WO2005067071A1 - Piezoelectric actuator structure of piezoelectric ceramics having laminated ceramic actuating layer and fabrication method thereof - Google Patents

Piezoelectric actuator structure of piezoelectric ceramics having laminated ceramic actuating layer and fabrication method thereof Download PDF

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Publication number
WO2005067071A1
WO2005067071A1 PCT/KR2004/000578 KR2004000578W WO2005067071A1 WO 2005067071 A1 WO2005067071 A1 WO 2005067071A1 KR 2004000578 W KR2004000578 W KR 2004000578W WO 2005067071 A1 WO2005067071 A1 WO 2005067071A1
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piezoelectric
laminated
panels
metal electrodes
metal
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PCT/KR2004/000578
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French (fr)
Inventor
Kwang Joon Yoon
Hoon Cheol Park
Nam Seo Goo
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Konkuk University
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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/50—Piezoelectric or electrostrictive devices having a stacked or multilayer structure
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/01—Manufacture or treatment
    • H10N30/05—Manufacture of multilayered piezoelectric or electrostrictive devices, or parts thereof, e.g. by stacking piezoelectric bodies and electrodes
    • H10N30/057—Manufacture of multilayered piezoelectric or electrostrictive devices, or parts thereof, e.g. by stacking piezoelectric bodies and electrodes by stacking bulk piezoelectric or electrostrictive bodies and electrodes
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/01—Manufacture or treatment
    • H10N30/08—Shaping or machining of piezoelectric or electrostrictive bodies
    • H10N30/085—Shaping or machining of piezoelectric or electrostrictive bodies by machining
    • H10N30/088—Shaping or machining of piezoelectric or electrostrictive bodies by machining by cutting or dicing

