Aerosol-generating systems, articles, and devices

Abstract

An aerosol-generating system (1) is described that includes an aerosol-generating article (2) (or consumable) and an aerosol-generating device (6). The aerosol-generating article (2) includes an aerosol-generating material (16) having a first outer surface (16a) and a second outer surface (16b) generally opposite the first outer surface (16b), a first non-conductive layer (18a) adjacent to the first outer surface (16a), and a second non-conductive layer (18b) adjacent to the second outer surface (16b). The aerosol-generating device (6) includes a first electrode (8) and a second electrode (10). When the aerosol-generating article (2) is received in the device (6), in use, the first electrode (8) is positioned adjacent to the first non-conductive layer (18a) and the second electrode (10) is positioned adjacent to the second non-conductive layer (18b). The first non-conductive layer (18a) has an inner surface and an outer surface, and the aerosol-generating article (2) includes a first conductive layer (26) positioned between the first outer surface (16a) of the aerosol-generating material (16) and the inner surface of the first non-conductive layer (18a).

Description

[Technical Field]

[0001] The present disclosure relates generally to aerosol-generating articles, and more particularly to aerosol-generating articles adapted to be received within an aerosol-generating device to generate an aerosol for inhalation by a user. The present disclosure also relates to an aerosol-generating system comprising an aerosol-generating component and an aerosol-generating device.

[0002] The present disclosure is particularly applicable to portable (handheld) aerosol generating devices. [Background technology]

[0003] In recent years, devices that heat, rather than burn, aerosol-generating materials to generate an aerosol for inhalation have become popular with consumers. Commonly available risk-reducing or risk-modifying devices are material-heated aerosol-generating devices or so-called heat-and-burn devices. These types of devices generate an aerosol or vapor by heating the aerosol-generating material to a temperature typically in the range of 150-300°C. This temperature range is significantly lower than that of a typical cigarette. Heating the aerosol-generating material to a temperature within this range, without burning or combusting the aerosol-generating material, generates a vapor that typically cools and condenses to form an aerosol for inhalation by the device user.

[0004] Such devices may provide heat to the aerosol-generating material using one of several different techniques. One approach is designed to heat an electrically conductive aerosol-generating material, e.g., tobacco material doped with a conductive material such as a carbon-based material, by applying an electric current to the aerosol-generating material. The aerosol-generating material is thus heated directly (Joule heated) by the electric current flowing through the aerosol-generating material, instead of being heated indirectly, e.g., by an external heater or by one or more susceptors located outside the aerosol-generating material, as in the case of an induction heating system. The aerosol-generating material may be part of an aerosol-generating article that a user inserts into the device for use. Heating the aerosol-generating material typically requires that at least a portion of the aerosol-generating material be exposed to the surface of the aerosol-generating article so that an electrical connection can be made with the device. This may be unacceptable to users, for example, due to the risk that the user's fingers may come into contact with the exposed aerosol-generating material or because some of the aerosol-generating material may leak from the article. Embodiments of the present disclosure therefore seek to solve this problem by providing an alternative method of heating the aerosol-generating material by configuring the aerosol-generating system as a capacitor and applying an electric field across the aerosol-generating material. Such an arrangement may provide direct heating, even when the conductive aerosol-generating material is surrounded by a non-conductive wrapper, such as a paper wrapper. The present disclosure also provides an embodiment in which the aerosol-generating material is non-conductive, i.e., the aerosol-generating material is not doped with a conductive material. Summary of the Invention [Means for solving the problem]

[0005] According to a first aspect of the present disclosure, there is provided an aerosol generation system comprising: an aerosol-generating material having a first outer surface and a second outer surface generally opposite the first outer surface; a first non-conductive layer adjacent to the first outer surface; a second non-conductive layer adjacent to the second outer surface; a first electrode adjacent to the first non-conductive layer; a second electrode adjacent to the second non-conductive layer.

[0006] The aerosol-generating material and the first and second non-conductive layers may be part of an aerosol-generating article (or consumable).

[0007] The first and second electrodes may be part of an aerosol-generating device adapted to receive the aerosol-generating article during use. When the aerosol-generating article is received within the aerosol-generating device, for example within the aerosol-generation space or heating chamber of the device, the first electrode is positioned adjacent to the first non-conductive layer, and the second electrode is positioned adjacent to the second non-conductive layer. It will be readily understood from the following description that this does not preclude one or more additional layers being positioned between the first electrode and the first non-conductive layer, or between the second non-conductive layer and the second electrode. Such additional layers may, for example, be part of the aerosol-generating article.

[0008] The first and second electrodes may be substantially planar and may define a pair of conductive parallel capacitor plates separated by a dielectric comprising at least first and second non-conductive layers. In some arrangements, the dielectric also includes the aerosol-generating material, if the aerosol-generating material is formed from a non-conductive material. The aerosol-generating system is therefore generally configured as a capacitor. The first electrode may be connected to a first terminal (e.g., a positive terminal), and the second electrode may be connected to a second terminal (e.g., a negative terminal). When a voltage is applied across the first and second terminals to charge the capacitor, a net positive charge collects at the positive electrode (e.g., the first electrode) and a net negative charge collects at the negative electrode (e.g., the second electrode), for example, if the aerosol-generating device further comprises a circuit electrically connected between the first and second terminals with a power source (e.g., a battery). An electric field is generated between the first and second electrodes. The capacitor may be charged until its voltage value is approximately equal to the voltage of the power source. When the capacitor is fully charged, no current flows through the circuit. The capacitor may be discharged, for example, through a resistor. As explained in more detail below, charging and discharging the capacitor heats the aerosol-generating material, generating an aerosol for the user to inhale.

