WO2023067169A1

WO2023067169A1 - A system and method for flow control in aerosol-generating system

Info

Publication number: WO2023067169A1
Application number: PCT/EP2022/079435
Authority: WO
Inventors: Antonio CONSOLANTE; Michele LORENZELLI; Cyrille Poindron
Original assignee: Philip Morris Products S.A.
Priority date: 2021-10-22
Filing date: 2022-10-21
Publication date: 2023-04-27

Abstract

An aerosol-generating system (300) is provided. The aerosol-generating system comprises a storage compartment (105) containing an aerosol-forming substrate, a retention material (115) suitable for retaining the aerosol-forming substrate, and an aerosol generating element (125) proximate to the retention material. The aerosol-generating system comprises an aerosol-forming substrate flow path (110) defined between the storage compartment and the retention material, a ferromagnetic body (120) positioned in the flow path, and an electromagnet (130). Application of power to the electromagnet moves the ferromagnetic body between a first position and a second position, wherein in the first position the ferromagnetic body restricts flow of aerosol-forming substrate to the retention material to a greater degree than in the second position. A method of supplying aerosol-forming substrate to an aerosol-generating element in an aerosol-generating system is also provided.

Description

A SYSTEM AND METHOD FOR FLOW CONTROL IN AEROSOL-GENERATING SYSTEM

The present disclosure relates to an aerosol-generating system and a method of supplying aerosol-forming substrate to an aerosol generating-element in an aerosol-generating system.

One type of aerosol-generating system is an electrically operated smoking system. One type of electrically operated smoking system is a handheld system that comprises a compartment for storing a liquid aerosol-forming substrate and an electrically operated aerosol-generating element, such as a heating element. The aerosol-forming substrate may be transported to the aerosol-generating element using a capillary material. The system may also comprise a source of electrical power for supplying to the aerosol-generating element. When power is supplied to the aerosol-generating element, a vapour of aerosol-forming substrate is generated. An airflow through or past the aerosol-generating element entrains vapour, which cools within the airflow to form an aerosol. The aerosol-generating system may also comprise a mouthpiece, which a user puffs on in use, to draw aerosol into their mouth.

If the capillary material is insufficiently wet with aerosol-forming substrate when the aerosolgenerating element is in use, not enough substrate is transported to the aerosol-generating element. This may lead to undesirable components being produced in the generated aerosol.

When the aerosol-generating system is not in use, aerosol-forming substrate may be transported via the capillary material and may pass the heating element and enter the airflow path. When a user next uses the system, they may draw unvapourised substrate into their mouth.

It would be desirable to provide an aerosol-generating element that provides sufficient aerosol-forming substrate to the aerosol-generating element when in use. It would also be desirable to provide an aerosol-generating system that reduces leakage of aerosol-generating substrate when not in use.

According to an aspect of the present disclosure, there is provided an aerosol-generating system comprising a storage compartment containing an aerosol-forming substrate, a retention material suitable for retaining the aerosol-forming substrate, and an aerosol generating element proximate to the retention material. There is also provided an aerosol-forming substrate flow path defined between the storage compartment and the retention material. A ferromagnetic body may be positioned in the flow path. The aerosol generating system may comprise an electromagnet. Application of power to the electromagnet may move the ferromagnetic body between a first position and a second position. In the first position the ferromagnetic body may restrict flow of aerosol-forming substrate to the retention material to a greater degree than in the second position.

Advantageously, when flow of substrate to the aerosol-generating element is not desired, it may be restricted by the ferromagnetic body. The restricted flow of aerosol-forming substrate when the ferromagnetic body is in the first position reduces the possibility of leakage of aerosol- forming substrate. This allows a more porous (less retentive) retention material to be used. A more porous retention material allows more substrate to be delivered quickly to the aerosolgenerating element when desired.

The aerosol-generating system reduces leakage when not in use, and this advantageously reduces liquid waste. It also reduces the possibility of damage to the device and reduces the possibility of undesirable inhalation of large droplets of unvapourised substrate by the user.

The flow path may comprise a first internal diameter and second internal diameter. The second internal diameter may be greater than the first internal diameter. Preferably, in the first position the ferromagnetic body may be aligned with the first internal diameter. Preferably, in the second position the ferromagnetic body may be aligned with the second internal diameter. The first internal diameter may be closer to the retention material than the second internal diameter. The second internal diameter may be closer to the retention material than the first internal diameter.

A diameter of the ferromagnetic body may be equal to or greater than the first internal diameter of the flow path. This may advantageously allow the ferromagnetic body to restrict the flow of aerosol-forming substrate when in the first position. In the first position, the ferromagnetic body may partially restrict the flow of aerosol-forming substrate. In the first position, the ferromagnetic body may fully restrict the flow of aerosol-forming substrate.

An internal surface of the flow path may be defined by a surrounding wall or walls forming the first internal diameter and the second internal diameter.

The surrounding wall or walls may comprise a taper. The taper may comprise a gradual change in diameter of the surrounding wall or walls. The surrounding wall or walls may be tapered from the second internal diameter to the first internal diameter. When the ferromagnetic body is in the first position, the ferromagnetic body may be in contact with the first internal diameter. The ferromagnetic body may sit within the taper when in the first position. The ferromagnetic body may restrict aerosol-forming substrate flowing into the retention material when the ferromagnetic body is in the first position. The surrounding wall or walls may have a frusto-conical conical shape.

The surrounding wall or walls may comprise a groove or grooves at the second internal diameter. The flow path may comprise a fluid bypass channel at the second internal diameter.

The first internal diameter may be defined at an end of the flow path adjacent to the retention material. When the ferromagnetic body is in the first position the ferromagnetic body may be in contact with the retention material. The first internal diameter may be defined at an end of a flow path adjacent to the storage compartment. The first internal diameter may be defined at any point along the flow path. When the ferromagnetic body is in the first position, the volume of aerosolforming substrate that may be in contact with or flow to the retention material may be equal to the volume of aerosol-forming substrate that may be retained by the retention material. When the ferromagnetic body is in the first position, the volume of aerosol-forming substrate in contact with or able to flow to the retention material may be up to twenty-five, up to fifty, up to seventy-five, or up to one hundred, percent more than the volume of aerosol-forming substrate that may be retained by the retention material.

The electromagnet may be configured to attract the ferromagnetic body to the first position. The electromagnet may be configured to attract the ferromagnetic body to the second position.

The electromagnet may be ring-shaped. The electromagnet may comprise one or more barshaped electromagnets. The electromagnet may surround the flow path. The electromagnet may be positioned at an end of the flow path. The electromagnet may surround an end of the flow path. The electromagnet may be positioned adjacent to the retention material. The electromagnet may be positioned adjacent to the storage compartment. The electromagnet may surround an end of the flow path adjacent to the retention material. The electromagnet may surround an end of the flow path adjacent to the storage compartment.

