The Experimental Study Of Mechanics Characteristics In Acoustic Streaming

Acoustic tweezers can manipulate and filter particles like cells. Under the control of acoustic tweezers, particles can be arranged in the orbits when their parameters are set. Acoustic tweezers can select and manipulate cells and particles effectively, regardless of their shapes, sizes or electrical properties. As the energy density of acoustic tweezers is far lower than that of optical tweezers, it will not hurt living cells, and acoustic tweezers have the advantages of simple structure, small volume, low costs, multi-functional and non-contact operation characters which gives acoustic tweezers good biocompatibility. These advantages will ensure acoustic tweezers make an important role in materials, biology, medical research and other fields. In this paper, we developed the interdigital transducers of 20 MHz to manipulate water soluble silicone oil droplets and fluorescence polystyrene particles. We studied the function of surface plane wave and surface standing wave on the droplets and the polystyrene particles respectively. As a result, the polystyrene particles are successfully trapped in the nodal positions, and the four-quadrant acoustic streaming patterns are observed, verifying the existence of Rayleigh acoustic streaming. Furthermore, we measured the force of acoustic streaming acting on the plate and concluded the relationship between the function of acoustic streaming and the power of signal applied to the acoustic tweezers.