Patent Publication Number: US-11026451-B2

Title: Electronic cigarette fluid pump

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. provisional application No. 62/513,865, filed 1 Jun. 2017, which is hereby incorporated by reference as though fully set forth herein. 
    
    
     BACKGROUND 
     Field 
     The present disclosure relates to electronic cigarettes; more specifically, to electronic cigarettes with an active delivery system for transporting a liquid solution from a tank to an atomizer. 
     Background Art 
     Electronic cigarettes, also known as e-cigarettes (eCigs) and personal vaporizers (PVs), are electronic inhalers that vaporize or atomize a liquid solution into an aerosol mist, which is inhaled by a user. A typical rechargeable eCig has two main parts—a battery housing and a cartomizer. The battery housing typically includes a battery, a light emitting diode (LED), and a pressure sensor. The cartomizer typically includes a liquid solution, an atomizer, and a mouthpiece. The atomizer typically includes a heating coil that vaporizes the liquid solution. 
     To recharge the battery, a universal serial bus (USB) charger can be utilized which draws power from a computer or other power supply, converts the supplied power to the desired input for the battery, and supplies the desired input to the battery. In use, a user draws air through the atomizer, via the mouthpiece, to activate a heating coil that vaporizes the liquid solution into the air being drawn. After a number of draws, the battery must be recharged. Similarly, after a number of draws, the liquid solution within the cartomizer is depleted and must be replaced with another cartomizer. 
     BRIEF SUMMARY 
     Aspects of the present disclosure are directed to electronic cigarettes with an active delivery system for transporting a liquid solution (such as eCig juice) from a tank to an atomizer. Specifically, various embodiments of the present disclosure are directed to oscillating diaphragm pumps that facilitate flow of the liquid solution from the tank within a cartomizer to the atomizer and onto a heating coil for vaporization. 
     Various aspects of the present disclosure are directed to an electronic cigarette including a tank containing eCig juice, an atomizer, and an oscillating diaphragm pump. The atomizer includes a heating element, and vaporizes eCig juice into an airflow. The oscillating diaphragm pump includes a diaphragm and a permanent magnet. The oscillating diaphragm pump is positioned in fluid communication with the tank and the atomizer, and draws eCig juice from the tank and deposits the eCig juice on to the heating element. In more specific embodiments, the electronic cigarette further includes an electro-magnet that transmits an oscillating magnetic field in proximity to the permanent magnet. The permanent magnet produces a non-oscillating magnetic field that interacts with the oscillating magnetic field of the electro-magnet to linearly oscillate the diaphragm drawing eCig juice from the tank and injecting the eCig juice on to the heating element. 
     Other embodiments of the present disclosure are directed to an oscillating diaphragm pump that includes a diaphragm, a permanent magnet, and inlet and outlet valves. The diaphragm includes a deformable membrane, an inlet, and an outlet, and expands and contracts to pump a liquid solution through the oscillating diaphragm pump. The permanent magnet is coupled to the diaphragm, and produces a non-oscillating magnetic field that interacts with an oscillating magnetic field to sequentially attract and repel the permanent magnet, thereby expanding and contracting the diaphragm at the deformable membrane. The inlet valve is in fluid communication with the inlet of the diaphragm, and the outlet valve is in fluid communication with the outlet of the diaphragm. The inlet and outlet valves act to prevent reverse flow of the liquid solution through the oscillating diaphragm pump. In some specific embodiments, the oscillating diaphragm pump further includes an upper housing and a lower housing. The upper housing contains the outlet valve and the lower housing contains the inlet valve. At least one of the upper and lower housing may include a support member that circumferentially extends around at least a portion of one or both of the inlet and outlet valves. The support member stiffens one or both of the inlet and outlet valves to reduce back flow. 
     Additional features, advantages, and embodiments of the disclosure may be set forth or apparent from consideration of the detailed description and drawings. Moreover, it is to be understood that the foregoing summary of the disclosure and the following detailed description and drawings are exemplary and intended to provide further explanation without limiting the scope of the disclosure as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various example embodiments may be more completely understood in consideration of the following detailed description in connection with the accompanying drawings. 
         FIG. 1  is a schematic cross-sectional illustration of an exemplary e-cigarette, consistent with various aspects of the present disclosure. 
         FIG. 2  is an isometric side view of an oscillating diaphragm pump, consistent with various aspects of the present disclosure. 
         FIG. 3  is a partial cross-sectional side view of an electronic cigarette including an oscillating diaphragm pump, consistent with various aspects of the present disclosure. 
         FIG. 3A  is a partial cross-sectional side view of an electronic cigarette including an oscillating diaphragm pump, consistent with various aspects of the present disclosure. 
         FIG. 3B  is an exploded isometric view of an oscillating diaphragm pump assembly for an electronic cigarette, consistent with various aspects of the present disclosure. 
         FIG. 4  is a cross-sectional side view of an atomizer for an electronic cigarette, consistent with various aspects of the present disclosure. 
         FIG. 5  is an isometric side view of an atomizer of an electronic cigarette, consistent with various aspects of the present disclosure. 
         FIG. 5A  is an isometric front view of an alternative heating element for the atomizer of  FIG. 5 , consistent with various aspects of the present disclosure. 
         FIG. 5B  is an isometric front view of another alternative heating element for the atomizer of  FIG. 5 , consistent with various aspects of the present disclosure. 
         FIG. 6  is an cross-sectional side view of an oscillating diaphragm pump for an electronic cigarette, consistent with various aspects of the present disclosure. 
         FIG. 6A  is an exploded isometric side view of the oscillating diaphragm pump of  FIG. 6 , consistent with various aspects of the present disclosure. 
         FIG. 7  is an cross-sectional side view of an oscillating diaphragm pump for an electronic cigarette, consistent with various aspects of the present disclosure. 
         FIG. 7A  is an exploded isometric side view of the oscillating diaphragm pump of  FIG. 7 , consistent with various aspects of the present disclosure. 
         FIG. 7B  is a cross-sectional side view of the oscillating diaphragm pump of  FIG. 7  showing the fluid flow path during operation, consistent with various aspects of the present disclosure. 
         FIG. 7C  is a cross-sectional side view of the oscillating diaphragm pump of  FIG. 7  during a pull stroke, consistent with various aspects of the present disclosure. 
         FIG. 7D  is a cross-sectional side view of the oscillating diaphragm pump of  FIG. 7  during a push stroke, consistent with various aspects of the present disclosure. 
         FIG. 8  is a graph showing the operational characteristics of various oscillating diaphragm pump designs consistent with the present disclosure. 
         FIG. 9  is a graph showing the flow rate of an example oscillating diaphragm pump design in response to various input conditions, consistent with the present disclosure. 
     
    
    
     While various embodiments discussed herein are amenable to modifications and alternative forms, aspects thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the disclosure to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure including aspects defined in the claims. 
