Systems and methods for sealing microvalves used in a jetting assembly

Abstract

A microvalve includes an orifice plate having a first surface, a second surface, and an orifice extending from the first surface to the second surface. An actuation beam is disposed in spaced relation to the orifice plate. The actuation beam includes a base portion and a cantilever portion. The base portion is separated from the orifice plate by a predetermined distance. The cantilever portion extends from the base portion such that an overlapping portion of the cantilever portion overlaps the orifice. The actuation beam is movable between a closed position and an open position. The microvalve further includes a seal structure including a sealing member disposed at the overlapping portion of the cantilever portion. When the actuation beam is in the closed position, the cantilever portion is positioned such that the seal structure seals the orifice to close the microvalve.

Description

[0001] This application is a divisional application of patent application CN201980045536.6 filed on May 9, 2019, entitled "System and method for a micro valve used in a sealing injection assembly".

[0002] Cross-reference to related applications

[0003] This application claims priority and benefit to U.S. Provisional Application No. 62 / 670,280, filed May 11, 2018, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0004] This disclosure generally relates to the field of miniature valves manufactured using microelectromechanical systems (MEMS) technology. More specifically, this disclosure relates to injection assemblies including miniature valves for industrial marking and coding. Background Technology

[0005] Traditional printing technologies have several drawbacks. For example, continuous inkjet printers have certain inherent defects that are difficult to eliminate. For instance, the process of generating droplets from the ink supply unit can cause ink to drip in undesirable directions (e.g., away from the target), leading to maintenance needs. Additionally, replenishment fluid is lost over time due to evaporation, requiring constant replenishment. Other maintenance costs also exist, such as repairing perforated plates due to deterioration. Summary of the Invention

[0006] In some embodiments, the miniature valve includes an orifice plate having a first surface and a second surface. The orifice plate includes an orifice extending from the first surface to the second surface. The miniature valve also includes an actuating beam disposed at a spaced-apartment from the orifice plate. The actuating beam includes a base portion and a cantilever portion. The base portion is separated from the orifice plate by a predetermined distance. The cantilever portion extends from the base portion such that an overlapping portion of the cantilever portion overlaps with the orifice. The actuating beam is movable between a closed position and an open position. The miniature valve also includes a sealing structure comprising a sealing member disposed at the overlapping portion of the cantilever portion. When the actuating beam is in the closed position, the cantilever portion is positioned such that the sealing structure seals the orifice to close the miniature valve.

[0007] Another embodiment relates to a method of constructing a micro-valve for a microelectromechanical system (MEMS). The method includes providing an orifice plate including an orifice. The method also includes providing an actuating beam having a spacer member and a sealing member attached thereto. The method further includes forming a portion of a sealing structure on the orifice plate or the sealing member. The method also includes, after forming this portion of the sealing structure, attaching the actuating beam to the orifice plate such that the sealing member is aligned with the orifice plate, and in a closed position of the actuating beam, the sealing structure forms a seal between the orifice and the volume adjacent to the actuating beam.

[0008] Another embodiment relates to an injection assembly. The injection assembly includes a valve body comprising an orifice plate having a plurality of orifices extending therethrough. The injection assembly also includes a plurality of microvalves. Each of the plurality of microvalves includes a spacer member disposed on the orifice plate and displaced from a corresponding orifice. Each of the plurality of microvalves also includes an actuation beam comprising a base portion disposed on the spacer member and a cantilever portion extending from the base portion toward a corresponding orifice, such that an overlapping portion of the cantilever portion overlaps with the corresponding orifice. The actuation beam is configured to move between a closed position and an open position, in which the cantilever portion bends toward the orifice, and in the open position, the cantilever portion bends away from the orifice. Each of the plurality of microvalves also includes a sealing structure comprising a sealing member attached to the overlapping portion and extending toward the corresponding orifice. The injection assembly also includes a fluid manifold coupled to each of the plurality of microvalves to define a fluid reservoir for each microvalve.

[0009] Some embodiments involve a miniature valve comprising an orifice plate including a first surface and a second surface. The orifice plate includes an orifice extending from the first surface to the second surface. An actuation beam is disposed spaced apart from the orifice plate. The actuation beam includes a base portion and a cantilever portion, the base portion being separated from the orifice plate by a predetermined distance, and the cantilever portion extending from the base portion toward the orifice such that the overlapping portion of the cantilever portion overlaps with the orifice. The actuation beam is movable between a closed position and an open position. A sealing structure is disposed on the actuation beam. The sealing structure includes a sealing member disposed at the overlapping portion of the cantilever portion. A stop is disposed on the surface of the sealing member. The stop includes a first portion attached to the surface of the sealing member and a second portion adjacent to the orifice plate disposed on the first portion. The second portion has a larger cross-sectional area than the first portion. When the actuation beam is in the closed position, the cantilever portion is positioned such that the stop seals the orifice to close the miniature valve.

[0010] Other embodiments involve a miniature valve including an orifice plate comprising a first surface and a second surface. The orifice plate includes an orifice extending from the first surface to the second surface. An actuation beam is disposed spaced apart from the orifice plate. The actuation beam includes a base portion and a cantilever portion. The base portion is separated from the orifice plate by a predetermined distance. The cantilever portion extends from the base portion toward the orifice such that the overlapping portion of the cantilever portion overlaps with the orifice. The actuation beam is movable between a closed position and an open position. A sealing structure is disposed on the actuation beam. The sealing structure includes a valve seat surrounding the orifice. The valve seat defines an opening surrounding the orifice to define a fluid outlet. A sealing member is disposed at the overlapping portion of the cantilever portion. A first sealing blade extends a distance from the sealing member surface toward the orifice plate. The first sealing blade surrounds the entire periphery of the orifice. The sealing blade is configured to contact the valve seat in the closed position to seal the fluid outlet and close the miniature valve.

[0011] Other embodiments involve a miniature valve including an orifice plate comprising a first surface and a second surface. The orifice plate includes an orifice extending from the first surface to the second surface. An actuation beam is disposed spaced apart from the orifice plate. The actuation beam includes a base portion and a cantilever portion, the base portion being separated from the orifice plate by a predetermined distance, and the cantilever portion extending from the base portion toward the orifice such that an overlapping portion of the cantilever portion overlaps with the orifice. The actuation beam is movable between a closed position and an open position. A sealing structure is disposed on the actuation beam. The sealing structure includes a sealing member disposed at the overlapping portion of the cantilever portion. A narrow portion is disposed at the end of the sealing member. The narrow portion defines a sealing member surface facing the orifice. A sealing flap extends outward from the narrow portion and is configured to seal the orifice to close the miniature valve when the actuation beam is in the closed position. Attached Figure Description

[0012] This disclosure will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0013] Figure 1 This is a perspective view of a jet assembly disposed in a retainer according to an exemplary embodiment.

[0014] Figure 2 yes Figure 1 An exploded view of the injection assembly shown.

[0015] Figure 3 yes Figure 1 A schematic cross-sectional view of the injection assembly shown.

[0016] Figure 4A yes Figure 1 A plan view of the injection assembly shown; Figure 4B It is possible according to the exemplary implementation scheme Figure 1 A schematic diagram of the adhesive structure used in the spraying assembly.

[0017] Figure 5A This is a cross-sectional view of an injection assembly including a microvalve according to an exemplary embodiment.

[0018] Figure 5B This is a cross-sectional view of an injection assembly including a microvalve according to another exemplary embodiment.

[0019] Figure 6 It provides Figure 5A A cross-sectional view of a more detailed view of the injection assembly shown.

[0020] Figure 7A This is a cross-sectional view of the actuation beam of the miniature valve according to the example implementation; Figure 7B According to another exemplary implementation Figure 7A Front sectional view of the actuating beam.

[0021] Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 and Figure 13 This is a cross-sectional view of the sealing structure of a miniature valve according to various exemplary embodiments.

[0022] Figure 14 and Figure 15 This is a cross-sectional view of the sealing structure of a miniature valve according to various exemplary embodiments.

[0023] Figure 16 It is a bottom view of a sealing component comprising three sets of concentric sealing blades, according to the implementation plan.

[0024] Figure 17 This is a flowchart of a method for constructing a sealing structure for a micro-valve according to an exemplary embodiment.

[0025] Figure 18 This is a cross-sectional view of the sealing structure of a miniature valve according to an exemplary embodiment.

[0026] Figure 19 This is a flowchart of a method for constructing a sealing structure for a micro-valve according to an exemplary embodiment.

[0027] Figure 20 This is a flowchart of a method for constructing a microvalve according to an exemplary embodiment.

[0028] Figure 21 A cross-sectional view of the sealing member of a miniature valve according to an exemplary embodiment is shown.

[0029] Figure 22 A cross-sectional view of the valve seat of a miniature valve according to an exemplary embodiment is shown.

[0030] Figure 23 This is a cross-sectional view of the sealing structure of a miniature valve according to another exemplary embodiment.

[0031] Figure 24 This is an illustrative process flow for forming a sealing structure on a valve seat according to another exemplary embodiment.

[0032] Figure 25 This is a cross-sectional view of a miniature valve that may be included in the injection assembly according to an exemplary embodiment.

[0033] Figure 26 yes Figure 25 The injection assembly is made of Figure 25 The enlarged view of the portion indicated by arrow A in the image.

[0034] Figure 27 Is included Figures 25 to 26 The sealing blades in the miniature valve along Figure 26 The top cross section view is taken from line BB in the middle.

[0035] Figure 28A This is a cross-sectional view of a portion of the spray assembly according to the implementation scheme; Figure 28B yes Figure 28A The injection assembly is made of Figure 28A The enlarged view of the section indicated by arrow B in the image.

[0036] Figure 29 This is a side cross-sectional view of the spray assembly according to another embodiment.

[0037] Figure 30 This is a cross-sectional view of the actuation beam of the injection assembly according to an exemplary embodiment.

[0038] Figure 31 This is a cross-sectional view of the actuation beam of the injection assembly according to an exemplary embodiment. Detailed Implementation

[0039] Before turning to the accompanying drawings, which illustrate exemplary embodiments in detail, it should be understood that this application is not limited to the details or methods set forth in the specification or shown in the drawings. It should also be understood that the terminology is used for descriptive purposes only and should not be considered limiting.

[0040] Referring generally to the accompanying drawings, an ejection assembly comprising multiple microvalves is described herein. The microvalve described herein employs an actuation beam having a sealing member disposed thereon. This use of an actuation beam allows for the customization of the microvalve to eliminate or reduce various drawbacks associated with conventional technologies including continuous inkjet ejection assemblies. For example, in various embodiments, the microvalve includes a spacer member disposed between the actuation beam and an orifice plate. The spacer member maintains a gap between a first end of the actuation beam and an orifice within the orifice plate to prevent pressure damping of the actuation beam. The actuation beam extends from the spacer member above the orifice, and the sealing member extends toward the orifice to form a seal at the orifice. Thus, the sealing member seals the orifice without any electrical energy being applied to the actuation beam. In other words, the default position of the actuation beam (e.g., constructed by carefully selecting the material contained therein) is that the microvalve is closed. This isolates the fluid disposed within the microvalve (e.g., ink, solvent, etc.) from the external environment of the ejection assembly. This eliminates fluid evaporation, thereby reducing clogging. In addition, the limited evaporation allows for the use of inks that dry faster, which enables printing at higher speeds than conventional systems.

[0041] To ensure superior performance of the injection assembly, the microvalve described herein includes a sealing structure configured to form a seal separating the orifice from the volume of the adjacent actuating beam when the actuating beam is in its default position. The sealing structure can include any combination of multiple components designed to ensure seal formation. For example, in various embodiments, the sealing structure includes a valve seat disposed on an orifice plate adjacent to the orifice. The valve seat may surround the orifice and define an opening overlapping the orifice to define a fluid outlet. The sealing member may contact the valve seat when the actuating beam is in its default position. In some embodiments, the valve seat is constructed of a compliant material to facilitate an enhanced seal resulting from pressure exerted due to bending of the actuating beam.

[0042] On the other hand, the sealing structure may include a component attached to or extending from the sealing member. For example, in one embodiment, the sealing structure includes a stop extending from the orifice-facing surface of the sealing member. The stop may include a narrow portion and a wider portion having a cross-sectional area larger than the orifice. Therefore, the actuating beam compresses the stop toward the orifice plate to facilitate seal formation. Alternatively or additionally, the sealing structure may include a sealing blade extending from the orifice-facing surface to contact a valve seat or orifice plate. Due to the pressure generated by its relatively small cross-sectional area, the sealing blade further facilitates seal formation, which concentrates the downward pressure applied via the actuating beam to a single point to form a tight seal. Thus, the various structures described herein enhance the seal formed when the actuating beam is in its default position.

[0043] As described herein, when used to describe the actuation beam of a miniature valve, the term "default position" describes the position of the actuation beam relative to various other components of the miniature valve when no control signal (e.g., charge, current, or voltage) is applied to the actuation beam. In other words, the default position is the position of the actuation beam (and any components attached thereto) when the actuation beam is in a passive state. It should be understood that other embodiments are conceivable where the default position is the open position of the actuation beam.

[0044] Now for reference Figure 1According to an exemplary embodiment, a perspective view of an injection assembly 100 disposed in a retainer 150 is shown. The injection assembly 100 includes a valve body 102 attached to a carrier 108. The retainer 150 includes a generally circular body having an opening therein adapted to receive the injection assembly 100. The body of the retainer 150 may include a recess 118 extending from its peripheral edge to facilitate attachment of the retainer 150 to a marking device. The valve body 102 may be a component of the marking device. In an exemplary embodiment, the valve body 102 is used in an industrial marking device that includes a pressurized ink supply device. In other embodiments, the valve body 102 or any of the micro-valve described herein may be used in pneumatic applications where the fluid includes a gas (e.g., air, nitrogen, oxygen, etc.).

[0045] As described herein, valve body 102 includes an input fluid manifold attached to a plurality of microvalves. The microvalves and the input fluid manifold form a fluid booster chamber or fluid reservoir configured to contain fluid received from an external fluid supply device. In other embodiments, valve body 102 may define a plurality of fluid booster chambers, each corresponding to at least a portion of the plurality of microvalves. In such embodiments, each fluid booster chamber may be filled with a different colored ink (e.g., black, green, yellow, cyan, etc.) or a different fluid to provide a multi-color spray assembly or multi-fluid deposition assembly. In various embodiments, the microvalves include an actuation beam configured to move (e.g., bend, flex, twist, etc.) in response to a voltage applied thereto, temporarily opening a fluid outlet at an orifice in an orifice plate. Droplets are then ejected from the fluid outlet onto a target to produce a desired marking pattern on the target.

[0046] As shown, circuit board 104 is attached to the side surface of carrier 108. Circuit board 104 may include multiple electrical paths and provides a connection point (e.g., via wiring harness) between valve body 102 and electrical controller. The electrical controller may provide control signals via the electrical paths to control the actuation of actuation beams of multiple microvalves included in valve body 102. The structure and function of such microvalves are described in more detail herein. In some embodiments, circuit board 104 itself includes a microcontroller that generates and provides control signals to actuate the microvalves.

[0047] An identification tag 106 is attached to the injection assembly 100. In some embodiments, the identification tag 106 includes internal memory configured to store various forms of information about the injection assembly 100 (e.g., manufacturing information, serial number, valve calibration information, settings, etc.). For example, in one embodiment, the identification tag 106 is a radio frequency identification (RFID) tag configured to transmit the stored information in an acceptable manner in response to receiving a predetermined identifier from an external device. This allows for quick and efficient retrieval of information about the injection assembly 100.

[0048] Now for reference Figure 2 An exploded view of an injection assembly 100 according to an exemplary embodiment is shown. The carrier 108 includes a front surface 110, a rear surface 112, and a side surface 124. In various embodiments, a valve body 102 is attached to the front surface 110 via an adhesive. The rear surface 112 has a cap 116 disposed thereon. The cap 116 includes an orifice 120 that provides a supply port for fluid (e.g., ink) to be deposited onto a target via the valve body 102. For example, in some embodiments, fluid (e.g., ink) is supplied to the valve body 102 via a first orifice of these orifices 120 (e.g., via an inlet supply line or hose), circulates through the valve body 102, and exits from the valve body 102 via a second orifice of these orifices 120. In other words, the fluid is recirculated through a fluid pressurization chamber. A diaphragm may be positioned in each of these orifices 120 and configured to allow a fluid delivery or fluid return needle to be inserted therethrough, thereby allowing fluid communication into the fluid pressurization chamber while maintaining a fluid seal of the injection assembly 100. In certain embodiments, the diaphragm may comprise a single diaphragm sheet extending below each of the first and second holes in these orifices. Although not shown, in some embodiments, a heating element (e.g., a resistance wire) may be positioned close to the valve body 102 or the carrier 108 (e.g., surrounding or coupled to its sidewalls). The heating element may be used to selectively heat the fluid contained within the fluid pressurization chamber (e.g., ink) to maintain the fluid at a desired temperature. Furthermore, a temperature sensor (not shown), such as a thermally sensing resistor, may be disposed in the carrier 108, for example, to determine the temperature of the fluid flowing through the jet assembly 100.

[0049] The front surface 110 includes a cavity adapted to receive the valve body 102, such that the valve body 102 is securely mounted to the front surface 110 (e.g., via adhesive). The circuit board 104 is attached to the carrier 108 via a side surface 124. As shown, the side surface 124 includes mounting pins 126. In various embodiments, the circuit board 104 includes holes arranged in a manner corresponding to the arrangement of the mounting pins 126 and adapted to receive the mounting pins 126 to align the circuit board 104 with the carrier 108.

[0050] As shown, circuit board 104 has flexible circuitry 114 attached thereto. Flexible circuitry 114 extends from circuit board 104 at an angle and is attached to carrier 108 adjacent to front surface 110. Valve body 102 and circuit board 104 are arranged perpendicular to each other as flexible circuitry 114 extends around the corner boundary of front surface 110. Circuit board 104 also includes a controller interface 122, which includes electrical connection members (e.g., pins) configured to receive control signals from a marking system controller.

