A CARTRIDGE FOR USE IN AN AEROSOL GENERATING SYSTEM AND AN AEROSOL GENERATING SYSTEM COMPRISING SAID CARTRIDGE

Abstract

A cartridge for use in an aerosol generating system is provided. The cartridge comprises a porous ceramic body (302) having a porosity of between 30% and 65%. The cartridge also comprises a mesh heater (304) coupled with the porous ceramic body, the mesh heater including a plurality of openings, each with a dimension between 50 microns and 200 microns. The mesh heater is a hybrid mesh heater comprising a network of wires and fibers, the fibers having a different material composition than the wires. An aerosol generating system comprising such a cartridge is also provided.

Description

A CARTRIDGE FOR USE IN AN AEROSOL GENERATING SYSTEM AND AN AEROSOL GENERATING SYSTEM COMPRISING SAID CARTRIDGE The invention relates to a cartridge for use in an aerosol generating system. The invention also relates to an aerosol generating system comprising such a cartridge. One type of aerosol-generating system is an electrically operated smoking system. Portable, electrically operated smoking systems consisting of an aerosol-generating device comprising a battery and electronic control circuitry, and a cartridge comprising a supply of aerosol-forming substrate and an electrically operated vaporizer, are known. A cartridge comprising both a supply of aerosol-forming substrate and a vaporizer is sometimes referred to as a cartomizer. The vaporizer typically comprises a coil of heating wires wound around an elongated wick soaked in a liquid aerosol-forming substrate. The cartridge portion typically comprises not only the supply of aerosol-forming substrate and an electrically operated vaporizer, but also a mouthpiece, through which the user draws the aerosol into their mouth during use. However, producing these cartridges can be relatively expensive. This is because manufacturing the wick and coil assembly can be challenging. Furthermore, the electrical contacts between the heating wire coil and the electrical contacts through which current is supplied from the device must be handled delicately during manufacturing. Additionally, these cartridges include a nozzle to protect the delicate wick and coil unit during shipping. The inclusion of a complete, solid nozzle in each cartridge results in a high material cost per cartridge. It would be advantageous to provide a cartridge for use in an aerosol generating system that is easy to produce, inexpensive, and robust. It would also be advantageous to provide a cartridge that can generate aerosols more efficiently than known cartridges. Finally, it would be advantageous to provide an aerosol generating system that incorporates such a cartridge. According to this description, a cartridge is provided. The cartridge may be suitable for use in an aerosol generating system. The cartridge may comprise a porous ceramic body. The porous ceramic body may have a porosity of between 30% and 65%. The cartridge may comprise a mesh heater. The mesh heater may be coupled to the porous ceramic body. The mesh heater may include a plurality of openings. Each of the openings may have a dimension between 50 microns and 200 microns. According to a first embodiment of the present invention, a cartridge is provided for use in an aerosol generating system. The cartridge comprises a porous ceramic body having a porosity of between 30% and 65%. The cartridge comprises a mesh heater coupled with the porous ceramic body. The mesh heater includes a plurality of openings, each opening having a dimension between 50 microns and 200 microns. According to a second embodiment of the present invention, a cartridge is provided for use in an aerosol generating system. The cartridge comprises a porous ceramic body and a mesh heater coupled with the porous ceramic body. The mesh heater is a hybrid mesh heater comprising a network of wires and fibers, the fibers having a different material composition than the wires. In the second type of cartridge, the porous ceramic body can have a porosity of between 30% and 65%. The mesh heater can include a plurality of openings. Each opening can have a dimension between 50 microns and 200 microns. The characteristics described below in relation to a cartridge are applicable to the cartridge of the first mode and the cartridge of the second mode. During use, the mesh heater can heat a liquid aerosol-forming substrate. The mesh heater can heat the liquid substrate to form an aerosol, or a vapor that subsequently forms an aerosol. Advantageously, the mesh heater can provide efficient aerosol generation. The porosity of the porous ceramic body allows it to contain a liquid aerosol-forming substrate. The porous ceramic body can contain, or can be configured to contain, at least 0.05, 0.1, 0.2, 0.5, or 1 ml of the liquid aerosol-forming substrate. Each opening has a dimension between 50 microns and 200 microns. The aerosol-forming liquid substrate can be drawn into the openings of the mesh heater. The aerosol-forming liquid substrate can be drawn into the openings of the mesh heater from the porous ceramic body. The aerosol-forming liquid substrate can be drawn into the openings of the mesh heater by capillary action, or absorption. Advantageously, this can improve the transport of the aerosol-forming liquid substrate, for example, from the porous ceramic body to the openings of the mesh heater. The mesh heater may comprise an arrangement of openings joined by solid material, for example, wires. Each opening of the mesh heater can act as a capillary channel, thereby drawing the aerosol-forming liquid substrate into the opening. The aerosol-forming liquid substrate can be drawn into the openings by capillary action, or absorption. Therefore, each opening of the mesh heater can be substantially filled by the aerosol-forming liquid substrate. This may not be the case if, for example, larger openings are present. If larger openings are present, the aerosol-forming liquid substrate may form only a thin layer on the solid material joining each opening. The substantially complete filling of the openings by the aerosol-forming liquid substrate contributes to the improved efficiency of aerosol generation in the present invention. Advantageously, the inventors have found that the porous ceramic body has a porosity between 30% and 65%, and the openings in the mesh heater, each with dimensions between 50 and 200 microns, allow for particularly efficient transport of the aerosol-forming liquid substrate through the porous ceramic body and into the mesh heater openings, and for particularly efficient aerosol generation upon heating the mesh heater. Beyond mere theory, it is believed that there is a degree of synergy between the porous ceramic body, with its porosity between 30% and 65%, and the openings in the mesh heater, which have dimensions between 50 and 200 microns, that provides such efficient transport of the aerosol-forming liquid substrate. As used in this description, the term “aerosol” refers to a dispersion of solid particles, liquid droplets, or a combination of solid particles and liquid droplets in a gas. The aerosol may be visible or invisible. It may include vapors of substances that are normally liquid or solid at room temperature, as well as solid particles, liquid droplets, or a combination of solid particles and liquid droplets. As used herein, the term “aerosol-forming substrate” refers to a substrate capable of releasing volatile compounds that can form an aerosol. The volatile compounds can be released by heating or burning the aerosol-forming substrate. The aerosol-forming substrate may comprise nicotine. The aerosol-forming substrate may comprise plant-based material. The aerosol-forming substrate may comprise homogenized plant-based material. The aerosol-forming substrate may comprise tobacco. The aerosol-forming substrate may comprise a tobacco-containing material. The tobacco-containing material may contain volatile tobacco-flavored compounds. These compounds may be released from the aerosol-forming substrate upon heating. The aerosol-forming substrate may comprise a homogenized tobacco material. The aerosol-forming substrate may comprise other additives and ingredients, such as flavorings. As used in this description, the term “dimension of an opening” refers to a dimension measured between two opposite surfaces of an opening. Therefore, when an opening is bounded by wires, for example, the dimension of the opening does not include the thickness of the wires. The dimension may pass through the centroid of the opening's cross-section. For example, when the opening has a substantially square cross-section, the dimension of the opening may be the side length of the square. When the opening has a substantially circular cross-section, the dimension of the opening may be the diameter of the circle. When the opening has a substantially rectangular cross-section, the dimension of the opening may be either the longer or the shorter side length of the rectangle.When the opening has an irregular cross-section, the opening dimension can be the average opening dimension. The dimensions of the openings mentioned in this description were measured using a microscope, although any suitable method could be used. As used in this description, the term “porosity” refers to a measure, expressed as a percentage, of the volume of accessible pores, or void space, of a body divided by the total volume of the body. The porosities mentioned in this description were measured by mercury intrusion porosimetry. Pores of varying shapes and sizes may be present in the porous ceramic body. The pore size distribution is defined as the statistical distribution of the diameter of the largest sphere that can fit within a pore at a given point. As used herein, the term “average pore size” refers to the mean of this pore size distribution. The pore sizes mentioned herein were obtained using mercury intrusion porosimetry. As used herein, the term “mesh heater” refers to a heater comprising an arrangement of heatable solid material. The solid material is arranged to have a plurality of openings extending through it. The mesh heater may comprise, for example, a wire mesh or a perforated sheet. The mesh heater may be heated by any suitable method. For example, the mesh heater, or parts thereof, may be heated resistively or inductively. κζηρηη / ζζηζ / Ε / γίΛΐ As used in this description, the term “capillary action” refers to the ability of a liquid to flow in a narrow space without the aid of, or even in opposition to, external forces such as gravity. The effect of capillary action, or absorption, can be seen in the contraction of liquids in thin tubes and porous materials. As used in this description, the term “bulk aerosol-forming liquid substrate travel direction” refers to a net travel direction of the aerosol-forming liquid substrate. As used in the present description, the term “planar” is used to mean substantially two-dimensional. A planar component may extend in a first direction and a second