Advanced ceramic materials offer enormous potential for innovations in the fields of efficient energy conversion and storage, sensor technology as well as environmental technology. The joint application of structural and functional ceramic technology allows for unique combination of electronic, ionic (electrochemical) and mechanical properties enabling the development of new, highly integrated systems. However, due to the brittle failure mechanism of ceramic materials the production of ceramic components requires nondestructive in-line testing. This is illustrated with specific examples for development for Fuel Cell, batteries and ceramic membranes.

Nature has created a vast array of biomolecules that enable living systems to interact with their environment and respond to external stimuli. One such class of biomolecule — stimuli-responsive ion channels — evolved early in our evolutionary history to enable passive cell membranes to become ‘active’, thus allowing organisms to survive environmental stress. Today we are utilizing these same biomolecules to make new types of sensors, actuators, and energy conversion devices that respond to mechanical stress, light, chemical gradients, and electrical gradients. We will discuss recent progress in the use of ion channels and transduction elements for smart materials, as well as several of the challenges that remain in fully harnessing these materials for engineering applications.

In this work we explore efficient transformation of broadband wave energy into low-power electricity using patterned polymer piezoelectrics integrated with an Elliptical Acoustic Mirror (EAM) configuration. Spatial and temporal transformation of the wave propagation field into the frequency-wavenumber domain is performed in order to identify the wavenumber content inside the mirror. Computational modeling and experimental testing are employed to quantify performance enhancement of the presented approach in the 20 – 120 kHz range. Various case studies demonstrate performance enhancement of signal amplification and increased piezoelectric power generation for various harvester topologies, design frequency ranges, and material impedances.

Hydraulic pressure energy harvesters are devices that convert the dynamic pressure within hydraulic systems into usable electrical power through axially loaded piezoelectric stacks excited off-resonance by the fluid. The pressure fluctuations coupled with the piezoelectric stack can be amplified by creating a housing design that includes a Helmholtz resonator tuned to the dominant frequency of the fluid excitation. The resistive losses within the system can also be used to increase the bandwidth of the resonance, thus increasing the utility of the device. This paper investigates the design, modeling, and performance of hydraulic pressure energy harvesters utilizing a Helmholtz resonator design.

Analytical and experimental multiphysics investigation of contactless acoustic energy transfer in fluid is presented for wireless applications. Incident ultrasonic pressure wave is coupled with the electroelastic dynamics of a thickness-poled piezoelectric receiver bar shunted to a resistive-reactive electrical load to quantify the extracted power output. Experimental validations are presented along with parameter optimization studies. Sensitivity of the electrical power output to the excitation frequency, source-to-receiver distance, and source-strength level are also reported. Resistive and resistive-reactive electrical loading cases are discussed for performance enhancement and frequency-wise robustness.

This article presents the possibility of energy scavenging (ES) utilizing the physics of acousto-elastic metamaterial and use them in a dual mode (Acoustic Filter and Energy Harvester), simultaneously. Traditionally acoustic metamaterials are used in filtering acoustic waves by trapping or guiding the acoustic energy, whereas this letter presents that the trapped dynamic energy inside the soft constituent (matrix) of metamaterials can be significantly harvested by strategically embedding piezoelectric wafers in the matrix. Upon validation of the argument through analytical, numerical and experimental studies, a broadband energy scavenger (ES) with multi-cell model is designed with varying geometrical properties.

Magnetorheological energy absorbers (MREAs) are used in vertically stroking crew seats to provide controllable stroking load to protect the lumbar spine during a high sink rate landing or crash. Existing passive energy absorber designs are optimally designed for a 50th percentile male occupant weight. Using an MREA, the stroking load can be adjusted to accommodate the allowable loads of occupants of varying weight (e.g. from a 5th percentile female to a 95th percentile male), as well as varying crash severity (sink rate). This study experimentally validates the design analysis and operational concept of the MREA for both vibration and shock mitigation problems.

In this study a flexible fluid transport system utilizing a soft magnetorheological elastomer (MRE) in its actuating valve element is investigated. A time-dependent fluid-solid interaction finite element model under magnetic load is developed for this study. The effect of the geometrical parameters, structural properties, fluid properties and magnetic properties on the performance of the system is analyzed. Results demonstrate the effect of various parameters on the fluid propulsion capabilities. The proposed system is able to achieve the desired flow rate, if the system parameters are properly selected.

In this contribution, a novel clutch for integration in a hybrid powertrain will be introduced. The clutch, whose transmission of power is based on magnetorheological fluids, uses a fluid control for enabling a drag torque-free operation in system failure situation. The fluid control with this well-defined fail-safe behavior is enabled by a sophisticated design of the fluid gaps and the magnetic circuit. Simulations and measurements with a realized prototype point out the suitability for integration in hybrid electrical cars that require a fast and reliable separation of electric motors and powertrain for ensuring safety and efficiency.

We investigate the feasibility of energy harvesting from axisymmetric vibrations of annular ionic polymer metal composites (IPMCs). We consider an in-house fabricated IPMC that is clamped at its inner radius to a moving base and is free at its outer radius. We propose a physics-based model for energy harvesting from underwater vibrations, in which the IPMC is described as a thin annular plate undergoing axisymmetric vibrations with an added mass due to the encompassing fluid. Experiments are performed to elucidate the effect of the shunting resistance and the excitation frequency on energy harvesting.

Macro-Fiber Composite (MFC)-based piezoelectric structures are employed for underwater mechanical base excitation and electrical biomimetic actuation in bending at low frequencies. Following in-air electroelastic model development, it is aimed to establish semi-analytical models that can predict the underwater dynamics of thin MFC cantilevers for different length-to-width aspect ratios. In-air analytical electroelastic dynamics of MFCs is therefore coupled with added mass and nonlinear hydrodynamic damping effects of fluid to describe the underwater electrohydroelastic dynamics in energy harvesting and actuation. Nonlinear dependence of the output power density to aspect ratio is characterized theoretically and experimentally in the underwater base excitation problem.

This paper investigates the feasibility of enhancing power conversion efficiency of galloping-based piezoelectric wind energy harvester (GPEH) by implementing synchronized switching harvesting on inductor (SSHI) technique. Wind tunnel experiment is carried out with the fabricated GPEH prototype, which consists of a bimorph cantilever and a square-sectioned bluff body. Electromechanical coupling strength is altered by varying electrical connections of the bimorph. Equivalent circuit model is established to conduct system-level circuit simulation. Experimental results confirm the simulation predictions that, given a realistic coupling strength, the power extraction process of SSHI dramatically improves the harvested power of GPEH compared to a standard circuit.

There have been a number of new applications for energy harvesting with the ever-decreasing power consumption of microelectronic devices. We explore a new area of energy harvesting for use on marine animal tags known as bio-loggers. Reduced solar irradiance below the water’s surface provides the impetus to explore other energy harvesting concepts. We investigate a novel source of energy for this application: hydrostatic pressure cycles during animal dives. We present initial testing results and show that sufficient energy could be harvested to power many bio-logging tags.