Definitions

  • the present invention relates to a- laminated ceramic actuation layer structure made of piezoelectric ceramics and a fabrication method thereof, and more particularly, to a piezoelectric actuator structure made of piezoelectric ceramics having a laminated ceramic actuation layer, in which actuation electrodes are formed alternatively between the laminated piezoelectric ceramics and positive and negative poles of the actuation electrodes are arranged alternating with each other so that terminal ends of the electrodes can be powered via conductive epoxy so as to enhance piezoelectric constant d 33 actuation effect .
  • High performance piezoelectric actuators are generally used in control blocks of aircrafts and missiles, actuation sections of robots and vibration-control blocks of large-sized space structures. Recently, various researches have been carried out to improve the performance of the piezoelectric actuators. Since piezoelectric ceramics exert small actuation displacement owing to very low maximum modulus of strain, piezoelectric ceramic actuators made of piezoelectric ceramic sheets are under development in various forms .
  • RAINBOW Reduced And Internally Biased Oxide Wafer
  • TUNDER Thin layer composite Unimorph feroelectric DrivER and sensor
  • AFC Active Fiber Composite
  • LaRC-MFCTM Langley Research Center Macro-Fiber Composite
  • LIPCA Lightweight Piezo-Composite Actuator
  • LIPCA is issued as Korean Patent Registration No .10-0401808 , entitled for "Curved Surface Actuator Comprising Piezoelectric Material Layer and Fiber Composite Layer.” All of RAINBOW, THUNDER and LIPCA actuator can be referred to as composite structures based upon the actuation principle of piezoelectric constant d 3i .
  • piezoelectric constant d 31 indicates the degree of elongation in x-axial direction (first direction) in application of an electric field in z-axial direction (third direction) .
  • piezoelectric constant d 33 indicates the degree of elongation in z-axial direction (third direction) in application of an electric field in x- axial direction (first direction) .
  • Table 1 below compares piezoelectric constants d 31 and d 33 of piezoelectric ceramics available from CTS of the United States. It can be understood that the performance of an actuator can be improved by utilizing piezoelectric constant d 33 because d 33 is larger than d 3i about twice. On that basis, laminated ceramic actuators were developed at a thickness of at least lmm to utilize piezoelectric constant d 33 effect. However, these actuators have problems in fabrication since all of unit actuation layers are prepared to have the same width as designed actuation layers and then laminated one atop another to form the actuators . Table 1
  • the present invention has been made to solve the foregoing problems of the prior art . It is therefore an object of the present invention to provide a laminated ceramic actuation layer capable of forming actuation electrodes between laminated ceramic layers to maximize d 33 actuation effect, and a fabrication method for efficiently fabricating a laminated ceramic actuator from such laminated ceramic actuation layer.
  • a piezoelectric actuator structure made of piezoelectric ceramics having a laminated ceramic actuation layer comprising: a plurality of bar-shaped piezoelectric ceramics each having a first metal electrode coated on a top surface of a piezoelectric ceramic panel and a second metal electrode coated on a bottom surface of the piezoelectric ceramic panel, the first and second metal electrodes being coated to such extents that the top and bottom surfaces are partially exposed to form first and second etched portions, the second metal electrodes being located opposite in direction to the first metal electrodes, the piezoelectric ceramics being laminated one atop another to have alternating poling directions; and positive and negative sheet metal electrodes bonded to both ends of the laminated piezoelectric ceramics, wherein the piezoelectric ceramics are alternatively laminated so that the positive and negative sheet metal electrodes alternate with each other while being electrically and perpendicularly connected with terminal ends of the first and second metal electrodes.
  • a piezoelectric actuator structure made of piezoelectric ceramics having a laminated ceramic actuation layer comprising: a plurality of bar-shaped piezoelectric ceramics each having a metal electrode coated on a top surface of a piezoelectric ceramic panel, the metal electrode being coated to such an extent that the top surface is partially exposed to form an etched portions, the piezoelectric ceramics being laminated one atop another to have alternating poling directions; and positive and negative sheet metal electrodes bonded to both ends of the laminated piezoelectric ceramics, wherein the piezoelectric ceramics are alternatively laminated so that the positive and negative sheet metal electrodes alternate with each other while being electrically and perpendicularly connected with terminal ends of the first and second metal electrodes.
  • a fabrication method of a piezoelectric actuator made of piezoelectric ceramics comprising the following steps of: (a) forming a plurality of first piezoelectric panels each having a first metal electrode coated on a top surface of a piezoelectric ceramic panel and a second metal electrode coated on a bottom surface of the piezoelectric ceramic panel, the first and second metal electrodes being coated to such extents that the top and bottom surfaces are partially exposed to form first and second etched portions, the second metal electrodes being located opposite in direction to the first metal electrodes; (b) alternating a plurality of second piezoelectric panels with the first piezoelectric panels, the second piezoelectric panels being configured symmetric with the first piezoelectric panels, and fixing the first and second piezoelectric panels with an epoxy adhesive to form a laminated piezoelectric ceramic structure of a predetermined size; (c) bonding positive and negative metal sheet electrodes to both lateral portions of the laminate
  • a fabrication method of a piezoelectric actuator made of piezoelectric ceramics comprising the following steps of: (a) forming a plurality of first piezoelectric panels each having a first metal electrode coated on a top surface of a piezoelectric ceramic panel and a second metal electrode coated on a bottom surface of the piezoelectric ceramic panel, the first and second metal electrodes being coated to such extents that the top and bottom surfaces are partially exposed to form first and second etched portions, the second metal electrodes being located opposite in direction to the first metal electrodes; (b) alternating a plurality of second piezoelectric panels with the first piezoelectric panels, the second piezoelectric panels being configured symmetric with the first piezoelectric panels, and fixing the first and second piezoelectric panels with an epoxy adhesive to form a laminated piezoelectric ceramic structure of a predetermined size; (c) cutting the laminated piezoelectric ceramic structure into a laminated piez
