An acoustic wave device includes a piezoelectric substrate made of LiNbO.sub.3 or LiTaO.sub.3 and including first and second main surfaces that face each other, a functional electrode provided on the first main surface of the piezoelectric substrate to excite acoustic waves, and a Li.sub.2CO.sub.3 layer provided on the second main surface of the piezoelectric substrate.

There is provided a control method for a piezoelectric driving device including a vibrating body including a piezoelectric element for driving and configured to vibrate when a driving signal is applied to the piezoelectric element for driving, a section to be driven that is driven by the vibration of the vibrating body, and a driving-signal generating section configured to generate the driving signal using a pulse signal generated based on a target pulse duty ratio. When the target pulse duty ratio is smaller than a predetermined value, the driving signal generated by the driving-signal generating section is an intermittently generated periodic signal.

A power factor improvement and power generation apparatus using a piezoelectric element may include: a first piezoelectric element having first and second electrodes, and vibrating when voltage is applied from a power line; and a second piezoelectric element having first and second electrodes, and generating electricity in accordance with vibration of the first piezoelectric element. This apparatus is possible to improve a power factor of a power line and generate power using the inherent condenser component, which a piezoelectric element has, instead of a power factor compensation condenser, and it is also possible to generate power.

Circuitry for estimating a displacement of a piezoelectric transducer in response to a drive signal applied to the piezoelectric transducer, the circuitry comprising: monitoring circuitry configured to be coupled to the piezoelectric transducer and to output a sense signal indicative of an electrical signal associated with the piezoelectric transducer as a result of the drive signal; wherein the circuitry is configured to generate a difference signal based on the drive signal and the sense signal; and wherein the circuitry further comprises processing circuitry configured to apply at least one transfer function to the difference signal to generate a signal indicative of the displacement of the piezoelectric transducer.

A substrate having a recessed portion, a diaphragm, and a piezoelectric actuator are provided, the diaphragm includes a first layer containing silicon as a constituent element, and a third layer disposed between the first layer and the piezoelectric actuator and containing zirconium as a constituent element, and a laminated side surface of the first layer and the third layer is covered with a moisture-resistant protective film containing at least one selected from the group made of oxide, nitride, metal, and diamond-like carbon.

A solid-state battery cell includes a cathode region, an anode region, a separator interconnecting the cathode region and the anode region, a cathode current collector on a surface of the cathode region, an anode current collector on a surface of the anode region, a first piezoelectric layer on a surface of the cathode current collector, and a second piezoelectric layer on a surface of the anode current collector. A method of operating a solid-state battery cell includes detecting a material change in the anode or the cathode, applying a voltage to the first piezoelectric material layer or the second piezoelectric material layer, and generating a pressure against the cathode current collector or the anode current collector by the first piezoelectric material layer or the second piezoelectric material layer, the pressure being generated as a result of the applied voltage.

A vibration device includes a piezoelectric vibrator having a piezoelectric element and a diaphragm having a pair of main surfaces facing each other, the piezoelectric element being bonded to the main surface, a vibration member where the piezoelectric vibrator is disposed, and an adhesive member disposed between the diaphragm and the vibration member and bonding the diaphragm and the vibration member. Each of the pair of main surfaces of the diaphragm has a rectangular shape when viewed from a facing direction of the pair of main surfaces, and the adhesive member is disposed in a facing manner on at least a pair of sides of the main surfaces.

An actuator has a plurality of pairs of a flexible electrode having flexibility, and a base electrode having an opposed face that is opposed to the flexible electrode and is covered with an insulating layer. The flexible electrode is configured to deform to get closer to the opposed face when a voltage is applied to the flexible electrode and the base electrode. Each of the pairs is located on the same axis, and adjacent ones of the pairs are connected to each other. The axis intersects with the opposed face of the base electrode of each of the pairs. The base electrode of each of the pairs is divided into a plurality of electrode portions insulated from each other, and the voltage is individually applied to the electrode portions.

An actuator has a flexible electrode having flexibility, and a base electrode having an opposed face that is opposed to the flexible electrode and is covered with an insulating layer. The flexible electrode deforms to get closer to the opposed face when a voltage is applied to the flexible electrode and the base electrode. The flexible electrode is a rotating body placed on the opposed face. The base electrode is divided into a plurality of electrode portions insulated from each other. The electrode portions are arranged along a predetermined direction. The flexible electrode moves in the predetermined direction relative to the base electrode, while rotating on the opposed face, when the voltage is sequentially applied to the electrode portions in the predetermined direction.

An intraocular lens (IOL) has a clear optic and means for actuating change in curvature in at least a portion the clear optic. The intraocular lens (IOL) can have anterior and posterior portions spaced apart by a cavity, and an actuator for urging change in curvature in at least one of said portions, with energy provided by an energy harvesting mechanism incorporated into haptics of said IOL.