Ceramic heating element

Abstract

This disclosure relates to a ceramic heating member (100) for an aerosol generation system, the ceramic heating member (100) comprising a heating portion (110) for vaporizing a liquid aerosol forming substrate and a porous portion (130) for transporting the liquid aerosol forming substrate to the heating portion (110), wherein the heating portion (130) and the porous portion (110) are integrally formed.

Description

Technical Field

[0001] The present disclosure relates to a heating member for an aerosol generating system. In particular, and without limitation, the present disclosure relates to a heating member for a hand-held electrically operated aerosol generating system for heating an aerosol forming substrate to generate an aerosol and delivering the aerosol into a user's mouth. The present disclosure further relates to a cartridge and an aerosol generating system comprising the heating member, and also to a method of manufacturing the heating member.

Background Art

[0002] Aerosol generating systems for heating a liquid aerosol forming substrate to generate an aerosol to be delivered to a user are generally known in the prior art. These systems typically comprise an aerosol generating device and a replaceable cartridge. The cartridge contains a liquid aerosol forming substrate that can release a volatile compound when heated. The cartridge typically also includes a heater for heating the liquid aerosol forming substrate. In known aerosol generating systems, the heater comprises a resistive heating element wound around a wick that supplies the liquid aerosol forming substrate to the heating element. The aerosol generating device or the cartridge also comprises a mouthpiece. When the user inhales through the mouthpiece, an electric current flows through the heating element, heating the heating element by resistive heating or Joule heating, and as a result, heating the liquid aerosol forming substrate supplied by the wick. Thereby, a volatile compound is released from the liquid aerosol forming substrate and cooled to form an aerosol. The aerosol is then inhaled into the user's mouth through the mouthpiece.

[0003] In some other known aerosol generating systems, the aerosol generating system comprises a heater assembly having a resistance heating element located on the heated surface of a porous body. The liquid aerosol-forming substrate is supplied to the heating element from the liquid storage section through the pores of the porous body by capillary action. Such known aerosol generating systems have many drawbacks. For example, it is difficult to manufacture them while maintaining consistent manufacturing tolerances, which can lead to inconsistent vapor generation and flavor development. Inconsistent manufacturing tolerances can also affect heat conduction from the heating element to the wick, reducing the energy efficiency of such devices. A further problem encountered by such known aerosol generating systems is "dry heating" or "dry puffing," which occurs when the heating element is heated with insufficient liquid aerosol-forming substrate supplied to it. This can occur, for example, when the user consumes all the liquid aerosol-forming substrate in a cartridge and the cartridge is depleted and needs to be replaced. During operation, it is preferable to maintain a supply of the liquid aerosol-forming substrate to the heating element so that the heating element remains moist, as this helps ensure that a satisfactory aerosol is generated when negative pressure is applied to the mouthpiece. Air heating can lead to overheating of the heating element and potentially to thermal decomposition of the liquid aerosol-forming substrate, which may result in the generation of undesirable byproducts and, furthermore, unsatisfactory aerosols. Allowing the aerosol generation system to continue operating when the liquid aerosol-forming substrate is not supplied to the heating element may degrade the quality of the user experience.

[0004] Numerous prior art documents disclose aerosol generating systems having a porous transport element and a separate heating element, both of which are assembled within the aerosol generating system such that the heating element, powered through electrical contacts, heats the porous transport element. Such known systems are difficult to manufacture and assemble while maintaining consistent manufacturing tolerances, and therefore may result in inconsistent vapor generation and flavor development. Inconsistent manufacturing tolerances can also affect heat conduction from the heating element to the porous transport element, reducing the energy efficiency of such systems. The liquid is supplied from the liquid storage section to the heating element through pores in the transport element. These known aerosol generating systems may also experience "dry heating" or "dry puffing," and therefore have associated drawbacks, namely undesirable by-products, unsatisfactory aerosols, and a poor user experience.

[0005] It is desirable to provide a heating element that is easier to manufacture with high reliability and therefore results in a more energy-efficient heater assembly that can generate a more consistent aerosol. It is also desirable to provide a heating element that reduces the likelihood of the user experiencing dry heating or dry puffing. [Overview of the project]

[0006] This disclosure relates to a ceramic heating member for an aerosol generation system. The ceramic heating member may include a heating portion for vaporizing a liquid aerosol-forming substrate. The ceramic heating member may also include a porous portion for transporting the liquid aerosol-forming substrate to the heating portion. The heating portion and the porous portion may be integrally formed.

[0007] The present invention provides a ceramic heating member for an aerosol generation system. The ceramic heating member comprises a heating portion for vaporizing a liquid aerosol-forming substrate. The ceramic heating member comprises a porous portion for transporting the liquid aerosol-forming substrate to the heating portion. The heating portion and the porous portion are integrally formed.

[0008] As used herein, the term "aerosol generator" refers to a device that interacts with a liquid aerosol-forming substrate in order to generate an aerosol.

[0009] As used herein, the term "aerosol generating cartridge" refers to a component that interacts with a liquid aerosol generating apparatus in order to generate an aerosol. The aerosol generating cartridge contains, or is configured to contain, a liquid aerosol generating substrate.

[0010] As used herein, the term "liquid aerosol-generating substrate" refers to a substrate having the ability to release volatile compounds that can form aerosols. Such volatile compounds may be released by heating the aerosol-generating substrate.

[0011] As used herein, the term "heating element" refers to a component that transfers thermal energy to a liquid aerosol generating substrate. It is understood that an electrically heated element may be placed directly on a porous material.

[0012] As used herein, the term “electrical parameter” refers to an electrical characteristic, including but not limited to voltage or potential difference, current or electrical resistance. Electrical parameters may be monitored by directly measuring a parameter such as voltage, or they may be determined indirectly from another one or more electrical parameters. For example, electrical resistance may be determined using Ohm's law by first determining the voltage across the components and the current flowing through the components, and then dividing the voltage by the current.

[0013] As used herein, the term “porous material” refers to a component having multiple pores, at least some of which are interconnected. A porous material is configured to contain a liquid within its multiple pores.

[0014] As used herein, the term “thermal insulation” refers to a property that reduces or limits heat transfer. A more thermally insulating component transfers less heat by conduction, convection, or radiation than a more thermally insulating component.

[0015] The ceramic heating member of the present invention provides an improved component for an aerosol generation system. By providing a ceramic heating member in which a heating portion for vaporizing a liquid aerosol-forming substrate and a porous portion for transporting the liquid aerosol-forming substrate are integrally formed, a more robust and reliable connection can be established between the heating portion and the porous portion. This can advantageously help to improve heat transfer between the heating portion and the porous portion.

[0016] Integrating the heating portion with the porous portion also has the advantage of providing a heating element that is easy to manufacture reliably, and therefore can result in a more energy-efficient heating element that can generate a more consistent aerosol. This can provide users of the aerosol generating system with an improved and more enjoyable experience. Such arrangements can also help reduce the likelihood of users experiencing dry heating or dry puffing.

[0017] The advantage of integrally forming the heating portion with the porous portion is that it helps mitigate manufacturing tolerance issues faced in wick heaters, coil heaters, and other configurations where the heating element is detached from the liquid transport element. The dimensions and placement of the electric heating portion relative to the porous portion are also fixed, which helps in more consistent aerosol production. This is because the electric heating portion is fixed relative to the porous portion, which helps in supplying the heating element with the liquid aerosol-forming substrate. This also helps prevent undesirable heat loss, which contributes to improved energy efficiency.

[0018] By integrally forming the heating portion with the porous portion, the resulting aerosol generation system can benefit from reduced material requirements. This is because the need for intermediate components to fix the heating portion to the porous portion can be reduced or completely eliminated. Material savings can lead to cost reductions for the entire aerosol generation system. A further benefit of reduced material requirements in the overall aerosol generation system is the provision of a more sustainable and environmentally friendly solution.

[0019] These ceramic heating elements may also have an advantage in that the risk of the heating portion and the porous portion being separated is significantly reduced.

[0020] The heated portion may be permeable to fluids.

[0021] As used herein, the term “fluid permeability” in the context of a heated portion means that a liquid aerosol-forming substrate can pass from one side of the heated portion to the other side of the heated portion without having to travel around the heated portion.

[0022] Naturally, if the heating portion is fluid-permeable, the material from which the heating portion is made may also be fluid-permeable. Alternatively, the material from which the heating portion is made may be fluid-impermeable, but nevertheless, the structure or arrangement of the heating portion may allow the liquid aerosol-forming substrate to pass from one side of the heating portion to the other side.

[0023] The heating portion may be an electrically heated portion. For example, the heating portion may be a resistance heated portion. The heating portion may have any suitable shape or form. Examples of suitable shapes and forms include, but are not limited to, strips, flakes, filaments, wires, meshes, flat spiral coils, fibers, or cloths.

