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Sample records for 1-3 piezoelectric composite

  1. Super-Cell Piezoelectric Composite with 1-3 Connectivity.

    PubMed

    Rouffaud, Remi; Levassort, Franck; Phamti, Mai; Bantignies, Claire; Lethiecq, Marc; Hladky-Hennion, Anne-Christine

    2016-09-05

    The standard fabrication method for 1-3 piezocomposites for ultrasound transducers is the « dice and fill » method (DFM) in which lateral periodicity is introduced. This contributes to the appearance of spurious modes which can drastically affect the performance of the device if they appear near its thickness mode frequency, thus limiting the effective frequency range. A new 1-3 piezocomposite fabricated with a super-cell structure (13SC) was designed in order to overcome these limitations. It consists of the merging of several periodic cells with 47% PZT volume fraction and epoxy resin as the matrix. Two lateral periodicities in one direction are defined as well as two different kerfs. The chosen cell shape is composed of five non-aligned square section rods (11mm2). For comparison of performance, two regular 1-3 piezocomposites (same materials and equivalent periodicities) were fabricated by DFM. Electro-acoustic responses in water were measured for the three composites being considered as transducers. Successive regular thinnings (from 2.8 to 1.1 mm) were carried out for each sample to increase the operating frequency (from around 0.4 to 1.3 MHz) and study the evolution of the characteristics (bandwidth and sensitivity). Experimental results confirmed the behavior of those obtained with numerical simulations, showing that the 13SC composite can be used in this entire frequency range, unlike regular composites.

  2. Smart damping of laminated fuzzy fiber reinforced composite shells using 1-3 piezoelectric composites

    NASA Astrophysics Data System (ADS)

    Kundalwal, S. I.; Kumar, R. Suresh; Ray, M. C.

    2013-10-01

    This paper deals with the investigation of active constrained layer damping (ACLD) of smart laminated continuous fuzzy fiber reinforced composite (FFRC) shells. The distinct constructional feature of a novel FFRC is that the uniformly spaced short carbon nanotubes (CNTs) are radially grown on the circumferential surfaces of the continuous carbon fiber reinforcements. The constraining layer of the ACLD treatment is considered to be made of vertically/obliquely reinforced 1-3 piezoelectric composite materials. A finite element (FE) model is developed for the laminated FFRC shells integrated with the two patches of the ACLD treatment to investigate the damping characteristics of the laminated FFRC shells. The effect of variation of the orientation angle of the piezoelectric fibers on the damping characteristics of the laminated FFRC shells has been studied when the piezoelectric fibers are coplanar with either of the two mutually orthogonal vertical planes of the piezoelectric composite layer. It is revealed that radial growth of CNTs on the circumferential surfaces of the carbon fibers enhances the attenuation of the amplitude of vibrations and the natural frequencies of the laminated FFRC shells over those of laminated base composite shells without CNTs.

  3. Tunable phononic crystals based on piezoelectric composites with 1-3 connectivity.

    PubMed

    Croënne, Charles; Ponge, Marie-Fraise; Dubus, Bertrand; Granger, Christian; Haumesser, Lionel; Levassort, Franck; Vasseur, Jérôme O; Lordereau, Albert; Pham Thi, Mai; Hladky-Hennion, Anne-Christine

    2016-06-01

    Phononic crystals made of piezoelectric composites with 1-3 connectivity are studied theoretically and experimentally. It is shown that they present Bragg band gaps that depend on the periodic electrical boundary conditions. These structures have improved properties compared to phononic crystals composed of bulk piezoelectric elements, especially the existence of larger band gaps and the fact that they do not require severe constraints on their aspect ratios. Experimental results present an overall agreement with the theoretical predictions and clearly show that the pass bands and stop bands of the device under study are easily tunable by only changing the electrical boundary conditions applied on each piezocomposite layer.

  4. The effect of polymeric filler on poling behavior and thermal stability of 1-3 piezoelectric composites

    NASA Astrophysics Data System (ADS)

    Wang, Chunying; Zhang, Rui; Jing, Yujia; Cao, Wenwu

    2016-01-01

    In this paper, the influence of polymeric filler with different glass transition temperature (T g) on the poling behavior and thermal stability of 1-3 piezoelectric composites were investigated, with emphasis on the relationship between T g and temperature dependent properties. The results revealed that high poling temperature improves the piezoelectric coefficient by nearly 12% for composites filled with epoxy (Epotek301, T g above room temperature). On the contrary, high temperature gives a negative impact on the poling of composites filled with rubber (Ke45W, T g below room temperature). In addition, it was found that rubber-filled composites possess better temperature stability between room temperature to140 °C, including dielectric and electromechanical properties, compared with epoxy-filled composites.

  5. Lead-free BNBT-6 piezoelectric ceramic fibre/epoxy 1-3 composites for ultrasonic transducer applications

    NASA Astrophysics Data System (ADS)

    Wang, D. Y.; Li, K.; Chan, H. L. W.

    2005-04-01

    Barium-modified bismuth sodium titanate, 0.94 ×(Bi0.5Na0.5)TiO3-0.06BaTiO3 (BNBT-6), fine-scale piezoelectric fibres were fabricated using a viscous suspension spinning process (VSSP). The sintered BNBT-6 fibres with diameters of ˜300 μm were fabricated into 1-3 composites with fibre volume fraction vf of 0.2-0.5. Piezoelectric and dielectric properties of the 1-3 composites were measured. The electromechanical coupling coefficient kt of a vf=0.40 composite is 0.52. Properties of the VSSP fibres were calculated using the measured properties of the 1-3 composites. A vf=0.40 composite was thinned down to ˜213-μm thickness and constructed into an ultrasonic transducer. The pulse-echo response, bandwidth and insertion loss of the transducers were studied. The VSSP fibre composite transducer with vf=0.40 has a centre frequency of ˜7 MHz with a bandwidth of 88%. The good performance indicated that the BNBT-6/epoxy 1-3 fibre composite transducer has potential for medical imaging applications.

  6. Smart damping of geometrically nonlinear vibrations of laminated composite beams using vertically reinforced 1-3 piezoelectric composites

    NASA Astrophysics Data System (ADS)

    Sarangi, S. K.; Ray, M. C.

    2010-07-01

    This paper deals with the analysis of active constrained layer damping (ACLD) of geometrically nonlinear transient vibrations of laminated composite beams using vertically reinforced 1-3 piezoelectric composite material as the material of the constraining layer of the ACLD treatment. A nonlinear finite element model has been developed for analyzing the ACLD of laminated symmetric and antisymmetric cross-ply and angle-ply composite beams integrated with such ACLD treatment. The von Kármán-type nonlinear strain-displacement relations and the first-order shear deformation theory are used for deriving this coupled electromechanical nonlinear finite element model. The Golla-Hughes-McTavish (GHM) method has been used to model the constrained viscoelastic layer of the ACLD treatment in the time domain. The backbone curves of such a class of nonlinear systems are plotted to determine the excitation levels for causing geometrical nonlinearity. The numerical results reveal that the ACLD treatment significantly improves the damping characteristics of the cross-ply and antisymmetric angle-ply beams for suppressing the geometrically nonlinear transient vibrations of the beams.

  7. Design of low-loss 1-3 piezoelectric composites for high-power transducer applications.

    PubMed

    Lee, Hyeong Jae; Zhang, Shujun

    2012-09-01

    Lead zirconate titanate (PZT)/polymer 1-3 composites have improved electromechanical properties compared with monolithic counterparts, but possess a low mechanical quality factor, limiting their use in high-power transducer applications. The goal of this work was to improve the mechanical quality factor of 1-3 PZT/polymer composites by optimizing the polymer materials. Theoretical analysis and modeling were performed for optimum composite design and various polymers were prepared and characterized. 1-3 piezocomposites were constructed and their electromechanical properties were experimentally determined. The results demonstrated that the composites with high-thermal-conductivity polymers generally have degraded electromechanical properties with significantly decreased mechanical quality factors, whereas the composites filled with low-loss and low-moduli polymers were found to have higher mechanical quality factors with higher electromechanical coupling factors: Q(m) ~ 200 and k(t) ~ 0.68 for PZT4 composites; Q(m) ~ 400 and k(t) ~ 0.6 for PZT8 composites. The improved mechanical quality factor of 1-3 piezocomposites may offer improved performance and thermal stability of transducers under high-drive operation.

  8. Compositional dependence of Pb(Mg1/3,Nb2/3)O3-PbTiO3 piezoelectric thin films by combinatorial sputtering

    NASA Astrophysics Data System (ADS)

    Kurokawa, Fumiya; Tsujiura, Yuichi; Hida, Hirotaka; Kanno, Isaku

    2014-09-01

    We evaluated the compositional dependence of Pb(Mg1/3,Nb2/3)O3-PbTiO3 (PMN-PT) polycrystalline thin films by combinatorial sputtering. We prepared compositional gradient (1 - x)PMN-xPT polycrystalline thin films with preferential orientation along the <001> direction in the composition range of x = 0-0.62. We determined that the morphotropic phase boundary (MPB) composition of PMN-PT polycrystalline thin film existed at around x = 0.35, from the X-ray diffraction (XRD) measurements. The maximum value of relative dielectric constants (ɛr = 1498) was obtained at approximately x = 0.23. On the other hand, the piezoelectric coefficients (|e31,f| = 14.1 C/m2) peaked at the determined MPB composition of x = 0.35. From the results of the compositional dependence of dielectric and piezoelectric characteristics, the FOM (e_{31,\\text{f}}^{2}/\\varepsilon _{0}\\varepsilon _{\\text{r}}) of the PMN-PT (x = 0.35) thin film reached 21 GPa, which is much higher than that of the other polycrystalline piezoelectric thin films. These results suggest that PMN-PT (x = 0.35) thin film is a promising material for high-efficiency piezoelectric MEMS energy harvesters.

  9. Characterization of PMN-PT piezoelectric single crystal and PMN-PT 1-3 composite at elevated temperatures by electrical impedance resonance analysis.

    PubMed

    Wu, Zhengbin; Xi, Kui

    2014-07-01

    In this paper, lead magnesium niobate-lead titanate (PMN-PT) piezoelectric single crystal and its 1-3 composite counterpart were characterized and analyzed under different stable temperatures using both a Simulated Annealing (SA) optimization algorithm and the commercial software PRAP (Piezoelectric Resonance Analysis Program). Electrical impedance resonance characteristics of the two material samples over the range 25-125 °C were measured. The correlation between experimental data and numerical fits derived from both SA and PRAP is considered. Calculation of the determination coefficient (R1(2)) between numerically fitted and measured results is above 95% for both methods. Furthermore, variations in the number of data values used for the fit introduced no more than 3.1% uncertainty on the calculated material parameters. It is found that the complex material parameters of PMN-PT composite are more dependent on temperature than the single crystal. The phase transition of the PMN-PT, which is close to 90 °C, has an effect on the high temperature material characteristics of both piezoelectric materials. These calculated complex material parameters can be used for the design of ultrasonic transducers for elevated temperature applications.

  10. Broadband and high sensitive time-of-flight diffraction ultrasonic transducers based on PMNT/epoxy 1-3 piezoelectric composite.

    PubMed

    Liu, Dongxu; Yue, Qingwen; Deng, Ji; Lin, Di; Li, Xiaobing; Di, Wenning; Wang, Xi'an; Zhao, Xiangyong; Luo, Haosu

    2015-03-19

    5-6 MHz PMNT/epoxy 1-3 composites were prepared by a modified dice-and-fill method. They exhibit excellent properties for ultrasonic transducer applications, such as ultrahigh thickness electromechanical coupling coefficient k(t) (85.7%), large piezoelectric coefficient d33 (1209 pC/N), and relatively low acoustic impedance Z (1.82 × 107 kg/(m2·s)). Besides, two types of Time-of-Flight Diffraction (TOFD) ultrasonic transducers have been designed, fabricated, and characterized, which have different matching layer schemes with the acoustic impedance of 4.8 and 5.7 × 106 kg/(m2·s), respectively. In the detection on a backwall of 12.7 mm polystyrene, the former exhibits higher detectivity, the relative pulse-echo sensitivity and -6 dB relative bandwidth are -21.93 dB and 102.7%, respectively, while the later exhibits broader bandwidth, the relative pulse-echo sensitivity and -6 dB relative bandwidth are -24.08 dB and 117.3%, respectively. These TOFD ultrasonic transducers based on PMNT/epoxy 1-3 composite exhibit considerably improved performance over the commercial PZT/epoxy 1-3 composite TOFD ultrasonic transducer.

  11. Study on dielectric and piezoelectric properties of 0.7 Pb(Mg1/3Nb2/3)O3-0.3 PbTiO3 single crystal with nano-patterned composite electrode

    NASA Astrophysics Data System (ADS)

    Chang, Wei-Yi; Huang, Wenbin; Bagal, Abhijeet; Chang, Chih-Hao; Tian, Jian; Han, Pengdi; Jiang, Xiaoning

    2013-09-01

    Effect of nano-patterned composite electrode and backswitching poling technique on dielectric and piezoelectric properties of 0.7 Pb(Mg1/3Nb2/3)O3-0.3 PbTiO3 was studied in this paper. Composite electrode consists of Mn nano-patterns with pitch size of 200 nm, and a blanket layer of Ti/Au was fabricated using a nanolithography based lift-off process, heat treatment, and metal film sputtering. Composite electrode and backswitching poling resulted in 27% increase of d33 and 25% increase of dielectric constant, and we believe that this is attributed to regularly defined nano-domains and irreversible rhombohedral to monoclinic phase transition in crystal. The results indicate that nano-patterned composite electrode and backswitching poling has a great potential in domain engineering of relaxor single crystals for advanced devices.

  12. Study on dielectric and piezoelectric properties of 0.7 Pb(Mg1/3Nb2/3)O3-0.3 PbTiO3 single crystal with nano-patterned composite electrode.

    PubMed

    Chang, Wei-Yi; Huang, Wenbin; Bagal, Abhijeet; Chang, Chih-Hao; Tian, Jian; Han, Pengdi; Jiang, Xiaoning

    2013-09-21

    Effect of nano-patterned composite electrode and backswitching poling technique on dielectric and piezoelectric properties of 0.7 Pb(Mg1/3Nb2/3)O3-0.3 PbTiO3 was studied in this paper. Composite electrode consists of Mn nano-patterns with pitch size of 200 nm, and a blanket layer of Ti/Au was fabricated using a nanolithography based lift-off process, heat treatment, and metal film sputtering. Composite electrode and backswitching poling resulted in 27% increase of d33 and 25% increase of dielectric constant, and we believe that this is attributed to regularly defined nano-domains and irreversible rhombohedral to monoclinic phase transition in crystal. The results indicate that nano-patterned composite electrode and backswitching poling has a great potential in domain engineering of relaxor single crystals for advanced devices.

  13. Cylindrical Piezoelectric Fiber Composite Actuators

    NASA Technical Reports Server (NTRS)

    Allison, Sidney G.; Shams, Qamar A.; Fox, Robert L.

    2008-01-01

    The use of piezoelectric devices has become widespread since Pierre and Jacques Curie discovered the piezoelectric effect in 1880. Examples of current applications of piezoelectric devices include ultrasonic transducers, micro-positioning devices, buzzers, strain sensors, and clocks. The invention of such lightweight, relatively inexpensive piezoceramic-fiber-composite actuators as macro fiber composite (MFC) actuators has made it possible to obtain strains and displacements greater than those that could be generated by prior actuators based on monolithic piezoceramic sheet materials. MFC actuators are flat, flexible actuators designed for bonding to structures to apply or detect strains. Bonding multiple layers of MFC actuators together could increase force capability, but not strain or displacement capability. Cylindrical piezoelectric fiber composite (CPFC) actuators have been invented as alternatives to MFC actuators for applications in which greater forces and/or strains or displacements may be required. In essence, a CPFC actuator is an MFC or other piezoceramic fiber composite actuator fabricated in a cylindrical instead of its conventional flat shape. Cylindrical is used here in the general sense, encompassing shapes that can have circular, elliptical, rectangular or other cross-sectional shapes in the planes perpendicular to their longitudinal axes.

  14. Simulation-based conceptual design of an acoustic metamaterial with full band gap using an air-based 1-3 piezoelectric composite for ultrasonic noise control

    NASA Astrophysics Data System (ADS)

    Rezaei, Shahrokh; Eskandari-Ghadi, Morteza; Rahimian, Mohammad

    2017-02-01

    This paper aims at proposing a novel type of acoustic metamaterials with complete band gap composed of piezoelectric rods with square array as inclusions embedded in an air background (matrix). A modified plane wave expansion method accompanied with the principles of the Bloch-Floquet method with electromechanical coupling effect and also impedance spectra are used to get a band frequency and to investigate the passband for the selected cut of piezoelectric rods. We investigate both the electromechanical coupling coefficient and mechanical quality factor and their dependency to passband and bandwidth, which depends on both the density and the wave impedance of the matrix and the inclusions (rods). The ratio of the volume of inclusion to the matrix is used to define the fill factor or the so-called inclusion ratio, to introduce the bandwidth as a function of that. Furthermore, the fabrication method is presented in this paper. The results make a suitable foundation for design purposes and may develop an inherently passive ultrasonic noise control. In addition, the results provide the required guidance for a simulation-based design of elastic wave filters or wave guide that might be useful in high-precision mechanical systems operated in certain frequency ranges and switches made of piezoelectric materials; they also propose a novel type of elastic metamaterials, which is independent of the wave direction and has an equal sensitivity in all directions in which it reacts omnidirectionally and mitigates the occupational noise exposure.

  15. High piezoelectric properties of cement piezoelectric composites containing kaolin

    NASA Astrophysics Data System (ADS)

    Pan, Huang Hsing; Yang, Ruei-Hao; Cheng, Yu-Chieh

    2015-04-01

    To obtain high piezoelectric properties, PZT/cement composites with kaolin were fabricated and polarized by 1.5kV/mm electric field for 40 min, where lead zirconate titanate (PZT) inclusion with 50% by volume was used. After the polarization, piezoelectric properties of the composite were measured daily till 100 days. Results indicated that relative dielectric constant (ɛr) and piezoelectric strain constant (d33) increase with aging day, and approach to asymptotic values after 70 days. Temperature treatment to the composite is a dominate factor to enhance piezoelectric properties. The d33 and ɛr values of PZT/cement composites treated at the ambient temperature (23℃) were 57pC/N and 275 at the 70th aging day respectively, and then reached 106pC/N and 455 in turn with 150℃ treatment. The composite contains 4% kaolin having the highest value of d33=111pC/N and ɛr=500 at 90 days because the porosity is the less than the others. Cement piezoelectric composites containing kaolin own the higher d33 and ɛr value, compared with the other reported composites with 50% PZT. The porosity, the electromechanical coupling factor and impedance-frequency spectra of the cement piezoelectric composites were also discussed.

  16. Method of Fabricating a Piezoelectric Composite Apparatus

    NASA Technical Reports Server (NTRS)

    Wilkie, W. Keats (Inventor); Bryant, Robert (Inventor); Fox, Robert L. (Inventor); Hellbaum, Richard F. (Inventor); High, James W. (Inventor); Jalink, Antony, Jr. (Inventor); Little, Bruce D. (Inventor); Mirick, Paul H. (Inventor)

    2003-01-01

    A method for fabricating a piezoelectric macro-fiber composite actuator comprises providing a piezoelectric material that has two sides and attaching one side upon an adhesive backing sheet. The method further comprises slicing the piezoelectric material to provide a plurality of piezoelectric fibers in juxtaposition. A conductive film is then adhesively bonded to the other side of the piezoelectric material, and the adhesive backing sheet is removed. The conductive film has first and second conductive patterns formed thereon which are electrically isolated from one another and in electrical contact with the piezoelectric material. The first and second conductive patterns of the conductive film each have a plurality of electrodes to form a pattern of interdigitated electrodes. A second film is then bonded to the other side of the piezoelectric material. The second film may have a pair of conductive patterns similar to the conductive patterns of the first film.

  17. High temperature, high power piezoelectric composite transducers.

    PubMed

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, Stewart

    2014-08-08

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined.

  18. High Temperature, High Power Piezoelectric Composite Transducers

    PubMed Central

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, StewarT.

    2014-01-01

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined. PMID:25111242

  19. The application of 1-3 cement-based piezoelectric transducers in active and passive health monitoring for concrete structures

    NASA Astrophysics Data System (ADS)

    Qin, Lei; Huang, Shifeng; Cheng, Xin; Lu, Youyuan; Li, Zongjin

    2009-09-01

    1-3 cement-based piezoelectric composite has been developed for health monitoring of concrete structures. Transducers made of this type of composite have broadband frequency response. Plain concrete and engineered cement composite (ECC) beams with embedded 1-3 cement-based piezoelectric transducers were prepared and tested. During experiments, the transducers were used to perform active and passive detection of the damage evolution of the beams. In active detection, a damage index based on the average energy of the received waves was proposed and used. In passive detection, acoustic emission (AE) events were recorded and the accumulated AE event number was analyzed with the loading history. Crack localization was also accomplished in the passive monitoring. The results of the two methods demonstrated similar trends in interpreting the damage evolution of the concrete beam. The results were also consistent with each material's characteristics.

  20. Piezoelectric nanoparticle-polymer composite foams.

    PubMed

    McCall, William R; Kim, Kanguk; Heath, Cory; La Pierre, Gina; Sirbuly, Donald J

    2014-11-26

    Piezoelectric polymer composite foams are synthesized using different sugar-templating strategies. By incorporating sugar grains directly into polydimethylsiloxane mixtures containing barium titanate nanoparticles and carbon nanotubes, followed by removal of the sugar after polymer curing, highly compliant materials with excellent piezoelectric properties can be fabricated. Porosities and elasticity are tuned by simply adjusting the sugar/polymer mass ratio which gave an upper bound on the porosity of 73% and a lower bound on the elastic coefficient of 32 kPa. The electrical performance of the foams showed a direct relationship between porosity and the piezoelectric outputs, giving piezoelectric coefficient values of ∼112 pC/N and a power output of ∼18 mW/cm3 under a load of 10 N for the highest porosity samples. These novel materials should find exciting use in a variety of applications including energy scavenging platforms, biosensors, and acoustic actuators.

  1. Constitutive Modeling of Piezoelectric Polymer Composites

    NASA Technical Reports Server (NTRS)

    Odegard, Gregory M.; Gates, Tom (Technical Monitor)

    2003-01-01

    A new modeling approach is proposed for predicting the bulk electromechanical properties of piezoelectric composites. The proposed model offers the same level of convenience as the well-known Mori-Tanaka method. In addition, it is shown to yield predicted properties that are, in most cases, more accurate or equally as accurate as the Mori-Tanaka scheme. In particular, the proposed method is used to determine the electromechanical properties of four piezoelectric polymer composite materials as a function of inclusion volume fraction. The predicted properties are compared to those calculated using the Mori-Tanaka and finite element methods.

  2. Direct Piezoelectricity of Soft Composite Electrospun Fibers

    NASA Astrophysics Data System (ADS)

    Varga, Michael; Morvan, Jason; Diorio, Nick; Buyuktanir, Ebru; Harden, John; West, John; Jakli, Antal

    2013-03-01

    Recently soft fiber mats electrospun from solutions of Barium Titanate (BT) ferroelectric ceramics particles and poly lactic acid (PLA) were found to have large (d33 1nm/V) converse piezoelectric signals offering a myriad of applications ranging from active implants to smart textiles. Here we report direct piezoelectric measurements (electric signals due to mechanical stress) of the BT/PLA composite fiber mats at various BT concentrations. A testing apparatus was designed and constructed solely for these measurements involving AC stresses provided by a speaker in 10Hz-10kHz frequency range. The piezoelectric constant d33 ~1nC/N was found to be in agreement with the prior converse piezoelectric measurements. The largest signals were obtained with 6% BT/PLA composites, probably because the BT particles at higher concentrations could not be dispersed homogeneously. Importantly the direct piezoelectric signal is large enough to power a small LCD by simply pressing a 0.2mm thick 2 cm2 area mat by a finger. We expect to use these mats in active Braille cells and in liquid crystal writing tablets.

  3. Telescoping cylindrical piezoelectric fiber composite actuator assemblies

    NASA Technical Reports Server (NTRS)

    Allison, Sidney G. (Inventor); Shams, Qamar A. (Inventor); Fox, Robert L. (Inventor); Fox, legal representative, Christopher L. (Inventor); Fox Chattin, legal representative, Melanie L. (Inventor)

    2010-01-01

    A telescoping actuator assembly includes a plurality of cylindrical actuators in a concentric arrangement. Each cylindrical actuator is at least one piezoelectric fiber composite actuator having a plurality of piezoelectric fibers extending parallel to one another and to the concentric arrangement's longitudinal axis. Each cylindrical actuator is coupled to concentrically-adjacent ones of the cylindrical actuators such that the plurality of cylindrical actuators can experience telescopic movement. An electrical energy source coupled to the cylindrical actuators applies actuation energy thereto to generate the telescopic movement.

  4. Characterization of Piezoelectric PDMS-Nanoparticle Composites

    NASA Astrophysics Data System (ADS)

    Borsa, C. J.; Mionic Ebersold, M.; Bowen, P.; Farine, P.-A.; Briand, D.

    2015-12-01

    In this work, the novel fabrication and characterization of elastomeric piezoelectric nanocomposites are explored. Fabrication methods explored herein utilize ball milled barium titanate powder dispersions, along with double walled carbon nanotubes which are dispersed in toluene though the use of an ultrasonic probe. Test devices are then constructed with electrodes made from evaporated gold on polyimide foils and protective dielectrics of pristine PDMS. Two different device construction methods are explored utilizing both direct contact bonding and plasma bonding of the active composite layers to the dielectric/electrode. Test samples are evaluated through the use of a dedicated Berlincourt type piezoelectric d33 meter.

  5. Piezoelectric Nanoparticle-Polymer Composite Materials

    NASA Astrophysics Data System (ADS)

    McCall, William Ray

    Herein we demonstrate that efficient piezoelectric nanoparticle-polymer composite materials can be synthesized and fabricated into complex microstructures using sugar-templating methods or optical printing techniques. Stretchable foams with excellent tunable piezoelectric properties are created by incorporating sugar grains directly into polydimethylsiloxane (PDMS) mixtures containing barium titanate (BaTiO3 -- BTO) nanoparticles and carbon nanotubes (CNTs), followed by removal of the sugar after polymer curing. Porosities and elasticity are tuned by simply adjusting the sugar/polymer mass ratio and the electrical performance of the foams showed a direct relationship between porosity and the piezoelectric outputs. User defined 2D and 3D optically printed piezoelectric microstructures are also fabricated by incorporating BTO nanoparticles into photoliable polymer solutions such as polyethylene glycol diacrylate (PEGDA) and exposing to digital optical masks that can be dynamically altered. Mechanical-to-electrical conversion efficiency of the optically printed composite is enhanced by chemically altering the surface of the BTO nanoparticles with acrylate groups which form direct covalent linkages with the polymer matrix under light exposure. Both of these novel materials should find exciting uses in a variety of applications including energy scavenging platforms, nano- and microelectromechanical systems (NEMS/MEMS), sensors, and acoustic actuators.

  6. Composite lateral electric field excited piezoelectric resonator.

    PubMed

    Zaitsev, B D; Shikhabudinov, A M; Borodina, I A; Teplykh, A A; Kuznetsova, I E

    2017-01-01

    The novel method of suppression of parasitic oscillations in lateral electric field excited piezoelectric resonator is suggested. Traditionally such resonator represents the piezoelectric plate with two electrodes on one side of the plate. The crystallographic orientation of the plate is selected so that the tangential components of electric field excite bulk acoustic wave with given polarization travelling along the normal to the plate sides. However at that the normal components of field excite the parasitic Lamb waves and bulk waves of other polarization which deteriorate the resonant properties of the resonator. In this work we suggest to separate the source of the HF electric field and resounded piezoelectric plate by air gap. In this case the tangential components of the field in piezoelectric plate do not practically weaken but normal components significantly decrease. This method is realized on the composite resonator having the structure "glass plate with rectangular electrodes - air gap - plate of 128 Y-X lithium niobate." It has been shown that there exist the optimal value of the width gap which ensure the good quality of series and parallel resonances in frequency range 3-4MHz with record values of Q-factor of ∼15,000 in both cases.

  7. Piezoelectric Polymer/Ceramic Composite

    DTIC Science & Technology

    1989-05-02

    significant. The current in ?iEZEL samole was cbserved to reach steady state level in the region cf -i05 sec whereas in t-he prepared composites the tine talen ... technology is not a’ silable for prodccinc s;ch materials in tOe areas and thicknesses required for commecrcial applications in c:apacitolrs. Y~i5.h~4 ’~ x

  8. Structural integrity of composites with embedded piezoelectric ceramic transducers

    NASA Astrophysics Data System (ADS)

    Paget, Christophe A.; Levin, Klas

    1999-06-01

    The objective of this paper is to determine the strength reduction due to the embedment of a piezoelectric ceramic transducer in a composite. The composite was made from carbon/epoxy prepreg with a cross-ply lay-up. The transducer was embedded in the mid-plane of the composite material. The specimens were tested in tensile and compressive static loading. It was found that the embedded piezoelectric ceramic element with its interconnectors did not reduce the strength of the composite. In tensile and compressive static tests, the final failure did not coincide with the embedded piezoelectric ceramic transducer location in the composite.

  9. Electrospinning of continuous piezoelectric yarns for composite application

    NASA Astrophysics Data System (ADS)

    Lagoudas, Natasha C.; Ounaies, Zoubeida

    2008-03-01

    The focus of this research is to electrospin continuous yarns of piezoelectric nanofibers. Incorporating piezoelectric polymer fibers in traditional composites can add sensing and actuation capabilities, which creates a wide array of potential applications. To process nanofibers with piezoelectric properties, we are pursuing the electrospinning of poly (vinylidene fluoride) (PVDF) in DMAc. A method of electrospinning on water is used to form the continuous fibers, which are then tested using DSC, XRD, and microscopy. Through this technique, we see evidence that the non-polar α-phase of PVDF is converted to the polar β-phase, which is responsible for its piezoelectric behavior.

  10. Design, fabrication, and properties of 2-2 connectivity cement/polymer based piezoelectric composites with varied piezoelectric phase distribution

    SciTech Connect

    Dongyu, Xu; Xin, Cheng; Shifeng, Huang; Banerjee, Sourav

    2014-12-28

    The laminated 2-2 connectivity cement/polymer based piezoelectric composites with varied piezoelectric phase distribution were fabricated by employing Lead Zirconium Titanate ceramic as active phase, and mixture of cement powder, epoxy resin, and hardener as matrix phase with a mass proportion of 4:4:1. The dielectric, piezoelectric, and electromechanical coupling properties of the composites were studied. The composites with large total volume fraction of piezoelectric phase have large piezoelectric strain constant and relative permittivity, and the piezoelectric and dielectric properties of the composites are independent of the dimensional variations of the piezoelectric ceramic layer. The composites with small total volume fraction of piezoelectric phase have large piezoelectric voltage constant, but also large dielectric loss. The composite with gradually increased dimension of piezoelectric ceramic layer has the smallest dielectric loss, and that with the gradually increased dimension of matrix layer has the largest piezoelectric voltage constant. The novel piezoelectric composites show potential applications in fabricating ultrasonic transducers with varied surface vibration amplitude of the transducer.

  11. Design, fabrication, and properties of 2-2 connectivity cement/polymer based piezoelectric composites with varied piezoelectric phase distribution.

    PubMed

    Dongyu, Xu; Xin, Cheng; Banerjee, Sourav; Shifeng, Huang

    2014-12-28

    The laminated 2-2 connectivity cement/polymer based piezoelectric composites with varied piezoelectric phase distribution were fabricated by employing Lead Zirconium Titanate ceramic as active phase, and mixture of cement powder, epoxy resin, and hardener as matrix phase with a mass proportion of 4:4:1. The dielectric, piezoelectric, and electromechanical coupling properties of the composites were studied. The composites with large total volume fraction of piezoelectric phase have large piezoelectric strain constant and relative permittivity, and the piezoelectric and dielectric properties of the composites are independent of the dimensional variations of the piezoelectric ceramic layer. The composites with small total volume fraction of piezoelectric phase have large piezoelectric voltage constant, but also large dielectric loss. The composite with gradually increased dimension of piezoelectric ceramic layer has the smallest dielectric loss, and that with the gradually increased dimension of matrix layer has the largest piezoelectric voltage constant. The novel piezoelectric composites show potential applications in fabricating ultrasonic transducers with varied surface vibration amplitude of the transducer.

  12. Characterization of piezoelectric macrofiber composite actuated winglets

    NASA Astrophysics Data System (ADS)

    Guha, T. K.; Oates, W. S.; Kumar, R.

    2015-06-01

    The present study primarily focuses on the design, development, and structural characterization of an oscillating winglet actuated using a piezoelectric macrofiber composite (MFC). The primary objective is to study the effect of controlled wingtip oscillations on the evolution of wingtip vortices, with a goal of weakening these potentially harmful tip vortices by introducing controlled instabilities through both spatial and temporal perturbations producible through winglet oscillations. MFC-actuated winglets have been characterized under different input excitation and pressure-loading conditions. The winglet oscillations show bimodal behavior for both structural and actuation modes of resonance. The oscillatory amplitude at these actuation modes increases linearly with the magnitude of excitation. During wind-tunnel tests, fluid-structure interactions led to structural vibrations of the wing. The effect of these vibrations on the overall winglet oscillations decreased when the strength of actuation increased. At high input excitation, the actuated winglet was capable of generating controlled oscillations. As a proof of concept, the current study has demonstrated that microfiber composite-actuated winglets produce sufficient displacements to alter the development of the wingtip vortex.

  13. Detection of Delaminations in Composite Beams Using Piezoelectric Sensors

    NASA Technical Reports Server (NTRS)

    Saravanos, Dimitris A.; Birman, Victor; Hopkins, Dale A.

    1994-01-01

    This paper investigates the feasibility of a proposed technique for detecting delamination using piezoelectric layers or patches embedded or bonded to a composite structure. Variations in the voltage generated in the piezoelectric layers indicates the presence and location of delamination, when the structure is excited either externally or via actuators. The theoretical foundations of a method for predicting the dynamic response of delaminated composite beams with piezoelectric layers are described. The governing equations are presented for the case of external vibroacoustic excitation, as well as, for the case of locally induced vibrations by some of the embedded piezoelectric elements. An exact solution is developed within the limits of linear laminate theory. Applications illustrate the feasibility of delamination detection in cantilever beams. The results illustrate that the proposed technique may provide accurate detection of the presence, size, and location of a delamination.

  14. Static aeroelastic behavior of an adaptive laminated piezoelectric composite wing

    NASA Technical Reports Server (NTRS)

    Weisshaar, T. A.; Ehlers, S. M.

    1990-01-01

    The effect of using an adaptive material to modify the static aeroelastic behavior of a uniform wing is examined. The wing structure is idealized as a laminated sandwich structure with piezoelectric layers in the upper and lower skins. A feedback system that senses the wing root loads applies a constant electric field to the piezoelectric actuator. Modification of pure torsional deformaton behavior and pure bending deformation are investigated, as is the case of an anisotropic composite swept wing. The use of piezoelectric actuators to create an adaptive structure is found to alter static aeroelastic behavior in that the proper choice of the feedback gain can increase or decrease the aeroelastic divergence speed. This concept also may be used to actively change the lift effectiveness of a wing. The ability to modify static aeroelastic behavior is limited by physical limitations of the piezoelectric material and the manner in which it is integrated into the parent structure.

  15. High Frequency PMN-PT 1-3 Composite Transducer for Ultrasonic Imaging Application.

    PubMed

    Sun, Ping; Wang, Gaofeng; Wu, Dawei; Zhu, Benpeng; Hu, Changhong; Liu, Changgeng; Djuth, Frank T; Zhou, Qifa; Shung, K Kirk

    2010-01-01

    Development of PMN-PT single crystal/epoxy 1-3 composites for high-frequency ultrasonic transducers application is presented. The composite was fabricated by using a DRIE dry etching process with a 45% volume fraction of PMN-PT. A 35 MHz ultrasound flat transducer was fabricated with the composite, which was found to have an effective electromechanical coupling coefficient of 0.81, an insertion loss of 18 db, and a -6 dB bandwidth as high as 100%. Tungsten wire phantom image shows that the transducer had an axial resolution of 30 μm, which was in good agreement with the theoretical expectation. The initial results showed that the PMN-PT/epoxy 1-3 composite has many attractive properties over conventional piezoelectric materials for medical imaging applications.

  16. Piezoelectric Vibration Damping Study for Rotating Composite Fan Blades

    NASA Technical Reports Server (NTRS)

    Min, James B.; Duffy, Kirsten P.; Choi, Benjamin B.; Provenza, Andrew J.; Kray, Nicholas

    2012-01-01

    Resonant vibrations of aircraft engine blades cause blade fatigue problems in engines, which can lead to thicker and aerodynamically lower performing blade designs, increasing engine weight, fuel burn, and maintenance costs. In order to mitigate undesirable blade vibration levels, active piezoelectric vibration control has been investigated, potentially enabling thinner blade designs for higher performing blades and minimizing blade fatigue problems. While the piezoelectric damping idea has been investigated by other researchers over the years, very little study has been done including rotational effects. The present study attempts to fill this void. The particular objectives of this study were: (a) to develop and analyze a multiphysics piezoelectric finite element composite blade model for harmonic forced vibration response analysis coupled with a tuned RLC circuit for rotating engine blade conditions, (b) to validate a numerical model with experimental test data, and (c) to achieve a cost-effective numerical modeling capability which enables simulation of rotating blades within the NASA Glenn Research Center (GRC) Dynamic Spin Rig Facility. A numerical and experimental study for rotating piezoelectric composite subscale fan blades was performed. It was also proved that the proposed numerical method is feasible and effective when applied to the rotating blade base excitation model. The experimental test and multiphysics finite element modeling technique described in this paper show that piezoelectric vibration damping can significantly reduce vibrations of aircraft engine composite fan blades.

  17. Constructing of cure monitoring system with piezoelectric ceramics for composite laminate

    NASA Astrophysics Data System (ADS)

    Oshima, Nobuo; Inoue, Kouichi; Motogi, Shinya; Fukuda, Takehito

    2003-08-01

    The cure monitoring system with piezoelectric ceramics is constructed. An embedded type piezoelectric ceramics sensor with flat lead wires is developed. And the piezoelectric ceramics is embedded into composite laminate. A dummy piezoelectric ceramics is set in the autoclave oven. The impedance of the piezoelectric ceramics which is embedded in the composite laminate and that of the dummy piezoelectric ceramics are measured by a LCR meter. The piezoelectric ceramics have strong temperature dependency. The temperature dependency of the impedance of piezoelectric ceramics is corrected by the information from the dummy piezoelectric ceramics. A dielectric sensor is also embedded in the composite laminate as a reference sensor for the degree of cure. The change in calculated cure index shows good correspondence with change in the log ion viscosity which is measured by the dielectric cure monitoring sensor.

  18. Magnetostrictive-piezoelectric composite structures for energy harvesting

    NASA Astrophysics Data System (ADS)

    Lafont, Thomas; Gimeno, L.; Delamare, J.; Lebedev, G. A.; Zakharov, D. I.; Viala, B.; Cugat, O.; Galopin, N.; Garbuio, L.; Geoffroy, O.

    2012-09-01

    In this paper, harvesters coupling magnetostrictive and piezoelectric materials are investigated. The energy conversion of quasi-static magnetic field variations into electricity is detailed. Experimental results are exposed for two macroscopic demonstrators based on the rotation of a permanent magnet. These composite/hybrid devices use both piezoelectric and magnetostrictive (amorphous FeSiB ribbon or bulk Terfenol-D) materials. A quasi-static (or ultra-low frequency) harvester is constructed with exploitable output voltage, even in quasi-static mode. Integrated micro-harvesters using sub-micron multilayers of active materials on Si have been built and are currently being characterized.

  19. Direct piezoelectric responses of soft composite fiber mats

    NASA Astrophysics Data System (ADS)

    Varga, M.; Morvan, J.; Diorio, N.; Buyuktanir, E.; Harden, J.; West, J. L.; Jákli, A.

    2013-04-01

    Recently soft fiber mats electrospun from solutions of Barium Titanate (BT) ferroelectric ceramics particles and polylactic acid (PLA) were found to have large (d33 ˜ 1 nm/V) converse piezoelectric signals offering a myriad of applications ranging from active implants to smart textiles. Here, we report direct piezoelectric measurements (electric signals due to mechanical stress) of the BT/PLA composite fiber mats at several BT concentrations. A homemade testing apparatus provided AC stresses in the 50 Hz-1.5 kHz-frequency range. The piezoelectric constant d33 ˜ 0.5 nC/N and the compression modulus Y ˜ 104-105 Pa found are in agreement with the prior converse piezoelectric and compressibility measurements. Importantly, the direct piezoelectric signal is large enough to power a small LCD by simple finger tapping of a 0.15 mm thick 2-cm2 area mat. We propose using these mats in active Braille cells and in liquid crystal writing tablets.

  20. Enhanced converse magnetoelectric effect in cylindrical piezoelectric-magnetostrictive composites

    NASA Astrophysics Data System (ADS)

    Wu, Gaojian; Zhang, Ru; Zhang, Ning

    2016-10-01

    Enhanced converse magnetoelectric (ME) effect has been experimentally observed in cylindrical PZT-Terfenol-D piezoelectric-magnetostrictive bilayered composites, where the piezoelectric and magnetostrictive components are coupled through normal stresses instead of shear stresses that act in most of previous multiferroic composites. A theoretical model based on elastodynamics analysis has been proposed to describe the frequency response of converse ME effect for axial and radial modes in the bilayered cylindrical composites. The theory shows good agreement with the experimental results. The different variation tendency of resonant converse ME coefficient, as well as different variation rate of resonance frequency with bias magnetic field for axial and radial modes is interpreted in terms of demagnetizing effect. This work is of theoretical and technological significance for the application of converse ME effect as magnetic sensor, transducers, coil-free flux switch, etc.

  1. Novel composite piezoelectric material for energy harvesting applications

    NASA Astrophysics Data System (ADS)

    Janusas, Giedrius; Guobiene, Asta; Palevicius, Arvydas; Prosycevas, Igoris; Ponelyte, Sigita; Baltrusaitis, Valentinas; Sakalys, Rokas

    2015-04-01

    Past few decades were concentrated on researches related to effective energy harvesting applied in modern technologies, MEMS or MOEMS systems. There are many methods for harvesting energy as, for example, usage of electromagnetic devices, but most dramatic changes were noticed in the usage of piezoelectric materials in small scale devices. Major limitation faced was too small generated power by piezoelectric materials or high resonant frequencies of such smallscale harvesters. In this research, novel composite piezoelectric material was created by mixing PZT powder with 20% solution of polyvinyl butyral in benzyl alcohol. Obtained paste was screen printed on copper foil using 325 mesh stainless steel screen and dried for 30 min at 100 °C. Polyvinyl butyral ensures good adhesion and flexibility of a new material at the conditions that requires strong binding. Five types of a composite piezoelectric material with different concentrations of PZT (40%, 50%, 60%, 70% and 80 %) were produced. As the results showed, these harvesters were able to transform mechanical strain energy into electric potential and, v.v. In experimental setup, electromagnetic shaker was used to excite energy harvester that is fixed in the custom-built clamp, while generated electric potential were registered with USB oscilloscope PICO 3424. The designed devices generate up to 80 μV at 50 Hz excitation. This property can be applied to power microsystem devices or to use them in portable electronics and wireless sensors. However, the main advantage of the created composite piezoelectric material is possibility to apply it on any uniform or nonuniform vibrating surface and to transform low frequency vibrations into electricity.

  2. Ferroelectric, piezoelectric, and dielectric properties of BiScO{sub 3}-PbTiO{sub 3}-Pb(Cd{sub 1/3}Nb{sub 2/3})O{sub 3} ternary high temperature piezoelectric ceramics

    SciTech Connect

    Zhao Tianlong; Chen Jianguo; Dong Shuxiang; Wang Chunming; Yu Yang

    2013-07-14

    (0.95-x)BiScO{sub 3}-xPbTiO{sub 3}-0.05Pb(Cd{sub 1/3}Nb{sub 2/3})O{sub 3} (BS-xPT-PCN) high temperature piezoelectric ceramics near the morphotropic phase boundary (MPB) have been synthesized by traditional solid-state reaction methods. The microstructural morphology, phase structure, and electrical properties of BS-xPT-PCN ceramics were investigated in detail. X-ray diffraction analysis indicated BS-xPT-PCN ceramics have a pure perovskite structure. The coexistence of rhombohedral and tetragonal phases at MPB composition enhanced the polarizability by the coupling between two dynamically equivalent energy states, resulting in the improved piezoelectric and ferroelectric properties at MPB vicinity. The BS-xPT-PCN (x = 0.60) ceramics possess the optimal piezoelectric and ferroelectric properties with d{sub 33} = 505pC/N, k{sub p} = 55.9%, k{sub t} = 36.5%, strain = 0.23% (under the electric field 37.5 kV/cm), and P{sub r} = 39.7 {mu}C/cm{sup 2}. High temperature dielectric behaviors showed diffuse phase transition in BS-xPT-PCN ceramics. The Curie temperature T{sub c} was found to increase from 371 Degree-Sign C to 414 Degree-Sign C with x increasing from 0.58 to 0.62. All these results together with the good thermal stabilities make the BS-xPT-PCN ceramics promising candidates for high temperature piezoelectric applications.

  3. Dielectric and piezoelectric properties of percolative three-phase piezoelectric polymer composites

    NASA Astrophysics Data System (ADS)

    Sundar, Udhay

    Three-phase piezoelectric bulk composites were fabricated using a mix and cast method. The composites were comprised of lead zirconate titanate (PZT), aluminum (Al) and an epoxy matrix. The volume fraction of the PZT and Al were varied from 0.1 to 0.3 and 0.0 to 0.17, respectively. The influences of three entities on piezoelectric and dielectric properties: inclusion of an electrically conductive filler (Al), poling process (contact and Corona) and Al surface treatment, were observed. The piezoelectric strain coefficient, d33, effective dielectric constant, epsilon r, capacitance, C, and resistivity were measured and compared according to poling process, volume fraction of constituent phases and Al surface treatment. The maximum values of d33 were 3.475 and 1.0 pC/N for Corona and contact poled samples respectively, for samples with volume fractions of 0.40 and 0.13 of PZT and Al (surface treated) respectively. Also, the maximum dielectric constant for the surface treated Al samples was 411 for volume fractions of 0.40 and 0.13 for PZT and Al respectively. The percolation threshold was observed to occur at an Al volume fraction of 0.13. The composites achieved a percolated state for Al volume fractions >0.13 for both contact and corona poled samples. In addition, a comparative time study was conducted to examine the influence of surface treatment processing time of Al particles. The effectiveness of the surface treatment, sample morphology and composition was observed with the aid of SEM and EDS images. These images were correlated with piezoelectric and dielectric properties. PZT-epoxy-aluminum thick films (200 mum) were also fabricated using a two-step spin coat deposition and annealing method. The PZT volume fraction were varied from 0.2, 0.3 and 0.4, wherein the Aluminum volume fraction was varied from 0.1 to 0.17 for each PZT volume fraction, respectively. The two-step process included spin coating the first layer at 500 RPM for 30 seconds, and the second

  4. Study of 1-3 PZT fibre/epoxy composite force sensor

    NASA Astrophysics Data System (ADS)

    Choy, S. H.; Chan, H. L. W.; Ng, M. W.; Liu, P. C. K.

    2005-09-01

    Lead zirconate titanate (PZT) fibres were prepared by a powder-based extrusion method. Pre-sintered PZT powder mixed with poly(acrylic acid) was spun in a spinnerette to produce fibres. The fibre of ˜400 μm diameter was used to fabricate 1-3 PZT fibre/epoxy composite discs with different volume fractions (ϕ) of PZT. Since the ceramic fibres are rather brittle, their elastic properties cannot be measured directly. In order to determine the properties of the ceramic fibres, effective properties of the fibres/epoxy 1-3 composite were measured. By using a modified series and parallel model, the properties of 1-3 composites can be calculated. Then, the elastic coefficient s33,fibreE, relative permittivity ɛ33,fibreT and piezoelectric strain coefficient d33,fibre of the ceramic fibre could be found. Ring-shaped PZT fibre/epoxy materials composites with different ϕ were fabricated to be used as the sensing material in force sensor applications. The ring-shape composite with ϕ=0.5 was installed into a housing and the sensor was calibrated by different methods and its sensitivity was found to be 144 pC/N within the frequency range of 0.5 6.4 kHz which is much higher than that of a quartz force sensor with a similar structure.

  5. Active Piezoelectric Vibration Control of Subscale Composite Fan Blades

    NASA Technical Reports Server (NTRS)

    Duffy, Kirsten P.; Choi, Benjamin B.; Provenza, Andrew J.; Min, James B.; Kray, Nicholas

    2012-01-01

    As part of the Fundamental Aeronautics program, researchers at NASA Glenn Research Center (GRC) are investigating new technologies supporting the development of lighter, quieter, and more efficient fans for turbomachinery applications. High performance fan blades designed to achieve such goals will be subjected to higher levels of aerodynamic excitations which could lead to more serious and complex vibration problems. Piezoelectric materials have been proposed as a means of decreasing engine blade vibration either through a passive damping scheme, or as part of an active vibration control system. For polymer matrix fiber composite blades, the piezoelectric elements could be embedded within the blade material, protecting the brittle piezoceramic material from the airflow and from debris. To investigate this idea, spin testing was performed on two General Electric Aviation (GE) subscale composite fan blades in the NASA GRC Dynamic Spin Rig Facility. The first bending mode (1B) was targeted for vibration control. Because these subscale blades are very thin, the piezoelectric material was surface-mounted on the blades. Three thin piezoelectric patches were applied to each blade two actuator patches and one small sensor patch. These flexible macro-fiber-composite patches were placed in a location of high resonant strain for the 1B mode. The blades were tested up to 5000 rpm, with patches used as sensors, as excitation for the blade, and as part of open- and closed-loop vibration control. Results show that with a single actuator patch, active vibration control causes the damping ratio to increase from a baseline of 0.3% critical damping to about 1.0% damping at 0 RPM. As the rotor speed approaches 5000 RPM, the actively controlled blade damping ratio decreases to about 0.5% damping. This occurs primarily because of centrifugal blade stiffening, and can be observed by the decrease in the generalized electromechanical coupling with rotor speed.

  6. 1-3 connectivity composite material made from lithium niobate and cement for ultrasonic condition monitoring at elevated temperatures.

    PubMed

    Shepherd, G; Cochran, A; Kirk, K J; McNab, A

    2002-05-01

    We have designed, manufactured and tested a piezoelectric composite material to operate at temperatures above 400 degrees C. The material is a 1-3 connectivity composite with pillars of Z-cut lithium niobate in a matrix of alumina cement. The composite material produced shorter pulses than a monolithic plate of lithium niobate and remained intact upon cooling. Results are presented from room temperature and high temperature testing. This material could be bonded permanently to a test object, making it possible to carry out condition monitoring over an extended period. A new excitation method was also developed to enable remote switching between array elements.

  7. Study of BNKLBT-1.5 lead-free ceramic/epoxy 1-3 composites

    SciTech Connect

    Choy, S. H.; Li, W. K.; Li, H. K.; Lam, K. H.; Chan, H. L. W.

    2007-12-01

    Bismuth sodium titanate based lead-free ceramic fiber with the chemical formula of 0.885(Bi{sub 0.5}Na{sub 0.5})TiO{sub 3}-0.05(Bi{sub 0.5}K{sub 0.5})TiO{sub 3}-0.015(Bi{sub 0.5}Li{sub 0.5}= )TiO{sub 3}-0.05BaTiO{sub 3}, BNKLBT-1.5, has been fabricated by a powder-based extrusion method. The ceramic fibers with 400 {mu}m diameter were well crystallized after being calcined at 800 deg. C and sintered at 1170 deg. C. The piezoelectric and ferroelectric properties of the single fiber were found to be 155 pC/N and {approx}34.5 {mu}C/cm{sup 2}, respectively, which is comparable with that in bulk sample. 1-3 ceramic/polymer composites were fabricated by two routes, including dice and filled method and fiber pick-and-place method. Theoretical models were used to calculate the piezoelectric properties of the composites and compared with experimental results.

  8. Study of BNKLBT-1.5 lead-free ceramic/epoxy 1-3 composites

    NASA Astrophysics Data System (ADS)

    Choy, S. H.; Li, W. K.; Li, H. K.; Lam, K. H.; Chan, H. L. W.

    2007-12-01

    Bismuth sodium titanate based lead-free ceramic fiber with the chemical formula of 0.885(Bi0.5Na0.5)TiO3-0.05(Bi0.5K0.5)TiO3-0.015(Bi0.5Li0.5)TiO3-0.05BaTiO3, BNKLBT-1.5, has been fabricated by a powder-based extrusion method. The ceramic fibers with 400μm diameter were well crystallized after being calcined at 800°C and sintered at 1170°C. The piezoelectric and ferroelectric properties of the single fiber were found to be 155pC/N and ˜34.5μC/cm2, respectively, which is comparable with that in bulk sample. 1-3 ceramic/polymer composites were fabricated by two routes, including dice and filled method and fiber pick-and-place method. Theoretical models were used to calculate the piezoelectric properties of the composites and compared with experimental results.

  9. KNN–NTK composite lead-free piezoelectric ceramic

    SciTech Connect

    Matsuoka, T. Kozuka, H.; Kitamura, K.; Yamada, H.; Kurahashi, T.; Yamazaki, M.; Ohbayashi, K.

    2014-10-21

    A (K,Na)NbO₃-based lead-free piezoelectric ceramic was successfully densified. It exhibited an enhanced electromechanical coupling factor of kₚ=0.52, a piezoelectric constant d₃₃=252 pC/N, and a frequency constant Nₚ=3170 Hz m because of the incorporation of an elaborate secondary phase composed primarily of KTiNbO₅. The ceramic's nominal composition was 0.92K₀.₄₂Na₀.₄₄Ca₀.₀₄Li₀.₀₂Nb₀.₈₅O₃–0.047K₀.₈₅Ti₀.₈₅Nb₁.₁₅O₅–0.023BaZrO₃ –0.0017Co₃O₄–0.002Fe₂O₃–0.005ZnO, abbreviated herein as KNN–NTK composite. The KNN–NTK ceramic exhibited a dense microstructure with few microvoids which significantly degraded its piezoelectric properties. Elemental maps recorded using transmission electron microscopy with energy-dispersive X-ray spectroscopy (TEM–EDS) revealed regions of high concentrations of Co and Zn inside the NTK phase. In addition, X-ray diffraction patterns confirmed that a small portion of the NTK phase was converted into K₂(Ti,Nb,Co,Zn)₆O₁₃ or CoZnTiO₄ by a possible reaction between Co and Zn solutes and the NTK phase during a programmed sintering schedule. TEM studies also clarified a distortion around the KNN/NTK interfaces. Such an NTK phase filled voids between KNN particles, resulting in an improved chemical stability of the KNN ceramic. The manufacturing process was subsequently scaled to 100 kg per batch for granulated ceramic powder using a spray-drying technique. The properties of the KNN–NTK composite ceramic produced using the scaled-up method were confirmed to be identical to those of the ceramic prepared by conventional solid-state reaction sintering. Consequently, slight changes in the NTK phase composition and the distortion around the KNN/NTK interfaces affected the KNN–NTK composite ceramic's piezoelectric characteristics.

  10. Coupled mixed-field laminate theory and finite element for smart piezoelectric composite shell structures

    NASA Technical Reports Server (NTRS)

    Saravanos, Dimitris A.

    1996-01-01

    Mechanics for the analysis of laminated composite shells with piezoelectric actuators and sensors are presented. A new mixed-field laminate theory for piezoelectric shells is formulated in curvilinear coordinates which combines single-layer assumptions for the displacements and a layerwise representation for the electric potential. The resultant coupled governing equations for curvilinear piezoelectric laminates are described. Structural mechanics are subsequently developed and an 8-node finite-element is formulated for the static and dynamic analysis of adaptive composite structures of general laminations containing piezoelectric layers. Evaluations of the method and comparisons with reported results are presented for laminated piezoelectric-composite plates, a closed cylindrical shell with a continuous piezoceramic layer and a laminated composite semi-circular cantilever shell with discrete cylindrical piezoelectric actuators and/or sensors.

  11. Mechanical and Vibration Testing of Carbon Fiber Composite Material with Embedded Piezoelectric Sensors

    NASA Technical Reports Server (NTRS)

    Duffy, Kirsten P.; Lerch, Bradley A.; Wilmoth, Nathan G.; Kray, Nicholas; Gemeinhardt, Gregory

    2012-01-01

    Piezoelectric materials have been proposed as a means of decreasing turbomachinery blade vibration either through a passive damping scheme, or as part of an active vibration control system. For polymer matrix fiber composite (PMFC) blades, the piezoelectric elements could be embedded within the blade material, protecting the brittle piezoceramic material from the airflow and from debris. Before implementation of a piezoelectric element within a PMFC blade, the effect on PMFC mechanical properties needs to be understood. This study attempts to determine how the inclusion of a packaged piezoelectric patch affects the material properties of the PMFC. Composite specimens with embedded piezoelectric patches were tested in four-point bending, short beam shear, and flatwise tension configurations. Results show that the embedded piezoelectric material does decrease the strength of the composite material, especially in flatwise tension, attributable to failure at the interface or within the piezoelectric element itself. In addition, the sensing properties of the post-cured embedded piezoelectric materials were tested, and performed as expected. The piezoelectric materials include a non-flexible patch incorporating solid piezoceramic material, and two flexible patch types incorporating piezoelectric fibers. The piezoceramic material used in these patches was Navy Type-II PZT.

  12. Underwater characterizations of monolithic piezoceramic and 1-3 composite using a self-designed transducer

    NASA Astrophysics Data System (ADS)

    Saleem Mirza, Muhammad; Yasin, Tariq; Ikram, Masroor; Altaf, Muhammad; Mushtaq, Zahir; Nasir Khan, Muhammad

    2016-03-01

    Underwater characterizations of (Pb0.94Sr0.04)(Zr0.52Ti0.48)O3 (PZT) and PZT/araldite-F 1-3 composite were carried out through a self-designed transducer. Disc-shaped samples of bulk PZT and PZT/araldite-F composite were first characterized in air and then were assembled in the transducer individually. The transducer's underwater voltage receiving sensitivity (Sh) and transmitting voltage response (Sv) were investigated in the frequency range of 10-200 kHz (well below thickness mode resonance) using a calibrated projector and receiver method with pulse technique. Results revealed that the transducer made with composite sample exhibited better (Sh) values (-214 dB ref 1 V/µPa) due to ~295% higher piezoelectric voltage coefficient gh (30 × 10-3 Vm/N) of the composite compared to PZT. In addition, the transducer with the PZT sample showed better Sv values (80 dB ref 1 µPa/1 V at 1 m) due to the presence of planar mode peaks in the frequency range of 10-200 kHz. These results indicate that the monolithic piezoceramic can exhibit underwater Sv response in both planar and thickness resonance modes owing to the admittance peaks in these frequency regions.

  13. Micromachining techniques in developing high-frequency piezoelectric composite ultrasonic array transducers.

    PubMed

    Liu, Changgeng; Djuth, Frank T; Zhou, Qifa; Shung, K Kirk

    2013-12-01

    Several micromachining techniques for the fabrication of high-frequency piezoelectric composite ultrasonic array transducers are described in this paper. A variety of different techniques are used in patterning the active piezoelectric material, attaching backing material to the transducer, and assembling an electronic interconnection board for transmission and reception from the array. To establish the feasibility of the process flow, a hybrid test ultrasound array transducer consisting of a 2-D array having an 8 × 8 element pattern and a 5-element annular array was designed, fabricated, and assessed. The arrays are designed for a center frequency of ~60 MHz. The 2-D array elements are 105 × 105 μm in size with 5-μm kerfs between elements. The annular array surrounds the square 2-D array and provides the option of transmitting from the annular array and receiving with the 2-D array. Each annular array element has an area of 0.71 mm(2) with a 16-μm kerf between elements. The active piezoelectric material is (1 - x) Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT)/epoxy 1-3 composite with a PMN-PT pillar lateral dimension of 8 μm and an average gap width of ~4 μm, which was produced by deep reactive ion etching (DRIE) dry etching techniques. A novel electric interconnection strategy for high-density, small-size array elements was proposed. After assembly, the array transducer was tested and characterized. The capacitance, pulse-echo responses, and crosstalk were measured for each array element. The desired center frequency of ~60 MHz was achieved and the -6-dB bandwidth of the received signal was ~50%. At the center frequency, the crosstalk between adjacent 2-D array elements was about -33 dB. The techniques described herein can be used to build larger arrays containing smaller elements.

  14. Enhanced piezoelectric performance of composite sol-gel thick films evaluated using piezoresponse force microscopy.

    PubMed

    Liu, Yuanming; Lam, Kwok Ho; Kirk Shung, K; Li, Jiangyu; Zhou, Qifa

    2013-05-14

    Conventional composite sol-gel method has been modified to enhance the piezoelectric performance of ceramic thick films. Lead zirconate titanate (PZT) and lead magnesium niobate-lead titanate (PMN-PT) thick films were fabricated using the modified sol-gel method for ultrasonic transducer applications. In this work, piezoresponse force microscopy was employed to evaluate the piezoelectric characteristics of PZT and PMN-PT composite sol-gel thick films. The images of the piezoelectric response and the strain-electric field hysteresis loop behavior were measured. The effective piezoelectric coefficient (d33,eff) of the films was determined from the measured loop data. It was found that the effective local piezoelectric coefficient of both PZT and PMN-PT composite films is comparable to that of their bulk ceramics. The promising results suggest that the modified composite sol-gel method is a promising way to prepare the high-quality, crack-free ceramic thick films.

  15. Vibration control of pre-twisted rotating composite thin-walled beams with piezoelectric fiber composites

    NASA Astrophysics Data System (ADS)

    Choi, Seung-Chan; Park, Jae-Sang; Kim, Ji-Hwan

    2007-02-01

    Rotating composite beam structures like blades are applied in many fields of aerospace and mechanical engineering. In this research, bending vibration control of the pre-twisted rotating composite thin-walled beam is studied. The formulation is based on single cell composite beam including a warping function, centrifugal force, Coriolis acceleration, pre-twist angle and piezoelectric effect. A negative velocity feedback control algorithm is applied to realize the adaptive capability of the beam. Using a finite-element method, numerical simulations show that macro-fiber composite (MFC) actuators which are piezoelectric fiber composites and PVDF sensors can generate active vibration control effect. Relations between active vibration control effect and design parameters of beams such as rotating speeds, pre-twist angles and fiber orientations in a host structure are investigated in detail. Besides, a case study conformed that the effective damping performance can be obtained by suitable arrangement and distribution of the sensor and actuator pairs.

  16. Fabrication, characterization, and modeling of piezoelectric fiber composites

    NASA Astrophysics Data System (ADS)

    Lin, Xiujuan; Zhou, Kechao; Button, Tim W.; Zhang, Dou

    2013-07-01

    Piezoelectric fiber composites (PFCs) with interdigitated electrodes have attracted increasing interest in a variety of industrial, commercial, and aerospace markets due to their unique flexibility, adaptability, and improved transverse actuation performance. Viscous plastic processing technique was utilized for the fabrication of PFCs with customized feature sizes. The assembly parameters showed great influence on the performance of PFCs, which was verified by the finite element analysis. The cracks were identified in the fibers underneath the electrode finger after several millions cycles due to the stress and electric field concentration. The electrode finger width was an important structural parameter and showed great influence on the actuation performance and the stress distribution in the PFCs. The finite element analysis revealed that wider electrode finger would be beneficial for reducing the risk of materials failure with slight influence on the actuation performance.

  17. Micromechanical Prediction of the Effective Coefficients of Thermo-Piezoelectric Multiphase Composites

    NASA Technical Reports Server (NTRS)

    Aboudi, Jacob

    1998-01-01

    The micromechanical generalized method of cells model is employed for the prediction of the effective elastic, piezoelectric, dielectric, pyroelectric and thermal-expansion constants of multiphase composites with embedded piezoelectric materials. The predicted effective constants are compared with other micromechanical methods available in the literature and good agreements are obtained.

  18. Enhanced piezoelectric performance of (0.98-x)Bi(Sc{sub 3/4}In{sub 1/4})O{sub 3}-xPbTiO{sub 3}-0.02Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3} ternary high temperature piezoelectric ceramics

    SciTech Connect

    Chen Jianguo; Zhao Tianlong; Cheng Jinrong; Dong Shuxiang

    2013-04-14

    (0.98-x)Bi(Sc{sub 3/4}In{sub 1/4})O{sub 3}-xPbTiO{sub 3}-0.02Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3} (BSI-PT-PZN) high temperature piezoelectric ceramics were prepared by traditional solid-state reaction method. Combining X-ray diffraction results with piezoelectric data, it was found that the morphotropic phase boundary (MPB) occurred at x = 0.575. The piezoelectric constant d{sub 33}, curie temperature T{sub c}, and electromechanical coupling factor k{sub p} of BIS-PT-PZN ceramics with MPB composition were 427 pC/N, 412 Degree-Sign C, and 0.51, respectively. Furthermore, the strain of BIS-PT-PZN ceramics reached up to 0.25% under the electric field of 40 kV/cm. Temperature-dependent electromechanical coupling coefficient for MPB composition was stable from room temperature up to 350 Degree-Sign C. The piezoelectric properties of BIS-PT-PZN ceramics were comparable to that of 0.36BiScO{sub 3}-0.64PbTiO{sub 3} (BS-PT) ceramics, and the piezoelectric constant d{sub 33} of BIS-PT-PZN ceramics was about twice that of our previous reported 0.4Bi(Sc{sub 3/4}In{sub 1/4})O{sub 3}-0.6PbTiO{sub 3} (BSI-PT) ceramics. The reduction in the expensive Sc{sub 2}O{sub 3} content and comparable piezoelectric properties with BS-PT ceramics indicated that BIS-PT-PZN ceramics were promising for commercial applications as high temperature actuators and sensors.

  19. Effect of carbon nanotubes on properties of cement-sand-based piezoelectric composites

    NASA Astrophysics Data System (ADS)

    Kim, Sunjung; Zhao, Ping; Enemuoh, Emmanuel

    2015-04-01

    Carbon Nanotubes (CNTs) were dispersed in a cement-sand-based piezoelectric smart composite as conductive fillers to improve its poling efficiency, leading to a desirable piezoelectric effect. By introducing a small amount of CNTs, continuous electric networks between Lead Zirconate Titanate (PZT) particles were created, thus making the composite poling easier. Specimens were prepared by mixing PZT powders, Portland cement and sand with CNTs, followed by pressing it with a load frame system. The effect of quantity of CNTs ranging from 0 to 1.0 volume percent on properties of the composite, including its piezoelectric coefficient, dielectric constant and loss, and sensing effects, were characterized. It was found that the addition of CNTs facilitated effective poling at room temperature and improved the piezoelectric and dielectric properties of the composite. The composite modified by CNTs achieved optimal properties when the CNTs content was 0.7 vol.%.

  20. Piezoelectric Sol-Gel Composite Film Fabrication by Stencil Printing.

    PubMed

    Kaneko, Tsukasa; Iwata, Kazuki; Kobayashi, Makiko

    2015-09-01

    Piezoelectric films using sol-gel composites could be useful as ultrasonic transducers in various industrial fields. For sol-gel composite film fabrication, the spray coating technique has been used often because of its adaptability for various substrates. However, the spray technique requires multiple spray coating processes and heating processes and this is an issue of concern, especially for on-site fabrication in controlled areas. Stencil printing has been developed to solve this issue because this method can be used to fabricate thick sol-gel composite films with one coating process. In this study, PbTiO3 (PT)/Pb(Zr,Ti)O3 (PZT) films, PZT/PZT films, and Bi4Ti3O12 (BiT)/PZT films were fabricated by stencil printing, and PT/ PZT films were also fabricated using the spray technique. After fabrication, a thermal cycle test was performed for the samples to compare their ultrasonic performance. The sensitivity and signal-to-noise-ratio (SNR) of the ultrasonic response of PT/PZT fabricated by stencil printing were equivalent to those of PT/PZT fabricated by the spray technique, and better than those of other samples between room temperature and 300°C. Therefore, PT/PZT films fabricated by stencil printing could be a good candidate for nondestructive testing (NDT) ultrasonic transducers from room temperature to 300°C.

