Piezoelectric structures

US7166952B2 · kind B2 · utility

Assignee

• 1 . . . Limited · GB

Inventors

• Richard J. Topliss · Campbell, US
• David Livingstone
• Andrew Matheson · Belmont, US
• Gareth McKevitt · Cambridge, GB
• Mark Shepherd · Royston, GB
• Anthony Hooley · Cambridge, GB

Key dates

• Filing date: Sep 26, 2002
• Grant date: Jan 23, 2007
• Expiry date: Sep 29, 2022

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10N30/2048

Abstract

An equivalent to the spatial separation either side of a nominal median plane that is inherent in a bimorph (with one piezoelectric layer on one side, and the second on the other side of the plane) is attained by structurally shaping the cross-section of a simple, single piezoelectric layer (11) such that it has a multiplicity of piezoelectric portions arranged in two generally-planar groups one either side of a median plane, so that any dimension change undergone by a portion on one side of that plane will tend to bend the whole device in the opposite direction to the same sense dimension change undergone by a portion on the other side of that plane. The simple, single layer acts as though it were a bimorph if elongate and beam-like, bending along its length, one end moving up/down, or back/forth, relative to the other but with any need for an internal, electrode.