direction perpendicular to the first direction at least two, five, or ten times more than in a third direction perpendicular to the first and second directions. As used in this description, the term “planar” refers to a substantially two-dimensional collector. Therefore, a planar mesh heater may extend in two dimensions along a surface substantially more than in a third dimension. The dimensions of the planar mesh heater in the two dimensions within the surface may be at least 2, 5, or 10 times larger than in the third dimension, normal to the surface. An example of a substantially planar mesh heater is a structure between two substantially parallel surfaces, where the distance between these two imaginary surfaces is substantially smaller than the extension within the surfaces. In some embodiments, the substantially planar mesh heater is planar. In other embodiments, the substantially planar mesh heater is curved along one or more dimensions, for example, forming a dome or bridge shape.In some versions, the substantially flat mesh heater can be coupled with a porous ceramic body surface. As used in this description, the term “heating unit” refers to the mesh heater and the porous ceramic body of the cartridge. As used in this description, the term “average” refers to an unweighted numerical average unless otherwise specified. Therefore, the “average” diameter of five wires will be equal to one-fifth of the sum of the diameters of the five wires. The porous ceramic body has a porosity of between 30% and 65%. The porous ceramic body may have a porosity lower than 60%, 55%, 50%, or 45%. Alternatively or additionally, the porous ceramic body may have a porosity higher than 35%, 40%, or 45%. For example, the porous ceramic body may have a porosity of between 30% and 60%, or 30% and 55%, or 30% and 50%, or 35% and 65%, or 35% and 60%, or 35% and 55%, or 35% and 50%, or 40% and 65%, or 40% and 60%, or 40% and 55%. The porous ceramic body can be configured to deliver a specific flow rate of aerosol-forming liquid substrate to the mesh heater during operation. For example, the porous ceramic body can be configured to deliver at least 0.2, 0.5, or 1 microliter per second of aerosol-forming liquid substrate to the mesh heater during operation. Alternatively, the porous ceramic body can be configured to deliver less than 3, 5, or 10 microliters per second of aerosol-forming liquid substrate to the mesh heater during operation. Finally, the porous ceramic body can be configured to deliver between 1 and 3 microliters per second of aerosol-forming liquid substrate to the mesh heater during operation. The term “porous ceramic body” can refer to a portion or the entirety of a ceramic component. For example, the term porous ceramic body can refer only to a portion of a ceramic component in which the aerosol-forming liquid substrate is contained or conveyed to the mesh heater. Each of the mesh heater openings can have a dimension of between 50 and 150 microns, or between 50 and 100 microns, or between 60 and 80 microns, or around 70 microns. During use, the aerosol-forming liquid substrate can be drawn into the mesh heater openings from the porous ceramic body. The aerosol-forming liquid substrate can be drawn into the mesh heater openings by capillary action. The mesh heater can be substantially flat. Advantageously, a flat or planar mesh heater can be easily handled during manufacturing and can provide a robust heating unit construction. During use, the travel direction of the bulk aerosol-forming liquid substrate can be substantially perpendicular to a plane of the mesh heater. This can advantageously improve the transport of the aerosol-forming liquid substrate toward the mesh heater openings. Part or all of the mesh heater may be substantially parallel to a first surface of the porous ceramic body. Advantageously, this can improve the transport of the aerosol-forming liquid substrate from the pores in the porous ceramic body, for example, from the pore openings on the first surface of the porous ceramic body, into the mesh heater openings. Rznpnn / zznz / E / YiAi The mesh heater, or a portion thereof, may be one or more of the following: adjacent to, fixed to, secured to, coupled with, or attached to a porous ceramic body or the first surface of the porous ceramic body. For example, the mesh heater, or a portion thereof, may be incorporated into the porous ceramic body. When the mesh heater, or a portion thereof, is incorporated into the porous ceramic body, the first surface may not be an external surface of the porous ceramic body. As used herein, the term “coupled with” may mean fixed to, secured to, attached to, or bonded to. The mesh heater can be reversibly coupled to the porous ceramic body. It may be possible to couple the mesh heater to the porous ceramic body and then decouple it from the mesh heater. Alternatively, the mesh heater can be irreversibly coupled to the mesh heater. When coupled with the porous ceramic body, the position of the mesh heater can be fixed. When coupled with the porous ceramic body, the mesh heater can be adjacent to the porous ceramic body, or in contact with it. The mesh heater can be attached to the porous ceramic body. The mesh heater can be attached to the porous ceramic body by any suitable method. The mesh heater can be attached to the porous ceramic body by one or more of the following: one or more solder points, one or more mechanical fasteners such as clips or bolts, and a ceramic coating layer. The mesh heater can be incorporated into the porous ceramic body. The porous ceramic body may comprise a second surface substantially opposite the first surface. During use, the aerosol-forming liquid substrate may travel from the second surface to the first surface through the porous ceramic body. The aerosol-forming liquid substrate may travel through the porous ceramic body by capillary action. Alternatively or additionally, an airflow beyond, through, or around the porous ceramic body or the mesh heater may induce a local pressure gradient to the porous ceramic body, which aids the aerosol-forming liquid substrate to travel through the porous ceramic body. The porous ceramic body can absorb, or be configured to absorb, the aerosol-forming liquid substrate. For example, the porous ceramic body can absorb, or be configured to absorb, at least 0.01, 0.02, 0.05, 0.1, or 0.5 ml of aerosol-forming liquid substrate. The cartridge may include a liquid aerosol substrate storage component for storing the liquid aerosol substrate. The liquid aerosol substrate storage component may be in fluid communication with the porous ceramic body, for example, the second surface of the porous ceramic body. The aerosol-forming liquid substrate storage component may comprise an aerosol-forming liquid substrate reservoir or tank. The porous ceramic body may be in fluid communication with, or in contact with, the aerosol-forming liquid substrate reservoir. The aerosol-forming liquid substrate storage component may comprise a material soaked with the aerosol-forming liquid substrate. This component may be positioned to deliver the liquid to the porous ceramic body. The storage component of the aerosol-forming liquid substrate may have a fibrous or spongy structure. The storage component of the aerosol-forming liquid substrate may comprise a capillary material. The storage component of the aerosol-forming liquid substrate may comprise an array of capillaries. For example, the storage component of the aerosol-forming liquid substrate may comprise one or more of a plurality of fibers, threads, or thin cylindrical tubes. The fibers, threads, or tubes may generally be aligned to carry the liquid toward the porous ceramic body. The storage component of the aerosol-forming liquid substrate may comprise a sponge-like or foam-like material. The structure of the storage component of the aerosol-forming liquid substrate may form a plurality of small holes or tubes, through which the liquid can be transported by capillary action. The storage component of the aerosol-forming liquid substrate may comprise any suitable material or combination of materials. Examples of suitable materials include sponge or foam materials, ceramic or graphite-based materials in the form of sintered fibers or powders, foamed metal or plastic materials, fibrous materials such as spun or extruded fibers like cellulose acetate, polyester, or bonded fibers of polyolefin, polyethylene, terylene, or polypropylene, nylon fibers, or ceramics. The storage component of the aerosol-forming liquid substrate may have any suitable capillarity and porosity to accommodate different physical properties of the liquid. κζηρηη / ζζηζ / Ε / γίΛΐ The cartridge may comprise a liquid aerosol substrate storage component that can be soaked with a liquid aerosol substrate. The liquid aerosol substrate storage component may be in contact with the porous ceramic body. The porous ceramic body may comprise a first portion. The first portion of the porous ceramic body may be located between the liquid aerosol substrate storage component and the mesh heater. The first portion of the porous ceramic body may comprise a first surface and a second surface. The second surface may be opposite the first surface. The mesh heater may be coupled with the first surface. The liquid aerosol substrate storage component may be in contact with the second surface. The mesh heater may comprise a metal, for example, a steel such as stainless steel. The mesh heater area can be less than 50, 40, or 30 mm². This may allow the mesh heater to be incorporated into a portable system. The mesh heater may comprise a wire network. The wires may be interwoven. The mesh heater may comprise a woven or non-woven wire mesh. The wires may be electrically conductive. The wires can be in a single plane. The mesh heater can be planar. A planar mesh heater is easy to handle during manufacturing and provides a robust construction. The openings can be defined by wires. The wires can have a substantially circular, square, rectangular, hexagonal, or irregular cross-section. The wires can be individually formed and woven together. They can also be formed by etching a sheet-like material, such as a foil. This can be particularly advantageous when the mesh heater comprises an array of parallel wires. Alternatively, the wires can be stamped from an electrically conductive sheet, such as stainless steel. The mesh heater, or the wires, may comprise or be formed from any material with suitable electrical and mechanical properties. Suitable materials include, but are not limited to: semiconductors such as doped ceramics, “electrically conductive” ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys, and composite materials made from a ceramic material and a metallic material. Such composite materials may comprise doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbides. