WO2003095837A1 - Module de dosage a jet libre et procede permettant de le produire - Google Patents

Module de dosage a jet libre et procede permettant de le produire Download PDF

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Publication number
WO2003095837A1
WO2003095837A1 PCT/EP2003/004754 EP0304754W WO03095837A1 WO 2003095837 A1 WO2003095837 A1 WO 2003095837A1 EP 0304754 W EP0304754 W EP 0304754W WO 03095837 A1 WO03095837 A1 WO 03095837A1
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WO
WIPO (PCT)
Prior art keywords
layer
free jet
chamber
volume
metering
Prior art date
Application number
PCT/EP2003/004754
Other languages
German (de)
English (en)
Inventor
Martin Wackerle
Martin Richter
Original Assignee
Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. filed Critical Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
Priority to DE50303833T priority Critical patent/DE50303833D1/de
Priority to EP03749873A priority patent/EP1488106B1/fr
Publication of WO2003095837A1 publication Critical patent/WO2003095837A1/fr

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Classifications

    • 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
    • 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
    • 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
    • B41J2/17—Ink jet characterised by ink handling
    • B41J2/175—Ink supply systems ; Circuit parts therefor
    • B41J2/17596—Ink pumps, ink valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B43/00—Machines, pumps, or pumping installations having flexible working members
    • F04B43/02—Machines, pumps, or pumping installations having flexible working members having plate-like flexible members, e.g. diaphragms
    • F04B43/04—Pumps having electric drive
    • F04B43/043—Micropumps
    • F04B43/046—Micropumps with piezoelectric drive
    • 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
    • B01L2400/0406—Moving fluids with specific forces or mechanical means specific forces capillary forces
    • 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
    • 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
    • B01L2400/0487—Moving fluids with specific forces or mechanical means specific mechanical means and fluid pressure fluid pressure, pneumatics
    • 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
    • B01L2400/06—Valves, specific forms thereof
    • B01L2400/0605—Valves, specific forms thereof check valves