A new energy harvester, named FLEHAP (Fluttering Energy Harvester for Autonomous Powering), will be presented. The FLEHAP device is based on the fluttering effect: when a fluid in motion impinges on a structure, an amount of the mechanical energy can be transferred to the structure, inducing large amplitude oscillations if few mechanical parameters are correctly set. The FLEHAP device can operate in air (wind) and in flowing water. Two different approaches to convert the mechanical energy in electrical energy will be presented.

Optical fiber sensors are very useful to monitor the internal strain and temperature during manufacturing as well as in practical operations exposed to external loads. The authors have been using both multi-point and distributed strain monitoring techniques to characterize the structural integrity and quality control of advanced composite structures. This presentation first covers optical fiber based structural health monitoring (SHM) technologies for aircraft composite structures being conducted these ten years in Japan as national and international projects. Then, some recent developments on process and life-cycle monitoring (LCM) are presented as a promising method for intrinsic quality control of advanced composite structures with embedded optical fiber sensor systems.

This paper proposes a new class of multi-functional adaptive structure called fluidic origami. The idea is to connect multiple Miura folded panels along their fold lines into a cellular structure and then fill the space in-between with pressurized fluid of high bulk modulus. By exploiting the correlation between fluid volume and folding motion, fluidic origami can achieve actuation/morphing, stiffness tuning, and bi-stability autonomously. This concept combines the physical principles behind the plant nastic motion and the rich design variety of the origami art, thus it has the potential of fostering a new generation of high performance adaptive structures.

Piezoelectric-based hydraulic actuator is a hybrid device of a hydraulic pump driven by piezoelectric stacks which is coupled to a conventional hydraulic cylinder via a set of fast-acting valves. Nowadays, such hybrid actuators are being researched and developed actively in many developed countries by requirement of high performance and compact flight system. In this research, a piezoelectric hybrid actuator was designed and tested. To achieve bi-directional capabilities in the actuator, the commercial solenoid valves were used to control the direction of output cylinder. The experimental testing of the actuator in unidirectional and bi-directional modes was performed to examine performance issues related to the solenoid valves. The results showed that the maximum blocked force was measured by 826.0N when the frequency was 150Hz.

This paper presents the design and experimental analysis of a biomimetic robotic hand utilizing a new actuation system. The robotic hand is actuated by novel artificial muscles made of twisted and coiled nylon fibers. The proposed design employs symmetric pumping chambers for hot and cold fluids in order to actuate the artificial muscles and provide fast finger movements. In this paper, we investigate the design parameters that provide optimum performance, such as fast hand motion, high force generation, and controllable compliance.

In this research we explore utilizing internal resonances to realize harvesting vibratory energy generated by excitations from multiple directions with the usage of a single piezoelectric cantilever. Specifically, it is identified that by attaching a pendulum to the piezoelectric cantilever, 1:2 and 1:1 internal resonances can be induced based on the nonlinear coupling. Systematic analysis and experimental investigation are carried out to demonstrate this new concept.

This talk reports the study of an array of piezoelectric energy harvesters endowed with an SECE (synchronized electric charge extraction) interface circuit. The electrical performance of an SECE array system is analytically obtained and compared with the use of standard and SSHI (synchronized switch harvesting on inductor) interface circuits. It is found that the SECE circuit outperforms the other cases for the array systems with medium electromechanical coupling. Precisely, the SECE system not only exhibits better broadband energy harvesting but its harvested power is independent of the external load. The former provides bandwidth improvement and the latter gives advantage in the back-end interface design.

A novel method of nonlinear harvesting that embraces chaotic phenomena to improve operating bandwidth has been developed utilizing a piezomagnetoelastic beam. By ensuring strange attractor motion of the harvester, any of the unstable periodic orbits within can be stabilized through small perturbations of an accessible system parameter. This work aims to investigate OGY control through the piezoelectric material itself and test the algorithm on a wide range of input conditions. An experimental test stand will be used to verify the results, with maximum displacements and power outputs compared to other common harvesting configurations.

This paper investigates a diamagnetically stabilized horizontally levitated system for vibration energy harvesting in contrast to the diamagnetically stabilized vertically levitated system recently proposed. In this configuration, two large magnets, alias lifting magnets, are arranged co-axially at a distance such that in between them a magnet, alias floating magnet, is passively levitated at a lateral static equilibrium position. The levitation is stabilized in the horizontal direction by two diamagnetic plates made of pyrolytic graphite placed on each side of the floating magnet. This horizontal configuration mitigates some of the limitations imposed by the vertical configuration.

This paper reports a novel piezoelectric device, which achieves both energy harvesting and vibration suppression. Different from existing nonlinear energy harvesters, the proposed apparatus is based on the principle of nonlinear energy sink (NES). The apparatus comprises a fixed-fixed piezoelectric beam with a pair of central magnets, which act as NES mass and interact with a fixed magnet, providing essential nonlinearity. Simulation and experiment demonstrate that as long as the initial energy reaches the required threshold, the NES will be activated and energy is transferred to the NES efficiently. In this sense, the proposed energy harvester processes a wideband performance.

We investigate the use of bistable harvesters to extract energy from spinning wheels. The harvester consists of a cantilever beam carrying a tip mass in the form of a permanent magnet and mounted on a rigid spinning hub. Magnetic repulsion forces cause the beam to possess two stable equilibrium positions. Interwell lead-lag oscillations caused by rotation in a vertical plane offer a good source for energy extraction. The design also offers frequency tuning as the centrifugal forces strain the harvester, thereby increasing its natural frequency to cope with the rotational speed. This has applications in self-powered tire pressure monitoring sensors.

The Spanwise Morphing Trailing Edge concept allows for local camber variation of the trailing edge of a wing or control surface without altering the load-carrying spar box. Utilizing a modular design of active sections driven by Macro Fiber Composites with compliant mechanisms, spanned by inactive sections of elastomeric honeycombs, a continuous trailing edge control surface is created. The aerodynamic gains, energy requirements and mass distribution are experimentally evaluated for the SMTE concept for a representative finite wing and compared with conventional ailerons. The SMTE concept is shown to eliminate discontinuities and dramatically improve control over spanwise flow caused by vorticies.

There is currently an interest in developing semi-autonomous mobile sensing platforms that fly indoors. To perform this task the platform must have the ability to detect the presence of transparent barriers. These barriers could include windows, glass partitions, or skylights. For example, in order to successfully navigate inside of a structure, these platforms will need to sense if a space contains a transparent barrier and whether or not this space can be traversed. This project will focus on developing a multi-modal sensing system that can successfully identify such transparent barriers under various lighting conditions while aboard a mobile platform.

The aim of this paper is to present two control logics for UAV stabilization and remote piloting, that are as robust as possible to physical parameters variation and to impulsive or periodic external disturbances. Moreover, they are suitable for implementation on low-cost micro-controllers, in order to be attractive for commercial drones. A possible application of the two switching control logics could be facial recognition by means of a camera mounted on the drone: a low computational speed logic is used to reach the target, when a high stability one is activated, in order to complete the recognition tasks.

