Droplet ejector

Abstract

To provide an improved piezoelectric droplet ejector for a printhead that can be mounted with more nozzles.SOLUTION: A droplet ejector for a printhead comprises: a substrate having a mounting surface and an opposite nozzle surface; a nozzle-forming layer formed on at least a portion of the nozzle surface of the substrate; a fluid chamber defined at least in part by the substrate and at least in part by the nozzle-forming layer, the fluid chamber having a fluid chamber outlet defined at least in part by a nozzle portion of the nozzle-forming layer, the nozzle portion comprising an inner portion located closer to the fluid chamber outlet and an outer portion located closer to a periphery of the nozzle portion; and either or both of an inner actuator mechanism formed on the inner portion of the nozzle portion of the nozzle-forming layer and an outer actuator mechanism formed on the outer portion of the nozzle portion of the nozzle-forming layer.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a droplet ejector for a printhead, a printhead including a droplet ejector, A printer having a printhead with a droplet ejector and a droplet ejector for the printhead and a method for operating the detector. [Background technology]

[0002] Inkjet printers print images by ejecting droplets of ink onto a print medium (such as paper). They are used to reproduce digital images on a medium. Many inkjet printers The system controls the sequence of ejection of individual ink droplets from the inkjet nozzles of a printhead. It incorporates "drop-on-demand" technology, where the ink droplets are applied to the media. Each drop is ejected with sufficient momentum to eject the droplet. This allows drop-on-demand inkjet printers to print a continuous stream of ink droplets. This is a continuous ink produced by pumping ink through a fine nozzle. It is differentiated from inkjet devices.

[0003] The two most commercially successful drop-on-demand technologies are thermal inkjet printing and The printers are thermal inkjet printers and piezo inkjet printers. In a printer, the printing fluid must contain a volatile component, such as water. This results in spontaneous nucleation of bubbles in the volatile fluid, forcing droplets of the fluid through the nozzle. Piezo inkjet printers instead use piezoelectric actuators in the walls of the fluid chamber. The piezoelectric actuator is deflected by the deformation of the piezoelectric element, This induces a pressure change in the printing fluid stored in the fluid chamber, which in turn causes the nozzle Droplets are ejected through the nozzle.

[0004] Thermal inkjet printers are only used to jet very small amounts of printing fluid. It is not possible to do this (because the fluid must exhibit the appropriate volatility). Regular inkjet printers also suffer from the problem of dried ink residue building up on the heating elements. This can cause kogation, which can affect the use of the printer. The possible life span is shortened.

[0005] Piezo inkjet printers can be used with a wide range of fluids and are suitable for use in applications where kogation does not occur. As a result, they have a longer operating life than thermal inkjet printers. Therefore, compared to thermal inkjet printheads, existing piezoelectric technology typically requires Only a very low number of nozzles per lint head is achievable. Summary of the Invention [Problem to be solved by the invention]

[0006] Aspects of the present invention are improvements for printheads that can achieve higher nozzle counts. It is an object of the present invention to provide a piezoelectric liquid drop emitter having a piezoelectric effect. [Means for solving the problem]

[0007] A first aspect of the present invention provides a droplet emitter for a printhead. The droplet emitter comprises: a substrate having a nozzle surface and an opposite nozzle surface; a nozzle forming layer formed by the substrate and a nozzle forming layer formed by the substrate; and a fluid chamber defined by at least a portion of the nozzle. The forming layer has a fluid chamber outlet defined by a nozzle portion.

[0008] The nozzle portion of the nozzle forming layer typically includes a nozzle passage extending from the fluid chamber through the fluid chamber outlet. It acts as a diaphragm to eject fluid (e.g., (The diaphragm is typically movable.) The diaphragm is typically flexible. When the diaphragm moves towards the fluid chamber ( That is, by moving (e.g., flexing) the fluid chamber, typically , the fluid is discharged through the fluid chamber outlet.

[0009] The droplet emitter is typically formed by forming a nozzle portion (e.g., a diaphragm) of a nozzle-forming layer. At least one actuator mechanism (e.g., one At least one actuator mechanism (or a plurality of actuators) is further provided. For example, one or more actuators typically act to move nozzles of a nozzle-forming layer when actuated. configured to move or flex a portion of the valve (e.g., a diaphragm) (e.g., positioned) (i.e., moved or flexed in such a way during use) (I).

[0010] At least one actuator mechanism (e.g., one or more actuators) , including an inner actuator mechanism (e.g., one or more inner actuators) For example, the inner actuator mechanism may be For example, one or more inner actuators are typically located adjacent to the fluid chamber outlet. A nozzle forming layer is formed on at least a part of a nozzle portion (e.g., a diaphragm). That is, the inner actuator mechanism (e.g., one or The plurality of inner actuators) are typically formed in the nozzle portion of the nozzle forming layer (e.g., A nozzle formed near the fluid chamber outlet from the periphery (e.g., outer periphery) of the diaphragm. An actuator formed on at least a portion of the nozzle portion (e.g., diaphragm) of the layer. It is an eta mechanism.

[0011] At least one actuator mechanism (e.g., one or more actuators) , including an outer actuator mechanism (e.g., one or more outer actuators) For example, the outer actuator mechanism may be For example, one or more outer actuators) are typically located in the nozzle portion of the nozzle forming layer ( For example, the nozzles of the nozzle-forming layer are adjacent to the peripheral portion (for example, the outer periphery) of the diaphragm. An actuator mechanism formed on at least a portion of a support portion (e.g., a diaphragm). That is, the outer actuator mechanism (e.g., one or more outer actuators) The nozzle portion of the nozzle forming layer (e.g., The nozzle portion (e.g., the nozzle forming layer) adjacent to the peripheral portion (e.g., the outer periphery) of the diaphragm For example, an actuator mechanism formed on at least a portion of a diaphragm.

[0012] The droplet emitter may include an inner actuator mechanism (e.g., one or more inner actuators). Both the actuator mechanism (e.g., one or more outer actuators) Alternatively, the droplet emitter may include an internal actuator mechanism (e.g. , one or more inner actuators) or an outer actuator mechanism (e.g., one or may have multiple outer actuators), but not both. The presence of an internal actuator mechanism (e.g., one or more internal actuators) is not necessary. The presence of an external actuator mechanism (e.g., one or more external actuators) does not imply that the outer actuator mechanism (e.g., The presence of an outer actuator (or actuators) does not necessarily mean that an inner actuator mechanism (even The term "insertion" does not imply the presence of an internal actuator (e.g., one or more internal actuators).

[0013] The nozzle portion (e.g., diaphragm) of the nozzle-forming layer typically comprises an inner portion and It comprises (eg consists of) an outer portion.

[0014] The inner portion of the nozzle portion (e.g., diaphragm) of the nozzle-forming layer is typically The nozzle portion of the nozzle-forming layer is located adjacent to the outlet of the fluid chamber. The inner portion of the nozzle (e.g., diaphragm) is typically a nozzle forming layer of the nozzle portion. The nozzle portion (e.g., diaphragm) of the nozzle is connected to the fluid chamber from its peripheral portion (e.g., outer periphery). The nozzle portion of the nozzle forming layer (for example, the diaphragm) is located in the vicinity of the nozzle outlet. The inner portion of the nozzle abuts the fluid chamber outlet (i.e., the fluid chamber The nozzle portion of the nozzle-forming layer (e.g., a diamond layer) may be a portion extending to the nozzle outlet. The inner portion of the nozzle portion at least partially surrounds the fluid chamber outlet. The inner portion of the nozzle portion (e.g., diaphragm) of the nozzle-forming layer may be The nozzle portion may be the portion that completely surrounds the fluid chamber outlet. The inner portion of the nozzle portion (e.g., diaphragm) includes a fluid chamber outlet. (i.e., the fluid chamber outlet may be a nozzle portion of the nozzle forming layer (e.g. For example, the diaphragm may extend through an inner portion of the diaphragm.

[0015] The outer portion of the nozzle portion (e.g., diaphragm) of the nozzle-forming layer is typically The nozzle portion of the nozzle forming layer is formed on the peripheral edge (e.g., the diaphragm) of the nozzle portion. The nozzle portion (for example, the nozzle forming layer) is adjacent to the nozzle forming layer. The outer portion of the diaphragm is typically a nozzle-shaped nozzle portion from the fluid chamber outlet. Adjacent to the periphery (e.g., outer periphery) of the nozzle portion (e.g., diaphragm) of the layer The nozzle portion (for example, the diaphragm) of the nozzle-forming layer is provided on the outer side of the nozzle portion. The nozzle portion is an inner portion of the nozzle portion (e.g., a diaphragm) of the nozzle forming layer. The nozzle of the nozzle-forming layer may be a portion that abuts against the nozzle of the nozzle-forming layer (i.e., extends to the inner portion). The outer portion of the nozzle (e.g., the diaphragm) typically comprises at least Partially around the inner portion of the nozzle portion (e.g., diaphragm) of the nozzle forming layer The nozzle portion (for example, the diaphragm) of the nozzle-forming layer is provided on the outer side of the nozzle portion. The nozzle portion is an inner portion of the nozzle portion (e.g., a diaphragm) of the nozzle forming layer. The nozzle portion of the nozzle-forming layer (e.g., The outer portion of the nozzle portion of the nozzle forming layer (e.g., the diaphragm) is The nozzle portion ( For example, the outer portion of the nozzle portion of the nozzle forming layer (e.g. the diaphragm) For example, the diaphragm) is in contact with the peripheral portion (for example, the outer periphery) of the The nozzle portion (e.g., diaphragm) of the nozzle-forming layer may be a portion extending in the direction of the nozzle. The outer portion is a nozzle portion of the nozzle forming layer (e.g., a diaphragm). The nozzle portion (e.g., the diaphragm) of the nozzle forming layer and the peripheral portion (e.g., the outer It may be a portion extending between the inner surface of the support member and the outer surface of the support member.

[0016] The inner portion of the nozzle portion of the nozzle forming layer is typically curved during actuation of the nozzle forming layer. The outer portion of the nozzle portion of the nozzle forming layer is typically a portion of the nozzle forming layer. The outer and inner portions are typically curved portions when actuated. When bending, they curve in opposite directions (i.e., they face in opposite directions). When viewed from a direction (e.g., from a point outside the fluid chamber), in operation, the inner portion and One of the outer portions typically appears to be curved inward, and the other of the inner and outer portions typically appears to be curved inward. Typically it appears to be curved outward.

[0017] At least one actuator mechanism (e.g., at least one inner and / or outer The nozzle portion of the nozzle forming layer is a first actuator mechanism. a nozzle portion having an outer portion curved in a second sense opposite to the first sense; may be configured to bend (i.e., bend when activated) .

[0018] The inner and outer portions of the nozzle portion (e.g., diaphragm) of the nozzle-forming layer are In combination, the nozzle portion (for example, a diaphragm) of the nozzle forming layer can be formed in its entirety. Cut.

[0019] Wherein the inner part is the inner half of the nozzle part and the outer part is the outer half of the nozzle part The interface between the inner and outer portions is the outer edge of the fluid chamber outlet and nozzle portion. and may extend around the fluid chamber outlet for about 50% of the distance between.

[0020] The inner portion may comprise about 50% of the surface area of ​​the nozzle portion. The inner portion may comprise less than about 50% of the surface area of ​​the nozzle portion. The outer portion includes more than 50% of the surface area of ​​the nozzle portion (including the inner portion and The areas of the outer portions together typically constitute the total surface area of ​​the nozzle portion. The inner portion comprises approximately 25% of the surface area of ​​the nozzle portion, and the outer portion comprises approximately 10% of the surface area of ​​the nozzle portion. (The combined area of ​​the inner and outer portions typically comprises approximately 75% of the nozzle portion.) (may comprise the total surface area).

[0021] The inner and outer portions of the nozzle portion (e.g., diaphragm) of the nozzle-forming layer are The inner portion of the nozzle portion (e.g., diaphragm) of the nozzle-forming layer may be disposed on the axis. The nozzle portion (e.g., the die portion) of the nozzle-forming layer may be arranged concentrically. The inner and outer portions of the nozzle forming layer may be geometrically similar to each other. The inner and outer portions of the nozzle portion (e.g., diaphragm) of each nozzle forming The nozzle portion of the layer (e.g., the diaphragm) may be geometrically similar to the nozzle portion of the layer. The inner and outer portions of the nozzle portion (e.g., diaphragm) of the fluid chamber outlet may be arranged coaxially (e.g., concentrically) around

[0022] The inner and outer portions of the nozzle portion (e.g., diaphragm) of the nozzle-forming layer are In each case, the nozzle portion (for example, the diaphragm) of the nozzle forming layer (the nozzle forming layer (for example The nozzle portion (e.g., the diaphragm) of the nozzle forming layer is formed in the plane of the nozzle portion (e.g., the diaphragm). In some cases, the thickness of the film may extend along approximately 50% of its width (as measured in cross section along its major axis). For example, the nozzle portion (e.g., diaphragm) of the nozzle-forming layer may be substantially circular (e.g., For example, an annular shape, and the inner and outer portions of the nozzle forming layer (for example, a diaphragm) Each of the first and second grooves is substantially annular and concentrically arranged, with the outer portion extending around the inner portion. The inner portion is located at the outer radius of the nozzle portion (e.g., diaphragm) of the nozzle-forming layer. The outer radius is about 50%, and the outer portion is a nozzle portion of the nozzle forming layer (e.g., a diamond The inner radius of the nozzle portion of the nozzle forming layer (e.g., the nozzle portion of the nozzle forming layer) is about 50% of the outer radius of the nozzle portion of the nozzle forming layer (e.g., the nozzle portion of the nozzle forming layer). The outer radius of the diaphragm may be approximately equal to the outer radius of the diaphragm.

