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Sample records for pzt composite thick

  1. Research on Composite PZT for Largedisplacement Actuators

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new kind of composite piezoelectric ceramics for large-displacement actuators, which were composed of reduced and unreduced layers, was prepared from normal PZT by chemical reduction. The stress distribution inside the composite PZT was researched and the chemical reduction conditions were explored.The actuating properties of reduced PZT were also studied. It is found that the optimal ratio of reduced layer thickness for the composite structure is 0.3; Reduced composite PZT has lower resonance frequency and 3 times larger displacement than that of the traditional PZT; Re-oxide phases are found in reduced layer of composite PZT showing the reduction procedure needs to be improved.

  2. Oriented Growth of PZT thick film embedded with PZT nanoparticles

    Institute of Scientific and Technical Information of China (English)

    DUAN Zhong-xia; YUAN Jie; ZHAO Quan-liang; LU Ran; CAO Mao-sheng

    2009-01-01

    This paper reports that dense and crack-free (100) oriented lead zirconate titanate (Pb(Zr0.52Ti0.48)O3,PZT) thick film embedded with PZT nanoparticles has been successfully fabricated on Pt/Cr/SiO2/Si substrate by using PT transition layer and PVP additive. The thick film possesses single-phase perovskite structure and perfectly (100) oriented. The (100) orientation degree of the PZT films strongly depended on annealing time and for the 4 μm-thick PZT film which was annealed at 700 ℃ for 5 min is the largest. The (100) orientation degree of the PZT thick film gradually strengthen along with the thickness of film decreasing. The 3 μm-thick PZT thick film which was annealed at 700 ℃ for 5 min has the strongest (100) orientation degree, which is 82. 3%.

  3. Mems-based pzt/pzt bimorph thick film vibration energy harvester

    DEFF Research Database (Denmark)

    Xu, Ruichao; Lei, Anders; Dahl-Petersen, Christian

    2011-01-01

    We describe fabrication and characterization of a significantly improved version of a MEMS-based PZT/PZT thick film bimorph vibration energy harvester with an integrated silicon proof mass. The main advantage of bimorph vibration energy harvesters is that strain energy is not lost in mechanical...... support materials since only PZT is strained, and thus it has a potential for significantly higher output power. An improved process scheme for the energy harvester resulted in a robust fabrication process with a record high fabrication yield of 98.6%. Moreover, the robust fabrication process allowed...... a high pressure treatment of the screen printed PZT thick films prior to sintering, improving the PZT thick film performance and harvester power output reaches 37.1 μW at 1 g....

  4. Screen printed PZT/PZT thick film bimorph MEMS cantilever device for vibration energy harvesting

    DEFF Research Database (Denmark)

    Xu, Ruichao; Lei, Anders; Dahl-Petersen, Christian

    2012-01-01

    We present a microelectromechanical system (MEMS) based PZT/PZT thick film bimorph vibration energy harvester with an integrated silicon proof mass. Most piezoelectric energy harvesting devices use a cantilever beam of a non piezoelectric material as support beneath or in-between the piezoelectri...

  5. Advantages of PZT thick film for MEMS sensors

    DEFF Research Database (Denmark)

    Hindrichsen, Christian Carstensen; Lou-Moller, R.; Hansen, K.;

    2010-01-01

    For all MEMS devices a high coupling between the mechanical and electrical domain is desired. Figures of merit describing the coupling are important for comparing different piezoelectric materials. The existing figures of merit are discussed and a new figure of merit is introduced for a fair...... comparison of piezoelectric thin and thick films based MEMS devices, as cantilevers, beams, bridges and membranes. Simple analytical modeling is used to define the new figure of merit. The relevant figure of merits is compared for the piezoelectric material of interest for MEMS applications: ZnO, AIN, PZT...... thin film and PZT thick film. It is shown that MEMS sensors with the PZT thick film TF2100 from InSensor A/S have potential for significant higher voltage sensitivities compared to PZT thin film base MEMS sensors when the total thickness of the MEMS cantilever, beam, bridge or membrane is high...

  6. MEMS-based thick film PZT vibrational energy harvester

    DEFF Research Database (Denmark)

    Lei, Anders; Xu, Ruichao; Thyssen, Anders

    2011-01-01

    We present a MEMS-based unimorph silicon/PZT thick film vibrational energy harvester with an integrated proof mass. We have developed a process that allows fabrication of high performance silicon based energy harvesters with a yield higher than 90%. The process comprises a KOH etch using a mechan......We present a MEMS-based unimorph silicon/PZT thick film vibrational energy harvester with an integrated proof mass. We have developed a process that allows fabrication of high performance silicon based energy harvesters with a yield higher than 90%. The process comprises a KOH etch using...... a mechanical front side protection of an SOI wafer with screen printed PZT thick film. The fabricated harvester device produces 14.0 μW with an optimal resistive load of 100 kΩ from 1g (g=9.81 m s-2) input acceleration at its resonant frequency of 235 Hz....

  7. Screen printed PZT/PZT thick film bimorph MEMS cantilever device for vibration energy harvesting

    DEFF Research Database (Denmark)

    Xu, Ruichao; Lei, Anders; Christiansen, T.L.

    2011-01-01

    We present a MEMS-based PZT/PZT thick film bimorph vibration energy harvester with an integrated silicon proof mass. The most common piezoelectric energy harvesting devices utilize a cantilever beam of a non piezoelectric material as support beneath or in-between the piezoelectric material....... It provides mechanical support but it also reduces the power output. Our device replaces the support with another layer of the piezoelectric material, and with the absence of an inactive mechanical support all of the stresses induced by the vibrations will be harvested by the active piezoelectric elements....

  8. Fabrication and characterization of MEMS-based PZT/PZT bimorph thick film vibration energy harvesters

    DEFF Research Database (Denmark)

    Xu, Ruichao; Lei, Anders; Dahl-Petersen, Christian

    2012-01-01

    We describe the fabrication and characterization of a significantly improved version of a microelectromechanical system-based PZT/PZT thick film bimorph vibration energy harvester with an integrated silicon proof mass; the harvester is fabricated in a fully monolithic process. The main advantage...... of bimorph vibration energy harvesters is that strain energy is not lost in mechanical support materials since only Pb(ZrxTi1-x)O3 (PZT) is strained; as a result, the effective system coupling coefficient is increased, and thus a potential for significantly higher output power is released. In addition, when...... the two layers are connected in series, the output voltage is increased, and as a result the relative power loss in the necessary rectifying circuit is reduced. We describe an improved process scheme for the energy harvester, which resulted in a robust fabrication process with a record high fabrication...

  9. Presentation and characterization of novel thick-film PZT microactuators

    Energy Technology Data Exchange (ETDEWEB)

    Chalvet, Vincent; Habineza, Didace, E-mail: didace.habineza@femto-st.fr; Rakotondrabe, Micky; Clévy, Cédric

    2016-04-01

    We propose in this paper the characterization of a new generation of piezoelectric cantilevers called thick-films piezoelectric actuators. Based on the bonding and thinning process of a bulk PZT layer onto a silicon layer, these cantilevers can provide better static and dynamic performances compared to traditional piezocantilevers, additionally to the small dimensions.

  10. Triaxial MEMS accelerometer with screen printed PZT thick film

    DEFF Research Database (Denmark)

    Hindrichsen, Christian Carstensen; Almind, Ninia Sejersen; Brodersen, Simon Hedegaard

    2010-01-01

    . In this work integration of a screen printed piezoelectric PZT thick film with silicon MEMS technology is shown. A high bandwidth triaxial accelerometer has been designed, fabricated and characterized. The voltage sensitivity is 0.31 mV/g in the vertical direction, 0.062 mV/g in the horizontal direction...

  11. Piezoelectric and mechanical properties of structured PZT-epoxy composites

    NARCIS (Netherlands)

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

    2013-01-01

    Structured lead zirconium titanate (PZT)-epoxy composites are prepared by dielectrophoresis. The piezoelectric and dielectric properties of the composites as a function of PZT volume fraction are investigated and compared with the corresponding unstructured composites. The effect of poling voltage o

  12. Electromechanical Properties of Microcantilever Actuated by Enhanced Piezoelectric PZT Thick Film

    Institute of Scientific and Technical Information of China (English)

    LIU Hong-Mei; ZHAO Quan-Liang; CAO Mao-Sheng; YUAN Jie; DUAN Zhong-Xia; QIU Cheng-Jun

    2008-01-01

    Pb(Zro.53,Tio.47)O3 (PZT) films with thicknesses of 0.8μm, 2μm and 4μm are prepared by a sol-gel method and their longitudinal piezoelectric coefficients are analysed. The results show that the PZT thick films, whose density is closer to bulk PZT, has the better crystallization, with d33 and density much larger than those of PZT thin films. A piezoelectric microcantilever actuated by a 4-μm-thick PZT film is fabricated and its displacement is measured in different frequencies and voltages. The displacement increases linearly with the increasing bias,and the maximum displacement of 0.544 μm is observed at 30kHz for 5V bias. The resonant frequency obtained in the experiment matches quite well with the theoretical result, and it is shown that the resonant frequency of PZT microcantilever could be controlled and predicated.

  13. Investigation of Top/Bottom electrode and Diffusion Barrier Layer for PZT Thick Film MEMS Sensors

    DEFF Research Database (Denmark)

    Hindrichsen, Christian Carstensen; Pedersen, Thomas; Thomsen, Erik Vilain

    2008-01-01

    Top and bottom electrodes for screen printed piezoelectric lead zirconate titanate, Pb(ZrxTi1 - x)O3 (PZT) thick film are investigated with respect to future MEMS devices. Down to 100 nm thick E-beam evaporated Al and Pt films are patterned as top electrodes on the PZT using a lift-off process...

  14. Directed colloidal assembly and characterization of PZT-polymer composites

    Science.gov (United States)

    Smay, James Earl

    Lead zirconate titanate (PZT)-based layers and 3-D structures were directly assembled using two colloidal routes: (1) tape casting and (2) a layer-by-layer robotic deposition technique, known as robocasting. First, concentrated (φsolids > 0.45) suspensions of PZT-5H and a latex emulsion were tape cast with the aid of viscosifier and surfactant additions. Drying stress evolved to a maximum at φ PZT ˜ 0.49, followed by a reduction and a secondary stress rise attributed to latex coalescence. Dielectric and piezoelectric properties of sintered PZT multilayer laminates exhibited good agreement with those for isostatically pressed and sintered samples. Concentrated, weakly gelled suspensions of PZT 95/5 and poly(ethylene) (PE) latices, a fugitive species, were developed as inks for the robotic deposition of monolithic and tri-layered composite structures. Monoliths, with densities of 93.6% and 96.1%, and composites with a 96.1% dense layer between 93.6% regions were fabricated. The structures displayed equivalent electrical properties to cold isostatically pressed parts. The composites withstood repeated saturation polarization switching as well as a 500 MPa hydrostatic pressure-induced poled ferroelectric (FE) to antiferroelectric (AFE) phase transformation. Concentrated (φPZT = 0.47) PZT-5H gels were developed as inks for the robotic deposition of 3-D, mesoscale periodic structures with self-supporting features such as lattices of rod-like elements and v-shaped test structures. The gels exhibited pH dependent viscoelastic properties and Hershel-Bulkley flow behavior. The deflection of as-deposited spanning elements was measured using laser profilometry. Flow modeling and shape evolution data indicated a core-shell architecture as the ink exited the deposition nozzle, which simultaneously provided strength to form spanning elements and good bonding between layers. The core grew rapidly (˜1s) due to the quick recovery of gel structure in these inks. 3-X type PZT

  15. Enhanced off-resonance magnetoelectric response in laser annealed PZT thick film grown on magnetostrictive amorphous metal substrate

    Energy Technology Data Exchange (ETDEWEB)

    Palneedi, Haribabu [Materials Interface Laboratory, Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701 (Korea, Republic of); Functional Ceramics Group, Korea Institute of Materials Science (KIMS), Changwon 641-831 (Korea, Republic of); Maurya, Deepam; Priya, Shashank [Bio-inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States); Kim, Gi-Yeop; Choi, Si-Young, E-mail: youngchoi@kims.re.kr [Materials Modeling and Characterization Department, Korea Institute of Materials Science (KIMS), Changwon 641-831 (Korea, Republic of); Kang, Suk-Joong L. [Materials Interface Laboratory, Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701 (Korea, Republic of); Kim, Kwang-Ho [School of Materials Science and Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Ryu, Jungho, E-mail: jhryu@kims.re.kr [Functional Ceramics Group, Korea Institute of Materials Science (KIMS), Changwon 641-831 (Korea, Republic of)

    2015-07-06

    A highly dense, 4 μm-thick Pb(Zr,Ti)O{sub 3} (PZT) film is deposited on amorphous magnetostrictive Metglas foil (FeBSi) by granule spray in vacuum process at room temperature, followed by its localized annealing with a continuous-wave 560 nm ytterbium fiber laser radiation. This longer-wavelength laser radiation is able to anneal the whole of thick PZT film layer without any deteriorative effects, such as chemical reaction and/or atomic diffusion, at the interface and crystallization of amorphous Metglas substrate. Greatly enhanced dielectric and ferroelectric properties of the annealed PZT are attributed to its better crystallinity and grain growth induced by laser irradiation. As a result, a colossal off-resonance magnetoelectric (ME) voltage coefficient that is two orders of magnitude larger than previously reported output from PZT/Metglas film-composites is achieved. The present work addresses the problems involved in the fabrication of PZT/Metglas film-composites and opens up emerging possibilities in employing piezoelectric materials with low thermal budget substrates (suitable for integrated electronics) and designing laminate composites for ME based devices.

  16. Enhanced off-resonance magnetoelectric response in laser annealed PZT thick film grown on magnetostrictive amorphous metal substrate

    Science.gov (United States)

    Palneedi, Haribabu; Maurya, Deepam; Kim, Gi-Yeop; Priya, Shashank; Kang, Suk-Joong L.; Kim, Kwang-Ho; Choi, Si-Young; Ryu, Jungho

    2015-07-01

    A highly dense, 4 μm-thick Pb(Zr,Ti)O3 (PZT) film is deposited on amorphous magnetostrictive Metglas foil (FeBSi) by granule spray in vacuum process at room temperature, followed by its localized annealing with a continuous-wave 560 nm ytterbium fiber laser radiation. This longer-wavelength laser radiation is able to anneal the whole of thick PZT film layer without any deteriorative effects, such as chemical reaction and/or atomic diffusion, at the interface and crystallization of amorphous Metglas substrate. Greatly enhanced dielectric and ferroelectric properties of the annealed PZT are attributed to its better crystallinity and grain growth induced by laser irradiation. As a result, a colossal off-resonance magnetoelectric (ME) voltage coefficient that is two orders of magnitude larger than previously reported output from PZT/Metglas film-composites is achieved. The present work addresses the problems involved in the fabrication of PZT/Metglas film-composites and opens up emerging possibilities in employing piezoelectric materials with low thermal budget substrates (suitable for integrated electronics) and designing laminate composites for ME based devices.

  17. PMN-PT-PZT composite films for high frequency ultrasonic transducer applications.

    Science.gov (United States)

    Hsu, Hsiu-Sheng; Benjauthrit, Vatcharee; Zheng, Fan; Chen, Rumin; Huang, Yuhong; Zhou, Qifa; Shung, K Kirk

    2012-06-01

    We have successfully fabricated x(0.65PMN-0.35PT)-(1 - x)PZT (xPMN-PT-(1 - x)PZT), where x is 0.1, 0.3, 0.5, 0.7 and 0.9, thick films with a thickness of approximately 9 µm on platinized silicon substrate by employing a composite sol-gel technique. X-ray diffraction analysis and scanning electron microscopy revealed that these films are dense and creak-free with well-crystallized perovskite phase in the whole composition range. The dielectric constant can be controllably adjusted by using different compositions. Higher PZT content of xPMN-PT-(1 - x)PZT films show better ferroelectric properties. A representative 0.9PMN-PT-0.1PZT thick film transducer is built. It has 200 MHz center frequency with a -6 dB bandwidth of 38% (76 MHz). The measured two-way insertion loss is 65 dB.

  18. Processing effects for integrated PZT: Residual stress, thickness, and dielectric properties

    Science.gov (United States)

    Ong, Ryan Jason

    This dissertation focuses on the integration of lead zirconate titanate (PZT) films on Pt/Ti/SiO2//Si, and the effect of on properties. Direct deposition of PZT on Si will lead to on-chip power capacitors, non-volatile memory cells, and vibration sensors. However, previous research indicates that the dielectric, ferroelectric and piezoelectric response characteristics for the devices are often inferior to bulk specimens. Property variations have been attributed to changes in several major variables including, chemical composition, phase content, grain size, crystallographic orientation, film thickness, and stress, each of which, in turn, can depend on processing. The first goal of this work was to design a sol-gel processing methodology to control all major variables except film thickness and stress, thus isolating their respective effects on properties. All specimens were verified to be of the Pb(Zr0.53Ti0.47)O3 composition, in the perovskite structure, with a constant grain size of 110nm, and with (111) fiber texture. PZT film thickness was varied from 95nm to 500nm and residual stress was measured to be either 150 or 180MPa, biaxial tensile, depending on thickness. These specimens allowed for new insights into the fundamental differences between bulk materials and thin films. A series-capacitor model accounted for the observed dilution in room-temperature K from >900 to ˜600 as film thickness decreased, but could not account for the absence of the expected dielectric anomaly at high temperatures. Instead, a stress-induced distributed phase transformation related to the polycrystalline nature of the film was proposed to account for the observed behavior. Residual stress reduced the spontaneous polarization values in these specimens to 32muC/cm 2 from the predicted stress-free value of 50muC/cm2. An increase in coercive field was attributed to interfacial capacitance and residual stress, whereas a decrease of 30MPa tensile stress resulted in an increase of d33

  19. Study of pyroelectric activity of PZT/PVDF-HFP composite

    Directory of Open Access Journals (Sweden)

    Luiz Francisco Malmonge

    2003-12-01

    Full Text Available Flexible, free-standing piezo and pyroelectric composite with 0 to 3 connectivity was made up from Lead Zirconate Titanate (PZT powder and poly(vinylidene fluoride-hexafluoropropylene (PVDF-HFP copolymer. The pyroelectric and the piezoelectric longitudinal (d33 coefficients were measured. A 50/50 vol.% PZT/PVDF-HFP composite resulted in piezo and pyroelectric coefficients of d33 = 25.0 pC/N and p = 4.5 × 10-4 C/m²K at 70 °C, respectively. Analysis of the complex permittivity in a wide range of frequency was carried out indicating lower permittivity of the composite in comparison with a permittivity of the PZT ceramic. The low value of the permittivity gives a high pyroelectric figure of merit indicating that this material can be used to build a temperature sensor in spite of the lower pyroelectric coefficient compared with PZT.

  20. Adjustability of resonance frequency by external magnetic field and bias electric field of sandwich magnetoelectric PZT/NFO/PZT composites

    Science.gov (United States)

    Xu, Ling-Fang; Feng, Xing; Sun, Kang; Liang, Ze-Yu; Xu, Qian; Liang, Jia-Yu; Yang, Chang-Ping

    2017-07-01

    Sandwich magnetoelectric composites of PZT/NFO/PZT (PNP) have been prepared by laminating PZT5, NiFe2O4, and PZT5 ceramics in turn with polyvinyl alcohol (PVA) paste. A systematic study of structural, magnetic and ferroelectric properties is undertaken. Structural studies carried out by X-ray diffraction indicate formation of cubic perovskite phase of PZT5 ceramic and cubic spinel phase of NiFe2O4 ceramic. As increasing the content of PZT5 phase, ferroelectric loops and magnetic loops of PNP composites showed increasing remnant electric polarizations and decreasing remnant magnetic moments separately. Both external magnetic fields and bias voltages could regulate the basal radial resonance frequency of the composites, which should be originated with the transformation and coupling of the stress between the piezoelectric phase and magnetostrictive phase. Such magnetoelectric composite provides great opportunities for electrostatically tunable devices.

  1. Investigation of top electrode for PZT thick films based MEMS sensors

    DEFF Research Database (Denmark)

    Hindrichsen, Christian Carstensen; Pedersen, Thomas; Kristiansen, Paw T.;

    2010-01-01

    In this work processing of screen printed piezoelectric PZT thick films on silicon substrates is investigated for use in future MEMS devices. E-beam evaporated Al and Pt are patterned on PZT as a top electrode using a lift-off process with a line width down to 3 mu m. Three test structures are used...

  2. Study of pyroelectric activity of PZT/PVDF-HFP composite

    OpenAIRE

    Luiz Francisco Malmonge; José Antonio Malmonge; Walter Katsumi Sakamoto

    2003-01-01

    Flexible, free-standing piezo and pyroelectric composite with 0 to 3 connectivity was made up from Lead Zirconate Titanate (PZT) powder and poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) copolymer. The pyroelectric and the piezoelectric longitudinal (d33) coefficients were measured. A 50/50 vol.% PZT/PVDF-HFP composite resulted in piezo and pyroelectric coefficients of d33 = 25.0 pC/N and p = 4.5 × 10-4 C/m²K at 70 °C, respectively. Analysis of the complex permittivity in a wide ran...

  3. A new traveling wave ultrasonic motor using thick ring stator with nested PZT excitation.

    Science.gov (United States)

    Chen, Weishan; Shi, Shengjun; Liu, Yingxiang; Li, Pei

    2010-05-01

    To avoid the disadvantages of conventional traveling wave ultrasonic motors--lower efficiency PZT working mode of d(31), fragility of the PZT element under strong excitation, fatigue of the adhesive layer under harsh environmental conditions, and low volume of the PZT material in the stator--a new type of traveling wave ultrasonic motor is presented in this paper. Here we implement the stator by nesting 64 PZT stacks in 64 slots specifically cut in a thick metal ring and 64 block springs nested within another 64 slots to produce preloading on the PZT stacks. In this new design, the d33 mode of the PZT is used to excite the flexural vibrations of the stator, and fragility of the PZT ceramics and fatigue of the adhesive layer are no longer an issue. The working principle, FEM simulation, fabrication, and performance measurements of a prototype motor were demonstrated to validate the proposed ideas. Typical output of the prototype motor is no-load speed of 15 rpm and maximum torque of 7.96 N x m. Further improvement will potentially enhance its features by increasing the accuracy in fabrication and adopting appropriate frictional material into the interface between the stator and the rotor.

  4. Characterization of PZT/PVC Composites Added with Carbon Black

    Institute of Scientific and Technical Information of China (English)

    LIU Xiaofang; XIONG Chuanxi; SUN Huajun; DONG Lijie; LI Rui; LIU Yang

    2005-01-01

    A new three-phase PZT/ C/ PVC composite comprising PZT (50vol%), nanocrystalline PVC (50 vol% ) and a small volume fraction f of carbon black (C) was prepared by the hot-pressing technique. The dielectric property of the composite as a function of the frequency and the dielectric and piezoelectric properties as a function of the volume fraction f of C were studied. The measured dielectric property demonstrates that a percolation transition occurs in the three-phase composites as in normal two-phase metal-insulator continuum media. The dielectric constant varies slightly with f at f < 0.1 and increases rapidly when f is close to the percolation threshold at 1 kHz. The optimum properties were obtained for f = 0.5 before the percolation threshold in the PZT/ C/ PVC (50/f/(50 - f) vol% ) composite with its d33 (20 pC/N) being 50% higher than that of the PZT/ PVC (50/50vol% ), and its g33(47.23 × 10-3 Vm/N) and Kp (0.25) much higher than the earlier reported values.XRD patterns and P-E hysteresis loops were used to interpret the experimental results.

  5. Giant magnetoelectric effects in ferrite - PZT multilayer composites

    Science.gov (United States)

    Srinivasan, G.; Rasmussen, E. T.

    2002-03-01

    Materials that respond to both electric and magnetic fields are said to be magnetoelectric (ME) and facilitate field conversion. One way in principle to accomplish strong ME effects is a composite of magnetostrictive and piezoelectric materials in which the coupling is mediated by mechanical deformation. This report is on the synthesis of novel multilayers of magnetostrictive nickel zinc ferrite (NZFO) and piezoelectric lead zirconate titanate (PZT) that show a giant ME effect and maximum field conversion efficiency [1]. Bilayers and multilayers were prepared from thick films obtained by tape casting. The ME voltage coefficient was measured as a function of sample and experimental parameters. The coefficient ranged from 30 to 1500 mV/cm Oe, depending on the sample composition, volume fraction, and field orientation. The transverse coupling is an order of magnitude stronger than the longitudinal coefficient. The ME coefficient is maximum at room temperature and increases with increasing frequency. Data on the dependence of ME coupling on volume fraction of the two phases and bias magnetic field are in excellent agreement with theoretical predictions. - work supported by a grant from the NSF (DMR-0072144) 1. G. Srinivasan, E. T. Rasmussen, J. Gallegos, R. Srinivasan, Yu. I. Bokhan, and V. M. Laletin, Phys. Rev. B 64, 214408 (2001).

  6. Dielectric properties of novel polyurethane-PZT-graphite foam composites

    Science.gov (United States)

    Tolvanen, Jarkko; Hannu, Jari; Nelo, Mikko; Juuti, Jari; Jantunen, Heli

    2016-09-01

    Flexible foam composite materials offer multiple benefits to future electronic applications as the rapid development of the electronics industry requires smaller, more efficient, and lighter materials to further develop foldable and wearable applications. The aims of this work were to examine the electrical properties of three- and four-phase novel foam composites in different conditions, find the optimal mixture for four-phase foam composites, and study the combined effects of lead zirconate titanate (PZT) and graphite fillers. The flexible and highly compressible foams were prepared in a room-temperature mixing process using polyurethane, PZT, and graphite components as well as their combinations, in which air acted as one phase. In three-phase foams the amount of PZT varied between 20 and 80 wt% and the amount of graphite, between 1 and 15 wt%. The four-phase foams were formed by adding 40 wt% of PZT while the amount of graphite ranged between 1 and 15 wt%. The presented results and materials could be utilized to develop new flexible and soft sensor applications by means of material technology.

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

    NARCIS (Netherlands)

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

    2014-01-01

    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

  8. Low Temperature Processing of Nanocrystalline Lead Zirconate Titanate (PZT) Thick Films and Ceramics by a Modified Sol-Gel Route

    Science.gov (United States)

    Zhu, Weiguang; Wang, Zhihong; Zhao, Changlei; Tan, Ooi Kiang; Hng, Huey Hoon

    2002-11-01

    Dispersing fine particles into a sol-gel matrix is a promising process to get a thick 0-3 composite coating layer. In this paper, we have further improved this modified sol-gel process by nanocrystalline composite technique to realize the low temperature annealing. Dense Pb(Zr, Ti)O3 (PZT) thick films of 10 to 50 μm in thickness have been obtained on the platinum-coated silicon substrates by spin-coating at sintering temperature of 600-700°C and fully developed submicron-sized grains have been demonstrated in screen-printing piezoelectric films on alumina substrates at sintering temperature of 700-800°C. The dependence of various properties such as microstructure, crystallization, ferroelectric and dielectric properties of such made thick films on the processing parameters have been investigated. For a 10 μm-thick film spin-coated on silicon wafer, the dielectric loss and relative permittivity are 0.010 and 1024, respectively, at 1 kHz. The remanent polarization (Pr) and the coercive field (Ec) are 13.6 μC/cm2 and 34.5 kV/cm, respectively. Obviously, such made thick film has comparable properties with bulk PZT ceramic. This novel technique can be extensively used in sol-gel, screen-printing, tape-casting, even in traditional ceramic process to reduce the process temperature.

  9. The Fabrication and Characterization of Piezoelectric PZT/PVDF Electrospun Nanofiber Composites

    Directory of Open Access Journals (Sweden)

    Ji Sun Yun

    2016-03-01

    Full Text Available Piezoelectric nanofiber composites of polyvinylidene fluoride (PVDF polymer and PZT (Pb(Zr0.53Ti0.47O3 ceramics were fabricated by electrospinning. The micro‐ structure of the PZT/PVDF electrospun nanofiber compo‐ sites was characterized using X-ray diffraction (XRD, scanning electron microscopy (SEM and transmission electron microscopy (TEM. The tensile properties (stress- strain curves and electrical properties (P-E hysteresis loops of the PZT/PVDF electrospun nanofiber composites were investigated as a function of PZT content from 0 wt% to 30 wt%. The results demonstrated that a PZT content of 20 wt % had enhanced tensile and piezoelectric characteristics.

  10. Investigation of Top/bottom Electrode and Diffusion Barrier Layer for PZT thick film MEMS Sensors

    DEFF Research Database (Denmark)

    Pedersen, Thomas; Hindrichsen, Christian Carstensen; Lou-Møller, R.

    2007-01-01

    In this work screen printed piezoelectric Ferroperm PZ26 lead zirconate titanate (PZT) thick film is used for two MEMS devices. A test structure is used to investigate several aspects regarding bottom and top electrodes. 450 nm ZrO2 thin film is found to be an insufficient diffusion barrier layer...

  11. Fabrication and characterization of micromachined high-frequency tonpilz transducers derived by PZT thick films.

    Science.gov (United States)

    Zhou, Qifa; Cannata, Jonathan M; Meyer, Richard J; van Tol, David J; Tadigadapa, Srinivas; Hughes, W Jack; Shung, K Kirk; Trolier-McKinstry, Susan

    2005-03-01

    Miniaturized tonpilz transducers are potentially useful for ultrasonic imaging in the 10 to 100 MHz frequency range due to their higher efficiency and output capabilities. In this work, 4 to 10-microm thick piezoelectric thin films were used as the active element in the construction of miniaturized tonpilz structures. The tonpilz stack consisted of silver/lead zirconate titanate (PZT)/lanthanum nickelate (LaNiO3)/silicon on insulator (SOI) substrates. First, conductive LaNiO3 thin films, approximately 300 nm in thickness, were grown on SOI substrates by a metalorganic decomposition (MOD) method. The room temperature resistivity of the LaNiO3 was 6.5 x 10(-6) omega x m. Randomly oriented PZT (52/48) films up to 7-microm thick were then deposited using a sol-gel process on the LaNiO3-coated SOI substrates. The PZT films with LaNiO3 bottom electrodes showed good dielectric and ferroelectric properties. The relative dielectric permittivity (at 1 kHz) was about 1030. The remanent polarization of PZT films was larger than 26 microC/cm2. The effective transverse piezoelectric e31,f coefficient of PZT thick films was about -6.5 C/m2 when poled at -75 kV/cm for 15 minutes at room temperature. Enhanced piezoelectric properties were obtained on poling the PZT films at higher temperatures. A silver layer about 40-microm thick was prepared by silver powder dispersed in epoxy and deposited onto the PZT film to form the tail mass of the tonpilz structure. The top layers of this wafer were subsequently diced with a saw, and the structure was bonded to a second wafer. The original silicon carrier wafer was polished and etched using a Xenon difluoride (XeF2) etching system. The resulting structures showed good piezoelectric activity. This process flow should enable integration of the piezoelectric elements with drive/receive electronics.

  12. The Fabrication and Characterization of Piezoelectric PZT/PVDF Electrospun Nanofiber Composites

    OpenAIRE

    Ji Sun Yun; Chun Kil Park; Young Hun Jeong; Jeong Ho Cho; Jong-Hoo Paik; Sun Hong Yoon; Kyung-Ran Hwang

    2016-01-01

    Piezoelectric nanofiber composites of polyvinylidene fluoride (PVDF) polymer and PZT (Pb(Zr0.53Ti0.47)O3) ceramics were fabricated by electrospinning. The micro‐ structure of the PZT/PVDF electrospun nanofiber compo‐ sites was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The tensile properties (stress- strain curves) and electrical properties (P-E hysteresis loops) of the PZT/PVDF electrospun nanofiber composites w...

  13. Numerical analysis for structural health monitoring of a damaged composite panel using PZT actuators and sensors

    Science.gov (United States)

    Nagabhushana, A.; Spiegel, M.; Adu, S.; Hayes, N.; Paul, D.; Trivedi, K.; Fairbee, B.; Zheng, H.; Gerrity, A.; Kotru, S.; Roy, S.; Barkey, M.; Burkett, S. L.

    2012-04-01

    Reliable damage detection is crucial for assessing the integrity of a structure. In this paper, a numerical study of a composite panel fabricated to simulate a crack is undertaken using finite element methods (FEM). The damage to be considered is a transverse crack which pre-exists in the structure. The finite element models are developed for an undamaged and a damaged composite panel to compute the change in Lamb wave response due to the existence of a crack. The model is validated using shear lag analysis applied at the crack. The results are verified experimentally by comparing the results for an undamaged composite panel and a composite panel fabricated with a simulated crack using the vacuum assisted resin transfer molding (VARTM) process. The responses for each panel are obtained using surface mounted lead zirconate titanate (PZT) actuators and sensors. PZT is used to generate Lamb waves which produce stress throughout the panel thickness. Propagation characteristics of Lamb waves are varied by the presence of damage. The sensor data provide reliable information about the integrity of the structure. Numerical results are compared to the sensor output to ensure accuracy of the damage detection system.

  14. Fabrication and Characterization of PZT Thick Films for Sensing and Actuation

    Directory of Open Access Journals (Sweden)

    Kuo-Ching Kuo

    2007-04-01

    Full Text Available Lead Zirconate Titanate oxide (PZT thick films with thicknesses of up to 10 μmwere developed using a modified sol-gel technique. Usually, the film thickness is less than1 μm by conventional sol-gel processing, while the electrical charge accumulation whichreveals the direct effect of piezoelectricity is proportional to the film thickness and thereforerestricted. Two approaches were adopted to conventional sol-gel processing – precursorconcentration modulation and rapid thermal annealing. A 10 μm thick film was successfullyfabricated by coating 16 times via this technique. The thickness of each coating layer wasabout 0.6 μm and the morphology of the film was dense with a crack-free area as large as 16mm2. In addition, the structure, surface morphology and physical properties werecharacterized by X-ray diffraction (XRD, scanning electron microscopy (SEM and atomicforce microscopy (AFM and electrical performance. The dielectric constant and hysteresisloops were measured as electric characteristics. This study investigates the actuation andsensing performance of the vibrating structures with the piezoelectric thick film. Theactuation tests demonstrated that a 4 mm x 4 mm x 6.5 μm PZT film drove a 40 mm x 7 mmx 0.5 mm silicon beam as an actuator. Additionally, it generated an electrical signal of 60mVpp as a sensor, while vibration was input by a shaker. The frequencies of the first twomodes of the beam were compared with the theoretical values obtained by Euler-Bernoullibeam theory. The linearity of the actuation and sensing tests were also examined.

  15. Properties of PZT thick film made on LTCC substrates with dielectric intermediate layers

    Science.gov (United States)

    DÄ browski, Arkadiusz; Golonka, Leszek

    2016-11-01

    Results of experiments on application of various interlayers between LTCC (Low Temperature Cofired Ceramics) substrate and thick-film PZT (Lead Zirconate - Titanate) are described in this work. Thick-film intermediate layers were based on several dielectric materials: TiN, Al2O3, SiC, TiO2, SiC, YSZ, BN. Seven screen printable pastes were prepared on the base of powders of mentioned materials with addition of glass and organic vehicle. The substrates were made of 951 (DuPont), CeramTapeGC (CeramTec) and HL2000 (Heraeus) LTCC tapes. Sandwich type transducers, consisting of barrier layer, gold bottom electrode, PZT layer and silver top electrode were prepared and characterized. Basic piezoelectric parameters - permittivity, effective charge constant (d33(eff)) and remanent polarization were determined. The best properties were obtained for substrates made of 951. In general, interlayers based on TiO2, SiC and Al2O3 improved permittivity and charge constant comparing to bare substrates. For example, for 951 substrate the PZT layer exhibited d33(eff) equal to 160, 215, 250 and 230 pC/N for bare substrate, TiO2 interlayer, SiC interlayer and Al2O3 interlayer, respectively. In case of CeramTape GC substrates determined permittivity was equal to 215, 245, 235 and 275 for bare substrate, TiO2 interlayer, SiC interlayer and Al2O3 interlayer, respectively. In case of TiN and BN materials the parameters were considerably deteriorated.

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

    Science.gov (United States)

    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.

  17. Synthesis and dielectric properties of ferroelectric-ferrimagnetic PZT-SFMO composites

    Directory of Open Access Journals (Sweden)

    Alexander V. Petrov

    2017-03-01

    Full Text Available Ferrimagnetic-ferroelectric composite materials on the base of Pb0.85Zr0.53Ti0.47O3– Sr2FeMoO6–δ (PZT-SFMO compounds have been prepared by a complex ceramic technology and a modified sol-gel synthesis. The dielectric properties of the PZT-SFMO composites with the PZT concentrations of 55 wt% and less, as well as of pure SFMO, are caused by the Maxwell-Wagner relaxation and a huge electrical conductivity. In contrast, in pure PZT the ferroelectric phase transition is clearly expressed in the static dielectric permittivity anomaly. Moreover, in all investigated composites, similarly to pure SFMO, the electrical conductivity anomaly is observed in the range from 560–540 K. This indicates that the composites with PZT concentrations of 55 wt% and higher are above the electrical and magnetic percolation threshold, in a good agreement with the excluded volume theory. In PZT-SFMO composites the DC electrical conductivity increases with SFMO concentration almost in a power law fashion, while the activation energy of the DC conductivity decreases under certain conditions.

  18. PZT-Polymer 1-3 Composite for High Resolution Ultrasonic Imaging

    Institute of Scientific and Technical Information of China (English)

    Shinan Wang; Jing-Feng Li; Katsuhiro Wakabayashi; Masayoshi Esashi

    2000-01-01

    @@ A novel process has been developed to construct PZT-polymer 1-3 micro composites for high-resolution ultrasonic imaging for medical diagnosis. The key technology is the lost silicon (Si) mold process, by which PZT micro-rod arrays have been successfully fabricated with the finest rod size being 7 μm, the highest aspect ratio exceeding 15. Such fine-scale high-aspect-ratio PZT structures, which are essential for realizing high imaging performance, have never been realized by any conventional technique.

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

    Science.gov (United States)

    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

  20. Importance of composite parameters in enhanced power conversion efficiency of Terfenol-D/PZT magnetoelectric gyrators

    Science.gov (United States)

    Leung, Chung Ming; Zhuang, Xin; Xu, Junran; Li, Jiefang; Srinivasan, G.; Viehland, D.

    2017-03-01

    A gyrator that is capable of current-to-voltage conversion can be realized with a magnetoelectric (ME) composite of ferromagnetic and ferroelectric phases placed in a coil. Here, we report the dependence of the power conversion efficiency (PE) on the relative thickness of the two ferroic phases in a gyrator of Terfenol-D and PZT. Both experimental and theoretical results on PE as a function of composite parameters, such as thickness ratio of the ferroic layers (n), magnetic field bias (HBias) and several gyrator parameters, such as the resistance load (RL), were discussed. By decreasing the thickness ratio of Terfenol-D to composite (n = 0.28) in coil-ME gyrators, a high power efficiency of 73.9% was found at a fundamental resonance frequency of 72.5 kHz under a HBias of 1000 Oe and RL = 2.6 kΩ in experiments. At the same time, the non-linear mechanical loss was reduced by decreasing the value of n which resulted in a flat response over a wide HBias range. This improved power efficiency promises ME gyrators for power transfer devices.

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

    Science.gov (United States)

    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.

  2. Micro-particle manipulation by single beam acoustic tweezers based on hydrothermal PZT thick film

    Directory of Open Access Journals (Sweden)

    Benpeng Zhu

    2016-03-01

    Full Text Available Single-beam acoustic tweezers (SBAT, used in laboratory-on-a-chip (LOC device has promising implications for an individual micro-particle contactless manipulation. In this study, a freestanding hydrothermal PZT thick film with excellent piezoelectric property (d33 = 270pC/N and kt = 0.51 was employed for SBAT applications and a press-focusing technology was introduced. The obtained SBAT, acting at an operational frequency of 50MHz, a low f-number (∼0.9, demonstrated the capability to trap and manipulate a micro-particle sized 10μm in the distilled water. These results suggest that such a device has great potential as a manipulator for a wide range of biomedical and chemical science applications.

  3. Micro-particle manipulation by single beam acoustic tweezers based on hydrothermal PZT thick film

    Science.gov (United States)

    Zhu, Benpeng; Xu, Jiong; Li, Ying; Wang, Tian; Xiong, Ke; Lee, Changyang; Yang, Xiaofei; Shiiba, Michihisa; Takeuchi, Shinichi; Zhou, Qifa; Shung, K. Kirk

    2016-01-01

    Single-beam acoustic tweezers (SBAT), used in laboratory-on-a-chip (LOC) device has promising implications for an individual micro-particle contactless manipulation. In this study, a freestanding hydrothermal PZT thick film with excellent piezoelectric property (d33 = 270pC/N and kt = 0.51) was employed for SBAT applications and a press-focusing technology was introduced. The obtained SBAT, acting at an operational frequency of 50MHz, a low f-number (∼0.9), demonstrated the capability to trap and manipulate a micro-particle sized 10μm in the distilled water. These results suggest that such a device has great potential as a manipulator for a wide range of biomedical and chemical science applications. PMID:27014504

  4. Homogeneity Analysis of a MEMS-based PZT Thick Film Vibration Energy Harvester Manufacturing Process

    DEFF Research Database (Denmark)

    Lei, Anders; Xu, Ruichao; Borregaard, Louise M.

    2012-01-01

    This paper presents a homogeneity analysis of a high yield wafer scale fabrication of MEMS-based unimorph silicon/PZT thick film vibration energy harvesters aimed towards vibration sources with peak vibrations in the range of around 300Hz. A wafer with a yield of 91% (41/45 devices) has been...... indicating that the main variation in open circuit voltage performance is caused by varying quality factor. The average resonant frequency was measured to 333Hz with a standard variation of 9.8Hz and a harvesting bandwidth of 5-10Hz. A maximum power output of 39.3μW was achieved at 1g for the best performing...

  5. Micro-particle manipulation by single beam acoustic tweezers based on hydrothermal PZT thick film

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Benpeng, E-mail: benpengzhu@hust.edu.cn [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China); State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Xu, Jiong; Yang, Xiaofei [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China); Li, Ying; Lee, Changyang; Zhou, Qifa; Shung, K. Kirk [Department of Biomedical Engineering and NIH Transducer Resource Center, University of Southern California, Los Angeles, California 90089-1111 (United States); Wang, Tian; Xiong, Ke [Department of Physics and Key Laboratory of Acoustic and Photonic Materials and Devices of Ministry of Education, Wuhan University, Wuhan 430072 (China); Shiiba, Michihisa; Takeuchi, Shinichi [Medical Engineering Course, Graduate School of Engineering, Toin University of Yokohama, Yokohama 225-8501 (Japan)

    2016-03-15

    Single-beam acoustic tweezers (SBAT), used in laboratory-on-a-chip (LOC) device has promising implications for an individual micro-particle contactless manipulation. In this study, a freestanding hydrothermal PZT thick film with excellent piezoelectric property (d{sub 33} = 270 pC/N and k{sub t} = 0.51) was employed for SBAT applications and a press-focusing technology was introduced. The obtained SBAT, acting at an operational frequency of 50 MHz, a low f-number (∼0.9), demonstrated the capability to trap and manipulate a micro-particle sized 10μm in the distilled water. These results suggest that such a device has great potential as a manipulator for a wide range of biomedical and chemical science applications.

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

    Science.gov (United States)

    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.

  7. Optimization of composition and crystal structure for processing route of PZT system

    Energy Technology Data Exchange (ETDEWEB)

    Kakimoto, K.; Kakemoto, H.; Fujita, S.; Masuda, Y. [Hachinohe Inst. of Tech., Aomori (Japan). JSPS Research Project

    2002-07-01

    An evaluation procedure that employs by calibrated X-ray fluorescence (XRF) analysis of the chemical composition of PZT bulk ceramics and thin films deposited on Si-based substrate by the pulsed laser deposition (PLD) technique has been established. The plots of cation fraction and XRF intensity for Pb, Zr and Ti atoms were curve-fitted using the results obtained by XRF measurement of normalized PZT samples whose compositions were selected from those near the morphotropic phase boundary (MPB) of PZT(Zr/Ti=53/47). While the Pb curve was almost linear, Zr and Ti yielded parabolic curves due to the effect of matrix Pb. In the case of thin-film analysis, the substrate beneath the thin film exerted a matrix effect on the quantitative analysis of the thin film. Both the coexisting element effect and the substrate effect were calibrated to prepare an excellent XRF table for the precise quantitative analysis of PZT thin films. The present XRF table quantitatively revealed a variation in PZT composition during the high-temperature sintering process of bulk and even its thin-film prepared by PLD. The combination of X-ray diffraction (XRD) with model calculation also supported quantitative XRF analysis of the compositional difference from Pb stoichiometry. (orig.)

  8. Thickness dependence of electrical properties of PZT films deposited on metal substrates by laser-assisted aerosol deposition.

    Science.gov (United States)

    Baba, S; Tsuda, H; Akedo, J

    2008-05-01

    Dependence of electrical properties-dielectric, ferroelectric, and piezoelectric properties-on film thickness was studied for lead-zirconate titanate (PZT) thick films directly deposited onto stainless-steel (SUS) substrates in actuator devices by using a carbon dioxide (CO(2) ), laser assisted aerosol deposition technique. Optical spectroscopic analysis data and laser irradiation experiments revealed that absorption at a given wavelength by the film increased with increasing film thickness. Dielectric constant epsilon, remanent polarization value P(r), and coercive field strength E(c) of PZT films directly deposited onto a SUS-based piezoelectric actuator substrate annealed by CO(2) laser irradiation at 850 degrees C improved with increasing film thickness, and for films thicker than 25 microm, epsilon 800, P(r) 40 microC/cm(2), and E(c) 45 kV/cm. In contrast, the displacement of the SUS-based actuator with the laser-annealed PZT thick film decreased with increasing film thickness.

  9. Evaluation of the effect of porosity and substrate on the piezoelectric behaviour of thick-film PZT elements

    Energy Technology Data Exchange (ETDEWEB)

    Gwirc, S N [Instituto Nacional de TecnologIa Industrial, Electronica e Informatica, CC 157, B1650WAB San Martin, Buenos Aires (Argentina); Negreira, C A [Instituto de Fisica, Laboratorio de Acustica Ultrasonora, Facultad de Ciencias, Igua 4225, 11400 Montevideo (Uruguay)

    2006-10-07

    This work presents a method to establish the elastic and piezoelectric constants of a thick film screen printed PZT composite over an alumina substrate. The calculus procedure uses as input data the parameters from the bulk material because it is basically the same component of which the thick film paste is manufactured. We also need to know frequencies of resonance and anti-resonance as well as the permittivity and density of the film in a poled disc sample. This method takes into account three factors: the additional components such as the glass frit, porosity of the film caused by the low temperature sinter process and the film clamping to the substrate. Each one of these factors reduces the piezoelectric efficiency by a different amount and, consequently, the measured values of the constants. The results obtained in this way are compared with experimental measurements of the effective piezoelectric charge constant d{sub 33} and permittivity with good agreement. Small discrepancies could be explained mainly due to lack of homogeneity in glass as well as in pore distribution.

  10. Homogeneity analysis of high yield manufacturing process of mems-based pzt thick film vibrational energy harvesters

    DEFF Research Database (Denmark)

    Lei, Anders; Xu, Ruichao; Pedersen, C.M.

    2011-01-01

    This work presents a high yield wafer scale fabrication of MEMS-based unimorph silicon/PZT thick film vibrational energy harvesters aimed towards vibration sources with peak frequencies in the range of a few hundred Hz. By combining KOH etching with mechanical front side protection, SOI wafer...... to accurately define the thickness of the silicon part of the harvester and a silicon compatible PZT thick film screen-printing technique, we are able to fabricate energy harvesters on wafer scale with a yield higher than 90%. The characterization of the fabricated harvesters is focused towards the full wafer....../mass-production aspect; hence the analysis of uniformity in harvested power and resonant frequency....

  11. Exploring the piezoelectric performance of PZT particulate-epoxy composites loaded in shear

    NARCIS (Netherlands)

    Loock, F.V.; Deutz, D.B.; Zwaag, S.V.D.; Groen, W.A.

    2016-01-01

    The active and passive piezoelectric response of lead zirconium titanate (PZT)-epoxy particulate composites loaded in shear is studied using analytical models, a finite element model and by experiments. The response is compared to that of the same composites when loaded in simple tension. Analogousl

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

    Science.gov (United States)

    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.

  13. Poling process optimization of piezo nano composite PZT/polimer

    Science.gov (United States)

    Ridlo, M. Rosyid; Lestari, Titik; Mardiyanto, Oemry, Achiar

    2013-09-01

    The objective of poling process is to make the electric dipole directions to be parallel in the inside perovskite crystal of piezo materials. In simply way, poling was carried out by giving the two sides of a piezo material by highly electrical potential. More parallel of electrical dipoles, it is more strength the piezo characteristics. The optimization involved control of temperature, time depth and the electrical voltage. The samples was prepared by solgel method with precursor tetrabutyl titanat Ti(OC4H9)4, zirconium nitrat Zr(NO3)4ṡ5H2O, Pb(CH3COO)2ṡ3H2O and solution ethylene glycol. Molar ratio Pb:Zr:Ti = 1,1:0,52:0,48 with concidering lossed Pb. Result of solgel process is nano powder PZT. The formed nano powder PZT was then mixed with polimer PVDF and pressed 10 MPa at 150 °C with the size 15 mm in diameter. After poling, piezoelectric constant d33 was measured. The highest d33 = 45 pC/N was found at poling parameters V = 5 kV/ mm, T = 120 °C dan time depth = 1 hours.

  14. Damping properties of epoxy-based composite embedded with sol–gel-derived Pb(Zr0.53Ti0.47)O3 thin film with different thicknesses

    Indian Academy of Sciences (India)

    Guo Dongyun; Mao Wei; Qin Yan; Huang Zhixiong; Wang Chuanbin; Shen Qiang; Zhang Lianmeng

    2012-06-01

    Pb(Zr0.53Ti0.47)O3 (PZT) thin films were prepared on Pt/Ti/SiO2/Si substrate by sol–gel method. The effect of film thickness on microstructure, ferroelectric and dielectric properties was investigated. The single-phase PZT films were obtained with different thicknesses. PZT films with a thickness of 190–440 nm had better dielectric and ferroelectric properties. The epoxy/PZT film/epoxy sandwiched composites were prepared. The thickness of PZT films influenced their damping properties of the composites, and the epoxy-based composites embedded with 310 nm-thick PZT films had the largest damping loss factor of 0.915.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wegener, Michael; Arlt, Kristin [Functional Polymer Systems, Fraunhofer Institute for Applied Polymer Research (IAP), Geiselbergstrasse 69, 14476 Potsdam-Golm (Germany)], E-mail: michael.wegener@iap.fraunhofer.de

    2008-08-21

    Composite films of lead zirconate titanate (PZT) and poly(vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)) were prepared as 100 {mu}m 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{sup -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.

  16. Dielectric and Piezoelectric Properties of 0-3 PZT/PVDF Composite Doped with Polyaniline

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Lead zirconate titanate (PZT)/polyvinylidenc fluoride (PVDF) 0- 3 piezoelectric composites doped with polyaniline (PANI) were obtained by hot-press method.The polarization properties of the composites were characterized by XRD and P- E hysteresis loops at room temperature.And the dielectric and piezoelectric properties were also measured.The results show that the poling of PZT could be effectively carried out and the dielectric constant εr and dissipation tanδ increase monotonously by increasing the voltme fraction of PANI in the composite.The piezoelectric constant d33, and the planar electromechanical coupling factor kp increase while the mechanical quality factor Qm decreases with the increase in the content of PANI.The d33 , kp and Qm show the extremum valnes at 8 vol%-10 vol% PANI.

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

    Science.gov (United States)

    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.

  18. Enhancing the dielectric property of 0.69PZT-0.31PZNN thick films by optimizing the poling condition

    Science.gov (United States)

    Song, Daniel; Woo, Min Sik; Ahn, Jung Hwan; Sung, Tae Hyun

    2015-05-01

    We investigated how the applied electric-field's magnitude and the poling time affected, respectively, the dielectric property and the microstructure of piezoelectric lead zirconate titanate/lead zirconate nickel niobate (PZT-PZNN) thick films in order to apply the films to piezoelectric energy harvesters. Several 300-µm-thick, 10 × 10-mm2 PZT-PZNN squares were tape cast, laminated, sintered, and poled under 2-, 4-, 6-, 10-, 14-, and 15-kV/mm electric fields for 30 min. The 10-kV/mm electric field produced the highest d 33 × g 33 without mechanically damaging the sample. Further, samples were sintered at 950, 1000, and 1020 °C and subsequently poled at 10 kV/mm (previously determined as the magnitude of the optimal poling electric field) for 15, 30, 60, 120, and 240 min to investigate how the poling time affected the piezoelectric ceramic's microstructure. The optimal poling time for all the sintered samples was 60 min. Further, the piezoelectric ceramics composed of small grains and poled longer than 60 min showed higher dielectric constants. However, those composed of large grains and poled for times shorter than 60 min showed higher dielectric constants because the element mobility of the piezoelectric ceramics increased with increasing poling time.

  19. A nonlinear model for magnetocapacitance effect in PZT-ring/Terfenol-D-strip magnetoelectric composites

    Science.gov (United States)

    Zhang, Juanjuan; Wen, Jianbiao; Gao, Yuanwen

    2016-06-01

    In previous works, most of them employ a linear constitutive model to describe magnetocapacitance (MC) effect in magnetoelectric (ME) composites, which lead to deficiency in their theoretical results. In view of this, based on a nonlinear magnetostrictive constitutive relation and a linear piezoelectric constitutive relation, we establish a nonlinear model for MC effect in PZT-ring/Terfenol-D-strip ME composites. The numerical results in this paper coincide better with experimental data than that of a linear model, thus, it's essential to utilize a nonlinear constitutive model for predicting MC effect in ME composites. Then the influences of external magnetic fields, pre-stresses, frequencies, and geometric sizes on the MC effect are discussed, respectively. The results show that the external magnetic field is responsible for the resonance frequency shift. And the resonance frequency is sensitive to the ratio of outer and inner radius of the PZT ring. Moreover, some other piezoelectric materials are employed in this model and the corresponding MC effects are calculated, and we find that different type of piezoelectric materials affect the MC effect obviously. The proposed model is more accurate for multifunction devices designing.

  20. Mechanical and dielectric characterization of lead zirconate titanate(PZT)/polyurethane(PU) thin film composite for energy harvesting

    Science.gov (United States)

    Aboubakr, S.; Rguiti, M.; Hajjaji, A.; Eddiai, A.; Courtois, C.; d'Astorg, S.

    2014-04-01

    The Lead Zirconate titanate (PZT) ceramic is known by its piezoelectric feature, but also by its stiffness, the use of a composite based on a polyurethane (PU) matrix charged by a piezoelectric material, enable to generate a large deformation of the material, therefore harvesting more energy. This new material will provide a competitive alternative and low cost manufacturing technology of autonomous systems (smart clothes, car seat, boat sail, flag ...). A thin film of the PZT/PU composite was prepared using up to 80 vol. % of ceramic. Due to the dielectric nature of the PZT, inclusions of this one in a PU matrix raises the permittivity of the composite, on other hand this latter seems to decline at high frequencies.

  1. Magnetoelectric Responses of GMM/PZT/GMM Laminate Composite in Longitudinal Vibration%GMM/PZT/GMM层合材料的纵振磁电响应

    Institute of Scientific and Technical Information of China (English)

    文玉梅; 周丽萍; 李平; 卞雷祥

    2009-01-01

    The adhesive layers and the mechanical losses of materials in giant magnetostrictive material (GMM) and piezoelectric Pb(Zr,Ti)O3 (PZT) laminate composites are vital factors to impact final magneto-electric responses. The effects of the adhesive layer resulting from the shear and longitudinal deformation were considered in the governing motion equations of GMM/PZT/GMM composites, which were established based on Hamilton's principle. The coefficients in the motion equations were specified by the material parameters. To introduce the material losses into the analysis, the mechanical parameters including the compliances of magnetostrictive and piezoelectric materials were represented as complexes. Through the motion equations along with the boundary conditions and the constitutive equations of magnetostrictive/piezoelectric effects, the magnetoelectric responses over frequency and the natural frequencies were provided. The numerical calculations of the magnetoelectric responses in GMM/PZT/GMM laminate composite was presented. By comparing the theoretical magnetoelectric response with the experimental result,shows that the introduction of material losses can provide more acceptable prediction of the magnetoelectric performances.%层状复合结构层间胶层和复合材料的机械损耗是影响层状磁电复合材料磁电响应的重要因素.为了考虑层间胶层的作用,包括其纵向变形和剪切变形产生的效果,应用Hamilton原理建立层状复合结构的运动方程,并用复柔顺系数来反映材料的机械损耗特性.结合层状复合结构的边界条件和磁致伸缩/压电本构方程,就可以得到考虑了胶层作用和材料损耗时,复合结构的固有频率和磁电响应.对GMM(超磁致伸缩材料)/PZT(压电材料)/GMM结构的磁电响应进行了数值计算,将计算结果与实验结果进行了比较,证明考虑胶层作用并引入材料的损耗能够更准确预测复合材料的磁电换能特性.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Zeeshan [University Department of Physics, T.M. Bhagalpur University, Bhagalpur 812007 (India); Prasad, Ashutosh, E-mail: apd.phy@gmail.co [University Department of Physics, T.M. Bhagalpur University, Bhagalpur 812007 (India); Prasad, K., E-mail: k.prasad65@gmail.co [University Department of Physics, T.M. Bhagalpur University, Bhagalpur 812007 (India)

    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.

  3. Dynamic modeling and analysis of the PZT-bonded composite Timoshenko beams: Spectral element method

    Science.gov (United States)

    Lee, Usik; Kim, Daehwan; Park, Ilwook

    2013-03-01

    The health of thin laminated composite beams is often monitored using the ultrasonic guided waves excited by wafer-type piezoelectric transducers (PZTs). Thus, for the smart composite beams which consist of a laminated composite base beam and PZT layers, it is very important to develop a very reliable mathematical model and to use a very accurate computational method to predict accurate dynamic characteristics at very high ultrasonic frequency. In this paper, the axial-bending-shear-lateral contraction coupled differential equations of motion are derived first by the Hamilton's principle with Lagrange multipliers. The smart composite beam is represented by a Timoshenko beam model by adopting the first-order shear deformation theory (FSDT) for the laminated composite base beam. The axial deformation of smart composite beam is improved by taking into account the effects of lateral contraction by adopting the concept of Mindlin-Herrmann rod theory. The spectral element model is then formulated by the variation approach from coupled differential equations of motion transformed into the frequency domain via the discrete Fourier transform. The high accuracy of the present spectral element model is verified by comparing with other solution methods: the finite element model developed in this paper and the commercial FEA package ANSYS. Finally the dynamics and wave characteristics of some example smart composite beams are investigated through the numerical studies.

  4. Single dc magnetic field tunable electromechanical resonance in Terfenol-D/PZT/Terfenol-D trilayer composites

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Wang, E-mail: wangwei1@njnu.edu.cn [Opto-Electronic Technology Key Laboratory of Jiangsu Province, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023 (China); JingJing, Ye; Jie, Wu [Opto-Electronic Technology Key Laboratory of Jiangsu Province, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023 (China); LiSheng, Zhou [Hangzhou Applied Acoustics Research Institute, National Key Laboratory of Science and Technology on Sonar, Hang Zhou 310012 (China); Bin, Luo Xiao; Ning, Zhang [Opto-Electronic Technology Key Laboratory of Jiangsu Province, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023 (China)

    2014-10-01

    Single dc magnetic field excited electromechanical resonance (EMR) in Terfenol-D/PZT/Terfenol-D trilayer composites structure was experimentally investigated and theoretically analyzed. The experiment proves dc magnetic field influence on EMR of magnetoelectric (ME) composites. The tuning of approximately 17.7 kHz was obtained in a dc magnetic field of 100 mT. The theory of dc magnetic field tunable resonance frequency shift containing different ferroelectric volume fractions in layer magnetoelectric composites is presented. This tuning is due to the magnetoelectric interactions in the layered ME composites structure. - Highlights: • Magnetically excited EMR in trilayer composites structure was studied. • The EMR frequency shift is approximately 17.7 kHz with dc magnetic field of 100 mT. • Calculation of capacitance as a function of frequency under different magnetic fields. • Dependence of ferroelectric volume fraction on EMR shifts have been revealed. • Promise for control EMR with a dc magnetic field is suggested.

  5. Optimization of a 0.69PZT-0.31PZNN thick film by controlling slurry viscosity and tape-casting blade height

    Science.gov (United States)

    Song, Daniel; Woo, Min Sik; Ahn, Jung Hwan; Sung, Tae Hyun; Kim, Kyoung Bum

    2014-12-01

    We investigated how the viscosities of piezoelectric lead zirconate titanate/lead zirconate nickel niobate (PZT-PZNN) slurry samples affect the laminated-film densities based on various conditions of degassing time for 0, 30, and 60 min. PZT-PZNN slurries with different viscosities were tape casted into green sheets by adjusting the comma blade height to 100, 200, 300, 400, and 500 μm. As a result the slurry viscosity linearly increased with increasing slurry degassing time, and the thickness of the green sheet increased with increasing comma blade height. The density and the dielectric properties of piezoelectric ceramic films with the same thicknesses, but composed of different numbers of layers, were compared. The laminated-film density and the dielectric property d33 × g33 increased with decreasing number of laminated layers. However, when the viscosity of the slurry was too high (degassing time > 60 min) and the comma blade height was too high (comma blade height > 300 μm), the tape-casted green sheet was too thick to have enough time to dry. By controlling the slurry viscosity by adjusting the degassing time and the comma blade height, we were able to optimize the thickness of the green sheet in a tape-casting. The optimal green sheet thickness was < 70 μm, and the number of sheets laminated should be minimized to increase the film's density and dielectric constant.

  6. Optimization of a 0.69PZT-0.31PZNN thick film by controlling slurry viscosity and tape-casting blade height

    Energy Technology Data Exchange (ETDEWEB)

    Song, Daniel; Woo, Minsik; Ahn, Junghwan; Sung, Taehyun [Hanyang University, Seoul (Korea, Republic of); Kim, Kyoungbum [Korea University, Seoul (Korea, Republic of)

    2014-12-15

    We investigated how the viscosities of piezoelectric lead zirconate titanate/lead zirconate nickel niobate (PZT-PZNN) slurry samples affect the laminated-film densities based on various conditions of degassing time for 0, 30, and 60 min. PZT-PZNN slurries with different viscosities were tape casted into green sheets by adjusting the comma blade height to 100, 200, 300, 400, and 500 μm. As a result the slurry viscosity linearly increased with increasing slurry degassing time, and the thickness of the green sheet increased with increasing comma blade height. The density and the dielectric properties of piezoelectric ceramic films with the same thicknesses, but composed of different numbers of layers, were compared. The laminated-film density and the dielectric property d{sub 33} x g{sub 33} increased with decreasing number of laminated layers. However, when the viscosity of the slurry was too high (degassing time > 60 min) and the comma blade height was too high (comma blade height > 300 μm), the tape-casted green sheet was too thick to have enough time to dry. By controlling the slurry viscosity by adjusting the degassing time and the comma blade height, we were able to optimize the thickness of the green sheet in a tape-casting. The optimal green sheet thickness was < 70 μm, and the number of sheets laminated should be minimized to increase the film's density and dielectric constant.

  7. Ferroelectric–Ferromagnetic Composites Based on PZT Type Powder and Ferrite Powder

    OpenAIRE

    Bochenek D.; Niemiec P.; Zachariasz R.; Chrobak A.; Ziółkowski G.

    2013-01-01

    W pracy otrzymano ferroelektryczno-ferromagnetyczne kompozyty na bazie ceramicznego proszku typu PZT. Połączenie ferroelektrycznego i magnetycznego proszku miało na celu otrzymanie materiałów wykazujących zarówno elektryczne i magne- tyczne właściwości. Ferroelektryczny, ceramiczny proszek (w ilości 90%) stanowiły domieszkowane składy proszku typu PZT, natomiast magnetycznym składnikiem w kompozycie był niklówo-cynkowy ferryt (Nii-^Zn^Fe^Oj). Syntetyzowanie składni- ków kompozytu ceramiczno-f...

  8. Flexible PET/Al/PZT/Al/PET multi-layered composite for low frequency energy harvesting

    Science.gov (United States)

    Seveno, R.; Carbajo, J.; Dufay, T.; Guiffard, B.; Thomas, J. C.

    2017-04-01

    A flexible piezoelectric device has been realized by depositing lead zirconate titanate (PZT) thin films by chemical solution deposition (CSD) onto very thin aluminium foil (16 µm) and using a polyethylene terephthalate (PET) laminated film (150 µm) as encapsulation. A ruthenium dioxide layer has been used in order to enhance the quality of the PZT/Al interface, improving the dielectric, ferroelectric and piezoelectric properties of the PZT film. The obtained piezoelectric generators have been subjected to large bending motions at low frequencies ranging from 0.1 to 8 Hz and the experimental values of the output voltage, output current and harvested power have been compared to the theoretical values (derived from the electrokinetic model of the piezoelectric material) with very good agreement. Due to the increase of the permittivity of the PZT film by the use of RuO2 interlayer, a moderate decrease of the harvested power at the optimal load resistance is found (from 185 nW to 143 nW at 4.4 Hz), despite the enhancement of the piezoelectric properties. This type of very flexible film, able to withstand a small radius of curvature (1 cm), may yield a promising avenue in the field of low frequency mechanical energy harvesting.

  9. Effect of sintering temperature and composition on microstructure and properties of PMS-PZT ceramics

    Institute of Scientific and Technical Information of China (English)

    DU Hong-liang; PEI Zhi-bin; LI Zhi-min; LUO Fa; ZHU Dong-mei; ZHOU Wan-cheng; QU Shao-bo

    2006-01-01

    The piezoelectric ceramics xPb(Mn1/3Sb2/3)O3-(1-x)Pb(Zr1/2Ti1/2)O3 (abbreviated as PMS-PZT) were synthesized by traditional ceramics process. The effect of sintering temperature and the amount of Pb(Mn1/3Sb2/3)O3 (abbreviated as PMS) on phase structure,microstructure,piezoelectric and dielectric properties of PMS-PZT ceramics was investigated. The results show that the pure perovskite phase is in all ceramics specimens,the phase structure of PMS-PZT ceramics changes from tetragonal phase to single rhombohedral phase with the increasing amount of PMS. The dielectric constant -r,Curie temperature TC,electromechanical coupling factor kp and piezoelectric constant d33 decrease,whereas the mechanical quality factor Qm and dielectric loss tanδ increase with the increasing amount of PMS in system. The optimum sintering temperature is 1 200-1 250 ℃. It is concluded that the PMS-PZT (x=0.07) ceramics sintered at 1 250 ℃ is suitable for high-power piezoelectric transformer. These properties include -r=674.8,tanδ=0.005 25,kp=0.658,Qm1520,d33=230 pC/N,Tc=275 ℃.

  10. Silver Doped 0.9PMN-PT-0.1PZT Composite Films for very High Frequency Ultrasonic Transducer Applications.

    Science.gov (United States)

    Hsu, Hsiu-Sheng; Benjauthrit, Vatcharee; Wei, Qiang; Huang, Yuhong; Zhou, Qifa; Shung, K Kirk

    2013-05-01

    A series of silver doping concentration into the 0.9PMN-PT-0.1PZT (PMN-PT-PZT) films via the composite sol-gel technique were prepared. The crystallographic properties and microstructures of PMN-PT-PZT films with the silver dopant were investigated. Additionally, the effect of silver doping on dielectric and ferroelectric properties was examined. The results show that in general, the dielectric permittivity and remnant polarization increase as the silver doping concentration is increased. The PMN-PT-PZT+ 2.5 mol% Ag film exhibits a dielectric constant of 3,610 at 1 kHz and a remnant polarization of 57.6 µC/cm(2) at room temperature. From this silver doped film, very high frequency ultrasonic needle transducers were fabricated and evaluated. The representative transducer had the center frequency of 225 MHz with a -6 dB bandwidth of 29% (65 MHz) and 62 dB insertion loss. The performance of this transducer is comparable to other composite sol-gel films transducer. The results suggest that this silver-doped PMN-PT-PZT film is a promising candidate as an alternative piezoelectric film for very high frequency transducer applications.

  11. Silver doped 0.9PMN-PT-0.1PZT composite films for very high frequency ultrasonic transducer applications

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Hsiu-Sheng [University of Southern California, Department of Biomedical Engineering and NIH Transducer Resource Center, Los Angeles, CA (United States); University of Southern California, Mork Family Department of Chemical Engineering and Materials Science, Los Angeles, CA (United States); Benjauthrit, Vatcharee; Zhou, Qifa; Shung, K.K. [University of Southern California, Department of Biomedical Engineering and NIH Transducer Resource Center, Los Angeles, CA (United States); Wei, Qiang; Huang, Yuhong [Chemat Technology Inc., Northridge, CA (United States)

    2013-05-15

    A series of silver doping concentration into the 0.9PMN-PT-0.1PZT (PMN-PT-PZT) films via the composite sol-gel technique were prepared. The crystallographic properties and microstructures of PMN-PT-PZT films with the silver dopant were investigated. Additionally, the effect of silver doping on dielectric and ferroelectric properties was examined. The results show that in general, the dielectric permittivity and remnant polarization increase as the silver doping concentration is increased. The PMN-PT-PZT+2.5 mol% Ag film exhibits a dielectric constant of 3,610 at 1 kHz and a remnant polarization of 57.6 {mu}C/cm{sup 2} at room temperature. From this silver doped film, very high frequency ultrasonic needle transducers were fabricated and evaluated. The representative transducer had the center frequency of 225 MHz with a -6 dB bandwidth of 29 % (65 MHz) and 62 dB insertion loss. The performance of this transducer is comparable to other composite sol-gel films transducer. The results suggest that this silver-doped PMN-PT-PZT film is a promising candidate as an alternative piezoelectric film for very high frequency transducer applications. (orig.)

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

    Science.gov (United States)

    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.

  13. The effect of calcining temperature on the properties of 0-3 piezoelectric composites of PZT and a liquid crystalline thermosetting polymer

    NARCIS (Netherlands)

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

    2011-01-01

    We report on the optimisation of a recently developed high performance 0-3 piezoelectric composite comprising of the piezoelectric Lead Zirconate Titanate (PZT) powder and a liquid crystalline thermosetting matrix polymer (LCT). The matrix polymer is a liquid crystalline polymer comprising of an HBA

  14. Ferroelectric–Ferromagnetic Composites Based on PZT Type Powder and Ferrite Powder

    Directory of Open Access Journals (Sweden)

    Bochenek D.

    2013-12-01

    Full Text Available W pracy otrzymano ferroelektryczno-ferromagnetyczne kompozyty na bazie ceramicznego proszku typu PZT. Połączenie ferroelektrycznego i magnetycznego proszku miało na celu otrzymanie materiałów wykazujących zarówno elektryczne i magne- tyczne właściwości. Ferroelektryczny, ceramiczny proszek (w ilości 90% stanowiły domieszkowane składy proszku typu PZT, natomiast magnetycznym składnikiem w kompozycie był niklówo-cynkowy ferryt (Nii-^Zn^Fe^Oj. Syntetyzowanie składni- ków kompozytu ceramiczno-ferrytowego przeprowadzono metodą spiekania wy prasek w fazie stałej, natomiast zagęszczanie zsyntetyzowanego kompozytowego proszku metodą spiekania swobodnego. Przeprowadzono badania rentgenowskie, mikrostrukturalne. EDS. dielektryczne, magnetyczne, tarcia wewnętrznego oraz elektrycznej pętli hi sterczy. Badania wykazały, występowanie korclacji między podukładem magnetycznym i podukładem elektrycznym w ferroelektryczno-ferromagnetycznych kompozytach. Dzięki ferroelektrycznym i magnetycznym właściwościom otrzymanych kompozytów, materiały tego typu mogą znaleźć zastosowanie aplikacyjne w nowych typach pamięci.