  • the fabrication method may further comprise the step of polishing both lateral portions of the laminated piezoelectric ceramic sheet after the step (b) .
  • the conductive epoxy is mixed with silver powder.
  • a fabrication method of a piezoelectric actuator made of piezoelectric ceramics comprising the following steps of: (a) forming a plurality of first piezoelectric panels each having a first metal electrode coated on a top surface of a piezoelectric ceramic panel and a second metal electrode coated on a bottom surface of the piezoelectric ceramic panel, the first and second metal electrodes being coated to such extents that the top and bottom surfaces are partially exposed to form first and second etched portions, the second metal electrodes being located opposite in direction to the first metal electrodes; (b) plating both lateral portions of the first piezoelectric ceramic panels to form positive and negative metal sheet electrodes electrically connected with the first or second metal electrodes; (c) alternating a plurality of
  • FIG. 1 is a partial perspective view illustrating the structure of a piezoelectric actuator according to the present invention
  • FIG. 2 is a flowchart illustrating a method of fabricating a piezoelectric actuator according to the present invention
  • FIG. 3 illustrates a fabrication process of first and second piezoelectric ceramic panels and the coupling relation thereof according to the present invention
  • FIG. 4 is a perspective view of a laminated piezoelectric ceramic structure according to the present invention
  • FIG. 5 illustrates a process of fabricating a piezoelectric actuator by cutting a laminated piezoelectric ceramic structure according to the present invention
  • FIG. 1 is a partial perspective view illustrating the structure of a piezoelectric actuator according to the present invention
  • FIG. 2 is a flowchart illustrating a method of fabricating a piezoelectric actuator according to the present invention
  • FIG. 3 illustrates a fabrication process of first and second piezoelectric ceramic panels and the coupling relation thereof according to the present invention
  • FIG. 4 is a perspective view of
  • FIG. 6 illustrates a test structure for inspecting the actuation strain performance of a piezoelectric actuator
  • FIG. 7 is a graph illustrating experimental results and linear analysis expectancies to a plurality of specimens
  • FIG. 8 is a graph comparing the modulus of strain of piezoelectric constant d 3i with that of piezoelectric constant d 33
  • FIG. 9 is a graph comparing actuation strain performances between a piezoelectric actuator according to the present invention and a LaRC-MFCTM.
  • FIG. 1 is a partial perspective view illustrating the structure of a piezoelectric actuator made of piezoelectric ceramics having laminated ceramic actuator films according to the present invention.
  • a piezoelectric actuator 100 includes a number of bar-shaped piezoelectric ceramics 101 laminated one atop another and metal electrodes 103 coated on top and bottom surfaces of the piezoelectric ceramics 101.
  • Both the positive electrodes 105 and negative electrodes 109 are bonded to the alternating terminal ends of the metal electrodes 103 preferably via a conductive epoxy mixed with silver powder. Both sides of the piezoelectric actuator 100 can be polished to raise bonding ability. The etched portions 107 prevent electric transmission between the positive electrode 105 and the negative electrode 109, and the magnitude thereof can be varied according to the size and use of the piezoelectric actuator 100.
  • the piezoelectric actuator 100 formed as above is provided with electric signals via the positive and negative electrodes 105 and 109 bonded to the both sides of the actuator 100, and the electric signals are provided to the alternating metal electrodes 103 of the piezoelectric ceramics 101 to bring piezoelectric effect corresponding to the electric signals.
  • Equation 1 In application of supply voltage to a film-shaped piezoelectric actuator, strain will be expressed as Equation 1 : Equation 1, herein t a indicates the thickness of the piezoelectric actuator, ⁇ v indicates the magnitude of supply voltage applied to the piezoelectric actuator.
  • the piezoelectric actuator according to the present invention has strain values based upon Equation 1 as reported in Table 2 below. Table 2 reports strain values obtained by increasing supply voltage to 600V/mm by lOOV/mm, with a piezoelectric ceramics having a thickness of 0.5mm. Table 2
  • FIG. 2 is a flowchart illustrating a fabrication method of a piezoelectric actuator according to the present invention
  • FIGS. 3 to 5 illustrate main process steps of the fabrication method of the present invention.
  • S201 metal (Ni) electrode panels attached to top and bottom surfaces of a piezoelectric ceramic sheet of a predetermined size are etched partially in peripheries to remove corresponding portions of the metal (Ni) electrode panels.
  • the metal electrode attached to the top surface of the piezoelectric ceramic sheet is partially removed in one periphery with FeCl 3 and the metal electrode attached to the bottom surface of the piezoelectric ceramic sheet is also partially removed in other periphery with FeCl 3 , as shown in FIG.
  • etching lines 307 in the top and bottom surfaces of the piezoelectric ceramic sheets opposed to each other.
  • the piezoelectric ceramic sheet is fabricated into a first piezoelectric ceramic panel 301 having a first metal electrode panel 305 formed on the top surface and a second metal electrode panel 309 on the bottom surface.
  • the etching lines 307 function to prevent any short-circuit between the first and second metal electrode panels 305 and 309 when the conductive epoxy is bonded to sides of a number of laminated piezoelectric ceramic panels, and are preferably formed with a width of about 1mm.
  • First piezoelectric ceramic panels 301 formed as above are fabricated by a large amount.
  • second piezoelectric ceramic panels 303 are configured symmetric with and turned by 180 degree from the first piezoelectric ceramic panels 301.
  • the first and second piezoelectric ceramic panels 301 and 303 are bonded together.
