Patent Publication Number: US-2022225665-A1

Title: A Device and a Method for Improving Aerosol Generation in an Electronic Cigarette

Description:
The present disclosure related generally to aerosol or vapor generating systems and devices, more particularly methods of controlling an aerosol or vapor generation with an aerosol-forming liquid which can be heated to produce an aerosol for inhalation by a user. 
     BACKGROUND ART 
     The use of aerosol generating systems, also known as e-cigarettes, e-cigs (EC), electronic nicotine delivery systems (ENDS), electronic non-nicotine delivery systems (ENNDS), electronic smoking devices (ESDs), personal vaporizers (PV), inhalation devices, vapes, which can be used as an alternative to conventional smoking articles such as lit-end cigarettes, cigars, and pipes, is becoming increasingly popular and widespread. The most commonly used e-cigarettes are usually battery powered and use a resistance heating element to heat and atomize a liquid containing nicotine (also known as e-cigarette liquid, e-cig liquids, e-liquid, juice, vapor juice, smoke juice, e-juice, e-fluid, vape oil), to produce a nicotine-containing condensation aerosol (often called vapor) which can be inhaled by a user. The aerosol can be inhaled through a mouthpiece, which, in the case of aerosols formed from e-liquids which contain nicotine, can result in delivery of nicotine to the lungs, throat and mouth, etc. of the user, and aerosol exhaled by the user generally mimics the appearance of smoke from a conventional smoking article. Although inhalation of the aerosol creates a physical sensation which is similar to conventional smoking, harmful chemicals such as carbon monoxide and tar need not be produced or inhaled in any significant quantities compared to combustible smoking products because there is no combustion. 
     In the conventional e-cigarettes described above, the liquid is put into contact through small channels to a resistance heating element where it is heated and vaporized, for example via a wick having a plurality of small channels that transport the liquid from a reservoir to the heating element. However, with conventional e-cigarettes, small amounts of unwanted chemical compounds, for example but not limited to aldehydes such as formaldehyde, are produced during the volatisation process for reasons which are not yet fully understood but are believed to be a result of localized burning of the e-liquid on the metallic heating element, and some of these are eluted into the condensation aerosol for inhalation and then impact negatively on the organoleptic properties of the inhalation aerosol. Additionally, problems can then arise with continued use of the e-cigarette, because deposits can be formed on the surface of the resistance heating element due to this localized “burning” of the liquid. This can reduce the efficiency of the resistance heating element. Furthermore, when the deposits are subsequently heated during operation of the e-cigarette, they can evaporate to create an unpleasant taste and/or generate harmful components in the resulting vapor/aerosol. These problems can be addressed by replacing the resistance heating element or the e-cigarette itself before there is a significant build-up of such deposits, but this involves unwanted expense and inconvenience for the user. Accordingly, the background art present a number of deficiencies and problems, for example the unwanted build-up of deposits, and the present disclosure seeks to address these difficulties. 
     SUMMARY 
     According to one aspect of the present invention, an aerosol generating device is provided. Preferably, the aerosol generating device includes a fluidic pathway that is in fluidic connection with a container holding an aerosol-forming liquid, a heating element that is in operative connection with the fluidic pathway, the heating element configured to heat the aerosol-forming liquid when inside the fluidic pathway to generate an aerosol, a power device for controlling power delivered to the heating element to control a heating power of the heating element, and a controller for controlling the power device to selectively make a first power delivery to the heating element to vaporize the aerosol-forming liquid before making a second power delivery to the heating element, wherein the first power delivery is at a value below the second power delivery. Preferably the controller is configured to control the power device to selectively make the first power delivery to the heating element to vaporize a portion of the aerosol-forming liquid to form a gas gap before making the second power delivery to the heating element, wherein the gas gap comprises an area of the fluidic pathway in contact with a heating surface of the heating element in which the aerosol-forming liquid has vaporised to form a gas. 
     Preferably the controller is configured to make the first power delivery at a beginning of an inhalation period by the user during a heater gas gap formation HGGF cycle, and after the HGGF cycle the controller is configured to make the second power delivery for a remaining time of the inhalation period. Preferably a duration of the HGGF cycle is configured to ascertain that a gas gap is formed in the fluidic pathway between the aerosol-forming liquid and a heating surface of the heating element. Preferably the HGGF cycle has a duration below 500 ms, or below 300 ms, or below 150 ms. 
     According to another aspect of the present invention, a method for controlling a power supply for an aerosol generating device is provided, wherein the aerosol generating device comprise a container, a fluidic pathway, a heating element in operative connection with the fluidic pathway, and a power device. Preferably, the method comprising the steps of detecting user inhalation of the aerosol generating device to determine an occurrence of an inhalation period, determining a power profile to be delivered to the heating element from the power device during the inhalation period, wherein the power profile defines selection of a first power delivery to the heating element to vaporize the aerosol-forming liquid before a second power delivery to the heating element, wherein the first power delivery is at a value below the second power delivery, and controlling the power device to make power delivery to the heating element based on the determined power profile. Preferably the power profile defines a selection of a first power delivery to the heating element to vaporize a portion of the aerosol-forming liquid to form a gas gap before a second power delivery to the heating element, wherein the gas gap comprises an area of the fluidic pathway in contact with a heating surface of the heating element in which the aerosol-forming liquid has vaporised to form a gas. 
     Preferably the first power delivery is made at a beginning of an inhalation period by the user during a heater gas gap formation HGGF cycle, and after the HGGF cycle the controller is configured to make the second power delivery for a remaining time of the inhalation period. Preferably a duration of the HGGF cycle is configured to ascertain that a gas gap is formed in the fluidic pathway between the aerosol-forming liquid and a heating surface of the heating element. Preferably the HGGF cycle has a duration below 500 ms, or below 300 ms, or below 150 ms. 
     According to still another aspect of the present invention, a cartridge for generating an aerosol is provided. Preferably, the cartridge includes a liquid container for holding an aerosol-forming liquid, a fluidic pathway that is in fluidic connection with the liquid container, a heating element that is in operative connection with the fluidic pathway, the heating element configured to heat the aerosol-forming liquid when inside the fluidic pathway to generate an aerosol, a memory storing data related to a power profile needed by the heating element to generate the aerosol, wherein the power profile defines selection of a first power delivery to the heating element to vaporize the aerosol-forming liquid before a second power delivery to the heating element, wherein the first power delivery is at a value below the second power delivery, and a controller for sending the data related to the power profile to an external device upon connection of the cartridge with the external device so that the external device can deliver power to the heating element of the cartridge based on the power profile. Preferably the power profile defines a selection of a first power delivery to the heating element to vaporize a portion of the aerosol-forming liquid to form a gas gap before a second power delivery to the heating element, wherein the gas gap comprises an area of the fluidic pathway in contact with a heating surface of the heating element in which the aerosol-forming liquid has vaporised to form a gas. 
     Preferably the first power delivery is made at a beginning of an inhalation period by the user during a heater gas gap formation HGGF cycle, and after the HGGF cycle the controller is configured to make the second power delivery for a remaining time of the inhalation period. Preferably a duration of the HGGF cycle is configured to ascertain that a gas gap is formed in the fluidic pathway between the aerosol-forming liquid and a heating surface of the heating element. Preferably the HGGF cycle has a duration below 500 ms, or below 300 ms, or below 150 ms. 
