RU2827979C1 - Aerosol generator containing feed elements - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: group of inventions relates to medical equipment, namely to an aerosol generator for an aerosol-generating device, and an aerosol-generating device. Aerosol generator comprises a sprayer based on surface acoustic waves, having a substrate having an active surface forming a spraying section. Sprayer comprises first emitter located on active surface of substrate, and second emitter located on active surface of substrate. Sprayer has a first feed element configured to supply a first liquid aerosol-forming substrate to the spraying section, and a second feed element configured to supply a second aerosol-forming liquid substrate to the spray section. Sprayer comprises controller. Controller is configured to transmit a first control signal to a first emitter to generate surface acoustic waves on the active surface of the substrate. Controller is configured to supply a second control signal to a second emitter to generate surface acoustic waves on the active surface of the substrate. Controller is configured to transmit a first control signal to the first emitter only when the first liquid substrate forming an aerosol is supplied to the spraying section by the first feed element. Controller is configured to supply a second control signal to the second emitter only when the second liquid substrate forming an aerosol is supplied to the spraying section by the second feed element. Aerosol-generating device comprises an aerosol generator and a power supply. Aerosol-generating device has a first portion for storing a liquid for accommodating a first liquid substrate which forms an aerosol. First feed element is configured to supply the first liquid substrate forming an aerosol from the first liquid storage part to the spraying section. Aerosol-generating device includes a second liquid storage portion for accommodating a second liquid aerosol-forming substrate. Second feed element is configured to supply a second liquid substrate forming an aerosol from the second liquid storage part to the spraying section.

EFFECT: providing an aerosol generator for an aerosol-generating device, which enables spraying a plurality of liquid aerosol-forming substrates.

16 cl, 6 dwg

Description

The present invention relates to an aerosol generator for an aerosol generating device comprising a surface acoustic wave atomizer and first and second feed elements. The present invention also relates to an aerosol generating device comprising the aerosol generator.

Aerosol generating systems are known in the art in which an aerosol-forming substrate is heated rather than burned. Typically, in such aerosol generating systems, the aerosol is generated by transferring energy from an aerosol generator of an aerosol generating device to an aerosol-forming substrate. For example, known aerosol generating devices comprise a heater configured to heat and evaporate a liquid aerosol-forming substrate.

Typically, an aerosol generating device is designed and optimized to vaporize or atomize a specific liquid substrate that forms the aerosol. For example, an aerosol generating device may be designed and optimized to vaporize a liquid that has a specific volatility, viscosity, etc.

It would be desirable to provide an aerosol generator for an aerosol generating device that enables atomization of a plurality of liquid substrates that form an aerosol.

According to the first aspect of the present invention, an aerosol generator for an aerosol generating device is proposed. The aerosol generator comprises a surface acoustic wave atomizer, a first feed element, a second feed element, and a controller. The surface acoustic wave atomizer comprises at least one substrate comprising an active surface forming at least one spraying area. The surface acoustic wave atomizer also comprises a first emitter located on the active surface of said at least one substrate, and a second emitter located on the active surface of said at least one substrate. The first feed element is configured to supply the first liquid substrate forming the aerosol to said at least one spraying area. The second feed element is configured to supply the second liquid substrate forming the aerosol to said at least one spraying area. The controller is configured to supply the first control signal to the first emitter for generating surface acoustic waves on the active surface of at least one substrate. The controller is configured to supply the second control signal to the second emitter for generating surface acoustic waves on the active surface of at least one substrate. The controller is configured to supply the first control signal to the first emitter only when the first liquid substrate forming an aerosol is supplied to at least one spraying section by the first feeder. The controller is configured to supply the second control signal to the second emitter only when the second liquid substrate forming an aerosol is supplied to at least one spraying section by the second feeder.

The term "surface acoustic wave" as used herein includes Rayleigh waves, Lamb waves, and Love waves.

Atomization of the first and second liquid aerosol-forming substrates using a surface acoustic wave atomizer provides improved control of the atomization process compared to other known aerosol generators, such as electric heaters, which is an advantage. In other words, the surface acoustic wave atomizer of the aerosol generators according to the present invention provides reliable and stable amounts of atomized liquid aerosol-forming substrate.

The energy required by a surface acoustic wave atomizer to atomize a liquid aerosol-forming substrate is less than the energy required to atomize the same amount of liquid aerosol-forming substrate using known aerosol generators such as electric heaters, which is an advantage.

The use of a single surface acoustic wave atomizer to atomize the first and second liquid substrates to form an aerosol simplifies the design and manufacture of the aerosol generator, which is an advantage.

The use of a surface acoustic wave atomizer comprising a first and a second emitter makes it possible to optimize each emitter for atomizing the first and second liquid aerosol-forming substrates, respectively, which is an advantage.

Preferably, said at least one substrate comprises a common substrate on which the first emitter and the second emitter are located. The common substrate simplifies the design and manufacture of the surface acoustic wave atomizer, which is an advantage.

Said at least one spraying region may be a common spraying region. In embodiments in which said at least one substrate comprises a common substrate, the common spraying region is formed by a common substrate.

Providing a common substrate that forms a common spray area can reduce or minimize the size of the surface acoustic wave atomizer, which is an advantage. Providing a common spray area can simplify the design and manufacture of an aerosol generating device containing an aerosol generator, which is an advantage. For example, providing a common spray area can create conditions for a simple air flow path through the aerosol generating device.

In embodiments in which the aerosol generator comprises a common spraying section, the aerosol generator may comprise a common feed element providing fluid communication between the common spraying section and each of the first feed element and the second feed element. The common feed element may comprise a common channel extending at least partially through the substrate. The common feed element may comprise a common outlet on the active surface of the substrate and is located in the common spraying section. Preferably, the common channel is in fluid communication with the common outlet.

The first feed element may comprise a first channel passing at least partially through the substrate. The first channel may pass between the first inlet on the passive surface of the substrate and the common channel. The first channel may be a capillary tube. The second feed element may comprise a second channel passing at least partially through the substrate. The second channel may be a capillary tube. The second channel may pass between the second inlet on the passive surface of the substrate and the common channel.

The first feeder may comprise a first emitter. During use, the surface acoustic waves generated by the first emitter may direct the first liquid substrate forming an aerosol to said at least one spraying region. In other words, the first liquid substrate forming an aerosol is directed to said at least one spraying region only when the controller supplies the first control signal to the first emitter. In embodiments in which the first feeder comprises a first channel, the surface acoustic waves generated by the first emitter may direct the first liquid substrate forming an aerosol through the first channel.