  1. Layerwise mechanics and finite element for the dynamic analysis of piezoelectric composite plates

    NASA Technical Reports Server (NTRS)

    Saravanos, Dimitris A.; Heyliger, Paul R.; Hopkins, Dale A.

    1996-01-01

    Laminate and structural mechanics for the analysis of laminated composite plate structures with piezoelectric actuators and sensors are presented. The theories implement layerwise representations of displacements and electric potential, and can model both the global and local electromechanical response of smart composite laminates. Finite-element formulations are developed for the quasi-static and dynamic analysis of smart composite structures containing piezoelectric layers. Comparisons with an exact solution illustrate the accuracy, robustness and capability of the developed mechanics to capture the global and local response of thin and/or thick laminated piezoelectric plates. Additional correlations and numerical applications demonstrate the unique capabilities of the mechanics in analyzing the static and free-vibration response of composite plates with distributed piezoelectric actuators and sensors.

  2. Piezoelectric properties of multiphase fibrous composites: Some theoretical results

    NASA Astrophysics Data System (ADS)

    Chen, Tungyang

    1993-11-01

    A NUMBER OF EXACT results are established for overall moduli of a piezoelectric composite medium consisting of many perfectly-bonded transversely isotropic phases of cylindrical shape and arbitrary transverse geometry. It is shown that for three-phase media of this type three universal relationships, which are independent of geometry at given volume fractions, connect six of these effective physical constants. When the phases have equal transverse rigidities in shear, exact values of certain overall moduli can be derived for multiphase systems. The explicit formulae depend solely on the concentrations and phase moduli and are unaffected by the transverse geometry of the inclusions. Specifically, seven out of a total of 10 overall moduli of a transversely isotropic composite can be found. The remaining three constants p, e15 and k11 are shown to obey an exact relation, which also applies to other physical phenomena, such as magnetoelectric and thermoelectric effects. The result is a generalization of the relations found by H ILL[J. Mech. Phys. Solids12, 199 (1964)] for purely elastic media and by Mendelson[J. Appl. Phys.46, 917 (1975)] for the purely dielectric problem.

  3. STRUCTURAL HEALTH MONITORING OF COMPOSITE LAMINATES WITH EMBEDDED PIEZOELECTRIC FIBERS

    SciTech Connect

    Lissenden, Cliff J.; Puthillath, Padma K.; Blackshire, James L.

    2009-03-03

    The actuation of ultrasonic guided waves in a carbon fiber reinforced polymer plate from embedded metal core piezoelectric fibers is studied for structural health monitoring applications. A linear array of fibers embedded at the midplane can generate guided waves transverse to the fiber direction. Finite element simulations show that a significant source influence is associated with the small diameter piezoelectric fibers.

  4. Piezoelectric properties of the new generation active matrix hybrid (micro-nano) composites

    NASA Astrophysics Data System (ADS)

    Parali, Levent; Şabikoğlu, İsrafil; Kurbanov, Mirza A.

    2014-11-01

    A hybrid piezoelectric composite structure is obtained by addition of nano-sized BaTiO3, SiO2 to the micro-sized PZT and polymers composition. Although the PZT material itself has excellent piezoelectric properties, PZT-based composite variety is limited. Piezoelectric properties of PZT materials can be varied with an acceptor or a donor added to the material. In addition, varieties of PZT-based sensors can be increased with doping polymers which have physical-mechanical, electrophysical, thermophysical and photoelectrical properties. The active matrix hybrid structure occurs when bringing together the unique piezoelectric properties of micro-sized PZT with electron trapping properties of nano-sized insulators (BaTiO3 or SiO2), and their piezoelectric, mechanic and electromechanic properties significantly change. In this study, the relationship between the piezoelectric constant and the coupling factor values of microstructure (PZT-PVDF) and the hybrid structure (PZT-PVDF-BaTiO3) composite are compared. The d33 value and the coupling factor of the hybrid structure have shown an average of 54 and 62% increase according to microstructure composite, respectively. In addition, the d33 value and the coupling factor of the hybrid structure (PZT-HDPE-SiO2) have exhibited about 68 and 52% increase according to microstructure composite (PZT-HDPE), respectively.

  5. Study of dielectric and piezoelectric properties of CNT reinforced PZT-PVA 0-3 composite

    NASA Astrophysics Data System (ADS)

    Vyas, Prince; Prajapat, Rampratap; Manmeeta, Saxena, Dhiraj

    2016-05-01

    Ferroelectric ceramic/polymer composites have the compliance of polymers which overcome the problems of brittleness in ceramics. By imbedding piezoelectric ceramic powder into a polymer matrix, 0-3 composites with good mechanical properties and high dielectric breakdown strength can be developed. The obtained composites of 0-3 connectivity exhibit the piezoelectric properties of ceramics and flexibility, strength and lightness of polymer. These composites can be used in vibration sensing and transducer applications specially as piezoelectric sensors. A potential way to improve piezoelectric& dielectric properties of theses composites is by inclusion of another conductive phase in these composites as reported in the literature. In present work, we prepared PZT-PVA 0-3 composites with 60% ceramic volume fraction reinforced with CNTs with volume ranging from 0 to 1.5 vol%. These CNT reinforced composites were obtained using hot press method with thickness of 200 µm having 0-3 conductivity. These composites were poled applying DC voltage. Dielectric properties of these samples were obtained in a wide frequency range (100 Hz to 1 Mhz) at room temperature. The piezoelectric properties of these composites were analyzed by measuring piezoelectric charge constants (d33). The dielectric and piezoelectric properties of these composites were studied as a function of CNT volume content. In these reinforced composites, CNTs act as a conductive filler dispersed in the matrix which in turn facilitates poling and results in an increase of the piezoelectric properties of the composite due to formation of percolation path through the composites. With a CNT content of 0.3 vol.% in PZT/PVA/CNTs, an increase of 61.3 % was observed in piezoelectric strain factors (d33). In these CNT reinforced composites, a substantial increase (approx. 67%) was also observed in dielectric constant and approximately 89% increase was observed in dielectric loss factor. Results so obtained are in the good

  6. Vibration reduction of a woven composite fan blade by piezoelectric shunted devices

    NASA Astrophysics Data System (ADS)

    Thierry, Olivier; De Smet, Olivier; Deü, Jean-François

    2016-09-01

    This study concerns the vibration reduction in the low frequency range of a composite fan blade of a turbojet engine with piezoelectric devices. The interest is to increase lifespan and avoid flutter phenomena by reducing the vibration amplitude. The solution considered in the work consists in using piezoelectric elements connected to a passive electric circuit usually called shunt. The use of woven composite materials for fan blades enables to plan on embedding piezoelectric materials, for instance in the form of patches inserted between the composite and the coating material. The work presented during this conference will illustrate the feasibility of a piezoelectric shunted device integrated in an industrial application that doesn't require electrical supply. For such a structure, it is shown that a purely passive resonant shunt can significantly reduce the level of vibration of the second bending mode and that a good correlation between experiments and simulations validates the best fitting finite element model.

  7. Modal characterization of composite flat plate models using piezoelectric transducers

    NASA Astrophysics Data System (ADS)

    Oliveira, É. L.; Maia, N. M. M.; Marto, A. G.; da Silva, R. G. A.; Afonso, F. J.; Suleman, A.

    2016-10-01

    This paper aims to estimate the modal parameters of composite flat plate models through Experimental Modal Analysis (EMA) using piezoelectric transducers. The flat plates are composed of three ply carbon-epoxy fibers oriented in the same direction. Five specimens with different unidirectional fiber nominal orientations θk (0o, 30o, 45o, 60o and 90o) were tested. These models were instrumented with one PZT (Lead Zirconate Titanate) actuator and one PVDF (Polyvinylidene Fluoride) sensor and an EMA was performed. The natural frequencies and damping factors estimated using only a single PVDF response were compared with the estimated results using twelve measurement points acquired by laser doppler vibrometry. For comparison purposes, the percentage error of each natural frequency estimation and the percentage error of the damping factor estimations were computed, as well as their averages. Even though the comparison was made between a SISO (Single-Input, Single-Output) and a SIMO (Single-Input, Multiple-Output) techniques, both results are very close. The vibration modes were estimated by means of laser measurements and were used in the modal validation. In order to verify the accuracy of the modal parameters, the Modal Assurance Criterion (MAC) was employed and a high correlation among mode shapes was observed.

  8. Piezoelectric and mechanical properties of fatigue resistant, self-healing PZT-ionomer composites

    NASA Astrophysics Data System (ADS)

    James, N. K.; Lafont, U.; van der Zwaag, S.; Groen, W. A.

    2014-05-01

    Piezoelectric ceramic-polymer composites with 0-3 connectivity were fabricated using lead zirconium titanate (PZT) powder dispersed in an ionomer (Zn ionomer) and its reference ethylene methacrylic acid copolymer (EMAA) polymer matrix. The PZT-Zn ionomer and PZT-EMAA composites were prepared by melt extrusion followed by hot pressing. The effects of poling conditions such as temperature, time and electric field on the piezoelectric properties of the composites were investigated. The experimentally observed piezoelectric charge coefficient and dielectric constant of the composites were compared with theoretical models. The results show that PZT-Zn ionomer composites have better piezoelectric properties compared to PZT-EMAA composites. The static and fatigue properties of the composites were investigated. The PZT-Zn ionomer composites were found to have excellent fatigue resistance even at strain levels of 4%. Due to the self-healing capabilities of the ionomer matrix, the loss of piezoelectric properties after high strain tensile cyclic loading could be partially recovered by thermal healing.

  9. Study on the radial composite piezoelectric ceramic transducer in radial vibration.

    PubMed

    Lin, Shuyu

    2007-03-01

    A new type of radial composite piezoelectric transducer in radial vibration is developed and analyzed. The radial composite transducer consists of a piezoelectric ceramic thin ring polarized in the thickness direction and a metal thin circular ring. They are connected together and excited to vibrate in the radial direction. The radial vibrations of a piezoelectric ceramic thin ring and a metal thin circular ring are analyzed, respectively. Their radial electro-mechanical equivalent circuits are obtained. Based on the electro-mechanical equivalent circuits and using the boundary conditions between the piezoelectric ceramic thin ring and the metal thin circular ring in the radial direction, the electro-mechanical equivalent circuit of the radial composite piezoelectric transducer is derived out and the resonance frequency equation is obtained. The relationship between the resonance frequency and the geometrical dimensions of the transducer is analyzed. Some radial composite piezoelectric transducers are designed and manufactured. The resonance frequencies and the anti-resonance frequencies, the electro-mechanical equivalent circuit parameters are measured. The effective electro-mechanical coupling coefficient and the mechanical quality factor are calculated. It is illustrated that the measured radial resonance frequencies are in good agreement with the theoretical results from the resonance frequency equation.

  10. The design and fabrication of highly piezoelectric polymeric composites and their use in responsive devices

    NASA Astrophysics Data System (ADS)

    Baur, Cary Allen

    In this work, novel approaches to the design of highly piezoelectric and flexible polymer composites were explored. Diverging from past work focused on the addition of piezoelectric particles into polymer matrices, this research explores the ability to increase the piezoelectric performance of a host polymer through the incorporation of charge via polarizable, organic particles. The ability to insert charge into polymers, known as electrets, is well documented but widely considered impractical because of the low lifetime and temperature resistance of the inserted charge. Through the addition of particles that are polarizable, charge can be inserted into a system in a stable manner that results in highly charged materials with long lifetimes. Here, carbon structures, such as Buckminsterfullerenes (C60) and single-walled nanotubes (SWNTs), were composited into poly(vinylidene difluoride) at very low loading levels (0.05-0.25 wt%), resulting in the ability to insert stable charge into the system. We show that these highly charged systems can result in a doubling of the piezoelectric response of the host polymer when optimized. The low amount of nanoparticle filler required to improve these materials allows for the advantageous properties of the polymer matrix such as flexibility and compliance to be preserved, enabling highly piezoelectric and flexible system. This dissertation outlines research efforts towards the design and fabrication of 1) polymer composites with high piezoelectric response, 2) piezoelectric composites with increased operating temperatures, 3) motion control devices that incorporate piezoelectric materials and shape memory polymers, and 4) artificial muscles with piezoelectric polymers. The piezoelectric polymer composites developed in this work have potential to be utilized as highly efficient, flexible energy harvesters that can be used to capture ambient energy from environmental vibrations and motion from the human body. As actuators, these

  11. 3D optical printing of piezoelectric nanoparticle-polymer composite materials.

    PubMed

    Kim, Kanguk; Zhu, Wei; Qu, Xin; Aaronson, Chase; McCall, William R; Chen, Shaochen; Sirbuly, Donald J

    2014-10-28

    Here we demonstrate that efficient piezoelectric nanoparticle-polymer composite materials can be optically printed into three-dimensional (3D) microstructures using digital projection printing. Piezoelectric polymers were fabricated by incorporating barium titanate (BaTiO3, BTO) nanoparticles into photoliable polymer solutions such as polyethylene glycol diacrylate and exposing to digital optical masks that could be dynamically altered to generate user-defined 3D microstructures. To enhance the mechanical-to-electrical conversion efficiency of the composites, the BTO nanoparticles were chemically modified with acrylate surface groups, which formed direct covalent linkages with the polymer matrix under light exposure. The composites with a 10% mass loading of the chemically modified BTO nanoparticles showed piezoelectric coefficients (d(33)) of ∼ 40 pC/N, which were over 10 times larger than composites synthesized with unmodified BTO nanoparticles and over 2 times larger than composites containing unmodified BTO nanoparticles and carbon nanotubes to boost mechanical stress transfer efficiencies. These results not only provide a tool for fabricating 3D piezoelectric polymers but lay the groundwork for creating highly efficient piezoelectric polymer materials via nanointerfacial tuning.

  12. The Effect of Temperature Dependent Material Nonlinearities on the Response of Piezoelectric Composite Plates

    NASA Technical Reports Server (NTRS)

    Lee, Ho-Jun; Saravanos, Dimitris A.

    1997-01-01

    Previously developed analytical formulations for piezoelectric composite plates are extended to account for the nonlinear effects of temperature on material properties. The temperature dependence of the composite and piezoelectric properties are represented at the material level through the thermopiezoelectric constitutive equations. In addition to capturing thermal effects from temperature dependent material properties, this formulation also accounts for thermal effects arising from: (1) coefficient of thermal expansion mismatch between the various composite and piezoelectric plies and (2) pyroelectric effects on the piezoelectric material. The constitutive equations are incorporated into a layerwise laminate theory to provide a unified representation of the coupled mechanical, electrical, and thermal behavior of smart structures. Corresponding finite element equations are derived and implemented for a bilinear plate element with the inherent capability to model both the active and sensory response of piezoelectric composite laminates. Numerical studies are conducted on a simply supported composite plate with attached piezoceramic patches under thermal gradients to investigate the nonlinear effects of material property temperature dependence on the displacements, sensory voltages, active voltages required to minimize thermal deflections, and the resultant stress states.

  13. Micromachining Techniques in Developing High-Frequency Piezoelectric Composite Ultrasonic Array Transducers

    PubMed Central

    Liu, Changgeng; Djuth, Frank T.; Zhou, Qifa; Shung, K. Kirk

    2014-01-01

    Several micromachining techniques for the fabrication of high-frequency piezoelectric composite ultrasonic array transducers are described in this paper. A variety of different techniques are used in patterning the active piezoelectric material, attaching backing material to the transducer, and assembling an electronic interconnection board for transmission and reception from the array. To establish the feasibility of the process flow, a hybrid test ultrasound array transducer consisting of a 2-D array having an 8 × 8 element pattern and a 5-element annular array was designed, fabricated, and assessed. The arrays are designed for a center frequency of ~60 MHz. The 2-D array elements are 105 × 105 μm in size with 5-μm kerfs between elements. The annular array surrounds the square 2-D array and provides the option of transmitting from the annular array and receiving with the 2-D array. Each annular array element has an area of 0.71 mm2 with a 16-μm kerf between elements. The active piezoelectric material is (1 − x) Pb(Mg1/3Nb2/3)O3−xPbTiO3 (PMN-PT)/epoxy 1–3 composite with a PMN-PT pillar lateral dimension of 8 μm and an average gap width of ~4 μm, which was produced by deep reactive ion etching (DRIE) dry etching techniques. A novel electric interconnection strategy for high-density, small-size array elements was proposed. After assembly, the array transducer was tested and characterized. The capacitance, pulse–echo responses, and crosstalk were measured for each array element. The desired center frequency of ~60 MHz was achieved and the −6-dB bandwidth of the received signal was ~50%. At the center frequency, the crosstalk between adjacent 2-D array elements was about −33 dB. The techniques described herein can be used to build larger arrays containing smaller elements. PMID:24297027

  14. Flexible nano-ZnO/polyvinylidene difluoride piezoelectric composite films as energy harvester

    NASA Astrophysics Data System (ADS)

    Bhunia, Ritamay; Das, Shirsendu; Dalui, Saikat; Hussain, Shamima; Paul, Rajib; Bhar, Radhaballav; Pal, Arun Kumar

    2016-07-01

    Nanogenerators (NGs) which harvest energy from mechanical vibration have attracted more attention in the past decade. Piezoelectric materials are the most promising candidates for developing NGs. Flexible free-standing nano-ZnO/PVDF composite films are prepared by incorporating different amounts of nano-ZnO fillers in PVDF matrix using sol-gel technique. Poled films show enhanced dielectric constant. The above free-standing films, with appropriate contacts, are subjected to energy harvesting studies. The output voltage increases with nano-ZnO loading in the PVDF matrix and shows enhanced effect for the poled films. Piezoelectric properties are investigated by measuring the piezoelectric charge constant ( d 33) and piezoelectric voltage constant ( g 33). A maximum AC output voltage ~4 V and output power of the order of few nanowatts are recorded for the nanogenerator which is used to light a red LED using a rectifying circuit through the discharging of a capacitor.

  15. Low cost fabrication of polymer composite (h-ZnO + PDMS) material for piezoelectric device application

    NASA Astrophysics Data System (ADS)

    Singh, Akanksha; Das, Sonatan; Bharathkumar, Mareddi; Revanth, D.; Karthik, ARB; Sudhakara Sastry, Bala; Ramgopal Rao, V.

    2016-07-01

    Flexible piezoelectric composites offer alternative and/or additional solutions to sensor, actuator and transducer applications. Here in this work, we have successfully fabricated highly flexible piezoelectric composites with poly dimethyl siloxane (PDMS) using herbal zinc oxide (h-ZnO) as filler having weight fractions up to 50 wt.% by solution casting of dispersions of h-ZnO in PDMS. Excellent piezo properties (Resonant frequency 935 Hz, d*33 29.76 pm V-1), physiochemical properties (Wurtzite structure ZnO, 380 nm absorbance) and mechanical properties (Young modulus 16.9 MPa) have been optimized with theoretical simulations and observed experimentally for h-ZnO + PDMS. As such, the demonstrated piezoelectric PDMS membranes combined with the excellent properties of these composites open new ways to ‘soft touch’ applications and could serve as a variety of soft and sensitive electromechanical transducers, which are desired for a variety of sensor and energy harvesting applications.

  16. High-frequency electromechanical properties of piezoelectric ceramic/polymer composites in broadband applications

    NASA Astrophysics Data System (ADS)

    Bowen, L. J.; Gururaja, T. R.

    1980-11-01

    Composites of piezoelectric ceramic (lead zirconate titanate) rods aligned in an epoxy resin matrix have been evaluated for broadband transducer applications. The rods are driven at their longitudinal mode resonance frequency and bandwidth is increased by fabricating the composite in a wedge configuration. The passband can be tailored as required by altering the surface profile of the device, and in principle bandwidths of almost 100 percent are possible. The attenuation properties of the polymer phase are of prime importance in mechanically decoupling adjacent piezoelectric elements. Acoustic signal attenuation in the polymer is accomplished by the series combination of acoustic impedence mismatch and classical transmission line attenuation. Experimental and theoretical considerations suggest the mechanical Q of the polymer is so low that the active elements are insignificantly damped. As a corollary, linear theory is not reliable for the prediction of dynamic mechanical properties of piezoelectric composites.

  17. 0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 Thick Films for High-Frequency Piezoelectric Transducer Applications

    NASA Astrophysics Data System (ADS)

    Uršič, Hana; Levassort, Franck; Holc, Janez; Lethiecq, Marc; Kosec, Marija

    2013-05-01

    The properties of 0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 (0.65PMN-0.35PT) thick films were studied for high-frequency piezoelectric transducer applications. The films were prepared by screen-printing a thick-film paste on platinized alumina substrates and subsequent sintering at 950 °C. The effective thickness-coupling factor of these films was close to 48%, which is comparable with bulk ceramics having the same compositions. Furthermore, simulations of two configurations representing one element of a high-frequency linear-array transducer (30 MHz) suggests that 0.65PMN-0.35PT thick-films in 50 Ω electrical matching environment improves the performance in comparison with standard Pb(Zr,Ti)O3 (PZT) compositions.

  18. Growth of high performance piezoelectric crystal Pb(Zn1/3Nb2/3)O3-PbTiO3 using PbO flux.

    PubMed

    Jin, Min; Xu, Jiayue; Shi, Minli; Wu, Xianjun; Tong, Jian

    2007-05-01

    Novel piezoelectric crystal (1-x)Pb(Zn(1/3)Nb(2/3))O(3)-xPbTiO(3) (PZNT) has attracted much attention due to its high piezoelectric properties and potential applications in medical ultrasonic devices, sonar transducers, solid state actuators. However, the applications of PZNT crystals are limited by the lack of a simple and reproducible growth technique. In this work, large size PZNT crystals were grown by the vertical Bridgman method using 50 mol% PbO as a flux. The growth conditions were optimized as mole ratio of raw materials and flux=1:1, soaking temperature 1150-1200 degrees C, soaking time 10 h, the lowering rate of the crucible 0.5 mm/h and the temperature gradient near solid-liquid interface about 50 degrees C/mm. The maximum size of as-grown PZNT crystal was about 60 mm in length. The crystal was oriented and its piezoelectric constant d(33) and coupling coefficient k(33) were measured over 2000pC/N and 0.92, respectively.

  19. Uniformity of direct and converse magnetoelectric effects in magnetostrictive-piezoelectric composites

    NASA Astrophysics Data System (ADS)

    Liu, Guoxi; Dong, Shuxiang

    2014-09-01

    In this paper, we theoretically and experimentally confirmed the uniformity of magnetoelectric (ME) coupling coefficients for the direct and converse ME (DME and CME) effects in longitudinal-transverse (L-T) mode magnetostrictive-piezoelectric two-phase composites, both at low frequencies and in the electromechanical resonance region. We also discussed the flaws in previous measurements of the ME coupling coefficients, which led to misunderstandings in the uniformity between the DME and CME effects. Our current work provided a correct method to correctly understand ME coupling in magnetostrictive-piezoelectric two-phase composites.

  20. Magnetoelectric Composites for 1.3 GHz Antennas

    NASA Astrophysics Data System (ADS)

    Petrov, R. V.; Tatarenko, A. S.; Srinivasan, G.; Bichurin, M. I.

    2008-03-01

    A microstrip miniaturized antenna based on magnetoelectric composite has been designed and characterized. Theoretical estimates of antenna properties are given. To miniaturize UHF antennas, one needs slow-wave topologies and magneto-electric (ME) materials with equal and high permeability and permittivity. Nickel Zinc Ferrites (Ni1-xZnxFe2O4, x=0-0.5, NZFO) are potential candidates for use as the magnetic phase in the composite since they have high permeability, in the range 4-50, and low magnetic loss tangent. The dielectric phase use is bismuth strontium titanates (Sr1-1.5xBixTiO3, 0.04composite substrate with dimensions 65 x 40 x 2.2 mm^3. The other side of the substrate has a metal ground plane. Measurements of transfer scattering parameter S21 are made. A miniaturization factor of 5-10 is achieved. The miniaturization methodology discussed here is useful for mobile communication platforms, radar systems, and remote-controlled ground based systems.

  1. Aligned porous barium titanate/hydroxyapatite composites with high piezoelectric coefficients for bone tissue engineering.

    PubMed

    Zhang, Yan; Chen, Liangjian; Zeng, Jing; Zhou, Kechao; Zhang, Dou

    2014-06-01

    It was proposed that the piezoelectric effect played an important physiological role in bone growth, remodelling and fracture healing. An aligned porous piezoelectric composite scaffold was fabricated by freeze casting hydroxyapatite/barium titanate (HA/BT) suspensions. The highest compressive strength and lowest porosity of 14.5MPa and 57.4% with the best parallelism of the pore channels were achieved in the HA10/BT90 composite. HA30/BT70 and HA10/BT90 composites exhibited piezoelectric coefficient d33 of 1.2 and 2.8pC/N, respectively, both of which were higher than the piezoelectric coefficient of natural bone. Increase of the solid loading of the suspension and solidification velocity led to the improvement of piezoelectric coefficient d33. Meanwhile, double-templates resulted in the coexistence of lamellar pores and aligned macro-pores, exhibiting the ability to produce an oriented long-range ordered architecture. The manipulation flexibility of this method indicated the potential for customized needs in the application of bone substitute. An MTT assay indicated that the obtained scaffolds had no cytotoxic effects on L929 cells.

  2. Energy harvesting from walking motion of a humanoid robot using a piezoelectric composite

    NASA Astrophysics Data System (ADS)

    Cha, Youngsu; Hong, Seokmin

    2016-10-01

    In this paper, we investigate the energy harvesting of a piezoelectric composite in a knee pad during walking motion. We use a humanoid robot as a test bed for the experiments using the knee pad. The humanoid wears the knee pad hosting the piezoelectric composite, and its operating knee motion mimics the walking based on the data captured from a human. The use of the humanoid enables the motion to be completely repeatable. We quantitatively study the energy harvesting by using the repeated motion. An electromechanical model for the piezoelectric energy harvester is used to estimate power transferred to varied load resistances under the repeated knee motion. With a good agreement between the experiments and the model predictions, we demonstrate power harvesting on the order of ten microWatts.

  3. Piezoelectric and electrostrictive materials for transducer applications

    NASA Astrophysics Data System (ADS)

    Cross, L. E.; Newnham, R. E.; Barsch, G. R.; Biggers, J. V.

    1984-05-01

    A wide range of materials and devices were covered, including composite materials for transducer applications, electrostriction, and conventional piezoelectrics. In piezoelectric composites, progress was made in 3:1 and 3:2 perforated PZT polymer composites, and in transverse reinforced composites. Finite element calculations of stress distributions in 1:3 PZT polymer composites were carried out. Fresnoite glass ceramics have exhibited extreme stability to hydrostatic pressure, and high sensitivity. A new water quenching technique was used to develop PbTiO3, and a detailed analysis of resonant modes of 1:3 PZT epoxy composites was carried out.

  4. Method of Fabricating NASA-Standard Macro-Fiber Composite Piezoelectric Actuators

    NASA Technical Reports Server (NTRS)

    High, James W.; Wilkie, W. Keats

    2003-01-01

    The NASA Macro-Fiber Composite actuator is a flexible piezoelectric composite device designed for controlling vibrations and shape deformations in high performance aerospace structures. A complete method for fabricating the standard NASA Macro-Fiber Composite actuator is presented in this document. When followed precisely, these procedures will yield devices with electromechanical properties identical to the standard actuator manufactured by NASA Langley Research Center.

  5. Radiation impedance and equivalent circuit for piezoelectric ultrasonic composite transducers of vibrational mode-conversion.

    PubMed

    Lin, Shuyu

    2012-01-01

    The piezoelectric ultrasonic composite transducer, which can be used in either gas or liquid media, is studied in this paper. The composite transducer is composed of a longitudinal sandwich piezoelectric transducer, a mechanical transformer, and a metal circular plate in flexural vibration. Acoustic radiation is produced by the flexural circular plate, which is excited by the longitudinal sandwich transducer and transformer. Based on the classic flexural theory of plates, the equivalent lumped parameters for a plate in axially symmetric flexural vibration with free boundary conditions are obtained. The radiation impedance of the plate is derived and the relationship between the radiation impedance and the frequency is analyzed. The equivalent circuits for the plate in flexural vibration and the composite transducer are given. The vibrational modes and the harmonic response of the composite piezoelectric transducer are simulated by the numerical method. Based on the theoretical and numerical analysis, two composite piezoelectric ultrasonic transducers are designed and manufactured, their admittance-frequency curves are measured, and the resonance frequency is obtained. The flexural vibrational displacement distribution of the transducer is measured with a laser scanning vibrometer. It is shown that the theoretical results are in good agreement with the measured resonance frequency and the displacement distribution.

  6. Ultrasonic IR thermographic inspection of graphite epoxy composite: a comparative study of piezoelectric and magnetostrictive stimulation

    NASA Astrophysics Data System (ADS)

    Swiderski, W.; Vavilov, V.

    2015-03-01

    In this paper the experimental results of piezoelectric and magnetostrictive ultrasonic stimulation are comparatively analyzed in the evaluation of impact damage in a graphite epoxy composite sample chosen for a round robin test. By comparing theoretical and experimental results, it is shown that the equivalent power of internal friction can reach some hundreds mill watt per a single crack.

  7. The electromechanical behavior of piezoelectric thin film composite diaphragms possessing in-plane stresses

    NASA Astrophysics Data System (ADS)

    Griffin, B. A.; Williams, M. D.; Wang, G.; Sankar, B. V.; Cattafesta, L. N.; Sheplak, M.

    2017-04-01

    Many piezoelectric microelectromechanical systems (MEMS) measure or generate acoustic signals via the motion of radially non-uniform, thin film composite plates. The composite layers provide piezoelectric actuation, structural support, electrode metallization, passivation, etc. Often, the layers are non-uniform over the plate and contain residual stresses introduced during the fabrication process. Accurate models of non-uniform composite plate mechanics are crucial for predicting and optimizing device performance. In this paper, an analytical solution for a radially non-uniform, piezoelectric, circular composite plate incorporating residual stress is derived. The analytical solution is compared to experimental measurements of a MEMS piezoelectric diaphragm. The results show the improved accuracy of the analytical model when including film stress, the speed of the analytical solution as compared to finite element analysis, the sensitivity of device performance to residual stress and the importance of accurate film stresses as model inputs. The analytical model presented is useful as a design optimization tool given the efficiency of the computational time, shown to be 275 times less than a comparable finite element analysis.

  8. Energy harvesting in pavement from passing vehicles with piezoelectric composite plate for ice melting

    NASA Astrophysics Data System (ADS)

    Faisal, Farjana; Wu, Nan; Kapoor, Kartik

    2016-04-01

    An energy harvester in the road pavement made from a piezoelectric composite plate is designed and studied to collect energy from the passing vehicles for the ice melting aim. Piezoelectric material has the ability to produce electric charge on its surface when strain takes place due to any external loading. Based on this property, a rectangular composite plate harvester is developed consisting of piezoelectric material as the energy generation coating layer and A514 steel as the substrate layer to realize the energy harvesting process from the variable pressure generated in the road pavement by passing vehicles. Based on Westergaards stress model, a numerical model is developed to calculate the three dimensional stress distribution in the pavement. Numerical simulations are conducted to study the optimization of various parameters of the harvester, such as depth of the harvester in the pavement, length and width as well as thicknesses of piezoelectric layer and the substrate. By taking in to consideration the maximum stress that can be sustained by both of the piezoelectric material and also the substrate material, an optimum design of the piezoelectric couple composite plate energy harvester is suggested. It is seen that the maximum output power, which can be generated by a single patch of 0.2m*0.2m*0.0026m dimension with a vehicle passing at 22.2 m/s, can reach up to 23.36 W. With the well-designed pavement energy harvesters, it is feasible to collect enough energy to rise the temperature of the ice with the thickness of 1cm covering a 5m width road by 20 degree Celsius within 2.5 hours. This technique can be applied to melt the ice on the roads and bridges especially in cold countries.

  9. Compliant Electrode and Composite Material for Piezoelectric Wind and Mechanical Energy Conversions

    NASA Technical Reports Server (NTRS)

    Chen, Bin (Inventor)

    2015-01-01

    A thin film device for harvesting energy from wind. The thin film device includes one or more layers of a compliant piezoelectric material formed from a composite of a polymer and an inorganic material, such as a ceramic. Electrodes are disposed on a first side and a second side of the piezoelectric material. The electrodes are formed from a compliant material, such as carbon nanotubes or graphene. The thin film device exhibits improved resistance to structural fatigue upon application of large strains and repeated cyclic loadings.

  10. Photopatternable nano-composite (SU-8/ZnO) thin films for piezo-electric applications

    NASA Astrophysics Data System (ADS)

    Kandpal, Manoj; Sharan, Chandrashekhar; Poddar, Pankaj; Prashanthi, K.; Apte, Prakash R.; Ramgopal Rao, V.

    2012-09-01

    Photo-curable nanocomposite material was formulated by embedding ZnO nanoparticles into a SU-8 matrix and studied for its piezoelectric properties for low cost fabrication of self-powered nanodevices. The piezoelectric coefficient of ZnO nanoparticles was observed to be ranging between 15 and 23 pm/V, which is the highest reported. These experimental studies support the recent theoretical predictions where the piezoelectric coefficients in ZnO nanoparticles were found to be higher compared to the thin films because of the surface relaxation induced volume reductions in the nanometer scale. The photo-curable property of these polymer composite films is exploited to demonstrate fabrication of a micro-cantilever test structure.

  11. An efficient finite element with layerwise mechanics for smart piezoelectric composite and sandwich shallow shells

    NASA Astrophysics Data System (ADS)

    Yasin, M. Yaqoob; Kapuria, S.

    2014-01-01

    In this work, we present a new efficient four-node finite element for shallow multilayered piezoelectric shells, considering layerwise mechanics and electromechanical coupling. The laminate mechanics is based on the zigzag theory that has only seven kinematic degrees of freedom per node. The normal deformation of the piezoelectric layers under the electric field is accounted for without introducing any additional deflection variables. A consistent quadratic variation of the electric potential across the piezoelectric layers with the provision of satisfying the equipotential condition of electroded surfaces is adopted. The performance of the new element is demonstrated for the static response under mechanical and electric potential loads, and for free vibration response of smart shells under different boundary conditions. The predictions are found to be very close to the three dimensional piezoelasticity solutions for hybrid shells made of not only single-material composite substrates, but also sandwich substrates with a soft core for which the equivalent single layer (ESL) theories perform very badly.

  12. Dynamic effective elastic modulus of polymer matrix composites with dense piezoelectric nano-fibers considering surface/interface effect

    NASA Astrophysics Data System (ADS)

    Fang, XueQian; Huang, MingJuan; Zhu, ZiTao; Liu, JinXi; Feng, WenJie

    2015-01-01

    Based on effective field method, the dynamic effective elastic modulus of polymer matrix composites embedded with dense piezoelectric nano-fibers is obtained, and the interacting effect of piezoelectric surfaces/interfaces around the nano-fibers is considered. The multiple scattering effects of harmonic anti-plane shear waves between the piezoelectric nano-fibers with surface/interface are averaged by effective field method. To analyze the interacting results among the random nano-fibers, the problem of two typical piezoelectric nano-fibers is introduced by employing the addition theorem of Bessel functions. Through numerical calculations, the influence of the distance between the randomly distributed piezoelectric nano-fibers under different surface/interface parameters is analyzed. The effect of piezoelectric property of surface/interface on the effective shear modulus under different volume fractions is also examined. Comparison with the simplified cases is given to validate this dynamic electro-elastic model.

  13. Single crystal PMN-PT/epoxy 1-3 composite for energy-harvesting application.

    PubMed

    Ren, Kailiang; Liu, Yiming; Geng, Xuecang; Hofmann, Heath F; Zhang, Qiming M

    2006-03-01

    One key parameter in using electroactive materials to harvest electric energy from mechanical sources is the energy conversion efficiency. Recently, it was shown that, in the relaxor ferroelectric PMN-PT single crystals, a very high longitudinal electromechanical coupling factor (>90%) can be obtained. This paper investigates energy harvesting using 1-3 composites of PMN-PT single crystals in a soft epoxy matrix. It is shown that 1-3 composites enable the single crystals operating in the longitudinal mode to achieve high efficiency for energy harvesting, and the soft-polymer, matrix-supported single-crystal rods maintain high mechanical integrity under different external loads. For comparison, 1-3 composites with piezoceramic PZT also are investigated in energy-harvesting applications, and the results show that the high coupling factor of single crystal PMN-PT 1-3 composites leads to much higher electric energy output for similar mechanical energy input. The harvested energy density of 1-3 composite with single crystal (22.1 mW/cm3 under a stress of 40.4 MPa) is about twice of that harvested with PZT ceramic 1-3 composite (12 mW/cm3 under a stress of 39 MPa). At a higher stress level, the harvested-energy density of 1-3 PMN-PT single crystal composite can reach 96 mW/cm3.

  14. Effect of Piezoelectric Implant on the Structural Integrity of Composite Laminates Subjected to Tensile Loads

    NASA Astrophysics Data System (ADS)

    Masmoudi, Sahir; El Mahi, Abderrahim; Turki, Saïd

    2016-07-01

    The embedment of sensors within composite structures gives the opportunity to develop smart materials for health and usage monitoring systems. This study investigates the use of acoustic emission monitoring with embedded piezoelectric sensor during mechanical tests in order to identify the effects of introducing the sensor into the composite materials. The composite specimen with and without embedded sensor were subject to tensile static and fatigue loading. The analysis and observation of AE signals show that the integration of a sensor presents advantage of the detection of the acoustic events and also show the presence of three or four types of damage during tests. The incorporation of piezoelectric sensor has a negligible influence on the mechanical properties of materials.

  15. Effect of Piezoelectric Implant on the Structural Integrity of Composite Laminates Subjected to Tensile Loads

    NASA Astrophysics Data System (ADS)

    Masmoudi, Sahir; El Mahi, Abderrahim; Turki, Saïd

    2017-02-01

    The embedment of sensors within composite structures gives the opportunity to develop smart materials for health and usage monitoring systems. This study investigates the use of acoustic emission monitoring with embedded piezoelectric sensor during mechanical tests in order to identify the effects of introducing the sensor into the composite materials. The composite specimen with and without embedded sensor were subject to tensile static and fatigue loading. The analysis and observation of AE signals show that the integration of a sensor presents advantage of the detection of the acoustic events and also show the presence of three or four types of damage during tests. The incorporation of piezoelectric sensor has a negligible influence on the mechanical properties of materials.

  16. 25 MHz ultrasonic transducers with lead-free piezoceramic, 1-3 PZT fiber-epoxy composite, and PVDF polymer active elements.

    PubMed

    Jadidian, Bahram; Hagh, Nader Marandian; Winder, Alan A; Safari, Ahmad

    2009-02-01

    This paper presents the fabrication and characterization of single-element ultrasonic transducers whose active elements are made of lead-free piezoceramic, 1-3 PZT/polymer composite and PVDF film. The lead free piezoelectric KNNLT- LS(K(0.44)Na(0.52)Li(0.04))(Nb(0.84)Ta(0.10)S(0.06)b)O(3) powders and ceramics were prepared under controlled humidity and oxygen flow rate during sintering. Due to its moderate longitudinal piezoelectric charge coefficient (175 pC/N) and k(t) of 0.50, the KNN-LT-LS composition may be a good candidate for high frequency transducer applications. PZT fibers with 25 microm diameter formed by the viscose suspension spinning process were incorporated into epoxy to fabricate 1-3 composites with the averaged k(t) = 0.64 and d(33) = 400 pC/N. Using KNN-LS-LT ceramic, 1-3 PZT fiber composite, and PVDF film, 3 different unfocused single element transducers with center frequencies of 25 MHz were fabricated. The acoustic characterization of the transducers demonstrated that wideband and low insertion loss could be obtained employing KNN-LS-LT ceramic. The -6 dB bandwidth and insertion loss were 70% and -21 dB, respectively. In comparison, the insertion loss of the ceramic transducer was much smaller than those made with 1-3 composite and PVDF film. This was attributed to closer electrical impedance match to 50 ohm and higher thickness coupling coefficient of the ceramic transducer.

  17. Fabrication and comparison of PMN-PT single crystal, PZT and PZT-based 1-3 composite ultrasonic transducers for NDE applications.

    PubMed

    Kim, Ki-Bok; Hsu, David K; Ahn, Bongyoung; Kim, Young-Gil; Barnard, Daniel J

    2010-08-01

    This paper describes fabrication and comparison of PMN-PT single crystal, PZT, and PZT-based 1-3 composite ultrasonic transducers for NDE applications. As a front matching layer between test material (Austenite stainless steel, SUS316) and piezoelectric materials, alumina ceramics was selected. The appropriate acoustic impedance of the backing materials for each transducer was determined based on the results of KLM model simulation. Prototype ultrasonic transducers with the center frequencies of approximately 2.25 and 5MHz for contact measurement were fabricated and compared to each other. The PMN-PT single crystal ultrasonic transducer shows considerably improved performance in sensitivity over the PZT and PZT-based 1-3 composite ultrasonic transducers.

  18. A vanadium-doped ZnO nanosheets-polymer composite for flexible piezoelectric nanogenerators.

    PubMed

    Shin, Sung-Ho; Kwon, Yang Hyeog; Lee, Min Hyung; Jung, Joo-Yun; Seol, Jae Hun; Nah, Junghyo

    2016-01-21

    We report high performance flexible piezoelectric nanogenerators (PENGs) by employing vanadium (V)-doped ZnO nanosheets (NSs) and the polydimethylsiloxane (PDMS) composite structure. The V-doped ZnO NSs were synthesized to overcome the inherently low piezoelectric properties of intrinsic ZnO. Ferroelectric phase transition induced in the V-doped ZnO NSs contributed to significantly improve the performance of the PENGs after the poling process. Consequently, the PENGs exhibited high output voltage and current up to ∼32 V and ∼6.2 μA, respectively, under the applied strain, which are sufficient to directly turn on a number of light emitting diodes (LEDs). The composite approach for PENG fabrication is scalable, robust, and reproducible during periodic bending/releasing over extended cycles. The approach introduced here extends the performance limits of ZnO-based PENGs and demonstrates their potential as energy harvesting devices.

  19. Vibration monitoring via nano-composite piezoelectric foam bushings

    NASA Astrophysics Data System (ADS)

    Bird, Evan T.; Merrell, A. Jake; Anderson, Brady K.; Newton, Cory N.; Rosquist, Parker G.; Fullwood, David T.; Bowden, Anton E.; Seeley, Matthew K.

    2016-11-01

    Most mechanical systems produce vibrations as an inherent side effect of operation. Though some vibrations are acceptable in operation, others can cause damage or signal a machine’s imminent failure. These vibrations would optimally be monitored in real-time, without human supervision to prevent failure and excessive wear in machinery. This paper explores a new alternative to currently-used machine-monitoring equipment, namely a piezoelectric foam sensor system. These sensors are made of a silicone-based foam embedded with nano- and micro-scale conductive particles. Upon impact, they emit an electric response that is directly correlated with impact energy, with no electrical power input. In the present work, we investigated their utility as self-sensing bushings on machinery. These sensors were found to accurately detect both the amplitude and frequency of typical machine vibrations. The bushings could potentially save time and money over other vibration sensing mechanisms, while simultaneously providing a potential control input that could be utilized for correcting vibrational imbalance.

  20. Measurements of dynamic Young's modulus in short specimens with the PUCOT. [Piezoelectric Ultrasonic Composite Oscillator Technique

    NASA Technical Reports Server (NTRS)

    Wickstrom, S. N.; Wolfenden, A.

    1990-01-01

    The piezoelectric ultrasonic composite oscillator technique (PUCOT) was used at frequencies in the range 40 to 150 kHz to measure dynamic Young's modulus for short-length single crystals of copper at temperatures in the range 25 to 650 C and for polycrystalline copper at room temperature. Corrections to the modulus for variations in length/diameter resulted in no loss of precision due to wave velocity dispersion.

  1. A vanadium-doped ZnO nanosheets-polymer composite for flexible piezoelectric nanogenerators

    NASA Astrophysics Data System (ADS)

    Shin, Sung-Ho; Kwon, Yang Hyeog; Lee, Min Hyung; Jung, Joo-Yun; Seol, Jae Hun; Nah, Junghyo

    2016-01-01

    We report high performance flexible piezoelectric nanogenerators (PENGs) by employing vanadium (V)-doped ZnO nanosheets (NSs) and the polydimethylsiloxane (PDMS) composite structure. The V-doped ZnO NSs were synthesized to overcome the inherently low piezoelectric properties of intrinsic ZnO. Ferroelectric phase transition induced in the V-doped ZnO NSs contributed to significantly improve the performance of the PENGs after the poling process. Consequently, the PENGs exhibited high output voltage and current up to ~32 V and ~6.2 μA, respectively, under the applied strain, which are sufficient to directly turn on a number of light emitting diodes (LEDs). The composite approach for PENG fabrication is scalable, robust, and reproducible during periodic bending/releasing over extended cycles. The approach introduced here extends the performance limits of ZnO-based PENGs and demonstrates their potential as energy harvesting devices.We report high performance flexible piezoelectric nanogenerators (PENGs) by employing vanadium (V)-doped ZnO nanosheets (NSs) and the polydimethylsiloxane (PDMS) composite structure. The V-doped ZnO NSs were synthesized to overcome the inherently low piezoelectric properties of intrinsic ZnO. Ferroelectric phase transition induced in the V-doped ZnO NSs contributed to significantly improve the performance of the PENGs after the poling process. Consequently, the PENGs exhibited high output voltage and current up to ~32 V and ~6.2 μA, respectively, under the applied strain, which are sufficient to directly turn on a number of light emitting diodes (LEDs). The composite approach for PENG fabrication is scalable, robust, and reproducible during periodic bending/releasing over extended cycles. The approach introduced here extends the performance limits of ZnO-based PENGs and demonstrates their potential as energy harvesting devices. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07185b

  2. Fabrication of Piezoelectric Ceramic/Polymer Composites by Injection Molding

    DTIC Science & Technology

    1993-04-15

    performed in polymer-lined containers using aged I zirconia media to minimize contamination. No evidence of contamination from milling was found in any of...several 50mm square solid polyurethane matrix composites were prepared and poled by both the3 contact method and corona poling. The as-encapsulated...composites were corona poled by Prof. Ahmad Safari at Rutgers University. No electrodes were required for corona poling. The poling conditions were: 70 C

  3. Carbon-Fiber Reinforced Plastic Passive Composite Damper by Use of Piezoelectric Polymer/Ceramic

    NASA Astrophysics Data System (ADS)

    Tanimoto, Toshio

    2002-11-01

    In this study, the passive damping of carbon-fiber reinforced plastic (CFRP) cantilever beams is examined using (1) interleaving of viscoelastic thermoplastic films, (2) piezoelectric polymer (PVDF) film interlayers and (3) surface-bonded piezoelectric ceramics. Introducing polyethylene-based film interlayers between composite plies resulted in a significant increase in the vibration loss factor. It is also shown that the vibration damping of CFRP laminates can be improved passively by means of PVDF film interlayers and resistively shunted, surface-bonded piezoelectric ceramic, PbZrO3-PbTiO3 (PZT) sheets. This paper also discusses the enhanced vibration damping of CFRP laminates with dispersed PZT particle interlayers. All these damping methods, interleaving of thermoplastic films, interlayers of PVDF films or dispersed PZT particles between composite plies, and resistively shunted, surface-bonded PZT sheets, can be jointly used to improve the damping of CFRP laminates/structures. The use of CFRP beams in combination with several damping concepts discussed here is promising for application in structures where light weight and improved vibration damping are desired.

  4. A comparative approach to predicting effective dielectric, piezoelectric and elastic properties of PZT/PVDF composites

    NASA Astrophysics Data System (ADS)

    Ahmad, Zeeshan; Prasad, Ashutosh; Prasad, K.

    2009-11-01

    The present study addresses the problem of quantitative prediction of effective relative permittivity, dielectric loss factor, piezoelectric charge coefficient, and Young's modulus of PZT/PVDF diphasic ceramic-polymer composite as a function of volume fraction of PZT in the different compositions. Theoretical results for effective relative permittivity derived from several dielectric mixture equations like those of Knott, Rother-Lichtenecker, Bruggeman, Maxwell-Wagner-Webmann-Skipetrov or Dias-Dasgupta, Furukawa, Lewin, Wiener, Jayasundere-Smith, Modified Cule-Torquato, Taylor, Poon-Shin and Rao et al. were fitted to the experimental data taken from previous works of Yamada et al. Similarly, the results for effective piezoelectric coefficient and Young's modulus, derived from different appropriate equations were fitted to the corresponding experimental data taken from the literature. The study revealed that only a few equations like modified Rother-Lichtenecker equation, Dias-Dasgupta equation and Rao equation for dielectric and piezoelectric properties while the four new equations developed in the present study of elastic property (Young's modulus) well fitted the corresponding experimental results. Further, the acceptable data put to various regression analyses showed that in most of the cases the third order polynomial regression analysis provided more acceptable fits.

  5. Reduction of Free Edge Peeling Stress of Laminated Composites Using Active Piezoelectric Layers

    PubMed Central

    Huang, Bin; Kim, Heung Soo

    2014-01-01

    An analytical approach is proposed in the reduction of free edge peeling stresses of laminated composites using active piezoelectric layers. The approach is the extended Kantorovich method which is an iterative method. Multiterms of trial function are employed and governing equations are derived by taking the principle of complementary virtual work. The solutions are obtained by solving a generalized eigenvalue problem. By this approach, the stresses automatically satisfy not only the traction-free boundary conditions, but also the free edge boundary conditions. Through the iteration processes, the free edge stresses converge very quickly. It is found that the peeling stresses generated by mechanical loadings are significantly reduced by applying a proper electric field to the piezoelectric actuators. PMID:25025088

  6. Elastic, dielectric, and piezoelectric properties of ceramic lead zirconate titanate/α-Al2O3 composites

    NASA Astrophysics Data System (ADS)

    Rybyanets, A. N.; Konstantinov, G. M.; Naumenko, A. A.; Shvetsova, N. A.; Makar'ev, D. I.; Lugovaya, M. A.

    2015-03-01

    The technology of producing ceramic lead zirconate titanate/α-Al2O3 composites has been developed. Elements of piezoactive composites containing from 0 to 60 vol % α-Al2O3 have been prepared. The elastic, dielectric, and piezoelectric parameters of the synthesized ceramic composites have been measured, and their microstructure has been studied. It has been found that the concentration dependences of the elastic and piezoelectric properties exhibit anomalies. The obtained data have been interpreted based on the percolation theory and the concept of microstructural constructing polycrystalline composition materials.

  7. Manufacturing and testing of active composite panels with embedded piezoelectric sensors and actuators: wires out by molded-in holes

    NASA Astrophysics Data System (ADS)

    Ghasemi-Nejhad, Mehrdad N.; Pourjalali, Saeid

    2003-08-01

    This work presents manufacturing and testing of active composite panels (ACPs) with embedded piezoelectric sensors and actuators. The composite material employed here is a plain weave carbon epoxy prepreg fabric with about 0.33 mm ply thickness. The piezoelectric patches employed here are Continuum Control Corporation, CCC, (recently Continuum Photonics, Inc) active fiber composite patches with 0.33 mm thickness, i.e. close to the composite ply thickness. Composite cut-out layers are used to fill the space around the embedded piezoelectric patches to minimize the problems associated with ply drops in composites. The piezoelectric patches were embedded inside the composite laminate. High-temperature wires were soldered to the piezoelectric leads, insulated from the carbon substructure by high-temperature materials, and were taken out of the composite laminates employing a molded-in hole technique that reduces the stress concentration as opposed to a drilled hole, and thereby enhancing the performance of the composite structure. The laminated ACP"s were co-cured inside an autoclave employing the cure cycle recommended by the composite material supplier. The curie temperature of the embedded piezoelectric patches should be well above the curing temperature of the composite materials as was the case here. The manufactured ACP beams and plates were trimmed and then tested for their functionality. Vibration suppression as well as simultaneous vibration suppression and precision positioning tests, using PID control as well as Hybrid Adaptive Control techniques were successfully conducted on the manufactured ACP beams and their functionality were demonstrated. Recommendations on the use of this embedding technique for ACPs are provided.

  8. Microwave Plasma Chemical Vapor Deposition of Carbon Coatings on LiNi1/3Co1/3Mn1/3O2 for Li-Ion Battery Composite Cathodes

    SciTech Connect

    Doeff, M.M.; Kostecki, R.; Marcinek, M.; Wilcoc, J.D.

    2008-12-10

    In this paper, we report results of a novel synthesis method of thin film conductive carbon coatings on LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} cathode active material powders for lithium-ion batteries. Thin layers of graphitic carbon were produced from a solid organic precursor, anthracene, by a one-step microwave plasma chemical vapor deposition (MPCVD) method. The structure and morphology of the carbon coatings were examined using SEM, TEM, and Raman spectroscopy. The composite LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} electrodes were electrochemically tested in lithium half coin cells. The composite cathodes made of the carbon-coated LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} powder showed superior electrochemical performance and increased capacity compared to standard composite LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} electrodes.

  9. Depolarization field effect on dielectric and piezoelectric properties of particulate ferroelectric ceramic-polymer composites

    NASA Astrophysics Data System (ADS)

    Ma, Fengde D.; Wang, Yu U.

    2015-03-01

    The effects of depolarization field on the dielectric and piezoelectric properties of ferroelectric ceramic particle-filled polymer-matrix composites are investigated at the underlying domain level. Phase field modeling and simulation reveals that the macroscopic properties of the composites are dominated by depolarization field effect, which depends on the arrangement and alignment rather than the size or internal grain structure of the ferroelectric particulates. It is found that 0-3 particulate composites with random dispersion of ferroelectric particles behave essentially like linear dielectric rather than ferroelectric materials, and domain-level analysis reveals the physical mechanism for lack of domain switching or hysteresis as attributed to strong depolarization effect. Thus, without effective reduction or elimination of the depolarization field, the composites cannot benefit from the functional fillers regardless of their superior properties. In order to exhibit the desired ferroelectric behaviors, it necessitates continuous ferroelectric phase connectivity in the composites.

  10. Designing and synthesis of a polymer matrix piezoelectric composite for energy harvesting

    NASA Astrophysics Data System (ADS)

    Biswal, Asutya Kumar; Das, Satyabati; Roy, Amritendu

    2017-02-01

    Now a day, a large variety of electronic and network devices require small yet steady power supply for operation. Traditionally, these devices are battery operated and the batteries are periodically charged for continuous operation. Often, the devices are so located that supply of power to recharge the batteries becomes challenging. Electrical energy harvesting by means of principle of piezoelectricity could be a viable solution to the above problem by means of providing a permanent power source. In this regard, piezoelectric lead zirconium titanate (PZT) was found to be a potential material. However, poor mechanical properties (brittleness) of bulk ceramic materials have been a concern for energy harvesting by means of mechanical motion (footsteps). In the present work, Pb(Zr 0.52 Ti 0.48)1‑x NbxO 3 at x=0.05 was prepared by conventional solid state synthesis route. XRD and SEM analyses were performed for structural characterization. PZT powders were found to be in single phase with tetragonal symmetry without any trace of a second phase. To render the required mechanical properties (flexibility), in the present work, we designed a polymer matrix ceramic composite without much compromising the piezoelectric properties. We prepared composite thick films of lead zirconium titanate (PZT) ceramic in poly vinylidene fluoride (PVDF) polymer matrix with varied composition of PZT from 10-50 vol %. The study of surface morphology by scanning electron microscope (SEM) shows good degree of dispersion of PZT in PVDF matrix. Ferroelectric characteristics of the composite films were studied by measuring the polarization-electric field hysteresis loops. Generated output voltage and current from the composite films are found to be approximately 0.35 volt and 4 nA, respectively.

  11. The effects of embedded piezoelectric fiber composite sensors on the structural integrity of glass-fiber-epoxy composite laminate

    NASA Astrophysics Data System (ADS)

    Konka, Hari P.; Wahab, M. A.; Lian, K.

    2012-01-01

    Piezoelectric fiber composite sensors (PFCSs) made from micro-sized lead zirconate titanate (PZT) fibers have many advantages over the traditional bulk PZT sensors for embedded sensor applications. PFCSs as embedded sensors will be an ideal choice to continuously monitor the stress/strain levels and health conditions of composite structures. PFCSs are highly flexible, easily embeddable, have high compatibility with composite structures, and also provides manufacturing flexibility. This research is focused on examining the effects of embedding PFCS sensors (macro-fiber composite (MFC) and piezoelectric fiber composite (PFC)) on the structural integrity of glass-fiber-epoxy composite laminates. The strengths of composite materials with embedded PFCSs and conventional PZT sensors were compared, and the advantages of PFCS sensors over PZTs were demonstrated. Initially a numerical simulation study is performed to understand the local stress/strain field near the embedded sensor region inside a composite specimen. High stress concentration regions were observed near the embedded sensor corner edge. Using PFCS leads to a reduction of 56% in longitudinal stress concentration and 38% in transverse stress concentration, when compared to using the conventional PZTs as embedded sensors. In-plane tensile, in-plane tension-tension fatigue, and short beam strength tests are performed to evaluate the strengths/behavior of the composite specimens containing embedded PFCS. From the tensile test it is observed that embedding PFCS and PZT sensors in the composite structures leads to a reduction in ultimate strength by 3 and 6% respectively. From the fatigue test results it is concluded that both embedded PFCS and PZT sensors do not have a significant effect on the fatigue behavior of the composite specimens. From the short beam strength test it is found that embedding PFCS and PZT sensors leads to a reduction in shear strength by 7 and 15% respectively. Overall the pure PZT sensors

  12. Longitudinal and transverse piezoelectric coefficients of lead zirconate titanate/vinylidene fluoride-trifluoroethylene composites with different polarization states

    NASA Astrophysics Data System (ADS)

    Zeng, R.; Kwok, K. W.; Chan, H. L. W.; Choy, C. L.

    2002-09-01

    Composite films comprising lead zirconate titanate (PZT) ceramic particles dispersed in a vinylidene fluoride-trifluoroethylene copolymer matrix have been prepared by compression molding. The ceramic and copolymer phases of the composite films are polarized separately, resulting in samples with three different polarization states: only the ceramic phase polarized, both phases polarized in the same direction, and two phases polarized in opposite directions. The effect of polarization state on the longitudinal and transverse piezoelectric coefficients (d33 and d31) of the composite film has been investigated as functions of ceramic volume fraction phic. When the ceramic and copolymer phases of a composite film are polarized in the same direction, their piezoelectric activities partially cancel each other, thereby giving almost zero piezoelectric activity at phi]c[approx0.4. On the other hand, when the phases of a composite film are polarized in opposite directions, their piezoelectric activities reinforce. However, depolarization of the ceramic phase is observed at high phic, leading to a decrease in the piezoelectric activity. The observed d33 and d31 values for the composite films agree well with theoretical predictions.

  13. A flexible, wave-shaped P(VDF-TrFE)/metglas piezoelectric composite for wearable applications

    NASA Astrophysics Data System (ADS)

    You, Sujian; Shi, Huaduo; Wu, Jingen; Shan, Liang; Guo, Shishang; Dong, Shuxiang

    2016-12-01

    In this work, a wave-shaped piezoelectric composite (WSPC) made of fine β-phase vinylidene fluoride trifluoroethylene copolymer (P(VDF-TrFE)) polymer and high-elastic FeSiB amorphous alloy (metglas) ribbon has been successfully fabricated for wearable device applications. X-ray diffraction and the Fourier Transform Infrared Spectrum studies reveal P(VDF-TrFE) exhibiting the fine β-phase. Both theoretical analysis and experimental results show that unique wave-shaped structure enhances the electromechanical coupling significantly, because of the combination piezoelectric effects of d33 and d31 modes in P(VDF-TrFE) polymer, as well as the enhanced effective piezoelectric coefficient caused by the pre-stretch in P(VDF-TrFE) film. Two application examples of WSPC, (i) mechanical force sensor or energy harvester, and (ii) the medical blood-pressure pulse sensor, have been investigated, which show that the WSPC is a promising candidate for future wearable device applications.

  14. Micromechanical analysis of constitutive properties of active piezoelectric structural fiber (PSF) composites

    NASA Astrophysics Data System (ADS)

    Ng, Kenny; Dai, Qingli

    2011-04-01

    Recent studies showed that the active piezoelectric structural fiber (PSF) composites may achieve significant and simultaneous improvements in sensing/actuating, stiffness, fracture toughness and vibration damping. These characteristics can be very important in the application of civil, mechanical and aerospace structures. The PSF is fabricated by coating the piezoceramic onto the silicon carbide core fiber with electrophoretic deposition (EPD) process to overcome the fragile nature of the monolithic piezoelectric materials. The PSF composite laminates are made of longitudinally poled PSFs that are unidirectionally deployed in the polymer binding matrix. The PSF laminate transducer has electrical inputs/outputs that are delivered through a separate etched interdigital electrode layer. This study analyzed the electromechanical properties with the generalized dilute scheme for active PSF composite laminate by considering multiinclusions. The well-known Mori-Tanaka approach was used to evaluate the concentration tensor in the multi-inclusion micromechanics model. To accurately predict the transverse properties, the extended role of mixtures were applied by considering the inclusions' geometry and shape. The micromechanical finite element modeling was also conducted with representative volume element (RVE) to compare with the micromechanics analysis on the electromechanical properties. The micromechanics analysis and finite element micromechanical modeling were conducted with varied fiber geometry dimensions and volume fractions. These comparison studies indicate the combined micromechanics models with the generalized dilute scheme can effectively predict the electro-elastic properties of multi-inclusion PSF composites.

  15. Tailoring of unipolar strain in lead-free piezoelectrics using the ceramic/ceramic composite approach

    SciTech Connect

    Khansur, Neamul H.; Daniels, John E.; Groh, Claudia; Jo, Wook; Webber, Kyle G.; Reinhard, Christina; Kimpton, Justin A.

    2014-03-28

    The electric-field-induced strain response mechanism in a polycrystalline ceramic/ceramic composite of relaxor and ferroelectric materials has been studied using in situ high-energy x-ray diffraction. The addition of ferroelectric phase material in the relaxor matrix has produced a system where a small volume fraction behaves independently of the bulk under an applied electric field. Inter- and intra-grain models of the strain mechanism in the composite material consistent with the diffraction data have been proposed. The results show that such ceramic/ceramic composite microstructure has the potential for tailoring properties of future piezoelectric materials over a wider range than is possible in uniform compositions.

  16. Shear strain mediated magneto-electric effects in composites of piezoelectric lanthanum gallium silicate or tantalate and ferromagnetic alloys

    SciTech Connect

    Sreenivasulu, G.; Piskulich, E.; Srinivasan, G.; Qu, P.; Qu, Hongwei; Petrov, V. M.; Fetisov, Y. K.; Nosov, A. P.

    2014-07-21

    Shear strain mediated magneto-electric (ME) coupling is studied in composites of piezoelectric Y-cut lanthanum gallium silicate (LGS) or tantalate (LGT) and ferromagnetic Fe-Co-V alloys. It is shown that extensional strain does not result in ME effects in these layered composites. Under shear strain generated by an ac and dc bias magnetic fields along the length and width of the sample, respectively, strong ME coupling is measured at low-frequencies and at mechanical resonance. A model is discussed for the ME effects. These composites of Y-cut piezoelectrics and ferromagnetic alloys are of importance for shear strain based magnetic field sensors.

  17. Tunable interdigital transducers made of piezoelectric macro-fiber composite

    NASA Astrophysics Data System (ADS)

    Mańka, Michał; Martowicz, Adam; Rosiek, Mateusz; Stepinski, Tadeusz; Uhl, Tadeusz

    2016-11-01

    The number of applications of Lamb waves (LWs) based structural health monitoring (SHM) has significantly increased in recent decades. The growth of interest results from several advantages of this diagnostic technique, that is, considerable mode selectivity and directivity that allow for the assessment of the technical condition of a monitored structure. Successful applications of LWs in the field of SHM stimulate continuous improvement of the transducers’ design to enable capturing more reliable diagnostic data. The paper introduces a new type of transducer that may be used in the LWs based SHM systems, namely tunable-interdigital transducer (T-IDT) based on macro-fiber composites (MFC). The authors provide a short overview on different types of transducers that may be used in SHM applications, followed by a detailed description of the structure of proposed T-IDT. Finally, the results of numerical and experimental tests carried out employing the proposed transducer are discussed and compared to those obtained with a traditional IDT.

  18. Glory of piezoelectric perovskites

    PubMed Central

    Uchino, Kenji

    2015-01-01

    This article reviews the history of piezoelectric perovskites and forecasts future development trends, including Uchino’s discoveries such as the Pb(Mg1/3Nb2/3)O3–PbTiO3 electrostrictor, Pb(Zn1/3Nb2/3)O3–PbTiO3 single crystal, (Pb, La)(Zr, Ti)O3 photostriction, and Pb(Zr, Ti)O3–Terfenol magnetoelectric composites. We discuss five key trends in the development of piezomaterials: performance to reliability, hard to soft, macro to nano, homo to hetero, and single to multi-functional. PMID:27877827

  19. Active control of geometrically nonlinear vibrations of functionally graded laminated composite plates using piezoelectric fiber reinforced composites

    NASA Astrophysics Data System (ADS)

    Panda, Satyajit; Ray, M. C.

    2009-08-01

    This paper deals with the geometrically nonlinear dynamic analysis of functionally graded (FG) laminated composite plates integrated with a patch of active constrained layer damping (ACLD) treatment. The constraining layer of the ACLD treatment is considered to be made of the piezoelectric fiber reinforced composite (PFRC) material. Each layer of the substrate FG laminated composite plate is made of fiber-reinforced composite material in which the fibers are longitudinally aligned in the plane parallel to the top or bottom surface of the layer and the layer is assumed to be graded in the thickness direction by way of varying the fiber orientation angle across its thickness according to a power-law. The novelty of the present work is that, unlike the traditional laminated composite plates, the FG laminated composite plates are constructed in such a way that the continuous variation of material properties and stresses across the thickness of the plates is achieved. The constrained viscoelastic layer of the ACLD treatment is modeled using the Golla-Hughes-McTavish (GHM) method. Based on the first-order shear deformation (FSDT) theory, a finite element model has been developed to model the open-loop and closed-loop nonlinear dynamics of the overall FG laminated composite plates. Both symmetric and asymmetric FG laminated composite plates are considered as the substrate plates for presenting the numerical results. The analysis suggests the potential use of the ACLD treatment with its constraining layer made of the PFRC material for active control of geometrically nonlinear forced vibrations of FG laminated composite plates. The effect of piezoelectric fiber orientation in the active constraining PFRC layer on the damping characteristics of the overall FG plates is also investigated.

  20. Piezoelectric and dielectric characterization of corona and contact poled PZT-epoxy-MWCNT bulk composites

    NASA Astrophysics Data System (ADS)

    Banerjee, S.; Cook-Chennault, K. A.; Du, W.; Sundar, U.; Halim, H.; Tang, A.

    2016-11-01

    Three-phase lead zirconate titanate (PZT, PbZr0.52Ti0.48O3)-epoxy-multi-walled carbon nanotube (MWCNT) bulk composites were prepared, where the volume fraction of PZT was held constant at 30%, while the volume fraction of the MWCNTs was varied from 1.0%-10%. The samples were poled using either a parallel plate contact or contactless (corona) poling technique. The piezoelectric strain coefficient (d 33), dielectric constant (ɛ), and dielectric loss tangent (tan δ) of the samples were measured at 110 Hz, and compared as a function of poling technique and volume fraction of MWCNTs. The highest values for dielectric constant and piezoelectric strain coefficients were 465.82 and 18.87 pC/N for MWCNT volume fractions of 10% and 6%, respectively. These values were obtained for samples that were poled using the corona contactless method. The impedance and dielectric spectra of the composites were recorded over a frequency range of 100 Hz-20 MHz. The impedance values observed for parallel-plate contact poled samples are higher than that of corona poled composites. The fractured surface morphology and distribution of the PZT particles and MWCNTs were observed with the aid of electron dispersion spectroscopy and a scanning electron microscope. The surface morphology of the MWCNTs was observed with the aid of a field emission transmission electron microscope.

