Fluid dispenser device including mechanical actuator to provide vibrational energy

Abstract

A dispenser device may include a fluid ejection device including an ejection chamber including a fluid actuator, a nozzle, a fluid inlet channel fluidically connected to the ejection chamber, the fluid inlet channel having an angle of expansion less than or equal to eighty degrees, and a mechanical actuator to impart an amount of vibrational energy within a predetermined range to the fluid ejection device.

Description

FLUID DISPENSER DEVICE INCLUDING MECHANICAL ACTUATOR TO PROVIDE VIBRATIONAL ENERGYCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to PCT Patent Application No.: PCT / US2023 / 084656, filed December 18, 2023 and PCT Patent Application No. PCT / US2023 / 084662, filed December 18, 2023, which applications are incorporated herein in their entirety.BACKGROUND

[0002] Fluid ejection devices deposit fluid onto a substrate to print in two or three dimensions. Fluid is ejected from a fluid ejection chamber. Fluid is provided to the fluid ejection chamber for ejection. Some fluid dispensing applications call for ejecting aqueous fluids without the use of any other chemical compounds (such as surfactants). Aqueous fluids without chemical compounds such as surfactants may have a surface tension that impedes passage of the aqueous fluids through microfluidic passages into the fluid ejection chamber, preventing ejection from the fluid ejection chamber. While surfactants facilitate passage of fluids through microfluidic passages, surfactants cannot be used in all fluids, or for all dispensing applications.BRIEF DESCRIPTION OF THE DRAWINGS

[0003] FIG. l is a block diagram of an example dispenser device.

[0004] FIG. 2A illustrates a perspective view of an example dispenser device including a solenoid to impact a support structure of the dispenser device.

[0005] FIG. 2B illustrates a side view of the dispenser device of FIG. 2A.

[0006] FIG. 3 illustrates a perspective view of an example dispenser device including an impact structure to directly impact a microfluidic structure of the dispenser device.

[0007] FIG. 4 is a table illustrating example test data for imparting vibrational energy to a microfluidic structure.

[0008] FIG. 5 illustrates an example ejection chamber fluidically connected to an example fluid inlet channel which narrows in width towards the ejection chamber.

[0009] FIG. 6 illustrates an example ejection chamber fluidically connected to an example fluid inlet channel which does not expand in width towards the ejection chamber.

[0010] FIG. 7 illustrates an example ejection chamber which expands in width, the ejection chamber fluidically connected to an example fluid inlet channel which expands in width from a pinch point towards the ejection chamber.

[0011] FIG. 8 illustrates an example ejection chamber fluidically connected to an example fluid inlet channel which expands in width from a pinch point towards the ejection chamber.

[0012] FIG. 9 illustrates a cross section of an example ejection chamber fluidically connected to an example fluid inlet channel.

[0013] FIG. 10 illustrates an example ejection chamber fluidically connected to an example fluid inlet channel including a pillar.

[0014] FIG. 11 illustrates an example ejection chamber fluidically connected to an example fluid inlet channel including multiple pillars.

[0015] FIG. 12 is a block diagram of an example fluid ejection device with a protrusion extending into a fluid passage opening.

[0016] FIG. 13 is a block diagram of an example fluid ejection device with a wall of a fluid inlet channel extending into a fluid passage opening.

[0017] FIG. 14 is a block diagram of an example fluid ejection device with a portion of a pillar extending into a fluid passage opening.

[0018] FIG. 15 illustrates a cross-section of an example fluid ejection device.

[0019] FIG. 16 illustrates a cross-section of an example fluid ejection device including a protrusion extending from a shelf of a chamber layer adjacent a fluid passage opening into the fluid passage opening.

[0020] FIG. 17 illustrates a cross-section of an example fluid ejection device including a protrusion extending from a shelf of the chamber layer across a fluid passage opening.

[0021] FIG. 18 illustrates an example ejection chamber fluidically connected to an example fluid inlet channel with walls of the fluid inlet channel extending into a fluid passage opening.

[0022] FIG. 19 illustrates an array of example ejection chambers fluidically connected to an array of example fluid inlet channels with walls of the fluid inlet channels extending into a fluid passage opening.

[0023] FIG. 20 illustrates an example ejection chamber fluidically connected to an example fluid inlet channel with a pillar between the ejection chamber and a fluid passage opening extending into the fluid passage opening.

[0024] FIG. 21 illustrates a first array of example ejection chambers fluidically connected to a first array of example fluid inlet channels and a second array of example ejection chambers fluidically connected to a second array of example fluid inlet channels with protrusions extending across a fluid passage opening to connect first walls of the first array of fluid inlet channels with second pillars between the fluid passage opening and the second array of ejection chambers and second walls of the second array of fluid inlet channels with first pillars between the fluid passage opening and the first array of ejection chambers.

[0025] FIG. 22 illustrates a first array of example ejection chambers fluidically connected to a first array of example fluid inlet channels and a second array of example ejection chambers fluidically connected to a second array of example fluid inlet channels with protrusionsextending across a fluid passage opening to connect first walls of the first array of fluid inlet channels with second walls of the second array of fluid inlet channels.

[0026] FIG. 23 illustrates a first array of example ejection chambers fluidically connected to a first array of example fluid inlet channels and a second array of example ejection chambers fluidically connected to a second array of example fluid inlet channels with protrusions extending across a fluid passage opening to connect first pillars between the fluid passage opening and the first array of ejection chambers with second pillars between the fluid passage opening and the second array of ejection chambers.

[0027] FIG. 24 illustrates a first array of example ejection chambers fluidically connected to a first array of example fluid inlet channels on a first side of a fluid passage opening and a second array of example ejection chambers fluidically connected to a second array of example fluid inlet channels on a second side of the fluid passage opening with a protrusion extending into the fluid passage opening on a third side of the fluid passage opening.

[0028] FIG. 25 illustrates a first array of example ejection chambers on a first side of a fluid passage opening and a second array of example ejection chambers on a second side of the fluid passage opening with a first protrusion extending into the fluid passage opening on a third side of the fluid passage opening and a second protrusion extending into the fluid passage opening on a fourth side of the fluid passage opening.

[0029] The foregoing and other features of the present disclosure will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that while these drawings depict several examples in accordance with the disclosure, they are, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings.DETAILED DESCRIPTION

[0030] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative examples described in the detailed description, drawings, and claims are not meant to be limiting. Other implementations may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and made part of this disclosure.

[0031] Fluid ejection devices include various components and structures for enabling the flow, storage, processing, and ejection of volumes of fluid. For example, in the context of fluid ejection for printing applications, volumes of marking fluids, such as for forming markings on a substrate (in the context of 2D printing) or building objects on a build plate (in the context of 3D printing), marking fluids may be delivered to an ejection chamber from a storage reservoir through a series of delivery components in varying volumes. In some examples, the volumes may be delivered by applying an external pressure to the fluidic passages through which fluids travel. In other examples, capillary forces may be relied upon to engender fluid flow.

[0032] Ejection of fluid from a fluid ejection chamber may be performed using any number of technologies, including, but not limited to, thermal and piezoelectric actuation. Thermal actuation refers to the use of a mechanism to rapidly heat fluids in the chamber, such as by using a resistor to boil a portion of the fluid and create a cavitation wave. The resulting bubble formation will eject a controlled fluidic droplet via an orifice (e.g., nozzle) of the fluid ejection chamber. Analogously, in the case of a piezoelectric actuator, current may be pulsed through a piezoelectric membrane, which, in turn will impart pressure on the fluid in the ejectionchamber and eject a controlled fluidic droplet via an orifice. It is noted, however, that there are other methods of fluid ejection, and the foregoing is merely provided by way of illustration. It is also noted that ejection from an ejection chamber may refer to both ejection via an orifice and also ejection via a chamber outlet, such as on to a different fluidic passage or chamber.

[0033] In any case, the ability of a fluid ejection device to reliably eject fluidic droplets may be dependent on a fluid carrier, which refers to a component of a fluid mixture that is used to facilitate delivery of components and particles (e.g., pigments in the case of printing, intravenous drugs suspended in aqueous fluids in the case of IVs for healthcare, cells in the case of digital dispense, etc.). Some fluid carriers may be more challenging to eject with reliability.

[0034] In some contexts, there is a desire to cause fluid flow using capillary forces, such as instead of, or in addition to, applying a positive or a negative pressure to a fluid line from an external source (e.g., a pump or a vacuum) to cause fluid to flow. Analogously to the preceding discussion of fluid ejection, a number of factors, including the materials making up a fluid passage, fluid contact angles of a fluid carrier, characteristics of structures (e.g., shape), environmental temperature and barometric levels, etc., contribute to the ability to cause fluid to travel reliably through fluidic passages. Indeed, microfluidic structures may cause a fluid to be pinned before reaching the ejection chamber, preventing dispensing of the fluid. And as shall be discussed in greater detail hereinafter, whether or not a fluid travels through a fluid delivery system reliably using capillary forces depends, among other things, on the ability to keep ejection chambers primed (i.e., supplied with fluid to be ejected). The term “primed,” as used herein, means that the entire surface of the ejection chamber is filled up with or supplied with fluid. “Priming” can facilitate ejection of the fluid from the ejection chamber, such that the ejection chamber is “primed” for firing.

[0035] Fluid can form a meniscus and be pinned (i.e., stuck, prevented from progressing) within structures due to a geometry of the structures. The term “pinned,” as used herein, means that fluid is prevented from efficiently progressing through microfluidic passages. When a fluid is “pinned” within a fluid inlet channel to an ejection chamber, the fluid is unable to reach the ejection chamber. All fluids can be pinned within microfluidic structures dependent upon a geometry of the microfluidic structures, but fluids with higher surface tension are more readily pinned. For example, surfactant-free fluids (e.g., aqueous fluids containing cells for cell-dispensing applications) have higher surface tension and are more readily pinned within structures (e.g., microfluidic channels) than non-aqueous fluids such as fluids containing surfactants. Thus, fluids with higher surface tension can be pinned within structures that do not cause other fluids with lower surface tension to become pinned. In one example, a fluid with a higher surface tension such as an aqueous fluid is pinned within a fluid inlet channel fluidically connected to an ejection chamber. The pinned fluid does not reach the ejection chamber, preventing printing of the fluid using the ejection chamber.

[0036] Structures, such as fluid inlet channels, for printing surfactant-laden liquids generally have geometries that cause aqueous fluids to be pinned. Surfactant-free fluids, such as aqueous fluids, may be used in applications where surfactants are avoided. For example, celldispensing applications call for surfactant-free fluids, as surfactants can damage cell structures. In order to avoid damage to cell structures, cells are suspended in surfactant-free fluids for dispensing of cells. Implementations discussed in the present description propose providing fluid inlet channels and / or protrusions extending from fluid inlet channels that facilitate priming of ejection chambers using capillary forces, allowing for use of some surfactant-free fluids, such as aqueous fluids, in dispensing applications. Implementations discussed in the present description provide for mechanical actuators to provide vibrationalenergy to further facilitate priming of ejection chambers, allowing for use of additional surfactant-free fluids, such as aqueous fluids, in dispensing applications.

[0037] To illustrate these principles, the present description refers, without limitation, to the illustrative example of a digital dispensing device. Various microfluidic applications can be performed by a digital dispensing device. Microfluidic applications, such as dispensing cells suspended in aqueous fluid, call for careful control of amounts of fluid at scales where capillary forces dominate the movement of the fluid. As noted, a dispenser device may utilize a thermal process for dispensing fluid. For successful ejection, fluid needs to reach the thermal resistor inside the ejection chamber. However, microfluidic structures may cause a fluid to be pinned before reaching the ejection chamber, preventing dispensing of the fluid. In order for stable, consistent dispensing of fluids, microfluidic structures are needed that facilitate drawing fluids into ejection chambers and over thermal resistors. In an example, for controlled dispensing of cells suspended in an aqueous fluid, such as for 3D printing of biological material, microfluidic structures that facilitate drawing fluids into ejection chambers and over thermal resistors, as described herein, may be beneficial, such as to avoid pinning.

[0038] This disclosure relates to fluid ejection devices and fluid dispensing devices. Specifically, this disclosure relates to a fluid dispenser device including a mechanical actuator for imparting vibrational energy to microfluidic structures to facilitate flow of liquid through microfluidic passages. The vibrational energy can overcome pinning, or facilitate movement of a liquid through the microfluidic passages to facilitate movement of the liquid into firing chambers (i.e., priming). As discussed herein, liquid (e.g., aqueous liquid) can get stuck (pinned) in the microfluidic passages due to liquid properties and interactions between the liquid and surfaces of the microfluidic passages (e.g., capillary forces, surface tension, etc.). Characteristics of the microfluidic passages such as a geometry of the microfluidic passages(e.g., angle of expansion) and structures extending into the microfluidic passages can facilitate movement of liquids through the microfluidic passages, but may not always result in liquid reaching the firing chambers. To provide energy to the microfluidic passages (and the liquid), a mechanical actuator can provide vibrational energy to the microfluidic structures.

