Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B3/00—Ohmic-resistance heating
  • H05B3/10—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor
  • H05B3/12—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material
  • H05B3/14—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material the material being non-metallic
  • H05B3/148—Silicon, e.g. silicon carbide, magnesium silicide, heating transistors or diodes
• • A—HUMAN NECESSITIES
  • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
  • A24F—SMOKERS' REQUISITES; MATCH BOXES; SIMULATED SMOKING DEVICES
  • A24F40/00—Electrically operated smoking devices; Component parts thereof; Manufacture thereof; Maintenance or testing thereof; Charging means specially adapted therefor
  • A24F40/20—Devices using solid inhalable precursors
• • A—HUMAN NECESSITIES
  • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
  • A24F—SMOKERS' REQUISITES; MATCH BOXES; SIMULATED SMOKING DEVICES
  • A24F40/00—Electrically operated smoking devices; Component parts thereof; Manufacture thereof; Maintenance or testing thereof; Charging means specially adapted therefor
  • A24F40/40—Constructional details, e.g. connection of cartridges and battery parts
  • A24F40/46—Shape or structure of electric heating means
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B3/00—Ohmic-resistance heating
  • H05B3/40—Heating elements having the shape of rods or tubes
  • H05B3/42—Heating elements having the shape of rods or tubes non-flexible
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
  • H05B2203/011—Heaters using laterally extending conductive material as connecting means
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
  • H05B2203/021—Heaters specially adapted for heating liquids

Definitions

• the present disclosure relates to an aerosol provision device, an aerosol provision system, and a method of controlling an aerosol provision device.
• Smoking articles such as cigarettes, cigars and the like burn tobacco during use to create tobacco smoke. Attempts have been made to provide alternatives to these articles by creating products that release compounds without combusting. Examples of such products are so-called “heat not burn” products or tobacco heating devices or products, which release compounds by heating, but not burning, material.
• the material may be, for example, tobacco or other non-tobacco products, which may or may not contain nicotine.
• an aerosol provision device comprising a heating arrangement configured to heat an aerosol generating material, comprising:
• the rate of heating in the first region and/or the rate of heating in the second region is greater than the rate of heating in the third region for an initial time duration of at least 0.25 seconds, or at least 0.5 seconds, or at least 1.0 seconds, when power is supplied.
• a temperature of the first region and/or a temperature of the second region is greater than a temperature of the third region from at least 0 seconds, or from at least 0.2 second, or at least 0.3 seconds after power is supplied, optionally up to at least 2 seconds or at least 3 seconds or at least 4 seconds, or at least 5 seconds when power is supplied.
• the rate of heating in the first region and/or the second region comprises, for at least an initial time duration (at least initially), a rate of temperature increase of at least 50 degrees Celsius per second, or at least 75 degrees Celsius per second, or at least 100 degrees Celsius per second, or at least 150 degrees Celsius per second.
• the first region and/or the second region reach an operating temperature for aerosol provision faster than the third region.
• the operating temperature reached is least 150 degrees Celsius, or at least 200 degrees Celsius, or at least 250 degrees Celsius.
• the rate of heating in the first region adjacent the first electrical connector for at least an initial time duration (at least initially), differs from the rate of heating in the second region adjacent the second electrical connector.
• the rate of heating in the first region differs from the rate of heating in the second region, from at least 0 seconds, or from at least 0.1 seconds, or from at least 0.2 seconds, or from at least 0.3 seconds after power is provided, optionally up to at least 2 seconds, or at least 3 seconds, or at least 4 seconds, or at least 5 seconds after power is provided.
• the first electrical connector is formed of a different material than the second electrical connector, and/or the first electrical connector contacts the heating element with a different surface area compared to the second electrical connector.
• an amount and/or type of dopant material in the first region differs from an amount and/or type of dopant material in the second region.
• an amount and/or type of dopant material in the first region and/or second region differs from an amount and/or type of dopant material in the third region.
• the first electrical connector and/or the second electrical connector comprises a metal and forms a Schottky Barrier with the semiconductor material of the heating element.
• the semiconductor material comprises at least one of: silicon carbide or gallium nitride.
• the heating element substantially consists of semiconductor material.
• the aerosol provision device is configured to heat a consumable article.
• the aerosol provision device comprises an article receiving portion for receiving, in use, an article comprising an aerosol generating material, and the heating element is configured to heat an article received within the article receiving portion.
• the heating element is hollow and is configured to receive an article.
• the aerosol provision device has a mouth end and a distal end, and the first electrical connector contacts the heating element closer towards the mouth end of the aerosol provision device than the second electrical connector.
• the aerosol provision device comprises a controller configured to control (select) the direction of current flow through the heating element when power is supplied to the heating element, to control a rate of heating in the first region and/or the second region of the heating element.
• the heating element is electrically connected to the power supply by one or more further electrical connectors.
• the aerosol provision device comprises a controller configured to control which of the electrical connectors power is supplied to, and/or configured to control a direction of current flow through the heating element when power is supplied to the heating element.
• an aerosol provision system comprising an aerosol provision device in accordance with the present disclosure, and an article comprising an aerosol generating medium.