  1. PZT/P(VDF-HFP) 0 3 composites as solvent-cast thin films: preparation, structure and piezoelectric properties

    NASA Astrophysics Data System (ADS)

    Wegener, Michael; Arlt, Kristin

    2008-08-01

    Composite films of lead zirconate titanate (PZT) and poly(vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)) were prepared as 100 µm thin films by solvent casting. Within the 0-3 composites, the ceramic-volume fraction was varied between 0.19 and 0.65, which yielded films with different structural and dielectric properties. These influenced the piezoelectric properties of the composite films found after electric poling, which was performed here at room temperature. The piezoelectric activity, with a maximum piezoelectric coefficient of 11 pC N-1 in the film-thickness direction, originates from the polarization of the embedded ceramic particles as proved by poling experiments in corona discharges as well as in direct contact.

  2. Interfacial enhancement of carbon fiber composites by generation 1-3 dendritic hexamethylenetetramine functionalization

    NASA Astrophysics Data System (ADS)

    Ma, Lichun; Meng, Linghui; Fan, Dapeng; He, Jinmei; Yu, Jiali; Qi, Meiwei; Chen, Zhongwu; Huang, Yudong

    2014-03-01

    PAN-based carbon fibers (CF) were functionalized with generation (n) 1-3 dendritic hexamethylenetetramine (HMTA) (denoted as CF-Gn-HMTA, n = 1, 2 and 3) in an attempt to improve the interfacial properties between carbon fibers and epoxy matrix. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), dynamic contact angle analysis (DCA), interfacial shear strength (IFSS) and single fiber tensile testing were carried out to investigate the functionalization process of carbon fibers and the interfacial properties of the composites. Experimental results showed that generation (n) 1-3 dendritic hexamethylenetetramine was grafted uniformly on the fiber surface through the chemical reaction, and then it increased significantly the fiber surface polarity and roughness. The surface energy and IFSS of carbon fibers increased obviously after the graft CF-G3-HMTA, by 147.6% and 81%, respectively. Generation (n) 1-3 dendritic hexamethylenetetramine enhanced effectively the interfacial adhesion of the composites by improving resin wettability, increasing chemical bonding and mechanical interlocking, and the interfacial adhesion increased with dendritic generation number. Moreover, the grafting of generation (n) 1-3 dendritic hexamethylenetetramine on the carbon fiber surface improved the fiber tensile strength, which is beneficial to the in-plane properties of the resulting composites.

  3. An aeroelastic analysis of helicopter rotor blades incorporating piezoelectric fiber composite twist actuation

    NASA Technical Reports Server (NTRS)

    Wilkie, W. Keats; Park, K. C.

    1996-01-01

    A simple aeroelastic analysis of a helicopter rotor blade incorporating embedded piezoelectric fiber composite, interdigitated electrode blade twist actuators is described. The analysis consist of a linear torsion and flapwise bending model coupled with a nonlinear ONERA based unsteady aerodynamics model. A modified Galerkin procedure is performed upon the rotor blade partial differential equations of motion to develop a system of ordinary differential equations suitable for numerical integration. The twist actuation responses for three conceptual full-scale blade designs with realistic constraints on blade mass are numerically evaluated using the analysis. Numerical results indicate that useful amplitudes of nonresonant elastic twist, on the order of one to two degrees, are achievable under one-g hovering flight conditions for interdigitated electrode poling configurations. Twist actuation for the interdigitated electrode blades is also compared with the twist actuation of a conventionally poled piezoelectric fiber composite blade. Elastic twist produced using the interdigitated electrode actuators was found to be four to five times larger than that obtained with the conventionally poled actuators.

  4. Dielectric and Piezoelectric Properties of PZT Composite Thick Films with Variable Solution to Powder Ratios

    PubMed Central

    Wu, Dawei; Zhou, Qifa; Shung, Koping Kirk.; Bharadwaja, Srowthi N.; Zhang, Dongshe; Zheng, Haixing

    2010-01-01

    The use of PZT films in sliver-mode high-frequency ultrasonic transducers applications requires thick, dense, and crack-free films with excellent piezoelectric and dielectric properties. In this work, PZT composite solutions were used to deposit PZT films >10 μm in thickness. It was found that the functional properties depend strongly on the mass ratio of PZT sol–gel solution to PZT powder in the composite solution. Both the remanent polarization, Pr, and transverse piezoelectric coefficient, e31,f, increase with increasing proportion of the sol–gel solution in the precursor. Films prepared using a solution-to-powder mass ratio of 0.5 have a remanent polarization of 8 μC/cm2, a dielectric constant of 450 (at 1 kHz), and e31,f = −2.8 C/m2. Increasing the solution-to-powder mass ratio to 6, the films were found to have remanent polarizations as large as 37 μC/cm2, a dielectric constant of 1250 (at 1 kHz) and e31,f = −5.8 C/m2. PMID:20376196

  5. High performance of macro-flexible piezoelectric energy harvester using a 0.3PIN-0.4Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 flake array

    NASA Astrophysics Data System (ADS)

    Zeng, Zhou; Xia, Rongyu; Gai, Linlin; Wang, Xian; Lin, Di; Luo, Haosu; Li, Faxin; Wang, Dong

    2016-12-01

    Harvesting energy from human motion to power wearable devices using flexible piezoelectric energy harvesters is becoming a hot research topic, since this approach could fix the charging problem related to batteries and would do no harm to the environment. Unlike nano-generators, which have a piezoelectric material thickness at the level of a few nm to a few μm, we present a high-performance macro-flexible piezoelectric energy harvester (MF-PEH) with a piezoelectric material thickness of 45 μm, based on a 0.3PIN-0.4PMN-0.3PT (PIMNT) long flake array with an optimized cut. The piezoelectric properties of (110)-oriented PIMNT were studied as a function of thickness and compared to those of 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMNT). The electrical properties of this device under different strain and load resistances are studied systematically. The results of our experiment show that under a strain of 0.225%, the open-circuit voltage and short-circuit current of MF-PEH reach levels as high as 23.2 V and 0.105 mA (at an excitation frequency of 1.1 Hz), respectively, with a maximum electric output power of 245 μW across a piezoelectric materials area of 400 mm2. We have also used the device to harvest mechanical energy from the motion of human knees and charge a battery successfully. Efficient conversion from mechanical energy to electric energy and large output power demonstrate that our MF-PEH is an important complement to flexible energy harvesters and a potential candidate as a self-powered source for wearable low-power electronics.

  6. Prototyping of radially oriented piezoelectric ceramic-polymer tube composites using fused deposition and lost mold processing techniques

    NASA Astrophysics Data System (ADS)

    McNulty, Thomas Francis

    Piezoelectric tube composite hydrophones of 3-1, 3-2, and 2-2 connectivity were developed using Fused Deposition (FD) and lost mold processing (LMP). In this work, a new series of thermoplastic binder formulations, named the ECG series, were developed for the FD process. The ECG-9 formulation exhibits mechanical, thermal, and rheological properties suitable for the Fused Deposition of functional lead zirconate titanate ceramic devices. This binder consists of 100 parts (by weight) Vestoplast 408, 20 parts Escorez 2520, 15 parts Vestowax A-227, and 5 parts Indopol H-1500. Oleic acid, oleyl alcohol, stearic acid, and stearyl alcohol (in toluene) were tested for use as a dispersant in the PZT/ECG-9 system. It was found that stearic acid adsorbs the most onto PZT powder, adsorbing 8.1 mg/m2. Using stearic acid, solutions of increasing concentration (5.0--50.0 g/l) were measured for adsorption. It was found that 30.0 g/l is the minimum concentration necessary for optimum surface coverage. The surfactant-coated powder was compounded with ECG-9 binder to create a 54 vol.% mix. The mix was extruded using a single screw extrusion apparatus into continuous lengths (>30 m) of 1.78 mm diameter filament. Fused Deposition was used to create composite designs of 3-1, 3-2, and 2-2 connectivity. After sintering, samples exhibit a sintered density greater than 97%. Sanders Prototyping (SPI) was used to manufacture molds for use with LMP techniques. Molds of 3-1, 3-2, and 2-2 connectivity were developed. The molds were infiltrated with a 55 vol.% aqueous based PZT slurry. The parts were subjected to a binder decomposition cycle, followed by sintering. Resultant samples were highly variable due to random macro-pores present in the samples after sintering. The resultant preforms were embedded in epoxy, and polished to dimensions of 8.0 mm inside diameter (ID), 14.0 mm outside diameter (OD), and 10.0 mm length (l) the OD and l dimensions are accurate to +/--2%, while the ID is accurate

  7. Piezoelectric properties and temperature stability of Mn-doped Pb(Mg1/3Nb2/3)-PbZrO3-PbTiO3 textured ceramics

    NASA Astrophysics Data System (ADS)

    Yan, Yongke; Cho, Kyung-Hoon; Priya, Shashank

    2012-03-01

    In this letter, we report the electromechanical properties of textured 0.4Pb(Mg1/3Nb2/3)O3-0.25PbZrO3-0.35PbTiO3 (PMN-PZT) composition which has relatively high rhombohedral to tetragonal (R-T) transition temperature (TR-T of 160 °C) and Curie temperature (TC of 234 °C) and explore the effect of Mn-doping on this composition. It was found that MnO2-doped textured PMN-PZT ceramics with 5 vol. % BaTiO3 template (T-5BT) exhibited inferior temperature stability. The coupling factor (k31) of T-5BT ceramic started to degrade from 75 °C while the random counterpart showed a very stable tendency up to 180 °C. This degradation was associated with the "interface region" formed in the vicinity of BT template. MnO2 doped PMN-PZT ceramics textured with 3 vol. % BT and subsequently poled at 140 °C (T-3BT140) exhibited very stable and high k31 (>0.53) in a wide temperature range from room temperature to 130 °C through reduction in the interface region volume. Further, the T-3BT140 ceramic exhibited excellent hard and soft combinatory piezoelectric properties of d33 = 720 pC/N, k31 = 0.53, Qm = 403, tan δ = 0.3% which are very promising for high power and magnetoelectric applications.

  8. Underwater thrust and power generation using flexible piezoelectric composites: an experimental investigation toward self-powered swimmer-sensor platforms

    NASA Astrophysics Data System (ADS)

    Erturk, Alper; Delporte, Ghislain

    2011-12-01

    Fiber-based flexible piezoelectric composites offer several advantages to use in energy harvesting and biomimetic locomotion. These advantages include ease of application, high power density, effective bending actuation, silent operation over a range of frequencies, and light weight. Piezoelectric materials exhibit the well-known direct and converse piezoelectric effects. The direct piezoelectric effect has received growing attention for low-power generation to use in wireless electronic applications while the converse piezoelectric effect constitutes an alternative to replace the conventional actuators used in biomimetic locomotion. In this paper, underwater thrust and electricity generation are investigated experimentally by focusing on biomimetic structures with macro-fiber composite piezoelectrics. Fish-like bimorph configurations with and without a passive caudal fin (tail) are fabricated and compared. The favorable effect of having a passive caudal fin on the frequency bandwidth is reported. The presence of a passive caudal fin is observed to bring the second bending mode close to the first one, yielding a wideband behavior in thrust generation. The same smart fish configuration is tested for underwater piezoelectric power generation in response to harmonic excitation from its head. Resonant piezohydroelastic actuation is reported to generate milli-newton level hydrodynamic thrust using milli-watt level actuation power input. The average actuation power requirement for generating a mean thrust of 19 mN at 6 Hz using a 10 g piezoelastic fish with a caudal fin is measured as 120 mW. This work also discusses the feasibility of thrust generation using the harvested energy toward enabling self-powered swimmer-sensor platforms with comparisons based on the capacity levels of structural thin-film battery layers as well as harvested solar and vibrational energy.

  9. Strain gauges of GaSbFeGa1.3 eutectic composites

    NASA Astrophysics Data System (ADS)

    Aliyev, M. I.; Khalilova, A. A.; Arasly, D. H.; Rahimov, R. N.; Tanoglu, M.; Ozyuzer, L.

    2004-12-01

    A needle-shaped metallic FeGa1.3 phase oriented in a specific direction and uniformly distributed within a GaSb matrix was grown by a vertical Bridgman method. Strain-gauge characteristics, such as strain-sensitivity coefficient (S), temperature coefficient of strain sensitivity (TCS) and temperature coefficient of resistance, of GaSb and GaSbFeGa1.3 eutectic alloy have been investigated in the range of 200 to 400 K under deformation up to strains of 1.3×10-3. The value of S of the GaSbFeGa1.3 composition is measured to be 40±5 and its TCS is about 0.2 % deg-1 when the current is perpendicular to the needles and the needles are parallel to the plane of the gauge substrate. The strain-sensitivity characteristics are linear and hysteresis free in the investigated temperature range in the aforementioned direction. It was found that GaSbFeGa1.3-based strain gauges possess better deformation characteristics than GaSb-based gauges.

  10. Performance of smart piezoelectric transducers for structural health monitoring on composite laminates in cryogenic environments

    NASA Astrophysics Data System (ADS)

    Tseng, Kevin K.; Tinker, Michael L.; Lassiter, John O.; Wang, Liangsheng

    2004-07-01

    An important way of increasing the payload in a reusable launch vehicle (RLV) is to replace heavy metallic materials by lightweight composite laminates. Engineers and scientists have studied many metallic materials thoroughly, due to the long history of practical usage in many aerospace and aeronautical structures. Compared to metallic materials, composite laminates are a relatively new material and therefore require more attention to ensure the safety and reliability. Among various parts and systems of the RLV, this study focuses on tanks containing cryogenic fuel. Historically, aluminum alloys have been used as the materials to construct fuel tanks for launch vehicles. To replace aluminum alloys with composite laminates or honeycomb materials, engineers have to make sure that the composites are free of defects before, during, and after launch. In addition to robust design and manufacturing procedures, the performance of the composite structures needs to be evaluated constantly. In recent years, the impedance-based health monitoring technique has shown its promise in many applications. This technique makes use of the special properties of smart piezoelectric materials to identify the change of material properties due to the nucleation and progression of damage. A major advantage of this technique is that the procedure is nondestructive in nature and does not perturb the properties and performance of the materials and structures. This paper reports the results of applying the impedance-based nondestructive testing technique to the damage identification of composite laminates at cryogenic temperature. These materials have potential application for fuel tanks in future RLV"s.

  11. Multilayered piezomagnetic/piezoelectric composites with periodic interfacial cracks subject to in-plane loading

    NASA Astrophysics Data System (ADS)

    Tian, Wenxiang; Zhong, Zheng; Li, Yaochen

    2016-01-01

    A two-dimensional fracture problem of periodically distributed interfacial cracks in multilayered piezomagnetic/piezoelectric composites is studied under in-plane magnetic or electric loading. The magnetic permittivity of the piezoelectric material and the dielectric constant of the piezomagnetic material are considered. A system of singular integral equations of the second kind with a Cauchy kernel is obtained by means of Fourier transform and further solved by using Jacobi polynomials. The problem is solved in the real domain by constructing real fundamental solutions. The primary interfacial fracture mechanic parameters, such as the stress intensity factors (SIFs), the electric displacement intensity factors (EDIFs), the magnetic induction intensity factors (MIIFs) and the energy release rates (ERRs) are then obtained. It is found that a magnetic or electric loading normal to the crack surfaces can lead to a mixture of mode I and mode II type stress singularities at the crack tips. Numerical results show that increasing the thickness of the active layer will favor the crack initiation. Inversely, increasing the thickness of the passive layer will retard the crack initiation. Furthermore, the results indicate that the crack initiation can be inhibited by adjusting the direction of the applied magnetic or electric loading.

  12. Analysis of the Impedance Resonance of Piezoelectric Multi-Fiber Composite Stacks

    NASA Technical Reports Server (NTRS)

    Sherrit, S.; Djrbashian, A.; Bradford, S C

    2013-01-01

    Multi-Fiber CompositesTM (MFC's) produced by Smart Materials Corp behave essentially like thin planar stacks where each piezoelectric layer is composed of a multitude of fibers. We investigate the suitability of using previously published inversion techniques for the impedance resonances of monolithic co-fired piezoelectric stacks to the MFCTM to determine the complex material constants from the impedance data. The impedance equations examined in this paper are those based on the derivation. The utility of resonance techniques to invert the impedance data to determine the small signal complex material constants are presented for a series of MFC's. The technique was applied to actuators with different geometries and the real coefficients were determined to be similar within changes of the boundary conditions due to change of geometry. The scatter in the imaginary coefficient was found to be larger. The technique was also applied to the same actuator type but manufactured in different batches with some design changes in the non active portion of the actuator and differences in the dielectric and the electromechanical coupling between the two batches were easily measureable. It is interesting to note that strain predicted by small signal impedance analysis is much lower than high field stains. Since the model is based on material properties rather than circuit constants, it could be used for the direct evaluation of specific aging or degradation mechanisms in the actuator as well as batch sorting and adjustment of manufacturing processes.

  13. Micromachined high frequency PMN-PT/epoxy 1-3 composite ultrasonic annular array.

    PubMed

    Liu, Changgeng; Djuth, Frank; Li, Xiang; Chen, Ruimin; Zhou, Qifa; Shung, K Kirk

    2012-04-01

    This paper reports the design, fabrication, and performance of miniature micromachined high frequency PMN-PT/epoxy 1-3 composite ultrasonic annular arrays. The PMN-PT single crystal 1-3 composites were made with micromachining techniques. The area of a single crystal pillar was 9×9 μm. The width of the kerf among pillars was ∼5 μm and the kerfs were filled with a polymer. The composite thickness was 25 μm. A six-element annular transducer of equal element area of 0.2 mm(2) with 16 μm kerf widths between annuli was produced. The aperture size the array transducer is about 1.5 mm in diameter. A novel electrical interconnection strategy for high density array elements was implemented. After the transducer was attached to the electric connection board and packaged, the array transducer was tested in a pulse/echo arrangement, whereby the center frequency, bandwidth, two-way insertion loss (IL), and cross talk between adjacent elements were measured for each annulus. The center frequency was 50 MHz and -6 dB bandwidth was 90%. The average insertion loss was 19.5 dB at 50 MHz and the crosstalk between adjacent elements was about -35 dB. The micromachining techniques described in this paper are promising for the fabrication of other types of high frequency transducers, e.g. 1D and 2D arrays.

  14. Micromachined High Frequency PMN-PT/Epoxy 1-3 Composite Ultrasonic Annular Array

    PubMed Central

    Liu, Changgeng; Djuth, Frank; Li, Xiang; Chen, Ruimin; Zhou, Qifa; Shung, K. Kirk

    2013-01-01

    This paper reports the design, fabrication, and performance of miniature micromachined high frequency PMN-PT/epoxy 1-3 composite ultrasonic annular arrays. The PMN-PT single crystal 1-3 composites were made with micromachining techniques. The area of a single crystal pillar was 9 μm × 9 μm. The width of the kerf among pillars was ~ 5 μm and the kerfs were filled with a polymer. The composite thickness was 25 μm. A six-element annular transducer of equal element area of 0.2 mm2 with 16 μm kerf widths between annuli was produced. The aperture size the array transducer is about 1.5 mm in diameter. A novel electrical interconnection strategy for high density array elements was implemented. After the transducer was attached to the electric connection board and packaged, the array transducer was tested in a pulse/echo arrangement, whereby the center frequency, bandwidth, two-way insertion loss (IL), and cross talk between adjacent elements were measured for each annulus. The center frequency was 50 MHz and -6 dB bandwidth was 90%. The average insertion loss was 19.5 dB at 50 MHz and the crosstalk between adjacent elements was about -35 dB. The micromachining techniques described in this paper are promising for the fabrication of other types of high frequency transducers e.g. 1D and 2D arrays. PMID:22119324

  15. Piezoelectric and Triboelectric Dual Effects in Mechanical-Energy Harvesting Using BaTiO3/Polydimethylsiloxane Composite Film.

    PubMed

    Suo, Guoquan; Yu, Yanhao; Zhang, Zhiyi; Wang, Shifa; Zhao, Ping; Li, Jianye; Wang, Xudong

    2016-12-21

    Piezoelectric and triboelectric nanogenerators have been developed as rising energy-harvesting devices in the past few years to effectively convert mechanical energy into electricity. Here, a novel hybrid piezo/triboelectric nanogenerator based on BaTiO3 NP/PDMS composite film was developed in a simple and low-cost way. The effects of the BTO content and polarization degree on the output performance were systematically studied. The device with 20 wt % BTO in PDMS and a 100-μm-thick film showed the highest output power. We also designed three measurement modes to record hybrid, triboelectric, and piezoelectric outputs separately with a simple structure that has only two electrodes. The hybrid output performance is higher than the tribo- and piezoelectric performances. This work will provide not only a new way to enhance the output power of nanogenerators, but also new opportunities for developing built-in power sources in self-powered electronics.

  16. Characteristics of magnetic force control device with magnetostrictive and piezoelectric laminate composite

    NASA Astrophysics Data System (ADS)

    Ueno, Toshiyuki; Qiu, Jinhao; Tani, Junji

    2003-08-01

    A magnetic force control device with laminate composite of giant magnetostrictive material (GMM) and piezo-electric material (PZT) is proposed. This magnetic force control is based on inverse magnetostrictive effect of a magnetic material, whereby the variation of stress applied on the material is converted to that of magnetic force via magnetic circuits. For the purpose of realizing the method in practical applications, disks of GMM and PZT are laminated to control the stress of GMM by electric field on PZT. Due to the capacitive properties of PZT, the device requires little electric energy hence generates no heat to maintain constant force. Furthermore compared with conventional electromagnetics, the device can be fabricated easily and in small size to be suitable for microactuators. This paper presents the principle of the magnetic force control by the lamination of GMM and PZT and investigates the static and dynamic characteristics of several devices to demonstrate their capabilities of the magnetic force control.

  17. Disbond detection with piezoelectric wafer active sensors in RC structures strengthened with FRP composite overlays

    NASA Astrophysics Data System (ADS)

    Giurgiutiu, Victor; Harries, Kent; Petrou, Michael; Bost, Joel; Quattlebaum, Josh B.

    2003-12-01

    The capability of embedded piezoelectric wafer active sensors (PWAS) to perform in-situ nondestructive evaluation (NDE) for structural health monitoring (SHM) of reinforced concrete (RC) structures strengthened with fiber reinforced polymer (FRP) composite overlays is explored. First, the disbond detection method were developed on coupon specimens consisting of concrete blocks covered with an FRP composite layer. It was found that the presence of a disbond crack drastically changes the electromechanical (E/M) impedance spectrum measured at the PWAS terminals. The spectral changes depend on the distance between the PWAS and the crack tip. Second, large scale experiments were conducted on a RC beam strengthened with carbon fiber reinforced polymer (CFRP) composite overlay. The beam was subject to an accelerated fatigue load regime in a three-point bending configuration up to a total of 807,415 cycles. During these fatigue tests, the CFRP overlay experienced disbonding beginning at about 500,000 cycles. The PWAS were able to detect the disbonding before it could be reliably seen by visual inspection. Good correlation between the PWAS readings and the position and extent of disbond damage was observed. These preliminary results demonstrate the potential of PWAS technology for SHM of RC structures strengthened with FRP composite overlays.

  18. Molecular modeling of the piezoelectric properties of ferroelectric composites containing polyvinylidene fluoride (PVDF) and either graphene or graphene oxide.

    PubMed

    Bystrov, Vladimir S; Bdikin, Igor K; Silibin, Maksim; Karpinsky, Dmitry; Kopyl, Svitlana; Paramonova, Ekaterina V; Goncalves, Gil

    2017-04-01

    Molecular modeling of ferroelectric composites containing polyvinylidene fluoride (PVDF) and either graphene (G) or graphene oxide (GO) were performed using the semi-empirical quantum approximation PM3 in HyperChem. The piezo properties of the composites were analyzed and compared with experimental data obtained for P(VDF-TrFE)-GO films. Qualitative agreement was obtained between the results of the modeling and the experimental results in terms of the properties of the measured effective piezoelectric coefficient d 33eff and its decrease in the presence of G/GO in comparison with the average computed piezoelectric coefficient . When models incorporating one or several G layers with 54 carbon atoms were investigated, the average piezoelectric coefficient was found to decrease to -9.8 pm/V for the one-sided model PVDF/G and to -18.98 pm/V for the sandwich model G/PVDF/G as compared with the calculated piezoelectric coefficient for pure PVDF ( = -42.2 pm/V computed in present work, and = -38.5 pm/V, obtained from J Mol Model 35 (2013) 19:3591-3602). When models incorporating one or several GO layers with 98 carbon atoms were considered, the piezoelectric coefficient was found to decrease to -14.6 pm/V for the one-sided PVDF/GO model and to -29.8 pm/V for the sandwich GO/PVDF/GO model as compared with the same calculated piezoelectric coefficient for pure PVDF.

  19. Composite manipulator utilizing rotary piezoelectric motors: new robotic technologies for Mars in-situ planetary science

    NASA Astrophysics Data System (ADS)

    Schenker, Paul S.; Bar-Cohen, Yoseph; Brown, D. K.; Lindemann, R. A.; Garrett, M. S.; Baumgartner, Eric T.; Lee, Sukhan; Lih, Shyh-Shiuh; Joffe, Benjamin

    1997-06-01

    We report a significant advance in space robotics design based on innovation of 3D composite structures and piezoelectric actuation. The essence of this work is development of a new all-composite robotic manipulator utilizing rotary ultrasonic motors (USM). 'MarsArmII' is 40% lighter than a prior 'MarsArmI' JPL design based in more massive, bulky hybrid metal-composite, joint-link system architecture and dc-motor driven actuation. MarsArmII is a four d.o.f. torso-shoulder- elbow, wrist-pitch robot of over two meters length, weighing four kilograms, and carrying a one kilogram multi-functional science effector with actuated opposable scoops, micro-viewing camera, and active tooling (abrader). MarsArmII construction is composite throughout, with all critical load-bearing joints and effector components being based in a new 3D air layup carbon fiber RTM composite process of our design, and links formed of 2D graphite epoxy. The 3D RTM composite is machinable by traditional metal shop practice, and in early tests such parts bench-marked favorably with aluminum based designs. Each arm link incorporates a surface mounted semiconductor strain gauge, enabling forced-referenced closed loop positioning. The principal arm joints are six in-lb rotary USMs acting under optically encoded PID servo control through harmonic drives. We have demonstrated the MarsArmII system for inverse kinematics positioning tasks (utilizing computer vision derived stereo workspace coordinates) that include simulated Martian soil trenching, sample acquisition and instrument transfers, and fresh rock surface exposure by abrasion.

  20. Predictive modeling of composite material degradation using piezoelectric wafer sensors electromechanical impedance spectroscopy

    NASA Astrophysics Data System (ADS)

    Gresil, Matthieu; Yu, Lingyu; Sutton, Mike; Guo, Siming; Pollock, Patrick

    2012-04-01

    The advancement of composite materials in aircraft structures has led to on increased need for effective structural health monitoring (SHM) technologies that are able to detect and assess damage present in composites structures. The work presented in this paper is interested in understanding using self-sensing piezoelectric wafer active sensors (PWAS) to conduct electromechanical impedance spectroscopy (EMIS) in glass fiber reinforced plastic (GFRP) to perform structures health monitoring. PWAS are bonded to the composite material and the EMIS method is used to analyze the changes in the structural resonance and anti-resonance. As the damage progresses in the specimen, the impedance spectrum will change. In addition, multi-physics based finite element method (MP-FEM) is used to model the electromechanical behavior of a free PWAS and its interaction with the host structure on which it is bonded. The MPFEM permits the input and the output variables to be expressed directly in electric terms while the two way electromechanical conversion is done internally in the MP_FEM formulation. To reach the goal of using the EMIS approach to detect damage, several damages models are generated on laminated GFRP structures. The effects of the modeling are carefully studied through experimental validation. A good match has been observed for low and very high frequencies.

  1. Geometrically nonlinear free vibration of shear deformable piezoelectric carbon nanotube/fiber/polymer multiscale laminated composite plates

    NASA Astrophysics Data System (ADS)

    Rafiee, M.; Liu, X. F.; He, X. Q.; Kitipornchai, S.

    2014-07-01

    The nonlinear free vibration of carbon nanotubes/fiber/polymer composite (CNTFPC) multi-scale plates with surface-bonded piezoelectric actuators is studied in this paper. The governing equations of the piezoelectric nanotubes/fiber/polymer multiscale laminated composite plates are derived based on first-order shear deformation plate theory (FSDT) and von Kármán geometrical nonlinearity. Halpin-Tsai equations and fiber micromechanics are used in hierarchy to predict the bulk material properties of the multiscale composite. The carbon nanotubes are assumed to be uniformly distributed and randomly oriented through the epoxy resin matrix. A perturbation scheme of multiple time scales is employed to determine the nonlinear vibration response and the nonlinear natural frequencies of the plates with immovable simply supported boundary conditions. The effects of the applied constant voltage, plate geometry, volume fraction of fibers and weight percentage of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) on the linear and nonlinear natural frequencies of the piezoelectric nanotubes/fiber/polymer multiscale composite plate are investigated through a detailed parametric study.

  2. Structural deformation of 0.74Pb(Mg1/3Nb2/3)O3-0.26PbTiO3 single crystal in 1-3 composites due to interface stresses and poling procedure optimization

    NASA Astrophysics Data System (ADS)

    Wang, Chunying; Sun, Enwei; Liu, Yingchun; Zhang, Rui; Yang, Bin; Cao, Wenwu

    2016-09-01

    Interface stresses strongly influence the functional property of 1-3 piezoelectric composites. Using the translucent nature of (1 - x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 single crystals, we have studied stress distributions and domain configuration changes during poling inside the crystal rods by polarizing light microscopy and piezoresponse force microscopy. It was found that the interface stresses due to interaction with polymeric filler led a deformed rhombohedral phase and caused incomplete poling near rod-edges. Compared with "hard" epoxy (Epotek301) filler, "soft" epoxy (Stycast) filler showed weaker impact on the crystals rods and less influence on domain configurations. We also show that high temperature poling (70 °C) can substantially improve the piezoelectric coefficient of composites filled with hard epoxy due to creeping above the glass transition Tg. Analytic stress distribution equations based on cylinder rods were modified to explain the physical principle and to predict the stress distribution for square rods case, which was verified by finite element simulation to be accurate within 5%.

  3. Rapid Multi-Damage Identification for Health Monitoring of Laminated Composites Using Piezoelectric Wafer Sensor Arrays

    PubMed Central

    Si, Liang; Wang, Qian

    2016-01-01

    Through the use of the wave reflection from any damage in a structure, a Hilbert spectral analysis-based rapid multi-damage identification (HSA-RMDI) technique with piezoelectric wafer sensor arrays (PWSA) is developed to monitor and identify the presence, location and severity of damage in carbon fiber composite structures. The capability of the rapid multi-damage identification technique to extract and estimate hidden significant information from the collected data and to provide a high-resolution energy-time spectrum can be employed to successfully interpret the Lamb waves interactions with single/multiple damage. Nevertheless, to accomplish the precise positioning and effective quantification of multiple damage in a composite structure, two functional metrics from the RMDI technique are proposed and used in damage identification, which are the energy density metric and the energy time-phase shift metric. In the designed damage experimental tests, invisible damage to the naked eyes, especially delaminations, were detected in the leftward propagating waves as well as in the selected sensor responses, where the time-phase shift spectra could locate the multiple damage whereas the energy density spectra were used to quantify the multiple damage. The increasing damage was shown to follow a linear trend calculated by the RMDI technique. All damage cases considered showed completely the developed RMDI technique potential as an effective online damage inspection and assessment tool. PMID:27153070

  4. Rapid Multi-Damage Identification for Health Monitoring of Laminated Composites Using Piezoelectric Wafer Sensor Arrays.

    PubMed

    Si, Liang; Wang, Qian

    2016-05-04

    Through the use of the wave reflection from any damage in a structure, a Hilbert spectral analysis-based rapid multi-damage identification (HSA-RMDI) technique with piezoelectric wafer sensor arrays (PWSA) is developed to monitor and identify the presence, location and severity of damage in carbon fiber composite structures. The capability of the rapid multi-damage identification technique to extract and estimate hidden significant information from the collected data and to provide a high-resolution energy-time spectrum can be employed to successfully interpret the Lamb waves interactions with single/multiple damage. Nevertheless, to accomplish the precise positioning and effective quantification of multiple damage in a composite structure, two functional metrics from the RMDI technique are proposed and used in damage identification, which are the energy density metric and the energy time-phase shift metric. In the designed damage experimental tests, invisible damage to the naked eyes, especially delaminations, were detected in the leftward propagating waves as well as in the selected sensor responses, where the time-phase shift spectra could locate the multiple damage whereas the energy density spectra were used to quantify the multiple damage. The increasing damage was shown to follow a linear trend calculated by the RMDI technique. All damage cases considered showed completely the developed RMDI technique potential as an effective online damage inspection and assessment tool.

  5. Screen-printed piezoelectric shoe-insole energy harvester using an improved flexible PZT-polymer composites

    NASA Astrophysics Data System (ADS)

    Almusallam, A.; Torah, R. N.; Zhu, D.; Tudor, M. J.; Beeby, S. P.

    2013-12-01

    This paper reports improved screen-printed piezoelectric composites that can be printed on fabrics or flexible substrates. The materials are flexible and are processed at lower temperature (130°C). One main PZT particle size (2μm) was mixed separately with smaller piezoelectric particles (0.1, 0.3 and 0.8μm) with different weight ratios to investigate the piezoelectric property d33. The blended PZT powder was then mixed with 40% polymer binder and printed on Alumina substrates. The applied poling field, temperature and time were 8MV/m, 160°C and 10min, respectively. The optimum material gives a d33 of 36pC/N with particle sizes of 2μm and 0.8μm and mixed percentages of 82% and 18%, respectively. A screen-printed piezoelectric shoe-insoles (PSI) has been developed as a self-powered force mapping sensor. The PSI was simulated, fabricated and tested. ANSYS results show that one element of PSI sole can produce an open- circuit voltage of 3V when a human of average weight of 70kg makes a gait strike. Experimental results show that one element produced 2V which is less than the simulated results because of the reduction of poling field for the practical device.

  6. P(VDF-TrFE)/BaTiO3 Nanoparticle Composite Films Mediate Piezoelectric Stimulation and Promote Differentiation of SH-SY5Y Neuroblastoma Cells.

    PubMed

    Genchi, Giada Graziana; Ceseracciu, Luca; Marino, Attilio; Labardi, Massimiliano; Marras, Sergio; Pignatelli, Francesca; Bruschini, Luca; Mattoli, Virgilio; Ciofani, Gianni

    2016-07-01

    Poly(vinylidene fluoride-trifluoroethylene, P(VDF-TrFE)) and P(VDF-TrFE)/barium titanate nanoparticle (BTNP) films are prepared and tested as substrates for neuronal stimulation through direct piezoelectric effect. Films are characterized in terms of surface, mechanical, and piezoelectric features before in vitro testing on SH-SY5Y cells. In particular, BTNPs significantly improve piezoelectric properties of the films (4.5-fold increased d31 ). Both kinds of films support good SH-SY5Y viability and differentiation. Ultrasound (US) stimulation is proven to elicit Ca(2+) transients and to enhance differentiation in cells grown on the piezoelectric substrates. For the first time in the literature, this study demonstrates the suitability of polymer/ceramic composite films and US for neuronal stimulation through direct piezoelectric effect.

  7. Investigation of magnetostrictive/piezoelectric multilayer composite with a giant zero-biased magnetoelectric effect

    NASA Astrophysics Data System (ADS)

    Lu, Caijiang; Li, Ping; Wen, Yumei; Yang, Aichao; He, Wei; Zhang, Jitao; Yang, Jin; Wen, Jing; Zhu, Yong; Yu, Miao

    2013-11-01

    In this paper, we investigate the resonance magnetoelectric (ME) effect in the middle supported multilayer composites consisting of high-permeability Fe-based nanocrystalline soft magnetic alloy Fe73.5Cu1Nb3Si13.5B9 (FeCuNbSiB), Nickel (Ni), and piezoelectric Pb(Zr1- x Ti x )O3 (PZT). The coupling effect between positive magnetostrictive FeCuNbSiB and negative magnetostrictive Ni results in the build-in magnetic bias due to their different magnetic permeability and coercivity. As a result, a giant resonance ME voltage coefficient ( α ME, r ) at zero DC magnetic bias field ( H dc) and multi-peaks of α ME, r for FeCuNbSiB/Ni/PZT/Ni/FeCuNbSiB composite are observed. The experimental results show that the giant zero-biased α ME, r strongly depends on the thickness of FeCuNbSiB ribbon. The maximum zero-biased α ME, r is up to 86 V/cm Oe for FeCuNbSiB/Ni/PZT/Ni/FeCuNbSiB with four-layer FeCuNbSiB ribbons, which is ˜500 times higher than that of the previously reported NKNLS-NZF/Ni/NKNLS-NZF trilayer composite. Compared with the peak α ME, r and the optimum H dc of Ni/PZT/Ni composite, the largest peak α ME, r of FeCuNbSiB/Ni/PZT/Ni/FeCuNbSiB composite with four-layer FeCuNbSiB ribbons increases ˜185 %, and the optimum H dc decreases ˜300 Oe, respectively. Based on the nonlinear magnetostrictive constitutive relation and the magnetoelectric equivalent circuit, a theoretical model of α ME, r versus H dc is built under free boundary conditions. Calculated zero-biased α ME, r and α ME, r versus H dc are in good agreement with the experimental data. This laminate composite shows promising applications for high-sensitivity power-free magnetic field sensors, zero-biased ME transducers and small-size energy harvesters.

  8. Experimental investigation of broadband energy harvesting of a bi-stable composite piezoelectric plate

    NASA Astrophysics Data System (ADS)

    Pan, Diankun; Ma, Benbiao; Dai, Fuhong

    2017-03-01

    In this work, a bi-stable vibration energy harvester is presented to scavenge energy from ambient vibrations over a wide frequency range. This bi-stable harvester consists of a bi-stable hybrid composite plate as host structure and several pieces of piezoelectric ceramics. Three linear harvesters with the same geometry were employed as the control samples to illustrate the advantages of this bi-stable harvester. The voltage–frequency responses were measured with different g-level excitations, and the output powers across various resistances were measured at different frequencies and accelerations. Unlike the linear harvesters which are effective only near their natural frequencies, the obvious nonlinearities of this bi-stable harvester broaden its working bandwidth. Additionally, the characteristics of this bi-stable host structure contribute to the output power. Under the same condition, when this bi-stable harvester is under cross-well oscillation pattern the maximum output powers are several times higher than those of the linear harvesters. The measured highest output power of this bi-stable harvester is 36.2 mW with 38 Hz frequency and 5g acceleration (g = 9.8 m s‑2).

  9. Research of Ultrasound-Mediated Transdermal Drug Delivery System Using Cymbal-Type Piezoelectric Composite Transducer

    NASA Astrophysics Data System (ADS)

    Huan, Huiting; Gao, Chunming; Liu, Lixian; Sun, Qiming; Zhao, Binxing; Yan, Laijun

    2015-06-01

    Transdermal drug delivery (TDD) implemented by especially low-frequency ultrasound is generally known as sonophoresis or phonophoresis which has drawn considerable wide attention. However, TDD has not yet achieved its full potential as an alternative to conventional drug delivery methods due to its bulky instruments. In this paper, a cymbal-type piezoelectric composite transducer (CPCT) which has advantages over a traditional ultrasound generator in weight, flexibility, and power consumption, is used as a substitute ultrasonicator to realize TDD. First, theoretical research on a CPCT based on the finite element analysis was carried out according to which a series of applicable CPCTs with bandwidths of 20 kHz to 100 kHz were elaborated. Second, a TDD experimental setup was built with previously fabricated CPCTs aimed at the administration of glucose. Finally, the TDD performance of glucose molecule transport in porcine skin was measured in vitro by quantifying the concentration of glucose, and the time variation curves were subsequently obtained. During the experiment, the driving wave form, frequency, and power consumption of the transducers were selected as the main elements which determined the efficacy of glucose delivery. The results indicate that the effectiveness of the CPCT-based delivery is constrained more by the frequency and intensity of ultrasound rather than the driving waveform. The light-weight, flexibility, and low-power consumption of a CPCT can potentially achieve effective TDD.

  10. Multi-axis force sensing using a resonant composite piezoelectric plate: model and experiments

    NASA Astrophysics Data System (ADS)

    Castaño-Cano, Davinson; Grossard, Mathieu; Hubert, Arnaud

    2015-05-01

    Wrist force/torque sensors used in robotic applications increase the performances and flexibility of the automated tasks. They also offer new possibilities in the manufacturing process, where physical contact between the work-piece and environment is required. The wide spreading of these sensors is for now restricted by their features. As an alternative to the existing strain-gauges force sensors, this paper presents a resonant composite structure, which is sensitive to multiple components of force that are considered via the pre-stress effect. Structurally bonded piezoelectric patches are used to bring the structure to its resonance, which is shifted according to applied forces. The relationship between force and frequency shift is modelled considering the multi-physics of this smart structure. This model is built using Hamilton's principle and takes into account pre-stress phenomena. A finite element model (FEM) based on Mindlin theory for plates, has been derived from the analytical model. The FEM model is implemented in MATLAB and compared with commercial FE software. Finally, an experimental prototype validates the model, and shows that it is possible to measure multiple force-components with one single sensing element such as a plate.

  11. Self-sensing tunable vibration absorber incorporating piezoelectric ceramic-magnetostrictive composite sensoriactuator

    NASA Astrophysics Data System (ADS)

    Duan, Yuan-Feng; Wing Or, Siu

    2011-08-01

    A novel self-sensing tunable vibration absorber (SSTVA) is developed for active absorption of vibrations in vibrating structures. The SSTVA consists of a piezoelectric ceramic-magnetostrictive composite sensoriactuator suspended in a mounting frame by two flexible beams connected to the axial ends of the sensoriactuator. The sensoriactuator serves to produce an axial force for tuning of the natural frequency of the SSTVA, to gather the signals associated with structural vibrations and to provide a lumped damped mass for the SSTVA. By monitoring the sensoriactuator output voltage while adjusting its input magnetic field (or electric current), the natural frequency of the SSTVA is tuned to the targeted resonance frequency of a structure. In this paper, the working principle, design prototype and operating performance of a 62.5 Hz SSTVA are reported. A high tunability of the natural frequency of 20% and a good sensing capability of vibrations comparable to a commercial accelerometer are obtained, together with a high absorbability of vibrations of ~ 4 dB in a steel-plate-neoprene resilient mount structure.

  12. Vibration characteristics of piezoelectric fiber composites under thermo-electro-mechanical loadings

    NASA Astrophysics Data System (ADS)

    Kim, Jun-Sik

    2011-11-01

    In this paper, vibration characteristics of piezoelectric fiber composite beams are presented. An asymptotic method based on virtual work principle is introduced first. The primary variables in thermo-electro-mechanical problems are asymptotically expanded in terms of the small parameter, which is done by taking the geometric slenderness of the beams. This subsequently renders a set of recursive virtual works at each order, in which the virtual works are separated into two parts: 2D microscopic problems and 1D macroscopic problems. These microscopic and macroscopic problems are systematically associated with each other, and thus the boundary conditions are affected by both of them. Cantilever beams under multiphysics environment are taken as a test-bed in order to illustrate the significance of edge effects and asymptotical correctness to the vibration characteristics of the beams. For the displacement prescribed boundary such as the clamped boundary, the stress weighted average conditions are applied to obtain the accurate prediction, which are known to be a good approximation (possibly the best candidate up to date).

  13. Vibration characteristics of piezoelectric fiber composites under thermo-electro-mechanical loadings

    NASA Astrophysics Data System (ADS)

    Kim, Jun-Sik

    2012-04-01

    In this paper, vibration characteristics of piezoelectric fiber composite beams are presented. An asymptotic method based on virtual work principle is introduced first. The primary variables in thermo-electro-mechanical problems are asymptotically expanded in terms of the small parameter, which is done by taking the geometric slenderness of the beams. This subsequently renders a set of recursive virtual works at each order, in which the virtual works are separated into two parts: 2D microscopic problems and 1D macroscopic problems. These microscopic and macroscopic problems are systematically associated with each other, and thus the boundary conditions are affected by both of them. Cantilever beams under multiphysics environment are taken as a test-bed in order to illustrate the significance of edge effects and asymptotical correctness to the vibration characteristics of the beams. For the displacement prescribed boundary such as the clamped boundary, the stress weighted average conditions are applied to obtain the accurate prediction, which are known to be a good approximation (possibly the best candidate up to date).

  14. Propagation of Shear Horizontal Waves in Laminated Composites Based on Differently Orientated Poled 0.72Pb(Mg1/3Nb2/3)O3-0.28PbTiO3 Single Crystals

    NASA Astrophysics Data System (ADS)

    Wang, Yu-Ling; Zhang, Rui; Sun, En-Wei; Song, Wei; Cao, Wen-Wu

    2013-09-01

    The propagation characteristics of shear horizontal waves in [001]c, [011]c and [111]c direction polarized 0.72Pb (Mg1/3Nb2/3) O3-0.28PbTiO3 (PMN-0.28PT) piezoelectric single crystals/polymer periodic laminated composites are studied by using the global matrix method. The numerical results show that the piezoelectric effect has a significant influence on the bandgap width of the composite structure containing [011]c and [111]c poled PMN-0.28PT, but little effect on the band structure of the system containing [001]c poled single crystal. In addition, the first bandgap (FBG) width of the composite structure depends strongly on the poling directions when the filling fraction of PMN-0.28PT is larger than 0.5, and its FBG starting frequency displays no distinct difference among the three polarization directions at all filling fractions. The reported results provide valuable guidelines for designing filters and transducers made of composite structures containing relaxor-based ferroelectric single crystals.

  15. Fabrication and in vitro biological properties of piezoelectric bioceramics for bone regeneration.

    PubMed

    Tang, Yufei; Wu, Cong; Wu, Zixiang; Hu, Long; Zhang, Wei; Zhao, Kang

    2017-02-27

    The piezoelectric effect of biological piezoelectric materials promotes bone growth. However, the material should be subjected to stress before it can produce an electric charge that promotes bone repair and reconstruction conducive to fracture healing. A novel method for in vitro experimentation of biological piezoelectric materials with physiological load is presented. A dynamic loading device that can simulate the force of human motion and provide periodic load to piezoelectric materials when co-cultured with cells was designed to obtain a realistic expression of piezoelectric effect on bone repair. Hydroxyapatite (HA)/barium titanate (BaTiO3) composite materials were fabricated by slip casting, and their piezoelectric properties were obtained by polarization. The d33 of HA/BaTiO3 piezoelectric ceramics after polarization was 1.3 pC/N to 6.8 pC/N with BaTiO3 content ranging from 80% to 100%. The in vitro biological properties of piezoelectric bioceramics with and without cycle loading were investigated. When HA/BaTiO3 piezoelectric bioceramics were affected by cycle loading, the piezoelectric effect of BaTiO3 promoted the growth of osteoblasts and interaction with HA, which was better than the effect of HA alone. The best biocompatibility and bone-inducing activity were demonstrated by the 10%HA/90%BaTiO3 piezoelectric ceramics.

  16. Fabrication and in vitro biological properties of piezoelectric bioceramics for bone regeneration

    PubMed Central

    Tang, Yufei; Wu, Cong; Wu, Zixiang; Hu, Long; Zhang, Wei; Zhao, Kang

    2017-01-01

    The piezoelectric effect of biological piezoelectric materials promotes bone growth. However, the material should be subjected to stress before it can produce an electric charge that promotes bone repair and reconstruction conducive to fracture healing. A novel method for in vitro experimentation of biological piezoelectric materials with physiological load is presented. A dynamic loading device that can simulate the force of human motion and provide periodic load to piezoelectric materials when co-cultured with cells was designed to obtain a realistic expression of piezoelectric effect on bone repair. Hydroxyapatite (HA)/barium titanate (BaTiO3) composite materials were fabricated by slip casting, and their piezoelectric properties were obtained by polarization. The d33 of HA/BaTiO3 piezoelectric ceramics after polarization was 1.3 pC/N to 6.8 pC/N with BaTiO3 content ranging from 80% to 100%. The in vitro biological properties of piezoelectric bioceramics with and without cycle loading were investigated. When HA/BaTiO3 piezoelectric bioceramics were affected by cycle loading, the piezoelectric effect of BaTiO3 promoted the growth of osteoblasts and interaction with HA, which was better than the effect of HA alone. The best biocompatibility and bone-inducing activity were demonstrated by the 10%HA/90%BaTiO3 piezoelectric ceramics. PMID:28240268

  17. Fabrication and in vitro biological properties of piezoelectric bioceramics for bone regeneration

    NASA Astrophysics Data System (ADS)

    Tang, Yufei; Wu, Cong; Wu, Zixiang; Hu, Long; Zhang, Wei; Zhao, Kang

    2017-02-01

    The piezoelectric effect of biological piezoelectric materials promotes bone growth. However, the material should be subjected to stress before it can produce an electric charge that promotes bone repair and reconstruction conducive to fracture healing. A novel method for in vitro experimentation of biological piezoelectric materials with physiological load is presented. A dynamic loading device that can simulate the force of human motion and provide periodic load to piezoelectric materials when co-cultured with cells was designed to obtain a realistic expression of piezoelectric effect on bone repair. Hydroxyapatite (HA)/barium titanate (BaTiO3) composite materials were fabricated by slip casting, and their piezoelectric properties were obtained by polarization. The d33 of HA/BaTiO3 piezoelectric ceramics after polarization was 1.3 pC/N to 6.8 pC/N with BaTiO3 content ranging from 80% to 100%. The in vitro biological properties of piezoelectric bioceramics with and without cycle loading were investigated. When HA/BaTiO3 piezoelectric bioceramics were affected by cycle loading, the piezoelectric effect of BaTiO3 promoted the growth of osteoblasts and interaction with HA, which was better than the effect of HA alone. The best biocompatibility and bone-inducing activity were demonstrated by the 10%HA/90%BaTiO3 piezoelectric ceramics.

  18. Phantom evaluation of stacked-type dual-frequency 1-3 composite transducers: A feasibility study on intracavitary acoustic angiography.

    PubMed

    Kim, Jinwook; Li, Sibo; Kasoji, Sandeep; Dayton, Paul A; Jiang, Xiaoning

    2015-12-01

    In this paper, we present phantom evaluation results of a stacked-type dual-frequency 1-3 piezoelectric composite transducer as a feasibility study for intracavitary acoustic angiography. Our previous design (6.5/30 MHz PMN-PT single crystal transducer) for intravascular contrast ultrasound imaging exhibited a contrast-to-tissue ratio (CTR) of 12 dB with a penetration depth of 2.5 mm. For improved penetration depth (>3 mm) and comparable contrast-to-tissue ratio (>12 dB), we evaluated a lower frequency 2/14 MHz PZT 1-3 composite transducer. Superharmonic imaging performance of this transducer and a detailed characterization of key parameters for acoustic angiography are presented. The 2/14 MHz arrangement demonstrated a -6 dB fractional bandwidth of 56.5% for the transmitter and 41.8% for the receiver, and produced sufficient peak-negative pressures (>1.5 MPa) at 2 MHz to induce a strong nonlinear harmonic response from microbubble contrast agents. In an in-vitro contrast ultrasound study using a tissue mimicking phantom and 200 μm cellulose microvessels, higher harmonic microbubble responses, from the 5th through the 7th harmonics, were detected with a signal-to-noise ratio of 16 dB. The microvessels were resolved in a two-dimensional image with a -6dB axial resolution of 615 μm (5.5 times the wavelength of 14 MHz waves) and a contrast-to-tissue ratio of 16 dB. This feasibility study, including detailed explanation of phantom evaluation and characterization procedures for key parameters, will be useful for the development of future dual-frequency array transducers for intracavitary acoustic angiography.

  19. Tunable passband in one-dimensional phononic crystal containing a piezoelectric 0.62Pb(Mg1/3Nb2/3)O3-0.38PbTiO3 single crystal defect layer

    NASA Astrophysics Data System (ADS)

    Wang, Yuling; Song, Wei; Sun, Enwei; Zhang, Rui; Cao, Wenwu

    2014-06-01

    Longitudinal acoustic wave propagation in one-dimensional phononic crystal containing a 0.2 mol% Fe-doped relaxor-based ferroelectric 0.62Pb(Mg1/3Nb2/3)O3-0.38PbTiO3 (PMN-0.38PT) single crystal defect layer is theoretically studied using the transfer matrix method. A passband can be produced in the stopband when the inserted PMN-0.38PT layer with thickness around its half wavelength. The frequency of the passband is closely dependent on the PMN-PT strain coefficient, suggesting that the band structure of phononic crystal is tunable by applying external electric field onto the piezoelectric crystal. Also, we investigated the influence of acoustic impedance of periodic constitutive materials (layers A and B) on the passband, where the bandwidth of the new passband becomes narrower as the acoustic impedance ratio of layer A and B (ZA/ZB) increase. The simulated results provide valuable guidance for designing tunable acoustic filters and switches made of phononic crystal consisting of the piezoelectric defect layer.

  20. Improving the dielectric and piezoelectric properties of screen-printed Low temperature PZT/polymer composite using cold isostatic pressing

    NASA Astrophysics Data System (ADS)

    Almusallam, A.; Yang, K.; Cao, Z.; Zhu, D.; Tudor, J.; Beeby, S. P.

    2014-11-01

    This paper reports an improvement in dielectric and piezoelectric properties of screen-printed PZT/polymer films for flexible electronics applications using Cold Isostatic Pressing (CIP). The investigation involved half and fully cured PZT/polymer composite pastes with weight ratio of 12:1 to investigate the effect of the CIP process on the piezoelectric and dielectric properties. It was observed that the highest dielectric and piezoelectric properties are achieved at pressures of 5 and 10 MPa for half and fully cured films respectively. The relative dielectric constants were 300 and 245 measured at 1 kHz for the half and fully cured samples. Using unoptimised poling conditions, the initial d33 values were 30 and 35 pC/N for the half and fully cured films, respectively. The fully cured sample was then poled using optimized conditions and demonstrated a d33 of approximately 44 pC/N which is an increase of 7% compared with non-CIP processed materials.

  1. Enhanced piezoelectric and mechanical properties of AlN-modified BaTiO3 composite ceramics.

    PubMed

    Xu, Dan; Wang, Lidong; Li, Weili; Wang, Wei; Hou, Yafei; Cao, Wenping; Feng, Yu; Fei, Weidong

    2014-07-14

    BaTiO3-xAlN (BT-xAlN) composite ceramics were prepared by conventional solid state reaction sintering. The effects of the AlN content on the crystalline structures, densities, and electrical and mechanical properties of the BT ceramics were investigated. The BT-1.5%AlN ceramic exhibits a good piezoelectric constant of 305 pC N(-1) and an improved Vickers hardness of 5.9 GPa. The enhanced piezoelectricity originates from interactions between defect dipoles and spontaneous polarization inside the domains due to the occurrence of local symmetry, caused by the preferential distribution of the Al(3+)-N(3-) pairs vertical to the c axis. The hardening of the material is attributed to the improved density, and particle and grain boundary strengthening. Our work indicates that if a suitable doping ion pair is designed, lead-free ceramic systems prepared from ordinary raw materials by a conventional sintering method have a high probability of exhibiting good piezoelectric and mechanical properties simultaneously.

  2. A comparative evaluation of piezoelectric sensors for acoustic emission-based impact location estimation and damage classification in composite structures

    NASA Astrophysics Data System (ADS)

    Uprety, Bibhisha; Kim, Sungwon; Mathews, V. John; Adams, Daniel O.

    2015-03-01

    Acoustic Emission (AE) based Structural Health Monitoring (SHM) is of great interest for detecting impact damage in composite structures. Within the aerospace industry the need to detect and locate these events, even when no visible damage is present, is important both from the maintenance and design perspectives. In this investigation, four commercially available piezoelectric sensors were evaluated for usage in an AE-based SHM system. Of particular interest was comparing the acoustic response of the candidate piezoelectric sensors for impact location estimations as well as damage classification resulting from the impact in fiber-reinforced composite structures. Sensor assessment was performed based on response signal characterization and performance for active testing at 300 kHz and steel-ball drop testing using both aluminum and carbon/epoxy composite plates. Wave mode velocities calculated from the measured arrival times were found to be in good agreement with predictions obtained using both the Disperse code and finite element analysis. Differences in the relative strength of the received wave modes, the overall signal strengths and signal-to-noise ratios were observed through the use of both active testing as well as passive steel-ball drop testing. Further comparative is focusing on assessing AE sensor performance for use in impact location estimation algorithms as well as detecting and classifying damage produced in composite structures due to impact events.

  3. Fingerprint test data report: FM 5834 test lots No. 1, 3, 4, and 5. [resin matrix composites

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Quality control testing is presented for various lots of resin matrix composites. The tests conducted were filler test, resin test, fabric test, and prepreg test for lots 1, 3, 4, and 5. The results of the tests are presented in chart forms.

  4. Passive damping of composite blades using embedded piezoelectric modules or shape memory alloy wires: a comparative study

    NASA Astrophysics Data System (ADS)

    Bachmann, F.; de Oliveira, R.; Sigg, A.; Schnyder, V.; Delpero, T.; Jaehne, R.; Bergamini, A.; Michaud, V.; Ermanni, P.

    2012-07-01

    Emission reduction from civil aviation has been intensively addressed in the scientific community in recent years. The combined use of novel aircraft engine architectures such as open rotor engines and lightweight materials offer the potential for fuel savings, which could contribute significantly in reaching gas emissions targets, but suffer from vibration and noise issues. We investigated the potential improvement of mechanical damping of open rotor composite fan blades by comparing two integrated passive damping systems: shape memory alloy wires and piezoelectric shunt circuits. Passive damping concepts were first validated on carbon fibre reinforced epoxy composite plates and then implemented in a 1:5 model of an open rotor blade manufactured by resin transfer moulding (RTM). A two-step process was proposed for the structural integration of the damping devices into a full composite fan blade. Forced vibration measurements of the plates and blade prototypes quantified the efficiency of both approaches, and their related weight penalty.

  5. Composite multi-modal vibration control for a stiffened plate using non-collocated acceleration sensor and piezoelectric actuator

    NASA Astrophysics Data System (ADS)

    Li, Shengquan; Li, Juan; Mo, Yueping; Zhao, Rong

    2014-01-01

    A novel active method for multi-mode vibration control of an all-clamped stiffened plate (ACSP) is proposed in this paper, using the extended-state-observer (ESO) approach based on non-collocated acceleration sensors and piezoelectric actuators. Considering the estimated capacity of ESO for system state variables, output superposition and control coupling of other modes, external excitation, and model uncertainties simultaneously, a composite control method, i.e., the ESO based vibration control scheme, is employed to ensure the lumped disturbances and uncertainty rejection of the closed-loop system. The phenomenon of phase hysteresis and time delay, caused by non-collocated sensor/actuator pairs, degrades the performance of the control system, even inducing instability. To solve this problem, a simple proportional differential (PD) controller and acceleration feed-forward with an output predictor design produce the control law for each vibration mode. The modal frequencies, phase hysteresis loops and phase lag values due to non-collocated placement of the acceleration sensor and piezoelectric patch actuator are experimentally obtained, and the phase lag is compensated by using the Smith Predictor technology. In order to improve the vibration control performance, the chaos optimization method based on logistic mapping is employed to auto-tune the parameters of the feedback channel. The experimental control system for the ACSP is tested using the dSPACE real-time simulation platform. Experimental results demonstrate that the proposed composite active control algorithm is an effective approach for suppressing multi-modal vibrations.

  6. Application of piezoelectric macro-fiber-composite actuators to the suppression of noise transmission through curved glass plates.

    PubMed

    Nováková, Katerina; Mokrý, Pavel; Václavík, Jan

    2012-09-01

    This paper analyzes the possibility of increasing the acoustic transmission loss of sound transmitted through planar or curved glass shells using attached piezoelectric macro fiber composite (MFC) actuators shunted by active circuits with a negative capacitance. The key features that control the sound transmission through the curved glass shells are analyzed using an analytical approximative model. A detailed analysis of the particular arrangement of MFC actuators on the glass shell is performed using a finite element method (FEM) model. The FEM model takes into account the effect of a flexible frame that clamps the glass shell at its edges. A method is presented for the active control of the Young's modulus and the bending stiffness coefficient of the composite sandwich structure that consists of a glass plate and the attached piezoelectric MFC actuator. The predictions of the acoustic transmission loss frequency dependencies obtained by the FEM model are compared with experimental data. The results indicate that it is possible to increase the acoustic transmission loss by 20 and 25 dB at the frequencies of the first and second resonant modes of the planar and curved glass shells, respectively, using the effect of the shunt circuit with a negative capacitance.

  7. Performance of Integrated Fiber Optic, Piezoelectric, and Shape Memory Alloy Actuators/Sensors in Thermoset Composites

    NASA Technical Reports Server (NTRS)

    Trottier, C. Michael

    1996-01-01

    Recently, scientists and engineers have investigated the advantages of smart materials and structures by including actuators in material systems for controlling and altering the response of structural environments. Applications of these materials systems include vibration suppression/isolation, precision positioning, damage detection and tunable devices. Some of the embedded materials being investigated for accomplishing these tasks include piezoelectric ceramics, shape memory alloys, and fiber optics. These materials have some benefits and some shortcomings; each is being studied for use in active material design in the SPICES (Synthesis and Processing of Intelligent Cost Effective Structures) Consortium. The focus of this paper concerns the manufacturing aspects of smart structures by incorporating piezoelectric ceramics, shape memory alloys and fiber optics in a reinforced thermoset matrix via resin transfer molding (RTM).

  8. Study of piezoelectric transducers in smart structure applications

    NASA Astrophysics Data System (ADS)

    Lam, Kwok Ho

    To develop a novel smart material in civil engineering applications, cement-based 1-3 composites have been fabricated and characterized. The feasibility of the embedded 1-3 composite transducers in structural monitoring applications have been demonstrated in this project. In the present work, piezoelectric ceramic discs and fibres were fabricated and used as the active phases of the 1-3 composites. Lead zirconate titanate (PZT) ceramic discs were fabricated using a conventional dry pressing method. All the parameters of PZT ceramics have been evaluated by a resonance technique. Crack-free PZT ceramic fibres were fabricated using a simple powder mixing method. The microstructural and electrical characterizations show that performance of the ceramic fibres can be comparable to that of the corresponding bulk ceramics. To study the piezoceramic/cement 1-3 composites, the properties of cement have been studied as a function of water content. The elastic properties of cement with different water/cement ratios were characterized using the ultrasonic immersion method. It was found that the cement paste with water/cement ratio of 0.5 is relatively "soft" to be used as the passive phase of a 1-3 composite. When comparing with the ceramics, the acoustic impedance of cement is much closer to that of concrete. Piezoelectric PZT/cement 1-3 composites with a wide range of the ceramic volume fraction (φ= 0.25--0.77) have been fabricated successfully using a dice-and-fill technique. Piezoelectric properties of the 1-3 composites were determined by a resonance technique. The characterization showed that the high piezoelectric characteristics of ceramics were maintained and the effective acoustic impedance of composites was reduced as expected. Even the phase matrix is the cement paste, the thickness electromechanical coupling coefficient kt of the 1-3 composites can be enhanced effectively which approaches to the k33 coefficient of the ceramics. The 1-3 composites were found to

  9. Electrohydroelastic Euler-Bernoulli-Morison model for underwater resonant actuation of macro-fiber composite piezoelectric cantilevers

    NASA Astrophysics Data System (ADS)

    Shahab, S.; Erturk, A.

    2016-10-01

    Bio-inspired hydrodynamic thrust generation using smart materials has received growing attention over the past few years to enable improved maneuverability and agility, small form factor, reduced power consumption, and ease of fabrication in next-generation aquatic swimmers. In order to develop a high-fidelity model to predict the electrohydroelastic dynamics of macro-fiber composite (MFC) piezoelectric structures, in this work, mixing rules-based (i.e. rule of mixtures) electroelastic mechanics formulation is coupled with the global electroelastic dynamics based on the Euler-Bernoulli kinematics and nonlinear fluid loading based on Morison’s semi-empirical model. The focus is placed on the dynamic actuation problem for the first two bending vibration modes under geometrically and materially linear, hydrodynamically nonlinear behavior. The electroelastic and dielectric properties of a representative volume element (piezoelectric fiber and epoxy matrix) between two subsequent interdigitated electrodes are correlated to homogenized parameters of MFC bimorphs and validated for a set of MFCs that have the same overhang length but different widths. Following this process of electroelastic model development and validation, underwater actuation experiments are conducted for different length-to-width aspect ratios (L/b) in quiescent water, and the empirical drag and inertia coefficients are extracted from Morison’s equation to establish the electrohydroelastic model. The repeatability of these empirical coefficients is demonstrated for experiments conducted using aluminum cantilevers of different aspect ratios with a focus on the first two bending modes. The convergence of the nonlinear electrohydroelastic Euler-Bernoulli-Morison model to its hydrodynamically linear counterpart for increased L/b values is also reported. The proposed model, its harmonic balance analysis, and experimental results can be used not only for underwater piezoelectric actuation, but also for

  10. Damage Detection in Cryogenic Composites for Space Applications Using Piezoelectric Wafer Active Sensors

    DTIC Science & Technology

    2008-01-01

    arrays of piezoelectric wafer active sensors (PWAS) bonded to a structure to both transmit and sense ultrasonic elastic waves for damage detection...Table 1. Table 1. Summary of PWAS damage detection methods. Wave Propagation Standing Wave Method amage D Pitch-Catch Pulse-echo Phased - Array ...conditions, and stress conditions. Results from these experiments indicate that a PWAS based array is capable of detecting low velocity impact damage

  11. Piezoelectric thick bismuth titanate/lead zirconate titanate composite film transducers for smart NDE of metals

    NASA Astrophysics Data System (ADS)

    Kobayashi, M.; Jen, C.-K.

    2004-08-01

    Thick film piezoelectric ceramic sensors have been successfully deposited on different metallic substrates with different shapes by a sol-gel spray technique. The ball-milled bismuth titanate fine powders were dispersed into PZT solution to achieve the gel. The films with desired thickness up to 200 µm have been obtained through the multilayer coating approach. These thick films were also effectively coated onto thin sheet metals of thickness down to 25 µm. Self-support films with flat and shell geometries were made. Piezoelectricity was achieved using the corona discharge poling method. The area of the top silver paste electrode was also optimized. The center frequencies of ultrasonic signals generated by these films ranged from 3.6 to 30 MHz and their bandwidth was broad as well. The ultrasonic signals generated and received by these ultrasonic transducers (UTs) operated in the pulse/echo mode had a signal to noise ratio more than 30 dB. The main advantages of such sensors are that they (1) do not need couplant, (2) can serve as piezoelectric and UT, (3) can be coated onto curved surfaces and (4) can operate up to 440 °C. The capability of these thick film UTs for non-destructive evaluation of materials at 440 °C has been demonstrated.

  12. The effect of polymer fill ratio in pillar structure for piezoelectric energy harvester

    NASA Astrophysics Data System (ADS)

    Lee, Kyoung-Soo; Shin, Dong-Jin; Chae, Moon-Soon; Koo, Sang-Mo; Ha, Jae-Geun; Koh, Jung-Hyuk; Cho, Kyung-Ho; Seo, Chang-Eui; Jeong, Soon-Jong

    2013-07-01

    One method of energy harvesting is to use piezoelectric devices, which are able to interchange electrical energy and mechanical strain or vibration. This study is to experimentally investigate the behavior of a piezoelectric energy harvester that was constructed with an array of pillar structures made of 0.2(PbMg1/3Nb2/3O3)-0.8(PbZr0.475Ti0.525O3) with polymer fill. Additionally, the aim of this study is to optimize the fill ratio of the composite piezoelectric ceramics and polymer structure. 0.2(PbMg1/3Nb2/3O3)-0.8(PbZr0.475Ti0.525O3) ceramics were employed as piezoelectric ceramic pillars, prepared in a rectangular shape. These piezoelectric ceramic pillars were sintered separately and attached to a bottom metallic electrode with poled states. The optimum ratio of ceramic pillar and elastic polymer ratio will be discussed. Piezoelectric properties will be discussed including the piezoelectric constant, piezoelectric voltage constants, and electromechanical coupling coefficient. We will present how the harvested energy depends on the lead resistor.