     The following configurations may additionally be provided. 
     Preferably, the gas gap can be considered as a separation between the aerosol forming liquid in the fluidic pathway and the heating surface of the heating element. 
     Preferably, the separation is defined by a region of the fluidic pathway adjacent to the heating surface in which the aerosol forming liquid has vaporised in the first power delivery. 
     Preferably, the separation is between substantially the entire heating surface and the fluidic pathway. 
     Preferably, the separation is formed by the generation of a gas by heating and vaporizing a portion of the aerosol forming liquid during the first power delivery, the portion inside the region of the fluidic pathway adjacent to the heating surface. 
     Preferably, the separation is configured to inhibit aerosol forming liquid in the fluidic pathway being in direct contact with the heating surface of the heating element during the second power delivery. 
     Preferably, the power device is configured to deliver power to the heating element during an inhalation period, the inhalation period comprising a pre-aerosol-delivery step and an aerosol-delivery step, and wherein the first power delivery is in the pre-aerosol-delivery step and the second power delivery is in the aerosol-delivery step. The inhalation period can also be referred to as a vaporization session. 
     Preferably, the pre-aerosol-delivery step is configured to vaporise the portion of the aerosol forming liquid inside the region of the fluidic pathway adjacent to the heating surface to create the gas gap before the aerosol-delivery step, and wherein the aerosol-delivery step is configured for a user to inhale the aerosol generated by the second power delivery. 
     Preferably, the pre-aerosol-delivery step is configured to take place before the user inhales upon the aerosol generating device. The pre-aerosol delivery step can be initiated by the user pressing a button to trigger the inhalation period. 
     Alternatively, the pre-aerosol-delivery step is configured to take place as the user begins to inhale upon the aerosol generating device. The pre-aerosol-delivery step can be initiated by a puff sensor that, for example, detects a pressure change when the user inhales upon the aerosol generating device to trigger the inhalation period. 
     The above and other objects, features and advantages of the present invention and the manner of realizing them will become more apparent, and the invention itself will best be understood from a study of the following description with reference to the attached drawings showing some preferred embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate the presently preferred embodiments of the invention, and together with the general description given above and the detailed description given below, serve to explain features of the invention. 
         FIG. 1  shows an exemplary schematic view of the aerosol generating device  100  having a heating element  30  for generating an aerosol  40  via a fluidic device  20  according to an aspect of the present invention; 
         FIG. 2  schematically and exemplarily shows an embodiment of the aerosol generating device  200  having a capillary wick  120  as the fluidic device, and a heating coil  130  wrapped around the capillary wick  120  for generating the aerosol  140 ; 
         FIGS. 3A-3C  illustrate problems related to the conventional way of heating for generating an aerosol, with  FIG. 3A  showing a side view and  FIG. 3B  showing a cross-sectional view of a heating device  30  and the fluidic device  20 , in the variant of a heating coil  130  and capillary wick  120 , and  FIG. 3C  showing a timely evaluation of a graph representing a temperature inside the fluidic device or at a surface of heating device  30  showing an excess temperature that leads to a burn zone BZ; 
         FIGS. 4A-4D  show aspects of the solution to the problem related to the generation of burned solid particles, with  FIG. 4A  showing a timely evaluation of a graph representing a temperature inside the fluidic device or at a surface of heating device  30 ,  FIGS. 4B and 4C  showing a cross-sectional views of a heating device  30  and the fluidic device  20  where a gas gap GG is present, in the variant of a heating coil  130  and capillary wick  120 , and  FIG. 4D  showing two graphs representing the application of different heating phases, including the heater gas gap formation cycle HGGF and the normal heating cycle NHC; 
         FIGS. 5A-5D  show different schematic and exemplary views of embodiments for the heating control device to establish the HGGF and NHC cycles with an aerosol generating device  100 ; 
         FIG. 6  shows an exemplary and schematic representation of an aerosol generating system, including a cartridge  400  that can be removably connected to a holder  500 , the cartridge  400  including a memory  471  for storing data on characteristics of cartridge, for example data that parametrizes the HGGF and/or the NHC cycles for the specific cartridge  400 ; and 
         FIG. 7  exemplarily shows two curves showing a timely evolution of a temperature of the heating device  30 ,  130 , and a heating power that is applied to heating device  30 ,  130 , to show a relationship between the power level of heating device and the temperature. 
     
    
    
     Herein, identical reference numerals are used, where possible, to designate identical elements that are common to the figures. Also, the images are simplified for illustration purposes and may not be depicted to scale. 
     DETAILED DESCRIPTION OF THE SEVERAL EMBODIMENTS 
       FIG. 1  depicts an exemplary schematic view of the aerosol generating system or device  100  with different elements in a symbolic representation, aerosol generating device  100  having a heating element  30  for generating an aerosol  40  via a fluidic element  20  according to an aspect of the present invention. An aerosol generating liquid  15  can be provided by a reservoir  10 , reservoir  10  being in fluidic connection with a fluidic element  20  to bring the aerosol generating liquid  15  to a transformation area TA of the fluidic element  20  where the aerosol generating liquid  15  can be transformed to an aerosol  40  by heating and vaporizing with heating element  30 . Fluidic element  20  can be a microfluidic device that has fluidic channels in a size and dimension that creates capillary motion or action on aerosol generating liquid  15 , so that the liquid  15  will move from reservoir  10  towards transformation area TA. In another variant, it is possible that reservoir  10  is a container that is under pressure to generate a motion of liquid  15  towards transformation area TA. A yet further variant provides a dosing mechanism for transferring a dose of liquid  15  from the reservoir to the transformation area for example by using a bubble jet ejection mechanism or a mechanical liquid transfer element, or other suitable mechanisms. Heating device  30  is in operative connection with a power device  60  that allows to change a heating power that is generated by heating device  30 , for example but not limited to a power switch or a power converter, and power device  60  is itself in operative connection with a controller  70 , for example but not limited to a microcontroller, microprocessor, data processor, electronic circuit, that allows to control the power device  60  to control heating device  30 , so that controller  70  can control power delivery to heating device  30 , and therefore a heating power generated by heating device  30 . A power storage device  80 , for example a rechargeable battery, is supplying electric power to power device  60  for providing the heating power. 
     With the heating of fluidic element  20  by heating element  30 , aerosol generating liquid  15  that enters by ingress ports of fluidic element  20  passes into or through transformation area TA of heating element  30 , for example by capillary action, and will be transformed into an aerosol  40  by vaporization at a boiling point, so that aerosol  40  egresses from egress ports of fluidic element  20 . Aerosol  40  is thereafter located in a vapor chamber  55  in proximity, in fluidic connection or at the mouthpiece  50 , before exiting the mouthpiece  44  to enter a mouth of a user. Reservoir  10  can be part of a removable cartridge (see  FIG. 6 ) or pod, that can be removably introduced to the e-cigarette. 
