aerosol generator

Abstract

To provide an aerosol generation device with a micro pump.SOLUTION: An aerosol generation device includes a cartridge, an atomizer, and a micro pump 1 for delivering fluid. The micro pump is provided with two pump chambers which are disposed between the cartridge and the atomizer and have two separate chamber capacities and two actuators 6 for supplying the atomizer with an aerosol-forming substrate from the cartridge. Each of the actuators is allocated to one of the two pump chambers 2 to change each chamber capacity. The two pump chambers are arranged in parallel and are in fluid communication with a common inlet and a common outlet 5. The actuator is configured to operate in parallel so that a change of volume in the two respective pump chambers simultaneously occurs to both pump chambers.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an aerosol generating device, and more particularly to an aerosol generating device including a micropump. [Background technology]

[0002] In aerosol generating devices, liquid is vaporized or atomized in an atomizer (e.g., a heating element) located adjacent to the opening of a cartridge containing the liquid. Typically, the liquid is transported to the atomizer by capillary action in a capillary material. However, in such systems, the liquid is limited to a short distance, limiting the placement of the cartridge and atomizer.

[0003] There is a need for an aerosol generating device that offers greater versatility in the placement of the reservoir for the aerosol-forming substrate and the atomizer for atomizing the aerosol-forming substrate, and there is also a need for a device that provides adequate performance, especially with viscous aerosol-forming fluids. Summary of the Invention

[0004] According to the present invention, an aerosol generating device is provided. The device includes a cartridge for holding an aerosol-forming substrate and an atomizer for atomizing the aerosol-forming substrate. The device further includes a micropump for delivering a fluid, wherein the micropump is disposed between the cartridge and the atomizer and is fluidly connected to the cartridge and the atomizer for supplying the aerosol-forming substrate from the cartridge to the atomizer. The micropump includes two pump chambers having two separate chamber volumes and two actuators, each actuator assigned to one of the two pump chambers for changing the respective chamber volume. Each pump chamber is provided with at least one inlet valve and at least one outlet valve for establishing a pumping direction. The micropump further includes a common inlet and a common outlet. The two pump chambers are arranged in parallel and fluidly connected to the common inlet and common outlet, and the actuators are configured to operate in parallel so that volume changes in each of the two pump chambers occur simultaneously in both pump chambers. For example, a control electronic circuit within the aerosol generating device can control the micropumps or the actuators of the micropumps, respectively.

[0005] By operating the actuators simultaneously and preferably having the same volume change with the actuator stroke, the pumping pressure can essentially be doubled compared to having only one pumping chamber. The pumping pressure can also be doubled compared to, for example, two pumps connected in series. Such single or series micropumps are known, for example, from Bartels Mikrotechnik GmbH, such as the Bartels mp5 micropump with one actuator and the Bartels mp6 micropump with two actuators in two series-arranged pumping chambers.

[0006] The parallel arrangement of two pump chambers also allows the micropump to provide high performance and high flow rates even for viscous liquids. Since the maximum flow rate generally decreases with more viscous fluids, two pump chambers at higher pumping pressures allow for significantly higher flow rates even for viscous or highly viscous fluids.

[0007] The parallel arrangement of the two pump chambers also facilitates the compact and miniaturized design of the micropump and the aerosol generating device in which the micropump is used. This is particularly suitable for handheld devices where space is limited and the device should be miniaturized. Such handheld devices can be, for example, medical inhalers, or vaping or smoking devices. Such handheld devices can also be, for example, vaping devices, where e-liquid is vaporized, and such e-liquid is generally a viscous fluid.

[0008] The actuator of the micropump may be driven by control electronics connected to the micropump, which may be combined with the control electronics of the aerosol generating device for controlling the device.

[0009] The actuator may be a piezoelectric membrane actuator, a mechanical actuator, a thermal actuator, a magnetic actuator or any other suitable actuator that brings about a volume change in the pump chamber. Preferably, a disk-shaped or plate-shaped actuator is used. Preferably, in the device according to the invention, two piezoelectric membrane actuators are used in the micropump.

