An actuator includes a laminate including an elastomer layer and an electrode, in which the laminate has a spiral or concentric shape, pre-distortion is applied to at least one member out of the elastomer layer and the electrode, and area distortion of the at least one member is 10% or larger.

A safety valve is provided with an electronic control unit for generating a control voltage. An electro-fluidic preliminary stage has a piezo bending actuator which can be actuated between a working position and a safety position by the control voltage and influences the flow of a secondary control fluid flow depending on its position. A fluid-mechanical main stage has an influencing device for influencing the flow of a primary working fluid flow. The influencing device can be actuated by means of the secondary control fluid flow which flows into a control chamber of the main stage. The control unit caries out a test of the preliminary stage repeatedly in an iterative manner after the expiration of a specified time interval. As part of the functionality test, the position of the piezo bending actuator is changed slightly by varying the control voltage.

A device with a membrane comprising a support, a membrane made of a polymer material suspended on said support and at least one actuating module arranged opposite a face of the membrane and separate from said membrane, said actuating module comprising at least one actuator comprising at least one piezoelectric material and a beam connected to the support and separate from the membrane, the piezoelectric material being connected to the beam, such that, when a difference in electric potential is applied to the piezoelectric material, a bimetal effect appears between the piezoelectric material and the beam deforming the beam in the direction of the membrane, causing the deformation of the membrane, said device also comprising at least one electrostatic actuator configured for compressing at least one part of the membrane on the at least one part of the actuating module.

A multi-layer microactuator for a hard disk drive suspension includes a piezoelectric (PZT) layer, a constraining layer, a lower electrode layer, a middle electrode layer, and an upper electrode layer. The lower electrode layer is on a bottom surface of the PZT layer and includes a first lower electrode island, a second lower electrode island, and a third lower electrode island. The second lower electrode island includes a finger extending from a main body portion towards a first end of the PZT layer. The middle electrode layer is disposed between a top surface of the PZT layer and a bottom surface of the constraining layer. The middle electrode layer including a first middle electrode island and a second middle electrode island, the second middle electrode island including a finger extending from a main body portion towards the first end of the PZT layer.

An optical scanning device includes: a mirror that has an optical reflection surface; a mirror support unit configured to support the mirror; a pair of drive beams arranged on both sides of the mirror support unit and connected such that the mirror support unit is swingable; a drive source provided on the drive beams and configured to swing the mirror support unit, the drive source including a stack structure of a plurality of piezoelectric thin films; and a piezoelectric sensor formed on a connection beam connected to the drive source or the drive beams, a number of piezoelectric thin films included in the piezoelectric sensor being less than a number of the piezoelectric thin films included in the drive source.

A piezoelectric element includes: a piezoelectric body; and a vibrating plate including single crystal silicon having anisotropy having orientation with a relatively high Young's modulus and orientation with a relatively low Young's modulus (hereinafter, referred to as low Young's modulus orientation) as a vibrating material, in which the piezoelectric body and the vibrating plate are laminated on each other so that the low Young's modulus orientation is in a direction along a high expansion and contraction direction among a direction where a degree of expansion and contraction caused according to a support structure of the piezoelectric body is relatively high (hereinafter, referred to as high expansion and contraction direction) and a direction where a degree thereof is relatively low.

A multi-layer microactuator for a hard disk drive suspension includes a piezoelectric (PZT) layer, a constraining layer, a lower electrode layer, a middle electrode layer, and an upper electrode layer. The lower electrode layer is on a bottom surface of the PZT layer and includes a first lower electrode island, a second lower electrode island, and a third lower electrode island. The second lower electrode island includes a finger extending from a main body portion towards a first end of the PZT layer. The middle electrode layer is disposed between a top surface of the PZT layer and a bottom surface of the constraining layer. The middle electrode layer including a first middle electrode island and a second middle electrode island, the second middle electrode island including a finger extending from a main body portion towards the first end of the PZT layer.

There is provided a control method for a piezoelectric driving device including a vibrating body including a piezoelectric element for driving and configured to vibrate when a driving signal is applied to the piezoelectric element for driving, a section to be driven that is driven by the vibration of the vibrating body, and a driving-signal generating section configured to generate the driving signal using a pulse signal generated based on a target pulse duty ratio. When the target pulse duty ratio is smaller than a predetermined value, the driving signal generated by the driving-signal generating section is an intermittently generated periodic signal.

A transducer (140) having a mechanical impedance over an operative frequency range and having a desired power coupling (145) to a load over the operative frequency range comprises a piezoelectric device (141) having a frequency distribution of modes in the operative frequency range; and an overmould (143). The overmould (143) is arranged to surround at least part of the piezoelectric device (141); and the parameters of the overmould (143) are selected to provide a required impedance matching between the mechanical impedance of the transducer (140) and the mechanical impedance of the load. An alternative transducer comprises a mounting means for holding a discrete portion of at least a part of the periphery of the piezoelectric device wherein the parameters of the mounting means are selected to provide a required boundary condition for the periphery of the piezoelectric device whereby the desired power coupling between the transducer and the load is provided.

An optical scanning device includes an optical scanner including a mirror that includes a light reflection surface, a driving source that causes the mirror to rotate around a rotation axis passing through the center of the light reflection surface in response to a driving signal, and a piezoelectric sensor that outputs a sensor signal corresponding to a rotational angle of the mirror around the rotation axis; and an impedance conversion circuit that receives the sensor signal from the piezoelectric sensor, performs impedance conversion on the received sensor signal, and outputs the impedance-converted sensor signal.