Abstract:
A fluid ejection device is disclosed that includes a body defining an interior bore, a fluid reservoir, and a fluid ejection chip. The fluid reservoir includes a wall and one or more fluid control surfaces disposed along an interior surface of the wall. The fluid reservoir defines an interior passage in fluid communication with the interior bore of the body. The fluid ejection chip is disposed on the body and comprises one or more fluid ejection actuators. The fluid ejection chip has one or more interior fluid paths in fluid communication with the interior bore of the body so that the fluid ejection chip ejects the fluid upon activation of the one or more fluid ejection actuators. The interior passage of the fluid reservoir, the interior bore of the body, and the one or more interior fluid paths are axially aligned such that the fluid is gravity fed to the fluid ejection chip upon entry into the interior passage of the fluid reservoir. The one or more fluid control surfaces are disposed along the interior passage of the fluid reservoir so that the fluid adheres to the one or more fluid control surfaces.

Description:
FIELD 
       [0001]    This invention is related to fluid ejection devices, and in particular, to fluid ejection devices that minimize fluid waste. 
       BACKGROUND 
       [0002]    In some applications, discrete quantities of fluid are deposited onto a surface, for example, pharmaceutical applications, chemical applications, industrial applications, and medical testing applications, to name a few. Accordingly, fluids may be transported from a fluid reservoir and applied to a target surface with a fluid applicator, such as, for example, a pipette or fluid dropper. 
       SUMMARY OF THE INVENTION 
       [0003]    An object of the present invention is to provide a fluid ejection device for depositing predetermined quantities of fluid onto a target surface. 
         [0004]    Another object of the present invention is to provide a fluid ejection device for ejecting a predetermined quantity of fluid while minimizing any remainder fluid to be stored in the fluid ejection device so that fluid waste is minimized. 
         [0005]    In an exemplary embodiment, a fluid ejection device is disclosed that comprises a body defining an interior bore, a fluid reservoir, and a fluid ejection chip. The fluid reservoir comprises a wall and one or more fluid control surfaces disposed along an interior surface of the wall. The fluid reservoir defines an interior passage in fluid communication with the interior bore of the body. The fluid ejection chip is disposed on the body and comprises one or more fluid ejection actuators. The fluid ejection chip has one or more interior fluid paths in fluid communication with the interior bore of the body so that the fluid ejection chip ejects the fluid upon activation of the one or more fluid ejection actuators. The interior passage of the fluid reservoir, the interior bore of the body, and the one or more interior fluid paths are axially aligned such that the fluid is gravity fed to the fluid ejection chip upon entry into the interior passage of the fluid reservoir. The one or more fluid control surfaces are disposed along the interior passage of the fluid reservoir so that the fluid adheres to the one or more fluid control surfaces. 
         [0006]    In embodiments, the one or more fluid control surfaces protrude from the annular wall of the fluid reservoir. 
         [0007]    In embodiments, the one or more fluid control surfaces are recessed into the annular wall of the fluid reservoir. 
         [0008]    In embodiments, the one or more fluid control surfaces have a cross-sectional profile selected from the group comprising: rounded rectangular, curvate, pointed, and hook-shaped. 
         [0009]    In embodiments, a surface of the annular wall of the fluid reservoir is coated with a hydrophilic substance. 
         [0010]    In embodiments, at least a portion of the fluid reservoir protrudes from the body. 
         [0011]    In embodiments, the one or more fluid ejection actuators are thermal ejection actuators. 
         [0012]    In embodiments, the fluid ejection chip comprises a substrate, a flow feature layer disposed over the substrate, and a nozzle layer disposed over the flow feature layer. 
         [0013]    In embodiments, the fluid ejection chip comprises a nozzle layer defining one or more nozzles. 
         [0014]    In embodiments, the fluid reservoir widens in the direction of the body. 
         [0015]    In embodiments, the one or more interior fluid paths are substantially linear. 
         [0016]    In embodiments, the body comprises a surface feature for engagement by a user. 
