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In this work, the fabrication of Rochelle salt based piezoelectric structures is illustrated. Structures composed of paper and Rochelle salt are easily manufactured using simple processes. Both manufacturing and the material itself are environmental friendly. Additionally Rochelle salt is biocompatible. In the paradigm of a cleaner piezoelectric technology, the fabrication of active sensing or actuating devices is developed. Thus processing method, material and piezoelectric properties have been studied: (1) pure crystals are used as acoustic actuator, (2) properties of paper impregnated with Rochelle salt are detailed, (3) charge generation is demonstrated on the impregnated material. Actuating and sensing devices are reported in order to highlight the potential of this green piezoelectric material. [ABSTRACT FROM AUTHOR]

Liquid-phase exfoliation of few-layer graphene in Coca-Cola ® was performed by a kitchen blender for rapid preparation of strain/light/humidity sensitive ink. The advantages of Coca-Cola as an exfoliating medium have been identified from the low structural defect (I D /I G = 0.39) and, moderate carbon to oxygen ratio (C/O = 2.6) obtained by the resulting graphene. It is discovered that a deposition of graphene on photo paper allowed a facile fabrication of smart paper that is able to detect minor strain (0 – 2.0%) with GF of 18.7. Meanwhile, the multi-responsiveness of ink towards light/humidity had been validated from the 10 s response time after the exposure to stimulants with the maximum resulting curvature degree of 16° and 14° under light and humidity changes, respectively. Finally, it is shown that our actuator is able to vertically lift a load (545 mg) from its initial flat position upon irradiation of light (200 mW/cm2). [Display omitted] [ABSTRACT FROM AUTHOR]

In machine hammer peening, an actuator system moves a ram in oscillating motion, which is oriented in angular position, preferably perpendicular, to a workpiece surface. On the tip of the ram, a hammer head with application specific shapes can be mounted. The hammer head is moved across the targeted workpiece surface area by means of a machine tool or an industrial robot. The impacts in defined patterns enable modifications of the surface integrity like smoothing the surface roughness or increasing fatigue strength by induced compressive residual stresses. This paper presents a novel DC-driven actuator system using a highly dynamic short-stroke linear reluctance motor to provide a time or trigger controlled hammer head movement including a system for process monitoring. In contrast to conventional systems, Deterministic Impact Peening (DIP) can be realized by position or speed related triggering of the impacts. The reluctance-based actuator with its geometrically optimized mechatronic system design provides performance characteristics favorable to known machine hammer peening systems. The position-controlled triggering of the hammer head is able to achieve uniform or defined local elastoplastic deformations on the workpiece surface, thus resulting in deterministic residual stress distributions. [ABSTRACT FROM AUTHOR]

The use of lightweight materials such as carbon fibre reinforced plastics (CFRP) is increasing due to the demand for rising resource and energy efficiency, especially in the aerospace and automotive industries. Because of the high delamination tendency of these materials and their abrasive impact on the tool, the challenges in machining CFRP lie primarily in the drilling process and thus in the design of the drilling tool. In this paper, an innovative design of a drilling tool for machining CFRP with force-controlled radial feed movement of the cutting edges is presented. The aim of this tool is to create a tool axial force free process that uses a force-controlled radial feed motion, which matches the chip cross-section to the wear condition of the cutting edge. The tool concept is explained based on the functionality of the actuating process. Tests were evaluated with regard to process forces and drilling quality to show that the tool is capable of producing delamination-free bores in a tool axial force free process. [ABSTRACT FROM AUTHOR]

In the process industry, the actuator has complex operating processes. Its steady working conditions are easy to change. Moreover, it is in a dynamic process for long periods of time. These phenomena reduce the accuracy and timeliness of many condition monitoring (CM) methods. In this paper, a fault detection mechanism considering the complex operating processes of the actuator is proposed. One of its main feature is that it can detect faults under steady state regardless of variable load changes. The other is that it has ability to detect faults during dynamic processes refusing the interference of nonlinearity and dynamic characteristics. Firstly, an actuator data model library based on historical data is established offline. Secondly, in the online situation, after the R indicator divides the testing data into steady state or dynamic, it is input into the model library to obtain a standard training set. Finally, the steady-state/dynamic fault detection module will determine whether a fault has occurred based on the testing data and the training set. Moreover, open-loop experiments based on the DAMADICS (Development and Application of Methods for Actuator Diagnosis in Industrial Control Systems) platform and closed-loop experiments based on the water tank system are designed. These experiments show that, compared with other methods, the proposed fault detection framework has better monitoring performance during complex operating processes of actuators. • A novel actuator fault detection method is proposed. • It can deal with various complex operating processes containing steady and dynamic state. • It contains two novel extended non-negative matrix factorization algorithms. • The presented mechanism is verified by simulations and experiments. [ABSTRACT FROM AUTHOR]

