RU2800111C2 - Aerosol generating device having capacitance-based power control - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to an aerosol generating device. The controller of the aerosol generating device is additionally configured to: measure the capacitance of the capacitor by means of the first and second electrodes when the aerosol generating device is placed inside the cavity; supplying power from the power supply to at least one heater in the first power profile when the measured capacitance is within a predetermined first range; and supplying power from the power supply to at least one heater in a second power profile different from the first power profile when the measured capacitance is within a predetermined second range.

EFFECT: monitoring the amount of water present in the aerosol-forming substrate before heating the aerosol-forming substrate.

25 cl, 12 dwg

Description

The present invention relates to aerosol generating systems comprising an aerosol generating substrate configured to be positioned between electrodes such that the aerosol generating substrate and the electrodes form a capacitor. The present invention also relates to aerosol generating devices comprising electrodes spaced apart such that an aerosol generating substrate can be positioned between the electrodes to form a capacitor.

One type of aerosol generating system is an electric smoking system. Known hand-held electric smoking systems typically comprise an aerosol generating device comprising a battery, control electronics, and an electrical heater for heating an aerosol generating article made specifically for use with an aerosol generating device. In some examples, the aerosol-generating article comprises an aerosol-generating substrate, such as a tobacco rod or tobacco extrusion, and a heater enclosed within the aerosol-generating device is inserted within or around the aerosol-generating substrate when the aerosol-generating article is inserted within the aerosol-generating device.

Typically, the aerosol generating device is configured to generate heat using an electric heater according to a predetermined heating profile. However, variations in the aerosol-forming substrate may result in undesirable variations in user experience. For example, in environments with high humidity, the aerosol-forming substrate may have a high water content. Because water aerosolizes at normal operating temperatures for aerosol generating devices, a high water content can result in the user's perception of the aerosol temperature as undesirably high. In another example, an aerosol-forming substrate that has already been heated may have a low water content. The low water content can result in reduced heat transfer from the aerosol generating substrate if the user tries to reheat the aerosol generating substrate in the aerosol generating device. Reduced heat transfer from the aerosol generating substrate may result in overheating of the aerosol generating device.

It would be desirable to provide an aerosol generating device that reduces or overcomes at least some of the shortcomings of known aerosol generating devices. In particular, it would be desirable to provide an aerosol generating device that monitors the amount of water present in the aerosol generating substrate prior to heating the aerosol generating substrate.

According to a first aspect of the present invention, an aerosol generating system is provided, comprising: an aerosol generating article comprising an aerosol generating substrate, wherein the aerosol generating substrate is a dielectric material; an aerosol generating device; and a first electrode and a second electrode. Preferably, the aerosol-forming substrate is a substantially solid aerosol-forming substrate. The aerosol generating device comprises: a power supply unit; at least one heater; and a cavity for receiving an aerosol generating article. The aerosol generating device further comprises a controller configured to control power supply from the power supply to at least one heater to heat the aerosol generating substrate when the aerosol generating article is placed inside the cavity. The second electrode is located at a distance from the first electrode such that at least a portion of the aerosol generating substrate is placed between the first electrode and the second electrode when the aerosol generating article is placed within the cavity. The first electrode, the aerosol-generating substrate portion, and the second electrode form a capacitor when the aerosol-generating article is placed inside the cavity. The controller of the aerosol generating device is further configured to: measure the capacitance of the capacitor through the first and second electrodes when the aerosol generating article is placed inside the cavity; supplying power from the power supply to at least one heater in the first power profile when the measured capacitance is within a predetermined first range; and supplying power from the power supply to at least one heater in a second power profile different from the first power profile when the measured capacitance is within a predetermined second range.

Preferably, the controller is configured to measure the capacitance of the capacitor formed by the first electrode, the second electrode, and the part of the aerosol-generating substrate located between the first electrode and the second electrode when the aerosol-generating article is placed inside the cavity, and change the power supply to at least one heater based on the measured capacitance.

Advantageously, the capacitance measured may indicate the amount of water present in the aerosol forming substrate between the first electrode and the second electrode. A relatively high measured capacitance may indicate a relatively high water content. A relatively low measured capacitance may indicate a relatively low water content. The controller changes the power supply to at least one heater based on the measured capacitance. Advantageously, changing the power supply to the at least one heater based on the measured capacitance may allow the system to generate an aerosol having uniform properties.

Determining the capacitance of an aerosol generating substrate is known in aerosol generating systems. For example, see publications of international patent applications under the numbers: WO 2017/051006 A1, WO 2017/051011 A1; and WO 2017/051016 A1 issued to Philip Morris Products S.A. In these publications, capacitance measurements of a capacitor containing an aerosol-forming substrate between two electrodes are used to provide an indication of the amount of one or more volatile compounds in the aerosol-forming substrate. This information is then used to determine when one or more volatile compounds of the aerosol-forming substrate is depleted and to stop heating the substrate when one or more volatile compounds have been depleted.

The present inventors have realized that determining the capacitance of the aerosol generating substrate can also be used to control the power applied to the heater, to improve the uniformity of the properties of the aerosol generated from the aerosol generating substrate and in turn improve the user experience.

The water content of the aerosol-generating substrate can affect the water vapor content of the aerosol generated from the substrate. In particular, an increase in the water content of the aerosol-generating substrate may lead to an increase in the water vapor content of the aerosol generated from the substrate. The water vapor content of the aerosol can affect the apparent temperature of the aerosol, which is the temperature of the aerosol as perceived by the user. Generally, an increase in the water vapor content of an aerosol results in an increase in the apparent temperature of the aerosol. Accordingly, it is generally desirable to keep the water content of the aerosol-forming substrate at a constant level. However, the water content of the aerosol generating substrate can be affected by several factors such as the method of storage of the aerosol generating substrate and the humidity of the environment in which the aerosol generating system is used. As a result, it may be difficult to maintain the water content of the aerosol-forming substrate at a constant level.

The present inventors have recognized that capacitance measurements of a capacitor formed by an aerosol-forming substrate located between a pair of electrodes are particularly sensitive to the presence of water in the aerosol-forming substrate and to changes in the volume fraction of water in the aerosol-forming substrate. The capacitance of a capacitor depends on the relative permeability of the material located between the electrodes of the capacitor. The relative permittivity, or dielectric constant, of a material describes the tendency of a material to polarize in response to an applied electric field. Water generally has a relatively high relative permeability compared to other materials present in the aerosol generating substrate such as tobacco and aerosol generating agents such as propylene glycol. Accordingly, determining the capacity of an aerosol-forming substrate can be particularly effective in providing an indication of the water content of an aerosol-forming substrate and in determining changes in water content of an aerosol-forming substrate.

The present inventors also realized that an indication of the water content of the aerosol generating substrate provided by measurements of the capacity of the substrate can be used to control the temperature of the aerosol generated from the substrate by controlling the temperature of the heater heating the substrate to generate the aerosol. Controlling the temperature of the heater heating the aerosol generating substrate can be achieved by controlling the power supply to the heater based on capacitance measurements. Accordingly, controlling the power supply to the heater heating the aerosol-generating substrate based on measurements of the capacitance of the aerosol-generating substrate can allow the aerosol-generating system to generate an aerosol with uniform properties.

The aerosol generating device comprises a controller configured to control the power supply from the power supply to at least one heater. In particular, the controller is configured to control the supply of power from the power supply to at least one heater for heating the aerosol generating substrate when the aerosol generating article is placed inside the cavity.

In the context of this document, the term "power" can be used to refer to the instantaneous power supplied to the heater, but is generally used to refer to the actual power, or average power supplied to the heater over a period of time. In particular, when power is supplied to the heater by an alternating voltage or current, the term "power" refers to the actual power supplied to the heater.

The controller may be configured to control the supply of power from the power supply to the at least one heater in any suitable manner. For example, the controller may be configured to supply power from the power supply to at least one heater continuously after system activation or intermittently, such as from puff to puff.

In some preferred embodiments, the controller may be configured to supply power from the power supply to the electric heater in the form of pulses of electric current. In these preferred embodiments, the controller may be configured to control the power supply to the heater by controlling the power supply duty cycle to the heater. In the context of this document, the term "duty cycle" refers to the relative power output of a power supply compared to the maximum power output of a power supply. So a 70% duty cycle indicates that the power supply is delivering output power that is 70% of the maximum output power that the power supply can supply. The controller may be configured to control the duty cycle by any suitable means. For example, the controller may be configured to control the duty cycle through pulse width modulation.

The controller is configured to supply power from the power supply to at least one heater in accordance with predetermined power profiles. Predefined power profiles may be stored in the controller's memory. The controller may be configured to supply constant power to the heater in accordance with a predetermined power profile. The controller may be configured to supply power to the heater that varies over time in accordance with a predetermined power profile. For example, the controller may be configured to supply first power to the heater for a first predetermined period of time and then supply second power to the heater for a second predetermined period of time in accordance with a predetermined power profile.

The controller of the aerosol generating device is further configured to: measure the capacitance of the capacitor by means of the first electrode and the second electrode when the aerosol generating article is placed inside the cavity. The controller is configured to control the power supply to at least one heater based on the measured capacitance. The controller may be configured to control the power supply to the at least one heater based on the measured capacitance in any suitable manner.

In particular, the controller may be configured to apply a normal power profile to at least one heater when capacity measurements indicate that the water content within the aerosol-forming substrate is within a normal operating level, and to apply a modified power profile to at least one heater when capacity measurements indicate that the water content of the aerosol-forming substrate is above the normal operating level or below the normal operating level.

The controller may be configured to apply a low power profile to at least one heater when capacitance measurements indicate that the water content of the aerosol generating substrate is above a normal operating level. The low power profile can supply lower power to the heater than the normal power profile. Reducing the power applied to the heater to heat the wet aerosol-forming substrate can reduce the temperature of the aerosol generated from the wet aerosol-forming substrate below the temperature of the aerosol generated from the non-wet aerosol-forming substrate heated by the heater to which the normal power profile is applied. This can reduce the perceived temperature of an aerosol generated from a moist aerosol-forming substrate to the normal perceived temperature of an aerosol generated from a non-moist aerosol-forming substrate.