[0051] As described herein, in various embodiments, the flexible circuit 114 may be disposed between the fluid manifold and the carrier 108, or between the carrier 108 and the valve body 102, to facilitate the formation of an electrical connection between the flexible circuit 114 and the electrodes of the plurality of microvalves included in the valve body 102. In some embodiments, the flexible circuit 114 is attached to the front surface 110 via a mounting member 148. An opening in the flexible circuit 114 is aligned with a diaphragm in the carrier 108 to provide a fluid inlet to the fluid pressurization chamber formed via the valve body 102.

[0052] Now for reference Figure 3 A schematic diagram of various components of the spray assembly 100 is shown according to an exemplary embodiment. For example, Figure 3 The spray assembly 100 can be depicted in Figure 1 The figure shows a cross-sectional view at line II. As shown, the valve body 102 extends from the front surface 110 of the carrier 108 via an insert 170. The insert 170 provides structural support to ensure maximum performance of the various components within the valve body 102. Although not shown, in some embodiments, a compliant layer (e.g., a silicone or rubber layer) may also be disposed above or below the insert 170 or at any other location in the stack to provide stress relief.

[0053] Valve body 102 includes an inlet fluid manifold 162 and a plurality of micro-valve 164 attached to the inlet fluid manifold 162. The micro-valve 164 and the inlet fluid manifold 162 form a fluid pressurization chamber or fluid reservoir 166 for receiving fluid (e.g., a combination of ink and replenishment fluid) from a pressurized fluid supply device (e.g., via an orifice 120 in a cap 116 attached to the rear side surface 112). In various embodiments, the fluid supply device includes a fluid reservoir and a pump configured to supply pressurized fluid to the jet assembly 100 via a supply line coupled to carrier 108. In various embodiments, the fluid supply device supplies fluid pressurized between 7 PSI and 15 PSI when one or more of the micro-valve 164 are open. For example, in one embodiment, the fluid has a pressure of approximately 10 PSI. Carrier 108 may include an internal cavity configured to receive pressurized fluid and deliver fluid to the fluid pressurization chamber 166. In various implementations, a pressure differential can be maintained between the fluid pressurization chamber and the fluid supply device in order to drive the fluid out of the valve body 102.

[0054] The inlet fluid manifold 162 may include a glass structure comprising channels forming a fluid pressurization chamber. Typically, the microvalve 164 includes an actuation beam spaced apart from orifices on an orifice plate at the front surface 110. The actuation beam may include at least one piezoelectric layer configured to deflect in response to a received control signal (e.g., a voltage waveform provided via a controller interface 122 on circuit board 104). As described herein, applying such an electrical signal causes the microvalve 164 to open, resulting in the release of a droplet at the orifice plate. The droplet is advanced a projectile distance 192 on substrate 190 to create a desired pattern on substrate 190. In some embodiments, the weight of a single fluid droplet dispensed by the microvalve 164 or any other microvalve described herein can range from 200 nanograms to 300 nanograms. In some embodiments, the volume of a single dispensed droplet can range from 200 picoliters to 300 picoliters. The structure and function of the various components of the microvalve 164 are described in more detail herein. In other embodiments, the actuating beam may comprise a stainless steel actuating beam (e.g., having a length of approximately 1 mm). In other embodiments, the actuating beam may comprise a dual piezoelectric wafer beam having two piezoelectric material layers disposed on either side of a base layer (e.g., a silicon or stainless steel layer). An electrical signal (e.g., a voltage) may be applied to either of these piezoelectric layers to cause the actuating beam to bend toward the corresponding piezoelectric layer. The two piezoelectric layers may comprise the same piezoelectric material or different piezoelectric materials. In a particular embodiment, different electrical signals may be applied to each of these piezoelectric layers to bend the actuating beam toward or away from the orifice or to bend it a predetermined distance.

[0055] While the embodiments described herein generally depict the actuating beam as comprising a piezoelectric material, other actuation mechanisms may be used in other embodiments. For example, in some embodiments, the actuating beam may include capacitive coupling for moving the actuating beam. In other embodiments, the actuating beam may include electrostatic coupling. In other embodiments, the actuating beam may include magnetic coupling (e.g., an electromagnetic structure activated by an electromagnet) for moving the beam. In other embodiments, the actuating beam may include a temperature-sensitive bimetallic strip configured to move in response to temperature changes.

[0056] Insert 170 typically adds rigidity to various parts of valve body 102. For example, insert 170 may be configured to be more rigid than components of valve body 102 (e.g., orifice plates, actuation beams, etc.) to counteract stresses arising from attaching such components to each other. For example, insert 170 may be attached to valve body 102 to counteract stresses arising from adhesives used to attach carrier 108 to valve body 102. Additionally, insert 170 may counteract stresses at the interface between inlet manifold 162 and microvalve 164.

[0057] Now for reference Figure 4A The diagram shows a plan view of the spray assembly 100 according to an example embodiment. Figure 4A The valve body 102 is shown in Figure 2 The plan view at line II-II shown. Thus, Figure 4A A cross-sectional view is shown at the interface between the inlet fluid manifold 162 and the orifice plate. The inlet fluid manifold 162 includes a first opening 172 and a second opening 174. The first opening 172 exposes a plurality of microvalves 164 to form a fluid booster chamber 166 configured to contain fluid received from a fluid supply device.

[0058] In the example shown, the plurality of micro-valve 164 includes a plurality of actuating beams 176 aligned in a single row. Each of the plurality of actuating beams 176 has a sealing member 178 disposed at its end. In some embodiments, the sealing member 178 is aligned with and contacts a valve seat disposed at an orifice in an orifice plate to prevent fluid contained in the fluid pressurization chamber 166 from escaping the fluid pressurization chamber 166 without any electrical signal. The injection assembly 100 is shown as including 52 actuating beams 176 forming 52 micro-valve 164.

[0059] In various embodiments, each of the plurality of actuating beams 176 may include an electrical connection portion exposed via a second opening 174. Electrical contact pads 180 are provided at each of these electrical connection portions. Wire bonding connects each of these electrical connection portions to the controller interface 122 via the electrical contact pads 180. Thus, electrical signals can be received by each of the actuating beams 176 via the electrical contact pads 180. In some embodiments, tape-and-reel automatic bonding (TAB) may be used to connect each of these electrical connection portions to the controller interface.

[0060] The boundary between the first opening 172 and the second opening 174 isolates the electrical contact pad 180 from the fluid contained in the reservoir formed by the first opening 172. Also advantageously, the electrical contact pad 180 is located below the inlet fluid manifold 162. This means that the electrical connection between the actuating beams 176 is located inside the carrier 108 and is protected from degradation and external contamination.

[0061] To isolate the electrical contact pads 180 from the fluid contained in the fluid pressurization chamber 166, an adhesive structure 182 is provided on the inlet fluid manifold 162. The adhesive structure 182 connects the inlet fluid manifold 162 to the orifice plate. Figure 4A As shown, the adhesive structure 182 forms a "racetrack" around each of the first opening 172 and the second opening 174. The racetrack provides a barrier to fluid leaking between the inlet manifold 162 and the orifice plate, and prevents particles from entering the inlet manifold. The racetrack adhesive structure 182 may be present on one or both of the inlet manifold 162 side or the orifice plate side. For example, the racetrack may consist of several concentric rectangular rings of adhesive material (e.g., a negative photoresist such as bisphenol A phenolic glycidyl ether photoresist sold under the trade name SU-8, or polymethyl methacrylate, polydimethylsiloxane, silicone rubber, etc.) surrounding each of the first opening 172 and the second opening 174. Fragments of adhesive material may be cut through the multiple rectangular rings to form compartments for receiving leaked fluid. Such an adhesive structure 182 facilitates fluid isolation between the microvalve 164 and the electrical contact pad 180. In other embodiments, the adhesive structure 182 may be formed of silicon and used to bond the inlet manifold 162 to the orifice plate via fusion bonding, laser bonding, adhesives, eutectic bonding, glass powder, solder, adhesion, etc. The adhesive structure 182 may be disposed on the inlet manifold 162 and the valve body 102 coupled thereto, disposed on the valve body 102 and the inlet manifold 162 coupled thereto, or disposed on each of the inlet manifold 162 and the valve body 102 prior to coupling both.

[0062] In some implementations, the adhesive structure 182 may be ventilated. For example, Figure 4B A schematic diagram of the adhesive structure 182b is shown. The adhesive structure 182b can be formed of SU-8, silicon, or any other suitable material and includes a plurality of rings 189b, such that the adhesive structure has a racetrack shape. The innermost ring of the plurality of rings 189b surrounding the input fluid manifold 162 forms a closed loop. In contrast, the remaining rings of the plurality of rings 189b positioned radially outward of the innermost ring include vent holes 183b, such as slots or openings defined therein. The vent holes 183b facilitate bonding the input fluid manifold 162 to the orifice plate by allowing air that might be trapped between the plurality of rings 189b of the adhesive structure 182b to escape via the vent holes 183b. Although Figure 4B The illustration shows ventilation holes 183b radially aligned with each other and located at the corner of each ring; however, in other embodiments, one or more ventilation holes 183b of a ring may be radially offset from ventilation holes defined in adjacent rings.

[0063] like Figure 4B As shown, the corners of each ring in the adhesive structure 182b may be rounded. Furthermore, the corners of any other layer or component included in the inlet fluid manifold 162, insert 170, flexible circuit 114, or jet assembly 100 may be rounded, for example, to reduce stress concentration that may occur at sharp corners.

[0064] Now for reference Figure 5A A cross-sectional view of an injection assembly 200 including a micro-valve 230 is shown according to an exemplary embodiment. In some embodiments, the injection assembly 200 is relative to... Figure 1 , Figure 2 , Figure 3 and Figures 4A to 4B An exemplary embodiment of the injection assembly 100 is described. As shown, the injection assembly 200 includes a carrier 202 attached to a valve body 298 via a structural layer 222. In some embodiments, the carrier 202 may include the structural layer 222.

[0065] The carrier 202 includes an upper portion 204 and a housing portion 206 extending from the edge of the upper portion 204. The upper portion 204 includes a diaphragm 208 through which pressurized ink is supplied. The housing portion 206 defines a cavity in which a valve body 298 is disposed. The valve body 298 includes an inlet fluid manifold 210 and a micro-valve 230. As shown, the inlet fluid manifold 210 and the micro-valve 230 define a reservoir 300 configured to contain a volume of pressurized fluid received from an external fluid supply device via the diaphragm 208. In various embodiments, the pressurized fluid contained in the reservoir 300 is a combination of ink and a liquid adjunct fluid.

[0066] The carrier 202 can be formed of plastic, ceramic, or any other suitable material. The carrier 202 facilitates the operation of the injection assembly 200 by providing structural support to the valve body 298. For example, in some embodiments, the peripheral edge of the valve body 298 is attached to the housing portion 206 via an adhesive layer 302 disposed on the inner surface of the housing portion 206. This adhesive facilitates maintaining the desired relative position between the microvalve 230 and the inlet fluid manifold 210.

[0067] In various embodiments, the inlet fluid manifold 210 is pre-formed before being attached to the additional components of the jet assembly 200. The inlet fluid manifold 210 is formed from a body 310 (e.g., formed of glass, silicon, silica, etc.) having any suitable thickness (e.g., 500 micrometers). As shown, the inlet fluid manifold 210 is pre-formed to include a first arm 330, a second arm 332, and a third arm 334. As used herein, when describing the inlet fluid manifold 210, the term "arm" is used to describe a structure separating the opening contained within the inlet fluid manifold 210. Thus, arms 330, 332, and 334 can have any suitable shape. For example, in some embodiments, arms 330, 332, and 334 are substantially rectangular with substantially flat side surfaces. In other embodiments, the side surfaces may be angled, such that arms 330, 332, and 334 are substantially trapezoidal in shape. Arms 330, 332, and 334 can be formed by creating openings in the structure (e.g., silicon or glass structure) using any suitable method (e.g., wet etching or dry etching, such as deep reactive ion etching).

[0068] As shown in the figure, a first channel 212 separates arms 330 and 332 from each other, and a second channel 214 separates arms 332 and 334 from each other. In the illustrated embodiment, the first and second channels 214 are substantially linear and parallel to each other, but the input fluid manifold 210 can be arranged as needed to accommodate the microvalve. The first channel 212 is formed with a width 304 that has a predetermined relationship to the length 312 of the cantilever portion 308 of the actuation beam 240 of the microvalve 230 (e.g., in the range of approximately 500 to 1000 micrometers). For example, the first channel 212 can be formed with a width 304 that is a threshold amount larger than the desired length 312 of the cantilever portion 308. The second channel 214 provides a pathway for forming an electrical connection between the actuation beam 240 and the flexible circuit 216 via a wire bond 220 extending therebetween. Advantageously, this arrangement internalizes the electrical connection between the actuation beam 240 and the flexible circuit 216. In other words, the electrical connections between such components are not outside the carrier 202, and are therefore less prone to degradation. In various embodiments, the first channel 212 and / or the second channel 214 may have sloping sidewalls.

[0069] As shown, the second channel 214 is substantially filled with a sealant 218. The sealant 218 may comprise an epoxy resin or any other suitable material. The sealant 218 encapsulates the electrical connection formed between the wire bond 220, the flexible circuit 216, and the actuation beam 240, and is configured to protect the wire bond 220 from physical damage, moisture, and corrosion. Therefore, the sealant 218 ensures the maintenance of a sufficient electrical connection between the flexible circuit 216 and the actuation beam 240 to facilitate the supply of electrical control signals to the actuation beam 240 to cause its movement to open and close the micro-valve 230.

[0070] The second arm 332 serves as a barrier to prevent fluid contained in the reservoir 300 from reaching the electrical connection. The portion 314 of the inlet fluid manifold 210 that separates the first channel 212 and the second channel 214 also serves as a barrier to prevent fluid contained in the reservoir 300 from reaching the electrical connection. Thus, the inlet fluid manifold 210 serves both as part of the reservoir 300 for pressurized fluid received from an external fluid supply device and as an insulating barrier between the pressurized fluid and any electrical connections contained within the jet assembly 200. The first channel 212 and the second channel 214 can be formed using any suitable process (e.g., via sandblasting, physical etching, or chemical etching, drilling). In some embodiments, the inlet fluid manifold 210 is not made of glass, but of silicon, silica, ceramic, or any other suitable material. In some embodiments, the inlet fluid manifold 210 can be bonded to the microvalve 230 via glass powder, solder, or any other suitable adhesive.

[0071] Continue to refer to Figure 5A The micro-valve 230 includes an orifice plate 250 attached to the actuation beam 240. The orifice plate 250 can be formed of any suitable material, such as glass, stainless steel, nickel, nickel with another electroplated metal layer (e.g., stainless steel), polyimide (e.g., kapton), or a negative photoresist (e.g., SU-8, polymethyl methacrylate, etc.). In some embodiments, the orifice plate 250 can be substantially flat, for example, having a flatness with a coefficient of variation of less than 3 micrometers over at least 15 mm of length and width, such that the orifice plate 250 is substantially free from bending or twisting. Furthermore, the orifice plate 250 can have any suitable thickness. In some embodiments, the orifice plate 250 can have a thickness in the range of 30 micrometers to 60 micrometers (30 micrometers, 40 micrometers, 50 micrometers, or 60 micrometers). In other embodiments, the orifice plate 250 may have a thickness in the range of 100 micrometers to 400 micrometers (e.g., 100 micrometers, 150 micrometers, 200 micrometers, 250 micrometers, 300 micrometers, 350 micrometers, or 400 micrometers). A thicker orifice plate 250 facilitates the creation of a flatter orifice plate.

[0072] The orifice plate 250 is substantially flat and includes an orifice 260 extending between its surfaces. In various embodiments, the orifice 260 is substantially cylindrical in shape and has a central axis perpendicular to or substantially perpendicular to the surface of the orifice plate 250. A valve seat 270 is disposed adjacent to the orifice 260 on the inner surface 316 of the orifice plate 250. In various embodiments, the valve seat 270 includes a compliant material that surrounds or substantially surrounds the orifice 260. In some embodiments, the valve seat 270 is made of an epoxy-based adhesive such as SU-8 photoresist. In other embodiments, the valve seat 270 may be formed of a moldable polymer such as polydimethylsiloxane or silicone rubber. In other embodiments, the valve seat 270 may be formed of a non-compliant material such as silicon. In some embodiments, a compliant layer, such as a gold layer, may be provided on the surface of the valve seat 270 that contacts the actuating beam 240. Valve seat 270 defines an internal opening 318 that is substantially aligned with orifice 260 to form an outlet for pressurized fluid contained in reservoir 300. In a particular embodiment, valve seat 270 may be excluded.

[0073] As shown, the actuation beam 240 includes a base portion 306 and a cantilever portion 308. The base portion 306 extends below a portion 314 of the input fluid manifold 210 that separates the first channel 212 and the second channel 214. As shown, the base portion 306 includes an electrical connection portion 294 in the region overlapping with the second channel 214. The electrical connection portion 294 includes an electrode through which an electrical connection is formed with a flexible circuit 216 via wire bonding 220. The cantilever portion 308 extends from the portion 314 of the input fluid manifold 210 into the reservoir 300. As shown, the cantilever portion 308 is disposed on the spacer member 280 and is therefore spatially separated from the orifice plate 250. Thus, a space exists on either side of the cantilever portion 308 such that the actuation beam 240 can be bent toward and / or away from the orifice plate 250 due to an electrical signal applied to it via the electrical connection portion 294. The spacer member 280 is configured to prevent pressure damping of the actuation beam.

