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Journal articles on the topic 'Surface actuators'
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1
Jang, Minsu, Jun Sik Kim, Ji-Hun Kim, Do Hyun Bae, Min Jun Kim, Donghee Son, Yong-Tae Kim, Soong Ho Um, Yong Ho Kim, and Jinseok Kim. "Surface-Controlled Molecular Self-Alignment in Polymer Actuators for Flexible Microrobot Applications." Polymers 11, no. 4 (April 23, 2019): 736. http://dx.doi.org/10.3390/polym11040736.
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Polymer actuators are important components in lab-on-a-chip and micromechanical systems because of the inherent properties that result from their large and fast mechanical responses induced by molecular-level deformations (e.g., isomerization). They typically exhibit bending movements via asymmetric contraction or expansion with respect to changes in environmental conditions. To enhance the mechanical properties of actuators, a strain gradient should be introduced by regulating the molecular alignment; however, the miniaturization of polymer actuators for microscale systems has raised concerns regarding the complexity of such molecular control. Herein, a novel method for the fabrication of micro-actuators using a simple molecular self-alignment method is presented. Amphiphilic molecules that consist of azobenzene mesogens were located between the hydrophilic and hydrophobic surfaces, which resulted in a splayed alignment. Thereafter, molecular isomerization on the surface induced a large strain gradient and bending movement of the actuator under ultraviolet-light irradiation. Moreover, the microelectromechanical systems allowed for the variation of the actuator size below the micron scale. The mechanical properties of the fabricated actuators such as the bending direction, maximum angle, and response time were evaluated with respect to their thicknesses and lengths. The derivatives of the polymer actuator microstructure may contribute to the development of novel applications in the micro-robotics field.
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Oliver, A. D., S. R. Vigil, and Y. B. Gianchandani. "Photothermal surface-micromachined actuators." IEEE Transactions on Electron Devices 50, no. 4 (April 2003): 1156–57. http://dx.doi.org/10.1109/ted.2003.812505.
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Shrestha, Milan, Gih-Keong Lau, Anand Asundi, and Zhenbo Lu. "Dielectric Elastomer Actuator-Based Multifunctional Smart Window for Transparency Tuning and Noise Absorption." Actuators 10, no. 1 (January 15, 2021): 16. http://dx.doi.org/10.3390/act10010016.
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Soft actuators are compliant material-based devices capable of producing large deformation upon external stimuli. Dielectric elastomer actuators (DEA) are a type of soft actuator that operates on voltage stimuli. Apart from soft robotics, these actuators can serve many novel applications, for example, tunable optical gratings, lenses, diffusers, smart windows and so on. This article presents our current work on tunable smart windows which can regulate the light transmittance and the sound absorption. This smart window can promote daylighting while maintaining privacy by electrically switching between transparent and opaque. As a tunable optical surface scatters, it turns transparent with smooth surfaces like a flat glass; but it turns ‘opaque’ (translucent) with the micro-rough surface. The surface roughness is varied employing surface micro-wrinkling or unfolding using dielectric elastomer actuation. Moreover, this smart window is equipped with another layer of transparent micro-perforated dielectric elastomer actuator (DEA), which acts like Helmholtz resonators serving as a tunable and broader sound absorber. It can electrically tune its absorption spectrum to match the noise frequency for maximum acoustic absorption. The membrane tension and perforation size are tuned using DEA activation to tune its acoustic resonant frequency. Such a novel smart window can be made as cheap as glass due to its simple all-solid-state construction. In future, they might be used in smart green buildings and could potentially enhance urban livability.
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Uetsuji, Yasutomo, Hiroyuki Kuramae, Kazuyoshi Tsuchiya, and Hidetoshi Sakamoto. "Development of a New Piezoelectric Actuator with Slits." ISRN Materials Science 2013 (July 25, 2013): 1–9. http://dx.doi.org/10.1155/2013/172054.
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A piezoelectric actuator was developed for fluid pumps in health monitoring systems. We devised a piezoelectric actuator with some slits, which allows the stretching and contracting deformation in in-plane direction and creates large deflection in out-of-plane direction. The static behaviors under uniform electric field have been analyzed by finite element method. And then, the optimum geometry of slits was searched by response surface methodology for unimorph and bimorph actuators to output the largest deflection under various fixed conditions. The computational results indicated that a bimorph actuator with cross-shaped slit under outside-fixed condition has superior performance for fluid pumps. The proposed slit-inserted actuators have been manufactured as an experiment. As a result, it was verified that the developed actuator can amplify the deflection compared with conventional nonslit actuators.
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Hofmann, Viktor, and Jens Twiefel. "Optimization of a Piezoelectric Bending Actuator for a Tactile Virtual Reality Display." Energy Harvesting and Systems 2, no. 3-4 (April 14, 2015): 177–85. http://dx.doi.org/10.1515/ehs-2014-0055.
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Abstract The excitation of mechanoreceptors in the finger with different frequencies and intensities generates a tactile impression. For the experience of a complete surface many distributed sources are needed in the tactile display. For these local stimulations of the finger several piezoelectric bending actuators will be arranged in an array perpendicular to the skin. The challenge in the system design is to transfer high dynamic shear forces to the skin at required frequencies together with a compact display design. In order to estimate the dynamic behavior of the bending actuators a transfer matrix method model based on the Timoshenko beam theory is derived. Beside the outer geometric values, the layered structure of the actuator is included in the model. In addition the influence of the load on the actuator’s tip in lateral and in normal direction as well as on the rotational degree of freedom is taken into account. Using the analytical approach, a parametric study is carried out to find an optimized actuator design for the display. For the validation, the modeled beam is compared with experimental data.
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He, Hong Lin, and Jun Ping Wang. "Effect of Anisotropic Membrane Surface Modification of Nafion Based Ionic Polymer-Metal Composites." Advanced Materials Research 311-313 (August 2011): 2000–2004. http://dx.doi.org/10.4028/www.scientific.net/amr.311-313.2000.
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In order to enhance the electromechanical characteristics of IPMCs actuators under low voltage, a set of anisotropic membrane surface modification techniques, including roughness along, roughness across and roughness across both directions, is proposed in this paper. Three groups of IPMCs samples based on corresponding roughness direction have been prepared to validate the these surface modification. Experiments have been made to measure the electromechanical characteristics of the samples. The results show that the IPMCs actuator with micro-grooves being across the length of the IPMCs actuator could improve the IPMCs’ tip blocking force and deflection, and it exhibits blocking forces by 10% larger than the conventional IPMCs while its displacement is approximately 8% larger. We can conclude that an appropriate anisotropic surface modification could be an effective method to create a preferred bending force and to enhance the bending margin of IPMCs actuators.
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Yu, Huangchao, and Xiaodong Wang. "Modelling and simulation of surface-bonded piezoelectric actuators with bending effects." Journal of Intelligent Material Systems and Structures 28, no. 4 (July 28, 2016): 507–20. http://dx.doi.org/10.1177/1045389x16649701.