[0023] The inner actuator mechanism (e.g., one or more inner actuators) may be In this case, typically the inner portion of the nozzle portion (e.g., the diaphragm) of the nozzle-forming layer An actuator mechanism (eg, one or more actuators) formed on the An outer actuator mechanism (e.g., one or more outer actuators) is present. In this case, typically, the nozzle portion (e.g., the diaphragm) of the nozzle-forming layer is provided on the outer portion of the nozzle-forming layer. A formed actuator mechanism (eg, one or more actuators).

[0024] The droplet emitter may include an inner actuator mechanism (e.g., one or more inner actuators). The droplet emitter includes only an outer actuator mechanism (e.g., one or more outer actuators). In other words, the droplet ejector may not have a nozzle-forming layer. At least one actuator formed on an inner portion of the nozzle portion (e.g., a diaphragm) of the nozzle. a droplet ejector mechanism (e.g., at least one actuator), Any nozzle portion (e.g., diaphragm) formed on the outer portion of the nozzle-forming layer There may also be no actuator mechanism (eg, no actuator).

[0025] Alternatively, the droplet emitter may be configured with an external actuator mechanism (e.g., one or more external actuator) and the droplet emitter has an inner actuator mechanism (e.g., or multiple inner actuators). At least one of the nozzle portions (e.g., diaphragms) formed on the outer side of the nozzle portion of the nozzle-forming layer and a liquid crystal display device, comprising: The drop emitters are formed in an inner portion of the nozzle portion (e.g., a diaphragm) of the nozzle forming layer. The actuator may not have any actuator mechanism (e.g., actuator) attached to it. do.

[0026] The inner actuator mechanism (e.g., one or more inner actuators) when actuated Less than 50%, or more typically less than 40%, of the nozzle portion of the nozzle-forming layer is deformed to the may be more typically formed less than 30%.

[0027] The outer actuator mechanism (e.g., one or more outer actuators) when actuated Less than 50%, or more typically less than 40%, of the nozzle portion of the nozzle-forming layer is deformed to the may be more typically formed less than 30%.

[0028] The inventors have surprisingly found that only the inner actuator mechanism or the outer actuator mechanism By providing only the nozzle portion of the nozzle forming layer, it is possible to form a nozzle hole in the nozzle forming layer. (i.e., the nozzle portion of the nozzle forming layer is provided on both the inner and outer portions of the nozzle portion. In comparison with known droplet emitters in which a single actuator (such as a burlap actuator) is provided, It was found that the droplet ejection efficiency could be improved.

[0029] For example, the droplet emitter may include an inner actuator mechanism (e.g., one or more inner actuators). In embodiments that include only a droplet ejector, the droplet ejector typically has a first direction, in use. Direct deflection of an inner portion of the nozzle portion of the nozzle-forming layer (e.g., in a first orientation) The nozzles in the nozzle-forming layer are driven by the inner actuator mechanism. Since the part is typically fixed in position at its periphery (i.e., outer periphery), The deflection of the inner portion of the nozzle portion of the nozzle forming layer in the first direction (for example, the first direction) Therefore, typically, in a second direction (e.g., a second orientation) opposite the first direction A compensatory deflection of the outer portion of the nozzle portion of the nozzle forming layer is provided. Deflection of the nozzle portion of the nozzle-forming layer toward the nozzle (i.e., into the fluid chamber) typically causes Typically, the printing fluid is ejected from the fluid chamber through a fluid chamber outlet. Since the ethanol mechanism is provided only in the inner portion, the nozzle portion is As is known in the art, the nozzle portion of the nozzle-forming layer is generally formed by a nozzle-forming layer. This allows for a larger volume of actuators to be mounted than would be achieved if a single actuator mechanism were provided. In particular, the inventors , making the nozzle portion much larger than is possible with existing droplet emitters using similar materials. Deformed into a shape (and in particular a shape having an S-shaped cross section) that allows it to exert a discharge force This increase in ejection force allows the actuator to operate more efficiently. Efficient construction (and, for example, a smaller size than typically used in inkjet printers) The use of individually smaller actuators and, in the case of piezoelectric drop emitters, different pressure This makes it possible to use conductive materials.

[0030] Similarly, the droplet emitter may be coupled to an outer actuator mechanism (e.g., one or more outer actuators). In an embodiment with only an outer actuator mechanism, geometric constraints may result in In operation, the nozzle portion of the nozzle-forming layer is larger (than is possible using existing devices). It is ensured that the deformation occurs with a larger volume of deflection (e.g., by forming a more complex shape). To bear fruit.

[0031] In an alternative embodiment, the droplet emitter includes at least one internal actuator mechanism (e.g., For example, one or more inner actuators) and at least one outer actuator mechanism ( For example, one or more outer actuators may be provided. The ejector is formed by forming at least a part (such as a nozzle portion) of the nozzle forming layer (e.g., a diaphragm). For example, at least one (i.e., inner) actuator mechanism formed in the inner portion. and an inner actuator mechanism, At least a nozzle portion (e.g., a diaphragm) of the nozzle forming layer that also partially surrounds the nozzle portion At least one (i.e., outer) actuator formed in a portion (e.g., outer portion) and an actuator mechanism (e.g., one or more actuators).

[0032] In embodiments with both an inner actuator mechanism and an outer actuator mechanism, Actuation of the side actuator mechanism typically causes a The inner part of the nozzle portion of the nozzle forming layer is deflected, and the outer actuator mechanism is actuated. and typically in a second direction (e.g., a first orientation) opposite to the first direction (e.g., a first orientation). For example, in the second direction, the outer portion of the nozzle portion of the nozzle forming layer is deflected. Deflection of both the inner and outer portions of the nozzle section of the stratification typically results in the fluid channel The printing fluid is ejected from the nozzle through the fluid chamber outlet. In order to provide both the actuator mechanism and the outer actuator mechanism, the nozzle portion of the nozzle forming layer The deflection of both the inner and outer portions can be driven (e.g., at the same time) In this case too, a single actuator mechanism (and in particular , extending over most of the nozzle portion of the nozzle forming layer, e.g. Only a single actuator mechanism (overlapping both the side and outer portions) is provided. Larger volumetric deflections (e.g., more complex In particular, the present inventors have , using simultaneous actuation of the inner actuator mechanism and the outer actuator mechanism, the nozzle portion to a shape that allows it to exert a greater ejection force on the printing fluid. Again, this allows for a more efficient actuator. configuration (as well as individual printheads) that are more specific than those typically used in, for example, inkjet printers. This allows for the use of actuators with smaller output.

[0033] The drop emitter may include at least one electronic component integrated with the substrate. At least one electronic component includes at least one active electronic component (e.g., a transistor). Additionally or alternatively, the at least one electronic component may include at least At least one electronic component may include one passive electronic component (e.g., a resistor). The article includes at least one CMOS (i.e., complementary metal oxide semiconductor) integrated with a substrate. The body may contain electronic components.

[0034] With an inner actuator mechanism (i.e., the presence or absence of an outer actuator mechanism) In any embodiment, the inner actuator mechanism typically That is, the inner actuator mechanism typically at least partially surrounds an inner portion of the nozzle portion of the nozzle forming layer at least partially surrounding the fluid chamber outlet; The inner actuator mechanism may surround the fluid chamber outlet. The inner actuator mechanism may completely surround the fluid chamber outlet. The actuator mechanism may extend continuously around the fluid chamber outlet.

[0035] The inner actuator mechanism may consist of a single inner actuator.

[0036] The inner actuator mechanism includes two or more inner actuators, each of which is fluidly Two or more inner actuators may partially surround the chamber outlet. Typically, two or more inner actuators are spaced apart from one another. Generally, the nozzles are spaced apart from one another around the fluid chamber outlet (i.e., (Instead of being radially spaced apart from each other, the inner actuator mechanism The structure may extend discontinuously around the fluid chamber outlet.

[0037] The inner actuator mechanism may be substantially annular (ie, ring-shaped). The inner actuator mechanism may be centered on the fluid chamber outlet. The actuator mechanism may comprise two or more substantially annular inner actuators. The side actuator mechanism includes two or more inner actuators, each of which is partially shaped. are generally circular (i.e., each is a portion (e.g., a sector) of a circular body (i.e., Two or more partially annular inner The actuator is centered on the fluid chamber outlet (i.e., (sometimes arranged symmetrically around the periphery).

[0038] A droplet emitter having a substantially annular actuator mechanism centered about a fluid chamber outlet. By providing, the deflection of the nozzle portion of the nozzle forming layer is typically uniform (i.e., symmetric) around the outlet, thereby preventing droplets from The discharge becomes smooth.

[0039] The inner actuator mechanism may be a piezoelectric actuator mechanism, e.g., an inner piezoelectric actuator. The mechanism may be a

[0040] The inner actuator mechanism (i.e., the inner piezoelectric actuator mechanism) may include one or more The actuator may include an inner piezoelectric actuator.

[0041] At least one of the one or more inner piezoelectric actuators is typically driven by A piezoelectric body (i.e., an inner piezoelectric body) is provided between a pair of electrodes (i.e., a pair of inner driving electrodes). It is equipped with a power source.

[0042] Each of the one or more inner piezoelectric actuators is disposed between a corresponding pair of drive electrodes. The piezoelectric element is provided between a pair of corresponding inner drive electrodes. This may be the case.

[0043] The inner piezoelectric actuator mechanism may be substantially annular (i.e., ring-shaped). The inner piezoelectric actuator mechanism may be centered at the fluid chamber outlet.

[0044] The inner actuator mechanism may consist of a single inner piezoelectric actuator. The single inner piezoelectric actuator may be substantially annular. The data may be centered on the fluid chamber outlet.

[0045] The inner actuator mechanism may comprise two or more inner piezoelectric actuators. The inner actuator mechanism comprises two or more substantially annular inner piezoelectric actuators. The inner actuator mechanism may include two or more inner piezoelectric actuators. Each of the is partially circular in shape (i.e., each is a portion (e.g., a section) of a circular body. Two or more The partially annular inner piezoelectric actuator is centered on the fluid chamber outlet (i.e. In some cases, the nozzles are arranged symmetrically around the fluid chamber outlet.

[0046] The inner piezoelectric actuator is formed from several sections of the same continuous inner piezoelectric body. However, each of the inner piezoelectric actuators typically has its own A pair of driven electrodes are provided on the inside of each of the bodies.

[0047] The inner piezoelectric element may not extend into the outer portion of the nozzle portion of the nozzle forming layer. .

[0048] The nozzle portion of the nozzle forming layer has an inner portion and an outer portion, and the inner piezoelectric actuator mechanism The piezoelectric actuator mechanism is formed on the inner portion, and the outer portion has a piezoelectric actuator mechanism formed thereon. First, the inner piezoelectric actuator mechanism is actuated, and the inner piezoelectric actuator mechanism A force applied directly to the inner portion causes the inner portion to move in a first direction (i.e., a first direction). and the outer portion is connected to the inner portion and secured around a periphery of the outer portion. The support causes the deformation in a second, opposite sense (i.e., a second, opposite direction). There may be cases where this occurs.

[0049] The inner piezoelectric actuator mechanism typically Less than 50% of the surface area of ​​the nozzle that deforms during operation of the actuator mechanism, or more typically Typically, less than 40%, or more typically less than 30%, of the surface is formed.

[0050] The pair of inner drive electrodes may be electrically connected to a drive circuit. The drive circuit may include: Typically, a potential difference is selectively applied (i.e., actuated) between pairs of inner drive electrodes. When (for example, when in use) it is connected to a power source (for example, a voltage signal line) and an operating signal The piezoelectric element is configured to deflect the inner piezoelectric body when the inner piezoelectric body responds to a

[0051] One or more of the inner drive electrode pairs may include at least one electrode that is integral with the substrate. In some cases, the device is electrically connected to an electronic component.

