Aerosol-generator comprising a plurality of atomizers

Abstract

To provide an aerosol-generator comprising a plurality of atomizers.SOLUTION: There are provided an aerosol-generator (200) for an aerosol-generating device (300), and the aerosol-generating device (300) comprising the aerosol-generator (200), the aerosol-generator (200) comprising a plurality of surface acoustic wave atomizers (202, 203), and a supply element (205). Each surface acoustic wave atomizer (202, 203) comprises: a substrate (206, 211) comprising an active surface (208, 213); and at least one transducer (207, 212) positioned on the active surface (208, 213) of the substrate (206, 211) for generating surface acoustic waves on the active surface (208, 213) of the substrate (206, 211). An atomization region (204) is defined between the substrates (206, 211) of the plurality of surface acoustic wave atomizers (202, 203). The supply element (205) is arranged to supply a liquid aerosol-forming substrate to the atomization region (204).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to aerosol generators for aerosol generating devices, each of the aerosol generators including a plurality of surface acoustic wave atomizers and a supply element. The present disclosure also relates to aerosol generating devices including the aerosol generators. [Background technology]

[0002] Aerosol-generating systems in which the aerosol-forming substrate is heated rather than combusted are known in the art. Typically, in such aerosol-generating systems, the aerosol is generated by the transfer of energy from an aerosol generator of an aerosol-generating device to the aerosol-forming substrate. For example, known aerosol-generating devices include a heater arranged to heat and vaporize a liquid aerosol-forming substrate.

[0003] It would be desirable to provide an aerosol generator for an aerosol generating device that is compact and optimized for efficiency and flexibility. Summary of the Invention

[0004] According to a first aspect of the present disclosure, there is provided an aerosol generator for an aerosol generating device, the aerosol generator including a plurality of surface acoustic wave atomizers and a supply element. Each surface acoustic wave atomizer includes a substrate having an active surface and at least one transducer positioned on the active surface of the substrate to generate surface acoustic waves on the active surface of the substrate. An atomization region is defined between the substrates of the plurality of surface acoustic wave atomizers. The supply element is configured to supply a liquid aerosol-forming substrate to the atomization region.

[0005] The term "surface acoustic waves" is used herein to include Rayleigh waves, Lamb waves, and Love waves.

[0006] Advantageously, using a surface acoustic wave atomizer to atomize a liquid aerosol-forming substrate provides improved control of the atomization process compared to other known aerosol generators, such as electric heaters. In other words, the surface acoustic wave atomizer of the aerosol generator according to the present disclosure provides a reliable and consistent amount of atomized liquid aerosol-forming substrate.

[0007] Advantageously, the power required by a surface acoustic wave atomizer to atomize a liquid aerosol-forming substrate is less than the power required to atomize the same amount of liquid aerosol-forming substrate using known aerosol generators such as electric heaters.

[0008] Advantageously, providing multiple surface acoustic wave atomizers can improve control of atomization of the liquid aerosol-forming substrate. Advantageously, providing multiple surface acoustic wave atomizers directed at a single atomization region can increase the area of ​​the atomization region to which the surface acoustic waves are delivered. In other words, providing multiple surface acoustic wave atomizers directed at a single atomization region can increase the area over which the liquid aerosol-forming substrate is atomized within the atomization region.

[0009] Multiple surface acoustic wave atomizers allow surface acoustic waves to be directed toward the spray region from different directions. The multiple surface acoustic wave atomizers may include a first surface acoustic wave atomizer configured to generate surface acoustic waves in a first direction and a second surface acoustic wave atomizer configured to generate surface acoustic waves in a second direction, the second direction being different from the first direction. In particular, providing multiple surface acoustic wave atomizers configured to direct surface acoustic waves toward a single spray region from different directions can increase the area of ​​the spray region to which the surface acoustic waves are delivered. Advantageously, providing multiple surface acoustic wave atomizers directed toward a single spray region from different directions can help prevent liquid aerosol-forming substrate from being delivered to areas of the spray region that do not receive surface acoustic waves.

[0010] In some embodiments, multiple surface acoustic wave atomizers may allow surface acoustic waves with different properties to be directed at the atomization region, such that a single aerosol generator with a single liquid supply may be optimized to produce aerosols from liquid aerosol-forming substrates with different properties.

[0011] The atomization region is a common atomization region for each of the plurality of surface acoustic wave atomizers and is defined between the substrates of the plurality of surface acoustic wave atomizers, and each of the plurality of surface acoustic wave atomizers is arranged such that the surface acoustic waves are directed toward the atomization region.

[0012] Advantageously, providing a common atomization area can reduce or minimize the size of each of the multiple surface acoustic wave atomizers and the overall size of the aerosol generator. Advantageously, providing a common atomization area can simplify the design and manufacture of an aerosol generating device that includes the aerosol generator. For example, providing a common atomization area can facilitate a simple airflow path through the aerosol generating device.

[0013] The aerosol generator includes a plurality of surface acoustic wave atomizers. The aerosol generator may include any suitable number of surface acoustic wave atomizers. For example, the aerosol generator may include two, three, four, five, six, seven, eight, or nine surface acoustic wave atomizers. The plurality of surface acoustic wave atomizers may include at least two surface acoustic wave atomizers. The plurality of surface acoustic wave atomizers may include at least three surface acoustic wave atomizers. The plurality of surface acoustic wave atomizers may consist of two surface acoustic wave atomizers. The plurality of surface acoustic wave atomizers may consist of three surface acoustic wave atomizers.

[0014] In some preferred embodiments, the aerosol generator includes an even number of surface acoustic wave atomizers. When the aerosol generator includes an even number of surface acoustic wave atomizers, the surface acoustic wave atomizers may be provided in pairs of opposing surface acoustic wave atomizers. The pair of opposing surface acoustic wave atomizers may include a first surface acoustic wave atomizer arranged to direct surface acoustic waves in a first direction toward the atomization region, and a second surface acoustic wave atomizer arranged to direct surface acoustic waves in a second direction toward the atomization region, the second direction being parallel to and opposite the first direction.

[0015] The following preferred and optional features of surface acoustic wave atomizers may be applied to the surface acoustic wave atomizers of the present disclosure.

[0016] Each of the plurality of surface acoustic wave atomizers includes a substrate including an active surface and at least one transducer positioned on the active surface of the substrate for generating surface acoustic waves on the active surface of the substrate.

[0017] The substrate is formed from a substrate material. The substrate may be a piezoelectric material. The substrate may include a crystalline material. The substrate material may include a single crystal material. The substrate material may include a polycrystalline material. The substrate material may include at least one of quartz, ceramic, barium titanate (BaTiO3), and lithium niobate (LiNbO3). The ceramic may include lead zirconate titanate (PZT). The ceramic may include a doping material such as Ni, Bi, La, Nd, or Nb ions. The substrate material may be polarized. The substrate material may be non-polarized. The substrate material may include both polarizing and non-polarizing materials.

[0018] In some embodiments, the substrate material may include an amorphous base material. The amorphous base material may include any material onto which a piezoelectric material can be deposited. The amorphous base material may include a polymeric material. The amorphous base material may include a flexible or bendable material, such as a flexible film. The flexible or bendable amorphous base material may be formed from any suitable material, such as a plastic material. Nanocrystals or microcrystals of a piezoelectric material may be deposited or otherwise affixed to the amorphous base material. The nanocrystals or microcrystals of a piezoelectric material may include any material that exhibits piezoelectric properties. For example, the piezoelectric material may include one or more of lead zirconate titanate (PZT), aluminum nitride (AIN), zinc oxide (ZnO), barium titanate (BaTiO), and lithium niobate (LiNbO). For example, the amorphous base material may include zinc oxide (ZnO) nanocrystals or microcrystals. In some embodiments, a flexible film of a piezoelectric material may be deposited on the amorphous base material. In some embodiments, a flexible film of single-crystalline piezoelectric material can be deposited on an amorphous base material. For example, the piezoelectric material can include polyvinylidene fluoride (PVDF). The substrate material can include a flexible film of amorphous base material and a flexible film of polyvinylidene fluoride (PVDF) deposited on the amorphous base material. The flexible film of polyvinylidene fluoride (PVDF) can be single-crystalline.

[0019] Advantageously, by providing the substrate material with an amorphous base material, particularly a flexible or bendable amorphous base material, the substrate may be formed in a curved or folded shape.

[0020] The substrate may include a surface treatment. The surface treatment may be applied to an active surface of the substrate. The surface treatment may include a coating. The coating may include a hydrophobic material. The coating may include a hydrophilic material. The coating may include an oleophobic material. The coating may include an oleophilic material.

