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A Novel Fabry-P??rot Optical Sensor for Guided Wave Signal Acquisition
摘要： In this paper, a novel hybrid damage detection system is proposed, which utilizes piezoelectric actuators for guided wave excitation and a new ?bre optic (FO) sensor based on Fabry-Perot (FP) and Fiber Bragg Grating (FBG). By replacing the FBG sensors with FBG-based FP sensors in the hybrid damage detection system, a higher strain resolution is achieved, which results in higher damage sensitivity and higher reliability in diagnosis. To develop the novel sensor, optimum parameters such as re?ectivity, a wavelength spectrum, and a sensor length were chosen carefully through an analytical model of the sensor, which has been validated with experiments. The sensitivity of the new FBG-based FP sensors was compared to FBG sensors to emphasize the superiority of the new sensors in measuring micro-strains. Lastly, the new FBG-based FP sensor was utilized for recording guided waves in a hybrid setup and compared to the conventional FBG hybrid sensor network to demonstrate their improved performance for a structural health monitoring (SHM) application.
关键词： ?ber optic sensors,guided waves,structural,health monitoring,hybrid PZT-FBG,Fabry-Perot
更新于2025-09-23 15:19:57
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Optimization of pyroelectric conversion of thermal energy through the PZT ceramic buzzer and natural convection
摘要： The main purpose of this work is to take advantage of the pyroelectric e?ect to produce electricity. We propose the use of the PZT ceramic buzzer, which possesses pyroelectric properties, to convert thermal energy into electrical energy by pyroelectric e?ect. We take advantage of natural convection to create temperature variation from a ?xed thermal source. The amount of power harvested by this technique is su?cient to supply low-power systems. Our experiment consists in subjecting the PZT ceramic buzzer to a temperature variation insured only by natural convection created in an oil bath. In order to verify the existence of thermal ?uctuations and con?rm the e?ciency of our technique, we use thermal imaging which shows that the temperature changes as a function of time. We propose in this paper an optimization of our energy-harvesting system by studying the e?ect of the convection system geometry on the pyroelectric response: the e?ect of volume on the pyroelectric response and the e?ect of the distance between the oil surface and the pyroelectric ceramic. It appears from our study that the harvested power increases when the distance between the buzzer and the ?uid decreases but it increases slightly with the volume of liquid.
关键词： pyroelectric effect,energy harvesting,thermal energy,PZT ceramic buzzer,natural convection
更新于2025-09-23 15:19:57
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[IEEE 2018 IEEE SENSORS - New Delhi, India (2018.10.28-2018.10.31)] 2018 IEEE SENSORS - Design and Fabrication of a Piezoelectric Micromachined Ultrasonic Transducer Array Based on Ceramic PZT
摘要： This paper presents a piezoelectric micromachined ultrasonic transducer (pMUT) array fabricated using high-piezoelectric-coefficient ceramic PZT wafers. A new process for polishing ceramic PZT layers down to 5 μm has been developed and applied for manufacturing high-sensitivity pMUTs. A 2 MHz working pMUT array (8×8 elements) based on ceramic PZT has been designed, modeled, fabricated and characterized.
关键词： pMUT,piezoelectric transducers,ultrasonic,micromachined transducers,ceramic PZT
更新于2025-09-19 17:15:36
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The effect of imprint on remanent piezoelectric properties and ferroelectric aging of PbZr <sub/>0.52</sub> Ti <sub/>0.48</sub> O <sub/>3</sub> thin films
摘要： Ferroelectric films suffer from both aging and degradation under high ac-field drive conditions due to loss of polarization with time. In this study, the roles of defect chemistry and internal electric fields on the long-term stability of the properties of piezoelectric films were explored. For this purpose, lead zirconate titanate (PZT) films with a Zr/Ti ratio of 52/48 doped with Mn- (PMZT) or Nb- (PNZT) were deposited on Pt coated Si substrates by the sol-gel method. It was demonstrated that the magnitude of the internal field is much higher in PMZT films compared to PNZT films after poling in the temperature range of 25-200°C under an electric field of -240 kV/cm. The development of the internal field is thermally activated, with activation energies from 0.5±0.06 to 0.8±0.1 eV in Mn doped films and from 0.8±0.1 to 1.2±0.2 eV in Nb doped films. The different activation energies for imprint suggests that the physical mechanism underlying the evolution of the internal field in PMZT and PNZT films differs; the enhanced internal field upon poling is attributed to (1) alignment of oxygen vacancy – acceptor ion defect dipoles (((Mn''_Ti - V_O^{??})_x, (Mn'_Ti - V_O^{??})') in PMZT films, and (2) thermionic injection of electron charges and charge trapping in PNZT films. In either case, the internal field reduces back switching, enhances the remanent piezoelectric properties, and dramatically improves the aging behavior. PMZT films exhibited the greatest enhancement, with reduced high temperature (180°C) aging rates of 2-3%/decade due to improved stability of the poled state. In contrast, PNZT films showed significantly larger high temperature aging rates (15.5%/decade) in the piezoelectric coefficient, demonstrating that the fully poled state was not retained with time.
