Patent Description:
Vaporizer devices, which can also be referred to as vaporizers, electronic vaporizer devices or e-vaporizer devices, can be used for delivery of an aerosol (or "vapor") containing one or more active ingredients by inhalation of the aerosol by a user of the vaporizing device. For example, electronic nicotine delivery systems (ENDS) include a class of vaporizer devices that are battery powered and that may be used to simulate the experience of smoking, but without burning of tobacco or other substances.

In use of a vaporizer device, the user inhales an aerosol, commonly called vapor, which may be generated by a heating element that vaporizes (e.g., causing a liquid or solid to at least partially transition to the gas phase) a vaporizable material, which may be liquid, a solution, a solid, a wax, or any other form as may be compatible with use of a specific vaporizer device. The vaporizable material used with a vaporizer can be provided within a cartridge (e.g., a separable part of the vaporizer that contains the vaporizable material in a reservoir) that includes a mouthpiece (e.g., for inhalation by a user).

To receive the inhalable aerosol generated by a vaporizer device, a user may, in certain examples, activate the vaporizer device by taking a puff, by pressing a button, or by some other approach. A puff, as the term is generally used (and also used herein), refers to inhalation by the user in a manner that causes a volume of air to be drawn into the vaporizer device such that the inhalable aerosol is generated by a combination of vaporized vaporizable material with the air.

A typical approach by which a vaporizer device generates an inhalable aerosol from a vaporizable material involves heating the vaporizable material in a vaporization chamber (or a heater chamber) to cause the vaporizable material to be converted to the gas (or vapor) phase. A vaporization chamber generally refers to an area or volume in the vaporizer device within which a heat source (e.g., conductive, convective, and/or radiative) causes heating of a vaporizable material to produce a mixture of air and vaporized vaporizable material to form a vapor for inhalation by a user of the vaporization device.

In some aspects, one or more components of the vaporizer device and/or vaporizer cartridge may become contaminated by a foreign material. Such contamination may affect the performance and/or functionality of the one or more components of the vaporizer device and/or the vaporizer cartridge. As such, improved vaporization devices and/or vaporization cartridges that improve upon or overcome these issues are desired.

In regard to the prior art, reference is made to document <CIT> disclosing a vaporizer device comprising a thermal flow sensor (<NUM>) configured to measure a mass flow rate of the vaporizable material across the surface of the thermal flow sensor, a heating element (<NUM>) and an outlet (<NUM>) of the vaporizer device. Moreover, documents <CIT>, <CIT> and <CIT> can be considered as background art.

In certain aspects of the current subject matter, challenges associated with the presence of liquid vaporizable materials in or near certain susceptible components of an electronic vaporizer device may be addressed by inclusion of one or more of the features described herein or comparable/equivalent approaches as would be understood by one of ordinary skill in the art. The current invention relates to a vaporizer device having the features of claim <NUM> and a method having the features of independent claim <NUM>.

In one aspect, a vaporizer device is described. The vaporizer device may include a reservoir configured to contain a vaporizable material. The vaporizer device may further include a heating element configured to vaporize the vaporizable material. The vaporizer device includes a thermal flow sensor configured to measure a mass flow rate of the vaporizable material across the surface of the thermal flow sensor. The thermal flow sensor is positioned along an airflow path between the heating element and an outlet of the vaporizer device. The thermal flow sensor includes a self-cleaning element configured to remove a liquid accumulated on the surface of the thermal flow sensor by at least evaporating the liquid. The self-cleaning element is activated in response to detecting an event that activates a cleaning cycle of the thermal flow sensor.

In one aspect, a method is described. The method includes detecting, by a processor, an event that activates a cleaning cycle of a sensor. The method further includes activating, by the thermopile configured to measure an upstream temperature of the vaporizable material. The thermal flow sensor may further include a second thermopile configured to measure a downstream temperature of the vaporizable material. The thermal flow sensor may further include a first heating element, positioned between the first thermopile and the second thermopile, configured to heat the vaporizable material. The first thermopile may be positioned upstream from the first heating element. The second thermopile may be positioned downstream from the first heating element. The thermal flow sensor may further include a second heating element configured to heat a liquid on a surface of the thermal flow sensor to a temperature sufficient to evaporate the liquid. The second temperature may be higher than the first temperature.

