| abstract |
Provided is: an elongated plate-form piezoelectric body, which contains an optically active helical chiral polymer (A) having a weight-average molecular weight of from 50,000 to 1,000,000 and has an elongated plate shape having a thickness of from 0.001 mm to 0.2 mm, a width of from 0.1 mm to 30 mm and a width-to-thickness ratio of 2 or higher, and in which the lengthwise direction and the main orientation direction of the helical chiral polymer (A) are substantially parallel to each other; the crystallinity measured by a DSC method is from 20% to 80%; and the birefringence is from 0.01 to 0.03. |