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In the modelling of thin-sheet piezoelectric actuators the effect of bending of the actuator itself is usually ignored. The current paper presents a model of a surface bonded piezoelectric actuator subjected to electric loading, which contains both the axial and bending deformations. The static electromechanical response of the actuator is studied under different mechanical and geometrical conditions to evaluate the effect of bending. An imperfectly bonded interface is proposed to simulate debonding and to study its effect on the actuation process. The problem is formulated as integral equations in terms of the interfacial shear and normal stresses, which are solved by using Chebyshev polynomials. Based on the solution, the effect of bending of the actuator upon load transfer is analysed. Illustrative examples are presented to show the effect of the material property, the geometry and the interfacial debonding on the response of the integrated structure.
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Park, Minjeong, Joohee Kim, Hanjung Song, Seonpil Kim, and Minhyon Jeon. "Fast and Stable Ionic Electroactive Polymer Actuators with PEDOT:PSS/(Graphene–Ag-Nanowires) Nanocomposite Electrodes." Sensors 18, no. 9 (September 16, 2018): 3126. http://dx.doi.org/10.3390/s18093126.
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Ionic electroactive polymer (IEAP) actuators that are driven by electrical stimuli have been widely investigated for use in practical applications. However, conventional electrodes in IEAP actuators have a serious drawback of poor durability under long-term actuation in open air, mainly because of leakage of the inner electrolyte and hydrated cations through surface cracks on the metallic electrodes. To overcome this problem, a top priority is developing new high-performance ionic polymer actuators with graphene electrodes that have superior mechanical, electrical conductivity, and electromechanical properties. However, the task is made difficultby issues such as the low electrical conductivity of graphene (G). The percolation network of silver nanowires (Ag-NWs) is believed to enhance the conductivity of graphene, while poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), which exhibits excellent stability under ambient conditions, is expected to improve the actuation performance of IEAP actuators. In this study, we developed a very fast, stable, and durable IEAP actuator by employing electrodes made of a nanocomposite comprising PEDOT:PSS and graphene–Ag-NWs (P/(G–Ag)). The cost-effective P/(G–Ag) electrodes with high electrical conductivity displayed a smooth surface resulting from the PEDOT:PSS coating, which prevented oxidation of the surface upon exposure to air, and showedstrong bonding between the ionic polymer and the electrode surface. More interestingly, the proposed IEAP actuator based on the P/G–Ag electrode can be used in active biomedical devices, biomimetic robots, wearable electronics, and flexible soft electronics.
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Ruotsalainen, Pasi, Petter Kroneld, Kalervo Nevala, Timo Brander, Tomi Lindroos, and Merja Sippola. "Shape Control of a FRP Airfoil Structure Using SMA-Actuators and Optical Fiber Sensors." Solid State Phenomena 144 (September 2008): 196–201. http://dx.doi.org/10.4028/www.scientific.net/ssp.144.196.
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The aim of this work was to design a control system for the shape memory alloy (SMA) actuator operated airfoil (a cross section of wind turbine blade). Design of SMA control is focused on the reliable operation of the SMA actuators. The actuator should follow the targeted shape accurately and without too much delay. Another objective is to avoid overheating which is the most critical damage to the structure. SMA actuator shape control is in principle possible to do with any position control method, but the specific properties of the SMA actuators, like the hysteresis, the first cycle effect and the long term changes, need to be taken into account. In this work, a wing profile prototype was measured using optical fiber sensors and traditional strain gauges. Also, external laser sensors were used to measure displacements of upper/lower surface and trailing edge. Shape change was obtained by embedding SMA wire actuators into fiber reinforced polymer (FRP) composite structure. SMA actuators were laminated in such way that bending of trailing edge is always downwards. Actuators are activated with Joule heating and the temperature is measured with integrated thermocouples and optical fiber temperature sensors. As a result, this work gave information about the usability of optical fibers sensors in active FRP composite structures. Measurements also give information about the efficiency of SMA actuators in shape control of relatively stiff FRP structures.
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Kedzierski, Jakub, and Eric Holihan. "Linear and rotational microhydraulic actuators driven by electrowetting." Science Robotics 3, no. 22 (September 19, 2018): eaat5643. http://dx.doi.org/10.1126/scirobotics.aat5643.
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Microhydraulic actuators offer a new way to convert electrical power to mechanical power on a microscale with an unmatched combination of power density and efficiency. Actuators work by combining surface tension force contributions from a large number of droplets distorted by electrowetting electrodes. This paper reports on the behavior of microgram-scale linear and rotational microhydraulic actuators with output force/weight ratios of 5500, cycle frequencies of 4 kilohertz, <1-micrometer movement precision, and accelerations of 3 kilometers/second2. The power density and the efficiency of the actuators were characterized by simultaneously measuring the mechanical work performed and the electrical power applied. Maximum output power density was 0.93 kilowatt/kilogram, comparable with the best electric motors. At maximum power, the actuator was 60% efficient, but efficiencies were as high as 83% at lower power. Rotational actuators demonstrated a torque density of 79 newton meters/kilogram, substantially more than electric motors of comparable diameter. Scaling the droplet pitch from 100 to 48 micrometers increased power density from 0.27 to 0.93 kilowatt/kilogram, validating the quadratic scaling of actuator power.
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Galley, Knopf, and Kashkoush. "Pneumatic Hyperelastic Actuators for Grasping Curved Organic Objects." Actuators 8, no. 4 (November 5, 2019): 76. http://dx.doi.org/10.3390/act8040076.
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Soft robotic grippers often incorporate pneumatically-driven actuators that can elastically deform to grasp delicate, curved organic objects with minimal surface damage. The complexity of the actuator geometry and the nonlinear stress–strain behavior of the stretchable material during inflation make it difficult to predict actuator performance prior to prototype fabrication. In this work, a scalable modular elastic air-driven actuator made from polydimethylsiloxane (PDMS) is developed for a mechanically compliant robotic gripper that grasps individual horticultural plants and fungi during automated harvesting. The key geometric design parameters include the expandable surface area and wall thickness of the deformable structure used to make contact with the target object. The impact of these parameters on actuator displacement is initially explored through simulation using the Mooney–Rivlin model of hyperelastic materials. In addition, several actuator prototypes with varying expandable wall thicknesses are fabricated using a multistep soft-lithography molding process and are inserted in a closed ring assembly for experimental testing. The gripper performance is evaluated in terms of contact force, contact area with the target, and maximum payload before slippage. The viability of the gripper with PDMS actuators for horticultural harvesting applications is illustrated by gently grasping a variety of mushroom caps.
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Bi, Zhuming, Bongsu Kang, and Puren Ouyang. "Fatigue Analysis of Actuators with Teflon Impregnated Coating—Challenges in Numerical Simulation." Actuators 10, no. 4 (April 18, 2021): 82. http://dx.doi.org/10.3390/act10040082.
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Actuators are essential components for motion in machines, and warranty service lives are basic specifications of actuators. However, fatigue damage or wear of actuators are very complex and related to many design factors, such as materials properties, surface conditions, loads, and operating temperature. Actuator manufacturers still rely heavily on physical experiments to determine the fatigue lives of actuators. This paper investigates the state-of-the-art of using numerical simulations for fatigue analysis of mechanical actuators. Failure criteria of machine elements are discussed extensively; existing works on using finite element methods for machine element designs are examined to (1) explore the feasibility of using a numerical simulation for fatigue analysis and (2) discuss the technical challenges in practice. Moreover, a systematic procedure is suggested to predict fatigue lives of mechanical actuators with Teflon impregnated hard coatings. A virtual fatigue analysis allows for optimizing a mechanical structure, reducing design verification costs, and shortening the development time of actuators.