The second heating element may be coupled to the first heating element. The second heating element may be sized and configured to heat a threshold surface area of the thermal flow sensor. The second heating element may be activated in response to detecting that the vaporizer device is coupled to the charger. The second heating element may be activated in response to detecting an amount of liquid on the thermal flow sensor. The first heating element may heat the liquid to a first temperature. The second heating element may heat the liquid to a second temperature sufficient to evaporate the liquid.

Implementations of the current subject matter include devices relating to vaporizing of one or more materials for inhalation by a user. The term "vaporizer" is used generically in the following description to refer to a vaporizer device. Examples of vaporizers consistent with implementations of the current subject matter include electronic vaporizers or the like. Such vaporizers are generally portable, hand-held devices that heat a vaporizable material to provide an inhalable dose of the material.

The vaporizable material used with a vaporizer may optionally be provided within a cartridge (e.g., a part of the vaporizer that contains the vaporizable material in a reservoir or other container and that can be refillable when empty or disposable in favor of a new cartridge containing additional vaporizable material of a same or different type). A vaporizer may be a cartridge-using vaporizer, a cartridge-less vaporizer, or a multi-use vaporizer capable of use with or without a cartridge. For example, a multi-use vaporizer may include a heating chamber (e.g., an oven) configured to receive a vaporizable material directly in the heating chamber and also to receive a cartridge or other replaceable device having a reservoir, a volume, or the like for at least partially containing a usable amount of vaporizable material.

Some existing vaporizers may generate an inhalable aerosol with relatively little direct control over the mass of vaporizable material that is converted to aerosol. Such vaporizers may be improved by inclusion of one or more sensors to better characterize one or more parameters relating to vaporization. In some examples, it may be desirable to include a sensor that is capable of quantifying airflow past a part of the vaporizer in which vaporization of the vaporizable material is occurring. Such a sensor may be a thermal flow sensor, such as for example a device which measures flow conditions in airflow paths. The thermal flow sensor may measure fluid temperature at different points along a fluid flow (e.g., upstream and downstream). An amount of flow may be determined based on a temperature difference between the different measurement points.

The thermal flow sensor may be positioned in an airflow path and/or can be connected (e.g., by a passageway or other path) to an airflow path connecting an inlet for air to enter the device and an outlet via which the user inhales the resulting vapor and/or aerosol such that the pressure sensor experiences flow changes concurrently with air passing through the vaporizer device from the air inlet to the air outlet. In some aspects, the thermal flow sensor may be positioned within or proximate to the cartridge receptacle <NUM>. In some implementations, when the cartridge <NUM> is coupled to the vaporizer body <NUM>, liquid from the reservoir <NUM> may leak from the cartridge <NUM> into the cartridge receptacle <NUM>. Some of this liquid may contaminate the thermal flow sensor as described herein and may cause degradation in performance of the thermal flow sensor.

In various implementations, a vaporizer may be configured for use with liquid vaporizable material (e.g., a carrier solution in which an active and/or inactive ingredient(s) are suspended or held in solution or a neat liquid form of the vaporizable material itself) or a solid vaporizable material. A solid vaporizable material may include a plant material that emits some part of the plant material as the vaporizable material (e.g., such that some part of the plant material remains as waste after the vaporizable material is emitted for inhalation by a user) or optionally can be a solid form of the vaporizable material itself (e.g., a "wax") such that all of the solid material can eventually be vaporized for inhalation. A liquid vaporizable material can likewise be capable of being completely vaporized or can include some part of the liquid material that remains after all of the material suitable for inhalation has been consumed.

Referring to the block diagram of <FIG>, a vaporizer <NUM> typically includes a power source <NUM> (such as a battery which may be a rechargeable battery), and a controller <NUM> (e.g., a processor, circuitry, etc. capable of executing logic) for controlling delivery of heat to an atomizer <NUM> to cause a vaporizable material to be converted from a condensed form (e.g., a solid, a liquid, a solution, a suspension, a part of an at least partially unprocessed plant material, etc.) to the gas phase. The controller <NUM> may be part of one or more printed circuit boards (PCBs) consistent with certain implementations of the current subject matter.

