Abstract: A bulk acoustic wave resonator includes a substrate, a first electrode, wherein a cavity is formed between the substrate and the first electrode, a piezoelectric layer disposed on the first electrode and overlapping at least a portion of the first electrode, a second electrode disposed on the piezoelectric layer and overlapping at least a portion of the piezoelectric layer, a passivation layer having at least a portion disposed on the second electrode and overlapping at least a portion of the second electrode, and a lower frame spaced apart from the substrate and having a portion of the cavity disposed therebetween. Any one of the second electrode and the passivation layer includes a protruding portion having a first thickness and an extended portion having a second thickness less than the first thickness, and an inner end of the lower frame and an end of the protruding portion are spaced apart horizontally.

Abstract: Techniques for improving Bulk Acoustic Wave (BAW) resonator structures are disclosed, including filters, oscillators and systems that may include such devices. First and second layers of piezoelectric material may be acoustically coupled with one another to have a piezoelectrically excitable resonance mode. The first layer of piezoelectric material may have a first piezoelectric axis orientation, and the second layer of piezoelectric material may have a second piezoelectric axis orientation that substantially opposes the first piezoelectric axis orientation of the first layer of piezoelectric material. An acoustic reflector electrode may include a first pair of top metal electrode layers electrically and acoustically coupled with the first and second layer of piezoelectric material to excite the piezoelectrically excitable resonance mode at a resonant frequency of the BAW resonator. The acoustic reflector may include a patterned layer.

Abstract: An elastic wave device includes a supporting substrate, a high-acoustic-velocity film stacked on the supporting substrate and in which an acoustic velocity of a bulk wave propagating therein is higher than an acoustic velocity of an elastic wave propagating in a piezoelectric film, a low-acoustic-velocity film stacked on the high-acoustic-velocity film and in which an acoustic velocity of a bulk wave propagating therein is lower than an acoustic velocity of a bulk wave propagating in the piezoelectric film, the piezoelectric film is stacked on the low-acoustic-velocity film, and an IDT electrode stacked on a surface of the piezoelectric film.

Abstract: Techniques for improving Bulk Acoustic Wave (BAW) resonator structures are disclosed, including fluidic systems, oscillators and systems that may include such devices. A bulk acoustic wave (BAW) resonator may comprise a substrate and a first layer of piezoelectric material. The bulk acoustic wave (BAW) resonator may comprise a top electrode. A sensing region may be acoustically coupled with the top electrode of the bulk acoustic wave (BAW) resonator.

Abstract: Provided is an ultrasonic device including a substrate and a vibration plate provided on the substrate and having one or more vibrators configured to generate an ultrasonic wave by vibration. The vibration plate has a movable portion provided with the vibrator and configured to vibrate accompanying with the vibration of the vibrator, and a fixed portion fixed to the substrate. A vibration frequency of a reflected wave based on a wave transmitted from the movable portion and received by the movable portion is outside a vibration frequency band region of the vibrator.

Abstract: Disclosed is systems and methods for cleaning devices holding fluid such as heat exchanges. The cleaning is performed by using a system such as a transducer assembly including a mechanical wave generator and a waveguide including a cavity. The system is capable of operating at its fundamental resonance frequency even when connected to an outer surface of the device to be cleaned.

Abstract: A microelectromechanical resonator device has: a main body, with a first surface and a second surface, opposite to one another along a vertical axis, and made of a first layer and a second layer, arranged on the first layer; a cap, having a respective first surface and a respective second surface, opposite to one another along the vertical axis, and coupled to the main body by bonding elements; and a piezoelectric resonator structure formed by: a mobile element, constituted by a resonator portion of the first layer, suspended in cantilever fashion with respect to an internal cavity provided in the second layer and moreover, on the opposite side, with respect to a housing cavity provided in the cap; a region of piezoelectric material, arranged on the mobile element on the first surface of the main body; and a top electrode, arranged on the region of piezoelectric material, the mobile element constituting a bottom electrode of the piezoelectric resonator structure.

Abstract: The present disclosure provides a film bulk acoustic resonator and its fabrication method. The film bulk acoustic resonator includes a first substrate, a first support layer containing a first cavity, a piezoelectric stacked layer, and a first separation structure and/or a second separation structure. The piezoelectric stacked layer includes an effective working region and a parasitic working region; and in the parasitic working region, a first electrode and a second electrode have a corresponding region along a thickness direction. The first separation structure separates the first electrode, and the first electrode of a portion of the parasitic working region is insulated from the first electrode of the effective working region; and the second separation structure separates the second electrode, and the second electrode of a portion of the parasitic working region is insulated from the second electrode of the effective working region.

Abstract: A bulk-acoustic wave resonator includes a resonator including a central portion in which a first electrode, a piezoelectric layer, and a second electrode are sequentially stacked on a substrate, and an extension portion disposed along a periphery of the central portion; and an insertion layer disposed between the piezoelectric layer and the substrate in the extension portion to raise the piezoelectric layer. The insertion layer includes a first insertion layer having a first inclined surface formed along a side surface facing the central portion and a second inclined surface disposed between the first insertion layer and the piezoelectric layer and having a second inclined surface spaced apart from the first inclined surface with respect to a surface direction of the first electrode. The first insertion layer is thinner than the second insertion layer.

Abstract: A transducer includes a supporting body and a suspended structure mechanically coupled to the supporting body. The suspended structure has a first and a second surface opposite to one another along an axis, and is configured to oscillate in an oscillation direction having at least one component parallel to the axis. A first piezoelectric transducer is disposed on the first surface of the suspended structure, and a second piezoelectric transducer is disposed on the second surface of the suspended structure.

