It consists of a motor controller, high frequency power source, drive electronics and a linear actuator. 
Soft, pneumatic actuators that buckle when interior pressure is less than exterior provide a new mechanism of actuation. The adhesive between layers sets at a high temperature and as the actuator cools, the metal layers shrink more than the PZT. In particular, for agility enhancement at high angle of attack and low dynamic pressure, structural integration characteristics such as hinge moments, effective actuator stiffness, and airframe/control surface damping can have a significant effect on stability predictions. The actuation characteristic of suggested multilayered actuator using ionic liquid gel is simulated by computer. Selection of the optimum actuator configuration is discussed for specific application which require a tradeoff study that considers all the relevant factors: available energy sources, load capacity, stroke, speed of response, leakage limitations, environmental conditions, chemical compatibility, storage life and conditions, size, weight, and cost. To predict the actuation displacement of the LIPCA with curvature, a finite element analysis method using the proposed piezo-actuation model is introduced. True Low-Power Self-Locking Soft Actuators. 285 microns at 150 V at room temperature and > 100 microns at 77K under driving of 150 V should be expected. PMID:25835386.
Multiple GB idlers provide roller bearing strength sufficient to support efficient, rolling friction movement, even in the presence of large, resisting forces. Minor adjustments in duct flow velocity, flap length, and blowing nozzle geometry were incorporated to provide airplane characteristics that minimize takeoff gross weight and achieve sideline noise objectives for an advanced commercial STOL airplane. Piezo actuators, such as Amplified Piezo Actuators or Parallel Pre-stressed Actuators, initially designed under CNES contracts, shall find their first space flight applications in optics on the PHARAO Laser bench: fine pointing of the laser beams, laser cavity tuning. There is also a tremendous potential in the thermomechanical treatment of the material and in the design of the actuator. Providing such devices with biomimetic qualities, for example, sensing different external stimuli, adds even more complexity to the task. The actuator in this version would generate a force of 1 N and a stroke of 10 m at an applied potential of 150 V. The actuation force would be, Thermal expansion as a precision actuator, Miller, Chris; Montgomery, David; Black, Martin; Schnetler, Hermine. 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. We used the microgrippers to perform diverse functions, such as picking up a bead on a substrate and the removal of cells from tissue embedded at the end of a capillary (an in vitro biopsy). The measurements included the displacement, impedance, capacitance and leakage current and the analysis of the experimental results will be presented. The maximum strain of the composite showed an exponential dependence on the Ms. This paper describes new anisotropic actuators that can be used to improve the bandwidth of the control system. Even though 2-D simulation results in a 25% underestimation of pressure drop in the pump, with respect to 3-D simulation, it results in reducing the computational time of each solution by more than 40 times.
The actuator consists of a working chamber with metallic electrodes and supplying channels filled with an electrolyte. This paper will discuss: the potential applications of the technology; overview of the as built actuator design; discuss problems that were uncovered during the development testing; review test data and evaluate weaknesses of the design; and discuss areas for improvement for future work. The complete first order velocity slip boundary condition, including the thermal creep effects due to the axial temperature gradient and the effect of the wall curvature, and the temperature jump boundary condition are applied. This paper examines photo-actuation-actuation induced by, and controlled with light-through a review of the sun-tracking functions of the Cornish Mallow. The actuator is driven by a SMA -NiTi as a primary active element, and it requires energy on the order of 20 Ws(J) per cycle. These characteristics are desirable in many applications including legged robots, exoskeletons for human performance amplification, robotic arms, haptic interfaces, and adaptive suspensions.