[Display omitted] • A 3D numerical study was conducted on a micromixer with an oscillating microbeam. • Effects of oscillation frequency and Reynolds number on mixing were investigated. • The optimum operating condition was found for this micromixer. • Four novel designs were proposed by adding passive techniques to this micromixer. • The maximum mixing index was 88% in 0.4 s. In this research, we numerically studied a three-dimensional (3-D) T-shaped active micromixer which works based on the oscillations of a cantilever microbeam. We explored the influence of microbeam's oscillation frequency (10–40 Hz) and flow Reynolds number (2.5–30) on mixing performance, revealing optimal operating conditions. Under optimal operating conditions, using a simple microbeam in a short straight microchannel, the micromixer achieved a 76.7 % mixing index within just 0.4 s. In the next part of this paper, we introduced modifications to the microbeam and microchannel geometries to enhance mixing performance further. Adding a circular part to the channel improved the mixing index to 85.7 %. In a more complex configuration, characterized by a perforated microbeam and a circular microchannel, the micromixer achieved its highest efficiency of 88 %. Additionally, a novel configuration employing two microbeams within a straight channel achieved a mixing efficiency of 82.2 %. [ABSTRACT FROM AUTHOR]

Nowadays, design, development, and motion planning of a mobile robot explore research areas in the field of robotics. Mobile robots have an extensive area of applications in various fields like space exploration, military application, industrial use, and many more. Hence, the design and development of a mobile robot is a crucial part of the above application. Among all the mobile robot, the quadrupedal robot is a legged robot, which is superior to wheeled and tracked robot due to its potential to explore in all the terrain like the human and animal. In this paper, the survey concentrates on various design and development approaches for the quadrupedal robot, and environment perception techniques are discussed. Besides, Spot is one of the most advanced and intelligent quadrupedal robots. The performance of each quadruped robot and the future outline are provided in details. [ABSTRACT FROM AUTHOR]

This paper deals with analysis of main functional diagrams of step PID controllers for electric motor-driven actuators. The main formulae to calculate the parameters of the diagrams of step PID controllers are presented in the paper. The influence of these parameters on the transient processes in step controllers and on the output position of the actuator is analyzed. Transient processes in step controllers with motor-driven actuators are simulated in PI and PID control mode. These transient processes are compared to the transient processes in continuous controllers. The accuracy of step PID controllers is analyzed, and restrictions on the parameters of step PID controllers are presented. The diagrams of step PID controllers considered in this paper can be implemented in the up-to-date PLCs software for automatic control using the electric motor-driven actuators in the control loops. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports on the optimization of electrodes design for sol-gel Pb(Zr0.52, Ti0.48)O3 (PZT) thin-film actuated-membranes. PZT can be used in many actuator applications such as micro mirror, RF MEMS, inkjet or loudspeaker due to its strong piezoelectric properties. We aim to design membrane-based actuators with the optimum electrode dimensions allowing the largest membrane displacement under a given actuation voltage. We present in this paper measurement results, in good agreement with the finite element modeling, proving that an actuator area between 50 and 60% of the membrane area exhibits the highest deflection. [Copyright &y& Elsevier]

Abstract: The paper presents component concepts developed for the ITER core charge exchange recombination spectroscopy (cCXRS). They are based on the cCXRS layout of 2009, named as reference design option. It includes an outer shell, carrying a blanket shield module and a shielding cassette. The cassette, attached to the outer shell, carries secondary mirrors and a retractable tube. The tube holds a first mirror (M1) and a shutter. Development priority is given to the M1, M1 holder, shutter, calibration system and retractable tube. These units are the most critical from reliability point of view. The developed design approaches could be likely used as generic or prototype solutions for a cCXRS diagnostic port plug in future. Before prototyping critical components as the M1 holder and shutter, the final cCXRS conceptual design has to meet forthcoming changes in the ITER diagnostic upper port plug (UPP) and blanket system. The integrated first wall—diagnostic shield modules, first wall recession, blanket shaping and generic UPP layout have considerable impact on the layout of the cCXRS and its components. The paper presents a preliminary solution for integration of the customized reference cCXRS into expected ITER blanket and UPP layouts. [Copyright &y& Elsevier]