[0052] With an outer actuator mechanism (i.e., the presence or absence of an inner actuator mechanism) In any embodiment, the outer actuator mechanism typically That is, the outer actuator mechanism typically at least partially surrounds , outside the nozzle portion of the nozzle-forming layer at least partially surrounding the fluid chamber outlet. is formed in parts.

[0053] The outer actuator mechanism may surround the fluid chamber outlet. The actuator mechanism may completely surround the fluid chamber outlet. The structure may extend continuously around the fluid chamber outlet.

[0054] The outer actuator mechanism may consist of a single outer actuator.

[0055] The outer actuator mechanism includes two or more outer actuators, each of which is fluidly Two or more outer actuators may partially surround the chamber outlet. Typically, they are spaced apart from one another around the fluid chamber outlet (i.e., semi-circular). (Instead of being spaced radially apart). Therefore, the outer actuator mechanism is , may extend discontinuously around the fluid chamber outlet.

[0056] The outer actuator mechanism may be substantially annular (ie, ring-shaped). The outer actuator mechanism may be centered on the fluid chamber outlet. The actuator mechanism may comprise two or more substantially annular outer actuators. The side actuator mechanism comprises two or more outer actuators, each of which is partially shaped. are generally circular (i.e., each is a portion (e.g., a sector) of a circular body (i.e., Two or more partially annular outer The actuator is centered on the fluid chamber outlet (i.e., (sometimes arranged symmetrically around the periphery).

[0057] A droplet emitter having a substantially annular actuator mechanism centered about a fluid chamber outlet. By providing, the deflection of the nozzle portion of the nozzle forming layer is typically uniform (i.e., symmetric) around the outlet, thereby preventing droplets from The discharge becomes smooth.

[0058] The outer actuator mechanism may be a piezoelectric actuator mechanism, e.g., an outer piezoelectric actuator. The mechanism may be a

[0059] The outer actuator mechanism (i.e., the outer piezoelectric actuator mechanism) may include one or more The actuator may include an outer piezoelectric actuator.

[0060] At least one of the one or more outer piezoelectric actuators is typically driven by A piezoelectric body (i.e., an outer piezoelectric body) is provided between a pair of electrodes (i.e., a pair of outer driving electrodes). It is equipped with a power source.

[0061] Each of the one or more outer piezoelectric actuators is disposed between a corresponding pair of drive electrodes. The piezoelectric element is provided between a pair of corresponding outer drive electrodes (i.e., an outer piezoelectric element provided between a pair of corresponding outer drive electrodes). This may be the case.

[0062] The outer piezoelectric actuator mechanism may be substantially annular (i.e., ring-shaped). The outer piezoelectric actuator mechanism may be centered on the fluid chamber outlet.

[0063] The outer actuator mechanism may consist of a single outer piezoelectric actuator. The single outer piezoelectric actuator may be substantially annular. The actuator may be centered about the fluid chamber outlet.

[0064] The outer actuator mechanism may comprise two or more outer piezoelectric actuators. The outer actuator mechanism comprises two or more substantially annular outer piezoelectric actuators. The outer actuator mechanism may include two or more outer piezoelectric actuators. Each of the is partially circular in shape (i.e., each is a portion (e.g., a section) of a circular body. Two or more The partially annular outer piezoelectric actuator is centered on the fluid chamber outlet (i.e. In some cases, the nozzles are arranged symmetrically around the fluid chamber outlet.

[0065] The outer piezoelectric actuator is formed from several sections of the same continuous outer piezoelectric body. However, each of the outer piezoelectric actuators typically has its own A driven electrode is provided on each of the outside of the body.

[0066] The outer piezoelectric element may not extend into the inner portion of the nozzle portion of the nozzle forming layer. .

[0067] The nozzle portion of the nozzle forming layer has an outer portion and an inner portion, and the outer piezoelectric actuator mechanism The piezoelectric actuator mechanism is formed on the outer portion, and the inner portion has a piezoelectric actuator mechanism formed thereon. First, the outer piezoelectric actuator mechanism is actuated to generate a piezoelectric force. A force applied directly to the outer portion causes the outer portion to move in a first direction (i.e., a first direction). and the inner portion is connected to and held within the outer portion. may be deformed in a second opposite sense (ie, a second opposite direction) due to

[0068] The outer piezoelectric actuator mechanism typically Less than 50% of the surface area of ​​the nozzle that deforms during operation of the actuator mechanism, or more typically Typically, less than 40%, or more typically less than 30%, of the surface is formed.

[0069] The outer drive electrode pair is connected to the drive circuit (e.g., if present, the inner drive electrode pair is The drive circuitry is typically When actuated (i.e., when a potential difference is selectively applied between a pair of outer drive electrodes), For example, in use, the actuator may be connected to a power source (e.g., a voltage signal line) and responsive to an actuation signal. When the piezoelectric element is pressed against the outer piezoelectric body, the outer piezoelectric body is deflected.

[0070] One or more of the outer drive electrode pairs may include at least one In some cases, the device is electrically connected to an electronic component.

[0071] In embodiments with both an inner actuator mechanism and an outer actuator mechanism, The side actuator mechanism typically at least partially encapsulates the inner actuator mechanism. That is, the outer actuator mechanism typically surrounds the nozzles of the nozzle-forming layer. at least partially surrounding an inner actuator mechanism formed on an inner portion of the portion It is formed on the outer portion of the nozzle portion of the nozzle forming layer.

[0072] The outer actuator mechanism may surround the inner actuator mechanism. The actuator mechanism may completely surround the inner actuator mechanism. The actuator mechanism may extend continuously around the inner actuator mechanism. do.

[0073] The outer actuator mechanism comprises two or more outer actuators, each of which is connected to an inner It may partially enclose the actuator mechanism. Two or more outer actuators are typically spaced apart from one another around the periphery of the inner actuator mechanism. Thus, the outer actuator mechanism extends discontinuously around the inner actuator mechanism. This may be the case.

[0074] The inner actuator mechanism typically is connected to a fluid chamber outlet (e.g., (i.e., closer to the periphery of the actuator mechanism) The outer actuator mechanism is typically driven from the fluid chamber outlet (e.g., the periphery of the body chamber outlet) (These are provided as guidelines.)

[0075] The outer actuator mechanism is typically spaced apart ( 3. The axially extending plates 112 and 114 are arranged radially (i.e., in a radial direction).

[0076] Both the inner actuator mechanism and the outer actuator mechanism are connected to the fluid chamber outlet. The inner actuator mechanism and the outer actuator mechanism may be coaxial. The inner actuator mechanism and the outer actuator mechanism may be disposed on the Both the inner actuator mechanism and the outer actuator mechanism may be concentric. The inner actuator may be symmetrically formed around the fluid chamber outlet. Both the mechanism and the outer actuator mechanism may be concentrically arranged.

[0077] A droplet emitter having a substantially annular actuator mechanism centered about a fluid chamber outlet. By providing, the deflection of the nozzle portion of the nozzle forming layer is typically uniform (i.e., symmetric) around the outlet, thereby preventing droplets from The discharge becomes smooth.

[0078] The inner actuator mechanism may be a piezoelectric actuator mechanism, e.g., an inner piezoelectric actuator. and / or the outer actuator mechanism is a piezoelectric actuator mechanism, e.g. For example, the inner actuator mechanism may be an outer piezoelectric actuator mechanism. By calling it an actuator mechanism, it is necessarily assumed that the outer actuator mechanism is a piezoelectric actuator. It is understood that there is no meaning to the eta mechanism (i.e., the outer piezoelectric actuator mechanism). Similarly, the outer actuator mechanism may be referred to as the outer piezoelectric actuator mechanism. This forces the inner actuator mechanism to be a piezoelectric actuator mechanism (i.e. It will be understood that this does not mean that the actuator is an electric actuator mechanism. One of the actuator mechanism and the outer actuator mechanism is a piezoelectric actuator mechanism ( i.e., either the inner piezoelectric actuator mechanism or the outer piezoelectric actuator mechanism) and the other of the inner actuator mechanism and the outer actuator mechanism is a non-piezoelectric actuator. actuator mechanism (i.e., outer non-piezoelectric actuator mechanism or inner non-piezoelectric actuator mechanism) Alternatively, it may be an inner actuator mechanism and an outer actuator mechanism. Both the actuator mechanism and the piezoelectric actuator mechanism (i.e., the inner piezoelectric actuator mechanism) The actuator may be a piezoelectric actuator mechanism.

[0079] The inner actuator mechanism (e.g., inner piezoelectric actuator mechanism) may include one or more and an outer actuator mechanism (e.g., an outer piezoelectric actuator) The actuator mechanism may include one or more external piezoelectric actuators. In the embodiment, the one or more outer piezoelectric actuators are connected to the one or more inner piezoelectric actuators. The heater at least partially surrounds the heater.

[0080] Each of the one or more inner piezoelectric actuators is disposed between a corresponding pair of drive electrodes. The piezoelectric element is provided between a pair of corresponding inner drive electrodes. Each of the one or more outer piezoelectric actuators may be connected to a corresponding driving electrode. A piezoelectric body provided between the pair (i.e., an outer piezoelectric body provided between the corresponding outer driving electrode pair) However, the piezoelectric element of the inner actuator mechanism may be located on the inner side. By calling it a piezoelectric body, it is meant that the outer actuator mechanism necessarily comprises an outer piezoelectric body. It is understood that there is no point (e.g., the outer actuator mechanism may be non-piezoelectric). Similarly, the piezoelectric body of the outer actuator mechanism is called the outer piezoelectric body. There is no sense in which the actuator mechanism necessarily has an inner piezoelectric body (e.g., It will be understood that the actuator mechanism may be non-piezoelectric.

[0081] Both the inner and outer piezoelectric bodies are formed from several sections of the same continuous piezoelectric body. Alternatively, the inner and outer piezoelectric elements may be separate (i.e., connected). The inner and outer piezoelectric elements may be spaced apart from each other. In some cases, the equipment is arranged in a

[0082] Both the inner drive electrode pair and the outer drive electrode pair are electrically connected to a drive circuit. The drive circuitry typically selectively applies a first potential difference between the pair of inner drive electrodes. When applied to (i.e., when activated (e.g., in use), a power source (e.g., a voltage signal When connected to the line and responsive to an actuation signal, the piezoelectric element and applying a second potential difference between the pair of outer drive electrodes to move the piezoelectric element in a direction opposite to the first direction. The outer piezoelectric body is configured to deflect in a second direction.

[0083] The drive circuitry is configured to drive the droplet ejector when the droplet ejector is in use and connected to a power source (e.g., a voltage signal line). Then, a first potential difference is applied between the pair of inner drive electrodes to drive the inner piezoelectric element in a first orientation. bending the body and applying a second potential difference between the pair of outer drive electrodes to achieve the first orientation and The outer piezoelectric body can be configured to curve in a second, opposite direction.

[0084] The first potential difference and the second potential difference typically have similar (e.g., the same) magnitude. The first potential difference and the second potential difference typically have opposite polarities.

[0085] One or more of the inner and outer drive electrode pairs are aligned with the substrate. The at least one electronic component may be electrically connected to the at least one electronic component embodied in the at least one semiconductor laser.

[0086] One or more inner piezoelectric elements (if present) and / or one or more outer piezoelectric elements The dielectric, if present, is made of one or more piezoelectric materials that can be processed at temperatures below 450°C. The piezoelectric material may include (eg, be formed from) such a piezoelectric material.

[0087] Above 300°C, integrated electronic components (e.g., CMOS electronics) typically At temperatures above 450°C, they begin to degrade, impairing the operation of the device and reducing its efficiency. Integrated electronics (e.g., CMOS electronics) are typically much more substantial. Therefore, by using piezoelectric materials that can be processed at temperatures below 450°C, and processing the piezoelectric actuator without causing substantial damage to the electronic components (e.g., For example, it can be integrated with the electronic components (eg, of the driver circuitry).

[0088] The one or more inner piezoelectric elements and / or the one or more outer piezoelectric elements are heated to 300° C. The piezoelectric material may include one or more piezoelectric materials that can be processed at temperatures below 1000 K (e.g., Use of piezoelectric materials that can be processed at temperatures below 300°C. This allows the piezoelectric actuator to be processed with even less damage to the electronic components (e.g. It can be integrated with electronic components (for example, the drive circuit). It can be processed at temperatures below 300°C. The use of piezoelectric materials typically allows for the fabrication of a single substrate (e.g., Achieving higher yields of functional devices from mass production of multiple fluid ejectors (from wafers) It is possible.