[0009] The circuit may further include a switching device (e.g., one or more switches). The switching device may be closed to charge the capacitor and open to discharge the capacitor. The one or more switches may be semiconductor switching devices. The one or more switches may be opened and closed (or switched on and off) by a controller.

[0010] The first electrode may have a surface area substantially equal to the surface area of ​​the first outer surface of the aerosol-generating material or the surface area of ​​the outer surface of the first non-conductive layer. The second electrode may have a surface area substantially equal to the surface area of ​​the second outer surface of the aerosol-generating material or the surface area of ​​the outer surface of the second non-conductive layer. It will be understood that the capacitance of a parallel-plate capacitor is proportional to the smallest area of ​​the first and second electrodes and inversely proportional to the distance or spacing between them. The aerosol-generating material may be substantially rectangular, and the first and second outer surfaces of the aerosol-generating material may have surfaces of the rectangular parallelepiped with the largest surface areas to maximize capacitance. Maximizing capacitance may improve the efficiency of aerosol generation. In other arrangements, the first electrode may have a surface area greater or smaller than the surface area of ​​the first outer surface of the aerosol-generating material or the outer surface of the first non-conductive layer, and the second electrode may have a surface area greater or smaller than the surface area of ​​the second outer surface of the aerosol-generating material or the outer surface of the second non-conductive layer, for example.

[0011] The first and second electrodes may be formed from any suitable conductive material, such as, for example, aluminum.

[0012] The aerosol-generating material may include plant-derived materials, and in particular tobacco materials.

[0013] The aerosol-generating material may be a non-conductive material or a conductive material, and may further comprise, for example, a carbon-based material such as charcoal, or a metal such as aluminum. In particular, the aerosol-generating material may comprise a non-conductive material as a substrate, such as a plant-derived material or tobacco material, which is then doped with a conductive material, such as a carbon-based material or metal particles, to make it conductive.

[0014] Upon heating, the aerosol-generating material may release one or more volatile compounds, which may include nicotine or flavor compounds such as tobacco or other flavorings.

[0015] When the aerosol-generating material is conductive, the first non-conductive layer functions as a first dielectric between the first electrode and the aerosol-generating material. The second non-conductive layer functions as a second dielectric between the aerosol-generating material and the second electrode. For example, when a voltage is applied across the first and second terminals to charge the capacitor, a current flows through the aerosol-generating material due to the electric field generated between the first and second electrodes. A net negative charge collects on the first outer surface of the aerosol-generating material facing the first electrode, and a net positive charge collects on the second outer surface of the aerosol-generating material facing the second electrode. When the capacitor is discharged, current flows in the opposite direction through the aerosol-generating material. Due to the internal resistance of the aerosol-generating material, the current flowing through the aerosol-generating material when the capacitor is charged and discharged provides direct heating of the aerosol-generating material by Joule heating. When the capacitor is charged, the first and second non-conductive layers are polarized by the electric field so that positive charges in the layers are slightly displaced in the direction of the electric field and negative charges are slightly displaced in the opposite direction. When the capacitor is discharged, the polarization is released.

[0016] If the aerosol-generating material is non-conductive, the aerosol-generating material and the first and second non-conductive layers function as a dielectric between the first and second electrodes. Charging and discharging the capacitor dissipates heat at the first and second electrodes, heating the adjacent aerosol-generating material. When the capacitor is charged, i.e., when an electric field is generated between the first and second electrodes, current does not flow through the aerosol-generating material, as in the case of the conductive aerosol-generating material described above. Instead, the aerosol-generating material is polarized so that positive charges within the aerosol-generating material (and the first and second non-conductive layers) are slightly displaced in the direction of the electric field and negative charges are slightly displaced in the opposite direction to the electric field. When the capacitor is discharged, the polarization is released and the charges can return to their original positions. The moving positive and negative charges interact with the internal resistance of the aerosol-generating material to provide direct heating of the aerosol-generating material when the capacitor is charged and discharged.

[0017] In both arrangements, direct heating is provided without the need to expose any portion of the aerosol-generating material. The aerosol-generating material may therefore be completely surrounded by a wrapper, such as a paper wrapper, which may form the first and second non-conductive layers. There is no risk of a user's fingers coming into contact with the exposed aerosol-generating material, or of any portion of the aerosol-generating material leaking from the aerosol-generating article.

[0018] The first non-conductive layer may have an inner surface and an outer surface, the inner surface facing the aerosol-generating material and the outer surface facing the first electrode.

[0019] The second non-conductive layer may have an inner surface and an outer surface, the inner surface facing the aerosol-generating material and the outer surface facing the second electrode.