  • This bonding step is performed using an epoxy adhesive so that the first and second ceramic panels 301 and 303 are laminated to alternate with each other. That is, the piezoelectric ceramic panels 301 and 303 are so laminated that poles are directed opposite alternatively. Therefore, the first metal electrode panel 309 in the bottom surface of the first piezoelectric ceramic panel 301 is bonded to the first metal electrode panel 305 in the top surface of the second piezoelectric ceramic panel 303.
  • FIG. 4 illustrates a laminated piezoelectric ceramic structure 401 formed by stacking the piezoelectric ceramic panels 301 and 303, in which the second metal electrode panel 309 is bonded with the first metal electrode panel 305. While the first and second piezoelectric ceramic panels 301 and 303 are provided with the first and second metal electrode panels 305 and 309 in their top and bottom surfaces so that electric signals are provided via the metal electrode panels according to the present invention, metal electrode panels may be formed in other sides of the laminated piezoelectric ceramic structure without departing from the scope of the present invention. That is, a metal electrode panel and an etching line are formed on a top surface of a piezoelectric ceramic panel with a bottom surface thereof maintained without forming the metal electrode panel.
  • Such piezoelectric ceramic panels are laminated on atop another in an alternating fashion though bonding of the piezoelectric ceramic panels using a conductive epoxy to the metal electrode panels and a non- conductive epoxy to the etching lines. Therefore, one piezoelectric ceramic panel electrode utilizes the metal electrode panel formed in the top surface of a first piezoelectric ceramic panel, and the other piezoelectric ceramic panel electrode utilizes the metal electrode panel formed in the bottom surface of a second piezoelectric ceramic panel laminated under the first piezoelectric ceramic panel . Such structure reduces manufacturing cost of a laminated piezoelectric ceramic structure.
  • S205 after curing the epoxy adhesive dispensed between the piezoelectric ceramic panels, as shown in FIG.
  • the laminated piezoelectric ceramic structure 401 is cut along its cross sections into laminated piezoelectric ceramic sheets functioning as actuation layers.
  • the laminated piezoelectric ceramic structure 401 is cut with a precision cutter using a diamond wheel to a predetermined thickness of about 0.2mm or 0.5mm if necessary.
  • the reference numeral 505 designates a cross section of the laminated piezoelectric ceramic structure 401 cut by the precision cutter.
  • lateral portions of a laminated piezoelectric ceramic sheet of the predetermined thickness are polished into smooth planes and electrodes are formed on the lateral portions by bonding the conductive epoxy mixed with silver powder to main electrode lines of the laminated piezoelectric ceramic sheet to form a piezoelectric actuator 100 as shown in FIG. 1.
  • the piezoelectric actuator 100 has positive and negative metal sheet electrodes 105 and 109 bonded to both sides so that electric signals for actuation of piezoelectric ceramics are applied through the respective sheet meal electrodes 105 and 109. While the positive and negative sheet metal electrodes 105 and 109 are bonded to both lateral portions of the laminated piezoelectric ceramic sheet with the conductive epoxy, the lateral portions of the laminated piezoelectric ceramic sheet can be plated with a conductive material to form metal electrodes without departing from the scope of the present invention. Also, plating layers may be formed in both lateral portions of the piezoelectric ceramic panels in fabrication of the first and second sheet metal electrodes 305 and 305 of the piezoelectric ceramic panels.
  • the conductor-plated layers formed in the both lateral portions are electrically connected with the first and second electrodes 305 and 309. Therefore, main electrode lines are bonded (or soldered) to the plated lateral portions of the actuation sheet to form electrode lines without additionally bonding the conductive epoxy.
  • the cutting step S205 and the electrode forming step S207 may be changed in their orders.
  • FIG. 6 illustrates a test structure for inspecting the actuation ' strain performance of a piezoelectric actuator.
  • a strain gauge is attached to a side of the piezoelectric actuator used as a specimen and a power supply (not shown) for supplying DC supply voltage is connected to both sides of the specimen.
  • a strain indicator (not shown) for measuring signals from the strain gauge and a voltmeter (not shown) for measuring the DC supply voltage are cooperatively provided.
  • the DC supply voltage was raised by predetermined levels with this test structure to measure the variation of actuation strain in the piezoelectric actuator. During experiment, domain switching was observed at about 700V/mm and the DC supply voltage was raised to about 600V/mm.
  • Experimental results and linear analysis expectancies for 4 specimens are reported in FIG. 7. While the experimental results are similar to the linear analysis expectancies in an earlier stage, there are large differences of about 40% between the experimental results and the linear analysis expectancies. The experimental results show large differences from the expectancies in higher electric fields because a.
  • piezoelectric constant d 33 provided from a product company is data measured in a relatively low voltage range and thus changes non-linearly by large values when the supply voltage approaches the domain switching voltage.
  • FIG. 8 compares the modulus of strain of piezoelectric constant d 31 with that of piezoelectric constant d 33 . It was observed that an actuation layer using piezoelectric constant d 33 has an actuation strain performance at least 50% larger than that of another one using piezoelectric constant d 3x . This means that the d 33 actuation effect can be at least one half of the d 31 actuation effect.
  • the performance of the actuation layer was compared with the actuation strain performance of LaRC-MFCTM, known as the most excellent one of ceramic actuation layers which have been developed up to the present, in order to more objectively compare the performance of the actuation layer of the invention.
  • the result of comparison is reported in FIG. 9.
  • the actuation strain of an IDEAL specimen of the invention was larger than that of LaRC-MFCTM for about 10% at electric fields up to 300V/mm and for about 25% at electric fields up to 600V/mm. This shows that the insertion IDE electrode structure has a d 33 actuation effect superior to that of a surface IDE electrode structure.
  • the piezoelectric actuator made of piezoelectric ceramics having a laminated ceramic actuation layer proposes a policy of laminating and bonding unit panels one atop another to a designed thickness and slicing the panels into sheets to provide an IDEAL which adopts an insertion IDE electrode structure to maximize d 33 actuation effect.