After conversion of the vaporizable material to the gas phase, and depending on the type of vaporizer, the physical and chemical properties of the vaporizable material, and/or other factors, at least some of the gas-phase vaporizable material may condense to form particulate matter in at least a partial local equilibrium with the gas phase as part of an aerosol, which can form some or all of an inhalable dose provided by the vaporizer <NUM> for a given puff or draw on the vaporizer. It will be understood that the interplay between gas and condensed phases in an aerosol generated by a vaporizer can be complex and dynamic, as factors such as ambient temperature, relative humidity, chemistry, flow conditions in airflow paths (both inside the vaporizer and in the airways of a human or other animal), mixing of the gas-phase or aerosol-phase vaporizable material with other air streams, etc. may affect one or more physical parameters of an aerosol. In some vaporizers, and particularly for vaporizers for delivery of more volatile vaporizable materials, the inhalable dose may exist predominantly in the gas phase (i.e., formation of condensed phase particles may be very limited).

Vaporizers for use with liquid vaporizable materials (e.g., neat liquids, suspensions, solutions, mixtures, etc.) typically include an atomizer <NUM> in which a wicking element (also referred to herein as a wick (not shown in <FIG>), which can include any material capable of causing fluid motion by capillary pressure) conveys an amount of a liquid vaporizable material to a part of the atomizer that includes a heating element (also not shown in <FIG>). The wicking element is generally configured to draw liquid vaporizable material from a reservoir configured to contain (and that may in use contain) the liquid vaporizable material such that the liquid vaporizable material may be vaporized by heat delivered from a heating element. The wicking element may also optionally allow air to enter the reservoir to replace the volume of liquid removed. In other words, capillary action pulls liquid vaporizable material into the wick for vaporization by the heating element (described below), and air may, in some implementations, return to the reservoir through the wick to at least partially equalize pressure in the reservoir. Other approaches to allowing air back into the reservoir to equalize pressure are also within the scope of the current subject matter.

The heating element can be or include one or more of a conductive heater, a radiative heater, and a convective heater. One type of heating element is a resistive heating element, which can be constructed of or at least include a material (e.g., a metal or alloy, for example a nickel-chromium alloy, or a non-metallic resistor) configured to dissipate electrical power in the form of heat when electrical current is passed through one or more resistive segments of the heating element. In some implementations of the current subject matter, an atomizer can include a heating element that includes a resistive coil or other heating element wrapped around, positioned within, integrated into a bulk shape of, pressed into thermal contact with, or otherwise arranged to deliver heat to a wicking element to cause a liquid vaporizable material drawn by the wicking element from a reservoir to be vaporized for subsequent inhalation by a user in a gas and/or a condensed (e.g., aerosol particles or droplets) phase. Other wicking element, heating element, and/or atomizer assembly configurations are also possible, as discussed further below.

Certain vaporizers may also or alternatively be configured to create an inhalable dose of gas-phase and/or aerosol-phase vaporizable material via heating of a non-liquid vaporizable material, such as for example a solid-phase vaporizable material (e.g., a wax or the like) or plant material (e.g., tobacco leaves and/or parts of tobacco leaves) containing the vaporizable material. In such vaporizers, a resistive heating element may be part of or otherwise incorporated into or in thermal contact with the walls of an oven or other heating chamber into which the non-liquid vaporizable material is placed. Alternatively, a resistive heating element or elements may be used to heat air passing through or past the non-liquid vaporizable material to cause convective heating of the non-liquid vaporizable material. In still other examples, a resistive heating element or elements may be disposed in intimate contact with plant material such that direct conductive heating of the plant material occurs from within a mass of the plant material (e.g., as opposed to only by conduction inward form walls of an oven).

The heating element may be activated (e.g., a controller, which is optionally part of a vaporizer body as discussed below, may cause current to pass from the power source through a circuit including the resistive heating element, which is optionally part of a vaporizer cartridge as discussed below), in association with a user puffing (e.g., drawing, inhaling, etc.) on a mouthpiece <NUM> of the vaporizer to cause air to flow from an air inlet, along an airflow path that passes an atomizer (e.g., wicking element and heating element), optionally through one or more condensation areas or chambers, to an air outlet in the mouthpiece. Incoming air passing along the airflow path passes over, through, etc. the atomizer, where gas phase vaporizable material is entrained into the air. As noted above, the entrained gas-phase vaporizable material may condense as it passes through the remainder of the airflow path such that an inhalable dose of the vaporizable material in an aerosol form can be delivered from the air outlet (e.g., in a mouthpiece <NUM> for inhalation by a user).

