PIEZOELECTRIC ELEMENT

• US 20150280102A1
• Filed: 10/10/2013
• Published: 10/01/2015
• Est. Priority Date: 10/12/2012
• Status: Abandoned Application

• Current Assignee: Kansai University, Teijin Limited
• Original Assignee: Kansai University, Teijin Limited
• Inventors: Tajitsu, Yoshiro, Uchiyama, Akihiko, Ono, Yuhei, Yamamoto, Tomoyoshi
• Application Number:
  US14/434,874
• Publication Number:
  US 20150280102A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01L 1/16 using properties of piezoelectric devices
• CPC Class Codes: G06F 3/0414 using force sensing means to determine a position
• CPC Class Codes: H02N 2/18 producing electrical output from mechanical input, e.g. generators for measurement devices G01
• CPC Class Codes: H10N 30/06 Forming electrodes or interconnections, e.g. leads or terminals
• CPC Class Codes: H10N 30/098 Forming organic materials
• CPC Class Codes: H10N 30/206 using only longitudinal or thickness displacement, e.g. d33 or d31 type devices
• CPC Class Codes: H10N 30/302 Sensors
• CPC Class Codes: H10N 30/60 having a coaxial cable structure
• CPC Class Codes: H10N 30/702 based on piezoelectric or electrostrictive fibres
• CPC Class Codes: H10N 30/857 Macromolecular compositions

Abstract

A fibrous or cloth piezoelectric element capable of extracting an electric output with relatively small stress produced by rubbing the surface with a finger. The piezoelectric element includes a piezoelectric unit including two conductive fibers and one piezoelectric fiber, all of which are arranged substantially on the same plane while they have contact points between them.

Claims

1. A piezoelectric element comprising a piezoelectric unit including two conductive fibers and one piezoelectric fiber all of which are arranged substantially on the same plane while they have contact points between them.

2. The piezoelectric element according to claim 1, wherein the piezoelectric unit includes a conductive fiber, a piezoelectric fiber and a conductive fiber all of which are arranged in this order.

3. The piezoelectric element according to claim 2, wherein the piezoelectric unit includes a conductive fiber, a piezoelectric fiber and a conductive fiber all of which are arranged substantially parallel to one another.

4. The piezoelectric element according to claim 1, wherein the piezoelectric unit includes an insulating fiber which is arranged such that the conductive fibers in the piezoelectric unit are not in contact with conductive fibers and a piezoelectric fiber in another piezoelectric unit.

5. The piezoelectric element according to claim 1, wherein the piezoelectric fiber comprises polylactic acid as the main component.

6. The piezoelectric element according to claim 1, wherein the piezoelectric fiber comprises poly-L-lactic acid or poly-D-lactic acid as the main component and the optical purities of these components are 99% or more.

7. The piezoelectric element according to claim 1, wherein the piezoelectric fiber is uniaxially oriented and contains a crystal.

8. The piezoelectric element according to claim 1, wherein the conductive fiber is a carbon fiber.

9. The piezoelectric element according to claim 4, wherein the insulating fiber comprises a polyethylene terephthalate-based fiber as the main component.

10. The piezoelectric element according to claim 3 which is a woven or knitted fabric comprising a plurality of parallel piezoelectric units.

11. The piezoelectric element according to claim 10 which is a woven fabric comprising a plurality of parallel piezoelectric units and having a satin weave structure.

12. The piezoelectric element according to claim 11, wherein the piezoelectric units are arranged in the weft direction.

13. The piezoelectric element according to claim 11, wherein the step number of a piezoelectric fiber in the piezoelectric unit is 3 to 7.

16. The piezoelectric element according to claim 1 which is a sensor for detecting the size of stress applied to the piezoelectric element and/or the application position.

17. The piezoelectric element according to claim 16, wherein stress applied to the piezoelectric element to be detected is rubbing force to the surface of the piezoelectric element.

18. The piezoelectric element according to claim 1 which is an actuator that changes its shape according to an electric signal applied to the piezoelectric element.

14. A piezoelectric element which includes a conductive fiber, a piezoelectric polymer covering the surface of the fiber, and a surface conductive layer formed on the surface of the piezoelectric polymer.

15. A piezoelectric element including at least two covered fibers obtained by covering the surfaces of conductive fibers with a piezoelectric polymer, wherein the covered fibers are arranged substantially parallel to each other and the piezoelectric polymers on the surfaces are in contact with each other.