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This work presents the synergistic effect of BaTiO3 and graphene (Gr) reinforcement in polyvinyl diene fluoride (PVDF) matrix by chemical-assisted mechanical blending (CAMB) for possible 4D applications. The PVDF matrix was prepared (in form of filament) by solvent casting followed by twin-screw extrusion (TSE) as CAMB process. The filament was used on fused deposition modelling (FDM) setup for preparing standard flexural and pull-out specimens. The mechanical testing revealed that the parts printed with 100% in-fill density (ID), 70 mm/s infill speed (IS), and 45° in-fill angle (IA) has shown better flexural strength (FS). For pull-out properties, part printed at IS 90 mm/s, 0° IA, and 100% ID have shown better results. Further optimized settings of FS were used to 3D print thin cylindrical discs followed by electric poling (for possible piezoelectric properties). The results of X-ray diffraction (XRD) and Fourier transmission infrared spectroscopy (FTIR) analysis show more β-phase formation in the electrically poled sample as compared to non-poled specimen. Moreover, XRD spectra show the homogenous dispersion of doped material in the PVDF matrix. The piezoelectric coefficient (d33) 30.2pC/N was observed on 3D printed specimen (prepared from filament processed with CAMB), suitable for 4D applications.

By using the characteristics of two disparate materials (BaTiO3 ceramic and PZT-5H ceramic) on SiO2 glass, we have analyzed shear horizontal wave (SH wave) propagation through a piezo-visco-elastic...

The development of modern technology now are much more advanced and it can make doing a job much easier such as security problems for door locks that are applied to the electrical lecturer room UMSIDA. This tool is designed to run a solenoid lock by using a knock code applied to the door locking system by using microcontroller and piezo electric sensor which will be seen with a security system with knock method. The purpose of this study was to determine the constraints of the door safety device using an electric piezo sensor based on the Atmega328 microcontroller and the system can correctly recognize the beat pattern received and process it. This tool system works when there is an input in the form of a password code through the beats detected by electric piezo if the password code is applied correctly then the microcontroller provides input on relay to activate the solenoid and stepper motor, so the door would open. The result of this research shows that it can identify the correct number of beats a maximum of 15 beats, if it is more than 15 times the beat is wrong. From the result of the trial, fast or not a knock is declared true if the beat time ratio is slow by 4 times knock and the door opens. If the knock pattern is different from what has been determined, then the knock is declared wrong and the door can not open. The test results indicated that it can be concluded that from the test or trial carried out by the object provides true overall results even though the results do not provide 100% results. The results of the analysis of the trial carried out by each objects for 15 times, which affects fast or slow beats, number of beats, the ratio of time between knock

The present paper presents an innovative approach for the numerical modeling of piezo-electric transducers for the health-monitoring of layered structures. The numerical approach has been developed in the frameworks of the Carrera Unified Formulation. This computational tool allows refined numerical models to be derived in a unified and efficient fashion. The use of higher-order models and the capability to connect different kinematic models using the node-dependent kinematic approach has led to an efficient modeling technique for global-local analysis. This approach can refine the model only in those regions where it is required, e.g., the areas where piezo-electric transducers are placed. The model has been used to study embedded and surface-mounted sensors. The accuracy of the present model has been verified by comparing the current results with numerical and experimental data from the literature. Different modeling solutions have been developed, mixing one-, two- and three-dimensional finite elements. The results show that the use of the present modeling technique allows the computational cost to be reduced with respect to the classical approaches preserving the accuracy of the results in the critical areas.

Nowadays, much effort is directed towards solving the energy crisis resulting from depletion of fossil fuel. This has resulted in new approaches in energy industry like developing new sources of energy and harvesting already wasted energy. One of the commonly wasted forms of energy is the vibrational energy existing in noise produced from daily life activities. The goal of this work is to put a design for an Acoustic Energy Harvesting unit that is based on a Piezo-Electric transducer that can convert sound energy of noise into electric energy. The design process followed an experimental approach. It included open circuit as well as closed circuit experiments. The open circuit experiment aimed at finding a good initial guess for incident sound frequency for optimum energy harvesting while the closed circuit experiment aimed at finding the suitable circuit electrical impedance that would maximise energy harvesting at the frequency obtained from the initial guess. The proposed design can harvest power of 0.043 μW, with voltage of 21 mV and current of 2.05 μA, at power harvesting density of 2.8x . These results are achieved at incident sound of sound pressure level (SPL) of 118 dB and frequency of 466.2 Hz.