The stressed membrane can be electrostatically switched between a pair of mechanical states having mirror-image symmetry, with the MEM actuator remaining in a quiescent state after a programming voltage is removed. A single force transducer is positioned at a point between a mount for the motor and an output of the actuator. This work is the first stage prototype of a vehicle that will consist of many actuated body segments. Based on the results, the piezoelectric actuator was implemented, and its performance was verified through a cadaveric experiment. Here, we show that actuating fibres that respond to solvent and vapour stimuli can be created through the hierarchical and helical assembly of aligned carbon nanotubes. These factors are interrelated with overall control-system design evaluations that are beyond the scope of this monograph; however, literature references are cited for a detailed review of the general considerations. The actuator has a steady state force output of approximately 2.75 N from approximately 2 Hz to well beyond 1000 Hz. In this paper, we present a thin-film out-of-plane electrostatic actuator for a flexible printed circuit board (FPCB) that can be fabricated with a single step of the conventional manufacturing process. In some embodiments the angle may be varied around a pivot axis in one plane and in some embodiments the angle may be varied around two pivot axes in two orthogonal planes. The actuator housing can be configured and produced using cost-effective methods such as injection molding, or alternatively, its components can be mounted directly on a small circuit board. In this work, a pneumatic actuator is modeled as an elastic element with controllable stiffness and equilibrium point, both of which are functions of air masses in the two chambers. Actuators, employed in acoustic loudspeakers, operate liquid rocket engine valves by replacing light paper cones with flexible metal diaphragms. Upon reheating the material to a temperature above Tg, the material will return to its original shape. Upon changing the environmental humidity, the actuators can respond by the deformation for shielding and report the humidity change in a visual manner, which has been demonstrated by a tweezer and a curtain. Systematic test results indicate that the displacement resolution of the unconventional inchworm actuator reaches 0.038m, and the maximum driving force and velocity are 42N, 14.8mm/s, respectively. Results show that the actuator shows electrostriction-like symmetric bipolar actuation behavior with the repeatable actuation strain of 0.3% under 2kV mm1. Torsion-based ferromagnetic actuators have been fabricated and tested with 110-nm-wide, and 50-rim-thick magnetic elements. Alneamy, A. M.; Khater, M. E.; Al-Ghamdi, M. S.; Park, S.; Heppler, G. R.; Abdel-Rahman, E. M. This paper investigates the performance of cantilever-type micro-mirrors under electromagnetic, electrostatic and dual actuation. This information can be used to determine the 'best' actuator for a given purpose.
Second, to achieve the optimal shape control effect, the position of the actuators and the drive voltages are all determined using a genetic algorithm. Separate actuators and sensors are often combined into one composite device when proprioception (self-sensing) is required. In this paper, we demonstrate a novel microfluidic platform based on an on-chip micropump for mechanical cell disruption and sample transport. Sealing these types of miniature actuators at operating pressures requires obtaining very fine surface finishes which is difficult and costly. Also, its possibility for remotely microwave-driven paper actuator is demonstrated. BAFCO identified four suppliers that manufactured actuator components that met the rigorous testing standards imposed by the Space Agency and then modified these components for application on the rocket test stands. Herein two capstans are mounted on a shaft which is supported in a framework. [, In this study, in order to determine the sensitivity of the grid size to the obtained results, seven different sizes with a total number of cells ranging from approximately 2 10, This section presents the behavior of a passive-valve piezoelectric micro-pump during the operation under different conditions. [, Accoto, D.; Nedelcu, O.; Carrozza, M.; Dario, P. Theoretical analysis and experimental testing of a miniature piezoelectric pump. The actuator can be used as a driving engine for microfluidics. The actuator consists of actuation unit (PZT stack pump), fluid control unit (ERFs valve), and execution unit (hydraulic actuator). Portable syringe drivers are commonly used to deliver continuous subcutaneous infusions in palliative care situations. (Inventor); Kacher, Daniel F. (Inventor); Weiss, Peter (Inventor). The test plan (CTP-0071) outlined a two-phase test program designed to answer questions about the fracture criticality of the redesigned solid rocket motor (RSRM) nozzle actuator bracket. The actuating forces produced by dielectric elastomer actuators depend on the number of layers, the position and the actuation voltage of dielectric elastomer actuators. The use of shape memory alloys in actuators allows the development of robust, simple and lightweight elements for application in a multitude of different industries.