[0020] In one arrangement, the aerosol-generating article further comprises a first conductive layer (e.g., a first aluminum layer) positioned between the outer surface of the first non-conductive layer and the first electrode. Similarly, the aerosol-generating article further comprises a second conductive layer (e.g., a second aluminum layer) positioned between the outer surface of the second non-conductive layer and the second electrode. When the aerosol-generating article is received in an aerosol-generating device, the first conductive layer may be in electrical contact with the first electrode, and the second conductive layer may be in electrical contact with the second electrode. The first and second conductive layers may provide increased heating of the aerosol-generating material when the capacitor is charged and discharged. Because the first and second conductive layers function as electrodes directly facing the aerosol-generating material, they may increase the available capacitance. If the first electrode is a positive electrode and the second electrode is a negative electrode, for example, when a voltage is applied across the first and second terminals to charge the capacitor, a net positive charge collects in the first conductive layer and a net negative charge collects in the second conductive layer. For example, a first electrode assembly (e.g., a positive electrode assembly) may include a first electrode and a first conductive layer, and a second electrode assembly (e.g., a negative electrode assembly) may include a second electrode and a second conductive layer.

[0021] If the aerosol-generating material is non-conductive, the aerosol-generating material and the first and second non-conductive layers act as a dielectric between the first and second electrode assemblies. Charging and discharging the capacitor dissipates heat in the first and second electrodes and the first and second conductive layers, heating the adjacent aerosol-generating material. The aerosol-generating material also heats when the aerosol-generating material (and the first and second non-conductive layers) are polarized and depolarized by an electric field due to the interaction of the moving positive and negative charges with the internal resistance of the aerosol-generating material, as described above.

[0022] When the aerosol-generating material is a conductive material, the first non-conductive layer functions as a first dielectric between the first electrode assembly and the aerosol-generating material. The second non-conductive layer functions as a second dielectric between the aerosol-generating material and the second electrode assembly. For example, when the first electrode assembly is positive and the second electrode assembly is negative, a voltage is applied across the first and second terminals to charge a capacitor, and an electric field is generated between the first and second electrode assemblies, causing a current to flow through the aerosol-generating material. Specifically, when a voltage is applied across the first and second terminals, the first and second non-conductive layers become polarized. This polarization of the first and second non-conductive layers generates an electric field across the aerosol-generating material, thereby causing a current to flow through the aerosol-generating material. A net negative charge collects on a first outer surface of the aerosol-generating material facing the first electrode / conductive layer, and a net positive charge collects on a second outer surface of the aerosol-generating material facing the second electrode / conductive layer. When the capacitor is discharged, current flows in the opposite direction through the aerosol-generating material. Due to the internal resistance of the aerosol-generating material, the current flowing through the aerosol-generating material when the capacitor is charged and discharged provides direct heating of the aerosol-generating material by Joule heating.

[0023] The surface area of ​​the first conductive layer may be larger than the surface area of ​​the outer surface of the first non-conductive layer (or the first outer surface of the aerosol-generating material), and / or the surface area of ​​the second conductive layer may be larger than the surface area of ​​the outer surface of the second non-conductive layer (or the second outer surface of the aerosol-generating material). Making the first and / or second conductive layers slightly larger than the corresponding outer surfaces of the non-conductive layers or aerosol-generating material may increase the available capacitance while also accommodating manufacturing tolerances.

[0024] In another arrangement, the aerosol-generating article may further comprise a first conductive layer (e.g., a first aluminum layer) positioned between the first outer surface of the aerosol-generating material and the inner surface of the first non-conductive layer. Similarly, the aerosol-generating article may further comprise a second conductive layer (e.g., a second aluminum layer) positioned between the second outer surface of the aerosol-generating material and the inner surface of the second non-conductive layer. In this arrangement, the first and second conductive layers may be positioned within a wrapper, such as a paper wrapper, which may make the aerosol-generating article more user-friendly. For example, the user does not need to directly touch the first and second conductive layers, thereby avoiding electrical interaction with the user (e.g., static shock). The first and second conductive layers are also protected by the wrapper. The wrapper may prevent the first and / or second conductive layers from being damaged or soiled, which could result in a reduction in available capacitance. The first and second non-conductive layers may be defined by a portion of the wrapper, as described in more detail below.

[0025] When the aerosol-generating material is a non-conductive material, the first non-conductive layer functions as a first dielectric between the first electrode and the first conductive layer. The second non-conductive layer functions as a second dielectric between the second conductive layer and the second electrode. The aerosol-generating material functions as a third dielectric between the first and second conductive layers. For example, if the first electrode is positive and the second electrode is negative, when a voltage is applied across the first and second terminals to charge a capacitor, an electric field generated between the first and second electrodes will cause polarization of the aerosol-generating material. In particular, when a voltage is applied across the first and second terminals, the first and second non-conductive layers become polarized. The first and second non-conductive layers then charge the first and second conductive layers, which function as electrodes directly facing the aerosol-generating material. The aerosol-generating material is then polarized by the first and second conductive layers. A net negative charge collects on the outer surface of the first conductive layer facing the first electrode, and a net positive charge collects on the inner surface of the first conductive layer facing the aerosol-generating material. A net negative charge collects on the inner surface of the second conductive layer facing the aerosol-generating material, and a net positive charge collects on the outer surface of the second conductive layer facing the second electrode. When the capacitor is discharged, the aerosol-generating material is depolarized. Charging and discharging the capacitor dissipates heat at the first and second electrodes and the first and second conductive layers, heating the adjacent aerosol-generating material. The aerosol-generating material is also heated by the interaction of the moving positive and negative charges with the internal resistance of the aerosol-generating material, as described above, when the aerosol-generating material (and the first and second non-conductive layers) are polarized and depolarized by the electric field.