[0024] In some preferred embodiments, the heating portion is planar. The planar heating portion may extend substantially within the plane.

[0025] The porous portion may include a porous material having open voids. Multiple open voids may be interconnected to provide a fluid path for the aerosol-generating liquid passing through the porous portion. The porous portion may include a material that does not chemically interact with the liquid aerosol-forming substrate. The porous material may have a porosity of 20 percent to 80 percent. The porous portion may have a flat surface or a curved surface. The porous portion may have a geometric shape. The porous portion may be cubic or rectangular, or disc or cylindrical, or a combination of these shapes. The porous portion may include or consist of a material having low thermal conductivity. The porous portion may include or consist of a non-conductive material. The porous portion may include a polymer material or a ceramic material. The porous portion may include cotton. The porous portion may include, but is not limited to, porous ceramics such as Al2O3, ZrO2, Si3N4, SiC, Ti3AlC2, BN, AlN, SiO2, MgO, mica, diatomaceous earth, silicates, silicides, borides, glass, or any combination thereof. The porous portion may also include aluminum nitride or silicon carbide. Aluminum nitride and silicon carbide typically have relatively high thermal conductivity of about 100–200 watts / meter Kelvin. In sintered form, aluminum nitride and silicon carbide can have thermal conductivity of less than 100 watts / meter Kelvin.

[0026] In some preferred embodiments, the heating portion includes a mesh. The heating portion may include an array of filaments forming a mesh. As used herein, the term “mesh” encompasses grids and arrays of filaments with spaces between them. The term mesh also includes woven and nonwoven fabrics.

[0027] The filaments may be formed by etching a sheet material such as foil. This can be particularly advantageous when the heating portion includes an array of parallel filaments.

[0028] When the heating portion includes a filament mesh or fabric, the filaments may be formed individually and may be woven together.

[0029] According to one embodiment of the present disclosure, a cartridge is provided. The cartridge may include a ceramic heating member. The ceramic heating member may include a heating portion for vaporizing a liquid aerosol-forming substrate. The ceramic heating member may include a porous portion for transporting the liquid aerosol-forming substrate to the heating portion. The heating portion and the porous portion may be integrally formed.

[0030] According to one embodiment of the present disclosure, a cartridge comprising a ceramic heating member for an aerosol generating system is provided. The ceramic heating member includes a heating portion for vaporizing a liquid aerosol-forming substrate. The ceramic heating member includes a porous portion for transporting the liquid aerosol-forming substrate to the heating portion. The heating portion and the porous portion are integrally formed.

[0031] The cartridge may include a liquid aerosol-forming substrate within a liquid storage portion. The liquid aerosol-forming substrate may be as described above.

[0032] The porous portion may be fluidly connected to the liquid storage portion. The porous portion may have a liquid absorption surface. The liquid absorption surface of the porous portion may be fluidly connected to the liquid storage portion.

[0033] The liquid storage portion may be disposed on the liquid absorption surface of the porous portion.

[0034] An aerosol generating system is provided. The aerosol generating system may comprise a cartridge and an aerosol generating device. The cartridge may comprise a heating element. The cartridge may comprise a liquid storage portion for holding an aerosol-forming substrate. The heating element may comprise a heating portion for vaporizing the liquid aerosol-forming substrate. The heating element may comprise a porous portion for transporting the liquid aerosol-forming substrate to the heating portion. The porous portion may have a liquid-absorbing surface and a heating edge. The heating portion may be located at the heating edge of the porous portion.

[0035] The aerosol generator may include a power supply for providing power to the heating section. The aerosol generator may also include a control circuit configured to control the supply of power from the power supply to the heating section.

[0036] An aerosol generation system is provided, comprising a cartridge and an aerosol generator. The cartridge comprises a heating element and a liquid storage section for holding a liquid aerosol-forming substrate. The heating element comprises a heating section for vaporizing the liquid aerosol-forming substrate and a porous section for transporting the liquid aerosol-forming substrate to the heating element. The porous section has a liquid absorption surface and a heating edge. The heating element is located at the heating edge of the porous section.

[0037] The aerosol generator may further include a power supply for supplying power to the heating section, and a control circuit configured to control the power supply from the power supply to the heating section.

[0038] The cartridge may contain a liquid aerosol-forming substrate within the liquid storage portion. The liquid aerosol-forming substrate may be as described above.

[0039] The aerosol generating system may be portable. The aerosol generating system may be comparable in size to a conventional cigar or cigarette.

[0040] The cartridge may be detachably attached to the aerosol generator.

[0041] The aerosol-forming substrate may be liquid at room temperature. The aerosol-forming substrate may contain both liquid and solid components. The liquid aerosol-forming substrate may contain nicotine. The nicotine-containing liquid aerosol-forming substrate may be a nicotine salt matrix. The liquid aerosol-forming substrate may contain plant-derived materials. The liquid aerosol-forming substrate may contain tobacco. The liquid aerosol-forming substrate may contain tobacco-containing materials that contain volatile tobacco-flavored compounds released from the aerosol-forming substrate upon heating. The liquid aerosol-forming substrate may contain homogenized tobacco materials. The liquid aerosol-forming substrate may contain non-tobacco-containing materials. The liquid aerosol-forming substrate may contain homogenized plant-derived materials.

[0042] The liquid aerosol-forming substrate may contain one or more aerosol-forming compounds. The aerosol-forming compounds are any suitable known compounds or mixtures of compounds that facilitate the formation of a high-density, stable aerosol during use and are substantially resistant to thermal decomposition at the system's operating temperature. Examples of suitable aerosol-forming compounds include glycerin and propylene glycol. Suitable aerosol-forming compounds are well known in the art and include, but are not limited to, polyhydric alcohols (e.g., triethylene glycol, 1,3-butanediol, glycerin), esters of polyhydric alcohols (e.g., glycerol monoacetate, diacetate, or triacetate), and aliphatic esters of monocarboxylic acids, dicarboxylic acids, or polycarboxylic acids (e.g., dimethyl dodecanediol, dimethyl tetradecanediol). The liquid aerosol-forming substrate may also contain water, a solvent, ethanol, plant extracts, and natural or artificial flavors.

[0043] The liquid aerosol-forming substrate may contain nicotine and at least one aerosol-forming agent. The aerosol-forming agent may be glycerin or propylene glycol. The aerosol-forming agent may contain both glycerin and propylene glycol. The liquid aerosol-forming substrate may have a nicotine concentration of about 0.5% to about 10%, for example, about 2%.

[0044] The airflow path may pass through the liquid storage portion. For example, the liquid storage portion may have an annular cross-section defining an internal passage or aerosol channel, and the airflow path may extend through the internal passage or aerosol channel of the liquid storage portion.

[0045] The cartridge may include a cartridge housing. The cartridge housing may be formed from a durable material. The cartridge housing may be formed from a liquid-impermeable material. The cartridge housing may be formed from a moldable plastic material such as polypropylene (PP) or polyethylene terephthalate (PET), or from a copolymer such as Tritan® made from three monomers, namely dimethyl terephthalate (DMT), cyclohexanedimethanol (CHDM), and 2,2,4,4-tetramethyl-1,3-cyclobutanediol (CBDO). The cartridge housing may define a portion of the liquid storage area, i.e., a storage section. The cartridge housing may define a liquid storage section. The cartridge housing and the liquid storage section may be formed integrally. Alternatively, the liquid storage section may be formed separately from the outer housing or disposed within the outer housing.

[0046] The aerosol generator may include a power supply for supplying power to the heating element. The aerosol generator may also include a control circuit configured to control the supply of power from the power supply to the heating element. The cartridge may be detachably coupled to the aerosol generator.

[0047] The aerosol generator may include a housing. The housing may be elongated. The housing may contain any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics, or composite materials containing one or more of these materials, or thermoplastic resins suitable for food or pharmaceutical applications, such as polypropylene, polyetheretherketone (PEEK), and polyethylene. The material is preferably lightweight and not brittle.

[0048] The aerosol generator housing may define a cavity for receiving a portion of the cartridge. The aerosol generator may have a connecting terminal configured to connect the aerosol generator to the cartridge. The connecting terminal may include a cavity for receiving the cartridge.

[0049] The power source may be any suitable power source. Preferably, the power source is a DC power source. The power source may be a battery. The battery may be a lithium-based battery, for example, a lithium cobalt battery, a lithium iron phosphate battery, a lithium titanate battery, or a lithium polymer battery. The battery may be a nickel-metal hydride battery or a nickel-cadmium battery. The power source may be another form of charge storage device, such as a capacitor. The power source may be rechargeable and may be configured for numerous charge and discharge cycles. The power source may have a capacity that allows for sufficient energy storage for one or more user experiences of the aerosol generating system. For example, the power source may have a capacity that allows for continuous aerosol generation for about six minutes, or a multiple of six minutes, corresponding to the typical time it takes to smoke one conventional cigarette. In another embodiment, the power source may have a capacity that allows for a predetermined number of smoking sessions or for intermittent startup of the aerosol generating system.