[0074] The cantilever portion 308 has a length 312 such that it extends a predetermined distance from the boundary of the reservoir 300. In various embodiments, the predetermined distance is specifically chosen such that a portion 292 of the cantilever portion 308 overlaps with the valve seat 270 and the orifice 260. The sealing member 290 extends from the portion 292 of the actuating beam 240 that overlaps with the orifice 260. In some embodiments, the sealing member 290 is configured to have a shape substantially corresponding to the shape of the orifice 260. For example, in one embodiment, both the orifice 260 and the sealing member 290 are substantially cylindrical in shape, with the sealing member 290 having a larger outer diameter. This configuration facilitates the sealing member 290 to completely cover the orifice 260, enabling a seal to be formed between the sealing member 290 and the valve seat 270. In other embodiments, the orifice 260 may have any other shape, such as star-shaped, square, rectangular, polygonal, elliptical, or asymmetrical. In a particular embodiment, the valve seat 270 may define a recess size and be shaped to receive the sealing member 290. In various embodiments, the orifice plate 250 and thus the orifice 260 may be formed of a non-wetting (e.g., hydrophobic) material such as silicon or Teflon. In other embodiments, a non-wetting (e.g., hydrophobic) coating may be provided on the inner wall or surface of the orifice 260 or on the fluid outlet formed by the valve seat 270 and the orifice 260. Such a coating may include, for example, Teflon, nanoparticles, an oleophilic coating, or any other suitable coating.

[0075] In various embodiments, the spacer member 280 and the sealing member 290 are made of the same material and have equal or substantially equal thicknesses 320 and 322 (e.g., silicone, SU-8, silicone rubber, polymethyl methacrylate, etc.). In such embodiments, the lower surfaces of the spacer member 280 and the sealing member 290 are aligned with each other when the actuating beam 240 extends parallel to the orifice plate 250. When the actuating beam 240 is in the closed position (as described herein), the surface of the sealing member 290 contacts the valve seat 270 to close the fluid outlet formed at the orifice 260 (e.g., if the valve seat 270 is not present, the sealing member surface of the sealing member 290 may be configured to extend approximately 2 micrometers below the lower surface of the spacer member 280). The valve seat 270 and sealing member 290 are sized such that when the actuation beam 240 is in the closed position (e.g., when an electrical signal is removed from or applied to the actuation beam 240 via wire bonding 220), sufficient surface area of ​​the sealing member 290 contacts the valve seat 270 to prevent fluid from traveling from the reservoir 300 to the orifice 260. For example, the sealing member 290 may have a larger diameter or cross-section than the valve seat 270. In other embodiments, the sealing member 290 may have a smaller diameter or cross-section than the valve seat 270. In some embodiments, a compliant material (e.g., a gold layer) may be provided on the surface of the sealing member 290 configured to contact the valve seat 270.

[0076] Various aspects of the injection assembly 200 are designed to ensure a sufficient seal is formed between the valve seat 270 and the seal 290. For example, a structural layer 222 disposed on the inlet fluid manifold 210 prevents the orifice plate 250 from buckling due to stresses induced on the orifice plate by the adhesives used to join the components of the microvalve 230 to each other and to attach the microvalve 230 to the housing portion 206. In various embodiments, the structural layer 222 is configured to have greater rigidity than the orifice plate 250 to perform this function. The structural layer 222 may be made of silicon or any other suitable material. As shown, the structural layer 222 includes a protrusion 224 extending from its main portion. The protrusion 224 is attached to the upper surface of the inlet fluid manifold 210 (e.g., at the boundary between the first channel 212 and the second channel 214). In some embodiments, the protrusion 224 is omitted. A seal is formed at the protrusion 224 via, for example, an adhesive disposed between the structural layer 222 and the flexible circuit 216. The protrusion 224 provides a gap above the inlet fluid manifold 210. This gap facilitates the application of sealant 218 to completely cover all contact points between the wire bond 220 and the flexible circuit 216. In some embodiments, the carrier 202 may include a structural layer 222 such that stiffness is provided by the carrier 202.

[0077] On the other hand, the actuation beam 240 is configured such that a tight seal is formed at the interface between the valve seat 270 and the sealing member 290 when in the closed position. The actuation beam 240 may include at least one piezoelectric material layer. The piezoelectric material layer may include lead zirconate titanate (PZT) or any suitable material. The piezoelectric material layer has electrodes electrically connected thereto. In various embodiments, wire bonding 220 is attached to the electrodes such that an electrical signal from the flexible circuit 216 is provided to the piezoelectric material layer via the electrodes. The electrical signal causes the actuation beam 240 to move relative to its default position (e.g., bending, rotating, etc.). In other embodiments, the actuation beam 240 may include a stainless steel actuation beam (e.g., having a length of approximately 1 mm). In other embodiments, the actuation beam 240 may include a dual piezoelectric wafer beam having two piezoelectric material layers disposed on either side of a base layer (e.g., a silicon substrate). An electrical signal (e.g., a voltage) may be applied to either of these piezoelectric layers to cause the actuation beam to bend toward the corresponding piezoelectric layer. The two piezoelectric layers may comprise the same piezoelectric material or different piezoelectric materials. In a particular embodiment, different electrical signals may be applied to each of these piezoelectric layers to bend or deflect the actuated beam by a predetermined distance.

[0078] As shown, wire bond 220 is attached to actuation beam 240 at its electrical connection portion 294. Electrical connection portion 294 includes wire bond pads (e.g., made of gold, platinum, rubidium, etc.) electrically connected to at least one electrode within actuation beam 240. Advantageously, electrical connection portion 294 is separated from the cantilever portion of actuation beam 240. In other words, electrical connection portion 294 is separated from the fluid contained in the jet assembly 200 via a seal formed at the connection point between the inlet fluid manifold 210 and actuation beam 240. In some embodiments, wire bond 220 and / or sealant 218 can be led out through openings provided in orifice plate 250.

[0079] In various embodiments, the actuation beam 240 is configured such that the closed position is its default position. In other words, the layers within the actuation beam 240 are configured such that the actuation beam bends toward the orifice 260 due to the force provided by the pressurized fluid contained in the container. Tuning layers within the actuation beam 240 may be configured to be under compressive stress to induce bending toward the orifice within the actuation beam. Due to this bending, for example, even without any electrical signal applied to the actuation beam 240 to close the fluid outlet, the sealing member 290 contacts the valve seat 270. The degree of bending can be specifically selected to form a tight seal at the interface between the sealing member 290 and the valve seat 270 when the actuation beam 240 is in the default position. Advantageously, this default seal prevents evaporation of the fluid contained in the injection assembly 200, thereby preventing blockages and other defects.

[0080] like Figure 5A As shown, the actuation beam 240 bends away from the orifice plate 250. This bending is caused by applying an electrical signal to the actuation beam 240 via the flexible circuit 216. For example, the flexible circuit 216 can be electrically connected to an external controller that provides the electrical signal relayed to the actuation beam 240.

[0081] like Figure 5A As shown, the application of an electrical signal causes the actuation beam 240 to temporarily move away from its default position. For example, in various embodiments, the actuation beam 240 moves upward away from the orifice 260 such that a portion of the sealing member surface of the sealing member 290 is at least 10 micrometers away from the upper surface of the valve seat 270. In one embodiment, the central portion of the sealing member surface is approximately 15 micrometers away from the valve seat 270 at the peak of its oscillation mode. Thus, an opening is temporarily formed between the valve seat 270 and the sealing member 290. This opening provides a path for a given volume of fluid to enter the orifice 260 to form droplets on the outer surface of the orifice plate 250. The droplets are deposited onto the substrate to form a pattern, which is determined by a control signal provided to each actuation beam 240 of each microvalve 230 of the injection assembly 200. It should be understood that the frequency at which the actuation beam 240 deviates from its default position to the position shown in FIG. 5 can vary depending on the implementation. For example, in one embodiment, the actuation beam 240 oscillates at a frequency of approximately 12 kHz. However, in other embodiments, the actuating beam 240 may oscillate at a smaller (e.g., 10 kHz) or a larger (e.g., 20 kHz) frequency.

[0082] Now for reference Figure 5B A cross-sectional view of an injection assembly 200b, including a micro-valve 230b, is shown according to an exemplary embodiment. In some embodiments, the injection assembly 200b is relative to... Figure 1 , Figure 2 , Figure 3 and Figures 4A to 4B An exemplary embodiment of the injection assembly 100 is described. As shown, the injection assembly 200b includes a carrier 202b attached to a valve body 298b via an insert 222b.

[0083] The carrier 202b includes an upper portion 204b and a housing portion 206b extending from the edge of the upper portion 204b. A fluid channel 211b is provided in the upper portion 204b. A diaphragm 208b (e.g., a rubber or foam diaphragm) is positioned at the inlet of the fluid channel 211b, and a filter 213b is positioned at the outlet of the fluid channel 211b. A cap 203b (e.g., a plastic or glass cap) is positioned on the carrier 202b such that the diaphragm 208b is positioned between and secured between the carrier 202b and the cap 203b. An opening 209b may be defined in the cap 203b and corresponds to the inlet of the fluid channel 211b. A fluid connector 10b is coupled to the cap 203b or the inlet of the fluid channel 211b. The fluid connector 10b includes an insertion pin 12b configured to pierce the diaphragm 208b and pass through it into the fluid channel 211b. The fluid connector 10b is configured to pump pressurized fluid (e.g., ink) into the inlet fluid manifold 210b of the jet assembly 200b via the insert pin 12b. Furthermore, the filter 213b is configured to filter particles from the fluid before it is delivered to the reservoir 300b. In some embodiments, the insert pin 12b may be formed of or coated with a non-wetting material (e.g., a hydrophobic material such as Teflon). In other embodiments, the insert pin 12b may include a heating element, or an electric current may be supplied to the insert pin 12b to heat the insert pin 12b, thereby heating the fluid flowing through it to the reservoir 300b. In other embodiments, a metal needle or any other heating element may be provided in the inlet fluid manifold 210b to heat the fluid contained therein. Although shown as including only the fluid passage 211b, in some embodiments, the carrier 202b may also define a second fluid passage for allowing fluid to be drawn out of the carrier 202b, i.e., causing fluid circulation through the carrier 202b.

[0084] A housing portion 206b defines a cavity or boundary within which a valve body 298b is disposed. The valve body 298b includes an inlet fluid manifold 210b and a micro-valve 230b. As shown, the inlet fluid manifold 210b and the micro-valve 230b define a reservoir 300b configured to contain a volume of pressurized fluid received from an external fluid supply device via a diaphragm 208b. In various embodiments, the pressurized fluid contained within the reservoir 300b is a combination of ink and a liquid adjunct fluid.

[0085] In various embodiments, the inlet fluid manifold 210b is pre-formed before being attached to the additional components of the jet assembly 200b. The fluid manifold 210b can be formed from a glass body 310b having any suitable thickness (e.g., 500 micrometers). As shown, the inlet fluid manifold 210b is pre-formed to include a first channel 212b and a second channel 214b. The first channel 212b is formed to have a width 304b, which has a predetermined relationship to the length 312b of the cantilever portion 308b of the actuation beam 240b of the microvalve 230b. The second channel 214b provides a pathway for forming an electrical connection between the actuation beam 240b and the flexible circuit 216b via a wire bond 220b extending therebetween.

[0086] As shown in the figure, the second channel 214b is substantially filled with sealant 218b. Therefore, sealant 218b ensures the maintenance of a sufficient electrical connection between the flexible circuit 216b and the actuation beam 240b to provide an electrical control signal to the actuation beam 240b to cause its movement to open and close the micro valve 230b, and protects the lead bond 220b from physical damage or moisture, as described earlier herein.

[0087] The portion 314b of the inlet fluid manifold 210b that separates the first channel 212b and the second channel 214b serves as a barrier to prevent fluid contained in the reservoir 300b from reaching the electrical connections. Thus, the inlet fluid manifold 210b serves both as part of the reservoir 300b for pressurized fluid received from an external fluid supply device and as an insulating barrier between the pressurized fluid and any electrical connections contained within the jet assembly 200b.

[0088] The miniature valve 230b includes an orifice plate 250b attached to an actuation beam 240b. The orifice plate 250b is substantially flat and includes an orifice 260b extending between its surfaces. A valve seat 270b is disposed adjacent to the orifice 260b on an inner surface 316b of the orifice plate 250b. The valve seat 270b defines an internal opening 318b substantially aligned with the orifice 260b to form an outlet for pressurized fluid contained in a reservoir 300b. In certain embodiments, the valve seat 270b may be excluded. In some embodiments, the orifice plate 250b, or any other orifice plate described herein, may also be grounded. For example, an electrical grounding connector 295b (e.g., bonding pads such as gold bonding pads) may be disposed on the orifice plate 250b and configured to allow the orifice plate 250b to be electrically grounded (e.g., via an electrical connection to system ground).

[0089] The actuating beam 240b includes a base portion 306b and a cantilever portion 308b. The base portion 306b extends below a portion 314b of the input fluid manifold 210b that separates the first channel 212b and the second channel 214b. As shown, the base portion 306b includes an electrical connection portion 294b in the region overlapping with the second channel 214b. The electrical connection portion 294b includes an electrode through which an electrical connection is formed with a flexible circuit 216b via wire bonding 220b. The cantilever portion 308b extends from portion 314b of the input fluid manifold 210b into the reservoir 300b. As shown, the cantilever portion 308b is disposed on the spacer member 280b and is therefore spatially separated from the orifice plate 250b.

[0090] The cantilever portion 308b has a length 312b, such that the cantilever portion extends a predetermined distance from the boundary of the reservoir 300b. In various embodiments, the predetermined distance is specifically chosen such that a portion 292b of the cantilever portion 308b overlaps with the valve seat 270b and the orifice 260b. The sealing member 290b extends from the portion 292b of the actuating beam 240b that overlaps with the orifice 260b. In some embodiments, the sealing member 290b is configured to have a shape substantially corresponding to the shape of the orifice 260b.

[0091] The flexible circuit 216b is positioned on the glass body 310b and a portion 314b of the inlet fluid manifold 210b, and is coupled to it via a first adhesive layer 221b (e.g., SU-8, silicone rubber, glue, epoxy resin, etc.). An insert 222b is positioned between the upper portion 204b of the carrier 202b and the inlet fluid manifold 210b to create a gap between the upper portion 204b and the inlet fluid manifold 210b via the first adhesive layer 221b. This allows sufficient space for the placement of the sealant 218 and increases the volume of the inlet fluid manifold 210b. Figure 5B As shown, the insert 222b is positioned and attached to a portion of the flexible circuit 216b via a second adhesive layer 223b (e.g., SU-8, silicone, or any other adhesive). Furthermore, the insert 222b is attached to the sidewall of the upper portion 204b of the carrier 202b near the microvalve 230b via a third adhesive layer 225b (e.g., SU-8, silicone, or any other adhesive).

[0092] Insert 222b may be formed of a robust and rigid material (e.g., plastic, silicone, glass, ceramic, etc.) and is disposed on the inlet fluid manifold 210b to prevent orifice plate 250b from bending due to stress caused thereon by the adhesive used to connect the components of microvalves 230b to each other and to attach microvalves 230b to housing portion 206b. In various embodiments, insert 222b is configured to have greater rigidity than orifice plate 250b to perform this function.

[0093] On the other hand, the actuating beam 240b is configured such that a tight seal is formed at the interface between the valve seat 270b and the sealing member 290b when in the closed position. The actuating beam 240b may include at least one piezoelectric material layer (e.g., lead zirconate titanate (PZT) or any suitable material). The piezoelectric material layer has electrodes electrically connected thereto, and wire bonding 220b is attached to said electrodes such that an electrical signal from the flexible circuit 216b is provided to the piezoelectric material layer via the electrodes. The electrical signal causes the actuating beam 240b to move relative to its default position (e.g., bend, rotate, etc.).

[0094] As shown in the figure, wire bond 220b is connected to actuating beam 240b at its electrical connection portion 294b, essentially analogous to... Figure 5A The injection assembly 200 describes the wire bonding 220. In various embodiments, the actuating beam 240b is configured such that the closed position is its default position, as relative to... Figure 5A The actuating beam 240 is described in detail.

[0095] like Figure 5B As shown, the actuation beam 240b bends away from the perforated plate 250b. This bending is caused by applying an electrical signal to the actuation beam 240b via the flexible circuit 216b. For example, the flexible circuit 216b may be electrically connected to a circuit board 215b (e.g., a printed circuit board) that extends along the sidewall of the carrier 202b perpendicular to the longitudinal axis of the actuation beam 240b. An identification tag 217b (e.g., identification tag 106) may be positioned between the circuit board 215b and the sidewall of the carrier 202b. An electrical connector 219b is electrically coupled to the circuit board 215b and configured to electrically connect the flexible circuit 216b to an external controller that provides the electrical signal relayed to the actuation beam 240b via the circuit board 215b.

[0096] like Figure 5B As shown, the application of an electrical signal causes the actuation beam 240b to temporarily move away from its default position. For example, in various embodiments, the actuation beam 240b moves upward away from the orifice 260b, such that a portion of the sealing member surface of the sealing member 290b is at least 10 micrometers away from the upper surface of the valve seat 270b, as relative to... Figure 5AThe actuating beam 240 is described in detail.

[0097] Now for reference Figure 6 A more detailed view according to an exemplary embodiment is shown, which illustrates the relationship with respect to... Figure 5A Various components of the jet assembly 200 are described. As shown, the actuation beam 240 includes an actuation portion 242, a tuning layer 244, and an inactive layer 246. The inactive layer 246 serves as the base for the tuning layer 244 and the actuation portion 242. The structure of the actuation portion 242 and the tuning layer 244 is described in more detail with respect to FIG. 7. In some embodiments, the inactive layer 246 is made of silicon or other suitable material. In some embodiments, the inactive layer 246, the spacer member 280, and the sealing member 290 are all made of the same material (e.g., integrally formed from a silicon wafer). In an exemplary embodiment, the inactive layer 246, the spacer member 280, and the sealing member 290 are formed from a silicon-on-insulator (SOI) wafer.

