Aspects of this disclosure relate to a capacitive micromachined ultrasonic transducer (CMUT) with a contoured electrode. In certain embodiments, the CMUT has a contoured electrode. The electrode may be non-planar to correspond to a deflected shape of the outer plate. A change in distance between the electrode and the plate after deflection may be greater than a minimum threshold across the width of the CMUT.

A vibrating device includes a tubular body including first and second end surfaces, and a side wall portion that connects the first and second end surfaces, a piezoelectric vibrator provided on the first end surface of the tubular body, and a light transmitting body that is directly or indirectly connected to the second end surface and covers an opening in the second end surface of the tubular body. A connecting portion is connected to the first end surface of the tubular body inside or outside an opening in the first end surface. A tubular bent portion is connected to a surface of the connecting portion that faces toward the second end surface of the tubular body. The tubular bent portion extends in a direction from the first end surface toward the second end surface of the tubular body.

An electromechanical transducer element includes a base substrate, a first electrode on the base substrate, a piezoelectric body on the first electrode, and a second electrode on the piezoelectric body. The base substrate has a void area opposite to the piezoelectric body via the first electrode, and a width of the void area on a cross section cut along a layer direction of the electromechanical transducer element satisfies 0.65≤Pw/Cw≤0.95, where Cw represents the width of the void area, and Pw represents a width of the piezoelectric body on the cross section.

A vibration device includes a light transmissive body, a first cylindrical body, a plate-shaped spring portion, a second cylindrical body, and a vibrating body. The light transmissive body includes a main body portion on an inner side of a portion supported by the first cylindrical body, and a protruding portion extending from the main body portion toward an outer circumference of the light transmissive body and protruding outward more than a portion supported by the first cylindrical body. A ratio between an equivalent mass calculated from a moment of inertia of the protruding portion and a weight of the main body portion is about 0.8 to about 1.2, and a resonant frequency of the light transmissive body is larger than a resonant frequency of the spring portion.

A vibrating device includes a translucent cover, an ejector to eject a liquid onto the surface of the translucent cover, and a first vibrating portion to vibrate the translucent cover at a vibration acceleration of larger than about 8.0×10.sup.5 m/s.sup.2 and equal to or smaller than about 21.0×10.sup.5 m/s.sup.2.

A piezoelectric micromachined ultrasonic transducer (pMUT) device may include a piezoelectric membrane transducer designed to have lower sensitivity to residual stress and reduced sensitivity to geometric variations arising from the backside etching process used to release the membrane. These designs allow some of its key feature to be adjusted to achieve desired characteristics, such as pressure sensitivity, natural frequency, stress sensitivity, and bandwidth.

A sound transducer, in particular, for an ultrasonic sensor, includes a functional group, the functional group including a diaphragm cup and at least one electroacoustic transducer element. The sound transducer also includes a housing. The diaphragm cup includes a vibratory diaphragm and a circumferential wall, and at least one electroacoustic transducer element, the transducer element being configured to stimulate the diaphragm to vibrate and/or to convert vibrations of the diaphragm into electrical signals. The diaphragm cup is formed from a plastic material, the at least one transducer element being integrated into the vibratory diaphragm, in particular without an additional adhesive layer, the transducer element including a piezoceramic element.

A piezoceramic ultrasonic transducer for a vehicle includes: a disc-shaped piezoceramic oscillator configured to generate ultrasonic waves; a printed circuit board configured to provide electric power to the disc-shaped piezoceramic oscillator; and a composite elastomeric element arranged between the disc-shaped piezoceramic oscillator and the printed circuit board, the composite elastomeric element being configured to support the piezoceramic oscillator on the printed circuit board. The composite elastomeric element includes a first elastomeric compound element and a second elastomeric compound element. The first elastomeric compound element includes a first temperature dependent viscoelasticity and supports the piezoceramic oscillator on the printed circuit board in a first temperature range and the second elastomeric compound element includes a second temperature dependent viscoelasticity and supports the piezoceramic oscillator on the printed circuit board in a second temperature range different from the first temperature range.

This document describes a single-element planar focused ultrasonic transducer with electrically tunable focal size (focal diameter in the focal plane), through modifying the design of a self-focusing acoustic transducer (SFAT). The transducer is built on a 1-mm-thick lead zirconate titanate (PZT) with (1) Fresnel acoustic lens formed with annular rings of air cavities on the top and (2) patterned annular ring electrodes on the bottom. By controlling the number of Fresnel rings being driven from the center, we were able to tune the focal size between 371 and 866 μm, while keeping the focal length at 6 mm, with 2.32 MHz pulsed ultrasound. When tested as a droplet ejector, the transducer ejected water droplets with diameter between 294 and 560 μm (between 13.3 and 92.0 nL in volume), depending on which set of electrodes are actuated.

A vibrating device includes a dome-shaped cover, a cylindrical or substantially cylindrical vibrating body, and a piezoelectric element. The dome-shaped cover is disposed so as to include a detection field of an optical detector element, and the cylindrical or substantially cylindrical vibrating body is fixed to the cover. The piezoelectric element is fixed to the vibrating body and vibrates the cover via the vibrating body. The vibrating body includes a cylinder portion, a first connection portion connected to a first end portion of the cylinder portion, a first ring-shaped portion connected to the first connection portion at a position near the cover, a second connection portion connected to a second end portion of the cylinder portion, and a second ring-shaped portion connected to the second connection portion at a position opposite to a surface to which the cylinder portion is connected.