Patent Publication Number: US-2022232894-A1

Title: Inductor coil for an aerosol provision device

Description:
TECHNICAL FIELD 
     The present invention relates to a method of forming an inductor coil for an aerosol provision device, a support member, an aerosol provision device inductor coil manufacturing system, an inductor coil, and a system. 
     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. 
     SUMMARY 
     According to a first aspect of the present disclosure, there is provided a method of forming an inductor coil for an aerosol provision device, the method comprising: 
     providing a multi-strand wire comprising a plurality of wire strands, wherein at least one of the plurality of wire strands comprises a bondable coating; 
     winding the multi-strand wire around a support member such that the multi-strand wire is received in a channel formed in an outer surface of the support member; 
     activating the bondable coating such that the multi-strand wire substantially retains a shape determined by the channel; and 
     removing the multi-strand wire from the support member. 
     According to a second aspect of the present disclosure, there is provided a support member for forming an inductor coil of an aerosol provision device, the support member defining an axis about which a multi-strand wire of the inductor coil is windable, wherein an outer surface of the support member comprises a channel to receive the multi-strand wire. 
     According to a third aspect of the present disclosure, there is provided an aerosol provision device inductor coil manufacturing system, comprising: 
     a support member according to the second aspect; and 
     a drive assembly configured to rotate the support member about an axis of the support member, such that, in use, the multi-strand wire is wound on to the support member. 
     According to a fourth aspect of the present disclosure, there is provided an inductor coil for an aerosol provision device, the inductor coil formed according to a method comprising the method of the first aspect. 
     According to a fifth aspect of the present disclosure, there is provided an inductor coil for an aerosol provision device, wherein the inductor coil defines an axis and comprises a multi-strand wire that is wound around the axis, and wherein the multi-strand wire has a cross section with a greatest lateral dimension that is greater than a greatest longitudinal dimension, wherein the greatest lateral dimension is measured in a direction perpendicular to the axis, and the greatest longitudinal dimension is measured in a direction perpendicular to the greatest lateral dimension. 
     According to a sixth aspect of the present disclosure, there is provided an aerosol provision device comprising: 
     a receptacle for receiving at least part of an article comprising aerosolisable material; and 
     a heating assembly for heating the article when the article is arranged in the receptacle, wherein the heating assembly comprises: 
     at least one of the inductor coils of any of the fourth and fifth and tenth aspects for generating a varying magnetic field for penetrating a susceptor to thereby cause heating of the susceptor. 
     According to a seventh aspect of the present disclosure, there is provided a support member for use in forming an inductor coil of an aerosol provision device, the support member defining an axis about which a wire of the inductor coil is windable, wherein the support member is moveable between a first configuration, in which the wire is windable around the support member, and a second configuration, in which a cross sectional width of the support member perpendicular to the axis is smaller than when the support member is in the first configuration thereby to facilitate removal of the wire from the support member. 
     According to an eighth aspect of the present disclosure, there is provided a system comprising: 
     a support member according to the seventh aspect; and 
     a device configured to cause movement of the support member between the first and second configurations. 
     According to a ninth aspect of the present disclosure, there is provided a method of forming an inductor coil for an aerosol provision device, the method comprising: 
     providing a multi-strand wire comprising a plurality of wire strands, wherein at least one of the plurality of wire strands comprises a bondable coating; 
     winding the multi-strand wire around a support member defining an axis; 
     activating the bondable coating such that the multi-strand wire substantially retains a shape determined by the support member; 
     reducing a cross-sectional width of the support member in a direction perpendicular to the axis; and 
     removing the multi-strand wire from the support member. 
     According to a tenth aspect, there is provided an inductor coil for an aerosol provision device, the inductor coil formed according to a method comprising the method of the ninth aspect. 
     Further features and advantages of the invention will become apparent from the following description of preferred embodiments of the invention, given by way of example only, which is made with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a front view of an example of an aerosol provision device; 
         FIG. 2  shows a front view of the aerosol provision device of  FIG. 1  with an outer cover removed; 
         FIG. 3  shows a cross-sectional view of the aerosol provision device of  FIG. 1 ; 
         FIG. 4  shows an exploded view of the aerosol provision device of  FIG. 2 ; 
         FIG. 5A  shows a cross-sectional view of a heating assembly within an aerosol provision device; 
         FIG. 5B  shows a close-up view of a portion of the heating assembly of  FIG. 5A ; 
         FIG. 6  shows a perspective view of first and second inductor coils wrapped around an insulating member; 
         FIG. 7  shows a flow diagram of an example method of forming an inductor coil; 
         FIG. 8  shows a perspective view of manufacturing equipment used to form an inductor coil; and 
         FIGS. 9A and 9B  show perspective views of an inductor coil being formed; and 
         FIG. 10A  is a diagrammatic representation of a support member according to a first example; 
         FIGS. 10B and 10C  are close-up views of a portion of the support member of  FIG. 10A ; 
         FIG. 11  is a diagrammatic representation of a support member according to a second example; 
         FIG. 12  is a diagrammatic representation of a support member according to a third example; 
         FIG. 13  is a diagrammatic representation of a support member according to a fourth example; 
         FIG. 14  is a diagrammatic representation of a support member according to a fifth example; 
         FIG. 15  is a diagrammatic representation of a support member according to a sixth example; 
         FIG. 16A  is a diagrammatic representation of a support member according to a seventh example, where the support member is arranged in a first configuration; 
         FIG. 16B  depicts the support member of  FIG. 16A  surrounded by a wire; 
         FIG. 16C  is a cross-sectional view of the support member of  FIG. 16A ; 
         FIG. 16D  is a cross-sectional view of the support member of  FIG. 16B ; 
         FIG. 17A  depicts the support member of  FIG. 16A  arranged in a second configuration; 
         FIG. 17B  depicts the support member of  FIG. 17A  surrounded by a wire; 
         FIG. 17C  is a cross-sectional view of the support member of  FIG. 17A ; 
         FIG. 17D  is a cross-sectional view of the support member of  FIG. 17B ; 
         FIG. 18A  is an end view of the support member of  FIG. 16A ; 
         FIG. 18B  is an end view of the support member of  FIG. 17A ; 
         FIG. 19A  is a cross-sectional block diagram of a device inserted into a hollow cavity of an example support member; 
         FIG. 19B  is a cross-sectional block diagram of a device partially removed from a hollow cavity of an example support member; and 
         FIG. 20  shows a flow diagram of a second example method of forming an inductor coil. 
     
    
    
     DETAILED DESCRIPTION 
     As used herein, the term “aerosol generating material” includes materials that provide volatilised components upon heating, typically in the form of an aerosol. Aerosol generating material includes any tobacco-containing material and may, for example, include one or more of tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes. Aerosol generating material also may include other, non-tobacco, products, which, depending on the product, may or may not contain nicotine. Aerosol generating material may for example be in the form of a solid, a liquid, a gel, a wax or the like. Aerosol generating material may for example also be a combination or a blend of materials. Aerosol generating material may also be known as “smokable material”. 
     Apparatus is known that heats aerosol generating material to volatilise at least one component of the aerosol generating material, typically to form an aerosol which can be inhaled, without burning or combusting the aerosol generating material. Such apparatus is sometimes described as an “aerosol generating device”, an “aerosol provision device”, a “heat-not-burn device”, a “tobacco heating product device” or a “tobacco heating device” or similar. Similarly, there are also so-called e-cigarette devices, which typically vaporise an aerosol generating material in the form of a liquid, which may or may not contain nicotine. The aerosol generating material may be in the form of or be provided as part of a rod, cartridge or cassette or the like which can be inserted into the apparatus. A heater for heating and volatilising the aerosol generating material may be provided as a “permanent” part of the apparatus. 
     An aerosol provision device can receive an article comprising aerosol generating material for heating. 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 provision 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. 
     A first aspect of the present disclosure defines a method of forming an inductor coil for use in an aerosol provision device. The method starts with a multi-strand wire, such as a litz wire. A multi-strand wire is a wire comprising a plurality of wire strands and is used to carry alternating current. Multi-strand wire may be used to reduce skin effect losses in a conductor and comprises a plurality of individually insulated wires which are twisted or woven together. The result of this winding is to equalize the proportion of the overall length over which each strand is at the outside of the conductor. This has the effect of distributing alternating current equally among the wire strands, reducing the resistance in the wire. In some examples the multi-strand wire comprises several bundles of wire strands, where the wire strands in each bundle are twisted together. The bundles of wires are twisted/woven together in a similar way. 
     After a multi-strand wire has been provided, the method comprises winding the multi-strand wire around a support member such that the multi-strand wire is received in a channel formed around an outer surface of the support member. The support member acts as a support for forming the inductor coil. The support member may be tubular or cylindrical, for example, and the multi-strand wire can be helically wound/wrapped around the support member. 
     In the present disclosure, the support member has a channel which extends around the outer surface of the support member. The channel receives the multi-strand wire as it is wound around the support member. The spacing between adjacent turns in the channel can set the spacing between the adjacent turns of the formed inductor coil. The inductor coil therefore takes on the shape provided by the channel. The channel allows the shape and dimensions of the inductor coil to be better controlled during manufacture. The channel can be used to retain the multi-strand wire in place relative to the support member while the inductor coil is being formed. 
     The channel may be helical in some examples. The helical channel may have a constant or varying pitch along the axis of the support member. The channel may be known as a recessed guide path or a groove. The support member may also be known as a forming jig or mandrel. 
     At least one of the plurality of wire strands comprises a bondable coating. A bondable coating is a coating which surrounds the wire strand, and which can be activated (such as via heating), so that the wire strand within the multi-strand wire bonds to one more neighbouring strands. The bondable coating allows the multi-strand wire to be formed into the shape of an inductor coil on the support member, and after the bondable coating is activated, the inductor coil will retain its shape. The bondable coating therefore “sets” the shape of the inductor coil. In some examples, the bondable coating is the electrically insulating layer which surrounds the conductive core. However, the bondable coating and the insulation may be separate layers, and the bondable coating surrounds the insulating layer. In an example, the conductive core of the multi-strand wire comprises copper. The bondable coating may comprise enamel. 