       FIG. 2  shows another exemplary schematic view of the aerosol generating device  200 . In the embodiment shown in  FIG. 2 , heating element  30  is formed by a heating coil  130  as a wire that is wound around a fluidic element  20 , in the variant shown a wick  120  forming a plurality of capillary fluidic channels. Other variants of the heating element  30  can be but are not limited to a resistive heating coil, an inductive heating coil, a heating plate, a capillary heating tube. Each end  122 ,  124  of wick  120  is arranged to be placed into or in fluidic connection with aerosol generating liquid  115 , for example directly with a fluid reservoir  110  or container, or indirectly by fluidic connections, so that wick  120  will be filled or otherwise provided with aerosol generating liquid  115 . This can be done by capillary action resulting from the dimensions and arrangement of the fluidic channels provided by wick  120 , to pull liquid  115  into wick  120  as indicated by the arrows in liquid  115  of  FIG. 2 . Wick  120  can be made of a bundle of fibers, bundle of hollow or porous tubes, or made of a porous solid, for example a ceramic material, or other fluidic device that allows to transport the aerosol generating liquid  115  from reservoir  120  to a transformation area TA where the wick  120  can be heated by heating coil  130 , for example with microchannels. Heating coil  130  is wound around wick  120  to form transformation area TA, where a surface of the wires that form heating coil  130  are in contact with wick  120 , such that wick  120  can be sufficiently heated to vaporize aerosol generating liquid  115  to generate aerosol  140  that will egress from wick  120  as indicated by the arrows pointing away from which  120  into vapor chamber  155  that is in fluidic connection with mouthpiece  150 . 
     Heating coil  130  is electrically connected by connection wires  132 ,  134  to a power device  160 , for example but not limited to a switch, a plurality of switches, a resistor different types of DC-DC converters such as a buck converter or a boost converter, or a combination thereof, or different types of current converters to control a current delivered to heating device  30 ,  130 , arranged to limit or control the power delivered to heating device  130 , and a power storage device  180 , for example a battery, that provides electric power to power device  160 . In this variant, the heating is performed by the resistivity of the conductive material that forms heating coil  130 , and by providing a certain voltage to connection wires  132 ,  132  with power device  160 , based on the resistivity of heating coil, a heating power is generated. Moreover, power device  160  can be controlled by a controller  170 , for example but not limited to a microprocessor, data processor, microcontroller, or other type of controller device, so that a power that is provided from power storage device  180  via power device  160  to heating coil  130  can be controlled based on data processing and of the controller  170 . A more detailed version of this embodiment of the aerosol generating device  200  as discussed in  FIG. 2  is shown in U.S. Patent Publication No. 2019/0046745 showing an exemplary heating coil  450  around a wick  440 ,  1440 , with its ends located in a chamber  270  containing a reservoir of liquid, the aerosol generating liquid  115 , this reference herewith incorporated by reference in its entirety. Another more detailed version of this embodiment can be seen in PCT publication with the Serial Number WO2017/176111, this reference herewith also incorporated by reference in its entirety, showing a wick  6 , a heating member  7 , fluid reservoir  8 , and liquid outlets  9 A,  9 B in fluidic connection with ends of wick  6 . 
     With certain heating coils  130  their relative thin diameter can be problematic, causing so-called hot spots along the heating wire that forms the heating coil  130 . Vaporization by heating device  30 , for example by heating coil  130  works well when heating coil  130  is made of a relatively thin wire to obtain a high power density, to create high heating power concentrated to a relatively small area. However, if the heating wires are too thin, other problems may arise. For example, the wire can become mechanically too fragile, thereby making it hard to safely and efficiently assemble the coil wick structure of heating coil  130 , and making it prone to failure due to tearing. Also, the reduced cross-sectional area will lead to less electric conductivity, and at sections with reduced cross-sectional area, for example pinch points or bends, the relative reduction of the cross-sectional area of a thinner wire will be much larger as compared to a wire with a larger cross-sectional area, leading to the generation of significant hot spots along the heating coil  130 , which are spots with a much higher temperature as compared to the average temperature of the wire that forms the heating coil  130 . Such hot spots are undesirable, as they can establish non-uniform heating of the transformation area TA of wick  120 , and this in turn can create heating temperatures that exceed a nominal or safe value. This in turn can create carbonyls from aerosol generating liquid  115 , which will adversely impact the taste of the inhalable aerosol  140 , and raising health issues. Furthermore in extreme cases, the excess temperatures of the thin spots can cause the wire of heating coil  130  to melt and break at those points if the wire is very thin. For heating coil  130 , wires are therefore chosen to have a diameter in a range between about 0.1 mm to 0.3 mm. 
     A specific problem with heating devices  30  and fluidic elements  20  associated therewith, for example with heating coil  130  having a transformation area TA that is exemplarily defined between the windings of the coil, with a wick  120  as the fluidic element  20 , for example wick  120 , located between the heating coil  130 , is illustrated with  FIG. 3A  and the cross-sectional view of  FIG. 3B , and the graph illustrated in  FIG. 3C  showing the evolution of the temperature at the heating coil  130 . Generally, transformation area TA can be at one or more locations in the vicinity of areas where the heating coil  130  is in contact with wick  120 . Usually, when electric power is delivered to the heating device  30  in an on/off fashion, either there is no electric power delivered to heating device  30 ,  130 , or a nominal power is delivered from a power source, for example battery  180 , to heating device  30 ,  130 . This causes a relatively rapid and strong heating of fluidic element  20 ,  120  by heating device  30 ,  130 , usually at a specific nominal power. With such an approach, which is relatively common amongst fairly simple e-cigarettes, when heating up the heating device  30 ,  130 , the heating temperature T of the heating coil will rapidly approach and then largely maintain a consistent operating temperature at which vaporization is ample. At this operating temperature, any fluctuations in the power applied to the heating coil tend to result in corresponding fluctuations in the amount of vaporization occurring rather than in (significant) variations in the (average) temperature of the heating coil since most of the heat energy from the heating coil is used to supply the latent heat of vaporization of the e-liquid necessary for it to vaporize. 
     More sophisticated heating coil temperature control schemes may be employed in more sophisticated e-cigarettes. For example, some e-cigarettes employ a Proportional Integral Derivative (PID), or sometimes, by setting the Integral component to 0, a Proportional Derivative (PD), negative feedback loop temperature control system to accurately maintain the (average) temperature of the coil at a desired target temperature. Such e-cigarettes typically employ a metallic heating coil made of a metal such as stainless steel or titanium which have a non-negligible temperature coefficient of resistivity such that the average temperature of the heating coil can be estimated based on a measurement of the resistance of the heating coil. As is well known, control systems operating on a negative feedback temperature control system typically overshoot the target temperature, for example the vaporization temperature VT of liquid  15 ,  115 , especially where the ramp up time is short. This temperature overshoot of the desired temperature VT is a result of heating device  30 ,  130  trying to ramp up the temperature as fast as possible. This leads to a temperature overshoot over a specific threshold temperature TT within the fluidic element  20 ,  120  to which the liquid  15 ,  115  is exposed, and will cause an overheating of liquid  15 ,  115 , labelled in  FIG. 3C , in a burn zone BZ. The overheating of aerosol generating liquid  15 ,  115  beyond threshold temperature TT in this burn zone BZ can additionally create the decomposition of aerosol generating liquid  15 ,  115 , to burn liquid  15 ,  115  creating burnt or decomposed material or solid residual particles, instead of properly vaporizing liquid  15 ,  115 , in addition to that which may be caused simply by virtue of the rapid temperature rise prior to and during the formation of the gas gap. Moreover, the accumulation of burnt or decomposed material in proximity of a heating surface of heating coil  130  can create a deposition of this material onto the heating surface, and can participate in the generation of additional carbonyls in the aerosol  40 ,  140 . Also, this can lead to oxidation of the coil of heating device  30 ,  130 , deteriorating device performance and life time duration. 
