EP1765499A2 - Device for the production of microdroplets by means of liquid ejection and method of producing one such device - Google Patents
Device for the production of microdroplets by means of liquid ejection and method of producing one such deviceInfo
- Publication number
- EP1765499A2 EP1765499A2 EP05757262A EP05757262A EP1765499A2 EP 1765499 A2 EP1765499 A2 EP 1765499A2 EP 05757262 A EP05757262 A EP 05757262A EP 05757262 A EP05757262 A EP 05757262A EP 1765499 A2 EP1765499 A2 EP 1765499A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- plates
- liquid
- plate
- outlet
- chamber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000007788 liquid Substances 0.000 title claims abstract description 58
- 238000004519 manufacturing process Methods 0.000 title abstract description 6
- 238000006073 displacement reaction Methods 0.000 claims description 11
- 229920001971 elastomer Polymers 0.000 claims description 7
- 239000000806 elastomer Substances 0.000 claims description 7
- 239000002184 metal Substances 0.000 claims description 6
- 238000005452 bending Methods 0.000 abstract description 6
- 239000012528 membrane Substances 0.000 description 9
- 230000015572 biosynthetic process Effects 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 230000005284 excitation Effects 0.000 description 5
- 239000012530 fluid Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 239000000919 ceramic Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000007641 inkjet printing Methods 0.000 description 2
- 238000005459 micromachining Methods 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 229910001369 Brass Inorganic materials 0.000 description 1
- 201000005569 Gout Diseases 0.000 description 1
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- 238000004026 adhesive bonding Methods 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 239000003251 chemically resistant material Substances 0.000 description 1
- 238000013537 high throughput screening Methods 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 230000005499 meniscus Effects 0.000 description 1
- 239000011325 microbead Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 239000011241 protective layer Substances 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 230000011664 signaling Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 239000012815 thermoplastic material Substances 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B17/00—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups
- B05B17/04—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods
- B05B17/06—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations
- B05B17/0607—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations generated by electrical means, e.g. piezoelectric transducers
- B05B17/0638—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations generated by electrical means, e.g. piezoelectric transducers spray being produced by discharging the liquid or other fluent material through a plate comprising a plurality of orifices
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0046—Sequential or parallel reactions, e.g. for the synthesis of polypeptides or polynucleotides; Apparatus and devices for combinatorial chemistry or for making molecular arrays
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
- B01L3/02—Burettes; Pipettes
- B01L3/0241—Drop counters; Drop formers
- B01L3/0268—Drop counters; Drop formers using pulse dispensing or spraying, eg. inkjet type, piezo actuated ejection of droplets from capillaries
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B17/00—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups
- B05B17/04—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods
- B05B17/06—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations
- B05B17/0607—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations generated by electrical means, e.g. piezoelectric transducers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/135—Nozzles
- B41J2/14—Structure thereof only for on-demand ink jet heads
- B41J2/14201—Structure of print heads with piezoelectric elements
- B41J2/14233—Structure of print heads with piezoelectric elements of film type, deformed by bending and disposed on a diaphragm
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/135—Nozzles
- B41J2/14—Structure thereof only for on-demand ink jet heads
- B41J2/14201—Structure of print heads with piezoelectric elements
- B41J2/14274—Structure of print heads with piezoelectric elements of stacked structure type, deformed by compression/extension and disposed on a diaphragm
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
- B01J2219/00277—Apparatus
- B01J2219/00351—Means for dispensing and evacuation of reagents
- B01J2219/00378—Piezoelectric or ink jet dispensers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
- B01J2219/00277—Apparatus
- B01J2219/00497—Features relating to the solid phase supports
- B01J2219/00527—Sheets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
- B01J2219/00583—Features relative to the processes being carried out
- B01J2219/00603—Making arrays on substantially continuous surfaces
- B01J2219/00605—Making arrays on substantially continuous surfaces the compounds being directly bound or immobilised to solid supports
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
- B01J2219/00718—Type of compounds synthesised
- B01J2219/0072—Organic compounds
- B01J2219/00722—Nucleotides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B01L2200/00—Solutions for specific problems relating to chemical or physical laboratory apparatus
- B01L2200/12—Specific details about manufacturing devices
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B01L2300/00—Additional constructional details
- B01L2300/08—Geometry, shape and general structure
- B01L2300/0809—Geometry, shape and general structure rectangular shaped
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B01L2300/00—Additional constructional details
- B01L2300/08—Geometry, shape and general structure
- B01L2300/0832—Geometry, shape and general structure cylindrical, tube shaped
- B01L2300/0838—Capillaries
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B01L2400/00—Moving or stopping fluids
- B01L2400/04—Moving fluids with specific forces or mechanical means
- B01L2400/0403—Moving fluids with specific forces or mechanical means specific forces
- B01L2400/0433—Moving fluids with specific forces or mechanical means specific forces vibrational forces
- B01L2400/0439—Moving fluids with specific forces or mechanical means specific forces vibrational forces ultrasonic vibrations, vibrating piezo elements
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B01L2400/00—Moving or stopping fluids
- B01L2400/04—Moving fluids with specific forces or mechanical means
- B01L2400/0475—Moving fluids with specific forces or mechanical means specific mechanical means and fluid pressure
- B01L2400/0481—Moving fluids with specific forces or mechanical means specific mechanical means and fluid pressure squeezing of channels or chambers
Definitions
- the invention relates to a device for producing micro-drops by liquid ejection comprising a sealed chamber delimited mainly by lower and upper plates and by a side wall, the chamber having at least one liquid inlet and at least one liquid outlet. , the device comprising actuating means acting on at least one of the lower and upper plates to modulate the volume of the chamber so as to form drops at the outlet.
- the devices for producing micro-drops by ejecting liquid through an orifice make it possible to generate drops of liquid whose volume is typically between a few picoliters and a few nanoliters depending mainly on the size of the orifice.
- the formation of the drops is conventionally ensured by the generation of a pressure by means of a piezoelectric element.
- a second mode works by ejecting a single drop on each pulse of a pressure generation system (drops on demand), where a filament of liquid is rapidly propelled out of the device. This filament contracts under the effect of surface tension forces to form a drop of liquid.
- This mode of formation of single drops is presented, for example, in the document US6367925.
- Such devices find applications in many fields such as chemistry, pharmacy, biology, optics, micro-machining, etc.
- the devices are often based on the technologies used for inkjet printing, in particular on the implementation of silicon, glass and ceramics by micro-machining or photoengraving. These technologies lead to complex and expensive devices.
- US Pat. No. 6,367,925 describes a device for ejecting micro-drops comprising a tube of rectangular section having a flat side on which a piezoelectric material is disposed. Applying voltage pulses to the piezoelectric material allows micro-drops to be ejected.
- the tube has particular geometric shapes, the manufacture of which is expensive and difficult.
- Document DE19617924 describes a liquid micro-droplet ejection system comprising a sealed chamber having a liquid inlet and liquid outlets. A liquid excitation device causes the drops to be ejected through the outlets. This system is complex and difficult to implement.
- Document WO03089138 describes a microfluidic system comprising an elastomer layer in which channels are molded. The walls in contact with the fluid mainly consist of elastomer. The actuation by piezoelectric means modulates the passage of the liquid in the channels. This system makes it possible to move a liquid by pumping. The walls of the chambers in which the fluid is located, mainly made of flexible materials, dampen the pressure waves and do not allow the ejection of drops of liquid.
- the document US5828394 describes a drop ejection device comprising a substrate, a cylindrical side wall and an upper elastic membrane, defining a fluid reservoir. A piezoelectric plate having an ejection orifice is disposed on the membrane. A fluid inlet is formed in the side wall.
- the document EP1116590 describes an ink jet writing head using a stack of piezoelectric annular bodies and intermediate elements.
