1-1-3 Piezocomposite for hydrophone transducer

Abstract

A piezocomposite structure was prepared in a 1-1-3 configuration by casting a soft epoxy interlayer between PZT rods and a stiff polymer preform matrix to maximize the hydrostatic sensitivity of 1–3 type PZT polymer hydrophone transducers. By minimizing the adverse contribution of the lateral components of the hydrostatic pressure, a figure of merit of 7,200 (10⁻¹⁵ m²/N) was obtained in an ambient atmosphere. By encapsulating the composite with cover plates, a stable pressure dependence (up to 14 MPa) of the hydrostatic voltage and charge coefficients was obtained. In addition, the interface configuration between the composite and cover plate was modified to provide pressure amplification proportional to the reciprocal of the volume fraction of the PZT rods in the composite. As a result the modified interface structure in 1-1-3 composite transducer gave significantly increased piezoelectric coefficients, and the figure of merit at 2MPa hydrostatic pressure was enhanced to more than 22,000 (10⁻¹⁵ m²/N).