  13. Step-down piezoelectric transformer fabricated with (1-x)Pb(Mg(1/3)Nb(2/3))O3-xPbTiO3 single crystal.

    PubMed

    Wang, Feifei; Shi, Wangzhou; Luo, Haosu

    2010-04-01

    In present work, a ring-type unipoled step-down piezoelectric transformer with the dimensions of Phi16x0.7 mm(3) was designed and fabricated using relaxor ferroelectric single crystal (1-x)Pb(Mg(1/3)Nb(2/3))O(3)-xPbTiO(3) (PMN-PT). Both the input and output parts of this transformer were poled along the thickness direction, utilizing the radial vibration mode of PMN-PT. The electrical measurement results indicated that under the matching load resistance of 257 Omega, a voltage transformation ratio of 0.44 was obtained at the resonance frequency of 105 kHz. The frequency and load dependences of this transformer were also systematically studied and discussed. With the input voltage increasing, a maximum output power of about 0.9 W was obtained with the temperature rise less than 5 degrees C. This step-down single-crystal transformer show potential applications in compact-size, small-power ac-dc converters.

  14. Shear-Mode-Based Cantilever Driving Low-Frequency Piezoelectric Energy Harvester Using 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3.

    PubMed

    Zeng, Zhou; Ren, Bo; Gai, Linlin; Zhao, Xiangyong; Luo, Haosu; Wang, Dong

    2016-08-01

    Energy harvesting from external mechanical excitation has become a hot interest area, and relaxor piezoelectric single crystal ( 1 - x )Pb(Mg1/3Nb2/3)O3- x PbTiO3 (PMN- x PT or PMN-PT) has attracted continuous attention due to the well-known ultrahigh shear-mode electromechanical response. To exploit the low-frequency application of excellent shear-mode performance of the PMN-PT single crystal, we proposed a Shear-mode-based CANtilever Driving Low-frequency Energy harvester. The device is composed of two symmetrically assembled sandwich structures and a cantilever, in which sandwich structures can be driven by the cantilever. An analytical method was used to illustrate the high output mechanism, and a finite-element method model of the device was also established to optimize the generated electric energy in this device. The electrical properties of the device under different excitation frequencies and load resistances were studied systematically. The maximum voltage and power density at resonance frequency (43.8 Hz) were measured to be 60.8 V and 10.8 mW/cm(3) under a proof mass of 13.5 g, respectively. Both theoretical and experimental results demonstrate the considerable potential of the resonance-excited shear-mode energy harvester applied to wireless sensors and low-power portable electronics.

  15. Piezoelectric Polymers

    NASA Technical Reports Server (NTRS)

    Harrison, J. S.; Ounaies, Z.; Bushnell, Dennis M. (Technical Monitor)

    2001-01-01

    The purpose of this review is to detail the current theoretical understanding of the origin of piezoelectric and ferroelectric phenomena in polymers; to present the state-of-the-art in piezoelectric polymers and emerging material systems that exhibit promising properties; and to discuss key characterization methods, fundamental modeling approaches, and applications of piezoelectric polymers. Piezoelectric polymers have been known to exist for more than forty years, but in recent years they have gained notoriety as a valuable class of smart materials.

  16. Active Control of Radiated Sound With Integrated Piezoelectric Composite Structures. Volume 2 Appendices (Concl.)

    DTIC Science & Technology

    2007-11-02

    were calculated u.mg their perimnental dat and Leo.realt=a calculations for bimorph actuators from the sme pi=oe!-ec’ic ceramics having the e dimensons...piezoelectric actuators to replace shak- rs obser toe sme ers and realize a more compact or "smart" structure. 3 radiate to the far field. One of the...Wk) (8) 9(k)=(ifrI(k) ifr 2(k) A ifrk(k)) (9) The cost function is constructed as the mean square error signal, i.e. = E[e2(k)] (10) Substituting

  17. Temperature dependent structures and properties of Bi0.5Na0.5TiO3-based lead free piezoelectric composite.

    PubMed

    Zhang, Ji; Sun, Lei; Geng, Xiao-Yu; Zhang, Bin-Bin; Yuan, Guo-Liang; Zhang, Shan-Tao

    2016-07-05

    The thermal depolarization around 100 °C of the Bi0.5Na0.5TiO3-based piezoelectric solid solutions leads to the disappearance of macroscopic ferroelectric/piezoelectric properties and remains a long-standing obstacle for their actual applications. In this communication, we report lead-free piezoelectric composites of 0.94Bi0.5Na0.5TiO3-0.06BaTiO3:0.5ZnO (BNT-6BT:0.5ZnO, where 0.5 is the mole ratio of ZnO to BNT-6BT) with deferred thermal depolarization, which is experimentally confirmed by systematic temperature dependent dielectric, ferroelectric, piezoelectric measurements. Especially, based on temperature dependent X-ray diffraction measurements on unpoled and poled samples, thermal depolarization is confirmed to have no relationship with the structural phase transition, the possible mechanism for the deferred thermal depolarization is correlated with the ZnO-induced local electric field which can suppress the depolarization field. We believe our results may be helpful for understanding the origin of thermal depolarization in BNT-based piezoelectric materials, and thus provide an effective way to overcoming this obstacle.

  18. Elastic and Piezoelectric Properties of Boron Nitride Nanotube Composites. Part II; Finite Element Model

    NASA Technical Reports Server (NTRS)

    Kim, H. Alicia; Hardie, Robert; Yamakov, Vesselin; Park, Cheol

    2015-01-01

    This paper is the second part of a two-part series where the first part presents a molecular dynamics model of a single Boron Nitride Nanotube (BNNT) and this paper scales up to multiple BNNTs in a polymer matrix. This paper presents finite element (FE) models to investigate the effective elastic and piezoelectric properties of (BNNT) nanocomposites. The nanocomposites studied in this paper are thin films of polymer matrix with aligned co-planar BNNTs. The FE modelling approach provides a computationally efficient way to gain an understanding of the material properties. We examine several FE models to identify the most suitable models and investigate the effective properties with respect to the BNNT volume fraction and the number of nanotube walls. The FE models are constructed to represent aligned and randomly distributed BNNTs in a matrix of resin using 2D and 3D hollow and 3D filled cylinders. The homogenisation approach is employed to determine the overall elastic and piezoelectric constants for a range of volume fractions. These models are compared with an analytical model based on Mori-Tanaka formulation suitable for finite length cylindrical inclusions. The model applies to primarily single-wall BNNTs but is also extended to multi-wall BNNTs, for which preliminary results will be presented. Results from the Part 1 of this series can help to establish a constitutive relationship for input into the finite element model to enable the modeling of multiple BNNTs in a polymer matrix.

  19. Piezoelectric valve

    SciTech Connect

    Petrenko, Serhiy Fedorovich

    2013-01-15

    A motorized valve has a housing having an inlet and an outlet to be connected to a pipeline, a saddle connected with the housing, a turn plug having a rod, the turn plug cooperating with the saddle, and a drive for turning the valve body and formed as a piezoelectric drive, the piezoelectric drive including a piezoelectric generator of radially directed standing acoustic waves, which is connected with the housing and is connectable with a pulse current source, and a rotor operatively connected with the piezoelectric generator and kinematically connected with the rod of the turn plug so as to turn the turn plug when the rotor is actuated by the piezoelectric generator.

  20. Optimal Topology and Experimental Evaluation of Piezoelectric Materials for Actively Shunted General Electric Polymer Matrix Fiber Composite Blades

    NASA Technical Reports Server (NTRS)

    Choi, Benjamin B.; Duffy, Kirsten; Kauffman, Jeffrey L.; Kray, Nicholas

    2012-01-01

    NASA Glenn Research Center, in collaboration with GE Aviation, has begun the development of a smart adaptive structure system with piezoelectric (PE) transducers to improve composite fan blade damping at resonances. Traditional resonant damping approaches may not be realistic for rotating frame applications such as engine blades. The limited space in which the blades reside in the engine makes it impossible to accommodate the circuit size required to implement passive resonant damping. Thus, a novel digital shunt scheme has been developed to replace the conventional electric passive shunt circuits. The digital shunt dissipates strain energy through the load resistor on a power amplifier. General Electric (GE) designed and fabricated a variety of polymer matrix fiber composite (PMFC) test specimens. Investigating the optimal topology of PE sensors and actuators for each test specimen has revealed the best PE transducer location for each target mode. Also a variety of flexible patches, which can conform to the blade surface, have been tested to identify the best performing PE patch. The active damping control achieved significant performance at target modes. This work has been highlighted by successful spin testing up to 5000 rpm of subscale GEnx composite blades in Glenn s Dynamic Spin Rig.

  1. Colossal low-frequency resonant magnetomechanical and magnetoelectric effects in a three-phase ferromagnetic/elastic/piezoelectric composite

    NASA Astrophysics Data System (ADS)

    Liu, Guoxi; Li, Xiaotian; Chen, Jianguo; Shi, Huaduo; Xiao, Wenlei; Dong, Shuxiang

    2012-10-01

    Colossal low-frequency resonant magnetomechanical (MM) and magnetoelectric (ME) coupling effects have been found in a three-phase composite made of Pb(Zr,Ti)O3 ceramic fibers/phosphor copper-sheet unimorph and NdFeB magnets. The experimental results revealed that the ferromagnetic/elastic/piezoelectric three-phase composite with a cantilever beam structure could show huge bending MM coefficient of ˜145.9 × 10-3/Oe (unit in bending radian per Oe) and ME voltage coefficient of ˜16 000 V/cm.Oe at the first-order bending resonance frequency of ˜5 Hz. The achieved results related to ME effect are at least one order of magnitude higher over those of other ME materials and devices reported ever. The extremely strong MM and ME couplings in the three-phase composite are due to strong magnetic force moment effect induced by the interaction between NdFeB magnets and the applied magnetic field, and further resonant enhancement via the strain-mediated phosphor copper-sheet with a relatively high mechanical quality factor.

  2. Active constrained layer damping of geometrically nonlinear vibrations of functionally graded plates using piezoelectric fiber-reinforced composites

    NASA Astrophysics Data System (ADS)

    Panda, Satyajit; Ray, M. C.

    2008-04-01

    In this paper, a geometrically nonlinear dynamic analysis has been presented for functionally graded (FG) plates integrated with a patch of active constrained layer damping (ACLD) treatment and subjected to a temperature field. The constraining layer of the ACLD treatment is considered to be made of the piezoelectric fiber-reinforced composite (PFRC) material. The temperature field is assumed to be spatially uniform over the substrate plate surfaces and varied through the thickness of the host FG plates. The temperature-dependent material properties of the FG substrate plates are assumed to be graded in the thickness direction of the plates according to a power-law distribution while the Poisson's ratio is assumed to be a constant over the domain of the plate. The constrained viscoelastic layer of the ACLD treatment is modeled using the Golla-Hughes-McTavish (GHM) method. Based on the first-order shear deformation theory, a three-dimensional finite element model has been developed to model the open-loop and closed-loop nonlinear dynamics of the overall FG substrate plates under the thermal environment. The analysis suggests the potential use of the ACLD treatment with its constraining layer made of the PFRC material for active control of geometrically nonlinear vibrations of FG plates in the absence or the presence of the temperature gradient across the thickness of the plates. It is found that the ACLD treatment is more effective in controlling the geometrically nonlinear vibrations of FG plates than in controlling their linear vibrations. The analysis also reveals that the ACLD patch is more effective for controlling the nonlinear vibrations of FG plates when it is attached to the softest surface of the FG plates than when it is bonded to the stiffest surface of the plates. The effect of piezoelectric fiber orientation in the active constraining PFRC layer on the damping characteristics of the overall FG plates is also discussed.

  3. On the Binding Stress-Enhanced Sensitivity of (Pb(Mg1/3Nb2/3)O3)0.65-(PbTiO3) 0.35 (PMN-PT) Piezoelectric Plate Sensor (PEPS)

    NASA Astrophysics Data System (ADS)

    Wu, Wei

    (Pb(Mg1/3Nb2/3)O3)0.65-(PbTiO 3)0.35 (PMN-PT) piezoelectric plate sensor (PEPS) showed enhanced sensitivity in chemical and biological sensing applications which has been attributed to binding-induced crystalline orientation switching in the PMN-PT layer. However, so far there has been no direct demonstration of PEPS crystalline orientation switching upon target-analyte binding. Using biotin and streptavidin binding as a model detection system and by direct X-Ray diffraction observations after analyte binding we have unambiguously demonstrated that switching of the crystalline orientations of the PMN-PT layer indeed occurred. In addition, we have shown that PEPS sensitivity enhancement increased with an increasing transverse electromechanical coupling constant, -k31, of the PMN-PT layer--which is known to correlate with the crystalline orientation switching capability--by increasing the grain size of the PMN-PT layer or by applying a DC bias electric field. Finally, unprecedented high sensitivity of PEPS with high -k31, (i.e., -k31 > 0.3) were illustrated by the aM (10-18 M) sensitivity of in situ DNA hybridization detection without amplification and by the 100 fg/ml (10-13 g/ml) sensitivity of rapid, in situ protein detection in biological fluids such as troponin I detection in serum for early sign of myocardial infarction (heart attack), Her2 detection in serum for cancer treatment and monitoring, Tn antigen and anti-Tn antibody detection in serum for early cancer detection, and Toxins detection in stool for Clostridium difficile infection detection.

  4. Theoretical and experimental investigation of magnetoelectric effect for bending-tension coupled modes in magnetostrictive-piezoelectric layered composites

    NASA Astrophysics Data System (ADS)

    Hasanyan, D.; Gao, J.; Wang, Y.; Viswan, R.; Li, M.; Shen, Y.; Li, J.; Viehland, D.

    2012-07-01

    In this paper, we discuss a theoretical model with experimental verification for the resonance enhancement of magnetoelectric (ME) interactions at frequencies corresponding to bending-tension oscillations. A dynamic theory of arbitrary laminated magneto-elasto-electric bars was constructed. The model included bending and longitudinal vibration effects for predicting ME coefficients in laminate bar composite structures consisting of magnetostrictive, piezoelectric, and pure elastic layers. The thickness dependence of stress, strain, and magnetic and electric fields within a sample are taken into account, as such the bending deformations should be considered in an applied magnetic or electric field. The frequency dependence of the ME voltage coefficients has obtained by solving electrostatic, magnetostatic, and elastodynamic equations. We consider boundary conditions corresponding to free vibrations at both ends. As a demonstration, our theory for multilayer ME composites was then applied to ferromagnetic-ferroelectric bilayers, specifically Metglas-PZT ones. A theoretical model is presented for static (low-frequency) ME effects in such bilayers. We also performed experiments for these Metglas-PZT bilayers and analyzed the influence of Metglas geometry (length and thickness) and Metglas/PZT volume fraction on the ME coefficient. The frequency dependence of the ME coefficient is also presented for different geometries (length, thickness) of Metglas. The theory shows good agreement with experimental data, even near the resonance frequency.

  5. Stretchable piezoelectric nanocomposite generator.

    PubMed

    Park, Kwi-Il; Jeong, Chang Kyu; Kim, Na Kyung; Lee, Keon Jae

    2016-01-01

    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.

  6. Stretchable piezoelectric nanocomposite generator

    NASA Astrophysics Data System (ADS)

    Park, Kwi-Il; Jeong, Chang Kyu; Kim, Na Kyung; Lee, Keon Jae

    2016-06-01

    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.

  7. Piezoelectric materials used in underwater acoustic transducers

    SciTech Connect

    Li, Huidong; Deng, Zhiqun; Carlson, Thomas J.

    2012-07-07

    Piezoelectric materials have been used in underwater acoustic transducers for nearly a century. In this paper, we reviewed four different types of piezoelectric materials: piezoelectric ceramics, single crystals, composites, and polymers, which are widely used in underwater acoustic transducers nowadays. Piezoelectric ceramics are the most dominant material type and are used as a single-phase material or one of the end members in composites. Piezoelectric single crystals offer outstanding electromechanical response but are limited by their manufacturing cost. Piezoelectric polymers provide excellent acoustic impedance matching and transducer fabrication flexibility although their piezoelectric properties are not as good as ceramics and single crystals. Composites combined the merits of ceramics and polymers and are receiving increased attention. The typical structure and electromechanical properties of each type of materials are introduced and discussed with respect to underwater acoustic transducer applications. Their advantages and disadvantages are summarized. Some of the critical design considerations when developing underwater acoustic transducers with these materials are also touched upon.

  8. Coupled domain wall motion, lattice strain and phase transformation in morphotropic phase boundary composition of PbTiO3-BiScO3 piezoelectric ceramic

    DOE PAGES

    Khatua, Dipak Kumar; V., Lalitha K.; Fancher, Chris M.; ...

    2016-10-18

    High energy synchrotron X-ray diffraction, in situ with electric field, was carried out on the morphotropic phase boundary composition of the piezoelectric alloy PbTiO3-BiScO3. We demonstrate a strong correlation between ferroelectric-ferroelastic domain reorientation, lattice strain and phase transformation. Lastly, we also show the occurrence of the three phenomena and persistence of their correlation in the weak field regime.

  9. Structural Diagnostics of CFRP Composite Aircraft Components by Ultrasonic Guided Waves and Built-In Piezoelectric Transducers

    SciTech Connect

    Matt, Howard M.

    2006-01-01

    To monitor in-flight damage and reduce life-cycle costs associated with CFRP composite aircraft, an autonomous built-in structural health monitoring (SHM) system is preferred over conventional maintenance routines and schedules. This thesis investigates the use of ultrasonic guided waves and piezoelectric transducers for the identification and localization of damage/defects occurring within critical components of CFRP composite aircraft wings, mainly the wing skin-to-spar joints. The guided wave approach for structural diagnostics was demonstrated by the dual application of active and passive monitoring techniques. For active interrogation, the guided wave propagation problem was initially studied numerically by a semi-analytical finite element method, which accounts for viscoelastic damping, in order to identify ideal mode-frequency combinations sensitive to damage occurring within CFRP bonded joints. Active guided wave tests across three representative wing skin-to-spar joints at ambient temperature were then conducted using attached Macro Fiber Composite (MFC) transducers. Results from these experiments demonstrate the importance of intelligent feature extraction for improving the sensitivity to damage. To address the widely neglected effects of temperature on guided wave base damage identification, analytical and experimental analyses were performed to characterize the influence of temperature on guided wave signal features. In addition, statistically-robust detection of simulated damage in a CFRP bonded joint was successfully achieved under changing temperature conditions through a dimensionally-low, multivariate statistical outlier analysis. The response of piezoceramic patches and MFC transducers to ultrasonic Rayleigh and Lamb wave fields was analytically derived and experimentally validated. This theory is useful for designing sensors which possess optimal sensitivity toward a given mode-frequency combination or for predicting the frequency dependent

  10. Ultrasonics transduction in metallic and composite structures for structural health monitoring using extensional and shear horizontal piezoelectric wafer active sensors

    NASA Astrophysics Data System (ADS)

    Abdelrahman, Ayman Kamal

    Structural health monitoring (SHM) is crucial for monitoring structures performance, detecting the initiation of flaws and damages, and predicting structural life span. The dissertation emphasizes on developing analytical and numerical models for ultrasonics transduction between piezoelectric wafer active sensors (PWAS), and metallic and composite structures. The first objective of this research is studying the power and energy transduction between PWAS and structure for the aim of optimizing guided waves mode tuning and PWAS electromechanical (E/M) impedance for power-efficient SHM systems. Analytical models for power and energy were developed based on exact Lamb wave solution with application on multimodal Lamb wave situations that exist at high excitation frequencies and/or relatively thick structures. Experimental validation was conducted using Scanning Laser Doppler Vibrometer. The second objective of this work focuses on shear horizontal (SH) PWAS which are poled in thickness-shear direction (d35 mode). Analytical and finite element predictive models of the E/M impedance of free and bonded SH-PWAS were developed. Next, the wave propagation method has been considered for isotropic materials. Finally, the power and energy of SH waves were analytically modeled and a MATLAB graphical user interface (GUI) was developed for determining phase and group velocities, mode shapes, and energy of SH waves. The third objective focuses on guided wave propagation in composites. The transfer matrix method (TMM) has been used to calculate dispersion curves of guided waves in composites. TMM suffers numerical instability at high frequency-thickness values, especially in multilayered composites. A method of using stiffness matrix method was investigated to overcome instability. A procedure of using combined stiffness transfer matrix method (STMM) was presented and coded in MATLAB. This was followed by a comparative study between commonly used methods for the calculation of

  11. Design of Low-Loss 1–3 Piezoelectric Composites for High-Power Transducer Applications

    PubMed Central

    Lee, Hyeong Jae; Zhang, Shujun

    2013-01-01

    Lead zirconate titanate (PZT)/polymer 1–3 composites have improved electromechanical properties compared with monolithic counterparts, but possess a low mechanical quality factor, limiting their use in high-power transducer applications. The goal of this work was to improve the mechanical quality factor of 1–3 PZT/polymer composites by optimizing the polymer materials. Theoretical analysis and modeling were performed for optimum composite design and various polymers were prepared and characterized. 1–3 piezocomposites were constructed and their electromechanical properties were experimentally determined. The results demonstrated that the composites with high-thermal-conductivity polymers generally have degraded electromechanical properties with significantly decreased mechanical quality factors, whereas the composites filled with low-loss and low-moduli polymers were found to have higher mechanical quality factors with higher electrome-chanical coupling factors: Qm ~ 200 and kt ~ 0.68 for PZT4 composites; Qm ~ 400 and kt ~ 0.6 for PZT8 composites. The improved mechanical quality factor of 1–3 piezocomposites may offer improved performance and thermal stability of transducers under high-drive operation. PMID:23007769

  12. Detection and monitoring of axial cracks on cylindrical structures using torsional wave generated by piezoelectric macro-fiber composite

    NASA Astrophysics Data System (ADS)

    Cui, Lin; Lim, Say Ian; Shi, Miao; Liu, Yu; Soh, Chee Kiong

    2012-04-01

    In cylindrical structures such as pipelines and pressure vessels, cracks are most likely to occur along the longitudinal (axial) direction and they can be fatal to the serviceability of the structures. Unfortunately, the conventional ultrasonic crack detection techniques, which usually use longitudinal wave, are not very sensitive to this type of cracks. This paper focuses on the detection and monitoring of axial cracks in cylindrical structures using torsional wave generated by piezoelectric macro-fiber composite (MFC). The first order torsional wave is a kind of non-dispersive pure shear wave which propagates at a fixed wave speed. Torsional wave is utilized in this work because, intuitively, it is more sensitive to axial cracks than the family of longitudinal waves. Numerical simulation has been performed using ANSYS to show the effectiveness of torsional wave in detecting and monitoring axial cracks. The time of flight (TOF) of the waves is used to determine the crack position, while the crack propagation is monitored by measuring the variation in the crack induced disturbances. Experiments have also been conducted to investigate the feasibility of the proposed method. MFC transducers oriented at 45° against the axis of the specimen are used to generate and receive torsional waves. The experimental results demonstrated that the crack position can be indentified and its growth can be well monitored with the presented approach using torsional wave.

  13. Effect of Embedded Piezoelectric Sensors on Fracture Toughness and Fatigue Resistance of Composite Laminates Under Mode I Loading

    NASA Technical Reports Server (NTRS)

    Murri, Gretchen B.

    2006-01-01

    Double-cantilevered beam (DCB) specimens of a glass/epoxy composite material with embedded piezoelectric sensors were tested both statically and under fatigue loading to determine the effect of the embedded material on the Mode I fracture toughness and fatigue resistance compared to baseline data without the embedded elements. A material known as LaRC-Macrofiber Composite (LaRC-MFC (TradeMark)), or MFC, was embedded at the midplane of the specimen during the layup. Specimens were manufactured with the embedded MFC material either at the loaded end of the specimen to simulate an initial delamination; or with the MFC material located at the delaminating interface, with a Teflon film at the loaded end to simulate an initial delamination. There were three types of specimens with the embedded material at the delaminating interface: co-cured with no added adhesive; cured with a paste adhesive applied to the embedded element; or cured with a film adhesive added to the embedded material. Tests were conducted with the sensors in both the passive and active states. Results were compared to baseline data for the same material without embedded elements. Interlaminar fracture toughness values (G(sub Ic)) for the passive condition showed little change when the MFC was at the insert end. Passive results varied when the MFC was at the delaminating interface. For the co-cured case and with the paste adhesive, G(sub Ic) decreased compared to the baseline toughness, whereas, for the film adhesive case, G(sub Ic) was significantly greater than the baseline toughness, but the failure was always catastrophic. When the MFC was in the active state, G(sub Ic) was generally lower compared to the passive results. Fatigue tests showed little effect of the embedded material whether it was active or passive compared to baseline values.

  14. Structure modification of 0 3 piezoelectric ceramic/polymer composites through dielectrophoresis

    NASA Astrophysics Data System (ADS)

    Wilson, S. A.; Maistros, G. M.; Whatmore, R. W.

    2005-01-01

    Anisotropic material properties can be induced in ceramic/polymer composites by applying an alternating electric field of moderate strength during processing. Under suitable conditions, particles of a ceramic filler material that are randomly dispersed in a liquid polymer or pre-polymer can be polarized and they then exhibit a collective response to localized gradients in the electric field. Typically, the particles experience a mutually attractive force which causes them to form 'pearl-chains' or columnar structures spanning the gap between electrodes. If the fluid is solidified, for example by curing the polymer resin, then the newly formed structures can be fixed in place to produce a composite with directional electrical and mechanical properties. Direct visual observations were made for low volume fraction dispersions of pure lead titanate in an epoxy pre-polymer under the influence of an electric field. The observed interaction was correlated with low-field dielectric measurements and existing theory to identify optimum assembly conditions. The dielectric properties of the fluid are predominant and the formation of chain-like structures is found to be both field strength and field frequency dependent. The dielectric permittivities of a range of structurally modified composites were measured and compared with existing theoretical models of di-phasic materials.

  15. Piezoelectric Film.

    ERIC Educational Resources Information Center

    Garrison, Steve

    1992-01-01

    Presents activities that utilize piezoelectric film to familiarize students with fundamental principles of electricity. Describes classroom projects involving chemical sensors, microbalances, microphones, switches, infrared sensors, and power generation. (MDH)

  16. Giant self-biased magnetoelectric response with obvious hysteresis in layered homogeneous composites of negative magnetostrictive material Samfenol and piezoelectric ceramics

    NASA Astrophysics Data System (ADS)

    Zhang, Jitao; Li, Ping; Wen, Yumei; He, Wei; Yang, Aichao; Lu, Caijiang

    2013-11-01

    Giant self-biased magnetoelectric (ME) response and obvious hysteresis are observed in trilayer homogenous ME laminate composite consisting of negative magnetostrictive Samfenol (SmFe2) plates and piezoelectric ceramic PZT (Pb(Zr,Ti)O3) plates. The large anisotropic field of SmFe2 oriented the direction [111] of easy magnetization results in an enhanced internal bias due to its huge intrinsic anisotropic constant. The experimental results demonstrate that this composite exhibits ˜30 times higher ME voltage coefficient than that of composite FeNi/PZT/FeNi with weak ME coupling at zero bias. These results provide the possibility of this homogeneous ME composite for ultra-sensitive magnetic field sensing without bias.

  17. Enhancing the bandwidth of piezoelectric composite transducers for air-coupled non-destructive evaluation.

    PubMed

    Banks, Robert; O'Leary, Richard L; Hayward, Gordon

    2017-03-01

    This paper details the development of a novel method for increasing the operational bandwidth of piezocomposites without the need for lossy backing material, the aim being to increase fractional bandwith by geometrical design. Removing the need for lossy backing materials, should in turn increase the transmit efficiency in the desired direction of propagation. Finite element analysis has been employed to determine the mode of operation of the new piezocomposite devices and shows good correlation with that derived experimentally. Through a series of practical and analytical methods it has been shown that additional thickness mode resonances can be introduced into the structure by a simple machining process. The shaped composites described in this paper offer increased operational bandwidth. A simple example of a two step thickness design is described to validate and illustrate the principle. A more complex conical design is presented that illustrates a possible tenfold increase in bandwidth from 30kHz to 300kHz, operating in air without backing. An illustration of the applicability of this type of transducer technology for frequency agile guided mode non-destructive evaluation is then presented.

  18. Electroacoustic response of 1-3 piezocomposite transducers for high power applications

    NASA Astrophysics Data System (ADS)

    Jae Lee, Hyeong; Zhang, Shujun; Geng, Xuecang; Shrout, Thomas R.

    2012-12-01

    The electroacoustic performance of 1-3 piezoelectric composite transducers with low loss polymer filler was studied and compared to monolithic Pb(Zr,Ti)O3 (PZT) piezoelectric transducers. The 1-3 composite transducers exhibited significantly high electromechanical coupling factor (kt ˜ 0.64) when compared to monolithic counterparts (kt ˜ 0.5), leading to the improved bandwidth and loop sensitivity, being on the order of 67% and -24.0 dB versus 44% and -24.8 dB, respectively. In addition, the acoustic output power and transmit efficiency (˜50%) were found to be comparable to the monolithic PZT transducers, demonstrating potential for broad bandwidth, high power ultrasonic transducer applications.

  19. Simultaneous precision positioning and vibration suppression of an intelligent composite satellite structure utilizing piezoelectric sensors and actuators

    NASA Astrophysics Data System (ADS)

    Doherty, Kathleen Marie

    Adaptive or intelligent structures which have the capability for sensing and responding to their environment promise a novel approach to satisfying the stringent performance requirements of future space missions. This research effort focuses on the development of a smart thruster mount truss structure with precision positioning and active vibration suppression capability for use in a space satellite. The smart thruster mount would utilize piezoelectric sensors and actuators for precision positioning to provide fine tuning of position tolerance for thruster alignment. The same structure may be used for suppressing the vibration that resonates throughout the spacecraft during thruster firing. This vibration renders sensitive optical or measurement equipment non-operational until the disturbance has dissipated. This smart system approach would greatly enhance mission performance by fine tuning attitude control, potentially eliminating the nonoperational period as well as minimizing fuel consumption utilized for position correction. The configuration of the smart thruster mount truss system is that of a modified Stewart platform. Precision positioning of the truss structure is achieved using active members which extend or contract to tilt the upper platform where the thruster is mounted. An inverse kinematic analysis of a modified Stewart platform has been developed and is used to determine the required axial displacement of the active struts for the desired angular tilt of the smart platform. Experimental data is used to verify the precision positioning capabilities of the active struts. This information demonstrates the ability of the active strut to tilt the top of the smart platform by the required angular displacement. Analytical verification of the vibration suppression capabilities of the active struts in the smart composite platform using finite element analysis is presented. A model of an active strut with surface mounted sensors/actuators was used to develop

  20. Piezoelectric transducer

    NASA Technical Reports Server (NTRS)

    Conragan, J.; Muller, R. S.

    1970-01-01

    Transducer consists of a hybrid thin film and a piezoelectric transistor that acts as a stress-sensitive device with built-in gain. It provides a stress/strain transducer that incorporates a signal amplification stage and sensor in a single package.

  1. Symmetry of piezoelectric (1–x)Pb(Mg1/3Nb2/3)O₃-xPbTiO₃ (x=0.31) single crystal at different length scales in the morphotropic phase boundary region

    DOE PAGES

    Kim, Kyou-Hyun; Payne, David A.; Zuo, Jian-Min

    2012-11-29

    We use probes of three different length scales to examine symmetry of (1–x)Pb(Mg1/3Nb2/3)O₃-xPbTiO₃ (PMN-xPT) single crystals in the morphotropic phase boundary (MPB) region at composition x = 0.31 (PMN-31% PT). On the macroscopic scale, x-ray diffraction (XRD) shows a mixture of strong and weak diffraction peaks of different widths. The closest match to XRD peak data is made with monoclinic Pm (MC) symmetry. On the local scale of a few nanometers, convergent beam electron diffraction (CBED) studies, with a 1.6-nm electron probe, reveal no obvious symmetry. These CBED experimental patterns can be approximately matched with simulations based on monoclinic symmetry,more » which suggests locally distorted monoclinic structure. A monoclinic Cm (MA or MB)-like symmetry could also be obtained from certain regions of the crystal by using a larger electron probe size of several tens of nanometers in diameter. Thus the monoclinic symmetry of single crystal PMN-31%PT is developed only in parts of the crystal by averaging over locally distorted structure on the scale of few tens of nanometers. The macroscopic symmetry observed by XRD is a result of averaging from the local structure in PMN-31%PT single crystal. The lack of local symmetry at a few nanometers scale suggests that the polarization switching results from a change in local displacements, which are not restricted to specific symmetry planes or directions.« less

  2. Band gaps of lamb waves in one-dimensional piezoelectric composite plates: effect of substrate and boundary conditions.

    PubMed

    Zou, Xin-Ye; Liang, Bin; Chen, Qian; Cheng, Jian-Chun

    2009-02-01

    We theoretically study the band structures of Lamb waves in one-dimensional phononic crystal plates consisting of piezoelectric ceramics placed periodically in epoxy with epoxy or piezoelectric ceramic substrate by the virtual plane wave expansion method. The dependences of the widths and starting frequencies of first band gaps (FBG) on the substrate's thickness, the filling fraction, and the lattice spacing are calculated for different materials of substrate under different electric boundary conditions, i.e., short circuit (SC) and open circuit (OC). The FBG width decreases gradually as the substrate's thickness increases and the FBG starting frequency increases progressively as the thickness increases on the whole. The FBG widths and starting frequencies with SC are always larger than with OC. Our research shows that it is possible to control the width and starting frequency of the FBG in the engineering according to need by choosing suitable values of the substrate's thickness, the filling fraction, and the lattice spacing.

  3. A Dynamic Analysis of Piezoelectric Strained Elements.

    DTIC Science & Technology

    1992-12-01

    of Piezoelectricity , Oxford Univ.Press, Oxford (1990). E38] T.C.Ting, "Dynamic response of composites", Appl. Mechs.Rev., vol. 33, no.12, Dp.1629-16...Plenum Press, New York (1969). 276 [36] J.Zelenka, Piezoelectric Resonators and their Applications, Elsevier, Amsterdam (1986). [37] T.Ikeda, Fundamentals

  4. Piezoelectric and electrostrictive materials for transducer applications

    NASA Astrophysics Data System (ADS)

    Cross, L. E.; Newnham, R. E.; Barsch, G. R.; Biggers, J. V.

    1985-05-01

    This report covers work accomplished on the second year of contract No. N00014-82-K0339 for the study of Piezoelectric and Electrostrictive Materials for Transducer Applications. The work accomplished covers a rather wide range of topics and for convenience, it is divided into four major sub-topics: (1) composite materials, (2) electrostriction, (3) conventional piezoelectrics, and (4) preparative studies.

  5. LC Circuits for Diagnosing Embedded Piezoelectric Devices

    NASA Technical Reports Server (NTRS)

    Chattin, Richard L.; Fox, Robert Lee; Moses, Robert W.; Shams, Qamar A.

    2005-01-01

    A recently invented method of nonintrusively detecting faults in piezoelectric devices involves measurement of the resonance frequencies of inductor capacitor (LC) resonant circuits. The method is intended especially to enable diagnosis of piezoelectric sensors, actuators, and sensor/actuators that are embedded in structures and/or are components of multilayer composite material structures.

  6. Creation of hierarchical carbon nanotube assemblies through alternative packing of complementary semi-artificial beta-1,3-glucan/carbon nanotube composites.

    PubMed

    Numata, Munenori; Sugikawa, Kouta; Kaneko, Kenji; Shinkai, Seiji

    2008-01-01

    Much attention has been focused on exploiting novel strategies for the creation of hierarchical polymer assemblies by the control of the assembling number or the relative location among neighboring polymers. We here propose a novel strategy toward the creation of "hierarchical" single-walled carbon nanotube (SWNT) architectures by utilizing SWNT composites with cationic or anionic complementary semi-artificial beta-1,3-glucans as "building blocks". These beta-1,3-glucans are known to wrap SWNTs helically, to create one-dimensional superstructural composites. If the cationic composite is neutralized by an anionic composite, a well ordered SWNT-based sheet structure was created. Transmission electron microscopy (TEM) observation revealed that this sheet structure is composed of highly-ordered fibrous assemblies of SWNTs. This suggests that the cationic and anionic composites are tightly packed through electrostatic interactions. Moreover, both of the final assembly structures are readily tunable by adjusting the cation/anion ratio. The self-assembling modulation of functional polymers is associated with the progress in ultimate nanotechnologies, thus enabling us to create numerous functional nanomaterials. We believe, therefore, that the present system will extend the frontier of SWNT research to assembly chemistry including "hierarchical" superstructures.

  7. Advanced piezoelectric single crystal based transducers for naval sonar applications

    NASA Astrophysics Data System (ADS)

    Snook, Kevin A.; Rehrig, Paul W.; Hackenberger, Wesley S.; Jiang, Xiaoning; Meyer, Richard J., Jr.; Markley, Douglas

    2006-03-01

    Transducers incorporating single crystal piezoelectric Pb(Mg 1/3Nb 2/3) x-1Ti xO 3 (PMN-PT) exhibit significant advantages over ceramic piezoelectrics such as PZT, including both high electromechanical coupling (k 33 > 90%) and piezoelectric coefficients (d 33 > 2000 pC/N). Conventional <001> orientation gives inherently larger bandwidth and output power than PZT ceramics, however, the anisotropy of the crystal also allows for tailoring of the performance by orienting the crystal along different crystallographic axes. This attribute combined with composition refinements can be used to improve thermal or mechanical stability, which is important in high power, high duty cycle sonar applications. By utilizing the "31" resonance mode, the high power performance of PMN-PT can be improved over traditional "33" mode single crystal transducers, due to an improved aspect ratio. Utilizing novel geometries, effective piezoelectric constants of -600 pC/N to -1200 pC/N have been measured. The phase transition point induced by temperature, pre-stress or field is close to that in the "33" mode, and since the prestress is applied perpendicular to the poling direction in "31" mode elements, they exhibit lower loss and can therefore be driven harder. The high power characteristics of tonpilz transducers can also be affected by the composition of the PMN-PT crystal. TRS modified the composition of PMN-PT to improve the thermal stability of the material, while keeping the loss as low as possible. Three dimensional modeling shows that the useable bandwidth of these novel compositions nearly equals that of conventional PMN-PT. A decrease in the source level of up to 6 dB was calculated, which can be compensated for by the higher drive voltages possible.

  8. International Conference Post Failure Analysis Techniques for Fiber Reinforced Composites Held in Dayton, Ohio on 1-3 July 1985

    DTIC Science & Technology

    1991-07-01

    W. Bradley, Texas A&M University, College Station, Texas "Some Fractographic Investigations of Compressive ..... . . . . lB-I Failures in Carbon Fibre...tension and compression of unidirectional n60% volume fraction glass and carbon fibre reinforced epoxy resin composites have been investigated at...operated by tensile and compressive stresses, eg in fibres, on the one hand, and by shear stresses, eg in matrices, on the other. The atmospheric tensile

  9. Effects of PbO-B2O3 Glass Doping on the Sintering Temperature and Piezoelectric Properties of 0.35Pb (Ni1/3Nb2/3)O3-0.65Pb(Zr0.41Ti0.59)O3 Ceramics

    NASA Astrophysics Data System (ADS)

    Yi, Jinqiao; Shen, Meng; Liu, Sisi; Jiang, Shenglin

    2015-12-01

    0.35Pb(Ni1/3Nb2/3)O3-0.65Pb(Zr0.41Ti0.59)O3 (PNN-PZT) ceramics doped with 0.5PbO-0.5B2O3 glass have been synthesized by the conventional solid-state sintering technique. The effects of 0.5PbO-0.5B2O3 glass on the sintering temperature and piezoelectric properties of PNN-PZT ceramics were studied. The results indicated that the sintering temperature of PNN-PZT was significantly reduced due to the incorporation of 0.5PbO-0.5B2O3 glass dopant. When the content of 0.5PbO-0.5B2O3 glass was 0.5 wt.%, the sintering temperature of PNN-PZT was observed to reduce from above 1200°C to 920°C while the samples maintained high density (7.91 g/cm3), excellent piezoelectric constant ( d 33 = 479 pC/N), large electromechanical coupling coefficient ( K p = 0.55), and relatively low electromechanical quality factor ( Q m = 79). Moreover, large dielectric constant ( ɛ 33 T / ɛ 0 = 2904) and low dielectric loss (tan δ = 0.0166) were obtained in this work.

  10. Piezoelectric stack transducer evaluation and comparison for optimized energy harvesting

    NASA Astrophysics Data System (ADS)

    Gamboa, Bryan

    Lead Zirconate Titanate (PZT) is the most prevalent piezoelectric material used around the world. These materials are used in a wide array of devices across a vast group of applications. The primary focus of this research is on the application and optimization of direct piezoelectric effect in energy harvesting from low frequency mechanical vibration. The specific research aim is at understanding the stacked PZT transducers in their mechanisms and performance on effective electromechanical energy conversion. Piezoelectric power output has been determined based on understanding of the fundamental concepts in composites (1:3 bi-phasic) and stack transducers. Several property structure relations are evaluated by various experimental methods including the utilization of electrodynamic test systems (Acumen III and the Universal Testing Machine 25, both by MTS Systems Corp.). The converted power is monitored and recorded using pc interfaced digital multimeter (Metrahit by Messtechnik GmbH). Power evaluation is compared among several samples in order to understand the most efficient configuration utilizing PZT ceramics. Impedance measurements, piezoelectric coefficients and permittivity calculations are evaluated to more accurately compare the samples. Power density as function of applied mechanical force and pressure, are calculated and compared with experimental results which yield good agreement. Three types of stack PZT transducers were compared and systemically tested for their electromechanical power conversion performance. While 1:3 composite stack PZT transducer was found to be the best performer in term of power density per active volume, the custom fabricated stack PZT transducers (UTSA stack sample) were found to have the highest power density per total transducer volume, 0.615 muW/mm3, measured at 965 kN/m2 (140 PSI), among the three types studied.

  11. Peak divergence in the curve of magnetoelectric coefficient versus dc bias magnetic field at resonance region for bi-layer magnetostrictive/piezoelectric composites

    SciTech Connect

    Zuo, Z. J.; Pan, D. A. Zhang, S. G.; Qiao, L. J.; Jia, Y. M.

    2013-12-15

    Magnetoelectric (ME) coefficient dependence on the bias magnetic field at resonance frequencies for the bi-layered bonded Terfenol-D/Pb(Zr,Ti)O{sub 3} composite was investigated. The resonance frequency decreases first and then increases with the bias magnetic field (H{sub DC}), showing a “V” shape in the range of 0 ∼ 5 kOe. Below the resonance frequency, the pattern of ME coefficient dependence on the H{sub DC} shows a single peak, but splits into a double-peak pattern when the testing frequency increases into a certain region. With increasing the frequency, a divergent evolution of the H{sub DC} patterns was observed. Domain motion and ΔE effect combined with magnetostriction-piezoelectric coupling effect were employed to explain this experimental result.

  12. Fabrication and performance of endoscopic ultrasound radial arrays based on PMN-PT single crystal/epoxy 1-3 composite.

    PubMed

    Zhou, Dan; Cheung, Kwok Fung; Chen, Yan; Lau, Sien Ting; Zhou, Qifa; Shung, K Kirk; Luo, Hao Su; Dai, Jiyan; Chan, Helen Lai Wa

    2011-02-01

    In this paper, 0.7Pb(Mg(¹/₃)Nb(²/₃)O₃-0.3PbTiO₃ (PMN-PT) single crystal/epoxy 1/3 composite was used as the active material of the endoscopic ultrasonic radial array transducer, because this composite exhibited ultrahigh electromechanical coupling coefficient (k(t) = 0.81%), very low mechanical quality factor (Q(m) = 11) and relatively low acoustic impedance (Z(t) = 12 MRayls). A 6.91 MHz PMN-PT/epoxy 1/3 composite radial array transducer with 64 elements was tested in a pulseecho response measurement. The -6-dB bandwidth of the composite array transducer was 102%, which was ~30% larger than that of traditional lead zirconate titanate array transducer. The two-way insertion loss was found to be -32.3 dB. The obtained results show that this broadband array transducer is promising for acquiring high-resolution endoscopic ultrasonic images in many clinical applications.

  13. Giant piezoelectricity on Si for hyperactive MEMS.

    PubMed

    Baek, S H; Park, J; Kim, D M; Aksyuk, V A; Das, R R; Bu, S D; Felker, D A; Lettieri, J; Vaithyanathan, V; Bharadwaja, S S N; Bassiri-Gharb, N; Chen, Y B; Sun, H P; Folkman, C M; Jang, H W; Kreft, D J; Streiffer, S K; Ramesh, R; Pan, X Q; Trolier-McKinstry, S; Schlom, D G; Rzchowski, M S; Blick, R H; Eom, C B

    2011-11-18

    Microelectromechanical systems (MEMS) incorporating active piezoelectric layers offer integrated actuation, sensing, and transduction. The broad implementation of such active MEMS has long been constrained by the inability to integrate materials with giant piezoelectric response, such as Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PMN-PT). We synthesized high-quality PMN-PT epitaxial thin films on vicinal (001) Si wafers with the use of an epitaxial (001) SrTiO(3) template layer with superior piezoelectric coefficients (e(31,f) = -27 ± 3 coulombs per square meter) and figures of merit for piezoelectric energy-harvesting systems. We have incorporated these heterostructures into microcantilevers that are actuated with extremely low drive voltage due to thin-film piezoelectric properties that rival bulk PMN-PT single crystals. These epitaxial heterostructures exhibit very large electromechanical coupling for ultrasound medical imaging, microfluidic control, mechanical sensing, and energy harvesting.

  14. Note: High-power piezoelectric transformer fabricated with ternary relaxor ferroelectric Pb(Mg(1/3)Nb(2/3))O3-Pb(In(1/2)Nb(1/2))O3-PbTiO3 single crystal.

    PubMed

    Wang, Qing; Ma, Chuanguo; Wang, Feifei; Liu, Bao; Chen, Jianwei; Luo, Haosu; Wang, Tao; Shi, Wangzhou

    2016-03-01

    A plate-shaped piezoelectric transformer was designed and fabricated using ternary relaxor ferroelectric single crystal Pb(Mg(1/3)Nb(2/3))O3-Pb(In(1/2)Nb(1/2))O3-PbTiO3. Both the input and output sections utilized the transverse-extensional vibration mode. The frequency and load dependences of the electrical properties for the proposed transformer were systematically studied. Results indicated that under a matching load resistance of 14.9 kΩ, a maximum output power of 2.56 W was obtained with the temperature rise less than 5 °C. The corresponding power density reached up to 50 W/cm(3). This ternary single-crystal transformer had potential applications in compact-size converters requiring high power density.

  15. Temperature dependence of dielectric, elastic, and piezoelectric constants of [001]c poled Mn-doped 0.24Pb(In1/2Nb1/2)O3-0.46Pb(Mg1/3Nb2/3)O3-0.30PbTiO3 single crystal

    PubMed Central

    Tian, Hua

    2016-01-01

    In order to simulate the performance of electromechanical devices at elevated temperatures, full tensor properties of piezoelectric materials at high temperatures are needed. Such data are extremely difficult to get for relaxor-based single crystals because their properties are determined by domain structures, which are strongly geometry dependent. We report here the temperature dependence of full tensor material constants of [001]c poled Mn-doped 0.24Pb(In1/2Nb1/2)O3-0.46Pb(Mg1/3Nb2/3)O3-0.30PbTiO3 single crystals from 25 °C to 55 °C, which were determined by the resonant ultrasound spectroscopy. Because only one sample was used, high degree of self-consistency was achieved for the tensor constants at all measured temperatures. PMID:26957649

  16. Note: High-power piezoelectric transformer fabricated with ternary relaxor ferroelectric Pb(Mg1/3Nb2/3)O3-Pb(In1/2Nb1/2)O3-PbTiO3 single crystal

    NASA Astrophysics Data System (ADS)

    Wang, Qing; Ma, Chuanguo; Wang, Feifei; Liu, Bao; Chen, Jianwei; Luo, Haosu; Wang, Tao; Shi, Wangzhou

    2016-03-01

    A plate-shaped piezoelectric transformer was designed and fabricated using ternary relaxor ferroelectric single crystal Pb(Mg1/3Nb2/3)O3-Pb(In1/2Nb1/2)O3-PbTiO3. Both the input and output sections utilized the transverse-extensional vibration mode. The frequency and load dependences of the electrical properties for the proposed transformer were systematically studied. Results indicated that under a matching load resistance of 14.9 kΩ, a maximum output power of 2.56 W was obtained with the temperature rise less than 5 °C. The corresponding power density reached up to 50 W/cm3. This ternary single-crystal transformer had potential applications in compact-size converters requiring high power density.

  17. Broadband and High Sensitive Time-of-Flight Diffraction Ultrasonic Transducers Based on PMNT/Epoxy 1–3 Piezoelectric Composite

    PubMed Central

    Liu, Dongxu; Yue, Qingwen; Deng, Ji; Lin, Di; Li, Xiaobing; Di, Wenning; Wang, Xi’an; Zhao, Xiangyong; Luo, Haosu

    2015-01-01

    5–6 MHz PMNT/epoxy 1–3 composites were prepared by a modified dice-and-fill method. They exhibit excellent properties for ultrasonic transducer applications, such as ultrahigh thickness electromechanical coupling coefficient kt (85.7%), large piezoelectric coefficient d33 (1209 pC/N), and relatively low acoustic impedance Z (1.82 × 107 kg/(m2·s)). Besides, two types of Time-of-Flight Diffraction (TOFD) ultrasonic transducers have been designed, fabricated, and characterized, which have different matching layer schemes with the acoustic impedance of 4.8 and 5.7 × 106 kg/(m2·s), respectively. In the detection on a backwall of 12.7 mm polystyrene, the former exhibits higher detectivity, the relative pulse-echo sensitivity and −6 dB relative bandwidth are −21.93 dB and 102.7%, respectively, while the later exhibits broader bandwidth, the relative pulse-echo sensitivity and −6 dB relative bandwidth are −24.08 dB and 117.3%, respectively. These TOFD ultrasonic transducers based on PMNT/epoxy 1–3 composite exhibit considerably improved performance over the commercial PZT/epoxy 1–3 composite TOFD ultrasonic transducer. PMID:25808776

  18. Semi-active control of piezoelectric coating's underwater sound absorption by combining design of the shunt impedances

    NASA Astrophysics Data System (ADS)

    Sun, Yang; Li, Zhaohui; Huang, Aigen; Li, Qihu

    2015-10-01

    Piezoelectric shunt damping technology has been applied in the field of underwater sound absorption in recent years. In order to achieve broadband echo reduction, semi-active control of sound absorption of multi-layered piezoelectric coating by shunt damping is significant. In this paper, a practical method is proposed to control the underwater sound absorption coefficients of piezoelectric coating layers by combining design of the shunt impedance that allows certain sound absorption coefficients at setting frequencies. A one-dimensional electro-acoustic model of the piezoelectric coating and the backing is established based on the Mason equivalent circuit theory. First, the shunt impedance of the coating is derived under the constraint of sound absorption coefficient at one frequency. Then, taking the 1-3 piezoelectric composite coating as an example, the sound absorption properties of the coating shunted to the designed shunt impedance are investigated. Next, on the basis of that, an iterative method for two constrained frequencies and an optimizing algorithm for multiple constrained frequencies are provided for combining design of the shunt impedances. At last, an experimental sample with four piezoelectric material layers is manufactured, of which the sound absorption coefficients are measured in an impedance tube. The experimental results show good agreement with the finite element simulation results. It is proved that a serial R-L circuit can control the peak frequency, maximum and bandwidth of the sound absorption coefficient and the combining R-L circuits shunted to multiple layers can control the sound absorption coefficients at multiple frequencies.

  19. Influence of TEM specimen preparation on chemical composition of Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals.

    PubMed

    Srot, Vesna; Gec, Medeja; van Aken, Peter A; Jeon, Jae-Ho; Ceh, Miran

    2014-07-01

    The influences of different transmission electron microscopy (TEM) specimen preparation techniques on the chemical composition of Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) single crystals was studied. Ion-milled samples where no cooling with liquid nitrogen (L-N2) was applied show permanently changed composition also deep inside the bulk material. When the PMN-PT samples were cooled to L-N2 temperature during the ion-milling process and in addition lower accelerating voltages were used, the chemical composition was altered only in the thinnest parts close to the specimen edge. Samples prepared using only tripod polishing technique show compositional irregularities close to the specimen edge. For the preparation of lead-containing samples, such as PMN-PT single crystals, a combination of tripod polishing and short Ar-ion-milling at low accelerating voltages while cooling the samples to liquid nitrogen temperature proved to be the most suitable to obtain artefact-free electron-transparent TEM lamellae.

  20. Fabrication and Performance of Endoscopic Ultrasound Radial Arrays Based on PMN-PT Single Crystal/Epoxy 1-3 Composite

    PubMed Central

    Zhou, Dan; Cheung, Kwok Fung; Chen, Yan; Lau, Sien Ting; Zhou, Qifa; Shung, K. Kirk; Luo, Hao Su; Dai, Jiyan; Chan, Helen Lai Wa

    2011-01-01

    In this paper, 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-PT) single crystal/epoxy 1–3 composite was used as the active material of the endoscopic ultrasonic radial array transducer, because this composite exhibited ultrahigh electromechanical coupling coefficient (kt = 0.81%), very low mechanical quality factor (Qm = 11) and relatively low acoustic impedance (Zt = 12 MRayls). A 6.91 MHz PMN-PT/epoxy 1–3 composite radial array transducer with 64 elements was tested in a pulse-echo response measurement. The −6-dB bandwidth of the composite array transducer was 102%, which was ~30% larger than that of traditional lead zirconate titanate array transducer. The two-way insertion loss was found to be −32.3 dB. The obtained results show that this broadband array transducer is promising for acquiring high-resolution endoscopic ultrasonic images in many clinical applications. PMID:21342833

  1. Piezoelectric energy harvesting based on shear mode 0.71Pb(Mg(1/3)Nb(2/3))O3-0.29PbTiO3 single crystals.

    PubMed

    Ren, Bo; Or, Siu Wing; Wang, Feifei; Zhao, Xiangyong; Luo, Haosu; Li, Xiaobing; Zhang, Qinhui; Di, Wenning; Zhang, Yaoyao

    2010-06-01

    In this paper we theoretically and experimentally present a nonresonant vibration energy harvesting device based on the shear mode of 0.71Pb(Mg(1/3)Nb(2/3))O3-0.29PbTiO3 single crystals. The electrical properties of the energy harvesting device were evaluated using an analytical method. Good consistency was obtained between the analytical and experimental results. Under a mass load of 200 g, a peak voltage of 11.3 V and maximum power of 0.70 mW were obtained at 500 Hz when connecting a matching load resistance of 91 komega. A high output could always be obtained within a very wide frequency range. The results demonstrate the potential of the device in energy harvesting applied to low-power portable electronics and wireless sensors.

  2. Coupled domain wall motion, lattice strain and phase transformation in morphotropic phase boundary composition of PbTiO3-BiScO3 piezoelectric ceramic

    SciTech Connect

    Khatua, Dipak Kumar; V., Lalitha K.; Fancher, Chris M.; Jones, Jacob L.; Ranjan, Rajeev

    2016-10-18

    High energy synchrotron X-ray diffraction, in situ with electric field, was carried out on the morphotropic phase boundary composition of the piezoelectric alloy PbTiO3-BiScO3. We demonstrate a strong correlation between ferroelectric-ferroelastic domain reorientation, lattice strain and phase transformation. Lastly, we also show the occurrence of the three phenomena and persistence of their correlation in the weak field regime.

  3. Fabrication and charge/energy-transfer study of 4,7-bis(4-triphenylamino)benzo- 2,1,3-thiadiazole/CuPc composite films

    NASA Astrophysics Data System (ADS)

    Zhu, Yuanyuan; Gu, Shuangxi; Wei, Xiao; Xue, Minzhao; Zhang, Qing; Sheng, Qiaorong; Liu, Yangang

    2010-12-01

    Composite films of 4,7-bis(4-triphenylamino)benzo-2,1,3-thiadiazole (TBT) and copper phthalocyanine (CuPc) are fabricated via protonation-coelectrophoretic deposition from nitromethane solutions of TBT/CuPc mixture in the presence of trifluoroacetic acid as a protonation reagent. A nanospheres-nanowires interpenetrating network structure is obtained when the molar percentage of TBT is 70%. Furthermore, the existence of TBT makes α-phased CuPc be partly transformed into the β-phase, and simultaneously, CuPc disorganizes the TBT unit cells. The blue shift on the absorption edge of TBT and the significant fluorescence quenching in the composite films indicate energy/charge transfer and donor-acceptor (D-A) heterojunction formation. Then these results are proved from another point of view: the mutual overlap of absorption and emission spectra of TBT and CuPc lead to a bidirectional Förster resonance energy transfer at the interface; the molecular energy levels calculated from the results of cyclic voltammetry theoretically determine that there exist a D-A heterojunction and charge transfer from TBT to CuPc. Finally, from the investigation of the field-induced surface photovoltage spectra, it can be concluded that this charge transfer results in efficient dissociation of the photoinduced excitons in the composite films, followed by the generation of a strong photovoltage response.

  4. Tunable and purified luminescence via energy transfer and delamination of LRH (R=Tb, Y) composites with 8-hydroxypyrene-1,3,6-trisulphonate.

    PubMed

    Su, Feifei; Liu, Chenyu; Yang, Yan; Ma, Shulan; Sun, Genban; Yang, Xiaojing

    2017-06-15

    This work demonstrates tunable and purified luminescence via one-step delamination of HPTS/OS-LRH composites (HPTS is trisodium 8-hydroxy-pyrene-1,3,6-trisulphonate, OS is sodium salt of 1-octane sulfonic acid, LRH is layered rare-earth hydroxide, R=Tb, Y) along with energy transfer. The HPTSxOS1-x-LTbyY1-yH composites presented varied luminescence behavior depending on their physical state. In solid state, dual-color luminescence was observed: blue-dominant emissions (437nm) for HPTSxOS1-x-LTbH, and blue- (437nm) to green-dominant (516nm) luminescence for HPTS0.02OS0.98-LTbyY1-yH. In delaminated state in famamide, purified luminescence was present: pure blue emission (440nm) for HPTSxOS1-x-LTbH and HPTS0.02OS0.98-LTbyY1-yH (y≥0.5), while pure bluish-green emission (498nm) for HPTS0.02OS0.98-LTbyY1-yH (y≤0.3). Both the delamination of the composites and energy transfer from layer Tb(3+) to HPTS contributed to the blue luminescence. The intriguing energy transfer process between photoactive inorganic hosts and organic guests can be utilized to fabricate hybrid materials with superior luminescence property.

  5. Changes in composition and pore space of sand rocks in the oil water contact zone (section YU1 3-4, Klyuchevskaya area, Tomsk region)

    NASA Astrophysics Data System (ADS)

    Nedolivko, N.; Perevertailo, T.; Pavlovec, T.

    2016-09-01

    The article provides an analysis of specific features in changes of rocks in the oil water contact zone. The object of study is the formation YU1 3-4 (J3o1) of Klyuchevskaya oil deposit (West Siberian oil-gas province, Tomsk region). The research data allow the authors to determine vertical zoning of the surface structure and identify the following zones: oil saturation (weak alteration), bitumen-content dissolution, non-bitumen-content dissolution, cementation, including rocks not affected by hydrocarbon deposit. The rocks under investigation are characterized by different changes in composition, pore space, as well as reservoir filtration and volumetric parameters. Detection of irregularity in distribution of void- pore space in oil-water contact zones is of great practical importance. It helps to avoid the errors in differential pressure drawdown and explain the origin of low-resistivity collectors.

  6. Piezoelectric ultrasonic motors

    SciTech Connect

    Wallaschek, J.

    1994-12-31

    Piezoelectric ultrasonic motors are a new type of actuator. They are characterized by high torque at low rotational speed, simple mechanical design and good controllability. They also provide a high holding torque even if no power is applied. Compared to electromagnetic actuators the torque per volume ratio of piezoelectric ultrasonic motors can be higher by an order of magnitude. Recently various types of piezoelectric ultrasonic motors have been developed for industrial applications. This paper describes several types of piezoelectric ultrasonic motors.

  7. Composition Dependence of Electrocaloric Effect in (1 - x)Pb(Mg1/3Nb2/3)O3 -xPbTiO3 Single Crystals

    NASA Astrophysics Data System (ADS)

    Qiu, Jian-Hua; Wang, Xiu-Qin; Yuan, Ning-Yi; Ding, Jian-Ning

    2015-07-01

    Composition dependence of electrocaloric effect is investigated in (1 - x)Pb(Mg1/3Nb2/3)O3 - xPbTiO3 single crystals by using an eighth-order Landau-Devonshire theory. The applied electric field along [001] direction reduces the ferroelectric-ferroelectric phase transition temperatures, but increases the Curie temperatures. The electrocaloric coefficients of tetragonal phase are much larger than that of rhombohedral and monoclinic phase. A negative electrocaloric effect is observed near the MC-T phase transition in 0.69Pb(Mg1/3Nb2/3)O3-0.31PbTiO3 single crystal. The application of a strong enough electric field results in a high adiabatic temperature change over a broad range of temperature. Therefore, it would be useful to construct a solid state cooling cycle over a broad temperature range for practical applications. Supported by the State Key Program of National Natural Science of China under Grant No. 51335002, Changzhou Science and Technology Project under Grant No. CJ20130022, and the Priority Academic Program Development of Jiangsu Higher Education Institutions on Renewable Energy Material Science and Engineering

  8. "Mighty Worm" Piezoelectric Actuator

    NASA Technical Reports Server (NTRS)

    Bamford, Robert M.; Wada, Ben K.; Moore, Donald M.

    1994-01-01

    "Mighty Worm" piezoelectric actuator used as adjustable-length structural member, active vibrator or vibration suppressor, and acts as simple (fixed-length) structural member when inactive. Load force not applied to piezoelectric element in simple-structural-member mode. Piezoelectric element removed from load path when not in use.

  9. Piezoelectric drive circuit

    DOEpatents

    Treu, C.A. Jr.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes. 7 figs.

  10. Piezoelectric drive circuit

    DOEpatents

    Treu, Jr., Charles A.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes.

  11. Piezoelectric Composite Micromachined Multifrequency Transducers for High-Resolution, High-Contrast Ultrasound Imaging for Improved Prostate Cancer Assessment

    DTIC Science & Technology

    2015-08-01

    682. S. Li, W. Chang, W. Huang, and X. Jiang, ൰-MHz Micromachined PMN-PT Composite Ultrasound Array for Medical Imaging ," in ASME 2015...Jiang, ൰-MHz Micromachined PMN-PT Composite Ultrasound Array for Medical Imaging ," in ASME 2015 International Mechanical Engineering Congress...Resolution, High- Contrast Ultrasound Imaging For Improved Prostate Cancer Assessment PRINCIPAL INVESTIGATOR: Paul A. Dayton CONTRACTING ORGANIZATION

  12. Piezoelectric paint sensor for ultrasonic NDE

    NASA Astrophysics Data System (ADS)

    Li, X.; Zhang, Y.

    2007-04-01

    This paper deals with a distributed acoustic emission sensing method, which is especially suitable for piezoelectric paint. Piezoelectric paint is a composite piezoelectric material that is comprised of tiny piezoelectric particles randomly dispersed within a polymer matrix phase. An overview of the distributed acoustic emission sensing method for defect monitoring is given in this paper. The use of piezoelectric materials for ultrasonic signal measurements is next discussed along with a series of ultrasonic tests performed to verify the ultrasonic sensing capability of piezoelectric paint. To examine the mechanism of the distributed acoustic emission sensing method for crack initiation detection, the results of a finite element simulation based study is presented in this paper. The finite element model used in the parametric study is calibrated with experimental data. The effect of sensor numbers included in the array has been studied using both simulation and experimental data. Based on the preliminary results of this study, piezoelectric paint sensor appears to hold a potential for use in on-line monitoring of cracks such as those caused by fatigue in metal structures although more work is still needed before successful practical application can be made.

  13. Dynamic magnetoelastic properties of epoxy-bonded Sm0.88Nd0.12Fe1.93 pseudo-1-3 negative magnetostrictive particulate composite

    NASA Astrophysics Data System (ADS)

    Yang, Fang; Leung, Chung Ming; Or, Siu Wing; Liu, Wei; Zhang, Zhidong; Duan, Yuan-Feng

    2012-04-01

    Pseudo-1-3 negative magnetostrictive particulate composite is prepared by embedding and aligning light rare earth (Sm and Nd)-based negative magnetostrictive Sm0.88Nd0.12Fe1.93 particles with randomly distributed sizes of 10-180 μm in a passive epoxy matrix using a particle volume fraction of 0.5. The dynamic magnetoelastic properties of the composite are investigated as a function of both magnetic bias field and frequency under a constant magnetic drive field. The dynamic relative permeability (μr33) exhibits a flat frequency response with no observable dispersion at all bias field levels, except for the fundamental shape resonance range of 40-50 kHz. The free (μr33T) and clamped (μr33S) relative permeabilities attain their maximum values at low bias field levels of ≤10 kA/m because of the relatively easy 180° domain-wall motion. The elastic modulus at constant magnetic field strength (E3H) and that at constant magnetic flux density (E3B) show a maximum negative-ΔE effect, accompanying a maximum dynamic strain coefficient (d33) of -2 nm/A, at about 100 kA/m due to the maximum motion of non-180° domain walls.

  14. Deposition of antibacterial of poly(1,3-bis-(p-carboxyphenoxy propane)-co-(sebacic anhydride)) 20:80/gentamicin sulfate composite coatings by MAPLE

    NASA Astrophysics Data System (ADS)

    Cristescu, R.; Popescu, C.; Socol, G.; Visan, A.; Mihailescu, I. N.; Gittard, S. D.; Miller, P. R.; Martin, T. N.; Narayan, R. J.; Andronie, A.; Stamatin, I.; Chrisey, D. B.

    2011-04-01

    We report on thin film deposition of poly(1,3-bis-(p-carboxyphenoxy propane)-co-sebacic anhydride)) 20:80 thin films containing several gentamicin concentrations by matrix assisted pulsed laser evaporation (MAPLE). A pulsed KrF* excimer laser was used to deposit the polymer-drug composite thin films. Release of gentamicin from these MAPLE-deposited polymer conjugate structures was assessed. Fourier transform infrared spectroscopy was used to demonstrate that the functional groups of the MAPLE-transferred materials were not changed by the deposition process nor were new functional groups formed. Scanning electron microscopy confirmed that MAPLE may be used to fabricate thin films of good morphological quality. The activity of gentamicin-doped films against Escherichia coli and Staphylococcus aureus bacteria was demonstrated using disk diffusion and antibacterial drop test. Our studies indicate that deposition of polymer-drug composite thin films prepared by MAPLE is a suitable technique for performing controlled drug delivery. Antimicrobial thin film coatings have several medical applications, including use for indwelling catheters and implanted medical devices.

  15. Quantitative analysis of magnetization reversal in Ni thin films on unpoled and poled (0 1 1) [PbMg1/3Nb2/3O3]0.68-[PbTiO3]0.32 piezoelectric substrates

    NASA Astrophysics Data System (ADS)

    Tkach, Alexander; Kehlberger, Andreas; Büttner, Felix; Jakob, Gerhard; Eisebitt, Stefan; Kläui, Mathias

    2016-08-01

    The field angle dependence of the magnetization reversal in 20 nm thick polycrystalline Ni films grown on piezoelectric (0 1 1) [PbMg1/3Nb2/3O3]0.68-[PbTiO3]0.32 (PMN-PT) substrates is analysed quantitatively to study the magnetic anisotropy induced in the film by poling the piezosubstrate. While the PMN-PT is in the unpoled state, the magnetization reversal is almost isotropic as expected from the polycrystalline nature of the film and corresponding to an orientation ratio (OR) of 1.2. The orientation ratio is obtained by fitting the angular dependence of normalized remanent magnetization to an adapted Stoner-Wohlfarth relation. Upon poling the piezosubstrate, a strong uniaxial anisotropy, whose hard axis is oriented along the [1 0 0] direction of the PMN-PT, is induced, yielding an OR of 3.1. The angular dependence of the coercivity for the poled state is found to consist of a strong increase for increasing field angles away from the easy axis direction and of a sharp decrease for angles close to the hard direction. It is best described by a two-phase model, implying that the magnetization reversal is determined by both, coherent rotation of the magnetic moments, according to the Stoner-Wohlfarth model, and the gradual displacement of the domain walls in obedience to the Kondorsky model.