This work describes how this force limit of DEAP membrane actuators can be pushed to the high double-digit Newton range and beyond. Han, J Y; Rahmanian, O D; Kendall, E L; Fleming, N; DeVoe, D L. The fabrication of on-chip displacement pumps integrated into thermoplastic chips is explored as a simple and low cost method for achieving precise and programmable flow control for disposable microfluidic systems. Shape-Memory-Alloy Actuator For Flight Controls. Sea animals such as leptocephali develop tissues and organs composed of active transparent hydrogels to achieve agile motions and natural camouflage in water. Primary fibres consisting of helical assemblies of multiwalled carbon nanotubes are twisted together to form the helical actuating fibres. A reliable method of sample introduction is presented for on-line gas chromatography with a special application to in-situ field portable atmospheric sampling instruments. Mohammadi, F.; Kholkin, A. L.; Jadidian, B.; Safari, A. These actuators are of a novel configuration and are unique in their requirement to function while exposed to re-entry conditions. By using templates, microchannel structures are replicated onto the surface of two highly elastic polymers, polyvinylidene fluoride (PVDF) and polyvinyl alcohol, to induce chiral coiling upon exposure to acetone vapors. A 50l cell sample can be effectively lysed through on-chip multi-disruption in 36s without introducing any chemical agent and suffering from clogging by cellular debris. With the use of the attack angle and the length of the valves as design parameters, the studied design shows promising results. The actuator has the flexibility of being designed for both linear and rotary motion. This paper presents a procedure for modeling structures containing piezoelectric actuators using MSCMASTRAN and MATLAB. Prior SMA actuators typically include polymer housings or shells, steel or aluminum stages, and polymer pads between successive stages of displacement-multiplication assemblies.
Disposable Fluidic Actuators for Miniature In-Vivo Surgical Robotics, Fusion of robotics and minimally invasive surgery (MIS) has created new opportunities to develop diagnostic and therapeutic tools. A complementary theoretical analysis identifies critical parameters for nanotube nanoballoon actuation. Guangzhou Ascend Precision Machinery Co.,Ltd. In the quiescent environment of a Faraday cage the velocity flow field is recorded using particle image velocimetry. The actuator patch is able to generate a local deformation of the surface of the vibrating structure so as to introduce an equivalent damping that dissipates the kinetic energy associated to the vibration. The disadvantages of the PLZT-based actuators are that (1) it is difficult to shape the PLZT ceramics, which are hard and brittle; (2) for actuation, it is necessary to use ultraviolet light (wavelengths < 380 nm), which must be generated by use of high-power, high-pressure arc lamps or lasers; (3) it is difficult to deliver sufficient ultraviolet light through conventional optical fibers because of significant losses in the fibers; (4) the response times of the PLZT actuators are of the order of several seconds unacceptably long for typical applications; and (5) the maximum mechanical displacements of the PLZT-based actuators are limited to those characterized by low strains beyond which PLZT ceramics disintegrate because of their brittleness. PMN-PT single crystal-based multilayer stack actuators and multilayer stack-based flextensional actuators have exhibited high stroke and high displacement-voltage ratios. This has restricted their use to on-off actuators where cycle times of approximately one minute is acceptable. The vane actuator met the requirements given for the ANCF, although in practice the performance of the system was limited by the constraints of the power amplifiers and the presence of control spillover. For a fixed momentum coefficient, decreasing the aspect ratio to 1 produced weaker vortices while increasing the aspect ratio to 4 reduced coverage area. This paper investigates feed-forward control of a dielectric elastomer actuator by using a nonlinear dynamic model. Lu, Chao; Yang, Ying; Wang, Jian; Fu, Ruoping; Zhao, Xinxin; Zhao, Lei; Ming, Yue; Hu, Ying; Lin, Hongzhen; Tao, Xiaoming; Li, Yuliang; Chen, Wei.