- the stack is arranged between a lower plate comprising an ink outlet and an upper plate comprising an ink inlet, so as to form a chamber.
- the actuation of the piezoelectric structure causes a radial deformation, allowing to modulate the interior volume of the chamber.
- the object of the invention is to remedy these drawbacks and, in particular, to make it possible to produce a simple and effective device for producing micro-drops by ejection of liquid, at low cost and facilitating the change of components of the device.
- the side wall is constituted by a substantially annular deformable seal of small thickness, disposed between the plates so as to allow the relative displacement of the all of the plates, in flexion and / or in translation, by crushing the joint, the lower and upper plates being more rigid than the deformable joint.
- Figures 1 and 2 show, respectively in top view and in section along the axis A-A, a particular embodiment of a device according to the invention.
- Figures 3 and 4 show, in section, two other particular embodiments of a device according to the invention.
- FIG. 5 illustrates a particular embodiment of a liquid outlet of a device according to the invention.
- FIG. 6 illustrates a particular embodiment of a substantially annular deformable joint of a device according to the invention.
- Figure 7 schematically illustrates the operation of a device according to the prior art.
- FIGS 8 and 9 schematically illustrate two particular modes of operation of the device according to the invention.
- the device for producing micro-drops by ejection of liquid shown in FIGS. 1 and 2 comprises a sealed chamber 1, having an inlet 2 for liquid and an outlet 3 for liquid.
- Chamber 1 is delimited mainly by rigid lower 5 and upper 6 plates and by a side wall constituted by a deformable seal 4 substantially annular of small thickness.
- the deformable seal 4 is disposed between the rigid lower 5 and upper 6 plates and has a flexibility allowing the relative displacement of all of the plates 5 and 6, in bending and or in translation, by crushing the deformable seal 4.
- the lower plates 5 and upper 6 are more rigid than the deformable seal 4, which in particular ensures that the deformable seal 4 is deformed and crushed between the plates 5 and 6.
- the rigid lower 5 and upper 6 plates are parallel.
- the deformable seal 4 is substantially annular and disposed between the plates 5 and 6.
- the deformable seal 4 shown in Figure 2 is constituted by an elastomer ring.
- the sealed chamber 1 is then formed by the lower face of the upper plate 6, by the upper face of the lower plate 5 and by the internal lateral walls of the deformable seal 4.
- the height of the chamber 1, corresponding to the thickness of the deformable joint 4, is very small compared to the diameter of the chamber 1, defined by the inside diameter of the substantially annular joint 4.
- the sealed chamber 1 is mainly constituted by rigid materials, in particular by the plates 5 and 6.
- the lower rigid plate 5 serves as a support for the other elements of the device and the outlet 3 for liquid is formed in the bottom plate 5.
- the device according to the invention comprises an actuator, preferably piezoelectric, acting on at least one of the lower 5 and upper 6 plates to modulate the volume of the chamber so as to form drops 10 at the outlet 3.
- the liquid is excited, for example by displacement of at least one of the lower 5 and upper 6 plates.
- the upper plate 6 is constituted by a piezoelectric plate 7, electrically excited on its lower and upper faces by means of lower 8 and upper 9 electrodes to which a voltage is applied electric Vex excitation.
- the piezoelectric plate 7 moves towards the interior of the chamber 1 and causes the formation of the drops 10 at the outlet 3 by a volume modulation of the chamber 1 and, possibly, by generation of a propagating pressure wave. , in bedroom 1, from top to bottom.
- the piezoelectric plate 7 then causes relative displacement of the rigid plates lower 5 and upper 6 and, thus, the excitation of the liquid. In the particular embodiment shown, this movement is transverse, that is to say perpendicular to the plates.
- the liquid outlet 3 is preferably formed in the lower plate 5, which has in particular the advantage of obtaining better control of the drops. Indeed, if a liquid outlet is formed in the piezoelectric plate 7, drops of liquids can deposit around the orifice and, by their inertia, modify the behavior of the piezoelectric plate 7 and, for example, change the frequency and the size of the drops ejected.
- the lower 8 and upper 9 electrodes can be connected to the upper face of the piezoelectric plate 7.
- the lower plate 5 is preferably made of a thermoplastic material possibly comprising a metal insert into which the outlet orifice 3 will be drilled.
- lower plate 5 preferably has a thickness of the order of 3 mm and sides of the order of 30mm.
- the deformable seal consists, for example, of an elastomer ring.
- the thickness of the deformable joint 4 is preferably between 0.02mm and 2mm.
- the application of a controlled pressure at the inlet 2 of chamber 1 makes it possible to control the position of the meniscus (in the drop-on-demand mode) or the liquid flow rate (in the jet break mode) at the outlet 3.
- the inlet 2 can, for example, be connected to a tank of liquid in slight depression or under pressure, for example of the order of 1 bar.
- Inlet 2 and outlet 3 have, for example, a cross section between 0.003 and 3 mm 2 .
- the geometry of the inlet 2 is calculated in order to allow a sufficient flow of the liquid to supply the chamber 1 as the drops 10 are ejected through the outlet 3.
- the geometry of the inlet 2 is such that the quantity of liquid emerging through the inlet 2 during the generation of pressure does not affect the ejection of the drops 10 through the outlet 3.
- the upper plate 6 is constituted by a flat metal plate 1 1 on which is disposed the piezoelectric plate 7, which is thus protected from the liquid, possibly chemically aggressive.
- the metal plate is traditionally made of brass. For certain applications, it can be covered with a protective layer (in Teflon for example) or else be made up of a chemically resistant material (stainless steel for example).
- the assembly of the piezoelectric plate 7 and the flat metal plate 11 can be constituted by a sound vibrator (English term: "buzzer") as used for signaling devices.
- the lower plate 5 has a groove 12, substantially annular in the plane of the plate 5, in which is positioned the deformable seal 4, constituted, for example, by an elastomer O-ring .
- the groove 12 can, for example, be machined in the lower plate 5 or in the upper plate 6, before assembly of the device. It is also possible to machine grooves 12 in each of the lower 5 and upper 6 plates. In the embodiment shown in FIG. 3, the inlet 2 for liquid is formed in the lower plate 5.
- the device comprises a clamping ring 13 disposed on the upper plate 6 and making it possible to disassemble and reassemble the ejection device quickly, for example to exchange parts.
- the clamping ring 13 and the bottom plate 5 can be fixed, for example, by screws 14, as shown in Figures 1 and 2, by a latching mechanism 15, as shown in Figure 3, or by any other means fixing, preferably reversible, without gluing or welding.
- FIG. 4 five orifices formed in the lower plate 5 constitute a plurality of liquid outlets 3.
- a stack (English term: "stac") of piezoelectric plates 7 is placed in contact with the upper plate 6.
- the liquid outlet 3 is constituted by a groove 16 disposed at the interface between the deformable seal 4 and the lower plate 5, in particular in the lower plate 5.
- the groove 16 can also be disposed in the upper plate 6 or in the deformable joint 4.
- the liquid outlet 3 is constituted by an opening 17 formed in the deformable joint 4 and having, for example, a square section of 70 micrometers on the side.
- the two particular embodiments of the liquid outlet 3 shown in FIGS. 5 and 6 make it possible to superpose several devices for producing micro-drops of liquid, the drops of liquid being ejected laterally.
- the device obtained has a small spacing between the outlets 3. It is preferably arranged vertically.
- the applications of such a device can, for example, be inkjet printing or high throughput screening.
- the sealed chamber 1 can comprise several liquid outlets 3, produced in the lower plate 5 and / or the upper plate 6 and / or in the deformable joint 4.
- the liquid inlet 2 can comprise one or more orifices and can be formed both in the lower plate 5 than in the upper plate 6 or in the deformable joint 4.
