A MEMS device having a body with a first and a second surface, a first portion and a second portion. The MEMS device further has a cavity extending in the body from the second surface; a deformable portion between the first surface and the cavity; and a piezoelectric actuator arranged on the first surface, on the deformable portion. The deformable portion has a first region with a first thickness and a second region with a second thickness greater than the first thickness. The second region is adjacent to the first region and to the first portion of the body.

An electric current based on electric charge produced on the piezoelectric body changes by going through a first path, a second path, a third path, and a fourth path in this order. On the first path, the electric current becomes larger as the voltage becomes higher. On the second path, the electric current becomes smaller as the voltage becomes higher. On the third path, the electric current becomes larger as the voltage becomes higher. On the fourth path, the electric current becomes smaller as the voltage becomes higher.

A piezoelectric actuator includes: a vibrating plate including a first surface configured to close an opening provided in a substrate and also including a second surface including a plurality of piezoelectric elements; a suppressing portion configured to suppress vibration of the vibrating plate; and a plurality of walls sticking out into the opening from the first surface, in which, when an active portion of a piezoelectric element is set as a portion where a first electrode, a piezoelectric layer, and a second electrode overlap, the walls are provided between adjacent active portions in plan view from a direction in which the first electrode, the piezoelectric layer, and the second electrode are stacked, and a distance between adjacent walls is longer than a distance between adjacent active portions in a plane perpendicular to the stacking direction.

A vibration apparatus may include a vibration device and an adhesive member at a surface of the vibration device. A modulus of the vibration device may be equal to a modulus of the adhesive member or may be greater than the modulus of the adhesive member.

A microfluidic device for continuous ejection of fluids includes: a semiconductor body that laterally delimits chambers; an intermediate structure which forms membranes each delimiting a top of a corresponding chamber; and a nozzle body which overlies the intermediate structure. The device includes, for each chamber: a corresponding piezoelectric actuator; a supply channel which traverses the intermediate structure and communicates with the chamber; and a nozzle which traverses the nozzle body and communicates with the supply channel. Each actuator is configured to operate i) in a resting condition such that the pressure of a fluid within the corresponding chamber causes the fluid to pass through the supply channel and become ejected from the nozzle as a continuous stream, and ii) in an active condition, where it causes a deformation of the corresponding membrane and a consequent variation of the pressure of the fluid, causing a temporary interruption of the continuous stream.

A piezoelectric element including a piezoelectric layer having a perovskite structure including lead, zirconium, and titanium, and an electrode provided on the piezoelectric layer is provided. In the piezoelectric layer, in a range of 50 nm or smaller from an interface between the piezoelectric layer and the electrode in a thickness direction, a ratio c/a of a lattice spacing a in a direction perpendicular to the thickness direction and a lattice spacing c in the thickness direction satisfies 0.986≤c/a≤1.014.

There is provided a liquid discharge head including a piezoelectric body having a plurality of individual electrodes and a first common electrode, and a plurality of conductor layers. The plurality of individual electrodes have first to fourth individual electrode arrays, and the first common electrode has first and second extending portions, a plurality of first projecting portions, and a plurality of second projecting portions. Each of the first projecting portions overlaps partially with one of the plurality of individual electrodes forming the second individual electrode array along the stacking direction, and each of the second projecting portions overlaps partially with one of the plurality of individual electrodes forming the third individual electrode array along the stacking direction. The plurality of conductor layers are formed between the plurality of first projecting portions and the plurality of second projecting portions, without contacting the first common electrode and without contacting each other.

A MEMS pump includes a first substrate, a first oxide layer, a second substrate, a second oxide layer, a third substrate and a piezoelectric element sequentially stacked to form the entire structure of the MEMS pump. The first substrate has a first thickness and at least one inlet aperture. The first oxide layer has at least one fluid inlet channel and a convergence chamber, wherein the fluid inlet channel communicates with the convergence chamber and the inlet aperture. The second substrate has a second thickness and a through hole, and the through hole is misaligned with the inlet aperture and communicates with the convergence chamber. The second oxide layer has a first chamber with a concave central portion. The third substrate has a third thickness and a plurality of gas flow channels, wherein the gas flow channels are misaligned with the through hole.

A removal module for removing a mis-assembled semiconductor light emitting diode includes a housing having an inner space formed by an upper plate having a nozzle hole and a lower plate spaced apart from the upper plate; a fluid supply part configured to supply a fluid outside the housing to the inner space; and a fluid control part configured to control spray of the fluid supplied to the inner space through the nozzle hole by adjusting a pressure of the inner space.

An ultrasonic device includes: a substrate provided with a first opening and a second opening; a support film that is provided on the substrate and blocks the first opening and the second opening; a transmitting piezoelectric film that is provided on the support film at a position which overlaps the first opening when viewed in a thickness direction of the substrate and is interposed between a pair of electrodes in the thickness direction of the substrate; and a receiving piezoelectric film that is provided on the support film at a position which overlaps the second opening when viewed in the thickness direction of the substrate and is interposed between a pair of electrodes in the thickness direction of the substrate. In the thickness direction of the substrate, a thickness dimension of the transmitting piezoelectric film is smaller than a thickness dimension of the receiving piezoelectric film.