Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: piezoelectric material; dielectric constant; piezoelectric constant
Online: 17 September 2019 (15:17:17 CEST)
The effects of the dielectric constant of the powder phase on lead zirconate titanate (PZT)/PZT sol-gel composite films were investigated to tailor their electrical properties. Three types of PZT powders were used to fabricate three different PZT/PZT sol-gel composite films. The PZT powders had the same electromechanical coupling coefficient but different relative dielectric constants. The PZT/PZT films were fabricated on a 3 mm-thick titanium substrate using an automatic spray coating system, and their properties were investigated. The relative dielectric constants of the PZT/PZT films were successfully controlled by tailoring the properties of the PZT powder phase. However, the piezoelectric constants showed a tendency different to those of the raw powders, because of the poor poling degree. This was overcome by conducting poling at a high temperature.
ARTICLE | doi:10.20944/preprints202003.0283.v1
Subject: Engineering, Mechanical Engineering Keywords: piezoelectric ceramic; piezo-composite actuator; unimorph; piezoelectric single crystal; LIPCA
Online: 18 March 2020 (02:58:14 CET)
Research on piezo-composite actuators has been actively conducted over the past two decades as a response to strong demand for light, compact actuators to replace electro-magnetic motor actuators in micro robots, small flying drones, and compact missile systems. Layered piezo-composite unimorph actuators have been studied to provide active vibration control of thin-walled aerospace structures, control the shapes of aircraft wing airfoils, and control the fins of small missiles, because they require less space and provide better frequency responses than conventional electro-magnetic motor actuator systems. However, based on the limited actuation strains of conventional piezo-composite unimorph actuators with poly-crystalline piezoelectric ceramic layers, they have not been implemented effectively as actuators for small aerospace vehicles. In this study, a lightweight piezo-composite unimorph actuator (LIPCA-S2) was manufactured and analyzed to predict its flexural actuation displacement. It was found that the actuated tip displacement of a piezo-composite cantilever could be predicted accurately using the proposed prediction model based on the nonlinear properties of the piezoelectric strain coefficient and elastic modulus of a piezoelectric single crystal.
CASE REPORT | doi:10.20944/preprints202201.0193.v1
Subject: Engineering, Energy And Fuel Technology Keywords: piezoelectric tiles; school; sustainability; prototype
Online: 13 January 2022 (14:00:01 CET)
With the depletion of natural resources, it has become a topic of great concern to address the unsustainable way of life. In this study, we investigate the use of piezoelectric material - to generate electricity in schools. The use of these piezoelectric materials in floor tiles could enable us to generate energy from the footsteps of the children in school. The goal is to be able to power lights and fans in classrooms and reduce the consumption of conventional electricity - produced through the combustion of coal and other natural resources. The primary method of research is to develop a prototype with different choices of material and configurations of piezoelectric transducers to maximize power generation in a typical school setting. The results showed that the energy generated from one step needs to be improved by a factor of 100 for a typical classroom to generate enough power for a light and a fan. The research found that current technology although promising is incapable of producing enough power via piezoelectric tiles in a school setting.
COMMUNICATION | doi:10.20944/preprints202107.0492.v1
Subject: Engineering, Automotive Engineering Keywords: ecofriendly; piezoelectric; composite; material; 3Dprinting
Online: 21 July 2021 (12:12:24 CEST)
One century ago, ferroelectricity and then piezoelectricity were discovered using Rochelle salt crystals. Today, modern societies are invited to switch towards a resilient and circular economy model. In this context, this work proposes a method to manufacture piezoelectric devices made from agro-resources such as tartric acid and polylactide significantly reducing the energy budget without requiring any sophisticated equipement. These piezoelectric devices are manufactured by liquid phase epitaxy grown Rochelle salt (RS) crystals into a 3D printed poly(Lactic acid) (PLA) matrix being the artificial squared meshes which mimic the natural wood anatomy. This composite material can easily be produced in any fablab with renewable materials and at low processsing temperatures, reducing then the total energy consumed. Manufactured biodegradable samples are fully recyclable and have good piezoelectric properties without any pooling step. The measured piezoelectric coefficients of manufactured samples are higher than many piezoelectric polymers such as PVDF-TrFE.
ARTICLE | doi:10.20944/preprints201801.0159.v2
Subject: Engineering, Mechanical Engineering Keywords: harvester; piezoelectric; dynamic vibration absorber; trimming
Online: 13 March 2018 (04:42:34 CET)
Piezoelectric cantilever harvesters have a large power output at their natural frequency, but in some applications the frequency of ambient vibrations is different from the harvester’s frequency and/or ambient vibrations are periodic with some harmonic components. To cope with these operating conditions harvesters with integrated trimming devices (ITDs) are proposed. Some prototypes are developed with the aid of an analytical model and tested with an impulsive method. Results show that a small trimming device can lower the main resonance frequency of a piezoelectric harvester of the same extent as a larger tip mass and moreover generates at high frequency a second resonance peak. A multi-physics numerical FE model is developed for predicting the generated power and for performing stress-strain analysis of harvesters with ITDs. The numerical model is validated on the basis of experimental results. Several configurations of ITDs are conceived and studied. Numerical results show that harvesters with ITDs are able to generate relevant power at two frequencies owing to the particular shape of the modes of vibration. The stress in the harvesters with ITDs is smaller than the stress in the harvester with a tip mass trimmed to the same frequency.
ARTICLE | doi:10.20944/preprints201708.0005.v1
Subject: Engineering, Mechanical Engineering Keywords: piezoelectric; actuator; nano-positioning; flexure hinge; FEM
Online: 3 August 2017 (05:50:16 CEST)
A compact 2-DOF (two degrees of freedom) piezoelectric-driven platform for 3D cellular bio-assembly systems has been proposed based on “Z-shaped” flexure hinges. Multiple linear motions with high resolution both in x and y directions are achieved. The “Z-shaped” flexure hinges and the parallel-six-connecting-rods structure are utilized to obtain the lowest working stress while compared with other types of flexure hinges. In order to achieve the optimized structure, matrix-based compliance modeling (MCM) method and finite element method (FEM) are used to evaluate both the static and dynamic performances of the proposed 2-DOF piezoelectric-driven platform. Experimental results indicate that the maximum motion displacements for x stage and y stage are lx=17.65 μm and ly=15.45 μm, respectively. The step response time for x stage and y stage are tx=1.7 ms and ty =1.6 ms, respectively.