Activation of the heating element may be caused by automatic detection of the puff based on one or more of signals generated by one or more sensors <NUM>, such as for example a pressure sensor or sensors disposed to detect pressure along the airflow path relative to ambient pressure (or optionally to measure changes in absolute pressure), one or more motion sensors of the vaporizer, one or more flow sensors of the vaporizer, a capacitive lip sensor of the vaporizer; in response to detection of interaction of a user with one or more input devices <NUM> (e.g., buttons or other tactile control devices of the vaporizer <NUM>), receipt of signals from a computing device in communication with the vaporizer; and/or via other approaches for determining that a puff is occurring or imminent.

As alluded to in the previous paragraph, a vaporizer consistent with implementations of the current subject matter may be configured to connect (e.g., wirelessly or via a wired connection) to a computing device (or optionally two or more devices) in communication with the vaporizer. To this end, the controller <NUM> may include communication hardware <NUM>. The controller <NUM> may also include a memory <NUM>. A computing device can be a component of a vaporizer system that also includes the vaporizer <NUM>, and can include its own communication hardware, which can establish a wireless communication channel with the communication hardware <NUM> of the vaporizer <NUM>. For example, a computing device used as part of a vaporizer system may include a general purpose computing device (e.g., a smartphone, a tablet, a personal computer, some other portable device such as a smartwatch, or the like) that executes software to produce a user interface for enabling a user of the device to interact with a vaporizer. In other implementations of the current subject matter, such a device used as part of a vaporizer system can be a dedicated piece of hardware such as a remote control or other wireless or wired device having one or more physical or soft (e.g., configurable on a screen or other display device and selectable via user interaction with a touch-sensitive screen or some other input device like a mouse, pointer, trackball, cursor buttons, or the like) interface controls. The vaporizer can also include one or more output <NUM> features or devices for providing information to the user.

In the example in which a computing device provides signals related to activation of the resistive heating element, or in other examples of coupling of a computing device with a vaporizer for implementation of various control or other functions, the computing device executes one or more computer instructions sets to provide a user interface and underlying data handling. In one example, detection by the computing device of user interaction with one or more user interface elements can cause the computing device to signal the vaporizer <NUM> to activate the heating element, either to a full operating temperature for creation of an inhalable dose of vapor/aerosol. Other functions of the vaporizer may be controlled by interaction of a user with a user interface on a computing device in communication with the vaporizer.

The temperature of a resistive heating element of a vaporizer may depend on a number of factors, including an amount of electrical power delivered to the resistive heating element and/or a duty cycle at which the electrical power is delivered, conductive heat transfer to other parts of the electronic vaporizer and/or to the environment, latent heat losses due to vaporization of a vaporizable material from the wicking element and/or the atomizer as a whole, and convective heat losses due to airflow (e.g., air moving across the heating element or the atomizer as a whole when a user inhales on the electronic vaporizer). As noted above, to reliably activate the heating element or heat the heating element to a desired temperature, a vaporizer may, in some implementations of the current subject matter, make use of signals from a pressure sensor to determine when a user is inhaling. The pressure sensor can be positioned in the airflow path and/or can be connected (e.g., by a passageway or other path) to an airflow path connecting an inlet for air to enter the device and an outlet via which the user inhales the resulting vapor and/or aerosol such that the pressure sensor experiences pressure changes concurrently with air passing through the vaporizer device from the air inlet to the air outlet. In some implementations of the current subject matter, the heating element may be activated in association with a user's puff, for example by automatic detection of the puff, for example by the pressure sensor detecting a pressure change in the airflow path.

A general class of vaporizers that have recently gained popularity includes a vaporizer body <NUM> that includes a controller <NUM>, a power source <NUM> (e.g., battery), the one more sensors <NUM>, charging contacts, a seal <NUM>, and a cartridge receptacle <NUM> configured to receive a vaporizer cartridge <NUM> for coupling with the vaporizer body through one or more of a variety of attachment structures. In some examples, vaporizer cartridge <NUM> includes a reservoir <NUM> for containing a liquid vaporizable material and a mouthpiece <NUM> for delivering an inhalable dose to a user. The vaporizer cartridge can include an atomizer <NUM> having a wicking element and a heating element, or alternatively, one or both of the wicking element and the heating element can be part of the vaporizer body. In implementations in which any part of the atomizer <NUM> (e.g., heating element and/or wicking element) is part of the vaporizer body, the vaporizer can be configured to supply liquid vaporizer material from a reservoir in the vaporizer cartridge to the atomizer part(s) included in the vaporizer body.

