Piezoelectric/electrostrictive device and method of manufacturing same

• US 20070035209A1
• Filed: 10/20/2006
• Published: 02/15/2007
• Est. Priority Date: 10/01/1999
• Status: Active Grant

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Takeuchi, Yukihisa, Namerikawa, Masahiko, Shibata, Kazuyoshi
• Granted Patent: US 7,336,021 B2
• Time in Patent Office: Days
• US Class Current: 310/328
• CPC Class Codes: H10N 30/05 Manufacture of multilayered piezoelectric or electrostrictive devices, or parts thereof, e.g. by stacking piezoelectric bodies and electrodes
• CPC Class Codes: H10N 30/2042 Cantilevers, i.e. having one fixed end
• CPC Class Codes: H10N 30/2043 connected at their free ends, e.g. parallelogram type
• CPC Class Codes: H10N 30/2044 having multiple segments mechanically connected in series, e.g. zig-zag type
• CPC Class Codes: H10N 30/501 with non-rectangular cross-section in stacking direction, e.g. polygonal, trapezoidal

Abstract

A piezoelectric/electrostrictive (P/E) device includes at least one actuator section secured to thin plate sections with an adhesive. The actuator section includes a multilayered member including at least three actuator films, each of which include a P/E layer and electrode films. One or more holes or recesses are formed in portions of the thin plate sections on which the P/E elements are formed. The electrode films contact upper and lower surfaces of respective P/E layers and alternately extend to opposite surfaces thereof. End surface electrodes electrically connect an electrode film that contacts one of the P/E layers and an electrode film that contacts another one of the P/E layers. The end surface electrodes are electrically connected to terminals which are provided on a surface of an outermost layer of the P/E layers, and which are separated from one another by a predetermined distance.

Claims

1. A piezoelectric/electrostrictive device comprising:

a pair of mutually opposing thin plate sections, said thin plate sections each having a width “

b” and

being spaced apart by a distance “

a”

, such that a ratio a/b is 0.5 to 20;

a fixation section for supporting said thin plate sections;

a movable section disposed at an opposite end of said thin plate sections from said fixation section; and

at least one stacked type piezoelectric/electrostrictive element comprising a plurality of piezoelectric/electrostrictive layers and electrode films disposed on at least one of said thin plate sections.

2. A piezoelectric/electrostrictive device comprising:

a pair of mutually opposing thin plate sections;

a fixation section for supporting said thin plate sections;

a movable section disposed at an opposite end of said thin plate sections from said fixation section and spaced a distance La from said fixation section;

an actuator section with at least one stacked type piezoelectric/electrostrictive element fixed on at least one of said thin plate sections, said at least one stacked type piezoelectric/electrostrictive element comprising a plurality of piezoelectric/electrostrictive layers and electrode films, said electrode films contacting upper and lower surfaces of respective piezoelectric/electrostrictive layers and alternately extending to opposite end surfaces thereof such that a first end of each said electrode film is positioned at one of said opposite end surfaces and a second end of said electrode film extends a distance short of another of said opposite end surfaces, whereby said second end of one of said electrode films located nearest said movable section is spaced a distance Lb from said movable section; and

end surface electrodes electrically connecting a first end of an electrode film that contacts one of said piezoelectric/electrostrictive layers and a first end of an electrode film that contacts another one of said piezoelectric/electrostrictive layers, said end surface electrodes being formed on respective outer side surfaces of said actuator section,

wherein said at least one stacked type piezoelectric/electrostrictive element is disposed partially on said thin plate section and said fixation section, or partially on said thin plate section and said movable section, and

wherein (1-Lb/La) is not less than 0.4.