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals.Examples of suitable metal alloys include stainless steel, constantan, alloys containing nickel, cobalt, chromium, aluminum-titanium-zirconium, hafnium, niobium, molybdenum, tantalum, tungsten, tin, gallium, manganese, and iron, and superalloys based on nickel, iron, cobalt, stainless steel, Timetal®, iron-aluminum alloys, and iron-manganese-aluminum alloys. Timetal® is a registered trademark of Titanium Metals Corporation. The wires may be coated with one or more electrical insulators. Preferred materials for the mesh heater or wires may be 304, 316, 304L, and 316L stainless steel, and graphite. Additionally, the mesh heater or wires may comprise combinations of the above materials. A combination of materials may be used to improve resistance control of the mesh heater.For example, materials with high resistivity can be combined with materials with low resistivity. This can be advantageous if one of the materials is more beneficial from other perspectives, such as price, machinability, and other physical and chemical parameters. The mesh heater may comprise at least one wire made from a first material and at least one wire made from a second material different from the first. This is beneficial for electrical or mechanical reasons. For example, one or more of the wires may be formed from a material whose resistance varies significantly with temperature, such as an iron-aluminum alloy. This allows for a measurement of the wires' resistance, which is used to determine the temperature or temperature changes. This can be used in a puff detection system and to control the heater's temperature to maintain it within a desired range. Sudden temperature changes can also be used as a means of detecting changes in airflow past the mesh heater resulting from a user taking a puff into the system. A mesh heater can consist of two or more types of wires formed into a wire mesh. The two types of wires can have different resistivities. Wires with higher resistivity can be oriented in the direction of the electric current flow, for example, wires made of a nickel-chromium alloy. Wires with lower resistivity can be arranged substantially perpendicular to the wires with higher resistivity. For example, the low-resistance wires can be stainless steel wires. Advantageously, the relatively cheaper, low-resistance wires form the support for the high-resistance wires. Furthermore, high-resistance wires are typically less malleable than stainless steel wires and therefore cannot be easily manufactured as thin wires. κζηρηη / ζζηζ / Ε / γίΛΐ Alternatively, the mesh heater may comprise a carbon yarn fabric. Advantageously, a carbon yarn fabric is typically more flexible than a metal mesh. The wires may have an average diameter of at least 10, 16, 17, or 30 microns. The wires may have an average diameter less than 100, 90, 80, 70, 60, 50, 40, or 30 microns. Preferably, the wires may have an average diameter between 15 and 30 microns, or 15 and 20 microns, for example, around 16 or 17 microns. Each wire may have a minimum thickness of at least 10, 16, 17, or 30 microns. Each wire may have a minimum thickness less than 100, 90, 80, 70, 60, 50, 40, or 30 microns. The mesh heater may be a hybrid mesh heater. As used herein, the term “hybrid mesh heater” refers to a mesh heater comprising at least one wire and at least one fiber. The mesh heater may comprise a network of wires and fibers. The characteristics and properties of the wires described above apply equally to the wires of the hybrid mesh heater. The fibers can have a different material composition than the wires. The wires and fibers can be interwoven. Therefore, the mesh heater can comprise a woven wire and a fiber mesh. The fibers can have an average diameter between 80% and 120% of the average diameter of the wires. The wires and fibers can have substantially identical average diameters. The wires can be substantially perpendicular to the fibers. The fibers may have an average diameter of at least 10, 16, 17, or 30 microns. The fibers may have an average diameter less than 100, 90, 80, 70, 60, 50, 40, or 30 microns. Preferably, the fibers may have an average diameter between 15 and 30 microns, or 15 and 20 microns, for example, around 16 or 17 microns. The fibers may comprise glass fibers. The fibers may comprise rayon fibers. Each fiber may have a minimum thickness of at least 10, 16, 17, or 30 microns. Each fiber may have a minimum thickness less than 100, 90, 80, 70, 60, 50, 40, or 30 microns. The mesh heater thickness can be at least 30, 40, or 48 microns. When the mesh heater comprises wires, or wires and fibers, the mesh heater thickness can be approximately three times the average diameter of the wires or fibers. For example, the mesh heater thickness can be between 2.5 and 3.5 times the average diameter of the wires or fibers. The mesh heater thickness can be less than 300, 250, 200, 150, or 100 microns. The mesh heater thickness can be between 45 and 100, or 45 and 80, or 45 and 60 microns. The mesh heater may comprise a sheet. The sheet may be metallic. The sheet may comprise a metal such as stainless steel. The sheet may comprise a plurality of openings. The sheet may be perforated. The plurality of openings may comprise perforations in the sheet. The sheet may comprise a heating track, or a heating track may be deposited on the sheet. As used herein, the term “heating track” refers to a track, path, or section of a material configured to heat up during use. For example, during use, a current may pass through the heating track to resistively heat the heating track. In this case, the heating track may comprise an electrically conductive material.Alternatively, the heating track may comprise a susceptor material and, during use, the heating track may be inductively heated. The mesh heater may be coupled to the porous ceramic body, or the first surface of the porous ceramic body, over substantially the entirety of one face of the mesh heater. The mesh heater may be in contact with the porous ceramic body or the first surface of the porous ceramic body. The mesh heater may be in contact with the porous ceramic body, or the first surface of the porous ceramic body, over substantially the entirety of one face of the mesh heater. The mesh heater may be coupled to the porous ceramic body, or the first surface of the porous ceramic body, such that at no point is there a separation between the porous ceramic body and the mesh heater of more than 500, 300, 100, 75, 50, or 25 microns.All points on the mesh heater can be within 500, 300, 100, 75, 50, or 25 micrometers of at least one point on the porous ceramic body, or on the first surface of the porous ceramic body. Advantageously, minimizing any gap between the mesh heater and the porous ceramic body can improve the transport of the aerosol-forming liquid substrate from the porous ceramic body to the mesh heater openings. The porous ceramic body can be made of a material with a relatively low linear coefficient of thermal expansion, for example, a linear coefficient of thermal expansion at 25 degrees Celsius that is less than 30, 20, or 10 x 10⁶ m / (m K). Advantageously, a lower coefficient of thermal expansion can reduce the risk of particles breaking off the porous ceramic body when it is heated by the mesh heater. When the mesh heater is in contact with the porous ceramic body, this risk can be particularly high at the contact points between the mesh heater and the porous ceramic body. The porous ceramic body can be made of a material with a linear coefficient of thermal expansion at 25 degrees Celsius that is between 30% and 300% of the linear coefficient of thermal expansion at 25 degrees Celsius of the mesh heater material. Advantageously, this can reduce the risk of the porous ceramic body particles breaking off when heated by the mesh heater. The porous ceramic body may comprise one or more of steatite, alumina, and zirconia. Advantageously, these materials are chemically stable and have relatively low coefficients of thermal expansion. The porous ceramic body may comprise pores having an average pore size of less than 40, 30, 20, 10, or 8 microns. The porous ceramic body may comprise pores having an average pore size of more than 2.5, 5, 10, or 20 microns. The porous ceramic body may comprise pores having an average pore size of between 2.5 and 40 microns, or 2.5 and 30 microns, or 2.5 and 20 microns, or 2.5 and 10 microns, or 2.5 and 8 microns, or 5 and 40 microns, or 5 and 30 microns, or 5 and 20 microns, or 5 and 10 microns, or 10 and 40 microns, or 10 and 30 microns, or 10 and 20 microns, or 20 and 40 microns, or 20 and 30 microns, or 30 and 40 microns. A preferred porous ceramic body may have a porosity of between 30% and 60% and have pores with an average pore size of between 5 and 30 microns. A particularly preferred porous ceramic body may have a porosity of between 40% and 60% and have pores with an average pore size of between 5 and 10 microns. Another particularly preferred porous ceramic body may have a porosity of between 30% and 40% and have pores with an average pore size of between 20 and 30 microns. The porous ceramic body may comprise a first portion and a projection. The projection may be located on a periphery of the first portion. The projection may extend around substantially the entire periphery of the first portion. The projection may extend substantially perpendicularly from a surface of the first portion. Advantageously, the projection may allow the porous ceramic body to withstand greater forces during manufacturing and assembly without breaking. The first portion may comprise a length, a width perpendicular to the length, and a thickness perpendicular to both the length and the width. The length and width may be at least two, three, or five times the thickness. The first portion may have a substantially circular cross-section. The first portion may have a diameter and a thickness. The diameter may be at least two, three, or five times the thickness. The first portion can be at least 1, 1.5, 2, or 2.5 mm thick. Advantageously, a greater thickness can improve the strength of the first portion of the porous ceramic body. Alternatively, the first portion can be less than 6, 5, or 4 mm thick. Advantageously, a smaller thickness can improve the absorption capacity of the first portion, thus enhancing the transport of the aerosol-forming liquid substrate through it. Therefore, the first portion can be between 1 and 6 mm, 1 and 5 mm, 1.5 and 5 mm, or 1.5 and 4 mm thick. The projection can have a width of at least 1, 1.5, 2, or 2.5 mm. The projection can also have a width less than 6, 5, or 4 mm. Therefore, the projection can have a width between 1 and 6 mm, or 1 and 5 mm, or 1.5 and 5 mm, or 1.5 and 4 mm. The width of the projection can be between 50% and 150% of the thickness of the first portion. The first portion of the porous ceramic body can be positioned between the aerosol-forming liquid substrate storage component and the mesh heater. This first portion comprises a first surface and a second surface. The second surface can be opposite the first surface. The mesh heater can be coupled with the