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     The disclosure and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and examples that are described and/or illustrated in the accompanying drawings and detailed in the following. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and features of one embodiment may be employed with other embodiments as the skilled artisan would recognize, even if not explicitly stated herein. Descriptions of well-known components and processing techniques may be omitted so as to not unnecessarily obscure the embodiments of the disclosure. The examples used herein are intended merely to facilitate an understanding of ways in which the disclosure may be practiced and to further enable those of skill in the art to practice the embodiments of the disclosure. Accordingly, the examples and embodiments herein should not be construed as limiting the scope of the disclosure. Moreover, it is noted that like reference numerals represent similar parts throughout the several views of the drawings. 
     Throughout the following, an electronic smoking device will be exemplarily described with reference to an e-cigarette. As is shown in  FIG. 1 , an e-cigarette  10  typically has a housing comprising a cylindrical hollow tube having an end cap  12 . The cylindrical hollow tube may be a single-piece or a multiple-piece tube. In  FIG. 1 , the cylindrical hollow tube is shown as a two-piece structure having a power supply portion  14  and an atomizer/liquid reservoir portion  16 . Together the power supply portion  14  and the atomizer/liquid reservoir portion  16  form a cylindrical tube which can be approximately the same size and shape as a conventional cigarette, typically about 100 millimeters (“mm”) with a 7.5 mm diameter, although lengths may range from 70 to 150 or 180 mm, and diameters from 5 to 28 mm. 
     The power supply portion  14  and atomizer/liquid reservoir portion  16  are typically made of metal (e.g., steel or aluminum, or of hardwearing plastic) and act together with the end cap  12  to provide a housing to contain the components of the e-cigarette  10 . The power supply portion  14  and the atomizer/liquid reservoir portion  16  may be configured to fit together by, for example, a friction push fit, a snap fit, a bayonet attachment, a magnetic fit, or screw threads. The end cap  12  is provided at the front end of the power supply portion  14 . The end cap  12  may be made from translucent plastic or other translucent material to allow a light-emitting diode (LED)  18  positioned near the end cap to emit light through the end cap. Alternatively, the end cap may be made of metal or other materials that do not allow light to pass. 
     An air inlet may be provided in the end cap, at the edge of the inlet next to the cylindrical hollow tube, anywhere along the length of the cylindrical hollow tube, or at the connection of the power supply portion  14  and the atomizer/liquid reservoir portion  16 .  FIG. 1  shows a pair of air inlets  20  provided at the intersection between the power supply portion  14  and the atomizer/liquid reservoir portion  16 . 
     A power supply, preferably a battery  22 , the LED  18 , control electronics  24  and, optionally, an airflow sensor  26  are provided within the cylindrical hollow tube power supply portion  14 . The battery  22  is electrically connected to the control electronics  24 , which are electrically connected to the LED  18  and the airflow sensor  26 . In this example, the LED  18  is at the front end of the power supply portion  14 , adjacent to the end cap  12 ; and the control electronics  24  and airflow sensor  26  are provided in the central cavity at the other end of the battery  22  adjacent the atomizer/liquid reservoir portion  16 . 
     The airflow sensor  26  acts as a puff detector, detecting a user puffing or sucking on the atomizer/liquid reservoir portion  16  of the e-cigarette  10 . The airflow sensor  26  can be any suitable sensor for detecting changes in airflow or air pressure, such as a microphone switch including a deformable membrane which is caused to move by variations in air pressure. Alternatively, the sensor may be, for example, a Hall element or an electro-mechanical sensor. 
     The control electronics  24  are also connected to an atomizer  28 . In the example shown, the atomizer  28  includes a heating coil  30  which is wrapped around a wick  32  extending across a central passage  34  of the atomizer/liquid reservoir portion  16 . The central passage  34  may, for example, be defined by one or more walls of the liquid reservoir and/or one or more walls of the atomizer/liquid reservoir portion  16  of the e cigarette  10 . The coil  30  may be positioned anywhere in the atomizer  28  and may be transverse or parallel to a longitudinal axis of a cylindrical liquid reservoir  36 . The wick  32  and heating coil  30  do not completely block the central passage  34 . Rather an air gap is provided on either side of the heating coil  30  enabling air to flow past the heating coil  30  and the wick  32 . The atomizer may alternatively use other forms of heating elements, such as ceramic heaters, or fiber or mesh material heaters. Nonresistance heating elements such as sonic, piezo, and jet spray may also be used in the atomizer in place of the heating coil. 
     The central passage  34  is surrounded by the cylindrical liquid reservoir  36  with the ends of the wick  32  abutting or extending into the liquid reservoir  36 . The wick  32  may be a porous material such as a bundle of fiberglass fibers or cotton or bamboo yarn, with liquid in the liquid reservoir  36  drawn by capillary action from the ends of the wick  32  towards the central portion of the wick  32  encircled by the heating coil  30 . 
     The liquid reservoir  36  may alternatively include wadding (not shown in  FIG. 1 ) soaked in liquid which encircles the central passage  34  with the ends of the wick  32  abutting the wadding. In other embodiments, the liquid reservoir may comprise a toroidal cavity arranged to be filled with liquid and with the ends of the wick  32  extending into the toroidal cavity. 
     An air inhalation port  38  is provided at the back end of the atomizer/liquid reservoir portion  16  remote from the end cap  12 . The inhalation port  38  may be formed from the cylindrical hollow tube atomizer/liquid reservoir portion  16  or may be formed in an end cap. 
     In use, a user sucks on the e-cigarette  10 . This causes air to be drawn into the e cigarette  10  via one or more air inlets, such as air inlets  20 , and to be drawn through the central passage  34  towards the air inhalation port  38 . The change in air pressure which arises is detected by the airflow sensor  26 , which generates an electrical signal that is passed to the control electronics  24 . In response to the signal, the control electronics  24  activate the heating coil  30 , which causes liquid present in the wick  32  to be vaporized creating an aerosol (which may comprise gaseous and liquid components) within the central passage  34 . As the user continues to suck on the e-cigarette  10 , this aerosol is drawn through the central passage  34  and inhaled by the user. At the same time, the control electronics  24  also activate the LED  18  causing the LED  18  to light up, which is visible via the translucent end cap  12 . Activation of the LED may mimic the appearance of a glowing ember at the end of a conventional cigarette. As liquid present in the wick  32  is converted into an aerosol, more liquid is drawn into the wick  32  from the liquid reservoir  36  by capillary action and thus is available to be converted into an aerosol through subsequent activation of the heating coil  30 . 
