A transducer includes: a film support portion having a hollow portion; a vibration film displaceable in a film thickness direction; a piezoelectric element, the piezoelectric element including a pair of electrodes and a piezoelectric film; and in regions overlapping the hollow portion, a plurality of first regions having a first total film thickness which is a sum of a film thickness of the vibration film and a film thickness of the piezoelectric element, and a plurality of second regions having a second total film thickness which is a sum of a film thickness of the vibration film and a film thickness of the piezoelectric element, the second total film thickness being different from the first total film thickness. The first regions and the second regions are alternately arranged, and one of the first regions is adjacent to a connection portion between the film support portion and the vibration film.

A piezoelectric element that includes a substrate, a lower electrode layer on the substrate, an intermediate layer on the lower electrode layer, and an upper electrode layer on the intermediate layer. The intermediate layer includes a first piezoelectric layer including an aluminum nitride as a main component thereof and located between the lower electrode layer and the upper electrode layer, a first buffer layer including an aluminum nitride as a main component and located between the first piezoelectric layer and the upper electrode layer, a first intermediate electrode layer located between the first buffer layer and the upper electrode layer, and a second piezoelectric layer located between the first intermediate electrode layer and the upper electrode layer.

A piezoelectric device includes a piezoelectric body at least a portion of which can bend and vibrate, an upper electrode on an upper surface of the piezoelectric body and in which distortion of a crystal lattice is reduced as a distance from the upper surface of the piezoelectric body increases, a lower electrode on a lower surface of the piezoelectric body and in which distortion of a crystal lattice is reduced as a distance from the upper surface of the piezoelectric body increases, and a support substrate below the piezoelectric body, in which a recess extending from a lower surface of the support substrate toward the lower surface of the piezoelectric device is provided.

A piezoelectric actuator assembly is described. The assembly including a first layer including a top and a bottom surfaces. The assembly including a second layer having a top and a bottom surfaces, the bottom surface of the second layer is disposed over the top surface of the first layer. The assembly including a third layer having a top and a bottom surfaces, the bottom surface of the third layer is disposed over the top surface of the second layer. The assembly includes a first electrode, a second electrode, a third electrode, and a fourth electrode. The third electrode is configured to be shorter than the second electrode such that the active PZT length of the second layer and the third layer is shorter than the active PZT length of the first layer.

A display apparatus, display device and control method thereof, and non-transient computer-readable storage medium are provided. The display apparatus includes a display substrate and an ultrasonic transducer. The ultrasonic transducer includes a receiving electrode layer, which is disposed between two opposite bottom surfaces of the display substrate, and other parts of the ultrasonic transducer are disposed outside the display substrate. The display substrate includes a first pixel circuit and a first light emitting device, and the first light emitting device and the receiving electrode layer are respectively connected with the corresponding output terminals of the first pixel circuit.

Provided is a lead-free piezoelectric material reduced in dielectric loss tangent, and achieving both a large piezoelectric constant and a large mechanical quality factor. A piezoelectric material according to at least one embodiment of the present disclosure is a piezoelectric material including a main component formed of a perovskite-type metal oxide represented by the general formula (1): Na.sub.x+s(1−y)(Bi.sub.wBa.sub.1−s−w).sub.1−yNb.sub.yTi.sub.1−yO.sub.3 (where 0.84≤x≤0.92, 0.84≤y≤0.92, 0.002≤(w+s)(1−y)≤0.035, and 0.9≤w/s≤1.1), and a Mn component, wherein the content of the Mn is 0.01 mol % or more and 1.00 mol % or less with respect to the perovskite-type metal oxide.

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 piezoelectric device including a flow path forming substrate in which pressure chambers are formed, a diaphragm, and piezoelectric actuators. Active portions, each having a piezoelectric layer interposed between a first electrode and a second electrode, are each, in plan view, provided from an edge portion opposing the pressure chamber to a portion outside the pressure chamber, and a ratio of a film thickness of the piezoelectric layer to a film thickness of the diaphragm is 4.7 or less.

There is provided a liquid discharge head, including: a channel unit; a vibration film; and piezoelectric elements. Pressure chambers form pressure chamber pairs arranged in a second direction. Each of the pressure chamber pairs includes a first pressure chamber and a second pressure chamber that communicate with an identical nozzle via a communication channel Rigidity of a first partition wall separating the first pressure chamber from the second pressure chamber, the first and second pressure chambers being included in each of the pressure chamber pairs, is different from rigidity of a second partition wall separating the first pressure chamber from the second pressure chamber, the first and second pressure chambers being adjacent to each other in the second direction and included in different pressure chamber pairs included in the pressure chamber pairs.