[0039] Vibrational energy imparted to the microfluidic structures facilitates movement of the liquids through the microfluidic passages by improving contact between the liquid and structures extending into the microfluidic passages and by disrupting surface tension of the liquid. An inertia of the liquid can cause the liquid to contact surfaces of the microfluidic passages that move due to the vibrational energy. Fluid actuators can be installed on structures (i.e., deck plate) holding the microfluidic structures to transmit vibrational energy through the structures or directly to the microfluidic structures. One example of a mechanical actuator is solenoid that strikes a deck plate to which a microfluidic cassette is attached. Another example of a mechanical actuator is a solenoid that pushes against a spring-loaded arm which, when released, strikes the microfluidic cassette directly. Various different mechanical actuators can be used in various different configurations to directly or indirectly impart vibrational energy to the microfluidic structures. By providing a predetermined amount of vibrational energy configured to facilitate priming of ejection chambers (i.e., supplying fluid to ejection chambers), the mechanical actuator can facilitate priming of the ejection chambers when fluid would otherwise fail to reach the ejection chambers (e.g., be pinned). Aspects of the disclosure are directed to a dispenser device including a fluid ejection device including an ejection chamber including a fluid actuator, a nozzle, a fluid inlet channel fluidically connected to the ejection chamber, the fluid inlet channel having an angle of expansion less than or equal to eighty degrees, and a mechanical actuator to impart an amount of vibrational energy within a predetermined range to the fluid ejection device.

[0040] FIG. 1 is a block diagram of an example dispenser device 101. The dispenser device101 includes a fluid ejection device 100 and a mechanical actuator 130.

[0041] The fluid ejection device 100 ejects fluid to enable the dispenser device 101 to dispense fluid. The fluid ejection device 100 includes a fluid inlet channel 120 and an ejection chamber 110. The fluid inlet channel 120 is fluidically connected to the ejection chamber 110 to supply fluid to the ejection chamber. The fluid inlet channel 120 may be fluidically connected to a reservoir or fluid passage opening (i.e., opening that fluidically connects the fluid inlet channel 120 to the reservoir). The fluid inlet channel 120 is a microfluidic channel such that microfluidic fluid properties dominate interaction of fluids with the fluid inlet channel 120. The fluid inlet channel 120 has an angle of expansion 122 to facilitate passage of fluid through the fluid inlet channel 120 into the ejection chamber 110, as discussed herein. The angle of expansion 122 defines an angle at which the fluid inlet channel 120 expands to connect to the ejection chamber 110. The angle of expansion 122 can be measured between opposite walls of the fluid inlet channel 120. In some implementations, the fluid inlet channel 120 does not expand along its entire length, and the angle of expansion 122 is measured from a narrowest point of the fluid inlet channel 120. In some implementations, the fluid inlet channel 120 includes a pillar and the angle of expansion 122 is measured between the walls of the fluid inlet channel 120 and the walls of the pillar. In these implementations, the fluid inlet channel 120 includes two effective angles of expansion, where a first angle of expansion is between a first wall of the fluid inlet channel 120 and a first wall of the pillar, and a second angle of expansion is between a second wall of the fluid inlet channel 120 and a second wall of the pillar, as illustrated in FIG. 10. In some implementations, the fluid inlet channel 120 includes multiple pillars, causing the fluid inlet channel 120 to include more than two angles of expansion, as illustrated in FIG. 11. In some implementations, the angle of expansion 122is less than or equal to eighty degrees. In some implementations, the angle of expansion 122 is less than forty or twenty degrees.

[0042] The angle of expansion 122 being less than or equal to eighty degrees renders the dispenser device 101 more efficient, as fluid passes more quickly through the fluid inlet channel 120 into the ejection chamber 110. Faster passage of fluid through the fluid inlet channel 120 to the ejection chamber 110 can allow the dispenser device 101 to dispense fluid more quickly and more efficiently. In an example, the angle of expansion 122 being less than or equal to eighty degrees allows the dispenser device 101 to dispense more drops per minute, with fewer priming failures calling for manual intervention, than similar dispenser devices with fluid inlet channels have angles of expansion greater than eighty degrees. Other mechanisms discussed herein for facilitating priming (e.g., protrusions into a fluid passage opening, mechanical actuators) may also increase an efficiency of the dispenser device 101 and / or separately increase an efficiency of the dispenser device 101. Additional mechanisms for facilitating priming may improve the efficiency of the dispenser device 101 in dispensing particular fluids.

[0043] In an example, a fluid having a lowest surface tension primes efficiently without the use of mechanisms to facilitate priming and the efficiency of the dispenser device 101 in dispensing the fluid having the lowest surface tension is not affected by the use of mechanisms to facilitate priming, a fluid having a low surface tension primes efficiently only with the use of a protrusion into a fluid passage opening, a fluid having a high surface tension primes efficiently only with the use of a protrusion into a fluid passage opening and an angle of expansion of less than or eighty degrees, and a fluid having a highest surface tension only primes efficiently with the use of a protrusion into a fluid passage opening, an angle of expansion of less than or eighty degrees, and a mechanical actuator to provide vibrational energy.

[0044] The ejection chamber 110 ejects fluid from an interior of the ejection chamber 110. The ejection chamber 110 includes a fluid actuator 112 and a nozzle 114. The fluid actuator 112 causes fluid to be ejected from the ejection chamber 110 through the nozzle 114. In an example, the fluid actuator 112 is a thermal resistor that causes cavitation bubbles in the fluid to cause the fluid to be ejected through the nozzle 114.

[0045] The ejection chamber 110 fills with fluid for the fluid ejection device 100 to eject the fluid. The fluid may pass through the fluid inlet channel 120 via capillary forces to fill the ejection chamber 110. To facilitate passage of the fluid into the fluid inlet channel 120 and / or through the fluid inlet channel 120 into the ejection chamber 110, the mechanical actuator 130 imparts vibrational energy to the fluid ejection device. The mechanical actuator 130 can impart vibrational energy to overcome pinning at an interface between a fluid passage opening and the fluid inlet channel 120 as illustrated in FIG. 15. The mechanical actuator 130 can impart vibrational energy to overcome pinning within the fluid inlet channel 120. The vibrational energy can disrupt or prevent formation of a meniscus that can stop passage of fluid into or through the fluid inlet channel (i.e., pinning). The vibrational energy can overcome a surface tension of the fluid and / or increase contact between the fluid and surfaces of the fluid inlet channel to cause the fluid to pass through the fluid inlet channel 120 and into the ejection chamber 110.

[0046] The mechanical actuator 130 can be any actuator to provide the vibrational energy to the fluid ejection device 100. In some implementations, the mechanical actuator 130 is a solenoid. In some implementations, the mechanical actuator 130 is a pneumatic actuator. In some implementations, the mechanical actuator 130 is an electric motor with an eccentric rotating mass (i.e., off-center mass) to produce vibrational energy. In some implementations, the mechanical actuator 130 is a linear resonant actuator motor. In some implementations, the mechanical actuator 130 is a piezoelectric actuator including a piezoelectric material thatchanges shape under voltage to produce vibrational energy. In some implementations, the mechanical actuator 130 is a linear magnetic ram motor including a suspended mass that is driven through a magnetic field to produce vibrational energy. In some implementations, the mechanical actuator 130 is a servo motor that rotates to strike a surface to produce vibrational energy.

[0047] The mechanical actuator 130 can produce the vibrational energy via movement of the mechanical actuator 130 and / or impact on a surface. In some implementations, the mechanical actuator 130 imparts the vibrational energy to a support structure mechanically coupled to the fluid ejection device 100. In an example, the mechanical actuator 130 strikes a deck plate of the dispenser device 101 such that vibrational energy is transferred from the deck plate to the fluid ejection device 100. In an example, the mechanical actuator 130 vibrates such that vibrational energy is transferred into the deck plate and through the deck plate to the fluid ejection device 100.

[0048] In some implementations, the mechanical actuator 130 imparts the vibrational energy directly to the fluid ejection device 100. In an example, the mechanical actuator 130 strikes the fluid ejection device to provide the vibrational energy directly to the fluid ejection device 100. In an example, the mechanical actuator 130 is coupled to the fluid ejection device 100 such that vibration of the mechanical actuator 130 imparts vibrational energy directly to the fluid ejection device 100. In some implementations, a solenoid imparts vibrational energy to a support structure mechanically coupled to the fluid ejection device 100. In some implementations, the a solenoid imparts the amount of vibrational energy directly to the fluid ejection device 100.

[0049] In some implementations, the mechanical actuator 130 accelerates a structure to strike the fluid ejection device 100 to impart the vibrational energy to the fluid ejection device 100. In an example, the dispenser device 101 includes a spring to accelerate the structure to strikethe fluid ejection device 100. In this example, the mechanical actuator 130 includes a solenoid to provide tension to the spring. In this way, relatively slower movement of the solenoid can be used to provide relatively faster movement of the structure by adding tension to the spring.

[0050] The mechanical actuator 130 can impart an amount of vibrational energy within a predetermined range to the fluid ejection device 100. The predetermined range can correspond to an amount of vibrational energy to facilitate movement of fluid through the fluid inlet channel 120. The mechanical actuator 130 can impart different amounts of vibrational energy for different fluid ejection devices and for different fluids. In an example, a first fluid travels through the fluid inlet channel 120 when the mechanical actuator 130 imparts a first amount of vibrational energy to the fluid ejection device 100 and a second fluid travels through the fluid inlet channel 120 when the mechanical actuator 130 imparts a second, greater amount of vibrational energy to the fluid ejection device 100. A lower bound of the predetermined range can be great enough to cause the fluid to pass through the fluid inlet channel 120 and into the ejection chamber 110, and an upper bound of the predetermined range can be low enough to avoid damage to the fluid ejection device 100 and / or splashing / spilling of the fluid.

[0051] The mechanical actuator 130 can impart the amount of vibrational energy to overcome stoppage (i.e., pinning) of fluids in various locations in the fluid ejection device 100. The mechanical actuator 130 can impart vibrational energy to overcome pinning at an interface between a fluid passage opening and the fluid inlet channel 120 as illustrated in FIG. 15. The mechanical actuator 130 can impart vibrational energy to overcome pinning within the fluid inlet channel 120. In some implementations, the mechanical actuator 130 imparts different amounts of vibrational energy (e.g., different ranges of vibrational energy) to the fluid ejection device 100 to overcome pinning in different locations in the fluid ejection device 100. In an example, the mechanical actuator 130 imparts a first amount of vibrational energyto the fluid ejection device 100 to overcome pinning at the interface between the fluid passage opening and the fluid inlet channel 120 and imparts a second amount of vibrational energy to the fluid ejection device 100 to overcome pinning within the fluid inlet channel 120, dependent upon where pinning occurs in the fluid ejection device 100. In an example, the mechanical actuator 130 imparts a first amount of vibrational energy to overcome pinning at the interface between the fluid passage opening and the fluid inlet channel 120 and then imparts a second amount of vibrational energy to overcome pinning within the fluid inlet channel 120.

[0052] In some implementations, the fluid ejection device 100 includes a protrusion extending from the fluid inlet channel 120 into a fluid passage opening fluidically connected to the fluid inlet channel 120, as discussed herein. In some implementations, the fluid ejection device 100 includes a fluid passage opening fluidically connected to the fluid inlet channel 120 and a protrusion extending from the fluid inlet channel 120 into the fluid passage opening, as discussed herein. Examples of protrusions extending into fluid passage openings are illustrated in FIGS. 16-25. The vibrational energy provided by the mechanical actuator 130 can cause the fluid to contact, or increase contact, with the protrusion to facilitate movement of the fluid out of the fluid passage opening and through the fluid inlet channel 120 into the ejection chamber 110.

[0053] FIG. 2A illustrates a perspective view of an example dispenser device 200 including a solenoid 230 to impact a support structure 210 of the dispenser device 200. The dispenser device 200 includes a microfluidic structure 220, otherwise referred to as a “cassette.” The microfluidic structure 220 includes a fluid ejection device including a plurality of fluid inlet channels and ejection chambers. The plurality of fluid inlet channels and ejection chambers can include structures such as those illustrated in FIGS. 5-11 and 18-25. The microfluidic structure 220 receives fluid for ejection using the plurality of ejection chambers. The fluidejection device includes a reservoir that is fluidically connected to the plurality of fluid inlet channels and ejection chambers. Fluid passes through microfluidic channels from the reservoir to the ejection chambers of the fluid ejection device. The solenoid 230 strikes the support structure 210 of the dispenser device 200 to impart vibrational energy to the microfluidic structure 220, the microfluidic channels of the microfluidic structure 220, and the fluid to facilitate passage of the fluid into the ejection chambers of the fluid ejection device. In some implementations, the microfluidic structure includes a plurality of fluid ejection devices each including a reservoir fluidically connected to a plurality of fluid inlet channels and ejection chambers.