[0050] The control circuit may include any suitable controller or electrical component. The controller may include memory. Information for performing the operation of the device or system may be stored in memory. The control circuit may include a microprocessor. The microprocessor may be a programmable microprocessor, a microcontroller, an application-specific integrated circuit (ASIC), or other electronic circuit capable of providing control. The control circuit may be configured to supply power to the heating element continuously after the device is started, or to supply power intermittently, such as with each smoke extraction. Power may be supplied to the heating element in the form of current pulses, for example by pulse width modulation (PWM).

[0051] Features described in relation to one of the above embodiments may be equally applicable to other embodiments of the present disclosure.

[0052] The porous portion may include a liquid-absorbing surface and a heating edge. The heating portion may be adjacent to the heating edge of the porous portion. The heating edge of the porous portion may include an interface with the heating portion. The interface between the porous portion and the heating portion does not have to be a clearly defined interface so that the material properties of the interface can transition from the material properties of the heating portion to the material properties of the porous portion. In other words, the edge of the interface adjacent to the heating portion may have substantially the same material properties as the heating portion, and the edge of the interface adjacent to the porous portion may have substantially the same material properties as the porous portion.

[0053] The porous portion may have any thickness. The thickness of the porous portion may refer to the extension of the porous portion in the direction between the liquid absorption surface and the heating edge. This may correspond to the direction of the liquid flow path through the porous portion. The thickness of the porous portion may depend on the material from which it is fabricated and the thermal properties of the liquid it contains. The porous portion may have a thickness of at least 1 millimeter. For example, the porous portion may have a thickness of at least 2 millimeters, at least 3 millimeters, at least 4 millimeters, or at least 5 millimeters.

[0054] The porous portion may have a thickness of 10 millimeters or less. For example, the porous portion may have a thickness of 9 millimeters or less, 8 millimeters or less, 7 millimeters or less, or 6 millimeters or less.

[0055] The porous portion may have a thickness of 1 to 10 millimeters. For example, the porous portion may have a thickness of 2 to 9 millimeters, 3 to 8 millimeters, 4 to 7 millimeters, or 5 to 6 millimeters. The porous portion may have a thickness of approximately 5 millimeters.

[0056] The heating portion may have any thickness. The thickness of the heating portion may refer to the extension of the heating portion in the direction between the liquid absorption end of the heating portion adjacent to the heating end of the porous portion and the heating surface of the heating portion. This may correspond to the direction of the liquid flow path through the porous portion. The heating portion may have a thickness of at least 1 micrometer. The heating portion may have a thickness of at least 2 micrometers. The heating portion may have a thickness of at least 5 micrometers. The heating portion may have a thickness of at least 200 micrometers. The heating portion may have a thickness of at least 220 micrometers.

[0057] The heating portion may have a thickness of less than 300 micrometers. The heating portion may have a thickness of less than 250 micrometers. The heating portion may have a thickness of less than 50 micrometers. The heating portion may have a thickness of less than 20 micrometers.

[0058] The heating portion may have a thickness of 1 mm to 10 mm. The heating portion may have a thickness of 1 mm to 5 mm. The heating portion may have a thickness of 2 mm to 5 mm.

[0059] The heating portion may have a thickness of 200 to 300 micrometers. The heating portion may have a thickness of 200 to 250 micrometers. The heating portion may have a thickness of 220 to 300 micrometers.

[0060] The heating portion may be porous. The heating porosity may extend across the entire surface of the heating portion. Alternatively, the heating portion may not be porous across its entire surface. For example, the first portion of the heating portion may be porous, while the second portion may be non-porous. Embodiments in which the heating portion is a porous heating portion may be advantageous in that the aerosol-generating liquid can flow from the porous portion into the heating body. This may improve the energy efficiency of aerosol generation and may also contribute to more consistent aerosol generation.

[0061] The heating element may be a doped ceramic material. The heating element may be doped so that it is conductive. Doping the ceramic material may be advantageous in that it avoids changing the porosity of the ceramic material when it is a porous ceramic material. This may be preferable to other known techniques for forming heating elements, which involve depositing the heating element by thin-film or thick-film techniques, which can reduce the properties of the ceramic material, particularly the porosity. The thickness of the doped portion may be increased when the cross-sectional area of ​​the heating portion is small or when the required heating resistance is high. The dopant used to dope the ceramic heating element may be an n-type dopant or a p-type dopant. The dopant may be, but is not limited to, nitrogen, phosphorus, aluminum, or boron. The interface between the heating portion and the porous portion may include a portion of the partially doped ceramic material. In other words, the edge of the interface adjacent to the heating portion may be doped to substantially the same extent as the heating portion, and the edge of the interface adjacent to the porous portion may not be substantially doped.

[0062] Ceramic materials may be doped by ion implantation. Ion implantation involves implanting or exchanging ions into a layer of bulk material, removing one species and replacing it with another. Ion implantation can be carried out chemically or physically.

[0063] Ceramic materials may be doped by nuclear transmutation. Nuclear transmutation involves irradiating a material with particles such as neutrons or alpha particles to convert one atomic species already present in the material into another, resulting in a short-lived decay process that leads to a stable isotope that was not present in the original material. Nuclear transmutation has the advantage that doping occurs directly within the ceramic material and does not require the bonding or attachment of additional conductive materials. Therefore, nuclear transmutation offers a more monolithic approach.

[0064] The heating portion may include a conductive material. The heating portion may also be an electrical resistance heating portion. The heating portion may be made from any suitable conductive material. Suitable materials include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilide), carbon, graphite, metals, alloys, and composite materials made of ceramic and metallic materials. Such composite materials may include doped or undoped ceramics. An example of a suitable doped ceramic is doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Suitable alloys include stainless steel, constantan, nickel-containing, cobalt-containing, chromium-containing, aluminum-containing, titanium-containing, zirconium-containing, hafnium-containing, niobium-containing, molybdenum-containing, tantalum-containing, tungsten-containing, tin-containing, gallium-containing, manganese-containing, and iron-containing alloys, as well as nickel, iron, cobalt, stainless steel-based superalloys, Timetal®, iron-aluminum alloys, and iron-manganese-aluminum alloys. Timetal® is a registered trademark of Titanium Metals Corporation. The heating element may be made from stainless steel, such as 300 series stainless steels, including AISI 304, 316, 304L, and 316L. In a preferred example, the electric heating element may contain one or more NiCr and TiZr.

[0065] Additionally, the heating portion may include the above-mentioned combination of materials. Combinations of materials may be used to improve the control of the resistance of the heating element. For example, a material with high resistivity may be combined with a material with low resistivity. This may be advantageous if one of the materials is more beneficial in terms of other aspects, such as price, machinability, or other physical and chemical parameters. Advantageously, heating with high resistance allows for more efficient use of battery energy.

[0066] The heating portion and the porous portion may be molded as a single monolithic part. This can also help simplify the manufacturing of ceramic heating components by reducing manufacturing time and providing a more cost-effective solution. This is advantageous as it forms a tight mechanical connection between the heating portion and the porous portion.

[0067] The heating portion may be a doped portion of the ceramic heating element. The heating portion may be doped so that it is conductive. Doping the ceramic heating element may be advantageous in that it avoids changing the porosity of the ceramic material when it is a porous ceramic material. This may be preferable to other known techniques for forming heating elements, which involve depositing the heating element by thin-film or thick-film techniques, which can reduce the properties of the ceramic material, particularly the porosity. The thickness of the doped portion may be increased when the cross-sectional area of ​​the heating portion is small or when the required heating resistance is high. The dopant used to dope the ceramic heating element may be an n-type dopant or a p-type dopant. The dopant may be, but is not limited to, nitrogen, phosphorus, aluminum, or boron. The interface between the heating portion and the porous portion may include a portion of the partially doped ceramic material. In other words, the edge of the interface adjacent to the heating portion may be doped to substantially the same extent as the heating portion, and the edge of the interface adjacent to the porous portion may not be substantially doped.

[0068] The liquid-absorbing surface of the porous portion may have a different area from the area of ​​the heating edge of the porous portion. The porous portion may be substantially incompressible. The porous portion may be incompressible.

[0069] Porous portions with heating edges having the same surface area as the liquid absorption surface can be inefficient because the heat generated by the heater is not used for vaporizing the aerosol-forming substrate. Inefficient heating components reduce aerosol throughput.

[0070] Advantageously, providing a porous portion in which the heating edge and the liquid absorption surface have different areas can improve the throughput of aerosols that can be generated by the heating member compared to a porous portion in which the heating edge has the same area as the liquid absorption surface.

[0071] Improving heating efficiency can reduce power consumption during the use of heating components.

