Patent Publication Number: US-2020288770-A1

Title: Mouthpiece assembly

Description:
PRIORITY CLAIM 
     The present application is a National Phase entry of PCT Application No. PCT/EP2018/079137, filed Oct. 24, 2018, which claims priority from GB Patent Application No. 1717497.0, filed Oct. 24, 2017, each of which is hereby fully incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a mouthpiece assembly for an aerosol provision device for generating an inhalable medium. 
     BACKGROUND 
     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 that burn tobacco by creating products that release compounds without burning. 
     Examples of such products are heating devices which release compounds by heating, but not burning, the material. The material may be for example tobacco or other non-tobacco products, which may or may not contain nicotine. 
     As another example, there are so-called e-cigarette devices. These devices contain an aerosolizable substance, typically a liquid, which is heated to be vaporized to produce an inhalable vapor or aerosol. The liquid may contain nicotine and/or flavorings and/or aerosol-generating substances, such as glycerol. Such known e-cigarette devices typically do not contain or use tobacco. 
     As yet another example, there are so-called hybrid devices. These hybrid devices typically contain separately an aerosolizable substance, again typically a liquid, and a container for a material. In typical examples the material may be tobacco or other flavor material. The liquid is aerosolized to produce an inhalable vapor or aerosol which passes through the container for a material so that a property, such as a flavor, is imparted to the vapor or aerosol by the material before being inhaled by a user. 
     In a hybrid device, the aerosolizable material may be provided in a cartridge, typically a liquid cartridge. It may be desirable to be able to detach this cartridge from a body portion of the device, and some known hybrid devices allow a cartridge to be detached from a body portion in order to replace or refill the cartridge. For example, the cartridge may be replaced or refilled when the liquid in the cartridge is depleted, or when the user wishes to change the type of liquid being used in the device. 
     It is also known for the container for a material to be releasably attached to the device. This might be, typically, to replace the material when it is no longer having the desired effect on the aerosol passing through the chamber. It may also be when the user wishes to change the type of material used. The user may then supply a new container with fresh material, or a different material, or the container may be refilled with a material and reattached to the device. Alternatively, in known devices, the container may not be attachable from the device and may be refilled with material while remaining attached to the device. 
     It is often the case that it is desirable to replace the material more frequently than the cartridge. A reason for this, among others, is that the container is often smaller than a liquid reservoir of the cartridge, and the volume of material held in the container may be less than the volume of liquid held in the cartridge. It is then desirable to be able to detach a container for a material from the hybrid device while leaving the liquid cartridge attached to the body portion of the device. In a typical hybrid device with a releasably attached material container, the container, being downstream of the liquid cartridge, is releasably attached to the cartridge, rather than to any other part of the device. 
     SUMMARY 
     According to a first aspect of the present disclosure, there is provided a mouthpiece assembly for an aerosol provision device, the mouthpiece assembly comprising: a first housing for being received, in use, in a mouth of a user; a second housing for containing a material through which, in use, an aerosol generated by the aerosol provision device flows before passing out of the mouthpiece assembly for inhalation by the user; and wherein the first housing and the second housing are connected together to form the mouthpiece assembly and the mouthpiece assembly is configured to be releasably connectable to a section of the aerosol provision device. 
     The mouthpiece assembly may comprise at least a first barrier that is porous to the flow of aerosol and which prevents material in the second housing from exiting the second housing. 
     The first barrier may be arranged towards a first opening at a proximal end of the second housing. 
     The mouthpiece assembly may comprise a second barrier that is porous to the flow of aerosol and which prevents material in the second housing from exiting the second housing, wherein the second barrier is arranged towards a second opening at a distal end of the second housing. 
     The second housing may be a tube and wherein first opening is at the proximal end of the tube and the second opening is at the distal end of the tube. 
     The second housing may comprise a first portion that is within the first housing and a second portion that extends out of the first housing, wherein the second portion is within the aerosol provision device when the mouthpiece assembly is connected to the section of the aerosol provision device. 
     The mouthpiece assembly may be configured to be releasably connected to the section of the aerosol provision device via a push fit connection. 
     The mouthpiece assembly may comprise at least one first surface formation which is configured to interface with an inner surface of the section of the aerosol provision device. 
     At least one of the at least one first surface formations may be configured to interact with a corresponding second surface formation on the inner surface of the section of the aerosol provision system. 
     According to a second aspect of the disclosure there is provided a method of manufacturing a mouthpiece assembly according to the first aspect, the method comprising: providing the first housing; providing the second housing; providing the material into the second housing; and connecting the first housing and the second housing. 
     Connecting the first housing and the second housing may comprise push-fitting. 
     Attaching the first housing and the second housing may comprise applying adhesive between contacting surfaces of the first housing and the second housing. 
     Attaching the first housing and the second housing may comprise ultrasonic welding. According to a third aspect of the disclosure there is provided an aerosol provision device comprising a mouthpiece assembly according to the first aspect and a device body. 