[0098] Spacer 280 is shown as including an intermediate layer inserted between two peripheral layers. In an exemplary embodiment, the intermediate layer and inactive layer 246 comprise two silicon layers of a dual SOI wafer, with the peripheral layers disposed on either side of the intermediate layer, which includes a silicon dioxide layer. In this example, sealing member 290 and spacer 280 are formed by etching the surfaces of the dual SOI wafer opposite to actuation portion 242. For example, once the entire intermediate layer forming spacer 280 is removed in the region separating spacer 280 and sealing member 290, an oxide layer is used to control or stop the etching process. This process provides precise control over both the width and thickness of spacer 280 and sealing member 290.

[0099] It should be understood that the size of the sealing member 290 can contribute to the resonant frequency of the actuation beam 240. A larger amount of material disposed at or near the ends of the actuation beam 240 generally results in a lower resonant frequency. Additionally, this larger amount of material will affect the default bending of the actuation beam 240 caused by pressurized fluid contacting it. Therefore, the desired size of the sealing member 290 influences various other design choices for the actuation beam 240. Relative to Figure 7AThis design choice is described in more detail. In some embodiments, the size of the sealing member 290 is designed based on the size of the orifice 260. In some embodiments, the sealing member 290 is substantially cylindrical in shape and has a diameter approximately 1.5 times that of the orifice 260. For example, in one embodiment, when the orifice 260 has a diameter of approximately 60 micrometers, the sealing member 290 has a diameter of approximately 90 micrometers. This configuration facilitates alignment between the sealing member 290 and the orifice 260, such that the sealing member 290 completely covers the orifice 260 when contacting the valve seat 270. In another embodiment, the sealing member 290 is sized such that it has a surface area approximately twice that of the orifice 260 (e.g., the spacer member 280 may have a diameter of approximately 150 micrometers, while the orifice 260 has a diameter of approximately 75 micrometers). Such embodiments provide greater tolerance for aligning the sealing member 290 and the orifice 260 to facilitate the formation of a seal between the valve seat 270 and the sealing member 290. In other embodiments, the diameter of the sealing member 290 may be 2, 2.5, 3, 3.5, or 4 times the diameter of the orifice 260. In various embodiments, the length-to-diameter ratio of the orifice 260 may range from 1:1 to 15:1. This ratio can affect the shape, size, and / or volume of droplets ejected through the orifice and may vary depending on the specific application.

[0100] Advantageously, the gap 324 between the spacer member 280 and the sealing member 290 creates a separation volume 326 between the actuating beam 240 and the orifice plate 250. The separation volume 326 provides pressure damping to prevent oscillation of the actuating beam 240. In other words, insufficient separation between the orifice plate 250 and the actuating beam 240 would result in drag as fluid must enter and / or leave the separation volume 326 when the actuating beam 240 opens and closes the orifice 260. The larger separation volume created by the spacer member 280 reduces this drag and thus facilitates oscillation of the actuating beam 240 at a faster frequency.

[0101] Continue to refer to Figure 6 The orifice plate 250 includes a base layer 252 and an intermediate layer 254. For example, in one embodiment, the base layer 252 includes a silicon layer, and the intermediate layer 254 includes a silicon dioxide layer. In the illustrated embodiment, a portion of the intermediate layer 254 adjacent to the orifice 260 is removed, and a first portion of the valve seat 270 is disposed directly on the base layer 252, and a second portion of the valve seat 270 is disposed on the intermediate layer 254. It should be understood that in an alternative embodiment, the intermediate layer 254 extends to the boundary of the orifice 260, and the valve seat 270 is disposed on the intermediate layer 254. In other embodiments, the removed portion of the intermediate layer 254 may have a cross-section equal to or larger than the cross-section of the valve seat 270, such that the valve seat 270 is completely disposed on the base layer 252.

[0102] Due to the criticality of the spatial relationship between the spacer member 280 and the valve seat 270, the attachment of the spacer member 280 to the orifice plate 250 can be performed in a manner that allows precise control of the resulting distance between the actuating beam 240 and the orifice plate 250. As shown, an adhesive layer 256 is used to attach the spacer member 280 to the orifice plate 250. In various embodiments, a precise amount of epoxy-based adhesive (e.g., SU-8, polymethyl methacrylate, silicone, etc.) is applied to the intermediate layer 254 before the combination of the spacer member 280 and the actuating beam 240 is placed on the intermediate layer. The adhesive is then allowed to cure to form an adhesive layer 256 with a precisely controlled thickness. For example, in some embodiments, the lowermost surface of the spacer member 280 is substantially aligned with the upper surface of the valve seat 270. Any desired relationship between such surfaces can be obtained to form a relationship between the sealing member 290 and the valve seat 270 that provides a sufficient seal when the actuating beam 240 is in its default position. In various embodiments, the adhesive layer 256 and the valve seat 270 can be formed from the same material (e.g., SU-8) in a single photolithography process.

[0103] In various embodiments, once the actuation beam 240 and orifice plate 250 are attached to each other via adhesive layer 256 (e.g., to form microvalve 230), an additional adhesive layer 248 is applied to the periphery of the actuation beam 240. The additional adhesive layer 248 is used to attach the inlet fluid manifold 210 to the actuation beam 240. A structural layer 222 (or insert 222b) may be positioned on the inlet fluid manifold 210 and coupled to the inlet fluid manifold via a second adhesive layer 225. In some embodiments, the additional adhesive layer 248 and the second adhesive layer 225 may comprise the same material as adhesive layer 256.

[0104] In relative to Figure 6 In the illustrated example, the micro-valve 230 includes a sealing structure 500 comprising various components that form a seal to separate the orifice 260 from the volume 502 near the actuating beam 240. In the illustrated example, the sealing structure 500 includes a sealing member 290 and a valve seat 270. As described herein, the actuating beam 240 is configured such that the orifice-facing surface 504 of the sealing member 290 contacts the upper surface of the valve seat 270 to form a seal at the interface between the valve seat 270 and the sealing member 290. The seal isolates the orifice 260 from the volume 502 such that minimal fluid escapes from the jet assembly 200 when no electrical signal is applied to the actuating beam 240. Several alternatives to the sealing structure 500 are described in more detail herein. In other embodiments, the valve seat 270 may be omitted, such that the orifice-facing surface of the sealing structure 500 contacts the orifice plate 250 to fluidly seal the orifice 260.

[0105] Now for reference Figure 7A A more detailed view of the actuation beam 240 is shown according to an exemplary embodiment and not drawn to scale. As shown, the actuation beam 240 includes an inactive layer 246, a tuning layer 244, a blocking layer 400, a first electrode portion 402, an actuation portion 242, a second electrode portion 404, and a passivation structure 406. It should be understood that in various alternative embodiments, the actuation beam 240 may include more or fewer layers.

[0106] In some embodiments, tuning layer 244 is disposed directly on inactive layer 246. Tuning layer 244 typically serves as an adhesive layer to facilitate the deposition of the additional layers described herein. Additionally, as described herein, the thickness of tuning layer 244 can play a critical role in determining the overall curvature of actuation beam 240 in its default position. Generally, tuning layer 244 is configured with a predetermined tuning stress such that, in the closed position, sealing member 290 of actuation beam 240 contacts valve seat 270 and applies force to the valve seat to fluidly seal orifice 260. In some embodiments, in the absence of an electrical signal, the predetermined tuning stress is configured to cause actuation beam 240 to bend toward orifice 260 such that, in the absence of valve seat 270, the sealing member surface of sealing member 290 will be positioned at a predetermined distance (e.g., 2 micrometers) below the lower surface of spacer member 280. For example, tuning layer 244 can be placed under compressive stress due to the deposition of the additional layers described herein. Thus, the thicker the tuning layer 244, the greater the curvature of the actuation beam 240 toward the orifice 260 in its default position. In one exemplary embodiment, the tuning layer 244 is made of silicon dioxide.

[0107] The barrier layer 400 acts as a barrier to prevent the diffusion of material contained in the piezoelectric layer 414 into the tuning layer 244. If left unchecked, this migration would lead to a detrimental mixing effect between the constituent materials in the layers, adversely affecting performance. In various embodiments, the barrier layer 400 is made of, for example, zirconium dioxide. As shown, the first electrode portion 402 includes an adhesive layer 408 and a first electrode 410. The adhesive layer 408 facilitates the deposition of the first electrode 410 onto the barrier layer 400 and prevents material in the first electrode 410 from diffusing into other layers. In various embodiments, the adhesive layer 408 is constructed of titanium dioxide. The first electrode 410 may be made of platinum, gold, rubidium, or any other suitable material to provide a conductive path for supplying electrical signals to the actuation portion 242. In some embodiments, the first electrode portion 402 is only included in selected portions of the actuation beam 240. For example, the first electrode portion 402 may only be included near and / or within the electrical connection portion 294.

[0108] The actuating portion 242 can be formed of a single layer or multiple layers of any suitable piezoelectric material. In the example shown, the actuating portion includes a growth template layer 412 and a piezoelectric layer 414. The growth template layer 412 serves as a seed layer, facilitating the growth of the piezoelectric layer 414 with the desired texture (e.g., a {001} crystal structure and corresponding texture) to ensure maximum piezoelectric response. In some embodiments, the growth template layer 412 is made of lead titanate. The piezoelectric layer 414 can be made of any suitable material such as lead zirconate titanate (PZT).

[0109] The piezoelectric layer 414 can be deposited using any method, such as vacuum deposition or sol-gel deposition techniques. In some embodiments, the piezoelectric layer 414 may have a thickness ranging from approximately 1 to 6 micrometers (e.g., 1, 2, 3, 4, 5, or 6 micrometers, including end values) and is adapted to produce a deflection of approximately 10 micrometers at the end of the actuating beam 240 when an electrical signal is applied to the actuating beam 240. A deflection of 10 micrometers (e.g., causing the surface of the sealing member 290 to be slightly less than this distance from the valve seat 270) is sufficient to produce a droplet of the desired size at the orifice 260. In some embodiments, the piezoelectric layer 414 has a piezoelectric transverse coefficient (d31 value) of approximately 140 pm / V to 160 pm / V. This value allows the actuating beam 240 to produce sufficient deflection via an electrical signal provided to the first electrode portion 402 and the second electrode portion 404.

[0110] As shown in the figure, a second electrode portion 404 is disposed on the actuation portion 242. In various embodiments, the structure of the second electrode portion 404 is similar to that of the first electrode portion 402 described herein. Therefore, applying a voltage to the first electrode portion 402 and / or the second electrode portion 404 induces strain in the piezoelectric layer 414, thereby causing the entire actuation beam 240 to bend away from the orifice plate 250. By applying periodic control signals to the first and second electrodes, the periodic cycling of the actuation beam 240 generates droplet output from the orifice 260 at a desired frequency. Although Figure 7A The first electrode portion 402 and the second electrode portion 404 are shown overlapping each other, but in other locations, the first electrode portion 402 and the second electrode portion 404 may not overlap. This can limit or prevent electron leakage between the first electrode portion 402 and the second electrode portion 404, which could damage the piezoelectric layer 414 or cause an electrical short circuit.

[0111] In various embodiments, the electrodes contained in the first electrode portion 402 and the second electrode portion 404 are deposited in an unannealed state. Therefore, the electrodes are deposited in a substantially compressed state, which affects the overall curvature of the actuation beam 240 in its default position. The deposition mode of the piezoelectric layer 414 can affect the compressed state of the electrode. For example, in some cases where the piezoelectric layer 414 (e.g., via vapor deposition) is deposited and subsequently cured at a predetermined temperature (e.g., approximately 700 degrees Celsius), curing can cause the electrode 410 to anneal and be removed from its compressed state. This removal affects the overall stress balance in the actuation beam 240, which alters its default curvature. Therefore, it may be advantageous to use a low-temperature deposition process (e.g., a low-temperature sol-gel deposition process or a plasma-enhanced chemical vapor deposition process) for the piezoelectric layer 414 to prevent stress reversal in the electrode. In various embodiments, the second electrode portion 404 may be annealed at a higher temperature than the first electrode portion 402, for example, to generate predetermined tuning stresses in the tuning layer 244.

[0112] Figure 7A The material shown can extend substantially entirely through the length of the actuation beam 240. Thus, there is overlap between the electrode portions 402 and 404 and the reservoir formed via the micro-valve 230. In various embodiments, the fluid contained in the reservoir is conductive and / or corrosive to the materials forming the first electrode portions 402 and the second electrode portions 404. Therefore, it is preferable to isolate the electrode portions 402 and 404 from the reservoir to prevent the fluid contained in the reservoir from contacting the electrode portions 402 and 404.

[0113] In this respect, the passivation structure 406 is configured to perform this isolation. In the example shown, the passivation structure 406 includes a dielectric layer 416, an insulating layer 418, and a barrier layer 420. The barrier layer 420 may be made of silicon nitride, which acts as a diffusion barrier to water molecules and ions contained in the fluid, preventing corrosion of electrode portions 402 and 404. In some embodiments, the insulating layer 418 includes a silicon dioxide layer having compressive stress that substantially balances the tensile stress in the barrier layer 420. The dielectric layer 416 may be made of aluminum oxide to prevent oxidation of the additional layer included in the actuation beam 240. In some embodiments, an additional metal layer is disposed on the barrier layer 420. For example, the metal layer may be made of tantalum oxide or any other suitable chemically resistant metal to further enhance the protective properties of the passivation structure 406. In a particular embodiment, the barrier layer 420 may be formed of Teflon or parylene. In other embodiments, at least a portion of the actuation beam 240 (i.e., by...) Figure 7AThe structure formed by the layers shown may be covered or coated with a Teflon or parylene layer. Such an outer coating can prevent the formation of microcracks in the layers of the actuating beam 240. In other embodiments, the outer coating may include a metallic layer, such as a tantalum or palladium layer.

[0114] The addition of the passivation structure 406 significantly affects the default positioning of the actuation beam 240. This is because the passivation structure 406 deviates from the compressive neutral axis 422 of the actuation beam 240. As shown, the neutral axis 422 is within the inactive layer 246, meaning that the electrode portion 404 and the passivation structure 406 are furthest from it in the actuation beam 240. Therefore, the tensile or compressive stresses induced in such a layer will greatly affect the default curvature of the actuation beam 240. Thus, the thickness of the tuning layer 244 is selected based on the structure of the individual constituent layers of the passivation structure 406.

[0115] Figure 7B This is a front sectional view of an actuation beam 240 according to an exemplary embodiment and not drawn to scale, showing the arrangement of each layer included in the actuation beam 240. As shown, the actuation beam 240 includes an inactive layer 246, a tuning layer 244, and a blocking layer 400, as relative to... Figure 7A As described, the first electrode portion 402 includes an adhesive layer 408 (e.g., titanium dioxide) positioned on the barrier layer 400 and a conductive layer or electrode 410 (e.g., platinum, gold, rubidium, etc.) positioned on the adhesive layer. The first electrode portion 402 is configured to have a width smaller than the width of the barrier layer 400, such that the end of the electrode portion 402 in a direction perpendicular to the longitudinal axis of the actuation beam 240 is located inside the end of the barrier layer 400 in the same direction.

[0116] An actuating portion 242, comprising a seed layer 412 and a piezoelectric layer 414, is conformally disposed on the first electrode portion 402 to extend beyond the lateral end of the first electrode portion 402 and contact the barrier layer 400. In this manner, the piezoelectric layer completely surrounds or encapsulates at least the portion of the first electrode portion 402 that overlaps with or is close to the second electrode portion 404. The second electrode portion 404 comprises an adhesive layer 403 (e.g., titanium) and a conductive layer 405 (e.g., platinum, gold, rubidium, etc.). In some embodiments, the second electrode portion 404 may comprise only the conductive layer 405 disposed directly on the piezoelectric layer 414 (i.e., omitting the adhesive layer 403). Because the actuating portion 242 overlaps with and extends beyond the end of the first electrode portion 402, the actuating portion effectively electrically isolates the first electrode portion 402 from the second electrode portion 404, thereby preventing electron leakage and current migration that could be detrimental to the performance of the actuating beam 240.

[0117] The passivation structure 406 conformally coats the exposed portions of each of the other layers 246, 244, 400, 402, 242, and 404. However, the bottom surface of the inactive layer 246 may not be coated with the passivation structure 406. The passivation structure 406 may include a dielectric layer 416, an insulating layer 418, a barrier layer 420, and a top passivation layer 424. The barrier layer 420 may be made of silicon nitride, which acts as a diffusion barrier to water molecules and ions contained in the fluid to prevent corrosion of the electrode portions 402 and 404. However, once deposited on the remaining layers, the silicon nitride is typically under tensile stress. The insulating layer 418 is configured to counteract this tensile stress. For example, in some embodiments, the insulating layer 418 includes a silicon dioxide layer having compressive stress that substantially balances the tensile stress in the barrier layer 420. In various embodiments, the barrier layer 420 may be positioned beneath the insulating layer 418. The dielectric layer 416 may be composed of aluminum oxide, titanium oxide, zirconium oxide, or zinc oxide to prevent oxidation of the additional layers included in the actuation beam 240. Therefore, the passivation structure 406 serves to prevent both corrosion and oxidation in the actuation beam 240—two major sources of defects caused by the presence of fluid—and thus ensures the long-term performance of the microvalve 230. Furthermore, a top passivation layer 424 is disposed on the barrier layer 420 and may comprise a Teflon or parylene layer. This outer coating prevents the formation of microcracks in the layers of the actuation beam 240 and also protects the underlying layers from plasma discharges (e.g., buried layers may be exposed to such plasma discharges during subsequent manufacturing operations). In certain embodiments, the top passivation layer 424 may comprise a metal layer, such as a tantalum or palladium layer. In some embodiments, an additional metal layer is disposed on the barrier layer 420. For example, the metal layer may be composed of tantalum oxide or any other suitable chemically resistant metal to further enhance the protective properties of the passivation structure 406.

[0118] Compared to Figures 8 to 12 The described injection assembly, micro-valve, and related components can be implemented according to any of the foregoing embodiments. Now refer to... Figure 8 A cross-sectional view of a sealing structure 800 of a miniature valve according to an exemplary embodiment is shown. For example, the sealing structure 800 may be relative to... Figure 6 An example of the described sealing structure 500 is shown. As illustrated, the actuating beam 802 includes a cantilever portion 804. The cantilever portion 804 extends from a base portion disposed on a spacer member. The spacer member may be disposed on an orifice plate 812 including an orifice 814. The cantilever portion 804 extends from the base portion toward the orifice 814 such that the overlapping portion 806 of the cantilever portion overlaps with the orifice 814.