  16. Measurements along the growth direction of PMN-PT crystals: dielectric, piezoelectric, and elastic properties.

    PubMed

    Tian, Jian; Han, Pengdi; Payne, David A

    2007-09-01

    Property measurements are reported for Pb(Mg1/3Nb2/3)03-PbTiO3 (PMN-PT) single crystals grown along (001) by a seeded-melt method. Chemical segregation occurs during crystal growth, leading to property changes along the growth direction. Variations in dielectric, piezoelectric, and elastic properties were evaluated for specimens selected from the crystals. Room-temperature data are correlated with Tc and composition that ranged from 27 to 32% PT, i.e., in the vicinity of the morphotropic phase boundary (MPB). While there was little change in the high electromechanical coupling factor k33 (0.87-0.92), both the piezoelectric charge coefficient d33 (1100-1800 pC/N) and the free dielectric constant K3 (4400-7000) were found to vary significantly with position. Increases in d33 and KT33 were relatively offsetting in that the ratio yielded a relatively stable piezoelectric voltage coefficient g33 (27-31 x 10(-3) Vm/N). Values are also reported for the elastic compliance (3.3-6.3 x 10(-11) m2/N) determined from resonance measurements. Enhancements in d33 and K(T)33 were associated with lattice softening (increasing sE33) as the composition approached the MPB. Details are reported for the piezoelectric, dielectric, and elastic properties as a function of growth direction, Tc, and composition. The results are useful for an understanding of properties in PMN-PT crystals and for the design of piezoelectric devices.

  17. Temperature Dependence of the Electromechanical Properties of O-3 PbTiO3-Polymer Piezoelectric Composite Materials

    DTIC Science & Technology

    1994-07-01

    WLF theory), which explains the influence of the glass transition on the elastic properties of polymers, is used to describe temperature dependence ...of the elastic and dielectric properties of the composite materials. The temperature dependence of the dielectric permittivity is shown to be similar...in form to the temperature dependence of the elastic properties. The application of the time-temperature superposition principle for shifting

  18. Piezoelectrically assisted ultrafiltration

    SciTech Connect

    Ahner, N.; Gottschlich, D.; Narang, S.; Roberts, D.; Sharma, S.; Ventura, S.

    1993-01-01

    The authors have demonstrated the feasibility of using piezoelectrically assisted ultrafiltration to reduce membrane fouling and enhance the flux through ultrafiltration membranes. A preliminary economic evaluation, accounting for the power consumption of the piezoelectric driver and the extent of permeate flow rate enhancement, has also shown that piezoelectrically assisted ultrafiltration is cost effective and economically competitive in comparison with traditional separation processes. Piezoelectric transducers, such as a piezoelectric lead zirconate titanate (PZT) disc or a piezoelectric horn, driven by moderate power, significantly enhance the permeate flux on fouled membranes, presumably because they promote local turbulence. Several experiments were conducted on polysulfone and regenerated cellulose UF membranes fouled during filtration of model feed solutions. Solutions of poly(ethylene glycol) and of high-molecular weight dextran were used as models. The authors found that they could significantly increase the permeate flux by periodically driving the piezoelectric transducer, horn or PZT disc, by application of moderate power over short periods of time, from 20 to 90 seconds. Enhancements as high as a factor of 8 were recorded within a few seconds, and enhanced permeate fluxes were maintained over a prolonged period (up to 3 hours). The prolonged flux enhancement makes it feasible to drive the piezoelectric transducer intermittently, thereby reducing the power consumption of the piezoelectric driver. As piezoelectric drivers of sonically assisted ultrafiltration, PZT disc transducers are preferred over the piezoelectric horn because of their small size and ease of adaptability to ultrafiltration test cells. The horn transmits sonic energy to the UF membrane through a titanium element driven by a separate piezoelectric transducer, but a piezoelectric ceramic disc transmits energy directly to the UF membrane.

  19. A piezoelectric transformer

    NASA Technical Reports Server (NTRS)

    Won, C. C.

    1993-01-01

    This work describes a modeling and design method whereby a piezoelectric system is formulated by two sets of second-order equations, one for the mechanical system, and the other for the electrical system, coupled through the piezoelectric effect. The solution to this electromechanical coupled system gives a physical interpretation of the piezoelectric effect as a piezoelectric transformer that is a part of the piezoelectric system, which transfers the applied mechanical force into a force-controlled current source, and short circuit mechanical compliance into capacitance. It also transfers the voltage source into a voltage-controlled relative velocity input, and free motional capacitance into mechanical compliance. The formulation and interpretation simplify the modeling of smart structures and lead to physical insight that aids the designer. Due to its physical realization, the smart structural system can be unconditional stable and effectively control responses. This new concept has been demonstrated in three numerical examples for a simple piezoelectric system.

  20. Effect of PMS modification on dielectric and piezoelectric properties in xPMS (1 - x)PZT ceramics

    NASA Astrophysics Data System (ADS)

    Zhu, Z. G.; Li, G. R.; Xu, Z. J.; Zhang, W. Z.; Yin, Q. R.

    2005-05-01

    The structural, dielectric and piezoelectric properties of xPMS-(1 - x)PZT ceramics were investigated as a function of Pb(Mn1/3Sb2/3)O3 (PMS) content by x-ray diffraction, scanning electron microscopy, and dielectric and piezoelectric spectroscopy techniques. All the Pb(Mn1/3Sb2/3)O3-PbZrO3-PbTiO3 (PMS-PZT) samples exhibit a single phase of perovskite structure with tetragonal symmetry. Dielectric studies revealed that the phase transition temperature (Tc) is suppressed with increasing PMS content. For PMS-PZT samples with 0.08 <= x <= 0.15, the maximum dielectric constant decreases as the measurement frequencies increase and the permittivity maximum temperature (Tm) is shifted towards higher temperatures as well, which indicates that dielectric relaxor behaviour was observed, while for x = 0.02 and 0.05, there is no shift in Tm, which implies normal ferroelectric behaviour. The samples with a composition of x = 0.05 exhibit excellent dielectric and piezoelectric properties (ɛr = 1540, d33 = 360 pC N-1, Kp = 0.58, tan δ = 0.45%, Qm = 1210) and, therefore, should be ideal candidates for high-power applications, such as in piezoelectric transformers.

  1. Piezoelectric and magnetoelectric thick films for fabricating power sources in wireless sensor nodes.

    PubMed

    Priya, Shashank; Ryu, Jungho; Park, Chee-Sung; Oliver, Josiah; Choi, Jong-Jin; Park, Dong-Soo

    2009-01-01

    In this manuscript, we review the progress made in the synthesis of thick film-based piezoelectric and magnetoelectric structures for harvesting energy from mechanical vibrations and magnetic field. Piezoelectric compositions in the system Pb(Zr,Ti)O(3)-Pb(Zn(1/3)Nb(2/3))O(3) (PZNT) have shown promise for providing enhanced efficiency due to higher energy density and thus form the base of transducers designed for capturing the mechanical energy. Laminate structures of PZNT with magnetostrictive ferrite materials provide large magnitudes of magnetoelectric coupling and are being targeted to capture the stray magnetic field energy. We analyze the models used to predict the performance of the energy harvesters and present a full system description.

  2. Piezoelectric and Magnetoelectric Thick Films for Fabricating Power Sources in Wireless Sensor Nodes

    PubMed Central

    Priya, Shashank; Ryu, Jungho; Park, Chee-Sung; Oliver, Josiah; Choi, Jong-Jin; Park, Dong-Soo

    2009-01-01

    In this manuscript, we review the progress made in the synthesis of thick film-based piezoelectric and magnetoelectric structures for harvesting energy from mechanical vibrations and magnetic field. Piezoelectric compositions in the system Pb(Zr,Ti)O3–Pb(Zn1/3Nb2/3)O3 (PZNT) have shown promise for providing enhanced efficiency due to higher energy density and thus form the base of transducers designed for capturing the mechanical energy. Laminate structures of PZNT with magnetostrictive ferrite materials provide large magnitudes of magnetoelectric coupling and are being targeted to capture the stray magnetic field energy. We analyze the models used to predict the performance of the energy harvesters and present a full system description. PMID:22454590

  3. Determination of dynamic young's modulus, shear modulus, and poisson's ratio as a function of temperature for depleted Uranium-0.75 wt% Titanium using the piezoelectric ultrasonic composite oscillator technique

    NASA Astrophysics Data System (ADS)

    Keene, K. H.; Hartman, J. T.; Wolfenden, A.; Ludtka, G. M.

    1987-07-01

    Dynamic Young's modulus ( E) and shear modulus ( G) measurements were performed for three microstructures (gamma, alpha + delta, and alpha prime) of a depleted uranium-0.75 wt% titanium alloy. Measurements were made from 298 to 1123 K. From the measured values of E and G, values were obtained for Poisson's ratio (PR). The experimental apparatus was the piezoelectric ultrasonic composite oscillator technique (PUCOT) at 40 or 80 kHz. The ranges of values for E, G, and PR were 193 to 99 GPa, 81 to 35 GPa, and 0.17 to 0.56, respectively. Correlations for E, G, and PR as functions of temperature are presented.

  4. Hierarchical Domain Structures in Relaxor 24Pb(In1/2Nb1/2)O3-46Pb(Mg1/3Nb2/3)O3-30PbTiO3 near a Morphotropic Phase Boundary Composition Grown by Bridgman Method

    NASA Astrophysics Data System (ADS)

    Yasuda, Naohiko; Fuwa, Tomohiro; Ohwa, Hidehiro; Tachi, Yoshihito; Yamashita, Yohachi; Fujita, Kazuhiko; Iwata, Makoto; Terauchi, Hikaru; Ishibashi, Yoshihiro

    2011-09-01

    The domain structures of the lead-based relaxor ferroelectric solid solution single crystal, 24Pb(In1/2Nb1/2)O3 (PIN)-46Pb(Mg1/3Nb2/3)O3 (PMN)-30PbTiO3 (PT), near a morphotropic phase boundary (MPB) composition grown by the Bridgeman method were studied by polarized light microscopy (PLM), piezoresponse force microscopy (PFM) and scanning electron microscopy (SEM). The change in domain structures with poling from rhombohedral spindlelike domains of 3-5 µm width to orthorhombic domains of ˜20 µm width with rectangular cells with a size of 3-5 µm, characterized with an antiferroelectic double hysteresis loop in the electric field-induced strain behavior, was found. Such domain structures were microscopically identified from SEM images as small circular tetragonal defects, planar monoclinic defects such as edge and screw dislocations with Burgers vector b along <110>cub and/or <100>cub directions and their agglomerate rectangular orthorhombic defects, also characterized by PFM. Hierarchical domain structures are discussed from the viewpoints of domain structures due to defects such as edge and screw dislocations originating in the chemical order region (COR) and the piezoelectric responses and dielectric properties.

  5. Passively Damped Laminated Piezoelectric Shell Structures with Integrated Electric Networks

    NASA Technical Reports Server (NTRS)

    Saravanos, Dimitris A.

    1999-01-01

    Multi-field mechanics are presented for curvilinear piezoelectric laminates interfaced with distributed passive electric components. The equations of motion for laminated piezoelectric shell structures with embedded passive electric networks are directly formulated and solved using a finite element methodology. The modal damping and frequencies of the piezoelectric shell are calculated from the poles of the system. Experimental and numerical results are presented for the modal damping and frequency of composite beams with a resistively shunted piezoceramic patch. The modal damping and frequency of plates, cylindrical shells and cylindrical composite blades with piezoelectric-resistor layers are predicted. Both analytical and experimental studies illustrate a unique dependence of modal damping and frequencies on the shunting resistance and show the effect of structural shape and curvature on piezoelectric damping.

  6. Molecular structure and conformational composition of 1,3-dihydroxyacetone studied by combined analysis of gas-phase electron diffraction data, rotational constants, and results of theoretical calculations. Ideal gas thermodynamic properties of 1,3-dihydroxyacetone.

    PubMed

    Dorofeeva, Olga V; Vogt, Natalja; Vogt, Jürgen; Popik, Mikhail V; Rykov, Anatolii N; Vilkov, Lev V

    2007-07-19

    The molecular structure of 1,3-dihydroxyacetone (DHA) has been studied by gas-phase electron diffraction (GED), combined analysis of GED and microwave (MW) data, ab initio, and density functional theory calculations. The equilibrium re structure of DHA was determined by a joint analysis of the GED data and rotational constants taken from the literature. The anharmonic vibrational corrections to the internuclear distances (re-ra) and to the rotational constants (B(i)e-B(i)0) needed for the estimation of the re structure were calculated from the B3LYP/cc-pVTZ cubic force field. It was found that the experimental data are well reproduced by assuming that DHA consists of a mixture of three conformers. The most stable conformer of C2v symmetry has two hydrogen bonds, whereas the next two lowest energy conformers (Cs and C1 symmetry) have one hydrogen bond and their abundance is about 30% in total. A combined analysis of GED and MW data led to the following equilibrium structural parameters (re) of the most abundant conformer of DHA (the uncertainties in parentheses are 3 times the standard deviations): r(C=O)=1.215(2) A, r(C-C)=1.516(2) A, r(C-O)=1.393(2) A, r(C-H)=1.096(4) A, r(O-H)=0.967(4) A, angleC-C=O=119.9(2) degrees, angleC-C-O=111.0(2) degrees, angleC-C-H=108.2(7) degrees, angleC-O-H=106.5(7) degrees. These structural parameters reproduce the experimental B(i)0 values within 0.05 MHz. The experimental structural parameters are in good agreement with those obtained from theoretical calculations. Ideal gas thermodynamic functions (S degrees (T), C degrees p(T), and H degrees (T)-H degrees (0)) of DHA were calculated on the basis of experimental and theoretical molecular parameters obtained in this work. The enthalpy of formation of DHA, -523+/-4 kJ/mol, was calculated by the atomization procedure using the G3X method.

  7. Composition and growth behavior of the surface and electrolyte decomposition layer of/on a commercial lithium ion battery LixNi1/3Mn1/3Co1/3O2 cathode determined by sputter depth profile X-ray photoelectron spectroscopy.

    PubMed

    Niehoff, Philip; Winter, Martin

    2013-12-23

    A detailed X-ray photoelectron spectroscopy (XPS) study of the surface and electrolyte decomposition layer of a LixNi1/3Mn1/3Co1/3O2 (NMC) cathode from commercial NMC/graphite cells by intense sputter depth profiling (SDP) using a polyatomic ion gun is provided. Cathodes of a cell after electrochemical formation and a cell at a state of initial capacity (SOIC) of 80%, which was reached after 2500 full cycles at 30 °C, are investigated.

  8. High Power Piezoelectric Characterization for Piezoelectric Transformer Development

    NASA Astrophysics Data System (ADS)

    Ural, Seyit O.

    circuit to leave the resonator in an open circuit condition. The newly introduced open circuits burst have resulted in antiresonance quality factor measurements along with resonance quality factors in a "non-heating" sample. In this technique too, resonance and antiresonance losses showed significant difference. Resonance burst mode characterizations at elevated ambient temperatures have shown that the lower vibration velocity mechanical quality factors appear to be more sensitive to the ambient temperature. Design criteria's to produce the most power dense structure were investigated. Common device shapes were investigated to see which one does enhance the power density of the piezoelectric device. Disk shaped piezoelectric actuators have proven to have lower matching impedances and higher, farther persisting mechanical quality factors with respect to vibration velocities. In order to achieve identical power level, plate shaped samples will have been to strain ~3.5 times more than disk shaped samples. Thus the most power dense structure has been concluded to be a disk shape ~1W/cm3 Once the actuators shape was fixed, further design on structure were conducted with (c)ATILA finite element method. For the transformer application, the design considered following key factors; 1-Controlling the output impedance by optimizing number of layers and layer thicknesses of the multilayer and 2- Evaluation of various electrodes and their affect on high power performance was evaluated. As the thickness of active layers decreased, the number of electrode layers increases. This increase in the metal to piezoelectric ratio and the relative increase in the electrode resistance under high current loads, both will have to be accounted for. Thus; with the piezoelectric composition and the device structure optimized, the research input electrical power. Once the actuators shape was fixed, further design on structure were conducted with (c)ATILA finite element method. For the transformer

  9. Progress in engineering high strain lead-free piezoelectric ceramics

    PubMed Central

    Leontsev, Serhiy O; Eitel, Richard E

    2010-01-01

    Environmental concerns are strongly driving the need to replace the lead-based piezoelectric materials currently employed as multilayer actuators. The current review describes both compositional and structural engineering approaches to achieve enhanced piezoelectric properties in lead-free materials. The review of the compositional engineering approach focuses on compositional tuning of the properties and phase behavior in three promising families of lead-free perovskite ferroelectrics: the titanate, alkaline niobate and bismuth perovskites and their solid solutions. The ‘structural engineering’ approaches focus instead on optimization of microstructural features including grain size, grain orientation or texture, ferroelectric domain size and electrical bias field as potential paths to induce large piezoelectric properties in lead-free piezoceramics. It is suggested that a combination of both compositional and novel structural engineering approaches will be required in order to realize viable lead-free alternatives to current lead-based materials for piezoelectric actuator applications. PMID:27877343

  10. Smart System Using New Piezoelectric Fiber with Metal Core

    NASA Astrophysics Data System (ADS)

    Shimojo, Yoshiro; Sato, Hiroshi; Takagi, Kiyoshi; Shan, Yue Jin; Imoto, Hideo; Nagamine, Masaru

    A new piezoelectric ceramic fiber containing a metal core was produced by the extrusion method. The insertion of a metal core is significant because the fiber's strength can be supported by the metal core which also serves as an internal electrode. A new smart board was designed by mounting these piezoelectric fibers into the surface of a CFRP composite. This smart composite board was able to both detect, and suppress vibrations.

  11. Advanced piezoelectric single crystal based transducers for naval sonar applications

    NASA Astrophysics Data System (ADS)

    Snook, Kevin A.; Rehrig, Paul W.; Hackenberger, Wesley S.; Jiang, Xiaoning; Meyer, Richard J., Jr.; Markley, Douglas

    2005-05-01

    TRS is developing new transducers based on single crystal piezoelectric materials such as Pb(Mg1/3Nb2/3)x-1TixO3 (PMN-PT). Single crystal piezoelectrics such as PMN-PT exhibit very high piezoelectric coefficients (d33 ~ 1800 to >2000 pC/N) and electromechanical coupling factors (k33 > 0.9), respectively, which may be exploited for improving the performance of broad bandwidth and high frequency sonar. Apart from basic performance, much research has been done on reducing the size and increasing the output power of tonpilz transducers for sonar applications. Results are presented from two different studies. "33" mode single crystal tonpilz transducers have reduced stack lengths due to their low elastic stiffness relative to PZTs, however, this produces non-ideal aspect ratios due to large lateral dimensions. Alternative "31" resonance mode tonpilz elements are proposed to improve performance over these "33" designs. d32 values as high as 1600 pC/N have been observed, and since prestress is applied perpendicular to the poling direction, "31" mode Tonpilz elements exhibit lower loss and higher reliability than "33" mode designs. Planar high power tonpilz arrays are the optimum way to obtain the required acoustic pressure and bandwidth for small footprint, high power sensors. An important issue for these sensors is temperature and prestress stability, since fluctuations in tonpilz properties affects power delivery and sensing electronic design. TRS used the approach of modifying the composition of PMN-PT to improve the temperature dependence of properties of the material. Results show up to a 50% decrease in temperature change while losing minimal source level.

  12. Piezoelectric cantilever sensors

    NASA Technical Reports Server (NTRS)

    Shih, Wan Y. (Inventor); Shih, Wei-Heng (Inventor); Shen, Zuyan (Inventor)

    2008-01-01

    A piezoelectric cantilever with a non-piezoelectric, or piezoelectric tip useful as mass and viscosity sensors. The change in the cantilever mass can be accurately quantified by monitoring a resonance frequency shift of the cantilever. For bio-detection, antibodies or other specific receptors of target antigens may be immobilized on the cantilever surface, preferably on the non-piezoelectric tip. For chemical detection, high surface-area selective absorbent materials are coated on the cantilever tip. Binding of the target antigens or analytes to the cantilever surface increases the cantilever mass. Detection of target antigens or analytes is achieved by monitoring the cantilever's resonance frequency and determining the resonance frequency shift that is due to the mass of the adsorbed target antigens on the cantilever surface. The use of a piezoelectric unimorph cantilever allows both electrical actuation and electrical sensing. Incorporating a non-piezoelectric tip (14) enhances the sensitivity of the sensor. In addition, the piezoelectric cantilever can withstand damping in highly viscous liquids and can be used as a viscosity sensor in wide viscosity range.

  13. Piezoelectric coefficients and spontaneous polarization of ScAlN.

    PubMed

    Caro, Miguel A; Zhang, Siyuan; Riekkinen, Tommi; Ylilammi, Markku; Moram, Michelle A; Lopez-Acevedo, Olga; Molarius, Jyrki; Laurila, Tomi

    2015-06-24

    We present a computational study of spontaneous polarization and piezoelectricity in Sc(x)Al(1-x)N alloys in the compositional range from x = 0 to x = 0.5, obtained in the context of density functional theory and the Berry-phase theory of electric polarization using large periodic supercells. We report composition-dependent values of piezoelectric coefficients e(ij), piezoelectric moduli d(ij) and elastic constants C(ij). The theoretical findings are complemented with experimental measurement of e33 for a series of sputtered ScAlN films carried out with a piezoelectric resonator. The rapid increase with Sc content of the piezoelectric response reported in previous studies is confirmed for the available data. A detailed description of the full methodology required to calculate the piezoelectric properties of ScAlN, with application to other complex alloys, is presented. In particular, we find that the large amount of internal strain present in ScAlN and its intricate relation with electric polarization make configurational sampling and the use of large supercells at different compositions necessary in order to accurately derive the piezoelectric response of the material.

  14. Green piezoelectric for autonomous smart textile

    NASA Astrophysics Data System (ADS)

    Lemaire, E.; Borsa, C. J.; Briand, D.

    2015-12-01

    In this work, the fabrication of Rochelle salt based piezoelectric textiles are shown. Structures composed of fibers and Rochelle salt are easily produced using green processes. Both manufacturing and the material itself are really efficient in terms of environmental impact, considering the fabrication processes and the material resources involved. Additionally Rochelle salt is biocompatible. In this green paradigm, active sensing or actuating textiles are developed. Thus processing method and piezoelectric properties have been studied: (1) pure crystals are used as acoustic actuator, (2) fabrication of the textile-based composite is detailed, (3) converse effective d33 is evaluated and compared to lead zirconate titanate ceramic. The utility of textile-based piezoelectric merits its use in a wide array of applications.

  15. Enhanced piezoelectric performance from carbon fluoropolymer nanocomposites

    NASA Astrophysics Data System (ADS)

    Baur, Cary; DiMaio, Jeffrey R.; McAllister, Elliot; Hossini, Reza; Wagener, Earl; Ballato, John; Priya, Shashank; Ballato, Arthur; Smith, Dennis W.

    2012-12-01

    The piezoelectric performance of polyvinylidene fluoride (PVDF) is shown to double through the controlled incorporation of carbon nanomaterial. Specifically, PVDF composites containing carbon fullerenes (C60) and single-walled carbon nanotubes (SWNT) are fabricated over a range of compositions and optimized for their Young's modulus, dielectric constant, and d31 piezoelectric coefficient. Thermally stimulated current measurements show a large increase in internal charge and polarization in the composites over pure PVDF. The electromechanical coupling coefficients (k31) at optimal loading levels are found to be 1.84 and 2 times greater than pure PVDF for the PVDF-C60 and PVDF-SWNT composites, respectively. Such property-enhanced nanocomposites could have significant benefit to electromechanical systems employed for structural sensing, energy scavenging, sonar, and biomedical imaging.

  16. Characterization of porous piezoelectric ceramics: The length expander case

    SciTech Connect

    Gomez Alvarez-Arenas, T.E.; Montero de Espinosa, F.

    1997-12-01

    Porous piezoelectric ceramics and 0{endash}3/3{endash}3 connectivity piezoelectric composites are normally characterized following the Standards on Piezoelectricity. Nevertheless, these materials are not homogeneous and losses are significant. New constitutive and wave equations have been obtained recently for these kind of materials. The objective of this paper is to derive new definitions for the electromechanical coupling coefficients and a suitable characterization procedure according to the new constitutive and wave equations previously mentioned. In particular, the case of the length expander bar mode is analyzed in detail. The study of resonant elements requires the use of suitable boundary conditions. In this case the boundary conditions are borrowed from the theory of poroelasticity and extended for a piezoelectric material. Finally the procedure is applied to characterize a commercial porous piezoelectric ceramic. {copyright} {ital 1997 Acoustical Society of America.}

  17. Mechanical properties of metal-core piezoelectric fiber

    NASA Astrophysics Data System (ADS)

    Sato, Hiroshi; Nagamine, Masaru

    2005-05-01

    In the previous conference, we produced a new metal core-containing piezoelectric ceramics fiber by the hydrothermal method and extrusion method. The insertion of metal core is significant in view of its greater strength than ceramics materials, and electrodes are not required in the fiber's sensor and actuator applications. A new smart board was designed by mounting these piezoelectric fibers onto the surface of a CFRP composite. After that, this board is able to use this board to a sensor, actuator and vibration suppression. In this paper, we measured s mechanical properties of metal core piezoelectric fiber. We examined the tension test of a piezo-electric fiber, and measured the Young's modulus and breaking strength. Moreover, the expansion in the fiber unit was measured, and the displacement of the direction of d31 was measured. In addition, a piezo-electric fiber that used lead free material (BNT-BT-BKT) to correspond to environmental problems in recent years was made.

  18. Adaptive piezoelectric sensoriactuator

    NASA Technical Reports Server (NTRS)

    Clark, Jr., Robert L. (Inventor); Vipperman, Jeffrey S. (Inventor); Cole, Daniel G. (Inventor)

    1996-01-01

    An adaptive algorithm implemented in digital or analog form is used in conjunction with a voltage controlled amplifier to compensate for the feedthrough capacitance of piezoelectric sensoriactuator. The mechanical response of the piezoelectric sensoriactuator is resolved from the electrical response by adaptively altering the gain imposed on the electrical circuit used for compensation. For wideband, stochastic input disturbances, the feedthrough capacitance of the sensoriactuator can be identified on-line, providing a means of implementing direct-rate-feedback control in analog hardware. The device is capable of on-line system health monitoring since a quasi-stable dynamic capacitance is indicative of sustained health of the piezoelectric element.

  19. Notes on Piezoelectricity

    SciTech Connect

    Redondo, Antonio

    2016-02-03

    These notes provide a pedagogical discussion of the physics of piezoelectricity. The exposition starts with a brief analysis of the classical (continuum) theory of piezoelectric phenomena in solids. The main subject of the notes is, however, a quantum mechanical analysis. We first derive the Frohlich Hamiltonian as part of the description of the electron-phonon interaction. The results of this analysis are then employed to derive the equations of piezoelectricity. A couple of examples with the zinc blende and and wurtzite structures are presented at the end

  20. Analysis and Testing of Plates with Piezoelectric Sensors and Actuators

    NASA Technical Reports Server (NTRS)

    Bevan, Jeffrey S.

    1998-01-01

    Piezoelectric material inherently possesses coupling between electrostatics and structural dynamics. Utilizing linear piezoelectric theory results in an intrinsically coupled pair of piezoelectric constitutive equations. One equation describes the direct piezoelectric effect where strains produce an electric field and the other describes the converse effect where an applied electrical field produces strain. The purpose of this study is to compare finite element analysis and experiments of a thin plate with bonded piezoelectric material. Since an isotropic plate in combination with a thin piezoelectric layer constitutes a special case of a laminated composite, the classical laminated plate theory is used in the formulation to accommodated generic laminated composite panels with multiple bonded and embedded piezoelectric layers. Additionally, the von Karman large deflection plate theory is incorporated. The formulation results in laminate constitutive equations that are amiable to the inclusion of the piezoelectric constitutive equations yielding in a fully electro-mechanically coupled composite laminate. Using the finite element formulation, the governing differential equations of motion of a composite laminate with embedded piezoelectric layers are derived. The finite element model not only considers structural degrees of freedom (d.o.f.) but an additional electrical d.o.f. for each piezoelectric layer. Comparison between experiment and numerical prediction is performed by first treating the piezoelectric as a sensor and then again treating it as an actuator. To assess the piezoelectric layer as a sensor, various uniformly distributed pressure loads were simulated in the analysis and the corresponding generated voltages were calculated using both linear and nonlinear finite element analyses. Experiments were carried out by applying the same uniformly distributed loads and measuring the resulting generated voltages and corresponding maximum plate deflections. It is

  1. Piezoelectric micromotors for microrobots

    NASA Astrophysics Data System (ADS)

    Flynn, Anita M.; Tavrow, Lee S.; Bart, Stephen F.; Brooks, Rodney A.; Ehrlich, Daniel J.; Udayakumar, K. R.; Cross, L. E.

    1992-03-01

    The authors have begun research into piezoelectric ultrasonic motors using ferroelectric thin films. The authors have fabricated the stator components of these millimeter diameter motors on silicon wafers. Ultrasonic motors consist of two pieces: a stator and a rotor. The stator includes a piezoelectric film in which bending is induced in the form of a traveling wave. A small glass lens placed upon the stator becomes the spinning rotor. Piezoelectric micromotors overcome the problems currently associated with electrostatic micromotors such as low torque, friction, and the need for high voltage excitation. More importantly, they may offer a much simpler mechanism for coupling power out. Using thin films of lead zirconate titanate on silicon nitride membranes, various types of actuator structures can be fabricated. By combining new robot control systems with piezoelectric motors and micromechanics, the authors propose creating micromechanical systems that are small, cheap and completely autonomous.

  2. Energy collection via Piezoelectricity

    NASA Astrophysics Data System (ADS)

    Naveen Kumar, Ch

    2015-12-01

    In the present days, wireless data transmission techniques are commonly used in electronic devices. For powering them connection needs to be made to the power supply through wires else power may be supplied from batteries. Batteries require charging, replacement and other maintenance efforts. So, some alternative methods need to be developed to keep the batteries full time charged and to avoid the need of any consumable external energy source to charge the batteries. Mechanical energy harvesting utilizes piezoelectric components where deformations produced by different means are directly converted to electrical charge via piezoelectric effect. The proposed work in this research recommends Piezoelectricity as a alternate energy source. The motive is to obtain a pollution-free energy source and to utilize and optimize the energy being wasted. Current work also illustrates the working principle of piezoelectric crystal and various sources of vibration for the crystal.

  3. Laminated piezoelectric transformer

    NASA Technical Reports Server (NTRS)

    Vazquez Carazo, Alfredo (Inventor)

    2006-01-01

    A laminated piezoelectric transformer is provided using the longitudinal vibration modes for step-up voltage conversion applications. The input portions are polarized to deform in a longitudinal plane and are bonded to an output portion. The deformation of the input portions is mechanically coupled to the output portion, which deforms in the same longitudinal direction relative to the input portion. The output portion is polarized in the thickness direction relative its electrodes, and piezoelectrically generates a stepped-up output voltage.

  4. Piezoelectric Energy Harvesting Solutions

    PubMed Central

    Caliò, Renato; Rongala, Udaya Bhaskar; Camboni, Domenico; Milazzo, Mario; Stefanini, Cesare; de Petris, Gianluca; Oddo, Calogero Maria

    2014-01-01

    This paper reviews the state of the art in piezoelectric energy harvesting. It presents the basics of piezoelectricity and discusses materials choice. The work places emphasis on material operating modes and device configurations, from resonant to non-resonant devices and also to rotational solutions. The reviewed literature is compared based on power density and bandwidth. Lastly, the question of power conversion is addressed by reviewing various circuit solutions. PMID:24618725

  5. Piezoelectrically Enhanced Photocathodes

    NASA Technical Reports Server (NTRS)

    Beach, Robert A.; Nikzad, Shouleh; Bell, Lloyd Douglas; Strittmatter, Robert

    2011-01-01

    Doping of photocathodes with materials that have large piezoelectric coefficients has been proposed as an alternative means of increasing the desired photoemission of electrons. Treating cathode materials to increase emission of electrons is called "activation" in the art. It has been common practice to activate photocathodes by depositing thin layers of suitable metals (usually, cesium). Because cesium is unstable in air, fabrication of cesiated photocathodes and devices that contain them must be performed in sealed tubes under vacuum. It is difficult and costly to perform fabrication processes in enclosed, evacuated spaces. The proposed piezoelectrically enhanced photocathodes would have electron-emission properties similar to those of cesiated photocathodes but would be stable in air, and therefore could be fabricated more easily and at lower cost. Candidate photocathodes include nitrides of elements in column III of the periodic table . especially compounds of the general formula Al(x)Ga(1.x)N (where 0< or = x < or =.1). These compounds have high piezoelectric coefficients and are suitable for obtaining response to ultraviolet light. Fabrication of a photocathode according to the proposal would include inducement of strain in cathode layers during growth of the layers on a substrate. The strain would be induced by exploiting structural mismatches among the various constituent materials of the cathode. Because of the piezoelectric effect in this material, the strain would give rise to strong electric fields that, in turn, would give rise to a high concentration of charge near the surface. Examples of devices in which piezoelectrically enhanced photocathodes could be used include microchannel plates, electron- bombarded charge-coupled devices, image tubes, and night-vision goggles. Piezoelectrically enhanced photocathode materials could also be used in making highly efficient monolithic photodetectors. Highly efficient and stable piezoelectrically enhanced

  6. Designing piezoelectric films for micro electromechanical systems.

    PubMed

    Trolier-McKinstry, Susan; Griggio, Flavio; Yaeger, Charles; Jousse, Pierre; Zhao, Dalong; Bharadwaja, Srowthi S N; Jackson, Thomas N; Jesse, Stephen; Kalinin, Sergei V; Wasa, Kiyotaka

    2011-09-01

    Piezoelectric thin films are of increasing interest in low-voltage micro electromechanical systems for sensing, actuation, and energy harvesting. They also serve as model systems to study fundamental behavior in piezoelectrics. Next-generation technologies such as ultrasound pill cameras, flexible ultrasound arrays, and energy harvesting systems for unattended wireless sensors will all benefit from improvements in the piezoelectric properties of the films. This paper describes tailoring the composition, microstructure, orientation of thin films, and substrate choice to optimize the response. It is shown that increases in the grain size of lead-based perovskite films from 75 to 300 nm results in 40 and 20% increases in the permittivity and piezoelectric coefficients, respectively. This is accompanied by an increase in the nonlinearity in the response. Band excitation piezoresponse force microscopy was used to interrogate the nonlinearity locally. It was found that chemical solution-derived PbZr(0.52)Ti(0.48)O(3) thin films show clusters of larger nonlinear response embedded in a more weakly nonlinear matrix. The scale of the clusters significantly exceeds that of the grain size, suggesting that collective motion of many domain walls contributes to the observed Rayleigh behavior in these films. Finally, it is shown that it is possible to increase the energy-harvesting figure of merit through appropriate materials choice, strong imprint, and composite connectivity patterns.

  7. Designing Piezoelectric Films for Micro Electromechanical Systems

    SciTech Connect

    Trolier-McKinstry, Susan; Griggio, Flavio; Yaeger, Charles; Jousse, Pierre; Zhao, Dalong; Bharadwaja, Srowthi; Jackson, Thomas N; Jesse, Stephen; Kalinin, Sergei V; Wasa, Kiyotaka

    2011-01-01

    Piezoelectric thin films are of increasing interest in low-voltage micro electromechanical systems for sensing, actuation, and energy harvesting. They also serve as model systems to study fundamental behavior in piezoelectrics. Next-generation technologies such as ultrasound pill cameras, flexible ultrasound arrays, and energy harvesting systems for unattended wireless sensors will all benefit from improvements in the piezoelectric properties of the films. This paper describes tailoring the composition, microstructure, orientation of thin films, and substrate choice to optimize the response. It is shown that increases in the grain size of lead-based perovskite films from 75 to 300 nm results in 40 and 20% increases in the permittivity and piezoelectric coefficients, respectively. This is accompanied by an increase in the nonlinearity in the response. Band excitation piezoresponse force microscopy was used to interrogate the nonlinearity locally. It was found that chemical solution-derived PbZr(0.52)Ti(0.48)O(3) thin films show clusters of larger nonlinear response embedded in a more weakly nonlinear matrix. The scale of the clusters significantly exceeds that of the grain size, suggesting that collective motion of many domain walls contributes to the observed Rayleigh behavior in these films. Finally, it is shown that it is possible to increase the energy-harvesting figure of merit through appropriate materials choice, strong imprint, and composite connectivity patterns.

  8. Membrane Vibration Tests Using Surface-Bonded Piezoelectric Patch Actuation

    NASA Technical Reports Server (NTRS)

    Gasper, James L.; Pappa, Richard S.

    2003-01-01

    This paper describes the status of on-going work at the NASA Langley Research Center to measure the dynamics of thin membranes. The test article is a one-meter square pre-tensioned Kapton membrane that incorporates small surface-bonded piezoelectric patches strategically positioned to excite many modes. It is shown that PVDF (polyvinylidene fluoride) and MFC (macro fiber composite) piezoelectric patch actuators provide adequate excitation energy to obtain modal frequencies and mode shapes. Results from modal tests performed on the membrane using piezoelectric patches of different sizes and positions are discussed.

  9. Poly[dithio-2,5-(1,3,4-thiadiazole)] (PDMcT)-poly(3,4-ethylenedioxythiophene) (PEDOT) composite cathode for high-energy lithium/lithium-ion rechargeable batteries

    NASA Astrophysics Data System (ADS)

    Kiya, Yasuyuki; Iwata, Asao; Sarukawa, Tomoo; Henderson, Jay C.; Abruña, Héctor D.

    We present a characterization of the redox behavior of organosulfur-based composite cathodes composed of poly[dithio-2,5-(1,3,4-thiadiazole)] (PDMcT), which is a polymer derived from 2,5-dimercapto-1,3,4-thiadiazole (DMcT), and poly(3,4-ethylenedioxythiophene) (PEDOT) in a carbonate-based mixed solvent containing 1.0 M LiBF 4. We have previously shown that PEDOT films, electrochemically generated at glassy carbon electrode surfaces, gave rise to a dramatic enhancement of the interfacial charge transfer kinetics of DMcT in solution. In a similar fashion, chemically prepared PEDOT films exhibited dramatic electrocatalytic activity towards the redox reactions of PDMcT in the composite cathodes. While the composite cathode exhibited a very high capacity of 205 mAh g -1 (based on the electroactive mass) at the first discharge, in subsequent charge/discharge tests, the capacity of the PDMcT-PEDOT composite cathode (1:1 mole ratio) decreased significantly because of dissolution of the reduction products of PDMcT into the electrolyte solution. We also found that an ionic polymer, consisting of a mixture of PEDOT and polystyrene sulfonate (PEDOT-PSS) could electrostatically, but not physically, prevent, at least in part, leaching of the DMcT species into the electrolyte solution, thus improving the coulomb efficiency for the redox reactions of DMcT in a PDMcT-PEDOT composite film during charge/discharge cycles.

  10. Piezoelectric Ceramics and Their Applications

    ERIC Educational Resources Information Center

    Flinn, I.

    1975-01-01

    Describes the piezoelectric effect in ceramics and presents a quantitative representation of this effect. Explains the processes involved in the manufacture of piezoelectric ceramics, the materials used, and the situations in which they are applied. (GS)

  11. PMN-PT nanowires with a very high piezoelectric constant.

    PubMed

    Xu, Shiyou; Poirier, Gerald; Yao, Nan

    2012-05-09

    A profound way to increase the output voltage (or power) of the piezoelectric nanogenerators is to utilize a material with higher piezoelectric constants. Here we report the synthesis of novel piezoelectric 0.72Pb(Mg(1/3)Nb(2/3))O(3)-0.28PbTiO(3) (PMN-PT) nanowires using a hydrothermal process. The unpoled single-crystal PMN-PT nanowires show a piezoelectric constant (d(33)) up to 381 pm/V, with an average value of 373 ± 5 pm/V. This is about 15 times higher than the maximum reported value of 1-D ZnO nanostructures and 3 times higher than the largest reported value of 1-D PZT nanostructures. These PMN-PT nanostructures are of good potential being used as the fundamental building block for higher power nanogenerators, high sensitivity nanosensors, and large strain nanoactuators.

  12. High Temperature Piezoelectric Drill

    NASA Technical Reports Server (NTRS)

    Bao, Xiaoqi; Scott, James; Boudreau, Kate; Bar-Cohen, Yoseph; Sherrit, Stewart; Badescu, Mircea; Shrout, Tom; Zhang, Shujun

    2009-01-01

    The current NASA Decadal mission planning effort has identified Venus as a significant scientific target for a surface in-situ sampling/analyzing mission. The Venus environment represents several extremes including high temperature (460 deg C), high pressure (9 MPa), and potentially corrosive (condensed sulfuric acid droplets that adhere to surfaces during entry) environments. This technology challenge requires new rock sampling tools for these extreme conditions. Piezoelectric materials can potentially operate over a wide temperature range. Single crystals, like LiNbO3, have a Curie temperature that is higher than 1000 deg C and the piezoelectric ceramics Bismuth Titanate higher than 600 deg C. A study of the feasibility of producing piezoelectric drills that can operate in the temperature range up to 500 deg C was conducted. The study includes the high temperature properties investigations of engineering materials and piezoelectric ceramics with different formulas and doping. The drilling performances of a prototype Ultrasonic/Sonic Drill/Corer (USDC) using high temperate piezoelectric ceramics and single crystal were tested at temperature up to 500 deg C. The detailed results of our study and a discussion of the future work on performance improvements are presented in this paper.

  13. Flexoelectric piezoelectric metamaterials based on the bending of ferroelectric ceramic wafers

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaotong; Liu, Jiliang; Chu, Mingjin; Chu, Baojin

    2016-08-01

    Conventional piezoelectric ceramics lose their piezoelectric properties near the Curie temperature (Tc), which limits their application at high temperatures. One approach to resolving this issue is to design flexoelectric piezoelectric composites or piezoelectric metamaterials by exploiting the flexoelectric effect of the ferroelectric materials. In this work, an experimental study on two designs of flexoelectric metamaterials is demonstrated. When a ferroelectric ceramic wafer is placed on a metal ring or has a domed shape, which is produced through the diffusion between two pieces of ferroelectric ceramic of different compositions at high temperatures, an apparent piezoelectric response originating from the flexoelectric effect can be measured under a stress. The apparent piezoelectric response of the materials based on the designs can be sustained well above Tc. This study provides an approach to designing materials for high-temperature electromechanical applications.

  14. Active Piezoelectric Diaphragms

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G.; Effinger, Robert T., IV; Aranda, Isaiah, Jr.; Copeland, Ben M.; Covington, Ed W., III

    2002-01-01

    Several active piezoelectric diaphragms were fabricated by placing unelectroded piezoelectric disks between copper clad films patterned with Inter-Circulating Electrodes "ICE". When a voltage potential is applied to the electrodes, the result is radially distributed electric field that mechanically strains the piezo-ceramic along the Z-axis (perpendicular to the applied electric field), rather than the expected in-plane (XY-axis) direction. Unlike other out of plane piezoelectric actuators, which are benders, these Radial Field Diaphragms (RFDs) strain concentrically yet afford high displacements while maintaining a constant circumference. This paper covers the fabrication and characterization of these diaphragms as a function of poling field strength, ceramic diameter and line spacing, as well as the surface topography, the resulting strain field and displacement as a function of applied voltage ranging from DC to 10 Hz.

  15. Piezoelectric Motors and Transformers

    NASA Astrophysics Data System (ADS)

    Uchino, K.

    Piezoelectric ceramics forms a new field between electronic and structural ceramics [1-4]. Application fields are classified into three categories: positioners, motors, and vibration suppressors. From the market research result for 80 Japanese component industries in 1992, tiny motors in the range of 5-8 mm are required in large numbers for office and portable equipment; the conventional electromagnetic (EM) motors are rather difficult to produce in this size with sufficient energy efficiency, while Silicon MEMS actuators are too small to be used in practice. Piezoelectric ultrasonic motors whose efficiency is insensitive to size are superior in the millimeter motor area. The manufacturing precision of optical instruments such as lasers and cameras, and the positioning accuracy for fabricating semiconductor chips are of the order of 0.1μm which is much smaller than the backlash of the EM motors. Vibration suppression in space structures and military vehicles also require compact but mighty piezoelectric actuators.

  16. Piezoelectric micromotors for microrobots

    NASA Astrophysics Data System (ADS)

    Flynn, Anita M.; Tavrow, Lee S.; Bart, Stephen F.; Brooks, Rodney A.

    1991-02-01

    Mobile robots are able to carry more and more intelligence (and in smaller packages) onboard everyday. Now we would like to match the brawn of our robots to the same scale as the brain. Towards this end, we have fabricated some small, a few millimeters in diameter, piezoelectric motors using ferroelectric thin films. These motors consist of two pieces: a stator and a rotor. The stationary stator includes a piezoelectric film in which we induce bending in the form of a traveling wave. Anything which sits atop the stator is propelled by the wave. A small glass lens placed upon the stator becomes the spinning rotor. Piezoelectric micromotors overcome the problems currently associated with electrostatic micromotors such as low torque, friction, and the need for high voltage excitation.

  17. Piezoelectric wave motor

    DOEpatents

    Yerganian, Simon Scott

    2003-02-11

    A piezoelectric motor having a stator in which piezoelectric elements are contained in slots formed in the stator transverse to the desired wave motion. When an electric field is imposed on the elements, deformation of the elements imposes a force perpendicular to the sides of the slot, deforming the stator. Appropriate frequency and phase-shifting of the electric field will produce a wave in the stator and motion in a rotor. In a preferred aspect, the piezoelectric elements are configured so that deformation of the elements in the direction of an imposed electric field, generally referred to as the d.sub.33 direction, is utilized to produce wave motion in the stator. In a further aspect, the elements are compressed into the slots so as to minimize tensile stresses on the elements in use.

  18. Piezoelectric wave motor

    DOEpatents

    Yerganian, Simon Scott

    2001-07-17

    A piezoelectric motor having a stator in which piezoelectric elements are contained in slots formed in the stator transverse to the desired wave motion. When an electric field is imposed on the elements, deformation of the elements imposes a force perpendicular to the sides of the slot, deforming the stator. Appropriate frequency and phase shifting of the electric field will produce a wave in the stator and motion in a rotor. In a preferred aspect, the piezoelectric elements are configured so that deformation of the elements in direction of an imposed electric field, generally referred to as the d.sub.33 direction, is utilized to produce wave motion in the stator. In a further aspect, the elements are compressed into the slots so as to minimize tensile stresses on the elements in use.

  19. Magneto-resistance, magneto-caloric and bolometric properties in Pr2/3Sr1/3MnO3:PdO composites near room temperature

    NASA Astrophysics Data System (ADS)

    Bhatt, Ramesh Chandra; Srivastava, P. C.; Awana, V. P. S.; Kishan, H.; Agarwal, S. K.

    2014-09-01

    Temperature coefficient of resistance (TCR), magneto-resistance (MR) and magneto-caloric properties of polycrystalline pristine Pr2/3Sr1/3MnO3 (PSMO) and its composites with PdO (10-30 mole %) (PSMO:Pd) have been studied. Rietveld refinement of their x-ray diffraction (XRD) patterns confirms their single phase crystalline structure with orthorhombic Pbnm space group and Pd appears in pure metallic phase. Of the various composites investigated, PSMO:Pd30 composite exhibits significant TCR of 9.7% K-1 (at 281 K) and low field MR value of 33.5% (H = 1 T). Magnetic entropy change (ΔSM) has been found to be 3.5 J kg-1K-1 (1 T), 6.3 J kg-1K-1 (2 T) and 8.7 J kg-1K-1 (3 T) at 283 K for PSMO:Pd10 sample which show a decreasing trend with increasing Pd content. Present investigations reveal excellent characteristics for bolometric, magnetic sensing and magnetic refrigerating applications near room temperature by PSMO:Pd composites.

  20. Piezoelectric allostery of protein

    NASA Astrophysics Data System (ADS)

    Ohnuki, Jun; Sato, Takato; Takano, Mitsunori

    2016-07-01

    Allostery is indispensable for a protein to work, where a locally applied stimulus is transmitted to a distant part of the molecule. While the allostery due to chemical stimuli such as ligand binding has long been studied, the growing interest in mechanobiology prompts the study of the mechanically stimulated allostery, the physical mechanism of which has not been established. By molecular dynamics simulation of a motor protein myosin, we found that a locally applied mechanical stimulus induces electrostatic potential change at distant regions, just like the piezoelectricity. This novel allosteric mechanism, "piezoelectric allostery", should be of particularly high value for mechanosensor/transducer proteins.

  1. Switching of the photonic band gap in three-dimensional film photonic crystals based on opal-VO{sub 2} composites in the 1.3-1.6 {mu}m spectral range

    SciTech Connect

    Pevtsov, A. B. Grudinkin, S. A.; Poddubny, A. N.; Kaplan, S. F.; Kurdyukov, D. A.; Golubev, V. G.

    2010-12-15

    The parameters of three-dimensional photonic crystals based on opal-VO{sub 2} composite films in the 1.3-1.6 {mu}m spectral range important for practical applications (Telecom standard) are numerically calculated. For opal pores, the range of filling factors is established (0.25-0.6) wherein the composite exhibits the properties of a three-dimensional insulator photonic crystal. On the basis of the opal-VO{sub 2} composites, three-dimensional photonic film crystals are synthesized with specified parameters that provide a maximum shift of the photonic band gap in the vicinity of the wavelength {approx}1.5 {mu}m ({approx}170 meV) at the semiconductor-metal transition in VO{sub 2}.

  2. Monitoring of acoustic emission activity using thin wafer piezoelectric sensors

    NASA Astrophysics Data System (ADS)

    Trujillo, Blaine; Zagrai, Andrei; Meisner, Daniel; Momeni, Sepand

    2014-03-01

    Acoustic emission (AE) is a well-known technique for monitoring onset and propagation of material damage. The technique has demonstrated utility in assessment of metallic and composite materials in applications ranging from civil structures to aerospace vehicles. While over the course of few decades AE hardware has changed dramatically with the sensors experiencing little changes. A traditional acoustic emission sensor solution utilizes a thickness resonance of the internal piezoelectric element which, coupled with internal amplification circuit, results in relatively large sensor footprint. Thin wafer piezoelectric sensors are small and unobtrusive, but they have seen limited AE applications due to low signal-to-noise ratio and other operation difficulties. In this contribution, issues and possible solutions pertaining to the utility of thin wafer piezoelectrics as AE sensors are discussed. Results of AE monitoring of fatigue damage using thin wafer piezoelectric and conventional AE sensors are presented.

  3. UHV piezoelectric translator

    SciTech Connect

    Oversluizen, T.; Watson, G.

    1985-01-01

    A UHV compatible piezoelectric translator has been developed to correct for angular misalignments in the crysals of a UHV x-ray monochromator. The unit is small, bakeable to 150/sup 0/C, and uses only ceramic materials for insulation. We report on the construction details, vacuum compatibility, mechanical properties, and uses of the device.

  4. Piezoelectric actuator renaissance

    NASA Astrophysics Data System (ADS)

    Uchino, Kenji

    2015-03-01

    This paper resumes the content of the invited talk of the author, read at the occasion of the International Workshop on Relaxor Ferroelectrics, IWRF 14, held on October 12-16, 2014 in Stirin, Czech Republic. It reviews the recent advances in materials, designing concepts, and new applications of piezoelectric actuators, as well as the future perspectives of this area.

  5. 1,3-Dichlorobenzene

    Integrated Risk Information System (IRIS)

    1,3 - Dichlorobenzene ; CASRN 541 - 73 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinog

  6. 1,3-Dichloropropene

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 00 / 001 TOXICOLOGICAL REVIEW OF 1,3 - DICHLOROPROPENE ( CAS No . 542 - 75 - 6 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) May 2000 U.S . Environmental Protection Agency Washington , DC DISCLAIMER This document has been reviewed in accordanc

  7. 1,3-Butadiene

    Integrated Risk Information System (IRIS)

    1,3 - Butadiene ; CASRN 106 - 99 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  8. Significant reduction of equivalent magnetic noise by in-plane series connection in magnetoelectric Metglas/Mn-doped Pb(Mg1/3Nb2/3)O3-PbTiO3 laminate composites

    NASA Astrophysics Data System (ADS)

    Fang, Cong; Jiao, Jie; Ma, Jiashuai; Lin, Di; Xu, Haiqing; Zhao, Xiangyong; Luo, Haosu

    2015-11-01

    In this work, we investigated the magnetoelectric (ME) coefficients and equivalent magnetic noises of Metglas/Mn-doped Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMNT) laminate composites with an in-plane series connected structure. An average-field method as well as a finite element simulation are employed to analyze the variation of the ME coefficients of a number of Mn-doped PMNT fibers (N). Both the theoretical and experimental results verify that the equivalent magnetic noises (EMNs) decrease obviously with an increasing N. Using this structure, the measured EMN of the Metglas/Mn-PMNT composite is as low as 0.87pT/Hz1/2 at 30Hz for N  =  7, which is 1.8 times lower than that for N  =  1. Such a low EMN holds considerable promise for practical ME magnetic sensors.

  9. Piezoelectric and electrostrictive sensors and actuators for adaptive structures and smart materials

    NASA Astrophysics Data System (ADS)

    Cross, L. E.

    Developments in composite materials for piezoelectric sensors are briefly reviewed, and new systems using bias field control of the piezoelectric response in relaxor ferroelectric compositions in the PMN:PT and in the PLZT family materials are discussed. For actuator applications, multilayer actuator materials are evaluated, and possibilities for ultrahigh-strain materials are explored. Attention is also given to the composite systems incorporating both a sensor and a responder in the same material together with active solid state electronics. It is shown that a piezoelectric sensor/actuator system mimics an ultrasoft material for weak AC stress, maintaining the load-bearing capability of a stiff ceramic.

  10. Piezoelectric Resonator with Two Layers

    NASA Technical Reports Server (NTRS)

    Stephanou, Philip J. (Inventor); Black, Justin P. (Inventor)

    2013-01-01

    A piezoelectric resonator device includes: a top electrode layer with a patterned structure, a top piezoelectric layer adjacent to the top layer, a middle metal layer adjacent to the top piezoelectric layer opposite the top layer, a bottom piezoelectric layer adjacent to the middle layer opposite the top piezoelectric layer, and a bottom electrode layer with a patterned structure and adjacent to the bottom piezoelectric layer opposite the middle layer. The top layer includes a first plurality of electrodes inter-digitated with a second plurality of electrodes. A first one of the electrodes in the top layer and a first one of the electrodes in the bottom layer are coupled to a first contact, and a second one of the electrodes in the top layer and a second one of the electrodes in the bottom layer are coupled to a second contact.

  11. Piezoelectric step-motion actuator

    DOEpatents

    Mentesana; Charles P.

    2006-10-10

    A step-motion actuator using piezoelectric material to launch a flight mass which, in turn, actuates a drive pawl to progressively engage and drive a toothed wheel or rod to accomplish stepped motion. Thus, the piezoelectric material converts electrical energy into kinetic energy of the mass, and the drive pawl and toothed wheel or rod convert the kinetic energy of the mass into the desired rotary or linear stepped motion. A compression frame may be secured about the piezoelectric element and adapted to pre-compress the piezoelectric material so as to reduce tensile loads thereon. A return spring may be used to return the mass to its resting position against the compression frame or piezoelectric material following launch. Alternative embodiment are possible, including an alternative first embodiment wherein two masses are launched in substantially different directions, and an alternative second embodiment wherein the mass is eliminated in favor of the piezoelectric material launching itself.

  12. Relaxor-based solid solutions for piezoelectric and electrostrictive applications

    NASA Astrophysics Data System (ADS)

    Alberta, Edward F.

    This thesis explores the dielectric, piezoelectric, and electrostrictive properties of a number of relaxor ferroelectric-based solid solution systems. The components of these solid solution systems have a variety of characteristics ranging from normal- to relaxor- to anti-ferroelectric. Some of the relaxor end-members investigated were Pb(In1/2Nb1/2)O3 [PIN], Pb(In1/2Ta1/2)O3 [PIT], Pb(Sc 1/2Nb1/2)O3 [PSN], Pb(Ni1/3Nb 2/3)O3 [PNN], Pb(Mg1/3Nb2/3)O 3 [PMN], and Pb(Zn1/3Nb2/3)O3 [PZN]. Several of these systems have Curie temperatures [Tc] that are among the highest known for MPB compositions. Some examples are PIN-0.38PT with a Tc of 319°C, PIT-0.38PT with a Tc of 248°C, and PSN 0.42PT with a Tc of 254°C. While these are slightly lower that those of typically found in PZT, the temperature dependence of the piezoelectric properties was found to be minimal. The electromechanical coupling coefficients were largely unchanged upon heating to as high as 150°C. This is approximately equal to the Tc of PMN-PT and PZN-PT and significantly exceeds the generally accepted maximum operating temperature for these materials. Many of the materials studied were found to have very large electromechanical coupling factors and produce extraordinarily high field-induced strains. Both PSN-0.42PT and PNN-0.15PZ-0.34PT were found to produce strain levels of ˜0.30% under unipolar drive with limited hysteresis. Peak-to-peak strain levels of as much as 0.60% were possible under bipolar drive conditions. Both of these MPB compositions had very large piezoelectric properties, with the slightly larger values of d33 = 810pC/N, kp = 0.69, kt = 0.56, and k33 = 0.80 occurring in PNN-PZ-PT. Each of the MPB compositions studied has features that can be exploited for specific applications. The combination of high Tc and coercive field found in both PIN-PT and Bi(Ni1/2T1/2)O3 -PT should allow these materials to be used at high drive levels and/or at high temperatures. The high strain, low hysteresis

  13. Improved Piezoelectric Loudspeakers And Transducers

    NASA Technical Reports Server (NTRS)

    Regan, Curtis Randall; Jalink, Antony; Hellbaum, Richard F.; Rohrbach, Wayne W.

    1995-01-01

    Loudspeakers and related acoustic transducers of improved type feature both light weight and energy efficiency of piezoelectric transducers and mechanical coupling efficiency. Active component of transducer made from wafer of "rainbow" piezoelectric material, ceramic piezoelectric material chemically reduced on one face. Chemical treatment forms wafer into dishlike shallow section of sphere. Both faces then coated with electrically conductive surface layers serving as electrodes. Applications include high-fidelity loudspeakers, and underwater echo ranging devices.

  14. Effect of composition on electrical properties of lead-free Bi{sub 0.5}(Na{sub 0.80}K{sub 0.20}){sub 0.5}TiO{sub 3}-(Ba{sub 0.98}Nd{sub 0.02})TiO{sub 3} piezoelectric ceramics

    SciTech Connect

    Jaita, Pharatree; Watcharapasorn, Anucha; Jiansirisomboon, Sukanda

    2013-07-14

    Lead-free piezoelectric ceramics with the composition of (1-x)Bi{sub 0.5}(Na{sub 0.80}K{sub 0.20}){sub 0.5}TiO{sub 3}-x(Ba{sub 0.98}Nd{sub 0.02})TiO{sub 3} or (1-x) BNKT-xBNdT (with x = 0-0.20 mol fraction) have been synthesized by a conventional mixed-oxide method. The compositional dependence of phase structure and electrical properties of the ceramics were systemically studied. The optimum sintering temperature of all BNKT-BNdT ceramics was found to be 1125 Degree-Sign C. X-ray diffraction pattern suggested that BNdT effectively diffused into BNKT lattice during sintering to form a solid solution with a perovskite structure. Scanning electron micrographs showed a slight reduction of grain size when BNdT was added. It was found that BNKT-0.10BNdT ceramic exhibited optimum electrical properties ({epsilon}{sub r} = 1716, tan{delta} = 0.0701, T{sub c} = 327 Degree-Sign C, and d{sub 33} = 211 pC/N), suggesting that this composition has a potential to be one of a promising lead-free piezoelectric candidate for dielectric and piezoelectric applications.

  15. High Temperature Piezoelectric Drill

    NASA Technical Reports Server (NTRS)

    Bao, Xiaoqi; Bar-Cohen, Yoseph; Sherrit, Stewart; Badescu, Mircea; Shrout, Tom

    2012-01-01

    Venus is one of the planets in the solar systems that are considered for potential future exploration missions. It has extreme environment where the average temperature is 460 deg C and its ambient pressure is about 90 atm. Since the existing actuation technology cannot maintain functionality under the harsh conditions of Venus, it is a challenge to perform sampling and other tasks that require the use of moving parts. Specifically, the currently available electromagnetic actuators are limited in their ability to produce sufficiently high stroke, torque, or force. In contrast, advances in developing electro-mechanical materials (such as piezoelectric and electrostrictive) have enabled potential actuation capabilities that can be used to support such missions. Taking advantage of these materials, we developed a piezoelectric actuated drill that operates at the temperature range up to 500 deg C and the mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) configuration. The detailed results of our study are presented in this paper

  16. Piezoelectrically Actuated Shutter for High Vacuum

    NASA Technical Reports Server (NTRS)

    Thompson, Robert; Klose, Gerhard

    2003-01-01

    A piezoelectrically actuated shutter is undergoing development for use in experiments on laser cooling of atoms. The shutter is required to be compatible with ultrahigh vacuum [pressure of 10(exp -9) torr (.1.3 x 10(exp -7) Pa) or less] and to be capable of performing reliably in the vacuum for at least one year. In operation, the shutter would enable the collection and launch of successive samples of cold atoms and would enable the interrogation of the immediately preceding sample while preventing disturbance of the atoms of that sample by light from the collection region. A major constraint is imposed on the design and operation of the shutter by a requirement that it not generate a magnetic field large enough to perturb an atomic clock. An electromagnetically actuated shutter could satisfy all requirements except this one. Hence, it was decided to use piezoelectric instead of electromagnetic actuation. The shutter (see figure) includes two commercial piezoelectrically driven flexure stages that produce a travel of 0.5 mm. Levers mechanically amplify the travel to the required level of 1 cm. Problems that remained to be addressed at the time of reporting the information for this article included lifetime testing and correction of a tendency for shutter blades to bounce open.

  17. Ground and Flight Test Structural Excitation Using Piezoelectric Actuators

    NASA Technical Reports Server (NTRS)

    Voracek, David F.; Reaves, Mercedes C.; Horta, Lucas G.; Potter, Starr; Richwine, David (Technical Monitor)

    2002-01-01

    A flight flutter experiment at the National Aeronautics and Space Administration (NASA) Dryden Flight Research Center, Edwards, California, used an 18-inch half-span composite model called the Aerostructures Test Wing (ATW). The ATW was mounted on a centerline flight test fixture on the NASA F-15B and used distributed piezoelectric strain actuators for in-flight structural excitation. The main focus of this paper is to investigate the performance of the piezoelectric actuators and test their ability to excite the first-bending and first-torsion modes of the ATW on the ground and in-flight. On the ground, wing response resulting from piezoelectric and impact excitation was recorded and compared. The comparison shows less than a 1-percent difference in modal frequency and a 3-percent increase in damping. A comparison of in-flight response resulting from piezoelectric excitation and atmospheric turbulence shows that the piezoelectric excitation consistently created an increased response in the wing throughout the flight envelope tested. The data also showed that to obtain a good correlation between the piezoelectric input and the wing accelerometer response, the input had to be nearly 3.5 times greater than the turbulence excitation on the wing.

  18. Piezoelectric Pulsed Microjets

    DTIC Science & Technology

    2011-04-29

    hydraulic fluid flow within the cylinder head, and hyperelastic stress-strain behavior of the top diaphragm that is coupled to the hydraulic pressure...displacement due to the form of the hyperelastic constitutive equation used to describe its deformation. The input operator, [B(u)](t), is written as a...piezoelectric response. Based on previous experiments, the nylon polymer deforms with the stack without any significant reduction in stack actuator

  19. Piezoelectrically enhanced photocathode

    NASA Technical Reports Server (NTRS)

    Beach, Robert A. (Inventor); Nikzad, Shouleh (Inventor); Strittmatter, Robert P. (Inventor); Bell, Lloyd Douglas (Inventor)

    2009-01-01

    A photocathode, for generating electrons in response to incident photons in a photodetector, includes a base layer having a first lattice structure and an active layer having a second lattice structure and epitaxially formed on the base layer, the first and second lattice structures being sufficiently different to create a strain in the active layer with a corresponding piezoelectrically induced polarization field in the active layer, the active layer having a band gap energy corresponding to a desired photon energy.

  20. Piezoelectric wind turbine

    NASA Astrophysics Data System (ADS)

    Kishore, Ravi Anant; Priya, Shashank

    2013-03-01

    In past few years, there has been significant focus towards developing small scale renewable energy based power sources for powering wireless sensor nodes in remote locations such as highways and bridges to conduct continuous health monitoring. These prior efforts have led to the development of micro-scale solar modules, hydrogen fuel cells and various vibration based energy harvesters. However, the cost effectiveness, reliability, and practicality of these solutions remain a concern. Harvesting the wind energy using micro-to-small scale wind turbines can be an excellent solution in variety of outdoor scenarios provided they can operate at few miles per hour of wind speed. The conventional electromagnetic generator used in the wind mills always has some cogging torque which restricts their operation above certain cut-in wind speed. This study aims to develop a novel piezoelectric wind turbine that utilizes bimorph actuators for electro-mechanical energy conversion. This device utilizes a Savonius rotor that is connected to a disk having magnets at the periphery. The piezoelectric actuators arranged circumferentially around the disk also have magnets at the tip which interacts with the magnetic field of the rotating disk and produces cyclical deflection. The wind tunnel experiments were conducted between 2-12 mph of wind speeds to characterize and optimize the power output of the wind turbine. Further, testing was conducted in the open environment to quantify the response to random wind gusts. An attempt was made towards integration of the piezoelectric wind turbine with the wireless sensor node.

  1. Hybrid piezoelectric energy harvesting transducer system

    NASA Technical Reports Server (NTRS)

    Xu, Tian-Bing (Inventor); Jiang, Xiaoning (Inventor); Su, Ji (Inventor); Rehrig, Paul W. (Inventor); Hackenberger, Wesley S. (Inventor)

    2008-01-01

    A hybrid piezoelectric energy harvesting transducer system includes: (a) first and second symmetric, pre-curved piezoelectric elements mounted separately on a frame so that their concave major surfaces are positioned opposite to each other; and (b) a linear piezoelectric element mounted separately on the frame and positioned between the pre-curved piezoelectric elements. The pre-curved piezoelectric elements and the linear piezoelectric element are spaced from one another and communicate with energy harvesting circuitry having contact points on the frame. The hybrid piezoelectric energy harvesting transducer system has a higher electromechanical energy conversion efficiency than any known piezoelectric transducer.

  2. Laser tuners using circular piezoelectric benders

    NASA Technical Reports Server (NTRS)

    Mcelroy, J. H.; Thompson, P. E.; Walker, H. E.; Johnson, E. H.; Radecki, D. J.; Reynolds, R. S.

    1975-01-01

    The paper presents the results of an experimental evaluation of a new type of piezoelectric ceramic device designed for use as a laser mirror tuner. Thin plates made from various materials were assembled into a circular bimorph configuration and tested for linearity of movement, maximum travel, and resonant frequency for varying conditions of clamping torque and mirror loading values. Most of the devices tested could accept mirror diameters up to approximately 1.3 cm and maintain a resonant frequency above 2 kHz. Typical mirror translation without measurable tilt was plus or minus 20 micrometers or greater for applied voltages of less than plus or minus 300 V.

  3. Method of Fabricating a Composite Apparatus

    NASA Technical Reports Server (NTRS)

    Wilkie, W. Keats (Inventor); Bryant, Robert G. (Inventor); Fox, Robert L. (Inventor); Hellbaum, Richard F. (Inventor); High, James W. (Inventor); Jalink, Antony, Jr. (Inventor)

    2007-01-01

    A method for fabricating a piezoelectric macro-fiber composite actuator comprises making a piezoelectric fiber sheet by providing a plurality of wafers of piezoelectric material, bonding the wafers together with an adhesive material to from a stack of alternating layers of piezoelectric material and adhesive material, and cutting through the stack in a direction substantially parallel to the thickness of the stack and across the alternating layers of piezoelectric material and adhesive material to provide at least one piezoelectric fiber sheet having two sides comprising a plurality of piezoelectric fibers in juxtaposition to the adhesive material. The method further comprises bonding two electrically conductive films to the two sides of the piezoelectric fiber sheet. At least one conductive film has first and second conductive patterns formed thereon which are electrically isolated from one another and in electrical contact with the piezoelectric fiber sheet.

