A piezoelectric actuator includes a substrate, a first electrode arranged on the substrate, a piezoelectric body stacked on the first electrode, a second electrode superimposed on a surface of the piezoelectric body on a side opposite to the first electrode, and a wiring connected to the first electrode. The first electrode has a connecting portion which is arranged to protrude from an end portion of the piezoelectric body and to which the wiring is connected, and a first conductive portion is provided so that the first conductive portion overlaps with the first electrode while extending over from an area overlapped with the end portion of the piezoelectric body up to the connecting portion of the first electrode.

Provided is a method of manufacturing an ultrasound probe. The method includes: preparing a backing layer having first and second surfaces with different heights due to forming a groove in the backing layer, wherein first and second electrodes are exposed on the first and second surfaces, respectively; forming a third electrode that is in contact with the first electrode; forming a base piezoelectric unit on the third electrode, the base piezoelectric unit including a piezoelectric layer; forming a piezoelectric unit by removing an upper region of the base piezoelectric unit; and forming a fourth electrode on the backing layer and the piezoelectric unit.

A printed circuit board includes: insulating layers and wiring layers arranged in stacked configuration; a cavity disposed in a first insulating layer among the insulating layers; a piezoelectric substrate disposed in the cavity; an electrode disposed on the piezoelectric substrate and configured to convert an electrical signal into an elastic wave or to convert an elastic wave into an electrical signal; and a sealing part disposed on the piezoelectric substrate, the sealing part enclosing the electrode and forming an air gap around the electrode.

Frequency bandwidth of a cantilever beam system can be enhanced using a movable mass having motion in a cavity of a mass attached to cantilever beam, where the motion is transverse to the cantilever beam. In various embodiments, a cantilever beam apparatus includes a cantilever beam, a first mass, and a second mass. The first mass can be attached to the cantilever beam, with the first mass having a cavity arranged transverse to the cantilever beam. The second mass can be disposed in the cavity such that the second mass is movable in the cavity in a direction transverse to the cantilever beam. Apparatus, systems, and methods associated with enhanced frequency bandwidth of cantilever beam using transverse movable mass are applicable in a variety of applications.

Frequency bandwidth of a cantilever beam system can be enhanced using a movable mass having motion in a cavity of a mass attached to cantilever beam, where the motion is transverse to the cantilever beam. In various embodiments, a cantilever beam apparatus includes a cantilever beam, a first mass, and a second mass. The first mass can be attached to the cantilever beam, with the first mass having a cavity arranged transverse to the cantilever beam. The second mass can be disposed in the cavity such that the second mass is movable in the cavity in a direction transverse to the cantilever beam. Apparatus, systems, and methods associated with enhanced frequency bandwidth of cantilever beam using transverse movable mass are applicable in a variety of applications.

An acoustic resonator device is formed using sacrificial polysilicon pillar by forming a polysilicon pillar on a substrate and depositing a dielectric layer to bury the polysilicon pillar and planarizing the surface of the dielectric layer. A piezoelectric plate is bonded to the planarized surface of the dielectric layer and thinned to a target piezoelectric membrane thickness. At least one conductor pattern is formed on the thinned piezoelectric plate and the polysilicon pillar is then removed using an etchant introduced through holes in the piezoelectric plate to form an air cavity where the pillar was removed.

An acoustic resonator device is formed using sacrificial polysilicon pillar by forming a polysilicon pillar on a substrate and depositing a dielectric layer to bury the polysilicon pillar and planarizing the surface of the dielectric layer. A piezoelectric plate is bonded to the planarized surface of the dielectric layer and thinned to a target piezoelectric membrane thickness. At least one conductor pattern is formed on the thinned piezoelectric plate and the polysilicon pillar is then removed using an etchant introduced through holes in the piezoelectric plate to form an air cavity where the pillar was removed.

An acoustic wave resonator includes a resonating part disposed on and spaced apart from a substrate by a cavity, the resonating part including a membrane layer, a first electrode, a piezoelectric layer, and a second electrode that are sequentially stacked. 0 Mg170 may be satisfied, Mg being a difference between a maximum thickness and a minimum thickness of the membrane layer disposed in the cavity.

The present disclosure provides a method of fabricating an ultrasound transducer. A substrate having a first side and a second side opposite the first side is provided. A bottom electrode is formed over the first side of the substrate. A piezoelectric element is formed over the bottom electrode. The piezoelectric element has a chamfered sidewall. A top electrode is formed over the piezoelectric element. A step metal element is formed over a portion of the top electrode proximate to the chamfered sidewall of the piezoelectric element.

A rectangular quartz crystal blank having long sides substantially parallel to a Z axis of the quartz crystal blank, and short sides substantially parallel to an X axis of the quartz crystal blank. The quartz crystal blank includes a first center region, a second region and a third region that are adjacent to the first region along a long-side direction, and a fourth region and a fifth region that are adjacent to the first region along a short-side direction. A thickness of the second region and a thickness of the third region are smaller than the thickness of the first region, and/or a thickness of the fourth region and a thickness of the fifth region are smaller than the thickness of the first region, and 16.18W/T16.97, where W is a length of a short side and T is a thickness.