There is provided a method for producing a piezoelectric element, which allows for forming a columnar microstructure with a small width and a high aspect ratio. The method is intended to produce a piezoelectric element 102 including a three-dimensional structure group 20 having a plurality of the three-dimensional structures 21 and 321 formed in a plate-like or columnar shape with a width of 30 μm or less and a height of 80 μm or more. The production method includes a first process of fabricating a plurality of plate-like or columnar precursor shapes 82a on a bulk material 81 formed of a Pb-based piezoelectric material, and a second process of reducing the width of the precursor shapes 82a to a predetermined value using an etching liquid.

A MEMS device includes a piezoelectric layer made of a piezoelectric single crystal, a first electrode on a first surface of the piezoelectric layer, and a first layer covering the first surface of the piezoelectric layer. At least a portion of the piezoelectric layer is included in a membrane portion. The first electrode is covered with the first layer and includes a recess. The piezoelectric layer includes a through hole that passes through the piezoelectric layer between a surface of the piezoelectric layer, which is opposite to the first direction, and the recess at a position corresponding to at least a portion of the first electrode.

Described embodiments provide a Micro-Electro-Mechanical System (MEMS) vibration energy harvester. The energy harvester includes a buckled multi-layer beam that includes a plurality of stacked layers. The plurality of stacked layers includes at least one piezoelectric layer. Each one of the plurality of stacked layers has a determined stress level and a determined thickness. The determined stress level includes at least a compressive stress. The plurality of stacked layers achieves a desired total stress level of the beam to achieve substantial deformation of the beam in at least one direction when a proof mass is added to the beam. In response to applied external vibrations having a vibration frequency and an acceleration amplitude, the beam deflects and deforms to provide strain to the at least one piezoelectric layer, thereby generating an electrical charge to provide a continuous power output in response to the external vibrations.

An apparatus is provided which comprises: a ferromagnetic (FM) region with magnetostrictive (MS) property; a piezo-electric (PZe) region adjacent to the FM region; and a magnetoelectric region adjacent to the FM region. An apparatus is provided which comprises: a FM region with MS property; a PZe region adjacent to the FM region; and a magnetoelectric region, wherein the FM region is at least partially adjacent to the magnetoelectric region. An apparatus is provided which comprises: a FM region with MS property; a PZe region adjacent to the FM region; a magnetoelectric region being adjacent to the FM and PZe regions; a first electrode adjacent to the FM and PZe regions; a second electrode adjacent to the magnetoelectric region; a spin orbit coupling (SOC) region adjacent to the magnetoelectric region; and a third electrode adjacent to the SOC region.

A method of fabricating a piezoelectric layer includes depositing a piezoelectric material onto a substrate in a first crystallographic phase by physical vapor deposition while the substrate remains at a temperature below 400 C., and thermally annealing the substrate at a temperature above 500 C. to convert the piezoelectric material to a second crystallographic phase. The physical vapor deposition includes sputtering from a target in a plasma deposition chamber.

A piezoelectric device includes a substrate, a thermal oxide layer on the substrate, a metal or metal oxide adhesion layer on the thermal oxide layer, a lower electrode on the metal oxide adhesion layer, a seed layer on the lower electrode, a lead magnesium niobate-lead titanate (PMNPT) piezoelectric layer on the seed layer, and an upper electrode on the PMNPT piezoelectric layer.

A process for producing a crystalline layer of PZT material, comprising the transfer of a monocrystalline seed layer of SrTiO.sub.3 material to a carrier substrate of silicon material, followed by epitaxial growth of the crystalline layer of PZT material.

A transparent optical element may include a layer of an electroactive ceramic disposed between transparent electrodes, such that the electrodes are each oriented perpendicular to a non-polar direction of the ceramic layer. Optical properties of the optical element, including transmissivity, haze, and clarity may be improved by the application of a voltage to the electroactive ceramic, and an associated phase transformation.

A piezoelectric actuator includes a substrate, and a drive structure formed on the substrate, wherein the drive structure includes a piezoelectric thin film, and an average grain size of the piezoelectric thin film is smaller than or equal to 1 m.

The present invention discloses a transparent piezoelectric single crystal with high piezoelectricity and a preparation method thereof, a photoacoustic transducer, a transparent actuator and an optical-electro-mechanical coupling device prepared from the transparent piezoelectric single crystal with high piezoelectricity. The piezoelectric single crystal is a binary/ternary relaxor-PT based ferroelectric crystal poled by an AC electric field, and has ultrahigh piezoelectricity and excellent transparency.