  4. Geometrically nonlinear behavior of piezoelectric laminated plates

    NASA Astrophysics Data System (ADS)

    Rabinovitch, Oded

    2005-08-01

    The geometrically nonlinear behavior of piezo-laminated plates actuated with isotropic or anisotropic piezoelectric layers is analytically investigated. The analytical model is derived using the variational principle of virtual work along with the lamination and plate theories, the von Karman large displacement and moderate rotation kinematic relations, and the anisotropic piezoelectric constitutive laws. A solution strategy that combines the approach of the method of lines, the advantages of the finite element concept, and the variational formulation is developed. This approach yields a set of nonlinear ordinary differential equations with nonlinear boundary conditions, which are solved using the multiple-shooting method. Convergence and verification of the model are examined through comparison with linear and nonlinear results of other approximation methods. The nonlinear response of two active plate structures is investigated numerically. The first plate is actuated in bending using monolithic piezoceramic layers and the second one is actuated in twist using macro-fiber composites. The results quantitatively reveal the complicated in-plane stress state associated with the piezoelectric actuation and the geometrically nonlinear coupling of the in-plane and out-of-plane responses of the plate. The influence of the nonlinear effects ranges from significant stiffening in certain combinations of electrical loads and boundary conditions to amplifications of the induced deflections in others. The paper closes with a summary and conclusions.

  5. Hybrid Piezoelectric/Fiber-Optic Sensor Sheets

    NASA Technical Reports Server (NTRS)

    Lin, Mark; Qing, Xinlin

    2004-01-01

    Hybrid piezoelectric/fiber-optic (HyPFO) sensor sheets are undergoing development. They are intended for use in nondestructive evaluation and long-term monitoring of the integrity of diverse structures, including aerospace, aeronautical, automotive, and large stationary ones. It is anticipated that the further development and subsequent commercialization of the HyPFO sensor systems will lead to economic benefits in the form of increased safety, reduction of life-cycle costs through real-time structural monitoring, increased structural reliability, reduction of maintenance costs, and increased readiness for service. The concept of a HyPFO sensor sheet is a generalization of the concept of a SMART Layer(TradeMark), which is a patented device that comprises a thin dielectric film containing an embedded network of distributed piezoelectric actuator/sensors. Such a device can be mounted on the surface of a metallic structure or embedded inside a composite-material structure during fabrication of the structure. There is has been substantial interest in incorporating sensors other than piezoelectric ones into SMART Layer(TradeMark) networks: in particular, because of the popularity of the use of fiber-optic sensors for monitoring the "health" of structures in recent years, it was decided to incorporate fiber-optic sensors, giving rise to the concept of HyPFO devices.

  6. Modeling of functionally graded piezoelectric ultrasonic transducers.

    PubMed

    Rubio, Wilfredo Montealegre; Buiochi, Flávio; Adamowski, Julio Cezar; Silva, Emílio Carlos Nelli

    2009-05-01

    The application of functionally graded material (FGM) concept to piezoelectric transducers allows the design of composite transducers without interfaces, due to the continuous change of property values. Thus, large improvements can be achieved, as reduction of stress concentration, increasing of bonding strength, and bandwidth. This work proposes to design and to model FGM piezoelectric transducers and to compare their performance with non-FGM ones. Analytical and finite element (FE) modeling of FGM piezoelectric transducers radiating a plane pressure wave in fluid medium are developed and their results are compared. The ANSYS software is used for the FE modeling. The analytical model is based on FGM-equivalent acoustic transmission-line model, which is implemented using MATLAB software. Two cases are considered: (i) the transducer emits a pressure wave in water and it is composed of a graded piezoceramic disk, and backing and matching layers made of homogeneous materials; (ii) the transducer has no backing and matching layer; in this case, no external load is simulated. Time and frequency pressure responses are obtained through a transient analysis. The material properties are graded along thickness direction. Linear and exponential gradation functions are implemented to illustrate the influence of gradation on the transducer pressure response, electrical impedance, and resonance frequencies.

  7. Piezoelectric and electrostrictive materials for transducer applications

    NASA Astrophysics Data System (ADS)

    Cross, L. E.; Newnham, R. E.; Barsch, G. R.; Biggers, J. V.

    1986-07-01

    On the topic of piezoelectric composites, work over the year has focused primarily upon materials with 0:3 phase connectivity. Using chemically co-precipitated powders with high purity and surface perfection, it has been possible to raise the poling field substantially and realize markedly improved properties in lead titanate based materials. X-ray measurements confirm excellent poling and the dhgh figure of merit of 4200x10 to the minus 15th power sq m/N is comparable to the best NGK materials. Work on fired composites which use a low temperature pre-firing yield materials with high d33 and gh values which pole at low fields. New studies of piezoelectrics generated using paint technology permit surprisingly high powder loading and show promising properties for large area receptors. Modelling studies of Safari type 3:1 and 3:2 composites using finite element methods show excellent agreement with measured properties and provide new insights into complex stress distributions in Holey composites. To explore the possibility of patterning ceramics by semiconductor type techniques, etches have been explored for PZT family materials and photo resist defined structures have been produced. In electrostriction, the basic theoretical work has continued upon CaF2, SrF2 and BaF2. Good agreement is found for calculations of third order elastic constants, and for hydrostatic electrostriction, but Q11 and Q12 show large discrepancies with both theoretical models tried.

  8. Electrical field modification of dynamic magnetic properties in FeCo films grown onto [Pb(Mg1/3Nb2/3)O3]0.68-[PbTiO3]0.32(011) piezoelectric substrates with Ru underlayers

    NASA Astrophysics Data System (ADS)

    Phuoc, Nguyen N.; Ong, C. K.

    2015-06-01

    A detailed investigation of electrical tuning of dynamic magnetization of the FeCo magnetic thin film grown onto a PMN-PT piezoelectric substrate was carried out based on the measurement of the zero-field permeability spectra under the application of a voltage across the thickness of the substrate. The resonance frequency can be tuned from 2.95 GHz to 5.9 GHz upon the application of a voltage on the sample in unpoled state. After poling, the resonance frequency of the sample can be tuned in the range from 4.75 GHz to 5.9 GHz. In addition, it was found that after poling the peak of the permeability spectra is broadened compared to before poling, which can be tentatively attributed to the magnetic anisotropy dispersion arising from the presence of the stress-induced anisotropy. The result is also discussed in conjunction with the angular measurement of the static hysteresis loops of the sample before and after poling.

  9. High sensitivity gravimetric sensor made of carbon fiber epoxy composite on Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystal substrate

    NASA Astrophysics Data System (ADS)

    Huang, Naixing; Lü, Tianquan; Zhang, Rui; Cao, Wenwu

    2013-07-01

    We have derived a general formula for sensitivity optimization of gravimetric sensors and use it to design a high sensitivity gravimetric sensor using unidirectional carbon fiber epoxy composite (CFEC) guiding layer on (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT) single crystal substrate. The normalized maximum sensitivity (|Smf|λ)max exhibits an increasing tendency with the decrease of (h/λ)opt. For the CFEC/[011]c poled PMN-0.29PT sensor configuration with λ = 24 μm, the maximum sensitivity |Smf|max can reach as high as 1230 cm2/g, which is about 3 times that of a traditional SiO2/ST quartz configuration gravimetric sensor.

  10. Control multiple electrocaloric effect peak in Pb(Mg1/3Nb2/3)O3-PbTiO3 by phase composition and crystal orientation

    NASA Astrophysics Data System (ADS)

    Bai, Yang; Wei, De; Qiao, Li-Jie

    2015-11-01

    This paper demonstrates the effect of phase composition and crystal orientation on the electrocaloric effect (ECE) in Pb(Mg1/3Nb2/3)O3-PbTiO3 ceramics and single crystals. The ECE features are closely related to phase diagram. Each ECE peak refers to a transition between rhombohedra, tetragonal, and cubic phases. The samples near morphotropic phase boundary have two ECE peaks corresponding to rhombohedra-tetragonal and tetragonal-cubic transitions, the latter induces large ECE of ΔT = 0.60 K (@20 kV/cm) in ceramics and ΔT = 0.69 K (@10 kV/cm) in <001> single crystal. Different orientations of single crystal change both ECE value and position, where <001>-orientation works for tetragonal-cubic ECE peak and <111>-orientation for rhombohedra-tetragonal peak.

  11. Piezoelectric extraction of ECG signal.

    PubMed

    Ahmad, Mahmoud Al

    2016-11-17

    The monitoring and early detection of abnormalities or variations in the cardiac cycle functionality are very critical practices and have significant impact on the prevention of heart diseases and their associated complications. Currently, in the field of biomedical engineering, there is a growing need for devices capable of measuring and monitoring a wide range of cardiac cycle parameters continuously, effectively and on a real-time basis using easily accessible and reusable probes. In this paper, the revolutionary generation and extraction of the corresponding ECG signal using a piezoelectric transducer as alternative for the ECG will be discussed. The piezoelectric transducer pick up the vibrations from the heart beats and convert them into electrical output signals. To this end, piezoelectric and signal processing techniques were employed to extract the ECG corresponding signal from the piezoelectric output voltage signal. The measured electrode based and the extracted piezoelectric based ECG traces are well corroborated. Their peaks amplitudes and locations are well aligned with each other.

  12. High-temperature piezoelectric sensing.

    PubMed

    Jiang, Xiaoning; Kim, Kyungrim; Zhang, Shujun; Johnson, Joseph; Salazar, Giovanni

    2013-12-20

    Piezoelectric sensing is of increasing interest for high-temperature applications in aerospace, automotive, power plants and material processing due to its low cost, compact sensor size and simple signal conditioning, in comparison with other high-temperature sensing techniques. This paper presented an overview of high-temperature piezoelectric sensing techniques. Firstly, different types of high-temperature piezoelectric single crystals, electrode materials, and their pros and cons are discussed. Secondly, recent work on high-temperature piezoelectric sensors including accelerometer, surface acoustic wave sensor, ultrasound transducer, acoustic emission sensor, gas sensor, and pressure sensor for temperatures up to 1,250 °C were reviewed. Finally, discussions of existing challenges and future work for high-temperature piezoelectric sensing are presented.

  13. Piezoelectric extraction of ECG signal

    NASA Astrophysics Data System (ADS)

    Ahmad, Mahmoud Al

    2016-11-01

    The monitoring and early detection of abnormalities or variations in the cardiac cycle functionality are very critical practices and have significant impact on the prevention of heart diseases and their associated complications. Currently, in the field of biomedical engineering, there is a growing need for devices capable of measuring and monitoring a wide range of cardiac cycle parameters continuously, effectively and on a real-time basis using easily accessible and reusable probes. In this paper, the revolutionary generation and extraction of the corresponding ECG signal using a piezoelectric transducer as alternative for the ECG will be discussed. The piezoelectric transducer pick up the vibrations from the heart beats and convert them into electrical output signals. To this end, piezoelectric and signal processing techniques were employed to extract the ECG corresponding signal from the piezoelectric output voltage signal. The measured electrode based and the extracted piezoelectric based ECG traces are well corroborated. Their peaks amplitudes and locations are well aligned with each other.

  14. A Piezoelectric Shear Stress Sensor

    NASA Technical Reports Server (NTRS)

    Kim, Taeyang; Saini, Aditya; Kim, Jinwook; Gopalarathnam, Ashok; Zhu, Yong; Palmieri, Frank L.; Wohl, Christopher J.; Jiang, Xiaoning

    2016-01-01

    In this paper, a piezoelectric sensor with a floating element was developed for shear stress measurement. The piezoelectric sensor was designed to detect the pure shear stress suppressing effects of normal stress generated from the vortex lift-up by applying opposite poling vectors to the: piezoelectric elements. The sensor was first calibrated in the lab by applying shear forces and it showed high sensitivity to shear stress (=91.3 +/- 2.1 pC/Pa) due to the high piezoelectric coefficients of PMN-33%PT (d31=-1330 pC/N). The sensor also showed almost no sensitivity to normal stress (less than 1.2 pC/Pa) because of the electromechanical symmetry of the device. The usable frequency range of the sensor is 0-800 Hz. Keywords: Piezoelectric sensor, shear stress, floating element, electromechanical symmetry

  15. High-Temperature Piezoelectric Sensing

    PubMed Central

    Jiang, Xiaoning; Kim, Kyungrim; Zhang, Shujun; Johnson, Joseph; Salazar, Giovanni

    2014-01-01

    Piezoelectric sensing is of increasing interest for high-temperature applications in aerospace, automotive, power plants and material processing due to its low cost, compact sensor size and simple signal conditioning, in comparison with other high-temperature sensing techniques. This paper presented an overview of high-temperature piezoelectric sensing techniques. Firstly, different types of high-temperature piezoelectric single crystals, electrode materials, and their pros and cons are discussed. Secondly, recent work on high-temperature piezoelectric sensors including accelerometer, surface acoustic wave sensor, ultrasound transducer, acoustic emission sensor, gas sensor, and pressure sensor for temperatures up to 1,250 °C were reviewed. Finally, discussions of existing challenges and future work for high-temperature piezoelectric sensing are presented. PMID:24361928

  16. Numerical analysis of piezoelectric active repair in the presence of frictional contact conditions.

    PubMed

    Alaimo, Andrea; Milazzo, Alberto; Orlando, Calogero; Messineo, Antonio

    2013-04-02

    The increasing development of smart materials, such as piezoelectric and shape memory alloys, has opened new opportunities for improving repair techniques. Particularly, active repairs, based on the converse piezoelectric effect, can increase the life of a structure by reducing the crack opening. A deep characterization of the electromechanical behavior of delaminated composite structures, actively repaired by piezoelectric patches, can be achieved by considering the adhesive layer between the host structure and the repair and by taking into account the frictional contact between the crack surfaces. In this paper, Boundary Element (BE) analyses performed on delaminated composite structures repaired by active piezoelectric patches are presented. A two-dimensional boundary integral formulation for piezoelectric solids based on the multi-domain technique to model the composite host damaged structures and the bonded piezoelectric patches is employed. An interface spring model is also implemented to take into account the finite stiffness of the bonding layers and to model the frictional contact between the delamination surfaces, by means of an iterative procedure. The effect of the adhesive between the plies of piezoelectric bimorph devices on the electromechanical response is first pointed out for both sensing and actuating behavior. Then, the effect of the frictional contact condition on the fracture mechanics behavior of actively repaired delaminated composite structures is investigated.

  17. Piezo-/dielectric properties of perovskite-structure high-temperature relaxor ferroelectrics: The Pb(Lu{sub 1/2}Nb{sub 1/2})O{sub 3}–Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} ternary ceramics

    SciTech Connect

    Li, Tao; Long, Xifa

    2014-03-01

    Graphical abstract: - Highlights: • Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}-based ternary ferroelectric ceramics were prepared by solid-state synthesis method. • Morphotropic phase boundary region has been determined by XRD, di-/piezoelectric properties. • The compositions near MPB region exhibit excellent piezoelectric properties. - Abstract: A new compositional system of relaxor ferroelectrics was investigated based on the high piezoelectricity Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} ferroelectric perovskite family. Compositions were fabricated near an estimated morphotropic phase boundary (MPB) of the Pb(Lu{sub 1/2}Nb{sub 1/2})O{sub 3}–Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} (PLZNT) ternary system by a two-step synthetic process. Their structures have been analyzed by means of X-ray diffraction technique. On the basis of X-ray powder diffraction, the morphotropic phase boundary (MPB) region for the ternary system was obtained. The Curie temperature T{sub C} of ternary system varied from 240 °C to 330 °C and the coercive fields E{sub c}s > 10 kV/cm. The values of piezoelectric coefficients d{sub 33} vary in the range of 260–450 pC/N with different PZN contents. It is worth noting that the optimum compositions were located at MPB region but near the tetragonal phase. The new PLZNT ceramics exhibit wider range of T{sub C}s and E{sub c}s, making it a promising material for high-powder ultrasound transducers using in a large temperature range.

  18. Equivalent properties of 1-3 piezocomposites made of PMN-PT single crystals for underwater sonar transducers

    NASA Astrophysics Data System (ADS)

    Kim, Jinwook; Roh, Yongrae

    2011-04-01

    The design of a piezocomposite transducer is accomplished by such advanced modeling technique as finite element method (FEM). However, accurate analysis of a 1-3 piezocomposite transducer enforces three dimensional (3D) modeling that requires very finemeshing of the transducer structure, which is frequently over affordable calculation resource capacity. In order to simplify the FEM model for complicated underwater transducers, the 1-3 piezocomposite needs to be simulated with a single phase material of equivalent properties. The 1-3 piezocomposite material in this study is made of the PMN-PT single crystal as the active material and urethane as the matrix material. Theoretical models for the calculation of new material parameters of 1-3 composites having fine lateral periodicity have been derived. For the validation of the equivalent properties, TE (thickness extensional), LE (length extensional), LTE (length thickness extensional), and TS (thickness shear) FEM models have been built to compare the impedance-frequency spectra of the 1-3 composite material and an equivalent material. Through the simulation with the models, all the equivalent elastic, dielectric and piezoelectric constants of the single phase material are determined. Further, 3D and axis-symmetric 2D FEM models of a multi-mode Tonpilz transducer have been constructed with the equivalent material properties. The equivalent material provides a very good correlation between the 2D and 3D transducer models, which is not easily attainable with the full 1-3 piezocomposite model. This result confirms the efficacy of the equivalent material properties of the 1-3 piezocomposites.

  19. Dynamic response of a piezoelectric flapping wing

    NASA Astrophysics Data System (ADS)

    Kumar, Alok; Khandwekar, Gaurang; Venkatesh, S.; Mahapatra, D. R.; Dutta, S.

    2015-03-01

    Piezo-composite membranes have advantages over motorized flapping where frequencies are high and certain coupling between bending and twisting is useful to generate lift and forward flight. We draw examples of fruit fly and bumble bee. Wings with Piezo ceramic PZT coating are realized. The passive mechanical response of the wing is characterized experimentally and validated using finite element simulation. Piezoelectric actuation with uniform electrode coating is characterized and optimal frequencies for flapping are identified. The experimental data are used in an empirical model and advanced ratio for a flapping insect like condition for various angular orientations is estimated.

  20. Flexible piezoelectric PMN-PT nanowire-based nanocomposite and device.

    PubMed

    Xu, Shiyou; Yeh, Yao-wen; Poirier, Gerald; McAlpine, Michael C; Register, Richard A; Yao, Nan

    2013-06-12

    Piezoelectric nanocomposites represent a unique class of materials that synergize the advantageous features of polymers and piezoelectric nanostructures and have attracted extensive attention for the applications of energy harvesting and self-powered sensing recently. Currently, most of the piezoelectric nanocomposites were synthesized using piezoelectric nanostructures with relatively low piezoelectric constants, resulting in lower output currents and lower output voltages. Here, we report a synthesis of piezoelectric (1 - x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) nanowire-based nanocomposite with significantly improved performances for energy harvesting and self-powered sensing. With the high piezoelectric constant (d33) and the unique hierarchical structure of the PMN-PT nanowires, the PMN-PT nanowire-based nanocomposite demonstrated an output voltage up to 7.8 V and an output current up to 2.29 μA (current density of 4.58 μA/cm(2)); this output voltage is more than double that of other reported piezoelectric nanocomposites, and the output current is at least 6 times greater. The PMN-PT nanowire-based nanocomposite also showed a linear relationship of output voltage versus strain with a high sensitivity. The enhanced performance and the flexibility of the PMN-PT nanowire-based nanocomposite make it a promising building block for energy harvesting and self-powered sensing applications.

  1. Development of Multiple-Frequency Ultrasonic Imaging System Using Multiple Resonance Piezoelectric Transducer

    NASA Astrophysics Data System (ADS)

    Akiyama, Iwaki; Yoshizumi, Natsuki; Saito, Shigemi; Wada, Yuji; Koyama, Daisuke; Nakamura, Kentaro

    2012-07-01

    The authors have developed a multiple frequency imaging system using a multiple resonance transducer (MRT) consisting of 1-3 composite materials with a low mechanical quality factor Q bonded together. The MRT has a structure consisting of thin and thick piezoelectric plates, two matching layers, and a backing layer. This makes it possible to obtain B-mode images of satisfactory resolution using ultrasonic pulses owing to their short duration. In this paper, the vibration property of the MRT derived through equivalent-circuit analysis is first shown. By utilizing the result, an MRT capable of transmitting ultrasonic pulses for generation of the images of biological tissues with satisfactory resolution is designed and prototyped. Setting the prototype transducer in the mechanical sector probe of commercial ultrasonic diagnosis equipment, the speckle reduction effect is demonstrated using images of various phantoms to mimic biological tissues and a human thyroid.

  2. Radial Field Piezoelectric Diaphragms

    NASA Technical Reports Server (NTRS)

    Bryant, R. G.; Effinger, R. T., IV; Copeland, B. M., Jr.

    2002-01-01

    A series of active piezoelectric diaphragms were fabricated and patterned with several geometrically defined Inter-Circulating Electrodes "ICE" and Interdigitated Ring Electrodes "ICE". When a voltage potential is applied to the electrodes, the result is a radially distributed electric field that mechanically strains the piezoceramic along the Z-axis (perpendicular to the applied electric field). Unlike other piezoelectric bender actuators, these Radial Field Diaphragms (RFDs) strain concentrically yet afford high displacements (several times that of the equivalent Unimorph) while maintaining a constant circumference. One of the more intriguing aspects is that the radial strain field reverses itself along the radius of the RFD while the tangential strain remains relatively constant. The result is a Z-deflection that has a conical profile. This paper covers the fabrication and characterization of the 5 cm. (2 in.) diaphragms as a function of poling field strength, ceramic thickness, electrode type and line spacing, as well as the surface topography, the resulting strain field and displacement as a function of applied voltage at low frequencies. The unique features of these RFDs include the ability to be clamped about their perimeter with little or no change in displacement, the environmentally insulated packaging, and a highly repeatable fabrication process that uses commodity materials.

  3. Piezoelectric axial flow microvalve

    DOEpatents

    Gemmen, Randall; Thornton, Jimmy; Vipperman, Jeffrey S.; Clark, William W.

    2007-01-09

    This invention is directed to a fuel cell operable with a quantity of fuel and a quantity of an oxidizer to produce electrical power, the fuel cell including a fuel cell body including a labyrinth system structured to permit the fuel and the oxidizer to flow therethrough; at least a first catalyst in fluid communication with the labyrinth; and at least a first microvalve operably disposed within at least a portion of the labyrinth. The microvalve utilizes a deflectable member operable upon the application of a voltage from a voltage source. The microvalve includes an elongated flow channel formed therein and extending substantially longitudinally between the first and second ends to permit substantially longitudinal flow of the fluid therethrough and between the first and second ends; and the deflectable member disposed on the valve body, the deflectable member including at least a first piezoelectric portion that is piezoelectrically operable to deflect the deflectable member between an open position and a closed position upon the application of a voltage, the deflectable member in the closed position being operable to resist the flow of the fluid through the flow channel.

  4. Piezoelectric PMN-PT fibre hydrophone for ultrasonic transducer calibration

    NASA Astrophysics Data System (ADS)

    Lau, S. T.; Lam, K. H.; Chan, H. L. W.; Choy, C. L.; Luo, H. S.; Yin, Q. R.; Yin, Z. W.

    2005-01-01

    A newly developed ceramic fibre hydrophone with an active element as small as 0.25 mm in diameter is described in this work. Lead magnesium niobate-lead titanate (PMN-PT) ceramic fibre with a nominal composition of 0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 was fabricated by an extrusion method. PMN-PT single crystals were ground to a powder form and then mixed with poly(acrylic) acid to form a homogenous slurry. The fibre was extruded by pressing the slurry through a spinneret and then sintering at 1250 °C for crystallization. The electrical characteristics of the PMN-PT fibre were evaluated by measuring the relative permittivity and the impedance spectrum. A piezoelectric PMN-PT fibre hydrophone was fabricated and its sensitivity, angular response, and spatial resolution were evaluated. The fibre hydrophone provides good spatial resolution, angular response and receiving sensitivity.

  5. Shear piezoelectricity in bone at the nanoscale

    NASA Astrophysics Data System (ADS)

    Minary-Jolandan, Majid; Yu, Min-Feng

    2010-10-01

    Recent demonstration of shear piezoelectricity in an isolated collagen fibril, which is the origin of piezoelectricity in bone, necessitates investigation of shear piezoelectric behavior in bone at the nanoscale. Using high resolution lateral piezoresponse force microcopy (PFM), shear piezoelectricity in a cortical bone sample was studied at the nanoscale. Subfibrillar structure of individual collagen fibrils with a periodicity of 60-70 nm were revealed in PFM map, indicating the direct contribution of collagen fibrils to the shear piezoelectricity of bone.

  6. Design Requirements for Amorphous Piezoelectric Polymers

    NASA Technical Reports Server (NTRS)

    Ounaies, Z.; Young, J. A.; Harrison, J. S.

    1999-01-01

    An overview of the piezoelectric activity in amorphous piezoelectric polymers is presented. The criteria required to render a polymer piezoelectric are discussed. Although piezoelectricity is a coupling between mechanical and electrical properties, most research has concentrated on the electrical properties of potentially piezoelectric polymers. In this work, we present comparative mechanical data as a function of temperature and offer a summary of polarization and electromechanical properties for each of the polymers considered.

  7. Development of a micromachined piezoelectric microphone for aeroacoustics applications.

    PubMed

    Horowitz, Stephen; Nishida, Toshikazu; Cattafesta, Louis; Sheplak, Mark

    2007-12-01

    This paper describes the design, fabrication, and characterization of a bulk-micromachined piezoelectric microphone for aeroacoustic applications. Microphone design was accomplished through a combination of piezoelectric composite plate theory and lumped element modeling. The device consists of a 1.80-mm-diam, 3-microm-thick, silicon diaphragm with a 267-nm-thick ring of piezoelectric material placed near the boundary of the diaphragm to maximize sensitivity. The microphone was fabricated by combining a sol-gel lead zirconate-titanate deposition process on a silicon-on-insulator wafer with deep-reactive ion etching for the diaphragm release. Experimental characterization indicates a sensitivity of 1.66 microVPa, dynamic range greater than six orders of magnitude (35.7-169 dB, re 20 microPa), a capacitance of 10.8 nF, and a resonant frequency of 59.0 kHz.

  8. Switchable static friction of piezoelectric composite—silicon wafer contacts

    NASA Astrophysics Data System (ADS)

    van den Ende, D. A.; Fischer, H. R.; Groen, W. A.; van der Zwaag, S.

    2013-04-01

    The meso-scale surface roughness of piezoelectric fiber composites can be manipulated by applying an electric field to a piezocomposite with a polished surface. In the absence of an applied voltage, the tips of the embedded piezoelectric ceramic fibers are below the surface of the piezocomposite and a silicon wafer counter surface rests solely on the matrix region of the piezocomposite surface. When actuated, the piezoelectric ceramic fibers protrude from the surface and the wafer rests solely on these protrusions. A threefold decrease in engineering static friction coefficient upon actuation of the piezocomposite was observed: from μ* = 1.65 to μ* = 0.50. These experimental results could be linked to the change in contact surface area and roughness using capillary adhesion theory, which relates the adhesive force to the number and size of the contacting asperities for the different surface states.

  9. A piezoelectric screw dislocation near an elliptical inhomogeneity containing a confocal rigid line

    NASA Astrophysics Data System (ADS)

    Jiang, C. Z.; Zhao, Y. X.; Liu, Y. W.

    2012-09-01

    The interaction between a piezoelectric screw dislocation and an elliptical inhomogeneity in piezoelectric composite material which contains an electrically conductive confocal rigid line is studied, especially analyzing the shielding effect of a piezoelectric screw dislocation near an elliptical inhomogeneity. By applying the complex variable method, the analytical solution to the elastic field and the electric field, the field intensity factors at the tip of the rigid line are derived. The image force acting on the piezoelectric screw dislocation is calculated by using the generalized Peach-Koehler formula. Accordingly, the location and the orientation of the dislocation, the material properties upon the shielding or anti-shielding effect on the stress intensity factors, as well as the effects of the rigid line and the electroelastic properties of the piezoelectric materials on the image force are discussed.

  10. Dielectric Properties of Piezoelectric Polyimides

    NASA Technical Reports Server (NTRS)

    Ounaies, Z.; Young, J. A.; Simpson, J. O.; Farmer, B. L.

    1997-01-01

    Molecular modeling and dielectric measurements are being used to identify mechanisms governing piezoelectric behavior in polyimides such as dipole orientation during poling, as well as degree of piezoelectricity achievable. Molecular modeling on polyimides containing pendant, polar nitrile (CN) groups has been completed to determine their remanent polarization. Experimental investigation of their dielectric properties evaluated as a function of temperature and frequency has substantiated numerical predictions. With this information in hand, we are then able to suggest changes in the molecular structures, which will then improve upon the piezoelectric response.

  11. Novel linear piezoelectric motor for precision position stage

    NASA Astrophysics Data System (ADS)

    Chen, Chao; Shi, Yunlai; Zhang, Jun; Wang, Junshan

    2016-03-01

    Conventional servomotor and stepping motor face challenges in nanometer positioning stages due to the complex structure, motion transformation mechanism, and slow dynamic response, especially directly driven by linear motor. A new butterfly-shaped linear piezoelectric motor for linear motion is presented. A two-degree precision position stage driven by the proposed linear ultrasonic motor possesses a simple and compact configuration, which makes the system obtain shorter driving chain. Firstly, the working principle of the linear ultrasonic motor is analyzed. The oscillation orbits of two driving feet on the stator are produced successively by using the anti-symmetric and symmetric vibration modes of the piezoelectric composite structure, and the slider pressed on the driving feet can be propelled twice in only one vibration cycle. Then with the derivation of the dynamic equation of the piezoelectric actuator and transient response model, start-upstart-up and settling state characteristics of the proposed linear actuator is investigated theoretically and experimentally, and is applicable to evaluate step resolution of the precision platform driven by the actuator. Moreover the structure of the two-degree position stage system is described and a special precision displacement measurement system is built. Finally, the characteristics of the two-degree position stage are studied. In the closed-loop condition the positioning accuracy of plus or minus <0.5 μm is experimentally obtained for the stage propelled by the piezoelectric motor. A precision position stage based the proposed butterfly-shaped linear piezoelectric is theoretically and experimentally investigated.

  12. Piezoelectric rubber films for highly sensitive impact measurement

    NASA Astrophysics Data System (ADS)

    Wang, Jhih-Jhe; Tsai, Jui-Wei; Su, Yu-Chuan

    2013-07-01

    We have successfully demonstrated the microfabrication of piezoelectric rubber films and their application in impact measurement. To realize the desired piezoelectricity and stretchability, cellular polydimethylsiloxane (PDMS) structures with micrometer-sized voids are internally implanted with bipolar charges, which function as dipoles and respond promptly to electromechanical stimuli. In the prototype demonstration, 300 µm thick cellular PDMS films are fabricated and internally coated with a thin polytetrafluoroethylene (PTFE) layer to secure the implanted charges. Meanwhile, the top and bottom surfaces of the cellular PDMS films are deposited with stretchable gold electrodes. An electric field up to 35 MV m-1 is applied across the gold electrodes to ionize the air in the voids and to implant charges on the inner surfaces. The resulting composite structures behave like rubber (with an elastic modulus of about 300 kPa) and show strong piezoelectricity (with a piezoelectric coefficient d33 higher than 1000 pC N-1). While integrated with a wide bandwidth and large dynamic-range charge amplifier, highly sensitive impact measurement (with a stress sensitivity of about 10 mV Pa-1) is demonstrated. As such, the demonstrated piezoelectric rubber films could potentially serve as a sensitive electromechanical material for low-frequency stimuli, and fulfill the needs of a variety of physiological monitoring and wearable electronics applications.

  13. Micromachined Piezoelectric Microspeaker

    NASA Astrophysics Data System (ADS)

    Yi, Seung Hwan; Kim, Eun Sok

    2005-06-01

    A diaphragm-based piezoelectric microspeaker is fabricated on a heavily compressive silicon-nitride film, and is compared to commercial speakers. The largest sound pressure level (SPL) produced by the fabricated microspeaker is 92 dB (when measured 2 mm away from the microspeaker in open field) at around 3 kHz for 6 Vpeak-to-peak input. The microspeaker produces a comparable sound output as a commercial piezo-ceramic and electro-dynamic speaker used in current cellular phones. The keys to this success are as follows: (1) the usage of a diaphragm that has a very high compressive residual stress, high enough to cause the diaphragm to be wrinkled and (2) the usage of high quality ZnO film deposited by two-step deposition technique.

  14. Piezoelectric Rotary Tube Motor

    NASA Technical Reports Server (NTRS)

    Fisher, Charles D.; Badescu, Mircea; Braun, David F.; Culhane, Robert

    2011-01-01

    A custom rotary SQUIGGLE(Registered TradeMark) motor has been developed that sets new benchmarks for small motor size, high position resolution, and high torque without gear reduction. Its capabilities cannot be achieved with conventional electromagnetic motors. It consists of piezoelectric plates mounted on a square flexible tube. The plates are actuated via voltage waveforms 90 out of phase at the resonant frequency of the device to create rotary motion. The motors were incorporated into a two-axis postioner that was designed for fiber-fed spectroscopy for ground-based and space-based projects. The positioner enables large-scale celestial object surveys to take place in a practical amount of time.

  15. Piezoelectric enhancement under negative pressure

    PubMed Central

    Kvasov, Alexander; McGilly, Leo J.; Wang, Jin; Shi, Zhiyong; Sandu, Cosmin S.; Sluka, Tomas; Tagantsev, Alexander K.; Setter, Nava

    2016-01-01

    Enhancement of ferroelectric properties, both spontaneous polarization and Curie temperature under negative pressure had been predicted in the past from first principles and recently confirmed experimentally. In contrast, piezoelectric properties are expected to increase by positive pressure, through polarization rotation. Here we investigate the piezoelectric response of the classical PbTiO3, Pb(Zr,Ti)O3 and BaTiO3 perovskite ferroelectrics under negative pressure from first principles and find significant enhancement. Piezoelectric response is then tested experimentally on free-standing PbTiO3 and Pb(Zr,Ti)O3 nanowires under self-sustained negative pressure, confirming the theoretical prediction. Numerical simulations verify that negative pressure in nanowires is the origin of the enhanced electromechanical properties. The results may be useful in the development of highly performing piezoelectrics, including lead-free ones. PMID:27396411

  16. Piezoelectric enhancement under negative pressure

    NASA Astrophysics Data System (ADS)

    Kvasov, Alexander; McGilly, Leo J.; Wang, Jin; Shi, Zhiyong; Sandu, Cosmin S.; Sluka, Tomas; Tagantsev, Alexander K.; Setter, Nava

    2016-07-01

    Enhancement of ferroelectric properties, both spontaneous polarization and Curie temperature under negative pressure had been predicted in the past from first principles and recently confirmed experimentally. In contrast, piezoelectric properties are expected to increase by positive pressure, through polarization rotation. Here we investigate the piezoelectric response of the classical PbTiO3, Pb(Zr,Ti)O3 and BaTiO3 perovskite ferroelectrics under negative pressure from first principles and find significant enhancement. Piezoelectric response is then tested experimentally on free-standing PbTiO3 and Pb(Zr,Ti)O3 nanowires under self-sustained negative pressure, confirming the theoretical prediction. Numerical simulations verify that negative pressure in nanowires is the origin of the enhanced electromechanical properties. The results may be useful in the development of highly performing piezoelectrics, including lead-free ones.

  17. Structural Origins of Silk Piezoelectricity

    PubMed Central

    Yucel, Tuna; Cebe, Peggy

    2012-01-01

    Uniaxially oriented, piezoelectric silk films were prepared by a two-step method that involved: (1) air drying aqueous, regenerated silk fibroin solutions into films, and (2) drawing the silk films to a desired draw ratio. The utility of two different drawing techniques, zone drawing and water immersion drawing were investigated for processing the silk for piezoelectric studies. Silk films zone drawn to a ratio of λ= 2.7 displayed relatively high dynamic shear piezoelectric coefficients of d14 = −1.5 pC/N, corresponding to over two orders of magnitude increase in d14 due to film drawing. A strong correlation was observed between the increase in the silk II, β-sheet content with increasing draw ratio measured by FTIR spectroscopy (Cβ∝ e2.5 λ), the concomitant increasing degree of orientation of β-sheet crystals detected via WAXD (FWHM = 0.22° for λ= 2.7), and the improvement in silk piezoelectricity (d14∝ e2.4 λ). Water immersion drawing led to a predominantly silk I structure with a low degree of orientation (FWHM = 75°) and a much weaker piezoelectric response compared to zone drawing. Similarly, increasing the β-sheet crystallinity without inducing crystal alignment, e.g. by methanol treatment, did not result in a significant enhancement of silk piezoelectricity. Overall, a combination of a high degree of silk II, β-sheet crystallinity and crystalline orientation are prerequisites for a strong piezoelectric effect in silk. Further understanding of the structural origins of silk piezoelectricity will provide important options for future biotechnological and biomedical applications of this protein. PMID:23335872

  18. Influence of oil composition on the formation of fatty acid esters of 2-chloropropane-1,3-diol (2-MCPD) and 3-chloropropane-1,2-diol (3-MCPD) under conditions simulating oil refining.

    PubMed

    Ermacora, Alessia; Hrncirik, Karel

    2014-10-15

    The toxicological relevance and widespread occurrence of fatty acid esters of 2-chloropropane-1,3-diol (2-MCPD) and 3-chloropropane-1,2-diol (3-MCPD) in refined oils and fats have recently triggered an interest in the mechanism of formation and decomposition of these contaminants during oil processing. In this work, the effect of the main precursors, namely acylglycerols and chlorinated compounds, on the formation yield of MCPD esters was investigated in model systems simulating oil deodorization. The composition of the oils was modified by enzymatic hydrolysis, silica gel purification and application of various refining steps prior to deodorization (namely degumming, neutralization, bleaching). Partial acylglycerols showed greater ability, than did triacylglycerols, to form MCPD esters. However, no direct correlation was found between these two parameters, since the availability of chloride ions was the main limiting factor in the formation reaction. Polar chlorinated compounds were found to be the main chloride donors, although the presence of reactive non-polar chloride-donating species was also observed.

  19. Properties of [Pb(Zn1/3Nb2/3)O3]x- [Pb(Zr0.48Ti0.52)O3](1-x) Ceramics With Low Sintering Temperature and Their 1-3 Piezocomposites.

    PubMed

    Mensur-Alkoy, Ebru; Kaya, Mustafa Yunus; Avdan, Duygu; Alkoy, Sedat

    2016-06-01

    In this paper, dense ( x )PZN-( 1-x )PZT ceramics were prepared at sintering temperatures as low as 950 °C with PZN ratios of x=0.4 , 0.5, and 0.6. The 0.4PZN-0.6PZT composition was found to crystallize in the perovskite phase at this sintering temperature without the presence of any other secondary phases. Higher electrical and electromechanical properties were obtained from the 0.4PZN-0.6PZT composition compared with the x=0.5 and x=0.6 counterparts. Dielectric constant, piezoelectric charge coefficient, electromechanical coupling coefficient, and mechanical quality factor of 0.4PZN-0.6PZT were found to be 2608, 477 pC/N, 64.4, and 65, respectively. While the Curie temperature was 140 °C for pure PZN, the Curie temperature was measured as 300 °C for x=0.4 composition. Green PZN-PZT fibers with circular cross section were drawn using alginate gelation method from the 0.4PZN-0.6PZT composition. Dense fibers were obtained after the sintering process, and piezocomposites were prepared with 1-3 connectivity using fibers with an average diameter of 600 [Formula: see text]. Composites with volume fraction of 20 vol% were investigated for passive acoustic sensor applications. Electrical properties of piezocomposites were found to be scalable and compatible with the electrical properties of the bulk composition. The dielectric constant, piezoelectric charge coefficient, and maximum strain value of the PZN-PZT 1-3 piezocomposite were measured as 345, 165 pC/N, and 0.13%, respectively.

  20. Polycrystalline magnetic garnet films comprising weakly coupled crystallites for piezoelectrically-driven magneto-optic spatial light modulators

    SciTech Connect

    Mito, S.; Sakurai, H.; Takagi, H.; Inoue, M.; Baryshev, A. V.

    2012-04-01

    We have investigated the magnetization process of the polycrystalline magnetic garnet films in order to determine the most suitable composition of garnet films for piezoelectrically-driven magneto-optic spatial light modulators (MOSLMs). For experiment, the bismuth-dysprosium-aluminum-substituted yttrium iron (Bi{sub 1.3}Dy{sub 0.7}Y{sub 1.0}Fe{sub 3.1}Al{sub 1.9}O{sub 12}) garnet films were deposited by an RF magnetron sputter and annealed at 700 deg. C in air. The annealing time was varied in a range of several minutes to control the grain size. The saturation magnetization, the remanent magnetization and the composition of the fabricated garnet films slightly changed versus the annealing time. Experiments showed that the coercivity and the grain size increased at longer annealing; the coercivity was larger for films with bigger grains. This work shows that garnet films with smaller coercivity are most suitable for controlling the magnetization of garnet and, correspondingly, the magneto-optical rotation of MOSLM pixels driven by piezoelectrics.

  1. Piezoelectrically Initiated Pyrotechnic Igniter

    NASA Technical Reports Server (NTRS)

    Quince, Asia; Dutton, Maureen; Hicks, Robert; Burnham, Karen

    2013-01-01

    This innovation consists of a pyrotechnic initiator and piezoelectric initiation system. The device will be capable of being initiated mechanically; resisting initiation by EMF, RF, and EMI (electromagnetic field, radio frequency, and electromagnetic interference, respectively); and initiating in water environments and space environments. Current devices of this nature are initiated by the mechanical action of a firing pin against a primer. Primers historically are prone to failure. These failures are commonly known as misfires or hang-fires. In many cases, the primer shows the dent where the firing pin struck the primer, but the primer failed to fire. In devices such as "T" handles, which are commonly used to initiate the blowout of canopies, loss of function of the device may result in loss of crew. In devices such as flares or smoke generators, failure can result in failure to spot a downed pilot. The piezoelectrically initiated ignition system consists of a pyrotechnic device that plugs into a mechanical system (activator), which on activation, generates a high-voltage spark. The activator, when released, will strike a stack of electrically linked piezo crystals, generating a high-voltage, low-amperage current that is then conducted to the pyro-initiator. Within the initiator, an electrode releases a spark that passes through a pyrotechnic first-fire mixture, causing it to combust. The combustion of the first-fire initiates a primary pyrotechnic or explosive powder. If used in a "T" handle, the primary would ramp the speed of burn up to the speed of sound, generating a shock wave that would cause a high explosive to go "high order." In a flare or smoke generator, the secondary would produce the heat necessary to ignite the pyrotechnic mixture. The piezo activator subsystem is redundant in that a second stack of crystals would be struck at the same time with the same activation force, doubling the probability of a first strike spark generation. If the first

  2. Cryogenic Piezoelectric Actuator

    NASA Technical Reports Server (NTRS)

    Jiang, Xiaoning; Cook, William B.; Hackenberger, Wesley S.

    2009-01-01

    In this paper, PMN-PT single crystal piezoelectric stack actuators and flextensional actuators were designed, prototyped and characterized for space optics applications. Single crystal stack actuators with footprint of 10 mm x10 mm and the height of 50 mm were assembled using 10 mm x10mm x0.15mm PMN-PT plates. These actuators showed stroke > 65 - 85 microns at 150 V at room temperature, and > 30 microns stroke at 77 K. Flextensional actuators with dimension of 10mm x 5 mm x 7.6 mm showed stroke of >50 microns at room temperature at driving voltage of 150 V. A flextensional stack actuator with dimension of 10 mm x 5 mm x 47 mm showed stroke of approx. 285 microns at 150 V at room temperature and > 100 microns at 77K under driving of 150 V should be expected. The large cryogenic stroke and high precision of these actuators are promising for cryogenic optics applications.

  3. Enhanced active piezoelectric 0-3 nanocomposites fabricated through electrospun nanowires

    SciTech Connect

    Feenstra, Joel; Sodano, Henry A.

    2008-06-15

    The use of monolithic piezoceramic materials in sensing and actuation applications has become quite common over the past decade. However, these materials have several properties that limit their application in practical systems. These materials are very brittle due to the ceramic nature of the monolithic material, making them vulnerable to accidental breakage during handling and bonding procedures. In addition, they have very poor ability to conform to curved surfaces and result in large add-on mass associated with using a typically lead-based ceramic. These limitations have motivated the development of alternative methods of applying the piezoceramic material, including piezoceramic fiber composites and piezoelectric 0-3 composites (also known as piezoelectric paint). Piezoelectric paint is desirable because it can be spayed or painted on and can be used with abnormal surfaces. However, the piezoelectric paint developed in prior studies has resulted in low coupling, limiting its application. In order to increase the coupling of the piezoelectric paint, this effort has investigated the use of piezoelectric nanowires rather than spherical piezoelectric particle, which are difficult to strain when embedded in a polymer matrix. The piezoceramic wires were electrospun from a barium titanate (BaTiO{sub 3}) sol gel to produce fibers with 500-1000 nm diameters and subsequently calcinated to acquire perovskite BaTiO{sub 3}. An active nanocomposite paint was formed using the resulting piezoelectric wires and was compared to the same paint with piezoelectric nanoparticles. The results show that the piezoceramic wires produce 0-3 nanocomposites with as high as 300% increase in electromechanical coupling.

  4. Piezoelectric extraction of ECG signal

    PubMed Central

    Ahmad, Mahmoud Al

    2016-01-01

    The monitoring and early detection of abnormalities or variations in the cardiac cycle functionality are very critical practices and have significant impact on the prevention of heart diseases and their associated complications. Currently, in the field of biomedical engineering, there is a growing need for devices capable of measuring and monitoring a wide range of cardiac cycle parameters continuously, effectively and on a real-time basis using easily accessible and reusable probes. In this paper, the revolutionary generation and extraction of the corresponding ECG signal using a piezoelectric transducer as alternative for the ECG will be discussed. The piezoelectric transducer pick up the vibrations from the heart beats and convert them into electrical output signals. To this end, piezoelectric and signal processing techniques were employed to extract the ECG corresponding signal from the piezoelectric output voltage signal. The measured electrode based and the extracted piezoelectric based ECG traces are well corroborated. Their peaks amplitudes and locations are well aligned with each other. PMID:27853180

  5. Radially sandwiched cylindrical piezoelectric transducer

    NASA Astrophysics Data System (ADS)

    Lin, Shuyu; Fu, Zhiqiang; Zhang, Xiaoli; Wang, Yong; Hu, Jing

    2013-01-01

    A new type of radially sandwiched piezoelectric short cylindrical transducer is developed and its radial vibration is studied. The transducer is composed of a solid metal disk, a radially polarized piezoelectric ceramic short tube and a metal tube. The radial vibrations of the solid metal disk, the radially polarized piezoelectric tube and the metal tube are analyzed and their electromechanical equivalent circuits are introduced. Based on the mechanical boundary conditions among the metal disk, the piezoelectric tube and the metal tube, a three-port electromechanical equivalent circuit for the radially sandwiched transducer is obtained and the frequency equation is given. The theoretical relationship of the resonance and anti-resonance frequencies and the effective electromechanical coupling coefficient with the geometrical dimensions is analyzed. The radial vibration of the sandwiched transducer is simulated by using two different numerical methods. It is shown that the analytical resonance and anti-resonance frequencies are in good agreement with the numerically simulated results. The transducer is expected to be used in piezoelectric resonators, actuators and ultrasonic radiators in ultrasonic and underwater sound applications.

  6. Understanding the peculiarities of the piezoelectric effect in macro-porous BaTiO3.

    PubMed

    Roscow, James I; Topolov, Vitaly Yu; Bowen, Christopher R; Taylor, John; Panich, Anatoly E

    2016-01-01

    This work demonstrates the potential of porous BaTiO3 for piezoelectric sensor and energy-harvesting applications by manufacture of materials, detailed characterisation and application of new models. Ferroelectric macro-porous BaTiO3 ceramics for piezoelectric applications are manufactured for a range of relative densities, α = 0.30-0.95, using the burned out polymer spheres method. The piezoelectric activity and relevant parameters for specific applications are interpreted by developing two models: a model of a 3-0 composite and a 'composite in composite' model. The appropriate ranges of relative density for the application of these models to accurately predict piezoelectric properties are examined. The two models are extended to take into account the effect of 90° domain-wall mobility within ceramic grains on the piezoelectric coefficients [Formula: see text]. It is shown that porous ferroelectrics provide a novel route to form materials with large piezoelectric anisotropy [Formula: see text] at 0.20 ≤ α ≤ 0.45 and achieve a high squared figure of merit [Formula: see text] [Formula: see text]. The modelling approach allows a detailed analysis of the relationships between the properties of the monolithic and porous materials for the design of porous structures with optimum properties.

  7. Polymer Piezoelectric Transducers for Ultrasonic NDE

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Xue, Tianji; Lih, Shyh-Shiuh

    1996-01-01

    Piezoelectric polymers are associated with a low noise and inherent damping that makes them very effective receivers as well as broadband transmitters for high frequencies tasks. This paper reviews polymer piezoelectric materials, the origin of their piezoelectric behavior and their applications to ultrasonic NDE.

  8. High Voltage Piezoelectric System for Generating Neutrons

    DTIC Science & Technology

    2013-06-01

    Piezoelectric transformer structural modeling - a review,” Ultrasonics , Ferroelectrics and Frequency Control, IEEE Transactions on, vol. 54, pp...1 High Voltage Piezoelectric System for Generating Neutrons Brady Gall, Student Member, IEEE, Scott D. Kovaleski, Senior Member, IEEE, James A...Compact electrical neutron generators are a desir- able alternative to radioisotope neutron sources. A piezoelectric transformer system is presented

  9. Flexible piezoelectric energy harvesting from jaw movements

    NASA Astrophysics Data System (ADS)

    Delnavaz, Aidin; Voix, Jérémie

    2014-10-01

    Piezoelectric fiber composites (PFC) represent an interesting subset of smart materials that can function as sensor, actuator and energy converter. Despite their excellent potential for energy harvesting, very few PFC mechanisms have been developed to capture the human body power and convert it into an electric current to power wearable electronic devices. This paper provides a proof of concept for a head-mounted device with a PFC chin strap capable of harvesting energy from jaw movements. An electromechanical model based on the bond graph method is developed to predict the power output of the energy harvesting system. The optimum resistance value of the load and the best stretch ratio in the strap are also determined. A prototype was developed and tested and its performances were compared to the analytical model predictions. The proposed piezoelectric strap mechanism can be added to all types of head-mounted devices to power small-scale electronic devices such as hearing aids, electronic hearing protectors and communication earpieces.

  10. Flextensional ultrasonic piezoelectric micro-motor.

    PubMed

    Leinvuo, Joni T; Wilson, Stephen A; Whatmore, Roger W; Cain, Markys G

    2006-12-01

    This paper presents the experimental design, construction, and operational characteristics of a new type of standing wave piezoelectric ultrasonic micro-motor. The motor uses a composite stator, consisting of a metallic flex-tensional mode converter, or "cymbal", bonded to a 2-mm-square piezoelectric plate. The cymbal converts contour-mode vibrations of the plate into oscillations in the cymbal, perpendicular to the stator plane. These are further converted into rotational movement in a rotor pressed against the cymbal by means of an elastic-fin friction drive to produce the required rotary actuation. The motor operates on a single-phase electrical supply, and direct control of the output speed and torque can be achieved by adjusting the amplitude and frequency of the supply voltage. Noncontact optical techniques were used to assess the performance of the developed micro-motor. The operational characteristics were developed from the acceleration and deceleration characteristics. No-load output speed (11 rev s(-1)) and stall torque (27 nNm) were derived using high-speed imaging and image analysis. Maximum efficiency was 0.6%.

  11. Electrochemical characteristics of layered LiNi 1/3Co 1/3Mn 1/3O 2 and with different synthesis conditions

    NASA Astrophysics Data System (ADS)

    He, Ping; Wang, Haoran; Qi, Lu; Osaka, Tetsuya

    LiNi 1/3Mn 1/3Co 1/3O 2 had been successfully prepared from spherical composite carbonate via a simple uniform-phase precipitation method [P. He, H. Wang, L. Qi, T. Osaka, J. Power Sources, in press] at normal pressure, using nickel, cobalt and manganese sulfate and ammonia bicarbonate as reactants. The preparation of spherical composite carbonate was significantly dependant on synthetic condition, such as the reaction temperature, feed rate, molar ratio of these reactants, etc. The optimized condition resulted in spherical composite carbonate of which the particle size distribution was uniform, as observed by scanning electronic microscopy (SEM). Calcination of the uniform composite carbonate with lithium carbonate at high temperature led to a well-ordered layer structured LiNi 1/3Mn 1/3Co 1/3O 2 as confirmed by X-ray diffraction (XRD), without obvious change in shape. Due to the homogeneity of the composite carbonate, the final product, LiNi 1/3Mn 1/3Co 1/3O 2, was also significantly uniform, i.e., the average particle size was of about 10 μm in diameter and the distribution was relatively narrow. As a result, the corresponding tap density was also high, approximately 2.32 g cm -3, of which the value is very near to that of commercialized LiCoO 2. In the voltage range of 2.8-4.2, 2.8-4.35 and 2.8-4.5 V, the discharge capacities of LiNi 1/3Mn 1/3Co 1/3O 2 electrode were 159, 168 and 179 mAh g -1, respectively, with good cyclability.

  12. Piezoelectric Micro- and Nanostructured Fibers Fabricated from Thermoplastic Nanocomposites Using a Fiber Drawing Technique: Comparative Study and Potential Applications.

    PubMed

    Lu, Xin; Qu, Hang; Skorobogatiy, Maksim

    2017-02-28

    We report an all-polymer flexible piezoelectric fiber that uses both judiciously chosen geometry and advanced materials in order to enhance fiber piezoelectric response. The microstructured/nanostructured fiber features a soft hollow polycarbonate core surrounded by a spiral multilayer cladding consisting of alternating layers of piezoelectric nanocomposites (polyvinylidene enhanced with BaTiO3, PZT, or CNT) and conductive polymer (carbon-filled polyethylene). The conductive polymer layers serve as two electrodes, and they also form two spatially offset electric connectors on the fiber surface designed for the ease of connectorization. Kilometer-long piezoelectric fibers of sub-millimeter diameters are thermally drawn from a macroscopic preform. The fibers exhibit high output voltage of up to 6 V under moderate bending, and they show excellent mechanical and electrical durability in a cyclic bend-release test. The micron/nanosize multilayer structure enhances in-fiber poling efficiency due to the small distance between the conducting electrodes sandwiching the piezoelectric composite layers. Additionally, the spiral structure greatly increases the active area of the piezoelectric composite, thus promoting higher voltage generation and resulting in 10-100 higher power generation efficiency over the existing piezoelectric cables. Finally, we weave the fabricated piezoelectric fibers into technical textiles and demonstrate their potential applications in power generation when used as a sound detector, smart car seat upholstery, or wearable materials.

  13. Bending strength of piezoelectric ceramics and single crystals for multifunctional load-bearing applications.

    PubMed

    Anton, Steven R; Erturk, Alper; Inman, Daniel

    2012-06-01

    The topic of multifunctional material systems using active or smart materials has recently gained attention in the research community. Multifunctional piezoelectric systems present the ability to combine multiple functions into a single active piezoelectric element, namely, combining sensing, actuation, or energy conversion ability with load-bearing capacity. Quantification of the bending strength of various piezoelectric materials is, therefore, critical in the development of load-bearing piezoelectric systems. Three-point bend tests are carried out on a variety of piezoelectric ceramics including soft monolithic piezoceramics (PZT-5A and PZT-5H), hard monolithic ceramics (PZT-4 and PZT-8), single-crystal piezoelectrics (PMN-PT and PMN-PZT), and commercially packaged composite devices (which contain active PZT-5A layers). A common 3-point bend test procedure is used throughout the experimental tests. The bending strengths of these materials are found using Euler-Bernoulli beam theory to be 44.9 MPa for PMN-PZT, 60.6 MPa for PMN-PT, 114.8 MPa for PZT- 5H, 123.2 MPa for PZT-4, 127.5 MPa for PZT-8, 140.4 MPa for PZT-5A, and 186.6 MPa for the commercial composite. The high strength of the commercial configuration is a result of the composite structure that allows for shear stresses on the surfaces of the piezoelectric layers, whereas the low strength of the single-crystal materials is due to their unique crystal structure, which allows for rapid propagation of cracks initiating at flaw sites. The experimental bending strength results reported, which are linear estimates without nonlinear ferroelastic considerations, are intended for use in the design of multifunctional piezoelectric systems in which the active device is subjected to bending loads.

  14. Low Voltage Piezoelectric Composite for Transducer Applications

    DTIC Science & Technology

    2005-02-25

    Pillars 10 are supported in 10 panel 20 by insulating material 18. Insulating material 18 can 11 be a dielectric polymer matrix or an elastomeric ...Additionally, the field. 22 impressed on the surface doesn’t couple completely to the 23 internal volume of the active material . 9 1 In view of the above...The active layer of the transducer is either lead 16 zirconium-titanate or lead magnesium-niobate. This material is 17 incorporated in a polymer

  15. Giant piezoelectricity on Si for hyper-active MEMS

    NASA Astrophysics Data System (ADS)

    Eom, Chang-Beom

    2011-03-01

    Smart materials that can sense, manipulate, and position are crucial to the functionality of micro- and nano-machines. Integration of single crystal piezoelectric films on silicon offers the opportunity of high performance piezoelectric microelectromechanical systems (MEMS) incorporating all the advantages of large scale integration on silicon substrates with on-board electronic circuits, improving performance and eliminating common failure points associated with heterogeneous integration. We have fabricated oxide heterostructures with the highest piezoelectric coefficients and figure of merit for piezoelectric energy harvesting system ever realized on silicon substrates by synthesizing epitaxial thin films of Pb(Mg 1/3 Nb 2/3) O3 - PbTi O3 (PMN-PT) on vicinal (001) Si wafers using an epitaxial (001) SrTi O3 template layer. We have also demonstrated fabrication of PMN-PT cantilevers, whose mechanical behavior is consistent with theoretical calculations using the material constants of a bulk PMN-PT single crystal. These epitaxial heterostructures with giant piezoelectricity can be used for MEMS or NEMS devices that function with low drive voltage such as transducers for ultrasound medical imaging, micro-fluidic control and energy harvesting. Beyond electromechanical devices, our approach will open a new avenue to tune and modulate the properties of other multifunctional materials by dynamic strain control. This work was done in collaboration with S. H. Baek, J. Park, D. M. Kim, V. Aksyuk, R. R. Das, S. D. Bu, D. A. Felker, J. Lettieri, V. Vaithyanathan, S. S. N. Bharadwaja, N. Bassiri-Gharb, Y. B. Chen, H. P. Sun, H. W. Jang, D. J. Kreft, S. K. Streiffer, R. Ramesh, X. Q. Pan, S. Trolier-McKinstry, D. G. Schlom, M. S. Rzchowski, R. Blick. This work was supported by the National Science Foundation through grants ECCS-0708759.

  16. Subterahertz excitations and magnetoelectric effects in hexaferrite-piezoelectric bilayers

    SciTech Connect

    Ustinov, Alexey B.; Srinivasan, G.

    2008-10-06

    A frequency-agile hexaferrite-piezoelectric composite for potential device applications at subterahertz frequencies is studied. The bilayer is composed of aluminum substituted barium hexagonal ferrite (BaAl{sub 2}Fe{sub 10}O{sub 19}) and lead zirconate titanate (PZT). A dc electric field applied to PZT results in mechanical deformation of the ferrite, leading to a frequency shift in ferromagnetic resonance. The bilayer demonstrates magnetoelectric interaction coefficient of about 0.37 Oe cm/kV.

  17. Tonpilz Underwater Acoustic Transducer Integrating Lead-free Piezoelectric Material

    NASA Astrophysics Data System (ADS)

    Rouffaud, Rémi; Granger, Christian; Hladky-Hennion, Anne-Christine; Thi, Mai Pham; Levassort, Franck

    A Tonpilz transducer based on lead-free piezoelectric material was fabricated, modeled and characterized. The stack is composed of two rings of doped BaTiO3. This composition was initially chosen due to good electromechanical performance (kt at 40%) and high mechanical quality factor (Qm over 500). Comparison of the displacement at the center of the head mass was performed with a PZT-based Tonpilz with the same design for a center frequency at 22 kHz.

  18. Layerwise Finite Elements for Smart Piezoceramic Composite Plates in Thermal Environments

    NASA Technical Reports Server (NTRS)

    Saravanos, Dimitris A.; Lee, Ho-Jun

    1996-01-01

    Analytical formulations are presented which account for the coupled mechanical, electrical, and thermal response of piezoelectric composite laminates and plate structures. A layerwise theory is formulated with the inherent capability to explicitly model the active and sensory response of piezoelectric composite plates having arbitrary laminate configurations in thermal environments. Finite element equations are derived and implemented for a bilinear 4-noded plate element. Application cases demonstrate the capability to manage thermally induced bending and twisting deformations in symmetric and antisymmetric composite plates with piezoelectric actuators, and show the corresponding electrical response of distributed piezoelectric sensors. Finally, the resultant stresses in the thermal piezoelectric composite laminates are investigated.

  19. Piezoelectric Actuator/Sensor Technology at Rockwell

    NASA Technical Reports Server (NTRS)

    Neurgaonkar, Ratnakar R.

    1996-01-01

    We describe the state-of-the art of piezoelectric materials based on perovskite and tungsten bronze families for sensor, actuator and smart structure applications. The microstructural defects in these materials have been eliminated to a large extent and the resulting materials exhibit exceedingly high performance for various applications. The performance of Rockwell actuators/sensors is at least 3 times better than commercially available products. These high performance actuators are being incorporated into various applications including, DOD, NASA and commercial. The multilayer actuator stacks fabricated from our piezoceramics are advantageous for sensing and high capacitance applications. In this presentation, we will describe the use of our high performance piezo-ceramics for actuators and sensors, including multilayer stacks and composite structures.

  20. Understanding the peculiarities of the piezoelectric effect in macro-porous BaTiO3

    PubMed Central

    Roscow, James I.; Topolov, Vitaly Yu.; Bowen, Christopher R.; Taylor, John; Panich, Anatoly E.

    2016-01-01

    Abstract This work demonstrates the potential of porous BaTiO3 for piezoelectric sensor and energy-harvesting applications by manufacture of materials, detailed characterisation and application of new models. Ferroelectric macro-porous BaTiO3 ceramics for piezoelectric applications are manufactured for a range of relative densities, α = 0.30–0.95, using the burned out polymer spheres method. The piezoelectric activity and relevant parameters for specific applications are interpreted by developing two models: a model of a 3–0 composite and a ‘composite in composite’ model. The appropriate ranges of relative density for the application of these models to accurately predict piezoelectric properties are examined. The two models are extended to take into account the effect of 90° domain-wall mobility within ceramic grains on the piezoelectric coefficients d3j*. It is shown that porous ferroelectrics provide a novel route to form materials with large piezoelectric anisotropy d33*d31*>>1 at 0.20 ≤ α ≤ 0.45 and achieve a high squared figure of merit d33* g33*. The modelling approach allows a detailed analysis of the relationships between the properties of the monolithic and porous materials for the design of porous structures with optimum properties. PMID:27933117

  1. Conception of the system for traffic measurements based on piezoelectric foils

    NASA Astrophysics Data System (ADS)

    Płaczek, M.

    2016-08-01

    A concept of mechatronic system for traffic measurements based on the piezoelectric transducers used as sensors is presented. The aim of the work project is to theoretically and experimentally analyse the dynamic response of road infrastructure forced by vehicles motion. The subject of the project is therefore on the borderline of civil engineering and mechanical and covers a wide range of issues in both these areas. To measure the dynamic response of the tested pieces of road infrastructure application of piezoelectric, in particular piezoelectric transducers in the form of piezoelectric films (MFC - Macro Fiber Composite) is proposed. The purpose is to verify the possibility to use composite piezoelectric transducers as sensors used in traffic surveillance systems - innovative methods of controlling the road infrastructure and traffic. Presented paper reports works that were done in order to receive the basic information about analysed systems and their behaviour under excitation by passing vehicles. It is very important to verify if such kind of systems can be controlled by the analysis of the dynamic response of road infrastructure measured using piezoelectric transducers. Obtained results show that it could be possible.

  2. Lead-Free Piezoelectric Diaphragm Biosensors Based on Micro-Machining Technology and Chemical Solution Deposition

    PubMed Central

    Li, Xiaomeng; Wu, Xiaoqing; Shi, Peng; Ye, Zuo-Guang

    2016-01-01

    In this paper, we present a new approach to the fabrication of integrated silicon-based piezoelectric diaphragm-type biosensors by using sodium potassium niobate-silver niobate (0.82KNN-0.18AN) composite lead-free thin film as the piezoelectric layer. The piezoelectric diaphragms were designed and fabricated by micro-machining technology and chemical solution deposition. The fabricated device was very sensitive to the mass changes caused by various targets attached on the surface of diaphragm. The measured mass sensitivity value was about 931 Hz/μg. Its good performance shows that the piezoelectric diaphragm biosensor can be used as a cost-effective platform for nucleic acid testing. PMID:26771617

  3. Lead-Free Piezoelectric Diaphragm Biosensors Based on Micro-Machining Technology and Chemical Solution Deposition.

    PubMed

    Li, Xiaomeng; Wu, Xiaoqing; Shi, Peng; Ye, Zuo-Guang

    2016-01-12

    In this paper, we present a new approach to the fabrication of integrated silicon-based piezoelectric diaphragm-type biosensors by using sodium potassium niobate-silver niobate (0.82KNN-0.18AN) composite lead-free thin film as the piezoelectric layer. The piezoelectric diaphragms were designed and fabricated by micro-machining technology and chemical solution deposition. The fabricated device was very sensitive to the mass changes caused by various targets attached on the surface of diaphragm. The measured mass sensitivity value was about 931 Hz/μg. Its good performance shows that the piezoelectric diaphragm biosensor can be used as a cost-effective platform for nucleic acid testing.

  4. Piezoelectric measurement of laser power

    DOEpatents

    Deason, Vance A.; Johnson, John A.; Telschow, Kenneth L.

    1991-01-01

    A method for measuring the energy of individual laser pulses or a series of laser pulses by reading the output of a piezoelectric (PZ) transducer which has received a known fraction of the total laser pulse beam. An apparatus is disclosed that reduces the incident energy on the PZ transducer by means of a beam splitter placed in the beam of the laser pulses.

  5. Circuit for Driving Piezoelectric Transducers

    NASA Technical Reports Server (NTRS)

    Randall, David P.; Chapsky, Jacob

    2009-01-01

    The figure schematically depicts an oscillator circuit for driving a piezoelectric transducer to excite vibrations in a mechanical structure. The circuit was designed and built to satisfy application-specific requirements to drive a selected one of 16 such transducers at a regulated amplitude and frequency chosen to optimize the amount of work performed by the transducer and to compensate for both (1) temporal variations of the resonance frequency and damping time of each transducer and (2) initially unknown differences among the resonance frequencies and damping times of different transducers. In other words, the circuit is designed to adjust itself to optimize the performance of whichever transducer is selected at any given time. The basic design concept may be adaptable to other applications that involve the use of piezoelectric transducers in ultrasonic cleaners and other apparatuses in which high-frequency mechanical drives are utilized. This circuit includes three resistor-capacitor networks that, together with the selected piezoelectric transducer, constitute a band-pass filter having a peak response at a frequency of about 2 kHz, which is approximately the resonance frequency of the piezoelectric transducers. Gain for generating oscillations is provided by a power hybrid operational amplifier (U1). A junction field-effect transistor (Q1) in combination with a resistor (R4) is used as a voltage-variable resistor to control the magnitude of the oscillation. The voltage-variable resistor is part of a feedback control loop: Part of the output of the oscillator is rectified and filtered for use as a slow negative feedback to the gate of Q1 to keep the output amplitude constant. The response of this control loop is much slower than 2 kHz and, therefore, does not introduce significant distortion of the oscillator output, which is a fairly clean sine wave. The positive AC feedback needed to sustain oscillations is derived from sampling the current through the

  6. Optimal placement of piezoelectric plates for active vibration control of gas turbine blades: experimental results

    NASA Astrophysics Data System (ADS)

    Botta, F.; Marx, N.; Gentili, S.; Schwingshackl, C. W.; Di Mare, L.; Cerri, G.; Dini, D.