first surface. The aerosol-forming liquid substrate storage component can be in contact with the second surface. A projection can extend from the second surface. This projection can surround the aerosol-forming liquid substrate storage component. The porous ceramic body may comprise a channel extending through it. The first portion of the porous ceramic body may comprise the channel. The channel may extend through the first portion. The channel may extend substantially in one thickness direction of the first portion. The mesh heater may be substantially flat or planar, and the channel may extend substantially perpendicular to a plane of the mesh heater. The channel may have a diameter of at least 300, 400, or 500 microns. The channel may have a diameter less than 800, 700, or 600 microns. Advantageously, the channel may increase the porosity of the porous ceramic body. This may allow the porous ceramic body to hold more aerosol-forming liquid substrate. In addition, the channel may improve the absorption capacity of the porous ceramic body.Therefore, the channel can improve the transport of the aerosol-forming liquid substrate through the porous ceramic body. κζηρηη / ζζηζ / Ε / γίΛΐ The mesh heater can be attached to the porous ceramic body by means of one or more solder points. The solder point or points can be made of silver or tin. The mesh heater can be attached to the porous ceramic body by: providing one or more metal segments between the porous ceramic body and the mesh heater (for example, by applying the metal segment(s) to the porous ceramic body, or by coating the mesh heater with the metal); positioning the attached mesh heater with the porous ceramic body; melting the metal segment(s), optionally while forcing the mesh heater and the porous ceramic body together; and solidifying the metal segment(s). As the metal segment(s) solidify, they bond the porous ceramic body to the mesh heater. The mesh heater can be attached to the porous ceramic body by: providing one or more metal segments between the mesh heater and the porous ceramic body (for example, by applying the metal segment(s) to the porous ceramic body, or by coating the mesh heater with the metal); and forcing the mesh heater and the porous ceramic body together, optionally while heating the metal segment(s). The metal segment(s) can adhere the porous ceramic body to the mesh heater. When multiple metal segments are used, these segments can be separated, for example, within the plane of the mesh heater. One or more of the segments may be, or may comprise, a region or portion of metal within the porous ceramic body or the mesh heater. Therefore, there may be multiple separate metal regions or portions within the porous ceramic body or the mesh heater, or within both. Therefore, when attaching the mesh heater to the porous ceramic body as described above, the cartridge may include a metal segment between the porous ceramic body and the mesh heater. This metal segment may be made of silver or tin. It should be noted, however, that the cartridge may include the metal segment between the porous ceramic body and the mesh heater for another reason. The metal segment can attach the porous ceramic body to the mesh heater. The metal segment can be made of silver or tin. The mesh heater, or a portion thereof, may comprise a full or partial metallic coating. The metallic coating may comprise tin or silver. This may be the case where the metal segment(s) are applied when coating the mesh heater with metal. κζηρηη / ζζηζ / Ε / γίΛΐ The mesh heater can be attached to the porous ceramic body by: positioning the mesh heater attached to the porous ceramic body; and depositing a coating layer of a second ceramic onto the mesh heater such that at least part of the mesh heater is between the porous ceramic body and the coating layer of the second ceramic. The porous ceramic body, or the coating layer of the second ceramic, or both the porous ceramic body and the coating layer of the second ceramic, can then be sintered. Alternatively or additionally, the porous ceramic body, or the coating layer of the second ceramic, or both the porous ceramic body and the coating layer of the second ceramic, can be sintered before the coating layer of the second ceramic is deposited onto the mesh heater. The characteristics and properties of the porous ceramic body can also be applied to the coating layer of the second ceramic. For example, material-related characteristics and properties, such as pore size and porosity, can all be applied to the coating layer of the second ceramic. Therefore, by attaching the mesh heater to the porous ceramic body as described above, the mesh heater can be positioned between the porous ceramic body and a coating layer of a second ceramic. It should be noted, however, that the cartridge may comprise the coating layer of the second ceramic for another reason. The coating layer of the second ceramic may comprise a ceramic material. The porous ceramic body may also comprise a ceramic material. Therefore, both the porous ceramic body and the coating layer of the second ceramic may comprise one or more of alumina, steatite, and zirconia. The coating layer of the second ceramic can be less than 5000, 1000, 500, or 200 microns thick. The coating layer of the second ceramic can be at least 10, 100, 500, or 1000 microns thick. Therefore, the coating layer of the second ceramic can be between 500 and 5000 microns thick, for example, between 1000 and 2000 microns. The coating layer of the second ceramic can be in contact with the mesh heater. The coating layer of the second ceramic can be in contact with the porous ceramic body. The mesh heater can be attached to the porous ceramic body via the coating layer of the second ceramic. The coating layer of the second ceramic can cover less than 80%, 65%, or 50% of the mesh heater surface. This can improve aerosol generation compared to a second ceramic coating layer that covers a larger proportion of the mesh heater surface. The cartridge may include an air inlet. The cartridge may include an air outlet. The air inlet may be in fluid communication with the air outlet. The mesh heater may be arranged downstream of the air inlet. The mesh heater may be arranged upstream of the air outlet. The cartridge may include a nozzle. The nozzle may be, or may include, the air outlet. During use, when the cartridge is attached to an aerosol-generating device, a user may take a breath at the cartridge nozzle. This may cause air to flow through the air inlet, then into, through, past, or through the mesh heater, and then through the air outlet. The cartridge may comprise first and second electrical contacts electrically connected to the mesh heater. The electrical contacts may comprise one or more of tin, silver, gold, copper, aluminum, steel such as stainless steel, phosphor bronze, tin alloyed with antimony, tin alloyed with zirconium, tin alloyed with bismuth, or tin alloyed with other components that improve resistance to organic acids. Electrical contacts can be attached directly to the wires of the mesh heater. Electrical contacts can also be placed between the wires and the porous ceramic body. For example, the contacts can be formed from tin or silver that is plated or otherwise bonded to the porous ceramic body. The contacts may bond more easily to the wires than to the porous ceramic body. Alternatively, the electrical contacts can be integrated into the wires. For example, the mesh heater can be formed by etching an electrically conductive sheet to provide multiple wires between two electrical contacts. The electrical contacts can be configured to form an electrical connection with the corresponding electrical contacts on an aerosol generating device when the cartridge is attached to the device. According to a third embodiment of the present description, an aerosol generating system is provided comprising an aerosol generating device and a cartridge. The cartridge may be a cartridge according to the first embodiment. The cartridge may be a cartridge according to the second embodiment. The aerosol generating device can be configured to couple with the cartridge. For example, the aerosol generating device can be configured to couple to and detach from the cartridge. The aerosol generating device can be configured to couple to and detach from the cartridge by means of a press-fit connection, corresponding screw threads, or any other suitable means. The aerosol generating device can be configured to receive at least a portion of the cartridge. For example, the aerosol generating device can comprise a chamber configured to receive at least a portion of the cartridge. The aerosol generating device may include an air inlet. The aerosol generating device may include an air outlet. The air outlet of the aerosol generating device may be in fluid communication with the air inlet of the cartridge. The aerosol generating device may include a power supply, such as a battery. When the cartridge is attached to the device, the power supply can be configured to provide power to the mesh heater, for example, to resistively heat the mesh heater. The power supply can be electrically connected to the first and second electrical contacts of the device. These first and second electrical contacts can be configured to form an electrical connection with the corresponding electrical contacts on the cartridge when the cartridge is coupled to the device. The mesh heater can be configured to heat resistively. The mesh heater can be, or may comprise, electrically resistive wires or a track connected to the electrical contacts on the cartridge. The wires or track can be heated as the power supply passes a current through the wires or track. Therefore, when the cartridge is coupled to the aerosol generating device, the power supply in the aerosol generating device can be configured to supply power to the mesh heater.In other words, the power supply can pass a current through the mesh heater, or wires or a track of the mesh heater, and resistively heat the mesh heater. The cartridge or aerosol generating device may comprise an inductor, for example an induction coil. The mesh heater may be, or may comprise, a susceptor material. The power supply can be configured to pass a current through the inductor, causing it to generate a fluctuating electromagnetic field. This, in turn, can generate eddy currents and hysteresis losses in the susceptor material. This can cause the susceptor material to heat up. Therefore, the power supply and inductor can be configured to inductively heat the mesh heater. The susceptor material may be, or may comprise, any material that can be induction heated to a temperature sufficient to generate an aerosol from the aerosol-forming substrate. Preferred susceptor materials may be heated to a temperature in excess of 100, 150, 200, or 250 degrees Celsius. Preferred susceptor materials may comprise a metal or carbon. A preferred susceptor material may comprise a ferromagnetic material, for example, ferritic iron, or a ferromagnetic