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Sato, Saya, Hiroshi Yokoyama, and Akiyoshi Iida. "Control of Flow around an Oscillating Plate for Lift Enhancement by Plasma Actuators." Applied Sciences 9, no. 4 (February 22, 2019): 776. http://dx.doi.org/10.3390/app9040776.
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During insect flight, a feathering motion of the wing’s controls vortex shedding for lift enhancement. In this study, in order to control the flow around a wing flapping with simplified sinusoidal motion, plasma actuators were introduced to simplify the complex feathering motion. In a wind tunnel, a smoke-wire method was enacted to visualize the flow fields around an oscillating plate with an attack angle of 4° in a uniform flow for the baseline and controlled cases. The actuator placed around the leading edge was found to suppress the flow separation on the top surface. Numerical simulations were performed to investigate the control effects on the fluctuating lift, where the control effects by the intermittently driven actuator were also predicted. The actuator installed on the top surface throughout the up-stroke motion was found to suppress vortex shedding from the trailing edge, which resulted in an 11% lift enhancement compared to the baseline case. In regard to the effects of the installation position, it was found that the actuator placed on the top surface was effective, compared to the cases for installation on the bottom surface or both surfaces.
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Johnstone, R. W., and M. Parameswaran. "Modelling surface-micromachined electrothermal actuators." Canadian Journal of Electrical and Computer Engineering 29, no. 3 (July 2004): 193–202. http://dx.doi.org/10.1109/cjece.2004.1532523.
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Zaehringer, Sandy, Maximilian Spornraft, and Norbert Schwesinger. "Piezoelectric Bulk Material for the Fabrication of Membrane Actuators Using Surface Electrodes for Actuation." Applied Mechanics and Materials 404 (September 2013): 682–87. http://dx.doi.org/10.4028/www.scientific.net/amm.404.682.
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Using piezoelectric bulk material for manufacturing membrane actuators offers several advantages. Instead of manufacturing e.g. a silicon membrane and then either depositing a piezoelectric thinfilm actuator or mounting a piezo disc or stack to the silicon membrane, it is possible to use the piezoelectric material itself as membrane. Circular lead zirconate titanate (PZT) discs were adapted to silicon surface micromachining technologies. By depositing interdigitated electrode layouts several actuators were structured on one substrate. Those inderdigitated electrode layouts, when actuated, cause an inhomogeneous electric field distribution and thus cause an inhomogeneous mechanical stress distribution within the PZT-substrate. This forces the PZT to deflect in those actuated areas, without the usually needed passive membrane.
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Lee, Ki-Ho, Jeong-Guon Ih, and Donghyun Jung. "Traveling-wave control of the bending wave in a beam for high quality sound radiation." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, no. 6 (August 1, 2021): 925–28. http://dx.doi.org/10.3397/in-2021-1696.
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The bending wave generated by the actuator exciting a panel can be controlled to be in the traveling wave form void the structural resonances, which deteriorates the radiated sound if the panel is used as a speaker. Although such traveling-wave control method (TCM) yields a wider effective frequency range than the modal control method, the requirement of using many actuators is the practical problem yet. If a beam is employed instead of a plate as a panel speaker, the number of actuators can be reduced despite a smaller radiating surface than a plate. This study adopts three actuators for the beam control using TCM. An actuator excites the beam in the middle position, and the two actuators near the two edges are used to suppress the reflected waves from the boundaries. The control result shows that the driving-point mobility of the primary actuator is converted into that of an infinite beam, which means that the boundaries are changed into anechoic ones and the structural resonances are eliminated. Accordingly, the beam radiates a smooth sound spectrum without sharp peaks and troughs related to the resonant responses. Effects of material and dimension in determining the effective frequency range are also explored.
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Rukhlenko, Ivan D., Syamak Farajikhah, Charles Lilley, Andre Georgis, Maryanne Large, and Simon Fleming. "Performance Optimization of Polymer Fibre Actuators for Soft Robotics." Polymers 12, no. 2 (February 14, 2020): 454. http://dx.doi.org/10.3390/polym12020454.
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Analytical modeling of soft pneumatic actuators constitutes a powerful tool for the systematic design and characterization of these key components of soft robotics. Here, we maximize the quasi-static bending angle of a soft pneumatic actuator by optimizing its cross-section for a fixed positive pressure inside it. We begin by formulating a general theoretical framework for the analytical calculation of the bending angle of pneumatic actuators with arbitrary cross-sections, which is then applied to an actuator made of a circular polymer tube and an asymmetric patch in the shape of a hollow-cylinder sector on its outer surface. It is shown that the maximal bending angle of this actuator can be achieved using a wide range of patches with different optimal dimensions and approximately the same cross-sectional area, which decreases with pressure. We also calculate the optimal dimensions of thin and small patches in thin pneumatic actuators. Our analytical results lead to clear design guidelines, which may prove useful for engineering and optimization of the key components of soft robotics with superior features.
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Zhang, Danqing, Binbin Xiang, Aili Yusup, Na Wang, and Guljaina Kazezkhan. "Fault Tolerance for Active Surface System with Actuator Faults." Advances in Astronomy 2021 (February 26, 2021): 1–12. http://dx.doi.org/10.1155/2021/6675846.
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The QiTai Radio Telescope (QTT) will be equipped with the active surface adjustment system (ASAS) to correct the main reflector deformation caused by environmental loading. In order to guarantee the stability and performance of the active surface system under fault conditions, it is necessary to adopt the fault-tolerant method when actuator faults have occurred. In this paper, a fault control method based on actuator faults weighting is proposed to solve the active surface fault control problem. According to the coordinates of the adjustable points of the panels corresponding to the faulty actuators, a new paraboloid is fitted by a weighted health matrix, and the fitting surface is taken as the target to adjust the surface shape.
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Nall, Christian L., and Pranav A. Bhounsule. "A Miniature 3D Printed On-Off Linear Pneumatic Actuator and Its Demonstration into a Cartoon Character of a Hopping Lamp." Actuators 8, no. 4 (October 17, 2019): 72. http://dx.doi.org/10.3390/act8040072.
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Although 3D printing has been extensively used to create passive machines and mechanisms, 3D printing of actuators is a relatively new concept. 3D printing of actuators allows greater customization, accelerates the design and development, and consequently saves time and money. We present the design and fabrication of a 3D printed, miniature size, double-acting, On-Off type, linear pneumatic actuator. The actuator has an overall length of 8 cm, a bore size of 1.5 cm, and a stroke length of 2.0 cm. The overall weight is 12 gm and it generates a peak output power of 2 W when operating at an input air pressure of 40 psi ( 275 . 79 kPa). This paper demonstrates novel methods to solve the challenges that arise during fabrication that include: (1) chemical post-processing to achieve airtight sealing and a smooth surface finish, (2) strategic placement of a metallic part within 3D printed plastic for higher strength, (3) design of an airtight seal between the cylinder and piston head, (4) chemical bonding of printed parts using adhesive, and (5) use of a lubricant to reduce friction and improve force generation. The power-to-weight ratio of our actuator is comparable to that of high-end commercial actuators of similar size. The utility of the actuator is demonstrated in a series of jumping experiments with the actuator and by incorporating the actuator into a hopping robot inspired by Disney/Pixar Luxo lamp. We conclude that 3D printed pneumatic actuators combine the high power of pneumatics with the low weight of plastics, and structural strength through the selective placement of metal parts, thus offering a promising actuator for robotic applications.