Tailless airplanes with swept wings rely on variations of the spanwise lift distribution to provide controllability in roll, pitch and yaw. Conventionally, this is achieved utilizing multiple control surfaces, such as flaperons, on the wing trailing edge. As every flight condition requires different control moments (e.g. to provide pitching moment equilibrium), these surfaces are practically permanently displaced. Due to their nature, causing discontinuities, corners and gaps, they bear aerodynamic penalties, mostly in terms of shape drag. Shape adaptation, on the other hand, has the potential of varying the lift of a wing section by deforming its profile in a way that minimizes the resulting drag. Furthermore, as the shape can be varied differently along the wingspan, the lift distribution can be tailored to the specific flight condition. For this reason, tailless morphing aircraft appear as a prime choice to apply morphing techniques, as the benefits obtained by morphing are potentially significant. In this work, we present a methodology to determine the optimal planform, profile shape, and morphing structure for a tailless aircraft. The employed morphing concept is based on a distributed compliance structure, actuated by Macro Fiber Composites. The multidisciplinary optimization is performed considering the static and dynamic aeroelastic behavior of the resulting structure, with the goal of maximizing the aerodynamic efficiency while guaranteeing the controllability by means of morphing, in a number of flight conditions. To exploit the potential of the resulting wing, the aerodynamic properties obtained by activating the various actuators in different combinations are assessed. The result is an envelope of control moments achievable, that identifies the optimal configuration for the actuators that results in the required control moments, while maximizing the resulting efficiency.

The methodology suggested in this research provides the great possibility of creating nanostructures composed of various materials, such as soft polymer, hard polymer, and metal, as well as Si. Such nanostructures are required for a vast range of optical and display devices, photonic components, physical devices, energy devices including electrodes of secondary batteries, fuel cells, solar cells, and energy harvesters, biological devices including biochips, biomimetic or biosimilar structured devices, and mechanical devices including micro- or nano-scale sensors and actuators.

During the last decade, hyper-redundant robots have been adopted in many applications such as the exploration of hardly accessible areas or the minimally invasive surgery. They are continuously curving manipulator with a very high number of sub-actuated dof. Requiring a precise and repeatable positioning system, they represent a challenge from the design and the control point of view. In this paper a 9 links (18 dof) continuum robot with 12 actuators is shown. Particular attention is paid to the end-effector. In order to enhance the robot performances, an EAP spring-roll actuator is designed as a support for a camera.

Magnetostrictive actuators can be profitably used to reduce vibration in structures. However, this technology has been exploited only to develop inertial actuators, while patches actuators have not been ever used in practice. This paper shows the design and the testing of an innovative magnetostrictive patch actuator.

This paper describes the application of monolithic folded pendulum sensors to the inertial control of multi-stage mechanical suspensions for seismic attenuation, of the same class of those used in interferometric detectors of gravitational waves, with requirement of 10−15 m/sqrt(Hz) in the band 0.01 ÷ 100 Hz. The experimental results in the band 0.01 ÷ 10 Hz demonstrate that this class of mechanical sensors has enough dynamics and sensitivity to introduce no limitations to control systems. Moreover, the full scalability of the sensors allows an easy integration and positioning also on the different stages of multistage mechanical suspensions (seismic attenuators) and inertial platforms. This new application demonstrates not only the feasibility of the proposed inertial control strategy in the low frequency region, but, and it is very relevant, that it is now possible the implementation of very effective state-of-the-art control systems with a large reduction of control electronics, replaced by less noisy optical and mechanical devices, with the further advantage of systems less sensitive to environmental noises. The results of this study, has also lead to develop a more general model for very different applications (platforms and mechanical structure control and stabilization, building controls, etc.).

This article considers a theoretical and experimental comparative analysis in the responses of a three-story building-like structure using two different schemes of passive vibration control. These control schemes are designed to reduce the effects of resonant vibrations generated by an electromechanical shaker located in the base of the building-like structure. The first control scheme consists on the design of a Tuned-Mass-Damper located over the third floor of the structure, and the second control scheme considers the implementation of an autoparametric cantilever beam absorber. The mathematical model of the overall system is obtained using Euler-Lagrange method. In order to validate the frequency response of the main system a finite element model is completed. Some numerical and experimental results are included to show the dynamic behavior and stability performance of the overall mechanical system.

Polyethylenedioxythiophene/alginate (PEDOT/Alg) hydrogel was used as a drug carrier/matrix to study the release of benzoic acid (BA) based on the effect of crosslinking ratio, PEDOT particle size, and electric field strength. The BA release was controlled by the Fickian diffusion. The diffusion coefficient (D) of BA decreased with increasing crosslinking ratio due to smaller mesh size of hydrogel. The D was higher under applied electric field because the electric field induced larger mesh size of hydrogel, reduction reaction of PEDOT, and electro repulsive force. The D was highest with the smallest PEDOT particle because of its greatest electrical conductivity.

Phenomenological model based on Bouc-Wen model can be used to effectively describe the nonlinear hysteretic behavior of MR dampers, but its structure is complex and the Bouc-Wen model is functional redundant. In this paper, based on the phenomenological model, (1) a normalized phenomenological model is presented using a “normalization” concept, (2) a Bouc-Wen transformed model is proposed and realized by adjusting the structure of the phenomenological model. In order to demonstrate, a modified genetic algorithm is utilized to identify the parameters of the normalized phenomenological model, Bouc-Wen transformed model, and phenomenological model.

In this work, a new type of MR brake featuring tapered inner magnetic core is proposed and its performance is evaluated. To achieve high braking torque with restricted size and weight, tapered inner magnetic core is designed and expand the area that the magnetic flux is passing by MR fluid-filled gap. After optimization of design parameters, finite element analysis is carried out to identify electromagnetic characteristics of the proposed MR brake. To demonstrate the superiority of the proposed MR brake, the braking torque of the optimized model is numerically evaluated and compared with that of conventional MR brake model.

In this paper, customizable microcontroller based circuitry for actuation of compact, lightweight robotic hand is presented with various gripping and grasping position. The hand, actuated by two different contractile actuators are compared and contrasted in a closed loop control system. MPLAB assembly language has been used to program the sequence of finger movement, ultimately loaded in PIC microcontroller based driver circuit. The closed loop control of the hand was achieved by controlling the shoulder Dynamixel-servos and Power HD servos with Pololu Maestro controller and Robotis CM700 controller.

This work deals with the robust asymptotic output tracking control problem of the tip position of a space frame flexible structure, mounted on a rigid revolute servomechanism actuated and controlled with a dc motor. The structure is also affected by undesirable vibrations due to excitation of its first lateral vibration modes and possible variations of the tip mass. The overall flexible structure is modeled by using finite element methods and this is validated via experimental modal analysis techniques. The tip position of the structure is estimated from acceleration and strain gauge measurements. The asymptotic output tracking problem is formulated and solved by means of Passivity-Based and Sliding-Mode Control techniques, applied to the dc motor coupled to the rigid part of the structure, and those undesirable vibrations are simultaneously attenuated by an active vibration control using Positive Position Feedback control schemes implemented on a PZT stack actuator properly located into the mechanical structure. The investigation also addresses the trajectory tracking problem of fast motions, with harmonic excitations close to the first vibration modes of the structure. The overall dynamic performance is evaluated and validated by numerical and experimental results.

