US4688306A
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US
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Method of preparing a piezoelectric device
Assignee: Focas Ltd
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Filing: 1986-09-11
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Granted: 1987-08-25
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Expires: 2006-09-11
Abstract
Abstract A piezoelectric device comprising a first conductor, a conductive polymer member which contacts the first conductor, a piezoelectric polymer member which contacts the conductive polymer member but which is separated from the first conductor and which has been rendered piezoelectric by stretching and polarizing it while it is in contact with the conductive polymer member, and a second conductor which contacts the piezoelectric polymer member but which is separated from both the conductive polymer and the first conductor.
Inventors
- 👤 Pravin L. Soni
- 👤 Nigel R. Farrar
- 👤 Peter Turk
- 👤 Christiaan J. Rauwendaal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:30
CPC Classifications
H; H10; H10N; H10N30/00; H10N30/60; H10N30/01; H10N30/04; H10N30/045; H10N30/09; H10N30/098; Y; Y10; Y10S; Y10S310/00; Y10S310/80; Y10T; Y10T29/00; Y10T29/42; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
158 words
A method of preparing a piezoelectric device comprising (a) providing a metallic first conductor having a melting point in the range between about 50° C. and about 170° C. (b) applying a conductive polymer member to the first conductor such that the first conductor and the conductive polymer member are in contact, (c) applying a dielectric polymer member which is capable of being rendered piezoelectric to the conductive polymer member such that the conductive polymer member and the dielectric polymer member are in contact, (d) heating the first conductor, the conductive polymer member, and the dielectric polymer member to a temperature above the melting point of the first conductor, whereby the first conductor becomes molten, (e) stretching the dielectric polymer member while the first conductor is molten, (f) polarizing the dielectric polymer member while it contacts the conductive polymer member to render the dielectric polymer member piezoelectric, and (g) applying an outer conductor to the dielectric polymer member.
Claim 2
Independent Claim
158 words
A method of preparing a piezoelectric device comprising (a) providing a metallic first conductor having a melting point in the range between about 50° C. and about 170° C. (b) applying a conductive polymer member to the first conductor such that the first conductor and the conductive polymer member are in contact, (c) applying a dielectric polymer member which is capable of being rendered piezoelectric to the conductive polymer member such that the conductive polymer member and the dielectric polymer member are in contact, (d) heating the first conductor, the conductive polymer member, and the dielectric polymer member to a temperature above the melting point of the first conductor, whereby the first conductor becomes molten, (e) stretching the dielectric polymer member while the first conductor is molten, (f) polarizing the dielectric polymer member while it contacts the conductive polymer member to render the dielectric polymer member piezoelectric, and (g) applying an outer conductor to the dielectric polymer member.
Claim 3
Dependent Claim
19 words
A method according to claim 1 wherein the first conductor comprises a metal melting at or below 150° C.
Claim 4
Dependent Claim
19 words
A method according to claim 1 wherein the first conductor is molten when the conductive polymer member is applied.
Claim 5
Dependent Claim
15 words
A method according to claim 1 wherein the dielectric polymer member is applied by extrusion.
Claim 6
Dependent Claim
20 words
A method according to claim 1 wherein the conductive polymer and the dielectric polymer members are simultaneously applied by coextrusion.
Claim 7
Dependent Claim
18 words
A method according to claim 1 wherein the conductive polymer member has a resistivity below about 500 ohm-cm.
Claim 8
Dependent Claim
15 words
A method according to claim 1 wherein the conductive polymer member comprises an acrylic elastomer.
Claim 9
Dependent Claim
15 words
A method according to claim 1 wherein the conductive polymer member comprises a fluorinated elastomer.
Claim 10
Dependent Claim
16 words
A method according to claim 1 wherein the piezoelectric polymer member comprises a vinylidene fluoride polymer.
Claim 11
Dependent Claim
15 words
A method according to claim 1 wherein the piezoelectric polymer member comprises vinylidene fluoride homopolymer.
Claim 12
Dependent Claim
18 words
A method according to claim 1 wherein the dielectric polymer member is stretched by 200 to 400 percent.
Claim 13
Dependent Claim
25 words
A method according to claim 1 wherein the dielectric polymer member is polarized in an electric field in the range of 50 to 150 MV/m.
Claim 14
Dependent Claim
13 words
A method according to claim 1 wherein the second conductor comprises a metal.
Claim 15
Dependent Claim
17 words
A method according to claim 1 further comprising applying an electrically insulating jacket to the second conductor.
Claim 16
Independent Claim
123 words
A method of preparing a coaxial cable comprising (a) providing a metallic inner conductor having a melting point in the range between about 50° C. and about 170° C., (b) extruding a conductive polymer member over the inner conductor, (c) extruding a dielectric polymer member which is capable of being rendered piezoelectric over the conductive polymer member, (d) heating the inner conductor, the conductive polymer member, and the dielectric polymer member to a temperature above the melting point of the inner conductor, whereby the inner conductor becomes molten, (e) stretching the dielectric polymer member while the first conductor is molten, (f) polarizing the dielectric polymer member to render said member piezoelectric, and (g) applying a second metallic conductor to the dielectric polymer member.
Claim 17
Independent Claim
123 words
A method of preparing a coaxial cable comprising (a) providing a metallic inner conductor having a melting point in the range between about 50° C. and about 170° C., (b) extruding a conductive polymer member over the inner conductor, (c) extruding a dielectric polymer member which is capable of being rendered piezoelectric over the conductive polymer member, (d) heating the inner conductor, the conductive polymer member, and the dielectric polymer member to a temperature above the melting point of the inner conductor, whereby the inner conductor becomes molten, (e) stretching the dielectric polymer member while the first conductor is molten, (f) polarizing the dielectric polymer member to render said member piezoelectric, and (g) applying a second metallic conductor to the dielectric polymer member.
Claim 18
Dependent Claim
20 words
A method according to claim 15 wherein the metallic inner conductor comprises a metal melting at or below 150° C.
Claim 19
Dependent Claim
18 words
A method accoring to claim 15 wherein the conductive polymer member and the dielectric polymer member are coextruded.
Claim 20
Dependent Claim
15 words
A method according to claim 15 wherein the conductive polymer member comprises an acrylic elastomer.
Claim 21
Dependent Claim
15 words
A method according to claim 15 wherein the conductive polymer member comprises a fluorinated elastomer.
Claim 22
Dependent Claim
16 words
A method according to claim 15 wherein the piezoelectric polymer member comprises a vinylidene fluoride polymer.
Claim 23
Dependent Claim
15 words
A method according to claim 15 wherein the piezoelectroc polymer member comprises vinylidene fluoride homopolymer.
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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) | 1990-08-24 | 1991-02-23 | 1991-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-24 | 1995-02-23 | 1995-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-24 | 1999-02-23 | 1999-08-25 | $7700.00 | Window Closed / Lapsed |