[0119] The sealing structure 800 includes a sealing member 808 disposed at an overlapping portion 806 and a valve seat 810 disposed on an orifice plate 812. The sealing member 808 extends toward an orifice 814 such that an orifice-facing surface 816 contacts an upper surface 822 of the valve seat 810. The valve seat 810 surrounds the orifice 814 and defines an opening 818. In the example shown, the opening 818 is aligned with the orifice 814. In other words, the opening 818 and the orifice 814 define a fluid outlet having a substantially smooth defining surface. In various embodiments, the valve seat 810 is formed of a compliant material such as SU-8. In other embodiments, the valve seat 810 may be formed of silicon. As described herein, the actuating beam 802 may be configured such that it has a slight bend or offset toward the orifice 814 in its default position, such that the orifice-facing surface 816 is pressed into the valve seat 810 to form a seal that isolates the orifice 814 from a volume 820 disposed near the actuating beam 802.

[0120] In the example shown, orifice 814 is cylindrical. In other embodiments, orifice 814 may have any other suitable shape (e.g., star-shaped, square, rectangular, polygonal, elliptical, etc.). Valve seat 810 is substantially annular and has an inner diameter equal to or substantially equal to the diameter of orifice 814. Valve seat 810 has an outer diameter greater than its inner diameter. Sealing member 808 is formed as a pillar or column with a diameter between the inner and outer diameters of valve seat 810. In the example shown, the diameter of sealing member 808 is closer to the inner diameter of valve seat 810 than its outer diameter. The size of sealing member 808 contributes to the resonant frequency of actuation beam 802 (e.g., by affecting its overall weight and thus the overall piezoelectric response of actuation beam 802). Therefore, in some embodiments, when the size of valve seat 810 is kept fixed, the diameter of sealing member 808 is closer to its inner diameter to produce the desired resonant frequency. However, it should be understood that in various alternative embodiments, the thickness of the valve seat 810 (i.e., the difference between the inner and outer diameters of the valve seat 810) can be varied in the radial direction, such that the overall positioning of the outer edge of the sealing member 808 relative to the valve seat 810 can be changed.

[0121] Now for reference Figure 9 A cross-sectional view of a sealing structure 900 according to an exemplary embodiment is shown. The sealing structure 900 is relative to... Figure 8 The described sealing structure 800 has common features. Thus, Figure 9 Common reference numerals are used to indicate the inclusion of these similar parts.

[0122] As shown in the figure, in the sealing structure 900, a coating 902 is disposed on the upper surface 822 of the valve seat 810. In various embodiments, the coating 902 is a hydrophobic elastic material, such as... Teflon, polydimethylsiloxane (PDMS), or any other suitable hydrophobic or oleophilic material. The hydrophobicity of coating 902 facilitates the dispersion of water droplets on valve seat 810, preventing particulate matter from coalescing on upper surface 822. Thus, coating 902 promotes the long-term durability of sealing structure 900. Additionally, coating 902 can increase the flexibility or complexity of valve seat 810 to facilitate the formation of a seal at the interface between orifice-facing surface 816 and upper surface 822. In some embodiments, coating 902 may be formed of a compliant material such as gold.

[0123] Now for reference Figure 10 A cross-sectional view of a sealing structure 1000 according to an exemplary embodiment is shown. The sealing structure 1000 is relative to... Figure 8 The described sealing structure 800 has common features. Thus, Figure 10 Common reference numerals are used to indicate the inclusion of these similar parts. For example... Figure 10 As shown, in the sealing structure 1000, a coating 1002 is disposed around the inner surface of the fluid outlet defined by the orifice 814 and the opening 818. In some embodiments, the coating 1002 may be made of a hydrophobic material such as The coating 1002 is made of Teflon, PDMS, or any other suitable hydrophobic or oleophilic material. The hydrophobicity of the coating 1002 facilitates the formation and travel of droplets within the orifice 814 when the actuating beam 802 is actuated (e.g., due to an electrical signal being applied to it).

[0124] In some implementations, the sealing structure may include, relative to Figure 9 and Figure 10 The combination of coatings 902 and 1002 is described. In other words, the sealing structure may include both a coating lining the inner surface of the fluid outlet and a coating on the upper surface 822. Advantageously, this embodiment provides hydrophobicity within both the fluid outlet and the upper surface 822.

[0125] Now for reference Figure 11 and Figure 12 A cross-sectional view of sealing structures 1100 and 1200 according to an exemplary embodiment is shown. Sealing structures 1100 and 1200 are relative to... Figure 8 The described sealing structure 800 shares common components and includes the same reference numerals to indicate the combination of these similar components.

[0126] like Figure 11 As shown, the sealing structure 1100 differs from the sealing structure 800 in that it includes a sealing member 1102, which has a greater sealing effect than the sealing structure 800. Figure 8The described sealing member 808 has a larger diameter. Thus, the side surface 1104 of the sealing member 1102 is closer to the outer diameter of the valve seat 810 than its inner diameter. This arrangement provides a larger surface area for contacting the upper surface 822 of the valve seat 810 to form the isolation seal described herein. However, it should be understood that the larger size of the sealing member 1102 can contribute to the resonant frequency of the actuating beam 802 and other operational aspects of any associated injection assembly (e.g., droplet size, operating frequency, etc.).

[0127] like Figure 12 As shown, the sealing structure 1200 differs from the sealing structure 1100 in that it includes a sealing member 1202 having a diameter that is still larger than that of the sealing member 1102. The outer surface 1204 of the sealing structure 1200 is substantially aligned with the outer diameter of the valve seat 810. In other words, the diameter of the sealing member 1202 is substantially equal to the outer diameter of the valve seat 810 (e.g., within +10% of the outer diameter). This arrangement provides an even larger surface area for forming an isolation seal, but it should be understood that such a modification may affect the performance of any combined injection assembly in other ways (e.g., operating frequency). In other embodiments, the diameter of the sealing member 1202 may be larger than the outer diameter of the valve seat 810. In some embodiments, silicon black may be formed on the orifice-facing surface of the sealing member 1102 or 1202, which may enhance the fluid seal from the sealing member to the valve seat 810.

[0128] Now for reference Figure 13 The figure shows a cross-sectional view of a sealing structure 1300 of a miniature valve according to an exemplary embodiment. As shown, a cantilever portion 1304 of an actuation beam 1302 extends toward an orifice 1318 in an orifice plate 1316. An overlapping portion 1306 of the cantilever portion 1304 overlaps with the orifice 1318. The sealing structure 1300 includes a sealing member 1308 disposed at the overlapping portion 1306 and extending toward the orifice 1318. In various embodiments, the sealing member 1308 is shaped to correspond to the orifice 1318. For example, in various embodiments, both the sealing member 1308 and the orifice 1318 are substantially cylindrical, and the orifice 1318 has a diameter smaller than the diameter of the sealing member 1308.

[0129] The sealing structure 1300 also includes a stop 1310 disposed on the orifice-facing surface 1322 of the sealing member 1308. The stop 1310 may be made of a compliant material such as SU-8, PDMS, or any other suitable material. As shown, the stop 1310 includes a narrow portion 1312 attached to the orifice-facing surface 1322 and a wide portion 1314 extending from the narrow portion 1312. The narrow portion 1312 and the wide portion 1314 may be substantially cylindrical in shape, such that the stop 1310 forms a substantially cap-shaped structure. In various embodiments, the wide portion 1314 has a cross-sectional area larger than that of the narrow portion 1312.

[0130] The surface 1324 of the stop 1310 facing the orifice includes a protrusion 1326 formed in a manner corresponding to the orifice 1318. The protrusion 1326 is aligned with the orifice 1318 such that it fits within the orifice 1318 to ensure a seal is formed when the surface 1324 facing the orifice contacts the orifice plate 1316. Figure 13 In the diagram, the stop 1310 is shown comprising a portion 1320 disposed on the surface 1322 facing the orifice and a remaining portion 1328 disposed on the orifice plate 1316. The stop 1310 includes the portion 1320 and the remaining portion 1328 at an intermediate stage of its construction. In various embodiments, after the construction of the stop 1310 is completed, the stop 1310 is an integral body continuously extending between the surfaces 1322 and 1324 facing the orifice.

[0131] Similar to relative Figures 5A to 5B The actuating beam 240 and actuating beam 1302 can be configured with a default curvature or offset such that the orifice-facing surface 1324 contacts the orifice plate 1316 and the protrusion 1326 engages within the orifice 1318 to form a seal at the interface between the stop 1310 and the orifice plate 1316. In other words, due to the direct contact between the stop 1310 and the orifice plate 1316, the actuating beam 1302 can apply a downward force to produce a tight seal. The protrusion 1326 ensures minimal clearance at the interface to form a tight seal.

[0132] Now for reference Figure 14A cross-sectional view of a sealing structure 1500 of a miniature valve according to an exemplary embodiment is shown. As shown, a cantilever portion 1504 of an actuation beam 1502 extends toward an orifice 1516 of an orifice plate 1514. An overlapping portion 1506 of the cantilever portion 1504 overlaps with the orifice 1516. The sealing structure 1500 includes a sealing member 1508 disposed at the overlapping portion 1506 and extending toward the orifice 1516. In various embodiments, the sealing member 1508 is shaped to correspond to the orifice 1516. For example, in various embodiments, both the sealing member 1508 and the orifice 1516 are substantially cylindrical, and the orifice 1516 has a diameter smaller than the diameter of the sealing member 1508.

[0133] The sealing structure 1500 also includes a valve seat 1512. The valve seat 1512 surrounds an orifice 1516 and defines an opening aligned with the orifice 1516 to define a fluid outlet. In various embodiments, the valve seat 810 is formed of a compliant material such as SU-8. In other embodiments, the valve seat 810 is formed of a non-compliant material such as glass or silicon. As shown, a sealing blade or protrusion 1510 extends from the orifice-facing surface 1518 of the sealing member 1508. The sealing blade 1510 may be shaped in a manner corresponding to the periphery of the sealing member 1508. In some embodiments, the sealing blade 1510 is substantially annular and has an inner diameter and an outer diameter falling between the inner and outer diameters of the valve seat 1512. When the actuating beam 1502 is in the default position, the sealing blade 1510 extends toward the upper surface 1520 of the valve seat 1512 and contacts the valve seat 1512. The sealing blade 1510 provides a focal point for the downward force provided by the actuating beam 1502, resulting in a tight seal at the interface between the tip of the sealing blade 1510 and the valve seat 1512. Figure 14 As shown, the sealing blade 1510 may have a blade tip with a suitable tip radius (e.g., in the range of 0.1 micrometers to 1.0 micrometers). In other embodiments, the sealing blade 1510, or any other sealing blade as defined herein, may have a flat or rounded tip.

[0134] Now for reference Figure 15 A cross-sectional view of a sealing structure 1600 according to an exemplary embodiment is shown. The sealing structure 1600 includes a sealing structure 1600 relative to... Figure 14 The described sealing structure 1500 is a similar component, and includes the same reference numerals to indicate the assembly of these similar components. Sealing structure 1600 is related to... Figure 14The difference in the described sealing structure 1500 is that the sealing structure 1600 includes an additional sealing blade 1602. The additional sealing blade 1602 may be concentric with and surround the sealing blade 1510, such that the sealing blades 1510 and 1602 form a concentric ring that contacts the upper surface 1520. In other embodiments, the sealing blades 1510 and 1602 may not be concentric with the orifice or may have a non-circular cross-section (e.g., oval, elliptical, polygonal, asymmetrical, etc.).

[0135] The additional sealing blade 1602 increases the contact area between the sealing member 1508 and the valve seat 1512. This increased contact area not only improves the quality of the seal formed at the interface between the valve seat 1512 and the sealing blades 1510 and 1602, but also makes the sealing structure 1600 more effective at handling particulate matter that may remain between the sealing member 1508 and the valve seat 1512. Furthermore, the additional sealing blade 1602 improves the durability of the sealing structure 1600 because it serves as a backup point of contact with the valve seat 1512. In other words, if the sealing blade 1510 is damaged at a specific circumferential point, the additional sealing blade 1602 will still form a seal at that point, allowing the sealing structure 1600 to remain operational.

[0136] Figure 16 This is a bottom view of a sealing member 1614 including an actuating beam (e.g., any actuating beam defined herein) of a sealing structure 1650 according to an exemplary embodiment. The sealing member 1614 has as shown... Figure 16The cross-section shown is substantially cylindrical. In other embodiments, the sealing member 1614 may have any other suitable cross-section, such as square, rectangular, star-shaped ellipse, etc. The sealing structure 1650 includes a first set of sealing blades 1610a that extend axially from and are concentrically positioned on the orifice-facing surface 1618 of the sealing member 1614. A first gap 1612a may be provided between each adjacent first sealing blade 1611a of the first set of sealing blades 1610a, such that each sealing blade of the first set of sealing blades 1610a resembles a segment of a first circle (e.g., an arc segment). A second set of sealing blades 1610b may be concentrically positioned inside the first set of sealing blades 1610a, wherein a second gap 1612b is provided between each adjacent second sealing blade 1611b of the second set of sealing blades 1610b, as described relative to the first set of sealing blades 1610a. Similarly, the third set of sealing blades 1610c can be concentrically positioned inside the second set of sealing blades 1610b, wherein each adjacent third sealing blade 1611c of the third set of sealing blades 1610b has a third gap 1612c, as described relative to the first set of sealing blades 1610a and the second set of sealing blades 1610b. In other embodiments, even more sets of sealing blades can be concentrically positioned on the orifice sealing member surface 1618. The gaps 1612a / b / c of ​​the sets of sealing blades 1610a / b / c can be staggered relative to each other, i.e., non-concentrically overlapping. This arrangement provides a better seal and traps any particles (e.g., contaminants, photoresist particles, etc.) between the sets of sealing blades 1610a / b / c.

[0137] Now for reference Figure 17 A flowchart illustrating a method 1700 for constructing a sealing structure for a microvalve according to an exemplary embodiment is shown. The executable method 1700 is used to construct a sealing structure relative to... Figure 14 , Figure 15 and Figure 16 The sealing structures 1500 and 1600 are described. Depending on the implementation, method 1700 may include fewer or more operations.

[0138] In operation 1702, an orifice plate including an orifice is provided. For example, in some embodiments, the orifice plate is formed from an SOI wafer (e.g., a portion of the wafer may be removed to form the orifice). In some embodiments, a valve seat is disposed at the orifice after the orifice is formed. The valve seat may surround the orifice and define an opening aligned with the orifice to form a fluid outlet. In operation 1704, an actuating beam including a sealing member having a surface facing the orifice is provided. For example, as described herein, the actuating beam may be formed by etching a portion of a dual SOI wafer, such that the spacer member and the sealing member are formed in a single manufacturing step. The surface of the sealing member may form a surface facing the orifice.

[0139] In operation 1706, an etch-resistant material is deposited on the surface facing the orifice. The etch-resistant material (e.g., silicon dioxide or silicon nitride) has a different chemical composition than the sealing member of the actuating beam, causing the etch-resistant material to slow down the chemical process (e.g., etching) that removes portions of the sealing member. In operation 1708, portions of the etch-resistant material are etched such that the remaining portion of the etch-resistant material on the orifice-facing surface corresponds to the position and shape of a sealing blade (e.g., one or more sealing blades). For example, the remaining portion of the etch-resistant material covers only a portion of the sealing member surface. In some embodiments, the etch-resistant material may be substantially annular to create annular sealing blades. In various embodiments, the etch-resistant material comprises silicon dioxide. Thus, the etch-resistant material layer can be deposited via chemical vapor deposition or any other suitable method. The etch-resistant material layer can then be patterned using any suitable method (e.g., using an etch mask, photolithography, etc.). In some embodiments, multiple segments of the etch-resistant material are formed to facilitate the formation of multiple sealing blades. In other embodiments, a release layer (e.g., a photoresist) may be deposited on the orifice-facing surface and photolithographically patterned to create one or more shapes therein corresponding to the size and position of the sealing blade. An etch-resistant material may be deposited on the release layer such that the etch-resistant material contacts the orifice sealing member surface at the patterned portions, but is disposed on the release layer at all other locations. The release layer can then be removed such that any portion of the etch-resistant material disposed on the release layer is subsequently removed, leaving patterned etch-resistant material corresponding to the position and shape of the sealing blade disposed on the orifice-facing surface.

[0140] In operation 1710, the sealing member is isotropically etched for a first predetermined time. The isotropic etching (e.g., wet etching) can be configured to etch the portion of the sealing member beneath the etch-resistant material, for example, to define the tip of the sealing blade. In operation 1712, the sealing member is anisotropically etched (e.g., deep reactive ion etching, such as the Bosch process) for a second predetermined time to remove a portion of the sealing member, such that the remaining unetched portion forms the sealing blade before the actuating beam is attached to the orifice plate. The second predetermined time can be varied to define the height of the sealing blade. For example, the etch-resistant material can delay or completely prevent etching of the portion of the sealing member covered by the etch-resistant material segment. Thus, the uncovered portion of the sealing member will be removed at a faster rate than the portion covered by the etch-resistant material segment. Therefore, a protrusion is formed beneath the etch-resistant material to construct the sealing blade. The etching can occur for a time length selected based on the desired length of the sealing blade. For example, the desired length can be selected based on the estimated durability of the resulting sealing blade. The estimated durability can depend at least in part on other dimensions of the sealing blade (e.g., radial thickness). In an alternative embodiment, instead of providing an etch-resistant material and applying an etchant to the surface of the sealing member, alternative means can be used to form the sealing blade. For example, any suitable forming method can be used to form the sealing blade.

