 13 shows how the liquid 200, when supplied to the liquid discharger 1, spreads in the S direction over the upper side of the film-like member 132. H1 indicates the height at which the liquid spreads when a small amount of liquid is supplied at one time, and H2 indicates the height at which the liquid spreads when a larger amount of liquid is supplied at one time than H1. Furthermore, θ1 and θ2 indicate the contact angles that the liquid surface makes with the film-like member 132 at H1 and H2, respectively. However, the liquid supply speed is the same at H1 and H2.

[0091] 13, the contact angle of the liquid 200 with the film-like member 132 is smaller for H1 than for H2. That is, when a smaller amount of liquid 200 is supplied at one time, the height of the liquid 200 is lower, and the contact angle of the liquid surface with the film-like member 132 is smaller. As a result, the liquid 200 spreads widely and reaches the corners 134, thereby suppressing the generation of bubbles at the corners 134. Furthermore, the generation of bubbles on the upper surface of the film-like member, etc. is also suppressed.

[0092] Similarly, when the supply amount of the liquid 200 is the same, H becomes smaller when the supply speed is slower, and therefore the generation of bubbles at the corners 134, the upper surface of the film-like member, and the like is suppressed.

[0093] [Second embodiment] Next, a liquid ejection device 100a according to a second embodiment will be described. Note that the same components as those described in the first embodiment will be assigned the same part numbers, and duplicated descriptions will be omitted as appropriate. This also applies to the following embodiments.

[0094] The second embodiment differs from the first embodiment in that it includes a discharge step after the second supply step.

[0095] If the first liquid 201 has a lower density than the second liquid 202, when the second liquid 202 is supplied in the second supply step, the first liquid 201 will rise to the top surface of the second liquid 202 and cover the first liquid 201 like a lid, as described above. At this time, not all of the first liquid 201 will necessarily rise to the top, and as shown in Fig. 14, the first liquid 201 may separate into two, one of which may remain at the bottom of the liquid discharger 1. Here, the bottom of the liquid discharger 1 refers to the vicinity of the film-like member 132.

[0096] In FIG. 14, when the second liquid 202 is supplied, a portion 201A of the first liquid 201 floats to the upper side of the second liquid 202, and the other portion 201B remains at the bottom.

[0097] The remaining part 201B remaining at the bottom of the liquid discharger 1 is preferably discharged to the outside of the liquid discharger 1 before the second liquid 202 is discharged onto the well plate 400.

[0098] <Control unit 4> 15 is a block diagram showing an example of the functional configuration of the control unit 4a included in the liquid ejection device 100a. As shown in FIG.

[0099] The discharge control unit 44 controls the discharge of the first liquid 201. The discharge control unit 44 may discharge the first liquid 201 by the MEMS chip 13 by controlling the application of a drive waveform to the MEMS chip 13 by the drive waveform generation source 7, or may discharge the first liquid 201 by suction using the supply unit 2.

[0100] <Discharge process> 16 is a diagram showing how the first liquid 201 is discharged. As shown in FIG. 16, the first liquid 201 may be discharged into a dedicated container 300, or may be sucked by the supply unit 2.

[0101] <Liquid ejection method using liquid ejection device 100a> Next, a liquid ejection method using the liquid ejection device 100a will be described with reference to Fig. 17. Fig. 17 is a flowchart illustrating an example of the operation of the liquid ejection device 100a.

[0102] First, in step S151, as a first supply step, the supply control unit 42 drives the supply unit 2 to supply the first liquid 201 to the liquid discharge unit 1. At this time, as described in FIG. 8 or FIG. 9, the supply speed of the first liquid 201 may be slowed down or divided and supplied.

[0103] Subsequently, in step S152, the supply control unit 42 drives the supply unit 2 to supply the second liquid 202 to the liquid discharge unit 1 as a second supply step.

[0104] Thereafter, in step S153, the supply control unit 42 determines whether the first liquid is present at the bottom of the liquid discharge unit 1 or not.

[0105] In step S153, if it is determined that the first liquid 201 is present at the bottom of the liquid discharger 1 (step S153, Yes), in step S153-1, the discharge controller discharges the first liquid 201 at the bottom.