Cartridge-based configurations for vaporizers that generate an inhalable dose of a non-liquid vaporizable material via heating of a non-liquid vaporizable material can also be used. For example, a vaporizer cartridge may include a mass of a plant material that is processed and formed to have direct contact with parts of one or more resistive heating elements, and such a vaporizer cartridge may be configured to be coupled mechanically and electrically to a vaporizer body that includes a processor, a power source, and electrical contacts for connecting to corresponding cartridge contacts for completing a circuit with the one or more resistive heating elements.

In vaporizers in which the power source <NUM> is part of a vaporizer body <NUM> and a heating element is disposed in a vaporizer cartridge <NUM> configured to couple with the vaporizer body <NUM>, the vaporizer <NUM> may include electrical connection features (e.g., means for completing a circuit) for completing a circuit that includes the controller <NUM> (e.g., a printed circuit board, a microcontroller, or the like), the power source, and the heating element. These features may include at least two contacts on a bottom surface of the vaporizer cartridge <NUM> (referred to herein as cartridge contacts <NUM>) and at least two contacts disposed near a base of the cartridge receptacle (referred to herein as receptacle contacts <NUM>) of the vaporizer <NUM> such that the cartridge contacts <NUM> and the receptacle contacts <NUM> make electrical connections when the vaporizer cartridge <NUM> is inserted into and coupled with the cartridge receptacle <NUM>. The circuit completed by these electrical connections can allow delivery of electrical current to the resistive heating element and may further be used for additional functions, such as, for example, for measuring a resistance of the resistive heating element for use in determining and/or controlling a temperature of the resistive heating element based on a thermal coefficient of resistivity of the resistive heating element, for identifying a cartridge based on one or more electrical characteristics of a resistive heating element or the other circuitry of the vaporizer cartridge, etc..

In some examples, the at least two cartridge contacts and the at least two receptacle contacts can be configured to electrically connect in either of at least two orientations. In other words, one or more circuits necessary for operation of the vaporizer can be completed by insertion of a vaporizer cartridge <NUM> in the cartridge receptacle <NUM> in a first rotational orientation (around an axis along which the end of the vaporizer cartridge having the cartridge is inserted into the cartridge receptacle <NUM> of the vaporizer body <NUM>) such that a first cartridge contact of the at least two cartridge contacts <NUM> is electrically connected to a first receptacle contact of the at least two receptacle contacts <NUM> and a second cartridge contact of the at least two cartridge contacts <NUM> is electrically connected to a second receptacle contact of the at least two receptacle contacts <NUM>. Furthermore, the one or more circuits necessary for operation of the vaporizer can be completed by insertion of a vaporizer cartridge <NUM> in the cartridge receptacle <NUM> in a second rotational orientation such that the first cartridge contact of the at least two cartridge contacts <NUM> is electrically connected to the second receptacle contact of the at least two receptacle contacts <NUM> and the second cartridge contact of the at least two cartridge contacts <NUM> is electrically connected to the first receptacle contact of the at least two receptacle contacts <NUM>. This feature of a vaporizer cartridge <NUM> being reversible insertable into a cartridge receptacle <NUM> of the vaporizer body <NUM> is described further below.

In one example of an attachment structure for coupling a vaporizer cartridge <NUM> to a vaporizer body, the vaporizer body <NUM> includes a detent (e.g., a dimple, protrusion, etc.) protruding inwardly from an inner surface the cartridge receptacle <NUM>. One or more exterior surfaces of the vaporizer cartridge <NUM> can include corresponding recesses (not shown in <FIG>) that can fit and/or otherwise snap over such detents when an end of the vaporizer cartridge <NUM> inserted into the cartridge receptacle <NUM> on the vaporizer body <NUM>. When the vaporizer cartridge <NUM> and the vaporizer body <NUM> are coupled (e.g., by insertion of an end of the vaporizer cartridge <NUM> into the cartridge receptacle <NUM> of the vaporizer body <NUM>), the detent into the vaporizer body <NUM> may fit within and/or otherwise be held within the recesses of the vaporizer cartridge <NUM> to hold the vaporizer cartridge <NUM> in place when assembled. Such a detent-recess assembly can provide enough support to hold the vaporizer cartridge <NUM> in place to ensure good contact between the at least two cartridge contacts <NUM> and the at least two receptacle contacts <NUM>, while allowing release of the vaporizer cartridge <NUM> from the vaporizer body <NUM> when a user pulls with reasonable force on the vaporizer cartridge <NUM> to disengage the vaporizer cartridge <NUM> from the cartridge receptacle <NUM>.

