Acousto-Microfluidic Probe for Fluid and Particle Manipulation

This paper presents a novel Acousto-Microfluidic Probe (AcouMFP) for fluid and particle manipulation within an open microfluidic system, which integrates the interaction of Bulk Acoustic Waves with hydrodynamic flow confinement (HFC) to perform multiple operations within a single device. The probe comprises a single central injection part, two crescent-shaped aspiration ports, and numerous triangular posts protruding on its mesa region. A piezoelectric transducer attached to the probe uses the piezoelectric effect to induce acoustic forces on the fluids and particles within the HFC and achieve the counter-rotating vortices of the fluid and the dynamic trapping of microparticles at relatively high flow rates. A two-dimensional numerical study is also carried out to capture the interaction of the acoustic waves and the HFC, and a close agreement with experiments is observed.