ARTICLE | doi:10.20944/preprints201702.0078.v1
Subject: Engineering, Energy And Fuel Technology Keywords: AC-DC converters; energy harvesting; piezoelectric; rectifier
Online: 20 February 2017 (18:23:13 CET)
Herein, we present the design technique of a resonant rectifier for piezoelectric (PE) energy harvesting. We propose two diode equivalents to reduce the voltage drop in the rectifier operation, a minuscule-drop-diode equivalent (MDDE) and a low-drop-diode equivalent (LDDE). The diode equivalents are embedded in resonant rectifier integrated circuits (ICs), which use symmetric bias-flip to reduce the power wasted for charging and discharging the internal capacitance of a PE transducer. The self-startup function is supported by synchronously generating control pulses for the bias-flip from the PE transducer. Two resonant rectifier ICs, using both MDDE and LDDE, are fabricated in a 0.18 μm CMOS process and their performances are characterized under external and self-power conditions. Under the external-power condition, the rectifier using LDDE delivers an output power POUT of 564 μW and a rectifier output voltage VRECT of 3.36 V with a power conversion efficiency (PCE) of 90.1%. Under self-power conditions, the rectifier using MDDE delivers a POUT of 288 μW and a VRECT of 2.4 V with a corresponding PCE of 74.6%. The result shows that the power extraction capability of the proposed rectifier is 5.9 and 3.0 times higher than that of a conventional full-bridge rectifier.
ARTICLE | doi:10.20944/preprints202104.0198.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: (Bi0.5Na0.5)TiO3-BaTiO3; Electrocaloric effect; Lead-free piezoelectric
Online: 7 April 2021 (11:46:41 CEST)
Considering that the electric refrigeration temperature range of 0.94BNT-0.06BT ceramic materials is 100~140˚C, the electric refrigeration performance of the 0.94BNT-0.06BT ceramic material system was modified by LiNbO3 doping to reduce the cooling temperature. As a result, the refrigeration temperature range of the 0.94BNT-0.06BT ceramic material system was lowered to 25~80 ˚C, achieving its cooling effect near room temperature, and in this temperature range, the adiabatic temperature changes ∆T>0.6K.
REVIEW | doi:10.20944/preprints202011.0262.v1
Subject: Engineering, Mechanical Engineering Keywords: PVDF; piezoelectric polymer; wearable device; flexible sensor; electromechanical
Online: 9 November 2020 (08:31:08 CET)
The technological development of piezoelectric materials is crucial for developing wearable and flexible electromechanical devices. There are many inorganic materials with piezoelectric effects, such as piezoelectric ceramics, aluminum nitride, and zinc oxide. They all have very high piezoelectric coefficients and large piezoelectric response ranges. The characteristics of high hardness and low tenacity make inorganic piezoelectric materials unsuitable for flexible devices that require frequent bending. Polyvinylidene fluoride (PVDF) and its derivatives are the most popular materials used in flexible electromechanical devices in recent years and have high flexibility, high sensitivity, high ductility, and a certain piezoelectric coefficient. Owing to increasing the piezoelectric coefficient of PVDF, researchers are committed to optimizing PVDF materials and enhancing their polarity by a series of means to further improve their mechanical–electrical conversion efficiency. This paper reviews the latest PVDF-related optimization materials, related processing and polarization methods, and the applications of these materials such as those in wearable functional devices, chemical sensors, biosensors, and flexible actuator devices for flexible micro-electromechanical devices. We also discuss the challenges of wearable devices based on flexible piezoelectric polymer, consider where further practical applications could be.
ARTICLE | doi:10.20944/preprints201808.0182.v2
Subject: Engineering, Mechanical Engineering Keywords: Vibration Control, Piezoelectric, Fuzzy Logic Control, Launch Vehicle
Online: 21 December 2018 (11:12:32 CET)
Satellites are subject to various severe vibration during different phases of flight. The concept of satellite smart adapter is proposed in this study to achieve active vibration control of launch vehicle on satellite. The satellite smart adapter has 18 active struts in which the middle section of each strut is made of piezoelectric stack actuator. Comprehensive conceptual design of the satellite smart adapter is presented to indicate the design parameters, requirements and philosophy applied which are based on the reliability and durability criterions to ensure successful functionality of the proposed system. The coupled electromechanical virtual work equation for the piezoelectric stack actuator in each active strut is drived by applying D'Alembert's principle. Modal analysis is performed to characterize the inherent properties of the smart adapter and extraction of a mathematical model of the system. Active vibration control analysis was conducted using fuzzy logic control with triangular membership functions and acceleration feedback. The control results conclude that the proposed satellite smart adapter configuration which benefits from piezoelectric stack actuator as elements of its 18 active struts has high strength and shows excellent robustness and effectiveness in vibration suppression of launch vehicle on satellite.
ARTICLE | doi:10.20944/preprints201609.0064.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: PZT-PVDF; coupling agents; dielectric properties; piezoelectric properties
Online: 19 September 2016 (09:42:46 CEST)
PZT-Poly(vinylidene fluoride) composites were prepared by hot-pressing method. Before addition, PZT particles were firstly modified with two different coupling agents. The micromorphology, microstructure, dielectric properties, and piezoelectric properties of the composites were characterized and investigated. Results indicated that PZT particles were homogeneously dispersed in the PVDF matrix by the addition of coupling agents. The electric properties of PZT-PVDF composites with NDZ-101 were the best. Especially when the volume ratio of the titanate coupling agent NDZ-101 was 1%, the piezoelectric strain constant d33 of PZT-PVDF composites reached maximum value 19.23pC/N; its relative dielectric constant εr was 67.45; at the same time its dielectric loss tanδ was 0.0766.
ARTICLE | doi:10.20944/preprints202209.0421.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: electrospinning; microfibers; piezoelectric crystals; nitroanilines; fluorescence; functional organic materials
Online: 27 September 2022 (10:22:10 CEST)
N,N-dimethyl-4-nitroaniline (NNDM4NA, C8H10O2N2), is a superelastic and superplastic charge-transfer molecular crystal with a high molecular dipole moment, µ=7.95 D, which crystal-lizes in the acentric polar point group 2. Highly aligned poly-l-lactic acid (PLLA) polymer micro-fibers with embedded NNDM4NA nanocrystals were fabricated using the electrospinning tech-nique. The composite fibers display an extraordinarily high piezoelectric output response, where for a small stress of 5.0x103 Nm-2, an effective piezoelectric voltage coefficient of geff=3.6 VmN-1 was obtained. The fibers were found to display solid state blue fluorescence with a long (147 ns) life-time decay. Furthermore, the composite fibers exhibit an average increase of 67% on the Young modulus reaching 55 MPa, while the tensile strength reaches 2.8 MPa when compared with solely PLLA fibers. The results show that nanocrystals, from small organic molecules, with elastic and piezoelectric properties form hybrid functional 2-dimensional luminescent array which are me-chanical strong and generate high output voltages making them promising for applications in energy harvesting and as solid-state blue emitters.