  15. Compressive strength of thick composite panels

    DEFF Research Database (Denmark)

    Branner, Kim; Berring, Peter

    2011-01-01

    The aim of this study is to investigate how much the compressive strength of thick composite panels is reduced due to delaminations and to investigate under which conditions a delamination will grow. Understanding of this is essential in order to move forward the design limits used in the structu......The aim of this study is to investigate how much the compressive strength of thick composite panels is reduced due to delaminations and to investigate under which conditions a delamination will grow. Understanding of this is essential in order to move forward the design limits used...

  16. Properties of quasi 1-3 piezoelectric PZT-epoxy composites obtained by dielectrophoresis

    NARCIS (Netherlands)

    Ende, D.A. van den; Bory, B.F.; Groen, W.A.; Zwaag, S. van der

    2010-01-01

    The dielectric and piezoelectric properties of piezoelectric particleepoxy polymer composites structured into 1-3 composites via dielectrophoresis during curing are reported. The dielectrophoretic alignment induces a textured microstructure in the composite, with particles forming chains in the dire

  17. Active vibration control of a composite wing model using PZT sensors/actuators and virtex: 4 FPGAs

    Science.gov (United States)

    Prakash, Shashikala; Venkatasubramanyam, D. V.; Krishnan, Bharath; Pavate, Aravind; Kabra, Hemant

    2009-07-01

    The reduction of vibration in Aircraft/Aerospace structures as well as helicopter fuselage is becoming increasingly important. A traditional approach to vibration control uses passive techniques which are relatively large, costly and ineffective at low frequencies. Active Vibration Control (AVC), apart from having benefits in size, weight, volume and cost, efficiently attenuates low frequency vibration. Hitherto this was being achieved using high speed Digital Signal Processors (DSPs). But the throughput requirements of general purpose DSPs have increased very much and the Field Programmable Gate Arrays (FPGAs) have emerged as an alternative. The silicon resources of an FPGA lead to staggering performance gains i.e. they are 100 times faster than DSPs. In the present paper Active Vibration Control of a Composite Research Wing Model is investigated using Piezo electric patches as sensors and PZT bimorph actuators collocated on the bottom surface as secondary actuators. Attempt has been made to realize the State - of - the - Art Active Vibration Controller using the Xilinx System Generator on VIRTEX - 4 FPGA. The control has been achieved by implementing the Filtered-X Least Mean Square (FXLMS) based adaptive filter on the FPGA. Single channel real time control has been successfully implemented & tested on the composite research wing model.

  18. Equivalent Circuit Model of Low-Frequency Magnetoelectric Effect in Disk-Type Terfenol-D/PZT Laminate Composites Considering a New Interface Coupling Factor

    Directory of Open Access Journals (Sweden)

    Guofeng Lou

    2017-06-01

    Full Text Available This paper describes the modeling of magnetoelectric (ME effects for disk-type Terfenol-D (Tb0.3Dy0.7Fe1.92/PZT (Pb(Zr,TiO3 laminate composite at low frequency by combining the advantages of the static elastic model and the equivalent circuit model, aiming at providing a guidance for the design and fabrication of the sensors based on magnetoelectric laminate composite. Considering that the strains of the magnetostrictive and piezoelectric layers are not equal in actual operating due to the epoxy resin adhesive bonding condition, the magnetostrictive and piezoelectric layers were first modeled through the equation of motion separately, and then coupled together with a new interface coupling factor kc, which physically reflects the strain transfer between the phases. Furthermore, a theoretical expression containing kc for the transverse ME voltage coefficient αv and the optimum thickness ratio noptim to which the maximum ME voltage coefficient corresponds were derived from the modified equivalent circuit of ME laminate, where the interface coupling factor acted as an ideal transformer. To explore the influence of mechanical load on the interface coupling factor kc, two sets of weights, i.e., 100 g and 500 g, were placed on the top of the ME laminates with the same thickness ratio n in the sample fabrication. A total of 22 T-T mode disk-type ME laminate samples with different configurations were fabricated. The interface coupling factors determined from the measured αv and the DC bias magnetic field Hbias were 0.11 for 500 g pre-mechanical load and 0.08 for 100 g pre-mechanical load. Furthermore, the measured optimum thickness ratios were 0.61 for kc = 0.11 and 0.56 for kc = 0.08. Both the theoretical ME voltage coefficient αv and optimum thickness ratio noptim containing kc agreed well with the measured data, verifying the reasonability and correctness for the introduction of kc in the modified equivalent circuit model.

  19. Equivalent Circuit Model of Low-Frequency Magnetoelectric Effect in Disk-Type Terfenol-D/PZT Laminate Composites Considering a New Interface Coupling Factor.

    Science.gov (United States)

    Lou, Guofeng; Yu, Xinjie; Lu, Shihua

    2017-06-15

    This paper describes the modeling of magnetoelectric (ME) effects for disk-type Terfenol-D (Tb0.3Dy0.7Fe1.92)/PZT (Pb(Zr,Ti)O₃) laminate composite at low frequency by combining the advantages of the static elastic model and the equivalent circuit model, aiming at providing a guidance for the design and fabrication of the sensors based on magnetoelectric laminate composite. Considering that the strains of the magnetostrictive and piezoelectric layers are not equal in actual operating due to the epoxy resin adhesive bonding condition, the magnetostrictive and piezoelectric layers were first modeled through the equation of motion separately, and then coupled together with a new interface coupling factor kc, which physically reflects the strain transfer between the phases. Furthermore, a theoretical expression containing kc for the transverse ME voltage coefficient αv and the optimum thickness ratio noptim to which the maximum ME voltage coefficient corresponds were derived from the modified equivalent circuit of ME laminate, where the interface coupling factor acted as an ideal transformer. To explore the influence of mechanical load on the interface coupling factor kc, two sets of weights, i.e., 100 g and 500 g, were placed on the top of the ME laminates with the same thickness ratio n in the sample fabrication. A total of 22 T-T mode disk-type ME laminate samples with different configurations were fabricated. The interface coupling factors determined from the measured αv and the DC bias magnetic field Hbias were 0.11 for 500 g pre-mechanical load and 0.08 for 100 g pre-mechanical load. Furthermore, the measured optimum thickness ratios were 0.61 for kc = 0.11 and 0.56 for kc = 0.08. Both the theoretical ME voltage coefficient αv and optimum thickness ratio noptim containing kc agreed well with the measured data, verifying the reasonability and correctness for the introduction of kc in the modified equivalent circuit model.

  20. Preparation and Characterization of PZT Wafers

    Science.gov (United States)

    Seal, A.; Rao, B. S. S. Chandra; Kamath, S. V.; Sen, A.; Maiti, H. S.

    2008-07-01

    Piezoelectric materials have recently attracted a lot of attention for ultrasonic structural health monitoring (shm) in aerospace, defence and civilian sectors, where they can act as both actuators and sensors. Incidentally, piezoelectric materials in the form of wafers (pwas-piezoelectric wafer active sensor, approx. 5-10 mm square and 0.2-0.3 mm thickness) are inexpensive, non intrusive and non-resonant wide band devices that can be surface-mounted on existing structures, inserted between the layers of lap joints or embedded inside composite materials. The material of choice for piezoelectric wafers is lead zirconate titanate (PZT) of composition close to morphotropic phase boundary [pb(zr0.52 ti0.48)o3]. However, an excess pbo is normally added to pzt as a densification aid and also to make up for the lead loss during high temperature sintering. Hence, it is of paramount importance to know how the shift of the lead content from the morphotropic composition affects the piezoelectric and mechanical properties of the sintered wafers, keeping in view the importance of mechanical properties of wafers in shm. In the present study, we observed that with the increase in the lead content of the sintered wafers, the dielectric and piezoelectric constants decreased. However, the elastic modulus, hardness and fracture toughness of the wafers increased with increasing lead content in the composition. Hence, the lead content in the sintered wafers should be optimized to get acceptable piezoelectric and mechanical

  1. Damage detection in composite materials using PZT actuators and sensors for structural health monitoring

    Science.gov (United States)

    Spiegel, Michelle DuBose

    Structural Health Monitoring (SHM) of bridges, buildings, aircrafts, and spacecraft using a network of sensors has gained popularity over recent years. In this thesis, the use of piezoelectric actuators and sensors is described for detecting damage in a composite panel. The composite panels are fabricated using the Vacuum Assisted Resin Transfer Molding (VARTM) process. The panels are cut into small coupons (254 mm x 25.4 mm) to test various properties of the composite. A piezoelectric actuator is surface mounted on the composite coupon to generate Lamb waves while a surface mounted piezoelectric sensor measures the response. Data is collected from an undamaged composite coupon, and then the process is repeated for a damaged coupon. The existing damage is quantified by comparing the response of the damaged and undamaged composite coupons.

  2. In situ Barely Visible Impact Damage detection and localization for composite structures using surface mounted and embedded PZT transducers: A comparative study

    Science.gov (United States)

    Dziendzikowski, M.; Kurnyta, A.; Dragan, K.; Klysz, S.; Leski, A.

    2016-10-01

    Application of guided waves excited by a network of PZT transducers integrated with a given structure is one of the promising approaches to Structural Health Monitoring (SHM). The performance of a SHM system based on PZT network is rooted in two distinct areas of the technology development, that is the hardware and the signal analysis. The first includes the type of transducers used to built a network and the way of their integration with a monitored structure. For composites, besides the possibility of the transducers attachment to a surface of an element, also embedding of PZTs into their internal structure is available. In the article Barely Visible Impact Damage (BVID) detection capabilities as well as selected physical properties of the embedded and surface mounted PZT transducers are compared in broad frequency range of the excitation. Among the compared parameters are the impedance and capacitance spectra up to 600 kHz. The damage detection capabilities are compared in the range 100-350 kHz. In addition to purely qualitative detection of damages a new algorithm of their localization is proposed and compared between the embedded and surface attached transducers for the frequency optimal to detect BVIDs.

  3. 柔性PZT复合材料的热释电性质研究%INVESTIGATION OF THE PYROELECTRIE PROPERTIES OF THE FLEXIBLE PZT COMPOSITE

    Institute of Scientific and Technical Information of China (English)

    王国欣

    2001-01-01

    The pyroelectric properties of a flexble composite composed ofNb-doped PZT grains and silica gel are reported.Compared with compact piezoelectric its pyroelectric coefficient is 0.2×10-8~0.28×10-8 C/(cm2·℃),while that of pyroelectric PZT ceramic is 4.9×10-8C/(cm2·℃);the pyroeletric response of the flexible composite is about 5 times greater,than that of the compact ceramic.A method of calculating the pyroelectric coefficient and response of these materials is also described.%研究了由掺铌的钛锆酸铅颗粒与硅橡胶混合物的热释电性质;与一般的致密压电陶瓷相比较,其热释电系数为0.6×10-8~2.0×10-8C/(cm2·℃),而致密PZT陶瓷的热释电系数为4.9×10-8C/(cm2·℃),柔性复合物的热释电响应大约比致密陶瓷大5倍;描述了一种计算这些材料热释电系数和热释电响应的方法.

  4. In situ X-ray diffraction studies on the piezoelectric response of PZT thin films

    Energy Technology Data Exchange (ETDEWEB)

    Davydok, A., E-mail: davydok@mpie.de [Aix Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334, 13397 Marseille (France); Max-Planck-Institut für Eisenforschung, Department Structure and Nano-/Micromechanics of Materials, D-40237 Düsseldorf (Germany); Cornelius, T.W. [Aix Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334, 13397 Marseille (France); Mocuta, C. [SOLEIL Synchrotron, DiffAbs beamline, L' Orme des Merisiers, Saint-Aubin - BP 48, 91192 Gif-sur-Yvette Cedex (France); Lima, E.C. [Universidade Federal do Tocantins, 77500-000 Porto Nacional, TO (Brazil); Araujo, E.B. [Departamento de Fisica e Quimica, Universidade Estadual Paulista, Av. Brasil, 56 Centro, 15385-000 Ilha Solteira, SP (Brazil); Thomas, O. [Aix Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334, 13397 Marseille (France)

    2016-03-31

    Piezoelectric properties of randomly oriented self-polarized PbZr{sub 0.50}Ti{sub 0.50}O{sub 3} (PZT) thin films were investigated using in situ synchrotron X-ray diffraction. Possibilities for investigating the piezoelectric effect using micro-sized hard X-ray beams are demonstrated and perspectives for future dynamical measurements on PZT samples with variety of compositions and thicknesses are given. Studies performed on the crystalline [100, 110] directions evidenced piezoelectric anisotropy. The piezoelectric coefficient d{sub 33} was calculated in terms of the lab reference frame (d{sub perp}) and found to be two times larger along the [100] direction than along the [110] direction. The absolute values for the d{sub perp} amount to 120 and 230 pm/V being in good agreement with experimental and theoretical values found in literature for bulk PZT ceramics. - Highlights: • We performed in situ synchrotron X-ray diffraction studies on (PZT) thin films. • We discuss anisotropy of piezo effect in different crystallographic directions. • Perpendicular component Piezo coefficient of thin PZT layer is defined.

  5. Design, Modeling and Optimization of a Piezoelectric Pressure Sensor based on a Thin-Film PZT Membrane Containing Nanocrystalline Powders

    Directory of Open Access Journals (Sweden)

    Vahid MOHAMMADI

    2009-11-01

    Full Text Available In this paper fabrication of a 0-3 ceramic/ceramic composite lead zirconate titanate, Pb(Zr0.52Ti0.48O3 thin film has been presented and then a pressure sensor based on multilayer thin-film PZT diaphragm contain of Lead Zirconate Titanate nanocrystalline powders was designed, modeled and optimized. Dynamics characteristics of this multilayer diaphragm have been investigated by ANSYS® FE software. By this simulation the effective parameters of the multilayer PZT diaphragm for improving the performance of a pressure sensor in different ranges of pressure are optimized. The optimized thickness ratio of PZT layer to SiO2 was given in the paper to obtain the maximum deflection of the multilayer thin-film PZT diaphragm. A 0-3 ceramic/ceramic composite lead zirconate titanate, Pb(Zr0.52Ti0.48O3 film has been developed to fabricate the pressure sensor by a hybrid sol gel process. PZT nanopowders fabricated via conventional sol gel method and uniformly dispersed in PZT precursor solution by an attrition mill. XRD analysis shows that perovskite structure would be formed due to the presence of a significant amount of ceramic nanopowders. This texture has a good effect on piezoelectric properties of perovskite structure. The film forms a strongly bonded network and less shrinkage occurs, so the films do not crack during process. Also the aspect ratio through this process would be increased. SEM micrographs indicated that PZT films were uniform, crack free and have a composite microstructure and a piezoelectric coefficient d31 of -40 pC.N-1 and d33 ranged from 50pm.N-1 to 60pm.N-1.

  6. Fabrication, characterization and applications of PZT and ITO nanostructures

    Science.gov (United States)

    Xu, Shiyou

    Lead Zirconate Titanate (PbZr1--xTixO 3, PZT) is one of the most important piezoelectric materials, which has been used traditionally as sensors and actuators. One dimensional (1-D) PZT is expected to have great potentials as building blocks for micro and nano sensors and actuators, nano active fiber composites and integrated nanosystems. The objective of this research is to investigate the size effect on mechanical and piezoelectric properties through the fabrication and characterization of 1-D PZT nanostructures such as PZT nanofibers and nanotubes. The electrospinning process and template-assisted method were used to synthesize PZT nanofibers and nanotubes, respectively. Various novel experimental methods, such as atomic force microscopy (AFM) and nanomanipulator, were used to characterize the mechanical and piezoelectric properties of PZT nanostructures. The obtained results have shown that the piezoelectric and mechanical properties of PZT are size dependent. A single PZT nanofiber presented a lower young's modulus (42.99 GPa measured from AFM-base method and 46.6 GPa from vibration-based method, respectively) than that of PZT thin films and bulks. The PZT nanofibers with diameters smaller than 150 nm still demonstrated a strong electromechanical coupling effect. The piezoelectric constant (d 33) of PZT nanofibers increased from 574.1 pm/V to 860.5 pm/V when their diameters decreased from 112 nm to 50 nm. PZT nanotubes were found to have a d33 value of up to 595 pm/V. These values are significantly higher than that of PZT thin films and comparable to that of PZT bulks. The PZT nanofibers and nanotubes developed in this research not only provide new types of sensing and actuation mechanisms for various novel nanodevices, but also provide significantly improved performance compared with their thin film counterpart used in microelectromechanical systems (MEMS). 1-D ITO nanostructures (nanofibers and nanotubes) were synthesized and characterized for potential use

  7. Comparison of the thermal degradation of heavily Nb-doped and normal PZT thin films.

    Science.gov (United States)

    Yang, Jeong-Suong; Kang, Yunsung; Kang, Inyoung; Lim, Seungmo; Shin, Seung-Joo; Lee, Jungwon; Hur, Kangheon

    2017-01-04

    The degradation of Niobium-doped lead zirconate titanate (PZT) and two types of PZT thin films were investigated. Undoped PZT, 2-step PZT and heavily Nb-doped PZT (PNZT) around the morphotropic phase boundary (MPB) were in-situ deposited under optimum condition by RF-magnetron sputtering. All 2 μm thick films had dense perovskite columnar grain structure and self-polarized (100) dominant orientation. PZT thin films were deposited on Pt/TiOx bottom electrode on Si wafer, and Nb doped PZT thin film was on Ir/TiW electrode with help of orientation control. Sputtered PZT films formed on MEMS gyroscope, and the degradation rates were compared at different temperatures. Nb-doped PZT showed the best resistance to the thermal degradation, followed by 2-step PZT. To clarify the effect of oxygen vacancies for the degradation of the film at high temperature, photo-luminescence (PL) measurement was conducted. It confirmed that oxygen vacancy rate was the lowest in heavily Nb-doped PZT. Nb-doping PZT thin films suppressed the oxygen deficit and made high imprint with self-polarization. This defect distribution and high internal field allowed Nb-doped PZT thin film to make the piezoelectric sensors more stable and reliable at high temperature, such as reflow process of micro-electromechanical system (MEMS) packaging.

  8. Influence of binding material of PZT coating on microresonator's electrical and mechanical properties

    Science.gov (United States)

    Janusas, Giedrius; Guobiene, Asta; Palevicius, Arvydas; Brunius, Alfredas; Cekas, Elingas; Baltrusaitis, Valentinas; Sakalys, Rokas

    2017-06-01

    Microresonators are fundamental components integrated in hosts of MEMS applications: covering the automotive sector, the telecommunication industry, electronic equipment for surface/material characterization and motion sensing, and etc. The aim of this paper is to investigate the mechanical and electrical properties of PZT film fabricated with three binding materials: polyvinyl butyral (PVB), polymethyl methacrylate (PMMA) and polystyrene (PS) and to evaluate applicability in control of microresonators Q factor. Micro particles of PZT powder were mixed with 20% solution of PVB, PMMA and PS in benzyl alcohol. For investigation of mechanical and electrical properties multilayer cantilevers were made. Obtained PZT and polymer paste was screen printed on copper (thickness 40 μm) using polyester monofilament screen meshes (layer thickness 50 μm) and dried for 30 min at 100°C. Electric dipoles of the PZT particles in composite material were aligned using high voltage generator (5 kV) and a custom-made holder. Electric field was held for 30 min. Surfaces of the applied films were investigated by Atomic Force Microscope NanoWizard(R)3 NanoScience. Dynamic and electrical characteristics of the multilayer were investigated using laser triangular displacement sensor LK-G3000. The measured vibration amplitude and generated electrical potential was collected with USB oscilloscope PicoScope 3424. As the results showed, these cantilevers were able to transform mechanical strain energy into electric potential and, v.v. However, roughness of PZT coatings with PMMA and PS were higher, what could be the reason of the worse quality of the top electrode. However, the main advantage of the created composite piezoelectric material is the possibility to apply it on any uniform or non-uniform vibrating surface and to transform low frequency vibrations into electricity.

  9. Study on Inter-Diffusion Barrier Layer between PZT Pyroelectric Thick Film and Si Substrate%PZT厚膜与Si衬底互扩散阻挡层研究

    Institute of Scientific and Technical Information of China (English)

    陈冲; 吴传贵; 彭强祥; 罗文博; 张万里; 王书安

    2013-01-01

    在Pt/Ti/SiO2/Si基片上,利用电泳沉积制备PZT热释电厚膜材料.为防止Pb和Si互扩散,在Pt底电极与SiO2/Si衬底间通过直流磁控溅射制备了TiOx薄膜阻挡层.对具有0、300 nm和500 nm TiOx阻挡层的PZT厚膜材料用SEM和能量色散谱仪(EDS)表征了Pb和Si互扩散情况,用动态热释电系数测量仪测试了热释电系数.结果表明,当TiOx阻挡层为500 nm时,可阻挡Pb和Si互扩散,热释电性能最好.热释电系数p=1.5×10-8 C·cm-2·K-1,相对介电常数εr=170,损耗角正切tanδ=0.02,探测度优值因子Fd=1.05×10-5pa-0.5.%PZT thick film as pyroelectric material has been prepared on the Pt/Ti/SiCK/Si substrate by using the electrophoresis deposition (EPD) method. In order to prevent the inter-diffusion between Pb and Si,a TiOx film barrier layer between Pt bottom electrode and SiO2/Si substrate has been prepared by using the DC magnetron sputtering method. The inter-diffusion between Pb and Si in PZT thick film material with TiO, barrier layer thickness of 0, 300 nm and 500 nm respectively have been characterized by SEM and EDS. The pyroelectric coefficient has been measured by the dynamic pyroelectric coefficient instrument. The results show that the inter-diffusion between Pb and Si can be blocked when the thickness of TiOx barrier layer is 500 nm and have the best pyroelectric properties. The pyroelectric coefficient, relative dielectric constant,dielectric loss and detectivity figure of merit are p=1. 5 × 10-8C · cm-2k-1 ,εr = 170,tan 8=0. 02 and Fd = 1. 05 × 10-5 Pa-0.5 respectively.

  10. Effect of thickness of bonded composite resin on compressive strength

    NARCIS (Netherlands)

    Hamburger, J.T.; Opdam, N.J.; Bronkhorst, E.M.; Roeters, J.; Huysmans, M.C.

    2014-01-01

    OBJECTIVE: The aim of this study was to investigate the compressive strength of composites with different physical properties bonded as a restoration to dentin in layers of varying thicknesses. METHODS: Four types of direct composite materials: a midway-filled (Tetric EvoCeram); a compact-filled (Cl

  11. Determination of body composition from skinfold thickness: a validation study.

    OpenAIRE

    Reilly, J J; Wilson, J.; Durnin, J V

    1995-01-01

    Measurement of body composition is proving increasingly important in clinical nutrition and research. Skinfold thickness is a simple means of estimating body composition which is widely used in children, but there is little information on its validity. There has been a proliferation of equations for estimation of body composition from skinfolds, but some doubt as to their general applicability. The aim of the present study was to validate five currently used equations for this purpose in a sa...

  12. Thick-walled carbon composite multifunctional structures

    Science.gov (United States)

    Haake, John M.; Jacobs, Jack H.; McIlroy, Bruce E.

    1997-06-01

    Satellite programs are moving in the direction of smaller and lighter structures. Technological advances have permitted more sophisticated equipment to be consolidated into compact spaces. Micro-satellites, between 10 and 100 kg, will incorporate micro-electric devices into the lay-up of the satellite structure. These structures will be designed to carry load, provide thermal control, enhance damping, and include integrated passive electronics. These multifunctional structures offer lighter weight, reduced volume, and a 'smarter' overall package for incorporation of sensors, electronics, fiber optics, powered appendages or active components. McDonnell Douglas Corporation (MDC) has applied technology from the synthesis and processing of intelligent cost effective structures (SPICES) and independent research and development (IRAD) programs to the modular instrument support system (MISS) for multifunctional space structures and micro-satellites. The SPICES program was funded by the Defense Advanced Research Projects Agency (DARPA) to develop affordable manufacturing processes for smart materials to be used in vibration control, and the MISS program was funded by NASA-Langley. The MISS program was conceived to develop concepts and techniques to make connections between different multifunctional structures. MDA fabricated a trapezoidal carbon composite structure out of IM7/977-3 tape prepreg. Flex circuits, thermal and optical conduits were embedded to realize a utility modular connector. These provide electrical, thermal, optical and mechanical connections between micro- satellite components. A quick disconnect mount was also developed to accommodate a variety of devices such as solar arrays, power sources, thermal transfer and vibration control modules.

  13. Pyroelectric Charge Release in Rhombohedral PZT

    NARCIS (Netherlands)

    Noheda, Beatriz; Duan, Ning; Cereceda, Noé; Gonzalo, Julio A.

    1998-01-01

    A new experimental set-up controlled by computer has been made to measure the pyroelectric charge of ferroelectric materials with a relatively high conductivity at slow rates of temperature variation. It allowed us to obtain the polarisation vs. temperature behaviour of PZT with various compositions

  14. Thickness filters for gradient based multi-material and thickness optimization of laminated composite structures

    DEFF Research Database (Denmark)

    Sørensen, Rene; Lund, Erik

    2015-01-01

    This paper presents a new gradient based method for performing discrete material and thickness optimization of laminated composite structures. The novelty in the new method lies in the application of so-called casting constraints, or thickness filters in this context, to control the thickness...... govern the presence of material in each layer through the thickness of the laminate. Combined with an in-plane density filter, the method enables manufacturers to control the length scale of the geometry while obtaining near discrete designs. Together with the applied manufacturing constraints it is now...... possible for manufacturers to steer the design towards a higher level of manufacturability. The method is demonstrated for mass minimization with displacement and manufacturing constraints. The results show that the method indeed is capable of obtaining near discrete designs which obey the governing...

  15. Magnetoelectric effect in metal–PZT laminates

    Indian Academy of Sciences (India)

    S Narendra Babu; T Bhimasankaram; S V Suryanarayana

    2005-08-01

    Magnetoelectric (ME) composites are two-phase composites consisting of piezoelectric and piezomagnetic materials as the participating constituents. These magnetoelectric composites when placed under external magnetic field, show electrical polarization (magnetoelectric output). The ME coupling is mediated by mechanical stress. In the present study, we have synthesized Ni/PZT/Ni and Fe/PZT/Fe layered composites for studying their ME output by dynamic magnetoelectric set up in which both d.c. and a.c. magnetic fields can be varied. The ME output obtained in these composites are higher than those obtained in 40% Ni0.97Co0.03Mn0.01 Fe1.9O4 + 60% BaTi1.02O3.04. The results with varying d.c. and a.c. magnetic fields are presented.

  16. Dielectric and magnetic properties of 0.4PZT+0.6NiCuZn-ferrite composites modified with P2O5-Co2O3

    Science.gov (United States)

    Jia, Lijun; Zhang, Huaiwu; Li, Tao; Liu, Yingli; Wen, Qiye; Shen, Jian

    2010-05-01

    P2O5 and Co2O3 have been introduced to 0.4PZT+0.6NiCuZn-ferrite composites in order to improve their electromagnetic properties, particularly for the suppression of electromagnetic interference. The nonlinear fitting of the results of permeability dispersion has revealed the relationships between domain wall resonance, spin rotation relaxation mechanisms, microstructure, and local induced anisotropy. The P2O5 additive can enhance the bulk density and static permeability due to its instantaneous liquid phase at low temperature. The existence of local induced anisotropy caused by ordering of Co ions results in a decrease in static permeability and an increase in the Q-factor. Meanwhile, the addition of Co2O3 can improve the dielectric constant and the loss tangent (tan δe) by increasing the oxygen vacancy concentration. The further decrease in tan δe of the samples codoped with P2O5 and Co2O3 is mainly attributed to P5+ in the grain boundary which can increase cation vacancies in the grain boundary region.

  17. Residual Strains in Thick Thermoplastic Composites: an Experimental Approach

    NARCIS (Netherlands)

    Parlevliet, P.P.

    2010-01-01

    Thermoplastic composites are currently investigated for application in windmill turbine blades for their recyclability. A suitable manufacturing technology for these thick structures is liquid resin infusion followed by in-situ polymerisation of Anionic Polyamide-6 (APA-6). During manufacturing of t

  18. Wave attenuation in thick graphite/epoxy composites

    Science.gov (United States)

    Mal, A. K.; Bar-Cohen, Y.

    1992-01-01

    The mechanics of wave attenuation in thick graphite/epoxy composites is examined in order to facilitate interpretation of the wave amplitudes recorded in ultrasonic experiments. The values of a small number of parameters are determined through comparison between calculated and measured waveforms for four specimens. The agreement between the measured and calculated waveforms are shown to be excellent in all four cases.

  19. Changes in thickness of magnetized composites due to current flow

    Science.gov (United States)

    Bednarek, S.

    1998-02-01

    The pinch magnitude in monolithic metal conductors and ferromagnetics was estimated in this paper. The conditions for the material were formulated so that the pinch which occurs in it could reach the magnitude useful for applications. The way of production of a special composite with a laminar structure was described. The composite consists of sheets of copper foil separating the layers of the elastic ferromagnet which was made by the dispersion of hard magnetic particles in silicon. Using a measuring system containing a Michelson interferometer, measurements of changes were made in the thickness of the produced composite samples during the electric current flow. The obtained results were discussed.

  20. Lamb wave dispersion in a PZT/metal/PZT sandwich plate with imperfect interface

    Science.gov (United States)

    Kurt, Ilkay; Akbarov, Surkay D.; Sezer, Semih

    2016-07-01

    The Lamb wave dispersion in a PZT/Metal/PZT sandwich plate is investigated by employing the exact linear equations of electro-elastic waves in piezoelectric materials within the scope of the plane-strain state. It is assumed that at the interfaces between the piezoelectric face layers and metal core layer, shear-spring and normal-spring type imperfect conditions are satisfied. The degree of this imperfectness is estimated through the corresponding shear-spring and normal-spring type parameters which appear in the contact condition characterizing the transverse and normal displacements' discontinuity. The corresponding dispersion equation is derived, and as a result of the numerical solution to this equation, the dispersion curves are constructed for the first and second lowest modes in the cases where the material of the face layers is PZT and the material of the middle layer is Steel (St). Consequently, for the PZT/St/PZT sandwich plate, the study of the influence of the problem parameters such as the piezoelectric and dielectric constants, layer thickness ratios, non-dimensional shear-spring, and normal-spring type parameters, is carried out. In particular, it is established that the imperfectness of the contact between the layers of the plate causes a decrease in the values of the wave propagation velocity.

  1. Effect of thickness on the stress and magnetoelectric coupling in bilayered Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3}-CoFe{sub 2}O{sub 4} films

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jing, E-mail: wang-jing@nuaa.edu.cn, E-mail: cwnan@tsinghua.edu.cn [State Key Laboratory of Mechanics and Control of Mechanical Structures, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Li, Zheng; Wang, Jianjun; Nan, Cewen, E-mail: wang-jing@nuaa.edu.cn, E-mail: cwnan@tsinghua.edu.cn [School of Materials Science and Engineering, State Key Lab of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084 (China); He, Hongcai [State Key Lab of Electronic Thin Films and Integrated Devices, School of Microelectronics and Solid-State Electronics, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China)

    2015-01-28

    Magnetoelectric bilayered Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3}-CoFe{sub 2}O{sub 4}(PZT-CFO) films with different PZT thicknesses were grown on (111)Pt/Ti/SiO{sub 2}/Si substrates using chemical solution spin-coating. Structural characterization by X-ray diffraction and electron microscopy shows pure phases and well-defined interfaces between the PZT and CFO films. The CFO-PZT-substrate structure effectively alleviates the substrate clamping effect for the CFO layer, showing appreciable magnetoelectric responses in the composite films. Both the direct magnetoelectric effect and the magnetic field-induced Raman shifts in the A{sub 1}(TO{sub 1}) soft mode of PZT demonstrate the magnetic-mechanical-electric coupling in the films. The results also indicate that with a constant CFO layer thickness, the thickness of the PZT layer plays an important role in the stress relaxation and strong magnetoelectric coupling. The coupling could be further enhanced by increasing the CFO thickness, optimizing the volume (thickness) fraction of the PZT thickness, and releasing the clamping effect from the substrate.

  2. Active PZT fibers: a commercial production process

    Science.gov (United States)

    Strock, Harold B.; Pascucci, Marina R.; Parish, Mark V.; Bent, Aaron A.; Shrout, Thomas R.

    1999-07-01

    Lead Zirconate Titanate (PZT) active fibers, from 80 to 250 micrometers in diameter, are produced for the AFOSR/DARPA funded Active Fiber Composites Consortium (AFCC) Program and commercial customers. CeraNova has developed a proprietary ceramics-based technology to produce PZT mono-filaments of the required purity, composition, straightness, and piezoelectric properties for use in active fiber composite structures. CeraNova's process begins with the extrusion of continuous lengths of mono-filament precursor fiber from a plasticized mix of PZT-5A powder. The care that must be taken to avoid mix contamination is described using illustrations form problems experiences with extruder wear and metallic contamination. Corrective actions are described and example microstructures are shown. The consequences of inadequate lead control are also shown. Sintered mono- filament mechanical strength and piezoelectric properties data approach bulk values but the validity of such a benchmark is questioned based on variable correlation with composite performance measures. Comb-like ceramic preform structures are shown that are being developed to minimize process and handling costs while maintaining the required mono-filament straightness necessary for composite fabrication. Lastly, actuation performance data are presented for composite structures fabricated and tested by Continuum Control Corporation. Free strain actuation in excess of 2000 microstrain are observed.

  3. Analytical modeling of demagnetizing effect in magnetoelectric ferrite/PZT/ferrite trilayers taking into account a mechanical coupling

    Science.gov (United States)

    Loyau, V.; Aubert, A.; LoBue, M.; Mazaleyrat, F.

    2017-03-01

    In this paper, we investigate the demagnetizing effect in ferrite/PZT/ferrite magnetoelectric (ME) trilayer composites consisting of commercial PZT discs bonded by epoxy layers to Ni-Co-Zn ferrite discs made by a reactive Spark Plasma Sintering (SPS) technique. ME voltage coefficients (transversal mode) were measured on ferrite/PZT/ferrite trilayer ME samples with different thicknesses or phase volume ratio in order to highlight the influence of the magnetic field penetration governed by these geometrical parameters. Experimental ME coefficients and voltages were compared to analytical calculations using a quasi-static model. Theoretical demagnetizing factors of two magnetic discs that interact together in parallel magnetic structures were derived from an analytical calculation based on a superposition method. These factors were introduced in ME voltage calculations which take account of the demagnetizing effect. To fit the experimental results, a mechanical coupling factor was also introduced in the theoretical formula. This reflects the differential strain that exists in the ferrite and PZT layers due to shear effects near the edge of the ME samples and within the bonding epoxy layers. From this study, an optimization in magnitude of the ME voltage is obtained. Lastly, an analytical calculation of demagnetizing effect was conducted for layered ME composites containing higher numbers of alternated layers (n ≥ 5). The advantage of such a structure is then discussed.

  4. Influence of La in xPBBiN of ternary nanoceramic composite (1-x0.5PMN-0.5PZT-xPBBiN system by mechanic al activatio n technique for dielectric and piezoelectric properties

    Directory of Open Access Journals (Sweden)

    K. CHANDRAMOULI

    2011-06-01

    Full Text Available (1-x[0.5Pb(Mg0.33Nb0.67O3-0.5Pb(Zr0.53Ti0.47O3]-x[Pb0.557Ba0.38La0.022Bi0.02Nb2O6] with both perovskite and tungsten bronze structured composite have been synthesized through mechanical activation technique. The strong influence of lanthanum addition to the lead-barium-bismuth-niobate (xPBLBiN ceramics in perovskite structured (1-xPMN-PZT on structural and functional properties is confirmed. X-ray diffraction patterns studies showed that these complex composites consisted of perovskite Cubic with tungsten bronze Orthorhombic phases. La modification in PBBiN of a ternary system (1-xPMN-PZTxPBBiN revealed intensified orthorhombicity. As La increased the dielectric and piezoelectric properties tremendously increased in (1-xPMN-PZT-xPBLBiN nanoceramic composite. The optimum dielectric and piezoelectric properties (εRT = 2931, kp = 0.461 and d33 = 428 pC/N were found in x =0.4 composite. We achieved novel nanocomposites synthesized by high energy ball milling method and having binary structures in a single composite with excellent functional properties that can be used for energy harvesting applications.

  5. Local piezoelectric behavior in PZT-based thin films for ultrasound transducers

    Science.gov (United States)

    Griggio, Flavio

    Piezoelectric microelectromechanical systems (MEMS) are currently used in inkjet printers and precision resonators; numerous additional applications are being investigated for sensors, low-voltage actuators, and transducers. This work was aimed at improving piezoelectric MEMS by taking two approaches: 1) identifying factors affecting the piezoelectric response of ferroelectric thin films and 2) demonstrating integration of these films into a high frequency array transducer. It was found that there are several key factors influencing the piezoelectric response of thin films for a given material composition. First, large grain size improves the piezoelectric response. This was demonstrated using chemical solution deposited lead nickel niobate -- lead zirconate titanate (0.3)Pb(Ni 0.33Nb0.67)O3 - (0.7)Pb(Zr0.45Ti 0.55O3), (PNN-PZT) ferroelectric thin films. It was shown that this composition allows greater microstructural control than does PZT. Dielectric permittivities ranging from 1350 to 1520 and a transverse piezoelectric coefficient e31,f as high as -- 9.7 C/m 2 were observed for films of about 0.25 mum in thickness. The permittivity and piezoelectric response as well as extrinsic contributions to the dielectric constant increased by 14 and 12 % respectively for samples with grain sizes ranging from 110 to 270 nm. A second factor influencing the piezoelectric response is film composition with respect to the morphotropic phase boundary (MPB). The composition dependence of the dielectric and piezoelectric nonlinearities was characterized in epitaxially grown (0.3)Pb(Ni0.33Nb0.67)O3-(0.7)Pb(Zr xTi1-xO3) thin films deposited on SrTiO 3 to minimize the influence of large-angle grain boundaries. Tetragonal, MPB and rhombohedral films were prepared by changing the Zr/Ti ratio. The largest dielectric and piezoelectric nonlinearities were observed for the rhombohedral sample; this resulted from a higher domain wall mobility due to a smaller ferroelectric distortion and

  6. Compatibility of RuO2 electrodes with PZT ceramics

    Indian Academy of Sciences (India)

    K T Jacob; G Rajitha; V S Saji

    2009-06-01

    Because of its high electrical conductivity and good diffusion barrier properties ruthenium dioxide (RuO2) is a good electrode material for use with ferroelectric lead zirconate–titanate (PZT) solid solutions. Under certain conditions, RuO2 can react with PZT to form lead ruthenate (Pb2Ru2O6.5) during processing at elevated temperatures resulting in lead depletion from PZT. The standard Gibbs energies of formation of RuO2 and Pb2Ru2O6.5 and activities of components of the PZT solid solution have been determined recently. Using this data along with older thermodynamic information on PbZrO3 and PbTiO3, the stability domain of Pb2Ru2O6.5 is computed as a function of PZT composition, temperature and oxygen partial pressure in the gas phase. The results show PbZrO3-rich compositions are more prone to react with RuO2 at all temperatures. Increasing temperature and decreasing oxygen partial pressure suppress the reaction. Graphically displayed are the reaction zones as a function of oxygen partial pressure and PZT composition at temperatures 973, 1173 and 1373 K.

  7. Effect of preheating on the film thickness of contemporary composite restorative materials

    Directory of Open Access Journals (Sweden)

    Dimitrios Dionysopoulos

    2014-12-01

    Conclusion: The film thickness of the composites tested is material dependent. The thickness of the preheated conventional composites is significantly lower than those at room temperature. The conventional composites provide film thickness values greater than those of the flowable composites regardless of preheating temperature.

  8. Low and high velocity impact response of thick hybrid composites

    Science.gov (United States)

    Hiel, Clement; Ishai, Ori

    1993-01-01

    The effects of low and high velocity impact on thick hybrid composites (THC's) were experimentally compared. Test Beams consisted of CFRP skins which were bonded onto an interleaved syntactic foam core and cured at 177 C (350 F). The impactor tip for both cases was a 16 mm (0.625 inch) steel hemisphere. In spite of the order of magnitude difference in velocity ranges and impactor weights, similar relationships between impact energy, damage size, and residual strength were found. The dependence of the skin compressive strength on damage size agree well with analytical open hole models for composite laminates and may enable the prediction of ultimate performance for the damaged composite, based on visual inspection.

  9. Synthesis and mechanical characterization of PZT/Sr based composite ceramics with addition of Si{sub 3}N{sub 4}; Sintese e caracterizacao mecanica de ceramicas compositas a base de PZT/Sr com adicoes de Si{sub 3}N{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Santos, M.A.P.; Santos, R.C.P.; Santos, M.C.C.; Rocha, C.D.G.; Silva, M., E-mail: cida@ipqm.mar.mil.b [Instituto de Pesquisas da Marinha (IPqM), Ilha do Governador, RJ (Brazil). Grupo de Materiais

    2010-07-01

    In the Underwater Acoustics field, piezoelectric ceramics are the most usually employed materials for the conversion of mechanical energy (acoustic signal) into electric energy (electric signal) and vice-versa, in sensors (hydrophones) or hydroacoustic projectors. In the development of new compositions for these applications, piezoelectric performance is generally prioritized, to the expense of its mechanical properties. With this in mind, the object of this work was to study the effects of the addition of Si{sub 3}N{sub 4} in the mechanical properties of PZT-Sr based electronic ceramics. Thus, a novel piezoelectric ceramic with the addition of small percentages in weight (0;0.1;1;3 and 5) of the structural ceramic Si{sub 3}N{sub 4} was successfully processed by the oxide mixing route ; the compounds were sintered in a conventional at 1200 deg C for 2h. The densities of the compounds thus obtained for the different percentages of Si{sub 3}N{sub 4} ranged from 55 to 97% and decreased with the increase of the content of Si{sub 3}N{sub 4}. Presence of equiaxial grains with normal growth was observed in all samples. MEV/EDS analysis of the micro-structures of the compositions detected the presence of a second phase rich in Zr, confirmed by DRX, which is a result of large quantities of volatilized PbO; the sintered pieces had their mechanical properties investigated by ultra-sonic inspection. It was observed that, among the sintered compositions, the PZT-Sr ceramic with 0.1% Si{sub 3}N{sub 4} presented the smallest value for Young's Modulus E and Shear Modulus G, 75 Gpa and 28 Gpa, respectively. The Poisson's Coefficients {nu} tended to decrease with the increase of Si{sub 3}N{sub 4} added to the PZT-Sr ceramic, indicating, thus, that the added compound may be used to adjust the mechanical properties of the material. (author)

  10. Economical Fabrication of Thick-Section Ceramic Matrix Composites

    Science.gov (United States)

    Babcock, Jason; Ramachandran, Gautham; Williams, Brian; Benander, Robert

    2010-01-01

    A method was developed for producing thick-section [>2 in. (approx.5 cm)], continuous fiber-reinforced ceramic matrix composites (CMCs). Ultramet-modified fiber interface coating and melt infiltration processing, developed previously for thin-section components, were used for the fabrication of CMCs that were an order of magnitude greater in thickness [up to 2.5 in. (approx.6.4 cm)]. Melt processing first involves infiltration of a fiber preform with the desired interface coating, and then with carbon to partially densify the preform. A molten refractory metal is then infiltrated and reacts with the excess carbon to form the carbide matrix without damaging the fiber reinforcement. Infiltration occurs from the inside out as the molten metal fills virtually all the available void space. Densification to 41 ksi (approx. 283 MPa) flexural strength.

  11. Temperature Dependent Electrical Properties of PZT Wafer

    Science.gov (United States)

    Basu, T.; Sen, S.; Seal, A.; Sen, A.

    2016-04-01

    The electrical and electromechanical properties of lead zirconate titanate (PZT) wafers were investigated and compared with PZT bulk. PZT wafers were prepared by tape casting technique. The transition temperature of both the PZT forms remained the same. The transition from an asymmetric to a symmetric shape was observed for PZT wafers at higher temperature. The piezoelectric coefficient (d 33) values obtained were 560 pc/N and 234 pc/N, and the electromechanical coupling coefficient (k p) values were 0.68 and 0.49 for bulk and wafer, respectively. The reduction in polarization after fatigue was only ~3% in case of PZT bulk and ~7% for PZT wafer.

  12. Determination of body composition from skinfold thickness: a validation study.

    Science.gov (United States)

    Reilly, J J; Wilson, J; Durnin, J V

    1995-01-01

    Measurement of body composition is proving increasingly important in clinical nutrition and research. Skinfold thickness is a simple means of estimating body composition which is widely used in children, but there is little information on its validity. There has been a proliferation of equations for estimation of body composition from skinfolds, but some doubt as to their general applicability. The aim of the present study was to validate five currently used equations for this purpose in a sample of 98 healthy prepubertal children (64 boys, 34 girls), mean (SD) age 9.1 (1.7) years by comparison of estimates from each equation with measurements of fatness derived from hydrodensitometry. Differences between methods were determined by calculation of biases and limits of agreement. Limits of agreement between predicted and measured fatness were wide, particularly in the girls, and some distinct biases were apparent. Choice of prediction equation therefore has a substantial influence on the estimate of fatness obtained when using skinfolds in children. The existing published equations are associated with large random errors or significant systematic errors. For the time being skinfolds might best be regarded as indices (rather than measures) of body fatness in individuals, or means of estimating body fatness of groups. Estimating the total body fatness of individual prepubertal children using skinfolds, on the basis of this evidence, is not advisable at present. PMID:7492193

  13. Flexible ultrasonic transducers for structural health monitoring of metals and composites

    Science.gov (United States)

    Kobayashi, M.; Wu, K.-T.; Shih, J.-L.; Jen, C.-K.; Kruger, S. E.

    2010-03-01

    Flexible ultrasonic transducers (FUTs) which have the on-site installation capability are presented for the non-destructive evaluation (NDE) and structural health monitoring (SHM) purposes. These FUTs consist of 75 μm thick titanium membrane, thick (> 70 μm) thick piezoelectric lead-zirconate-titanate (PZT) composite (PZT-c) films and thin (graphite/epoxy (Gr/Ep) composite are also used for the detection of artificial disbonds. An induction type non-contact method for the evaluation of Al plates and Gr/Ep composites using FUTs is also demonstrated.

  14. Properties of RF-Sputtered PZT Thin Films with Ti/Pt Electrodes

    Directory of Open Access Journals (Sweden)

    Cui Yan

    2014-01-01

    Full Text Available Effect of annealing temperature and thin film thickness on properties of Pb(Zr0.53Ti0.47O3 (PZT thin film deposited via radiofrequency magnetron sputtering technique onto Pt/Ti/SiO2/Si substrate was investigated. Average grain sizes of the PZT thin film were measured by atomic force microscope; their preferred orientation was studied through X-ray diffraction analysis. Average residual stress in the thin film was estimated according to the optimized Stoney formula, and impedance spectroscopy characterization was performed via an intelligent LCR measuring instrument. Average grain sizes of PZT thin films were 60 nm~90 nm and their average roughness was less than 2 nm. According to X-ray diffraction analysis, 600°C is the optimal annealing temperature to obtain the PZT thin film with better crystallization. Average residual stress showed that thermal mismatch was the decisive factor of residual stress in Pt/Ti/SiO2/Si substrate; the residual stress in PZT thin film decreased as their thickness increased and increased with annealing temperature. The dielectric constant and loss angle tangent were extremely increased with the thickness of PZT thin films. The capacitance of the device can be adjusted according to the thickness of PZT thin films.

  15. Scaling laws In PZT/Si(001) Thin Films

    Science.gov (United States)

    Ramírez, Juan; Cortes, Alexander; Lopera, Wilson; Gómez, Maria Elena; Prieto, Pedro

    2006-03-01

    Self-affine scaling behavior of ferroelectric Pb(Zr1-xTix)O3 (PZT) thin films grown on Si(001) substrates has been investigated by AFM Atomic Force Microscope. PZT thin films were grown via Rf-sputtering technique at high oxygen pressures and at substrate temperatures 600 ^oC varying the deposition time and keeping all parameters. growth constant. The α-global rough-exponent was founded close to 0.7 indicating a correlated growth. Anomalous scaling behavior was founded in all PZT/Si surfaces. A value of 0.5.for the α-local value was founded. The local value of the roughness exponent is associated to the diffusional process on the first stage growth. Saturation roughness showed oscillation dependence with the PZT-thickness. This dependence can be explained by the mismatch between Si substrate and PZT thin film. These results are corroborated calculating the grain size for all samples. This work was supported by COLCIENCIAS under the Excellence Center for Novel Materials Contract no 0043-2005.

  16. Temperature effects on the mechanical behaviour of PZT 95/5

    Science.gov (United States)

    Khan, A. S.; Balzer, J. E.; Wilgeroth, J. M.; Proud, W. G.

    2014-05-01

    This research is to develop a better understanding of the piezoelectric ceramic lead zirconate titanate (PZT) 95/5 with varying temperatures, porosities and strain rates. Here, unpoled PZT samples of two different porosities were subjected to a range of compression rates, using quasi-static loading equipment, drop-weight towers and Split Hopkinson Pressure Bars (SHPBs). Varying temperatures were achieved using purpose-made environmental chambers. The resulting stress-strain relationships are compared. The samples were square tiles, 7.5 × 7.5 mm and 3 mm thickness. The density of the standard PZT used here was 7.75 g cm-3 (henceforth described as PZT), whilst the density of the higher porosity PZT was 7.38 g cm-3 (henceforth described as PPZT). This research is part of a wider study.

  17. Fabrication and characterization of thick-film piezoelectric lead zirconate titanate ceramic resonators by tape-casting.

    Science.gov (United States)

    Qin, Lifeng; Sun, Yingying; Wang, Qing-Ming; Zhong, Youliang; Ou, Ming; Jiang, Zhishui; Tian, Wei

    2012-12-01

    In this paper, thick-film piezoelectric lead zirconate titanate (PZT) ceramic resonators with thicknesses down to tens of micrometers have been fabricated by tape-casting processing. PZT ceramic resonators with composition near the morphotropic phase boundary and with different dopants added were prepared for piezoelectric transducer applications. Material property characterization for these thick-film PZT resonators is essential for device design and applications. For the property characterization, a recently developed normalized electrical impedance spectrum method was used to determine the electromechanical coefficient and the complex piezoelectric, elastic, and dielectric coefficients from the electrical measurement of resonators using thick films. In this work, nine PZT thick-film resonators have been fabricated and characterized, and two different types of resonators, namely thickness longitudinal and transverse modes, were used for material property characterization. The results were compared with those determined by the IEEE standard method, and they agreed well. It was found that depending on the PZT formulation and dopants, the relative permittivities ε(T)(33)/ε(0) measured at 2 kHz for these thick-films are in the range of 1527 to 4829, piezoelectric stress constants (e(33) in the range of 15 to 26 C/m(2), piezoelectric strain constants (d(31)) in the range of -169 × 10(-12) C/N to -314 × 10(-12) C/N, electromechanical coupling coefficients (k(t)) in the range of 0.48 to 0.53, and k(31) in the range of 0.35 to 0.38. The characterization results shows tape-casting processing can be used to fabricate high-quality PZT thick-film resonators, and the extracted material constants can be used to for device design and application.

  18. Measurement and calculation of PZT thin film longitudinal piezoelectric coefficients.

    Energy Technology Data Exchange (ETDEWEB)

    Christman, J. A.; Kim, S.-H.; Kingon, A. I.; Maiwa, H.; Maria, J.-P.; Streiffer, S. K.

    1999-04-26

    The ferroelectric and piezoelectric properties of 2000 {angstrom} thick chemical solution deposited Pb(Zr{sub x}Ti{sub 1{minus}x})O{sub 3} (PZT) thin films were investigated. Several Zr/Ti ratios were studied: 30/70, 50/50 and 65/35, which correspond to tetragonal, near-morphotropic, and rhombohedral symmetries. In all samples, a {l_brace}111{r_brace}-texture is predominant. Longitudinal piezoelectric coefficients and their dc field dependence were measured using the contact AFM method. The expected trend of a maximum piezoelectric coefficient at or near to the MPB was not observed. The composition dependence was small, with the maximum d{sub 33} occurring in the tetragonal material. To explain the results, crystallographic texture and film thickness effects are suggested. Using a modified phenomenological approach, derived electrostrictive coefficients, and experimental data, d{sub 33} values were calculated. Qualitative agreement was observed between the measured and calculated coefficients. Justifications of modifications to the calculations are discussed.

  19. Variation in the thickness of the composite lute with an indirect composite inlay system.

    Science.gov (United States)

    Ariyaratnam, M; Wilson, M A; Wilson, N H; Watts, D C

    1990-11-01

    The findings of an initial investigation of variations in the thickness of the composite lute around inlays of a fine particle hybrid, light- and secondary-cured indirect composite resin inlay system are reported. The lute thickness varied between 10 microns and 90 microns, and was found to be thinnest and most uniform in the region of occlusal cavosurface margins. Although the marginal adaptation of the inlays investigated was generally considered to be satisfactory, sections of the lute were found to exhibit porosity and to contain a number of voids. It is concluded that whilst the lute thickness and marginal adaptation of composite bonded inlays of the type investigated may be found to be acceptable, further work is desirable to investigate ways to limit porosity and voids in lutes and to form and finish the cavomarginal elements of tooth-coloured inlays in such a way that the limiting layer of luting material may be better protected from the rigors of function in the oral environment.

  20. Measurement of effective piezoelectric coefficients of PZT thin films for energy harvesting application with interdigitated electrodes.

    Science.gov (United States)

    Chidambaram, Nachiappan; Mazzalai, Andrea; Muralt, Paul

    2012-08-01

    Interdigitated electrode (IDE) systems with lead zirconate titanate (PZT) thin films play an increasingly important role for two reasons: first, such a configuration generates higher voltages than parallel plate capacitor-type electrode (PPE) structures, and second, the application of an electric field leads to a compressive stress component in addition to the overall stress state, unlike a PPE structure, which results in tensile stress component. Because ceramics tend to crack at relatively moderate tensile stresses, this means that IDEs have a lower risk of cracking than PPEs. For these reasons, IDE systems are ideal for energy harvesting of vibration energy, and for actuators. Systematic investigations of PZT films with IDE systems have not yet been undertaken. In this work, we present results on the evaluation of the in-plane piezoelectric coefficients with IDE systems. Additionally, we also propose a simple and measurable figure of merit (FOM) to analyze and evaluate the relevant piezoelectric parameter for harvesting efficiency without the need to fabricate the energy harvesting device. Idealized effective coefficients e(IDE) and h(IDE) are derived, showing its composite nature with about one-third contribution of the transverse effect, and about two-thirds contribution of the longitudinal effect in the case of a PZT film deposited on a (100)-oriented silicon wafer with the in-plane electric field along one of the Si directions. Randomly oriented 1-μm-thick PZT 53/47 film deposited by a sol-gel technique, was evaluated and yielded an effective coefficient e(IDE) of 15 C·m(-2). Our FOM is the product between effective e and h coefficient representing twice the electrical energy density stored in the piezoelectric film per unit strain deformation (both for IDE and PPE systems). Assuming homogeneous fields between the fingers, and neglecting the contribution from below the electrode fingers, the FOM for IDE structures with larger electrode gap is derived to be

  1. Ferroelectric/electrode interfaces: Polarization switching and reliability of PZT capacitors in nonvolatile memories

    Science.gov (United States)

    Chen, Ye (Mike)

    The objective of this work was to investigate how the interface between electrode and PZT influences the PZT capacitor reliability. In order to conduct a well controlled experiment only the top-electrode PZT film interface was modified to study its effect on switching characteristics (i.e. hysteresis loop), voltage switching endurance and polarization retention of state of the art MOCVD grown film (nominally identical). The polycrystalline PZT film (50 -- 90 nm thick) are dominantly tetragonal with small fractions of the rhombohedral phase. XPS analyses of the as-deposited PZT film found the existence of a Pb-rich carbonate surface layer on all PZT film provided by industrial collaborators. Using materials characterizations such as in-situ XPS and ARXPS in tandem with electrical measurements it was determined that the Pb-rich surface layer appears to be an engineered sacrificial layer, which is beneficial in maximizing the switchable polarization and in improving the endurance and opposite-state retention behavior of PZT based FRAM capacitors with Pt electrode. This is because the excess Pb on the PZT surface and the Pb in the surface PZT reacts readily with the Pt during the Pt top electrode deposition creating a Pb-deficient non-ferroelectric interface layer between the top electrode and the PZT film. ARXPS analyses showed that this defective layer was approximately one nanometer thick and this is consistent with the hysteresis loop measurements that indicated a similar interface layer thickness. Inferior switching endurance and polarization retention was found in PZT film with an engineered initial thicker defective interface layer (via a HNO3-clean of the PZT surface prior to the top electrode deposition). This could be due to the fact that this defective interface layer may have thickened during the voltage cycling and/or retention bake. The thickening could be caused by greater carrier trapping and/or interface reaction between the Pb and the Pt. This

  2. Optical properties of PZT thin films deposited on a ZnO buffer layer

    OpenAIRE

    Schneider, T.; Leduc, D; Cardin, J.; LUPI, C; Barreau, N; Gundel, H.

    2015-01-01

    The optical properties of lead zirconate titanate (PZT) thin films deposited on ZnO were studied by m-lines spectroscopy. In order to retrieve the refractive index and the thickness of both layers from the m-lines spectra, we develop a numerical algorithm for the case of a two-layer system and show its robustness in the presence of noise. The sensitivity of the algorithm of the two-layer model allows us to relate the observed changes in the PZT refractive index to the PZT structural change du...

  3. Ultrasonic Wave Propagation in Thick, Layered Composites Containing Degraded Interfaces

    Science.gov (United States)

    2005-06-01

    and other materials for enhanced performance and reduced radar signatures. Whereas naval applications of composites have been historically limited to... applications of composites . Improvements in processing, inspection techniques and maintenance are described by Crane et al. [3]. Reliable and effective

  4. Influence of enamel composite thickness on value, chroma and translucency of a high and a nonhigh refractive index resin composite.

    Science.gov (United States)

    Ferraris, Federico; Diamantopoulou, Sofia; Acunzo, Raffaele; Alcidi, Renato

    2014-01-01

    To evaluate the influence of thickness on the optical properties of two enamel shade composites, one with a high refractive index and one traditional. A medium value enamel shade was selected from the resin composites Enamel Plus HRi (UE2) and Enamel Plus HFO (GE2). Enamel Plus HRi is a high refractive index composite. Samples were fabricated in five different thicknesses: 0.3, 0.5, 1, 1.5 and 2 mm. Three specimens per material and thickness were fabricated. Three measurements per sample, over white, black and dentin composite background were generated with a spectrophotometer (Spectroshade Micro, MHT). Value, chroma, translucency and color differences (ΔE) of the specimens were calculated. RESULTS were analyzed by the Pearson correlation test, ANOVA and a post-hoc Tukey test. Increasing the thickness of the enamel layers decreased the translucency and the chroma of the substrate for both materials tested. For HRi the increase of the thickness resulted in an increase of the value, whereas for HFO it resulted in a reduction of the value. The two composites showed a significant difference in value for each thickness, but not in translucency and chroma. Color difference between them was perceptible in layers equal or higher than 0.5 mm. The high refractive index enamel (HRi) composite exhibits different optical behavior compared to the traditional one (HFO). HRi enamel composite behaves more like natural enamel as by increasing the thickness of the enamel layer, the value also increases.

  5. Plasmonic assisted two wave mixing phenomenon for energy transfer in ferroelectric PZT film

    Science.gov (United States)

    Gupta, Reema; Kumari, Satchi; Tomar, Monika; Gupta, Vinay

    2017-04-01

    Ferroelectric - photorefractive PZT thin films have been exploited to study the energy transfer using pump probe technique for the development of optical delay lines. Two-wave mixing has been studied for three different PZT thin film samples deposited using pulsed laser deposition (PLD) technique. Uniform distribution of gold micro-discs of 40 nm thickness and 120 μm diameter over the surface of PZT thin film plays a vital role in enhancing the two-wave mixing. This is due to the ferroelectric domains present in PZT thin film which get polarized as a result of excited surface plasmons at the Au-PZT interface. The dual effect leads to an enhanced energy transfer from pump to 'Probe Beam'. The maximum two-wave mixing gain was found to be about 1.185 and 1.055 respectively for gold micro-discs patterned and bare PZT thin film deposited on STO substrate. In comparison, the PZT thin film covered completely with the gold overlayer does not show any significant two wave mixing gain due to the scattering of light by Au overlayer.

  6. Influence of light energy density on heat generation during photoactivation of dental composites with different dentin and composite thickness

    Directory of Open Access Journals (Sweden)

    Ricardo Danil Guiraldo

    2009-08-01

    Full Text Available OBJECTIVE: The aim of this study was to determine the influence of different energy densities on the heat generated during photoactivation of Filtek Z250 (3M/ESPE and Z100 (3M/ESPE composite resins with different dentin and composite thickness. MATERIAL AND METHODS: The temperature increase was registered with a type-K thermocouple connected to a digital thermometer (Iopetherm 46. A chemically polymerized acrylic resin base was prepared to serve as a guide for the thermocouple and as a support for 0.5-, 1.0-, and 1.5-mm-thick bovine dentin discs. Circular elastomer molds (1.0 mm-height x 3.0-mm diameter or 2.0-mm height x 3.0-mm diameter were adapted on the acrylic resin base to standardize the composite resin thickness. A conventional halogen light-curing unit (XL 2500, 3M/ESPE was used with light intensity of 700 mW/cm². Energy density was calculated by the light intensity applied during a certain time with values of 28 J/cm² for Z100 and 14 J/cm² for Filtek Z250. The temperature change data were subjected to three-way ANOVA and Tukey's test at 5% level. RESULTS: The higher energy density (Z100 promoted greater temperature increase (p<0.05 than the lower energy density (Filtek Z250. For both composites and all composite thicknesses, the lowest dentin thickness (0.5 mm yielded significantly higher (p<0.05 temperature increase than the other two dentin thicknesses. The 1-mm-thick composite resin layer yielded significantly higher (p<0.05 temperature changes for both composites and all dentin thicknesses. CONCLUSIONS: Temperature increase was influenced by higher energy density and dentin/composite thickness.

  7. Characterization of PZT thin films on metal substrates; Charakterisierung von PZT-Duennschichten auf Metallsubstraten

    Energy Technology Data Exchange (ETDEWEB)

    Dutschke, A.

    2008-02-02

    Lead zirconate titanate (PbZr{sub x}Ti{sub 1-x}O{sub 3},PZT) is one of the most applied ceramic materials because of its distinctive piezo- and ferroelectric properties. Prepared as thin films on flexible, metallic substrates it can be used for various applications as strain gauges, key switches, vibration dampers, microactuators and ultrasonic transducers. The aim of this work is to analyze the microstructure and the phase-content of PZT-thin films deposited on temperature- und acid-resistant hastelloy-sheets, to correlate the results with the ferroelectric and dielectric properties. It is demonstrated, that the specific variation of the microstructure can be achieved by different thermal treatments and the selective addition of Neodymium as dopant. Nd-doping leads to a shift of the maximum nucleation rate towards reduced temperatures and a decrease in the rate of growth compared to undoped films. The PZT-films are prepared by a sol-gel-process in fourfold multilayers with a composition near the morphotropic phase boundary, where the tetragonal und rhombohedral perovskite-phases coexist. The crystallisation in Nd-doped and undoped films takes place heterogeneously, preferentially at the interfaces and on the surface of the multilayered films as well as on the inner surface of pores within the films. For the first time, the Zr:Ti fluctuation phenomena emerging in sol-gel derived PZT films is related to the microstructure and the local phase content on a nanometer scale. In this connection it is proved, that long-distance Zr:Ti gradients arise preferentially before and during the crystallisation of the pyrochlore phase. During the following crystallisation of the perovskite phase, the crystallites grow across these gradients without modifying them. It is pointed out that the fluctuation in the Zr:Ti ratio has only minor influence on the amount of the tetragonal or rhombohedral distortion of the crystallites after the transition from the para- to the ferroelectric

  8. Airflow energy harvesters of metal-based PZT thin films by self-excited vibration

    Science.gov (United States)

    Suwa, E.; Tsujiura, Y.; Kurokawa, F.; Hida, H.; Kanno, I.

    2014-11-01

    We developed self-excited vibration energy harvesters of Pb(Zr,Ti)O3 (PZT) thin films using airflow. To enhance the self-excited vibration, we used 30-μm-thick stainless steel (SS304) foils as base cantilevers on which PZT thin films were deposited by rf-magnetron sputtering. To compensate for the initial bending of PZT/SS304 unimorph cantilever due to the thermal stress, we deposited counter PZT thin films on the back of the SS304 cantilever. We evaluated power-generation performance and vibration mode of the energy harvester in the airflow. When the angle of attack (AOA) was 20° to 30°, large vibration was generated at wind speeds over 8 m/s. By FFT analysis, we confirmed that stable self-excited vibration was generated. At the AOA of 30°, the output power reached 19 μW at wind speeds of 12 m/s.

  9. Thick film magnetic nanoparticulate composites and method of manufacture thereof

    Science.gov (United States)

    Ma, Xinqing (Inventor); Zhang, Yide (Inventor); Ge, Shihui (Inventor); Zhang, Zongtao (Inventor); Yan, Dajing (Inventor); Xiao, Danny T. (Inventor)

    2009-01-01

    Thick film magnetic/insulating nanocomposite materials, with significantly reduced core loss, and their manufacture are described. The insulator coated magnetic nanocomposite comprises one or more magnetic components, and an insulating component. The magnetic component comprises nanometer scale particles (about 1 to about 100 nanometers) coated by a thin-layered insulating phase. While the intergrain interaction between the immediate neighboring magnetic nanoparticles separated by the insulating phase provides the desired soft magnetic properties, the insulating material provides high resistivity, which reduces eddy current loss.

  10. Effect of preheating on the film thickness of contemporary composite restorative materials

    OpenAIRE

    Dimitrios Dionysopoulos; Kosmas Tolidis; Paris Gerasimou; Eugenia Koliniotou-Koumpia

    2014-01-01

    Background/purpose: Recently, the placement of composite materials at an elevated temperature has been proposed in order to increase their flow for better adaptation in cavity walls. The aim of this in vitro study was to evaluate the effect of preheating on the film thickness of a variety of commercially available conventional composites and to compare them with those obtained from a variety of flowable composites at room temperature. Materials and methods: The composites were three nanohy...

  11. Far infrared and Raman response in tetragonal PZT ceramic films

    Energy Technology Data Exchange (ETDEWEB)

    Buixaderas, E.; Kadlec, C.; Vanek, P.; Drnovsek, S.; Ursic, H.; Malic, B.

    2015-07-01

    PbZr{sub 0}.38Ti{sub 0}.62O{sub 3} and PbZr{sub 0}.36Ti{sub 0}.64{sub O}3 thick films deposited by screen printing on (0 0 0 1) single crystal sapphire substrates and prepared at two different sintering temperatures, were studied by Fourier-transform infrared reflectivity, time-domain TH{sub z} transmission spectroscopy and micro-Raman spectroscopy. The dielectric response is discussed using the Lichtenecker model to account for the porosity of the films and to obtain the dense bulk dielectric functions. Results are compared with bulk tetragonal PZT 42/58 ceramics. The dynamic response in the films is dominated by an overdamped lead-based vibration in the TH{sub z} range, as known in PZT, but its evaluated dielectric contribution is affected by the porosity and roughness of the surface. (Author)

  12. Quantifying Local Thickness and Composition in Thin Films of Organic Photovoltaic Blends by Raman Scattering

    KAUST Repository

    Rodríguez-Martínez, Xabier

    2017-07-06

    We report a methodology based on Raman spectroscopy that enables the non-invasive and fast quantitative determination of local thickness and composition in thin films (from few monolayers to hundreds of nm) of one or more components. We apply our methodology to blends of organic conjugated materials relevant in the field of organic photovoltaics. As a first step, we exploit the transfer-matrix formalism to describe the Raman process in thin films including reabsorption and interference effects of the incoming and scattered electric fields. This allows determining the effective solid-state Raman cross-section of each material by studying the dependence of the Raman intensity on film thickness. These effective cross sections are then used to estimate the local thickness and composition in a series of polymer:fullerene blends. We find that the model is accurate within ±10 nm in thickness and ±5 vol% in composition provided that (i) the film thickness is kept below the thickness corresponding to the first maximum of the calculated Raman intensity oscillation; (ii) the materials making up the blend show close enough effective Raman cross-sections; and (iii) the degree of order attained by the conjugated polymer in the blend is similar to that achieved when cast alone. Our methodology opens the possibility to make quantitative maps of composition and thickness over large areas (from microns to centimetres squared) with diffraction-limited resolution and in any multi-component system based thin film technology.

  13. Influence of increment thickness on dentin bond strength and light transmission of composite base materials.

    Science.gov (United States)

    Omran, Tarek A; Garoushi, Sufyan; Abdulmajeed, Aous A; Lassila, Lippo V; Vallittu, Pekka K

    2017-06-01

    Bulk-fill resin composites (BFCs) are gaining popularity in restorative dentistry due to the reduced chair time and ease of application. This study aimed to evaluate the influence of increment thickness on dentin bond strength and light transmission of different BFCs and a new discontinuous fiber-reinforced composite. One hundred eighty extracted sound human molars were prepared for a shear bond strength (SBS) test. The teeth were divided into four groups (n = 45) according to the resin composite used: regular particulate filler resin composite: (1) G-ænial Anterior [GA] (control); bulk-fill resin composites: (2) Tetric EvoCeram Bulk Fill [TEBF] and (3) SDR; and discontinuous fiber-reinforced composite: (4) everX Posterior [EXP]. Each group was subdivided according to increment thickness (2, 4, and 6 mm). The irradiance power through the material of all groups/subgroups was quantified (MARC® Resin Calibrator; BlueLight Analytics Inc.). Data were analyzed using two-way ANOVA followed by Tukey's post hoc test. SBS and light irradiance decreased as the increment's height increased (p composite used. EXP presented the highest SBS in 2- and 4-mm-thick increments when compared to other composites, although the differences were not statistically significant (p > 0.05). Light irradiance mean values arranged in descending order were (p composites. Discontinuous fiber-reinforced composite showed the highest value of curing light transmission, which was also seen in improved bonding strength to the underlying dentin surface. Discontinuous fiber-reinforced composite can be applied safely in bulks of 4-mm increments same as other bulk-fill composites, although, in 2-mm thickness, the investigated composites showed better performance.

  14. Performance of PZT8 Versus PZT4 Piezoceramic Materials in Ultrasonic Transducers

    Science.gov (United States)

    DeAngelis, Dominick A.; Schulze, Gary W.

    PZT8 and PZT4 are the common "hard" piezoceramic materials used in power ultrasonic transducers (e.g., welding, cutting, sonar, etc.). PZT8 is perceived as the better choice for resonant devices, primarily due to its higher mechanical quality factor Qm. PZT8 is also considered a "harder" material compared to PZT4, since it has better stability at higher preloads and drive levels. Many transducer designers never consider PZT4 for their applications, even though it has clear advantages such as higher output (i.e., higher d33). Even the perceived advantage of PZT8 regarding Qm may not be significant for most Langevin, bolted stack type transducers if the mechanical joint losses dominate. This research is a case study on the performance of identical ultrasonic transducers used for semiconductor wire bonding, assembled with either PZT8 or PZT4 materials. The main purpose of the study is to establish rule-of-thumb transducer design guidelines for the selection of PZT8 versus PZT4 materials. Several metrics are investigated such as impedance, frequency, capacitance, dielectric loss, Qm, heating, displacement gain, and electro-mechanical coupling factor. The experimental and theoretical research methods include Bode plots, thermal IR camera imaging, scanning laser vibrometry and coupled-field finite element analysis.

