Patent Description:
Various systems exist to deliver fluid compositions, such as perfume compositions, into the air by energized (i.e. electrically/battery powered) atomization. In addition, recent attempts have been made to deliver fluid compositions, such as perfume compositions, into the air using microfluidic delivery technology such as thermal and piezo inkjet heads. <CIT> and <CIT> both disclose microfluidic delivery devices for dispersing a liquid component in an air stream.

When using microfluidic delivery technology to deliver fluid compositions, especially when delivering the fluid compositions into the air, proper dispersion of the atomized fluid composition into the surrounding space may be important for consumer noticeably. Moreover, minimizing deposition of the fluid composition on nearby surfaces may also be important.

Some atomizing devices are configured to dispense a fluid composition downward. Such devices may be configured to dispense the fluid composition in a downward or horizontal direction due to requirements on the placement of the microfluidic element. Atomizing a fluid composition into the air in a downward direction can contribute to deposition of the fluid composition on the device itself or on nearby surfaces. Moreover, atomizing a fluid composition downward may not sufficiently disperse the fluid composition in the room or space to provide acceptable consumer noticeability.

As a result, it would be beneficial to provide a device that is capable of atomizing a fluid composition into the air while minimizing deposition of the fluid composition on the device itself. Moreover, it would be beneficial to provide a device that is able to atomize a fluid composition into the air and disperse the fluid composition throughout a room or space.

The present disclosure includes a cartridge for use with a microfluidic delivery device and methods for delivering fluid compositions into the air. The cartridge has a microfluidic delivery member and an air flow channel. The fluid compositions may include various components, including, for example, freshening compositions, malodor reducing compositions, perfume mixtures, and combinations thereof.

The fluid composition may travel in a substantially downward or horizontal direction out of the microfluidic die due to requirements in the placement of the microfluidic die. Microfluidic delivery devices can be vulnerable to the introduction of air into the microfluidic passages, which may render the microfluidic die inoperable. Placement of the microfluidic die substantially below the fluid reservoir or to the side of the fluid reservoir and connecting passages disposed between the reservoir and the microfluidic die may allow air to accumulate in the passages in such a way that the air does not come in contact with the microfluidic die. Conversely, a microfluidic die disposed above the passages (in order to dispense the fluid composition in a substantially upward direction) may come into contact with air bubbles which rise due to buoyancy. Air bubbles may be present in the fluid composition due to dissolution of air in the fluid composition, or through imperfect filling of the microfluidic delivery device.

The cartridge of the present disclosure overcomes challenges that may be associated with dispensing a fluid composition in a horizontal direction or downward direction relative to horizontal. The cartridge may be configured to be releasably connected with a housing of a microfluidic delivery device. The microfluidic delivery device may also include a fan and a power source. The fan is configured to generate air flow that converges with and redirects the fluid composition dispensed from the microfluidic die in an upward direction relative to horizontal. In order to redirect the fluid composition upward, the momentum of the air flow may be greater than the momentum of the fluid composition dispensed from the die at the point where the air flow and the fluid composition converge.

The cartridge includes a reservoir for containing a fluid composition and a microfluidic die in fluid communication with the reservoir. The reservoir may comprise a top surface and a bottom surface separated by a sidewall. The die is configured such that substantially all of the fluid composition exits the microfluidic die in a horizontal direction or downward direction relative to horizontal. The cartridge further includes an air flow channel that extends from the fan to an air outlet of the housing. The air flow channel comprises a first region disposed adjacent to the fan, a second region disposed adjacent to the air outlet, and a third region joining the first and second regions. The second region may be angled upward to the air outlet, relative to horizontal, in order to direct the air flow in a generally upward direction relative to horizontal.

A method of dispensing a fluid composition into the air may include providing a microfluidic delivery device of the present disclosure. The microfluidic delivery device may be plugged into a wall outlet such as an electric source. If plugged into the electrical outlet disposed on a wall, the wall and the outlet may be disposed on a vertical plane. The fluid composition may be jetted from the cartridge into the air in a horizontal direction or downward direction relative to horizontal. The air flow may be directed toward the fluid composition. The air flow may converge with the jetted fluid composition to redirect the fluid composition upward relative to horizontal. The air flow may be travelling with greater momentum than the fluid composition at the point where the air flow and the fluid composition converge in order to change the direction of flow of the fluid composition.

A method of dispensing a fluid composition into the air may include providing a microfluidic delivery device of the present disclosure. The microfluidic delivery device may be powered by a battery or cord such that the microfluidic delivery device rests on a surface. The surface may be disposed on a horizontal plane. The fluid composition may be jetted from the cartridge into the air in a horizontal direction or downward direction relative to horizontal. The horizontal direction may be parallel with the horizontal plane that the microfluidic delivery device rests. The air flow may be directed toward the fluid composition. The air flow may converge with the jetted fluid composition to redirect the fluid composition upward relative to horizontal. The air flow may be travelling with greater momentum than the fluid composition at the point where the air flow and the fluid composition converge in order to change the direction of flow of the fluid composition.

While the below description describes the microfluidic delivery device comprising a housing, a cartridge, and a fan, each having various components, it is to be understood that the microfluidic delivery device is not limited to the construction and arrangement set forth in the following description or illustrated in the drawings. The microfluidic delivery device, cartridge, and fan, of the present disclosure are applicable to other configurations or may be practiced or carried out in various ways. For example, the components of the housing may be located on the cartridge and vice-versa. Further, the housing and cartridge may be configured as a single unit versus constructing a cartridge that is separable and or replaceable from the housing as described in the following description. Moreover, the cartridge may be used with various devices for delivering fluid composition into the air.

While the present disclosure discusses the use of the microfluidic delivery devices <NUM> such as thermal or piezo ink-jet print head type systems, it is to be appreciated that the aspects of the present disclosure are also combinable with other fluid droplet atomizing devices, such as ultrasonic piezo systems with a plurality of nozzles and ultrasonic bath atomizers, and the like. For example, the fan and air flow channel of the present disclosure may be used with other atomizing devices to redirect the atomized fluid composition from travelling in a first direction to a second direction.

With reference to <FIG>, the microfluidic delivery device <NUM> may include a housing <NUM>, a cartridge <NUM> that may be releasably connectable with the housing <NUM>, and a fan <NUM>. The microfluidic delivery device <NUM> may be comprised of an upper portion <NUM>, a lower portion <NUM>, and a body portion <NUM> that extends between and connects the upper portion <NUM> and the lower portion <NUM>.

The microfluidic delivery device may be configured to plug directly into a wall outlet such that the body portion <NUM> is adjacent to a vertical wall. Or, the microfluidic delivery device may be configured with a power cord or battery such that the lower portion <NUM> of the microfluidic delivery device rests on a horizontal surface, such as a table, countertop, desktop, appliance, or the like.

The housing <NUM> may be constructed from a single component or have multiple components that are connected to form the housing <NUM>. The housing <NUM> may be defined by an interior <NUM> and an exterior <NUM>. The housing <NUM> may at least partially contain and/or connect with the cartridge <NUM> and fan <NUM>.

The cartridge <NUM> may be partially or substantially contained within the housing <NUM>, or the cartridge <NUM> may be partially or substantially disposed on and/or connected with the exterior <NUM> of the housing. For example, with reference to <FIG> and <FIG>, the cartridge <NUM> may be disposed at least partially within the housing <NUM> and connected therewith. With reference to <FIG>, at least a portion of the cartridge <NUM> may be disposed on the exterior of the housing <NUM> and connected therewith. The cartridge <NUM> may connect with the housing in various ways. For example, the cartridge may be slideably or rotatably connected with the housing <NUM> using various connector types. The connector may be spring-loaded, compression, snap, or various other connectors.

As will be discussed in further detail below, the cartridge may be configured in various ways. The cartridge <NUM> comprises a reservoir <NUM> for containing a fluid composition <NUM>, a microfluidic die <NUM> that is in fluid communication with the reservoir <NUM>, and electrical contacts <NUM> that connect with electrical contacts <NUM> on the housing <NUM> to deliver power and control signals to the microfluidic die <NUM>. The microfluidic die <NUM> may be configured such that the fluid composition <NUM> is dispensed from the microfluidic die <NUM> in a substantially horizontal direction, substantially vertically downward direction, or generally downward direction, relative to horizontal. For example, with reference to <FIG>, the die <NUM>, and specifically nozzles on the die, may be configured to dispense the fluid composition in a substantially horizontal direction as the fluid composition exits the microfluidic die <NUM>. With reference to <FIG> and <FIG>, the fluid composition may travel in a substantially vertically downward direction out of the microfluidic die <NUM>. In some configurations, such as shown in <FIG>, the fluid composition may travel in a generally downward, angled direction.