- the actuation or pressure means can be constituted by any actuator or mechanism making it possible to exert pressure perpendicularly to the upper plate 6 and preferably placed above the upper plate 6.
- the actuator can, for example, be glued, so as to obtain a displacement in bending, or be in free contact, so as to transmit a longitudinal and or transverse movement to the plate.
- the relative displacement of the lower 5 and upper 6 rigid plates is preferably a relative displacement transverse to the planes of the plates. However, one can also consider a displacement of one of the plates in its plane, so as to cause a shearing effect of the liquid.
- the device allows the ejection of liquids whose viscosity and surface tension can vary over a wide range thanks to the large contact surface between the liquid and the upper plate 6 and, thus, the piezoelectric plate 7 or the actuator d pressure excitation.
- the drops produced by the device according to the invention can be obtained for example by breaking a capillary jet (continuous jet) or else by punctual ejection of a drop (drops on request).
- the piezoelectric plate 7 constitutes an actuator or a transducer making it possible to generate a vibration.
- the device can operate outside the resonant frequency of the transducer. The performance of the device is thus not very sensitive to variations in loads on the transducer. Consequently, the device can operate at very low frequency for applications where it is desired to deposit a drop occasionally. For example, a single voltage window of a amplitude of 50V and a width of 100 ⁇ s produces the ejection of a single drop through an orifice of 150y / m.
- the diameter of the liquid outlet 3 can be greater than the diameter of a device according to the prior art, which makes it possible to generate larger drops of liquid.
- the outlet orifice preferably has a diameter of between 0.03mm and 0.3mm for the drop-on-demand mode and between 0.03 and 3mm for the continuous jet mode. In drop-on-demand mode, the ejected drops can thus have a volume of up to 25nl.
- the actuating means cause a deformation represented by an arrow 20.
- the rest position of the membrane 18 is shown by a dotted line 21. It is a deformation only of the central part 18a of the membrane 18, while the side wall 19, the substrate 22 and the periphery 18b of the membrane 18 remain stationary and do not deform.
- the rigid lower 5 and upper 6 plates are more rigid than the deformable joint 4, which allows a displacement in translation and / or in bending of all of one of the plates 5 and 6 under the action of / of the transducer and, thus, a relative displacement of all of the plates 5 and 6 in bending and / or in translation, accompanied by a deformation and a crushing of the deformable joint 4.
- the entire upper plate 6 can be bent easily.
- There is a pivot connection between the upper plate 6 and the deformable seal 4. The force applied to the plates 5 and / or 6 can thus be lower than in the device according to document US5828394.
- the bending of the whole of the upper plate 6 is represented by an arrow 23, in FIG. 8, and the position of rest of the upper plate 6 is represented by a dotted line 24.
- the translation of the whole of the upper plate 6 is represented by an arrow 25, in FIG. 9, and the rest position of the upper plate 6 is represented by a dotted line 26.
- the rigid plate or plates 5 and / or 6 moving under the action of the transducer (s) is preferably made of a material whose elastic modulus is between 1 and 300GPa (metal, ceramic, glass, thermoplastic ,. ..).
- the deformable joint preferably consists of a material whose elastic modulus is between 0.0005 and 0.1GPa, for example by an elastomer.
- the side wall of the chamber described in document EP1116590 must not have a small thickness.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Clinical Laboratory Science (AREA)
- Special Spraying Apparatus (AREA)
- Coating Apparatus (AREA)
- Reciprocating Pumps (AREA)
Abstract
The invention relates to a device for the production of microdroplets by means of liquid ejection. The inventive device consists of a sealed chamber (1) comprising a liquid inlet (2) and at least one liquid outlet (3) and, for example, an actuating piezoelectric plate (7) which causes droplets (10) to be ejected through the outlet (3). The chamber (1) is defined mainly by lower (5) and upper (6) rigid plates and an essentially-annular, thin deformable seal (4) which is disposed between the plates (5, 6) and which forms a lateral wall of the chamber (1). The piezoelectric plate (7) causes a relative movement between all of the lower (5) and upper (6) plates in terms of bending and/or translation, by compressing the deformable seal (4). According to the invention, the lower (5) and upper (6) plates are stiffer than the deformable seal (4).
Description
Dispositif de production de micro-gouttes par éjection de liquide et procédé de réalisation d'un tel dispositifDevice for producing micro-drops by ejecting liquid and method for producing such a device
Domaine technique de l'inventionTechnical field of the invention
L'invention concerne un dispositif de production de micro-gouttes par éjection de liquide comportant une chambre étanche délimitée principalement par des plaques inférieure et supérieure et par une paroi latérale, la chambre ayant au moins une entrée de liquide et au moins une sortie de liquide, le dispositif comportant des moyens d'actionnement agissant sur au moins une des plaques inférieure et supérieure pour moduler le volume de la chambre de manière à former des gouttes à la sortie.The invention relates to a device for producing micro-drops by liquid ejection comprising a sealed chamber delimited mainly by lower and upper plates and by a side wall, the chamber having at least one liquid inlet and at least one liquid outlet. , the device comprising actuating means acting on at least one of the lower and upper plates to modulate the volume of the chamber so as to form drops at the outlet.
État de la techniqueState of the art
Les dispositifs de production de micro-gouttes par éjection de liquide à travers un orifice permettent de générer des gouttes de liquide dont le volume est typiquement compris entre quelques picolitres et quelques nanolitres dépendant principalement de la taille de l'orifice. La formation des gouttes est classiquement assurée par la génération d'une pression au moyen d'un élément piézoélectrique. On distingue typiquement deux modes de formation des gouttes : Un premier mode fonctionne par brisure d'un jet continu de liquide, où l'instabilité naturelle du jet est contrôlée par la génération d'une pression modulée à une fréquence permettant d'obtenir un train de gouttelettes, de taille uniforme. Ce mode de formation de goutte est présenté, par exemple, dans le document US5337071. Un second mode fonctionne par éjection d'une goutte unique à chaque impulsion d'un système de génération de pression (gouttes à la demande), où un filament de liquide est propulsé rapidement hors du dispositif. Ce filament se contracte sous l'effet des forces de tension superficielle pour former une goutte de liquide. Ce mode de formation de gouttes uniques est présenté, par exemple, dans le document US6367925.
De tels dispositifs trouvent des applications dans de nombreux domaines comme la chimie, la pharmacie, la biologie, l'optique, le micro-usinage etc.. Parmi les différentes applications, on peut citer la fabrication de micro-billes, la synthèse d'ADN ou encore la fabrication de micro-lentilles par éjection de polymère. Les dispositifs sont souvent basés sur les technologies utilisées pour l'impression par jet d'encre, notamment sur la mise en œuvre de silicium, de verre et de céramiques par micro-usinage ou photogravure. Ces technologies conduisent à des dispositifs complexes et coûteux.The devices for producing micro-drops by ejecting liquid through an orifice make it possible to generate drops of liquid whose volume is typically between a few picoliters and a few nanoliters depending mainly on the size of the orifice. The formation of the drops is conventionally ensured by the generation of a pressure by means of a piezoelectric element. There are typically two modes of drop formation: A first mode works by breaking a continuous jet of liquid, where the natural instability of the jet is controlled by the generation of a pressure modulated at a frequency to obtain a train droplets, uniform in size. This mode of gout formation is presented, for example, in the document US5337071. A second mode works by ejecting a single drop on each pulse of a pressure generation system (drops on demand), where a filament of liquid is rapidly propelled out of the device. This filament contracts under the effect of surface tension forces to form a drop of liquid. This mode of formation of single drops is presented, for example, in the document US6367925. Such devices find applications in many fields such as chemistry, pharmacy, biology, optics, micro-machining, etc. Among the different applications, one can cite the manufacture of micro-beads, the synthesis of DNA or the manufacture of micro-lenses by polymer ejection. The devices are often based on the technologies used for inkjet printing, in particular on the implementation of silicon, glass and ceramics by micro-machining or photoengraving. These technologies lead to complex and expensive devices.
