Composite bond for acoustic transducers

Claim 1

An acoustic device comprising: a piezoelectric transducer having a first and a second surface and a first acoustic impedance, an acoustic medium having a third surface and a second acoustic impedance different from the first acoustic impedance, first electrode means attached to the first surface, a sheetlike electrically conductive metal mesh positioned between the second and third surfaces and forming a second electrode means, the electrically conductive metal mesh having a plurality of openings therein, and, a polymerizable plastic material filling the openings of the electrically conductive metal mesh and adhering to the second and third surfaces, the electrically conductive metal mesh and the polymerizable plastic material forming a composite bond having a third acoustic impedance essentially equal to the square root of the first And second acoustic impedances, the third acoustic impedance being determined by the impedance of the electrically conductive metal mesh, the impedance of the polymerizable plastic material, and the percentage of open space in the electrically conductive metal mesh.