Described are transducer assemblies and imaging devices comprising: a microelectromechanical systems (MEMS) die including a plurality of piezoelectric elements; a complementary metal-oxide-semiconductor (CMOS) die electrically coupled to the MEMS die by a first plurality of bumps and including at least one circuit for controlling the plurality of piezoelectric elements; and a package secured to the CMOS die by an adhesive layer and electrically connected to the CMOS die.

A piezoelectric device includes a substrate, a piezoelectric element, and a lid. The piezoelectric element includes a base portion and a membrane portion. The base portion is on a first main surface and has an annular outer shape when viewed from a normal direction of the first main surface. The membrane portion is at an inner side portion of the base portion when viewed from the normal direction. The lid is on the first main surface, covers the piezoelectric element, and is spaced apart from the piezoelectric element on the first main surface side. In the substrate, a first through hole extending from the first main surface to a second main surface is facing the membrane portion. The membrane portion includes a through slit.

A piezoelectric device includes a substrate including a first main surface and a second main surface. A piezoelectric element is on the first main surface. A cover on the first main surface. The cover covers the piezoelectric element and is spaced apart from piezoelectric element on the first main surface side. The piezoelectric element includes a base portion and a membrane portion. The base portion is on the first main surface and has an annular external shape when viewed from the first main surface side. The membrane portion is inside the annular base portion when viewed from the first main surface side. The cover includes a first through hole. The substrate includes a second through hole facing the membrane portion and extends between the first main surface and the second main surface.

A vibrating device includes a diaphragm that includes first and second vibrating portions and a fixation portion, first and second piezoelectric vibrators that are provided at the first and second vibrating portions, respectively, and fixation electrodes. The fixation portion includes a first side portion and a second side portion that extend in different directions. The diaphragm and the fixation electrodes are provided integrally as a single monolithic member. The first vibrating portion extends from the first side portion and the fixation electrodes extend from the second side portion.

A piezoelectric touch device is provided. According to a first aspect, a piezoelectric touch device comprises: a conductive support structure comprising an inseparable section as a bridge separated by a first opening; a piezoelectric element configured to provide a touch sensing and a haptic feedback; connection pads configured to form an electrically connected circuit for the piezoelectric element, wherein the piezoelectric element is electrically connected to the connection pads, and wherein the bridge comprises one of the connection pads and the conductive support structure comprises another of the connection pads; a second opening next to the another connection pad allowing the piezoelectric element to bend freely. The piezoelectric touch device for touch sensing and haptic feedback may be consequently manufactured with an improved manufacturability.

An electromechanical transducer element includes a base substrate, a first electrode on the base substrate, a piezoelectric body on the first electrode, and a second electrode on the piezoelectric body. The base substrate has a void area opposite to the piezoelectric body via the first electrode, and a width of the void area on a cross section cut along a layer direction of the electromechanical transducer element satisfies 0.65≤Pw/Cw≤0.95, where Cw represents the width of the void area, and Pw represents a width of the piezoelectric body on the cross section.

There is provided a method for producing a piezoelectric element, which allows for forming a columnar microstructure with a small width and a high aspect ratio. The method is intended to produce a piezoelectric element 102 including a three-dimensional structure group 20 having a plurality of the three-dimensional structures 21 and 321 formed in a plate-like or columnar shape with a width of 30 μm or less and a height of 80 μm or more. The production method includes a first process of fabricating a plurality of plate-like or columnar precursor shapes 82a on a bulk material 81 formed of a Pb-based piezoelectric material, and a second process of reducing the width of the precursor shapes 82a to a predetermined value using an etching liquid.

A piezoelectric element includes a first electrode layer, a piezoelectric layer, and a second electrode layer. The first electrode layer, the piezoelectric layer, and the second electrode layer are stacked in sequence on one another. The first electrode layer has a first part overlapping the piezoelectric layer in a plan view, and a second part at least partially separated from the first part and not overlapping the piezoelectric layer in the plan view. The second electrode layer has a third part overlapping the piezoelectric layer in the plan view, and a fourth part separated from the third part. The fourth part is in contact with the first part and the second part.

A method for manufacturing a PMUT device including a piezoelectric element located at a membrane element is provided. The method includes receiving a silicon on insulator substrate having a first silicon layer, an oxide layer, and a second silicon layer. Portions of a first surface of the second silicon layer are exposed by removing exposed side portions of the first silicon layer and corresponding portions of the oxide layer, and a central portion including the remaining portions of the first silicon layer and of the oxide layer is defined. Anchor portions for the membrane element are formed at the exposed portions of the first surface of the second silicon layer. The piezoelectric element is formed above the central portion, and the membrane element is defined by selectively removing the second layer and removing the remaining portion of the oxide from under the remaining portion of the first silicon layer.

A micro-machined ultrasonic transducer is proposed. The micro-machined ultrasonic transducer includes a membrane element for transmitting/receiving ultrasonic waves, during the transmission/reception of ultrasonic waves the membrane element oscillating, about an equilibrium position, at a respective resonance frequency. The equilibrium position of the membrane element is variable according to a biasing electric signal applied to the membrane element. The micro-machined ultrasonic transducer further comprises a cap structure extending above the membrane element; the cap structure identifies, between it and the membrane element, a cavity whose volume is variable according to the equilibrium position of the membrane element. The cap structure comprises an opening for inputting/outputting the ultrasonic waves into/from the cavity. The cap structure and the membrane element act as tunable Helmholtz resonator, whereby the resonance frequency is variable according to the volume of the cavity.