SMOKING DEVICE AND METHOD FOR AEROSOL-GENERATION

Abstract

A smoking device for aerosol-generation may comprise a device housing, a surface acoustic wave-atomizer (SAW-atomizer), a supply element, and a control system. The device housing may include a storage portion for an aerosol-forming substrate. The SAW-atomizer may include an atomization region, a first transducer, and/or a second transducer. The first transducer is configured to generate first surface acoustic waves that propagate along a surface of the SAW-atomizer. The supply element is arranged to supply the aerosol-forming substrate from the storage portion to the atomization region of the SAW-atomizer. The control system is configured to operate the SAW-atomizer to atomize the aerosol-forming substrate in the atomization region to generate an aerosol. A cartridge for such a smoking device and a method for generating an aerosol in a smoking system are also provided.

Claims

1. A smoking device for aerosol-generation, comprising: a device housing including a storage portion, the storage portion including a storage housing configured to hold an aerosol-forming substrate; a surface acoustic wave-atomizer (SAW-atomizer) including an atomization region and a first transducer, the first transducer configured to generate first surface acoustic waves that propagate along a surface of the SAW-atomizer including the atomization region; a supply element configured to supply the aerosol-forming substrate from the storage portion to the atomization region of the SAW-atomizer; and a control system configured to operate the SAW-atomizer to atomize the aerosol-forming substrate in the atomization region to generate an aerosol.

2. The smoking device according to claim 1, wherein the first transducer is an interdigital transducer including electrodes arranged on a piezoelectric substrate.

3. The smoking device according to claim 1, further comprising: a heater configured to heat the aerosol-forming substrate.

4. The smoking device according to claim 3, wherein the control system is configured to operate the heater to heat the aerosol-forming substrate to a target temperature.

5. The smoking device according to claim 3, wherein the heater is arranged on a same surface of the SAW-atomizer as the atomization region or on an opposite surface of the SAW-atomizer from the atomization region.

6. The smoking device according to claim 1, wherein a portion of the supply element is arranged adjacent the atomization region of the SAW-atomizer and another portion of the supply element is fluidly connected to the storage portion.

7. The smoking device according to claim 1, wherein the supply element is a capillary element and the aerosol-forming substrate is a liquid, the capillary element configured to supply the aerosol-forming substrate to the atomization region of the SAW-atomizer via capillary action.

8. The smoking device according to claim 1, wherein the SAW-atomizer further includes a second transducer configured to generate an electrical signal that is representative of physical information of the atomization region or to generate second surface acoustic waves.

9. The smoking device according to claim 1, wherein the storage portion, the SAW-atomizer, and the supply element are included in a cartridge, and the device housing defines a cavity configured to receive the cartridge.

10. A method for generating an aerosol in a smoking system, the method comprising: providing a surface acoustic wave-atomizer (SAW-atomizer) including an atomization region and a first transducer; providing an aerosol-forming substrate to the atomization region of the SAW-atomizer; and operating the SAW-atomizer to generate, with the first transducer, surface acoustic waves that propagate along a surface of the SAW-atomizer into the atomization region and into the aerosol-forming substrate in the atomization region to atomize the aerosol-forming substrate and generate the aerosol.

11. The method according to claim 10, further comprising: heating the aerosol-forming substrate in the atomization region to a temperature above room temperature.

12. The method according to claim 10, further comprising: providing the SAW-atomizer with a second transducer; and performing a first action or a second action with the second transducer, the first action including outputting, with the second transducer, an output signal that is representative of a physical process in the atomization region and using the output signal to control an operation of the SAW-atomizer, the second action including generating, with the second transducer, second surface acoustic waves that propagate along the surface of the SAW-atomizer into the atomization region and into the aerosol-forming substrate in the atomization region.

13. An aerosol-generating smoking system comprising: the smoking device according to claim 1; and the aerosol-forming substrate in liquid form, the supply element of the smoking device being in fluidic connection with the aerosol-forming substrate in the storage housing of the storage portion.

14. The aerosol-generating system according to claim 13, wherein the aerosol-forming substrate includes at least one aerosol former and a liquid additive.