Applying a low power profile to the heater during an initial period of time may allow the heater to remove excess water from the aerosol-forming substrate during the initial period of time, resulting in the water content of the aerosol-forming substrate being within normal operating levels after the initial period of time. Accordingly, the controller may be configured to apply a low power profile to at least one heater for a predetermined initial period of time when capacitance measurements indicate that the water content of the aerosol forming substrate is above a normal operating level, and further configured to apply a normal power profile to the heater after a predetermined initial period of time.

Similarly, in some embodiments, the controller may be configured to apply a high power profile to at least one heater when capacitance measurements indicate that the water content of the aerosol generating substrate is below a normal operating level. The high power profile can deliver higher power to the heater than the normal power profile. Increasing the power supplied to the heater to heat the dry aerosol-forming substrate can increase the temperature of the aerosol generated from the dry aerosol-forming substrate above the temperature of the aerosol generated from the non-dry aerosol-forming substrate heated by the heater to which the normal power profile is applied. This can increase the perceived temperature of an aerosol generated from a dry aerosol-forming substrate to the normal perceived temperature of an aerosol generated from a non-dry aerosol-forming substrate.

The controller may be configured to supply power from the power supply to the heater in discrete power profiles, with each power profile associated with a specific range of measured capacitances. The controller may be configured to supply power from the power supply to the heater in any suitable number of power profiles. The controller may be configured to change the power profile applied to the heater depending on the measured capacitance. The controller may be configured to change the power supply from the power supply to the heater continuously depending on the measured capacitance.

The controller is configured to: supply power from the power supply to at least one heater in the first power profile when the measured capacitance is within a predetermined first range; and supplying power from the power supply to at least one heater in a second power profile different from the first power profile when the measured capacitance is within a predetermined second range.

The predefined ranges may be any suitable range types.

In some embodiments, the predetermined range may be any value that exceeds a predetermined threshold. In some embodiments, the predefined range may be any value that is less than or equal to a predefined threshold. In other words, the predefined range may be an open range.

In some embodiments, the predefined range may be between an upper predefined threshold and a lower predefined threshold. In other words, the predefined range may be a closed range.

In some preferred embodiments, the predefined first range and the predefined second range are consecutive ranges such that the upper limit of one of the ranges is equal to the lower limit of the other of the ranges.

In some embodiments, the predefined first range is an open range and the predefined second range is an open range. In these embodiments, the controller may be configured to: apply power from the power supply to at least one heater in a first power profile when the measured capacitance exceeds a predetermined first threshold; and supplying power from the power supply to at least one heater in a second power profile different from the first power profile when the measured capacitance is less than or equal to a predetermined second threshold value. In some preferred embodiments, the predetermined first threshold is equal to the predetermined second threshold. In these preferred embodiments, the controller is configured to: apply power from the power supply to at least one heater in the first power profile when the measured capacitance exceeds a predetermined threshold value; and supplying power from the power supply to at least one heater in a second power profile different from the first power profile when the measured capacitance is less than or equal to a predetermined threshold value.

In some embodiments, one of the predefined first range and the predefined second range is an open range, and the other of the predefined first range and the predefined second range is a closed range.

In some embodiments, the predefined first range is a closed range and the predefined second range is a closed range. In these embodiments, the controller may be configured to: apply power from the power supply to at least one heater in a first power profile when the measured capacitance is between a predetermined first low threshold and a predetermined first high threshold; and supplying power from the power supply to at least one heater in a second power profile different from the first power profile when the measured capacitance is between a predetermined second lower threshold and a predetermined second upper threshold. In some preferred embodiments, the predetermined first lower threshold is equal to the predetermined second upper threshold. In these preferred embodiments, the controller is configured to: apply power from the power supply to at least one heater in a first power profile when the measured capacitance is between a predetermined middle threshold and a predetermined high threshold; and supplying power from the power supply to at least one heater in a second power profile different from the first power profile when the measured capacitance is between a predetermined lower threshold and a predetermined average threshold.

In some preferred embodiments, the controller is further configured to prevent the supply of power from the power supply to at least one heater based on a capacitance measurement. The controller may be configured to prevent power supply from the power supply to at least one heater based on comparing the capacitance measurement to one or more of a predetermined high threshold and a predetermined low threshold.

The predetermined upper threshold may indicate a maximum allowable water content of the aerosol generating substrate, above which the aerosol generated from the aerosol generating substrate is unacceptable to the user. The controller may be configured to prevent the supply of power from the power supply to the at least one heater when capacitance measurements exceed a predetermined upper threshold.

The predetermined lower threshold may indicate a minimum acceptable water content in the aerosol generating substrate below which the aerosol generated from the aerosol generating substrate is unacceptable to the user. The controller may be configured to prevent the supply of power from the power supply to the at least one heater when the capacitance measurement is below a predetermined lower threshold.

In some embodiments, the controller may be configured to prevent the supply of power from the power supply to at least one heater when the capacitance measurement is outside a predetermined allowable range, wherein the allowable range is defined between a predetermined upper threshold and a predetermined lower threshold.

In some preferred embodiments, the controller is further configured to measure capacitance prior to applying power from the power supply to at least one heater to heat the aerosol generating substrate. One or more capacitance measurements taken prior to powering the at least one aerosol-generating substrate heater can be used to control the initial power applied to the aerosol-generating substrate heater. Advantageously, capacitance measurement prior to energizing the heater to heat the aerosol forming substrate allows control of the power applied to the heater from the beginning of the heating cycle.

In some preferred embodiments, the controller is further configured to periodically measure the capacitance and adjust the power supplied to the heater to heat the aerosol generating substrate at periodic intervals based on the measured capacitance. In other words, the controller may be configured to repeatedly measure the capacitance during the entire heating cycle and adjust the power supplied to the heater during the entire heating cycle based on the most recent capacitance measurement. Advantageously, periodic capacitance measurements throughout the entire heating cycle may allow the aerosol generating system to generate an aerosol with uniform properties throughout the entire heating cycle. The period of time between successive periodic capacitance measurements may be any suitable period of time. For example, the interval between successive periodic capacitance measurements can be from about 0.5 seconds to about 30 seconds, or can be at least about 0.5 seconds, at least about 1 second, at least about 1.5 seconds, or at least about 2 seconds.

In some embodiments, the aerosol generating device includes means for detecting a puff, and in these embodiments, the controller may be configured to measure capacitance when a puff is detected.

In some preferred embodiments, the controller is further configured to determine when an aerosol generating article is placed in the cavity based on the measured capacitance. The controller may be further configured to sequentially supply power from the power supply to at least one heater in one of the first and second power profiles when it is determined that the aerosol generating article is placed in the cavity. Accordingly, advantageously, capacitance measurements can be used to determine the presence of an aerosol generating article in the cavity of the device. Using capacitance measurements to determine the presence of an aerosol generating article in a cavity may allow the aerosol generating device to provide this functionality without the need to provide additional components or sensors in the aerosol generating device.

The aerosol generating device may include a temperature sensor adapted to detect an ambient temperature, wherein the controller is adapted to detect an ambient temperature based on a signal received from the temperature sensor. The temperature sensor may contain a thermistor. The temperature sensor may contain a thermocouple. The temperature sensor may comprise a semiconductor temperature sensor.

The present inventors have realized that when the ambient temperature is low, it is not necessary to power the at least one heater according to the power profile for a substrate having a high water content when a substrate capacitance measurement indicates that the water content of the substrate is high. In particular, the predominantly cold ambient air entering the aerosol generating device during use may be sufficient to maintain the temperature of the generated aerosol at a level acceptable to the user even when the aerosol generating substrate has a high water content. In other words, in these embodiments, the controller determines the power to be supplied to the heater through capacitance measurements and ambient temperature measurements.

In some embodiments, the controller may be configured to supply power from the power supply to at least one heater in a second power profile when the measured capacitance is within a predetermined first range when the measured ambient temperature is below a predetermined ambient temperature threshold. Preferably, the ambient temperature threshold is from about 15 degrees Celsius to about 25 degrees Celsius, preferably from about 17 degrees Celsius to about 23 degrees Celsius. The ambient temperature threshold can be 18 degrees Celsius.

The controller may be configured to measure the capacitance of a capacitor formed by the first electrode, the second electrode, and the portion of the aerosol generating article located between the first electrode and the second electrode, in any suitable manner. In particular, the controller may be configured to measure the capacitance of the capacitor by supplying power from the power supply to the first electrode and the second electrode in the form of alternating current. The alternating current may be of any suitable frequency, and preferably has a frequency in the range of about 100 kHz to 1 GHz. Within the frequency range from approximately 100 kHz to 1 GHz, it may be possible to assume that the relative permeability is constant, ignoring lossy components that occur at particularly high and low frequencies.

The aerosol generating system comprises a first electrode and a second electrode located at a distance from the first electrode such that at least a portion of the aerosol generating substrate is placed between the first electrode and the second electrode when the aerosol generating article is placed inside the cavity. Preferably, when the aerosol generating article is placed in the cavity of the aerosol generating device, the first electrode, the second electrode and the part of the aerosol generating substrate placed between the first electrode and the second electrode form a capacitor.

The first electrode and the second electrode may be provided in the system in various ways. In some preferred first embodiments, the aerosol generating device comprises both a first electrode and a second electrode. In some preferred second embodiments, the aerosol generating article comprises a first electrode and the aerosol generating device comprises a second electrode. In some preferred third embodiments, the aerosol generating article comprises both a first electrode and a second electrode.

The electrodes contained in the aerosol generating device are generally electrically connected to the controller of the aerosol generating device via a wired connection. The electrodes contained in the aerosol generating article may be electrically connected to the controller of the aerosol generating device, when the aerosol generating article is placed in the cavity of the device, through one or more electrical contacts contained in the device, the electrical contacts being electrically connected to the controller via a wired connection.

In preferred first embodiments, the aerosol generating device comprises a first electrode and a second electrode.