[0010] In a piezoelectric membrane actuator, the amplitude of the voltage applied to the actuator determines the stroke of the actuator and therefore the displacement of the pumped medium per pump cycle. Increasing the amplitude of the controller voltage increases the flow rate linearly to a maximum flow rate.

[0011] The flow rate also increases linearly within a defined frequency range. The frequency determines the number of strokes the pump makes per unit time. After reaching a maximum flow rate at the resonant frequency, the flow rate decreases again as the frequency increases above resonance.

[0012] The combination of signal, amplitude and frequency defines the performance of the micropump, so the operating parameters can be adapted according to the fluid being moved by the micropump.

[0013] Each pump chamber of the micropump has at least one inlet valve and at least one outlet valve. Preferably, each pump chamber has two inlet valves and two outlet valves. Two valves per pump chamber have been shown to provide reliable micropump operation.

[0014] In operation, fluid flows along the fluid path from a common inlet to a common outlet, through each of the two pump chambers, and via the respective inlet and outlet valves. That is, a fluid path can be defined as the path or trajectory a fluid follows as it is moved within the micropump. Valves are preferably positioned and designed in such a way that valve-induced changes in the direction of the fluid stream along the fluid path are minimized. Thus, the energy required to move the fluid is minimized and, additionally, air bubble accumulation is reduced. Furthermore, a smoother fluid path reduces turbulence and the amount of fluid impingement on the micropump walls, thereby helping to reduce the amount of mechanical vibration and noise experienced by the user. Angular changes in the fluid path are preferably not abrupt. Preferably, the fluid path does not have angles less than 90 degrees. For example, the design of the pump chambers and their respective valves ensures that fluid flows through the valves at obtuse angles. Advantageously, the direction of fluid flow along the fluid path from the common inlet to the common outlet does not change by more than 90 degrees. Additionally, the holes in the micropump device elements that connect different fluid surfaces preferably have a diameter equal to or greater than the length of the hole.

[0015] Advantageously, the two pump chambers are directly fluidly connected to a common inlet and a common outlet, and thus each pump chamber is directly connected to the common inlet and the common outlet without an intermediate fluid channel, and thus advantageously the fluid connections of the pump chambers and the common inlet or common outlet are only separated by at least one inlet valve or at least one outlet valve of the pump chambers, respectively.

[0016] In the device, the two actuators as well as the two pump chambers can be arranged opposite each other. Preferably, the two actuators and the two pump chambers are arranged diametrically opposite each other. Such an arrangement facilitates the manufacture of the micropump and allows for the manufacture of a very compact micropump.

[0017] The two pump chambers and the two actuators may be configured such that the same volume change occurs in each of the two pump chambers upon actuation of the two actuators.

[0018] The chamber volumes of the two pump chambers do not have to have the same size and may be different, however it is preferred that the volumes of the two pump chambers are the same.

[0019] In a preferred embodiment, the components, particularly the valves and actuators, required for the manufacture of one pump chamber of a micropump are designed to be substantially interchangeable or identical to the components of a second pump chamber of the same micropump. That is, all actuators, valves, and optionally other components within each pump chamber are preferably designed to be identical. This reduces the risk of mix-up during assembly and minimizes manufacturing costs.

[0020] The micropump preferably comprises a symmetrical setup as viewed from a plane parallel to and located between the two pump chambers.

[0021] The symmetrical and in particular identical set-up of the two pump chambers allows for a simplification of the control and operation of the micropump.

[0022] This symmetrical setup may include a common inlet and a common outlet. Thus, the inlet connection of the common inlet may be located on one side of the micropump, and the outlet connection of the common outlet may be located on the opposite side of the micropump. However, the inlet connection of the common inlet and the outlet connection of the common outlet may also be located on the same side of the micropump. This allows for the production of an even more compact micropump.