In this paper, a design of a piezoelectric vibration energy harvester for low-frequency applications is presented. In this design, a unit cell consisting of an elastic frame and a piezoelectric cantilever oscillator with a plucking mechanism is developed. Since the plucking mechanism acts as a mechanical switch, the elastic energy accumulated in the unit cell during the loading phase does not return back to the environment but remains inside the unit cell as the mechanical energy of the free vibration of the cantilever, which can be retrieved as electric energy by a high efficiency interfacing circuit.

In this paper, a new sensor-less parameter estimation method is proposed for electromagnetic shunt damping. The purpose is to estimate parameters of an electromagnetic transducer and a vibrating structure. The frequency domain measurements of an electrical admittance are only supposed to be available but any other sensor measurements are not; therefore, the estimation problem is nontrivial. Two types of numerical optimization, a linear optimization to select an initial seed and a nonlinear optimization to determine a final estimate, are presented. The effectiveness of the method is demonstrated by vibration control experiments as well as parameter estimation experiments.

This paper is aimed to investigate on a coupling system consisting of a bistable oscillator with an elastic magnifier (EM) to improve the output performances in vibration energy harvesting. Nonlinear equations of the coupling system were derived to describe the broadband large-amplitude periodic displacement responses. The effects of the mass and stiffness ratios on were studied. It has been shown that increasing the mass and stiffness ratios can improve the system output performances. It was validated from experiments that the coupling system can harvest more power in low excitation level with larger bandwidth as compared to the bistable oscillator without an EM.

The analysis of a control system for a semi active rear suspension in an off-road 2-wheel vehicle is performed. Several control methods are studied. An experimental semi-active suspension model is used as software in the Loop. This model includes an Electro-Hydraulical damper. The test motorcycle dynamics, as well as the passive suspension are simulated into BikeSim, a professional two-wheeled vehicle simulation software, The semi active suspension and the algorithm are co-simulated in Matlab/Simulink/BikeSim. The design of experimenst is based on several off-road conditions. The results shows an effective road holding when using a semi-active suspension for off-road competitions purposes and, more over, it is improved by the inclusion of the lever ratio in control law computation.

A magnetorheological (MR) damper can adapt its dynamic performance to the vibration environment by controlling the current applied. Compared to other types of dampers, the MR damper has a wider range of dynamic characteristics. Two different dampers: hydraulic, and MR dampers were tested under forced sinusoidal excitations of low to high frequencies. Also, different currents were applied on the MR damper to investigate its performance under varying electromagnetic fields. The results reveal that the two dampers have nonlinear dynamic characteristics and that characteristics of the hydraulic damper are different from those of the MR damper. The hydraulic damper provides slight nonlinear damping force whereas the MR damper shows a strong nonlinear property. In addition, the hydraulic damper is designed to provide an asymmetric damping force of rebound and compression whereas the MR damper provides a symmetric damping force. In the experiments conducted, the excitation frequency was varied from 3 Hz to 11 Hz and the amplitude from 2.5 mm to 12 mm. For the hydraulic damper, the lowest compression damping force only increases by about 0.54 kN while the rebound force increases by about 1.9 kN. In contrast, the variations of compression and rebound forces of the MR damper are 1.9 and 2.0 kN, respectively. Furthermore, the damping force of the MR damper increases as the current increases from 0 to 0.75 A.

A new lead-zirconium-titanate (PZT) actuator design for a micro scanning light source is being developed. The thin PZT film is deposited directly on stainless steel by using an aerosol deposition machine. The aerosol deposition method enables low-cost, quick, room temperature fabrication while producing high {3-1} mode piezoelectric constants. This research also aims to investigate if steel based actuators will yield a higher angular deflection in the waveguide. These scanning devices would be attractive for endoscopic device applications, where inexpensive systems at no cost in resolution would move toward having disposal endoscopes.

The application of wave-based inspection methods for the analysis of the state of health of structural components has received significant attention in recent years.The propagation and GUW, together with the application of Scanning Laser Vibrometry for full wavefield measurement enables the introduction of novel damage detection techniques which are based on the application of filtering techniques in the frequency/wavenumber space. Goal of these techniques is to separate the contribution of damage from the overall response of the structure, thus highlighting its presence and location. This presentation will provide an overview of techniques developed for the analysis of guided wavefield, and their application for damage detection, structural characterization, and for the design of novel transducers for Structural Health Monitoring. These transducers feature patterns that enable wave steering through the selection of the excitation frequency, and the measurement of multiple strain components for surface acoustic wave-based sensing of strain.

This is a review of the state of the art in piezoelectric-based electrical energy harvesting methods and devices, including their charge collection electronics, for use in munitions. The review will concentrate on devices to harvest energy from the launch and flight environments of gun-fired munitions. In particular, this study reviews the various methods of utilizing such energy harvesting devices to address power and energy requirements of munitions using a systems approach to the management of power and energy. The performance of current munitions and the development of future munitions are limited by the size and energy constraints of existing power sources. The methods of extracting energy from the launch and flight environments can be applied to almost all munitions, missiles and rocket systems and can strengthen the industrial base for tactical military power sources.

Vibration-based energy harvesting using a disk-type piezoelectric bimorph with thickness poled circular piezoelectric laminates is explored theoretically and experimentally. The bimorph disk consists of two circular laminates electrically connected in series and shunted through the outer surface electrodes to an electrical load for characterizing the power output and piezoelectrically shunted vibration in response to base excitation. The bimorph disk with free edge conditions is mounted to the vibrating base from its center and the focus is placed on the fundamental axisymmetric vibration mode. Experimental validations of the electroelastic model are given for two separate PZT-5A bimorph disks of different diameters.

This paper is an in-depth study on piezoelectret foam assembled in a multilayer stack configuration and presents results of the stack behavior when excited at low frequencies. In this work, modeling and experimentation is done to investigate piezoelectret foam as a multilayer energy harvester. After a review of the past modeling, an assessment is made between those models to deduce which one is most applicable to this experiment. Electromechanical testing is performed by compressing the foam stack to obtain output electrical energy; consequently, allowing a relationship between input mechanical energy and output electrical energy to be developed.

A force-compensated hydrogel-based pH sensor was presented in this paper. Compared to the conventional deflection type sensors, the implementation of the compensation method increases reproducibility as well as reduces response time. Firstly, pH-sensitive PVA/PAA and temperature-sensitive PNIPAAm were synthesized and characterized. Then low temperature liquid encapsulation of the hydrogel components in the corresponding cavities by using epoxy H70E-2 was investigated. The temperature distributions of this sensor were evaluated by thermal simulation. The response time of this sensor was a fifth of that of deflection type sensor. The time-dependent output signal drift was significantly decreased.

The performance of the wireless transceivers rigorously depends on the performance of its first block T/R switch. This article proposes a design of a high performance T/R switch for 2.4 GHz RF wireless transceivers in 130 nm CMOS technology. The switch exhibits 1- dB insertion loss, 37.2-dB isolation in transmit mode and 1.4-dB insertion loss, 25.6-dB isolation in receive mode. The switch has a power handling capacity (P1dB) of 30.9-dBm. Besides, by avoiding bulky inductors and capacitors, the size of the switch is drastically reduced and it occupies only (0.00296) mm2, which is the lowest ever reported in this frequency band.