As will be discussed further in the microfluidic delivery member section, and with reference to <FIG>, in order for the nozzles on the microfluidic die to dispense the fluid composition in a horizontal or downward direction, the die <NUM>, and specifically the nozzle plate of the die <NUM>, may be vertically oriented or oriented at an angle from horizontal of -<NUM>° to <NUM>° such that the fluid composition is dispensed horizontally or downward, normal to the direction the microfluidic die is disposed. In a configuration where the microfluidic delivery device <NUM> is plugged into an electrical outlet in a vertical wall, the nozzle plate of the die <NUM> may be vertically oriented or oriented at an angle from the wall of -<NUM>° to <NUM>°.

With reference to <FIG> and <FIG>, the fluid composition may exit the microfluidic die <NUM> and travel through a fluid composition outlet <NUM> that is disposed adjacent to the microfluidic die <NUM>. The fluid composition outlet <NUM> may be disposed in the cartridge <NUM> or in the housing <NUM>. However, with reference to <FIG>, it is to be appreciated that in some configurations, the fluid composition may exit the microfluidic die <NUM> and travel directly into the air without passing through a fluid composition outlet.

The microfluidic delivery device <NUM> comprises a fan <NUM> to assist in redirecting the fluid composition from traveling in a generally downward or horizontal direction to travelling in a substantially upward direction relative to horizontal. By redirecting the fluid composition to travel in a substantially upward direction, the fluid composition may be better dispersed throughout a space and deposition of larger droplets on nearby surfaces may be minimized. In order to redirect the fluid composition dispensed from the die, the fluid composition may be dispensed in a first flow path and the air flow from the fan may be configured to travel in a second flow path that converges with the first flow path at a point of convergence C.

With reference to <FIG>, the fan <NUM> may configured to direct air through an air flow channel <NUM> and out an air outlet <NUM> in a generally upward direction. The fluid composition exiting the die <NUM> and the air flow generated by the fan <NUM> may combine either in the air flow channel <NUM> or after the air flow exits the air outlet <NUM>. In either configuration, the air flow from the fan <NUM> converges with and redirects a fluid composition that is flowing in either a substantially horizontal, substantially downward, or substantially vertically downward direction and redirects the fluid composition to flow in a generally upward direction. In order to redirect the fluid composition, the air flow may carry momentum that is greater than the momentum of the flow of the fluid composition at the point where the air flow and the fluid composition converge, the point of convergence C.

With reference to <FIG>, the microfluidic delivery device <NUM> may comprise one or more air inlets <NUM> that are capable of accepting air from the exterior <NUM> of the housing <NUM> to be drawn into the fan <NUM>. The air inlet(s) <NUM> may be positioned upstream of the fan <NUM> or the fan <NUM> may be connected with the air inlet <NUM>. As discussed above, the microfluidic delivery device <NUM> may include one or more air outlets <NUM>. The air outlet(s) <NUM> may be positioned downstream of the fan <NUM>. For reference, and as used herein, air flow travels from upstream to downstream through the air flow channel <NUM>. As will be discussed in more detail below, the fan <NUM> pulls air from the air inlet(s) <NUM> into the housing <NUM> and directs air through an air flow channel <NUM> and out the air outlet(s) <NUM>. The air inlet(s) <NUM> and air outlet(s) <NUM> may have various different dimensions based upon the desired air flow conditions.

The fan <NUM> may be disposed at least partially within the interior <NUM> of the housing <NUM> or the fan <NUM> may be disposed at the exterior <NUM> of the housing <NUM>. Various different types of fans may be used. An exemplary fan <NUM> includes a 5V <NUM> x <NUM> x <NUM> DC axial fan (Series <NUM>, Type255N from EBMPAPST), that is capable of delivering about <NUM> to about <NUM> liters of air per minute ("l/min"), or about <NUM>/min to about <NUM>/min in configurations without flow restrictions placed in the air flow channel, such as a turbulence-reducing screen. In configurations that do include such a flow restriction, the air flow volume may be substantially less, such as about <NUM>/min to about <NUM>/min, alternatively about <NUM>/m to about <NUM>, alternatively <NUM>/m to <NUM>/min. The average air flow velocity, at the point where the fluid composition and air flow converge, may be in the range of about <NUM> meters/second ("m/s") to about <NUM>/s.

The average velocity of the air flow that converges with the fluid composition may be constrained by the dimensions of the flow channel available for changing the direction of travel of the fluid composition. In configurations where the fluid composition travels through the air flow channel <NUM> (such as shown in <FIG> for illustrative purposes only), the average air flow velocity, channel dimension, and fluid composition droplet size must all be arranged such that the droplets of fluid composition enter the air flow and, through aerodynamic drag, simultaneously decelerate and change direction to follow the air flow through the air flow channel. For example, if the average air flow velocity is too high within the air flow channel <NUM>, the droplets exiting the microfluidic die <NUM> will be turned parallel to the flow in the air flow channel <NUM> such that they travel very close or adjacent to the surfaces of the air flow channel. In this case, even small turbulent eddies may cause the drops to collide with and deposit on the surfaces of the air flow channel. For a configuration such as shown in <FIG> for example, the air flow rate may be selected through some combination of empirical observation or mathematically modeling of the aerodynamic behavior of droplets traveling in a crossflow. As used herein, the "average velocity" of the air flow is an average of the velocities across the entire air flow stream since the air flow stream will have lower velocities near the surfaces of the air flow channel and higher velocities in the center of the air flow stream. Likewise, the "average momentum" as used herein is an average of the momentum across the entire the air flow stream.

Momentum is a three-dimensional vector stating the object's momentum in the three directions of three-dimensional space. Momentum is a function of the mass of an object and the velocity of an object, according to the following equation: <MAT> where v is the three-dimensional velocity vector giving the object's rate of movement in each direction and m is the object's mass. Momentum is a vector that gives direction and magnitude of both fluid composition droplets mdvd and air flow mava. As long as the momentum of the fluid composition droplets and the air flow are not in the same direction, the fluid composition direction can be changed. The degree of the fluid composition directional change caused by the air flow is dependent on momentum magnitude and angle between the air flow and flow composition. If the vertical component of air flow momentum is higher than that of the fluid composition momentum and in an upward direct, the fluid composition direction will be changed and moved upward.

In order to push the fluid composition in an upward direction, the lifting drag force Fd of the air flow should be larger than droplet's gravitational force Fg. For horizontally dispensing the fluid composition, the lifting drag force of the air is defined by the following equation: <MAT> Where, ad is the droplet radius; θ is the outlet air flow angle relative to the horizontal direction; µ is the air viscosity that creates the drag force; ua is the magnitude of air flow velocity; ρd is fluid composition density; ρa is air density. For dispensing vertically downward, the lifting drag force of the air is defined by the following equation: <MAT> where ud is the droplet downward velocity. If the fluid composition is dispensed at an arbitrary angle of φ from the vertical down direction, the lifting drag force of the air is defined by the following equation: <MAT> The droplet's gravitational force is defined by the following equation: <MAT> If Fd > Fg, the fluid composition can flow upward.

In one exemplary configuration, the fluid composition may be dispensed downward as droplets with a volume <NUM> pL at an average velocity of <NUM> meters per second ("m/s"), with the air flow channel <NUM> having a cross-sectional area of about <NUM><NUM>, and an average air flow velocity in the range of about <NUM>/s to about <NUM>/s.

In configurations where the fluid composition is directed horizontally and the angle through which the direction of travel must change is small (e.g., on the order of <NUM>-<NUM> degrees), the air flow average velocity may be much higher (e.g., on the order of <NUM>-<NUM>/s). In this configuration, such as shown in <FIG> and <FIG> for illustration only, the droplets travel within a very short channel, or may travel exclusively external to the dispenser, so deposition on surfaces of the air flow channel is not a concern. The air flow velocity in this configuration may be specified to be a higher velocity to maximize the dispersion of droplets within the surroundings, since deposition within the dispenser does not impose a constraint on the upper limit of velocity.

As shown in <FIG>, the air flow channel <NUM> may be disposed in the lower or body portions <NUM> or <NUM> of the microfluidic delivery device <NUM>. The air flow channel <NUM> may be disposed beneath the die <NUM> when the microfluidic delivery device is resting on a surface or plugged into an electrical outlet on a wall. The air flow channel <NUM> may be formed between at least two surfaces of the microfluidic delivery device and may extend from the fan <NUM> to the air outlet <NUM>. The surfaces that form the air flow channel <NUM> may completely or substantially enclose the air flow channel <NUM> except for the fan <NUM> and the air outlet <NUM>. The air flow channel <NUM> may be formed from at least an upper surface <NUM> of the microfluidic delivery device <NUM> and a lower surface <NUM> of the microfluidic delivery device <NUM>. The upper surface and/or lower surface of the housing may be a part of the housing <NUM> or cartridge <NUM> or both. While the device and particularly the air flow channel <NUM> are illustrated as shown in <FIG>, it is appreciated that the air flow channel <NUM> and the surfaces that form the air flow channel <NUM> may be configured in various different ways in order to adjust the flow path, average velocity, turbulence, and any other parameters of the air flow while ultimately delivering an air flow that is capable of redirecting a fluid composition in a generally upward direction.