     While the multi-strand wire is arranged in the channel, the method may further comprise activating the bondable coating such that the multi-strand wire substantially retains a shape determined by the channel. The multi-strand wire (now in the shape of the inductor coil) can be removed from the support member without losing its shape. 
     The above method can be performed to form inductor coils for use in aerosol provision devices. In some examples, the device may comprise two or more inductor coils. Each inductor coil is arranged to generate a varying magnetic field, which penetrates a susceptor. As will be discussed in more detail herein, the susceptor is an electrically conducting object, which is heatable by penetration with a varying magnetic field. An article comprising aerosol generating material can be received within the susceptor, or be arranged near to, or in contact with the susceptor. Once heated, the susceptor transfers heat to the aerosol generating material, which releases aerosol. 
     Winding the multi-strand wire and activating the bondable coating may comprise changing a cross-sectional shape of at least part of the multi-strand wire. Thus, as the multi-strand wire is received in the channel, the cross-sectional shape of the multi-strand wire may change. Accordingly, the channel may not only set the dimensions of the coil (such as the spacing between individual turns), but may also provide a means to control or alter the cross-sectional shape of the multi-strand wire. 
     The channel may have a predetermined cross-sectional shape, and the changing the cross-sectional shape may comprise imparting the predetermined cross-sectional shape to the multi-strand wire. The use of a channel provides a simple and effective way of manufacturing the multi-strand wire with a particular cross-sectional shape. The dimensions of the channel can therefore act as a mould to shape the multi-strand wire as necessary. This is particularly useful because certain cross-sectional shapes can provide different heating effects. 
     The combined effect of introducing the multi-strand wire into the channel and activating the bondable coating can modify the cross-section of the multi-strand wire. 
     In some examples, the support member defines an axis, and wherein the winding comprises winding the multi-strand wire around the axis. In some examples, the support member is elongate and the axis is a longitudinal axis. Changing the cross-sectional shape of the multi-strand wire may comprise modifying a cross-section of the multi-strand wire such that the cross-section of the multi-strand wire has a greatest longitudinal dimension that is different to a greatest lateral dimension, wherein the greatest longitudinal dimension is measured in a direction parallel to the axis, and the greatest lateral dimension is measured in a direction perpendicular to the greatest longitudinal dimension. Accordingly, the support member and channel may be used to form an inductor coil in which the multi-strand wire has a non-circular or non-square cross-section. For example, the width of the multi-strand wire may be smaller or larger than the depth. As mentioned, this can provide a desired heating effect. 
     In a particular example, changing the cross-sectional shape may comprise modifying a cross-section of the multi-strand wire such that the cross-section of the multi-strand wire has a greatest longitudinal dimension that is greater than a greatest lateral dimension. The multi-strand wire therefore has a cross-section in which the longitudinal extension (in a direction parallel to a magnetic axis of the inductor coil) is greater than a lateral extension (in a direction perpendicular to the magnetic axis). The multi-strand wire may therefore have a flattened or rectangular cross section where the individual wires within the multi-strand wire extend along the axis to a greater extent than in a direction perpendicular to the axis. Other shapes may also have these dimensions. It has been found that such a cross-section reduces energy losses in the induction coil. 
     In an alternative example, changing the cross-sectional shape may comprise modifying a cross-section of the multi-strand wire such that the cross-section of the multi-strand wire has a greatest longitudinal dimension that is smaller than a greatest lateral dimension. The multi-strand wire may therefore have a flattened or rectangular cross section where the individual wires within the multi-strand wire extend along the axis to a lesser extent than in a direction perpendicular to the axis. Such a configuration may allow the inductor coil to have more turns along its length, or may allow the heating effect to be reduced where necessary. For example, it may be useful to lessen the heating effect in a particular area along a susceptor. 
     Reference to a greatest longitudinal dimension means the longest longitudinal extension of the cross-section that is measurable in the direction parallel to the (longitudinal) axis. The cross-section may have an irregular shape, such that the longitudinal extension of the cross-section may vary at different points in the wire. Similarly, reference to a greatest lateral dimension means the longest lateral extension of the cross-section that is measurable in the direction perpendicular to the (longitudinal) axis. Again, the cross-section may have an irregular shape, such that the lateral extension of the cross-section may vary at various points along the axis. In some examples, the greatest longitudinal dimension may be known as a greatest first dimension and the greatest lateral dimension may be known as the greatest second dimension. 
     Modifying the cross-sectional shape of the multi-strand wire may comprise compressing the multi-strand wire in a direction parallel to the axis so as to increase a density of the plurality of wire strands. For example, the channel may have a width dimension that reduces with distance towards a base of the channel, and the reduction in width may cause the individual wires in multi-strand wire to become more densely compacted in the longitudinal dimension. This compression reduces the longitudinal extension of the multi-strand wire, and may mean that the lateral extension of the multi-strand wire increases. 
     Activating the bondable coating may comprise heating the support member such that the bondable coating is heated. For example, after the multi-strand wire has been wound around the support member, the multi-strand wire can be heated to cause the bondable coating of the wire strands to self-bond such that the inductor coil undergoes thermosetting. By heating the support member, the heat can be uniformly conducted to the multi-strand wire. 
     The method may comprise simultaneously heating the support member and winding the multi-strand wire around the support member. The heating is therefore performed at the same time as the winding. Heating while winding the multi-strand wire onto the support member allows the manufacture time to be reduced. In other examples, heating may occur after or before the multi-strand wire has been wound around the support member. 
     Heating the support member may comprise heating the support member to a temperature of between about 150° C. and 350° C., such as about 150° C. and 250° C. or between about 180° C. and 200° C. The bondable coating may therefore be activated at temperatures within this range. 
     In another example, the bondable coating may be activated via a solvent. 
     Activating the bondable coating may further comprise cooling the multi-strand wire after heating the bondable coating. This can cause the bondable coating to cool, thus setting the shape of the inductor coil. Cooling the multi-strand wire may comprise passing air over the multi-strand wire. An air gun or fan, for example, can blow air over the multi-strand wire. Using an air gun or fan can speed up the cooling process. 
     In one example the wire strands are Thermobond STP18 wires, commercially available from Elektrisola Inc., New Hampshire. These wires have been found to provide a good suitability for use in an aerosol provision device. For example, these wires have a relatively high bonding temperature such that the heated susceptor in the device does not cause the bondable coating to re-soften. 
     The method may further comprise rotating the support member about an axis of the support member, thereby causing the winding of the multi-strand wire around the support member. Thus, the support member can be turned so that the multi-strand wire is pulled onto the support member. This rotation makes it easier to manufacture the inductor coil. For example, this avoids having to move the wire around a static support member. 
     The method may further comprise moving the support member in a direction parallel to the axis (while simultaneously rotating the support member). This allows the multi-strand wire to be received in the helical channel. In a particular example, an end portion of the multi-strand wire is anchored at, or near, the end of the support member so that the multi-strand wire does not unravel. 
     According to the second aspect, there is provided a support member for forming an inductor coil of an aerosol provision device. The support member defines an axis, such as a longitudinal axis, about which a multi-strand wire of the inductor coil is windable, An outer surface of the support member comprises a channel to receive the multi-strand wire. The channel may be a helical channel, for example. 
     In some examples, the channel has a greatest depth dimension measured in direction perpendicular to the axis and a greatest width dimension measured in a direction perpendicular to the greatest depth dimension, and the greatest depth dimension is different to the greatest width dimension. In some examples, the greatest depth dimension is greater than the greatest width dimension. The channel may therefore be therefore deeper than it is wide. Such a channel can securely hold the multi-strand wire in place as it is being wound on to the support member. A channel that is deeper than it is wide can help avoid the multi-strand wire from accidentally exiting the channel before its shape can be fixed by activating the bondable coating. In some examples, the ratio of the greatest depth dimension to the greatest width dimension is between about 1.1 and 2 (i.e. between about 1.1:1 and about 2:1). 
     In some examples, the greatest depth dimension is less than the greatest width dimension. The channel may therefore be therefore wider than it is deep. 
     The channel may comprise a tapered mouth portion leading to a wire receiving portion. The wire receiving section is configured to receive the multi-strand wire. The wire receiving portion may have a greatest depth measured in direction perpendicular to the axis and a greatest width measured in a direction perpendicular to the greatest depth, and the greatest depth is different to the greatest width. In some examples, the greatest depth is greater than the greatest width. This allows an inductor coil to be formed which has a greatest longitudinal extension/dimension that is smaller than a greatest lateral extension/dimension. 
     In an alternative example, the greatest width may be greater than the greatest depth. This allows an inductor coil to be formed which has a greatest longitudinal dimension that is greater than a greatest lateral dimension. 
     The wire receiving portion is the part of the channel which holds or abuts the multi-strand wire after it has been fully received in the channel. The wire receiving portion is therefore located towards the base/floor of the channel. In examples where the channel imparts a predetermined shape to the multi-strand wire, the wire receiving portion is the part of the channel which imparts the predetermined shape. The tapered mouth portion defines a guide for guiding the multi-strand wire into the wire receiving portion of the channel. For example, the tapered mouth portion has a width dimension (measured parallel to the axis of the support member) that is decreasing towards the base of the channel. The tapered mouth portion therefore allows the multi-strand wire to be better aligned and received in the channel. The tapered mouth portion is arranged further away from the axis than the wire receiving portion. The tapered mouth portion may be provided by a bevelled or chamfered edge. 