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Zhou, Su-Wei, Chen Liang, and C. A. Rogers. "An Impedance-Based System Modeling Approach for Induced Strain Actuator-Driven Structures." Journal of Vibration and Acoustics 118, no. 3 (July 1, 1996): 323–31. http://dx.doi.org/10.1115/1.2888185.
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This paper presents the theoretical development and experimental verification of a system model of piezoelectric (PZT) patch actuators for induced strain actuation of two-dimensional active structures. The model includes the dynamic interaction between PZT actuators and their host structures. Analytical solutions of the output behavior of the PZT actuators have been developed based upon the actuator input impedance and the mechanical impedance of the host structures. The impedance-based model was then applied to thin plates and thin shells, and to beams. The case studies demonstrate the generality and utility of the impedance modeling approach. A simply-supported thin plate with surface-bonded PZT patches was built and tested so that the ability of the impedance model to accurately predict the dynamic performance of the actuator and the host structure has been verified. When compared with conventional static models, the impedance modeling method offers insight into the dynamic coupling of the integrated PZT/substrate systems.
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Jun-liang, Ding, Wu Yun, and Zhou You-tian. "Discharge characteristic and flow control experiment for pneumatic actuator of dielectric barrier discharge multistage plasma." International Journal of Electrical Engineering & Education 57, no. 1 (December 1, 2018): 41–53. http://dx.doi.org/10.1177/0020720918813815.
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Test and diagnosis of the characteristics of the air flow induced by the pneumatic actuation of the plasma are the important basis for the plasma flow control. In order to well understand the electrical characteristics of the pneumatic actuation of the plasma and the influence of the actuation voltage amplitude and the phase on the induced flow characteristics, the dielectric barrier discharge actuators symmetrically distributed were selected for the experimental research. The experiment result shows that the discharge form of the actuators symmetrically distributed is filamentary discharge, uniformly occurring around the high-voltage electrodes, and this is different from the discharge picture of the actuators asymmetrically distributed; when the voltage applied on the high-voltage electrode near to the actuators has the same amplitude and phase, the induced directional jet flow is vertical to the actuator surface, and the speed is at the order of meter per second; the change of the amplitude or phase of the voltage applied on the high-voltage electrode of the actuator can induce a jet flow towards the upper left or the upper right, but cannot effectively increase the induced airflow velocity.
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Zsurzsan, Gabriel, Akio Yamamoto, Zhe Zhang, Nils A. Andersen, and Michael A. E. Andersen. "Using squeeze-film effect to reduce surface friction in electrostatic actuators." Abstracts of the international conference on advanced mechatronics : toward evolutionary fusion of IT and mechatronics : ICAM 2015.6 (2015): 331–32. http://dx.doi.org/10.1299/jsmeicam.2015.6.331.
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Yan, W. Y., and A. M. Al-Jumaily. "Workpiece Deflection Compensation Using a Two-Dimensional Toolposts." Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics 219, no. 4 (December 1, 2005): 393–400. http://dx.doi.org/10.1243/146441905x9917.
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Considering the workpiece elastic deflection in a turning process, a simulation model that accounts for the radial and tangential vibrations and their abatement using active control is developed. The model is simulated using Simulink in a Matlab environment to assess the possibility of using an active actuator to reduce vibrations in two directions. The results demonstrate the significance of the workpiece elastic deformation and its compensation using active actuators. Actuators that can compensate for the piece deflection and the vibrations due to the surface roughness are speculated upon.
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Zaehringer, Sandy, Julia Purr, and Norbert Schwesinger. "Manipulation of IDT-Actuated Piezoelectric Membrane Actuators by Silicon Clamping." Applied Mechanics and Materials 518 (February 2014): 215–19. http://dx.doi.org/10.4028/www.scientific.net/amm.518.215.
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This paper will introduce a piezoelectric micro membrane actuator with interdigitated (IDT) surface electrodes for polarization and actuation. The thus achieved polarization and generated electric field are highly inhomogeneous and cause therefore also inhomogeneous strain and stress distributions within the piezoelectric material itself. To equalize the strain and stress the material will deform. This deformation can be manipulated due to electrodes design and clamping of the membrane. The most outstanding achievement with this manipulation is the deflection of the membrane towards the actuated surface and not as is common in piezoelectric membrane actuators towards the passive surface of the device.
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Shevtsov, Sergey, Valery Chebanenko, Maria Shevtsova, Evgenia Kirillova, and Evgeny Rozhkov. "On the Directivity of Acoustic Waves Generated by the Angle Beam Wedge Actuator in Thin-Walled Structures." Actuators 8, no. 3 (September 1, 2019): 64. http://dx.doi.org/10.3390/act8030064.
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The paper aims to develop improved acoustic-based structural health monitoring (SHM) and nondestructive evaluation (NDE) techniques, which provide the waves directivity emitted by the angle beam wedge actuators in thin-walled structures made of plastic materials and polymeric composites. Our investigation includes the dispersive analysis of the waves that can be excited in the studied plastic panel. Its results allowed to find two kinds of generated acoustic waves—anti-symmetric Lamb waves (A0) and shear horizontally polarized SH waves (SS0). The bounds of the chosen frequency range for the experimental and numerical studies were accepted as a compromise between the desire to obtain a high defect resolution by generating short waves, their adjustable directivity, and maximum propagation length. The finite element model for the transducer was built by using the results of an actuator structure experimental study. The frequency response functions for the actuator current and oscillation amplitude of the footprint surface demonstrated good agreement. The found eigenfrequencies of the actuator’s structure were used for the numerical and experimental study of the Lamb and SH wave generation and propagation in a thin-walled plastic panel. Our results convincingly demonstrated the satisfactory directivity of the actuated waves at their excitation on the frequencies that corresponded to the natural modes of the actuator oscillation. The authors assume that an efficient use of the proposed technique for other analyzed quasi-isotropic materials and applied actuators can be provided by preliminary research using a similar approach and methods presented in this article.
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Ramegowda, Prakasha Chigahalli, Daisuke Ishihara, Tomoya Niho, and Tomoyoshi Horie. "Performance Evaluation of Numerical Finite Element Coupled Algorithms for Structure–Electric Interaction Analysis of MEMS Piezoelectric Actuator." International Journal of Computational Methods 16, no. 07 (July 26, 2019): 1850106. http://dx.doi.org/10.1142/s0219876218501062.
