Curved piezoelectric transducers are provided. The curved piezoelectric transducer includes a substrate, a curved support layer having a peripheral portion in contact with the substrate, and a curved piezoelectric element disposed on the curved support layer. Methods of making the curved piezoelectric transducers are also provided. The curved piezoelectric transducers, devices and methods find use in a variety of applications, including devices, such as electronics devices, having one or more (e.g., an array) of the curved piezoelectric transducers on a substrate.

Micromachined ultrasonic transducer (MUT) arrays capable of multiple resonant modes and techniques for operating them are described, for example to achieve both high frequency and low frequency operation in a same device. In embodiments, various sizes of piezoelectric membranes are fabricated for tuning resonance frequency across the membranes. The variously sized piezoelectric membranes are gradually transitioned across a length of the substrate to mitigate destructive interference between membranes oscillating in different modes and frequencies.

A method of manufacturing a piezoelectric element includes: forming a patterned mask layer over a substrate, in which the patterned mask layer has an opening exposing a portion of the substrate; forming a piezoelectric element in the opening; and removing the patterned mask layer to obtain the piezoelectric element, in which the piezoelectric element has a central portion and a peripheral portion adjacent to the central portion, and the peripheral portion has a maximum height greater than a height of the central portion.

A piezoelectric film having a porosity between 20 and 40%, a thickness ranging from tens of microns to less than a few millimeters can be used to form an ultrasonic transducer UT for operation in elevated temperature ranges, that emit pulses having a high bandwidth. Such piezoelectric films exhibit greater flexibility allowing for conformation of the UT to a surface, and obviate the need for couplings or backings. Furthermore, a method of fabricating an UT having these advantages as well as better bonding between the piezoelectric film and electrodes involves controlling porosity within the piezoelectric film.

Techniques and mechanisms to provide mechanical support for a micromachined piezoelectric transducer array. In an embodiment, a transducer array includes transducer elements each comprising a respective membrane portion and a respective supporting structure disposed on or around a periphery of that membrane portion. The transducer elements are initially formed on a sacrificial wafer, wherein supporting structures of the transducer elements facilitate subsequent removal of the sacrificial wafer and/or subsequent handling of the transducer elements. In another embodiment, a polymer layer is disposed on the transducer elements to provide for flexible support during such subsequent handling.

A pattern formation method includes forming an electromagnetic wave blocking structure having a region on a one side of a support substrate, a reflectance of an electromagnetic wave in the region being lower than a reflectance in an area outside the region; forming a mask layer provided with an opening corresponding to the region and configured to be thermally decomposed at a predetermined temperature on an other side of the support substrate; forming a first heated layer in the opening; and shedding an electromagnetic wave from the one side of the support substrate on the electromagnetic wave blocking structure, wherein an intensity of the electromagnetic wave is determined such that a temperature of the mask layer is less than the predetermined temperature and a temperature of the first heated layer being heated is greater than or equal to the predetermined temperature.

A piezoelectric film having a porosity between 20 and 40%, a thickness ranging from tens of microns to less than a few millimeters can be used to form an ultrasonic transducer UT for operation in elevated temperature ranges, that emit pulses having a high bandwidth. Such piezoelectric films exhibit greater flexibility allowing for conformation of the UT to a surface, and obviate the need for couplings or backings. Furthermore, a method of fabricating an UT having these advantages as well as better bonding between the piezoelectric film and electrodes involves controlling porosity within the piezoelectric film.

An electro-mechanical transducer element is disclosed. The electro-mechanical transducer element includes a first electrode formed on a substrate; an electro-mechanical transducer film formed on at least a part of the first electrode; and a second electrode formed on at least a part of the electro-mechanical transducer film. In at least one cross section of the electro-mechanical transducer film, a film thickness distribution shape is convex to the second electrode side.

A method of fabricating an electromechanical transducer film includes applying a precursor solution on a support substrate, heating the substrate at a first temperature to form a ceramic thin-film in amorphous state, applying a sol-gel solution onto the ceramic thin-film, and heating the ceramic thin-film at a second temperature to form an electromechanical transducer thin-film in amorphous state. The method further includes heating the ceramic and transducer thin-films at a third temperature to thermally decompose an organic substance in the sol-gel solution and form a unitary thin-film, processing the unitary thin-film to form a patterned unitary thin-film, modifying an area on which the patterned film is not formed, discharging the sol-gel solution onto a surface of the patterned film by a liquid discharge head to apply the sol-gel solution to the surface of the patterned film, and heating the patterned film at a fourth temperature to crystallize the patterned film.

Parts made by additive manufacturing are often structural in nature, rather than having functional properties conveyed by a polymer or other component. Printed parts having piezoelectric properties may be formed using compositions comprising a plurality of piezoelectric particles non-covalently interacting with at least a portion of a polymer material via - bonding, hydrogen bonding, electrostatic interactions stronger than van der Waals interactions, or any combination thereof. The piezoelectric particles may be dispersed in the polymer material and remain substantially non-agglomerated when combined with the polymer material. The polymer material may comprise at least one thermoplastic polymer, optionally further including a polymer precursor. The compositions may define an extrudable material that is a composite having a form factor such as a composite filament, a composite pellet, a composite powder, or a composite paste. Additive manufacturing processes using the compositions may comprise forming a printed part by depositing the compositions layer-by-layer.