[0023] All components in contact with the fluid are preferably made of the same material. The pump chamber, valves, and common inlet and outlet ports are preferably manufactured from the same material. Such materials can be adapted to the physical and chemical properties of the fluid to be pumped. For example, all components in contact with the fluid can be made of polyphenylene sulfone (PPSU). This material preferably offers advantages with regard to the bonding and assembly techniques used to bond the micropump in the device according to the present invention. However, other suitable materials, such as polypropylene (PP) or polyimide (PI), can also be used. For example, in the medical field, it may be necessary to coat parts in contact with the fluid with, for example, a biocompatible or other particularly inert material to adapt the device to specific requirements. Other materials, such as silicon, metal, or glass, can also be used, although in the case of materials with low elasticity, it must be ensured that the actuator can still cause a change in the chamber volume.

[0024] All components of the micropump that must be joined together can be joined, for example, by suitable adhesives or preferably using laser welding, the latter technique being particularly suitable for joining plastics and offering the possibility of producing, without adhesives, a sealed connection approaching the strength of the raw materials, in addition to short manufacturing times.

[0025] In one preferred embodiment, the micropump comprises the following elements, essentially in the order corresponding to the assembly order: - two base elements each containing a recess and an inlet half and an outlet half; - two actuators each having an electrode and an electrical terminal, each actuator being positioned in one of the recesses; two protective layers arranged to cover each actuator formed on one side of each pump chamber; a valve foil that can be inserted into the recess and that carries the movable parts of the inlet and outlet valves of the pump chamber; two intermediate layers, also insertable into the recesses and having openings which form the stationary parts of the inlet and outlet valves, which together with the respective protective layers and the recess side walls form the pump chambers;

[0026] The actuator and protective foils as well as the valve foil and intermediate foil may be held in place by seals, for example by welded or adhesive seals.

[0027] Once the flow separation element is positioned between the inlet and outlet and between the two base elements, the two base elements may be assembled together. The two base elements are preferably fluid-tight sealed (preferably laser welded), and the recesses in the two base elements are preferably closed in such a way that the components inside the base elements are protected from environmental influences. When assembled, the two halves of the inlet and outlet also combine to form a common inlet and common outlet, as well as corresponding inlet and outlet connections. These allow the micropump to be connected to a reservoir and atomizer, or to corresponding tubing connected to the reservoir and atomizer, respectively.

[0028] The aerosol generating device may further comprise a flow sensor for controlling the fluid flow at the common outlet of the micropumps. The flow sensor is connected to a control electronic circuit. This allows the fluid flow to be controlled, e.g., kept constant, e.g., by changing the micropump parameters as needed. The device may thus comprise a controlled loop system.

[0029] The atomizer of the device may be designed to atomize or vaporize the aerosol-forming substrate by any suitable means. For example, the atomizer may vaporize the substrate by heat, or may atomize or atomize the substrate by ultrasonic or other vibrational means. The atomizer of the device according to the invention may comprise any one or combination of an acoustic atomizing element, an ultrasonic vibration device, a vaporizer (such as a heater), or any other atomizer suitable for atomizing the aerosol-forming substrate.

[0030] The device may contain any fluid to be atomized. The fluid may be a gas or a liquid or a combination thereof. Preferably, the aerosol-generating substrate is a liquid. However, the aerosol-generating substrate may also be originally a solid that is liquefied, for example by heating, so that the liquid can be moved to the atomizer by a micropump.

[0031] The aerosol-forming substrate may comprise, for example, a medicinal, flavoring, or stimulating substance.

[0032] The liquid aerosol-forming substrate may comprise at least one aerosol former and a liquid additive.

[0033] The aerosol former may be, for example, propylene glycol or glycerol.

[0034] The liquid aerosol-forming substrate may comprise water.

[0035] The aerosol-forming substrate is preferably an e-liquid used in a vaping system.