The aerosol-generating system may further comprise a permanent magnet configured to attract the ferromagnetic body. The permanent magnet may be ring-shaped. The permanent magnet may comprise one or more bar-shaped permanent magnets. The permanent magnet may surround the flow path. The permanent magnet may be positioned at an end of the flow path. In particular, the permanent magnet may surround an end of the flow path. The permanent magnet may be positioned adjacent to the retention material. The permanent magnet may be positioned adjacent to the storage compartment. The permanent magnet may surround an end of the flow path adjacent to the retention material. The permanent magnet may surround an end of the flow path adjacent to the storage compartment.

The permanent magnet may be configured to attract the ferromagnetic body to the first position. When no power is applied to the electromagnet, the ferromagnetic body may be attracted to the first position. This may restrict the flow of aerosol-forming substrate when no power is applied to the electromagnetic. No power may be required to maintain the ferromagnetic body in the first position. Advantageously, this may reduce leakage of aerosol-forming substrate when the system is not in use. When power is applied to the electromagnet, the ferromagnetic body may be attracted to the second position. The magnetic force of the electromagnet may attract the ferromagnetic body away from the permanent magnet. When power is applied to the electromagnet, the magnetic force provided by the permanent magnet and may be equal and opposite to the magnetic force provided by the electromagnet when the ferromagnetic body is in the second position.

The permanent magnet may be configured to attract the ferromagnetic body to the second position. In that case, the electromagnet may be configured to attract the ferromagnetic body to the first position. The aerosol-generating system may comprise a spring in addition to or instead of a permanent magnet. The spring may be resiliently biased to maintain the ferromagnetic body in the second position. The resilient bias of the spring may be sufficient to hold the ferromagnetic body in the second position when the system is held at any orientation. When power is applied to the electromagnet, the ferromagnetic body may be attracted to the first position overcoming the force provided by the spring.

The spring may be resiliently biased to hold the ferromagnetic body in the first position. When power is applied to the electromagnet, the ferromagnetic body may be attracted to the second position overcoming the force provided by the spring.

The ferromagnetic body may be a sphere. The ferromagnetic body may be a disk. The ferromagnetic body may be any shape suitable for restricting flow of aerosol-forming substrate to the retention material in the first position to a greater degree than in the second position.

The ferromagnetic body may comprise a magnetic stainless steel. The ferromagnetic body may be a sphere comprising magnetic stainless steel.

The aerosol-generating element may be a heating element. The aerosol-generating element may be a mesh heating element. The aerosol-generating element may be a perforated heating element. A mesh or perforated heating element may provide a large heating surface area. This large heating surface area may provide efficient vaporisation of aerosol-forming substrate. The heating element may be configured to be resistively heated. The heating element may be configured to be inductively heated.

The heating element, or portions thereof, may comprise or be formed from any material with suitable electrical and mechanical properties, for example a suitable, electrically resistive material. Suitable materials include but are not limited to: semiconductors such as doped ceramics, electrically “conductive” ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys and composite materials made of a ceramic material and a metallic material. Such composite materials may comprise doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbides. Examples of suitable metals include titanium, zirconium, tantalum and metals from the platinum group. Examples of suitable metal alloys include stainless steel, Constantan, nickel-, cobalt-, chromium-, aluminium-, titanium- , zirconium-, hafnium-, niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese- and iron-containing alloys, and super-alloys based on nickel, iron, cobalt, stainless steel, Timetai®, iron-aluminium based alloys and iron-manganese-aluminium based alloys. Timetai® is a registered trade mark of Titanium Metals Corporation, 1999 Broadway Suite 4300, Denver Colorado. In composite materials, the electrically resistive material may optionally be embedded in, encapsulated or coated with an insulating material or vice-versa, depending on the kinetics of energy transfer and the external physicochemical properties required. The heating element, or portions thereof, may comprise a metallic etched foil insulated between two layers of an inert material. In that case, the inert material may comprise Kapton®, all-polyimide or mica foil. Kapton® is a registered trade mark of E.l. du Pont de Nemours and Company, 1007 Market Street, Wilmington, Delaware 19898, United States of America.

The retention material may comprise a capillary material. The retention material may comprise, or may be, a material soaked with, or a material configured to be soaked with, aerosolforming substrate. The retention material may have a fibrous or spongy structure. The retention material may comprise a bundle of capillaries. For example, the retention material may comprise one or more of fibres, threads, and fine bore tubes.

The retention material may comprise sponge-like or foam-like material. The structure of the retention material may form a plurality of small bores or tubes, through which the liquid can be transported by capillary action.

The retention material may comprise any suitable material or combination of materials. Suitable materials include but are not limited to: ceramic- or graphite-based materials in the form of fibres or sintered powders, foamed metal or plastics material, a fibrous material, for example made of spun or extruded fibres, such as cellulose acetate, polyester, or bonded polyolefin, polyethylene, terylene or polypropylene fibres, nylon fibres or ceramic. The retention material may have any suitable capillarity and porosity so as to be used with different aerosol-forming substrates having different physical properties.

The aerosol-forming substrate is preferably absorbed in the retention material. The retention material may be configured to store, or may store, at least 0.02, 0.05, 0.1 , 0.2, or 0.5 ml of aerosolforming substrate. The retention material may be configured to store, or may store, equal to or less than 2 ml or 5 ml of aerosol-forming substrate.

The aerosol-forming substrate may be a liquid aerosol-forming substrate. The aerosolforming substrate may be liquid at room temperature.

The aerosol-generating system may further comprise control electronics. The control electronics may be configured to control the application of power to the electromagnet. The control electronics may be configured to control the movement of the ferromagnetic body. The control electronics may be configured to control supply of power to the aerosol-generating element. The control electronics may comprise a first controller. The first controller may be configured to control the application of power to the electromagnet. The control electronics may comprise a second controller. The second controller may be configured to control supply of power to the aerosolgenerating element. The control electronics may comprise a controller configured to control the supply of power to both the electromagnet and the aerosol-generating element.

The control electronics may be configured move the ferromagnetic body between the first and the second position. The control electronics may be configured to move the ferromagnetic body between the first position and the second position a predetermined number of times in response to a user input. In response to the user input, the control electronics may be configured to sequentially increase and decrease power supplied to the electromagnet a predetermined number of times. For example, the control electronics may be configured to sequentially supply and cut power supplied to the electromagnet a predetermined number of times. The user input may comprise the user pressing a button. The user input may comprise the user applying a negative air pressure to the air outlet. The movement of the ferromagnetic body between the first and second position a predetermined number of times may create a pumping effect. The pumping effect may increase the flow of aerosol-forming substrate to the retention material when compared to the ferromagnetic body being stationary in the first or second positions. The control electronics may be configured to move the ferromagnetic body between the first position and the second position five times in response to a user input. The control electronics may be configured to move the ferromagnetic body between the first position and the second position two, three, four, five, six, seven, eight, nine or ten times in response to a user input. The delivery of aerosol-forming substrate to the retention material by the movement the ferromagnetic body between the first position and the second position a predetermined number of times in response to a user input may be particularly effective when the first internal diameter equal to the diameter of the ferromagnetic body and the surrounding wall or walls comprise a grooves or grooves at the second internal diameter. Advantageously, this configuration improves the delivery of aerosolforming substrate to the retention material.

