An imaging device includes a two dimensional array of piezoelectric elements. Each piezoelectric element includes: a piezoelectric layer; a bottom electrode disposed on a bottom side of the piezoelectric layer and configured to receive a transmit signal during a transmit mode and develop an electrical charge during a receive mode; and a first top electrode disposed on a top side of the piezoelectric layer; and a first conductor, wherein the first top electrodes of a portion of the piezoelectric elements in a first column of the two dimensional array are electrically coupled to the first conductor.

An imaging device includes a two dimensional array of piezoelectric elements. Each piezoelectric element includes: a piezoelectric layer; a bottom electrode disposed on a bottom side of the piezoelectric layer and configured to receive a transmit signal during a transmit mode and develop an electrical charge during a receive mode; and a first top electrode disposed on a top side of the piezoelectric layer; and a first conductor, wherein the first top electrodes of a portion of the piezoelectric elements in a first column of the two dimensional array are electrically coupled to the first conductor.

A process for producing a piezoelectric sensor includes the following steps: a step of providing a housing made of stainless steel; a step of producing a solution of a compound comprising a metal or metalloid element; a step of depositing a layer of the solution over at least one inner surface of the housing; a step of oxidizing the deposited layer of solution; a step of placing a piezoelectric element inside the housing; a step of closing the housing. A piezoelectric sensor obtained by such a process and comprising a closed steel housing, a piezoelectric element arranged inside the housing and a layer of a solution of a compound comprising a metal or metalloid element that is arranged over at least one inner surface of the housing.

A piezoelectric energy generator for a stadium, auditorium or other venue includes one or more tiles or mats, with each tile having one or more piezoelectric transducer devices formed therein such that voltage and current are generated when pressure is applied to the piezoelectric transducers, such as by people walking or stomping on the tiles. The tiles and piezoelectric devices are interconnected and connected to centrally located control and conditioning circuitry, which conditions the generated electricity for usage, storage, or transmission to an external power grid.

A piezoelectric energy generator for a stadium, auditorium or other venue includes one or more tiles or mats, with each tile having one or more piezoelectric transducer devices formed therein such that voltage and current are generated when pressure is applied to the piezoelectric transducers, such as by people walking or stomping on the tiles. The tiles and piezoelectric devices are interconnected and connected to centrally located control and conditioning circuitry, which conditions the generated electricity for usage, storage, or transmission to an external power grid.

A piezoelectric actuator includes a piezoelectric element having a rectangular shape, a first supporter, and a second supporter. The piezoelectric element includes a pair of main surfaces opposing each other, a first end surface and a second end surface opposing each other in a long side direction of the pair of main surfaces, and a first side surface and a second side surface opposing each other in a short side direction of the pair of main surfaces. The first supporter is provided to be movable according to deformation of the first end surface. The second supporter is provided to be movable according to deformation of the first side surface. The first supporter includes an opposing portion and a protruding portion. The opposing portion opposes the second supporter in the long side direction. The protruding portion protrudes from the opposing portion and abuts on the second supporter.

A piezoelectric actuator includes a piezoelectric element having a rectangular shape, a first supporter, and a second supporter. The piezoelectric element includes a pair of main surfaces opposing each other, a first end surface and a second end surface opposing each other in a long side direction of the pair of main surfaces, and a first side surface and a second side surface opposing each other in a short side direction of the pair of main surfaces. The first supporter is provided to be movable according to deformation of the first end surface. The second supporter is provided to be movable according to deformation of the first side surface. The first supporter includes an opposing portion and a protruding portion. The opposing portion opposes the second supporter in the long side direction. The protruding portion protrudes from the opposing portion and abuts on the second supporter.

Bulk acoustic wave (BAW) resonators and particularly top electrodes with step arrangements for BAW resonators are disclosed. Top electrodes on piezoelectric layers are disclosed that include a border (BO) region with a dual-step arrangement where an inner step and an outer step are formed with increasing heights toward peripheral edges of the top electrode. Dielectric spacer layers may be provided between the outer steps and the piezoelectric layer. Passivation layers are disclosed that extend over the top electrode either to peripheral edges of the piezoelectric layer or that are inset from peripheral edges of the piezoelectric layer. Piezoelectric layers may be arranged with reduced thickness portions in areas that are uncovered by top electrodes. BAW resonators as disclosed herein are provided with high quality factors and suppression of spurious modes while also providing weakened BO modes that are shifted farther away from passbands of such BAW resonators.

An object of the present invention is to provide an electroacoustic transducer and an image display device, each of which can be rolled up and does not need a mechanical mechanism and a driving source. The object is accomplished by providing a vibration plate or display element which can be rolled up, and a convex leaf spring having an arc-shaped cross section in the lateral direction and having a concave side disposed facing one surface of the vibration plate or a non-image-displaying surface of the display element.

A vibration device includes: a piezoelectric unit including a piezoelectric element; a housing that holds the piezoelectric unit; a wiring member electrically connected to the piezoelectric unit; and a joining member that joins the housing to an external device. The housing includes a bottom surface portion to which the piezoelectric unit is fixed, and a side surface portion standing at an edge portion of the bottom surface portion. The side surface portion has a first surface formed on a top portion of the side surface portion, and a second surface that is one step lowered from the first surface by a cutout portion formed in the top portion. The joining member extends along the first surface to bridge over the cutout portion. The wiring member is joined to the joining member at a position of the first surface, and passes through the cutout portion in a state where the wiring member is not joined to the second surface.