     Some e-cigarettes are intended to be disposable and the electric power in the battery  22  is intended to be sufficient to vaporize the liquid contained within the liquid reservoir  36 , after which the e-cigarette  10  is thrown away. In other embodiments, the battery  22  is rechargeable and the liquid reservoir  36  is refillable. In the cases where the liquid reservoir  36  is a toroidal cavity, this may be achieved by refilling the liquid reservoir  36  via a refill port (not shown in  FIG. 1 ). In other embodiments, the atomizer/liquid reservoir portion  16  of the e cigarette  10  is detachable from the power supply portion  14  and a new atomizer/liquid reservoir portion  16  can be fitted with a new liquid reservoir  36  thereby replenishing the supply of liquid. In some cases, replacing the liquid reservoir  36  may involve replacement of the heating coil  30  and the wick  32  along with the replacement of the liquid reservoir  36 . A replaceable unit comprising the atomizer  28  and the liquid reservoir  36  may be referred to as a cartomizer. 
     The new liquid reservoir may be in the form of a cartridge (not shown in  FIG. 1 ) defining a passage (or multiple passages) through which a user inhales aerosol. In other embodiments, the aerosol may flow around the exterior of the cartridge to the air inhalation port  38 . 
     Of course, in addition to the above description of the structure and function of a typical e cigarette  10 , variations also exist. For example, the LED  18  may be omitted. The airflow sensor  26  may be placed, for example, adjacent to the end cap  12  rather than in the middle of the e-cigarette. The airflow sensor  26  may be replaced by, or supplemented with, a switch which enables a user to activate the e cigarette manually rather than in response to the detection of a change in air flow or air pressure. 
     Different types of atomizers may be used. Thus, for example, the atomizer may have a heating coil in a cavity in the interior of a porous body soaked in liquid. In this design, aerosol is generated by evaporating the liquid within the porous body either by activation of the coil heating the porous body or alternatively by the heated air passing over or through the porous body. Alternatively the atomizer may use a piezoelectric atomizer to create an aerosol either in combination or in the absence of a heater. 
     Various aspects of the present disclosure are directed toward a pumping mechanism for electronic cigarette applications. Specifically, a pumping mechanism for delivering eCig juice from a tank to an atomizer for vaporization. To facilitate consistent performance, the pump must operate at a consistent rate regardless of conditions such as temperature and liquid level in the tank. To minimize costs, various embodiments may also include high tolerance parts. Moreover, embodiments of the pump disclosed herein may have minimal mass to prevent the eCig user from feeling a vibration associated with operation of the pump. In some applications, the pump mechanisms may pump at a rate of up to 5 mg/sec of liquid, and/or pump up to 100% vegetable glycerin or Propylene Glycol. 
     Various pumps in accordance with the present disclosure may include two or more one-way valves which are positioned in-line between an eCig fluid tank and an atomizer. The pumping action takes place in the space between the valves (e.g., a diaphragm), with the diaphragm between the valves expanding and contracting successively to pump eCig juice from the tank to the atomizer. In some embodiments, the pumping action is powered by an oscillating signal generator that drives a wire coil to create an oscillating magnetic field that acts on a permanent magnet that has been coupled to a portion of the pump. In response to the oscillating magnetic field, the diaphragm expands and contracts and thereby causes fluid to move through the pump. Such pumps are often referred to as oscillating diaphragm pumps. 
       FIG. 2  is an isometric view of an oscillating diaphragm pump  200 , consistent with various aspects of the present disclosure. The oscillating diaphragm pump  200  includes a housing  205  that forms a majority of the pump including a deformable membrane and a diaphragm. A ring-shaped permanent magnet  210  is coupled to an exterior of an oscillating portion of the pump  200 . In response to an oscillating magnetic field, the permanent magnet  210  causes the oscillating portion of the pump  200  to linearly actuate in a repeating fashion. The deformable membrane, in response to the oscillation changes the volume of the diaphragm within the pump  200 , and thereby effects a pressure change therein. The oscillating diaphragm pump may be positioned within an eCig to facilitate the flow of eCig juice from a tank, through an inlet valve of the pump  200  (which may be located in fluid contact with the tank), and out of an outlet valve  206 . The outlet valve  206  may be placed in close proximity to a atomizer to facilitate disbursement of the eCig juice onto a heating coil therein. 
       FIG. 3  is a partial cross-sectional side view of an electronic cigarette  300  including an oscillating diaphragm pump  305 , consistent with various aspects of the present disclosure. The oscillating diaphragm pump  305  is coupled to the rest of the eCig  300  via an upper mount  320   A  and a lower mount  320   B . The upper mount  320   A  facilitates expansion and contraction of deformable membrane  307  (and thereby the diaphragm itself) into and out of the diaphragm expansion region  321 . The deformable membrane  307  includes a fold that facilitates movement of upper housing  305   B  and permanent magnet  310  relative to lower housing  305   A  freely back and forth when exposed to an oscillating magnetic field. 
     An electro-magnet  315 , within eCig  300 , may circumferentially surrounds at least a portion of an upper housing  305   B  of oscillating diaphragm pump  305 . When controller circuitry within the eCig  300  detects a user&#39;s draw on the eCig, an oscillating signal generator drives the electro-magnet  315 . The electro-magnet  315 , in response to the oscillating generator signal, radiates an oscillating magnetic field in proximity to permanent magnet  310 . The permanent magnet  310 , in response to the magnetic field, exerts a fluctuating force on the oscillating diaphragm pump  305 . When the magnetic field emitted from the electro-magnet  315  opposes the magnetic field of the permanent magnet  310 , the diaphragm contracts (as facilitated by deformable membrane  307 ). This increases the pressure within the diaphragm, closing inlet valve  306   B  (e.g., a duckbill valve), and opening outlet valve  306   A . Accordingly, eCig juice within the pump  305  is propelled into an atomizer chamber  328 . 
     When the magnetic field emitted from the electro-magnet  315  attracts the magnetic field of the permanent magnet  310 , the diaphragm expands. This creates a vacuum pressure within the diaphragm, closing outlet valve  306   A , and opening inlet valve  306   B . The open inlet valve  306   B  draws eCig juice from within a liquid reservoir  336  (also referred to as a tank) into the diaphragm. 
     The pumping process of the oscillating diaphragm pump  305  continues, for example, until controller circuitry within the eCig  300  detects a user&#39;s discontinued draw on the eCig, and disables the oscillating signal generator—which thereby dissipates the magnetic field acting on the permanent magnet  310  of the pump  305 . In some embodiments, the controller circuitry may be programmed to turn-off the oscillating diaphragm pump  305  after a set time. In other embodiments, the pump may be disabled after the tank has run out of eCig juice, or a current draw from the heating coil (during vaporization) indicates that the heating coil is inundated with eCig juice. 
     It is to be understood, in the embodiment of  FIG. 3 , that upper housing  305   B  may dynamically expand and contract (due-in-part to deformable membrane  307 ) within, and relative to, the upper mount  320   A . Lower housing  305   A , however, is coupled to and held static by lower mount  320   B . The permanent magnet  310 , as it is coupled to upper housing  305   B , moves with the upper housing  305   B  in response to the magnetic field produced by electro-magnet  315 . 