Abstract

Disclosed is a laminated ceramic actuator structure made of piezoelectric ceramics having a laminated ceramic actuation layer and a fabrication method thereof. The piezoelectric actuator structure comprises: a plurality of bar-shaped piezoelectric ceramics each having a first metal electrode coated on a top surface of a piezoelectric ceramic panel and a second metal electrode coated on a bottom surface of the piezoelectric ceramic panel, the first and second metal electrodes being coated to such extents that the top and bottom surfaces are partially exposed to form first and second etched portions, the piezoelectric ceramics being laminated one atop another to have alternating poling directions; and positive and negative sheet metal electrodes bonded to both ends of the laminated piezoelectric ceramics, wherein the piezoelectric ceramics are alternatively laminated.

Description

PIEZOELECTRIC ACTUATOR STRUCTURE OF PIEZOELECTRIC CERAMICS HAVING LAMINATED CERAMIC ACTUATING LAYER AND FABRICATION METHOD THEREOF
Technical Field
The present invention relates to a- laminated ceramic actuation layer structure made of piezoelectric ceramics and a fabrication method thereof, and more particularly, to a piezoelectric actuator structure made of piezoelectric ceramics having a laminated ceramic actuation layer, in which actuation electrodes are formed alternatively between the laminated piezoelectric ceramics and positive and negative poles of the actuation electrodes are arranged alternating with each other so that terminal ends of the electrodes can be powered via conductive epoxy so as to enhance piezoelectric constant d33 actuation effect .
Background Art
High performance piezoelectric actuators are generally used in control blocks of aircrafts and missiles, actuation sections of robots and vibration-control blocks of large-sized space structures. Recently, various researches have been carried out to improve the performance of the piezoelectric actuators. Since piezoelectric ceramics exert small actuation displacement owing to very low maximum modulus of strain, piezoelectric ceramic actuators made of piezoelectric ceramic sheets are under development in various forms . Representative examples of such researches and developments may include Reduced And Internally Biased Oxide Wafer (RAINBOW) , Thin layer composite Unimorph feroelectric DrivER and sensor (THUNDER) , Active Fiber Composite (AFC) developed by MIT in the United States, Langley Research Center Macro-Fiber Composite (LaRC-MFC™) from NASA and Lightweight Piezo-Composite Actuator (LIPCA) , developed by the inventors. LIPCA is issued as Korean Patent Registration No .10-0401808 , entitled for "Curved Surface Actuator Comprising Piezoelectric Material Layer and Fiber Composite Layer." All of RAINBOW, THUNDER and LIPCA actuator can be referred to as composite structures based upon the actuation principle of piezoelectric constant d3i . Herein piezoelectric constant d31 indicates the degree of elongation in x-axial direction (first direction) in application of an electric field in z-axial direction (third direction) . Whereas, piezoelectric constant d33 indicates the degree of elongation in z-axial direction (third direction) in application of an electric field in x- axial direction (first direction) . Table 1 below compares piezoelectric constants d31 and d33 of piezoelectric ceramics available from CTS of the United States. It can be understood that the performance of an actuator can be improved by utilizing piezoelectric constant d33 because d33 is larger than d3i about twice. On that basis, laminated ceramic actuators were developed at a thickness of at least lmm to utilize piezoelectric constant d33 effect. However, these actuators have problems in fabrication since all of unit actuation layers are prepared to have the same width as designed actuation layers and then laminated one atop another to form the actuators . Table 1
Figure imgf000004_0001
Although AFC developed by MIT and LaRC-MFC™developed by NASA Langley Research Team have instances of utilizing d33 actuation effect, they are rarely considered that d33 actuation effect is sufficiently utilized because electrodes are attached to top and bottom surfaces of an actuation layer and actuation strain performance is not as good as expected. As a result, there are problems that these techniques have a narrow range of use .
Disclosure of Invention
The present invention has been made to solve the foregoing problems of the prior art . It is therefore an object of the present invention to provide a laminated ceramic actuation layer capable of forming actuation electrodes between laminated ceramic layers to maximize d33 actuation effect, and a fabrication method for efficiently fabricating a laminated ceramic actuator from such laminated ceramic actuation layer. According to a first aspect of the present invention for realizing the object, there is provided a piezoelectric actuator structure made of piezoelectric ceramics having a laminated ceramic actuation layer comprising: a plurality of bar-shaped piezoelectric ceramics each having a first metal electrode coated on a top surface of a piezoelectric ceramic panel and a second metal electrode coated on a bottom surface of the piezoelectric ceramic panel, the first and second metal electrodes being coated to such extents that the top and bottom surfaces are partially exposed to form first and second etched portions, the second metal electrodes being located opposite in direction to the first metal electrodes, the piezoelectric ceramics being laminated one atop another to have alternating poling directions; and positive and negative sheet metal electrodes bonded to both ends of the laminated piezoelectric ceramics, wherein the piezoelectric ceramics are alternatively laminated so that the positive and negative sheet metal electrodes alternate with each other while being electrically and perpendicularly connected with terminal ends of the first and second metal electrodes. In particular, the positive and negative sheet metal electrodes are bonded to terminal ends of the alternating metal electrodes via a conductive epoxy mixed with silver powder . According to a second aspect of the present invention for realizing the object, there is provided a piezoelectric actuator structure made of piezoelectric ceramics having a laminated ceramic actuation layer comprising: a plurality of bar-shaped piezoelectric ceramics each having a metal electrode coated on a top surface of a piezoelectric ceramic panel, the metal electrode being coated to such an extent that the top surface is partially exposed to form an etched portions, the piezoelectric ceramics being laminated one atop another to have alternating poling directions; and positive and negative sheet metal electrodes bonded to both ends of the laminated piezoelectric ceramics, wherein the piezoelectric ceramics are alternatively laminated so that the positive and negative sheet metal electrodes alternate with each other while being electrically and perpendicularly connected with terminal ends of the first and second metal electrodes. According to a third aspect of the present invention for realizing the object, there is provided a fabrication method of a piezoelectric actuator made of piezoelectric ceramics, the method comprising the following steps of: (a) forming a plurality of first piezoelectric panels each having a first metal electrode coated on a top surface of a piezoelectric ceramic panel and a second metal electrode coated on a bottom surface of the piezoelectric ceramic panel, the first and second metal electrodes being coated to such extents that the top and bottom surfaces are partially exposed to form first and second etched portions, the second metal electrodes being located opposite in direction to the first metal electrodes; (b) alternating a plurality of second piezoelectric panels with the first piezoelectric panels, the second piezoelectric panels being configured symmetric with the first piezoelectric panels, and fixing the first and second piezoelectric panels with an epoxy adhesive to form a laminated piezoelectric ceramic structure of a predetermined size; (c) bonding positive and negative metal sheet electrodes to both lateral portions of the laminated piezoelectric ceramic structure having the etched portions via a conductive epoxy; and (d) after curing the conductive epoxy, cutting the laminated piezoelectric ceramic structure with the positive and negative metal sheet electrodes bonded thereto at a predetermined thickness. According to a fourth aspect of the present invention for realizing