关键词： aging,PZT,sol-gel,thin film,donor,acceptor,imprint
更新于2025-09-19 17:15:36
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Tunable Low Power Piezo-Plasmonic Random Laser under External Voltage
摘要： This study was aimed to introduce a new kind of low power and tunable random lasers based on piezo-plasmonic core/shell nanoparticles (NPs) consisting of lead zirconate titanate and gold, mixed by different concentrations of Rhodamine B (RhB) dye. To get the random lasing, the sample was exposed to pulsed laser at the presence and in the absence of an external voltage. We got a gradual increase in the thermo-plasmonic emission intensity was enhanced by decreasing the threshold lasing due to an increase in scattering, which more easily made a close loop path in the gain medium. Our results showed some spikes with the same pump energy in emission spectrum which confirmed the coherence random lasing. This phenomenon could be observed in PZT@Au NPs and it could not be observed in Au@PZT NPs in low and high concentrations. properties by increasing the applied voltage on core/shell NPs, which depended on the boundary conditions between the shell and the core samples. By external voltage, the Furthermore, in lower pump energy, we observed low peak intensity in the emission spectrum and it increased as the pump energy overrode the lasing threshold. The emission spectrum became narrow with a sharp increase in the emission intensity, which we could reach a rapid decrease in the full width at half maximum (FWHM) of the emission intensity above the threshold. These results showed the possibility of using these new kinds of materials for low threshold and controllable random lasing.
关键词： external voltage,thermo-plasmonic,piezo-plamsonic,random laser,Au@PZT,PZT@Au core/shell NPs
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE International Symposium on Applications of Ferroelectrics (ISAF) - Lausanne, Switzerland (2019.7.14-2019.7.19)] 2019 IEEE International Symposium on Applications of Ferroelectrics (ISAF) - Vibrating Piezoelectric Energy Conversion Efficiency of Sol-Gel PZT Films with Various Crystal Orientations on MEMS Buckled Diaphragm Structures
摘要： Vibrating energy conversion efficiency was investigated on piezoelectric transducers fabricated on MEMS buckled diaphragm structures from the viewpoint of crystal orientation of sol-gel derived lead-zirconate-titanate (PZT) films. The crystal orientation dominates in-plane stress and spontaneous polarization direction of the PZT films. The in-plane stress affects the static buckling of the diaphragm where a large convex buckling results in a high mechanical conversion efficiency from the flexural vibration to the in-plain vibration. The polarization direction affects the intrinsic piezoelectric conversion efficiency. The crystal orientation of the sol-gel PZT was controlled through pyrolysis temperature between 250?C and 350?C, resulting in a texture variation from (100)-oriented films to (111)-oriented ones. Highly (111)-oriented films showed large polarizations but small buckling deflections, while highly (100)-oriented films showed vice versa. Intermediately textured films with 40–45% (111)-orientation index showed the highest conversion efficiency.
关键词： Piezoelectric,Sol-gel,Residual stress,Buckling,PZT,Polarization,Energy conversion,Diaphragm
更新于2025-09-19 17:13:59
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A dual-output magnetoelectric gyrator
摘要： A novel dual-output magnetoelectric (ME) gyrator operating in an acoustic resonance mode and based on a Pb(ZrxTi1-x)O3 (PZT)/Metglas/PZT (P-M-P) trilayer structure is discussed. The dual-output with different current-to-voltage (I-V) conversion ratios and different voltage levels result from the use of piezoelectric layers with different thicknesses as the output ports. Under open circuit conditions, the maximum I-V conversion ratios of the two outputs were 5.7 and 13.5 kV/A at a frequency of 50.4 kHz. A high power efficiency (?) of 91.7% was achieved and remained relatively stable (≥86%) under increasing power drive to a power density of 45 W/in3. These excellent power transfer and multi-output characteristics offer unique possibilities for possible use of ME gyrators in modern power electronic devices.
关键词： acoustic resonance,dual-output,magnetoelectric gyrator,PZT/Metglas/PZT,power transfer
更新于2025-09-10 09:29:36
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AIP Conference Proceedings [AIP Publishing LLC 41ST ANNUAL REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION: Volume 34 - Boise, Idaho (20–25 July 2014)] - Feasibility of PZT ceramics for impact damage detection in composite structures
摘要： Fiber reinforced plastic composites are becoming widely used in vehicles and airframe structures due to their high strength to weight ratio. However unlike metals, the multilayered composite structures are more susceptible to damage mechanisms such as disbonds and delaminations due to impacts. It is often dif?cult to visually detect the damage. Lead-Zirconate-Titanate (PZT) thin ?lms are becoming popular for in-situ structural health monitoring due to their small size, high piezoelectric coupling coef?cient, and ease of surface-mounting and/or embedding in composite structures. A network of such transducers could be utilized for damage detection using guided wave techniques, impedance techniques, or passive impact detection techniques. However, the PZT ?lms are subject to the same impact probabilities that the structure encounters. If the transducers fail due to the subjected impacts, they can result in false readings and ultimately failing to correctly detect damage in the structure. This paper presents a feasibility study using the guided wave S0 mode for detecting impact damage. The health of the structure is quanti?ed using guided wave measurements, and the PZT health is monitored using impedance methods.
关键词： impact damage detection,impedance techniques,PZT ceramics,composite structures,guided wave techniques
更新于2025-09-10 09:29:36
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Roll-to-Roll (R2R) Production of Ultrasensitive, Flexible, and Transparent Pressure Sensors Based on Vertically Aligned Lead Zirconate Titanate and Graphene Nanoplatelets
摘要： Despite extensive advances in the use of piezoelectric materials in flexible electronics, they have numerous shortcomings, including low efficiency, limited flexibility, and lack of transparency. Additionally, the production of these materials is often limited to small batch processes which are difficult to scale up for mass production. A novel method to produce ultrasensitive, high performance, flexible, and transparent piezoelectric materials where both lead zirconate titanate nanoparticles, and graphene nanoplatelets are aligned together in polydimethylsiloxane under an AC electric field in the thickness (“Z”) direction, is reported here for the first time. The electric field alignment improves the piezoelectric response along with transparency and also reduces the amount of filler required to achieve outstanding piezoelectric properties. The resulting ultrasensitive piezoelectric film is able to sense the pressure of a bird feather (1.4 mg) dropped from a certain distance, whereas at the touch of a fingertip, it can generate up to 8.2 V signal. Moreover, the mass production compatibility of the system is also demonstrated by producing a 3 m long and 15 cm wide large-area sample via a novel 44′ long roll-to-roll manufacturing line which is designed and developed by the group.
关键词： piezoelectric pressure sensor,flexible and transparent sensors,electric field–induced alignment,roll-to-roll manufacturing,PZT and graphene nanoplatelets
更新于2025-09-10 09:29:36
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Finite Element Modellingand Simulations of Piezoelectric Actuators Responses with Uncertainty Quantification
摘要： Piezoelectric structures are widely used in engineering designs including sensors, actuators, and energy-harvesting devices. In this paper, we present the development of a three-dimensional finite element model for simulations of piezoelectric actuators and quantification of their responses under uncertain parameter inputs. The implementation of the finite element model is based on standard nodal approach extended for piezoelectric materials using three-dimensional tetrahedral and hexahedral elements. To account for electrical-mechanical coupling in piezoelectric materials, an additional degree of freedom for electrical potential is added to each node in those elements together with their usual mechanical displacement unknowns. The development was validated with analytical and experimental data for a range of problems from a single-layer piezoelectric beam to multiple layer beams in unimorph and bimorph arrangement. A more detailed analysis is conducted for a unimorph composite plate actuator with different design parameters. Uncertainty quantification was also performed to evaluate the sensitivity of the responses of the piezoelectric composite plate with an uncertain input of material properties. This sheds light on understanding the variations in reported responses of the device; at the same time, providing extra confidence to the numerical model.
关键词： finite element method,uncertainty quantification,piezoelectric materials,unimorph actuator,energy harvesting,PZT
更新于2025-09-10 09:29:36