[0089] By integrating the piezoelectric actuator with electronic components (e.g., drive electronics), Typically, in existing devices, any piezoelectric printhead microchip Reduces or eliminates the need for separate (separate) drop emitter drive electronics Thus, many droplet emitters can be closely packed together on a single chip, This allows for more nozzles per chip and reduces the overall size of the printhead. and allows for a higher density of printhead nozzles than is achievable with existing piezoelectric printheads. Other advantages associated with integration on a single print head chip include: Reduction in final manufacturing costs, reduction in printer system costs, modularization, device Improvements to printer systems, such as improved reliability, redundancy and throughput .

[0090] Piezoelectric materials that can be processed at less than 450°C (or even less than 300°C) typically require higher temperatures. Poorer piezoelectric properties (e.g. lower piezoelectric constant) than piezoelectric materials that require high temperature processing For example, high-temperature processable piezoelectric materials such as lead zirconate titanate (PZT) The piezoelectric actuators formed are made of low-temperature processable piezoelectric materials such as aluminum nitride (AlN). All other factors being equal, it is an order of magnitude more efficient than piezoelectric actuators made from It can exert a great force.

[0091] However, the inventors have By providing an ator mechanism, it is possible to reduce the amount of The actuator is mounted on the wall of the fluid chamber farther away from the fluid chamber outlet. The droplet ejection rate is sufficiently fast to enable the use of low-temperature processable piezoelectric materials. It was found that the droplet ejection efficiency of the ejector can be improved. It is the particular structure of the droplet emitter of the present invention that allows the use of This allows integration of the drop emitter with the driving electronics.

[0092] In particular, application of an electric field (i.e., a potential difference) between one or more pairs of inner drive electrodes Typically, deformation of one or more inner piezoelectric actuators is induced, which drives the outer drive Application of an electric field (i.e., a potential difference) between one or more pairs of electrodes typically produces a Deformations are induced in one or more of the outer piezoelectric actuators, each of which causes a nozzle A highly damped vibration of the nozzle portion of the forming layer is provided. The vibrations result in an oscillating pressure field within the fluid chamber, which causes the droplets to move through the fluid chamber outlet. The discharge is driven. (The discharge of the fluid chamber located farther away from the fluid chamber outlet.) By displacing the nozzle portion of the nozzle-forming layer (rather than displacing the wall), the The fluid pressure required to eject a droplet is relatively small, and therefore the actuation force is relatively small. This facilitates the use of low temperature processable piezoelectric materials with lower piezoelectric constants. become.

[0093] The force exerted by a piezoelectric actuator containing a low-temperature processable piezoelectric material is Because they are relatively small (compared to devices using piezoelectric actuators containing Therefore, the fluid pressure achieved is relatively small, so adjacent fluid chambers on the printhead Acoustic crosstalk between members (due to sound waves propagating through the printhead) is reduced. The reduced pressure reduces the fluid compressibility and reduces the likelihood of acoustic crosstalk. Reduced levels of acoustic crosstalk allow for faster print times without compromising print quality. This allows for closer packing of adjacent drop emitters on the head.

[0094] The processing of the piezoelectric material typically includes deposition of said piezoelectric material. Further processing of the piezoelectric material after deposition (i.e., post-deposition processing of the deposited piezoelectric material, or “post-processing”) Processing of the piezoelectric material may also include baking (i.e., after deposition) the piezoelectric material. It may also include.

[0095] Piezoelectric materials that can be processed at temperatures below 450° C. (or even below 300° C.) are typically Piezoelectric materials that can be deposited at temperatures below 0°C (or below 300°C). Piezoelectric materials that can be processed at temperatures below 300°C are typically processed at temperatures above 450°C (or 300°C). No post-deposition treatment (such as post-deposition annealing) at temperatures above 100°C is required. Thus, piezoelectric materials that can be processed at temperatures below 450° C. (or below 300° C.) are typically annealable (after deposition) at temperatures below 450°C (or below 300°C) (i.e. , if annealing of the piezoelectric material is required to make it piezoelectric) .

[0096] The piezoelectric material or materials are typically used when the piezoelectric actuator is heated to below 450° C. (or In order to make it possible to manufacture at temperatures below 450°C (or below 300°C), It is processable (e.g., depositable and, if necessary, annealable) at 450 Fabrication of piezoelectric actuators at temperatures below 300° C. (or below 300° C.) typically results in: Allows integration of the piezoelectric actuator with at least one electronic component integrated into the substrate become.

[0097] Thus, one or more inner piezoelectric elements and / or one or more outer piezoelectric elements is typically performed at a temperature of less than 450° C. (or less than 300° C.) (e.g., one or more It can be formed by deposition and, if necessary, annealing of several piezoelectric materials.

[0098] The piezoelectric material or materials are typically heated to a temperature of less than 450° C. (or less than 300° C.) It is temperature processable (e.g., it can be deposited and, if necessary, annealed). In other words, the temperature of the substrate is typically controlled by the processing (e.g., deposition) of one or more piezoelectric materials. During the heating process (sintering, and annealing if necessary), temperatures of 450°C (or 300°C) are not exceeded. The temperature of the substrate is typically 450° C. (or 300° C.) during the formation of the piezoelectric body. The temperature of the substrate is typically not reached or exceeded by the temperature of the piezoelectric actuator. During manufacturing, the temperature of the substrate does not reach or exceed 450°C (or 300°C). During the manufacture of the droplet emitter (e.g., the entire droplet emitter), temperatures of 450° C. (or 300° C.) may be reached. There are cases where it is neither exceeded nor exceeded.

[0099] The one or more inner piezoelectric bodies and / or the one or more outer piezoelectric bodies are typically can be deposited by one or more (e.g., low-temperature) physical vapor deposition (PVD) techniques. One or more inner piezoelectric bodies and / or one or more The outer piezoelectric element is typically heated to a temperature of less than 450° C. (or more preferably less than 300° C.). at room temperature (i.e., at the substrate temperature) by one or more (e.g., low-temperature) physical vapor deposition techniques. It is capable of being deposited (eg, deposited) by the above.

[0100] The one or more inner piezoelectric bodies and / or the one or more outer piezoelectric bodies are one or Several types of (e.g., low temperature) PVD depositable piezoelectric materials are included (e.g., such materials One or more inner piezoelectric bodies and / or one or more The outer piezoelectric body may include one or more (e.g., low-temperature) PVD deposited piezoelectric materials. (e.g., formed from such materials).

[0101] Physical vapor deposition (e.g., low-temperature physical vapor deposition) is a deposition method that includes the following: cathodic arc evaporation. deposition, electron beam physical vapor deposition, evaporative deposition, pulsed laser deposition, or sputter deposition The sputter deposition may include one or more sputtering sources. This can include sputtering of material from the get.

[0102] The piezoelectric material or materials are typically deposited at less than 450° C. (or less than 300° C.). The piezoelectric material or materials have a PV of less than 450°C (or less than 300°C). The one or more piezoelectric materials may have a deposition temperature of less than 450° C. (or 3 The one or more piezoelectric materials may have a sputtering temperature of less than 100° C. The deposition may have a post-deposition annealing temperature of less than 450° C. (or less than 300° C.). The deposition temperature, PVD deposition temperature, sputtering temperature or annealing temperature are typically It will be understood that this is the temperature of the substrate during each process.

[0103] One or more inner piezoelectric elements and / or one or more outer piezoelectric elements are one type of piezoelectric element. Alternatively, one or The inner piezoelectric elements and / or the outer piezoelectric element or elements may include two or more types of piezoelectric materials. It may be (eg, formed from) such a material.

[0104] The inner piezoelectric element or elements and / or the outer piezoelectric element or elements are made of aluminum. tungsten and nitrogen, and optionally scandium, yttrium, titanium, magnesium One or more selected from the group consisting of tungsten, hafnium, zirconium, tin, chromium, and boron The ceramic material may include (eg, be formed from) a ceramic material that includes the elements.

[0105] The inner piezoelectric element or elements and / or the outer piezoelectric element or elements are made of aluminum nitride. The material may include (e.g., be formed from) aluminum nitride (AlN). .

[0106] The inner piezoelectric element or elements and / or the outer piezoelectric element or elements are / is made of zinc oxide. The material may include (eg, be formed from) zinc oxide (ZnO).

[0107] The one or more piezoelectric materials may include aluminum nitride and / or zinc oxide (e.g., , aluminum nitride and / or zinc oxide).

[0108] The aluminum nitride may be comprised of high purity aluminum nitride. Alternatively, aluminum nitride The aluminum may contain one or more other elements (i.e., aluminum nitride). (It may contain aluminum nitride compounds.) Aluminum nitride is a compound of the following elements: That is, scandium, yttrium, titanium, magnesium, hafnium, zirconium The metal may include one or more of aluminum, tin, chromium, and boron.

[0109] The one or more inner piezoelectric bodies and / or the one or more outer piezoelectric bodies are made of nitrided sintered material. Scandium aluminum nitride (ScAlN) (e.g., The scandium in scandium aluminum nitride can be formed from ScAlN. The percentage of d is typically within manufacturability limits. 31 To optimize the piezoelectric constant For example, Sc x Al 1-x The value of x in N is typically 0 <x≦0.5 When the proportion of scandium increases, typically d 31 The value of is large The sintering effect in scandium aluminum nitride is The mass percent (i.e., weight percent) of indium is typically greater than 5%. The mass percent of scandium in scandium aluminum nitride (i.e., The percent by weight is typically greater than 10%. The mass percent (i.e., weight percent) of scandium in Greater than 0%. The mass percentage of scandium in scandium aluminum nitride (i.e., weight percent) is typically greater than 30%. The mass percent (i.e., weight percent) of scandium in aluminum is typically Typically, it is greater than 40%. The quality of scandium in scandium aluminum nitride The amount percentage (ie, weight percentage) may be up to 50%.

[0110] Aluminum nitrides, including aluminum nitride compounds (and in particular, scandium aluminum nitride) Aluminum and zinc oxide are preferably heated at temperatures below 450°C, or more preferably below 300°C. Aluminum nitride compounds (and in particular silicon nitride) are piezoelectric materials that can be deposited on a substrate. Aluminum nitride containing candium aluminum and zinc oxide are below 450°C, or more preferably at a temperature below 300° C., by physical vapor deposition (e.g., sputtering). Aluminum nitride compounds (and in particular Aluminum nitride, including scandium aluminum nitride, and zinc oxide are typically It is a piezoelectric material that does not require annealing after deposition.

[0111] The one or more inner piezoelectric elements and / or the one or more outer piezoelectric elements are heated to 450° C. Nitride deposited by physical vapor deposition at temperatures below, or more preferably below, 300° C. Aluminum (e.g., aluminum nitride compounds, e.g., scandium aluminum nitride) The material may include (eg, be formed from) zinc oxide.

[0112] The one or more inner piezoelectric bodies and / or the one or more outer piezoelectric bodies are one or Multiple III-V and / or II-VI semiconductors (i.e., those in Groups III and II of the Periodic Table) V and / or compound semiconductors containing elements from groups II and VI) (e.g. Such III-V and II-VI semiconductors are typically is a hexagonal wurtzite crystal The III-V and III-V crystallized in the hexagonal wurtzite crystal structure. and II-VI semiconductors typically lack piezoelectric properties due to their non-centrosymmetric crystal structures. It is sexuality.

[0113] The inner piezoelectric element(s) and / or the outer piezoelectric element(s) are non-ferroelectric. The piezoelectric material may include a ferroelectric material (e.g., formed or composed of a non-ferroelectric piezoelectric material). The plurality of piezoelectric materials may be one or more non-ferroelectric piezoelectric materials. typically requires poling under a strong applied electric field (i.e., after deposition) Non-ferroelectric piezoelectric materials typically do not require poling.

[0114] The one or more inner piezoelectric bodies and / or the one or more outer piezoelectric bodies are typically is less than 30 pC / N, or more typically less than 20 pC / N, or even more typically Piezoelectric constant d with magnitude less than 10 pC / N 31 The one or more piezoelectric materials include Typically, less than 30 pC / N, or more typically, less than 20 pC / N, or even better. The piezoelectric constant d has a magnitude typically less than 10 pC / N. 31 has.

[0115] The piezoelectric material or materials are typically CMOS compatible. or the piezoelectric materials typically do not contain substances that are damaging to CMOS electronic structures; Or, typically, they can be processed without the use of such materials (e.g., depositable, and It will be understood that the present invention can be applied to one or more of the following applications: The processing (e.g., deposition and, if necessary, annealing) of the piezoelectric material is typically Acid (e.g., strong acid, such as hydrochloric acid) and / or alkali (e.g., potassium hydroxide) Does not include the use of strong alkali.

[0116] The nozzle forming layer may comprise a nozzle plate. The nozzle plate is a single layer of material. Alternatively, the nozzle plate may be made up of two layers of (e.g., different) materials. The nozzle plates may be constructed of a laminate of one or more layers. One or more materials with a Young's modulus (i.e., tensile modulus) of Pa to 300 GPa The nozzle plate is made of silicon dioxide (SiO 2 ), silicon nitride (Si 3 N 4 ), Silicon carbide (SiC), silicon oxynitride (SiO x N y ) may be formed from one or more of do.

