Showing papers on "Piezoelectric sensor published in 2016"
TL;DR: Self-standing films of native cellulose nanofibrils (CNFs) were synthesized and characterized to suggest that CNF is a suitable precursor material for disposable piezoelectric sensors, actuators, or energy generators with potential applications in the fields of electronics, sensors, and biomedical diagnostics.
Abstract: Self-standing films (45 μm thick) of native cellulose nanofibrils (CNFs) were synthesized and characterized for their piezoelectric response. The surface and the microstructure of the films were evaluated with image-based analysis and scanning electron microscopy (SEM). The measured dielectric properties of the films at 1 kHz and 9.97 GHz indicated a relative permittivity of 3.47 and 3.38 and loss tangent tan δ of 0.011 and 0.071, respectively. The films were used as functional sensing layers in piezoelectric sensors with corresponding sensitivities of 4.7–6.4 pC/N in ambient conditions. This piezoelectric response is expected to increase remarkably upon film polarization resulting from the alignment of the cellulose crystalline regions in the film. The CNF sensor characteristics were compared with those of polyvinylidene fluoride (PVDF) as reference piezoelectric polymer. Overall, the results suggest that CNF is a suitable precursor material for disposable piezoelectric sensors, actuators, or energy gene...
192 citations
TL;DR: These skin-attachable film- or sheet-type mechanical sensors with high flexibility are expected to enable various applications in the field of wearable devices, medical monitoring systems, and electronic skin.
Abstract: Here, we developed highly sensitive piezoelectric sensors in which flexible membrane components were harmoniously integrated. An electrospun nanofiber mat of poly(vinylidenefluoride-co-trifluoroethylene) was sandwiched between two elastomer sheets with sputtered electrodes as an active layer for piezoelectricity. The developed sensory system was ultrasensitive in response to various microscale mechanical stimuli and able to perceive the corresponding deformation at a resolution of 1 μm. Owing to the highly flexible and resilient properties of the components, the durability of the device was sufficiently stable so that the measuring performance could still be effective under harsh conditions of repetitive stretching and folding. When employing spin-coated thin elastomer films, the thickness of the entire sandwich architecture could be less than 100 μm, thereby achieving sufficient compliance of mechanical deformation to accommodate artery–skin motion of the heart pulse. These skin-attachable film- or sheet...
159 citations
TL;DR: In this article, a prototype consisting of piezoelectric disks sandwiched between two copper plates was assembled in between asphalt mixtures and a uniaxial compression test was performed to measure the output power under different numbers and arrangements of the disks, and the sensitivity of the power to loading frequency, vertical load, test temperature, and loading time was also studied.
149 citations
TL;DR: The results reveal that self-polarization due to grain orientation along the spontaneous polarization direction plays an important role in achieving large piezoelectric response in a domain motion-confined material.
Abstract: A rapid surge in the research on piezoelectric sensors is occurring with the arrival of the Internet of Things. Single-phase oxide piezoelectric materials with giant piezoelectric voltage coefficient (g, induced voltage under applied stress) and high Curie temperature (Tc) are crucial towards providing desired performance for sensing, especially under harsh environmental conditions. Here, we report a grain-oriented (with 95% texture) modified PbTiO3 ceramic that has a high Tc (364 °C) and an extremely large g33 (115 × 10-3 Vm N-1) in comparison with other known single-phase oxide materials. Our results reveal that self-polarization due to grain orientation along the spontaneous polarization direction plays an important role in achieving large piezoelectric response in a domain motion-confined material. The phase field simulations confirm that the large piezoelectric voltage coefficient g33 originates from maximized piezoelectric strain coefficient d33 and minimized dielectric permittivity ɛ33 in [001]-textured PbTiO3 ceramics where domain wall motions are absent.
131 citations
TL;DR: In this paper, an intelligent neural network based controller is designed to control the optimal voltage applied on the piezoelectric patches of a flexible cantilever plate to mitigate the vibration response.
110 citations
TL;DR: A brief overview of flexible and stretchable piezoelectric nanocomposite generator for realizing the self-powered energy system with development history, power performance, and applications is provided.