[0026] When the aerosol-generating material is a conductive material, the first non-conductive layer functions as a first dielectric between the first electrode and the first conductive layer. The second non-conductive layer functions as a second dielectric between the second conductive layer and the second electrode. The first and second conductive layers are preferably in electrical contact with the aerosol-generating material, and they may together function as a conductive layer between the first and second non-conductive layers. For example, when the first electrode is positive and the second electrode is negative, when a voltage is applied across the first and second terminals to charge a capacitor, the electric field generated between the first and second electrodes causes a current to flow through the first and second conductive layers and the aerosol-generating material, thereby providing direct heating of the aerosol-generating material by Joule heating. In particular, when a voltage is applied across the first and second terminals, the first and second non-conductive layers become polarized. The first and second non-conductive layers then act as electrodes directly facing the aerosol-generating material, charging the first and second conductive layers which apply an electric field across the aerosol-generating material. A net negative charge collects on the outer surface of the first conductive layer facing the first electrode, and a net positive charge collects on the outer surface of the second conductive layer facing the second electrode. When the capacitor is discharged, current flows in opposite directions through the first and second conductive layers and the aerosol-generating material.

[0027] The aerosol-generating material may be part of the aerosol precursor section of the aerosol-generating article. The aerosol-generating article may further comprise a cooling section (or filter section) at the proximal end. The first and second electrodes preferably do not extend over or overlap the cooling section when the article is received in the device. In other words, the cooling section is preferably positioned outside the space defined between the first and second electrodes when the article is received in the device. The cooling section may comprise, for example, cellulose acetate fibers. The cooling section may constitute a mouthpiece filter. In some designs, one or more vapor collection regions, cooling regions, and other structures may also be included. The vapor cooling region may advantageously allow the vapor to cool and condense, for example through a filter segment, to form an aerosol with suitable properties for inhalation by a user. Generally speaking, a vapor is a substance that is in the gas phase below its critical temperature, meaning that it may be condensed into a liquid by increasing the pressure without decreasing the temperature, while an aerosol is fine solid particles or liquid droplets suspended in air or another gas. However, it should be noted that the terms "aerosol" and "vapor" may be used interchangeably herein.

[0028] The first non-conductive layer may have a surface area that is approximately the same as the surface area of ​​the first outer surface of the aerosol-generating material, and the second non-conductive layer may have a surface area that is approximately the same as the surface area of ​​the second outer surface of the aerosol-generating material.

[0029] The first and second non-conductive layers may be formed by wrappers (e.g., paper wrappers) that extend substantially around the aerosol-generating material. It will be readily understood that in this arrangement, the first non-conductive layer is the portion of the wrapper adjacent to a first outer surface of the aerosol-generating material, and the second non-conductive layer is the portion of the wrapper adjacent to a second outer surface of the aerosol-generating material. The wrappers may extend around other outer surfaces of the aerosol-generating material and may also substantially surround the aerosol precursor section and, optionally, the cooling section of the aerosol-generating article. Generally, it is preferred that at least the aerosol-generating material be completely surrounded by the paper wrapper so that none of the aerosol-generating material is exposed.

[0030] According to a second aspect of the present disclosure, there is provided an aerosol-generating article comprising: an aerosol-generating material (e.g., a non-conductive or conductive material—see above) having a first outer surface and a second outer surface opposite the first outer surface; An aerosol-generating article is provided that includes a non-conductive wrapper that extends generally around an aerosol-generating material and defines a first non-conductive layer adjacent to a first outer surface and a second non-conductive layer adjacent to a second outer surface.

[0031] According to a third aspect of the present disclosure, there is provided an aerosol-generating device adapted, in use, to receive the aerosol-generating article described above, the device comprising a first electrode (e.g., a first capacitor plate) adjacent, in use, to a first non-conductive layer, and a second electrode (e.g., a second capacitor plate) adjacent, in use, to a second non-conductive layer. [Brief explanation of the drawings]

[0032] [Figure 1] 1 is a schematic diagram of an aerosol generation system having an aerosol-generating device and an aerosol-generating article. [Figure 2] 2 is a schematic perspective view of the aerosol-generating article of FIG. 1. [Figure 3] 2 is a schematic side view of the aerosol-generating article of FIG. 1 showing the aerosol precursor section and the cooling section. [Figure 4] 2 is a schematic plan view of the aerosol-generating article of FIG. 1 showing the aerosol precursor section and the cooling section. [Figure 5] 2 is a cross-sectional schematic view of the aerosol generation system of FIG. 1, in which a first aerosol-generating article is received in the aerosol-generating device. [Figure 6] 6 is a schematic cross-sectional view taken along line AA in FIG. 5. [Figure 7] 2 is a cross-sectional schematic view of the aerosol generation system of FIG. 1, in which a second aerosol-generating article is received in the aerosol-generating device. [Figure 8] 8 is a schematic cross-sectional view taken along line BB in FIG. 7. [Figure 9] 2 is a cross-sectional schematic view of the aerosol generation system of FIG. 1, in which a third aerosol-generating article is received in the aerosol-generating device. [Figure 10] 10 is a schematic cross-sectional view taken along line CC in FIG. 9. [Figure 11] 2 is a schematic cross-sectional view of the aerosol generation system of FIG. 1, in which a fourth aerosol-generating article is received in the aerosol-generating device. [Figure 12] 12 is a schematic cross-sectional view taken along line DD in FIG. 11. [Figure 13] 10 is a perspective schematic view of a fifth aerosol-generating article. [Figure 14] 2 is a schematic cross-sectional view of the aerosol generation system of FIG. 1, in which a sixth aerosol-generating article is received in the aerosol-generating device. [Figure 15] 15 is a schematic cross-sectional view taken along line EE in FIG. 14. [Figure 16] 2 is a schematic cross-sectional view of the aerosol generation system of FIG. 1, in which a seventh aerosol-generating article is received in the aerosol-generating device. [Figure 17] 17 is a schematic cross-sectional view taken along line FF in FIG. 16. DETAILED DESCRIPTION OF THE INVENTION