[0072] The area of ​​the heated edge of the porous portion may be smaller than the area of ​​the liquid-absorbing surface of the porous portion. The area of ​​the liquid-absorbing surface of the porous portion may be larger than the area of ​​the heated edge of the porous portion.

[0073] Advantageously, if the porous portion has a shape such that the heating edge has a smaller area than the liquid absorption surface, the heat flow from the heating portion to the liquid absorption surface and then to the liquid storage portion by conduction can be reduced. The relatively small heating edge provides a small heat transfer region from which heat can be transferred by conduction from the heating portion to the porous portion and then to the liquid absorption surface.

[0074] Reducing heat loss from the heated portion to the bulk of the porous portion can increase heating efficiency because, as a result, more thermal energy provided by the heated portion can be used to vaporize the aerosol-forming substrate. Consequently, a porous portion having a shape such that the heated edge has a smaller area than the liquid-absorbing surface can increase the throughput of aerosols generated by the heated member.

[0075] Advantageously, a porous portion having a shape such that the heating edge has a smaller area than the liquid absorption surface can reduce the area of ​​the heating edge that is not sufficiently close to the heating portion, allowing the aerosol-forming substrate delivered to the heating edge to vaporize. In other words, the size and shape of the heating edge can more closely match the size and shape of the heating portion. As a result, more liquid aerosol-forming substrate may be delivered from the liquid absorption surface to the heating edge region closer to the heating portion, which can lead to more liquid aerosol-forming substrate vaporization at the heating edge. An increase in vaporized liquid aerosol-forming substrate can increase the throughput of aerosols generated by the heating element. Furthermore, this arrangement can allow for maximization of the power density at the heating edge, which also improves heating efficiency.

[0076] Advantageously, a liquid absorption surface with a larger surface area than the heating edge may allow the liquid absorption surface to receive a greater amount of liquid aerosol substrate from the liquid storage portion. As a result of the relatively small surface area of ​​the heating edge, the flow rate of liquid aerosol-forming substrate to the heating portion may be higher than that of a typical heating element as the liquid aerosol-forming substrate is transported through the porous portion toward the heating edge. An increased flow rate of liquid aerosol-forming substrate in the heating portion may increase the throughput of aerosols generated by the heating element.

[0077] The area of ​​the heated edge of the porous material may be larger than the area of ​​the liquid-absorbing surface of the ceramic porous material. The area of ​​the liquid-absorbing surface of the porous material may be smaller than the area of ​​the heated edge of the porous portion.

[0078] Advantageously, if the porous portion has a shape such that the liquid absorption surface has a smaller area than the heating edge, the smaller area of ​​the liquid absorption surface can reduce the heat flow from the heating portion to the liquid absorption surface through the aerosol-forming substrate by heat conduction. Reducing the heat flow from the heating edge to the liquid absorption surface can increase thermal efficiency because, as a result, more thermal energy provided by the heating portion can be used to vaporize the liquid aerosol-forming substrate. Consequently, a porous portion having a shape such that the liquid absorption surface has a smaller area than the heating edge can result in improved heating efficiency, which can increase the throughput of aerosols generated by the heating member.

[0079] Advantageously, a porous portion having a shape such that the liquid absorption surface has a smaller area than the heating edge can reduce the area of ​​the heating edge that is not sufficiently close to the heating element, allowing the aerosol-forming substrate delivered to the heating edge to vaporize. In other words, the size and shape of the heating edge may more closely match the size and shape of the heating element. As a result, more liquid aerosol-forming substrate may be delivered from the liquid absorption surface and to the heating edge region closer to the heating element, which can lead to more liquid aerosol-forming substrate vaporization at the heating edge. An increase in vaporized liquid aerosol-forming substrate can increase the throughput of aerosols generated by the heating element.

[0080] The heated edge of the porous portion may be convex in one or both of the first and second transverse directions, the first transverse direction being perpendicular to the second transverse direction.

[0081] The inclusion of these porous portions can increase the surface area of ​​the heating edge without increasing its width. This can help improve the efficiency of the aerosol generation system when vaporizing the liquid aerosol-forming substrate, while avoiding the need to redesign other components of the aerosol generation system to accommodate the porous portions.

[0082] Providing a heating end that is convex along one or both of the first and second transverse directions may help avoid or minimize recirculation of the airflow adjacent to the heater assembly. In particular, a convex heating end may help avoid or minimize recirculation of the airflow adjacent to the central region of the heater assembly. This may reduce the level of turbulence in the airflow adjacent to the heater assembly. Reducing the level of turbulence in the airflow adjacent to the heater assembly may improve the entrainment of vapors of aerosol-forming substrates in the airflow. This may improve the quality of aerosols produced by the aerosol-generating system.

[0083] Improving the entrainment of vapor in the airflow through an aerosol generation system can prevent or reduce the condensation of vapor into large droplets of liquid aerosol-forming substrates. This can help avoid an unpleasant and undesirable user experience.

[0084] Improving the entrainment of vapor in the airflow passing through an aerosol generating system can help avoid or reduce condensation of vapor on the internal surfaces of the aerosol generating system. This can help avoid or minimize damage to the aerosol generating system and enable its optimal functioning.

[0085] The heating edge of the porous portion may be convex in a single transverse direction.

[0086] The heated edges of the porous portion may be convex in both the first transverse direction and the second transverse direction.

[0087] The heating edge of the porous portion may be convex in one or both of the first and second transverse directions, based on the configuration of the heater assembly relative to one or more airflow paths in the aerosol generating system. The heater assembly may be configured to minimize the level of turbulence in the airflow adjacent to the heater assembly. For example, it may be advantageous for the heater assembly to be positioned within the aerosol generating system such that the air drawn into the aerosol generating system follows a curved path along at least a portion of the curved surface of the heater assembly.

[0088] The heating element may be convex in one or both of the first and second transverse directions.

[0089] The curvature of the heating element in the first transverse direction may be substantially the same as the curvature of the heated edge of the porous portion in the first transverse direction. The curvature of the heating element in the second transverse direction may be substantially the same as the curvature of the heated edge of the porous body in the second transverse direction. The curvature of the heating element in both the first and second transverse directions may be substantially the same as the curvature of the heated edge of the porous body in both the first and second transverse directions, respectively.

[0090] The average pore size of the porous portion may vary between the liquid absorption surface and the heating edge.

[0091] The porous portion may include a first average pore size at the liquid absorption surface and a second average pore size at the heating edge. The first average pore size may be larger than the second average pore size.

[0092] The first pore size at the liquid-absorbing surface may be about 150 micrometers. The second pore size at the heating edge may be about 20 micrometers. The pore size changes linearly between the first and second pore sizes, providing a pore size gradient between the liquid-absorbing surface and the heating edge of the porous ceramic body.

[0093] The pore structure and pore size gradient of a porous ceramic body can be achieved by etching the pores into a portion of the silicon carbide.

[0094] The ceramic heating element may be configured to receive power that changes from high power to low power over the duration of fume extraction. The ceramic heating element may constitute an aerosol generating system with a control system configured to supply power to the ceramic heating element that changes from high power to low power over the duration of fume extraction. Varying the power in this way can help reduce the time required for the aerosol generating substrate to reach its boiling point and aerosolize. The initial high power helps compensate for the thermal inertia of the overall heating system, resulting in a greater amount of aerosol generated during fume extraction. The initial high power at the start of fume extraction is advantageous in ensuring that the aerosol generating system can rapidly generate aerosols after fume extraction is detected by the system user. The high power at the start of fume extraction ensures that the heating element quickly reaches its operating temperature. This also ensures that the time to vaporization of the aerosol generating substrate is shorter than the time for heat conduction in the aerosol generating system. This reduces heat loss in the system. During the fume extraction process, the supplied power is reduced to maintain the heating element at its operating temperature by providing heat only to the incoming liquid.

[0095] The ceramic heating element may be configured to receive a high power supply for a short period of time at the start of smoke extraction, followed by a lower power supply for a longer period of time.

[0096] The ceramic heating element may be configured to receive power that changes in three or more stages, from high power to low power, over the duration of smoke absorption.

[0097] The ceramic heating element may be configured to receive power that decreases as a function of time over the duration of smoke extraction.

[0098] An aerosol generating system is provided according to one embodiment of the present disclosure. The aerosol generating system may include a heating element as described above. The heating element may be fluid permeable so that vapor is released from the heating element in the mean vapor discharge direction during use. The aerosol generating system may further include an air intake and an aerosol outlet. The air intake may be in fluid communication with the aerosol outlet to define an airflow path through the aerosol generating system. The heating element may be in fluid communication with the airflow path so that air flows through the heating element in the mean airflow direction. The heating element and the airflow path may be arranged such that the angle between the mean vapor discharge direction and the mean airflow direction is less than 135 degrees.