     The device may further comprise a cartridge, wherein the mouthpiece assembly is releasably connected to the cartridge. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1  shows a schematic longitudinal cross-sectional illustration of an aerosol provision device for generating an inhalable medium, wherein the device is shown in a vertical orientation. 
         FIG. 2  shows a perspective view of an example of the device of  FIG. 1 , wherein the device is shown in a horizontal orientation with a mouthpiece assembly detached from the rest of the device.] 
         FIG. 3  shows a first example of a cartridge attached to a mouthpiece assembly. 
         FIG. 4 a    shows a perspective view of a mouthpiece assembly, while  FIG. 4 b    a perspective view of the same assembly with the mouthpiece detached in order to show details of the second housing. 
         FIG. 5  shows a second example of a cartridge attached to a mouthpiece assembly. 
         FIG. 6 a    shows a perspective view of a second example mouthpiece assembly, while  FIG. 6 b    a perspective view of the second mouthpiece assembly with the mouthpiece detached in order to show details of the second housing. 
         FIG. 7  shows a longitudinal cross-sectional view of the mouthpiece assembly of  FIGS. 6 a    and  6   b.    
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a schematic of an aerosol provision device  100  is illustrated. The aerosol provision device  100  is an inhalation device (i.e. a user uses it to inhale an aerosol provided by the system  100 ) and the device  100  is a hand-held device. In this example, the device  100  is an electronic device. 
     In broad outline, the device  100  volatilizes an aerosol provision material  20  provided in a cartridge  200 . In this example the aerosol provision material  20  is a liquid, for example, an e-cigarette liquid, however in other examples the aerosol provision material may any other type of aerosolizable material, such as a gel. The device  100  in the example is a so-called hybrid device since any aerosol and/or vapor produced from the cartridge  200  passes through a material chamber  430  for containing a material  30  before being inhaled by a user. 
     The material  30  may impart to or modify a property, for example the flavor, of the vapor and/or aerosol before the vapor and/or aerosol passes out of the device  100  for inhalation by a user. The material  30  may, for example, consist of or comprise tobacco. As the aerosol passes through and over the material  30 , for example tobacco, the aerosol entrains organic and other compounds or constituents from the material  30  that lend the material  30 , for example tobacco, its organoleptic properties, thus imparting the flavor of the material  30  to the aerosol as it passes through the material chamber  430 . 
     Suitable examples of the material  30  may comprise tobacco per se, different varieties of tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco, ground tobacco, tobacco extract, homogenized tobacco or tobacco substitutes. In the case of tobacco, the material  30 , etc. may be in the form of a rod of tobacco, a pod or plug of tobacco, loose tobacco, agglomerates, etc., and may be in relatively dry form or in relatively moist form for example. The material  30  may be in the form of a plug of tobacco rod which is cut to length and placed into the material chamber  430 . The material  30  may include other, non-tobacco, products, which, depending on the product, may or may not contain nicotine. 
     The material  30  may be for modifying a property of the aerosol other than (or in addition) to flavor. 
     In some examples, the material  30  may be or include a substance that modifies one or more other organoleptic properties of the aerosol (e.g. modifying the feel or smell or look of the aerosol to the user). 
     In some examples, the material  30  may be or include a substance that modifies the PH of the aerosol by either lowering or raising the PH (e.g. modifying the acidity or the basicity of the aerosol). 
     In some examples, the material  30  may be or include a substance that modifies (e.g. reduces) the amount of aldehydes in the aerosol. 
     In some examples, the material  30  may be or include a substance that modifies different combinations of two or more of these or indeed other properties of the aerosol flow. 
     It will be understood however that materials other than tobacco may be used to impart different flavors to the aerosol. 
     If the material  30  is or includes tobacco, it may be that the aerosol flow draws sufficient nicotine from the material  30 . Alternatively or additionally, if the material  30  does not contain any tobacco, the material  30  may be enhanced with nicotine, for example by coating the material with nicotine. Indeed, even in the case that the material  30  is or includes tobacco, the material  30  may be coated or otherwise enhanced with nicotine. As another example, whether or not the material  30  is or includes tobacco and/or includes nicotine, nicotine may be provided in the aerosol provision material, in this example liquid  20 . Accordingly, where it is intended that the system  100  provides nicotine for the user, the nicotine may be provided in the aerosol provision material  20 , may be obtained from the material  30  in the case that the material is or includes tobacco, may be provided as a coating or the like on the material  30  if it is non-tobacco material, may be provided as a coating or the like on the material  30  if it is tobacco material, or any combination of these. Likewise, flavorings may be added to the material  30  (whether or not the substance is or includes tobacco) and/or to the aerosol provision material. 
     In at least some examples a vapor is produced that then at least partly condenses to form an aerosol before exiting the aerosol provision device  100  through the material chamber  430  for inhalation by a user (not shown). 