ARTICLE | doi:10.20944/preprints201806.0140.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: Silicon dioxide, Piezoelectric device, Zinc oxide, RF sputtering deposition
Online: 8 June 2018 (14:00:29 CEST)
In this paper, we present a study of various ZnO/SiO2-stacked thin film structures for flexible micro-energy harvesting devices. Two groups of micro-energy harvesting devices, SiO2/ZnO/SiO2 micro-energy generators (SZS-MGs) and ZnO/SiO2/ZnO micro-energy generators (ZSZ-MGs), were fabricated by stacking both SiO2 and ZnO thin films, and the resulting devices were characterized. With a particular interest in the fabrication of flexible devices, all the ZnO and SiO2 thin films were deposited on ITO-coated PEN substrates using an RF magnetron sputtering technique. The effects of the thickness and/or position of the SiO2 films on the device performance were investigated by observing the variations of output voltage in comparison with that of a control sample. As a result, compared to the ZnO single-layer device, all the ZSZ-MGs showed much better output voltages, while all the SZS-MG showed only slightly better output voltages. Among the ZSZ-MGs, the highest output voltages were obtained from the ZSZ-MGs where the SiO2 thin films were deposited using a deposition power of 150 W. Overall, the device performance seems to depend significantly on the position as well as the thickness of the SiO2 thin films in the ZnO/ SiO2-stacked multilayer structures, in addition to the processing conditions.
ARTICLE | doi:10.20944/preprints202306.2018.v1
Subject: Engineering, Mechanical Engineering Keywords: Energy harvesting; micro-channel flow; CFD; piezoelectric phenomenon; bluff body.
Online: 28 June 2023 (11:37:13 CEST)
A micro energy harvesting device proposed in the literature, is numerically studied. It consists of two bluff bodies in a micro-channel and a flexible diaphragm at its upper wall. Vortex shedding behind bodies induces pressure fluctuation causing vibration of the diaphragm that converts me-chanical energy to electrical by means of a piezoelectric membrane. Research on enhancing vortex shedding is justified due to the low power output of the device. Amplitude and frequency of un-steady pressure fluctuation on the diaphragm center are numerically predicted. Vortex shedding severity is mainly assessed in terms of pressure amplitude. The CFD model set-up is described in detail and appropriate metrics to assess energy harvesting potential are defined. Several cases are simulated to study the effect of inlet Reynolds number and channel blockage ratio on the prospec-tive performance of the device. Furthermore, the critical blockage ratio leading to vortex shedding suppression is sought. Higher inlet velocity for a constant blockage ratio is found to enhance vor-tex shedding and pressure drop. Great blockage ratio values, but lower than the critical one, seem to provide great pressure amplitudes in the expense of moderate pressure drop. There is evidence that the field is fruitful for research and relevant directions are provided.
ARTICLE | doi:10.20944/preprints202103.0786.v3
Subject: Chemistry And Materials Science, Biomaterials Keywords: Smart textile piezoelectric; Polyvinylidene fluoride; energy harvesting; self-powered sensors
Online: 22 April 2021 (21:11:26 CEST)
The field of power harvesting has experienced significant growth over the past few years due to the ever-increasing desire to produce portable and wireless electronics with extended lifespans. The present work aims to introduce an approach to harvesting electrical energy from a mechanically excited piezoelectric element and investigates a power analytical model generated by a smart structure of type polyvinylidene fluoride(PVDF) that can be stuck onto fabrics and flexible substrates, although we report the effects of various substrates and investigates the sticking of these substrates on the characterization of the piezoelectric material.
ARTICLE | doi:10.20944/preprints201802.0168.v1
Subject: Engineering, Mechanical Engineering Keywords: powder handling, flowability, dosing, transport, mixing, dispersion, piezoelectric actuators, vibrations
Online: 26 February 2018 (16:00:40 CET)
Since fine powders tend strongly to adhesion and agglomeration, their processing with conventional methods is difficult or impossible. Typically, in order to enable the handling of fine powders, chemicals are added to increase the flowability and reduce adhesion. This contribution shows that instead of additives also vibrations can be used to increase the flowability, to reduce adhesion and cohesion, and thus to enable or improve processes such as precision dosing, mixing, and transport of very fine powders. The methods for manipulating powder properties are described in detail and prototypes for experimental studies are presented. It is shown that the handling of fine powders can be improved by using low-frequency, high-frequency or a combination of low- and high-frequency vibration.
ARTICLE | doi:10.20944/preprints202309.0687.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: composite films; chitosan; NBT; dielectric properties; local piezoelectric response; optical properties
Online: 12 September 2023 (05:45:29 CEST)
The purpose of this research work was to synthesis bio-derived nanocomposite films by incorporating Na0.5Bi0.5TiO3 (NBT) nanoparticles into Chitosan matrix. The NBT nanoparticles were synthesized using a traditional solid-state technique. Then, through a solution casting approach, flexible composite films were fabricated using Chitosan polymer. The morphology and structural assessments were carried out utilizing scanning electron microscopy (SEM), X-ray diffraction and fourier transform infrared technique. The SEM micrographs showed that NBT nanoparticles were randomly distributed and interconnected with other particles, forming interconnected grains with substantial interspaces within the matrix. The spectral response between 300 and 800 nm of the composites is mainly governed by light scattering of NBT particles with diameter sizes in the 100 - 400 nm range and the bandgap of the NBT phase. The dielectric studies demonstrated that the composite films exhibited higher dielectric values compared to the pure Chitosan film. Besides, the increase of NBT amount was found to increase the dielectric values. Additionally, local piezoelectric measurements reveal the expected piezoelectric and ferroelectric behavior for the NBT particles dispersed into the polymer matrix, as locally probed by Piezoresponse Force Microscopy. The studied system bears interest for advanced biocompatible opto- and piezo-electric materials.