• a method of controlling a heating arrangement of an aerosol provision device comprising a heating element comprising a semiconductor material, and a power supply electrically connected to the heating element by two or more electrical connectors, the method comprising: providing power to a first electrical connector and a second electrical connector of the electrical connectors, to cause a first region of the heating element adjacent the first electrical connector and/or a second region of the heating element adjacent to the second electrical connector to heat, for at least an initial time duration, at a greater rate of heating than a third region between the first and second regions.
• the method comprises controlling (selecting) the direction of current flow through the heating element when power is supplied to the heating element, to control a rate of heating in the first region and/or the second region of the heating element.
• the first electrical connector contacts the heating element closer towards a mouth end of the aerosol provision device than the second electrical connector, and the method comprises causing current to flow between the first and second electrical connectors in a direction which causes a greater rate of heating in the first region adjacent the first electrical connector than the second region adjacent the second electrical connector.
• the method comprises subsequently reversing the direction of current flow.
• the method comprises altering the direction of current flow through the heating element to alter the rate of heating in the first region and/or the second region of the heating element.
• the method comprises selecting which electrical connectors to provide power to.
• the method comprises subsequently providing power to a different pair of electrical connectors.
• an aerosol provision device comprising a heating arrangement configured to heat a consumable article, comprising:
• the first electrical connector and/or the second electrical connector comprises a metal and forms a Schottky Barrier with the semiconductor material of the heating element.
• the barrier effect causes heating in a region of the heating element adjacent to the first connector and/or a region of the heating element adjacent the second connector, and also causes heating in a region of the heating element between the first and second electrical connectors.
• the first and second electrical connectors are separated by at most 2 cm, or at most 1 cm, or at most 0.5 cm.
• the heating element has a hollow shape for receiving an article, and the first and second electrical connectors are respectively positioned towards the inside and towards the outside surface of the hollow heating element.
• the heating element is operably connected to the power supply by one or more further electrical connectors.
• the heating element is divided into a plurality of pieces, each operably connected to a power supply by a first electrical connector and a second electrical connector.
• the aerosol provision device comprises a controller configured to control (select) which of the electrical connectors power is supplied to and/or to control (select) a direction of current flow configured through the heating element when power is supplied to the heating element.
• a method of controlling a heating arrangement of an aerosol provision device comprising a heating element comprising a semiconductor material, and a power supply electrically connected to the heating element by a two or more electrical connectors, the method comprising: providing power to a first electrical connector and a second electrical connector of the electrical connectors, to cause heat to be generated in the heating element due to a barrier effect where the first electrical connector contacts the semiconductor material of the heating element, and/or due to a barrier effect where the second electrical connector contacts the semiconductor material of the heating element.
• the method comprises controlling which of the electrical connectors power is supplied to control a location where heat is generated due to barrier effects.
• the method comprises controlling (selecting) the direction of current flow through the heating element when power is supplied to the heating element, to control (select) a rate of heating due to a barrier effect where the first electrical connector contacts the semiconductor material of the heating element, and/or due to control (select) a rate of heating due to a barrier effect where the second electrical connector contacts the semiconductor material of the heating element.
• the present disclosure relates to an aerosol provision device configured to heat an aerosol generating material, an aerosol provision system (including an article comprising an aerosol generating medium), and a method of controlling an aerosol provision device.
• the aerosol provision system is an electronic cigarette, also known as a vaping device or electronic nicotine delivery system (END), although it is noted that the presence of nicotine in the aerosol generating material is not a requirement.
• END electronic nicotine delivery system
• the aerosol provision device is configured for heating, but not burning or combusting, an aerosol-generating material.
• the aerosol provision system is in embodiments a "non-combustible" aerosol provision system (sometimes referred to as “an aerosol provision system” or a “heat-not-burn” system).
• the aerosol provision device is a tobacco heating device.
• the aerosol provision device could alternatively or additionally heat any other suitable and desired aerosol-generating material that is capable of generating aerosol.
• the aerosol provision device comprises a power source (e.g. an energy storage device) and a controller.
• the power source may be configured to provide power to the heating element of the aerosol provision device.
• the controller may control the provision of power to the heating element, for example, as will be described in more detail below.
• the aerosol provision device may comprise any other suitable and desired features that an aerosol provision device typically comprises, such as any one or more of: a housing, a mouthpiece, and a filter.
• Aerosol-generating material is a material that is capable of generating aerosol, for example when heated, irradiated or energized in any other way.
• Aerosol-generating material may, for example, be in the form of a solid, liquid or semi-solid (such as a gel) (or combinations thereof) which may or may not contain an active substance and/or flavourants.
• the aerosol-generating material (which may be heated by aerosol provision device to generating aerosol) may include any plant based material, such as tobacco-containing material and may, for example, include one or more of tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes.
• the aerosol-generating material alternatively or additionally may include other, non-tobacco, products, which, depending on the product, may or may not contain nicotine (and so, for example, could be substantially free from botanical material, for example being substantially tobacco free).
• the aerosol-generating material may for example be in the form of a solid, a liquid, a gel, a wax or the like.
• the aerosol-generating material may for example also be a combination or a blend of materials.
• the aerosol-generating material may also be known as "smokable material".
• the aerosol-generating material may comprise a binder and an aerosol former.
• an active and/or filler may also be present.
• a solvent such as water, is also present and one or more other components of the aerosol-generating material may or may not be soluble in the solvent.
• the aerosol-generating material may comprise or be an "amorphous solid".