The air flow channel <NUM> may have a first region <NUM> that is disposed adjacent to the fan <NUM>, a second region <NUM> that is disposed adjacent to the air outlet <NUM>, and a third region <NUM> extending between the first and second end regions <NUM> and <NUM>. At least the second region <NUM> of the air flow channel <NUM> is angled upward toward the air outlet <NUM> and relative to horizontal. The angled portion of the air flow channel <NUM> may form an angle θ from horizontal, from the viewpoint at the exterior of the cartridge. The angle θ of the second region <NUM> of the air flow channel relative to horizontal is shown for purposes of illustration in <FIG>. The third region <NUM> and/or the first region <NUM> may also be angled upward. The upper surface <NUM> and/or lower surface <NUM> may be angled upward toward the air outlet <NUM> in order to angle the air flow channel <NUM> upward in at least the second region <NUM>. As a result, air exiting the air flow channel <NUM> is flowing in a substantially upward direction relative to horizontal. The angle θ may be between <NUM>° and <NUM>°.

The configuration of the air flow channel <NUM> and the air outlet <NUM> can influence the average air velocity, average momentum and direction of the air flow. Specifically, the shape, orientation, and dimensions of the air flow channel <NUM> and the air outlet <NUM> can influence the average velocity, average momentum, and direction of the air flow obtained with the microfluidic delivery device <NUM>. It may desirable to limit the back pressure created in the air flow channel <NUM> and at the air outlet <NUM> in order to maximize the average velocity of the air flow that is achievable with the microfluidic delivery device. The back pressure also cause turbulence or eddies that may impede distribution of the fluid composition in the air. As a result, it may be desirable for the surfaces of the air flow channel <NUM> and the air outlet <NUM> to comprise smooth transitions and minimize sharp turns that may induce turbulence or eddies in the air flow. As discussed above, the air flow channel <NUM>, the air outlet <NUM>, and the fan <NUM> may be designed to produce an average air flow momentum that is greater than the momentum of the fluid composition at the time the air flow and fluid composition converge in order to chance the direction of the fluid composition.

The cross-sectional area of the air outlet <NUM> and the orientation of the air outlet <NUM> can influence the impact that the air flow has on the fluid composition. In one respect, the dimensions and shape of the cross-sectional area of the air outlet <NUM> can influence the average air velocity and the percentage of fluid composition that is redirected by the air flow. One design consideration may be to optimize the orientation of the cross-sectional area of the air outlet <NUM> such that the majority of the air flow contacts the fluid composition. With reference to <FIG> and <FIG>, the air outlet <NUM> may have a circular shaped cross-sectional area and the cross-sectional area of the air outlet <NUM> may be larger than the surface area of the die <NUM> in order to maximize the impact that the air flow has on the fluid composition direction. Comparing the microfluidic delivery device of <FIG> and <FIG> with the microfluidic delivery device <NUM> of <FIG> and <FIG>, it is illustrated in <FIG> and <FIG> that the cross-sectional area of the air outlet is significantly larger than the cross-sectional area of the fluid composition outlet. As a result of a design similar to the microfluidic delivery device of <FIG> and <FIG>, a large portion of the air flow will not contact the fluid composition or impact the movement of the fluid composition. Whereas, the design of a microfluidic delivery device similar to <FIG> and <FIG> will have a larger portion of the air flow contact the fluid composition. As a result of a larger portion of the air flow contacting the fluid composition, the air flow is able to have a larger impact on the directional change of the fluid composition. Stated another way, the fluid composition may be redirected more vertically upward when a majority of the air flow makes direct contact with the fluid composition.

The cross-sectional area of the air outlet <NUM> may be configured with various different shapes. The shape of the cross-sectional area of the air outlet <NUM> may be round, circular, oval, tear-drop shape, triangular, square, rectangular, or any other shape. In order to maximize contact between the air flow and the fluid composition, more of the cross-sectional area should be disposed in the direction where it is desired to move the fluid composition. For example, as illustrated in <FIG>, more of the cross-sectional area of the air outlet <NUM> is disposed horizontally across the channel width W, which is away from the upward direction that the microfluidic delivery device is intended to redirect the fluid composition. As a result, either a more high-powered fan may be used, or the cross-sectional area of the air outlet can be shaped to maximize the impact that the air flow has on the fluid composition. A circular (such as illustrated in <FIG> and <FIG>), vertically oriented rectangular, vertically oriented oval, or tear drop shape for the cross-sectional area of the air outlet <NUM> may maximize the amount of air flow that contacts the fluid composition, and, thus, maximize the vertical movement of the fluid composition upward into the air.

Another design consideration is the angle of the air flow channel <NUM> at and near the air outlet <NUM>. The larger the angle θ between the angled portion of the air flow channel and horizontal, the more vertically upward the air flow can potentially direct the fluid composition. On the other hand, the smaller or less steep of angle in the air flow channel <NUM>, the less vertically upward the air flow can potentially direct the fluid composition. Thus, the travel path of the fluid composition after converging with the air flow is influenced by the angle of the air flow channel <NUM> near the air outlet <NUM>, the shape and dimensions of the cross-sectional area of the air outlet <NUM>.

As discussed above, the air flow and fluid composition may converge after the air flow exits the air outlet <NUM>. In such a configuration, and with reference to <FIG>, the air flow channel <NUM> may be positioned such that the air outlet <NUM> is disposed adjacent to the microfluidic die <NUM> and/or the fluid composition outlet <NUM>. In such a configuration, the air flow exits the air outlet and travels in an upward direction before the air flow converges with the fluid composition dispensed from the microfluidic die <NUM>. Upon converging, the fluid composition is redirected in a generally upward direction, relative to horizontal.

Also discussed above, the air flow and fluid composition may converge within the air flow channel <NUM>. In particular, with reference to <FIG> and <FIG>, the microfluidic die <NUM> may be configured to dispense the fluid composition downward into the air flow channel <NUM>. In such a configuration, air flow in the air flow channel <NUM> directs the fluid composition from the air flow channel <NUM> out the air outlet. When the fluid composition converges with the air flow in the air flow channel <NUM>, the air flow may be travelling in a generally horizontal or upward direction relative to horizontal. In such a configuration, the combined stream of air flow and fluid composition exit the air outlet travelling in a generally upward direction, relative to horizontal.

The channel length L, with reference to <FIG> and <FIG>, may be largely determined by the thickness of the cartridge <NUM>, which may be from about <NUM> to about <NUM>. The channel width W may be from about <NUM> to about <NUM>. The channel height H may be governed by the aerodynamic requirements of directing the droplets through the channel <NUM> with minimal deposition as discussed above, and may be from about <NUM> to about <NUM>. The cross-sectional area of the air flow channel is calculated using the channel width W and the channel height H dimensions. The cross-sectional area of the air flow channel <NUM> may be in the range of about <NUM><NUM> to about <NUM><NUM>, alternatively about <NUM><NUM> to about <NUM><NUM>.

It may be desirable for the air flow to be laminar and without turbulence or eddies in order to precisely control the direction of the fluid composition into the air. This is especially useful when, for example, the fluid composition must travel in the air flow channel <NUM> for some distance before reaching the air outlet. Excessive turbulence or eddies may cause droplets to migrate from the center of the air flow to the surfaces of the air flow channel, thus resulting in deposition within the dispenser. Laminar flow may also improve dispersion of the fluid composition throughout a room or space. Moreover, in a configuration wherein the fluid composition is dispensed into the air flow channel <NUM>, laminar flow may minimize deposition of the fluid composition on the surfaces of the air flow channel <NUM>. The surfaces that form the air flow channel may be configured to maximize laminar flow throughout the entire air flow channel.

With reference to <FIG>, the air flow channel <NUM> may comprise a screen <NUM> with one or more holes <NUM> for restricting the air flow. The screen <NUM> may encourage laminar flow, and, in turn, reduce turbulence and eddies. The screen <NUM> may have holes <NUM> which are sized to reduce the scale of turbulent eddies to a dimension much smaller than the channel height. The size of these openings may be from about <NUM>% to about <NUM>% of the height H of the air flow channel height <NUM>. The screen <NUM> may be positioned in various locations within the air flow channel <NUM>. While a screen is shown in the microfluidic delivery device of <FIG>, it is to be appreciated that the microfluidic delivery device may be configured with or without the screen.