[0036] In such systems, the liquid additive may be any one or any combination of liquid flavors or liquid stimulants. Liquid flavors may include, for example, tobacco flavors, tobacco extracts, fruit flavors, or coffee flavors. The liquid additive may be, for example, a sweet liquid (e.g., vanilla, caramel, and cocoa), an herbal liquid, a spicy liquid, or a stimulant liquid (e.g., a liquid containing caffeine, taurine, nicotine, or other stimulants well known in the food industry).

[0037] The device preferably comprises one or a combination of a nicotine-containing aerosol-forming substrate and a tobacco-flavour-containing aerosol-forming substrate.

[0038] Preferably, the device according to the invention comprises a viscous liquid aerosol-forming substrate having a viscosity of from 1 mPas to 200 mPas, preferably from 1 mPas to 150 mPas, for example from 80 mPas to 130 mPas.

[0039] Preferably, the aerosol generating device is an electronic smoking device for use in an electronic smoking system, which may be a handheld device, or a smoking system in which tobacco is heated rather than combusted.

[0040] Exemplary values ​​for a micropump preferably used in a device according to the invention are as follows: -Chamber volume 1ml~2ml, -flow rates of 1 μL / S and 7 μL / S; -Pumping pressure 500mBar~700mBar, - Micro pump size (without connector) approx. 14 x 14 x 6.5mm 3 ,

[0041] Exemplary operating parameters for the micropump are as follows: - Frequency: 0-300Hz - Voltage, up to 320Vpp - Sine, rectangular or intermediate shaped actuator voltage curve. Preferably, the rising and falling phases of the actuator are not identical. The actuator voltage curve is preferably adapted to optimize the micropump, taking into account noise and bubble generation, at a given flow rate and viscosity of the fluid.

[0042] The invention will be further described with reference to embodiments, which are illustrated by the following drawings, in which: [Brief explanation of the drawings]

[0043] [Figure 1] FIG. 1 is an exploded view of a micropump setup with two serially arranged actuators, showing exemplary components of the micropump. [Figure 2] FIG. 2 shows a micropump with parallel actuators. DETAILED DESCRIPTION OF THE INVENTION

[0044] Figure 1 shows an exploded view of the Bartels mp6 micropump described in US Patent Application No. US 2011 / 0005606. The micropump 1' consists of a layered assembly with two serially arranged pump chambers 2. In Figure 1, the assembly 1' is specifically comprised of the following components: a base element 7, a valve foil 8, an intermediate layer 9, a protective layer 10, two actuators 6, and a lid element 11.

[0045] A particularly preferred base element 7 is made of plastic. It includes recesses 7' into which all subsequent components are inserted or placed. The base element also includes an inlet 4 and an outlet 5, which are provided for fluid delivery and, as illustrated here, are designed, for example, as hose-like connectors. Other connector types adapted to the respective application are also possible. The base element 7 also includes components of the fluid channels required for the valves 3, which are preferably manufactured by injection molding and therefore in the same process as the base element itself. Furthermore, the base element 7 has protruding parts 7'' that are identical to the mounting aids in the form of geometric features arranged in a manner that interlocks with the recesses of the mounting aids 7'''. Thus, assembly of subsequent components, such as the valve foils 8, can only occur in a certain orientation, which largely eliminates incorrect mounting.

[0046] The valve foil 8 comprises the movable parts of the valves 3. The valve foil 8 is inserted into the base element 7. In the illustrated embodiment, the valve foil 8 comprises the movable parts of the inlet valve 3' of each pump chamber and the movable parts of the respective outlet valve 3''. Furthermore, the valve foil also comprises recesses for mounting aids 7''' which serve to insert the valve foil intact.

[0047] The intermediate layer 9 is preferably made of plastic and is designed to be able to be inserted into the recesses 7' of the base element 7. In the center of each pump chamber 2 formed by a recess in the intermediate layer, one opening 9' is located in each case so that fluid can flow into or out of the respective pump chamber.

[0048] A protective layer 10 is applied to the intermediate layer, and is therefore in fluid contact with the upper pump chamber. The protective layer must therefore be tightly connected to the intermediate layer 9 to prevent fluid from leaking or spilling into the surrounding area or into the area between the pump chambers. Therefore, through-hole laser welding is preferably used. Alternative manufacturing techniques include gluing, ultrasonic welding, or mechanical clamping of the respective components.

