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Electroacoustic transducers

Chemical and physical processing techniques for ferroelectric thin films have undergone explosive advancement in the past few years (see Ref. 1, for example). The use of PZT (PbZri- cTi c03) family ferroelectrics in the nonvolatile and dynamic random access memory applications present potentially large markets [2]. Other thin-film devices based on a wide variety of ferroelectrics have also been explored. These include multilayer thin-film capacitors [3], piezoelectric or electroacoustic transducer and piezoelectric actuators [4-6], piezoelectric ultrasonic micromotors [7], high-frequency surface acoustic devices [8,9], pyroelectric intrared (IR) detectors [10-12], ferroelectric/photoconduc-tive displays [13], electrooptic waveguide devices or optical modulators [14], and ferroelectric gate and metal/insulator/semiconductor transistor (MIST) devices [15,16]. [Pg.481]

The rise in importance of this method results from the high accmacy with which the speed of sound can now be measured from the spherical modes of a spherical resonator, and the fact that the results are not subject to errors from gas adsorption. One form of apparatus [89-ewi/tru] is shown schematically in Figme 8. The sealed resonator is constracted from two hemispheres of aluminium alloy, mounted on a copper support. It has two ports machined at an angle of 90° to take the electroacoustic transducers. [Pg.8]

I started my scientific career in Sony as a researcher on zinc-air hatteries. After 8 years of R D on electrochemistry, my research field was shifted against my will to electroacoustic materials, specifically materials for diaphragms of electroacoustic transducers including loud speakers, headphones, and microphones. [Pg.23]

The advantages of using ferroelectric polymeric materials for industrial applications such as pyroelectric detectors and ultrasonic and electroacoustic transducers lies in the ability to generate very thin films with a fast response time. [Pg.1217]

First system of piezoelectric ceramics (BaTiOs) has been developed at the end of World War II independently by the researchers in Japan, Soviet Union and USA. Ceramic material has been utilized for the applications in ultrasound (electroacoustic) transducers. Later in 1950 s the most important ceramic system ever - i.e. [Pg.152]

Ionizing radiation (5.3.11) This is generated, for example, by X-ray tubes, and radioactive substances can ignite explosive atmospheres (especially explosive atmospheres with dust particles) as a result of energy absorption. Ultrasonic (5.3.12) In the use of ultrasonic sound waves, a large proportion of the energy emitted by the electroacoustic transducer is absorbed by solid or liquid substances. As a result, the substance exposed to ultrasonic sound waves warms up so that, in extreme cases, ignition may be induced. [Pg.746]

Vullers R et al (2009) Micropower energy harvesting. Solid-State Electron 53 684-693 Yasuno Y, Riko Y (1999) An approach to integrated electret electroacoustic transducer -Experimental digital microphone, fit Proceedings of the 10th international symposium on electret (ISEIO), Athens, pp 727-730... [Pg.644]

Such polymers as PVDF, in particular, have wide applications [3] sometimes its properties are advantageous for some reasons, e.g., low electric permittivity and small thickness, but limit ite application in other devices. When, for example, hydrophones, which are electroacoustic transducers used in a water environment, b use of the low transducer capacity made of PVDF, amplifiers should be placed very near. Moreover, vduge sensitivity in the open system given in dB in the relation 1/piPa determined by a product giz, (where g indicates hydrostatic piezoelectric voltage coefficient and Xj is transducer thickness), is low for transducers m of PVDF films. [Pg.580]

H. Naono. T. Goloh. M. Malsumoto. and S. Ibaraki, Design of an electroacoustic transducer using piezoelectric polymer film. Preprint of 58th AES Com., p. 1271, 1977. [Pg.729]