  15. EFFECT OF SOL CONCENTRATION AND SUBSTRATE TYPE ON MICROSTRUCTURE FORMATION OF PZT THIN FILMS

    Directory of Open Access Journals (Sweden)

    ĽUBOMÍR MEDVECKÝ

    2011-03-01

    Full Text Available Pb(Zr0.52Ti0.48O3 (PZT sols were prepared by a modified sol-gel route using both solvents - acetic acid and stabilizer solution (n-propanol : 1,2-propanediol in the rate 10 : 1. The sols were deposited by spin-coating onto platinized Al2O3 or SiO2/Si substrates. Results of SEM and XRD analyses confirmed, that the transformation of the amorphous PZT film to perovskite structure happened after sintering at 650°C. The mechanism of microstructure formation has described for morphologicaly different perovskite particle types in 1, 2 and 3-layered PZT thin films with thickness of 200-500 nm on used substrates. Three different PZT film microstructure types in dependence on the applied sol concentration were found. It was found, that the PZT/Pt/Al2O3 film microstructure at 1.0 M sol concentration was composed of two forms of perovskite particles, big rosette and irregular cuboidal particles. Small spherical particles and rosette structure were found in PZT/Pt/Si/SiO2 films.

  16. Ferrite-Piezoelectric Layered Composites: Synthesis and Magnetoelectric Characterization

    Science.gov (United States)

    Hayes, R. W.; Srinivasan, G.

    2004-10-01

    The observation of strong magnetoelectric effects is reported in thick film bilayers and multilayers of ferrite-lead titanate zirconate (PZT). The ferrites used in our studies included pure and zinc substituted cobalt-, nickel- and lithium ferrites. Samples were prepared by sintering 10-40 mm thick films obtained by tape-casting. Measurements of ME voltage coefficients at 10-1000 Hz indicated a giant ME effect in nickel ferrite-PZT, but a relatively weak coupling in other ferrite-PZT systems. Evidence was found for enhancement in ME coefficients when Zn was substituted in ferrites. The Zn-assisted increase was attributed to low anisotropy and high permeability that resulted in favorable magneto-mechanical coupling in the composites. G. Srinivasan, E. T. Rasmussen, and R. Hayes, Phys. Rev. B 67, 014418 (2003) Supported by NSF and ARO grants.

  17. Microwave Hydrothermal Synthesis PZT of Nanometer Crystal

    Institute of Scientific and Technical Information of China (English)

    Hongxing LIU; Hong DENG; Yan LI; Yanrong LI

    2004-01-01

    It was focused on the applications and developments of microwave hydrothermal synthesis piezoelectric ceramic powder. The microwave hydrothermal vessel was designed and manufactured. The microwave hydrothermal synthesis system was established and the PZT piezoelectric ceramic powder was synthesized. XRD and TEM have been used to characterize the products in detail. The diameter of the PZT powder particle is from 40 to 60 nm.

  18. Simulation Studies on the Settlement of Composite Foundation with Contact Element of Zero Thickness

    Institute of Scientific and Technical Information of China (English)

    Dong Bichang; Wang Jingtao; Cheng Tao

    2005-01-01

    The various factors influencing the settlement of composite foundation have been more completely studied through numerical simulation. The influence on the settlement of composite foundation of the geometry and mechanical properties of the pile, soil, cushion, and the interface between pile and soil have been investigated through computer simulation, in which the contact elements with zero thickness are used. Some valuable conclusions for the settlement of composite foundation have been obtained: (1) The method using the contact element of zero thickness is successful when used in the simulation of the settlement of composite foundation; (2) Among the factors influencing the settlement of composite foundation, the compression modulus of the soil is the largest, and the cohesion of the soil is the second largest; (3) The effects on settlement of the internal friction angle of the soil, the elastic modulus, the radius, and the length of the pile, and the elestic modulus of the cushion are also more obvious.

  19. Comparison of ultrasonography and skinfold measurements of subcutaneous fat thickness in the evaluation of body composition

    OpenAIRE

    Akyer, Şahika Pınar; Adıgüzel, Esat; Sabir, Nuran; Akdoğan, Ilgaz; Yılmaz, Birsen; yonguç, gökşin nilüfer

    2014-01-01

    Objectives:To determine the amount of body fat tissue with skinfold thickness measurements is a common method to estimate the body composition. The other method used for this purpose is ultrasonography which is expensive and needs specialization to apply. In this study, validity of skinfold thickness measurements was investigated using ultrasonography. Methods: One hundred adult volunteers (50 males and 50 females) were used in this study. The ages of the subjects were 20to 70, selected as10 ...

  20. Translucency and Masking Ability of Various Composite Resins at Different Thicknesses

    Directory of Open Access Journals (Sweden)

    Farideh Darabi

    2014-09-01

    Full Text Available Statement of the Problem: Optical properties of the composite resins, concerning their translucency and thickness, are affected by discolored tooth structure or inherent darkness of the oral cavity. Purpose: This study aimed to compare the translucency parameter (TP of five different composite resins in different thicknesses and to evaluate their masking ability in black backgrounds. Materials and Method: Five brands of composite resins; Gradia (GC and Crystalline (Confi-dental in opaque A2 (OA2, Vit-l-escence (Ultradent in opaque snow (OS, Herculite XRV (Kerr and Opallis (FGM in dentin A2 (DA2 shades were selected to enroll the study. Color coordinates of each composite were determined at 0.5, 1, and 1.5 mm thicknesses on a white backing, the backing of material itself and a black backing were calculated by using a spectrophotometer to evaluate the translucency parameter (TP of the study materials. The masking ability was also calculated from the specimens on the material itself and on black backing. The values under 2 were estimated as im-perceptible. One-way ANOVA, T-test and Tukey HSD were employed for statistical analysis. Results: The masking ability values, recorded for the 1.5 mm-thick specimens, were in the range of imperceptible except for the Herculite. There was no difference in TP values of the materials at 1.5 mm thickness. Opaque snow shade of Vit-l-escence and opaque A2 shade of Gradia showed lower TP values in comparison with the other 1 and 0.5 mm-thick materials and this difference was statistically significant (p< 0.05. Conclusion: In relatively thin thicknesses (≤1mm, these opaque/dentin shade composite resins could not mask the black background color.

  1. Thickness effect on electric resistivity on polystyrene and carbon black- based composites

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Lopez, S; Vigueras-Santiago, E [Laboratorio de Investigacion y Desarrollo de Materiales Avanzados (LIDMA) Facultad de Quimica, Paseo Colon Esquina con Paseo Tollocan, s/n, CP 50000, Toluca (Mexico); Mayorga-Rojas, M; Reyes-Contreras, D, E-mail: eviguerass@uaemex.m [Facultad de Ciencias, Universidad Autonoma del Estado de Mexico. Av. Instituto Literario 100 Ote. C. P. 50000, Toluca (Mexico)

    2009-05-01

    Changes on electrical resistivity were experimentally studied for polystyrene and carbon black-based composites respect to the temperature. 22% w/w carbon black composite films at 30{mu}m, 2mm y 1cm thick were submitted to thermal heating-cooling cycles from room temperature to 100 deg. C, slightly up to T{sub g} of the composite. For each cycle changes on electrical resistivity constituent a hysteresis loop that depends on the sample thickness. The changes during the heating stage could be explained as a consequence of the thermal expansion and mobility of the polymer chains at T{sub g}, producing a disconnecting of the electrical contacts among carbon black particles and an important increasing (200%) of the electrical resistivity. For each cycle, the hysteresis loop was observed in thicker samples, whereas for 30 mu m thickness sample the hysteresis loop was lost after four cycles.

  2. Effect of coating thickness on microstructures and mechanical properties of C/Cu/Al composites

    Institute of Scientific and Technical Information of China (English)

    CAO Zhuo-kun; YAO Guang-chun; LIU Yi-han

    2006-01-01

    The different copper coatings with thickness varying from 0.3 μm to 1.5 μtm were deposited on carbon fibers using either electroless plating or electroplating method. The coated fibers were chopped and composites were fabricated with melting aluminum at 700 ℃. The effect of the copper layer on the microstructure in the system was discussed. The results show that the copper layer has fully reacted with aluminum matrix, and the intermetallic compound CuAl2 forms through SEM observation and XRD, EDX analysis. The results of tensile tests indicate that composites fabricated using carbon fibers with 0.7-1.1 μm copper coating perform best and the composites turn to more brittle as the thickness of copper coating increases. The fracture surface observation exhibits good interface bonding and ductility of the matrix alloy when the thickness of copper coating is about 0.7-1.1 μm.

  3. Influence of curing time, overlay material and thickness on three light-curing composites used for luting indirect composite restorations.

    Science.gov (United States)

    D'Arcangelo, Camillo; De Angelis, Francesco; Vadini, Mirco; Carluccio, Fabio; Vitalone, Laura Merla; D'Amario, Maurizio

    2012-08-01

    To assess the microhardness of three resin composites employed in the adhesive luting of indirect composite restorations and examine the influence of the overlay material and thickness as well as the curing time on polymerization rate. Three commercially available resin composites were selected: Enamel Plus HRI (Micerium) (ENA), Saremco ELS (Saremco Dental) (SAR), Esthet-X HD (Dentsply/DeTrey) (EST-X). Post-polymerized cylinders of 6 different thicknesses were produced and used as overlays: 2 mm, 3 mm, 3.5 mm, 4 mm, 5 mm, and 6 mm. Two-mm-thick disks were produced and employed as underlays. A standardized amount of composite paste was placed between the underlay and the overlay surfaces which were maintained at a fixed distance of 0.5 mm. Light curing of the luting composite layer was performed through the overlays for 40, 80, or 120 s. For each specimen, the composite to be cured, the cured overlay, and the underlay were made out of the same batch of resin composite. All specimens were assigned to three experimental groups on the basis of the resin composite used, and to subgroups on the basis of the overlay thickness and the curing time, resulting in 54 experimental subgroups (n = 5). Forty-five additional specimens, 15 for each material under investigation, were produced and subjected to 40, 80, or 120 s of light curing using a microscope glass as an overlay; they were assigned to 9 control subgroups (n = 5). Three Vicker's hardness (VH) indentations were performed on each specimen. Means and standard deviations were calculated. Data were statistically analyzed using 3-way ANOVA. Within the same material, VH values lower than 55% of control were not considered acceptable. The used material, the overlay thickness, and the curing time significantly influenced VH values. In the ENA group, acceptable hardness values were achieved with 3.5-mm or thinner overlays after 120 or 80 s curing time (VH 41.75 and 39.32, respectively), and with 2-mm overlays after 40 s (VH 54

  4. Effect of laminate thickness on moisture diffusion of polymer matrix composites in artificial seawater ageing

    Science.gov (United States)

    Pal, Ratna; Narasimha Murthy, H. N.; Sreejith, M.; Vishnu Mahesh, K. R.; Krishna, M.; Sharma, S. C.

    2012-09-01

    The influence of laminate thickness of polymer matrix composites on moisture diffusion in seawater immersion, as well as the resulting mechanical property degradation for composites of glass/isopolyester (G/IPE), carbon/isopolyester (C/IPE), glass/vinylester (G/VE) and carbon/vinylester (C/VE), was investigated in this paper. Laminates 3 and 10mm in thickness, fabricated using the wet hand lay-up technique, were characterized for moisture absorption in artificial seawater medium, and their flexural strength and interlaminar shear strength (ILSS) degradations were studied. Moisture diffusion was observed to be anamolous to the Fick's law for both 3 and 10mm thick samples in the later stage of diffusion. Moisture permeability of 10mmthick samples was two to three order greater than that of 3mm thick ones, while the time to moisture saturation remained unchanged. With the increase of laminate thickness, moisture saturation increased by 1.4% for C/VE and 7% for G/IPE. The residual flexural strength and ILSS were greater in case of 10mm thick specimens after 200 days of exposure. SEM examination of the fractured specimens showed greater levels of fibre/matrix debonding in 10mm thick specimens.

  5. PZT thin films for piezoelectric MEMS mechanical energy harvesting

    Science.gov (United States)

    Yeager, Charles

    This thesis describes the optimization of piezoelectric Pb(ZrxTi 1-x)O3 (PZT) thin films for energy generation by mechanical energy harvesting, and self-powered micro-electro-mechanical systems (MEMS). For this purpose, optimization of the material was studied, as was the incorporation of piezoelectric films into low frequency mechanical harvesters. A systematic analysis of the energy harvesting figure of merit was made. As a figure of merit (e31,ƒ)2/epsilon r (transverse piezoelectric coefficient squared over relative permittivity) was utilized. PZT films of several tetragonal compositions were grown on CaF2, MgO, SrTiO3, and Si substrates, thereby separating the dependence of composition on domain orientation. To minimize artifacts associated with composition gradients, and to extend the temperature growth window, PZT films were grown by metal organic chemical vapor deposition (MOCVD). Using this method, epitaxial {001} films achieved c-domain textures above 90% on single crystal MgO and CaF2 substrates. This could be tailored via the thermal stresses established by the differences in thermal expansion coefficients of the film and the substrate. The single-domain e31,ƒ for PZT thin films was determined to exceed -12 C/m2 in the tetragonal phase field for x ≥ 0.19, nearly twice the phenomenologically modeled value. The utilization of c-domain PZT films is motivated by a figure of merit above 0.8 C2/m4 for (001) PZT thin films. Increases to the FoM via doping and hot poling were also quantified; a 1% Mn doping reduced epsilonr by 20% without decreasing the piezoelectric coefficient. Hot poling a device for one hour above 120°C also resulted in a 20% reduction in epsilonr ; furthermore, 1% Mn doping reduced epsilonr by another 12% upon hot poling. Two methods for fabricating thin film mechanical energy harvesting devices were investigated. It was found that phosphoric acid solutions could be used to pattern MgO crystals, but this was typically accompanied by

  6. The Influence of the Thickness of the Slab and Concrete Grade on Composite Floors

    OpenAIRE

    Vasile-Mircea Venghiac; Cedric D’Mello

    2010-01-01

    A modern flooring system is the ComFloor Composite Floor Deck from Corus. This type of floor has many advantages involving cost, weight, construction speed, but also disadvantages regarding vibrations induced by human activity. The vibration behaviour of this system was analysed taking into consideration two parameters: the thickness of the slab and the grade of the concrete. Two sets of models were made, one with composite beams and one with steel beams. The purpose was to make a comparison ...

  7. Instantaneous crack detection using dual PZT transducers

    Science.gov (United States)

    Kim, Seung Bum; Sohn, Hoon

    2008-03-01

    A new guided wave based nondestructive testing (NDT) technique is developed to detect crack damage in metallic plates commonly used in aircraft without using prior baseline data or a predetermined decision boundary. In conventional guided wave based techniques, damage is often identified by comparing the "current" data obtained from a potentially damaged condition of a structure with the "past" baseline data collected at the pristine condition of the structure. However, it has been reported that this type of pattern comparison with the baseline data can lead to increased false alarms due to its susceptibility to varying operational and environmental conditions of the structure. In order to tackle this issue, a reference-free damage detection technique is previously developed using two pairs of collocated lead zirconate titanate transducers (PZTs) placed on both sides of a plate. In this study, this reference-free technique is further advanced so that the PZT transducers can be placed only on one side of the specimen. Crack formation creates Lamb wave mode conversion due to a sudden change in the thickness of the structure. Then, the proposed technique instantly detects the appearance of the crack by extracting this mode conversion from the measured Lamb waves. This study suggests a reference-free statistical approach that enables damage classification using only the current data set. Numerical and experimental results are presented to demonstrate the applicability of the proposed technique to instantaneous crack detection.

  8. TEMPLATE-ASSISTED FABRICATION AND DIELECTROPHORETIC MANIPULATION OF PZT MICROTUBES

    Directory of Open Access Journals (Sweden)

    VLADIMÍR KOVAĽ

    2012-09-01

    Full Text Available Mesoscopic high aspect ratio ferroelectric tube structures of a diverse range of compositions with tailored physical properties can be used as key components in miniaturized flexible electronics, nano- and micro-electro-mechanical systems, nonvolatile FeRAM memories, and tunable photonic applications. They are usually produced through advanced “bottom-up” or “topdown” fabrication techniques. In this study, a template wetting approach is employed for fabrication of Pb(Zr0.52Ti0.48O3 (PZT microtubes. The method is based on repeated infiltration of precursor solution into macroporous silicon (Si templates at a sub-atmospheric pressure. Prior to crystallization at 750°C, free-standing tubes of a 2-μm outer diameter, extending to over 30 μm in length were released from the Si template using a selective isotropic-pulsed XeF2 reactive ion etching. To facilitate rapid electrical characterization and enable future integration process, directed positioning and aligning of the PZT tubes was performed by dielectrophoresis. The electric field-assisted technique involves an alternating electric voltage that is applied through pre-patterned microelectrodes to a colloidal suspension of PZT tubes dispersed in isopropyl alcohol. The most efficient biasing for the assembly of tubes across the electrode gap of 12 μm was a square wave signal of 5 Vrms and 10 Hz. By varying the applied frequency in between 1 and 10 Hz, an enhancement in tube alignment was obtained.

  9. Quantitative CT: Associations between Emphysema, Airway Wall Thickness and Body Composition in COPD

    DEFF Research Database (Denmark)

    Rutten, Erica P A; Grydeland, Thomas B; Pillai, Sreekumar G

    2011-01-01

    The objective of the present study was to determine the association between CT phenotypes-emphysema by low attenuation area and bronchitis by airway wall thickness-and body composition parameters in a large cohort of subjects with and without COPD. In 452 COPD subjects and 459 subjects without COPD...

  10. Tensile strength of thin resin composite layers as a function of layer thickness.

    Science.gov (United States)

    Alster, D; Feilzer, A J; De Gee, A J; Davidson, C L

    1995-11-01

    As a rule, cast restorations do not allow for free curing contraction of the resin composite luting cement. In a rigid situation, the resulting contraction stress is inversely proportional to the resin layer thickness. Adhesive technology has demonstrated, however, that thin joints may be considerably stronger than thicker ones. To investigate the effects of layer thickness and contraction stress on the tensile strength of resin composite joints, we cured cylindrical samples of a chemically initiated resin composite (Clearfil F2) in restrained conditions and subsequently loaded them in tension. The samples had a diameter of 5.35 mm and thicknesses of 50, 100, 200, 300, 400, 500, 600, and 700 microns, 1.4 mm, or 2.7 mm. None of the samples fractured due to contraction stress prior to tensile loading. Tensile strength decreased gradually from 62 +/- 2 MPa for the 50-microns layer to 31 +/- 4 MPa for the 2.7-mm layer. The failures were exclusively cohesive in resin for layers between 50 and 400 microns thick. Between 500 and 700 microns, the failures were cohesive or mixed adhesive/cohesive, while the 1.4- and 2.7-mm layers always failed in a mixed adhesive/cohesive mode. For the resin composite tested, the contraction stress did not endanger the cohesive strength. It was concluded that if adhesion to tooth structure were improved, thinner adhesive joints might enhance the clinical success of luted restorations.

  11. Thickness dependence of oxygen permeation through erbia-stabilized bismuth oxide-silver composites

    NARCIS (Netherlands)

    Chen, C.S.; Kruidhof, H.; Bouwmeester, H.J.M.; Verweij, H.; Burggraaf, A.J.

    1997-01-01

    Oxygen permeation measurements were performed on erbia-stabilized bismuth oxide-silver (40 v/o) composite membranes in the range of thickness of 1.60–0.23 mm and temperature of 850–650 °C. Air was fed at one side of the membranes while permeated oxygen on the other side was swept away with helium. A

  12. The influence of varying layer thicknesses on the color predictability of two different composite layering concepts

    NARCIS (Netherlands)

    G. Khashayar; A. Dozic; C.J. Kleverlaan; A.J. Feilzer

    2014-01-01

    Objective Optical properties of teeth are mimicked by composite layering techniques by combining a relatively opaque layer (dentin) with more translucent layers (enamel). However, the replacing material cannot always optically imitate the tooth when applied in the same thickness as that of the natur

  13. Polarization characterization of PZT disks and of embedded PZT plates by thermal wave methods

    Energy Technology Data Exchange (ETDEWEB)

    Eydam, Agnes, E-mail: Agnes.Eydam@tu-dresden.de; Suchaneck, Gunnar, E-mail: Agnes.Eydam@tu-dresden.de; Gerlach, Gerald [Technische Universität Dresden, Solid State Electronics Laboratory, Helmholtzstraße 18, 01062 Dresden (Germany); Esslinger, Sophia; Schönecker, Andreas; Neumeister, Peter [Fraunhofer Institute for Ceramic Technologies and Systems, Winterbergstraße 28, 01277 Dresden (Germany)

    2014-11-05

    In this work, the thermal wave method was applied to characterize PZT disks and embedded PZT plates with regard to the polarization magnitude and spatial homogeneity. The samples were exposed to periodic heating by means of a laser beam and the pyroelectric response was determined. Thermal relaxation times (single time constants or distributions of time constants) describe the heat losses of the PZT samples to the environment. The resulting pyroelectric current spectrum was fitted to the superposition of thermal relaxation processes. The pyroelectric coefficient gives insight in the polarization distribution. For PZT disks, the polarization distribution in the surface region showed a characteristic decrease towards the electrodes.

  14. Alginate-magnesium aluminum silicate composite films: effect of film thickness on physical characteristics and permeability.

    Science.gov (United States)

    Pongjanyakul, Thaned; Puttipipatkhachorn, Satit

    2008-01-04

    The different film thicknesses of the sodium alginate-magnesium aluminum silicate (SA-MAS) microcomposite films were prepared by varying volumes of the composite dispersion for casting. Effect of film thickness on thermal behavior, solid-state crystallinity, mechanical properties, water uptake and erosion, and water vapor and drug permeability of the microcomposite films were investigated. The film thickness caused a small change in thermal behavior of the films when tested using DSC and TGA. The crystallinity of the thin films seemed to increase when compared with the thick films. The thin films gave higher tensile strength than the thick films, whereas % elongation of the films was on the contrary resulted in the lower Young's modulus of the films when the film thickness was increased. This was due to the weaker of the film bulk, suggesting that the microscopic matrix structure of the thick films was looser than that of the thin films. Consequently, water uptake and erosion, water vapor permeation and drug diffusion coefficient of the thick films were higher than those of the thin films. The different types of drug on permeability of the films also showed that a positive charge and large molecule of drug, propranolol HCl, had higher lag time and lower diffusion coefficient that acetaminophen, a non-electrolyte and small molecule. This was because of a higher affinity of positive charge drug on MAS in the films. The findings suggest that the evaporation rate of solvent in different volumes of the composite dispersion used in the preparation method could affect crystallinity and strength of the film surface and film bulk of the microcomposite films. This led to a change in water vapor and drug permeability of the films.

  15. Influence of light curing and sample thickness on microhardness of a composite resin

    Directory of Open Access Journals (Sweden)

    Flávio HB Aguiar

    2009-05-01

    Full Text Available Flávio HB Aguiar1, Kelly RM Andrade1, Débora AN Leite Lima1, Gláucia MB Ambrosano2, José R Lovadino11Department of Restorative Dentistry; 2Department of Social Dentistry/Statistics, Piracicaba Dental School, State University of Campinas, SP, BrazilAbstract: The aim of this in vitro study was to evaluate the influence of light-curing units and different sample thicknesses on the microhardness of a composite resin. Composite resin specimens were randomly prepared and assigned to nine experimental groups (n = 5: considering three light-curing units (conventional quartz tungsten halogen [QTH]: 550 mW/cm2 – 20 s; high irradiance QTH: 1160 mW/cm2 – 10 s; and light-emitting diode [LED]: 360 mW/cm2 – 40 s and three sample thicknesses (0.5 mm, 1 mm, and 2 mm. All samples were polymerized with the light tip 8 mm away from the specimen. Knoop microhardness was then measured on the top and bottom surfaces of each sample. The top surfaces, with some exceptions, were almost similar; however, in relation to the bottom surfaces, statistical differences were found between curing units and thicknesses. In all experimental groups, the 0.5-mm-thick increments showed microhardness values statistically higher than those observed for 1- and -2-mm increments. The conventional and LED units showed higher hardness mean values and were statistically different from the high irradiance unit. In all experimental groups, microhardness mean values obtained for the top surface were higher than those observed for the bottom surface. In conclusion, higher levels of irradiance or thinner increments would help improve hybrid composite resin polymerization.Keywords: photo-polymerization, light-curing distance, light-curing units, composite resin, composite thickness, microhardness

  16. The Influence of the Thickness of the Slab and Concrete Grade on Composite Floors

    Directory of Open Access Journals (Sweden)

    Vasile-Mircea Venghiac

    2010-01-01

    Full Text Available A modern flooring system is the ComFloor Composite Floor Deck from Corus. This type of floor has many advantages involving cost, weight, construction speed, but also disadvantages regarding vibrations induced by human activity. The vibration behaviour of this system was analysed taking into consideration two parameters: the thickness of the slab and the grade of the concrete. Two sets of models were made, one with composite beams and one with steel beams. The purpose was to make a comparison between these two types of flooring systems. Results showed a good improvement created by the composite action of the beams and usefull information regarding the two parameters considered.

  17. Effect of composite/amalgam thickness on fracture resistance of maxillary premolar teeth, restored with combined amalgam-composite restorations

    Science.gov (United States)

    Firouzmandi, Maryam; Doozandeh, Maryam; Abbasi, Sanaz

    2016-01-01

    Background Combined amalgam-composite restorations have been used through many years to benefit from the advantages of both dental amalgam and composite resin. Two variations have been mentioned for this technique, this study investigated the fracture resistance of maxillary premolar teeth with extended mesio-occluso-distal (MOD) cavities, restored with the two variations of combined amalgam-composite restorations. Material and Methods Sixty intact extracted premolar teeth were randomly divided into 6 groups (G1-G6) of 10 teeth. G1; consisted of intact teeth and G2; consisted of teeth with MOD preparations were assigned as the positive and negative control groups respectively. Other experimental groups after MOD preparations were as follows: G3, amalgam restoration; G4, composite restoration; G5 combined amalgam-composite restoration with amalgam placement only on 1mm of the gingival floor of the proximal boxes; G6, combined amalgam-composite restoration with amalgam placement to the height of contact area of the proximal surface of the tooth. Fracture strength of the specimens was measured and the data were analyzed using one-way analysis of variance (ANOVA). The level of significance was Pamalgam-composite restoration was similar to that achieved with composite restoration alone and more than that of amalgam restoration alone. It can be concluded that the thickness of amalgam in combined amalgam-composite restorations did not affect fracture resistance of the teeth. Key words:Amalgam, composite, fracture resistance, restoration. PMID:27398176

  18. Estimate of the changes in the characteristics of a PZT vibrator under a space environment

    Science.gov (United States)

    Kim, Jungsoon; Lee, Sanghoon; Kim, Moojoon

    2015-03-01

    To utilize lead zirconate titanate (PZT) vibrators in the aerospace industry, we formulate the changes in the characteristics of the vibrator for the transverse mode and the thickness mode as functions of the temperature. For practical use, we adopted a few linear functions and a square function as regression functions in order to estimate the characteristics of the commercialized PZT-5 series of ceramics. The input admittance characteristics were calculated using the characteristic functions suggested in this study, and the results showed good agreement with the measured ones.

  19. Optical properties of PZT thin films deposited on a ZnO buffer layer

    OpenAIRE

    Schneider, T.; Leduc, D; Cardin, J.; LUPI, C; Barreau, N; Gundel, H.

    2007-01-01

    International audience; The optical properties of lead zirconate titanate (PZT) thin films deposited on ZnO were studied by m-lines spectroscopy. In order to retrieve the refractive index and the thickness of both layers from the m-lines spectra, we develop a numerical algorithm for the case of a two-layer system and show its robustness in the presence of noise. The sensitivity of the algorithm of the two-layer model allows us to relate the observed changes in the PZT refractive index to the ...

  20. Influence of the polymeric coating thickness on the electrochemical performance of Carbon Fiber/PAni composites

    Directory of Open Access Journals (Sweden)

    Carla Polo Fonseca

    2015-10-01

    Full Text Available Abstract Carbon fiber/polyaniline composites (CF/PAni were synthesized at three different deposition time of 30, 60 and 90 min by oxidative polymerization. The composite materials were morphologically and physically characterized by scanning electron microscopy and by Raman spectroscopy, respectively. Their electrochemical responses were analyzed by cyclic voltammetry, by galvanostatic test, and by electrochemical impedance spectroscopy. The influence of the PAni layer thickness deposited on carbon fibers for the composite formation as well as for their electrochemical properties was discussed. The CF/PAni-30 showed a nanometric thickness with more homogeneous morphology compared to those formed in deposition times of 60 and 90 min. It also showed, from the electrochemical impedance spectroscopy measurements, the lowest charge transfer resistance value associated to the its highest value for the double-layer capacitance of 180 Fg-1 making it a very strong candidate as a supercapacitor electrode.

  1. X-ray Fluorescence Spectroscopy Study of Coating Thickness and Base Metal Composition

    Science.gov (United States)

    Rolin, T. D.; Leszczuk, Y.

    2008-01-01

    For electrical, electronic, and electromechanical (EEE) parts to be approved for space use, they must be able to meet safety standards approved by NASA. A fast, reliable, and precise method is needed to make sure these standards are met. Many EEE parts are coated in gold (Au) and nickel (Ni), and the thickness coating is crucial to a part s performance. A nondestructive method that is efficient in measuring coating thickness is x-ray fluorescence (XRF) spectroscopy. The XRF spectrometer is a machine designed to measure layer thickness and composition of single or multilayered samples. By understanding the limitations in the collection of the data by this method, accurate composition and thickness measurements can be obtained for samples with Au and Ni coatings. To understand the limitations of data found, measurements were taken with the XRF spectrometer and compared to true values of standard reference materials (SRM) that were National Institute of Standards and Technology (NIST) traceable. For every sample, six different parameters were varied to understand measurement error: coating/substrate combination, number of layers, counting interval, collimator size, coating thickness, and test area location. Each measurement was taken in accordance with standards set by the American Society for Testing and Materials (ASTM) International Standard B 568.

  2. Influence of light curing and sample thickness on microhardness of a composite resin.

    Science.gov (United States)

    Aguiar, Flávio Hb; Andrade, Kelly Rm; Leite Lima, Débora An; Ambrosano, Gláucia Mb; Lovadino, José R

    2009-01-01

    The aim of this in vitro study was to evaluate the influence of light-curing units and different sample thicknesses on the microhardness of a composite resin. Composite resin specimens were randomly prepared and assigned to nine experimental groups (n = 5): considering three light-curing units (conventional quartz tungsten halogen [QTH]: 550 mW/cm(2) - 20 s; high irradiance QTH: 1160 mW/cm(2) - 10 s; and light-emitting diode [LED]: 360 mW/cm(2) - 40 s) and three sample thicknesses (0.5 mm, 1 mm, and 2 mm). All samples were polymerized with the light tip 8 mm away from the specimen. Knoop microhardness was then measured on the top and bottom surfaces of each sample. The top surfaces, with some exceptions, were almost similar; however, in relation to the bottom surfaces, statistical differences were found between curing units and thicknesses. In all experimental groups, the 0.5-mm-thick increments showed microhardness values statistically higher than those observed for 1- and -2-mm increments. The conventional and LED units showed higher hardness mean values and were statistically different from the high irradiance unit. In all experimental groups, microhardness mean values obtained for the top surface were higher than those observed for the bottom surface. In conclusion, higher levels of irradiance or thinner increments would help improve hybrid composite resin polymerization.

  3. THE MONOCLINIC PHASE IN PZT: NEW LIGHT ON MORPHOTROPIC PHASE BOUNDARIES

    Energy Technology Data Exchange (ETDEWEB)

    NOHEDA,B.; GONZALO,J.A.; GUO,R.; PARK,S.E.; CROSS,L.E.; COX,D.E.; SHIRANE,G.

    2000-03-09

    A summary of the work recently carried out on the morphotropic phase boundary (MPB) of PZT is presented. By means of x-ray powder diffraction on ceramic samples of excellent quality, the MPB has been successfully characterized by changing temperature in a series of closely spaced compositions. As a result, an unexpected monoclinic phase has been found to exist in between the well-known tetragonal and rhombohedral PZT phases. A detailed structural analysis, together with the investigation of the field effect in this region of compositions, have led to an important advance in understanding the mechanisms responsible for the physical properties of PZT as well as other piezoelectric materials with similar morphotropic phase boundaries.

  4. Large electric-field control of perpendicular magnetic anisotropy in strained [Co/Ni] / PZT heterostructures

    Science.gov (United States)

    Gopman, Daniel; Dennis, Cindi; Chen, P. J.; Iunin, Yury; Shull, Robert

    We present a piezoelectric/ferromagnetic heterostructure with PMA - a Co/Ni multilayer sputtered directly onto a Pb(Zr,Ti)O3 (PZT) substrate. Chemical-mechanical polishing was used to reduce the roughness of PZT plates to below 2 nm rms, enabling optimal magnetoelectric coupling via the direct interface between PZT and sputtered Co/Ni films with large PMA (Keff = (95 +/-9 kJ/m3)) . We grew the following layer stack: Ta(3)/Pt(2)/[Co(0.15)/Ni(0.6)]x4/Co(0.15)/Pt(2)/Ta(3); numbers in parentheses indicate thicknesses in nm. Applied electric fields up to +/- 2 MV/m to the PZT generated 0.05% in-plane compression in the Co/Ni multilayer, enabling a large electric-field reduction of the PMA (ΔKeff >= 103 J/m3) and of the coercive field (35%). Our results demonstrate that: (i) heterostructures combining PZT and [Co/Ni] exhibit larger PMA (Keff ~105 J/m3) than previous magnetoelectric heterostructures based on Co/Pt and CoFeB, enabling thermally stable hybrid magnetoelectric/spintronic devices only tens of nm in diameter and (ii) electric-field control of the PMA is promising for more energy efficient switching of spintronic devices.

  5. Impact of paint matrix composition and thickness of paint layer on the activity of photocatalytic paints

    Directory of Open Access Journals (Sweden)

    Homa Piotr

    2017-03-01

    Full Text Available Silicate, acrylic and latex photocatalytic paints were analyzed in regards to impact of paint matrix composition and paint layer’s thickness on performance in two photocatalytic tests. These included performances in photocatalytic decomposition of benzo[a]pyrene (BaP and assessment of photocatalytic activity through use of smart ink test. Silicate photocatalytic paints displayed lower photocatalytic activity in comparison to acrylic and latex photocatalytic paints in both tests, despite the similar content of nanocrystalline TiO2. Measurements of depth of UV light penetration through the paints layer were performed and it appeared, that more porous structure of coating resulted in deeper penetration of UV light. In the case of acrylic paint, the thickness of the photocatalytic layer was around 9 μm, but for silicate paint DR this thickness was higher, around 21 μm.

  6. Study of dynamic pressure roadway supporting scheme under condition of thick composite roof

    Institute of Scientific and Technical Information of China (English)

    Wei-Jun WANG; Li-Qiang LUO; Wei-Jian YU; Hai WU; Yan-Si QU

    2013-01-01

    This paper analyzed the strata behaviors of solid-coal roadway,gob-side entry driving and deformation law of surrounding rock in depth under high stress and thick composite roof based on the dynamic pressure roadway as engineering background in Fengcheng mining area,Jiangxi province.The results,both field measurement andnumerical simulation show that gob-side entry driving results the deformation of coal roadway main wall,however,entity-coal roadway driving results deformation of main roof and floor.The maintenance state of gob-side entry driving is better than entity-coal roadway,this situation is relevant to thick composite roof layered and easy collapse characteristics.At the same time,this paper put forward and proved proper dynamic pressure roadway supporting scheme under the surrounding rock condition and stress environment.

  7. Background interference on the color of dental composite materials with different thickness by digital contrast

    Science.gov (United States)

    Lins, Emery C.; Florez, Fernando L. E.; Portero, Priscila P.; Lizarelli, Rozane F. Z.; Oliveira, Osmir B., Jr.; Bagnato, Vanderlei S.

    2007-02-01

    In this work the color dependence of resin composites with the background color was evaluated. The objective was to measure since what thickness the color of the sample stops being influenced by the color of the background over which the resin is placed and the methodology used in experiment was based in analyzing the contrast of digital images of the sample over a black background. The results shown that since 0.8 mm the images contrast becomes almost constant; it prove that since this thickness the color of resin composite depends on the optical resin properties only. The experiment was repeated under three conditions of luminosity to evaluate the influence of it on the image contrast and the results obtained were identical.

  8. Multi-Material and Thickness Optimization Utilizing Casting Filters for Laminated Composite Structures

    DEFF Research Database (Denmark)

    Sørensen, Rene; Lund, Erik

    2013-01-01

    This extended abstract presents a new parameterization for performing discrete material and thickness optimization of laminated composite structures. The parameterization is based on the work by Sørensen and Lund 2013, where we present a reformulation of the original parameterization. The reformu......This extended abstract presents a new parameterization for performing discrete material and thickness optimization of laminated composite structures. The parameterization is based on the work by Sørensen and Lund 2013, where we present a reformulation of the original parameterization....... The reformulation eliminates the need for having explicit constraint for ensuring that intermediate void does not appear in between layers of the laminate. This is achieved by utilizing a filtering technique known as a casting constraint from traditional topology optimization with isotropic materials....

  9. Determination of the effective atomic number of thick samples of unknown composition using scattering studies

    Science.gov (United States)

    Sankarshan, B. M.; Athrey, C. D.; Umesh, T. K.

    2017-06-01

    The effective atomic number ( Z_eff is a quantity which gives the fraction of the total number of electrons in a composite material participating in the photon-atom interaction. The effective atomic number has been determined for the materials of known composition by using different methods. However, no method has been reported so far to determine Z_eff for thick samples of unknown composition. In view of this, we have evolved a simple method to determine the effective atomic number, which uses the scattering intensity ratios measured at two scattering angles, in which a sample of known Z_eff or Z is taken as a reference sample. The values of Z_eff obtained by this method agree with those obtained from the Auto-Zeff software within the stated errors. This method could be helpful in determining the effective atomic number of samples of unknown composition.

  10. Revised Thickness of the Lunar Crust from GRAIL Data: Implications for Lunar Bulk Composition

    Science.gov (United States)

    Taylor, G. Jeffrey; Wieczorek, Mark A.; Neumann, Gregory A.; Nimmo, Francis; Kiefer, Walter S.; Melosh, H. Jay; Phillips, Roger J.; Solomon, Sean C.; Andrews-Hanna, Jeffrey C.; Asmar, Sami W.; Konopliv, Alexander S.; Lemoine, Frank G.; Smith, David E.; Watkins, Michael W.; Williams, James G.; Zuber, Maria T.

    2013-01-01

    High-resolution gravity data from GRAIL have yielded new estimates of the bulk density and thickness of the lunar crust. The bulk density of the highlands crust is 2550 kg m-3. From a comparison with crustal composition measured remotely, this density implies a mean porosity of 12%. With this bulk density and constraints from the Apollo seismic experiment, the average global crustal thickness is found to lie between 34 and 43 km, a value 10 to 20 km less than several previous estimates. Crustal thickness is a central parameter in estimating bulk lunar composition. Estimates of the concentrations of refractory elements in the Moon from heat flow, remote sensing and sample data, and geophysical data fall into two categories: those with refractory element abundances enriched by 50% or more relative to Earth, and those with abundances the same as Earth. Settling this issue has implications for processes operating during lunar formation. The crustal thickness resulting from analysis of GRAIL data is less than several previous estimates. We show here that a refractory-enriched Moon is not required

  11. Investigation of Fiber Waviness in a Thick Glass Composite Beam Using THz NDE

    Science.gov (United States)

    Anastasi, Robert F.

    2008-01-01

    Fiber waviness in laminated composite material is introduced during manufacture because of uneven curing, resin shrinkage, or ply buckling caused by bending the composite lay-up into its final shape prior to curing. The resulting waviness has a detrimental effect on mechanical properties, therefore this condition is important to detect and characterize. Ultrasonic characterization methods are difficult to interpret because elastic wave propagation is highly dependent on ply orientation and material stresses. By comparison, the pulsed terahertz response of the composite is shown to provide clear indications of the fiber waviness. Pulsed Terahertz NDE is an electromagnetic inspection method that operates in the frequency range between 300 GHz and 3 THz. Its propagation is influenced by refractive index variations and interfaces. This work applies pulsed Terahertz NDE to the inspection of a thick composite beam with fiber waviness. The sample is a laminated glass composite material approximately 15mm thick with a 90-degree bend. Terahertz response from the planar section, away from the bend, is indicative of a homogeneous material with no major reflections from internal plies, while the multiple reflections at the bend area correspond to the fiber waviness. Results of these measurements are presented for the planar and bend areas.

  12. DMTO – a method for Discrete Material and Thickness Optimization of laminated composite structures

    DEFF Research Database (Denmark)

    Sørensen, Søren Nørgaard; Sørensen, Rene; Lund, Erik

    2014-01-01

    are optimized simultaneously through interpolation functions with penalization. Numerical results for several parameterizations of a finite element model of a generic main spar from a wind turbine blade are presented. The different parameterizations represent different levels of complexity with respect......This paper presents a gradient based topology optimization method for Discrete Material and Thickness Optimization of laminated composite structures, labelled the DMTOmethod. The capabilities of the proposed method are demonstrated on mass minimization, subject to constraints on the structural...

  13. Reticular basement membrane in asthma and COPD: Similar thickness, yet different composition

    Directory of Open Access Journals (Sweden)

    Jeroen JW Liesker

    2009-02-01

    Full Text Available Jeroen JW Liesker1, Nick H Ten Hacken1, Mieke Zeinstra-Smith2, Steven R Rutgers1, Dirkje S Postma1, Wim Timens21Department of Pulmonology; 2Department of Pathology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands Background: Reticular basement membrane (RBM thickening has been variably associated with asthma and chronic obstructive pulmonary disease (COPD. Even if RBM thickness is similar in both diseases, its composition might still differ. Objective: To assess whether RBM thickness and composition differ between asthma and COPD. Methods: We investigated 24 allergic asthmatics (forced expiratory volume in one second [FEV1] 92% predicted, and 17 nonallergic COPD patients (FEV1 60% predicted, and for each group a control group of similar age and smoking habits (12 and 10 persons, respectively. Snap-frozen sections of bronchial biopsies were stained with hematoxylin/eosin and for collagen I, III, IV, V, laminin and tenascin. RBM thickening was assessed by digital image analysis. Relative staining intensity of each matrix component was determined.Results: Mean (SD RBM thickness was not significantly different between asthma and COPD 5.5 (1.3 vs 6.0 (1.8 μm, but significantly larger than in their healthy counterparts, ie, 4.7 (0.9 and 4.8 (1.2 μm, respectively. Collagen I and laminin stained significantly stronger in asthma than in COPD. Tenascin stained stronger in asthma than in healthy controls of similar age, and stronger in COPD controls than in asthma controls (p 0.05.Conclusion: RBM thickening occurs both in asthma and COPD. We provide supportive evidence that its composition differs in asthma and COPD. Keywords: reticular basement membrane thickness, reticular basement membrane composition, asthma, biopsy, COPD, remodeling

  14. Microhardness of different thicknesses of resin composite polymerized by conventional photocuring at different distances.

    Science.gov (United States)

    Aguirar, Flavio Henrique Baggio; e Oliveria, Thalita Regina Viera; Lima, Debora Alves Nunes Leite; Ambrosano, Glaucia maria ovi; Lovadino, Jose Roberto

    2008-01-01

    This in vitro study sought to evaluate the influence of photocuring modes and polymerization time on the microhardness of a hybrid composite resin. Sixty composite resin specimens were prepared at random and divided into 12 experimental groups (n=5), consisting of four curing tip distances (2.0 mm, 4.0 mm, 6.0 mm, and 8.0 mm) and three sample thicknesses (0.5 mm, 1.0 mm, and 2.0 mm). All samples were polymerized with a continuous output at 550 mW/cm2. After 24 hours, Knoop microhardness measurements were obtained on top and bottom surfaces of the sample, with a load of 25 g for 10 seconds. Five indentations were made on each surface of each sample. Subdivided parcels ANOVA test and Tukey test were performed (p = 0.05). There were no statistical differences among the experimental groups for the top surface. On the bottom surface, 0.5 mm and 1.0 mm sample thicknesses showed significantly higher hardness means for all photocuring tip distances when compared with the 2.0 mm sample thickness. In terms of the photocuring tip distance, the 2.0 mm and 4.0 mm distances showed significantly higher hardness means for all sample thicknesses when compared with the 8.0 mm distance. For all experimental conditions, the top surface showed higher hardness than the bottom surface. It was concluded that the resin composite increments should be decreased to improve the polymerization of the resin composite bottom surface in deep cavities.

  15. Thickness optimization of laminated composites using the discrete material optimization method

    DEFF Research Database (Denmark)

    Sørensen, Søren Nørgaard; Sørensen, Rene; Lund, Erik

    2012-01-01

    This work concerns a novel large scale multi-material topology optimization method for simultaneous determination of the optimum variable integer thickness and fiber orientation throughout laminated composites with fixed outer geometries while adhering to certain manufacturing constraints....... The conceptual combinatorial/integer problem is relaxed to a continuous problem and solved on basis of the so-called Discrete Material Optimization method, explicitly including the manufacturing constraints as linear constraints....

  16. [Validation by hydrodensitometry of skinfold thickness equations used for female body composition assessment].

    Science.gov (United States)

    Aristizábal, Juan Carlos; Restrepo, María Teresa; Amalia, López

    2008-09-01

    Introduction. Skinfold thickness equations are widely used for body composition assessment. However the equations have not been validated in Colombia with a reference method. Objective. The skinfold thickness equations of Durning/Womersley, Jackson/Pollock and Ramírez/Torun were validated by hydrodensitometry in female from 18 to 40 years old. Materials and methods. The percentage of body fat was compared among 52 women, using underwater weighing (Chatillon scale) with simultaneous measured of residual lung volume (VMAX 22 Sensormedics spirometer) and skinfold thickness (Harpenden caliper) equations of Durning/Womersley, Jackson/Pollock and Ramírez/Torun. The statistic analysis included paired t test, Pearson and intraclass correlation coefficients, and the Bland-Altman method. Results. The mean percentage of body fat by hydrodensitometry (29.6+/-5.8%) was different (p Conclusion. The skinfold thickness equations showed poor validity for body fat assessment. The equations had significant differences and lower correlation coefficients with hydrodensitometry. In addition, the equations indicated agreement with hydrodensitometry over very wide limits. The outcomes suggested that the results obtained by hydrodensitometry were neither comparable nor interchangeable with those from Durning/Womersley, Jackson/Pollock y Ramírez/Torun skinfold thickness equations.

  17. Microwave sintering of sol-gel composite films using a domestic microwave oven

    Science.gov (United States)

    Kobayashi, Makiko; Matsumoto, Makoto

    2016-07-01

    Feasibility study of sol-gel composite microwave sintering using a domestic microwave oven was carried out. Two kinds of lead zirconate titanate (PZT) powders were mixed with PZT sol-gel solution and the mixture was sprayed onto 3-mm-thick titanium substrate. The films were sintered by 700 W domestic oven for 10 min. Ultrasonic measurement was carried out in pulse-echo mode and clear multiple echoes were confirmed. It would be suitable method to fabricate high frequency broadband focused ultrasonic transducers. Further research is required to improve sintering degree.

  18. Design and Experiment of PZT Network-based Structural Health Monitoring Scanning System

    Institute of Scientific and Technical Information of China (English)

    Qiu Lei; Yuan Shenfang; Wang Qiang; Sun Yajie; Yang Weiwei

    2009-01-01

    The active Lamb wave and piezoelectric transducer (PZT)-based structural health monitoring (SHM) technology is a kind of efficient approach to estimate the health state of aircraft structure. In practical applications, PZT networks are needed to monitor large scale structures. Scanning many of the different PZT actuator-sensor channels within these PZT networks to achieve on-line SHM task is important. Based on a peripheral component interconnect extensions for instrumentation (PXI) platform, an active Lamb wave and PZT network-based integrated multi-channel scanning system (PXI-ISS) is developed for the purpose of practical applications of SHM, which is compact and portable, and can scan large numbers of actuator-sensor channels and perform damage assessing automatically. A PXI-based 4 channels gain-programmable charge amplifier, an external scanning module with 276 actuator-sensor channels and integrated SHM software are proposed and discussed in detail. The experimental research on a carbon fiber composite wing box of an unmanned aerial vehicle (UAV) for verifying the functions of the PXI-ISS is mainly discussed, including the design of PZTs layer, the method of excitation frequency selection, functional test of damage imaging, stability test of the PXI-ISS, and the loading effect on signals. The experimental results have verified the stability and damage functions of this system.

  19. Smart Energy Materials of PZT Ceramics

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Okayasu

    2017-03-01

    Full Text Available To better understand the material properties of lead zirconate titanate (PZT ceramics, the domain-switching characteristics and electric power generation characteristics have been investigated during loading and unloading by using various experimental techniques. Furthermore, the influence of oscillation condition on the electrical power generation properties of lead zirconate titanate (PZT piezoelectric ceramics has been investigated. It is found that the power generation is directly attributed to the applied load and wave mode. The voltage rises instantly to the maximum level under square-wave mode, although the voltage increases gradually under triangular-wave mode. After this initial increase, there is a rapid fall to zero, followed by generation of increasingly negative voltage as the applied load is removed for all wave modes. Variation of the electric voltage is reflected by the cyclic loading at higher loading frequencies. On the basis of the obtained experimental results for the wave modes, the electrical power generation characteristics of PZT ceramics are proposed, and the voltages generated during loading and unloading are accurately estimated. The electric generation value is decrease with increasing the cyclic number due to the material failure, e.g., domain switching and crack. The influence of domain switching on the mechanical properties PZT piezoelectric ceramics is clarified, and 90 degree domain switching occurs after the load is applied to the PZT ceramic directly. Note that, in this paper, our experimental results obtained in our previous works were introduced

  20. Liquid Density Sensing Using Resonant Flexural Plate Wave Device with Sol-Gel PZT Thin Films

    CERN Document Server

    Yu, Jyh-Cheng

    2008-01-01

    This paper presents the design, fabrication and preliminary experimental results of a flexure plate wave (FPW) resonator using sol-gel derived lead zirconate titanates (PZT) thin films. The resonator adopts a two-port structure with reflecting grates on the composite membrane of PZT and SiNx. The design of the reflecting grate is derived from a SAW resonator model using COM theory to produce a sharp resonant peak. The comparison between the mass and the viscosity effects from the theoretical expression illustrates the applications and the constraints of the proposed device in liquid sensing. Multiple coatings of sol-gel derived PZT films are adopted because of the cost advantage and the high electromechanical coupling effect over other piezoelectric films. The fabrication issues of the proposed material structure are addressed. Theoretical estimations of the mass and the viscosity effects are compared with the experimental results. The resonant frequency has a good linear correlation with the density of low v...

  1. Design and fabrication of aspherical bimorph PZT optics

    CERN Document Server

    Tseng, T C; Yeh, Z C; Perng, S Y; Wang, D J; Kuan, C K; Chen, J R; Chen, C T

    2001-01-01

    Bimorph piezoelectric optics with a third-order-polynomial surface is designed and a prototype is fabricated as active optics. Two pairs of silicon (Si) and lead zirconate titanate (PZT) piezoelectric ceramic are bonded as Si-PZT-PZT-Si together with a multi-electrode or thin film resistor coating used as the control electrode between Si and PZT and metallic films as grounding between the interface of PZT ceramics. A linear voltage is applied to the bimorph PZT optics by probing the control electrodes from a two-channel controllable power supplier. In doing so, the optics surface can achieve a desired third-order-polynomial surface. Reducing hysteresis and creep in bimorph PZT X-ray optics is the only feasible way by inserting an appropriate capacitor in series with bimorph PZT optics to significantly reduce both effects.

  2. The effect of resin thickness on polymerization characteristics of silorane-based composite resin

    Directory of Open Access Journals (Sweden)

    Sung-Ae Son

    2014-11-01

    Full Text Available Objectives This study examined the influence of the resin thickness on the polymerization of silorane- and methacrylate-based composites. Materials and Methods One silorane-based (Filtek P90, 3M ESPE and two methacrylate-based (Filtek Z250 and Z350, 3M ESPE composite resins were used. The number of photons were detected using a photodiode detector at the different thicknesses (thickness, 1, 2 and 3 mm specimens. The microhardness of the top and bottom surfaces was measured (n = 15 using a Vickers hardness with 200 gf load and 15 sec dwell time conditions. The degree of conversion (DC of the specimens was determined using Fourier transform infrared spectroscopy (FTIR. Scratched powder of each top and bottom surface of the specimen dissolved in ethanol for transmission FTIR spectroscopy. The refractive index was measured using a Abbe-type refractometer. To measure the polymerization shrinkage, a linometer was used. The results were analyzed using two-way ANOVA and Tukey's test at p < 0.05 level. Results The silorane-based resin composite showed the lowest filler content and light attenuation among the specimens. P90 showed the highest values in the DC and the lowest microhardness at all depth. In the polymerization shrinkage, P90 showed a significantly lower shrinkage than the rest two resin products (p < 0.05. P90 showed a significantly lower refractive index than the remaining two resin products (p < 0.05. Conclusions DC, microhardness, polymerization rate and refractive index linearly decreased as specimen thickness linearly increased. P90 showed much less polymerization shrinkage compared to other specimens. P90, even though achieved the highest DC, showed the lowest microhardness and refractive index.

  3. Study on Effect of Thickness and Fibre Orientation on a Tensile and Flexural Properties of a Hybrid Composite

    Directory of Open Access Journals (Sweden)

    Mr. Santhosh Kumar. M

    2014-08-01

    Full Text Available This project presents the study of tensile, flexural & moisture absorption properties of composites made from S-glass, Carbon and E-glass fibre. The specimens are prepared using hand lay-up techniques as per ASTM standard for different thickness 2mm and 3mm and fibre orientation of 30º, 45º and 60º, where an attempt is made to study the properties of composite materials by composing the different materials together to obtain the desired properties by increasing the thickness and fibre orientation. By the variation of thickness tensile strength of hybrid composite is observed for each thickness and is compared with the finite element analysis results. The test ready specimens were subjected to tensile and flexural loads on UTM. This research indicates that tensile strength is mainly dependent on the fiber orientation & thickness of laminated polymer composites. The moisture absorption increases with the fibre, filler content and duration of immersion in water.

  4. Experimental investigation of effect of specimen thickness on fracture toughness of Al-TiC composites

    Directory of Open Access Journals (Sweden)

    M. S. Raviraj

    2016-07-01

    Full Text Available In this paper, the macro and micro-mechanical fracture behavior was studied for aluminum (Al6061 alloy matrix, reinforced with various proportions of TiC particles such as 3wt%, 5wt% and 7wt%. The Al6061-TiC metal matrix composites were produced by stir casting method to ensure uniform distribution of the TiC particulates in the Al matrix. The compact tension (CT specimens were machined according to ASTM E399 specifications to evaluate the fracture toughness for Al6061-TiC metal matrix composites. The CT specimens were machined for crack to width (a/W ratio of 0.5 and thickness to width (B/W ratios of 0.2 to 0.7 with an increment of 0.1. Load versus crack mouth opening displacement (CMOD data was plotted to estimate stress intensity factor KQ for various thicknesses of the specimen. The fracture toughness KIC was obtained by plotting stress intensity factor versus thickness to width ratios of specimen data. The fracture toughness of these composites varied between 16.4-19.2 MPa√m. Scanning Electron Microscope (SEM studies was made on the fractured surface of the specimens to understand the micro-mechanisms of failure involved in these composites. Void initiation is more significant in the matrix near the interface. The micro-cracks grow from these micro-voids and crack propagates by linking these micro cracks locating the crack path preferentially in the matrix adjacent to the interface indicating ductile fracture.

  5. Ultrathin magnesia films as support for molecules and metal clusters: Tuning reactivity by thickness and composition

    Energy Technology Data Exchange (ETDEWEB)

    Vaida, Mihai E.; Bernhardt, Thorsten M. [Institute of Surface Chemistry and Catalysis, University of Ulm (Germany); Barth, Clemens [CINAM-CNRS, Marseille (France); Esch, Friedrich; Heiz, Ueli [Department of Chemistry, Technical University of Munich, Garching (Germany); Landman, Uzi [School of Physics, Georgia Institute of Technology, Atlanta, Georgia (United States)

    2010-05-15

    Ultrathin metal oxide films have attracted considerable interest in recent years as versatile substrate for the design of nanocatalytic model systems. In particular, it has been proposed theoretically and confirmed experimentally that the electronic structure of adsorbates can be influenced by the layer thickness and the stoichiometry, i.e., the type and number of defects, of the oxide film. This has important consequences on the chemical reactivity of the oxide surface itself and of oxide supported metal clusters. It also opens new possibilities to influence and to control chemical reactions occurring at the surface of these systems. The present feature focuses on very recent experiments that illustrate the effects of a proper adjustment of layer thickness and composition of ultrathin MgO(100) films on chemical transformations. On the magnesia surface itself, the photodissociation dynamics of methyl iodide molecules is investigated via femtosecond-laser pump-probe mass spectrometry. Furthermore, the catalytic oxidation of carbon monoxide at mass-selected Au{sub 20} clusters deposited on magnesia is explored through temperature programmed reaction measurements. In the latter case, detailed first principles calculations are able to correlate the experimentally observed reactivity with structural dimensionality changes that are induced by the changing thickness and composition of the magnesia support. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  6. Theoretical models to predict the mechanical behavior of thick composite tubes

    Directory of Open Access Journals (Sweden)

    Volnei Tita

    2012-02-01

    Full Text Available This paper shows theoretical models (analytical formulations to predict the mechanical behavior of thick composite tubes and how some parameters can influence this behavior. Thus, firstly, it was developed the analytical formulations for a pressurized tube made of composite material with a single thick ply and only one lamination angle. For this case, the stress distribution and the displacement fields are investigated as function of different lamination angles and reinforcement volume fractions. The results obtained by the theoretical model are physic consistent and coherent with the literature information. After that, the previous formulations are extended in order to predict the mechanical behavior of a thick laminated tube. Both analytical formulations are implemented as a computational tool via Matlab code. The results obtained by the computational tool are compared to the finite element analyses, and the stress distribution is considered coherent. Moreover, the engineering computational tool is used to perform failure analysis, using different types of failure criteria, which identifies the damaged ply and the mode of failure.

  7. Assessment of skinfold thickness equations in estimating body composition in children with inflammatory bowel disease.

    Science.gov (United States)

    Callias, Céline; Ezri, Jessica; Marques-Vidal, Pedro Manuel; Nydegger, Andreas

    2016-05-01

    To assess the agreement of commonly used skinfold thickness equations to estimate percentage of Fat Mass (FM%) in paediatric patients with IBD, in comparison with dual energy X-ray absorptiometry (DEXA). Twenty-one paediatric IBD patients were included: 11 females and 10 males; mean age for the entire group: 14.3 years, range 12-16 years, 16 with Crohn's disease, five with ulcerative colitis. The FM% was calculated using six established paediatric skinfold thickness equations and compared to the results obtained by DEXA. The statistical analysis was performed using Spearman's correlation, Lin's concordance correlation coefficient and corresponding 95% confidence interval, Bland-Altman's limits of agreement method and the Bradley-Blackwood test. Correlation between skinfold and DEXA values ranged between 0.85 (Deurenberg) and 0.92 (Durnin and Rahaman and Johnston), all P skinfold and DEXA values ranged between -3.6% (Deurenberg) and 2.5% (Weststrate). Bland-Altman limits of agreement were wide, spanning over 10%. Finally, the Bradley-Blackwood test of equality of means and variances was significant in all but the Durnin and Rahaman equation. In adolescents with IBD, fat mass calculated from six skinfold thickness equations showed good correlation but poor agreement with reference values from DEXA. Assessment of body composition using skinfold thickness equations cannot be recommended in paediatric patients with IBD. © 2016 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

  8. Effect of ceramic thickness and composite bases on stress distribution of inlays--a finite element analysis.

    Science.gov (United States)

    Durand, Letícia Brandão; Guimarães, Jackeline Coutinho; Monteiro Junior, Sylvio; Baratieri, Luiz Narciso

    2015-01-01

    The purpose of this study was to determine the effect of cavity depth, ceramic thickness, and resin bases with different elastic modulus on von Mises stress patterns of ceramic inlays. Tridimensional geometric models were developed with SolidWorks image software. The differences between the models were: depth of pulpal wall, ceramic thickness, and presence of composite bases with different thickness and elastic modulus. The geometric models were constrained at the proximal surfaces and base of maxillary bone. A load of 100 N was applied. The stress distribution pattern was analyzed with von Mises stress diagrams. The maximum von Mises stress values ranged from 176 MPa to 263 MPa and varied among the 3D-models. The highest von Mises stress value was found on models with 1-mm-thick composite resin base and 1-mm-thick ceramic inlay. Intermediate values (249-250 MPa) occurred on models with 2-mm-thick composite resin base and 1-mm-thick ceramic inlay and 1-mm-thick composite resin base and 2-mm-thick ceramic inlay. The lowest values were observed on models restored exclusively with ceramic inlay (176 MPa to 182 MPa). It was found that thicker inlays distribute stress more favorably and bases with low elastic modulus increase stress concentrations on the internal surface of the ceramic inlay. The increase of ceramic thickness tends to present more favorable stress distribution, especially when bonded directly onto the cavity without the use of supporting materials. When the use of a composite base is required, composite resin with high elastic modulus and reduced thickness should be preferred.

  9. Epoxy-photopolymer composites: thick recording media for holographic data storage

    Science.gov (United States)

    Trentler, Timothy J.; Boyd, Joel E.; Colvin, Vicki L.

    2001-06-01

    Archival data-storage based on holographic methods requires high performance recording materials. Here, we describe an epoxy-photopolymer composite material which is sensitive to visible light and can be fabricated as thick films. These materials are prepared by combining photopolymerizable vinyl monomers with a liquid epoxy resin and an amine hardener. As the epoxy cures at room temperature, a solid matrix is formed which surrounds the unreacted photopolymer. These vinyl monomers are subsequently photopolymerized during hologram recording. Typically the material consists of a low index matrix, composed of diethylenetriamine and 1,4- butanediol diglycidyl ether, and a high index photopolymer mixture of N-vinylcarbazole and N-vinyl-2-pyrrolidinone. Because the polymers can be prepared in thick formats, narrow angular bandwidth holograms with high diffraction efficiency can be recorded. A dynamic range up to 13 has been measured in these materials.

  10. Thick and hard anodized aluminum film with large pores for surface composites

    Institute of Scientific and Technical Information of China (English)

    WANG Hui; WANG Hao-wei

    2004-01-01

    Al-base surface self-lubricating composites need thick and hard alumina membranes with large pores to add lubricants easily. This kind of porous alumina layer was fabricated in additive-containing, phosphoric acid-based solution. The effects of additive containing organic carboxylic acid and Ce salt on the properties of the oxide film and mechanism were investigated in detail with SEM and EDAX analyses. The results show that the pore diameter is about 100 nm, the film thickness increases by 4 -5 times, and the Vickers hardness improves by about 50% through adding some amount of organic carboxylic acid and Ce salt. Such an improvement in properties is explained in terms of a lower film dissolving velocity and better film quality in compound solution.

  11. Flattening simulations of 3D thick sheets made of fiber composite materials

    Directory of Open Access Journals (Sweden)

    Kotaro Morioka

    2015-04-01

    Full Text Available Recently, fiber composite materials have been attracting attention from industry because of their remarkable material characteristics, including light weight and high stiffness. However, the costs of products composed of fiber materials remain high because of the lack of effective manufacturing and designing technologies. To improve the relevant design technology, this paper proposes a novel simulation method for deforming fiber materials. Specifically, given a 3D model with constant thickness and known fiber orientation, the proposed method simulates the deformation of a model made of thick fiber-material. The method separates a 3D sheet model into two surfaces and then flattens these surfaces into two dimensional planes by a parameterization method with involves cross vector fields. The cross vector fields are generated by propagating the given fiber orientations specified at several important points on the 3D model. Integration of the cross vector fields gives parameterization with low-stretch and low-distortion.

  12. DESIGN OF FILM THICKNESS INSTRUMENT FOR FIBRE POLYMER COMPOSITES TRIBOLOGICAL EXPERIMENTS

    Directory of Open Access Journals (Sweden)

    B. F. YOUSIF

    2014-04-01

    Full Text Available New technique to measure film thickness in tribological experiments is presented in the current study. The technique is based on strain gauges circuit fixed on a lever of the block on ring (BOR machine. Conversion of strain gauge readings was made to determine the film thickness values. For testing purposes, experiments were conducted using the new machine to investigate the wear performance of glass/polyester composites. The tests were performed against aluminium counterface at different applied loads (0.5 N to 3 N for 10 minutes sliding time under wet contact conditions. From the results, the new technique highly assisted to analysis the tribological results. The SEM showed different damage features.

  13. Structural and Electrical Properties of PZT/PVDF Piezoelectric Nanocomposites Prepared by Cold-Press and Hot-Press Routes

    Institute of Scientific and Technical Information of China (English)

    ZHANG De-Qing; WANG Da-Wei; YUAN Jie; ZHAO Quan-Liang; WANG Zhi-Ying; CAO Mao-Sheng

    2008-01-01

    @@ The 0-3 PZT/PVDF piezoelectric composites are prepared separately by hot-press and cold-press processes. The effects of the PZT content and the shaping-process on the composites are studied. The experimental results indicate that composites with 70% PZT nanopowders prepared by the hot-press method exhibit excellent piezo-electric and dielectric properties. The maxima of daa and e of the composites prepared by hot-press method are about 30% and 65% higher than those prepared by the cold-press method, respectively. This is mainly attributed to the favourable coupling of the two materials in the process of the hot press and the formation of the β-type PVDF, which possesses better electric properties.

  14. Multi-Material and Thickness Optimization Utilizing Casting Filters for Laminated Composite Structures

    DEFF Research Database (Denmark)

    Sørensen, Rene; Lund, Erik

    2013-01-01

    This extended abstract presents a new parameterization for performing discrete material and thickness optimization of laminated composite structures. The parameterization is based on the work by Sørensen and Lund 2013, where we present a reformulation of the original parameterization....... The reformulation eliminates the need for having explicit constraint for ensuring that intermediate void does not appear in between layers of the laminate. This is achieved by utilizing a filtering technique known as a casting constraint from traditional topology optimization with isotropic materials....

  15. Investigation of Through-Thickness Stresses in Composite Laminates Using Layerwise Theory

    Directory of Open Access Journals (Sweden)

    Hamidreza Yazdani Sarvestani

    2013-01-01

    Full Text Available In this study, an analytical method is developed to exactly obtain the interlaminar stresses near the free edges of laminated composite plates under the bending moment based on the reduced form of elasticity displacement field for a long laminate. The analytical and numerical studies were performed based on the Reddy’s layerwise theory for the boundary layer stresses within cross-ply, symmetric, angle-ply, and general composite laminates. Finally, a variety of numerical results are presented for the interlaminar normal and shear stresses along the interfaces and through thickness of laminates near the free edges. The results showed high stress gradient of interlaminar normal and shear stresses near the edges of laminates.

  16. Flexible graphene-PZT ferroelectric nonvolatile memory

    Science.gov (United States)

    Lee, Wonho; Kahya, Orhan; Tat Toh, Chee; Özyilmaz, Barbaros; Ahn, Jong-Hyun

    2013-11-01

    We report the fabrication of a flexible graphene-based nonvolatile memory device using Pb(Zr0.35,Ti0.65)O3 (PZT) as the ferroelectric material. The graphene and PZT ferroelectric layers were deposited using chemical vapor deposition and sol-gel methods, respectively. Such PZT films show a high remnant polarization (Pr) of 30 μC cm-2 and a coercive voltage (Vc) of 3.5 V under a voltage loop over ±11 V. The graphene-PZT ferroelectric nonvolatile memory on a plastic substrate displayed an on/off current ratio of 6.7, a memory window of 6 V and reliable operation. In addition, the device showed one order of magnitude lower operation voltage range than organic-based ferroelectric nonvolatile memory after removing the anti-ferroelectric behavior incorporating an electrolyte solution. The devices showed robust operation in bent states of bending radii up to 9 mm and in cycling tests of 200 times. The devices exhibited remarkable mechanical properties and were readily integrated with plastic substrates for the production of flexible circuits.

  17. Bandgap Engineering of InP QDs Through Shell Thickness and Composition

    Energy Technology Data Exchange (ETDEWEB)

    Dennis, Allison M. [Los Alamos National Laboratory; Mangum, Benjamin D. [Los Alamos National Laboratory; Piryatinski, Andrei [Los Alamos National Laboratory; Park, Young-Shin [Los Alamos National Laboratory; Htoon, Han [Los Alamos National Laboratory; Hollingsworth, Jennifer A. [Los Alamos National Laboratory

    2012-06-21

    Fields as diverse as biological imaging and telecommunications utilize the unique photophysical and electronic properties of nanocrystal quantum dots (NQDs). The development of new NQD compositions promises material properties optimized for specific applications, while addressing material toxicity. Indium phosphide (InP) offers a 'green' alternative to the traditional cadmium-based NQDs, but suffers from extreme susceptibility to oxidation. Coating InP cores with more stable shell materials significantly improves nanocrystal resistance to oxidation and photostability. We have investigated several new InP-based core-shell compositions, correlating our results with theoretical predictions of their optical and electronic properties. Specifically, we can tailor the InP core-shell QDs to a type-I, quasi-type-II, or type-II bandgap structure with emission wavelengths ranging from 500-1300 nm depending on the shell material used (ZnS, ZnSe, CdS, or CdSe) and the thickness of the shell. Single molecule microscopy assessments of photobleaching and blinking are used to correlate NQD properties with shell thickness.

  18. Creep Modeling in a Composite Rotating Disc with Thickness Variation in Presence of Residual Stress

    Directory of Open Access Journals (Sweden)

    Vandana Gupta

    2012-01-01

    Full Text Available Steady-state creep response in a rotating disc made of Al-SiC (particle composite having linearly varying thickness has been carried out using isotropic/anisotropic Hoffman yield criterion and results are compared with those using von Mises yield criterion/Hill's criterion ignoring difference in yield stresses. The steady-state creep behavior has been described by Sherby's creep law. The material parameters characterizing difference in yield stresses have been used from the available experimental results in literature. Stress and strain rate distributions developed due to rotation have been calculated. It is concluded that the stress and strain distributions got affected from the thermal residual stress in an isotropic/anisotropic rotating disc, although the effect of residual stress on creep behavior in an anisotropic rotating disc is observed to be lower than those observed in an isotropic disc. Thus, the presence of residual stress in composite rotating disc with varying thickness needs attention for designing a disc.

  19. Estimating body composition from skinfold thicknesses and bioelectrical impedance analysis in cystic fibrosis patients.