Highlights • An active heat sink with agitators, synthetic jets, and micro pin fins is introduced. • The active heat sink is a more efficient method than traditional fan-assisted systems. • The active heat sink reduced a thermal resistance by 48% from the baseline condition. • The micro pin fins are most efficient in reducing the system thermal resistance. Abstract Air-cooled heat sinks are widely used for electronics cooling. Active and passive cooling components can be added to enhance the performance of the air-cooled heat sinks. In this paper, piezoelectric translational agitators and synthetic jets are integrated as active cooling components while micro pin fins are adopted as a passive cooling scheme. The heat transfer performance of the active heat sink system that combines these active and passive cooling components along with a suction fan is experimentally investigated. The piezoelectric translational agitators installed within cooling channels are operating at 222 Hz ∼ 820 Hz with a peak-to-peak displacement of 1.0 mm ∼ 1.4 mm, depending on the attached carbon fiber blade type. The piezoelectric synthetic jet array provides impingement flow into the cooling channels with an inclined configuration, that has been successfully integrated into the system without interference with other components by using a wedge platform. The jet operates at 720 Hz with the jet velocity of up to 39 m/s. Micro pin fins are fabricated onto both surfaces of each heat sink channel walls by a double-sided microfabrication technique. They have diameter, height, and spacing of 500 μm, 250 μm, and 1500 μm, respectively. The experimental results indicate that the micro pin fins are most efficient among the employed active and passive cooling components, reducing thermal resistance up to 38%, compared to plain heat sink performance. The piezoelectric translational agitator reduces system thermal resistance by 22%, compared to the non-agitated condition, at the same through-flow rate. The synthetic jet shows weaker cooling capability in the setting tested, compared to enhancement by the agitator plates or pin fins. The active heat sink with the micro pin fins, agitators, and jets provides a thermal resistance of 0.064 °C/W at 70 CFM (33 L/sec) through-flow of air, about a 48% reduction from that of the non-agitated, plain heat sink under the same operating conditions. The results demonstrate how more effective the active heat sink system is compared to traditional air-cooled heat sinks. [ABSTRACT FROM AUTHOR]

In this paper, we propose a method for taking into account uncertainties of a micro-pump system using Shape Memory Alloy (SMA), based on the perturbation method. The proposed method is used to determine the thermo-mechanical response of a system. Comparisons with the mean value reference solution, illustrate the efficiency of the proposed method. The results are discussed in order to investigate the influence of the most influential parameters of the thermomechanical SMA model. The simulation results are obtained by the proposed method for static analysis with uncertainties.The perturbation method results are compared with the mean value reference solution. The results are discussed in order to investigate the influence of the Young's modulus E, the two transformations strain magnitude ɛ t r a c T and ɛ t r a c T F A , the martensite start M s and austenite finish A f temperatures and the stress reorientation F ε on the static response of a micro-pump system. [ABSTRACT FROM AUTHOR]

Abstract: This paper investigates the electro-mechanical behaviour of a thick, laminated actuator with piezoelectric and isotropic lamina under externally applied electric loading using a new two-dimensional computational model. The elastic core is relatively thick and thus it is modelled by Timoshenko thick-beam theory. Although the piezoelectric lamina is a beam-like layer, it is formulated via a two-dimensional model because of not only the strong electro-mechanical coupling, but also of the presence of a two-dimensional electric field. It is shown in this paper that a one-dimensional model for the piezoelectric beam-like layer is inadequate. The piezoelectric model is constructed within the scope of linear piezoelectricity. The actuation response is induced through the application of external electric voltage. Under the strong coupling of elasticity and electricity, the strain energy and work of electric potential are presented. The electro-mechanical response of the laminated Timoshenko beam is formulated and determined via a variational energy principle. Numerical examples presented illustrate convincing comparison with finite element solutions and existing published data. New numerical solutions are also presented to investigate the geometric effect on the electro-mechanical bending behaviour. [Copyright &y& Elsevier]

• A real-time hybrid testing based on shaking table and actuator is proposed for cable tray system. • The proposed method is validated by numerical simulations. • The proposed method is experimentally validated by one cable tray system. For precisely disclosing the seismic performance of cable tray systems, one novel Real-Time Hybrid Testing based on Shaking Table and Actuator (RTHT-STA) is proposed in this paper. In the proposed method, one shaking table is used to simulate the ground motion, and one servo-hydraulic actuator controlled with displacement mode is set up on the shaking table for truly simulating the transverse shear boundary conditions between the numerical substructure and the experimental substructure of cable tray systems. The advantage of the proposed method is accurately realizing the loading requirements of high-precision large deformation on cable tray systems. The effectiveness and accuracy of the proposed method are validated by numerical simulations and experimental tests. The experimental results show that the real-time hybrid testing system is stable and reliable. The correlation coefficients between the results of the proposed method and those of the traditional shaking table tests are higher up to 91.78%. The results indicate the effectiveness and the high accuracy of the proposed RTHT-STA for cable tray systems. The RTHT-STA provides an economical and precise investigation strategy for disclosing the seismic performance of cable tray systems and may have broad application prospects in the field of communication engineering and civil engineering. [ABSTRACT FROM AUTHOR]

