A vibration device that includes a first elastic plate having a first end portion and a second end portion, and a first surface and a second surface facing each other and connecting the first and second end portions. A second elastic plate is laminated to the second end portion of the first elastic plate, and a piezoelectric vibration element is provided on at least one of the first surface and the second surface of the first elastic plate. On a portion where the first elastic plate and the second elastic plate are laminated, a first bonding portion and a second bonding portion that bond the first elastic plate and the second elastic plate to each other are provided. The second bonding portion is located closer to the first end portion than the first bonding portion.

A vibration device comprises a vibrating member having at least n (n2) piezoelectric elements arranged on a vibrating plate, each of the piezoelectric elements being formed by using a lead-free piezoelectric material and electrodes, wherein if the temperature that maximizes the piezoelectric constant of the piezoelectric material of each of the n piezoelectric elements is expressed as T.sub.m (m being a natural number between 1 and n), at least two of T.sub.1 through T.sub.n differ from each other.

A piezoelectric element which includes a vibrating film, a piezoelectric body disposed on one surface of the vibrating film, and a horizontal electrode structure in which electrodes are disposed at a predetermined gap therebetween on the piezoelectric body. The vibrating film includes a recess portion in a portion corresponding to the predetermined gap in plan view.

A piezoelectric drive device includes piezoelectric vibration modules that each include a vibration portion and a transmission unit abutting a driven portion and transmitting longitudinal vibration in an alignment direction of the vibration portion with the driven portion and bending vibration which is a composite of the longitudinal vibration and lateral vibration of the vibration portion intersecting the alignment direction to the driven portion and a controller controlling the modules. The controller controls the modules in a first drive mode wherein the transmission portions of all the modules are driven to perform the bending vibration in a first direction and a second drive mode wherein the transmission portions of some of the modules are driven to perform the bending vibration in the first direction and the transmission portions of other modules are driven to perform the longitudinal or bending vibrations in a second direction opposite the first direction.

An apparatus for producing haptic feedback and an electronic device are disclosed. In an embodiment an apparatus includes a piezoelectric actuator and a mechanical structure, wherein the piezoelectric actuator is configured to modify its extension in a first direction, and wherein the mechanical structure is configured to deform as a result of a change in the extension of the piezoelectric actuator in such a way that an area of the mechanical structure is moved in relation to the piezoelectric actuator in a second direction which is perpendicular to the first direction.

A vibration device includes a piezoelectric element, a vibration member to which the piezoelectric element is bonded, and a wiring member connected with the piezoelectric element. A method for vibrating the vibration device includes inputting a signal including a fundamental frequency component to the piezoelectric element through the wiring member, and vibrating the vibration device in a vibration mode that includes the fundamental frequency component and does not approximately include a high order frequency component that is n times (n represents an integer of 2 or more) the fundamental frequency component. The fundamental frequency component is lower than the resonance frequency component of the vibration device.

Systems and method are provided for evaluating a biomechanical property of tissue. A shear wave generator induces a shear wave in the tissue. An optical imaging system captures video in the visible light spectrum comprising a series of image frames of the tissue during the shear wave. An image processing component determines, at each of a plurality of locations, a speed at which the shear wave travels within the tissue from the series of image frames. A parameter calculation component calculates a value for the biomechanical property from the determined speed of the shear wave at a plural subset of the plurality of locations.

A piezoelectric micromachined ultrasound transducer (PMUT) is disclosed. The device consists of a flexible membrane that is connected to a rigid substrate via flexures. The flexures are defined by slots etched through the perimeter of the membrane. These features release the stress present on the structural layers of the membrane, making it less sensitive to residual stress. The flexures are designed to act as torsion springs so that the membrane's vibration mode shape is highly curved in the piezoelectric actuation area, thereby increasing the electromechanical coupling.

Systems and techniques are provided for an ultrasonic transducer. A substrate may include a main cavity, a secondary cavity, and a channel. The main cavity may have a greater depth than the secondary cavity. The secondary cavity may have a greater depth than channel. A first step may be formed where the main cavity and the secondary cavity overlap. A second step may be formed where the secondary cavity and the main cavity overlap. An electromechanically active device may be attached to the substrate at the first step and the second step such that a free end of the electromechanically active device is suspended over the main cavity. A membrane section may be bonded to the substrate such that the membrane covers the main cavity and the secondary cavity and is bonded to the free end of the electromechanically active.

A cooling system including a heat load; a supply line supplying a cold coolant to the heat load, wherein the cold coolant receives heat from the heat load and becomes a hot coolant, a return line receiving the hot coolant from the heat load, a transducer generating elliptical ultrasonic waves, and a horn coupled to the receiving line and receiving the hot coolant, wherein the horn conveys the elliptical ultrasonic waves to the hot coolant. The hot coolant, in response to the horn conveying the elliptical ultrasonic waves, undergoes heat loss through convection. Elliptical ultrasonic waves are provided by a transducer combining a longitudinal actuator and a bending actuator.