This study investigates the bond behavior between SMA bars and concrete through pull-out test. To explore the size effect on bond strength, the tests are performed using various diameters of SMA bars. For the same diameter, the tests are also conducted with different embedment length to assess the effect of embedment length on bond properties of SMA bars. To monitor the slippage of the SMA reinforcement, an optical Digital Image Correlation method is used and the bond-slip curves are obtained. Results from experimental tests of SMA bars are compared with the reported bond strengths of other types of reinforcement with concrete.

Shape memory alloys are known as actuators with very high energy density. This fact allows for the construction of very light weight and energy-efficient systems. In material handling technology, this trait is essential, because high inertial forces have to be avoided in kinematic units and robots. In this paper, a SMA-based gripping system is developed and prototypes are constructed and evaluated. The system uses SMA-actuated vacuum suction cups to grip and hold objects without using compressed air or vacuum pumps. The system further is adaptive and changes its configuration according to the work piece geometry. No additional sensors are needed in this system as the self-sensing ability of SMA wires can be used.

To keep a position of SMA actuators, they must keep being heated. To save the energy, an antagonistic SMA system is considered, where any position can be an equilibrium point within hysteresis of stress-strain diagrams. To confirm a feasibility of the system, a fundamental experiment is performed. When a series of pulse whose amplitude increases gradually is applied to one SMA wire, the equilibrium position changes like a staircase. However, just after the pulse the position returns slightly. To investigate such a behavior of the system, numerical simulation is also performed.

Self-tuning parts in a prototype of an Erhu instrument using shape memory alloys are designed and developed. Erhu, a tradition Asian music instrument with two strings can be automatically and precisely tuned by controlling SMAs. SMA springs connected with two strings can be deformed when a current is passed through them, resulting in the stiffness change of strings. Therefore, the pitch of the Erhu prototype will be changed. The body of the Erhu prototype is manufactured by a 3D printer, with a portable power supply and a control circuit imbedded.

This paper presents experimental and theoretical components of a novel metamaterial-inspired vibration suppression system. The proposed research takes advantage of uniquely designed cantilevered zigzag structures that can have natural frequencies orders of magnitude lower than a simple cantilever of the same size. Another key aspect of the proposed vibration suppression system is that the dynamic response of each zigzag structure can be made highly nonlinear with the use of magnets. Arrays of these compact nonlinear zigzag structures are integrated into a host structure to form what is referred to here as a metastructure. Experimental modal analysis results will be shown comparing the response of the full nonlinear metastructure to those of both an equivalent linear metastructure and also an equivalent host structure with no vibration suppression.

When looking at piezoelectric multimodal damping, a solution consists in connecting a structure to its electrical modal equivalent. This extension of the tuned mass damper strategy is applied by obtaining the electrical network being the discrete analogue of the continuous mechanical structure. The two media are connected through a periodic piezoelectric array which transfers energy to the electrical damping elements. This network strategy stands out from the independent resonant shunts because of its broadband capabilities and the possibility to design a completely passive system. This is shown numerically and experimentally by the study of longitudinal and transverse wave propagation in one-dimensional electromechanical structures.

Smart fiber placement is an ambitious topic in current research for automated manufacturing of large-scale composite structures. To obtain a high degree of observability and controllability of the manufacturing process, an adaptive system has been developed to be integrated into the fiber placement head. It decouples the compaction roller from disturbances and axially adapts the position of the compaction roller. Therefore, the compensation of vibrational issues and material failures are key challenges to significantly increase the production rate with no loss in accuracy. This paper investigates the behavior of the adaptive system to compensate static and quasi-static deviations of the desired path.

Two Piezo-Based Rotating Inertial Actuators (PBRIAs) are considered for the suppression of structure-borne noise radiated from rotating machinery. Each inertial actuator comprises a piezoelectric actuator shunted with the Antoniou’s gyrator circuit. This type of electrical circuit can be used to emulate a variable inductance. By varying the shunt inductance it is possible to realise two tuneable vibration neutralisers in order to suppress single frequency vibrations of slowly rotating machines. As the PBRIAs can be directly mounted on the shaft, reductions in the sound radiated from the machine housing can be achieved by suppressing the disturbance force transmitted to the housing.

In this paper, a design of a piezoelectric vibration energy harvester for low-frequency applications is presented. In this design, a unit cell consisting of an elastic frame and a piezoelectric cantilever oscillator with a plucking mechanism is developed as a building block. Since the plucking mechanism acts as a mechanical switch, the elastic energy accumulated in the unit cell during the loading phase does not return back to the environment but remains inside the unit cell as the mechanical energy of the free vibration of the cantilever, which can be retrieved as electric energy by a high efficiency interfacing circuit.

This paper provides an integrated design approach for piezoelectric energy harvesting systems with a focus on mechanical design, when different interface circuits are utilized. Different piezoelectric cantilevers are customized according to the selection of either standard energy harvesting (SEH) or synchronized switching harvesting on inductor (SSHI) interface circuits under the same harmonic vibration and power demand. The nonlinear interface circuits are modeled as complex impedances, thus can be integrated into the mechanical models for systematic studies. Both theoretical and experimental results show that, compared to using SEH, adopting SSHI enables a significant shrink on the physical size of the system.

Electroelastic and dissipative nonlinearities of commonly used soft piezoelectrics (PZT-5A and PZT-5H) are pronounced in various engineering applications such as actuation, sensing, vibration control, and most recently, in energy harvesting from dynamical systems. The present work investigates the nonlinear nonconservative dynamic behavior of bimorph piezoelectric cantilevers under low-to-high mechanical and electrical excitation levels with a focus on most popular soft piezoceramics: PZT-5A and PZT-5H. A unified mathematical framework we recently developed is analyzed by using the method of harmonic balance to identify and validate the nonlinear and dissipative system parameters based on a set of rigorous experiments for different samples.

A flat-shaped rotary MR brake is designed as part of the powered knee orthosis to provide adjustable resistance. The MR brake adopts multiple disk structure with interior inner coil and a novel smooth transition surface between core shaft and side plates. Based on this design, a parameterized model of the MR brake is built for geometrical optimization. Multiple factors are considered in the optimization objective: braking torque, weight, and average power consumption. As a result, the optimal design is obtained with maximal braking torque 35 Nm, total weight 0.56 kg and average power consumption 7.2 W. Trade-offs between design objectives are also investigated.

This study addresses how valve wall surface roughness affects performance of a magnetorheological energy absorber (MREA) under high-speed impact. An accurate prediction of viscous force at high piston velocity is critical for predicting MREA performance over the full range of impact velocity and payload mass. A previously derived Bingham Plastic Model (BPM) was modified to incorporate a rough valve wall to more accurately capture the sharp increase in viscous force at high Reynolds number. The new model, which assumes constant Darcy friction factor, is shown to match more closely to the data gathered through MREA drop tests.

This paper proposes a driver assistance device to notify drivers an optimal gear shifting timing considering fuel consumption in manual transmission vehicles. The haptic cue function of the proposed device is utilizing magnetorheological (MR) clutch mechanism as haptic interface. The manufactured MR clutch is integrated with accelerator pedal on which driver’s foot is placed. A gear shifting cue algorithm is formulated and integrated with haptic cue controller which is a torque model based-compensation strategy regarding Presiach hystersis linearization of the employed MR fluid. Haptic cue control performances are experimentally evaluated such as haptic tracking responses, cue timing and fuel consumption.

