A piezoelectric device that includes a base member having an opening therein and an upper layer supported by the base member. The upper layer includes a vibration portion at a location corresponding to the opening in the base member. The vibration portion includes a lower electrode, an intermediate electrode and an upper electrode that are spaced apart from one another in a thickness direction of the piezoelectric device. The upper layer includes a first piezoelectric layer disposed so as to be at least partially sandwiched between the lower electrode and the intermediate electrode, and a second piezoelectric layer disposed so as to overlap with the first piezoelectric layer and so as to be at least partially sandwiched between the intermediate electrode and the upper electrode. The first piezoelectric layer and the second piezoelectric layer are different in relative permittivity in the thickness direction of the piezoelectric device.

A piezoelectric micromachined ultrasonic transducer (pMUT) device may include a piezoelectric membrane transducer designed to have lower sensitivity to residual stress and reduced sensitivity to geometric variations arising from the backside etching process used to release the membrane. These designs allow some of its key feature to be adjusted to achieve desired characteristics, such as pressure sensitivity, natural frequency, stress sensitivity, and bandwidth.

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.

A device with a membrane comprising a support, a membrane made of a polymer material suspended on said support and at least one actuating module arranged opposite a face of the membrane and separate from said membrane, said actuating module comprising at least one actuator comprising at least one piezoelectric material and a beam connected to the support and separate from the membrane, the piezoelectric material being connected to the beam, such that, when a difference in electric potential is applied to the piezoelectric material, a bimetal effect appears between the piezoelectric material and the beam deforming the beam in the direction of the membrane, causing the deformation of the membrane, said device also comprising at least one electrostatic actuator configured for compressing at least one part of the membrane on the at least one part of the actuating module.

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.

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.

A micropump device is formed in a monolithic semiconductor body integrating a plurality of actuator elements arranged side-by-side. Each actuator element has a first chamber extending at a distance from a first face of the monolithic body; a membrane arranged between the first face and the first chamber; a piezoelectric element extending on the first face over the membrane; a second chamber, arranged between the first chamber and a second face of the monolithic body; a fluidic inlet path fluidically connecting the second chamber with the outside of the monolithic body; and a fluid outlet opening extending in a transverse direction in the monolithic body from the second face as far as the second chamber, through the first chamber. The monolithic formation of the actuator elements and the possibility of driving the actuator elements at different voltages enable precise adjustment of flows, from very low values to high values.

An ultrasound sensor includes: a diaphragm; a plurality of first electrodes; a plurality of second electrodes; and a plurality of piezoelectric layers which is provided between the first electrode and the second electrode, in which, in a Z-direction, a portion in which the first electrode, the piezoelectric layer and the second electrode are overlapped is referred to as an active portion, and a range to the extent that the diaphragm is oscillatable by driving the active portion is referred to as a movable portion, when a unit including one movable portion and the active portion which is provided within the one movable portion is referred to as one ultrasound element in plan view, two or more types of ultrasound elements in which a dimension of the active portion with respect to a dimension of the movable portion is different from each other in plan view are provided.

A piezoelectric vibration device that includes a piezoelectric vibrator having excitation electrodes formed thereon; a base having the piezoelectric vibrator on a first surface thereof; outer electrodes formed to continuously extend from the first surface of the base through a side face of the base to a second surface of the base opposite the first surface; and a lid having a recess opening that faces the first surface of the base, the lid being joined to the base to hermetically seal the piezoelectric vibrator in an internal space defined by the recess and the base. An edge portion of a corresponding one of the outer electrodes, formed by the first surface and the side face of the base, is at least partly covered by a covering member having insulating properties.

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.