     To assemble oscillating diaphragm pump  305  within ecig  300 , lower housing  305   A  is inserted into lower mount  320   B  with shoulder feature  341  limiting the insertion of the lower housing  305   A  into the lower mount  320   B . An upper housing  305   B , including a deformable membrane  307  and a permanent magnet  310  coupled thereto, may then be partially inserted into the lower mount  320   B . The deformable membrane  307  is located between the lower and upper housings,  305   A  and  305   B , respectively. An upper mount  320   A  may then be lowered over the upper housing  305   B . The upper mount  320   A  couples to the lower mount  320   B  at interlock  340 , which sandwiches the deformable membrane  307  and lower housing  305   A  between the shoulder feature  341  of the lower mount  320   B  and the upper mount  320   A . The resulting assembly facilitates expansion and contraction of the deformable membrane  307  and the upper housing  305   B  mounted thereto. 
       FIG. 3A  is a partial cross-sectional side view of an electronic cigarette  300 ′ including an oscillating diaphragm pump  305 ′, consistent with various aspects of the present disclosure. Similar to  FIG. 3 , the present eCig  300 ′ includes an electro-magnet  315 ′ circumferentially extending around at least a portion of the pump  305 ′. The eCig  300 ′ also delivers eCig juice from a liquid reservoir  336 ′, through an inlet valve  306   B ′, into a diaphragm of the pump  305 ′, through the outlet valve  306   A ′, and into an atomizer chamber  328 ′. However, in the present embodiment, upper housing  305 B′ includes a support member  322  (similar to the support member  322  for the lower housing  305   A ′) that circumferentially extends around the outlet valve  306 A′ and aids in stiffening the outlet valve to reduce back flow. Moreover, the support member  322  facilitates the mounting of a larger permanent magnet  310 ′ to the pump  305 ′. A larger permanent magnet may facilitate improved pump performance. However, in various embodiments of the present disclosure it is desirable to limit the oscillating mass of the pump  305 ′ to prevent a noticeable vibration of the eCig  300 ′ by the user. 
       FIG. 3B  is an exploded isometric view of an oscillating diaphragm pump assembly  301  for an electronic cigarette, consistent with various aspects of the present disclosure. Upper housing  305   B ′ and lower housing  305   A ′ may be held together by the coupling of upper mount  320   A ′ and lower mount  320   B ′. In other embodiments, the upper and lower housings ( 305   B ′ and  305   A ′, respectively) may be coupled using an adhesive, welding process (e.g., ultrasonic welding), or fasteners. In the present embodiment, the upper and lower housing portions are placed within a cavity of the upper mount  320   A ′, and the lower mount  320   B ′ is coupled to the upper mount using snap features on respective portions of the upper and lower mounts. In yet other embodiments, the upper and lower mounts may be coupled via means well known in the arts (e.g., welding, adhesives, fasteners, etc.). A permanent magnet  310 ′, in the present embodiment, may be press fit onto the upper housing portion  305   B ′. As discussed above, other fastening means may also be used to fasten the permanent magnet  310 ′ to the upper housing portion  305   B ′. 
       FIG. 4  is a cross-sectional side view of an atomizer  400  of an electronic cigarette, consistent with various aspects of the present disclosure. The atomizer  400  facilitates vaporing eCig juice into an air stream. Oscillating diaphragm pumps, as disclosed herein, deliver eCig juice from a eCig juice tank to solution apertures  451   A-N  that are distributed about a cylindrical frit  450 . The eCig juice is pumped through the solution apertures  451   A-N  and into contact with heating element  455  via heating element contact points  453   A-N . When an electrical current is driven through the heating element  455 , the eCig juice thereon warms until reaching a vaporization temperature. Once vaporized, the vaporized eCig juice is drawn into an air flow (to create an aerosol) that is drawn out of the frit  450  via aerosol exit apertures  452   A-B  which deliver the aerosol to a user&#39;s mouth. 
     Aspects of atomizer  400  are directed to a heating element  455  that is a square helix. The square helix minimizes heating element contact points  453   A-N  with frit  450 . In various embodiments of the present disclosure, it is desirable to minimize contact between the frit  450  and the heating element  455 . By minimizing contact, the drive current required to vaporize eCig juice on the heating element is reduced. Specifically, less heating energy is lost to the frit  450 , and accordingly battery life of the eCig is improved. However, positioning the heating element  455  in close proximity to the frit  450  is also desirable to facilitate eCig juice transmission from the solution apertures  451   A-N  of the frit  450  to the heating element  455 . 
     In various embodiments of an eCig consistent with the present disclosure, it is desirable to aerosolize a large amount of eCig juice (e.g., up to 5 mg/sec) while maintaining a small form factor eCig. Existing eCig designs facilitate aerosolizing up to 2 mg/sec of eCig juice by dispensing the eCig juice directly onto a heating element by pumping it out of a stainless steel needle onto either an interior or exterior surface of the heating element. At amounts greater than 2 mg/sec, the heating element may become saturated with eCig juice (unless the heating element is made larger, which may be impractical due to size and electrical current usage constraints). This saturation may cause some of the eCig juice to be boiled off, leading to splattering of the eCig juice onto an interior surface of the airway. Aspects of the present disclosure solve such problems by dispensing eCig juice through one or more apertures extending through the frit and onto the heater element. To further facilitate vaporization of eCig juice on the heating element, the air that is drawn into the atomizer chamber is directed through the middle of the heating element. In some specific embodiments, a glass or ceramic frit may be used to dispense the eCig juice onto the heating element. In other embodiments, a small, ceramic-coated steel tube with apertures may be used to dispense the eCig juice onto the heating element. In yet other embodiments, a glass airway with apertures may be used to dispense the eCig juice onto the heating element. 
     In various embodiments of the present disclosure, the heating element may be held against the wall of the frit/steel/glass tube, or in close proximity (e.g., within 0.5 millimeters (“mm”) and preferable within 0.25 mm) from the inner wall of the tube. Such embodiments decrease and/or preclude splattering of the eCig juice during vaporization. However, one drawback of such an embodiment is that the close proximity of the heating element to the frit requires more electrical power due to energy loss to the frit. Aspects of the present disclosure address this issue through the use of unique heating element shapes that further reduce heating element contact with the frit. 