This project was developed to need for a system that generates non conventional energy. Energy crisis is one of the major issues worldwide. This paper proposes maximum utilization of human locomotion energy for power generation using Piezo electric sensors. The basic principle was, any vibration or pressure that generate between surface and footsteps while walking, is converted into electric energy using Piezo electric transducers. A series connection of Piezo electric transducers are mounted on the tile and this tile is placed in the crowded area for the generation of electric energy. This paper explores the power generated by footsteps and used for mobile charging.

Results are presented from studying industrially produced ferro-piezoelectric ceramic material PСR-80 based on the PbTiO3–PbZrO3–PbNb2/3Mn1/3O3–PbNb2/3Zn1/3O3 + SiO2 system. Patterns of changes in its reverse nonlinearity, inverse piezoelectric effect, and the electromechanical and dielectric hysteresis of the amplitude of a constant electric field are established.

A completely energy autarkic design for a classroom response system is presented. Maloperation by the user is prevented with the chosen design (no unnecessary buttons and switches). Electronic classroom response systems have been around for quite a while and do exist in various forms and flavors. Most commercially available solutions, however, have several disadvantages. The new device is an easy-to-use, robust form of a clicker, which takes its energy from the click itself, due to a very low-power system using only an energy of around 15 μ J per wireless telegram transmitted from each student to the teacher’s computer. The described system serves as both, a method to check students’ progress in any field of lecturing as well as a tool that (by its development) instructs students in the field of “Energy Harvesting for Small Wireless Devices”. The system also contributes to raising awareness of the material and energy balance in today’s electronics.

Due to repeated heavy loads, environmental conditions and non-frequent monitoring, the rail is subjected to heavy damage resulting in sudden failure. Hence, a frequent, faster, and efficient monitoring strategy is required. This paper attempts to investigate the application of guided wave (GW) generated through surface-bonded piezo-electric wafer transducer (PWT) to detect damages in rail at high frequencies. Firstly, a combined experimental and simulation study is presented in an effort to understand the dispersion characteristics of guided wave and its interaction with head damages in a relatively small rail specimen. The numerical simulation results are validated with those obtained from the experiments showing a good agreement between them. Secondly, a framework based on the machine learning algorithm is proposed to efficiently detect damage in rail head. Numerous inseparable guided wave modes are observed at higher frequencies implying the inability to detect damage through specific mode. Therefore, a machine learning framework is trained using time, frequency, and time–frequency domain features of the signal. Total 672 numerical simulations of different types of damage with different severity and location in the rail head are carried out to train and validate the model. It is found that GW generated through surface bonded PWTs is able to detect minimum defect size of 5% of head area with 1 mm thickness. Finally, the proposed framework is tested using simulation and experiment results of arbitrary damage in the rail head. The error in estimating severity was found to be in the range from 2.00% to 16.67%.

A new concept is needed in designing and processing of nanostructured ceramic-polymer composites to respond to all technological requirements related to 3D-printing technology for obtaining innovative flexible piezo-electric harvesters. A technique for obtaining of thermoplastic composites with piezoelectric features is presented.

We present an approach for preparing cryoEM grids to study short-lived molecular states. Using piezo electric dispensing, two independent streams of ~50 pL sample drops are deposited within 10 ms of each other onto a nanowire EM grid surface, and the mixing reaction stops when the grid is vitrified in liquid ethane, on the order of ~100 ms later. We demonstrate the utility of this approach for four biological systems where short-lived states are of high interest.

Electrohydraulic servovalves are widely used for precise motion control in aerospace and other industries due to their high accuracy and speed of response. However, commercial two-stage servovalves have several undesirable characteristics, such as the power consumption caused by the quiescent flow (internal leakage) in the pilot stage, and the complexity and high number of parts of the torque motor assembly, which affect the cost and the speed of manufacture. The solution to these problems can help to reduce costs, weight and power consumption, and enhance the reliability and reproducibility as well as the performance of these valves. For these reasons, this paper proposes a novel configuration for the pilot stage: it is composed of two normally closed two-way two-position (2/2) valves actuated by two piezo-electric ring benders, the opening and closing of the two piezo-valves can generate a differential pressure to be used to control the displacement of the main spool. In this way, there is negligible quiescent flow when the main stage is at rest, in addition, the torque motor and all its components are removed. To assess the performance of this novel pilot stage concept, a prototype of the piezo-valve has been constructed and tested. The experimental results indicate that the response speed of the new piezo-valve is very high. Furthermore, a numerical model is employed to show that, by adjusting specific parameters, the performance of the piezo-valve can be further improved, so that the valve can be fully opened or closed in less than 5 ms.

