An ultrasound transducer and a method of making this transducer, where the transducer includes at least two piezoelectric elements, oriented adjacent to each other in a stack. Each piezoelectric element includes a first surface which includes an electrode of a first polarity, a second surface which includes an electrode of a second polarity, a thickness between the first surface and the second surface, and an ultrasound transmitting surface. This surface does not include an electrode. The transducer also includes a first electrical connection between a surface of a first of the at least two piezoelectric elements of the first polarity and a surface of a second of the at least two piezoelectric elements of the first polarity and a second electrical connection between a surface of a first of the at least two piezoelectric elements of the second polarity and a surface of a second of the at least two piezoelectric elements of the second polarity.

A piezoelectric device includes a membrane having fibres of a polyhydroxyalkanoate (PHA), having average diameter between 100 nm and 2000 nm, and at least one oxide having piezoelectric properties in a subdivided form having at least one average size between 1 nm and 100 nm. Preferably, the PHA fibres are produced by electrospinning. Advantageously, demonstrating good piezoelectric properties and considering that the piezoelectric device includes PHA, a biodegradable and biocompatible material, the device can be used in biological systems, for example in flexible micro-actuator systems for drug delivery and in the engineering of biological tissues (such as, for example, in pacemaker devices).

The present invention provides a polymer-based piezoelectric composite material from which a piezoelectric film capable of outputting a higher sound pressure and exhibiting excellent flexibility even in a low-temperature environment is obtained in a case of using a piezoelectric speaker, a piezoelectric film formed of the polymer-based piezoelectric composite material, and a piezoelectric speaker and a flexible display which are formed of the piezoelectric film. The polymer-based piezoelectric composite material of the present invention is a polymer-based piezoelectric composite material including a polymer matrix which contains a polymer containing a group represented by Formula (1), and piezoelectric particles.

*-L.sup.1-(CR.sup.1R.sup.2).sub.n—CN  Formula (1)

In Formula (1), L.sup.1 represents a divalent linking group excluding a urethane group. R.sup.1 and R.sup.2 each independently represent a hydrogen atom, an alkyl group, or an aryl group. n represents an integer of 3 or greater. * represents a bonding position with respect to the main chain of a polymer.

A footwear component is disclosed. In various embodiments, the footwear component includes a foam substrate having an upper surface and a lower surface extending in a lateral direction; and a sensing circuit between the upper surface and the lower surface, the sensing circuit including a piezoelectric foam sensor including a piezoelectric foam between a plurality of electrodes, a printed circuit board having a processor electrically connected to the plurality of electrodes by one or more electrical leads, and an antenna electrically connected to the printed circuit board, the antenna being spaced apart from the printed circuit board and the plurality of electrodes in the lateral direction.

Piezoelectric composites are described. A piezoelectric composite can include a polymeric matrix, piezoelectric additive(s), and polyol. Methods of making and using the piezoelectric composite are also described.

A piezoelectric artificial artery can be 3D printed to provide the real-time precise sensing of blood pressure and vessel motion patterns enabling early detection of partial occlusions. An electric-field assisted 3D printing method allows for rapid printing and simultaneously poled complex ferroelectric structures with high fidelity and good piezoelectric performance. The print material consists of ferroelectric potassium sodium niobite (KNN) particles embedded within a ferroelectric polyvinylidene fluoride (PVDF) polymer matrix.

An ultrasound transducer for use in intravascular ultrasound (IVUS) imaging systems including a single crystal composite (SCC) layer is provided. The transducer has a front electrode on a side of the SCC layer; and a back electrode on the opposite side of the SCC layer. The SCC layer may have a bowl shape including pillars made of a single crystal piezoelectric material embedded in a polymer matrix. Also provided is an ultrasound transducer as above, with the back electrode split into two electrodes electrically isolated from one another. A method of forming an ultrasound transducer as above is also provided. An IVUS imaging system is provided, including an ultrasound emitter and receiver rotationally disposed within an elongate member; an actuator; and a control system controlling emission of pulses and receiving ultrasound echo data associated with the pulses. The ultrasound emitter and receiver include an ultrasound transducer as above.

The present application relates to stacked piezoelectric composites comprising piezoelectric structures. Suitably, the composites are useful as tissue-stimulating implants, including spinal fusion implants. The present application also relates to methods of making stacked piezoelectric composites.

A piezoelectric device comprises at least one piezoelectric composite layer P inserted between two conductive composite layers E, each layer E forming an electrode, characterized in that: the layer P is a rubber composition containing more than 50 parts by weight per hundred parts by weight rubber, phr, of diene elastomer, a cross-linking system and at least 5 vol. %, in relation to the total volume of the rubber composition, of piezoelectric inorganic charges; and each layer E is a rubber composition containing at least 50 phr of diene elastomer, a cross-linking system, and conductive charges. A method for producing the device and a tire comprising the device are also disclosed.

Provided is a manufacturing method for piezoelectric resonator and a piezoelectric resonator, The manufacturing method includes forming a monocrystalline piezoelectric material layer on a first substrate; and forming a polycrystalline piezoelectric material layer on a surface far of the monocrystalline piezoelectric material layer away from the first substrate.