       FIG. 5  is an isometric side view of an atomizer  500  of an electronic cigarette. The atomizer  500  includes a heating element  555  placed within a frit  550 . In the present embodiment, the frit  550  may be a steel or glass tube, and facilitates the flow of air over the heating element  555 . The heating element  555  is a triangularly-shaped helix that minimizes the contact between the heating element coils and the frit  550 . Specifically, for each winding of the heating element  555 , there are only three heating element contact points  553   A-N . As discussed above, minimizing the contact points between the heating element  555  and the frit  550  reduces the energy draw required on the battery to vaporize eCig juice on the heating element. In the present embodiment, to facilitate airflow through the frit  550 , and to facilitate electrical coupling of the heating element  555  to driver circuitry, lead wires  554   A-B  exit on the same end of the atomizer  500 . Moreover, it has been discovered that assembling the atomizer  500  in such a way as to position the lead wires  554   A-B  to exit the upwind end of the atomizer also exhibits improved performance. 
     In  FIG. 5 , solution apertures  551   A-N  are circumferentially distributed about frit  550 . In the present embodiment, the solution apertures  551   A-N  are unevenly distributed near an upwind portion of atomizer  500 . However, other embodiments may more evenly distribute such solution apertures  551   A-N  about a length of the frit  550 . When an oscillating diaphragm pump, as disclosed herein, is operating, eCig juice is pumped through the solution apertures  551   A-N  in the frit  550  and into contact with heating element  555  via heating element contact points  553   A-N . In various embodiments, it is desirable to vaporize eCig juice at a downwind end of the atomizer  500 , relative to a user&#39;s mouth, to facilitate consistency of the aerosol density per unit volume of air delivered to the user. 
       FIG. 5A  is an isometric front view of an alternative heating element  555  of the atomizer of  FIG. 5 , consistent with various aspects of the present disclosure. The heating element  555 ′ of  FIG. 5A  is a square helix with two lead wires  554   A-B  extending from a distal end of the heating element. Each winding of the heating element  555 ′ includes 4 contact points  553   A-D , respectively. The contact points  553   A-D  facilitate the flow of eCig juice from a frit surrounding the heating element  555 ′, to the heating element itself for vaporization, while also limiting electrical loss through the frit. 
       FIG. 5B  is an isometric front view of another alternative heating element  555 ″ for the various electronic cigarettes disclosed herein. The heating element  555 ″ has a central lead wire  554   A  that extends along a length of a longitudinal axis of the heating element. Heating coils of the heating element wrap around the central lead wire  554   A  and extend to a second lead wire  554   B . To limit energy loss when the heating element  555 ″ is assembled within a frit, the heating element may be positioned so that it is not in electrical contact with the frit, but close enough to facilitate eCig juice flow from the frit to the heating element. In some embodiments, the heating element  555  and frit are maintained at a separation of 0.5 mm, and more preferably within 0.25 mm. 
     In the heating element  555 ″ shown in  FIG. 5B , the inner diameter may be 2.5 mm and the outer diameter may be 6 mm. In some embodiments, the heating element may be between 8 and 12 mm in length. 
     As further shown in  FIG. 5B , the coils of the heating element  555 ″ may vary in both pitch and diameter along a length of the longitudinal axis. For example, as shown in  FIG. 5B , a first portion  560  of the heating coil has a first pitch and first diameter. A second portion  561  of the heating coil has a second pitch which is less than the first pitch and a second diameter which is less than the first diameter. In yet other embodiments consistent with the present disclosure, the pitch and diameter of the heating coil may be continuously variable along a length of the coil or may include three or more portions with varying pitch and diameter characteristics. 
     In various embodiments consistent with the present disclosure, in order to get eCig juice to properly wet and flow along the heating element (to facilitate even distribution along the coils), a surface finish may be applied to the heating element. In some specific embodiments, ceramic coatings may be applied to the heating element. These ceramic coatings, and other surface finishes, may comprise a smooth or rough surface application. Similarly, an interior surface of the frit may also be coated to aid in wetting of the heating element. Additionally, the ceramic coating of the heating element may help preclude electrical shorting of the heating element coils to one another. 
     An alternative to surface finishes and coatings on the heating element is to roughen the surface of the heating element either though bead and/or sand blasting, chemical etching, knurling or sand paper application(s) to create ridges and increase the surface area. Similar to surface finishes and coating, surface roughening may aid in wetting the heating element. 
     An alternative heating element design may use a thin foil heater. In some embodiments, the thin foil heater may be between 6 and 25 microns thick. The thin foil heater may be made of a metal, such as stainless steel, with holes etched in the foil, and the foil wrapped to form a tube. The etched holes may be used to increase the electrical resistance of the heating element, and to aid in wetting the heating element with eCig juice. 
       FIG. 6  is a cross-sectional side view of an oscillating diaphragm pump  600  for an electronic cigarette, consistent with various aspects of the present disclosure. The oscillating diaphragm pump  600  facilitates an input and output on the same side of the pump. Such a configuration enables novel eCig design configurations—such as eCig juice tank mating to the pump from the same side as an airway and a mouthpiece. 
     In  FIG. 6 , eCig juice from a tank enters the oscillating diaphragm pump  600  from an Inlet. An inlet valve  606   B  acts as a one-way valve that draws eCig juice from the tank into an inlet chamber  624  in response to a vacuum pressure within the inlet chamber  624 . Once the inlet chamber  624  has reached an equilibrium pressure with the eCig tank, the inlet valve  606   B  closes, with a portion of the inlet chamber  624  filled with eCig juice. The vacuum pressure in the inlet chamber  624  is caused by a change in volume of a diaphragm  625 . The oscillating diaphragm pump  600 , in response to an oscillating magnetic field, linearly actuates an oscillator  623  which is coupled to a permanent magnet  610  which the oscillating magnetic field acts on. When the magnetic field causes an expansion of the diaphragm  625 , the inlet chamber  624  is placed into a vacuum pressure to open the inlet valve  606   B  (as discussed above); simultaneously, the vacuum pressure causes outlet valve  606   A  to close preventing a flow of eCig juice from an outlet chamber  626  out through the Outlet. 
     When the magnetic field repels the permanent magnet  610 , the diaphragm  625  contracts, creating a positive pressure in the inlet chamber  624  which closes the inlet valve  606   B , while similarly creating a positive pressure in the outlet chamber  626  that opens the outlet valve  606   A  facilitating a flow of eCig juice from the outlet chamber  626  through the Outlet (and into an atomizer). 
     Where the diaphragm  625  is expanded at a deformable membrane  607 , eCig juice within the inlet chamber  624  is drawn into the diaphragm  625 . Where the diaphragm  625  is contracted at the deformable membrane  607 , eCig juice within the diaphragm flows into the outlet chamber  626  (due to the lower pressure within the outlet chamber  626  compared to inlet chamber  624 ). The oscillating diaphragm pump  600  may be driven by a magnetic field with variable voltage and frequency to adjust the pumping rate of the pump. Moreover, the diaphragm  625  travel length may be adjustable or designed with a specific travel length to suit a specific pumping application. For example, in applications where high flow rates to the atomizer are desirable, the travel length of the diaphragm  625  may be longer (e.g., 0.05 inches), and/or the voltage or frequency of the oscillating magnetic field may be adjusted. 