The prosthetic includes three components: thigh, knee and shin. An arrangement of SMA wires inside the thigh provides actuation to the shin. The rotary knee is equipped with a MR fluid brake to provide high holding torque at low current and energy consumption. The shin contains all the controlling electronics and battery. The use of SMA wires and MF fluid brake make this prosthetic leg consume less energy and provide more features in comparison with the use of regular electric motors. The prosthetic leg was fabricated and tested. The experimental data was compared with the predictions from theoretical simulation.

Flexible systems are often designed to undergo large deformations allowing for various shape reconfigurations. Thin beams integrated with piezoelectric layers or patches are one of examples of smart flexible structures. This study deals with nonlinear large deformation analysis of a thin beam with multiple piezoelectric patches attached on its top and bottom surface. The beam undergoes large deformations due to electric actuations by attached patches and mechanical actuation by external force. Analytical and numerical solutions are derived by adopting Reissner’s large-displacement finite-strain beam theory and nonlinear shooting method. At the end, it is shown that by controlling some independent variables like location of patches and magnitude of applied electric field desired deformed shapes for such beams can be achieved for industrial purposes.

Power source is critical to achieve independent and autonomous operations of electronic mobile devices. The vibration-based energy harvesting is extensively studied recently, and recognized as a promising technology to realize the inexhaustible power supply for small-scale electronics. Among various approaches, the piezoelectric energy harvesting has gained the most attention due to its high conversion efficiency and simple configurations. However, most of piezoelectric energy harvesters to date are based on the bending-beam structures and can only generate limited power with narrow working bandwidth. The insufficient electric output has greatly impeded their practical applications. In this paper, we present an innovative lead zirconate titanate (PZT) energy harvester, named high-efficiency compressive-mode piezoelectric energy harvester (HC-PEH), to enhance the performance of energy harvesters. A theoretical model was developed analytically, and solved numerically to study the nonlinear characteristics of the HC-PEH. The results estimated by the developed model agree well with the experimental data from the fabricated prototype. The HC-PEH shows strong nonlinear responses, favorable working bandwidth and superior power output. Under a weak excitation of 0.3 g (g = 9.8 m/s2), a maximum power output 30 mW is generated at 22 Hz, which is more than ten times better than current energy harvesters. The HC-PEH demonstrates the capability of generating enough power for most of wireless sensors.

Unwanted accretions on structures are a common machinery maintenance problem, which can pose a serious safety threat if not treated effectively and punctually. In this paper we investigate the concept of employing piezo-excited structural waves to invoke delamination in waveguides with accretion. We apply a wave-based technique for modelling piezoelectric excitation based on the semi-analytical infinite elements to model the interface shear stress associated with piezo-actuated structural waves. As a proof of concept, we present a demonstration experiment in which the patches of a model material are removed from a beam-like waveguide with emulated anechoic terminations using ultrasonic excitation.

This paper proposes a 3-DOF Hierarchical Compact Piezoelectric Tripod Manipulator (HCPTM) actuated by piezoelectric stack actuators. we developed the HCPTM having a workspace with a rotational angle of 1.2° and linear stroke of 562μm. Applying butterfly-shaped amplification mechanisms designed using kinematic model and FEM analysis to amplify the limited strain of the stack actuators, the three actuation linkages of the tripod have an effective strain which exceeds 2.3%. By using the three actuation linkages which is compactly cross-stacked with the amplification mechanisms, proposed HCPTM is also miniaturized to fabricate and has capacity to be utilized in small-scale applications. The total height and radius of the HCPTM are 56.0 mm and 24.3 mm, respectively and the weight is only 115g.

This paper presents an electromechanical modeling of a piezoelectric bimorph actuator with rigid extension, considering the non-linear behaviour of piezoelectric material at high electric field. The analysis considers the second order constitutive equations of piezoelectric materials assuming the strain is small and the electric field is large. The paper contains analytical formulation and derives different performance measuring attributes of this actuator. Analytical modeling shows that values of output energy, energy density and energy efficiency become maximum for certain geometry, and beyond that their values decrease. Thereby, we perform a multi-objective optimization to achieve optimal geometry of the actuator for maximum output energy, output energy density and energy efficiency. This optimal design limits the length of the rigid extension. The analysis considers both series and parallel electrical connection for the results.

A piezofan is a resonant device that uses a piezoceramic material to induce oscillations in a cantilever beam. Piezofans are popular as a very compact, low power, noiseless air cooling technology for portable electronic devices such as cellphones, DVD players, laptop computers, automobile multimedia boxes etc. Uncertainties are associated with the piezoelectric structure due to several reasons such as variation during manufacturing process, temperature, presence of adhesive layer between the piezoelectric actuator/sensor and the shim stock etc. Presence of uncertainty in the piezoelectric materials can influence the dynamic behavior of the piezoelectric fan such as natural frequency, tip deflection etc. These quantities will also affect the performance parameters of the piezoelectric fan such as electromechanical coupling factor, flow velocity, cooling rate etc. Probabilistic analysis provides a tool for incorporating structural uncertainties of the material properties in the analysis of the structure by generally describing the uncertainties as random variables. In the present study, uncertainty analysis is performed using classical Monte Carlo Simulation (MCS). The MCS is one of the most popular non-intrusive uncertainty analysis techniques that can be performed without any modification or approximation of the governing equations. Furthermore, the growing power of computers has made MCS possible for many engineering problems. In the full paper, structural model used for dynamic analysis of a piezofan will be presented. Full paper will also show the influence of the uncertainties associated with the piezofan structure on the dynamic behavior of the piezoelectric fan.

Sensors and actuators are the basic building blocks of smart structures. In the smart sensors portion of the presentation, examples of wireless sensing, thin-film flexible multiplexed sensor arrays, and printed sensors development will be emphasized. As an example of actuator development, a piezohydraulic actuator will also be included in the presentation. Through these examples, the difference between system level requirements or base technologies push driven development will be discussed. The technology development portion will include academic research as well as industrial development. The emphasis will be on taking a concept to prototype. Talk will be concluded by reflecting on challenges and opportunities for a small company like NextGen Aeronautics in developing a commercially viable product.

In this work, nano-transducers with the superparamagnetic iron oxide (SPIO) core have been synthesized by the preparation of precursor gold nonoseeds loaded on SPIO-embedded silica to form a gold nanoshell. The goal is for such nano-tansducers to be used in theranostics to detect brain tumors by using MRI imaging and then assist in their treatment by using photothermal ablation. The iron oxide core provides for the use of a magnetic-field to guide the particles to the target (tumor) site. The gold nanoshell can be easily heat up under incident light and/or alternating magnetic-field After synthesis of nano-transducer samples, Transmission Electron Microscopy was employed to analyze the formation of each layer [1]. Then, UV spectroscopy experiments were conducted to examine the light absorbance of the synthesized samples [2]. The UV-visible absorption spectra shows a clear surface plasmon resonance (SPR) band around 530 nm, verifying the presence of gold coating nanoshells. Finally, photothermal experiments using a high-power laser beam with a wavelength of 527 nm were performed to heat up the samples. It was found that the temperature reaches 45 oC in 12 minutes. Reference 1. Masoumi, M., Wang, Y., Dong, E., and Liu, M., 2015, Superparamagnetic Iron Oxide Nanoparticles with Gold Nanoshell: Synthesis and Characterization, International Conference on Advances in Functional Materials, June 29 –July 3, 2015, Long Island, NY. 2. Masoumi, M., Wang, Y., Dong, E., Longtin, J., and Tewolde, M., 2015, Multifunctional SPIO-Gold Nanoshells Conjugated with Cetuximab for Brain Cancers, International Conference on Advances in Functional Materials, June 29 -July-3, 2015, Long Island, NY.