15. A cartridge of a smoking device for aerosol-generation, the cartridge comprising: a storage portion including a housing configured to hold an aerosol-forming substrate; a surface acoustic wave-atomizer (SAW-atomizer) including an atomization region and a first transducer, the first transducer configured to generate surface acoustic waves that propagate along a surface of the SAW-atomizer including the atomization region; and a supply element configured to supply the aerosol-forming substrate from the housing of the storage portion to the atomization region of the SAW-atomizer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0078] The various features and advantages of the non-limiting embodiments herein may become more apparent upon review of the detailed description in conjunction with the accompanying drawings. The accompanying drawings are merely provided for illustrative purposes and should not be interpreted to limit the scope of the claims. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. For purposes of clarity, various dimensions of the drawings may have been exaggerated.

[0079] FIG. 1 schematically illustrates an aerosol-generating device with a pierceable cartridge and a SAW-atomizer comprising a focusing transducer according to an example embodiment.

[0080] FIG. 2 schematically illustrates an aerosol-generating device with a SAW-atomizer comprising two focusing transducers according to an example embodiment.

[0081] FIG. 3 schematically illustrates an aerosol-generating device with a pierceable cartridge and a pointed SAW-atomizer comprising a focusing transducer according to an example embodiment.

[0082] FIG. 4 shows a SAW-atomizer with a straight transducer according to an example embodiment.

[0083] FIG. 5 shows the SAW-atomizer of FIG. 4 with a reflector according to an example embodiment.

[0084] FIG. 6 shows a SAW-atomizer comprising a straight transducer with a different reflector and an additional heating element according to an example embodiment.

[0085] FIG. 7 shows a SAW-atomizer with a focusing transducer according to an example embodiment.

[0086] FIGS. 8-9 show a top view and a cross-sectional view (along midline A-A) of a SAW-atomizer with a focusing transducer, heating element, and capillary element according to an example embodiment.

[0087] FIGS. 10-11 show cross-sectional views along midlines of further example embodiments of SAW-atomizers with heating elements.

[0088] FIGS. 12-13 show a top view of and a cross-sectional view (along midline B-B) of a SAW-atomizer with two focusing transducers according to an example embodiment.

[0089] FIGS. 14-15 show a top view of and a cross-sectional view (along midline C-C) of a SAW-atomizer with a supply element comprising microchannels according to an example embodiment.

[0090] FIGS. 16-17 show a top view of and a cross-sectional view (along midline D-D) of a SAW-atomizer with a countersunk supply element according to an example embodiment.

[0091] FIG. 18 shows a surface treatment of a SAW-atomizer according to an example embodiment.

DETAILED DESCRIPTION

[0092] It should be understood that when an element or layer is referred to as being “on,” “connected to,” “coupled to,” or “covering” another element or layer, it may be directly on, connected to, coupled to, or covering the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element or layer, there are no intervening elements or layers present. Like numbers refer to like elements throughout the specification. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

[0093] It should be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or section from another region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of example embodiments.

[0094] Spatially relative terms (e.g., “beneath,” “below,” “lower,” “above,” “upper,” and the like) may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It should be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” may encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0095] The terminology used herein is for the purpose of describing various embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes,” “including,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

[0096] Example embodiments are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of example embodiments. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, example embodiments should not be construed as limited to the shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing.

[0097] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, including those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0098] FIG. 1 shows an electronic aerosol-generating device comprising a housing 10 and a mouthpiece 11. The housing comprises a cartridge 16 containing an aerosol-forming substrate (e.g., an aerosol-forming liquid), a surface acoustic wave-atomizer (SAW-atomizer) chip 15, electronics 14 for operating and controlling the SAW-atomizer chip 15, and a battery 13 providing power to the electronics 14 and the SAW-atomizer chip 15. The SAW-atomizer chip 15 may be a rectangular chip comprising a focusing interdigital transducer 20 including a reflector, which will be described in more detail below.

[0099] The cylindrically-shaped cartridge 16 is closed at its distal end facing the SAW-atomizer chip 15 with a sealing element, for example a pierceable or perforable foil 160. The sealing element is configured to be pierced by a supply element in the form of a pointed capillary element 30, for example a needle or a paper strip. The other, distal end of the capillary element 30 reaches to the focusing zone of the transducer 20 on the SAW-atomizer chip 15, the focusing zone corresponding to the atomization region 40 or vaporization region on the SAW-atomizer chip 15.