Par ailleurs, l'utilisation de divers liquides industriels, contenant plusieurs phases voire des particules solides, entraîne des bouchages de buses de sortie ce qui nécessite souvent le remplacement du dispositif entier.Furthermore, the use of various industrial liquids, containing several phases or even solid particles, leads to blockage of outlet nozzles, which often requires replacement of the entire device.
Le document US6367925 décrit un dispositif d'éjection de micro-gouttes comportant un tube de section rectangulaire ayant un côté plat sur lequel est disposé un matériau piézoélectrique. L'application d'impulsions de tension au matériau piézoélectrique permet d'éjecter des micro-gouttes. Le tube a des formes géométriques particulières dont la fabrication est coûteuse et difficile.The document US Pat. No. 6,367,925 describes a device for ejecting micro-drops comprising a tube of rectangular section having a flat side on which a piezoelectric material is disposed. Applying voltage pulses to the piezoelectric material allows micro-drops to be ejected. The tube has particular geometric shapes, the manufacture of which is expensive and difficult.
Le document DE19617924 décrit un système d'éjection de micro-gouttes de liquide comportant une chambre étanche ayant une entrée de liquide et des sorties de liquide. Un dispositif d'excitation du liquide provoque l'éjection des gouttes par les sorties. Ce système est complexe et difficile à mettre en œuvre.Document DE19617924 describes a liquid micro-droplet ejection system comprising a sealed chamber having a liquid inlet and liquid outlets. A liquid excitation device causes the drops to be ejected through the outlets. This system is complex and difficult to implement.
Le document WO03089138 décrit un système microfluidique comportant une couche d'élastomère dans laquelle sont moulés des canaux. Les parois en contact avec le fluide sont principalement constituées d'élastomère. L'actionnement par des moyens piézoélectriques module le passage du liquide dans les canaux. Ce système permet de déplacer un liquide par pompage. Les parois des chambres dans lesquelles se trouve le fluide, principalement constituées de matériaux souples, amortissent les ondes de pression et ne permettent pas l'éjection de gouttes de liquide.
Le document US5828394 décrit un dispositif d'éjection de gouttes comportant un substrat, une paroi latérale cylindrique et une membrane élastique supérieure, définissant un réservoir de fluide. Une plaque piézoélectrique comportant un orifice d'éjection est disposée sur la membrane. Une entrée de fluide est formée dans la paroi latérale.Document WO03089138 describes a microfluidic system comprising an elastomer layer in which channels are molded. The walls in contact with the fluid mainly consist of elastomer. The actuation by piezoelectric means modulates the passage of the liquid in the channels. This system makes it possible to move a liquid by pumping. The walls of the chambers in which the fluid is located, mainly made of flexible materials, dampen the pressure waves and do not allow the ejection of drops of liquid. The document US5828394 describes a drop ejection device comprising a substrate, a cylindrical side wall and an upper elastic membrane, defining a fluid reservoir. A piezoelectric plate having an ejection orifice is disposed on the membrane. A fluid inlet is formed in the side wall.
D'autres principes de fonctionnement, par exemple par déformation radiale, ont été proposés. Le document EP1116590, par exemple, décrit une tête d'écriture à jet d'encre utilisant un empilement de corps annulaires piézoélectriques et d'éléments intermédiaires. L'empilement est disposé entre une plaque inférieure comportant une sortie d'encre et une plaque supérieure comportant une entrée d'encre, de manière à former une chambre. L'actionnement de la structure piézoélectrique provoque une déformation radiale, permettant de moduler le volume intérieur de la chambre.Other operating principles, for example by radial deformation, have been proposed. The document EP1116590, for example, describes an ink jet writing head using a stack of piezoelectric annular bodies and intermediate elements. The stack is arranged between a lower plate comprising an ink outlet and an upper plate comprising an ink inlet, so as to form a chamber. The actuation of the piezoelectric structure causes a radial deformation, allowing to modulate the interior volume of the chamber.
Objet de l'inventionSubject of the invention
L'invention a pour but de remédier à ces inconvénients et, en particulier, de permettre de réaliser un dispositif simple et efficace de production de micro-gouttes par éjection de liquide, à faible coût et facilitant le changement de composants du dispositif.The object of the invention is to remedy these drawbacks and, in particular, to make it possible to produce a simple and effective device for producing micro-drops by ejection of liquid, at low cost and facilitating the change of components of the device.
Selon l'invention, ce but est atteint par les revendications annexées et, en particulier, par le fait que la paroi latérale est constituée par un joint deformable sensiblement annulaire de faible épaisseur, disposé entre les plaques de manière à permettre le déplacement relatif de la totalité des plaques, en flexion et/ou en translation, par écrasement du joint, les plaques inférieure et supérieure étant plus rigides que le joint deformable.
Description sommaire des dessinsAccording to the invention, this object is achieved by the appended claims and, in particular, by the fact that the side wall is constituted by a substantially annular deformable seal of small thickness, disposed between the plates so as to allow the relative displacement of the all of the plates, in flexion and / or in translation, by crushing the joint, the lower and upper plates being more rigid than the deformable joint. Brief description of the drawings
D'autres avantages et caractéristiques ressortiront plus clairement de la description qui va suivre de modes particuliers de réalisation de l'invention donnés à titre d'exemples non limitatifs et représentés aux dessins annexés, dans lesquels :Other advantages and characteristics will emerge more clearly from the description which follows of particular embodiments of the invention given by way of nonlimiting examples and represented in the appended drawings, in which:
Les figures 1 et 2 représentent, respectivement en vue de dessus et en coupe selon l'axe A-A, un mode de réalisation particulier d'un dispositif selon l'invention.Figures 1 and 2 show, respectively in top view and in section along the axis A-A, a particular embodiment of a device according to the invention.
Les figures 3 et 4 représentent, en coupe, deux autres modes de réalisation particuliers d'un dispositif selon l'invention.Figures 3 and 4 show, in section, two other particular embodiments of a device according to the invention.
La figure 5 illustre un mode de réalisation particulier d'une sortie de liquide d'un dispositif selon l'invention.FIG. 5 illustrates a particular embodiment of a liquid outlet of a device according to the invention.
La figure 6 illustre un mode de réalisation particulier d'un joint deformable sensiblement annulaire d'un dispositif selon l'invention.FIG. 6 illustrates a particular embodiment of a substantially annular deformable joint of a device according to the invention.
La figure 7 illustre schématiquement le fonctionnement d'un dispositif selon l'art antérieur.Figure 7 schematically illustrates the operation of a device according to the prior art.
Les figures 8 et 9 illustrent schématiquement deux modes de fonctionnement particuliers du dispositif selon l'invention.Figures 8 and 9 schematically illustrate two particular modes of operation of the device according to the invention.
Description de modes particuliers de réalisationDescription of particular embodiments
Le dispositif de production de micro-gouttes par éjection de liquide représenté aux figures 1 et 2 comporte une chambre 1 étanche, ayant une entrée 2 de liquide et une sortie 3 de liquide. La chambre 1 est délimitée principalement par des plaques rigides inférieure 5 et supérieure 6 et par une paroi latérale constituée par un joint deformable 4 sensiblement annulaire de faible épaisseur. Le joint deformable 4 est disposé entre les plaques rigides inférieure 5 et supérieure 6 et présente une souplesse permettant le déplacement relatif de la totalité des plaques 5 et 6, en flexion et ou en translation, par écrasement du joint deformable 4. Les plaques inférieure 5 et supérieure 6 sont plus rigides que le joint deformable 4, ce qui assure notamment que le joint deformable 4 est déformé et écrasé entre les plaques 5 et 6.
