Acoustic streaming

Acoustic streaming is the generation of a steady flow in a liquid or gas driven by sound waves, typically high-frequency ultrasound. The effect results from nonlinear interactions between the acoustic wave and the fluid, wherein the momentum of the oscillating sound field is transferred to the medium, creating localized or bulk fluid motion[1][3][5]. Acoustic streaming is commonly observed in microfluidic devices and acoustofluidics, where it is used for manipulating particles, mixing fluids, and controlling cell or molecular movement in laboratory and biomedical applications[5][6][8][9]. There are several subtypes, most notably "Eckart streaming" (bulk-driven, due to sound attenuation in the fluid's interior) and "Rayleigh streaming" (boundary-driven, due to interactions at boundaries or walls)[3][5]. The phenomenon is described by nonlinear hydrodynamics (Navier-Stokes equations) and is a core principle in many scientific and industrial applications, but it is not a definable drug, protein, gene, receptor, or transporter.

Other names

acoustically induced flowEckart streamingRayleigh streaming