steel or stainless steel. A suitable susceptor element may be made of, or comprise, aluminum. The preferred susceptor materials may comprise or be formed from 400 series stainless steels, for example grade 410, or grade 420, or grade 430 stainless steel. Different materials will dissipate different amounts of energy when placed within electromagnetic fields that have similar values ​​of frequency and field strength.Therefore, the parameters of the susceptor material, such as material type and size, can be altered to provide a desired energy dissipation within a known electromagnetic field. The inductor can be an induction coil. The induction coil can be located within the cartridge. The induction coil can be arranged around the mesh heater. For example, the induction coil can spiral around the mesh heater. The inductor can be electrically connected to electrical contacts on the cartridge. When the cartridge is coupled with the aerosol generating device, these electrical contacts can be electrically connected to corresponding electrical contacts on the device, which are in turn connected to the device's power supply. Therefore, when the cartridge is coupled with the device, the device's power supply can be configured to pass a current through the inductor to generate a fluctuating electromagnetic field and thus heat the susceptor material of the mesh heater. The inductor, such as an induction coil, can be located in the aerosol generating device. The inductor can be electrically connected to the power supply. The aerosol generating device can include a chamber to receive at least a portion of the cartridge. The induction coil can be arranged around at least part of this chamber. For example, the induction coil can be rotated around at least part of the chamber. As such, when the cartridge, or a portion thereof, is received in the chamber, the induction coil can be arranged around, or coiled around, the mesh heater. Therefore, when the cartridge is coupled with the device, the device's power supply can be configured to pass a current through the inductor to generate a fluctuating electromagnetic field and thus heat the susceptor material of the mesh heater. The aerosol generating device may include a controller. The controller can be configured to control the power supply. Therefore, the controller can control the heating of the mesh heater. κζηρηη / ζζηζ / Ε / γίΛΐ The following is a non-exhaustive list of non-limiting examples. These examples are set out in clauses. Any one or more of the features in these examples may be combined with one or more features of another example, modality, or aspect described herein. A. A cartridge for use in an aerosol generating system, comprising: a porous ceramic body having a porosity of between 30% and 65%; and a mesh heater coupled with the porous ceramic body, the mesh heater including a plurality of openings, each opening having a dimension between 50 microns and 200 microns. B. A cartridge conforming to clause A, wherein, during use, the aerosol-forming liquid substrate is drawn into the mesh heater openings from the porous ceramic body. C. A cartridge conforming to clause A or B, wherein, during use, the aerosol-forming liquid substrate is drawn into the mesh heater openings by capillary action. D. A cartridge conforming to any of the foregoing clauses, wherein the mesh heater is substantially flat or substantially planar. E. A cartridge conforming to clause D, wherein, during use, a direction of travel of the bulk aerosol-forming liquid substrate is substantially perpendicular to a plane of the mesh heater. F. A cartridge conforming to any of the foregoing clauses, wherein the mesh heater, or a portion thereof, is substantially parallel to a first surface of the porous ceramic body. G. A cartridge conforming to clause F, wherein the mesh heater is attached to the first surface of the porous ceramic body. H. A cartridge conforming to clause F or G, wherein the porous ceramic body comprises a second surface substantially opposite to the first surface. I. A cartridge conforming to clause H, wherein, during use, the aerosol-forming liquid substrate travels in one direction from the second surface to the first surface, for example from the second surface to the first surface. J. A cartridge in accordance with any of the foregoing clauses, wherein the cartridge comprises an aerosol-forming liquid substrate storage component for storing the aerosol-forming liquid substrate. K. A cartridge conforming to clause J, wherein the aerosol-forming liquid substrate storage component is in fluid communication with the porous ceramic body. L. A cartridge in accordance with clause H or I, wherein the cartridge comprises an aerosol-forming liquid substrate storage component for storing the aerosol-forming liquid substrate and the aerosol-forming liquid substrate storage component is in fluid communication with the second surface of the porous ceramic body. M. A cartridge in conformity with any of the foregoing clauses, wherein the mesh heater comprises a metal. N. A cartridge in accordance with clause M, wherein the mesh heater comprises a steel. O. A cartridge in accordance with any of the above clauses, wherein the mesh heater comprises a wire network. P. A cartridge in accordance with clause O, wherein the mesh heater comprises a woven wire mesh. Q. A cartridge conforming to any of the foregoing clauses, wherein the mesh heater is a hybrid mesh heater comprising a network of wires and fibers, and the fibers have a different material composition than the wires. R. A cartridge in accordance with clause Q, wherein the wires comprise a metal. S. A cartridge conforming to clause R, wherein the wires comprise a steel. T. A cartridge conforming to any of clauses Q to S, wherein the wires are substantially perpendicular to the fibers. U. A cartridge conforming to any of clauses Q to T, wherein the mesh heater comprises a wire mesh and woven fiber. V. A cartridge conforming to any of clauses Q to U, wherein the fibers have an average diameter between 80% and 120% of an average diameter of the wires. W. A cartridge conforming to any of clauses Q to V, wherein the fibers have an average diameter of at least 10 microns. X. A cartridge conforming to any of clauses Q to W, wherein the fibers have an average diameter less than 100 microns. Y. A cartridge conforming to any of the QaX clauses, wherein the fibers are glass fibers. Z. A cartridge conforming to any of clauses Q to X, wherein the fibers are rayon fibers. AA. A cartridge conforming to any of clauses O to Z, wherein the wires have an average diameter of at least 10 microns. AB. A cartridge conforming to any of clauses O to AA, wherein the wires have an average diameter less than 100 microns. AC. A cartridge conforming to any of clauses A to N, wherein the mesh heater comprises a sheet. AD. A cartridge conforming to clause AC, wherein the foil is metallic. AE. A cartridge conforming to clause AC or AD, wherein the sheet comprises the plurality of openings. AF. A cartridge conforming to any of clauses AC to AE, wherein the foil is perforated. AG. A cartridge conforming to any of clauses AC to AF, wherein the foil comprises a heating track deposited thereon. AH. A cartridge conforming to any of the foregoing clauses, wherein the mesh heater is substantially flat or substantially planar and a mesh heater thickness is greater than 30 microns. A. A cartridge conforming to any of the foregoing clauses, wherein the mesh heater is coupled to the porous ceramic body over substantially an entire face of the mesh heater. AJ. A cartridge conforming to clause A1, wherein the mesh heater is in contact with the porous ceramic body over substantially the entirety of one face of the mesh heater. AK. A cartridge conforming to any of the foregoing clauses, wherein the porous ceramic body comprises one or more of steatite, alumina, and zircon. AL. A cartridge conforming to any of the foregoing clauses, wherein the porous ceramic body comprises pores with an average pore size between 2.5 microns and 40 microns. AM. A cartridge conforming to any of the foregoing clauses, wherein the porous ceramic body comprises a first portion and a projection. Rznpnn / zznz / E / YiAi AN. A cartridge in accordance with clause AM, wherein the projection is located on a periphery of the first portion. AO. A cartridge conforming to clause AN, wherein the projection extends around substantially the entire periphery of the first portion. AP. A cartridge conforming to any of clauses AM to AO, wherein the projection extends substantially perpendicularly from a surface of the first portion. AQ. A cartridge conforming to any of clauses AM to AP, wherein the first portion comprises a length, a width perpendicular to the length, and a thickness perpendicular to the length and width, and the length and width are at least twice the thickness. AR. A cartridge conforming to any of clauses AM to AP, wherein the first portion has a substantially circular cross-section. AS. A cartridge conforming to clause AR, wherein the first portion has a diameter and a thickness, and the diameter is at least twice the thickness. AT. A cartridge conforming to any of clauses AM to AS, wherein the first portion has a thickness of at least 1.5 mm. AU. A cartridge conforming to any of clauses AM to AT, wherein the first portion is less than 6 mm thick. AV. A cartridge conforming to any of clauses AM to AU, wherein the projection has a width of at least 1.5 mm. AW. A cartridge conforming to any of clauses AM to AV, wherein the projection has a width of less than 6 mm. AX. A cartridge conforming to any of the foregoing clauses, wherein the porous ceramic body comprises a channel extending through it. AY. A cartridge conforming to any of clauses AM to AW, wherein the first portion of the porous ceramic body comprises a channel extending through it. AZ. A cartridge conforming to clause AY, wherein the channel extends substantially in one thickness direction from the first portion. BA. A cartridge conforming to clause AX, AY or AZ, wherein the mesh heater is substantially flat or substantially planar and the channel extends substantially perpendicular to a plane of the mesh heater. BB. A cartridge conforming to any of clauses AX to BA, wherein the channel has a diameter of at least 300 microns. BC. A cartridge conforming to any of clauses AX to BB, wherein the channel has a diameter less than 800 microns. BD. A cartridge conforming to any of the foregoing clauses, wherein the mesh heater is joined to the porous ceramic body by a solder point. BE. A cartridge conforming to clause BD, wherein the solder point comprises silver or tin. BF. A cartridge conforming to any of the foregoing clauses, comprising a metal segment located between the porous ceramic body and the mesh heater. BG. A cartridge conforming to clause BF, wherein the mesh heater is attached to the porous ceramic body by the metal segment. BH. A cartridge conforming to clause BF or BG, wherein the metal segment comprises silver or tin. Bl. A cartridge