     For aerosol generating devices having a close-loop (negative feedback loop) temperature control system to avoid overheating of heating device  30 ,  130 , and to avoid the decomposition of the liquid  15 ,  115 , the temperature control system typically acts on the voltage Vout that is provided to heating device  30 ,  130 . Usually the time constant as a response time or cycle time of a temperature control system is in the 100 ms to 150 ms range, which means that once a temperature error occurs, it will take some time above 100 ms to control the temperature to the correct desired temperature. Unfortunately, this control cycle and its time constant is too slow as compared to the fast ramp-up of the temperature to reach VT, and will not be able to prevent a temperature overshoot to pass over threshold temperature TT, and the resulting establishment of the burn zone BZ. Moreover, even if the temperature control system has a faster response time or cycle time, such PID close-loop control systems are typically arranged to control the system to rapidly approach and then maintain a target temperature, but are less suited to achieving a specified ramp-up profile. In other words, they “try” to ramp up the controlled variable (i.e. in this case the measured temperature of the heating coil) as quickly as possible. In addition, for many aerosol generating devices  100 , especially during ramp up when the system has not yet reached a steady state, the relationship between the heating coil temperature and the temperature of e-liquid which is being vaporised may be complex and unpredictable meaning that the temperature of the heating coil may not be a useful measure of the temperature of the e-liquid being heated, which leads also to additional difficulties to properly control the temperature of the e-liquid close to the heating coil when simply relying on a close-loop control system based on heater coil temperature, especially during the critical ramp-up phase. 
     Moreover, even in the event that a control scheme is employed which prevents the occurrence of hot spots or temperature overshoots beyond the desired target temperature during temperature ramp up, it is believed that there may also be problems associated with on overly fast ramp up of temperature for reasons explained below. In particular, and without wishing to be overly bound by theory, until a steady state vaporization state is reached, liquid may be in direct contact with a heating element, and at a temperature which is sufficient to burn the liquid whilst it is in direct contact with the heating element, even when that temperature is not such as to burn the liquid when it is protected by a vapour gap, and, indeed, even when that same temperature is an optimum or good temperature for vaporizing the liquid when such a vapor gap has been established. 
     A solution to this problem is herein proposed, by the use of the proposed device, system and method, where a heater gas gap formation cycle or period HGGF is used, in which the heating device  30 ,  130 , when initiating the heating phase HP, is first heated with a reduced amount of power, as compared to the nominal heating power, to somewhat increase the ramp-up time, but at the same time avoiding or substantially reducing undesirable chemical formation during the ramp up phase, as illustrated in  FIG. 4A . The HGGF period is preferably designed such that there is sufficient time for all e-liquid directly contacting the heating coil to vaporize away from the surface of the heating coil  130  before reaching a temperature at which chemical reactions could occur resulting in the formation of undesirable complex chemicals such as aldehydes and carbonyls etc. Once the heater gas gap has been formed it is considered safe for the heating coil temperature to rise above the temperature at which the gas gap forms since in this case there is no e-liquid directly touching the hot heating coil any more and rather e-liquid is vaporized in a non-burning manner prior to touching the heating coil. Thereafter, the heating device  30 ,  130  can thus be operated at nominal heating power in the normal heating cycle NHC. This strategy can substantially reduce or even eliminate the formation of undesirable complex chemicals such as aldehydes, carbonyls etc. that are generated when using conventional heating strategies. This can substantially reduce the creation of the carbonyls in the inhalable condensation aerosol produced and can also reduce oxidation of the coil of heating device  30 ,  130 , increasing the lifetime of heating device  30 ,  130 . 
     Usually, when electric power is delivered to the heating device  30 ,  130 , areas of the fluidic element  20 ,  120  in close proximity to a heating surface of heating device  30 ,  130  receive more heating power than areas of the fluidic element  20 ,  120  that are more remote to a heating surface of heating device  30 . In other words, there is a delay of the heating between areas close to heating device  30 ,  130  in fluidic element  20 ,  120 , as compared to areas that are more remote to heating device  30 ,  130 . This is due to thermal capacity and thermal insulation provided by fluidic element  20 ,  120 , and also a propagation time provided by the fluidic element  20 ,  120  for distributing or otherwise providing aerosol generating liquid  15 ,  115 , therein, for example by soaking the wick  120  with the aerosol generating liquid  15 . 
     This effect results in the reaching of a vaporizing temperature VT of aerosol generating liquid  15 ,  115  within the fluidic element  20 ,  120  at a first time t 1  for areas close to a heating surface of heating device  30 ,  130  that is in operative engagement with fluidic element  20 ,  120 , while reaching a vaporizing temperature VT of aerosol generating liquid  15 ,  115  at a second, later time t 2  for areas farther to the heating surface of heating device  30 ,  130 . As a result, aerosol generating liquid  15 ,  115  is vaporized selectively at areas that are closer to heating device  30 ,  130 , leading to areas within the body of fluidic element  20 ,  120  where aerosol generating liquid  15 ,  115  is vaporized and is present in gas form, as vapor  40 ,  140 .  FIG. 3B  shows a cross-sectional view of heating coil  130  and wick  120  where wick is entirely soaked through with aerosol generating liquid  15 ,  115 , for example the one shown with a side view in  FIG. 3A , prior to and thereafter, in  FIG. 4B , a certain first time period after the heating by heating coil  130  has been activated or turned on, it is shown that only an inner core of wick  120  is soaked with aerosol generating liquid  15 ,  115 , while an annular region with a certain close distance or radius to a surface of heating coil  130  does not have any liquid anymore due to vaporization of the adjacent e-liquid. 
     Instead, the region or volume contains the aerosol generating liquid  15 ,  115  in gas form, being vapor  40 ,  140 , illustrated by a lighter shading of the cross-sectional view, to form a so-called gas gap GG between heater and liquid-drenched or liquid-containing fluidic element  20 ,  120 . Next, as exemplarily shown in  FIG. 4C , a certain second time period after the first time period, while heating by heating coil  130  is still active during the ramp-up phase, even a smaller circle of the inner core of wick  120  is soaked with aerosol generating liquid  15 ,  115 , due to a vaporizing temperature VT reaching a more remote area to heating coil  130 . At this stage the gas gap GG has been fully formed and the system reaches a more steady state of operation. 