The control electronics may be configured to control the movement of the ferromagnetic body when the aerosol-generating element is not activated. The ferromagnetic body may be attracted to the first position when the aerosol-generating element is not activated. This may restrict the flow of the aerosol-forming substrate when the aerosol-generating system is not in use by a user. The control electronics may be configured to control the movement of the ferromagnetic body before the aerosol-generating element is activated. The control electronics may be configured to move the ferromagnetic body between the first position and the second position a predetermined number of times in response to a user input, before the aerosol-generating element is activated. This may be before the first use of the aerosol-generating element. This may be before any subsequent usage sessions of the aerosol-generating element. This may advantageously deliver aerosol-forming substrate to the retention material before the aerosolgenerating element is activated for a usage session. This may allow the retention material to be sufficiently wet before the user uses the system. This may prevent formation of aerosol containing undesirable components.

The control electronics may be configured to control the movement of the ferromagnetic body when the aerosol-generating element is activated. The ferromagnetic body may not be attracted to the first position when the aerosol-generating element is activated. The control electronics may be configured to move the ferromagnetic body between the first position and the second position a predetermined number of times in response to a user input, when the aerosolgenerating element is activated. This may allow aerosol-forming substrate to be pumped to the retention material when the aerosol-generating element is activated. This may ensure that a sufficient volume of aerosol-forming substrate is supplied to the aerosol-generating element during use of the aerosol-generating system.

The aerosol-generating system may further comprise an air inlet, an air outlet and an airflow path from the air inlet to the air outlet.

The aerosol-generating element may be configured to be activated by airflow through the airflow path. The aerosol-generating system may further comprise an airflow sensor. The airflow sensor may be configured to detect air flow through the airflow path. The airflow sensor may be configured to activate the aerosol-generating element. The aerosol-generating system may further comprise a mouthpiece configured to allow a user to apply a negative pressure to the mouthpiece and draw air through the airflow path.

The aerosol-generating system may further comprise a power supply. The power supply may be a battery. The power supply may be configured to apply power to the electromagnet. The power supply may be configured to supply power to the aerosol-generating element. The power supply may be configured to apply power to the electromagnet via the control electronics. The power supply may be configured to supply power to the aerosol-generating element via the control electronics.

The aerosol-generating system may further comprise a net. The net may be positioned between the aerosol-forming substrate flow path and the retention material. The net may be positioned at an end of the aerosol-forming substrate flow path adjacent to the retention material. The net may be in physical contact with the retention material. The aerosol-forming substrate may pass through the net to reach the retention material. The net may act as a filter. The net may filter undesirable particles in the aerosol-forming substrate entering the retention material. The net may reduce the number of particles reaching the aerosol-generating element. The net may be positioned between the retention material and the ferromagnetic body. The ferromagnetic body may physically contact the net. The net may be configured to press on the retention material. The net may be configured to evenly press on the retention material. The net may protect the retention material from the impact of the ferromagnetic body. Advantageously, the net may reduce the impact of the ferromagnetic body on the aerosol-generating element. The net may be resilient. The impact of the ferromagnetic body may be absorbed by elastic deformation of the net. The net may be configured to control the density of the retention material when the retention material is in contact with aerosol-forming substrate. The aerosol-generating system may comprise a cartridge and a device. The cartridge may be removably coupled to the device.

The cartridge may comprise the storage compartment, the retention material, the aerosolgenerating element, the aerosol-forming substrate flow path, the ferromagnetic body and the electromagnet.

The device may comprise a power supply and control electronics.

The cartridge may comprise a first pair of electrical contacts. The first pair of electrical contacts may be electrically connected to the electromagnet. The first pair of electrical contacts may be configured to deliver power to the electromagnet. The first pair of electrical contacts may be electrically connected to the aerosol-generating element. The first pair of electrical contacts may be configured to deliver power to the aerosol-generating element. The first pair of electrical contacts may be configured to receive power from a power supply.

The device may comprise a second pair of electrical contacts. The second pair of electrical contacts may be electrically connected to a power supply. The second pair of electrical contacts may be configured to receive power from a power supply. The first pair of electrical contacts may be configured to receive power from a power supply via the second pair of electrical contacts.

When the cartridge is coupled to the device, the first pair of electrical contacts may be in contact with the second pair of electrical contacts. The first and second pairs of electrical contacts may be configured to deliver power to the electromagnet. The first and second pairs of electrical contacts may be configured to deliver power to the aerosol-generating element.

The electrical contacts may comprise one or more of tin, silver, gold, copper, aluminium, steel such as stainless steel, phosphor bronze, tin alloyed with antimony, tin alloyed with zirconium, tin alloyed with bismuth, or tin alloyed with other components improving resistance to organic acids.

According to another aspect of the present disclosure, there may be provided a cartridge for an aerosol-generating system. The cartridge may comprise a storage compartment for containing an aerosol-forming substrate, an electromagnet and electrical contacts configured to receive power from a power supply and deliver power to the electromagnet. The cartridge may further comprise an aerosol-forming substrate flow path configured to transport aerosol-forming substrate from the storage compartment to an aerosol-forming substrate outlet, and a ferromagnetic body situated in the flow path. Application of power to the electromagnet may move the ferromagnetic body between a first position and a second position. In the first position the ferromagnetic body may restrict flow of aerosol-forming substrate to the aerosol-forming substrate outlet to a greater degree than in the second position.

The cartridge may further comprise an aerosol-generating element. The cartridge may further comprise a retention material situated between the aerosolgenerating element and the aerosol-forming substrate outlet. In the first position the ferromagnetic body may restrict flow of aerosol-forming substrate to the retention material to a greater degree than in the second position.

The aerosol-forming substrate flow path may comprise a first internal diameter and second internal diameter greater than the first internal diameter. In the first position the ferromagnetic body may be aligned with the first internal diameter. In the second position the ferromagnetic body may be aligned with the second internal diameter. In the first position the ferromagnetic body may be aligned with the first internal diameter. In the second position the ferromagnetic body may be aligned with the second internal diameter. A diameter of the ferromagnetic body may be equal to or greater than the first internal diameter of the flow path.

An internal surface of the flow path may defined by a surrounding wall or walls forming the first internal diameter and the second internal diameter. The surrounding wall or walls may comprise a taper. The taper may comprise a gradual change in diameter of the surrounding wall or walls. The surrounding wall or walls may be tapered from the second internal diameter to the first internal diameter. The surrounding wall or walls have a frusto-conical shape. The surrounding wall or walls may comprise a groove or grooves at the second internal diameter. The flow path may comprises a fluid bypass channel at the second internal diameter.

The electromagnet may surround an end of the flow path. The electromagnet may be configured to attract the ferromagnetic body to the first position. The electromagnet may be configured to attract the ferromagnetic body to the second position.

The cartridge may further comprise a permanent magnet configured to attract the ferromagnetic body. The permanent magnet may be configured to attract the ferromagnetic body to the first position.

The cartridge may further comprise a spring. When power is applied to the electromagnet, the ferromagnetic body may be attracted to the first position overcoming the resilient bias of the spring.