The second feeder may comprise a second emitter. During use, the surface acoustic waves generated by the second emitter may direct the second liquid substrate forming an aerosol to said at least one spraying region. In other words, the second liquid substrate forming an aerosol is directed to said at least one spraying region only when the controller supplies a second control signal to the second emitter. In embodiments in which the second feeder comprises a second channel, the surface acoustic waves generated by the second emitter may direct the second liquid substrate forming an aerosol through the second channel.

The first feed element may comprise a first flow control element configured to control the flow of the first liquid aerosol-forming substrate to the common spraying area. In embodiments in which the first feed element comprises a first channel, the first flow control element is preferably configured to control the flow of the first aerosol-forming substrate through the first inlet and into the first channel.

The second feed element may comprise a second flow control element configured to control the flow of the second liquid aerosol-forming substrate to the common spraying area. In embodiments in which the second feed element comprises a second channel, preferably the second flow control element is configured to control the flow of the second aerosol-forming substrate through the second inlet and into the second channel.

Each of the first and second flow control elements may comprise at least one passive element. The at least one passive element may comprise at least one of a capillary tube and a capillary wick.

Each of the first and second flow control elements may comprise at least one active element. Said at least one active element may comprise at least one of a micropump, a syringe pump, a piston pump, and an electroosmotic pump.

Preferably, the controller is configured to supply the first flow signal to the first flow control element for starting the flow of the first liquid aerosol-forming substrate to the common spraying area. Preferably, the controller is configured to supply the second flow signal to the second flow control element for starting the flow of the second liquid aerosol-forming substrate to the common spraying area. Preferably, the controller is configured to supply the first stop signal to the first flow control element for blocking the flow of the first liquid aerosol-forming substrate when the controller supplies the second flow signal to the second control element. Preferably, the controller is configured to supply the second stop signal to the second control element for blocking the flow of the second liquid aerosol-forming substrate when the controller supplies the first flow signal to the first control element.

A controller configured to supply flow signals and stop signals to the first and second flow control elements can prevent the simultaneous supply of the first and second liquid aerosol-forming substrates to the common spraying area, which is an advantage. Supplying only one of the first and second liquid aerosol-forming substrates to the common spraying area at a time allows the controller to control only the first emitter or the second emitter, which is an advantage. In other words, the need to simultaneously control the first and second emitters is reduced or eliminated. Reducing or eliminating the need to simultaneously control the first and second emitters can reduce the energy requirement of the aerosol-generating device comprising the aerosol generator, which is an advantage.

The controller may be configured to alternate between supplying the first flow signal and supplying the second flow signal. In other words, the controller may be configured to switch between supplying the first liquid aerosol-forming substrate to the common spraying area and supplying the second liquid aerosol-forming substrate to the common spraying area and back.

Alternating between spraying the first and second liquid substrates forming the aerosol provides alternating delivery of the first and second aerosols to the user, which is an advantage. The controller may be configured to receive user input indicating the user's choice between delivering the first aerosol and the second aerosol. The controller may be configured to provide either the first flow signal or the second flow signal depending on the user input.

The controller may be configured to rapidly alternate between the first flow signal and the second flow signal. The controller may be configured to alternate between the first flow signal and the second flow signal at least every 1 second, preferably at least every 0.1 second. Rapidly alternating the delivery of the first and second aerosols may be perceived by the user as simultaneous delivery of the first and second aerosols, which is an advantage.

Said at least one spraying section may comprise a first spraying section located on the active surface of the substrate for receiving surface acoustic waves generated by the first emitter, and a second spraying section located on the active surface of the substrate for receiving surface acoustic waves generated by the second emitter. Preferably, the first feed element is configured to supply the first liquid substrate forming an aerosol to the first spraying section, and the second feed element is configured to supply the second liquid substrate forming an aerosol to the second spraying section.

Feeding the first and second liquid aerosol-forming substrates to the first and second spraying sections enables simultaneous but separate spraying of the first and second liquid aerosol-forming substrates, which is an advantage. Simultaneous spraying of the first and second liquid aerosol-forming substrates enables mixing of the aerosols generated from the first and second aerosol-forming substrates, which is an advantage. Separate spraying of the first and second liquid aerosol-forming substrates enables adjustment of spraying parameters for each of the first and second liquid aerosol-forming substrates, which is an advantage. For example, each of the first and second emitters can be configured to spray specifically the first and second liquid aerosol-forming substrates, respectively. In particular, the configuration of each of the first and second emitters can depend on one or more fluid properties of the first and second liquid aerosol-forming substrates, such as volatility and viscosity.

The first feeder element may comprise a first channel passing through the substrate. The first channel may be a capillary tube. The first channel may pass between a first inlet on a passive surface of the substrate and a first outlet on an active surface of the substrate, wherein the first outlet is located within the first spray region.

The second feeder may comprise a second channel passing through the substrate. The second channel may be a capillary tube. The second channel may extend between a second inlet on the passive surface of the substrate and a second outlet on the active surface of the substrate, wherein the second outlet is located within the second spray region.

The first feeder may comprise a first emitter. During use, the surface acoustic waves generated by the first emitter may direct the first liquid substrate forming an aerosol to said at least one spraying region. In other words, the first liquid substrate forming an aerosol is directed to said at least one spraying region only when the controller supplies the first control signal to the first emitter. In embodiments in which the first feeder comprises a first channel, the surface acoustic waves generated by the first emitter may direct the first liquid substrate forming an aerosol through the first channel.

The second feeder may comprise a second emitter. During use, the surface acoustic waves generated by the second emitter may direct the second liquid substrate forming an aerosol to said at least one spraying region. In other words, the second liquid substrate forming an aerosol is directed to said at least one spraying region only when the controller supplies a second control signal to the second emitter. In embodiments in which the second feeder comprises a second channel, the surface acoustic waves generated by the second emitter may direct the second liquid substrate forming an aerosol through the second channel.

The first feed element may comprise a first flow control element configured to control the flow of the first liquid substrate forming an aerosol to the first spraying section. In embodiments in which the first feed element comprises a first channel, the first flow control element is preferably configured to control the flow of the first substrate forming an aerosol through the first inlet and into the first channel.

The second feed element may comprise a second flow control element configured to control the flow of the second liquid aerosol-forming substrate to the second spraying section. In embodiments in which the second feed element comprises a second channel, the second flow control element is preferably configured to control the flow of the second aerosol-forming substrate through the second inlet and into the second channel.

Each of the first and second flow control elements may comprise at least one passive element. The at least one passive element may comprise at least one of a capillary tube and a capillary wick.