     This effect is influenced by a slower heat transfer of the heat inside gas, e.g. gas gap GG, formed by evaporated liquid as compared to the heat transfer provided by liquid  15 ,  115 , such that once a surface area of fluidic element  20 ,  120  in contact with a heating surface of heater device  30 ,  130  is devoid of aerosol generating liquid  15 ,  115  and has transformed to gas  40 ,  140  by evaporation to form gas gap GG, the heat transfer is further diminished. This phenomenon is comparable or similar to the Leidenfrost effect, being a physical phenomenon in which a liquid, for example liquid  15 ,  115 , close to a heating mass, in this case a surface of heater device  30 ,  130  that is significantly hotter than the vaporization temperature of the liquid  15 ,  115 , produces an insulating vapor layer that keeps the liquid  15 ,  115  from boiling or vaporizing rapidly. This establishes a repulsive force that suspends the remaining liquid  15 ,  115  away from the heating mass against gravity, for example to a droplet, preventing any further direct contact between the liquid  15 ,  115  and the heater device  30 ,  130 . In the present situation, the gravity effect can be compared to the capillary suction effect of fluidic element  20 ,  120 , for example by the wick, that acts against a pressure build up by the gas gap GG or gas layer. 
     Simultaneously, aerosol generating liquid  15 ,  115  is passively redistributed within the body of fluidic element  20 ,  120 , for example by capillary action, soaking, or refilling within wick, and cannot replenish the areas or volumes that are devoid of aerosol generating liquid  15 ,  115  fast enough to provide continuity of the presence of aerosol generating liquid  15 ,  115  throughout fluidic element  20 ,  120 , especially when heated at nominal power. Generally, when the heater device  30 ,  130  is being provided nominal heating power, a time required to evaporate a certain area or volume by evaporation of fluidic element  20 ,  120  to form the gas gap GG is much shorter than a time required to replenish the same area or volume by capillary action with fluidic element  20 ,  120 . 
     The controlling of the heating power by the two cycles, first the heater gas gap formation cycle HGGF and the thereafter the normal heating cycle NHC take advantage of the effect that is provided by the gas gap GG. A duration of the HGGF is designed such that the gas gap GG is established before the heater is switched to the more powerful normal heating cycle NHC, to avoid e-liquid in contact with the heating coil from being heated to temperatures above the vaporization temperature at which complex chemical reactions can occur resulting in the generation of unwanted chemicals before the gas gap GG is formed. It will be appreciated that at the boundary between the liquid layer and the gas gap the temperature may be significantly lower than at the heating coil surface. In fact, the temperature at the interface between liquid and gas/vapour will of course be the vaporization temperature of the e-liquid and a non-flat interface can be neatly accommodated with little risk of e-liquid in the liquid phase touching the heating coil surface. This is believed to further mitigate against the formation of undesirable chemicals etc. In this respect, heating device  30 ,  130  is controlled to operate on a two-phase or two-cycle system. With this two-phase operation, heater gas gap formation cycle HGGF is selectively performed to make sure the gas gap GG is established inside the fluidic element  20 ,  120 , where liquid  15 ,  115  will form a gas phase by gas gap GG and a liquid phase LP. Thereafter, the normal heating cycle NHC is performed, to take advantage of the insulating effect of the gas gap GG, so that the threshold temperature TT does not reach the liquid phase LP in the fluidic element  20 ,  120 . In this respect, even if a heating surface of heating device  30 ,  130  is above the threshold temperature TT, due to the thermal insulation effect of the gas gap GG, based on the Leidenfrost effect, a temperature at the liquid phase LP will be below the threshold temperature TT, but still above the vaporization temperature VT. 
     Accordingly, with the above discussed control principles using a first power delivery to the heating element to vaporize the aerosol-forming liquid before making a second power delivery to the heating element, the first power delivery is at a value below the second power delivery, one goal is to limit or eliminate the generation of degraded by-products of aerosol generating liquid  15 ,  115  by avoiding to burn molecules of aerosol generating liquid  15 ,  115  during the heating phase. In addition, it is also a goal to provide for a controlled heating of heating device  30 ,  130 , such that during a first cycle of the heating phase, being a heater gas gap formation cycle HGGF, a gas gap GG is formed inside fluidic element  20 ,  120 , before a second heating phase is initiated in which a higher heating power is used, during a normal heating cycle NHC. Preferably, the gas gap GG established in the fluidic element  20 ,  120  is such that no liquid  15 ,  115  is in direct contact with any surface of the heating device  30 ,  130 , as a partial contact of liquid  15 ,  115  with surfaces of heating device  30 ,  130  in the transformation zone TZ could lead to the creation of solid burnt or decomposed elements, the undesired by-product. This approach of first heating with a lower heating power for the temperature ramp-up in the heater gas gap formation cycle HGGF as compared to the higher heating power used in the subsequent normal heating cycle NHC is counter-intuitive and somewhat surprising in this field, as in the state of the art, the heaters are heated first with a larger power to provide for a very fast ready time of the device. 
     According to an aspect, a device, system, or method is provided, where the heating cycle of aerosol generating liquid  15 ,  115  by heating device  20 ,  120  is split into two temporal stages or cycles, instead of using a simple on/off heating at nominal heating power and an optional temperature control during the entire heating cycle. First, with a first heating cycle, a heater gas gap formation cycle HGGF is performed that establishes a gas gap GG in the fluidic element  20 ,  120 , and thereafter, once the gas gap GG is present, a second heating cycle NHC is performed, at a higher heating power than the HGGF. The HGGF cycle can have a duration that is below 500 ms, preferably below 300 ms, or more preferably below 150 ms, and can start with the user taking a puff or making an inhalation, while the heating device  20 ,  120  is still cold. 
       FIG. 4C  shows another aspect, in which different heating cycles are shown, four (4) of them having a first HGGF cycle, and two (2) having no HGGF cycle. If a second subsequent heating cycle HC 2  is started within a certain time period TP of an end time of a first heating cycle HC 2 , it may not be necessary to start the second heating cycle HC 2  with a HGGF. This is shown in the upper graph representation of  FIG. 4C , where a heating cycle HC 2  with no HGGF follows a first heating cycle HC 1 . This is due to the fact that the fluidic element  20 ,  120  and its capillary channels did not have enough time to be fully filled and soaked liquid  15 ,  115  in which case the liquid phase LP is again in contact with a surface of heating device  30 ,  130  after the first heating cycle HC 1  where the gas gap GG was formed. This means that before a certain time period (a threshold idle time TIT which is sufficiently long enough to cool down the heater and also the vaporized gas such that the gas gap GG can be completely eliminated) is over, the next heating cycle HC 2  is started, and the gas gap GG (already formed in first heating cycle HC 1 ) will still be present in the fluidic element  20 ,  120  as illustrated in  FIG. 4C , and hence there is no need to create a new gas gap GG. This means next heating cycle HC  2  can directly be started with the normal heating cycle NHC. Exemplarily, the TIT can be 1 second or more, depending on the characteristics of the fluidic element  20 ,  120 , for example material used, porosity, diameter, and also depending on characteristics of the heating element  30 ,  130 . 
