Patent ID: 11367827

Abstract:
A piezoelectric substrate, comprising: a conductor cord that has a core material and a conductor disposed around the core material; and an elongated piezoelectric body that is disposed around the conductor cord in a spiral manner, unidirectionally along an axial direction of the conductor cord, wherein: the piezoelectric body comprises an optically active helical chiral polymer, a lengthwise direction of the piezoelectric body and a main orientation direction of the helical chiral polymer in the piezoelectric body are substantially parallel to each other, the piezoelectric body has an orientation degree F. of from 0.5 to less than 1.0, and the conductor cord satisfies Formula (b): ΔDmax<tpmin, wherein ΔDmax is a maximum value of a difference in height between a division A that is selected from plural divisions and a division B that is adjacent to the division A, and tpmin is a minimum thickness of the piezoelectric body.