[0141] In some embodiments, in operation 1714, an etch-resistant material may be removed. For example, the etch-resistant material (e.g., silicon dioxide) may be removed via wet etching (e.g., buffered hydrofluoric acid etching) or dry etching processes. In some embodiments, method 1700 may further include anisotropically etching a portion of the actuation beam to form a sealing member, releasing the actuation beam from the substrate to form a cantilevered portion of the actuation beam. In operation 1716, after the sealing blade is formed on the surface of the sealing member, the actuation beam is attached to an orifice plate such that the surface of the sealing member is aligned with a valve seat disposed on the orifice plate. For example, a spacer member attached to the actuation beam may be positioned and attached to the orifice plate such that the surface of the sealing member is aligned with the orifice. The alignment of the sealing member surface with the orifice such that when the actuation beam is in the default position, the sealing blade is positioned to contact the upper surface of the valve seat.

[0142] Now for reference Figure 18The figure shows a cross-sectional view of a sealing structure 1800 of a miniature valve according to an exemplary embodiment. As shown, a cantilever portion 1804 of an actuation beam 1802 extends toward an orifice 1816 of an orifice plate 1814. An overlapping portion 1806 of the cantilever portion 1804 overlaps with the orifice 1816. The sealing structure 1800 includes a sealing member 1808 disposed at the overlapping portion 1806 and extending toward the orifice 1816. In various embodiments, the sealing member 1808 is shaped to correspond to the orifice 1816. For example, in various embodiments, both the sealing member 1808 and the orifice 1816 are substantially cylindrical, and the orifice 1816 has a diameter smaller than the diameter of the sealing member 1808.

[0143] As shown, the sealing member 1808 includes an orifice-facing surface 1818 and a side surface 1822. A portion of the sealing member 1808 is removed at the corner between the orifice-facing surface 1818 and the side surface 1822. In various embodiments, the removed portion of the sealing member 1808 extends circumferentially around the entire sealing member 1808. Thus, the sealing member includes a narrow portion 1824 at its end. The narrow portion may have a diameter approximately equal to the diameter of the orifice 1816. A sealing flange 1810 extends radially outward from the narrow portion 1824 at the orifice-facing surface 1818. As shown, when the actuating beam 1802 is in the default position, the sealing flange 1810 contacts the upper surface 1820 of the valve seat 1812 to form a seal at the interface between the sealing member 1808 and the valve seat 1812. The sealing flange 1810 provides a compressible medium through which a tight seal can be formed. In other embodiments, a sealing flap may be provided on the inner edge of the valve seat 1812. In such embodiments, the narrow portion 1824 of the sealing member 1808 may be configured to at least partially enter the opening defined in the valve seat 1812 and engage the sealing flap positioned on the inner edge of the valve seat 1812 to form a fluid tight seal.

[0144] Now for reference Figure 19 A flowchart of a method 1900 for constructing a sealing structure for a microvalve according to an exemplary embodiment is shown. Method 1900 can be performed to construct a sealing structure relative to... Figure 18 The sealing structure 1800 is described. Depending on the implementation, method 1900 may include fewer or more operations.

[0145] In operation 1902, an orifice plate including an aperture is provided. For example, in some embodiments, the orifice plate is formed from an SOI wafer (e.g., a portion of the wafer may be removed to form the aperture). In some embodiments, a valve seat is disposed at the aperture after the aperture is formed. The valve seat may surround the aperture and define an opening aligned with the aperture to form a fluid outlet. In operation 1904, an actuating beam including a sealing member having a surface facing the aperture and side surfaces is provided. For example, as described herein, the actuating beam may be formed by etching a portion of a dual SOI wafer, such that the spacer member and the sealing member are formed in a single manufacturing step. The sealing member may be substantially cylindrical. The surface facing the aperture may include an end face of the sealing member, and the side surfaces may include circular surfaces of the sealing member.

[0146] In operation 1906, an etch-resistant material is deposited onto the entire surface facing the orifice. The etch-resistant material (e.g., silicon dioxide or silicon nitride) has a different chemical composition than the sealing member of the actuating beam, causing the etch-resistant material to slow down the chemical process (e.g., etching) for removing the sealing member. In various embodiments, the etch-resistant material comprises silicon dioxide. Thus, the etch-resistant material layer can be deposited via chemical vapor deposition or any other suitable method.

[0147] In operation 1908, the sealing member is selectively etched (e.g., with an etchant such as TMAH or KOH) to remove portions of the sealing member located beneath the etch-resistant material on the side surfaces of the sealing member, such that the etch-resistant material extends over the removed portion of the sealing member to form a sealing flap. For example, an etchant may be applied to the end of the sealing member near the surface of the sealing member, such that portions of the sealing member not covered by the etch-resistant material (e.g., at corners separating the surface of the sealing member from the side surfaces) are selectively etched and removed. The remaining segments of the etch-resistant material can then form the sealing flap. Thus, the sealing flap can have little or no material disposed on either side and form a compliant layer that can be pressed against various surfaces to form a seal. In other embodiments, the etch-resistant material can be removed after operation 1908, and separately manufactured sealing flaps formed of a compliant material (e.g., PDMS) can be positioned on the surface facing the orifice.

[0148] In operation 1910, the actuating beam is attached to the orifice plate such that a portion of the sealing flange extends above the orifice. For example, the spacer member attached to the actuating beam can be positioned and attached to the orifice plate such that the surface of the sealing member is aligned with the orifice. In some embodiments, the sealing member is substantially centered relative to the orifice. Therefore, the sealing flange can extend radially along the inner diameter of the valve seat, such that a seal can be formed between the valve seat and the sealing flange when the actuating beam is in the default position.

[0149] Now for reference Figure 20 A flowchart of a method 2000 for constructing a microvalve according to an exemplary embodiment is shown. Method 2000 can be performed to construct any microvalve described herein. Depending on the implementation, method 2000 may include fewer or more operations.

[0150] In operation 2002, an orifice plate including an aperture is provided. For example, in some embodiments, the orifice plate is formed from an SOI wafer (e.g., a portion of the wafer may be removed to form the aperture). In some embodiments, a valve seat is disposed at the aperture after the aperture is formed. The valve seat may surround the aperture and define an opening aligned with the aperture to form a fluid outlet. In operation 2004, an actuating beam including a sealing member having a surface facing the aperture and side surfaces is provided. For example, as described herein, the actuating beam may be formed by etching a portion of a dual SOI wafer, such that the spacer member and the sealing member are formed in a single manufacturing step. The sealing member may be substantially cylindrical. The surface facing the aperture may include an end face of the sealing member.

[0151] In operation 2006, a portion of the sealing structure is formed on at least one of the sealing member and the orifice plate. For example, in some embodiments, this portion of the sealing structure member includes a valve seat formed on the surface of the orifice plate. The valve seat may surround the orifice plate and define an opening aligned with the orifice to form a fluid outlet. The valve seat may be constructed of a compliant material such as SU-8 and may be deposited using any suitable method (e.g., spin coating or spray coating).

[0152] In some embodiments, this portion of the sealing structure is formed on the orifice-facing surface of the sealing member. This may involve relative to... Figure 14 , Figure 17 and Figure 18 The described operations are used to construct a stop, at least one sealing blade, or sealing fin. It should be understood that any combination of these structures can be used to construct this portion of the sealing member. In some embodiments, multiple portions of the sealing structure can be formed. For example, in addition to forming components (e.g., compliant structures, sealing blades, and / or sealing fins) on the sealing member surface or valve seat of the sealing member, the valve seat can be formed on an orifice plate. In some embodiments, portions of the sealing structure can be formed on the side surface of the sealing structure (e.g., such as relative to...). Figure 18 The described side surface 1822). For example, in one embodiment, the sealing member is adapted to fit within a fluid outlet formed by a valve seat and an orifice plate, and a component of the sealing structure extends radially outward from the side surface. This component can contact the upper surface of the valve seat to form a seal that isolates the orifice from the volume of the adjacent actuating beam.

[0153] In operation 2008, the actuating beam is attached to the orifice plate such that the sealing member overlaps with the orifice, and the sealing structure forms a seal that separates the orifice from the volume of the adjacent actuating beam. For example, the spacer member attached to the actuating beam can be positioned and attached to the orifice plate such that the surface facing the orifice is aligned with the orifice. In some embodiments, the sealing member is substantially centered relative to the orifice. Therefore, when the actuating beam is in the default position, a portion of the sealing member formed in operation 2006 may contact the orifice plate or a valve seat thereon.

[0154] Now for reference Figure 21 A cross-sectional view of a sealing member 2100 of a miniature valve according to an exemplary embodiment is shown. The sealing member 2100 may be contained within a... Figure 8 An exemplary embodiment of the sealing member 808 in the described sealing structure 800 or any sealing structure described herein. As shown, the sealing member 2100 is substantially cylindrical in shape and has a diameter 2102. The diameter 2102 can be selected based on the size of the orifice in the orifice plate. For example, in some embodiments, the diameter 2102 is approximately 150% of the orifice diameter (e.g., the orifice may have a diameter of 60 micrometers, while the diameter 2102 may be 90 micrometers).

[0155] Now for reference Figure 22 A cross-sectional view of a valve seat 2200 of a miniature valve according to an exemplary embodiment is shown. The valve seat 2200 may be contained within a valve seat relative to... Figure 8 An exemplary embodiment of the valve seat 810 in the described sealing structure 800 or any sealing structure described herein. As shown, the valve seat 2200 is annular in shape and includes an inner diameter 2202 and an outer diameter 2204. The inner diameter 2202 and the outer diameter 2204 may define the range in which the diameter of the sealing member is contained. For example, relative to... Figure 21 In embodiments where the sealing member 2100 is used in conjunction with the valve seat 2200, the diameter 2102 may be larger than the inner diameter 2202. In some embodiments, the diameter 2102 is between the inner diameter 2202 and the outer diameter 2204. In some embodiments, the diameter 2102 is equal to the outer diameter 2204, and the miniature valve is configured such that the sealing member 2100 is substantially aligned with the valve seat 2200, such that the outer surface of the sealing member is substantially flush with the valve seat 2200. In some embodiments, the diameter 2102 is larger than the outer diameter 2204, such that the outer edge of the sealing member 2100 hangs over the valve seat in the assembled miniature valve.

[0156] Now for reference Figure 23A cross-sectional view of a sealing structure 2300 of a miniature valve according to an exemplary embodiment is shown. As shown, a cantilever portion 2304 of the actuation beam 2302 extends toward an orifice 2316 of the orifice plate 2314. An overlapping portion 2306 of the cantilever portion 2304 overlaps with the orifice 2316. The sealing structure 2300 includes a sealing member 2308 disposed at the overlapping portion 2306 and extending toward the orifice 2316. In various embodiments, the sealing member 2308 is shaped to correspond to the orifice 2316. For example, in various embodiments, both the sealing member 2308 and the orifice 2316 are substantially cylindrical, and the orifice 2316 has a diameter smaller than the diameter of the sealing member 2308.

[0157] The sealing structure 2300 also includes a valve seat 2312. The valve seat 2312 surrounds the orifice 2316 and defines an opening aligned with the orifice 2316 to define a fluid outlet. In various embodiments, the valve seat 2312 is formed of a compliant material such as a negative photoresist (e.g., SU-8). As shown, a plurality of sealing blades or protrusions 2310 extend from the orifice-facing surface 2318 of the sealing member 2308. The sealing blades 2310 may be shaped in a manner corresponding to the periphery of the sealing member 2308 (e.g., concentrically arranged on the orifice-facing surface 2318). In some embodiments, the sealing blades 2310 are substantially annular and have an inner diameter and an outer diameter falling between the inner and outer diameters of the valve seat 2312.

[0158] like Figure 23As shown, a sealing layer 2320 may be disposed on a valve seat 2312. The sealing layer 2320 may comprise, for example, a metal layer (e.g., gold or platinum) or any other suitable layer. In various embodiments, a plurality of notches 2322 may be formed on the sealing layer 2320. The plurality of notches 2322 may be formed, for example, via an etching process and are positioned corresponding to the locations of a plurality of sealing blades 2310. In a particular embodiment, the plurality of notches 2322 are formed by cold forging by repeatedly striking the plurality of sealing blades 2310 against the sealing layer 2320 (e.g., periodically applying an electrical signal to the actuation beam 2302). When the actuation beam 2302 is in the default position, the sealing blades 2310 extend toward the sealing layer 2320 and contact the base of the corresponding notch 2322. The spacing between adjacent sealing blades 2310 and the distance between the orifice-facing surface 2318 and the orifice plate 2314 can be configured to push small particles P (e.g., dust, photoresist debris, etc.) away from the seal formed between the sealing blades 2310 and the valve seat 2312, for example, toward the orifice 2316 and outside the orifice. Furthermore, the engagement of multiple sealing blades 2310 with corresponding notches 2322 can facilitate a better fluid tightness seal between the sealing member 2308 and the valve seat 2312. In a particular embodiment, a filter (e.g., 5 micrometers, 10 micrometers, 15 micrometers, or 20 micrometers) can be positioned in a fluid manifold upstream of a diaphragm provided in a jet assembly including a microvalve with a sealing structure 2300 to filter dust or other particulate matter from the fluid.

[0159] In a particular embodiment, the valve seat disposed on the orifice plate may be formed of silicon, and the sealing layer may be formed of silicon dioxide or silicon nitride. For example, Figure 24 A process 2400 that can be used to provide a sealing layer 2420 on a valve seat 2412 is illustrated. At operation 1, the silicon valve seat 2412 is disposed on an orifice plate 2414 having an orifice 2416 defined therein. The orifice plate 2414 may include any orifice plate as defined herein. The valve seat 2412 is formed of silicon and may be deposited thereon via, for example, a silicon epitaxial growth process followed by photolithographic patterning and etching, or may comprise a silicon wafer (e.g., a silicon ring) positioned around the orifice 2416. A sealing layer 2420 (e.g., a silicon dioxide or silicon nitride sealing layer) is disposed on the valve seat 2412. The sealing layer 2420 may be deposited using a physical deposition process (e.g., chemical vapor deposition or plasma-enhanced vapor deposition).

[0160] At operation 2, a plurality of openings 2422 are defined at predetermined locations in the silicon dioxide sealing layer 2420, such that the sealing layer 2420 forms a plurality of silicon dioxide or silicon nitride rings 2421. The plurality of openings 2422 can be formed via photolithography and etching (e.g., using buffered hydrofluoric acid or dry plasma etching processes) to expose the surface of the silicon valve seat 2412 at predetermined locations. At operation 3, the silicon valve seat 2412 can be selectively etched at the plurality of openings 2422 using an etchant that selectively etches silicon (e.g., using potassium hydroxide or tetramethylammonium oxide etchant, dry plasma etching process) to form a plurality of recesses 2424 in the silicon valve seat 2412. In some embodiments, the plurality of recesses 2424 may correspond to a plurality of sealing blades (e.g., sealing blades 2310) positioned on the orifice-facing surface of an actuation beam (e.g., actuation beam 2302). In other embodiments, the plurality of rings 2421 may serve as sealing blades, allowing the plurality of sealing blades to be expelled from the actuation beam. It should be understood that although process 2400 describes a silicon valve seat 2412 having a silicon dioxide or silicon nitride sealing layer 2420 thereon, in other embodiments, the valve seat 2412 and / or sealing layer 2420 may be formed of any other suitable material, such as a negative photoresist (e.g., SU-8, polymethyl methacrylate, etc.), PDMS, silicone rubber, etc., and may be formed or mechanically positioned thereon using photolithography and etching processes (e.g., any combination of processes described herein). Furthermore, in other embodiments, the operation of process 2400 may be used to form a sealing member having multiple rings at the tip of an actuating beam.

[0161] Now for reference Figure 25 A cross-sectional view of a microvalve 2530, which may be included in an injection assembly (e.g., injection assemblies 100, 200, 200b) according to an example embodiment, is shown. An inlet fluid manifold 2510 is coupled to the microvalve 2530. As shown, the inlet fluid manifold 2510 and the microvalve 2530 may define a reservoir 3000 configured to contain (e.g., via carriers 202, 202b) a volume of pressurized fluid received from an external fluid supply device. In various embodiments, the pressurized fluid contained in the reservoir 3000 is a combination of ink and liquid adjunct fluid.

[0162] In various embodiments, the inlet fluid manifold 2510 can be pre-formed before it is attached to the microvalve. In some embodiments, the inlet fluid manifold 2510 can be formed from a glass body having any suitable thickness (e.g., about 500 micrometers). In other embodiments, the inlet fluid manifold 2510 can be formed from silicon. In some embodiments, the inlet fluid manifold 2510 is attached to the top surface of the actuation beam 2540 (e.g., any of the actuation beams 240, 240b previously described herein) at the base portion 2542 of the actuation beam 2540 located on and fixed to the spacer member 2580 via a first adhesive structure 2548. The first adhesive structure 2548 may include structures similar to those referenced in the document. Figure 4A or Figure 4B The aforementioned multiple adhesive rings. The adhesive may include SU-8 or any other suitable adhesive and may be applied to the bottom surface of the inlet fluid manifold 2510 and / or the top surface of the actuation beam 2540. In other embodiments, the first adhesive structure 2548 may be formed of silicon or glass and is coupled to the actuation beam 2540 via glass powder, solder, adhesive, fusion bonding, eutectic bonding, or adhesion. Electrodes 2504 are disposed in through-holes defined in the base portion of the actuation beam 2540 and are electrically coupled to a piezoelectric layer defined in the actuation beam 2540. As previously described herein, the through-holes may correspond to channels or openings 2512 defined in the inlet fluid manifold 2510 and may be filled with a sealant.

[0163] The miniature valve 2530 also includes an orifice plate 2550 attached to the actuating beam 2540 via a spacer member 2580. For example... Figure 25 As shown, the second adhesive structure 2556 may be similar to the first adhesive structure 2548 and includes multiple rings or loops of adhesive material (e.g., SU-8). In some embodiments, multiple slots or keys 2582 may be defined in the bottom surface of the spacer member 2580 facing the perforated plate 2550. The adhesive included in the adhesive structure 2556 may penetrate the slots 2582 to provide significantly higher bonding strength with the spacer member 2580 compared to embodiments in which slots 2582 are not defined.