Definitions

  • Free jet metering module Free jet metering module and method for its production
  • the following invention relates to a free jet metering module and a method for its production, and in particular to such a free jet metering module which is based on the principle of volumetric displacement.
  • the first principle works analogously to the ink jet principle, whereby a piezo actuator or a bubble, which is generated by a heating device, generates a pressure wave in a metering chamber, which propagates to a nozzle which is in fluid communication with the metering chamber and triggers drops there.
  • Free jet metering modules of this type which operate according to the ink jet principle, eject drops in the picoliter range, a typical drop size being 50 picoliters.
  • the repetition frequency with which such a free jet metering module can be operated is a few kHz.
  • Such free jet metering modules working on the ink jet principle are disadvantageous in that the volume of the drop ejected depends on the rheological properties of the liquid, for example the viscosity, the density or the surface tension thereof.
  • metering devices are known from the prior art which operate on the physical principle of volumetric displacement.
  • the metering volume of a metering chamber is displaced volumetrically by a micro actuator via a membrane.
  • the typical volume of a jet ejected by such a displacement is 50 nanoliters.
  • Such a system which is based on volumetric displacement, is disadvantageous in that typical repetition frequencies may not exceed 10 to 20 Hz, since the capillary pressure at the nozzle must not be undercut when suctioning, since otherwise air would be sucked back into the metering chamber.
  • a general disadvantage of all known free jet metering modules is that they are not bubble-tolerant.
  • an air bubble entering the metering chamber of the respective metering module causes the metering module to fail.
  • the metering chamber with the liquid to be metered must therefore always be carried out completely, which is particularly difficult when the metering chamber has corners and the like.
  • air bubbles can get into the dosing chamber by transport, by diffusion through the plastic hose connector, with which the metering module is connected, for example, to a reservoir, or by the outgassing of supersaturated liquids, for example, by temperature changes.
  • a self-priming micromembrane pump that enables the delivery of compressible media is known from DE-A-19719862
  • the object of the present invention is to provide a bubble-tolerant free jet metering module and a method which is suitable for producing such a module.
  • the present invention provides a free jet metering module with the following features:
  • an actuating device adjoining the metering chamber which, when actuated, reduces the metering chamber volume by a displacement volume
  • a nozzle volume being defined by a fluid region existing between the dosing chamber and the ejection opening
  • the ratio of the displacement volume and the sum of the metering chamber volume and the nozzle volume being greater than the ratio of a free jet pressure to the atmospheric pressure in order to generate a free jet at the discharge opening, even if a compressible gaseous medium which essentially filled the metering chamber volume and the nozzle volume were present, the Free jet pressure is the pressure required in the metering chamber which is just sufficient for a given discharge opening area to generate the surface energy in order to cause a free jet at the discharge opening.
  • the present invention also provides a method for producing a free jet metering module, which has the following steps:
  • the present invention is based on the finding that a free jet metering module can work reliably in a bubble-tolerant manner if its compression ratio, ie the ratio of displacement volume and the sum of metering chamber volume and nozzle volume, is chosen to be greater than the ratio of free jet pressure to atmospheric pressure.
  • the free jet metering module according to the invention preferably consists of a metering chamber, a nozzle, a feed line and optionally a reservoir which is connected to the feed line, the module being designed in such a way that the ratio of the displaced volume of the actuating device and the dead volume, which results from the sum of the dead volume of the metering chamber and nozzle chamber is greater than the ratio of the pressure required to form a free jet to the atmospheric pressure.
  • Preferred exemplary embodiments of the free jet metering module according to the invention comprise a valve element between the feed line and metering chamber and / or between the discharge opening of the nozzle and metering chamber.
  • a valve element can be formed by a passive check valve, an active valve or a diffuser nozzle element. If a valve element is provided between the discharge opening of the nozzle and the metering chamber, this must be taken into account when determining the necessary compression ratio of the free jet metering module by making this compression ratio greater than the ratio of the sum of the free jet pressure and the pressure required to open the passive check valve to the atmospheric pressure ,
  • a filter element can be provided in the feed line to the nozzle chamber, a valve element preferably being arranged between the filter element and the nozzle chamber.
  • the method according to the invention is particularly suitable for producing a free jet metering module, the compression ratio of which satisfies the above condition.
  • the method according to the invention manages with a small number of mask steps, at least two, in order to produce the supply line, metering chamber and nozzle structure and passive check valves arranged between the supply line and nozzle chamber and the nozzle structure and metering chamber.
  • a further fourth layer is provided on the first layer, since the first layer must be selectively etched to expose the valve flap structures of the passive check valves.
  • the passive check valves are arranged laterally, ie in the plane of the layer, in the feed line, dosing chamber and nozzle structure be formed, mobile.
  • a fluid filter element can be produced in the feed line at the same time as the structures mentioned.