In part I of this study, we experimentally and numerically investigated the pilot stage of a novel two-stage servovalve architecture. The novelty of the proposed configuration is the torque motor being removed and replaced with two small two-way two-position (2/2) valves actuated by piezoelectric ring benders, which can effectively control the opening degree of a main spool valve. With this novel architecture, the typical drawbacks of two-stage servovalves can be overcome, such as the high complexity of the torque motor and the high internal leakage in the pilot stage when the main valve is at rest in the neutral position (null). The low complexity and the negligible internal leakage of the piezo-valves are accompanied by the high response speed typical of piezoelectric actuators. The valve assessment is completed in the present study, since the entire valve architecture (main stage + pilot stage) is investigated. In particular, a simplified numerical model is developed to provide a design tool that allows, for a given main stage spool, the values of the geometrical parameters of the pilot stage to be chosen along with the characteristics of the ring bender. This design procedure is applied to a 7 mm diameter main spool; afterward, a detailed numerical model of the entire valve, solved by SimScape Fluids software, is employed to demonstrate that the response of the main stage valve is very rapid while ensuring negligible internal leakage through the piezo-valves when the main stage is closed (resulting in lower power consumption). For this reason, the proposed valve can be regarded as a “clean” component for energy conversion, having lower energy consumption than commercially available servovalves.

This paper reports the development of a family of devices that are all based on fundamental blocks compose of: piezo electric beams, magnets, and mechanical stoppers that act as electric contacts. We have implemented combination of the proposed building blocks in order to realize devices for harvesting kinetic energy from weak and wide spectrum sources. It is worth noting that a proper use of these blocks has been also exploited to demonstrate the realization of devices which can be used as voltage rectifiers and multiplication circuits.

Although resource-efficient processes like inkjet printing have a large potential to foster the development of smart and functional textiles, one bottleneck still is the development of functional inks. To make inkjet printing and UV curing given production techniques for smart and functional specialty products, e.g. photochromic textiles, deepened knowledge about the development, rheological behavior and jetting behavior of functional ink is needed. This paper focuses on the formulation and performance of UV-responsive and UV-curable inkjet inks, which are based on photochromic dyes and their application to produce UV-responsive textiles. Two commercial photochromic dyes—Reversacol Ruby Red (RR) and Sea Green (SG), which represent dyes of the naphthopyran and spirooxazine class, respectively, have been used to develop the inks. The photochromic inks are characterized according to their physical–chemical and rheological properties in respect to temperature. The influence of temperature on the drop formation of the inks in an industrial print head is analyzed using a high-speed camera, which reveals important information regarding challenges in ink jettability. It was found that the dye structure and type used in the ink can influence the jetting behavior of photochromic UV-curable ink. More pronounced temperature sensitivity of dyes can increase the temperature-related effects of drop formation as was observed for SG ink. The printability of the RR and SG inks is framed and underpinned by theoretical calculations of the Z number. Discrepancies are observed and discussed between existing theory of ink jettability and visual evaluation of the photochromic ink.

The Micro Aerial Vehicle (MAV) with a flapping wing configuration is much more efficient and capable of generating substantial lift at low flight speeds and has excellent maneuverability. Different motor-driven mechanisms have been developed to mimic this flapping motion, but these mechanisms introduced mechanical complexity and heavy weight to the system. Piezo-electric based mechanisms have been used to solve these problems, but provide very small flapping amplitudes within the size limitation of MAVs. So some kind of amplification mechanism is needed. In this paper, a flexible wing is created by attaching a polymer skin to a pair of carbon fiber reinforced plastic spars. This wing is connected by means of an elastic-element (EE) to a pair of piezoelectric unimorphs (piezofan). The motion from the piezofan to the wing is transferred through this EE. Simulation has been done by applying sinusoidal voltages of varying frequency to this piezofan and observations have been made for the flapping amplitude of the wing for different stiffness of the EE. It is observed that the amplitude of the peak flapping amplitude initially increases, attains a maximum value, then decreases again with an increase in the stiffness of the EE. It is also observed that as the EE stiffness increases, the corresponding peak of the flapping amplitude shifts towards higher frequency.