[0100] FIG. 2 shows another example embodiment of an electronic aerosol-generating device, wherein the same reference numbers are used for the same or similar elements. In FIG. 2, the SAW-atomizer chip 15 comprises two focusing interdigital transducers 20 arranged opposite each other. The atomization region 40 lies in between the two transducers 20.

[0101] Both transducers 20 may be operated to generate surface acoustic waves. By doing this, atomization in the atomization region 40 may be enhanced or less power may be required for achieving a same vaporization rate. Alternatively, one of the two transducers 20 may be operated to provide a signal representative of the effects or condition in the atomization region 40, for example a vaporization rate or presence or absence of liquid. Said signal may be used in the electronics 14 to control and possibly adapt the atomization process.

[0102] In the example embodiment of FIG. 2, the distal end of the cartridge 16 is closed by a layer of porous material 161. The porous material 161 is in contact with a wick 31, for example a strip or strand of fibers or paper strip, the wick 31 extending from the porous material 161 to the atomization region 40 on the SAW-atomizer chip 15. Due to the arrangement of the two transducers 20 having a wave propagation direction substantially perpendicular to the longitudinal axis of the device, the wick 31 lies in between the two transducers 20.

[0103] FIG. 3 shows another example embodiment of an electronic aerosol-generating device, similar to the one shown in FIG. 1, wherein the same reference numbers are used for the same or similar elements. In FIG. 3, the SAW-atomizer chip 15 comprises a pointed tip portion 150 supporting a piercing of a pierceable membrane or foil 160 of the cartridge 16. A capillary 32 is arranged to extend between the inside of the cartridge 16 and the atomization region 40 of the SAW-atomizer chip 15. The capillary 32 may, for example, be a microchannel.

[0104] An optional heater may be arranged on each side of the capillary 32, on top of the capillary 32, or on the back side of the SAW-atomizer chip 15.

[0105] FIGS. 4 to 17 show different non-limiting embodiments of SAW-atomizer chips 15 and examples of the arrangement and embodiments of the transducers, capillary elements, and heating elements.

[0106] In FIG. 4, one interdigital transducer 21 is arranged on a lateral surface portion of a piezoelectric substrate. The transducer 21 comprises a series of straight interlacing electrodes 210 arranged in parallel (straight transducer). The atomization region 40 is indicated by a dotted line and is arranged near the transducer 21 but on an opposite lateral surface portion of the piezoelectric substrate.

[0107] In FIG. 5, the same transducer 21 (as in FIG. 4) is provided with reflector electrodes 215. The straight reflector electrodes 215 are arranged parallel to the electrodes 210 of the transducer 21 and adjacent the side of the transducer 21 opposite the side facing the atomization region 40. The reflector electrodes 215 may reflect surface acoustic waves back into the intended propagation direction (to the right side in the drawing). The transducer 21 may, for example, have 20 electrode pairs and 32 reflector electrodes 215 arranged on a LiNbO.sub.3 substrate. The electrode material may be gold.

[0108] In FIG. 6, a straight transducer 22 may comprise reflector electrodes 216 arranged in between the transducer electrodes 210. A heating element, for example a resistive heater 50 in the form of a printed circuit path, is arranged on the substrate opposite the atomization region 40.

[0109] FIG. 7 is an example of a focusing interdigital transducer 20 having curved and tapering electrodes 211 focusing the generated waves onto a small focusing zone 200 on the surface of the substrate. In between the transducer electrodes 211, curved reflector electrodes 214 are arranged parallel to the transducer electrodes 211.

[0110] FIG. 8 shows the SAW-atomizer chip 15 of FIG. 7 with an integrated heater 50 on the surface of the SAW-atomizer chip 15 and a capillary element or wick 31 in the form of a strip, for example a wick or capillary, arranged over the heater 50 substantially along the direction of the propagation direction of the waves generated by the transducer 20.

[0111] FIG. 9 is a cross-section view of the chip of FIG. 8. The transducer 20 and the heater 50 are arranged on the same surface, the top surface, of the piezoelectric substrate 151, for example a lithium niobate substrate. The wick 31 is partially arranged over the heater 50 and in close contact (e.g., thermal contact) to support the heating of the liquid transported in the wick 31 from a cartridge (not shown) to the atomization region arranged between the transducer 20 and the heater 50.