conforming to any of the foregoing clauses, wherein the mesh heater is located between the porous ceramic body and a coating layer of a second ceramic. BJ. A cartridge in accordance with clause B1, wherein the coating layer of the second ceramic comprises a ceramic material and the porous ceramic body comprises the ceramic material. BK. A cartridge conforming to clause B1 or BJ, wherein the coating layer of the second ceramic is less than 5000 microns thick. BL. A cartridge conforming to clause B1, BJ or BK, wherein the coating layer of the second ceramic has a thickness of at least 10 microns. BM. A cartridge conforming to any of clauses B1 to BL, wherein the coating layer of the second ceramic covers less than 80% of a mesh heater surface. BN. A cartridge conforming to any of clauses B1 to BM, wherein the coating layer of the second ceramic is in contact with the mesh heater. BO. A cartridge conforming to any of clauses B1 to BN, wherein the mesh heater is joined to the porous ceramic body by the coating layer of the second ceramic. BP. A cartridge conforming to any of the foregoing clauses, the cartridge comprising an electrical contact electrically connected to the mesh heater. BQ. A cartridge in accordance with clause BP, wherein the electrical contact comprises tin, silver, gold, copper, aluminum, steel such as stainless steel, phosphor bronze, tin alloyed with antimony, tin alloyed with zirconium, tin alloyed with bismuth, or tin alloyed with other components that improve resistance to organic acids. BR. An aerosol generating system comprising an aerosol generating device and a cartridge in accordance with any of the foregoing clauses. BS. An aerosol generating system in accordance with clause BR, wherein the aerosol generating device is configured to be coupled to the cartridge. BT. An aerosol generating system in accordance with clause BR or BS, wherein the aerosol generating device comprises a power supply configured to supply power to the mesh heater for resistively heating the mesh heater. BU. An aerosol generating system in accordance with clause BR or BS, wherein the aerosol generating device comprises a power supply, and the cartridge or aerosol generating device comprises an inductor, and the power supply and the inductor are configured to inductively heat the mesh heater. Now, examples will also be described with reference to the figures in which: Figure 1 shows a cross-sectional view of an aerosol generating system incorporating a cartridge with a first heating unit; Figure 2 shows a cross-sectional view of the cartridge incorporating the first heating unit; Figure 3 shows a perspective view of the first heating unit; Figure 4 shows a cross-sectional view of the first heating unit; Figure 5 shows a perspective view of a second heating unit; Figure 6 shows a cross-sectional view of the second heating unit; Figure 7 shows a perspective view of a third heating unit; Figure 8 shows a cross-sectional view of the third heating unit; and Figure 9 shows a cross-sectional view of an aerosol generating system incorporating a cartridge with the third heating unit. Figure 1 shows a cross-sectional view of an aerosol generating system 100. The aerosol generating system 100 comprises an aerosol generating device 150 and a cartridge 200. In this example, the aerosol generating system 100 is an electrically operated smoking system. The aerosol generating device 150 is portable and comparable in size to a conventional tobacco or cigarette. The device 150 comprises a battery 152, such as a lithium iron phosphate battery, and a controller 154 electrically connected to the battery 152. The device 150 also comprises two electrical contacts 156, 158 that are electrically connected to the battery 152. This electrical connection is a wired connection and is not shown in Figure 1. The cartridge 200 comprises an air inlet 202, an air outlet 204, and a first heating unit 300. The air inlet 202 is in fluid communication with the air outlet 204. The heating unit 300 is positioned close down of the air inlet 202 and upstream of the air outlet 204. The heating unit 300 comprises a porous ceramic body 302, and a substantially planar mesh heater 304 coupled with the porous ceramic body 302. The 304 mesh heater comprises a hybrid mesh consisting of 306 stainless steel wires and 308 glass fibers. The 306 stainless steel wires are interwoven with, and substantially perpendicular to, the 308 glass fibers. Therefore, the 304 mesh heater comprises a woven hybrid mesh. The 304 mesh heater is attached to the 302 porous ceramic body by two solder points 310, 312. In this example, the solder points 310, 312 are formed from tin, although silver or another suitable material could be used. Each of these solder points 310, 312 is electrically connected to an electrical contact 214, 216 on the cartridge. This electrical connection is a wired connection and is not shown in Figure 1. Through this electrical connection, the 306 stainless steel wires are electrically connected to the electrical contacts 214, 216. The porous ceramic body 302 comprises a number of pores. An aerosol-forming liquid substrate is held within the pores of the porous ceramic body 302. In Figure 1, the aerosol generating device 150 is coupled with the cartridge 200. In this example, the cartridge 200 is coupled with the aerosol generating device 150 by means of protrusions 206, 208 that form a press-fit connection with the corresponding openings 160, 162 in the aerosol generating device 150. The cartridge 200 further comprises an aerosol-forming liquid substrate storage component 288 that is in fluid communication with the porous ceramic body 302. The aerosol-forming liquid substrate storage component 288 is in contact with a first portion 320 of the porous ceramic body 302. The aerosol-forming liquid substrate storage component 288 may be adhered to the porous ceramic body 302 with glue, or may be held in place by friction, or may be held in place by another suitable means. The aerosol-forming liquid substrate storage component 288 in this example is a capillary material having a fibrous or spongy structure, although in other embodiments a reservoir or tank of aerosol-forming liquid substrate could be used. The capillary material is formed as polyester, although any suitable material could be used.The capillary material is saturated with aerosol-forming substrate. Therefore, in Figure 1, the aerosol-forming substrate is stored in the pores of the porous ceramic body 302 and in the storage component of the liquid aerosol-forming substrate 288. During use, a user takes a breath at the air outlet 204 of the cartridge 200. At the same time, the user presses a button (not shown) on the aerosol generator device 150. Pressing this button sends a signal to the controller 154, which in turn powers the battery 152 to the mesh heater 302 via electrical contacts 156 and 158 on the device and electrical contacts 214 and 216 on the cartridge. This causes a current to flow through the stainless steel wires of the mesh heater 304, thereby heating the wires and the entire mesh heater 304. In other examples, an airflow sensor, or pressure sensor, is located on the cartridge 200 and is electrically connected to the controller 154.The airflow sensor, or pressure sensor, detects when a user takes a breath at the air outlet 204 of the cartridge 200 and sends a signal to the controller 154 to power the mesh heater 304. In these examples, therefore, there is no need for the user to press a button to heat the mesh heater 304. The aerosol-forming liquid substrate contained in the pores of the porous ceramic body 302 is drawn into the openings of the mesh heater 304 by capillary action. The mesh heater 304 heats this aerosol-forming liquid substrate to vaporize it. As the aerosol-forming liquid substrate is drawn from the porous ceramic body 302 into the openings of the mesh heater 304 and vaporized, the aerosol-forming liquid substrate is also drawn from the aerosol-forming liquid substrate storage component 288 into the porous ceramic body 302. Therefore, a user may be able to generate more aerosol than if the aerosol-forming liquid substrate storage component 288 were not present. As the user takes a breath at the air outlet 204 of the cartridge 200, air is drawn into the air inlet 202. This air then travels around the heating unit 300 and into the air outlet 204. This airflow carries away the vapor formed by the heating of the liquid aerosol-forming substrate by the mesh heater 304. This trapped vapor is then cooled and condensed to form an aerosol. This aerosol is then delivered to the user through the air outlet 204. Figure 2 shows a cross-sectional view of cartridge 200 incorporating the first example of a heating unit 300. In Figure 2, cartridge 200 is no longer coupled with aerosol generating device 150. Figures 3 and 4 show a perspective view and a cross-sectional view of the first heating unit 300, respectively. Figure 3 also shows the aerosol-forming liquid substrate storage component 288. The heating unit 300 comprises the porous ceramic body 302 and the mesh heater 304. The mesh heater 304 is in contact with the porous ceramic body 302 over substantially the entirety of one face of the mesh heater 304. The 306 stainless steel wires and 308 glass fibers of the 304 mesh heater are interwoven. Therefore, the 304 mesh heater comprises a woven hybrid mesh. The 306 stainless steel wires and 308 glass fibers of the 304 mesh heater have diameters of approximately 17 microns. The thickness of the 304 mesh heater is approximately 51 microns. In Figure 3, the 309 mesh heater openings are visible. Each of these 309 openings has a dimension of approximately 70 microns. In this example, the 309 openings have a substantially square cross-section, and the dimension is equal to the length of one side of the square cross-section. The porous ceramic body 302 is formed entirely from alumina. The porous ceramic body 302 comprises pores with pore sizes ranging from 2.5 microns to 40 microns. The average pore size is approximately 10 microns. The porosity of the porous ceramic body 302 is approximately 40%. The porous ceramic body 302 comprises the first portion 320 and a projection 322. The first portion 320 has a substantially circular cross-section. This circular cross-section has a diameter of about 15 mm. The first portion 320 has a thickness of about 2 mm. Projection 322 has a substantially annular, or ring-like, cross-section. Projection 322 is located on a periphery of the first portion 320 and extends around substantially the entire periphery of the first portion 320. Projection 322 extends approximately 10 mm substantially perpendicularly from a surface of the first portion 320. Projection 322 has a width of approximately 2 mm. The width of the substantially annular projection is the difference between the outer and inner radii of the ring. The first portion 320 of the porous ceramic body 302 comprises a channel 314 extending through it. The channel 314 extends substantially in one thickness direction