         [0017]    In an exemplary embodiment, a fluid ejection system comprises a fluid ejection printer and a fluid ejection device. The fluid ejection printer comprises a housing and at least one of an internal power source or one or more electrical contacts in electrical communication with an external power source. The fluid ejection device comprises a body defining an interior bore, a fluid reservoir, a fluid ejection chip, and an electrical connector. The fluid reservoir comprises a wall and one or more fluid control surfaces disposed along an interior surface of the wall. The fluid reservoir defines an interior passage in fluid communication with the interior bore of the body. The fluid ejection chip is coupled with the body and comprises one or more fluid ejection actuators. The fluid ejection chip has one or more interior fluid paths in fluid communication with the interior bore of the body so that the fluid ejection chip ejects the fluid upon activation of the one or more fluid ejection actuators. The electrical connector is in electrical communication with the fluid ejection printer so that power is supplied from the fluid ejection printer to the fluid ejection chip. The interior passage of the fluid reservoir, the interior bore of the body, and the one or more interior fluid paths are axially aligned such that the fluid is gravity fed to the fluid ejection chip upon entry into the interior passage of the fluid reservoir. The one or more fluid control surfaces are disposed along the interior passage of the fluid reservoir so that the fluid adheres to the one or more fluid control surfaces. 
         [0018]    In embodiments, the fluid ejection printer comprises a carrier for coupling with the fluid ejection device. 
         [0019]    In embodiments, the carrier is moveable with respect to the housing of the fluid ejection printer. 
         [0020]    In embodiments, the fluid ejection printer comprises a controller. 
         [0021]    In an exemplary embodiment, a method of forming a fluid ejection device comprises: providing an elongate body defining an interior bore and comprising an engagement portion and an ejection portion, the ejection portion comprising a fluid reservoir extending at least partially through the body and defining an interior fluid channel in fluid communication with the interior bore of the body, the fluid reservoir comprising an annular wall and one or more fluid control surfaces disposed along an interior surface of the annular wall; and attaching a fluid ejection chip to the body so that an interior fluid path of the fluid ejection chip is axially aligned with and in fluid communication with the interior bore of the body and the interior fluid channel of the fluid reservoir. 
         [0022]    In embodiments, the fluid ejection chip comprises one or more fluid ejection actuators. 
         [0023]    In embodiments, the one or more fluid ejection actuators are thermal ejection actuators. 
         [0024]    In embodiments, the one or more fluid control surfaces have a cross-sectional profile selected from the group comprising: rounded rectangular, curvate, pointed, and hook-shaped. 
         [0025]    Other features and advantages of embodiments of the invention will become readily apparent from the following detailed description, the accompanying drawings and the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    The features and advantages of exemplary embodiments of the present invention will be more fully understood with reference to the following, detailed description when taken in conjunction with the accompanying figures, wherein: 
           [0027]      FIG. 1  is a top view of a fluid ejection device according to an exemplary embodiment of the present invention; 
           [0028]      FIG. 2  is a bottom view of the fluid ejection device of  FIG. 1 ; 
           [0029]      FIG. 3  is a side view of the fluid ejection device of  FIG. 1 ; 
           [0030]      FIG. 4A  is an enlarged cross-sectional view taken along the line A-A in  FIG. 3 ; 
           [0031]      FIG. 4B  is an enlarged cross-sectional view taken along the line A-A in  FIG. 3  according to an exemplary embodiment of the present invention; 
           [0032]      FIG. 4C  is an enlarged cross-sectional view taken along the line A-A in  FIG. 3  according to an exemplary embodiment of the present invention; 
           [0033]      FIG. 4D  is an enlarged cross-sectional view taken along the line A-A in  FIG. 3  according to an exemplary embodiment of the present invention; 
           [0034]      FIG. 4E  is an enlarged cross-sectional view taken along the line A-A in  FIG. 3  according to an exemplary embodiment of the present invention; 
           [0035]      FIG. 5  is a top view of a fluid ejection system including the fluid ejection device of  FIG. 1  according to an exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0036]    The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the words “may” and “can” are used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include,” “including,” and “includes” mean including but not limited to. To facilitate understanding, like reference numerals have been used, where possible, to designate like elements common to the figures. 
         [0037]    Referring to  FIG. 1 ,  FIG. 2 , and  FIG. 3 , a fluid ejection device according to an exemplary embodiment of the present invention is illustrated, and is generally designated  100 . Fluid ejection device  100  includes a body  102  along which a fluid reservoir  110 , an electrical connector  120 , and a fluid ejection chip  130  are disposed. 
         [0038]    Body  102  may be an elongate member that includes a user engagement portion  104  and an ejection portion  106 . User engagement portion  104  may include a surface feature  105  (e.g., a knob, bump, or ledge) to provide a user or grasping tool with a recognizable and easily-grasped region for handling fluid ejection device  100 . 
