US 12,426,510 B2
Piezoelectric element
Takayuki Yonemura, Suwa (JP); and Jiro Kato, Suwa (JP)
Assigned to SEIKO EPSON CORPORATION, (JP)
Filed by Seiko Epson Corporation, Tokyo (JP)
Filed on Jan. 28, 2022, as Appl. No. 17/586,951.
Claims priority of application No. 2021-013649 (JP), filed on Jan. 29, 2021.
Prior Publication US 2022/0246826 A1, Aug. 4, 2022
Int. Cl. H10N 30/00 (2023.01); H10N 30/857 (2023.01)
CPC H10N 30/702 (2024.05) [H10N 30/857 (2023.02)] 7 Claims
OG exemplary drawing
 
1. A piezoelectric element, comprising:
a piezoelectric layer including a first plane and a second plane having a front and back relationship with each other, the piezoelectric layer containing a helical chiral polymer exhibiting piezoelectric properties;
a first electrode layer provided on the first plane of the piezoelectric layer;
a second electrode layer provided on the second plane of the piezoelectric layer;
a first coupling portion provided on the first electrode layer, and
a second coupling portion provided on the second electrode layer, wherein
an overlapped portion where the piezoelectric layer, the first electrode layer, and the second electrode layer overlap is circular shaped when viewed along a thickness direction of the piezoelectric layer, and
the first coupling portion and the second coupling portion overlap with a center of the overlapped portion when viewed along the thickness direction of the piezoelectric layer, and
the helical chiral polymer has a molecular structure that is a helical structure, and provided that an axis of the helical structure is a c-axis, the helical chiral polymer is a crystal in which the c-axis is uniaxially oriented in a plane of the piezoelectric laver.