In preferred first embodiments, the first electrode and the second electrode may be located in the aerosol generating device in any suitable arrangement. Preferably, the second electrode is aligned with the first electrode along the length of the cavity.

In some preferred first embodiments, the first electrode and the second electrode form part of the interior surface of the cavity. In these embodiments, the first electrode and the second electrode are preferably located on opposite sides of the inner surface of the cavity. The second electrode is preferably located opposite the first electrode. Preferably the first electrode and the second electrode are substantially identical.

In some preferred first embodiments, the first electrode and the second electrode form substantially parallel plates such that the capacitor is a parallel plate capacitor.

In some preferred first embodiments, each of the first electrode and the second electrode extends around substantially half the circumference of the cavity. The first electrode and the second electrode do not extend around half or more than half of the circumference of the cavity, so that the first electrode and the second electrode do not overlap or contact in any way.

In some preferred first embodiments, at least one of the first electrode and the second electrode forms part of at least one heater. In these preferred first embodiments, the other of the first electrode and the second electrode may form part of the interior surface of the cavity.

The provision of the first electrode as part of at least one heater may reduce the number of components needed to manufacture the aerosol generating device. In some embodiments, the implementation of at least one heater contains a resistive heater containing a resistive heating element. In some of these embodiments, the first electrode may be provided separately on a common electrically insulating substrate. In some of these embodiments, the resistive heating element may also form the first electrode, which may further simplify the design of the aerosol generating device.

In some particularly preferred first embodiments, at least one heater comprises an elongated heater adapted to be inserted into an aerosol generating article when the aerosol generating article is placed within a cavity and the first electrode forms part of the elongated heater. In these preferred first embodiments, the second electrode preferably forms part of the inner surface of the cavity. The second electrode may extend substantially along the circumference of the inner surface of the cavity. This may allow the second electrode to surround at least a portion of the aerosol generating article when the aerosol generating article is placed in the cavity. The second electrode may substantially surround the first electrode. The second electrode may be concentric with respect to the first electrode. The second electrode may be a ring electrode.

In preferred second embodiments, the aerosol generating article comprises a first electrode and the aerosol generating device comprises a second electrode. In these preferred second embodiments, the aerosol generating device further comprises a first electrical contact for contact with the first electrode when the aerosol generating article is placed within the cavity.

In preferred second embodiments, the first electrode may be located in the aerosol generating article in any suitable position, and the second electrode may be located in the aerosol generating device in any suitable position. Preferably, the second electrode is aligned with the first electrode along the length of the cavity when the aerosol generating article is placed in the cavity.

Preferably, at least a portion of the first electrode forms part of the radial outer surface of the aerosol generating article. Providing at least a portion of the first electrode on the radial outer surface of the aerosol generating article may facilitate contact between the first electrode and the first electrical contact of the aerosol generating device.

In some second embodiments, the first electrode extends on one side of the aerosol generating article.

In some preferred second embodiments, the first electrode substantially surrounds the aerosol generating substrate. The first electrode may be substantially annular. Providing an annular first electrode may allow the first electrode to contact the first electrical contact of the aerosol generating device, regardless of the angular orientation of the aerosol generating article within the cavity.

In some particularly preferred second embodiments, the aerosol generating article further comprises a wrapper wrapped around the aerosol generating substrate and at least a portion of the first electrode is provided on the outer surface of the wrapper. Advantageously, providing the first electrode on the outer surface of the wrap can substantially prevent water present in the aerosol forming substrate from contacting the first electrode.

In some preferred second embodiments, the aerosol generating device further comprises a first electrical contact for contact with the first electrode when the aerosol generating article is placed within the cavity.

In some preferred second embodiments, the first electrical contact is on one side of the cavity of the aerosol generating device.

In some particularly preferred second embodiments, the first electrical contact substantially surrounds the cavity of the aerosol generating device. The first electrical contact may be substantially annular. Providing an annular first electrical contact may allow the first electrical contact to contact the first electrode of the aerosol generating article, regardless of the angular orientation of the aerosol generating article within the cavity.

In some preferred second embodiments, the second electrode forms part of at least one heater.

In some particularly preferred second embodiments, at least one heater comprises an elongated heater adapted to be inserted into an aerosol generating article when the aerosol generating article is placed within a cavity and the second electrode forms part of the elongated heater. In these particularly preferred second embodiments, the first electrode may substantially surround the aerosol generating substrate such that at least a portion of the aerosol generating substrate is located between the first electrode and the second electrode when the aerosol generating article is placed within the cavity.

In some preferred third embodiments, the aerosol generating article comprises a first electrode and a second electrode. In these preferred third embodiments, the first electrode, the second electrode, and at least a portion of the aerosol-forming substrate located between the first electrode and the second electrode form a capacitor.

In some preferred third embodiments, the first electrode and the second electrode form part of the outer surface of the aerosol generating substrate. In these embodiments, the first electrode and the second electrode are preferably located on opposite sides of the outer surface of the aerosol generating article. The second electrode is preferably located opposite the first electrode. Preferably the first electrode and the second electrode are substantially identical. Preferably, the second electrode is aligned with the first electrode along the length of the aerosol generating article.

In some preferred third embodiments, the first electrode and the second electrode form substantially parallel plates such that the capacitor is a parallel plate capacitor.

In some preferred third embodiments, each of the first electrode and the second electrode extends around substantially half the circumference of the aerosol generating substrate. The first electrode and the second electrode do not extend around half or more than half the circumference of the aerosol-forming substrate, so that the first electrode and the second electrode do not overlap or contact in any way.

In these preferred third embodiments, the aerosol generating device comprises: a first electrical contact for contacting the first electrode of the capacitor when the aerosol generating article is placed within the cavity; and a second electrical contact for contacting the second electrode of the capacitor when the aerosol generating article is placed within the cavity.

In some preferred third embodiments, the first electrical contact and the second electrical contact form part of the interior surface of the cavity. In these embodiments, the first electrical contact and the second electrical contact are preferably located on opposite sides of the inner surface of the cavity. The second electrical contact is preferably located opposite the first electrical contact. Preferably, the first electrical contact and the second electrical contact are substantially identical. The second electrical contact may be aligned with the first electrical contact along the length of the cavity.

In some preferred first embodiments, the first electrical contact and the second electrical contact form substantially parallel plates.

In some preferred first embodiments, each of the first electrical contact and the second electrical contact extends around substantially half the circumference of the cavity. The first electrical contact and the second electrical contact do not extend around half or more than half of the circumference of the cavity, so that the first electrical contact and the second electrical contact do not overlap or otherwise contact.

Preferably, at least one heater comprises at least one resistive heating element. Preferably, at least one heater comprises a plurality of resistive heating elements. Preferably, the resistive heating elements are electrically connected in parallel. Advantageously, providing a plurality of resistive heating elements electrically connected in parallel can help deliver the desired electrical power to at least one heater while reducing or minimizing the voltage required to provide the desired electrical power. Advantageously, reducing or minimizing the voltage required to operate at least one heater can help reduce or minimize the physical size of the power supply.

At least one heater may comprise an electrically insulating substrate, wherein at least one resistive heating element is provided on the electrically insulating substrate.

Preferably, the electrically insulating substrate is stable at the operating temperature of the at least one heater. Preferably, the electrically insulating substrate is stable at temperatures up to about 400 degrees Celsius, more preferably about 500 degrees Celsius, more preferably about 600 degrees Celsius, more preferably about 700 degrees Celsius, more preferably about 800 degrees Celsius. The operating temperature of at least one heater during use may be at least about 200 degrees Celsius. The operating temperature of at least one heater during use may be less than about 700 degrees Celsius. The operating temperature of at least one heater during use may be less than about 600 degrees Celsius. The operating temperature of at least one heater during use may be less than about 500 degrees Celsius. The operating temperature of at least one heater during use may be less than about 400 degrees Celsius.

The electrically insulating substrate may be a ceramic material such as zirconia or alumina. Preferably, the electrically insulating substrate has a thermal conductivity that is less than or equal to about 40 watts per meter kelvin, preferably less than or equal to about 20 watts per meter kelvin, and ideally less than or equal to about 2 watts per meter kelvin.

Suitable materials for forming at least one resistive heating element 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 from ceramic material and metal material. Such composite materials may contain alloyed or unalloyed ceramics. Examples of suitable doped ceramics include doped silicon carbides. Examples of suitable metals include titanium, zirconium, tantalum and the platinum group metals. Examples of suitable metal alloys include stainless steel, nickel, cobalt, chromium, aluminium, titanium, zirconium, hafnium, niobium, molybdenum, tantalum, tungsten, tin, gallium, manganese and iron alloys, as well as nickel, iron, cobalt, stainless steel, Timetal® and iron-manganese-based superalloys. aluminum.

In some embodiments, the implementation of at least one resistance heating element contains one or more stamped parts of an electrically resistive material, such as stainless steel. Alternatively, the at least one resistive heating element may comprise a heating wire or filament, such as a Ni-Cr (nickel-chromium), platinum, tungsten or alloy wire.

The at least one heater may be adapted to be inserted into the aerosol generating substrate when the aerosol generating substrate is placed within the cavity. At least one heater may be located within the cavity. At least one heater may be an oblong heater. The elongated heater may be in the form of a plate. At least one elongated heater may be in the form of a pin. The elongated heater may be cone shaped.

In some embodiments, one of the electrodes forms part of the heater. In some of these embodiments, the electrode is provided on the electrically insulating substrate of the heater. The electrode may be provided on the electrically insulating substrate of the heater in a pattern. The pattern may be any suitable pattern for capacitive coupling with the second electrode. In some of these embodiments, the heater comprises one or more resistive heating elements and the electrode comprises one of the resistive heating elements.

In some preferred embodiments, the aerosol generating device comprises an extractor. The extractor is configured to at least partially extract the aerosol generating article from the cavity of the aerosol generating device. The extractor is movable within the cavity of the aerosol generating device. Preferably, the extractor is movable along the length of the cavity of the aerosol generating device.