[0099] Advantageously, by arranging the heating elements and airflow paths so that the angle between the mean vapor discharge direction and the mean airflow direction is less than 135 degrees, the mean airflow direction does not directly oppose the mean vapor discharge direction. Therefore, the momentum of the vapor and airflow does not decrease to the same extent as if the mean airflow direction were directly opposite to the mean vapor discharge direction. This reduces the tendency for recirculation and turbulence to occur within the airflow path, and the vapor is less likely to collide with the internal surfaces of the aerosol generating system. Consequently, the likelihood of aerosol condensation occurring within the aerosol generating system is low.

[0100] The average vapor emission direction may be substantially perpendicular to the heated surface of the porous ceramic body. As used herein, the term “substantially perpendicular” means 90 degrees plus or minus 10 degrees, preferably plus or minus 5 degrees.

[0101] The advantage of having the mean vapor release direction substantially perpendicular to the heated surface of a porous ceramic body is that, because the vapor is released substantially perpendicular to the heated surface of the porous ceramic body, the mean vapor release direction can be easily directed relative to the mean airflow direction. Therefore, the desired angle between the mean vapor release direction and the mean airflow direction can be achieved by appropriately angling the heating element with respect to the airflow in the airflow path, or vice versa.

[0102] The heating element and the airflow path may be arranged such that the angle between the average vapor discharge direction and the average airflow direction is less than 110 degrees, preferably less than 100 degrees.

[0103] The heating element and airflow path may be arranged such that the angle between the mean vapor discharge direction and the mean airflow direction is approximately 90 degrees. This arrangement ensures that the vapor is discharged at an angle substantially perpendicular to the mean airflow direction. The mean vapor discharge direction has no velocity or directional component opposite to the airflow direction, thus reducing momentum loss in the airflow. This reduces the tendency for recirculation and turbulence to occur within the airflow path, and the vapor is less likely to collide with the internal surfaces of the aerosol generating system. Furthermore, vapor mixing within the airflow is improved. Therefore, the likelihood of aerosol condensation occurring within the aerosol generating system is low.

[0104] The heating element and airflow path may be arranged such that the angle between the mean vapor discharge direction and the mean airflow direction is less than 90 degrees. In this arrangement, the mean vapor discharge direction does not have a velocity or directional component opposite to the airflow direction, and in fact has a velocity and directional component in the same direction as the mean airflow direction. Therefore, any loss of momentum in the airflow is further reduced. This reduces the tendency for recirculation and turbulence to occur in the airflow path, and the vapor is less likely to collide with the internal surfaces of the aerosol generating system. Furthermore, the mixing of vapor into the airflow is improved. Therefore, the likelihood of aerosol condensation occurring in the aerosol generating system is low.

[0105] The heating element and airflow path may be arranged such that the angle between the mean vapor discharge direction and the mean airflow direction is approximately 45 degrees. Alternatively, the heating element and airflow path may be arranged such that the angle between the mean vapor discharge direction and the mean airflow direction is less than 45 degrees.

[0106] The heating elements and airflow paths may be arranged such that the mean vapor discharge direction and the mean airflow direction are substantially the same. In this arrangement, since the mean vapor discharge direction and the mean airflow direction are identical, there is virtually no loss of momentum in the airflow. This reduces the tendency for recirculation and turbulence to occur within the airflow paths, and the vapor is less likely to collide with the internal surfaces of the aerosol generating system. Furthermore, vapor mixing in the airflow is improved. Therefore, the likelihood of aerosol condensation occurring within the aerosol generating system is low.

[0107] The cross-sectional area of ​​the airflow path in the heating element region may be configured such that the airflow velocity during use is 0.1 to 2 meters / second, preferably 0.5 to 1.5 meters / second, and more preferably about 1 meter / second. It has been found that airflow velocities in this range effectively entrain the steam released from different designs of the heating element without excessively cooling the heating element.

[0108] The heating element may comprise a porous layer of conductive material. Advantageously, a heating element comprising a porous layer of conductive material allows for resistance heating and also allows current to flow through the heating element, enabling vapor to move through the pores in its porous structure. Therefore, vapor release occurs through the porous heating element. This avoids the accumulation of vapor pressure beneath the heating element and high-speed vapor release at the sides of the heating element. The inventors have found that this arrangement generates consistent vapor across the heating element, resulting in a lower vapor release rate of approximately 0.1 meters / second. Such a low vapor release rate means that the vapor is easily carried by an airflow that reduces vapor collisions on the inner walls of the aerosol generating system.

[0109] This disclosure also relates to a method for manufacturing a ceramic heating element for an aerosol generating system. The method may include a step of forming a porous ceramic body for transporting a liquid aerosol-forming substrate. The method may further include a step of doping a portion of the porous ceramic body to form a heating element for vaporizing the liquid aerosol-forming substrate.

[0110] The present invention also provides a further method for manufacturing a ceramic heating element for an aerosol generating system. The method includes the step of forming a porous ceramic body for transporting a liquid aerosol-forming substrate. The method further includes the step of doping a portion of the porous ceramic body to form a heating element for vaporizing the liquid aerosol-forming substrate.

[0111] The process of doping a portion of a porous ceramic body may include applying a dopant material to the porous ceramic body. The process of doping a portion of a porous ceramic body may also include heating the dopant material and the porous ceramic body to diffuse dopant ions into the porous ceramic body.

[0112] The process of doping a portion of a porous ceramic body may include contacting the porous ceramic body with a liquid containing a dopant material. The process of doping a portion of a porous ceramic body may include heating the dopant material and the porous ceramic body. The process of doping a portion of a porous ceramic body may include applying an electric field to diffuse dopant ions into the porous ceramic body.

[0113] The process of doping a portion of a porous ceramic body may include ion implantation. Ion implantation involves implanting or exchanging ions into a layer of bulk material, removing one species and replacing it with another. Ion implantation can be carried out chemically or physically.

[0114] The process of doping a portion of a porous ceramic body may include nuclear transmutation. Nuclear transmutation involves the irradiation of particles such as neutrons or alpha particles to convert one atomic species already present in the material into another, resulting in a short-lived decay process that leads to a stable isotope that was not present in the original material. Nuclear transmutation has the advantage that doping takes place directly within the ceramic material and does not require the bonding or attachment of additional conductive materials. Therefore, nuclear transmutation offers a more monolithic approach.

[0115] The disclosure also relates to a further method for manufacturing a ceramic heating element for an aerosol generating system. The method may include the step of placing a layer of a first ceramic material in a mold. The method may further include the step of placing a layer of a second ceramic material in a mold. The method may further include the step of forming the layers of the first and second ceramic materials in a mold to form a ceramic heating element comprising a heating portion formed from the layer of the first ceramic material and a porous portion formed from the layer of the second ceramic material.

[0116] The present invention also provides a further method for manufacturing a ceramic heating member for an aerosol generating system. The method includes the step of placing a layer of a first ceramic material in a mold. The method further includes the step of placing a layer of a second ceramic material in a mold. The method further includes the step of molding the first and second ceramic material layers in a mold to form a ceramic heating member comprising a heating portion formed from the first ceramic material layer and a porous portion formed from the second ceramic material layer.

[0117] The step of placing a second layer of ceramic material into the mold may include placing the second ceramic material directly adjacent to the first ceramic material.

[0118] The first ceramic material may be a conductive material. The second ceramic material may be an electrical insulating layer.

[0119] The features and related advantages described above in relation to the heating element of this disclosure may also be applied to the method of this disclosure. [Examples]

[0120] A non-exclusive list of non-limiting embodiments is provided below. One or more features of these embodiments may be combined with any one or more features of other embodiments, forms, or aspects described herein.