     In this respect, first it may be noted that, in general, a vapor is a substance in the gas phase at a temperature lower than its critical temperature, which means that for example the vapor can be condensed to a liquid by increasing its pressure without reducing the temperature. On the other hand, in general, an aerosol is a colloid of fine solid particles or liquid droplets, in air or another gas. A “colloid” is a substance in which microscopically dispersed insoluble particles are suspended throughout another substance. 
     For reasons of convenience, as used herein the term aerosol should be taken as meaning an aerosol, a vapor or a combination of an aerosol and vapor. 
     Returning to  FIG. 1 , the device  100  of this example comprises a cartridge  200 , a body portion  300 , and a mouthpiece assembly  600 . The mouthpiece assembly  600  comprises a first housing  500 , which is a mouthpiece for being received in the mouth of a user, and a second housing  400  which is for containing a material  30 . The first housing  500  will be referred to herein as a mouthpiece, while the second housing  400  will be referred to as a container. 
     The cartridge  200  is for containing aerosol provision material  20 , which in this case, as mentioned above, is e-liquid, while the body portion  300  is for powering and controlling the device  100 . 
     The cartridge  200  comprises a third “upper” housing  210  and the body portion  300  comprises a fourth “lower” housing  310 . The upper housing  210  is releasably attached to the lower housing  310  through a first connector arrangement  270 . The first connector arrangement  270  is discussed in more detail below. 
     The cartridge  200  comprises a liquid reservoir  220  for containing the e-liquid. The material container  400  comprises a chamber  430  for receiving a material  30 . The material may comprise tobacco, or may not comprise tobacco. 
     In the example of  FIG. 1 , the cartridge  200  also contains a heating arrangement  240 . The heating arrangement is for heating e-cigarette liquid  20  from the liquid reservoir  220  to generate a flow of aerosol (not shown). 
     The heating arrangement  240  may comprise at least one heating element (not shown). While the liquid reservoir  220  is shown above the heating arrangement  240  in  FIG. 1 , the liquid reservoir  220  may comprise an annular chamber (not shown) surrounding a central aperture (not shown) through which generated aerosol flows. The heating arrangement  240  may then comprise at least one wick (not shown) for supplying liquid  20  from the liquid reservoir  220  to the at least one heating element. 
     The heating arrangement  240  may be referred to as an “atomizer”, and where the liquid cartridge  200  comprises an atomizer, the cartridge may be referred to as a “cartomizer.” Alternatively to comprising a heating arrangement  240 , the device may aerosolize liquid via non-heating means, such as via an ultrasonic atomizer. 
     The material  30 , such as tobacco, can be heated by heat transfer from the aerosol flow to the material. In use, and particularly in the case that the material is tobacco, the tobacco, or at least the surface of the tobacco, can be heated to a temperature of between around 120° C. to 170° C., for example around 150° C., so as to ensure that an adequate or appropriate amount of the compounds are released from the tobacco. The amount of tobacco present may be for example in the range 100 to 400 mg or so. A most suitable value for the amount of tobacco may be for example in the range 150 to 380 mg which may found to be particularly suitable in some applications such as when the tobacco used in pH treated tobacco. In another example, a most suitable value for the amount of tobacco may be for example in the range 120 to 190 mg which may be found to be particularly suitable when ground tobacco is used. In a typical example, the amount of tobacco that is heated per operation of the system (i.e. per puff) may be in the corresponding range of around 8 to 50 mg. 
     The liquid  20  can be a liquid that is volatilizable at reasonable temperatures, such as in the range of 100−300° C. or more particularly around 150-250° C., as that helps to keep down the power consumption of the system  100 . Suitable materials include those conventionally used in e-cigarette devices, including for example propylene glycol and glycerol (also known as glycerine). 
     The lower housing  310  contains a power source  320 , typically a battery, which is electrically connected to various components of the device  100 , including the heating arrangement  240 . 
     The battery  320  may be a rechargeable battery or a disposable battery. A controller  330 , which may comprise a micro-chip and associated circuitry is also provided in the second housing  310  for controlling the operation of various components of the device  100 . A user input means  340 , for example one or more control buttons, may be provided on the exterior of the second housing  310  for a user to operate the controller  330 . 
     Accordingly, in use, a user draws on the mouthpiece  500 , and air is drawn through one or more air inlets  111 . The heater arrangement  240  is powered by the user operating the control button  340  (or alternatively by a puff detector (not shown), as is known per se) and liquid  20  drawn from the liquid reservoir  220  is heated by the heater arrangement  240  to volatilize the liquid  20  to generate aerosol which mixes with air flowing from the air inlet  111  to produce a flow of aerosol. The flow of aerosol is drawn through the material  30  in the chamber  430  and then out of the device  100  through an aperture  590  in the mouthpiece  500  for inhalation by the user. As the aerosol flow passes through the material  30 , one or more components of the material  30  become entrained in the aerosol flow which may alter, or add to, a property of the aerosol, such as its taste. 