In some preferred embodiments, the extractor is tubular. In other words, the extractor comprises a substantially tubular body forming an extractor cavity. The extractor cavity is configured to receive at least a portion of the aerosol generating article. When the aerosol generating article is placed in the cavity of the extractor and the extractor is placed in the cavity of the aerosol generating device, the cavity, the extractor and the aerosol generating article can be aligned coaxially.

An extractor may be particularly desirable in systems containing aerosol generating devices having an elongated heater adapted to be inserted into an aerosol generating article. The extractor may assist in removing the aerosol generating article from the elongated heater without rupturing the aerosol generating article.

In some embodiments, the extractor comprises at least one of a first electrode and a second electrode. The part forming the electrode of the extractor may be contained in the extractor in any suitable manner. For example, the part forming the electrode of the extractor may be located on the outer surface of the extractor, may be located on the inner surface of the extractor, in the cavity of the extractor, or may be built into the main part of the extractor. Providing at least a portion of the electrode on the outer surface of the extractor may facilitate electrical connection of the electrode to the device controller. For example, a portion of the electrode on the outer surface of the extractor may be in contact with an electrical contact on the cavity surface of the device. Providing at least a portion of the electrode on the inner surface of the extractor may position an electrode adjacent to the outer surface of the aerosol generating article placed in the cavity of the extractor, which can improve the sensitivity of the capacitor formed by the first and second electrodes to the water content of the aerosol generating substrate in the aerosol generating article.

The electrode portion of the extractor may be connected to the controller of the aerosol generating device in any suitable manner. In some embodiments, the electrode portion of the extractor may be connected to the controller of the aerosol generating device via a flexible circuit. In some embodiments, the aerosol generating device further comprises an electrical contact for contact with the extractor electrode when the extractor is placed within the cavity.

In some particularly preferred embodiments, at least one heater comprises an elongated heater adapted to be inserted into an aerosol generating article when the aerosol generating article is placed within a cavity. In these particularly preferred embodiments, the aerosol generating device comprises a tubular extractor for extracting the aerosol generating article from a cavity, the extractor being positionable in the cavity and movable in the cavity relative to the elongated heater. In these particularly preferred embodiments, the first electrode forms part of the oblong heater and the second electrode forms part of the extractor.

In these particularly preferred embodiments, the second electrode may be located in the extractor in any suitable position. Preferably, the second electrode is aligned with the first electrode along the length of the cavity when the extractor is placed in the cavity.

In some embodiments, at least a portion of the second electrode forms part of the outer surface of the extractor. In some embodiments, at least a portion of the second electrode forms part of the interior surface of the extractor.

The second electrode may extend on one side of the aerosol generating article. The second electrode may substantially surround the extractor. The second electrode may be substantially annular.

In some of these particularly preferred embodiments, the aerosol generating device comprises a second electrical contact for contact with the second electrode when the extractor is placed in the cavity. The second electrical contact may be on one side of the cavity of the aerosol generating device. The second electrical contact may substantially surround the cavity of the aerosol generating device. The second electrical contact may be substantially annular.

In some particularly preferred embodiments, the first electrode and the second electrode form part of the extractor.

In some of these particularly preferred embodiments, at least a portion of the first electrode and the second electrode form part of the outer surface of the extractor. In some of these particularly preferred embodiments, at least a portion of the first electrode and the second electrode form part of the interior surface of the extractor. In these embodiments, the first electrode and the second electrode are preferably located on opposite sides of the extractor. The second electrode is preferably located opposite the first electrode. Preferably the first electrode and the second electrode are substantially identical. Preferably the second electrode is aligned with the first electrode along the length of the extractor. The first electrode and the second electrode may form substantially parallel electrodes. Each of the first electrode and the second electrode may extend around substantially half of the circumference of the extractor.

In some of these particularly preferred embodiments, the aerosol generating device comprises: a first electrical contact for contact with the first electrode when the extractor is placed within the cavity; and a second electrical contact for contacting the second electrode when the extractor is placed within the cavity. The first electrical contact and the second electrical contact may form part of the interior surface of the cavity. The first electrical contact and the second electrical contact may be located on opposite sides of the inner surface of the cavity. The second electrical contact may be located opposite the first electrical contact. The first electrical contact and the second electrical contact may be substantially identical. The second electrical contact may be aligned with the first electrical contact along the length of the cavity. The first electrical contact and the second electrical contact form substantially parallel plates. Each of the first electrical contact and the second electrical contact may extend around substantially half of the circumference of the cavity.

The aerosol generating device comprises a controller. The controller may be any suitable controller. The controller may include any suitable electrical circuitry and electrical components. Preferably, the controller includes a processor and a memory. The controller may include a microprocessor, which may be a programmable microprocessor.

The aerosol generating device contains a power supply. The power supply may be a DC voltage source. In preferred embodiments, the power supply is a battery. For example, the power supply may be a nickel metal hydride battery, a nickel cadmium battery, or a lithium battery such as a lithium cobalt, lithium iron phosphate, or lithium polymer battery. The power supply may alternatively be another form of charge storage device such as a capacitor. The power supply may need to be recharged and may have a capacity that allows sufficient energy to be stored for use of the aerosol generating device with one or more aerosol generating substrates.

Preferably, the aerosol generating device comprises a housing. Preferably, the housing at least partially defines a cavity for receiving the aerosol generating substrate.

Preferably, the aerosol generating device comprises at least one air inlet in fluid communication with the cavity. In embodiments in which the aerosol generating device comprises a housing, preferably the housing at least partially defines at least one air inlet. Preferably, at least one air inlet is in fluid communication with the upstream end of the cavity. In embodiments where the at least one heater is at least one elongated heater located within the cavity, preferably the at least one elongated heater extends into the cavity from the upstream end of the cavity.

The aerosol generating device may include a sensor for detecting airflow indicative of a puff being taken by the consumer. The air flow sensor is an electromechanical device. The airflow sensor may be any of: a mechanical device, an optical device, an optical-mechanical device, and a microelectromechanical systems (MEMS) sensor. The aerosol generating device may include a manually operated switch to initiate a puff by the user.

Preferably, the aerosol generating device includes an indicator to indicate when at least one heater is activated. The indicator may include a light source that is activated when at least one heater is activated.

The aerosol generating device may include at least one of an external plug or connector and at least one external electrical contact, allowing the aerosol generating device to be connected to another electrical device. For example, the aerosol generating device may include a USB plug or USB connector to allow the aerosol generating device to be connected to another USB equipped device. For example, a USB plug or USB connector may allow the aerosol generating device to be connected to a USB charger to charge the rechargeable power pack inside the aerosol generating device. The USB plug or USB connector may additionally or alternatively support data transfer to or from the aerosol generating device, or both to and from the aerosol generating device. Additionally or alternatively, the aerosol generating device may be connected to a computer to transfer data, such as new heating profiles for new aerosol generating articles, to the device.

In embodiments where the aerosol generating device comprises a USB plug or USB connector, the aerosol generating device may further comprise a removable cap that fits over the USB plug or USB connector when not in use. In embodiments where the USB plug or USB connector is a USB plug, the USB plug may additionally or alternatively be selectively retractable from the device.

In the context of this document, the term "aerosol-generating article" refers to an article containing an aerosol-forming substrate that, when heated, releases volatile compounds that can form an aerosol.

Preferably, the aerosol-forming substrate is a solid aerosol-forming substrate. Preferably, the aerosol forming substrate comprises tobacco. Preferably, the aerosol-forming substrate is a solid aerosol-forming substrate containing tobacco. The aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavor compounds that are released from the substrate upon heating.

The solid substrate forming the aerosol may contain tobacco extrusion. The tobacco extrusion may contain, for example, one or more of: powder, granules, pellets, pieces, threads, strips or sheets containing one or more of: grass leaf, tobacco leaf, tobacco veins, expanded tobacco, and homogenized tobacco. In the context of this document, the term "homogenized tobacco material" means a material formed by agglomeration of bulk tobacco. Providing homogenized tobacco material can improve aerosol generation, nicotine content, and flavor profile of the aerosol generated during heating of the aerosol generating article. In particular, the process for making homogenized tobacco includes shredding the tobacco leaf, which more efficiently allows nicotine and flavors to be released when heated. If the tobacco rod contains homogenized tobacco material, the homogenized tobacco material may be in the form of a sheet. In the context of this document, the term "sheet" means a layered element having a width and length substantially greater than its thickness.

The aerosol-forming solid substrate may comprise homogenized tobacco material. The solid aerosol-forming material may comprise pieces, strands, or strips of homogenized tobacco material. The solid substrate forming the aerosol may comprise a sheet of homogenized tobacco material.

Sheets of homogenized tobacco material can be formed by agglomerating loose tobacco obtained by grinding or otherwise grinding one or both of the tobacco leaf blade and tobacco leaf stems. Sheets of homogenized tobacco material may contain one or more of tobacco dust, tobacco fines, and other by-products of bulk tobacco generated, for example, during tobacco processing, handling, and shipping. The sheets of homogenized tobacco material are preferably formed by a molding process of the type that typically includes molding a slurry containing loose tobacco and one or more binders onto a conveyor belt or other support surface, drying the shaped slurry to form a sheet of homogenized tobacco material, and removing the sheet of homogenized tobacco material from the support surface.

The aerosol-forming solid substrate may comprise a collected sheet of homogenized tobacco material. As used herein, the term "assembled" is used to describe a sheet that is folded, folded, or otherwise compressed or narrowed substantially perpendicular to the longitudinal axis of the aerosol generating article.

In some preferred embodiments, the aerosol forming substrate comprises an assembled textured sheet of homogenized tobacco material. As used herein, the term "textured sheet" means a sheet that has been corrugated, embossed, blind embossed, perforated, or otherwise deformed. The use of a textured sheet of homogenized tobacco material can advantageously simplify the collection of the sheet of homogenized tobacco material to form an aerosol forming substrate. The aerosol forming substrate may comprise an assembled textured sheet of homogenized tobacco material containing a plurality of spaced apart recesses, protrusions, perforations, or a combination thereof.

