FLEXIBLE PIEZOELECTRIC STRUCTURES AND METHOD OF MAKING SAME

• US 20120312456A1
• Filed: 08/03/2012
• Published: 12/13/2012
• Est. Priority Date: 11/06/2009
• Status: Active Grant

• Current Assignee: The Trustees of Princeton University (Princeton University)
• Original Assignee: The Trustees of Princeton University (Princeton University)
• Inventors: McAlpine, Michael C., Qi, Yi
• Granted Patent: US 9,502,638 B2
• Time in Patent Office: Days
• US Class Current: 156/151
• CPC Class Codes: A61B 5/25 Bioelectric electrodes therefor
• CPC Class Codes: A61K 51/1282 Devices used in vivo and carrying the radioactive therapeutic or diagnostic agent, therapeutic or in vivo diagnostic kits, stents
• CPC Class Codes: A61L 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence
• CPC Class Codes: H01L 21/76251 using bonding techniques
• CPC Class Codes: H01L 21/76259 with separation/delamination along a porous layer
• CPC Class Codes: H10N 30/074 by depositing piezoelectric or electrostrictive layers, e.g. aerosol or screen printing
• CPC Class Codes: H10N 30/1051 based on piezoelectric or electrostrictive films or coatings
• CPC Class Codes: H10N 30/206 using only longitudinal or thickness displacement, e.g. d33 or d31 type devices
• CPC Class Codes: H10N 30/883 Further insulation means against electrical, physical or chemical damage, e.g. protective coatings
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49124 On flat or curved insulated base, e.g., printed circuit, etc.

Abstract

A flexible piezoelectric structure and a method of making the structure are disclosed. A piezoelectric film having a relatively high piezoelectric coefficient is attached to a flexible substrate. The piezoelectric film is fabricated on a different substrate and transferred to the flexible substrate by contact.

Claims

1. A method for fabricating a biocompatible flexible piezoelectric structure, comprising:

depositing a first piezoelectric film by film deposition on a first substrate;

contacting a biocompatible flexible substrate with the first piezoelectric film; and

separating the first piezoelectric film and biocompatible flexible substrate from the first substrate, the first piezoelectric film remaining attached to the biocompatible flexible substrate.

2. The method of claim 1, further comprising patterning the first piezoelectric film.

3. The method of claim 2, wherein the patterning comprises patterning the first piezoelectric film into ribbons having a non-circular cross-section.

4. The method of claim 1, wherein depositing comprises at least one of sputtering, radio-frequency sputtering, hydrothermal deposition, chemical vapor deposition (CVD), metal-organic CVD, sol-gel deposition, laser ablation, pulsed laser deposition, or molecular beam epitaxy.

5. The method of claim 1, wherein the first piezoelectric film comprises an inorganic material.

6. The method of claim 1, wherein the first piezoelectric film comprises at least one of a non-polymeric material, a non-crystalline material, a partially crystalline material, a polycrystalline material, or a crystalline material.

7. The method of claim 1, wherein the first piezoelectric film comprises a material having a piezoelectric coefficient exceeding 26 picoCoulombs/Newton.

8. The method of claim 1, wherein the first piezoelectric film comprises at least one of:

PZT, ZnO, Quartz, LiNbO₃, SrTiO₃, BaTiO₃, lead zirconate, or lead titanate.

9. The method of claim 1, further comprising encapsulating the first piezoelectric film with a second flexible substrate.

10. The method of claim 1, further comprising fabricating first and second electrodes in contact with the first piezoelectric film.

11. The method of claim 1, wherein the first and second electrodes are both fabricated in contact with one side of the first piezoelectric film.

12. The method of claim 1, wherein the first and second electrodes are respectively fabricated in contact with opposite sides of the first piezoelectric film.

13. The method of claim 3, further comprising fabricating electrode fingers running parallel to the ribbons.

14. The method of claim 3, further comprising fabricating electrode fingers running perpendicular to the ribbons.

15. The method of claim 1, wherein the flexible substrate comprises at least one of:

polydimethylsiloxane (PDMS), polyethylene terephthalate (PET), polyether ether ketone (PEEK), a polyimide, or a polyester.

16. The method of claim 1, further comprising repeating the depositing, contacting and separating to dispose at least one additional piezoelectric film stacked over the first piezoelectric film.