     The upper housing  210  has a distal end, or base end,  260  and a proximal end, or mouth end,  250 . As mentioned above, the cartridge  200  comprises the liquid reservoir  220  which may take various different forms. In one example, the liquid reservoir  220  is in the form of an annular chamber which extends axially in the first housing  210  between the proximal end  250  and the base end  260 . The distal end  260  of the cartridge  200  comprises a first connector arrangement  270  for releasably attaching the cartridge housing  210  to the body portion housing  310 . At a proximal end, or mouth end,  250  of the cartridge  200 , the cartridge comprises a second connector arrangement  280  which releasably connects the cartridge  200  to the material container  400  by releasably connecting the cartridge housing  210  to a material container housing  410 . The first connector arrangement  270  and second connector arrangement  280  will be discussed in more detail below. 
     In some examples, it may be that the user only needs to top up or replace the material  30  from time to time, with sufficient liquid  20  being provided for several uses. In the example of  FIG. 1 , the cartridge  200  is releasably attached to the body portion  300 , and once the liquid  20  has been consumed, the user disposes of the cartridge  200  and provides a new cartridge. In other examples, the cartridge  200  is not designed to be disposable and instead the user only needs to top up or replace the liquid  20  from time to time. In other examples, the cartridge  200  and the device body portion  300  are integrated in a single device and are not arranged to be detachable from each other. In such examples, the device may comprise a replaceable atomizer or replaceable heating means for producing aerosol from the aerosolizable substance. 
     The mouthpiece  500  in the example of  FIG. 1  is shown connected to the material container  400  by a first attachment  580  to form a mouthpiece assembly  600 . The first attachment  580  may be a releasable attachment, or alternatively, the mouthpiece  500  and the container  400  may be attached non-releasably, for example by ultrasonic welding or by an adhesive. Examples of the mouthpiece assembly will be discussed below with reference to  FIGS. 4 a  and 4 b   ,  FIGS. 6 a  and 6 b    and  FIG. 7 . 
     Referring now to  FIG. 2 , a perspective view of the example aerosol provision device  100  of  FIG. 1  is shown. The aerosol provision device comprises the body portion  300 , the e-liquid cartridge  200 , and the mouthpiece assembly  600  comprising a material container  400 . In this example, the material container  400  is contains tobacco, but a non-tobacco material, such as any of the materials listed above, may additionally or alternatively be contained within the chamber  430  of the container  400 . 
     First Connector Arrangement 
     The cartridge  200  in this example comprises a first connector arrangement  270  for releasably attaching the cartridge  200  to the body portion  300 . The first connector arrangement  270  may be configured in a locked state, wherein it is not possible for a user to detach the cartridge  200  from the device body  100 , or the first connector arrangement may be configured in an unlocked state, wherein a user can detach the cartridge  200  from the device body by pulling the cartridge  200  and body portion  300  apart. When the first connector arrangement  270  is configured in the locked state the cartridge and body portion may not be separated by pulling. The first connector arrangement  270  can be configured in the unlocked configuration while the cartridge remains stationary with respect to the body portion. That is, the cartridge does not have to be rotated or otherwise moved to unlock the first connector arrangement  270 . 
     For example, the first connector arrangement  270  may comprise a first element  207  on the cartridge  200  which interacts with a corresponding second element (not shown) on the body portion  300  when the first connector arrangement is in the locked configuration. The first connector arrangement  270  can be released by moving the first element  207  with respect to the second element while the cartridge  200  remains stationary with respect to the body portion  300 . Here, it may be the first element  207  which is moved while the second element (not shown) remains stationary with respect to the body portion  300 , it may be the second element which is moved while the first element remains stationary, or both the first and second elements may be moved with respect to the body portion. 
     In the example of  FIG. 2 ,  FIG. 3  and  FIG. 5 , the first connector arrangement  270  is a clip. To remove the cartridge  200  from the body portion  300  the clip  270  is configured in the unlocked configuration by moving the first element, a tab  207 , with respect to a second element, a detent (not shown) on the body portion while the cartridge  200  remains stationary with respect to the body portion  300 . The cartridge  200  can then be pulled free of the body portion  300 . 
     The first connector arrangement  270  can thus be rapidly configured from being in the locked configuration to being in the unlocked configuration without having to rotate or otherwise move the cartridge with respect to the device body, such as would be the case where a cartridge is screw-fit to a device body. Additionally, in the examples of  FIGS. 2 and 3 , the first connector arrangement  270  automatically enters the locked configuration when the cartridge  200  is pushed together with the device body  300  with their longitudinal axes suitably aligned. That is, the clip  207  automatically snaps into the locked configuration, providing for the cartridge and device body to be rapidly attached, again not requiring screwing together of any components. 
     The example first connector arrangement  270  of  FIG. 2 ,  FIG. 3  and  FIG. 5  has one tab, a first tab  207 , which interfaces with a respective detent (not shown) in the body portion  300 . In other examples, the first connector arrangement  270  may comprise a plurality of tabs and may comprise two, three, four, five or more tabs situated at any point around the circumference of the distal end  260  of the cartridge. In another advantageous example, the clip  270  has two tabs which are advantageously situated on opposite sides of the distal end  260  of the cartridge  200 . Each tab  207  may be flexible and may be formed of a flexible plastics material. 