  • the first mask step serves to generate the respective structures in the second layer, while the second mask step serves to produce depressions in the third layer opposite the movable valve flap structures. No additional mask is required to etch the first layer to selectively etch the valve flaps.
  • La to lc are schematic cross-sectional representations to illustrate the functional principle of a metering module working on the basis of a volumetric displacement
  • FIG. 3 shows a diagram of a pressure applied to the discharge opening of such a metering module
  • Fig. 4 is a schematic cross-sectional view of an embodiment of an inventive
  • FIG. 6 shows a schematic top view of a substrate in which structural elements of an alternative exemplary embodiment of a free-jet metering element according to the invention are formed;
  • FIG. 7a to 7f are schematic cross-sectional representations to illustrate an exemplary embodiment of the method according to the invention.
  • a free jet metering module is shown, which works on the basis of a volumetric displacement.
  • the free jet metering module comprises a reservoir 10, a feed line 12, a metering chamber 14, on which an actuator membrane 16 adjoins on one side, and a nozzle 18 with an ejection opening 20.
  • the free jet metering module is with a liquid to be metered 22 filled.
  • the free jet metering module can be designed such that the feed line, metering chamber and nozzle are filled by capillary forces. Furthermore, filling can be supported by pressurizing the medium located in the reservoir 10, this pressurization, however, must be so small that no liquid can escape from the discharge opening 20, but a liquid meniscus 24 is retained there.
  • the volume of the metering chamber is as a result of a movement of the actuator membrane 16 indicated by dotted lines in Fig. la, changeable.
  • FIG. 1b shows a state of the metering module during an ejection process in which the actuator membrane is actuated by an actuating device (not shown), for example a piezo actuator, such that the volume of the metering chamber 14 is reduced, as indicated by an arrow 26.
  • an actuating device for example a piezo actuator
  • actuation of the actuator membrane 16 also causes a fluid return flow 32, which can be reduced or prevented by suitable measures, for example a higher flow resistance of the feed line 12 compared to the nozzle 18 or the provision of valve elements.
  • FIG. 1c shows a refilling process of the dosing chamber after ejection, as shown in FIG. 1b.
  • the actuator membrane 16 is actuated in a direction 34 opposite to the direction of movement shown in FIG. 1b, so that a media flow 36 takes place into the metering chamber 14.
  • a liquid meniscus 24 regulates itself again at the discharge opening 20 of the nozzle 18.
  • the capillary pressure in the nozzle 18 prevents air from being sucked into the nozzle chamber 14 during the refilling process.
  • this air bubble is compressed during a metering process, as indicated by arrow 26, as indicated in FIG. 2b by the compressed bubble volume 40a compared to the original bubble volume 40b.
  • the pressure at the discharge end 20 of the nozzle 18 drops below the free jet limit.
  • the nozzle is flooded with the medium to be metered, as indicated by the medium 42 in FIG. 2b.
  • the air bubble 40 remains in the metering chamber 14 and essentially assumes its original volume.
  • p d is the pressure prevailing at the discharge opening of the nozzle
  • a d is the discharge opening area
  • ⁇ is the surface tension of the medium
  • U D is the necessary change in area of the surface of the medium to be discharged
  • m is the mass of the free jet ejected
  • v is the velocity is the same.
  • the pressure that is currently required to overcome the surface energy is:
  • the pressure p fre i . which is just sufficient for a given nozzle area to generate the surface energy is referred to below as the "free jet limit". If there is now a gas bubble in the metering chamber, this acts, as explained above, as a damping element for those caused by the actuator element in the metering chamber generated overpressures. This reduces the pressure at the nozzle and drops below the free jet limit.
  • the free jet dosing module according to the invention now enables, during a discharge operation at the ejection port almost re throughout the ejection cycle above the free jet boundary Pf even in the worst case (worst case condition), the pressure p d at the nozzle, that is the same - to maintain.
  • both pressure profiles lie above the free jet limit P fre i essentially during the entire ejection process.
  • it is advantageous to build up the pressure quickly typically on the order of 1 ms.
  • Microactuators in particular those based on piezoelectric or electrostatic, are particularly suitable for this.
  • a fundamental problem with the use of microactuator drive principles is that the stroke of the same is very small.
  • electrostatic diaphragm drive it is of the order of 5 ⁇ m, while piezoelectric diaphragm drives achieve strokes of 30 ⁇ m or more, depending on the diaphragm design. Piezo stack actuators achieve somewhat larger strokes, but are difficult to manufacture.
  • the compression on ratio ⁇ which is defined by the ratio between the metering volume ⁇ V, ie displacement volume of the drive diaphragm, and the dead volume V 0 , is small in the case of free jet metering modules.
  • the dead volume V 0 is composed of the metering chamber volume V k and the nozzle chamber volume V d .
  • the compression ratio ⁇ is defined as:
  • the free jet metering module can then generate a free jet if the pressure p d generated at the discharge opening of the nozzle is greater than the free jet limit Pf re i.
  • the condition for a free jet is therefore:
  • Vgas V n Vw + V ri
  • the damping effect described above is maximum.
  • the actuator membrane compresses this air volume.
  • the maximum pressure at the nozzle is then determined by the pressure in the air bubble.
  • the pressure at the nozzle p d is calculated from the equation of the air bubble:
  • ⁇ A is the adiabatic coefficient of the gas
  • ⁇ V is the change in volume due to the compression of the gas bubble.
  • the compression ratio of bubble-tolerant free jet dispensers must be greater than the ratio of the free jet limit P fre i to atmospheric pressure, ie ⁇ > ----- £ --__