ARTICLE | doi:10.20944/preprints201910.0244.v1
Subject: Engineering, Mechanical Engineering Keywords: adaptive lens; piezoelectric devices; fluid-structure interaction; moving mesh; thermal expansion.
Online: 21 October 2019 (13:02:57 CEST)
In this paper, we present a finite element simulation of an adaptive piezoelectric fluid-membrane lens modeled in COMSOL Multiphysics. The simulation couples the piezoelectric effect with the fluid dynamics to model the interaction between piezoelectric forces and fluid forces. Also, the simulation is extended to model the thermal expansion of the fluid. Finally, we compare the simulation and experimental results of the adaptive lens refractive power at different actuation levels and temperatures.
REVIEW | doi:10.20944/preprints201611.0055.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: hybridization analysis; nucleic acids; optical biosensors; electrochemical biosensors; micromechanical (piezoelectric) sensors
Online: 9 November 2016 (10:28:58 CET)
In review, the operating principles of the most common bio sensing devices, detection methods and the identification sensitivity of analyzed molecules were shown. The central focus was done on hybridization analysis of nucleic acids (NA), which are considered to be one of the most important analytes in terms of diagnostic point of view. Constructions enabling to transfer the fact of formation of nucleotide probe/target complex in to detectable signal by optical, electrochemical or micromechanical (piezoelectric) sensors were presented in this review.
ARTICLE | doi:10.20944/preprints202012.0018.v1
Subject: Engineering, Automotive Engineering Keywords: piezoelectric nanotransducers; depletion piezopotential; enhancement piezopotential; base piezopotential; tip piezopotential; characteristic lengths of piezopotentials; depletion-to-enhancement piezopotential ratio; tip-to-base piezopotential ratio; piezoelectric nanogenerators; piezotronics.
Online: 1 December 2020 (12:41:04 CET)
Piezoelectric nanotransducers may offer key advantages in comparison with conventional piezoelectrics, including more choices for types of mechanical input, positions of the contacts, dimensionalities and shapes. However, since piezo-semiconductive nanostructures are generally much easier to fabricate and integrate into functional systems than insulating materials, modeling becomes significantly more intricate and the effects of free charges have been considered only in a few studies. The available reports are complicated by the absence of proper nomenclature and figures of merit. Besides, some analyses are incomplete. For instance, the local piezopotential and free charges within axially strained conical piezo-semiconductive nanowires have only been systematically investigated for very low doping (1016 cm-3) and under compression. Here we give the definitions for the enhancement, depletion, base and tip piezopotentials, their characteristic lengths and both the tip-to-base and the depletion-to-enhancement piezopotential-ratios. As an example, we use these definitions for analyzing the local piezopotential and free charges in n-type ZnO truncated conical nanostructures with different doping levels (intrinsic, 1016 cm-3, 1017 cm-3) for both axial compression and traction. The definitions and concepts presented here may offer insight for designing high performance piezosemiconductive nanotransducers.
ARTICLE | doi:10.20944/preprints202308.1677.v1
Subject: Engineering, Architecture, Building And Construction Keywords: concrete slab; damage detection; folded roof plate; piezoelectric sensor; structural health monitoring
Online: 23 August 2023 (12:57:34 CEST)
With demand for the long-term continued use of existing building facilities, structural health monitoring and damage detection are attracting interest from society. Sensors of various types have been practically applied in the industry to satisfy this need. Among the sensors, piezoelectric sensors are an extremely promising technology by virtue of their cost advantages and durability. Although they have been used in aerospace and civil engineering, their application for building engineering remains limited. Remarkably, recent catastrophic seismic events have further rein-forced the necessity of rapid damage detection and quick judgment about the safe use of facilities. Faced with these circumstances, this study was conducted to assess the applicability of piezoelectric sensors to evaluate building components. Specifically, this study emphasizes structural damage caused by earthquakes. After first applying to cyclic loading tests to composite beam component specimens and steel frame subassemblies with a folded roof plate, the prospective damage posi-tions were also found using finite element analysis. Crack propagation and buckling locations were predicted adequately. The piezoelectric sensors provided output when the concrete slab showed tensile cracks, or when the folded roof plate experienced local buckling. Furthermore, damage expansion and progression were detected multiple times during loading tests. Results showed that the piezoelectric sensors can detect structural damage of building components, demonstrating their potential for use in inexpensive and stable monitoring systems.
ARTICLE | doi:10.20944/preprints202305.2176.v1
Subject: Engineering, Aerospace Engineering Keywords: Composite structures; Structural health monitoring; Cross-correlation analysis; Guided waves; Piezoelectric sensors
Online: 31 May 2023 (07:09:47 CEST)
Statistical based reconstruction methods and signal processing tooling techniques are implemented and used to detect delaminations or debondings within composite items. From literature it appears that, although a single procedure for the estimation of the structural health is a fast solution, a multiple analysis based on different reconstruction methods or different damage parameters could provide more detailed information about the location and the severity of possible failures. This work discusses the advantage of using cross-correlation analysis in a data-driven approach based on ultrasonic guided waves (GW) tomographic technique and piezoelectrics (PWAS) in pitch-catch configuration. In this sense, this work evidences an improvement in damage detection when the cross-correlation is included as part of the GW-based system for damage assessment approach. The specimens used as test structures to demonstrate the validity of the methodology derive from an aircraft wing test article where damages are specified as skin delamination produced by low energy impact.
ARTICLE | doi:10.20944/preprints202304.0840.v1
Subject: Engineering, Mechanical Engineering Keywords: ZnO; multilayer film; vibration energy harvester; spray deposition; piezoelectric generator; nanostructured material
Online: 24 April 2023 (09:34:09 CEST)
Owing to the escalating adoption of IoT systems across various domains, the demand for mobile and wireless power sources has surged. Although conventional batteries typically serve as energy storage components, the current low-power consumption devices necessitate eco-friendly alterna-tives. In this study, we designed, fabricated, and characterized an energy harvesting device that repurposes mechanical vibrations. A three-beam design was employed to harvest energy across a broader range of potential frequencies. Finite element models were simulated to ascertain the first bending moment for both sets of beams. A nanostructured piezoelectric multilayer film made of ZnO was deposited onto an AISI 304 steel substrate, and a photosensitive resin seismic mass was implemented. Low-cost techniques generating minimal environmental waste were leveraged in the fabrication process. The piezoelectric film was deposited using a spray nebulization technique involving recycled materials and cost-effective equipment. Micrographs of the layers unveiled the presence of nanospheres with diameters of 250 nm. Employing a custom-made shaker, output voltages of 1.08 V and 180 mV, and power outputs of 1.849 µW and 16.2 nW were achieved for each set of beams. The electrical characterization was conducted using a custom-made shaker, repurposing materials for this objective.