[0021] In some preferred embodiments, each of the plurality of surface acoustic wave atomizers may include the same substrate material, hi some embodiments, at least one of the plurality of surface acoustic wave atomizers includes a different substrate material than another one of the plurality of surface acoustic wave atomizers.

[0022] The substrate can have any suitable shape. In some embodiments, at least one of the plurality of surface acoustic wave atomizers includes a substrate having a different shape than another one of the plurality of acoustic wave atomizers. In some preferred embodiments, each of the substrates has the same shape.

[0023] The substrate may have a planar shape. In other words, the substrate may extend generally in a plane. In some embodiments, at least one of the surface acoustic wave atomizers includes a substrate having a planar shape. In some preferred embodiments, each of the substrates has a planar shape.

[0024] The substrate may have a non-planar shape. In other words, the substrate may have sections that extend in different planes. In some embodiments, the substrate may have a curved shape. In some embodiments, the substrate may have a first section that extends in a first plane and a second section that extends in a second plane, where the second plane is not parallel to the first plane.

[0025] In some embodiments, at least one of the surface acoustic wave atomizers includes a substrate having a planar shape and at least one of the surface acoustic wave atomizers includes a substrate having a non-planar shape. In some embodiments, each of the surface acoustic wave atomizers includes a substrate having a planar shape. In some embodiments, each of the surface acoustic wave atomizers includes a substrate having a non-planar shape.

[0026] The substrate may have a cylindrical or polyhedral shape. The substrate may have a cylindrical shape, an elliptical cylindrical shape, a cubic shape, a prismatic shape, a triangular prismatic shape, a trapezoidal prismatic shape, or an isosceles trapezoidal prismatic shape. In some preferred embodiments, each of the substrates has the shape of an isosceles trapezoidal prism.

[0027] The substrate includes an active surface on which surface acoustic waves are generated. The active surface may be planar. The active surface may be a non-planar surface. In some embodiments, all of the active surfaces of the substrates of the plurality of surface acoustic wave atomizers are planar active surfaces. In some embodiments, all of the active surfaces of the substrates of the plurality of surface acoustic wave atomizers are non-planar active surfaces. In some embodiments, some of the active surfaces of the substrates of the plurality of surface acoustic wave atomizers are planar active surfaces and some of the active surfaces of the substrates of the plurality of surface acoustic wave atomizers are non-planar active surfaces.

[0028] The active surface may have any suitable shape. The active surface may have a circular shape, an elliptical shape, or any suitable polygonal shape. The active surface may have a triangular, square, rectangular, pentagonal, hexagonal, or trapezoidal shape. In some preferred embodiments, the active surface has an isosceles trapezoidal shape.

[0029] In some preferred embodiments, the active surface of each substrate of the plurality of surface acoustic wave atomizers has the same shape, hi some embodiments, at least one of the surface acoustic wave atomizers includes a substrate having an active surface that has a shape that differs from the shape of the active surface of the substrate of at least one of the other surface acoustic wave atomizers.

[0030] When the substrate comprises a crystalline material, the active surface of the substrate may be defined by the lattice planes of the crystalline material.

[0031] The substrates of the multiple surface acoustic wave atomizers may be arranged in any suitable configuration.

[0032] In some embodiments, the substrates of multiple surface acoustic wave atomizers may be spaced apart, in other words, a gap or space may be provided between adjacent surface acoustic wave atomizers.

[0033] Preferably, the substrates of the multiple surface acoustic wave atomizers are adjacent to each other. In other words, preferably, the substrates of the multiple surface acoustic wave atomizers are in contact with each other. The multiple surface acoustic wave atomizers may be in direct contact with each other. The multiple surface acoustic wave atomizers may be in indirect contact with each other. When the substrates of the multiple surface acoustic wave atomizers are adjacent to each other, the substrates may be connected to each other. For example, the substrates may be fixed together. The substrates may be fixed together by an adhesive. When adjacent substrates are fixed together by an adhesive, the adjacent substrates are in indirect contact with each other via a layer of adhesive between the substrates.

[0034] The substrate may be arranged to define an opening. Preferably, the substrates of a plurality of surface acoustic wave atomizers are adjacent to one another to define an opening surrounded by the substrates. The opening surrounded by the substrates is preferably in the atomization region. In some embodiments, the opening surrounded by the substrates may form the atomization region.

[0035] In some embodiments in which each substrate has a planar active surface, the active surfaces of the substrates of multiple surface acoustic wave atomizers are positioned in a common plane. Advantageously, positioning the active surfaces of the substrates of multiple surface acoustic wave atomizers in a common plane can simplify the manufacture of the aerosol generator.

[0036] In some embodiments in which the substrates each have a planar active surface, the active surfaces of the substrates of multiple surface acoustic wave atomizers are positioned in a non-coplanar arrangement relative to one another. Advantageously, positioning the active surfaces of the substrates of multiple surface acoustic wave atomizers in a non-coplanar relationship relative to one another can result in a compact aerosol generator. Advantageously, positioning the active surfaces of the substrates of multiple surface acoustic wave atomizers in a non-coplanar relationship relative to one another can provide a space or volume between the substrates to accommodate a liquid supply or to provide an airflow passageway. Advantageously, positioning the active surfaces of the substrates of multiple surface acoustic wave atomizers in a non-coplanar relationship relative to one another can result in control of the airflow over the active surfaces.

[0037] In some preferred embodiments, where each substrate has a planar active surface, the substrates of the surface acoustic wave atomizers are arranged to form a polyhedron shape. Advantageously, arranging the substrates of the surface acoustic wave atomizers in a polyhedron shape allows for a compact aerosol generator.

[0038] In some preferred embodiments, the substrates of the plurality of surface acoustic wave atomizers are adjacent to one another to define an opening surrounded by the substrates, the opening being surrounded by the substrates forming an atomization region, and the plurality of surface acoustic wave atomizers includes at least three surface acoustic wave atomizers. In some preferred embodiments, the plurality of surface acoustic wave atomizers includes at least three surface acoustic wave atomizers, each of the substrates may have an isosceles trapezoidal prism shape.

[0039] In some particularly preferred embodiments, where the plurality of surface acoustic wave atomizers comprises at least three surface acoustic wave atomizers and each substrate has an isosceles trapezoidal prism shape, the active surface may have an isosceles trapezoidal shape, and the shortest ends of each planar isosceles trapezoidal shape may together define an opening. In these particularly preferred embodiments, the active surfaces of the substrates of the plurality of surface acoustic wave atomizers may be arranged in a non-coplanar arrangement so that the plurality of surface acoustic wave atomizers form a truncated pyramid shape. When the plurality of surface acoustic wave atomizers form a truncated pyramid shape, the spray region may be located at the narrow end of the truncated pyramid. When the plurality of surface acoustic wave atomizers form a truncated pyramid shape and the substrates are arranged to form an opening, the opening may be located at the narrow end of the truncated pyramid.

[0040] Advantageously, arranging a plurality of surface acoustic wave atomizer substrates in a substantially truncated pyramidal shape may allow the aerosol generator to be compact.

[0041] In some embodiments, the substrate may comprise a flexible or bendable material. In these embodiments, the substrate may be formed into a bent or curved shape. When the substrate is formed into a bent or curved shape, multiple surface acoustic wave atomizers may be arranged in the form of a cylinder or a cone.

[0042] In embodiments in which multiple surface acoustic wave atomizer substrates are adjacent to one another to define an opening surrounded by the substrates, the opening surrounded by the substrates forming the atomization region may be partially defined by an edge of each substrate. Each edge may have any suitable contour. For example, each edge may have one of a square contour, a round contour, a triangular contour, or a beveled contour. Advantageously, providing each edge with a round, triangular, or beveled contour may facilitate delivery of liquid aerosol-forming substrate to the atomization region.

[0043] Preferably, each of the at least one transducer is arranged to generate surface acoustic waves in a direction towards the spray region. If the substrate is arranged to define an opening, preferably each of the at least one transducer is arranged to generate surface acoustic waves in a direction towards the opening.

[0044] At least one transducer may comprise an interdigitated transducer including a plurality of electrodes. At least one transducer may comprise an interdigitated transducer including electrodes in an interleaved arrangement. Preferably, the plurality of electrodes are substantially parallel to one another. Preferably, the interdigitated transducer comprises a first electrode array and a second electrode array interleaved with the first electrode array. Preferably, the first electrode array is substantially parallel to the second electrode array.