  • the drive is advantageously designed in such a way that the volume can be compressed very quickly, ie microactuators, in particular those based on piezoelectric or electrostatic, are advantageously used.
  • Such actuators must also be suitable for abruptly stopping the volume change, so that the pressure flank drops steeply and the jet breaks off in a defined manner.
  • Such a rapid pressure drop can be achieved by the drive being designed to actively pull back the actuator membrane hen.
  • the metering chamber, actuator membrane and actuating device can be designed in such a way that the actuator membrane is braked abruptly from movement in the ejection phase by hitting a stop.
  • the free jet metering module can be designed such that the actuator membrane strikes the opposite chamber wall or protrusions formed on the same, thereby stopping its movement. If the force with which the membrane is acted upon were sufficient without a stop to deflect it further, the abrupt braking would result in an abrupt drop in pressure and thus a defined break at the discharge opening.
  • a valve element is preferably arranged between a supply line and the metering chamber, which valve element can be, for example, a diffuser nozzle element (diffuser nozzle), a passive check valve or an active valve. Diffuser nozzle element is understood to mean a tapering element which has a preferred direction of flow.
  • valve element between the feed line and the metering chamber ensures that the entire volume to be displaced is expelled by the valve action.
  • Another disadvantage of the feed line being that the flow resistance is too great is that the refilling takes place very slowly, which drastically reduces repetition frequencies.
  • the negative pressure during refilling must not exceed the capillary pressure of the meniscus at the ejection end of the nozzle even during normal operation, ie a complete filling of the pump chamber with a medium to be dosed.
  • Preferred exemplary embodiments of the present invention therefore also include a valve element between the discharge opening of the nozzle and the metering chamber, which in turn can be, for example, a diffuser nozzle element, a passive non-return element or an active valve.
  • Such a valve between the metering chamber and nozzle ejection opening has the advantage in normal operation, ie when the metering chamber is completely filled with liquid, that it is ensured that when the metering chamber is refilled, a significantly higher negative pressure may occur than without this valve.
  • the refilling process is not limited to a maximum repetition frequency of approx. 10 Hz.
  • the suction time is rather independent of the capillary pressure.
  • the valve ensures that the volume displaced by the actuator element only flows in from the reservoir line, whether air or liquid.
  • the dosing chamber would also be filled by capillary forces, but only if the dosing chamber had wetting properties in relation to the medium to be dosed. This is the filling process caused by capillary forces slowly and depending on the rheological properties of the medium to be filled.
  • a free-jet metering device has a structure corresponding to FIGS. 1 and 2 (supply line and reservoir optional), the metering chamber 14 and the nozzle 18 being designed in such a way that the defined ratio of their volumes to the displacement volume is fulfilled.
  • FIG. 4 A schematic cross-sectional view of an embodiment of a free-jet metering module according to the invention provided with check valves is shown in FIG. 4.
  • the free jet metering module is formed by a micromembrane pump 60 and a nozzle chip 62 connected to it.
  • the structure of the micromembrane pump 60 can essentially correspond to the structure of the micromembrane pump described in DE 19719862 A1, but the condition stated with regard to the compression ratio must be observed for use in the free-jet metering module according to the invention.
  • the compression ratio must be at least as large in order to additionally generate the pressure that is necessary to open the valve flap of the passive check valve between the pump and the nozzle.
  • the micro diaphragm pump 60 comprises an actuating device 64, preferably in the form of a piezo actuator.
  • the actuator 64 is attached to a membrane 68 formed in a membrane chip 66.
  • the micromembrane pump 60 further comprises a first valve chip 70 and a second valve chip 72.
  • respective structures are defined, which are at the inlet and provide respective passive check valves 74 and 76 at the outlet of the micro diaphragm pump.
  • the construction and manufacture of such passive check valves can be conventional and therefore requires no further discussion here.
  • a pump chamber 78 of the micromembrane pump which represents the metering chamber according to the invention, is defined by the valve chips 70 and 72 and the membrane chip 66.
  • the nozzle chip 62 is in this way on the micromembrane pump, i.e. attached to the second valve chip 72 thereof, that a nozzle 80 formed therein is connected via the valve element provided to the outlet of the micromembrane pump, which is provided with the check valve 76.
  • a passage opening 82 is provided in the nozzle chip 62, via which the inlet of the micromembrane pump 60, which is provided with the check valve 74, is connected to a feed channel 84, which in turn is fluidly connected to a reservoir 86.
  • the free jet metering module according to the invention is thus formed by a micromembrane pump with a separate nozzle chip, this free jet metering module having a reservoir 86 with a corresponding feed line 84.
  • the structure in which the reservoir and feed line are formed can be produced separately from the free jet metering module, which consists of micropump 60 and metering chip 62, and can then be connected to the same.
  • the free jet limit is determined by the pressure. which is necessary to open the valve 76 provided at the outlet end.
  • This pressure required to open the valve flap is made up of the restoring forces of the valve flap and the forces which have to be applied in order to overcome forces which occur due to a wetting state of the valve opening and which counteract an opening force of the valve flap.
