Topic
Acoustic interferometer
About: Acoustic interferometer is a research topic. Over the lifetime, 1493 publications have been published within this topic receiving 19355 citations.
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18 Sep 2005
TL;DR: In this paper, a new way to eject droplets (water, ink, etc.) using surface acoustic wave (SAW) devices was described, where the Rayleigh waves were excited using classical inter-digital transducers (IDT).
Abstract: The present study aims to investigate droplet ejection using Surface Acoustic Waves (SAW). The interests in droplet ejection microsystems have dramatically grown in recent years due to inkjet printhead demand (Drop-On-Demand). Among several actuating methods (thermal, piezoelectric, etc.), the thermally driven inkjet printhead is the most successful (low cost, easy fabrication and high printing quality). Almost all of the current ink jet printers eject ink droplets through nozzles, with a direction of ejection always perpendicular to the nozzle surface. Surface acoustic waves devices are widely used for frequency filtering and are mainly devoted to cellular phones and telecommunication handset. Nowadays, recently published works have demonstrated the interest of SAW for guiding and positioning small liquid droplet atop a flat surface. This paper describes a new way to eject droplets (water, ink, etc...) using SAW. The surface acoustic waves devices used to eject droplets are carried out on lithium niobate substrates (LiNbO3 cut Y+128°, X propagation). The Rayleigh waves are excited using classical inter-digital transducers (IDT). The design of IDT has been simulated with finite element analysis and boundary element methods. The computations on the design of the IDT have been compared with measurements. The vibration amplitude of the wave necessary to droplet ejection is measured using a heterodyne laser probe. The range of the droplets volume ejected is between 100nl and 1μl. The influence of the supply voltage on the ejection is described.
6 citations
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20 Jan 1978
TL;DR: In this paper, a correlator is provided to judge the presence or not of any flaw of the position to be examined from the correlations of respective receiving acoustic waves by providing a correlation which judges the correlations from the propagation acoustic waves from a piezoelectric pulser.
Abstract: PURPOSE: To judge the presence or not of any flaw of the position to be examined from the correlations of respective receiving acoustic waves by providing a correlator which judges the correlations from the propagation acoustic waves from a piezoelectric pulser. CONSTITUTION: A piezoelectric pulser 2 is excited by the signal having amplified the output of an oscillator 5 with a power amplifier 6 and generates impulsive acoustic waves. The acoustic waves propagate in the member to be examined 1. Pizoelectric sensors 3, 4 are subsequently arrayed in the propagating direction of said acoustic waves and the acoustic waves are received respectively thereby. The receiving timings thereof vary with the time differences required for propagation of the acoustic wave in the member to be examined 1. And the signal having been received in the first piezoelectric sensor 3 is supplied to one terminal of a correlator 10. The signal having been received in the second piezoelectric sensor 4 is being inputted to the other terminal of the correlator 10. COPYRIGHT: (C)1979,JPO&Japio
6 citations
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TL;DR: In this paper, the attenuation of shear and longitudinal waves in natural and synthetic crystal quartz was investigated at low temperatures and it was shown that attenuation is nearly proportional to frequency over the temperature-range investigated.
Abstract: THE temperature-dependent part of the ultra-sonic attenuation in single crystal quartz at frequencies in the range 600–1,200 Mc/s has been investigated at low temperatures. Fig. 1 refers to measurements in natural quartz for longitudinal waves and Fig. 2 shows the attenuation of shear waves travelling in the AC-direction. Fig. 3 is a comparison of the attenuations of 1,100-Mc/s shear waves in natural and synthetic crystals. Both for shear and longitudinal waves the attenuation is found to be nearly proportional to frequency over the temperature-range investigated. Below about 20° K the attenuation of both shear and longitudinal waves in synthetic quartz is substantially greater than in natural quartz. It is also found (Fig. 1) that the attenuation of longitudinal waves in two natural quartz samples of different sizes are identical, to within the experimental error, indicating that the size-dependent thermal conductivity is not a significant parameter.
6 citations
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TL;DR: In this article, the fundamental principles of the interferometer were incorporated in an instrument in which the liquid under examination may be put under pressures up to about 10,000 lb/sq. in.
Abstract: The fundamental principles of the interferometer, particularly the liquid supersonic interferometer of Hubbard and Loomis, are incorporated in an instrument in which the liquid under examination may be put under pressures up to about 10,000 lb./sq. in. The instrument and the pressure device are built into a block of special cast steel 8×5×4½ inches. The results given are preliminary and merely show the performance and precision of the instrument. A curve is given showing the change of velocity of a high frequency acoustic wave of 195 kc from 1143 meters per second at atmospheric pressure to 1233 meters per second at a pressure of 3105 lb./sq. in. in carbon disulphide at room temperature. (The room temperature varied at different readings from 22.25°C to 25.41°C.)
6 citations
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TL;DR: In this paper, a method and system for acoustic treatment performance testing in a free-ld acoustic environment is provided. Butler et al. measured the acoustic pressure of the gated acoustic pulse and reflected energy from a location approximately in-line with the source and the acoustic treatment.
Abstract: A method and system for acoustic treatment performance testing in a free-ld acoustic environment is provided. A sound source directs a gated acoustic pulse at an acoustic treatment. Acoustic pressures of the gated acoustic pulse and reflected energy from the acoustic treatment are measured from a location approximately in-line with the source and the acoustic treatment. This measurement location is at least one-half the wavelength of the frequency of interest away from the source and is at least a distance equal to (t*c/2) away from the acoustic treatment where t is equal to the duration of the gated acoustic pulse and c is equal to the speed of sound in the free-field acoustic environment. The acoustic pressures of the gated acoustic pulse and reflected energy are compared as an indication of performance of the acoustic treatment at a frequency of interest.
6 citations