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Patent US4944891A successfully refreshed from Google Patents.
US4944891A
Expired / Lapsed
US
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Easily poled 0-3 piezoelectric composites for transducer applications
Assignee: CNA Holdings LLC
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Filing: 1987-03-06
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Granted: 1990-07-31
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Expires: 2007-03-06
Abstract
Abstract A PZT-polymer composite of 0-3 connectivity further includes a third phase particulate additive of conductive or semiconductive material to increase the electrical conductivity of the polymer matrix.
Inventors
- 👤 Geon Sagong
- 👤 Robert E. Newnham
- 👤 Ahmad Safari
- 👤 Sei-Joo Jang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:23
CPC Classifications
H; H10; H10N; H10N30/00; H10N30/80; H10N30/85; H10N30/852
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
80 words
A poled piezoelectric-polymer composite material of 0-3 connectivity for use in transducer applications and which comprises: a matrix of insulating polymer, a piezoelectric ceramic powder dispersed within said polymer matrix and an inorganic conductive or semiconductive particulate third phase additive dispersed within said polymer matrix, said inorganic third phase additive having an electrical conductivity greater than the electrical conductivity of said insulating polymer matrix, said composite being poled in a poling field strength of at least 20 kilovolts per centimeter.
Claim 2
Dependent Claim
80 words
A poled piezoelectric-polymer composite material of 0-3 connectivity for use in transducer applications and which comprises: a matrix of insulating polymer, a piezoelectric ceramic powder dispersed within said polymer matrix and an inorganic conductive or semiconductive particulate third phase additive dispersed within said polymer matrix, said inorganic third phase additive having an electrical conductivity greater than the electrical conductivity of said insulating polymer matrix, said composite being poled in a poling field strength of at least 20 kilovolts per centimeter.
Claim 3
Dependent Claim
28 words
The poled piezoelectric-polymer composite of claim 1 wherein said third phase particulate additive has an electrical conductivity of at least about 10 -3 ohm -1 cm -1 .
Claim 4
Dependent Claim
24 words
The poled piezoelectric-polymer composite of claim 1 wherein said third phase particulate additive comprises about 1.5 to about 4 vol. % of said composite.
Claim 5
Dependent Claim
14 words
The poled piezoelectric-polymer composite of claim 1 wherein said third phase additive is inorganic.
Claim 6
Dependent Claim
17 words
The poled piezoelectric-polymer composite of claim 4 wherein said third phase particulate additive is a conductive metal.
Claim 7
Dependent Claim
17 words
The poled piezoelectric-polymer composite of claim 4 wherein said third phase particulate additive is a semiconductive material.
Claim 8
Dependent Claim
12 words
The piezoelectric-polymer composite of claim 6 wherein said semiconductive material is carbon.
Claim 9
Dependent Claim
12 words
The piezoelectric-polymer composite of claim 6 wherein said semiconductive material is germanium.
Claim 10
Dependent Claim
12 words
The piezoelectric-polymer composite of claim 6 wherein said semiconductive material is silicon.
Claim 11
Dependent Claim
25 words
The piezoelectric-polymer composite of claim 1 wherein said piezoelectric ceramic powder comprises at least about 60 vol. % of said ceramic powder and polymer mixture.
Claim 12
Dependent Claim
15 words
The piezoelectric polymer composite of claim 10 wherein said insulating polymer is an epoxy resin.
Claim 13
Dependent Claim
15 words
The piezoelectric-polymer composite of claim 1 wherein said piezoelectric ceramic powder is lead zirconate titanate.
Claim 14
Dependent Claim
21 words
The poled piezoelectric-polymer composite of claim 1 wherein said poling field was applied for at least 3 minutes on said composite.
Claim 15
Dependent Claim
17 words
The pieozelectric-polymer composite of claim 1 wherein said poling field was applied for at least 5 minutes.
Claim 16
Dependent Claim
18 words
The piezoelectric-polymer composite of claim 1 wherein said poling field strength was at least 30 kilovolts per centimeter.
Claim 17
Dependent Claim
19 words
The piezoelectric-polymer composite of claim 1 wherein said poling field strength was at least about 35 kilovolts per centimeter.
Claim 18
Dependent Claim
17 words
The piezoelectric-polymer composite of claim 16 wherein said poling field was applied for at least 5 minutes.
References Cited (Backward Citations)
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Cited
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Cited
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Cited
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-30 | 1994-01-29 | 1994-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-30 | 1998-01-29 | 1998-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-30 | 2002-01-29 | 2002-07-31 | $7700.00 | Window Closed / Lapsed |