Further to the discussion above about the electrical connections between a vaporizer cartridge and a vaporizer body being reversible such that at least two rotational orientations of the vaporizer cartridge in the cartridge receptacle are possible, in some vaporizers the shape of the vaporizer cartridge, or at least a shape of the end of the vaporizer cartridge that is configured for insertion into the cartridge receptacle may have rotational symmetry of at least order two. In other words, the vaporizer cartridge or at least the insertable end of the vaporizer cartridge may be symmetric upon a rotation of <NUM>° around an axis along which the vaporizer cartridge is inserted into the cartridge receptacle. In such a configuration, the circuitry of the vaporizer may support identical operation regardless of which symmetrical orientation of the vaporizer cartridge occurs.

In some examples, the vaporizer cartridge, or at least an end of the vaporizer cartridge configured for insertion in the cartridge receptacle may have a non-circular cross section transverse to the axis along which the vaporizer cartridge is inserted into the cartridge receptacle. For example, the non-circular cross section may be approximately rectangular, approximately elliptical (e.g., have an approximately oval shape), non-rectangular but with two sets of parallel or approximately parallel opposing sides (e.g., having a parallelogram-like shape), or other shapes having rotational symmetry of at least order two. In this context, approximately having a shape indicates that a basic likeness to the described shape is apparent, but that sides of the shape in question need not be completely linear and vertices need not be completely sharp. Rounding of both or either of edges or vertices of the cross-sectional shape is contemplated in the description of any non-circular cross section referred to herein.

The at least two cartridge contacts and the at least two receptacle contacts can take various forms. For example, one or both sets of contacts may include conductive pins, tabs, posts, receiving holes for pins or posts, or the like. Some types of contacts may include springs or other useful features to cause better physical and electrical contact between the contacts on the vaporizer cartridge and the vaporizer body. The electrical contacts may optionally be gold-plated, and/or can include other materials.

<FIG> illustrates an embodiment of the vaporizer device body <NUM> having a cartridge receptacle <NUM> into which the cartridge <NUM> may be releasably inserted. <FIG> shows a top view of the vaporization device <NUM> illustrating the cartridge being positioned for insertion into the vaporizer device body <NUM>. When a user puffs on the vaporization device <NUM>, air may pass between an outer surface of the cartridge <NUM> and an inner surface of a cartridge receptacle <NUM> on the vaporizer device body <NUM>. Air can then be drawn into an insertable end <NUM> of the cartridge, through the vaporization chamber that includes or contains the heating element and wick, and out through an outlet of the mouthpiece <NUM> for delivery of the inhalable aerosol to a user. The reservoir <NUM> of the cartridge <NUM> may be formed in whole or in part from translucent material such that a level of vaporizable material <NUM> is visible along the cartridge <NUM>.

<FIG> show top views before and after connecting a cartridge <NUM> to a vaporizer body <NUM>. <FIG> shows a perspective view of one variation of a cartridge <NUM> holding a liquid vaporizable material. In general, when a vaporizer includes a cartridge (such as the cartridge <NUM>), the cartridge <NUM> may include one or more reservoirs <NUM> of vaporizable material. Any appropriate vaporizable material may be contained within the reservoir <NUM> of the cartridge <NUM>, including solutions of nicotine or other organic materials.

<FIG> illustrate an example of a vaporizer <NUM> with a vaporizer body <NUM> and cartridge <NUM>. Vaporizer body <NUM> and cartridge <NUM> are shown unconnected in <FIG> and <FIG> and connected in <FIG> shows a perspective view of the combined vaporizer body <NUM> and cartridge <NUM>, and <FIG> shows an individual cartridge <NUM>. <FIG> depict an example including many of the features generally shown in <FIG>.

<FIG> illustrates an embodiment of the vaporizer device body <NUM> having a cartridge receptacle <NUM> and a sensor <NUM> (e.g., a thermal flow sensor) positioned proximate to the cartridge receptacle <NUM>. As shown in <FIG>, the sensor <NUM> may be in contact with the cartridge receptacle <NUM>, and any liquid contaminating the cartridge receptacle <NUM> (e.g., leaking from the cartridge <NUM>) may also contaminate the sensor <NUM>.

