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Title:
ADAPTIVELY CONTROLLED PIEZOELECTRIC ACTUATOR
Document Type and Number:
WIPO Patent Application WO/2015/122996
Kind Code:
A1
Abstract:
Methods, systems, and devices are disclosed for improved piezoelectric actuators in applications such as fuel injectors. An assembly of thin sheets may be tape cast and co-fired in piezoelectric (PZT) layers and spaced between thin sheets or one or more plated layers of electrical conductors or electrodes. The electrical conductors or electrodes may be isolated in at least two circuits by insulators and provided in integrated stacks along with instrumentation components and data transfer filaments. An assembly of stacked layers may produce motion upon actuation by application of a suitable electrical potential is adaptively operated to overcome infidelity due to vibration, thermal expansion or contraction and to produce controlled actuation motion proportional to the applied electrical potential.

Inventors:
MCALISTER ROY EDWARD (US)
SHELLEY WILLIAM FRANKLIN (US)
Application Number:
PCT/US2015/012095
Publication Date:
August 20, 2015
Filing Date:
February 04, 2015
Export Citation:
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Assignee:
MCALISTER TECHNOLOGIES LLC (US)
ADVANCED GREEN TECHNOLOGIES LLC (US)
International Classes:
F02M51/06
Foreign References:
EP1650816A12006-04-26
JP2001244514A2001-09-07
US20080202477A12008-08-28
US20090179088A12009-07-16
US6414418B12002-07-02
Attorney, Agent or Firm:
SMITH, Andrew, R. (321 North Clark Street Suite 230, Chicago IL, US)
Download PDF:
Claims:
CLAIMS

1 . A piezoelectric actuator comprising:

a plurality of piezoelectric layers arranged in a piezoelectric stack;

a plurality of electrode layers each positioned proximate to a border of the piezoelectric stack and arranged between pairs of the plurality of piezoelectric layers such that each electrode layer of the plurality of electrode layers is isolated from other electrode layers of the plurality of electrode layers, each electrode layer running continuously along the border of the piezoelectric stack;

a first outside electrode conductor bonded to a first set of alternating electrode layers within the stack; and

a second outside electrode conductor bonded to a second set of alternating electrode layers within the stack;

wherein the first and second sets of alternating electrode layers are mutually exclusive to form a circuit with each piezoelectric layer between electrode layers receiving a voltage when the voltage is established between the first outside electrode conductor and the second outside electrode conductor.

2. The piezoelectric actuator of claim 1 , wherein the first and second outside electrodes are one or more of etched into the layers or sprayed onto the layers.

3. The piezoelectric actuator of claim 1 , further comprising a plurality of insulators positioned between alternating electrode layers of the plurality of electrode layers.

4. The piezoelectric actuator of claim 3, wherein a composition of each of the plurality of insulators includes a high thermal conductivity insulation material including beryllium, aluminum nitride, silicon nitride, and aluminum boride.

5. The piezoelectric actuator of claim 1 , wherein the bonding of the first outside electrode conductor to the first set of alternating electrode layers within the stack and the bonding of the second outside electrode conductor to the second set of alternating electrode layers within the stack includes one or more of friction welding, soldering, brazing, laser welding, contact pressure, and mechanical force.

6. The piezoelectric actuator of claim 5, wherein a material of both the first and second outside electrode conductors includes a thermal expansion rating that is greater than the thermal expansion rating of both the plurality of piezoelectric layers and the plurality of electrode layers.

7. The piezoelectric actuator of claim 1 , further comprising a friction reducing layer between each piezoelectric layer and the first and second outside electrode conductors, wherein the friction reducing layer includes one or more of boron nitride, a metal oxide, and a hydroxide.

8. The piezoelectric actuator of claim 1 , further comprising a plate held in a fixed position on a first surface that is opposite an electrode layer of a first piezoelectric layer of the stack and an armature arranged on a second surface that is opposite an electrode layer of a last piezoelectric layer of the stack.

9. The piezoelectric actuator of claim 8, further comprising a tensile member biased against either the plate or the armature.

10. The piezoelectric actuator of claim 8, wherein the armature is coated in a high thermal conductivity insulation material including beryllium, aluminum nitride, silicon nitride, and aluminum boride.

1 1 . The piezoelectric actuator of claim 8, wherein the armature includes a thin film coating of aluminum nitride.

12. The piezoelectric actuator of claim 1 , wherein a composition of each piezoelectric layer of the plurality of piezoelectric layers includes one or more of barium titanate, lead titanate, and lead zirconate titanate.

13. The piezoelectric actuator of claim 1 , wherein a composition of the each electrode layer of the plurality of electrode layers includes one or more conductive materials including silver, gold, nickel, cobalt, aluminum, tantalum, and copper.

14. The piezoelectric actuator of claim 1 , further comprising a hole running through the piezoelectric stack.

15. The piezoelectric actuator of claim 14, wherein the hole carries one or more of sensor instrumentation, conductive filaments, and non-conductive filaments.

16. The piezoelectric actuator of claim 15, wherein the conductive filaments are conductively connected to the each electrode layer of the plurality of electrode layers.