ARTICLE | doi:10.20944/preprints202304.0183.v1
Subject: Physical Sciences, Condensed Matter Physics Keywords: langasite; thermal expansion coefficients; X-ray powder diffraction; piezoelectric crystals; Czochralski method
Online: 11 April 2023 (03:38:49 CEST)
The ordered Ca3TaGa3Si2O14 and disordered La3Ga5SiO14 crystals of the lantangallium silicate family were grown by the Czochralski method. The independent coefficients of thermal expansion of crystals αc and αa were determined by X-ray powder diffraction based on the analysis of X-ray diffraction spectra measured in the temperature range of 25÷1000°C. It is shown that in the temperature range of 25÷800°C the thermal expansion coefficients are linear. At temperatures above 800°C there is a nonlinear character of the thermal expansion coefficients associated with a decrease in the Ga content in the crystal lattice of the lantangallium silicate family crystals.
ARTICLE | doi:10.20944/preprints202302.0338.v1
Subject: Medicine And Pharmacology, Anesthesiology And Pain Medicine Keywords: Piezoelectric; Piezocapacitive; Pulse transit time; Non-invasive hemodynamics; Intraoperative blood pressure; Anesthesiology
Online: 20 February 2023 (09:43:32 CET)
Abstract: Background: Non-invasive acquistion of beat-to-beat pulse transit time (PTT) via piezoelectric/piezocapacitive sensors (PES/PCS) may expand perioperative hemodynamic monitoring. This study evaluated the ability for PTT via PES/PCS to correlate with systolic, diastolic, and mean invasive blood pressure (SBPIBP, DBPIBP, and MAPIBP) and to detect SBPIBP fluctuations. Methods: PES/PCS and IBP measurements were performed in 20 patients undergoing abdominal, urological, and cardiac surgery. A Pearson’s correlation analysis (r) between 1/PTT and IBP was performed. The predictive ability of 1/PTT with changes in SBPIBP was determined by area under the curve (reported as AUC, sensitivity, specificity). Results: Significant correlations between 1/PTT and SBPIBP were found for PES (r=0.64) and PCS (r=0.55) (p<0.01), as well as MAPIBP/DBPIBP for PES (r=0.6/0.55) and PCS (r=0.5/0.45) (p<0.05). A 7% decrease in 1/PTTPES predicted a 30% SBPIBP decrease(0.82, 0.76, 0.76), while a 5.6% increase predicted a 30% SBPIBP increase (0.75, 0.7, 0.68). A 6.6% decrease in 1/PTTPCS detected a 30% SBPIBP decrease (0.81, 0.72, 0.8), while a 4.8% 1/PTTPCS increase detected a 30% SBPIBP increase (0.73, 0.64, 0.68). Conclusions: Non-invasive beat-to-beat PTT via PES/PCS demonstrated significant correlations with IBP and detected significant changes in SBPIBP. Thus PES/PCS as a novel sensor technology may augment intraoperative hemodynamic monitoring during major surgery.
ARTICLE | doi:10.20944/preprints201808.0336.v1
Subject: Engineering, Civil Engineering Keywords: preload monitoring; bolted connection; bolt-loosening; piezoelectric sensor; impedance response; smart interface
Online: 18 August 2018 (11:09:35 CEST)
In this study, a preload monitoring method using impedance signatures obtained from a piezoelectric-based smart interface is presented for bolted girder connections. Firstly, the background theory of the piezoelectric-based smart interface and its implementation into health monitoring of bolted connections are outlined. A simplified electro-mechanical (EM) impedance model of a smart interface-embedded bolted connection system is formulated to interpret mechanistic understanding of EM impedance signatures under the effect of bolt preload. Secondly, finite element modeling of a bolted connection is carried out to show the numerical feasibility of the presented method and to predetermine the sensitive frequency band of impedance signatures. Finally, impedance measurements are conducted on a lab-scaled bolted girder connection to verify the predetermined sensitive frequency range and to assess the bolt preload changes in the test structure.
ARTICLE | doi:10.20944/preprints201804.0383.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: III-N Nanowires; Piezoelectric generation; Atomic force microscope; Piezo-generators; Energy harvesting
Online: 30 April 2018 (18:31:29 CEST)
We demonstrate for the first time efficient mechanical to electrical energy conversion using InGaN/GaN nanowires (NWs). Using an atomic force microscope equipped with a modified Resiscope module, we analyse the piezoelectric energy generation of GaN NWs and demonstrate an important enhancement when integrating in their volume a thick In-rich InGaN insertion. The piezoelectric response of InGaN/GaN NWs can be tuned as a function of the InGaN insertion thickness and position in the NW volume. The energy harvesting is favoured by the presence of a PtSi/GaN Schottky diode which allows to efficiently collect the piezo-charges generated by InGaN/GaN NWs. Average output voltages up to 330 ± 70 mV and a maximum value of 470 mV per NW has been measured for nanostructures integrating 70 nm-thick InGaN insertion capped with a thin GaN top layer. This latter value establishes an increase of about 35% of the piezo-conversion capacity in comparison with binary p-doped GaN NWs. By considering these output signals, we estimate a maximum power density generated by one layer of dense InGaN/GaN-based NW of about 3.3 W/cm2. These results settle the new state-of-the-art for piezo-generation from GaN-based NWs and offer a promising perspective for extending the performances of the piezoelectric sources.
ARTICLE | doi:10.20944/preprints202210.0236.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: organic lead-free perovskites; piezoelectric crystals; nanofiber composites; electrospinning; blue luminescence; functional organic materials
Online: 17 October 2022 (11:51:08 CEST)
Lead-free ferroelectric perovskite N-methyl-N'-diazabicyclo[2.2.2]octonium)–ammonium triio-dide, MDABCO-NH4I3, nanocrystals are embedded in three different polymer fibers fabricated by the electrospinning technique. The nanofibers, which are very flexible and have a high Young modulus, behave as active piezoelectric energy harvesting sources that produce a piezoelectric voltage coefficient up to geff = 3.6 VmN-1 and show a blue intense luminescence band at 325 nm. In this work, the pyroelectric coefficient is reported for the MDABCO-NH4I3 perovskite inserted in electrospun fibers. At the ferroelectric-paraelectric phase transition, the embedded nanocrystals display a pyroelectric coefficient as high as 194×10-6 Cm-2k-1, within the same order of magnitude as that reported for the state-of-the-art bulk ferroelectric triglycine sulfate (TGS). The perovskite nanocrystals embedded into the polymer fibers remain stable, and no degradation is caused by oxidation.