Abstract: Piezoelectric energy conversion that generate electric energy from ambient mechanical and vibrational movements is promising energy harvesting technology because it can use more accessible energy resources than other renewable natural energy. In particular, flexible and stretchable piezoelectric energy harvesters which can harvest the tiny biomechanical motions inside human body into electricity properly facilitate not only the self-powered energy system for flexible and wearable electronics but also sensitive piezoelectric sensors for motion detectors and in vivo diagnosis kits. Since the piezoelectric ZnO nanowires (NWs)-based energy harvesters (nanogenerators) were proposed in 2006, many researchers have attempted the nanogenerator by using the various fabrication process such as nanowire growth, electrospinning, and transfer techniques with piezoelectric materials including polyvinylidene fluoride (PVDF) polymer and perovskite ceramics. In 2012, the composite-based nanogenerators were developed using simple, low-cost, and scalable methods to overcome the significant issues with previously-reported energy harvester, such as insufficient output performance and size limitation. This review paper provides a brief overview of flexible and stretchable piezoelectric nanocomposite generator for realizing the self-powered energy system with development history, power performance, and applications.
91 citations
TL;DR: In this paper, a highly sensitive tactile sensor based on a floating gate organic transistor called Organic Charge Modulated FET coupled with a flexible piezoelectric polymer (namely a film of polyvinylene fluoride, PVDF) was proposed.
74 citations
TL;DR: In this article, the authors used Reddy's higher-order shear deformation theory (HSDT) with the element-free IMLS-Ritz method to investigate the active vibration control of functionally graded material (FGM) plates with piezoelectric layers.
71 citations
TL;DR: In this paper, the use of polyvinylidene fluoride (PVDF) films as sensors for vibration measurement in the areas of portable medical detections, structural health monitoring, mechanical equipment vibration measurements and other applications.
Abstract: Information about vibrating objects can be obtained by vibration measurements. Piezoelectric sensors made by piezoelectric ceramics, quartz, or organic piezoelectric materials, e. g. polyvinylidene fluoride (PVDF) have been adopted by many researchers to measure vibrations. Among these piezoelectric materials, PVDF has attracted much attention for its excellent properties such as outstanding chemical resistance, high thermal stability, low permitivities, low acoustic impedances, flexibility and membrane forming properties. In this paper, PVDF is introduced in brief. In addition, this paper briefly reviews the use of PVDF films as sensors for vibration measurement in the areas of portable medical detections, structural health monitoring, mechanical equipment vibration measurements and other applications. Meanwhile, some cases which have good low-frequency performances or novel features in structures will be especially introduced to provide helpful experiences for future applications. In the end, a ...
65 citations
TL;DR: In this article, a series of composite specimens with and without embedded sensor are tested in fatigue loading while constantly monitoring the response by acoustic emission technique, and the acoustic signals are analyzed using the classification k-means method in order to identify the different damage mechanisms and to follow the evolution of these mechanisms for both types of composite materials (with and without sensor).
62 citations
TL;DR: In this article, the application of an innovative real-time structural health monitoring system is studied through tests performed on flexural and shear-critical reinforced concrete elements subjected to monotonic and cyclic loading.
TL;DR: In this article, a finite element model for the dynamic analysis of sandwich laminated plates with a soft core and composite laminated face layers, as well as piezoelectric sensor and actuator layers is presented.
TL;DR: In this article, the dynamic response and the active vibration control behavior of various functionally graded carbon nanotube reinforced composite (FGCNTRC) rectangular plates are investigated numerically instrumented with piezoelectric sensor and actuator layers.
TL;DR: In this paper, a mathematical model of the stabilizer for mobile objects is presented, an equation of motion is obtained, and the schematic of the major components of the automated weapons stabilizer system is determined.
TL;DR: In this article, an active vibration suppression of a simply supported, arbitrarily thick, transversely isotropic circular cylindrical host panel, integrated with spatially distributed piezoelectric actuator and sensor layers, is investigated based on the linear three dimensional exact piezoelasticity theory.
Abstract: Active vibration suppression of a simply supported, arbitrarily thick, transversely isotropic circular cylindrical host panel, integrated with spatially distributed piezoelectric actuator and sensor layers, is investigated based on the linear three dimensional exact piezo-elasticity theory. To assist control system design, system identification is conducted by applying a frequency domain subspace approximation method based on N4SID algorithm using the first few structural modes of the system. The state space model is constructed from system identification and used for state estimation and development of control algorithm. The optimal electrode configuration for the collocated piezoelectric actuator–sensor pair is found by applying a genetic optimization procedure based on maximization of a quantifiable objective function considering the controllability, observability and spillover prevention of the identified system. A linear quadratic Gaussian (LQG) optimal controller is subsequently designed and simulated based on the identified model of optimally configured smart structure in order to actively control the system response in both frequency and time domains. The dynamic performance and effectiveness of the optimized vibration control system is demonstrated for two different types of external mechanical excitations (i.e., impulsive load and white noise disturbance). The accuracy of dynamic analysis is established with the aid of a commercial finite element package and the data available in the literature.