[0117] The nozzle forming layer may include an electrical interconnect layer. The electrical interconnect layer is typically , typically one or more electrical connections (e.g., electrical The electrical connection or connections (e.g., electrical wires) are typically made of gold. The wire is made of a metal or metal alloy. Suitable metals include aluminum, copper and tungsten. The electrical insulators are typically silicon dioxide (S iO 2 ), silicon nitride (Si 3 N 4 ) or silicon oxynitride (SiO x N y ) or other dielectric materials. It is being done.

[0118] An electrical interconnect layer is provided (e.g., formed) between the substrate and the nozzle plate. An electrical interconnect layer may be provided (e.g., formed) on the second side of the substrate. a nozzle plate is disposed (e.g., formed) on the electrical interconnect layer. The nozzle plate may have one or more apertures. 3, through which electrical connections can be made to the electrical interconnect layer.

[0119] The nozzle portion of the electrical interconnect layer forms at least a portion of the nozzle portion of the nozzle forming layer. The nozzle portion of the electrical interconnect layer may be constructed from a dielectric material. Alternatively, the electrical interconnect layer does not form part of the nozzle portion of the nozzle-forming layer. There are cases.

[0120] The inner drive electrode pair and the outer drive electrode pair are typically made of metal (titanium, platinum, aluminium, etc.). The inner drive is provided with one or more layers of a material such as aluminum, tungsten or alloys thereof. The pair of actuated electrodes and the pair of outer actuated electrodes may be stacked. The pair of electrodes and the pair of outer drive electrodes are made of aluminum-molybdenum (Al / Mb) stacked stacks. The inner drive electrode pair and the outer drive electrode pair are typically formed from At temperatures below 450° C. (or, more typically, below 300° C.) (i.e., substrate temperature 30° C.) or by (e.g., low temperature) PVD.

[0121] One or more of the inner drive electrode pair and the outer drive electrode pair include at least one The pair of inner drive electrodes and the pair of outer drive electrodes may be electrically connected to the electronic components. Each of the pole pairs may be electrically connected to at least one electronic component.

[0122] The drop emitter may comprise a drive circuit. Alternatively, the drive circuit may be The drive circuitry can typically form part of a printhead comprising an internal Generates the potential difference required to operate the actuator mechanism and the outer actuator mechanism To make.

[0123] The drop emitter may include a control circuit. Alternatively, the control circuit may include a The control circuitry can typically form part of a printhead that includes a drive Determines when to operate the circuit.

[0124] In embodiments in which the drop emitter includes a drive circuit, the drive circuit is typically integrated with the substrate. At least one electronic component typically forms part of the drive circuit. One or more of the pair of side drive electrodes and the pair of outer drive electrodes are electrically connected to a drive circuit. Each of the inner drive electrode pair and the outer drive electrode pair may be connected to a drive It may be electrically connected to the circuit.

[0125] At least one electronic component, if present, is disposed between one or more pairs of inner drive electrodes. configured to provide a (e.g., variable) potential difference (i.e., voltage) to At least one electronic component may be provided to the inner drive electrode. is configured to vary the potential difference (i.e., voltage) between one or more pairs of (i.e., changed during use).

[0126] At least one electronic component, if present, is disposed between one or more pairs of outer drive electrodes. configured to provide a (e.g., variable) potential difference (i.e., voltage) to At least one electronic component may be connected to the outer drive electrode. is configured to vary the potential difference (i.e., voltage) between one or more pairs of (i.e., changed during use).

[0127] The at least one electronic component applies a first potential difference between one or more pairs of the inner drive electrodes. and configured to provide a second potential difference between one or more pairs of the outer drive electrodes. At least one electronic component may be configured to simultaneously generate the first potential difference and the second potential difference. The first potential difference and the second potential difference are typically , and have similar (e.g., the same) magnitude. The first potential difference and the second potential difference are typically have opposite polarity.

[0128] The drive circuitry includes CMOS circuitry (e.g., CMOS electronics) integrated with the substrate. CMOS electronic components (e.g., CMOS devices that form part of a CMOS circuit) can be CMOS electronic components (i.e. CMOS electronic circuits) are typically fabricated using standard CMOS manufacturing methods. For example, an integrated CMO S electronic components are grown using the following methods: physical vapor deposition, chemical vapor deposition, electrochemical deposition, and molecular beam epitaxy. , Atomic Layer Deposition, Ion Implantation, Photopatterning, Reactive Ion Etching, Plasma The deposition may be performed using one or more of the following methods:

[0129] The droplet emitter includes an inner actuator mechanism and an outer actuator mechanism and a nozzle forming The protective layer may further comprise a protective layer over the layer. The protective layer is typically chemically inert. It is impermeable and / or fluid-repellent. The protective layer should have a low Young's modulus (i.e., tensile modulus). The Young's modulus of the nozzle forming layer (and, in particular, the nozzle plate) and / or the piezoelectric body is substantially smaller than that of the The protective layer typically has a Young's modulus of less than 50 GPa. The protective layer is made of one or more of polyimide or polytetrafluoroethylene (PTFE). The materials used are several polymeric materials, diamond-like carbon (DLC), negative or positive photoresists. Resist, or epoxy-based photoresist (Su-8, BCB, etc.), or any combination thereof The protective layer can be formed from a combination of these different materials having different fluid wetting properties. It may include two or more layers of material.

[0130] The droplet emitter is typically monolithic. The substrate, nozzle-forming layer, actuator, and a rotor mechanism, a fluid chamber, at least one electronic component (e.g., of the drive electronics), and The protective layers are typically integral (i.e., integral with one another). The ejector typically comprises a substrate, a nozzle forming layer, an actuator mechanism (e.g., drive electronics), at least one electronic component and a protective layer of the device through one or more deposition processes; A droplet emitter is typically manufactured by integrally forming one or more Individually formed components (e.g., individually formed substrates, nozzle-forming layers, actuators, etc.) The material is manufactured by bonding together the components (electronic mechanism, electronic components and / or protective layer) of the It is not.

[0131] The mounting surface of the substrate may include a fluid inlet aperture in fluid communication with the fluid chamber. be.

[0132] The fluid chamber may be substantially elongated. The fluid chamber typically accommodates the substrate. The fluid chamber typically extends from the mounting surface to the nozzle face. The fluid chamber typically extends along a direction substantially perpendicular to the surface of the nozzle. , extending between the fluid inlet aperture and the fluid chamber outlet.

[0133] The fluid chamber may be substantially circular in cross section through the plane of the substrate. , the cross section through the plane of the substrate may be substantially polygonal (e.g., the fluid chamber may have a cross section The fluid chamber may be multi-sided in cross section through the plane of the substrate. .

[0134] The fluid chamber may be substantially prismatic in shape. The longitudinal axis typically extends in a direction substantially perpendicular to the mounting surface and / or the nozzle surface. It continues to extend.

[0135] The fluid chamber may be substantially cylindrical in shape. The directional axis is typically along a direction substantially perpendicular to the mounting surface and / or the nozzle surface. It is extended.

[0136] The nozzle portion of the nozzle forming layer typically comprises a nozzle hole extending across the fluid chamber of the nozzle forming layer. The portion that extends thereby forming at least one wall of the fluid chamber.

[0137] The nozzle portion of the nozzle-forming layer typically projects beyond the substrate and is therefore are independently bendable.

[0138] The nozzle portion of the nozzle forming layer may be substantially annular.

[0139] The fluid chamber is substantially cylindrical and the nozzle portion of the nozzle forming layer is substantially annular. There may be cases where this occurs.

[0140] The fluid chamber is typically bounded by one or more fluid chamber walls. At least one of the one or more fluid chamber walls is typically At least one of the one or more fluid chamber walls is formed in part by , typically substantially perpendicular to the mounting surface and / or nozzle surface of the substrate (i.e. Vertical (i.e., perpendicular) fluid chamber walls typically Typically, multiple adjacent fluid chambers (and therefore fluid volumes) can be provided on a single printhead. The nozzles can be packed closer together, thereby increasing the nozzle density. The perpendicular (i.e. perpendicular) fluid chamber walls are typically formed by deep drilling using the Bosch process or the like. It is formed by reactive ion etching (DRIE).

[0141] The outer periphery of the nozzle portion of the nozzle forming layer may be substantially polygonal. The outer periphery of the nozzle portion of the nozzle forming layer may be multifaceted. The nozzle portion of the nozzle-forming layer may be square-shaped. The nozzle portion of the layer (e.g., the polygonal, multi-sided diamond, and / or square shape of the nozzle-forming layer) The nozzle portion of the nozzle forming layer may have rounded corners. Typically, the aperture is provided. The aperture may be substantially circular. The aperture may be substantially polygonal. The aperture may be multi-sided.

[0142] The fluid chamber has a cross section in the plane of the substrate that is substantially the same as the shape of the nozzle portion of the nozzle forming layer. For example, the nozzle portion of the nozzle forming layer may have rounded corners. If the cross section is square with rounded corners, the fluid chamber has a square cross section with rounded corners. There may be cases where this is possible.

[0143] The nozzle portion of the nozzle forming layer (i.e., the nozzle portion extends across the fluid chamber and thereby The nozzle-forming layer (that portion of the nozzle-forming layer forming at least one wall of the nozzle chamber) is disposed in the plane of the substrate. The cross section of the fluid chamber may be substantially similar in shape to the fluid chamber. If the chamber is substantially cylindrical (i.e. substantially circular in cross section), the nozzle forming layer The periphery of the nozzle portion is substantially circular.

[0144] The printhead can be an inkjet printhead. For jet printheads (e.g. as used in inkjet printheads) The droplet emitter may be an inkjet droplet emitter. It is possible.

[0145] The printhead is a functional flow head used in the manufacture of printed electronics. It may be configured to print fluids (i.e., liquids) of the body, etc.

[0146] The print head can be configured to print a biological fluid. Typically, biological macromolecules, e.g., polynucleotides such as DNA or RNA; The print head can be used to print biological or bioengineering materials such as diluents or reagents. The device may be adapted to print other fluids used in scientific applications.

[0147] The printhead may be a voxel printhead (i.e., a 3D printing, e.g., additive printing). A printer configured for use in additive printing. It can be a head.

[0148] A second aspect of the invention relates to a printhead comprising a plurality of droplet ejectors according to the first aspect of the invention. A plurality of droplet emitters (e.g., some or each of them) may be provided with a common For example, multiple droplet emitters may be integrated on a common substrate. There may be cases where this occurs.

[0149] The printhead may be an inkjet printhead. Each may be an inkjet drop emitter.

[0150] Printheads are used to manufacture printed electronics, etc. It may be configured to print a fluid.

[0151] The print head can be configured to print a biological fluid. Typically, biological macromolecules, e.g., polynucleotides such as DNA or RNA; The print head can be used to print biological or bioengineering materials such as diluents or reagents. The device may be adapted to print other fluids used in scientific applications.

[0152] The printhead may be a voxel printhead (i.e., a 3D printing, e.g., additive printing). The printhead may be configured for use in a laser printer.

[0153] A third aspect of the invention comprises one or more printheads according to the second aspect of the invention. Provide a printer.

[0154] A fourth aspect of the invention provides a method of operating a drop emitter according to the first aspect of the invention. The method typically includes actuating an inner actuator mechanism and / or an outer actuator. Activating the air mechanism, thereby displacing at least a portion of the nozzle portion of the nozzle forming layer. and resulting in the ejection of fluid from the fluid chamber through a fluid chamber outlet. Includes

[0155] The droplet emitter may include an inner actuator mechanism and an outer actuator mechanism. (i.e., the method includes: a substrate having a mounting surface and an opposing nozzle surface; A nozzle forming layer formed on at least a portion of the substrate and a substrate having a small thickness. A fluid chamber defined at least in part by the nozzle forming layer, a fluid chamber having a fluid chamber outlet defined by a nozzle portion of the nozzle forming layer; an inner actuator mechanism formed in at least a portion of the nozzle portion of the nozzle-forming layer; At least a nozzle portion of the nozzle forming layer at least partially surrounding the actuator mechanism. and an outer actuator mechanism formed in part thereof. (I).

[0156] The method includes a step of actuating both the inner actuator mechanism and the outer actuator mechanism. Both the inner and outer actuator mechanisms may include Actuation typically causes a displacement of at least a portion of the nozzle portion of the nozzle forming layer and a resulting Discharge of fluid from the fluid chamber through the fluid chamber outlet (i.e., Thus, the method typically involves the steps of: The method includes providing a fluid (ie, liquid) in the chamber.