[0164] In some embodiments, the support beam 2558 may extend from the orifice plate 2550 toward the spacer member 2580 and is structured to define a separation distance between the orifice plate 2550 and the spacer member 2580, thereby defining the actuation beam 2540, and may also serve as a protective ring to prevent solvent solutions (e.g., fluids contained in the microvalve 2530) from seeping beneath the spacer member 2580 during use of the microvalve 2530. In a particular embodiment, a support beam compliance layer 2559 may be disposed on the tip of the support beam 2558 adjacent to the spacer member 2580. The support beam compliance layer 2559 may include a gold layer or any other suitable compliance layer. In some embodiments, the second adhesive structure 2556 may also be formed of silicon or glass and is attached to the actuation beam spacer member via glass powder, solder, adhesive, fusion bonding, eutectic bonding, or adhesion.

[0165] The orifice plate 2550 is substantially flat and includes an orifice 2560 extending between its surfaces. A valve seat 2570 may be disposed around the edge of the orifice 2560 on the surface of the orifice plate 2550 facing the actuation beam 2540. The valve seat 2570 defines an internal opening 2571 that is substantially aligned with the orifice 2560 to create an outlet for supplying pressurized fluid to the micro-valve 2530. In some embodiments, a valve seat conforming layer 2572 (e.g., a gold layer) may be disposed on the surface of the valve seat 2570 facing the actuation beam 2540.

[0166] In some embodiments, the orifice plate 2550 can be substantially flat, for example, having a flatness with a coefficient of variation of less than 3 micrometers over at least 15 mm of length and width, such that the orifice plate 2550 is substantially free from bending or twisting. Furthermore, the orifice plate 2550 can have any suitable thickness. In some embodiments, the orifice plate 2550 can have a thickness in the range of 30 micrometers to 90 micrometers (30 micrometers, 40 micrometers, 50 micrometers, 60 micrometers, 70 micrometers, 80 micrometers, 90 micrometers, or 100 micrometers). In other embodiments, the orifice plate 2550 can have a thickness in the range of 100 micrometers to 900 micrometers (e.g., 100 micrometers, 150 micrometers, 200 micrometers, 250 micrometers, 300 micrometers, 350 micrometers, 400 micrometers, 500 micrometers, 600 micrometers, 700 micrometers, 800 micrometers, or 900 micrometers). A thicker orifice plate 2550 facilitates the achievement of a flatter orifice plate.

[0167] The actuating beam 2540 includes a base portion 2542 disposed on the spacer member 2580 and a cantilever portion 2544 extending from the base portion toward the orifice 2560. Except for the differences described below, the actuating beam 2540 is substantially similar to actuating beams 240, 240b. A sealing member 2590 extends from the portion of the actuating beam 2540 that overlaps with the orifice 2560. In some embodiments, the sealing member 2590 is configured to have a shape substantially corresponding to the shape of the orifice 2560 (e.g., a cylindrical shape).

[0168] A sealing blade 2592 extends from the orifice-facing surface of the sealing member 2590 toward the valve seat 2570. The sealing blade 2592 may be shaped to correspond to the periphery of the sealing member 2590. In some embodiments, the sealing blade 2592 is substantially annular and has an inner and outer diameter falling between the inner and outer diameters of the valve seat 2570. When the actuating beam 2540 is in the closed position, the sealing blade 2592 extends toward the upper surface of the valve seat 2570 and contacts the valve seat 2570. The sealing blade 2592 provides a focal point for the downward force provided by the actuating beam 2540, such that a tight seal is formed at the interface between the tip of the sealing blade 2592 and the valve seat 2570.

[0169] Further expansion, Figure 26 It is by Figure 25 Arrow A in the image indicates a magnified view of a portion of the miniature valve 2530. (See image.) Figure 25 As shown, the tip of the sealing blade 2592 is substantially flat, and in some embodiments, it may be coated with a sealing blade compliance layer (e.g., a gold layer). Figure 26The tip of a sealing blade coated with resist 2591 is shown. This resist serves as an etching mask to allow selective etching of the sealing member 2590 to form the sealing blade 2592, which is subsequently removed. In some embodiments, the resist width X2 of the resist 2591 is in the range of 1 micrometer to 15 micrometers (e.g., 1 micrometer, 2 micrometer, 3 micrometer, 4 micrometer, 5 micrometer, 6 micrometer, 7 micrometer, 8 micrometer, 9 micrometer, 10 micrometer, 11 micrometer, 12 micrometer, 13 micrometer, 14 micrometer, or 15 micrometer, including end values), such that the sealing blade width X1 of the sealing blade 2592 is in the range of 8 micrometers to 12 micrometers (e.g., 8 micrometer, 9 micrometer, 10 micrometer, 11 micrometer, or 12 micrometer, including end values). The internal cross-sectional dimension Y1 (e.g., inner diameter) of the resist can be in the range of 20 micrometers to 100 micrometers (e.g., 20 micrometers, 30 micrometers, 40 micrometers, 50 micrometers, 60 micrometers, 70 micrometers, 80 micrometers, 85 micrometers, 90 micrometers, 95 micrometers or 100 micrometers, including the end values), and the external cross-sectional dimension Y2 (e.g., outer diameter) of the resist can be in the range of 30 micrometers to 120 micrometers (e.g., 30 micrometers, 40 micrometers, 50 micrometers, 60 micrometers, 70 micrometers, 80 micrometers, 90 micrometers, 100 micrometers, 105 micrometers, 110 micrometers, 115 micrometers or 120 micrometers, including the end values). The outer cross-sectional dimension Y3 (e.g., outer diameter) of the sealing member 2590 can be in the range of 80 micrometers to 140 micrometers (e.g., 80 micrometers, 90 micrometers, 100 micrometers, 110 micrometers, 120 micrometers, 125 micrometers, 130 micrometers, 135 micrometers or 140 micrometers, including end values).

[0170] The internal cross-sectional dimension Z1 of the valve seat 2570 (e.g., the diameter of the opening 2571 defined in the valve seat 2570) can be in the range of 20 micrometers to 80 micrometers (e.g., 20 micrometers, 30 micrometers, 40 micrometers, 50 micrometers, 55 micrometers, 60 micrometers, 65 micrometers, 70 micrometers, 75 micrometers or 80 micrometers, including end values), and the external cross-sectional dimension Z4 of the valve seat 2570 (e.g., the outer diameter) can be in the range of 100 micrometers to 160 micrometers (e.g., 100 micrometers, 110 micrometers, 120 micrometers, 130 micrometers, 140 micrometers, 145 micrometers, 150 micrometers, 155 micrometers or 160 micrometers, including end values). The first radial distance Z2 from the edge of the opening 2571 defined in the valve seat 2570 to the edge of the valve seat conforming layer 2572 can be in the range of 1 micrometer to 4 micrometers (e.g., 1 micrometer, 2 micrometer, 3 micrometer or 4 micrometers, including end values), and the second radial distance Z3 from the inner radial edge of the sealing blade 2592 to the edge of the opening 2571 defined in the valve seat 2570 can be in the range of 7 micrometers to 15 micrometers (e.g., 7 micrometer, 8 micrometer, 9 micrometer, 10 micrometer, 11 micrometer, 12 micrometer, 13 micrometer, 14 micrometer or 15 micrometers, including end values).

[0171] The cross-section of the sealing blade 2592 is larger than the internal cross-sectional dimension Z1, allowing for axial misalignment between the opening 2571 and the inner radial edge of the sealing blade 2592, while still being able to seal the opening 2571 defined in the valve seat 2570. For example, Figure 27 It shows along Figure 26 The image shows a cross-sectional view of the sealing blade 2592 taken from line BB. (See image.) Figure 27 As shown, the sealing blade 2592 is not axially aligned with the opening 2571, but it is still able to surround and fluid seal the area around the opening 2571 on the valve seat 2570, thereby preventing fluid leakage through the opening 2571 when the actuating beam 2540 is in its closed position (e.g., the default position).

[0172] In some embodiments, a portion of the adhesive structure used to bond the spacer member of the actuating beam to the perforated plate may extend beyond the radial inner edge of the spacer member. For example, Figure 28AThis is a side cross-sectional view of a portion of a microvalve 2630 according to an embodiment. The microvalve 2630 includes an orifice plate 2650. An actuation beam 2640 is disposed on the orifice plate 2650. A base portion 2642 of the actuation beam 2640 is disposed on a spacer member 2680, which is connected to the orifice plate 2650 via a support beam 2658 (e.g., support beam 2558) and a second adhesive structure 2656 (e.g., SU-8 structure). The second adhesive structure 2656 may have a thickness ranging from 2 micrometers to 20 micrometers (e.g., 2 micrometers, 3 micrometers, 4 micrometers, 5 micrometers, 10 micrometers, 12 micrometers, 14 micrometers, 16 micrometers, 18 micrometers, or 20 micrometers, including end values). A plurality of slots or keys 2682 may be defined in the surface of the spacer member 2680 facing the orifice plate 2650. As previously described herein, the second adhesive structure 2656 penetrates the plurality of slots 2682 to form a strong bond with the spacer member 2680. In various embodiments, the plurality of slots 2682 may have a cross-sectional dimension (e.g., width) of about 5 to 10 micrometers (inclusive of end values) and be spaced apart at a spacing of 5 to 10 micrometers (inclusive of end values). In other embodiments, the plurality of slots 2682 may be excluded.

[0173] As previously described herein, the inlet manifold 2610 is bonded to the actuation beam 2640 at its base portion 2642 via a first adhesive structure 2661. The first adhesive structure 2661 may comprise multiple rings of an adhesive (e.g., SU-8) or a structural material such as glass or silicon. At least one ring of the first adhesive structure 2661 is positioned relative to, for example, a second adhesive structure 2656 to balance torsional stresses imposed by movement of the cantilever portion 2644 of the actuation beam 2640 away from the orifice plate 2650. In some embodiments, the first adhesive structure 2661 and the second adhesive structure 2656 may be formed of the same material (e.g., SU-8, silicon, glass, etc.). In some embodiments, multiple slots may also be defined on the surface of the spacer member 2680, on which the first adhesive structure 2661 may be defined to facilitate adhesion, or on any other surface on which the adhesive is disposed.

[0174] The second adhesive structure 2656 may also extend in the radial direction beyond the radially inner edge of the spacer member 2680, such that a portion of the second adhesive structure 2656 having a predetermined length X (e.g., in the range of 5 to 10 micrometers, including end values) is located below the cantilever portion 2644 of the actuating beam 2640. The extended portion of the second adhesive structure 2656 may be axially separated from the bottom surface of the cantilever portion 2644 facing the perforated plate 2650 by an axial distance Y, which may be equal to the thickness of the spacer member 2680.

[0175] In some embodiments, the fluid used with microvalve 2630 or any other microvalve described herein may include a solvent capable of dissolving or swelling the adhesive used to form the first adhesive structure 2661 and the second adhesive structure 2656. In some embodiments, the first adhesive structure 2661 and / or the second adhesive structure 2656 may be formed using an inorganic material (e.g., silicon or glass) that does not react with the solvent. In other embodiments, a thin coating of solvent-resistant organic, inorganic, or mixed / inorganic material may be applied to the exposed surface of microvalve 2630 to protect the first adhesive structure 2661 and the second adhesive structure 2656.

[0176] For example, Figure 28B The miniature valve 2630 is shown as being made of Figure 28A An enlarged view of the portion indicated by arrow B in the diagram. A coating 2686 with a thickness, for example, ranging from 5 nm to 100 nm (5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, or 100 nm, inclusive), can be applied to the microvalve 2630. In some embodiments, an atomic layer deposition (ALD) process can be used to deposit the coating. The coating 2686 can be formed from any suitable material, such as alumina, titanium oxide, zinc oxide, or any other suitable material or combination thereof.

[0177] In some embodiments, any miniature valve described herein may also include a buffer to prevent overshoot of the actuation beam included in the miniature valve. For example, Figure 29 This is a side cross-sectional view of a miniature valve 2730 according to another embodiment. The miniature valve 2730 includes components similar to those described relative to miniature valve 2530. The miniature valve 2730 includes an actuation beam 2740 substantially similar to an actuation beam 2540, but also includes a buffer 2791 extending from the cantilever portion 2744 of the actuation beam 2740 toward an orifice plate 2550. In other embodiments, the buffer 2791 may be disposed on the orifice plate 2550 and extend from the orifice plate toward the cantilever portion 2744 of the actuation beam 2740. The buffer 2791 may be positioned at any suitable location, for example, intermediate between the spacer member 2580 and the sealing member 2590. The buffer 2791 may be formed of the same material (e.g., silicon) as the orifice plate 2550 or the actuation beam 2740. The buffer 2791 may be configured to prevent overshoot of the cantilever portion of the actuation beam 2740 by limiting the movement of the actuation beam 2740.

[0178] In some implementations, the microvalve may include features for limiting the movement of the actuation beam by pushing it back to its default position. For example, Figure 30This is a side cross-sectional view of a miniature valve 3520 according to another embodiment. The miniature valve 3520 includes an orifice plate 3510 defining an orifice 3560 therein. An actuation beam 3540 is positioned on the orifice plate 3510 and spaced apart from it via a spacer 3580. A sealing member 3524 is positioned at an overlap portion 3549 of the actuation beam 3540, configured to contact a valve seat 3522 positioned on the orifice plate 3510 surrounding or overlapping the orifice 3560, and configured to seal the orifice 3560 in the default position of the actuation beam 3540. The overlap portion 3549 is located at the tip of the actuation beam 3540 and overlaps with the orifice 3560. A finger 3517 may be positioned on a post 3515 disposed on the orifice plate 3510 and extends toward the actuation beam 3540 so as to overlap at least with the overlap portion 3549 of the actuation beam 3540. The finger 3517 can be configured to push the overlapping portion 3549 of the actuation beam 3540 toward the valve seat 3522 to ensure that a fluid seal is formed between the sealing member 3524 and the valve seat 3522 in the default position of the actuation beam 3540.

[0179] The finger 3517 may be configured to have rigidity to overcome a charge applied to the actuation beam 3540 by bending or flexing the cantilever portion of the actuation beam 3540 away from the orifice 3560. Once the charge is removed, the finger 3517 may push the cantilever portion back toward the orifice 3560. In other embodiments, a biasing member 3519 (e.g., a coil spring, a disc spring, a beryllium copper spring, a compliant member, etc.) may be operatively coupled to the finger 3517 and configured to be biased when a charge is applied to the actuation beam 3540. Once the charge is removed, the biasing member 3519 may push the overlapping portion 3549 back toward the orifice 3560. In a particular embodiment, the biasing member 3519 may be operatively coupled to the overlapping portion 3549, allowing the finger 3517 to be excluded.

[0180] While the aforementioned embodiments involve cantilevered actuation beams, in other embodiments, the microvalve may comprise a simply supported actuation beam. For example, Figure 31This is a side cross-sectional view of a miniature valve 3620 according to another embodiment. The miniature valve 3620 includes an orifice plate 3610 defining an orifice 3660 therein. An actuation beam 3640 is positioned on the orifice plate 3610 such that a first axial end portion 3646a of the actuation beam 3640 is positioned on and spaced apart from the orifice plate 3610 via a first spacer member 3680a, and a second axial end portion 3646b of the actuation beam 3640 is positioned on and spaced apart from the orifice plate 3610 via a second spacer member 3680. The spacer members 3680a / b are connected to the orifice plate 3610 via corresponding adhesive layers 3656a / b. The actuation beam 3640 includes a bent portion 3648 configured to bend toward or away from the orifice plate 3610. The bent portion 3648 includes an overlapping portion 3649 (e.g., located midway between the axial ends 3646a / b) that overlaps with the orifice 3660. A sealing member 3624 is positioned at the overlapping portion 3649 of the actuating beam 3640 and is configured to contact or overlap a valve seat 3672 positioned on an orifice plate around or overlapping the orifice 3660 to seal the orifice 3660 in its default position. In various embodiments, the valve seat 3672 may be formed of the same material as the adhesive layers 3656a / b (e.g., formed using the same manufacturing operations). Because the overlapping portion 3649 may be located at the center of the actuating beam 3640, the bending of the bent portion 3648 around the axial ends 3646a / b causes the sealing member 3624 to move toward and away from the valve seat 3672 without any angle being applied thereto (i.e., the sealing surface of the sealing member 3624 may remain substantially parallel to the valve seat 3672). Furthermore, any bending of the orifice plate 3610 will also cause a corresponding bending of the actuation beam 3640, allowing the sealing member 3624 to remain in the same position and orientation relative to the valve seat 3672. This allows for a better seal between the sealing surface of the sealing member 3624 and the valve seat 3672, regardless of any bending or twisting of the orifice plate 3610.

[0181] In some embodiments, the microvalve includes: an orifice plate including a first surface and a second surface, the orifice plate including an orifice extending from the first surface to the second surface; an actuation beam disposed spaced apart from the orifice plate, the actuation beam including a base portion and a cantilever portion, the base portion being separated from the orifice plate by a predetermined distance, the cantilever portion extending from the base portion toward the orifice such that an overlapping portion of the cantilever portion overlaps with the orifice, wherein the actuation beam is movable between a closed position and an open position; and a sealing structure including a sealing member disposed at the overlapping portion of the cantilever portion; and wherein when the actuation beam is in the closed position, the cantilever portion is positioned such that the sealing structure seals the orifice to close the microvalve.

[0182] In some embodiments, the actuating beam includes a piezoelectric material layer, and the actuating beam is capable of moving between a closed position and an open position in response to an electrical signal applied to the piezoelectric material. In some embodiments, the microvalve is in the closed position when no electrical signal is applied to the piezoelectric material. In some embodiments, when a reverse polarity electrical signal is applied to the piezoelectric material, the microvalve moves closer to the closed position, or the force holding the microvalve in the closed position increases.