[0045] The transducer may be configured to generate surface acoustic waves having a substantially linear wavefront. In embodiments where the transducer is an interdigitated transducer including multiple electrodes, each electrode may be substantially linear.

[0046] The transducer may be configured to generate surface acoustic waves having a curved wavefront. In embodiments where the transducer is an interdigital transducer including multiple electrodes, each electrode may be curved. The transducer may be configured to generate surface acoustic waves having a convex wavefront. Preferably, the transducer may be configured to generate surface acoustic waves having a concave wavefront. Advantageously, a concave wavefront may provide a focusing effect. In other words, the concave wavefront may focus the generated surface acoustic waves toward an atomization area that is smaller than the transducer. Advantageously, focusing the generated surface acoustic waves may increase the rate at which energy is delivered to the liquid aerosol-forming substrate in the atomization area.

[0047] The array of interdigitated electrodes of the interdigitated transducer may have a symmetrical shape with an axis of symmetry extending in one direction.

[0048] When the substrate comprises a crystalline material and the active surface of the substrate may be defined by lattice planes of the crystalline material, the direction of the symmetry axis of the array of interleaved electrodes may be aligned with the lattice vectors of the lattice planes. Advantageously, aligning the direction of the symmetry axis of the array of interleaved electrodes with the lattice vectors of the lattice planes of the substrate may facilitate the generation of an acoustic wavefront having a desired shape. The desired shape may be a symmetrical shape.

[0049] The at least one converter may be a unidirectional converter or a bidirectional converter. In some preferred embodiments, the at least one converter is a single-phase unidirectional converter.

[0050] The at least one transducer may be a single transducer. The at least one transducer may be multiple transducers. In embodiments where the surface acoustic wave atomizer comprises multiple transducers, each transducer is preferably positioned on the active surface of the substrate such that the surface acoustic waves generated by the transducer travel toward the atomization region.

[0051] Each surface acoustic wave atomizer may include any suitable number of transducers. For example, a surface acoustic wave atomizer may include one, two, three, or four transducers. Preferably, each surface acoustic wave atomizer includes the same number of transducers. Surface acoustic wave atomizers may include different numbers of transducers.

[0052] When a surface acoustic wave atomizer includes multiple transducers, preferably each of the multiple transducers is identical. However, in some embodiments, a surface acoustic wave atomizer including multiple transducers may include different transducers.

[0053] In embodiments in which the surface acoustic wave atomizer includes multiple transducers, each transducer may include an impedance matching component. Providing an impedance matching component may be advantageous when the load impedances of the transducers differ significantly from one another. Providing an impedance matching component may be advantageous when the load impedance of the transducers differs significantly from the source impedance of a controller that generates the drive signal provided to the transducers.

[0054] In embodiments where the surface acoustic wave atomizer includes multiple transducers, the transducers may be connected in series. In embodiments where the surface acoustic wave atomizer includes multiple transducers, the transducers may be connected in parallel.

[0055] The atomization region is defined between the substrates of the plurality of surface acoustic wave atomizers. Each of the plurality of surface acoustic wave atomizers is arranged so that surface acoustic waves are directed toward the atomization region. When the substrates are arranged to define an opening, the opening may be located within the atomization region. In some embodiments, the opening may define the atomization region. Preferably, each of the at least one transducer is arranged to generate surface acoustic waves in a direction toward the opening.

[0056] The aerosol generator may include a supply element arranged to supply the liquid aerosol-forming substrate to the spray region. When the substrate is arranged to define an opening, the supply element may be located at the opening.

[0057] The delivery element may include any suitable type of delivery element capable of delivering a liquid aerosol-forming substrate to the atomization region.

[0058] The delivery element may include at least one of an elongated channel or an elongated wick. In some preferred embodiments, the delivery element includes an elongated wick that extends into the spray region.

[0059] The delivery element may include a channel extending at least partially through the substrate of at least one of the plurality of surface acoustic wave atomizers. The channel may extend between an inlet on an inert surface of the substrate of at least one of the plurality of surface acoustic wave atomizers and an outlet in the atomization region. In these embodiments, the active surface of the substrate may be curved, sloped, or angled at or around the atomization region in a direction toward the inert surface. Advantageously, curving or angling the active surface toward the inert surface at or around the atomization region may facilitate delivery of surface acoustic waves to the outlet.

[0060] In some preferred embodiments, each of the substrates includes an active surface and an opposite inactive surface, and in these embodiments, the delivery element may include a groove formed in the inactive surface of at least one of the substrates, the groove having an end in fluid communication with the spray zone.

[0061] In some particularly preferred embodiments, the plurality of surface acoustic wave atomizers includes a first surface acoustic wave atomizer including a first substrate and a second surface acoustic wave atomizer including a second substrate. In these preferred embodiments, the first substrate channel is in fluid communication with the atomization region. In these particularly preferred embodiments, the first and second grooves may have complementary shapes.

[0062] The supply element may include a flow control element arranged to control the flow of the liquid aerosol-forming substrate into the atomization region. In embodiments in which the supply element comprises a channel, preferably a first flow control element is arranged to control the flow of the aerosol-forming substrate through an inlet of the channel.

[0063] The flow control element may include at least one inert element. The at least one inert element may include at least one of an elongated tube and an elongated wick.

[0064] The flow control element may include at least one active element, which may include at least one of a micropump, a syringe pump, a piston pump, and an electroosmotic pump.

[0065] Preferably, the controller is configured to provide a flow signal to the flow control element to enable the flow of the liquid aerosol-forming substrate to the common spray area. The controller may be configured to provide a stop signal to the control element to disable the flow of the first liquid aerosol-forming substrate.

[0066] The aerosol generator may include a controller. Preferably, the controller is configured to provide a drive signal to at least one transducer of each of the plurality of surface acoustic wave atomizers to generate surface acoustic waves on the active surface of the substrate. To provide the drive signal to the at least one transducer of each of the plurality of surface acoustic wave atomizers, the controller may include a signal generator configured to generate the drive signal and an amplifier configured to amplify the drive signal generated by the signal generator, such that the amplified drive signal can be supplied to the at least one transducer.

[0067] In embodiments in which the surface acoustic wave atomizer comprises multiple transducers connected in series and the control device comprises an amplifier and a signal generator, the drive signal generated by the signal generator may be amplified by the amplifier and supplied to each of the multiple transducers connected in series.

[0068] In embodiments in which the surface acoustic wave atomizer comprises multiple transducers connected in parallel and the control device comprises an amplifier and a signal generator, the drive signal generated by the signal generator may be amplified by the amplifier and supplied to each of the multiple transducers connected in parallel.

[0069] The controller may be configured to provide the same drive signal to the at least one transducer of each of the plurality of surface acoustic wave atomizers. The controller may be configured to provide different drive signals to the at least one transducer of each of the plurality of surface acoustic wave atomizers. Advantageously, providing different drive signals to the at least one transducer of each of the plurality of surface acoustic wave atomizers may enable the aerosol generator to vary the characteristics of the aerosol generated by the generator, allowing the aerosol generator to be optimized for vaporizing different liquid aerosol-forming substrates.

[0070] When the controller is configured to provide the same drive signal to the at least one transducer of each of the plurality of surface acoustic wave atomizers, a splitter may be disposed between the controller and the at least one transducer of each of the plurality of surface acoustic wave atomizers to split the drive signal into multiple channels, with each channel connected to only one of the at least one transducer. The use of a splitter may be beneficial in that the splitter's output for each of the plurality of channels is independent of the load characteristics of each channel. This may be advantageous in that even if one of the at least one transducers malfunctions, the provision of drive signals to the remaining transducers can be maintained under the same conditions.

[0071] When the controller includes a signal generator and an amplifier, a splitter may be disposed between the amplifier and the at least one transducer of each of the surface acoustic wave atomizers, thereby allowing an amplified signal to be provided to each of the at least one transducer even in embodiments in which the controller provides the same drive signal.

[0072] The controller may be configured to simultaneously provide a drive signal to at least one transducer of each of the plurality of surface acoustic wave atomizers. Advantageously, simultaneously providing a drive signal to at least one transducer of each of the plurality of surface acoustic wave atomizers may provide optimized atomization of the liquid aerosol-forming substrate in the atomization region and may allow for easy programming of the controller.

[0073] The controller may be configured to sequentially provide a drive signal to the at least one transducer of each of the plurality of surface acoustic wave atomizers. In other words, the controller may be configured to sequentially provide a drive signal to the at least one transducer of each of the plurality of surface acoustic wave atomizers. Advantageously, sequentially providing a drive signal to the at least one transducer of each of the plurality of surface acoustic wave atomizers may enable the aerosol generator to vary the properties of the aerosol generated by the generator over time.