    2012-04-01

    It is well known that the gas turbine blade vibrations can give rise to catastrophic failures and a reduction of the blades life because of fatigue related phenomena[1]-[3] . In last two decades, the adoption of piezoelectric elements, has received considerable attention by many researcher for its potential applicability to different areas of mechanical, aerospace, aeronautical and civil engineering. Recently, a number of studies of blades vibration control via piezoelectric plates and patches have been reported[4]-[6] . It was reported that the use of piezoelectric elements can be very effective in actively controlling vibrations. In one of their previous contributions[7] , the authors of the present manuscript studied a model to control the blade vibrations by piezoelectric elements and validated their results using a multi-physics finite elements package (COMSOL) and results from the literature. An optimal placement method of piezoelectric plate has been developed and applied to different loading scenarios for realistic configurations encountered in gas turbine blades. It has been demonstrated that the optimal placement depends on the spectrum of the load, so that segmented piezoelectric patches have been considered and, for different loads, an optimal combination of sequential and/or parallel actuation and control of the segments has been studied. In this paper, an experimental investigation carried out by the authors using a simplified beam configuration is reported and discussed. The test results obtained by the investigators are then compared with the numerical predictions [7] .

  7. Virus-based piezoelectric energy generation.

    PubMed

    Lee, Byung Yang; Zhang, Jinxing; Zueger, Chris; Chung, Woo-Jae; Yoo, So Young; Wang, Eddie; Meyer, Joel; Ramesh, Ramamoorthy; Lee, Seung-Wuk

    2012-05-13

    Piezoelectric materials can convert mechanical energy into electrical energy, and piezoelectric devices made of a variety of inorganic materials and organic polymers have been demonstrated. However, synthesizing such materials often requires toxic starting compounds, harsh conditions and/or complex procedures. Previously, it was shown that hierarchically organized natural materials such as bones, collagen fibrils and peptide nanotubes can display piezoelectric properties. Here, we demonstrate that the piezoelectric and liquid-crystalline properties of M13 bacteriophage (phage) can be used to generate electrical energy. Using piezoresponse force microscopy, we characterize the structure-dependent piezoelectric properties of the phage at the molecular level. We then show that self-assembled thin films of phage can exhibit piezoelectric strengths of up to 7.8 pm V(-1). We also demonstrate that it is possible to modulate the dipole strength of the phage, hence tuning the piezoelectric response, by genetically engineering the major coat proteins of the phage. Finally, we develop a phage-based piezoelectric generator that produces up to 6 nA of current and 400 mV of potential and use it to operate a liquid-crystal display. Because biotechnology techniques enable large-scale production of genetically modified phages, phage-based piezoelectric materials potentially offer a simple and environmentally friendly approach to piezoelectric energy generation.

  8. Virus-based piezoelectric energy generation

    NASA Astrophysics Data System (ADS)

    Lee, Byung Yang; Zhang, Jinxing; Zueger, Chris; Chung, Woo-Jae; Yoo, So Young; Wang, Eddie; Meyer, Joel; Ramesh, Ramamoorthy; Lee, Seung-Wuk

    2012-06-01

    Piezoelectric materials can convert mechanical energy into electrical energy, and piezoelectric devices made of a variety of inorganic materials and organic polymers have been demonstrated. However, synthesizing such materials often requires toxic starting compounds, harsh conditions and/or complex procedures. Previously, it was shown that hierarchically organized natural materials such as bones, collagen fibrils and peptide nanotubes can display piezoelectric properties. Here, we demonstrate that the piezoelectric and liquid-crystalline properties of M13 bacteriophage (phage) can be used to generate electrical energy. Using piezoresponse force microscopy, we characterize the structure-dependent piezoelectric properties of the phage at the molecular level. We then show that self-assembled thin films of phage can exhibit piezoelectric strengths of up to 7.8 pm V-1. We also demonstrate that it is possible to modulate the dipole strength of the phage, hence tuning the piezoelectric response, by genetically engineering the major coat proteins of the phage. Finally, we develop a phage-based piezoelectric generator that produces up to 6 nA of current and 400 mV of potential and use it to operate a liquid-crystal display. Because biotechnology techniques enable large-scale production of genetically modified phages, phage-based piezoelectric materials potentially offer a simple and environmentally friendly approach to piezoelectric energy generation.

  9. High-response piezoelectricity modeled quantitatively near a phase boundary

    NASA Astrophysics Data System (ADS)

    Newns, Dennis M.; Kuroda, Marcelo A.; Cipcigan, Flaviu S.; Crain, Jason; Martyna, Glenn J.

    2017-01-01

    Interconversion of mechanical and electrical energy via the piezoelectric effect is fundamental to a wide range of technologies. The discovery in the 1990s of giant piezoelectric responses in certain materials has therefore opened new application spaces, but the origin of these properties remains a challenge to our understanding. A key role is played by the presence of a structural instability in these materials at compositions near the "morphotropic phase boundary" (MPB) where the crystal structure changes abruptly and the electromechanical responses are maximal. Here we formulate a simple, unified theoretical description which accounts for extreme piezoelectric response, its observation at compositions near the MPB, accompanied by ultrahigh dielectric constant and mechanical compliances with rather large anisotropies. The resulting model, based upon a Landau free energy expression, is capable of treating the important domain engineered materials and is found to be predictive while maintaining simplicity. It therefore offers a general and powerful means of accounting for the full set of signature characteristics in these functional materials including volume conserving sum rules and strong substrate clamping effects.

  10. Poling and Depoling Effects on Dielectric Properties and Domain Structures in Relaxor 24Pb(In1/2Nb1/2)O3-46Pb(Mg1/3Nb2/3)O3-30PbTiO3 near a Morphotropic Phase Boundary Composition

    NASA Astrophysics Data System (ADS)

    Hidayah, Nur; Yasuda, Naohiko; Ohwa, Hidehiro; Tachi, Yoshihito; Yamashita, Yohachi; Iwata, Makoto

    2012-09-01

    The temperature dependence of the complex relative permittivity in a relaxor ferroelectric solid solution 24Pb(In1/2Nb1/2)O3-46Pb(Mg1/3Nb2/3)O3-30PbTiO3 (PIN-PMN-PT) crystal poled and depoled was measured from room temperature to 200 °C at various frequencies. The poled sample exhibits transitions from the ferroelectric (FE) phase to the relaxor (RE) phase on heating, and after that, the depoled one exhibits those from the RE phase to the glassy freezing phase on cooling. An RE-type dielectric dispersion with a weak frequency (f) dependence was observed. Such a dielectric dispersion in the RE state was found to be based on tweed domain structures observed by polarization light microscopy (PLM) and piezoelectric force microscopy (PFM) due to the competition between the antiferroelectric (AFE) and FE coupling in the RE state. The temperature dependence of complex permittivity with resonance- and relaxor-type dielectric dispersions in the poled and depoled samples was characterized by hierarchical domain structures.

  11. Thin film bismuth iron oxides useful for piezoelectric devices

    DOEpatents

    Zeches, Robert J.; Martin, Lane W.; Ramesh, Ramamoorthy

    2016-05-31

    The present invention provides for a composition comprising a thin film of BiFeO.sub.3 having a thickness ranging from 20 nm to 300 nm, a first electrode in contact with the BiFeO.sub.3 thin film, and a second electrode in contact with the BiFeO.sub.3 thin film; wherein the first and second electrodes are in electrical communication. The composition is free or essentially free of lead (Pb). The BFO thin film is has the piezoelectric property of changing its volume and/or shape when an electric field is applied to the BFO thin film.

  12. Piezoelectric Power Requirements for Active Vibration Control

    NASA Technical Reports Server (NTRS)

    Brennan, Matthew C.; McGowan, Anna-Maria Rivas

    1997-01-01

    This paper presents a method for predicting the power consumption of piezoelectric actuators utilized for active vibration control. Analytical developments and experimental tests show that the maximum power required to control a structure using surface-bonded piezoelectric actuators is independent of the dynamics between the piezoelectric actuator and the host structure. The results demonstrate that for a perfectly-controlled system, the power consumption is a function of the quantity and type of piezoelectric actuators and the voltage and frequency of the control law output signal. Furthermore, as control effectiveness decreases, the power consumption of the piezoelectric actuators decreases. In addition, experimental results revealed a non-linear behavior in the material properties of piezoelectric actuators. The material non- linearity displayed a significant increase in capacitance with an increase in excitation voltage. Tests show that if the non-linearity of the capacitance was accounted for, a conservative estimate of the power can easily be determined.

  13. Coupled improvement between thermoelectric and piezoelectric materials

    NASA Astrophysics Data System (ADS)

    Montgomery, David; Hewitt, Corey; Dun, Chaochao; Carroll, David

    A novel coupling effect in a thermoelectric and piezoelectric meta-structure is discussed. Thermo-piezoelectric generators (TPEGs) exhibit a synergistic effect that amplifies output voltage, and has been observed to increase piezoelectric voltages over 500% of initial values a time dependent thermoelectric/pyroelectric effect. The resulting improvement in voltage has been observed in carbon nanotubes as well as inorganics such as two-dimensional Bismuth Selenide platelets and Telluride nanorods thin-film thermoelectrics. TPEGs are built by integrating insulating layers of polyvinylidene fluoride (PVDF) piezoelectric films between flexible thin film p-type and n-type thermoelectrics. The physical phenomena arising in the interaction between thermoelectric and piezoelectrics is discussed and a model is presented to quantify the expected coupling voltage as a function of stress, thermal gradient, and different thermoelectric materials. TPEG are ideal to capture waste heat and vibrational energy while creating larger voltages and minimizing space when compared with similar thermoelectric or piezoelectric generators.

  14. 1,3,5-Trinitrobenzene

    Integrated Risk Information System (IRIS)

    1,3,5 - Trinitrobenzene ; CASRN 99 - 35 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcino

  15. Heartbeat detection system using piezoelectric transducer

    NASA Astrophysics Data System (ADS)

    Hamonangan, Yosua; Purnamaningsih, Wigajatri

    2017-02-01

    This paper presents a simple piezoelectric based heartbeat detection system. The signal produced by the piezoelectric will undergo signal conditioning and then converted into digital data by Arduino Nano. Using serial communication, the data will be sent to a computer for display and further analysis. The detection of heartbeat is carried out on three locations; wrist, chest, and diaphragm. From the measurement results, it is shown that the system work best when the piezoelectric is placed on wrist.

  16. Additional Drive Circuitry for Piezoelectric Screw Motors

    NASA Technical Reports Server (NTRS)

    Smythe, Robert; Palmer, Dean; Gursel, Yekta; Reder, Leonard; Savedra, Raymond

    2004-01-01

    Modules of additional drive circuitry have been developed to enhance the functionality of a family of commercially available positioning motors (Picomotor . or equivalent) that provide linear motion controllable, in principle, to within increments .30 nm. A motor of this type includes a piezoelectric actuator that turns a screw. Unlike traditional piezoelectrically actuated mechanisms, a motor of this type does not rely on the piezoelectric transducer to hold position: the screw does not turn except when the drive signal is applied to the actuator.

  17. Circular piezoelectric bender laser tuners

    NASA Technical Reports Server (NTRS)

    Mcelroy, J. H.; Thompson, P. E.; Walker, H. E.; Johnson, E. H.; Radecki, D. J.; Reynolds, R. S.

    1972-01-01

    The circular piezoelectric bender laser tuner to replace conventional laser tuners when mirror diameters up to 0.50 inch are sufficient is described. The circular piezoelectric bender laser tuner offers much higher displacements per applied volt and permits laser control circuits to be fabricated using standard operational amplifiers, rather than the expensive high-voltage amplifiers required by conventional tuners. The cost of the device is more than one order of magnitude lower than conventional tuners and the device is very rugged with all mechanical resonances easily designed to be greater than 3kHz. In addition to its use as a laser frequency tuner, the circular bender tuner should find many applications in interferometers and similar devices.

  18. Piezoelectric Measurement Of Bulk Modulus

    NASA Technical Reports Server (NTRS)

    Butler, Barry L.

    1992-01-01

    In method of measuring bulk modulus of elasticity of elastomeric material, piezoelectric crystals of various sizes and energized by alternating voltage embedded in material. Concept demonstrated in test cell in which piezoelectric crystal mounted either unconstrained or between two rubber pads and connected as actuator in loud-speaker. The 1-in. diameter crystal excited with 24 Vac at 60 Hz. When crystal was unconstrained, it drew current of 0.8 mA. When crystal was constrained between rubber pads, current fell to 0.65 mA. Low current, minimal heating, and absence of arcing makes technique suitable for measurement of bulk moduli of elasticity of flammable or explosive rubbery materials.

  19. Resonant efficiency improvement design of piezoelectric biosensor for bacteria gravimetric sensing.

    PubMed

    Tsai, Jang-Zern; Chen, Ching-Jung; Shie, Dung-Ting; Liu, Jen-Tsai

    2014-01-01

    The piezoelectric biosensor have been widely used in ultra-small mass detection of biomolecular, based on PZT piezoelectric material can create a variety of compositions geometrically; it could widely develop a high-frequency resonator and measure the change of the slightest mass while improve the limited detection simultaneously. Therefore, the piezoelectric biosensor of this study was fabricated by a spin-coating method and backside etching process for improving the characteristic of piezoelectric biosensor. The result exhibited that the 250 μm × 250 μm working size has the most favorable piezoelectric characteristic. The tunability was approximately 38.56 % and it showed that reducing the substrate thickness could obtain a clear resonance signal in a range of 60 to 380 MHz. In theory calculated for gravimetric sensing, it could achieve 0.1 ng sensing sensitivity. In gravimetric sensing, the sensing range was between 50,000~100,000 CFU/ml. Sensing range was lower in clinical urinary tract infection (100,000 CFU/ml), thus demonstrating its usefulness for preventive medicine. It can understand the piezoelectric sensor of this study has potential application in the future for biomedical gravimetric sensing.

  20. A Piezoelectric Cryogenic Heat Switch

    NASA Technical Reports Server (NTRS)

    Jahromi, Amir E.; Sullivan, Dan F.

    2014-01-01

    We have measured the thermal conductance of a mechanical heat switch actuated by a piezoelectric positioner, the PZHS (PieZo electric Heat Switch), at cryogenic temperatures. The thermal conductance of the PZHS was measured between 4 K and 10 K, and on/off conductance ratios greater than 100 were achieved when the positioner applied its maximum force of 8 N. We discuss the advantages of using this system in cryogenic applications, and estimate the ultimate performance of an optimized PZHS.

  1. Elastodynamic Impact into Piezoelectric Media

    DTIC Science & Technology

    2014-09-01

    code, COMSOL Multiphysics. Numerical inverse Laplace transform; modified Dubner-Abate-Crump algorithm; impact boundary condition; FDTD; COMSOL ...code, COMSOL Multiphysics.13 The FDTD code was developed by Raymond A 1 Wildman and the COMSOL simulations were performed by David A Hopkins to compare...jump given by the expression sjump. Figs. 2, 3, and 4 also illustrate solutions to the piezoelectric impact problem using a FDTD method and COMSOL

  2. Polarization and Characterization of Piezoelectric Polymers

    NASA Technical Reports Server (NTRS)

    Bodiford, Hollie N.

    1995-01-01

    Piezoelectric materials exhibit an electrical response, such as voltage or charge, in reaction to a mechanical stimuli. The mechanical stimuli can be force, pressure, light, or heat. Therefore, these materials are excellent sensors for various properties. The major disadvantage of state of the art piezoelectric polymers is their lack of utility at elevated temperatures. The objective of this research is to study the feasibility of inducing piezoelectricity in high performance polymer systems. The three aspects of the research include experimental poling, characterization of the capacitance, and demonstration of the use of a piezoelectric polymer as a speaker.

  3. Analysis of Piezoelectric Structural Sensors with Emergent Computing Techniques

    NASA Technical Reports Server (NTRS)

    Ramers, Douglas L.

    2005-01-01

    The purpose of this project was to try to interpret the results of some tests that were performed earlier this year and to demonstrate a possible use of emergence in computing to solve IVHM problems. The test data used was collected with piezoelectric sensors to detect mechanical changes in structures. This project team was included of Dr. Doug Ramers and Dr. Abdul Jallob of the Summer Faculty Fellowship Program, Arnaldo Colon-Lopez - a student intern from the University of Puerto Rico of Turabo, and John Lassister and Bob Engberg of the Structural and Dynamics Test Group. The tests were performed by Bob Engberg to compare the performance two types of piezoelectric (piezo) sensors, Pb(Zr(sub 1-1)Ti(sub x))O3, which we will label PZT, and Pb(Zn(sub 1/3)Nb(sub 2/3))O3-PbTiO, which we will label SCP. The tests were conducted under varying temperature and pressure conditions. One set of tests was done by varying water pressure inside an aluminum liner covered with carbon-fiber composite layers (a cylindrical "bottle" with domed ends) and the other by varying temperatures down to cryogenic levels on some specially prepared composite panels. This report discusses the data from the pressure study. The study of the temperature results was not completed in time for this report. The particular sensing done with these piezo sensors is accomplished by the sensor generating an controlled vibration that is transmitted into the structure to which the sensor is attached, and the same sensor then responding to the induced vibration of the structure. There is a relationship between the mechanical impedance of the structure and the resulting electrical impedance produced in the in the piezo sensor. The impedance is also a function of the excitation frequency. Changes in the real part of impendance signature relative to an original reference signature indicate a change in the coupled structure that could be the results of damage or strain. The water pressure tests were conducted by

  4. Test/analysis comparison of piezoelectric patch local behavior for vibroacoustic active control application

    NASA Astrophysics Data System (ADS)

    Florens, Corine; Balmes, Etienne; Clero, Franck

    2007-04-01

    To predict the effect of active control on aircraft or helicopter trim panels, made with honeycomb sandwich composite, one approach consists in modeling the panel by Finite Element Method. FEM with shell elements for the laminate and volume elements for the core is classically used in industry; in a previous study the homogenized modeling approach has been validated. The aim of the present paper is to make a test/analysis comparison of the dynamic behavior of a honeycomb core sandwich beam actuated by a piezoelectric patch. More precisely, the behavior in the vicinity of the piezoelectric actuator is characterized, in order to validate the modeling approach of honeycomb sandwich composite equipped with piezoelectric patches.

  5. Theoretical and experimental research on the influence of multiple piezoelectric effects on physical parameters of piezoelectric actuator

    NASA Astrophysics Data System (ADS)

    Shi, Liping; Zhou, Haimin; Huang, Jie; Tan, Jiliang

    2015-04-01

    Compared with the traditional actuator of machinery and electricity, the piezoelectric actuator has the advantages of a compact structure, small volume, no mechanical friction, athermancy and no electromagnetic interference. Therefore, it has high application value in the fields of MEMS, bioengineering, medical science and so on. This article draws conclusions from the influence of multiple piezoelectric effects on the physical parameters (dielectric coefficient, equivalent capacity, energy conversion and piezoelectric coefficient) of piezoelectric actuators. These data from theoretical and experimental research show the following: (1) The rate between the dielectric coefficient of piezoelectric in mechanical freedom and clamping is obtained from the secondary direct piezoelectric effect, which enhances the dielectric property, increases the dielectric coefficient and decreases the coefficient of dielectric isolation; (2) Under external field, En ( ex ) = E 1 , exterior stress T = 0, that is to say, under the boundary condition of mechanical freedom, piezoelectric can store electric energy and elasticity, which obtains power density, elastic density and an electromechanical coupling factor; (3) According to the piezoelectric strain Si ( 1 ) , piezoelectric displacement Dm ( 2 ) and piezoelectric strain Si ( 3 ) of multiple piezoelectric effects, when the dielectric coefficient of the first converse piezoelectric effect ɛ33 is 1326 and the dielectric coefficient of the secondary direct piezoelectric effect increases to 3336, the dielectric coefficient of the ceramic chip increases. When the piezoelectric coefficient of the first converse piezoelectric effect d33 is 595 and the piezoelectric coefficient of the secondary direct piezoelectric effect decreases to 240, the piezoelectric coefficient of the ceramic chip will decrease. It is of major significance both in the applications and in basic theory to research the influence of multiple piezoelectric effects on the

  6. Ferroelectric and Piezoelectric Properties of Blends of Poly(Vinylidene-Trifluoroethylene) and Graft Elastomer

    NASA Technical Reports Server (NTRS)

    Su, J.; Ounaies, Z.; Harrison, J. S.

    1999-01-01

    A piezoelectric polymeric blend system has been developed. The system contains two components: ferroelectric poly(vinylidene-trifluoroethylene) and graft elastomer. The remanent polarization, Pr, and the piezoelectric strain coefficient, d31, of the blends have been studied as a function of relative composition of the two components, temperature and frequency. Both blended copolymer and graft unit in the elastomer contribute to the total crystallinity of the blend-system, and hence to the remanent polarization and piezoelectricity. The piezoelectric strain coefficient, d31, of the blend systems shows dependence on both the remanent polarization and the mechanical stiffness, which in turn are determined by the fraction of the two components in the blends. This mechanism makes it possible for the piezoelectric strain response of the blend to be tailored by adjusting the relative composition. Although Pr of the copolymer is higher than that of the blends, the blend films containing 75 wt.% copolymer exhibit a higher d31 at room temperature, possibly due to their lower modulus. The blend films containing 50 wt.% copolymer exhibit a constant value of d31, from room temperature to 70 C.

  7. Periodical Microstructures Based on Novel Piezoelectric Material for Biomedical Applications

    PubMed Central

    Janusas, Giedrius; Ponelyte, Sigita; Brunius, Alfredas; Guobiene, Asta; Prosycevas, Igoris; Vilkauskas, Andrius; Palevicius, Arvydas

    2015-01-01

    A novel cantilever type piezoelectric sensing element was developed. Cost-effective and simple fabrication design allows the use of this element for various applications in the areas of biomedicine, pharmacy, environmental analysis and biosensing. This paper proposes a novel piezoelectric composite material whose basic element is PZT and a sensing platform where this material was integrated. Results showed that a designed novel cantilever-type element is able to generate a voltage of up to 80 µV at 50 Hz frequency. To use this element for sensing purposes, a four micron periodical microstructure was imprinted. Silver nanoparticles were precipitated on the grating to increase the sensitivity of the designed element, i.e., Surface Plasmon Resonance (SPR) effect appears in the element. To tackle some issues (a lack of sensitivity, signal delays) the element must have certain electronic and optical properties. One possible solution, proposed in this paper, is a combination of piezoelectricity and SPR in a single element. PMID:26694398

  8. Radial growth of zinc oxide nanowire for piezoelectric nanogenerator application

    NASA Astrophysics Data System (ADS)

    Rasouli, Safa

    2017-04-01

    Nano- and micro-self-biased sensors employed environmental harvested energy, which are provided by different methods, such as piezoelectric. Piezoelectric materials are capable of producing electrical energy from environmental mechanical force. In this paper, a radial layer of well-arrayed hexagonal zinc oxide nanowires is grown on carbon fiber substrate using a two-step Chemical deposition method of metal salt growth. The resulted morphology is examined using Field Emission Scanning Electron Microscopy (FESEM) micrographs and X-ray Diffraction (XRD) pattern which indicates the quality and the crystallization order of the samples. In addition, composition of the material is studied using a Fourier Transform Infrared (FTIR) spectroscopy method. The results show that zinc oxide nanowires are well managed in vertical direction on the cylindrical carbon fibers. The hexagonal nanowires are grown with a length from 206 to 286 nm (Nanometer) and the diameter from 75 to 103 nm. The results of FTIR spectroscopy and XRD also illustrate the wurtzite structure of zinc oxide. The synthesized nanowires are then applied in a flexible capacitive piezoelectric nanogenerator consisting of a thin Ag layer as the upper contact and a carbon substrate as the back contact which are separated by a PMMA dielectric film. The output current and voltage are measured by applying a random pulse mechanical force on the upper contact. A maximum voltage and current of 14 mV (millivolt) and 20 nA (nanoampere) are generated at the output of nanogenerator, respectively.

  9. Data-glove-based fuzzy control of piezoelectric forceps actuator

    NASA Astrophysics Data System (ADS)

    Susanto, Ken; Yang, Bingen

    2004-07-01

    This paper discusses a novel concept idea of utilizing smart structure in biomedical, minimum invasive surgery (MIS), MEMS manufacturing assembly line and also as a miniature robotic gripper system. The proposed prototype of a miniature piezoelectric forceps actuator (PFA) is composed of two symmetric slightly curved composite beams which each bonded with piezoelectric ceramic layer. The PFA is an innovative forceps actuator that comes with a data glove. The data glove is simply a custom-made glove with two embedded resistance-bending sensors located on thumb and index fingers. Any users can control opening and closing of the PFA by just wearing the data glove. A thin curved beam theory bonded with piezoelectric ceramic will be derived based on Hamilton's principle and its deflection behavior will be simulated based on distributed transfer function method (DTFM). A feasibility study of simulation open loop data glove-based fuzzy logic controller allows the user to open and close the PFA remotely. The bending movement of the thumb and index finger will be formulated in a table of rules based to produce the necessary output controller gain to control the PFA.

  10. Experiments to Demonstrate Piezoelectric and Pyroelectric Effects

    ERIC Educational Resources Information Center

    Erhart, Jirí

    2013-01-01

    Piezoelectric and pyroelectric materials are used in many current applications. The purpose of this paper is to explain the basic properties of pyroelectric and piezoelectric effects and demonstrate them in simple experiments. Pyroelectricity is presented on lead zirconium titanate (PZT) ceramics as an electric charge generated by the temperature…

  11. Cylinder-shaped ultrasonic motors 4.8 mm in diameter using electroactive piezoelectric materials

    NASA Astrophysics Data System (ADS)

    Luo, Laihui; Zhu, Hua; Zhao, Chunsheng; Wang, Haixia; Luo, Haosu

    2007-01-01

    Two cylinder-shaped ultrasonic motors 4.8mm in diameter were developed. This kind of motor was driven by four pieces of piezoelectric materials, which were used to excite the two first-bending vibrations. Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMNT) crystal and Pb(Zr ,Ti)O3 (PZT) ceramic piezoelectric materials were used as drive elements. The motor based on PMNT crystals could operate at a voltage of 25Vp-p (peak to peak). When driven by a 100Vp-p voltage, the motor could run at frequency ranging from 26to68kHz and the revolution speed reached 450rpm. Its maximum output torque was 0.6mNm. The motor based on the PZT ceramic did not exhibit high performance as the PMNT crystal motor. The piezoelectric materials affect the performance of the motors greatly.

  12. Orthotropic Piezoelectricity in 2D Nanocellulose

    NASA Astrophysics Data System (ADS)

    García, Y.; Ruiz-Blanco, Yasser B.; Marrero-Ponce, Yovani; Sotomayor-Torres, C. M.

    2016-10-01

    The control of electromechanical responses within bonding regions is essential to face frontier challenges in nanotechnologies, such as molecular electronics and biotechnology. Here, we present Iβ-nanocellulose as a potentially new orthotropic 2D piezoelectric crystal. The predicted in-layer piezoelectricity is originated on a sui-generis hydrogen bonds pattern. Upon this fact and by using a combination of ab-initio and ad-hoc models, we introduce a description of electrical profiles along chemical bonds. Such developments lead to obtain a rationale for modelling the extended piezoelectric effect originated within bond scales. The order of magnitude estimated for the 2D Iβ-nanocellulose piezoelectric response, ~pm V‑1, ranks this material at the level of currently used piezoelectric energy generators and new artificial 2D designs. Such finding would be crucial for developing alternative materials to drive emerging nanotechnologies.

  13. Orthotropic Piezoelectricity in 2D Nanocellulose

    PubMed Central

    García, Y.; Ruiz-Blanco, Yasser B.; Marrero-Ponce, Yovani; Sotomayor-Torres, C. M.

    2016-01-01

    The control of electromechanical responses within bonding regions is essential to face frontier challenges in nanotechnologies, such as molecular electronics and biotechnology. Here, we present Iβ-nanocellulose as a potentially new orthotropic 2D piezoelectric crystal. The predicted in-layer piezoelectricity is originated on a sui-generis hydrogen bonds pattern. Upon this fact and by using a combination of ab-initio and ad-hoc models, we introduce a description of electrical profiles along chemical bonds. Such developments lead to obtain a rationale for modelling the extended piezoelectric effect originated within bond scales. The order of magnitude estimated for the 2D Iβ-nanocellulose piezoelectric response, ~pm V−1, ranks this material at the level of currently used piezoelectric energy generators and new artificial 2D designs. Such finding would be crucial for developing alternative materials to drive emerging nanotechnologies. PMID:27708364

  14. Orthotropic Piezoelectricity in 2D Nanocellulose.

    PubMed

    García, Y; Ruiz-Blanco, Yasser B; Marrero-Ponce, Yovani; Sotomayor-Torres, C M

    2016-10-06

    The control of electromechanical responses within bonding regions is essential to face frontier challenges in nanotechnologies, such as molecular electronics and biotechnology. Here, we present Iβ-nanocellulose as a potentially new orthotropic 2D piezoelectric crystal. The predicted in-layer piezoelectricity is originated on a sui-generis hydrogen bonds pattern. Upon this fact and by using a combination of ab-initio and ad-hoc models, we introduce a description of electrical profiles along chemical bonds. Such developments lead to obtain a rationale for modelling the extended piezoelectric effect originated within bond scales. The order of magnitude estimated for the 2D Iβ-nanocellulose piezoelectric response, ~pm V(-1), ranks this material at the level of currently used piezoelectric energy generators and new artificial 2D designs. Such finding would be crucial for developing alternative materials to drive emerging nanotechnologies.

  15. Multistage Force Amplification of Piezoelectric Stacks

    NASA Technical Reports Server (NTRS)

    Xu, Tian-Bing (Inventor); Siochi, Emilie J. (Inventor); Zuo, Lei (Inventor); Jiang, Xiaoning (Inventor); Kang, Jin Ho (Inventor)

    2015-01-01

    Embodiments of the disclosure include an apparatus and methods for using a piezoelectric device, that includes an outer flextensional casing, a first cell and a last cell serially coupled to each other and coupled to the outer flextensional casing such that each cell having a flextensional cell structure and each cell receives an input force and provides an output force that is amplified based on the input force. The apparatus further includes a piezoelectric stack coupled to each cell such that the piezoelectric stack of each cell provides piezoelectric energy based on the output force for each cell. Further, the last cell receives an input force that is the output force from the first cell and the last cell provides an output apparatus force In addition, the piezoelectric energy harvested is based on the output apparatus force. Moreover, the apparatus provides displacement based on the output apparatus force.

  16. Integration of encapsulated piezoelectric actuators in highly loaded CFRP structures

    NASA Astrophysics Data System (ADS)

    Bachmann, Florian; Ermanni, Paolo

    2010-04-01

    The present work has been initiated in the frame of the European research project DREAM. Within this highly interdisciplinary project we are focusing on the development and application of vibration damping solutions based on piezoelectric shunt circuits for future aeroelastic applications. The scientific community has put significant effort into the investigation of piezoelectric shunt damping in conjuction with typical engineering test structures such as beams and plates. However, investigations are mainly restricted to surface bonded piezoelectric elements. Commercially available actuators and sensors can be easily bonded to structures using standard epoxy resins. Yet, the structural integration into composite laminates is cumbersome, due to the implications in terms of overall structural integrity and functionality, and due to the problems in achieving a good electrical conductivity, intimate contact betwen electrode and piezoceramic material as well as a perfect isolation from the surrounding host structure. This contribution is concerned with technological aspects related to the integration of piezoceramic actuators into highly loaded CFRP structures. In particular, we present results of a comparative study aiming at the characterization of less invasive electrodes to establish electrical contact between the piezoceramic material and possible shunt circuits. Another drawback of commercial actuators are their limited strain allowables ranging from 0.1% to 0.3% which is not sufficient for high performance lighweight structures. The second part of this contribution is therefore dedicated to the description of a novel prestressing procedure which is used to fabricate actuators that command 170% higher strain allowables than non-prestressed actuators. Mechanical testing of these prestressed actuators are very encouraging, showing high strain allowables, perfect electrical isolation from the host structure, excellent electric contacting of the piezoelectric material

  17. Flutter suppression via piezoelectric actuation

    NASA Technical Reports Server (NTRS)

    Heeg, Jennifer

    1991-01-01

    Experimental flutter results obtained from wind tunnel tests of a two degree of freedom wind tunnel model are presented for the open and closed loop systems. The wind tunnel model is a two degree of freedom system which is actuated by piezoelectric plates configured as bimorphs. The model design was based on finite element structural analyses and flutter analyses. A control law was designed based on a discrete system model; gain feedback of strain measurements was utilized in the control task. The results show a 21 pct. increase in the flutter speed.

  18. A piezoelectric cryogenic heat switch.

    PubMed

    Jahromi, Amir E; Sullivan, Dan F

    2014-06-01

    We have measured the thermal conductance of a mechanical heat switch actuated by a piezoelectric positioner, the PZHS (PieZo electric Heat Switch), at cryogenic temperatures. The thermal conductance of the PZHS was measured between 4 K and 10 K, and on/off conductance ratios of about 100-200 at lowest and highest measures temperature were achieved when the positioner applied its maximum force of 8 N, respectively. We discuss the advantages of using this system in cryogenic applications, and estimate the ultimate performance of an ideal PZHS.

  19. Kinetics of nucleation of thermodynamically ordered ferroelectric phases in PbMg1/3Nb2/3O3- xPbTiO3 crystals with different compositions

    NASA Astrophysics Data System (ADS)

    Kamzina, L. S.

    2016-12-01

    The kinetics of electric field-induced nucleation of ordered ferroelectric phases from a mixed glassy relaxor state has been studied in a number of single-crystal (1- x)PbMg1/3Nb2/3O3- xPbTiO3 (PMN- xPT) solid solutions ( x = 29, 33, 35%) lying in a morphotropic phase region. It is shown that the formation of these phases and fast establishment of a macroscopic polarization are preceded by some delay time, depending on the electric field strength and temperature. It is found that the monoclinic phase is thermodynamically stable at room temperature in all the compounds in the time ( 3000 s) and electric field ( 1 kV/cm) ranges under study, whereas the monoclinic phase of the compound with x = 35% transforms, at temperatures near the temperature of the morphotropic phase transition after insignificant time interval of 100 s, to another stable ferroelectric tetragonal phase.

  20. Ferroelectric, pyroelectric, and piezoelectric properties of a photovoltaic perovskite oxide

    NASA Astrophysics Data System (ADS)

    Bai, Yang; Siponkoski, Tuomo; Peräntie, Jani; Jantunen, Heli; Juuti, Jari

    2017-02-01

    A perovskite solid-solution, (1-x)KNbO3-xBaNi1/2Nb1/2O3-δ (KBNNO), has been found to exhibit tunable bandgaps in the visible light energy range, making it suitable for light absorption and conversion applications, e.g., solar energy harvesting and light sensing. Such a common ABO3-type perovskite structure, most widely used for ferroelectrics and piezoelectrics, enables the same solid-solution material to be used for the simultaneous harvesting or sensing of solar, kinetic, and thermal energies. In this letter, the ferroelectric, pyroelectric, and piezoelectric properties of KBNNO with x = 0.1 have been reported above room temperature. The investigation has also identified the optimal bandgap for visible light absorption. The stoichiometric composition and also a composition with potassium deficiency have been investigated, where the latter has shown more balanced properties. As a result, a remanent polarization of 3.4 μC/cm2, a pyroelectric coefficient of 26 μC/m2 K, piezoelectric coefficients d33 ≈ 23 pC/N and g33 ≈ 4.1 × 10-3 Vm/N, and a direct bandgap of 1.48 eV have been measured for the KBNNO ceramics. These results are considered to be a significant improvement compared to those of other compositions (e.g., ZnO and AlN), which could be used for the same applications. The results pave the way for the development of hybrid energy harvesters/sensors, which can convert multiple energy sources into electrical energy simultaneously in the same material.

  1. Using Diffusion Bonding in Making Piezoelectric Actuators

    NASA Technical Reports Server (NTRS)

    Sager, Frank E.

    2003-01-01

    A technique for the fabrication of piezoelectric actuators that generate acceptably large forces and deflections at relatively low applied voltages involves the stacking and diffusion bonding of multiple thin piezoelectric layers coated with film electrodes. The present technique stands in contrast to an older technique in which the layers are bonded chemically, by use of urethane or epoxy agents. The older chemical-bonding technique entails several disadvantages, including the following: It is difficult to apply the bonding agents to the piezoelectric layers. It is difficult to position the layers accurately and without making mistakes. There is a problem of disposal of hazardous urethane and epoxy wastes. The urethane and epoxy agents are nonpiezoelectric materials. As such, they contribute to the thickness of a piezoelectric laminate without contributing to its performance; conversely, for a given total thickness, the performance of the laminate is below that of a unitary piezoelectric plate of the same thickness. The figure depicts some aspects of the fabrication of a laminated piezoelectric actuator by the present diffusion- bonding technique. First, stock sheets of the piezoelectric material are inspected and tested. Next, the hole pattern shown in the figure is punched into the sheets. Alternatively, if the piezoelectric material is not a polymer, then the holes are punched in thermoplastic films. Then both faces of each punched piezoelectric sheet or thermoplastic film are coated with a silver-ink electrode material by use of a silkscreen printer. The electrode and hole patterns are designed for minimal complexity and minimal waste of material. After a final electrical test, all the coated piezoelectric layers (or piezoelectric layers and coated thermoplastic films) are stacked in an alignment jig, which, in turn, is placed in a curved press for the diffusion-bonding process. In this process, the stack is pressed and heated at a specified curing temperature

  2. Exploratory Study of the Acoustic Performance of Piezoelectric Actuators

    NASA Technical Reports Server (NTRS)

    SantaMaria, O. S.; Thurlow, E. M.; Jones, M. G.

    1989-01-01

    The proposed ducted fan engine has prompted the need for increasingly lightweight and efficient noise control devices. Exploratory tests at the NASA Langley Research Center were conducted to evaluate three piezoelectric specimens as possible control transducers: a Polyvinylidene Flouride (PVDF) piezofilm sample and two composite samples of Lead Zirconate Titanate (PZT) rods embedded in fiberglass. The tests measured the acoustic output efficiency and evaluated the noise control characteristics when interacting with a primary sound source. The results showed that a PZT sample could diminish the reflected acoustic waves. However, the PZT acoustic output must increase by several orders of magnitude to qualify as a control transducer for the ducted fan engine.

  3. Criterion for material selection in design of bulk piezoelectric energy harvesters.

    PubMed

    Priya, Shashank

    2010-12-01

    Vibration energy harvesting has gained tremendous attention in the past decade and continues to grow rapidly. There are various transduction mechanisms for converting the vibration energy into electrical energy, out of which the piezoelectric mechanism has been shown to provide advantages at the micro-to-meso scale. In the past few years, several studies have tried to address the question of which piezoelectric composition is better for energy harvesting; however, discussion on this subject continues. The intent of this letter is to provide an answer for this question through a simple criterion which can be used in routine material evaluation.

  4. Converse magnetoelectric effect in ferromagnetic shape memory alloy/piezoelectric laminate

    NASA Astrophysics Data System (ADS)

    Chen, S. Y.; Wang, D. H.; Han, Z. D.; Zhang, C. L.; Du, Y. W.; Huang, Z. G.

    2009-07-01

    In laminates, the converse magnetoelectric (CME) effect is often achieved by an elastic coupling between magnetostrictive and piezoelectric layers. Here the authors report on an alternative mechanism for obtaining CME. In a transition-metals-based ferromagnetic shape memory alloy/piezoelectric ceramic laminated composite, the stress-induced martensitic transformation is utilized to gain the magnetic changes, which gives rise to a giant CME effect consequently. The strong CME is observed at room temperature over a broad bandwidth, under weak magnetic bias and electric field.

  5. Thermal energy conversion by coupled shape memory and piezoelectric effects

    NASA Astrophysics Data System (ADS)

    Zakharov, Dmitry; Lebedev, Gor; Cugat, Orphee; Delamare, Jerome; Viala, Bernard; Lafont, Thomas; Gimeno, Leticia; Shelyakov, Alexander

    2012-09-01

    This work gives experimental evidence of a promising method of thermal-to-electric energy conversion by coupling shape memory effect (SME) and direct piezoelectric effect (DPE) for harvesting quasi-static ambient temperature variations. Two original prototypes of thermal energy harvesters have been fabricated and tested experimentally. The first is a hybrid laminated composite consisting of TiNiCu shape memory alloy (SMA) and macro fiber composite piezoelectric. This composite comprises 0.1 cm3 of active materials and harvests 75 µJ of energy for each temperature variation of 60 °C. The second prototype is a SME/DPE ‘machine’ which uses the thermally induced linear strains of the SMA to bend a bulk PZT ceramic plate through a specially designed mechanical structure. The SME/DPE ‘machine’ with 0.2 cm3 of active material harvests 90 µJ over a temperature increase of 35 °C (60 µJ when cooling). In contrast to pyroelectric materials, such harvesters are also compatible with both small and slow temperature variations.

  6. Derivation of Piezoelectric Losses from Admittance Spectra

    NASA Astrophysics Data System (ADS)

    Zhuang, Yuan; Ural, Seyit O.; Rajapurkar, Aditya; Tuncdemir, Safakcan; Amin, Ahmed; Uchino, Kenji

    2009-04-01

    High power density piezoelectrics are required to miniaturize devices such as ultrasonic motors, transformers, and sound projectors. The power density is limited by the heat generation in piezoelectrics, therefore, clarification of the loss mechanisms is necessary. This paper provides a methodology to determine the electromechanical losses, i.e., dielectric, elastic and piezoelectric loss factors in piezoelectrics by means of a detailed analysis of the admittance/impedance spectra. This method was applied to determine the piezoelectric losses for lead zirconate titanate ceramics and lead magnesium niobate-lead titanate single crystals. The analytical solution provides a new method for obtaining the piezoelectric loss factor, which is usually neglected in practice by transducer designers. Finite element simulation demonstrated the importance of piezoelectric losses to yield a more accurate fitting to the experimental data. A phenomenological model based on two phase-shifts and the Devonshire theory of a polarizable-deformable insulator is developed to interpret the experimentally observed magnitudes of the mechanical quality factor at resonance and anti-resonance.

  7. FL V1.3

    SciTech Connect

    Rothganger, Frederick

    2009-08-03

    A library of utility classes for computer vision. Contains implementations of various well-known image processing techniques, such as interest point operators and region descriptors. Includes interfaces to various libraries for image and video I/O, as well as an interface to LAPACK/BLAS. FL was developed at the University of Illinois, Urbana-Champaign (UIUC) and released under an open source license. Version 1.2 was a maintenance release provided by SNL under the LGPL license. Version 1.3 is a maintenance release, containing the following changes: - Improved image format handling. Now handles strided and planar memory layouts and a wider range of pixel formats. - Improved image file I/O, including better support for metadata, a wider range of stored pixel types, and a couple of new file formats. - Improvements to DOG and SIFT, and efficiency improvements in low-level convolution. - Improvements to networking, including a generic TCP listener. - Various improvements to numerical processing. The HISTORY file included in the distribution contains a more detailed description of the changes.

  8. Laser stimulated piezoelectricity in Er3+ doped GeO2-Bi2O3 glasses containing silicon nanocrystals

    NASA Astrophysics Data System (ADS)

    Kassab, Luciana Reyes Pires; Camilo, Mauricio Eiji; da Silva, Diego Silverio; de Assumpção, Thiago Alexandre Alves; Fedorchuk, A. O.; Plucinski, K. J.

    2014-12-01

    We report the first observation of the laser stimulated piezoelectricity in Er3+ doped GeO2-Bi2O3 glasses containing silicon nanocrystals, prepared using the simple well known melt quenching technique. Two split beams originated from the same nanosecond lasers were used for the performance of the bicolor laser treatment. The fundamental (λ = 1064 nm) and the doubled frequency (λ = 532 nm) signal of a pulsed nanosecond Nd:YAG laser, as the fundamental (λ = 1540 nm) and the doubled frequency (λ = 770 nm) signal of an Er:glass laser were used. The ratio of power densities between the fundamental and the doubled frequency beams has been varied from 4:1 to 8:1. This value was chosen to achieve the maximum output photoinduced piezoelectric response. The present photoinduced piezoelectricity effect opens a new road for obtaining optically operated piezoelectric devices in germanate composites doped with rare-earth ions.

  9. Self-biased large magnetoelectric coupling in co-sintered Bi{sub 0.5}Na{sub 0.5}TiO{sub 3} based piezoelectric and CoFe{sub 2}O{sub 4} based magnetostrictive bilayered composite

    SciTech Connect

    Kumari, Mukesh; Singh, Amrita; Chatterjee, Ratnamala E-mail: ratnamalac@gmail.com; Gupta, Arti; Prakash, Chandra

    2014-12-28

    In this work, magnetoelectric properties of a co-sintered bilayered composite of non-lead based piezoelectric 0.97(Bi{sub 0.5}Na{sub 0.5}TiO{sub 3})–0.03(K{sub 0.47}Na{sub 0.47}Li{sub 0.06}Nb{sub 0.74}Sb{sub 0.06}Ta{sub 0.2}O{sub 3}) and magnetostrictive Co{sub 0.6}Zn{sub 0.4}Fe{sub 1.7}Mn{sub 0.3}O{sub 4} are presented. Similar optimal sintering conditions of the individual components lead to a very clean interface as evidenced in the scanning electron microscopy, angle dispersive X-ray diffraction, and energy-dispersive X-ray (EDX) results. Clean interface results in strong intimate mechanical coupling between both components and causes a maximum transfer of induced strain, leading to a large magnetoelectric coupling ∼142 mV/cm·Oe measured in longitudinally magnetized-transversely polarized configuration (L-T mode). Remnant polarization ∼32 μC/cm{sup 2}, remnant magnetization ∼0.50 emu/g, and sufficiently high self biased magnetoelectricity ∼135 mV/cm Oe (L-T mode) were observed for this composite.

  10. Tunable Surface and Matrix Chemistries in Optically Printed (0-3) Piezoelectric Nanocomposites.

    PubMed

    Kim, Kanguk; Middlebrook, James L; Chen, Jeffrey E; Zhu, Wei; Chen, Shaochen; Sirbuly, Donald J

    2016-12-14

    In this work, the impacts of varying surface modification, matrix parameters, and fabrication conditions on the performance of optically printed (0-3) piezoelectric polymer nanocomposites are examined. For example, we find that a 75% reduction in nanoparticle edge-length boosted the piezoelectric coefficient (d33) by over 100%. By optimizing the composition and fabrication conditions, 10% by mass loading barium titanate nanocomposites are able to yield d33 values of ∼80 pC/N compared to <5 pC/N when parameters are not optimized. With a more complete understanding of how to enhance the performance of (0-3) piezoelectric polymer nanocomposites, these materials should find use in a wide range of applications.

  11. The nonlinear piezoelectric tuned vibration absorber

    NASA Astrophysics Data System (ADS)

    Soltani, P.; Kerschen, G.

    2015-07-01

    This paper proposes a piezoelectric vibration absorber, termed the nonlinear piezoelectric tuned vibration absorber (NPTVA), for the mitigation of nonlinear resonances of mechanical systems. The new feature of the NPTVA is that its nonlinear restoring force is designed according to a principle of similarity, i.e., the NPTVA should be an electrical analog of the nonlinear host system. Analytical formulas for the NPTVA parameters are derived using the homotopy perturbation method. Doing so, a nonlinear generalization of Den Hartog’s equal-peak tuning rule is developed for piezoelectric vibration absorbers.

  12. Miniature Piezoelectric Macro-Mass Balance

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart; Trebi-Ollennu, Ashitey; Bonitz, Robert G.; Bar-Cohen, Yoseph

    2010-01-01

    Mass balances usually use a strain gauge that requires an impedance measurement and is susceptible to noise and thermal drift. A piezoelectric balance can be used to measure mass directly by monitoring the voltage developed across the piezoelectric balance, which is linear with weight or it can be used in resonance to produce a frequency change proportional to the mass change (see figure). The piezoelectric actuator/balance is swept in frequency through its fundamental resonance. If a small mass is added to the balance, the resonance frequency shifts down in proportion to the mass. By monitoring the frequency shift, the mass can be determined. This design allows for two independent measurements of mass. Additionally, more than one sample can be verified because this invention allows for each sample to be transported away from the measuring device upon completion of the measurement, if required. A piezoelectric actuator, or many piezoelectric actuators, was placed between the collection plate of the sampling system and the support structure. As the sample mass is added to the plate, the piezoelectrics are stressed, causing them to produce a voltage that is proportional to the mass and acceleration. In addition, a change in mass delta m produces a change in the resonance frequency with delta f proportional to delta m. In a microgravity environment, the spacecraft could be accelerated to produce a force on the piezoelectric actuator that would produce a voltage proportional to the mass and acceleration. Alternatively, the acceleration could be used to force the mass on the plate, and the inertial effects of the mass on the plate would produce a shift in the resonance frequency with the change in frequency related to the mass change. Three prototypes of the mass balance mechanism were developed. These macro-mass balances each consist of a solid base and an APA 60 Cedrat flextensional piezoelectric actuator supporting a measuring plate. A similar structure with 3 APA

  13. A piezoelectric pseudo-bimorph actuator

    NASA Astrophysics Data System (ADS)

    Shi, Huaduo; Chen, Jianguo; Liu, Guoxi; Xiao, Wenlei; Dong, Shuxiang

    2013-06-01

    We report a piezoelectric pseudo-bimorph actuator, which is made of only one single plate with interdigitated electrodes on both sides and polarized alternately in longitudinal direction. Like a bimorph actuator, it can also produce a large bending actuation based on anti-symmetrically longitudinal piezoelectric d33 strain effect under an applied electric field. The presented pseudo-bimorph actuator shows much better temperature stability than conventional piezoelectric bimorph actuators from room temperature to the depolarization temperature of the material due to lacking of interface strain loss.

  14. Finite element analysis of the dynamic behavior of radially polarized Functionally Graded Piezoelectric (FGP) structures

    NASA Astrophysics Data System (ADS)

    Kandasamy, Ramkumar; Cui, Fangsen

    2016-04-01

    In the traditional layered piezoelectric structures, high stress concentrations could cause the structural failure in interlayer surfaces due to repeated strain reversals. To overcome the performance limitations of these structures, the concept of Functionally Graded Materials (FGMs) has been introduced to improve the lifetime, integrity, and reliability of these structures. In this paper, the free and forced vibration of radially polarized Functionally Graded Piezoelectric (FGP) cylinders under different sets of loading are studied. Material properties such as piezoelectric, elastic and permittivity are assumed to change along its thickness, based on a specific gradation function. Four-parameter power law distribution is used to grade the volume fraction of the constituents comprising of PZT-5A and PZT-5H. Material property is assumed to be temperature dependent for a few numerical studies. The present modeling approach is validated by comparing the free and forced vibration of radially polarized Functionally Graded Piezoelectric (FGP) cylinders with those reported in the literature. The effects of material composition, loading and boundary conditions on the dynamic behavior of FGP cylinder are described. Since the modeling of functionally graded piezoelectric systems is challenging, the present study can help in the design and analysis of FGP cylinders.

  15. Active-passive hybrid piezoelectric actuators for high-precision hard disk drive servo systems

    NASA Astrophysics Data System (ADS)

    Chan, Kwong Wah; Liao, Wei-Hsin

    2006-03-01

    Positioning precision is crucial to today's increasingly high-speed, high-capacity, high data density, and miniaturized hard disk drives (HDDs). The demand for higher bandwidth servo systems that can quickly and precisely position the read/write head on a high track density becomes more pressing. Recently, the idea of applying dual-stage actuators to track servo systems has been studied. The push-pull piezoelectric actuated devices have been developed as micro actuators for fine and fast positioning, while the voice coil motor functions as a large but coarse seeking. However, the current dual-stage actuator design uses piezoelectric patches only without passive damping. In this paper, we propose a dual-stage servo system using enhanced active-passive hybrid piezoelectric actuators. The proposed actuators will improve the existing dual-stage actuators for higher precision and shock resistance, due to the incorporation of passive damping in the design. We aim to develop this hybrid servo system not only to increase speed of track seeking but also to improve precision of track following servos in HDDs. New piezoelectrically actuated suspensions with passive damping have been designed and fabricated. In order to evaluate positioning and track following performances for the dual-stage track servo systems, experimental efforts are carried out to implement the synthesized active-passive suspension structure with enhanced piezoelectric actuators using a composite nonlinear feedback controller.

  16. Piezoelectric ZnO-CNT nanotubes under axial strain and electrical voltage

    NASA Astrophysics Data System (ADS)

    Zhang, Jin; Wang, Ruijie; Wang, Chengyuan

    2012-09-01

    This paper aims to study the mechanical responses of a piezoelectric composite nanotube subject to an axial strain and electrical voltage. The nanotubes are fabricated by coating carbon nanotubes (CNTs) with zinc oxide (ZnO) nanocrystal. The axial buckling of the ZnO-CNTs nanotubes (ZCNTs) is investigated by using a composite Euler beam model accounting for the piezoelectricity of the coating layer. Particular attention is paid to the strengthening effect of the core CNT and the effect of the piezoelectricity of the outer ZnO layer. Pre-buckling analysis is also conducted to study the static deformation prior to the buckling. Analytical solutions are obtained based on the theory of three-dimensional elasticity and piezoelectricity. In particular, a tensile radial stress is achieved at the ZnO-CNT interface, which tends to separate the ZnO layer from core CNT and may generate delamination in composite ZCNTs. The size-dependence and physical basis of such an interface stress is thus discussed in details for ZCNTs.

  17. The Effects of Single-Wall Carbon Nanotubes on the Shear Piezoelectricity of Biopolymers

    NASA Technical Reports Server (NTRS)

    Lovell, Conrad; Fitz-Gerald, James M.; Harrison, Joycelyn S.; Park, Cheol

    2008-01-01

    Shear piezoelectricity was investigated in a series of composites consisting of increased loadings of single-wall carbon nanotubes (SWCNTs) in poly (gamma-benzyl-L-glutamate), or PBLG. The effects of the SWCNTs on this material property in PBLG will be discussed. Their influence on the morphology of the polymer (degree of orientation and crystallinity), and electrical and dielectric properties of the composite will be reported

  18. Piezoelectric and Semiconducting Coupled Nanogenerators

    NASA Technical Reports Server (NTRS)

    Wang, Zhong L. (Inventor); Song, Jinhui (Inventor); Wang, Xudong (Inventor)

    2012-01-01

    An electrical generator includes a substrate, a semiconductor piezoelectric structure having a first end and an opposite second end disposed adjacent to the substrate, a first conductive contact and a second conductive contact. The structure bends when a force is applied adjacent to the first end, thereby causing an electrical potential difference to exist between a first side and a second side of the structure. The first conductive contact is in electrical communication with the first end and includes a material that creates a Schottky barrier between a portion of the first end of the structure and the first conductive contact. The first conductive contact is also disposed relative to the structure in a position so that the Schottky barrier is forward biased when the structure is deformed, thereby allowing current to flow from the first conductive contact into the first end.

  19. Discrete-Layer Piezoelectric Plate and Shell Models for Active Tip-Clearance Control

    NASA Technical Reports Server (NTRS)

    Heyliger, P. R.; Ramirez, G.; Pei, K. C.

    1994-01-01

    The objectives of this work were to develop computational tools for the analysis of active-sensory composite structures with added or embedded piezoelectric layers. The targeted application for this class of smart composite laminates and the analytical development is the accomplishment of active tip-clearance control in turbomachinery components. Two distinct theories and analytical models were developed and explored under this contract: (1) a discrete-layer plate theory and corresponding computational models, and (2) a three dimensional general discrete-layer element generated in curvilinear coordinates for modeling laminated composite piezoelectric shells. Both models were developed from the complete electromechanical constitutive relations of piezoelectric materials, and incorporate both displacements and potentials as state variables. This report describes the development and results of these models. The discrete-layer theories imply that the displacement field and electrostatic potential through-the-thickness of the laminate are described over an individual layer rather than as a smeared function over the thickness of the entire plate or shell thickness. This is especially crucial for composites with embedded piezoelectric layers, as the actuating and sensing elements within these layers are poorly represented by effective or smeared properties. Linear Lagrange interpolation polynomials were used to describe the through-thickness laminate behavior. Both analytic and finite element approximations were used in the plane or surface of the structure. In this context, theoretical developments are presented for the discrete-layer plate theory, the discrete-layer shell theory, and the formulation of an exact solution for simply-supported piezoelectric plates. Finally, evaluations and results from a number of separate examples are presented for the static and dynamic analysis of the plate geometry. Comparisons between the different approaches are provided when

  20. Computational homogenization of fibrous piezoelectric materials

    NASA Astrophysics Data System (ADS)

    Maruccio, Claudio; De Lorenzis, Laura; Persano, Luana; Pisignano, Dario

    2015-05-01

    Flexible piezoelectric devices made of polymeric materials are widely used for micro- and nano-electro-mechanical systems. In particular, numerous recent applications concern energy harvesting. Due to the importance of computational modeling to understand the influence that microscale geometry and constitutive variables exert on the macroscopic behavior, a numerical approach is developed here for multiscale and multiphysics modeling of thin piezoelectric sheets made of aligned arrays of polymeric nanofibers, manufactured by electrospinning. At the microscale, the representative volume element consists in piezoelectric polymeric nanofibers, assumed to feature a piezoelastic behavior and subjected to electromechanical contact constraints. The latter are incorporated into the virtual work equations by formulating suitable electric, mechanical and coupling potentials and the constraints are enforced by using the penalty method. From the solution of the micro-scale boundary value problem, a suitable scale transition procedure leads to identifying the performance of a macroscopic thin piezoelectric shell element.

  1. Polarization Stability of Amorphous Piezoelectric Polyimides

    NASA Technical Reports Server (NTRS)

    Park, C.; Ounaies, Z.; Su, J.; Smith, J. G., Jr.; Harrison, J. S.

    2000-01-01

    Amorphous polyimides containing polar functional groups have been synthesized and investigated for potential use as high temperature piezoelectric sensors. The thermal stability of the piezoelectric effect of one polyimide was evaluated as a function of various curing and poling conditions under dynamic and static thermal stimuli. First, the polymer samples were thermally cycled under strain by systematically increasing the maximum temperature from 50 C to 200 C while the piezoelectric strain coefficient was being measured. Second, the samples were isothermally aged at an elevated temperature in air, and the isothermal decay of the remanent polarization was measured at room temperature as a function of time. Both conventional and corona poling methods were evaluated. This material exhibited good thermal stability of the piezoelectric properties up to 100 C.

  2. Thermally Stable Piezoelectric and Pyroelectric Polymers

    NASA Technical Reports Server (NTRS)

    Simpson, Joycelyn O.; St. Clair, Terry L.

    2006-01-01

    A class of thermally stable piezoelectric and pyroelectric polymers, and an improved method of making them, have been invented. These polymers can be used as substrates for a wide variety of electromechanical transducers, sensors, and actuators.

  3. Piezoelectric devices for generating low power

    NASA Astrophysics Data System (ADS)

    Chilibon, Irinela

    2016-12-01

    This paper reviews concepts and applications in low-power electronics and energy harvesting technologies. Various piezoelectric materials and devices for small power generators useful in renewable electricity are presented. The vibrating piezoelectric device differs from the typical electrical power source in that it has capacitive rather than inductive source impedance, and may be driven by mechanical vibrations of varying amplitude. In general, vibration energy could be converted into electrical energy using one of three techniques: electrostatic charge, magnetic fields and piezoelectric. A low power piezoelectric generator, having a PZT element was realised in order to supply small electronic elements, such as optoelectronic small devices, LEDs, electronic watches, small sensors, interferometry with lasers or Micro-electro-mechanical System (MEMS) array with multi-cantilevers.

  4. Simulation of Piezoelectric Jellyfish Power Generator

    NASA Astrophysics Data System (ADS)

    Wu, Yeong-Jen; Lai, Wei-Hsiang

    The energy problem is getting increasingly serious. As such, unused energy recovery technology is crucial for environmental protection, which has been investigated extensively. Several methods have been developed to utilize scavenged energy from the environment, such as waste heat, solar energy, wind energy, and tides energy to convert into useful power. There is a new idea of piezoelectric jellyfish generator which combines the utilization of sea wave and vibration energy. When sea wave passes through the jellyfish, the wave causes the tentacles to vibrate. The tentacles is made of piezoelectric polymer which can convert the strain energy into electrical energy. This paper discusses about the piezoelectric jellyfish's tentacles being disturbed by wave in the sea. We employed the commercial CFD software CFD-ACE+ 2006 to simulate this phenomenon. The parameters including its tentacle length (L) and wave propagating function (Y) are studied which affect the piezoelectric jellyfish capacity to generate power.

  5. Studying insect motion with piezoelectric sensors

    NASA Astrophysics Data System (ADS)

    Mika, Bartosz; Lee, Hyungoo; González, Jorge M.; Vinson, S. Bradleigh; Liang, Hong

    2007-04-01

    Piezoelectric materials have been widely used in applications such as transducers, acoustic components, as well as motion, pressure and airborne sensors. Because of the material's biocompatibility and flexibility, we have been able to apply small piezoelectric sensors, made of PVDF, to cockroaches. We built a laboratory test system to study the piezoelectric properties of a bending sensor. The tested motion was compared with that of the sensor attached to a cockroach. Surface characterization and finite element analysis revealed the effects of microstructure on piezoelectric response. The sensor attachment enables us to monitor the insects' locomotion and study their behaviors. The applications of engineering materials to insects opens the door to innovating approaches to integrating biological, mechanical and electrical systems.

  6. A nanoscale piezoelectric transformer for low-voltage transistors.

    PubMed

    Agarwal, Sapan; Yablonovitch, Eli

    2014-11-12

    A novel piezoelectric voltage transformer for low-voltage transistors is proposed. Placing a piezoelectric transformer on the gate of a field-effect transistor results in the piezoelectric transformer field-effect transistor that can switch at significantly lower voltages than a conventional transistor. The piezoelectric transformer operates by using one piezoelectric to squeeze another piezoelectric to generate a higher output voltage than the input voltage. Multiple piezoelectrics can be used to squeeze a single piezoelectric layer to generate an even higher voltage amplification. Coupled electrical and mechanical modeling in COMSOL predicts a 12.5× voltage amplification for a six-layer piezoelectric transformer. This would lead to more than a 150× reduction in the power needed for communications.

  7. Improved Multiple-DOF SAW Piezoelectric Motors

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Bao, Xiaoqi; Hull, Anthony; Wright, John

    2003-01-01

    Surface-acoustic-wave (SAW) piezoelectric motors of a proposed type would be capable of operating in multiple degrees of freedom (DOFs) simultaneously and would be amenable to integration into diverse structures and mechanisms. These motors would be compact and structurally simple and would not contain bearings or lead screws. One example of a particularly useful motor of this type would be a two-dimensional- translation stage. Another such example would be a self-actuated spherical joint that could be made to undergo controlled, simultaneous rotations about two orthogonal axes: Such a motor could serve as a mechanism for aiming an "eyeball" camera or as a compact transducer in, and an integral part of, a joint in a robot arm. The multiple-DOF SAW piezoelectric motors as now proposed would be successors to the ones reported in "Multiple-DOF Surface-Acoustic-Wave Piezoelectric Motors" (NPO-20735), NASA Tech Briefs, Vol. 24, No. 12 (December 2000), page 5b. The basic principle of operation of a multiple-DOF SAW piezoelectric motor is a straightforward extension of that of single-DOF SAW piezoelectric motors, which have been reported in several previous NASA Tech Briefs articles: For example, in the case of a linear SAW piezoelectric motor, piezoelectric transducers at opposite ends of a stator excite surface acoustic waves that travel along the surface of the stator. An object (denoted the slider) is pressed against the stator with sufficient pressure (in practice .300 MPa) that it remains in frictional contact with the stator at all times. The slider rides the crests of the waves and is thereby made to move along the surface of the stator. The direction of motion (forward or backward) is controlled by selecting the relative phase of waves generated by the two piezoelectric transducers. The speed increases with the amplitude of the waves and thus with the magnitude of the voltage applied to the transducers.

  8. Distributed structural control using multilayered piezoelectric actuators

    NASA Technical Reports Server (NTRS)

    Cudney, Harley H.; Inman, Daniel J.; Oshman, Yaakov

    1990-01-01

    A method of segmenting piezoelectric sensors and actuators is proposed which can preclude the currently experienced cancelation of sensor signals, or the reduction of actuator effectiveness, due to the integration of the property undergoing measurement or control. The segmentation method is demonstrated by a model developed for beam structures, to which multiple layers of piezoelectric materials are attached. A numerical study is undertaken of increasing active and passive damping of a beam using the segmented sensors and actuators over unsegmented sensors and actuators.

  9. Half-Heusler semiconductors as piezoelectrics.

    PubMed

    Roy, Anindya; Bennett, Joseph W; Rabe, Karin M; Vanderbilt, David

    2012-07-20

    We use a first-principles rational-design approach to demonstrate the potential of semiconducting half-Heusler compounds as a previously unrecognized class of piezoelectric materials. We perform a high-throughput scan of a large number of compounds, testing for insulating character and calculating structural, dielectric, and piezoelectric properties. Our results provide guidance for the experimental realization and characterization of high-performance materials in this class that may be suitable for practical applications.

  10. Piezoelectric Polymer Tactile Sensor Arrays for Robotics.

    DTIC Science & Technology

    1987-12-01

    machine and positioning the HRP master to be copied in the master position. The emulsion surface of the HRP master faced outward. The master vacuum ...machine. The HRP was centered before the copy vacuum button was pressed to secure the HRP. The emulsion surfaces of the HRP’s came into contact when the...Compared to Experiment for the Piezoelectric Constant e’. .................... 2.32 2.5 Calculated Fractional Contributions for the Piezoelectric Constant

  11. In situ health monitoring of piezoelectric sensors

    NASA Technical Reports Server (NTRS)

    Jensen, Scott L. (Inventor); Drouant, George J. (Inventor)

    2013-01-01

    An in situ health monitoring apparatus may include an exciter circuit that applies a pulse to a piezoelectric transducer and a data processing system that determines the piezoelectric transducer's dynamic response to the first pulse. The dynamic response can be used to evaluate the operating range, health, and as-mounted resonance frequency of the transducer, as well as the strength of a coupling between the transducer and a structure and the health of the structure.

  12. Dual-frequency super harmonic imaging piezoelectric transducers for transrectal ultrasound

    NASA Astrophysics Data System (ADS)

    Kim, Jinwook; Li, Sibo; Kasoji, Sandeep; Dayton, Paul A.; Jiang, Xiaoning

    2015-03-01

    In this paper, a 2/14 MHz dual-frequency single-element transducer and a 2/22 MHz sub-array (16/48-elements linear array) transducer were developed for contrast enhanced super-harmonic ultrasound imaging of prostate cancer with the low frequency ultrasound transducer as a transmitter for contrast agent (microbubble) excitation and the high frequency transducer as a receiver for detection of nonlinear responses from microbubbles. The 1-3 piezoelectric composite was used as active materials of the single-element transducers due to its low acoustic impedance and high coupling factor. A high dielectric constant PZT ceramic was used for the sub-array transducer due to its high dielectric property induced relatively low electrical impedance. The possible resonance modes of the active elements were estimated using finite element analysis (FEA). The pulse-echo response, peak-negative pressure and bubble response were tested, followed by in vitro contrast imaging tests using a graphite-gelatin tissue-mimicking phantom. The single-element dual frequency transducer (8 × 4 × 2 mm3) showed a -6 dB fractional bandwidth of 56.5% for the transmitter, and 41.8% for the receiver. A 2 MHz-transmitter (730 μm pitch and 6.5 mm elevation aperture) and a 22 MHz-receiver (240 μm pitch and 1.5 mm aperture) of the sub-array transducer exhibited -6 dB fractional bandwidth of 51.0% and 40.2%, respectively. The peak negative pressure at the far field was about -1.3 MPa with 200 Vpp, 1-cycle 2 MHz burst, which is high enough to excite microbubbles for nonlinear responses. The 7th harmonic responses from micro bubbles were successfully detected in the phantom imaging test showing a contrast-to-tissue ratio (CTR) of 16 dB.