[0049] The two actuators 6 are provided as disk-shaped piezoelectric actuators in the illustrated embodiment. Each actuator is geometrically adapted to the pump chamber 2 located below and has a corresponding electrode 6' for electrical contact. Connected to these are electrical terminals 6'' which can be led out of the housing of the assembly 1' and which provide a sufficient number of individual wires to connect each actuator 6.

[0050] The lid element 11 serves as a seal for the housing of the device, which housing essentially consists of the base element 7. The lid element is also preferably manufactured from plastic and is designed so that it can be connected to the base element 7 by through-hole laser welding.

[0051] 2 shows a micropump 1 with two actuators 6 arranged in parallel. The micropump is also a layered assembly, where the basic elements of one pump chamber may be similar to the individual pump chambers and actuators described in relation to FIG.

[0052] In Figure 2, two base elements 7 each include a recess into which all components forming one pump chamber are inserted or placed. The two base elements 7 also preferably include half of an inlet 40 and half of an outlet 50, which when the two base elements 7 are assembled form a common inlet 4 and a common outlet 5, as shown in Figure 2. The inlet 4 and outlet 5 can be connected to tubing 44, 55 (e.g., plastic hoses) for delivering fluid to and from the micropump 1.

[0053] The two actuators 6 are provided in the illustrated embodiment as disk-shaped piezoelectric actuators, one each inserted into a recess in a respective base element 7. The piezoelectric actuators may be, for example, a piezoelectric ceramic attached to a brass membrane, which deforms the membrane when a voltage is applied.

[0054] Each actuator 6 is geometrically adapted to the size of its recess, which essentially defines a lateral extension of the underlying pump chamber 2. Each actuator 6 is connected to an electrode and is provided with wires 60 for electrical contact with the actuator. The wires 60 lead out from the housing of the micropump 1.

[0055] A protective layer 10 (e.g., Kapton tape) is provided within the recess and forms one side of the pump chamber 2. The protective layer 10 transmits the movement of the piezoelectric actuator to the pump chamber 2. The protective layer 10 is held in place by a seal 95 (e.g., a weld seal, clamping or adhesive seal) and also seals the pump chamber 2.

[0056] An intermediate layer 90, preferably made of plastic, is inserted into each recess of the base element 7. The intermediate layer 90 carries a valve foil and is held in place by another seal 95 (e.g., a welded seal) and seals the pump chamber 2. The gap between the intermediate layer 90 and the protective layer 10 and the walls of the recess define the size of the pump chamber 2.

[0057] The inlet openings 91 are located off-center in the intermediate layer 90 in the direction of the inlets 4, through which fluid can flow from the common inlet 4 to the respective pump chambers 2. The outlet openings 92 are located off-center in the intermediate layer 90 in the direction of the outlets 5, through which fluid can flow from the respective pump chambers 2 to the common outlet 5. In the center of the intermediate layer 90, a flow separation element 98 is arranged.

[0058] One flow separation element 98 is used for both pump chambers and is positioned between the two pump chambers to separate the common inlet 4 from the common outlet 5 in the direction of flow. The flow of fluid 100 from the common inlet 4 toward the common outlet 5 defines a fluid path, as shown by the arrows in Figure 2. The fluid path is shown to include no angles less than 90 degrees, i.e., the flow path includes only obtuse angles, because the flow separation element 98 has a shape and structure that supports smooth fluid flow from the common inlet 4 through the inlet valve 30 and from the outlet valve 31 into the common outlet 5.

[0059] The first valve foil 80 comprises the movable part of the inlet valve or valves 30 of each pump chamber. The second valve foil 81 comprises the movable part of the respective outlet valve 31. The first valve foil 80 may be attached to the intermediate layer 90. The second valve foil 81 may be attached to the flow separation element 98.