17. The piezoelectric actuator of claim 14, wherein a dielectric material lines the hole.

18. A fuel injection device comprising:

an injector body having a front portion and a rear portion;

a valve disposed within a valve seat of the injector body and substantially carried by the front portion of the injector body, the valve including a valve stem and a coaxial nozzle;

a piezoelectric actuator substantially carried by the rear portion of the injector body, the piezoelectric actuator having an armature disposed toward the valve stem;

one or more electromagnetic windings positioned in proximity of the co-axial nozzle;

one or more controllers; and

one or more computer memories communicatively coupled to the one or more controllers, the one or more computer memories including an adaptive control module storing tangible computer-executable instructions to, when executed by the one or more controllers:

receive monitored data from a plurality of sensors embedded in the injector body, and modify one or more of a baseline voltage or a baseline voltage event timing in response to the monitored data to one or more of:

activate the piezoelectric actuator and cause the armature to actuate the valve, and energize the one or more electromagnetic

windings to alter an included angle of a fuel plume as the fuel exits the coaxial nozzle of the valve.

19. The fuel injection device of claim 18, wherein the adaptive control module further stores tangible computer-executable instructions to adjust a magnitude of the voltage to the piezoelectric actuator, the magnitude of the voltage controlling a current and acceleration of a fuel flow through the valve and into a combustion chamber.

20. The fuel injection device of claim 19, wherein the magnitude of the voltage is between approximately 1 0V DC and 500V DC.

21 . The fuel injection device of claim 18, wherein the coaxial nozzle is formed by a plurality of electrodes at a front end of the valve.

22. The fuel injection device of claim 18, further comprising a compression means carried by the injector body, the compression means biasing the piezoelectric actuator toward the rear portion of the injector body to return the piezoelectric actuator to a first state after being activated by the controller to a second state.

23. The fuel injection device of claim 18, further comprising a trunk line running through the piezoelectric actuator and the valve, the trunk line carrying one or more communication filaments from the plurality of sensors to the controller. The fuel injection device of claim 23, wherein the trunk line carries the one or more communication filaments within one or more dielectric separator tubes.

25. The fuel injection device of claim 1 8, wherein the monitored data includes one or more of compressive loading of the piezoelectric actuator against the valve, a gap between the valve and the valve seat, a piston acceleration, a piston location, a fuel injection timing, a fuel injection pattern, a fuel injection penetration, a combustion chamber pressure, an ignition timing, a combustion pattern, a temperature, and a power production.

26. The fuel injection device of claim 18, wherein the modified one or more of the baseline voltage includes a voltage pulse generated by a change in capacitance of the piezoelectric actuator upon deactivating the piezoelectric actuator triggers a capacitance discharge for a Lorentz ion thrusting or a corona ignition event within a combustion chamber.

The fuel injection device of claim 18, further comprising a magnet disposed at the coaxial nozzle to control an included angle of fuel that is launched as conical rays or sheets from the coaxial nozzle.

Description:
ADAPTIVELY CONTROLLED PIEZOELECTRIC ACTUATOR

CROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims priority to U.S. Provisional Application No.

61 /928,937, filed on January 1 7, 2014.

TECHN ICAL FIELD

[0002] This patent document relates to systems, devices and processes that use piezoelectric actuators.

BACKGROUND

[0003] Piezoelectric motion actuators in applications such as fluid flow control valves, acoustical devices, and reversible motor-generators are useful because a relatively small amount of electrical energy can be used to very quickly exert large thrust force. Problems however include the very small actuation motion provided by a piezoelectric material, corrosion due to galvanic potentials presented by the dissimilar materials of construction, fabrication complications, and practical applications that often produce or require thermal expansion and/or contraction movements that may rival or exceed the piezoelectric thrust range of motion to decrease the fidelity of actuation position or the net cyclic displacement excursion.

SUMMARY

[0004] Disclosed methods, systems, and devices comprise materials,

manufacturing methods, application integration, motion detection, adaptive control and combined functions provide new outcomes and new solutions. An assembly of thin sheets such as selected materials that are tape cast and co-fired such as piezoelectric (PZT) layers spaced between thin sheets or one or more plated layers of electrical conductors or electrodes that are isolated in at least two circuits by insulators are provided in integrated stacks along with instrumentation components and data transfer filaments. An assembly of stacked layers to produce motion upon actuation by application of a suitable electrical potential is adaptively operated to overcome infidelity due to vibration, thermal expansion or contraction and to produce controlled actuation motion proportional to the applied electrical potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The figures described below depict various aspects of the methods, systems, and devices disclosed herein. It should be understood that each figure depicts an embodiment of a particular aspect of the disclosed methods, systems, and devices, and that each of the figures is intended to accord with a possible embodiment thereof. Further, wherever possible, the following description refers to the reference numerals included in the following figures, in which features depicted in multiple figures are designated with consistent reference numerals.

[0006] Figure 1 A shows a top view of shape variations of a PZT assembly in accordance to the principles of the disclosure.

[0007] Figurel B shows an enlarged section view of a PZT assembly in accordance with the principles of the disclosure.

[0008] Figurel C shows perspective views of shape variations of a PZT assembly in accordance with the principles of the disclosure.

[0009] Figures 2A and 2B PZT assemblies in accordance to the principles of the disclosure.

[0010] Figures 3A and 3B show other PZT assemblies in accordance with the principles of the disclosure.

[0011] Figures 4A and 4B show still other PZT assemblies in accordance to the principles of the disclosure.

[0012] Figure 4C shows an end view of a trunk line and various features in accordance to the principles of the disclosure.