[0121] Example 1. A ceramic heating element for an aerosol generation system, comprising a heating portion for vaporizing a liquid aerosol-forming substrate and a porous portion for transporting the liquid aerosol-forming substrate to the heating portion, wherein the heating portion and the porous portion are integrally formed. Example 2. The ceramic heating member according to Example 1, wherein the porous portion comprises a liquid-absorbing surface and a heating edge, and the heating portion is adjacent to the heating edge of the porous portion. Example 3. A ceramic heating element according to Example 1 or Example 2, wherein the heating portion is porous. Example 4. A ceramic heating element according to any one of Examples 1 to 3, wherein the heating portion contains a conductive material. Example 5. A ceramic heating element according to any one of Examples 1 to 4, wherein the heating portion and the porous portion are molded as a single monolithic component. Example 6. A ceramic heating element according to any one of Examples 1 to 4, wherein the heating portion is the doped portion of the ceramic heating element. Example 7. A ceramic heating element according to any one of Examples 2 to 6, wherein the liquid-absorbing surface of the porous portion has a different area from the area of ​​the heating edge of the porous portion. Example 8. A ceramic heating member according to any one of Examples 2 to 7, wherein the heating end of the porous body is convex in one or both of the first transverse direction and the second transverse direction, and the first transverse direction is perpendicular to the second transverse direction. Example 9. A ceramic heating element according to any one of Examples 2 to 8, wherein the average pore size of the porous portion varies between the liquid absorption surface and the heating edge. Example 10. The ceramic heating element according to any one of Examples 1 to 9, wherein the ceramic heating element is configured to be supplied with power that changes from high power to low power over the duration of smoke extraction. Example 11. The ceramic heating element according to Example 10, wherein the ceramic heating element is configured to be supplied with high power for a short period of time at the start of smoke extraction, and then supplied with lower power for a longer period of time thereafter. Example 12. The ceramic heating element according to Example 10, wherein the ceramic heating element is configured to be supplied with power that changes in three or more stages from high power to low power over the duration of smoke extraction. Example 13. The ceramic heating element according to Example 10, wherein the ceramic heating element is configured to be supplied with power that decreases as a function of time over the duration of smoke extraction. Example 14. An aerosol generating system comprising a ceramic heating element as described in any of Examples 1 to 13, wherein the heating element is fluid permeable so that vapor is discharged from the heater assembly in the mean vapor discharge direction during use, the aerosol generating system further comprises an air intake and an aerosol outlet, the air intake is in fluid communication with the aerosol outlet to define an airflow path through the aerosol generating system, the heater assembly is arranged in fluid communication with the airflow path so that air flows through the heater assembly in the mean airflow direction, and the heater assembly and the airflow path are arranged such that the angle between the mean vapor discharge direction and the mean airflow direction is less than 135 degrees. Example 15. A method for manufacturing a ceramic heating element for an aerosol generating system, comprising: forming a porous ceramic body for transporting a liquid aerosol-forming substrate; and doping a portion of the porous ceramic body to form a heating element for vaporizing the liquid aerosol-forming substrate. Example 16. A method for manufacturing a ceramic heating member according to Example 15, wherein the step of doping a portion of a porous ceramic body includes applying a dopant material to the porous ceramic body and heating the dopant material and the porous ceramic body to diffuse dopant ions into the porous ceramic body. Example 17. A method for manufacturing a ceramic heating member according to Example 15, wherein the step of doping a portion of a porous ceramic body includes contacting the porous ceramic body with a liquid containing a dopant material, heating the dopant material and the porous ceramic body, and applying an electric field to diffuse dopant ions into the porous ceramic body. Example 18. A method for manufacturing a ceramic heating member according to Example 15, wherein the step of doping a portion of a porous ceramic body includes ion implantation. Example 19. A method for manufacturing a ceramic heating member according to Example 15, wherein the step of doping a portion of a porous ceramic body includes nuclear transmutation. Example 20. A method for manufacturing a ceramic heating member for an aerosol generating system, comprising: placing a layer of first ceramic material in a mold; placing a layer of second ceramic material in a mold; and molding the first and second ceramic material layers in the mold to form a ceramic heating member including a heating portion formed from the first ceramic material layer and a porous portion formed from the second ceramic material layer.

[0122] Herein, the present invention will be further explained with reference to the attached drawings, although this is purely illustrative. [Brief explanation of the drawing]

[0123] [Figure 1] Figure 1 shows a schematic cross-section of a ceramic heating member according to an embodiment of the present disclosure, in which the heating portion and the porous portion are integrally formed. [Figure 2A] Figure 2A shows the power profiles for three different energy supply modes to the heating section. [Figure 2B] Figure 2B shows the power profiles for three different energy supply modes to the heating section. [Figure 2C] Figure 2C shows the power profiles for three different energy supply modes to the heating section. [Figure 3] Figure 3 is a schematic diagram of the interior of an aerosol generation system according to one embodiment of the present disclosure. [Figure 4] Figure 4 is a schematic cross-sectional view of a portion of an aerosol generating system according to another embodiment of the present disclosure, showing the arrangement of a heating element in the airflow path within the aerosol generating system. [Figure 5] Figure 5 is a schematic cross-sectional view of a portion of an aerosol generating system according to another embodiment of the present disclosure, showing an alternative arrangement of a heating element in the airflow path within the aerosol generating system. [Figure 6] Figure 6 shows a schematic diagram of one embodiment of a heating element for an aerosol generation system. [Figure 7] Figure 7 shows a schematic diagram of one embodiment of a heating element for an aerosol generation system. [Figure 8] Figure 8 shows a heating element for use in an aerosol generation system. [Modes for carrying out the invention]

[0124] Herein, embodiments of the present invention will be described in detail, albeit only as illustrative examples, with reference to the accompanying drawings.

[0125] Herein, embodiments of the present invention will be described in detail, albeit only as illustrative examples, with reference to the accompanying drawings.

[0126] Figure 1 shows a schematic cross-sectional view of a ceramic heating member 100 according to an embodiment of the present disclosure, in which the heating portion 110 and the porous portion 130 are integrally formed. Referring to Figure 1, the ceramic heating member 100 comprises the heating portion 110, the porous portion 130, and an electrical control circuit (not shown for clarity).

[0127] The porous portion 130 is configured to supply the liquid aerosol-forming substrate to the heating portion 110. Specifically, the porous portion 130 is configured to deliver the liquid aerosol-forming substrate from the liquid storage portion (not shown in Figure 1 for clarity) to the heating portion 110. The porous portion 130 is configured to store some of the liquid aerosol-forming substrate before it is aerosolized by the heating portion 110.

[0128] In this exemplary embodiment, the ceramic heating member 100 is a cylindrical block. The porous portion 130 has a first end and an opposing second end. The first end has an end face which is the liquid-absorbing surface 134, and the second end, which is the heating end, has an interface 114 with the heating portion. In this embodiment, the liquid-absorbing surface 134 is a substantially flat surface. The heating portion has a first end and an opposing second end. The first end has an end face which is the heating surface 113, and the second end, which is the liquid-absorbing end, has an interface 114 with the porous portion. The ceramic heating member 100 also has a side surface that extends between the liquid-absorbing surface 134 and the heating surface 113. The ceramic heating member 100 has a thickness defined between the liquid-absorbing surface 134 and the heating surface 113.

[0129] The porous portion 130 includes a plurality of open pores. The plurality of open pores are interconnected to provide a fluid path for the aerosol-generating liquid to pass through the porous portion 130.

[0130] The open pores are generally axially oriented pores that extend from the liquid-absorbing surface 134 to the interface 114 between the porous portion 130 and the heated portion 110. The pore size of the pores within the porous ceramic body 130 varies between the liquid-absorbing surface 134 and the heated surface 133.

[0131] The porous portion 130 includes a heating end and a liquid absorption end, with the heating surface located at the heating end and the liquid absorption surface 134 located at the liquid absorption end. The porous ceramic body includes a first average pore size at the liquid absorption end and a second average pore size at the heating end. The first average pore size is larger than the second average pore size.

[0132] The first pore size at the liquid absorption end is approximately 150 micrometers. The second pore size at the heating end is approximately 20 micrometers. The pore size changes linearly between the first and second pore sizes, providing a pore size gradient between the liquid absorption end and the heating end of the porous portion 130.

[0133] The pore structure and pore size gradient of the porous portion 130 are achieved by etching the pores into a portion of the silicon carbide.

[0134] The ceramic heating member 100 may be configured such that the liquid flows through the fluid path of the porous portion 130 to the heating portion 110, as indicated by the arrow 170. The porous portion 130 is configured such that the fluid 170 passes from the liquid absorption surface 134 to the interface 114 with the heating portion. The ceramic heating member 100 includes a material that does not chemically interact with the liquid aerosol forming substrate. The ceramic heating member 100 includes, but is not limited to, one or more porous ceramics such as Al2O3, ZrO2, Si3N4, SiC, Ti3AlC2, BN, AlN, SiO2, MgO, mica, diatomaceous earth, silicates, borides, and glass. Naturally, the ceramic heating member 100 may have a different shape or include different materials.

[0135] The heating portion 110 is configured to heat a liquid aerosol-forming substrate in order to form an aerosol. The heating portion 110 is configured to convert electrical energy into thermal energy through the material resistance of the heating portion 110 to electric current. The heating portion 110 is a doped portion of a ceramic heating member. In other words, the heating portion is doped to be conductive.

[0136] In this exemplary embodiment, the heating portion 110 is a porous heating portion.

[0137] The interface 114 between the porous portion and the heating portion does not have to be a clearly defined interface so that the material properties of the interface 114 can transition from the material properties of the heating portion 110 to the material properties of the porous portion 130. In other words, the interface 114 between the heating portion 110 and the porous portion 130 includes a portion of partially doped ceramic material. That is, the edge of the interface 114 adjacent to the heating portion 110 is doped to substantially the same extent as the heating portion 110, and the edge of the interface 114 adjacent to the porous portion 130 is substantially undoped. Therefore, the regions shown in the figures are substantially schematic, and their shapes are not intended to illustrate the actual shapes of regions in the ceramic heating member, nor are they intended to limit the scope of the exemplary embodiments.

