Micromachined ultrasonic transducer wherein a die including semiconductor material accommodates at least one ultrasonic cell. Each ultrasonic cell includes a piezoelectric structure, a cavity, and a membrane region, vertically aligned with each other. The cavity extends inside the die and downwardly delimits the membrane region. The piezoelectric structure is arranged on the membrane region and has at least one annular-shaped piezoelectric region. The micromachined ultrasonic transducer is configured to operate around the second axisymmetric vibration mode.

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.

A positioning device includes a positioning element that is situated movably in a first direction and a second direction, the first and the second directions being opposed to one another, and a first piezoelectric actuator and a second piezoelectric actuator, the first piezoelectric actuator moving the positioning element in the first direction and the second piezoelectric actuator moving the positioning element in the second direction.

An ultrasonic transducer, including a piezoelectric element with physical characteristics of radial resonant frequencies and thickness resonant frequencies, and with an upper surface and a lower surface opposite to each other through the piezoelectric element and a lateral surface connecting the upper surface and the lower surface, and an acoustic matching layer set on the upper surface of the piezoelectric element and having a first resonant matching part and a second resonant matching part, wherein a thickness of the first resonant matching part in a direction perpendicular to the upper surface is greater than a thickness of the second resonant matching part in the direction, and the thickness of the first resonant matching part matches one radial resonant frequency of the piezoelectric element and the thickness of the second resonant matching part matches another radial resonant frequency or one of the thickness resonant frequency of the piezoelectric element.

In an embodiment, a method includes bonding a first surface of a first substrate to a second substrate using thermo-compression bonding (TCB) to form a wafer, where the first substrate includes lithium niobate, and the second substrate includes silicon, performing a first annealing process on the wafer at a first temperature, performing a planarization process on a second surface of the first substrate, where the second surface is on an opposite side of the first substrate as the first surface; and performing a second annealing process on the wafer at a second temperature, where the second temperature is greater than the first temperature.

A method of fabricating an ultrasonic medical device is presented. The method includes machining a surgical tool from a flat metal stock, contacting a face of a first transducer with a first face of the surgical tool, and contacting a face of a second transducer with an opposing face of the surgical tool opposite the first transducer. The first and second transducers are configured to operate in a D31 mode with respect to the longitudinal portion of the surgical tool. Upon activation, the first transducer and the second transducer are configured to induce a standing wave in the surgical tool and the induced standing wave comprises a node at a node location in the surgical tool and an antinode at an antinode location in the surgical tool.