[0013] Figure 4D shows a PZT assembly in accordance to the principles of the disclosure.

[0014] Figures 5A, 5B, 5C, 5D, and 5F show various views of a fuel injection device employing a PZT assembly in accordance to the principles of the disclosure.

[0015] Figure 5E shows an actuator assembly for use with a PZT assembly in accordance to the principles of the disclosure.

[0016] Figure 6 shows an end view of a partial section of a fuel injection device facing a combustion chamber. [0017] Figure 7 shows process steps in accordance with principles of the disclosure.

DETAILED DESCRIPTION

[0018] PIEZOELECTRIC ACTUATOR

[0019] Figures 1 A, 1 B and 1 C show various shapes such as 150, 1 52, and 154 of an assembly 1 00 of thin co-fired piezoelectric (PZT) layers 102 that are assembled with electrode layers 104. While Figures 1 A and 1 C illustrate three possible shapes for the various assemblies as described herein, a person having ordinary skill in the art would recognize that many other shapes for the assembly are also possible without departing from the spirit and scope of the inventions.

[0020] Figure 2A illustrates another assembly 200 of thin co-fired PZT layers 1 02 with electrode layers 104. In some embodiments, an assembly 200 includes copper electrodes 1 04 that may be etched into the layers 102.

[0021] The various assemblies as described herein may include an approximately central hole 156 as shown in assembly 250 of Figure 2B. The hole 156 may be provided through the stacked assembly by using preformed components 1 02 and 104 with central holes to form the stack, and/or green machining the stack or other methods for placing the approximately central hole before or after heat treatment of the assembly. Machining at one or more selected manufacturing stages includes the use of cutting tools such as broaches, die punches, milling and turning cutters, laser cutting with suitable continuous or pulsed radiation, electro-discharge machining (EDM), electrochemical machining (ECM), and/or various other suitable methods including selective chemical etching. Illustratively, electrodes 104 can be selectively etched or recessed by chemical solutions such as ferric chloride including surface active agents and may be heated and/or sprayed in applications to provide for electrode isolation.

[0022] In some embodiments of the assembly (e.g., assembly 275), subsequent additions of suitable dielectric material may be made to form insulators 106 as shown in Figure 3A for stack assemblies without the central hole. Figure 3B shows the location of additional insulator material 106 in stack assemblies with the central hole (e.g., assembly 290). [0023] With reference to Fig. 3A, and in assemblies with or without a central hole, alternating electrode layers 104 are connected to a first set of outside electrode conductors 1 08. Remaining alternating electrode layers 104 are connected to a second set of outside electrode conductors 1 10. The first outside electrode conductor 108 may be positive and the second outside electrode conductor may be negative. This forms a circuit with each piezoelectric layer 102 between electrode layers 104 receiving a voltage gradient when such voltage is established between electrode conductor 108 and electrode conductor 1 1 0. Various other embodiments may include connections to counter electrode connectors 1 1 1 and/or 1 13 at selected locations on the inside of the central passageway trunk line 404 as shown in Figure 4A. While first and second electrode conductors are described and illustrated, it may be recognized that any number of electrode pairs, positive and negative, may be employed to form a circuit with each piezoelectric layer 1 02.

[0024] Electrode conductors 108 and 1 10 may be any suitable conductor material and may be the same or different than electrode layers 104. In some applications electrode conductors 1 08 and 1 10 are made of material selections that produce reduced or greater thermal expansions than the stack assembly. Illustratively, electrode conductors 1 08 and 1 10 may be made of a material that is able to expand at a greater rate than the stack assembly and may be suitably bonded to each respective electrode 1 04 for the purpose of assuring little or no resistance to stack motion on actuation throughout the range of operating temperatures. Suitable electrical connections may be made by bonding. In some embodiments, connection of the electrode conductors 108, 1 10 to the electrode layers 104 made by friction welding, soldering, brazing, and laser welding or by application of contact pressure or mechanical force including spring loading force. Such connections between respective electrode layers 1 04 and electrode conductors 108 and 1 10 may be made by providing film interruptions or after coating the piezoelectric layer 1 02 with friction reducing and/or anti-bonding films or coatings and/or other spacing purposes with materials such as boron nitride, selected metal oxides, and/or hydroxides such as AI(OH) 3 and/or Mg(OH) 2 .

[0025] In certain embodiments, an assembly material such as a soluble polymer or another temporary delivery and/or spacer material is placed on piezoelectric layers 102 or other components. In certain embodiments such material is reactive such as for production of a ceramic substance including various oxides, nitrides, etc., and/or thermoplastic, and/or thermosetting such as epoxy with selected fillers to cool, gel, react or otherwise mature into an insulating material for utilization in locations such as 106. In other embodiments the material is a precursor for production of conductive substances for utilization in locations such as 104 and/or 1 1 1 or 1 13 to provide a connector circuit or longer length of connector segments. Illustratively conductor precursor materials can improve electrode conductors 1 08, 1 1 0, 1 1 1 , and/or 1 13 by filling spaces between electrode layers 1 04 that may result from bumps or curvilinear spans of interfaces between such components and conductor segments. This provides improved electrical efficiency for piezoelectric actuation and assures maintenance-free operation of electrode conductors 108 and 1 1 0 including minimization of stresses in the bonded connections. Thus, the total change in the stack length is the sum of each piezoelectric length change upon application of a voltage of controlled magnitude to electrode conductors 1 08 and 1 1 0. Stack assemblies with a sufficient number of alternating unit cells of

piezoelectric layers 102 and electrode layers 104 are made to produce adequate motion upon actuation by application of a suitable electrical potential or voltage to the isolated parallel electrode layers 1 04 through isolated electrode conductors 108 and 1 1 0.

