Provided is a friction drive actuator that is resistant to contamination of, for example, extraneous matter. An ultrasonic actuator according to an aspect of the present invention drives a columnar insertion section and includes a columnar vibrating body (40), whose distal end is pressed against a side surface of the insertion section, and a piezoelectric element (44), an upper electrode (44a), and a lower electrode (44b) that are provided at one side surface of the vibrating body.

Disclosed herein are energy harvesting devices and methods of making and use thereof. The energy harvesting devices can efficiently harvest energy for motions at a frequency of 5 Hz or less.

Embodiments of the invention include piezoelectrically driven switches that are used for modifying a background color or light source color in display systems, and methods of forming such devices. In an embodiment, a piezoelectrically actuated switch for modulating a background color in a display may include a photonic crystal that has a plurality of blinds oriented substantially perpendicular to a surface of the display. In an embodiment, the blinds include a black surface and a white surface. The switch may also include an anchor spaced away from an edge of the photonic crystal and a piezoelectric actuator formed on the surface of the anchor and a surface of the photonic crystal. Some embodiments may include a photonic crystal that is a multi-layer polymeric structure or a polymer chain with a plurality of nanoparticles spaced at regular intervals on the polymer chain.

An actuator device (21) comprises an electroactive polymer (EAP) and a driver (20) for generating a electrical drive signals which give opposite polarity voltages and thus electrical field within the electroactive polymer at different times. In this way, charge build-up can be reduced or avoided, while prolonged activation times are still possible. This improves the performance and/or lifetime of the device.

A flexible display, including: a flexible display panel; an electroactive polymer layer disposed on a side of the flexible display panel that faces away from a displaying surface of the flexible display panel; and a first electrode layer and a second electrode layer which are disposed on the electroactive polymer layer. The electroactive polymer layer is capable of deforming according to the voltage applied across the first electrode layer and the second electrode layer.

An ultrasonic motor comprising a rotor (18) having an at least partly spherical shape and two actuators (2, 2) each comprising an element of plate-shaped piezoelectric material comprising at least one contact edge (4, 4) in contact with the rotor (18), said actuators (2, 2) also comprising on one of their faces electrodes intended to bias piezoelectric materials in a bending mode and in a longitudinal mode. The contact edges (4, 4) are concave and are formed by an arc of circle the radius of which substantially corresponds to the radius of the surface of the rotor (18), said arcs of circle angularly extending at a determined angle such that the bending mode and the longitudinal mode in which the piezoelectric material is biased are at the same frequency.

Piezoelectric crystal elements are provided having preferred cut directions that optimize the shear mode piezoelectric properties. In the discovered cut directions, the crystal elements have super-high piezoelectric performance with d.sub.15, d.sub.24 and d.sub.36 shear modes at room temperature. The d.sub.15 shear mode crystal gives a maximum d value and is free from the cross-talk of d.sub.11 and d.sub.16. The d.sub.36 mode is extremely reliable compared to other shear elements due to its ready re-poling capability. The crystal elements may be beneficially used for high-sensitive acoustic transducers.

A servovalve includes a fluid transfer valve assembly comprising a supply port and a control port, a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal, and a drive assembly configured to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow. The drive assembly includes a steerable member moveable by an amount determined by the control signal to cause corresponding movement of the valve spool. The drive assembly further includes piezoelectric actuator means configured to move said steerable member in response to the control signal.

The invention is an actuating drive for deflecting an actuating element using a solid body actuator (2) when an electrical voltage or an alternating magnetic field is applied, to cause a change in length. A housing (1) encloses the solid body actuator to define an interspace (13) in a fluid-tight manner. Furthermore, the solid body actuator includes a hollow duct (6) having one end connected to a first hollow conduit (20) passing through the housing and the other end opening into the interspace (13). The interspace is additionally connected in a fluid-tight manner to a second hollow conduit (21) passing through the housing.

Aspects of the disclosure include using piezoelectric devices to break laminated glass assemblies on demand (e.g., a windshield of a vehicle). An exemplary vehicle includes a laminated glass panel having an outer glass layer, an inner glass layer, and a bonding layer between the outer glass layer and the inner glass layer. The vehicle further includes a piezoelectric device including an actuator and a displaceable element coupled to the actuator. The actuator is made of a piezoelectric material that, responsive to receiving an activation voltage, induces a mechanical displacement in the displaceable element against at least one of the outer glass layer and the inner glass layer. The vehicle includes a controller electrically coupled to the actuator. The controller is configured to deliver the activation voltage to the actuator.