     Reference to a greatest width dimension or greatest width means the widest part of the channel that is measurable in the direction parallel to the (longitudinal) axis. The channel may have an irregular width, such that the width of the channel may vary at different points. Similarly, reference to a greatest depth dimension or greatest depth means the deepest part of the channel that is measurable in the direction perpendicular to the (longitudinal) axis. The channel may have an irregular depth, such that the depth of the channel may vary at different points. 
     In a particular example, a ratio of the greatest depth to the greatest width is between about 1.1 and 2 (i.e. between about 1.1:1 and about 2:1). It has been found that a ratio within this range allows the heating effect of the inductor coil to be controlled, while ensuring that the multi-strand wire within the inductor coil remains correctly orientated. Optionally, the ratio is between about 1.1 and about 1.5. The ratio may be between about 1.1 and about 1.2. 
     In one example, the greatest width is between about 1.2 mm and about 1.5 mm. In one example, the greatest depth is between about 1.6 mm and about 1.7 mm. It has been found that an inductor coil which is formed in a wire receiving portion having these dimensions is particularly suitable for heating in an aerosol provision device. 
     In some examples the channel is a helical channel. 
     A surface of the tapered mouth portion may have a first surface gradient, and a surface of the wire receiving portion adjacent the tapered mouth portion may have a second surface gradient that is greater than the first surface gradient. The first and second surface gradients are defined relative to the axis. Accordingly, the tapered mouth portion has a gradient that is shallower than the gradient of the wire receiving section arranged next to the tapered mouth portion. A shallower gradient provides a smooth transition into the channel without inadvertently altering the cross-sectional shape of the multi-strand wire before it is received in the wire receiving portion. In one example, the surface of the wire receiving portion arranged adjacent the tapered mouth portion is arranged substantially vertically (i.e. orientated perpendicular to the axis). This vertical arrangement can provide a means of containing and securing the multi-strand wire within the channel. 
     In a particular example, the floor of the channel is substantially flat or rounded. That is, the base of the channel is flat or rounded. A flat or rounded shape can allow the multi-strand wire to be easily removed from the channel. 
     The channel may have a width dimension that reduces with distance towards a floor/base of the channel. The channel is therefore tapered, and has inclined surfaces, which can allow the multi-strand wire to be more uniformly constricted/compressed as it is received in the channel. The base of the channel is the part of the channel which is positioned furthest away from the outer surface of the support member. 
     The support member may be heat resistant to a temperature of greater than 150° C. This allows the support member to be heated to temperatures of at least 150° C. so that the bondable coating of the multi-strand wire can be activated via heating. The support member may be made from metal, for example, which is a good conductor of heat and has a high melting point. For example, the support member may comprise steel, stainless steel or aluminium. The support member may have a melting point of greater than about 600° C., or greater than about 700° C., or greater than about 800° C., or greater than about 1000° C., or greater than about 1500° C., for example. 
     According to a third aspect, there is provided an aerosol provision device inductor coil manufacturing system, comprising a support member as described in any of the above examples, and a drive assembly configured to rotate the support member about an axis, such as a longitudinal axis, of the support member, such that, in use, the multi-strand wire is wound on to the support member. The drive assembly causes the support member to rotate, and thereby allows the multi-strand wire to be wound onto the support member. The drive assembly may comprise a drum that is rotated. 
     The system may further comprise a wire feeding assembly for feeding the multi-strand wire on to the support member. In one example, the wire feeding assembly is passive so that it simply holds the multi-strand wire in place while the drive system causes the support member to rotate. The rotating support member therefore draws the wire on to the support member. A passive wire feeding assembly simplifies manufacture. In another example, the wire feeding assembly is active, and actively winds the wire on to the support member. 
     The drive assembly may be further configured to move the support member relative to the wire feeding assembly in a direction parallel to the axis. For example, the drive assembly may move the wire feeding assembly relative to a static support member, or the drive assembly may move the support member relative to the static wire feeding assembly. In a particular example, the drive assembly moves the drum (which is affixed to the support member) along a guide rail that is orientated parallel to the axis of the support member. 
     The system may further comprise a heater for heating the support member. For example, the support member may be heated such that the bondable coating of the multi-strand wire can be activated. 
     The system may further comprise an anchor configured to hold a portion of the multi-strand wire relative to the support member as the multi-strand wire is wound on to the support member. The anchor therefore secures the multi-strand wire and stops it from unravelling as the support member is rotated. 
     In one example, the support member comprises a threaded outer profile to receive the multi-strand wire. The threaded outer profile therefore forms a channel within which the multi-strand wire can be received. 
     According to a fourth aspect, there is provided an inductor coil for an aerosol provision device, the inductor coil being formed according to a method as described above. 
     According to a fifth aspect, there is provided an inductor coil for an aerosol provision device, wherein the inductor coil defines an axis and comprises a multi-strand wire that is wound around the axis, and wherein the multi-strand wire has a cross section with a greatest lateral dimension that is greater than a greatest longitudinal dimension, wherein the greatest lateral dimension is measured in a direction perpendicular to the axis, and the greatest longitudinal dimension is measured in a direction perpendicular to the greatest lateral dimension. 
     According to a sixth aspect, there is provided an aerosol provision device comprising a receptacle for receiving at least part of an article comprising aerosolisable material, and a heating assembly for heating the article when the article is arranged in the receptacle. The heating assembly comprises at least one of the inductor coils of the fourth or fifth or tenth aspects for generating the varying magnetic field for heating a susceptor. In some examples the heating assembly comprises a susceptor which is heatable by penetration with the varying magnetic field. 
     According to a seventh aspect, there is provided a support member that can be moved between two or more configurations. For example, the support member may be moveable between a first configuration and a second configuration. As will become apparent, a support member that changes configuration/shape can make it easier for the formed inductor coil to be removed from the support member. As above, the support member may define an axis (such as a longitudinal axis) about which a wire of the inductor coil is windable. In the first configuration, the wire may be wound around the support member to form the inductor coil. In the second configuration, the cross-sectional width of the support member (measured perpendicular to the axis) is smaller than when the support member is in the first configuration. Accordingly, in the second configuration, the support member has a smaller cross-sectional width. It has been found that reducing the cross-sectional width of the support member (after the inductor coil has been formed) allows the inductor coil to be removed more easily from the support member. For example, by reducing the cross-sectional width of the support member, the wire/coil can be at least partially separated/detached from the support member so that removal of the inductor coil does not damage or deform the inductor coil as it is being removed. 
     In the first configuration, the support member has a first cross-sectional width and in the second configuration, the support member has a second cross-sectional width, where the first cross-sectional width is greater than the second cross-sectional width. 
     In some examples the wire is a multistrand wire. 
     The cross-sectional width is measured perpendicular to the axis defined by the support member. This cross-sectional width may be measured along a second axis, where the second axis is perpendicular to the axis defined by the support member. The axis defined by the support member may be a first axis. In examples where the support member is substantially cylindrical in form, the cross-sectional width of the support member (in the first configuration) is equal to the diameter of the support member. 
     In any of the above examples, the wire is wound around the support member to form the inductor coil. Thus, the wire becomes the inductor coil after it has been formed on the support member. 
     In one example, the support member is monolithic, and formed from a single component. In other examples, however, the support member may be formed from a plurality of components/parts. 
     In a particular example, an outer surface of the support member comprises a channel to receive the wire. As explained above, the channel can receive the wire as it is wound around the support member. The spacing between adjacent turns in the channel can set the spacing between the adjacent turns of the formed inductor coil. In this particular example, the ability for the support member to change configuration is even more useful. The nature of the channel means that the wire extends into the support member, which makes it difficult to remove the inductor coil from the support member. For example, it would be difficult to slide the inductor coil along the length of the support member because it is at least partially located within the channel. By reducing the cross-sectional width of the support member, the inductor coil can be removed more easily. In one example, the cross-sectional width is reduced by at least twice the depth dimension of the channel to ensure that the inductor coil has adequate clearance. 
     The channel can have a depth measured parallel to the second axis, and a width dimension measured parallel to the first axis. 
     The support member may be biased towards the second configuration. Thus, the support member can “automatically” reconfigure to the arrangement in which the cross-sectional width is smallest. A device may hold the support member in the first configuration, when required. 
     In a particular arrangement, the support member may comprise one or more biasing mechanisms, such as one or more springs to bias the support member towards the second configuration. 
     An outer surface of the support member may be formed by a plurality of segments arranged circumferentially around the axis. Thus, in one example, the support member may be formed from a plurality of components. By moving one or more of these segments/components, the support member can be moved between the first and second configurations. 
     In an example, each segment extends along the length of the support member in a direction parallel to the longitudinal axis of the support member. 
     In examples where the support member is substantially cylindrical, each segment may have a curved profile, with an arc length that extends partially around the outer circumference of the support member. 
     The segments may abut one or more adjacent segments. Abutment provides a more continuous outer surface and may also improve heat conduction between segments. 
     At least one segment of the plurality of segments may be configured to move relative to an adjacent segment of the plurality of segments, as the support member moves between the first and second configurations. Thus, as mentioned, the support member can be reconfigured. In a particular example, the at least one segment may rotate/pivot relative to the adjacent segment. 
     In some examples, only a subset of the segments are moveable. For example, only part of the support member may change shape, yet the whole support member may still have a reduced cross-sectional width. 
     At least one segment of the plurality of segments may be connected to an adjacent segment of the plurality of segments via a hinge. Accordingly, there may be two segments that are joined by a hinge. A hinge provides a simple and effective method of moving adjacent segments. One or more of the hinges may be biased, such that the support member is biased towards the second configuration. 
     In some examples, at least one segment of the plurality of segments is not permanently connected to an adjacent segment of the plurality of segments. Thus, not all segments may be permanently connected (via a hinge, for example). This allows one end of the support member to move away from the other end as the support member is moved from the first configuration to the second configuration. 