[0060] By activating the piezoelectric actuators 6 in parallel and simultaneously, their deformation causes the protective foil 10 to move backward. Under the pressure generated, the inlet valves 30 open, allowing a flow of fluid 100 into each pump chamber 2 from the common inlet 4. Activation of the piezoelectric actuators in the opposite direction compresses the pump chambers 2 due to the flexibility of the protective layer 10, forcing the fluid from the pump chambers 2 through the now-open outlet valves 31 and out of the pump chambers 2 to the common outlet 5. Due to the valve arrangement, the inlet valves 30 automatically close when the outlet valves 31 open, and vice versa.

[0061] The pump chambers 2 preferably have the same chamber volume and the same geometric shape. The micropump 1 of Figure 1 is symmetrical about an imaginary central plane disposed between and parallel to the two actuators 6 and extending through a common inlet and a common outlet. Such a structure makes it possible to manufacture the micropump with only a small number of parts, preferably two identical individual micropump halves with one base element and pump chambers.

Claims

1. An aerosol generating device, comprising: a cartridge for holding an aerosol-forming substrate; an atomizer for atomizing the aerosol-forming substrate; a micropump (1) for delivering a fluid, said micropump (1) being arranged between said cartridge and said atomizer and in fluid connection with said cartridge and said atomizer for supplying an aerosol-forming substrate from said cartridge to said atomizer, said micropump (1) Two pump chambers (2) with two separate chamber volumes; two actuators (6), each assigned to one of the two pump chambers (2) for varying the respective chamber volume; At least one inlet valve (30) and at least one outlet valve (31) are provided in each pump chamber (2) to establish the pumping direction; a common inlet (4) and a common outlet (5), the two pump chambers (2) are arranged in parallel and are fluidly connected to the common inlet (4) and the common outlet (5); the inlet connection of the common inlet (4) is located on one side of the micropump (1) and the outlet connection of the common outlet (5) is located on the opposite side of the micropump (1), The device wherein the actuators (6) are configured to operate in parallel such that a volume change in each of the two pump chambers (2) occurs simultaneously in both pump chambers (2).

2. 2. The device according to claim 1, wherein the two pump chambers (2) are in direct fluid communication with the common inlet (4) and the common outlet (5).

3. 3. The device according to any one of claims 1 to 2, wherein the two pump chambers (2) and the two actuators (6) are arranged opposite each other.

4. 4. The device according to claim 1, wherein the two pump chambers (2) and the two actuators (6) are configured such that an identical volume change in each of the two pump chambers (2) occurs upon operation of the two actuators (6).

5. The device according to any one of claims 1 to 4, wherein the chamber volumes of the two pump chambers (2) are the same.

6. The device according to any one of claims 1 to 5, wherein the flow rate is between 1 μL / S and 7 μL / S.

7. The device according to any one of claims 1 to 6, wherein the two actuators (6) are piezoelectric membrane actuators.

8. 8. Device according to any one of the preceding claims, wherein the micropump (1) comprises two inlet valves (30) and two outlet valves (31) per pump chamber (2).

9. The device according to any one of the preceding claims, wherein the micropump (1) comprises a symmetrical setup with respect to a plane arranged parallel between the two pump chambers (2).

10. 10. The device according to any one of the preceding claims, further comprising a flow sensor connected to control electronics for controlling the flow of fluid at the common outlet (5) of the micropumps (1).

11. The device of any one of claims 1 to 10, wherein the atomizer comprises any one or combination of a sonic atomization element, an ultrasonic vibration device, or a vaporizer (such as a heater).

12. A device according to any preceding claim, comprising one or a combination of a nicotine-containing aerosol-forming substrate and a tobacco flavour-containing aerosol-forming substrate.

13. A device according to any preceding claim, comprising a viscous liquid aerosol-forming substrate having a viscosity of from 1 mPas to 200 mPas, preferably from 1 mPas to 150 mPas.

14. Use of a device according to any one of claims 1 to 13 in an electronic smoking system.

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