    Science.gov (United States)

    Alicandro, Gianfranco; Battezzati, Alberto; Bianchi, Maria Luisa; Loi, Silvana; Speziali, Chiara; Bisogno, Arianna; Colombo, Carla

    2015-11-01

    The accuracy of body composition estimates based on skinfold thickness measurements and bioelectrical impedance analysis (BIA) is not yet adequately explored in cystic fibrosis (CF). Using DXA as reference method we verified the accuracy of these techniques and identified predictors of body composition specific for CF. One hundred forty-two CF patients (age range: 8-31 years) underwent a DXA scan. Body fat percentage (BF%) was estimated from skinfolds, while fat free mass (FFM) from single-frequency 50 kHz BIA. Bland-Altman analysis showed poor intra-individual agreement between body composition data provided by DXA and BF% estimated from skinfolds or FFM estimated from BIA. The skinfolds of the upper arm were better predictors of BF% than BMI, while compared to other BIA measurements the best predictor of FFM was the R-index (Height(2)/Resistance). Due to poor accuracy at individual level, the estimates of body composition obtained from these techniques cannot be part of the standard nutritional assessment of CF patients until reliable CF-specific equations will become available. BMI has limited value in predicting body fatness in CF patients and should be used in combination with other predictors. Skinfolds of the upper arm and R-index are strongly related to BF% and FFM and should be tested in a large CF population to develop specific predictive equations. Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  20. A rotary ultrasonic motor using radial bending mode of ring with nested PZT excitation

    Institute of Scientific and Technical Information of China (English)

    Ying-xiang LIU; Jun-kao LIU; Wei-shan CHEN; Xiao-hui YANG

    2012-01-01

    This study presents and verifies a new idea for constructing a rotary traveling wave ultrasonic motor (USM) that uses the radial bending mode of a ring.In the new design,20 trapezoid cross section slots are cut symmetrically in the outer surface of a thick duralumin alloy ring,where 20 PZT stacks are nested.In each slot,two wedging blocks are set between the PZT stack and the two sides of the slot respectively to apply preloading on the PZT ceramics.Two radial bending modes of the stator that have a phase difference of a quarter wavelength on space are generated by using the d33 operating mode of the PZT elements,and then a flexural traveling wave is formed by the superimposing of two standing waves whose amplitudes are equal and phases are different by 90° temporally.Two conical rotors are pressed to each end of the ring type stator by a coiled spring.The finite element method (FEM) simulation is developed to validate the feasibility of the proposed motor.The maximal speed and torque of the prototype are tested to be 126 r/min and 0.8 N·m,respectively.

  1. Mechanical and electrical strain response of a piezoelectric auxetic PZT lattice structure

    Science.gov (United States)

    Fey, Tobias; Eichhorn, Franziska; Han, Guifang; Ebert, Kathrin; Wegener, Moritz; Roosen, Andreas; Kakimoto, Ken-ichi; Greil, Peter

    2016-01-01

    A two-dimensional auxetic lattice structure was fabricated from a PZT piezoceramic. Tape casted and sintered sheets with a thickness of 530 μm were laser cut into inverted honeycomb lattice structure with re-entrant cell geometry (θ = -25°) and poling direction oriented perpendicular to the lattice plane. The in-plane strain response upon applying an uniaxial compression load as well as an electric field perpendicular to the lattice plane were analyzed by a 2D image data detection analysis. The auxetic lattice structure exhibits orthotropic deformation behavior with a negative in-plane Poisson’s ratio of -2.05. Compared to PZT bulk material the piezoelectric auxetic lattice revealed a strain amplification by a factor of 30-70. Effective transversal coupling coefficients {{d}al}31 of the PZT lattice exceeding 4 × 103 pm V-1 were determined which result in an effective hydrostatic coefficient {{d}al}h 66 times larger than that of bulk PZT.

  2. A Novel Integrated PZT-Driven Micropump and Microvalve

    Institute of Scientific and Technical Information of China (English)

    Zhaoxin Geng; Dafu Cui; Haining Wang; Changchun Liu; Bo Su

    2006-01-01

    According to the 'elastic buffer mechanism' and the'variable gap mechanism', a new device, which is both micropump and active microvalve actuated by PZT bimorph cantilever, was fabricated with polydimethylsiloxane (PDMS) and silicon chip. The thickness of the micropump membrance is about 180 μm. The diameter and the depth of micropump chamber cavity are 6 mm and 40 μm, respectively. The performances of the micropump, such as pump rate and backpressure, were characterized. As a flow-rectifying element, the diffusers and active valve were used instead of passive check valves. The flow rate and the backpressure of the micropump are about 420 μL/min and 2 kPa when applying a 100 V square wave driving voltage at frequency of 35 Hz.

  3. Fabrication and properties of SmFe2-PZT magnetoelectric thin films

    KAUST Repository

    Giouroudi, Ioanna

    2013-05-17

    Magnetoelectric (ME) thin film composites are attracting a continually increasing interest due to their unique features and potential applications in multifunctional microdevices and integrated units such as sensors, actuators and energy harvesting modules. By combining piezoelectric and highly magnetostrictive thin films, the potentialities of these materials increase. In this paper we report the fabrication of SmFe2 and PZT thin films and the investigation of their properties. First of all, a ~ 400 nm thin SmFe film was deposited on top of Si/SiO2 substrate by magnetron sputter deposition. Afterwards, a 140 nm Pt bottom electrode was sputtered on top of the SmFe film forming a bottom electrode. Spin coating was employed for the deposition of the 150 nm thin PZT layer. A PZT solution with 10 %Pb excess was utilized for this fabrication step. Finally, circular Pt top electrodes were sputtered as top electrodes. This paper focuses on the microstructure of the individual films characterized by X-Ray diffractometer (XRD) and scanning electron microscopy (SEM). A piezoelectric evaluation system, aixPES, with TF2000E analyzer component was used for the electric hysteresis measurements of PZT thin films and a vibrating sample magnetometer (VSM) was employed for the magnetic characterization of the SmFe. The developed thin films and the fabricated double layer SmFe-PZT exhibit both good ferromagnetic and piezoelectric responses which predict a promising ME composite structure. The quantitative chemical composition of the samples was confirmed by energy dispersive spectroscopy (EDX). © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  4. Color Stability of the Bulk-Fill Composite Resins with Different Thickness in Response to Coffee/Water Immersion

    Directory of Open Access Journals (Sweden)

    Sayna Shamszadeh

    2016-01-01

    Full Text Available We aimed to evaluate the color stability of bulk-fill and conventional composite resin with respect to thickness and storage media. Twenty specimens of a conventional composite resin (6 mm diameter and 2 mm thick and 40 specimens of the bulk-fill Tetric EvoCeram composite resin at two different thicknesses (6 mm diameter and 2 mm thick or 4 mm thick, n=20 were prepared. The specimens were stored in distilled water during the study period (28 d. Half of the specimens were remained in distilled water and the other half were immersed in coffee solution 20 min/d and kept in distilled water between the cycles. Color changes (ΔE were measured using the CIE L⁎a⁎b⁎ color space and a digital imaging system at 1, 7, 14, and 28 days of storage. Data were analyzed using Two-way ANOVA and Tukey’s HSD post hoc test (P conventional; P<0.001. Coffee exhibited significantly more staining susceptibility than that of distilled water (P<0.001. There was greater color changes with increasing the increment thickness, which was significant at 14 (P<0.001 and 28 d (P<0.01. Color change of bulk-fill composite resin was greater than that of the conventional one after coffee staining and is also a function of increment thicknesses.

  5. Thickness of CAD-CAM composite resin overlays influences fatigue resistance of endodontically treated premolars.

    Science.gov (United States)

    Magne, Pascal; Knezevic, Alena

    2009-10-01

    Evaluate the influence of composite resin CAD-CAM restoration thickness on the in vitro fatigue resistance and failure mode of overlay-type restoration in endodontically treated premolars. Thirty extracted premolars received root canal treatment followed by a standardized tooth preparation (1.5-, 2.5- or 3.5-mm cusp reduction, proximal gingival margins located 1.5mm below the CEJ, glass-ionomer base and immediately sealed dentin with Optibond FL). Restorations were milled using Cerec3 and FiltekMZ100 composite blocks. The intaglio surfaces of the overlays were sandblasted and silanated. Tooth preparations were sandblasted and etched before insertion of the restoration. All restorations were luted with Optibond FL and preheated FiltekZ100. A closed-loop servohydraulic unit was used for simulating cyclic isometric chewing at 5 Hz, starting with a load of 200 N (5000 cycles), followed by stages of 400, 600, 800, 1000, 1200 and 1400 N at a maximum of 30,000 cycles each. All samples were loaded until fracture or to a maximum of 185,000 cycles. Groups were compared using the Kaplan-Meier survival curves. None of the restored premolars with the 1.5-mm cusp overlap restoration withstood all 185,000 loading cycles. With 2.5- and 3.5-mm cusp overlap, the survival rate was 30% and 40%, respectively. The rate of fracture below the CEJ was 60%, 60% and 30% for 1.5, 2.5 and 3.5 mm of cusp overlap, respectively. Survival of restored premolars with 2.5- and 3.5-mm cusp coverage was not significantly different (p=.23). Thick FiltekMZ100 composite resin onlays showed higher fatigue resistance than thin ones and may be associated with fractures that are less subgingival.

  6. Magnetostatic Coupling in CoFe2O4/Pb(Zr0.53Ti0.47)O3 Magnetoelectric Composite Thin Films of 2-2 Type Structure

    Institute of Scientific and Technical Information of China (English)

    Yu-dong Xu; Lei Wang; Min Shi; Hai-lin Su; Guang Wu

    2012-01-01

    CoFe2O4/Pb(Zr0.5aTi0.47)O3 (CFO/PZT) magnetoelectric composite thin films of 2-2 type structure had been prepared onto Pt/Ti/SiO2/Si substrate by a sol-gel process and spin coating technique.The structure of the prepared thin film is substrate/PZT/CFO/PZT/CFO.Two CFO ferromagnetic layers are separated from each other by a thin PZT layer.The upper CFO layer is magnetostatically coupled with the lower CFO layer.Subsequent scanning electron microscopy (SEM) investigations show that the prepared thin films exhibit good morphologies and compact structure,and cross-sectional micrographs clearly display a multilayered nanostructure of multilayered thin films.The composite thin films exhibit both good magnetic and ferroelectric properties.The spacing between ferromagnetic layers can be varied by adjusting the thickness of intermediate PZT layer.It is found that the strength of magnetostatic coupling has a great impact on magnetoelectric properties of composite thin films,i.e.,the magnetoelectric voltage coefficient of composite thin film tends to increase with the decreasing of pacing between two neighboring CFO ferromagnetic layers as a result of magnetostatic coupling effect.

  7. Ferrimagnetic Tb-Fe Alloy Thin Films: Composition and Thickness Dependence of Magnetic Properties and All-Optical Switching

    Directory of Open Access Journals (Sweden)

    Birgit eHebler

    2016-02-01

    Full Text Available Ferrimagnetic rare earth - transition metal Tb-Fe alloy thin films exhibit a variety of different magnetic properties, which depends strongly on composition and temperature. In this study, first the influence of the film thickness (5 - 85 nm on the sample magnetic properties was investigated in a wide composition range between 15 at.% and 38 at.% of Tb. From our results, we find that the compensation point, remanent magnetization, and magnetic anisotropy of the Tb-Fe films depend not only on the composition but also on the thickness of the magnetic film up to a critical thickness of about 20-30 nm. Beyond this critical thickness, only slight changes in magnetic properties are observed. This behavior can be attributed to a growth-induced modification of the microstructure of the amorphous films, which affects the short range order. As a result, a more collinear alignment of the distributed magnetic moments of Tb along the out-of-plane direction with film thickness is obtained. This increasing contribution of the Tb sublattice magnetization to the total sample magnetization is equivalent to a sample becoming richer in Tb and can be referred to as an effective composition. Furthermore, the possibility of all-optical switching, where the magnetization orientation of Tb-Fe can be reversed solely by circularly polarized laser pulses, was analyzed for a broad range of compositions and film thicknesses and correlated to the underlying magnetic properties.

  8. A composite-appropriate integration method of thick functional components in fibre-reinforced plastics

    Science.gov (United States)

    Filippatos, A.; Höhne, R.; Kliem, M.; Gude, M.

    2016-03-01

    The use of integrated structural health monitoring systems for critical composite parts, such as wind turbine blades, fuselage and wing parts, is an promising approach to guarantee a safe and efficient operational lifetime of such components. Therefore, the integration of thick functional components like sensors, actuators and electronic components is often necessary. An optimal integration of such components should be ensured without material imperfections in the composite structure, i.e. voids and resin rich areas, and failure of the functional components. In this paper, first investigations were undertaken for a basic understanding of the mechanical performance of a fibre reinforced plastic component with integrated functional elements. The influence of different materials and treatment methods for the encapsulation of electronic components was experimentally investigated under static and dynamic loading tests. By means of a parametric finite element model, the effects of an encapsulation and various parameters such as the shape and orientation of the electronic components were examined. Several encapsulation variants were investigated in order to minimise the chance of failure initiations. Based both on experimental and numerical results, a preferred composite integration concept was selected for an electronic board and some first recommendations for an optimal integration were derived.

  9. Sputter deposition of PZT piezoelectric films on thin glass substrates for adjustable x-ray optics.

    Science.gov (United States)

    Wilke, Rudeger H T; Johnson-Wilke, Raegan L; Cotroneo, Vincenzo; Davis, William N; Reid, Paul B; Schwartz, Daniel A; Trolier-McKinstry, Susan

    2013-05-10

    Piezoelectric PbZr(0.52)Ti(0.48)O(3) (PZT) thin films deposited on thin glass substrates have been proposed for adjustable optics in future x-ray telescopes. The light weight of these x-ray optics enables large collecting areas, while the capability to correct mirror figure errors with the PZT thin film will allow much higher imaging resolution than possible with conventional lightweight optics. However, the low strain temperature and flexible nature of the thin glass complicate the use of chemical-solution deposition due to warping of the substrate at typical crystallization temperatures for the PZT. RF magnetron sputtering enabled preparation of PZT films with thicknesses up to 3 μm on Schott D263 glass substrates with much less deformation. X-ray diffraction analysis indicated that the films crystallized with the perovskite phase and showed no indication of secondary phases. Films with 1 cm(2) electrodes exhibited relative permittivity values near 1100 and loss tangents below 0.05. In addition, the remanent polarization was 26 μC/cm(2) with coercive fields of 33 kV/cm. The transverse piezoelectric coefficient was as high as -6.1±0.6 C/m(2). To assess influence functions for the x-ray optics application, the piezoelectrically induced deflection of individual cells was measured and compared with finite-element-analysis calculations. The good agreement between the results suggests that actuation of PZT thin films can control mirror figure errors to a precision of about 5 nm, allowing sub-arcsecond imaging.

  10. Failure of Laminated Composites at Thickness Discontinuities: An Experimental and Analytical Study

    Science.gov (United States)

    Lee, Sangwook; Knauss, Wolfgang

    1998-01-01

    Failure initiation of laminated composites at a thickness discontinuity is studied experimentally with the aid of an optical microscope under combined loading of tension, transverse shear and bending, making use of three- and four-point bending arrangements. Because transverse shear produced relatively small effects in failure initiation results are presented as tension-bending interactions. Two loading frames for three- and four-point bending were designed to apply moment and tension simultaneously to produce failure by generating a ply crack; this initiation was evaluated by finite element analysis using ABAQUS. For cross-plies bounding the interface at the base of the step it is found that a maximum strain criterion applied to the continuing (long) ply describes the failure initiation. Ultimate failure resulted at loads on the order of 25 to 35% higher than those at failure initiation.

  11. A new technology for production of high thickness carbon/carbon composites for launchers application

    Science.gov (United States)

    Albano, Marta; Delfini, Andrea; Pastore, Roberto; Micheli, Davide; Marchetti, Mario

    2016-11-01

    Carbon-Carbon (C/C) composites are known for their extraordinary stability and excellent mechanical properties, almost unchanged at high temperatures. Among the several advanced applications, C/C based materials can be used in engines as nozzle throat section for launchers. In particular, the main feature for such employment is the material high resistance in extreme thermal environment. On the other hand, large-size items are required for this kind of purposes, thus introducing criticalities in terms of material uniformity and final overall properties. Up to now, there no standard for the production of high thickness C/C structures. In this paper a novel manufacturing method is analyzed, following each phase of the process, from the carbon fiber preform design and preparation to the carbon densification by chemical vapor infiltration method. Five preforms of large dimensions with different characteristics have been manufactured and infiltrated. The realized prototypes have been then analyzed by means of mechanical, physical and morphological tests. Aim of the results of this preliminary work is to establish a set of guidelines for a well-defined high thickness C/C production method.

  12. Processable 3-nm thick graphene platelets of high electrical conductivity and their epoxy composites.

    Science.gov (United States)

    Meng, Qingshi; Jin, Jian; Wang, Ruoyu; Kuan, Hsu-Chiang; Ma, Jun; Kawashima, Nobuyuki; Michelmore, Andrew; Zhu, Shenmin; Wang, Chun H

    2014-03-28

    Graphene platelets (GnPs) are a class of novel 2D nanomaterials owing to their very small thickness (∼3 nm), high mechanical strength and electric conductivity (1460 S cm(-1)), and good compatibility with most polymers as well as cost-effectiveness. In this paper we present a low-cost processing technique for producing modified GnPs and an investigation of the electrical and mechanical properties of the resulting composites. After dispersing GnPs in solvent N-methyl-2-pyrrolidone, a long-chain surfactant (Jeffamine D 2000, denoted J2000) was added to covalently modify GnPs, yielding J2000-GnPs. By adjusting the ratio of GnPs to the solvent, the modified GnPs show different average thickness and thus electrical conductivity ranging from 694 to 1200 S cm(-1). To promote the exfoliation and dispersion of J2000-GnPs in a polymeric matrix, they were dispersed in the solvent again and further modified using diglycidyl ether of bisphenol A (DGEBA) producing m-GnPs, which were then compounded with an epoxy resin for the development of epoxy/m-GnP composites. A percolation threshold of electrical volume resistivity for the resulting composites was observed at 0.31 vol%. It was found that epoxy/m-GnP composites demonstrated far better mechanical properties than those of unmodified GnPs of the same volume fraction. For example, m-GnPs at 0.25 vol% increased the fracture energy release rate G1c from 0.204 ± 0.03 to 1.422 ± 0.24 kJ m(-2), while the same fraction of unmodified GnPs increased G1c to 1.01 ± 0.24 kJ m(-2). The interface modification also enhanced the glass transition temperature of neat epoxy from 58.9 to 73.8 °C.

  13. Processable 3-nm thick graphene platelets of high electrical conductivity and their epoxy composites

    Science.gov (United States)

    Meng, Qingshi; Jin, Jian; Wang, Ruoyu; Kuan, Hsu-Chiang; Ma, Jun; Kawashima, Nobuyuki; Michelmore, Andrew; Zhu, Shenmin; Wang, Chun H.

    2014-03-01

    Graphene platelets (GnPs) are a class of novel 2D nanomaterials owing to their very small thickness (˜3 nm), high mechanical strength and electric conductivity (1460 S cm-1), and good compatibility with most polymers as well as cost-effectiveness. In this paper we present a low-cost processing technique for producing modified GnPs and an investigation of the electrical and mechanical properties of the resulting composites. After dispersing GnPs in solvent N-methyl-2-pyrrolidone, a long-chain surfactant (Jeffamine D 2000, denoted J2000) was added to covalently modify GnPs, yielding J2000-GnPs. By adjusting the ratio of GnPs to the solvent, the modified GnPs show different average thickness and thus electrical conductivity ranging from 694 to 1200 S cm-1. To promote the exfoliation and dispersion of J2000-GnPs in a polymeric matrix, they were dispersed in the solvent again and further modified using diglycidyl ether of bisphenol A (DGEBA) producing m-GnPs, which were then compounded with an epoxy resin for the development of epoxy/m-GnP composites. A percolation threshold of electrical volume resistivity for the resulting composites was observed at 0.31 vol%. It was found that epoxy/m-GnP composites demonstrated far better mechanical properties than those of unmodified GnPs of the same volume fraction. For example, m-GnPs at 0.25 vol% increased the fracture energy release rate G1c from 0.204 ± 0.03 to 1.422 ± 0.24 kJ m-2, while the same fraction of unmodified GnPs increased G1c to 1.01 ± 0.24 kJ m-2. The interface modification also enhanced the glass transition temperature of neat epoxy from 58.9 to 73.8 °C.

  14. An Unconventional Inchworm Actuator Based on PZT/ERFs Control Technology

    Science.gov (United States)

    Liu, Guojun; Zhang, Yanyan; Liu, Jianfang; Li, Jianqiao; Tang, Chunxiu; Wang, Tengfei; Yang, Xuhao

    2016-01-01

    An unconventional inchworm actuator for precision positioning based on piezoelectric (PZT) actuation and electrorheological fluids (ERFs) control technology is presented. The actuator consists of actuation unit (PZT stack pump), fluid control unit (ERFs valve), and execution unit (hydraulic actuator). In view of smaller deformation of PZT stack, a new structure is designed for actuation unit, which integrates the advantages of two modes (namely, diaphragm type and piston type) of the volume changing of pump chamber. In order to improve the static shear yield strength of ERFs, a composite ERFs valve is designed, which adopts the series-parallel plate compound structure. The prototype of the inchworm actuator has been designed and manufactured in the lab. Systematic test results indicate that the displacement resolution of the unconventional inchworm actuator reaches 0.038 μm, and the maximum driving force and velocity are 42 N, 14.8 mm/s, respectively. The optimal working frequency for the maximum driving velocity is 120 Hz. The complete research and development processes further confirm the feasibility of developing a new type of inchworm actuator with high performance based on PZT actuation and ERFs control technology, which provides a reference for the future development of a new type of actuator. PMID:27022234

  15. An Unconventional Inchworm Actuator Based on PZT/ERFs Control Technology.

    Science.gov (United States)

    Liu, Guojun; Zhang, Yanyan; Liu, Jianfang; Li, Jianqiao; Tang, Chunxiu; Wang, Tengfei; Yang, Xuhao

    2016-01-01

    An unconventional inchworm actuator for precision positioning based on piezoelectric (PZT) actuation and electrorheological fluids (ERFs) control technology is presented. The actuator consists of actuation unit (PZT stack pump), fluid control unit (ERFs valve), and execution unit (hydraulic actuator). In view of smaller deformation of PZT stack, a new structure is designed for actuation unit, which integrates the advantages of two modes (namely, diaphragm type and piston type) of the volume changing of pump chamber. In order to improve the static shear yield strength of ERFs, a composite ERFs valve is designed, which adopts the series-parallel plate compound structure. The prototype of the inchworm actuator has been designed and manufactured in the lab. Systematic test results indicate that the displacement resolution of the unconventional inchworm actuator reaches 0.038 μm, and the maximum driving force and velocity are 42 N, 14.8 mm/s, respectively. The optimal working frequency for the maximum driving velocity is 120 Hz. The complete research and development processes further confirm the feasibility of developing a new type of inchworm actuator with high performance based on PZT actuation and ERFs control technology, which provides a reference for the future development of a new type of actuator.

  16. An Unconventional Inchworm Actuator Based on PZT/ERFs Control Technology

    Directory of Open Access Journals (Sweden)

    Guojun Liu

    2016-01-01

    Full Text Available An unconventional inchworm actuator for precision positioning based on piezoelectric (PZT actuation and electrorheological fluids (ERFs control technology is presented. The actuator consists of actuation unit (PZT stack pump, fluid control unit (ERFs valve, and execution unit (hydraulic actuator. In view of smaller deformation of PZT stack, a new structure is designed for actuation unit, which integrates the advantages of two modes (namely, diaphragm type and piston type of the volume changing of pump chamber. In order to improve the static shear yield strength of ERFs, a composite ERFs valve is designed, which adopts the series-parallel plate compound structure. The prototype of the inchworm actuator has been designed and manufactured in the lab. Systematic test results indicate that the displacement resolution of the unconventional inchworm actuator reaches 0.038 μm, and the maximum driving force and velocity are 42 N, 14.8 mm/s, respectively. The optimal working frequency for the maximum driving velocity is 120 Hz. The complete research and development processes further confirm the feasibility of developing a new type of inchworm actuator with high performance based on PZT actuation and ERFs control technology, which provides a reference for the future development of a new type of actuator.

  17. Modeling of PZT-induced Lamb wave propagation in structures by using a novel two-layer spectral finite element

    Science.gov (United States)

    Liu, Xiaotong; Zhou, Li; Ouyang, Qinghua

    2016-04-01

    This paper presents a novel two-layer spectral finite element model, consisting of PZT wafer and host structure, to simulate PZT-induced Lamb wave propagation in beam-like and plate-like structures. Based on the idea of equal displacement on the interface between PZT wafer and host structure, the one-dimensional spectral beam element of PZT-host beam and two-dimensional spectral plate element of PZT-host plate are considered as one hybrid element, respectively. A novel approach is proposed by taking the coupling effect of piezoelectric transducers in the thickness direction into account. The dynamic equation of the two-layer spectral element is derived from Hamilton's principle. Validity of the developed spectral finite element is verified through numerical simulation. The result indicates that, compared with the conventional finite element method (FEM) based on elasticity, the proposed spectral finite element is proved to have a high accuracy in modeling Lamb wave propagation, meanwhile, significantly improve the calculation efficiency.

  18. Co/Co3O4/PZT多铁复合薄膜的交换偏置效应及其磁电耦合特性∗%Exchange bias effect and magneto electric coupling behaviors in multiferroic Co/Co3O4/PZT composite thin films

    Institute of Scientific and Technical Information of China (English)

    李永超; 周航; 潘丹峰; 张浩; 万建国

    2015-01-01

    The multiferroic Co/Co3O4/PZT composite films are prepared on Pt/Ti/SiO2/Si wafers by sol-gel process combined with pulsed laser deposition method. The phase structures, microstructural topographies and element valence states of the composite films are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectrum (XPS). The ferroelectric, electrical and magnetic properties as well as the magnetoelectric coupling behaviors are measured, and the exchange bias effect and its influence on the magnetoelectric coupling behavior of the composite film are studied systematically. The results show the composite films have well-defined ferroelectric hysteresis loops with a remanent polarization value of ∼17 µC/cm2. The composite film exhibits evidently an exchange bias effect. Typically, a exchange bias field of ∼80 Oe is observed at 77 K. Both the exchange bias field and magnetic coercive field increase with reducing the temperature. The exchange bias field increases to 160 Oe when the temperature decreases to 10 K. The XPS results confirm that an about 5 nm-thick CoO layer appears at the Co/Co3O4 interface due to the oxygen diffusion during the preparation, indicating that the exchange bias effect at 77 K is caused by the pinning effect of the antiferromagnetic CoO layer while the exchange bias effect at 10 K originates from the combining effect of antiferromagnetic CoO and Co3O4 layers. The measurement results of magnetocapacitance versus magnetic field curves at different temperatures show that the composite films have remarkable magnetoelectric coupling properties. The response of capacitance to temperature changes with the variation of external magnetic field. Further investigations show that the composite film possesses distinct anisotropic magnetocapacitance effect. When the direction of the magnetic field changes, the magnetocapacitance of the composite film changes from positive value to negative value. Moreover

  19. Experimental and analytical investigation on the compressive response of GRP plain woven thick composite

    Science.gov (United States)

    Centala, Prabhakaran K.; Qian, Zhengfang; Khan, Akhtar S.

    1997-03-01

    Investigations comprising of experimental observations and analytical study have been systematically executed to evaluate the compressive response of a particular composite system which has potential for structural armor applications. The material being a multi-layered thick laminate is a random mode stacking of bi-axial, plain weave S2-Glass/S2-Glass fiber yarns with polyester resin (Cycom 4102) as binder material, thirty two percent by weight. Attention is focused to understand the three dimensional macroscopic behavior of the material subjected to unidirectional quasi-static and dynamic compressive loading conditions using state of the art procedures. Quasi-static (low to medium strain rates) experimental investigations were carried out on an MTS test system while the dynamic response was observed using the split Hopkinson pressure bar test equipment and on a modified Hopkinson pressure bar termed direct disk impact. A comparison of the results of the two setup is presented. The uniformity of the material's response is verified for different sized and shaped specimens. The material's elastic constants, strength and strain rate effects in the region of 10-5 - 103 sec-1 are reported in this paper. The directional failure modes under compressive loading are discussed with the aid of scanning electron micrographs. Based upon the physical construction of the composite, a unit cell representation is presented for analytical modeling. The numerical results of this model is compared to that of the experiment results obtained.

  20. Crossover from negative to positive magnetoresistance in superconductor/ferromagnet composites thick films

    Energy Technology Data Exchange (ETDEWEB)

    Paredes, O. [Centro de Materiales, Facultad de Ingenieria, Universidad de Narino, Ciudad Universitaria Torobajo, Pasto (Colombia); Baca, E. [Grupo de Ingenieria de Nuevos Materiales, Departamento de Fisica, Universidad del Valle, A.A. 25360 Cali (Colombia); Fuchs, D. [Karlsruhe Institute of Technology, Institut fuer Festkoerperphysik, P.O. Box 3640, Karlsruhe (Germany); Moran, O., E-mail: omoranc@unal.edu.c [Laboratorio de Materiales Ceramicos y Vitreos, Departamento de Fisica, Universidad Nacional de Colombia, Sede Medellin, A.A. 568 Medellin (Colombia)

    2010-11-15

    Thick films of ((Bi, Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x}){sub 0.95}/(LaSr{sub 0.7}Mn{sub 0.3}O{sub 3}){sub 0.05} [(Bi-2223){sub 0.95}(LSMO){sub 0.05}] composites were fabricated on (0 0 1)-oriented LaAlO{sub 3} substrates by a simple melting-quenching-annealing method and their structural, morphological and magnetoelectrical properties carefully studied. Analysis of the X-ray diffraction patterns suggested a highly oriented growth along the c-axis of LSMO. This preferred orientation, with the crystal c-axis being perpendicular to the plane of the substrate, was considered to be indicative of a textured growth mode. Electrical and magnetic measurements showed the presence of ferromagnetism and superconductivity in the composite at temperatures above room temperature and below T{approx}50 K, respectively. A clear crossover from negative to positive magnetoresistance was observed at {approx}80 K in a magnetic field as strong as 5 T.

  1. Self-assembly of monolayer-thick alumina particle-epoxy composite films.

    Science.gov (United States)

    Jackson, Bryan R; Liu, Xiangyuan; McCandlish, Elizabeth F; Riman, Richard E

    2007-11-06

    Monolayer-thick composite films composed of alpha-alumina and Spurr's epoxy were prepared via a self-assembly process known as fluid forming. The process makes use of a high-spreading-tension fluid composed of volatile and nonvolatile components to propel particles across the air-water interface within a water bath. Continuous addition of the particle suspension builds a 2D particle film at the air-water interface. The spreading fluid compresses the film into a densely packed array against a submerged substrate. The assembled monolayer is deposited onto the substrate by removing the substrate from the bath. A dispersion containing a narrow size distribution, 10 microm alpha-alumina particles, light mineral oil, and 2-propanol was spread at the air-water interface and the alumina particles were assembled into densely packed arrays with an aerial packing fraction (APF) of 0.88. However, when mineral oil was replaced by Spurr's epoxy nonuniform films with low packing density resulted. It was found that replacing 2-propanol with a mixture of 2-propanol and 1-butanol with a volume ratio of 4:1 produced uniform, densely packed alumina/epoxy composite films. The role of the solvent mixture will be discussed.

  2. Physical properties of inorganic PMW-PNN-PZT ceramics

    Science.gov (United States)

    Sin, Sang-Hoon; Yoo, Ju-hyun; Kim, Yong-Jin; Baek, Sam-ki; Ha, Jun-Soo; No, Chung-Han; Song, Hyun-Seon; Shin, Dong-Chan

    2015-07-01

    In this work, inorganic Pb(Mg1/2W1/2)0.03(Ni1/3Nb2/3)x(Zr0.5Ti0.5)0.97-xO3 (x = 0.02 ∼ 0.12) composition ceramics were fabricated by the conventional solid state reaction method. And then their micro structure and ferroelectric properties were investigated according to the amount of PNN substitution. Small amounts of Li2CO3 and CaCO3 were used in order to decrease the sintering temperature of the ceramics. The 0.10 mol PNN-substituted PMW-PNN- PZT ceramics sintered at 920°C showed the excellent physical properties of piezoelectric constant (d33), electromechanical coupling factor (kp), mechanical quality coefficient (Qm), and dielectric constant of 566 pC/N, 0.61, 73, and 2183, respectively.

  3. Oxygen inhibition layer of composite resins: effects of layer thickness and surface layer treatment on the interlayer bond strength.

    Science.gov (United States)

    Bijelic-Donova, Jasmina; Garoushi, Sufyan; Lassila, Lippo V J; Vallittu, Pekka K

    2015-02-01

    An oxygen inhibition layer develops on surfaces exposed to air during polymerization of particulate filling composite. This study assessed the thickness of the oxygen inhibition layer of short-fiber-reinforced composite in comparison with conventional particulate filling composites. The effect of an oxygen inhibition layer on the shear bond strength of incrementally placed particulate filling composite layers was also evaluated. Four different restorative composites were selected: everX Posterior (a short-fiber-reinforced composite), Z250, SupremeXT, and Silorane. All composites were evaluated regarding the thickness of the oxygen inhibition layer and for shear bond strength. An equal amount of each composite was polymerized in air between two glass plates and the thickness of the oxygen inhibition layer was measured using a stereomicroscope. Cylindrical-shaped specimens were prepared for measurement of shear bond strength by placing incrementally two layers of the same composite material. Before applying the second composite layer, the first increment's bonding site was treated as follows: grinding with 1,000-grit silicon-carbide (SiC) abrasive paper, or treatment with ethanol or with water-spray. The inhibition depth was lowest (11.6 μm) for water-sprayed Silorane and greatest (22.9 μm) for the water-sprayed short-fiber-reinforced composite. The shear bond strength ranged from 5.8 MPa (ground Silorane) to 36.4 MPa (water-sprayed SupremeXT). The presence of an oxygen inhibition layer enhanced the interlayer shear bond strength of all investigated materials, but its absence resulted in cohesive and mixed failures only with the short-fiber-reinforced composite. Thus, more durable adhesion with short-fiber-reinforced composite is expected.

  4. Constructing Uniform Core-Shell PPy@PANI Composites with Tunable Shell Thickness toward Enhancement in Microwave Absorption.

    Science.gov (United States)

    Tian, Chunhua; Du, Yunchen; Xu, Ping; Qiang, Rong; Wang, Ying; Ding, Ding; Xue, Jianlei; Ma, Jun; Zhao, Hongtao; Han, Xijiang

    2015-09-16

    Highly uniform core-shell composites, polypyrrole@polyaniline (PPy@PANI), have been successfully constructed by directing the polymerization of aniline on the surface of PPy microspheres. The thickness of PANI shells, from 30 to 120 nm, can be well controlled by modulating the weight ratio of aniline and PPy microspheres. PPy microspheres with abundant carbonyl groups have very strong affinity to the conjugated chains of PANI, which is responsible for the spontaneous formation of uniform core-shell microstructures. However, the strong affinity between PPy microspheres and PANI shells does not promote the diffusion or reassembly of two kinds of conjugated chains. Coating PPy microspheres with PANI shells increases the complex permittivity and creates the mechanism of interfacial polarization, where the latter plays an important role in increasing the dielectric loss of PPy@PANI composites. With a proper thickness of PANI shells, the moderate dielectric loss will produce well matched characteristic impedance, so that the microwave absorption properties of these composites can be greatly enhanced. Although PPy@PANI composites herein consume the incident electromagnetic wave by absolute dielectric loss, their performances are still superior or comparable to most PANI-based composites ever reported, indicating that they can be taken as a new kind of promising lightweight microwave absorbers. More importantly, microwave absorption of PPy@PANI composites can be simply modulated not only by the thickness of the absorbers, but also the shell thickness to satisfy the applications in different frequency bands.

  5. [Reconstruction of full-thickness nasal alar defect with combined nasolabial flap and free auricular composite flap].

    Science.gov (United States)

    Peng, Weihai; Rong, Li; Wang, Wangshu; Liu, Chao; Zhang, Duo

    2014-05-01

    To investigate the technique and its effect of combined nasolabial flap and free auricular composite flap for full-thickness nasal alar defect. From March 2010 to March 2013, 9 patients with full-thickness nasal alar defects were treated with combined nasolabial flaps and free auricular composite flaps. Composite auricular flap was used as inner lining and cartilage framework. The nasolabial flap at the same side was used as outer lining. All the patients were followed up for 6-18 months (average, 12 months). All the 9 composite auricular flaps survived completely. Epidermal necrosis happened at the distal end of 1 nasolabial flap. Alar rim was almost normal and symmetric nose was achieved in 6 cases. The arc and the thickness of the alar rim was not enough in 3 cases, resulting in asymmetric appearance. The survival area of auricular composite flap can be enlarged with nasolabial flap. The auricular helix edge can be reserved to reconstruct nasal alar rim with smooth and natural arc. Large full-thickness nasal alar defedts can be reconstructed with combined nasolabial flaps and free auricular composite flaps.

  6. Conductivity of composite membrane-based poly(ether-ether-ketone) sulfonated (SPEEK) nanofiber mats of varying thickness

    OpenAIRE

    Reyes, J L; Solorza-Feria, Omar; Garcia Bernabe, Abel; Giménez Torres, Enrique; Sahuquillo, Oscar; Compañ Moreno, Vicente

    2016-01-01

    Nanofiber mats of SPEEK70wt%-PVB30 wt% (polyvinyl butyral)-based composite membranes were prepared by varying the electrospinning time in order to obtain mats with different thicknesses. These mats were embedded in SPEEK65wt%-PVA(35wt%) (polyvinyl alcohol) polymer solution to fill the pores in the fibers. The obtained membranes with different mat thicknesses have been characterized by water uptake, ionic exchange capacity, scanning electron microscopy, mechanical properties and proton conduct...

  7. Temperature and strain rate effects on the piezoelectric charge production of PZT 95/5

    Science.gov (United States)

    Khan, Amnah S.; Proud, William G.

    2017-01-01

    To develop a better understanding of the piezoelectric ceramic lead zirconate titanate (PZT) 95/5, parameters including varying temperatures, porosities and strain rates have been studied. The effects on the charge output and fracture of poled PZT samples of different porosities have been investigated with compressive strain rates (10-4 - 10+3 s-1) using quasi-static loading equipment, drop-weight towers and Split Hopkinson Pressure Bars (SHPBs). The cylindrical specimens were of 4.4 mm diameter, thickness 0.8 - 4.4 mm, and density 7.3 - 8.3 g cm-3. The temperature range of -20 °C to +80 °C was achieved using purpose-built environmental chambers. The resulting stress-strain relationships are compared; all the samples ultimately displayed a brittle response at failure [1].

  8. A novel asymptotic expansion homogenization analysis for 3-D composite with relieved periodicity in the thickness direction

    KAUST Repository

    Nasution, Muhammad Ridlo Erdata

    2014-06-01

    A new asymptotic expansion homogenization analysis is proposed to analyze 3-D composite in which thermomechanical and finite thickness effects are considered. Finite thickness effect is captured by relieving periodic boundary condition at the top and bottom of unit-cell surfaces. The mathematical treatment yields that only 2-D periodicity (i.e. in in-plane directions) is taken into account. A unit-cell representing the whole thickness of 3-D composite is built to facilitate the present method. The equivalent in-plane thermomechanical properties of 3-D orthogonal interlock composites are calculated by present method, and the results are compared with those obtained by standard homogenization method (with 3-D periodicity). Young\\'s modulus and Poisson\\'s ratio obtained by present method are also compared with experiments whereby a good agreement is particularly found for the Young\\'s modulus. Localization analysis is carried out to evaluate the stress responses within the unit-cell of 3-D composites for two cases: thermal and biaxial tensile loading. Standard finite element (FE) analysis is also performed to validate the stress responses obtained by localization analysis. It is found that present method results are in a good agreement with standard FE analysis. This fact emphasizes that relieving periodicity in the thickness direction is necessary to accurately simulate the real free-traction condition in 3-D composite. © 2014 Elsevier Ltd.

  9. Development of dual PZT transducers for reference-free crack detection in thin plate structures.

    Science.gov (United States)

    Sohn, Hoon; Kim, Seuno Bum

    2010-01-01

    A new Lamb-wave-based nondestructive testing (NDT) technique, which does not rely on previously stored baseline data, is developed for crack monitoring in plate structures. Commonly, the presence of damage is identified by comparing "current data" measured from a potentially damaged stage of a structure with "baseline data" previously obtained at the intact condition of the structure. In practice, structural defects typically take place long after collection of the baseline data, and the baseline data can be also affected by external loading, temperature variations, and changing boundary conditions. To eliminate the dependence on the baseline data comparison, the authors previously developed a reference-free NDT technique using 2 pairs of collocated lead zirconate titanate (PZT) transducers placed on both sides of a plate. This reference-free technique is further advanced in the present study by the necessity of attaching transducers only on a single surface of a structure for certain applications such as aircraft. To achieve this goal, a new design of PZT transducers called dual PZT transducers is proposed. Crack formation creates Lamb wave mode conversion due to a sudden thickness change of the structure. This crack appearance is instantly detected from the measured Lamb wave signals using the dual PZT transducers. This study also suggests a reference-free statistical approach that enables damage classification using only the currently measured data set. Numerical simulations and experiments were conducted using an aluminum plate with uniform thickness and fundamental Lamb waves modes to demonstrate the applicability of the proposed technique to reference-free crack detection.

  10. Monolithic Pellets, Composites and Thick Films of Hydroxyapatite: Correlation of Mechanical Properties with Microstructure.

    Science.gov (United States)

    Wang, Pauchiu Either

    Hydroxyapatite Ca_{10}(PO _4)_6(OH)_2 (abbreviated as HA) has great biocompatibility. Poor mechanical properties of HA implants and decomposition of HA during processing are the major obstacles for widespread uses of HA. In the present thesis we have attempted to understand the sintering behavior of monolithic HA and metal-reinforced HA-matrix composites, and the mechanism of formation of HA coating in the solutions at the normal temperature. The powders of two calcium phosphates, namely hydroxyapatite and dicalcium phosphate (DCP: chemical formula Ca_2P_2O_7), were sintered at various temperatures and in various environments. The density, flexural strength and knoop hardness of both phosphates sintered in air for 4 h initially increased with the sintering temperature, reaching maxima at around 1000-1150 ^circC, and then decreased due to decomposition. To reduce dehydroxylation, HA powder was sintered in moisture at various temperatures up to 1350^circ C and X-ray diffraction study did not indicate any decomposition at the highest sintering temperature. It is seen that dehydroxylation did not hinder sintering, but decomposition obstructed sintering of both HA and DCP. Ductile-phase reinforcement of hydroxyapatite was achieved by addition of silver particulates (5-30 vol.%) in HA powder compacts. A composite made by sintering 10 vol.% Ag and balance HA at 1200^circ C for 1 h in air had flexural strength of 75 +/- 7 MPa, which was almost double that of pure HA sintered under an identical condition. Silver in the composite melted during sintering, but due to poor wetting, did not spread in between HA particles. The increase in the flexural strength of the composites was thought to be due to crack-bridging and crack-arrest by silver inclusions. Thick films (several μm) of hydroxyapatite were deposited on silicon single crystal placed in close proximity to a plate of apatite- and wollastonite -containing glass and dipped into a simulated body fluid (SBF) at 36^circ

  11. The Influence of Composite Thickness with or without Fibers on Fracture Resistance of Direct Restorations in Endodontically Treated Teeth

    OpenAIRE

    Torabzadeh, Hassan; Ghassemi, Amir; Sanei, Masoud; Razmavar, Sara; Sheikh-Al-Eslamian, Seyedeh Mahsa

    2014-01-01

    Introduction: This in vitro study evaluated the influence of composite thickness (with or without fiber reinforcement) on fracture resistance of direct restorations in endodontically treated teeth. Methods and Materials: Fifty-six intact human premolars were chosen and randomly divided into four groups (n=14). After preparation of a mesio-occluso-distal (MOD) cavities and cusp reduction, the teeth were endodontically treated. Subsequently, the samples were restored with composite resin using ...

  12. Thickness Determination for a Two-Layered Composite of a Film and a Plate by Low-Frequency Ultrasound

    Institute of Scientific and Technical Information of China (English)

    MAO Jie; LI Ming-Xuan; WANG Xiao-Min

    2007-01-01

    We present an ultrasonic method for determining the thickness of a composite consisting of a soft thin film attached to a hard plate substrate, by resonance spectra in the low frequency region. The interrogating waves can be incident only to the two-layered composite from the substrate side. The reflection spectra are obtained by FFT analysis of the compressive pulsed echoes from the composite, and the thicknesses of the film and the substrate are simultaneously inversed by the simulated annealing method from the resonant frequencies knowing other acoustical parameters in prior. The sensitivity of the method to individual thickness, its convergence and stability against experimental noises are studied. Experiment with interrogating wavelength 4 times larger than the film thickness in a sample of a polymer film (0.054 mm) on an aluminium plate (6.24 mm) verifies the validity of the method. The average relative errors in the measurement of the thicknesses of the film and the substrate are found to be -4.1% and -0.62%, respectively.

  13. Influence of terahertz waves on the penetration in thick FRP composite materials

    Science.gov (United States)

    Im, Kwang-Hee; Hsu, David K.; Chiou, Chien-Ping; Barnard, Daniel J.; Yang, In-Young; Park, Je-Woong

    2014-02-01

    Fiber reinforced plastics (FRP) are increasingly utilized in engineering structures because of their performance and fabrication advantages. With this increased utilization, a technique to gage quality and further characterize the materials would be beneficial. The nondestructive applications for Terahertz (T-ray) methods have also experienced increased utilization for evaluating engineering materials and will be reported on here in applications for the inspection and characterization of FRP materials used in wind energy components. First, refraction and transmission T-ray modes are used to determine the refractive index (n) of a glass fiber reinforced plastic (GFRP) reference sample, and extended for calculating the refractive indices for a sample of GFRP, balsa and epoxy. Additionally, carbon fiber reinforced plastic (CFRP) samples were evaluated with respect to fiber directions versus T-ray electric field polarization direction to evaluate the level of penetration of T-ray energy due to the fiber orientation dependent conductivity of this composite material. Finally, an evaluation of T-ray data was made to evaluate resonance effects, where the resonance frequency was found to agree with that expected from reflections from individual plies in thick GFRP laminates.

  14. Characterization by Confocal Laser Scanning Microscopy of the Phase Composition at Interfaces in Thick Films of Polymer Blends

    Directory of Open Access Journals (Sweden)

    Sandro Lattante

    2014-01-01

    Full Text Available Confocal Laser Scanning Microscopy (CLSM has been used as a fast, user-friendly, and noninvasive tool for characterizing the phase composition differences at the substrate and air interfaces in thick films of polymer blends. A clearly different phase composition at the blend/glass interface and at the blend/air interface has been detected. We show that PCBM preferentially accumulates at the glass/blend interface, while P3HT preferentially accumulates at the blend/air interface, by comparing the integrated signal intensity of the luminescence coming from both interfaces. Our results demonstrate that CLSM can be used conveniently for the fast identification of a preferential phase segregation at interfaces in polymer blends. This is useful in the research field on devices (like sensors or planar waveguides that are based on very thick layers (thickness higher than 1 μm.

  15. Effect of sol temperature on structural, morphological and magnetic properties of PZT thin films on alumina substrate

    Science.gov (United States)

    Sreelalitha, K.; Thyagarajan, K.

    2016-01-01

    In the present study, we investigate the structural, morphological and magnetic properties of sol-gel spin-coated PZT thin films on alumina substrate. The morphotropic phase boundary (MPB) of PZT [Pb (Zr1-xTix)03] between the tetragonal and rhombohedral phases occurs at the Zr/Ti ratio of 52/48. At the MPB the physical properties of PZT are of far-reaching importance due to their possible crystalline phases. In this study Pb(Zr0.52Ti0.48)03 sols are prepared at room temperature and at 125 °C. The gels are coated onto alumina substrate using a spin-coating unit as two and three layers. The structural studies using XRD confirm the perovskite phase formation at an annealing temperature of 660 °C for both films. The structural parameter grain size, dislocation density, lattice parameters and strain were dependent on the sol temperature. The SEM morphology of the samples represents well-developed dense grain structure and thickness in micrometer ranges. The VSM analysis shows diamagnetic and ferromagnetic hysteresis loop. The ferromagnetism at low fields in PZT films is confirmed by studying the magnetic properties of powder made of the same gel. The effect of heat treatment on the gel preparation is observed on structural, morphological and magnetic properties of PZT thin films. The ferromagnetism in PZT can be attributed to oxygen vacancies. The squareness ratio of the films shows the application of the films as a high-density recording medium.

  16. Ceramics like PZT-PMN; Ceramicas do tipo PZT-PMN

    Energy Technology Data Exchange (ETDEWEB)

    Droescher, R.E.; Sousa, V.C. [Universidade Federal do Rio Grande do Sul (LABIOMAT/DEMAT/UFRGS), Porto Alegre, RS (Brazil). Dept. de Materiais. Lab. de Biomateriais; Bergman, C.P. [Universidade Federal do Rio Grande do Sul (LACER/DEMAT/UFRGS), Porto Alegre, RS (Brazil). Dept. de Materiais. Lab. de Ceramicas Avancadas

    2009-07-01

    The goal of this work was to achieve piezoelectric ceramics referring to the system PZT-PMN Pb(Mg{sub 1}/{sub 3}Nb{sub 2}/{sub 3}Zr{sub 0},{sub 52}Ti{sub 0},{sub 48})O{sub 3} . Have been analysed ceramics like 0,65PZT-0,35PMN ((Pb(Mg{sub 0},{sub 1167}Nb{sub 0},{sub 2300}Zr{sub 0},{sub 3380}Ti{sub 0},{sub 3120})O{sub 3}), 0,75PZT-0,25PMN ((Pb(Mg{sub 0},{sub 083}Nb{sub 0}.{sub 1675}Zr{sub 0},{sub 3900}Ti{sub 0},{sub 3600})O3) and the 0,85PZT-0,15PMN ((Pb(Mg{sub 0,0500}Nb{sub 0},{sub 1000}Zr{sub 0},{sub 4420}Ti{sub 0},{sub 4080})O{sub 3}). The influence of the calcination and concentration of PZT on the lattice phases, microstructure and density was evaluated. Then, the method used was the mixed-oxide method, the samples were taken under different temperatures of calcination before the final sinterizing. The DRX and SEM techniques were used to identify the phases formed and analyse the microstructure, respectively. The main result revealed that, the better way is to realize three burns before the final sinterizing at 1200 o C/4 h . Like that, on obtain for sure the average lattice phases, like: perovskite, pyrochlore and PbO and also tend to densify the samples. (author)

  17. Optimization of electrode geometry and piezoelectric layer thickness of a deformable mirror

    Directory of Open Access Journals (Sweden)

    Nováková Kateřina

    2013-05-01

    Full Text Available Deformable mirrors are the most commonly used wavefront correctors in adaptive optics systems. Nowadays, many applications of adaptive optics to astronomical telescopes, high power laser systems, and similar fast response optical devices require large diameter deformable mirrors with a fast response time and high actuator stroke. In order to satisfy such requirements, deformable mirrors based on piezoelectric layer composite structures have become a subject of intense scientific research during last two decades. In this paper, we present an optimization of several geometric parameters of a deformable mirror that consists of a nickel reflective layer deposited on top of a thin lead zirconate titanate (PZT piezoelectric disk. Honeycomb structure of gold electrodes is deposited on the bottom of the PZT layer. The analysis of the optimal thickness ratio between the PZT and nickel layers is performed to get the maximum actuator stroke using the finite element method. The effect of inter-electrode distance on the actuator stroke and influence function is investigated. Applicability and manufacturing issues are discussed.

  18. Electrical Impedance Measurements of PZT Nanofiber Sensors

    Directory of Open Access Journals (Sweden)

    Richard Galos

    2017-01-01

    Full Text Available Electrical impedance measurements of PZT nanofiber sensors were performed using a variety of methods over a frequency spectrum ranging from DC to 1.8 GHz. The nanofibers formed by electrospinning with diameters ranging from 10 to 150 nm were collected and integrated into sensors using microfabrication techniques. Special matching circuits with ultrahigh input impedance were fabricated to produce low noise, measurable sensor outputs. Material properties including resistivity and dielectric constant are derived from the impedance measurements. The resulting material properties are also compared with those of individual nanofibers being tested using conductive AFM and Scanning Conductive Microscopy.

  19. A Piezoelectric PZT Ceramic Mulitlayer Stack for Energy Harvesting Under Dynamic Forces

    Science.gov (United States)

    Xu, Tian-Bing; Siochi, Emilie J.; Kang, Jin Ho; Zuo, Lei; Zhou, Wanlu; Tang, Xiudong; Jiang, Xiaoning

    2011-01-01

    Piezoelectric energy harvesting transducers (PEHTs) are commonly used in motion/vibration energy scavenging devices. To date, most researchers have focused on energy harvesting at narrow bandwidths around the mechanical resonance frequency, and most piezoelectric harvesting devices reported in the literature have very low effective piezoelectric coefficient (d(sub eff)) (piezoelectric coefficients of about 100 pC/N. The level of harvested electrical power for CBPEHTs is on the order of microW even at resonance mode. In order to harvest more electrical energy across broader bandwidth, high effective piezoelectric coefficient structures are needed. In this study, we investigate a "33" longitudinal mode, piezoelectric PZT ceramic multilayer stack (PZT-Stack) with high effective piezoelectric coefficient for high-performance PEHTs. The PZT-Stack is composed of 300 layers of 0.1 mm thick PZT plates, with overall dimensions of 32.4 mm X 7.0 mm X 7.0 mm. Experiments were carried out with dynamic forces in a broad bandwidth ranging from 0.5 Hz to 25 kHz. The measured results show that the effective piezoelectric coefficient of the PZT-stack is about 1 X 10(exp 5) pC/N at off-resonance frequencies and 1.39 X 10(exp 6) pC/N at resonance, which is order of magnitude larger than that of traditional PEHTs. The effective piezoelectric coefficients (d(sub eff)) do not change significantly with applied dynamic forces having root mean square (RMS) values ranging from 1 N to 40 N. In resonance mode, 231 mW of electrical power was harvested at 2479 Hz with a dynamic force of 11.6 N(sub rms), and 7.6 mW of electrical power was generated at a frequency of 2114 Hz with 1 N(sub rms) dynamic force. In off-resonance mode, an electrical power of 18.7 mW was obtained at 680 Hz with a 40 N(sub rms) dynamic force. A theoretical model of energy harvesting for the PZT-Stack is established. The modeled results matched well with experimental measurements. This study demonstrated that high

  20. A Piezoelectric PZT Ceramic Mulitlayer Stack for Energy Harvesting Under Dynamic Forces

    Science.gov (United States)

    Xu, Tian-Bing; Siochi, Emilie J.; Kang, Jin Ho; Zuo, Lei; Zhou, Wanlu; Tang, Xiudong; Jiang, Xiaoning

    2011-01-01

    Piezoelectric energy harvesting transducers (PEHTs) are commonly used in motion/vibration energy scavenging devices. To date, most researchers have focused on energy harvesting at narrow bandwidths around the mechanical resonance frequency, and most piezoelectric harvesting devices reported in the literature have very low effective piezoelectric coefficient (d(sub eff)) (harvested electrical power for CBPEHTs is on the order of microW even at resonance mode. In order to harvest more electrical energy across broader bandwidth, high effective piezoelectric coefficient structures are needed. In this study, we investigate a "33" longitudinal mode, piezoelectric PZT ceramic multilayer stack (PZT-Stack) with high effective piezoelectric coefficient for high-performance PEHTs. The PZT-Stack is composed of 300 layers of 0.1 mm thick PZT plates, with overall dimensions of 32.4 mm X 7.0 mm X 7.0 mm. Experiments were carried out with dynamic forces in a broad bandwidth ranging from 0.5 Hz to 25 kHz. The measured results show that the effective piezoelectric coefficient of the PZT-stack is about 1 X 10(exp 5) pC/N at off-resonance frequencies and 1.39 X 10(exp 6) pC/N at resonance, which is order of magnitude larger than that of traditional PEHTs. The effective piezoelectric coefficients (d(sub eff)) do not change significantly with applied dynamic forces having root mean square (RMS) values ranging from 1 N to 40 N. In resonance mode, 231 mW of electrical power was harvested at 2479 Hz with a dynamic force of 11.6 N(sub rms), and 7.6 mW of electrical power was generated at a frequency of 2114 Hz with 1 N(sub rms) dynamic force. In off-resonance mode, an electrical power of 18.7 mW was obtained at 680 Hz with a 40 N(sub rms) dynamic force. A theoretical model of energy harvesting for the PZT-Stack is established. The modeled results matched well with experimental measurements. This study demonstrated that high effective piezoelectric coefficient structures enable PEHTs to

  1. Energy harvesting from vertically aligned PZT nanowire arrays

    Science.gov (United States)

    Malakooti, Mohammad H.; Zhou, Zhi; Sodano, Henry A.

    2016-04-01

    In this paper, a nanostructured piezoelectric beam is fabricated using vertically aligned lead zirconate titanate (PZT) nanowire arrays and its capability of continuous power generation is demonstrated through direct vibration tests. The lead zirconate titanate nanowires are grown on a PZT thin film coated titanium foil using a hydrothermal reaction. The PZT thin film serves as a nucleation site while the titanium foil is used as the bottom electrode. Electromechanical frequency response function (FRF) analysis is performed to evaluate the power harvesting efficiency of the fabricated device. Furthermore, the feasibility of the continuous power generation using the nanostructured beam is demonstrated through measuring output voltage from PZT nanowires when beam is subjected to a sinusoidal base excitation. The effect of tip mass on the voltage generation of the PZT nanowire arrays is evaluated experimentally. The final results show the great potential of synthesized piezoelectric nanowire arrays in a wide range of applications, specifically power generation at nanoscale.

  2. Thin PZT-Based Ferroelectric Capacitors on Flexible Silicon for Nonvolatile Memory Applications

    KAUST Repository

    Ghoneim, Mohamed T.

    2015-04-24

    A flexible version of traditional thin lead zirconium titanate ((Pb1.1Zr0.48Ti0.52O3)-(PZT)) based ferroelectric random access memory (FeRAM) on silicon shows record performance in flexible arena. The thin PZT layer requires lower operational voltages to achieve coercive electric fields, reduces the sol-gel coating cycles required (i.e., more cost-effective), and, fabrication wise, is more suitable for further scaling of lateral dimensions to the nano-scale due to the larger feature size-to-depth aspect ratio (critical for ultra-high density non-volatile memory applications). Utilizing the inverse proportionality between substrate\\'s thickness and its flexibility, traditional PZT based FeRAM on silicon is transformed through a transfer-less manufacturable process into a flexible form that matches organic electronics\\' flexibility while preserving the superior performance of silicon CMOS electronics. Each memory cell in a FeRAM array consists of two main elements; a select/access transistor, and a storage ferroelectric capacitor. Flexible transistors on silicon have already been reported. In this work, we focus on the storage ferroelectric capacitors, and report, for the first time, its performance after transformation into a flexible version, and assess its key memory parameters while bent at 0.5 cm minimum bending radius.

  3. Effect of solid content variations on PZT slip for tape casting

    Directory of Open Access Journals (Sweden)

    Gang Jian

    2012-12-01

    Full Text Available Lead zirconate titanate (PZT particles with pure tetragonal structure were synthesized by solid-state reaction method and used for preparation of slurries with different solid contents (34–80 wt.%. Then, PZT thick films were fabricated by the nonaqueous tape casting method. It was shown that the slurry prepared from ball-milled particles exhibited better rheology properties than slurry from particles which were not ball-milled. Measurement of sedimentation volumes and zeta potentials indicated particle aggregation, resulting in weak stability of the slurries with high solid contents. The microstructure, piezoelectric and ferroelectric properties of PZT sintered films were investigated in terms of solid contents. Ceramic films prepared from the slurry with solid contents of 73 wt.% had the optimal structure and properties. After poling at 200 °C with an applied field of 1.2 kV/cm, a d33 of 294 pC/N was achieved; typical ferroelectric properties were also observed with a Ps of 38 μC/cm2.

  4. Temperature dependent mechanical property of PZT film: an investigation by nanoindentation.

    Directory of Open Access Journals (Sweden)

    Yingwei Li

    Full Text Available Load-depth curves of an unpoled Lead Zirconate Titanate (PZT film composite as a function of temperature were measured by nanoindentation technique. Its reduce modulus and hardness were calculated by the typical Oliver-Pharr method. Then the true modulus and hardness of the PZT film were assessed by decoupling the influence of substrate using methods proposed by Zhou et al. and Korsunsky et al., respectively. Results show that the indentation depth and modulus increase, but the hardness decreases at elevated temperature. The increasing of indentation depth and the decreasing of hardness are thought to be caused by the decreasing of the critical stress needed to excite dislocation initiation at high temperature. The increasing of true modulus is attributed to the reducing of recoverable indentation depth induced by back-switched domains. The influence of residual stress on the indentation behavior of PZT film composite was also investigated by measuring its load-depth curves with pre-load strains.

  5. Coating thickness control in continuously fabricating metallic glass-coated composite wires

    Science.gov (United States)

    Zhang, Bao-yu; Chen, Xiao-hua; Lu, Zhao-ping; Hui, Xi-dong

    2013-05-01

    A continuous production process was developed for coating bulk metallic glasses on the metallic wire surface. The effects of processing parameters, including the drawing velocity and coating temperature, on the coating thickness were investigated. It is found that the coating thickness increases with the increase in drawing velocity but decreases with the increase in coating temperature. A fluid mechanical model was developed to quantify the coating thickness under various processing conditions. By using this theoretical model, the coating thickness was calculated, and the calculated values are in good agreement with the experimental data.

  6. INVESTIGATION ON STABILITY OF PZT/EPOXY PIEZOCOMPOSITE WITH PRESSURE AND TEMPERATURE

    Institute of Scientific and Technical Information of China (English)

    Likun Wang; Yuanyuan Wan; Li Li; Lei Qin; Yi Lu

    2009-01-01

    With the universal test machine and temperature test chamber, the effect of pres-sure and temperature on the behavior of 1-3 and 1-3-2 piezocomposites prepared with PZT/epoxy in our lab has been investigated through electrical impedance and dielectric analysis. The per-mittivity, resonant frequency and dielectric loss of the composites have been measured under vertical stress and temperature, and the variety of the material properties under pressure and temperature could also be obtained. The pressure and temperature stability of the composites have been assessed through experiments. The data of these two types of composites indicated that the stability of 1-3-2 composite with pressure was better than that of 1-3 composite, and two composites have almost the same dielectric stability with temperature. However, 1-3-2 composite showed slower frequency variation than 1-3 composite.

  7. Fabrication and Performances of 1-3-2 Piezoelectric Ceramic/Polymer Composite

    Institute of Scientific and Technical Information of China (English)

    Likun Wang; Guang Li; Hongliang Du; Lei Qin; Shuxiang Li

    2006-01-01

    A novel 1-3-2 piezoelectric composite has been developed, which consists of piezoelectric ceramic plate and 1-3 piezoelectric composite. The composite was fabricated by dicing PZT ceramic along mutual perpendicular two directions and then filling epoxy into grooves. The piezoelectric and electromechanical properties of the novel composite were determined.The results show a coefficient d33 of 405 pC/N, a vibration displacement of 113.5 pm, an acoustic impendence of 13.3 Mraly,a bandwidth of 12 kHz and a thickness electromechanical coupling coefficient of 0.56.

  8. Thermoelectric-pyroelectric hybrid energy generation from thermopower waves in core-shell structured carbon nanotube-PZT nanocomposites

    Science.gov (United States)

    Yeo, Taehan; Hwang, Hayoung; Shin, Dongjoon; Seo, Byungseok; Choi, Wonjoon

    2017-02-01

    There is an urgent need to develop a suitable energy source owing to the rapid development of various innovative devices using micro-nanotechnology. The thermopower wave (TW), which produces a high specific power during the combustion of solid fuel inside micro-nanostructure materials, is a unique energy source for unusual platforms that cannot use conventional energy sources. Here, we report on the significant enhancement of hybrid energy generation of pyroelectrics and thermoelectrics from TWs in carbon nanotube (CNT)-PZT (lead zirconate titanate, P(Z0.5-T0.5)) composites for the first time. Conventional TWs use only charge carrier transport driven by the temperature gradient along the core materials to produce voltage. In this study, a core-shell structure of CNTs-PZTs was prepared to utilize both the temperature gradient along the core material (thermoelectrics) and the dynamic change in the temperature of the shell structure (pyroelectrics) induced by TWs. The dual mechanism of energy generation in CNT-PZT composites amplified the average peak and duration of the voltage up to 403 mV and 612 ms, respectively, by a factor of 2 and 60 times those for the composites without a PZT layer. Furthermore, dynamic voltage measurements and structural analysis in repetitive TWs confirmed that CNT-PZT composites maintain the original performance in multiple TWs, which improves the reusability of materials. The advanced TWs obtained by the application of a PZT layer as a pyroelectric material contributes to the extension of the usable energy portion as well as the development of TW-based operating devices.

  9. Crustal thickness and composition beneath the High Lava Plains of Eastern Oregon from teleseismic receiver functions

    Science.gov (United States)

    Eagar, K. C.; Fouch, M. J.; James, D. E.; Carlson, R. W.

    2009-12-01

    The nature of the crust beneath the High Lava Plains of eastern Oregon is fundamental for understanding the origins of widespread Cenozoic volcanism in the region. Eruptions of flood basalts in the southern Cascadian back arc peaked ~17-15 Ma, and were followed by distributed bimodal volcanism along two perpendicular migrating tracks; the Snake River Plain and the High Lava Plains. The orientations of eruptive centers have led to several competing hypotheses about their cause, including a deep mantle plume, slab retreat and asthenospheric inflow, lithospheric delamination, and lithospheric extension. The goal of this project is to constrain the nature, geometry, and depth of the Moho across the High Lava Plains, which will shed light on questions regarding crustal influence on melt generation and differentiation and the degree of magmatic underplating. In this study, we analyze teleseismic receiver functions from 118 stations of the High Lava Plains temporary broadband array, 34 nearby EarthScope/USArray stations, and 5 other regional broadband stations to determine bulk crustal features of thickness (H) and Vp/Vs ratio (κ). Applying the H-κ stacking method, we search for the best-fitting solution of timing predictions for direct and multiple P-to-S conversions from the Moho interface. Converting Vp/Vs to Poisson ratio, which is dependent primarily upon rock composition, allows for comparison with other direct geological observations. Preliminary results show that the crust of the High Lava Plains is relatively thin (~31 km) with a very sharp gradient to thicker crust (~42 km) at the western edge of the Owyhee Plateau in southwestern Idaho. This gradient is co-located with the western margin of Precambrian North America and is in the vicinity of the Jordan Craters volcanic center. The sharp topography of the Moho might have been a factor in melt migration beneath this area. West of the High Lava Plains, the crust thickens to ~40 km into the Cascade volcanic arc

  10. Monitoring the integrity of massive aluminum structures using PZT transducers and the technique of impedance

    Science.gov (United States)

    da Costa, Rosalba; Maia, Joaquim M.; Assef, Amauri A.; Pichorim, Sergio F.; Costa, Eduardo T.; L. S. N. Button, Vera

    2015-04-01

    Safety, performance, economy and durability are essential items to qualify materials for the manufacturing of structures used in different areas. Generally, the materials used for this purpose are formed by composites and sometimes they can present failure during the manufacturing process. Such failures can also occur during use due to fatigue and wear, causing damage often difficult to be visually detected. In these cases, the use of non destructive testing (NDT) has proven to be a good choice for assessing the materials quality. The objective of this work was the electromechanical impedance evaluation of massive aluminum structures using ultrasonic transducers to detect discontinuities in the material. The tests have been done using an impedance analyzer (Agilent 4294A), an ultrasound transducer (1.6 MHz of central frequency), two types of PZT ceramics (0.267 mm and 1 mm thickness) and four aluminum samples (250 x 50 x 50 mm) with the transducer placed at three different regions. One sample was kept intact (reference) and the others were drilled in three positions with different sizes of holes (5 mm. 8 mm and 11 mm). The electromechanical impedance was recorded for each sample. The root mean square deviation index (RMSD) between the impedance magnitude of the reference and damaged samples was calculated and it was observed an increase in the RMSD due to the increase of the diameter of the holes (failures) in the samples completely drilled. The results show that the proposed methodology is suitable for monitoring the integrity of aluminum samples. The technique may be evaluated in characterizing other materials to be used in the construction of prostheses and orthoses.

  11. Nuchal Skinfold Thickness: A Novel Parameter for Assessment of Body Composition in Childhood Craniopharyngioma.

    Science.gov (United States)

    Sterkenburg, Anthe S; Hoffmann, Anika; Reichel, Julia; Lohle, Kristin; Eveslage, Maria; Warmuth-Metz, Monika; Müller, Hermann L

    2016-12-01

    Hypothalamic obesity, cardiovascular disease (CVD), and relapse/progression have a major impact on prognosis in childhood-onset craniopharyngioma (CP). We analyzed nuchal skinfold thickness (NST) on magnetic resonance imaging performed for follow-up monitoring as a novel parameter for body composition (BC) and CVD in CP. The objective of the study was to identify the association of NST with body mass index (BMI), waist to height ratio (WHtR), functional capacity, and blood pressure (BP) in CP and controls. This was a cross-sectional and longitudinal prospective study in CP patients. The study was conducted at HIT-Endo, KRANIOPHARYNGEOM 2000/2007. Participants included 94 CP patients and 75 controls. There were no interventions. Association of NST with BC and BP in 43 CP and 43 controls was measured. NST correlated with BMI SD score (SDS; r = 0.78; P < .001; n = 169) and WHtR (r = 0.85; P < .001; n = 86) in the total cohort and CP patients (NST-BMI SDS: r = 0.77, P < .001, n = 94); NST-WHtR: r = 0.835, P < .001, n=43) and controls (NST-BMI SDS: r = 0.792, P < .001, n = 75; NST-WHtR: r = 0.671, P < .001, n = 43). In CP, systolic BP correlated with NST (r = 0.575, P < .001), BMI SDS (r = 0.434, P = .004), and WHtR (r = 0.386, P = .011). Similar results were observed for diastolic BP in CP. In multivariate analyses, NST had a predictive value for hypertension in postpubertal CP and controls (odds ratio 6.98, 95% confidence interval [1.65, 29.5], P = .008). During a longitudinal follow-up, changes in NST correlated with changes in BMI SDS (P < .001) and WHtR (P = .01) but not with changes in BP and functional capacity. Because monitoring of magnetic resonance imaging and BC is essential for follow-up in CP, NST could serve as a novel and clinically relevant parameter for longitudinal assessment of BC and CVD risk in CP.

  12. Electrochemical and Reaction Bonding Processing of Thick ZrO2/Al2O3 Composite Coatings

    Institute of Scientific and Technical Information of China (English)

    WANGZhou-cheng; XIAOPing

    2004-01-01

    A novel technique combining electrophoretic deposition (EPD) and reaction bonding process (RBP) is developed to fabricate thick ZrO2/Al2O3 composite coatings. Mixed organic solvents are used here to make suspension containing yttria stablised zirconia (YSZ) and aluminium (Al). The results show that densely packed green form coatings are deposited using a mixture of ethanol and acetylacetone as suspension medium and ball milling for 48 hours. On subsequent heat treatment, melting and oxidation of aluminium in the green forms promote densification during sintering. By these means,thick, uniform and crack-free ZrO2/Al2O3 composite coatings have been fabricated on metal substrate.

  13. Electrochemical and Reaction Bonding Processing of Thick ZrO2/Al2O3 Composite Coatings

    Institute of Scientific and Technical Information of China (English)

    WANG Zhou-cheng; XIAO Ping

    2004-01-01

    A novel technique combining electrophoretic deposition (EPD) and reaction bonding process (RBP) is developed to fabricate thick ZrO2/Al2O3 composite coatings. Mixed organic solvents are used here to make suspension containing yttria stablised zirconia (YSZ) and aluminium (Al). The results show that densely packed green form coatings are deposited using a mixture of ethanol and acetylacetone as suspension medium and ball milling for 48 hours. On subsequent heat treatment, melting and oxidation of aluminium in the green forms promote densification during sintering. By these means,thick, uniform and crack-free ZrO2/Al2O3 composite coatings have been fabricated on metal substrate.