[0074] When the control device is configured to sequentially provide a drive signal to at least one transducer of each of a plurality of surface acoustic wave atomizers, the control device may include a switch configured to select a transducer of the at least one transducer to which the drive signal is provided. The control device may include a signal source. The signal source may be configured to determine the frequency of the drive signal. The signal source may determine the frequency of the drive signal depending on the position of the switch. In other words, the frequency of the drive signal may be adapted to the characteristics of the transducer to which the drive signal is provided.

[0075] The switch can be configured to change its position in less than 1 millisecond, which can allow for continuous operation of the at least one transducer within a short time interval, allowing for the generation of aerosols with more specific properties over a given period of time.

[0076] The controller may be configured to provide a respective drive signal to the at least one transducer of each of the plurality of surface acoustic wave atomizers. In other words, the controller may be configured to selectively provide a drive signal to the at least one transducer of each of the plurality of surface acoustic wave atomizers. Advantageously, providing a drive signal to the at least one transducer of each of the plurality of surface acoustic wave atomizers enables the aerosol generator to be used with different liquid aerosol-forming substrates, with each surface acoustic wave atomizer optimized to vaporize a different liquid aerosol-forming substrate.

[0077] In some embodiments, the aerosol generator includes a plurality of controllers, hi some embodiments, each surface acoustic wave atomizer includes a controller configured to provide a drive signal to at least one transducer.

[0078] In embodiments in which the aerosol generator includes multiple controllers, each controller may be configured to provide a drive signal to only one of the at least one transducer, which may be useful in aerosol generators in which each of the at least one transducers is different from the others.

[0079] In embodiments in which the surface acoustic wave atomizer includes multiple transducers, such as multiple transducers connected in series or parallel, the transducers may be arranged to define a resonant system having a characteristic frequency. The resonant system may be arranged to define a resonant frequency substantially equal to the resonant frequency of each of the at least one transducer. In the latter embodiment, the controller may be configured to provide a drive signal having a frequency substantially equal to the resonant frequency of one of the at least one transducer. When the drive signal has such a frequency, it has been found that the drive signal is primarily transmitted only to transducers whose resonant frequencies substantially match the frequency of the drive signal. Such a configuration may enable sequential activation of the at least one transducer without the need for a dedicated component such as a switch. In other words, one of the at least one transducer may be selectively activated by selecting an appropriate frequency for the drive signal.

[0080] In embodiments in which the aerosol generator comprises a flow control element and the aerosol generator comprises at least one controller, the controller is preferably configured to provide a flow signal to the flow control element to enable the flow of liquid aerosol-forming substrate to the atomization region. Preferably, the controller is configured to provide a stop signal to the control element to disable the flow of liquid aerosol-forming substrate. Preferably, the controller is configured to provide a drive signal to at least one transducer of one or more surface acoustic wave atomizers only when the controller provides a flow signal to the flow control element.

[0081] At least one of the plurality of surface acoustic wave atomizers may include at least one reflector. In some embodiments, each of the plurality of surface acoustic wave atomizers may include at least one reflector. Preferably, the at least one reflector is located on the active surface of the substrate. Preferably, the at least one reflector is positioned to reflect surface acoustic waves generated by the at least one transducer. Preferably, the at least one reflector is positioned to reflect surface acoustic waves generated by the transducer toward the atomization region. Advantageously, a reflector positioned to reflect surface acoustic waves toward the atomization region may increase or maximize the efficiency of the surface acoustic wave atomizer.

[0082] At least one reflector may comprise one or more electrodes.

[0083] The at least one reflector may comprise one or more portions of metal located on the active surface of the substrate. Each portion of metal may have a linear shape. Each portion of metal may have a curved shape. The at least one reflector may comprise a plurality of portions of metal. The plurality of portions of metal may be arranged in a pattern on the active surface of the substrate. Preferably, each portion of metal is substantially parallel to adjacent portions of metal forming the at least one reflector.

[0084] A portion of the substrate may form at least a portion of the at least one reflector. The substrate may define at least one protrusion, the at least one protrusion forming at least a portion of the at least one reflector. The substrate may define at least one recess, the at least one recess forming at least a portion of the at least one reflector.

[0085] The spray region may be positioned between the at least one transducer and the at least one reflector.

[0086] The at least one reflector may be a single reflector. The at least one reflector may be a plurality of reflectors.

[0087] In embodiments in which at least one of the surface acoustic wave atomizers includes multiple transducers, the at least one reflector may be multiple reflectors, and each transducer may be positioned opposite one reflector such that the atomization region is located between the transducer and the corresponding reflector.

[0088] At least one of the plurality of surface acoustic wave atomizers may include at least one absorber. The at least one absorber is preferably positioned on an active surface of a substrate of the surface acoustic wave atomizer. Preferably, the at least one absorber is arranged to absorb surface acoustic waves generated by the at least one transducer. A portion of the substrate may form at least a portion of the at least one absorber. The substrate may define at least one protrusion, the at least one protrusion forming at least a portion of the at least one absorber. The substrate may define at least one recess, the at least one recess forming at least a portion of the at least one absorber.

[0089] At least one absorber may comprise a material having one or more of low density and high viscosity, such as polydimethylsiloxane (PDMS). Advantageously, providing the absorber with one or more materials having low density and high viscosity may provide the absorber with a relatively high sound absorption coefficient. Preferably, the absorber comprises a material through which the speed of sound is relatively low. The absorber may comprise a porous material. In some preferred embodiments, the absorber comprises polydimethylsiloxane (PDMS).

[0090] A portion of the substrate may form at least a portion of at least one absorbent body. The substrate may define at least one protrusion, the at least one protrusion forming at least a portion of the at least one absorbent body. The substrate may define at least one recess, the at least one recess forming at least a portion of the at least one absorbent body.

[0091] The present disclosure further provides an aerosol generating device including an aerosol generator according to the present disclosure. The aerosol generating device may include a control device for controlling at least one transducer of each surface acoustic wave atomizer. The aerosol generating device may include a power source. The aerosol generating device may include a liquid storage portion for receiving a liquid aerosol-forming substrate. A supply element of the aerosol generator may be arranged to supply the liquid aerosol-forming substrate from the liquid storage portion to the spray region.

[0092] The at least one liquid storage portion may be reusable. In other words, the at least one liquid storage portion may be refillable by a user to replenish the at least one liquid storage portion with a liquid aerosol-forming substrate. The at least one liquid storage portion may comprise a fill port for inserting a liquid aerosol-forming substrate into the liquid storage portion. The at least one liquid storage portion may comprise a fill valve between the fill port and the at least one liquid storage portion. Advantageously, the fill valve may allow the liquid aerosol-forming substrate to flow into the at least one liquid storage portion through the fill port. Advantageously, the fill valve may prevent the liquid aerosol-forming substrate from flowing out of the at least one liquid storage portion through the fill port.

[0093] The at least one liquid reservoir may be replaceable. The at least one liquid reservoir may be removable from the aerosol generation device. The aerosol generation device may comprise a cartridge, the cartridge being removable from the aerosol generation device, the cartridge comprising the at least one liquid reservoir.

[0094] The aerosol generating device may include a liquid aerosol-forming substrate contained within at least one liquid reservoir.

[0095] The liquid aerosol-forming substrate may comprise nicotine. The liquid aerosol-forming substrate containing nicotine may be a nicotine salt matrix. The liquid aerosol-forming substrate may comprise a plant-derived material. The liquid aerosol-forming substrate may comprise tobacco. The liquid aerosol-forming substrate may comprise a homogenized tobacco material. The liquid aerosol-forming substrate may comprise a non-tobacco-containing material. The liquid aerosol-forming substrate may comprise a homogenized plant-derived material.

[0096] The liquid aerosol-forming substrate may contain at least one aerosol former. The aerosol former is any suitable known compound or mixture of compounds that facilitates the formation of a dense and stable aerosol upon use. Suitable aerosol formers are well known in the art and include, but are not limited to, polyhydric alcohols (e.g., triethylene glycol, 1,3-butanediol, glycerin), esters of polyhydric alcohols (e.g., glycerol monoacetate, diacetate, or triacetate), and aliphatic esters of monocarboxylic, dicarboxylic, or polycarboxylic acids (e.g., dimethyl dodecanedioate, dimethyl tetradecanedioate). The aerosol former may be a polyhydric alcohol or a mixture thereof (e.g., triethylene glycol, 1,3-butanediol, and glycerin). The liquid aerosol-forming substrate may contain other additives and ingredients (e.g., flavoring agents).