In this paper, a novel actuator in the form of a Kagome truss composed of shape memory alloy (SMA) wires and common metallic wires is described. In the actuator, the SMA wires play dual roles as load supporters and actuating elements. The intersections between the SMA wires and between the SMA wires and the common metallic wires were joined by using shrinkable tubes, which induced the kinematically compatible buckling of the columns of SMA wires under compression, consequently enabling the large actuation displacement of up to 30% of the height with some sacrifice of the load capacity. An analytic solution was derived using the elementary mechanics of buckling and geometric relation of curved column, which gave fairly good estimation of the behavior of the Kagome actuator for the deformation and actuation stages, based on the behavior of a single SMA wire. The lightness and large actuation range of this actuator appear to be useful for practical applications. [ABSTRACT FROM AUTHOR]

The paper considesr non-global structural analogues actuators for shut-off and control ball valves with double-gate, providing exceptional technical characteristics (bandwidth and control range) in comparison with the analogues. Equipping such ball valve with an intelligent actuator featuring a special Geneva mechanism allows using only one actuator to provide the shut-off function, control, and deduction of a required working position with no energy required. This provides significant additional economic benefits compared to the known imported functional equivalents. The analytical review of existing constructive actuators solutions is conducted and the issued related to the calculation of their main characteristics are reviewed. [ABSTRACT FROM AUTHOR]

A diffusion behavior of hydrogen in a hydrogen storage alloy is affected by not only hydrogen concentration but also the stress induced by hydrogen atom expanding the lattice of the alloy. The uphill diffusion in which hydrogen diffused against the concentration gradient due to the stress has been observed. Moreover, the fugacity of hydrogen in the alloy deviates from unity significantly even at low hydrogen concentration, which decreases the flux. In this paper, the effect of the stress and the diffusion coefficient variation with the concentration on hydrogen diffusion at low concentration was investigated using the finite element analysis. As a result, the variable diffusion coefficient model combined with the stress effect showed better agreement with the experimental result than Fick's diffusion models and the constant coefficient SID model. It was concluded that the effect should be considered even if the concentration is low. [ABSTRACT FROM AUTHOR]

A Digital Loudspeaker Array (DLA) is an electro-mechanical transductor which receives a numerical signal as input data and allows the analogical conversion directly in the air. We designed PZT actuated membranes in order to obtain the highest acoustic pressure as possible. We built 256-MEMS-membranes DLAs using a generic PZT technology and digital acoustic reconstructions of the sound have been already demonstrated using our MEMS-DLA. In this paper, using FEM simulations, we evidence that residual stresses are responsible of the high distortion level measured on our demonstrators. A stress compensated technology was established using FEM approach. Acoustic characterization of stress compensated demonstrators proves distortion decreased and validates our hypothesis. [ABSTRACT FROM AUTHOR]

This paper considers a thermal phase change actuator filled with a solid–liquid phase change material (PCM), in which its ceiling wall can be thermally activated to move as a result of the volumetric changes associated with thermally induced melting and freezing processes of the PCM contained. Specifically, the present study aims to explore experimentally the dynamic response characteristics of the actuator’s movable wall during the melting process of a paraffin (n-Octadecane) as the PCM filled in a rectangular container. Melting experiments for the phase change actuator heated laterally at various isothermal wall temperatures with the solid PCM filled at different initial subcooling temperatures below its melting point have been undertaken to examine the melting heat transfer characteristics as well as the displacement behavior of its movable wall. The experimental results obtained reveal clearly that the melting progress of the PCM within the actuator has a dominant bearing on the induced moving speed and thus the total displacement of its movable wall. Moreover, the subcooling condition for the solid PCM filled in the actuator during the melting process may give rise to significant time lag for its thermally driven response, hence increasing the total time required for the solid PCM to be fully melted. [ABSTRACT FROM AUTHOR]