• the amorphous solid may be a "monolithic solid".
• the amorphous solid may be a dried gel.
• the amorphous solid is a solid material that may retain some fluid, such as liquid, within it.
• the aerosol-generating material may, for example, comprise from about 50wt%, 60wt% or 70wt% of amorphous solid, to about 90wt%, 95wt% or 100wt% of amorphous solid.
• the aerosol-generating material may comprise an aerosol-generating film.
• the aerosol-generating film may comprise or be a sheet, which may optionally be shredded to form a shredded sheet.
• the aerosol-generating sheet or shredded sheet may be substantially tobacco free.
• the aerosol generating device is configured to receive a consumable article (sometimes referred to as an "article") comprising the aerosol generating material for heating.
• the aerosol provision device may accordingly be configured receive an article within an article receiving portion, and to power the heating element to heat an article received within an article receiving portion.
• An “article” in this context is a component that includes or contains in use the aerosol generating material, which is heated to volatilise the aerosol generating material, and optionally other components in use.
• a user may insert the article into the aerosol generating device before it is heated to produce an aerosol, which the user subsequently inhales.
• the article may be, for example, of a predetermined or specific size that is configured to be placed within a heating chamber of the device which is sized to receive the article.
• an article for use with the aerosol provision device may comprise an aerosol-generating material, and any one or more of: an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol generator, an aerosol generation area, a housing, a wrapper, a filter, a mouthpiece, and/or an aerosol-modifying agent.
• Fig. 1 shows a schematic view of an aerosol provision system 102 according to an embodiment of the present disclosure.
• the aerosol provision system 102 comprises an aerosol provision device 100, in accordance with an embodiment of the invention, together with an article 120 comprising an aerosol generating material.
• the aerosol provision device 100 shown in Fig. 1 comprises an article receiving portion 110 which is configured to receive the article 120 when the aerosol provision device 100 is in use.
• the article receiving portion 110 may be in the form of a cavity or chamber within the aerosol provision device 100 for receiving the article 120 therein. It will be appreciated, however, that the article receiving portion 110 may take any suitable form that is capable of receiving the article 110.
• the article 120 may be separate to (e.g. separable or removable from) the aerosol provision device 100, and may comprise one or more electrical connectors which correspond with one or more electrical connectors of the article receiving portion 110, enabling a circuit of the aerosol provision device 100 to detect when the article 120 is inserted into the article receiving portion 110.
• the article 120 comprises an aerosol generating material, which when heated will produce an aerosol which can be inhaled by a user of the aerosol provision system 102.
• the aerosol generating material may comprise any suitable material.
• the aerosol provision device 100 includes a heating arrangement 125, which is configured to heat the article 120 when received within the article receiving portion 110.
• the heating arrangement comprises a heating element 130 configured to heat up when power is supplied thereto by way of a first electrical connector 131 and a second electrical connector 132 connected to a power supply 150.
• the heating element 130 defines at least part of the article receiving portion 110. In this way, when an article 120 is inserted into the article receiving portion 110 heat is transferred from the heating element 130 to the article 120. In embodiments, the heating element 130 is configured to directly contact the article when inserted.
• the heating element 130 may be hollow and adapted to receive an article 120 therein, for example as is the case for the heating element 130 shown in Fig. 2 .
• the hollow shape of the heating element 130 could be constant in cross sectional area along its longitudinal axis L, for example as shown in Fig. 2 .
• the cross-sectional area could vary along the longitudinal axis L in either a continuous or discontinuous manner, for example tapering towards a proximal (mouth) end 135 of the heating element 130 (so that the cross-sectional area narrows as an article is inserted).
• the hollow heating element 130 is tubular (cylindrical).
• the configuration of a hollow heating element 130 naturally extends to other shaped configurations.
• the heating element 130 may be arranged as a hollow prism, such as a quadrilateral or hexagonal prism (so that the cross section of the tubular heating arrangement a polygon, such as a quadrilateral or a hexagon).
• the shape of the heating element may accordingly be any suitable and desired shape for receiving an article.
• the heating element could be formed of a single (continuous) piece, for example as shown in Fig. 2 .
• the heating element could alternatively be formed of (comprise) plural pieces, which could for example be adjacent and contact one another, or could be separated relative to each another.
• the heating element could comprise one or more hollow pieces positioned along the longitudinal direction L of the heating element, for example as shown in Fig. 3C .
• the heating element could alternatively comprise one or more pieces which are not hollow, e.g. which are planar.
• Fig. 3D shows a heating element formed of a planar piece. Each piece could be placed along (e.g. arranged so as to define) a side of the article receiving portion 110, or multiple sides of the article receiving portion 110.
• the heating element 130 may have substantially the same length as the length L1 of the article receiving portion 110, for example as shown in Fig. 1 .
• heating element Whilst various possible formats for the heating element are discussed above and shown in the figures, any suitable and desired size and shape of heating element could be used, for transferring heat to an aerosol generating material (which aerosol generating material could be provided within an article, or in any other suitable and desired way). As will be appreciated, the skilled person is capable of implementing a variety of configurations for the heating element consistent with the present disclosure.
• the aerosol provision device 100 may comprise a power supply (power source) 150.
• the heating element 130 may be connected to the power supply 150 by (at least) a first electrical connector 131 and a second electrical connector 132.