Electromagnetic pump pushes liquid lithium against ends of control rods, forcing them out of or into nuclear reactor.
A Reduced-Order Model For Zero-Mass Synthetic Jet Actuators. The Jet Propulsion Laboratory reliability studies of NASA robotic spacecraft have shown that mechanical hardware/mechanism failures are more frequent and more likely to significantly affect mission success than are electronic failures. The composition of Researchers in the field of electroactive polymers (EAP) investigated methods of using these materials to form full screen displays. Feng, Yuan; Zhu, Mo; Qiu, Suhao; Shen, Ping; Ma, Shengyuan; Zhao, Xuefeng; Hu, Chun-Hong; Guo, Liang. There are significant developments underway in new types of actuators for power plant active components. Paper Actuators Made with Cellulose and Hybrid Materials, Kim, Jaehwan; Yun, Sungryul; Mahadeva, Suresha K.; Yun, Kiju; Yang, Sang Yeol; Maniruzzaman, Mohammad, Recently, cellulose has been re-discovered as a smart material that can be used as sensor and actuator materials, which is termed electro-active paper (EAPap). These actuators are small, seal-less, easy to fabricate, disposable, and inexpensive, thus ideal for single-use in-vivo applications. The utilization of piezoelectric actuators in controlling the static deformation and shape of flexible beams is examined.
The governing equations should include fluid flow, elastic behavior of solids, and piezoelectric effect of the material. An electrical energy source coupled to the cylindrical actuators applies actuation energy thereto to generate the telescopic movement. Based on the FEM results, the first generation diaphragm actuator system was assembled and its static and dynamic performance was experimentally evaluated. N. Agrawal Naval Postgraduate School, Monterey, CA, 93943, agrawal, Fe3O4Silicone Mixture as Flexible Actuator, In this study, we introduce Fe3O4-silicone flexible composite actuators fabricated by combining silicone and iron oxide particles. Usually, MEMS actuators cannot be fabricated directly on the side walls of silicon wafers, yet the geometry of this actuator necessitates such fabrication. Finally, bipolar field testing was conducted on the POP BT based actuator. High-Force Dielectric Electroactive Polymer (DEAP) membrane actuator, Hau, Steffen; York, Alexander; Seelecke, Stefan. Given that the pseudo-three-layer actuator structure is compatible with both the parallel-plate actuators and these two types of repulsive actuators, a 19-element two-layer repulsive actuated deformable mirror is operated in pseudo-three-layer electrical connection mode. It combines the advantages of two-layer and three-layer repulsive actuators, i.e., fabrication requirements and fill factor. PMID:27713542. At higher rates of motion, EA's are operating as constant power devices. As such, this new actuator provides a unique bi-directional actuation capability, and, thus, has a potential to significantly simplify the design of a muscle actuator-powered robotic system. Shape Memory Actuated Normally Open Permanent Isolation Valve, Ramspacher, Daniel J. A methodology was developed to make the open-celled porous TiNi foams as a tube with integrated hexagonal ends, which then becomes a torsional actuator with fast response times. Depending on the volume envelope criteria, the actuator can be configured for scaling its volume down to 4x2x1 cu cm. Sequential actuation of the four-chamber device using reduced pressure moves the central rod cyclically in an approximately square path. Natural fibres actuators for smart bio-inspired hygromorph biocomposites, Le Duigou, Antoine; Requile, Samuel; Beaugrand, Johnny; Scarpa, Fabrizio; Castro, Mickael. The present invention is a vertical piezoelectric hybrid zero-net mass-flux actuator, in which all the walls of the chamber are electrically controlled synergistically to reduce or enlarge the volume of the synthetic jet actuator chamber in three dimensions simultaneously and to reduce or enlarge the diameter of orifice of the synthetic jet actuator simultaneously with the reduction or enlargement of the volume of the chamber. In particular, the issues associated with integration of these devices into MEMS at the production level are highly significant and they have perhaps received less attention in the mainstream than they deserve. 