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.

The present invention can provide a fiber having a further enhanced strength while serving as a ceramic fiber. To this end, a composite fiber according to the present invention a first fiber component member made of a material having a volume resistivity of 5×10.sup.−6 to 5×10 .sup.6 Ω.Math.m, or a material of a semiconductor or metalloid; and a second fiber component member comprising a ceramic material, wherein the first fiber component member and the second fiber component member are adjacent to each other such that the first and second fiber component members form a fibrous body.

Provided is an ultrasound apparatus including: a transmitter configured to generate and output a transmission signal; an ultrasound probe configured to convert the transmission signal output from the transmitter into an ultrasound signal and transmit the ultrasound signal to a target object, and receive an echo signal reflected from the target object and output a reception signal on the basis of the echo-signal; a transmission/reception switch configured to attenuate the transmission signal output from the transmitter and output the attenuated transmission signal, and output the reception signal output from the ultrasound probe; and a receiver configured to receive the attenuated and output transmission signal and the output reception signal, and detect transmission waveform information on the basis of the attenuated transmission signal.

A data link (101) for a MIMO communication system (100) comprises a first transceiver device (106A) comprising a body (109A) having a transducer mounting surface near or at which is mounted a plurality of first transducers (107A-107D) configured to, in use, receive and convert a plurality of electrical waveforms to a respective plurality of acoustic signals. A first bonding layer (120A) bonds a barrier mounting surface of the body of the first transceiver device to a barrier (103). The data link further comprises a second transceiver device (106B) comprising a body (109B) and a plurality of second transducers (107′A-107′D) configured to receive and convert the plurality of acoustic signals transmitted through the barrier to a respective plurality of electrical waveforms. A second bonding layer (120B) bonds a barrier mounting surface of the body of the second transceiver to the barrier.

Aspects of the present disclosure describe systems, methods, and structures that scavenge mechanical energy to provide electrical energy to a wearable, where the mechanical energy is scavenged by a bending-strain-based transducer that includes a non-resonant energy harvester. By employing a non-resonant energy harvester that operates in bending mode, more electrical energy can be generated that possible with prior-art energy harvesters. In some embodiments, the output of a bending-strain-based transducer element is used for both energy scavenging and as a sensor signal indicative of a user parameter, such as a step, respiration rate, heart rate, weight and the like. In some embodiments, a transducer element includes a plurality of piezoelectric layers that are electrically connected in parallel to increase the energy and/or power provided by the transducer element.

An acoustic wave device fabrication method includes: forming on a piezoelectric substrate a comb-shaped electrode and a wiring layer coupled to the comb-shaped electrode; forming on the piezoelectric substrate a first dielectric film having a film thickness greater than those of the comb-shaped electrode and the wiring layer, covering the comb-shaped electrode and the wiring layer, and being made of silicon oxide doped with an element or undoped silicon oxide; forming on the first dielectric film a second dielectric film having an aperture above the wiring layer; removing the first dielectric film exposed by the aperture of the second dielectric film by wet etching using an etching liquid causing an etching rate of the second dielectric film to be less than that of the first dielectric film so that the first dielectric film is left so as to cover an end face of the wiring layer and the comb-shaped electrode.

A piezoelectric element includes: a first electrode; an oxide layer formed on the first electrode; a piezoelectric layer formed on the oxide layer and containing potassium, sodium, and niobium; and a second electrode formed on the piezoelectric layer. When a potential difference of 10 V is applied between the first electrode and the second electrode, a current density of a leak current differs by 10,000 times or more between a case in which the first electrode is set at a high potential and a case in which the second electrode is set at a high potential.

A piezoelectric device includes a support member, and a vibrating portion provided on a support surface of the support member. The vibrating portion includes, in addition to a first electrode, a piezoelectric film and a second electrode arranged in a stacking direction, an insulating film configured to increase an electric resistance value between the first and second electrodes. The first electrode is provided on the support surface of the support member, and includes an opening penetrating the first electrode in the stacking direction. The piezoelectric film is provided on the first electrode to extend across the opening. The second electrode is provided on the piezoelectric film. The insulating film is provided at a position between the first electrode and the second electrode, and at least a part of the insulating film overlaps with the opening in the stacking direction.

A piezoelectric device includes a base member, a first conductive film arranged above the base member in contact with an upper surface of the base member, a piezoelectric film arranged above the first conductive film in contact with an upper surface of the first conductive film, a second conductive film arranged on the piezoelectric film, and an insulating portion provided inside a trench penetrating through the piezoelectric film and the first conductive film. The insulating portion has a higher electrical resistivity than the piezoelectric film.

A piezoelectric substrate includes: a substrate; a first electrode formed on the substrate; and a piezoelectric layer formed on the first electrode and containing potassium, sodium, and niobium. A full width at half maximum of an X-ray intensity peak on a plane (100) of the piezoelectric layer in a Psi axis-direction scan result of an X-ray diffraction measurement in which a surface of the piezoelectric layer is irradiated with X-rays at an angle of 54.74° from a direction perpendicular to the surface is more than 0° and 1.2° or less.