ARTICLE | doi:10.20944/preprints202107.0102.v1
Subject: Engineering, Industrial And Manufacturing Engineering Keywords: accelerometer; process monitoring; natural frequencies; ball burnishing; ultrasonic; piezoelectric; acoustic emission; operational deflection shape.
Online: 5 July 2021 (14:04:48 CEST)
In this paper, a resonant system that produces a movement of low amplitude and ultrasonic frequency is used to achieve the vibration assistance in a ball-burnishing process. A full vibration characterization of this process performed in a lathe was done. It is carried out by a new tool designed in the research group of the authors. Its purpose is to demonstrate that the machine and the tool do not have any resonance problem during the process and to prevent possible failures. The analysis of this dynamic behaviour permits to validate the suitability of the tool when it is anchored to a numerical control lathe. This is very important for its future industrial implementation. It is also intended to confirm that the system adequately transmits vibrations through the material. To do this, a methodology to validate the dynamic tool behaviour was developed. Several techniques that combine the usual and ultrasonic vibration ranges through static and dynamic measurements were merged: vibration and acoustic emission measurements. An operational deflection shape (ODS) exercise has been also performed. Results show the suitability of the tool used to transmit the assistance vibrations, and that no damage is produced in the material in any case.
ARTICLE | doi:10.20944/preprints202101.0372.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: Piezoelectric energy harvester; AC magnetic field; Lead-free material; Sustainable energy; High energy conversion
Online: 19 January 2021 (10:56:47 CET)
A high-performance Lead-free Piezoelectric Energy Harvester (LPEH) based on a Ba0.85Ca0.15Ti0.90Zr0.10O3 + CuO 0.3 wt% (BCTZC0.3) composite was fabricated by sintering at 1450℃. The BCTZC0.3 composite, which has an enhanced high-energy-conversion constant (〖d_33×g〗_33), shows improved piezoelectric power-generation performance when compared with conventional piezoelectric energy harvesters. The BCTZC0.3-based LPEH produces instantaneous maximum power of 8.2 mW and an energy density of 107.9 mW/cm3 in a weak magnetic field of 250 μT. This energy harvester can be used to charge a capacitor and operate a wireless sensor network (WSN) system to provide temperature sensing and radio-frequency (RF) transmission in a 250 μT magnetic field. The proposed LPEH is a promising green-energy device for potentially self-powering WSN systems when applied.
ARTICLE | doi:10.20944/preprints201905.0265.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: PZT; mixed-oxides techniques; dielectric properties; piezoelectricity; ultrasonic piezo-motor; piezoelectric cylinder; numerical simulation
Online: 22 May 2019 (08:41:12 CEST)
First of all the paper presents a solid solution of piezoelectric ceramic that was synthesized according to the general formula Pb(1-x)Srx(Ti0.48Zr0.52)(1-y)NbyO3 with x = 0.05 and y = 0.02, using wet ceramic processing technology and using an oxide mix as prime material. The effects of dopants (Sr2+ and Nb5+) on phase constitution, on microstructure and on the dielectric and piezoelectric properties were determinate. The Zr/Ti ratio was chosen near the morphotropic phase boundary of the PZT system in studied composition. The XRD data revealed that the PZT doped composition had tetragonal perovskite structure. Secondly the paper presents the design of the novel piezo-motor based on a surface wave which translates the linear extension of different piezoelectric segments of a piezoelectric cylinder into a rotational bending movement. This rotational bending of the piezoelectric cylinder is then transformed into a continuous rotation of the rotor through a calculated contact. The design of the motor takes advantage of the high piezoelectric constants of the developed material in an optimal way in order to increase the energetic efficiency. A brief mathematical model of electromechanical answer of piezoelectric materials is presented as it was used in the modeling of the material during the numerical simulations.
ARTICLE | doi:10.20944/preprints202308.0532.v1
Subject: Engineering, Civil Engineering Keywords: Concrete-filled steel tubular; Travel time tomography; Piezoelectric lead zirconate titanate; Defect imaging; Parameter analysis
Online: 8 August 2023 (03:31:38 CEST)
Concrete-filled steel tube (CFST) members have been widely used in the field of civil engineering due to their advanced superior mechanical properties. However, internal defects such as concrete core voids and interface debonding are likely to weaken the load-carrying capacity and stiffness of these members, which affects safety and serviceability of CFST structures. Visualizing the inner defects of concrete core in CFST members have been a critical need in civil engineering construction, a travel time tomography (TTT) is introduced to quantitatively identify and visualize the sizes and positions of CFST members in this paper. Moreover, a parameter analysis is performed to investigate the relationship between TTT imaging qualities and influence factors, e.g. inversion parameters, defect sizes and positions. The effectiveness and accuracy of the TTT algorithm are verified by several numerical examples and the results demonstrate that TTT can identify the sizes and positions of concrete core void defects in CFST members efficiently and several inversion parameters including model weighting matrix and inversion grid size really pose a significant impact on the imaging results of CFST members. In addition, several optimum parameters are recommended to benefit the future study of the promising TTT approach for CFST members.
ARTICLE | doi:10.20944/preprints202104.0595.v1
Subject: Engineering, Automotive Engineering Keywords: real-time electronics; structural health monitoring; Lamb wave; piezoelectric sensors; impact localization, ultrasonic guided waves
Online: 22 April 2021 (09:14:03 CEST)
The work presents a Structural Health Monitoring (SHM) electronic system with real-time ac-quisition and processing for the determination of impact location in laminates. The novelty of this work is the quantitative evaluation of impact location errors using the Lamb wave guided mode S0, captured and processed in real-time by up to eight piezoelectric sensors. The differential time of arrival is used to minimize an error function for the position estimation. The impact energy is correlated to the amplitudes of the antisymmetric (A0 ) mode and the electronic design is de-scribed to avoid saturation for signal acquisition. The same electronic is designed to acquire symmetric (S0 ) low level signals by adequate gain, bandwidth and signal to noise ration. Such signals propagate into a 1.4mm thick aluminum laminate at the group velocity of 5150m/s with frequency frequency components above 270kHz and can be discriminated from the A0 mode to calculate accurately the differential arrival time. The results show that the error is not improved better than S0 wavelength in impact localization by using six out of eight sensors connected to the electronic system.
