Thermally stable, piezoelectric and pyroelectric polymeric substrates and method relating thereto

• US 6,379,809 B1
• Filed: 08/18/1998
• Issued: 04/30/2002
• Est. Priority Date: 09/07/1995
• Status: Expired due to Fees

• Current Assignee: United States Incorporated, United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: St. Clair, Terry L., Simpson, Joycelyn O.
• Primary Examiner(s): Thibodeau, Paul
• Assistant Examiner(s): TARAZANO, DONALD LAWRENCE
• Application Number:
  US09/135,888
• Time in Patent Office: 1,351 Days
• Field of Search: 428/458, 428/457, 428/413, 428/412, 428/416, 428/473.5, 428/461, 310/311, 310/800, 310/313.A
• US Class Current: 428/458
• CPC Class Codes: H10N 15/15 Selection of materials
• CPC Class Codes: H10N 30/045 by polarising
• CPC Class Codes: H10N 30/098 Forming organic materials
• CPC Class Codes: H10N 30/857 Macromolecular compositions
• CPC Class Codes: Y10S 310/80 Piezoelectric polymers, e.g. PVDF
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 428/31507 Of polycarbonate
• CPC Class Codes: Y10T 428/31511 Of epoxy ether
• CPC Class Codes: Y10T 428/31522 Next to metal
• CPC Class Codes: Y10T 428/31681 Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]
• CPC Class Codes: Y10T 428/31692 Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31721 Of polyimide

Abstract

A thermally stable, piezoelectric and pyroelectric polymeric substrate was prepared. This thermally stable, piezoelectric and pyroelectric polymeric substrate may be used to prepare electromechanical transducers, thermomechanical transducers, accelerometers, acoustic sensors, infrared sensors, pressure sensors, vibration sensors, impact sensors, in-situ temperature sensors, in-situ stress/strain sensors, micro actuators, switches, adjustable fresnel lenses, speakers, tactile sensors, weather sensors, micro positioners, ultrasonic devices, power generators, tunable reflectors, microphones, and hydrophones. The process for preparing these polymeric substrates includes: providing a polymeric substrate having a softening temperature greater than 100° C.; depositing a metal electrode material onto the polymer film; attaching a plurality of electrical leads to the metal electrode coated polymeric substrate; heating the metal electrode coated polymeric substrate in a low dielectric medium; applying a voltage to the heated metal electrode coated polymeric substrate to induce polarization; and cooling the polarized metal electrode coated polymeric electrode while maintaining a constant voltage.

Claims

1. A thermally stable, oriented, piezoelectric and pyroelectric polymeric substrate comprising:

(a) a polymeric member having a softening temperature greater than about 100°

C. wherein said member is an anisotropic polymer containing polarizable moieties; and

(b) a metal electrode material deposited onto the polymeric member to form a metal electrode coated polymeric substrate

wherein a polar field is applied to the metal electrode coated polymeric substrate;

wherein said substrate remains stable at temperatures above about 100°

C. up to about the softening temperature of the polymeric member;

wherein said polymeric member comprises a polymer selected from the group consisting of;

a polyarylate;

a polyphenylene ether;

a polycarbonate;

a polyphenylene sulfide;

a polysulfone;

a polyaryletherketone;

a polyimide;

a polyazomethine;

a polyquinoxaline;

a polybenzimidazole; and

a polyarylene ether;

further wherein said polymeric member comprises the repeat unit;

 

wherein R is selected from the group consisting of;

Ar′

is selected from the group consisting of;

any aromatic moiety and any aromatic moiety having a polarizable group;

Ar is;

 

wherein the catenation is ortho, para, or meta;

Z is a hydrogen or Q—

Y;

Q is a direct bond or any aromatic moiety;

Y is selected from the group consisting of;

—

CF₃, —

CN, —

NO₂, and —

SF₅;

X is selected from the group consisting of —

O—

, —

CO—

, —

SO₂—

, and —

CH₂—

; and

n is an integer ranging from about 1 to about 10.

2. A thermally stable, piezoelectric and pyroelectric polymeric substrate according to claim 1, wherein:

Ar′

is selected from the group consisting of;

Y is selected from the group consisting of;

—

CF₃, —

CN, —

NO₂, and —

SF₅; and

X is selected from the group consisting of;

—

O—

, —

CO—

, —

SO₂—

, and —

CH₂—

.

3. A thermally stable, pielectric and pyroelectric polymeric substrate according to claim 2, wherein R is:

4. An article prepared from the thermally stable, piezoelectric and pyroelectric polymeric substrate according to claim 3, wherein the article is selected from the group consisting of:

an electromechanical transducer, a thermomechancial transducer, an accelerometer, an acoustic sensor, an infrared sensor, a pressure sensor, a vibration sensor, an impact sensor, an in-situ temperature sensor, an in-situ stress/strain sensor, a micro actuator, a switch, an adjustable fresnel lense, a speaker, a tunable reflector, a microphone, a tactile sensor, a weather sensor, a micropositioner, an ultrasonic device, a power generator and a hydrophone.