Patent ID: 6262517
Filing Date: 2001-07-17
Classification: G01H

Abstract:
A piezoelectric acoustic sensor comprising:an array of parallel rod-like or blade-shaped elements formed from a dense, poled, strongly piezoelectric or electrostrictive ceramic material;a polymeric matrix encapsulating said array to form a two-phase ceramic/polymer composite body exhibiting 1-3 or 2-2 connectivity and having upper and lower planar surfaces and at least four edge surfaces, upper and lower ends of said elements being exposed at said planar surfaces;upper and lower electrodes at said upper and lower planar surfaces, respectively, and having electrical contact with upper and lower ends of said elements, respectively, forming composite body having upper and lower planar electroded surfaces;wherein said electroded composite body includes a stiff portion extending across each of its upper and lower electroded surfaces, each of said stiff portions extending to said edge surfaces;a stress-transferring arch, having a convex shape, rigidly anchored to at least one edge of each of said stiff portions, wherein a hinge portion of said arch at said stiff portion edge has a thickness of 0-10 mm, said arch is formed of a material having a stiffness of at least Shore D 80, and said arch is shaped and disposed to direct ambient lateral stress toward said stiff portions, decoupling said ceramic elements from said ambient lateral stress and forming a stress resistant piezoelectric acoustic sensor.