     The cartridge  200  in the example of  FIG. 2  is shaped with a proximal end  250  having a smaller cross-sectional area than a distal end  260 . 
     When the cartridge  200  and body portion  300  are attached with the clip  270  in the locked configuration, the cartridge  200  makes the necessary electrical connections with the body portion such that power is supplied to the cartridge  200 . The device  100  is shown in  FIG. 2  with the clip  270  in this locked configuration. 
     In order to release the cartridge  200  from the body portion  300  the first connector arrangement  270  must be configured in an unlocked state. In the example of  FIG. 2  and  FIG. 3 , to configure the first connector arrangement in an unlocked state the user presses the first tab  207  radially inwards, towards the longitudinal axis of the device  100 . 
     Now with reference to  FIG. 3  (the first connector arrangement of  FIG. 5  also comprises the same features now to be described), an example first tab  207  is shown comprising a hooked portion  208  at the distal end of the first tab  207 . The first tab  207  is flexible and is biased to the position in which it is shown. The hooked portion  208  becomes hooked in a detent (not shown) in the body portion  300  when in the locked configuration, preventing the cartridge  200  being pulled free of the body portion  300 . When a user presses radially inwards on the first tab  207  the tab flexes radially inwards and frees the hooked portion  208  from the detent in the body portion  300 . The clip  270  thereby enters an unlocked configuration. The user may then detach the cartridge  200  from the body portion  300  by pulling the cartridge and the body portion apart while keeping tab  207  depressed (and thus keeping the first connector arrangement  270  in the unlocked configuration). 
     In other examples comprising more than one tab  207 , each tab may interacts with a respective detent and may be released in the same way as described for the first tab  207  such that a user must keep all tabs depressed to configure the first connector arrangement  270  in the unlocked state. 
     In other examples not shown, the first connector arrangement may comprise a release button which a user presses to configure the first connector arrangement in the unlocked configuration. 
     Providing a first connector arrangement which is in a locked state by default but which may be unlocked by pressing and detached by pulling, such as in the example of  FIG. 2 , provides a secure attachment while allowing for a user to quickly and easily detach a cartridge  200  from the device body  300 . 
     Second Connector Arrangement 
     The cartridge  200  also comprises a second connector arrangement  280 , through which the mouthpiece assembly  600 , comprising material container  400 , may be attached to the cartridge  200 . The second connector arrangement  280  is advantageously an arrangement that allows the mouthpiece assembly  600  to be push-fit to the cartridge  200 . 
     That is, advantageously, as in the examples shown in  FIGS. 2 to 7 , the second connector arrangement  280  is a push-fit attachment which allows the user to separate the mouthpiece assembly  600  from the cartridge  200  by pulling the two apart. This provides for quick and easy detachment of the mouthpiece assembly  600  from the device  100 , for example when the user wishes to replace the material container. 
     In  FIG. 2 ,  FIG. 3 , and  FIG. 5 , examples of the second connector arrangement  280  are shown, comprising a recess  290  at the proximal end  250  of the cartridge  200  for accommodating a portion of the mouthpiece assembly  600 . To attach to a mouthpiece assembly  600 , the container  400  is inserted into the recess  290  and a portion of the container  400  is held in the recess  290  by friction or snap-fitting. 
     In advantageous examples the material container  400  comprises at least one first surface formation  208   b ,  208   c , on its outer surface which interacts via friction with a corresponding at least one second surface formation  208   a ,  208   d  on an inner surface of the recess  290 . 
     The at least one first surface formation  208   b ,  208   c  on the surface of the container  400  interacts with the at least one second surface formation  208   a ,  208   d  on the inner surface of the recess  290  to form a substantially airtight seal around the container  400  when the container  400  is connected to the cartridge  200  via the second connector arrangement  280 . In this way, the second connector arrangement  280  substantially prevents leakage of aerosol or loss of pressure from the device. 
     Each of the at least one first surface formation  208   b ,  208   c  may comprise at least one formation, such as a rib, protruding radially outwards from the surface of the container  400 , and/or may comprise at least one depression, such as a groove, in the surface of the container  400 . Similarly, the at least one second formation  208   a ,  208   d  on the inner surface of the recess  290  may comprise at least one formation protruding radially from the inner surface of the recess  290  and/or at least one depression in the inner surface of the recess  290 . 
     In advantageous examples, interaction between the at least one first surface formation  208   b ,  208   c  and the at least one second surface formation  208   a ,  208   d  provides for the second releasable attachment  280  to provide for snap-fitting of the container  400  to the cartridge  200 . In some examples (not shown), one of the at least one first surface formations may be a surface formation which is biased and which at least partially retracts when the container  400  is in the process of being connected to the cartridge  200  and snaps into interaction with a corresponding second surface formation, providing a substantially airtight seal, when the container  400  is inserted into the recess  290 . 