     In some examples, at least one segment of the plurality of segments has a stop for limiting movement of the at least one segment relative to an adjacent segment thereby to limit the extent to which the support member is movable away from the second configuration. The “stop” ensures that as the support member moves from the second configuration back to the first configuration, the support member moves only to the first configuration, without extending beyond this. “Limit the extent to which the support member is movable away from the second configuration” may mean that the cross-sectional width does not become greater than the cross-sectional width of the support member in the first configuration. The stop can reduce the likelihood of the hinge (which connects the two segments) from bending in the opposite direction. 
     In a particular example, an outer surface of the at least one segment comprises a protruding portion, and an outer surface of the adjacent segment comprises a receiving portion to receive the protruding portion as the support member moves from the second configuration to the first configuration. The “stop” could thus be provided by the receiving portion, and the movement is limited by the protruding portion contacting the receiving portion. The protruding portion might be a lip or flange. The outer surface of each segment is the part furthest away from the longitudinal axis that runs along the centre of the support member. 
     In one example, in the second configuration, the support member is in a spiral configuration. For example, the support member may be rolled or curled in on itself as it moves from the first configuration to the second configuration. In an example where the support member comprises a plurality of segments, the segments may allow the support member to be rolled into the spiral configuration. The spiral configuration may be most evident when viewed along the longitudinal axis of the support member. 
     In one example, in the first configuration, the support member may define a hollow cavity to receive a device to hold the support member in the first configuration. For example, a device may be inserted into the middle of the support member which engages the support member to support it in the first configuration. Such a device may be particularly useful if the support member is biased towards the second configuration. Removal of the device can thus cause the support member to “automatically” move to the second configuration, particularly under the biasing force (when applied). 
     In one example, the device is an inserting member that contacts an inner surface of the support member. The inserting member can be moved in a first direction along the axis of the support member into the hollow cavity, and can be moved in a second direction along the axis, opposite to the first direction. The device/inserting member may have a tapered profile so that as the device is moved in the first direction, the narrowest section of the device is first inserted into the cavity (when the support member is in the second configuration) and as wider sections of the device are inserted, the cross-sectional width of the support member is gradually increased until the support member is in the first configuration. 
     According to the eighth aspect, a system is provided, where the system comprises a support member according to the seventh aspect, and a device configured to cause movement of the support member between the first and second configurations. The device may be the same device that is inserted into the hollow cavity of the support member to hold the support member in the first configuration. 
     As briefly mentioned, the device may be moveable along the axis to cause movement of the support member between the first and second configurations. This provides an effective way of altering the cross-sectional width of the support member with simple automation and few moving parts. 
     The system may be configured so that when the support member is in the first configuration, the device is located at a first position along the axis within a hollow cavity of the support member to hold the support member in the first configuration, and when the support member is in the second configuration, the device is located at a second position along the axis different to the first position. In some examples, in the second configuration, the device may still be partially located within the hollow cavity. In other examples, the device may be fully removed from the hollow cavity. 
     The system may comprise a biasing mechanism for biasing the support member towards the second configuration. In some examples, the biasing mechanism may be separate to the support member. In other examples, the biasing mechanism may be part of the support member. 
     According to a ninth aspect, a method of forming an inductor coil for an aerosol provision device is provided. The method comprises: (i) providing a multi-strand wire comprising a plurality of wire strands, wherein at least one of the plurality of wire strands comprises a bondable coating, (ii) winding the multi-strand wire around a support member defining an axis, (iii) activating the bondable coating such that the multi-strand wire substantially retains a shape determined by the support member, (iv) reducing a cross-sectional width of the support member in a direction perpendicular to the axis, and (v) removing the multi-strand wire from the support member. 
     In an example, winding the wire around the support member may comprise receiving the wire in a channel. 
     Reducing the cross-sectional width of the support member may comprise causing the support member to move between a first configuration and a second configuration, wherein, when the support member is in the second configuration, the cross sectional width of the support member perpendicular to the axis is smaller than when the support member is in the first configuration. 
     Reducing the cross-sectional width of the support member may comprise rolling the support member or collapsing the support member. 
     In one example, when the support member is in the first configuration, a device may be located at a first position along the axis within a hollow cavity of the support member to hold the support member in the first configuration. When the support member is in the second configuration, the device is located at a second position along the axis different to the first position. Thus, causing the support member to move between a first configuration and a second configuration may comprise moving the device between the first position and the second position. 
     As mentioned, an outer surface of the support member may be formed by a plurality of segments arranged circumferentially around the axis. Thus, reducing the cross-sectional width of the support member may comprise moving at least one segment of the plurality of segments relative to an adjacent segment of the plurality of segments. 
     In one example, winding comprises winding the multi-strand wire around the axis, and removing the multi-strand wire from the support member comprises moving the multi-strand wire relative to the support member in a direction parallel to the axis. The support member may be moved in a direction parallel to the axis while the inductor coil is held in place. Alternatively, the inductor coil may be moved, while the support member is fixed in place. 
     According to a tenth aspect, there is provided an inductor coil for an aerosol provision device, the inductor coil formed according to a method comprising the method of the ninth aspect. 
       FIG. 1  shows an example of an aerosol provision device  100  for generating aerosol from an aerosol generating medium/material. In broad outline, the device  100  may be used to heat a replaceable article  110  comprising the aerosol generating medium, to generate an aerosol or other inhalable medium which is inhaled by a user of the device  100 . 
     The device  100  comprises a housing  102  (in the form of an outer cover) which surrounds and houses various components of the device  100 . The device  100  has an opening  104  in one end, through which the article  110  may be inserted for heating by a heating assembly. In use, the article  110  may be fully or partially inserted into the heating assembly where it may be heated by one or more components of the heater assembly. 
     The device  100  of this example comprises a first end member  106  which comprises a lid  108  which is moveable relative to the first end member  106  to close the opening  104  when no article  110  is in place. In  FIG. 1 , the lid  108  is shown in an open configuration, however the lid  108  may move into a closed configuration. For example, a user may cause the lid  108  to slide in the direction of arrow “A”. 
     The device  100  may also include a user-operable control element  112 , such as a button or switch, which operates the device  100  when pressed. For example, a user may turn on the device  100  by operating the switch  112 . 
     The device  100  may also comprise an electrical component, such as a socket/port  114 , which can receive a cable to charge a battery of the device  100 . For example, the socket  114  may be a charging port, such as a USB charging port. 
       FIG. 2  depicts the device  100  of  FIG. 1  with the outer cover  102  removed and without an article  110  present. The device  100  defines a longitudinal axis  134 . 
     As shown in  FIG. 2 , the first end member  106  is arranged at one end of the device  100  and a second end member  116  is arranged at an opposite end of the device  100 . The first and second end members  106 ,  116  together at least partially define end surfaces of the device  100 . For example, the bottom surface of the second end member  116  at least partially defines a bottom surface of the device  100 . In this example, the lid  108  also defines a portion of a top surface of the device  100 . 
     The end of the device  100  closest to the opening  104  may be known as the proximal end (or mouth end) of the device  100  because, in use, it is closest to the mouth of the user. In use, a user inserts an article  110  into the opening  104 , operates the user control  112  to begin heating the aerosol generating material and draws on the aerosol generated in the device. This causes the aerosol to flow through the device  100  along a flow path towards the proximal end of the device  100 . 
     The other end of the device furthest away from the opening  104  may be known as the distal end of the device  100  because, in use, it is the end furthest away from the mouth of the user. As a user draws on the aerosol generated in the device, the aerosol flows away from the distal end of the device  100 . 
     The device  100  further comprises a power source  118 . The power source  118  may be, for example, a battery, such as a rechargeable battery or a non-rechargeable battery. The battery is electrically coupled to the heating assembly to supply electrical power when required and under control of a controller (not shown) to heat the aerosol generating material. In this example, the battery is connected to a central support  120  which holds the battery  118  in place. 
     The device further comprises at least one electronics module  122 . The electronics module  122  may comprise, for example, a printed circuit board (PCB). The PCB  122  may support at least one controller, such as a processor, and memory. The PCB  122  may also comprise one or more electrical tracks to electrically connect together various electronic components of the device  100 . For example, the battery terminals may be electrically connected to the PCB  122  so that power can be distributed throughout the device  100 . The socket  114  may also be electrically coupled to the battery via the electrical tracks. 
     In the example device  100 , the heating assembly is an inductive heating assembly and comprises various components to heat the aerosol generating material of the article  110  via an inductive heating process. Induction heating is a process of heating an electrically conducting object (such as a susceptor) by electromagnetic induction. An induction heating assembly may comprise an inductive element, for example, one or more inductor coils, and a device for passing a varying electric current, such as an alternating electric current, through the inductive element. The varying electric current in the inductive element produces a varying magnetic field. The varying magnetic field penetrates a susceptor suitably positioned with respect to the inductive element, and generates eddy currents inside the susceptor. The susceptor has electrical resistance to the eddy currents, and hence the flow of the eddy currents against this resistance causes the susceptor to be heated by Joule heating. In cases where the susceptor comprises ferromagnetic material such as iron, nickel or cobalt, heat may also be generated by magnetic hysteresis losses in the susceptor, i.e. by the varying orientation of magnetic dipoles in the magnetic material as a result of their alignment with the varying magnetic field. In inductive heating, as compared to heating by conduction for example, heat is generated inside the susceptor, allowing for rapid heating. Further, there need not be any physical contact between the inductive heater and the susceptor, allowing for enhanced freedom in construction and application. 