  14. Dynamic tensile stress–strain characteristics of carbon/epoxy laminated composites in through-thickness direction

    Directory of Open Access Journals (Sweden)

    Nakai Kenji

    2015-01-01

    Full Text Available The effect of strain rate up to approximately ε̇ = 102/s on the tensile stress–strain properties of unidirectional and cross-ply carbon/epoxy laminated composites in the through-thickness direction is investigated. Waisted cylindrical specimens machined out of the laminated composites in the through-thickness direction are used in both static and dynamic tests. The dynamic tensile stress–strain curves up to fracture are determined using the split Hopkinson bar (SHB. The low and intermediate strain-rate tensile stress–strain relations up to fracture are measured on an Instron 5500R testing machine. It is demonstrated that the ultimate tensile strength and absorbed energy up to fracture increase significantly, while the fracture strain decreases slightly with increasing strain rate. Macro- and micro-scopic examinations reveal a marked difference in the fracture surfaces between the static and dynamic tension specimens.

  15. Translucency of esthetic dental restorative CAD/CAM materials and composite resins with respect to thickness and surface roughness.

    Science.gov (United States)

    Awad, Daniel; Stawarczyk, Bogna; Liebermann, Anja; Ilie, Nicoleta

    2015-06-01

    Little information is available about the translucency of monolithic CAD/CAM materials. The purpose of this study was to evaluate the translucency of restorative CAD/CAM materials and direct composite resins with respect to thickness and surface roughness. In total, 240 disk-shaped specimens (12×14×1 mm and 12×14×2 mm) of 3 different CAD/CAM glass ceramics (CELTRA Duo, IPS e.max CAD, IPS Empress CAD), a fine-structure feldspathic ceramic (VITA Mark II), a hybrid ceramic (VITA Enamic), a resin nanoceramic composite resin (LAVA Ultimate), an experimental (CAD/CAM nanohybrid composite resin), 2 interim materials (Telio CAD; VITA CAD-Temp), and 3 direct composite resins (Tetric EvoCeram; Filtek Supreme XTE; Tetric EvoCeram Bulk Fill) were fabricated (n=10). After 3 different surface pretreatments (polished, rough SiC P1200, or SiC P500), absolute translucency and surface roughness were measured using spectrophotometry and tactile profilometry. The influence of material type, thickness, and roughness on absolute translucency was analyzed using a multivariate analysis, 1-way ANOVA, and the Tukey HSD post hoc test (P<.05). Pearson correlations and statistical hypothesis tests were used to assess the results (P<.05). The effect of all tested parameters was significant among the materials (P<.05). The greatest influence on the measured translucency was thickness (partial eta squared ηP²=.988), closely followed by material (.982), and the pretreatment method (.835). The surface roughness was strongly influenced by the pretreatment method (.975) and type of material (.941). Thickness and surface roughness are major factors affecting the absolute translucency of adhesively luted restorations. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  16. Structure and Physical Properties of PZT-PMnN-PSN Ceramics Near the Morphological Phase Boundary

    Directory of Open Access Journals (Sweden)

    Nguyen Dinh Tung Luan

    2014-01-01

    Full Text Available The 0.9Pb(ZrxTi1−xO3-0.07Pb(Mn1/3Nb2/3O3-0.03Pb(Sb1/2Nb1/2O3 (PZT-PMnN-PSN ceramics were prepared by columbite method. The phase structure of the ceramic samples was analyzed. Results show that the pure perovskite phase is in all ceramics specimens. The effect of the Zr/Ti ratio on the region of morphotropic phase boundary for PZT-PMnN-PSN ceramics was studied. Experimental results show that the phase structure of ceramics changes from tetragonal to rhombohedral with the increase of the content of Zr/Ti ratio in the system. The composition of PZT-PMnN-PSN ceramics near the morphotropic phase boundary obtained is the ratio of Zr/Ti: 49/51. At this ratio, the ceramic has the optimal electromechanical properties: the kp=0.61, the εmax=29520, the d31=-236 pC/N, the Qm=2400, high remanent polarization (Pr=49.2 μC·cm−2, and low coercive field Ec=10.28 kV·cm−1.

  17. Piezoelectric response of a PZT thin film to magnetic fields from permanent magnet and coil combination

    Science.gov (United States)

    Guiffard, B.; Seveno, R.

    2015-01-01

    In this study, we report the magnetically induced electric field E 3 in Pb(Zr0.57Ti0.43)O3 (PZT) thin films, when they are subjected to both dynamic magnetic induction (magnitude B ac at 45 kHz) and static magnetic induction ( B dc) generated by a coil and a single permanent magnet, respectively. It is found that highest sensitivity to B dc——is achieved for the thin film with largest effective electrode. This magnetoelectric (ME) effect is interpreted in terms of coupling between eddy current-induced Lorentz forces (stress) in the electrodes of PZT and piezoelectricity. Such coupling was evidenced by convenient modelling of experimental variations of electric field magnitude with both B ac and B dc induction magnitudes, providing imperfect open circuit condition was considered. Phase angle of E 3 versus B dc could also be modelled. At last, the results show that similar to multilayered piezoelectric-magnetostrictive composite film, a PZT thin film made with a simple manufacturing process can behave as a static or dynamic magnetic field sensor. In this latter case, a large ME voltage coefficient of under B dc = 0.3 T was found. All these results may provide promising low-cost magnetic energy harvesting applications with microsized systems.

  18. Hybrid carbon-glass fiber/toughened epoxy thick composites subject to drop-weight and ballistic impacts

    Science.gov (United States)

    Sevkat, Ercan

    The goals of this study are to investigate the low velocity and ballistic impact response of thick-section hybrid fiber composites at room temperature. Plain-woven S2-Glass and IM7 Graphite fabrics are chosen as fiber materials reinforcing the SC-79 epoxy. Four different types of composites consisting of alternating layers of glass and graphite woven fabric sheets are considered. Tensile tests are conducted using 98 KN (22 kip) MTS testing machine equipped with environmental chamber. Low-velocity impact tests are conducted using an Instron-Dynatup 8250 impact test machine equipped with an environmental chamber. Ballistic impact tests are performed using helium pressured high-speed gas-gun. Tensile tests results were used to define the material behavior of the hybrid and non-hybrid composites in Finite Element modeling. The low velocity and ballistic impact tests showed that hybrid composites performance was somewhere between non-hybrid woven composites. Using woven glass fabrics as outer skin improved the impact performance of woven graphite composite. However hybrid composites are prone to delamination especially between dissimilar layers. The ballistic limit velocity V50 hybrid composites were higher that of woven graphite composite and lower than that of woven glass composite. Both destructive cross-sectional micrographs and nondestructive ultrasonic techniques are used to evaluate the damage created by impact. The Finite Element code LS-DYNA is chosen to perform numerical simulations of low velocity and ballistic impact on thick-section hybrid composites. The damage progression in these composites shows anisotropic nonlinearity. The material model to describe this behavior is not available in LS-DYNA material library. Initially, linear orthotropic material with damage (Chan-Chan Model) is employed to simulate some of the experimental results. Then, user-defined material subroutine is incorporated into LS-DYNA to simulate the nonlinear behavior. The

  19. Effect of composite resin polymerization modes on temperature rise in human dentin of different thicknesses: an in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Baggio Aguiar, Flavio Henrique; Kanda Peres Barros, Gisele; Alves Nunes Leite Lima, Debora; Bovi Ambrosano, Glaucia Maria; Lovadino, Jose Roberto [Piracicaba School of Dentistry, Campinas State University, Av. Limeira, 901, SP (Brazil)

    2006-09-15

    The aim of this in vitro study was to evaluate the effect of different polymerization modes on temperature rise in human dentin of different thicknesses, and to evaluate the relation between dentin thickness and temperature rise (TR). For this purpose, 60 specimens were assigned into 20 groups (n = 3): five polymerization modes (1-conventional; 2-soft-start; 3-high intensity; 4-ramp cure: progressive and high intensity; 5-high intensity with the tip of the light-curing unit at a distance of 1.3 cm for 10 s and the tip leaning on the sample) at four dentin thicknesses (0, 1, 2, 3 mm). During composite sample polymerization (2 mm), the temperature was measured by a digital laser thermometer (CMSS2000-SL/SKF). The statistical analyses were conducted by ANOVA (p = 0.05) and post-hoc Tukey's test. There were statistical differences of TR among polymerization modes and dentin thicknesses. The temperature rise was dependent on the polymerization mode and the dentin thickness: the thicker the dentin and the lower the polymerization mode energy, the lower the temperature rise.

  20. Influence of increment thickness on light transmission, degree of conversion and micro hardness of bulk fill composites.

    Science.gov (United States)

    Garoushi, Sufyan; Vallittu, Pekka; Shinya, Akikazu; Lassila, Lippo

    2016-09-01

    This study evaluated characteristics of light transmission, degree of monomer conversion and surface microhardness of bulk fill, conventional and fiber-reinforced resin based composites (RBCs) through different incremental thicknesses of resin composite. Working hypotheses was that there are differences in transmission of blue light through RBCs of different kinds and that the thickness of the increments influence the degree of monomer conversion of RBCs. Six bulk fill, three conventional nanohybrid, one short fiber reinforced and one flowable RBCs were evaluated. For each material, four different incremental thicknesses (1, 2, 3 and 4 mm) were considered (n = 5). The specimens were prepared in cylindrical Teflon molds that are open at the top and the bottom sides and cured for 40 s by applying the curing unit. After curing process, the specimens were ground with a silicon carbide paper with a grit size of 1200 and 4000, and then stored dry at 37 °C for 24 h. Light transmission, degree of monomer conversion, surface microhardness were measured and data were analyzed using ANOVA (p = 0.05). There were differences in light transmission of resin composites of various types and brands. Low-viscous bulk fill and short fiber-reinforced RBCs presented higher light transmission compared to resin composites of higher viscosity. Reduced light transmission and lower surface microhardness and DC % at bottom side of the specimen suggests that more attention needs to be paid to ensure proper curing of the resin composite in deep cavities.

  1. A Piezoelectric PZT Ceramic Mulitlayer Stack for Energy Harvesting Under Dynamic Forces

    Science.gov (United States)

    Xu, Tian-Bing; Siochi, Emilie J.; Kang, Jin Ho; Zuo, Lei; Zhou, Wanlu; Tang, Xiudong; Jiang, Xiaoning

    2011-01-01

    Piezoelectric energy harvesting transducers (PEHTs) are commonly used in motion/vibration energy scavenging devices. To date, most researchers have focused on energy harvesting at narrow bandwidths around the mechanical resonance frequency, and most piezoelectric harvesting devices reported in the literature have very low effective piezoelectric coefficient (d(sub eff)) (ceramic multilayer stack (PZT-Stack) with high effective piezoelectric coefficient for high-performance PEHTs. The PZT-Stack is composed of 300 layers of 0.1 mm thick PZT plates, with overall dimensions of 32.4 mm X 7.0 mm X 7.0 mm. Experiments were carried out with dynamic forces in a broad bandwidth ranging from 0.5 Hz to 25 kHz. The measured results show that the effective piezoelectric coefficient of the PZT-stack is about 1 X 10(exp 5) pC/N at off-resonance frequencies and 1.39 X 10(exp 6) pC/N at resonance, which is order of magnitude larger than that of traditional PEHTs. The effective piezoelectric coefficients (d(sub eff)) do not change significantly with applied dynamic forces having root mean square (RMS) values ranging from 1 N to 40 N. In resonance mode, 231 mW of electrical power was harvested at 2479 Hz with a dynamic force of 11.6 N(sub rms), and 7.6 mW of electrical power was generated at a frequency of 2114 Hz with 1 N(sub rms) dynamic force. In off-resonance mode, an electrical power of 18.7 mW was obtained at 680 Hz with a 40 N(sub rms) dynamic force. A theoretical model of energy harvesting for the PZT-Stack is established. The modeled results matched well with experimental measurements. This study demonstrated that high effective piezoelectric coefficient structures enable PEHTs to harvest more electrical energy from mechanical vibrations or motions, suggesting an effective design for high-performance low-footprint PEHTs with potential applications in military, aerospace, and portable electronics. In addition, this study provides a route for using piezoelectric multilayer

  2. Nonlinear Elastic Deformation of Thin Composite Shells of Discretely Variable Thickness

    Science.gov (United States)

    Lutskaya, I. V.; Maksimyuk, V. A.; Storozhuk, E. A.; Chernyshenko, I. S.

    2016-11-01

    A method for analyzing the stress-strain state of nonlinear elastic orthotropic thin shells with reinforced holes and shells of discretely variable thickness is developed. The reference surface is not necessarily the midsurface. The constitutive equations are derived using Lomakin's theory of anisotropic plasticity. The methods of successive approximations and variational differences are used. The Kirchhoff-Love hypotheses are implemented using Lagrange multipliers. The method allows analyzing the stress-strain state of shells with arbitrarily varying thickness and ribbed shells. The numerical results are presented in the form of tables and analyzed

  3. Dielectric properties of poly(vinylidene fluoride/CaCu3Ti4O12 nanocrystal composite thick films

    Directory of Open Access Journals (Sweden)

    2010-10-01

    Full Text Available The poly(vinylidene fluoride/CaCu3Ti4O12 (CCTO nanocrystal composite films (thickness ≈85 µm with relatively high dielectric permittivity (90 at 100 Hz were prepared by the solution casting followed by spin coating technique. The structural, the microstructural and the dielectric properties of the composites were studied using X-ray diffraction, Scanning Electron Microscope, and Impedance analyzer respectively. The effective dielectric permittivity (εeff of the composite increased with increase in the volume fraction of CCTO at all the frequencies (100 Hz to 1 MHz under investigation. The room temperature dielectric permittivity which is around 90 at 100 Hz, has increased to about 290 at 125°C (100 Hz. These results may be exploited in the development of high energy density capacitors.

  4. Standing wave brass-PZT square tubular ultrasonic motor.

    Science.gov (United States)

    Park, Soonho; He, Siyuan

    2012-09-01

    This paper reports a standing wave brass-PZT tubular ultrasonic motor. The motor is composed of a brass square tube with two teeth on each tube end. Four PZT plates are attached to the outside walls of the brass tube. The motor requires only one driving signal to excite vibration in a single bending mode to generate reciprocating diagonal trajectories of teeth on the brass tube ends, which drive the motor to rotate. Bi-directional rotation is achieved by exciting different pairs of PZT plates to switch the bending vibration direction. Through using the brass-PZT tube structure, the motor can take high magnitude vibration to achieve a high output power in comparison to PZT tube based ultrasonic motors. Prototypes are fabricated and tested. The dimension of the brass-PZT tube is 3.975mm×3.975mm×16mm. Measured performance is a no-load speed of >1000RPM, a stall torque of 370μNm and a maximum output power of 16 mW when a sinusoidal driving voltage of 50V is applied. The working frequencies of the motor are 46,050Hz (clockwise) and 46,200Hz (counter-clockwise).

  5. Physically Gelled Room-Temperature Ionic Liquid-Based Composite Membranes for CO2/N-2 Separation: Effect of Composition and Thickness on Membrane Properties and Performance

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, PT; Voss, BA; Wiesenauer, EF; Gin, DL; Nobe, RD

    2013-07-03

    An aspartame-based, low molecular-weight organic gelator (LMOG) was used to form melt-infused and composite membranes with two different imidazolium-based room-temperature ionic liquids (RTILs) for CO2 separation from N-2. Previous work demonstrated that LMOGs can gel RTILs at low, loading levels, and this aspartame-based LMOG was selected because it has been reported to gel a large number of RTILs. The imidazolium-based RTILs were used because of their inherent good properties for CO2/light gas separations. Analysis of the resulting bulk RTIL/LMOG physical gels showed that these materials have high sol-gel transition temperatures (ca. 135 degrees C) suitable for flue gas applications. Gas permeabilities and burst pressure measurements of thick, melt infused membranes revealed a trade-off between high CO2 permeabilities and good mechanical stability as a function of the LMOG loading. Defect-free, composite membranes of the gelled RTILs were successfully fabricated by choosing an appropriate porous membrane support (hydrophobic PTFE) using a suitable coating technique (roller coating). The thicknesses of the applied composite gel layers ranged from 10.3 to 20.7 mu m, which represents an order of magnitude decrease in active layer thickness, compared to the original melt-infused gel RTIL membranes.

  6. Nuchal Skinfold Thickness : A Novel Parameter for Assessment of Body Composition in Childhood Craniopharyngioma

    NARCIS (Netherlands)

    Sterkenburg, Anthe S.; Hoffmann, Anika; Reichel, Julia; Lohle, Kristin; Eveslage, Maria; Warmuth-Metz, Monika; Mueller, Hermann L.

    2016-01-01

    Context: Hypothalamic obesity, cardiovascular disease (CVD), and relapse/progression have a major impact on prognosis in childhood-onset craniopharyngioma (CP). We analyzed nuchal skinfold thickness (NST) on magnetic resonance imaging performed for follow-up monitoring as a novel parameter for body

  7. Global blending optimization of laminated composites with discrete material candidate selection and thickness variation

    DEFF Research Database (Denmark)

    Sørensen, Søren N.; Stolpe, Mathias

    2015-01-01

    to a distinct choice among predefined numbers of candidates. The laminate thickness is variable but the number of plies must be integer. We solve the convex mixed binary non-linear programming problem by an outer approximation cutting-plane method augmented with a few heuristics to accelerate the convergence...

  8. Nuchal Skinfold Thickness : A Novel Parameter for Assessment of Body Composition in Childhood Craniopharyngioma

    NARCIS (Netherlands)

    Sterkenburg, Anthe S.; Hoffmann, Anika; Reichel, Julia; Lohle, Kristin; Eveslage, Maria; Warmuth-Metz, Monika; Mueller, Hermann L.

    2016-01-01

    Context: Hypothalamic obesity, cardiovascular disease (CVD), and relapse/progression have a major impact on prognosis in childhood-onset craniopharyngioma (CP). We analyzed nuchal skinfold thickness (NST) on magnetic resonance imaging performed for follow-up monitoring as a novel parameter for body

  9. Influence of Cure Shrinkage on Process-Induced Stress and Deformation in Thick Thermosetting Composites

    Science.gov (United States)

    1992-07-01

    unidirectional composite micromechanics model The constituent fiber properties (constant), the resin properties and chemical shrinkage (cure dependent...during cure. Changes in the resin properties directly influence the mechanical properties in the composite, and chemical shrinkage represents a...xA (5) The expansion coefficients, otL and or, are based on the micromechanics model utilizing constant fiber properties. cure dependent resin

  10. Optimization of the fugitive coating thickness in pressure infiltrated mullite-alumina composites

    Energy Technology Data Exchange (ETDEWEB)

    Moore, E.H. [Wright Lab. Materials Directorate, Wright-Patterson Air Force Base, OH (United States); Shamasundar, S. [UES Inc., Dayton, OH (United States); Kroupa, J.L. [Univ. of Dayton Research Institute, Dayton, OH (United States)

    1995-12-01

    There is an increasing interest in oxide-oxide refractory composites and ceramic matrix composites (CMC) because of their high strength, high creep resistance and resistance to crack propagation in high-temperature structural and non-structural applications. High strength and low modulus oxide fibers are introduced into ceramic oxide matrices in order to resist crack growth (i.e., increase the composite`s strain to failure or {open_quotes}toughness{close_quotes}). Nevertheless, the introduction of a 2-D fibrous matte or 3-D fibrous preform into a ceramic matrix constrains the densification of the composite. (As a result, as prepared composite`s typically will have about 20 percent residual porosity.) Although higher densification is possible by free or pressure-less sintering, degradation of the mechanical properties of the fibers at elevated temperatures (e.g., normally above 1100{degrees}C for mullite fibers) prevents the application of high-temperature processing. An oxide-oxide composite composed of a high-purity alumina matrix and mullite; fibrous reinforcement has been used in this study. A fugitive carbon coating has been applied to 2-D fibrous mattes and 3-D preforms by chemical vapor deposition (CVD) and by polymer pyrolysis of a polymeric based resin system. This paper will only discuss the processing and applicable analysis of the CMC prepared with the applied polymeric pyrolyzed carbon coating.

  11. PZT Network and Phased Array Lamb Wave Based SHM Systems

    Energy Technology Data Exchange (ETDEWEB)

    Silva, C [Academia da Forca Aerea, Granja do Marques, 2715-021 Pero Pinheiro (Portugal); Rocha, B; Suleman, A, E-mail: cbsilva@emfa.pt [University of Victoria, Department of Mechanical Engineering, PO Box 3055, Stn.CSC, Victoria, BC, V8W 3P6 (Canada)

    2011-07-19

    With the application of newer materials, such as composite materials, and growing complexity and capacity of current aircraft structures, reliably and completely assess the condition of the total structures in real time is then of growing and utmost importance. PZT Network and Phased Array, Lamb wave based Structural Health Monitoring (SHM) systems were developed to be applied to thin panels. The selection of transducers, their size and selected locations for their installation are described. The development and selection of the signal generation and data acquisition systems is also presented in detail. The requirements conducing to the development and selection of these systems are laid and particularly the selection of the actuation signal applied is justified. The development of a damage detection algorithm based in the comparison of the current structural state to a reference state is described, to detect damage reflected Lamb waves. Such method was implemented in software and integrated in the SHM system developed. Subsequently the detection algorithm, based in discrete signals correlation, was further improved by incorporating statistical methods. For phased arrays, a novel damage location algorithm is presented based on the individual sensors response. A visualization method based concurrently in the statistical methods developed and superposition of the different results obtained from a test set was implemented. These tests conducted to the successful and repeatable detection of 1mm damages in a multiple damaged plate with great confidence. Finally, a brief comparison and a hybrid system implementation is presented.

  12. Piezoelectric and mechanical properties of structured PZT–epoxy composites

    NARCIS (Netherlands)

    Kunnamkuzhakkal James, N.; Van den Ende, D.; Lafont, U.; Van der Zwaag, S.; Groen, W.A.

    2013-01-01

    Structured lead zirconium titanate (PZT)–epoxy composites are prepared by dielectrophoresis. The piezoelectric and dielectric properties of the composites as a function of PZT volume fraction are investigated and compared with the corresponding unstructured composites. The effect of poling voltage o

  13. Amino Acid Composition, Urease Activity and Trypsin Inhibitor Activity after Toasting of Soybean in Thick and Thin Layer

    Directory of Open Access Journals (Sweden)

    Tajana Krička

    2009-12-01

    Full Text Available The objective of this study was to determine amino acid content, urease activity and trypsin inhibitor activity in soybean grain for polygastric animals’ feed aft er toasting with the aim to introduce thick layer in toasting technology. Hence, soybean was toasted both in thick and thin layer at 130 oC during 10 minutes. In order to properly monitor the technological process of soybean thermal processing, it was necessary to study crude protein content, urease activity, trypsin inhibitor activity and amino acid composition of soybean in natural and toasted samples. Results demonstrate that protein content in soybean toasted in thick and thin layer was found to be slightly increased while urease activity was reduced in relation to non-treated sample. Study also established a significant reduction of trypsin inhibitor activity aft er toasting, at higher extent in thin layer toasting. Amino acid content of soybean was slightly increased in relation to natural sample, as well as difference between amino acid content in samples toasted in thick and thin layers.

  14. X-ray physics- and bone composition-based estimation of thickness characteristics from clinical mandibular radiographs.

    Science.gov (United States)

    Scheiner, Stefan; Hellmich, Christian; Müller, Christoph; Bonitz, Lars; Kober, Cornelia

    2015-10-01

    In dentistry, clinical radiographs (also called X-ray images) reflect the intensity loss of an X-ray when being transmitted through the mandibular objects, and this loss is quantified in terms of grey values. While such images are standardly used for pathology detection by the experienced dentist, we here present a new method for getting more quantitative information out of such 2D radiographs, "extending" them into the third dimension. This "extension" requires consistent combination of X-ray physics (namely, X-ray intensity loss quantification along paths orthogonal to the panoramic clinical image and X-ray attenuation averaging for composite materials) with anatomically known upper and lower limits of vascular porosities in cortical and trabecular bone compartments. Correspondingly computed ranges of overall organ thicknesses are extremely narrow, suggesting adequate estimation of thickness characteristics from 2D radiographic panoramas used clinically, while predicted cortical and trabecular thickness ranges vary by ±8.47% and ±16.13%, respectively. The proposed method also identifies variations between thicknesses at similar anatomical locations left and right of the face's symmetry axis, and molar regions turn out to be thicker than those close to incisors. This paves the way to more detailed diagnostic activities, e.g. in combination with Finite Element simulations.

  15. The Influence of Irradiation Time and Layer Thickness on Elution of Triethylene Glycol Dimethacrylate from SDR® Bulk-Fill Composite

    Directory of Open Access Journals (Sweden)

    Ryta Łagocka

    2016-01-01

    Full Text Available Objective. This study aimed to evaluate triethylene glycol dimethacrylate (TEGDMA elution from SDR bulk-fill composite. Methods. Three groups of samples were prepared, including samples polymerized in a 4 mm layer for 20 s, in a 4 mm layer for 40 s, and in a 2 mm layer for 20 s. Elution of TEGDMA into 100% ethanol, a 75% ethanol/water solution, and distilled water was studied. The TEGDMA concentration was measured using HPLC. Results. The TEGDMA concentration decreased in the following order: 100% ethanol > 75% ethanol > distilled water. Doubling the energy delivered to the 4 mm thick sample caused decrease (p<0.05 in TEGDMA elution to distilled water. In ethanol solutions, the energy increase had no influence on TEGDMA elution. Decreasing the sample thickness resulted in decrease (p<0.05 in TEGDMA elution for all the solutions. Conclusions. The concentration of eluted TEGDMA and the elution time were both strongly affected by the hydrophobicity of the solvent. Doubling the energy delivered to the 4 mm thick sample did not decrease the elution of TEGDMA but did decrease the amount of the monomer available to less aggressive solvents. Elution of TEGDMA was also correlated with the exposed sample surface area. Clinical Relevance. Decreasing the SDR layer thickness decreases TEGDMA elution.

  16. A magnetoelectric composite based microwave phase shifter

    Science.gov (United States)

    Bichurin, M. I.; Petrov, V. M.; Srinivasan, G.

    2008-03-01

    Magnetoelectric (ME) properties of ferrite-ferroelectric composites arise from their response to elastic and electromagnetic force fields. The unique combination of magnetic, electrical, and ME interactions opens up the possibility of electric field tunable ferromagnetic resonance (FMR) based devices [1]. Here we discuss an ME phase shifter operating in the FMR region at 9.3 GHz. A slot line on a yttrium iron garnet film bonded to lead zirconate titanate (PZT) provides a basis for the phase shifter. The circularly polarized microwave magnetic field of the slot line interacts with the ferrite and causes variation of phase velocity with the controlling magnetic and electric fields. Electrical tuning is realized with the application of a control voltage due to PZT. The estimated phase shift per unit length and unit voltage is to 20 deg/cm kV for a PZT thickness of 0.5 mm. 1 S. Shastry and G. Srinivasan, M.I. Bichurin, V.M. Petrov, A.S. Tatarenko. Phys. Rev. B, 70 064416 (2004). - supported by grants from the Office of Naval Research and the Russian Foundation for Basic Research.

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

    Science.gov (United States)

    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.

  18. Effects of stitch density and stitch thread thickness on mode II delamination properties of Vectran stitched composites

    KAUST Repository

    Herwan, J.

    2014-11-01

    © Institute of Materials, Minerals and Mining 2014. Mode II delamination properties of Vectran stitched composites were investigated, and tabbed end notch flexural specimen testing was used to prevent premature failure. The effects of stitch density and stitch thread thickness were explored, and fibre compaction due to the stitching process was also verified. The results show that, in moderately stitched laminates (low stitch density), the improvement in GIIC was negligible. Crack bridging by the stitch threads at the crack zone were mostly compensated for the effect of fibre compaction, which reduced the GIIC values. Conversely, in densely stitched laminates (high stitch density), GIIC values were improved significantly (2·4 times higher than those of unstitched laminates). The effects of stitch thread thickness appeared to be negligible in moderately stitched laminates. For densely stitched laminates, thicker stitch thread (500 denier) possessed GIIC values that were 45·7% higher than thinner stitch thread (200 denier).

  19. The composition of reaction substrates for TiC carbides synthesis and its influence on the thickness of iron casting composite layer

    Directory of Open Access Journals (Sweden)

    E. Olejnik

    2011-04-01

    Full Text Available The effect of reaction substrates for the TiC carbide synthesis on the composite layer thickness produced in cast iron was examined. It was found that, at a constant weight of the charge amounting to 0.5 kg, changing the weight of the, placed in mould, stoichiometric mixture of titanium carbide (from 0.01 to 0.04 kg changed the thickness of the composite layer from 1 to 15 mm. Carbides synthesis starts directly in mould induced by the temperature of molten alloy poured into this mould (1700 K. The TiC carbides formed in this reaction are later, i.e. during alloy solidification, acting as a base composite material. The size of TiC carbides obtained in the synthesis is from 1 to 10 μm. They occur in the layers as locally compact and coagulated forms. Microstructure, chemical composition and structure of the obtained materials were tested by scanning electron microscopy (SEM, X-ray microanalysis (EDS, and X-ray diffraction (XRD.

  20. Thickness optimization of fiber reinforced laminated composites using the discrete material optimization method

    DEFF Research Database (Denmark)

    Sørensen, Søren Nørgaard; Lund, Erik

    2012-01-01

    This work concerns a novel large-scale multi-material topology optimization method for simultaneous determination of the optimum variable integer thickness and fiber orientation throughout laminate structures with fixed outer geometries while adhering to certain manufacturing constraints. The con......This work concerns a novel large-scale multi-material topology optimization method for simultaneous determination of the optimum variable integer thickness and fiber orientation throughout laminate structures with fixed outer geometries while adhering to certain manufacturing constraints....... The conceptual combinatorial/integer problem is relaxed to a continuous problem and solved on basis of the so-called Discrete Material Optimization method, explicitly including the manufacturing constraints as linear constraints....

  1. No linealidad en muestras cerámicas de PZT muy delgadas

    Directory of Open Access Journals (Sweden)

    de Frutos, J.

    1999-10-01

    Full Text Available The development of piezoelectric sensors for high frequency requires to work with very thin samples of material. At this thick nesses, the stress concentration produces strong perturbations in the materials, and the origin oF a non linear response, which depends field on working conditions. With the goal to advance in the knowledgement of this phenomenon, and by using Complex Impedance Spectroscopy, we have analysed the response of PZT ceramics with thickness of microns as a function of the applied and the amplitude of the analysis signal. These results allow to establish the base to the development of ultrasonic tunable sensors for high frequency.

    El desarrollo de sensores piezoeléctricos de alta frecuencia, exige trabajar con muestras de material muy delgadas, del orden de micras. En estos espesores, las tensiones de trabajo causan fuertes perturbaciones en los materiales, provocando respuestas no lineales, sumamente dependientes de las condiciones de trabajo. Con el objetivo de avanzar en el conocimiento de este fenómeno, y haciendo uso de la técnica de Espectroscopia de Impedancia Compleja, hemos analizado la respuesta de muestras de PZT cerámico adelgazadas a espesores de micras, en función del campo aplicado y de la amplitud de la señal de análisis. El estudio de estos resultados, puede permitir sentar las bases para el desarrollo de sensores ultrasónicos de alta frecuencia sintonizables.

  2. Body composition of anorexia nervosa patients assessed by underwater weighing and skinfold-thickness measurements before and after weight gain.

    Science.gov (United States)

    Probst, M; Goris, M; Vandereycken, W; Van Coppenolle, H

    2001-02-01

    Weight restoration is a crucial element in the treatment of patients with anorexia nervosa. Therefore, the validity of different methods for measuring body composition is important. We tested the concurrent validity of hydrodensitometry (underwater weighing) and anthropometry (12 skinfold thicknesses) and assessed body composition and subcutaneous fat before and after a refeeding program and a multifaceted program of therapy in a specialized inpatient unit for eating disorders. The body composition of a large sample of anorexia nervosa patients (97 restricting type, 33 binging-purging type) was studied by using 2 methods both before and after weight gain. We applied a behavioral contract for weight restoration with a minimum weekly gain of 700 g and a maximum of 3 kg. Bland-Altman analysis of agreement, Pearson correlation analysis, t tests, and analysis of covariance were used. There was good agreement between the results obtained by underwater weighing and by skinfold-thickness measurement (r = 0.76, P < 0.001); the results produced by the 2 methods did not differ significantly. On average, a significant weight gain (11.9 kg) was observed, composed of 6.6 kg fat and 5.3 kg fat-free mass. Body fat estimation by skinfold-thickness equation appeared to be as accurate as underwater weighing. The refeeding program led to a significant increase in body weight, of which 55.5% was body fat. The mean ratio of fat-free mass to fat mass at the end of the treatment was 3.4:1.

  3. Ballistic Simulation Method for Lithium Ion Batteries (BASIMLIB) Using Thick Shell Composites (TSC) in LS-DYNA

    Science.gov (United States)

    2016-08-04

    Statement A. Approved for public release. Distribution is unlimited BASIMLIB – Bullet model  NATO 0.308 caliber full metal jacket with 7.62 mm in...test  DEFINE_ADAPTIVE_SOLID_TO_SPH is activated to capture the fragmenting bullet particles NATO 0.308 Caliber bullet model Brass Jacket Steel Core...51mm Full Metal Jacket 2500 FPS (762 m/s ) Velocity Two Cell Pack (Thick Shell Composite M&S M&S Test Test Aluminum cell separator penetrated

  4. Novel Composite Thick-Film Electrodes Consisted of Zinc Oxide and Silicon for Lithium-Ion Battery Anode

    OpenAIRE

    Usui, Hiroyuki; Kono, Takamasa; Sakaguchi, Hiroki

    2012-01-01

    As a novel anode for Li-ion battery, ZnO/Si composite thick-film electrodes with various ratios of ZnO:Si were prepared by a gas-deposition method using a commercial Si powder and a radial-shaped ZnO powder synthesized by a precipitation method. We investigated the effect of the ZnO amount and the radial morphology on the anode performance, comparing with charge–discharge properties of a ZnO electrode without Si. The ZnO electrode showed a stable cyclability and a moderate discharge capacity ...

  5. Monte Carlo Simulation Study of Diffuse Scattering in PZT, Pb(Zr,Ti)O3

    Science.gov (United States)

    Welberry, T. R.; Goossens, D. J.; Withers, R. L.; Baba-Kishi, K. Z.

    2010-05-01

    Transverse polarized diffuse streaks have been observed in diffraction patterns of Pb(Zr1- x Ti x )O3 (PZT) ceramics for compositions ranging from x = 0.3 (rhombohedral phase) to x = 0.7 (tetragonal phase) including the important morphotropic phase boundary (MPB) region ( x = 0.48). The streaks correspond to diffuse planes of scattering in three dimensions, and these are oriented normal to the (cubic) piezo-electric properties of the material, but its presence requires the currently accepted models for the average structure to be reassessed.

  6. Utlrasonic welding of thermoplastic composites with flat energy directors: Influence of the thickness of the energy director on the welding process

    NARCIS (Netherlands)

    Palardy, G.; Fernandez Villegas, I.

    2015-01-01

    This paper presents a detailed experimental examination of the influence of the thickness of flat energy directors (ED) on the ultrasonic welding (USW) process for carbon fibre/polyetherimide composites. Three thicknesses of flat ED were compared: 0.06 mm, 0.25 mm and 0.50 mm. Power and displacement

  7. Ultrasonic welding of thermoplastic composites with flat energy directors: Influence of the thickness of the energy director on the welding process

    NARCIS (Netherlands)

    Palardy, G.; Fernandez Villegas, I.

    2015-01-01

    This paper presents a detailed experimental examination of the influence of the thickness of flat energy directors (ED) on the ultrasonic welding (USW) process for carbon fibre/polyetherimide composites. Three thicknesses of flat ED were compared: 0.06 mm, 0.25 mm and 0.50 mm. Power and displacement

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

    Science.gov (United States)

    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.

  9. Electrical excitation and optical detection of ultrasounds in PZT based piezoelectric transducers

    Energy Technology Data Exchange (ETDEWEB)

    Babilotte, P; Diallo, O; Hue, L-P Tran Hu; Feuillard, G [University Francois Rabelais de Tours, Laboratory Imaging and Brain, Team Ultrasonic Characterisation and Piezoelectricity, ENIVL, Rue de la Chocolaterie, 41034 BLOIS CEDEX (France); Kosec, M; Kuscer, D, E-mail: philippe.babilotte@univ-tours.fr [Josef Stefan Institute, Jamova cesta 39, 1000 LJUBLJANA (Slovenia)

    2011-01-01

    The displacement response of piezoelectric PZT thick films fabricated by means of electrophoretic deposition and laid down an alumina substrate is investigated using coherent optical detection. According to thickness properties determined by electrical impedance measurements, the film presents a resonance around 40 MHz. Other resonance peaks are observed that correspond to eigen modes of the film substrate couple structure. Uniformity of the response of the integrated structure is studied across the surface of the sample when excited by either a continuous or impulse electrical voltage. Results on the amplitude of the detected signal versus the frequency and the input excitation voltage are reported. The optical detection used in these experiments is complementary to conventional techniques of characterization of piezoelectric devices such as electrical impedance measurements and allows getting information on the displacement response of the device.

  10. Effects of composition and layer thickness of a butyl acrylate/acrylic acid copolymer on the adhesion properties

    Energy Technology Data Exchange (ETDEWEB)

    Ghim, Deoukchen; Kim, Jung Hyeun [University of Seoul, Seoul (Korea, Republic of)

    2016-02-15

    Acrylic pressure-sensitive adhesives are synthesized by solution copolymerization using n-butyl acrylate and acrylic acid (AA) in ethyl acetate anhydrous. The copolymer composition is controlled for good adhesive properties by varying AA content. The monomer conversion is measured by the gravimetric method and FTIR technique. The adhesive layer thickness is measured by scanning electron microscopy, and the adhesive properties are evaluated with loop tack, 180 .deg. peel, and holding time measurements. The peel force increases with increasing the AA content up to 3 wt% and decreases at the AA content higher than 3 wt%, but the tack force decreases with increasing the AA content. The holding time increases with increasing the AA content, and it shows a similar trend with the T{sub g} of adhesives. The increase of layer thickness improves tack and peel forces, but it weakens the holding power. A tape thickness of about 20 μm shows well-balanced properties at 3 wt% AA content in the acrylic copolymer system.

  11. Combining Through-Thickness Reinforcement and Self-Healing for Improved Damage Tolerance and Durability of Composites

    Science.gov (United States)

    O'Brien, T. Kevin; Czabaj, Michael W.; Hinkley, Jeffrey A.; Tsampas, Spiros; Greenhalgh, Emile S.; McCombe, Gregory; Bond, Ian P.; Trask, Richard

    2013-01-01

    A study was undertaken to develop a prototype method for adding through-thickness hollow glass tubes infused with uncured resin and hardener in a carbon Z-pin through-thickness reinforcement field embedded in a composite laminate. Two types of tube insertion techniques were attempted in an effort to ensure the glass tubes survived the panel manufacturing process. A self-healing resin was chosen with a very low viscosity, two component, liquid epoxy resin system designed to be mixed at a 2-to-1 ratio of epoxy to hardener. IM7/8552 carbon epoxy double cantilever beam (DCB) specimens were cut from the hybrid Z-pin and glass tube reinforced panels and tested. In-situ injection of resin and hardener directly into glass tubes, in a staggered pattern to allow for 2-to-1 ratio mixing, resulted in partial healing of the fracture plane, but only if the injection was performed while the specimen was held at maximum load after initial fracture. Hence, there is some potential for healing delamination via resin and hardener delivered through a network of through-thickness glass tubes, but only if the tubes are connected to a reservoir where additional material may be injected as needed.

  12. Effect of annealing on composition, structure and electrical properties of Au layers grown on different thickness Cr layers

    Institute of Scientific and Technical Information of China (English)

    Yan Huang; Hong Qiu; Liqing Pan; Yue Tian; Fengping Wang; Ping Wu

    2004-01-01

    110 nm-thick Au layers were sputter-deposited on unheated glasses coated about a 10 nm-thick and a 50 nm-thick Cr layer respectively. The Au/Cr bilayer films were annealed in a vacuum of 1 mPa at 300℃ for 2, 5 and 30 min, respectively. Auger electron spectroscopy, X-ray diffraction and Field emission scanning electron microscopy were used to analyze the composition and structure of the Au layers. The resistivity of the bilayer films was measured by using four-point probe technique. The adhesion of the bilayer films to the substrate was tested using tape tests. The amount of Cr atoms diffusing into the Au layer increases with increasing the annealing time, resulting in a decrease in lattice constant and an increase in resistivity of the Au layer. The content of Cr inside the Au layer grown on the thinner Cr layer is less than that grown on the thicker Cr layer. For the Au/Cr bilayer films, the lower resistivity and the good adhesion to the glass substrate can be obtained at a shorter annealing time for a thinner Cr layer.

  13. Flexible PZT Thin Film Tactile Sensor for Biomedical Monitoring

    Directory of Open Access Journals (Sweden)

    Wen-Jong Wu

    2013-04-01

    Full Text Available This paper presents the development of tactile sensors using the sol-gel process to deposit a PZT thin-film from 250 nm to 1 μm on a flexible stainless steel substrate. The PZT thin-film tactile sensor can be used to measure human pulses from several areas, including carotid, brachial, finger, ankle, radial artery, and the apical region. Flexible PZT tactile sensors can overcome the diverse topology of various human regions and sense the corresponding signals from human bodies. The measured arterial pulse waveform can be used to diagnose hypertension and cardiac failure in patients. The proposed sensors have several advantages, such as flexibility, reliability, high strain, low cost, simple fabrication, and low temperature processing. The PZT thin-film deposition process includes a pyrolysis process at 150 °C/500 °C for 10/5 min, followed by an annealing process at 650 °C for 10 min. Finally, the consistent pulse wave velocity (PWV was demonstrated based on human pulse measurements from apical to radial, brachial to radial, and radial to ankle. It is characterized that the sensitivity of our PZT-based tactile sensor was approximately 0.798 mV/g.

  14. In-Situ Composition and Luminescence of Europium and Terbium Coordination Polymers/PEMA Hybrid Thick Films

    Institute of Scientific and Technical Information of China (English)

    YAN Bing; WANG Qianming

    2005-01-01

    Europium and terbium coordination polymers of pyridine- 3-carboxylic acid were in-situ composed with ethyl methacrylate ( EMA ). With the polymerization of EMA monomer and the formation of europium and terbium coordination polymers of pyridine- 3-carboxylic acid, the transparent hybrid thick films composed of [Eu( NIC)3 ]n ( [ Tb( NIC)3 ]n ) and poly ethyl methacrylate ( PEMA ) have been prepared. The luminescence properties and energy transfer of these polymeric composites were studied with absorption spectra, fluorescent excitation and emission spectra in detail. All the hybrid thick films composed of terbium coordination polymer show the characteristic strong green emission of terbium ions, which implies the same energy transfer mechanism as the pure complex and the hybrid composite film is a suitable substrate for the luminescence of terbium ions. In the range of composing concentration of luminescent species (0.01,0.025,0.05,0.1 mmol/15 mL EMA ) , emission intensities increase with the increasing of corresponding composing concentration and the concentration quenching effect does not take place.

  15. Thermal effect on dynamics of thin and thick composite laminated microbeams by modified couple stress theory for different boundary conditions

    Science.gov (United States)

    Ghadiri, Majid; Zajkani, Asghar; Akbarizadeh, Mohammad Reza

    2016-12-01

    In this article, thermal effect on free vibration behavior of composite laminated microbeams based on the modified couple stress theory is presented. The proposed anisotropic model is developed by using a variational formulation. The governing equations and boundary conditions are obtained based on a modified couple stress theory and using the principle of minimum potential energy and considering different beam theories, i.e., Euler-Bernoulli, Timoshenko and Reddy beam theories. Unlike the classical beam theories, this model contains a material length scale parameter and can capture the size effect. Free vibration of a simply supported beam is solved by utilizing Fourier series. In addition, the fundamental frequency is achieved by using the generalized differential quadrature method for four types of cross-ply laminations with clamped-clamped, clamped-hinged and hinged-hinged boundary conditions for different beam theories. For investigating different parameters including temperature changes, material length scale parameter, beam thickness, some numerical results on different cross-ply laminated beams are presented. The fundamental frequency of different thin and thick beam theories is investigated by increasing slenderness ratio and thermal loads. The results prove that the modified couple stress theory increases the natural frequency under the thermal effects for free vibration of composite laminated microbeams.

  16. A novel multi-degree-of-freedom thick-film ultrasonic motor.

    Science.gov (United States)

    Aoyagi, Manaba; Beeby, Steve P; White, Neil M

    2002-02-01

    This paper describes a new multi-degree-of-freedom (MDOF) ultrasonic motor that comprises few parts and is based on low-cost thick-film technology. Conventional ultrasonic motors using bulk lead zirconate titanate (PZT) or thin-film PZT layers are relatively expensive at the present time. Thick-film printed PZT technology provides the opportunity to reduce the costs of ultrasonic motors. To demonstrate the feasibility of this approach, an ultrasonic motor was fabricated from alumina using thick-film printed PZT actuators. The thick-film PZT and electrode layers were printed on a thin alumina plate, and a tiny cylinder was mounted at its center. This cylinder magnifies the lateral displacement of the stator, holds the spherical rotor, and transmits the driving force to the sphere. Three bending vibrations, B22, B30, B03, of the plate were applied to rotate the sphere. Sufficient displacements for rotating the sphere were obtained near the resonance of B22 by applying an excitation voltage of 200 V peak-to-peak via a three-phase drive circuit. Rotations in three orthogonal directions have been observed by controlling the phase of the driving signal to the PZT electrodes, and a MDOF ultrasonic motor was successfully realized.

  17. Synthesis of piezoelectric nanocrystalline PZT powder by stearic acid gel method

    Institute of Scientific and Technical Information of China (English)

    HAO Junjie; WANG Xiaohui; GUI Zhilun; LI Longtu

    2005-01-01

    PZT nanocrystalline powder was prepared by a stearic acid gel method. The crystallization process from the precursor was monitored by infrared spectroscopy, differential thermal analysis, and thermogravimetric analysis. The nano-sized PZT powder was characterized by X-ray diffraction and transmission electron microscopy. It shows that pure single-phase PZT powder could be obtained at 450℃ for 1 h, and the particle size is about 20 nm. With an increase in the calcination temperature, the PZT crystallite size increased.

  18. Sol-gel PZT and Mn-doped PZT thin films for pyroelectric applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Q. [Advanced Materials Group, School of Industrial and Manufactory Science, Cranfield University, Beds (United Kingdom)]. E-mail: q.zhang@cranfield.ac.uk; Whatmore, R.W. [Advanced Materials Group, School of Industrial and Manufactory Science, Cranfield University, Beds (United Kingdom)

    2001-08-07

    Thin films of ferroelectric lead zirconate titanate (PbZr{sub 0.3}Ti{sub 0.7}O{sub 3} PZT30/70) and manganese-doped lead zirconate titanate ((Pb(Zr{sub 0.3}Ti{sub 0.7}){sub 1-x}Mn{sub x})O{sub 3}, where x=0.01, PM01ZT30/70; and x=0.03, PM03ZT30/70) have been prepared using sol-gel processing techniques. These materials can be used as the pyroelectric thin films in uncooled infrared detectors. The thin films were prepared via a sol-gel route based on a hybrid solvent of methanol and ethanol with acetic acid, ethanolamine and ethylene glycol as additives. The final solution is non-moisture sensitive and stable. Films deposited on Pt/Ti/SiO{sub 2}/Si substrates and annealed on a hot plate at 500-530{sup 0}C for a few minutes were seen to fully crystallize into the required perovskite phase and showed excellent ferroelectric behaviour, demonstrated by reproducible hysteresis loops (P{sub r}=33-37 {mu}C cm{sup -2}, Ec(+)=70-100 kV cm{sup -1}, Ec(-)=-170 to -140 kV cm{sup -1}). The pyroelectric coefficient (p) was measured using the Byer-Roundy method. At 20 deg. C, p was 2.11x10{sup -4} C m{sup -2} K{sup -1} for PZT30/70, 3.00x10{sup -4} C m{sup -2} K{sup -1} for PM01ZT30/70 and 2.40x10{sup -4} C m{sup -2} K{sup -1} for PM03ZT30/70 thin films. The detectivity figure-of-merit (F{sub D}) was 1.07x10{sup -5} Pa{sup -0.5} for PZT30/70, 3.07x10{sup -5} Pa{sup -0.5} for PM01ZT30/70 and 1.07x10{sup -5} Pa{sup -0.5} for PM03ZT30/70. These figures compare well with values reported previously. (author)

  19. Modeling of PZT Ferroelectric Ceramic Depolarization Driven by Shock Stress

    Institute of Scientific and Technical Information of China (English)

    LAN Chao-Hui; PENG Yu-Fei; LONG Ji-Dong; WANG Qiang; WANG Wen-Dou

    2011-01-01

    @@ Shock-induced phase transition of ferroelectric ceramic PZT 95/5 causes elastic stiffening and depolarization,releasing stored electrostatic energy into the load circuit.We develop a model to describe the response of the PZT ferroelectric ceramic and implement it into simulation codes.The model is based on the phenomenological theory of phase transition dyynamics and takes into account the effects of the self-generated intensive electrical field and stress.Connected with the discharge model and external circuit, the whole transient process of PZT ceramic depoling can be investigated.The results show the finite transition velocity of the ferroelectric phase and the double wave structure caused by phase transition.Simulated currents are compared with the results from experiments with shock pressures varying from 0.4 to 2.8GPa.

  20. Body composition and prediction equations using skinfold thickness for body fat percentage in Southern Brazilian adolescents.

    Science.gov (United States)

    Ripka, Wagner Luis; Ulbricht, Leandra; Gewehr, Pedro Miguel

    2017-01-01

    The purpose of this study was to: a) determine the nutritional status of Brazilian adolescents, and; b) present a skinfold thickness model (ST) to estimate body fat developed with Brazilian samples, using dual energy x-ray absorptiometry (DXA) as reference method. The main study group was composed of 374 adolescents, and further 42 adolescents for the validation group. Weight, height, waist circumference measurements, and body mass index (BMI) were collected, as well as nine ST-biceps (BI), triceps (TR), chest (CH), axillary (AX) subscapularis (SB), abdominal (AB), suprailiac (SI), medial thigh (TH), calf (CF), and fat percentage (%BF) obtained by DXA. The prevalence of overweight in adolescents was 20.9%, and obesity 5.8%. Regression analysis through ordinary least square method (OLS) allowed obtainment of three equations with values of R2 = 0.935, 0.912 and 0.850, standard error estimated = 1.79, 1.78 and 1.87, and bias = 0.06, 0.20 and 0.05, respectively. the innovation of this study lies in presenting new regression equations for predicting body fat in Southern Brazilian adolescents based on a representative and heterogeneous sample from DXA.

  1. Uric acid, carotid intima-media thickness and body composition in prepubertal children.

    Science.gov (United States)

    Bassols, J; Martínez-Calcerrada, J M; Prats-Puig, A; Carreras-Badosa, G; Díaz-Roldán, F; Osiniri, I; Riera-Pérez, E; de Zegher, F; Ibáñez, L; López-Bermejo, A

    2016-10-01

    Increased uric acid is an independent biomarker for cardiovascular disease in obese adolescents and adults. We investigated whether uric acid relates to carotid intima-media thickness (cIMT) in prepubertal children, and whether body mass index (BMI) and preperitoneal fat modulate this association. 359 asymptomatic prepubertal Caucasian children were stratified according to BMI categories (171 with BMI-SDS 50th centile). Uric acid levels, insulin resistance (homeostasis model assessment insulin resistance; HOMA-IR), C-reactive protein (CRP), triacylglycerol (TG), systolic blood pressure (SBP), abdominal fat and cIMT (both by ultrasound) were assessed. Uric acid was associated with several cardiovascular risk factors, namely higher HOMA-IR, CRP, TG, BMI, waist, SBP, preperitoneal fat and cIMT (all P uric acid and cIMT (both P uric acid was preferentially related to cIMT in heavier children (β = 0.247, P uric acid is associated with cIMT in asymptomatic prepubertal children. Both higher BMI and preperitoneal fat aggravate the potential risk of atherosclerotic disease imposed by higher concentrations of uric acid. © 2015 World Obesity.

  2. Powering low-power implants using PZT transducer discs operated in the radial mode

    Science.gov (United States)

    Sanni, Ayodele; Vilches, Antonio

    2013-11-01

    This paper reports experimental results that are used to compare operation characteristics of lead zirconate titanate (PZT) piezoelectric ceramic discs operated in the radial mode. The devices are driven to radially vibrate at their lowest fundamental resonant frequency and thus transmit and receive power when immersed in a liquid phantom. A number of 1 mm × 10 mm (thickness × diameter) PZT discs are characterized experimentally within a propagation tank and results discussed. On the basis of these measured characteristics, a novel application is developed and reported for the first time. This consists of a tuned LC resonator circuit which is used at the receiving disc to maximize sensitivity as well as a Seiko start-up IC S-882Z which is employed to charge a capacitor that drives a PIC microcontroller (μC) once the voltage exceeds 2 V DC. We show that a mean input power of 486 mW RMS results in 976 μW RMS received over a range of 80 mm and that this is sufficient to periodically (every 60 s) power the μC to directly drive a red LED for 5 ms with a current of 4.8 mA/flash. This approach is suitable for low-power, periodically activated analogue bio-implant applications.

  3. Reliability of vibration energy harvesters of metal-based PZT thin films

    Science.gov (United States)

    Tsujiura, Y.; Suwa, E.; Kurokawa, F.; Hida, H.; Kanno, I.

    2014-11-01

    This paper describes the reliability of piezoelectric vibration energy harvesters (PVEHs) of Pb(Zr,Ti)O3 (PZT) thin films on metal foil cantilevers. The PZT thin films were directly deposited onto the Pt-coated stainless-steel (SS430) cantilevers by rf-magnetron sputtering, and we observed their aging behavior of power generation characteristics under the resonance vibration condition for three days. During the aging measurement, there was neither fatigue failure nor degradation of dielectric properties in our PVEHs (length: 13 mm, width: 5.0 mm, thickness: 104 μm) even under a large excitation acceleration of 25 m/s2. However, we observed clear degradation of the generated electric voltage depending on excitation acceleration. The decay rate of the output voltage was 5% from the start of the measurement at 25 m/s2. The transverse piezoelectric coefficient (e31,f) also degraded with almost the same decay rate as that of the output voltage; this indicates that the degradation of output voltage was mainly caused by that of piezoelectric properties. From the decay curves, the output powers are estimated to degrade 7% at 15 m/s2 and 36% at 25 m/s2 if we continue to excite the PVEHs for 30 years.

  4. ELABORATION AND DIELECTRIC CHARACTERIZATION OF A DOPED FERROELECTRIC MATERIAL TYPE PZT

    Directory of Open Access Journals (Sweden)

    M. Abba

    2015-07-01

    Full Text Available The main objective of this work is based on the synthesis and dielectric characterization of a new material in ceramic PZT with a perovskite structure ABO3. We are interested to study the Quaternary system (doping in site A and site B of general formula: Pb0.96Ba0.02Ca0.02[(Zr0.52Ti0.480.94(Zn1/3Ta2/30.03(In1/3Sb2/30.03]O3 short PZT-PBC-ZTIS. The sample selected for this study was prepared by the method of synthesis with solid way. Heat treatment was applied to these compositions at different temperatures: 1100, 1150,1180 and 1200 °C successively to optimize the sintering temperature optimal where the density of the sample is maximum (near theoretical density and therefore the product has better physical quality. The study of dielectric properties of all samples showed a high permittivity dielectric εr = 18018, low dielectric loss: tgδ = 7.62%, for the composition sintered to 1180 ° C included in the phase morphotropique zone (FMP.

  5. Using microwave for processing nanostructured PZT ceramics; Utilizacao de microondas no processamento de ceramicas nanoestruturadas de PZT

    Energy Technology Data Exchange (ETDEWEB)

    Lanza, A.C.; Berti, T.G.; Thomazini, D.; Gelfuso, M.V., E-mail: lanza.work@gmail.com [Universidade Federal de Itajuba (UNIFEI), MG (Brazil). Instituto de Engenharia Mecanica; Eiras, J.A. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Dept. de Fisica

    2012-07-01

    The PZT ceramics have dielectric and piezoelectric properties of technological interest. The method of microwave assisted hydrothermal synthesis becomes interesting since it occurs in a closed environment, the low temperature and time, compared to conventional methods. In this work, PZT powders were dissolved in acid medium, and by adjusting the pH of the solutions obtained were precipitated, subjected to hydrothermal treatment at 120 °C for intervals of 15, 30 and 60 min. The powders were characterized by differential thermal and gravimetric analysis, X-ray diffraction and scanning electron microscopy. The results confirm the formation of PZT phase in one hour with particle size around 55 nm, showing the feasibility of the proposed method. (author)

  6. PERFORMANCE, COMBUSTION AND EMISSION CHARACTERISTICS OF PZT LOADED CYANATE MODIFIED EPOXY COATED COMBUSTION CHAMBER IN DIESEL ENGINE

    Directory of Open Access Journals (Sweden)

    Vijaya Kumar K.R

    2010-07-01

    Full Text Available Energy conservation and emissions have become increasing concern over the past few decades. PZT loaded cyanate modified epoxy (60EPCY 20PI coated material were initially investigated for adiabatic diesel engines based on first law of thermodynamics prediction of significant fuel economy improvements, reduction in heat rejection and potential increased power density of the diesel engines. The purpose of 60EPCY 20PI is to focus on developing binder systems with low thermal conductivity and improve the coating durability under high load condition. The coating material is made up of 20% Lead Zirconate Titanate (PZT in 60% Cyanate modified Epoxy system. The triazine ring of cyanate ester offers better thermal resistance characteristics to the epoxy system. Experimental investigation is carried out under different load condition on a single cylinder dieselengine with PZT loaded cyanate modified epoxy resin system of 0.5 mm thickness to the piston, cylinder head with valves and cylinder liner. The result showed 15.89 %of reduced specific fuel consumption. Emissions of unburnt hydrocarbon, carbon monoxide are reduced.

  7. Novel sensing approach for LPG leakage detection: Part II: Effects of particle size, composition and coating layer thickness

    KAUST Repository

    Mukhopadhyay, Subhas

    2015-10-30

    Prominent research has been going on to develop a low-cost, efficient gas sensing system. The paper presents a continuation of our earlier research work done to develop a new sensing approach for gas detection at ambient conditions. The work exhibits the optimization of the response time of the sensor by inhabiting characteristic changes like variation in the concentration of the dispersion medium, thickness of the coating and the size of the dispersed medium. Different concentrations of the dispersion medium in the coated suspension were tested to determine the optimal composition required to achieve the highest sensitivity of the tin oxide (SnO2) layer towards the tested gas. The control over adsorption and desorption of the gas molecules in the coated layer was achieved by investigating the particle size of the dispersed medium. The response time of the coated sensor was encouraging and owns a promising potential to the development of a more efficient gas sensing system.

  8. Synthesis and characterization of tungsten or calcium doped PZT ceramics; Sintese e caracterizacao do PZT dopado com W ou Ca

    Energy Technology Data Exchange (ETDEWEB)

    Santos, D.M.; Caracas, L.B.; Noronha, R.G.; Santos, M.M.T. dos [Universidade Federal do Maranhao (UFMA), Sao Luis, MA (Brazil). Dept. de Desenho e Tecnologia. Curso de Desenho Industrial; Paiva-Santos, C.O., E-mail: denilson@ufma.b [Universidade Estadual Paulista (IQ/UNESP), Araraquara, SP (Brazil). Inst. de Quimica

    2009-07-01

    Pure and doped (tungsten or calcium) PZT ceramics were prepared by association of the polymeric precursor and partial oxalate method. The phase formation was investigated by thermal analysis (TG/DSC) and X-ray diffraction (XRD). The affect of W or Ca doping PZT and their electrical properties was evaluated. Substitution of W by Ti and Ca by Pb leads to an increase of Curie temperature and broadening of dielectric constant. A typical hysteresis loop was observed at room temperature and the remnant polarization was increased with the content of W and Ca. (author)

  9. Synthesis of PZT power by wet-dry method and its structure

    Institute of Scientific and Technical Information of China (English)

    汤卉; 王佳; 高维丽

    2008-01-01

    To prepare PZT powder at lower temperature, lead zirconate titanate (PZT) powder (x(Zr)/x(Ti)=56?44) was prepared by wet-dry method. Glycol was used as the solvent, and zirconium oxychloride was used as zirconium source. The properties and structure of the powder were analyzed by XRD, SEM and Sedimentograph. The effects of sintering parameter such as sintering temperature, keeping time and heating-up velocity on structure of PZT power were investigated. The results show that homogeneous PZT with single-phase perovskite structure can be obtained after sintering at 730 ℃ for 2 h, and the average size of PZT powder is about 113 nm.

  10. Preparation and Characterization of PZT films Fabricated on Si Substrate

    Institute of Scientific and Technical Information of China (English)

    YANG Ying

    2006-01-01

    Lead zirconium titanate (PZT) films (Zr/Ti=45:55)with a high dielectric constant are prepared successfully on the low-resistance Si substrate in sol-gel dip-coating process with PT film used as the buffer layer.The dielectric and ferroelectric properties of the films as well as the relationship between crystallization and preparing condition are studied.It is shown that the PZT ferroelectric thin films with a (110) preferred orientation and a well-crystallized perovskite structure could be obtained after annealing at 800℃ for 15 min.The particle size of the sample is about 14-25 nm.The P-E hysteresis loops are measured by means of the Sawyer-Tower test system with a compensation resistor at room temperature.The remanent polarization (Pr) and coercive electric field (Ec) of the measured PZT thin films are 47.7 μC/cm2 and 18 kV/cm,respectively.The relative dielectric constant εr and the dissipation factor tgδ of the PZT thin films were measured with an LCR meter and were found to be 158 and 0.04-0.005,respectively.

  11. Specific Heat, Charge Release and Dielectric Constant of PZT Ceramics

    NARCIS (Netherlands)

    Cereceda, N.; Noheda, B.; Gonzalo, J.A.; Mielcarek, S.; Mroz, B.

    1998-01-01

    Dielectric constant, specific heat and charge release measurements have been performed to study the FRL-FRH and FRH-PC phase transitions in Zr rich PZT (PbZr1-xTixO3). Both transitions have been described together by means of a two order parameters effective field model, in order to include the

  12. Effect of External Vibration on PZT Impedance Signature.

    Science.gov (United States)

    Yang, Yaowen; Miao, Aiwei

    2008-11-01

    Piezoelectric ceramic Lead Zirconate Titanate (PZT) transducers, working on the principle of electromechanical impedance (EMI), are increasingly applied for structural health monitoring (SHM) in aerospace, civil and mechanical engineering. The PZT transducers are usually surface bonded to or embedded in a structure and subjected to actuation so as to interrogate the structure at the desired frequency range. The interrogation results in the electromechanical admittance (inverse of EMI) signatures which can be used to estimate the structural health or integrity according to the changes of the signatures. In the existing EMI method, the monitored structure is only excited by the PZT transducers for the interrogating of EMI signature, while the vibration of the structure caused by the external excitations other than the PZT actuation is not considered. However, many structures work under vibrations in practice. To monitor such structures, issues related to the effects of vibration on the EMI signature need to be addressed because these effects may lead to misinterpretation of the structural health. This paper develops an EMI model for beam structures, which takes into account the effect of beam vibration caused by the external excitations. An experimental study is carried out to verify the theoretical model. A lab size specimen with different external excitations is tested and the effect of vibration on EMI signature is discussed.

  13. Effect of External Vibration on PZT Impedance Signature

    Directory of Open Access Journals (Sweden)

    Yaowen Yang

    2008-11-01

    Full Text Available Piezoelectric ceramic Lead Zirconate Titanate (PZT transducers, working on the principle of electromechanical impedance (EMI, are increasingly applied for structural health monitoring (SHM in aerospace, civil and mechanical engineering. The PZT transducers are usually surface bonded to or embedded in a structure and subjected to actuation so as to interrogate the structure at the desired frequency range. The interrogation results in the electromechanical admittance (inverse of EMI signatures which can be used to estimate the structural health or integrity according to the changes of the signatures. In the existing EMI method, the monitored structure is only excited by the PZT transducers for the interrogating of EMI signature, while the vibration of the structure caused by the external excitations other than the PZT actuation is not considered. However, many structures work under vibrations in practice. To monitor such structures, issues related to the effects of vibration on the EMI signature need to be addressed because these effects may lead to misinterpretation of the structural health. This paper develops an EMI model for beam structures, which takes into account the effect of beam vibration caused by the external excitations. An experimental study is carried out to verify the theoretical model. A lab size specimen with different external excitations is tested and the effect of vibration on EMI signature is discussed.

  14. Performance of PZT based MEMS devices with integrated ZnO electronics

    Science.gov (United States)

    Wallace, Margeaux

    This thesis describes routes to enable increased understanding and performance of lead zirconate titanate-based microelectromechanical systems (MEMS). Emphasis was placed on monolithic integration with interposer electronics, and in understanding the role of mechanical boundary conditions on the ferroelectric/ferroelastic response. Co-processing of ZnO thin film transistors (TFTs) with Pb(Zr0.52 Ti0.48)0.98Nb0.02O3 (PZT)-based piezoelectrics was investigated to assess whether interposer electronics on PZT can serve as a control scheme for large area arrays of sensors or actuators. ZnO TFT processing produced no measured changes in remanent polarization, dielectric constant, loss tangent, or aging rates. The TFT performance also did not degrade when fabricated on top of the PZT, the mobility (> 24 cm/Vs) remaining comparable to TFTs deposited on glass. To show ZnO array integration, a 5x5 array of PZT capacitors on glass was fabricated as a prototype for an adjustable X-ray mirror, where the ZnO TFT were used for row-column addressing of the actuators. 1.5 mum thick sputter deposited PZT on glass patterned with large area (cm2) electrodes had a dielectric constant of >1200, tandelta ˜ 2% and an average remanent polarization >23 muC/cm 2. Photoreactive benzocyclobutene (BCB) electrically isolated the ZnO TFTs from the top electrodes of the piezoelectric. Flex cables were bonded to the wafer using anisotropic conductive film (ACF) to connect the gates (row control) and the drains (column control) in the TFT array to a control box. It was found that when actuating the PZT cells through the TFT array, the glass mirror experienced approximately 1.5 mum of deflection for a 10 V application. Studies on ferroelectric/ferroelastic domain reorientation were also performed on 1.9 mum thick tetragonal {001} oriented PbZr0.3Ti 0.7O3 films doped with 1% Mn. Different mechanical boundary constraints were investigated and domain reorientation was quantified through the intensity

  15. Extrinsic coefficient charcterisation of PZT ceramics near the morphotropic phase boundary

    Directory of Open Access Journals (Sweden)

    Albareda, A.

    2006-06-01

    Full Text Available PZT ceramics with high piezoelectric coefficients have high extrinsic contributions. This extrinsic behaviour, which is related to the domain wall movement, produces high non-linear effects that are sometimes inconvenient, for example when it increases the losses in power devices. The relation between extrinsic behaviour and non-linearities could be used to provide a good extrinsic characterization of materials in order to optimise the piezoelectric devices. In all cases the physical explanation of the behaviour is sought. The aim of this work is to study the dependence of the linear and non-linear dielectric, piezoelectric and mechanical coefficients on the Ti fraction in PZT ceramic compositions near the morphotropic phase boundary (MPB. The dependence of these coefficients on the defect concentration is also analysed. Hard ceramics belonging to Ferroperm Piezoceramics, with two different acceptor dopant levels, high and low, have been measured.

    Las cerámicas PZT con coeficientes piezoeléctricos elevados poseen contribuciones extrínsecas grandes. Este comportamiento extrínseco, relacionado con el movimiento de las paredes de los dominios, comporta efectos no lineales grandes que no siempre son deseables, por ejemplo, al incrementar las pérdidas de los dispositivos piezoeléctricos. Esta correspondencia entre efectos extrínsecos y no linealidades puede ser utilizada para caracterizar las cerámicas con el fin de optimizar sus propiedades piezoeléctricas. En todos los casos se busca una interpretación física de los resultados obtenidos. El objetivo de este trabajo es el estudio de la dependencia de los coeficientes lineales y no lineales dieléctricos, piezoeléctricos y elásticos con la fracción de Ti en cerámicas PZT con composiciones de Zr-Ti cerca de la transición de fase morfotrópica (MPB. También se analiza la dependencia de estos coeficientes con la concentración de impurezas, utilizando para ello cerámicas de

  16. Screen printed thick film based pMUT arrays

    DEFF Research Database (Denmark)

    Hedegaard, Tobias; Pedersen, T; Thomsen, Erik Vilain;

    2008-01-01

    This article reports on the fabrication and characterization of lambda-pitched piezoelectric micromachined ultrasound transducer (pMUT) arrays fabricated using a unique process combining conventional silicon technology and low cost screen printing of thick film PZT. The pMUTs are designed as 8...

  17. MEMS Accelerometer with Screen Printed Piezoelectric Thick Film

    DEFF Research Database (Denmark)

    Hindrichsen, Christian Carstensen; Lau-Moeller, R.; Bove, T.

    2006-01-01

    A bulk-micromachined piezoelectric MEMS accelerometer with screen printed piezoelectric Pb(ZrxTil )O3(PZT) thick film (TF) as the sensing material has been fabricated and characterized. The accelerometer has a four beam structure with a central seismic mass (3600x3600x500 pm3) and a total chip size...

  18. Towards a digital sound reconstruction MEMS device: Characterization of a single PZT based piezoelectric actuator

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2015-04-01

    In this paper we report the fabrication and characterization of a single piezoelectric actuator for digital sound reconstruction. This work is the first step towards the implementation of a true digital micro-loudspeaker by means of an array of acoustic actuators. These actuators consist of a flexible membrane fabricated using polyimide, which is actuated using a Lead-Zirconate-Titanate (PZT) piezoelectric ceramic layer working in the d31 actuation mode. The dimensions of the membrane are of 1mm diameter and 4μm in thickness, which is capable of being symmetrically actuated in both upward and downward directions, due to the back etch step releasing the membrane. Our electrical characterization shows an improvement in the polarization of the piezoelectric material after its final etch patterning step, and our mechanical characterization shows the natural modes of resonance of the stacked membrane. © 2015 IEEE.

  19. Deposition of highly (111)-oriented PZT thin films by using metal organic chemical deposition

    CERN Document Server

    Bu, K H; Choi, D K; Seong, W K; Kim, J D

    1999-01-01

    Lead zirconate titanate (PZT) thin films have been grown on Pt/Ta/SiNx/Si substrates by using metal organic chemical vapor deposition with Pb(C sub 2 H sub 5) sub 4 , Zr(O-t-C sub 4 H sub 9) sub 4 , and Ti(O-i-C sub 3 H sub 7) sub 4 as source materials and O sub 2 as an oxidizing gas. The Zr fraction in the thin films was controlled by varying the flow rate of the Zr source material. The crystal structure and the electrical properties were investigated as functions of the composition. X-ray diffraction analysis showed that at a certain range of Zr fraction, highly (111)-oriented PZT thin films with no pyrochlore phases were deposited. On the other hand, at low Zr fractions, there were peaks from Pb-oxide phases. At high Zr fractions, peaks from pyrochlore phase were seen. The films also showed good electrical properties, such as a high dielectric constant of more than 1200 and a low coercive voltage of 1.35 V.

  20. Dielectric Properties and Lattice Distortion in Rhombohedral Phase Region and Phase Coexistence Region of PZT Ceramics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Duan-Ming; ZHONG Zhi-Cheng; HAN Xiang-Yun; YAN Wen-Sheng; SUN Hong-Zhang; YANG Feng-Xia; ZHENG Ke-Yu; WEI Nian; LI Zhi-Hua

    2005-01-01

    In this paper, the relation between the dielectric properties and the lattice distortion in the phase coexistence region is discussed using a phase statistical distribution model, and in the rhombohedral phase region the two connection equations on the dielectric properties and the lattice distortion are established. Particularly, the relation between the dielectric properties and the lattice distortion is investigated in the phase coexistence region of PZT ceramics, and the fitting value of the volume fraction of the tetragonal phase VT to composition x in the equation is determined. Further,the fitting results are well consistent with the related experimental data. It involves more profound physical process than relation between the dielectric properties and composition x.

