Virginia Tech Intellectual Properties Inc

Dwight Viehland

Shuxiang Dong

Jie-Fang Li

Jiefang Li

Shu-Xiang Dong

Junyi Zhai

An ME composite laminate of at least one (1-3) piezo-fiber layer coupled with high-permeability alloy magnetostrictive layers, optionally formed of FeBSiC or equivalent. The composite laminate alternates the (1-3) piezo-fiber and high-permeability alloy magnetostrictive layers in a stacked manner. Optionally, the magnetization direction of the high-permeability alloy magnetostrictive layers and polarization direction of the piezo-fiber layer are an (L-L) arrangement. Optionally, thin film polymer layers are between the (1-3) piezo-fiber layer and high-permeability alloy magnetostrictive layers. Optionally, piezo-electric fibers within the (1-3) piezo-fiber layer are poled by inter-digitated electrodes supported by the thin film polymer, arranged as alternating symmetric longitudinally-poled 'push-pull' units.

Method and Apparatus for High-Permeability Magnetostrictive/Piezo-Fiber Laminates Having Colossal, Near-Ideal Magnetoelectricity

A method and apparatus attains high voltage gain by using a composite structure of an elastic section of piezoelectric layers bonded between magnetic and electric sections of magnetostrictive layers, with a harmonic magnetic field being applied along the layers at a mechanical resonance frequency of the composite structure, through coils around the laminate carrying current, such as to produce a continuity of both magnetic and electric flux lines, and achieving a high voltage output.

Method and apparatus for high voltage gain using a magnetostrictive-piezoelectric composite

A magnetoelectric magnetic field sensor has one or more laminated magnetostrictive layers and piezoelectric layers. The magnetostrictive layers are magnetized by a bias magnetic field in a longitudinal, in-plane direction. The piezoelectric layers can be poled in the longitudinal direction or perpendicular direction. The longitudinal magnetization of the magnetostrictive layers provides greatly increased sensitivity at lower bias fields compared to other magnetoelectric sensors. Perpendicular poling of the piezoelectric layers tends to provide higher sensitivity at lower detection frequency (e.g. less than 1 Hz). Longitudinal poling tends to provide higher sensitivity at high detection frequency (e.g. above 10 Hz). Also included are embodiments having relative thicknesses for the magnetostrictive layers that are optimized for sensitivity. Equations are provided for calculating the best relative thickness for the magnetostrictive layer for maximum sensitivity.

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Blacksburg, VA, United States of America

Dwight Viehland