  • the compression ratio is to be chosen larger than the ratio of the sum of the free jet pressure and the pressure required to open the passive check valve to the atmospheric pressure. In order then to provide the expelled free jet 90 with sufficient kinetic energy, the compression ratio can again be chosen to be correspondingly higher.
  • a preferred method for producing a free-jet metering module is described in more detail below with reference to FIGS. 5 to 7.
  • such a method can advantageously be used to generate a free jet metering module with the compression ratios described above.
  • a three-layer structure is used as the starting structure, which has a silicon wafer 92, an oxide layer 94 and a silicon layer 96.
  • SOI Silicon on Insulator
  • BESOI Bonded Etched Back Silicon On Insulator
  • other layer materials can be used, which enable processing through the subsequent steps.
  • Fluid channels, valve flaps, a pump chamber and a nozzle channel are produced in the silicon layer 96 of thickness D in a subsequent anisotropic dry etching, preferably in an etching step.
  • FIG. 5 A schematic view of an exemplary embodiment of the silicon layer 96 after the anisotropic dry etching thereof is shown in FIG. 5.
  • a dosing chamber 100 a Dosierka mereinlledge 102 and a dosing chamber outlet 104 are generated by the anisotropic dry etching.
  • both the inlet 102 and the outlet 104 are provided with a sealing lip in the illustrated embodiment.
  • an inlet valve flap 106 and an outlet valve flap 108 are produced in the silicon layer 96.
  • the valve flap 106 forms an inlet valve together with the inlet 102, while the valve flap 108 forms an outlet valve together with the outlet 104.
  • a nozzle chamber 110 and a feed line 112 are also produced in the silicon layer 96.
  • the feed line comprises a widened area 114, in which projections 116 remain, so that this area acts as a fluid filter.
  • predetermined breaking points 120, 122 are also provided in the silicon layer 96 during the anisotropic dry etching, along which breakage can later take place, on the one hand to expose the feed line 112 and on the other hand a discharge opening 124 of the nozzle, i.e. to realize the nozzle chamber 110.
  • FIG. 7b An alternative structuring of the silicon layer 96 during the anisotropic dry etching (FIG. 7b) is shown in FIG. 6. Structures in the exemplary embodiment shown there, which essentially correspond to those of FIG. 5, are identified by the same reference numerals. In the exemplary embodiment shown in FIG. 6, no fluid filter is provided in the feed line 112. In the example shown in FIG. 6, projections 126 are provided in the wall of the nozzle chamber 110 opposite the outlet valve flap 108, which serve to prevent the valve flap 108 from adhering to this wall in the open state.
  • valve flaps are selectively etched free, preferably HF etching, so that the oxide layer in the region below the valve flaps 106 and 108 (FIG. 5) is removed so that the latter is in the plane of the silicon layer 96 are laterally movable.
  • the width of the valve flaps 106 and 108 is designed to enable the etching of the oxide layer 94 by HF etching. Typical suitable widths of the valve flaps can be in a range from 5 to 30 ⁇ m.
  • a silicon layer 130 is shown, in which recesses or depressions 132 are formed opposite the valve flaps 106 and 108 by anisotropic dry etching, in order to prevent the valve flaps from being firmly bonded when the silicon layer 130 is subsequently connected to the silicon layer 96, so that the valve flaps remain movable.
  • the recesses can have a depth of 1 to 3 ⁇ m, for example.
  • the respective fluid passages 102 and 104 through the valve flaps 106 and 108 are not completely closed due to the undercut of the valve flaps and the creation of the recesses 132. can be sen. Due to the depth of the non-closable sections of the order of magnitude of 1 to 3 ⁇ m, however, they have such a high flow resistance that flow through them is negligible, so that the respective fluid passages can be regarded as essentially closable by the valve flaps.
  • the layers 96 and 130 are preferably connected by conventional wafer bonding using OH groups.
  • a thin oxide layer is produced to support at least one of the layers, but this is not a joining layer in the classic sense, so that wafer bonding can be described as having no joining layer.
  • FIG. 7d The resulting structure after this step of connecting is shown in FIG. 7d, wherein it can be seen that the metering chamber 100 is formed by the step of connecting.
  • Figures 7a to 7f are purely schematic, so that the valve structures produced are only shown as undercut sections 134 and 136 in them.
  • a passivation layer 138 is applied to the upper side of the wafer 92, whereupon the silicon layer 130 is thinned from the exposed rear side thereof in order to produce the silicon actuator membrane 140 for the free-jet metering module, as shown in FIG. 7e ,
  • the layer 130 can, for example, be subjected to a full-area KOH thinning or a whole-area thinning by grinding. Alternatively, a structured fertilizer only the areas of the layer 130 that are to serve as an actuator membrane. As an alternative to the process-related treatment of the layer 130 to produce the membrane after the application thereof, the layer 130 can already be applied with a thickness which, at least in the actuator membrane regions, corresponds to the desired membrane thickness.
  • a drive device is subsequently applied to the silicon actuator membrane 140.
  • a metallization layer 142 is first applied to the exposed surface of the layer 130 and subsequently a piezoceramic 144 is applied, preferably glued, to the metallization layer 142.
  • a piezostack can be brought into contact with the actuator membrane in such a way that the actuator membrane can be actuated by the same.
  • the use of a piezo stack enables greater forces and larger strokes, but is more complex than a glued-on piezo ceramic.
  • the use of a piezo stack is thus particularly suitable for a modular construction in which the actuating device is not permanently connected to the rest of the free jet metering module and is therefore reusable.
