0–3 piezoelectric composites for large area hydrophones

Abstract

Piezoelectric ceramics exhibit relatively poor properties for use in large area hydrophones, in particular poor acoustic match to water, poor resistance to explosive shock, high densities and in the case of the PZT family of ceramics, poor hydrostatic voltage sensitivities. Dispersions of powders in polymers with 0–3 connectivity offer the possbility of fabricating large area transducers at low cost. The appropriate figures-of-merit to use in this application for optimising composite properties are discussed in the light of available amplifiers. Modified lead titanate 0–3 composites have been produced reproducibly with d_h.g_h of up to 1.8 × 10⁻−¹²Pa^1/2 (g_h = 82mVmN⁻¹). The effects of processing variables and other parameters on composite properties are discussed.

Key Words:

• piezoelectric
• composite
• lead titanate
• ceramic
• hydrophone