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This work presents multiphysics numerical analysis of piezoelectric actuators realized using the finite element method (FEM) and their performances to analyze the structure-electric interaction in three-dimensional (3D) piezoelectric continua. Here, we choose the piezoelectric bimorph actuator without the metal shim and with the metal shim as low-frequency problems and a surface acoustic wave device as a high-frequency problem. More attention is given to low-frequency problems because in our application micro air vehicle’s wings are actuated by piezoelectric bimorph actuators at low frequency. We employed the Newmark’s time integration and the central difference time integration to study the dynamic response of piezoelectric actuators. Monolithic coupling, noniterative partitioned coupling and partitioned iterative coupling schemes are presented. In partitioned iterative coupling schemes, the block Jacobi and the block Gauss–Seidel methods are employed. Resonance characteristics are very important in micro-electro-mechanical system (MEMS) applications. Therefore, using our proposed coupled algorithms, the resonance characteristics of bimorph actuator is analyzed. Comparison of the accuracy and computational efficiency of the proposed numerical finite element coupled algorithms have been carried out for 3D structure–electric interaction problems of a piezoelectric actuator. The numerical results obtained by the proposed algorithms are in good agreement with the theoretical solutions.
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Dimitriadis, E. K., C. R. Fuller, and C. A. Rogers. "Piezoelectric Actuators for Distributed Vibration Excitation of Thin Plates." Journal of Vibration and Acoustics 113, no. 1 (January 1, 1991): 100–107. http://dx.doi.org/10.1115/1.2930143.
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The behavior of two dimensional patches of piezoelectric material bonded to the surface of elastic distributed structures and used as vibration actuators is analytically investigated. A static analysis is used to estimate the loads induced by the piezoelectric actuator to the supporting elastic structure. The theory is then applied to develop an approximate dynamic model for the vibration response of a simply supported elastic rectangular plate excited by a piezoelectric patch of variable rectangular geometry. The results demonstrate that modes can be selectively excited and that the geometry of the actuator shape markedly affects the distribution of the response among modes. It thus appears possible to tailor the shape of the actuator to either excite or suppress particular modes leading to improved control behavior.
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Paulsen, A., H. Dumlu, D. Piorunek, D. Langenkämper, J. Frenzel, and G. Eggeler. "Laboratory-Scale Processing and Performance Assessment of Ti–Ta High-Temperature Shape Memory Spring Actuators." Shape Memory and Superelasticity 7, no. 2 (June 2021): 222–34. http://dx.doi.org/10.1007/s40830-021-00334-1.
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AbstractTi75Ta25 high-temperature shape memory alloys exhibit a number of features which make it difficult to use them as spring actuators. These include the high melting point of Ta (close to 3000 °C), the affinity of Ti to oxygen which leads to the formation of brittle α-case layers and the tendency to precipitate the ω-phase, which suppresses the martensitic transformation. The present work represents a case study which shows how one can overcome these issues and manufacture high quality Ti75Ta25 tensile spring actuators. The work focusses on processing (arc melting, arc welding, wire drawing, surface treatments and actuator spring geometry setting) and on cyclic actuator testing. It is shown how one can minimize the detrimental effect of ω-phase formation and ensure stable high-temperature actuation by fast heating and cooling and by intermediate rejuvenation anneals. The results are discussed on the basis of fundamental Ti–Ta metallurgy and in the light of Ni–Ti spring actuator performance.
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Nhat, Nguyen Le Quang, and Nguyen Truong Thinh. "Development of the Bending Actuator with Nafion-Pt IPMC Tube." Advanced Materials Research 1119 (July 2015): 251–57. http://dx.doi.org/10.4028/www.scientific.net/amr.1119.251.
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IPMC (Ionic Polymer Metal Composite) is promising candidate actuator for bio-related applications mainly due to its biocompatibility, soft properties and operation in wet condition. In this paper, a new actuator will be presented. The tubular actuator, based on the concept of tip-displacement of IPMC actuator and capable of generating bending of tube with surface outside electrodes, was proposed and studied experimentally. The actuator is a Nafion tube consisting of an even number of Pt segments along the length, which are plated outside of tube surface, and the Pt segments act as electrodes to apply the driving voltage. The experimental data measured on prototype actuators prove the proposed concept of bending depend on the shape of Nafion. Show that the actuator functions well both displacement and force.
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Stetter, Ralf. "A Fuzzy Virtual Actuator for Automated Guided Vehicles." Sensors 20, no. 15 (July 26, 2020): 4154. http://dx.doi.org/10.3390/s20154154.
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In the last decades, virtual sensors have found increasing attention in the research community. Virtual sensors employ mathematical models and different sources of information such as actuator states or sensors, which are already existing in a system, in order to generate virtual measurements. Additionally, in recent years, the concept of virtual actuators has been proposed by leading researchers. Virtual actuators are parts of a fault-tolerant control strategy and aim to accommodate faults and to achieve a safe operation of a faulty plant. This paper describes a novel concept for a fuzzy virtual actuator applied to an automated guided vehicle (AGV). The application of fuzzy logic rules allows integrating expert knowledge or experimental data into the decision making of the virtual actuator. The AGV under consideration disposes of an innovative steering concept, which leads to considerable advantages in terms of maneuverability, but requires an elaborate control system. The application of the virtual actuator allows the accommodation of several possible faults, such as a slippery surface under one of the drive modules of the AGV.
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Khmelnitskiy, I. K., V. M. Aivazyan, N. I. Alekseyev, A. P. Broyko, V. V. Luchinin, and D. O. Testov. "Investigation of Ionic EAP Actuators with Metal and Polymer Electrodes in Aqueous Medium." Nano- i Mikrosistemnaya Tehnika 23, no. 1 (February 24, 2021): 32–43. http://dx.doi.org/10.17587/nmst.23.32-43.
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Electroactive polymers (EAP) are promising materials for creating electromechanical transducers. Among ionic EAP, ionic polymer-metal composites (IPMC), which are an ion-exchange membrane with metal electrodes on both sides, have been widely spread and well studied. The evolutionary development of IPMC results in ionic polymer-polymer composites (IP2C), in which polymer electrodes are used. To obtain IPMC actuators with platinum electrodes, the method of chemical reduction from the salt solution was chosen, and to obtain IP2C actuators with PEDOT electrodes, the method of in situ polymerization of the monomer on the membrane surface was chosen. Samples of 2x0.5 cm in size based on the MF-4SK membrane with a thickness of 290 μm were preliminarily kept in deionized water (H+ form) and in 0.1 M CuSO4 aqueous solution (Cu2+ form), after which their performance was studied in air, in deionized water, as well as in aqueous solutions of CuSO4 and NaCl. When applying a DC voltage and a sine wave AC voltage, a decrease in the maximum displacement and peak-to-peak displacement of the IPMC actuators and IP2C actuators with an increase in the ionic strength of the liquid was observed, except for the case of the IPMC actuator operation in CuSO4 aqueous solutions. In all considered media, the IPMC actuators and IP2C actuators in Cu2+ form displaced more strongly than the corresponding samples in H+ form, except for the IP2C actuators in deionized water. The largest peak-to-peak displacement was demonstrated by the IPMC actuators in Cu2+form when operating in air (5 mm) and the IP2С actuators in H+ form when operating in deionized water (8.4 mm).
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Li, Dawei, Guijuan Li, Lin Sun, and Yunfei Chen. "Numerical and experimental analysis of turbulent boundary layer control with piezo-ceramic actuator." International Journal of Applied Electromagnetics and Mechanics 64, no. 1-4 (December 10, 2020): 1217–26. http://dx.doi.org/10.3233/jae-209439.