  13. Dielectric loss against piezoelectric power harvesting

    NASA Astrophysics Data System (ADS)

    Liang, Junrui; Shu-Hung Chung, Henry; Liao, Wei-Hsin

    2014-09-01

    Piezoelectricity is one of the most popular electromechanical transduction mechanisms for constructing kinetic energy harvesting systems. When a standard energy harvesting (SEH) interface circuit, i.e., bridge rectifier plus filter capacitor, is utilized for collecting piezoelectric power, the previous literature showed that the power conversion can be well predicted without much consideration for the effect of dielectric loss. Yet, as the conversion power gets higher by adopting power-boosting interface circuits, such as synchronized switch harvesting on inductor (SSHI), the neglect of dielectric loss might give rise to deviation in harvested power estimation. Given the continuous progress on power-boosting interface circuits, the role of dielectric loss in practical piezoelectric energy harvesting (PEH) systems should receive attention with better evaluation. Based on the integrated equivalent impedance network model, this fast track communication provides a comprehensive study on the susceptibility of harvested power in PEH systems under different conditions. It shows that, dielectric loss always counteracts piezoelectric power harvesting by causing charge leakage across piezoelectric capacitance. In particular, taking corresponding ideal lossless cases as references, the counteractive effect might be aggravated under one of the five conditions: larger dielectric loss tangent, lower vibration frequency, further away from resonance, weaker electromechanical coupling, or using power-boosting interface circuit. These relationships are valuable for the study of PEH systems, as they not only help explain the role of dielectric loss in piezoelectric power harvesting, but also add complementary insights for material, structure, excitation, and circuit considerations towards holistic evaluation and design for practical PEH systems.

  14. Effects of composition and temperature on the large field behavior of [011]{sub C} relaxor ferroelectric single crystals

    SciTech Connect

    Gallagher, John A.; Lynch, Christopher S.; Tian, Jian

    2014-08-04

    The large field behavior of [011]{sub C} cut relaxor ferroelectric lead indium niobate–lead magnesium niobate–lead titanate, xPb(In{sub 1/2}Nb{sub 1/2})O{sub 3}-(1-x-y)Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-yPbTiO{sub 3}, single crystals was experimentally characterized in the piezoelectric d{sub 322}-mode configuration under combined mechanical, electrical, and thermal loading. Increasing the concentration of lead indium niobate and decreasing the concentration of lead titanate in compositions near the morphotropic phase boundary resulted in a decrease of mechanical compliance, dielectric permittivity, and piezoelectric coefficients as well as a shift from a continuous to a discontinuous transformation.

  15. Development of Piezoelectric Zinc Oxide Nanoparticle-Poly(Vinylidene Fluoride) Nanocomposites for Sensing and Actuation

    NASA Astrophysics Data System (ADS)

    Dodds, John Steven

    piezoelectricity. Next, a series of sensing validation tests was performed. The voltage generated by poled ZnO-based thin films was compared to commercially poled PVDF copolymer thin films. The hammer impact tests employed showed comparable results between the PVDF-TrFE/ZnO films and commercial samples. It was concluded that increasing ZnO content enhanced bulk film piezoelectricity. The films have been further validated for sensing using different energy levels of hammer impact, different distances between the impact locations and the film electrodes, cantilever free vibration testing for dynamic strain sensing, and load frame testing for sensitivity and linearity measurements. Actuators were also constructed by integrating fingered electrodes with PVDF-TrFE/ZnO films. Actuation tests using the pitch-catch methodology were performed on a test pipe structure. The presence of guided waves was first confirmed by measuring pipe vibrations using commercial Macro Fiber Composite (MFC) sensors. Additionally, damage detection was validated using a pitch-catch setup. Overall, a piezoelectric nanocomposite transducer was successfully fabricated and demonstrated for use as both a sensor and an actuator for SHM.

  16. Significantly improved piezoelectric thermal stability of cellular polypropylene films by high pressure fluorination and post-treatments

    SciTech Connect

    An Zhenlian; Mao Mingjun; Cang Jun; Zhang Yewen; Zheng Feihu

    2012-01-15

    Cellular polypropylene (PP) films were fluorinated under a high pressure of 13 bar of the F{sub 2}/N{sub 2} mixture and were post-treated by nitrous oxide and isothermal crystallization. The fluorinated and post-treated PP films after being expanded and corona charged exhibit a significantly improved piezoelectric thermal stability. After annealing at 70 deg. C for 151 h or at 90 deg. C for 224 h, the piezoelectric d{sub 33} value of the fluorinated and post-treated piezoelectric sample still retains 58% or 45% of its initial d{sub 33} value, while the corresponding value of the virgin piezoelectric sample has decreased to 29% or 15% of the initial value. Chemical composition analysis of the cross section of the fluorinated and post-treated film by energy-dispersive x-ray spectroscopy indicates that the internal layers have been fluorinated, in spite of a lower degree of fluorination compared with the fluorinated surface layer. Short-circuit and open-circuit TSD current measurements reveal that the fluorinated internal layers, like the fluorinated surface layer, also have very deep charge traps, although there probably is a difference in density of the deep traps between them. The deeply trapped charge on the internal layers of the fluorinated and post-treated piezoelectric sample is responsible for its significantly improved piezoelectric thermal stability.

  17. Integrated actuation and energy harvesting in prestressed piezoelectric synthetic jets

    NASA Astrophysics Data System (ADS)

    Mane, Poorna

    With the looming energy crisis compounded by the global economic downturn there is an urgent need to increase energy efficiency and to discover new energy sources. An approach to solve this problem is to improve the efficiency of aerodynamic vehicles by using active flow control tools such as synthetic jet actuators. These devices are able to reduce fuel consumption and streamlined vehicle design by reducing drag and weight, and increasing maneuverability. Hence, the main goal of this dissertation is to study factors that affect the efficiency of synthetic jets by incorporating energy harvesting into actuator design using prestressed piezoelectric composites. Four state-of-the-art piezoelectric composites were chosen as active diaphragms in synthetic jet actuators. These composites not only overcome the inherent brittle and fragile nature of piezoelectric materials but also enhance domain movement which in turn enhances intrinsic contributions. With these varying characteristics among different types of composites, the intricacies of the synthetic jet design and its implementation increases. In addition the electrical power requirements of piezoelectric materials make the new SJA system a coupled multiphysics problem involving electro-mechanical and structural-fluid interactions. Due to the nature of this system, a design of experiments approach, a method of combining experiments and statistics, is utilized. Geometric and electro-mechanical factors are investigated using a fractional factorial design with peak synthetic jet velocity as a response variable. Furthermore, energy generated by the system oscillations is harvested with a prestressed composite and a piezo-polymer. Using response surface methodology the process is optimized under different temperatures and pressures to simulate harsh environmental conditions. Results of the fractional factorial experimental design showed that cavity dimensions and type of signal used to drive the synthetic jet actuator

  18. Calendering effects on the physical and electrochemical properties of Li[Ni1/3Mn1/3Co1/3]O2 cathode

    NASA Astrophysics Data System (ADS)

    Zheng, Honghe; Tan, Li; Liu, Gao; Song, Xiangyun; Battaglia, Vincent S.

    2012-06-01

    Li[Ni1/3Mn1/3Co1/3]O2 cathode laminate containing 8% PVDF and 7% acetylene black is fabricated and calendered to different porosities. Calendering effects on the physical and electrochemical properties of the Li[Ni1/3Mn1/3Co1/3]O2 cathode are investigated. It is found that mechanical properties of the composite laminate strongly depend on the electrode porosity whereas the electronic conductivity is not significantly affected by calendering. Electrochemical performances including the specific capacity, the first coulombic efficiency, cycling performance and rate capability for the cathode at different porosities are compared. An optimized porosity of around 30-40% is identified. Electrochemical impedance spectroscopy (EIS) studies illustrate that calendering improves the electronic conductivity between active particles at relatively high porosities, but increases charge transfer resistance at electrode/electrolyte interface at relatively low porosities. An increase of activation energy of Li interfacial transfer for the electrode at 0% porosity indicates a relatively high barrier of activation at the electrode/electrolyte interface, which accounts for the poor rate capability of the electrode at extremely low porosity.

  19. Piezoelectric microcantilever serum protein detector

    NASA Astrophysics Data System (ADS)

    Capobianco, Joseph A.

    The development of a serum protein detector will provide opportunities for better screening of at-risk cancer patients, tighter surveillance of disease recurrence and better monitoring of treatment. An integrated system that can process clinical samples for a number of different types of biomarkers would be a useful tool in the early detection of cancer. Also, screening biomarkers such as antibodies in serum would provide clinicians with information regarding the patient's response to treatment. Therefore, the goal of this study is to develop a sensor which can be used for rapid, all-electrical, real-time, label-fee, in-situ, specific quantification of cancer markers, e.g., human epidermal receptor 2 (Her2) or antibodies, in serum. To achieve this end, piezoelectric microcantilever sensors (PEMS) were constructed using an 8 mum thick lead magnesium niobate-lead titanate (PMN-PT) freestanding film as the piezoelectric layer. The desired limit of detection is on the order of pg/mL. In order to achieve this goal the higher frequency lateral extension modes were used. Also, as the driving and sensing of the PEMS is electrical, the PEMS must be insulated in a manner that allows it to function in aqueous solutions. The insulation layer must also be compatible with standardized bioconjugation techniques. Finally, detection of both cancer antigens and antibodies in serum was carried out, and the results were compared to a standard commercialized protocol. PEMS have demonstrated the capability of detecting Her2 at a concentration of 5 pg/mL in diluted human serum (1:40) in less than 1 hour. The approach can be easily translated into the clinical setting because the sensitivity is more than sufficient for monitoring prognosis of breast cancer patients. In addition to Her2 detection, antibodies in serum were assayed in order to demonstrate the feasibility of monitoring the immune response for antibody-dependent cellular cytotoxicity (ADCC) in patients on antibody therapies

  20. Model of a Piezoelectric Transducer

    NASA Technical Reports Server (NTRS)

    Goodenow, Debra

    2004-01-01

    It's difficult to control liquid and gas in propellant tanks in zero gravity. A possible a design would utilize acoustic liquid manipulation (ALM) technology which uses ultrasonic beams conducted through a liquid and solid media, to push gas bubbles in the liquid to desirable locations. We can propel and control the bubble with acoustic radiation pressure by aiming the acoustic waves on the bubble s surface. This allows us to design a so called smart tank in which the ALM devices transfer the gas to the outer wall of the tank and isolating the liquid in the center. Because the heat transfer rate of a gas is lower of that of the liquid it would substantially decrease boil off and provide of for a longer storage life. The ALM beam is composed of little wavelets which are individual waves that constructively interfere with each other to produce a single, combined acoustic wave front. This is accomplished by using a set of synchronized ultrasound transducers arranged in an array. A slight phase offset of these elements allows us to focus and steer the beam. The device that we are using to produce the acoustic beam is called the piezoelectric transducer. This device converts electrical energy to mechanical energy, which appears in the form of acoustic energy. Therefore the behavior of the device is dependent on both the mechanical characteristics, such as its density, cross-sectional area, and its electrical characteristics, such as, electric flux permittivity and coupling factor. These devices can also be set up in a number of modes which are determined by the way the piezoelectric device is arranged, and the shape of the transducer. For this application we are using the longitudinal or thickness mode for our operation. The transducer also vibrates in the lateral mode, and one of the goals of my project is to decrease the amount of energy lost to the lateral mode. To model the behavior of the transducers I will be using Pspice, electric circuit modeling tool, to

  1. High-efficiency piezoelectric micro harvester for collecting low-frequency mechanical energy

    NASA Astrophysics Data System (ADS)

    Li, Xin; Song, Jinhui; Feng, Shuanglong; Xie, Xiong; Li, Zhenhu; Wang, Liang; Pu, Yayun; Kah Soh, Ai; Shen, Jun; Lu, Wenqiang; Liu, Shuangyi

    2016-12-01

    A single-layer zinc oxide (ZnO) nanorod array-based micro energy harvester was designed and integrated with a piezoelectric metacapacitor. The device presents outstanding low-frequency (1-10 Hz) mechanical energy harvesting capabilities. When compared with conventional pristine ZnO nanostructured piezoelectric harvesters or generators, both open-circuit potential and short-circuit current are significantly enhanced (up to 3.1 V and 124 nA cm-2) for a single mechanical knock (˜34 kPa). Higher electromechanical conversion efficiency (1.3 pC/Pa) is also observed. The results indicate that the integration of the piezoelectric metacapacitor is a crucial factor for improving the low-frequency energy harvesting performance. A double piezoelectric-driven mechanism is proposed to explain current higher output power, in which the metacapacitor plays the multiple roles of charge pumping, storing and transferring. An as-fabricated prototype device for lighting an LED demonstrates high power transference capability, with over 95% transference efficiency to the external load.

  2. Analysis of nonlinear transient responses of piezoelectric resonators.

    PubMed

    Hagiwara, Manabu; Takahashi, Seita; Hoshina, Takuya; Takeda, Hiroaki; Tsurumi, Takaaki

    2011-09-01

    The electric transient response method is an effective technique to evaluate material constants of piezoelectric ceramics under high-power driving. In this study, we tried to incorporate nonlinear piezoelectric behaviors in the analysis of transient responses. As a base for handling the nonlinear piezoelectric responses, we proposed an assumption that the electric displacement is proportional to the strain without phase lag, which could be described by a real and constant piezoelectric e-coefficient. Piezoelectric constitutive equations including nonlinear responses were proposed to calculate transient responses of a piezoelectric resonator. The envelopes and waveforms of current and vibration velocity in transient responses observed in some piezoelectric ceramics could be fitted with the calculation including nonlinear responses. The procedure for calculation of mechanical quality factor Q(m) for piezoelectric resonators with nonlinear behaviors was also proposed.

  3. Narcotics detection using piezoelectric ringing

    NASA Astrophysics Data System (ADS)

    Rayner, Timothy J.; Magnuson, Erik E.; West, Rebecca; Lyndquist, R.

    1997-02-01

    Piezo-electric ringing (PER) has been demonstrated to be an effective means of scanning cargo for the presence of hidden narcotics. The PER signal is characteristic of certain types of crystallized material, such as cocaine hydrochloride. However, the PER signal cannot be used to conclusively identify all types of narcotic material, as the signal is not unique. For the purposes of cargo scanning, the PER technique is therefore most effective when used in combination with quadrupole resonance analysis (QRA). PER shares the same methodology as QRA technology, and can therefore be very easily and inexpensively integrated into existing QRA detectors. PER can be used as a pre-scanning technique before the QRA scan is applied and, because the PER scan is of a very short duration, can effectively offset some of the throughput limitations of standard QRA narcotics detectors. Following is a discussion of a PER detector developed by Quantum Manetics under contract to United States Customs. Design philosophy and performance are discussed, supported by results from recent tests conducted by the U.S. Drug Enforcement Agency and U.S. Customs.

  4. Multilayer Piezoelectric Stack Actuator Characterization

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart; Jones, Christopher M.; Aldrich, Jack B.; Blodget, Chad; Bao, Xioaqi; Badescu, Mircea; Bar-Cohen, Yoseph

    2008-01-01

    Future NASA missions are increasingly seeking to use actuators for precision positioning to accuracies of the order of fractions of a nanometer. For this purpose, multilayer piezoelectric stacks are being considered as actuators for driving these precision mechanisms. In this study, sets of commercial PZT stacks were tested in various AC and DC conditions at both nominal and extreme temperatures and voltages. AC signal testing included impedance, capacitance and dielectric loss factor of each actuator as a function of the small-signal driving sinusoidal frequency, and the ambient temperature. DC signal testing includes leakage current and displacement as a function of the applied DC voltage. The applied DC voltage was increased to over eight times the manufacturers' specifications to investigate the correlation between leakage current and breakdown voltage. Resonance characterization as a function of temperature was done over a temperature range of -180C to +200C which generally exceeded the manufacturers' specifications. In order to study the lifetime performance of these stacks, five actuators from one manufacturer were driven by a 60volt, 2 kHz sine-wave for ten billion cycles. The tests were performed using a Lab-View controlled automated data acquisition system that monitored the waveform of the stack electrical current and voltage. The measurements included the displacement, impedance, capacitance and leakage current and the analysis of the experimental results will be presented.

  5. Piezoelectric tunable microwave superconducting cavity

    NASA Astrophysics Data System (ADS)

    Carvalho, N. C.; Fan, Y.; Tobar, M. E.

    2016-09-01

    In the context of engineered quantum systems, there is a demand for superconducting tunable devices, able to operate with high-quality factors at power levels equivalent to only a few photons. In this work, we developed a 3D microwave re-entrant cavity with such characteristics ready to provide a very fine-tuning of a high-Q resonant mode over a large dynamic range. This system has an electronic tuning mechanism based on a mechanically amplified piezoelectric actuator, which controls the resonator dominant mode frequency by changing the cavity narrow gap by very small displacements. Experiments were conducted at room and dilution refrigerator temperatures showing a large dynamic range up to 4 GHz and 1 GHz, respectively, and were compared to a finite element method model simulated data. At elevated microwave power input, nonlinear thermal effects were observed to destroy the superconductivity of the cavity due to the large electric fields generated in the small gap of the re-entrant cavity.

  6. Multilayer piezoelectric stack actuator characterization

    NASA Astrophysics Data System (ADS)

    Sherrit, Stewart; Jones, Christopher M.; Aldrich, Jack B.; Blodget, Chad; Bao, Xioaqi; Badescu, Mircea; Bar-Cohen, Yoseph

    2008-03-01

    Future NASA missions are increasingly seeking to use actuators for precision positioning to accuracies of the order of fractions of a nanometer. For this purpose, multilayer piezoelectric stacks are being considered as actuators for driving these precision mechanisms. In this study, sets of commercial PZT stacks were tested in various AC and DC conditions at both nominal and extreme temperatures and voltages. AC signal testing included impedance, capacitance and dielectric loss factor of each actuator as a function of the small-signal driving sinusoidal frequency, and the ambient temperature. DC signal testing includes leakage current and displacement as a function of the applied DC voltage. The applied DC voltage was increased to over eight times the manufacturers' specifications to investigate the correlation between leakage current and breakdown voltage. Resonance characterization as a function of temperature was done over a temperature range of -180°C to +200°C which generally exceeded the manufacturers' specifications. In order to study the lifetime performance of these stacks, five actuators from one manufacturer were driven by a 60volt, 2 kHz sine-wave for ten billion cycles. The tests were performed using a Lab-View controlled automated data acquisition system that monitored the waveform of the stack electrical current and voltage. The measurements included the displacement, impedance, capacitance and leakage current and the analysis of the experimental results will be presented.

  7. Effects of an elastic mass on frequency response characteristics of an ultra-thin piezoelectric micro-acoustic actuator.

    PubMed

    Kim, Hye Jin; Yang, Woo Seok; No, Kwangsoo

    2013-08-01

    This paper presents an optimized method to improve the sound quality of ultra-thin piezoelectric micro-acoustic actuators. To achieve flat and smooth frequency response characteristics of the piezoelectric acoustic actuators, we have proposed an elastic mass attached to the acoustic diaphragm. The effects of the elastic mass on frequency response characteristics of the piezoelectric acoustic actuator were investigated by finite element analysis simulation and laser scanning vibrometer measurement. Based on the modal and vibrational characteristics, it was found that the fabricated piezoelectric acoustic actuator has a significant dip of 1.32 kHz and peak of 2.24 kHz, which correspond respectively to the (1,3) and (3,1) resonant modes of the acoustic diaphragm. However, by attaching an elastic mass to the acoustic diaphragm with a shape similar to the (3,1) mode, the resonant frequencies corresponding to the (1,3) and (3,1) modes shifted to higher frequencies and the vibrational displacements at each mode were dramatically reduced by about 40%. As a result, the dip at (1,3) mode was greatly improved by 13 dB and total harmonic distortion was dramatically reduced from 80.83% to 8.71%. This paper shows that the optimized elastic mass can allow flat and smooth frequency response characteristics by improving the significant peak and dip.

  8. A tunable piezoelectric Fresnel mirror for high-speed lineshaping

    NASA Astrophysics Data System (ADS)

    Brunne, Jens; Wapler, Matthias C.; Grunwald, Ruediger; Wallrabe, Ulrike

    2013-11-01

    We present the first tunable v-shaped mirror, also known as Fresnel mirror, that may be used to generate a quasi-nondiffracting line pattern, for example for applications in laser lithography or nanomachining with femtosecond lasers. The aperture of the device is 5 mm with a surface flatness of better than λ/10, and the range of the tilting angle is 1.3-38 mrad, resulting in a fringe spacing of 123 μm down to 4.2 μm for red light at 633 nm. In contrast to usual cantilever-comb setups, the mirrors are supported on a PDMS layer and tilted by a single piezoelectric actuator, providing a high resonance frequency of 5.1 kHz. The device is fabricated using laser rapid prototyping of silicon and a casting processes of soft polymers. We show the static and dynamic characterization of the mirror and the verification of the optical functionality.

  9. 50 CFR 1.3 - Service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Service. 1.3 Section 1.3 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR GENERAL PROVISIONS DEFINITIONS § 1.3 Service. Service means the United States Fish and Wildlife Service, Department of the Interior....

  10. 45 CFR 1216.1-3 - Policy.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false Policy. 1216.1-3 Section 1216.1-3 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE NONDISPLACEMENT OF EMPLOYED WORKERS AND NONIMPAIRMENT OF CONTRACTS FOR SERVICE § 1216.1-3 Policy. (a) Volunteers enrolled or participating in...

  11. 45 CFR 1211.1-3 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false Definitions. 1211.1-3 Section 1211.1-3 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE VOLUNTEER GRIEVANCE PROCEDURES § 1211.1-3 Definitions. (a) Volunteer means a person enrolled and currently serving as a full-time volunteer...

  12. 45 CFR 1210.1-3 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false Definitions. 1210.1-3 Section 1210.1-3 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE VISTA TRAINEE DESELECTION AND VOLUNTEER EARLY TERMINATION PROCEDURES General § 1210.1-3 Definitions. (a) Trainee means a person enrolled in...

  13. 5 CFR 1.3 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Definitions. 1.3 Section 1.3 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE RULES COVERAGE AND DEFINITIONS (RULE I) § 1.3 Definitions. As used in the rules in this subchapter: (a) Competitive service shall have the...

  14. 43 CFR 8365.1-3 - Vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Vehicles. 8365.1-3 Section 8365.1-3 Public... OF THE INTERIOR RECREATION PROGRAMS VISITOR SERVICES Rules of Conduct § 8365.1-3 Vehicles. (a) When operating a vehicle on the public lands, no person shall exceed posted speed limits, willfully...

  15. 43 CFR 8365.1-3 - Vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Vehicles. 8365.1-3 Section 8365.1-3 Public... OF THE INTERIOR RECREATION PROGRAMS VISITOR SERVICES Rules of Conduct § 8365.1-3 Vehicles. (a) When operating a vehicle on the public lands, no person shall exceed posted speed limits, willfully...

  16. 43 CFR 8365.1-3 - Vehicles.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Vehicles. 8365.1-3 Section 8365.1-3 Public... OF THE INTERIOR RECREATION PROGRAMS VISITOR SERVICES Rules of Conduct § 8365.1-3 Vehicles. (a) When operating a vehicle on the public lands, no person shall exceed posted speed limits, willfully...

  17. 43 CFR 8365.1-3 - Vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Vehicles. 8365.1-3 Section 8365.1-3 Public... OF THE INTERIOR RECREATION PROGRAMS VISITOR SERVICES Rules of Conduct § 8365.1-3 Vehicles. (a) When operating a vehicle on the public lands, no person shall exceed posted speed limits, willfully...

  18. Energy Harvesting From Low Frequency Applications Using Piezoelectric Materials

    SciTech Connect

    Li, Huidong; Tian, Chuan; Deng, Zhiqun

    2014-11-06

    This paper reviewed the state of research on piezoelectric energy harvesters. Various types of harvester configurations, piezoelectric materials, and techniques used to improve the mechanical-to-electrical energy conversion efficiency were discussed. Most of the piezoelectric energy harvesters studied today have focused on scavenging mechanical energy from vibration sources due to their abundance in both natural and industrial environments. Cantilever beams have been the most studied structure for piezoelectric energy harvester to date because of the high responsiveness to small vibrations.

  19. Piezoelectric biosensor with a ladder polymer substrate coating

    DOEpatents

    Renschler, Clifford L.; White, Christine A.; Carter, Robert M.

    1998-01-01

    A piezoelectric biosensor substrate useful for immobilizing biomolecules in an oriented manner on the surface of a piezoelectric sensor has a ladder polymer of polyacrylonitrile. To make the substrate, a solution of an organic polymer, preferably polyacrylonitrile, is applied to the surface of a piezoelectric sensor. The organic polymer is modifying by heating the polymer in a controlled fashion in air such that a ladder polymer is produced which, in turn, forms the attachment point for the biomolecules comprising the piezoelectric biosensor.

  20. Contact mechanics of piezoelectric ultrasonic motors

    NASA Astrophysics Data System (ADS)

    Wallaschek, Jörg

    1998-06-01

    Piezoelectric ultrasonic motors are driven by tangential stresses in the interface between stator and rotor. These stresses are generated by the elliptical motion of the material points of the stator or rotor surface and depend on frictional processes in the contact area. The contact mechanics of piezoelectric ultrasonic motors determines the operational characteristics, like rotational speed and torque or transmitted mechanical power and efficiency. Wear properties and lifetime of piezoelectric ultrasonic motors are also determined by contact mechanics. The goal of the present paper is to summarize the state of the art in the understanding of some fundamental processes governing the contact mechanics of piezoelectric ultrasonic motors. After a short introduction, a survey of publications devoted to the subject will be given. Then, an attempt will be made to classify the mechanical models, which were developed in order to explain the contact mechanics of piezoelectric ultrasonic motors, according to the physical effects which have been taken into account in their derivation. Some results concerning the choice of proper contact materials, wear and lifetime of ultrasonic motors will be addressed in a separate section. Finally a summary and outlook will be given and open questions for future research will be formulated.

  1. High-Fidelity Piezoelectric Audio Device

    NASA Technical Reports Server (NTRS)

    Woodward, Stanley E.; Fox, Robert L.; Bryant, Robert G.

    2003-01-01

    ModalMax is a very innovative means of harnessing the vibration of a piezoelectric actuator to produce an energy efficient low-profile device with high-bandwidth high-fidelity audio response. The piezoelectric audio device outperforms many commercially available speakers made using speaker cones. The piezoelectric device weighs substantially less (4 g) than the speaker cones which use magnets (10 g). ModalMax devices have extreme fabrication simplicity. The entire audio device is fabricated by lamination. The simplicity of the design lends itself to lower cost. The piezoelectric audio device can be used without its acoustic chambers and thereby resulting in a very low thickness of 0.023 in. (0.58 mm). The piezoelectric audio device can be completely encapsulated, which makes it very attractive for use in wet environments. Encapsulation does not significantly alter the audio response. Its small size (see Figure 1) is applicable to many consumer electronic products, such as pagers, portable radios, headphones, laptop computers, computer monitors, toys, and electronic games. The audio device can also be used in automobile or aircraft sound systems.

  2. Optical piezoelectric transducer for nano-ultrasonics.

    PubMed

    Lin, Kung-Hsuan; Chern, Gia-Wei; Yu, Cheng-Ta; Liu, Tzu-Ming; Pan, Chang-Chi; Chen, Guan-Ting; Chyi, Jen-Inn; Huang, Sheng-Wen; Li, Pai-Chi; Sun, Chi-Kuang

    2005-08-01

    Piezoelectric semiconductor strained layers can be treated as piezoelectric transducers to generate nanometer-wavelength and THz-frequency acoustic waves. The mechanism of nano-acoustic wave (NAW) generation in strained piezoelectric layers, induced by femtosecond optical pulses, can be modeled by a macroscopic elastic continuum theory. The optical absorption change of the strained layers modulated by NAW through quantum-confined Franz-Keldysh (QCFK) effects allows optical detection of the propagating NAW. Based on these piezoelectric-based optical principles, we have designed an optical piezoelectric transducer (OPT) to generate NAW. The optically generated NAW is then applied to one-dimensional (1-D) ultrasonic scan for thickness measurement, which is the first step toward multidimensional nano-ultrasonic imaging. By launching a NAW pulse and resolving the returned acoustic echo signal with femtosecond optical pulses, the thickness of the studied layer can be measured with <1 nm resolution. This nano-structured OPT technique will provide the key toward the realization of nano-ultrasonics, which is analogous to the typical ultrasonic techniques but in a nanometer scale.

  3. Enhanced dielectric and piezoelectric responses in Zn1-xMgxO thin films near the phase separation boundary

    NASA Astrophysics Data System (ADS)

    Kang, Xiaoyu; Shetty, Smitha; Garten, Lauren; Ihlefeld, Jon F.; Trolier-McKinstry, Susan; Maria, Jon-Paul

    2017-01-01

    Dielectric and piezoelectric properties for Zn1-xMgxO (ZMO) thin films are reported as a function of MgO composition up to and including the phase separation region. Zn1-xMgxO (0.25 ≤ x ≤ 0.5) thin films with c-axis textures were deposited by pulsed laser deposition on platinized sapphire substrates. The films were phase pure wurtzite for MgO concentrations up to 40%; above that limit, a second phase with rocksalt structure evolves with strong {100} texture. With increasing MgO concentration, the out-of-plane (d33,f) and in-plane (e31,f) piezoelectric coefficients increase by 360% and 290%, respectively. The increase in piezoelectric coefficients is accompanied by a 35% increase in relative permittivity. Loss tangent values fall monotonically with increasing MgO concentration, reaching a minimum of 0.001 for x ≥ 0.30, at which point the band gap is reported to be 4 eV. The enhanced piezoelectric response, the large band gap, and the low dielectric loss make Zn1-xMgxO an interesting candidate for thin film piezoelectric devices, and demonstrate that compositional phase transformations provide opportunities for property engineering.

  4. Enhanced dielectric and piezoelectric responses in Zn1-xMgxO thin films near the phase separation boundary

    DOE PAGES

    Kang, Xiaoyu; Shetty, Smitha; Garten, Lauren; ...

    2017-01-23

    Dielectric and piezoelectric properties for Zn1-xMgxO (ZMO) thin films are reported as a function of MgO composition up to and including the phase separation region. Zn1-xMgxO (0.25 ≤ x ≤ 0.5) thin films with c-axis textures were deposited by pulsed laser deposition on platinized sapphire substrates. The films were phase pure wurtzite for MgO concentrations up to 40%; above that limit, a second phase with rocksalt structure evolves with strong {100} texture. With increasing MgO concentration, the out-of-plane (d33,f) and in-plane (e31,f) piezoelectric coefficients increase by 360% and 290%, respectively. The increase in piezoelectric coefficients is accompanied by a 35%more » increase in relative permittivity. Loss tangent values fall monotonically with increasing MgO concentration, reaching a minimum of 0.001 for x ≥ 0.30, at which point the band gap is reported to be 4 eV. As a result, the enhanced piezoelectric response, the large band gap, and the low dielectric loss make Zn1-xMgxO an interesting candidate for thin film piezoelectric devices, and demonstrate that compositional phase transformations provide opportunities for property engineering.« less

  5. Defect Engineering of Lead-Free Piezoelectrics with High Piezoelectric Properties and Temperature-Stability.

    PubMed

    Feng, Yu; Li, Wei-Li; Xu, Dan; Qiao, Yu-Long; Yu, Yang; Zhao, Yu; Fei, Wei-Dong

    2016-04-13

    The high piezoelectricity of ABO3-type lead-free piezoelectric materials can be achieved with the help of either morphotropic phase boundary (MPB) or polymorphic phase transition (PPT). Here, we propose a new defect engineering route to the excellent piezoelectric properties, in which doped smaller acceptor and donor ions substituting bivalent A-sites are utilized to bring local lattice distortion and lower symmetry. A concrete paradigm is presented, (Li-Al) codoped BaTiO3 perovskite, that exhibits a largely thermo-stable piezoelectric constant (>300 pC/N) and huge mechanical quality factor (>2000). A systematic analysis including theoretical analysis and simulation results indicates that the Li(+) and Al(3+) ions are inclined to occupy the neighboring A-sites in the lattice and constitute a defect dipole (ionic pairs). The defect dipoles possess a kind of dipole moment which tends to align directionally after thermo-electric treatment. A mechanism related to the defect symmetry principle, phase transition, and defect migration is proposed to explain the outstanding piezoelectric properties. The present study opens a new development window for excellent piezoelectricity and provides a promising route to the potential utilization of lead-free piezoelectrics in high power applications.

  6. Characterization of a Piezoelectric Buzzer Using a Michelson Interferometer

    ERIC Educational Resources Information Center

    Lloyd, S.; Paetkau, M.

    2010-01-01

    A piezoelectric material generates an electric potential across its surface when subjected to mechanical stress; conversely, the inverse piezoelectric effect describes the expansion or contraction of the material when subjected to some applied voltage. Piezoelectric materials are used in devices such as doorbell buzzers, barbeque igniters, and…

  7. Piezoelectric Properties of Non-Polar Block Copolymers

    SciTech Connect

    Pester, Christian; Ruppel, Markus A; Schoberth, Heiko; Schmidt, K.; Liedel, Clemens; Van Rijn, Patrick; Littrell, Ken; Schindler, Kerstin; Hiltl, Stephanie; Czubak, Thomas; Mays, Jimmy; Urban, Volker S; Boker, Alexander

    2011-01-01

    Piezoelectric properties in non-polar block copolymers are a novelty in the field of electroactive polymers. The piezoelectric susceptibility of poly(styrene-b-isoprene) block copolymer lamellae is found to be up to an order of magnitude higher when compared to classic piezoelectric materials. The electroactive response increases with temperature and is found to be strongest in the disordered phase.

  8. Low-power piezoelectric micro-machined valve

    NASA Technical Reports Server (NTRS)

    Gianchandani, Yogesh B. (Inventor); Nellis, Gregory Francis (Inventor); Klein, Sanford A. (Inventor); Park, John Moon (Inventor); Evans, Allan Thomas (Inventor); Taylor, Ryan (Inventor); Brosten, Tyler R. (Inventor)

    2010-01-01

    A piezoelectric microvalve employs a valve element formed of hermetically sealed and opposed plates flexed together by a cross axis piezoelectric element. Large flow modulation with small piezoelectric actuator displacement is obtained by perimeter augmentation of the valve seat which dramatically increases the change in valve flow area for small deflections.

  9. Silver nanowire dopant enhancing piezoelectricity of electrospun PVDF nanofiber web

    NASA Astrophysics Data System (ADS)

    Li, Baozhang; Zheng, Jianming; Xu, Chunye

    2013-08-01

    A highly sensitive flexible piezoelectric material is developed by using a composite nanofibers web of polymer and metal. The nanofibers webs are made by electrospinning a mixed solution of poly(vinylidene fluoride) (PVDF) and silver nanowires (AgNWs) in the co-solvent of dimethyl formamide and acetone. SEM images show that the obtained webs are composed of AgNWs doped PVDF fibers with diameters ranging from 200nm to 500nm. Our FTIR and XRD results indicate that doping AgNWs into PVDF fiber can enhance the contents of beta phase of the PVDF. UV-Vis spectrum shows a slightly red shift at 324 nm and 341 nm after the AgNWs doping into PVDF, proving the presence of interaction between AgNWs and the PVDF polymer chain. The piezoelectric constant d33 of the nanofibers webs tested with a homemade system, reveals a good agreement with FTIR and XRD characteristic, and the highest one is up to 29.8 pC/N for the nanofibers webs containing 1.5% AgNWs, which is close to that of poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE), 77/23). This study may provide a way to develop high-performance flexible sensors.

  10. Active Piezoelectric Structures for Tip Clearance Management Assessed

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Managing blade tip clearance in turbomachinery stages is critical to developing advanced subsonic propulsion systems. Active casing structures with embedded piezoelectric actuators appear to be a promising solution. They can control static and dynamic tip clearance, compensate for uneven deflections, and accomplish electromechanical coupling at the material level. In addition, they have a compact design. To assess the feasibility of this concept and assist the development of these novel structures, the NASA Lewis Research Center developed in-house computational capabilities for composite structures with piezoelectric actuators and sensors, and subsequently used them to simulate candidate active casing structures. The simulations indicated the potential of active casings to modify the blade tip clearance enough to improve stage efficiency. They also provided valuable design information, such as preliminary actuator configurations (number and location) and the corresponding voltage patterns required to compensate for uneven casing deformations. An active ovalization of a casing with four discrete piezoceramic actuators attached on the outer surface is shown. The center figure shows the predicted radial displacements along the hoop direction that are induced when electrostatic voltage is applied at the piezoceramic actuators. This work, which has demonstrated the capabilities of in-house computational models to analyze and design active casing structures, is expected to contribute toward the development of advanced subsonic engines.

  11. Overview of NASA Langley's Piezoelectric Ceramic Packaging Technology and Applications

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G.

    2007-01-01

    Over the past decade, NASA Langley Research Center (LaRC) has developed several actuator packaging concepts designed to enhance the performance of commercial electroactive ceramics. NASA LaRC focused on properly designed actuator and sensor packaging for the following reasons, increased durability, protect the working material from the environment, allow for proper mechanical and electrical contact, afford "ready to use" mechanisms that are scalable, and develop fabrication methodology applicable to any active material of the same physical class. It is more cost effective to enhance or tailor the performance of existing systems, through innovative packaging, than to develop, test and manufacture new materials. This approach led to the development of several solid state actuators that include THUNDER, the Macrofiber Composite or (MFC) and the Radial Field Diaphragm or (RFD). All these actuators are fabricated using standard materials and processes derived from earlier concepts. NASA s fabrication and packaging technology as yielded, piezoelectric actuators and sensors that are easy to implement, reliable, consistent in properties, and of lower cost to manufacture in quantity, than their predecessors (as evidenced by their continued commercial availability.) These piezoelectric actuators have helped foster new research and development in areas involving computational modeling, actuator specific refinements, and engineering system redesign which led to new applications for piezo-based devices that replace traditional systems currently in use.

  12. Pulsed DC magnetron sputtered piezoelectric thin film aluminum nitride – Technology and piezoelectric properties

    SciTech Connect

    Stoeckel, C. Kaufmann, C.; Hahn, R.; Schulze, R.; Billep, D.; Gessner, T.

    2014-07-21

    Pulsed DC magnetron sputtered aluminum nitride (AlN) thin films are prepared on several seed layers and at different sputtering conditions. The piezoelectric c-axis (002) orientation of the AlN is analyzed with X-ray diffraction method. The transverse piezoelectric coefficient d{sub 31} is determined with a Laser-Doppler-Vibrometer at cantilevers and membranes by analytical calculations and finite element method. Additionally, thin film AlN on bulk silicon is used to characterize the longitudinal piezoelectric charge coefficient d{sub 33}.

  13. Giant piezoelectricity of monolayer group IV monochalcogenides

    NASA Astrophysics Data System (ADS)

    Fei, Ruixiang; Li, Wenbin; Li, Ju; Yang, Li

    We predict enormous, anisotropic piezoelectric effects in intrinsic monolayer group IV monochalcogenides (MX, M =Sn or Ge, X =Se or S), including SnSe, SnS, GeSe, and GeS. Using first-principle simulations based on the modern theory of polarization, we find that their piezoelectric coefficients are about one to two orders of magnitude larger than those of other 2D materials, such as MoS2 and GaSe, and bulk quartz and AlN which are widely used in industry. This enhancement is a result of the unique ``puckered'' C2v symmetry and electronic structure of monolayer group IV monochalcogenides. Given the achieved experimental advances in the fabrication of monolayers, their flexible character, and ability to withstand enormous strain, these 2D structures with giant piezoelectric effects may be promising for a broad range of applications such as nano-sized sensors, piezotronics, and energy harvesting in portable electronic devices.

  14. Piezoelectric energy harvesting computer controlled test bench

    NASA Astrophysics Data System (ADS)

    Vázquez-Rodriguez, M.; Jiménez, F. J.; de Frutos, J.; Alonso, D.

    2016-09-01

    In this paper a new computer controlled (C.C.) laboratory test bench is presented. The patented test bench is made up of a C.C. road traffic simulator, C.C. electronic hardware involved in automating measurements, and test bench control software interface programmed in LabVIEW™. Our research is focused on characterizing electronic energy harvesting piezoelectric-based elements in road traffic environments to extract (or "harvest") maximum power. In mechanical to electrical energy conversion, mechanical impacts or vibrational behavior are commonly used, and several major problems need to be solved to perform optimal harvesting systems including, but no limited to, primary energy source modeling, energy conversion, and energy storage. It is described a novel C.C. test bench that obtains, in an accurate and automatized process, a generalized linear equivalent electrical model of piezoelectric elements and piezoelectric based energy store harvesting circuits in order to scale energy generation with multiple devices integrated in different topologies.

  15. Ciliae-based actuator with piezoelectric excitation

    NASA Astrophysics Data System (ADS)

    Pott, Peter P.; Carrasco, Alvaro; Schlaak, Helmut F.

    2012-06-01

    Small actuators based on the inverse piezoelectric effect are successfully deployed in commercial applications. Usually, ultrasonic motors are used. Based on resonance effects these motors provide a pronounced nonlinearity at low speeds and thus put high demands on the control algorithm. In contrast, piezoelectric stepping motors are mechanically complex and provide only low speeds. The contribution at hand describes a proposed design for a new piezoelectric motor based on cilia friction that can be manufactured at low costs. The cilia are made from uniaxial carbon-fibre reinforced plastics. The derived CFRP-brushes are pressed perpendicularly to the rotor surface to produce force or torque. First experiments prove the feasibility of the concept. A net pushing force of 500 mN is achieved.

  16. Piezoelectric energy harvesting computer controlled test bench.

    PubMed

    Vázquez-Rodriguez, M; Jiménez, F J; de Frutos, J; Alonso, D

    2016-09-01

    In this paper a new computer controlled (C.C.) laboratory test bench is presented. The patented test bench is made up of a C.C. road traffic simulator, C.C. electronic hardware involved in automating measurements, and test bench control software interface programmed in LabVIEW™. Our research is focused on characterizing electronic energy harvesting piezoelectric-based elements in road traffic environments to extract (or "harvest") maximum power. In mechanical to electrical energy conversion, mechanical impacts or vibrational behavior are commonly used, and several major problems need to be solved to perform optimal harvesting systems including, but no limited to, primary energy source modeling, energy conversion, and energy storage. It is described a novel C.C. test bench that obtains, in an accurate and automatized process, a generalized linear equivalent electrical model of piezoelectric elements and piezoelectric based energy store harvesting circuits in order to scale energy generation with multiple devices integrated in different topologies.

  17. Flow Energy Piezoelectric Bimorph Nozzle Harvester

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart (Inventor); Walkemeyer, Phillip E. (Inventor); Hall, Jeffrey L. (Inventor); Lee, Hyeong Jae (Inventor); Colonius, Tim (Inventor); Tosi, Phillipe (Inventor); Kim, Namhyo (Inventor); Sun, Kai (Inventor); Corbett, Thomas Gary (Inventor); Arrazola, Alvaro Jose (Inventor)

    2016-01-01

    A flow energy harvesting device having a harvester pipe includes a flow inlet that receives flow from a primary pipe, a flow outlet that returns the flow into the primary pipe, and a flow diverter within the harvester pipe having an inlet section coupled to the flow inlet, a flow constriction section coupled to the inlet section and positioned at a midpoint of the harvester pipe and having a spline shape with a substantially reduced flow opening size at a constriction point along the spline shape, and an outlet section coupled to the constriction section. The harvester pipe may further include a piezoelectric structure extending from the inlet section through the constriction section and point such that the fluid flow past the constriction point results in oscillatory pressure amplitude inducing vibrations in the piezoelectric structure sufficient to cause a direct piezoelectric effect and to generate electrical power for harvesting.

  18. Charge Capacity of Piezoelectric Membrane Wings

    NASA Astrophysics Data System (ADS)

    Grybas, Matthew; Hubner, J. Paul

    2015-11-01

    Micro air vehicles (MAVs) have small wings often fabricated with flexible frames and membranes. These membranes flex and vibrate. Piezoelectric films have the ability to convert induced stress or strain into electrical energy. Thus, it is of interest to investigate if piezoelectric films can be used as a structural member of an MAV wing and generate both lift and energy through passive vibrations. Both a shaker test and a wind tunnel test have been conducted to characterize and assess energy production and aerodynamic characteristics including lift, drag and efficiency. The piezoelectric film has been successful as a lifting surface and produces a measurable charge. This work was supported by NSF REU Site Award 1358991.

  19. Design considerations for piezoelectric polymer ultrasound transducers.

    PubMed

    Brown, L F

    2000-01-01

    Much work has been published on the design of ultrasound transducers using piezoelectric ceramics, but a great deal of this work does not apply when using the piezoelectric polymers because of their unique electrical and mechanical properties. The purpose of this paper is to review and present new insight into seven important considerations for the design of active piezoelectric polymer ultrasound transducers: piezoelectric polymer materials selection, transducer construction and packaging requirements, materials characterization and modeling, film thickness and active area design, electroding selection, backing material design, and front protection/matching layer design. Besides reviewing these design considerations, this paper also presents new insight into the design of active piezoelectric polymer ultrasonic transducers. The design and fabrication of an immersible ultrasonic transducer, which has no adhesive layer between the active element and backing layer, is included. The transducer features direct deposition of poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] copolymer onto an insulated aluminum backing substrate. Pulse-echo tests indicated a minimum insertion loss of 37 dB and -6 dB bandwidth of 9.8 to 22 MHz (71%). The use of polymer wear-protection/quarter-wave matching layers is also discussed. Test results on a P(VDF-TrFE) transducer showed that a Mylar/sup TM/ front layer provided a slight increase in pulse-echo amplitude of 15% (or 1.2 dB) and an increase in -6 dB pulse-echo fractional bandwidth from 86 to 95%. Theoretical derivations are reported for optimizing the active area of the piezoelectric polymer element for maximum power transfer at resonance. These derivations are extended to the special case for a low profile (i.e., thin) shielded transducer. A method for modeling the non-linear loading effects of a commercial pulser-receiver is also included.

  20. Radial-Electric-Field Piezoelectric Diaphragm Pumps

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G.; Working, Dennis C.; Mossi, Karla; Castro, Nicholas D.; Mane, Pooma

    2009-01-01

    In a recently invented class of piezoelectric diaphragm pumps, the electrode patterns on the piezoelectric diaphragms are configured so that the electric fields in the diaphragms have symmetrical radial (along-the-surface) components in addition to through-the-thickness components. Previously, it was accepted in the piezoelectric-transducer art that in order to produce the out-of-plane bending displacement of a diaphragm needed for pumping, one must make the electric field asymmetrical through the thickness, typically by means of electrodes placed on only one side of the piezoelectric material. In the present invention, electrodes are placed on both sides and patterned so as to produce substantial radial as well as through-the-thickness components. Moreover, unlike in the prior art, the electric field can be symmetrical through the thickness. Tests have shown in a given diaphragm that an electrode configuration according to this invention produces more displacement than does a conventional one-sided electrode pattern. The invention admits of numerous variations characterized by various degrees of complexity. Figure 1 is a simplified depiction of a basic version. As in other piezoelectric diaphragm pumps of similar basic design, the prime mover is a piezoelectric diaphragm. Application of a suitable voltage to the electrodes on the diaphragm causes it to undergo out-of-plane bending. The bending displacement pushes a fluid out of, or pulls the fluid into, a chamber bounded partly by the diaphragm. Also as in other diaphragm pumps in general, check valves ensure that the fluid flows only in through one port and only out through another port.

  1. Reducing the capacitance of piezoelectric film sensors.

    PubMed

    González, Martín G; Sorichetti, Patricio A; Santiago, Guillermo D

    2016-04-01

    We present a novel design for large area, wideband, polymer piezoelectric sensor with low capacitance. The large area allows better spatial resolution in applications such as photoacoustic tomography and the reduced capacitance eases the design of fast transimpedance amplifiers. The metalized piezoelectric polymer thin film is segmented into N sections, electrically connected in series. In this way, the total capacitance is reduced by a factor 1/N(2), whereas the mechanical response and the active area of the sensor are not modified. We show the construction details for a two-section sensor, together with the impedance spectroscopy and impulse response experimental results that validate the design.

  2. Surface-Acoustic-Wave Piezoelectric Microbalance

    NASA Technical Reports Server (NTRS)

    Chuan, Raymond L.; Bowers, William D.

    1992-01-01

    Improved piezoelectric microbalances developed for use in measuring masses of volcanic, aerosol, and other small particles suspended in air. Sensitive microbalance used to analyze airborne particles in real time in environments as diverse as clean rooms or upper atmosphere. Surface-acoustic-wave resonator includes input and output sets of interdigitated electrodes and two passive conductive patterns acting as reflectors. Mechanical energy travels both ways out from middle and reflected back toward middle. Microbalance and associated circuitry fit in small package. Circuit draws only 80 mA at 5 V. Sensitivity more than 400 times that of bulk piezoelectric microbalance.

  3. Optimal piezoelectric switching technique for vibration damping

    NASA Astrophysics Data System (ADS)

    Neubauer, Marcus; Oleskiewicz, Robert

    2007-04-01

    This paper describes piezoelectric switching techniques for vibration damping. The dynamical behaviour of a piezoceramics connected to a switching LR shunt and the dissipated energy are obtained using a fundamental piezoelectric model. All calculations are performed in a normalized way and highlight the influence of the electromechanical coupling coefficient of the piezoceramics and the shunt parameters. For the first time, a precise result for the dynamics of a shunted piezoceramics is derived. The analytic results are used to determine the optimal switching sequence and external branch parameters in order to maximize the damping performance. The results are validated by measurements of a clamped beam.

  4. Thermal model for piezoelectric transducers (L).

    PubMed

    Butler, John L; Butler, Alexander L; Butler, Stephen C

    2012-10-01

    A lumped parameter equivalent circuit basis for calculating and allocating heat power sources in a transducer is presented along with experimental results. The simple model allows heat power calculations at resonance based on readily attainable parameters for transducers with uniform fields. Measured and finite element analysis of steady state thermal results are compared for the monopole mode of the single crystal driven modal transducer projector. The model serves as a physical and computational aid in the evaluation of piezoelectric transducer heating and may be used for evaluating highly coupled single crystal as well as ceramic piezoelectric transducers.

  5. Optimum placement of piezoelectric ceramic modules for vibration suppression of highly constrained structures

    NASA Astrophysics Data System (ADS)

    Belloli, Alberto; Ermanni, Paolo

    2007-10-01

    The vibration suppression efficiency of so-called shunted piezoelectric systems is decisively influenced by the number, shape, dimensions and position of the piezoelectric ceramic elements integrated into the structure. This paper presents a procedure based on evolutionary algorithms for optimum placement of piezoelectric ceramic modules on highly constrained lightweight structures. The optimization loop includes the CAD software CATIA V5, the FE package ANSYS and DynOPS, a proprietary software tool able to connect the Evolving Object library with any simulation software that can be started in batch mode. A user-defined piezoelectric shell element is integrated into ANSYS 9.0. The generalized electromechanical coupling coefficient is used as the optimization objective. Position, dimensions, orientation, embedding location in the composite lay-up and wiring of customized patches are determined for optimum vibration suppression under consideration of operational and manufacturing constraints, such as added mass, maximum strain and requirements on the control circuit. A rear wing of a racing car is investigated as the test object for complex, highly constrained geometries.

  6. Active sensing and damage detection using piezoelectric zinc oxide-based nanocomposites.

    PubMed

    Meyers, Frederick N; Loh, Kenneth J; Dodds, John S; Baltazar, Arturo

    2013-05-10

    This study investigated the design and performance of piezoelectric nanocomposite-based interdigitated transducers (IDTs) for active sensing and damage detection. First, thin films that are highly piezoelectric and mechanically flexible were designed by embedding zinc oxide (ZnO) nanoparticles in a poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) piezo-polymer matrix. Second, the suspended nanoparticle solutions were then spin coated onto patterned comb electrodes to fabricate the IDTs. The films were then poled to align their electric domains and to increase their permanent piezoelectricity. Upon IDT fabrication, its sensing and actuation of Lamb waves on an aluminum pipe was validated. These results were also compared to data obtained from commercial Macro Fiber Composite IDT transducers. In the last phase of this work, damage detection was demonstrated by mounting these nanocomposite sensors and actuators (using a pitch-catch setup) onto an aluminum pipe and plate. Damage was simulated by tightening a band clamp around the pipe and by drilling holes in the plate. A damage index calculation was used to compare results corresponding to different levels of damage applied to the plate (i.e., different drilled hole depths), and good correlation was observed. Thus, ZnO/PVDF-TrFE transducers were shown to have the potential for use as piezoelectric transducers for structural health monitoring and damage detection.

  7. Active sensing and damage detection using piezoelectric zinc oxide-based nanocomposites

    NASA Astrophysics Data System (ADS)

    Meyers, Frederick N.; Loh, Kenneth J.; Dodds, John S.; Baltazar, Arturo

    2013-05-01

    This study investigated the design and performance of piezoelectric nanocomposite-based interdigitated transducers (IDTs) for active sensing and damage detection. First, thin films that are highly piezoelectric and mechanically flexible were designed by embedding zinc oxide (ZnO) nanoparticles in a poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) piezo-polymer matrix. Second, the suspended nanoparticle solutions were then spin coated onto patterned comb electrodes to fabricate the IDTs. The films were then poled to align their electric domains and to increase their permanent piezoelectricity. Upon IDT fabrication, its sensing and actuation of Lamb waves on an aluminum pipe was validated. These results were also compared to data obtained from commercial Macro Fiber Composite IDT transducers. In the last phase of this work, damage detection was demonstrated by mounting these nanocomposite sensors and actuators (using a pitch-catch setup) onto an aluminum pipe and plate. Damage was simulated by tightening a band clamp around the pipe and by drilling holes in the plate. A damage index calculation was used to compare results corresponding to different levels of damage applied to the plate (i.e., different drilled hole depths), and good correlation was observed. Thus, ZnO/PVDF-TrFE transducers were shown to have the potential for use as piezoelectric transducers for structural health monitoring and damage detection.

  8. Micromachined PIN-PMN-PT crystal composite transducer for high-frequency intravascular ultrasound (IVUS) imaging.

    PubMed

    Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K Kirk

    2014-07-01

    In this paper, we report the use of micromachined PbIn1/2Nb1/2O3-PbMg1/3Nb2/3O3-PbTiO 3 (PIN-PMNPT) single crystal 1-3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at the center frequency of 41 MHz, which resulted in a 43 μm axial resolution. Ex vivo IVUS imaging was conducted to demonstrate the improvement of axial resolution. The composite transducer was capable of identifying the three layers of a cadaver coronary artery specimen with high resolution. The PIN-PMN-PT-based composite has superior piezoelectric properties comparable to PMN-PT-based composite and its thermal stability is higher than PMN-PT. PIN-PMN-PT crystal can be an alternative approach for fabricating high-frequency composite, instead of using PMN-PT.

  9. Efficacy of the technique of piezoelectric corticotomy for orthodontic traction of impacted mandibular third molars.

    PubMed

    Ma, Zhigui; Xu, Guangzhou; Yang, Chi; Xie, Qianyang; Shen, Yuqing; Zhang, Shanyong

    2015-04-01

    Our aim was to assess the efficacy of piezoelectric corticotomy for orthodontic traction of mandibular third molars close to the inferior alveolar nerve. Thirty patients with impacted third molars close to the nerve were included in the study, 15 of whom were treated with conventional orthodontic traction and 15 with piezoelectric corticotomy. We recorded duration of treatment including exposure and orthodontic traction, and time to the final extraction. Postoperative complications including trismus, swelling, and pain were also noted. Alveolar bone levels mesial and distal to the second molars were evaluated on cone-beam computed tomographic (CT) images. Student's t test was used to assess the significance of differences between the groups. After orthodontic treatments all impacted third molars were successfully removed from the inferior alveolar nerve without neurological damage. The mean (SD) duration of surgical exposure in the piezoelectric corticotomy group was significantly longer than that in the conventional group (p=0.01). The mean (SD) duration of traction was 4 (2.3) months after piezoelectric corticotomy, much shorter than the 7.5 (1.3) months in the conventional group (p=0.03). There were no significant differences in postoperative complications between the groups. There was a significant increase in the distal alveolar height of second molars after treatment in both groups (p<0.01). We conclude that the use of piezoelectric corticotomy allows more efficient and faster traction of third molars with a close relation between the root and the inferior alveolar nerve, although it took longer than the traditional technique.

  10. The development of piezoelectric crystal gyroscopes in China

    NASA Astrophysics Data System (ADS)

    Chen, Feng-Yu; Qing, Rong-Kang

    The operation principles and basic characteristics of a newly-developed vibrating-beam piezoelectric crystal angular rate gyroscope are discussed along with the gyroscope applications. Several applications of piezoelectric gyroscopes are described, including its use as a telemetering sensor, attidude measuring device in automobiles, in geological exploraton drilling, and as a sensing element in ship and aircraft control systems. Specifications are presented for several gyroscopes, including those for two piezoelectric angular rate gyros with different applications (telemetering and control), a typical piezoelectric angular displacement gyro, and a piezoelectric inclinometer.

  11. Nanogenerator comprising piezoelectric semiconducting nanostructures and Schottky conductive contacts

    NASA Technical Reports Server (NTRS)

    Wang, Zhong L. (Inventor); Wang, Xudong (Inventor); Song, Jinhui (Inventor); Zhou, Jun (Inventor); He, Jr-Hau (Inventor)

    2011-01-01

    A semiconducting device includes a substrate, a piezoelectric wire, a structure, a first electrode and a second electrode. The piezoelectric wire has a first end and an opposite second end and is disposed on the substrate. The structure causes the piezoelectric wire to bend in a predetermined manner between the first end and the second end so that the piezoelectric wire enters a first semiconducting state. The first electrode is coupled to the first end and the second electrode is coupled to the second end so that when the piezoelectric wire is in the first semiconducting state, an electrical characteristic will be exhibited between the first electrode and the second electrode.

  12. Nanotubes, nanorods and nanowires having piezoelectric and/or pyroelectric properties and devices manufactured therefrom

    DOEpatents

    Russell, Thomas P [Amherst, MA; Lutkenhaus, Jodie [Wethersfield, CT

    2012-05-15

    Disclosed herein is a device comprising a pair of electrodes; and a nanotube, a nanorod and/or a nanowire; the nanotube, nanorod and/or nanowire comprising a piezoelectric and/or pyroelectric polymeric composition; the pair of electrodes being in electrical communication with opposing surfaces of the nanotube, nanorod and/or a nanowire; the pair of electrodes being perpendicular to a longitudinal axis of the nanotube, nanorod and/or a nanowire.

  13. Anodic aluminum oxide-epoxy composite acoustic matching layers for ultrasonic transducer application.

    PubMed

    Fang, H J; Chen, Y; Wong, C M; Qiu, W B; Chan, H L W; Dai, J Y; Li, Q; Yan, Q F

    2016-08-01

    The goal of this work is to demonstrate the application of anodic aluminum oxide (AAO) template as matching layer of ultrasonic transducer. Quarter-wavelength acoustic matching layer is known as a vital component in medical ultrasonic transducers to compensate the acoustic impedance mismatch between piezoelectric element and human body. The AAO matching layer is made of anodic aluminum oxide template filled with epoxy resin, i.e. AAO-epoxy 1-3 composite. Using this composite as the first matching layer, a ∼12MHz ultrasonic transducer based on soft lead zirconate titanate piezoelectric ceramic is fabricated, and pulse-echo measurements show that the transducer exhibits very good performance with broad bandwidth of 68% (-6dB) and two-way insertion loss of -22.7dB. Wire phantom ultrasonic image is also used to evaluate the transducer's performance, and the results confirm the process feasibility and merit of AAO-epoxy composite as a new matching material for ultrasonic transducer application. This matching scheme provides a solution to address the problems existing in the conventional 0-3 composite matching layer and suggests another useful application of AAO template.

  14. Numerical simulation of piezoelectric effect of bone under ultrasound irradiation

    NASA Astrophysics Data System (ADS)

    Hosokawa, Atsushi

    2015-07-01

    The piezoelectric effect of bone under ultrasound irradiation was numerically simulated using an elastic finite-difference time-domain method with piezoelectric constitutive equations (PE-FDTD method). First, to demonstrate the validity of the PE-FDTD method, the ultrasound propagation in piezoelectric ceramics was simulated and then compared with the experimental results. The simulated and experimental waveforms propagating through the ceramics were in good agreement. Next, the piezoelectric effect of human cortical bone on the ultrasound propagation was investigated by PE-FDTD simulation. The simulated result showed that the difference between the waveforms propagating through the bone without and with piezoelectricity was negligible. Finally, the spatial distributions of the electric fields in a human femur induced by ultrasound irradiation were simulated. The electric fields were changed by a bone fracture, which depended on piezoelectric anisotropy. In conclusion, the PE-FDTD method is considered to be useful for investigating the piezoelectric effect of bone.

  15. Correlation of Bulk Dielectric and Piezoelectric Properties to the Local Scale Phase Transformations, Domain Morphology, and Crystal Structure Modified

    SciTech Connect

    Priya, Shashank; Viehland, Dwight

    2014-12-14

    Three year program entitled “Correlation of bulk dielectric and piezoelectric properties to the local scale phase transformations, domain morphology, and crystal structure in modified lead-free grain-textured ceramics and single crystals” was supported by the Department of Energy. This was a joint research program between D. Viehland and S. Priya at Virginia Tech. Single crystal and textured ceramics have been synthesized and characterized. Our goals have been (i) to conduct investigations of lead-free piezoelectric systems to establish the local structural and domain morphologies that result in enhanced properties, and (ii) to synthesize polycrystalline and grain oriented ceramics for understanding the role of composition, microstructure, and anisotropy

  16. Piezoelectric electrospun nanocomposite comprising Au NPs/PVDF for nerve tissue engineering.

    PubMed

    Motamedi, Asma Sadat; Mirzadeh, Hamid; Hajiesmaeilbaigi, Fereshteh; Bagheri Khoulenjani, Shadab; Shokrgozar, Mohammad Ali

    2017-03-03

    In this study, gold nanoparticles/Polyvinylidenefluoride composite electrospun mat with enhanced piezoelectricity were fabricated and characterized. Gold colloidal nanoparticles (Au NPs) were prepared via laser ablation of metallic targets in liquid media. The active Q-switched Nd:YAG laser was used as an irradiation source. Then, PVDF (Polyvinylidenefluoride) was dissolved in Au NPs colloidal solution at 30% wt for the synthesis of Au NPs/PVDF composite nanofibers by electrospinning. The optical absorbance spectra of Au NPS and the polymeric solutions were obtained by the UV-Visible spectroscopy. Moreover, the morphology of Au NPS, nanostructures of fibers and diameter size distribution of nanofibers were analyzed by Scanning Electron Microscopy (SEM), Field Emission Scanning Electron Microscopy (FESEM) and Transmitted Electron Microscopy (TEM) methods. The crystallinity and piezoelectricity of PVDF and Au NPs/PVDF composite nanofibers mats were measured by X-Ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) methods. Subsequently, in vitro cytocompatibility was evaluated by MTT assay and the attachment and morphology of PC-12 cells cultured on scaffolds were studied. It was found that laser ablated Au NPs can be used in electrospun nanofibers of PVDF with adequate structural properties and increase piezoelectricity of nanofibers which might be suitable for applying as nerve tissue engineering scaffolds. This article is protected by copyright. All rights reserved.

  17. Highly piezoelectric MgZr co-doped aluminum nitride-based vibrational energy harvesters.

    PubMed

    Minh, Le Van; Hara, Motoaki; Yokoyama, Tsuyoshi; Nishihara, Tokihiro; Ueda, Masanori; Kuwano, Hiroki

    2015-11-01

    The first MgZr co-doped AlN-based vibrational energy harvester (VEH) is presented. (MgZr)AlN, which is a new class of doped AlN, provides high piezoelectricity and cost advantage. Using 13%-(MgZr)-doped AlN for micromachined VEHs, maximum output power of 1.3 μW was achieved with a Q-factor of 400 when resonant frequency, vibration acceleration, load resistance were 792 Hz, 8 m/s(2), and 1.1 MΩ, respectively. Normalized power density was 8.1 kW·g(-2)·m(-3). This was one of the highest values among the currently available piezoelectric VEHs.

  18. Ultrasound radiating performances of piezoelectric micromachined ultrasonic transmitter

    NASA Astrophysics Data System (ADS)

    Wang, Zhihong; Zhu, Weiguang; Tan, Ooi Kiang; Chao, Chen; Zhu, Hong; Miao, Jianmin

    2005-01-01

    This letter reports on a membrane-type piezoelectric micromachined ultrasonic transducer (pMUT). It consists of 3.5 or 7μm thick composite lead zirconate titanate (PZT) film on a multilayered membrane and works as an ultrasonic transmitter. The ultrasound-radiating performance of the transmitter, in response to a continuous ac driving voltage, has been tested systematically. The generated sound pressure level at resonance frequency of the transmitter varies with the applied dc bias and driving voltage and can exceed 110dB at a measuring distance of 12mm. For a given square membrane with the same multilayer structure and thickness, the resonance frequency of the transmitter is inversely proportional to the area of the membrane, and can be further tuned by control of the poling conditions of the PZT film or the applied dc bias.

  19. Piezoelectric and electrostrictive materials for transducers applications, volume 1

    NASA Astrophysics Data System (ADS)

    Cross, L. E.; Newnham, R. E.; Bhalla, A. S.; Dougherty, J. P.; Adair, J. H.; Varadan, V. K.; Varadan, V. V.

    1992-01-01

    Highlights of the past year's activities include: An increased emphasis upon the flextensional (moonie) type actuators, modeling both the internal stress distribution as a function of geometry, and the very interesting resonant mode structure of the composites; a more refined focus upon the performance of piezoelectric ceramic transducers, particularly under high drive levels is developing with concern for the extrinsic domain and phase boundary contributions to response. Measurement and modelling are being used to explore the nonlinearity and the frequency response and to examine the phase partitioning at the rhombohedral:tetragonal morphotropic phase boundary in the PZT system. Phenomena limiting lifetime in polarization and phase switching actuators are being explored to separate surface and volume effects and those due to grain size and flaw population differences. New work has been initiated to examine Acoustic Emission as a technique, in combination with Barkhausen current pulse analysis, to separate and evaluate domain switching and microcracking in polarization switching systems.

  20. Piezoelectric properties of Li- and Ta-modified (K0.5Na0.5)NbO3 ceramics

    NASA Astrophysics Data System (ADS)

    Hollenstein, Evelyn; Davis, Matthew; Damjanovic, Dragan; Setter, Nava

    2005-10-01

    Lead-free, potassium sodium niobate piezoelectric ceramics substituted with lithium (K0.5-x/2,Na0.5-x/2,Lix)NbO3 or lithium and tantalum (K0.5-x/2,Na0.5-x/2,Lix)(Nb1-y,Tay)O3 have been synthesized by traditional solid state sintering. The compositions chosen are among those recently reported to show high piezoelectric properties [Y. Saito, H. Takao, T. Tani, T. Nonoyama, K. Takatori, T. Homma, T. Nagaya, and M. Nakamura, Nature (London) 42, 84 (2004); Y. Guo, K. Kakimoto, and H. Ohsato, Appl. Phys. Lett. 85, 4121 (2004); Mater. Lett. 59, 241 (2005)]. We show that high densities and piezoelectric properties can be obtained for all compositions by pressureless sintering in air, without cold isostatic pressing, and without any sintering aid or special powder treatment. Resonance and converse piezoelectric (strain-field) measurements show a thickness coupling coefficient kt of 53% and converse piezoelectric coefficient d33 around 200pm/V for the Li-substituted ceramics, and a kt of 52% and d33 over 300pm/V for the Li- and Ta-modified samples. The unipolar strain-field hysteresis is small and comparable to that measured under similar conditions in hard Pb(Zr ,Ti)O3. A peak of piezoelectric properties can be noted close to the morphotropic phase boundary. These ceramics look very promising as possible, practicable, lead-free replacements for lead zirconate titanate.