TL;DR: This work made simulations of the effect of the three types of losses in piezoelectric materials on the impedance spectrum at the resonance, and introduces a simplified equivalent circuit model with electrical parameters that account for piezoceramic losses needed for the modeling and design of industrial applications.
Abstract: Electronic devices using the piezoelectric effect contain piezoelectric materials: often crystals, but in many cases poled ferroelectric ceramics (piezoceramics), polymers or composites. On the one hand, these materials exhibit non-negligible losses, not only dielectric, but also mechanical and piezoelectric. In this work, we made simulations of the effect of the three types of losses in piezoelectric materials on the impedance spectrum at the resonance. We analyze independently each type of loss and show the differences among them. On the other hand, electrical and electronic engineers include piezoelectric sensors in electrical circuits to build devices and need electrical models of the sensor element. Frequently, material scientists and engineers use different languages, and the characteristic material coefficients do not have a straightforward translation to those specific electrical circuit components. To connect both fields of study, we propose the use of accurate methods of characterization from impedance measurements at electromechanical resonance that lead to determination of all types of losses, as an alternative to current standards. We introduce a simplified equivalent circuit model with electrical parameters that account for piezoceramic losses needed for the modeling and design of industrial applications.
TL;DR: In this paper, an impact-type piezoelectric sensor was developed for real-time monitoring of grain sieve losses in combine harvesters, and the influence of grain shape, straw length and impact angle on variations of the maximum normal contact force and force rise-time were analyzed in detail.
TL;DR: In this paper, the performance of the surface response to excitation (SuRE) method was evaluated with the conventional piezoelectric elements and scanning laser vibrometer used as contact and non-contact sensors, respectively, for monitoring the presence of loads on the surface.
TL;DR: The vibration suppression of smart structures using intelligent control strategy is considered and the results obtained are very satisfactory compared to previous investigations of the team.
TL;DR: In this article, the use of piezoelectric disk buzzers, usual in stringed musical instruments to acquire sound as a voltage signal, for experimental modal analysis is presented.
Abstract: We present the use of piezoelectric disk buzzers, usual in stringed musical instruments to acquire sound as a voltage signal, for experimental modal analysis. These transducers helped in extracting natural frequencies and mode shapes of an aluminium beam and a steel arch in the laboratory. The results are compared with theoretical predictions and experimental values obtained by accelerometers and a laser displacement transducer. High accuracy, small dimensions, low weight, easy usage, and low cost, make piezoelectric pickups an attractive tool for the experimental modal analysis of engineering structures.
TL;DR: Based on theory of piezo-elasticity, bending behavior of functionally graded carbon nanotube reinforced composite (FG-CNTRC) cylindrical panel attached to thin piezoelectric layers subjected to thermal, mechanical loads and or electric field is investigated in this article.
Abstract: Based on theory of piezo-elasticity, bending behavior of functionally graded carbon nanotube reinforced composite (FG-CNTRC) cylindrical panel attached to thin piezoelectric layers subjected to thermal, mechanical loads and or electric field is investigated. It is assumed that thermo-elastic constants of the structure are independent of temperature gradient. In this paper, uniformly and various cases of functionally graded CNT distribution along the radial direction of host layer are considered. Governing differential equations are solved analytically by using the Fourier series expansion along axial and circumferential direction and state-space technique across the radial direction. Temperature, stress and displacement fields as well as induced electric voltage in sensor layer are obtained and used to study the thermo-piezoelastic behavior of hybrid FG-CNTRC cylindrical panel. Accuracy of present approach is validated by comparing the numerical results with the available reported results in literatures. Parametric studies are carried out to assess the effects of CNT volume fraction, case of CNT distribution along the radial direction, surface thermal/mechanical surface boundary conditions, applied voltage on the bending behavior of FG-CNTRC hybrid cylindrical panel.
TL;DR: In this article, an effective strategy to improve the piezoelectric behavior of sputtered ZnO thin films is proposed by introducing a nanobranched porous thin film structure composed by a network of randomly-oriented wurtzite crystallites.
Abstract: ZnO nanomaterials are gaining lots of attention due to their biocompatible nature coupled with promising piezoelectric properties, envisioning a new generation of lead-free smart materials. Herein, an effective strategy to improve the piezoelectric behaviour of sputtered ZnO thin films is proposed by introducing a nanobranched porous thin film structure composed by a network of randomly-oriented wurtzite crystallites, rather than using compact ZnO thin films, considered in this work as a conventional reference for sputtered ZnO thin film structures. The nanobranched ZnO structure shows a hydrophilic behavior together with a piezoelectric output voltage of around 3 V. In comparison, compact ZnO thin films exhibit a maximum piezoelectric voltage generation below 0.8 V and a hydrophobic state. The more defective structure of the nanobranched ZnO thin films, with respect of the long-range ordered crystal structure of compact ZnO thin films, reduces free carrier concentration and mobility, thus limiting the screening potential and at the same time improving piezoelectric voltage generation. All the characterization results highlight the promising perspectives in using nanobranched ZnO thin films as novel piezoelectric materials for biosensing and tissue engineering applications, as well as for lead-free piezoelectric sensors and energy harvesting systems.