The ferromagnetic body may be a sphere. The ferromagnetic body may comprise stainless steel.

The cartridge may further comprise an air inlet, an air outlet and an airflow path from the air inlet to the air outlet.

Features of the first aspect aerosol-generating system of the present disclosure may be applied to any other aspect of the present disclosure. In particular, the cartridge of the second aspect of the present disclosure may comprise features of the aerosol-generating system described in relation to the first aspect of the disclosure. According to another aspect of the present disclosure, there is provided a method of supplying aerosol-forming substrate to an aerosol-generating element in an aerosol-generating system. The system may comprise a storage compartment containing aerosol-forming substrate, and a retention material proximate to the aerosol-generating element suitable for retaining the aerosol-forming substrate. The system may further comprise an aerosol-forming substrate flow path defined between the storage compartment and the retention material, a ferromagnetic body situated in the flow path, and an electromagnet. The method may comprise supplying power to the electromagnet to move the ferromagnetic body between a first position and a second position, wherein in the first position the ferromagnetic body may restrict flow of aerosol-forming substrate to the retention material to a greater degree than in the second position.

The method may comprise moving the ferromagnetic body between the first position and second position a predetermined number of times in response to a user input.

The user input may comprise a user pressing a button. The user input may comprise a user applying a negative pressure to an air outlet of an airflow path defined from an air inlet to an air outlet in the aerosol-generating system.

The method may comprise sequentially increasing and decreasing power supplied to the electromagnet a predetermined number of times. The method may comprise sequentially supplying and cutting power supplied to the electromagnet a predetermined number of times.

The predetermined number of times may be two, three, four, five, six, seven, eight, nine or ten times.

The method may comprise receiving a second user input. The second user input may comprise a user pressing a button. The method may further comprise, in response to the second user input, cutting power to the electromagnet.

As used herein, the term “aerosol” refers to a dispersion of solid particles, or liquid droplets, or a combination of solid particles and liquid droplets, in a gas. The aerosol may be visible or invisible. The aerosol may include vapours of substances that are ordinarily liquid or solid at room temperature as well as solid particles, or liquid droplets, or a combination of solid particles and liquid droplets.

As used herein with reference to the present invention, an aerosol-forming substrate is a substrate capable of releasing volatile compounds that can form an aerosol. Volatile compounds may be released by heating or combusting the aerosol-forming substrate. Volatile compounds may be released by moving the aerosol-forming substrate through passages of a vibratable element. The aerosol forming substrate may comprise both liquid and solid components.

The aerosol-forming substrate may comprise one or more aerosol-formers. An aerosolformer is any suitable known compound or mixture of compounds that, in use, facilitates formation of a dense and stable aerosol and that is substantially resistant to thermal degradation at the temperature of operation of the system. Examples of suitable aerosol formers include glycerine and propylene glycol. Suitable aerosol-formers are well known in the art and include, but are not limited to: polyhydric alcohols, such as triethylene glycol, 1 ,3-butanediol and glycerine; 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. The liquid aerosol-forming substrate may comprise water, solvents, ethanol, plant extracts and natural or artificial flavours. The liquid aerosol-forming substrate may comprise nicotine and at least one aerosol former. The aerosol former may be glycerine or propylene glycol. The aerosol former may comprise both glycerine and propylene glycol. The liquid aerosol-forming substrate may have a nicotine concentration of between about 0.5% and about 10%, for example about 2%.

The aerosol-forming substrate may comprise nicotine. The nicotine containing aerosolforming substrate may be a nicotine salt matrix. The liquid aerosol-forming substrate may comprise plant-based material. The aerosol-forming substrate may comprise tobacco. The aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavour compounds, which are released from the aerosol-forming substrate upon heating. The aerosol-forming substrate may comprise homogenised tobacco material. The aerosolforming substrate may comprise a non-tobacco-containing material. The aerosol-forming substrate may comprise homogenised plant-based material. The aerosol-forming substrate may comprise other additives and ingredients, such as flavourants.

As used herein, the term “liquid aerosol-forming substrate” is used to refer to an aerosolforming substrate in condensed form. Thus, the “liquid aerosol-forming substrate” may be, or may comprise, one or more of a liquid, gel, or paste. If the liquid aerosol-forming substrate is, or comprises, a gel or paste, the gel or paste may liquidise upon heating. For example, the gel or paste may liquidise upon heating to a temperature of less than 50, 75, 100, 150, or 200 degrees Celsius.

As used herein, the term “ferromagnetic” is used to refer to a material that is able to interact with a magnetic field, including both ferromagnetic and ferromagnetic materials.

As used herein the term “diameter” refers to a straight line that passes through the centre of a circle, sphere or circular cross-section of a cylinder, wherein the lines endpoints lie of the circumference of the circle, sphere or circular cross-section of the cylinder.

Below there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

EX1 . An aerosol-generating system comprising: a storage compartment containing an aerosol-forming substrate; a retention material suitable for retaining the aerosol-forming substrate; an aerosol-generating element proximate to the retention material; an aerosol-forming substrate flow path defined between the storage compartment and the retention material, a ferromagnetic body positioned in the flow path; and an electromagnet; wherein application of power to the electromagnet moves the ferromagnetic body between a first position and a second position, wherein in the first position the ferromagnetic body restricts flow of aerosol-forming substrate to the retention material to a greater degree than in the second position.

EX2. An aerosol-generating system according to EX1 , wherein the flow path comprises a first internal diameter and second internal diameter greater than the first internal diameter.

EX3. An aerosol-generating system according to EX2, wherein in the first position the ferromagnetic body is aligned with the first internal diameter and in the second position the ferromagnetic body is aligned with the second internal diameter.

EX4. An aerosol-generating system according to EX2 or EX3, wherein a diameter of the ferromagnetic body is equal to or greater than the first internal diameter of the flow path.

EX5. An aerosol-generating system according to any of EX2 to EX4, wherein an internal surface of the flow path is defined by a surrounding wall or walls forming the first internal diameter and the second internal diameter.

EX6. An aerosol-generating system according to EX5, wherein the surrounding wall or walls comprise a taper.

EX7. An aerosol-generating system according to EX6, wherein the surrounding wall or walls are tapered from the second internal diameter to the first internal diameter.

EX8. An aerosol-generating system according to EX6 or EX7, wherein the surrounding wall or walls have a frusto-conical shape.

EX9. An aerosol-generating system according to any of EX5 to EX8, wherein the surrounding wall or walls comprise a groove or grooves at the second internal diameter.

EX10. An aerosol-generating system according to any of EX2 to EX9, wherein the flow path comprises a fluid bypass channel at the second internal diameter.

EX1 1. An aerosol-generating system according any of EX2 to EX10, wherein the first internal diameter is defined at an end of the flow path adjacent to the retention material.

EX12. An aerosol-generating system according any of EX1 to EX11 , wherein the electromagnet is configured to attract the ferromagnetic body to the first position.

EX13. An aerosol-generating system according any of EX1 to EX11 , wherein the electromagnet is configured to attract the ferromagnetic body to the second position. EX14. An aerosol-generating system according to any Of EX1 to EX13, wherein the electromagnet is ring-shaped.

