In a chip-on-array approach, acoustic and electronic modules are separately formed. The acoustic stack is connected to one interposer, and the electronics are connected to another interposer. Different connection processes (e.g., using low temperature bonding for the acoustic stack and higher temperature-based interconnect for the electronics) may be used. This arrangement may allow for different pitches of the transducer elements and the I/O of the electronics by staggering vias in the interposers. The two interposers are then connected to form the chip-on-array.

The present inventors have recognized that an electrical switch for opening doors in buildings, calling elevators, and the like can be improved to require less physical contact, larger activation area, and multiple activation methods, with increased reliability, by utilizing a piezoelectric sensor specifically arranged between rigid, parallel mounting plates in which one of the plates (an inner plate) is rigidly fixed to prevent movement while the other plate (an outer plate) is accessible for receiving physical contact. By rigidly fixing the inner plate, such as by mounting to a wall or bollard, the sensor can react with sensitivity upon an application of less pressure on the outer plate. Such pressure compresses the sensor between the plates to produce an electrical signal. A controller receiving the signal can, in turn, execute to open a door, call an elevator and/or activate a light or sound to provide feedback.

Systems and methods for in-situ monitoring of gearbox are provided. An example system includes a mounting plate coupled to a component within the gearbox and a transducer array having a plurality of piezoelectric transducers disposed thereon to ultrasonically obtain diagnostic information about one or more components in the gearbox. The plurality of piezoelectric transducers are in contact with a surface of one or more mechanical components within the gearbox. The system includes circuitry, at least a portion of which is mounted inside the gearbox, electrically couplable to the transducer array, the circuitry configured to direct an excitation signal to a selected piezoelectric transducer of the plurality of piezoelectric transducers, and direct a response received from one or more of the plurality of piezoelectric transducers in proximity to the selected piezoelectric transducer toward a processor programmed or configured to determine gearbox diagnostic information therefrom.

A device and a method for determining and/or monitoring at least one process variable of a medium include a sensor unit having a mechanically oscillatable unit, at least a first piezoelectric element, a conductivity/capacitance detecting unit for determining and/or monitoring a conductivity and/or capacitance of the medium and an electronics unit. The device is embodied to excite the mechanically oscillatable unit by means of an excitation signal such that mechanical oscillations are executed, to receive the mechanical oscillations of the oscillatable unit, to convert them into a first received signal, to transmit a transmitted signal, and to receive a second received signal. The electronics unit is embodied, based on the first and/or second received signal, to determine the at least one process variable of the medium.

Provided are a piezoelectric material, a piezoelectric member, a piezoelectric element and a pressure sensor that can be used in high-temperature environments. The piezoelectric material is composed of Sr-substituted akermanite represented by Ca.sub.(2-x)Sr.sub.xMgSi.sub.2O.sub.7 (0.1≤x≤0.6).

According to one embodiment, a flexible substrate includes a line portion including a support plate including a first surface, a flexible insulating base located on the first surface and a wiring layer disposed on the insulating base, a piezoelectric material covering the line portion, a protective member located on the piezoelectric material and an island-shaped first electrode provided on the insulating base.

Illustrative embodiments enable a MEMS transducer to quickly recover from, acoustic overload events by quickly resetting signal processing circuitry downstream from a MEMS transducer. An acoustic overload sensor detects occurrence of an acoustic overload event, and triggers a reset circuit to operate a set of switches to rapidly drain charge from a corresponding set of capacitances within the transducer, or within the signal processing circuitry, thereby resetting the signal processing circuitry more rapidly than would occur if said transducer or circuitry were allowed to recover on its own.

A multi-layer insulation includes a plurality of layers that are laminated on each other. A detection layer that is at least one of the plurality of layers has a piezoelectric film, and a pair of electrode parts installed on both surfaces of the piezoelectric film.

A structure includes an oriented piezoelectric polymer arranged in a circular tubular or circular columnar shape, wherein the orientation angle of the piezoelectric polymer with respect to the central axis of the structure is 15° to 75°, the piezoelectric polymer includes a crystalline polymer having an absolute value of 0.1 to 1000 pC/N for the piezoelectric constant d14 when the orientation axis is the third axis, and the piezoelectric polymer includes a P-body containing a crystalline polymer with a positive piezoelectric constant d14 value and an N-body containing a crystalline polymer with a negative value, wherein for the portion of the central axis of the structure having a length of 1 cm, the value of T1/T2 is 0 to 0.8, T1 being the smaller and T2 being the larger of (ZP+SN) and (SP+ZN), where ZP, SP, ZN, and SN are particularly defined masses.

An ultrasonic transducer of this invention includes a rigid substrate with opening parts extending between bottom and top surfaces, a flexible resin film fixed to the top surface of the substrate to cover the opening parts, and piezoelectric elements fixed to a top surface of the resin film so as to overlap in a plan view with the opening parts, respectively. An arrangement pitch of the piezoelectric elements is preferably set to be equal to or less than 4.3 mm, and the piezoelectric element may have a rectangular shape in the plan view having longitudinal and lateral dimensions in the plan view with a maximum value of 4.0 mm or less, a circular shape in the plan view having a diameter of 4.0 mm or less, or an elliptical shape in the plan view having a major axis of 4.0 mm or less.