         [0039]    Ejection portion  106  includes fluid reservoir  110 , fluid ejection chip  130 , and at least a portion of electrical connector  120 , as described further herein. Body  102  may be formed of one or more suitable materials for applications described herein, for example, glass, polymeric materials, and composite materials, to name a few. In embodiments, user engagement portion  104  and/or ejection portion  106  may have different configurations. 
         [0040]    As shown, electrical connector  120  extends along a portion of body  102  and is in electrical communication with fluid ejection chip  130  via one or more bond pads  122 . Electrical connector  120  may be a tab automated bonded (TAB) circuit that includes electrical conductors (not shown) that can contact a portion of a fluid ejection system to provide electrical power for fluid ejection chip  130 , as described further herein. In embodiments, electrical connector  120  may have a different configuration, for example, a configuration in which electrical connector  120  is interiorly disposed along at least a portion of body  102 . 
         [0041]    Fluid reservoir  110 , as shown, protrudes from the surface of body  102  and includes an annular wall  112  that circumscribes an interior fluid channel  114  ( FIG. 4 ) extending through fluid reservoir  110 . Fluid reservoir  110  may have a hollow, dome-shaped profile as shown. Fluid reservoir  110  may be a separable component that is coupled to body  102 , for example, by adhesion, welding, or mechanical coupling, to name a few. In embodiments, fluid reservoir  110  may be integrally formed with body  102 . In embodiments, fluid reservoir  110  may have a different configuration, for example, a configuration in which fluid reservoir  110  is flush or recessed with the body  102  of fluid ejection device  100  and/or a configuration in which fluid reservoir  110  is not a curved structure. 
         [0042]    Fluid ejection chip  130  is disposed along the body  102  of fluid ejection device  102  on an opposite side from fluid reservoir  110  such that one or more nozzles  172  of fluid ejection chip  130  are exposed facing a target surface upon which one or more fluids are to be deposited, for example, a testing slide or petri dish. As shown, fluid reservoir  110  and fluid ejection chip  130  are aligned along an axis B extending through fluid ejection device  100  such that a substantially linear and open fluid path is defined between the top of fluid reservoir  110  and nozzles  172  of fluid ejection chip  130 , as described further herein. In this regard, fluids deposited into fluid reservoir  110  can be gravity fed to fluid ejection chip  130 . In embodiments, fluid reservoir  110  may have a configuration such that a backpressure is provided to at least partially counteract the force of gravity on fluids deposited into fluid reservoir  110 , e.g., to control a flow rate of fluid passing through fluid ejection device  100 . 
         [0043]    Turning to  FIG. 4A , an enlarged cross-sectional view of a portion of fluid ejection device  100  is shown, including fluid reservoir  110  and fluid ejection chip  130 . 
         [0044]    Annular wall  112 , as shown, has an exterior surface  112   a  and an interior surface  112   b . Accordingly, an interior diameter of fluid reservoir  110  can be measured between two diametrically opposed points on the interior surface  112   b  of annular wall  112 . The interior diameter of fluid reservoir  110  may widen from a narrowest point at the top of annular wall  112  of, for example, between about 5 mm and 10 mm, to a widest point at the bottom of annular wall  112  of, for example, between about 15 mm and about 25 mm. In embodiments, fluid reservoir  110  may have an interior diameter that widens from 10 mm at the top of annular wall  112  to 18 mm at the bottom of annular wall  112 . A height of fluid reservoir  110  can be measured between a vertically highest point and a vertically lowest point of annular wall  112 . Fluid reservoir  110  may have a height of, for example, between about 3 mm and about 10 mm. In embodiments, fluid reservoir  110  may have a height of 5 mm. In embodiments, fluid reservoir  110  may be dimensioned to accommodate, for example, between about 1.8 cm 3  of fluid and about 4.1 cm 3  of fluid. In embodiments, fluid reservoir  110  may be dimensioned to accommodate about 0.5 grams of a water-based fluid. In this regard, the interior diameter and height of fluid reservoir  110  can be selected to provide a desired interior volume. In embodiments, fluid reservoir  110  may have a different configuration, e.g., an elliptical profile, a rectangular profile, a triangular profile, or a tapered profile such as a conical profile, to name a few. 