This paper presents a novel thimble-shape haptic display for multi-mode tactile feedback at fingertips. The device has two special characteristics. Multi-mode feedback, i.e., static pressure, high-frequency vibration, and impact force, can be generated via a single actuator mechanism of a pneumatic chamber controlled by high-speed valves. Additionally, the actuator's softness makes this device a "feel-through" tactile display where the user simultaneously feels responses from a real object and synthetic feedback. This makes the device a fit for haptic augmented reality-based display where real and virtual touch feedback is merged into single feedback that haptically "augments" the real world. A layered combination of flexible and non-flexible silicone membrane surrounds the air- cavity for desired efficiency, and systematic valve control algorithms are developed for rich haptic effects. The experiments confirmed that the system generated a static force up to 7 N, acceleration magnitude up to 1.4 G, and frequency up to 250 Hz. The device exhibits two realistic tactile signals, i.e., virtual textures and button clicks, based on real signals and a physical surface that are augmented with two haptic signals.The user studies revealed that the participants found the virtually overlaid textures and buttons to be perceptually similar to their real counterparts. [ABSTRACT FROM AUTHOR]

This paper reports on the development of a unique Digital Loudspeaker Array solution, based on Pb(Zr 0.52 ,Ti 0.48 )O 3 (PZT) thin-film actuated membranes, arranged in a matrix and which operate in a binary manner by emitting short pulses of sound pressure. Using the principle of additivity of pressures in the air, it is possible to reconstruct audible sounds. For the first time, electromechanical and acoustic characterizations were reported on 256 MEMS membranes DLA. Sounds audible as far as several meters from the loudspeaker have been generated using low-voltage. [ABSTRACT FROM AUTHOR]

In this paper ohmic switches allowing sequential switching of multiple contacts to improve the device reliability are proposed. The switches are based on a novel design concept featuring bidirectional operation using both piezoelectric and electrostatic actuation. To enhance the hot switching capabilities two sequentially operating contact groups are introduced, enabling the protection of the low resistive contact by a more reliable contact. Measurement results of fabricated MEMS switches have proven that reliable sequential switching is achieved independently from the contact gap and actuation mode. Furthermore, the switches feature very low contact resistances of less than 0.3 Ω and are able to overcome contact sticking under hot switching by applying bidirectional actuation. [ABSTRACT FROM AUTHOR]

Moving beyond the traditional scope of cyberphysical systems this work presents μAutonomy, a novel proposal in the field of connected intelligent actuating objects. In this paper, we identify and study the implications of controlling moveable objects in a cyberphysical environment. This kind of environment is rapidly gaining attention in applications that include control of unmanned aerial vehicles, high altitude orbit control of robotic exploration probes, or robotic tele-diagnostics. Our work introduces a mechanism that greatly improves the operation of actuating objects over wireless links of varying quality. The proposed approach successfully compensates for communications impairments by tracking the system state and deciding course of action based on probabilistic principles. We tested our proposal using an experimental testbed consisting of an unmanned small-scale vehicle and present experimental results obtained through an extensive human subject based study. Our results show how the proposed mechanism significantly compensates for channel impairments aiding in the completion of a variety of basic tasks. [ABSTRACT FROM AUTHOR]

At first a detailed fast shutter design was finalized for the ITER core charge exchange recombination spectroscopy (CXRS) diagnostic. The shutter has approximately 70 kg of mass and a length of 2.1 m. It operates in fractions of a second (0.7 s) protecting critical optical components against degradation and providing means of calibration for the optical system. The shutter structure is driven by a bidirectional frictionless helium actuator, with forces and axial strokes of 3.4 kN and 2 mm respectively. The shutter structure consists of: (a) two blades made of CuCrZr and stainless steel, calibration surfaces (currently Al 2 O 3 ) on the top and on the bottom a protective TZM (Mo–0.5Ti–0.08Zr) screens, (b) two arms interconnected that form one cooling circuit including the blades, (c) a bumper system to limit the arms movement, and (d) a support. A description of these components and their functions are given in this paper, followed by some issues, and their corresponding solutions or ongoing investigations, encountered during the design work. Detailed manufacturing drawings have been developed as the deliverable final product of this design stage, and are used in the prototyping phase which includes testing, numerical benchmarking, and validation of the shutter concept. [ABSTRACT FROM AUTHOR]