[0157] activating an inner actuator mechanism and activating an outer actuator mechanism The steps are typically performed simultaneously (ie, at the same time).

[0158] The drive circuitry typically includes both an inner actuator mechanism and an outer actuator mechanism. Activate.

[0159] In an embodiment in which the inner actuator mechanism comprises one or more inner piezoelectric actuators. The method further comprises providing a first potential difference (i.e., voltage) between one or more pairs of the inner drive electrodes. The step of applying a voltage to the inner piezoelectric body or bodies to cause deflection of the inner piezoelectric body or bodies may include the step of: In an embodiment in which the side actuator mechanism comprises one or more outer and inner piezoelectric actuators The method further comprises applying a second potential difference (i.e., voltage) between one or more pairs of the outer drive electrodes. In some cases, the method may include applying a voltage to the outer piezoelectric body to cause deflection of the outer piezoelectric body or bodies. The method includes the steps of applying a first potential difference and a second potential difference simultaneously (i.e., at the same time). A drive circuit typically applies the first potential difference and the second potential difference.

[0160] The first potential difference and the second potential difference may have a similar (e.g., the same) magnitude. The first potential difference and the second potential difference may have opposite polarities. Application of the first and second potential differences typically causes the inner and outer piezoelectric bodies to rotate in opposite directions. It will be a pain.

[0161] The method includes first actuating an inner actuator mechanism and an outer actuator mechanism. A step of bending at least a portion of the nozzle portion of the nozzle forming layer in a first direction. and secondly, actuating the inner actuator mechanism and the outer actuator mechanism to For at least a part of the nozzle portion of the nozzle forming layer in a second direction opposite to the first direction, and causing the nozzle-forming layer to bend in the first direction. Typically, the fluid is drawn into the fluid chamber and the nozzle forming layer is then slid in the second direction. The deflection typically expels fluid from the fluid chamber through a fluid chamber outlet. The nozzle-forming layer typically deflects in the first direction before deflecting in the second direction. In essence, the nozzle section travels a greater distance during discharge, creating a greater impact on the fluid. It is also possible to exert a strong ejection force.

[0162] Optional or preferred features of any one aspect of the invention may be used in conjunction with any other aspect of the invention. These may be optional or preferred features.

[0163] Example embodiments of the invention will now be described with reference to the following drawings: [Brief description of the drawings]

[0164] [Figure 1] FIG. 1 is a diagram of a monolithic fluid droplet emitter device including integrated fluidics, electronics, nozzles and actuators according to a first embodiment. [Diagram 2] 2 is a cross-sectional view of the monolithic drop emitter device taken along line F2 shown in FIG. 1. [Diagram 3] 2 is a top view of a nozzle featuring the monolithic drop emitter shown in FIG. 1 with the protective coating removed. FIG. [Figure 4(a)-(b)]2 is a schematic diagram of an embodiment of a drive pulse for the drop emitter device of FIG. 1. [Diagram 5] 2 is a schematic diagram of a manufacturing process flow for producing the drop emitter device of FIG. 1. [Figure 6] 11 is a cross-sectional view showing an alternative implementation of an electrode structure according to a second example embodiment of the present invention. FIG. [Figure 7] 7 is a schematic diagram illustrating an alternative drive pulse implementation for the drop emitter device of FIG. 6. [Figure 8] FIG. 13 is a schematic diagram showing a cross-section of an alternative implementation of a nozzle structure in accordance with a third example embodiment of the present invention. [Figure 9] 11 is a cross-sectional view of an alternative implementation of a bond pad structure in accordance with a fourth example embodiment of the present invention. [Figure 10] FIG. 10 is a cross-sectional view through a nozzle structure of any of the drop emitter devices of FIG. 1, FIG. 6, FIG. 8 or FIG. 9 during operation. [Figure 11] 13A-13D provide both cross-sectional and plan views illustrating an alternative monolithic drop emitter having only an inner actuator mechanism in accordance with a fifth example embodiment of the present invention. [Figure 12] 12 is a cross-sectional view through a nozzle structure of the drop emitter device of FIG. 11 during operation. [Figure 13] 13A-13D provide both cross-sectional and plan views illustrating an alternative monolithic drop emitter having only an outer actuator mechanism in accordance with a sixth example embodiment of the present invention. [Figure 14] 14 is a cross-sectional view through a nozzle structure of the drop emitter device of FIG. 13 during operation. [Figure 15] 1 is a plot showing the volume swept by a drop emitter device diaphragm as a function of the position of the actuator mechanism. [Figure 16] 1A and 1B show in 3D the shape taken by the diaphragm of the drop emitter device according to FIGS. 1, 6, 8, 9, 11 and 13 when actuated. [Figure 17] 1 is a plot showing droplet emitter diaphragm deflection for four different actuation embodiments. [Figure 18]11 is a plot showing deflection of a drop emitter diaphragm for two different actuator configurations as a function of the position of the actuator mechanism on the diaphragm. [Figure 19] Not stated in the original text. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0165] First embodiment The first embodiment will be described with reference to FIGS. 1 to 5, 10 and 11. FIG.

[0166] FIG. 1 shows an integrated fluidic device, electronic circuitry, nozzle and actuator according to a first embodiment of the present invention. FIG. 2 shows a monolithic fluid droplet emitter device 1 including an actuator. FIG. 2 is a cross-sectional view of the monolithic drop emitter device 1 along line F2.

[0167] As shown in FIGS. 1 and 2, the fluid droplet emitter device includes a substrate 100, a fluid inlet channel, and 1, an electronic circuit 200, an interconnect layer 300 with wiring, and an inner piezoelectric actuator 4 00, outer piezoelectric actuator 450, nozzle plate 500, protective front surface 600, nozzle 601 and bond pad 700. FIG. Region 102 and nozzle region 103 are shown.

[0168] The substrate 100 is typically between 20 and 1000 micrometers thick. An interconnect layer 300, an inner piezoelectric actuator 400, an outer piezoelectric actuator 450, Plate 500 and protective front surface 600 are typically 0.5 to 5 micrometers in thickness. The nozzle 601 is typically between 3 and 50 micrometers in diameter. The fluid inlet channel 103 has a characteristic dimension of 50 to 800 micrometers. .

[0169] The monolithic chip shown in FIG. 1 has four rows of nozzles. Each row is aligned with its neighbors in an alternating pattern. Any number of nozzle rows are possible in different configurations. The nozzle arrangement above is determined by the target print density (i.e., dots per inch (dpi) dots per inch), target firing frequency (dots per inch), target firing frequency (dots per inch) quency and / or target print speed. A wide range of different nozzle configurations are possible that meet the requirements. Different printhead nozzle configurations By arranging the individual nozzles and the drive electronics 201 and 202 specific to the nozzles, This is what happens.

[0170] The substrate 100 is formed from a silicon wafer and includes a support 102, a fluid inlet channel 101, and a and an electronic circuit 200.

[0171] The fluid inlet channel 101 is arranged on a base such that it opens to a fluid inlet 103 on one side. At the other end, the nozzle plate 500 and the nozzle The walls of the fluid inlet channel 101 are terminated by a substrate 100 and an interconnect 601. The fluid inlet channel 101 has a substantially cylindrical shape. The nozzle plate has a substantially circular cross section in the plane of the substrate. The corners of the fluid inlet channel 101 at the interface and fluid inlet interface are designed to minimize stress concentrations. It is rounded like a

[0172] The electronic circuit 200 is formed on the surface of the substrate 100 opposite the surface including the fluid inlet 103. The electronic circuit 200 may include digital and / or analog circuitry. The electronic circuit portions 201 and 202 are formed by wirings 301 and 302 that pass through an interconnect layer 300. , which directly connects the inner piezoelectric actuator 400 and the outer piezoelectric actuator 450 and positioned close to the actuators 400 and 450 to optimize application of the drive waveforms. The electrode actuator wiring interconnects 301 and 302 are arranged as a continuous single structure. The drive electronics may be a single crystal structure or may be constructed from multiple layers of wiring. The input may be configured to apply a set or shaped voltage to the input for a set period of time.

[0173] The electronic circuitry portion 203 is associated with the overall operation of the entire monolithic droplet emitter device. However, it can be located separately from the actuator driving circuits 201 and 202. Circuits 203 related to the general operation of the chip include data routing, authentication, chip monitoring (e.g., For example, chip temperature monitoring, age management, yield information processing and / or defective nozzle monitoring, etc. The circuitry 203 can perform a wide range of functions. The chip driving circuit is connected to the head 700 and predetermined electrode driving circuits 201 and 202. Child device 203 performs data caching, data routing, bus management, general purpose logic, They may perform different functions such as synchronization, security, authentication, power routing and / or input / output. The chip may include analog and / or digital circuits configured to drive the chip. The child device 203 may include circuits such as timing circuits, interface circuits, sensors, and / or clocks. It can have parts.

[0174] Located in different sections of the chip, for example between rows of nozzles or around the periphery of the chip There may be several general purpose drive electronics areas.

[0175] The electronic driver circuitry includes 200 CMOS driver circuits.

[0176] The interconnect layer 300 is formed directly on the electronic circuit 200 and the substrate 100 and is an electrical insulator. The wiring in the interconnect layer 300 connects the chip electronics 203 to the bond pads. The interconnection is connected to both the pad 700 and the actuator electrode drive circuits 201 and 202. The continuous layer 300 is routed between the nozzles, around the periphery of the chip and / or over the drive electronics. The interconnect layer 300 typically includes power and data routing wiring. comprises multiple layers having different wiring paths.

[0177] The nozzle plate 500 is formed on the interconnect layer 300. 00 is made of either a single material or a laminate of multiple materials. The port 500 is continuous across the front surface of the chip and is connected to the lower interconnect layer 300 and the upper It has electrical openings for wiring between the actuator electrodes 401 .

[0178] The nozzle plate 500 is CMOS electronically controlled with respect to deposition temperature, composition, and chemical processing steps. It is made of one or more materials that must be manufacturable with the drive circuit 200. The nozzle plate material is also chemically stable and resistant to the fluids being ejected. The nozzle plate material must also be impermeable to the piezoelectric actuators. For example, the Young's modulus of a suitable material is 70 GPa to However, the Young's modulus varies by 50 GPa for the nozzle plate. The thickness of the nozzle plate can be adjusted by changing the thickness of the nozzle plate. , silicon dioxide (SiO 2 ), silicon nitride (Si 3 N 4 ), silicon carbide (SiC) and silicon oxynitride (SiO x N y ) (including, for example, combinations and / or laminates thereof) or Includes multiple species.

[0179] Each outer piezoelectric actuator 450 includes a first electrode 451, a piezoelectric layer 452 and a second electrode 45 The first electrode 451 is attached to the nozzle plate 500. The piezoelectric layer 452 is attached to the first electrode 451. The second electrode 403 is attached to the first electrode 451. The first electrode 451 is attached to the surface of the piezoelectric layer opposite the mounting surface. The second electrode 453 is electrically connected to the wiring connection portion 301 at the interconnection layer 451. The first electrode 451 and the second electrode 452 are electrically connected to the wiring connection portion 302 in the wiring connection portion 300. The poles 453 are electrically isolated from each other.

[0180] Each inner piezoelectric actuator 400 includes a first electrode 401, a piezoelectric layer 402 and a second electrode 40 The first electrode 401 is attached to a nozzle plate 500. The piezoelectric layer 402 is attached to the first electrode 401. The second electrode 403 is attached to the first electrode 401. The first electrode 401 is attached to the surface of the piezoelectric layer opposite the surface to which it is attached. The second electrode 403 is electrically connected to the second electrode 453 of the outer piezoelectric actuator. The first electrode 451 of the inner piezoelectric actuator is electrically connected to the first electrode 452 of the inner piezoelectric actuator. The electrode 401 and the second electrode 403 are electrically insulated from each other.

[0181] The electrode material is conductive and is typically titanium (Ti), aluminum (Al), Tungsten aluminide (TiAL), tungsten (W) or platinum (Pt), or These materials are made of metals or intermetallic compounds such as alloys of these metals. It can be manufactured with CMOS drive circuitry and piezoelectric layers (in terms of process and chemical process compatibility).