the object, there is provided a fabrication method of a piezoelectric actuator made of piezoelectric ceramics, the method comprising the following steps of: (a) forming a plurality of first piezoelectric panels each having a first metal electrode coated on a top surface of a piezoelectric ceramic panel and a second metal electrode coated on a bottom surface of the piezoelectric ceramic panel, the first and second metal electrodes being coated to such extents that the top and bottom surfaces are partially exposed to form first and second etched portions, the second metal electrodes being located opposite in direction to the first metal electrodes; (b) alternating a plurality of second piezoelectric panels with the first piezoelectric panels, the second piezoelectric panels being configured symmetric with the first piezoelectric panels, and fixing the first and second piezoelectric panels with an epoxy adhesive to form a laminated piezoelectric ceramic structure of a predetermined size; (c) cutting the laminated piezoelectric ceramic structure into a laminated piezoelectric ceramic sheet at a predetermined thickness; and (d) bonding positive and negative metal sheet electrodes to both lateral portions of the laminated piezoelectric ceramic sheet having the etched portions via a conductive epoxy. In particular, the fabrication method may further comprise the step of polishing both lateral portions of the laminated piezoelectric ceramic sheet after the step (b) . Preferably, the conductive epoxy is mixed with silver powder. According to a fifth aspect of the present invention for realizing the object, there is provided a fabrication method of a piezoelectric actuator made of piezoelectric ceramics, the method comprising the following steps of: (a) forming a plurality of first piezoelectric panels each having a first metal electrode coated on a top surface of a piezoelectric ceramic panel and a second metal electrode coated on a bottom surface of the piezoelectric ceramic panel, the first and second metal electrodes being coated to such extents that the top and bottom surfaces are partially exposed to form first and second etched portions, the second metal electrodes being located opposite in direction to the first metal electrodes; (b) plating both lateral portions of the first piezoelectric ceramic panels to form positive and negative metal sheet electrodes electrically connected with the first or second metal electrodes; (c) alternating a plurality of second piezoelectric panels with the first piezoelectric panels, the second piezoelectric panels being configured symmetric with the first piezoelectric panels, and fixing the first and second piezoelectric panels with an epoxy adhesive to form a laminated piezoelectric ceramic structure of a predetermined size; and (d) after curing the conductive epoxy, cutting the laminated piezoelectric ceramic structure with the positive and negative metal sheet electrodes bonded thereto at a predetermined thickness.
Brief Description of the Drawings
The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a partial perspective view illustrating the structure of a piezoelectric actuator according to the present invention; FIG. 2 is a flowchart illustrating a method of fabricating a piezoelectric actuator according to the present invention; FIG. 3 illustrates a fabrication process of first and second piezoelectric ceramic panels and the coupling relation thereof according to the present invention; FIG. 4 is a perspective view of a laminated piezoelectric ceramic structure according to the present invention; FIG. 5 illustrates a process of fabricating a piezoelectric actuator by cutting a laminated piezoelectric ceramic structure according to the present invention; FIG. 6 illustrates a test structure for inspecting the actuation strain performance of a piezoelectric actuator; FIG. 7 is a graph illustrating experimental results and linear analysis expectancies to a plurality of specimens; and FIG. 8 is a graph comparing the modulus of strain of piezoelectric constant d3i with that of piezoelectric constant d33; and FIG. 9 is a graph comparing actuation strain performances between a piezoelectric actuator according to the present invention and a LaRC-MFCTM.
Best Mode for Carrying Out the Invention Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings . FIG. 1 is a partial perspective view illustrating the structure of a piezoelectric actuator made of piezoelectric ceramics having laminated ceramic actuator films according to the present invention. As shown in FIG. 1, a piezoelectric actuator 100 includes a number of bar-shaped piezoelectric ceramics 101 laminated one atop another and metal electrodes 103 coated on top and bottom surfaces of the piezoelectric ceramics 101. The metal electrodes 103 is made of Ni , and removed in part by etching with FeCl3 from one ends for about 1mm to form etched portions 107 in the piezoelectric ceramics 101. Such piezoelectric ceramics 101 are laminated one atop another with poling directions alternating with each other. The piezoelectric actuator 100 has a positive electrode 105 made of a metal sheet arranged at one side and a negative electrode 109 made of a metal sheet arranged at the other side. The metal thin film is preferably made of Cu. The positive electrode 105 and the negative electrode 109 are electrically connected with terminal ends of the metal electrodes 103 which alternate with each other owing to the alternating structure of the piezoelectric ceramics 101. Both the positive electrodes 105 and negative electrodes 109 are bonded to the alternating terminal ends of the metal electrodes 103 preferably via a conductive epoxy mixed with silver powder. Both sides of the piezoelectric actuator 100 can be polished to raise bonding ability. The etched portions 107 prevent electric transmission between the positive electrode 105 and the negative electrode 109, and the magnitude thereof can be varied according to the size and use of the piezoelectric actuator 100. The piezoelectric actuator 100 formed as above is provided with electric signals via the positive and negative electrodes 105 and 109 bonded to the both sides of the actuator 100, and the electric signals are provided to the alternating metal electrodes 103 of the piezoelectric ceramics 101 to bring piezoelectric effect corresponding to the electric signals. In application of supply voltage to a film-shaped piezoelectric actuator, strain will be expressed as Equation 1 :
Figure imgf000011_0001
Equation 1, herein ta indicates the thickness of the piezoelectric actuator, Δv indicates the magnitude of supply voltage applied to the piezoelectric actuator. In the meantime, the piezoelectric actuator according to the present invention has strain values based upon Equation 1 as reported in Table 2 below. Table 2 reports strain values obtained by increasing supply voltage to 600V/mm by lOOV/mm, with a piezoelectric ceramics having a thickness of 0.5mm. Table 2
Figure imgf000011_0002
FIG. 2 is a flowchart illustrating a fabrication method of a piezoelectric actuator according to the present invention, and FIGS. 3 to 5 illustrate main process steps of the fabrication method of the present invention. In S201, metal (Ni) electrode panels attached to top and bottom surfaces of a piezoelectric ceramic sheet of a predetermined size are etched partially in peripheries to remove corresponding portions of the metal (Ni) electrode panels. The metal electrode attached to the top surface of the piezoelectric ceramic sheet is partially removed in one periphery with FeCl3 and the metal electrode attached to the bottom surface of the piezoelectric ceramic sheet is also partially removed in other periphery with FeCl3, as shown in FIG. 3, to form etching lines 307 in the top and bottom surfaces of the piezoelectric ceramic sheets opposed to each other. As a result, the piezoelectric ceramic sheet is fabricated into a first piezoelectric ceramic panel 301 having a first metal electrode panel 305 formed on the top surface and a second metal electrode panel 309 on the bottom surface. The etching lines 307 function to prevent any short-circuit between the first and second metal electrode panels 305 and 309 when the conductive epoxy is bonded to sides of a number of laminated piezoelectric ceramic panels, and are preferably formed with a width of about 1mm. First piezoelectric ceramic panels 301 formed as above are fabricated by a large amount. In S203, second piezoelectric ceramic panels 303 are configured symmetric with and turned by 180 degree from the first piezoelectric ceramic panels 301. The first and