With continuing reference to <FIG>, in a configuration where the fluid composition is dispensed into the air flow channel <NUM>, the upper surface <NUM> in the first and/or third regions <NUM> and <NUM> of the air flow channel <NUM> may include a baffle <NUM> that is configured to direct the air flow away from the fluid composition outlet <NUM> in the housing <NUM>. The baffle <NUM> may allow the fluid composition to jet downward into the air flow channel before the air flow directs the fluid composition through the air flow channel <NUM> and out the air outlet <NUM>. The baffle <NUM> may be disposed adjacent to and upstream from the fluid composition outlet <NUM>. The baffle <NUM> may project into the air flow channel <NUM> and/or may be angled downward toward the lower surface <NUM>. The baffle <NUM> may be configured as a continuous portion of the upper surface <NUM> of the air flow channel <NUM> or as a separate component from the remaining portions of the upper surface <NUM>. While a baffle is shown in the microfluidic delivery device of <FIG>, it is to be appreciated that the microfluidic delivery device may be configured with or without the baffle.

With reference to <FIG>, <FIG>, <FIG>, and <FIG>, a portion of the air flow channel <NUM>, lower surface <NUM>, and/or upper surface <NUM> may jut out horizontally beyond the adjacent body portion <NUM> of the microfluidic delivery device <NUM>. Or, with reference to <FIG> and <FIG>, substantially all of the air flow channel <NUM>, lower surface <NUM>, and/or upper surface <NUM> may be substantially vertically aligned with the fluid composition outlet <NUM> or the microfluidic die <NUM> of the cartridge <NUM>.

In a configuration where the cartridge <NUM> is disposed at least partially within the interior <NUM> of the housing, the housing may include a cover <NUM> such as shown in <FIG> for the purposes of illustration only that opens and closed to provide access to the interior of the housing <NUM> through an opening for inserting and removing the cartridge <NUM>. The cover may be configured in various different ways. The cover may form a substantially air tight connection with the remainder of the housing <NUM> such that pressurized air in the interior <NUM> of the housing <NUM> does not escape through any gaps between the cover <NUM> and the housing. The housing <NUM> may also include opening <NUM> without the cover <NUM>.

The microfluidic delivery device <NUM> is configured to be in electrical communication with a power source. The power source provides power to the microfluidic die <NUM>. The electrical contacts <NUM> on the housing <NUM> connect with the electrical contacts <NUM> on the cartridge. The power source may be located in the interior <NUM> of the housing <NUM>, such as a disposable battery or a rechargeable battery. Or, the power source may be an external power source such as an electrical outlet that connects with an electrical plug <NUM> connected with the housing <NUM>. The housing <NUM> may include an electrical plug that is connectable with an electrical outlet. The microfluidic delivery device may be configured to be compact and easily portable. As such, the power source may include rechargeable or disposable batteries. The microfluidic delivery device may be capable for use with electrical sources as <NUM>-volt batteries, conventional dry cells such as "A", "AA", "AAA", "C", and "D" cells, button cells, watch batteries, solar cells, as well as rechargeable batteries with recharging base. The housing <NUM> may include a power switch on exterior <NUM> of the housing <NUM>.

As discussed above, the cartridge <NUM> may be configured in various different ways. With reference to <FIG> and <FIG>, the cartridge <NUM> may have a vertical axis Y and a horizontal axis X and may comprise a reservoir <NUM> for containing a fluid composition <NUM>.

The reservoir <NUM> may be comprised of a top surface <NUM>, a bottom surface <NUM> opposing the top surface <NUM>, and at least one sidewall <NUM> connected with and extending between the top surface <NUM> and the bottom surface <NUM>. The reservoir <NUM> may define an interior <NUM> and an exterior <NUM>. The reservoir <NUM> may include an air vent <NUM> and a fluid outlet <NUM>. While the reservoir <NUM> is shown as having a top surface <NUM>, a bottom surface <NUM>, and at least one sidewall <NUM>, it is to be appreciated that the reservoir <NUM> may be configured in various different ways.

The reservoir <NUM>, including the top surface <NUM>, bottom surface <NUM>, and sidewall <NUM>, may be configured as a single element or may be configured as separate elements that are joined together. For example, the top surface <NUM> or bottom surface <NUM> may be configured as a separate element from the remainder of the reservoir <NUM>.

The die <NUM> may be disposed on the bottom surface <NUM> or the sidewall <NUM> of the reservoir <NUM>. In either configuration, gravity and/or capillary force may assist in feeding the fluid composition <NUM> to the die.

The reservoir <NUM> may be configured to contain from about <NUM> milliliters (mL) to about <NUM>, alternatively from about <NUM> to about <NUM>, alternatively from about <NUM> to about <NUM> of fluid composition. The cartridge <NUM> may be configured to have multiple reservoirs, with each reservoir containing the same or a different fluid composition.

The reservoir can be made of any suitable material for containing a fluid composition including glass, plastic, metal, or the like. The reservoir may be transparent, translucent, or opaque or any combination thereof. For example, the reservoir may be opaque with a transparent indicator of the level of fluid composition in the reservoir.

With reference to <FIG> and <FIG>, and as discussed above, the air flow channel <NUM> of the microfluidic delivery device <NUM> may be connected with and form a portion of the cartridge <NUM>. The air flow channel <NUM> may adjoin the bottom surface <NUM> of the reservoir <NUM>. The air flow channel <NUM> may be an independent component that is permanently attached with the reservoir <NUM> or the air flow channel <NUM> may be molded as a single component with the reservoir <NUM>. For example, the upper surface <NUM> that forms the air flow channel <NUM> may be a portion of bottom surface <NUM> of the reservoir <NUM> and the lower surface <NUM> may be configured as a separate wall that connected therewith along a portion of the sidewall of the reservoir.

Having the air flow channel connected with the cartridge may be beneficial. For example, depending on the operating conditions, microfluidic die configuration, fluid composition details, and the like, some fluid composition may be deposited onto the surfaces that form the air flow channel. When the air flow channel is connected with a replaceable cartridge, the surfaces that form the air flow channel can be replaced with a clean air flow channel when the fluid composition is depleted form the cartridge.

While it is shown in <FIG> that the microfluidic die <NUM> is disposed on the bottom surface <NUM> of the reservoir <NUM>, it is to be appreciated that the microfluidic die <NUM> may be disposed on the bottom surface <NUM> or the sidewall <NUM> of the reservoir when the air flow channel <NUM> is connected with the reservoir <NUM>.

With reference to <FIG>, the cartridge <NUM> may include a sponge <NUM> disposed within the reservoir <NUM>. The sponge may hold the fluid composition in the reservoir until it the die <NUM> is fired to eject the fluid composition. The sponge may help to create a back pressure to prevent the fluid composition from leaking from the die <NUM> when the die is not being fired. The fluid composition may travel through the sponge and to the die with a combination of gravity force and capillary force acting on the fluid.

The sponge may be in the form of a metal or fabric mesh, open-cell polymer foam, or fibrous or porous wick that contains multiple interconnected open cells that form fluid passages. The sponge material may be selected to be compatible with a perfume composition.

The sponge <NUM> can exhibit an average pore size from about <NUM> microns to about <NUM> microns, alternatively from about <NUM> microns to about <NUM> microns, alternatively about <NUM> microns. The average pore volume of the sponge, expressed as a fraction of the sponge not occupied by the structural composition, is from about <NUM>% to about <NUM>%, alternatively from about <NUM>% to about <NUM>%.

The average pore size of the sponge <NUM> and its surface properties combine to provide a capillary pressure which is balanced by the capillary pressure created by the microfluidic channels in die <NUM>. When these pressures are in balance, the fluid composition is prevented from exiting the die <NUM> due to the tendency to wet the nozzle plate <NUM> or due to the influence of gravity.

With reference to <FIG>, the microfluidic delivery device <NUM> may comprise a microfluidic delivery member <NUM> that utilizes aspects of ink-jet print head systems, and more particularly, aspects of thermal or piezo ink-jet print heads. The microfluidic delivery member <NUM> may be connected with the bottom surface <NUM> and/or sidewall <NUM> of the cartridge <NUM>.

In a "drop-on-demand" ink-jet printing process, a fluid composition is ejected through a very small orifice of a diameter typically about <NUM>-<NUM> microns, or between about <NUM> and about <NUM> microns, in the form of minute droplets by rapid pressure impulses. The rapid pressure impulses are typically generated in the print head by either expansion of a piezoelectric crystal vibrating at a high frequency or volatilization of a volatile composition (e.g. solvent, water, propellant) within the ink by rapid heating cycles. Thermal ink-jet printers employ a heating element within the print head to volatilize a portion of the composition that propels a second portion of fluid composition through the orifice nozzle to form droplets in proportion to the number of on/off cycles for the heating element. The fluid composition is forced out of the nozzle when needed. Conventional ink-jet printers are more particularly described in <CIT> and <CIT>.