[0097] The liquid aerosol-forming substrate may comprise water.

[0098] The liquid aerosol-forming substrate may include nicotine and at least one aerosol former. The aerosol former may include glycerin. The aerosol former may include propylene glycol. The aerosol former may include both glycerin and propylene glycol. The liquid aerosol-forming substrate may have a nicotine concentration of about 0.1 percent to about 10 percent.

[0099] In embodiments where the inlet of the supply element comprises multiple inlets, the at least one liquid storage portion may include a first liquid storage portion and a second liquid storage portion, the first liquid storage portion for receiving a first liquid aerosol-forming substrate and the first liquid storage portion being in fluid communication with a first inlet of the multiple inlets, and the second liquid storage portion for receiving a second liquid aerosol-forming substrate and the second liquid storage portion being in fluid communication with a second inlet of the multiple inlets.

[0100] The aerosol generating device may comprise a flow control element arranged to control the flow rate of the liquid aerosol-forming substrate from the at least one liquid reservoir into the channel of the supply element.

[0101] The flow control element may include at least one inert element. The at least one inert element may include at least one of an elongated tube and an elongated core. The at least one inert element may comprise an elongated tube. The at least one inert element may include an elongated core.

[0102] The flow control element may include at least one active element. The at least one active element may comprise a pump. The at least one active element may include at least one of a micropump, a syringe pump, a piston pump, and an electroosmotic pump. Preferably, the controller is arranged to provide a control signal to the at least one active element to control the flow rate of the liquid aerosol-forming substrate from the at least one liquid reservoir to the channel of the supply element.

[0103] The control device may include an electrical circuit connected to the power source and the aerosol generator. The control device may comprise an electrical circuit connected to the power source and at least one transducer of each of the plurality of surface acoustic wave atomizers. When the aerosol generator comprises at least one controller, the aerosol generating device's controller may be connected to at least one controller of the aerosol generator. The electrical circuit may comprise a microprocessor. The microprocessor may be a programmable microprocessor, a microcontroller, an application specific integrated chip (ASIC), or other electronic circuitry capable of providing control. The electrical circuit may comprise additional electronic components. The electrical circuit may be configured to regulate power supply from the power source to the aerosol generator. The electrical circuit may be configured to regulate power supply from the power source to the at least one transducer of each of the plurality of surface acoustic wave atomizers. The control device may be configured to continuously supply power to the aerosol generator after activation of the aerosol generating device. The control device may be configured to intermittently supply power to the aerosol generator. The control device may be configured to supply power to the aerosol generator on a puff-by-puff basis.

[0104] Preferably, the controller and power supply are configured to provide an AC voltage to the aerosol generator. Preferably, the controller and power supply are configured to provide an AC voltage to at least one transducer of each of the plurality of surface acoustic wave atomizers. Preferably, the AC voltage is a radio frequency AC voltage. Preferably, the AC voltage has a frequency of at least about 20 megahertz. Preferably, the AC voltage has a frequency of about 20 megahertz to about 100 megahertz, more preferably about 20 megahertz to about 80 megahertz. Advantageously, AC voltages within these ranges can provide at least one of a desired rate of aerosol generation and a desired droplet size.

[0105] The power source may be any suitable type of power source. The power source may be a DC power source. In some preferred embodiments, the power source is a battery, such as a rechargeable lithium-ion battery. The power source may also be another form of charge storage device, such as a capacitor. The power source may require recharging. The power source may have a capacity that allows for the storage of sufficient energy for one or more uses of the device. For example, the power source may have a capacity sufficient to allow for continuous generation of aerosol for approximately six minutes, or a multiple of six minutes, corresponding to the typical time it takes to smoke a conventional cigarette. In another example, the power source may have a capacity sufficient to allow for a given number of uses of the device, or for discontinuous activation. In one embodiment, the power source is a DC power source having a DC supply voltage in the range of about 2.5 volts to about 4.5 volts and a DC supply current in the range of about 1 ampere to about 10 amperes (corresponding to a DC power supply in the range of about 2.5 watts to about 45 watts).

[0106] The aerosol generating device may advantageously include a DC / AC inverter, which may include a class C, class D, or class E power amplifier. The DC / AC inverter may be disposed between the power source and the aerosol generator. The DC / AC inverter may be disposed between the power source and at least one transducer of each of the plurality of surface acoustic wave atomizers.

[0107] The aerosol generating device may further include a DC / DC converter between the power supply and the DC / AC inverter.

[0108] The aerosol generating device may include a temperature sensor disposed at or around the atomizing region of the aerosol generator, and a controller for the aerosol generating device may be configured to control power supplied to the aerosol generator based on the temperature of the atomizing region sensed by the temperature sensor.

[0109] The aerosol generating device may include a liquid detection sensor at or near the spraying region of the aerosol generator, and the controller of the aerosol generating device may be configured to supply power to the aerosol generator when liquid is detected in the spraying region by the liquid detection sensor.

[0110] For example, the aerosol generating device may include a smoke puff detector, such as an airflow sensor or a pressure sensor. The smoke detector may be disposed in an airflow path of the aerosol generating device. The controller of the aerosol generating device may be configured to provide power to the aerosol generator when a smoke puff on the device is detected by the smoke detector.

[0111] The aerosol generating device may include a device housing. The device housing may be elongated. The device housing may comprise any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics, or composites containing one or more of these materials, or thermoplastics suitable for food or pharmaceutical applications, such as polypropylene, polyetheretherketone (PEEK), and polyethylene. Preferably, the material is light and not brittle.

[0112] The device housing may define an air inlet. The air inlet may be configured to allow ambient air to enter the device housing. The air inlet may be in fluid communication with an atomizing region of the aerosol generator. The device may include any number of air inlets. The device may include multiple air inlets.

[0113] The device housing may include an air outlet. The air outlet may be configured to allow air to exit the device housing for delivery to a user. The air outlet may be in fluid communication with an atomizing region of the aerosol generator. The aerosol generating device may include a mouthpiece. The mouthpiece may include an air outlet. The device may include any suitable number of air outlets. The device may include multiple air outlets.

[0114] In some preferred embodiments, the aerosol generating device may include a device housing, and the aerosol generator is disposed within the device housing. In some of these preferred embodiments, the device housing defines at least one air inlet located upstream of the atomizing region and at least one air outlet located downstream of the atomizing region.

[0115] Advantageously, providing an air inlet located upstream of the spray region and at least one air outlet located downstream of the spray region may ensure that the air flow between the air inlet and the air outlet passes through the spray region, which may result in vapor generated by the aerosol generator in the spray region being trapped in the air flow between the air inlet and the air outlet.

[0116] The aerosol generator may be disposed within the device housing to define an airflow path extending between at least one of the plurality of substrates and a portion of the device housing. The aerosol generator may be disposed within the device housing to define an airflow path extending between each of the plurality of substrates and a portion of the device housing.

[0117] Advantageously, defining an airflow path between the substrate and a portion of the device housing facilitates control of airflow through the airflow path and allows the dimensions of the airflow path to be closely controlled.

[0118] The aerosol generator may be attached to the support by an attachment means. The attachment means may comprise a mechanical attachment. The mechanical attachment may comprise a mechanical fastener. The mechanical fastener may comprise a recess in the support into which the aerosol generator may be snap-fit. The mechanical attachment may comprise a spring fastener. The spring fastener may comprise a flat spring or may comprise a pogo pin. The attachment means may comprise an adhesive material such as adhesive tape or glue.

[0119] The support may comprise a power supply. The support may comprise a controller. The support may comprise a splitter. The support may be a printed circuit board (PCB). The PCB may comprise a controller. The PCB may comprise a splitter.

[0120] When the control device includes an electrical circuit for connecting the power source and the aerosol generator and the control device is included in the support, a wire-bonding electrical connection may be provided between the electrical circuit of the support and the aerosol generator. In particular, when the support is a PCB, a wire-bonding electrical connection may be provided between the control circuit of the PCB and the aerosol generator. Providing a wire-bonding electrical connection may be advantageous in that the resulting electrical connection may be stable. The wire-bonding electrical connection may be directly connected to the electrical circuit, for example, by soldering, screwing, or clamping.