  1. Electrical properties of (0 0 1)-textured Pb(Zr,Ti)O 3 thin films with different BaPbO 3 thicknesses

    Science.gov (United States)

    Liang, Chun-Sheng; Wu, Jenn-Ming

    2006-05-01

    The microstructure and electrical properties of highly (0 0 1)-textured lead zirconate titanate (PZT) thin films deposited on BaPbO 3 (BPO) at 475 °C by RF-magnetron sputtering were studied. Twenty-three, 65, and 136 nm-thick BPOs were adopted in this study. The dielectric constant is approximately 433 for Pt/PZT/BPO (23 nm), 443 for Pt/PZT/BPO (65 nm), and 466 for Pt/PZT/BPO (136 nm). The remanant polarization values in these three capacitors are 13.5, 14.9, and 10.9 μC/cm 2, and the coercive field values are 76.6, 71.2, and 54.5 kV/cm, respectively. The fatigue endurance of PZT films decreases with the thickness of BPO. The thickness of BPO layer not only influences the crystallinity of PZT films, but also the a-domain populations in PZT films. The variation of resultant electrical properties is attributed partly to the improvement of crystallinity, and partly to the population of a-domain. The effect of the former is remarkable when the BPO is thin while the latter is dominant when the BPO is thick.

  2. Micromachined bulk PZT tissue contrast sensor for fine needle aspiration biopsy.

    Science.gov (United States)

    Li, Tao; Gianchandani, Roma Y; Gianchandani, Yogesh B

    2007-02-01

    This paper describes a micromachined piezoelectric sensor, integrated into a cavity at the tip of a biopsy needle, and preliminary experiments to determine if such a device can be used for real-time tissue differentiation, which is needed for needle positioning guidance during fine needle aspiration (FNA) biopsy. The sensor is fabricated from bulk lead zirconate titanate (PZT), using a customized process in which micro electro-discharge machining is used to form a steel tool that is subsequently used for batch-mode ultrasonic micromachining of bulk PZT ceramic. The resulting sensor is 50 microm thick and 200 microm in diameter. It is placed in the biopsy needle cavity, against a steel diaphragm which is 300 microm diameter and has an average thickness of 23 microm. Devices were tested in materials that mimic the ultrasound characteristics of human tissue, used in the training of physicians, and with porcine fat and muscle tissue. In both schemes, the magnitude and frequency of an electrical impedance resonance peak showed tissue-specific characteristics as the needle was inserted. For example, in the porcine tissue, the impedance peak frequency changed approximately 13 MHz from the initial 163 MHz, and the magnitude changed approximately 1600 Omega from the initial 2100 Omega, as the needle moved from fat to muscle. Samples including oils and saline solution were tested for calibration, and an empirical tissue contrast model shows an approximately proportional relationship between measured frequency shift and sample acoustic impedance. These results suggest that the device can complement existing methods for guidance during biopsies.

  3. Polymer - Ceramic Composites.

    Science.gov (United States)

    1988-04-01

    characteristic properties of our composite films are then compared with those of Piezel, a commercially available composite, manufactured by the Daikin Industry...S obtained on PIEZEL (composite of PZT and PVDF copolymer, supplied by Daikin Industries Limited of Japan) are also presented. 1% % .... . ,,, ,,,,~m

  4. Effect of different thickness h-BN coatings on interface shear strength of quartz fiber reinforced Si-O-C-N composite

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shubin [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Zheng, Yu, E-mail: shubinwang@buaa.edu.cn [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); International Centre for Bamboo and Rattan, Beijing 100102 (China)

    2014-02-15

    Hexagonal boron nitride (h-BN) coatings with different thickness were prepared on quartz fibers to improve mechanical properties of quartz fiber reinforced Si-O-C-N composite. Scanning electron microscopy (SEM), push-out test and single edge notched beam (SENB) in three point bending test were employed to study morphology, interface shear strength and fracture toughness of the composite. The results showed that h-BN coatings changed the crack growth direction and weaken the interface shear strength efficiently. When the h-BN coating was 308.2 nm, the interface shear strength was about 5.2 MPa, which was about one-quarter of that of the sample without h-BN coatings. After the heating process for obtaining composite, the h-BN nanometer-sized grains would grow up to micron-sized hexagonal grains. Different thickness h-BN coatings had different structure. When the coatings were relatively thin, the hexagonal grains were single layer structure, and when the coatings were thicker, the hexagonal grains were multiple layer structure. This multiple layer interface phase would consume more power of cracks, thus interface shear strength of the composite decreased steadily with the increasing of h-BN coatings thickness. When the coating thickness was 238.8 nm, K{sub IC} reaches the peak value 3.8 MPa m{sup 1/2}, which was more than two times of that of composites without h-BN coatings.

  5. Ultrasound backscatter microscope using PZT, fine-grain PZT, and single-crystal perovskite transducers

    Science.gov (United States)

    Olbrish, Kenneth D.; Zipparo, Michael J.; Lopath, Patrick D.; Yu, Clarence; Shrout, Thomas R.; Shung, K. Kirk

    1997-04-01

    Higher frequency ultrasound is rapidly becoming an important tool for dermatologic and ophthalmologic imaging. This brings about a need for improvement in single element transducers operating in the frequency range between 40 MHz and 100 MHz. Several piezoelectric materials may yield improved performance over common lead zirconate titanate (PZT) transducers. This study investigated several different materials incorporated into single element transducers. A static ultrasonic backscatter microscope (UBM) was constructed in the laboratory. This system allowed for a comparative testing of the imaging performance of various transducers. B-mode scans made by individual transducers show differences in image resolution. Clinically, these differences may be important to allow finer detail to be observed in a structure. Not only does this work show differences between transducers constructed from various materials, but it does so in an application-based environment. Previously, only a limited number of materials were used in such a system. This study showed results from several materials that had not been demonstrated before.

  6. The effect of carbon coating thickness on the capacity of LiFePO{sub 4}/C composite cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yung-Da; Fey, George Ting-Kuo [Department of Chemical and Materials Engineering, National Central University, Chung-Li 32054 (China); Kao, Hsien-Ming [Department of Chemistry, National Central University, Chung-Li 32054 (China)

    2009-04-01

    Two types of carbon source and precursor mixing pellets were employed simultaneously to prepare the LiFePO{sub 4}/C composite materials: Type I using the LiFePO{sub 4} precursor with 20 wt.% polystyrene (PS) as a primary carbon source, and Type II using the LiFePO{sub 4} precursor with 50 wt.% malonic acid as a secondary carbon vapor source. During final sintering, a Type I pellet was placed down-stream and Type II precursor pellet(s) was(were) placed upstream next to a Type I precursor pellet in a quartz-tube furnace. The carbon-coated product of the sintered Type I precursor pellet was obtained by using both PS and malonic acid as carbon sources. When two Type II pellets were used as a carbon vapor source (defined as Product-2), a more uniform film between 4 and 8 nm was formed, as shown in the TEM images. In the absence of a secondary carbon source (defined as Product-0), the discharge capacity of Product-0 was 137 mAh g{sup -1} with 100 cycles at a 0.2C-rate, but Product-2 demonstrated a high capacity of 151 mAh g{sup -1} with 400 cycles. Our results indicate that electrochemical properties of LiFePO{sub 4} are correlated to the amount of carbon and its coating thickness and uniformity. (author)

  7. Effects of ocean acidification and diet on thickness and carbonate elemental composition of the test of juvenile sea urchins.

    Science.gov (United States)

    Asnaghi, Valentina; Mangialajo, Luisa; Gattuso, Jean-Pierre; Francour, Patrice; Privitera, Davide; Chiantore, Mariachiara

    2014-02-01

    Continuous anthropogenic CO2 emissions to the atmosphere and uptake by the oceans will cause a reduction of seawater pH and saturation state (Ω) of CaCO3 minerals from which marine calcifiers build their shells and skeletons. Sea urchins use the most soluble form of calcium carbonate, high-magnesium calcite, to build their skeleton, spines and grazing apparatus. In order to highlight the effects of increased pCO2 on the test thickness and carbonate elemental composition of juvenile sea urchins and potential differences in their responses linked to the diet, we performed a laboratory experiment on juvenile Paracentrotus lividus, grazing on calcifying (Corallina elongata) and non-calcifying (Cystoseira amentacea, Dictyota dichotoma) macroalgae, under different pH (corresponding to pCO2 values of 390, 550, 750 and 1000 μatm). Results highlighted the importance of the diet in determining sea urchin size irrespectively of the pCO2 level, and the relevance of macroalgal diet in modulating urchin Mg/Ca ratio. The present study provides relevant clues both in terms of the mechanism of mineral incorporation and in terms of bottom-up processes (algal diet) affecting top-down ones (fish predation) in rocky subtidal communities. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Characterization of PZT Capacitor Structures with Various Electrode Materials Processed In-Situ Using AN Automated, Rotating Elemental Target, Ion Beam Deposition System

    Science.gov (United States)

    Gifford, Kenneth Douglas

    Ferroelectric thin film capacitor structures containing lead zirconate titanate (PZT) as the dielectric, with the chemical formula Pb(rm Zr_{x }Ti_{1-x})O_3, were synthesized in-situ with an automated ion beam sputter deposition system. Platinum (Pt), conductive ruthenium oxide (RuO_2), and two types of Pt-RuO_2 hybrid electrodes were used as the electrode materials. The capacitor structures are characterized in terms of microstructure and electrical characteristics. Reduction or elimination of non-ferroelectric phases, that nucleate during PZT processing on Pt/TiO _2/MgO and RuO_2/MgO substrates, is achieved by reducing the thickness of the individually deposited layers and by interposing a buffer layer (~100-200A) of PbTiO _3 (PT) between the bottom electrode and the PZT film. Capacitor structures containing a Pt electrode exhibit poor fatigue resistance, irregardless of the PZT microstructure or the use of a PT buffer layer. From these results, and results from similar capacitors synthesized with sol-gel and laser ablation, PZT-based capacitor structures containing Pt electrodes are considered to be unsuitable for use in memory devices. Using a PT buffer layer, in capacitor structures containing RuO_2 top and bottom electrodes and polycrystalline, highly (101) oriented PZT, reduces or eliminates the nucleation of zirconium-titanium oxide, non-ferroelectric species at the bottom electrode interface during processing. This results in good fatigue resistance up to ~2times10^ {10} switching cycles. DC leakage current density vs. time measurements follow the Curie-von Schweidler law, J(t) ~ t^ {rm -n}. Identification of the high electric field current conduction mechanism is inconclusive. The good fatigue resistance, low dc leakage current, and excellent retention, qualifies the use of these capacitor structures in non-volatile random access (NVRAM) and dynamic random access (DRAM) memory devices. Excellent fatigue resistance (10% loss in remanent polarization up to

  9. Piezoelectric Energy Harvesting Using PZT Bimorphs and Multilayered Stacks

    Science.gov (United States)

    Panda, Prasanta Kumar; Sahoo, Benudhar; Chandraiah, M.; Raghavan, Sreekumari; Manoj, Bindu; Ramakrishna, J.; Kiran, P.

    2015-11-01

    Piezoelectric materials have a unique ability to interchange electrical and mechanical energy. This property allows the absorption of mechanical energy such as ambient vibration and its transformation into electrical energy. The electrical energy generated can be used to power low-power electronic devices. In the present study, energy harvesting by lead zirconate titanate (PZT) multilayer (ML) stacks and bimorphs is presented. The devices were fabricated by a tape casting technique and were poled at 2 kV/mm for 30 min immersed in a silicone oil bath maintained at 60°C. The energy harvesting characteristics of the fabricated devices were measured in a suitably assembled test setup. The output voltage obtained from the PZT bimorphs and ML stacks was 450 mV and 125 mV, respectively. The higher output voltage from the bimorph is due to its low capacitance.

  10. Tape Casting of Honeywell PZT Type III Powder.

    Science.gov (United States)

    1984-02-01

    STANDARDS 193 A . . . • . .I-" ’ .7. ’. .. ’. .-7 . • " U) 1 IV. Tape Casting of Honeywell PZT Type III Poder II~ II * I S Gordon 0. Dayton Beth A. Jones...Street Port Hueneme, CA 93043 Arlington, VA 22217 3 ATTN: Materials Division Attn: Code 431 Naval Research Laboratory Naval Electronics Laboratory...Washington, DC 20375 San Diego, CA 92152 ATTN: Codes 6000 1 ATTN: Electron Materials 6300 1 Sciences Division 2627 1 Naval Air Development Center Naval

  11. Characterisation of static actuation behaviour of encapsulated PZT

    Science.gov (United States)

    Doran, Conrad J.; Butler, Raymond J.

    1994-09-01

    Within the field of 'smart' structures considerable interest has been shown in the use of piezoelectric materials both as sensors and actuators. One of the best characterized of these materials is the family of Lead Zirconate Titanate (PZT) based ceramics. The use of PZT in intelligent systems has been fairly widespread, the high modulus of the material give high authority actuation, coupled with a wide operational bandwidth and relative ease of control by the application of an applied voltage. The linearity of the actuation response over a limited range has made PZT a popular choice for high precision, relatively low displacement applications. A number of attempts have been made to utilize such actuators for aerospace, using both surface mounting [1] and embedding techniques [2,3]. The effects of actuators on aeroelastic performance has also been investigated for aerospace applications [4,5]. The current practical solution to this problem appears to be the use of spatially distributed actuators [6]. One of the practical limitations of this problem are the large number of actuators required to produce the required degree of static control. In order to ensure accurate shape control, measurements must be taken to ensure there are no significant difference in the actuator element properties due to factors such as batch processing variation. In the past this has proved difficult due to the extremely brittle nature of the actuator material. More specifically the requirement for thinner elements for use in embedded applications has increased this problem. A method by which the static performance of electroceramic actuators could be quickly established would therefore be desirable. This paper presents the results of recent work to develop a test method to define the static electromechanical properties of encapsulated actuator materials in order to assess their suitability as static actuators for aerospace applications. Preliminary results using a standard PZT material are

  12. Performance of magnetoelectric PZT/Ni multiferroic system for energy harvesting application

    Science.gov (United States)

    Gupta, Reema; Tomar, Monika; Kumar, Ashok; Gupta, Vinay

    2017-03-01

    Magnetoelectric (ME) coefficient of Lead Zirconium Titanate (PZT) thin films has been probed for possible energy harvesting applications. Single phase PZT thin films have been deposited on nickel substrate (PZT/Ni) using pulsed laser deposition (PLD) technique. The effect of PLD process parameters on the ME coupling coefficient in the prepared systems has been investigated. The as grown PZT films on Ni substrate were found to be polycrystalline with improved ferroelectric and ferromagnetic properties. The electrical switching behavior of the PZT thin films were verified using capacitance voltage measurements, where well defined butterfly loops were obtained. The ME coupling coefficient was estimated to be in the range of 94.5 V cm‑1 Oe‑1–130.5 V cm‑1 Oe‑1 for PZT/Ni system, which is large enough for harnessing electromagnetic energy for subsequent applications.

  13. Modeling the thermal behavior of PZT patches during the manufacturing process of smart thermoplastic structures

    Science.gov (United States)

    Elsoufi, L.; Khalil, K.; Lachat, R.; Charon, W.

    2007-08-01

    This paper concerns the manufacturing processes of thermoplastic structures including piezoceramic patches (PZT). The objective of the study reported here was to find a trade-off between the manufacturing conditions and the thermal endurance of the PZT patches. We studied the influence of high temperatures on the PZT efficiency during manufacturing. Two processes were considered: injection molding and thermoforming. The studied object consists of a polypropylene plate containing a PZT patch integrated at different positions. On the one hand, we simulated with ANSYS the thermal transient effects to study the PZT cooling according to the time of its exposure to heat for different fabrication cases and with different manufacturing processes. On the other hand, the loss in PZT generated voltage according to the temperature increment was measured by thermo-mechanical experiences using a dynamical-mechanical analysis machine (DMA) connected to an acquisition chain.

  14. Multilayer thin films with compositional PbZr0.52Ti0.48O3/Bi1.5Zn1.0Nb1.5O7 layers for tunable applications.

    Science.gov (United States)

    Yu, Shihui; Li, Lingxia; Zhang, Weifeng; Sun, Zheng; Dong, Helei

    2015-05-11

    The dielectric properties and tunability of multilayer thin films with compositional PbZr0.52Ti0.48O3/Bi1.5Zn1.0Nb1.5O7 (PZT/BZN) layers (PPBLs) fabricated by pulsed laser deposition on Pt/TiO2/SiO2/Si substrate have been investigated. Dielectric measurements indicate that the PZT/BZN bilayer thin films exhibit medium dielectric constant of about 490, low loss tangent of 0.017, and superior tunable dielectric properties (tunability=49.7% at 500 kV/cm) at a PZT/BZN thickness ratio of 3, while the largest figure of merit is obtained as 51.8. The thickness effect is discussed with a series connection model of bilayer capacitors, and the calculated dielectric constant and loss tangent are obtained. Furthermore, five kinds of thin-film samples comprising single bilayers, two, three, four and five PPBLs were also elaborated with the final same thickness. The four PPBLs show the largest dielectric constant of ~538 and tunability of 53.3% at a maximum applied bias field of 500 kV/cm and the lowest loss tangent of ~0.015, while the largest figure of merit is 65.6. The results indicate that four PPBLs are excellent candidates for applications of tunable devices.

  15. Piezoelectric characteristics of PZT thin films on polymer substrate

    Science.gov (United States)

    Kang, Min-Gyu; Do, Younh-Ho; Oh, Seung-Min; Rahayu, Rheza; Kim, Yiyein; Kang, Chong-Yun; Nahm, Sahn; Yoon, Seok-Jin

    2012-02-01

    The goal of piezoelectric energy harvesting is to improve the power efficiency of devices. One of the approaches for the improvement of power efficiency is to apply the large strain on the piezoelectric materials and then many scientists approached using thin films or nano-structured piezoelectric materials to obtain flexibility. However, the conventional thin film processes available for the fabrication of piezoelectric materials as PbZr0.52Ti0.48O3 (PZT) are not compatible with flexible electronics because they require high processing temperatures (>700^oC) to obtain piezoelectricity. Excimer laser annealing (ELA) is attractive heat process for the low-temperature crystallization, because of its material selectivity and short heating time. In this study, the amorphous PZT thin films were deposited on polymer substrate by rf-sputtering. To crystallize the amorphous films, the ELA was carried out with various conditions as function of the applied laser energy density, the number of pulse, and the repetition rate. To evaluate the piezoelectric characteristics, piezoelectric force microscopy (PFM) and electrometer are used. As a result, we obtained the crystallized PZT thin film on flexible substrate and obtained flexible piezoelectric energy harvester.

  16. Broadband Electromagnetic Emission from PZT Ferroelectric Ceramics after Shock Loading

    Directory of Open Access Journals (Sweden)

    Fiodoras ANISIMOVAS

    2013-12-01

    Full Text Available It was experimentally registered pulsed electromagnetic (EM radiation in frequency range higher than television one using wideband horns with coaxial and waveguide outputs. The EM radiation was received during shock loading of lead zirconate titanate (PZT ceramics cylinders in conventional piezoelectric ignition mechanisms. Digital oscilloscope allows registering whole series of EM pulses and each pulse from the series transmitted from horn antenna of (1 – 18 GHz operating band frequencies. There is (1 – 4 ms delay between the shock and the first pulse of the series. Duration of the series is about (3 – 4 ms. The PZT cylinders were cleaved along their axes and the surfaces formed in the process were investigated by scanning electron microscope. It was concluded that from electrical point of view PZT ceramics contain interacting subsystems. It was found that EM radiation spectrum of pulse detected by waveguide detector heads has harmonics reaching 80 GHz. Presence of harmonics higher than 20 GHz indicates on radiation due to deceleration of electrons emitted during the switching. The EM pulses in the series appear randomly and have different amplitudes which partly confirmed thesis on independent switching dynamics of small volumes governed by a local electric field.DOI: http://dx.doi.org/10.5755/j01.ms.19.4.3137

  17. Strong nonlinear harmonic generation in a PZT/Aluminum resonator

    Energy Technology Data Exchange (ETDEWEB)

    Parenthoine, D; Haumesser, L; Meulen, F Vander; Tran-Huu-Hue, L-P, E-mail: parenthoine@univ-tours.f [University Francois Rabelais of Tours, U 930 Imagerie et Cerveau, CNRS 2448, ENIVL, rue de la Chocolaterie, BP 3410, 41034 Blois (France)

    2009-11-01

    In this work, the extentional vibration mode of a coupled PZT/ Aluminum rod resonator is studied experimentally. Geometrical characteristics of the PZT are its 27 mm length and its 4x4 mm{sup 2} cross section area. The excitation voltage consists in sinusoidal bursts in the frequency range (20-80 kHz). Velocity measurements are performed at both ends of this system, using a laser probe. Strong harmonic distortions in the mechanical response (up to -20 dB with respect to the primary wave amplitude) have been observed. The corresponding input levels are far lower than those which are necessary to observe quadratic second harmonic generation in a free PZT resonator. The strong nonlinear effect can be explained as a super-harmonic resonance of the system due to a specific ratio between the eigen frequencies of the two parts of the resonator. Evolution of fundamental and harmonic responses are observed as a function of input levels, highlighting hysteretic behavior.

  18. Broadband Electromagnetic Emission from PZT Ferroelectric Ceramics after Shock Loading

    Directory of Open Access Journals (Sweden)

    Fiodoras ANISIMOVAS

    2013-12-01

    Full Text Available It was experimentally registered pulsed electromagnetic (EM radiation in frequency range higher than television one using wideband horns with coaxial and waveguide outputs. The EM radiation was received during shock loading of lead zirconate titanate (PZT ceramics cylinders in conventional piezoelectric ignition mechanisms. Digital oscilloscope allows registering whole series of EM pulses and each pulse from the series transmitted from horn antenna of (1 – 18 GHz operating band frequencies. There is (1 – 4 ms delay between the shock and the first pulse of the series. Duration of the series is about (3 – 4 ms. The PZT cylinders were cleaved along their axes and the surfaces formed in the process were investigated by scanning electron microscope. It was concluded that from electrical point of view PZT ceramics contain interacting subsystems. It was found that EM radiation spectrum of pulse detected by waveguide detector heads has harmonics reaching 80 GHz. Presence of harmonics higher than 20 GHz indicates on radiation due to deceleration of electrons emitted during the switching. The EM pulses in the series appear randomly and have different amplitudes which partly confirmed thesis on independent switching dynamics of small volumes governed by a local electric field.DOI: http://dx.doi.org/10.5755/j01.ms.19.4.3137

  19. Hydrothermal synthesis and characterization of fluorine & manganese co-doped PZT based cuboidal shaped powder

    Science.gov (United States)

    Nawaz, H.; Shuaib, M.; Saleem, M.; Rauf, A.; Aleem, A.

    2016-08-01

    Cuboidal shaped PZT powder particles based composition Pb0.89(Ba, Sr)0.11(Zr0.52Ti0.48)O3 co- doped with 1 mol% manganese and 2 mol% fluorine was prepared through hydrothermal route. 200-250nm size cuboidal particles were observed under FE-SEM. XRD technique revealed that the perovskite type ceramic structure has a dominant rhombohedral phase. The resultant powder particles were then spray dried, uniaxially pressed and sintered at different temperatures to achieve maximum theoretical density. 98% density was obtained in the pellets at a sintering temperature of 1190°C with an average grain size of 1-3um. The electrical properties of sintered samples were also measured before and after poling to evaluate the effect of dopants on piezoelectric properties.

  20. Highly-efficient, flexible piezoelectric PZT thin film nanogenerator on plastic substrates.

    Science.gov (United States)

    Park, Kwi-Il; Son, Jung Hwan; Hwang, Geon-Tae; Jeong, Chang Kyu; Ryu, Jungho; Koo, Min; Choi, Insung; Lee, Seung Hyun; Byun, Myunghwan; Wang, Zhong Lin; Lee, Keon Jae

    2014-04-23

    A highly-efficient, flexible piezoelectric PZT thin film nanogenerator is demonstrated using a laser lift-off (LLO) process. The PZT thin film nanogenerator harvests the highest output performance of ∼200 V and ∼150 μA·cm(-2) from regular bending motions. Furthermore, power sources generated from a PZT thin film nanogenerator, driven by slight human finger bending motions, successfully operate over 100 LEDs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. An Unconventional Inchworm Actuator Based on PZT/ERFs Control Technology

    OpenAIRE

    Guojun Liu; Yanyan Zhang; Jianfang Liu; Jianqiao Li; Chunxiu Tang; Tengfei Wang; Xuhao Yang

    2016-01-01

    An unconventional inchworm actuator for precision positioning based on piezoelectric (PZT) actuation and electrorheological fluids (ERFs) control technology is presented. The actuator consists of actuation unit (PZT stack pump), fluid control unit (ERFs valve), and execution unit (hydraulic actuator). In view of smaller deformation of PZT stack, a new structure is designed for actuation unit, which integrates the advantages of two modes (namely, diaphragm type and piston type) of the volume c...

  2. Compositional variation within thick (>10 m) flow units of Mauna Kea Volcano cored by the Hawaii Scientific Drilling Project

    Science.gov (United States)

    Huang, Shichun; Vollinger, Michael J.; Frey, Frederick A.; Rhodes, J. Michael; Zhang, Qun

    2016-07-01

    Geochemical analyses of stratigraphic sequences of lava flows are necessary to understand how a volcano works. Typically one sample from each lava flow is collected and studied with the assumption that this sample is representative of the flow composition. This assumption may not be valid. The thickness of flows ranges from 100 m. Geochemical heterogeneity in thin flows may be created by interaction with the surficial environment whereas magmatic processes occurring during emplacement may create geochemical heterogeneities in thick flows. The Hawaii Scientific Drilling Project (HSDP) cored ∼3.3 km of basalt erupted at Mauna Kea Volcano. In order to determine geochemical heterogeneities in a flow, multiple samples from four thick (9.3-98.4 m) HSDP flow units were analyzed for major and trace elements. We found that major element abundances in three submarine flow units are controlled by the varying proportion of olivine, the primary phenocryst phase in these samples. Post-magmatic alteration of a subaerial flow led to loss of SiO2, CaO, Na2O, K2O and P2O5, and as a consequence, contents of immobile elements, such as Fe2O3 and Al2O3, increase. The mobility of SiO2 is important because Mauma Kea shield lavas divide into two groups that differ in SiO2 content. Post-magmatic mobility of SiO2 adds complexity to determining if these groups reflect differences in source or process. The most mobile elements during post-magmatic subaerial and submarine alteration are K and Rb, and Ba, Sr and U were also mobile, but their abundances are not highly correlated with K and Rb. The Ba/Th ratio has been used to document an important role for a plagioclase-rich source component for basalt from the Galapagos, Iceland and Hawaii. Although Ba/Th is anomalously high in Hawaiian basalt, variation in Ba abundance within a single flow shows that it is not a reliable indicator of a deep source component. In contrast, ratios involving elements that are typically immobile, such as La/Nb, La

  3. Dielectric and pyroelectric properties of lead zirconate titanate/polyurethane composites

    Science.gov (United States)

    Lam, K. S.; Wong, Y. W.; Tai, L. S.; Poon, Y. M.; Shin, F. G.

    2004-10-01

    0-3 composite ranging between 0 and 3, of ferroelectric ceramic lead zirconate titanate (PZT) and thermoplastic elastomer polyurethane (PU) were fabricated. The pyroelectric and dielectric properties of the hot-pressed thin film samples of various PZT volume fractions were measured. The experimental dielectric permittivities and losses agreed reasonably well with the Bruggeman model. The room temperature pyroelectric coefficients of the composites were found to increase linearly with PZT volume fraction and substantially larger than expected. For example, for a composite with 30% PZT, its pyroelectric coefficient is about 90μC/m2K at room temperature, which is more than tenfold of a PZT/PVDF composite of the same ceramic volume fraction. We propose a model in which the electrical conductivity of the composite system is taken into consideration to explain the linear relationship and the extraordinarily large pyroelectric coefficients obtained.

  4. Study of CoFeB thickness and composition dependence in a modified CoFeB/MgO/CoFeB perpendicular magnetic tunnel junction

    Science.gov (United States)

    Zhu, M.; Chong, H.; Vu, Q. B.; Brooks, R.; Stamper, H.; Bennett, S.

    2016-02-01

    We studied the CoFeB thickness and composition dependence of tunneling magnetoresistance (TMR) and resistance-area product (RA) in a modified CoFeB/MgO/CoFeB perpendicular magnetic tunnel junction (MTJ), in which the bottom CoFeB is coupled to an in-plane exchange biased magnetic layer. This stack structure allows us to measure TMR and RA of the MTJs in sheet film format without patterning them, using current-in-plane-tunneling (CIPT) technique. The thickness ranges for both top and bottom CoFeB to exhibit perpendicular magnetic anisotropy are similar to what are seen in each single magnetic film stack. However, CIPT measurement revealed that there exists an optimal thickness for both top and bottom CoFeB to achieve the highest TMR value. Magnetic hysteresis loops also suggest the thickness-dependent coupling between the top and bottom CoFeB layers. We studied MTJs with two CoFeB compositions (Co40Fe40B20 and Co20Fe60B20) and found that Co20Fe60B20 MTJs give higher TMR and also wider perpendicular thickness range when used at the top layer.

  5. Effect of Pb content and solution concentration of Pb{sub x}TiO{sub 3} seed layer on (100)-texture and ferroelectric/dielectric behavior of PZT (52/48) thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Jian; Batra, Vaishali; Han, Hui; Kotru, Sushma, E-mail: skotru@eng.ua.edu [Department of Electrical and Computer Engineering, The University of Alabama, Tuscaloosa, Alabama 35487 (United States); Pandey, Raghvendar K. [Ingram School of Engineering, Texas State University, San Marcos, Texas 78666 (United States)

    2015-09-15

    The effect of Pb content and solution concentration of lead titanate (Pb{sub x}TiO{sub 3}) seed layer on the texture and electric properties of Pb{sub 1.1}(Zr{sub 0.52},Ti{sub 0.48})O{sub 3} (PZT) thin films was investigated. A variety of seed layers (y Pb{sub x}TiO{sub 3}) with varying solution concentration (y = 0.02, 0.05, 0.1, and 0.2 M) and Pb content (x = 1.0, 1.05, 1.1, and 1.2) was deposited on Pt/TiO{sub 2}/SiO{sub 2}/Si substrates using chemical-solution deposition method. PZT films were then deposited on these seed layers using the same process. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy investigations of the seed layers confirm change in crystal structure with variation in the solution properties. XRD studies of PZT films deposited on seed layers demonstrate that the seed layer helps in enhancing (100)-texture and suppressing (111)-texture. It was observed that PZT films prepared on seed layers with lower solution concentrations results in highly (100)-textured films, which further helps to improve the electric properties. The polarization and dielectric constant of the PZT films were seen to increase while the coercive field decreased with increase in (100)-texture. Irrespective of the seed layer solution concentration, higher Pb content in the seed layer deteriorates the PZT film properties. Ninety-five percent to ninety-six percent (100)-texture was obtained from thin PZT films deposited on seed layers of 0.02 M solution concentration with 1.05 and 1.10 Pb contents, which is higher than the values reported for thick PZT films. Optimization of both Pb content and solution concentration of the seed layer is a promising route to achieve highly (100)-textured PZT films with improved electric properties.

  6. CORRELATION OF SiOx LAYER THICKNESS AND PROPERTIES OF BOPP/SiOx COMPOSITE FILMS WITH SPIN COATING PROCESS PARAMETERS

    Institute of Scientific and Technical Information of China (English)

    Xiao-li Yao; Yu-hong Ma; Chang-wen Zhao; Wan-tai Yang

    2013-01-01

    The effects of the spin coating process parameters on the thickness of the SiOx layer of the BOPP/SiOx composite film were investigated.When the concentration of tetraethoxysilane (TEOS) increased from 12.5 vol% to 55% vol%,the SiOx thickness increased from about 80 nm to 470 nm.In the sol time range of 1.5 h to 5 h the SiOx layer thickness reached a maximum at about 4 h and the change of the thickness roughly matched the change of the silica colloidal sphere sizes in sol.When the spin-coating speed of the dispensing stage increased from 450 r/min to 500 r/min,the SiOx layer thickness drastically decreased from about 1.67 μm to 400 nm.While the spin-coating speed of the thinning and drying stage went up to 1200 r/min,the SiOx layer thickness was in the range of 330 nm to 390 nm.It was also found that the SiOx layer thickness was almost increased linearly from about 500 nm to 1.02 μm with the ratio of the commercial silica colloidal to the TEOS from 0.2 to 1.0.The water contact angles decreased to about 23.0° for the BOPP/Si-Sol composite film with 1.67 μm SiOx layer and about 4.0° for the BOPP/mixing Si-Sol composite film with 1.02 μm SiOx layer.Compared to BOPP,the light transparency of the BOPP/Si-Sol composite films decreased by about 5.5% with the SiOx layer from about 80 nm to 1.67 μm and by 7.0% for the BOPP/mixing Si-Sol composite film with the SiOx layer from about 350 nm to 1.02 μm respectively.

  7. THE EFFECTS OF EDGE BANDING THICKNESS OF ULUDAG FIR BONDED WITH SOME ADHESIVES ON WITHDRAWAL STRENGTHS OF BEECH DOWEL PINS IN COMPOSITE MATERIALS

    Directory of Open Access Journals (Sweden)

    Şeref Kurt

    2009-11-01

    Full Text Available Composite materials and wooden dowels are being used increasingly in the construction of furniture frames and inner decoration. Yet there is little information available concerning the withdrawal strength of various fasteners, and, in particular, dowels in composite materials edged solid wood edge bandings. The aim of this study was to determine the withdrawal strengths of 6, 8, 10 mm diameter dowels produced from beech with respect to edge of a medium-density fiberboard (MDF or particleboard (PB edged with 5, 10 and 15 mm thickness of solid wood edge banding of uludag fir, bonded with different adhesives. According to TS 4539 standard, the effects of edge banding thickness, dimension of dowels, type of composite materials and type of adhesives used for edge banding on the withdrawal strength were determined. The highest (6.37 N/mm² withdrawal strength was obtained in beech dowels with 8 mm diameter for MDF with 5 mm thickness of solid wood edge banding of uludag fir bonded with D-VTKA adhesive. According to results, if the hole wall and the surface of dowel are smooth then the adhesives give better mechanical adhesion with dowels and composite materials.

  8. Preparation of thick-film electrode-solid electrolyte composites on Li7La3Zr2O12 and their electrochemical properties

    Science.gov (United States)

    Kato, Takeshia; Iwasaki, Shinya; Ishii, Yosuke; Motoyama, Munekazu; West, William C.; Yamamoto, Yuta; Iriyama, Yasutoshi

    2016-01-01

    We prepared up to 20 μm-thick LiNi1/3Co1/3Mn1/3O2 (NMC)-Li+ conductive glass-ceramic solid electrolyte (LATP: σLi+ ˜ 10-3 S cm-2 at 298 K) composite cathode films on Li7La3Zr2O12 (LLZ) substrates by aerosol deposition (AD) and investigated their electrochemical properties as all-solid-state batteries. The resultant NMC/LATP interface in the composite film had a thin mutual diffusion layer (˜5 nm) and a film had a porosity of ca. 0.15% in volume. The composite films were well adhered to the LLZ substrates even though the films were prepared at room temperature. All-solid-state batteries, consisting of Li/LLZ/NMC-LATP composite film (20 μm), repeated charge-discharge reactions for 90 cycles at 100 °C at a 1/10 C rate (capacity retention: 99.97%/cycle). Rate capability of this battery was improved by modifying both the LATP and electron conductive source amount in the composite film, and a battery with 16 μm-thick composite electrode delivered 60 mAh g-1 at 1 mA cm-2.

  9. Enhanced Magnetoelectric Effect in Permendur/Pb(Zr0.52Ti0.48O3 Laminated Magnetostrictive/Piezoelectric Composite

    Directory of Open Access Journals (Sweden)

    Yanmin Jia

    2015-09-01

    Full Text Available In this work, after investigating three typical magneto-electric (ME composites, Permendur/Pb(Zr0.52Ti0.48O3(PZT, Metglas/PZT, and Tefenol-D/PZT, with the same dimensions and different saturation magnetostriction and magnetic permeability, the most excellent ME performance is observed in the Permendur/PZT laminates, which agrees well with the predicted results from the figure of merit. The low-frequency and resonance ME coefficients of Permendur/PZT composite are ~23.1 V/Oe.cm and ~309 V/Oe.cm at the optimal dc bias magnetic field of ~250 Oe, respectively. The strong ME effect of Permendur/PZT composite gives it potential in practical magnetic sensitive device applications.

  10. Changes in skinfold thickness and body composition among children and adolescents in Shandong, China from 1995 to 2010.

    Science.gov (United States)

    Zhang, Y-X; Wang, S-R

    2013-06-01

    There is strong evidence of a upward secular trend in skinfold thickness (SFT) and the prevalence of obesity has increased substantially over recent decades in developed countries. However, no studies on this trend have been reported in Shandong Province, China. The present study aimed to assess the decennial change in SFT and body composition among children and adolescents in Shandong Province during the past 15 years (1995-2010). Data were obtained from two national surveys on student's constitution and health carried out by the government in 1995 and 2010 in Shandong Province, China. A total of 14 780 (7198 in 1995 and 7582 in 2010) students aged 7-18 years participated in the present study. Weight and SFT of all subjects were measured. Percentage body fat (%FM) was estimated by SFT, and fat mass (FM) and fat-free mass (FFM) were calculated from: FM (kg) = %FM × weight (kg)/100; FFM (kg) = weight (kg)-FM(kg). The range of differences of weight, SFT, FM and FFM over the different age groups between the 1995 and 2010 samples were calculated. In the past 15 years, mean values of SFT have increased. The mean (range) increments of SFT were 6.28 (2.91-11.22) mm for boys and 3.29 (2.22-4.29) mm for girls, demonstrating a mean increase of 32% for boys and 14% for girls. The mean (range) increments of weight, FM and FFM were 7.26 (4.41-10.82) kg, 3.70 (1.47-6.58) kg and 3.56 (1.24-5.27) kg, at rates of 18%, 47% and 10% for boys, respectively, and 4.14 (2.78-5.64) kg, 1.68 (1.02-2.27) kg and 2.46 (1.52-3.49) kg, at rates of 11%, 20% and 8% for girls, respectively. The mean values of SFT, FM and FFM have increased over time. Rates of increase were greater for FM than FFM. © 2012 The Authors Journal of Human Nutrition and Dietetics © 2012 The British Dietetic Association Ltd.

  11. Tunable characteristics of bending resonance frequency in magnetoelectric laminated composites

    Institute of Scientific and Technical Information of China (English)

    Chen Lei; Li Ping; Wen Yu-Mei; Zhu Yong

    2013-01-01

    As the magnetoelectric (ME) effect in piezoelectric/magnetostrictive laminated composites is mediated by mechanical deformation,the ME effect is significantly enhanced in the vicinity of resonance frequency.The bending resonance frequency (fr) of bilayered Terfenol-D/PZT (MP) laminated composites is studied,and our analysis predicts that (i) the bending resonance frequency of an MP laminated composite can be tuned by an applied dc magnetic bias (Hdc) due to the △E effect; (ii) the bending resonance frequency of the MP laminated composite can be controlled by incorporating FeCuNbSiB layers with different thicknesses.The experimental results show that with Hdc increasing from 0Oe (1 Oe=79.5775 A/m)to 700 Oe,the bending resonance frequency can be shifted in a range of 32.68 kHz ≤ fr ≤ 33.96 kHz.In addition,with the thickness of the FeCuNbSiB layer increasing from 0 μm to 90 μm,the bending resonance frequency of the MP laminated composite gradually increases from 33.66 kHz to 39.18 kHz.This study offers a method of adjusting the strength of dc magnetic bias or the thicknesses of the FeCuNbSiB layer to tune the bending resonance frequency for ME composite,which plays a guiding role in the ME composite design for real applications.

  12. Hybrid Carbon-Glass Fiber/Toughened Epoxy Thick Composite Joints Subject to Drop-Weight and Ballistic Impacts

    Science.gov (United States)

    2007-12-01

    Composite Materials 1988; 22: 518-532. 111. Liaw BM, Pierides AM and Liu YX. Ultrasonic assessment of impact damage in aluminum /acrylic sandwich plates...Ninth International Conference on Composite Materials , ICCM/9, Vol. V: Composites Behaviour , Miravete A (Ed), Madrid, Spain, July 12-16, 1993: 311-320...line loading. J. of Composite Materials 1993; 27: 1443-64. 148. Mouritz AP, Gallagher J and Goodwin AA. Flexural strength and interlaminar shear

  13. Sensitivity of PZT Impedance Sensors for Damage Detection of Concrete Structures

    Directory of Open Access Journals (Sweden)

    Yong Lu

    2008-01-01

    Full Text Available Piezoelectric ceramic Lead Zirconate Titanate (PZT based electro-mechanicalimpedance (EMI technique for structural health monitoring (SHM has been successfullyapplied to various engineering systems. However, fundamental research work on thesensitivity of the PZT impedance sensors for damage detection is still in need. In thetraditional EMI method, the PZT electro-mechanical (EM admittance (inverse of theimpedance is used as damage indicator, which is difficult to specify the effect of damage onstructural properties. This paper uses the structural mechanical impedance (SMI extractedfrom the PZT EM admittance signature as the damage indicator. A comparison study on thesensitivity of the EM admittance and the structural mechanical impedance to the damages ina concrete structure is conducted. Results show that the SMI is more sensitive to the damagethan the EM admittance thus a better indicator for damage detection. Furthermore, this paperproposes a dynamic system consisting of a number of single-degree-of-freedom elementswith mass, spring and damper components to model the SMI. A genetic algorithm isemployed to search for the optimal value of the unknown parameters in the dynamic system.An experiment is carried out on a two-storey concrete frame subjected to base vibrations thatsimulate earthquake. A number of PZT sensors are regularly arrayed and bonded to the framestructure to acquire PZT EM admittance signatures. The relationship between the damageindex and the distance of the PZT sensor from the damage is studied. Consequently, thesensitivity of the PZT sensors is discussed and their sensing region in concrete is derived.

  14. Thin Film PZT Piezo MEMS for Micro-Robotic Angular Rate Sensing and Rotary Actuation

    Science.gov (United States)

    2012-07-31

    Luz Sanchez, Rob Proie, Vishnu Ganesan, Joe Conroy, and Ron Polcawich July 31, 2012 U.S. Army Research Laboratory THIN FILM PZT PIEZO MEMS FOR...Caltech Angular rate sensing on 1-30 mg platform • 2 orders smaller than packaged state of the art gyroscope. • Integrated biomimetic PZT actuator

  15. Influence of the Depth on the Shape and Thickness of Nacre Tablets of Pinctada margaritifera Pearl Oyster, and on Oxygen Isotopic Composition

    Directory of Open Access Journals (Sweden)

    Marthe Rousseau

    2012-03-01

    Full Text Available Nacre, or mother of pearl, is composed of aragonite tablets and is produced by some mollusks. Because of the highly organized internal structure, chemical complexity, mechanical properties and optical effects of nacre, its formation is among the best-studied examples of calcium carbonate biomineralization. The pearl oyster Pinctada margaritifera is harvested in French Polynesia for pearl farming. The quality of the pearl depends on the quality of the nacre on its surface and its iridescent colors are affected by the thickness of the layers. Here we report on an experimental study conducted to influence the shape and the thickness of nacre tablets by keeping pearl oysters at four different depths (7, 20, 30 and 39 m for one week. Scanning electron microscopy was used to measure the thickness of the nacre tablets and to analyze their final shape. The shape of the tablets changed from hexagonal to rhomboid at a depth of 39 m. The change in shape led to a change in size. The thickness of the tablets was reduced by between 16 and 30% on average. We also measured the oxygen isotopic composition using Secondary Ion Mass Spectrometry. In this study, we demonstrated that depth can modify the size, shape and thickness of nacre tablets, but not the d18O. This environmental modification is important for the biomineralization of the shell of the pearl oyster Pinctada margaritifera.

  16. Impedance-Based Cable Force Monitoring in Tendon-Anchorage Using Portable PZT-Interface Technique

    Directory of Open Access Journals (Sweden)

    Thanh-Canh Huynh

    2014-01-01

    Full Text Available In this paper, a portable PZT interface for tension force monitoring in the cable-anchorage subsystem is developed. Firstly, the theoretical background of the impedance-based method is presented. A few damage evaluation approaches are outlined to quantify the variation of impedance signatures. Secondly, a portable PZT interface is designed to monitor impedance signatures from the cable-anchorage subsystem. One degree-of-freedom analytical model of the PZT interface is established to explain how to represent the loss of cable force from the change in the electromechanical impedance of the PZT interface as well as reducing the sensitive frequency band by implementing the interface device. Finally, the applicability of the proposed PZT-interface technique is experimentally evaluated for cable force-loss monitoring in a lab-scaled test structure.

  17. A new three-dimensional electromechanical impedance model for an embedded dual-PZT transducer

    Science.gov (United States)

    Wang, Dansheng; Li, Zhi; Zhu, Hongping

    2016-07-01

    In the past twenty years, the electromechanical (EM) impedance technique has been investigated extensively in the mechanical, aviation and civil engineering fields. Many different EM impedance models have been proposed to characterize the interaction between the surface-bonded PZT transducer and the host structure. This paper formulates a new three-dimensional EM impedance model characterizing the interaction between an embedded circle dual-PZT transducer and the host structure based on the effective impedance concept. The proposed model is validated by experimental results from a group of smart cement cubes, in which three circle dual-PZT transducers are embedded respectively. In addition, a new EM impedance measuring method for the dual-PZT transducer is also introduced. In the measuring method, only a common signal generator and an oscilloscope are needed, by which the exciting and receiving voltage signals are obtained respectively. Combined with fast Fourier transform the EM impedance signatures of the dual-PZT transducers are obtained.

  18. Experimental Study on Abrasive Water Jet Machining of PZT Ceramic

    Science.gov (United States)

    Dhanawade, Ajit; Upadhyai, Ravi; Rouniyar, Arunkumar; Kumar, Shailendra

    2017-07-01

    This paper presents research work involved in abrasive water jet machining of PZT ceramic material. Process parameters namely stand-off distance, water pressure and traverse rate are considered in the present study. Response surface methodology approach is used to design the experiments. Relative significance of process parameters and their influence on kerf properties are identified on the basis of analysis of variance. It is found that water pressure and traverse rate are most significant parameters followed by stand-off distance. On the basis of experimental analysis, regression models are developed to predict kerf taper and depth of cut. The models are developed with respect to significant parameters, interaction and quadratic terms. It is found that model predictions are in congruence with experimental results. Multi-response optimization of process parameters is also performed using desirability approach in order to minimize kerf taper and maximize depth of cut. Kerf wall features of machined surfaces are observed using scanning electron microscope. The findings of present study are useful to improve kerf properties in abrasive water jet machining of PZT ceramic materials.

  19. Crack detection of railway turnouts using PZT sensors (presentation video)

    Science.gov (United States)

    Ni, Yiqing; Li, Z. G.; Wu, F.

    2014-05-01

    Railway turnouts (railroad switches) are the weakest components of a rail track system. Cracks may occur in the railway turnouts due to cyclic loadings and impact loadings imposed by passing trains. It is of great significance to continuously monitor the health condition of the railway turnouts and promptly detect crack once it initiates. It is well-known that acoustic emission (AE) signals are generated when a crack initiates and propagates. Detecting the high-frequency AE signals by piezoelectric sensors can help identify the crack and its location. This paper reports the design and implementation of a PZT-based system for crack monitoring of railway turnouts. This online monitoring system is activated for signal collection by a trigger system when a train is arriving to pass through the instrumented railway turnout. It mainly detects the AE signals generated when a crack initiates during the train passage or when the initiated crack expands during the passage of a heavy haul wagon. This system has been installed on a railroad line for over one year and has successfully detected the damage occurring at a railroad switch during its service period. This paper also briefs a guided-wave-based system for monitoring of micro-cracks in rail tracks by integrating FBG and PZT sensors.

  20. A biaxial PZT optical scanner for pico-projector applications

    Science.gov (United States)

    Ikegami, K.; Koyama, T.; Saito, T.; Yasuda, Y.; Toshiyoshi, H.

    2015-02-01

    We report a newly developed two-dimensional MEMS optical scanner based on the ADRIP (Arc Discharge Reactive Ion-Plating) deposited piezoelectric PZT film of typical 4 μm. A circular mirror of 1.2 mm in diameter is suspended within a pair of resonant mechanism that oscillates at 25 kHz for ±12° mechanical angle with a typical voltage of 10 V. A gimbal plate including the mirror is supported with another pair of meandering suspensions to tilt the plate in the orthogonal direction at 60 Hz for the off-resonant vertical motion of ±8° mechanical. Overall power consumption of the piezoelectric actuation was 100 mW or less. As a mechanical reinforce, a rib-structure was designed on the backside of the mirror by using a structural optimization tool TOSCA to suppress the dynamic curvature to 100 nm or less. A piezoelectric sensor was also integrated in the identical PZT film after optimizing the electrode shape to pick up the mechanical angle of the scanner and to give a trigger signal to the control system. A plug-in type pico-projector optics and electronics has been assembled in a 7.5 cm × 12 cm × 5 cm volume with RGB lasers to demonstrate a HD (high definition) class image projection of 720 horizontal lines. The fundamental resonance of the entire scanner mechanism was made to be 1 kHz or higher, thereby exhibiting a compatibility with vehicle applications.

  1. Impedance Based Characterization of a High-Coupled Screen Printed PZT Thick Film Unimorph Energy Harvester

    DEFF Research Database (Denmark)

    Lei, Anders; Xu, R.; Borregaard, L. M.

    2014-01-01

    . This approach leads to simple closed form expressions for peak power frequency, optimal load, and output power without a tedious mathematical derivative approach. The closed form expressions are validated against the exact numerical solution. The electromechanical model contains a set of only five lumped......The single degree of freedom mass-spring-damper system is the most common approach for deriving a full electromechanical model for the piezoelectric vibration energy harvester. In this paper, we revisit this standard electromechanical model by focusing on the impedance of the piezoelectric device...... parameters which, by means of the piezoelectric impedance expression, all can be determined accurately by electrical measurements. It is shown how four of five lumped parameters can be determined from a single impedance measurement scan, considerably reducing the characterization effort. The remaining...

  2. KNN/BNT Composite Lead-Free Films for High-Frequency Ultrasonic Transducer Applications

    Science.gov (United States)

    Lau, Sien Ting; Ji, Hong Fen; Li, Xiang; Ren, Wei; Zhou, Qifa; Shung, K. Kirk

    2011-01-01

    Lead-free K0.5Na0.5NbO3/Bi0.5Na0.5TiO3 (KNN/BNT) films have been fabricated by a composite sol-gel technique. Crystalline KNN fine powder was dispersed in the BNT precursor solution to form a composite slurry which was then spin-coated onto a platinum-buffered Si substrate. Repeated layering and vacuum infiltration were applied to produce 5-μm-thick dense composite film. By optimizing the sintering temperature, the films exhibited good dielectric and ferroelectric properties comparable to PZT films. A 193-MHz high-frequency ultrasonic transducer fabricated from this composite film showed a −6-dB bandwidth of approximately 34%. A tungsten wire phantom was imaged to demonstrate the capability of the transducer. PMID:21244994

  3. Modeling of Magnetoelectric Interaction in Magnetostrictive-Piezoelectric Composites

    Directory of Open Access Journals (Sweden)

    M. I. Bichurin

    2012-01-01

    Full Text Available The paper dwells on the theoretical modeling of magnetoelectric (ME effect in layered and bulk composites based on magnetostrictive and piezoelectric materials. Our analysis rests on the simultaneous solution of elastodynamic or elastostatic and electro/magnetostatic equations. The expressions for ME coefficients as the functions of material parameters and volume fractions of components are obtained. Longitudinal, transverse, and in-plane cases are considered. The use of the offered model has allowed to present the ME effect in ferrite cobalt-barium titanate, ferrite cobalt-PZT, ferrite nickel-PZT, and lanthanum strontium manganite-PZT composites adequately.

  4. Dielectric enhancement of PbZr{sub 0.3}Ti{sub 0.7}O{sub 3}/LaNiO{sub 3} multilayer thick film

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Yasong; Chen, Xiaoyang; Habibul, Arzigul; Zhang, Danyang; Yu, Ping [College of Materials Science and Engineering, Sichuan University, Chengdu, 610064 (China)

    2016-08-15

    Multilayer thick films (∝4 μm) with compositional PbZr{sub 0.3}Ti{sub 0.7}O{sub 3}/LaNiO{sub 3} layers and one-layer PZT thick films were prepared on the silicon substrate by radio-frequency magnetron sputtering. PbZr{sub 0.3}Ti{sub 0.7}O{sub 3}/LaNiO{sub 3} multilayer thick film are characterized by highly preferential (100)-oriented growth and columnar microstructure due to alternately introducing LaNiO{sub 3} seeding layers. The effects of LaNiO{sub 3} layers on microstructure and electrical properties of PbZr{sub 0.3}Ti{sub 0.7}O{sub 3} thick films were investigated in detail. The results show that both PZT and PbZr{sub 0.3}Ti{sub 0.7}O{sub 3}/LaNiO{sub 3} multilayer thick film were pure perovskite crystalline phase. The PbZr{sub 0.3}Ti{sub 0.7}O{sub 3} film texture was dense and well adhered on the LaNiO{sub 3} layer. PbZr{sub 0.3}Ti{sub 0.7}O{sub 3}/LaNiO{sub 3} multilayer thick film possessed obvious enhanced dielectric properties compared with PZT thick film: ε{sub r} ∝2450 (10 kHz) and tanδ ∝0.02 (10 kHz). Rayleigh law was used to analysis the behavior of the enhanced dielectric properties and the pinched-shaped polarization-electric field hysteresis loops. The larger Rayleigh parameter, α ∝51.1408 cm kV{sup -1} (1 kHz) indicates the larger extrinsic contribution to permittivity and strong domain-wall-defect charge interaction. The leakage current behaviors of the multilayer thick film were also investigated in detail. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Thick film hydrogen sensor

    Science.gov (United States)

    Hoffheins, Barbara S.; Lauf, Robert J.

    1995-01-01

    A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors.

  6. Compositional Effects on Electromechanical Degradation of RAINBOW Actuators

    Science.gov (United States)

    Dausch, David E.; Wise, Stephanie A.

    1998-01-01

    The effect of ceramic composition on the electromechanical displacement degradation of RAINBOW (Reduced and Internally Biased Oxide Wafer) actuators was investigated. RAINBOWs were fabricated from commercially available PZT-5H and PZT-5A piezoelectric disks as well as from tape cast PLZT piezoelectric 7/65/35 and electrostrictive 9/65/35 compositions. Displacement properties were measured at low electric fields (10 to 13 kV/cm) under loads of 0 to 500 g, and displacement degradation as a function of time was observed over 107 cycles. The PZT-5A and PLZT 9/65/35 compositions exhibited minimal decrease in displacement when load was applied. Furthermore, these compositions retained approximately 65 percent of their initial displacement after 10(exp 7) cycles under a load of 300 g. PZT-5H and PLZT 7/65/35 degraded completely under these conditions.

  7. Behaviour of a new composite mesh for the repair of full-thickness abdominal wall defects in a rabbit model.

    Directory of Open Access Journals (Sweden)

    Gemma Pascual

    Full Text Available INTRODUCTION: Composite biomaterials designed for the repair of abdominal wall defects are composed of a mesh component and a laminar barrier in contact with the visceral peritoneum. This study assesses the behaviour of a new composite mesh by comparing it with two latest-generation composites currently used in clinical practice. METHODS: Defects (7x5cm created in the anterior abdominal wall of New Zealand White rabbits were repaired using a polypropylene mesh and the composites: Physiomesh(TM; Ventralight(TM and a new composite mesh with a three-dimensional macroporous polyester structure and an oxidized collagen/chitosan barrier. Animals were sacrificed on days 14 and 90 postimplant. Specimens were processed to determine host tissue incorporation, gene/protein expression of neo-collagens (RT-PCR/immunofluorescence, macrophage response (RAM-11-immunolabelling and biomechanical resistance. On postoperative days 7/14, each animal was examined laparoscopically to quantify adhesions between the visceral peritoneum and implant. RESULTS: The new composite mesh showed the lowest incidence of seroma in the short term. At each time point, the mesh surface covered with adhesions was greater in controls than composites. By day 14, the implants were fully infiltrated by a loose connective tissue that became denser over time. At 90 days, the peritoneal mesh surface was lined with a stable mesothelium. The new composite mesh induced more rapid tissue maturation than Physiomesh(TM, giving rise to a neoformed tissue containing more type I collagen. In Ventralight(TM the macrophage reaction was intense and significantly greater than the other composites at both follow-up times. Tensile strengths were similar for each biomaterial. CONCLUSIONS: All composites showed optimal peritoneal behaviour, inducing good peritoneal regeneration and scarce postoperative adhesion formation. A greater foreign body reaction was observed for Ventralight(TM. All composites induced

  8. STACKiNG SEQUENCE OPTiMiZATiON OF COMPOSiTE BEAMS WiTH DiFFERENT LAYER THiCKNESSES

    Directory of Open Access Journals (Sweden)

    Fatih Karaçam

    2015-05-01

    Full Text Available In this study, stacking sequence optimization of composite beams with different layer thicknesses is investigated for various boundary conditions. A unified shear deformation theory is used for analytical solution. The optimization process is carried out in order to obtain the minimum deflection parameters for Clamped-Free (C-F, Clamped-Clamped (C-C and simply supported (S-S boundary conditions under a uniform distributed load by use of genetic algorithm for a specific number of population and generation. Finally, among all possible combinations of layer thicknesses, the one giving the minimum deflection parameter and corresponding stacking sequence is chosen. The minimum values and corresponding stacking sequences are presented for different boundary conditions.

  9. Determination of Interlaminar Toughness of IM7/977-2 Composites at Temperature Extremes and Different Thicknesses

    Science.gov (United States)

    Johnson, W. S.; Pavlick, M. M.; Oliver, M. S.

    2005-01-01

    Composite materials are being used in the aerospace industry as a means of reducing vehicle weight. In particular, polymer matrix composites (PMC) are good candidates due to their high strength-to-weight and high stiffness-to-weight ratios. Future reusable space launch vehicles and space exploration structures will need advanced light weight composites in order to minimize vehicle weight while demonstrating robustness and durability, guaranteeing high factors of safety. In particular, the implementation of composite cryogenic propellant fuel tanks (cryotanks) for future reusable launch vehicles (RLVs) could greatly reduce the vehicle's weight versus identically sized cryotanks constructed of metallic materials. One candidate composite material for future cryotank designs is IM7/977-2, which is a graphite/epoxy system. A successful candidate must demonstrate reasonable structural properties over a wide range of temperatures. Since the matrix material is normally the weak link in the composite, tests that emphasize matrix-dominated behavior need to be conducted. Therefore, the objective of this work is to determine the mode I interlaminar fracture toughness of "unidirectional" 8-ply and 16-ply IM7/977-2 through experimental testing. Tests were performed at -196 degrees Celsius (-320 degrees Fahrenheit), 22 degrees Celsius (72 degrees Fahrenheit), 93 degrees Celsius (200 degrees Fahrenheit) and 160 degrees C (320 degrees Fahrenheit). Low temperature testing was completed while the specimen was submerged in a liquid nitrogen bath. High temperature testing was completed in a temperature-controlled oven.

  10. Dual-energy X-ray absorptiometry, skinfold thickness and waist circumference for assessing body composition in ambulant and non-ambulant wheelchair games players

    Directory of Open Access Journals (Sweden)

    Annika eWillems

    2015-11-01

    Full Text Available Field-based assessments provide a cost–effective and accessible alternative to dual-energy X-ray absorptiometry (DXA for practitioners determining body composition in athletic populations. It remains unclear how the range of physical impairments classifiable in wheelchair sports may affect the utility of field-based body composition techniques. The present study assessed body composition using DXA in 14 wheelchair games players who were either wheelchair dependent (non-walkers; n =7 or relied on a wheelchair for sports participation only (walkers; n =7. Anthropometric measurements were used to predict body fat percentage with existing regression equations established for able-bodied persons by Sloan & Weir, Durnin & Womersley, Lean et al, Gallagher et al and Pongchaiyakul et al. In addition, linear regression analysis was performed to calculate the association between body fat percentage and BMI, waist circumference, sum of 6 skinfold thicknesses and sum of 8 skinfold thicknesses. Results showed that non-walkers had significantly lower total lean tissue mass (46.2±=6.6 kg vs. 59.4±8.2 kg, P =.006 and total body mass (65.8 ±4.2 kg vs. 79.4 ±14.9 kg; P =0.05 than walkers. Body fat percentage calculated from most existing regression equations was significantly lower than that from DXA, by 2 to 9% in walkers and 8 to14% in non-walkers. Of the anthropometric measurements, the sum of 8 skinfold thicknesses had the lowest standard error of estimation in predicting body fat content. In conclusion, existing anthropometric equations developed in able-bodied populations substantially underestimated body fat content in wheelchair athletes, particularly non-walkers. Impairment specific equations may be needed in wheelchair athletes.

  11. Dual-Energy X-Ray Absorptiometry, Skinfold Thickness, and Waist Circumference for Assessing Body Composition in Ambulant and Non-Ambulant Wheelchair Games Players.

    Science.gov (United States)

    Willems, Annika; Paulson, Thomas A W; Keil, Mhairi; Brooke-Wavell, Katherine; Goosey-Tolfrey, Victoria L

    2015-01-01

    Field-based assessments provide a cost-effective and accessible alternative to dual-energy X-ray absorptiometry (DXA) for practitioners determining body composition in athletic populations. It remains unclear how the range of physical impairments classifiable in wheelchair sports may affect the utility of field-based body composition techniques. The present study assessed body composition using DXA in 14 wheelchair games players who were either wheelchair dependent (non-walkers; n = 7) or relied on a wheelchair for sports participation only (walkers; n = 7). Anthropometric measurements were used to predict body fat percentage with existing regression equations established for able-bodied persons by Sloan and Weir, Durnin and Womersley, Lean et al, Gallagher et al, and Pongchaiyakul et al. In addition, linear regression analysis was performed to calculate the association between body fat percentage and BMI, waist circumference, sum of 6 skinfold thickness and sum of 8 skinfold thickness. Results showed that non-walkers had significantly lower total lean tissue mass (46.2 ± 6.6 kg vs. 59.4 ± 8.2 kg, P = 0.006) and total body mass (65.8 ± 4.2 kg vs. 79.4 ± 14.9 kg; P = 0.05) than walkers. Body fat percentage calculated from most existing regression equations was significantly lower than that from DXA, by 2 to 9% in walkers and 8 to 14% in non-walkers. Of the anthropometric measurements, the sum of 8 skinfold thickness had the lowest standard error of estimation in predicting body fat content. In conclusion, existing anthropometric equations developed in able-bodied populations substantially underestimated body fat content in wheelchair athletes, particularly non-walkers. Impairment specific equations may be needed in wheelchair athletes.

  12. THE INFLUENCE OF Β-PBO2 ON PZT PHASE FORMATION

    Directory of Open Access Journals (Sweden)

    H. Allal

    2015-07-01

    Full Text Available The reactional mechanism of the formation of solid solution lead-zircono-titanate PZT has been studied using β-PbO2, TiO2 and ZrO2 as starting materials. PZT ceramics were prepared by solid state reaction between oxides at different temperatures. After calcination samples are characterized by thermogravimetry (TGA, differential thermal analysis (DTA, differential scanning, Infrared spectroscopy and x-ray diffraction (XRD. Using lead dioxide (β-PbO2 allows PZT powder to be sintered at a temperature as low as 700°C.

  13. Impedance and ferroelectric properties of Sr2+modified PZT-PMN ceramics

    Institute of Scientific and Technical Information of China (English)

    Arvind Kumar; SK Mishra

    2014-01-01

    Sr2+modified polycrystalline PZT-PMN ceramics were synthesized by a semi-wet route. Impedance spectroscopy studies indicate the bulk and grain boundary effects of PZT-PMN material along with the negative temperature coefficient of resistance. The bulk conductiv-ity exhibits an Arrhenius-type thermally activated hopping process which is supported by the AC conductivity behavior as a function of fre-quency and temperature. It is observed that the remnant polarization increases with an increase in the Sr2+content in PZT-PMN.

  14. PZT thin film deposition techniques, properties and its application in ultrasonic MEMS sensors: a review

    Science.gov (United States)

    Shilpa, G. D.; Sreelakshmi, K.; Ananthaprasad, M. G.

    2016-09-01

    This paper describes an overview of the state of art in PbZrxTi1-xO3 (PZT)ferroelectric thin films and its applications in Micro Electro Mechanical Systems (MEMS). First, the deposition techniques and then the important properties of PZT films such as surface morphology polarization and ferroelectric properties are reviewed. Two major deposition techniques such as sol-gel and Magnetron sputtering are given and compared for the film surface morphology and ferroelectric properties. Finally, the application of PZT thin film in MEMS ultrasonic sensors is discussed.

  15. Influences of carbon content and coating carbon thickness on properties of amorphous CoSnO{sub 3}@C composites as anode materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Fuqiang [Key Laboratory of Lithium Battery Materials of Jiangsu Province, Institute of chemical power sources, Soochow University, Suzhou 215006 (China); Fang, Guoqing [Key Laboratory of Lithium Battery Materials of Jiangsu Province, Institute of chemical power sources, Soochow University, Suzhou 215006 (China); Changzhou Institute of Energy Storage Materials and Devices, Changzhou 213000 (China); Zhang, Ruixue [Key Laboratory of Lithium Battery Materials of Jiangsu Province, Institute of chemical power sources, Soochow University, Suzhou 215006 (China); Xu, Yanhui; Zheng, Junwei [Key Laboratory of Lithium Battery Materials of Jiangsu Province, Institute of chemical power sources, Soochow University, Suzhou 215006 (China); College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006 (China); Li, Decheng, E-mail: lidecheng@suda.edu.cn [Key Laboratory of Lithium Battery Materials of Jiangsu Province, Institute of chemical power sources, Soochow University, Suzhou 215006 (China); College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006 (China)

    2014-08-30

    Highlights: • The thickness of carbon coating layers can be successfully controlled through varying molar concentration of aqueous glucose solution. • Coating carbon thickness and carbon content are two important factors on the electrochemical performances of CoSnO3@C. • CoSnO{sub 3}@C under optimized conditions exhibits the optimal balance between the volume buffering effect and reversible capacity. • As-prepared CoSnO{sub 3}@C under optimized conditions shows excellent electrochemical performances, whose reversible capacity could reach 491 mA h g{sup −1} after 100 cycles. - Abstract: A series of core–shell carbon coated amorphous CoSnO{sub 3} (CoSnO{sub 3}@C) with different carbon content are synthesized. Effects of carbon content and coating carbon thickness on the physical and electrochemical performances of the samples were studied in detail. The samples were analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), galvanostatic charge–discharge and AC impedance spectroscopy, respectively. The results indicate that controlling the concentration of aqueous glucose solution influences the generation of in-situ carbon layer thickness. The optimal concentration of aqueous glucose solution, carbon content and carbon layer thickness are suggested as 0.25 M, 35.1% and 20 nm, respectively. CoSnO{sub 3}@C composite prepared under the optimal conditions exhibits excellent cycling performance, whose reversible capacity could reach 491 mA h g{sup −1} after 100 cycles.

  16. Effects of Sr2+substitution on the structural, dielectric, and piezoelectric properties of PZT-PMN ceramics

    Institute of Scientific and Technical Information of China (English)

    Arvind Kumar; S.K. Mishra

    2014-01-01

    This study described the structural, dielectric, and piezoelectric behavior of Pb1-xSrx[(Zr0.52Ti0.48)0.95(Mn1/3Nb2/3)0.05]O3 ceramics (PSZT-PMN, x=0, 0.025, 0.050, and 0.075), prepared by a semi-wet route. X-ray diffraction, dielectric, and piezoelectric investigations were carried out to analyze the crystal structure. The relative dielectric constant and dielectric loss were both calculated as the functions of temperature. The room-temperature dielectric constant reaches a maximum for a Sr2+-modified PZT-PMN ceramic with an x value of 0.050, which corresponds to the morphotropic phase boundary (MPB). Raman spectroscopy studies also confirm the existence of this MPB for x=0.050. The piezoelectric strain coefficients (d33) value shows a maximum response for this composition. In addition, the phase transition temperature decreases significantly when the Sr2+concentration increases in the PZT-PMN ceramics.

  17. Crustal structure of the Altiplano from broadband regional waveform modeling: Implications for the composition of thick continental crust

    Science.gov (United States)

    Swenson, Jennifer L.; Beck, Susan L.; Zandt, George

    2000-01-01

    We have modeled the full waveforms from six intermediate-depth and two shallow earthquakes recorded at regional distances by the BANJO Broadband Andean Joint Experiment (BANJO) and Seismic Exploration of the Deep Altiplano (SEDA) portable seismic networks in the central Andes. In this study we utilize data from those BANJO and SEDA stations located within the Altiplano and Eastern Cordillera. We used reflectivity synthetic seismograms and a grid search to constrain four parameters of the Altiplano-Eastern Cordillera lithosphere: crustal thickness, average crustal velocity (Vp), and crustal and upper mantle Poisson's ratios (σcrust and σmantle). Using our grid search, we investigated the crustal and upper mantle structure along 36 individual event station paths and applied forward modeling to 56 event station paths. Robust models for the Altiplano that provide the best overall fit between the data and synthetic seismograms are characterized by an average Vp of 5.75-6.25 km/s, crustal thicknesses of 60-65 km, σcrust = 0.25, and σmantle = 0.27-0.29. We find a north-south variation in the structure of the Altiplano, with the crust south of the BANJO transect characterized by either lower than average crustal P wave velocities or a slightly higher σcrust relative to crust north of the BANJO transect. These results are consistent with a model of crustal thickening caused predominantly by tectonic shortening of felsic crust, rather than by underplating or magmatic intrusion from the mantle.

  18. NRBS, RBS, TEM and SAED characterisation of sol-gel PZT films

    Energy Technology Data Exchange (ETDEWEB)

    Pantelica, D. [HH National Institute of Physics and Nuclear Engineering, P.O. Box MG-6 RO-077125 Bucharest-Magurele (Romania); Vasiliu, F. [National Institute of Materials Physics, P.O. Box MG-7, RO-077125 Bucharest-Magurele (Romania)]. E-mail: fvasiliu@infim.ro; Ionescu, P. [HH National Institute of Physics and Nuclear Engineering, P.O. Box MG-6 RO-077125 Bucharest-Magurele (Romania); Negoita, F. [HH National Institute of Physics and Nuclear Engineering, P.O. Box MG-6 RO-077125 Bucharest-Magurele (Romania)

    2005-10-15

    TEM-SAED investigations were performed on PZT films, to elucidate the role of pyrolysis conditions on orientation selection. For short pyrolysis, occurrence of the metastable fluorite and the interfacial Pt {sub x}Pb template layer are the factors inducing the (1 1 1) PZT orientation. For advanced pyrolysis, the TiO{sub 2} interfacial layer could be responsible for (1 0 0) PZT strong orientation. To further investigate the stoichiometry of PZT and interfacial layers, we performed heavy ion RBS and NRBS measurements. Only a substoichiometric TiO{sub 2-x} layer is found for the short pyrolized film whereas two Ti and O rich layers were observed for advanced pyrolysis. The thicker oxygen rich TiO{sub 2-x} bottom layer, observed by TEM and NRBS analysis, could lead to <1 0 0> texture, observed for oxidizing conditions at the interface during pyrolysis.