Soft actuators with large deformation and high stability in response to multi-stimuli are highly demanded in biomimetic applications. However, most of the present actuators driven by a single stimulus often exhibit low performance and high energy consumption. In this work, a sandwich structural soft actuator (MPDMS/MXene/PTFE) which possesses electrothermal/magnetic coupling actuation is fabricated by combining magnetic NdFeB/Polydimethylsiloxane (MPDMS) composite layer, MXene film, and PTFE tape together. Due to the large difference of thermal expansion coefficient between MPDMS film and PTFE tape, the soft actuator shows a wonderful electrothermal actuation and the bending deformation can reach to as high as 353° under a 3 V power supply. The excellent electrical conductivity of MXene component endows the sandwich film with good thermal management performance, thus the soft MPDMS/MXene/PTFE sandwich films can be applied in the thermal treatment of body and thermal imaging. Most importantly, the soft actuator also exhibits a typical magnetic biomimetic actuation and the programmable actuation performance of the dragonfly actuator can be demonstrated by both experiments and finite element simulations. Eventually, the electrothermal/magnetic coupling actuation is successfully applied in an intelligent crawling robot to overcome the traditional inchworm movement simulation. A dual-mode biomimetic soft actuator based on MPDMS/MXene/PTFE with excellent electrothermal and magnetic drive performance is developed. The soft actuator enables to prepare grippers for transferring objects and assemble the wings of a biomimetic dragonfly in a magnetic field. Finally, a crawling robot is developed to demonstrate the electrothermal/magnetic coupling actuation. [Display omitted] • The highlight of this work is: • The MPDMS/MXene/PTFE soft actuator presents both electrothermal and magneto-actuated deformation behaviors. • The soft actuator shows a wonderful electrothermal actuation and the bending deformation can reach to as high as 353° under a 3 V power supply. • The finite element analysis model can provide design guidance for the deformation process of bionic actuator with complex structure. • The soft actuator strategy presented in this paper is expected to be useful for the development of bionic intelligent actuators with multi-stimulus response. [ABSTRACT FROM AUTHOR]

The paper presents active vibration isolation systems based on “smart” materials. Very promising “smart” materials are MR elastomers. Devices based on them have the ability to work in all vibration isolation modes (passive, semi-active and active mode). In this work we consider a construction of a damper based on the MR elastomer and the experimental research results of the damper in semi-active vibration isolation mode. [ABSTRACT FROM AUTHOR]

In this paper novel design concepts for ohmic RF-MEMS switches based on piezoelectric and electrostatic actuation are presented. In contrast to traditional cantilever designs the proposed concepts are based on circular and ring shaped piezo actuators offering significant advantages especially in providing high contact forces. As a result of a parametric study optimized designs have been developed which can deliver more than 2 mN force at small device sizes of less than 0.08 mm 2 . First actuator prototypes featuring 1 μm sputtered PZT films are currently being fabricated by means of MEMS technology. [ABSTRACT FROM AUTHOR]

Hardware-in-the-loop simulation (HILS) and dynamically substructured system (DSS) techniques are generally classified as hybrid methods for performance evaluation of engineering systems, combining both numerical simulation and hardware experiment parts. Principally, HILS techniques are widely applied to testing of power electronics and vehicle systems, while DSS methods emphasise on civil and structural engineering application. Although the two strategies are present in different fields, the similarity and difference between them are briefly discussed in this paper, in order to facilitate cross-literature communication about testing methodologies. [ABSTRACT FROM AUTHOR]

Abstract: For the ITER core charge exchange recombination spectroscopy (CXRS) upper port plug #3 (UPP) diagnostics, a fast shutter is necessary for the first optical mirrors. The shutter concept for the reference CXRS layout has been well developed and studied focusing on the structure dynamic behavior. This paper presents two shutter concepts for the new baseline layout. Concept-1 is similar to the reference concept, including the helium actuator attached to the diagnostic shielding module (DSM) in the primary vacuum. Concept-2 considers the actuator outside the primary vacuum. It is attached to the back side of the UPP and connected to the shutting mechanism with a push–pull rod. Assembly and disassembly, actuator location, and actuation type are key issues for concept assessment. For a feasibility study, two different leak cases for the shutter concepts have also been analyzed. Concept-1 requires a specialized actuator design compatible with the in-vessel conditions. The actuator size is limited by the lack of available space in the DSM. This option needs complex procedures to access the actuator for maintenance. Concept-2 allows the use of standard pneumatic/hydraulic actuators and other industrial components. Space allocation is needed inside the UPP to accommodate the push–pull rod system. Concept-2 allows independent maintenance procedures for the actuator(s) and the shutting mechanism. It was generally concluded that both options are suitable for the new baseline layout, and are to be studied in detail. [Copyright &y& Elsevier]

Abstract: This paper presents a flexible artificial muscle actuator using coiled shape memory alloy (SMA) wires. The actuator mainly consisted of flexible materials and SMA wires and the fabrication was based on molding of silicon rubber. The actuator was also characterized by the motion with the body in flexion. We measured several characteristics to investigate a relationship between the bending angle of its body and the actuation. As the results, we confirmed that it was possible to actuate with the body in flexion. [Copyright &y& Elsevier]

