Disclosed are a piezoelectric speaker employing a piezoelectric device having a through-hole and a method for manufacturing the same. The piezoelectric speaker includes a piezoelectric device including a stacked body having through-holes and electrodes formed at the stacked body, an adhesive layer disposed on the lower surface of the piezoelectric device, and a diaphragm attached to the piezoelectric device by the adhesive layer. The through-holes are arranged to decrease in size as they move away from the center of the piezoelectric element. The through-holes have a symmetrical arrangement with respect to the center, and the inner surface of each through-hole has a curved edge. The structure and arrangement of these through-holes do not cause cracks during the sintering process.

A multilayer piezoelectric element includes a piezoelectric element body, a first internal electrode and a second internal electrode, a plurality of first connecting conductors, a plurality of second connecting conductors, and an external member. The piezoelectric element body is formed by laminating a plurality of piezoelectric element body layer. The piezoelectric element body includes a first main surface and a second main surface, and a side surface. The plurality of first connecting conductors are connected to the first internal electrode. The plurality of second connecting conductors are connected to the second internal electrode. The external member is conductive and is bonded to the first main surface in such a way as to cover the first end portions of the plurality of first connecting conductors. The external member is electrically connected to the plurality of first connecting conductors.

At least one silicone layer is applied to a substrate by a method employing laser transfer printing. The method is suitable for producing sensors, actuators and other EAP layer systems. The silicone layer in these systems may serve as an electrically conducting electrode layer or as a dielectric layer. The method may be configured to be continuous and may be combined with various other coating technologies.

Methods for manufacturing resonator structures and corresponding resonator structures are described. A first wafer including a first piezoelectric material is singulated and bonded to a second wafer.

A wafer scale ultrasonic sensor assembly includes a wafer substrate, an ultrasonic element, first and second protective layers, conductive wires, a transmitting material, an ASIC, a conductive bump, and a soldering portion. The wafer substrate includes a via. The ultrasonic element is exposed to the via. The conductive wires are on the first protective layer and connected to the ultrasonic element. The second protective layer covers the conductive wires, and the second protective layer has an opening corresponding to the ultrasonic element. The transmitting material contacts the ultrasonic element. The ASIC is connected to the wafer substrate, so that the via forms a space between the ASIC and the ultrasonic element. The conductive pillar is in a via defined through the ASIC, the wafer substrate, and the first protective layer, and the conducive pillar is respectively connected to the conductive wires and the soldering portion.

An ultrasound transducer and a method of making this transducer, where the transducer includes at least two piezoelectric elements, oriented adjacent to each other in a stack. Each piezoelectric element includes a first surface which includes an electrode of a first polarity, a second surface which includes an electrode of a second polarity, a thickness between the first surface and the second surface, and an ultrasound transmitting surface. This surface does not include an electrode. The transducer also includes a first electrical connection between a surface of a first of the at least two piezoelectric elements of the first polarity and a surface of a second of the at least two piezoelectric elements of the first polarity and a second electrical connection between a surface of a first of the at least two piezoelectric elements of the second polarity and a surface of a second of the at least two piezoelectric elements of the second polarity.

A hybrid ferroelectric/non-ferroelectric piezoelectric microresonator is disclosed. The hybrid microresonator uses a ferroelectric layer as the actuator as ferroelectric materials typically have higher actuation coefficients than non-ferroelectric piezoelectric materials. The hybrid microresonator uses a non-ferroelectric piezoelectric layer as the sensor layer as non-ferroelectric piezoelectric materials typically have higher sensing coefficients than ferroelectric materials. This hybrid microresonator design allows the independent optimization of actuator and sensor materials. This hybrid microresonator design may be used for bulk acoustic wave contour mode resonators, bulk acoustic wave solidly mounted resonators, free-standing bulk acoustic resonators, and piezoelectric transformers.

An in-situ poled ferroelectric prints with true 3D geometry is provided with an intercalated electrode design where soft polymer matrixes are selected for the ferroelectric layers, and rigid polymer matrixes are selected for the electrode layers, thus mimicking nacre architecture with a ceramic-like piezoelectric property and bone-like fracture toughness. Lithium-doped potassium sodium niobite (Li-KNN) microparticles may be used to produce ferroelectric properties and to create strong interfacial bonding with the interfacing electrode layers. Polylactic acid (PLA) in the electrode layers may be used to facilitate strong interfacial bonding with the Li-KNN microparticles.

A piezoelectric microelectromechanical structure is provided with a piezoelectric stack having a main extension in a horizontal plane and a variable section in a plane transverse to the horizontal plane. The stack is formed by a bottom-electrode region, a piezoelectric material region arranged on the bottom-electrode region, and a top-electrode region arranged on the piezoelectric material region. The piezoelectric material region has, as a result of the variable section, a first thickness along a vertical axis transverse to the horizontal plane at a first area, and a second thickness along the same vertical axis at a second area. The second thickness is smaller than the first thickness. The structure at the first and second areas can form piezoelectric detector and a piezoelectric actuator, respectively.

A piezoelectric artificial artery can be 3D printed to provide the real-time precise sensing of blood pressure and vessel motion patterns enabling early detection of partial occlusions. An electric-field assisted 3D printing method allows for rapid printing and simultaneously poled complex ferroelectric structures with high fidelity and good piezoelectric performance. The print material consists of ferroelectric potassium sodium niobite (KNN) particles embedded within a ferroelectric polyvinylidene fluoride (PVDF) polymer matrix.