Each of the first and second flow control elements may comprise at least one active element. Said at least one active element may comprise at least one of a micropump, a syringe pump, a piston pump, and an electroosmotic pump.

Preferably, the controller is configured to supply the first flow signal to the first flow control element for starting the flow of the first liquid aerosol-forming substrate to the first spraying section. Preferably, the controller is configured to supply the second flow signal to the second flow control element for starting the flow of the second liquid aerosol-forming substrate to the second spraying section. Preferably, the controller is configured to supply the first stop signal to the first control element for blocking the flow of the first liquid aerosol-forming substrate. Preferably, the controller is configured to supply the second stop signal to the second control element for blocking the flow of the second liquid aerosol-forming substrate.

Preferably, the controller is configured to supply the first control signal to the first emitter only when the first liquid substrate forming an aerosol is supplied to the first spray section by the first feed element. Preferably, the controller is configured to supply the second control signal to the second emitter only when the second liquid substrate forming an aerosol is supplied to the second spray section by the second feed element.

The surface acoustic wave atomizer may comprise at least one reflector. Preferably, said at least one reflector is located on the active surface of said at least one substrate. Preferably, said at least one reflector is configured to reflect surface acoustic waves generated by at least one of the first emitter and the second emitter. Preferably, said at least one reflector is configured to reflect surface acoustic waves generated by at least one of the first emitter and the second emitter in the direction of said at least one spray section. A reflector configured to reflect surface acoustic waves in the direction of said at least one spray section can increase or maximize the efficiency of the surface acoustic wave atomizer, which is an advantage. The said at least one reflector can be configured to reflect surface acoustic waves generated by each of the first emitter and the second emitter in the direction of the said at least one spray section.

In embodiments in which said at least one spray section comprises a first spray section and a second spray section, said at least one reflector may comprise a common reflector, wherein the first spray section is located between the common reflector and the first emitter, and wherein the second spray section is located between the common reflector and the second emitter.

Providing a common reflector can simplify the design and structure of the surface acoustic wave atomizer, which is an advantage.

The common reflector can prevent the surface acoustic waves generated by the first emitter from propagating to the second spray section, which is advantageous.

The common reflector can prevent the surface acoustic waves generated by the second emitter from propagating to the first spray area, which is an advantage.

The at least one reflector may comprise one or more electrodes.

Said at least one reflector may comprise one or more metal parts located on the active surface of said at least one substrate. Each metal part may have a linear shape. Each metal part may have a curvilinear shape. Said at least one reflector may comprise a plurality of metal parts. Said plurality of metal parts may be located in accordance with a certain pattern on the active surface of said at least one substrate. Preferably, each metal part is substantially parallel to adjacent metal parts forming said at least one reflector.

A portion of said at least one substrate may form at least a portion of said at least one reflector. Said at least one substrate may form at least one protrusion, wherein said at least one protrusion forms at least a portion of said at least one reflector. Said at least one substrate may form at least one recess, wherein said at least one recess forms at least a portion of said at least one reflector.

The surface acoustic wave based atomizer may comprise at least one absorber. Preferably, said at least one absorber is located on the active surface of said at least one substrate. Preferably, said at least one absorber is configured to absorb surface acoustic waves generated by at least one of the first emitter and the second emitter.

In embodiments in which said at least one spray section comprises a first spray section and a second spray section, said at least one absorber may comprise a common absorber, wherein the first spray section is located between the common absorber and the first emitter, and wherein the second spray section is located between the common absorber and the second emitter.

Providing a common absorber can simplify the design and structure of the surface acoustic wave atomizer, which is an advantage.

The common absorber can prevent the surface acoustic waves generated by the first emitter from propagating to the second spray section, which is advantageous.

The common absorber can prevent the surface acoustic waves generated by the second emitter from propagating to the first spray area, which is an advantage.

Said at least one absorber may comprise a material characterized by at least one of low density, low sound velocity, and high viscosity. Said at least one absorber may comprise polydimethylsiloxane.

A portion of said at least one substrate may form at least a portion of said at least one absorber. Said at least one substrate may form at least one protrusion, wherein said at least one protrusion forms at least a portion of said at least one absorber. Said at least one substrate may form at least one recess, wherein said at least one recess forms at least a portion of said at least one absorber.

The aerosol generator may comprise a third emitter located on the active surface of said at least one substrate, and a third feed element configured to supply a third liquid substrate forming an aerosol to said at least one spraying area. Preferably, the controller is configured to supply a third control signal to the third emitter for generating surface acoustic waves on the active surface of said at least one substrate, wherein the controller is configured to supply the third control signal to the third emitter only when the third liquid substrate forming an aerosol is supplied to said at least one spraying area by the third feed element.

In embodiments where said at least one substrate comprises a common substrate, preferably the third emitter is located on the common substrate.

In embodiments in which the aerosol generator comprises a common feed element, the third feed element may comprise a third channel that passes at least partially through the substrate. The third channel may be a capillary tube. The third channel may pass between a third inlet on the passive surface of the substrate and the common channel.

The third feeder may comprise a third emitter. During use, the surface acoustic waves generated by the third emitter may direct the third liquid substrate forming an aerosol to said at least one spraying region. In other words, the third liquid substrate forming an aerosol is directed to said at least one spraying region only when the controller supplies a third control signal to the third emitter. In embodiments in which the third feeder comprises a third channel, the surface acoustic waves generated by the third emitter may direct the third liquid substrate forming an aerosol through the third channel.

The third feed element may comprise a third flow control element configured to control the flow of the third liquid aerosol-forming substrate to the common spraying area. In embodiments in which the third feed element comprises a third channel, preferably the third flow control element is configured to control the flow of the third aerosol-forming substrate through the third inlet and into the third channel.

The third flow control element may comprise at least one passive element. The at least one passive element may comprise at least one of a capillary tube and a capillary wick.

The third flow control element may comprise at least one active element. The at least one active element may comprise at least one of a micropump, a syringe pump, a piston pump, and an electroosmotic pump.

Preferably, the controller is configured to supply a third flow signal to the third flow control element to start the flow of the third liquid substrate forming an aerosol to the common spraying area. Preferably, the controller is configured to supply a third stop signal to the third control element to block the flow of the third liquid substrate forming an aerosol, when the controller supplies the first flow signal to the first control element or the second flow signal to the second control element.

In embodiments in which said at least one spraying section comprises a first spraying section and a second spraying section, said at least one spraying section may further comprise a third spraying section located on the active surface for receiving surface acoustic waves generated by the third emitter, wherein the third feed element is configured to supply a third liquid substrate forming an aerosol to the third spraying section.