[0106] In step S153, if it is determined that the first liquid 201 is not present at the bottom of the liquid discharger 1 (step S153, No), in step S154, the supply control unit 42 determines whether or not the second liquid 202 does not need to be stirred.

[0107] If it is determined in step S154 that the second liquid 202 needs to be stirred (step S154, No), the supply control unit 42 stirs the second liquid 202 in step S154-1.

[0108] If it is determined in step S154 that the second liquid 202 does not need to be stirred (step S154, Yes), it is determined in step S155 whether or not the volume of the second liquid 202 is sufficient.

[0109] If it is determined in step S155 that the volume of the second liquid 202 is not sufficient (step S155, No), the process returns to step S152, and the operation of step S152 is performed again.

[0110] If it is determined in step S155 that the volume of the second liquid 202 is sufficient (step S155, Yes), then in step S156 the discharge control section discharges the second liquid 202 as a discharge step.

[0111] Subsequently, in step S157, the supply control unit 42 determines whether or not additional ejection of the second liquid 202 is necessary.

[0112] In step S157, if it is determined that additional ejection of the second liquid 202 is necessary (step S157, Yes), the process returns to step S154, and the operation of step S154 is performed again.

[0113] If it is determined in step S157 that additional ejection of the second liquid is not necessary (step S157, No), the liquid ejection device 100a ends its operation.

[0114] <Operation and Effects of Liquid Discharger 100a> 18, when the second liquid 202 is discharged onto a well plate 400 or the like, it is possible to prevent the first liquid 201 from being contained in the droplets. Since the first liquid 201 is not contained in the droplets when the second liquid 202 is discharged onto a well plate 400 or the like, it is possible to reliably discharge only the second liquid 202.

[0115] [Third embodiment] Next, a liquid ejection device 100b according to a third embodiment will be described.

[0116] A liquid ejection device 100b according to this embodiment includes at least a liquid ejection unit 1b. The liquid ejection device 100b can be configured, for example, as the liquid ejection device 100 shown in FIG.

[0117] 3 can be applied to the configuration of the liquid discharger 1b, but differs from the liquid discharger 1 in that the contact angle with water of an upper surface 132b (an example of a first surface), which is the surface of the film-like member 132 of the liquid discharger 1b on the liquid holding portion 14 side, is less than 90 degrees. In this embodiment, the first liquid 201 and the second liquid 202 each contain water.

[0118] In this embodiment, as an example, the liquid ejection device 100b has a supply unit 2b in addition to the liquid ejection unit 1b. The configuration of the supply unit 2b can be the same as that of the supply unit 2 shown in FIG.

[0119] 19 and 20 are diagrams illustrating the operation of the liquid ejection device 100b. Fig. 19 is a diagram illustrating a liquid ejection unit 1X to which this embodiment is not applied, in which the contact angle between the upper surface 132b of the film-like member 132 and water is 90 degrees or more. Fig. 20 is a diagram illustrating a liquid ejection unit 1b according to this embodiment, in which the contact angle between the upper surface 132b of the film-like member 132 and water is less than 90 degrees. In Figs. 19 and 20, the only difference is the contact angle between the upper surface 132b and water, and therefore, for convenience, the same reference numerals are used for components that are the same or of the same quality.

[0120] Fig. 19 illustrates the process by which water 203 is supplied into the liquid holding unit 14 of the liquid ejection unit 1X from the top to the bottom of the figure. Fig. 19 also shows a cross-sectional view of the liquid ejection unit 1X, with a top view of the film-like member 132 also shown on the right side of the cross-sectional view. Similarly, Fig. 20 illustrates the process by which water 203 is supplied into the liquid holding unit 14 of the liquid ejection unit 1b from the top to the bottom of the figure. Fig. 20 also shows a cross-sectional view of the liquid ejection unit 1b, with a top view of the film-like member 132 also shown on the right side of the cross-sectional view.

[0121] 19, since the upper surface 132b of the film member 132 has low wettability, the water supplied to the liquid holding unit 14 spreads over the upper surface 132b while maintaining a high contact angle. As a result, as the supply of water 203 progresses, air bubbles 210 enter and remain in the corners 134 of the liquid holding unit 14.