     The induction heating assembly of the example device  100  comprises a susceptor arrangement  132  (herein referred to as “a susceptor”), a first inductor coil  124  and a second inductor coil  126 . The first and second inductor coils  124 ,  126  are made from an electrically conducting material. In this example, the first and second inductor coils  124 ,  126  are made from a multi-strand wire, such as a litz wire/cable which is wound in a generally helical fashion to provide the inductor coils  124 ,  126 . Litz wire comprises a plurality of wire strands which are individually insulated and are twisted together to form a single wire. Litz wires are designed to reduce the skin effect losses in a conductor. In the example device  100 , the first and second inductor coils  124 ,  126  are made from copper Litz wire which has a rectangular cross section. In other examples the Litz wire can have other shape cross sections. 
     The first inductor coil  124  is configured to generate a first varying magnetic field for heating a first section of the susceptor  132  and the second inductor coil  126  is configured to generate a second varying magnetic field for heating a second section of the susceptor  132 . In this example, the first inductor coil  124  is adjacent to the second inductor coil  126  in a direction parallel to the longitudinal axis  134  of the device  100 . Ends  130  of the first and second inductor coils  124 ,  126  can be connected to the PCB  122 . 
     It will be appreciated that the first and second inductor coils  124 ,  126 , in some examples, may have at least one characteristic different from each other. For example, the first inductor coil  124  may have at least one characteristic different from the second inductor coil  126 . More specifically, in one example, the first inductor coil  124  may have a different value of inductance than the second inductor coil  126 . In  FIG. 2 , the first and second inductor coils  124 ,  126  are of different lengths such that the first inductor coil  124  is wound over a smaller section of the susceptor  132  than the second inductor coil  126 . Thus, the first inductor coil  124  may comprise a different number of turns than the second inductor coil  126  (assuming that the spacing between individual turns is substantially the same). In yet another example, the first inductor coil  124  may be made from a different material to the second inductor coil  126 . In some examples, the first and second inductor coils  124 ,  126  may be substantially identical. 
     The susceptor  132  of this example is hollow and therefore defines a receptacle within which aerosol generating material is received. For example, the article  110  can be inserted into the susceptor  132 . In this example the susceptor  120  is tubular, with a circular cross section. 
     The device  100  of  FIG. 2  further comprises an insulating member  128  which may be generally tubular and at least partially surround the susceptor  132 . The insulating member  128  may be constructed from any insulating material, such as plastic for example. In this particular example, the insulating member is constructed from polyether ether ketone (PEEK). The insulating member  128  may help insulate the various components of the device  100  from the heat generated in the susceptor  132 . 
     The insulating member  128  can also fully or partially support the first and second inductor coils  124 ,  126 . For example, as shown in  FIG. 2 , the first and second inductor coils  124 ,  126  are positioned around the insulating member  128  and are in contact with a radially outward surface of the insulating member  128 . In some examples the insulating member  128  does not abut the first and second inductor coils  124 ,  126 . For example, a small gap may be present between the outer surface of the insulating member  128  and the inner surface of the first and second inductor coils  124 ,  126 . 
     In a specific example, the susceptor  132 , the insulating member  128 , and the first and second inductor coils  124 ,  126  are coaxial around a central longitudinal axis of the susceptor  132 . 
       FIG. 3  shows a side view of device  100  in partial cross-section. The outer cover  102  is present in this example. 
     The device  100  further comprises a support  136  which engages one end of the susceptor  132  to hold the susceptor  132  in place. The support  136  is connected to the second end member  116 . 
     The device may also comprise a second printed circuit board  138  associated within the control element  112 . 
     The device  100  further comprises a second lid/cap  140  and a spring  142 , arranged towards the distal end of the device  100 . The spring  142  allows the second lid  140  to be opened, to provide access to the susceptor  132 . A user may open the second lid  140  to clean the susceptor  132  and/or the support  136 . 
     The device  100  further comprises an expansion chamber  144  which extends away from a proximal end of the susceptor  132  towards the opening  104  of the device. Located at least partially within the expansion chamber  144  is a retention clip  146  to abut and hold the article  110  when received within the device  100 . The expansion chamber  144  is connected to the end member  106 . 
       FIG. 4  is an exploded view of the device  100  of  FIG. 1 , with the outer cover  102  omitted. 
       FIG. 5A  depicts a cross section of a portion of the device  100  of  FIG. 1 .  FIG. 5B  depicts a close-up of a region of  FIG. 5A .  FIGS. 5A and 5B  show the article  110  received within the susceptor  132 , where the article  110  is dimensioned so that the outer surface of the article  110  abuts the inner surface of the susceptor  132 . The article  110  of this example comprises aerosol generating material  110   a . The aerosol generating material  110   a  is positioned within the susceptor  132 . The article  110  may also comprise other components such as a filter, wrapping materials and/or a cooling structure. 
       FIG. 5B  shows that the outer surface of the susceptor  132  is spaced apart from the inner surface of the inductor coils  124 ,  126  by a distance  150 , measured in a direction perpendicular to a longitudinal axis  158  of the susceptor  132 . In one particular example, the distance  150  is about 3 mm to 4 mm, about 3 mm to 3.5 mm, or about 3.25 mm. 
       FIG. 5B  further shows that the outer surface of the insulating member  128  is spaced apart from the inner surface of the inductor coils  124 ,  126  by a distance  152 , measured in a direction perpendicular to a longitudinal axis  158  of the susceptor  132 . In one particular example, the distance  152  is about 0.05 mm. In another example, the distance  152  is substantially 0 mm, such that the inductor coils  124 ,  126  abut and touch the insulating member  128 . 
     In one example, the susceptor  132  has a wall thickness  154  of about 0.025 mm to 1 mm, or about 0.05 mm. 
     In one example, the susceptor  132  has a length of about 40 mm to 60 mm, about 40 mm to 45 mm, or about 44.5 mm. 
     In one example, the insulating member  128  has a wall thickness  156  of about 0.25 mm to 2 mm, 0.25 mm to 1 mm, or about 0.5 mm. 
       FIG. 6  depicts part of the heating assembly of the device  100 . As briefly mentioned above, the heating assembly comprises a first inductor coil  124  and a second inductor coil  126  arranged adjacent to each other, in the direction along an axis  200 . The inductor coils  124 ,  126  extend around the insulating member  128 . The susceptor  132  is arranged within the tubular insulating member  128 . In this example, the wires forming the first and second inductor coils  124 ,  126  have a circular or elliptical cross section, however they may have a different shape cross section such as a rectangular, square, “L”, “T” or triangular cross section. 
     The axis  200  may be defined by one, or both, of the inductor coils  124 ,  126 . For example, the axis  200  may be a longitudinal axis of any one of the inductor coils  124 ,  126 . The axis  200  is parallel to the longitudinal axis  134  of the device  100 , and is parallel to the longitudinal axis  158  of the susceptor. Each inductor coil  124 ,  126  therefore extends around the axis  200 . 
     Each inductor coil  124 ,  126  is formed from a multi-strand wire, such as a litz wire, which comprises a plurality of wire strands. For example, there may be between about 50 and about 150 wire strands in each multi-strand wire. In the present example, there are about 115 wire strands in each multi-strand wire. 
     Each of the individual wire strands has a diameter. For example, the diameter may be between about 0.05 mm and about 0.2 mm. In some examples, the diameter is between 34 AWG (0.16 mm) and 40 AWG (0.0799 mm), where AWG is the American Wire Gauge. In this example, each of the wire strands have a diameter of 38 AWG (0.101 mm). 
     In an example where the multi-strand wire has a circular cross-section, the multi-strand wire may have a diameter of between about 1 mm and about 2 mm. In this example, the multi-strand wire has a diameter of between about 1.3 mm and about 1.5 mm, such as about 1.4 mm. 
     As shown in  FIG. 6 , the multi-strand wire of the first inductor coil  124  is wrapped around the axis  202  about 6.75 times, and the multi-strand wire of the second inductor coil  126  is wrapped around the axis  202  about 8.75 times. The multi-strand wires do not form a whole number of turns because some ends of the multi-strand wire are bent away from the surface of the insulating member  128  before a full turn is completed. In other examples, there may be different number of turns. For example, each multi-strand wire may be wrapped around the axis  202  between about 4 to 15 times. 
       FIG. 6  shows gaps between successive windings/turns. These gaps may be between about 0.5 mm and about 2 mm, for example. 
     In some examples, each inductor coil  124 ,  126  has the same pitch, where the pitch is the length of the inductor coil (measured along the axis  200  of the inductor coil or along the longitudinal axis  158  of the susceptor) over one complete winding. In other examples each inductor coil  124 ,  126  has a different pitch. 
     In one example the inner diameter of the first and second inductor coils  124 ,  126  is about 12 mm in length, and the outer diameter is about 14.3 mm in length. In another example, the inner diameter of the first and second inductor coils  124 ,  126  may be between about 8 mm to about 15 mm and the outer diameter may be between about 10 mm to about 17 mm. 
       FIG. 7  depicts a flow diagram of a method  300  for forming an aerosol provision device inductor coil. Such a method can be used to form one, or both, of the inductor coils  124 ,  126  described in relation to  FIGS. 2-6 . 
     The method comprises, in block  302 , providing a multi-strand wire comprising a plurality of wire strands, wherein at least one of the plurality of wire strands comprises a bondable coating. For example, a multi-strand wire with parameters described above may be provided. As mentioned above, a bondable coating is a coating which surrounds the wire strand, and can be activated (such as via heating), so that the strands within the multi-strand wire bond to one more neighbouring strands. The bondable coating allows the multi-strand wire to be formed into the shape of an inductor coil on a support member, and after the bondable coating is activated, the multi-strand wire will retain its shape. The bondable coating therefore “sets” the shape of the inductor coil. 
     The method further comprises, in block  304 , winding the multi-strand wire around a support member. For example, the multi-strand wire may be wound around the support member in a helical fashion. 
       FIG. 8  depicts an example system used to form an inductor coil  400  from multi-strand wire. As shown, a multi-strand wire  402  may be initially wound around a bobbin  404  before being unraveled and wound around a support member  406 . In this example, a drum  408  is rotated and moved parallel to a guide rail  410  which causes the multi-strand wire to be wound along the length of the support member  406 . The drum  408  and guide rail  410  form part of a drive assembly which together wind the multi-strand wire  402  onto the support member  406 . 