EX15. An aerosol-generating system according to any of EX1 to EX14, wherein the electromagnet surrounds an end of the flow path.

EX16. An aerosol-generating system according

any i of EX1 to EX15, wherein the electromagnet is positioned adjacent to the retention material.

EX17. An aerosol-generating system according to any

EX1 to EX15, wherein the electromagnet is positioned adjacent to the storage compartment.

EX18. An aerosol-generating system according to any of EX1 to EX17, further comprising a permanent magnet configured to attract the ferromagnetic body.

EX19. An aerosol-generating system according to EX18, wherein the permanent magnet is ring-shaped.

EX20. An aerosol-generating system according to EX18 or EX19, wherein the permanent magnet surrounds the flow path.

EX21. An aerosol-generating system according to any of EX18 to EX20, wherein the permanent magnet is positioned at an end of the flow path.

EX22. An aerosol-generating system according to any of EX18 to EX21 , wherein the permanent magnet is positioned adjacent to the retention material.

EX23. An aerosol-generating system according to any of EX18 to EX21 , wherein the permanent magnet is positioned adjacent to the storage compartment

EX24. An aerosol-generating system according to any of EX18 to EX23, wherein the permanent magnet is configured to attract the ferromagnetic body to the first position.

EX25. An aerosol-generating system according to any of EX18 to EX23, wherein the permanent magnet is configured to attract the ferromagnetic body to the second position.

EX26. An aerosol-generating system according to EX24, wherein when no power is applied to the electromagnet, the ferromagnetic body is attracted to the first position.

EX27. An aerosol-generating system according to EX25, wherein when power is applied to the electromagnet, the ferromagnetic body is attracted to the second position.

EX28. An aerosol-generating system according to any of EX1 to EX17, further comprising a spring.

EX29. An aerosol-generating system according to EX28, wherein the spring is resiliently biased to maintain the ferromagnetic body in the second position.

EX30. An aerosol-generating system according to EX29, wherein when power is applied to the electromagnet, the ferromagnetic body is attracted to the first position overcoming the resilient bias of the spring. EX31 . An aerosol-generating system according to EX28, wherein the spring is resiliently biased to hold the ferromagnetic body in the first position.

EX32. An aerosol-generating system according to any of EX31 , wherein when power is applied to the electromagnet, the ferromagnetic body is attracted to the second position overcoming the resilient bias of the spring.

EX33. An aerosol-generating system according to any of EX1 to EX32, wherein the ferromagnetic body is a sphere.

EX34. An aerosol-generating system according to any of EX1 to EX32, wherein the ferromagnetic body is a disk.

EX35. An aerosol-generating system according to any of EX1 to EX34, wherein the ferromagnetic body comprises stainless steel.

EX36. An aerosol-generating system according to any of EX1 to EX35, wherein the aerosol-generating element is a heating element.

EX37. An aerosol-generating system according to EX36, wherein the aerosol-generating element is a mesh heating element.

EX38. An aerosol-generating system according to any of EX1 to EX37, wherein the retention material comprises a capillary material.

EX39. An aerosol-generating system according to any of EX1 to EX38, wherein the retention material has a fibrous structure.

EX40. An aerosol-generating system according to any of EX1 to EX39, wherein the aerosol-forming substrate is a liquid.

EX41 . An aerosol-generating system according to any of EX1 to EX40, further comprising electrical contacts configured to deliver power to the electromagnet and the aerosol-generating element.

EX42. An aerosol-generating system according to any of EX1 to EX41 , further comprising control electronics configured to control the application of power to the electromagnet and the movement of the ferromagnetic body.

EX43. An aerosol-generating system according to EX42, wherein the control electronics are configured to control supply of power to the aerosol-generating element.

EX44. An aerosol-generating system according to EX42 or EX43, wherein the control electronics comprise a first controller configured to control the application of power to the electromagnet.

EX45. An aerosol-generating system according to EX44, wherein the control electronics comprise a second controller configured to control supply of power to the aerosol-generating element. EX46. An aerosol-generating system according to EX42 or 43, wherein the control electronics comprise a controller configured to control the supply of power to both the electromagnet and the aerosol-generating element.

EX47. An aerosol-generating system according to any of EX42 to EX46, wherein the control electronics are configured to move the ferromagnetic body between the first and the second position.

EX48. An aerosol-generating system according to EX47, wherein the control electronics are configured to move the ferromagnetic body between the first position and the second position a predetermined number of times in response to a user input.

EX49. An aerosol-generating system according to any of EX42 to EX48, wherein the control electronics are configured to sequentially supply and cut power supplied to the electromagnet a predetermined number of times

EX50. An aerosol-generating system according to EX48 or EX49, wherein the control electronics are configured to move the ferromagnetic body between the first position and the second position five times.

EX51. An aerosol-generating system according to any of EX42 to EX50, wherein the control electronics are configured to control the movement of the ferromagnetic body when the aerosol-generating element is not activated.

EX52. An aerosol-generating system according to EX51 , wherein the control electronics are configured to control the movement of the ferromagnetic body before the aerosol-generating element is activated.

EX53. An aerosol-generating system according to any of EX42 to EX50, wherein the control electronics are configured to control the movement of the ferromagnetic body when the aerosol-generating element is activated.

EX54. An aerosol-generating system according to any of EX1 to EX53, further comprising an air inlet, an air outlet and an airflow path from the air inlet to the air outlet.

EX55. An aerosol-generating system according to EX54, wherein the aerosol-generating element is configured to be activated by airflow through the airflow path.

EX56. An aerosol-generating system according to EX55, further comprising an airflow sensor configured to detect air flow through the airflow path and activate the aerosol-generating element.

EX57. An aerosol-generating system according to any of EX54 to EX56 further comprising a mouthpiece configured to allow a user to apply a negative pressure to the mouthpiece and draw air through the airflow path.

EX58. An aerosol-generating system according to any of EX1 to EX57, further comprising a power supply. EX59. An aerosol-generating system according to any of EX1 to EX58, further comprising a net between the aerosol-forming substrate flow path and the retention material.

EX60. An aerosol-generating system according to any of EX1 to EX59 comprising a cartridge and a device.

EX61. An aerosol-generating system according to EX60, wherein the cartridge is removably coupled to the device.

EX62. An aerosol-generating system according to EX60 or EX61 , wherein the cartridge comprises the storage compartment, the retention material, the aerosol-generating element, the aerosol-forming substrate flow path, the ferromagnetic body and the electromagnet.

EX63. An aerosol-generating system according to any of EX60 to EX62, wherein the device comprises a power supply and control electronics.

EX64. An aerosol-generating system according any of EX60 to EX63, wherein the cartridge comprises first electrical contacts configured to deliver power to the electromagnet.

EX65. An aerosol-generating system according to any of EX60 to EX64, wherein the device comprises second electrical contacts configured.