[0122] 20, in this embodiment, the upper surface 132b of the film-like member 132 is configured to have good wettability (contact angle less than 90°) with respect to water 203. This allows the water supplied to the liquid holding unit 14 to wet and spread more than the liquid discharge unit 1X, and prevents air bubbles 210 from entering the corners 134 of the liquid holding unit 14 as the supply of water 203 progresses.

[0123] The contact angle can be measured by the sessile drop method in JIS R 3257 "Test method for wettability of glass substrate surfaces." This sessile drop method can be applied even to objects that do not contain glass materials.

[0124] For example, by forming a hydrophilic film (hydrophilic film) on the upper surface 132b, the wettability of the upper surface 132b can be increased so that the contact angle between the upper surface 132b and water is less than 90 degrees. The hydrophilic film can be formed by coating the upper surface 132b with a hydrophilic material or by surface-modifying the upper surface 132b with plasma. An example of a hydrophilic material is an oxide. In other words, the hydrophilic film can be composed of, for example, an oxide. Figure 21 illustrates a hydrophilic film 132c formed on the upper surface 132b of the film-like member 132.

[0125] In this embodiment, the first liquid 201 and the second liquid 202 each contain water, so when the first liquid 201 or the second liquid 202 is supplied to the liquid holding portion 14, the same effect as when water is supplied can be obtained.

[0126] When a cell suspension is used as the second liquid 202, it is preferable to periodically stir the first liquid 201 or the second liquid 202 held in the liquid holder 14, because cell sedimentation can cause the concentration to become inhomogeneous or the nozzle holes 132a to become clogged. In this case, if the surface roughness of the upper surface 132b of the membrane member 132 is high, the settled cells will get trapped in the uneven surface roughness, reducing the stirrability. If a strong flow is generated to sufficiently stir the cells, the cells will be damaged. For this reason, it is preferable that the upper surface 132b has high wettability and a smooth surface. The surface roughness of the upper surface 132b is preferably smaller than the size of the cells. For example, the surface roughness of the upper surface 132b is preferably 10 μm or less in terms of the ten-point average roughness Rz. Surface roughness can be measured using techniques known in the art.

[0127] The upper surface 132b can be smoothed by applying a coating, etc. By smoothing the surface of the upper surface 132b, the liquid discharger 100b can homogenize the concentration of the cell suspension by stirring while preventing damage to the cells, and can prevent clogging of the nozzle hole 132a.

[0128] <Modification of the third embodiment> As explained in the first and second embodiments, there are cases where the liquid discharger 1b supplies not only the second liquid 202 but also the first liquid 201 to the liquid holder 14. When a cell suspension is used as the second liquid 202, usable solvents are limited in consideration of biocompatibility and subsequent culturing.

[0129] Furthermore, due to performance and processing constraints of the liquid discharge unit 1b, there may be limitations on the surface treatment of the upper surface 132b of the film-like member 132. Due to these limitations, it may be difficult to obtain a desired contact angle depending on the combination of the upper surface 132b and the first liquid 201.

[0130] Therefore, in this modified example, a first liquid 201, which has good wettability with respect to the liquid ejection portion 1b and is less likely to entrain air bubbles 210, is supplied to the liquid holding portion 14, and then a second liquid 202 is supplied to the liquid holding portion 14.

[0131] It is preferable that the first liquid 201 is a liquid that does not affect the second liquid 202 itself or the ejection of the second liquid 202. For example, if the second liquid 202 is a cell suspension, the first liquid 201 cannot be used because it is toxic to the cells contained in the cell suspension.

[0132] Furthermore, if the first liquid 201 and the second liquid 202 mix together, the concentration of the second liquid 202 will decrease and cell culture will be affected. Furthermore, in order to prevent the first liquid 201 from remaining in the vicinity of the nozzle hole 132a, it is preferable that the first liquid 201 has a low specific gravity and a low surface tension to prevent the entrainment of air bubbles 210.