         [0045]    As shown, fluid reservoir  110  includes a number of fluid control surfaces  116  disposed circumferentially around the interior surface  112   b  of the annular wall  112 . Fluid control surfaces  116  may protrude at least partially into the interior fluid channel  114  such that fluid control surfaces  116  are disposed along a path that a fluid travels as it passes through fluid ejection device  100 . Fluid control surfaces  116  may have a rounded rectangular profile in cross-section, as shown, or may have a different cross-sectional profile, as described further herein. In embodiments, fluid control surfaces  116  may integrally formed with the wall of fluid reservoir  110 , e.g., may be molded with or cut from the annular wall  112  of fluid reservoir  110 . In embodiments, fluid control surfaces  116  may be affixed to the interior wall of fluid reservoir  110 , e.g., as an o-ring or circumferential clip. 
         [0046]    Fluid control surfaces  116  are configured to contact and engage, e.g., through an adhesion between the fluid and the fluid control surface  116 , fluids passing through the interior fluid channel  114 . As shown, fluids passing by fluid control surfaces  116  may adhere to the fluid control surfaces  116  at points of contact such that surface tension is generated across the fluid. In the exemplary embodiment shown, the outer perimeter of a volume of fluid passing through fluid ejection device  100  may adhere to fluid control surfaces  116  such that, as the bulk of the fluid volume continues to advance downwardly due to the effects of gravity, the outer periphery of the volume of fluid experiences a drag force such that a meniscus M is formed. Although the meniscus M is shown in  FIG. 4A  as being concave, the meniscus may have a convex formation depending on the liquid-control surface interface. 
         [0047]    In this regard, fluid control surfaces  116  impart the fluid with a capillary action to at least partially counteract the weight of fluid passing through fluid reservoir  110  such that the speed, e.g., the flow rate, of fluid passing through interior fluid channel  114  may be slowed. Accordingly, fluid control surfaces  116  may exert backpressure on a fluid passing through fluid reservoir  110  as a degree of control on a fluid that is to be ejected from fluid ejection device  110 . For example, fluid control surfaces  116  may minimize or prevent a fluid passing through interior fluid channel  114  from undesired behavior, such as drooling or dripping, before deliberate ejection by fluid chip  130 , as described further herein. Such a measure of control by fluid control surfaces  116  on fluids passing through fluid reservoir  110  may contribute to minimizing waste with respect to fluids used with fluid ejection device  100  ( FIG. 1 ). 
         [0048]    Turning now to  FIG. 4B , an alternative embodiment of the present invention is illustrated in cross-section, in which a number of fluid control surfaces  116 B are disposed along the interior surface of an annular wall  112 B of a fluid reservoir  110 B. As shown, fluid control surface  116 B have a curvate, e.g., rounded or dome-shaped, cross-sectional profile. 
         [0049]    Referring to  FIG. 4C , another alternative embodiment of the present invention is illustrated, in which a number of fluid control surfaces  116 C are disposed along the interior surface of an annular wall  112 C of a fluid reservoir  110 C. As shown, fluid control surfaces  116 C have a pointed, e.g., wedge-shaped or triangular-shaped, cross-sectional profile. 
         [0050]    Turning to  FIG. 4D , another alternative embodiment of the present invention is illustrated, in which a number of fluid control surfaces  116 D are disposed along the interior surface of an annular wall  112 D of a fluid reservoir  110 D. As shown, engaging surfaces  116 C have an upwardly turned hook-shaped cross-sectional profile. 
         [0051]    Referring to  FIG. 4E , an alternative embodiment of the present invention is illustrated, in which a number of fluid control surfaces  116 E are formed along the annular wall  112 E of a fluid reservoir  110 E. As shown, fluid control surfaces  116 E do not protrude into the interior fluid path  114 E of fluid reservoir  110 E, but instead are recessed within the annular wall  112 E of fluid reservoir  110 E, e.g., by cutting or through inset molding of fluid reservoir  110 E. 
         [0052]    It will be understood that fluid reservoirs described herein in embodiments of the present invention may have different surface configurations, e.g., shape, texture, and/or material composition, such that a desired amount of backpressure is provided to a fluid passing therethrough. In embodiments, fluid control surfaces disposed along a fluid reservoir may have a different configuration, for example, a jagged, barbed, ridged, ribbed, or knurled cross-sectional profile, to name a few. In embodiments, fluid control surfaces disposed along a fluid reservoir may be continuous or may have one or more discontinuities therealong. In embodiments, a fluid reservoir may be treated, e.g., lined or coated, with a material to provide a desired flow rate of fluid passing therethrough, for example, a hydrophilic material. In embodiments, a fluid reservoir may contain additional fluid control surfaces, for example, a lip, ridge, and/or adhesive seam formed along the location at which the fluid reservoir and a fluid ejection device body meet. 