Sur la figure 2, les plaques rigides inférieure 5 et supérieure 6 sont parallèles. Le joint deformable 4 est sensiblement annulaire et disposé entre les plaques 5 et 6.The device for producing micro-drops by ejection of liquid shown in FIGS. 1 and 2 comprises a sealed chamber 1, having an inlet 2 for liquid and an outlet 3 for liquid. Chamber 1 is delimited mainly by rigid lower 5 and upper 6 plates and by a side wall constituted by a deformable seal 4 substantially annular of small thickness. The deformable seal 4 is disposed between the rigid lower 5 and upper 6 plates and has a flexibility allowing the relative displacement of all of the plates 5 and 6, in bending and or in translation, by crushing the deformable seal 4. The lower plates 5 and upper 6 are more rigid than the deformable seal 4, which in particular ensures that the deformable seal 4 is deformed and crushed between the plates 5 and 6. In FIG. 2, the rigid lower 5 and upper 6 plates are parallel. The deformable seal 4 is substantially annular and disposed between the plates 5 and 6.
Le joint deformable 4 représenté à la figure 2 est constitué par un anneau en elastomère. La chambre 1 étanche est alors formée par la face inférieure de la plaque supérieure 6, par la face supérieure de la plaque inférieure 5 et par les parois latérales internes du joint deformable 4. La hauteur de la chambre 1 , correspondant à l'épaisseur du joint deformable 4, est très faible par rapport au diamètre de la chambre 1 , définie par le diamètre intérieur du joint 4 sensiblement annulaire. Ainsi, la chambre 1 étanche est principalement constituée par des matériaux rigides, notamment par les plaques 5 et 6. Sur les figures 1 et 2, la plaque rigide inférieure 5 sert de support pour les autres éléments du dispositif et la sortie 3 de liquide est formée dans la plaque inférieure 5.The deformable seal 4 shown in Figure 2 is constituted by an elastomer ring. The sealed chamber 1 is then formed by the lower face of the upper plate 6, by the upper face of the lower plate 5 and by the internal lateral walls of the deformable seal 4. The height of the chamber 1, corresponding to the thickness of the deformable joint 4, is very small compared to the diameter of the chamber 1, defined by the inside diameter of the substantially annular joint 4. Thus, the sealed chamber 1 is mainly constituted by rigid materials, in particular by the plates 5 and 6. In FIGS. 1 and 2, the lower rigid plate 5 serves as a support for the other elements of the device and the outlet 3 for liquid is formed in the bottom plate 5.
Le dispositif selon l'invention comporte un actionneur, de préférence piézoélectrique, agissant sur au moins une des plaques inférieure 5 et supérieure 6 pour moduler le volume de la chambre de manière à former des gouttes 10 à la sortie 3. Ainsi, le liquide est excité, par exemple par déplacement d'au moins une des plaques inférieure 5 et supérieure 6.The device according to the invention comprises an actuator, preferably piezoelectric, acting on at least one of the lower 5 and upper 6 plates to modulate the volume of the chamber so as to form drops 10 at the outlet 3. Thus, the liquid is excited, for example by displacement of at least one of the lower 5 and upper 6 plates.
Dans le mode de réalisation particulier représenté aux figures 1 et 2, la plaque supérieure 6 est constituée par une plaque piézoélectrique 7, excitée électriquement sur ses faces inférieure et supérieure par l'intermédiaire d'électrodes inférieure 8 et supérieure 9 auxquelles est appliquée une tension électrique d'excitation Vex. Ainsi, la plaque piézoélectrique 7 se déplace vers l'intérieur de la chambre 1 et provoque la formation des gouttes 10 à la sortie 3 par une modulation de volume de la chambre 1 et, éventuellement, par génération d'une onde de pression se propageant, dans la chambre 1 , du haut vers le bas. La plaque piézoélectrique 7 provoque alors un déplacement relatif des plaques rigides inférieure 5 et supérieure 6 et, ainsi, l'excitation du liquide. Dans le mode de réalisation particulier représenté, ce déplacement est transversal, c'est-à-dire perpendiculaire aux plaques.
Lorsque l'excitation du liquide est provoquée du côté de la plaque supérieure 6, la sortie 3 de liquide est, de préférence, formée dans la plaque inférieure 5, ce qui présente notamment l'avantage d'obtenir un meilleur contrôle des gouttes. En effet, si une sortie de liquide est formée dans la plaque piézoélectrique 7, des gouttes de liquides peuvent se déposer autour de l'orifice et, par leur inertie, modifier le comportement de la plaque piézoélectrique 7 et, par exemple, changer la fréquence et la taille des gouttes éjectées.In the particular embodiment shown in Figures 1 and 2, the upper plate 6 is constituted by a piezoelectric plate 7, electrically excited on its lower and upper faces by means of lower 8 and upper 9 electrodes to which a voltage is applied electric Vex excitation. Thus, the piezoelectric plate 7 moves towards the interior of the chamber 1 and causes the formation of the drops 10 at the outlet 3 by a volume modulation of the chamber 1 and, possibly, by generation of a propagating pressure wave. , in bedroom 1, from top to bottom. The piezoelectric plate 7 then causes relative displacement of the rigid plates lower 5 and upper 6 and, thus, the excitation of the liquid. In the particular embodiment shown, this movement is transverse, that is to say perpendicular to the plates. When the excitation of the liquid is caused on the side of the upper plate 6, the liquid outlet 3 is preferably formed in the lower plate 5, which has in particular the advantage of obtaining better control of the drops. Indeed, if a liquid outlet is formed in the piezoelectric plate 7, drops of liquids can deposit around the orifice and, by their inertia, modify the behavior of the piezoelectric plate 7 and, for example, change the frequency and the size of the drops ejected.
Les électrodes inférieure 8 et supérieure 9 peuvent être connectées à la face supérieure de la plaque piézoélectrique 7. La plaque inférieure 5 est, de préférence, en un matériau thermoplastique comportant éventuellement un insert métallique dans lequel sera percé l'orifice de sortie 3. La plaque inférieure 5 a, de préférence, une épaisseur de l'ordre de 3 mm et des côtés de l'ordre de 30mm. Dans le mode de réalisation particulier représenté sur les figures 1 et 2, le joint deformable est constitué, par exemple, d'un anneau en elastomère. L'épaisseur du joint deformable 4 est, de préférence, comprise entre 0,02mm et 2mm.The lower 8 and upper 9 electrodes can be connected to the upper face of the piezoelectric plate 7. The lower plate 5 is preferably made of a thermoplastic material possibly comprising a metal insert into which the outlet orifice 3 will be drilled. lower plate 5 preferably has a thickness of the order of 3 mm and sides of the order of 30mm. In the particular embodiment shown in Figures 1 and 2, the deformable seal consists, for example, of an elastomer ring. The thickness of the deformable joint 4 is preferably between 0.02mm and 2mm.
L'application d'une pression contrôlée au niveau de l'entrée 2 de la chambre 1 permet de maîtriser la position du ménisque (dans le mode de gouttes à la demande) ou le débit de liquide (dans le mode de brisure de jet) au niveau de la sortie 3. L'entrée 2 peut, par exemple, être connectée à un réservoir de liquide en légère dépression ou bien sous pression, par exemple de l'ordre de 1 bar. L'entrée 2 et la sortie 3 ont, par exemple, une section comprise entre 0,003 et 3 mm2. La géométrie de l'entrée 2 est calculée afin de permettre un débit suffisant du liquide pour alimenter la chambre 1 au fur et à mesure que les gouttes 10 sont éjectées par la sortie 3. Par ailleurs, la géométrie de l'entrée 2 est telle que la quantité de liquide ressortant par l'entrée 2 lors de la génération de pression n'affecte pas l'éjection des gouttes 10 par la sortie 3.The application of a controlled pressure at the inlet 2 of chamber 1 makes it possible to control the position of the meniscus (in the drop-on-demand mode) or the liquid flow rate (in the jet break mode) at the outlet 3. The inlet 2 can, for example, be connected to a tank of liquid in slight depression or under pressure, for example of the order of 1 bar. Inlet 2 and outlet 3 have, for example, a cross section between 0.003 and 3 mm 2 . The geometry of the inlet 2 is calculated in order to allow a sufficient flow of the liquid to supply the chamber 1 as the drops 10 are ejected through the outlet 3. Furthermore, the geometry of the inlet 2 is such that the quantity of liquid emerging through the inlet 2 during the generation of pressure does not affect the ejection of the drops 10 through the outlet 3.