     In a particular example, the support member  406  has a channel formed in its outer surface. Thus, as the multi-strand wire  402  is wound onto the support member  406 , the multi-strand wire  402  may be received in the channel. The channel provides a means to better control the shape and dimensions of the multi-strand wire  402  which forms the inductor coil  400 . The channel may helically extend around the support member  406 . 
     In some examples, the channel has a particular cross-sectional shape which is imparted to the multi-strand wire  402 . The channel may therefore act as a “mould” such that the multi-strand wire  402  takes on the shape of the channel. 
       FIG. 9A  depicts an alternative view of the multi-strand wire  402  being wound around the support member  406 . At this moment in time, the inductor coil  400  is only partially formed, and the multi-strand wire  402  is still being wound onto the support member  406 . A channel  412  can be seen extending around the outer surface of the support member  406 . As the multi-strand wire  402  is wound around the support member  406 , it falls into the channel  412 . The channel therefore provides a means of accurately controlling the spacing between adjacent turns in the inductor coil  400 . 
       FIGS. 8 and 9A  also show a wire feeding assembly  414  which allows or controls the feeding of the multi-strand wire  402  onto the support member  406 . In some examples, the wire feeding assembly  414  is passive, as shown in  FIGS. 8 and 9A . For example, as mentioned, the system may comprise a drive assembly configured to cause the support member  406  to rotate around a longitudinal axis  416  defined by the support member  406 . The system may also comprise an anchor  418  which holds an end portion of the multi-strand wire  402  in place. As the drive assembly rotates the support member  406  in the direction shown by arrow  420 , and moves the support member  406  in a direction parallel to the longitudinal axis  416 , the multi-strand wire  402  is drawn through the passive wire feeding assembly  414  and onto the support member  406 . 
     In other examples, the wire feeding assembly  414  is active, and actively winds the multi-strand wire onto the support member  406 . For example, the wire feeding assembly  414  may spin around the support member  406  while the wire is wound onto the support member  406 . 
       FIG. 9B  shows the system of  FIG. 9A  at a later time. At this moment in time, the inductor coil  400  is still only partially formed, but the multi-strand wire  402  has been wound around the support member  406  a greater number of times. The drive assembly has caused the support member  406  to rotate, and has moved the support member  406  in a direction  422  that is parallel to the longitudinal axis  416 , while the wire feeding assembly  414  remains stationary. In alternative example, the drive assembly may move the wire feeding assembly  414  in a direction parallel to the longitudinal axis  416 , while the longitudinal displacement of the support member  406  remains stationary. In either case, the drive assembly moves the support member  406  relative to the wire feeding assembly  414  to cause the multi-strand wire  402  to be wound onto the support member  406 . The multi-strand wire  402  continues to be wound onto the support member  406  until the inductor coil  400  has a desired length. The multi-strand wire  402  may be cut to size using a cutting tool  424  (shown in  FIG. 8 ). 
     As the multi-strand wire  402  is being wound around the support member  406 , the method  300  further comprises, in block  306 , activating the bondable coating such that the multi-strand wire substantially retains a shape provided by the channel. Alternatively, block  306  may occur after the multi-strand wire  402  has been fully wound around the support member  406 . In the present example the multi-strand wire has an enamel bondable coating, and is activated via heating. Accordingly, while the multi-strand wire  402  remains on the support member  406  and in the channel  412 , heat is applied to the multi-strand wire  402 . For example, the support member  406  may be heated by a heater (not shown) which in turn causes the multi-strand wire  402  to be heated. In one example, the multi-strand wire  402  is heated to an activation temperature of about 190° C. which causes the viscosity of the bondable coating to become lower. After a predetermined period of time, the application of heat is stopped, and the bondable coating begins to cool. In some examples the cooling process can be accelerated by the application of cool air. For example, an air gun or fan may cause cooled/ambient air to flow across the multi-strand wire  402 . As the temperature of the bondable coating lowers, the viscosity of the bondable coating becomes higher again. This causes the individual wire strands within the multi-strand wire bond to each other. 
     In an alternative example, heated air is moved over the multi-strand wire  402 . For example, air is heated to an activation temperature suitable to cause the bondable coating to activate, and is moved across the inductor coil  400  via a fan or air gun. 
     Preferably, in either example, the heat is applied to the multi-strand wire  402  at the same time the multi-strand wire  402  is wound around the support member  406 . 
     The combined effect of receiving the multi-strand wire  402  in the channel and activating the bondable coating causes the cross-sectional shape of the channel  412  to be imparted to the multi-strand wire  402 . For example, the multi-strand wire  402  may have a certain cross-sectional shape before being introduced into the channel  412 , and may have a different cross-sectional shape after being removed from the channel  412 . The channel  412  therefore provides a means for modifying the cross-sectional shape of the multi-strand wire  402 . Various example support members having channels with different predetermined cross-sectional shapes will be described in relation to  FIGS. 10-15 . 
       FIG. 10A  depicts a side-view of a first example support member  500 .  FIG. 10B  depicts a close-up of a portion of  FIG. 10A . The support member  500  defines a longitudinal axis  502  about which a multi-strand wire  504  can be wound. The outer surface of the support member  500  comprises a channel  506  to receive the multi-strand wire  504 . 
     As shown most clearly in  FIG. 10B , the channel  506  of this example comprises a tapered mouth portion  508  and a wire receiving portion  510 . The tapered mouth portion  508  is arranged towards the outer surface of the support member  500  and the wire receiving portion  510  is arranged radially inward, towards the centre of the support member  500 . In some examples, the tapered mouth portion  508  may be omitted. 
     The tapered mouth portion  508  defines a guide for guiding the multi-strand wire  504  into the wire receiving portion  510  of the channel  506 . For example, the inclined surfaces of the tapered mouth portion  508  can “funnel” the multi-strand wire  504  into the channel  506  if it is not accurately aligned with the channel as it is being wound onto the support member  500 . The wire receiving portion  510  is the part of the channel  506  which holds or abuts the multi-strand wire  504  once it has been fully received in the channel  506 . 
     In the present example, the wire receiving portion  510  imparts a pre-determined cross-sectional shape to the multi-strand wire  504 .  FIG. 10B  shows the multi-strand wire  504  with a generally circular cross-sectional shape before entering the wire receiving portion  510 . As the multi-strand wire  504  is fully received in the wire receiving portion  510 , the multi-strand wire  504  may be constricted in one or more dimensions, thereby modifying the cross-section of the multi-strand wire  504 . 
     As shown in  FIG. 10B , the channel  506  has a greatest depth dimension  512  measured in direction perpendicular to the longitudinal axis  502 , and a greatest width dimension  514  measured in a direction perpendicular to the greatest depth dimension  512 . The greatest depth dimension  512  is therefore the overall depth of the channel  506 . In this example, the greatest depth dimension  512  is greater than the greatest width dimension  514 . Overall, the  506  channel  506  has a width dimension that reduces with distance towards a base  506   a  of the channel  506 . Similarly, the wire receiving portion  510  has a width dimension that reduces with distance towards a base  506   a  of the channel  506 . 
     As also shown in  FIG. 10B , the wire receiving portion  510  has a greatest depth  516  measured in direction perpendicular to the longitudinal axis  502 , and a greatest width  518  measured in a direction perpendicular to the greatest depth  516 . The greatest depth  516  is therefore the overall depth of the wire receiving portion  510 . In this example, the greatest depth  512  is greater than the greatest width  514 . Due to this particular shape, the multi-strand wire  504  is constricted/compressed in a dimension parallel to the longitudinal axis  502  and is elongated in a dimension perpendicular to the longitudinal axis  502  as the wire is fully received in the channel  506 . Thus, the cross-sectional shape of the wire receiving portion  510  is imparted to the multi-strand wire  504 . The multi-strand wire  504  therefore acquires the same cross-sectional shape provided by the channel  506 . 
     The resultant multi-strand wire  504  therefore has a greatest lateral dimension that is greater than a greatest longitudinal dimension. The greatest longitudinal dimension is measured in a direction parallel to the longitudinal axis  502 , and the greatest lateral dimension is measured in a direction perpendicular to the greatest longitudinal dimension. The greatest lateral dimension of the multi-strand wire  504  is therefore substantially the same as the greatest depth  516 . Similarly, the greatest longitudinal dimension of the multi-strand wire  504  is substantially the same as the greatest width  518 . 
     In a particular example, the multi-strand wire  504  has a diameter of about 1.4 mm before being introduced into the channel  506 . The greatest depth  516  is about 1.7 mm and the greatest width  518  is about 1.4 mm. Thus, after being received in the channel  506 , the greatest longitudinal dimension of the multi-strand wire  504  remains about 1.4 mm. However, the greatest lateral dimension of the multi-strand wire is increased to about 1.7 mm. The wire strands within the multi-strand wire  504  may therefore become more densely packed in a dimension parallel to the longitudinal axis  502 . The wire strands may become less densely packed in a dimension perpendicular to the longitudinal axis  502  as they move. 
     After the multi-strand wire has been received in the channel, and after the bondable coating has been activated to impart the predetermined cross-sectional shape of the channel to the multi-strand wire, the method further comprises, in block  308 , removing the multi-strand wire from the support member. For example, the multi-strand wire may be unwound from the support member. Unwinding the multi-strand wire itself to remove it from the support member may be suitable if the wire has sufficient elasticity, and returns to its coiled shape after unwinding. Alternatively, removing the multi-strand wire from the support member may comprise one of: (i) unscrewing the support member from the coil (i.e. by holding the coil stationary while rotating and withdrawing the support member), or (ii) unscrewing the coil from the support member (i.e. by holding the support member stationary while rotating and withdrawing the coil), or (iii) sliding the coil off the support member or vice versa (if the coil has sufficient elasticity to pass over the raised sections between adjacent troughs of the channel). In at least alternatives (i) and (ii), the channel may have a constant pitch along the length of the support member and/or may extend all the way to one end of the support member, to allow the coil to be more easily separated from the support member. 