  • the discharge opening of the nozzle chamber 110 and an inlet opening of the feed line 112 are opened by breaking along the predetermined breaking points 120 and 122. Breaking is advantageous in that it is done dry. Alternatively, the above openings could be sawn the layer structure are generated, with the risk that the openings are contaminated by saw water and saw dust used. Another method for separating or creating the openings is to carry out laser cutting, which is also a dry method and also provides defined nozzle areas. Furthermore, it is not necessary to create the openings laterally. Rather, the inlet inlet opening and / or the discharge opening could be formed by layers 130 and 142 downwards and / or by layers 92 and 138 upwards.
  • the method described above is particularly suitable for producing a free jet metering module, the compression ratio of which fulfills the condition described above.
  • anisotropic dry etching is used instead of a KOH structuring for the etching steps mentioned.
  • the anisotropic dry etching enables a small dead volume in the dosing chamber using only a single process step. Any channel and chamber geometries can also be implemented.
  • only two masks are required in order to generate the free jet metering module when using an anisotropic dry etching by the described method.
  • the anisotropic dry etching further enables the integration of a fluid filter in the feed line. In addition, this enables a small dead volume in the valve area.
  • connectionless connection of the two wafers described above they can also be connected to one another using a connection layer.
  • the connecting layer has recesses in the region of the valve flap structures, so that these valve flaps in turn remain movable in the plane of the layer in which they are formed.
  • the present invention thus provides a method for producing a fluid module which has a layer in which a fluid chamber with an inlet and / or outlet is structured, and in which one or more valve flaps are also provided for the inlet and / or outlet which are movable in the plane of the layer to close the inlet and / or outlet.
  • the method according to the invention thus deviates from known methods in which valve flap structures were each movable perpendicular to the plane of the layer in which they are formed.
  • the production and arrangement of valve flaps according to the invention advantageously enables the production of free jet metering modules which have a high compression ratio with very few mask processes.
  • other technologies for example injection molding technology or precision machining processes, can also be used to produce the free jet metering module according to the invention.
  • the free jet metering module takes place on the basis of fast, time-dependent processes in the metering chamber and the nozzle chamber.
  • the real pressure available at the discharge opening of the nozzle depends on the friction and the inertia of the medium to be dosed in the nozzle chamber and dosing chamber. More specifically, there is a pressure drop between the point at which the actuator membrane generates the pressure and the discharge opening, where the pressure available at the discharge opening is lower by this pressure drop than the pressure generated by the actuator membrane. This pressure drop must be taken into account when setting the compression ratio.
  • the free jet metering module according to the invention is therefore advantageously designed so that this pressure drop is as low as possible and is therefore negligible.
  • the friction mentioned above depends on the third power of the dosing chamber height. In order to minimize friction losses, it would therefore be advantageous to provide the metering chamber with the greatest possible height.
  • the actuator membrane in order to be able to pay for the necessary compression ratio, it must be ensured that the actuator membrane can displace a large part of the metering chamber volume or the entire metering chamber volume.
  • the actuator consisting of the membrane and the actuating device must be designed accordingly.
  • the shape of the metering chamber can be such that it is adapted to the shape of the actuator membrane in the deflected state.
  • the metering chamber height of the free jet metering module described with reference to FIGS. 5 to 7 is therefore set, for example, to be greater than 10 ⁇ m, preferably greater than 20 ⁇ m or 30 ⁇ m.
  • the drive must be selected so that the necessary compression ratio can still be generated, so that the metering chamber height cannot be as large as desired.
  • the thicknesses of the layers 96 and 94 can thus preferably be chosen such that the metering chamber has a height corresponding to the above statements.
  • a silicon layer 96 with a thickness of more than 10 ⁇ m and more preferably a silicon layer 96 with a thickness of more than 10 ⁇ m and less than 50 ⁇ m can therefore be used in the described method.
  • a dosing chamber height as described above leads to an increased ejected dosing volume.
  • the pressure drop described above is kept low by arranging the nozzle with its ejection opening essentially in the center opposite the actuator membrane.
  • the nozzle could be arranged centrally below the actuator membrane.
  • such an arrangement is also possible without a valve between the metering chamber and nozzle, i.e. Ejection opening of the same possible.
  • the friction losses and inertia losses described above are essentially minimized, and the discharge of small metering volumes is possible.
  • the free jet metering module according to the invention is designed to remain operable even when it is completely filled with a compressible gaseous medium
  • the free jet metering module according to the invention is also suitable for conveying or metering gaseous media.
  • a free jet metering module with a single metering chamber and a single nozzle chamber was described above.
  • a free jet metering module according to the invention can moreover have a plurality of metering chambers and associated nozzles which are arranged in a one-dimensional or two-dimensional array, so that the nozzles have a predetermined positional relationship to one another.
  • Such a module with an array of individual ejection devices can easily be produced by producing a plurality of ejection devices at the wafer level at the same time.
  • the method described with reference to FIGS. 5 to 7 can be used to produce a plurality of ejection devices arranged in a row, the inlet openings and ejection openings of which are then opened together.
  • two-dimensional arrays can be produced, in which case inlet openings and discharge openings are preferably led out upwards and / or downwards.