This paper presents a new fabrication technology for conducting AFM cantilevers with integrated AlN-based piezoelectric actuators. A major effort has been done for the process integration of a high quality AlN layer onto the Si cantilever together with a high wear resistance, PtSi-based conducting tip. Functional AFM devices have been successfully tested in tapping mode imaging experiments. Such type of cantilevers are of great interest for dynamic AFM applications especially for tapping or dithering mode AFMs as well as for using the piezoelectric structures as an integrated position sensor. [ABSTRACT FROM AUTHOR]

Abstract: Piezoelectric (PZT) actuator is a device based on counter piezoelectric effect, applying a voltage to it creates a displacement, and vibrating it generates a voltage. PZT actuator is a controllable and perfect micro-displacement actuator that is driven by electric field. PZT actuator has a very high-speed response, a small volume, a little quantity of heat and a relatively light mass. The excellent performance of PZT actuator makes it have considerable potential in the area of active control. This paper describes the application in active engine mount mainly. The simulation result show that the active PZT engine mount has a very good isolation performance, and can reduce around 80% vibration, and act very well at both lower and higher frequency. [Copyright &y& Elsevier]

Abstract: The behaviour of a piezoelectric actuator is strongly affected by the bonding condition along the interface between the actuator and the host structure. The current paper represents an analytical study of the static effect of the mechanical and geometrical properties of the adhesive layer on the coupled electromechanical behaviour of a thin piezoceramic actuator bonded to an elastic medium. An actuator model with an imperfect adhesive bonding layer, which undergoes a shear deformation, is proposed to simulate the two dimensional electromechanical behaviour of the integrated system. Analytical solution of the problem is provided by solving the resulting integral equations in terms of the interfacial stress. Numerical simulation is conducted to study the effect of the bonding layer upon the actuation process. The effect of interfacial debonding on the response of the layered structure and on the interlaminar strain and stress transfer mechanisms is discussed. [Copyright &y& Elsevier]

Abstract: A protocol for characterizing a novel light-weight actuator with high actuating capability is proposed and analyzed in this paper. The actuator is a sandwich structure composed of truss cores and smart face-sheets in which overall bending may occur when actuated. The deformation of this beam actuator is generated by varying the voltage applied at the face-sheets made up of smart material. The basic mechanical properties, such as the effective moduli of the structure, are discussed, and then optimization is designed to obtain the minimum weight or maximum achievable displacement subjected to two types of constraints. Analysis indicates that the composite trusses have higher stiffness and strength than the metal-trusses structure with the same density. The relationship between the actuating capability and geometric parameters is also investigated by numerical simulations. Compared with two corrugated-core actuators, the truss-core actuator has better actuating capability within a specific weight range. [Copyright &y& Elsevier]

Abstract: In this paper, the carbon nano-fibers (CNFs) were used to improve the performance of sulfonated poly(styrene-b-[ethylene/butylene]-b-styrene) (SSEBS) composite actuator. The SSEBS actuator, which was developed in our previous study, does not have good electromechanical performance because the SSEBS ionic polymer is too flexible and soft. CNFs as a reinforcement for the polymer membranes greatly increased the bending performance of the SSEBS actuators. The surface and cross-sectional morphologies of the CNF-SSEBS actuators were investigated by SEM observation. The results show that carbon nano-fibers were homogeneously dispersed in the SSEBS polymer matrix without local agglomeration. The bending responses of the CNF-SSEBS composite actuators under step inputs and sinusoidal excitations were compared with those of the pure SSEBS actuator. The tip displacement of the CNF-SSEBS actuator was much faster and larger than that of the pure SSEBS actuator. [Copyright &y& Elsevier]

Abstract: In this paper we report a highly sensitive capacitive pressure sensor and transducer, with ultra high capacitance values, based on branched carbon nanotubes on ultra thin silicon membranes. The presence of tree-like CNTs is believed to be responsible for high overlap between fingers which results in a significant capacitance change of the fabricated pressure sensor by applying pressure. Also, by applying an external voltage between fingers at one side of the ultra thin membrane an observable actuation was obtained. This actuation is sensed by a capacitive interdigital sensor at the other side of the same membrane. [Copyright &y& Elsevier]

Abstract: In this paper equations governing the linear response of piezothermoelastic plate are outlined based on the Hamilton’s principle and finite element methods. Linear shape functions are used and the first-order shear deformation theory of laminated plates is considered. The governing equations are solved using the Newmark time marching method. The numerical results are presented for cases of a prescribed thermal loading and the conventional piezo-control of the forced vibrations in a thermoelastic composite plate caused by sudden mechanical loading. Vibration amplitudes are suppressed through application of electric potential differences across the piezoelectric layers attached to the surfaces of the composite plate. Controlled and uncontrolled responses are compared graphically. The numerical studies demonstrate the effectiveness of thermal environment, as well as the piezo-control of these thermal deformations using piezoelectric structures. It is found that the displacements caused by the temperature effects are important in the precision of piezo-control systems. [Copyright &y& Elsevier]