[0121] When the control device includes an electrical circuit for connecting the power source and the aerosol generator, the control device can be included in the support, and the aerosol generator can be attached to the support by a spring clamp, the spring clamp being configured to provide an electrical connection between the electrical circuit of the support and the aerosol generator. Providing an electrical connection by a spring clamp can be useful for easily separating the support and the aerosol generator from each other.

[0122] The support may be provided within the aerosol generation device. In particular, the support may be provided within the device housing. The device housing may include a conductive piece configured to provide an electrical connection between the support and the aerosol generator. In particular, in embodiments where the support is a PCB, the PCB may include a contact pin configured to be placed in electrical contact with the conductive piece of the device housing. Similarly, the aerosol generator may include a contact pin configured to be placed in electrical contact with the conductive piece of the device housing. The PCB may include a contact pin configured to be placed in electrical contact with the contact pin of the aerosol generator. In embodiments where the PCB includes a contact pin configured to be placed in electrical contact with the contact pin of the aerosol generator, the electrical connection between the PCB and the aerosol generator may be established without the need for an intermediate conductive piece within the device housing. This may facilitate assembly and replacement of the support and the aerosol generator.

[0123] If the control device is a PCB comprising an electrical circuit connecting the power supply and the aerosol generator, contact pins of the PCB may be provided to the control circuit, and contact pins of the aerosol generator may be provided with at least one transducer. [Brief explanation of the drawings]

[0124] The invention will now be further described, by way of example only, with reference to the accompanying drawings in which:

[0125] [Figure 1] FIG. 1 shows a top view of an aerosol generator according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 shows a cross-sectional view of the aerosol generator of FIG. 1 taken along line 1-1. [Figure 3] FIG. 3 shows a perspective view of the channel of the aerosol generator of FIG. [Figure 4] FIG. 4 shows a top view of an aerosol generator according to a second embodiment of the present disclosure. [Figure 5] FIG. 5 shows a perspective view of the channels of the aerosol generator of FIG. [Figure 6] FIG. 6 shows a cross-sectional view of an aerosol generating device comprising the aerosol generator of FIGS. [Figure 7] FIG. 7 shows a perspective view of an aerosol generator according to a third embodiment of the present disclosure. [Figure 8] FIG. 8 shows a cross-sectional view of a portion of an aerosol generating device including the aerosol generator of FIG. [Figure 9] Figure 9 shows a side view of an aerosol generator according to a fourth embodiment of the present disclosure, Figure 9b shows a top view of the surface acoustic wave atomizer of the aerosol generator of Figure 9a, and Figure 9c shows a rear view of the surface acoustic wave atomizer of the aerosol generator of Figure 9a. [Figure 10] Figure 10a shows a top view of an aerosol generator according to a fifth embodiment of the present disclosure, and Figure 10b shows a perspective view of the aerosol generator of Figure 10a. DETAILED DESCRIPTION OF THE INVENTION

[0126] 1, 2, and 3 show an aerosol generator 100 according to a first embodiment of the present disclosure. The aerosol generator 100 includes multiple surface acoustic wave atomizers in the form of a first surface acoustic wave atomizer 102 and a second acoustic wave atomizer 103. The aerosol generator 100 further includes an atomization region 104 and a supply element 105 for supplying a liquid aerosol-forming substrate to the atomization region 104.

[0127] The first surface acoustic wave atomizer 102 includes a substrate 106 comprising a sheet of piezoelectric material and a transducer 107 disposed on an active surface 108 of the substrate 106. The transducer 107 of the first surface acoustic wave atomizer 102 includes a first electrode array 109 and a second electrode array 110 interleaved with the first electrode array 109. The first and second electrode arrays 109, 110 are linear and parallel to one another. During use, the transducer 107 of the first surface acoustic wave atomizer 102 generates surface acoustic waves on the active surface 108 of the substrate 106. The linear geometry of the first and second electrode arrays 109, 110 results in surface acoustic waves having linear wavefronts directed toward the atomization region 104.

[0128] The second surface acoustic wave atomizer 103 includes a substrate 111 comprising a sheet of piezoelectric material and a transducer 112 disposed on an active surface 113 of the substrate 111. The transducer 112 of the second surface acoustic wave atomizer 103 includes a first electrode array 114 and a second electrode array 115 interleaved with the first electrode array 114. The first and second electrode arrays 114, 115 are linear and parallel to each other. During use, the transducer 112 of the second surface acoustic wave atomizer 103 generates surface acoustic waves on the active surface 113 of the substrate 111. The linear geometry of the first and second electrode arrays 114, 115 results in surface acoustic waves having linear wavefronts directed toward the atomization region 104.

[0129] The substrates 106, 111 of the first and second surface acoustic wave atomizers 102, 103 are positioned adjacent to each other at one end and secured together with an adhesive (not shown). When the substrates 106, 111 are adjacent to each other, the substrates 106, 111 define an opening in their active surfaces 108, 113, which forms the spray region 104. In this embodiment, each substrate 106, 111 has a planar shape, and the substrates 106, 111 are positioned in a common plane, as shown in FIG. 2. The first and second surface acoustic wave atomizers 102, 103 are substantially identical and oriented in opposite directions, with the first acoustic wave atomizer 102 generating surface acoustic waves on the active surface 108 in a first direction toward the spray region 104 and the second surface acoustic wave atomizer 103 generating surface acoustic waves on the active surface 113 in a second direction toward the spray region, the second direction being parallel to and opposite the second direction.

[0130] The supply element 105 is disposed between substrates 106, 111 located between the first and second surface acoustic wave atomizers 102, 103, and includes a channel 116 extending through the substrates 106, 111. An inlet 117 of the channel 116 is formed between an inert surface 118 of the substrate 106 of the first surface acoustic wave atomizer 102 and an inert surface 119 of the substrate 111 of the second surface acoustic wave atomizer 103. An outlet 120 of the channel 116 is formed between the active surface 108 of the first surface acoustic wave atomizer 102 and the active surface 113 of the second surface acoustic wave atomizer 103. In this embodiment, the outlet 120 has a square shape with an axis parallel to the first and second directions. The channel 116 extends between the inlet 117 and the outlet 120. The outlet 120 is positioned within the atomization region 104. In use, a liquid aerosol-forming substrate is supplied to the atomization region 104 through the channel 116 and is atomized by surface acoustic waves generated by the first and second transducers 107,112.

[0131] As shown in Figures 2 and 3, the channel 116 has a cross-sectional area that changes direction from the inlet 117 to the outlet 120. In particular, the channel 116 has a curved wedge shape such that the cross-sectional area of ​​the channel 116 increases in the direction from the inlet 117 to the outlet 120. The smaller cross-sectional area of ​​the channel 116 at the inlet 117 facilitates control of the flow rate of the liquid aerosol-forming substrate into the channel 116. The larger cross-sectional area of ​​the channel 116 at the outlet 120 provides a larger surface area for the liquid aerosol-forming substrate in the spray region 104, promoting atomization of the liquid aerosol-forming substrate. A curved transition is provided between the active surfaces 108, 113 and the channel 116 to facilitate the transfer of energy from the surface acoustic waves to the liquid aerosol-forming substrate in the spray region 104.

[0132] 4 and 5 show an aerosol generator 200 according to a second embodiment of the present disclosure. The aerosol generator 200 comprises a plurality of surface acoustic wave atomizers in the form of a first surface acoustic wave atomizer 202 and a second acoustic wave atomizer 203. The aerosol generator 200 further comprises an atomization region 204 and a supply element 205 for supplying a liquid aerosol-forming substrate to the atomization region 204.

[0133] The first surface acoustic wave atomizer 202 includes a substrate 206 comprising a sheet of piezoelectric material and a transducer 207 disposed on an active surface 208 of the substrate 206. The transducer 207 of the first surface acoustic wave atomizer 202 includes a first electrode array 209 and a second electrode array 210 interleaved with the first electrode array 209. The first and second electrode arrays 209, 210 are curved and parallel to each other. During use, the transducer 207 generates surface acoustic waves on the active surface 208 of the substrate 206. The curved shapes of the first and second electrode arrays 209, 210 result in surface acoustic waves having concave wavefronts that are focused toward the atomization region 204.

[0134] The second surface acoustic wave atomizer 203 includes a substrate 211 comprising a sheet of piezoelectric material and a transducer 212 disposed on an active surface 213 of the substrate 211. The transducer 212 of the second surface acoustic wave atomizer 203 includes a first electrode array 214 and a second electrode array 215 interleaved with the first electrode array 214. The first and second electrode arrays 214, 215 are curved and parallel to each other. During use, the transducer 212 generates surface acoustic waves on the active surface 213 of the substrate 211. The curved shapes of the first and second electrode arrays 214, 215 result in surface acoustic waves having concave wavefronts that are focused toward the atomization region 204.