     In contrast, as shown in the lower graph representation of  FIG. 4C , a fourth heating cycle HC 4  is started after a certain time period has revolved that is longer than the threshold idle time TIT, after an end of the third heating cycle HC 3 , so that the gas gap GG does not exist anymore, which means that fluidic element  20 ,  120  have had the time to be fully filled with liquid  15 ,  115  again. In such case, fourth heating cycle HC 4  needs to be started with a heater gas gap formation cycle HGGF to re-establish the gas gap GG in the fluidic element  20 ,  120 , to avoid excessive temperatures over the TT temperate in the heating coil which is very likely to cause chemical reaction forming undesired chemical compounds. 
     The timing of the heating cycles can be controlled by a timer that is programmed to controller  70 , with a timing counter that counts a time revolved after an end of precedent heating cycle, so that upon staring of a new heating cycle, for example by detecting the user taking a puff or inhaling, it can be verified whether the threshold idle time TIT has been revolved, to see if a heater gas gap formation cycle HGGF is necessary. The end and the beginning of the heating cycle, whether with or without the HGGF, can be determined by a puff sensor  174  that can automatically provide a signal to controller  170  when a puff is made by user via mouthpiece  150 , or can also be determined by the user manually pressing a button  176  that provides a signal to controller  170 . The threshold idle time TIT can be a constant, but can also be calculated based on different parameters measured from aerosol generating device  100 , for example but not limited to a duration of the preceding heating cycle, an average temperature caused by the heating device  30 ,  130 , a fill level of the aerosol generating liquid  15 ,  115  in container  10 ,  110 , an average heating energy consumed by the preceding heating cycle. 
     With respect to the difference between the first heating power and the second heating power, and their absolute values, these values are determined based on the materials, dimensions, and characteristics of aerosol generating device  100 . Generally speaking, in terms of absolute value of heating power, the first heating power needs to be lower than the second heating power, but still above a certain absolute power threshold to have sufficient power to vaporize the liquid  15 ,  115  within a relatively short amount of time, this time being the HGGF cycle and, the HGGF cycle preferably being less than 500 ms, preferably below 300 ms, or more preferably below 150 ms. In this respect, the HGGF cycle chosen to be short enough that it is barely noticeable by the user, and therefore does not impact the user experience and timing of the desired inhaling. 
     In terms of relative ratio between the first heating power and second heating power, the first heating power can also be in the range of 20%-80% of reduction relative to the second heating power, as long as the evaporation of liquid  15 ,  115  occurs within the above-discussed duration of the HGGF cycle, more preferably the range of 50%-80%, more preferably 60%-80%. As a non-limiting example, if power device  80  is a Li-Ion battery having an output voltage of 3.6V, and the voltage is controlled internally to a value of 3.3V, this voltage being applied during the NHC cycle by power device  60  to heating device  30 ,  130 , and the coil resistance of heating device  30 ,  130  is between 1.5 Ohm and 2 Ohm, with the equation that electrical power being the voltage in square divided by the resistance, the second heating power can be between 5.445 W to 7.26 W, while the first heating power can be for example around 50% of that value, being between 2 W and 4 W. However, there are also aerosol generating device  100  with much higher heating powers, e.g. with nominal heating powers up to 200 W and more. 
     With lower resistive values of the coil for heating device  30 ,  130 , for example at sub-ohm resistance, e.g. 0.8 Ohm, the power reduction between first power delivery and the second power delivery, can be more than the indicate value of 50% discussed above. For example, the nominal power with 3.3V could be about 13 Watts and the ramp up voltage would likely be within about 20% and 50% of this nominal power, i.e. between 2.7 Watts and 7.5 Watts. As another non-limiting example, if aerosol generating device  100  is a mod tank device providing up to about 200 Watts and having a sub-ohm resistance of heater coil at about 0.8 Ohms, and having a 12V power source making the nominal power delivery 180 Watts or more, presumably the ramp up power could conceivably be as low as 5% of the nominal power, i.e. lower than 10 Watts. 
       FIG. 5A  shows an embodiment of the power control device  260  that is integrated or otherwise a part or inoperative connection with an aerosol generating device  100 , to operate the heating device  30 ,  130  at the heater gas gap formation cycle HGGF and thereafter at the normal heating cycle NHC. A controller  70 ,  170 , for example a microcontroller or other type of data processor, can control two switches  261 ,  262  that are arranged in parallel to provide for two different electric circuits that can deliver either the nominal power of the NHC via switch  262 , or can deliver the reduced power as compared to the nominal power of the HGGF via switch  261 . Specifically, voltage of power source  80 ,  180  and resistance value of the coil of heater device  130  are designed such, when switch  262  is in the on state and switch  261  is in the off state, controlled by controller  70 ,  170 , the nominal power is delivered via switch  262  to heater  130  to provide for heating power in the NHC cycle. In turn, voltage of power source  80 ,  180  and resistance value of the coil of heater device  130  in addition with resistance value of resistor  265  are designed such, when switch  261  is in the on state and switch  262  is in the off state, controlled by microcontroller  70 ,  170 , the reduced power is delivered to heater  130  to provide for the reduced heating power in the HGGF cycle. 
     This embodiment allows to make only minor variations to an existing heater  130  device, by adding an additional electric circuit or path to provide for the reduced power via an additional resistor  265 . In idle mode, for example when the user is not inhaling or is not taking a puff, switches  261 ,  262  are controlled to be off by controller  70 ,  170 , or are off by default. Then, when a user takes a puff or inhales, for example by detection with a puff sensor  174  or button  176 , the HGGF cycle can be activated by putting switch  261  on, for example during a period of approximatively 100 ms to 300 ms, where the current is limited by the resistive value of resistor  265  and the resistive value of heater  130 . Next, when the heater  130  has been heated enough, switch  261  is turned off, and switch  262  is turned on for nominal power operation with NHC cycle. It is also possible that switch  262  not operated in a steady on-state during the provision of the nominal heating power with the NHC cycle, but is switched with a pulse-width modulation pattern (“PWM”), controlled by controller  70 ,  170 , for example with a temperature measurement feedback from temperature sensor  138 , to stabilize the temperature by a control algorithm to perform a closed-loop temperature control, for example but not limited to a P, PI or PID control algorithm. 
       FIG. 5B  shows another embodiment of the power control device  360  that is integrated or otherwise a part or inoperative connection with an aerosol generating device  100 , to operate the heating device  30 ,  130  with the heater gas gap formation cycle HGGF and thereafter the normal heating cycle NHC. Similar to the embodiment of  FIG. 5A , a microcontroller  70 ,  170  or other type of data processor can control two switches  261 ,  262  that are arranged in parallel to provide for two different electric circuits for providing the normal or nominal heating power for NHC via switch  262  or for providing reduced heating power of the HGGF via switch  261 . Instead of a resistor or resistive element  265 , an inductive element  365  is provided in the path or circuit of switch  261  for the HGGF. The indicative element  365  can also have a resistive component that allows to reduce the stationary HGGF cycle heating power. The inductive element  365  can have an inductance L that is configured to reduce an inrush current to avoid large current spikes that could cause the temperature to of heater device  30 ,  130  rise during the HGGF cycle, to cause the burn zone BZ. 
