Acoustophoretic particle focusing is a modern and very attractive method of removing a variety of objects from solutions in a microfluidic channel. The process is applicable to healthcare applications (e.g., malignant cell removal), academic research (e.g., nanoparticle separation), industrial applications (e.g., reclaiming of rare earths) and environmental applications (e.g., sequestration of suspended solids) to name but a few.

The use of acoustophoresis has been increasingly used in the last 10 years for the manipulation, separation or concentration of particulate matter in complex media due to its non-invasiveness, versatility, simple fabrication, easy operation, and convenient integration with other on-chip units[1]. This “label free” method has allowed the separation of micrometer biological cells from complex biofluids depending on specific sizes, densities and compressibilities. The use of high flow rates (up to L/h) in microfluidic devices makes acoustophoresis more convenient than other sorting methods.

In this blog article, FLOW-3D is used to closely examine the forces that act on the particles and their effects. To the best of our knowledge, this is the first explicit study of this phenomenon that focuses on the different force contributions.