  19. High Quality Factor Silicon Cantilever Driven by PZT Actuator for Resonant Based Mass Detection

    CERN Document Server

    Lu, Jian; Zhang, Yi; Mihara, Takashi; Itoh, Toshihiro; Maeda, Ryutaro

    2008-01-01

    A high quality factor (Q-factor) piezoelectric lead zirconat titanate (PZT) actuated single crystal silicon cantilever was proposed in this paper for resonant based ultra-sensitive mass detection. Energy dissipation from intrinsic mechanical loss of the PZT film was successfully compressed by separating the PZT actuator from resonant structure. Excellent Q-factor, which is several times larger than conventional PZT cantilever, was achieved under both atmospheric pressure and reduced pressures. For a 30 micrometer-wide 100 micrometer-long cantilever, Q-factor was measured as high as 1113 and 7279 under the pressure of 101.2 KPa and 35 Pa, respectively. Moreover, it was found that high-mode vibration can be realized by the cantilever for the pursuit of great Q-factor, while support loss became significant because of the increased vibration amplitude at the actuation point. An optimized structure using node-point actuation was suggested then to suppress corresponding energy dissipation.

  20. Feasibility Verification of Mountable PZT-Interface for Impedance Monitoring in Tendon-Anchorage

    Directory of Open Access Journals (Sweden)

    Thanh-Canh Huynh

    2015-01-01

    Full Text Available This study has been motivated to numerically evaluate the performance of the mountable PZT-interface for impedance monitoring in tendon-anchorage. Firstly, electromechanical impedance monitoring and feature classification methods are outlined. Secondly, a structural model of tendon-anchorage subsystem with mountable PZT-interface is designed for impedance monitoring. Finally, the feasibility of the mountable PZT-interface is numerically examined. A finite element (FE model is designed for the lab-scaled tendon-anchorage. The FE model of the PZT-interface is tuned as its impedance signatures meet the experimental test results at the same frequency ranges and also with identical patterns. Equivalent model properties of the FE model corresponding to prestress forces inflicted on the lab-tested structure are identified from the fine-tuning practice.

  1. Room-temperature poling of PbTiO3/Pb(Zr,Ti)O3 sol-gel composite films by pulse discharge

    Science.gov (United States)

    Kouyama, Hikaru; Kibe, Taiga; Fujimoto, Shota; Namihira, Takao; Kobayashi, Makiko

    2016-07-01

    The PbTiO3/Pb(Zr,Ti)O3 (PT/PZT) sol-gel composite is a promising piezoelectric material because of its high piezoelectricity and temperature stability up to 360 °C. However, the poling of PT/PZT required high temperature owing to the high coercive field of PT, which made the poling of PT/PZT troublesome. In this research, conventional DC corona poling and pulse discharge at room temperature were attempted for PT/PZT samples. As a result, PT/PZT poled by pulse discharge generation at room temperature showed comparable ultrasonic responses to that poled by DC corona discharge generation at a high temperature. Therefore, room-temperature poling of PT/PZT was successfully carried out by pulse discharge, and poling time was markedly reduced from ˜15 min to 15 s.

  2. Composition Distribution, Damping and Thermal Properties of the Thickness-Continuous Gradient Epoxy/Polyurethane Interpenetrating Polymer Networks

    Directory of Open Access Journals (Sweden)

    Xuesong Lv

    2017-01-01

    Full Text Available A thickness gradient interpenetrating polymer network (IPN was easily created that takes advantage of the relatively poor compatibility and curing rates discrepancy between epoxy (EP and polyurethane (PU. Ultraviolet absorption spectrum (UV-Vis, thermogravimetric (TG, Differential scanning calorimetry (DSC, Dynamic thermomechanical analysis (DMA, Atomic force microscope (AFM and water contact angle were adopted to characterize this IPN structure. We found that the absorption in visible light region, glass-transition temperatures (Tg, thermal decomposition temperatures (Td and Derjaguin–Muller–Toporov (DMT modulus were increasing along with the gradient direction from bottom side to top side of the IPN. While the absorption in ultraviolet region and adhesion force were decreasing along with the gradient direction from bottom side to top side of the IPN. DMA analysis demonstrates that this continuous gradient IPN has a good balance between the damping temperature range and the loss factor which is suitable for using as a self-supporting damping structure.

  3. Optimization of wall thickness and lay-up for the shell-like composite structure loaded by non-uniform pressure field

    Science.gov (United States)

    Shevtsov, S.; Zhilyaev, I.; Oganesyan, P.; Axenov, V.

    2017-01-01

    The glass/carbon fiber composites are widely used in the design of various aircraft and rotorcraft components such as fairings and cowlings, which have predominantly a shell-like geometry and are made of quasi-isotropic laminates. The main requirements to such the composite parts are the specified mechanical stiffness to withstand the non-uniform air pressure at the different flight conditions and reduce a level of noise caused by the airflow-induced vibrations at the constrained weight of the part. The main objective of present study is the optimization of wall thickness and lay-up of composite shell-like cowling. The present approach assumes conversion of the CAD model of the cowling surface to finite element (FE) representation, then its wind tunnel testing simulation at the different orientation of airflow to find the most stressed mode of flight. Numerical solutions of the Reynolds averaged Navier-Stokes (RANS) equations supplemented by k-w turbulence model provide the spatial distributions of air pressure applied to the shell surface. At the formulation of optimization problem the global strain energy calculated within the optimized shell was assumed as the objective. A wall thickness of the shell had to change over its surface to minimize the objective at the constrained weight. We used a parameterization of the problem that assumes an initiation of auxiliary sphere with varied radius and coordinates of the center, which were the design variables. Curve that formed by the intersection of the shell with sphere defined boundary of area, which should be reinforced by local thickening the shell wall. To eliminate a local stress concentration this increment was defined as the smooth function defined on the shell surface. As a result of structural optimization we obtained the thickness of shell's wall distribution, which then was used to design the draping and lay-up of composite prepreg layers. The global strain energy in the optimized cowling was reduced in2

  4. Impedance monitoring at tendon-anchorage via mountable PZT interface and temperature-effect compensation

    Science.gov (United States)

    Huynh, Thanh-Canh; Nguyen, Tuan-Cuong; Choi, Sang-Hoon; Kim, Jeong-Tae

    2016-04-01

    In this study, the pre-stress force in pre-stressed concrete (PSC) girders is monitored via mountable PZT interface under varying temperature. Firstly, an impedance-based technique using mountable PZT interface is proposed for pre-stress-loss monitoring in tendon-anchorage systems. A cross correlation-based temperature-effect compensation algorithm using an effective frequency shift (EFS) of impedance signatures is visited. Secondly, lab-scale experiments are performed on a PSC girder instrumented with a mountable PZT interface at tendon-anchorage. A series of temperature variation and pre-stress-loss events are simulated for the lab-scale PSC girder. Thirdly, the feasibility of the mountable PZT interface for pre-stress-loss monitoring in tendon-anchorage is experimentally verified under constant temperature conditions. Finally, the PZT interface device is examined for pre-stress-loss monitoring under temperature changes to validate its applicability. The temperature effect on impedance signatures is compensated by minimizing cross-correlation deviation between impedance patterns of the mountable PZT interface.

  5. Health monitoring of a continuous rigid frame bridge based on PZT impedance and strain measurements

    Science.gov (United States)

    Zhang, Junbing; Zhu, Hongping; Wang, Dansheng; He, Bo; Zhou, Huaqiang

    2009-07-01

    Critical civil infrastructures such as bridges, dams, and pipelines present a major investment and their safety and security affect the life of citizens and national economic development. So it is very important for engineers and researchers to monitor their integrity while in operation and throughout. In recent years, the piezoelectric-ceramic (PZT) patches, which serve both as impedance sensors and actuators, have been increasingly used for structural health monitoring. This paper presents an impedance-based method, which utilizes the electro-mechanical coupling property of PZT sensors. There are a lot of advantages of this method, such as not based on any physical models, sensitive to tiny damage for its high frequency characteristics. An engineering application of this method for health monitoring of a continuous rigid frame bridge is implemented in this study. Some PZT active sensors are embedded into critical sections of the continuous rigid-frame box beam. The electrical admittances of these distributed PZT sensors are measured when the bridge is constructing or suffering from operational loads. For comparison, strain gauges are arranged in adjacent regions of these PZT sensors to obtain the strains of concrete around them at the same time. Based on the admittance sigatures obtained form PZT sensors and the strain measurements of concrete around them, the health status of the bridge is monitored and evaluated successfully.

  6. Evaluation of bond strength and thickness of adhesive layer according to the techniques of applying adhesives in composite resin restorations.

    Science.gov (United States)

    de Menezes, Fernando Carlos Hueb; da Silva, Stella Borges; Valentino, Thiago Assunção; Oliveira, Maria Angélica Hueb de Menezes; Rastelli, Alessandra Nara de Souza; Conçalves, Luciano de Souza

    2013-01-01

    Adhesive restorations have increasingly been used in dentistry, and the adhesive system application technique may determine the success of the restorative procedure. The aim of this study was to evaluate the influence of the application technique of two adhesive systems (Clearfil SE Bond and Adper Scotchbond MultiPurpose) on the bond strength and adhesive layer of composite resin restorations. Eight human third molars were selected and prepared with Class I occlusal cavities. The teeth were restored with composite using various application techniques for both adhesives, according to the following groups (n = 10): group 1 (control), systems were applied and adhesive was immediately light activated for 20 seconds without removing excesses; group 2, excess adhesive was removed with a gentle jet of air for 5 seconds; group 3, excess was removed with a dry microbrushtype device; and group 4, a gentle jet of air was applied after the microbrush and then light activation was performed. After this, the teeth were submitted to microtensile testing. For the two systems tested, no statistical differences were observed between groups 1 and 2. Groups 3 and 4 presented higher bond strength values compared with the other studied groups, allowing the conclusion that excess adhesive removal with a dry microbrush could improve bond strength in composite restorations. Predominance of adhesive fracture and thicker adhesive layer were observed via scanning electron microscopy (SEM) in groups 1 and 2. For groups 3 and 4, a mixed failure pattern and thinner adhesive layer were verified. Clinicians should be aware that excess adhesive may negatively affect bond strength, whereas a thin, uniform adhesive layer appears to be favorable.

  7. Ultrasonic Thickness Measuring Sensor Design for Composite Material%用于复合材料的超声测厚传感器设计

    Institute of Scientific and Technical Information of China (English)

    孟晨光; 金文; 李正旭; 张伟

    2011-01-01

    复合材料作为一种优异的耐磨和耐高温材料,在高温设备热防护、飞机刹车制动盘等军事、特种民用技术等领域有着广泛的应用.为了更好地测量和评定这一类型材料的防护特性,迫切需要一种能够在试验中进行厚度动态测量的传感器.超声式厚度测量传感器具有无损、无放射性的优点,并且可以提供实时动态的测量结果,为这种类型材料的测量提供了强有力的技术手段.介绍此技术原理,并设计一套超声式厚度测量传感器系统.经过理论分析和试验表明,通过此方法的厚度测量精度可以达到1 mm的测量精度,并且设备在恶劣环境下能够稳定可靠地工作.%Composite Material is an excellent type of wearable and high-temperature-resistant material, widely used in military and special civilian technology areas like high-temperature equipment protection and aircraft brake discs, etc. For measuring and assessing the resistant properties of this type of material, a thickness measuring sensor is needed for dynamic thickness measurement during the test. Ultrasonic thickness measuring sensors have nondestructive and non-radioactive properties, and can provide real-time dynamic measurement for this type of material. This article will introduce this method, and design a set of ultrasonic thickness measuring sensor system. Theoretical analysis and tests show that the precision of this thickness measurement reaches 1mm, and the measuring sensor can maintain stable and reliable in bad circumstances.

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

    Science.gov (United States)

    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.

  9. Extremely deep profiling analysis of the atomic composition of thick (>100 μm) GaAs layers within power PIN diodes by secondary ion mass spectrometry

    Science.gov (United States)

    Drozdov, M. N.; Drozdov, Yu. N.; Yunin, P. A.; Folomin, P. I.; Gritsenko, A. B.; Kryukov, V. L.; Kryukov, E. V.

    2016-08-01

    A new opportunity to analyze the atomic composition of thick (>100 μm) epitaxial GaAs layers by SIMS with lateral imaging of the cross section of a structure is demonstrated. The standard geometry of ldepth analysis turns out to be less informative owing to material redeposition from the walls of a crater to its floor occurring when the crater depth reaches several micrometers. The profiles of concentration of doping impurities Te and Zn and concentrations of Al and major impurities in PIN diode layers are determined down to a depth of 130 μm. The element sensitivity is at the level of 1016 at/cm3 (typical for depth analysis at a TOF.SIMS-5 setup), and the resolution is twice the diameter of the probing beam of Bi ions. The possibility of enhancing the depth resolution and the element sensitivity of the proposed analysis method is discussed.

  10. Direct Intracochlear Acoustic Stimulation Using a PZT Microactuator

    Directory of Open Access Journals (Sweden)

    Chuan Luo

    2015-11-01

    Full Text Available Combined electric and acoustic stimulation has proven to be an effective strategy to improve hearing in some cochlear implant users. We describe an acoustic microactuator to directly deliver stimuli to the perilymph in the scala tympani. The 800 µm by 800 µm actuator has a silicon diaphragm driven by a piezoelectric thin film (e.g., lead-zirconium-titanium oxide or PZT. This device could also be used as a component of a bimodal acoustic-electric electrode array. In the current study, we established a guinea pig model to test the actuator for its ability to deliver auditory signals to the cochlea in vivo. The actuator was placed through the round window of the cochlea. Auditory brainstem response (ABR thresholds, peak latencies, and amplitude growth were calculated for an ear canal speaker versus the intracochlear actuator for tone burst stimuli at 4, 8, 16, and 24 kHz. An ABR was obtained after removal of the probe to assess loss of hearing related to the procedure. In some animals, the temporal bone was harvested for histologic analysis of cochlear damage. We show that the device is capable of stimulating ABRs in vivo with latencies and growth functions comparable to stimulation in the ear canal. Further experiments will be necessary to evaluate the efficiency and safety of this modality in long-term auditory stimulation and its ability to be integrated with conventional cochlear implant arrays.

  11. NMR quadruopole spectra of PZT from first-principles

    Science.gov (United States)

    Mao, Dandan; Walter, Eric J.; Krakauer, Henry

    2006-03-01

    High performance piezoelectric materials are disordered alloys, so it can be difficult to determine the local atomic geometry. Recently, high field NMR measurements have shown great promise as a microscopic probe of ABO3 perovskite-based alloys by their ability to resolve line-splittings due to nuclear quadrupolar coupling with the electric field gradient (EFG) at the nucleus. We report first-principles LDA calculations of the EFG's in monoclinic and tetragonal Pb(Zr0.5Ti0.5)O3 systems using the linear augmented planewave (LAPW) method, and we compute NMR static powder spectra for ^91Zr, ^47Ti, and ^17O atoms as a function of applied strain. With decreasing c/a ratio PZT converts from tetragonal to monoclinic symmetry. We observe that the calculated NMR spectra show dramatic deviations with decreasing c/a from that in tetragonal P4mm well before the electric polarization begins to rotate away from the [001] direction. This indicates that NMR measurements can be a very accurate probe of local structural changes in perovskite piezoelectrics. G. L. Hoatson, D. H. Zhou, F. Fayon, D. Massiot, and R. L. Vold, Phys. Rev. B, 66, 224103 (2002).

  12. Recent Progress on PZT Based Piezoelectric Energy Harvesting Technologies

    Directory of Open Access Journals (Sweden)

    Min-Gyu Kang

    2016-02-01

    Full Text Available Energy harvesting is the most effective way to respond to the energy shortage and to produce sustainable power sources from the surrounding environment. The energy harvesting technology enables scavenging electrical energy from wasted energy sources, which always exist everywhere, such as in heat, fluids, vibrations, etc. In particular, piezoelectric energy harvesting, which uses a direct energy conversion from vibrations and mechanical deformation to the electrical energy, is a promising technique to supply power sources in unattended electronic devices, wireless sensor nodes, micro-electronic devices, etc., since it has higher energy conversion efficiency and a simple structure. Up to now, various technologies, such as advanced materials, micro- and macro-mechanics, and electric circuit design, have been investigated and emerged to improve performance and conversion efficiency of the piezoelectric energy harvesters. In this paper, we focus on recent progress of piezoelectric energy harvesting technologies based on PbZrxTi1-xO3 (PZT materials, which have the most outstanding piezoelectric properties. The advanced piezoelectric energy harvesting technologies included materials, fabrications, unique designs, and properties are introduced to understand current technical levels and suggest the future directions of piezoelectric energy harvesting.

  13. Energy Harvesting Using Screen Printed PZT on Silicon

    DEFF Research Database (Denmark)

    Lei, Anders

    as a result. Cleanroom contamination issues in the cantilever etching due to the PZT film is solved with a KOH etch where the wafer front side is protected mechanically. From thorough characterisation of the fabricated harvester, it is validated that the power output can be expressed as a power available term...... and a multiplication factor equal to or less than 1. The available power is proportional to the force acting on the cantilever squared and the inverse of the viscous damping coefficient. The latest fabricated batch of harvesters produced in average 34.5 µW of RMS power over a resistive load of 50 k? with an RMS...... acceleration of 0.5g at 511 Hz. The best performing devices under similar conditions produced 44.9 µW at 543 Hz. Compared to other state of the art miniaturised vibration energy harvesters, the normalised power density for the harvesters fabricated in this work is 3.5 times higher than the next best harvester....

  14. Hair Follicle Morphogenesis in the Treatment of Mouse Full-Thickness Skin Defects Using Composite Human Acellular Amniotic Membrane and Adipose Derived Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Wu Minjuan

    2016-01-01

    Full Text Available Early repair of skin injury and maximal restoration of the function and appearance have become important targets of clinical treatment. In the present study, we observed the healing process of skin defects in nude mice and structural characteristics of the new skin after transplantation of isolated and cultured adipose derived mesenchymal stem cells (ADMSCs onto the human acellular amniotic membrane (AAM. The result showed that ADMSCs were closely attached to the surface of AAM and grew well 24 h after seeding. Comparison of the wound healing rate at days 7, 14, and 28 after transplantation showed that ADMSCs seeded on AAM facilitated the healing of full-thickness skin wounds more effectively as compared with either hAM or AAM alone, indicating that ADMSCs participated in skin regeneration. More importantly, we noticed a phenomenon of hair follicle development during the process of skin repair. Composite ADMSCs and AAM not only promoted the healing of the mouse full-thickness defects but also facilitated generation of the appendages of the affected skin, thus promoting restoration of the skin function. Our results provide a new possible therapy idea for the treatment of skin wounds with respect to both anatomical regeneration and functional restoration.

  15. Hair Follicle Morphogenesis in the Treatment of Mouse Full-Thickness Skin Defects Using Composite Human Acellular Amniotic Membrane and Adipose Derived Mesenchymal Stem Cells

    Science.gov (United States)

    Minjuan, Wu; Jun, Xiong; Shiyun, Shao; Sha, Xu; Haitao, Ni

    2016-01-01

    Early repair of skin injury and maximal restoration of the function and appearance have become important targets of clinical treatment. In the present study, we observed the healing process of skin defects in nude mice and structural characteristics of the new skin after transplantation of isolated and cultured adipose derived mesenchymal stem cells (ADMSCs) onto the human acellular amniotic membrane (AAM). The result showed that ADMSCs were closely attached to the surface of AAM and grew well 24 h after seeding. Comparison of the wound healing rate at days 7, 14, and 28 after transplantation showed that ADMSCs seeded on AAM facilitated the healing of full-thickness skin wounds more effectively as compared with either hAM or AAM alone, indicating that ADMSCs participated in skin regeneration. More importantly, we noticed a phenomenon of hair follicle development during the process of skin repair. Composite ADMSCs and AAM not only promoted the healing of the mouse full-thickness defects but also facilitated generation of the appendages of the affected skin, thus promoting restoration of the skin function. Our results provide a new possible therapy idea for the treatment of skin wounds with respect to both anatomical regeneration and functional restoration. PMID:27597871

  16. Fabrication of sub-micro size PZT array and their ferroelectric properties

    Institute of Scientific and Technical Information of China (English)

    ZHAO Gaoyang; ZHANG Weihua; XU Guomin; DENG Xiaocui; JIANG Bailing; ZHAO Wei

    2006-01-01

    The photosensitive PZT sols and their gel films were prepared by sol-gel process. Based on the photosensitivity of the PZT gel films, two-dimensional (2D) array of the PZT gel film was fabricated using twice-exposure of double-beam interference on the gel film. PZT gel films coated on ITO/quartz substrate were exposed to an interference fringe of 325 He-Cd laser beams, the substrate was rotated by 90° between the first and second irradiation steps. Island type periodic 2D array structures with a pitch of 1 μm and cell size of about 480 nm × 480 nm × 40 nm were formed after the irradiation, and followed by leaching with organic solvent, and then by heat treatment at 600℃ for 15 min. The hysteresis loops of the cell in PZT array were in-situ measured by the online-operation of TF analyzer and atomic force microscope (AFM). The probe can be located on the locked cell of PZT array in the AFM image. The alternating voltage applied to the locked cell is supplied by the TF analyzer through the conductive coating probe, and then the test signal is fed back to the TF analyzer to obtain the hysteresis loop of the locked cell of array in the absence of top electrode. The results show that the sub-micro size PZT arrays prepared in this way are of polarization reversal characteristics with the alternating electric fields, thereby exhibiting obvious ferroelectricity.

  17. Photoluminescence properties of PZT 52/48 synthesized by microwave hydrothermal method using PVA with template

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, G.F., E-mail: guilmina@hotmail.com [Instituto de Quimica, Universidade Estadual Paulista, Departamento de Bioquimica e Tecnologia Quimica, Rua Francisco Degni s/n, Quitandinha, 14800-900 Araraquara, SP (Brazil); Gasparotto, G. [Instituto de Quimica, Universidade Estadual Paulista, Departamento de Bioquimica e Tecnologia Quimica, Rua Francisco Degni s/n, Quitandinha, 14800-900 Araraquara, SP (Brazil); Paris, E.C. [Empresa Brasileira de Pesquisa Agropecuaria, Embrapa Instrumentacao, Rua XV de novembro, 1452, Centro, 13.569-970 Sao Carlos, SP (Brazil); Zaghete, M.A.; Longo, E.; Varela, J.A. [Instituto de Quimica, Universidade Estadual Paulista, Departamento de Bioquimica e Tecnologia Quimica, Rua Francisco Degni s/n, Quitandinha, 14800-900 Araraquara, SP (Brazil)

    2012-01-15

    Lead Titanate Zirconate (PZT) perovskite powders were synthesized by microwave hydrothermal method (M-H) at 180 {sup o}C for different time periods (2, 4, 8 and 12 h) with the presence of aqueous polyvinyl alcohol (PVA) solution 0.36 g L{sup -1}. The X-Ray diffraction (XRD), SE-FEG as well as the measurements of photoluminescence (PL) emission were used for monitoring the formation of a perovskite phase with random polycrystalline distortion in the structure. Emission spectra with fixed excitation wavelength of 350 nm showed higher value for the powder obtained after undergoing 8 h of treatment. A theoretical model derived from previous calculations allows us to discuss the origin of photoluminescence emission in the powders, which can be further related to the local disorder in the network of both ZrO{sub 6} and TiO{sub 6} octahedral, and dodecahedral PbO{sub 12}. The new morphology initially observed from the PZT perovskite crystal growth bearing the shape of fine plates is found to be directly related to photoluminescence emission with energy lower than that present in the PZT with cube-like morphology that emits in 560 nm. - Highlights: > This work details the efficiency of microwave hydrothermal synthesis in obtaining PZT powders. > PVA is used as a crystallization agent of PZT particles. > PZT particles presented photoluminescent (PL) behavior. > There aren't previous reports of photoluminescent PZT obtained by microwave hydrothermal synthesis. > Photoluminescence is one more interesting property for technological applications this material.

  18. Comparison of bioelectrical impedance with skinfold thickness and X-ray absorptiometry to measure body composition in HIV-infected with lipodistrophy.

    Science.gov (United States)

    Siqueira Vassimon, H; Siqueira Vasimon, H; Jordao, A A; Albuquerque de Paula, F J; Artioli Machado, A; Pontes Monteiro, J

    2011-01-01

    Human immunodeficiency vírus (HIV)-associated lipodystrophy syndrome (LS) includes body composition and metabolic alterations. Lack of validated criteria and tools make difficult to evaluate body composition in this group. The aim of the study was to compare different methods to evaluate body composition between Brazilians HIV subjects with (HIV+LIPO+) or without LS (HIV+LIPO-) and healthy subjects (Control). in a cross-sectional analyses, body composition was measured by bioelectrical impedance analysis (BIA), skinfold thickness (SF) and dual-energy x-ray absorptiometry (DXA) in 10 subjects from HIV+LIPO+ group; 22 subjects from HIV+LIPO- group and 12 from Control group. There were no differences in age and body mass index (BMI) between groups. The fat mass (FM) (%) estimated by SF did not correlate with DXA in HIV+LIPO+ group (r = 0,46/ p > 0,05) and had fair agreement in both HIV groups (HIV+LIPO+ =0,35/ HIV+ LIPO- = 0,40). BIA had significant correlation in all groups (p < 0,05) and strong agreement, meanly in HIV groups, for FM (HIV+LIPO+ = 0,79/ HIV+LIPO- = 0,85 / Control = 0,60) and for fat free mass (FFM) (HIV+LIPO+ = 0,93 / HIV+LIPO- = 0,92 / Control = 0,73). Total fat mass can be measured by BIA with good precision, but not by SF in HIV-infected patients with LS. Segmental BIA, triciptal SF, circumferences of arms, waist and legs maybe alternatives that need more studies.

  19. High-performance piezoelectric thick film based energy harvesting micro-generators for MEMS

    DEFF Research Database (Denmark)

    Zawada, Tomasz; Hansen, Karsten; Lou-Moeller, Rasmus

    2010-01-01

    Energy harvesting, known also as energy scavenging, covers a great body of technologies and devices that transform low grade energy sources such as solar energy, environmental vibrations, thermal energy, human motion into usable electrical energy. In this paper vibrations are used as energy source...... and are transformed by the energy harvesting micro-generator into usable electrical signal. The micro-generator comprises a silicon cantilever with integrated InSensor® TF2100 PZT thick film deposited using screen-printing. The output power versus frequency and electrical load has been investigated. Furthermore......, devices based on modified, pressure treated thick film materials have been tested and compared with the commercial InSensor® TF2100 PZT thick films. It has been found that the structures based on the pressure treated materials exhibit superior properties in terms of energy output....

  20. Using Fourier and Taylor series expansion in semi-analytical deformation analysis of thick-walled isotropic and wound composite structures

    Directory of Open Access Journals (Sweden)

    Jiran L.

    2016-06-01

    Full Text Available Thick-walled tubes made from isotropic and anisotropic materials are subjected to an internal pressure while the semi-analytical method is employed to investigate their elastic deformations. The contribution and novelty of this method is that it works universally for different loads, different boundary conditions, and different geometry of analyzed structures. Moreover, even when composite material is considered, the method requires no simplistic assumptions. The method uses a curvilinear tensor calculus and it works with the analytical expression of the total potential energy while the unknown displacement functions are approximated by using appropriate series expansion. Fourier and Taylor series expansion are involved into analysis in which they are tested and compared. The main potential of the proposed method is in analyses of wound composite structures when a simple description of the geometry is made in a curvilinear coordinate system while material properties are described in their inherent Cartesian coordinate system. Validations of the introduced semi-analytical method are performed by comparing results with those obtained from three-dimensional finite element analysis (FEA. Calculations with Fourier series expansion show noticeable disagreement with results from the finite element model because Fourier series expansion is not able to capture the course of radial deformation. Therefore, it can be used only for rough estimations of a shape after deformation. On the other hand, the semi-analytical method with Fourier Taylor series expansion works very well for both types of material. Its predictions of deformations are reliable and widely exploitable.

  1. Development of valve-less tube-type micropump with PZT actuator

    Science.gov (United States)

    Tsuchiya, Kazuyoshi; Morishima, Akifumi; Takamata, Atsushi; Uetsuji, Yasutomo; Nakamachi, Eiji

    2008-12-01

    The medical devices such as a micropump to extract blood through a tube have a structure which needle and pump part are mutually separated. Therefore, it is not easy to make smaller than the conventional pump. In this research, we aim to develop the pump combined with a tube as a final purpose. In this study, ring type PZT elements are mounted on the surface of the silicone tube, and the stationary waves are generated in the tube by the vibration of those PZT on the tube verified by changing the AC voltage. The waves generated by the collision of large and small stationary waves are synthesized, and then the wave becomes a progressive wave with an elliptic motion in the tube. The flow function demonstrated by the tube type micropump was evaluated and the flow velocities were increased 2.78% and decreased 1.79%. On the other hand, we have a technique to produce a titanium microtube by using RF magnetron sputtering deposition technique. A Titanium micro tube with the size of a female mosquito's labium (60µm external and 25μm internal diameter) was produced by the sputter deposition method. In order to deposit PZT thin film on the titanium micro tube, the thin film process is used. The thin film deposition conditions of the PZT thin film are investigated and the characteristic of the PZT thin films are evaluated.

  2. TECHNICAL NOTE: The development of a PZT-based microdrive for neural signal recording

    Science.gov (United States)

    Park, Sangkyu; Yoon, Euisung; Lee, Sukchan; Shin, Hee-sup; Park, Hyunjun; Kim, Byungkyu; Kim, Daesoo; Park, Jongoh; Park, Sukho

    2008-04-01

    A hand-controlled microdrive has been used to obtain neural signals from rodents such as rats and mice. However, it places severe physical stress on the rodents during its manipulation, and this stress leads to alertness in the mice and low efficiency in obtaining neural signals from the mice. To overcome this issue, we developed a novel microdrive, which allows one to adjust the electrodes by a piezoelectric device (PZT) with high precision. Its mass is light enough to install on the mouse's head. The proposed microdrive has three H-type PZT actuators and their guiding structure. The operation principle of the microdrive is based on the well known inchworm mechanism. When the three PZT actuators are synchronized, linear motion of the electrode is produced along the guiding structure. The electrodes used for the recording of the neural signals from neuron cells were fixed at one of the PZT actuators. Our proposed microdrive has an accuracy of about 400 nm and a long stroke of about 5 mm. In response to formalin-induced pain, single unit activities are robustly measured at the thalamus with electrodes whose vertical depth is adjusted by the microdrive under urethane anesthesia. In addition, the microdrive was efficient in detecting neural signals from mice that were moving freely. Thus, the present study suggests that the PZT-based microdrive could be an alternative for the efficient detection of neural signals from mice during behavioral states without any stress to the mice.

  3. Development of PZT-excited stroboscopic shearography for full-field nondestructive evaluation

    Science.gov (United States)

    Asemani, Hamidreza; Park, Jinwoo; Lee, Jung-Ryul; Soltani, Nasser

    2017-05-01

    Nondestructive evaluation using shearography requires a way to stress the inspection target. This technique is able to directly measure the displacement gradient distribution on the object surface. Shearography visualizes the internal structural damages as the anomalous pattern in the shearograpic fringe pattern. A piezoelectric (PZT) excitation system is able to generate loadings in the vibrational, acoustic, and ultrasonic regimes. In this paper, we propose a PZT-excited stroboscopic shearography. The PZT excitation could generate vibrational loading, a stationary wavefield, and a nonstationary propagation wave to fulfill the external loading requirement of shearography. The sweeping of the PZT excitation frequency, the formation of a standing wave, and a small shearing to suppress the incident wave were powerful controllable tools to detect the defects. The sweeping of the PZT excitation frequency enabled us to determine one of the defect-sensitive frequencies almost in real time. In addition, because the defect sensitive frequencies always existed in wide and plural ranges, the risk of the defect being overlooked by the inspector could be alleviated. The results of evaluation using stroboscopic shearography showed that an artificial 20 mm-diameter defect could be visualized at the excitation frequencies of 5-8 kHz range and 12.5-15.5 kHz range. This technique provided full field reliable and repeatable inspection results. Additionally, the proposed method overcame the important drawback of the time-averaged shearography, being required to identify the resonance vibration frequency sensitive to the defect.

  4. Pengaruh ketebalan bahan dan lamanya waktu penyinaran terhadap kekerasan permukaan resin komposit sinar (Effects of materials thickness and length of light exposure on the surface hardness light-cured composite resins

    Directory of Open Access Journals (Sweden)

    Annette Alexandra Susanto

    2006-03-01

    Full Text Available Light-cured resin composite is one of the most commonly used molding materials due to its easy-to-mold characteristic. Nevertheless, care must be taken while treating this material, especially with respect to material thickness and how long it is exposed to light. Failure to treat the material with these optimal parameters will result in undesired hardness. To determine the most favorable value of these two parameters, an experiment was done with 3 different material thicknesses, and 3 different exposure times. After the sample of the resin composite was removed from its molding, it was stored under humid condition for 24 hours. Afterwards hardness test was done on the sample using Micro Vickers Hardness tester from this experiment, the significant difference in hardness was obtained and the maximum hardness was evaluated from the resin composite sample with 2 mm thickness and 60 seconds light exposure.

  5. A comparative evaluation of fracture resistance of endodontically treated teeth, with variable marginal ridge thicknesses, restored with composite resin and composite resin reinforced with Ribbond: An in vitro study

    Directory of Open Access Journals (Sweden)

    Vaishali Kalburge

    2013-01-01

    Full Text Available Background: The anatomic shape of maxillary premolars show a tendency towards separation of their cusps during mastication after endodontic treatment. Preservation of the marginal ridge of endodontically treated and restored premolars can act as a strengthening factor and improve the fracture resistance. Objectives: To evaluate the effect of varying thickness of marginal ridge on the fracture resistance of endodontically treated maxillary premolars restored with composite and Ribbond reinforced composites. Materials and Methods: One hundred and twenty, freshly extracted, non carious human mature maxillary premolars were selected for this experimental in vitro study. The teeth were randomly assigned in to twelve groups ( n = 10. Group 1 received no preparation. All the premolars in other groups were root canal treated. In subgroups of 3 and 4, DO cavities were prepared while MOD cavities were prepared for all subgroups of group 2, the dimensions of the proximal boxes were kept uniform. In group 3 and 4 the dimensions of the mesial marginal ridge were measured using a digital Vernier caliper as 2 mm, 1.5 mm, 1 mm and 0.5 mm in the respective subgroups. All samples in groups 2.2 and all the subgroups of 3 were restored with a dentin bonding agent and resin composite. The teeth in group 2.3 and all subgroups of 4 were restored with composite reinforced with Ribbond fibers. The premolars were submitted to axial compression up to failure at 45 degree angle to a palatal cusp in universal testing machine. The mean load necessary to fracture was recorded in Newtons and the data was analysed. Results: There was a highly significant difference between mean values of force required to fracture teeth in group 1 and all subgroups of group 2, 3 and 4 (i.e., P < 0.01 Conclusion: On the basis of static loading, preserving the mesial marginal ridge with thicknesses of mm, 1.5 mm, 1 mm and 0.5 mm, composite restored and Ribbond reinforced composite restored

  6. Influence of the stress on magnetoelectric effect in magnetostrictive-PZT bilayers

    Institute of Scientific and Technical Information of China (English)

    DING Jian-ming; ZHONG Chong-gui; JIANG Qing

    2007-01-01

    In this letter,we investigate the influence of the stress on magnetoelectric(ME)effect in a magnetostrictivePZT bilayer.ME voltage coefficient α*E=δE/δH,where δE is the induced electric field for an applied alternating current (ac)magnetic field δH,is obtained by solving the stressrelated piezoelectric constitutive equation and the conventional magnetostrictive equation with appropriate boundary condition.Based on the free-energy density function of the PZT film in stress state,we get the stress-related piezoelectric charge coefficient Pd*31 and dielectric permittivity Pε*33.After taking the cobalt ferrite(CFO)as magnetostrictive phase,it is found that α*E increases with decreasing 2-d compressive stress for CFO-PZT,which not only is qualitatively consistent with previous experimental measurements,but also provides a possible route to improve the ME effect.

  7. Temperature Field Analysis for PZT Pyroelectric Cells for Thermal Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Chi-Yuan Lee

    2011-11-01

    Full Text Available This paper proposes the idea of etching PZT to improve the temperature variation rate of a thicker PZT sheet in order to enhance the energy conversion efficiency when used as pyroelectric cells. A partially covered electrode was proven to display a higher output response than a fully covered electrode did. A mesh top electrode monitored the temperature variation rate and the electrode area. The mesh electrode width affected the distribution of the temperature variation rate in a thinner pyroelectric material. However, a pyroelectric cell with a thicker pyroelectric material was beneficial in generating electricity pyroelectrically. The PZT sheet was further etched to produce deeper cavities and a smaller electrode width to induce lateral temperature gradients on the sidewalls of cavities under homogeneous heat irradiation, enhancing the temperature variation rate.

  8. Wireless Impedance Sensor with PZT-Interface for Prestress-Loss Monitoring in Prestressed Concrete Girder

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Khac Duy; Lee, So Young; Kim, Jeong Tae [Pukyong National University, Busan (Korea, Republic of)

    2011-12-15

    Ensuring the designed prestress force is very important for the safety of prestressed concrete bridge. The loss of prestress force in tendon could significantly reduce load carrying capacity of the structure. In this study, an automated prestress-loss monitoring system for prestressed concrete girder using PZT-interface and wireless impedance sensor node is presented. The following approaches are carried out to achieve the objective. Firstly, wireless impedance sensor nodes are designed for automated impedance-based monitoring technique. The sensor node is mounted on the high-performance Imote2 sensor platform to fulfill high operating speed, low power requirement and large storage memory. Secondly, a smart PZT-interface designed for monitoring prestress force is described. A linear regression model is established to predict prestress-loss. Finally, a system of the PZT-interface interacted with the wireless sensor node is evaluated from a lab-scale tendon-anchorage connection of a prestressed concrete girder.

  9. A PZT Actuated Triple-Finger Gripper for Multi-Target Micromanipulation

    Directory of Open Access Journals (Sweden)

    Tao Chen

    2017-01-01

    Full Text Available This paper presents a triple-finger gripper driven by a piezoceramic (PZT transducer for multi-target micromanipulation. The gripper consists of three fingers assembled on adjustable pedestals with flexible hinges for a large adjustable range. Each finger has a PZT actuator, an amplifying structure, and a changeable end effector. The moving trajectories of single and double fingers were calculated and finite element analyses were performed to verify the reliability of the structures. In the gripping experiment, various end effectors of the fingers such as tungsten probes and fibers were tested, and different micro-objects such as glass hollow spheres and iron spheres with diameters ranging from 10 to 800 μm were picked and released. The output resolution is 145 nm/V, and the driven displacement range of the gripper is 43.4 μm. The PZT actuated triple-finger gripper has superior adaptability, high efficiency, and a low cost.

  10. A Flexible Ultrasound Transducer Array with Micro-Machined Bulk PZT

    Directory of Open Access Journals (Sweden)

    Zhe Wang

    2015-01-01

    Full Text Available This paper proposes a novel flexible piezoelectric micro-machined ultrasound transducer, which is based on PZT and a polyimide substrate. The transducer is made on the polyimide substrate and packaged with medical polydimethylsiloxane. Instead of etching the PZT ceramic, this paper proposes a method of putting diced PZT blocks into holes on the polyimide which are pre-etched. The device works in d31 mode and the electromechanical coupling factor is 22.25%. Its flexibility, good conformal contacting with skin surfaces and proper resonant frequency make the device suitable for heart imaging. The flexible packaging ultrasound transducer also has a good waterproof performance after hundreds of ultrasonic electric tests in water. It is a promising ultrasound transducer and will be an effective supplementary ultrasound imaging method in the practical applications.

  11. Incorporation of piezoelectric Pb(Zr,Ti)O3 fibers into ceramic/polymer composites

    Science.gov (United States)

    Safari, Ahmad; Janas, Victor; Jadidian, Bahram; French, Jonathan D.; Weitz, Gregory E.; Luke, John E.; Cass, Bud

    1996-05-01

    The processing of Pb(Zr,Ti)O3, or PZT, fiber and fiber/polymer composites for transducer applications is discussed. Green PZT fibers, 80 to 100 micrometers in diameter, were formed at Advanced Cerametrics, Inc., using the Viscous Suspension Spinning Process (VSSP). In this process, fine PZT powder is intimately mixed with polymer precursor by high shear mixing. The powder and precursor mixture is spun through a spinneret into a coagulation bath to form fibers. The fibers are washed, dried, and collected on a spool. Yarns containing between 10 and 500 individual fibers were collimated by applying a polymeric sizing to the yarns, and passing the yarns through sizing dies. Yarn bundle tightness and flexibility were controlled by the sizing chemistry. Continuous green yarns were cut to short lengths, or woven in different architectures to create composites with novel microstructures. The short yarns were fired to product PZT straight rods for `pick and place' piezoelectric composites. The woven structures were heat treated and backfilled with polymer to create composites with 1-3, 2-3, and 3-3 connectivity. After heat treatment, the diameter of the individual PZT fibers was 10 to 20 micrometers . Electromechanical characteristics of a number of composites were determined, and will be reported. The PZT VSSP fibers can be used to form fine-scale, large area piezoelectric fiber/polymer composites for use in hydrophones, transducers for medical ultrasonic imaging and non-destructive evaluation, and as sensors and actuators in vibration and noise control.

  12. Multiscale numerical study on ferroelectric nonlinear response of PZT thin films (Conference Presentation)

    Science.gov (United States)

    Wakabayashi, Hiroki; Uetsuji, Yasutomo; Tsuchiya, Kazuyoshi

    2017-06-01

    PZT thin films have excellent performance in deformation precision and response speed, so it is used widely for actuators and sensors of Micro Electro Mechanical System (MEMS). Although PZT thin films outputs large piezoelectricity at morphotropic phase bounfary (MPB), it shows a complicated hysteresis behavior caused by domain switching and structural phase transition between tetragonal and rhombohedral. In general, PZT thin films have some characteristic crystal morphologies. Additionally mechanical strains occur by lattice mismatch with substrate. Therefore it is important for fabrication and performance improvement of PZT thin films to understand the relation between macroscopic hysteresis response and microstructural changes. In this study, a multiscale nonlinear finite element simulation was proposed for PZT thin films at morphotropic phase boundary (MPB) on the substrate. The homogenization theory was employed for scale-bridging between macrostructure and microstructure. Figure 1 shows the proposed multiscale nonlinear simulation [1-3] based on the homogenization theory. Macrostructure is a homogeneous structure to catch the whole behaviors of actuators and sensors. And microstructure is a periodic inhomogeneous structure consisting of domains and grains. Macrostructure and microstructure are connected perfectly by homogenization theory and are analyzed by finite element method. We utilized an incremental form of fundamental constitutive law in consideration with physical property change caused by domain switching and structural phase transition. The developed multiscale finite element method was applied to PZT thin films with lattice mismatch strain on the substrate, and the relation between the macroscopic hysteresis response and microscopic domain switching and structural phase transition were investigated. Especially, we discuss about the effect of crystal morphologies and lattice mismatch strain on hysteresis response.

  13. Magnetoelectric Interactions in Lead-Based and Lead-Free Composites

    Directory of Open Access Journals (Sweden)

    Shashank Priya

    2011-04-01

    Full Text Available Magnetoelectric (ME composites that simultaneously exhibit ferroelectricity and ferromagnetism have recently gained significant attention as evident by the increasing number of publications. These research activities are direct results of the fact that multiferroic magnetoelectrics offer significant technological promise for multiple devices. Appropriate choice of phases with co-firing capability, magnetostriction and piezoelectric coefficient, such as Ni-PZT and NZFO-PZT, has resulted in fabrication of prototype components that promise transition. In this manuscript, we report the properties of Ni-PZT and NZFO-PZT composites in terms of ME voltage coefficients as a function of frequency and magnetic DC bias. In order to overcome the problem of toxicity of lead, we have conducted experiments with Pb-free piezoelectric compositions. Results are presented on the magnetoelectric performance of Ni-NKN, Ni-NBTBT and NZFO-NKN, NZFO-NBTBT systems illustrating their importance as an environmentally friendly alternative.

  14. Structure and electrical properties of PZT/LNO/PT multilayer films on stainless steel substrates

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    PbZr0.53Ti0.47O3 (PZT) ferroelectric thin films were deposited on LaNiO3 (LNO) by sol-gel method. The PbTiO3 (PT) seed layer was depos-ited between the LNO buffer layer and stainless steel (SS) substrate, which effectively decreased the annealing temperature of LNO layer from 750 C to 650 C. X-ray diffraction (XRD) reveals that LNO layers with PT layer crystallize into a perovskite phase on annealing at 650 C for 10 min. PZT deposited on LNO buffer layer with PT seed layer exhibits good ferroelectric proper...

  15. A new submerged split-thickness skin graft technique to rebuild peri-implant keratinized soft tissue in composite flap reconstructed mandible or maxilla.

    Science.gov (United States)

    Fang, Wei; Ma, Wei; Ma, Wei-guang; Li, De-hua; Liu, Bao-lin

    2012-03-01

    The objective of this study was to introduce our preliminary experience on a submerged split-thickness skin graft (STSG) technique combined with secondary vestibuloplasty to rebuild keratinized peri-implant soft tissue and oral vestibule for patients with large oromandibular defects reconstructed by composite flaps. Five patients were enrolled in this study. Stage 1 was submerged STSG and simultaneous implant placement. Stage 2 was the uncovering of the STSG and vestibuloplasty. The implant-borne fixed denture was inserted after this 2-stage treatment. All patients were followed for at least 12 months (average 18 months). Eighteen implants were placed. The rebuilt peri-implant keratinized soft tissue was healthy clinically. The STSG graft had firm adherence to the underlying periosteum. The vestibule had adequate depth to maintain local hygiene. All implants were osseointegrated and all implant-borne prostheses were functioning well. Submerged STSG technique combined with secondary vestibuloplasty may become a feasible and effective solution to rebuild keratinized soft tissue before dental implant restoration. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Thickness and Composition Tailoring of K- and Ka-Band Microwave Absorption of BaCo x Ti x Fe(12-2 x)O19 Ferrites

    Science.gov (United States)

    Narang, Sukhleen Bindra; Pubby, Kunal; Singh, Charanjeet

    2017-02-01

    The goal of this research is to investigate the electromagnetic and microwave absorption properties of M-type barium hexaferrites with chemical formula BaCo x Ti x Fe(12-2 x)O19 ( x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) in K and Ka band. Characterization techniques such as x-ray diffraction analysis and scanning electron microscopy were applied to confirm ferrite formation. The frequency dependence of the complex permittivity and complex permeability was studied for prepared ferrite samples in the frequency range from 18 GHz to 40 GHz. Factors such as the quarter-wavelength condition, impedance matching, high dielectric-magnetic losses, as well as ferromagnetic resonance were investigated to determine their contribution to the absorption characteristics. It was found that the quarter-wavelength ( λ/4) model could be successfully applied to predict and understand the position as well as number of reflection peaks in the microwave absorption spectrum. The origin of the reflection loss peaks is explained and verified based on calculations of input impedance, loss tangent, and ferromagnetic resonance. Reflection loss analysis revealed that all six compositions exhibited reflection loss peaks (absorption >90%) at their matching thicknesses and frequencies. Therefore, these ferrites are potential candidates for use in electromagnetic shielding applications requiring low reflectivity in K and Ka band.

  17. Static and dynamic through thickness lamina properties of thick laminates

    NARCIS (Netherlands)

    Lahuerta, F.; Nijssen, R.P.L.; Van der Meer, F.P.; Sluys, L.J.

    2015-01-01

    Thick laminates are increasingly present in large composites structures such as wind turbine blades. Different factors are suspected to be involved in the decreased static and dynamic performance of thick laminates. These include the effect of self-heating, the scaling effect, and the manufacturing

  18. Energy harvesting using piezoelectric thick films fabricated by a sol-gel process

    Energy Technology Data Exchange (ETDEWEB)

    Shih, J.L. [McGill Univ., Montreal, PQ (Canada). Dept. of Electrical and Computer Engineering; Kobayashi, M.; Moisan, J.F.; Jen, C.K. [National Research Council of Canada, Boucherville, PQ (Canada). Industrial Materials Inst.

    2008-07-01

    Energy harvesting has been touted as a promising technology to power wireless devices. One of the common energies to be harvested is induced by mechanical vibrations. Piezoelectric materials are often used to get such energy. This study focused on a vibration-based energy harvesting device. Very flexible vibrators using lead-zirconate-titanate (PZT) ceramics were needed. Therefore, a sol-gel spray technology was used to fabricate PZT thick film directly onto metal membranes to serve as mechanical vibrators. The sol-gel process is an economical approach with excellent mass production appeal for both unimorph and bimorph sensors. For this study, the density of the PZT film was less than 85 per cent of the bulk PZT. Using a 20 mm diameter unimorph, the voltage generated from a 5 mm deflection displacement was 13.6 volts peak-to-peak at 10 Hz. With a load resistance of 150 K ohms, the measured average power generated by this sensor was estimated to be 41 {mu}W. A vibration test that lasted for 60 days with a frequency of 10 Hz and at a displacement of approximately 1 mm showed that the sensor is both durable and rugged. 14 refs., 7 figs.

  19. 超音速等离子喷涂PZT涂层的结构与性能研究%Structure and performance study of PZT coating prepared by supersonic plasma spraying

    Institute of Scientific and Technical Information of China (English)

    李国禄; 顾林松; 王海斗; 邢志国

    2014-01-01

    Lead-zirconate-titanate (PZT)was important functional materials which were widely used due to their perfect piezoelectric properties.In this paper,coatings were prepared by supersonic plasma spraying,the micro-structure morphology and phase composition of PZT powder and coating were analyzed by SEM,XRD and TEM,as well as making the experiment of the bonding strength,micro hardness and dielectric property on the coating.The results indicated that the coating have a denser structure and low porosity,the surface of the PZT coating was smooth,characteristics of porosity was 1.6%,the average micro hardness reached 562.3 Hv.The dielectric constant of the coating made by the supersonic plasma spraying was about 370 ℃.%锆钛酸铅(PZT)是一种应用广泛具有优良压电性能的功能材料,采用超音速等离子喷涂的方法在45#钢基体表面制备了PZT陶瓷涂层,采用 X射线衍射(XRD)对烧结粉末和 PZT 涂层相组成进行了检测,利用场发射扫描电子显微镜(SEM)对粉末和喷涂层形貌进行了观察,利用 TEM透射电子显微镜对涂层的微观结构进行了分析,并对涂层的显微硬度以及介电性能进行了测试.结果表明,超音速等离子喷涂制备的 PZT 涂层表面平整,结构致密,孔隙率为1.6%,平均显微硬度为562.3 Hv,居里温度为370℃.

  20. Piezoelectric Resonance Investigation of Zr-rich PZT at Room Temperature

    NARCIS (Netherlands)

    Cereceda, N.; Noheda, B.; Fernandez-del-Castillo, J.R.; Gonzalo, J.A.; Frutos, J. De

    1999-01-01

    We study the piezoelectric resonances in poled PZT ceramics by means of a microscopic model. It connects the microscopic vibrations of the ionic units, cooperatively producing the piezoelectric effect, with the macroscopic piezoelectric parameters. The behaviour at the resonance is well described in

  1. Optimization of the low-temperature MOCVD process for PZT thin films

    CERN Document Server

    Wang, C H; Choi, D J

    2000-01-01

    Pb(Zr sub X Ti sub 1 sub - sub X)O sub 3 (PZT) thin films of about 0.34 nm were successfully grown at a low temperature of 500 .deg. C by metalorganic chemical vapor deposition with a beta-diketonate complex of Pb(tmhd) sub 2 , zirconium t-butoxide, and titanium isopropoxide as source precursors. Ferroelectric capacitors of a Pt/PZT/Pt configuration were fabricated, and their structural and electrical properties were investigated as a function of the input Pb/(Zr+Ti) and Zr/(Zr+Ti) source ratios. The structure of the as-grown films at 500 .deg. C changed from tetragonal to pseudocubic with increasing the Zr/(Zr+Ti) ratio above an input Pb/(Zr+Ti) source ratio of 5.0 while a 2nd phase of ZrO sub 2 was only observed below Pb/(Zr+Ti) ratio of 5.0, regardless of the Zr/(Zr+Ti) ratio. The dielectric constant and loss of the PZT films were 150-1200 and 0.01-0.04 at 100 kHz, respectively, Leakage current densities decreased with increasing the Zr/(Zr+Ti) ratio. The process window for growing a single phase PZT is ve...

  2. In-situ structural investigations of ferroelasticity in soft and hard rhombohedral and tetragonal PZT

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Maxim I., E-mail: maximm@alumni.ntnu.no; Einarsrud, Mari-Ann; Tolchard, Julian R.; Grande, Tor [Department of Materials Science and Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway); Geiger, Philipp T.; Webber, Kyle G. [Department of Materials Science, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen (Germany); Damjanovic, Dragan [Ceramics Laboratory, Swiss Federal Institute of Technology in Lausanne-EPFL, 1015 Lausanne (Switzerland)

    2015-10-28

    Despite the technological importance of hard and soft PZT, Pb(Zr,Ti)O{sub 3}, ceramics, the mechanisms of ferroelectric hardening and softening remain widely discussed in the literature. The hardening and softening phenomena have traditionally been investigated in relation with dielectric manifestations such as aging of the dielectric susceptibility and constriction of the polarization-electric field hysteresis loop. Here, we present a systematic investigation of the ferroelectric and ferroelastic properties of soft and hard PZT in both the tetragonal and rhombohedral phases. A particular focus has been devoted to ferroelastic domain switching by characterizing the macroscopic mechanical constitutive behavior and in-situ synchrotron X-ray diffraction during compression. It is demonstrated that variation of the ordering state of point defects in PZT ceramics affects the switching behavior of both ferroelectric and ferroelastic domains under mechanical or electrical fields. Softening of the mechanical and electrical properties of originally hard PZT ceramics was conferred by quenching the materials from above the Curie temperature. The present findings are discussed with respect to the current understanding of hardening-softening transitions in ferroelectric materials.

  3. Parametric study on a collocated PZT beam vibration absorber and power harvester

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shyh Chin [Mechanical Engineering, Ming Chi University of Technology, New Taipei (China); Tsai, Chao Yang [Mechanical Engineering Army Academy, R.O.C., Taoyuan (China); Liao, Hsiao Hui [LNG Construction and Project Division, CPC Corp., Taipei (China)

    2016-11-15

    The parametric effects of a PZT beam that is simultaneously used as a vibration absorber and a power harvester were investigated in this study. A cantilever beam paved with PZT layers and with added tip mass has been widely used as a harvester or sometimes as a Dynamic vibration absorber (DVA). However, the beam is rarely considered a collocated device. In this study, the first step was theoretical derivation of a distributed beam covered with bimorph PZT layers. Then, the beam was attached to a 1DOF vibratory main system. Two indicators for vibration absorption and power harvesting were defined. Numerical results demonstrated that the lumped mass ratio favored both of the abilities, but that the DVA mass ratio influenced these two abilities in exactly the opposite way. The conjunction of a harvester circuit into a DVA shifted its resonance frequency up to 5 % (an extreme case of open circuit R→∞). Simultaneous power harvesting diminished the absorption capability up to 35 % for each set of mass ratios. To achieve the maximum degree of power harvesting, a corresponding load resistance that somewhat increases with the lumped mass ratio is applied. Experimental results verified the existence of the best load resistance, but the measured harvested curve was lower than the theoretical calculation because of structure damping and deviations of PZT material properties.

  4. Ferroelectric and piezoelectric properties of epitaxial PZT films and devices on silicon

    NARCIS (Netherlands)

    Nguyen, Minh Duc

    2010-01-01

    In this thesis, the integration of lead zirconate titanate Pb(Zr,Ti)O3 (PZT) thin films into piezoelectric microelectromechanical systems (MEMS) based on silicon is studied. In these structures, all epitaxial oxide layers (thin film/electrode/buffer-layer(s)) were deposited by pulsed laser depositio

  5. Enhancement of ferroelectric and piezoelectric properties in PZT thin films with heterolayered structure

    NARCIS (Netherlands)

    Nguyen, D.M.; Nguyen, Chi T.Q.; Trinh, Thong Q.; Nguyen, Tai; Pham, Thao N.; Rijnders, A.J.H.M.; Vu, Hung N.

    2013-01-01

    This paper reports the latest experimental results of multilayered, heterolayered, and alternating heterolayered PZT thin films obtained by spin coating on Pt/Ti/SiO2/Si wafers using Zr-rich (P60) and Ti-rich (P40) solutions which were prepared by sol–gel route process. The ferroelectric and piezoel

  6. Ferroelectric and piezoelectric properties of epitaxial PZT films and devices on silicon

    NARCIS (Netherlands)

    Nguyen, Duc Minh

    2010-01-01

    In this thesis, the integration of lead zirconate titanate Pb(Zr,Ti)O3 (PZT) thin films into piezoelectric microelectromechanical systems (MEMS) based on silicon is studied. In these structures, all epitaxial oxide layers (thin film/electrode/buffer-layer(s)) were deposited by pulsed laser depositio

  7. Development of the new shape PZT ceramics sounder suitable for a sound source of artificial larynx

    Science.gov (United States)

    Ooe, Katsutoshi; Kanetake, Ryota; Sugio, Yuuichi; Tanaka, Akimitsu

    2007-12-01

    Various speech production substitutes, which aim to reconstruct speech functions, have been developed and used practically by speech impaired individuals. However, conventional speech production substitutes have various drawbacks; therefore, perfect speech production substitutes are expected to be developed. We focused on the PZT ceramics sounder as a sound source in an electric drive artificial larynx. We first developed the artificial larynx that uses a PZT ceramic sounder and then evaluated its performance. The vocalized sound of the artificial larynx user shows good characteristics at the formant frequency, which is important for vowel discrimination. The characteristic feature of our artificial larynx is its individual structure, and this typical structure implies that the sound source and the implant are separated. This structure facilitates a high biocompatibility in our artificial larynx. In our previous work, the improvement in the acoustic characteristics of the sound source was described. The improvement is achieved by the optimization of the electric control and its structure. In this paper, we present the results of shape optimization and new shape PZT ceramics sounder evaluation. The optimized shape is decided on FEM analysis, and prototype PZT ceramics sounder based on above analysis is manufactured by way of trial. Additionally, the performance of prototype sounder is evaluated by acoustic analysis. Until now, we have researched about the immobilization of biomolecules onto the metal surface. It is believed that biomolecular immobilization on the sound source surface improves its biocompatibility. In the future, we aim to realize implantable sound sources that employ biomolecular immobilization technology.

  8. Effects of Pt diffusion barrier layer on the interface reaction and electric properties of PZT film/Si ( 111 ) sample

    Institute of Scientific and Technical Information of China (English)

    ZHU, Yong-Fa(朱永法); CAO, Li-Li(曹立礼); YAN, Pei-Yu(阎培渝); LI, Long-Tu(李龙土); YI, Tao(易涛)

    2000-01-01

    The effects of the Pt diffusion barrier layer on the interface diffusion and reaction, crystallization, dielectric and ferroelectric properties of the PZT/Si(111) sample have been studied using XPS, AES and XRD techniques. The results indicate that the Pt diffusion barrier layer between the PZT layer and the Si substrate prohibits the formation of TiCx, TiSix and SiO2 species in the PZT layer. The Pt barrier layer also completely interrupts the diffusion of Si from the Si substrate into the PZT layer and impedes the diffusion of oxygen from air to the Si substrate greatly. Although the Pt layer can not prevent completely the diffusion and reaction between oxygen and silicon, it can prevent the formation of a stable SiO2 interface layer on the interface of PZT/Si. The Pt layer reacts with silicon to form PtSix species on the interface of Pt/Si, which can intensify the chemical binding strength between the Pt layer and the Si substrate. To play a good role as a diffusion barrier layer, the Pt barrier layer must be not thinner than 140 nm. The existence of the Pt layer not only promotes the crystallization of PZT layer to form a perovskite phase but also improves dielectric and ferroelectric performances of the PZT layer.

  9. Progress in Dual (Piezoelectric-Magnetostrictive Phase Magnetoelectric Sintered Composites

    Directory of Open Access Journals (Sweden)

    Rashed Adnan Islam

    2012-01-01

    Full Text Available The primary aims of this review article are (a to develop the fundamental understanding of ME behavior in perovskite piezoelectric-spinel magnetostrictive composite systems, (b to identify the role of composition, microstructural variables, phase transformations, composite geometry, and postsintering heat treatment on ME coefficient, and (c to synthesize, characterize, and utilize the high ME coefficient composite. The desired range of ME coefficient in the sintered composite is 0.5–1 V/cm⋅Oe. The studies showed that the soft piezoelectric phase quantified by smaller elastic modulus, large grain size of piezoelectric phase (~1 μm, and layered structures yields higher magnitude of ME coefficient. It is also found that postsintering thermal treatment such as annealing and aging alters the magnitude of magnetization providing an increase in the magnitude of ME coefficient. A trilayer composite was synthesized using pressure-assisted sintering with soft phase [0.9 PZT–0.1 PZN] having grain size larger than 1 μm and soft ferromagnetic phase of composition Ni0.8Cu0.2Zn0.2Fe2O4 [NCZF]. The composite showed a high ME coefficient of 412 and 494 mV/cm⋅Oe after sintering and annealing, respectively. Optimized ferrite to PZT thickness ratio was found to be 5.33, providing ME coefficient of 525 mV/cm⋅Oe. The ME coefficient exhibited orientation dependence with respect to applied magnetic field. Multilayering the PZT layer increased the magnitude of ME coefficient to 782 mV/cm⋅Oe. Piezoelectric grain texturing and nanoparticulate assembly techniques were incorporated with the layered geometry. It was found that with moderate texturing, d33 and ME coefficient reached up to 325 pC/N and 878 mV/cm⋅Oe, respectively. Nanoparticulate core shell assembly shows the promise for achieving large ME coefficient in the sintered composites. A systematic relationship between composition, microstructure, geometry, and properties is

  10. Resonant magnetoelectric response of composite cantilevers: Theory of short vs. open circuit operation and layer sequence effects

    Directory of Open Access Journals (Sweden)

    Matthias C. Krantz

    2015-11-01

    Full Text Available The magnetoelectric effect in layered composite cantilevers consisting of strain coupled layers of magnetostrictive (MS, piezoelectric (PE, and substrate materials is investigated for magnetic field excitation at bending resonance. Analytic theories are derived for the transverse magnetoelectric (ME response in short and open circuit operation for three different layer sequences and results presented and discussed for the FeCoBSi-AlN-Si and the FeCoBSi-PZT-Si composite systems. Response optimized PE-MS layer thickness ratios are found to greatly change with operation mode shifting from near equal MS and PE layer thicknesses in the open circuit mode to near vanishing PE layer thicknesses in short circuit operation for all layer sequences. In addition the substrate layer thickness is found to differently affect the open and short circuit ME response producing shifts and reversal between ME response maxima depending on layer sequence. The observed rich ME response behavior for different layer thicknesses, sequences, operating modes, and PE materials can be explained by common neutral plane effects and different elastic compliance effects in short and open circuit operation.

  11. Experimental and Theoretical Investigations of the Impact Localization of a Passive Smart Composite Plate Fabricated Using Piezoelectric Materials

    Directory of Open Access Journals (Sweden)

    M. M. S. Dezfouli

    2013-01-01

    Full Text Available Two passive smart composite plates are fabricated using one and two PZT patches that are cheaper than the PZT wafer. The composite plate is fabricated in low temperature through the hand lay-up method to avoid PZT patch decoupling and wire spoiling. The locus of the impact point is identified using the output voltage to identify the impact location using one sensor. The output voltages of the sensors are analyzed to identify the impact location using two sensors. The locations of the impacts are determined based on the crossing points of two circles and the origin of an intended Cartesian coordinate system that is concentric with one of the sensors. This study proposes the impact location identification of the passive smart composite using the low-cost PZT patch PIC155 instead of common embedded materials (wafer and element piezoelectric.

  12. Chem-Prep PZT 95/5 for neutron generator applications : development of laboratory-scale powder processing operations.

    Energy Technology Data Exchange (ETDEWEB)

    Montoya, Ted V.; Moore, Roger Howard; Spindle, Thomas Lewis Jr.

    2003-12-01

    Chemical synthesis methods are being developed as a future source of PZT 95/5 powder for neutron generator voltage bar applications. Laboratory-scale powder processes were established to produce PZT billets from these powders. The interactions between calcining temperature, sintering temperature, and pore former content were studied to identify the conditions necessary to produce PZT billets of the desired density and grain size. Several binder systems and pressing aids were evaluated for producing uniform sintered billets with low open porosity. The development of these processes supported the powder synthesis efforts and enabled comparisons between different chem-prep routes.

  13. Effect of Ni/Nb on structure, electrical and ferroelectric properties of 0.5PNN-0.5PZT ceramics

    Directory of Open Access Journals (Sweden)

    Rashmi Gupta

    2015-03-01

    Full Text Available The solid solutions of lead nickel niobate (PNN and lead zirconate titanate (PZT, with general formula 0.5 Pb(NixNb1-xO3-0.5 PZT, where x = 1/3, 1/2 and 2/3 and Zr/Ti = 50/50, were prepared by conventional solid state reaction technique. The perovskite phase formation and morphology were examined by powder X-ray diffraction (XRD and scanning electron microscopy (SEM techniques. From microstructure investigations, the grain size was found to lie in the range of 0.2–1.1 µm. Diffuse phase transition and dielectric relaxation was obtained for all three compositions. The nature of dielectric relaxation was investigated through complex plane Argand plot or Cole-Cole plot. It was found that both grains as well as grain boundary contribute to dielectric relaxation. A direct correlation between the grain size and electrical properties was obtained. The remnant polarization and grain size were found to follow the inverse relationship. The inverse relationship between remnant polarization and grain size was established.

  14. Electroactive properties of flexible piezoelectric composites

    Directory of Open Access Journals (Sweden)

    Walter Katsumi Sakamoto

    2001-07-01

    Full Text Available A flexible piezoelectric composite with 0-3 connectivity, made from Lead Zirconate Titanate (PZT powder and vegetable-based polyurethane (PU, was doped with small amount of semiconductor powder. As a result a composite with 0-0-3 connectivity was obtained. The nature of absorption and steady state electrical conduction and the dielectric behaviour have been studied for this ceramic/polymer composite. The dielectric loss processes of the composite were observed to be dominated by those the polymer. Adding a semiconductor phase in the composite the electrical conductivity can be controlled and a continuous electric flux path could be created between the PZT grains. This composite may be poled at low voltage and in shorter time compared with composites without a conductive phase.

  15. Characteristic analysis of diaphragm-type transducer that is thick relative to its size

    Science.gov (United States)

    Ishiguro, Yuya; Zhu, Jing; Tagawa, Norio; Okubo, Tsuyoshi; Okubo, Kan

    2017-07-01

    In recent years, high-performance piezoelectric micromachined ultrasonic transducers (PMUTs) have been fabricated by micro electro mechanical systems (MEMS) technology. For high-resolution imaging, it is important to broaden the frequency bandwidth. By reducing the diaphragm size to increase the resonance frequency, the film thickness becomes relatively larger and hence the transmitting and receiving characteristics may different from those of a usual thin diaphragm. In this study, we examine the performance of a square-diaphragm-type lead zirconate titanate (PZT) transducer through simulations. To realize the desired resonance frequency of 20 MHz, firstly, the diaphragm size and the thickness of the layers of PZT and Si constituting a PMUT are examined, and then, three PZT/Si models with different thicknesses are selected. Subsequently, using the models, we analyze the transmitting efficiency, transmitting bandwidth, receiving sensitivity (piezoelectric voltage/electric charge), and receiving bandwidth using an FEM simulator. It is found that the proposed models can transmit ultrasound independently of the diaphragm vibration and have wide bandwidth of the receiving frequency as compared with that of a typical PMUT.

  16. Post-impact fatigue of cross-plied, through-the-thickness reinforced carbon/epoxy composites. M.S. Thesis - Clemson Univ.

    Science.gov (United States)

    Serdinak, Thomas E.

    1994-01-01

    An experimental investigation of the post-impact fatigue response of integrally woven carbon/epoxy composites was conducted. Five different through-the-thickness (TTT) reinforcing fibers were used in an experimental textile process that produced an integrally woven (0/90/0/90/0/90/0/90/0)(sub T) ply layup with 21K AS4 carbon tow fiber. The resin was Hercules 3501-6, and the five TTT reinforcing fibers were Kevlar, Toray carbon, AS4 carbon, glass, and IM6 carbon. The purpose of this investigation was to study the post-impact fatigue response of these material systems and to identify the optimum TTT fiber. Samples were impacted with one half inch diameter aluminum balls with an average velocity of 543 ft/sec. Post-impact static compression and constant amplitude tension-compression fatigue tests were conducted. Fatigue tests were conducted with a loading ratio of R=-5, and frequency of 4 Hz. Damage growth was monitored using x-radiographic and sectioning techniques and by examining the stress-strain response (across the impact site) throughout the fatigue tests. The static compressive stress versus far-field strain response was nearly linear for all material groups. All the samples had a transverse shear failure mode. The average compressive modulus (from far-field strain) was about 10 Msi. The average post-impact static compressive strength was about 35.5 Ksi. The IM6 carbon sample had a strength of over 40 Ksi, more than 16 percent stronger than average. There was considerable scatter in the S-N data. However, the IM6 carbon samples clearly had the best fatigue response. The response of the other materials, while worse than IM6 carbon, could not be ranked definitively. The initial damage zones caused by the impact loading and damage growth from fatigue loading were similar for all five TTT reinforcing materials. The initial damage zones were circular and consisted of delaminations, matrix cracks and ply cracks. Post-impact fatigue loading caused delamination growth

  17. Design, Modeling and Optimization of a Piezoelectric Pressure Sensor based on a Thin-Film PZT Membrane Containing Nanocrystalline Powders

    National Research Council Canada - National Science Library

    Vahid Mohammadi; Mohammad Hossein Sheikhi

    2009-01-01

    ...^ thin film has been presented and then a pressure sensor based on multilayer thin-film PZT diaphragm contain of Lead Zirconate Titanate nanocrystalline powders was designed, modeled and optimized...

  18. A hybrid phenomenological model for ferroelectroelastic ceramics. Part II: Morphotropic PZT ceramics

    Science.gov (United States)

    Stark, S.; Neumeister, P.; Balke, H.

    2016-10-01

    In this part II of a two part series, the rate-independent hybrid phenomenological constitutive model introduced in part I is modified to account for the material behavior of morphotropic lead zirconate titanate ceramics (PZT ceramics). The modifications are based on a discussion of the available literature results regarding the micro-structure of these materials. In particular, a monoclinic phase and a highly simplified representation of the hierarchical structure of micro-domains and nano-domains observed experimentally are incorporated into the model. It is shown that experimental data for the commercially available morphotropic PZT material PIC151 (PI Ceramic GmbH, Lederhose, Germany) can be reproduced and predicted based on the modified hybrid model.

  19. Fluid Vessel Quantity Using Non-invasive PZT Technology Flight Volume Measurements Under Zero G Analysis

    Science.gov (United States)

    Garofalo, Anthony A

    2013-01-01

    The purpose of the project is to perform analysis of data using the Systems Engineering Educational Discovery (SEED) program data from 2011 and 2012 Fluid Vessel Quantity using Non-Invasive PZT Technology flight volume measurements under Zero G conditions (parabolic Plane flight data). Also experimental planning and lab work for future sub-orbital experiments to use the NASA PZT technology for fluid volume measurement. Along with conducting data analysis of flight data, I also did a variety of other tasks. I provided the lab with detailed technical drawings, experimented with 3d printers, made changes to the liquid nitrogen skid schematics, and learned how to weld. I also programmed microcontrollers to interact with various sensors and helped with other things going on around the lab.

