Accession Number : ADD018109

Title :   Actuators with Graded Activity.

Descriptive Note : Patent, Filed 23 Dec 94, patented 21 May 96,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Kahn, Manfred ; Matic, Peter ; Kirby, George C , III

Report Date : 21 May 1996

Pagination or Media Count : 10

Abstract : A method for reducing and/or shifting stress in at least one outer end portion of an actuator made from a piezoelectric material. The actuator is affixed to a substrate by an adhesive bond and adapted to cycle between an expanded and contracted positions, which creates stresses in the actuator and in the bond. The method includes the step of doping at least one outer portion of the actuator with a metal oxide to reduce piezoelectric activity therein. in a preferred embodiment, the doped outer portion has a gradient composition varying from the maximum at the end of the actuator to essentially zero concentration at a point inward of the end. The system includes a doped piezoelectric actuator adhesively bonded to a substrate and electrodes attached to the actuator for receiving electrical energy the actuator containing a metal oxide dopant in the outer portions thereof.

Descriptors :   *ACTUATORS, *PATENTS, STRESSES, SUBSTRATES, BONDED JOINTS, SHIFTING, PIEZOELECTRIC MATERIALS, DOPING, ADHESIVE BONDING

Subject Categories : Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE