A method of manufacturing a semiconductor device includes: forming a first substrate includes a membrane stack over a first dielectric layer, the membrane stack having a first electrode, a second electrode over the first electrode and a piezoelectric layer between the first electrode and the second electrode, a third electrode over the first dielectric layer, and a second dielectric layer over the membrane stack and the third electrode; forming a second substrate, including: a redistribution layer (RDL) over a third substrate, the RDL having a fourth electrode; and a first cavity on a surface of the RDL adjacent to the fourth electrode; forming a second cavity in one of the first substrate and the second substrate; and bonding the first substrate to the second substrate.

A diaphragm for a piezoelectric micromachined ultrasonic transducer (PMUT) is presented having resonance frequency and bandwidth characteristics which are decoupled from one another into independent variables. Portions of at least the piezoelectric material layer and backside electrode layer are removed in a selected pattern to form structures, such as ribs, in the diaphragm which retains stiffness while reducing overall mass. The patterned structure can be formed by additive, or subtractive, fabrication processes.

Systems and methods for the ultrasonic disruption of biofilm and algae growth on underwater structures utilize an ultrasonic actuator that produces a natural frequency in the ultrasonic range. In some embodiments, the ultrasonic actuator includes one or more piezoelectric transducers.

An acoustic lens to steer an acoustic beam includes a first structure, a second structure spaced from the first structure, an array of projections disposed between the first and second structures, each projection of the array of projections extending from the first structure toward the second structure to define a respective gap between the projection and the second structure, and an actuator configured to move the first structure, the second structure, or the array of projections for collective adjustment of the respective gaps of the array of projections. Each projection is configured to define one or more respective unit cells, each unit cell having a sub-wavelength size relative to the acoustic beam to establish an effective refractive index profile for the acoustic beam between the first and second structures. The actuator is configured such that the collective adjustment of the respective gaps varies across the array of projections to spatially modify the effective refractive index profile to steer the acoustic beam.

A mask according to an embodiment comprises: a body having a shape corresponding to a user's face; a first recess disposed on one surface of the body, opposite to the user's face; and a piezoelectric part disposed in the first recess, wherein the first recess has a shape recessed outward from the one surface of the body and is disposed in a region corresponding to at least one of the user's brow region and eye rim regions, and the piezoelectric unit protrudes beyond the one surface toward the user.

Exemplary slurry delivery assemblies may include a slurry fluid source. The assemblies may include a flurry delivery lumen having a lumen inlet and a lumen outlet. The lumen inlet may be fluidly coupled with an output of the slurry fluid source. The assemblies may include a deagglomeration tube fluidly coupled with the lumen outlet. The deagglomeration tube may include a tube inlet and a tube outlet. The assemblies may include one or more ultrasonic transducers coupled with the deagglomeration tube.

Disclosed is a connection device for piezoceramics of an ultrasonic transducer, comprising a nut (1), an ultrasonic transducer (5) having a screw structure and to be used with the nut (1), and a plurality of piezoceramics (3) and a plurality of metal sheets (4) fitted on an outer circumference of the screw of the ultrasonic transducer (5) and arranged at intervals. The connection device for the piezoceramics of the ultrasonic transducer further comprises a washer (2) located between the nut (1) and the piezoceramics (3), and the washer (2) is provided with a through hole through which the screw passes. The connection device has high connecting precision, strong working stability, and high working reliability.

Disclosed is a connection device for piezoceramics of an ultrasonic transducer, comprising a nut (1), an ultrasonic transducer (5) having a screw structure and to be used with the nut (1), and a plurality of piezoceramics (3) and a plurality of metal sheets (4) fitted on an outer circumference of the screw of the ultrasonic transducer (5) and arranged at intervals. The connection device for the piezoceramics of the ultrasonic transducer further comprises a washer (2) located between the nut (1) and the piezoceramics (3), and the washer (2) is provided with a through hole through which the screw passes. The connection device has high connecting precision, strong working stability, and high working reliability.

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 reaction compensation device includes a drive mechanism driving a first movable part with respect to a base, a reaction mass drive mechanism driving a second movable part with respect to the base; and a first relative position sensor measuring a relative position between the first movable part and the base. There is also a second relative position sensor measuring a relative position between the second movable part and the base, a first control system controlling the drive mechanism by taking in a signal outputted from the first relative position sensor as a feedback signal in response to a command value, and a second control system correcting the command value using a correction parameter for adjusting a difference between mass properties of the drive mechanism and reaction mass drive mechanism and for controlling the reaction mass drive mechanism.