[0026] With reference to Figure 4B, an exemplary application that holds the stack assembly in compression, plate 1 20, may be held in a fixed base position. Output armature 1 22 may be allowed to move in response to actuation by application of a voltage of suitable magnitude across electrode conductors 108 and 1 1 0.

[0027] Typical piezoelectric material selections include barium titanate (BaTiO 3 ), lead titanate (PbTiO 3 ) and various lead zirconate titanates (Pb[Zr x Th_ x ]O 3 0 <x<1 ) or (PZT). Such thin layers of piezoelectric layers 102 may be sprayed, electrostatically deposited, or tape cast to provide uniformity and to facilitate rapid manufacturing processes.

[0028] One or more parallel plated electrode layers 104 of suitable conductive materials such as silver, gold, nickel, cobalt, aluminum, tantalum or copper may separate each piezoelectric layer 1 02. Insulators 106 may be made of high thermal conductivity insulation material such as beryllium oxide or aluminum nitride. The insulators 106 may be formed by suitable methods such as powder compaction by microwave and/or spark induction consolidation and/or sol-gel conversions which may include components to control thermal expansion. Examples of such

components include solid solution additives such as silicon nitride or aluminum boride. BeO, AIN, Si 3 N 4 , and AIB 2 may also be deposited onto the armature 1 22 surface through vapor deposition techniques such as chemical vapor deposition, pulsed laser deposition, or sputtering. In other applications, insulators 106 may include injection or compression molded thermoplastic or higher temperature polymers such as polyimide, polyetherimide, polyamidimide, that may be added by powder sprays, electrostatic depositions, or solvent suspensions. Other alternatives that may be used individually or in various combinations with other alternatives for the insulators 1 06 may include conformal condensation coatings such as poly-para- xylene or "parylene" formulas, amorphous fluoropolymers, and polyamides.

[0029] With reference to Figure 4A, an exemplary application is a stack assembly 400 with a sensor instrumentation and filament communication trunk line 404 extending into or through the central hole 156. In some applications, the trunk line 404 includes sensors 132 that detect motion upon application of voltage across electrode conductors 1 08 and 1 10. For example, the application of the voltage across electrode conductors 108 and 1 1 0 causes the axial motion of assembly 400 as shown in Figure 4D. Suitable sensors for monitoring and measuring the piezoelectric stack motion include strain-resistance, capacitance, and optical devices such as Fabry-Perot devices including fibers.

[0030] With reference to Figure 4B, an end-on view of the trunk line 404 shows conductive filaments 124, 1 26, 128, 130 (e.g., copper wire or other conductors) and non-conductive components 132 (e.g., fiber optics, light pipes, etc.). Conductive filaments such as 124, 1 26, 128, 130 may be of any suitable shape such as circular wire, flat strips, and/or contacts that are spring loaded against selected electrodes 104. Such insulated consolidations of carbon nanotube bundles and/or single or multi-strand metal conductors that are surrounded by non-conductive fiber optics or light pipes 132 provide integrated trunk line protection of electrical and nonelectrical components including sensors. The assembled components of the trunk line may be isolated by dielectric material 106A (Fig. 4A) that is different or the same as the insulator 106 material selection for purposes such as providing resilient

accommodation of motion by stack assembly 400, providing one or more pathways for fluid flow between trunk line 404 and the adjacent piezoelectric stack

components, and providing anti-friction surface to reduce drag between trunk line 404 and surrounding stack elements. Suitable organic or inorganic material selections for dielectric material 1 06A include ceramics, glass, thermoplastic and thermoset polymers. Suitable materials for insulator 106B include the same materials as described herein with reference to element 1 06 along with lower modulus of elasticity selections such as elastomers including silicone rubbers, various types of Viton, Buna-N, EPDM and urethanes.

[0031] In some instances, the piezoelectric stack is held in preloaded

compression and upon electrical energization the compressive stress on the stack is increased as the stack increases in length against the preload force. Suitable methods for assured application of compressive loading (i.e., a tensile member such as spring bellows 503 as shown in 500) may include utilization of a suitably strong support frame or canister. The tensile member may compressively load the stack and/or the assembly may include compression spring members such as confined urethane, Belleville washers, helical springs, and/or a separate preloaded casing spring such as a cylindrical cartridge or bellows to apply the compressive loading of the stack components 120 and 122 as schematically shown in Figure 4C as various forces Fc.

[0032] In some embodiments, an assembly 425 (Figure 4D) may employ a piezoelectric, thin film material as a conformal coating having high thermal conductivity combined with high electrical resistivity. Aluminum nitride (AIN) can provide multiple functions as a surface coating of the armature 1 22. In addition to high thermal conductivity combined with high electrical resistivity, aluminum nitride is piezoelectric in thin film form. As such, the AIN conformal coating could be used as a sensor network (e.g., an axial load sensor 426 including AIN) to monitor operational events and/or the health of the armature 122 or as a feedback mechanism for closed loop control of the armature 1 22. AIN thin film sensors 428 may be applied to selected portions or normal or approximately normal to the length of the actuator. AIN thin film sensors 428 may transfer heat from the armature 122 as well as employ the piezoelectric effect to measure the force exerted by the armature 1 22 on each deflection and/or stroke. AIN thin film sensors 428 applied to the sides of the armature 1 22 would thus provide transfer of heat to or from the armature 122, but would also act as a strain gauge displacement measurement of the armature 1 22 on each stroke. These sensors could be used for real-time closed-loop proportional control of the act armature 122 by adjusting the applied voltage to the armature 1 22. In addition, these sensors could be used as actuator health monitoring devices by monitoring the decrease in displacement or force exerted by the armature 122 due to degradation such as fatigue mechanisms over time.

