Piezoelectric array elements for sound reconstruction with a digital input

Patent metadata

Field	Value
Publication number	US-10327052-B2
Application number	US-201615563829-A
Country	US
Kind code	B2
Filing date	Apr 7, 2016
Priority date	Apr 8, 2015
Publication date	Jun 18, 2019
Grant date	Jun 18, 2019

Abstract

Various examples are provided for digital sound reconstruction using piezoelectric array elements. In one example, a digital loudspeaker includes a fixed frame and an array of transducers disposed on the fixed frame. Individual transducers of the array of transducers can include a flexible membrane disposed on a piezoelectric actuation element positioned over a corresponding opening that extends through the fixed frame. In another example, a method includes forming a flexible membrane structure on a substrate and backetching the substrate opposite the flexible membrane structure. The flexible membrane structure can be formed by disposing a first electrode layer on a substrate, disposing a piezoelectric layer on the first electrode layer and disposing a second electrode layer on the piezoelectric layer. A flexible membrane layer (e.g., polyimide) can be disposed on the second electrode layer.

First claim

Therefore, at least the following is claimed:

1. A digital loudspeaker, comprising:
a fixed frame having plural openings that extend through the fixed frame; and
an array of transducers disposed on the fixed frame,
wherein an individual transducer of the array of transducers includes a flexible membrane structure positioned over a corresponding opening in the fixed frame,
wherein the flexible membrane structure includes four layers,
a first electrode layer positioned directly over the opening,
a piezoelectric layer positioned over the first electrode layer,
a second electrode layer positioned over the piezoelectric layer so that the piezoelectric layer is sandwiched between the first and second electrode layers, and
a flexible membrane layer positioned over the second electrode layer.

2. The digital loudspeaker of claim 1 , wherein the first and second electrodes layers are in contact with the piezoelectric layer.

3. The digital loudspeaker of claim 1 , wherein the first and second electrodes layers comprises parallel electrodes disposed on opposite sides of the piezoelectric layer.

4. The digital loudspeaker of claim 1 , wherein the first and second electrodes layers comprises interdigitated electrodes disposed on the piezoelectric layer.

5. The digital loudspeaker of claim 1 , wherein the piezoelectric layer includes lead-zirconate-titanate (PZT).

6. The digital loudspeaker of claim 1 , wherein the first and second electrodes layers comprise platinum.

7. The digital loudspeaker of claim 1 , wherein a polarization of the piezoelectric layer via the first and second electrodes layers distorts the flexible membrane with respect to the fixed frame.

8. The digital loudspeaker of claim 1 , wherein the flexible membrane is formed of polyimide.

9. The digital loudspeaker of claim 1 , wherein the array of transducers is configured to provide at least 3-bit resolution of an audio signal.

10. The digital loudspeaker of claim 9 , wherein 3-bit resolution is provided by seven transducers.

11. The digital loudspeaker of claim 1 , wherein a diameter of an outer edge of the piezoelectric actuation element is less than a diameter of an inner surface of the corresponding opening.

12. The digital loudspeaker of claim 11 , wherein the piezoelectric actuation element comprises a plurality of connection lines extending outward from the outer edge.

13. The digital loudspeaker of claim 12 , wherein the plurality of connection lines extend radially outward beyond the diameter of the inner surface of the corresponding opening.

14. The digital loudspeaker of claim 1 , wherein the fixed frame is a plate of a buckled cantilever platform.

15. The digital loudspeaker of claim 14 , wherein the buckled cantilever platform comprises bimorph actuators configured to adjust position of the plate in response to thermal heating.

16. A digital loudspeaker, comprising:
a fixed frame having plural holes; and
plural transducers disposed on the fixed frame, wherein each individual transducer of the array of transducers is located over a corresponding hole of the plural holes,
wherein each individual transducer comprises a piezoelectric actuation element, and each piezoelectric actuation element includes four layers,
a first electrode layer positioned directly over the opening,
a piezoelectric layer positioned over the first electrode layer,
a second electrode layer positioned over the piezoelectric layer so that the piezoelectric layer is sandwiched between the first and second electrode layers, and
a flexible membrane layer positioned over the second electrode layer.

Assignees

• Univ King Abdullah Sci & Tech

Inventors

• Arevalo Carreno Armando Arpys
• CONCHOUSO GONZALEZ David
• CASTRO SIGNORET David
• Foulds Ian G

Classifications

• H04R31/00

  Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor {(manufacture of microstructural arrangements of deformable or non-deformable structures in general B81C1/00182)} · CPC title

• H04R17/00

  Piezoelectric transducers; Electrostrictive transducers (piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners {H10N30/00}) · CPC title

• H04R17/005

  using a piezoelectric polymer · CPC title

• H04R1/02

  Casings; Cabinets {; Supports therefor;} Mountings therein (H04R1/28 takes precedence {; attachments for microphones H04R1/08; mounting of transducers in earpieces H04R1/1075}) · CPC title

• H04R1/005 Primary

  using digitally weighted transducing elements · CPC title