Electrode for piezoelectric composites

摘要

The invention provides an electrode for piezoelectric composites having high acoustic attenuation. The electrode is composed of a first layer having high elasticity and lower conductivity and of a second layer lying thereabove that has higher conductivity. The invention also provides a method for the manufacture thereof. The first layer is an intrinsically conductive plastic directly deposited on the ceramic whose polymerization is initiated by chemical or anodic oxidation of the corresponding monomers. The second layer is fashioned of adequately conductive metal and is preferably first sputtered on or vapor-deposited in a thinner layer and is then subsequently electrolytically reinforced. Piezoelectric composites that exhibit high acoustic attenation and, thus, prevent an acoustic crosstalk between the individual transducer elements can be manufactured from piezoelectric ceramic lamina or foils provided with such electrodes. Such composites also withstand higher mechanical distortion (for example, due to thermal expansion), even if the ceramic is highly porous.