ARTICLE | doi:10.20944/preprints201907.0272.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: ambient human energy, piezoelectric energy harvester, RC circuit model, self-powered device, wireless PPG sensor
Online: 24 July 2019 (11:50:43 CEST)
A new circuit model of the self-powered device for heart rate measurement is presented in this paper. This device consists of piezoelectric energy harvester (PEH), power management circuit (PMC) with energy storage, microcontroller, Photoplethysmography (PPG) sensor, and Wi-Fi module. The PEH is placed under the insole to harvest the pressure energy from human foot-step to generate ac power. In our model, a PEH is represented by sine voltage source, where its parameters were taken from experiments with 20 volunteers. The PMC is simplified by a switch with gain δ placed in series with the main circuit. The model of the main circuit is RC elements in parallel, where C is the capacitance of the storage device, and R is the equivalent parallel resistance of the microcontroller, PPG sensor, and Wi-Fi modules, respectively. The value of R depends on the power and current absorbed by those modules during sleep, deep sleep, sense, and transmit modes which collected from the datasheet. Finally, the proposed circuit model of the self-powered device was built and simulated in SPICE. The simulation results were compared with the laboratory experiment using commercial devices. Based on the results, the proposed model had small gaps compared to the real self-powered devices in terms of average current, voltage, power and efficiency.
ARTICLE | doi:10.20944/preprints201712.0067.v1
Subject: Engineering, Mechanical Engineering Keywords: semi-analytical solutions; hydrodynamic characteristics; piezoelectric cantilever beam; wave energy harvesters; lumped and structural parameters.
Online: 11 December 2017 (15:25:30 CET)
We mainly describe the influence factors of captured power by huge wave energy harvesters, which the vertical motion of buoy can transform ocean’s potential energy into piezoelectric energy power by waves. By means of semi-analytical solutions and theoretical analysis, related environmental coefficients are analyzed firstly and find the most appropriate wave frequency and geometric structure as reference. Secondly, the numerical results also discuss the impact trend of hydrodynamic parameters and geometric volume on motion, voltage and power with qualitative agreement. The simulation data confirm that structure parameters of the modified model could markedly deliver sufficient power to ocean high electrical equipment with long-time stability.
ARTICLE | doi:10.20944/preprints201810.0522.v1
Subject: Engineering, Mechanical Engineering Keywords: composite; piezoelectric sensor; thick film; sol-gel PMOD deposition; infiltration; PZT/PZT; PZT/BiT; characterization; structural health monitoring; aerospace structure
Online: 23 October 2018 (06:25:30 CEST)
The composition of fine-ground lead zirconate-titanate powder Pb(Zr0.52Ti0.48)O3, suspended in PZT and bismuth titanate (BiT) solutions, is deposited on the curved surface of IN718 and IN738 nickel-based supper alloy substrates up to 100 µm thickness. Photochemical metal organic and infiltration techniques are implemented to produce smooth, semi-dense, and crack-free random orientated thick piezoelectric films as piezo-sensors, free of any dopants or thickening polymers. Every single layer of the deposited films is heated at 200 °C with 10 wt.% excess PbO, irradiated by UV lamp (365 nm, 6 watt) for 10 minutes, pyrolyzed at 400 °C, and subsequently annealed at 700 °C for one hour. This process is repeated successively until reaching the desired thickness. Au and Pt thin films are deposited as the bottom and top electrodes using evaporation and sputtering methods, respectively. PZT/PZT and PZT/BiT composite films are then characterized and compared to similar PZT and BiT thick films deposited on the similar substrates. The effect of composition and deposition process is also investigated on the crystalline phase development and microstructure morphology as well as dielectric, ferroelectric and piezoelectric properties of piezo-films. The maximum remnant polarization of Pr = 22.37 ± 0.01, 30.01 ± 0.01 µC/cm2, the permittivity of εr = 298 ± 3, 566 ± 5 and piezoelectric charge coefficient of d33 = 126, 148 m/V were measured versus the minimum coercive field of Ec = 50, 20 kV/cm for the PZT/PZT and PZT/Bit thick films, respectively. The thick film piezo-sensors are developed to be potentially used at frequency bandwidth of 1–5 MHz for rotary structural health monitoring and also in other industrial or medical applications as a transceiver.
ARTICLE | doi:10.20944/preprints201804.0103.v1
Subject: Engineering, Control And Systems Engineering Keywords: piezoelectric micro-energy harvester; lead zirconate titanate; bandwidth broadening; coupled cantilevers; enhanced stress distribution; finite element modeling; microelectromechanical systems (MEMS)
Online: 9 April 2018 (09:51:06 CEST)
This paper presents a demonstration of the feasibility of fabricating micro-cantilever harvesters with extended stress distribution and enhanced bandwidth by exploiting an M-shaped two-degrees-of-freedom design. The measured mechanical response of the fabricated device displays the predicted dual resonance peak behavior with the fundamental peak at the intended frequency. This design has the features of high energy conversion efficiency in a miniaturized environment where the available vibrational energy varies in frequency. It makes such a design suitable for future large volume production of integrated self powered sensors nodes for the Internet-of-Things.
ARTICLE | doi:10.20944/preprints202103.0515.v1
Subject: Computer Science And Mathematics, Mathematics Keywords: efficient ultrasonic transceivers, broadband piezoelectric transducers, industrial NDE, medical imaging, pulsed high-power spikes, HV capacitive-discharge pulsers, high-current driving, high dynamic range.
Online: 22 March 2021 (11:16:39 CET)
Ultrasonic imaging & NDE applications can greatly improve their signal-to-noise ratios (SNR) by driving each transducer (composing piezoelectric arrays) with a spike giving pulsed power of k-Watts, repetitively at a PRF = 5000 spikes/s, by using a HV capacitive-discharge generator. However very-high levels, of pulsed intensities (3-10 A) and voltages (300-700 V) must be considered for a rigorous spike modeling. Even though the consumed "average" power will be small, the intensity through each transducer achieves several amperes, so the pulsed powers delivered by each HV generator can attain levels higher than in CW high-power ultrasonic applications: e.g., up to 5 kW / spike. This is concluded here from a transient modeling of the loaded generator. Then, unforeseen phenomena rise: intense brief pulses of driving power & emitted force in transducers, and non-linearities in driver semiconductors, because their characteristic curves only include linear ranges. But fortunately, piezoelectric devices working in this intense regime do not show serious heating problems, because the average power remains being moderate. Intensity, power and voltage, driving a broadband transducer from a HV capacitive pulser, are calculated to drastically improve (in ≅ 40 dB) the ultrasonic net dynamic range available, with emitted forces ≅ 250 Newtons pp and E/R received pulses of 70 V pp.
