Estudo da geração de feixes de ultrassom por holograma acústico

Abstract

Ultrasound beams are used in imaging techniques applied to biomedicine and nondestructive testing. Recently, ultrasound has been used in methods of manipulating droplets and biological cells through levitators and acoustic clamps. In these techniques there is a chance to generate ultrasound beams with specificities for each application. A holographic element, coupled to a piezoelectric transducer, stores amplitude information The phase of an ultrasound beam is propagated in a plane or solid. You can virtually generate an arbitrary beam, provided an amplitude information and an arrangement present in the hologram. From the adapted IASA angular spectrum method, we determined holograms capable of generating propagating beams (zero order Bessel beam), with an angular momentum (Bessel beam of order one) and spherically focused. The beam is specified in a 50 x 50 mm transverse image plane at a distance of 30 mm from the transducer, the features projected by the hologram are in excellent agreement with the formula specified in the image plane.