Described herein is mechanically decoupling of an electromechanical transducer from a common substrate, enabling multiple transducers to be surface mounted to a common substrate such as a printed circuit board (PCB) without experiencing mechanical cross-coupling. The decoupling of the transducer from the substrate enables the transducers to be attached without reducing the efficiency of acoustic transduction. The design of the mount enables it to be assembled in an automated manner with pick and place tools.

A vibration wave motor includes an element configured to be displaced by application of voltage, and an annular elastic body having a bottom surface coming into contact with the element and a drive surface having a groove, configured to drive a moving element by a vibration wave produced on the drive surface by displacement of the element. The element has a density of 4.2 to 6.0×10.sup.3 kg/m.sup.3. A value of [(T/B)÷W] is in a range of 0.84 to 1.94, where T represents a depth of the groove, B represents a distance from a bottom part of the groove to the bottom surface, and W represents a radial width of the elastic body.

Provided is a piezoelectric ceramics having a gradual change in piezoelectric constant depending on an ambient temperature. Specifically, provided is a single-piece piezoelectric ceramics including as a main component a perovskite-type metal oxide represented by a compositional formula of ABO.sub.3, wherein an A site element in the compositional formula contains Ba and M.sub.1, the M.sub.1 being formed of at least one kind selected from the group consisting of Ca and Bi, wherein a B site element in the compositional formula contains T1 and M.sub.2, the M.sub.2 being formed of at least one kind selected from the group consisting of Zr, Sn, and Hf, wherein concentrations of the M.sub.1 and the M.sub.2 change in at least one direction of the piezoelectric ceramics, and wherein increase and decrease directions of concentration changes of the M.sub.1 and the M.sub.2 are directions opposite to each other.

There is provided a piezoelectric actuator, including: a vibration plate; a first piezoelectric body; a second piezoelectric body; a first electrode disposed on a first surface of the first piezoelectric body; a second electrode disposed on a second surface of the second piezoelectric body; an intermediate electrode disposed on an intermediate surface of the first piezoelectric body and overlapping with the first and second electrodes; an intermediate trace connected to the intermediate electrode on the intermediate surface and drawn out to one side in a first direction beyond the first piezoelectric body and the second piezoelectric body; a first trace overlapping with the intermediate trace in the thickness direction and being conducted with the intermediate trace; and a second trace overlapping with the intermediate trace in the thickness direction and being conducted with the intermediate trace.

A piezoelectric element drive circuit includes a piezoelectric element driven at a predetermined frequency and having a resonant frequency of (2n+1) times the predetermined frequency (n is a predetermined natural number), and a drive voltage generator that has a first output terminal connected to a first terminal of the piezoelectric element and a second output terminal connected to a second terminal of the piezoelectric element. When the piezoelectric element is driven, a waveform of potential difference between the first output terminal and the second output terminal is a step wave which transitions while taking an intermediate potential. A time length for which the potential difference is the intermediate potential is around (t2−t1)/(2n+1) in a period of time from time t.sub.1 at which the potential difference falls to the intermediate potential to time t.sub.2 at which the potential difference falls to the intermediate potential subsequently.

An acoustic transducer, in particular for an ultrasonic sensor, is proposed. The acoustic transducer has a functional group, the functional group encompassing a diaphragm cup and at least one electroacoustic transducer element. The acoustic transducer furthermore has a housing. The diaphragm cup encompasses a vibration-capable diaphragm and an encircling wall, as well as at least one electroacoustic transducer element, the transducer element being embodied to excite the diaphragm to vibrate and/or to convert vibrations of the diaphragm into electrical signals. The diaphragm cup is constituted from a plastic material, the at least one transducer element being integrated into the vibration-capable diaphragm, the transducer element having an electrically active polymer.

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 piezoelectric component that has a piezoelectric element including a piezoelectric ceramic layer and a sintered metal layer on at least a first main surface of the piezoelectric ceramic layer and containing a non-precious metal, and a protective layer containing an elastic body covering first and second opposed main surfaces of the piezoelectric element. The piezoelectric ceramic layer contains 90 mol % or more of a perovskite compound that contains niobium, an alkali metal, and oxygen. A thickness of the piezoelectric element is 100 μm or less.

A solid-state quantum memory includes a vibrator supported in a displaceable (vibratable) manner on a substrate and a vibration exciter configured to excite the vibrator to vibrate. A rare-earth element is introduced into the vibrator and the introduced rare-earth element forms an electronic two-level system in the vibrator. The vibrator is supported on the substrate by a support. The substrate including a piezoelectric element formed from a piezoelectric material, as well as a first electrode and a second electrode formed by sandwiching the piezoelectric element, serves as the vibration exciter.

In a reservoir element that has a plurality of vibrators, at least one of the plurality of vibrators has a vibration state that is different from the vibration states of the other vibrators. The vibrations of the plurality of vibrators are configured to affect each other.