35Hz shape memory alloy actuator with bending-twisting mode, Shape Memory Alloy (SMA) materials are widely used as an actuating source for bending actuators due to their high power density. The invention provides an elastic actuator consisting of a motor and a motor drive transmission connected at an output of the motor. The piezoelectric actuation has a similar effect. Also, a bend-twist coupled motion using an anisotropic layered reinforcement structure at a speed of 10Hz is also realized. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. Herein, we investigate the characteristic changes in actuation performance by increasing the concentration of iron oxide from 1% to 20%. First, a static model is described that relates internal stresses and strains and external displacements to the thermal pre-stress and applied voltage. It combines the advantages of two-layer and three-layer repulsive actuators, i.e., fabrication requirements and fill factor. To monitor the performance of the actuators driving voltage and current are measured continuously and additionally, the amplitude of the deformations of each actuator is measured sequentially. Finally, a conducting layer of polypyrrole was added by means of electrochemical deposition. However, two drawbacks appear upon the increase in the attack angle. Fluid power in the form of hydraulics or pneumatics has a long history in driving many industrial devices and could be exploited to circumvent these limitations.
Flow reversed for shutdown. Hagen, Jeff; Moore, Landon; Estes, Jay; Layer, Chris. Two different ThRA designs were cycle tested to measure the skip rate. In this article, we have established an analytical model to estimate the quasi-static bending displacement (i.e., angle) of the pneumatic actuators made of two different elastomeric silicones (Elastosil M4601 with a bulk modulus of elasticity of 262kPa and Translucent Soft silicone with a bulk modulus of elasticity of 48kPa-both experimentally determined) and of discrete chambers, partially separated from each other with a gap in between the chambers to increase the magnitude of their bending angle. The actuators were coupled with microwave rectenna and tested to correlate the coupling effect of electromagnetic wave. The vapomechanical coiling is reversible and can be conducted repeatedly over 100 times without apparent fatigue. Verification of a computational cardiovascular system model comparing the hemodynamics of a continuous flow to a synchronous valveless pulsatile flow left ventricular assist device. The real-time fault diagnosis and failure management (FDFM) of current operational and experimental dual tandem aircraft flight control system actuators was investigated.
In order to measure the chloride ion concentration, a measurement system is needed which can detect this concentration for prolonged times reliably. Characterizations of the actuator load, displacement and cyclic properties were conducted using a custom-built spring-biased test set-up. In light of the achievements of the present study, the proposed osmotic actuator holds potential for effective exploitation in bioinspired robotics systems. The results are specialized to a simple form for truss structures composed of nominally identical members. Actuator line model has been widely employed in wind turbine simulations. This work is motivated by the need to reduce landing gear noise for commercial transport aircraft via an effective streamlining created by the actuators. We demonstrate successful actuation of micron-sized silicon-based piezoelectric resonators with resonance frequencies from 36 MHz to 120 MHz, at power levels of nanowatts and distances of about 3 feet, including polarization, distance and power dependence measurements. The non-active areas in the form of elliptical spots that affect the performance of the actuator are identified using scanning electron microscope (SEM) and energy dissipated X-ray (EDX) experiments. Herein, we describe a cross-linked supramolecular approach to prepare tough nanocomposite gel electrolytes from HEMA, BMIMBF4, and TiO2 via self-initiated UV polymerization. Y. W. Xue, T. M. Yu, Y. Y.
This study includes the experimental validation of numerical simulations using the measured flow rates of a micro-pump from the literature and is the first study, which investigates the effect of various parameters on the performance of the introduced piezoelectric micro-pump. This manuscript reviews the state of the art of producing refreshable Braille displays using EAP-based actuators. A visual programming environment is used to integrate the sensors, controller and actuators. 