     In other examples, such as the examples shown in  FIG. 3  and  FIG. 5 , the tolerances of the dimensions of the container  400 ; the recess  290 ; and their respective surface formations; may be such that the surface formations need not be biased and the container  400  is held in place, and a substantially airtight seal made, by interactions between fixed surface formations (first surface formations  208   b ,  208   c  and second surface formations  208 ). 
     In the example of  FIG. 3  and  FIGS. 4 a  and 4 b   , the first surface formations on the surface of the container  400  comprise at least one groove  208   b  while the at least one second surface formation  208   a  of the recess  290  comprises at least one circumferential ridge  208   a  for interacting with the at least one groove  208   b  on the surface of the container  400 . In this example, the groove  208   b  can have a width of between about 0.15 mm and about 0.17 mm. In the example of  FIG. 4 a    and  FIG. 4 b   , the surface of the container  400  comprises a longitudinal formation  208   c , which may be a ridge or a groove, for interacting with a corresponding longitudinal formation ( 208   d ,  FIG. 2 ) on the inner surface of the recess  290 . 
     In contrast, in the example of  FIG. 5 ,  FIG. 6 a    and  FIG. 6 b   , and  FIG. 7 , the first surface formations on the surface of the container  400  comprise at least one ridge  208   b ,  208   c , for interacting with at least one groove  208   a ,  208   d  in the inner surface of the recess  290 . The surface formations  208   a ,  208   b ,  208   c  in the example of  FIGS. 5 to 7  will be discussed below in more detail. 
     As best seen in  FIG. 2 , when the first connector arrangement  270  of the cartridge  200  is configured in a locked state, wherein the cartridge cannot be separated from the body portion  300  by pulling unless a user presses the tab  207 , inadvertent detaching of the cartridge from the device body can be avoided. That is, a user can easily separate the mouthpiece assembly  600  from the cartridge  200  by pulling, without separating the cartridge from the device body  300 . With a device  100  such as in this example, the material  30  is often changed more frequently that the liquid  20 ; this arrangement makes replacement of the material  30  easier and more efficient. 
     Mouthpiece Assembly 
     An example of the mouthpiece assembly  600  will now be described in more detail with reference to  FIG. 6 a   ,  FIG. 500  detached from the second, material container, housing  400  to provide a view of the proximal end  407  of the container  400 . 
     The mouthpiece assembly  600  comprises a material container  400  and mouthpiece  500 . As mentioned above, the container  400  comprises at least one first surface formation  208   b ,  208   c , in this case a set of first ridges or ribs  208   b ,  208   c  on its outer surface for interacting via friction with the cartridge  200  into which the container  400  is fit in use. 
     In the example of  FIG. 6 a   ,  FIG. 6 b    and  FIG. 7 , first ridges  208   b  extend circumferentially around an outer surface of the container  400 . The first ridges  208   b ,  208   c , in this example also comprise one or more circumferential ridges  208   b . Advantageously the container comprises two or more circumferential ridges  208   b  or three or more circumferential ridges  208   b . In this example, as seen best in  FIG. 6 b   , there are three circumferential ridges  208   b , with one central circumferential ridge and two peripheral circumferential ridges. In this example, the central circumferential ridge extends further radially from the surface of the container  400  than the peripheral circumferential ridges extend radially from the surface of the container and the width of the central circumferential ridge can be between about 0.15 mm and about 0.17 mm. 
     In this example, the second surface formation  208   a ,  208   d  on the inner surface of recess  290  of the cartridge  200  may comprise at least one circumferential groove ( 208   a    FIG. 5 ) with which the first ridges  208   b ,  208   c  interact. Continuing with the example of  FIG. 6 a   ,  FIG. 6 b    and  FIG. 7 , at least one of the first surface formations may be a rib  208   b  of flexible and/or compressible material, such as a rubber or a plastics material, for example silicone, which may compress to allow the material container  400  to be fitted into the recess  290  and expand to interact with a corresponding groove  208   a  in the surface of recess  290 , thus holding the container  400  in place and contributing to forming a substantially airtight seal. 
     The set of first ridges of the example container  400  shown in  FIG. 6 a   ,  FIG. 6 b    and  FIG. 7  also comprises at least one longitudinal ridge  208   c  which extends along the surface of the container  400 . In  FIGS. 4 a , 4 b   , it can be seen that the container  400  in this example comprises a plurality of longitudinal ridges  208   c . The longitudinal ridges  208   c  may interact with the inner surface of the recess  290  and may interact with at least one corresponding longitudinal groove ( 208   d ,  FIG. 2 ) on the inner surface of the recess  290 . The longitudinal ridges  208   c  on the container  400  may assist with providing a substantially airtight seal and may additionally assist with achieving correct alignment between the container  400  and the cartridge  200  when the container  400  is being inserted into the recess  290 . In other examples (not shown), the recess  290  may comprise a longitudinal ridge while the container  400  comprises a longitudinal groove. 