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The effects of smart-material-based active surface perturbation (i.e. piezo-ceramic actuators) on wall shear stress and noise metric have been investigated by simulations and wind tunnel experiments. A periodic vibration through the application of piezo-ceramic actuators is imposed on the surface of a plate, and the vibration position is located on the upper part of the leading edge of the plate. Both the control results from simulations and experiments are close to each other, when the control parameters are the same. The simulations and wind tunnel experiments show that downstream skin-friction drag and noise metric can be reduced with the active control, and the reductions strongly depend on control parameters. Comparing with the near wall flow structures, the turbulent kinetic energy and characteristic turbulence length scale in the turbulent boundary layer can be controlled with the piezo-ceramic actuator.
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Karimi, Saber, Arash Zargar, Mahmoud Mani, and Arman Hemmati. "The Effect of Single Dielectric Barrier Discharge Actuators in Reducing Drag on an Ahmed Body." Fluids 5, no. 4 (December 15, 2020): 244. http://dx.doi.org/10.3390/fluids5040244.
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The feasibility of a single dielectric barrier discharge (SDBD) actuator in controlling flow over an Ahmed body, representing a simplified car model, has been numerically and experimentally investigated at Reynolds numbers of 7.68×105 and 2.25×105. The Ahmed body had slant angles of 25∘ and 35∘. The results showed that SDBD actuators could significantly enhance the aerodynamic performance of the Ahmed body. Several arrangements of the actuators on the slant surface and the rear face of the model were examined to identify the most effective arrangement for drag reduction. This arrangement resulted in an approximately 6.1% drag reduction. This improvement in aerodynamic performance is attributed to the alteration of three-dimensional wake structures due to the presence of SDBD, which coincides with surface pressure variations on the slant and rear faces of the Ahmed body.
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Zhang, Zhiyi, Yong Chen, Hongguang Li, and Hongxing Hua. "Simulation and Experimental Study on Vibration and Sound Radiation Control with Piezoelectric Actuators." Shock and Vibration 18, no. 1-2 (2011): 343–54. http://dx.doi.org/10.1155/2011/509675.
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FEM/BEM is adopted to model the interaction between the fluid and structures. In the modeling, modal truncation and inertial coupling are applied to sufficiently reduce the coupled model order. This approach is adopted for the purpose of constructing a modal model in the time domain. Active vibration control is realized with piezoelectric actuators and an adaptive method. In the control, the summation of vibration responses is used as the control error since the integral of acceleration on the plate surface is approximately proportional to the far field sound pressure. A rigidly baffled plate connected with a mass through one piezoelectric actuator is simulated at first. In the experiment, the plate is excited by a rotating eccentric mass and controlled with four piezoelectric actuators. The results have shown that active vibration control with the piezoelectric actuators can lead to a noticeable attenuation in sound pressure.
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Shang, J. S., and P. G. Huang. "Surface plasma actuators modeling for flow control." Progress in Aerospace Sciences 67 (May 2014): 29–50. http://dx.doi.org/10.1016/j.paerosci.2014.01.001.
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Qiu, Tian, Fabian Adams, Stefano Palagi, Kai Melde, Andrew Mark, Ulrich Wetterauer, Arkadiusz Miernik, and Peer Fischer. "Wireless Acoustic-Surface Actuators for Miniaturized Endoscopes." ACS Applied Materials & Interfaces 9, no. 49 (November 28, 2017): 42536–43. http://dx.doi.org/10.1021/acsami.7b12755.
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Makowski, Jan D., and Joseph J. Talghader. "Surface heterostructure nanomechanical actuators with atomic resolution." Applied Physics Letters 90, no. 18 (April 30, 2007): 183111. http://dx.doi.org/10.1063/1.2735675.
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Shrestha, Milan, Gih-Keong Lau, Anand Asundi, and Zhenbo Lu. "Multifunctional Smart Window Based on Dielectric Elastomer Actuator." Proceedings 64, no. 1 (November 21, 2020): 32. http://dx.doi.org/10.3390/iecat2020-08509.
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Soft actuators are compliant material-based devices capable of producing large deformations upon external stimuli. Dielectric elastomer actuators (DEAs) are a type of soft actuators that operate on voltage stimuli. Apart from soft robotics, these actuators can serve many novel applications, such as tunable optical gratings, lens, diffusers, smart windows and so on. This article presents our current work on tunable smart windows which can regulate light transmittance and sound absorption. This smart window can promote daylighting while maintaining privacy by electrically switching between being transparent and opaque. As a tunable optical surface scatters, it turns transparent with smooth surfaces like a flat glass; however, it turns opaque (translucent) with the micro-rough surface. The surface roughness is varied, employing surface microwrinkling or unfolding by using dielectric elastomer actuation. In addition, this smart window is equipped with another layer of transparent microperforated dielectric elastomer actuators (DEAs), which act like Helmholtz resonators, serving as a tunable and broader sound absorber. It can electrically tune its absorption spectrum to match the noise frequency for maximum acoustic absorption. The membrane tension and perforation size are tuned using DEA activation to tune its acoustic resonant frequency. Such a novel smart window can be made as cheap as glass due to its simple, all-solid-state construction. In the future, they might be used in smart green building and could potentially enhance urban livability.
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Song, Xiangshuai, Shujun Tan, Enmei Wang, Shunan Wu, and Zhigang Wu. "Active shape control of an antenna reflector using piezoelectric actuators." Journal of Intelligent Material Systems and Structures 30, no. 18-19 (August 30, 2019): 2733–47. http://dx.doi.org/10.1177/1045389x19873422.
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The surface precision of an antenna reflector can be improved using the actuation of piezoelectric materials to obtain a high-performance space antenna. In this study, the active shape control of a reflector with piezoceramic (lead zirconate titanate) actuators assembled on ribs is proposed by theoretical and experimental approaches. A finite element model of the integrated reflector–actuator system is established using piezoelectric constitutive equations and the virtual work’s principle. For a desired shape, a closed-loop iterative shape control method based on the influence coefficient matrix model is developed, which resolves the issue of high-precision shape control of the antenna reflector in the presence of model errors. The shape controller based on the proposed closed-loop shape control method is implemented on a planar hexagonal reflector with 30 lead zirconate titanate actuators. Experimental results demonstrate that the closed-loop control is an effective way to improve the surface precision of the reflector considering uncertainties.
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Botez, R. M., M. J. Tchatchueng Kammegne, and L. T. Grigorie. "Design, numerical simulation and experimental testing of a controlled electrical actuation system in a real aircraft morphing wing model." Aeronautical Journal 119, no. 1219 (September 2015): 1047–72. http://dx.doi.org/10.1017/s0001924000011131.
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AbstractThe paper focuses on the modelling, simulation and control of an electrical miniature actuator integrated in the actuation mechanism of a new morphing wing application. The morphed wing is a portion of an existing regional aircraft wing, its interior consisting of spars, stringers, and ribs, and having a structural rigidity similar to the rigidity of a real aircraft. The upper surface of the wing is a flexible skin, made of composite materials, and optimised in order to fulfill the morphing wing project requirements. In addition, a controllable rigid aileron is attached on the wing. The established architecture of the actuation mechanism uses four similar miniature actuators fixed inside the wing and actuating directly the flexible upper surface of the wing. The actuator was designed in-house, as there is no actuator on the market that could fit directly inside our morphing wing model. It consists of a brushless direct current (BLDC) motor with a gearbox and a screw for pushing and pulling the flexible upper surface of the wing. The electrical motor and the screw are coupled through a gearing system. Before proceeding with the modelling, the actuator is tested experimentally (stand alone configuration) to ensure that the entire range of the requirements (rated or nominal torque, nominal current, nominal speed, static force, size) would be fulfilled. In order to validate the theoretical, simulation and standalone configuration experimental studies, a bench testing and a wind-tunnel testing of four similar actuators integrated on the real morphing wing model are performed.