EX66. A cartridge for an aerosol-generating system, the cartridge comprising: a storage compartment for containing an aerosol-forming substrate; an electromagnet; electrical contacts configured to receive power from a power supply and deliver power to the electromagnet; an aerosol-forming substrate flow path configured to transport aerosol-forming substrate from the storage compartment to an aerosol-forming substrate outlet; and a ferromagnetic body situated in the flow path; wherein application of power to the electromagnet moves the ferromagnetic body between a first position and a second position, wherein in the first position the ferromagnetic body restricts flow of aerosol-forming substrate to the aerosol-forming substrate outlet to a greater degree than in the second position.

EX67. A cartridge according to EX66, further comprising an aerosol-generating element.

EX68. A cartridge according to EX67, further comprising a retention material situated between the aerosol-generating element and the substrate outlet.

EX69. A cartridge according to EX66 or EX68, wherein the flow path comprises a first internal diameter and second internal diameter greater than the first internal diameter.

EX70. A cartridge according to EX69 wherein in the first position the ferromagnetic body is aligned with the first internal diameter and in the second position the ferromagnetic body is aligned with the second internal diameter. EX71 . A cartridge according to EX69 or EX70, wherein a diameter of the ferromagnetic body is equal to or greater than the first internal diameter of the flow path.

EX72. A cartridge according to any of EX69 to EX70, wherein an internal surface of the flow path is defined by a surrounding wall or walls forming the first internal diameter and the second internal diameter.

EX73. A cartridge according to EX72, wherein the surrounding wall or walls comprise a taper.

EX74. A cartridge according to EX73, wherein the surrounding wall or walls are tapered from the second internal diameter to the first internal diameter.

EX75. A cartridge according to EX73 or EX74, wherein the surrounding wall or walls have a frusto-conical shape.

EX76. A cartridge according to any of EX72 to EX75, wherein the surrounding wall or walls comprise a groove or grooves at the second internal diameter.

EX77. A cartridge according to any of EX72 to EX76, the flow path comprises a fluid bypass channel at the second internal diameter.

EX78. A cartridge according to any of EX66 to EX77, wherein the electromagnet surrounds an end of the flow path.

EX79. A cartridge according any of EX66 to EX78, wherein the electromagnet is configured to attract the ferromagnetic body to the first position.

EX80. A cartridge according any of EX66 to EX78, wherein the electromagnet is configured to attract the ferromagnetic body to the second position.

EX81. A cartridge according to any of EX66 to EX80, further comprising a permanent magnet configured to attract the ferromagnetic body.

EX82. A cartridge according to EX81 , wherein the permanent magnet is configured to attract the ferromagnetic body to the first position.

EX83. A cartridge according to any of EX66 to EX80, further comprising a spring.

EX84. A cartridge according to EX83, wherein when power is applied to the electromagnet, the ferromagnetic body is attracted to the first position overcoming the resilient bias of the spring.

EX85. A cartridge according to EX84, wherein the ferromagnetic body is a sphere comprising stainless steel.

EX86. A cartridge according to any of EX66 to EX85, further comprising an air inlet, an air outlet and an airflow path from the air inlet to the air outlet.

EX87. A method of supplying aerosol-forming substrate to an aerosol-generating element in an aerosol-generating system, the system comprising: a storage compartment containing aerosol-forming substrate; a retention material proximate to the aerosol-generating element suitable for retaining the aerosol-forming substrate; an aerosol-forming substrate flow path defined between the storage compartment and the retention material; a ferromagnetic body situated in the flow path; and an electromagnet; the method comprising: supplying power to the electromagnet to move the ferromagnetic body between a first position and a second position, wherein in the first position the ferromagnetic body restricts flow of aerosol-forming substrate to the retention material to a greater degree than in the second position.

EX88. A method according to EX87, comprising moving the ferromagnetic body between the first position and second position a predetermined number of times in response to a user input.

EX89. A method according to EX88, wherein the user input comprises a user pressing a button.

EX90. A method according to EX88 or EX89, wherein the user input comprises a user applying a negative pressure to an air outlet of an airflow path defined from an air inlet to an air outlet in the aerosol-generating system.

EX91. A method according to any of EX88 to EX90, further comprising sequentially increasing and decreasing power supplied to the electromagnet a predetermined number of times.

EX92. A method according to EX91 , comprising sequentially supplying and cutting power supplied to the electromagnet a predetermined number of times.

EX93. A method according to any of EX88 to EX91 , wherein the predetermined number of times is two, three, four, five, six, seven, eight, nine, or ten times.

Examples will now be further described with reference to the figures in which:

Figure 1 shows a schematic illustration of an aerosol-generating system according to a first embodiment of the present disclosure;

Figure 2a shows a schematic illustration of a portion of a cartridge according to the first embodiment of the present disclosure;

Figure 2b shows a schematic illustration of a portion of a cartridge according to the first embodiment of the present disclosure;

Figure 3 shows a schematic illustration of an aerosol-generating system according to a second embodiment of the present disclosure;

Figure 4a shows a schematic illustration of a portion of an aerosol-generating system according to a third embodiment of the present disclosure;

Figure 4b shows a schematic illustration of a portion of the aerosol-generating system according to the third embodiment of the present disclosure; Figure 5a shows a schematic illustration of a portion of an aerosol-generating system according to a fourth embodiment of the present disclosure;

Figure 5b shows a schematic illustration of a portion of the aerosol-generating system according to the fourth embodiment of the present disclosure;

Figure 6a shows a schematic illustration of a portion of an aerosol-generating system according to a fifth embodiment of the present disclosure;

Figure 6b shows a schematic illustration of a portion of the aerosol-generating system according to the fifth embodiment of the present disclosure;

Figure 7a shows a schematic illustration of a portion of an aerosol-generating system according to a sixth embodiment of the present disclosure;

Figure 7b shows a schematic illustration of a portion of the aerosol-generating system according to the sixth embodiment of the present disclosure

Figure 8a shows a schematic illustration of a portion of an aerosol-generating system according to a seventh embodiment of the present disclosure;

Figure 8b shows a schematic illustration of a portion of the aerosol-generating system according to the seventh embodiment of the present disclosure; and

Figure 9 shows a flow chart of a method of supplying aerosol-forming substrate to an aerosol-generating element in an aerosol-generating system of the present disclosure.

Figure 1 is a schematic illustration of an aerosol-generating system according to a first embodiment of the present disclosure. The system comprises a cartridge 100 and a device 200, which are detachably coupled together to form the aerosol-generating system. The aerosolgenerating system is portable and has a size comparable to a conventional cigar or cigarette. The cartridge 100 comprises a storage compartment 105 containing aerosol-forming substrate. The aerosol-forming substrate in this example is a liquid. The retention material 115 is suitable for retaining the aerosol-forming substrate. The retention material is a capillary material with a fibrous structure. An aerosol-generating element 125 is located proximate to the retention material 115. The aerosol-generating 125 element is a mesh heating element. There is an aerosol-forming substrate flow path 110 defined between the storage compartment 105 and the retention material 1 15. A net 1 18 is positioned between the retention material 1 15 and the aerosol-forming substrate flow path 1 10. A ferromagnetic body 120, such as a stainless steel ball, is positioned in the flow path 110. The aerosol-generating system comprises an electromagnet 130, which is positioned upstream of the ferromagnetic body 120, as shown in Figure 1 . Alternatively, the electromagnet may be positioned downstream of the ferromagnetic body 120. The aerosol-generating system 300 further comprises a permanent magnet 160. The permanent magnet is configured to attract the ferromagnetic body 120 to the first position. The cartridge 100 comprises electrical contacts (not shown) configured to electrically connect the aerosol-generating element 125 and the electromagnet 130 to electrical contacts of the device 200.

