US 11,925,121 B2
Piezoelectric element having excellent flexibility and bend resistance
Ken Ogasahara, Nara (JP); Satoshi Shimizu, Nara (JP); Susumu Kawato, Nara (JP); and Kousuke Nishikawa, Nara (JP)
Assigned to TOHO KASEI CO., LTD., Nara (JP)
Appl. No. 17/272,737
Filed by TOHO KASEI CO., LTD., Nara (JP)
PCT Filed Aug. 1, 2019, PCT No. PCT/JP2019/030242
§ 371(c)(1), (2) Date Mar. 2, 2021,
PCT Pub. No. WO2020/049912, PCT Pub. Date Mar. 12, 2020.
Claims priority of application No. 2018-167231 (JP), filed on Sep. 6, 2018.
Prior Publication US 2021/0351337 A1, Nov. 11, 2021
Int. Cl. H10N 30/60 (2023.01); H10N 30/857 (2023.01); H10N 30/88 (2023.01)
CPC H10N 30/60 (2023.02) [H10N 30/857 (2023.02); H10N 30/883 (2023.02)] 9 Claims
OG exemplary drawing
 
1. A piezoelectric element comprising
a core wire which is formed by winding at least one layer of metal foil helically around a resin wire,
an organic piezoelectric layer which coats the core wire, and
a conductor layer which coats the organic piezoelectric layer,
wherein the metal foil and the conductor layer each function as an electrode having the organic piezoelectric layer interposed therebetween, the at least one layer of metal foil is helically wound around the resin wire with gaps, and the ratio of the gap to the helical pitch of the metal foil is 0.4% to 50%.