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:
Apr. 20, 1999
Filed:
Dec. 23, 1993
George Raymond Dvorsky, Manhattan Beach, CA (US);
David Wayne Love, Lakewood, CA (US);
TRW Inc., Redondo Beach, CA (US);
Abstract
A piezoelectric actuator/sensor package and corresponding method for its fabrication, and a method of embedding a ceramic actuator/sensor in a laminated structural member, such as a graphite-epoxy laminate. A ceramic actuator/sensor, with lead wires first bonded to it, is encapsulated in a non-conductive fiber composite material, such as fiberglass cloth and epoxy, to form a package that is precured at a suitable temperature, typically room temperature. Encapsulation provides electrical insulation, good strain coupling, protection from mechanical damage, and reduction in thermal stresses, since the coefficient of thermal expansion of the encapsulating material is selected to be between those of the ceramic and the graphite-epoxy laminate. Graphite fibers may be added to the package to enhance voltage-strain performance. The package is embedded in the structural laminate and the composite structure is cured in a manner that minimizes thermally-induced stresses. Piezoelectric prestressing, during the embedment step, may be used to further reduce the effects of thermal stresses.