• the power source 150 may comprise, for example, at least one of: a battery (which may be single use or be rechargeable), a rechargeable capacitor (e.g. a rechargeable super capacitor), a rechargeable solid-state battery (SSB), a rechargeable lithium-ion battery (LiB) or the like, a hermetically sealed battery, a pouch cell battery or some combination thereof.
• a battery which may be single use or be rechargeable
• a rechargeable capacitor e.g. a rechargeable super capacitor
• SSB rechargeable solid-state battery
• LiB lithium-ion battery
• the power source 150 may be charged by plugging a power supply into the aerosol provision device 100, or the power source 150 may be replaceable, e.g. in the form of a replaceable battery.
• the aerosol provision device 100 may also comprise a controller 160 for controlling the provision of power from the power source 150 to the heating element 130, for example as will be described in more detail below.
• the heating element 130 could be connected to the power supply (power source) 150 by more than two electrical connectors (by the first electrical connector 131, the second electrical connector, and one or more further electrical connectors). In that case, in use, a pair of electrical connectors to supply power to may be selected (by the control circuit 160).
• connection between the power source 150, the electrical connectors 131, 132 and the control circuit 160 is not shown in the figures, however these components could be electrically connected in any suitable and desired way.
• aerosol provision device 100 Various other components may be included in the aerosol provision device 100, such as an activation switch or button, and any other components common to aerosol provision devices. However, for the sake of brevity, these components are not discussed here. Notwithstanding this, the skilled person would readily appreciate, if necessary, how to utilise some or all of these components when implementing the present invention.
• the heating element comprises a semiconductor material.
• the Applicant has recognised that semiconductor material can be used to generate heat resistively by causing current to flow through it (by providing power to the semiconductor material via electrical connectors), so that a semiconductor material can advantageously be used in the heating element 130 of an aerosol generating device 100 to generate heat.
• the heating element comprising the semiconductor material may thus be considered to form a resistive heating element.
• the Applicant has furthermore recognised that barrier effects (e.g. potential energy differences) arising between the semiconductor material of the heating element and the electrical connector(s) can surprisingly contribute to heating in the vicinity of the electrical connector(s) when power is supplied, and can advantageously be used to generate additional heat adjacent the electrical connectors.
• barrier effects e.g. potential energy differences
• the Applicant has found that formation of a Schottky barrier (as the barrier effect), between the semiconductor material of the heating element and an electrical connector formed of metal, is particularly effective for providing additional heat.
• barrier effects e.g. such as a Schottky barrier
• barrier effects between the semiconductor material of the heating element and one or more of the electrical connectors can advantageously be used to provide additional heat where it is needed most.
• additional heat can be generated adjacent an electrical connector positioned near a proximal (mouth) end of the heating element, to reduce time to first puff of aerosol.
• selecting by the control circuit) which electrical connectors of a plurality of electrical connectors to supply power to, can allow additional heat generation adjacent those particular selected electrical connectors (and so provide additional heat to corresponding regions of an article, e.g. to control generation of aerosol from those regions of the article).
• the heating element and electrical connectors are configured so as to provide a variation in the rate of heating throughout the heating element, with a greater rate of heating in regions adjacent either or both of the electrical connectors to which power is provided compared to a region between the electrical connectors.
• the heating element and electrical connectors may be configured such that, when power is supplied, (substantially the entirety of) the region between the electrical connectors is heated as a result of barrier effects where those electrical connectors contact the semiconductor material of the heating element.
• the barrier effects contribute a greater amount of heat to the region between the electrical connectors compared to resistive heating effects). This could be done, for example by positioning the electrical connectors in relatively close proximity to one another.
• heating due to barrier effects can be tailored by configuring the electrical connectors (e.g. shape, size, material, etc.), by configuring the semiconductor (e.g. shape, size, material, amount of doping, etc.), and also by controlling the direction of current flow across the junction between the semiconductor material an electrical connector.
• the electrical connectors e.g. shape, size, material, etc.
• the semiconductor e.g. shape, size, material, amount of doping, etc.
• Example heating elements, and electrical connector configurations, and control schemes, are discussed in more detail below.
• Figs. 4A and 4B are images from a thermal video recording the temperature of a tubular heating element 130 (having the shape illustrated in Fig. 2 ) formed of silicon carbide (SiC) semiconductor material in response to supplying power to first and second electrical connectors 131, 132 which are formed of metal and positioned at respective longitudinal ends 135, 136 of the tubular heating element.
• a tubular heating element 130 having the shape illustrated in Fig. 2
• SiC silicon carbide
• Fig. 4A is an image showing the temperature of the heating element after 1 second of providing power to the electrical connectors.
• Figure 4B shows the temperature after 5 seconds of providing power.
• the dark circle in Fig. 4A at point Sp4 is a drop of water placed on the heating element, which has evaporated by 5 seconds and so is absent from Fig. 4B . Prior to providing power, the heating element was at room temperature.
• the temperature in a first region "a" adjacent the first electrical connector 131 and the temperature in a second region "b" adjacent the second electrical connector 132 is greater than a temperature in a third region "c" between the first and second regions.
• the heating element may reach an essentially uniform temperature.
• the additional heating (at least initially) in the regions “a" and “b" adjacent the electrical connectors, is due to the Schottky barrier formed between the semiconductor heating element and each of the metal electrical connectors.