       FIG. 6A  is an exploded isometric view of the oscillating diaphragm pump  600  of  FIG. 6 , consistent with various aspects of the present disclosure. An inner assembly  627  of the pump is sandwiched between an upper mount  620   A  and a lower mount  620   B , with a permanent magnet  610  coupled to a distal portion of the inner assembly  627  to facilitate linear actuation of the diaphragm. Aspects of the present disclosure are directed toward reducing cost and assembly complexity by injection molding the inner assembly  627  as a single part. Accordingly, the pump  600  is assembled with only four parts, greatly reducing assembly time and cost. Moreover, the internal components (e.g., the inner assembly  627 ) do not require intricate assembly as is common with pumps of similar size. In various embodiments, the upper mount  620   A  and the lower mount  620   B  may be coupled to one another via snap features, further simplifying the pump assembly  600 . 
       FIG. 7  is a cross-sectional side view of an oscillating diaphragm pump  700  for an electronic cigarette, consistent with various aspects of the present disclosure. In  FIG. 7 , the duckbill valves of  FIG. 6  have been replaced with an alternative valve design. 
     In  FIG. 7 , eCig juice from a tank enters the oscillating diaphragm pump  700  from an Inlet. An inlet valve  706   B  acts as a one-way valve that draws eCig juice from a tank into a diaphragm  725  in response to a vacuum pressure created within the inlet chamber  724  by the diaphragm  725 . Once the inlet chamber  724  reaches an equilibrium pressure with the diaphragm  725 , the inlet valve  706   B  closes, with a portion of the diaphragm  725  filled with eCig juice. The vacuum pressure in the inlet chamber  724  is caused by a change in volume of the diaphragm  725  due in part to deformable membrane  707 . The oscillating diaphragm pump  700 , in response to an oscillating magnetic field, linearly actuates an oscillator  723  which is coupled to a permanent magnet  710 , which the oscillating magnetic field acts on. When the magnetic field causes an expansion of the diaphragm  725 , the diaphragm and the inlet chamber  724 , which is in fluid communication with the diaphragm, is placed into a vacuum pressure which opens the inlet valve  706   B  Simultaneously, the vacuum pressure causes the outlet valve  706   A  to close due to the air intake fluidly coupled to outlet chamber  726 , preventing a flow of eCig juice from a diaphragm  725  through an outlet valve  706   A  to the Outlet. 
       FIG. 7A  is an exploded isometric view of the oscillating diaphragm pump  700  of  FIG. 7 , consistent with various aspects of the present disclosure. An inner assembly  727  of the pump is sandwiched between an upper mount  720   A-  and a lower mount  720   B , with a permanent magnet  710  coupled to a distal portion of the inner assembly  727  to facilitate linear actuation of the diaphragm. Aspects of the present disclosure are directed toward reducing cost and assembly complexity by injection molding the inner assembly  727  as a single part. The inner assembly  727  may be molded from a silicone, for example, which facilitates deformation of the valves and diaphragm, in response to a pressure, but being capable of returning to a natural state once the pressure is alleviated. 
       FIG. 7B  is a cross-sectional side view of the oscillating diaphragm pump  700  of  FIG. 7  showing the fluid flow path during operation, consistent with various aspects of the present disclosure. As shown in  FIG. 7B , an oscillating diaphragm pump  700 , in response to an oscillating magnetic field, linearly actuates an oscillator  723  with a permanent magnet (not shown) coupled thereto. The oscillating magnetic field acts on the permanent magnet. When the magnetic field attracts the permanent magnet, the permanent magnet draws the oscillator  723  toward the electromagnet (the pull stroke), causing an expansion of the diaphragm  725 . The expansion of the diaphragm  725  creates a vacuum pressure in both the diaphragm, itself, and the fluidly coupled inlet chamber  724 . The induced vacuum pressure in the inlet chamber opens inlet valve  706   B . Simultaneously, the vacuum pressure in the diaphragm  725  causes the outlet valve  706   A  to close, preventing a flow of eCig juice out through the Outlet. The outlet valve  706   A  closes due to the pressure within the diaphragm  725  being less than an ambient pressure within outlet chamber  726  as regulated by the Air Intake/Outlet. 
     During a push stroke of the oscillating diaphragm pump  700 , a magnetic field repels the permanent magnet attached to the oscillator  723 , causing the diaphragm  725  to contract. The contraction of the diaphragm  725  creates a positive pressure in the diaphragm  725  which exceeds a pressure at the Inlet. The positive pressure extends into inlet chamber  724  to close inlet valve  706   B . The positive pressure in the diaphragm  725  also exerts a positive pressure on an outlet valve  706   A  that overcomes the ambient pressure within outlet chamber  726 —facilitating the flow of eCig juice from the diaphragm  725 , out the outlet valve  706   A . 
       FIG. 7C  is a cross-sectional side view of an oscillating diaphragm pump  701  during a pull stroke, consistent with various aspects of the present disclosure. During the pull stroke of the pumping action of the oscillating diaphragm pump  701 , a majority of the pumping system experiences a vacuum pressure. Specifically, a diaphragm  725  draws a vacuum and its fluid communication with inlet chamber  724  also places the inlet chamber  724  into a vacuum. The vacuum created within the inlet chamber  724  opens inlet valve  706   B  drawing eCig juice into the diaphragm  725 . The vacuum pressure created by the diaphragm also acts on the outlet valve  706   A . Specifically, the vacuum pressure, once it exceeds the opposing force (atmospheric pressure) acting on the outlet valve  706   A , closes the outlet valve  706   A  to prevent the flow of eCig juice out of the pump  701  during a pull stroke. Accordingly, the pull stroke draws eCig juice into diaphragm  725  from a tank, but does not discharge any eCig juice into an atomizer. 
       FIG. 7D  is a cross-sectional side view of an oscillating diaphragm pump  702  during a push stroke, consistent with various aspects of the present disclosure. During the push stroke, a diaphragm  725  experiences a positive pressure. The positive pressure from the diaphragm  725  is fluidly communicated to an inlet chamber  724 —causing a positive pressure therein. The positive pressure within the inlet chamber  724  overcomes the atmospheric pressure within the eCig juice tank to close inlet valve  706   B . The positive pressure is also exerted on an outlet valve  706   A . The positive pressure exerted on the outlet valve  706   A , once it exceeds an atmospheric pressure within outlet chamber  726 , opens the outlet valve  706   A  and facilitates the flow of eCig juice from the diaphragm  725  into an atomizer. 