Nakai T, Sugano Y, Shoda M, Sakakibara H, Oiwa K, Tsuzi S, Imai T, Sugiyama J, Takeuchi M, Yamauchi D, Mineyuki Y (2013) Formation of highly twisted ribbons in a carboxymethyl cellulose gene-disrupted strain of a cellulose-producing bacterium. J Bacteriol 195 958-964 Nieduszy I, Preston RD (1970) Crystallite size in natural cellulose. Nature (Lond) 225 273-275 Nishi Y, Uryu M, Yamanaka S, Watanabe K, Kitamura N, Iguchi M, Mitsuhashi S (1990) The structure and mechanical properties of sheets prepared from bacterial cellulose. 2. Improvement of the mechanical properties of sheets and their applicability to diagrams of electroacoustic transducers. J Mater Sci 25 2997-3001... [Pg.317]

Bizet K., Gabrielli C., Perrot H., and Therasse J., Validation of antibody-based recognition by piezoelectric transducers through electroacoustic admittance analysis. Biosens. Bioelectron., 13(3-4), 259-269, 1998. [Pg.228]

The DT-1200 has two separate sensors for measuring acoustic and electroacoustic signals separately. Both sensors use the pulse technique. The acoustic sensor has two piezo crystal transducers. The gap between the transmitter and receiver is variable in steps. In default mode, the gap changes from 0.15 mm up to 20 mm in 21 steps. The basic frequency of the pulse changes in steps as well. In default mode, the frequency changes from 3 to 100 MHz in 18 steps. The number of pulses collected for each gap and frequency is automatically adjustable in order to reach the target signal-to-noise ratio. [Pg.192]

The actual power density achieved, for a particular loading condition, is proportional to the product of the electrical power consumed and the mechanical resistance of the medium. As a consequence, when a change occurs in the load (e.g., the density, viscosity, homogeneity of the medium), the amplitude of the vibration must change if the power is to remain constant. The second is the optimization of the electroacoustic efficiency by electronic matching between the transducer assembly and the generator imder the ideal amplitude conditions. [Pg.309]

A surface acoustic wave (SAW), also called a Rayleigh wave, is essentially a coupling between longitudinal and shear waves. The energy carried by the SAW is confined near the surface. An associated electrostatic wave exists for a SAW on a piezoelectric substrate, which allows electroacoustic coupling via a transducer. The advantages of SAW technology are 23, 24] ... [Pg.129]

Another method for the determination of electrophoretic mobility which has emerged in recent years is that of the measurement of the electrokinetic sonic amplitude (ESA) for a particle subjected to an alternating current (8). This electroacoustic effect is a result of the oscillation of the particles near the electrodes where a sound wave is produced that can be picked up by a pressure transducer located behind the electrode. The ESA pressure signal is simultaneously proportional to the dynamic mobility of the particle, the particle volume fraction and the density difference between particle and solvent. Thus, the electroacoustic effect is appropriate for concentrated dispersions where conventional electrophoretic methods are inappropriate. However, one disadvantage of the method is that it is not appropriate to systems having low density differences between the particles and suspending liquid. [Pg.379]

The piezoelectric effect enables the transformation of a force or a deformation into electrical signals and vice versa. Applications are numerous in electroacoustics, like ultrasonic microphones and transducers, in telecommunications, like filters and timers, in metrology like measurements of forces and displacements and in the field of electrical appliances, the standard example being the gas lighter. [Pg.469]


See other pages where Electroacoustic transducers is mentioned: [Pg.183]    [Pg.219]    [Pg.830]    [Pg.457]    [Pg.5693]    [Pg.11]    [Pg.705]    [Pg.706]    [Pg.706]    [Pg.183]    [Pg.219]    [Pg.830]    [Pg.457]    [Pg.5693]    [Pg.11]    [Pg.705]    [Pg.706]    [Pg.706]    [Pg.820]    [Pg.112]    [Pg.90]    [Pg.108]    [Pg.379]    [Pg.170]    [Pg.37]    [Pg.158]    [Pg.8]    [Pg.22]    [Pg.1549]   
See also in sourсe #XX -- [ Pg.706 ]




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