USA as Represented by Secretary of the Navy

Ahmed H Amin

Peter Finkel

Colin J Murphy

Kim C Benjamin

Marilyn Wun-Fogle

James B Restorff

Kenji Uchino

Joseph J Stace

Wen D Wong

Yuan Zhuang

Seyit O Ural

Christopher S Lynch

An energy harvesting device for harvesting energy from a moving structure includes a housing allowing transmission of magnetic fields therethrough. A piezoelectric material capable of a phase transition and a magnetostrictive material capable of a structural change when subjected to a magnetic field are mechanically coupled to each other in the housing. An adjustable pre-stress means is positioned between the housing and the combination of the piezoelectric and magnetostrictive materials. Electrical contacts are positioned on the piezoelectric material. A magnet is mounted on the moving structure. The housing is mounted in sufficient proximity to the magnet for the magnetic field of the magnet to induce the structural change in the magnetostrictive material.

Magnetoelectric energy harvesting

A transducer for generating electrical energy from an expected force includes a single crystal ferroelectric material having a phase transition stress level. Mechanical stress is provided to this crystal at a level approaching the phase transition stress level, such that the expected external force will cause the phase transition. At least two electrodes are joined to the single crystal for receiving electrical energy created by the phase transition. The electrodes can be joined to conditioning and storage circuitry. In further embodiments, the phase transition is induced by an expected temperature change.

Energy harvesting utilizing stress induced phase transformation in ferro-electric piezocrystals

A piezoelectric transducer includes a single crystal piezoelectric material having a phase transition from one crystalline phase to a second crystalline phase at a predetermined stress level. A pre-stress is applied to the single crystal piezoelectric material so that the material is maintained near its phase transition point. An electrical field source is joined to the material such that, in cooperation with the pre-stress, an increase or decrease in the electrical field causes a crystalline phase transition in the single crystal piezoelectric material. Crystalline phase transition induces strain larger by an order of magnitude than that caused by the non-phase transition piezoelectric effect.

Crystalline relaxor-ferroelectric phase transition transducer

A piezoelectric transformer includes a single crystal relaxor ferroelectric element poled along a [01] direction and selected from the group consisting of PZN-PT, PMN-PZT, PZN-PT and PMN-PT. The element has two opposed surfaces substantially perpendicular to the [01] direction with an input electrode and an output electrode positioned on one surface. The output electrode is isolated from electrical communication with the input electrode. A ground electrode is positioned on the second, opposed surface. Input electrical energy results in piezoelectric change in the element that is mechanically coupled through the element to generate piezoelectric output energy.

High power single crystal piezoelectric transformer

A pressure sensor includes a substrate having a top metallized pad formed on the top surface and a bottom metallized pad formed on the bottom surface. These pads are divided into segments for connection with piezoresistors. A sensing piezoresistor is formed on the substrate's top surface in order to respond to a pressure of interest. A reference piezoresistor is formed on the substrate's bottom surface to respond to a reference pressure. A conductive strip is joined between the two piezoresistors for conducting heat and electricity therebetween. A temperature measuring resistor can also be positioned on the substrate. The substrate and sensors can be positioned in a housing having electrical contacts in communication with the sensors for providing voltages in response to changing pressure differentials and temperatures.

Growing community of inventors

North Attleboro, MA, United States of America

Ahmed H Amin