Sur la figure 3, la plaque supérieure 6 est constituée par une plaque métallique 1 1 plane sur laquelle est disposée la plaque piézoélectrique 7, qui est ainsi protégée du liquide, éventuellement chimiquement agressif. La plaque métallique est traditionnellement en laiton. Pour certaines applications, elle peut être recouverte d'une couche de protection (en téflon par exemple) ou bien être constituée d'un
matériau résistant chimiquement (inox par exemple). L'ensemble de la plaque piézoélectrique 7 et de la plaque métallique 11 plane peut être constitué par un vibreur sonore (terme anglais : « buzzer ») tel que utilisé pour des dispositifs de signalisation. Dans le mode de réalisation particulier représenté à la figure 3, la plaque inférieure 5 comporte une gorge 12, sensiblement annulaire dans le plan de la plaque 5, dans laquelle est positionné le joint deformable 4, constitué, par exemple, par un joint torique elastomère. La gorge 12 peut, par exemple, être usinée dans la plaque inférieure 5 ou dans la plaque supérieure 6, avant assemblage du dispositif. On peut également usiner des gorges 12 dans chacune des plaques inférieure 5 et supérieure 6. Dans le mode de réalisation représenté à la figure 3, l'entrée 2 de liquide est formée dans la plaque inférieure 5.In Figure 3, the upper plate 6 is constituted by a flat metal plate 1 1 on which is disposed the piezoelectric plate 7, which is thus protected from the liquid, possibly chemically aggressive. The metal plate is traditionally made of brass. For certain applications, it can be covered with a protective layer (in Teflon for example) or else be made up of a chemically resistant material (stainless steel for example). The assembly of the piezoelectric plate 7 and the flat metal plate 11 can be constituted by a sound vibrator (English term: "buzzer") as used for signaling devices. In the particular embodiment shown in Figure 3, the lower plate 5 has a groove 12, substantially annular in the plane of the plate 5, in which is positioned the deformable seal 4, constituted, for example, by an elastomer O-ring . The groove 12 can, for example, be machined in the lower plate 5 or in the upper plate 6, before assembly of the device. It is also possible to machine grooves 12 in each of the lower 5 and upper 6 plates. In the embodiment shown in FIG. 3, the inlet 2 for liquid is formed in the lower plate 5.
Sur les figures 1 à 3, le dispositif comporte une bague de serrage 13 disposée sur la plaque supérieure 6 et permettant de démonter et de remonter rapidement le dispositif d'éjection, par exemple pour échanger des pièces. La bague de serrage 13 et la plaque inférieure 5 peuvent être fixées, par exemple, par des vis 14, comme représenté aux figures 1 et 2, par un mécanisme d'encliquetage 15, comme représenté à la figure 3, ou par tout autre moyen de fixation, de préférence réversible, sans collage ni soudure.In Figures 1 to 3, the device comprises a clamping ring 13 disposed on the upper plate 6 and making it possible to disassemble and reassemble the ejection device quickly, for example to exchange parts. The clamping ring 13 and the bottom plate 5 can be fixed, for example, by screws 14, as shown in Figures 1 and 2, by a latching mechanism 15, as shown in Figure 3, or by any other means fixing, preferably reversible, without gluing or welding.
Sur la figure 4, cinq orifices formés dans la plaque inférieure 5 constituent une pluralité de sorties 3 de liquide. Un empilement (terme anglais : « stac ») de plaques piézoélectriques 7 est disposé au contact de la plaque supérieure 6.In FIG. 4, five orifices formed in the lower plate 5 constitute a plurality of liquid outlets 3. A stack (English term: "stac") of piezoelectric plates 7 is placed in contact with the upper plate 6.
Sur la figure 5, la sortie 3 de liquide est constituée par une rainure 16 disposée à l'interface entre le joint deformable 4 et la plaque inférieure 5, notamment dans la plaque inférieure 5. La rainure 16 peut également être disposée dans la plaque supérieure 6 ou dans le joint deformable 4.In FIG. 5, the liquid outlet 3 is constituted by a groove 16 disposed at the interface between the deformable seal 4 and the lower plate 5, in particular in the lower plate 5. The groove 16 can also be disposed in the upper plate 6 or in the deformable joint 4.
Sur la figure 6, la sortie 3 de liquide est constituée par une ouverture 17 formée dans le joint deformable 4 et ayant, par exemple, une section carrée de 70 micromètres de côté. Les deux modes de réalisation particuliers de la sortie 3 de liquide représentés aux figures 5 et 6 permettent de superposer plusieurs dispositifs de production de micro-gouttes de liquide, les gouttes de liquide étant
éjectées latéralement. Le dispositif obtenu présente un faible écartement entre les sorties 3. Il est, de préférence, disposé verticalement. Les applications d'un tel dispositif peuvent, par exemple, être l'impression par jet d'encre ou le criblage à haut débit.In FIG. 6, the liquid outlet 3 is constituted by an opening 17 formed in the deformable joint 4 and having, for example, a square section of 70 micrometers on the side. The two particular embodiments of the liquid outlet 3 shown in FIGS. 5 and 6 make it possible to superpose several devices for producing micro-drops of liquid, the drops of liquid being ejected laterally. The device obtained has a small spacing between the outlets 3. It is preferably arranged vertically. The applications of such a device can, for example, be inkjet printing or high throughput screening.
L'invention n'est pas limitée aux modes de réalisation représentés. En particulier, la chambre 1 étanche peut comporter plusieurs sorties 3 de liquide, réalisées dans la plaque inférieure 5 et/ou la plaque supérieure 6 et/ou dans le joint deformable 4. L'entrée 2 de liquide peut comporter un ou plusieurs orifices et peut être formée aussi bien dans la plaque inférieure 5 que dans la plaque supérieure 6 ou dans le joint deformable 4. Par ailleurs, les moyens d'actionnement, de pression, peuvent être constitués par tout actionneur ou mécanisme permettant d'exercer une pression perpendiculairement à la plaque supérieure 6 et disposé, de préférence, au-dessus de la plaque supérieure 6. L'actionneur peut, par exemple, être collé, de manière à obtenir un déplacement en flexion, ou être en contact libre, de manière à transmettre un déplacement longitudinal et ou transversal à la plaque. Le déplacement relatif des plaques rigides inférieure 5 et supérieure 6 est, de préférence, un déplacement relatif transversal aux plans des plaques. Cependant, on peut également envisager un déplacement d'une des plaques dans son plan, de manière à provoquer un effet de cisaillement du liquide.The invention is not limited to the embodiments shown. In particular, the sealed chamber 1 can comprise several liquid outlets 3, produced in the lower plate 5 and / or the upper plate 6 and / or in the deformable joint 4. The liquid inlet 2 can comprise one or more orifices and can be formed both in the lower plate 5 than in the upper plate 6 or in the deformable joint 4. Furthermore, the actuation or pressure means can be constituted by any actuator or mechanism making it possible to exert pressure perpendicularly to the upper plate 6 and preferably placed above the upper plate 6. The actuator can, for example, be glued, so as to obtain a displacement in bending, or be in free contact, so as to transmit a longitudinal and or transverse movement to the plate. The relative displacement of the lower 5 and upper 6 rigid plates is preferably a relative displacement transverse to the planes of the plates. However, one can also consider a displacement of one of the plates in its plane, so as to cause a shearing effect of the liquid.