[0054] The solenoid 230 strikes the support structure 210 after fluid has been added to the reservoir of the microfluidic structure 220. The solenoid 230 can strike the support structure 210 at a predetermined time after fluid is added to the reservoir of the microfluidic structure 220. In some implementations, the solenoid 230 strikes the support structure 210 in response to a failure of liquid to reach the ejection chambers of the fluid ejection device (i.e., a priming failure). In some implementations, the priming failure can be detected by detecting a failure to eject fluid. In some implementations, the priming failure can be detected using priming sensors that indicate whether ejection chambers are primed (i.e., filled with fluid). The solenoid 230 can strike the support structure 210 based on priming feedback. In an example, the solenoid 230 strikes the support structure 210, fluid ejection is attempted, and the solenoid 230 again strikes the support structure 210 if the fluid ejection failed. In this example, the solenoid 230 strikes the support structure 210 until the fluid ejection is successful. In an example, the solenoid 230 strikes the support structure 210, priming sensors indicate whether priming is successful, and the solenoid 230 again strikes the support structure 210 if the priming failed. In this example, the solenoid 230 strikes the support structure 210 until the priming is successful.

[0055] FIG. 2B illustrates a side view of the dispenser device 200 of FIG. 2A. The dispenser device 200 includes an electronic interface 240 that provides electrical signals to the microfluidic structure 220. The electronic interface 240 provides electrical signals to the microfluidic structure 220 to cause ejection of fluid from the microfluidic structure 220. The electronic interface 240 provides electrical signals to the microfluidic structure 220 to power and control fluid actuators of the microfluidic structure to cause the microfluidic structure 220 to dispense fluid.

[0056] In some implementations, the electronic interface 240 triggers actuation of the solenoid 230. The electronic interface 240 may trigger actuation of the solenoid 230 based on a presence of fluid in a reservoir of the microfluidic structure to facilitate priming of ejection chambers of the microfluidic structure 220. In an example, a user provides (e.g., dispenses, pipettes) fluid to the microfluidic structure 220 and the electronic interface 240 triggers actuation of the solenoid 230 to facilitate movement of the fluid into the ejection chambers of the microfluidic structure 220. In this example, the electronic interface 240 triggers actuation of the solenoid 230 after a predetermined interval of time after the fluid is provided to ensure the fluid travels through the microfluidic structure 220 to either prime the ejection chambers or prevent formation of a meniscus (e.g., at the interface between the fluid passage opening and the fluid inlet channel). In some implementations, the electronic interface 240 triggers actuation of the solenoid 230 in response to the electronic interface 240 coming into electrical contact with the microfluidic structure 220. In some implementations, the electronic interface 240 triggers actuation of the solenoid 230 in response to the electronic interface 240 receiving a signal from a priming sensor of the microfluidic structure that a firing chamber has failed to prime (i.e., does not include liquid).

[0057] While the dispenser device 200 is illustrated as including the solenoid 230, various different types of mechanical actuators can be included in the dispenser device 200, asdiscussed herein. Different types of mechanical actuators can provide different impulses, or vibrational energy having different characteristics. For example, the solenoid 230 provides vibrational energy by striking the support structure 210 and on the return stroke of the solenoid 230 as a plunger of the solenoid 230 is returned to its original position by a spring.

[0058] While the solenoid 230 is illustrated as being positioned to strike the support structure 210, the solenoid 230 can be positioned to strike any portion of the dispenser device 200. Isi, the solenoid 230 can be positioned to strike the microfluidic structure 220 directly. The solenoid 230 can be positioned to strike any point on the microfluidic structure 220. In an example, the solenoid 230 is positioned to strike a top surface of the microfluidic structure 220 along a same direction in which liquid is added to the microfluid structure 220. In an example, the solenoid 230 is positioned to strike a side surface of the microfluidic structure 220 along a direction perpendicular to a direction in which liquid is added to the microfluid structure 220. The amount of force with which the solenoid 230 strikes the support structure 210 or the microfluidic structure 220 is based on where the solenoid 230 is positioned. In an example, the solenoid 230 strikes the support structure 210 with greater force than the microfluidic structure 220 in order to impart the same amount of vibrational energy to the microfluidic structure 220. In an example, the solenoid 230 strikes the support structure 210 at a point farther from the microfluidic structure 220 with greater force than at a point nearer to the microfluidic structure 220 in order to impart the same amount of vibrational energy to the microfluidic structure 220.

[0059] FIG. 3 illustrates a perspective view of an example dispenser device 300 including an impact structure 334 to directly impact a microfluidic structure 320 of the dispenser device 300. The dispenser device 300 includes a support structure 310 to support the microfluidic structure 320, solenoids 330, an arm 332, the impact structure 334, and a guide 336.

[0060] The impact structure 334 strikes the microfluidic structure 320 to impart vibrational energy to the microfluidic structure 320 to facilitate passage of fluid into ejection chambers of the microfluidic structure 320, as discussed herein. The impact structure 334 can include two beams, as illustrated. In some implementations, the impact structure 334 includes one beam. The guide 336 contacts the impact structure 334 to guide movement of the impact structure 334 towards the microfluidic structure 320.

[0061] In some implementations, the guide 336 includes a spring to bias the impact structure 334 towards the microfluidic structure 320. In some implementations, the support structure 310 includes a spring on a same surface of the support structure 310 as the guide 336 or on an opposite surface to bias the impact structure 334 towards the microfluidic structure 320. In some implementations, a resting position of the impact structure 334 is against the microfluidic structure 320. The solenoids 330 push against the arm 332 which is connected to the impact structure 334 to move the arm 332 and the impact structure 334 away from the microfluidic structure 320 and provide tension to the spring. The solenoids 330 release the arm 332 (i.e., cease pushing against the arm 332), allowing the spring to accelerate the impact structure 334 to strike the microfluidic structure 320. In this way, an amount of vibrational force imparted to the microfluidic structure 320 and the fluid ejection device of the microfluidic structure 320 can be controlled by controlling a distance the solenoids 330 push the arm 332 before releasing the arm 332. Different amounts of vibrational energy can be provided to the microfluidic structure 320 based on a fluid provided to the microfluidic structure 320, a geometry of the microfluidic structure 320, and / or whether priming has been successful.

[0062] FIG. 4 is a table 400 illustrating testing results for amounts of vibrational energy imparted to a microfluidic structure using different mechanisms.

[0063]

[0064] The testing results in the table 400 correspond to a microfluidic structure with a fluid which results in a prime success rate of less than 100% in the microfluidic structure absent mechanical delivery of vibrational energy. In the table 400, splashing indicates that the vibrational energy (i.e., impulse) caused the fluid to splash out of a reservoir of the microfluidic structure. Splashing can cause loss of the fluid, reduce a precision of fluid dispensing, and potentially short electrical circuits of the microfluidic structure 220. As shown in the table 400, different magnitudes of impulses (i.e., vibrational energy) cause successful priming and / or splashing.

[0065] The magnitudes included in the table 400 may be composite magnitudes of acceleration in three dimensions. The magnitudes may be relative magnitudes measured by a sensor located on, adjacent, or in the location of, the microfluidic structure. Thus, the magnitudes may not precisely indicate a magnitude of the impulse that reaches the microfluidic passages (e.g., fluid inlet channel) of the microfluidic structure.

[0066] In the table 400, the “stage jitter” corresponds to actuation of stage motors to cause the dispenser device to vibrate. However, as shown in the table 400, neither a stage jitter using motors to move the stage in an X-direction nor a stage jitter using motors to move the stage in a Y-direction causes consistent, successful priming.

[0067] In the table 400, the solenoid measurements correspond to various solenoids with different “throws” (distance traveled by the plunger of the solenoid) that impact the support structure of the dispenser device, such as illustrated in FIGS. 27 and 28. As indicated in the table 400, various throws and voltages can result in successful priming without splashing. The “beam snap” measurements correspond to beams that are accelerated to impact themicrofluidic structure, such as illustrated in FIG. 3. As indicated in the table 400, the beam snap measurements result in successful priming in these tests, while some beam snap measurements cause splashing.

[0068] In some implementations, a predetermined range of magnitudes can be determined for a microfluidic structure corresponding to magnitudes that cause successful priming in the microfluidic structure without causing splashing. In an example, a microfluidic structure is successfully primed without splashing when it receives impulses in the range of 4000-9000 mG. In this example, a 20V solenoid is included in a dispenser device including the microfluidic structure with a throw of 1.5-3.5 mm to provide impulses in the range of 4000- 9000 mG. In some implementations, impulses of different magnitudes can be provided based on a fluid in the microfluidic structure.

[0069] In some implementations, a dispenser device includes multiple mechanical actuators and mechanisms for providing vibrational energy to a microfluidic structure. In an example, a dispenser device includes multiple solenoids to strike a support structure of the dispenser device. In an example, a dispenser device includes a striking solenoid to strike a support structure of the dispenser device and two biasing solenoids to provide tension to a spring to accelerate a beam to strike a microfluidic structure of the dispenser device. In this example, either the striking solenoid or the biasing solenoids are actuated to provide vibrational energy to the microfluidic structure to facilitate priming of ejection chambers of the microfluidic structure.

[0070]

[0071] FIG. 5 illustrates an example ejection chamber 532 fluidically connected to an example fluid inlet channel 536 which narrows in width towards the ejection chamber 532. The ejection chamber 532 includes a fluid actuator 522. The fluid actuator 522 may be aresistor to heat up fluid to eject the fluid out of the ejection chamber 532. In the illustrated example, the direction of fluid ejection is out of the page. A material of the fluid actuator 522 may extend from the ejection chamber 532 into the fluid inlet channel 536. The fluid inlet channel 536 is on a shelf 524 of a fluid ejection device. The fluid inlet channel 536 fluidically connects a fluid passage opening 512 of the fluid ejection device to the ejection chamber 532.

[0072] The fluid inlet channel 536 has a negative angle of expansion, as the fluid inlet channel narrows in width towards the ejection chamber 532. The negative angle of expansion may cause a fluid to prime the ejection chamber 532. The negative angle of expansion may not prevent blowback from the ejection chamber into the fluid inlet channel 536 as effectively as a fluid inlet channel that narrows along a portion of the fluid inlet channel. When the fluid actuator 522 ejects the fluid from the ejection chamber 532, fluid is ejected out of the ejection chamber 532 through a nozzle (in a direction out of the page) and fluid is pushed through the fluid inlet channel 536 away from the ejection chamber 532, which backflow of fluid through the fluid inlet channel 536 is referred to as “blowback.”

[0073] FIG. 6 illustrates an example ejection chamber 632 fluidically connected to an example fluid inlet channel 636 which does not expand in width towards the ejection chamber 632. The ejection chamber 632 includes a fluid actuator 622. The fluid actuator 622 may be a resistor to heat up fluid to eject the fluid out of the ejection chamber 632. In the illustrated example, the direction of fluid ejection is out of the page. A material of the fluid actuator 622 may extend from the ejection chamber 632 into the fluid inlet channel 636. The fluid inlet channel 636 is on a shelf 624 of a fluid ejection device. The fluid inlet channel 636 fluidically connects a fluid passage opening 612 of the fluid ejection device to the ejection chamber 632.

[0074] The fluid inlet channel 636 has an angle of expansion of approximately zero from the narrowest portion of the fluid inlet channel 636 to the width of the ejection chamber 632. The angle of expansion of approximately zero is zero, plus or minus five degrees (0±5°). Theangle of expansion of approximately zero causes the fluid inlet channel 636 to have a constant width the same as a width of the ejection chamber 632 from the narrowest point of the fluid inlet channel 636 to the width of the ejection chamber 632. The angle of expansion of approximately zero may cause a fluid to prime the ejection chamber 632. The angle of expansion of approximately zero may not prevent blowback from the ejection chamber into the fluid inlet channel 636 as effectively as a fluid inlet channel that narrows along a portion of the fluid inlet channel.