Adaptive Noise Blocker is a system under development that will be mounted inside a window-opening to reduce the transmission of noise. The system consists of ten microphones, four loudspeakers, a Rapid Control Prototyping (RCP) and analog filters. The latter introduce a delay decreasing the performance of the feedback control. A computational efficient active noise control algorithm allows the RCP to operate at high sampling frequency. Herewith the usage of analog filters with high corner frequency is enabled which leads to less delay. A feedback delay-less partitioned block frequency-domain adaptive filter is implemented on a multitasking RCP.

Traditional aeroelastic models for wind tunnel tests rely only on good mechanical design and accurate crafting in order to match the required structural properties. This paper proposes an active regulation of their mechanical parameters in order to improve the accuracy and reliability of wind tunnel tests.

This paper presents a multiphysics Finite Element Analysis of an Electromagnetic Damper in which the thermal domain is integrated with the electromagnetic and mechanical domains. The influence of the temperature on the device parameters and overall performance in the operative temperature and frequency ranges of a space mission is shown. The outcomes of this parametric analysis are then included in the design optimization of an electromagnetic shunted damper for 5-kg single-degree-of-freedom system to obtain a maximum dissipated power of 7 Watts. The analytical results are compared with the typical transfer function of a viscoelastic material

We have studied the performance of semi-active vibration suppression by using piezoelectric patch, called as SSDI, is investigated and optimized from a viewpoint of practical application to satellite structures. Previously, the authors have experimentally demonstrated that　the performance in suppressing the vibration heavily depends on the configuration of electrical connection for these devices. In this paper, we show that a mathematical model of the characteristics of piezoelectric patches and inductors is established as a function of frequency based on measured data. And the optimal resource allocation of the patches and inductors is analytically derived based on this verified mathematical model.

Vibration of piezolaminated beams with extension and shear mode piezo actuators subjected to electromechanical loading is studied. A finite element eight node isoparametric element is adopted in the formulation with higher order shear deformation theory. Constitutive law for piezoelectric is considered. In case of the extension actuation mechanism, top and bottom layers of beam are of PZT-5A piezoelectric material and the central core is of Aluminum. Whereas, in case of shear actuation mechanism, top and bottom layers are of Aluminum and the central core is provided with a small patch of PZT-5A piezoelectric material and the rest of the core is a rigid foam material. Frequencies obtained by using present methodology are presented for both extension as well as shear actuation mechanism of piezoelectric material.

The work presented in this paper includes experimental and theoretical results for an energy harvesting device with the capability to power a structural health monitoring system. This device is a unique adaptation of a previously published zigzag magnetoelastic energy harvester that will be usable in a variety of applications. The proposed research introduces a zigzag geometry beam used in conjunction with a magnetic field to create a device capable of integrating with a self-powered wireless sensing platform. This platform will combine broadband energy harvesting, highly efficient power generation, and control electronics to provide self-powered sensing functionality and wireless transmission capabilities in a compact device. Experimental results will be shown comparing both the linear and nonlinear harvesting and transmission capabilities of the energy harvesting device.

In this study, authors have proofed the feasibility of the wireless measured vibration data transmission for a vibration condition monitoring system powered by the vibration energy harvester. It uses a commercial LTC3588 energy harvesting chip and the piezo-bimorph cantilever-type energy harvester. The total power consumption of the vibration sensor and wireless device is over 60mW. The developed system was able to measure the vibration acceleration of approximately 2 seconds under the vibration input of 0.013G (RMS) at approximately 56Hz every 26 minutes. The experimental results successfully demonstrated the feasibility of the developed system powered by the vibration energy harvester.

A hybrid rotary-translational vibration energy harvester is investigated with the goals of increased output power and robustness. A new double coil configuration shows a ~34% increase in peak output power, 167 mW to 223 mW, from a 5.4 Hz, 500 mg host acceleration. An improved peak power density of 7 mW/cm3 is observed for the double coil device, compared to a power density of 5.5 mW/cm3 for the original single coil variant. The root-mean-square power is increased from 35 mW to 39.7 mW. A laboratory demonstration of the harvester is described - an autonomous self-powered acceleration measurement (SAM) device.

The targeted energy transfer from a linear oscillator to an attached ground nonlinear oscillator is investigated. The nonlinear oscillator functioned as an energy sink, consisting of a nonlinear spring exhibiting bistability. Numerical studies elucidate the effect of bistability on the overall system performance. The studies focus on energy transfer from the linear oscillator to the nonlinear bistable energy sink (BES) subject to impulse excitation. In general, the results show BES exhibits more efficient damping characteristics for a wider input excitation energy level. This model has been used to study an acoustic resonator and its dissipation. The results may indicate a new acoustic dissipation mechanism.

The choice and fabrication of point-wise properties in a gradient design allows for more sophisticated objectives in active and passive smart dynamic structural systems. For example by \creating a non-reflective layered structure, two parts of a dynamical system may be vibrationally isolated. Here a mathematical technique for design of non-reflective media based on the conversion of the wave equation of a heterogeneous medium, in potential form, to a homogeneous one is presented. For a particular set of layered designs, the equivalent potential results in no scattering. Therefore, such a layered design is in fact non-reflective.

In this paper, a new seismic energy dissipation shear wall structure is proposed. The new shear wall is one with build-in vertical slits with the wall panel, and steel dampers are installed in the vertical slits so that the seismic performance of the structure can be controlled. Moreover, the steel damper is easy to be replaced in post-earthquake events. The proposed steel damper is with a serial of diamond-shaped holes and designed based on the lateral deformation of the shear wall. The yielding scheme of the steel damper is proposed in order to achieve the ductility and energy dissipation demand of the shear walls. The mechanical model of slotted concrete shear wall is established. Finally, the numerical simulations of the slotted RC shear wall based on the finite element software ABAQUS are presented to validate the effectiveness of the proposed mechanical model.

Piezoelectric-based energy harvesting has been researched extensively over the last few decades, however the behavior of energy harvesting systems is rarely studied under transient conditions. This paper works to develop understanding of this behavior. Of particular interest is implementing a vibration reduction technique, resonance frequency detuning, which aims to limit mechanical response at structural resonances as the excitation frequency sweeps through a given range. Useful correlations between vibration properties and energy harvesting behavior will be investigated, with the intent of determining a method of using the harvested energy as a proxy for vibration to implement in resonance frequency detuning.

A coupled oscillating system with 2-degree of freedom is capable of efficiently harvesting energy from two dominant frequencies. The design presented in this paper uses a spring mass-damper system with non uniform magnetic field. The multi-physics finite element software Comsol is used to investigated (i) coil phase, (ii) coil placement and (iii) high permeability material for magnet separation. A prototype was developed to demonstrate that practical amount of power can be generated from the design. It can be shown that 212 mW and 218 mW can be generated from sinusoidal vibration with 0.4 g peak acceleration at 6.5 Hz and 14.5 Hz respectively.

