Examples include a device including a nanovoided polymer element having a first surface and a second surface, a first plurality of electrodes disposed on the first surface, a second plurality of electrodes disposed on the second surface, and a control circuit configured to apply an electrical potential between one or more of the first plurality of electrodes and one or more of the second plurality of electrodes to induce a physical deformation of the nanovoided polymer element.

A method of forming a microphone device includes: forming a through-hole in a substrate wafer; providing a second wafer; bonding the second wafer to the substrate wafer; and forming a top electrode over a first surface of a single-crystal piezoelectric film of the second wafer. The second wafer may include the single-crystal piezoelectric film. The single-crystal piezoelectric film may have a first surface and an opposing second surface. The second wafer may further include a bottom electrode arranged adjacent to the second surface, and a support member over the single-crystal piezoelectric film. The through-hole in substrate wafer may be at least substantially aligned with at least one of the top electrode and the bottom electrode.

Provided are a piezoelectric material, a piezoelectric member, a piezoelectric element and a pressure sensor that can be used in high-temperature environments. The piezoelectric material is composed of Sr-substituted akermanite represented by Ca.sub.(2-x)Sr.sub.xMgSi.sub.2O.sub.7 (0.1≤x≤0.6).

A transducer includes: a film support portion having a hollow portion; a vibration film displaceable in a film thickness direction; a piezoelectric element, the piezoelectric element including a pair of electrodes and a piezoelectric film; and in regions overlapping the hollow portion, a plurality of first regions having a first total film thickness which is a sum of a film thickness of the vibration film and a film thickness of the piezoelectric element, and a plurality of second regions having a second total film thickness which is a sum of a film thickness of the vibration film and a film thickness of the piezoelectric element, the second total film thickness being different from the first total film thickness. The first regions and the second regions are alternately arranged, and one of the first regions is adjacent to a connection portion between the film support portion and the vibration film.

A medical, particularly a dental or dental surgical, ultrasonic treatment device for generating ultrasonic vibrations and transmitting the ultrasonic vibration to a tool, which can be connected to the ultrasonic treatment device, the medical ultrasonic treatment device having: an ultrasonic vibration generator with a plurality of piezoelectric elements to which an electric voltage can be applied, and a circuit board to supply the plurality of piezoelectric elements with the electric voltage. Furthermore, a method for manufacturing a corresponding medical ultrasonic treatment device is described.

Highly deformable heterostructures utilizing liquid metals and nanostructures that are suitable for various applications, including but not limited to stretchable electronic devices that can be worn, for example, by a human being. Such a deformable heterostructure includes a stretchable substrate, a conductive liquid metal on the substrate, and nanostructures forming a solid-liquid heterojunction with the conductive liquid metal.

In an acoustic wave device, an antenna end resonator that is electrically closest to a first terminal is a first acoustic wave resonator. In each of the first acoustic wave resonator and a second acoustic wave resonator, a thickness of a piezoelectric layer is about 3.5λ or less when a wavelength of an acoustic wave is denoted as λ. The first acoustic wave resonator and the second acoustic wave resonator satisfy at least one of a first condition, a second condition, and a third condition. The first condition is a condition that the first acoustic wave resonator further includes a dielectric film provided between the piezoelectric layer and an interdigital transducer electrode, and the second acoustic wave resonator does not include the dielectric film.

A piezoelectric actuator assembly is described. The assembly including a first layer including a top and a bottom surfaces. The assembly including a second layer having a top and a bottom surfaces, the bottom surface of the second layer is disposed over the top surface of the first layer. The assembly including a third layer having a top and a bottom surfaces, the bottom surface of the third layer is disposed over the top surface of the second layer. The assembly includes a first electrode, a second electrode, a third electrode, and a fourth electrode. The third electrode is configured to be shorter than the second electrode such that the active PZT length of the second layer and the third layer is shorter than the active PZT length of the first layer.

A vibration generating device includes: a vibrator; and a piezoelectric actuator. The vibrator has a first main surface and a second main surface on a side opposite to the first main surface. The piezoelectric actuator is joined to the second main surface. A plurality of recessions and projections is formed at equal intervals on the first main surface. The vibration generating device is configured to be capable of presenting a haptic sensation while preventing a contact sound from being generated.

A laminated piezoelectric element 10 includes: a laminated body 11 in rectangle shape formed by alternately laminating a plurality of piezoelectric layers 15 and one or more internal electrode(s) 13; a connection electrode 14 connected to one end portion 13a of the internal electrode(s) 13; and an electric field relaxation region 16c or 16d formed discontinuously with regard to the internal electrode(s) 13 in at least one of two corner portions 13c and 13d of the other end portion 13b opposite to the one end portion 13a of the internal electrode(s) 13.