[0075] FIG. 7 illustrates an example ejection chamber 732 which expands in width, the ejection chamber 732 fluidically connected to an example fluid inlet channel 736 which expands in width from a pinch point 735 towards the ejection chamber 732. The pinch point 735 is where the fluid inlet channel 736 transitions from narrowing in width towards the ejection chamber 732 to expanding in width towards the ejection chamber 732. The ejection chamber 732 includes a fluid actuator 722. The fluid actuator 722 may be a resistor to heat up fluid to eject the fluid out of the ejection chamber 732. In the illustrated example, the direction of fluid ejection is out of the page. A material of the fluid actuator 722 may extend from the ejection chamber 732 into the fluid inlet channel 736. The fluid inlet channel 736 is on a shelf 724 of a fluid ejection device. The fluid inlet channel 736 fluidically connects a fluid passage opening 712 of the fluid ejection device to the ejection chamber 732.

[0076] The fluid inlet channel 736 has an angle of expansion of about fifteen degrees from the pinch point 735 of the fluid inlet channel 736 to the full width of the ejection chamber 732. In some implementations the ejection chamber 732 expands in width along approximately half of a length of the ejection chamber 732 to the full width of the ejection chamber 732. The expansion in width of the ejection chamber 732 allows for a smaller angle of expansion of the fluid inlet channel 736, as the fluid inlet channel 736 expands from the pinch point 735 to a portion of the full width of the ejection chamber 732.

[0077] The angle of expansion of about fifteen degrees may cause a fluid to prime the ejection chamber 732. In an example, the fluid inlet channel 736 and the ejection chamber 732 have side walls of SU8 such that an aqueous fluid would, according to Expression 1, prime the ejection chamber 732 through the fluid inlet channel 736, as fifteen degrees is less than the twenty degrees for water and SU8 under Expression 1. The pinch point 735 mitigates blowback from the ejection chamber 732.Expression 1 : oc < 2(90° — 0)

[0078] In Expression 1, oc represents the angle of expansion 122 and 9 represents the contact angle between the material of the fluid inlet channel 120 and the fluid. The fluid may be an aqueous fluid. In some implementations, the angle of expansion 122 (oc) may be less than or equal to two to four (2-4) times the difference between the right angle (90°) and the contact angle (9) between a material of the fluid inlet channel and the fluid, dependent upon differences in capillary forces from the top and bottom of the fluid inlet channel 120, part-to- part variation in a fabrication process, and / or contamination. In an example, when the top and bottom of the fluid inlet channel 120 are close enough to contribute capillary forces to prime the ejection chamber, stable priming can be achieved when the angle of expansion 122 is less than or equal to three or four times the difference between the right angle (90°) and the contact angle (9) between a material of the fluid inlet channel and the fluid. In some implementations, the aqueous fluid is any fluid in which the solvent is water.

[0079] FIG. 8 illustrates an example ejection chamber 832 fluidically connected to an example fluid inlet channel 836 which expands in width from a pinch point 835 towards the ejection chamber 832. The ejection chamber 832 includes a fluid actuator 822. The fluid actuator 822 may be a resistor to heat up fluid to eject the fluid out of the ejection chamber 832. In the illustrated example, the direction of fluid ejection is out of the page. A material of the fluid actuator 822 may extend from the ejection chamber 832 into the fluid inlet channel836. The fluid inlet channel 836 is on a shelf 824 of a fluid ejection device. The fluid inlet channel 836 fluidically connects a fluid passage opening 812 of the fluid ejection device to the ejection chamber 832.

[0080] The fluid inlet channel 836 has an angle of expansion of about forty degrees from the pinch point 835 of the fluid inlet channel 836 to the width of the ejection chamber 832. The angle of expansion of about forty degrees may cause a fluid to prime the ejection chamber 832. The angle of expansion of about forty degrees may not follow the inequality set forth in Expression 1. However, as discussed herein, Expression 1 represents a conservative estimate for a maximum angle of expansion, with safety margins for stable priming. The angle of expansion of about forty degrees may be less stable than an angle of expansion following the inequality in Expression 1. As discussed herein, the angle of expansion of about forty degrees may cause the fluid to prime the ejection chamber 832 as the angle of expansion of about forty degrees is less than or equal to two to four times a difference between the right angle and the contact angle between the material of the fluid inlet channel 836 and the aqueous fluid. In an example, if the contact angle is eighty degrees, four times the difference between the right angle of ninety degrees and eighty degrees is forty degrees. The pinch point 835 mitigates blowback from the ejection chamber 832. As the ejection chamber 832 does not narrow in width as the ejection chamber 732 of FIG. 7, the ejection chamber 832 may have a larger area than the ejection chamber 732 of FIG. 7.

[0081] FIG. 9 illustrates a cross section of an example ejection chamber 932 fluidically connected to an example fluid inlet channel 936. The ejection chamber 932 may include and / or be adjacent and fluidically connected to a nozzle 942 in a nozzle layer 940. The ejection chamber 932 may include and / or be adjacent a fluid actuator 922 in an actuator layer 920 of a fluid ejection device including the ejection chamber 932. The actuator layer 920 may be adjacent a substrate layer 910 of the fluid ejection device.

[0082] A top surface of the fluid inlet channel 936 is formed by the nozzle layer 940. A bottom surface of the fluid inlet channel 936 is formed by a thin film 924 in the actuator layer 920. The thin film 924 may overlay the fluid actuator 922. The thin film 924 may form a shelf of the actuator layer 920. The nozzle layer 940 has a continuous material along the length of the fluid inlet channel 936, causing the top surface of the fluid inlet channel 936 to have a continuous surface material. The thin film 924 has a continuous material along the length of the fluid inlet channel 936, causing the bottom surface of the fluid inlet channel 936 to have a continuous surface material. Side walls of the fluid inlet channel 936 have a continuous material along the length of the fluid inlet channel, causing the side surfaces of the fluid inlet channel 936 to have a continuous surface material. Each surface of the fluid inlet channel 936 may have a continuous surface material.

[0083] The surfaces of the fluid inlet channel 936 may have different surface materials. In an example, the thin film 924 is a first material which is a continuous bottom surface material of the fluid inlet channel 936, the nozzle layer 940 is a second material which is a continuous top surface material of the fluid inlet channel 936, and the side walls of the fluid inlet channel 936 are a third material which is a continuous sides surface of the fluid inlet channel 936.

[0084] The nozzle layer 940 and the thin film 924 may be substantially parallel along the length of the fluid inlet channel 936. The ceiling (formed by the nozzle layer 940) and the floor (formed by the thin film 924) of the fluid inlet channel 936 may have minimal topographical changes. The ceiling and floor of the fluid inlet channel 936 may be continuous surfaces, uninterrupted by shelfs, edges, turns, or other topographical changes. The fluid inlet channel 936 may have a constant height along the length of the fluid inlet channel 936. The constant height of the fluid inlet channel 936 may facilitate priming of the ejection chamber 932. Expansion in the height of the fluid inlet channel 936 may prevent priming and cause a fluid to be pinned in the fluid inlet channel 936. In an example, an additional layer of materialon the thin film 924 which ends in the fluid inlet channel 936, resulting in a shelf (e.g., 90- degree edge) from the additional layer to the thin film 924 (an angle of expansion of ninety degrees) may cause a fluid to be pinned in the fluid inlet channel 936. In an example, an additional layer on the thin film 924 of four pm with an angle of expansion of approximately ninety degrees from the additional layer to the thin film 924 can cause a fluid to be pinned in the fluid inlet channel 936. In an example, an additional layer on the thin film 924 of half a micron with an angle of expansion of approximately ninety degrees from the additional layer to the thin film 924 can cause a fluid to be pinned in the fluid inlet channel 936.

[0085] To facilitate priming of the ejection chamber 932, the fluid inlet channel 936 has continuous surface materials and / or a constant or narrowing height along the length of the fluid inlet channel 936. The thin film 924 can be raised above the fluid actuator 922, causing the height of the fluid inlet channel 936 to be reduced where the fluid actuator 922 extends beyond the ejection chamber 932 into the fluid inlet channel 936. In some examples, the thin film 924 includes a bevel where the thin film 924 is raised over the fluid actuator 922. The point on the thin film 924 in the fluid inlet channel 936 where the thin film 924 extends over the fluid actuator 922 may be referred to as a “threshold” of the fluid actuator 922. In some examples, a structure extending from within the fluid inlet channel 936 over the threshold of the fluid actuator 922 can facilitate priming of the ejection chamber 932, as illustrated in FIG. 10.

[0086] FIG. 10 illustrates an example ejection chamber 1032 fluidically connected to an example fluid inlet channel 1036 including a pillar 1034. The ejection chamber 1032 includes a fluid actuator 1022. The fluid actuator 1022 may be a resistor to heat up fluid to eject the fluid out of the ejection chamber 1032. In the illustrated example, the direction of fluid ejection is out of the page. A material of the fluid actuator 1022 may extend from the ejection chamber 1032 into the fluid inlet channel 1036. The fluid inlet channel 1036 is on a shelf1024 of a fluid ejection device. The fluid inlet channel 1036 fluidically connects a fluid passage opening 1012 of the fluid ejection device to the ejection chamber 1032.

[0087] The fluid inlet channel 1036 has an angle of expansion of about thirty degrees from the pinch point 1035 of the fluid inlet channel 1036 to the width of the ejection chamber 1032 on either side of the pillar 1034. The pillar 1034 may serve to reduce the angle of expansion by providing additional surfaces between the side walls of the fluid inlet channel 1036 such that portions of the fluid inlet channel formed on opposite sides of the pillar 1034 have a smaller angle of expansion than measured between the side walls of the fluid inlet channel 1036. The pillar 1034 reduces the effective width of the fluid inlet channel 1036, increasing capillary forces drawing the fluid through the fluid inlet channel 1036 and into the ejection chamber 1032 and facilitating priming of the ejection chamber 1032. In an example, the fluid inlet channel 1036 has an angle of expansion of about forty degrees as measured between side walls of the fluid inlet channel 1036 and angles of expansion of about thirty degrees as measured between the side walls of the fluid inlet channel and the pillar 1034. As fluid contacts the side walls of the fluid inlet channel 1036 and the pillar 1034, priming of the ejection chamber 1032 is facilitated by the angles of expansion as measured between the side walls of the fluid inlet channel and the pillar 1034. The pillar 1034 is illustrated as having equal angles of expansion on either side of the pillar 1034, but different angles of expansion can be present on different sides of the pillar 1034.

[0088] The pillar 1034 includes a leading edge towards the fluid passage opening 1012 and a trailing edge towards the ejection chamber 1032. The trailing edge extends along the fluid inlet channel 1036 from the pinch point 1035 toward the ejection chamber 1032. In some implementations, the leading edge of the pillar 1034 extends into the ejection chamber 1032. In some implementations, the leading edge of the pillar 1034 extends over a threshold 1023 of the fluid actuator 1022. The trailing edge of the pillar 1034 extending over the threshold1023 of the fluid actuator 1022 and / or extending into the ejection chamber 1032 facilitates priming of the ejection chamber 1032. The threshold 1023 is a point in the fluid inlet channel 1036 to which the fluid actuator 1022 extends, resulting in a slight change in topography in the floor of the fluid inlet channel 1036. The trailing edge of the pillar 1034 extending over the threshold 1023 and corresponding topographical change in the fluid inlet channel 1036 facilitates priming of the ejection chamber 1032.

[0089] The pillar 1034 may have a diamond-shaped cross-section, as illustrated in FIG. 10. The diamond-shaped cross-section prevents pinning of fluids on the pillar 1034 by allowing for a gradual angle of expansion on the trailing edge of the pillar 1034. As discussed herein, the pillar 1034 includes a widening portion on the leading edge of the pillar 1034 and a tapering portion on the trailing edge of the pillar 1034. An angle of pillar narrowing of the tapering portion on the trailing edge of the pillar 1034 affects the angle of expansion of the fluid inlet channel 1036 from the pinch point 1035 to the ejection chamber 1032. In some implementations, the angle of pillar narrowing is five to thirty degrees. In an example, the angle of pillar narrowing is ten degrees. In an example, the angle of pillar narrowing is fifteen degrees. In an example, the angle of pillar narrowing is twenty degrees.

[0090] The angle of expansion of about thirty degrees may cause a fluid to prime the ejection chamber 1032, dependent upon interactions between the fluid and the surface materials of the fluid inlet channel 1036 and / or the pillar 1034. The pinch point 1035 and the pillar 1034 mitigate blowback from the ejection chamber 1032. The pillar 1034 reduces blowback by serving as an obstacle within the fluid inlet channel 1036 which resists blowback.

[0091] FIG. 11 illustrates an example ejection chamber 1132 fluidically connected to an example fluid inlet channel 1036 including a first pillar 1134a and a second pillar 1134b, referred to collectively herein as pillars 1134. The ejection chamber 1132 includes a fluid actuator 1122. The fluid actuator 1122 may be a resistor to heat up fluid to eject the fluid outof the ejection chamber 1132. In the illustrated example, the direction of fluid ejection is out of the page. A material of the fluid actuator 1122 may extend from the ejection chamber 1132 into the fluid inlet channel 1136. The fluid inlet channel 1136 is on a shelf 1124 of a fluid ejection device. The fluid inlet channel 1136 fluidically connects a fluid passage opening 1112 of the fluid ejection device to the ejection chamber 1132.

