The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 24, 1998
Filed:
Apr. 28, 1997
Leslie J Bowen, Concord, MA (US);
Craig D Near, Acton, MA (US);
Materials Systems Incorporated, Littleton, MA (US);
Abstract
A transducer including a ceramic body having a base and an array of tube-shaped piezoelectric or electrostrictive ceramic elements integral with the base. A first electrode contacts the tube wall inner surface, while a second electrode contacts the tube wall outer surface and is electrically isolated from the first electrode and from the lower surface of the transducer. The first electrode extends onto the transducer lower surface for electrical connection to a power source for driving the transducer across the tube walls for d.sub.31 mode vibration of the tube walls. A stiff cover plate may be used to transmit the tube wall vibration to a desired medium. The ceramic base may be removed if an electrically insulating layer is provided between the elements at the lower surface of the transducer. The insulating layer and tube wall upper edges then electrically isolate the second electrode from the first electrode and the transducer lower surface. In this alternative, the first and second electrodes are provided by a stiff conductive polymer matrix filling the tube-shaped elements and spaces between the elements. The matrix upper surface transmits the tube wall vibration to a desired medium without a cover plate. The first electrode extends onto the composite body lower surface for electrical connection to a source of electric power for driving the transducer across the tube walls for d.sub.31 mode vibration of the tube walls. A net-shape molding method for producing the transducer is also described.