Continuous Enrichment and Separation of Nanoparticles via Acoustic Streaming.

Enrichment and separation of Micro/Nano-scale specimens are fundamental requirements in biomedical researches. In this paper, we demonstrated a simple and efficient microfluidic chip for the continuous enrichment and separation of nanoscale polystyrene particles using the acoustic streaming induced by gigahertz(GHz) bulk acoustic waves(BAW). The bulk acoustic resonator released ultrahigh frequency (2GHz) acoustic waves into the fluid and triggered the acoustic streaming. The nanoparticles were continuous concentrated and segregated by the combination action of the viscosity force and the acoustic radiation force. The separation of 300 and 100 nm particles was achieved with the high purity (92.4%). These data contribute proof-in-principle that acoustic streaming is a label-free strategy that can be used to enrich and separate nanoscale specimens with high efficiency.