[0092] The fluid inlet channel 1136 has an angle of expansion of about twenty-five degrees from the pinch point 1135 of the fluid inlet channel 1136 to the width of the ejection chamber 1132 between a left side wall of the fluid inlet channel 1136 and a left side of the first pillar 1134a, between a right side of the first pillar 1134a and a left side of the second pillar 1134b, and between a right side of the second pillar 1134b and a right side wall of the fluid inlet channel 1136. The pillars 1134 serve to reduce the angle of expansion by providing additional surfaces between the side walls of the fluid inlet channel 1136 such that portions of the fluid inlet channel 1136 formed between the pillars 1134 and between the pillars 1134 and the side walls of the fluid inlet channel 1136 have a smaller angle of expansion than measured between the side walls of the fluid inlet channel 1136. In an example, the fluid inlet channel 1136 has an angle of expansion of about forty degrees as measured between side walls of the fluid inlet channel 1136 and angles of expansion of about twenty-five degrees as measured between the side walls of the fluid inlet channel 1136 and the pillars 1134 and between the pillars 1134. As fluid contacts the side walls of the fluid inlet channel 1136 and the pillars 1134, priming of the ejection chamber 1132 is facilitated by the angles of expansion as measured between the side walls of the fluid inlet channel and the pillars 1134 and between the pillars 1134. The pillars 1134 are illustrated as having equal angles of expansion on opposite sides of the pillars 1134 and between the pillars, but different angles of expansion may be present on different sides of the pillars 1134 and / or between the pillars 1134. While the pillars 1134 are illustrated as being located at a same location along the length of the fluid inlet channel, the pillars 1134may be at different locations along the length of the fluid inlet channel. While two pillars are illustrated, any number of pillars may be present in the fluid inlet channel 1136.

[0093] The pillars 1134 each include a leading edge towards the fluid passage opening 1112 and a trailing edge towards the ejection chamber 1132, as described herein.

[0094] In some examples, the ejection chamber 1132 has a width of about 53 pm and a length of about 52 pm. In some examples, the fluid inlet channel 1136 has a width of about 70 pm at its widest point (inlet). In some examples, the fluid inlet channel 1136 has a width of about 40 pm at its narrowest point (the pinch point 1135). In some examples, the pillars 1134 have a width of about 7 pm at their widest point. In some examples, the pillars 1134 have a length of about 26.5 pm.

[0095] In some examples, the fluid inlet channel 120 can have a channel height from 2 pm to 100 pm, or from 5 pm to 80 pm, or from 10 pm to 50 pm, or from 10 pm to 30 pm, or from 10 pm to 20 pm, or from 20 pm to 50 pm, or from 20 pm to 80 pm. In some examples, the fluid inlet channel 120 can have a width from 5 pm to 200 pm, or from 10 pm to 150 pm, or from 10 pm to 100 pm, or from 10 pm to 80 pm, or from 15 pm to 60 pm, or from 20 pm to 45 pm, or from 20 pm to 100 pm.

[0096] A dispenser device can include a microfluidic structure including an ejection chamber including a fluid actuator, a fluid inlet channel fluidically connected to the ejection chamber, the fluid inlet channel having an angle of expansion less than or equal to eighty degrees, a fluid passage opening fluidically connected to the fluid inlet channel, a protrusion extending from the fluid inlet channel into the fluid passage opening, and a mechanical actuator to impart an amount of vibrational energy within a predetermined range to the fluid inlet channel. The amount of vibrational energy within the predetermined range facilitates movement of an aqueous fluid from the fluid passage opening into the ejection chamber, asdiscussed herein. Examples of microfluidic structures including protrusions extending into fluid passage openings are illustrated in FIGS. 12-25. The mechanical actuator may be a solenoid, such as illustrated in FIGS. 2-3. In some implementations, the solenoid imparts vibrational energy to a support structure mechanically coupled to the fluid inlet channel, as illustrated in FIGS. 2 A and 2B. In some implementations, the mechanical actuator includes a spring to accelerate a structure to provide vibrational energy, as illustrated in FIG. 3. In some implementations, the dispenser device includes a solenoid to provide tension to the spring, as illustrated in FIG. 3. The structure accelerates to strike a support structure mechanically coupled to the fluid inlet channel to impart the amount of vibrational energy to the fluid inlet channel, as illustrated in FIG. 3.

[0097] FIG. 12 is a block diagram of an example fluid ejection device 1200 with a protrusion 1234 extending into a fluid passage opening 1212. The fluid passage opening 1212 is fluidically connected to a chamber layer 1230. The chamber layer 1230 is a layer of the fluid ejection device 1200 (e.g., layer formed using lithography) that includes an ejection chamber 1232. A floor of the ejection chamber 1232 includes a fluid actuator in an actuator layer 1220 adjacent the chamber layer 1230. The fluid ejection device 1200 includes a nozzle orifice 1242 fluidically connected to the ejection chamber 1232. The fluid ejection device 1200 includes a protrusion in the chamber layer 1230 extending from a shelf 1224 of the chamber layer adjacent the fluid passage opening 1212 into the fluid passage opening 1212. The shelf 1224 is a surface of the chamber layer 1230 adjacent the fluid passage opening 1212. In some implementations, the shelf 1224 is a surface of the chamber layer 1230 that extends parallel to the fluid actuator 1222 in the actuator layer 1220.

[0098] The ejection chamber 1232 may be referred to as a firing chamber. The ejection chamber 1232 may be configured to receive fluid and eject the fluid using the fluid actuator 1222 through the nozzle orifice 1242. The ejection chamber 1232 may be referred to as“primed” when the ejection chamber 1232 contains fluid to be ejected. “Priming” the ejection chamber 1232 may refer to the process of filling the ejection chamber 1232 with fluid to be ejected. The ejection chamber 1232 may be sized to receive an amount of fluid such that the fluid actuator 1222 ejects a predetermined amount of fluid. The ejection chamber 1232 may have any shape. In an example, the ejection chamber 1232 is roughly square-shaped. In an example, the ejection chamber 1232 is roughly circular. The ejection chamber 1232 may be formed using a lithographic process. In an example, the ejection chamber 1232 is formed using SU8 or other photoresist material in a layered structure.

[0099] The fluid actuator 1222 may be a thermal, mechanical, electrical, and / or electromechanical actuator. In an example, the fluid actuator 1222 is a resistor which boils the fluid to eject the fluid through the nozzle orifice 1242. In some examples, the fluid actuator 1222 is a thermal resistor. A thermal resistor can be used as a heater to heat liquid in the ejection chamber 1232 and / or a fluid inlet channel fluidically connecting the ejection chamber 1232 and the fluid passage opening 1212, or as a bubble generator to generate vapor bubbles to eject droplets of liquid from an ejection nozzle or to pump liquid through the fluid inlet channel. In an example, the fluid actuator 1222 is a piezoelectric actuator.

[0100] The nozzle orifice 1242 may be referred to as a nozzle, ejection opening, orifice, or ejection orifice. The nozzle orifice 1242 may shape and / or direct jets or drops of fluid which are directed from the ejection chamber 1232. The nozzle orifice 1242 may be at a top (ceiling) of the ejection chamber 1232 and the fluid actuator 1222 may be at a bottom (floor) of the ejection chamber 1232. The terms “top,” “bottom,” “floor,” and “ceiling” are used for ease of understanding and do not limit the orientation of the ejection chamber 1232. The ejection chamber 1232 may be oriented in any direction.

[0101] The shelf 1224 may be a portion of the chamber layer 1230 and / or the actuator layer1220. In an example, the chamber layer 1230 is adjacent the actuator layer 1220 and the shelfis a surface of the actuator layer 1220 adjacent the chamber layer 1230. The shelf 1224 may form a “floor” of the chamber layer 1230. The shelf 1224 may form a portion of the floor of the chamber layer 1230 adjacent the fluid passage opening 1212. The shelf 1224 may be a surface to which side walls of the ejection chamber 1232 are attached. The shelf 1224 may be a surface to which side walls of a fluid inlet channel fluidically connecting the ejection chamber 1232 to the fluid passage opening 1212 are attached.

[0102] In some implementations, a first portion of the protrusion 1234 extends within the chamber layer 1230 into the fluid passage opening 1212 and a second portion of the protrusion 1234 extends into a substrate layer of the fluid ejection device 1200 through the fluid passage opening 1212. The first portion and the second portion of the protrusion 1234 may be substantially perpendicular to one another. The first portion of the protrusion 1234 may extend within a plane of the chamber layer 1230 while the second portion of the protrusion 1234 may extend beyond the plane of the chamber layer 1230 into the actuator layer 1220 and / or the substrate layer. Extending “within the plane of the chamber layer” may refer to the protrusion 1234 remaining within the bounds of the chamber layer 1230. In an example, in a layered structure including the chamber layer 1230, the protrusion 1234 may extend within the plane of the chamber layer, not into adjacent layers. In some examples, the second portion of the protrusion 1234 may extend a portion of a height of the actuator layer 1220 into the fluid passage opening 1212. In some examples, the protrusion 1234 includes the first portion and extends within the chamber layer into the fluid passage opening 1212. The substrate layer may be adjacent the actuator layer 1220 and / or attached to the actuator layer 1220 by an adhesive layer between the substrate layer and the actuator layer 1220. The actuator layer 1220 may be between the substrate layer and the chamber layer 1230. In some implementations, the first portion of the protrusion extends from a top of the chamber layer1230 to a bottom of the chamber layer 1230. The first portion of the protrusion may extend along an entire height of the chamber layer 1230.

[0103] In some implementations, the protrusion 1234 includes a leading edge extending into the fluid passage opening 1212 and a trailing edge facing the ejection chamber 1232, the trailing edge configured to reduce an angle of expansion of a fluid inlet channel. The fluid inlet channel may fluidically connect the ejection chamber 1232 and the fluid passage opening 1212. The leading edge may be positioned such that fluid from the fluid passage opening 1212 contacts the leading edge before contacting the trailing edge. The trailing edge may reduce the angle of expansion of the fluid inlet channel to facilitate priming of the ejection chamber 1232. The trailing edge may reduce an effective width of the fluid inlet channel to facilitate priming of the ejection chamber 1232.

[0104] In some implementations, the protrusion 1234 extends from a first side of the fluid passage opening 1212 into the fluid passage opening 1212 and the ejection chamber 1232 is on a second side of the fluid passage opening 1212. The protrusion 1234 and the ejection chamber 1232 may be on opposite sides of the fluid passage opening 1212. The protrusion 1234 and the ejection chamber 1232 may be on adjacent sides of the fluid passage opening 1212.

[0105] In some implementations, the chamber layer 1230 includes a first array of ejection chambers on a first side of the fluid passage opening 1212 and a second array of ejection chambers on a second side of the fluid passage opening 1212 opposite the first side. The protrusion 1234 may extend into the fluid passage opening 1212 from a third side of the fluid passage opening 1212. In an example, arrays of ejection chambers are on opposite sides of the fluid passage opening 1212 and protrusions are on other opposite sides of the fluid passage opening 1212.

[0106] In some implementations, the protrusion 1234 extends across a width of the fluid passage opening 1212. The protrusion 1234 may extend beyond the chamber layer 1230 into the actuator layer 1220 and / or a substrate layer as well as across the width of the fluid passage opening 1212. A first portion of the protrusion 1234 may be on the shelf 1224 within the chamber layer 1230 and a second portion of the protrusion 1234 may extend across the width of the fluid passage opening 1212 and beyond the chamber layer 1230 into the actuator layer 1220 and / or a substrate layer. In some implementations, the protrusion 1234 connects (across the fluid passage opening 1212) a first wall of a first fluid inlet channel of a first ejection chamber to a second wall of a second fluid inlet channel of a second ejection chamber.

[0107] In some implementations, the protrusion 1234 is formed as a wall of a fluid inlet channel, as a pillar, or as a bridge connecting a wall and / or a pillar.

[0108] In some implementations, the fluid passage opening 1212 is fluidically connected to a reservoir containing fluid. The reservoir may be fluidically connected to the ejection chamber 1232 through the fluid passage opening 1212.