In a particularly preferred embodiment, the aerosol forming substrate comprises an assembled corrugated sheet of homogenized tobacco material. As used herein, the term "corrugated sheet" means a sheet having a plurality of substantially parallel pleats or corrugations. Preferably, substantially parallel pleats or corrugations extend along or parallel to the longitudinal axis of the aerosol generating article. This advantageously simplifies the collection of the corrugated sheet of homogenized tobacco material to form an aerosol generating article. However, it should be understood that corrugated sheets of homogenized tobacco material for inclusion in an aerosol generating article may alternatively or additionally have a plurality of substantially parallel folds or corrugations that are located at an acute or obtuse angle to the longitudinal axis of the aerosol generating article.

The aerosol forming substrate may comprise tobacco-containing material and non-tobacco material.

The aerosol generating substrate may contain an aerosol generating agent. The aerosol-forming substrate may comprise a single aerosol-forming agent or a combination of two or more aerosol-forming agents. As used herein, the term "aerosol generating agent" is used to describe any suitable known compound or mixture of compounds that, when used, promotes aerosol formation and is substantially resistant to thermal degradation at the operating temperature of the aerosol generating article. Suitable aerosol forming agents include, but are not limited to: polyhydric alcohols such as propylene glycol, triethylene glycol, 1,3-butanediol, and glycerin; 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. Preferred aerosol forming agents are polyhydric alcohols or mixtures thereof, such as propylene glycol, triethylene glycol, 1,3-butanediol, and most preferably glycerol. The content of the aerosol-forming substrate in the aerosol-forming substrate may be greater than 5 percent based on dry weight. The content of aerosol forming agent in the aerosol forming aerosol substrate may be from about 5 percent to about 30 percent, based on dry weight. The aerosol-forming substrate may have a content of about 20 percent by dry weight.

The aerosol generating substrate preferably comprises homogenized tobacco material, aerosol generating agent and water.

The homogenized tobacco material may be provided in the form of sheets that are one of the following: folded, corrugated, or cut into strips. In a particularly preferred embodiment, the sheets are cut into strips having a width of from about 0.2 millimeters to about 2 millimeters, more preferably from about 0.4 millimeters to about 1.2 millimeters. In one embodiment, the width of the strips is approximately 0.9 millimeters.

The aerosol generating article may have an overall length of from about 30 millimeters to about 100 millimeters. The aerosol generating article may have an outer diameter of from about 5 millimeters to about 13 millimeters.

The aerosol generating article may include a mouthpiece located downstream of the aerosol generating substrate. The mouthpiece may be placed at the downstream end of the aerosol generating article. The mouthpiece may be a cellulose acetate filter plug. Preferably, the mouthpiece is about 7 millimeters long, but may be from about 5 millimeters to about 10 millimeters long.

The aerosol forming substrate may have a length of approximately 10 millimeters. The tobacco rod may be approximately 12 millimeters long.

The diameter of the aerosol generating substrate may be from about 5 millimeters to about 12 millimeters.

In a preferred embodiment, the aerosol generating article has an overall length of from about 40 millimeters to about 50 millimeters. Preferably, the aerosol generating article has an overall length of approximately 45 millimeters. Preferably, the aerosol generating article has an outer diameter of approximately 7.2 millimeters.

According to a second aspect of the present invention, an aerosol generating system is provided, comprising: an aerosol generating article comprising an aerosol generating substrate, wherein the aerosol generating substrate is a dielectric material; and an aerosol generating device. The aerosol generating device comprises: a power supply unit; at least one heater; a cavity for accommodating an aerosol generating article; a first electrode and a second electrode; and controller. The second electrode is located at a distance from the first electrode such that at least a portion of the aerosol-forming substrate is placed between the first electrode and the second electrode. The first electrode, the aerosol generating substrate portion, and the second electrode form a capacitor when the aerosol generating article is placed inside the cavity. The controller is configured to: control the power supply from the power supply to at least one heater to heat the aerosol generating substrate when the aerosol generating product is placed inside the cavity. The controller is further configured to: measure the capacitance of the capacitor through the first and second electrodes when the aerosol generating article is placed inside the cavity; supplying power from the power supply to at least one heater in the first power profile when the measured capacitance is within a predetermined first range; and supplying power from the power supply to at least one heater in a second power profile different from the first power profile when the measured capacitance is within a predetermined second range.

According to a third aspect of the present invention, an aerosol generating system is provided, comprising: an aerosol generating article; and an aerosol generating device. The aerosol-generating article comprises: an aerosol-generating substrate, wherein the aerosol-generating substrate is a dielectric material; and the first electrode. The aerosol generating device comprises: a power supply unit; at least one heater; and a cavity for receiving an aerosol generating article. The aerosol generating device further comprises: a first electrical contact for contacting the first electrode when the aerosol generating article is placed within the cavity; controller; and a second electrode. When the aerosol-generating article is placed within the cavity, at least a portion of the aerosol-generating substrate is positioned between the first electrode and the second electrode such that the first electrode, the aerosol-generating substrate portion, and the second electrode form a capacitor. The controller of the aerosol generating device is configured to control the power supply from the power supply to at least one heater for heating the aerosol generating substrate when the aerosol generating article is placed inside the cavity. The controller of the aerosol generating device is further configured to: measure the capacitance of the capacitor through the first electrical contact and the second electrode when the aerosol generating article is placed inside the cavity; supplying power from the power supply to at least one heater in the first power profile when the measured capacitance is within a predetermined first range; and supplying power from the power supply to at least one heater in a second power profile different from the first power profile when the measured capacitance is within a predetermined second range.

According to a fourth aspect of the present invention, an aerosol generating system is provided, comprising: an aerosol generating article; and an aerosol generating device. The aerosol-generating article comprises: an aerosol-generating substrate, wherein the aerosol-generating substrate is a dielectric material; and a capacitor comprising a first electrode, a second electrode, and at least a portion of the aerosol-forming substrate disposed between the first electrode and the second electrode. The aerosol generating device comprises: a power supply unit; at least one heater; and a cavity for receiving an aerosol generating article. The aerosol generating device further comprises: a first electrical contact for contacting the first electrode of the capacitor when the aerosol generating article is placed inside the cavity; a second electrical contact for contacting the second electrode of the capacitor when the aerosol generating article is placed inside the cavity; and controller. The controller is configured to control the supply of power from the power supply to at least one heater for heating the aerosol generating substrate when the aerosol generating article is placed inside the cavity. The controller is further configured to: measure the capacitance of the capacitor through the first and second electrical contacts when the aerosol generating article is placed inside the cavity; supplying power from the power supply to at least one heater in the first power profile when the measured capacitance is within a predetermined first range; and supplying power from the power supply to at least one heater in a second power profile different from the first power profile when the measured capacitance is within a predetermined second range.

According to a fifth aspect of the present invention, an aerosol generating device according to a second aspect of the present invention is provided. In other words, an aerosol generating device is provided, comprising: a power supply; at least one heater; a cavity for accommodating an aerosol generating article; a first electrode and a second electrode; and controller. The second electrode is located at a distance from the first electrode such that at least a portion of the aerosol generating article is placed between the first electrode and the second electrode when the aerosol generating article is placed inside the cavity. The controller is configured to control the supply of power from the power supply to at least one heater for heating the aerosol generating article when the aerosol generating article is placed inside the cavity. The controller is further configured to: measure the capacitance through the first electrode and the second electrode when the aerosol generating article is placed inside the cavity; supplying power from the power supply to at least one heater in the first power profile when the measured capacitance is within a predetermined first range; and supplying power from the power supply to at least one heater in a second power profile different from the first power profile when the measured capacitance is within a predetermined second range.

According to a sixth aspect of the present invention, an aerosol generating device according to a third aspect of the present invention is provided. In other words, an aerosol generating device is provided, comprising: a power supply; at least one heater; a cavity for accommodating an aerosol generating article; first electrode; electrical contact; and controller. The electrical contact is located at a distance from the first electrode so that the second electrode of the aerosol generating product can contact the electrical contact when the aerosol generating product is placed inside the cavity, wherein at least a part of the aerosol generating product is placed between the first electrode and the second electrode. The controller is configured to control the supply of power from the power supply to at least one heater for heating the aerosol generating article when the aerosol generating article is placed inside the cavity. The controller is further configured to: measure the capacitance through the first electrode and the second electrode in contact with the electrical contact when the aerosol generating article is placed inside the cavity; supplying power from the power supply to at least one heater in the first power profile when the measured capacitance is within a predetermined first range; and supplying power from the power supply to at least one heater in a second power profile different from the first power profile when the measured capacitance is within a predetermined second range.

According to a seventh aspect of the present invention, an aerosol generating device according to a fourth aspect of the present invention is provided. In other words, an aerosol generating device is provided, comprising: a power supply; at least one heater; a cavity for accommodating an aerosol generating article; a first electrical contact and a second electrical contact located at a distance from the first electrical contact; and controller. The first electrical contact and the second electrical contact are made in such a way that the first electrode of the aerosol generating product can contact the first electrical contact, and the second electrode of the aerosol generating product can contact the second electrical contact when the aerosol generating product is placed inside the cavity, while at least a part of the aerosol generating product is placed between the first electrode and the second electrode. The controller is configured to control the supply of power from the power supply to at least one heater for heating the aerosol generating article when the aerosol generating article is placed inside the cavity. The controller is further configured to: measure capacitance through the first electrical contact and the second electrical contact when the aerosol generating article is placed within the cavity; supplying power from the power supply to at least one heater in the first power profile when the measured capacitance is within a predetermined first range; and supplying power from the power supply to at least one heater in a second power profile different from the first power profile when the measured capacitance is within a predetermined second range.

According to an eighth aspect of the present invention, an aerosol generating device is provided, comprising: a cavity for receiving an aerosol generating article; an oblong heater adapted to be inserted into the aerosol generating article when the aerosol generating article is placed inside the cavity; and a tubular extractor for extracting the aerosol generating article from the cavity. The extractor is made with the possibility of location in the cavity and is movable in the cavity relative to the elongated heater. The aerosol generating device further comprises: a first electrode and a second electrode; power unit; and controller. The second electrode is located at a distance from the first electrode such that at least a portion of the aerosol generating article is placed between the first electrode and the second electrode when the aerosol generating article is placed inside the cavity. The first electrode forms part of the oblong heater and the second electrode forms part of the extractor. The controller is configured to: measure the capacitance through the first electrode and the second electrode; and controlling power supply from the power supply to the heater to heat the aerosol generating article based on the measured capacitance.