[0182] Piezoelectric layers 402 and 452 are selected for compatibility with CMOS and interconnect circuit fabrication. CMOS drive circuits are typically manufactured from materials selected for their maximum operating temperature of approximately 450°C. However, for high yield manufacturing, a much lower peak is required. The manufacturing temperature of the CMOS drive electronics is typically around 300°C. Deposition methods that expose the material to multiple temperatures over a period of time can degrade performance and typically It affects dopant mobility and degradation of wiring in the interconnect layers. Temperature limitations cause piezoelectric The deposition method of the layers is limited. Suitable piezoelectric materials include aluminum nitride (AlN), Scandium aluminum nitride compounds (especially scandium aluminum nitride (ScAlN)) and oxides Zinc (ZnO) is one of the materials that are compatible with CMOS electronic circuits. is selected to optimize the piezoelectric properties. For example, in aluminum nitride compounds The concentration of any additive element (e.g., the concentration of scandium in scandium aluminum nitride) ) is typically 31 The piezoelectric constant is selected to optimize the magnitude. The higher the concentration of scandium in aluminum, the higher the 31 The value of becomes larger The mass percentage of scandium in scandium aluminum nitride is about 50%. There is a high possibility that

[0183] The piezoelectric actuator material is not continuous across the surface of the nozzle plate 500 . The piezoelectric material is located primarily on the nozzle plate, and covers the electrode opening 404 and the area around the nozzle. The aperture 405 includes a plurality of openings.

[0184] A protective front surface 600 is formed on the exterior surface of the drop emitter device 100 and covers the piezoelectric layers 402 and 403. 52, covering the electrodes 401, 403, 451 and 453 and the nozzle plate 500. The front surface has openings for the nozzles 601 and openings for the bond pads 700 . The protective front material is chemically inert and impermeable. The mechanical properties of the protective front material may be such that it is repellent to the fluid being applied. 400 and 450 and the nozzle plate 500 to minimize the effect on the extrusion action. The protective front surface material is carefully selected for example for processing temperature and chemical process compatibility. The protection circuitry is selected to be manufacturable by a CMOS compatible process flow. The front surface 600 prevents fluid contact with either the electrodes or the piezoelectric layer. Examples include polyimide, polytetrafluoroethylene (PTFE), and diamond-like carbon. (DLC) or related materials.

[0185] FIG. 3 shows a first embodiment of the device with protective coating 600 removed. FIG. 1 is a top view of a nozzle showing the features of a lithographic droplet emitter structure 1. The dashed lines indicate the piezoelectric inner actuator. The position below the fluid inlet 103 relative to the actuator 400 and the outer piezoelectric actuator 450 Indicates the location.

[0186] In use, the fluid droplet emitter device 1 can supply fluid to the fluid inlet 103. The fluid pressure is typically slightly negative at the fluid inlet 103. pressure, and the fluid inlet channel 101 is typically a capillary driven by surface tension. The fluid inlet 103 is primed or filled with fluid by the priming phenomenon. Once primed, the nozzle 601 primes to the outer surface of the protective front surface 600 by capillary action. The fluid is forced through the nozzle 601 by a combination of negative fluid pressure and the geometry of the nozzle 601. It does not move past 601 onto the outer surface of protective surface 600 .

[0187] The actuator drive circuits 201 and 202 receive a timing signal from the overall drive circuit 203. The application of voltage pulses to the driving electrodes 401, 403, 451, and 453 is controlled according to the signal. Application of electrode voltages across the piezoelectric layers 402 and 452 produces two electric fields. The electric field at 402 deforms the piezoelectric material layers 402 and 452. This deformation is due to the polarity of the material. can be either tensile or compressive depending on the orientation of the electric field with respect to the local direction of The induced strain caused by the expansion or contraction of the piezoelectric materials 402 and 452 is typically Typically, a nozzle plate 500, piezoelectric actuators 400 and 450, and a protective front layer Induce a strain gradient through the thickness of 600 and move the nozzle plate relative to the neutral position or To displace.

[0188] The piezoelectric properties of a piezoelectric material are determined in part by the transverse piezoelectric constant d 31 It can be characterized by: d 31 is a method for determining whether an electric field is applied across a piezoelectric material in a first direction, the electric field being perpendicular to the first direction. The piezoelectric coefficient tensor, which relates the strain induced in the piezoelectric material along a perpendicular second direction, The piezoelectric actuators 400 and 450 shown are specific components of an applied voltage. The field is designed to induce strain in the material layer in a direction perpendicular to the direction in which the electric field is applied. Therefore, d 31 It is characterized by a constant.

[0189] The uniform thickness and composition of both the piezoelectric material layers 402 and 452, and the electrodes 403 and The electrical cross-connections between electrodes 401 and 451 and electrodes 401 and 453 allow for the application of a constant voltage or a voltage pulse. The application applies a first potential difference across the inner actuator layer and a second potential difference across the outer actuator layer. A second potential difference is applied across the data layer, the first potential difference and the second potential difference being In other words, across the inner actuator piezoelectric layer Electric field E 1 is induced, causing an electric field E across the outer actuator piezoelectric layer. 2 is caused, E 1 and E 2 are equal in magnitude but act in opposite directions. E 1 and E 2 acts in the opposite direction Therefore, the inner and outer actuator layers deform in opposite directions. 1 Reach B 2 Depending on the polarity of the electric field, the displacement X of the nozzle plate 500 can be changed from a neutral position (i.e., When no voltage is applied, the voltage is either positive or negative. At the bottom of the figure, the positive displacement of the nozzle plate is shown.

[0190] Application of a pulsed electric field can result in vibration of the nozzle plate 500 . This vibration of the nozzle plate typically causes the fluid inlet 1 below the nozzle plate 500 to Pressure is induced in the nozzle plate 603, and droplets are ejected from the nozzle 601. The number and amplitude of the movements are mainly determined by the nozzle plate 500, the piezoelectric actuators 400 and 450, The mass and stiffness of the protective layer 600, the fluid properties (e.g., fluid density, fluid viscosity (Newtonian viscosity) viscosity (either Newtonian or non-Newtonian viscosity) and surface tension), nozzle and fluid inlet geometry is a function of the shape, configuration of both drive pulses.

[0191] FIG. 4(a) and FIG. 4(b) show two implementations of the drive pulse. The voltage pulses across the actuator electrodes 401 and 403 are of equal magnitude but opposite polarity. A pair of voltage pulses are applied simultaneously across the outer actuator electrodes 451 and 453. It will be understood that this is the case.

[0192] In a first embodiment, as shown in the top part of FIG. 4(a), a steady electric field or DC Application of an electric field induces strains in the piezoelectric layers 402 and 452 and a flow in the direction away from the fluid inlet. This results in a steady deflection of the nozzle plate. The fluid pressure below the nozzle plate is The strain energy is the same as the nozzle plate 500, the piezoelectric actuator The data 400 and 450 and the protective layer 600 are stored.

[0193] Then, as shown in the lower part of Figure 4(a), the electric field is removed and a reverse electric field pulse is applied. This allows the release of stored strain energy and the piezoelectric material to move in the opposite direction. The nozzle plate moves towards the fluid inlet and This results in positive pressure in the fluid inlet and nozzle area and droplet ejection from nozzle 601. The reverse electric field pulse is applied immediately after removal of the DC field or after a short delay. The voltage can be applied for a period of time.

[0194] Final removal of the electric field across the piezoelectric material induces a strain in the nozzle plate 500. The lever returns to the neutral position without any tension.

[0195] Application of electric fields of opposite polarity across the inner and outer actuators The nozzle plate deforms to the shape shown in Figure 10. The nozzle plate is opposed to the nozzle plate curvature in the area of ​​the outer actuator. This particular shape allows the nozzle to bend in the direction of the arrow, resulting in an S-shaped cross section. The plate is driven by only one actuator, which causes bending in only one direction. The displacement of the nozzle portion of the nozzle plate from the neutral position compared to the displacement achievable when The maximum displacement is significantly increased. Increase the maximum displacement of the nozzle plate away from the neutral position. By applying This allows the force that can be generated to be low. Low d, which is generally considered unsuitable for use in inkjet printers due to 31 This allows the use of piezoelectric materials with low d 31 The material is usually heated at a lower temperature. This allows for faster processing and closer integration of the drop emitter with the CMOS components. The higher dispensing force that can be achieved also allows for a reduction in the overall dispenser size. This allows for increased printhead nozzle density.

[0196] In the second embodiment, the pulsed electric field configuration shown in FIG. 4(b) is used together with the pulsed electric field configuration shown in FIG. This is a DC field configuration that, over a longer period of time, eliminates any applied distortion effects. The advantage of this is that it minimizes the amount of electric field generated by the double pulses. This allows for further advantages of the laser-based approach. The application of the first pulse is shown in the upper part of Figure 4(b). As shown, a vibration is induced that accompanies an initial movement of the nozzle plate away from the fluid inlet. The vibration of the nozzle plate creates a negative fluid pressure under the nozzle plate, which in turn drives a positive A flavor fluid flow is created, which can further increase the fluid discharge flow through the nozzle.

[0197] FIG. 5 is a schematic diagram showing a manufacturing process flow for a droplet emitter device. As shown, the first fabrication step is to deposit the drive circuitry and interconnects on the surface of a silicon wafer substrate. Layer 300 is for example to create CMOS drive circuitry and interconnects. The drive circuitry is fabricated using standard processes, such as ion implantation onto a p-type or n-type substrate, and This is followed by standard CMOS fabrication processes (e.g., ion implantation, chemical vapor deposition (C VD), Physical Vapor Deposition (PVD), Etching, Chemical Mechanical Planarization (CMP) and / or Electrochemical The interconnect layers are formed by deposition of metal oxide layers (SiO 2 ) on the substrate.

[0198] Subsequent fabrication steps define the features and structure of the monolithic droplet emitter device. Subsequent steps are performed without damaging the structures formed in the previous steps. The critical manufacturing parameter is the peak processing temperature. Problems with MOS processing include dopant mobility and degradation of interconnect wiring mechanisms. CMOS electronics are known to withstand temperatures of 450°C. However, for high yields, much lower temperatures (i.e., less than 300°C) are desirable. It is nice.

[0199] As shown in FIG. 5(b), a nozzle plate 500, piezoelectric actuators 400 and 45 0, a protective layer 600 as well as bond pads 700 are formed over the interconnect layer.

[0200] The nozzle plate 500 is deposited using a CVD or PVD process.

[0201] The formation of the CMOS compatible piezoelectric material 402 and 452 is a key driving force for the actuator. Table 1 shows some common piezoelectric materials and their The relevant manufacturing method is a typical 31 The highest d 31 Materials with value It turns out that the material is not compatible with the fabrication of monolithic CMOS structures. The material has low d 31 value and therefore has a much lower extrusion capacity.

[0202] As can be seen from the table, lead zirconate titanate (PZT) is a material that can be deposited by PVD (sputtering) can be deposited at low temperatures using a GaN-based GaN- ... PZT also requires post-processing annealing at temperatures above that which is possible with the sol-gel process. It is also possible to deposit the material by high-temperature annealing, which again exceeds the limits of CMOS. Annealing is required. PZT also deposits very slowly, making it commercially unviable. PZT also contains lead, which is environmentally undesirable.

[0203] ZnO, AlN and AlN compounds (ScAlN, etc.) materials require post-treatment such as annealing. It can be deposited using low temperature PVD (e.g. sputtering) processes that do not require These materials also do not require poling, which is a step that is not possible with PZT. In this case, the material must have a very strong electric field that orients all electric dipoles in the direction of the electric field. Exposed to the world.

[0204] Therefore, ZnO, AlN and AlN compound (e.g., ScAlN) materials are monolithic. It is a commercially viable material for the fabrication of lithographic drop emitter devices. et al., d of these materials 31 The value of is significantly lower than that of PZT. The specific configuration of the nozzle (i.e., the actuatable nozzle plate) and the resulting improved actuation efficiency The use of two pairs of control electrodes allows for the lower d 31 Cancel the values.

[0205] Actuator electrode materials are CMOS compatible, such as PVD (including low temperature sputtering) The electrode is deposited using a process. Typical electrode materials are titanium (Ti), platinum (P t), aluminum (Al), tungsten (W), molybdenum (Mo) or their alloys The electrodes can be patterned by standard patterning and etching methods. It is determined.

[0206] The protective material is applied by a spin-on and cure process (suitable for polyimide or other polymeric materials). It is deposited and patterned using the pin on and cure method. Some materials, such as PTFE, require more specific deposition and patterning techniques. may be required.

[0207] The bond pads are deposited using methods such as CVD or PVD (e.g., sputtering). Allow to deposit.

[0208] As shown in Figure 5(c), the fluid inlet channel is a deep-drilled reactive ion emitter with a high aspect ratio. The fluid inlets are defined using a wafer front / backside aligner. The nozzle structure is aligned using a tool. The wafer can then be mounted onto the handle wafer.

[0209] DRIE techniques can also be used to singulate the dies, but other methods such as a wafer saw are also used. The above technique can also be used.

[0210] Second embodiment 6 is a cross-sectional view of an alternative embodiment of an electrode structure. In this embodiment, electrode 403 and 453 are connected to the ground line 204, not the drive circuit, by the wiring 302. The ground line 204 is located in the interconnect layer 300 and is connected to the driving circuit area 203. , or directly to the grounded bond pad 700.