[0109] FIG. 13 is a block diagram of an example fluid ejection device 1300 with a wall 1334 of a fluid inlet channel 1336 extending into a fluid passage opening 1312. The fluid passage opening 1312 is fluidically connected to a chamber layer 1330. The chamber layer 1330 includes an ejection chamber 1332. The fluid ejection device 1300 includes a nozzle orifice 1342 fluidically connected to the ejection chamber 1332. The fluid inlet channel 1336 is fluidically connected to the ejection chamber 1332. The fluid inlet channel 1336 may fluidically connect the ejection chamber 1332 and the fluid passage opening 1312. The wall 1334 of the fluid inlet channel 1336 extends into the fluid passage opening 1312 to form a cantilever structure. A first portion of the wall 1334 may extend from a bottom to a top of the chamber layer 1330 and a second portion of the wall 1334 may extend into the fluid passage opening 1312. The second portion of the wall 1334 may extend, without contacting a bottomof the chamber layer 1330, into the fluid passage opening 1312 such that the second portion of the wall 1334 cantilevers (extends from a support beyond the support) out into the fluid passage opening 1312. The second portion of the wall 1334 may extend beyond the chamber layer 1330 into an actuator layer and / or a substrate layer of the fluid ejection device 1300.

[0110] In some implementations, the wall 1334 may extend across a width of the fluid passage opening 1312. The wall 1334 may extend beyond the chamber layer 1330 into the actuator layer and / or a substrate layer as well as across the width of the fluid passage opening 1312. A first portion of the wall 1334 may be on a shelf within the chamber layer 1330 and a second portion of the wall 1334 may extend across the width of the fluid passage opening 1312 and beyond the chamber layer 1330 into an actuator layer and / or a substrate layer of the fluid ejection device 1300. In some implementations, the wall 1334 connects (across the fluid passage opening 1312) with a pillar between the fluid passage opening 1312 and a second ejection chamber across the fluid passage opening 1312.[OHl] In some implementations, the fluid passage opening 1312 is fluidically connected to a reservoir containing fluid. The reservoir may be fluidically connected to the ejection chamber 1332 through the fluid passage opening 1312 and the fluid inlet channel 1336.

[0112] FIG. 14 is a block diagram of an example fluid ejection device 1400 with a portion of a pillar 1434 extending into a fluid passage opening 1412. The fluid passage opening 1412 is fluidically connected to a chamber layer 1430. The portion of the pillar 1434 which extends into the fluid passage opening 1412 may be referred to as the extending portion of the pillar 1434. The chamber layer 1430 includes an ejection chamber 1432. The pillar 1434 is between the fluid passage opening 1412 and the ejection chamber 1432 on a shelf 1424 of the chamber layer 1430. The extending portion of the pillar extends into the fluid passage opening 1412 to form a cantilever structure. A shelf portion of the pillar 1434 may extend from a bottom to a top of the chamber layer 1430 on the shelf 1424 and the extending portion of the pillar 1434may extend into the fluid passage opening 1412. The extending portion of the pillar 1434 may extend, without contacting a bottom of the chamber layer 1430, into the fluid passage opening 1412 such that the second portion of the pillar 1434 cantilevers out into the fluid passage opening 1412. The extending portion of the pillar 1434 may extend beyond the chamber layer 1430 into an actuator layer and / or a substrate layer of the fluid ejection device 1400.

[0113] In some implementations, the pillar 1434 may include a leading edge extending into the fluid passage opening 1412 and a trailing edge facing the ejection chamber 1432. The trailing edge may be configured to reduce an angle of expansion of a fluid inlet channel fluidically connecting the ejection chamber 1432 and the fluid passage opening 1412. The leading edge may be positioned such that fluid from the fluid passage opening 1412 contacts the leading edge before contacting the trailing edge. The trailing edge may reduce the angle of expansion of the fluid inlet channel to facilitate priming of the ejection chamber 1432. The trailing edge may reduce an effective width of the fluid inlet channel to facilitate priming of the ejection chamber 1432.

[0114] In some implementations, the pillar 1434 extends across a width of the fluid passage opening 1412. The pillar 1434 may extend beyond the chamber layer 1430 into an actuator layer and / or a substrate layer of the fluid ejection device 1400 as well as across the width of the fluid passage opening 1412. A first portion of the pillar 1434 may be on a shelf of the chamber layer 1430 and a second portion of the protrusion 134 may extend across the width of the fluid passage opening 1412 and beyond the chamber layer 1430 into the actuator layer and / or the substrate layer. In some implementations, the pillar 1434 connects (across the fluid passage opening 1412) a second pillar between the fluid passage opening 1412 and a second ejection chamber across the fluid passage opening 1412.

[0115] In some implementations, the fluid passage opening 1412 is fluidically connected to a reservoir containing fluid. The reservoir is fluidically connected to the ejection chamber 1432 through the fluid passage opening 1412.

[0116] Characteristics attributed to the fluid ejection device 1200 of FIG. 12, the fluid ejection device 1300 of FIG. 13, and / or the fluid ejection device 1400 of FIG. 14 can be attributed to any of the fluid ejection device 1200 of FIG. 12, the fluid ejection device 1300 of FIG. 13, and / or the fluid ejection device 1400 of FIG. 14. In addition, characteristics of the fluid ejection device 1200 of FIG. 12, the fluid ejection device 1300 of Fig. 13, and / or the fluid ejection device 1400 of FIG. 14 can be combined within a single fluid ejection device.

[0117] FIG. 15 illustrates a cross-section of an example fluid ejection device 1500. The fluid ejection device 1500 includes a substrate layer 1510, an actuator layer 1520, a chamber layer 1530, and a nozzle layer 1540. The fluid ejection device 1500 may be partially or completely formed by depositing layers on a substrate. In an example, the fluid ejection device 1500 may be partially or completely formed by depositing layers of material on the substrate layer 1510.

[0118] The substrate layer 1510 includes a fluid passage opening 1512. The fluid passage opening 1512 allows a fluid 1502 to travel through the substrate layer 1510 and the actuator layer 1520 to the chamber layer 1530. The substrate layer 1510 includes circuitry for controlling fluid ejection. In an example, the substrate layer 1510 is silicon. In an example, the substrate layer 1510 includes circuitry for controlling fluid actuation by a fluid actuator 1522. The fluid actuator 1522 may be in the actuator layer 1520. The fluid actuator 1522 may span a height of the actuator layer 1520 or a portion of the height of the actuator layer 1520. The actuator layer 1520 may be adjacent the substrate layer 1510. The actuator layer 1520 includes the fluid passage opening 1512 to allow the fluid 1502 to pass to the chamber layer1530.

[0119] The chamber layer 1530 includes an ejection chamber 1532 fluidically connected to a fluid inlet channel 1536. The chamber layer 1530 is adjacent the actuator layer 1520. The ejection chamber 1532 may include or be adjacent the fluid actuator 1522 such that the fluid actuator 1522 can actuate the fluid 1502 when the fluid 1502 is in the ejection chamber 1532. The nozzle layer 1540 is adjacent the chamber layer 1530. The nozzle layer 1540 includes a nozzle 1542. The ejection chamber 1532 may include or be adjacent the nozzle 1542 such that the fluid actuator 1522 can actuate the fluid 1502 when the fluid 1502 is in the ejection chamber 1532 to eject the fluid through the nozzle 1542.

[0120] The chamber layer 1530 includes side walls of the fluid inlet channel 1536 (not shown in FIG. 15). The side walls of the fluid inlet channel 1536 are on a shelf 1524 of the actuator layer 1520. In some implementations, the side walls of the fluid inlet channel 1536 extend from the shelf 1524 of the actuator layer 1520 to the nozzle layer 1540, or along an entire height of the chamber layer 1530. The bottom of the fluid inlet channel 1536 (when viewed from the nozzle layer) is the shelf 1524 and the top of the fluid inlet channel 1536 is the nozzle layer 1540.

[0121] The fluid 1502 may form a meniscus 1504 at an interface between the fluid passage opening 1512 and the chamber layer 1530. The fluid 1502 may be pinned, or stuck, at the meniscus 1504 such that the ejection chamber 1532 does not prime. The fluid 1502 can be pinned due to interactions between the fluid passage opening 1512 and the chamber layer 1530. In an example, the interface between the fluid passage opening 1512 and the chamber layer 1530 has an angle of expansion of one hundred and eighty degrees, causing the convex meniscus 1504 to form and the fluid 1502 to be pinned at the interface between the fluid passage opening 1512 and the chamber layer 1530. In an example, the fluid 1502 is pinned due to a change in topography or material at the interface between the fluid passage opening 1512 and the chamber layer 1530.

[0122] In some implementations, the fluid 1502 is not pinned and fills the ejection chamber 1532 such that the ejection chamber 1532 is primed. The ejection chamber 1532 may be primed due to capillary forces drawing the fluid 1502 into the ejection chamber 1532. The capillary forces may draw the fluid 1502 into the ejection chamber 1532 due to a protrusion in the chamber layer 1530 which extends into the fluid passage opening 1512. In an example, the protrusion extends into the fluid passage opening 1512 such that the protrusion contacts or pierces the meniscus 1504. In an example, the protrusion extends into the fluid passage opening 1512 such that the meniscus 1504 does not form.

[0123] In some examples, the chamber layer 1530 has a height of between 8 and 50 micrometers. In some examples, the fluid passage opening 1512 has dimensions of 30-200 micrometers by 30-1000 micro-meters.

[0124] FIG. 16 illustrates a cross-section of an example fluid ejection device 1600 including a protrusion 1634 extending from a shelf 1624 of a chamber layer 1630 adjacent a fluid passage opening 1612 into the fluid passage opening 1612. The fluid ejection device 1600 may be similar in many regards to the fluid ejection device 1500 of FIG. 15, with the exception that the fluid ejection device 1600 includes the protrusion 1634 while the fluid ejection device 1500 of FIG. 15 does not include a protrusion. The fluid ejection device 1600 may be an example of the fluid ejection device 1200 of FIG. 12, the fluid ejection device 1300 of FIG. 13, and / or the fluid ejection device 1400 of FIG. 14. The protrusion 1634 may extend within the chamber layer 1630 into the fluid passage opening 1612. In some implementations, the protrusion 1634 extends within the chamber layer 1630 into the fluid passage opening 1612 and does not extend into the actuator layer 1620 or the substrate layer 1610. In some implementations, the protrusion 1634 extends within the chamber layer 1630 into the fluid passage opening 1612 and beyond the chamber layer 1630 into an actuator layer 1620 and a substrate layer 1610 (as shown). The protrusion 1634 may prevent a fluid 1602from being pinned at an interface between the fluid passage opening 1612 and the chamber layer 1630 such that the fluid 1602 passes through a fluid inlet channel 1636 into an ejection chamber 1632 to prime the ejection chamber 1632. Once the ejection chamber 1632 is primed, a fluid actuator 1622 in the actuator layer 1620 between the substrate layer ejects the fluid 1602 from the ejection chamber 1632 through a nozzle 1642 in a nozzle layer 1640.

[0125] The protrusion 1634 may have any shape. A leading edge of the protrusion 1634 (extending into the fluid passage opening 1612) may be rounded, flat, sharp, or any other geometry. A trailing edge of the protrusion 1634 (towards the ejection chamber 1632) may be rounded, flat, sharp, or any other geometry. In an example, the trailing edge of the protrusion 1634 is sharp. In some implementations, the protrusion 1634 extends from a top to a bottom (along an entire height) of the chamber layer 1630. In some implementations, the protrusion 1634 extends a portion of the height of the chamber layer 1630 from the shelf 1624. In some implementations, the protrusion 1634 extends beyond the chamber layer 1630 along a portion of a height of the actuator layer 1620.

[0126] FIG. 17 illustrates a cross-section of an example fluid ejection device 1700 including a protrusion 1734 extending from a shelf 1724 of the chamber layer 1730 across a fluid passage opening 1712. The fluid ejection device 1700 may be similar in many regards to the fluid ejection device 1500 of FIG. 15, with the addition of the protrusion 1734. The fluid ejection device 1700 may be an example of the fluid ejection device 1200 of FIG. 12, the fluid ejection device 1300 of Fig. 13, and / or the fluid ejection device 1400 of FIG. 14. The protrusion 1734 fluid ejection device 1700 may be similar in many regards to the fluid ejection device 1600 of FIG. 16, except the protrusion 1734 extends across the fluid passage opening 1712. The protrusion 1734 extends within the chamber layer 1730 into the fluid passage opening 1712 across the fluid passage opening 1712. In some implementations, the protrusion 1734 extends within the chamber layer 1730 across the fluid passage opening 1712and does not extend into the actuator layer 1720 or the substrate layer 1710. In some implementations, the protrusion 1734 extends within the chamber layer 1730 into the fluid passage opening 1712 and beyond the chamber layer 1730 into the actuator layer 1720 and the substrate layer 1710 (as shown). The protrusion 1734 may prevent a fluid 1702 from being pinned at an interface between the fluid passage opening 1712 and the chamber layer 1730 such that the fluid 1702 passes through a fluid inlet channel 1736 into an ejection chamber 1732 to prime the ejection chamber 1732. Once the ejection chamber 1732 is primed, a fluid actuator 1722 in the actuator layer 1720 between the substrate layer ejects the fluid 1702 from the ejection chamber 1732 through a nozzle 1742 in a nozzle layer 1740.

