An ultrasonic sensor includes a casing and a piezoelectric vibrator element. The casing includes a first unit made of a metal and a second unit made of a resin. The first unit has a cylindrical or substantially cylindrical shape extending in a first direction. The second unit is connected to one end of the first unit in the first direction and includes a cylindrical section and a bottom plate. The cylindrical section extends in the first direction. The bottom plate is a disk-shaped portion which closes an end of the cylindrical section positioned farther away from the first unit in the first direction. The piezoelectric vibrator element is mounted on the bottom plate.

An electromagnetic-piezoelectric composite vibration control device based on a synchronized switch damping technology is provided. An upper guiding component is installed inside the upper rigid frame, a lower guiding component is installed inside a lower rigid component, a guide rod is nested inside the upper guiding component and the lower guiding component, an upper idler wheel mechanism and a lower idler wheel mechanism are fixedly sleeved on the guide rod and are positioned between the upper guiding component and the lower guiding component respectively, an electromagnetic mechanism is fixedly sleeved outside the guide rod, one end of each piezoelectric cantilever beam is fixed between the upper rigid frame and the lower rigid frame, the other end is arranged between the upper idler wheel mechanism and the lower idler wheel mechanism, and the piezoelectric cantilever beams and the electromagnetic mechanism are connected with a circuit system respectively.

Disclosed is a self-powered vibration damper based on piezoelectricity and a control method. The damper comprises a loading platform, an energy collecting mechanism, a curved leaf spring, a vibration control mechanism and a substrate all connected in sequence, the circuit system comprises a rectifier circuit, a DC-DC voltage conversion circuit, an energy storage circuit, a control circuit and a charging battery, a first piezoelectric stack is connected with the input end of the rectifier circuit, the output end of the rectifier circuit is connected with the input end of the DC-DC voltage conversion circuit, the output end of the DC-DC voltage conversion circuit is connected with the input ends of the energy storage circuit and the charging battery, the output end of the energy storage circuit is connected with the input end of the control circuit, the output end of the control circuit is connected with the second piezoelectric stack.

A vibration module is disclosed. The vibration module includes a film, a piezoelectricity device, and a substrate. The film has a first surface. The piezoelectricity device is disposed on the first surface. The substrate is disposed on the first surface by in-mold injection method, which contacts and surrounds the piezoelectricity device.

A sensor device that senses proper acceleration. The sensor device includes a substrate, a spacer layer supported over a first surface of the substrate, at least a first cantilever beam element having a base and a tip, the base attached to the spacer layer, and which is supported over and spaced from the substrate by the spacer layer. The at least first cantilever beam element further including at least a first layer comprised of a piezoelectric material, a pair of electrically conductive layers disposed on opposing surfaces of the first layer, and a mass supported at the tip portion of the at least first cantilever beam element.

A piezoelectric rotary optical mount including a clamp including a first hole to hold a hollow member, wherein a contact between the clamp and the hollow member generates a coefficient of friction; a bias element adjacent to the first hole to apply a force to control rotational movement of the hollow member by adjusting the coefficient of friction; and a piezoelectric element to actuate the bias element to apply the force. The clamp may include a housing body including a first end and a second end, wherein the first hole extends in a first axis through the housing body to accommodate the hollow member; a pair of elongated cutout regions extending from the first hole towards the second end to define the bias element; and a second hole adjacent to at least one of the cutout regions to accommodate the piezoelectric element.

The piezoelectric microphone chip includes a single thin plate, a diaphragm support structure that is provided on one surface of the thin plate and includes an outer edge support portion that supports an outer edge of the thin plate and a separation support portion that separates the thin plate into a plurality of diaphragms in association with the outer edge support portion, a single or a plurality of piezoelectric conversion portions formed by laminating a first electrode, a piezoelectric film, and a second electrode sequentially from a diaphragm side on each of the diaphragms, and a signal detection circuit that detects outputs from the piezoelectric conversion portions provided on the plurality of diaphragms, and a relationship among a thickness t.sub.1 of the outer edge support portion, a thickness t.sub.2 of the separation support portion, and a thickness td of the thin plate 10 is set to 13.3×td<t.sub.2<t.sub.1−20 μm.

A reusable piezoelectric sensor for damage identification includes a piezoelectric ceramic plate and a metal box bonded to the surface of a test piece, where a wire through hole is formed in the center of a top plate of the metal box, and a side wall of the metal box extends vertically upwards to form a striking face for being struck to remove the metal box from the test piece; the piezoelectric ceramic plate arranged in the metal box is closely and fixedly bonded to a bottom plate of the metal box; and wires of the piezoelectric ceramic plate penetrate through the wire through hole to be connected to an external impedance analyzer. The reusable piezoelectric sensor for damage identification is easy to manufacture and convenient to operate and can effectively eliminate the testing error caused by the difference of the piezoelectric ceramic plate.

A bulk-acoustic resonator module includes: a module substrate; a bulk-acoustic resonator connected to the module substrate by a connection terminal and disposed spaced apart from the module substrate; and a sealing portion sealing the bulk-acoustic resonator. The bulk-acoustic resonator includes a resonating portion disposed opposite to an upper surface of the module substrate. A space is disposed between the resonating portion and the upper surface of the module substrate.

A displacement magnification device has a first link portion including a first rigid body and a first plate spring that couples the first rigid body to a supporting portion and a movable portion. A second link portion includes a second rigid body and a second plate spring that couples the second rigid body to the supporting portion and the movable portion. In this structure, the first rigid body and the second rigid body play roles to suppress the bending of the first plate spring and the second plate spring. In addition, a connection portion between the first plate spring and the supporting portion, a connection portion between the second plate spring and the supporting portion, a connection portion between the first plate spring and the movable portion, and a connection portion between the second plate spring and the movable portion play roles of elastic hinges.