TL;DR: In this article, the structural design of a piezoelectric module is optimized to increase an electrical energy generation using a Taguchi factorial effect analysis method, and the maximum terminal voltage was defined as a characteristic value to evaluate the optimal design parameters.
Abstract: Piezoelectric systems are commonly utilized to transform mechanical vibrations to electrical energy that can be used to diverse power devices. In this work, it has been studied to improve the efficiency of a piezoelectric system with modification of the shape of a piezoelectric module and its vibration mode using analysis and experimental approaches. The basic shape of piezoelectric plate used in this work is width of 10 mm, length of 30 mm, and thickness of 0.2 mm. The structural design of a piezoelectric module is optimized to increase an electrical energy generation using a Taguchi factorial effect analysis method. The maximum terminal voltage was defined as a characteristic value to evaluate the optimal design parameters. Through this work, we have selected an optimal one among three designed different types of piezoelectric modules. And the optimal module shows that the output power was approximately 10 to 30% higher than other modules.
TL;DR: In this article, a load monitoring index was used to correlate the dominating peak frequency of the real part of the electrical impedance signature to the pin connection load, which can successfully be used to monitor the loading status of pin connections in practical applications.
Abstract: This paper presents a feasibility study on a developed impedance-based technique using Lead Zirconate Titanate patches for load monitoring of pin-connected structures, which are widely used in construction industry. The basic principle behind the load-monitoring technique is to utilize a high-frequency excitation signal (typically >30 kHz) through a surface-bonded piezoelectric sensor/actuator to detect changes in mechanical impedance of the structure due to the variations in structural loads. In order to verify the effectiveness of the developed technique, a tension-controllable structure with a pin connection was fabricated and investigated in this study. A load monitoring index was used to correlate the dominating peak frequency of the real part of the electrical impedance signature to the pin connection load. Experimental results obtained from twenty repeated tests prove that the proposed load-monitoring index increases as the load on the pin connection increases due to the enlarging true contact area of the pin connection. A 3D finite element method was also used to simulate and analyze the impedance signature of a pin connection model. Very good agreement exists between the numerical simulation's results and the experimental results which demonstrates that the impedance-based technique can successfully be used to monitor the loading status of pin connections in practical applications.
TL;DR: In this paper, a scanning spatial-wavenumber filter and piezoelectric sensor (referred to as PZT) 2-D cruciform array based on online damage imaging method of composite structure was proposed.
Abstract: The spatial-wavenumber filtering technique of Lamb wave is gradually applied for damage inspection of composite structure in recent years because it is an effective approach to distinguish the wave propagating direction and mode. But for on-line damage monitoring of composite structure by using spatial-wavenumber filter, the problem is how to realize the spatial-wavenumber filtering of Lamb wave when the wavenumber response cannot be measured or modeled. This paper proposes a scanning spatial-wavenumber filter and piezoelectric sensor (referred to as PZT) 2-D cruciform array based on-line damage imaging method of composite structure. In this method, a 2-D cruciform array constructed by two linear PZT arrays is placed on composite structure permanently to acquire Lamb wave damage scattering signal on-line. For one linear PZT array, a scanning spatial-wavenumber filter which does not rely on any modeled or measured wavenumber response is designed to filter the damage scattering signal at a designed wavenumber bandwidth to give out a wavenumber-time image. Based on the image, the wavenumber of the damage scattering signal projecting at the array can be obtained. The same process can be also applied to the other linear PZT array to get the wavenumber projecting at that array direction. By combining with the two projection wavenumbers, the damage can be localized without blind angle. The method is validated on an aircraft composite oil tank of variable thickness. The validation results show that the damage direction estimation error is less than 2° and the damage distance estimation error is around 20 mm in the monitoring area of nearly 600 mm × 300 mm. It indicates an acceptable performance of the damage imaging method for complex composite structure.
TL;DR: In this paper, an optimal delayed feedback control methodology is developed to mitigate the primary and super harmonic resonances of a flexible simply-simply supported beam with piezoelectric sensor and actuator.