[0033] Embodiments of the present disclosure will now be described, by way of example only, and with reference to the accompanying drawings, in which:

[0034] Referring initially to FIG. 1 , a schematic diagram illustrates one embodiment of an aerosol generation system 1 including an aerosol-generating article 2 (or consumable) adapted to be received in an aerosol-generation space or heating chamber 4 of an aerosol-generating device 6.

[0035] The aerosol-generating device 6 includes a positive electrode 8 and a negative electrode 10 adjacent to the aerosol-generation space 4. The positive and negative electrodes 8, 10 may be formed from any suitable conductive material, such as, for example, aluminum.

[0036] 1 to 4, the aerosol-generating article 2 has a generally rectangular parallelepiped structure and includes a first outer surface 2a and a second outer surface 2b opposite the first outer surface 2a. The first outer surface 2a and the second outer surface 2b are rectangular parallelepiped surfaces with maximum surface area to maximize capacitance, see below. Maximizing capacitance may improve the efficiency of aerosol generation.

[0037] The aerosol-generating article 2 includes an aerosol precursor section 12 and a cooling section 14 at its proximal end. The aerosol precursor section 12 includes a rectangular prism of aerosol-generating material 16 having a first outer surface 16a and a second outer surface 16b opposite the first outer surface 16a. When heated, the aerosol-generating material 16 may release one or more volatile compounds. The volatile compounds may include flavor compounds, such as nicotine or tobacco or other flavorings. At least the aerosol precursor section 12 is surrounded by a wrapper 18, such as a paper wrapper, to prevent a user from directly touching the aerosol-generating material 16 due to hygiene requirements. In the illustrated aerosol-generating article 2, the wrapper 18 extends around the outer surface of the aerosol-generating material 16 such that the material is completely surrounded by the wrapper and the adjacent cooling section 14 of the aerosol-generating article 2. The wrapper 18 also extends around the cooling section 14.

[0038] The wrapper 18 defines a first non-conductive layer 18a adjacent to the first outer surface 16a of the aerosol-generating material 16 and a second non-conductive layer 18b adjacent to the second outer surface 16b of the aerosol-generating material 16, if the wrapper 18 is non-conductive.

[0039] As shown in Figures 5-12 and 14-17, when the aerosol-generating article 2 is received in the aerosol-generation space 4 of the aerosol-generating device 6, the positive electrode 8 is positioned adjacent to the first non-conductive layer 18a, and the negative electrode 10 is positioned adjacent to the second non-conductive layer 18b. Note that in the aerosol-generating systems shown in Figures 9-12, the positive and negative electrodes 8, 10 are not directly adjacent to the first and second non-conductive layers 18a, 18b, but are spaced from the first and second non-conductive layers 18a, 18b by first and second conductive layers 26, 28, which will be described in more detail below. At least a portion of the cooling section 14 is positioned outside the aerosol-generation space 4 so that the positive and negative electrodes 8, 10 do not overlap excessively with the cooling section when the aerosol-generating article 2 is received in the aerosol-generating device 6.

[0040] The electrodes 8, 10 are generally planar and define a pair of conductive parallel capacitor plates separated by a dielectric comprising first and second non-conductive layers 18a, 18b. In the arrangement shown in Figures 5 and 6, the aerosol-generating material 16 is a non-conductive material (e.g., a plant-derived material, particularly tobacco material), and the dielectric therefore also comprises the aerosol-generating material. The aerosol-generating system 1 is generally configured as a capacitor.

[0041] The positive electrode 8 has a surface area that is approximately the same as the surface area of ​​the first outer surface 16a of the aerosol-generating material 16. The negative electrode 10 has a surface area that is approximately the same as the surface area of ​​the second outer surface 16b of the aerosol-generating material 16. Alternatively, the positive electrode 8 has a surface area that is larger than the surface area of ​​the first outer surface 16a of the aerosol-generating material 16, and / or the negative electrode 10 has a surface area that is larger than the surface area of ​​the second outer surface 16b of the aerosol-generating material 16. This may provide reliable contact between the positive electrode 8 and the first outer surface 16a and / or between the negative electrode 10 and the second outer surface 16b, even when the aerosol-generating article 2 is not fully inserted into the aerosol-generation space 4.