     Aspects of the present disclosure are directed to an electronic cigarette including a tank containing eCig juice, an atomizer, and an oscillating diaphragm pump. The atomizer includes a heating element, and vaporizes eCig juice into an airflow. The oscillating diaphragm pump includes a diaphragm and a permanent magnet. The oscillating diaphragm pump is positioned in fluid communication with the tank and the atomizer, draws eCig juice from the tank, and deposits the eCig juice on to the heating element. In further embodiments, the electronic cigarette includes an electro-magnet that transmits an oscillating magnetic field in proximity to the permanent magnet. The permanent magnet produces a non-oscillating magnetic field that interacts with the oscillating magnetic field of the electro-magnet to linearly oscillate the diaphragm which draws eCig juice from the tank and injects the eCig juice on to the heating element. In yet further embodiments, the electronic cigarette may include controller circuitry that is electrically coupled to the electro-magnet and the heating element. The controller circuitry detects a draw on the electronic cigarette. Then, in response to the draw, the controller circuitry transmits an oscillating electric signal that drives the electro-magnet, and thereby the permanent magnet of the oscillating diaphragm pump to cause eCig juice to be deposited on to the heating element. Further in response to the draw, the controller circuitry drives the heating element with a current sufficient to vaporize the eCig juice on the heating element. 
     In some embodiments, an oscillating diaphragm pump includes an inlet valve and an outlet valve. The inlet valve is placed in fluid communication with an inlet of the diaphragm, and the outlet valve is placed in fluid communication with an outlet of the diaphragm. The inlet and outlet valves prevent reverse flow of the eCig juice through the oscillating diaphragm pump. In more specific embodiments, the oscillating diaphragm pump further includes an upper housing and a lower housing. The upper housing contains the outlet valve, the lower housing contains the inlet valve, and at least one of the upper and lower housing includes a support member circumferentially extending around at least a portion of one or both of the inlet and outlet valves. The support member stiffens one or both of the inlet and outlet valves and reduces back flow. 
     An oscillating diaphragm pump, in accordance with the present disclosure, may include a deformable membrane that facilitates expansion and contraction of the diaphragm. 
     An atomizer of an electronic cigarette, consistent with the present disclosure, may include a frit that houses the heating element. The frit may include one or more apertures that extend through the frit, and that deliver eCig juice to the heating element. In some embodiments, the heating element is a non-circular, helical coil that minimizes contact between the heating element and the frit. In more specific embodiments, the heating element is one of a square-shaped, helical coil, and a triangle-shaped, helical coil. In yet other embodiments, the heating element is offset from an inner diameter of the frit by less than 0.25 millimeters. 
     In some embodiments, an atomizer of an electronic cigarette directs airflow through a cavity of the heating element, and the heating element includes a ceramic coating that facilitates wetting the heating element with eCig juice and mitigates electrical shorting of adjacent heating element coils. 
     In eCigs including controller circuitry, the controller circuitry may detect the strength of a draw, adjust the transmitted oscillating electric signal that drives the electro-magnet, and adjust the current delivered to the heating element to maintain a consistent vapor content per airflow volume delivered to a user. 
     Aspects of the present disclosure are directed to oscillating diaphragm pumps that pump eCig juice at a flow rate of up to 10 mg/sec with a pressure of approximately 0.5 psi. In some embodiments, the oscillating diaphragm pump has a diaphragm travel length between 0.03 and 0.05 inches. 
     Heating elements, in accordance with the present disclosure, may include a rough exterior surface that facilitates wetting the heating element with eCig juice, and mitigates electrical shorting of adjacent heating element coils. 
     Various embodiments of the present disclosure are directed to an oscillating diaphragm pump including a diaphragm, a permanent magnet, an inlet valve, and an outlet valve. The diaphragm includes a deformable membrane, an inlet, and an outlet. The diaphragm expands and contracts, and thereby pumps a liquid solution through the oscillating diaphragm pump. The permanent magnet is coupled to the diaphragm, and produces a non-oscillating magnetic field that interacts with an oscillating magnetic field to sequentially attract and repel the permanent magnet, thereby expanding and contracting the diaphragm at the deformable membrane. The inlet valve is in fluid communication with the inlet of the diaphragm, and the outlet valve is in fluid communication with the outlet of the diaphragm. The inlet and outlet valves prevent reverse flow of the liquid solution through the oscillating diaphragm pump. In more specific embodiments, the pump includes an upper housing and a lower housing, the upper housing contains the outlet valve and the lower housing contains the inlet valve. At least one of the upper and lower housing includes a support member that circumferentially extends around at least a portion of one or both of the inlet and outlet valves. The support member stiffens one or both of the inlet and outlet valves to reduce back flow. 
     This application claims the benefit of U.S. application Ser. No. 14/092,405, filed 27 Nov. 2013 (the &#39;405 application), now pending. This application also claims the benefit of U.S. application Ser. No. 14/168,338, filed 30 Jan. 2014 (the &#39;338 application), now pending. The &#39;405 application and the &#39;338 application are both hereby incorporated by reference as though fully set forth herein. 
     Specific/Experimental Results 
     Specific/experimental oscillating diaphragm pumps have been developed that are capable of maintaining a flow rate through a valve of the pump at a desired pressure. In various applications, the upper requirement of pumping is 10 mg/sec, as the pump is only “pumping” half the time, (the other half of the time the pump is refilling). In various eCig applications, it is desirable for the flow rate to be established at a low pressure—which minimizes the current (power) draw from a battery source required to drive the magnet back and forth, and thereby power the pump. In various embodiments consistent with the present disclosure, the electromagnetic pump system generates a force of approximately 10 grams. If the cross-sectional area of the pump that is oscillating back and forth is 6 mm 2 , the resulting pressure is approximately 0.5 PSI (pounds per square inch). In such an embodiment, the pump functions at a flow rate of 10 mg/sec, with a pressure that is less than 0.5 PSI. A number of materials and shapes of the valve were tested.  FIG. 8  is a graph with some example testing results—where the x-axis is pump flow rate in mg/sec, and the y-axis is pump pressure in PSI. As shown in  FIG. 8 , many of the oscillating diaphragm pump designs disclosed herein exhibit ideal characteristics—a large flow rate range that maintains a low pump pressure across the flow rate range (e.g., in some embodiments, at or below 0.5 PSI). 
     The deformable membrane of an oscillating diaphragm pump material may comprise Silpak P/N R2128 (a proprietary, low viscosity silicone RTV rubber manufactured by Silpak, Inc.), or a composition including Silpak P/N R2128. In yet other embodiments, the deformable membrane of an oscillating diaphragm pump material may comprise a material or a composition of materials with similar material characteristics to Silpak P/N R2128, such as another silicone rubber composition or other deformable material. The oscillating diaphragm pump including Silpak P/N R2128 (denoted as “Design  3 ” in  FIG. 8 ), as tested, maintained a pressure under 0.5 PSI for a flow rate range between 0-45 mg/s. 
