An electroactive device may include (1) an electroactive polymer element having a first surface and a second surface opposite the first surface, the electroactive polymer element comprising a nanovoided polymer material, (2) a primary electrode abutting the first surface of the electroactive polymer element, and (3) a secondary electrode abutting the second surface of the electroactive polymer element. The electroactive polymer element may be deformable from an initial state to a deformed state by application of an electrostatic field produced by a potential difference between the primary electrode and the secondary electrode. Various other devices, systems, and methods are also disclosed.

Provided is a piezoelectric material filler including alkali niobate compound particles having a ratio (K/(Na+K)) of the number of moles of potassium to the total number of moles of sodium and potassium of 0.460 to 0.495 in terms of atoms and a ratio ((Li+Na+K)/Nb) of the total number of moles of alkali metal elements to the number of moles of niobium of 0.995 to 1.005 in terms of atoms. The present invention can provide a piezoelectric material filler having excellent piezoelectric properties, and a composite piezoelectric material including the piezoelectric material filler and a polymer matrix.

An object of the present invention is to provide a piezoelectric polymer film having excellent piezoelectric characteristics. The object is achieved by providing a piezoelectric polymer film including a piezoelectric layer containing lead zirconate titanate particles in a matrix that contains a polymer material, and an electrode layer provided on each of both surfaces of the piezoelectric layer, in which a Raman shift of a maximum peak present in a range of 190 to 215 cm.sup.−1 in a Raman spectrum of the piezoelectric layer is 205 cm.sup.−1 or less.

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.

Lattice structure with piezoelectric behavior characterized in that the lattice structure (1) comprises a periodic succession of unitary cells (10), wherein each unitary cell (10) is made of a dielectric material, is bending or torsion dominated and comprises nanometric structural connectors (11) connected to each other through nodes (12) defining a non-centrosymmetric shape having a topological constraint that induces torsion or bending of said structural connectors (11); and wherein the unitary cells (10) are connected to each other at least in series defining a continuous electric potential accumulation path with two opposed ends (2, 3), the unitary cells (10) being arranged within the lattice structure (1) in a non-centrosymmetric disposition accumulating and conducting without cancellation the electric gradient generated on each unitary cell (10) through the lattice structure (1) to said two opposed ends (2, 3).

A piezoelectric device includes a membrane portion including a through slot extending through the membrane portion in an up-down direction. A width of the through slot in a single crystal piezoelectric material layer becomes narrower as the through slot extends downward. In the single crystal piezoelectric material layer and a reinforcing layer, a maximum width of the through slot in a layer located on a bottom side is smaller than a minimum width of the through slot in a layer located on a top side.

Smart dental implant systems and methods for ambulatory dental care are provided. In some embodiments, the disclosed subject matter includes a crown, adapted to mimic a patient's anatomy and location of the smart dental implant system. The crown can include piezoelectric nanoparticles, disposed on a surface of the crown and adapted to generate electricity from a patient's oral motion. In some embodiments, the disclosed subject matter includes an abutment, coupled to the crown. The abutment can include an energy harvesting circuit, operationally coupled to the piezoelectric nanoparticles and adapted to harvest the electricity, and a micro LED array, operationally coupled to the energy harvesting circuit and adapted to photobiomodulate surrounding peri-implant soft tissue.

Embodiments of the present disclosure relate to a display substrate, a method for manufacturing the same, and a display device. The display substrate includes a substrate, a pixel definition layer for defining pixels on the substrate, the pixel definition layer including a plurality of inter-pixel portions located between adjacent pixels, and a fingerprint recognition sensor located in the inter-pixel portions.

A polymer composite exhibiting piezoelectric properties can be formed for flexible and/or thin film applications, in which the polymer composite includes a polymer matrix and a piezoelectric ceramic filler embedded in the polymer matrix. The polymer matrix may include at least two polymers: a first polymer and a second polymer. The first polymer may be a fluorinated polymer, and the second polymer may be compatible with the first polymer and have a dielectric constant of less than approximately 20. The piezoelectric ceramic filler may be a lead-free ceramic filler, such as barium titanate, and be approximately 40-70% by volume of the polymer composite. The remaining 30-60% by volume may be the polymer matrix, which may itself be approximately 5-20% by weight second polymer and 80-95% fluorinated polymer.

There is provided a piezoelectric laminate has, on a substrate in the following order, a lower electrode layer and a piezoelectric film containing a perovskite-type oxide as a main component. The piezoelectric film has an oxygen-deficient region in a region in contact with the lower electrode layer. In a case where an average value of oxygen amounts in a region centrally located among three regions obtained by dividing the piezoelectric film into three equal parts in a thickness direction is denoted as a first average oxygen amount, and an average value of oxygen amounts in the oxygen-deficient region is denoted as a second average oxygen amount, a ratio R of the second average oxygen amount to the first average oxygen amount is less than 0.97. A thickness of the oxygen-deficient region is 120 nm or more and is ⅓ or less of a thickness of the entire piezoelectric film.