     The container  400  may comprise any number of ridges or grooves extending in any direction along its surface. In other examples, the container  400  may not comprise any surface formations and may be push-fit to the cartridge  200  purely by friction between the surfaces of the container and the recess  290  in the cartridge  200 . The surface of the container  400  may comprise a material with a high coefficient of friction, such as a plastics or rubber material, to assist with friction-fitting. The container  400  may comprise a plastics material, such as polypropylene. 
     With reference to  FIG. 7 , the container  400  is shown to comprise a chamber  430  containing material  30 . During manufacture, the container  400  is formed comprising a chamber  430  and a material  30  is then provided in the chamber. The material  30  is enclosed in the chamber by a first barrier  404  enclosing the chamber  430  near the proximal end  450  and a second barrier  405  enclosing the chamber  430  near the distal end  460 . 
     The first barrier  404  and second barrier  405  comprise a mesh which is porous to the flow of aerosol and which prevents material  30 , such as tobacco material, from exiting the chamber  430 . The mesh is formed of a heat-resistant material, and is advantageously a heat-conductive material, such as a metal, since this aids in transferring heat to the material  30  in order to release more desired compounds from the material. The mesh being porous, allows aerosol to pass into the chamber  430  from the cartridge  200  at a distal end  460  and allows aerosol to pass out at a proximal end  450  into the inhalation aperture  590  for inhalation by a user. At the proximal end  250 , the mesh prevents the material  30  from passing into the mouthpiece  500  and being inadvertently inhaled by a user. 
     In the case that the first barrier  404  and the second barrier  405  are both a mesh, the mesh may comprise a plastics material, such as polypropylene, or a metal, such as stainless steel or aluminum, and may comprise, for example, an aluminum foil. In some embodiments, the mesh is a stainless steel mesh. The mesh may have a thickness of between about 0.1 mm and about 1.2 mm and, for example, may have a thickness of around 1.2 mm when mesh comprises a plastics material; or a thickness of about 0.1 mm to about 0.3 mm when the mesh comprises a metal such as stainless steel; or a thickness of about 0.3 mm when the mesh comprises aluminum foil. The mesh is advantageously a mesh with a maximum aperture size which is advantageously smaller than the diameter of the material  30  to be contained. For example, where the material  30  is tobacco, the maximum mesh aperture size may be between about 0.2 mm and about 0.7 mm, and the maximum mesh aperture size may be chosen dependent on the type of tobacco used. 
     During construction, the first, mouthpiece housing  500  and the second, container, housing  400  are formed separately. The container  400  and the mouthpiece  500  are then attached to form the mouthpiece assembly  600 . 
     The mouthpiece  500  may be formed, for example, from a plastics material, such as polypropylene, by injection molding. The shape of the mouthpiece  500  in the example of  FIG. 7  is such that it is flared towards its distal end  508 . This provides an ergonomic shape for a user&#39;s mouth to contact. In this example, at its distal end  508  the mouthpiece  500  has a diameter larger than the diameter of the proximal end of the cartridge  200 . The mouthpiece  500  is formed such that it is configured to accommodate the material pod housing  409 . The mouthpiece has an aperture  590  at its proximal end which may in some examples, such as that of  FIG. 4 b   , comprise longitudinal fins  591  for channeling the flow of aerosol along the aperture  590 . 
     The container  400  may also be formed from a plastics material by injection molding. The container  400  may for example be formed of polypropylene or of polyethylene terephthalate (PET). In this example, the proximal end  407  of the container comprises a step formation corresponding to a complementary shape of the interior surface  507  of the mouthpiece housing  500 . 
     The container  400  further comprises a protrusion  406  which extends circumferentially around the surface of the container. This protrusion  406  is configured to abut with a distal end  508  of the mouthpiece housing  500  and further to provide a substantially airtight seal between the mouthpiece assembly  600  and the cartridge  200  when the two are fitted together via the second connector arrangement  280 . The protrusion  406  may, in some examples such as the example of  FIGS. 6 a  and 6 b   , comprise a plurality of substantially triangular prism portions  406   a  and a plurality of substantially flat portions  406   b  wherein a substantially flat portion  406   b  is located between each triangular prism portion  406   a  and the triangular prism portions  406   a  protrude a greater distance radially outwards than the flat portions  406   b  protrude radially outwards. The protrusion  406  in the example of  FIGS. 6 a  and 6 b    also comprises at least one trapezoidal prism portion  406   c , which is located adjacent a triangular prism portion  406   a  and is located further towards a proximal end  450  of the container  400 . The planes of the non-parallel faces of the trapezoidal prism portion  406   c  are aligned along the longitudinal axis of the container  400 . In attaching the mouthpiece  500  to the material pod  400 , a portion of the container housing  400  is inserted into a recess at the distal end of the mouthpiece housing  500 . When the container is inserted in this recess, the step formation at the proximal end  407  of the container  400  abuts against the interior surface  507  of the mouthpiece, and the distal end  508  of the mouthpiece  500  abuts against the protrusion  406 . 