This paper presents a comparative study of activity sensors: piezoelectric and accelerometer sensor, for the design of rate adaptive pacemaker. Activity sensors are incorporated with the demand mode pacemaker for achieving rate adaptiveness of the pacing. There is a conflict in selecting the activity sensors: accelerometer and piezoelectric. These sensors could monitor the physical activity of the patients and adapt the pacing rate to the needs of the activity of the patient. Implanting these physiological sensors into pacemakers made it possible for the physicians to individually optimize pacing parameters for each patient. Piezoelectric sensors may not response accurately for some kind of activities like cycling, walking down stairs etc. Accelerometer sensors have also the limitations for measuring prolonged duration activities. Clinically, accelerometer based activity sensors have dominated the piezoelectric based activity sensor for the design of rate adaptive pacemaker. Therefore, in this paper we have performed the frequency and time domain analysis for analyzing the technically suitable activity sensor for the design of rate adaptive pacemaker and it is found that accelerometer performs 90% faster than piezoelectric sensor.

Rapid detection and characterization of pathogens in patients with bloodstream infections (BSIs) is a persistent problem for modern medicine, as current techniques are slow or provide incomplete diagnostic information. Real-time polymerase chain reaction (qPCR) allows specific detection of a wide range of targets and quantification of pathogenic burdens to aid in treatment planning. However, new technological advances are required for a rapid and multiplex implementation of qPCR in clinical applications. In this paper, the feasibility of a novel microfluidic platform for qPCR is presented, integrating highly sensitive, label-free localized surface plasmon resonance (LSPR) imaging of DNA hybridization into a recirculating chip design for real-time analysis. Single target and multiplex detection of DNA target amplification are demonstrated, with a limit of detection of 5 fg μL−1 of E. coli DNA for single target PCR, correlating with approximately 300 bacteria per mL. The results of this study demonstrate the potential of this platform for simultaneous real-time detection of multiple target genes within 15 minutes that could provide live saving benefits in patients with BSIs.

Piezoelectric surgery was first explained by French Jacques and Pierre Curie in 1880. Piezoelectric bone surgery is a novel osteotomy and osteoplasty technique invented by Professor Vercellotti in 1988 to overcome the limitations of traditional instrumentation in oral bone surgery by modifying and improving conventional ultrasound technology. The cutting action is the result of linear microvibrations, in amplitude between 30 and 200 μm that allow to obtain a micrometer precision in the range of 25-29 KHz modulated ultrasonic resonant frequency. Nerves, vessels, and soft tissue are preserved by the microvibrations (60 to 200 mm/sec), which are optimally adjusted to target only mineralized tissue. It is a minimally invasive osteotomy device to achieve unparallel precision, patient comfort, intra-operative sensitivity, intra-operative visibility, blood free surgical site and reduced damage to the surrounding soft tissues, osteocytes and important structures like nerves, muscles and mucosa. Also Piezosurgery is very useful in harvesting autogenous bone for regenerating periodontal defects. Various treatment modalities are based on removal of etiologic factors and preserving bone architecture. Recently this novel surgical approach has gained popularity in various fields of dental implantology, oral and maxillofacial surgery, endodontics, and orthopedics. This article aims to review the clinical calibre of piezosurgery in the field of periodontology and implant dentistry. Key Words : LESS INVASIVE, PRECISION CUTTING, MICRO VIBRATIONS, FASTER RECOVERY, PIEZO TECHNIQUE

A physical elastic experimentation domain is immersed within a numerically modeled environment by actively cancelling the boundary reflections at the free surface of a solid target and replacing them with interactions from a desired exterior environment. The paper presents a theoretical derivation for elastic immersive experimentation, as well as the first experimental demonstration in a beam using a state-of-the-art laser doppler vibrometer and three-component piezo electric actuators.

The last few decades have seen the advancement in information technology as no other period in history. The same period has also seen dramatic increase in computational power and a correspondingly significant decrease in the cost of electronics. In addition, internet and wireless telecommunication have exploded in the first decade of the twenty-first century. Advancements in these areas have resulted in several synergies to deliver innovation in diverse applications leading to an era of digital transformation. The mining industry has been relatively slow in adopting these technologies compared to many other industries such as aviation, finance or even oil and gas.