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  • Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Clinical Laboratory Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)

Abstract

L'invention concerne un module de dosage à jet libre comprenant une chambre de dosage (78) avec un volume de chambre de dosage, un dispositif d'actionnement (64, 68) jouxtant la chambre de dosage (7), qui lorsqu'il est actionné, réduit le volume de la chambre de dosage d'un volume de déplacement, ainsi qu'une ouverture d'éjection (80) reliée par voie fluidique à la chambre de dosage (78). Un volume d'ajutage est défini par une zone fluidique existant entre la chambre de dosage (78) et l'ouverture d'éjection (80). Le rapport issu des volumes de déplacement et de la somme des volumes de chambre de dosage et des volumes d'ajutage est supérieur au rapport d'une pression de jet libre à la pression atmosphérique, afin de produire un jet libre, y compris en présence d'un milieu gazeux compressible remplissant sensiblement le volume de la chambre de dosage et le volume d'ajutage. A cet effet, la pression du jet libre est la pression requise dans la chambre de dosage, qui suffit amplement pour la surface d'ouverture d'éjection donnée, pour produire l'énergie superficielle requise pour induire un jet libre au niveau de l'ouverture d'éjection.
PCT/EP2003/004754 2002-05-07 2003-05-06 Module de dosage a jet libre et procede permettant de le produire WO2003095837A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE50303833T DE50303833D1 (de) 2002-05-07 2003-05-06 Freistrahldosiermodul und verfahren zu seiner herstellung
EP03749873A EP1488106B1 (fr) 2002-05-07 2003-05-06 Module de dosage a jet libre et procede permettant de le produire