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Vrchota, Petr, Aleš Prachař, and Pavel Hospodář. "Verification of Boundary Conditions Applied to Active Flow Circulation Control." Aerospace 6, no. 3 (March 8, 2019): 34. http://dx.doi.org/10.3390/aerospace6030034.
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Inclusion of Active Flow Control (AFC) into Computational Fluid Dynamics (CFD) simulations is usually highly time-consuming and requires extensive computational resources and effort. In principle, the flow inside of the fluidic AFC actuators should be incorporated into the problem under consideration. However, for many applications, the internal actuator flow is not crucial, and only its effect on the outer flow needs to be resolved. In this study, the unsteady periodic flow inside the Suction and Oscillatory Blowing (SaOB) actuator is analyzed, using two CFD methods of ranging complexity (URANS and hybrid RANS-LES). The results are used for the definition and development of the simplified surface boundary condition for simulating the SaOB flow at the actuator’s exit. The developed boundary condition is verified and validated, in the case of a low-speed airfoil with suction applied on the upper (suction) side of the airfoil and oscillatory blowing applied on the lower (pressure) side, close to the trailing edge—a fluidic Gurney flap. Its effect on the circulation is analyzed and compared to the experimental data.
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Park, Sangwon, Wheejae Kim, Dongjoon Kim, and No-Cheol Park. "Shaping acoustic radiation induced by vibrotactile rendering on a touch surface." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, no. 2 (August 1, 2021): 4322–28. http://dx.doi.org/10.3397/in-2021-2661.
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Many electronic devices with touch-sensitive surfaces aim to provide vibrotactile feedback, along with visual or auditory feedback, to facilitate the interaction between the user and the interface. In parallel to these efforts, recent studies developed various vibration rendering techniques, enabling more complex vibration patterns to be generated on the touch surface. However, few have addressed sound radiation induced by vibrotactile rendering on a touch surface, which could significantly impact the haptic interaction's overall perception. This study presents a method to shape the acoustic radiation due to rendering high-fidelity vibrotactile feedback on a touch surface. The proposed method utilizes measured frequency response functions and a vibroacoustic representation of the touch surface to define the relationship between actuator driving signals, vibration responses on the touch surface, and radiated sound power. Proper actuator driving signals are derived from the optimization problem formulated using the relationship. The proposed method was demonstrated through vibration rendering experiments on a touch surface comprising an acrylic plate and voice coil actuators. The results showed that the proposed method could shape the acoustic radiation while rendering target vibration patterns at desired positions on the touch surface. This study's proposed method could allow haptic engineers to design vibrotactile feedback and sound radiation simultaneously for a more compelling haptic experience.
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Kaynak, Akif, Chun Hui Yang, and Abbas Kouzani. "Synthesis, Characterization and Analytical Modelling of Mechanical Behavior of a Conducting Polymer Actuator." Materials Science Forum 654-656 (June 2010): 2467–70. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.2467.
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Electrochemical synthesis of a tri-layer polypyrrole based actuator optimized for performance was reported. The 0.05 M pyrrole and 0.05 M tetrabutylammonium hexaflurophosphate in propylene carbonate (PC) yielded the optimum performance and stability. The force produced ranged from 0.2 to 0.4mN. Cyclic deflection tests on PC based actuators for 3 hours indicated that the displacement decreased by 60%. PC based actuator had a longer operating time, exceeding 3 hours, compared to acetonitrile based actuators. A triple-layer model of the polymer actuator was developed based on the classic bending beam theory by considering strain electrode material. A tri-layer actuator was fabricated [4, 6], by initially sputter coating a PVDF film with approximately 100nm of gold layer, resulting in a conductive film with a surface resistance of 8-10Ω. The PVDF film was about ~145µm thick had an approximate pore size of 45μm. A solution containing 0.05M distilled pyrrole monomer, 0.05M (TBAPF6) and 1% (w/w) distilled water in PC (propylene carbonate) solution was purged with nitrogen for 15 minutes. The continuity between PPy and PVDF. Results predicted by the model were in good agreement with the experimental data.
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Park, Minjeong, Sangwoo Kim, Keun Yong Sohn, Seonpil Kim, and Minhyon Jeon. "Poly(3,4-ethylene dioxythiophene):Poly(styrene sulfonate)-Functionalized Reduced Graphene Oxide Electrode for Ionic Electroactive Polymer Actuators." Science of Advanced Materials 12, no. 3 (March 1, 2020): 313–18. http://dx.doi.org/10.1166/sam.2020.3642.
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Ionic electroactive polymer (IEAP) actuators, which offer advantages such as reduced device weight, flexibility, and large deformation under low voltages (1–5 V), have found utility in applications such as biomimetic robots, actuators, and sensors. In this context, in this study, we fabricate poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate)-reduced graphene oxide (PEDOT:PSS-rGO) composite paper electrodes for actuator application. PEDOT:PSS-rGO paper electrodes are prepared by vacuum filtration of a PEDOT:PSS-rGO mixture that is subsequently subjected to heat treatment under an argon atmosphere via furnace annealing. We find that a 5:1 weight ratio of PEDOT:PSS-GO provides the lowest sheet resistance. We next fabricate a PEDOT:PSS-rGO actuator via filtration and the hot-pressing method with rGO paper electrodes, which have hydrophobic properties and low liquid permeability that effectively prevents water evaporation, and we examine its actuating performance. Our results indicate that after functionalization with PEDOT:PSS, the electrical properties and surface roughness of PEDOT:PSS-rGO composite paper electrode are improved. Further, the mechanical properties of the IEAP actuator based on the PEDOT:PSS-rGO paper electrodes exhibits enhanced performance by a factor of 4 relative to an actuator with conventional rGO electrodes.
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Ashley, Steven. "Magnetostrictive Actuators." Mechanical Engineering 120, no. 06 (June 1, 1998): 68–70. http://dx.doi.org/10.1115/1.1998-jun-3.
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This article demonstrates that materials that change their shapes when exposed to magnetic fields can now be used to drive high-reliability linear motors and actuators. The concept of magnetostriction effect has been the focus of efforts by engineers at ETREMA Products Inc. in Ames, Iowa, to device simple, high-reliability linear motors and actuators. The development of compact, low-voltage motors will offer advantages in applications in which high-force, extended-stroke, high-precision, and fail-safe-operating characteristics are required. ETREMA researchers are looking to improve Terfenol-D using material characterization methods, schemes to enhance the available strain, and better magnetomechanical design techniques. In the Terfenol-D-actuated device, an advanced-design wing flap incorporates multiple deployment segments that would smooth the airflow over the upper surface. During manufacture, Terfenol-D is melted, cast, and directionally solidified to provide the crystalline microstructure required to produce large strains. The strain and actuation force available from Terfenol-D are superior to those of other smart shape-change materials.