According to a ninth aspect of the present invention, there is provided: an aerosol generating device, comprising: a cavity for receiving an aerosol generating article; an oblong heater adapted to be inserted into the aerosol generating article when the aerosol generating article is placed inside the cavity; and a tubular extractor for extracting the aerosol generating article from the cavity. The extractor is made with the possibility of location in the cavity and is movable in the cavity relative to the elongated heater. The aerosol generating device further comprises: a first electrode and a second electrode; power unit; and controller. The second electrode is located at a distance from the first electrode such that at least a portion of the aerosol generating article is placed between the first electrode and the second electrode when the aerosol generating article is placed inside the cavity. The first electrode and the second electrode form part of the extractor. The controller is configured to: measure the capacitance through the first electrode and the second electrode; and controlling power supply from the power supply to the heater to heat the aerosol generating article based on the measured capacitance.

It should be understood that the features described in relation to one aspect of the present invention may also be applied equally to other aspects of the present invention. In particular, the features described with respect to the first aspect of the present invention can be applied equally to the second, third, fourth, fifth, sixth, seventh, eighth and ninth aspects of the present invention, and vice versa.

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

in fig. 1 is a sectional view of an aerosol generating device according to a first embodiment of the present invention;

in fig. 2 is a sectional view of an aerosol generating article for use with the aerosol generating device of FIG. 1;

in fig. 3 is a sectional view of the aerosol generating device of FIG. 1 in combination with the aerosol generating article of FIG. 2 to form an aerosol generating system;

in fig. 4 is a sectional view of a tubular extractor for an aerosol generating device according to a second embodiment of the present invention;

in fig. 5 is a sectional view of an aerosol generating device according to a second embodiment of the present invention, comprising the tubular extractor of FIG. 4;

in fig. 6 is a sectional view of the aerosol generating device of FIG. 5 in combination with the aerosol generating article of FIG. 2 to form an aerosol generating system;

in fig. 7 is a sectional view of an aerosol generating device according to a third embodiment of the present invention;

in fig. 8 is a sectional view of an aerosol generating article for use with the aerosol generating device of FIG. 7;

in fig. 9 is a sectional view of the aerosol generating device of FIG. 7 in combination with the aerosol generating article of FIG. 8 to form an aerosol generating system;

in fig. 10 is a sectional view of an aerosol generating device according to a third embodiment of the present invention;

in fig. 11 is a sectional view of an aerosol generating article for use with the aerosol generating device of FIG. 10; And

in fig. 12 is a sectional view of the aerosol generating device of FIG. 10 in combination with the aerosol generating article of FIG. 11 to form an aerosol generating system.

In FIG. 1 shows an aerosol generating device 110 comprising a housing 112, wherein the housing 112 defines a cavity 114 for receiving an aerosol generating article. The apparatus 110 includes a heater 116 comprising a base portion 118 and an elongated heater plate 120 that penetrates the aerosol generating article when the aerosol generating article is inserted into the cavity 114. The heater plate 120 includes a resistive heating coil 122 for resistively heating the upstream end of the aerosol generating article inserted into the cavity. 114. The controller 124 controls the operation of the device 110, including the supply of electrical current from the power supply 126 in the form of a lithium iron phosphate battery to the resistive heating coil 122 of the heater plate 120.

The resistive heating coil 122 also forms the first electrode 128. The second electrode 130 is provided on the cylindrical inner surface 133 of the cavity 114. In FIG. 1, the second electrode 130 is shown on one side of the cavity 114. However, it should be understood that in other embodiments, the second electrode 130 may be an annular electrode surrounding the inner surface 133 of the cavity 114.

In FIG. 2 shows an aerosol generating article 140 for use in the aerosol generating device 110 of FIG. 1. The aerosol generating article 140 comprises an aerosol generating substrate 142, a hollow acetate tube 144, a polymeric filter 146, a mouthpiece 148, and an outer wrap 150. The aerosol generating substrate 142 comprises a tobacco plug and the mouthpiece 148 comprises a cellulose acetate fiber plug.

In FIG. 3 shows an aerosol generating article 140 inserted into a cavity 114 of an aerosol generating device 110. When the article 140 is inserted into the cavity 114, the pointed tip 136 of the heater plate 120 penetrates the aerosol generating substrate 142, and the aerosol generating substrate 142 is placed over the heater plate 120 such that a portion of the aerosol generating substrate 142 is located between the first electrode 128 and the second electrode 130 when the aerosol generating article 140 is completely placed in the cavity 114. At this position, when the aerosol generating article 140 is placed in the cavity 114, the first electrode 128, part of the aerosol generating substrate 142, between the first electrode 128 and the second electrode 130 and the second electrode 130 form a capacitor. The dielectric material of the capacitor is formed by a portion of the aerosol forming substrate 142 located between the first and second electrodes.

Controller 124 is configured to supply power from power supply 126 to heater plate 120 in a heating cycle to sufficiently heat aerosol forming substrate 142 to generate aerosol.

When the aerosol-generating article 140 is placed in the cavity 114 of the device 110, and before the controller 124 supplies power from the power supply 126 to the heater plate 120 to heat the aerosol-generating substrate 142 in a heating cycle, the controller 124 measures the capacitance of a capacitor formed from the first electrode 128, the aerosol-generating substrate portion 142, and the second electrode 130. The capacitance value provides an indication of the amount of water that is in the portion of the aerosol forming substrate 142 between the first electrode 128 and the second electrode 130.

Controller 124 is configured to use the measured capacitance to adjust the power supplied from power supply 126 to heater plate 120 in a heating cycle. Adjusting the power supplied to heater 120 controls the temperature to which heater plate 120 is heated in a heating cycle. The controller 124 is configured to compare the measured capacitance with a predetermined threshold value stored in the memory of the controller and adjust the power supplied from the power supply 126 to the heater plate 120 based on the comparison. Accordingly, the controller 124 is configured to supply a first power to the heater plate 120 if the container indicates that the amount of water in the aerosol-forming substrate is below a predetermined threshold, and the controller 124 is configured to supply a second power to the heater plate 120 that is below the first power if the container indicates that the amount of water in the aerosol-forming substrate is above a predetermined threshold. In other words, the controller 124 applies the first power to the heater plate 120 when the capacitance is within the first range; and the controller 124 applies a second power, which is lower than the first power, to the heater plate 120 when the capacitance is within the second range, which is higher than the first range.

In FIG. 4 shows an aerosol generating device 210 according to a second embodiment of the present invention. The aerosol generating device 210 is substantially similar to the aerosol generating device 110 of FIG. 1 and the same reference numerals are used to describe the same features. The aerosol generating device 210 includes a housing 212, wherein the housing 212 defines a cavity 214 for receiving the aerosol generating article 140 of FIG. 2. The apparatus 210 includes a heater 216 comprising a base portion 218 and an elongated heater plate 220 that penetrates the aerosol generating article when the aerosol generating article is inserted into the cavity 214. The heater plate 220 includes a resistive heating coil 222 for resistively heating the upstream end of the aerosol generating article inserted into the cavity 214. The controller 224 controls the operation of the device 210, including the supply of electrical current from the power supply 226 in the form of a lithium iron phosphate battery to the resistive heating coil 222 of the heater plate 220.

Resistive heating coil 222 also defines first electrode 228. Electrical contact 230 is provided on the cylindrical inner surface 233 of cavity 214 at a position radially outward from first electrode 228. FIG. 4, connector 230 is shown on one side of cavity 214. However, it should be understood that in other embodiments, electrical contact 230 may be an annular contact surrounding inner surface 233 of cavity 214.

The aerosol generating device 210 further comprises a tubular extractor 260 slid into cavity 214. The tubular extractor 260 is shown in the device 210 of FIG. 4 and 6 and shown removed from device 210 in FIG. 5.

The tubular extractor 260 comprises a generally cylindrical tubular body 262, the body 262 having an open end for receiving an aerosol generating article 140 and a partially closed end 266 having a slot for slidingly receiving a heater plate 220 when the extractor 260 is placed in the cavity 214. The extractor 260 has a cylindrical inner surface defining an extractor cavity 264 that is sized to accommodate aerosol generating article 140 and a cylindrical outer surface 265 that is substantially similar to the inner surface 233 of cavity 214 such that extractor 260 is slidably placed in cavity 214.

The extractor 260 reduces the forces experienced by the aerosol generating article 140 when the article 140 is removed from the cavity 214 compared to the article being removed from the cavity of the system without a tubular extractor. This reduces the likelihood of aerosol generating article 140 rupturing when removed from cavity 214. As an example, when extractor 260 is extended from cavity 214 to extract article 140 from cavity 214, extractor 260 body 262 protects wrapper 150 of article 140 from rubbing against interior surface 233 of cavity. As another example, the partially closed end 266 of extractor 260 abuts against the end surface of article 140 when article 140 is removed from cavity 214 by the extractor, which reduces or eliminates tension on wrapper 150 when article is removed from cavity 214.

The device 210 further comprises a second electrode 268 located on a portion of the outer surface 265 of the body 262 of the extractor 260. The second electrode 268 is located on the outer surface 265 of the body 262 of the extractor 260 and is adapted to contact an electrical contact 230 on the inner surface 133 of the cavity 114 when the extractor 260 is placed in the cavity 214 and the heater plate 220 passes into the socket at the partially closed end 266 extract ora 260.

In this embodiment, second electrode 268 is annular so that it contacts electrical contact 230 regardless of the angular orientation of extractor 260 within cavity 214. It should be understood that in other embodiments, contact 230 may be annular instead of second electrode 268, or both contact 230 and second electrode 268 may be annular.

