Topic
Actuator
About: Actuator is a research topic. Over the lifetime, 66219 publications have been published within this topic receiving 689957 citations.
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Papers
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10 Dec 2002TL;DR: In this paper, an apparatus and a method for performing surgery on a patient is described, which includes an input device, at least one hydraulic amplifier, and an actuator operably attached to the hydraulic amplifier.
Abstract: The invention provides an apparatus and method for performing surgery on a patient. The surgical apparatus includes an input device, at least one hydraulic amplifier operably attached to the input device, and an actuator operably attached to the hydraulic amplifier. Input to the input device is hydraulically modulated via the hydraulic amplifier to manipulate the actuator. The surgical method includes receiving a mechanical input for an action. The mechanical input is hydraulically modulated. The action is controlled based on the hydraulically modulated input.
692 citations
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30 Sep 2005TL;DR: In this paper, a grasping device is provided having a shaft with an end effector having opposed jaws coupled to the shaft, and an electrically expandable and contractible actuator such as an electroactive polymer actuator can be used to actuate the end-effector to open and close the opposed jaws to grasp tissue or other objects.
Abstract: Methods and devices are provided for actuating and/or articulating a grasping device. In one exemplary embodiment, a grasping device is provided having a shaft with an end effector having opposed jaws coupled to the shaft. An electrically expandable and contractible actuator, such as an electroactive polymer actuator, can be used to actuate the end effector to open and close the opposed jaws to grasp tissue or other objects. In another embodiment, an electroactive polymer actuator can be used to pivotally or angularly adjust a position of the end effector relative to the shaft by delivering energy to the electroactive polymer actuator.
691 citations
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TL;DR: The results show that the tracking control performance is greatly improved by augmenting the feedback loop with a model of hysteresis in the feedforward loop.
Abstract: The tracking control accuracy of piezoceramic actuators is limited due to their inherent hysteresis nonlinearity. This paper presents a computer-based tracking control approach for a piezoceramic actuator based on incorporating a feedforward loop with a PID (proportional-integral-derivative) feedback controller. The hysteresis nonlinearity of the piezoceramic actuator is modeled in the feedforward loop by using the classical Preisach model. Experiments were performed on a stacked piezoceramic actuator for tracking sinusoidal waveforms with signal frequencies ranging from 0.1-20 Hz. A comparison was made between a feedforward control scheme, a regular PID feedback control scheme, and a PID feedback control scheme with hysteresis modeling in the feedforward loop. The results show that the tracking control performance is greatly improved by augmenting the feedback loop with a model of hysteresis in the feedforward loop. The maximum error in tracking a sinusoidal waveform is about half that obtained using a regular PID controller.
681 citations
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TL;DR: In this article, a review of the developments in dielectric elastomer actuator technology for several applications is presented, highlighting some of its advantages over existing actuator technologies, identifying some of the challenges associated with its development, and examining the main focus of research within this field.
Abstract: This paper reviews the developments in dielectric elastomer actuator technology for several applications. Dielectric elastomers are a variety of electroactive polymer that deform due to the electrostatic interaction between two electrodes with opposite electric charge. Dielectric elastomers have been subject of much interest and research over the past decade. In earlier years, much of the focus was on actuator configurations, and in more recent years the focus has turned to investigating material properties that may enhance actuator performance. This review outlines the operating principle and actuation mechanisms behind this actuator technology, highlights some of its advantages over existing actuator technologies, identifies some of the challenges associated with its development, and examines the main focus of research within this field, including some of the potential applications of such an actuator technology.
677 citations
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TL;DR: In this article, a water-responsive polymer film was developed that can exchange water with the environment to induce film expansion and contraction, resulting in rapid and continuous locomotion, which can generate contractile stress up to 27 megapascals, lift objects 380 times heavier than itself, and transport cargo 10 times more than itself.
Abstract: Here we describe the development of a water-responsive polymer film. Combining both a rigid matrix (polypyrrole) and a dynamic network (polyol-borate), strong and flexible polymer films were developed that can exchange water with the environment to induce film expansion and contraction, resulting in rapid and continuous locomotion. The film actuator can generate contractile stress up to 27 megapascals, lift objects 380 times heavier than itself, and transport cargo 10 times heavier than itself. We have assembled a generator by associating this actuator with a piezoelectric element. Driven by water gradients, this generator outputs alternating electricity at ~0.3 hertz, with a peak voltage of ~1.0 volt. The electrical energy is stored in capacitors that could power micro- and nanoelectronic devices.
671 citations