A MEMS device is provided that includes a piezoelectric film, a first electrode and a second electrode sandwiching the piezoelectric film, a protective film that covers at least part of the second electrode and having a cavity that opens part of the second electrode, a third electrode that contacts the second electrode at least in the cavity and is provided so as to cover at least part of the protective film, and a first wiring layer having a first contact portion in contact with the third electrode.

A piezoelectric actuator is formed like a rectangular flat plate, and includes a substrate layer, a lower electrode layer, a piezoelectric layer, and an upper electrode layer formed in this order from bottom to top in a thickness direction. The upper electrode layer is constituted of a plurality of electrode segments separated in a surface direction, and connection wires connecting the electrode segments which are adjoining in the surface direction.

There is provided a head including: a piezoelectric layer; a plurality of individual electrodes located below the piezoelectric layer in an up-down direction; a common electrode located below the piezoelectric layer. The plurality of individual electrodes includes: a first individual electrode array including a plurality of first individual electrodes aligned in a first direction; and a second individual electrode array including a plurality of second individual electrodes aligned in the first direction. The common electrode includes: a plurality of first facing portions which are demarcated to correspond to the plurality of first electrodes, respectively; a plurality of second facing portions which are demarcated to correspond to the plurality of second electrodes, respectively; and a connecting portion located between the plurality of first facing portions and the plurality of second facing portions, and connecting the plurality of first facing portions and the plurality of second facing portions.

A mounting structure includes: a first substrate that has a first surface on which a functional element is provided; a wiring portion that is provided at a position, which is different from a position of the functional element on the first surface, and is conductively connected to the functional element; a second substrate that has a second surface that is opposite to the first surface; and a conduction portion that is provided on the second surface, is connected to the wiring portion, and is conductively connected the functional element. The shortest distance between the functional element and the second substrate is longer than the longest distance between the second substrate and a position where the wiring portion is connected to the conduction portion.

An RF integrated circuit device can includes a substrate and a High Electron Mobility Transistor (HEMT) device on the substrate including a ScAlN layer configured to provide a buffer layer of the HEMT device to confine formation of a 2DEG channel region of the HEMT device. An RF piezoelectric resonator device can be on the substrate including the ScAlN layer sandwiched between a top electrode and a bottom electrode of the RF piezoelectric resonator device to provide a piezoelectric resonator for the RF piezoelectric resonator device.

A piezoelectric device includes a first substrate including a first surface on which piezoelectric elements and a common terminal coupled to the piezoelectric elements are placed, a second substrate including a second surface on which a common connecting terminal coupled to a control circuit is placed, a third substrate placed between the first substrate and the second substrate and including a third surface joined to the first surface and a fourth surface facing the second surface, and bonding portions bonding the second substrate and the third substrate by an adhesive, wherein the third substrate includes a first through hole penetrating from the third surface to the fourth surface and a first through electrode provided in the first through hole and coupled to the common terminal, the common connecting terminal is coupled to the first through electrode and electrically coupled to the common terminal via the first through electrode, and the second substrate includes a wall suppressing an outflow of the adhesive on the second surface facing the third substrate.

An electronic device includes a first substrate including a first face on which a common terminal to be coupled to the element is disposed, and a second substrate which has a second face and a third face, and which is arranged so that the second face faces to the first face, wherein the second substrate has a first through hole at a position corresponding to the common terminal, the first through hole penetrating from the second face to the third face, a first through electrode electrically coupled to the common terminal is disposed in the first through hole, and a void is disposed in a part of the first through electrode.

A system for a wireless communication infrastructure using single crystal devices. The wireless system can include a controller coupled to a power source, a signal processing module, and a plurality of transceiver modules. Each of the transceiver modules includes a transmit module configured on a transmit path and a receive module configured on a receive path. The transmit modules each include at least a transmit filter having one or more filter devices, while the receive modules each include at least a receive filter. Each of these filter devices includes a single crystal acoustic resonator device formed with a thin film transfer process with at least a first electrode material, a single crystal material, and a second electrode material. Wireless infrastructures using the present single crystal technology perform better in high power density applications, enable higher out of band rejection (OOBR), and achieve higher linearity as well.

An interventional device includes an elongate shaft and a transducer strip. The transducer strip includes a first edge and an opposing second edge. The first edge and the second edge are separated by a width dimension, and the first edge and the second edge each extend along a length direction of the transducer strip. The transducer strip also includes a piezoelectric transducer that extends along a transducer direction that forms an acute angle with respect to the length direction. The transducer strip is wrapped in the form of a spiral around the elongate shaft of the interventional device such that the piezoelectric transducer forms a band around the elongate shaft. The width dimension is defined such that the adjacent first and second edges of consecutive turns of the spiral abut or overlap one another.

A piezoelectric actuator 10 includes: a piezoelectric element 11; an external electrode 12 covering partially a first surface 11a of the piezoelectric element 11 in a first direction; a wiring member 14; and a conductive joining member 20 joining the wiring member 14 to the external electrode 12, wherein the conductive joining member 20 has an air gap 70 formed between the external electrode 12 and the wiring member 14 in a region overlapping with the wiring member 14 as viewed in the first direction, and wherein the conductive joining member 20 extends to an edge 21 of the external electrode 12 or extends to the first surface 11a of the piezoelectric element 11 beyond the edge 21 of the external electrode 12.