         [0053]    Referring back to  FIG. 4A , body  102  of fluid ejection device  100  includes an interior bore  108  upon which fluid reservoir  110  is disposed so that a fluid path is formed between the interior fluid channel  114  of the fluid reservoir  110  and the interior bore  108  of the body  102 . As shown, interior bore  108  may have a similar diameter to the interior diameter of the widest portion of fluid reservoir  110 , for example, between about 15 mm and about 25 mm. In embodiments, interior bore  108  may have a different diameter. 
         [0054]    Fluid ejection chip  130  may be mounted to body  102  in a suitable fashion, for example, adhesion, molding, or ultrasonic welding. In this regard, fluid ejection device  100  can be assembled by providing body  102  having fluid reservoir  110  and attaching fluid ejection chip  130  to a portion of body  102  such that an interior fluid path of the fluid ejection chip  130  is in fluid communication with the interior bore  108  of the body  102  to provide a substantially open fluid path. 
         [0055]    Fluid ejection chip  130  may include a substrate  140 , a plurality of fluid ejector elements  150 , a flow feature layer  160 , and/or a nozzle layer  170 . In embodiments, ejection chip  130  may have a different configuration. 
         [0056]    Substrate  140  may be formed of semiconductor and/or insulator materials, for example, silicon, silicon dioxide, sapphire, germanium, gallium arsenide, and/or indium phosphide, to name a few. A portion of the substrate  140  may be processed to form one or more fluid channels  144  in fluid communication with the interior bore  108  of body  102 . As described herein, processing portions of a fluid ejection chip may include, for example, mechanical deformation such as grinding, chemical etching, or patterning desired structures with photoresist, to name a few. 
         [0057]    One or more ejector elements  150  may be disposed on the substrate  110 . Ejector elements  150  may be comprised of one or more conductive and/or resistive materials so that when electrical power is supplied to the ejector elements  150 , heat is caused to accumulate on and/or near the ejector elements  150  to eject fluid therefrom, as described further herein. In this regard, ejector elements  150  may be configured as thermal ejection actuators. In embodiments, ejector elements  150  may be formed of more than one layered material, such as a heater stack that may include a resistive element, dielectric, and protective layer. The amount of heat generated by ejector elements  150  may be directly proportional to the amount of power supplied to the ejector elements  150 . In embodiments, power may be supplied to ejector elements  150  such that a predetermined thermal profile is generated by ejector elements  150 , for example, a series of electrical power pulses of constant or variable amplitude and/or duration to achieve intended performance. In embodiments, ejector elements  150  may have a different electrical power configuration, for example, with the use of a piezoelectric element. In embodiments, an ejector element having a different configuration may be used with fluid ejection chip  130 , for example, an ejector element that ejects fluid through the transfer of kinetic energy such as an electroactive polymer (EAP). 
         [0058]    A flow feature layer  160  may be disposed over the substrate  140 . Flow feature layer  160  may be disposed in a layered or otherwise generally planar abutting relationship with respect to substrate  140 . Flow feature layer  160  may be formed of, for example, a polymeric material. Flow feature layer  160  may be processed such that one or more flow features  162  are formed along and/or within flow feature layer  160 . In embodiments, flow features  162  may have geometry and/or dimensioning so that flow features  162  are configured to direct the flow of fluid through fluid ejection chip  130 . 
         [0059]    A nozzle layer  170  may be disposed over the flow feature layer  160 . In embodiments, nozzle layer  170  may be disposed in a layered relationship with flow feature layer  160 . In embodiments, nozzle layer  170  may be formed of, for example, a polymeric material. Nozzle layer  170  may be processed such that nozzles  172  are provided along an exposed surface of nozzle layer  170  as exit apertures for fluid being ejected from fluid ejection chip  130 . Accordingly, nozzles  172  may have geometry and/or dimensioning configured to direct the trajectory of fluid exiting fluid ejection chip  130 . Accordingly, fluid ejection chip  130  has an interior fluid volume for accommodating fluid. The various features of fluid ejection chip  130  described herein can be processed in a way so that a desired interior fluid volume is achieved. 