[0133] In order to satisfy the above conditions, the first liquid 201 is preferably silicone oil, liquid paraffin, or the like. Furthermore, the first liquid 201 preferably covers the entire second liquid 202, as if covering the side of the second liquid 202 that is open to the atmosphere, so that the second liquid 202 does not come into contact with the atmosphere. This has the effect of preventing the second liquid 202 from drying out or volatilizing. As a result, it is possible to prevent changes in the concentration of the second liquid 202.

[0134] Furthermore, it is preferable that the supply unit 2 supplies the first liquid 201 to the liquid holding unit 14, and then supplies the second liquid 202. This allows the liquid ejection device 100b to spread the first liquid 201 throughout the liquid holding unit 14, and more preferably prevents the generation of bubbles 210 at corners 134 and the like. If the supply unit 2 supplies the first liquid 201 to the liquid holding unit 14 in multiple batches, the generation of bubbles 210 can be more preferably prevented.

[0135] The surface tension of the first liquid 201 is preferably 25 dyne / cm or less. This allows the first liquid 201 to spread and wet when supplied to the liquid holding portion 14, thereby preventing the generation of bubbles 210 at the corners 134. For example, in an experiment in which a liquid containing 70% ethanol and having a surface tension of 26 dyne / cm was supplied to the liquid holding portion 14, bubbles 210 were generated in the liquid holding portion 14. Therefore, the surface tension of the first liquid 201 is preferably 25 dyne / cm or less, which is lower than 26 dyne / cm.

[0136] The film-like member 132 is disposed vertically below the liquid holding portion 14, and it is preferable that the first liquid 201 and the second liquid 202 are insoluble, that the first liquid 201 is non-volatile and has a specific gravity lighter than that of the second liquid 202, and that the first liquid 201 is supplied so as to cover the entire upper surface of the second liquid 202. This allows the liquid ejection device 100b to place the first liquid 201 on the upper surface side of the second liquid 202 supplied to the liquid holding portion 14, thereby preventing the second liquid 202 from coming into contact with the air and drying out.

[0137] After the first liquid 201 and the second liquid 202 are supplied to the liquid holding portion 14, the liquid ejection portion 1b preferably ejects the first liquid 201 held in the liquid holding portion 14, thereby removing the first liquid 201 from inside the liquid holding portion 14. In this way, when the liquid ejection device 100b supplies the second liquid 202 to the liquid holding portion 14, it can remove the first liquid 201 that has accumulated on the film-like member 132 side inside the liquid holding portion 14, and can eject only the second liquid 202 that is originally intended to be ejected from the nozzle holes 132a of the film-like member 132.

[0138] When the first liquid is the liquid to be ejected, it is preferable that the film-like member 132 is disposed vertically below the liquid holding portion 14, the first liquid 201 and the second liquid 202 are insoluble, the second liquid 202 is non-volatile, has a specific gravity lighter than the first liquid 201, and is supplied so as to cover the entire upper surface of the first liquid 201. In this way, the liquid ejection device 100b can supply the second liquid 202 after the first liquid 201, and prevent the first liquid 201 from drying out.

[0139] It is preferable that the supply speed of the first liquid 201 to the liquid holding portion 14 is slower than the supply speed of the second liquid 202. This allows the liquid ejection device 100b to improve the effectiveness of preventing the generation of bubbles 210.

[0140] It is preferable that the second liquid 202 contains cells, and the first liquid 201 is a liquid that is not toxic to the cells contained in the second liquid 202. This allows the liquid ejection device 100b to use a cell suspension as the second liquid 202.

[0141] The first liquid 201 is preferably either silicone oil or liquid paraffin, which satisfies the conditions that the first liquid 201 has a low specific gravity, a low surface tension, and is not toxic to cells.

[0142] Although the embodiments have been described above, the present invention is not limited to the specifically disclosed above embodiments, and various modifications and changes are possible without departing from the scope of the claims.

[0143] Furthermore, all ordinal numbers, quantitative numbers, and other figures used in the description of the embodiments are merely examples for specifically explaining the technology of the present invention, and the present invention is not limited to the exemplified figures. Furthermore, the connection relationships between the components are merely examples for specifically explaining the technology of the present invention, and the connection relationships for realizing the functions of the present invention are not limited to these.