of the first portion 320. As such, the channel 314 extends substantially perpendicular to the plane of the mesh heater 304. The channel 314 has a diameter of approximately 500 microns. Figures 5 and 6 show a perspective view and a cross-sectional view of a second heating unit 500, respectively. Figure 5 also shows the aerosol-forming liquid substrate storage component 288. The second heating unit 500 comprises a porous ceramic body 502, and a mesh heater 504. The porous ceramic body 502 is identical to the porous ceramic body 302 of the first heating unit 300. The 504 mesh heater comprises a hybrid mesh consisting of 506 stainless steel wires and 508 rayon fibers. The 506 stainless steel wires are interwoven with, and substantially perpendicular to, the 508 rayon fibers. The 504 mesh heater is coupled to the 502 porous ceramic body. Specifically, the 504 mesh heater is bonded to the 502 porous ceramic body. To couple the 504 mesh heater to the 502 porous ceramic body, two 510, 512 metal segments are applied to the 502 porous ceramic body. In this example, the 510, 512 metal segments are formed from tin, although silver or other suitable materials could be used. The mesh heater 504 is then positioned so that the metal segments 510, 512 are between the porous ceramic body 502 and the mesh heater 504. The mesh heater 504 is then forced into the porous ceramic body 502 and into the metal segments 510, 512.The metal segments 510 and 512 bond the porous ceramic body 502 to the mesh heater 504. In some examples, the metal segments are coated onto the mesh heater. In some examples, heat is applied simultaneously, forcing the mesh heater into the porous ceramic body. The second heating unit 500 also comprises two electrodes 511, 513. These electrodes are formed from tin and are in contact with several stainless steel wires 506 and rayon fibers 508 of the mesh heater 504. When the second heating unit 500 replaces the first heating unit 300 in the cartridge 200 shown in Figures 1 and 2, the electrodes 511, 513 are each electrically connected to an electrical contact 214, 216 in the cartridge 200. This electrical connection is a wired connection and is not shown in Figures 1 or 2. The stainless steel wires 506 are electrically connected to the electrical contacts 214, 216 through this electrical connection. κζηρηη / ζζηζ / Ε / γίΛΐ The 506 stainless steel wires and 508 rayon fibers of the 504 mesh heater have diameters of approximately 17 microns. The thickness of the 504 mesh heater is approximately 51 microns. In Figure 5, the 509 openings of the mesh heater are visible. Each of these openings has a dimension of approximately 70 microns. In this example, the 509 openings have a substantially square cross-section, and the dimension is equal to the length of one side of the square cross-section. The mesh heater 504 is in contact with the porous ceramic body 502 over substantially the entire face of the mesh heater 504. During use, the aerosol-forming liquid substrate contained in the pores of the porous ceramic body 502 is drawn into the openings 509 of the mesh heater 504. During use, the second heating unit 500 operates in the same way as the first heating unit 300. The second heating unit 500 can replace the first heating unit 300 shown in the aerosol generator system of Figure 1. In this case, during use, system 100 operates identically, but power is supplied to the mesh heater 504 of the second heating unit 500 through the tin electrodes 511, 513 (instead of through the solder points 310, 312 of the first heating unit 300). Figures 7 and 8 show a perspective view and a cross-sectional view of a third heating unit 700. Figure 7 also shows an aerosol-forming liquid substrate storage component 1008. The third heating unit 700 comprises a porous ceramic body 702, and a mesh heater 704. The porous ceramic body 702 is identical to the porous ceramic body of the first heating unit 302. The 704 mesh heater comprises a perforated 706 stainless steel plate. The 706 stainless steel of the 704 mesh heater plate is an effective susceptor material. Therefore, the 706 plate acts as a susceptor. To attach plate 706 to the porous ceramic body 702, plate 706 is placed in contact with the porous ceramic body 702. A coating layer 708 of ceramic paste is then applied to plate 706. Part of the paste is on plate 706 and part is on the porous ceramic body 702. The paste applied to the porous ceramic body 702 may extend beyond a periphery of plate 706, or through openings 709 in plate 706, or, as in this example, both. At least a portion of plate 706 is located between the coating layer 708 and the porous ceramic body 702. The coating layer 708 is then sintered. The porous ceramic body 702 is sintered simultaneously. In this example, the coating layer 708 is formed from alumina identical to the alumina of the porous ceramic body 702. The coating layer 708 bonds the porous ceramic body 702 to the plate 706. The perforations in plate 706 form openings 709 with substantially circular cross-sections. In Figure 7, the openings 709 of the mesh heater 704 are visible. Each of these openings has a dimension of approximately 75 microns. In this example, the openings 709 have a substantially circular cross-section, and the dimension is equal to the diameter of the circular cross-section. The mesh heater 704 is in contact with the porous ceramic body 702 over substantially the entirety of one face of the mesh heater 704. Figure 9 shows a cross-sectional view of an aerosol generating system 900. The aerosol generating system 900 comprises an aerosol generating device 950 and a cartridge 1000 with a third heating unit 700. In this example, the aerosol generating system 900 is an electrically operated smoking system. The aerosol generating device 950 is portable and comparable in size to a conventional tobacco or cigarette. The device 950 comprises a battery 952, such as a lithium iron phosphate battery, and a controller 954 electrically connected to the battery 952. The device 950 also comprises an induction coil 956 electrically connected to the battery 952. The device 950 further comprises an air inlet 958 and an air outlet 960 in fluid communication with the air inlet 958. The cartridge 1000 comprises an air inlet 1002, an air outlet 1004, and a third heating unit 700. The air inlet 1002 is in fluid communication with the air outlet 1004. The heating unit 700 is located downstream of the air inlet 1002 and upstream of the air outlet 1004. When the cartridge 1000 is coupled with the aerosol generating device 950, as shown in Figure 9, the air outlet 960 of the device 950 is adjacent to the air inlet 1002 of the cartridge 1000. Therefore, during use, when a user takes a puff at the air outlet 1004 of the cartridge 1000, the air flows through the air inlet 958 of the device 950, then through the air outlet 960 of the device 950, and then through the air inlet 1004 of the device 950. 1002 of cartridge 1000, then through heating unit 700, then through air outlet 1004 of cartridge 1000. In Figure 9, the 1000 cartridge is coupled to the 950 aerosol generating device by coupling a screw thread 1006 of the 1000 cartridge with a corresponding screw thread 962 of the 950 aerosol generating device. The cartridge 1000 further comprises an aerosol-forming liquid substrate storage component 1008 that is in fluid communication with the porous ceramic body 702. The aerosol-forming liquid substrate storage component 1008 is in contact with the first portion 720 of the porous ceramic body 702. The aerosol-forming liquid substrate storage component 1008 may be adhered to the porous ceramic body 702 with glue, or may be held in place by friction, or may be held in place by another suitable means. The aerosol-forming liquid substrate storage component 1008 in this example is a capillary material having a fibrous or spongy structure. The capillary material is formed as polyester, although any suitable material could be used. The capillary material is soaked with aerosol-forming substrate.Therefore, in Figure 9, the aerosol-forming substrate is stored in the pores of the porous ceramic body 702 and in the aerosol-forming liquid substrate storage component 1008. During use, a user takes a breath at the air outlet 1004 of the cartridge 1000. At the same time, the user presses a button (not shown) on the aerosol generator device 950. Pressing this button sends a signal to the controller 954, which causes the battery 952 to supply a high-frequency electrical current to the induction coil 956. This causes the induction coil to create a fluctuating electromagnetic field. The mesh heater 704 is placed within this field. This fluctuating electromagnetic field generates eddy currents and hysteresis losses in the stainless steel plate 706, which acts as a susceptor heating element in the cartridge 1000. Thus, the plate 706 is heated by induction. In other examples, an airflow sensor, or pressure sensor, is located on the device 950 and is electrically connected to the controller 954.The airflow sensor, or pressure sensor, detects when a user takes a breath at the air outlet 1004 of the cartridge 1000 and sends a signal to the controller 954 to power the mesh heater 704. In these examples, therefore, there is no need for the user to press a button to heat the mesh heater 704. The aerosol-forming liquid substrate contained in the pores of the porous ceramic body 702 is drawn into the openings of the mesh heater 704 plate 706 by capillary action. The mesh heater 704 heats this aerosol-forming liquid substrate to vaporize it. As the user takes a breath at the air outlet 1004 of the cartridge 1000, the air is drawn into the air inlet 958 of the device 950, then through the air outlet 960 of the device 950, then through the air inlet 1002 of the cartridge 1000. This air then travels around the heating unit 700 and into the air outlet 1004. κζηρηη / ζζηζ / Ε / γίΛΐ This airflow draws in the vapor formed by heating the liquid aerosol substrate with mesh heater 704. This trapped vapor is then cooled and condensed to form an aerosol. This aerosol is then delivered to the user through air outlet 1004. As the aerosol-forming liquid substrate is drawn from the porous ceramic body 702 into the openings 709 of the mesh heater 704 and vaporized, the aerosol-forming liquid substrate is also drawn from the aerosol-forming liquid substrate storage component 1008 into the porous ceramic body 702. Therefore, a user may be able to generate more aerosol than if the aerosol-forming liquid substrate storage component 1008 were not present. For the purposes of this description and the appended claims, unless otherwise stated, all numbers expressing quantities, percentages, etc., shall be understood to be modified in all cases by the term "around." Furthermore, all intervals include the maximum and minimum points described and include any intermediate intervals therewith, which may or may not be specifically enumerated in this description. In this context, therefore, a number A is understood to be A ± 10% of A.