[0033] Heat transfer is further improved by heat transfer of conductive

components and/or circulation of fluid through central passageway 156 and or tubular components within this passageway. Heat transfer fluids include fuels and/or refrigerants that change phase to provide heat pipe advantages, oils that do not change phase and gases that provide high heat transfer characteristics such as hydrogen and helium.

[0034] In certain embodiments the manufacturing method can provide a suitable liquid or solid desiccant and/or getter substance for reducing or eliminating moisture or other adverse agents that could reduce the fatigue or stability by elimination of electrolytic connection of potential galvanic cell components in the various materials that are utilized.

[0035] FUEL INJECTION DEVICE EMPLOYING PIEZOELECTRIC ACTUATOR

[0036] The assemblies described herein may be employed in a fuel injection device 500 that provides one or more piezoelectric driven valve openings to deliver fuel bursts into a combustion chamber of an engine as shown in Figures 5A, 5B, 5C, 5D, 5E and 5F. The device 500 may include a body 501 carrying a piezoelectric stack actuator 502 connected to the valve stem 561 of valve 560. Actuator 502 operates in compression against compression means 503 such as a suitable elastic member, spring bellows, and/or a helical wire compression spring (not shown) to exert an opening force through an appropriately configured armature (corresponding to schematically illustrated armature 1 22) on a valve stem 561 of valve 560. In certain applications the spring may be one or more Belleville washers, and/or a helical compression spring, and/or a canister such as a bellows. The canister or bellows may surround and also hermetically seal the piezoelectric stack assembly including information trunk line 568 (Fig. 5C). In some embodiments, the compression means 503 returns the piezoelectric actuator 502 to a first positional state after activation by a voltage to a second positional state.

[0037] The trunk line 568 may include communication filaments from sensors such as 540 and 562 (Fig. 5B) to a microprocessor controller such as 510 (Fig. 5A) which may be incorporated in the injector assembly 500. In certain applications, the piezoelectric actuator is operated by controller 51 0 with adaptively varied voltage to extend or contract as needed to remain in suitable compressive loading of the armature of actuator 502 against the adjacent stem of valve 560 or of a linkage that connects the actuator to valve 560. Alternatively, controller 510 can include an adaptive control module 510C including tangible computer-executable instructions that are executed by the controller 510 to adaptively provide a suitable gap between the actuator and the valve stem or the linkage to allow event timing variations including acceleration of the actuator prior to engagement with the valve stem or linkage to operate valve 560 by exchange of kinetic energy. Instrumentation included in sensors 562 including piezoelectric, acoustical, and/or optical transponders monitor the compressive loading or alternatively the gap provided between valve 560 and the valve seat as a result of adaptive control by 510 and provide this monitored data to the controller 510. Similar instrumentation that can be provided in bundle 540 can monitor the piston acceleration and location along with resulting events including the timing, pattern and penetration of fuel injection, the combustion chamber pressure, timing of ignition along with combustion pattern and temperature profile to optimize fuel efficiency, power production, torque matching per cylinder and/or by engine control according to a master cylinder, etc. The sensors 562 and dielectric 566 may be communicatively connected to the controller 510 to provide the monitored data for the adaptive control module 51 0C. Instructions of the adaptive control module may then modify one or more parameters of the monitored data to perform the adaptive control and other functions as herein described. For example, the controller 510 may execute instructions of the adaptive control module to receive monitored data from a plurality of sensors embedded in the injector body, modify one or more of a baseline voltage (i.e., an initial voltage used to activate the piezoelectric actuator for a combustion event) or a baseline voltage event timing (i.e., when during the combustion cycle of an engine, the controller 510 causes the piezoelectric actuator to activate) in response to the monitored data, and send a baseline voltage of a modified baseline voltage to the piezoelectric actuator according to the baseline voltage event timing or the modified baseline voltage event timing.

[0038] The controller 51 0 may include a register set or register space which may be entirely on-chip, or alternatively located entirely or partially off-chip and directly coupled to the controller 51 0 via dedicated electrical connections and/or via an interconnection bus. The controller 510 may be any suitable processor, processing unit or microprocessor. Although not shown, the fuel injector 500 or any system employing the injector 500 may be a multi-processor device and, thus, may include one or more additional processors that are identical or similar to the controller 510 and that are communicatively coupled to an interconnection bus. The controller 510 may also be coupled to a chipset 51 OA, which includes a memory controller and a peripheral input/output (I/O) controller. As is well known, the chipset 51 OA typically provides I/O and memory management functions as well as a plurality of general purpose and/or special purpose registers, timers, etc. that are accessible or used by one or more processors coupled to the chipset. The memory controller performs functions that enable the processor controller 510 (or processors if there are multiple processors) to access a system memory and a mass storage memory (not shown).