     By setting the shape of multi-strand wire using the bondable coating, the inductor coil substantially retains its shape even after it is removed from the support member. To facilitate removal from the support member, the support member may be formed from or coated with a material to which the multi-strand wire does not adhere strongly, so that the multi-strand wire is not also bonded to the support member during the activation process. The support member may be made of metal, for example. 
     Once the inductor coil has been formed and removed from the support member, the inductor coil can be assembled in the device  100 . The inductor coil may be received on the insulating member  128 . For example, the inductor coil can be slid onto the insulating member  128 . 
       FIG. 10C  depicts another closeup of a portion of  FIG. 10A  to more clearly illustrate the tapered mouth portion  508  and the wire receiving portion  510 . In this example, a first surface  520  of the tapered mouth portion  508  has a first surface gradient, and a second surface  522   a  of the wire receiving portion  510  adjacent the tapered mouth portion  508  has a second surface gradient that is greater than the first surface gradient. In other words, the angle of incline  524  of the first surface  520  is smaller than the angle of incline  526  of the second surface  522   a . The surface gradients and angle of inclines are defined relative to the longitudinal axis  502 . A smaller angle of incline indicates a shallower/smaller gradient. The shallower gradient of the tapered mouth portion  508  provides a smooth transition for the multi-strand wire to be guided in to the channel  506 . The second surface  522   a  (i.e. the surface directly adjacent the tapered mouth portion  508 ), is vertical in this example. In other examples, the second surface  522   a  may not be vertical. For example, the surface adjacent the tapered mouth portion  508  may have a gradient like that of the third surface  522   b . The third surface  522   b  has a third surface gradient that is greater than the first surface gradient, and an angle of incline  528  that is greater than the angle of incline  524  of the first surface  520 . 
       FIG. 11  depicts a side-view of a second example support member  550 . The support member  550  defines a longitudinal axis  552  about which a multi-strand wire  554  can be wound. The outer surface of the support member  550  comprises a helical channel  556  with a V-shaped cross-section to receive the multi-strand wire  554 . 
     The channel  556  of this example comprises a tapered mouth portion  558  and a wire receiving portion  560  that are continuous. That is, a first surface of the tapered mouth portion  558  has a first surface gradient, and a second surface of the wire receiving portion  560  adjacent the tapered mouth portion  558  has a second surface gradient that is equal to the first surface gradient. 
     In this example, the wire receiving portion  560  imparts a pre-determined cross-sectional shape to the multi-strand wire  554 .  FIG. 11  shows the multi-strand wire  554  with a generally circular cross-sectional shape before entering the wire receiving portion  560 . As the multi-strand wire  554  is fully received in the wire receiving portion  560 , the multi-strand wire  554  may be constricted in one or more dimensions, thereby modifying the cross-section of the multi-strand wire  554 . 
     In this example, as in the example of  FIG. 10B , the greatest depth  566  of the wire receiving portion  560  is greater than the greatest width  568  of the wire receiving portion  560 . Due to this particular shape, the multi-strand wire  554  is constricted in a dimension parallel to the longitudinal axis  552  and is elongated in a dimension perpendicular to the longitudinal axis  552  as the wire is fully received in the channel  556 . Thus, the cross-sectional shape of the wire receiving portion  560  is imparted to the multi-strand wire  554 . The multi-strand wire  554  therefore acquires the same cross-sectional shape provided by the channel  556 . The multi-strand wire  554  there has a greatest lateral dimension that is greater than a greatest longitudinal dimension. 
       FIG. 12  depicts a side-view of a third example support member  600 . The support member  600  of this example differs from that shown in  FIGS. 10A-11  in that the channel has a flat floor/base. The deepest section of the channel  606  is therefore flat. The example support member  600  may be used to manufacture an inductor coil in which the multi-strand wire has a shape with at least one flat side, such as rectangular and has a greatest longitudinal dimension that is greater than a greatest lateral dimension. 
     As in previous examples, the support member  600  defines a longitudinal axis  602  about which a multi-strand wire  604  can be wound. The outer surface of the support member  600  comprises a channel  606  to receive the multi-strand wire  604 . 
     The channel  606  comprises a tapered mouth portion  608  and a wire receiving portion  610 . In the present example, the wire receiving portion  610  imparts a pre-determined cross-sectional shape to the multi-strand wire  604 .  FIG. 12  shows the multi-strand wire  604  with a generally circular cross-sectional shape before entering the wire receiving portion  610 . As the multi-strand wire  604  is fully received in the wire receiving portion  610 , the multi-strand wire  604  may be constricted in one or more dimensions, thereby modifying the cross-section of the multi-strand wire  604 . 
     In this example, the greatest width  618  of the wire receiving portion  610  is greater than the greatest depth  616  of the wire receiving portion  610 . Due to this particular shape, the multi-strand wire  604  is imparted with a cross-sectional shape which has a greatest longitudinal dimension that is greater than a greatest lateral dimension. The multi-strand wire  604  therefore acquires the same cross-sectional shape provided by the channel  606 . 
       FIG. 13  depicts a side-view of a fourth example support member  650 . The support member  650  of this example differs from that shown in  FIGS. 10A-12  in that the channel does not have a tapered mouth portion, and it has a rounded base. The deepest section of the channel  656  is therefore rounded. As in previous examples, the support member  650  defines a longitudinal axis  652  about which a multi-strand wire  654  can be wound. The outer surface of the support member  650  comprises a generally helical channel  656  with a U-shaped cross-section to receive the multi-strand wire  654 . 
     In the present example, the wire receiving portion  660  imparts a pre-determined cross-sectional shape to the multi-strand wire  664 .  FIG. 13  shows the multi-strand wire  604  with a generally elliptical cross-sectional shape before entering the wire receiving portion  660 . As the multi-strand wire  604  is fully received in the wire receiving portion  660 , the multi-strand wire  654  may be constricted in one or more dimensions, thereby modifying the cross-section of the multi-strand wire  654 . In other examples, the rounded base of the channel may mean that the multi-strand wire  654  substantially retains its original cross-sectional shape. 
     As mentioned, the channel  656  does not comprise a tapered mouth portion. That is, the mouth portion  658  of the channel  656  has a width dimension that is generally constant with distance towards the wire receiving portion  660 . Instead, it is the wire-receiving portion  660  which has a width dimension that reduces with distance towards a base of the channel  656 . 
       FIG. 14  depicts a side-view of a fifth example support member  700 . The support member  700  of this example is similar to that shown in  FIG. 13 , but instead the channel has a tapered mouth portion  708 . As in previous examples, the support member  700  defines a longitudinal axis  702  about which a multi-strand wire  704  can be wound. The outer surface of the support member  700  comprises a generally U-shaped channel  706  to receive the multi-strand wire  704 . 
     In the present example, the wire receiving portion  710  imparts a pre-determined cross-sectional shape to the multi-strand wire  704 .  FIG. 13  shows the multi-strand wire  704  with a generally circular cross-sectional shape before entering the wire receiving portion  710 . As the multi-strand wire  704  is fully received in the wire receiving portion  710 , the multi-strand wire  704  may be constricted in one or more dimensions, thereby modifying the cross-section of the multi-strand wire  704 . In other examples, the rounded base of the channel may mean that the multi-strand wire  704  substantially retains its original shape. 
       FIG. 15  depicts a side-view of a sixth example support member  750 . The support member  600  of this example has a flat base and has a wire receiving portion  760  that has a greatest depth  766  that is greater than the greatest width  768  of the wire receiving portion. As in previous examples, the support member  750  defines a longitudinal axis  752  about which a multi-strand wire  754  can be wound. The outer surface of the support member  750  comprises a channel  756  to receive the multi-strand wire  754 . 
     The channel  756  comprises a tapered mouth portion  758  and a wire receiving portion  760 . In the present example, the wire receiving portion  760  imparts a pre-determined cross-sectional shape to the multi-strand wire  754 .  FIG. 15  shows the multi-strand wire  754  with a generally circular cross-sectional shape before entering the wire receiving portion  760 . As the multi-strand wire  754  is fully received in the wire receiving portion  760 , the multi-strand wire  754  may be constricted in one or more dimensions, thereby modifying the cross-section of the multi-strand wire  754 . 
     In this example, the greatest depth  766  of the wire receiving portion  760  is greater than the greatest width  768  of the wire receiving portion  760 . Due to this particular shape, the multi-strand wire  754  is imparted with a cross-sectional shape which has a greatest lateral dimension that is greater than a greatest longitudinal dimension. The multi-strand wire  754  therefore acquires the same cross-sectional shape provided by the channel  756 . The multi-strand wire  754  may therefore have a generally rectangular shape. 
     The support member in the above-described examples has a fixed cross-sectional width perpendicular to the axis defined by the support member. In other examples, the cross-sectional width of the support member may be variable. An example support member having a variable cross-sectional width will be described in relation to  FIGS. 16A-20 . It should be noted that the support member(s) described in the above examples may also have a variable cross-sectional width in combination with the features described in those examples. Similarly, the support member(s) described in  FIGS. 16A-20  may also have any of the features described in the above examples. 
       FIG. 16A  depicts an example support member  800  that can be moved between two or more configurations. In  FIG. 16A , the support member  800  defines a first axis  802 , such as a longitudinal axis. A second axis  804  is arranged perpendicular to the first axis  802 . In  FIG. 16A , the support member  800  is arranged in a first configuration in which the support member  800  has a first cross-sectional width  806 . While the support member may take any shape, the support member  800  in this example has a cylindrical shape and a diameter equal to the first cross-sectional width  806 . 
