Improvements in ingestible electronics with the capacity to sense physiologic and pathophysiologic states have transformed the standard of care for patients. Yet despite advances in device development, significant risks associated with solid, non-flexible gastrointestinal transiting systems remain. Here, we disclose an ingestible, flexible piezoelectric device that senses mechanical deformation within the gastric cavity. We demonstrate the capabilities of the sensor in both in vitro and ex vivo simulated gastric models, quantified its key behaviors in the GI tract by using computational modeling, and validated its functionality in awake and ambulating swine. Our piezoelectric devices can safely sense mechanical variations and harvest mechanical energy inside the gastrointestinal tract for diagnosing and treating motility disorders and for monitoring ingestion in bariatric applications.

Parts made by additive manufacturing are often structural in nature, rather than having functional properties conveyed by a polymer or other component present therein. Printed parts having piezoelectric properties may be formed using compositions comprising a plurality of piezoelectric particles and a polymer material comprising at least one thermoplastic polymer and at least one thermally curable polymer precursor. At a sufficient temperature, the at least one thermally curable polymer precursor may undergo a reaction, optionally also undergoing a reaction with the piezoelectric particles, and form an at least partially cured printed part. The piezoelectric particles may be mixed with the polymer material and remain substantially non-agglomerated when combined with the polymer material. The compositions may define a form factor such as a composite filament, a composite pellet, or an extrudable composite paste, which may be utilized in forming printed part by extrusion, layer-by-layer deposition, and thermal curing.

The present invention is directed to a method for manufacturing an ultrasonic fingerprint sensor by using a nanorod structure, the method including: a conductive mold generating step of generating a plurality of rod generation holes; a nanorod generating step of generating nanorods by filling the plurality of rod generation holes with a nano-piezoelectric material; a side electrode generation portion marking step of marking side electrode generation portions; a conductive mold etching step of generating nanorods and side electrodes by performing primary etching on the conductive mold; an insulating material filling step of filling portions with an insulating material; a lower electrode forming step of performing secondary etching and forming lower electrodes; a dummy substrate bonding step of bonding a dummy substrate to a surface on which the lower electrodes are formed; and an upper electrode forming step of removing the conductive substrate base and forming upper electrodes.

A piezoelectric element includes: a piezoelectric body having a first surface and a second surface that are different from each other; a first electrode provided at the first surface; and a second electrode provided at the second surface. The piezoelectric body contains a helical chiral polymer crystal having an orientation axis as a crystal axis, the orientation axis is uniaxially oriented in a manner of intersecting both the first surface and the second surface, and a degree of orientation of the orientation axis in the piezoelectric body is 0.80 or more.

A very small piezoelectric sensor capable of being mass produced includes a core, a piezoelectric layer on a surface of the core; and a conductive layer on a surface of the piezoelectric layer away from the core. The core is flexible and threadlike, the core is a first electrode of the piezoelectric sensor, and the conductive layer is a second electrode of the piezoelectric sensor. An array of such sensors allows the “skin” of a robot for example to simulate the sensitivity of hair-covered human skin. A method for making the piezoelectric sensor and an electronic device using the piezoelectric sensor are also disclosed.

An active acoustic system includes a thin-film sheet having an array of piezoelectric microstructures embossed in the film. Each piezoelectric microstructure may act as a speaker and/or a microphone. A control circuit is configured to individually address the piezoelectric microstructures to provide a separate voltage signal to, or receive a separate voltage signal from, each piezoelectric microstructure.

A polymer thin film includes polyvinylidene fluoride (PVDF) and is characterized by a Young's modulus along an in-plane dimension of at least 4 GPa, an electromechanical coupling factor (k.sub.31) of at least 0.1 at room temperature. A method of manufacturing such a polymer thin film may include forming a polymer composition into a polymer thin film, applying a tensile stress to the polymer thin film along at least one in-plane direction and in an amount effective to induce a stretch ratio of at least approximately 5 in the polymer thin film, and applying an electric field across a thickness dimension of the polymer thin film. Annealing and poling steps may separately or simultaneously accompany and/or follow the act of stretching of the polymer thin film.

Parts made by additive manufacturing are often structural in nature, rather than having functional properties conveyed by a polymer or other component present therein. Printed parts having piezoelectric properties may be formed using compositions comprising a plurality of piezoelectric particles located in a polymer matrix comprising a first polymer material and a sacrificial material that are immiscible with each other. The sacrificial material, which may comprise a second polymer material, may be removable from the first polymer material under specified conditions. The piezoelectric particles may remain substantially non-agglomerated when combined with the polymer matrix. The polymer matrix may be treated to remove the sacrificial material to introduce a plurality of pores. The compositions may have a form factor such as a composite filament, a composite pellet, a composite powder, or a composite paste. Additive manufacturing processes may comprise forming a printed part by depositing the compositions layer-by-layer.

There is provided a piezoelectric composite comprising a piezoelectric polymer and particles of a filler dispersed in the polymer, wherein the filler is in micro or nanoparticle form and is present in a filler:polymer weight ratio between about 1:99 and about 95:5. There is also provided an ink and ink cartridge for 3D printing of the piezoelectric composite. There is also provided a piezoelectric 3D printed material comprising the piezoelectric composite and a bifunctional material comprising the piezoelectric composite with one or more conductive electrodes adjacent to the piezoelectric composite. Methods of manufacture and uses thereof are also provided, including methods for 3D printing of a piezoelectric 3D printed material via solvent-cast or FDM 3D printing starting from the piezoelectric composite and/or the ink.

High-resolution intravascular ultrasound (H-IVUS) operates under a large acoustic bandwidth, provides high resolution while maintaining good depth penetration, and exhibits other favorable characteristics like focused imaging. A H-IVUS transducer assembly can be manufactured at a low cost using conventional methods commonly utilized in the microelectronics industry. The H-IVUS transducer assembly can include a printed circuit having one or more electrical signal conditioners. One or more convertors made of a polymer and configured to convert electrical energy to acoustic energy and acoustic energy to electrical energy can be formed in place away from the printed circuit. After construction, the one or more formed in place convertors are interfaced to the printed circuit with at least a conductive material.