[0039] The controller 51 0 may also include one or more memories 51 0B storing instruction modules 510C to implement the adaptive control functions of the injector 500 as herein described. For example, the adaptive control module 510C may be stored in memory 51 0B and include tangible computer-executable instructions that are stored in a non-transitory computer-readable storage medium. The instructions of the adaptive control module 51 0C are executed by the controller 510 or the instructions can be provided from computer program products that are stored in tangible computer-readable storage mediums (e.g. RAM, hard disk, optical/magnetic media, etc.).

[0040] Sensors 540 and 562 can be protected by suitable coatings such as diamond like coating (DLC), sapphire or spinel. Trunk line 568 can be protected within the core of valve and valve stem 560 and through a central hole of the valve and in any intermediate connectors such as dielectric separator tubes to provide attachment to the piezoelectric actuator 502 for connection to

microprocessor/controller 510. This ruggedized mechanical and electrical protection or isolation by effective layers of insulation enables extremely rapid adaptive optimization of each injector 500 along with the operation of each combustion chamber 542 (Fig. 5B).

[0041] Valve 560 may be returned to the normally closed position by closing means such as relaxation of elastomeric stress and/or spring that returns the attached piezoelectric stack assembly to the closed position and/or valve 560 may be returned to the normally closed position by another suitable spring such as a mechanical spring or a magnet. The stack operating cycle including the change in capacitance through the operating events and/or the strain indicated by piezoelectric layer such as aluminum nitride can be monitored by sensors to provide adaptive control of injection and/or ignition events. In certain applications, the voltage pulse generated by a change in stack capacitance upon closing may be utilized to trigger capacitance discharge for Lorentz ion thrusting and/or corona ignition events within the chamber 542. In certain applications the medium near or contacting the piezoelectric stack actuator 502 can be a hermetically sealed atmosphere including transformer oils such as polydimethylsiloxane, a paraffinic gas, liquid or solid, SF6, C4F8, on or near the piezoelectric stack assembly within the canister or bellows around 502 and may include one or more constituents that perform thermal energy transfer processes. One example of a thermal energy transfer process may include condensation on the cool surfaces of the bellows and evaporation on warmer surfaces of the piezoelectric stack assembly and vice versa depending upon the temperatures of the component zones. In some embodiments, a bellows is utilized to present a greater surface area per stack length to further enhance heat transfer to a fluid such as water coolant and/or fuel that may occasionally or cyclically flow past the outside surface of 502 or related components or other selected surfaces and passageways. Additional constituents of such hermetically sealed atmosphere may include selections such as hydrogen and/or helium to reduce the effective viscosity and/or to increase heat transfer capacity and/or surface protection constituents such as corrosion inhibitors and/or higher dielectric strength substances such as sulfur hexafluoride, methylpolysiloxane, FR 3 transformer fluid, silicone dielectric fluid, C 2 F 6 ,

[0042] One or more pressurized fluid fuel selections that are delivered to connections such as 514 and 516 may be selected by a suitable valve such as shuttle valve 508 (Fig. 5A) which is positioned by a suitable actuator such as pneumatic, hydraulic, solenoid, magnetostrictive or piezoelectric actuator assembly 51 9 (Fig. 5E) which may provide amplified motion of lever 522 across fulcrum bearing 520 to force lever 518 to shift valve 508 in assembly 521 . Thus, the selected fuel which may be the same or another substance and/or delivered at another temperature is delivered through one of selected parallel conduits such as 506 to flow through or around the outside canister such as a cylindrical capsule or hermetically sealed bellows of piezoelectric actuator assembly 502. The selected fuel is then delivered past the valve stem linkage assembly 505 of outward opening valve 560 (Fig. 5C).A s shown in Figures 4C and 5A, fluid selections that may be utilized as coolants including phase change cooling can be selected to flow through a conduit 506 that is coaxial or parallel to straight or curvilinear passageways such as 507 in hermetic sealed systems and/or through the annular clearance between the trunk line 404 and the bore of the stack assembly in open flow embodiments to provide cooling of the stack assembly of the piezoelectric actuator assembly 502.

[0043] With reference to Figure 5D, some fuel injector embodiments provide integrated functions of fuel injection and ignition upon one or more actuations by piezoelectric assembly 502. In such embodiments, fuel may flow past valve 560 and the valve seat) of component 556 through one or more passageways 550 into the annular space between electrode features 552 and 548. An initial small current may be developed between electrode features 552 and 548 that is thrust by Lorentz force toward the combustion chamber 542 as additional current ions are added by continued application of adaptively adjusted voltage, typically between 0 and 500V. Controller 51 0 may execute tangible computer-executable instructions to adaptively adjust the voltage magnitude to control the current and acceleration of the fuel flow into the combustion chamber 542. Suitable adjustments of applied voltage for such adaptive control range from about 1 0V DC to about 500V DC as needed for compensation of thermal expansion-contraction of the related components, fuel flow and combustion characteristics, piston speed and engine load, depending upon the application parameters. Thus, fuel flowing from passageways 550 at a controlled pressure and velocity such as subsonic up to sonic velocity is accelerated by control of the voltage applied to electrodes 546- 564 and 534-548 and the current that is thus developed. [0044] One or more permanent or electromagnets 570A, 570B and/or 570C may be disposed on a front end of the valve 560 to control the included angle of fuel that is launched as conical rays or sheets from the coaxial nozzle 563 (Fig. 6) formed by electrodes 546 and 548 (Fig. 5D). In certain applications, electrode 548 is shortened or eliminated in the region of the fuel injector port into the combustion chamber 542 to provide higher flow capacity and fuel rates.

