Resumo

BOULLOSA, R. R.; PEREZ-LOPEZ, A.  e  DORANTES-ESCAMILLA, R.. An Ultrasonic Levitator. J. appl. res. technol [online]. 2013, vol.11, n.6, pp.857-865. ISSN 2448-6736.

We report the development of an ultrasonic levitation system. Liquid drops or solid samples of diameter less than one half wavelength of the excitation frequency are levitated without contact just below the pressure nodes. The piezo transducer is excited by an ultrasonic signal of around 29 kHz through a voltage amplifier. The choice of the number of half-waves of the acoustic field in the space between the reflector and radiator is made by means of a micrometer. A lamp, an amplifier and a frequency generator are integrated to the levitator. The diameters of the droplets of liquid that can levitate are of the order of tenths of mm to 3 or 4 mm, depending on the liquid properties (density, surface tension, etc.). Solid objects can also be levitated. The maximum voltage of the system is 20 V_rms.

Palavras-chave : radiation pressure; acoustic levitation; levitator.

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