When the second electrode 268 contacts the electrical contact 230, the second electrode 268 becomes electrically connected to the controller 224 of the device 210. It should be understood that in some embodiments, at least a portion of the second electrode 268 may be located on the inner surface of the extractor body 262, and in some embodiments, at least a portion of the tubular body 262 of the extractor 260 may form the second electrode 268.

In FIG. 6 shows an aerosol generating article 140 inserted into an extractor cavity 264, and an extractor 260 and article 140 inserted into a cavity 214 of the aerosol generating device 210. When the article 140 and extractor 260 are inserted into the cavity 214, the pointed tip 236 of the heater plate 220 is seated in the partially closed end 266 of the extractor 260 and penetrates the aerosol generating substrate 142. The aerosol generating substrate 142 is placed over the heater plate 220 such that a portion of the aerosol generating substrate 142 is located between the first electrode 228 and the second electrode 268 when the aerosol generating article 140 is fully seated in the extractor cavity 264 and the extractor 260 and article 140 are fully seated in the cavity 114. In this position, the first electrode 228, part of the substrate and 142, forming an aerosol, between the first electrode 228 and the second electrode 268 and the second electrode 268 form a capacitor. The dielectric material of the capacitor is formed by a portion of the aerosol forming substrate 142 located between the first and second electrodes.

The controller 224 of the device 210 is configured to measure the capacitance of the capacitor formed by the first electrode 228, part of the aerosol forming substrate 142, between the first electrode 228 and the second electrode 268 and the second electrode 268, as described above with reference to the device 110 shown in FIG. 1.

In FIG. 7 shows an aerosol generating device 310 according to a third embodiment of the present invention. The aerosol generating device 310 is substantially similar to the aerosol generating device 110 of FIG. 1 and the same reference numerals are used to describe the same elements. The aerosol generating device 310 includes a housing 312, wherein the housing 312 defines a cavity 314 for receiving an aerosol generating article. The device 310 includes a heater 316 comprising a base portion 318 and an elongated heater plate 320 that penetrates the aerosol generating article when the aerosol generating article is inserted into the cavity 314. The heater plate 320 includes a resistive heating coil 322 for resistively heating the upstream end of the aerosol generating article inserted into the cavity. 314. The controller 324 controls the operation of the device 310, including the supply of electrical current from the battery 326 in the form of a lithium iron phosphate battery to the resistive heating coil 322 of the heater plate 320.

The resistive heating coil 322 also defines the first electrode 328. An annular electrical contact 330 is provided on the cylindrical inner surface 133 of the cavity 314 at a position radially in line with the first electrode 328 along the length of the cavity 314.

In FIG. 8 shows an aerosol generating article 340 for use in the aerosol generating device 310 of FIG. 7. The aerosol generating article 340 comprises an aerosol generating substrate 342, a hollow acetate tube 344, a polymeric filter 346, a mouthpiece 348, and an overwrap 350. The aerosol generating substrate 342 comprises a tobacco plug and the mouthpiece 348 comprises a cellulose acetate fiber plug.

The aerosol generating article 340 further comprises a second electrode 352 attached to the outer wrap 350 adjacent to the aerosol generating substrate 342. For clarity, the thickness of the first electrode 352 has been exaggerated in FIG. 8.

Electrical contact 330 is positioned to contact second electrode 352 when aerosol generating article 340 is fully inserted into cavity 314. Electrical contact 330 is annular such that it contacts second electrode 352 regardless of the angular orientation of aerosol generating article 340 within cavity 314. It will be appreciated that in other embodiments, second electrode 352 may be annular instead of electrical contact 330, or both electrical contact 330 and second electrode 352 may be annular.

In FIG. 9 shows an aerosol generating article 340 inserted into a cavity 314 of an aerosol generating device 310. When the article 340 is inserted into the cavity 314, the pointed tip 336 of the heater plate 320 penetrates the aerosol generating substrate 342, and the aerosol generating substrate 342 is placed over the heater plate 320 such that a portion of the aerosol generating substrate 342 is located between the first electrode 328 and the second electrode 330 when the aerosol generating article 340 is fully placed in the cavity 314. At this position, when the aerosol generating article 340 is placed in the cavity 314, the first electrode 328, part of the aerosol generating substrate 342, between the first electrode 328 and the second electrode 352 and the second electrode 352 form a capacitor. The dielectric material of the capacitor is formed by a portion of the aerosol forming substrate 342 located between the first and second electrodes.

The controller 324 of the device 310 is configured to measure the capacitance of the capacitor formed by the first electrode 328, part of the aerosol forming substrate 342, between the first electrode 328 and the second electrode 352 and the second electrode 352, as described above with reference to the device 110 shown in FIG. 1.

In FIG. 10 shows an aerosol generating device 410 according to a fourth embodiment of the present invention. The aerosol generating device 410 is substantially similar to the aerosol generating device 110 of FIG. 1 and the same reference numerals are used to describe the same elements. The aerosol generating device 410 includes a housing 412, wherein the housing 412 defines a cavity 414 for receiving the aerosol generating article. The device 410 includes a heater 416 comprising a base portion 418 and an elongated heater plate 420 that penetrates the aerosol generating article when the aerosol generating article is inserted into the cavity 414. The heater plate 420 includes a resistive heating coil 422 for resistively heating the upstream end of the aerosol generating article inserted into the cavity 414. The controller 424 controls the operation of the device 410, including the supply of electrical current from the battery 426 in the form of a lithium iron phosphate battery to the resistive heating coil 422 of the heater plate 420.

In this embodiment, the resistive heating coil 422 does not form the first electrode. The first electrical contact 428 is provided on the cylindrical inner surface 433 of the cavity 414 in a position in line with the resistive heating coil 422 along the length of the cavity 414. The second electrical contact 430 is also provided on the cylindrical inner surface 433 opposite the first electrical contact 428. Both the first and second electrical contacts are electrically connected to the controller 424 of the device 410.

In FIG. 11 shows an aerosol generating article 440 for use in the aerosol generating device 410 of FIG. 10. The aerosol generating article 440 comprises an aerosol generating substrate 442, a hollow acetate tube 444, a polymeric filter 446, a mouthpiece 448, and an outer wrap 450. The aerosol generating substrate 442 comprises a tobacco plug and the mouthpiece 448 comprises a cellulose acetate fiber plug.

The aerosol generating article 440 further comprises a first electrode 452 attached to one side of the outer wrap 450 adjacent to the aerosol generating substrate 442. The aerosol generating article 440 also includes a second electrode 454 attached to the opposite side of the outer wrap 450 adjacent to the aerosol generating substrate 442. The first and second electrodes are substantially identical, each forming an arcuate electrode extending around slightly less than half the circumference of article 440 such that the electrodes do not overlap or contact in any way. The first electrode 452, part of the aerosol forming substrate 442, between the first electrode 428 and the second electrode 452 and the second electrode 452 form a capacitor. The dielectric material of the capacitor is formed by a portion of the aerosol forming substrate 442 located between the first and second electrodes.

For clarity, the thickness of the first and second electrodes has been exaggerated in FIG. eleven.

The first electrical contact 428 of the device 410 is positioned to contact one of the first electrode 452 and the second electrode 454 of the article 440, and the second electrical contact 430 of the device 410 is positioned to contact the other of the first electrode 452 and the second electrode 454 of the article 440 when the aerosol generating article 440 is fully inserted into the cavity 414. Each of the first and second electrodes extends around substantially half the circumference of the article 440 such that each of the first and second contacts of device 410 is in contact with one of the electrodes of article 440 regardless of the angular orientation of aerosol generating article 440 within cavity 414.

In FIG. 12 shows an aerosol generating article 440 inserted into a cavity 414 of an aerosol generating device 410. Upon insertion of article 440 into cavity 414, pointed tip 436 of heater plate 420 penetrates aerosol-forming substrate 442, and aerosol-forming substrate 442 is placed over heater plate 420 such that one of the first and second electrical contacts contacts the first electrode 452 and the other of the first and second electrical contacts contacts the second electrode 454 when the product 340, generator containing an aerosol, is completely located in the cavity 414.

The controller 424 of the device 410 is configured to measure the capacitance of the capacitor formed by the first electrode 452, part of the aerosol forming substrate 442, between the first electrode 452 and the second electrode 454 and the second electrode 454 as described above with reference to the device 110 shown in FIG. 1.

The controllers of the aerosol generating devices described above may not necessarily be configured to determine the volume fraction of water present in the aerosol generating substrate. The predetermined relationship between the capacitance and the volume fraction of water present in the aerosol forming substrate can be used to determine thresholds against which the measured capacitance can be compared to determine the power to be supplied to the heater. However, in some embodiments, the controller may be configured to determine the volume fraction of water in the aerosol-forming substrate between the first and second electrodes. In these embodiments, the volume fraction of water in the aerosol-forming substrate can be calculated as follows.

The relative permeability of a material generally depends on the temperature and frequency of the applied electric field. The relative permeability of water can be considered to be approximately 80 at a temperature of approximately 20 degrees Celsius and at applicable frequencies from approximately 100 kHz to 1 GHz.

If the geometry of the electrodes and the material between the electrodes is known, the overall relative permeability of the materials between the electrodes can be determined. In addition, if the materials between the electrodes are known, as are their respective relative conductivities, the volume fraction of materials between the electrodes can be determined from capacitance measurements.

As an example, the Landau-Lifshitz-Looyeng dielectric mixture equation can be used to determine the relative permeability of a mixture of two components with intrinsic dielectric constants, as shown in Equation 1 below:

Equation 1

where ε _bulk is the total relative permeability of the material between the electrodes, ε ₁ is the relative permeability of water, ε ₂ is the relative permeability of the aerosol forming substrate, and σ is the volume fraction of water in the material.

The relationship between the capacitance and the total relative permeability of the material between the electrodes depends on the geometry of the capacitor. For example, in an embodiment in which the first electrode is formed by a heating element extending centrally through the aerosol-forming substrate and the second electrode is formed by a cylindrical foil wrap surrounding the aerosol-forming substrate, the capacitor can be approximated to a cylindrical capacitor, with the capacitance of the capacitor given by Equation 2 below:

Equation 2

where C is the measured capacitance, ε ₀ is the free space permeability, r _outer is the radius of the outer second electrode, and r _inner is the radius of the central first electrode.