[0045] In other applications, the shape of electrode 546 and features such as helical splines 564 (see, e.g., Fig. 5B & 5C) and/or flow deflectors such as 546 are provided along with magnetic lens 564 that may be created by adaptive control of electromagnetic windings 570 (Fig. 5C and 5D) and/or 574 (Fig. 5F) to enable a large variety of included angles for injected fuel plumes. Certain applications of such magnetic lens utilize high temperature windings 574 such as anodized titanium, stainless steel, refractory metal wires or oriented carbon nanofibers in a suitably collected and condensed wire bundle. Inducing one or more currents in one or more insulated electromagnetic circuits or windings may be provided by connection to suitably insulated conductor filaments in the trunk line bundle 568 that is routed through central passageway 156 (Fig. 2B), through any tubular dielectric connector, and through the tubular valve stem that extends before and after the head of valve 560 to one or more windings 574. Insulation for such high temperature windings includes ceramics, glass, glass-ceramics, boron nitride, and DLC. Further protection may be provided by a suitable spinel, silicon nitride, silicon nitride-aluminum oxide solid solution, zirconia, sapphire or alumina plate 572.

[0046] The distance valve 560 moves from valve seat may be monitored by various selections of sensors such as electrically conductive filaments, light pipes and/or other sensors. In some embodiments, a sensor 562 may include fiber- optics that may include suitably conditioned measurements of capacitance, magnetic permeability, reluctance, and/or optical events. Illustratively, one of the exemplary valve motion detection systems that may be utilized with or without other cooperative sensors is provided by light transmitting sources along with reflected light collecting pipes or fibers to provide a variable intensity signal that is proportional to the open gap produced by piezoelectric driven valve motion. The collected light signal may be converted to electrical voltage and/or current by a suitable transducer such as a semiconductor device. One or more such transducers may be located near the valve gap or at another location such as at or near the microprocessor 510 (Figure 5A) to provide for closed loop adaptive control of valve actuation voltage and thus enable compensation for thermal expansion or contraction to assure valve operation fidelity.

[0047] In some embodiments, an electrical field pulse is produced by energizing a suitable configuration of electrode 546 sufficiently rapidly to produce corona discharge in the combustion chamber 542. Such rapid application of a corona discharge in combustion chamber 542 may be cyclic by pulsed DC voltage at an adaptively determined frequency voltage or by AC voltage at suitable frequency such as by radio frequency RF. Trunk line 568 may include conductive filaments that induce such corona discharge or may include signal fibers such as fiber optics that trigger suitable circuits to provide capacitive discharge to produce Lorentz ion currents that are launched into the combustion chamber and/or one or more corona discharges into the combustion chamber including corona discharges in the pattern of Lorentz thrust ions. Selected piezoelectric stack capacitors and/or capacitors in zones such as 530, 531 , 532, and dielectric 566 located in embodiment 500 for such purposes may be charged by one or more selections of inductor-transformers 526A- M and/or discharged through conductor 528 to 556 to produce such events according to adaptive timing by a suitable processor such as microcontroller 510. Such events may produce desired acceleration of initiation and/or completion of combustion to provide improvements in brake mean effective pressure or BMEP in each combustion chamber 542 that is served by embodiment 500.

[0048] Another embodiment of the present invention is for the electrodes 546, 564, 548 (Figure 5B) and 552 (Figure 5C & 5D) for the piezoelectric actuator to be provided with patterns of conductive contacts such as may be located and retained by injection molded dielectric to form a region of trunk line 568 (Figure 5C & 5D) and/or plated or printed onto the surface of the trunk line with respect to enabling electrical contacts with selected conductive fibers 124, 126, 128, or 1 30 as shown in Figure 4C. In this way, a type of flex circuit or array is produced in which individual piezoelectric layers or groups of piezoelectric layers can be controlled discretely such as by adaptively selected combinations of contacts. This gives another level of fidelity for control of the actuator by not only being able to vary the voltage applied to each layer 1 02, but also the number of layers to which the voltage is applied. In some applications, the energy storage capacitances of various layer selections of the piezoelectric actuator are used directly or through one or more transformers such as selected voltage inductor-transformers 526A-526M and/or capacitors in zones such as 530, 531 (Fig. 5F) and 532 (Fig. 5B) and/or other regions of system5 00 for the Lorentz and/or corona ignition systems. This enables rapid discharges from the actuator to the ignition electrodes for selected magnitudes of capacitances according to the selected number of piezoelectric layers to be energized and discharged to Lorentz and/or corona electrodes.