[0127] The protrusion 1734 may have any shape. A trailing edge of the protrusion 1734 (towards the ejection chamber 1732) may be rounded, flat, sharp, or any other geometry. In an example, the trailing edge of the protrusion 1734 is sharp. In some implementations, the protrusion 1734 extends from a top to a bottom (along an entire height) of the chamber layer 1730. In some implementations, the protrusion 1734 extends a portion of the height of the chamber layer 1730 from the shelf 1724. In some implementations, the protrusion 1734 extends beyond the chamber layer 1730 along a portion of a height of the actuator layer 1720.

[0128] FIG. 18 illustrates an example ejection chamber 1832 fluidically connected to an example fluid inlet channel 1836 with walls 1834 of the fluid inlet channel 1836 extending into a fluid passage opening 1812. The walls 1834 of the fluid inlet channel 1836 may extend from a shelf 1824 adjacent the fluid passage opening 1812 into the fluid passage opening 1812 to form cantilever structures, or protrusions. The fluid inlet channel 1836 may fluidically connect the ejection chamber 1832 and the fluid passage opening 1812 to prime the ejection chamber 1832. Once the ejection chamber 1832 is primed, a fluid actuator 1822 of the ejection chamber 1832 ejects fluid out of the ejection chamber 1832 through a nozzle.

[0129] The walls 1834 of the fluid inlet channel 1836 extend into the fluid passage opening 1812 in order to prevent pinning of a fluid at the fluid passage opening 1812. The walls 1834 extend into the fluid passage opening 1812 to prevent pinning of a meniscus at the fluid passage opening 1812. The walls 1834 extend into the fluid passage opening 1812 along a plane of the shelf 1824. In some examples, the walls 1834 extend into the fluid passage opening 1812 along the plane of the shelf 1824. In some examples, the walls 1834 extend into the fluid passage opening 1812 along the plane of the shelf 1824 and beyond the plane of the shelf 1824 into the fluid passage opening 1812 (as illustrated in FIG. 5). The walls 1834 facilitate drawing liquid out of the fluid passage opening 1812 through the fluid inlet channel 1836 into the ejection chamber 1832.

[0130] In some implementations, the walls 1834 extend one to twenty pmover the shelf 1824 into the fluid passage opening 1812. In an example, the walls 1834 extend about ten pm over the shelf 1824. In an example, the walls 1834 extend about four pm over the shelf 1824. In an example, the walls 1834 extend about two pm over the shelf 1824.

[0131] FIG. 19 illustrates an array of multiple example ejection chambers 1932 fluidically connected to example fluid inlet channels 1936 with walls 1934 of the fluid inlet channels 1936 extending into a fluid passage opening 1912. The ejection chambers 1932 may be similar to or the same as the ejection chamber 1832 of FIG. 18. The fluid inlet channels 1936 may share a wall or walls of the walls 1934. In an example, adjacent fluid inlet channels of the fluid inlet channels 1936 share a wall of the walls 1934. The walls 1934 extend from a shelf 1924 into the fluid passage opening 1912 to form cantilever structures, or protrusions. The walls 1934 extend into the fluid passage opening 1912 in order to prevent pinning of a fluid at the fluid passage opening 1912. The walls 1934 extend into the fluid passage opening 1912 to prevent pinning of a meniscus at the fluid passage opening 1912. The walls 1934 may extend into the fluid passage opening 1912 along a plane of the shelf 1924. In some examples,the walls 1934 extend into the fluid passage opening 1912 along the plane of the shelf 1924. In some examples, the walls 1934 extend into the fluid passage opening 1912 along the plane of the shelf 1924 and beyond the plane of the shelf 1924 into the fluid passage opening 1912 (as illustrated in FIG. 5). The walls 1934 facilitate drawing fluid out of the fluid passage opening 1912 through the fluid inlet channels 1936 into the ejection chambers 1932. The ejection chambers 1932 include fluid actuators 1922 for ejecting the fluid.

[0132] In some implementations, the walls 1934 extend one to twenty pm over the shelf 1924 into the fluid passage opening 1912. In an example, the walls 1934 extend about ten pm over the shelf 1924. In an example, the walls 1934 extend about four pm over the shelf 1924. In an example, the walls 1934 extend about two pm over the shelf 1924.

[0133] FIG. 20 illustrates an example ejection chamber 2032 fluidically connected to an example fluid inlet channel 2036 with a pillar 2034 between the ejection chamber 2032 and a fluid passage opening 2012 extending into the fluid passage opening 2012. The pillar 2034 can be disposed partially or completely within the fluid inlet channel 2036. The pillar 2034 extends from a shelf 2024 adjacent the fluid passage opening 2012 into the fluid passage opening 2012 to form a cantilever structure, or protrusion. The pillar 2034 may be an example of the protrusion 1634 in FIG. 16. The pillar 2034 may be an example of the pillar 1434 of FIG. 14 and / or the protrusion 1234 of FIG. 12. The fluid inlet channel 2036 fluidically connects the ejection chamber 2032 and the fluid passage opening 2012 to prime the ejection chamber 2032. Once the ejection chamber 2032 is primed, a fluid actuator 2022 of the ejection chamber 2032 ejects fluid out of the ejection chamber 2032 through a nozzle.

[0134] The pillar 2034 of the fluid inlet channel 2036 extends into the fluid passage opening 2012 in order to prevent pinning of a fluid at the fluid passage opening 2012. The pillar 2034 extends into the fluid passage opening 2012 to prevent pinning of a meniscus at the fluid passage opening 2012. The pillar 2034 extends into the fluid passage opening 2012 along aplane of the shelf 2024. In some examples, the pillar 2034 extends into the fluid passage opening 2012 along the plane of the shelf 2024. In some examples, the pillar 2034 extends into the fluid passage opening 2012 along the plane of the shelf 2024 and beyond the plane of the shelf 2024 into the fluid passage opening 2012 (as illustrated in FIG. 5). The pillar 2034 facilitates drawing liquid out of the fluid passage opening 2012 through the fluid inlet channel 2036 into the ejection chamber 2032. In some examples, the pillar 2034 extends from within the ejection chamber 2032 into the fluid passage opening 2012 to facilitate drawing liquid out of the fluid passage opening 2012 through the fluid inlet channel 2036 into the ejection chamber 2032.

[0135] In some implementations, the pillar 2034 is located within the fluid inlet channel 2036. The pillar 2034 can be referred to as an “interior pillar” when it is located within the fluid inlet channel 2036. The pillar 2034 may be located at a distance from side walls of the fluid inlet channel 2036 to facilitate priming of the ejection chamber 2032. In some examples, the pillar 2034 can have a widening portion at an upstream end (leading edge) of the pillar 2034. As used herein, “widening portion” refers to a portion of the pillar 2034 that increases in width with respect to the direction of fluid flow. The widening portion increases in width towards the side walls of the fluid inlet channel 2036. The widening portion of the pillar 2034 can form various acute angles with the side walls of the fluid inlet channel 2036 and the top and bottom of the fluid inlet channel 2036. These acute angles can attract fluid because of adhesion forces between the fluid and the walls and / or the top and bottom of the fluid inlet channel 2036.

[0136] In some examples, the pillar 2034 can have a tapering portion at a downstream end (trailing edge) of the pillar 2034. As used herein, “tapering portion” means that the width of the pillar 2034 decreases with respect to the fluid flow direction. The tapering portion decreases in width away from the side walls of the fluid inlet channel 2036.

[0137] The pillar 2034 can have a variety of shapes which facilitate fluid flow through the fluid inlet channel 2036 by capillary action. The pillar 2034 can have a variety of shapes which do not cause fluid pinning due. In some examples, the widening portion can have a wedge shape, with an angled upstream edge (leading edge). The wedge-shaped upstream edge (leading edge) of the pillar 2034 can have an angle of pillar widening in the same plane as the angle of expansion of the fluid inlet channel 2036. In some implementations, the angle of pillar widening is one degree to one hundred and sixty degrees. In an example, the angle of pillar widening is one degree to one hundred and sixty degrees. In some examples, the angle of pillar widening is ten degrees to one hundred degrees. In some examples, the angle of pillar widening is fifteen degrees to ninety degrees. In some examples, the angle of pillar widening is twenty degrees to sixty degrees. The widening portion can also have other shapes, such as a polygonal shape or a rounded shape. The tapering portion can end at an angled downstream edge (trailing edge) having an angle of pillar narrowing in the same plane as the angle of expansion of the fluid inlet channel 2036. In some implementations, the angle of pillar narrowing is five degrees to forty-five degrees. In an example, the angle of pillar narrowing is five degrees to thirty degrees. In an example, the angle of pillar narrowing is ten degrees to thirty degrees. In an example, the angle of pillar narrowing is twenty degrees to thirty degrees. In an example, the angle of pillar narrowing is twenty degrees to forty-five degrees. In some examples, the tapering portion can have a rounded shape.

[0138] In some implementations, the pillar 2034 extends one to twenty pm over the shelf 2024 into the fluid passage opening 2012. In an example, the pillar 2034 extends about ten pm over the shelf 2024. In an example, the pillar 2034 extends about four pm over the shelf 2024. In an example, the pillar 2034 extends about two pm over the shelf 2024.

[0139] FIG. 21 illustrates a first array of example ejection chambers 2132a fluidically connected to a first array of example fluid inlet channels 2136a and a second array of exampleejection chambers 2132b fluidically connected to a second array of example fluid inlet channels 2136b with protrusions 2134 extending across a fluid passage opening 2112 to connect first walls 2133a of the first array of fluid inlet channels 2136a with second pillars 2135b between the fluid passage opening 2112 and the second array of ejection chambers 2132b and second walls 2133b of the second array of fluid inlet channels 2136b with first pillars 2135a between the fluid passage opening 2112 and the first array of ejection chambers 2132a.

[0140] In some implementations, the protrusions 2134 extend across a width of the fluid passage opening 2112. The protrusions 2134 extend across the fluid passage opening 2112 in order to prevent pinning of a fluid at the fluid passage opening 2112. The protrusions 2134 extend into the fluid passage opening 2112 to prevent formation of a meniscus at the fluid passage opening 2112. The protrusions 2134 extend into the fluid passage opening 2112 along a plane of the first array of ejection chambers 2132a and the second array of ejection chambers 2132b. In some examples, the protrusions 2134 extend into the fluid passage opening 2112 along the plane of the first array of ejection chambers 2132a and the second array of ejection chambers 2132b. In some examples, the protrusions 2134 extend into the fluid passage opening 2112 along the plane of the first array of ejection chambers 2132a and the second array of ejection chambers 2132b and beyond the plane of the first array of ejection chambers 2132a and the second array of ejection chambers 2132b into the fluid passage opening 2112 (as illustrated in FIG. 6). The protrusions 2134 facilitate drawing liquid out of the fluid passage opening 2112 through the first array of fluid inlet channels 2136a and the second array of fluid inlet channels 2136b into the first array of ejection chambers 2132a and the second array of ejection chambers 2132b.

[0141] FIG. 22 illustrates a first array of example ejection chambers 2232a fluidically connected to a first array of example fluid inlet channels 2236a and a second array of exampleejection chambers 2232b fluidically connected to a second array of example fluid inlet channels 2236b with protrusions 2234 extending across a fluid passage opening 2212 to connect first walls 2233a of the first array of fluid inlet channels 2236a with second walls 2233b of the second array of fluid inlet channels 2236b.

[0142] The protrusions 2234 extend across a width of the fluid passage opening 2212. The protrusions 2234 extend across the fluid passage opening 2212 in order to prevent pinning of a fluid at the fluid passage opening 2212. The protrusions 2234 extend into the fluid passage opening 2212 to prevent formation of a meniscus at the fluid passage opening 2212. The protrusions 2234 extend into the fluid passage opening 2212 along a plane of the first array of ejection chambers 2232a and the second array of ejection chambers 2232b. In some examples, the protrusions 2234 extend into the fluid passage opening 2212 along the plane of the first array of ejection chambers 2232a and the second array of ejection chambers 2232b. In some examples, the protrusions 2234 extend into the fluid passage opening 2212 along the plane of the first array of ejection chambers 2232a and the second array of ejection chambers 2232b and beyond the plane of the first array of ejection chambers 2232a and the second array of ejection chambers 2232b into the fluid passage opening 2212 (as illustrated in FIG. 6). The protrusions 2234 facilitate drawing liquid out of the fluid passage opening 2212 through the first array of fluid inlet channels 2236a and the second array of fluid inlet channels 2236b into the first array of ejection chambers 2232a and the second array of ejection chambers 2232b.