Le dispositif permet l'éjection de liquides dont la viscosité et la tension de surface peuvent varier dans une large gamme grâce à la grande surface de contact entre le liquide et la plaque supérieure 6 et, ainsi, la plaque piézoélectrique 7 ou l'actionneur d'excitation de pression. Les gouttes produites par le dispositif selon l'invention peuvent être obtenues par exemple par brisure d'un jet capillaire (jet continu) ou bien par éjection ponctuelle d'une goutte (gouttes à la demande).The device allows the ejection of liquids whose viscosity and surface tension can vary over a wide range thanks to the large contact surface between the liquid and the upper plate 6 and, thus, the piezoelectric plate 7 or the actuator d pressure excitation. The drops produced by the device according to the invention can be obtained for example by breaking a capillary jet (continuous jet) or else by punctual ejection of a drop (drops on request).
La plaque piézoélectrique 7 constitue un actionneur ou un transducteur permettant de générer une vibration. Le dispositif peut fonctionner hors de la fréquence de résonance du transducteur. Les performances du dispositif sont ainsi peu sensibles aux variations de charges sur le transducteur. Par conséquent, le dispositif peut fonctionner à très basse fréquence pour des applications où l'on souhaite déposer une goutte ponctuellement. Par exemple, un créneau de tension unique d'une
amplitude de 50V et d'une largeur de 100 μs produit l'éjection d'une goutte unique par un orifice de 150y/m.The piezoelectric plate 7 constitutes an actuator or a transducer making it possible to generate a vibration. The device can operate outside the resonant frequency of the transducer. The performance of the device is thus not very sensitive to variations in loads on the transducer. Consequently, the device can operate at very low frequency for applications where it is desired to deposit a drop occasionally. For example, a single voltage window of a amplitude of 50V and a width of 100 μs produces the ejection of a single drop through an orifice of 150y / m.
Grâce à une meilleure efficacité à basse fréquence du dispositif selon l'invention, le diamètre de la sortie 3 de liquide peut être supérieur au diamètre d'un dispositif selon l'art antérieur, ce qui permet de générer de plus grosses gouttes de liquide. L'orifice de sortie a, de préférence, un diamètre compris entre 0,03mm et 0,3mm pour le mode de gouttes à la demande et entre 0.03 et 3mm pour le mode de jet continu. En mode de gouttes à la demande, les gouttes éjectées peuvent ainsi avoir un volume allant jusqu'à 25nl.Thanks to better efficiency at low frequency of the device according to the invention, the diameter of the liquid outlet 3 can be greater than the diameter of a device according to the prior art, which makes it possible to generate larger drops of liquid. The outlet orifice preferably has a diameter of between 0.03mm and 0.3mm for the drop-on-demand mode and between 0.03 and 3mm for the continuous jet mode. In drop-on-demand mode, the ejected drops can thus have a volume of up to 25nl.
Selon le document US5828394, comme représenté à la figure 7, la membrane 18 supérieure étant élastique et la paroi latérale 19 étant rigide, les moyens d'actionnement provoquent une déformation représentée par une flèche 20. La position de repos de la membrane 18 est représentée par une ligne en pointillés 21. C'est une déformation uniquement de la partie centrale 18a de la membrane 18, tandis que la paroi latérale 19, le substrat 22 et la périphérie 18b de la membrane 18 restent immobiles et ne se déforment pas. Il y a une liaison d'encastrement entre la périphérie 18b de la membrane 18 et la paroi latérale 19. Cet effet est notamment dû à l'élasticité de la membrane 18 qui est supérieure à l'élasticité de la paroi latérale 19 qui est rigide et qui immobilise ainsi la périphérie 18b de la membrane 18.According to document US5828394, as shown in FIG. 7, the upper membrane 18 being elastic and the side wall 19 being rigid, the actuating means cause a deformation represented by an arrow 20. The rest position of the membrane 18 is shown by a dotted line 21. It is a deformation only of the central part 18a of the membrane 18, while the side wall 19, the substrate 22 and the periphery 18b of the membrane 18 remain stationary and do not deform. There is an embedding connection between the periphery 18b of the membrane 18 and the side wall 19. This effect is notably due to the elasticity of the membrane 18 which is greater than the elasticity of the side wall 19 which is rigid and which thus immobilizes the periphery 18b of the membrane 18.
Dans le dispositif selon l'invention, les plaques rigides inférieure 5 et supérieure 6 sont plus rigides que le joint deformable 4, ce qui permet un déplacement en translation et/ou en flexion de la totalité d'une des plaques 5 et 6 sous l'action des/du transducteur et, ainsi, un déplacement relatif de la totalité des plaques 5 et 6 en flexion et/ou en translation, accompagné par une déformation et un écrasement du joint deformable 4. Comme représenté aux figures 8 et 9, grâce au joint deformable 4, la flexion de la totalité de la plaque supérieure 6 peut facilement être effectuée. Il y a une liaison pivot entre la plaque supérieure 6 et le joint deformable 4. La force appliquée sur les plaques 5 et/ou 6 peut ainsi être plus faible que dans le dispositif selon le document US5828394. La flexion de la totalité de la plaque supérieure 6 est représentée par une flèche 23, sur la figure 8, et la position de
repos de la plaque supérieure 6 est représentée par une ligne en pointillés 24. La translation de la totalité de la plaque supérieure 6 est représentée par une flèche 25, sur la figure 9, et la position de repos de la plaque supérieure 6 est représentée par une ligne en pointillés 26.In the device according to the invention, the rigid lower 5 and upper 6 plates are more rigid than the deformable joint 4, which allows a displacement in translation and / or in bending of all of one of the plates 5 and 6 under the action of / of the transducer and, thus, a relative displacement of all of the plates 5 and 6 in bending and / or in translation, accompanied by a deformation and a crushing of the deformable joint 4. As shown in FIGS. 8 and 9, thanks at the deformable joint 4, the entire upper plate 6 can be bent easily. There is a pivot connection between the upper plate 6 and the deformable seal 4. The force applied to the plates 5 and / or 6 can thus be lower than in the device according to document US5828394. The bending of the whole of the upper plate 6 is represented by an arrow 23, in FIG. 8, and the position of rest of the upper plate 6 is represented by a dotted line 24. The translation of the whole of the upper plate 6 is represented by an arrow 25, in FIG. 9, and the rest position of the upper plate 6 is represented by a dotted line 26.
La ou les plaques rigides 5 et/ou 6 se déplaçant sous l'action du/des transducteur est de préférence constitué d'un matériau dont le module d'élasticité est compris entre 1 et 300GPa (métal, céramique, verre, thermoplastique,...). Le joint deformable est constitué, de préférence, d'un matériau dont le module d'élasticité est compris entre 0,0005 et 0,1GPa, par exemple par un elastomère.The rigid plate or plates 5 and / or 6 moving under the action of the transducer (s) is preferably made of a material whose elastic modulus is between 1 and 300GPa (metal, ceramic, glass, thermoplastic ,. ..). The deformable joint preferably consists of a material whose elastic modulus is between 0.0005 and 0.1GPa, for example by an elastomer.
Contrairement au dispositif selon l'invention, afin d'obtenir une modulation de volume efficace, la paroi latérale de la chambre décrite dans le document EP1116590 ne doit pas présenter une faible épaisseur.
Unlike the device according to the invention, in order to obtain an effective volume modulation, the side wall of the chamber described in document EP1116590 must not have a small thickness.