[0042] The positive electrode 8 is connected to a positive terminal 20, and the negative electrode 10 is connected to a negative terminal 22. The aerosol-generating device 6 includes a circuit 24 electrically connected between the positive and negative terminals 20, 22 by a power source (not shown) and a switching device (not shown) that is closed to charge the capacitor and opened to discharge the capacitor. When a voltage is applied across the positive and negative terminals 20, 22 to charge the capacitor, a net positive charge collects at the positive electrode 8 and a net negative charge collects at the negative electrode 10. An electric field is created between the positive and negative electrodes 8, 10. The capacitor may be charged until its voltage value is approximately equal to the voltage across the positive and negative electrodes 8, 10. When the capacitor is fully charged, current ceases to flow through the circuit 24. The capacitor may be discharged, for example, through a resistor forming part of the circuit 24. Charging and discharging the capacitor heats the aerosol-generating material 16, generating an aerosol for the user to inhale.

[0043] Charging and discharging the capacitor dissipates heat at the positive and negative electrodes 8, 10, heating the adjacent aerosol-generating material 16. When the capacitor is charged, i.e., when an electric field is generated between the positive and negative electrodes 8, 10, the aerosol-generating material 16 becomes polarized such that the positive charges within the aerosol-generating material (and the first and second non-conductive layers 18a, 18b) are slightly displaced in the direction of the electric field and the negative charges are slightly displaced in the direction opposite the electric field. When the capacitor is discharged, the polarization is released and the charges can return to their original positions. The moving positive and negative charges interact with the internal resistance of the aerosol-generating material 16 to provide direct heating of the aerosol-generating material. In Figures 6, 8, 10, 12, 15, and 17, the polarization of the individual dielectric layers during capacitor charging is indicated by positive and negative signs ("+" and "-").

[0044] In the arrangements shown in Figures 7 and 8, the aerosol-generating material 16 is a conductive material (e.g., a plant-derived material, particularly tobacco material, as a substrate doped with a conductive material, such as a carbon-based material or metal particles, to make it conductive). The first non-conductive layer 18a serves as a first dielectric between the positive electrode 8 and the aerosol-generating material 16. The second non-conductive layer 18b serves as a second dielectric between the aerosol-generating material 16 and the negative electrode 10. When the capacitor is charged, the electric field generated between the positive and negative electrodes 8 and 10 causes current to flow through the aerosol-generating material 16. When the capacitor is discharged, current flows in the opposite direction through the aerosol-generating material 16. Due to the internal resistance of the aerosol-generating material 16, the current flowing through the aerosol-generating material when the capacitor is charged and discharged provides direct heating of the aerosol-generating material by Joule heating. In Figures 8, 12, and 17, the current flow during capacitor charging is indicated by vertical arrows. The first and second non-conductive layers 18a, 18b are polarized by an electric field such that positive charges within the layers are slightly displaced in the direction of the electric field and negative charges are slightly displaced in the direction opposite the electric field.

[0045] In both of these arrangements, direct heating is provided without the need to expose any portion of the aerosol-generating material 16. There is no risk of a user's fingers coming into contact with the exposed aerosol-generating material 16, nor is there any risk of any portion of the aerosol-generating material leaking out of the aerosol-generating article 2.

[0046] In the arrangements shown in Figures 9-13, the aerosol-generating article 2 further includes a first conductive layer 26 (e.g., a first aluminum layer) positioned between the outer surface of the first non-conductive layer 18a and the positive electrode 8. Similarly, the aerosol-generating article 2 further includes a second conductive layer 28 (e.g., a second aluminum layer) positioned between the outer surface of the second non-conductive layer 18b and the negative electrode 10. As shown in Figures 9-12, when the aerosol-generating article 2 is received in the aerosol-generating device 6, the first conductive layer 26 is in electrical contact with the positive electrode 8, and the second conductive layer 28 is in electrical contact with the negative electrode 10. The first and second conductive layers 26, 28 provide increased heating of the aerosol-generating material when the capacitor is charged and discharged. Because the first and second conductive layers 26, 28 function as positive and negative electrodes directly facing the aerosol-generating material 16, they increase the available capacitance. The positive electrode 8 and the first conductive layer 26 may function as a single positive electrode assembly, and the negative electrode 10 and the second conductive layer 28 may function as a single negative electrode assembly. In these embodiments, full insertion of the aerosol-generating article 2 into the aerosol-generation space 4 and full contact between the aerosol-generating article 2 and the positive and negative electrodes 8, 10 are no longer required to maximize available capacitance. This may make it easier for users to use the aerosol generation system 1. More specifically, in these embodiments, the positive electrode 8 need not have a surface area larger than or equal to the surface area of ​​the first outer surface 16a of the aerosol-generating material 16, and / or the negative electrode 10 need not have a surface area larger than or equal to the surface area of ​​the second outer surface 16b of the aerosol-generating material 16. Thus, narrower or smaller positive and / or negative electrodes may be used. This may mean that the positive and / or negative electrodes 8, 10 are not exposed at the proximal end of the aerosol-generating device 6. This may also prevent the transfer of static charge from the user to the positive and / or negative electrodes 8,10.

[0047] 9 and 10, the aerosol-generating material 16 is a non-conductive material. The aerosol-generating material 16 and the first and second non-conductive layers 18a, 18b function as a dielectric between the positive and negative electrode assemblies (i.e., as defined by the positive electrode 8 and the first conductive layer 26, and the negative electrode 10 and the second conductive layer 28, respectively). Charging and discharging the capacitor dissipates heat at the positive and negative electrodes 8, 10 and the first and second conductive layers 26, 28, heating the adjacent aerosol-generating material 16. The aerosol-generating material 16 is also heated by the interaction of the moving positive and negative charges with the internal resistance of the aerosol-generating material when the aerosol-generating material (and the first and second non-conductive layers 18a, 18b) are polarized and depolarized by an electric field, as described above.