The third feeder may comprise a third channel that passes through the substrate. The third channel may be a capillary tube. The third channel may extend between a third inlet on the passive surface of the substrate and a third outlet on the active surface of the substrate, wherein the third outlet is located within the third spray region.

The third feeder may comprise a third emitter. During use, the surface acoustic waves generated by the third emitter may direct the third liquid substrate forming an aerosol to said at least one spraying region. In other words, the third liquid substrate forming an aerosol is directed to said at least one spraying region only when the controller supplies a third control signal to the third emitter. In embodiments in which the third feeder comprises a third channel, the surface acoustic waves generated by the third emitter may direct the third liquid substrate forming an aerosol through the third channel.

The third feed element may comprise a third flow control element configured to control the flow of the third liquid aerosol-forming substrate to the third spraying section. In embodiments in which the third feed element comprises a third channel, preferably the third flow control element is configured to control the flow of the third aerosol-forming substrate through the third inlet and into the third channel.

The third flow control element may comprise at least one passive element. The at least one passive element may comprise at least one of a capillary tube and a capillary wick.

The third flow control element may comprise at least one active element. The at least one active element may comprise at least one of a micropump, a syringe pump, a piston pump, and an electroosmotic pump.

Preferably, the controller is configured to supply a third flow signal to the third flow control element to start the flow of the third liquid substrate forming an aerosol to the third spraying section. Preferably, the controller is configured to supply a third stop signal to the third control element to block the flow of the third liquid substrate forming an aerosol.

Preferably, the controller is configured to supply a third control signal to the third emitter only when the third liquid substrate forming the aerosol is supplied to the third spray section by the third feed element.

In embodiments in which the surface acoustic wave atomizer comprises at least one reflector, said at least one reflector may be configured to reflect surface acoustic waves generated by the third emitter. Said at least one reflector may be configured to reflect surface acoustic waves generated by the third emitter in the direction of said at least one spraying area.

In embodiments in which said at least one spray section comprises a first spray section, a second spray section and a third spray section, said at least one reflector may comprise a common reflector, wherein the first spray section is located between the common reflector and the first emitter, wherein the second spray section is located between the common reflector and the second emitter, and wherein the third spray section is located between the common reflector and the third emitter.

The common reflector may have a three-beam shape. The three-beam shape may provide the possibility of an effective arrangement of the first, second and third emitters on the active surface of at least one substrate, which is an advantage.

In embodiments in which the surface acoustic wave based nebulizer comprises at least one absorber, said at least one absorber may be configured to absorb surface acoustic waves generated by the third emitter.

In embodiments in which said at least one spray section comprises a first spray section, a second spray section and a third spray section, said at least one absorber may comprise a common absorber, wherein the first spray section is located between the common absorber and the first emitter, wherein the second spray section is located between the common absorber and the second emitter, and wherein the third spray section is located between the common absorber and the third emitter.

The common absorber may have a three-beam shape. The three-beam shape may provide the possibility of an effective arrangement of the first, second and third emitters on the active surface of at least one substrate, which is an advantage.

The following preferred and optional features of the aerosol generator may be applicable to any of the aspects and embodiments described herein.

Each of the first emitter, the second emitter and the third emitter may comprise a comb emitter comprising a plurality of electrodes. Preferably, the plurality of electrodes are substantially parallel to each other. Preferably, the comb emitter comprises a first array of electrodes and a second array of electrodes alternating with the first array of electrodes. Preferably, the first array of electrodes is substantially parallel to the second array of electrodes.

Each of the first emitter, the second emitter and the third emitter may be configured to generate surface acoustic waves with a substantially linear wave front. In embodiments in which the emitter is a comb emitter containing a plurality of electrodes, each electrode may be substantially linear.

Each of the first emitter, the second emitter and the third emitter may be configured to generate surface acoustic waves with a curved wave front. In embodiments in which the emitter is a comb emitter comprising a plurality of electrodes, each of the electrodes may be curved. The emitter may be configured to generate surface acoustic waves with a convex wave front. Preferably, the emitter may be configured to generate surface acoustic waves with a concave wave front. The concave wave front may provide a focusing effect, which is an advantage. In other words, the concave wave front may focus the generated surface acoustic waves in the direction of the spray section, which is smaller than the emitter. Focusing the generated surface acoustic waves may increase the speed at which energy is delivered to the liquid substrate forming the aerosol in the spray section, which is an advantage.

The substrate is formed from a substrate material. The substrate may be a piezoelectric material. The substrate material may comprise a monocrystalline material. The substrate material may comprise a polycrystalline material. The substrate material may comprise at least one of quartz, ceramics, barium titanate ( _BaTiO3 ), and lithium niobate ( _LiNbO3 ). The ceramics may comprise lead zirconate titanate (PZT). The ceramics may comprise doping materials 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 comprise both polarized and non-polarized materials.

The substrate may contain a surface treatment agent. The surface treatment agent may be applied to the active surface of the substrate. The surface treatment agent may contain a coating. The coating may contain a hydrophobic material. The coating may contain a hydrophilic material. The coating may contain an oleophobic material. The coating may contain an oleophilic material.

According to the second aspect of the present invention, an aerosol generating device is proposed, comprising an aerosol generator according to the first aspect of the present invention in accordance with any of the embodiments described in this document. The aerosol generating device also comprises a power source, a first liquid storage part and a second liquid storage part. The first liquid storage part is intended to accommodate a first liquid substrate that forms an aerosol, wherein the first feeder element is configured to supply the first liquid substrate that forms an aerosol from the first liquid storage part to said at least one spraying area. The second liquid storage part is intended to accommodate a second liquid substrate that forms an aerosol, wherein the second feeder element is configured to supply the second liquid substrate that forms an aerosol from the second liquid storage part to said at least one spraying area.

In embodiments in which the aerosol generator comprises a third emitter and a third feed element configured to supply a third liquid substrate forming an aerosol to said at least one spraying area, the aerosol generating device preferably comprises a third liquid storage portion. Preferably, the third liquid storage portion is intended to accommodate the third liquid substrate forming an aerosol, wherein the third feed element is configured to supply the third liquid substrate forming an aerosol from the third liquid storage portion to said at least one spraying area.