Typically, the pressure sensor (as well as any other sensors <NUM>) may be positioned on or coupled (e.g., electrically or electronically connected, either physically or via a wireless connection) to the controller <NUM> (e.g., a printed circuit board assembly or other type of circuit board). In some implementations, at least one of the one or more sensors <NUM> may be positioned within the cartridge <NUM>. To take measurements accurately and maintain durability of the vaporizer, it can be beneficial to provide a resilient seal <NUM> to separate an airflow path from other parts of the vaporizer. The seal <NUM>, which can be a gasket, may be configured to at least partially surround the pressure sensor such that connections of the pressure sensor to internal circuitry of the vaporizer are separated from a part of the pressure sensor exposed to the airflow path. In an example of a cartridge-based vaporizer, the seal <NUM> may also separate parts of one or more electrical connections between a vaporizer body <NUM> and a vaporizer cartridge <NUM>. Such arrangements of a seal <NUM> in a vaporizer <NUM> can be helpful in mitigating against potentially disruptive impacts on vaporizer components resulting from interactions with environmental factors such as water in the vapor or liquid phases, other fluids such as the vaporizable material, etc. and/or to reduce escape of air from the designed airflow path in the vaporizer. Unwanted air, liquid or other fluid passing and/or contacting circuitry of the vaporizer can cause various unwanted effects, such as altered pressure readings, and/or can result in the buildup of unwanted material, such as moisture, the vaporizable material, etc. in parts of the vaporizer where they may result in poor pressure signal, degradation of the pressure sensor or other components, and/or a shorter life of the vaporizer. Leaks in the seal <NUM> may also result in a user inhaling air that has passed over parts of the vaporizer device containing or constructed of materials that may not be desirable to be inhaled.

Consistent with implementations of the current subject matter, the one or more sensors <NUM> includes a thermal flow sensor. The thermal flow sensor may include a die configured to measure a mass flow rate of a liquid or gaseous medium across the surface of the die. When the sensor die is at least partially covered/contaminated by a liquid, the liquid may accumulate on the surface of the sensor and may thermally isolate the sensor and may reduce the sensor's sensitivity resulting in a much lower signal compared to the normal case where liquid is not present. To mitigate this problem, the thermal flow sensor, or any other sensor of the one or more sensors <NUM>, includes a self-cleaning element and/or process to evaporate the liquid or any other material that may affect the function of the sensor. In some aspects, the liquid may include at least some of the vaporizable material.

<FIG> illustrates an example of a thermal flow sensor <NUM>, in accordance with certain implementations of the current subject matter. As shown in <FIG>, the thermal flow sensor <NUM> comprises thermopiles 205A and 205B, a heater <NUM>, and a thermal isolation base <NUM>. As shown, the thermopile 205A may be positioned upstream (above) from the heater <NUM> and the thermopile 205B may be positioned downstream (below) from the heater <NUM>. The thermal isolation base <NUM> may be positioned to at least partially surround the heater <NUM> and any hot junction of the thermopiles <NUM>. In some aspects, the thermal isolation base <NUM> may be configured to allow the sensor die to be coated with various ceramic films to protect it from abrasive wear by dust particles in the flow medium, as well as liquids and certain corrosive gases.

As discussed above, if a sensing area of the thermal flow sensor <NUM> (e.g., area between the thermopiles 205A and 205B) is contaminated by a foreign material, the flow to sensor interface changes to produce varying sensitivity (e.g., flow to sensor voltage output). To address contamination concerns, the thermal flow sensor <NUM> may include a heating element configured to create a surface temperature on a silicon chip containing the thermal flow sensor <NUM> sufficient to evaporate any accumulated liquid on the surface of the chip. Due to the requirements of the heater <NUM> used to create the thermoelectric potential for the sense elements of the thermal flow sensor <NUM>, the heater <NUM> may not dissipate enough power to create enough heat to evaporate liquid that has accumulated on the surface of the silicon chip. As such, the thermal flow sensor <NUM> (and the silicon chip containing the sensor) may include an additional filament heater (shown below in <FIG>) which may be configured to produce sufficient heat to evaporate the undesirable surface liquid.