Abstract: An optimal delayed feedback control methodology is developed to mitigate the primary and super harmonic resonances of a flexible simply-simply supported beam with piezoelectric sensor and actuator. Stable vibratory regions of the feedback gains are obtained by using the stability conditions of eigenvalue equation. Attenuation ratio is used to evaluate the performance of vibration control by taking the proportion of peak amplitude of primary or super harmonic resonances for the suspension system with and without controllers. Optimal control parameters are obtained using an optimal method, which takes attenuation ratio as the objective function and the stable vibratory regions of the time delay and feedback gains as constraint conditions. The piezoelectric optimal controllers are designed to control the dynamic behaviour of the nonlinear dynamic system. It is found that the optimal feedback gains obtained by the optimal method result in a good control performance.
TL;DR: In this paper, the use of finite element method (FEM) to simulate the electro-mechanical impedance technique is investigated, and the simulation results are then compared to experimental data and a very good agreement is observed.
Abstract: Electromechanical impedance (EMI) based monitoring techniques are successfully in use in current engineering structures. With the help of piezoelectric sensors, the EMI technique is used for monitoring the health of such structures. Generally, potential damage to the host structure is detected by examining the EMI signature and identifying changes in that unique signature. Since this technique has the potential to offer greater safety and reliability while lowering maintenance costs, it is becoming increasingly popular. This paper investigates the use of finite element method (FEM) to simulate the electro-mechanical impedance technique. A numerical analysis of simple models, such as free piezoelectric patches of various shapes and thicknesses is used to comprehend the fundamentals of this technique. Then, studies on different parts of the structure are conducted to find the effect on the output of system when both damage and loading co-exist, and investigate the effect of temperature for structural health monitoring based on EMI. The simulation results are then compared to experimental data and a very good agreement is observed.
TL;DR: In this paper, a closed-form digital image correlation (DIC) based solution was proposed to measure cutting forces at camera acquisition frequency, where the considered displacement fields were obtained from the Flamant-Boussinesq solution.
TL;DR: In this paper, the authors used the element free galerkin (EFG) method based on third-order shear deformation theory (TSDT) to investigate shape and vibration control of piezoelectric laminated plate bonded with piezer actuator and sensor layers.
Abstract: In this paper, the element free galerkin (EFG) method based on third-order shear deformation theory (TSDT) is used to investigate shape and vibration control of piezoelectric laminated plate bonded with piezoelectric actuator and sensor layers. The electric potential distributions through the thickness for each piezoelectric layer are assumed to vary linearly. In addition, a closed-loop velocity feedback control and optimal steady-state regulator with output feedback algorithm is used for the active control of the static deflection as well as the dynamic response of the plates with bonded distributed piezoelectric sensors and actuators. Furthermore, the effects of the size of support and nodal density on the numerical accuracy are also investigated. The results indicate that, the accuracy and reliability of presented work have an excellent agreement with those of other available numerical approaches such as finite element and FSDT meshfree method.
TL;DR: Novel vehicle classification technology is presented by utilizing a single-element piezoelectric sensor placed diagonally on a traffic lane to accurately identify vehicles to provide a highly accurate and cost-effective alternative to current vehicle classification systems.
Abstract: Summary
This paper presents novel vehicle classification technology by utilizing a single-element piezoelectric sensor placed diagonally on a traffic lane to accurately identify vehicles. Novelty of this technique originates from using diagonally placed piezoelectric strip sensor and machine learning technology to provide a highly accurate and cost-effective alternative to current vehicle classification systems. Diagonal placements of the piezoelectric strip sensor ensure detection of passing vehicle tires by facilitating vehicle classification process. Presented technology is capable of accurately classifying vehicles into a relatively large number of classifications, including motorcycle, which has proven to be a challenging category in present-day commercial vehicle classifiers. Vehicle classification is a vital intelligent transportation systems application. Accurate data reporting aids suitable roadway design for safety and capacity and can also support other purposes, such as reporting highway congestion to the general public or providing area denseness data to interested businesses.
To make a classification decision, a vehicle's signal is acquired from diagonal piezoelectric strip sensor, processed, and then applied to a machine learning algorithm. A speed estimation technique using the same single-element piezoelectric sensor was also developed, tested, and compared with an embedded vehicle classifier currently used by the Oklahoma Department of Transportation. Testing on several highway sites indicated up to 97% classification accuracy. This paper presents a complete description of the developed system, including sensor installation, data acquisition and processing, and classification algorithm. Overall, the system offers a high-performance cost-effective solution for vehicle classification that minimizes roadwork typically required for loop and sensor installations of current systems. Copyright © 2016 John Wiley & Sons, Ltd.