Claims
1. Dispositif de production de micro-gouttes par éjection de liquide comportant une chambre (1) étanche délimitée principalement par des plaques inférieure (5) et supérieure (6) et par une paroi latérale, la chambre (1) ayant au moins une entrée (2) de liquide et au moins une sortie (3) de liquide, le dispositif comportant des moyens d'actionnement agissant sur au moins une des plaques inférieure (5) et supérieure (6) pour moduler le volume de la chambre de manière à former des gouttes (10) à la sortie (3), dispositif caractérisé en ce que la paroi latérale est constituée par un joint deformable (4) sensiblement annulaire de faible épaisseur, disposé entre les plaques (5, 6) de manière à permettre le déplacement relatif de la totalité des plaques (5, 6), en flexion et/ou en translation, par écrasement du joint deformable (4), les plaques inférieure (5) et supérieure (6) étant plus rigides que le joint deformable (4).1. Device for producing micro-drops by ejection of liquid comprising a sealed chamber (1) delimited mainly by lower (5) and upper (6) plates and by a side wall, the chamber (1) having at least one inlet (2) of liquid and at least one outlet (3) of liquid, the device comprising actuating means acting on at least one of the lower (5) and upper (6) plates to modulate the volume of the chamber so as to forming drops (10) at the outlet (3), device characterized in that the side wall is constituted by a deformable seal (4) substantially annular of small thickness, disposed between the plates (5, 6) so as to allow the relative displacement of all the plates (5, 6), in flexion and / or in translation, by crushing the deformable joint (4), the lower (5) and upper (6) plates being more rigid than the deformable joint (4 ).
2. Dispositif selon la revendication 1 , caractérisé en ce que les moyens d'actionnement comportent une plaque piézoélectrique (7).2. Device according to claim 1, characterized in that the actuating means comprise a piezoelectric plate (7).
3. Dispositif selon la revendication 2, caractérisé en ce que la plaque supérieure3. Device according to claim 2, characterized in that the upper plate
(6) est constituée par la plaque piézoélectrique (7).(6) is constituted by the piezoelectric plate (7).
4. Dispositif selon la revendication 2, caractérisé en ce que la plaque supérieure4. Device according to claim 2, characterized in that the upper plate
(7) est constituée par une plaque métallique (11) sur laquelle est disposée la plaque piézoélectrique (7).(7) is constituted by a metal plate (11) on which the piezoelectric plate (7) is disposed.
5. Dispositif selon l'une quelconque des revendications 1 à 4, caractérisé en ce que la sortie (3) de liquide est formée dans la plaque inférieure (5).5. Device according to any one of claims 1 to 4, characterized in that the outlet (3) of liquid is formed in the lower plate (5).
6. Dispositif selon l'une quelconque des revendications 1 à 4, caractérisé en ce que la sortie (3) de liquide est constituée par une rainure (16) disposée à l'interface entre le joint deformable (4) et l'une des plaques inférieure (5) et supérieure (6). 6. Device according to any one of claims 1 to 4, characterized in that the outlet (3) of liquid consists of a groove (16) disposed at the interface between the deformable seal (4) and one of lower (5) and upper (6) plates.
7. Dispositif selon l'une quelconque des revendications 1 à 4, caractérisé en ce que la sortie (3) de liquide est constituée par une ouverture (17) formée dans le joint deformable (4).7. Device according to any one of claims 1 to 4, characterized in that the outlet (3) of liquid is constituted by an opening (17) formed in the deformable seal (4).
8. Dispositif selon l'une quelconque des revendications 1 à 7, caractérisé en ce qu'il comporte une bague de serrage (13) disposée sur la plaque supérieure (6) et des moyens de fixation de la bague de serrage (13) et de la plaque inférieure (5).8. Device according to any one of claims 1 to 7, characterized in that it comprises a clamping ring (13) disposed on the upper plate (6) and means for fixing the clamping ring (13) and of the lower plate (5).
9. Dispositif selon l'une quelconque des revendications 1 à 8, caractérisé en ce que le joint deformable (4) est constitué par un joint torique ou par un anneau en elastomère.9. Device according to any one of claims 1 to 8, characterized in that the deformable seal (4) is constituted by an O-ring or by an elastomer ring.
10. Dispositif selon l'une quelconque des revendications 1 à 9, caractérisé en ce qu'au moins une des plaques inférieure (5) et supérieure (6) comporte une gorge (12) dans laquelle est positionné le joint deformable (4). 10. Device according to any one of claims 1 to 9, characterized in that at least one of the lower (5) and upper (6) plates has a groove (12) in which is positioned the deformable seal (4).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR0404114A FR2868966B1 (en) | 2004-04-19 | 2004-04-19 | DEVICE FOR PRODUCING MICRO-DROPS BY EJECTING LIQUID AND METHOD OF MAKING SUCH A DEVICE |
PCT/FR2005/000908 WO2005107946A2 (en) | 2004-04-19 | 2005-04-14 | Device for the production of microdroplets by means of liquid ejection and method of producing one such device |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1765499A2 true EP1765499A2 (en) | 2007-03-28 |
Family
ID=34944551
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP05757262A Withdrawn EP1765499A2 (en) | 2004-04-19 | 2005-04-14 | Device for the production of microdroplets by means of liquid ejection and method of producing one such device |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP1765499A2 (en) |
FR (1) | FR2868966B1 (en) |
WO (1) | WO2005107946A2 (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102004006450B4 (en) | 2004-02-05 | 2012-09-27 | Ing. Erich Pfeiffer Gmbh | metering |
DE102006061506B4 (en) * | 2006-12-15 | 2008-10-30 | Ing. Erich Pfeiffer Gmbh | metering |
FR2963575B1 (en) | 2010-08-09 | 2015-07-17 | Renault Sa | DEVICE FOR EJECTING LIQUID IN THE FORM OF MICROCHARS |
WO2013155513A1 (en) * | 2012-04-13 | 2013-10-17 | President And Fellows Of Harvard College | Devices and methods for in vitro aerosol delivery |
WO2020165617A1 (en) * | 2019-02-15 | 2020-08-20 | Cellsorter Kft. | Piezoelectric micropipette |
CN115007236B (en) * | 2022-06-06 | 2024-03-29 | 湖北大学 | Portable liquid drop manufacturing device based on centrifugal oscillation and liquid drop manufacturing method thereof |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4131899A (en) * | 1977-02-22 | 1978-12-26 | Burroughs Corporation | Droplet generator for an ink jet printer |
JPS58114965A (en) * | 1981-12-28 | 1983-07-08 | Matsushita Electric Ind Co Ltd | Ink jet head |
EP0095911B1 (en) * | 1982-05-28 | 1989-01-18 | Xerox Corporation | Pressure pulse droplet ejector and array |
US5828394A (en) * | 1995-09-20 | 1998-10-27 | The Board Of Trustees Of The Leland Stanford Junior University | Fluid drop ejector and method |
DE19941871A1 (en) * | 1999-09-02 | 2001-04-19 | Hahn Schickard Ges | Apparatus and method for applying a plurality of microdroplets to a substrate |
EP1116590B1 (en) * | 2000-01-11 | 2003-09-17 | Samsung Electronics Co., Ltd. | Ink-jet head device with multi-stacked PZT actuator |
-
2004
- 2004-04-19 FR FR0404114A patent/FR2868966B1/en not_active Expired - Fee Related
-
2005
- 2005-04-14 WO PCT/FR2005/000908 patent/WO2005107946A2/en active Application Filing
- 2005-04-14 EP EP05757262A patent/EP1765499A2/en not_active Withdrawn
Non-Patent Citations (1)
Title |
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See references of WO2005107946A3 * |
Also Published As
Publication number | Publication date |
---|---|
WO2005107946A3 (en) | 2006-02-02 |
FR2868966A1 (en) | 2005-10-21 |
FR2868966B1 (en) | 2007-08-03 |
WO2005107946A2 (en) | 2005-11-17 |
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