[0138] Figures 2A, 2B, and 2C show the power profiles for three different energy supply modes to the ceramic heating element. These profiles show the power supplied to the ceramic heating element over time. In these power profiles, the power changes from high power to low power over the duration of fume absorption. In each of Figures 2A, 2B, and 2C, high power is initially supplied to the ceramic heating element all at once. During the fume absorption process, the supplied power is reduced to provide heat only to the incoming liquid and maintain the heating element at the operating temperature.

[0139] As shown in the power profile in Figure 2A, the ceramic heating element is configured to receive a high power supply for a short period of time at the start of smoke extraction, followed by a lower power supply for a longer period of time.

[0140] As shown in Figure 2B, the ceramic heating element is configured to be supplied with power that changes in three or more stages, from high power to low power, over the duration of smoke extraction.

[0141] As shown in Figure 2C, the ceramic heating element is configured to be supplied with power that decreases as a function of time over the duration of smoke extraction.

[0142] Figure 3 is a schematic diagram of the interior of an aerosol generating system 300 according to one embodiment of the present disclosure. The aerosol generating system 300 comprises two main components: a cartridge 301 and a main body or aerosol generating device 400. The cartridge 301 is detachably connected to the aerosol generating device 400. In this embodiment, the aerosol generating device 400 comprises a power source in the form of a battery 402, which is a rechargeable lithium-ion battery, and a device housing 301 that houses a control circuit 403. The aerosol generating system 300 is portable and has a size comparable to a conventional cigar or cigarette. A mouthpiece is located at the mouth end of the cartridge 301.

[0143] The cartridge 301 comprises a cartridge housing that contains a heating element 100 and a liquid storage section or liquid storage portion 303 for holding a liquid aerosol-forming substrate. The liquid aerosol-forming substrate is carried downward from the liquid absorption surface 134 through the porous portion to the heating element, and when power is supplied to the heating element, the vaporized aerosol-forming substrate is released from the heating surface 133 of the heating element.

[0144] The cartridge 301 includes one or more air intake ports 304 formed within the cartridge housing 305 at positions along the length of the cartridge 301. The aerosol outlet 306 is located in the mouthpiece at the mouth end of the cartridge 301. The one or more air intake ports 304 are in fluid communication with the aerosol outlet 306 to define the airflow path through the cartridge 301 of the aerosol generating system 300. The airflow path flows from the one or more air intake ports 304 to the heating element 100 in the airflow channel. The heating element 100 is arranged to be in fluid communication with the airflow path in the airflow channel. Air enters the one or more air intake ports 304, flows through the airflow channel, passes through the heating element 100, and flows in the mean airflow direction.

[0145] In the embodiment shown in Figure 3, the liquid storage section 303 is arranged around a centrally sealed aerosol channel 307, which has an annular cross-section. When the airflow path reaches the heating member 100, it turns around the side of the heating member 100 and changes direction upward, flowing through the aerosol channel 307 to the aerosol outlet 306.

[0146] The aerosol generating system 300 is configured such that a user can inhale or snort the mouthpiece of a cartridge, thereby drawing an aerosol into their mouth through an aerosol outlet 306. During operation, when a user inhales through the mouthpiece, air is drawn in through one or more air intake ports 304, passes through airflow channels along an airflow path, around the heating element 100, through aerosol channels 307 along an airflow path, and is drawn out to the aerosol outlet 306. The control circuit 403 controls the supply of power from the battery 402 to the cartridge 301 when the system is activated. This consequently controls the amount and characteristics of the vapor produced by the heating element 100. The control circuit 403 includes an airflow sensor (not shown) that supplies power to the heating element 100 when the airflow sensor detects user inhalation. This type of control arrangement is well established in aerosol generating systems such as inhalers and e-cigarettes. When the user inhales vapor through the mouthpiece of cartridge 301, the heating element 100 is activated, generating vapor that is drawn into the airflow path. The vapor is cooled within the airflow path to form an aerosol, which is then inhaled into the user's mouth through the aerosol outlet 306.

[0147] Figure 4 is a schematic cross-sectional view of a portion of an aerosol generating system 500 according to another embodiment of the present disclosure, showing the arrangement of the heating element 200 with respect to the airflow path 520 within the aerosol generating system 500. For simplification, other components of the aerosol generating system are omitted from Figure 4. The heating element 200 in Figure 4 is identical to the heating element in Figures 1 and 2. The aerosol generating system 500 includes a liquid storage portion 522 that holds a liquid aerosol-forming substrate, which is in contact with the liquid-absorbing surface 202b of the porous portion 202. The liquid aerosol-forming substrate is transported from the liquid storage portion 522 through the porous portion 202 to the heating surface 204a of the heating portion 204, as indicated by arrow E. The vaporized aerosol-forming substrate is released from the heating surface 204a through the porous heating portion 204. As indicated by arrow F, the mean vapor release direction is substantially perpendicular to the heating surface 204a of the heating portion 204.

[0148] In the embodiment shown in Figure 4, the heating element 200 is positioned below or to the side of one side of the airflow channel or path 520, which is defined by the airflow channel wall 524. As shown in Figure 4, the left end of the visible portion of the airflow path 520 receives airflow from an air intake (not shown), and the right end of the visible portion of the airflow path delivers airflow to an aerosol outlet (not shown). The heating surface 204a of the heating element 204 is positioned parallel to the airflow path 520 and faces the airflow path 520. The heating element 200 is in fluid communication with the airflow path, as indicated by arrow G, so that the airflow in the airflow path flows through the heating element 200 in the mean airflow direction. The heating element 200 and the airflow path 520 are positioned such that the angle θ between the mean vapor discharge direction F and the mean airflow direction G is approximately 90 degrees, that is, substantially perpendicular to the mean airflow direction G. The average vapor discharge direction F has no velocity or directional component opposite to the average airflow direction G, and therefore the loss of momentum in the airflow is reduced. This reduces the tendency for recirculation and turbulence to occur within the airflow path 520, and the vapor is less likely to collide with the inner surface of the airflow channel wall 524.

[0149] Figure 5 is a schematic cross-sectional view of a portion of an aerosol generating system 600 according to another embodiment of the present disclosure, showing an alternative arrangement of the heating element 200 with respect to the airflow path 620 within the aerosol generating system 600. For simplification, other components of the aerosol generating system are omitted from Figure 6. The heating element 200 in Figure 6 is identical to the heater assembly 200 in Figures 2 and 3. The aerosol generating system 600 includes a liquid storage portion 622 that holds a liquid aerosol-forming substrate in contact with the liquid-absorbing surface 202b of the porous portion 202. The liquid aerosol-forming substrate is transported from the liquid storage portion 622 through the porous portion 202 and the heating portion 204 to the heating surface 204a, as indicated by arrow E. The vaporized aerosol-forming substrate is released from the heating surface 204a through the porous heating portion 204. As indicated by arrow F, the mean vapor release direction is substantially perpendicular to the heating surface 204a of the heating portion 204.

[0150] In the embodiment shown in Figure 5, the airflow channel or path 620 is divided into a first airflow path section 620a and a second airflow path section 620b that pass on both sides of the heating member 200. The first airflow path section 620a and the second airflow path section 620b are merged into a third airflow path section 620c downstream of the heating member 200. The first airflow path section 620a and the second airflow path section 620b receive airflow from one or more air intakes (not shown), and the third airflow path section 620c delivers airflow to an aerosol outlet (not shown). The airflow path 620 is defined by the airflow channel wall 624. The heating surface 202a of the porous body 202 is positioned substantially perpendicular to the airflow path 620 and faces downstream of the airflow path 620. The heating element 200 is in fluid communication with the airflow path, as indicated by arrow G, such that the airflow in the airflow path flows through the heating element 200 in the direction of the average airflow.

[0151] The heating element 200 and the airflow path 220 are arranged such that the angle θ between the mean vapor release direction F and the mean airflow direction G is less than 90 degrees. Upstream of the heating surface 204a of the heating section 204, the mean airflow direction G passing through the heating element 200 is substantially the same as the vapor release direction F. Along the airflow path 620, at the point corresponding to the heating surface 204a, the airflow path 620 narrows inward or tapers off, and at that point, the mean airflow direction G passing through the heating element 200 changes to an angle θ of approximately 45 degrees with respect to the vapor release direction F. Downstream of the heating surface 204a of the heating section 204 in the third airflow path section 620c, the mean airflow direction G of the integrated airflow is also substantially the same as the vapor release direction F. It will be understood that the narrowing or taper of the airflow path 620 may be omitted. In that case, the mean airflow direction G passing through the heating element 100 is substantially the same as the vapor release direction F.