[0135] The substrates 206, 211 of the first and second surface acoustic wave atomizers 202, 203 are positioned adjacent to one another at one end and secured together with an adhesive (not shown). When the substrates 206, 211 are adjacent to one another, the substrates 206, 211 define openings in the active surfaces 208, 213, which form the spray region 204. In this embodiment, each of the substrates 206, 211 has a planar shape, and the substrates 206, 211 are positioned in a common plane. The first and second surface acoustic wave atomizers 202, 203 are oriented in substantially identical but opposite directions, with the first acoustic wave atomizer 202 generating surface acoustic waves on the active surface 208 in a first direction toward the spray region 204 and the second surface acoustic wave atomizer 203 generating surface acoustic waves on the active surface 213 in a second direction toward the spray region, the second direction being opposite the first direction.

[0136] The supply element 205 is disposed between the substrates 206, 211 of the first and second surface acoustic wave atomizers 202, 203, and the supply element 205 includes a channel 216 extending through the substrates 206, 211. An inlet 217 of the channel 216 is formed between an inert surface 218 of the substrate 206 of the first surface acoustic wave atomizer 202 and an inert surface 219 of the substrate 211 of the second surface acoustic wave atomizer 203. An outlet 220 of the channel 216 is formed between the active surface 208 of the first surface acoustic wave atomizer 202 and the active surface 213 of the second surface acoustic wave atomizer 203. In this embodiment, the outlet 220 has a circular shape with a center that is the focal point of the concave wavefront of the surface acoustic waves generated by the transducers 207, 212. The channel 216 extends between the inlet 217 and the outlet 220. The outlet 220 is positioned within the atomization region 204. In use, a liquid aerosol-forming substrate is supplied to the atomization region 204 through the channel 216 where it is atomized by the surface acoustic waves generated by the first and second transducers 207 , 212 .

[0137] 5, the channel 216 has a cross-sectional area that varies in the direction from the inlet 217 to the outlet 220. In particular, the channel 216 has a curved funnel shape such that the cross-sectional area of ​​the channel 216 increases in the direction from the inlet 217 to the outlet 220. A curved transition is also provided between the active surfaces 208, 213 and the channel 216.

[0138] 6 shows a cross-sectional view of an aerosol-generation device 300 comprising an aerosol generator 200. The aerosol-generation device 300 also includes a liquid reservoir 302 containing a liquid aerosol-forming substrate 304 and a flow control element 306 including a micropump. The micropump is positioned to supply the liquid aerosol-forming substrate 304 from the liquid reservoir 302 to the inlet 217 of the aerosol generator 200.

[0139] The aerosol generating device 300 also includes a power supply 308 that includes a rechargeable battery and a controller 310. The controller 310 is configured to provide a control signal to the flow control element 306 to control the flow rate of the liquid aerosol-forming substrate 304 from the liquid reservoir 302 to the inlet 320 of the aerosol generator 200. The controller 310 is also configured to provide electrical current from the power supply 308 to the aerosol generator 200 to drive the first and second transducers 207, 212.

[0140] The aerosol generating device 300 also includes a housing 312 containing the aerosol generator 200, the liquid reservoir 302, the flow control element 306, the power supply 308, and the controller 310. The housing 312 defines an air inlet 314, a mouthpiece 316, and an air outlet 318. During use, a user draws on the mouthpiece 316 and draws air through the housing 312 from the air inlet 314 to the air outlet 318. The aerosol generated by the aerosol generator 200 is entrained in an airflow through the housing 312 for delivery to the user.

[0141] 7 and 8 show an aerosol generator 400 according to a third embodiment of the present disclosure. The aerosol generator 400 comprises a plurality of surface acoustic wave atomizers in the form of a first surface acoustic wave atomizer 402 and a second acoustic wave atomizer 403. The aerosol generator 400 further comprises a supply element 405 for supplying a liquid aerosol-forming substrate to the atomization region 404, and the atomization region 404.

[0142] The first surface acoustic wave atomizer 402 includes a substrate 406 comprising a sheet of piezoelectric material and a transducer 407 disposed on an active surface 408 of the substrate 406. The second surface acoustic wave atomizer 403 includes a substrate 411 comprising a sheet of piezoelectric material and a transducer 412 disposed on an active surface 413 of the substrate 411. The first and second transducers 407, 412 each include first and second arrays of interleaved electrodes, as described for the first and second transducers 107, 112 in FIGS. 1, 2, and 3. The first and second electrode arrays of the first and second transducers 407, 412, respectively, are linear and parallel to one another. During use, the transducer 407 of the first surface acoustic wave atomizer 402 generates surface acoustic waves on the active surface 408 of the substrate 406. During use, the transducer 412 of the second surface acoustic wave atomizer 403 generates surface acoustic waves on the active surface 413 of the substrate 411. The linear geometry of the electrode arrays of the first and second transducers 407 , 412 results in surface acoustic waves with linear wavefronts directed towards the spray region 404 .

[0143] The substrates 406, 411 of the first and second surface acoustic wave atomizers 402, 403 are positioned adjacent one another at one end and secured together at their adjacent ends with an adhesive (not shown). When the substrates 406, 411 are adjacent one another, the substrates 406, 411 define openings 420 in the active surfaces 408, 413, which form the atomization region 404. In this embodiment, each of the substrates 406, 411 has a substantially cubic shape, with the substrates 406, 411 disposed in different non-parallel planes that intersect where the substrates 406, 411 abut. In this manner, the substrates 406, 411 are arranged in a generally triangular or V-shaped configuration.

[0144] In this embodiment, delivery element 405 is an elongate wick 416 disposed in the space between substrates 406, 411 and extending from an opening 420 between substrates 406, 411 at one end to a liquid reservoir 422 at the opposite end. Liquid reservoir 422 is also disposed in the space between substrates 406, 411. Liquid reservoir 422 contains a liquid aerosol-forming substrate that is delivered to atomization region 404 by elongate wick 416.

[0145] 8 shows the aerosol generator 400 disposed in an aerosol generating device 500. The aerosol generating device 500 includes a hollow, substantially cylindrical housing 512 defining an air inlet 514, and a mouthpiece 516 having an air outlet 518. The aerosol generator 400 is disposed within the housing 512 between the air inlet 514 and the mouthpiece 516 such that the air inlet 514 is located upstream of the atomization region 404 and the air outlet 518 is located downstream of the atomization region 404.

[0146] During use, a user draws on mouthpiece 516, drawing air through housing 512 from air inlet 514 to air outlet 518. The aerosol generated by aerosol generator 300 is entrained in the airflow through housing 512 for delivery to the user.

[0147] Airflow between the air inlet 514 and the air outlet 518 is indicated by the dotted arrows in Figure 8. The aerosol generator is positioned such that an airflow path is defined between the active surfaces 406, 411 of the first and second surface acoustic wave atomizers 402, 403 and the interior surface of the housing 512. The non-coplanar arrangement of the active surfaces 406, 411 allows the aerosol generator 400 and the housing 512 to have complementary shapes, which in turn allows the size and shape of the airflow path between the aerosol generator 400 and the housing 512 to be easily controlled during manufacture of the aerosol generating device 500. Controlling the size and shape of the airflow path ensures that the draw resistance through the device is controlled during manufacture of the aerosol generating device 500.

[0148] 9a, 9b, and 9c show an aerosol generator 600 according to a fourth embodiment of the present disclosure. The aerosol generator 600 comprises a plurality of surface acoustic wave atomizers in the form of a first surface acoustic wave atomizer 602 and a second acoustic wave atomizer 603. The aerosol generator 600 further comprises an atomization region 604 and a supply element 605 for supplying a liquid aerosol-forming substrate to the atomization region 604.

[0149] The first surface acoustic wave atomizer 602 includes a substrate 606 comprising a sheet of piezoelectric material and a transducer 607 disposed on an active surface 608 of the substrate 606. The second surface acoustic wave atomizer 603 includes a substrate 611 comprising a sheet of piezoelectric material and a transducer 612 disposed on an active surface 613 of the substrate 611. The first and second transducers 607, 612 each include first and second arrays of interleaved electrodes, as described with respect to the first and second transducers 107, 112 in FIGS. 1, 2, and 3. The first and second arrays of electrodes of the first and second transducers 607, 612, respectively, are linear and parallel to one another. During use, the transducer 607 of the first surface acoustic wave atomizer 602 generates surface acoustic waves on the active surface 608 of the substrate 606. In use, the transducer 612 of the second surface acoustic wave atomizer 603 generates surface acoustic waves on the active surface 613 of the substrate 611. The linear geometry of the electrode arrays of the first and second transducers 607, 612 results in surface acoustic waves having linear wavefronts directed towards the atomization region 604.