[0143] FIG. 23 illustrates a first array of example ejection chambers 2332a fluidically connected to a first array of example fluid inlet channels 2336a and a second array of example ejection chambers 2332b fluidically connected to a second array of example fluid inlet channels 2336b with protrusions 2334 extending across a fluid passage opening 2312 to connect first pillars 2335a between the fluid passage opening 2312 and the first array ofejection chambers 2332a with second pillars 2335b between the fluid passage opening 2312 and the second array of ejection chambers 2332b. In some implementations, the protrusions 2334, the first pillars 2335a, and the second pillars 2335b have a same material. In some implementations, the protrusions 2334, the first pillars 2335a, and the second pillars 2335b are monolithic.

[0144] The protrusions 2334 extend across a width of the fluid passage opening 2312. The protrusions 2334 extend across the fluid passage opening 2312 in order to prevent pinning of a fluid at the fluid passage opening 2312. The protrusions 2334 extend into the fluid passage opening 2312 to prevent pinning of a meniscus at the fluid passage opening 2312. The protrusions 2334 extend into the fluid passage opening 2312 along a plane of the first array of ejection chambers 2332a and the second array of ejection chambers 2332b. In some examples, the protrusions 2334 extend into the fluid passage opening 2312 along the plane of the first array of ejection chambers 2332a and the second array of ejection chambers 2332b. In some examples, the protrusions 2334 extend into the fluid passage opening 2312 along the plane of the first array of ejection chambers 2332a and the second array of ejection chambers 2332b and beyond the plane of the first array of ejection chambers 2332a and the second array of ejection chambers 2332b into the fluid passage opening 2312 (as illustrated in FIG. 6). The protrusions 2334 facilitate drawing liquid out of the fluid passage opening 2312 through the first array of fluid inlet channels 2336a and the second array of fluid inlet channels 2336b into the first array of ejection chambers 2332a and the second array of ejection chambers 2332b.

[0145] FIG. 24 illustrates a first array of example ejection chambers 2432a fluidically connected to a first array of example fluid inlet channels 2436a on a first side of a fluid passage opening 2412 and a second array of example ejection chambers 2432b fluidically connected to a second array of example fluid inlet channels 2436b on a second side of thefluid passage opening 2412 with a protrusion extending into the fluid passage opening 2412 on a third side of the fluid passage opening 2412.

[0146] The protrusion 2434 extends into the fluid passage opening 2412 in order to prevent pinning of a fluid at the fluid passage opening 2412. The protrusion 2434 extends into the fluid passage opening 2412 to prevent formation of a meniscus at the fluid passage opening 2412. The protrusion 2434 extends into the fluid passage opening 2412 along a plane of the shelf 2424. In some implementations, the protrusion 2434 extends from a shelf 2424 adjacent the fluid passage opening 2412 into the fluid passage opening 2412. In some examples, the protrusion 2434 extends into the fluid passage opening 2412 along the plane of the shelf 2424. In some examples, the protrusion 2434 extends into the fluid passage opening 2412 along the plane of the shelf 2424 and beyond the plane of the shelf 2424 into the fluid passage opening 2412 (as illustrated in FIG. 5). The protrusion 2434 facilitates drawing liquid out of the fluid passage opening 2412 through the first array of fluid inlet channels 2436a into the first array of ejection chambers 2432a and through the second array of fluid inlet channels 2436b into the second array of ejection chambers 2432b. In some examples, the protrusion 2434 being located on the third side of the fluid passage opening 2412 facilitates passage of fluid between adjacent ejection chambers in the first array of ejection chambers 2432a and between adjacent ejection chambers in the second array of ejection chambers 2432b, as there are no protrusions between the adjacent ejection chambers.

[0147] In some implementations, the protrusion 2434 extends one to twenty pm over the shelf 2424 into the fluid passage opening 2412. In an example, the protrusion 2434 extends about ten pm over the shelf 2424. In an example, the protrusion 2434 extends about four pm over the shelf 2424. In an example, the protrusion 2434 extends about two pm over the shelf 2424.

[0148] FIG. 25 illustrates a first array of example ejection chambers 2532a on a first side of a fluid passage opening 2512 and a second array of example ejection chambers 2532b on asecond side of the fluid passage opening 2512 with a first protrusion 2534a extending into the fluid passage opening 2512 on a third side of the fluid passage opening and a second protrusion 2534b extending into the fluid passage opening 2512 on a fourth side of the fluid passage opening 2512.

[0149] The first protrusion 2534a and the second protrusion 2534b may be the same as or similar to the protrusion 2434 of FIG. 24. The first protrusion 2534a and the second protrusion 2534b facilitate drawing liquid out of the fluid passage opening 2512 into the first array of ejection chambers 2532a and into the second array of ejection chambers 2532b. In some examples, the first protrusion 2534a and the second protrusion 2534b being located on the third side and the fourth side, respectively, of the fluid passage opening 2512 facilitates passage of fluid between adjacent ejection chambers in the first array of ejection chambers 2532a and between adjacent ejection chambers in the second array of ejection chambers 2532b, as there are no protrusions between the adjacent ejection chambers, improving a speed of priming the first array of example ejection chambers 2532a and the second array of example ejection chambers 2532b.

[0150] In some implementations, the first protrusion 2534a and the second protrusion 2534b extend a same distance into the fluid passage opening 2512. In some implementations, the first protrusion 2534a and the second protrusion 2534b extend different distances into the fluid passage opening 2512. In an example, the first protrusion 2534a and / or the second protrusion 2534b extend one to twenty pm into the fluid passage opening 1312. In an example, the first protrusion 2534a and / or the second protrusion 2534b extend about ten pm into the fluid passage opening 2512. In an example, the first protrusion 2534a and / or the second protrusion 2534b extend about four pm into the fluid passage opening 2512. In an example, the first protrusion 2534a and / or the second protrusion 2534b extend about two pm into the fluid passage opening 2512.

[0151] As discussed herein, the protrusions described in FIGS. 16-25 can be included in a dispenser device, such as the dispenser devices described in FIGS. 1-3.

[0152] In some implementations, a combination of the geometry of the fluid inlet passage (i.e., angle of expansion), the presence of a protrusion extending into a fluid passage opening, and vibrational energy provided by a mechanical actuator is needed to cause priming of an ejection chamber. As each of these three features (angle of expansion, protrusion, vibrational energy) facilitates passage of fluids through the fluid inlet passage into the ejection chamber (i.e., priming), their effect may be cumulative, such that the combination of all three of these features facilitates priming more than any of these three features alone. Characteristics of a fluid determine whether the fluid will successfully pass through a particular fluid inlet passage to prime the ejection chamber. Fluids with lower surface tensions, such as surfactant-laden fluids, may pass through a fluid inlet passage having an angle of expansion of greater than eighty degrees, without a protrusion extending into the fluid passage opening, and without vibrational energy. Other fluids with higher surface tensions, such as certain aqueous fluids, may pass through a fluid inlet passage having an angle of expansion of less than eighty degrees, without a protrusion extending into the fluid passage opening, and without vibrational energy. Some fluids, such as certain aqueous fluids, may pass through a fluid inlet passage having an angle of expansion of less than eighty degrees, with a protrusion extending into the fluid passage opening, and without vibrational energy. Additional fluids, such as certain aqueous fluids, may pass through a fluid inlet passage having an angle of expansion of less than eighty degrees, with a protrusion extending into the fluid passage opening, and with vibrational energy.

[0153] In some implementations, the combination of a fluid inlet passage having an angle of expansion of less than eighty degrees and vibrational energy is sufficient to cause a wide variety of fluids to pass through the fluid inlet channel to prime an ejection chamber. Thecombination of the angle of expansion of less than eighty degrees and vibrational energy facilitates priming more effectively than either one separately. In an example, a liquid that does not prime through a fluid inlet channel having an angle of expansion greater than eighty degrees in the presence of vibrational energy and that does not prime through a fluid inlet channel having an angle of expansion less than eighty degrees without vibrational energy can successfully prime through a fluid inlet channel having an angle of expansion less than eighty degrees in the presence of vibrational energy.

[0154] In some implementations, the mechanical actuator includes a solenoid. In some implementations, the solenoid imparts vibrational energy to a support structure mechanically coupled to the fluid ejection device. In some implementations, the solenoid imparts the amount of vibrational energy directly to the fluid ejection device. In some implementations, the dispenser device includes a spring to accelerate a structure to strike the fluid ejection device. In some implementations, the dispenser device includes a solenoid to provide tension to the spring. In some implementations, the fluid ejection device includes a fluid passage opening fluidically connected to the fluid inlet channel, and a protrusion extending from the fluid inlet channel into the fluid passage opening. In some implementations, the amount of vibrational energy within the predetermined range facilitates movement of an aqueous fluid through the fluid inlet channel into the ejection chamber.

[0155] Aspects of the disclosure are directed to a dispenser device including an ejection chamber including a fluid actuator, a fluid inlet channel fluidically connected to the ejection chamber, the fluid inlet channel having an angle of expansion less than or equal to eighty degrees, a fluid passage opening fluidically connected to the fluid inlet channel, a protrusion extending from the fluid inlet channel into the fluid passage opening, and a mechanical actuator to impart an amount of vibrational energy within a predetermined range to the fluid inlet channel.

[0156] In some implementations, the mechanical actuator includes a solenoid. In some implementations, the solenoid imparts vibrational energy to a support structure mechanically coupled to the fluid inlet channel. In some implementations, the mechanical actuator includes a spring to accelerate a structure to generate vibrational energy. In some implementations, the dispenser device includes a solenoid to provide tension to the spring. In some implementations, the structure accelerates to strike a support structure mechanically coupled to the fluid inlet channel to impart the amount of vibrational energy to the fluid inlet channel. In some implementations, the amount of vibrational energy within the predetermined range facilitates movement of an aqueous fluid from the fluid passage opening into the ejection chamber.

Claims

WHAT IS CLAIMED IS:

1. A dispenser device comprising: a fluid ejection device comprising: an ejection chamber including: a fluid actuator; a nozzle; a fluid inlet channel fluidically connected to the ejection chamber, the fluid inlet channel having an angle of expansion less than or equal to eighty degrees; and a mechanical actuator to impart an amount of vibrational energy within a predetermined range to the fluid ejection device.

2. The dispenser device of claim 1, wherein the mechanical actuator comprises a solenoid.

3. The dispenser device of claim 2, wherein the solenoid imparts vibrational energy to a support structure mechanically coupled to the fluid ejection device.

4. The dispenser device of claim 2, wherein the solenoid imparts the amount of vibrational energy directly to the fluid ejection device.

5. The dispenser device of claim 1, wherein the dispenser device includes a spring to accelerate a structure to strike the fluid ejection device.

6. The dispenser device of claim 5, wherein the dispenser device includes a solenoid to provide tension to the spring.

7. The dispenser device of claim 1, wherein the fluid ejection device includes: a fluid passage opening fluidically connected to the fluid inlet channel; and a protrusion extending from the fluid inlet channel into the fluid passage opening.

8. The dispenser device of claim 1, wherein the amount of vibrational energy within the predetermined range facilitates movement of an aqueous fluid through the fluid inlet channel into the ejection chamber.

9. A dispenser device comprising: a microfluidic structure comprising: an ejection chamber including a fluid actuator; a fluid inlet channel fluidically connected to the ejection chamber, the fluid inlet channel having an angle of expansion less than or equal to eighty degrees; a fluid passage opening fluidically connected to the fluid inlet channel; a protrusion extending from the fluid inlet channel into the fluid passage opening; and a mechanical actuator to impart an amount of vibrational energy within a predetermined range to the fluid inlet channel.

10. The dispenser device of claim 9, wherein the mechanical actuator comprises a solenoid.

11. The dispenser device of claim 10, wherein the solenoid imparts vibrational energy to a support structure mechanically coupled to the fluid inlet channel.

12. The dispenser device of claim 9, wherein the mechanical actuator includes a spring to accelerate a structure to provide vibrational energy.

13. The dispenser device of claim 12, wherein the dispenser device includes a solenoid to provide tension to the spring.

14. The dispenser device of claim 12, wherein the structure accelerates to strike a support structure mechanically coupled to the fluid inlet channel to impart the amount of vibrational energy to the fluid inlet channel.

5. The dispenser device of claim 9, wherein the amount of vibrational energy within the predetermined range facilitates movement of an aqueous fluid from the fluid passage opening into the ejection chamber.

Images