• heating is primarily due to resistive heating arising as a result of current flow through the semiconductor.
• Fig. 5 is a graph showing in more detail the change in temperature in the regions "a", “b” and “c", as a function of time as power is supplied to the heating element.
• Fig. 5 shows the temperature at point Sp3 in the first region "a”, at point Sp1 in the second region "b", and at point sp2 in third region "c".
• the temperatures for these points are derived from the thermal video.
• the rate of heating (rate of temperature increase) in the first region "a" (measured at Sp3) and the rate of heating in the second region "b" (measured at Sp1) are greater than the rate of heating in the third region "c" (measured at Sp2).
• the rate of temperature increase in regions "a" and “b” is greater than 150 degrees Celsius per second, whereas in region "c" the rate of temperature increase is less than 150 degrees Celsius per second.
• the rate of heating may start to equalise between the regions, which may be due to the amount of heat generated due to barrier effects changing as temperature increases.
• the heating element is substantially of a uniform temperature.
• the rate of heating (and temperature) in the region "a" adjacent the positive electrical connector is greater than the rate of heating (and temperature) in the region "b" adjacent the negative electrical connector (measured at Sp1).
• Figs. 4A, 4B and 5 The arrangement shown and described with respect to Figs. 4A, 4B and 5 is an example of an arrangement for the heating element and electrical connectors consistent with the present disclosure.
• the present disclosure is not so limited, and various features of the heating element and electrical connectors can be modified within the scope of the present disclosure, for example as will be described in more detail below.
• the present disclosure provides a heating arrangement for an aerosol provision device, comprising a heating element comprising semiconductor material, and first and second electrical connectors, which are configured so that when power is supplied to the electrical connectors, a rate of heating in a first region adjacent the first electrical connector and/or a rate of heating in a second region adjacent the second electrical connector is, for at least an initial time duration (at least initially), greater than a rate of heating in a third region between the first and second regions.
• the additional heating in the first and/or second regions compared to the third region is due to barrier effects (e.g. a Schottky Barrier) between the semiconductor material of the heating element and either or both of the electrical connector(s) (whereas the third region is heated is primarily due to resistive heating).
• barrier effects e.g. a Schottky Barrier
• the first region adjacent the first electrical connector, the second region adjacent the second electrical connector and the third region between the first and second regions can be any suitably defined region obeying the rate of heating relationship mentioned above.
• the first, second, and third regions are in embodiments directly adjacent one another (for example as illustrated by regions "a", "b", and "c" of Figs. 4A and 4B ).
• the first, second and third regions may be defined within a continuous heating element (comprising a single, continuous, piece of material) (for example as illustrated in Figs. 4A and 4B ). Each of the first, second and third regions may be a continuous region of the heating element.
• the heating element may differ in size (e.g. cross-sectional shape, cross-sectional area, thickness, or any other shape parameter) and/or material properties (e.g. a type of semiconductor material, an amount of dopant material, a type of dopant material, or any other material property) between any of the first, second and third regions.
• size e.g. cross-sectional shape, cross-sectional area, thickness, or any other shape parameter
• material properties e.g. a type of semiconductor material, an amount of dopant material, a type of dopant material, or any other material property
• Fig. 7C shows a heating element 130 which differs in size (cross sectional area) between the first region “a” (adjacent the first electrical connector 131), the second region “b” (adjacent the second electrical connector 132), and the third region “c" (between the first and second regions).
• Fig. 7D for example shows a heating element 130 which has a greater amount of dopant material 170 in the second region “b” compared to the first region "a” and third region "c".
• the temperature of the heating element is not necessarily constant in each of the first, second and third regions.
• a continuous variation in temperature across the heating element may arise, for example as shown in Fig. 4A .
• the first and second regions of the heating element are 'adjacent' the respective first and second electrical connectors, in the sense that they generally approach (e.g. extend outwards from) the first and second electrical connectors respectively.
• the rate of heating (or the temperature) of the heating element is for at least an initial time duration (at least initially) greater in the first region adjacent the first electrical connector and/or the second region adjacent the second electrical connector, compared to the third region. This relationship is maintained for a period of time commencing when power is supplied to the heating element (and throughout which power is supplied).
• power may be supplied to commence a session of usage of the aerosol provision device, or power may be supplied within a session of usage of the aerosol provision device.
• the heating element may be at approximately room temperature (approximately 25 degrees Celsius). Alternatively, immediately before power is supplied, the heating element could be at an elevated temperature compared to room temperature (but which is less than an operating temperature for the aerosol provision device).
• the rate of heating of the heating element is greater in the first region adjacent the first electrical connector and/or the second region adjacent the second electrical connector, compared to the third region, for at least an initial period (time duration) of 0.25 seconds, or 0.5 seconds, or 1.0 seconds during supply of power. After this time, the rate of heating in one or more of the regions may begin to equalise.
• the rate of temperature increase in the first region and/or the second region is, for at least an initial time duration (at least initially), at least 50 degrees Celsius per second, or at least 75 degrees Celsius per second, or at least 100 degrees Celsius per second, or at least 150 degrees Celsius per second.