       FIG. 9  is a graph showing the flow rate of an example oscillating diaphragm pump design in response to various input conditions, consistent with the present disclosure. The varying input conditions include varying drive voltages (power), varying pump (oscillation) frequencies (x-axis), and two different diaphragm travel lengths (0.03 inches and 0.05 inches).  FIG. 9  graphs a pump rate in mg/s (y-axis) as a function of these various input conditions, and pump design aspects. As shown in  FIG. 9 , each of the input voltage/diaphragm travel length profiles exhibit similar characteristics. For example, several of the profiles exhibit a max flow rate at approximately 2.5 Hz. It also appears that flow rate is more closely correlated to voltage input then to diaphragm travel length. To achieve higher flow rate, the oscillating diaphragm pump may be driven by higher voltage. Also, the correlation between flow rate and oscillation frequency is greatly reduced beyond 2.5 Hz. Some of the profiles even exhibit reduced flow rate at higher oscillation frequencies (e.g., 15V/0.05″ and 8V/0.05″). 
     Based upon the above discussion and illustrations, those skilled in the art will readily recognize that various modifications and changes may be made to the various embodiments without strictly following the exemplary embodiments and applications illustrated and described herein. For example, components of the oscillating diaphragm pump may be repositioned, relative to one another, to facilitate design requirements for a specific application. Moreover, while aspects of the present disclosure have been presented in the context of oscillating diaphragm pumps, the teachings of the present disclosure may be readily applied, in view of the above, to various other types of pumps. For example, positive displacement pumps—including reciprocating, metering, rotary-type, hydraulic, peristaltic, gear, screw, flexible impeller, piston, progressive cavity pump, among others. Such modifications do not depart from the true spirit and scope of various aspects of the invention, including aspects set forth in the claims. 
     Various modules or other circuits may be implemented to carry out one or more of the operations and activities described herein and/or shown in the figures. In these contexts, a “module” is a circuit that carries out one or more of these or related operations/activities (e.g., controller circuitry). For example, in certain of the above-discussed embodiments, one or more modules are discrete logic circuits or programmable logic circuits configured and arranged for implementing these operations/activities. In certain embodiments, such a programmable circuit is one or more computer circuits programmed to execute a set (or sets) of instructions (and/or configuration data). The instructions (and/or configuration data) can be in the form of firmware or software stored in and accessible from a memory (circuit). As an example, first and second modules include a combination of a CPU hardware-based circuit and a set of instructions in the form of firmware, where the first module includes a first CPU hardware circuit with one set of instructions and the second module includes a second CPU hardware circuit with another set of instructions. 
     Certain embodiments are directed to a computer program product (e.g., nonvolatile memory device), which includes a machine or computer-readable medium having stored thereon instructions which may be executed by controller circuitry (or other electronic device) to perform these operations/activities. 
     It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and features of one embodiment may be employed with other embodiments as the skilled artisan would recognize, even if not explicitly stated herein. Descriptions of well-known components and processing techniques may be omitted so as to not unnecessarily obscure the embodiments of the disclosure. The examples used herein are intended merely to facilitate an understanding of ways in which the disclosure may be practiced and to further enable those of skill in the art to practice the embodiments of the disclosure. Accordingly, the examples and embodiments herein should not be construed as limiting the scope of the disclosure. Moreover, it is noted that like reference numerals represent similar parts throughout the several views of the drawings. 
     The terms “including,” “comprising” and variations thereof, as used in this disclosure, mean “including, but not limited to,” unless expressly specified otherwise. 
     The terms “a,” “an,” and “the,” as used in this disclosure, means “one or more,” unless expressly specified otherwise. 
     Although process steps, method steps, algorithms, or the like, may be described in a sequential order, such processes, methods and algorithms may be configured to work in alternate orders. In other words, any sequence or order of steps that may be described does not necessarily indicate a requirement that the steps be performed in that order. The steps of the processes, methods or algorithms described herein may be performed in any order practical. Further, some steps may be performed simultaneously. 
     When a single device or article is described herein, it will be readily apparent that more than one device or article may be used in place of a single device or article. Similarly, where more than one device or article is described herein, it will be readily apparent that a single device or article may be used in place of the more than one device or article. The functionality or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality or features. 
     LIST OF REFERENCE SIGNS 
     
         
           10  electronic smoking device 
           12  end cap 
           14  power supply portion 
           16  atomizer/liquid reservoir portion 
           18  light-emitting diode (LED) 
           20  air inlets 
           22  battery 
           24  control electronics 
           26  airflow sensor 
           28  atomizer 
           30  heating coil 
           32  wick 
           34  central passage 
           36  liquid reservoir 
           38  air inhalation port 
           200  oscillating diaphragm pump 
           205  housing 
           206  valve 
           210  permanent magnet 
           300  electronic cigarette 
           301  oscillating diaphragm pump 
           305  housing 
           305   A  lower housing 
           305   B  upper housing 
           306   A  outlet valve 
           306   B  inlet valve 
           310  permanent magnet 
           315  electromagnet 
           320   A  upper mount 
           320   B  lower mount 
           321  diaphragm expansion region 
           322  support member 
           328  atomizer chamber 
           336  liquid reservoir 
           300 ′ electronic cigarette 
           305 ′ housing 
           305 ′ A  lower housing 
           305 ′ B  upper housing 
           306 ′ A  outlet valve 
           306 ′ B  inlet valve 
           310 ′ permanent magnet 
           315 ′ electromagnet 
           328 ′ atomizer chamber 
           336 ′ liquid reservoir 
           400  atomizer 
           450  frit 
           451   A-N  solution apertures 
           452   A-B  aerosol exit apertures 
           453   A-N  heating element contact points 
           455  heating element 
           500  atomizer 
           550  frit 
           551   A-N  solution apertures 
           553   A-N  heating element contact points 
           554   A-B  lead wires 
           555  heating element 
           555 ′ heating element 
           555 ″ heating element 
           560  a first heating element portion 
           561  a second heating element portion 
           600  oscillating diaphragm pump 
           610  permanent magnet 
           606   A  outlet valve 
           606   B  inlet valve 
           607  deformable membrane 
           610  permanent magnet 
           620   A  upper mount 
           620   B  lower mount 
           623  oscillator 
           624  inlet chamber 
           625  diaphragm 
           626  outlet chamber 
           627  inner assembly 
           700  oscillating diaphragm pump 
           701  oscillating diaphragm pump 
           702  oscillating diaphragm pump 
           710  permanent magnet 
           706   A  outlet valve 
           706   B  inlet valve 
           707  deformable membrane 
           710  permanent magnet 
           720   A  upper mount 
           720   B  lower mount 
           723  oscillator 
           724  inlet chamber 
           725  diaphragm 
           726  outlet chamber 
           727  inner assembly