[0112] FIG. 10 and FIG. 11 show cross-sectional views of further example embodiments of SAW-atomizer chips 15. In FIG. 10, the heater 50 is arranged on an opposite side, the back side, of the substrate 151. The heater 50 is positioned to ‘extend’ into the atomization region and ‘overlap’ with the wick 31 (e.g., with the substrate 151 in between). In order to reduce the distance the heat has to pass through the substrate 151 to arrive at the liquid in the wick 31 or in the atomization region, the thickness of the piezoelectric substrate 151 may be reduced.

[0113] In FIG. 11, the transducer 20 and wick 31 are arranged on the surface of a piezoelectric layer 152, for example LiNbO.sub.3, ZnO, AlN, or other piezoelectric materials suitable for layers for SAW-atomizer applications. The heater 50 is arranged on the back side of the piezoelectric layer 152 at approximately a same relative position as described and shown in FIG. 10. The piezoelectric layer 152 is arranged on a support 153, for example a substrate made of glass, ceramic, silicon, or metal. For manufacturing reasons, the heater 50 may be initially applied to the substrate or support 153, and the substrate or support 153 is then provided with the piezoelectric layer 152.

[0114] While the heater has been shown to be arranged on the SAW-atomizer chip, a heater may also be arranged, for example, along a capillary material or channel between the SAW-atomizer chip and a cartridge comprising aerosol-forming liquid.

[0115] In FIG. 12 and FIG. 13, two focusing transducers 20 provided with reflector electrodes are arranged opposite each other on a piezoelectric substrate 151. The two transducers 20 have a common focusing zone 200 in between the transducers 20. In the focusing zone 200, the substrate 151 is provided with a through hole 155 through which an aerosol-forming liquid may be supplied to the top surface of the substrate 151. A capillary element 33 is arranged below the substrate 151 for liquid supply to the bottom of the through hole 155. Optionally, the through hole 155 may be filled with capillary material. In this example embodiment, the atomization area 41 is concentrated on the edges of the through hole 155 at the surface of the substrate 151. The sharp edges support the formation of a relatively thin aerosol-forming liquid layer, which facilitates its vaporization.

[0116] In FIG. 14 and FIG. 15, an aerosol-forming liquid is supplied to the SAW-atomizing chip via a capillary element in the form of a sheet of wick material 34. The sheet of wick material 34 extends onto the surface of the substrate 151 and partially overlies a series of parallel microchannels 35 provided in the surface of the substrate 151. The microchannels 35 extend into the atomization region of the straight transducer 21 also arranged on the surface of the substrate 151. In such an arrangement, the atomization area 41 is concentrated onto the edges of the microchannels 35.

[0117] Similarly, in FIG. 16 and FIG. 17, an atomization area 41 is concentrated on an edge 156 of a substrate 151 by virtue of a countersunk capillary element 36. A portion of the surface of the substrate 151 has been removed, for example by etching. Onto this lower level surface portion, a capillary element 36, such as for example a strip of paper, is arranged flush with the edge 156 of the lower portion to enable liquid to be transported to the edge 156.

[0118] Also surface treatment of the substrate 151 may support the formation of relatively thin aerosol-forming liquid layers. Surface treatment may also support a localization of such a layer. For example, and as shown in FIG. 18, an atomization region 40 (indicated by dotes lines) may be treated in order to form a hydrophilic area, while regions outside an indented atomization region may be hydrophobic areas 158.

[0119] Suitable power ranges to operate an SAW-atomizer chip comprising one or two transducers in the aerosol-generating device may be less than 20 Watts (e.g., between 5 Watts to 15 Watts). Typical transducer electrode distances are in a range of about 100 micrometers (straight transducers), while reflector distances may be in a range of about 50 micrometers.

[0120] Suitable sizes of rectangular SAW-atomizer chips comprising two transducers may range from about 50 mm by 20 mm to 55 mm by 25 mm.

[0121] The aerosol-forming liquid compositions may be 40 percent to 80 percent propylene glycol, 20 percent water, and 0 percent to 40 percent glycerol. The aerosol-generating liquid may be heated to about 65 degrees Celsius. An amount of about 5 microliters of such a liquid may be atomized or vaporized in less than 20 seconds, thus achieving a vaporization rate of about 0.2 to 0.3 microliters per second or higher.

[0122] While a number of example embodiments have been disclosed herein, it should be understood that other variations may be possible. Such variations are not to be regarded as a departure from the spirit and scope of the present disclosure, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.