To realize a six-degree-of-freedom (six-DOF) piezoelectric energy harvester, which has six sensitive axes and broader bandwidth, a single-DOF piezoelectric energy harvester utilizing a clamped beam configuration is proposed in this paper. The motion equation of the single-DOF piezoelectric energy harvester is established and analyzed. On this basis, the natural frequency and stress distribution of the harvester are investigated through analytical developments and numerical simulations. The experimental results show that the proposed single-DOF vibration energy harvester is effective and the natural frequency and stress distribution can be accurate estimated by the established theoretical models.

This paper proposes a piezoelectric energy harvester for six-degree-of-freedom (six-DOF) vibration energy harvesting utilizing a six-DOF parallel mechanism with cubic configuration. Compared to the conventional energy harvester, the proposed six-DOF vibration energy harvester has six sensitive axes and broader bandwidth for the proper designed six adjacent natural frequencies, so higher efficiency of energy harvesting can be expected. To investigate the characteristics of the proposed energy harvester, analytical developments and numerical simulations on its natural frequency and modes of vibration are carried out. The experimental results show that the proposed six-DOF vibration energy harvester has higher output voltage and its bandwidth is broader than the conventional single-DOF one.

A passive control methodology to increase the seismic safety of multi-drum columns is presented. The response of a large scale column-model is investigated experimentally under dynamic excitations. A particle damper is used to replace one of the column's original drums. The influence of the system parameters on the response of the column is also examined. It is found that the seismic response of the column can be considerably reduced if a particle damper replaces a drum above the mid-height. Guidelines and a design methodology are proposed to restore and protect monumental structures.

The paper introduces the use of Fiber Bragg Gratings (FBG) sensors, to increase the reliability of feedback measurements in smart structures designed to actively control vibration when failures on sensors happened. Theoretical results are supported by experimental tests on a large flexible system made of a thin cantilever beam with 30 longitudinal FBG sensors and six piezoelectric actuators (PZT).

A relatively unexplored field of the shape memory technology is the area of rotary actuators, especially for generating continuous rotations. This paper deals with a novel continuous rotary motor based on SMA wires and overrunning clutches which features high output torque and boundless angular stroke. The concept uses a SMA wire wound round a low-friction cylindrical drum. Fitted to the output shaft by means of an overrunning clutch the output shaft rotates unidirectionally despite the sequence of contractions-elongation cycles of the wire. A six-stage miniature prototype is tested showing excellent performance in terms of speed and power density.

A prototype of information indicator based on two-way SMAs and 3D printing technology is proposed. This cubic information indicator including SMAs, Polydimethylsiloxane, a sensor and a control circuit will deliver different information. When the sensor receives a signal, the circuit will drive the current going through one or more SMAs which will be deformed. As a result, the information indicator will be deformed to a customized shape which depends on personal definition. It will go back to the original shape quickly when the current is off. The prototype can notify users through either vision or haptic interface.

We propose two frameworks for the derivation of constitutive models for solids undergoing phase transformations. As an application, a schematic model is derived for an idealized shape memory alloy and used to obtain a novel analytical solution for the problem of semi-infinite mode III crack in this material. The derivation of the analytical solution uses the hodograph method to map Cartesian coordinates into the hodograph plane. The resulting boundary-value problem for the mode III crack considered becomes analytically tractable for the idealized shape memory alloy considered and leads to closed-form expressions for the displacement and phase volume fraction fields near the crack tip as well as for the boundaries between different phase regions.

Three dimensional isolation technology was proposed several years ago. However, traditional 3-D isolators still have some problem, such as difficult fabrication or little energy dissipation along vertical direction. This paper presents a novel 3-D isolator made up of martensitic shape memory alloy wires. Mechanical properties of 3-D shape memory alloy pseudo-rubber isolator (SMAPRI) are investigated including compression, and compression-shear loading with different frequencies and amplitude. Experimental results indicated that 3-D SMAPRI has good mechanical properties and energy dissipation ability along both of horizontal and vertical direction, so it has good potentiality in both of seismic isolation and industrial isolation.

Abstract: Shape memory alloys (SMA) are a unique class of materials which have ability to undergo large deformation and also regain its undeformed shape by removal of stress or by heating. This unique property could be effectively utilized to enhance the safety of a structure. This paper presents the pushover analysis performance of a Reinforced Concrete moment resistance frame with the traditional steel reinforcement replaced fully or partially with Nickel-Titanium (Nitinol) SMA. The results are compared with the RC structure reinforced with conventional steel. Thus the result shows that RC structure reinforced partially with shape memory alloy shows better performance. Keywords: shape memory alloys, reinforced concrete frame, pushover analysis, performance

An adaptive vibration control is proposed to improve the fatigue life of a carbon-epoxy smart structure. The control logic prevents crack nucleation in the healthy structure, switching to the inhibition of further crack propagation when damage is detected by an online vibration-based diagnostic tool. The controller is periodically adapted to consider damage-induced changes on the structure model and give emphasis to the most excited modes. To limit the total number of sensors, a multilayer perceptron extends online the mode shapes. The approach has been proved through numerical simulations and a first experimental trial.

Non-linear behavior is present in many mechanical system operating conditions. In order to improve the controller performance, non-linear control techniques represent an attractive solution. In this paper the model-based sliding-mode-control (SMC) technique is considered because of its easy implementation and the strong robustness of the controller. Among the non-model-based control techniques, fuzzy (FC) and fuzzy model-reference-learning-control (FMRLC) based on if-then rules have been considered. Moreover, an energy-based (EB) law defining the control action without a system model is taken into account. These techniques have been tested on a three link flexible manipulator and a comparison between the results is presented.

A case study is conducted to investigate the potential of additional damping provided by a third viscous damper for the case in which two rubber bushings are already attached to the cables near the anchorages. The dependency between the damper location and optimum viscosity for maximum vibration mitigation that can be given to a cable with rubber bushings is investigated. The study shows that although rubber bushings may help mitigating vibrations, they reduce the effect of additional damping devices. However, if the third damper viscosity is selected properly, it can be very effective in further mitigating the vibration amplitudes.

A linear smart actuator system using SMA wires is proposed. A rectilinear (linear) actuator creates motion in a straight line. At its simplest, the linear actuator is a piston-like mechanism. The proposed linear smart actuator design consists of a fixed structural member and a sliding structural member which are engaged with each other along the longitudinal axis by four parallel SMA wires and an axially mounted helical passive spring, to provide linear stroke between the extended state and the contracted state. A geometrical analysis is carried out to investigate the position of the shaft due to the linear movement of the sliding structural member. Also the maximum force created by the linear smart actuator is computed mathematically using the stroke developed. When subjected to electric current, the SMA wires provide an actuating force and its cyclic contraction and expansion during heating and cooling produce a linear movement of the sliding unit. Analytical relations are derived for the force generated and displacement responses of the actuator. An open loop experimentation setup is designed to determine the fundamental characteristics of the linear smart actuator.