A nanomechanical magnetoelectric antenna includes a thin film heterostructure that has a magnetic element and a piezoelectric element. The heterostructure is suspended on a substrate and is capable of resonating at acoustic resonance frequencies. In the transmission mode of the antenna, oscillating mechanical strain produced by voltage-induced acoustic waves is transferred to the thin film heterostructure through strain mediated magnetoelectric coupling. This gives rise to magnetization oscillation or magnetic current that radiates electromagnetic waves at the acoustic resonance frequencies. In the receiving mode, the heterostructure senses magnetic components of electromagnetic waves arriving at the antenna, converting these into a piezoelectric voltage output.

The disclosure describes new apparatus, systems and methods utilizing magnetoelectric neural stimulators with tunable amplitude and waveform. Specific embodiments of the present disclosure include a magnetoelectric film, a magnetic field generator and an electrical circuit coupled to the magnetoelectric film, in particular embodiments, the electrical circuit comprises components configured modify an electrical output signal produced by the magnetoelectric film. In certain embodiments, the electrical circuit is configured to modify the electric signal to charge a charge storage element, to transmit data to an implantable wireless neural stimulator, and to provide a stimulation output to electrodes.

The present invention relates to a heterostructure, in particular, a piezoelectric structure, comprising a cover layer, in particular, a layer of piezoelectric material, the material of the cover layer having a first coefficient of thermal expansion, assembled to a support substrate, the support substrate having a second coefficient of thermal expansion substantially different from the first coefficient of thermal expansion, at an interface wherein the cover layer comprises at least a recess extending from the interface into the cover layer, and its method of fabrication.

Piezoelectric films including ionic liquids and methods of making piezoelectric films including ionic liquids. The resulting films have higher levels of beta phase and can be poled using external fields without additional treatment, such as stretching. The films are light-transparent. In some embodiments, the piezoelectric material is used to create piezo-electrophoretic films that can be patterned for use as security markers, authentication films, or sensors. The films are generally flexible. Some films are less than 100 μm in thickness. Electrophoretic displays formed from the piezoelectric films do not require an external power source.

A method for producing a layer of composition AA′BO.sub.3, wherein A consists of at least one element selected from the group consisting of: Li, Na, K, Ca, Mg, Ba, Sr, Pb, La, Bi, Y, Dy, Gd, Tb, Ce, Pr, Nd, Sm, Eu, Ho, Zr, Sc, Ag and Tl, and B consists of at least one element selected from the group consisting of: Nb, Ta, Sb, Ti, Zr, Sn, Ru, Fe, V, Sc, C, Ga, Al, Si, Mn, Zr and Tl, is described. The method includes providing a donor substrate of composition ABO.sub.3, forming a layer of composition ABO.sub.3 by thinning the donor substrate, and exposing the layer of composition ABO.sub.3 to a medium containing ions of an element A′ belonging to the same list of elements as A, A′ being different from A, such that the ions penetrate into the layer of composition ABO.sub.3 to form the layer of composition AA′BO.sub.3.

A piezoelectric element 10 includes a lower electrode, constituted of a Pt/Ti laminated film, a PLT seed layer, formed on the lower electrode, a PZT piezoelectric film, formed on the PLT seed layer, and an upper electrode, formed on the PZT piezoelectric film. A curve Q1 is a curve drawn such as to pass through a plurality of plotted points, each expressing a PLT (100) peak intensity with respect to a Pt (111) peak intensity according to a substrate setting temperature during forming of the Pt/Ti laminated film. A relationship of the PLT (100) peak intensity with respect to the Pt (111) peak intensity is within a range in the curve Q1 until the PLT (100) peak intensity decreases by 5% from a peak point P, at which the PLT (100) peak intensity is the maximum, and a (100) orientation rate of PLT constituting the seed layer is not less than 85%.

There is provided a piezoelectric laminate, including: a substrate; and a piezoelectric film formed on the substrate, wherein the piezoelectric film contains an alkali niobium oxide represented by a composition formula of (K.sub.1−xNa.sub.x)NbO.sub.3 (0<x<1), having a perovskite structure, and contains a metallic element selected from a group consisting of Cu and Mn at a concentration of more than 0.6 at % and 2.0 at % or less.

A ferroelectric material includes a mixed crystal having AlN and at least one nitride of a transition metal. The proportion of the nitride of the transition metal is selected such that a direction of an initial or spontaneous polarity of the ferroelectric material is switchable by applying a switchover voltage. The switchover voltage is below a breakdown voltage of the ferroelectric material.

There is provided a piezoelectric stack, including: a substrate; an oxide film on the substrate, containing zinc and oxygen as main elements; an electrode film on the oxide film; and a piezoelectric film on the electrode film, being an alkali niobium oxide film containing potassium, sodium, niobium, and oxygen and having a perovskite structure.

A material that includes a polymer foam and at least one polar dopant molecule included in the polymer foam, wherein the material is a piezoelectric.