Separation and enrichment of nano and sub-micrometer particles from body fluid is important in diagnostic, prognostic, and other biomedical and bioanalytical applications. Centrifugation based methods have been the most common approach to separate these components. However, excessive centrifugational forces can alter morphology and functionality of cell membranes, receptors, and other cellular components that are vital for the analysis. Further, centrifugation is time consuming, needs larger volumes of samples, and prone to large sample loss. Acoustic focusing of particles and cells has been used as a gentle, non-contact, and high throughput cell and particle separation technique. However, it is difficult to manipulate particles smaller than 1 µm via acoustic focusing. It has been shown that acoustic forces can be employed to relocate parallel laminar flow streams of two impedance mis-matched fluids. In this work, we present an alternative way of using acoustic forces to manipulate nano and submicron sized particles in continuous flow passion. We will demonstrate the separation of submicron-sized particles from micron-sized particles through the combination of acoustic focusing of particles and acoustic fluid relocation. The proof of the concept will be presented using binary mixtures of particles and biological cells. Finally, the separation and enrichment efficiency of binary mixtures of various particle sizes obtained via flow cytometry will be presented. Our initial analyses show that particle enrichment of 90% or above can easily be achieved by combining acoustic focusing of particles and acoustic fluid relocation.

Acoustophoresis and acoustic fluid relocation: New approach for sub-micron particle separation

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.