Gap Distance Between Pearl Chains in Acoustic Manipulation

• We present a theory to compute the stable gap (interparticle) distance between particle chains collected in the pressure node of an acoustic standing wave. The primary and secondary acoustic radiation forces are the two competing forces that act on the particles during the particle chain formation. The stable equilibrium distance between two chains is reached when both forces are in balance. Most interestingly, the density scattering coefficient appears to the second power in the theoretical prediction of the gap distance, indicating that the particle-chain formation occurs for both particles heavier than the surrounding medium and, notably, also for buoyant particles. Experimentally, the gap distance is evaluated for several different media and particle material combinations and the particle-chain formation is observed for both buoyantparticles and particles heavier than the surrounding medium. The theory agrees well with experiments in the cases where the material properties of the medium and the particles are well known.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Strömningsmekanik och akustik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Fluid Mechanics and Acoustics (hsv//eng)

Publication and Content Type

art (subject category)

ref (subject category)