Building the isotropic acoustic potential well with strong constraint boundary to improve the stability of ultrasonic transportation

A quantitative analysis of the acoustic potential well has been proposed for the purpose of realizing stability improvement of ultrasonic transportation. It was found that the boundary R p and elastic constant k_l (l, θ) of the acoustic potential well, acoustic radiation force offset ratio β_fl, and elastic constant offset ratio β_kl are the critical parameters that define the trapping ability. They were made clear both their intrinsic significance. The stability of the ultrasonic transportation using three transducers is theoretically studied. Long range ultrasonic transportation of silica beads with better stability is realized by optimizing the acoustic parameters to get the well-defined acoustic potential wells. No slip-off the equilibrium position has been observed, which proved its strong ability of trapping and transportation. Because of its simplicity, flexibility, and non-destructivity, the ultrasonic transportation offered a competitive micro-manipulation technology and will provide a promising tool for life science, chemistry and micro-assembly.