[0048] In the arrangements shown in Figures 11 and 12, the aerosol-generating material 16 is an electrically conductive material. The first non-conductive layer 18a serves as a first dielectric between the positive electrode assembly (i.e., as defined by the positive electrode 8 and the first electrically conductive layer 26) and the aerosol-generating material 16. The second non-conductive layer 18b serves as a second dielectric between the aerosol-generating material 16 and the negative electrode assembly (i.e., as defined by the negative electrode 10 and the second electrically conductive layer 28). When the capacitor is charged, an electric field generated between the positive and negative electrode assemblies causes a current to flow through the aerosol-generating material 16. In particular, when a voltage is applied between the first and second terminals 20, 22, the first and second electrically conductive layers 18a, 18b become polarized. This polarization of the first and second electrically conductive layers 18a, 18b generates an electric field across the aerosol-generating material 16, which causes a current to flow through the aerosol-generating material. When the capacitor is discharged, a current flows in the opposite direction through the aerosol-generating material 16. Due to the internal resistance of the aerosol-generating material 16, the current flowing through the aerosol-generating material when the capacitor is charged and discharged provides direct heating of the aerosol-generating material by Joule heating.

[0049] 13, the surface area of ​​the first conductive layer 26 may be larger than the surface area of ​​the outer surface of the first non-conductive layer 18a. The surface area of ​​the second conductive layer 28 may be larger than the surface area of ​​the outer surface of the second non-conductive layer 18b. Making the first and second conductive layers 26, 28 slightly larger than the corresponding outer surfaces of the aerosol-generating material 16 and the first and second non-conductive layers 18a, 18b may increase the available capacitance while also accommodating manufacturing tolerances.

[0050] 14-17, the aerosol-generating article 2 further comprises a first conductive layer 26 (e.g., a first aluminum layer) positioned between the first outer surface 16a of the aerosol-generating material 16 and the inner surface of the first non-conductive layer 18a. Similarly, the aerosol-generating article 2 further comprises a second conductive layer 28 (e.g., a second aluminum layer) positioned between the second outer surface 16b of the aerosol-generating material 16 and the inner surface of the second non-conductive layer 18b. In this arrangement, the first and second conductive layers 26, 28 are positioned inside the wrapper 18, which may make the aerosol-generating article 2 more user-friendly. For example, the user does not need to directly touch the first and second conductive layers 26, 28, thereby avoiding electrical interaction with the user (e.g., static shock). The first and second conductive layers 26, 28 are also protected by the wrapper 18. The wrapper 18 may protect the first and second conductive layers 26, 28 from being damaged or contaminated, which could result in a reduction in available capacitance.

[0051] In the arrangements shown in Figures 14 and 15, the aerosol-generating material 16 is a non-conductive material. The first non-conductive layer 18a serves as a first dielectric between the first electrode 8 and the first conductive layer 26. The second non-conductive layer 18b serves as a second dielectric between the second conductive layer 28 and the second electrode 10. The aerosol-generating material 16 serves as a third dielectric between the first and second conductive layers 26, 28. When the capacitor is charged, an electric field generated between the first and second electrodes 8, 10 causes polarization of the aerosol-generating material 16. In particular, when a voltage is applied between the first and second terminals 20, 22, the first and second non-conductive layers 18a, 18b become polarized. The first and second non-conductive layers 18a, 18b then charge the first and second conductive layers 26, 28, which function as positive and negative poles, respectively, directly facing the aerosol-generating material 16. The aerosol-generating material 16 is then polarized by the first and second conductive layers 26, 28. When the capacitor is discharged, the polarization of the aerosol-generating material 16 is removed. Charging and discharging the capacitor dissipates heat at the first and second electrodes 8, 10 and the first and second conductive layers 26, 28, heating the adjacent aerosol-generating material 16. The aerosol-generating material 16 is also heated by the interaction of the moving positive and negative charges with the internal resistance of the aerosol-generating material, as explained above, when the aerosol-generating material (and first and second non-conductive layers 18a, 18b) are polarized and removed by the electric field.

[0052] In the arrangements shown in Figures 16 and 17, the aerosol-generating material 16 is a conductive material. The first non-conductive layer 18a serves as a first dielectric between the first electrode 8 and the first conductive layer 26. The second non-conductive layer 18b serves as a second dielectric between the second conductive layer 28 and the second electrode 10. The first and second conductive layers 26, 28 are in electrical contact with the aerosol-generating material 16 and serve as conductive layers between the first and second non-conductive layers 18a, 18b. When the capacitor is charged, an electric field generated between the first and second electrodes 8, 10 causes current to flow through the first and second conductive layers 26, 28 and the aerosol-generating material 16, thereby providing direct heating of the aerosol-generating material by Joule heating. In particular, when a voltage is applied between the first and second terminals 20, 22, the first and second non-conductive layers 18a, 18b become polarized. The first and second non-conductive layers 18a, 18b then charge the first and second conductive layers 26, 28, which directly face the aerosol-generating material 16 and act as positive and negative poles, respectively, to apply an electric field across the aerosol-generating material. When the capacitor is discharged, current will flow in opposite directions through the first and second conductive layers 26, 28 and the aerosol-generating material 16.