Subject: Engineering, Electrical And Electronic Engineering Keywords: piezoelectric materials; piezoelement; 1-3 piezocomposite; resonance and antiresonance frequencies; quality Q-factor; surface acoustic wave (SAW); interdigital transducer (IDT); mass load; SAW resonator
Online: 31 December 2019 (16:01:57 CET)
A novel effective vibrational mode was discovered in the conventional transducer with an array of orthogonal (square) regular piezoelectric rods in 1-3 piezocomposite, containing the damping backing and front matching layers. The operational resonance in the structure was determined as the Surface Acoustic Wave (SAW) on the backing boundary excited by the adjacent piezo-rods, with its frequency typically near 3 times lower the fundamental half-lambda conventional piezocomposite resonance. Pulse-echo sensitivity and transmitting sound-pressure-level (SPL) in air showed that the signal strength is roughly comparable to the industrial similar air transducers at the frequency range 100…700 kHz, where at these frequencies the lateral and longitudinal piezoelement dimensions in the conventional transducer design are typically close to each other causing interference with unwanted coupling modes. As was determined theoretically and proved in experiments, the backing SAW resonance effect in the transducer performance is inherent just to the regular periodic 1-3 piezocomposite structure, and does occur neither with randomly located/oriented piezo-rods, nor in the homogeneous piezo-plate at least with the same lateral cross-section as the connected to it backing. The purpose of the article is to investigate a newly discovered operational vibrational mode of a SAW type in 1-3 regular piezocomposite, other than piezoelectric resonance. The investigated phenomena can improve the transceiver sensitivity, bandwidth, providing lower drive voltage, and smaller and lighter weight ultrasonic transducers. Based on the piezocomposites with thickness’ 1…1.5 mm (rod resonance near 2…3 MHz), pillar width 0.2…0.8 mm, kerf width 0.1…0.4 mm, the transceivers with an operating frequency from 140 kHz to 650 kHz were designed and fabricated with a conventional backing of a mixture of high-density tungsten powder and epoxy, and a matching layer of a mixture of low-density glass bubbles and epoxy. Experimental evaluation of their acoustical performance showed expected characteristics suitable for practical applications.
ARTICLE | doi:10.20944/preprints202310.0770.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Surgical navigation; maxillofacial surgey; Tracked instruments; Tracked tools; coronoid hyperplasia; Orbital reconstruction; Virtual surgical simulation; Piezoelectric surgery; Virtual surgery; computer-assisted surgey; simulated guided surgery
Online: 12 October 2023 (05:31:15 CEST)
Surgical navigation has evolved as a vital tool in maxillofacial surgery, offering precise and patient-specific data. This study explores the clinical applications and accuracy of intraoperative tool tracking in maxillofacial surgery. The research includes 37 patients with various pathologies who underwent surgery assisted by a surgical navigation system using tracked instruments. The study showcases two representative cases: one involving coronoid hyperplasia with mouth opening deficit and another addressing nose-orbital-ethmoidal-frontal ossifying fibroma resection. The results indicate that surgical navigation with tracked instruments provides high precision (<1.5 mm error), reduced surgical time, and less invasive approaches. The study highlights the potential for reproducible outcomes and increased safety, especially in complex cases. Despite some limitations, the synergy between surgical navigation and tracked instruments offers a promising approach in maxillofacial surgery, expanding its applications beyond current practices.
ARTICLE | doi:10.20944/preprints201701.0062.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: piezoelectric cantilever energy harvester 1; autonomous 2; adaptive 3; self-powered 4; voltage doubler interface circuit 5; closed loop control 6; feed-forward 7; multi-shot technology 8
Online: 12 January 2017 (10:45:23 CET)
The abundant mechanical vibration energy in bridge road environment can be converted into electric energy by using the piezoelectric energy harvest technology, which could be an efficient way to provide energy required by the wireless sensor network in the bridge condition monitoring system. An autonomous energy harvesting system has been designed based on cantilever beams for sensing and acquiring the bridge vibration energy. After the analysis of the dynamic properties of the piezoelectric cantilever beam in the energy conversion, three kinds of interface circuits were compared through simulation and experimental results. It was shown that the VD interface circuit has less power loss. Furthermore, the proposed closed loop control method based on the VD circuit was simple, adaptive, and self-powered, which is suitable for the road energy harvesting application. Finally, the energy harvesting system based on VD circuit was realized with harvested power of around 0.8mW.
REVIEW | doi:10.20944/preprints202103.0347.v2
Subject: Engineering, Automotive Engineering Keywords: structural health monitoring (SHM); acoustic emission, guided waves, Lamb waves, sensors, ultrasound, piezoelectric, composites, piezopolymers, PVDF, interdigital transducer (IDT), PWAS, C-MUT, CMUT, mems, analog electronic front end; analog signal processing, impact localization, impact detection, sensor node, wireless sensor networks (WSN), IoT, aerospace, automotive, infrastructure, condition monitoring.
Online: 7 April 2021 (17:03:14 CEST)
This review article is focused on the analysis of the state of the art of sensors for guided 9 ultrasonic waves for the detection and localization of impacts, therefore of interest for the structural 10 health monitoring (SHM). The recent developments in sensor technologies are then reported and 11 discussed through the many references in recent scientific literature. The physical phenomena re-12 lated to impact event and the main physical quantities are then introduced to discuss their im-13 portance in the development of the hardware and software components for SHM systems. An im-14 portant aspect of the article is the description of the different ultrasonic sensor technologies cur-15 rently present in the literature and what advantages and disadvantages they could bring, in relation 16 to the various phenomena investigated. In this context, the analysis of the front-end electronics is 17 deepened, the type of data transmission both in terms of wired and wireless technology and in terms 18 of online and offline signal processing. The integration aspects of sensors for the creation of net-19 works with autonomous nodes with the possibility of powering through energy harvesting devices 20 and the embedded processing capacity is also studied. Finally, the emerging sector of processing 21 techniques using deep learning and artificial intelligence concludes the review by indicating the 22 potential for the detection and autonomous characterization of the impacts.