An ultrasonic actuator with increased radiating surface is presented. The increased radiating surface is provided by a plurality of piezoelectric stacks that are each compressed by action of a respective bolt against a common backing structure of the actuator. According to one aspect, each of the stacks includes a plurality of stacked piezoelectric rings with the respective bolt arranged through the central opening of the rings. According to another aspect, one or both of the backing structure and the horn of the actuator include tuning grooves and/or tuning slots to produce amplitude uniformity of displacement through the actuator. According to another aspect, the radiating surface has a symmetrical shape about an axial direction of the actuator with a lateral dimension that is in a range between one quarter and one half of the wavelength of operation of the actuator.

Cost effective connectors of high bending stiffness for making high-performance piezoelectric actuators and derivative devices are disclosed. In one embodiment, the connector has circumferentially alternating recesses of circular cross-section which can be cost-effectively machined out with conventional machining techniques. The circular recesses can be adopted to house circular or non-circular cross-sectioned piezoelectric active elements to make cost effective 2-level (2) piezoelectric displacement actuators. In another embodiment, the non-circular cross-sectioned recesses in the connector include suitable wall openings to enable said recesses to be machined out cost effectively via conventional machining techniques, or via reduced use of non-conventional machining techniques. Additional stiffening mechanisms can be added to minimize the bending displacement of the base of recesses when desired. Cost effective derivative devices, such as high-performance multi-level displacement actuators and compact Langevin low-frequency underwater projectors, can be made from such connectors.

A piezoelectric transformer comprises at least a laminate of a first member, a first piezoelectric element, a second piezoelectric element and a second member sequentially stacked one on the other in the above-listed order and a pressurizing mechanism for squeezing the first member and the second member together in the stacking direction. The ratio of the electromechanical coupling coefficient k.sub.33 relative to the electromechanical coupling coefficient k.sub.31 (k.sub.33/k.sub.31) of the first piezoelectric element and the second piezoelectric element is not less than 2.0.

Disclosed is a piezoelectric ceramic stacked structure and a piezoelectric accelerometer. The piezoelectric ceramic stacked structure comprises: a columnar piezoelectric ceramic body comprising a first end portion and a second end portion opposite to each other in the axial direction, wherein the columnar piezoelectric ceramic body comprises two or more piezoelectric ceramic stacked layers, and two adjacent electrodes of two adjacent piezoelectric ceramic stacked layers have same polarity; a surface, facing the first end portion, of each piezoelectric ceramic stacked layer is provided with an electrode lead terminal; and two adjacent electrode lead terminals have opposite polarities and are staggered in the axial direction, and the electrode lead terminal provided on each piezoelectric ceramic stacked layer in the columnar piezoelectric ceramic body is exposed to an external environment; and a connecting component, wherein the two or more piezoelectric ceramic stacked layers are connected by the connecting component.

The present disclosure relates to the technical field of sensors, in particular to a piezoelectric ceramic structure, comprising at least one first piezoelectric layer and at least one second piezoelectric layer stacked on each other, wherein the first piezoelectric layer having a first structure in which a piezoelectric coefficient decreases as temperature increases, and the second piezoelectric layer having a second structure in which a piezoelectric coefficient increases as temperature increases, and an electrode layer is disposed between the first piezoelectric layer and the second piezoelectric layer, and disposed on exposed end surfaces of the first piezoelectric layer and the second piezoelectric layer. A piezoelectric acceleration sensor having the above piezoelectric ceramic structure is also provided. The present disclosure provides a piezoelectric ceramic structure with good high temperature properties and a piezoelectric acceleration sensor having the same.

There is provided a piezo-electric actuator comprising an assembly comprising a first electrode, a second electrode, and at least one piezoelectric layer located between said first electrode and said second electrode, wherein at least one of the first electrode and the second electrode is split into at least two different sub-electrodes, wherein at least part of the assembly is configured to move along an axis perpendicular to a surface of the assembly, in response to an electrical stimulus applied to at least one of said first and second electrodes.

In one general aspect, various embodiments are directed to an ultrasonic surgical instrument that comprises a transducer configured to produce vibrations along a longitudinal axis at a predetermined frequency. In various embodiments, an ultrasonic blade extends along the longitudinal axis and is coupled to the transducer. In various embodiments, the ultrasonic blade includes a body having a proximal end and a distal end, wherein the distal end is movable relative to the longitudinal axis by the vibrations produced by the transducer.

In one general aspect, various embodiments are directed to an ultrasonic surgical instrument that comprises a transducer configured to produce vibrations along a longitudinal axis at a predetermined frequency. In various embodiments, an ultrasonic blade extends along the longitudinal axis and is coupled to the transducer. In various embodiments, the ultrasonic blade includes a body having a proximal end and a distal end, wherein the distal end is movable relative to the longitudinal axis by the vibrations produced by the transducer.

In one general aspect, various embodiments are directed to an ultrasonic surgical instrument that comprises a transducer configured to produce vibrations along a longitudinal axis at a predetermined frequency. In various embodiments, an ultrasonic blade extends along the longitudinal axis and is coupled to the transducer. In various embodiments, the ultrasonic blade includes a body having a proximal end and a distal end, wherein the distal end is movable relative to the longitudinal axis by the vibrations produced by the transducer.

An ultrasonic surgical device is disclosed including a surgical tool including a proximal transducer mounting portion defining a surface, a distal end effector end, and a waveguide disposed therebetween, the waveguide extending along a longitudinal axis. The ultrasonic surgical device further includes a transducer is in mechanical communication with the surface of the transducer mounting portion. The transducer is configured to operate in a D31 mode with respect to the longitudinal axis of the waveguide. Upon activation by an electrical signal having a predetermined frequency component, the transducer is configured to induce a standing wave in the surgical tool to cause the end effector to vibrate, the standing wave having a wavelength proportional to the predetermined frequency component of the electrical signal.