A diaphragm for a piezoelectric micromachined ultrasonic transducer (PMUT) is presented having resonance frequency and bandwidth characteristics which are decoupled from one another into independent variables. Portions of at least the piezoelectric material layer and backside electrode layer are removed in a selected pattern to form structures, such as ribs, in the diaphragm which retains stiffness while reducing overall mass. The patterned structure can be formed by additive, or subtractive, fabrication processes.

An hourglass transducer including a longitudinal driver, a shell, and a pair of endcaps is provided. The driver drives the transducer. The pair of endcaps is attached to ends of the driver and cap the shell enclosing the transducer. The shell includes a first shell end, a second shell end, and a pleated geometry. The first shell end and second shell end are structured with circular cross sections. The pleated geometry is between the first shell end and the second shell end. A perimeter of the pleated geometry is the same as perimeters of the circular cross sections of the first shell end and the second shell end.

A vibration device includes a base substrate made of silicon and having a first surface and a second surface facing away from the first surface, a lid bonded to the base substrate, a vibrator disposed at the first surface of the base substrate and accommodated in a space between the base substrate and the lid, and a thermistor element disposed at the base substrate.

An apparatus includes a first support member, a second support member and one or more electro-active polymer members between the first support member and the second support. The one or more electro-active polymer members include a first end configured to be coupled to the first support member, a second end configured to be coupled to the second support member and a middle portion located between the first end and the second end, where the middle portion includes a curved member in a first state of the one or more electro-active polymer members. A curved shape of the one or more electro-active polymer members is configured to create linear movement in a vertical direction, by bending in a curved direction.

Flextensional transducers and methods of using flextensional transducers. The transducer includes a piezoelectric element and may include at least one endcap coupled with the piezoelectric element. The endcap may have an outer portion formed of a first material and an inner portion formed of a second material having a greater flexibility than the first material. The endcap may be coupled with an annular piezoelectric element near either its outer circumference or its inner circumference. The piezoelectric element may be a planar disk or have a curved bowl-shape. The transducer may be coupled with, and at least partially restrained by, a support structure. The transducer may also be configured to permit light to pass therethrough.

In accordance with embodiments of the present disclosure, a flextensional transducer for underwater operation includes a driving element and a stave. The stave is made from a material with elastic properties and has a porous structure. The porous structure is adapted to be modelled such that when in use, said porous structure of the stave is of an arbitrary alignment with respect to, for instance, the driving element, and has a degree of porosity. The degree of porosity is such that the elastic properties and vibrational frequency response of the stave can be customised with respect to its intended use.

An apparatus includes a first support member, a second support member and one or more electro-active polymer members between the first support member and the second support. The one or more electro-active polymer members include a first end configured to be coupled to the first support member, a second end configured to be coupled to the second support member and a middle portion located between the first end and the second end, where the middle portion includes a curved member in a first state of the one or more electro-active polymer members. A curved shape of the one or more electro-active polymer members is configured to create linear movement in a vertical direction, by bending in a curved direction.

Disclosed are apparatuses, systems, and methods for use of an acoustic projector. An embodiment discloses an acoustic projector comprising a fixed plate; a first bender plate coupled to a first side of the fixed plate; a second bender plate coupled to a second side of the fixed plate, opposite to the first side; a first driver coupled to the first side of the fixed plate and to the first bender plate to oscillate the first bender plate; and a second driver coupled to the second side of the fixed plate and to the second bender plate to oscillate the second bender plate.

A sound transducer, including a diaphragm and at least one piezoactuator, which is situated in an operative connection to the diaphragm, the oscillation direction of the piezoactuator being situated at least generally perpendicularly in relation to the oscillation direction of the diaphragm, at least one lever element being situated between the diaphragm and the piezoactuator, which connects the diaphragm to the piezoactuator and is designed to convert oscillations of the piezoactuator into oscillations of the diaphragm and vice versa, and a clamp connection being formed between the at least one lever element, and the piezoactuator. The clamp connection is formed between an end face of the piezoactuator situated in the oscillation direction of the piezoactuator and the at least one lever element, and the piezoactuator is situated under an axial pre-tension force extending in the oscillation direction of the piezoactuator by the at least one lever element.

A vibration device includes a base substrate made of silicon and having a first surface and a second surface facing away from the first surface, a lid bonded to the base substrate, a vibrator disposed at the first surface of the base substrate and accommodated in a space between the base substrate and the lid, and a thermistor element disposed at the base substrate.