Each of the first, second and third liquid storage portions may be reusable. In other words, each liquid storage portion may be configured to be refilled by the user to replenish the aerosol-forming liquid substrate in the liquid storage portion. Each liquid storage portion may comprise a refilling opening for placing the aerosol-forming liquid substrate in this liquid storage portion. Each liquid storage portion may comprise a refilling valve between the refilling opening and the liquid storage portion. The refilling valve may allow the aerosol-forming liquid substrate to flow through the refilling opening into the liquid storage portion, which is advantageous. The refilling valve may prevent the aerosol-forming liquid substrate from flowing out of the liquid storage portion through the refilling opening, which is advantageous.

Each of the first, second and third liquid storage parts may be replaceable. Each liquid storage part may be designed to be detachable from the aerosol generating device. The aerosol generating device may comprise a cartridge, wherein the cartridge is designed to be detachable from the aerosol generating device, and wherein the cartridge comprises the first, second and third liquid storage parts.

The aerosol generating device may comprise a first aerosol forming liquid substrate within a first liquid storage portion.

The aerosol generating device may comprise a second aerosol forming liquid substrate within a second liquid storage portion.

The aerosol generating device may comprise a third aerosol forming liquid substrate within a third liquid storage portion.

At least one of the first, second and third aerosol-forming liquid substrates may contain nicotine. The nicotine-containing aerosol-forming liquid substrate may be a nicotine salt matrix. The aerosol-forming liquid substrate may contain a material of plant origin. The aerosol-forming liquid substrate may contain tobacco. The aerosol-forming liquid substrate may contain homogenized tobacco material. The aerosol-forming liquid substrate may contain a material that does not contain tobacco. The aerosol-forming liquid substrate may contain homogenized material of plant origin.

At least one of the first, second and third liquid aerosol-forming substrates may comprise at least one aerosol forming agent. The aerosol forming agent is any suitable known compound or mixture of compounds that, when used, facilitate the formation of a dense and stable aerosol. Suitable aerosol forming agents are well known in the art and include, but are not limited to: polyhydric alcohols such as triethylene glycol, 1,3-butanediol and glycerol; esters of polyhydric alcohols such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Aerosol forming agents are polyhydric alcohols or mixtures thereof such as triethylene glycol, 1,3-butanediol and glycerol. The liquid aerosol-forming substrate may contain other additives and ingredients such as flavoring agents.

At least one of the first, second and third aerosol-forming liquid substrates may comprise water.

At least one of the first, second and third liquid aerosol-forming substrates may comprise nicotine and at least one aerosol-forming substance. The aerosol-forming substance may comprise glycerin. The aerosol-forming substance may comprise propylene glycol. The aerosol-forming substance may comprise both glycerin and propylene glycol. The liquid aerosol-forming substrate may have a nicotine concentration of from about 0.1 percent to about 10 percent.

The controller may comprise an electrical circuit connected to a power source and the first, second and third emitters. The electrical circuit may comprise a microprocessor. The microprocessor may be a programmable microprocessor, a microcontroller or a specialized

an integrated circuit (ASIC) or other electronic circuit capable of providing control. The electrical circuit may comprise additional electronic components. The electrical circuit may be configured to regulate the supply of power to each of the first, second and third emitters. The controller may be configured to supply power continuously to at least one of the first, second and third emitters after activation of the aerosol generating device. The controller may be configured to supply power intermittently to at least one of the first, second and third emitters. The controller may be configured to supply power to at least one of the first, second and third emitters during puffs.

Preferably, the controller and the power sources are configured to supply an alternating voltage to each of the first, second and third emitters. Preferably, the alternating voltage is a radio frequency alternating voltage. Preferably, the alternating voltage has a frequency of at least about 20 megahertz. Preferably, the alternating voltage has a frequency of about 20 megahertz to about 100 megahertz, more preferably from about 20 megahertz to about 80 megahertz. An alternating voltage in these ranges can provide at least one of a desired aerosol generation rate and a desired droplet size, which is an advantage.

The power source may be a power supply of any suitable type. 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 be another type of charge storage device, such as a capacitor. The power source may need to be recharged. The power source may have a capacity that allows storing a sufficient amount of energy for one or more uses of the device. For example, the power source may have sufficient capacity to ensure continuous generation of aerosol for a period of approximately six minutes, which corresponds to the typical time required to smoke a regular cigarette, or for a period of multiples of six minutes. In another example, the power source may have sufficient capacity to ensure a predetermined number of uses of the device or individual activations. In one embodiment, the power source is a DC power source having a DC voltage in the range of about 2.5 volts to about 4.5 volts and a DC current in the range of about 1 ampere to about 10 amperes (corresponding to a power source power in the range of about 2.5 watts to about 45 watts).

The aerosol generating device may comprise a DC to AC converter, which may advantageously comprise a Class C, Class D or Class E power amplifier. The DC to AC converter may be located between the power source and each of the first, second and third emitters.

The aerosol generating device may further comprise a DC-DC converter between the power source and the DC-AC converter.

The aerosol generating device may comprise 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 composite materials comprising one or more of such materials, or thermoplastic materials suitable for use in the food or pharmaceutical industries, such as polypropylene, polyetheretherketone (PEEK) and polyethylene. Preferably, the material is lightweight and non-brittle.

The device housing may form an air inlet. The air inlet may be configured to provide ambient air to enter the device housing. Said air inlet may communicate via fluid medium with said at least one spraying section of the aerosol generator. The device may comprise any suitable number of air inlets. The device may comprise a plurality of air inlets.

The device housing may comprise an air outlet. Said air outlet may be designed to allow air to exit the device housing for delivery to the user. Said air outlet may be in fluid communication with said at least one spraying portion of the aerosol generator. The aerosol generating device may comprise a mouthpiece. The mouthpiece may comprise an air outlet. The device may comprise any suitable number of air outlets. The device may comprise a plurality of air outlets.

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

Fig. 1 shows a top view of an aerosol generator according to a first embodiment of the present invention;

Fig. 2 shows a view of the aerosol generator shown in Fig. 1, in cross section along line 1-1;

Fig. 3 shows a top view of an aerosol generator according to a second embodiment of the present invention;

Fig. 4 shows a cross-sectional view of the aerosol generator shown in Fig. 3 along line 3-3;

Fig. 5 shows an aerosol generating device comprising the aerosol generator shown in Fig. 3; and

Fig. 6 shows a top view of an aerosol generator according to a third embodiment of the present invention.

Fig. 1 and Fig. 2 show an aerosol generator 100 according to a first embodiment of the present invention. The aerosol generator 100 comprises a surface acoustic wave atomizer 102, a first feed element 104 for feeding a first liquid aerosol-forming substrate to the surface acoustic wave atomizer 102, and a second feed element 105 for feeding a second liquid aerosol-forming substrate to the surface acoustic wave atomizer 102.