[0211] Third embodiment FIG. 7 is a schematic diagram illustrating an alternative drive pulse embodiment compatible with this drop emitter device. The voltage pulse shown in FIG. 7 is applied to only one electrode of each electrode pair, for example, 401 and and 453, so that the electric field through the piezoelectric actuators 400 and 450 is This electric field causes the nozzle plate 500 to be displaced generally downward. A ground voltage is applied to electrodes 401 and 453. It is also possible to configure the device in this way.

[0212] Fourth embodiment FIG. 8 is a schematic diagram showing a cross section of an alternative embodiment of a nozzle structure, proximate the fluid inlet 101. 5 shows an extension of the interconnect layer 304 attached to the nozzle plate layer 500. The extension 304 may include only dielectric material, without any wiring. In this example, the device does not have a nozzle plate layer and is attached to a piezoelectric actuator. The semiconductor device has only interconnect layers.

[0213] Fifth embodiment FIG. 9 is a cross-sectional view of an alternative embodiment of a bond pad structure. 701. This geometry allows for easy access for external wiring mechanisms. This improves performance and reduces the overall height of the wire bonds above the chip height.

[0214] Sixth and Seventh Embodiments FIG. 11 shows a nozzle that includes only an inner piezoelectric actuator 400 adjacent to a fluid outlet 601. FIG. 1 is a schematic diagram showing a cross-sectional view and a plan view of an alternative embodiment of a structure in which a piezoelectric material The material extends only between electrodes 401 and 402 and does not extend over the remainder of the nozzle plate layer 500. does not extend beyond the upper electrode (i.e., where the outer piezoelectric actuator is expected to be located). (not extending into region 450 where the

[0215] Application of an electric field across the inner actuator causes the nozzle plate to assume the shape shown in FIG. Actuation of the inner actuator causes the inner portion of the nozzle plate to deform in a first direction. In response, the outer portion of the nozzle plate curves in the opposite direction, resulting in an S-shape. This particular shape allows the nozzle plate to bend in only one direction. There is only one actuator that extends across most of the nozzle plate. The displacement of the nozzle part of the nozzle plate from the neutral position compared to the displacement achievable if the nozzle part The maximum displacement of the minute increases significantly.

[0216] Additionally, FIG. 13 only includes the outer piezoelectric actuator 450 adjacent to the fluid outlet 601. FIG. 1 is a schematic diagram showing cross-sectional and plan views of an alternative embodiment of a nozzle structure including a , the piezoelectric material extends only between electrodes 401 and 402 and not the remainder of nozzle plate layer 500. does not extend beyond the electrode on the portion of the piezoelectric actuator (i.e., the area where the inner piezoelectric actuator is located). 400 into which it may be expected that the

[0217] Application of an electric field across the outer actuator causes the nozzle plate to assume the shape shown in FIG. Actuation of the outer actuator causes the outer portion of the nozzle plate to deform in a first direction. In response, the inner part of the nozzle plate curves in the opposite direction, resulting in an S-shape. This particular shape allows the nozzle plate to bend in only one direction. There is only one actuator that extends across most of the nozzle plate. The displacement of the nozzle part of the nozzle plate from the neutral position compared to the displacement achievable if the nozzle part The maximum displacement of the minute increases significantly.

[0218] FIG. 15 shows the radial distribution of the fluid flow from a single annular actuator symmetrically positioned about the fluid outlet. This shows the volume swept by the nozzle plate during actuation as a function of its axial position. In this case, The layer of piezoelectric material extends across the nozzle plate and the actuator position is a first The nozzle plate is defined by the positions of the actuator electrodes and the second actuator electrodes. The port has an outer radius of 125 microns. From this figure, the maximum swept volume (and therefore Fluid ejection) close to the outer edge of the nozzle plate (105 microns from the center) It can be seen that this is achievable for actuators located at the outer edge. The 3D shape that the nozzle plate takes upon actuation of a single closely spaced annular actuator The inner portion of the nozzle plate is curved in the opposite direction from the outer portion of the nozzle plate. It can be seen that...

[0219] FIG. 17 illustrates an embodiment with both an inner and an outer piezoelectric actuator. In this state, the nozzle pump is driven from a neutral position (i.e., before the actuation of all actuators). Shows how the rate deflection varies with radial position across the nozzle plate. This diagram shows "reverse polarity" (both the inner and outer annular actuators). are provided, each of which is simultaneously actuated by an electric field having an opposite polarity), "Both an inner annular actuator and an outer annular actuator are provided, each of which has the same simultaneously actuated by electric fields of the same polarity), “inner only” (inner annular actuator and an outer annular actuator are provided, but only the inner actuator is actuated. ), and "external only" (both the inner and outer annular actuators are installed) The data set for the 1st stage is shown in Fig. 1. In the embodiment shown, electric fields having opposite polarities are applied to the inner and outer actuators. The maximum deflection is achieved when the applied voltage is

[0220] FIG. 18 also includes only a single piezoelectric actuator, and the piezoelectric material is For embodiments in which the nozzle plate does not extend beyond the nozzle head, the deflection of the nozzle plate from the neutral position is FIG. 14 shows how the radial position across the nozzle plate varies with the In this embodiment, the maximum deflection is achieved when the inner actuator is provided. The absence of piezoelectric material in the eta-free regions increases flexibility and therefore the inner Compared to dispensers incorporating both a piezoelectric actuator and an external piezoelectric actuator, and incorporates a single annular piezoelectric actuator (either internal or external). It is possible that greater deflections can be achieved with the dispenser.

[0221] Further variations and modifications can be made within the scope of the invention disclosed herein.

[0222] The device may be formed on a silicon wafer substrate. Alternatively, the substrate may be a silicon Silicon-on-insulator wafer or I It may include a II-V semiconductor wafer.

[0223] The fluid inlet channel is substantially cylindrical and therefore substantially Alternatively, the fluid inlet channel may have a multi-sided, regular cross section. A variety of other cross sections may be used, including regular or irregular shapes. The shape of the nozzles is typically determined by the layout of the nozzles, the location of the drive electronics, and the interconnect layer 30. 0, and other aspects of the monolithic chip design.

[0224] Cross-sectional shape minimizes printhead tip width without introducing a failure mechanism The failure mechanism may be structural (e.g. For example, too many fluid inlets may reduce the robustness of the chip), or may be operational (e.g., the interconnect wires may be insufficient to carry adequate current). The reduction in printhead width means that it can be fabricated on a single wafer. This is desirable because it increases the number of chips that can be

[0225] Further variations and modifications can be made within the scope of the invention disclosed herein.

Claims

1. 1. A droplet ejector for a printhead, comprising: a substrate having a mounting surface and an opposing nozzle surface; a nozzle forming layer formed on at least a portion of the nozzle surface of the substrate; a fluid chamber defined at least in part by the substrate and at least in part by the nozzle forming layer, the fluid chamber having a fluid chamber outlet defined at least in part by a nozzle portion of the nozzle forming layer, the nozzle portion having an inner portion located proximate to the fluid chamber outlet and an outer portion located proximate to a periphery of the nozzle portion; an inner actuator mechanism formed in the inner portion of the nozzle portion of the nozzle forming layer; Equipped with A drop emitter, wherein the inner actuator mechanism comprises one or more inner piezoelectric actuators, at least one of the one or more inner piezoelectric actuators comprising an inner piezoelectric body disposed between a pair of inner drive electrodes.

2. The drop emitter of claim 1 , wherein the inner actuator mechanism and the nozzle portion of the nozzle-forming layer are configured such that upon actuation, the inner portion of the nozzle portion bends in a first direction.

3. 3. The drop emitter of claim 1 or 2, wherein the outer portion of the nozzle portion of the nozzle forming layer at least partially surrounds the inner portion of the nozzle portion of the nozzle forming layer.

4. A drop emitter according to any preceding claim, wherein the internal actuator mechanism at least partially surrounds the fluid chamber outlet.

5. A drop emitter according to any preceding claim, wherein the inner actuator mechanism is substantially annular.

6. The drop emitter of any preceding claim, further comprising at least one electronic component integrated with the substrate.

7. The drop emitter of claim 1 , wherein the inner actuator mechanism comprises a single inner piezoelectric actuator that is substantially annular.

8. A droplet emitter as described in any one of claims 1 to 7, comprising an outer actuator mechanism comprising one or more outer piezoelectric actuators, at least one of the one or more outer piezoelectric actuators comprising an outer piezoelectric body disposed between a pair of outer drive electrodes.

9. The drop emitter of claim 8 , wherein the outer actuator mechanism comprises a single, substantially annular, outer piezoelectric actuator.

10. The drop emitter of claim 9 , wherein the single outer piezoelectric actuator surrounds a single inner piezoelectric actuator.

11. A droplet emitter as described in any one of claims 8 to 10, wherein both the inner drive electrode pair and the outer drive electrode pair are electrically connected to a drive circuit which, when connected to a power source in use, is configured to apply a first potential difference between the inner electrode pair to cause deflection of the inner piezoelectric body in a first direction and to apply a second potential difference between the outer electrode pair to cause deflection of the outer piezoelectric body in a second direction opposite to the first direction.

12. A drop emitter according to any one of claims 8 to 11, wherein the inner piezoelectric body or bodies and the outer piezoelectric body or bodies comprise one or more piezoelectric materials that are processable at temperatures below 450°C.

13. A drop emitter according to any one of claims 8 to 12, wherein the inner piezoelectric body or bodies and the outer piezoelectric body or bodies comprise one or more piezoelectric materials that can be deposited at a temperature of less than 450°C.

14. 14. A drop emitter according to claim 12 or 13, wherein the one or more piezoelectric materials are PVD deposited piezoelectric materials.

15. A drop emitter according to any one of claims 12 to 14, wherein the one or more piezoelectric materials comprise aluminum nitride and / or zinc oxide.

16. 16. The drop emitter of claim 15, wherein the aluminum nitride further comprises one or more of the following elements: scandium, yttrium, titanium, magnesium, hafnium, zirconium, tin, chromium, and boron.

17. 17. A drop emitter as described in any one of claims 12 to 16, wherein the one or more piezoelectric materials comprise a ceramic material comprising aluminum and nitrogen, and optionally one or more elements selected from scandium, yttrium, titanium, magnesium, hafnium, zirconium, tin, chromium, and boron.

18. A drop emitter according to any one of claims 12 to 17, wherein the one or more piezoelectric materials are non-ferroelectric piezoelectric materials.

19. The one or more inner piezoelectric bodies have a magnitude of less than 20 pC / N. 31 A drop emitter according to any preceding claim, having a piezoelectric constant.

20. The drop emitter of any preceding claim, further comprising at least one electronic component integrated with the substrate.

21. A drop emitter according to any preceding claim, wherein the mounting surface of the substrate comprises a fluid inlet aperture in fluid communication with the fluid chamber.

22. A drop emitter according to any preceding claim, wherein the fluid chamber is substantially cylindrical and the nozzle portion of the nozzle forming layer is substantially annular.

23. The drop emitter of any preceding claim, further comprising a protective layer covering the inner actuator mechanism and the nozzle forming layer.

24. A printhead comprising a plurality of drop ejectors according to any preceding claim.

25. The printhead of claim 24 , wherein the multiple drop ejectors share a common substrate.

26. A printer comprising one or more printheads according to claim 24 or 25.

27. 21. A method of operating a droplet emitter as claimed in any one of claims 1 to 20, comprising the step of actuating the inner actuator mechanism, thereby causing displacement of at least a portion of the nozzle portion of the nozzle forming layer and resulting ejection of fluid from the fluid chamber through the fluid chamber outlet.

28. 28. The method of claim 27, wherein the droplet emitter comprises both an inner actuator mechanism and an outer actuator mechanism, the method including the step of actuating both the inner actuator mechanism and the outer actuator mechanism, thereby causing displacement of at least a portion of the nozzle portion of the nozzle forming layer and resulting ejection of fluid from the fluid chamber through the fluid chamber outlet.

29. 30. The method of claim 28, wherein the steps of actuating the inner actuator mechanism and actuating the outer actuator mechanism occur simultaneously.

30. The droplet ejector comprising an outer actuator mechanism having one or more outer piezoelectric actuators, at least one of the one or more outer piezoelectric actuators comprising an outer piezoelectric body disposed between a pair of outer drive electrodes; 30. The method of claim 28 or 29, wherein actuating the inner actuator mechanism comprises applying a first potential difference between the pair of inner drive electrodes to cause deflection of the inner piezoelectric body, and actuating the outer actuator mechanism comprises applying a second potential difference between the pair of outer drive electrodes to cause deflection of the outer piezoelectric body.

31. 31. The method of claim 30, wherein the first and second potential differences have opposite polarities such that the inner and outer piezoelectric bodies deflect in opposite directions.

32. 32. The method of claim 30 or 31, wherein the first potential difference and the second potential difference are applied simultaneously.

Images