[0152] Figures 6 and 7 show schematic diagrams of one embodiment of a heating element 700 for an aerosol generation system. The heating element includes a heating portion 710 and a porous portion 720.

[0153] The heating portion 710 is configured to vaporize an aerosol-forming substrate, such as a liquid aerosol-forming substrate, to form an aerosol. The heating portion 710 is configured to convert electrical energy into thermal energy through the material resistance of the heating portion 710 to electric current. In this exemplary embodiment, the heating portion 710 is in direct contact with the porous portion 720.

[0154] The porous portion 720 is configured to transport the liquid aerosol-forming substrate to the heating portion 710. In other words, the porous portion 720 supplies the liquid aerosol-forming substrate to the heating portion 710.

[0155] The porous portion 720 has a first end face and an opposing second end. The first end face is the liquid absorption surface 730, and the second end is the heating end 740. In this embodiment, both the liquid absorption surface 730 and the heating end 740 are substantially flat. The porous portion 720 also has a plurality of sides extending between the liquid absorption surface 730 and the heating end 740.

[0156] In this embodiment, as will be discussed in more detail below, the porous portion 720 has a first side surface 750 facing the second side surface 760 and a third side surface 770 facing the fourth side surface 780.

[0157] The porous portion 720 contains a plurality of voids. The plurality of voids are interconnected to provide a fluid path for the liquid aerosol-forming substrate through the porous portion 720 from the liquid absorption surface 730 to the heating end 740. The porous portion 720 is formed from a material that does not chemically interact with the liquid aerosol-forming substrate. In this embodiment, the porous portion 720 is a porous portion and may be formed from, for example, Ca2SiO3 or SiO2 (or Ca2SiO3 and SiO2).

[0158] The heating portion 710 is formed integrally with the porous portion 720. In the embodiments shown in Figures 6 and 7, the heating portion 710 is the doped portion of the heating member.

[0159] The liquid-absorbing surface 730 of the porous portion 720 has a different area from the heating end 740 of the porous portion 720. Specifically, in the embodiments shown in Figures 6 and 7, the area of ​​the heating end 740 is smaller than the area of ​​the liquid-absorbing surface 730.

[0160] In the embodiments shown in Figures 6 and 7, the length of the heating end 740 is shorter than the length of the liquid absorption surface 730, so the heating end 740 has a smaller area than the liquid absorption surface 730. In addition, or alternatively, in another embodiment, the width of the heating end 740 is smaller than the width of the liquid absorption surface 730, so the heating end 740 may have a smaller area than the liquid absorption surface 730.

[0161] In the embodiments of Figures 6 and 7, the porous portion 720 is formed as a trapezoidal prism. With the porous portion 720 having a trapezoidal prism shape, the first side 750 and the second side 760 are both trapezoidal, particularly isosceles trapezoidal, the third side 770 and the fourth side 780 are both rectangular, and the liquid absorption surface 730 and the heating end 740 are both rectangular. In another embodiment, the liquid absorption surface 730 and the heating end 740 may have a square shape.

[0162] The porous portion 720 tapers from the liquid absorption surface 730 towards the heating end 740. In other words, the cross-sectional area of ​​the porous portion 720 gradually decreases from the liquid absorption surface 730 towards the heating end 740. In the embodiments of Figures 6 and 7, the length of the porous portion 720 tapers because it decreases from the liquid absorption surface 730 towards the heating end 740.

[0163] Figure 8 shows a heating element 800 for use in an aerosol generation system. The heating element 800 comprises a heating section 810 for vaporizing a liquid aerosol-forming substrate. The heating element 800 also comprises a porous section 820 for transporting the liquid aerosol-forming substrate to the heating section 810. The porous section 820 has a liquid-absorbing surface 821 and an opposing heating end 822. The heating section 810 is located on the heating end 822 of the porous section 820. The porous section 820 can be made from any suitable ceramic material, such as the materials discussed in any of the above embodiments.

[0164] The heating end 822 of the porous portion 820 is curved. In particular, the heating end 822 of the porous portion 820 is curved convexly in a single transverse direction (first transverse direction).

[0165] The porous portion 820 is prismatic in shape. When viewing a cross-section of the porous portion 820 in the direction of its major axis perpendicular to the curvature direction, the heated end 822 of the porous portion 820 is shown as a circular arc. The porous portion 820 has two symmetrical planes in the direction of its major axis.

[0166] The heating end 822 of the porous portion 820 has a width 823 in the first transverse direction that is substantially the same as the width of the porous portion 820 in the first transverse direction and substantially the same as the width of the heating member 800 in the first transverse direction. The heating end 820 of the porous portion 820 has a width of approximately 5 millimeters in the first transverse direction.

[0167] The heating end 822 of the porous portion has a curvature of approximately 3.6 millimeters. The heating end 822 of the porous portion has a surface area of ​​approximately 28 square millimeters.

[0168] The porous portion 820 comprises four longitudinal surfaces or sidewalls extending from the liquid-absorbing surface 821 to the heating end 822. The four sidewalls are substantially perpendicular to the liquid-absorbing surface 821, which is substantially flat. The liquid-absorbing surface 821 has a square shape.

[0169] The heating portion 810 is a resistance heating portion 810 and is curved. In particular, the curvature of the heating portion 810 is substantially the same as the curvature of the heating end 822 of the porous portion 820. Thus, the heating portion 810 is also curved convexly in a single transverse direction.

[0170] The heating portion 810 is located directly on the heating end 822 of the porous portion 820. The heating portion 810 extends over most of the heating end 822 of the porous portion 820. Substantially, the entire heating portion 810 is in contact with the heating end 822 of the porous portion 820.

Claims

1. A ceramic heating element for an aerosol generation system, A heating section for vaporizing the liquid aerosol-forming substrate, It comprises a porous portion for transporting the liquid aerosol forming substrate to the heating portion, A ceramic heating member in which the heating portion and the porous portion are integrally formed.

2. The ceramic heating member according to claim 1, wherein the porous portion comprises a liquid-absorbing surface and a heating edge, and the heating portion is adjacent to the heating edge of the porous portion.

3. The ceramic heating member according to claim 1 or claim 2, wherein the heating portion is porous.

4. The ceramic heating member according to any one of claims 1 to 3, wherein the heating portion includes a conductive material.

5. The ceramic heating member according to any one of claims 1 to 4, wherein the heating portion and the porous portion are molded as a single monolithic component.

6. The ceramic heating member according to any one of claims 1 to 4, wherein the heating portion is the doped portion of the ceramic heating member.

7. The ceramic heating member according to any one of claims 2 to 6, wherein the liquid-absorbing surface of the porous portion has an area different from the area of ​​the heating end of the porous portion.

8. The ceramic heating member according to any one of claims 2 to 7, wherein the heating end of the porous body is convex in one or both of the first transverse direction and the second transverse direction, and the first transverse direction is perpendicular to the second transverse direction.

9. An aerosol generating system comprising a ceramic heating element according to any one of claims 1 to 8, wherein the heating element is fluid permeable such that vapor is released from the heater assembly in the average vapor discharge direction during use, The aerosol generating system further comprises an air intake and an aerosol outlet, the air intake and the aerosol outlet are in fluid communication, defining an airflow path through the aerosol generating system. An aerosol generating system in which the heater assembly is arranged in fluid communication with the airflow path such that air flows through the heater assembly in the mean airflow direction, and the heater assembly and the airflow path are arranged such that the angle between the mean vapor discharge direction and the mean airflow direction is less than 135 degrees.

10. A method for manufacturing a ceramic heating element for an aerosol generation system, To form a porous ceramic body for transporting a liquid aerosol-forming substrate, A method comprising doping a portion of the porous ceramic body to form a heating portion for vaporizing the liquid aerosol generating substrate.

11. The step of doping a portion of the porous ceramic body is Applying the dopant material to the porous ceramic body, A method for manufacturing a ceramic heating member according to claim 10, comprising heating the dopant material and the porous ceramic body to diffuse dopant ions into the porous ceramic body.

12. The step of doping a portion of the porous ceramic body is The porous ceramic body is brought into contact with a liquid containing a dopant material, Heating the dopant material and the porous ceramic body, A method for manufacturing a ceramic heating member according to claim 10, comprising applying an electric field to diffuse dopant ions into the porous ceramic body.

13. A method for manufacturing a ceramic heating member according to claim 10, wherein the step of doping a portion of the porous ceramic body includes ion implantation.

14. A method for manufacturing a ceramic heating member according to claim 10, wherein the step of doping a portion of the porous ceramic body includes nuclear transmutation.

15. A method for manufacturing a ceramic heating element for an aerosol generation system, The first layer of ceramic material is placed inside the mold, Placing a second layer of ceramic material within the mold, A method comprising forming the first ceramic material layer and the second ceramic material layer in the mold to form a ceramic heating member including a heating portion formed from the first ceramic material layer and a porous portion formed from the second ceramic material layer.

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