A vibration drive device that is capable of preventing instability when the speed control is switched between frequency control and pulse width control includes a controller that controls driving of a vibration actuator by applying an alternating voltage to an electromechanical energy conversion element. A switching pulse is generated by switching a DC voltage. A maximum duty ratio of the switching pulse is determined based on a driving condition of the vibration actuator. The driving of the vibration actuator is controlled by switching between frequency control and pulse width control. A gain for frequency control and a gain for pulse width control are set according to the maximum duty ratio so as to prevent electric power or electric current from exceeding an electric power limit or an electric current limit set in advance.

The present invention concerns an ultrasonic vibration device having a sonotrode and a converter, wherein the converter has a piezoelectric actuator for converting an electrical alternating voltage into a mechanical vibration, wherein there is provided a first piezoelectric sensor element which outputs a first measurement signal which varies in dependence on the vibration amplitude of the mechanical vibration. To provide an ultrasonic vibration device which allows measurement of at least one intensive state variable like for example the temperature or the ageing state of the piezoelectric actuator it is proposed according to the invention that there is provided a second piezoelectric sensor element which outputs a second measurement signal which varies in dependence on the vibration amplitude of the mechanical vibration, wherein the second piezoelectric sensor element differs in a physical property from the first piezoelectric sensor element.

The invention relates to an annular or hollow cylindrical ultrasonic actuator, on the end faces of which are arranged n≥2 friction elements, and on the outer peripheral surface of which are arranged 2 n excitation electrodes, spaced apart from one another in each case by a separating gap, each of the friction elements being arranged in the region of a separating gap, wherein, between friction elements that are adjacent with respect to the periphery of the ultrasonic actuator and are located on different end faces, two excitation electrodes are arranged such that, when the ultrasonic actuator is electrically excited, the friction elements of both end faces simultaneously perform a movement which is suitable for driving an element to be driven to rotate in the same direction. The invention further relates to an ultrasonic motor having an ultrasonic actuator of this kind and having a holding device in which the ultrasonic actuator is inserted.

An inertial piezoelectric actuator driven by symmetrical sawtooth wave is symmetrical in structure and includes a seat, a slider, a piezoelectric stack and an elliptical ring. A pair of leaf-shaped flexible beams are arranged at a front end of a base, and a guide rail is connected between the pair of leaf-shaped flexible beams. The slider is placed on the guide rail. The piezoelectric stack is arranged in the elliptical ring with an interference fit. A front end of the elliptical ring is in contact with the guide rail, and a pre-stressed contact force between the elliptical ring and the guide rail is controlled by adjusting a screw at a rear end of the elliptical ring. A method for method for actuating bi-directional motion of the inertial piezoelectric actuator is further provided.

Provided are a flexible body and a method for controlling the flexible body to deform. The flexible body comprises one or more flexible units, wherein each of the flexible units comprises: a first electrode, a second electrode, an electroactive polymer layer, and a thin film transistor, wherein a source electrode or a drain electrode of the thin film transistor is electrically connected to the second electrode. The first electrode and the second electrode are configured to provide an electric field acting on the electroactive polymer layer, and the electroactive polymer layer is configured to deform in response to the electric field provided by the first electrode and the second electrode.

Methods, systems, and computer readable media for control of slip-stick stages using P and PI sawtooth modulated inputs.

The disclosure generally relates to wireless sensing nodes, energy harvesting, and energy charging. The disclosure also generally relates to reporting data gathered by the wireless sensing nodes to one or more network services.

An ultrasonic motor, is disclosed having an ultrasonic actuator in the form of a rectangular piezo-electric plate, which has two generators for acoustic standing waves and on which at least two friction elements are arranged, an element to be driven, and an electric excitation device. The piezoelectric plate of the actuator is divided into two pairs of diagonally oppositely disposed sections by two virtual planes which extend perpendicularly to each other and which extend through the center line of the main surfaces of the actuator, wherein each of the generators includes two parts which can be operated in an antiphase manner and each of which is arranged in a diagonal section of the piezoelectric plate, and the friction elements are arranged on one or two end faces of the piezoelectric plate.

Method for producing an integrated magnetic device with variable inductance, comprising: a) making of a piezoelectric element on a first substrate; b) making of a first electrically conductive element on a face of the piezoelectric element, and fastening of the ends of the piezoelectric element to a second substrate such that the piezoelectric element is arranged facing a cavity formed between the second substrate and the piezoelectric element, the first electrically conductive element being arranged in and/or against the second substrate or against the piezoelectric element; c) removing of the first substrate; d) making of a second electrically conductive element on another face of the piezoelectric element; and further comprising the making of an electrical and/or magnetic coupling of the first and second electrically conductive elements, and the making of a magnetic element arranged against and/or in the piezoelectric element and between the electrically conductive elements.

An ultrasonic motor and method are disclosed with an element to be driven and a plate-shaped ultrasonic actuator made of polarized electromechanical material with at least two friction elements arranged on one of its side. The ultrasonic actuator can include at least two generators for acoustic standing waves and each of the generators can include two cooperating and spaced sub-generators, and one respective sub-generator of a generator is located between the sub-generators of an adjacent generator, and the sub-generators of one generator are arranged in mirror image to the sub-generators of an adjacent generator. A polarization direction of the electromechanical material of one of the two sub-generators of one generator differs from the polarization direction of the electromechanical material of the other sub-generator of the same generator.