Formation of two-way Lamb waves and force potential wells using single conventional ultrasonic transducer

Abstract

A new method is introduced that uses single conventional ultrasonic transducer and a sheep horn shaped metal piece to induce two-way Lamb waves, and furthermore collects leaky Lamb waves to form two force potential wells. The immersion acoustical measurements show that the two-way Lamb waves with adjustable amplitudes can be induced when a 1MHz transducer radiates ultrasonic waves on to the semicircle of a metal "sheep horn". Furthermore, the results obtained by hydrophone measurement and fluorescence microscope observation verify that the force potential well can be formed in the circle of metal "sheep horn" by the leaky Lamb wave of each way and possibly used to collect the submicro particles. This designed method is intended to provide assistance in limited space for microscope observing by collecting particles within low force potential well. All experiment results also indicate that radiation force and the gradient of force potential well produced by this leaky Lamb wave device is very small due to several reasons including low generation efficiency at semicircle tip and propagation attenuation of Lamb wave in metal piece, near field properties of leaky Lamb wave in liquid, and so on. © 2012 Acoustical Society of America.