         [0060]    Respective fluid channels  144 , flow features  162 , and/or nozzles  172  may collectively form one or more fluid paths within fluid ejector chip  130 , such as fluid path F 1  and fluid path F 2  as shown, such that fluids can move from fluid reservoir  110 , through fluid ejection chip  130 , and exit through nozzles  172 . As described herein, fluid paths F 1  and F 2  are substantially open such that the opportunity of fluids to pool, trap, or otherwise become blocked is substantially minimized. Accordingly, the fluid channel  114  of fluid reservoir  110  and the interior bore  108  of body  102 , together with fluid paths F 1  and F 2 , provide a substantially linear and open path through which fluids can flow so that substantially all of a fluid deposited into fluid reservoir  110  is ejected through nozzles  172 . Further, by providing a fluid reservoir  110  having a desired interior volume, fluid ejector chip  130  can be provided such that a predetermined, discrete quantity of fluid is ejected onto a target surface while minimizing fluid waste due to the substantially linear and open fluid path provided by the interior configuration of fluid ejector chip  130 . 
         [0061]    Fluid ejection device  100  as described herein is suitable for use with, for example, relatively small quantities of fluid and accordingly may have a compact configuration. In this regard, fluid ejection device  100  may minimize manufacturing time and costs such that fluid ejection device  100  can be produced as a disposable device, e.g., a one-time use device. It may be desirable to use a disposable printhead design in a number of fields of application, for example, medical and laboratory testing, for example, to avoid sample contamination. 
         [0062]    Turning now to  FIG. 5 , a fluid ejection system according to an exemplary embodiment of the present invention is generally designated  1000 . Fluid ejection system  1000  includes a fluid ejection printer  200  which is configured to receive at least a portion of fluid ejection device  100 . In embodiments, fluid ejection printer  200  may receive a differently-configured fluid ejection device. Also shown is a testing surface T which may be, for example, a group of test tubes or an array of recessed reservoirs into which fluid can be deposited. In embodiments, testing surface T may be, for example, a testing slide or petri dish. In embodiments, testing surface T may be provided on a portion of fluid ejection printer  200 . 
         [0063]    Fluid ejection printer  200  includes a housing  202  and at least one carrier  210  for receiving a portion of fluid ejection device  100 . In this regard, carrier  210  may include an interior recess for receiving a portion of fluid ejection device  100  and/or may present a surface suitable for coupling with fluid ejection device  100 , for example, a clip, clamp, or tab structure, to name a few. 
         [0064]    Carrier  210  may also include an electrically conductive portion (not shown) for contacting and supplying electrical power through the electrical connector  120  ( FIG. 3 ) of fluid ejection device  100 , e.g., from an internal power source or an electrical power supply line. In this regard, carrier  210  provides a physical and electrical interface between fluid ejection device  100  and fluid ejection printer  200 . 
         [0065]    In embodiments, carrier  210  may be movable with respect to fluid ejection printer  200  along a series of rails with which carrier  210  is directly and/or indirectly slidable. As shown, carrier  210  may be slidably movable along a pair of lateral rails  212 , which are each in turn slidably movable along a pair of lengthwise rails  214 . In this regard, carrier  210  may be movable along a two-dimensional plane parallel to the testing surface T, e.g., an x-y grid 
         [0066]    Fluid ejection printer  200  may also include a controller  204  for effecting various electrically-powered functions, for example, firing of ejection actuators  150  ( FIG. 4 ) of fluid ejection device  100 . Accordingly, controller  204  may include or be electronically coupled with one or more processors that can read instructions from non-transitory computer memory. Electrically powered functions of fluid ejection printer  200  may be actuated manually by a user through an interface  216 , which may be, for example, knobs, toggles, and/or capacitive touchscreens, to name a few. 
         [0067]    Referring to  FIGS. 4A and 5 , in use, a user may insert or otherwise mount fluid ejection device  100  to carrier  210  of fluid ejection printer  200 . A quantity of fluid may then be deposited into the fluid reservoir  110  of fluid ejection device  100 , for example, with a pipette or dropper. In embodiments, a quantity of fluid may be deposited into fluid reservoir  110  by an automated device, for example, a portion of fluid ejection printer  200 . The quantity of fluid that can be accommodated in fluid ejection device  100  depends upon the interior volume of the fluid reservoir  110 , the volume of the interior bore  108  of body  102 , and the interior volume of the fluid ejection chip  130 . 
         [0068]    Upon depositing fluid into the fluid ejection device  100 , one or more electrical power pulses can be provided to fluid actuators  150  to cause flash vaporization and ejection of droplets of fluid from nozzles  172 . 
         [0069]    While particular embodiments of the invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications may be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.