second piezoelectric ceramic panels 301 and 303 are bonded together. This bonding step is performed using an epoxy adhesive so that the first and second ceramic panels 301 and 303 are laminated to alternate with each other. That is, the piezoelectric ceramic panels 301 and 303 are so laminated that poles are directed opposite alternatively. Therefore, the first metal electrode panel 309 in the bottom surface of the first piezoelectric ceramic panel 301 is bonded to the first metal electrode panel 305 in the top surface of the second piezoelectric ceramic panel 303. FIG. 4 illustrates a laminated piezoelectric ceramic structure 401 formed by stacking the piezoelectric ceramic panels 301 and 303, in which the second metal electrode panel 309 is bonded with the first metal electrode panel 305. While the first and second piezoelectric ceramic panels 301 and 303 are provided with the first and second metal electrode panels 305 and 309 in their top and bottom surfaces so that electric signals are provided via the metal electrode panels according to the present invention, metal electrode panels may be formed in other sides of the laminated piezoelectric ceramic structure without departing from the scope of the present invention. That is, a metal electrode panel and an etching line are formed on a top surface of a piezoelectric ceramic panel with a bottom surface thereof maintained without forming the metal electrode panel. Such piezoelectric ceramic panels are laminated on atop another in an alternating fashion though bonding of the piezoelectric ceramic panels using a conductive epoxy to the metal electrode panels and a non- conductive epoxy to the etching lines. Therefore, one piezoelectric ceramic panel electrode utilizes the metal electrode panel formed in the top surface of a first piezoelectric ceramic panel, and the other piezoelectric ceramic panel electrode utilizes the metal electrode panel formed in the bottom surface of a second piezoelectric ceramic panel laminated under the first piezoelectric ceramic panel . Such structure reduces manufacturing cost of a laminated piezoelectric ceramic structure. In S205, after curing the epoxy adhesive dispensed between the piezoelectric ceramic panels, as shown in FIG. 5, the laminated piezoelectric ceramic structure 401 is cut along its cross sections into laminated piezoelectric ceramic sheets functioning as actuation layers. In this case, the laminated piezoelectric ceramic structure 401 is cut with a precision cutter using a diamond wheel to a predetermined thickness of about 0.2mm or 0.5mm if necessary. The reference numeral 505 designates a cross section of the laminated piezoelectric ceramic structure 401 cut by the precision cutter. In S207, lateral portions of a laminated piezoelectric ceramic sheet of the predetermined thickness are polished into smooth planes and electrodes are formed on the lateral portions by bonding the conductive epoxy mixed with silver powder to main electrode lines of the laminated piezoelectric ceramic sheet to form a piezoelectric actuator 100 as shown in FIG. 1. Therefore, the piezoelectric actuator 100 has positive and negative metal sheet electrodes 105 and 109 bonded to both sides so that electric signals for actuation of piezoelectric ceramics are applied through the respective sheet meal electrodes 105 and 109. While the positive and negative sheet metal electrodes 105 and 109 are bonded to both lateral portions of the laminated piezoelectric ceramic sheet with the conductive epoxy, the lateral portions of the laminated piezoelectric ceramic sheet can be plated with a conductive material to form metal electrodes without departing from the scope of the present invention. Also, plating layers may be formed in both lateral portions of the piezoelectric ceramic panels in fabrication of the first and second sheet metal electrodes 305 and 305 of the piezoelectric ceramic panels. In this case, the conductor-plated layers formed in the both lateral portions are electrically connected with the first and second electrodes 305 and 309. Therefore, main electrode lines are bonded (or soldered) to the plated lateral portions of the actuation sheet to form electrode lines without additionally bonding the conductive epoxy. In the fabrication method of a piezoelectric actuator made of piezoelectric ceramics having a laminated ceramic actuation layer according to the present invention, the cutting step S205 and the electrode forming step S207 may be changed in their orders. That is, both lateral portions of the laminated piezoelectric ceramic structure 401 are bonded with metal sheets of a corresponding size via the conductive epoxy, and then the laminated piezoelectric ceramic structure 401 is cut through the afore-described cutting step to fabricate a number of piezoelectric actuators 100. Hereinafter the piezoelectric actuator having a laminated ceramic actuation layer fabricated according to the invention has performance test results as follows: FIG. 6 illustrates a test structure for inspecting the actuation ' strain performance of a piezoelectric actuator. As shown in FIG. 6, a strain gauge is attached to a side of the piezoelectric actuator used as a specimen and a power supply (not shown) for supplying DC supply voltage is connected to both sides of the specimen. Then, a strain indicator (not shown) for measuring signals from the strain gauge and a voltmeter (not shown) for measuring the DC supply voltage are cooperatively provided. The DC supply voltage was raised by predetermined levels with this test structure to measure the variation of actuation strain in the piezoelectric actuator. During experiment, domain switching was observed at about 700V/mm and the DC supply voltage was raised to about 600V/mm. Experimental results and linear analysis expectancies for 4 specimens are reported in FIG. 7. While the experimental results are similar to the linear analysis expectancies in an earlier stage, there are large differences of about 40% between the experimental results and the linear analysis expectancies. The experimental results show large differences from the expectancies in higher electric fields because a. piezoelectric constant d33 provided from a product company is data measured in a relatively low voltage range and thus changes non-linearly by large values when the supply voltage approaches the domain switching voltage. FIG. 8 compares the modulus of strain of piezoelectric constant d31 with that of piezoelectric constant d33. It was observed that an actuation layer using piezoelectric constant d33 has an actuation strain performance at least 50% larger than that of another one using piezoelectric constant d3x . This means that the d33 actuation effect can be at least one half of the d31 actuation effect. The performance of the actuation layer was compared with the actuation strain performance of LaRC-MFC™, known as the most excellent one of ceramic actuation layers which have been developed up to the present, in order to more objectively compare the performance of the actuation layer of the invention. The result of comparison is reported in FIG. 9. The actuation strain of an IDEAL specimen of the invention was larger than that of LaRC-MFC™ for about 10% at electric fields up to 300V/mm and for about 25% at electric fields up to 600V/mm. This shows that the insertion IDE electrode structure has a d33 actuation effect superior to that of a surface IDE electrode structure. The foregoing description is only an embodiment of the piezoelectric actuator structure made of piezoelectric ceramics having a laminated ceramic layer and. a fabrication method according to the present invention. Accordingly, there is no intention to limit the present invention to such particularly illustrated and described embodiment. On the contrary, it is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention. The piezoelectric actuator made of piezoelectric ceramics having a laminated ceramic actuation layer according to the present invention proposes a policy of laminating and bonding unit panels one atop another to a designed thickness and slicing the panels into sheets to provide an IDEAL which adopts an insertion IDE electrode structure to maximize d33 actuation effect. As a result, this provides an effect of improving the performance of the piezoelectric actuator based upon experimental results that the piezoelectric actuator of the invention has actuation strain performance superior to that of AFC or LaRC-MFC which are evaluated as the most excellent laminated piezoelectric actuation layer. While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.