     An outer surface of the support member  800  has a channel  808 , such as a helical channel, that extends around the first axis  802  along a length of the support member  800 . As described above, a wire can be wound around the support member  800  and be received within the channel  808 . In other examples, the channel may be omitted, and the wire may be wound directly onto the outer surface of the support member  800 . In either case, the support member  800  is arranged in the first configuration while the inductor coil is being formed.  FIG. 16B  shows a wire  810  wound around the support member  800  to form an inductor coil. 
       FIG. 16C  shows a cross-sectional view of the support member of  FIG. 16A  viewed along the direction “A”.  FIG. 16D  shows a cross-sectional view of the support member of  FIG. 16B  viewed along the direction “B”. 
     In these examples, the channel  808  has a variable pitch along the length of the support member  800 . In other words, the spacing between adjacent turns may vary along the length of the support member  800 . In other examples however, the channel  808  may have a constant pitch. 
       FIG. 17A  depicts the support member  800  arranged in a second configuration, after the cross-sectional width of the support member  800  has been reduced. In  FIG. 17A , the support member  800  has a second cross-sectional width  812  that is smaller than the first cross-sectional width  806 . This can be achieved via many different mechanisms, but in this example, the support member has been collapsed by rolling the support member  800  into a spiral configuration.  FIG. 17A  shows the support member  800  without the wire  810 , whereas  FIG. 17B  shows the wire  810  after it has been formed into an inductor coil. In contrast to  FIG. 16B ,  FIG. 17B  shows that as the cross-sectional width of the support member  800  is reduced, the wire  810  (and therefore the inductor coil) is loosened and can be easily removed from the support member  800 . The inductor coil can be moved along the length of the support member  800  and removed from the support member  800  entirely. By reducing the cross-sectional width of the support member  800  after the inductor coil has been formed, removal of the inductor coil is less likely to damage or deform the final shape of the coil. 
       FIG. 17C  shows a cross-sectional view of the support member of  FIG. 17A  viewed along the direction “C”.  FIG. 17D  shows a cross-sectional view of the support member of  FIG. 17B  viewed along the direction “D”. 
     Returning to  FIG. 16A , the support member  800  is shown formed from a plurality of segments  814  arranged circumferentially around the first axis  802 . That is, each segment extends partially around the outer circumference/perimeter of the support member  800 . Each segment  814  extends along the length of the support member  800  in a direction parallel to the first axis  802 . The segments  814  are relatively movable to allow the support member  800  to be moved between the first and second configurations. 
       FIG. 18A  shows an end view the support member  800  of  FIG. 16A  when viewed along the first axis  802 . Thus, in  FIG. 18A , the support member  800  is arranged in the first configuration.  FIG. 18B  shows an end view the support member  800  of  FIG. 17A  when viewed along the first axis  802 . Thus, in  FIG. 18B , the support member  800  is arranged in the second configuration. In both  FIGS. 18A and 18B , the first axis  802  extends into the page. 
     The support member  800  has eight segments in this example but may have more or fewer segments in other examples. Three segments  814   a ,  814   b ,  814   c  are labelled for reference. Each segment has an arc length  818  that extends at least partially around the outer circumference of the support member  800 . The segments are therefore arranged circumferentially around the first axis  802 . 
     With reference to  FIG. 18A , a first segment  814   a  is arranged adjacent a second segment  814   b , and the first segment  814   a  is configured to move relative to the second segment  814   b  as the support member  800  moves between the first and second configurations. For example, the second segment  814   b  may rotate or pivot relative to the first segment  814   a , in the direction  816 .  FIG. 18B  shows the second segment  814   b  after it has rotated towards the first segment  814   a . To enable this rotation, the adjacent segments  814   a ,  814   b  may be connected via a hinge  820 . It should be noted that only one hinge is depicted in  FIGS. 18A and 18B  for simplicity. Several other segments may also be connected via hinges. Moreover, each pair of the adjacent segments may be connected by a plurality of hinges. 
     A third segment  814   c  is arranged adjacent the second segment  814   b , and the third segment  814   c  is configured to move relative to the second segment  814   b  as the support member  800  moves between the first and second configurations. In this example, the second segment  814   b  is not permanently connected to the adjacent third segment  814   c . Instead, the two segments  814   b ,  814   c  may abut when in the first configuration, and be moved apart as the support member moves towards the second configuration (as shown in  FIG. 18B ). The second segment  814   b  may thus form one end of the support member&#39;s circumference, and the third segment  814   c  may form an opposite end of the circumference. By moving these two segments  814   b ,  814   c  relative to each other, the support member  800  can be moved between the first and second configurations. In the second configuration, the support member  800  may be said to be arranged in a spiral/rolled configuration because the outer edge of the support member spirals inwards as the segments are moved. 
     In some examples, it may be advantageous to stop the segments from pivoting in the opposite direction to that intended. For example, it may be useful to only permit rotation in the direction of arrow  816 , and restrict rotation in the direction of arrow  822  shown in  FIG. 18A . To limit this movement, each segment may comprise a stop for limiting movement of the segment relative to an adjacent segment. The stop therefore limits the extent to which the support member  800  is movable away from the second configuration (i.e. it cannot move beyond the first configuration). To provide the stop, each segment may comprise a receiving portion  824  to interlock with a protruding portion  826  on an adjacent segment. This interlocking of components, in addition to the support provided by the hinge, stops the adjacent segments from moving in the opposite direction. The receiving portion may be in the form of a recess or cut-away portion, and the protruding portion may be in the form of a lip or extremity that docks with the receiving portion. Other forms of stop may be employed in other examples. 
     In this particular example, the support member  800  is biased towards the second configuration. That is, without the application of an external force, the support member  800  will occupy the second configuration. In one example, this is achieved by providing biased hinges  820  between adjacent segments. For example, one or more hinges may comprise a spring or other biasing mechanism to cause adjacent segments to rotate towards each other. For example, the biased hinge  820  may cause the second segment  814   b  to rotate in the direction of arrow  816 . In other examples, the spring or other biasing mechanism may be separate to the hinge. Some, or all, of the hinges may be biased. 
     To hold the support member  800  in the first configuration, an external force may be applied. For example, a device (not shown) may apply a force to the inner surface of the support member  800  at one or more locations. The device may be inserted into the hollow cavity  830  of the support member  800 . Arrow  828  in  FIG. 18A  shows the application of a force to the inner surface of the second segment  814   b  to hold the segment in abutment with the third segment  814   c . Due to the biased nature of the hinge  820 , removal of the device (and therefore the force) causes the second segment  814   b  to rotate in the direction of arrow  816 , and the support member moves towards the second configuration of  FIG. 18B . 
     In a particular example, the device is moveable along the first axis  802  to cause movement of the support member  800  between the first and second configurations. For example, when the support member  800  is in the first configuration, the device may located at a first position along the axis  802  within a hollow cavity  830  of the support member to hold the support member  800  in the first configuration, and when the support member  800  is in the second configuration, the device is located at a second position along the axis  802  different to the first position. 
       FIG. 19A  depicts a cross-sectional side view of an example support member  800  and a device  832  inserted into the hollow cavity  830  of the support member  800 . Here, the device  832  is located at a first position along the first axis  802 . In  FIG. 19A , the support member  800  is arranged in the first configuration and the device  830  is abutting an inner surface of the support member  800  to hold the support member  800  in the first configuration. 
       FIG. 19B  depicts the support member  800  at a later time, after the device  832  has been moved along the first axis  802  in a direction indicated by arrow  834 . The device  832  has been at least partially withdrawn from the hollow cavity  830  of the support member  800 , and is now located at a second position along the first axis  802 . In some examples the device  832  may be fully removed from the hollow cavity. 
     As shown, the device  832  has a tapered profile so that as the device  832  is moved in direction  834 , the wider portion of the device  832  is removed from the cavity, thus causing the cross-sectional width of the support member  800  to decrease until the support member  800  is in the second configuration. The support member  800  reconfigures because of the biased nature of the support member  800 . 
       FIG. 20  depicts a flow diagram of a method  900  for forming an aerosol provision device inductor coil. 
     The method comprises, in block  902 , providing a multi-strand wire  810  comprising a plurality of wire strands, wherein at least one of the plurality of wire strands comprises a bondable coating. As mentioned above, a bondable coating is a coating which surrounds the wire strand, and can be activated (such as via heating), so that the strands within the multi-strand wire bond to one more neighbouring strands. The bondable coating allows the multi-strand wire to be formed into the shape of an inductor coil on a support member, and after the bondable coating is activated, the multi-strand wire will retain its shape. The bondable coating therefore “sets” the shape of the inductor coil. 
     The method further comprises, in block  904 , winding the multi-strand wire around a support member  800  defining an axis  802 . For example, the multi-strand wire may be wound around the support member  800  in a helical fashion. 
     As the multi-strand wire  810  is being wound around the support member  800 , the method  900  further comprises, in block  906 , activating the bondable coating such that the multi-strand wire substantially retains a shape determined by the support member  800  (such as that provided by the channel  808 ). Alternatively, block  906  may occur after the multi-strand wire  810  has been fully wound around the support member  800 . 
     After the multi-strand wire has been wound, and after the bondable coating has been activated, the method further comprises, in block  908 , reducing a cross-sectional width of the support member in a direction perpendicular to the axis. Reducing the cross-sectional width of the support member may comprise causing the support member to move between a first configuration and a second configuration, wherein, when the support member is in the second configuration, the cross sectional width of the support member perpendicular to the axis is smaller than when the support member is in the first configuration. 
     After the cross-sectional width of the support member has been reduced, the method further comprises, in block  910 , removing the multi-strand wire from the support member. 
     The above embodiments are to be understood as illustrative examples of the invention. Further embodiments of the invention are envisaged. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.