Smart Materials

Volumes 55-57

doi: 10.4028/www.scientific.net/AMR.55-57

Paper Title Page

Authors: K. Uchino
Abstract: 2008 marks the 30th year after the piezo-actuator boom started. The basic required technologies seem to be maturing and a drastic cost reduction period started. It is time to review the development history, analyze the present problems, and find the strategies to move forward to wide commercialization of the piezo actuator, as the key electro-mechanical component in the 21st century. This paper is Part II of the review paper “Piezoelectric Actuators 2006” presented previously [1], which covered various application areas of actuators, from information technology/robotics, bio- and medical engineering, to ecological and energy technologies. If the reader has not read this article, it is recommended to so first.
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Authors: R.P. Tandon
Abstract: Use of smart intelligent materials is gaining great prominence in the domain of underwater acoustics, defense and environmental engineering. Piezoelectric ceramics such as PZT have found applications in MEM hydrophones to high power sonars. These are also finding widespread use in active noise cancellation in the industrial applications. This paper will cover these topics and also use of ER fluids and shape memory alloys will be reviewed. This will be followed by the authors own contribution made for the field of piezo-composites for the applications in hydrophones and other underwater devices
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Authors: Jeremie Barrel, Eugene Stytsenko, Massimo Viviani, Kenneth MacKenzie
Abstract: Compositionally graded Ba(1-x)SrxTiO3 thick films were fabricated by the airflow deposition technique. Films displayed hysteresis translation along the polarization axis when driven by an alternating electric field. The trend of the hysteresis shift as a function of temperature is similar to the difference of DC currents measured when a positive and negative DC electric field is applied. The study suggests that the origin of this phenomenon lies in an asymmetry of the film conductance due to the presence of asymmetric Schottky contacts at the BaTiO3/Ag and Ag/Ba0.xSr1-0.xTiO3 interfaces.
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Authors: R. Stevens, D. Regonini, Chris R. Bowen, Angkhana Jaroenworaluck
Abstract: Titanium oxide (TiO2) nanopowders can be reproducibly formed by hydroxylation of titanium organic complexes. The crystallisation to anatase and rutile can be controlled by systematic calcination and a complex range of properties optimized for specific applications. Characterisation of the powders has been undertaken using advanced physical techniques. The morphology of the TiO2 powders is determined by solution concentration and precipitation phenomena, particularly temperature and stirring regime. However the fine powders have limitations in terms of processing flexibility particularly when nanostructured and organised features are desired, due to their fine particle structure and inability to be sintered without undergoing complete phase change. Anodising titanium metal can overcome these difficulties and under appropriate conditions semi-ordered nanotubes of TiO2 have been prepared. These can be heat treated to develop the phase of choice, anatase or rutile. A mechanism for the formation of the nanotubes has been proposed which is based on the linkage of pores developed in the anodized oxidation product. The pores are driven to into alignment by the applied potential and link up to form the tubular structures. A degree of control of the tube size and wall thickness is shown possible by control of applied voltage. The nanotubes have been investigated using SEM, TEM, XRD and Raman spectroscopy to elucidate the structure and postulate the formation mechanism.
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Authors: N.X. Phuc, N.A. Tuan, N.C. Thuan, V.A. Tuan, L.V. Hong
Abstract: Titanium oxide (TiO2) nanopowders can be reproducibly formed by hydroxylation of titanium organic complexes. The crystallisation to anatase and rutile can be controlled by systematic calcination and a complex range of properties optimized for specific applications. Characterisation of the powders has been undertaken using advanced physical techniques. The morphology of the TiO2 powders is determined by solution concentration and precipitation phenomena, particularly temperature and stirring regime. However the fine powders have limitations in terms of processing flexibility particularly when nanostructured and organised features are desired, due to their fine particle structure and inability to be sintered without undergoing complete phase change. Anodising titanium metal can overcome these difficulties and under appropriate conditions semi-ordered nanotubes of TiO2 have been prepared. These can be heat treated to develop the phase of choice, anatase or rutile. A mechanism for the formation of the nanotubes has been proposed which is based on the linkage of pores developed in the anodized oxidation product. The pores are driven to into alignment by the applied potential and link up to form the tubular structures. A degree of control of the tube size and wall thickness is shown possible by control of applied voltage. The nanotubes have been investigated using SEM, TEM, XRD and Raman spectroscopy to elucidate the structure and postulate the formation mechanism.
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Authors: G.R. Mitchell, M. Belal, F.J. Davis, D.E. Elliott, M. Kariduraganavar, S.D. Mohan, R.H. Olley, Sujat Sen
Abstract: We use a combination of microscopy, x-ray scattering and neutron scattering to show how structure develops in micro and nano-size polymer fibres prepared by electrospinning. The technique has been applied to a range of different polymers, an amorphous system (polystyrene), a crystallisable polymer (poly-ε-caprolactone), a composite systems (polyethylene oxide or poly vinyl alcohol containing polypyrrole) and consider the possibility of self assembly (gelatin).
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Authors: A. Rujiwatra, N. Thammajak, Y. Chimupala, Pitak Laoratanakul
Abstract: The so-called sonocatalyzed ammonothermal technique has been developed for the preparation of lithium niobate fine powders from commercially as-received niobium pentoxide and lithium nitrate. The present work shows that the application of ultrasonic activation prior to the ammonothermal treatment can produce a single phase lithium niobate fine powder at a relatively low temperature of 220°C. The influences of Li-precursors, ammonia solution concentration, reaction temperature and time, as well as Li:Nb mole ratio - which is evidentially the most critical factor promoting a single phase formation - are discussed.
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Authors: S.K. Asl, S.K. Asl
Abstract: The PZT-based ceramics with a composition of Pb1.1-sRs (Zr0.53Ti0.47)O3.1+0.5s; s = 0.00 – 0.02, R= La, Nd, Sm were prepared by conventional mixed-oxide, and sol-gel methods, with optimal preparation conditions. The microstructural and electrical properties were examined as a function of the additive content and type then compared. Microstructural and compositional analyses of the PZT-based ceramics have been carried out using SEM and XRD. Dielectric properties of the samples were measured with an impedance analyzer. The ferroelectric properties of the PRZT samples were measured using the frequencies. It showed that the La additive improved both the dielectric and piezoelectric properties. Using sol gel method decreased saturation point of PZT. The PRZT with 0.5 mol% La be in optimum condition
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