• the temperature of the heating element when supplying power, is greater in the first region adjacent the first electrical connector and/or the second region adjacent the second electrical connector, compared to the third region, for an initial period of time from at least 0 seconds, or from at least 0.1 seconds, or at least 0.2 seconds, or at least 0.3 seconds during supply of power, in embodiments up to at least 2 second, or at least 3 seconds, or at least 4 seconds, or at least 5 seconds during supply of power (after supply of power commences). In embodiments, in this period of time, sufficient heat is provided from the first and/or second regions (but, in embodiment, not from the third region) to generate an aerosol.
• the first region and/or the second region reach an operating temperature for aerosol provision faster than the third region.
• the operating temperature for generating aerosol may be, for example, at least 150 degrees Celsius, or at least 200 degrees Celsius, or at least 250 degrees Celsius.
• the heating element 130 is formed of a single piece of silicon carbide (SiC) semiconductor material.
• SiC silicon carbide
• the Applicant has found silicon carbide to be useful for providing resistive heating and also providing heating due to barrier effects at the electrical connectors.
• Another semiconductor which may be useful for this purpose is gallium nitride. Other semiconductors could be used for this purpose, however, if desired.
• the heating element comprises a semiconductor material comprising silicon carbide and/or gallium nitride.
• the semiconductor material may be doped.
• the semiconductor material comprises silicon carbide
• it may be doped with nitrogen or phosphorous, in order to make a n-type semiconductor.
• the silicon carbide could be doped with beryllium, boron, aluminium or gallium to form a p-type semiconductor. Obtaining a p-type or an n-type semiconductor will result in a respective decrease or increase in conductivity of the doped semiconductor when heated.
• heating element may be understood as corresponding to that element which generates heat when power is supplied to it, for example to heat an article inserted into the aerosol generating device.
• the heating element could be formed entirely of semiconductor material (which may or may not be doped), and is embodiments this is done. In such embodiments, heat is generated in the heating element only as a result of power being supplied to the semiconductor material via the electrical connectors.
• the heating element (which may have any of the shapes discussed above, for example) is formed of a single piece of semiconductor material. However, it could alternatively be formed of plural pieces semiconductor material.
• the heating element may be configured such that semiconductor material of the heating element contacts at least one electrical connector formed of metal (so as to create a Schottky Barrier to generate heat when power is provided to the heating element via the electrical connector).
• the heating element could comprise, in addition to semiconductor material, one or more other materials, for example such as one or more materials conventionally used in resistive heating elements (such as for example a metal, metal alloy, a ceramic material, or other suitable and desired material).
• a piece of semiconductor material could be placed in contact with at least one (e.g. each) of the electrical connectors (whereas one or more other (conductive) materials are provided elsewhere in the heating element, e.g. between the semiconductor material)).
• the electrical connectors could (each) interface with semiconductor material which is coupled (at least in part) with a cheaper conductive material in between.
• each of the electrical connectors of the same material (e.g. of a same metal), and in embodiments this is done.
• both electrical connectors 131 and 132 are formed of a same metal.
• a pair of nickel connectors, and a pair of copper connectors were used during the testing.
• any suitable and desired metal could be used for one or more of (e.g. both of) the electrical connectors, such as one or more of (or combinations of): nickel, copper, molybdenum, platinum, chromium, tungsten, and aluminium.
• Other materials capable of forming a Schottky Diode with a semiconductor material (and which could be used one or more of (e.g. both of) the electrical connectors) include metal silicides, such as palladium silicide and platinum silicide.
• one or more of the electrical connectors may be formed of different materials.
• one or more of the electrical connectors could be formed of a different metal to at least one other electrical connector.
• the Applicant has found that different metals create a Schottky Barrier (potential energy barrier) of a different height, and so generate a different amount of heat in the heating element when power is provided. As such, by selecting appropriate metals for the electrical connectors the amount of heat generated in the regions adjacent electrical connectors when power is supplied, can be tailored.
• each electrical connector contacts the heating element (by forming each electrical connector of metal directly contacting semiconductor material of the heating element), and in embodiments this is done.
• a Schottky barrier is formed only at one or more of (a subset of) the electrical connectors, with no Schottky barrier being formed at the other one or more of (subset of) electrical connectors, and in embodiments this is done.
• a Schottky barrier may be formed between the heating element and only one of the first and second electrical connectors 131, 132.
• a first electrical connector 131 near the mouth end 135 of the heating assembly 130 may form a Schottky barrier, to provide a reduced time to first puff (whereas a second electrical connector 132 nearer the distal end 136, or indeed any other electrical connectors, may not form a Schottky barrier).
• the amount of heat generated (rate of temperature increase) in a region adjacent an electrical connector which does not form a Schottky barrier will be less than the amount of heat generated (rate of temperature increase) in a region adjacent an electrical connector does form a Schottky barrier.
• a Schottky barrier may be prevented, for example, and in embodiments, by forming one or more of the electrical connectors of an electrically conductive material which is not a metal (e.g. an electrically conductive ceramic, or other electrically conductive material).
• an electrically conductive material which is not a metal (e.g. an electrically conductive ceramic, or other electrically conductive material).
• a Schottky barrier may be prevented, in embodiments, by preventing the semiconductor material of the heating element from contacting one or more metal electrical connectors, for example by positioning a conducting material which is not metal (e.g. an electrically conductive ceramic, or other electrically conductive material) between the semiconductor material of the heating element and the electrical connector.
