A vibration device that includes an elastic plate having a first elastic plate section, a second elastic plate section opposing the first elastic plate section, and a curvature joining section connecting the first and second elastic plate sections; a piezoelectric vibration element is provided on a surface of the first elastic plate section; and a circuit is provided on the second elastic plate section. A mass addition member is attached to a leading end portion of the first elastic plate section, and the elastic plate is accommodated in a package member.

A differential amplifier generates an output voltage waveform exhibiting a slew rate over a rise time. The amplifier is powered from a dc voltage input and includes a set of differential pairs having a bias current flowing therethrough and a Miller compensation capacitance. A comparator functions to compare a voltage at the dc voltage input against a reference voltage in order to detect when the voltage drops below the reference voltage. A gain stage controls the gain of the differential amplifier and a bias current control circuit controls the bias current of the differential amplifier. In response to the detection by the comparator of the voltage dropping below the reference voltage, the gain stage and the bias current control circuit decrease the gain of the amplifier and jointly decrease the bias current in order to maintain a value of the rise time.

An apparatus may include one or more segmented piezoelectric micromechanical ultrasonic transducer (PMUT) elements. Each segmented PMUT element may include a substrate, an anchor structure disposed on the substrate and a membrane disposed proximate the anchor structure. The membrane may include a piezoelectric layer stack and a mechanical layer. The anchor structure may include boundary portions that divide the segmented PMUT element into segments. Each segment may have a corresponding segment cavity. The boundary portions may correspond to nodal lines of the entire membrane. The membrane may include a membrane segment disposed proximate each segment cavity. The membrane may be configured to undergo one or both of flexural motion and vibration when the segmented PMUT element receives or transmits signals.

Examples of portable electronic devices including a piezo actuated vibrator for providing tactile feedback to the user are described. Portable electronic devices according to the present disclosure may include tactile feedback devices, which may be driven by a piezoelectric actuator/vibrator that is operatively coupled to or embedded into the housing of a portable electronic device. In some examples, the housing of the electronic device itself can be made of piezoelectric ceramic material. The piezoelectric element may be coupled to the housing of the product to cause the housing to deflect and/or vibrate. In some examples, the housing of the portable electronic device, which may be a portable media player device, may be configured for placement directly or indirectly in contact with the user's skin such that vibrations of the housing may be felt directly (without audible feedback) by the user.

An ultrasound probe includes: a plurality of ultrasound transducers each including a diaphragm, a lower electrode laminated on a surface of the diaphragm, a piezoelectric film laminated on a surface of the lower electrode, and including an effective area in which larger vibration is caused upon piezoelectric conversion, and a reference area in which smaller vibration than that in the effective area is caused upon piezoelectric conversion, and an upper electrode laminated on a surface of the piezoelectric film; and hardware processors that correct variation in performance between the ultrasound transducers, wherein one or both of the lower electrode and the upper electrode include an effective area electrode portion, and a reference area electrode portion, and each of the hardware processors is a device that corrects one or both of an output value from the effective area electrode portion and an input value to the effective area electrode portion.

A haptic actuator assembly includes a haptic actuator configured to output displacement along a perpendicular axis and a pre-load device. The pre-load device is disposed adjacent to the haptic actuator and configured to generate a compressive load on the haptic actuator along the perpendicular axis to oppose expansion of the haptic actuator along the perpendicular axis. The haptic actuator is disposed within an enclosed cavity formed by a casing. A pressure within the enclosed cavity is varied in order to create the compressive load on the haptic actuator along the perpendicular axis. The pre-load device may alternatively be a connector component formed from a shrinkable material that is configured to longitudinally shrink to exert a force in order to create the compressive load on the haptic actuator along the perpendicular axis.

A sensor includes a lower electrode layer facing a cavity, a piezoelectric layer located on the lower electrode layer, and an upper electrode layer located on the piezoelectric layer. The piezoelectric layer includes a first piezoelectric part and a second piezoelectric part. The first piezoelectric part includes a first material having piezoelectricity and at least partially overlays the cavity when viewed on a plane. The second piezoelectric part includes a second material having piezoelectricity and being different in at least one of a g constant and d constant from the first material and, when viewed on a plane, is located in a region different from an arrangement region of the first piezoelectric part and at least partially overlays the cavity.

A transducer includes first and second piezoelectric layers made of corresponding different first and second piezoelectric materials and three or more electrodes, implemented in two or more conductive electrode layers. The first piezoelectric layer is sandwiched between a first pair of electrodes and the second piezoelectric layer is sandwiched between a second pair of electrodes. The first and second pairs of electrodes contain no more than one electrode that is common to both pairs.

An electroacoustic transduction film including a polymer composite piezoelectric body in which piezoelectric body particles are dispersed in a viscoelastic matrix formed of a polymer material having viscoelasticity at a normal temperature, and thin film electrodes respectively laminated on both surfaces of the polymer composite piezoelectric body is included, and two or more of the electroacoustic transduction films are laminated, and a gap between the adjacent electroacoustic transduction films is less than or equal to 3 cm.

A sensor pod assembly comprising a gel pad, a gel pad cap, a piezoelectric sensor, a base plate, a base plate support, a wiring harness, a battery, a noise attenuating backing, and a charging component; said gel pad comprising a top and bottom, said bottom having a flat bottom and a concave recess; said flat bottom acoustically contacting said piezoelectric sensor; said piezoelectric sensor secured to a first side of said base plate support, and a second side of said base plate support secured to said base plate, a wiring harness and a battery connected to said base plate, and a charging component having exposed annular rings on the exterior side of said sensor pod assembly; a noise attenuating backing compressing the charging component against the base plate; and a gel pad cap having an outer face and an inner face, said inner face in contact with said base plate support.