     Advantageously, the container housing  400  and mouthpiece housing  500  are attached via ultrasonic welding. The protrusion  406  then may provide the point of contact for an ultrasonic welding apparatus to attach the container  400  to the mouthpiece  500 . 
     Alternatively, an adhesive at the points of contact (for example 407 and 507, and 406 and 508) may be used to attach the mouthpiece  500  to the material pod  400 . In yet other alternatives, the mouthpiece  500  and container  400  may be releasably attached, for example via friction-fit or a snap-fit, in which case no adhesive is used. 
     In some examples the first mesh  404 , and second mesh  405  is fitted to both the proximal end  450  and distal end  460  of the container  400  after the container  400  is formed and after the material  30  is provided in the chamber  430 . In other examples, the first mesh  404  at either the proximal end  450  or the second mesh  405  at the distal end  460  of the container  400 , advantageously the first mesh  404  at the proximal end  450 , is formed integrally with the container  400 . For example the first mesh  404  at the proximal end  450  may be formed during a process of molding the container  400  and material  30  may then be provided in the container before being enclosed by a second mesh  405  at the distal end  460 . In advantageous examples where the mouthpiece  500  and container  400  are joined by ultrasonic welding, the first mesh  404  is advantageously fitted to the proximal end  250  of the container  400  during the ultrasonic welding process. 
     Providing the container  400  and the mouthpiece  500  as a single mouthpiece assembly  600  provides ergonomic benefits to a user. For example, the user may grip and pull the mouthpiece  500  in order to remove the assembly  600  when the material  30  needs replacing. The user can then replace the assembly  600  as a whole, avoiding the time-consuming task of removing and replacing a material container which is separate from a mouthpiece. The assembly also ensures that a new mouthpiece is fitted with the same frequency that the material  30  needs replacing. This provides a hygiene benefit over mouthpieces in other devices which are used for more prolonged periods of time. 
     The mouthpiece assembly  600  also has benefits over hybrid devices which have a container which acts as a mouthpiece but which have no separate mouthpiece. Among other advantages, the mouthpiece assembly  600  provides an ergonomically shaped mouthpiece  500  and the flared shape reduces contact of the user&#39;s mouth with other parts of the device, thereby improving hygiene. Further, the inclusion of the mouthpiece  500  in addition to a material container  400  (as opposed to the container  400  acting as a contact point for a user&#39;s mouth) provides a spatial separation of the material pod from the user&#39;s mouth, preventing contact of the user with potentially hot material and reducing the likelihood that any of said material is inadvertently inhaled. The mouthpiece aperture  590  provides a space between the proximal end  450  of the container  400  and the proximal end of the mouthpiece aperture  590 —this space may provide an improvement to the quality of aerosol flow delivered to a user. For example, the provision of this space may provide an improvement in any one of or any combination of the following properties of the aerosol flow delivered to a user: particle size in the aerosol; the degree of condensation of the aerosol from the aerosol flow; and the temperature of the aerosol flow. 
     As discussed above, the method of manufacturing the mouthpiece assembly  600  comprises: providing the container  400 ; providing a material  30  in the container; enclosing the material in the container with a first barrier; providing the mouthpiece  500 ; and attaching the container  400  to the mouthpiece  500 . This is a cost-effective process resulting in an ergonomic and convenient product. 
     It should be noted that a number of other variations and alternatives to the examples described above are possible. 
     As an example, the material may be omitted from the material chamber, for example at the option of the user. This provides the user with more flexibility over the use of the cartridge as the user can use the cartridge as a classic “e-cigarette” device, only aerosolizing liquid and not having the aerosol pass over or through material, from time to time if they choose. 
     As used herein, the terms “flavor” and “flavorant” refer to materials which, where local regulations permit, may be used to create a desired taste or aroma in a product for adult consumers. They may include extracts (e.g., licorice, hydrangea, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, menthol, Japanese mint, aniseed, cinnamon, herb, wintergreen, cherry, berry, peach, apple, Drambuie™, bourbon, scotch, whiskey, spearmint, peppermint, lavender, cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, honey essence, rose oil, vanilla, lemon oil, orange oil, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, piment, ginger, anise, coriander, coffee, or a mint oil from any species of the genus Mentha), flavor enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and/or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example, oil, liquid, or powder. 
     In order to address various issues and advance the art, the entirety of this disclosure shows by way of illustration and example various embodiments in which the claimed invention may be practiced and which provide for a superior system arranged to generate an inhalable medium. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are presented only to assist in understanding and teach the claimed and otherwise disclosed features. It is to be understood that advantages, embodiments, examples, functions, features, structures and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilized and modifications may be made without departing from the scope and/or spirit of the disclosure. Various embodiments may suitably comprise, consist of, or consist in essence of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. The disclosure may include other inventions not presently claimed, but which may be claimed in future.