Claims

1. A cartridge for use in an aerosol generating system, comprising: a porous ceramic body having a porosity of between 30% and 65%; and a mesh heater coupled with the porous ceramic body, the mesh heater including a plurality of openings, each opening having a dimension between 50 microns and 200 microns, wherein the mesh heater is a hybrid mesh heater comprising a network of wires and fibers, the fibers having a material composition different from the wires.

2. A cartridge according to claim 1, wherein, during use, the aerosol-forming liquid substrate is drawn into the mesh heater openings from the porous ceramic body by capillary action.

3. A cartridge according to any of the preceding claims, wherein the fibers comprise one or both of glass fibers and rayon fibers.

4. A cartridge according to any preceding claim, wherein the mesh heater is coupled to the porous ceramic body over substantially an entire face of the mesh heater.

5. A cartridge according to claim 4, wherein the mesh heater is in contact with the porous ceramic body over substantially the entirety of one face of the mesh heater.

6. A cartridge according to any of the preceding claims, wherein the porous ceramic body comprises pores with an average pore size between 2.5 microns and 40 microns.

7. A cartridge according to any of the preceding claims, wherein the porous ceramic body comprises a first portion and a projection.

8. A cartridge according to claim 7, wherein the projection is located on a periphery of the first portion and extends around substantially the entire periphery of the first portion.

9. A cartridge according to any preceding claim, wherein the porous ceramic body comprises a channel extending through it, the channel having a diameter of between 300 microns and 800 microns.

10. A cartridge according to any of the preceding claims, comprising a metal segment located between the porous ceramic body and the mesh heater. κζηρηη / ζζηζ / E / γίΛΐ 11. A cartridge according to any of the preceding claims, wherein the mesh heater is located between the porous ceramic body and a coating layer of a second ceramic.

12. A cartridge according to claim 11, wherein the mesh heater is joined 5 to the porous ceramic body by the coating layer of the second ceramic.

13. An aerosol generating system comprising an aerosol generating device and a cartridge in accordance with any of the preceding claims.

14. An aerosol generating system according to claim 13, wherein the aerosol generating device comprises a power supply configured to supply power to the mesh heater to resistively heat the mesh heater.

15. An aerosol generating system according to claim 13, wherein the aerosol generating device comprises a power supply, and the cartridge or aerosol generating device comprises an inductor, and the power supply and the inductor are configured to inductively heat the mesh heater.

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