[0049] In some embodiments, radiation of suitable frequency such as ionizing or nearly ionizing UV is generated by components incorporated within or on dielectric 566 or transmitted through the trunk line 568 from suitable sources such as a mercury plasma tube, laser, or UV emitting solid-state devices such as LEDs or transistors including nanotube devices to produce a pattern of radiation 576 (Figure 5F) to stimulate oxidant and or fuel particles to generate ions or to serve as the pattern in which corona discharge ionization occurs. This pattern may be disposed to intersect sensors or antenna components in one or more combustion chamber inserts (not shown) such as may be illustratively incorporated within or integrated with the head gasket of a combustion chamber. Thus, electromagnetic lensing using the components described in relation to Figure 5F may shape the travel of oxidant and/or fuel ions in patterns that are stimulated by such radiation to accelerate initiation and/or completion of combustion events. Trunk line 568 data transmission from the valve opening sensors and combustion chamber event sensors is conveyed to microprocessor 510 to adaptively adjust the fuel pressure, injection timing, Lorentz ion thrusting and pattern, ion generating radiation and pattern, and/or corona induced ion formation.

[0050] Illustratively, Figure 6 shows an end view of nozzle 563 of a partial section of the fuel injection device 500 facing the combustion chamber 542. Electrode 548 may incorporate substances with magnetic properties including materials that provide soft and/or hard magnetism and/or permanent magnetism and/or that are electromagnets in any particular combination, pattern or arrangement. Similarly electrode 556 and/or valve 560 can incorporate substances with magnetic properties including materials that provide soft and/or hard magnetism and/or permanent magnetism and/or that are electromagnets in any particular combination, pattern or arrangement. In operation this enables stimulation of forces that initiate, accelerate, bend, or otherwise modify ion currents that are produced between electrode 556, features such as 552 and 546 and electrode 548 to enhance Lorentz force production and/or to provide variable magnetic lens operation as depicted by flux patterns 564 to adaptively modify the pathways and patterns of ions that are thrust into combustion chamber 542.

[0051] PIEZOELECTRIC ACTUATOR MANUFACTURING PROCESS

[0052] Figure 7shows an exemplary manufacturing process 700 including a plurality of steps for producing a multilayer piezoelectric actuator and/or transducer systems such as disclosed herein. Various piezoelectric material compositions including selection such as PZT formulas, AIN along with glass, ceramic, or polymer selections such polyvinylidene fluoride are processed by steps 702-724 and integrated into subsystems to create a piezoelectric actuator as shown. At step 702, a slurry 702A is created for the PZT layers. In some embodiments, the slurry includes PZT powder, binder, plasticizer, de-agglomerate (i.e., dispersant), and a pH modifier. At step 704, the slurry 702A is tape cast through a doctor blade 704A to create a tape of PZT material. At step 706, the tape goes through a drying process to form "green tape." At step 708, the tape may be cut into blanks of various sizes, depending on the desired form of the PZT actuator. At step 71 0, electrodes 71 OA (e.g., the electrodes 104 of Figures 1 B, 2A, 2B, 3A, 3B, 4A, 4C, and 4D) may be screen printed onto green PZT tape 710B. In some embodiments, the electrodes are screen printed from copper paste. In further embodiments, the electrodes run continuously along the border of the piezoelectric stack, as shown at element 71 OA. At step 712, PZT blanks with printed electrodes 712A may be stacked and laminated by heat and pressure to form green laminated preforms 712B.A t step 714, green laminated preforms 712B are co-fired in a controlled atmosphere. In some embodiments, the co-firing is at <1000° C and the atmosphere is very tightly controlled to keep any copper from oxidizing and the PZT material from reducing. At step 716, dense multilayers of PZT material may be cut into final dimensions and stacked to actuator height. At step 718A, external positive and negative electrodes may be applied to each PZT stack. The external electrodes are isolated between the positive and negative layers of the PZT stack. At step 718B, a center hole may be cut through each of the PZT stacks. At step 720, each electrode may be etched back from the edge of the stack and at step 722, outer electrodes may be applied. At step 724, optical fiber may be added through the center hole cut into the stack at step 71 8B.

[0053] In certain embodiments, trunk line 568 is provided with tape cast and co- fired stacks of insulators such as polymers, glass, or ceramics and electrical contacts such as nickel, precious metal selections, cobalt, aluminum or copper in patterns that are connected to centralized conductor filaments that are components of circuits controlled by a suitable microprocessor such as 51 0 to actuate selected circuits for piezoelectric actuation, serve as instrumentation transducers, and/or to provide energy conversion with adaptively timed capacitance energy storage and discharge for operation of systems such as shown in Figures 5A-5F. In addition to co-firing, some embodiments provide progressive heat treating in which the process furnace atmosphere is varied in chemistry and/or temperature and/or pressure to provide the desired performances of conductive, piezoelectric, and/or insulating components. Suitable process furnaces include batch or continuous conversion types for providing progressive thermal, radiation and/or controlled atmosphere treatments. In some embodiments precursor sol-gel preparations are provided as deposited recipes that are converted to the respective outcomes as piezoelectric, conductive, or insulating components and/or such precursors may be utilized for specific pattern

developments and/or for integration of subsystems.

[0054] The technology described in the context of particular embodiments (e.g., the various "assemblies") may be combined or eliminated in other embodiments. For example, the electrode conductors 1 08, 1 10 or the armature 1 22 may or may not include the AIN thin film described above. Also, the various assemblies may or may not include the various described components within the central hole 1 56. Further, while advantages associated with certain elements of the various embodiments or assemblies of the technology have been described in the context of those

embodiments or assemblies, the other embodiments or assemblies may also exhibit such advantages, and not all embodiments or assemblies need necessarily exhibit such advantages to fall within the scope of the present disclosure. Also, unless the meaning is clearly to the contrary, all ranges set forth herein are deemed to be inclusive of the endpoints.