[0053] While exemplary embodiments have been described in the preceding paragraphs, it should be understood that various modifications may be made to those embodiments without departing from the scope of the appended claims. Thus, the breadth and scope of the claims should not be limited to the above-described exemplary embodiments.

[0054] Any combination of the above-described features in all possible variations thereof is encompassed by the present disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.

[0055] Unless the context clearly dictates otherwise, throughout this specification and the claims, the words "comprises," "comprising," and the like are to be construed in an inclusive sense, i.e., "including but not limited to," rather than in an exclusive or exhaustive sense.

Claims

1. An aerosol generation system (1), comprising: an aerosol-generating material (16) having a first outer surface (16a) and a second outer surface (16b) generally opposite the first outer surface (16b); a first non-conductive layer (18a) adjacent the first outer surface (16a), the first non-conductive layer (18a) having an inner surface and an outer surface; a second non-conductive layer (18b) adjacent said second outer surface (16b); a first electrode (8) adjacent to said first non-conductive layer (18a); a second electrode (10) adjacent to the second non-conductive layer (18b); the aerosol-generating material (16) and the first and second non-conductive layers (18a, 18b) are part of an aerosol-generating article (2); The aerosol-generating article (2) further comprises a first conductive layer (26) positioned between the first outer surface (16a) of the aerosol-generating material (16) and the inner surface of the first non-conductive layer (18a). Aerosol generation system (1).

2. 2. The aerosol generating system (1) of claim 1, wherein the second non-conductive layer (18b) has an inner surface and an outer surface, and the aerosol-generating article (2) further comprises a second conductive layer (28) positioned between the second outer surface (16b) of the aerosol-generating material (16) and the inner surface of the second non-conductive layer (18b).

3. 3. The aerosol generating system (1) of claim 1 or claim 2, wherein the aerosol-generating material (16) is part of an aerosol precursor section (12) of the aerosol-generating article (2), the aerosol-generating article (2) further comprising a cooling section (14) at a proximal end, and the first and second electrodes (8, 10) do not overlap with the cooling section (14).

4. The aerosol generating system (1) of any one of claims 1 to 3, wherein the first and second electrodes (8, 10) are part of an aerosol generating device (6) adapted to receive the aerosol generating article (2) in use, and the aerosol generating device (6) further comprises a circuit (24) electrically connected between the first and second electrodes (8, 10), the circuit (24) comprising a power source and a switching device.

5. An aerosol-generating system (1) according to any one of claims 1 to 4, wherein the aerosol-generating material (16) comprises tobacco material.

6. The aerosol-generating system (1) according to any one of claims 1 to 5, wherein the aerosol-generating material (16) is electrically conductive.

7. The aerosol generating system (1) according to any one of claims 1 to 6, wherein the aerosol generating material (16) is approximately rectangular, and the first and second outer surfaces (16a, 16b) are surfaces of the rectangular parallelepiped that have the largest surface area.

8. 8. The aerosol generating system (1) of claim 1, wherein the first and second non-conductive layers (18a, 18b) are formed by a wrapper (18) that extends generally around the aerosol-generating material (16).

9. An aerosol-generating article (2), an aerosol-generating material (16) having a first outer surface (16a) and a second outer surface (16b) opposite the first outer surface (16a); a non-conductive wrapper (18) extending generally around the aerosol-generating material (16) and defining a first non-conductive layer (18a) adjacent the first outer surface (16a) and a second non-conductive layer (18b) adjacent the second outer surface (16a); the first non-conductive layer (18a) has an inner surface and an outer surface, and the aerosol-generating article (2) further comprises a first conductive layer (26) positioned between the first outer surface (16a) of the aerosol-generating material (16) and the inner surface of the first non-conductive layer (18a). An aerosol-generating article (2).

10. 10. The aerosol-generating article (2) of claim 9, wherein the second non-conductive layer (18b) has an inner surface and an outer surface, and the aerosol-generating article (2) further comprises a second conductive layer (28) positioned between the second outer surface (16b) of the aerosol-generating material (16) and the inner surface of the second non-conductive layer (18b).

11. 11. The aerosol-generating article (2) according to claim 9 or claim 10, wherein the aerosol-generating material (16) comprises tobacco material.

12. An aerosol-generating article (2) according to any one of claims 9 to 11, wherein the aerosol-generating material (16) is electrically conductive.

13. The aerosol-generating article (2) according to any one of claims 9 to 12, wherein the aerosol-generating material (16) is substantially rectangular, and the first and second outer surfaces (16a, 16b) are surfaces of the rectangular parallelepiped that have the largest surface area.

14. An aerosol generating device (6) adapted to receive, in use, an aerosol-generating article (2) according to any one of claims 10 to 13, the aerosol generating device (6) comprising a first electrode (8) adjacent to the first non-conductive layer (18a) in use, and a second electrode (10) adjacent to the second non-conductive layer (18b) in use.

15. 15. The aerosol generating device (1) of claim 14, further comprising a circuit (24) electrically connected between the first and second electrodes (8, 10), the circuit (24) comprising a power source and a switching device.

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