<FIG> illustrates the thermal flow sensor <NUM> with the additional filament heater <NUM>. <FIG> is similar to and adapted from <FIG>. At least some of the differences between <FIG> and <FIG> are described below. As shown in <FIG>, the thermal flow sensor <NUM> includes a bonding pad <NUM> coupled to a heater <NUM>. As described above, the heater <NUM> may be configured to produce sufficient heat to evaporate any accumulated liquid on the surface of the thermal flow sensor <NUM>. The heater <NUM> may be coupled to the heater <NUM>. In some implementations, the heater <NUM> may be configured to produce and sustain a temperature of at least <NUM> for at least <NUM> minutes in order to evaporate any liquid accumulated on the thermal flow sensor <NUM>. As shown, the heater <NUM> may be configured and positioned to cover a predetermined area or geometry of the thermal flow sensor <NUM>. While an example size and shape of the heater <NUM> is shown in <FIG>, other shapes and sizes of the heater <NUM> are also possible.

In some aspects, the use of the heater <NUM> may be incorporated into a clean cycle of the vaporizer <NUM>. For example, the heater <NUM> may be turned on periodically during a charging cycle of the vaporizer <NUM> (e. g, in response to detecting the vaporizer <NUM> is coupled to a charger). In some of the limitations, the heater <NUM> may be selectively powered on in response to a user input (e.g., through a graphical user interface (GUI) in communication with the vaporizer <NUM>). The heater <NUM> may also be selectively powered on in response to detecting an amount of liquid on a surface of the thermal flow sensor <NUM>. In some implementations, detecting an amount of liquid on the surface of the thermal flow sensor may include receiving an indication that a performance metric of the thermal flow sensor, the vaporizer device, or a component of the vaporizer device has fallen below a threshold (e.g., a flow rate has fallen below the threshold). In some implementations, the performance metric measurement may indicate that liquid residue has formed on the thermal flow sensor.

<FIG> is a flowchart illustrating a process <NUM> for cleaning a surface of a sensor or a component of a vaporizer device, in accordance with some example implementations. In some aspects, the process <NUM> may be implemented by a computing device having one or more processors, such as a smartphone, a tablet computer, a laptop, a vaporizer, or the like. For example, in some implementations of the current subject matter, the process <NUM> may be performed by the controller <NUM> at the vaporizer device <NUM> and/or at another device (e.g., a smartphone, a tablet computer, a laptop, and/or the like) communicatively coupled with the vaporizer device <NUM>.

At operational block <NUM> the process <NUM> may include detecting an event associated with activating a cleaning cycle of a sensor. For example, the event may include detecting the vaporizer device is coupled to the charger. The event may include detecting an amount of liquid on the sensor (e.g., the thermal flow sensor). The event may include detecting a change in performance of the sensor or other component of the vaporizer. The event may include a user input on a user interface in communication with a vaporizer device.

At operational block <NUM>, the process <NUM> may include responding to the event by at least activating a self-cleaning element configured to remove the liquid accumulated on the surface of the sensor by at least evaporating the liquid. For example, the self-cleaning element may include a second heating element (e.g., the heater <NUM>) configured to heat the liquid accumulated on the surface of the sensor. The sensor may include a first heating element, positioned between a first thermopile and a second thermopile, configured to heat the liquid accumulated on the surface of the sensor to a first temperature. The self-cleaning element may include a second heating element configured to heat the liquid accumulated on the surface of the sensor. The self-cleaning element may heat the liquid to a temperature (e.g., a second temperature) sufficient to evaporate the liquid. The second temperature may be greater than the first temperature (e.g., <NUM> for approximately <NUM> minutes).

In some aspects, the process <NUM> may optionally include performing a check to determine whether a threshold amount of the liquid accumulated on the sensor has evaporated. For example, the performance of the sensor may be checked to determine whether the sensor has been sufficiently cleaned to achieve a threshold performance level.

Terminology used herein is for the purpose of describing particular embodiments and implementations only and is not intended to be limiting.

Spatially relative terms, such as "forward", "rearward", "under", "below", "lower", "over", "upper" and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures.

Claim 1:
A vaporizer device (<NUM>) comprising:
a thermal flow sensor (<NUM>) configured to measure a mass flow rate of the vaporizable material across the surface of the thermal flow sensor (<NUM>),
wherein the thermal flow sensor (<NUM>) is positioned along an airflow path between the heating element (<NUM>) and an outlet of the vaporizer device (<NUM>), the thermal flow sensor (<NUM>) comprising:
a self-cleaning element configured to remove a liquid accumulated on the surface of the thermal flow sensor (<NUM>) by at least evaporating the liquid, the self-cleaning element activated in response to detecting an event that activates a cleaning cycle of the thermal flow sensor (<NUM>).