The surface acoustic wave atomizer 102 comprises a substrate 106 comprising a sheet of piezoelectric material, a first emitter 108 located on the active surface 110 of the substrate 106, and a second emitter 109 located on the active surface 110 of the substrate 106. Each of the first and second emitters 108, 109 comprises a first array of electrodes 112 and a second array of electrodes 114 alternating with the first array of electrodes 112. The first and second arrays of electrodes 112, 114 are curvilinear and parallel to each other. During use, each of the first and second emitters 108, 109 generates surface acoustic waves on the active surface 110 of the substrate 106. The curvilinear shapes of the first and second arrays of electrodes 112, 114 produce surface acoustic waves having a concave wave front. The concave wave front of the surface acoustic waves generated by the first emitter 108 is focused in the direction of the first spray section 116 on the active surface 110 of the substrate 106. The concave wave front of the surface acoustic waves generated by the second emitter 109 is focused in the direction of the second spray section 117 on the active surface 110 of the substrate 106.

The first feed element 104 comprises a first channel 118 passing through the substrate 106 between a first inlet 120 on the passive surface 122 of the substrate 106 and a first outlet 124 on the active surface 110 of the substrate 106. The first outlet 124 is located within the first spray section 116. The first feed element 104 also comprises a first flow control element 130 comprising a micropump. During use, the first liquid substrate forming an aerosol is supplied by the first flow control element 130 through the first channel 118 to the first spray section 116, where it is sprayed by surface acoustic waves generated by the first emitter 108.

The second feed element 105 comprises a second channel 119 passing through the substrate 106 between the second inlet 121 on the passive surface 122 of the substrate 106 and the second outlet 125 on the active surface 110 of the substrate 106. The second outlet 125 is located within the second spray section 117. The second feed element 105 also comprises a second flow control element 131 comprising a micropump. During use, the second liquid substrate forming an aerosol is supplied by the second flow control element 131 through the second channel 119 to the second spray section 117, where it is sprayed by surface acoustic waves generated by the second emitter 109.

The aerosol generator 100 also comprises a controller 132 configured to control the first and second emitters 108, 109 and the first and second flow control elements 130, 131. In the embodiment shown in Fig. 1, the controller 132 is located on the substrate 106 of the surface acoustic wave nebulizer 102; however, a person skilled in the art will understand that the controller 132 can be implemented separately from the surface acoustic wave nebulizer 102.

The controller 132 is configured to supply the first control signal to the first emitter 108 for generating surface acoustic waves on the active surface 110 of the substrate 106. The controller 132 is also configured to supply the first flow signals and the first stop signals to the first flow control element 130 for starting and blocking the flow of the first liquid substrate forming an aerosol through the first channel 118 and into the first spray section 116. The controller 132 is configured to supply the first control signal to the first emitter 108 only when the first flow control element 130 supplies the first liquid substrate forming an aerosol to the first spray section 116.

The controller 132 is configured to supply a second control signal to the second emitter 109 for generating surface acoustic waves on the active surface 110 of the substrate 106. The controller 132 is also configured to supply second flow signals and second stop signals to the second flow control element 131 for starting and blocking the flow of the second liquid substrate forming an aerosol through the second channel 119 and into the second spray section 117. The controller 132 is configured to supply the second control signal to the second emitter 109 only when the second flow control element 131 supplies the second liquid substrate forming an aerosol to the second spray section 117.

Fig. 3 and Fig. 4 show an aerosol generator 200 according to a second embodiment of the present invention. The aerosol generator 200 comprises a surface acoustic wave atomizer 202, a first feed element 204 for feeding a first liquid aerosol-forming substrate to the surface acoustic wave atomizer 202, and a second feed element 205 for feeding a second liquid aerosol-forming substrate to the surface acoustic wave atomizer 202.

The surface acoustic wave atomizer 202 comprises a substrate 206 comprising a sheet of piezoelectric material, a first emitter 208 located on an active surface 210 of the substrate 206, and a second emitter 209 located on the active surface 210 of the substrate 206. Each of the first and second emitters 208, 209 comprises a first and second array of electrodes, as described in relation to the first and second emitters 108, 109 shown in Fig. 1. The surface acoustic waves generated by the first and second emitters 208, 209 are focused in the direction of a common spray area 216.

The surface acoustic wave atomizer 202 comprises a common channel 240 extending into the substrate 206 from a common outlet 225 located within a common spray area 216 on the active surface of the substrate 206.

The first feed element 204 comprises a first channel 218 extending into the substrate 206 from the first inlet 220 on the passive surface 222 of the substrate 206. The first channel 218 communicates through a fluid medium with the common channel 240. The first feed element 204 also comprises a first flow control element 230 comprising a micropump. During use, the first liquid substrate forming an aerosol is supplied by the first flow control element 230 through the first channel 218 and the common channel 240 to the common spray section 216, where it is sprayed by surface acoustic waves generated by the first emitter 208.

The second feed element 205 comprises a second channel 219 extending into the substrate 206 from the second inlet 221 on the passive surface 222 of the substrate 206. The second channel 219 communicates through a fluid medium with the common channel 240. The second feed element 205 also comprises a second flow control element 231 comprising a micropump. During use, the second liquid substrate forming an aerosol is supplied by the second flow control element 231 through the second channel 219 and the common channel 240 to the common spray section 216, where it is sprayed by surface acoustic waves generated by the second emitter 209.

The aerosol generator 200 also comprises a controller 232 configured to control the first and second emitters 208, 209 and the first and second flow control elements 230, 231. In the embodiment shown in Fig. 4, the controller 232 is located on the substrate 206 of the surface acoustic wave nebulizer 202; however, a person skilled in the art will understand that the controller 232 can be implemented separately from the surface acoustic wave nebulizer 202.

The controller 232 is configured to supply the first control signal to the first emitter 208 for generating surface acoustic waves on the active surface 210 of the substrate 206. The controller 232 is also configured to supply the first flow signals and the first stop signals to the first flow control element 230 for starting and blocking the flow of the first liquid substrate forming an aerosol to the common spray section 216 through the first channel 218 and the common channel 240. The controller 232 is configured to supply the first control signal to the first emitter 208 only when the first flow control element 230 supplies the first liquid substrate forming an aerosol to the common spray section 216.

The controller 232 is configured to supply a second control signal to the second emitter 209 for generating surface acoustic waves on the active surface 210 of the substrate 206. The controller 22 is also configured to supply second flow signals and second stop signals to the second flow control element 231 for starting and blocking the flow of the second liquid substrate forming an aerosol to the common spray section 216 through the second channel 219 and the common channel 240. The controller 232 is configured to supply the second control signal to the second emitter 209 only when the second flow control element 231 supplies the second liquid substrate forming an aerosol to the common spray section 216.