Abstract: Interaction of acoustic waves in a piezoelectric-semiconductor resonant cavity with the charge carriers in the semiconductor layer can be directed toward amplification of the acoustic waves; such amplification scheme can be applied in building unilateral amplifiers, zero loss filters, oscillators, high detection range circuit-less wireless sensors, isolators, duplexers, circulators and other acoustic devices. An apparatus for acoustoelectric amplification is described. The apparatus includes a semiconductor layer and a thin piezoelectric layer bonded (or deposited) onto the semiconductor layer forming an acoustic cavity. Two or more tethers forming a current conduction path through the semiconductor layer and two or more access pads to silicon are positioned on two ends of the acoustic cavity and configured to inject a DC current in the semiconductor layer.

Abstract: The disclosure provides a resonator and a filter. The resonator includes: a substrate; and a multilayer structure formed on the substrate. The multilayer structure successively includes a lower electrode layer, a piezoelectric layer and an upper electrode layer from bottom to top. A cavity is formed between the substrate and the multilayer structure, and the cavity includes a lower half cavity below an upper surface of the substrate and an upper half cavity beyond the upper surface of the substrate and protruding toward the multilayer structure. A resonator with novel structure and good performance is formed by providing the cavity with the lower half cavity below the upper surface of the substrate and the upper half cavity above the upper surface of the substrate.

Abstract: A MEMS optical device having an optically active portion and an actuation portion adjacent to each other. The MEMS optical device includes a body, a piezoelectric actuator, and a cap. The body is formed by a substrate, housing a cavity containing a fluid and by a deformable region fixed to the substrate, suspended over the cavity and forming a membrane. The piezoelectric actuator extends on the deformable region at the actuation portion and is protected by the cap, which is coupled to the body at the actuation portion and defines a chamber that houses the piezoelectric actuator.

Abstract: An ultrasonic device includes an ultrasonic sensor, a wiring member, and a housing, in which the wiring member has a covered wire that covers a signal line coupled to the ultrasonic sensor via an insulating layer, and a conductive member that is electrically coupled with the covered wire, the housing has a plurality of housing components having conductivity, and covers the ultrasonic sensor with the plurality of housing components, and the conductive member is electrically coupled to and held by the plurality of housing components.

Abstract: An elastic wave device includes a support substrate, a piezoelectric layer disposed on the support substrate, and an IDT electrode disposed on a piezoelectric layer and including first and second electrode fingers that are interdigitated. A region where the first and second electrode fingers overlap each other as seen in a direction of propagation of elastic waves is an excitation region. Edge portions where an acoustic velocity is lower than an acoustic velocity in a central portion are disposed on opposite sides of a central portion in the excitation region. A first busbar and second busbar include inner busbar portions, central busbar portions, and outer busbar portions. First and second offset electrode fingers extend from the inner busbar portions toward the leading ends of the second electrode fingers or first electrode fingers.

Abstract: A piezoelectric generator structure disposed between an upper platform and a lower platform that includes a lower piezoelectric pad, an upper piezoelectric pad, and a connecting shaft. The lower piezoelectric pad coupled to the upper piezoelectric pad via the connecting shaft, where the lower piezoelectric pad is configured to compress under a downward motion of the upper platform during a compression movement due to an additional load being applied to an existing load on a top surface of the upper platform, where the lower piezoelectric pad produces a first voltage due to the compression movement. The upper piezoelectric pad configured to compress under an upward motion of the upper platform during a rebound movement of the upper platform, where the upper piezoelectric pad produces a second voltage due to the rebound movement. The generator structure configured to provide the first and the second voltage to a coupled power storage unit.

Abstract: A brushless electric motor is disclosed. A group of permanent magnets are physically attached to a group of piezoelectric actuators which push them toward or pull them away from a second group of permanent magnets when the piezoelectric actuators are electrically activated. The second group of permanent magnets may also be pushed and pulled with a second group of piezoelectric actuators. Alternate configurations using electromagnets are also disclosed. A novel configuration for the groups of electromagnets which maximizes efficiency in a piezoelectrically actuated motor is also disclosed.

Abstract: A piezoelectric element includes a first electrode layer, a piezoelectric layer, and a second electrode layer. The first electrode layer, the piezoelectric layer, and the second electrode layer are stacked in sequence on one another. The first electrode layer has a first part overlapping the piezoelectric layer in a plan view, and a second part at least partially separated from the first part and not overlapping the piezoelectric layer in the plan view. The second electrode layer has a third part overlapping the piezoelectric layer in the plan view, and a fourth part separated from the third part. The fourth part is in contact with the first part and the second part.

Abstract: Methods for improving the electromechanical coupling coefficient and bandwidth of micromachined ultrasonic transducers, or MUTs, are presented as well as methods of manufacture of the MUTs improved by the presented methods.

Abstract: A digitally tunable acoustic wave resonator includes, in part, a first electrode positioned above a substrate, a composite stack positioned above the first electrode, and a second electrode positioned above the composite stack. The composite stack may include one or more alternate layers of a ferroelectric layer and a transition-metal nitride layer. The transition-metal nitride layer can be positioned above the ferroelectric layer, except the ferroelectric layer at the top of the composite stack. The ferroelectric layer comprises an aluminum scandium nitride layer Al1-xScxN, where 0<x<1.