[0144] The embodiments also include a liquid filling method. For example, the liquid filling method is a method for filling a liquid discharge means including a film-like member having nozzle holes for discharging the liquid, a support member for supporting the film-like member, and a liquid holding member for holding one or more liquids including the liquid, wherein the liquid initially filled into the liquid discharge means is a first liquid, and the contact angle between the first liquid and the surface of the film-like member facing the liquid holding member is at least less than 90 degrees. This liquid filling method can also achieve the same effects as the liquid discharge device described above. [Explanation of symbols]

[0145] 1 Liquid discharge part 11 Liquid chamber member 11A Atmospheric release section 12 Elastic member 13 MEMS chip 14 Liquid holding part 131 Holding part 132 Membrane-like member 132a Nozzle hole 132b Top surface 133 Piezoelectric element 134 Corner 2 Supply section 21 Pump 22 tubes 22a Bottom side 23 Actuator 3 Ammeter 4. Control section 41 Discharge control section 42 Supply control section 43 Mixing control unit 44 Emission control section 7. Drive waveform source 71,72 Wiring 8. Storage section 81 First storage section 82 Second storage section 200 liquid 201 First Liquid 202 Second Liquid 300 containers 400-well plate 401 wells V1,V2 supply speed T1, T2 supply time Q1,Q2 Supply amount θ1,θ2 Contact angle H1, H2 height [Prior art documents] [Patent documents]

[0146] [Patent Document 1] Patent Publication No. 2020-092692

Claims

1. a film-like member having a nozzle hole for discharging a liquid; a support portion that supports the membrane member; a liquid holding portion that holds one or more liquids including the liquid, the contact angle between the surface of the film member on the liquid holding portion side and water is at least less than 90 degrees, A liquid ejection device, characterized in that the ten-point mean roughness of the surface of the film-like member on the side of the liquid holding portion is 10 μm or less.

2. a supply unit that supplies a first liquid to the liquid holding unit, The supply unit is capable of supplying the first liquid in a plurality of batches. The liquid ejection device according to claim 1 .

3. the supply unit agitates the first liquid by supplying and absorbing the first liquid to and from the liquid holding unit; The liquid ejection device according to claim 2 .

4. a film-like member having a nozzle hole for discharging a liquid; a support portion that supports the membrane member; a liquid holding portion that holds one or more liquids including the liquid, the liquid that is initially filled into the liquid discharge means is designated as a first liquid; a contact angle between the surface of the film member on the liquid holding portion side and the first liquid is at least less than 90 degrees; A liquid filling method, characterized in that after filling with the first liquid, a second liquid is further filled from above downward in a direction parallel to the vertical direction.

5. The surface tension of the first liquid is 25 dyne / cm or less. The liquid filling method according to claim 4.

6. the first liquid is insoluble in the second liquid; the first liquid is non-volatile and has a specific gravity lower than that of the second liquid, and after the second liquid is filled, a portion of the first liquid moves above the second liquid to cover the entire upper surface of the second liquid; After the second liquid is filled, the first liquid that does not move above the second liquid and remains held on the surface of the film member on the liquid holding portion side is removed by discharging. The liquid filling method according to claim 4 or 5.

7. A film-like member having a nozzle hole for discharging a liquid; a support portion that supports the membrane member; a liquid holding portion that holds one or more liquids including the liquid, the liquid that is initially filled into the liquid discharge means is designated as a first liquid; a contact angle between the surface of the film member on the liquid holding portion side and the first liquid is at least less than 90 degrees; After filling with the first liquid, a second liquid is further filled, the first liquid is insoluble in the second liquid; the second liquid has a lower specific gravity than the first liquid and is non-volatile; A liquid filling method, characterized in that the second liquid is filled so as to cover an upper surface of the first liquid.

8. The supply rate of the first liquid is slower than the supply rate of the second liquid.

8. A method for filling a liquid according to any one of claims 4 to 7.

9. one of the first liquid and the second liquid contains cells; The other is a liquid that is not toxic to the cells.

9. A method for filling a liquid according to any one of claims 4 to 8.

10. The liquid that is not toxic to the cells is either silicone oil or liquid paraffin. The liquid filling method according to claim 9.

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