[0150] In this embodiment, the first and second surface acoustic wave atomizers 602, 603 each include a substantially identical substrate 606, 611. Accordingly, only the substrate of the first surface acoustic wave atomizer 602 is described herein and shown in Figures 9b and 9c.

[0151] The substrate 606 of the first surface acoustic wave atomizer 602 has a generally rectangular profile with a generally planar active surface 608. The transducer 607 is positioned toward one end of the active surface 607, and the atomization region 604 is positioned at the opposite end of the active surface 607.

[0152] The substrate 606 also includes an inert surface 618 opposite the active surface 606. The inert surface 618 includes a groove 621 extending centrally along the length of the inert surface 618 from an opening 620 at the end having the atomization region 604 to a cavity 622 formed at the opposite end of the inert surface 618. The groove 621 forms one half of the feed element channel 616 of the aerosol generator, the other half of which is formed by a corresponding groove in the inert surface of the substrate 613 of the second surface acoustic wave atomizer 603. The cavity 622 forms one half of the liquid reservoir of the aerosol generator, the other half of which is formed by a corresponding cavity in the inert surface of the substrate 613 of the second surface acoustic wave atomizer 603.

[0153] The edge of the active surface 608 of the substrate 606 of the first acoustic wave atomizer 602 has a rounded contour at the atomization region 604 that tapers toward the opening 620. The edge of the active surface 608 is also curved or rounded toward the inactive surface 618. This rounded contour of the substrate 606 toward the opening 620 and the inactive surface 618 facilitates the delivery of surface acoustic waves from the transducer 607 to the atomization region 604.

[0154] When the first surface acoustic wave atomizer 602 and the second surface acoustic wave atomizer 603 are arranged for use, the substrate 606 of the first surface acoustic wave atomizer 602 covers the substrate 611 of the second surface acoustic wave atomizer 603 such that the inert surfaces of the substrates 606, 611 contact each other. Grooves 621 in the inert surface 618 of the substrate 606 of the first surface acoustic wave atomizer 602 cover corresponding grooves in the inert surface of the substrate 611 of the second surface acoustic wave atomizer 603, forming channels 616. Cavities 622 in the inert surface 618 of the substrate 606 of the first surface acoustic wave atomizer 602 cover corresponding cavities in the inert surface of the substrate 611 of the second surface acoustic wave atomizer 603, forming liquid reservoirs. The liquid reservoirs are configured to hold a supply of liquid aerosol-forming substrate. The channel 616 fluidly connects the liquid reservoir to the opening 620 at the atomization region 604. The channel 616 thus forms a supply element. Advantageously, this configuration of the surface acoustic wave atomizer provides a compact aerosol generator that is easy to manufacture.

[0155] 10a and 10b show an aerosol generator 700 according to a fifth embodiment of the present disclosure. The aerosol generator 700 includes a plurality of surface acoustic wave atomizers in the form of six surface acoustic wave atomizers 702. The aerosol generator 700 further includes an atomization region 704 and a supply element 705 for supplying a liquid aerosol-forming substrate to the atomization region 704.

[0156] Each of the surface acoustic wave atomizers 702 is identical, and therefore only one of the atomizers will be described.

[0157] The surface acoustic wave atomizer 702 includes a substrate comprising a sheet of piezoelectric material and a transducer 707 disposed on the active surface of the substrate. The transducer 707 comprises first and second interleaved electrode arrays, as described with respect to the first and second transducers 107, 112 in Figures 1, 2, and 3. The first and second electrode arrays of the transducer 707 are linear and parallel to one another. In use, the transducer 707 generates surface acoustic waves on the active surface of the substrate. The linear shape of the electrode array of the transducer 707 results in surface acoustic waves having linear wavefronts directed toward the atomization region 704.

[0158] The substrate of each surface acoustic wave atomizer 702 has a generally isosceles trapezoidal prism shape, and the active surface has an isosceles trapezoidal shape. The substrates are arranged generally in a truncated hexagonal pyramid with the long ends of the substrates abutting together. In this embodiment, the long ends of adjacent substrates are secured together with an adhesive (not shown). The shortest ends of each substrate together define an opening 720. In this embodiment, the supply element 705 is in the form of an elongated wick, one end of which extends through the opening 720 to deliver liquid aerosol-forming substrate to the opening 720 and atomization region 704. Advantageously, this substrate configuration and arrangement provides a compact aerosol generator configuration that is relatively easy to manufacture and arrange within an aerosol-generating device.

[0159] It will be understood that the above-described embodiments are exemplary embodiments of the present disclosure and that other arrangements and configurations of features according to the present disclosure are contemplated.

Claims

1. An aerosol generator for an aerosol generating device, the aerosol generator comprising: A plurality of surface acoustic wave atomizers, each surface acoustic wave atomizer comprising: a substrate comprising an active surface, and a plurality of surface acoustic wave atomizers, each including at least one transducer positioned on the active surface of the substrate for generating a surface acoustic wave on the active surface of the substrate; an atomization region defined between the substrates of the plurality of surface acoustic wave atomizers; and a supply element positioned to supply a liquid aerosol-forming substrate to said atomization region.

2. 2. The aerosol generator of claim 1, wherein the substrates of the plurality of surface acoustic wave atomizers abut one another to define an opening surrounded by the substrates, the opening forming the atomization region.

3. 3. The aerosol generator of claim 2, wherein each of the at least one transducer is positioned to generate a surface acoustic wave in a direction toward the opening.

4. 4. The aerosol generator according to claim 2, wherein each of the substrates has a planar shape.

5. 5. The aerosol generator of claim 4, wherein the substrates of the plurality of surface acoustic wave atomizers are arranged in a common plane.

6. 5. The aerosol generator of claim 4, wherein the substrates of the plurality of surface acoustic wave atomizers are positioned in a non-coplanar arrangement with respect to one another.

7. 5. The aerosol generator of claim 4, wherein the substrates of the plurality of surface acoustic wave atomizers are arranged to form a polyhedron shape.

8. 8. The aerosol generator according to claim 2, wherein the plurality of surface acoustic wave atomizers includes at least three surface acoustic wave atomizers.

9. 9. The aerosol generator of claim 8, wherein each of the substrates has an isosceles trapezoidal prism shape.

10. 10. The aerosol generator of claim 9, wherein each of the active surfaces of the substrate has an isosceles trapezoid shape, the shortest ends of each of the isosceles trapezoid shapes together defining the opening.

11. 11. The aerosol generator of claim 2, wherein an end of each of the substrates partially defines the opening, and each end has a square contour, a round contour, a triangular contour, or a beveled contour.

12. 12. An aerosol generator according to any preceding claim, wherein the supply element comprises an elongate wick extending into the atomization region.

13. 12. The aerosol generator of claim 1, wherein each of the substrates includes an inert surface opposite the active surface, and the supply element includes a groove formed in the inert surface of at least one of the substrates, the groove having an end in fluid communication with the spray region.

14. 14. The aerosol generator of claim 13, wherein the plurality of surface acoustic wave atomizers include a first surface acoustic wave atomizer including a first substrate and a second surface acoustic wave atomizer including a second substrate, the first substrate covering the second substrate such that the inert surfaces of the first substrate and the second substrate contact each other, and the supply element includes a first groove formed in the inert surface of the first substrate and a second groove formed in the inert surface of the second substrate, the first groove and the second groove overlapping each other to form a channel in fluid communication with the atomization region.

15. An aerosol generating device, comprising: An aerosol generator according to any one of claims 1 to 14; a controller for controlling the at least one transducer of each surface acoustic wave atomizer; Power supply and a liquid storage portion for receiving a liquid aerosol-forming substrate, the supply element being positioned to supply the liquid aerosol-forming substrate from the liquid storage portion to the spray region.

16. 16. The aerosol generating device of claim 15, further comprising a device housing, the aerosol generator being positioned within the device housing, the device housing defining at least one air inlet positioned upstream of the spray region and at least one air outlet positioned downstream of the spray region.

17. 17. The aerosol generating device of claim 16 when dependent on claim 6 or 7, wherein the aerosol generator is disposed within the device housing and defines an airflow path extending between at least one of the planar substrates and a portion of the device housing.

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