The device 200 comprises a power supply 220 and control electronics 240, configured to supply power to the aerosol-generating element 125 and the electromagnet 130. The control electronics 240 and power supply 220 are electrically connected to the aerosol-generating element 125 and the electromagnet 130 via electrical contacts on the device 200, the electrical contacts are not shown in Figure 1 . The electrical contacts on the device 200 may be configured to be in electrical contact with electrical contacts on the cartridge 100, when the device 200 is attached to the cartridge 100.

Application of power to the electromagnet 130 moves the ferromagnetic body 120 between a first position and a second position. In the first position, as shown in Figure 1 , the ferromagnetic body 120 restricts flow of aerosol-forming substrate to the retention material 115 to a greater degree than in the second position.

As shown in Figure 1 , the flow path comprises a first internal diameter 135 and second internal diameter 140 greater than the first internal diameter 135. The ferromagnetic body 120, a sphere comprising stainless steel in this example, is shown in the first position where it is aligned with the first internal diameter 135 of the flow path. An internal surface of the flow path is defined by a surrounding wall forming the first 135 and second 140 internal diameters. As shown in Figure 1 , the surrounding wall is tapered from the second internal diameter 140 to the first internal diameter 135, with a frusto-conical shape. The first internal diameter 135 is defined at an end of the flow path adjacent to the retention material 115. The permanent magnet 160 is ring-shaped and surrounds the end of the flow path adjacent to the retention material 1 15. The permanent magnet is configured to attract the ferromagnetic body 120 to the first position. When power is applied to the electromagnet 130, the ferromagnetic body 120 is attracted to the second position, where the ferromagnetic body restricts the flow of aerosol-forming substrate to a lesser degree than in the first position.

The aerosol-generating system 300 comprises an air inlet 145, an air outlet 150 and an airflow path defined between the air inlet 145 and the air inlet 150.

When not in use, and when no power is applied to the electromagnet 130, the ferromagnetic body 120 is in the first position, as it is attracted by the permanent magnet 160. In use, a user puffs on the air outlet 150 of the system 300. At the same time, the user presses a button (not shown) on the aerosol-generating device 200. Pressing this button sends a signal to the control electronics 240, which results in power being supplied from the battery 220 to the aerosolgenerating element 125 via the electrical contacts of the device and the electrical contacts of the cartridge. This causes a current to flow through the heating element 125, thereby resistively heating the aerosol-generating element 125. The electrical contacts of the cartridge are configured to supply power to both the aerosol-generating element 125 and the electromagnet 130. When power is applied to the electromagnet 130 the magnetic force of the electromagnet 130 is configured to attract the ferromagnetic body 120 to the second position. In other examples, an air flow sensor, or pressure sensor, is located in the cartridge 200 and electrically connected to the controller 240. The air flow sensor, or pressure sensor, detects that a user is puffing on the air outlet 150 of the system 300 and sends a signal to the control electronics 240 to provide power to the heating element 125 and the electromagnet 130. In these examples, there is therefore no need for the user to press a button to heat the heating element 125.

As the user puffs on the air outlet 150 of the system 300, air is drawn into the air inlet 145. This air then travels through the airflow path. This air travels across a surface of the aerosolgenerating element 125 and towards the air outlet 150. The flow of air entrains vapour formed by the heating element 125 heating the aerosol-forming substrate. This entrained vapour then cools and condenses to form an aerosol. This aerosol is then delivered to the user via the air outlet 150. As aerosol-forming substrate in the retention material 1 15 is heated, vaporised, and entrained in the air flow.

Aerosol-forming substrate from the storage compartment 105 travels via the aerosolforming substrate flow path 1 10, through the net 1 18, to the retention material 1 15 when the ferromagnetic body 120 is in the second position. This aerosol-forming substrate from the storage compartment 105 effectively replaces the vaporised aerosol-forming substrate. The aerosolforming substrate from the storage compartment may be drawn into the retention material 1 15, at least partly, by capillary action. This is because the retention material 115 is a capillary material having a fibrous or spongy structure. The aerosol-forming substrate may further be transported from the storage compartment 105 to the retention material 115 by movement of the ferromagnetic body. The control electronics 240 are configured to control application of power to the electromagnet. In response a to user input, for example the user pressing a button the control electronics 240 are configured to sequentially increase and reduce the amount of power to supplied to the electromagnet 130, thereby moving the ferromagnetic body 120 back and forth in the aerosol-forming substrate flow channel. This back and forth movement creates a pumping effect to increase the supply of aerosol-forming substrate to the retention material 115.

Figures 2a and 2b shows a schematic illustration of a portion of a cartridge according to the first embodiment of the present disclosure. The portion of the aerosol-generating systems shown in Figures 2a and 2b comprise the permanent magnet 160, the electromagnet 130, the ferromagnetic body 120, and the aerosol-forming substrate flow path 1 10, the retention material 115, the storage portion 105 and the aerosol generating element 125. Figure 2a shows the ferromagnetic body 120 is the second position. Figure 2b shows the ferromagnetic body 120 in the first position. In Figures 2a and 2b the electromagnet 130 is configured to attract the ferromagnetic body 120 to the second position. The portion of the aerosol-generating system as shown in Figures 2a and 2b comprises a permanent magnet 160 configured to attract the ferromagnetic body 120 to the first position. Figure 2a shows the embodiment when power is being applied to the electromagnet 130. Figure 2b shows the embodiment when no power is being applied to the electromagnet 130.

Figure 3 shows a schematic illustration of an aerosol-generating system according to a second embodiment of the present disclosure. Many features of this embodiment are the same as described for Figure 3. The difference between the system of Figure 1 and the system of Figure 3 is the arrangement of electromagnet 430 and the permanent magnet 460. As shown in Figure 3, the permanent magnet 460 is configured to attract the ferromagnetic body 420 to a second position. When power is applied to the electromagnet 430, the electromagnet is configured to attract the ferromagnetic body to the first position. The electromagnet 230 is configured to attract the ferromagnetic body 420 to the first position. When no power is applied to the electromagnet 430, the ferromagnetic body 420 is attracted to the second position.

Figures 4a and 4b show a schematic illustration of a portion of an aerosol-generating system according to a third embodiment of the present disclosure. The portion is interchangeable with the portion shown in Figure 2a and 2b and may be part of a cartridge of an aerosol-generating system, such as the systems shown in Figures 1 or 3. The embodiment as shown in Figures 4a and 4b does not comprise a permanent magnet, but does comprise a spring 770. In Figure 4a the spring 770 is extended. In Figure 4b the spring 770 is compressed.