Provided that the radii of the first and second electrodes are known and the relative permeabilities of water and the aerosol-forming substrate are known, the measured capacitance between the first and second electrodes can be entered into Equation 2 to determine the total relative permeability, and the total relative permeability can be entered into Equation 1 to determine the volume fraction of water in the aerosol-forming substrate. A certain volume fraction of water or absolute volume of water in the aerosol forming substrate can be used to control the power supplied to the heater.

It should be understood that the above-described embodiments are only exemplary embodiments of the present invention. It should also be understood that the features described above in relation to one embodiment of the invention may also be applied to other embodiments of the invention.

Claims (72)

1. An aerosol generating system, comprising: an aerosol-generating article comprising an aerosol-generating substrate, wherein the aerosol-generating substrate is a dielectric material and the aerosol-generating substrate is substantially solid; And an aerosol generating device, comprising: power unit; at least one heater; a cavity for accommodating an aerosol generating article; And a controller configured to control the supply of power from the power supply to said at least one heater for heating the aerosol generating substrate when the aerosol generating article is placed inside the cavity; And a first electrode and a second electrode located at a distance from the first electrode such that at least a portion of the aerosol-generating substrate is placed between the first electrode and the second electrode when the aerosol-generating article is placed inside the cavity, wherein the first electrode, a portion of the aerosol-generating substrate, and the second electrode form a capacitor when the aerosol-generating article is placed inside the cavity, wherein the controller of the aerosol generating device is additionally configured to: measuring the capacitance of the capacitor by means of the first and second electrodes when the aerosol generating article is placed inside the cavity; supplying power from the power supply to said at least one heater in a first power profile when the measured capacitance is within a predetermined first range; And supplying power from the power supply to said at least one heater in a second power profile different from the first power profile, when the measured capacitance is within a predetermined second range. 2. The aerosol generating system of claim 1, wherein the predetermined first range is an open range and the controller is configured to supply power from the power supply to said at least one heater in the first power profile when the measured capacitance exceeds the predetermined first threshold; and wherein the predetermined second range is an open range and the controller is configured to supply power from the power supply to said at least one heater in a second power profile different from the first power profile when the measured capacitance is less than or equal to the predetermined second threshold value. 3. The aerosol generating system of claim 2, wherein the predetermined first threshold is equal to the predetermined second threshold. 4. The aerosol generating system of claim 1, wherein the predetermined first range is a closed range and the controller is configured to supply power from the power supply to said at least one heater in the first power profile when the measured capacitance is between a predetermined first lower threshold and a predetermined first high threshold; and in which the predetermined second range is a closed range, and the controller is configured to supply power from the power supply to said at least one heater in a second power profile different from the first power profile when the measured capacitance is between a predetermined second lower threshold value and a predetermined second upper threshold value. 5. The aerosol generating system of claim 4, wherein the predetermined first lower threshold is equal to the predetermined second upper threshold. 6. An aerosol generating system according to any one of claims 1 to 5, wherein the controller is configured to prevent power from being supplied from the power supply to said at least one heater when the capacitance measurement exceeds a predetermined upper threshold. 7. The aerosol generating system of claim 1, wherein the controller is configured to prevent power from being supplied from the power supply to said at least one heater when the capacitance measurement is below a predetermined lower threshold. 8. An aerosol generating system according to claim 1, wherein the aerosol generating device comprises a first electrode and a second electrode. 9. The aerosol generating system of claim 8, wherein at least one of the first electrode and the second electrode forms part of said at least one heater. 10. An aerosol generating system according to claim 9, wherein said at least one heater comprises an elongated heater adapted to be inserted into an aerosol generating article when the aerosol generating article is placed inside the cavity, wherein the first electrode forms part of the elongated heater and the second electrode is located on the inner surface of the cavity. 11. The aerosol generating system according to claim 8, wherein said at least one heater comprises an elongated heater adapted to be inserted into an aerosol generating article, when the aerosol generating article is placed inside the cavity, the first electrode forming part of the elongated heater, the aerosol generating device comprises a tubular extractor for extracting the aerosol generating article from the cavity, the extractor is configured to be located in the cavity and is movable in the cavity of the relatively elongated heater, and the second electrode forms part of the extractor. 12. The aerosol generating system of claim 10 or 11, wherein the second electrode is substantially annular such that the second electrode surrounds at least a portion of the aerosol generating article when the aerosol generating article is placed within the cavity. 13. An aerosol generating system according to claim 1, wherein: the aerosol generating article comprises a first electrode; And an aerosol generating device comprises: a first electrical contact for contacting the first electrode when the aerosol generating article is placed within the cavity; And second electrode. 14. The aerosol generating system of claim 13, wherein the aerosol generating article further comprises a wrapper wrapped around the aerosol generating substrate, and wherein at least a portion of the first electrode is provided on the outer surface of the wrapper. 15. An aerosol generating system according to claim 13 or 14, wherein the second electrode forms part of said at least one heater. 16. The aerosol generating system of claim 15, wherein said at least one heater comprises an elongated heater adapted to be inserted into an aerosol generating article when the aerosol generating article is placed within the cavity, wherein the second electrode forms part of the elongated heater and the first electrode substantially surrounds the aerosol generating substrate, such that at least a portion of the aerosol generating substrate is disposed between the first electrode and the second electrode, when the aerosol generating article is placed inside the cavity. 17. An aerosol generating system according to claim 1, wherein: the aerosol generating article comprises a first electrode and a second electrode, wherein the first electrode, the second electrode and at least a portion of the aerosol generating substrate located between the first electrode and the second electrode form a capacitor; And an aerosol generating device comprises: a first electrical contact for contacting the first electrode of the capacitor when the aerosol generating article is placed inside the cavity; And a second electrical contact for contacting the second electrode of the capacitor when the aerosol generating article is placed within the cavity. 18. The aerosol generating system of claim 1, wherein the controller is further configured to measure capacitance prior to applying power from the power supply to said at least one heater to heat the aerosol generating substrate. 19. The aerosol generating system of claim 1, wherein the controller is further configured to periodically measure the capacitance and adjust the power supplied to the heater to heat the aerosol generating substrate at periodic intervals based on the measured capacitance. 20. The aerosol generating system of claim 1, wherein the aerosol generating device comprises means for detecting a puff and the controller is further configured to measure capacitance when a puff is detected. 21. The aerosol generating system according to claim 1, in which the controller is further configured to determine when the aerosol generating article is placed in the cavity, based on the measured capacitance, and sequentially supply power from the power supply to said at least one heater in one of the first and second power profiles, when it is determined that the aerosol generating article is placed in the cavity. 22. The aerosol generating system according to claim 1, in which the aerosol generating device further comprises a temperature sensor adapted to measure the ambient temperature, and wherein the controller is configured to determine the ambient temperature based on the signal from the temperature sensor and supply power from the power supply to said at least one heater in the second power profile, when the measured capacitance is within a predetermined first range and the measured ambient temperature is below a predetermined ambient temperature threshold. 23. An aerosol generating device, comprising: power unit; at least one heater; a cavity for receiving an aerosol-generating article, the aerosol-generating article comprising an aerosol-generating substrate, the aerosol-generating substrate being a dielectric material and the aerosol-generating substrate being substantially solid; a first electrode and a second electrode spaced apart from the first electrode such that at least a portion of the aerosol generating article is placed between the first electrode and the second electrode when the aerosol generating article is placed inside the cavity; And controller configured to: controlling the power supply from the power supply to said at least one heater for heating the aerosol generating article when the aerosol generating article is placed inside the cavity; measuring capacitance through the first electrode and the second electrode when the aerosol generating article is placed inside the cavity; supplying power from the power supply to said at least one heater in a first power profile when the measured capacitance is within a predetermined first range; And supplying power from the power supply to said at least one heater in a second power profile different from the first power profile, when the measured capacitance is within a predetermined second range. 24. An aerosol generating device, comprising: power unit; at least one heater; a cavity for receiving an aerosol-generating article, the aerosol-generating article comprising an aerosol-generating substrate, the aerosol-generating substrate being a dielectric material and the aerosol-generating substrate being substantially solid; first electrode; And an electrical contact located at a distance from the first electrode such that the second electrode of the aerosol generating article can contact the electrical contact when the aerosol generating article is placed within the cavity and at least a portion of the aerosol generating article is placed between the first electrode and the second electrode; And controller configured to: controlling the power supply from the power supply to said at least one heater for heating the aerosol generating article when the aerosol generating article is placed inside the cavity; measuring capacitance through the first electrode and the second electrode in contact with the electrical contact when the aerosol generating article is placed inside the cavity; supplying power from the power supply to said at least one heater in a first power profile when the measured capacitance is within a predetermined first range; And supplying power from the power supply to said at least one heater in a second power profile different from the first power profile, when the measured capacitance is within a predetermined second range. 25. An aerosol generating device, comprising: power unit; at least one heater; a cavity for receiving an aerosol-generating article, the aerosol-generating article comprising an aerosol-generating substrate, the aerosol-generating substrate being a dielectric material and the aerosol-generating substrate being substantially solid; a first electrical contact and a second electrical contact located at a distance from the first electrical contact, wherein the first electrical contact and the second electrical contact are configured such that the first electrode of the aerosol generating article can contact the first electrical contact, and the second electrode of the aerosol generating article can contact the second electrical contact when the aerosol generating article is placed inside the cavity, wherein at least a portion of the aerosol generating article is placed between the first electrode and the second electrode; And controller configured to: controlling the power supply from the power supply to said at least one heater for heating the aerosol generating article when the aerosol generating article is placed inside the cavity; measuring capacitance through the first electrical contact and the second electrical contact when the aerosol generating article is placed within the cavity; supplying power from the power supply to said at least one heater in a first power profile when the measured capacitance is within a predetermined first range; And supplying power from the power supply to said at least one heater in a second power profile different from the first power profile, when the measured capacitance is within a predetermined second range.