  20. Dielectric response of capacitor structures based on PZT annealed at different temperatures

    Science.gov (United States)

    Kamenshchikov, Mikhail V.; Solnyshkin, Alexander V.; Pronin, Igor P.

    2016-12-01

    Dielectric response of thin-film capacitor structures of Pt/PZT/Pt deposited by the RF magnetron sputtering method and annealed at temperatures of 540-570 °C was investigated. It was found that dielectric properties of these structures depend on the synthesis temperature. Stability of a polarized state is considered on the basis of the analysis of hysteresis loops and capacitance-voltage (C-V) characteristics. The contribution of the domain mechanism in the dielectric response of the capacitor structure comprising a ferroelectric is discussed. Extreme dependences of electrophysical characteristics of PZT films on their synthesis temperature were observed. Correlation of dielectric properties with microstructure of these films is found out.

  1. Characterization and comparison of PZT powder synthesis by solid state and sol gel methods

    Directory of Open Access Journals (Sweden)

    E Pakizeh

    2012-09-01

    Full Text Available   This paper describes the synthesis of Pb(Zr0.95Ti0.05O3 powder by sol gel and solid state methods. PZT powders were fabricated by solid-state reaction process using metal oxides and in sol gel method salts and organic compounds were employed. The powders were calcined at 700 and 950 oC in sol gel and solid state methods, respectively. The synthesized powders were analyzed by FTIR and XRD. The average crystal grain size of PZT powders determined by X-ray diffraction method using the Scherrer equation, and in sol gel and solid state methods measured 42 and 330 nm, respectively. The optical constants of powders were evaluated and compaed using FTIR transmittance spectroscopy and Kramers-Kronig analysis.

  2. Effect of electric field, stress and environment on delayed fracture of a PZT-5 ferroelectric ceramic

    Institute of Scientific and Technical Information of China (English)

    WANG; Yi; SU; Yanjing; CHU; Wuyang; QIAO; Lijie

    2005-01-01

    The combined effect of electric and mechanical loading on fracture of a PZT-5 ferroelectric ceramic in silicone oil has been investigated using a single edge notched specimen. The results show that the fracture toughness and the threshold stress intensity factor of delayed fracture in silicone oil, i.e. stress corrosion cracking, decrease linearly with the increasing applied electric field, either positive or negative. For the PZT-5 ferroelectric ceramics, delayed fracture in silicone oil under sustained positive or negative field can occur, and the threshold field for delayed fracture under sustained positive or negative field decreases linearly with applied stress intensity factor. The combined effect of electric and mechanical loading on delayed fracture in silicone oil includes fieldenhancing delayed fracture under sustained load and stress-enhancing delayed fracture in silicone oil under sustained field.

  3. Fluid Vessel Quantity using Non-Invasive PZT Technology Flight Volume Measurements Under Zero G Analysis

    Science.gov (United States)

    Garofalo, Anthony A.

    2013-01-01

    The purpose of the project is to perform analysis of data using the Systems Engineering Educational Discovery (SEED) program data from 2011 and 2012 Fluid Vessel Quantity using Non-Invasive PZT Technology flight volume measurements under Zero G conditions (parabolic Plane flight data). Also experimental planning and lab work for future sub-orbital experiments to use the NASA PZT technology for fluid volume measurement. Along with conducting data analysis of flight data, I also did a variety of other tasks. I provided the lab with detailed technical drawings, experimented with 3d printers, made changes to the liquid nitrogen skid schematics, and learned how to weld. I also programmed microcontrollers to interact with various sensors and helped with other things going on around the lab.

  4. Microstructure and Electromechanical Properties in PMnN-PZT Ceramics Sintered at Different Temperatures

    Institute of Scientific and Technical Information of China (English)

    Baoshan LI; Zhigang ZHU; Guorong LI; Aili DING

    2005-01-01

    The microstructure and piezoelectric properties of Pb[(Zr0.52Ti0.48)0.95(Mn1/3Nb2/3)0.05]O3 (PMnN-PZT) ceramics have been investigated at different sintering temperatures from 1070℃ to 1280℃. The experimental results suggest that grain sizes and electromechanical properties of the ceramics show strong sintering temperature dependences.Double polarization to electric field (P-E) loops of the PMnN-PZT ceramics are assumed to be the result of the pinning effect of the defect dipoles. The results obtained through X-ray photoelectron spectrum suggest that sintering temperature affects valence of the Mn ion and quantity of oxygen vacancies. Hence, a proper explanation is proposed to illustrate the fluctuation of mechanical quality factor (Qm) due to the sintering temperature.

  5. Electrodynamic properties of porous PZT-Pt films at terahertz frequency range

    Energy Technology Data Exchange (ETDEWEB)

    Komandin, Gennady A.; Porodinkov, Oleg E.; Spektor, Igor E.; Volkov, Alexander A. [Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Vorotilov, Konstantin A.; Seregin, Dmitry S.; Sigov, Alexander S. [Moscow Technological University (MIREA), Moscow (Russian Federation)

    2017-01-15

    Electrodynamics of Si-SiO{sub 2}-TiO{sub 2}-Pt-PZT heterostructures is studied in the frequency range from 5 to 5000 cm{sup -1} by monochromatic BWO (backward wave oscillator) and infrared Fourier-transform spectroscopy techniques to derive the dielectric characteristics of the sol-gel porous ferroelectric PbZr{sub 0.48}Ti{sub 0.52}O{sub 3} films. Broad frequency band dielectric response of PZT films with different density is constructed using the oscillator dispersion models. The main contribution to the film permittivity is found to form at frequencies below 100 cm{sup -1} depending strongly and non-linearly on the film medium density. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Optical absorption dependence on composition and thickness of In{sub x}Ga{sub 1-x}N (0.05 < Multiplication-Sign < 0.22) grown on GaN/sapphire

    Energy Technology Data Exchange (ETDEWEB)

    Jampana, Balakrishnam R., E-mail: balu@udel.edu [Material Science and Engineering, University of Delaware, Newark, DE 19716 (United States); Weiland, Conan R.; Opila, Robert L. [Material Science and Engineering, University of Delaware, Newark, DE 19716 (United States); Ferguson, Ian T. [Dept. of Electrical and Computer Engineering, University of North Carolina, Charlotte, NC 28223 (United States); Honsberg, Christiana B. [School of Electrical, Computer, and Energy Engineering, Arizona State University, Tempe, AZ 85287 (United States)

    2012-09-01

    We report the change in optical absorption properties of InGaN epilayers around the critical layer thickness determined from X-ray diffraction. Detrimental sub-band gap absorption is observed in InGaN thin films grown beyond the critical layer thicknesses, and is caused by localized electric fields around extended crystalline defects and aided by V-defects through light channeling. The photoluminescence response from InGaN thin films, grown beyond the critical layer thickness, is reduced owing to absorption of the incident laser light by non-radiative recombination extended crystalline defects. The formation of V-defects is observed to occur beyond the critical layer thickness and continues to grow in areal coverage aiding in sub-band gap absorption. This optical behavior sets constraints to be incorporated in the design of InGaN solar cell and requirement for improvement in epitaxial growth techniques to reduce V-defects. - Highlights: Black-Right-Pointing-Pointer We studied the change in optical absorption of InGaN epilayer with thickness. Black-Right-Pointing-Pointer Critical thickness for the optical absorption changes determined by X-ray diffraction. Black-Right-Pointing-Pointer The critical thickness reduced with increasing InGaN composition. Black-Right-Pointing-Pointer The change in optical absorption is attributed to the creation of V-defects in InGaN. Black-Right-Pointing-Pointer The creation of V-defects reduces the photoluminescence intensity of InGaN.

  7. Finite Element Analysis of Single Cell Stiffness Measurements Using PZT-Integrated Buckling Nanoneedles

    Directory of Open Access Journals (Sweden)

    Maryam Alsadat Rad

    2016-12-01

    Full Text Available This paper proposes a new technique for real-time single cell stiffness measurement using lead zirconate titanate (PZT-integrated buckling nanoneedles. The PZT and the buckling part of the nanoneedle have been modelled and validated using the ABAQUS software. The two parts are integrated together to function as a single unit. After calibration, the stiffness, Young’s modulus, Poisson’s ratio and sensitivity of the PZT-integrated buckling nanoneedle have been determined to be 0.7100 N·m−1, 123.4700 GPa, 0.3000 and 0.0693 V·m·N−1, respectively. Three Saccharomyces cerevisiae cells have been modelled and validated based on compression tests. The average global stiffness and Young’s modulus of the cells are determined to be 10.8867 ± 0.0094 N·m−1 and 110.7033 ± 0.0081 MPa, respectively. The nanoneedle and the cell have been assembled to measure the local stiffness of the single Saccharomyces cerevisiae cells The local stiffness, Young’s modulus and PZT output voltage of the three different size Saccharomyces cerevisiae have been determined at different environmental conditions. We investigated that, at low temperature the stiffness value is low to adapt to the change in the environmental condition. As a result, Saccharomyces cerevisiae becomes vulnerable to viral and bacterial attacks. Therefore, the proposed technique will serve as a quick and accurate process to diagnose diseases at early stage in a cell for effective treatment.

  8. The study of dielectric, pyroelectric and piezoelectric properties on hot pressed PZT-PMN systems

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Geetika; Umarji, A. M. [Materials Research Centre, Indian Institute of Science, Bangalore-560 012 (India); Maglione, Mario [ICMCB, Universite de Bordeaux,-CNRS, 87, Av Dr Schweitzer 33806 Pessac (France)

    2012-12-15

    Hot uniaxial pressing technique has been adopted for the densification of PZT-PMN system with an aim to yield dense ceramics and to lower the sintering temperature and time for achieving better and reproducible electronic properties. The ceramics having >97% theoretical density and micron size grains are investigated for their dielectric, pyroelectric and piezoelectric properties. The effect of Li and Mn addition has also been studied.

  9. The study of dielectric, pyroelectric and piezoelectric properties on hot pressed PZT-PMN systems

    Directory of Open Access Journals (Sweden)

    Geetika Srivastava

    2012-12-01

    Full Text Available Hot uniaxial pressing technique has been adopted for the densification of PZT-PMN system with an aim to yield dense ceramics and to lower the sintering temperature and time for achieving better and reproducible electronic properties. The ceramics having >97% theoretical density and micron size grains are investigated for their dielectric, pyroelectric and piezoelectric properties. The effect of Li and Mn addition has also been studied.

  10. Improvement of the fatigue and the ferroelectric properties of PZT films through a LSCO seed layer

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Sofia A.S., E-mail: sofiarodrigues@fisica.uminho.pt; Silva, José P.B.; Khodorov, Anatoli; Martín-Sánchez, Javier; Pereira, M.; Gomes, M.J.M.

    2013-11-01

    Highlights: • Pulsed laser deposited PZT thin films. • Seed layer effect on the structural and ferroelectric properties of the PZT films. • The stability of P{sub r} was improved with the introduction of the LSCO layer. -- Abstract: The ability to optimizate the preparation of Lead Zirconate Titanate (PZT) films on platinized Si substrate by pulsed laser deposition was demonstrated. The effect of the modification of the interface film/electrode through the use of a (La,Sr)CoO{sub 3} (LSCO) seed layer on the remnant polarization, fatigue endurance and stress in PZT films was studied. An improvement on the ferroelectric properties was found with the using of the LSCO layer. A remnant polarization (P{sub r}) of 19.8 μC/cm{sup 2} and 4.4 μC/cm{sup 2} for films with and without the LSCO layer were found. In the same way the polarization fatigue decreases significantly after deposition of the LSCO layer between the film and substrate. Atomic force microscopy (AFM) images revealed a different growth process in the films. Current–voltage (I–V) measurements showed that the use of LSCO seed layer improves the leakage current and, on the other hand the conduction mechanisms in the film without LSCO, after the fatigue test, was found to be changed from Schottky to Poole–Frenkel. The trap activation energy (about 0.14 eV) determined from Poole–Frenkel mode agrees well with the energy level of oxygen vacancies. The films stresses were estimated by XRD in order to explain the improvement on the structure and consequentially ferroelectric properties of the films. The model proposed by Dawber and Scott was found to be in agreement with our experimental data, which seems to predict that the oxygen vacancies play an important role on fatigue.

  11. Lithographic definition of channel and void structures in multilayer PZT microactuators

    Science.gov (United States)

    Rosqvist, Tobias; Johansson, Stefan A. I.

    1999-10-01

    We are investigating techniques to fabricate advanced microactuators cost efficiently and in particular to combine silicon microstructures with multilayer PZT microelements. Aiming at an increased freedom in design of multilayer PZT elements, various process steps to build channel and void structures in the actuator body are investigated. In a multilayer actuator, channels and voids can be used for transportation of fluids or to change transducer properties. A PZT green ceramic body is built with internal sacrificial structures defined using photolithography and patterned polymer foil and these structures are removed during binder burnout. In difference to conventional green tape lamination the technique used in the presented experiments, wet building, tends to planarize consecutive layers cast. This is particularly advantageous for high aspect ratio sacrificial structures. Results show that possible channel dimensions range from 10 micrometers up to above 200 micrometers . The lower channel dimension limitation is determined by the surface roughness of a cast green layer and the grain growth during sintering. No sagging of the channels is observed at the investigated channel dimensions. The mechanical and chemical stability of the sacrificial material during exposure to solvent and moderate heat is found to be important. The large scale manufacturing aspect of the investigated technique is also discussed.

  12. The Effect of Acceptor and Donor Doping on Oxygen Vacancy Concentrations in Lead Zirconate Titanate (PZT

    Directory of Open Access Journals (Sweden)

    Christoph Slouka

    2016-11-01

    Full Text Available The different properties of acceptor-doped (hard and donor-doped (soft lead zirconate titanate (PZT ceramics are often attributed to different amounts of oxygen vacancies introduced by the dopant. Acceptor doping is believed to cause high oxygen vacancy concentrations, while donors are expected to strongly suppress their amount. In this study, La3+ donor-doped, Fe3+ acceptor-doped and La3+/Fe3+-co-doped PZT samples were investigated by oxygen tracer exchange and electrochemical impedance spectroscopy in order to analyse the effect of doping on oxygen vacancy concentrations. Relative changes in the tracer diffusion coefficients for different doping and quantitative relations between defect concentrations allowed estimates of oxygen vacancy concentrations. Donor doping does not completely suppress the formation of oxygen vacancies; rather, it concentrates them in the grain boundary region. Acceptor doping enhances the amount of oxygen vacancies but estimates suggest that bulk concentrations are still in the ppm range, even for 1% acceptor doping. Trapped holes might thus considerably contribute to the charge balancing of the acceptor dopants. This could also be of relevance in understanding the properties of hard and soft PZT.

  13. The Effect of Acceptor and Donor Doping on Oxygen Vacancy Concentrations in Lead Zirconate Titanate (PZT)

    Science.gov (United States)

    Slouka, Christoph; Kainz, Theresa; Navickas, Edvinas; Walch, Gregor; Hutter, Herbert; Reichmann, Klaus; Fleig, Jürgen

    2016-01-01

    The different properties of acceptor-doped (hard) and donor-doped (soft) lead zirconate titanate (PZT) ceramics are often attributed to different amounts of oxygen vacancies introduced by the dopant. Acceptor doping is believed to cause high oxygen vacancy concentrations, while donors are expected to strongly suppress their amount. In this study, La3+ donor-doped, Fe3+ acceptor-doped and La3+/Fe3+-co-doped PZT samples were investigated by oxygen tracer exchange and electrochemical impedance spectroscopy in order to analyse the effect of doping on oxygen vacancy concentrations. Relative changes in the tracer diffusion coefficients for different doping and quantitative relations between defect concentrations allowed estimates of oxygen vacancy concentrations. Donor doping does not completely suppress the formation of oxygen vacancies; rather, it concentrates them in the grain boundary region. Acceptor doping enhances the amount of oxygen vacancies but estimates suggest that bulk concentrations are still in the ppm range, even for 1% acceptor doping. Trapped holes might thus considerably contribute to the charge balancing of the acceptor dopants. This could also be of relevance in understanding the properties of hard and soft PZT. PMID:28774067

  14. Design Optimization of PZT-Based Piezoelectric Cantilever Beam by Using Computational Experiments

    Science.gov (United States)

    Kim, Jihoon; Park, Sanghyun; Lim, Woochul; Jang, Junyong; Lee, Tae Hee; Hong, Seong Kwang; Song, Yewon; Sung, Tae Hyun

    2016-08-01

    Piezoelectric energy harvesting is gaining huge research interest since it provides high power density and has real-life applicability. However, investigative research for the mechanical-electrical coupling phenomenon remains challenging. Many researchers depend on physical experiments to choose devices with the best performance which meet design objectives through case analysis; this involves high design costs. This study aims to develop a practical model using computer simulations and to propose an optimized design for a lead zirconate titanate (PZT)-based piezoelectric cantilever beam which is widely used in energy harvesting. In this study, the commercial finite element (FE) software is used to predict the voltage generated from vibrations of the PZT-based piezoelectric cantilever beam. Because the initial FE model differs from physical experiments, the model is calibrated by multi-objective optimization to increase the accuracy of the predictions. We collect data from physical experiments using the cantilever beam and use these experimental results in the calibration process. Since dynamic analysis in the FE analysis of the piezoelectric cantilever beam with a dense step size is considerably time-consuming, a surrogate model is employed for efficient optimization. Through the design optimization of the PZT-based piezoelectric cantilever beam, a high-performance piezoelectric device was developed. The sensitivity of the variables at the optimum design is analyzed to suggest a further improved device.

  15. Application of Multiplexed FBG and PZT Impedance Sensors for Health Monitoring of Rocks

    Directory of Open Access Journals (Sweden)

    Yingxin Zhou

    2008-01-01

    Full Text Available Reliable structural health monitoring (SHM including nondestructiveevaluation (NDE is essential for safe operation of infrastructure systems. Effectivemonitoring of the rock components of civil infrastructures such as tunnels and cavernsremains challenging. The feasibility of employing smart optical fibre sensor (OFS andpiezoelectric impedance sensor made up of lead zirconate titanate (PZT forcomprehensive health monitoring of rocks, covering load history monitoring/retrieval aswell as damage assessment is presented in this paper. The rock specimens are subjected tocyclic loading and their conditions are continuously monitored using OFS and PZTsensors. OFS based multiplexed fibre Bragg grating (FBG sensors are surface bonded onthe rock specimens. Their strain sensing performance is compared with the conventionalelectric strain gauges (ESGs. In addition, PZT patches are also bonded on the specimensto study the damage pattern during different loading cycles. Unlike the FBGs or ESGs,PZT patches are used as bi-functional sensors and actuators, enabling them to be efficientdetectors of incipient damages using the principle of electromechanical impedance. Theexperimental study demonstrated superior performance of these smart FBG and PZTimpedance sensors. This work is expected to be useful for SHM based NDE application ofrock structures such as caverns and tunnels.

  16. Thick-film force, slip and temperature sensors for a prosthetic hand

    Science.gov (United States)

    Cranny, A.; Cotton, D. P. J.; Chappell, P. H.; Beeby, S. P.; White, N. M.

    2005-04-01

    Thick-film static and dynamic force sensors have been investigated for their suitability to measure the grip forces exerted upon an object held by a prosthetic hand, and to detect and correspondingly react to the possible slip of a gripped item. The static force sensors exploit the piezoresistive characteristics of commercially available thick-film pastes whilst the dynamic slip sensors utilize the piezoelectric behaviour of proprietary PZT (lead zirconate titanate) pastes. The sensors are located upon stainless steel cantilever type structures that will be placed at the fingertips of each digit of the prosthetic hand. Temperature sensors are also included to provide temperature compensation for the force sensors and to prevent accidental thermal damage to the prosthesis. Results have shown that the static force sensor is capable of measuring fingertip forces in excess of 100 N, with an electrical half-bridge configuration sensitivity approaching 10 µV V-1 N-1 (with scope for improvement) and maximum hysteresis below 4% of full scale, depending on the manner in which the cantilever sensor array is attached to the finger. Failure in the bonding mechanism that secures the PZT layer to the stainless steel cantilever meant that the proposed dynamic force sensor could not be evaluated. However, investigations using the same sensor design fabricated on an alumina substrate have shown the potential of the PZT dynamic force sensor to measure the vibration and hence potentially operate as a slip sensor.

  17. Lamb wave characteristics of thickness-graded piezoelectric IDT.

    Science.gov (United States)

    Roy Mahapatra, D; Singhal, A; Gopalakrishnan, S

    2005-10-01

    An equivalent single layer model of Lamb wave generation by thickness-graded piezoelectric IDT on host structure is developed. Various additional complexities, such as the coupling between the Lamb wave modes, complicated nature of the electro-mechanical excitation are considered. The model of infinite IDT is extended to deal with the finite IDT with edge discontinuities. The effects of electromechanical coupling and thickness gradation on the wavelength shifts are investigated. The problem of electrically driven instability within the IDT is analyzed. Numerical results are reported by considering Al2O3/PZT IDT as integral part of the host structure, which show that there are significant changes and improvements in the Lamb wave characteristics due to the graded configuration. Most important among these is the reduced dispersiveness of the Lamb wave modes, which is useful in launching a SAW that propagates with narrower pulse width and less attenuation.

  18. The evaluatin of the thickness on the color of Composite resin by Crystaleye.%应用Crystaleye比色仪评价复合树脂厚度对颜色的影响

    Institute of Scientific and Technical Information of China (English)

    刘敬东; 张英

    2015-01-01

    目的:应用Crystaleye比色仪评价厚度对复合树脂表面颜色的影响.方法:根据Vita比色板A3色调选取新鲜人离体上颌中切牙56颗,随机分为8组,每组7颗牙.实验组7组,将不同厚度(0.8 mm,1.0 mm,1.2 mm,1.4 mm, 1.6 mm,1.8 mm,2.0 mm) 的FiltekTM Z350复合树脂光固化于每组牙齿的唇面, 对照组牙齿表面不作任何处理, 使用Crystaleye比色仪测定每组牙齿表面的颜色,计算在相同底色材料下,不同厚度复合树脂牙齿表面的色差△E*. 采用SPSS14.0软件对实验数据进行统计学分析. 结果:随着FiltekTM Z350复合树脂厚度的增加,牙齿表面的L*值、a*值与b*值均逐渐降低,各组间差异有统计学意义;在与对照组之间的色差值比较中,1.2 mm和1.4 mm厚度组与对照组之间的色差值均小于1.5 NBS. 在厚度组两两之间的比较中,相邻厚度组之间的色差均小于1.5 NBS,其他任意不相邻厚度组之间的色差比较均大于1.5 NBS. 结论:复合树脂的厚度变化可明显改变牙齿表面的颜色.%Objective:To evaluate the effect of the thickenss of composite resin on the final color of teeth by Crystal-eye. Method:According to the Vita shade guide color A3,fivty-six extracted human maxillary central incisor were collect-ed,dived into eight groups,experimental groups were seven,FiltekTM Z350 composite resin were fabricated at thickness of 8 mm,1.0 mm,1.2 mm,1.4 mm,1.6 mm,1.8 mm and 2.0 mm.None was fabricated in the control group.The CIE L*a*b*values of teeth were measured by a colorimeter (Crystaleye)to determine the colorimetric difference, when different thickness of composite resin were overlaid at the same backgrounds. SPSS14.0 software package was used for statistical analysis. Result:With the increase of the thickness of composite resin,the L*value,a*value and b* value were gradually decreased,statisti-cally significant were found. In the comparison of color,the color difference values of 1.4 mm thickness group and the

  19. Applicability of X-ray fluorescence spectroscopy as method to determine thickness and composition of stacks of metal thin films: A comparison with imaging and profilometry

    NARCIS (Netherlands)

    Vrielink, J.A.M.; Tiggelaar, R.M.; Gardeniers, J.G.E.; Lefferts, L.

    2012-01-01

    In this work the applicability of X-ray fluorescence spectroscopy (XRF) for fast, accurate and non-destructive determination of the thickness of a variety of single-layer and multi-layer metal thin films deposited on glass and silicon is investigated. Data obtained with XRF is compared with informat

  20. Comparison of Film Thickness of Two Commercial Brands of Glass lonomer Cement and One Dual-cured Composite: An in vitro Study.

    Science.gov (United States)

    Khajuria, Rajat R; Singh, Rishav; Barua, Pranamee; Hajira, Nausheen; Gupta, Naveen; Thakkar, Rohit R

    2017-08-01

    The present study is undertaken to examine the film thickness of three most commonly used luting cements and to determine their usage as a luting agent. This study was carried out strictly according to the guidelines of American Dental Association (ADS) specification no. 8. Two glass slabs of 5 cm in length and 2 cm in width were used. One glass slab was kept over the other glass slab and the space between the two glass slabs was measured using metallurgical microscope at the power of 10*. Two brands of glass ionomer cement (GIC) and one dual-cured resin cement were used in this study. The test cement is sandwiched between two glass slabs. A static load of 15 kg was applied using universal testing machine on the glass slabs for 1 hour and the space present between the two glass slabs was measured using metallurgical microscope at the power of 10*. Greatest film thickness was found in group III (Paracore) followed by group II (micron) and lowest in group I (GC luting and lining cement). All the tested samples can be used for luting purposes. Greatest film thickness was observed in Paracore followed by micron and lowest in GC luting and lining cement. This suggests that the 25 to 27°C is ideal for mixing of the cement when used for luting consistency. The cement with film thickness more than 30 urn should never be used for luting purposes. The dentist should choose the luting cement with utmost care noting the film thickness and bond strength of the cement. The cement with low exothermic heat production and good bond strength should be encouraged.

  1. Performance of PIN-PMN-PT Single Crystal Piezoelectric versus PZT8 Piezoceramic Materials in Ultrasonic Transducers

    Science.gov (United States)

    DeAngelis, D. A.; Schulze, G. W.

    The recent advancements in the manufacturing of single crystal PIN-PMN-PT piezoelectric materials now make them a cost-competitive alternative to PZT4 and PZT8 (Navy Types I and III) piezoceramic materials, which have been the workhorse of power ultrasonic applications (e.g., welding, cutting, sonar, etc.) for over 50 years. Although there are great benefits to the use of single crystal materials with respect to high output, as well as added actuating and sensing abilities, many transducer designers are still reluctant to explore these materials due to inadequate design guidelines for substituting the familiar PZT materials; for example, what are the implications of the higher capacitance, sensitivity to chipping/cracks, aging effects, frequency shifts, or how much preload can be used are all common questions. This research is a case study on the performance of identical ultrasonic transducer bodies, used for semiconductor wire bonding, assembled with either PZT8 or PIN-PMN-PT piezo material. The main purpose of the study is to establish rule-of-thumb design guidelines for direct substitution of single crystal materials in existing PZT8 transducer designs, along with a side-by-side performance comparison to highlight benefits. Several metrics are investigated such as impedance, frequency, displacement gain, quality factor and electromechanical coupling factor.

  2. Real time monitoring of spot-welded joints under service load using lead zirconate titanate (PZT) transducers

    Science.gov (United States)

    Yao, Ping; Zheng, Botong; Dawood, Mina; Huo, Linsheng; Song, Gangbing

    2017-03-01

    This paper proposes a nondestructive method to evaluate the health status of resistance spot-welded (RSW) joint under service load using lead zirconate titanate (PZT) active sensing system, in which the PZT transducers were used as both actuator and sensor. The physical principle of the approach was validated through a numerical analysis showing that an opening between the faying faces at the welded joint occurred under tension load. The opening decreased the contact area hence reduced the amplitude of the stress wave received by the PZT sensor. Therefore, by comparing the energy index of the signals before and after the loading, the health condition of the joint can be evaluated. Five ST14 steel single lap joint specimens were tested under tension load while being monitored by the PZT sensing system and digital image correlation (DIC) system in real time. The data obtained from the DIC system validated the numerical results. By comparing the energy index of the signal obtained from the PZT sensing system before and after unloading, it was concluded that the RSW joint was intact after being loaded to the service load. The proposed method is promising in evaluating the health condition of RSW joint nondestructively.

  3. Enhanced voltage-controlled magnetic anisotropy in magnetic tunnel junctions with an MgO/PZT/MgO tunnel barrier

    Science.gov (United States)

    Chien, Diana; Li, Xiang; Wong, Kin; Zurbuchen, Mark A.; Robbennolt, Shauna; Yu, Guoqiang; Tolbert, Sarah; Kioussis, Nicholas; Khalili Amiri, Pedram; Wang, Kang L.; Chang, Jane P.

    2016-03-01

    Compared with current-controlled magnetization switching in a perpendicular magnetic tunnel junction (MTJ), electric field- or voltage-induced magnetization switching reduces the writing energy of the memory cell, which also results in increased memory density. In this work, an ultra-thin PZT film with high dielectric constant was integrated into the tunneling oxide layer to enhance the voltage-controlled magnetic anisotropy (VCMA) effect. The growth of MTJ stacks with an MgO/PZT/MgO tunnel barrier was performed using a combination of sputtering and atomic layer deposition techniques. The fabricated MTJs with the MgO/PZT/MgO barrier demonstrate a VCMA coefficient, which is ˜40% higher (19.8 ± 1.3 fJ/V m) than the control sample MTJs with an MgO barrier (14.3 ± 2.7 fJ/V m). The MTJs with the MgO/PZT/MgO barrier also possess a sizeable tunneling magnetoresistance (TMR) of more than 50% at room temperature, comparable to the control MTJs with an MgO barrier. The TMR and enhanced VCMA effect demonstrated simultaneously in this work make the MgO/PZT/MgO barrier-based MTJs potential candidates for future voltage-controlled, ultralow-power, and high-density magnetic random access memory devices.

  4. Detection of disbonds in a honeycomb composite structure using guided waves

    Science.gov (United States)

    Baid, Harsh; Banerjee, Sauvik; Joshi, Shiv; Mal, Siddhartha

    2008-03-01

    Advanced composites are being used increasingly in state-of-the-art aircraft and aerospace structures. In spite of their many advantages composite materials are highly susceptible to hidden flaws that may occur at any time during the life cycle of a structure and if undetected, may cause sudden and catastrophic failure of the entire structure. An example of such a defects critical structural component is the "honeycomb composite" in which thin composite skins are bonded with adhesives to the two faces of extremely lightweight and relatively thick metallic honeycombs. These components are often used in aircraft and aerospace structures due to their high strength to weight ratio. Unfortunately, the bond between the honeycomb and the skin may degrade with age and service loads leading to separation of the load-bearing skin from the honeycomb (called "disbonds") and compromising the safety of the structure. This paper is concerned with the noninvasive detection of disbonds using ultrasonic guided waves. Laboratory experiments are carried out on a composite honeycomb specimen containing localized disbonded regions. Ultrasonic waves are launched into the specimen using a broadband PZT transducer and are detected by a distributed array of identical transducers located on the surface of the specimen. The guided wave components of the signals are shown to be very strongly influenced by the presence of a disbond. The experimentally observed results are being used to develop an autonomous scheme to locate the disbonds and to estimate their size.

  5. Study of the microstructure and the hardness of PZT piezoelectric ceramics types I and III used in electro acoustic transducers; Estudo da microestrutura e da microdureza das ceramicas piezoeletricas tipos PZT I e III utilizadas em transdutores eletroacusticos

    Energy Technology Data Exchange (ETDEWEB)

    Cabral, Ricardo de Freitas; Itaboray, Lucas Mendes; Santos, Anna Paula de Oliveira [Centro Universitario de Volta Redonda (UNIFOA), Volta Redonda, RJ (Brazil)

    2015-12-15

    The field of electronic processing of the ceramic piezoelectric type imported powdered led to the production of ceramics with 97% of theoretical density, homogeneous microstructure with great potential for applications in piezoelectric devices such as electro acoustic transducers. However, the production of electronic ceramics National piezoelectric type is not yet able to have as raw material zirconate titanate Lead (PZT) 100% made in Brazil. Thus, this is used for supply of domestic production, the zirconium oxide. In this work, both post PZT types I and III, imported, were uniaxially pressed at 70 MPa and sintered at 1200 and 1250 deg C for 3 hours. Hardness measurements were performed by micro indentation, X-ray diffraction analysis and Scanning Electron Microscopy. The hardness of PZT I was 393 HV. (author)

  6. Direct strain energy harvesting in automobile tires using piezoelectric PZT-polymer composites

    NARCIS (Netherlands)

    Ende, D.A. van den; Wiel, H.J. van de; Groen, W.A.; Zwaag, S. van der

    2012-01-01

    Direct piezoelectric strain energy harvesting can be used to power wireless autonomous sensors in environments where low frequency, high strains are present, such as in automobile tires during operation. However, these high strains place stringent demands on the materials with respect to mechanical

  7. Unexpected behavior of transient current in thin PZT films caused by grain-boundary conduction

    Science.gov (United States)

    Delimova, L. A.; Guschina, E. V.; Seregin, D. S.; Vorotilov, K. A.; Sigov, A. S.

    2017-06-01

    The behavior of the transient current at different preliminary polarizations has been studied in Pb(ZrTi)O3 (PZT) films with various grain structures. To affect the grain structure, PZT films were prepared by chemical solution deposition with a two-step crystallization process using combination of seed layers with a low Pb excess and the main layers with a 30 wt. % Pb excess. Some films were prepared with a fixed Pb excess in all the deposited layers. We found that the lead excess and the seed layer crystalline structure can affect the grain-boundary conduction which, in turn, influences the polarization dependence of the transient current and the appearance of current peaks which look like the so-called negative differential resistance region in the current-voltage curves. We show that the emergence of the current peaks in the PZT films depends on (i) whether the current flows inside the ferroelectric phase (grains) or outside, along grain boundaries and (ii) whether the applied bias direction is parallel or opposite to the polarization vector. A correlation between the grain-boundary conduction and current-polarization dependences is confirmed by the local current distribution measured by conductive atomic force microscopy. Possible mechanisms responsible for specific features of the transient current and appearance of the current peaks are discussed. The effect of grain-boundary conduction on the behavior of the current may be significant and should be taken into account in ferroelectric random access memory whose readout operation assumes registration of the magnitude of the polarization switching current under positive bias.

  8. Speed of sound estimation with active PZT element for thermal monitoring during ablation therapy: feasibility study

    Science.gov (United States)

    Kim, Younsu; Guo, Xiaoyu; Cheng, Alexis; Boctor, Emad M.

    2016-04-01

    Controlling the thermal dose during ablation therapy is instrumental to successfully removing the tumor while preserving the surrounding healthy tissue. In the practical scenario, surgeons must be able to determine the ablation completeness in the tumor region. Various methods have been proposed to monitor it, one of which uses ultrasound since it is a common intraoperative imaging modality due to its non-invasive, cost-effective, and convenient natures. In our approach, we propose to use time of flight (ToF) information to estimate speed of sound changes. Accurate speed of sound estimation is crucial because it is directly correlated with temperature change and subsequent determination of ablation completeness. We divide the region of interest in a circular fashion with a variable radius from the ablator tip. We introduce the concept of effective speed of sound in each of the sub-regions. Our active PZT element control system facilitates this unique approach by allowing us to acquire one-way ToF information between the PZT element and each of the ultrasound elements. We performed a simulation and an experiment to verify feasibility of this method. The simulation result showed that we could compute the effective speed of sound within 0.02m/s error in our discrete model. We also perform a sensitivity analysis for this model. Most of the experimental results had less than 1% error. Simulation using a Gaussian continuous model with multiple PZT elements is also demonstrated. We simulate the effect of the element location one the optimization result.

  9. Composition

    DEFF Research Database (Denmark)

    2014-01-01

    Memory Pieces are open compositions to be realised solo by an improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them...

  10. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2010-01-01

    New Year is an open composition to be realised by improvising musicians. It is included in "From the Danish Seasons" (see under this title). See more about my composition practise in the entry "Composition - General Introduction". This work is licensed under a Creative Commons "by-nc" License. You...

  11. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2011-01-01

    Strategies are open compositions to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them in full...

  12. Polar-axis-oriented crystal growth of tetragonal PZT films on stainless steel substrate using pseudo-perovskite nanosheet buffer layer

    Directory of Open Access Journals (Sweden)

    Yoshiki Minemura

    2015-07-01

    Full Text Available Lead zirconate titanate (PZT film with polar axis orientation was grown on a SUS 316L stainless steel substrate with the help of a Ca2Nb3O10 nanosheet (ns-CN layer that had a pseudo-perovskite-type crystal structure. The ns-CN buffer layer was supported on a platinized SUS 316L (Pt/SUS substrate, followed by chemical solution deposition (CSD of the PZT films with tetragonal symmetry (Zr/Ti =40/60. The PZT films consisting of c-domain, with [001]-axis orientation of the perovskite unit cell, were deposited on the ns-CN/Pt/SUS substrate owing to (i epitaxial lattice matching between the unit cell of PZT and substrate surface and (ii in-plane thermal stress applied to the PZT film during cooling-down step of CSD procedure. The c-domain-oriented PZT film on ns-CN/Pt/SUS substrate exhibited enhanced remanent polarization of approximately 52 μC/cm2 and lowered dielectric permittivity of approximately 230, which are superior to those of conventional PZT films with random crystal orientation and comparable to those of epitaxial PZT films grown on (100SrRuO3//(100SrTiO3 substrates.

  13. Ferroelectric switching of band alignments in LSMO/PZT/Co multiferroic tunnel junctions: an ab initio study

    Science.gov (United States)

    Imam, M.; Stojić, N.; Binggeli, N.

    2017-08-01

    Band alignments in ferroelectric tunnel junctions (FTJs) are expected to play a critical role in determining the charge transport across the tunneling barrier. In general, however, the interface band discontinuities and their polarization dependence are not well known in these systems. Using a first-principles density-functional-theory approach, we explore the ferroelectric (FE) polarization dependence of the band alignments in {{La}}0.7{{Sr}}0.3{{MnO}}3/{{PbZr}}0.2{{Ti}}0.8{{{O}}}3/{Co} (LSMO/PZT/Co) multiferroic tunnel junctions, for which recent experiments indicated an ON/OFF conductivity behavior upon switching the PZT FE polarization. Our results on the pseudomorphic defect-free LSMO/PZT/Co FTJs evidence a major FE switching effect on the band discontinuities at both interfaces. Based on the changes in the band alignments, we provide a possible explanation for the observed trends in the resistive switching.

  14. Highly polarized single-c-domain single-crystal Pb(Mn,Nb)O(3)-PZT thin films.

    Science.gov (United States)

    Wasa, Kiyotaka; Adachi, Hideaki; Nishida, Ken; Yamamoto, Takashi; Matsushima, Tomoaki; Kanno, Isaku; Kotera, Hidetoshi

    2012-01-01

    In-plane unstrained single-c-domain/single-crystal thin films of PZT-based ternary ferroelectric perovskite, ξPb(Mn,Nb)O3-(1 - ξ)PZT, were grown on SrRuO(3)/Pt/MgO substrates using magnetron sputtering followed by quenching. The sputtered unstrained thin films exhibit unique ferroelectric properties: high coercive field, Ec > 180 kV/cm, large remanent polarization, P(r) = 100 μC/cm(2), small relative dielectric constants, ε* = 100 to 150, high Curie temperature, Tc = ~600 °C, and bulk-like large transverse piezoelectric constants, e31,f = -12.0 C/m(2) for PZT(48/52) at ξ = 0.06. The unstrained thin films are an ideal structure to extract the bulk ferroelectric properties. Their micro-structures and ferroelectric properties are discussed in relation to the potential applications for piezoelectric MEMS. © 2012 IEEE

  15. In situ X-ray diffraction based investigation of crystallization in solution deposited PZT thin films

    Science.gov (United States)

    Nittala, Krishna

    Solution deposited PZT based thin films have potential applications in embedded decoupling capacitors and pulse discharge capacitors. During solution deposition, precursor solution is deposited onto a substrate to obtain an amorphous film. The film is then crystallized by heating it at a high temperature (˜600 - 700°C). Conditions during the crystallization anneal such as precursor stoichiometry in solution, heating rate and adhesion layer in the substrate are known to influence phase and texture evolution in these films. However, a mechanistic understanding of the changes taking place in these thin films during crystallization is lacking. A better understanding of the crystallization processes in these thin films could enable tailoring the properties of thin films to suit specific applications. To explore the crystallization process in solution deposited PZT thin films, high temperature in situ laboratory and synchrotron X-ray diffraction based techniques were developed. Taking advantage of the high X-ray flux available at synchrotron facilities such as beamline 6-ID-B, Advanced Photon Source, Argonne National Laboratory, crystalline phases formed in the thin films during crystallization at the high heating rates (0.5 -- 60°C/s) typically used during film processing could be measured. Using a 2-D detector for these measurements allowed the simultaneous measurement of both phase and texture information during crystallization. Analytical treatment of the unconventional diffraction geometry used during the synchrotron based measurements was performed to develop methodologies for quantitative estimation of texture components. The nominal lead content in the starting solutions and the heating rate used during crystallization was observed to influence the sequence of phases formed during crystallization of the films. In films crystallized at fast heating rates, titanium segregation, probably due to diffusion of titanium from the adhesion layer, was observed. To

  16. Luminescence of Eu{sup 3+} incorporated into PZT tetragonal ceramics prepared by sol-gel

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Federico; Schabes-Retchkiman, Pablo; GarcIa-Macedo, Jorge [Instituto de FIsica, Universidad Nacional Autonoma de Mexico, A.P. 20-364, 01000 Mexico, D.F. (Mexico)

    2004-09-07

    Luminescence of Eu{sup 3+} in Pb(Zr{sub x}Ti{sub 1-x})O{sub 3} (PZT) polycrystalline tetragonal samples synthesized by sol-gel processing is reported. Studies by x-ray diffraction, energy dispersive spectroscopy and high resolution transmission electron microscopy demonstrate the incorporation of the dopant in the host. A broad charge transfer band centred around 266 nm was observed in the Eu{sup 3+} excitation spectra. Eu{sup 3+} is in a low symmetry site. Luminescence was lost between 673 and 1173 K. It was recovered after 1 h of heat treatment at 1273 K, when nanocrystallites were formed.

  17. Preparation and Properties of Orthogonal Piezoelectric Composite Materials

    Institute of Scientific and Technical Information of China (English)

    Liu Jun; Lu Ying; Zhang Xingguo; Shen Yi; Chen Chun

    2004-01-01

    . PZT piezoelectric ceramic with La2O3, SrCO3, BaO and Sb2O5 was prepared. It has high value of the piezoelectric strain constant d33 ( -681 PC/N) and high value of-d33/d31 (2.65). Orthogonal piezoelectric composite materials was designed and prepared by PZT, DAD- 40 electric conductive adhesive and E51 epoxy resin. The OPCM shows obvious orthogonal anisotropy. The matching property of the interface between piezoelectric ceramic and polymer of OPCM relies on the defects of interface. The proper conductive mid-layer could improve the matching property of the interface.

  18. The effects of dimensional parameters on sensing and energy harvesting of an embedded PZT in a total knee replacement

    Science.gov (United States)

    Safaei, Mohsen; Anton, Steven R.

    2016-04-01

    Total Knee Replacement (TKR), one of the most common surgeries in the United States, is performed when the patient is experiencing significant amounts of pain or when knee functionality has become substantially degraded. Despite impressive recent developments, only about 85% of patients are satisfied with the pain reduction after one year. Therefore, structural health and performance monitoring are integral for intraoperative and postoperative feedback. In extension of the author's previous work, a new configuration for implementation of piezoelectric transducers in total knee replacement bearings is proposed and FEA modeling is performed to attain appropriate sensing and energy harvesting ability. The predicted force transmission ratio to the PZT (ratio of force applied to the bearing to force transferred to the embedded piezoelectric transducer) is about 6.2% compared to about 5% found for the previous encapsulated design. Dimensional parameters of the polyethylene bearing including the diameter and depth of the PZT pocket as well as the placement geometry of the PZT transducer within the bearing are hypothesized as the most influential parameters on the performance of the designed system. The results show a small change of 1% and 2.3% in the output of the system as a result of variation in the PZT location and pocket diameter, respectively. Whereas, the output of the system is significantly sensitive to the pocket depth; a pocket 0.01 mm deeper than the PZT transducer leads to no force transmission, and a pocket 0.15 mm shallower leads to full load transmission to the PZT. In order to develop a self-powered sensor, the amount of energy harvested from tibial forces for the proposed geometry is investigated.

  19. The influence of the point defects on the relaxation processes in a ceramics of the PZT type

    Energy Technology Data Exchange (ETDEWEB)

    Brus, B.; Zachariasz, R.; Ilczuk, J. [Silesian University, Faculty of Computer and Material Science, Department of Material Science, 3 Zeromskiego St., 41-200 Sosnowiec (Poland)

    2004-03-01

    The aim of the present study is twofold: to measure phase transition temperatures and study the relaxation peaks observed in the internal friction for the doped PZT ceramics, with the chemical composition: Pb{sub 0.975}Ba{sub 0.01}Ca{sub 0.01}Sr{sub 0.005}(Zr{sub 0.52}Ti{sub 0.48})O{sub 3}+1.4 wt% Bi{sub 2}O{sub 3}+0.3 wt% GeO. For all measurements, the specimens are rectangular bars (dimensions 30 x 10 x 0,9 mm{sup 3}), some specimens were subjected to polarization by low temperature method (T=423 K, E{sub p}=30 kV/cm, t=30 min) and others were irradiated by {gamma} radiation. Measurements were conducted on a computer-controlled automatic resonant mechanical spectrometer, while heating at different heating rates (1-5 K/min.) and two different frequencies: 930 and 1015 Hz. On the curves Q{sup -1}(T) two maxima of internal friction were observed; P{sub R} at T{sub 1}=382 K (930 Hz), T{sub 1}=386 K (1015 Hz) and P{sub F} at T{sub 2}=638 K (930 and 1015 Hz). The P{sub F} peak originates from the ferroelectric-paraelectric phase transformation; the relaxation peak P{sub R} can be explained in terms of Postnikov's model involving the interaction between mobile point defects and stationary 90 domain walls. The activation parameters of P{sub R} peak deduced from Arrhenius law are respectively: H{sub R}=(0.86{+-}0.02) eV and {tau}{sub oR}=(1.43{+-}0.04) x 10{sup -15} s. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Formación de fases en materiales cerámicos PZT dopados con fósforo

    OpenAIRE

    2001-01-01

    [ES] La modificación superficial de materiales cerámicos titanato circonato de plomo (PZT) con ester fosfato deja un residuo de cationes de fósforo adsorbidos en la superficie de las partículas de este polvo. Durante el proceso de sinterización, esta capa superficial reacciona con el material PZT para formar compuestos ricos en plomo, como el Pb3(PO4)2 y el Pb4(P2O9). La formación de estos compuestos está en el origen de la inhibición del crecimiento de grano observada en materiales ...

  1. Electric properties of textured (K$_{0.44}$Na$_{0.52}$Li$_{0.04}$)(Nb$_{0.86}Ta$_{0.10}$Sb$_{0.04}$)O$_3$ thick film prepared by screen printing method

    Indian Academy of Sciences (India)

    FANG FU; JIWEI ZHAI; ZHENGKUI XU

    2016-08-01

    Textured (K$_{0.44}$Na$_{0.52}$Li$_{0.04}$) (Nb$_{0.86}$Ta$_{0.10}$Sb$_{0.04}$)O$_3$ thick film was fabricated by the screen printing method with plate-like NaNbO3 particles as template. Thick film with 75% grain orientation was prepared. Remnant polarization and coercive field observed from the P–E loops of textured thick film were 3.6 $\\mu$C cm$^{−2}$ and 21 kV cm$^{−1}$, respectively. Textured (K$_{0.44}$Na$_{0.52}$Li$_{0.04}$) (Nb$_{0.86}$Ta$_{0.10}$Sb$_{0.04}$)O$_{3}$ thick film exhibited diffusion behaviour by analysing the temperature dependence of permittivity and loss tangent. The result of leakage current density showed a conduction mechanism of Schottky emission. Piezoelectric (PZT) properties of the thick film were characterized by the relationship of unipolar strain and applied electric field and the PZT constant $d^∗_{33}$ of textured thick film reached to 150 pm V$^{−1}$. Nonlinear PZT property of the thick film was investigated by Rayleigh law.

  2. Magnetic field-dependent polarization of (111)-oriented PZT–Co ferrite nanobilayer: Effect of Co ferrite composition

    Energy Technology Data Exchange (ETDEWEB)

    Khodaei, M. [Advanced Magnetic Materials Research Center, School of Metallurgy and Materials, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Faculty of Materials Science and Engineering, K. N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of); Seyyed Ebrahimi, S.A., E-mail: saseyyed@ut.ac.ir [Advanced Magnetic Materials Research Center, School of Metallurgy and Materials, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Jun Park, Yong [Pohang Accelerator Laboratory, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of); Son, Junwoo; Baik, Sunggi [Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of)

    2015-05-15

    The perfect (111)-oriented PZT/CFO (CFO=CoFe{sub 2}O{sub 4}, Co{sub 0.8}Fe{sub 2.2}O{sub 4} and Co{sub 0.6}Mn{sub 0.2}Fe{sub 2.2}O{sub 4}) bilayer multiferroic thin films were grown on Pt(111)/Si substrate at 600 °C using pulsed laser deposition technique. The precision X-ray diffraction analysis (avoiding the shift of peak due to the sample misalignment) revealed that the CFO films on Pt(111)/Si substrate were under an out-of-plane contraction and deposition of PZT top layer led to more increase in the out-of-plane contraction, i.e. increase in the residual stresses. The PZT and CFO layers have significant effects on magnetic and ferroelectric properties of PZT/CFO bilayer films, respectively, leading to an enhanced in-plane magnetic anisotropy as well as increased and asymmetric polarization. The effect of composition of CFO layer on magnetic field-dependent polarization of PZT/CFO bilayer films was investigated by applying the magnetic field during P-E measurement. The polarization of PZT films were increased by applying the magnetic field as a result of strain transferred from magnetostrictive CFO underlayer. This increase in polarization for PZT/Co{sub 0.6}Mn{sub 0.2}Fe{sub 2.2}O{sub 4} was higher than that for PZT/Co{sub 0.8}Fe{sub 2.2}O{sub 4} and both of them were significantly higher than that for PZT/CoFe{sub 2}O{sub 4} bilayer film, which was discussed based on their magnetostriction properties. - Highlights: • The effect of composition of CFO on P–E characteristics of PZT/CFO films was investigated. • The polarization of PZT films were increased by applying the magnetic field. • The increasing polarization was a result of strain from magnetostrictive CFO underlayer.

  3. Thick Films acoustic sensors devoted to MTR environment measurements. Thick Films acoustic sensors devoted to Material Testing Reactor environment measurements

    Energy Technology Data Exchange (ETDEWEB)

    Very, F.; Rosenkrantz, E.; Combette, P.; Ferrandis, J.Y. [University Montpellier, IES, UMR 5214, F-34000, Montpellier (France); CNRS, IES, UMR 5214, F-34000, Montpellier (France); Fourmentel, D.; Destouches, C.; Villard, J.F. [CEA, DEN, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St Paul lez Durance (France)

    2015-07-01

    The development of advanced instrumentation for in-pile experiments in Material Testing Reactor constitutes a main goal for the improvement of the nuclear fuel behavior knowledge. An acoustic method for fission gas release detection was tested with success during a first experiment called REMORA 3 in 2010 and 2011, and the results were used to differentiate helium and fission gas release kinetics under transient operating conditions. This experiment was lead at OSIRIS reactor (CEA Saclay, France). The maximal temperature on the sensor during the irradiation was about 150 deg. C. In this paper we present a thick film transducer produce by screen printing process. The screen printing of piezoelectric offers a wide range of possible applications for the development of acoustic sensors and piezoelectric structure for measurements in high temperature environment. We firstly produced a Lead Zirconate Titanate (PZT) based paste composed of Pz27 powder from Ferroperm, CF7575 glass, and organic solvent ESL 400. Likewise a Bismuth Titanate based paste synthesized in our laboratory was produced. With these inks we produced thick film up to 130 μm by screen printing process. Material properties characterizations of these thick-film resonators are essential for device design and applications. The piezoelectric coefficients d33 and pyro-electric P(T) coefficient are investigated. The highest P(T) and d33 are respectively 80 μC.m{sup -2}.K{sup -1} and 130 μC.N{sup -1} for the PZT transducer -which validates the fabrication process-. In view of the development of this transducer oriented for high temperature and irradiation environment, we investigated the electrical properties of the transducers for different ranges of frequencies and temperature - from 20 Hz up to 40 MHz between 30 and 400 deg. C. We highlight the evolution of the impedance response and piezoelectric parameters of screen printed piezoelectric structures on alumina. Shortly an irradiation will be realized in

  4. Magnetoelectric thin film composites with interdigital electrodes

    Science.gov (United States)

    Piorra, A.; Jahns, R.; Teliban, I.; Gugat, J. L.; Gerken, M.; Knöchel, R.; Quandt, E.

    2013-07-01

    Magnetoelectric (ME) thin film composites on silicon cantilevers are fabricated using Pb(Zr0.52Ti0.45)O3 (PZT) films with interdigital transducer electrodes on the top side and FeCoSiB amorphous magnetostrictive thin films on the backside. These composites without any direct interface between the piezoelectric and magnetostrictive phase are superior to conventional plate capacitor-type thin film ME composites. A limit of detection of 2.6 pT/Hz1/2 at the mechanical resonance is determined which corresponds to an improvement of a factor of approximately 2.8 compared to the best plate type sensor using AlN as the piezoelectric phase and even a factor of approximately 4 for a PZT plate capacitor.

  5. Microestructura y propiedades de materiales cerámicos PZT con control de crecimiento de grano

    Directory of Open Access Journals (Sweden)

    Celi, L. A.

    1999-10-01

    Full Text Available Lead zirconate titanate ceramic powders have been surface modified by using phosphor esther 0.3% in volume. The phosphorous modification gave higher densities at lower temperatures associated with a reduction of the weight losses during the densification process. From the relationships between ceramic processing and microstructure, it was established that the phosphorous surface modification allows the effective grain growth control as well a higher homogeneity in the grain size distribution.

    Se ha realizado un proceso de modificación superficial con ester fosfato al 0.3% en volumen, sobre polvo cerámico de titanato circonato de plomo, PZT. Se observa que el material modificado con fósforo presenta una mayor densificación aparente a una temperatura menor unida a una reducción de las pérdidas de peso durante el proceso de densificación. Se han establecido las relaciones entre el procesamiento y las microestructuras del material PZT sin modificar y el modificado. Se evidencia un control del crecimiento de grano y una mayor homogeneidad en la distribución de tamaños de grano en el material modificado.

  6. Design Considerations for Aural Vital Signs Using PZT Piezoelectric Ceramics Sensor Based on the Computerization Method

    Directory of Open Access Journals (Sweden)

    Jerapong Tantrakoon

    2007-11-01

    Full Text Available The purpose was to illustrate how system developed for measurement of the aural vital signs such as patient’s heart and lung sounds in the hospital. For heart sounds measurement must operate the frequency response between 20 – 800 Hz, and lung sounds measurement must operate the frequency response between 160 – 4,000 Hz. The method was designed PZT piezoelectric ceramics for both frequency response in the same PZT sensor. It converts a signal from aural vital sign form to voltage signal. The signal is suitably amplified and re-filtered in band pass frequency band. It is converted to digital signal by an analog to digital conversion circuitry developed for the purpose. The results were that all signals can fed to personal computer through the sound card port. With the supporting software for drawing of graphic on the screen, the signal for a specific duration is accessed and stored in the computer’s memory in term of each patient’s data. In conclusion, the data of each patient call dot pcg (.pcg for drawing graph and dot wave (.wave for sound listening or automatic sending via electronic mail to the physician for later analysis of interpreting the sounds on the basis of their time domain and frequency domain representation to diagnose heart disorders.

  7. Polarization-dependent interfacial coupling modulation of ferroelectric photovoltaic effect in PZT-ZnO heterostructures.

    Science.gov (United States)

    Pan, Dan-Feng; Bi, Gui-Feng; Chen, Guang-Yi; Zhang, Hao; Liu, Jun-Ming; Wang, Guang-Hou; Wan, Jian-Guo

    2016-03-08

    Recently, ferroelectric perovskite oxides have drawn much attention due to potential applications in the field of solar energy conversion. However, the power conversion efficiency of ferroelectric photovoltaic effect currently reported is far below the expectable value. One of the crucial problems lies in the two back-to-back Schottky barriers, which are formed at the ferroelectric-electrode interfaces and blocking most of photo-generated carriers to reach the outside circuit. Herein, we develop a new approach to enhance the ferroelectric photovoltaic effect by introducing the polarization-dependent interfacial coupling effect. Through inserting a semiconductor ZnO layer with spontaneous polarization into the ferroelectric ITO/PZT/Au film, a p-n junction with strong polarization-dependent interfacial coupling effect is formed. The power conversion efficiency of the heterostructure is improved by nearly two orders of magnitude and the polarization modulation ratio is increased about four times. It is demonstrated that the polarization-dependent interfacial coupling effect can give rise to a great change in band structure of the heterostructure, not only producing an aligned internal electric field but also tuning both depletion layer width and potential barrier height at PZT-ZnO interface. This work provides an efficient way in developing highly efficient ferroelectric-based solar cells and novel optoelectronic memory devices.

  8. Investigation of Co-doped PZT films deposited by rf-magnetron sputtering

    Directory of Open Access Journals (Sweden)

    Felicia Gheorghiu

    2014-09-01

    Full Text Available The focus of the present paper is to describe the preparation procedure and to investigate the microstructural characteristics and the electrical properties of Co-doped PZT films deposited by rf-sputtering by using a “mixture” target system onto Au-electroded Al2O3 ceramic substrates. The X-ray diffraction patterns of the Co-doped PZT thin films as a function of the annealing temperature confirmed the formation of pure perovskite phase started with temperatures of 600 °C, but a perfect crystallization was achieved at a temperature of ∼700 °C. The microstructures strongly depend on the thermal treatment temperature and indicated a discontinuous surface without large pores and with a bimodal grain size distribution. The XPS analysis demonstrated that the dopant element is present mainly in its Co2+ state. The macroscopic P(E hysteresis loops were recorded in different locations of the films surface and demonstrated ferroelectric behaviour with a resistive leakage contribution.

  9. Study on delayed cracking of conductive notch under electric field in PZT-5H ferroelectric ceramics

    Institute of Scientific and Technical Information of China (English)

    QIAO Guangli; SU Yanjing; QIAO Lijie; CHU Wuyang

    2006-01-01

    Electric-field-induced delay cracking of conducting notch in PZT-5H ferroelectric ceramics has been studied using a compact specimen with a notch filled in conductive silver paste. The critical electric field that induces instant failure of the PZT-5H specimen is shown to be EF = 14.7(3.2 kV/cm. When an electric field lower than EF, but higher than EDF = 9.9 kV/cm was applied, a micro-crack formed at the conductive notch tip instantly, propagating slowly until the specimen failure. When the electric field was lower than EDF, the micro-crack propagated a short distance, and then stopped. When the electric field was lower than EK=4.9 kV/cm, no cracks formed at the conductive notch tip instantly, however, a delay micro-crack would form and propagate. When the electric field was lower than EDK=2.4 kV/cm, no cracks formed and delay propagation occurred. A model for electric charge emission and concentration at a conductive notch is proposed to explain the delay cracking of conducting notch.

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

    Science.gov (United States)

    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.

  11. PZT95/5陶瓷电致失效机理研究%Failure mechanism of PZT 95/5 under direct current and pulsed electric field

    Institute of Scientific and Technical Information of China (English)

    张福平; 杜金梅; 刘雨生; 刘艺; 刘高旻; 贺红亮

    2011-01-01

    The failure mechanism of PZT 95/5 under direct current and pulsed electric field is studied by experiment and theoretical analysis in this paper. The electrothermal coupled failure is the key mode when the PZT 95/5 is subjected to direct current. But when the pulsed electric field is applied to the PZT 95/5, the resonance effect and the relation between energy and frequency being considered, the vibrant energy shifts to high frequency and the possibility of electromechanical-coupled failure is increased with decreasing pulse duration. When the pulse duration is increased, the failure behavior transfers gradually from mechanical coupled with electric failure to direct current failure mode.%对PZT 95/5陶瓷在直流电场、脉冲方波电场以及半正弦波电场作用下的失效机理进行了理论和实验分析.结果表明:在直流作用下,其失效机理以热-电耦合失效为主;而在脉冲电场作用下,考虑振动冲击效应以及相关的力谱分布,脉宽越短,能量向高频偏移,越可能发生力-电耦合失效;当脉宽增加,PZT 95/5陶瓷失效机理将从力-电耦合失效逐步转变成直流失效模式.

  12. Bulk dielectric and magnetic properties of PFW-PZT ceramics: absence of magnetically switched-off polarization.

    Science.gov (United States)

    Kempa, M; Kamba, S; Savinov, M; Maryško, M; Frait, Z; Vaněk, P; Tomczyk, M; Vilarinho, P M

    2010-11-10

    We investigated ceramics samples of solid solutions of [PbFe(2/3)W(1/3)O(3)](x)-[PbZr(0.53)Ti(0.47)O(3)](1 - x) (PFW(x)-PZT(1 - x), x = 0.2 and 0.3) by means of broad-band dielectric spectroscopy, differential scanning calorimetry and SQUID magnetometry. We did not confirm the observations of Kumar et al (2009 J. Phys.: Condens. Matter 21 382204), who reported on reversible suppression of ferroelectric polarization in polycrystalline PFW(x)-PZT(1 - x) thin films for magnetic fields above 0.5 T. We did not observe any change of ferroelectric polarization with external magnetic fields up to 3.2 T. Pirc et al (2009 Phys. Rev. B 79 214114) developed a theory explaining the reported large magnetoelectric effect in PFW(x)-PZT(1 - x), taking into account relaxor magnetic and relaxor ferroelectric properties of the system. Our data revealed classical ferroelectric properties below 525 K and 485 K in samples with x = 0.2 and 0.3, respectively. Moreover, paramagnetic behavior was observed down to 4.5 K instead of previously reported relaxor magnetic behavior. It seems that the reported switching-off of ferroelectric polarization in PFW(x)-PZT(1 - x) thin films is not an intrinsic property, but probably an effect of electrodes, interlayers, grain boundaries or second phases presented in polycrystalline thin films.

  13. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2014-01-01

    Cue Rondo is an open composition to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound/video files will in some cases only provide a few minutes' sample, or the visuals will not appear at all....... Please DOWNLOAD them to see/hear them in full length! This work is licensed under a Creative Commons "by-nc" License. You may for non-commercial purposes use and distribute it, performance instructions as well as specially designated recordings, as long as the author is mentioned. Please see http...

  14. Impact localization on composite structures using time difference and MUSIC approach

    Science.gov (United States)

    Zhong, Yongteng; Xiang, Jiawei

    2017-05-01

    1-D uniform linear array (ULA) has the shortcoming of the half-plane mirror effect, which does not allow discriminating between a target placed above the array and a target placed below the array. This paper presents time difference (TD) and multiple signal classification (MUSIC) based omni-directional impact localization on a large stiffened composite structure using improved linear array, which is able to perform omni-directional 360° localization. This array contains 2M+3 PZT sensors, where 2M+1 PZT sensors are arranged as a uniform linear array, and the other two PZT sensors are placed above and below the array. Firstly, the arrival times of impact signals observed by the other two sensors are determined using the wavelet transform. Compared with each other, the direction range of impact source can be decided in general, 0°to 180° or 180°to 360°. And then, two dimensional multiple signal classification (2D-MUSIC) based spatial spectrum formula using the uniform linear array is applied for impact localization by the general direction range. When the arrival times of impact signals observed by upper PZT is equal to that of lower PZT, the direction can be located in x axis (0°or 180°). And time difference based MUSIC method is present to locate impact position. To verify the proposed approach, the proposed approach is applied to a composite structure. The localization results are in good agreement with the actual impact occurring positions.

  15. An In Situ Electric Field Study of Magnetoelectric Coupling in PZT-LSMO Thin Film Heterostructures Using Polarized Neutron Reflectometry and Transmission Electron Microscopy

    Science.gov (United States)

    Spurgeon, Steven; Sloppy, Jennifer; Huang, Esther; Vasudevan, Rama; Lofland, Samuel; Lauter, Valeria; Valanoor, Nagarajan; Taheri, Mitra

    2013-03-01

    The development of ``spintronics'' devices based on charge and spin transport has signaled a paradigm shift in the design of data storage and computing technologies. Magnetoelectric materials, which exhibit intrinsic coupling between electronic and magnetic order, are ideal for these applications. Unfortunately, single-phase magnetoelectrics are exceedingly rare in nature and attention has turned to composite heterostructures that display coupled functionalities at interfaces. A promising system in which to explore this coupling is a thin film oxide heterostructure of the piezoelectric Pb(Zr0.2Ti0.8)O3 (PZT) and the half-metal La0.7Sr0.3MnO3 (LSMO). We show that it is possible to construct a capacitor-type device structure from these materials that may form the basis for an electrically-switched magnetic memory. We conduct polarized neutron reflectometry (PNR) measurements and measure changes in the magnetization depth profile throughout the composite under the reversal of an in situ electric field. We then correlate these PNR results to local strain and chemistry using transmission electron microscopy (TEM). We find that a combination of charge doping and strain mechanisms governs coupling in this system.

  16. Effects of Al2O3 Particulates on the Thickness of Reaction Layer of Al2O3 Joints Brazed with Al2O3-Particulate-Contained Composite Filler Materials

    Institute of Scientific and Technical Information of China (English)

    Jianguo YANG; Jingwei WU; Hongyuan FANG

    2003-01-01

    In order to understand the rate-controlling process for the interfacial layer growth of brazing joints brazed with activecomposite filler materials, the thickness of brazing joints brazed with conventional active filler metal and activecomposite filler materials with different volume fraction of Al2O3 particulate was studied. The experimental resultsindicate although there are Al2O3 particulates added into active filler metals, the time dependence of interfacial layergrowth is t2 as described by Fickian law for the joints brazed with conventional active filler metal. It also shows thatthe key factor affecting the interfacial layer growth is the volume fraction of alumina in the composite filler materialcompared with the titanium weight fraction in the filler material.

  17. Synthesis of thick mesoporous gamma-alumina films, loading of Pt nanoparticles, and use of the composite film as a reusable catalyst.

    Science.gov (United States)

    Dandapat, Anirban; Jana, Debrina; De, Goutam

    2009-04-01

    Nanocrystalline mesoporous gamma-Al2O3 film of high thickness has been developed and characterized. The films were prepared on ordinary glass substrates by a single dip-coating method using boehmite (AlOOH) sols derived from aluminum tri-sec-butoxide in presence of cetyltrimethylammonium bromide (CTAB) as structure-directing agent. The dried films were heat-treated at 500 degrees C in air to remove the organics and strengthen the network. The GIXRD of the heat-treated (500 degrees C) film shows a broad peak in the low-angle region supporting the formation of worm-hole-like disordered mesostructures. The high-angle GIXRD, FTIR, and TEM of the films confirm the formation of gamma-Al2O3. N2 adsorption-desorption analyses showed that the heat-treated (500 degrees C) film has a BET surface area of 171 m(2) g(-1) with a pore volume of 0.188 cm(3) g(-1) and mean pore diameter 4.3 nm. Pt nanoparticles (NPs) (approximately 2.7 mol % with respect to the equivalent AlO(1.5)) were generated inside the mesopores of the heat-treated films simply by soaking H2PtCl6 solutions into it, and followed by thermal decomposition at 500 degrees C. The surface area and pore volume of the Pt-incorporated film have been reduced to 101 m(2) g(-1) and 0.119 cm(3) g(-1) respectively, confirming the inclusion of Pt NPs inside the pores. FESEM and TEM studies revealed uniform distribution of Pt NPs (2-8.5 nm; average diameter 4.9 nm) in the films. Catalytic properties of the Pt-incorporated films were investigated in two model (one inorganic and other organic) systems: reduction of hexacyanoferrate(III) ions by thiosulfate to ferrocyanide, and p-nitrophenol to p-aminophenol. In both the cases, the catalyst showed excellent activities, and the reduction reactions followed smoothly, showing isosbestic points in the UV-visible spectra. The catalyst films can be separated easily after the reactions and reused several times.

  18. Ferroelectric and Piezoelectric Properties of 0.72Pb(Zr0.47Ti0.53)O3-0.28Pb[(Zn0.45Ni0.55)1/3Nb2/3]O3 Thick Films for Energy Harvesting Device Application

    Science.gov (United States)

    Jeong, Young Hun; Kim, Kyoung Bum; Lee, Young-Jin; Cho, Jeong-Ho; Kim, Byoung-Ik; Paik, Jong-Hoo; Nahm, Sahn

    2012-09-01

    The Ferroelectric and piezoelectric properties of 0.72Pb(Zr0.47Ti0.53)O3-0.28Pb[(Zn0.45Ni0.55)1/3Nb2/3]O3 (PZT-PZNN) piezoelectric thick films were investigated for application to energy harvesting devices. The PZT-PZNN thick films were fabricated by a conventional tape casting process. The sintered PZT-PZNN thick film was highly dense and flat when the annealed temperature was 1100 °C. It exhibited substantial ferroelectric and piezoelectric properties of Pr = 20.6 µC/cm2, d33 = 370 pC/N, ɛT33/ɛ0 = 1185, and kp = 0.44. Moreover, its d33·g33, which can characterize high energy density material, is as large as approximately 13050×10-15 m2/N. Therefore, the PZT-PZNN thick film can be a potential piezoelectric material for application to energy harvesting devices.

  19. Electrochemical impedance analysis of electrodeposited Si-O-C composite thick film on Cu microcones-arrayed current collector for lithium ion battery anode

    Science.gov (United States)

    Hang, Tao; Mukoyama, Daikichi; Nara, Hiroki; Yokoshima, Tokihiko; Momma, Toshiyuki; Li, Ming; Osaka, Tetsuya

    2014-06-01

    The impedance behaviors of Si-O-C composite film electrodeposited on Cu microcones-arrayed current collector have been investigated to understand the electrochemical process kinetics that influences the cycling performance when used as a highly-durable anode in a lithium battery. The impedance was measured by using impedance spectroscopy in equilibrium conditions at various depths of discharge and during several hundred charge-discharge cycles. The measured impedance was interpreted with an equivalent circuit composed of solid electrolyte interphase (SEI) film, charge transfer and solid state diffusion. The impedance analysis shows that the change of charge transfer resistance is the main contribution to the total resistance change during discharge, but an abrupt augmentation of diffusive resistance at high depth of discharge is also observed which cannot be explained very well by the presented model. The impedance evolution of this electrode during charge-discharge cycles suggests that the slow growth of the SEI film as well as the increase of the electrode density are responsible for the capacity fading after long term cycling.

  20. Piezoelectric and dielectric properties of Cr-doped PSN-PZN-PZT quaternary piezoelectric ceramics

    Institute of Scientific and Technical Information of China (English)

    SUN Qingchi; WANG Lifeng; LIU Ping; NIE Qiang

    2005-01-01

    PSN-PZN-PZT + x wt.%Cr2O3, x = 0.0-0.9, were prepared by conventional mixed oxide techniques at sintering temperatures of 1220℃-1300℃ for 2 h. The effect of sintering temperature on the microstructure and the piezoelectric properties was investigated by XRD, SEM, and other conventional measurement. The result indicated that with temperature increasing, the valence of Cr ion from Cr5+ or Cr6+ changes into Cr3+, and the piezoelectric properties turn hard. With increasing Cr2O3 content, the amount of rhombohedral phases increases and the morphotropic boundary phase is correspondingly shifts to rhombohedral phase. A uniform microstructure and excellent comprehensive properties were obtained at 1240C as the amount of Cr2O3 is 0.5 wt.%.