The spring as shown in Figures 4a and 4b is resiliently biased to maintain the ferromagnetic body 720 in the second position. The resilient bias of the spring 770 may be sufficient to hold the ferromagnetic body 720 in the second position when the system is held at any orientation. When power is applied to the electromagnet 730, the ferromagnetic body 720 is attracted to the first position overcoming the resilient bias of the spring 770, and the spring is compressed as shown in Figure 4b. The resilient bias of the spring 770 has less strength than the attractive force of the electromagnet 730 on the ferromagnetic body.

Figure 5a shows a schematic illustration of a portion of an aerosol-generating system according to a fourth embodiment of the present disclosure. The embodiment shown in Figure 5a comprises a spring 870. In Figure 5a the spring is compressed. The electromagnet 830 is configured to attract the ferromagnetic body 820 to the second position. Figure 5a shows the embodiment when power is being applied to the electromagnet.

Figure 5b shows the fourth embodiment, when the spring 870 is extended. The spring 870 is resiliently biased to hold the ferromagnetic body 820 in the first position. The electromagnet 830 is configured to attract the ferromagnetic body 820 to the second position. Figure 5b shows the embodiment when power is not being applied to the electromagnet 830. When power is applied to the electromagnet 830, the ferromagnetic body 820 is attracted to the second position overcoming the resilient bias of the spring 870.

Figure 6a shows a schematic illustration of a portion of an aerosol-generating system according to a fifth embodiment of the present disclosure. As shown in Figure 6a the aerosolforming substrate flow path 910 comprises surrounding wall, which comprises a groove 912 at the second internal diameter. The groove provides a region of increased internal diameter of the flow path, allowing liquid to pass the ferromagnetic body. As shown in Figure 6a the ferromagnetic body 920 is in the second position, when power is not being applied to the electromagnet 930.

Figure 6b shows a schematic illustration of a portion of the aerosol-generating system according to the fifth embodiment of the present disclosure. In Figure 6a the surrounding wall comprises a groove at the second internal diameter and the ferromagnetic body 920 is in the first position, when power is applied to the electromagnet 930.

Figure 7a shows a schematic illustration of a portion of an aerosol-generating system according to a sixth embodiment of the present disclosure. The surrounding wall comprises a groove and a taper. The ferromagnetic body is in the second position.

Figure 7b shows a schematic illustration of a portion of the aerosol-generating system according to the sixth embodiment of the present disclosure. The surrounding wall comprises a groove and a taper. The ferromagnetic body is in the first position.

Figures 8a and 8b show a schematic illustration of a portion of an aerosol-generating system according to a seventh embodiment of the present disclosure. The electromagnet 1 130 is positioned adjacent to the retention material 1 115 and is configured to attract the electromagnetic body 1 120 to the second position. The permanent magnet 1160 is configured to attract the ferromagnetic 1 120 body to the first position. The surrounding walls of the aerosol-forming substrate flow path comprise a taper. The taper has a frusto-conical shape and comprises a first diameter and a second diameter, where the first diameter is smaller than the second diameter. As shown in Figures 8a and 8b the permanent magnet 1160 is adjacent to the first diameter and adjacent to the storage compartment 1105. Figure 8a shows the ferromagnetic body 1120 in the second position. Figure 8b shows the ferromagnetic body 1120 in the first position.

Figure 9 shows a flow chart of a method of supplying aerosol-forming substrate to an aerosol-generating element in an aerosol-generating system of the present disclosure. The method comprises receiving a user input 10. The user input in this example comprises a user pressing a button. Then, the method comprises the step of supplying power to an electromagnet in step 20 to move a ferromagnetic body between the first position and the second position in response to the user input. In the first position, the ferromagnetic body restricts flow of aerosolforming substrate to the retention material to a greater degree than in the second position. The method further comprises sequentially increasing and decreasing power supplied to the electromagnet a predetermined number of times in step 30, at least five times for example. The method then comprises the step 40 of receiving a second user input and, in response to the second user input, in step 50 cutting power to the electromagnet.

For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ± 10 percent of A.

Claims

25 CLAIMS

1 . An aerosol-generating system comprising: a storage compartment containing an aerosol-forming substrate; a retention material suitable for retaining the aerosol-forming substrate; an aerosol generating element proximate to the retention material; an aerosol-forming substrate flow path defined between the storage compartment and the retention material, wherein the flow path comprises a first internal diameter and second internal diameter that is greater than the first internal diameter; a ferromagnetic body positioned in the flow path; and an electromagnet; wherein application of power to the electromagnet moves the ferromagnetic body between a first position and a second position, wherein in the first position the ferromagnetic body restricts flow of aerosol-forming substrate to the retention material to a greater degree than in the second position, and wherein in the first position the ferromagnetic body is aligned with the first internal diameter and in the second position the ferromagnetic body is aligned with the second internal diameter.

2. An aerosol-generating system according to claim 1 , wherein a diameter of the ferromagnetic body is equal to or greater than the first internal diameter of the flow path.

3. An aerosol-generating system according to claim 1 or 2, wherein an internal surface of the flow path is defined by a surrounding wall or walls forming the first internal diameter and the second internal diameter.

4. An aerosol-generating system according to any preceding claim, wherein the surrounding wall or walls are tapered from the second internal diameter to the first internal diameter.

5. An aerosol-generating system according to any preceding claim, wherein the surrounding wall or walls comprise a groove or grooves at the second internal diameter.

6. An aerosol-generating system according to any preceding claim, wherein the electromagnet surrounds an end of the flow path.

7. An aerosol-generating system according to any preceding claim, further comprising a permanent magnet configured to attract the ferromagnetic body to the first position.

8. An aerosol-generating system according to claim 7, wherein when power is applied to the electromagnet, the ferromagnetic body is attracted to the second position.

9. An aerosol-generating system according to any preceding claim further comprising a spring.

10. An aerosol-generating system according to claim 9, wherein when power is applied to the electromagnet, the ferromagnetic body is attracted to the first position overcoming the resilient bias of the spring.

11. An aerosol-generating system according to any preceding claim, wherein the ferromagnetic body is a sphere comprising stainless steel.

12. An aerosol-generating system according to any preceding claim, further comprising control electronics configured to control the application of power to the electromagnet and the movement of the ferromagnetic body.

13. An aerosol-generating system according to any preceding claim, further comprising a net between the aerosol-forming substrate flow path and the retention material.

14. A method of supplying aerosol-forming substrate to an aerosol-generating element in an aerosol-generating system, the system comprising: a storage compartment containing aerosolforming substrate; a retention material proximate to the aerosol-generating element suitable for retaining the aerosol-forming substrate; an aerosol-forming substrate flow path defined between the storage compartment and the retention material wherein the flow path comprises a first internal diameter and second internal diameter that is greater than the first internal diameter; a ferromagnetic body situated in the flow path; and an electromagnet; the method comprising: supplying power to the electromagnet to move the ferromagnetic body between a first position and a second position, wherein in the first position the ferromagnetic body restricts flow of aerosol-forming substrate to the retention material to a greater degree than in the second position, and wherein in the first position the ferromagnetic body is aligned with the first internal diameter and in the second position the ferromagnetic body is aligned with the second internal diameter.