A piezoelectric transducer includes a semiconductor body with a bottom electrode of conductive material. A piezoelectric element is on the bottom electrode. A first protective layer, on the bottom electrode and the piezoelectric element, has a first opening through which a portion of the piezoelectric element is exposed, and a second opening through which a portion of the bottom electrode is exposed. A conductive layer on the first protective layer and within the first and second openings is patterned to form a top electrode in electrical contact with the piezoelectric element at the first opening, a first biasing stripe in electrical contact with the top electrode, and a second biasing stripe in electrical contact with the bottom electrode at the second opening.

A method and structure for a transfer process for an acoustic resonator device. In an example, a bulk acoustic wave resonator (BAWR) with an air reflection cavity is formed. A piezoelectric thin film is grown on a crystalline substrate. Patterned electrodes are deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the electrodes and a planarized support layer is deposited over the sacrificial layer. The device can include temperature compensation layers (TCL) that improve the device TCF. These layers can be thin layers of oxide type materials and can be configured between the top electrode and the piezoelectric layer, between the bottom electrode and the piezoelectric layer, between two or more piezoelectric layers, and any combination thereof. In an example, the TCLs can be configured from thick passivation layers overlying the top electrode and/or underlying the bottom electrode.

A piezoelectric transducer includes a transducer unit disposed within a watertight and gas-tight housing and having at least one piezoelectric element contacted by at least two electrodes. A signal lead-through is electrically connected to the electrodes and configured conducting polarization charges as signals from the piezoelectric element through the housing to an environment outside of the housing. A signal cable arranged outside of the housing includes at least two signal conductors. The signal lead-through includes a support element having at least two conducting paths in electrical contact with one of the signal conductors.

A wafer scale ultrasonic sensor assembly includes a wafer substrate, an ultrasonic element, first and second protective layers, conductive wires, a transmitting material, an ASIC, a conductive bump, and a soldering portion. The wafer substrate includes a via. The ultrasonic element is exposed to the via. The conductive wires are on the first protective layer and connected to the ultrasonic element. The second protective layer covers the conductive wires, and the second protective layer has an opening corresponding to the ultrasonic element. The transmitting material contacts the ultrasonic element. The ASIC is connected to the wafer substrate, so that the via forms a space between the ASIC and the ultrasonic element. The conductive pillar is in a via defined through the ASIC, the wafer substrate, and the first protective layer, and the conducive pillar is respectively connected to the conductive wires and the soldering portion.

A method and structure for a transfer process for an acoustic resonator device. In an example, a bulk acoustic wave resonator (BAWR) with an air reflection cavity is formed. A piezoelectric thin film is grown on a crystalline substrate. One or more patterned electrodes are deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the one or more electrodes and a planarized support layer is deposited over the sacrificial layer. The support layer is etched to form one or more cavities overlying the electrodes to expose the sacrificial layer. The sacrificial layer is etched to release the cavities around the electrodes. Then, a cap layer is fusion bonded to the support layer to enclose the electrodes in the support layer cavities.

A piezoelectric device that includes a sintered body in which a first conductor portion and a second conductor portion are disposed on both principal surfaces of a piezoelectric ceramic base body. The first conductor portion includes conductive films having a predetermined pattern. An insulating film is formed on the principal surface of the piezoelectric ceramic base body on which the conductive films are disposed such that portions of the conductive films are exposed therethrough. The insulating film has a malleability equal to or greater than that of the conductive films.

Digital valve controllers and seal washer assemblies for use with digital valve controllers include a seal washer assembly. The seal washer assembly includes a body. The body has a bore. The seal washer assembly includes a flange. The flange is coupled to the body and includes a passage, a face-seal groove, and an exterior-seal groove. The seal washer assembly includes a face seal. The face seal is disposed within the face-seal groove. The seal washer assembly includes an exterior seal. The exterior seal is disposed within the exterior-seal groove.

A surface acoustic wave module (SAW module) includes a piezoelectric element substrate including a piezoelectric body, an IDT disposed on a front surface of the piezoelectric element substrate and including a comb-like electrode pair, and a coating layer covering the piezoelectric element substrate and the IDT. The coating layer is disposed on the front surface of the piezoelectric element substrate, an end surface of the piezoelectric element substrate, and a corner portion between the front surface of the piezoelectric element substrate and the end surface of the piezoelectric element substrate.

An acoustic transducer includes a first flexible structure having a top surface and a bottom surface. A transducer is attached to the top surface of the first flexible structure, wherein the transducer causes deformation of the first flexible structure when an input electrical signal is applied to the transducer. A second flexible structure has a convex top surface and a concave bottom surface. The convex top surface of the second flexible structure is in contact with the bottom surface of the first flexible structure. Deformation of the first flexible structure causes deformation of the second flexible structure.

Methods of using and making chemical sensors include exposing a functionalized electrode to a substance to be tested. The functionalized electrode is electrically connected to a sensor having a piezoelectric element and a piezoresistive element. A voltage on the functionalized electrode controls a resistance of the piezoresistive element. A current is measured passing through the piezoresistive element. The presence of the analyte is determined based on the measured current.