The microfluidic delivery member <NUM> may be in electrical communication with the power source of the microfluidic delivery device and may include a printed circuit board ("PCB") <NUM> and a microfluidic die <NUM> that are in fluid communication with the reservoir <NUM>.

The PCB <NUM> may be a rigid planar circuit board, such as shown in <FIG> for illustrative purposes only; a flexible PCB; or a semi-flex PCB, such as shown in <FIG> for illustrative purposes only. The semi-flex PCB shown in <FIG> may include a fiberglass-epoxy composite that is partially milled in a portion that allows a portion of the PCB <NUM> to bend. The milled portion may be milled to a thickness of about <NUM> millimeters. The PCB <NUM> has upper and lower surfaces <NUM> and <NUM>.

The PCB <NUM> may be of a conventional construction. It may comprise a ceramic substrate. It may comprise a fiberglass-epoxy composite substrate material and layers of conductive metal, normally copper, on the top and bottom surfaces. The conductive layers are arranged into conductive paths through an etching process. The conductive paths are protected from mechanical damage and other environmental effects in most areas of the board by a photo-curable polymer layer, often referred to as a solder mask layer. In selected areas, such as the liquid flow paths and wire bond attachment pads, the conductive copper paths are protected by an inert metal layer such as gold. Other material choices could be tin, silver, or other low reactivity, high conductivity metals.

Still referring to <FIG>, the PCB <NUM> may include all electrical connections--the contacts <NUM>, the traces <NUM>, and the contact pads <NUM>. The contacts <NUM> and contact pads <NUM> may be disposed on the same side of the PCB <NUM> as shown in <FIG>, or may be disposed on different sides of the PCB.

With reference to <FIG>, the microfluidic die <NUM> and the contacts <NUM> may be disposed on parallel planes. This allows for a simple, rigid PCB <NUM> construction. The contacts <NUM> and the microfluidic die <NUM> may be disposed on the same side of the PCB <NUM> or may be disposed on opposite sides of the PCB <NUM>.

With continuing reference to <FIG>, the PCB <NUM> may include the electrical contacts <NUM> at the first end and contact pads <NUM> at the second end proximate the microfluidic die <NUM>. <FIG> illustrates the electrical traces <NUM> that extend from the contact pads <NUM> to the electrical contacts and are covered by the solder mask or another dielectric layer. Electrical connections from the microfluidic die <NUM> to the PCB <NUM> may be established by a wire bonding process, where small wires, which may be composed of gold or aluminum, are thermally attached to bond pads on the silicon microfluidic die and to corresponding bond pads on the board. An encapsulant material <NUM>, normally an epoxy compound, is applied to the wire bond area to protect the delicate connections from mechanical damage and other environmental effects.

With reference to <FIG> and <FIG>, the microfluidic delivery member <NUM> may include a filter <NUM>. The filter <NUM> may be disposed on the lower surface <NUM> of the PCB <NUM>. The e filter <NUM> may be configured to prevent at least some of particulates from passing through the opening <NUM> to prevent clogging the nozzles <NUM> of the microfluidic die <NUM>. The filter <NUM> may be configured to block particulates that are greater than one third of the diameter of the nozzles <NUM>. The filter <NUM> may be a stainless steel mesh. The filter <NUM> may be randomly weaved mesh, polypropylene or silicon based.

With reference to <FIG> and <FIG>, the filter <NUM> may be attached to the bottom surface with an adhesive material that is not readily degraded by the fluid composition in the reservoir <NUM>. The adhesive may be thermally or ultraviolet activated. The filter <NUM> is separated from the bottom surface of the microfluidic delivery member <NUM> by a mechanical spacer <NUM>. The mechanical spacer <NUM> creates a gap between the bottom surface <NUM> of the microfluidic delivery member <NUM> and the filter <NUM> proximate the opening <NUM>. The mechanical spacer <NUM> may be a rigid support or an adhesive that conforms to a shape between the filter <NUM> and the microfluidic delivery member <NUM>. In that regard, the outlet of the filter <NUM> is greater than the diameter of the opening <NUM> and is offset therefrom so that a greater surface area of the filter <NUM> can filter fluid composition than would be provided if the filter was attached directly to the bottom surface <NUM> of the microfluidic delivery member <NUM> without the mechanical spacer <NUM>. It is to be appreciated that the mechanical spacer <NUM> allows suitable flow rates through the filter <NUM>. That is, as the filter <NUM> accumulates particles, the filter will not slow down the fluid flowing therethrough. The outlet of the filter <NUM> may be about <NUM><NUM> or larger and the standoff is about <NUM> microns thick.

The opening <NUM> may be formed as an oval, as is illustrated in <FIG>; however, other shapes are contemplated depending on the application. The oval may have the dimensions of a first diameter of about <NUM> and a second diameter of about <NUM> microns. The opening <NUM> exposes sidewalls <NUM> of the PCB <NUM>. If the PCB <NUM> is an FR4 PCB, the bundles of fibers would be exposed by the opening. These sidewalls are susceptible to fluid composition and thus a liner <NUM> is included to cover and protect these sidewalls. If fluid composition enters the sidewalls, the PCB <NUM> could begin to deteriorate, cutting short the life span of this product.

With reference to <FIG>, the PCB <NUM> may carry a microfluidic die <NUM>. The microfluidic die <NUM> comprises a fluid injection system made by using a semiconductor micro fabrication process such as thin-film deposition, passivation, etching, spinning, sputtering, masking, epitaxy growth, wafer/wafer bonding, micro thin-film lamination, curing, dicing, etc. These processes are known in the art to make MEMs devices. The microfluidic die <NUM> may be made from silicon, glass, or a mixture thereof. With reference to <FIG>, the microfluidic die <NUM> comprises a plurality of microfluidic chambers <NUM>, each comprising a corresponding actuation element: heating element or electromechanical actuator. In this way, the microfluidic die's fluid injection system may be micro thermal nucleation (e.g. heating element) or micro mechanical actuation (e.g. thin-film piezoelectric). One type of microfluidic die for the microfluidic delivery member is an integrated membrane of nozzles obtained via MEMs technology as described in <CIT>, assigned to STMicroelectronics S. , Geneva, Switzerland. In the case of a thin-film piezo, the piezoelectric material (e.g. lead zirconinum titanate)" is typically applied via spinning and/or sputtering processes. The semiconductor micro fabrication process allows one to simultaneously make one or thousands of MEMS devices in one batch process (a batch process comprises of multiple mask layers).

With reference to <FIG>, the microfluidic die <NUM> may be secured to the upper surface <NUM> of the PCB <NUM> above the opening <NUM>. The microfluidic die <NUM> may be secured to the upper surface of the PCB <NUM> by any adhesive material configured to hold the semiconductor microfluidic die to the board.

The microfluidic die <NUM> may comprise a silicon substrate, conductive layers, and polymer layers. The silicon substrate forms the supporting structure for the other layers, and contains a channel for delivering fluid composition from the bottom of the microfluidic die to the upper layers. The conductive layers are deposited on the silicon substrate, forming electrical traces with high conductivity and heaters with lower conductivity. The polymer layers form passages, firing chambers, and nozzles <NUM> which define the drop formation geometry.

With reference to <FIG>, the microfluidic die <NUM> includes a substrate <NUM>, a plurality of intermediate layers <NUM>, and a nozzle plate <NUM>. The nozzle plate <NUM> includes an outer surface <NUM>. The plurality of intermediate layers <NUM> include dielectric layers and a chamber layer <NUM> that are positioned between the substrate and the nozzle plate <NUM>. The nozzle plate <NUM> may be about <NUM> microns thick.

As discussed above, and with reference to <FIG>, and <FIG>, in order to dispense the fluid composition in a horizontal or downward direction, the die <NUM>, and specifically the nozzle plate <NUM> of the die <NUM>, may be vertically oriented or oriented at an angle from horizontal of -<NUM>° to <NUM>°. In a configuration where the microfluidic delivery device <NUM> is plugged into an electrical outlet in a wall, the nozzle plate <NUM> of the die <NUM> may be vertically oriented or oriented at an angle from the wall of - <NUM>° to <NUM>°.

With reference to <FIG>, the microfluidic die <NUM> includes a plurality of electrical connection leads <NUM> that extend from one of the intermediate layers <NUM> down to the contact pads <NUM> on the circuit PCB <NUM>. At least one lead couples to a single contact pad <NUM>. Openings <NUM> on the left and right side of the microfluidic die <NUM> provide access to the intermediate layers <NUM> to which the connection leads <NUM> are coupled. The openings <NUM> pass through the nozzle plate <NUM> and chamber layer <NUM> to expose contact pads <NUM> that are formed on the intermediate dielectric layers <NUM>. There may be one opening <NUM> positioned on only one side of the microfluidic die <NUM> such that all of the leads that extend from the microfluidic die extend from one side while other side remains unencumbered by the leads.