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE10220371.7 2002-05-07
DE10220371A DE10220371A1 (de) 2002-05-07 2002-05-07 Freistrahldosiermodul und Verfahren zu seiner Herstellung

Publications (1)

Publication Number Publication Date
WO2003095837A1 true WO2003095837A1 (fr) 2003-11-20

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Country Status (3)

Country Link
EP (1) EP1488106B1 (fr)
DE (2) DE10220371A1 (fr)
WO (1) WO2003095837A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8845307B2 (en) 2010-05-25 2014-09-30 Samsung Electro-Mechanics Co., Ltd. Micro-ejector and method for manufacturing the same
DE102015224619A1 (de) 2015-12-08 2017-06-08 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Mikrodosiersystem
DE102015224622A1 (de) 2015-12-08 2017-06-08 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Freistrahldosiersystem
US11399978B2 (en) 2015-12-08 2022-08-02 Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V. Free jet dosage system for the eye

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007015726B4 (de) 2007-04-02 2011-09-29 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Auslenkbare Struktur, mikromechanische Struktur mit derselben und Verfahren zur Einstellung einer mikromechanischen Struktur
EP3450020B1 (fr) 2017-09-01 2021-04-07 Eppendorf AG Dispositif de microdosage permettant le dosage de plus petits échantillons de fluide
EP3485974B2 (fr) 2017-11-17 2024-07-10 Eppendorf SE Dispositif de microdosage permettant le dosage de plus petits échantillons de fluide

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DE19737173A1 (de) * 1997-08-26 1999-03-18 Eppendorf Geraetebau Netheler Mikrodosiersystem
US6033191A (en) * 1997-05-16 2000-03-07 Institut Fur Mikrotechnik Mainz Gmbh Micromembrane pump
US6280148B1 (en) * 1997-02-19 2001-08-28 Hahn-Schickard-Gesellschaft Fur Angewandte Forschung Microdosing device and method for operating same
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EP2309130B1 (fr) * 1999-06-28 2016-08-10 California Institute of Technology Obturateur élastomère micro-usiné et systèmes de pompe
JP4342749B2 (ja) * 2000-08-04 2009-10-14 株式会社リコー 液滴吐出ヘッド、インクカートリッジ及びインクジェット記録装置

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US5593290A (en) * 1994-12-22 1997-01-14 Eastman Kodak Company Micro dispensing positive displacement pump
US6280148B1 (en) * 1997-02-19 2001-08-28 Hahn-Schickard-Gesellschaft Fur Angewandte Forschung Microdosing device and method for operating same
DE19719862A1 (de) * 1997-05-12 1998-11-19 Fraunhofer Ges Forschung Mikromembranpumpe
US6033191A (en) * 1997-05-16 2000-03-07 Institut Fur Mikrotechnik Mainz Gmbh Micromembrane pump
DE19737173A1 (de) * 1997-08-26 1999-03-18 Eppendorf Geraetebau Netheler Mikrodosiersystem
US20020012614A1 (en) * 1998-03-04 2002-01-31 Akira Koide Liquid feed apparatus and automatic analyzing apparatus

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8845307B2 (en) 2010-05-25 2014-09-30 Samsung Electro-Mechanics Co., Ltd. Micro-ejector and method for manufacturing the same
DE102015224619A1 (de) 2015-12-08 2017-06-08 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Mikrodosiersystem
DE102015224622A1 (de) 2015-12-08 2017-06-08 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Freistrahldosiersystem
US10550833B2 (en) 2015-12-08 2020-02-04 Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V. Microdosing system
US11022470B2 (en) 2015-12-08 2021-06-01 Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V. Free-jet dosing system
US11399978B2 (en) 2015-12-08 2022-08-02 Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V. Free jet dosage system for the eye

Also Published As

Publication number Publication date
EP1488106B1 (fr) 2006-06-14
DE50303833D1 (de) 2006-07-27
EP1488106A1 (fr) 2004-12-22
DE10220371A1 (de) 2003-11-27

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