Activity of piezoelectric material dimension and electrical properties can be changed with an applied stress. These variations are translated to a change in capacitance of the structure. Use of capacitance-voltage measurements for the extraction of double piezoelectric thin film material deposited at the two faces of a flexible steel sheet is described. Piezoelectric thin film materials are deposited using RF sputtering techniques. Gamry analyzer references 3000 is used to collect the capacitance-voltage measurements from both layers. A developed algorithm extracts directly the piezoelectric coefficients knowing film thickness, applied voltage, and capacitance ratio. The capacitance ratio is the ratio between the capacitances of the film when the applied field in antiparallel and parallel to the poling field direction, respectively. Piezoelectric bulk ceramic is used for calibration and validation by comparing the result with the reported values from literature. Extracted values using the current approach match well values extracted by existing methods.

A driving circuit is described. The driving circuit includes: a first piezoelectric actuator including at least one piezoelectric element disposed between a first electrode and a second electrode, the first electrode configured to connected to a first ground at a first terminal and the second electrode configured to connected to an amplifier at a second terminal. The driving circuit includes a second piezoelectric actuator including at least one piezoelectric element disposed between a first electrode and a second electrode, the first electrode configured to connected to a control signal at a first terminal and the second electrode connected to a second ground at a second terminal. And, the first terminal of the first piezoelectric actuator and the first terminal of the second piezoelectric actuator are configured such that the first piezoelectric actuator and the second piezoelectric actuator are symmetrical and have similar polarity.

A multilayer piezoelectric element includes a ceramic body formed by a piezoelectric ceramic, and having first and second end face facing a longitudinal direction, first and second principal faces facing a thickness direction perpendicular to the longitudinal direction. A pair of external electrodes cover the first and second end faces, extend from the first and second end faces onto the first principal face via ridge parts connecting the end faces with the principal faces, and project in the thickness direction on the first principal face. Multiple internal electrodes are stacked inside the ceramic body and are connected alternately to the pair of external electrodes along the thickness direction. A surface electrode is provided on at least one of the first and second principal faces, and connected to the external electrode different from the one to which the internal electrode adjacent in the thickness direction is connected.

A vibration device that includes a flat plate that has a first main surface and a second main surface; a vibrator that is configured to vibrate along a first direction parallel to the first main surface; a connecting member that connects the vibrator to the first main surface of the flat plate; a support member having a cavity or a recess in a portion thereof facing the vibrator; and a cushioning material connecting the first main surface of the flat plate to the support member, the cushioning material being disposed so as to not overlap with the vibrator in a plan view of the vibration device. A combined length of the vibrator and the connecting member in a second direction perpendicular to the first main surface of the flat plate is larger than a length of the cushioning material in the second direction.

A dielectric elastomer transducer Al includes a dielectric elastomer layer 11 and a pair of electrode layers 12 sandwiching the dielectric elastomer layer 11. The electrode layers 12 contain ground carbon particles derived from carbon nanotubes. This configuration ensures both stretchability and electrical conductivity.

An electronic device includes a first substrate having a terminal disposed on a first side surface, a second substrate stacked on the first substrate, a third substrate stacked on a opposite side of the second substrate from the first substrate, and a wiring substrate disposed to face the first side surface and joined to the first side surface via a first joining member, wherein a second side surface of the second substrate that faces the wiring substrate is located on an opposite side of the first side surface from the wiring substrate.

Cost effective connectors of high bending stiffness for making high-performance piezoelectric actuators and derivative devices are disclosed. In one embodiment, the connector has circumferentially alternating recesses of circular cross-section which can be cost-effectively machined out with conventional machining techniques. The circular recesses can be adopted to house circular or non-circular cross-sectioned piezoelectric active elements to make cost effective 2-level (2×) piezoelectric displacement actuators. In another embodiment, the non-circular cross-sectioned recesses in the connector include suitable wall openings to enable said recesses to be machined out cost effectively via conventional machining techniques, or via reduced use of non-conventional machining techniques. Additional stiffening mechanisms can be added to minimize the bending displacement of the base of recesses when desired. Cost effective derivative devices, such as high-performance multi-level displacement actuators and compact Langevin low-frequency underwater projectors, can be made from such connectors.

The invention relates to a body (2), at least one actuator (3) produced from an electro-active polymer material that changes form due to electrical energy, thereby actuating the body (2), at least two strengtheners (4) allowing the actuator (3) to change its form, each holding the actuator (3) from a different side, and are positioned oppositely on the body (2), at least one retainer tip (5) holding the actuator (3) from at least one side thereof.

According to one embodiment, a disk device includes a magnetic disk, a magnetic head, a flexure, a piezoelectric element, a first bonding material, a second bonding material, and a protrusion. The flexure includes a first outer surface, a first pad, and a second pad. The first pad and the second pad are on the first outer surface. The piezoelectric element includes a second outer surface, a first electrode, and a second outer surface. The first electrode and the second electrode are on the second outer surface. The first bonding material, which is conductive, bonds the first pad and the first electrode. The second bonding material, which is conductive, bonds the second pad and the second electrode. The protrusion is provided on the flexure, is located at least partially between the first bonding material and the second bonding material, and protrudes from the first outer surface.

The invention provides an electroactive polymer actuator comprising a capacitance compensation means adapted to at least partially offset any changes in the capacitance across the member induced by its deformation. In this way, the electronic control of the device is rendered much simpler, since a varying capacitance across the actuator member does not have to be accounted for when driving the actuator to perform a particular deformation.