With reference to <FIG> and <FIG>, the nozzle plate <NUM> may include about <NUM>-<NUM> nozzles <NUM>, or about <NUM>-<NUM> nozzles, or about <NUM>-<NUM> nozzles. For illustrative purposes only, there are eighteen nozzles <NUM> shown through the nozzle plate <NUM>, nine nozzles on each side of a center line. Each nozzle <NUM> may deliver about <NUM> to about <NUM> picoliters, or about <NUM> to about <NUM> picoliters, or about <NUM> to about <NUM> picoliters of a fluid composition per electrical firing pulse. The volume of fluid composition delivered from each nozzle per electrical firing pulse may be analyzed using image-based drop analysis where strobe illumination is coordinated in time with the production of drops, one example of which is the JetXpert system, available from ImageXpert, Inc. of Nashua, NH, with the droplets measured at a distance of <NUM>-<NUM> from the top of the microfluidic die. The nozzles <NUM> may be positioned about <NUM> to about <NUM> apart. Twenty nozzles <NUM> may be present in a <NUM><NUM> area. The nozzles <NUM> may have a diameter of about <NUM> to about <NUM>, or <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>. <FIG> is a top down isometric view of the microfluidic die <NUM> with the nozzle plate <NUM> removed, such that the chamber layer <NUM> is exposed.

Generally, the nozzles <NUM> are positioned along a fluidic feed channel through the microfluidic die <NUM> as shown in <FIG>. The nozzles <NUM> may include tapered sidewalls such that an upper opening is smaller than a lower opening. The heater may be square, having sides with a length. In one example, the upper diameter is about <NUM> to about <NUM> and the lower diameter is about <NUM> to about <NUM>. At <NUM> for the upper diameter and <NUM> for the lower diameter, this would provide an upper area of <NUM> and a lower area of <NUM>. The ratio of the lower diameter to the upper diameter would be around <NUM> to <NUM>. In addition, the area of the heater to an area of the upper opening would be high, such as greater than <NUM> to <NUM> or greater than <NUM> to <NUM>.

Each nozzle <NUM> is in fluid communication with the fluid composition in the reservoir <NUM> by a fluid path. Referring to <FIG>, <FIG>, <FIG>, the fluid path from the reservoir <NUM> includes through-hole <NUM>, through the opening <NUM> of the PCB <NUM>, through an inlet <NUM> of the microfluidic die <NUM>, through a channel <NUM>, and then through the chamber <NUM> and out of the nozzle <NUM> of the microfluidic die <NUM>.

Proximate each nozzle chamber <NUM> is a heating element <NUM> (see <FIG> and <FIG>) that is electrically coupled to and activated by an electrical signal being provided by one of the contact pads <NUM> of the microfluidic die <NUM>. Referring to <FIG>, each heating element <NUM> is coupled to a first contact <NUM> and a second contact <NUM>. The first contact <NUM> is coupled to a respective one of the contact pads <NUM> on the microfluidic die by a conductive trace <NUM>. The second contact <NUM> is coupled to a ground line <NUM> that is shared with each of the second contacts <NUM> on one side of the microfluidic die. There may be only a single ground line that is shared by contacts on both sides of the microfluidic die. Although <FIG> is illustrated as though all of the features are on a single layer, they may be formed on several stacked layers of dielectric and conductive material. Further, while the illustrated embodiment shows a heating element <NUM> as the activation element, the microfluidic die <NUM> may comprise piezoelectric actuators in each chamber <NUM> to dispense the fluid composition from the microfluidic die.

In use, with reference to <FIG> and <FIG>, when the fluid composition in each of the chambers <NUM> is heated by the heating element <NUM>, the fluid composition vaporizes to create a bubble. The expansion that creates the bubble causes fluid composition to eject from the nozzle <NUM> and to form a plume of one or more droplets.

With reference to <FIG> and <FIG>, the substrate <NUM> includes an inlet path <NUM> coupled to a channel <NUM> that is in fluid communication with individual chambers <NUM>, forming part of the fluid path. Above the chambers <NUM> is the nozzle plate <NUM> that includes the plurality of nozzles <NUM>. Each nozzle <NUM> is above a respective one of the chambers <NUM>. The microfluidic die <NUM> may have any number of chambers and nozzles, including one chamber and nozzle. For illustrative purposes only, the microfluidic die is shown as including eighteen chambers each associated with a respective nozzle. Alternatively, it can have ten nozzles and two chambers provided fluid composition for a group of five nozzles. It is not necessary to have a one-to-one correspondence between the chambers and nozzles.

As best seen in <FIG>, the chamber layer <NUM> defines angled funnel paths <NUM> that feed the fluid composition from the channel <NUM> into the chamber <NUM>. The chamber layer <NUM> is positioned on top of the intermediate layers <NUM>. The chamber layer defines the boundaries of the channels and the plurality of chambers <NUM> associated with each nozzle <NUM>. The chamber layer may be formed separately in a mold and then attached to the substrate. The chamber layer may be formed by depositing, masking, and etching layers on top of the substrate.

With reference to <FIG>, the intermediate layers <NUM> include a first dielectric layer <NUM> and a second dielectric layer <NUM>. The first and second dielectric layers are between the nozzle plate and the substrate. The first dielectric layer <NUM> covers the plurality of first and second contacts <NUM>, <NUM> that are formed on the substrate and covers the heaters <NUM> associated with each chamber. The second dielectric layer <NUM> covers the conductive traces <NUM>.

With reference to <FIG>, the first and second contacts <NUM>, <NUM> are formed on the substrate <NUM>. The heaters <NUM> are formed to overlap with the first and second contacts <NUM>, <NUM> of a respective heater assembly. The contacts <NUM>, <NUM> may be formed of a first metal layer or other conductive material. The heaters <NUM> may be formed of a second metal layer or other conductive material. The heaters <NUM> are thin-film resistors that laterally connect the first and second contacts <NUM>, <NUM>. Instead of being formed directly on a top surface of the contacts, the heaters <NUM> may be coupled to the contacts <NUM>, <NUM> through vias or may be formed below the contacts.

The heater <NUM> may be a <NUM>-nanometer thick tantalum aluminum layer. The heater <NUM> may include chromium silicon films, each having different percentages of chromium and silicon and each being <NUM> nanometers thick. Other materials for the heaters <NUM> may include tantalum silicon nitride and tungsten silicon nitride. The heaters <NUM> may also include a <NUM>-nanometer cap of silicon nitride. The heaters <NUM> may be formed by depositing multiple thin-film layers in succession. A stack of thin-film layers combine the elementary properties of the individual layers.

A ratio of an area of the heater <NUM> to an area of the nozzle <NUM> may be greater than seven to one. The heater <NUM> may be square, with each side having a length <NUM>. The length may be <NUM> microns, <NUM> microns, or <NUM> microns. This would have an area of <NUM>, <NUM>, or <NUM> microns square, respectively. If the nozzle diameter is <NUM> microns, an area at the second end would be <NUM> microns square, giving an approximate ratio of <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM>, respectively.

With reference to <FIG>, a length of the first contact <NUM> can be seen adjacent to the inlet <NUM>. A via <NUM> couples the first contact <NUM> to trace <NUM> that is formed on the first dielectric layer <NUM>. The second dielectric layer <NUM> is on the trace <NUM>. A via <NUM> is formed through the second dielectric layer <NUM> and couples the trace <NUM> to the contact pad <NUM>. A portion of the ground line <NUM> is visible toward an edge <NUM> of the die, between the via <NUM> and the edge <NUM>.

The microfluidic die <NUM> may be relatively simple and free of complex integrated circuitry. This microfluidic die <NUM> will be controlled and driven by an external microcontroller or microprocessor. The external microcontroller or microprocessor may be provided in the housing. This allows the PCB <NUM> and the microfluidic die <NUM> to be simplified and cost effective. There may be two metal or conductive levels formed on the substrate. These conductive levels include the contact <NUM> and the trace <NUM>. All of these features can be formed on a single metal level. This allows the microfluidic die to be simple to manufacture and minimizes the number of layers of dielectric between the heater and the chamber.

With reference to <FIG>, the opening <NUM> of the microfluidic delivery member <NUM> may include a liner <NUM> that covers exposed sidewalls <NUM> of the PCB <NUM>. The liner <NUM> may be any material configured to protect the PCB <NUM> from degradation due to the presence of the fluid composition, such as to prevent fibers of the board from separating. In that regard, the liner <NUM> may protect against particles from the PCB <NUM> entering into the fluid path and blocking the nozzles <NUM>. For instance, the opening <NUM> may be lined with a material that is less reactive to the fluid composition in the reservoir than the material of the PCB <NUM>. In that regard, the PCB <NUM> may be protected as the fluid composition passes therethrough. The through hole may be coated with a metal material, such as gold.