The controller 232 is configured to supply the second stop signal to the second flow control element 231, when the controller 232 supplies the first flow signal to the first flow control element 230. The controller 232 is also configured to supply the first stop signal to the first flow control element 230, when the controller 232 supplies the flow signal to the second flow control element 231.

Fig. 5 shows a cross-sectional view of an aerosol generating device 300 comprising an aerosol generator 200 shown in Fig. 3 and Fig. 4. The aerosol generating device 300 also comprises a first liquid storage portion 302 comprising a first liquid substrate 304 forming an aerosol, and a second liquid storage portion 303 comprising a second liquid substrate 305 forming an aerosol. The first flow control element 230 of the aerosol generator 200 is configured to supply the first liquid substrate 304 forming an aerosol from the first liquid storage portion 302 to the first inlet 220 of the aerosol generator 200. The second element 231 for controlling the flow of the aerosol generator 200 is configured to supply the second liquid substrate 305 forming the aerosol from the second part 303 for storing the liquid to the second inlet 221 of the aerosol generator 200.

The aerosol generating device 300 also comprises a power source 308 comprising a rechargeable battery for supplying electrical power to the controller 232, the first and second emitters 208, 209 and the first and second flow control elements 230, 231.

The aerosol generating device 300 also comprises a housing 312 in which the aerosol generator 200, the first and second parts 302, 303 for storing liquid and the power source 308 are placed. The housing 312 forms an air inlet 314, a mouthpiece 316 and an air outlet 318. During use, the user puffs on the mouthpiece 316 to draw air through the housing 312 from the air inlet 314 to the air outlet 318. The aerosol generated by the aerosol generator 200 is captured in the air flow through the housing 312 for delivery to the user.

Fig. 6 shows a top view of an aerosol generator 400 according to a third embodiment of the present invention. The aerosol generator 400 is similar to the aerosol generator 100 shown in Fig. 1 and Fig. 2, but contains an additional emitter, a spray section and a feeder. A person skilled in the art will understand that the structure and operation of the aerosol generator 400 are otherwise similar to the structure and operation of the aerosol generator 400.

The aerosol generator 400 comprises a surface acoustic wave atomizer 402, a first feed element 404 for feeding a first liquid aerosol-forming substrate to the surface acoustic wave atomizer 402, a second feed element 405 for feeding a second liquid aerosol-forming substrate to the surface acoustic wave atomizer 402, and a third feed element 454 for feeding a third liquid aerosol-forming substrate to the surface acoustic wave atomizer 402.

The surface acoustic wave atomizer 402 comprises a substrate 406 comprising a sheet of piezoelectric material, a first emitter 408 located on an active surface 410 of the substrate 406, a second emitter 409 located on the active surface 410 of the substrate 406, and a third emitter 458 located on the active surface 410 of the substrate 406. Each of the first, second and third emitters 408, 409, 458 comprises a first and second array of electrodes, as described in relation to the first and second emitters 108, 109 shown in Fig. 1. The surface acoustic waves generated by the first emitter 408 are focused in the direction of the first spray section 416. The surface acoustic waves generated by the second emitter 409 are focused in the direction of the second spray section 417. The surface acoustic waves generated by the third emitter 458 are focused in the direction of the third spray section 466.

The surface acoustic wave atomizer 402 also comprises a reflector 470 having a three-beam shape and located between the first, second and third spray sections 416, 417, 466. The reflector 470 is configured to reflect the surface acoustic waves generated by each of the first, second and third emitters 408, 409, 458 in the direction of the first, second and third spray sections 416, 417, 466, respectively. In an alternative embodiment, the reflector 470 can be replaced by an absorber.

The first feed element 404 comprises a first channel 418 passing through the substrate 406 between a first inlet on the passive surface of the substrate 406 and a first outlet on the active surface 410 of the substrate 406. The first outlet is located within the first spray section 416. The first feed element 404 also comprises a first flow control element comprising a micropump. During use, the first liquid substrate forming an aerosol is supplied by the first flow control element through the first channel 418 to the first spray section 416, where it is sprayed by surface acoustic waves generated by the first emitter 408.

The second feed element 405 comprises a second channel 419 passing through the substrate 406 between a second inlet on the passive surface of the substrate 406 and a second outlet on the active surface 410 of the substrate 406. The second outlet is located within the second spray section 417. The second feed element 405 also comprises a second flow control element comprising a micropump. During use, the second liquid substrate forming an aerosol is supplied by the second flow control element through the second channel 419 to the second spray section 417, where it is sprayed by surface acoustic waves generated by the second emitter 409.

The third feed element 454 comprises a third channel 468 passing through the substrate 406 between a third inlet on the passive surface of the substrate 406 and a third outlet on the active surface 410 of the substrate 406. The third outlet is located within the third spray section 466. The third feed element 454 also comprises a third flow control element comprising a micropump. During use, the third liquid substrate forming an aerosol is supplied by the third flow control element through the third channel 468 to the third spray section 466, where it is sprayed by surface acoustic waves generated by the third emitter 458.

The aerosol generator 400 also comprises a controller 432 configured to control the first, second and third emitters 408, 409, 458 and the first, second and third flow control elements. In the embodiment shown in Fig. 6, the controller 432 is located on the substrate 406 of the surface acoustic wave nebulizer 402; however, one skilled in the art will understand that the controller 432 can be implemented separately from the surface acoustic wave nebulizer 402.

The controller 432 is configured to supply the first control signal to the first emitter 408 for generating surface acoustic waves on the active surface 410 of the substrate 406. The controller 432 is also configured to supply the first flow signals and the first stop signals to the first flow control element for starting and blocking the flow of the first liquid substrate forming an aerosol through the first channel 418 and into the first spray section 416. The controller 432 is configured to supply the first control signal to the first emitter 408 only when the first flow control element supplies the first liquid substrate forming an aerosol to the first spray section 416.

The controller 432 is configured to supply a second control signal to the second emitter 409 for generating surface acoustic waves on the active surface 410 of the substrate 406. The controller 432 is also configured to supply second flow signals and second stop signals to the second flow control element for starting and blocking the flow of the second liquid substrate forming an aerosol through the second channel 419 and into the second spray section 417. The controller 432 is configured to supply the second control signal to the second emitter 409 only when the second flow control element supplies the second liquid substrate forming an aerosol to the second spray section 417.

