Acoustic transducers can be formed form piezoelectric materials including one or more curved (non-linear) segments. The piezoelectric material can be shear poled such that a poling direction of the piezoelectric material can follow the curvature of the piezoelectric material. The piezoelectric material can also have a unidirectional poling direction. In some examples, the piezoelectric material can be a closed ring with a circular or partially circular shape. A shear poling process for a piezoelectric material with curves can include shear poling segments of the piezoelectric material with one or more sets of poling electrodes. The poling electrodes of a respective one of the one or more sets of poling electrodes can be coupled to the same side of the piezoelectric material.

In the system, two ultrasonic transducers, which form a pair and each have a piezoelectric ceramic plate-shaped element with a rectangular geometry, can be fastened to a surface of a component. The two ultrasonic transducers are arranged at a distance from one another such that there is no direct mechanical contact and they are arranged beside one another with a parallel orientation of their central longitudinal axes. The two elements have a different polarization along their width and are connected with the same polarity to an electrical voltage source. The two plate-shaped elements can also have an identical polarization along their width and can be connected in this case with opposite polarity to an electrical voltage source. At least one ultrasonic transducer and/or at least one further ultrasonic transducer is/are designed to detect ultrasonic waves reflected by defects and/or shear waves simultaneously emitted by the two ultrasonic transducers.

According to some examples a substance displacement apparatus may comprise a gas ejection aperture and a deflector arm. The gas ejection aperture may be to direct gas towards a roller having a surface on which a substance is disposed. The deflector arm may be moveable between a first position in which gas is directed away from a target area on the surface of the roller, and a second position in which gas is directed towards the target area on the surface of the roller, thereby to displace at least some of the substance from the surface of the roller within the target area. A method and a print apparatus are also disclosed.

An apparatus comprises a stressed glass member and an actuator mounted on the stressed glass member. A power source is coupled to the actuator. An abrasion structure is disposed between the actuator and the stressed glass member. The abrasion structure comprises abrading features in contact with the stressed glass member. The abrading features have a hardness higher than a hardness of the stressed glass member. When energized by the power source, the actuator is configured to induce movement of the abrasion structure that causes the abrading features to create scratches in the stressed glass member to a depth sufficient to initiate fracture of the stressed glass member.

An apparatus comprises a stressed glass member and an actuator mounted on the stressed glass member. A power source is coupled to the actuator. An abrasion structure is disposed between the actuator and the stressed glass member. The abrasion structure comprises abrading features in contact with the stressed glass member. The abrading features have a hardness higher than a hardness of the stressed glass member. When energized by the power source, the actuator is configured to induce movement of the abrasion structure that causes the abrading features to create scratches in the stressed glass member to a depth sufficient to initiate fracture of the stressed glass member.

The present invention discloses a piezoelectric device comprising an amino acid crystal.

There is disclosed a piezoelectric ceramic having the composition: a[PbTiO.sub.3]-b[SrTiO.sub.3]-c[BiFeO.sub.3]-d[(K.sub.xBi.sub.1-x)TiO.sub.3]; wherein 0.4<x<0.6; 0.1<a<0.4; 0.01<b0.2; c0.05; d0.01; and a+b+c+d=1 optionally comprising an A- or B-site metal dopant in an amount of up to 2 at. %.

A vibration device includes a light-transmitting body that is located on a subject side of an imaging element, a cylindrical body that includes a first end portion, a second end portion on the opposite side from the first end portion, and an outer surface and an inner surface that connect the first end portion and the second end portion to each other, the cylindrical body being connected to the light-transmitting body and holding the light-transmitting body on the first end portion side thereof, and a piezoelectric element provided along a circumferential direction of the cylindrical body and that torsionally vibrates the cylindrical body.

A shear vibration-based piezoelectric composite material and a preparation method thereof are disclosed. The piezoelectric composite material includes a piezoelectric material and the passive material. The piezoelectric material includes a piezoelectric material polarized along the x-axis positive and a piezoelectric material negatively polarized along the x-axis. The piezoelectric materials in the two polarization directions are alternately arranged along the x-axis direction. The passive material includes a filling layer, a transition layer, and a planar layer. The filling layer is disposed between every two adjacent piezoelectric materials. The planar layer is located outer two surfaces perpendicular to the z-axis of the piezoelectric material. The planar layer on one side is fixedly connected to the filling layer in the odd-numbered position via the transition layer. The planar layer on the other side is fixedly connected to the filling layer in the even-numbered position via the transition layer. The piezoelectric composite material can be used to prepare an underwater acoustic transducer, a hydrophone, piezoelectric energy harvesters, and the like. The invention innovatively converts shear vibrations into the thickness vibrations of the upper and lower surfaces of the composite material, thereby improving the performance of the composite material.

The present invention relates to a shear deformation-type bimorphic piezoelectric actuator. The actuator includes at least a pair of shear deformation-type piezoelectric ceramic members which are polarized in the height direction thereof, coated with metal electrodes on both sides thereof and attached to opposite sides of a metal block to constitute a piezoelectric bimorph. The ceramic members are forced to undergo a face shear deformation or a resonance deformation upon receiving a driving voltage, whereby the metal block and the output head mounted thereon are driven to generate an elliptical motion, which in turn drives a rotor or a carriage to move. Taking advantage of the small dimension of the ceramic members and the enhanced displacement attributed to the piezoelectric bimorph structure, the piezoelectric actuator disclosed herein is suitable for manufacturing a miniature piezoelectric motor with high power output.