The microfluidic delivery device may include commercially available sensors that respond to environmental stimuli such as light, noise, motion, and/or odor levels in the air. For example, the microfluidic delivery device can be programmed to turn on when it senses light, and/or to turn off when it senses no light. In another example, the microfluidic delivery device can turn on when the sensor senses a person moving into the vicinity of the sensor. Sensors may also be used to monitor the odor levels in the air. The odor sensor can be used to turn-on the microfluidic delivery device, increase the heat or fan speed, and/or step-up the delivery of the fluid composition from the microfluidic delivery device when it is needed.

VOC sensors can be used to measure intensity of perfume from adjacent or remote devices and alter the operational conditions to work synergistically with other perfume devices. For example a remote sensor could detect distance from the emitting device as well as fragrance intensity and then provide feedback to the microfluidic delivery device on where to locate the microfluidic delivery device to maximize room fill and/or provide the "desired" intensity in the room for the user.

The microfluidic delivery devices may communicate with each other and coordinate operations in order to work synergistically with other perfume delivery devices.

The sensor may also be used to measure fluid composition levels in the reservoir or count firing of the heating elements to indicate the cartridge's end-of-life in advance of depletion. In such case, an LED light may turn on to indicate the reservoir needs to be filled or replaced with a new reservoir.

The sensors may be integral with the microfluidic delivery device housing or in a remote location (i.e. physically separated from the microfluidic delivery device housing) such as remote computer or mobile smart device/phone. The sensors may communicate with the microfluidic delivery device remotely via low energy blue tooth, <NUM> low pan radios or any other means of wirelessly communicating with a device and/or a controller (e.g. smart phone or computer).

The user may be able to change the operational condition of the device remotely via low energy blue tooth, or other means.

The cartridge <NUM> may include a memory in order to transmit optimal operational condition to the microfluidic delivery device.

To operate satisfactorily in a microfluidic delivery device, many characteristics of a fluid composition are taken into consideration. Some factors include formulating fluid compositions with viscosities that are optimal to emit from the microfluidic delivery member, formulating fluid compositions with limited amounts or no suspended solids that would clog the microfluidic delivery member, formulating fluid compositions to be sufficiently stable to not dry and clog the microfluidic delivery member, formulating fluid compositions that are not flammable, etc. For adequate dispensing from a microfluidic die, proper atomization and effective delivery of an air freshening or malodor reducing composition may be considered in designing a fluid composition.

The fluid composition may comprise a perfume mixture.

The fluid composition may exhibit a viscosity of less than <NUM> centipoise ("cps"), alternatively less than <NUM> cps, alternatively less than <NUM> cps, alternatively from about <NUM> cps to about <NUM> cps, alternatively about <NUM> cps to about <NUM> cps. And, the fluid composition may have surface tensions below about <NUM>, alternatively from about <NUM> to about <NUM> dynes per centimeter. Viscosity is in cps, as determined using a TA Instrument Rheometer: Model AR-G2 (Discovery HR-<NUM>) with a single gap stainless steel cup and bob under the following conditions:.

The fluid composition may be substantially free of suspended solids or solid particles existing in a mixture wherein particulate matter is dispersed within a liquid matrix. The fluid composition may have less than <NUM> wt. % of suspended solids, alternatively less than <NUM> wt. % of suspended solids, alternatively less than <NUM> wt. % of suspends, alternatively less than <NUM> wt. % of suspended solids, alternatively less than <NUM> wt. % of suspended solids, alternatively less than <NUM> wt. % of suspended solids, or free of suspended solids. Suspended solids are distinguishable from dissolved solids that are characteristic of some perfume materials.

It is contemplated that the fluid composition may comprise other volatile materials in addition to or in substitution for the perfume mixture including, but not limited to, volatile dyes; compositions that function as insecticides or insect repellants; essential oils or materials that act to condition, modify, or otherwise modify the environment (e.g. to assist with sleep, wake, respiratory health, and like conditions); deodorants or malodor control compositions (e.g. odor neutralizing materials such as reactive aldehydes (as disclosed in <CIT>), odor blocking materials, odor masking materials, or sensory modifying materials such as ionones (also disclosed in <CIT>)).

The fluid composition may contain a perfume mixture present in an amount greater than about <NUM>%, by weight of the fluid composition, alternatively greater than about <NUM>%, alternatively greater than about <NUM>%, alternatively greater than about <NUM>%, alternatively greater than about <NUM>%, alternatively from about <NUM>% to about <NUM>%, alternatively from about <NUM>% to about <NUM>%, alternatively from about <NUM>% to about <NUM>%, alternatively from about <NUM>% to about <NUM>%, alternatively from about <NUM>% to about <NUM>%. The fluid composition may consist entirely of the perfume mixture (i.e. <NUM> wt.

The perfume mixture may contain one or more perfume raw materials. The raw perfume materials are selected based on the material's boiling point ("B. referred to herein is the boiling point under normal standard pressure of <NUM> Hg. of many perfume ingredients, at standard <NUM> Hg can be found in "<NPL>. Where the experimentally measured boiling point of individual components is not available, the value may be estimated by the boiling point PhysChem model available from ACD/Labs (Toronto, Ontario, Canada).

The perfume mixture may have a mol-weighted average log of the octanol-water partitioning coefficient ("ClogP") of less than about <NUM>, alternatively less than about <NUM>, alternatively less than about <NUM>. Where the experimentally measured logP of individual components is not available, the value may be estimated by the boiling point PhysChem model available from ACD/Labs (Toronto, Ontario, Canada).

The perfume mixture may have a mol-weighted average B. of less than <NUM>, alternatively less than <NUM>, alternatively less than <NUM>, alternatively less than about <NUM>, or alternatively about <NUM> to about <NUM>.

Alternatively, about <NUM> wt% to about <NUM> wt% of the perfume mixture may have a mol-weighted average B. of less than <NUM>, alternatively about <NUM> wt% to about <NUM> wt% of the perfume mixture has a mol-weighted average B. of less than <NUM>.

For purposes of the present disclosure, the perfume mixture boiling point is determined by the mole-weighted average boiling point of the individual perfume raw materials making up said perfume mixture. Where the boiling point of the individual perfume materials is not known from published experimental data, it is determined by the boiling point PhysChem model available from ACD/Labs.

Table <NUM> lists some non-limiting, exemplary individual perfume materials suitable for the perfume mixture.

Table <NUM> shows an exemplary perfume mixture having a total molar weighted average B. ("mol-weighted average boiling point") less than <NUM>. In calculating the mol-weighted average boiling point, the boiling point of perfume raw materials that may be difficult to determine, may be neglected if they comprise less than <NUM>% by weight of the total perfume mixture, as exemplified in Table <NUM>.

The fluid composition comprises water. The fluid composition may comprise water in an amount from about <NUM> wt. % to about <NUM> wt. % water, alternatively about <NUM> wt. % to about <NUM> wt. % water, alternatively about <NUM>% to about <NUM>% water, alternatively from about <NUM>% to about <NUM>% water, alternatively from about <NUM>% to about <NUM>% water, by weight of the fluid composition. Without wishing to be bound by theory, it has been found that by formulating the perfume mixture to have a mol-weighted average ClogP of less than about <NUM>, water can be incorporated into the fluid composition at a level of about <NUM> wt. % to about <NUM> wt. %, alternatively about <NUM> wt. % to about <NUM> wt. %, by weight of the overall composition.

The fluid composition may contain one or more oxygenated solvent such as a polyol (components comprising more than one hydroxyl functionality), a glycol ether, or a polyether.

Exemplary oxygenated solvents comprising polyols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and/or glycerin. The polyol used in the freshening composition of the present invention may be, for example glycerin, ethylene glycol, propylene glycol, dipropylene glycol.

Exemplary oxygenated solvents comprising polyethers are polyethylene glycol, and polypropylene glycol
Exemplary oxygenated solvents comprising glycol ethers are propylene glycol methyl ether, propylene glycol phenyl ether, propylene glycol methyl ether acetate, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, dipropylene glycol n-propyl ether, ethylene glycol phenyl ether, diethylene glycol n-butyl ether, dipropylene glycol n-butyl ether, diethylene glycol mono butyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, tripropylene glycol n-butyl ether, other glycol ethers, or mixtures thereof. The oxygenated solvent may be ethylene glycol, propylene glycol, or mixtures thereof. The glycol used may be diethylene glycol.