The controller 432 is configured to supply a third control signal to the third emitter 458 for generating surface acoustic waves on the active surface 410 of the substrate 406. The controller 432 is also configured to supply third flow signals and third stop signals to the third flow control element for starting and blocking the flow of the third liquid substrate forming an aerosol through the third channel 468 and into the third spray section 466. The controller 432 is configured to supply the third control signal to the third emitter 458 only when the third flow control element supplies the third liquid substrate forming an aerosol to the third spray section 466.

Claims (30)

1. An aerosol generator for an aerosol generating device, comprising: a surface acoustic wave atomizer comprising: at least one substrate comprising an active surface forming at least one spray site; a first emitter located on the active surface of said at least one substrate; and a second emitter located on the active surface of said at least one substrate; a first feed element configured to supply a first liquid aerosol-forming substrate to said at least one spraying area; a second feed element configured to supply a second liquid aerosol-forming substrate to said at least one spraying region; and a controller, wherein the controller is configured to supply a first control signal to a first emitter for generating surface acoustic waves on an active surface of said at least one substrate, and the controller is configured to supply a second control signal to a second emitter for generating surface acoustic waves on an active surface of said at least one substrate, wherein the controller is configured to supply the first control signal to the first emitter only when the first liquid substrate forming an aerosol is supplied to said at least one spraying section by the first feeder, and wherein the controller is configured to supply the second control signal to the second emitter only when the second liquid substrate forming an aerosol is supplied to said at least one spraying section by the second feeder. 2. An aerosol generator according to claim 1, characterized in that said at least one substrate contains a common substrate on which the first emitter and the second emitter are located. 3. An aerosol generator according to claim 2, characterized in that said at least one spray section is a common spray section formed by said common substrate, and the aerosol generator further comprises a common feed element that provides fluid communication between the common spray section and each of the first feed element and the second feed element. 4. The aerosol generator of claim 3, wherein the first feed element comprises a first flow control element configured to control the flow of the first aerosol-forming liquid substrate to the common spray area, and the second feed element comprises a second flow control element configured to control the flow of the second aerosol-forming liquid substrate to the common spray area, wherein the controller is configured to supply a first flow signal to the first flow control element to initiate the flow of the first aerosol-forming liquid substrate to the common spray area, wherein the controller is configured to supply a second flow signal to the second flow control element to initiate the flow of the second aerosol-forming liquid substrate to the common spray area, wherein the controller is configured to supply a first stop signal to the first flow control element to block the flow of the first aerosol-forming liquid substrate when the controller supplies the second flow signal to the second control element, and wherein the controller is configured to supply the second stop signal to the second control element to block the flow of the second liquid a substrate forming an aerosol when the controller applies a first flow signal to the first control element. 5. An aerosol generator according to claim 1 or 2, characterized in that said at least one spray section comprises a first spray section located on the active surface for receiving surface acoustic waves generated by the first emitter, and a second spray section located on the active surface for receiving surface acoustic waves generated by the second emitter, wherein the first feed element is configured to supply the first liquid substrate forming the aerosol to the first spray section, and the second feed element is configured to supply the second liquid substrate forming the aerosol to the second spray section. 6. An aerosol generator according to claim 5, characterized in that the controller is configured to supply a first control signal to the first emitter only when the first liquid substrate forming an aerosol is supplied to the first spray section by the first feed element, and the controller is configured to supply a second control signal to the second emitter only when the second liquid substrate forming an aerosol is supplied to the second spray section by the second feed element. 7. An aerosol generator according to claim 5 or 6, further comprising at least one reflector located on the active surface of the substrate for reflecting surface acoustic waves generated by at least one of the first emitter and the second emitter. 8. An aerosol generator according to claim 7, characterized in that said at least one reflector comprises a common reflector, wherein the first spray section is located between the common reflector and the first emitter, and the second spray section is located between the common reflector and the second emitter. 9. An aerosol generator according to claim 5 or 6, further comprising at least one absorber located on the active surface of the substrate for absorbing surface acoustic waves generated by at least one of the first emitter and the second emitter. 10. An aerosol generator according to claim 9, characterized in that said at least one absorber comprises a common absorber, wherein the first spray section is located between the common absorber and the first emitter, and the second spray section is located between the common absorber and the second emitter. 11. An aerosol generator according to any of the preceding paragraphs, further comprising: a third emitter located on the active surface of said at least one substrate; and a third feed element configured to supply a third liquid aerosol-forming substrate to said at least one spraying area; wherein the controller is configured to supply a third control signal to the third emitter for generating surface acoustic waves on the active surface of said at least one substrate, and the controller is configured to supply the third control signal to the third emitter only when the third liquid substrate forming the aerosol is supplied to said at least one spraying section by the third feed element. 12. An aerosol generator according to claim 11, wherein said at least one spray section comprises a first spray section located on the active surface for receiving surface acoustic waves generated by the first emitter, a second spray section located on the active surface for receiving surface acoustic waves generated by the second emitter, and a third spray section located on the active surface for receiving surface acoustic waves generated by the third emitter, wherein the first feed element is configured to supply a first liquid substrate forming an aerosol to the first spray section, the second feed element is configured to supply a second liquid substrate forming an aerosol to the second spray section, and the third feed element is configured to supply a third liquid substrate forming an aerosol to the third spray section. 13. The aerosol generator of claim 12, further comprising a reflector located on the active surface of the substrate for reflecting surface acoustic waves generated by each of the first emitter, the second emitter, and the third emitter, wherein the first spray section is located between the reflector and the first emitter, the second spray section is located between the reflector and the second emitter, and the third spray section is located between the reflector and the third emitter. 14. An aerosol generator according to claim 12, further comprising an absorber located on the active surface of the substrate for absorbing surface acoustic waves generated by each of the first emitter, the second emitter and the third emitter, wherein the first spray section is located between the absorber and the first emitter, the second spray section is located between the absorber and the second emitter, and the third spray section is located between the absorber and the third emitter. 15. An aerosol generator according to item 13 or 14, characterized in that the reflector or absorber has a three-beam shape. 16. An aerosol generating device comprising: an aerosol generator according to any of the preceding paragraphs; power supply; a first liquid storage portion for accommodating a first aerosol-forming liquid substrate, wherein the first feed element is configured to supply the first aerosol-forming liquid substrate from the first liquid storage portion to said at least one spraying portion; and a second liquid storage portion for accommodating a second liquid aerosol-forming substrate, wherein the second feed element is configured to supply the second liquid aerosol-forming substrate from the second liquid storage portion to said at least one spraying section.