Numerical and experimental studies of acoustic streaming effects on microparticles/droplets in microchannel flow

A star shaped acoustofluidic mixer enhances rapid malaria diagnostics via cell lysis and whole blood homogenisation in 2 seconds

“…In other words, at a fixed power input (3 W), decreasing the flow rate increases the impact of acoustic streaming effect on the lysis process. 22 This results in a smaller fluid damping effect on the oscillating disk, thus, a stronger streaming velocity is generated leading to higher shear stress exerted on the fluid and more cells are prone to be lysed. 17 Additionally, at higher shear rates, RBCs tend to align with the shear plane and spin with respect to their axis while showing a tank-treading motion.…”

“…In the former, piezoelectric substrate patterned with interdigitated transducers generate a travelling acoustic wave on the surface of the substrate, which leaks and attenuates in the fluid medium. 21,22 In case of the latter, acoustic streaming can typically be generated upon contact of fluid with an oscillating solid microstructure. The small perturbations induced by these rapid oscillations result in a body force in the fluid, known as the Reynolds stress.…”

Ultrasonic surface acoustic wave-assisted separation of microscale droplets with varying acoustic impedance

“…The acoustic beamwidth ( w 0 ) of the Gaussian-profile SAWs produced by the SFIT was carefully designed as w 0 = 101.26 μm so that droplet diameter was comparable to the beamwidth for the droplets to experience the ARF effectively [33] . The standard interdigital transducer with parallel electrode fingers with the same effective acoustic beamwidth can be also used as an alternative [34] . The Rayleigh-type SAWs, propagating on the piezoelectric substrate, refracted into the fluid domain within the microchannel in the form of longitudinal waves (LWs) at the Rayleigh angle.…”

Acoustophoretic trapping of particles by bubbles in microfluidics

“…This force tends to come out of the center of the bubble and affects the particles that are present within the flow field. It is generally assumed that the particles absorb this scattered radiation acquiring part of the momentum transferred [45].…”

“…The adherence of particles on the bubble's membrane is due to the generated acoustic streaming around the bubble. Maramizonouv et al Frontiers in Physics frontiersin.org presented a study in 2021 [45] to describe acoustic streaming effects on microparticles/droplets in microfluidics. For a laminar flow, the governing equations of the motion in three dimensions (i.e., the continuity and Navier-Stokes equations) can be described as:…”