• a conducting material which is not metal (e.g. an electrically conductive ceramic, or other electrically conductive material) between the semiconductor material of the heating element and the electrical connector.
• the amount of heat (the rate of temperature increase) generated in the region adjacent the electrical connector due to the barrier effects (e.g. Schottky barrier) may be tailored in various ways, for example, by appropriately selecting one or more of: the material of the electrical connector; the surface area of the electrical connector; the shape of the heating element in the region adjacent the electrical connector; the material properties of the heating element in the region adjacent the electrical connector; and the direction of current flow in the heating element (the direction of current flow across the junction between the electrical connector and the semiconductor material of the heating element).
• one of more of the electrical connectors differ in one or more of: surface area (size and/or shape), and material.
• Figs. 7A and 7C shows heating elements 130 provided with electrical connectors 131 and 132 that differ in size.
• the shape of the heating element is not uniform, in embodiments such that the shape of the heating element differs among one or more of the regions adjacent the electrical connectors.
• the heating element could differ in any one or more of: cross-sectional shape; cross-sectional area; thickness, or any other shape parameter.
• Fig. 7C shows a heating element 130 which varies in cross-sectional area, tapering towards a mouth end 135, so that the heating element has a cross-sectional smaller area in the region adjacent the first electrode 131 compared to the region adjacent the second electrode 132.
• one or more material properties of heating element are not uniform, in embodiments differing among one or more of the regions adjacent the electrical connectors. For example, there could be difference in one or more of: a type of semiconductor material; an amount of dopant material; a type of dopant material; or any other material property of the heating element.
• Fig. 7D shows a heating 130 arrangement in which the amount of dopant material 170 varies within the heating element, the heating element being doped more heavily towards one of the electrical connectors 132 compared to another electrical connector 131.
• a shape and/or material property of the heating element varies (differs) among one or more of the regions adjacent the electrical connectors (for example differing in a first region adjacent a first electrical connector compared to a second region adjacent a second electrical connector to which power is provided).
• a shape and/or material property of the heating element varies (differs) in one or more of the region adjacent the electrical connectors compared to regions between those electrical connectors (for example differing in a first region adjacent a first electrical connector and/or a second region adjacent a second electrical connector, compared to a third region between the first and second regions).
• the shape and/or material property of the heating element which differ may be any of those described above.
• the direction of current flow across the junction between the semiconductor and the electrical connector can also affect the rate of heating in the region adjacent the electrical connector.
• rate of heating in a first region adjacent a first electrical connector differs from a rate of heating in a second region adjacent a second electrical connector, in embodiments at least in part due a difference in the direction of current flow across the junction between the semiconductor material of the heating element and the electrical connector.
• the rate heating in the regions adjacent respective electrical connectors may differ (for example with a rate of heating in a first region adjacent a first electrical connector, differing from the rate of heating in the second region adjacent the second electrical connector).
• the rate of heating may differ for at least an initial time duration (at least initially) when power is provided to the electrical connectors.
• the rate of heating may begin to equalise over time. This is illustrated, for example, in Fig. 5 .
• the rate of heating (rate of temperature increase) in a first region adjacent a first electrical connector differs from the rate of heating in a second region adjacent a second electrical connector, for a period (for an initial time duration) of at least 0.1 seconds, or least 0.2 seconds, or at least 0.3 seconds during which power is supplied, in embodiments up to at least 2 seconds, or at least 3 seconds, or at least 4 seconds, or at least 5 seconds.
• first and second electrical connectors Whilst the above discussion has referred to first and second electrical connectors, more than two electrical connectors could be provided (so that the heating arrangement also comprises one or more further electrical connectors). The above discussion equally applies to any additional electrical connectors (so that barrier effects, e.g. Schottky barrier, may arise in the region adjacent any electrical connector, and for example by tailored as discussed above).
• barrier effects e.g. Schottky barrier
• Fig. 3B shows a heating element 130 with more than two electrical connectors 131, 132, 133.
• a heating element could be formed by positioning the electrical connectors on a surface of a heating element formed of a single (undivided) piece of material, or could be formed by positioning electrical connectors between adjacent pieces of material of the heating element.
• Fig. 3C shows another example of a heating element a heating element 130 with more than two electrical connectors.
• the heating element is divided into plural pieces 133', each having a respective pair of electrical connectors 131 and 132, and 131' and 132'.
• any pair of the electrical connectors can be referred to as a notional 'first' electrical connector, and 'second' electrical connector to which power may be applied, and may have any of the features discussed above.
• power could be applied to 'first' electrical connector 131, and 'second' electrical connector 132, with electrical connector 133 not being provided with power.
• power could be applied to electrical connector 132 as the 'first' electrical connector, and to electrical connector 133 as the 'second' electrical connector with electrical connector 131 not being provided with power, or any other suitable and desired permutations in which a pair of the electrical connectors forming a 'first' and 'second' electrical connector are provided with power.
• the first and second electrical connectors are configured so that the first electrical connector 131 is closer towards the mouth end 135 of the heating element (closer towards a mouth end of the aerosol provision device) than the second electrical connector 132. This may allow a greater rate of heating to be provided in the first region adjacent the first electrical connector (near the mouth end of the heating element (aerosol provision device)), for example compared to a rate of heating in the second region adjacent the second first electrical connector and/or compared to a rate of heating in the third region between the first and second regions. This may allow a relatively fast time to first puff of aerosol.
