A piezoelectric device includes a base and a laminated portion. The laminated portion includes, at least above a recess, a piezoelectric layer, a pair of electrode layers to apply a voltage to the piezoelectric layer, and a membrane covering the recess. The membrane includes a piezoelectric membrane, in the piezoelectric layer, that swells on at least one of a side of the recess and a side opposite to the side of the recess.

In a piezoelectric device, electrode layers are spaced apart from each other in the direction of the normal thereto. A first piezoelectric layer is interposed between two electrode layers of electrode layers in the direction of the normal. A second piezoelectric layer is provided on an opposite side of the first piezoelectric layer from a base portion. The second piezoelectric layer is interposed between two electrode layers of the electrode layers in the direction of the normal. The half-width of a rocking curve measured by X-ray diffraction for a lattice plane of the first piezoelectric layer substantially parallel to a first main surface is smaller than a half-width for the second piezoelectric layer. The piezoelectric constant of a material defining the first piezoelectric layer is smaller than the piezoelectric constant of a material defining the second piezoelectric layer.

In a piezoelectric device, electrode layers are spaced apart from each other in the direction of the normal thereto. A first piezoelectric layer is interposed between two electrode layers of electrode layers in the direction of the normal. A second piezoelectric layer is provided on an opposite side of the first piezoelectric layer from a base portion. The second piezoelectric layer is interposed between two electrode layers of the electrode layers in the direction of the normal. The half-width of a rocking curve measured by X-ray diffraction for a lattice plane of the first piezoelectric layer substantially parallel to a first main surface is smaller than a half-width for the second piezoelectric layer. The piezoelectric constant of a material defining the first piezoelectric layer is smaller than the piezoelectric constant of a material defining the second piezoelectric layer.

A piezoelectric device includes a membrane portion including a through slot extending through the membrane portion in an up-down direction. A width of the through slot in a single crystal piezoelectric material layer becomes narrower as the through slot extends downward. In the single crystal piezoelectric material layer and a reinforcing layer, a maximum width of the through slot in a layer located on a bottom side is smaller than a minimum width of the through slot in a layer located on a top side.

Smart dental implant systems and methods for ambulatory dental care are provided. In some embodiments, the disclosed subject matter includes a crown, adapted to mimic a patient's anatomy and location of the smart dental implant system. The crown can include piezoelectric nanoparticles, disposed on a surface of the crown and adapted to generate electricity from a patient's oral motion. In some embodiments, the disclosed subject matter includes an abutment, coupled to the crown. The abutment can include an energy harvesting circuit, operationally coupled to the piezoelectric nanoparticles and adapted to harvest the electricity, and a micro LED array, operationally coupled to the energy harvesting circuit and adapted to photobiomodulate surrounding peri-implant soft tissue.

Doped-aluminum nitride (doped-AlN) films and methods of manufacturing doped-AlN films are disclosed. Some methods comprise forming alternating pinning layers and doped-AlN layers including a dopant selected from the group consisting of Sc, Y, Hf, Mg, Zr and Cr, wherein the pinning layers pin the doped-AlN layers to a c-axis orientation. Some methods include forming a conducting layer including a material selected from the group consisting of Mo, Pt, Ta, Ru, LaNiO.sub.3 and SrRuO.sub.3. Some methods include forming a thermal oxide layer having silicon oxide on a silicon substrate. Piezoelectric devices comprising the doped-AlN film are also disclosed.

A polymer composite exhibiting piezoelectric properties can be formed for flexible and/or thin film applications, in which the polymer composite includes a polymer matrix and a piezoelectric ceramic filler embedded in the polymer matrix. The polymer matrix may include at least two polymers: a first polymer and a second polymer. The first polymer may be a fluorinated polymer, and the second polymer may be compatible with the first polymer and have a dielectric constant of less than approximately 20. The piezoelectric ceramic filler may be a lead-free ceramic filler, such as barium titanate, and be approximately 40-70% by volume of the polymer composite. The remaining 30-60% by volume may be the polymer matrix, which may itself be approximately 5-20% by weight second polymer and 80-95% fluorinated polymer.

There is provided a piezoelectric laminate has, on a substrate in the following order, a lower electrode layer and a piezoelectric film containing a perovskite-type oxide as a main component. The piezoelectric film has an oxygen-deficient region in a region in contact with the lower electrode layer. In a case where an average value of oxygen amounts in a region centrally located among three regions obtained by dividing the piezoelectric film into three equal parts in a thickness direction is denoted as a first average oxygen amount, and an average value of oxygen amounts in the oxygen-deficient region is denoted as a second average oxygen amount, a ratio R of the second average oxygen amount to the first average oxygen amount is less than 0.97. A thickness of the oxygen-deficient region is 120 nm or more and is ⅓ or less of a thickness of the entire piezoelectric film.

Embodiments relate to a piezoelectric ceramic and methods of making the same that is suitable for use as a high-power piezoelectric ceramic, and in particular a piezoelectric ceramic that exhibits both good hard properties and good soft properties. Embodiments involve generating the piezoelectric ceramic via the combination of chemical modification/doping and/or a texturing method so that the piezoelectric material exhibits a large figure of merit, as well as other hard and soft properties. The chemical modification involves Cu and Mn doping a piezoelectric material composition having a relaxor-lead titanate based ferroelectric structure. The texturing involves templated grain growth (TGG) texturing using a BaTiO.sub.3 (BT) template.

An electronic device includes a microelectromechanical system (MEMS) rectifier. The MEMS rectifier includes a mainboard and a sub-board. The mainboard has one or more radiofrequency (RF) inputs configured to receive an RF signal, and a first electrical contact. The sub-board is positioned parallel to the mainboard with a gap in-between, and has a thin film piezoelectric layer, a second electrical contact positioned opposite the first electrical contact, and a ground plane. The sub-board is configured to vibrate as the RF signal is received at the one or more RF inputs, and the thin film piezoelectric layer is configured to generate energy due to the vibration and piezoelectric properties of the thin film piezoelectric layer.