       FIG. 5C  shows a variant where the inductive element  365  and the coil formed by the heating device  130  are combined to form a single coil, with inductive element  365  having a ferromagnetic inductor core  367  with the appropriate dimensions and coil winding number to provide for the desired inductance L, and at the same time coil of heating device  130  being wound around the fluidic element  120  as a wick. Between the inductive element  365  and the heater coil of heater device  130 , an electric connection is made to connect to switch  262  for the normal heating cycle NHC heating power delivery. The combination of the inductive element  365  and the coil that forms heater device  130  can reduce device failure as it reduced the number of components, and can also provide for advantages of electromagnetic compatibility, as compared to the use of a separate inductive element. For example, a ferrite core for inductive element  365  can be placed within the wick  120 , and the coil of heating element can be wound around wick  120  where the coil is located, so that coil forms the heating device  130  and the inductive element with the same components. 
       FIG. 5D  shows another embodiment of the power control device  360  that is integrated or otherwise a part or inoperative connection with an aerosol generating device  100 , to operate the heating device  30 ,  130  with the heater gas gap formation cycle HGGF and thereafter the normal heating cycle NHC, where a DC-DC converter  462  is used to control the heating power that is delivered to heating device  30 ,  130 . For example, DC-DC converter  462  could be a boost generator with a controllable voltage output at Vout, having an input voltage Vin from the battery  80 ,  180 , based on a setting that is provided by controller  70 ,  170 . Therefore, only one circuit or path can be provided for heater gas gap formation cycle HGGF and normal heating cycle NHC, both heating powers given by a voltage output Vout of the DC-DC converter  462 . Moreover, a power filter  464  can be optionally provided in the power or electric line that leads to heating device  30 ,  130 , to filter out undesired voltage peaks or current peaks. For example, DC-DC converter  462  can be operated with PWM modulation, to have a small duty ratio during the period where the reduced power of the heater gas gap formation cycle HGGF is provided, for example but not limited to the range varying between 5% and 30%, and can have a larger duty ratio during the period where the nominal power of the normal heating cycle NHC is provided, for example but not limited to the range varying between 50% and 100%. A voltage sensor  139  can be arranged to measure the voltage at the heating device  130 , or at the output of DC-DC converter  462  for closed-loop voltage control, which can be combined with a closed-loop temperature control. 
     The PWM control scheme can also be used for the embodiments in  FIGS. 5A and 5B , performed by microcontroller  70 ,  170 , so that the electric power that is delivered to heater  130  can be selectively controlled, and not only determined by resistor  265  or inductor  365 . 
     For example, during the heater gas gap formation cycle HGGF, the Vout can be steadily increased to reach a desired temperature for the normal heating cycle NHC, where it can be certain that the gas gap GG has been formed. As explained above, the voltage ramp-up can be controlled by PWM modulation, or by the aid of characteristics of filter  464  that allows to filter the power delivered to heating device or heater  30 ,  130 , for example a filter having mostly capacitive characteristics. Also, a switch  461  can be provided to cut any power delivery to heater  30 ,  130 . In a variant, instead of having resistor  265  ( FIG. 5A ) or inductive element  365  ( FIG. 5B ), this part of the electric circuit could be equipped with the DC-DC converter  462  to provide for controllable and reduced power to the heating device  30 ,  130  in the heater gas gap formation cycle HGGF. 
     According to another aspect of the present invention, a cartridge, pod, or other type of consumable for holding and vaporizing the liquid  15 ,  115  is provided, having a memory  371  therein or otherwise associated therewith, for storing different parameters that characterize the cartridge  400  related to the heating, specifically parameters related to the control and performance the heater gas gap formation cycle HGGF, and this data can be sent from cartridge  400  to holder  500 . A schematic and exemplary view of such cartridge  400  is shown in  FIG. 6 , being a cartridge  400  that can be a one-time use and disposable cartridge, a reusable or refillable cartridge, or an element that can be integrated or is an integral element of different types of aerosol generating devices. Cartridge  400  can be removably or fixedly connected to a holder  500 , for example by a mechanical snap-on, clip-on, push-on, quick-release, threading, locking, bayonet mount connecting, complementary mating, press-fit connection, or other type of reversible attachment mechanisms, to form a complete aerosol generating system. In context of  FIG. 6 , the aerosol is generated from liquid  115  in cartridge  400  with heating device  130 , and holder  500  includes a data processor or controller  170 , power device  160  for controlling the electric power from battery  180 , these elements previously described as elements integrated to aerosol generating device  200  of  FIG. 2 . 
     Holder  500  can have a longitudinal shape for being held by a user or operator for inhalation, and can have a power supply therein, for example a rechargeable battery  180 . In the variant shown, cartridge  400  can include a casing  410 , an inhalation channel  450  that can form a mouthpiece or can fluidically be connected to a mouthpiece, an aerosol generating chamber  455 , a liquid containing chamber  115 , for example a fixedly sealed or refillable one via a refilling port, a fluidic element  120  such as a wick, forming a fluidic pathway from liquid chamber or fluidic reservoir  411  to aerosol generating chamber  455 , a heating device  130  for example a heating coil or other type of heating device in operative connection with wick  120 , power cables  434  that are electrically connected to wick  120  at one end, and connected to electric terminals  412  at the other end, the terminals  412  arranged to connect with an external device, for example to power device  160  of holder  500 . Terminals  412  and power cables  434  are configured to be fed with electrical power from an external device, for example holder  500 , for example via corresponding terminals  512  that are in electric contact with a power device  160 . Terminals  512  are arranged to be in electric contact with terminals  412  of cartridge  400  when holder  500  is connected to cartridge. In a variant, only two terminals  412 ,  512  are present, with no need for additional terminals  413 ,  513 , to minimize the number of electric connections, and the controller  470  is configured to modulate the data of the parameters onto the power cables or wires  434 , and controller  170  is configured to demodulate the data of the parameters at holder  500 , to control power device  160 . 
     Moreover, cartridge  400  can further include a data processing device  470 , for example but not limited to a microcontroller, microprocessor, or other type of device that can access data from a memory  471  and send this data to an external device, for example holder  500 , and memory  471 , for example non-volatile memory or permanent memory for storing parameters related to the specific ramp-up heating, for example data related to the heater gas gap formation cycle HGGF. 
     In this respect, the cartridge  400  can be referred to as a smart or intelligent cartridge. This data includes the parameters that allows to perform the first power delivery from holder  500  to cartridge  400 , but also can include data to perform the second power delivery from holder  500  to cartridge  400 . Memory  471  can also be internal memory to data processing device  470 . Data processing device  470  is operatively connected with terminals  413  that are arranged to connect or otherwise communicate with an external device, for example via corresponding terminals  513  of holder  500 , that are in communicative connection with a controller  170  of holder  500 , to exchange data when cartridge  400  is connected to holder  500 . In a variant, cartridge  400  is equipped with a wireless communication port, and can communicate via wireless communication port to holder  500 , to transmit data related to the parameters stored in memory  471 . 