• the electrical connectors are spaced along the longitudinal axis L of the heating element 130.
• An example such configuration is shown in Fig. 3B .
• electrical connectors could be provided at any suitable and desired position, for example wherever it is desired to provide additional heating due to barrier effects.
• Figs. 3A to C and Figs. 7A to D show a pair of electrical connectors positioned at the distal ends 135, 136 of the heating element 130
• electrical connectors could be placed at any other suitable and desired locations of the heating element.
• electrical connectors could instead be positioned near (for example, inwards of) the distal ends of the heating element.
• FIG. 7B illustrates first and second electrical connectors 131, 132 which do not encircle the heating element.
• the heating element and electrical connectors may be configured such that, when power is supplied, a rate of heating in a first region adjacent a first electrical connector and/or a rate of heating in a second region adjacent a second electrical connector is, for at least an initial time duration (at least initially), greater than a rate of heating in the third region.
• the electrical connectors may be spaced far enough apart that there is a variation it the rate of heating at different locations of the heater, with regions adjacent either or both the electrical connectors being additionally heated due to barrier effects (e.g. Schottky barrier), a region away from the electrical connectors is not heated by barrier effects and so has a lesser rate of heating.
• this variation in heating may advantageously be used to selectively heat certain regions of the heating element.
• one or more electrical connectors are separated by a distance of at most 2 cm, or at most 1 cm, or at most 0.5 cm.
• first electrical connector 131 on an interior surface of a hollow heating element
• second electrical connector 132 on an exterior surface of the hollow heating element.
• the first and second electrical connectors could cover the entire interior surface and the entire exterior surface respectively of the heating element, for example as shown in Fig. 8B .
• first and second electrical connectors could cover only part of the entire interior surface and exterior surface of the heating element.
• first and second electrical connectors 131, 132 which are positioned in close proximity along the longitudinal axis L of the heating element 130, for example as shown in Fig. 8A .
• These could be provided in combination with one or more additional electrical connectors 133 which are spaced further apart (and for which the rate of heating varies in the region between those electrical connectors compared to in the region(s) adjacent those electrical connectors).
• the aerosol provision device may be controlled by a controller 160.
• the controller may be configured to select which 'first' and 'second' electrical connectors to provide power to (so as to generate heat due to barrier effects at either of both of the selected electrical connectors).
• the controller may also be configured to control the direction of current flow to affect the amount of heat generated due to barrier effects (and so control a rate of heating in a first region adjacent a first electrical connector and/or a second region adjacent a second electrical connector).
• FIG. 9 is a flowchart showing example control steps when operating a heating element in accordance with embodiments of the present disclosure.
• step 90 when it is desired to heat a region of the heating element (step 90), which pair of 'first' and 'second' electrical connectors are to be provided with power is selected, and optionally a direction for current flow is selected, and power is provided accordingly (step 91). If it is subsequently desired to heat a different region of the heating element (step 92), then it is determined whether a different pair of electrical connectors should be provided with power and/or whether current should be caused to flow in a different direction, and power is provided accordingly (step 93).
• current when controlling an aerosol provision device in accordance with the present disclosure, current may be caused to flow in a first direction in the heating element, and then subsequently be caused to flow in a different (opposite) direction. This may be done, for example, to initially create a greater rate of heating in a first region adjacent a first electrical connector compared to a second region adjacent a second electrical connector, and to then change the direction of current flow (without changing the electrical connectors which power is provided to) to create a greater at in the second region than the first region.
• which electrical connectors power is provided to and/or the current flow may initially be selected to provide a greater rate of heating at a mouth end of the heating element compared to a distal end of the heating element (and then be changed to create a greater rate of heating at the distal end of the heating element compared to the mouth end of the heating element). This may assist with providing a faster time to first puff.
• FIGs. 6A This is illustrated in Figs. 6A , in which current is initially provided in a direction which causes a greater rate of heating at the mouth end 135 of the heating element than at the distal end 136 (for example with an electrical connector at the mouth end forming a positive junction, and an electrical connector at the distal end forming a negative junction).
• the current of current flow may then be reversed to cause a greater rate of heating at the distal end 136 of the heating element compared to the mouth end 135 of the heating element.
• a region which is desired to be heated adjacent an electrical connector may provide a better (e.g. greater) rate of heating if the current is provided in a particular direction which may be opposite to the direction of current flow previously.
• Which electrical connectors power is provided to and/or the current flow could be changed within a session of usage (whilst an article remains inserted), to alter the rate of heating in different regions of the heating element (and any article therein).
• the electrical connectors which power is provided to and/or the direction current flow could remain constant for an initial, e.g. selected, e.g. predetermined, period of time, before they are (permitted to be) changed.
• the electrical connectors which power is provided to and/or the direction of current flow could be changed between sessions of usage (when a different article is inserted), for example to tailor aerosol generation to desired user experience of each usage sessions and/or to tailor the heating to differently configured articles.

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• 2024
  • 2024-03-01 EP EP24160884.3A patent/EP4611481A1/de active Pending
• 2025
  • 2025-02-18 WO PCT/EP2025/054306 patent/WO2025180894A1/en active Pending

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