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Her, Shiuh-Chuan, and Han-Yung Chen. "Deformation of Composite Laminates Induced by Surface Bonded and Embedded Piezoelectric Actuators." Materials 13, no. 14 (July 17, 2020): 3201. http://dx.doi.org/10.3390/ma13143201.
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In this work, piezoelectric (PZT) actuators were surface bonded on or embedded in a composite laminate and subjected to an electric voltage across the thickness, resulting in a bending effect on the composite laminate. An analytical expression of the deflection of a simply supported cross-ply composite laminate induced by distributed piezoelectric actuators was derived on the basis of classical plate theory and composite mechanics. The theoretical solution can be used to predict the deformation of the composite laminate. Series of parametric studies were performed to investigate the effects of location, size, and embedded depth of PZT actuators on the composite laminate deformation. The analytical predictions were verified with finite element results. A close agreement was achieved. It demonstrated that the present approach provided a simple solution to predict and control the deformed shape of a composite laminate induced by distributed PZT actuators.
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Wang, Hongqiang, Peter York, Yufeng Chen, Sheila Russo, Tommaso Ranzani, Conor Walsh, and Robert J. Wood. "Biologically inspired electrostatic artificial muscles for insect-sized robots." International Journal of Robotics Research 40, no. 6-7 (March 31, 2021): 895–922. http://dx.doi.org/10.1177/02783649211002545.
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Millimeter-sized electrostatic film actuators, inspired by the efficient spatial arrangement of insect muscles, achieve a muscle-like power density (61 W kg−1) and enable robotic applications in which agility is needed in confined spaces. Like biological muscles, these actuators incorporate a hierarchical structure, in this case building from electrodes to arrays to laminates, and are composed primarily of flexible materials. So comprised, these actuators can be designed for a wide range of manipulation and locomotion tasks, similar to natural muscle, while being robust and compact. A typical actuator can achieve 85 mN of force with a 15 mm stroke, with a size of [Formula: see text] mm3 and mass of 92 mg. Two millimeter-sized robots, an ultra-thin earthworm-inspired robot and an intestinal-muscle-inspired endoscopic tool for tissue resection, demonstrate the utility of these actuators. The earthworm robot undertakes inspection tasks: the navigation of a 5 mm channel and a 19 mm square tube while carrying an on-board camera. The surgical tool, which conforms to the surface of the distal end of an endoscope, similar to the thin, smooth muscle that covers the intestine, completes tissue cutting and penetrating tasks. Beyond these devices, we anticipate widespread use of these actuators in soft robots, medical robots, wearable robots, and miniature autonomous systems.
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Yoon, Kwang Joon, J. D. Lee, K. B. Kim, Hoon Cheol Park, and Nam Seo Goo. "Design and Manufacturing of IDEAL with Stacked Ceramic Layers and Inter-Digitated Electrodes." Key Engineering Materials 306-308 (March 2006): 1175–80. http://dx.doi.org/10.4028/www.scientific.net/kem.306-308.1175.
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This paper is concerned with the development of stacked ceramic thin actuation layer IDEAL (Inter-Digitated Electrode Actuation Layer) using d33 actuation mechanism of piezoelectric ceramic. Most of the thin piezoelectric actuators are operated with d31 actuation mechanism. Many kinds of piezoelectric ceramic actuators are strived now to improve the actuation performance. One of efforts to improve performance of piezoceramic actuators is the research trying to develop an actuator using the piezoelectric coefficient d33. The piezoelectric coefficient d33 is almost twice larger than piezoelectric coefficient d31. Therefore, the induced strain of PZT thin layer with d33 actuation mechanism is bigger than that with d31 actuation mechanism. The AFC and LaRC-MFC used d33 actuation mechanism with surface interdigitated electrode to enhance its actuation performance. But their actuation mechanism is not perfect d33 actuation mechanism since the interdigitated electrodes are placed at the surface of the actuation layer. In this research, the stacked ceramic thin actuation layer with imbedded inter-digitated electrodes is designed and manufactured. The actuation strain of stacked ceramic thin actuation layer is measured and compared with the actuation strain of the LaRC-MFC. The comparison shows that the developed stacked ceramic thin actuation layer can produce 10% more actuation strain than LaRC-MFC at relatively high electric field.
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Watson, M., A. J. Jaworski, and N. J. Wood. "Application of synthetic jet actuators for the modification of the characteristics of separated shear layers on slender wings." Aeronautical Journal 111, no. 1122 (August 2007): 519–29. http://dx.doi.org/10.1017/s0001924000004760.
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Abstract This paper presents an experimental investigation related to controlling the unsteady characteristics of the separated shear layers occurring over highly swept wings, and in particular focuses on application of synthetic jet actuators for modification of unsteady dynamic loading on the wing surface due to the phenomenon referred to as vortex breakdown (vortex burst). In the post burst flow region the surface pressure measurements reveal the presence of certain characteristic spectral peaks that are thought to represent the presence of a spiralling filament of vorticity inside the expanded vortex that is known to be present in the burst flow over swept wings. This paper details an investigation into how the use of an array of 18 discrete synthetic jet actuators, distributed along the leading edge of a delta wing with a 60° sweep angle, can be used to alter the spectral content of this unsteadiness and reduce the level of unsteady pressure found in the post-burst region toward the wing trailing edge by up to 40%. Measurements of the surface pressure spectral distributions over the wing are presented together with PIV measurements of the vortex cross-section, conducted in the successive planes parallel to the wing trailing edge. Additional surface flow visualisation indicates that the effect of the actuators on the leading edge boundary layer is to induce local separation delays close to each actuator orifice, which introduce ‘ripples’ into the shear layer as it separates. The results obtained are used to formulate an interpretative hypothesis attempting to explain the mechanisms responsible for modification of the spectral content and the level of excitation measured on the wing surface.
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Konieczny, Jarosław, Marek Sibielak, and Waldemar Rączka. "Active Vehicle Suspension with Anti-Roll System Based on Advanced Sliding Mode Controller." Energies 13, no. 21 (October 23, 2020): 5560. http://dx.doi.org/10.3390/en13215560.
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In the paper authors consider the active suspension of the wheeled vehicle. The proposed controller consists of a sliding mode controller used to roll reduction and linear regulators with quadratic performance index (LQRs) for struts control was shown. The energy consumption optimization was taken into account at the stage of strut controllers synthesis. The studied system is half of the active vehicle suspension using hydraulic actuators to increase the ride comfort and keeping safety. Instead of installing additional actuators in the form of active anti-roll bars, it has been decided to expand the active suspension control algorithm by adding extra functionality that accounts for the roll. The suggested algorithm synthesis method is based on the object decomposition into two subsystems whose controllers can be synthesized separately. Individual suspension struts are controlled by actuators that use the controllers whose parameters have been calculated with the LQR method. The mathematical model of the actuator applied in the work takes into account its nonlinear nature and the dynamics of the servovalve. The simulation tests of the built active suspension control system have been performed. In the proposed solution, the vertical displacements caused by uneven road surface are reduced by controllers related directly to suspension strut actuators.