Pollution is a major problem all over the world. According to the energy conservation statement law states that energy cannot be created or destroyed but can be converted from one form to another. As it relates to nature, the sudden increase in urban and industrial growth has been completed with potentially hazardous waste. Sound is the electrical energy of the machine and can be converted into electrical energy through many provocative methods including heating using piezoelectric material and diaphragm. Other sounds are not preventable such as road noise, market noise, industry, train stations etc. and those unnecessary noises can be used to generate electricity. In this way we can reduce the use of piezoelectric power and energy generated by chemical materials where it is converted directly from energy to electrical energy. The widespread use of this space is to focus on how we can increase the electrical performance generated by the conversion of sound energy from non-renewable sources. When sound vibrations are in the diaphragm and are compressed and hard to convert into electrical energy.

A hypersingular approach of the boundary element formulation -BEM- is presented for the analysis of the temperature in fracture problems of multifield materials. A fundamental solution based on the extended Stroh formalism is considered. Hypersingular integrals arising in the traction boundary and heat flux integral equations are computed through a regularization technique causing that only regular integrals are computed numerically. The generality of the method allows the study of 2D solids with no shape restrictions. Generalized intensity factors -IFs- are accurately computed from nodal values next to crack tip. Finally, the possibilities of the presented approach are discussed in order to apply it for the assessment of the influence of temperature in fracture problems for materialspresenting mechanical, magnetic and/or electrical coupling

Acoustic-structural properties of piezo-electric driven resonant cavities usually employed to generate the so-called synthetic jets are theoretically and numerically investigated in order to characterize the performances of such devices. It is shown that the actuator behaves as a two-coupled oscillators system and the dimensionless form of the governing equations allows one to identify various operating conditions, in particular those leading to their decoupling. The theoretical predictions are validated through analytical, numerical and experimental findings for devices having different mechanical and geometrical characteristics, designed to achieve an increasing coupling effect. Considerations about the strength of jet formation at the Helmholtz frequency are made as well.

In this paper, a study of effective parameters and wave properties of a slab of an artificial material comprised of alternating piezomagnetic and piezoelectric layers is presented. This kind of composite structure features new functionalities including effective magneto-electric coupling nonexistent in either constituent layer. In the first section, the equations of propagation of hybrid elasto-electro-magnetic waves in the equivalent homogeneous medium are derived by using a double scale method based on the periodical homogeneization. The wave length is considered to be much greater than the layer spatial periodicity and electromagnetic retardation is not taken into account. In the second section, dispersion relations for the hybrid waves travelling in a slab with previously established effective parameters are obtained. It was shown that although all three components, mechanic, electric and magnetic, contribute to the overall oscillatory behavior, the wave is predominantly elastic. At the same time, such composite media demonstrate double tunability, electric via the piezoelectric phase and magnetic through the piezomagnetic one, and can be regarded as novel functional materials.

After annealing the solution cast P(VDF-TrFE) films at elevated temperatures, which were synthesized via a full hydrogenation process from P(VDF-CTFE) with a composition of VDF/TrFE = 80/20 (mol%), a series of P(VDF-TrFE) films were fabricated in present work. The crystalline and ferroelectric phases of the films were carefully characterized and their dielectric, ferroelectric and piezoelectric properties were systematically investigated. The improved crystalline and ferroelectric phases in the films induced by annealing at elevated temperatures are responsible for the significant improved electric properties of the films. The optimized annealing temperature is found to be 130 °C and the best performance including the highest dielectric constant of 12.5 at 1 kHz, the largest maximum polarization of 11.21 μC/cm2 and remnant polarization of 7.22 μC/cm2, the lowest coercive electric field of 56 MV/m, and the highest piezoelectric coefficient of -25 pC/N is observed.

Finite element simulation of a piezo-electric generator (PEG) of a cantilever type with an active termination is considered. Finite element modeling was performed in the Ansys complex. The generator has a bimorphic arrangement of piezoelectric elements. A special feature of PEG is that the generator has two types of piezoelements: (1) elements located on the substrate in the form of a bimorph and (2) cylindrical piezoelements, which fix the cantilever plate. PEG can be used as a device for generating energy. A generator design oscillations modal analysis - was performed. For a given scheme of electrical connection of the PEG elements and various resistive loads, the results of the output voltage and power are given.