     With respect to the data of parameters that can be stored in memory  471 , the data can represent the parameters required to properly perform the HGGF with a configuration given by the specific cartridge  400 , and its heating and fluidic device  130 ,  120 . For example this data can include but is not limited to data that represents the duration of the HGGF cycle for the given cartridge  400 , data that represents the threshold idle time, data that represents the power supply level of the HGGF cycle, for performing the first power delivery by holder  500  to cartridge, and data that represents the power supply level during the NHC cycle, for performing the second power delivery. Generally, the parameters that characterize the HGGF cycle, where the first power delivery is performed, and also the NHC cycle, where the second power delivery is performed, strongly depend on the configuration of the heating device  130 , for example the geometry of heating coil, including wire cross-sectional area, inductance of coil, number of windings, surface area formed by a winding, overall length of wire forming coil, and can also depend on the type of fluidic device  120  of cartridge  400 , for example the type of wick, for example but not limited to a length of wick  120 , length or dimensions of the transformation area TA, characteristics of the porosity or microchannels. 
     Therefore, these parameters are highly dependent on properties and arrangement of heating device  130  and fluidic device  120  and their arrangement with cartridge  400 , and different types of cartridges  400  may be removably or fixedly mated with holder  500 , to form an aerosol generating system  500 . For this reason, preferably, data of these parameters are stored within memory  471  of cartridge  400  itself, and upon connection of cartridge  400  with holder  500 , this data can be communicated or otherwise transmitted or made available to holder  500 , for example for controlling power controller  160  to selectively generate the HGGF cycle in cartridge  400 . The system with cartridge  400  and holder  500  of  FIG. 6  is only exemplary, and the data of the parameters can be incorporated in different types of liquid cartridges that are equipped with a data processing device and memory, for example the one described in U.S. Patent Publication No. 2017/0035115, this reference herewith incorporated by reference in its entirety. 
     For example, memory  471  can store data that indicates or is representative of a resistance of heating element  130  that is present in cartridge  400 , so that power delivery calculations as discussed supra can be done by holder  500  by controller  170  and power device  160  accordingly. Other data that can be stored is data that is representative or otherwise indicative of a power ratio between first power delivery and second power delivery cycles, data that includes information on the identification of the heating element  130  and its design parameters, including but not limited to diameter, length, volume, average cross-sectional area, porosity of heating element  130 . Basically, memory  471  can store data that allows to characterize the cartridge  400  and its elements for properly generating the HGGF and NHC cycles for the specific parameters. This can allow holder  50  to read data or otherwise receive data from cartridge  400  via terminals  413 ,  513 , or alternatively by a wireless connection, such that the HGGF and NHC cycles can be readily calculated or generated by controller  170  and power device  160 , powering the heating device  130 . 
       FIG. 7  shows two curves showing a timely evolution of a temperature of the heating device  30 ,  130  with the upper curve, and a heating power that is applied to heating device  30 ,  130  with the lower curve, to show a relationship between the power level of heating device and the temperature. For simplification and illustration purposes, the temperature is shown with straight lines, but in reality, the temperature curve would not have fully linear sections as shown. 
     During the time of 0−T 1 , for example a duration of 50 ms, battery  80  can provide a first power delivery P 1  to the heater  30 ,  130  controlled by power device  60  and in this case heating elements of the heater  30 ,  130  heat up relatively slowly, until we are relatively confident that a gas gap GG has been formed after which the power delivery is increased to the second power delivery P 2 . This phase (when the first power delivery P 1  is provided) is referred to as the HGGF cycle. Prior to the point to increase power delivery from P 1  to P 2 , there is a period during which vaporization starts occurring. This period straddles a temperature range able to vaporize chemical liquids within liquid  15 , and such vaporization period is when the gas gap GG is formed. The vaporization temperature is a range because some chemical content has lower boiling temperature whilst others can have higher boiling temperature and because vaporization is a gradual process which starts a little below the boiling point in any event according to the laws of statistical thermodynamics. After the gas gap GG is formed (i.e., after the gas gap formation cycle HGGF has passed), power from battery  80  is controlled to increase the power to the heater  30 ,  130  with a second power delivery P 2 , and at that point the temperature of heater will ramp up rapidly towards target temperature for steady state operation and then will stabilize at a nominal power delivery which is typically about 80% of the max power applied for the final ramp up section, during the NHC cycle. In reality, power delivered to heater  30 ,  130  will typically reduce and then fluctuate up and down a bit once the heater has reached the target temperature as the feedback loop control kicks in to maintain the heater at the target temperature. Such feedback loop control method can be either classic control methods (e.g., PID, PI), or other advanced techniques to control temperature of heater. However, this part is not illustrated in  FIG. 7  for simplification purposes, and a dashed line at the tail of the power line is shown for illustration purposes. Therefore, fluctuations and actual shape of the temperature graph of  FIG. 7  are not fully represented and simplified for illustration purposes. 
     In sum, according to some aspects and some embodiments of the present invention, an initial ramp up power delivery profile referred to as HGGF can be performed when a user initiates heating, for example but not limited to the taking of a puff and activating a puff sensor which causes initiation of heating of the heater, or by the user pressing a “vape button” to similarly initiate heating of the heating element, which is lower than the power applied to the heater element during a steady state operation of the heater (e.g. during the majority of a user puff, which exemplarily can last about two (2) seconds but may be longer or shorter depending on the user, and the user&#39;s particular mood and/or circumstances at the time of taking the puff, etc., herein referred to as the NHC). 
     By employing such a reduced power ramp up phase the formation of undesirable chemicals (which are not typically present in the e-liquid prior to its vaporization but are rather most likely generated by means of an endothermic chemical reaction occurring during the heating of the e-liquid) may be mitigated because it is believed that these are predominantly formed outside of the steady state in which vaporization is occurring during the majority of a heating period (i.e. while a user is taking a “puff”); in particular, it is believed that such chemicals are predominantly formed during the initial heating up phase prior to the heating element reaching a temperature at which a “gas gap” is formed (once a gas gap has been formed, and provided the heating element maintains a sufficiently high temperature to maintain such a gas gap, no e-liquid directly touches the heating element because it vaporizes before it can touch the heating element). 
     Most likely, prior to a gas gap GG being formed, some of the molecules of the e-liquid may be more tightly bound to the heating element (which is typically formed of metal) than in a dynamic state where the liquid is flowing over the heating element or is separated from the heating element by a gas gap (for essentially similar reasons as to why static friction is typically greater than dynamic friction). In such a situation it is believed that a small number of molecules may reach a sufficiently high temperature (before vaporizing and evaporating away from the surface of the heating element) that instead of simply vaporizing into a gas form, they instead combine with neighboring molecules by means of a chemical reaction to form more complex chemicals (e.g. aldehydes) which may have an undesirable taste impact on the inhalation aerosol generated. Additionally, such chemicals may bind even more tightly to the metal heating element resulting in the additional problems noted above of deposits building up on the surface of the heating element over time after repeated inhalations. 
     By providing a reduced power during the formation of the gas gap, it is believed that more time is available for any e-liquid molecules adhering to the heating element to evaporate without having been chemically modified, before a sufficient temperature is reached by the molecules to enable them to undergo a chemical reaction so as to form a more complex, and organoleptically less desirable, chemical. 
     While the invention has been disclosed with reference to certain preferred embodiments, numerous modifications, alterations, and changes to the described embodiments, and equivalents thereof, are possible without departing from the sphere and scope of the invention. Accordingly, it is intended that the invention not be limited to the described embodiments, and be given the broadest reasonable interpretation in accordance with the language of the appended claims.