[0183] In some embodiments, the sealing structure includes a stop disposed on the surface of the sealing member, the stop comprising a first portion attached to the surface of the sealing member and a second portion disposed on the first portion adjacent to the orifice plate, wherein the second portion has a larger cross-sectional area than the first portion. In some embodiments, the stop directly contacts the orifice plate in the absence of an electrical signal. In some embodiments, the stop is made of bisphenol A phenolic glycidyl ether-based photoresist. [In some embodiments, each of the sealing member, the first portion, and the second portion is substantially cylindrical in shape.]

[0184] In some embodiments, the sealing structure further includes a valve seat surrounding the orifice, the valve seat defining an opening overlapping the orifice to define a fluid outlet. In some embodiments, the sealing member includes: a sealing member surface facing the orifice, the sealing member surface being substantially parallel to the upper surface of the orifice plate, wherein the sealing member surface is displaced a distance from the valve seat when the actuating beam is in the closed position; and a first sealing blade extending that distance from the sealing member surface toward the orifice plate, wherein the first sealing blade surrounds the entire periphery of the orifice.

[0185] In some embodiments, the sealing member and orifice plate are substantially cylindrical in shape, wherein the orifice has a first diameter and the sealing member has a second diameter larger than the first diameter. In some embodiments, the first sealing blade is annular in shape and includes a first outer diameter larger than the first diameter and smaller than the second diameter. In some embodiments, the first outer diameter is closer to the first diameter than the second diameter.

[0186] In some embodiments, the sealing member further includes a second sealing blade surrounding the first sealing blade, the second sealing blade having a second outer diameter greater than the first outer diameter but smaller than the second diameter, such that an annular gap is formed between the first sealing blade and the second sealing blade. In some embodiments, the first and second sealing blades are formed of the same material as the remainder of the sealing member.

[0187] In some embodiments, the orifice and sealing member are substantially cylindrical in shape, and the valve seat is annular and surrounds the orifice. In some embodiments, the orifice has a first diameter, and the sealing member has a second diameter greater than the first diameter. In some embodiments, the valve seat has an outer diameter between the first and second diameters. In some embodiments, the valve seat has an outer diameter approximately equal to or greater than the second diameter.

[0188] In some embodiments, the sealing member further includes: a narrow portion disposed at an end of the sealing member, the narrow portion defining a sealing member surface facing the orifice; and a sealing vane extending outward from the narrow portion to overlap with the upper surface of the valve seat when the actuating beam is in the closed position.

[0189] In some embodiments, the inner surfaces of the valve seat and the orifice are substantially aligned with each other to form a fluid outlet, wherein the microvalve further includes a coating disposed on the inner surface of the fluid outlet. In some embodiments, the coating covers at least one of the upper surface of the valve seat facing the sealing member or the sealing member surface of the sealing member facing the valve seat. In some embodiments, the coating comprises polydimethylsiloxane.

[0190] In some embodiments, a method of constructing a microelectromechanical system (MEMS) microvalve includes: providing an orifice plate including an orifice; providing an actuating beam having a spacer member and a sealing member attached thereto; forming a portion of a sealing structure on the orifice plate or the sealing member; and after forming this portion of the sealing structure, attaching the actuating beam to the orifice plate such that the sealing member is aligned with the orifice and the sealing structure forms a seal that separates the orifice from the volume of an adjacent actuating beam in a closed position.

[0191] In some embodiments, the portion forming the sealing structure includes setting a valve seat on an orifice plate surrounding the orifice, wherein the method further includes forming an additional portion of the sealing structure on the orifice-facing surface of the sealing member.

[0192] In some embodiments, an additional portion of the sealing structure includes one or more sealing blades, wherein forming the additional portion of the sealing structure includes: depositing an etch-resistant material on a surface facing the orifice; etching a portion of the etch-resistant material such that the remaining portion of the etch-resistant material on the surface facing the orifice corresponds to the position and shape of the one or more sealing blades; isotropically etching the sealing member for a first predetermined time, isotropically etching a portion of the sealing member configured to etch the etch-resistant material below to form the one or more sealing blades; and removing the remaining portion of the etch-resistant material from the surface facing the orifice.

[0193] In some embodiments, the method further includes: anisotropically etching the sealing member for a second predetermined time before removing the etch-resistant material to remove a portion of the sealing member such that the remaining portion forms a higher sealing blade, and then removing the etch-resistant material. In some embodiments, the etch-resistant material includes silicon dioxide.

[0194] In some embodiments, an additional portion of the sealing structure includes a sealing flap extending substantially parallel to the orifice plate from the orifice-facing surface, and wherein forming the additional portion of the sealing structure includes: depositing an etch-resistant material on the orifice-facing surface; and selectively etching the sealing member to remove a portion of the sealing member at the circumferential surface of the sealing member below the etch-resistant material, such that the etch-resistant material extends over the removed portion of the sealing member to form the sealing flap.

[0195] In some embodiments, the method of claim 27 further includes: anisotropically etching a portion of the actuation beam to form a sealing member; and releasing the actuation beam from the substrate to form a cantilever portion of the actuation beam.

[0196] In some embodiments, the injection assembly includes: a valve body including an orifice plate with a plurality of orifices extending therethrough; a plurality of microvalves, each of the plurality of microvalves including: a spacer member disposed on the orifice plate and displaced from a corresponding orifice; an actuation beam including a base portion disposed on the spacer member and a cantilever portion extending from the base portion toward a corresponding orifice such that an overlapping portion of the cantilever portion overlaps with the corresponding orifice, the actuation beam being configured to move between a closed position in which the cantilever portion bends toward the orifice and an open position in which the cantilever portion bends away from the orifice; a sealing structure including a sealing member attached to the overlapping portion and extending toward the corresponding orifice; and a fluid manifold connected to each of the plurality of microvalves to define a fluid reservoir for each microvalves.

[0197] In some embodiments, the actuating beam includes a piezoelectric material layer, the actuating beam being able to move between a closed position and an open position in response to an electrical signal applied to the piezoelectric material, and wherein the micro-valve is in the closed position when no electrical signal is applied to the piezoelectric material layer.

[0198] In some embodiments, the sealing structure includes a stop disposed on the surface of the sealing member, the stop including a first portion attached to the surface of the sealing member and a second portion disposed on the first portion more adjacent to the orifice plate, wherein the second portion has a larger cross-sectional area than the first portion. In some embodiments, the sealing structure also includes a valve seat disposed on the orifice plate adjacent to the orifice, the valve seat defining an opening overlapping the orifice to define a fluid outlet.

[0199] In some embodiments, the sealing member includes: a sealing member surface facing the orifice and substantially parallel to the upper surface of the orifice plate, wherein the sealing member surface is displaced from the valve seat by a certain distance; and a first sealing blade extending from the sealing member surface toward the orifice plate by that distance, wherein the first sealing blade surrounds at least a portion of the orifice, such that a portion of the first sealing blade is positioned at a distance from the orifice around the periphery of the orifice. In some embodiments, the sealing member further includes a second sealing blade surrounding the first sealing blade.

[0200] In some embodiments, the first sealing blade, the second sealing blade, and the valve seat are substantially annular in shape, wherein the valve seat includes an inner diameter and an outer diameter, and wherein when the cantilever portion is in the closed position, the entire first sealing blade and the second sealing blade are disposed between the inner diameter and the outer diameter on the upper surface of the valve seat.

[0201] In some embodiments, the sealing member further includes: a narrow portion disposed at an end of the sealing member, the narrow portion defining a sealing member surface facing the orifice; and a sealing flap extending outward from the edge of the narrow portion at the sealing member surface, wherein the sealing flap extends substantially parallel to the orifice plate and overlaps the upper surface of the valve seat.

[0202] In some embodiments, the miniature valve includes: an orifice plate including a first surface and a second surface, the orifice plate including an orifice extending from the first surface to the second surface; an actuation beam disposed spaced apart from the orifice plate, the actuation beam including a base portion and a cantilever portion, the base portion being separated from the orifice plate by a predetermined distance, the cantilever portion extending from the base portion toward the orifice such that an overlapping portion of the cantilever portion overlaps with the orifice, wherein the actuation beam is movable between a closed position and an open position; and a sealing structure disposed on the actuation beam, the sealing structure including: a sealing member disposed at the overlapping portion of the cantilever portion; and a stop disposed on a surface of the sealing member, the stop including a first portion attached to the surface of the sealing member and a second portion disposed on the first portion adjacent to the orifice plate, wherein the second portion has a larger cross-sectional area than the first portion; and wherein when the actuation beam is in the closed position, the cantilever portion is positioned such that the stop seals the orifice, thereby closing the miniature valve.

[0203] In some embodiments, the microvalve includes: an orifice plate including a first surface and a second surface, the orifice plate including an orifice extending from the first surface to the second surface; an actuation beam disposed spaced apart from the orifice plate, the actuation beam including a base portion and a cantilever portion, the base portion being separated from the orifice plate by a predetermined distance, the cantilever portion extending from the base portion toward the orifice such that an overlapping portion of the cantilever portion overlaps with the orifice, wherein the actuation beam is movable between a closed position and an open position; and a sealing structure disposed on the actuation beam, the sealing structure including: a valve seat surrounding the orifice, the valve seat defining an opening around the orifice to define a fluid outlet; a sealing member disposed at the overlapping portion of the cantilever portion; and a first sealing blade extending a distance from a sealing member surface of the sealing member toward the orifice plate, the first sealing blade surrounding the entire periphery of the orifice, the sealing blade being configured to contact the valve seat in a closed position to seal the orifice and close the microvalve. In some embodiments, the sealing member further includes a second sealing blade surrounding the first sealing blade, the second sealing blade having a second outer diameter greater than the first outer diameter but smaller than the second diameter, such that an annular gap is formed between the first sealing blade and the second sealing blade.

[0204] In some embodiments, the microvalve includes: an orifice plate including a first surface and a second surface, the orifice plate including an orifice extending from the first surface to the second surface; an actuation beam disposed spaced apart from the orifice plate, the actuation beam including a base portion and a cantilever portion, the base portion being separated from the orifice plate by a predetermined distance, the cantilever portion extending from the base portion toward the orifice such that an overlapping portion of the cantilever portion overlaps with the orifice, wherein the actuation beam is movable between a closed position and an open position; and a sealing structure disposed on the actuation beam, the sealing structure including: a sealing member disposed at the overlapping portion of the cantilever portion; a narrowing portion disposed at an end of the sealing member, the narrowing portion defining a sealing member surface facing the orifice; and a sealing flap extending outward from the narrowing portion and configured to seal the orifice to close the microvalve when the actuation beam is in the closed position.

[0205] As used herein, the terms “about” and “approximately” generally refer to plus or minus 10% of the stated value. For example, approximately 0.5 would include 0.45 and 0.55, approximately 10 would include 9 to 11, and approximately 1000 would include 900 to 1100.

[0206] As used herein, the terms “joint”, “connection”, etc., refer to the joining of two components directly or indirectly to each other. Such joining can be fixed (e.g., permanent) or movable (e.g., removable or releasable). Such joining can be achieved by forming a single monolithic body by integrating two components or two components and any additional intermediate components together, or by attaching two components or two components and any additional intermediate components to each other.

[0207] References to the location of elements herein (e.g., “top,” “bottom,” “above,” “below,” etc.) are used only to describe the orientation of the various elements in the figures. It should be noted that the orientation of the various elements may differ according to other exemplary embodiments, and such variations are intended to be covered by this disclosure.

[0208] The construction and arrangement of the elements shown in the exemplary embodiments are merely illustrative. Although only a few embodiments of this disclosure have been described in detail, those skilled in the art will readily understand that many modifications are possible (e.g., variations in the size, dimensions, structure, shape and proportions, parameter values, mounting arrangements, use of materials, color, orientation, etc.) of the various elements without departing from the novel teachings and advantages of the subject matter. For example, an element shown as integrally formed may be composed of multiple parts or elements, the positions of the elements may be reversed or otherwise changed, and the nature or number or position of discrete elements may be altered or varied.

[0209] Additionally, the term "exemplary" is used to indicate that it is used as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "example" is not necessarily to be construed as preferred or advantageous over other embodiments or designs (and such terms are not intended to mean that such an embodiment is necessarily a particular or best example). Rather, the use of the term "exemplary" is intended to present the concept in a concrete manner. Therefore, all such modifications are intended to be included within the scope of this disclosure. Other substitutions, modifications, alterations, and omissions may be made in the design, operating conditions, and arrangements of the preferred and other exemplary embodiments without departing from the scope of the appended claims.

[0210] Other substitutions, modifications, alterations, and omissions may be made in the design, operating conditions, and arrangements of various exemplary embodiments without departing from the scope of the invention. For example, any element disclosed in one embodiment may be combined with or utilized in any other embodiment disclosed herein. Similarly, for example, the order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. Any device-plus-function clause is intended to cover the structure described herein for performing the functions, and is not only a structural equivalent but also an equivalent structure. Other substitutions, modifications, alterations, and omissions may be made in the design, operating configuration, and arrangement of preferred and other exemplary embodiments without departing from the scope of the appended claims.

Claims

1. A miniature valve, comprising: An orifice plate, the orifice plate including a first surface and a second surface, the orifice plate including an opening extending from the first surface to the second surface; An actuating beam is provided at a distance from the orifice plate. The actuating beam includes a base portion and a cantilever portion. The base portion is separated from the orifice plate by a predetermined distance. The cantilever portion extends from the base portion toward the orifice, such that the overlapping portion of the cantilever portion overlaps with the orifice. The actuating beam is movable between a closed position and an open position. Valve seat, the valve seat surrounding the orifice; as well as A sealing structure, the sealing structure comprising: A sealing member is disposed at the overlapping portion of the cantilever section; and Multiple sealing blades extending from the surface of the sealing member toward the valve seat, The plurality of sealing blades includes a first group of circumferentially spaced sealing blade segments and a second group of circumferentially spaced sealing blade segments concentrically disposed on the inner or outer side of the first group of sealing blade segments. Wherein, the gaps between adjacent sealing blade segments of the first group of sealing blade segments are circumferentially staggered relative to the gaps between adjacent sealing blade segments of the second group of sealing blade segments.

2. The microvalve of claim 1, wherein the actuating beam comprises a piezoelectric material layer, the actuating beam being movable between the closed position and the open position in response to an electrical signal applied to the piezoelectric material.

3. The micro valve of claim 1, wherein the sealing structure further comprises a stop disposed on the surface of the sealing member, the stop comprising a first portion attached to the surface of the sealing member and a second portion disposed on the first portion adjacent to the orifice plate, wherein the second portion has a larger cross-sectional area than the first portion.

4. The miniature valve of claim 3, wherein the stop is made of bisphenol A phenolic glycidyl ether photoresist.

5. The micro valve of claim 3, wherein each of the sealing member, the first portion, and the second portion is substantially cylindrical in shape.

6. The micro valve of claim 1, wherein the valve seat defines an opening that overlaps with the orifice to define a fluid outlet.

7. The micro valve of claim 6, wherein the plurality of sealing blades surround the entire periphery of the orifice.

8. The micro valve of claim 7, wherein the sealing member and the orifice plate are substantially cylindrical in shape, wherein the orifice has a first diameter, and the sealing member has a second diameter greater than the first diameter.

9. The micro valve of claim 8, wherein a portion of the plurality of sealing blades is annular and includes a first outer diameter that is larger than the first diameter and smaller than the second diameter.

10. The micro valve of claim 6, wherein the inner surfaces of the valve seat and the orifice are substantially aligned with each other to form a fluid outlet, wherein the micro valve further comprises a coating disposed on the inner surface of the fluid outlet.

11. The micro valve of claim 6, further comprising a compliance layer covering at least one of the upper surface of the valve seat facing the sealing member or the sealing member surface of the sealing member facing the valve seat.

12. The microvalve of claim 11, wherein the compliant layer comprises gold.

13. The micro valve of claim 1, wherein the plurality of sealing blades comprises silicon.

14. A spraying assembly, comprising: A valve body, the valve body including an orifice plate, the orifice plate including a plurality of orifices extending therethrough; Multiple micro valves, wherein each of the multiple micro valves comprises: An actuating beam includes a base portion and a cantilever portion extending from the base portion toward a corresponding orifice, such that an overlapping portion of the cantilever portion overlaps with the corresponding orifice, the actuating beam being configured to move between a closed position in which the cantilever portion bends toward the orifice and an open position in which the cantilever portion bends away from the orifice. Valve seat, the valve seat surrounding the orifice; and A sealing structure, the sealing structure comprising: A sealing member attached to the overlapping portion and extending toward the corresponding orifice; and A plurality of sealing blades extending from the surface of the sealing member toward the valve seat, wherein adjacent sealing blades are spaced apart, and the spacers are configured to push particles away from the seal formed between the plurality of sealing blades and the valve seat; and A fluid manifold is connected to each of the plurality of microvalves to define a fluid reservoir for each of the plurality of microvalves.

15. The injection assembly of claim 14, wherein the actuating beam includes a piezoelectric material layer, the actuating beam being movable between the closed position and the open position in response to an electrical signal applied to the piezoelectric material layer, and wherein the microvalve is in the closed position when no electrical signal is applied to the piezoelectric material layer.

16. The injection assembly of claim 14, wherein the sealing structure includes a stop disposed on the surface of the sealing member, the stop including a first portion attached to the surface of the sealing member and a second portion disposed on the first portion more adjacent to the orifice plate, wherein the second portion has a larger cross-sectional area than the first portion.

17. The injection assembly of claim 14, wherein the sealing structure further comprises a valve seat disposed on the orifice plate adjacent to the orifice, the valve seat defining an opening overlapping the orifice to define a fluid outlet.

18. The injection assembly of claim 17, wherein the plurality of sealing blades surround at least a portion of the orifice, such that portions of the plurality of sealing blades are disposed at a distance from the orifice around the periphery of the orifice.

19. The injection assembly of claim 18, wherein the plurality of sealing blades comprises a plurality of concentric sealing blades.

20. The spray assembly of claim 14, wherein the plurality of sealing blades comprises silicon.

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