Claims

WHAT IS CLAIMED IS ;
1. A piezoelectric actuator structure made of piezoelectric ceramics having a laminated ceramic actuation layer comprising: a plurality of bar-shaped piezoelectric ceramics each having a first metal electrode coated on a top surface of a piezoelectric ceramic panel and a second metal electrode coated on a bottom surface of the piezoelectric ceramic panel, the first and second metal electrodes being coated to such extents that the top and bottom surfaces are partially exposed to form first and second etched portions, the second metal electrodes being located opposite in direction to the first metal electrodes, the piezoelectric ceramics being laminated one atop another to have alternating poling directions; and positive and negative sheet metal electrodes bonded to both ends of the laminated piezoelectric ceramics, wherein the piezoelectric ceramics are alternatively laminated so that the positive and negative sheet metal electrodes alternate with each other while being electrically and perpendicularly connected with terminal ends of the first and second metal electrodes.
2. The piezoelectric actuator structure according to claim 1, wherein the positive and negative sheet metal electrodes are bonded to terminal ends of the alternating metal electrodes via a conductive epoxy mixed with silver powder.
3. The piezoelectric actuator structure according to claim 1, wherein the positive and negative sheet metal electrodes are formed through plating.
4. A piezoelectric actuator structure made of piezoelectric ceramics having a laminated ceramic actuation layer comprising: a plurality of bar-shaped piezoelectric ceramics each having a metal electrode coated on a top surface of a piezoelectric ceramic panel, the metal electrode being coated to such an extent that the top surface is partially exposed to form an etched portions, the piezoelectric ceramics being laminated one atop another to have alternating poling directions; and positive and negative sheet metal electrodes bonded to both ends of the laminated piezoelectric ceramics, wherein the piezoelectric ceramics are alternatively laminated so that the positive and negative sheet metal electrodes alternate with each other while being electrically and perpendicularly connected with terminal ends of the first and second metal electrodes.
5. The piezoelectric actuator structure according to claim 4, wherein the positive and negative sheet metal electrodes are bonded to terminal ends of the alternating metal electrodes via a conductive epoxy mixed with silver powder.
6. The piezoelectric actuator structure according to claim 4, wherein the positive and negative sheet metal electrodes are formed through plating.
7. A fabrication method of a piezoelectric actuator made of piezoelectric ceramics, the method comprising the following steps of: (a) forming a plurality of first piezoelectric panels each having a first metal electrode coated on a top surface of a piezoelectric ceramic panel and a second metal electrode coated on a bottom surface of the piezoelectric ceramic panel, the first and second metal electrodes being coated to such extents that the top and bottom surfaces are partially exposed to form first and second etched portions, the second metal electrodes being located opposite in direction to the first metal electrodes; (b) alternating a plurality of second piezoelectric panels with the first piezoelectric panels, the second piezoelectric panels being configured symmetric with the first piezoelectric panels, and fixing the first and second piezoelectric panels with an epoxy adhesive to form a laminated piezoelectric ceramic structure of a predetermined size; (c) bonding positive and negative metal sheet electrodes to both lateral portions of the laminated piezoelectric ceramic structure having the etched portions via a conductive epoxy; and (d) after curing the conductive epoxy, cutting the laminated piezoelectric ceramic structure with the positive and negative metal sheet electrodes bonded thereto at a predetermined thickness.
8. The fabrication method according to claim 7, further comprising the step of polishing both lateral portions of the laminated piezoelectric ceramic structure after the step (b) .
9. The fabrication method according to claim 7, wherein the conductive epoxy is mixed with silver powder.
10. A fabrication method of a piezoelectric actuator made of piezoelectric ceramics, the method comprising the following steps of: (a) forming a plurality of first piezoelectric panels each having a first metal electrode coated on a top surface
• of a piezoelectric ceramic panel and a second metal electrode coated on a bottom surface of the piezoelectric ceramic panel, the first and second metal electrodes being coated to such extents that the top and bottom surfaces are partially exposed to form first and second etched portions, the second metal electrodes being located opposite in direction to the first metal electrodes; (b) alternating a plurality of second piezoelectric panels with the first piezoelectric panels, the second piezoelectric panels being configured symmetric with the first piezoelectric panels, and fixing the first and second piezoelectric panels with an epoxy adhesive to form a laminated piezoelectric ceramic structure of a predetermined size; (c) cutting the laminated piezoelectric ceramic structure into a laminated piezoelectric ceramic sheet at a predetermined thickness; and (d) bonding positive and negative metal sheet electrodes to both lateral portions of the laminated piezoelectric ceramic sheet having the etched portions via a conductive epoxy.
11. The fabrication method according to claim 10, further comprising the step of polishing both lateral portions of the laminated piezoelectric ceramic sheet after the step (b) .
12. The fabrication method according to claim 10, wherein the conductive epoxy is mixed with silver powder.
13. A fabrication method of a piezoelectric actuator made of piezoelectric ceramics, the method comprising the following steps of: (a) forming a plurality of first piezoelectric panels each having a first metal electrode coated on a top surface of a piezoelectric ceramic panel and a second metal electrode coated on a bottom surface of the piezoelectric ceramic panel, the first and second metal electrodes being coated to such extents that the top and bottom surfaces are partially exposed to form first and second etched portions; (b) plating both lateral portions of the first piezoelectric ceramic panels to form positive and negative metal sheet electrodes electrically connected with the first or second metal electrodes; (c) alternating a plurality of second piezoelectric panels with the first piezoelectric panels, the second piezoelectric panels being configured symmetric with the first piezoelectric panels, and fixing the first and second piezoelectric panels with an epoxy adhesive to form a laminated piezoelectric ceramic structure of a predetermined size; and (d) after curing the conductive epoxy, cutting the laminated piezoelectric ceramic structure with the positive and negative metal sheet electrodes bonded thereto at a predetermined thickness .
PCT/KR2004/000578 2004-01-08 2004-03-17 Piezoelectric actuator structure of piezoelectric ceramics having laminated ceramic actuating layer and fabrication method thereof WO2005067071A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008025315A1 (en) 2006-08-29 2008-03-06 Deutsches Zentrum für Luft- und Raumfahrt e.V. Piezoceramic surface actuator and method for the production thereof

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20230088187A (en) 2021-12-10 2023-06-19 엘티메탈 주식회사 Stacked piezoelectric element

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06283777A (en) * 1993-03-26 1994-10-07 Onoda Cement Co Ltd Multilayer piezoelectric actuater and manufacture thereof
JPH08126094A (en) * 1994-08-18 1996-05-17 Hewlett Packard Co <Hp> Compound type piezoelectric transducer array having improvedacoustic and electric impedance
EP1150363A2 (en) * 2000-04-20 2001-10-31 Tokin Ceramics Corporation Multilayer piezoelectric actuator device having a conductive member attached to an external electrode thereof
US6414418B1 (en) * 1999-03-04 2002-07-02 Robert Bosch Gmbh Piezoelectric actuator
JP2003510819A (en) * 1999-09-21 2003-03-18 ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツング How to attach a planar external electrode to a piezoceramic multilayer actuator

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06283777A (en) * 1993-03-26 1994-10-07 Onoda Cement Co Ltd Multilayer piezoelectric actuater and manufacture thereof
JPH08126094A (en) * 1994-08-18 1996-05-17 Hewlett Packard Co <Hp> Compound type piezoelectric transducer array having improvedacoustic and electric impedance
US6414418B1 (en) * 1999-03-04 2002-07-02 Robert Bosch Gmbh Piezoelectric actuator
JP2003510819A (en) * 1999-09-21 2003-03-18 ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツング How to attach a planar external electrode to a piezoceramic multilayer actuator
EP1150363A2 (en) * 2000-04-20 2001-10-31 Tokin Ceramics Corporation Multilayer piezoelectric actuator device having a conductive member attached to an external electrode thereof

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008025315A1 (en) 2006-08-29 2008-03-06 Deutsches Zentrum für Luft- und Raumfahrt e.V. Piezoceramic surface actuator and method for the production thereof
US20100295420A1 (en) * 2006-08-29 2010-11-25 Peter Wierach Piezoceramic surface actuator and method for the production thereof
DE102006040316B4 (en) * 2006-08-29 2012-07-05 Deutsches Zentrum für Luft- und Raumfahrt e.V. Piezoceramic Flächenaktuator and method for producing such
US8461745B2 (en) 2006-08-29 2013-06-11 Deutsches Zentrum für Luft- und Raumfahrt e.V. Piezoceramic surface actuator and method for the production thereof

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