Abstract: Many applications involve actuated devices made of shape memory alloys, but the lack of efficient numerical tools hinders the development of such technologies. Software using a finite element method like ANSYS allows the user to predict complex responses of a system without extensive programming. In this paper, a homemade phenomenological 1D bilinear model is programmed through the USERMAT procedure in ANSYS. The model allows the representation of both mechanical and thermal hystereses. The martensitic transformation is controlled by transformation criteria similar to those used in conventional plasticity, and subcycles are modeled by a simple elastic return through the hysteresis. The model is validated through isothermal tensile testing, assisted two-way shape memory testing and stress generation testing, and a good agreement with experimental results is shown. Finally, thermomechanical response of a single-degree-of-freedom actuator is simulated as a typical application and a case study involving the shape change of a radio controlled aircraft wing shows the potential of the numerical simulations. [Copyright &y& Elsevier]

Abstract: Surface-bonded piezoelectric actuators can be used to generate elastic waves for monitoring damages of composite materials. This paper provides an analytical and numerical study to simulate wave propagation in an anisotropic medium induced by surface-bonded piezocermic actuators under high-frequency electric loads. Based on a one-dimensional actuator model, the dynamic load transfer between a piezoceramic actuator and an anisotropic elastic medium under in-plane mechanical and electrical loading is obtained. The wave propagation induced by the surface-bonded actuator is also studied in detail by using Fourier transform technique and solving the resulting integral equations in terms of the interfacial shear stress. Typical examples are provided to show effects of the geometry, the material combination, the loading frequency and the material anisotropy of the composite upon the load transfer and the resulting wave propagation. [Copyright &y& Elsevier]

This paper presents the effects of the torque model on the control of a variable reluctance spherical motor (VRSM) that offers several attractive features by combining multi-DOF motions in a single joint. A general form of the torque model for a VRSM is derived using the principle of energy conversion. The torque models for two specific design configurations developed at Georgia Tech are compared. The first has been based on an existing design characterized by a torque model in quadratic form. For feedback control of the spherical motor, the quadratic form of the torque model requires the use of nonlinear optimization schemes for computing the stator coil current inputs. The second design incorporating high coercive permanent magnets has a linear torque–current relationship and thus allows a closed form solution for both forward and inverse torque models. The effects of the torque model on a PD-controlled VRSM prototype has been studied both numerically and experimentally. Experimental results agree well with the computation derived analytically. [Copyright &y& Elsevier]

This paper discusses research carried-out by ALSTOM POWER on the development and validation (on laboratory scale plant) of an observer-based fault detection identification and accommodation (FDIA) system for an electromechanical actuator. Three separate linear observers (or Kalman filters) are used to detect and identify faults corresponding to the system''s three sensors. Having successfully detected a sensor fault, a reconstructed measure of that output signal (generated from an observer not associated with that sensor) is used to replace the measured signal for feedback control. This ensures that the system can continue to function effectively even after a sensor failure. The experimental results demonstrate that this approach could significantly enhance the post-fault availability of such systems. [Copyright &y& Elsevier]

[Display omitted] • One monolayer Janus bio-nanocomposite film with stimulus response is developed. • Janus structure and bonding intensity is obtained by incorporating nanocellulose into PVA. • Asymmetric structure, good mechanical properties, and water-resistance are realized. • Janus bio-nanocomposite film exhibits a smart and controllable responsiveness to salts. • Janus bio-nanocomposite film based actuators are controllably designed and explored. Stimuli-responsive materials have been increasingly explored to construct actuators and develop soft robots. Herein, one strategy via regulating lignin-containing cellulose nanofibrils (LCNF) distribution in PVA network followed by alkaline treatment (AT) and pre-stretching to fabricate bio-nanocomposite derived Janus films with stimulus response is proposed. LCNF/PVA-AT film displays obvious asymmetric structure, good mechanical properties, and water-resistance. Based on Janus structure and Hofmeister effect of PVA in salt solution, the applied pre-stretching treatment further enables the as-prepared LCNF/PVA-AT film with an excellently smart and controllable responsiveness to salt solutions. In addition, by adjusting some factors including length–width ratio of the film, salt type and concentration, the deformation degree and response/recovery time of LCNF/PVA-AT film and its based actuators can be controllably designed. The study will enrich the development of green, sustainable and biodegradable polymers derived Janus films, and expand their wide potential applications in multifunctional actuators. [ABSTRACT FROM AUTHOR]