The fluid composition may comprise a perfume mixture, a polyol, and water. In such compositions, it is preferable that the fluid composition comprise from about <NUM> % to about <NUM> %, by weight of the fluid composition, of a perfume mixture, a polyol; and from about <NUM> wt. % to about <NUM> wt. % water, alternatively about <NUM> wt. % to about <NUM> wt. % water, by weight of the fluid composition. Without wishing to be bound by theory, it is believed that the addition of water the fluid composition comprising a perfume mixture reduces the boiling point of the fluid composition, which in turn reduces the energy or heat needed to atomize the fluid composition. As a result of a reduced firing temperature on the heater of the die, it is believed that less fluid composition and less decomposition products of the fluid composition build up on the heater. Moreover, it is believed that water increases the spray rate by dispensing more of the fluid composition in the nozzle at each firing, which results in fewer firings out of each nozzle of the microfluidic die or a reduced number of required nozzles for the desired spray rate, resulting in an increased life to the nozzles. In order to facilitate incorporation of water, the perfume mixture may have a molar weighted average ClogP of less than about <NUM>.

The oxygenated solvent may be added to the composition at a level of from about <NUM> wt. % to about <NUM> wt. %, by weight of the composition, alternatively from about <NUM> wt. % to about <NUM> wt. %, alternatively from about <NUM> wt. % to about <NUM> wt. %, by weight of the overall composition.

The fluid composition may contain functional perfume components ("FPCs"). FPCs are a class of perfume raw materials with evaporation properties that are similar to traditional organic solvents or volatile organic compounds ("VOCs"). "VOCs", as used herein, means volatile organic compounds that have a vapor pressure of greater than <NUM> Hg measured at <NUM> and aid in perfume evaporation. Exemplary VOCs include the following organic solvents: dipropylene glycol methyl ether ("DPM"), <NUM>-methoxy-<NUM>-methyl-<NUM>-butanol ("MMB"), volatile silicone oil, and dipropylene glycol esters of methyl, ethyl, propyl, butyl, ethylene glycol methyl ether, ethylene glycol ethyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, or any VOC under the tradename of Dowanol™ glycol ether. VOCs are commonly used at levels greater than <NUM>% in a fluid composition to aid in perfume evaporation.

The FPCs aid in the evaporation of perfume materials and may provide a hedonic, fragrance benefit. FPCs may be used in relatively large concentrations without negatively impacting perfume character of the overall composition. As such, the fluid composition may be substantially free of VOCs, meaning it has no more than <NUM>%, alternatively no more than <NUM>%, alternatively no more than <NUM>%, alternatively no more than <NUM>%, alternatively no more than <NUM>%, by weight of the composition, of VOCs. The fluid composition may be free of VOCs.

Perfume materials that are suitable as a FPC may have a KI, as defined above, from about <NUM> to about <NUM>, alternatively about <NUM> to about <NUM>, alternatively about <NUM> to about <NUM>, alternatively about <NUM>.

Perfume materials that are suitable for use as a FPC can also be defined using odor detection threshold ("ODT") and non-polarizing scent character for a given perfume character scent camp. ODTs may be determined using a commercial GC equipped with flame ionization and a sniff-port. The GC is calibrated to determine the exact volume of material injected by the syringe, the precise split ratio, and the hydrocarbon response using a hydrocarbon standard of known concentration and chain-length distribution. The air flow rate is accurately measured and, assuming the duration of a human inhalation to last <NUM> seconds, the sampled volume is calculated. Since the precise concentration at the detector at any point in time is known, the mass per volume inhaled is known and concentration of the material can be calculated. To determine whether a material has a threshold below <NUM> ppb, solutions are delivered to the sniff port at the back-calculated concentration. A panelist sniffs the GC effluent and identifies the retention time when odor is noticed. The average across all panelists determines the threshold of noticeability. The necessary amount of analyte is injected onto the column to achieve a <NUM> ppb concentration at the detector. Typical GC parameters for determining ODTs are listed below. The test is conducted according to the guidelines associated with the equipment.

Length <NUM> meters ID <NUM> film thickness <NUM> micron (a polymer layer on the inner wall of the capillary tubing, which provide selective partitioning for separations to occur).

FPCs may have an ODT from greater than about <NUM> parts per billion ("ppb"), alternatively greater than about <NUM> ppb, alternatively greater than about <NUM> ppb, alternatively greater than about <NUM> ppb, alternatively greater than about <NUM> ppb, alternatively greater than about <NUM> parts per million.

The FPCs in a fluid composition may have a KI in the range from about <NUM> to about <NUM>; alternatively from about <NUM> to about <NUM>. These FPCs can be either an ether, an alcohol, an aldehyde, an acetate, a ketone, or mixtures thereof.

FPCs may be volatile, low B. perfume materials. Exemplary FPC include iso-nonyl acetate, dihydro myrcenol (<NUM>-methylene-<NUM>-methyl octan-<NUM>-ol), linalool (<NUM>-hydroxy-<NUM>, <NUM>-dimethyl-<NUM>, <NUM> octadiene), geraniol (<NUM>, <NUM> dimethyl-<NUM>, <NUM>-octadien-<NUM>-ol), d-limonene (<NUM>-methyl-<NUM>-isopropenyl-<NUM>-cyclohexene, benzyl acetate, isopropyl mystristate, and mixtures thereof. Table <NUM> lists the approximate reported values for exemplary properties of certain FPCs.

The total amount of FPCs in the perfume mixture may be greater than about <NUM>%, alternatively greater than about <NUM>%, alternatively greater than about <NUM>%, alternatively greater than about <NUM>%, alternatively greater than about <NUM>%, alternatively from about <NUM>% to about <NUM>%, alternatively from about <NUM>% to about <NUM>%, alternatively from about <NUM>% to about <NUM>%, alternatively from about <NUM>% to about <NUM>%, alternatively from about <NUM>% to about <NUM>%, alternatively from about <NUM>% to about <NUM>%, alternatively from about <NUM>% to about <NUM>%, alternatively about <NUM>%, by weight of the perfume mixture. The perfume mixture may consist entirely of FPCs (i.e. <NUM> wt.

Table <NUM> lists a non-limiting, exemplary fluid composition comprising FPCs and their approximate reported values for KI and B.

When formulating fluid compositions, one may also include solvents, diluents, extenders, fixatives, thickeners, or the like. Non-limiting examples of these materials are ethyl alcohol, carbitol, diethylene glycol, dipropylene glycol, diethyl phthalate, triethyl citrate, isopropyl myristate, ethyl cellulose, and benzyl benzoate.

The microfluidic delivery device <NUM> may be used to deliver a fluid composition into the air. The microfluidic delivery device <NUM> may also be used to deliver a fluid composition into the air for ultimate deposition on one or more surfaces in a space. Exemplary surfaces include hard surfaces such as counters, appliances, floors, and the like. Exemplary surfaces also include carpets, furniture, clothing, bedding, linens, curtains, and the like. The microfluidic delivery device may be used in homes, offices, businesses, open spaces, cars, temporary spaces, and the like. The microfluidic delivery device may be used for freshening, malodor removal, insect repellant, and the like.

It should be understood that every maximum numerical limitation given throughout this specification will include every lower numerical limitation, as if such lower numerical limitations were expressly written herein.

Claim 1:
A microfluidic delivery device (<NUM>) comprising:
a housing (<NUM>);
a cartridge (<NUM>) configured to be releasably connectable with the housing (<NUM>), the cartridge (<NUM>) comprising:
a reservoir (<NUM>) for containing a fluid composition (<NUM>), the reservoir (<NUM>) comprising a top surface (<NUM>), a bottom surface (<NUM>) opposing the top surface (<NUM>), and a sidewall (<NUM>) that joins the top and bottom surfaces; and
a microfluidic die (<NUM>) in fluid communication with the reservoir (<NUM>), wherein the microfluidic die (<NUM>) is configured to dispense substantially all of the fluid composition via a fluid composition outlet (<NUM>) in a horizontal direction or downward direction relative to horizontal;
a fan (<NUM>) creating an air flow; and
an air flow channel (<NUM>) disposed below the reservoir (<NUM>), wherein the air flow channel (<NUM>) extends from the fan (<NUM>) to an air outlet (<NUM>), wherein the air flow channel (<NUM>) comprises a first region disposed adjacent to the fan (<NUM>), a second region disposed adjacent to the air outlet (<NUM>), and a third region joining the first and second regions, wherein at least the second region is angled upward to the air outlet (<NUM>), relative to horizontal-,
characterised in that the air outlet (<NUM>) is disposed adjacent to the microfluidic die (<NUM>) and/or the fluid composition outlet (<NUM>) such that the air flow exits the air outlet (<NUM>) and travels in an upward direction before the air flow converges with the fluid composition (<NUM>) dispensed from the microfluidic die (<NUM>) and upon converging redirects the fluid composition in a generally upward direction, relative to horizontal.