Binary particle separation in droplet microfluidics using acoustophoresis

Research output: Contribution to journalArticle


We show a method for separation of two particle species with different acoustic contrasts originally encapsulated in the same droplet in a continuous two-phase system. This was realized by using bulk acoustic standing waves in a 380 μm wide silicon-glass microfluidic channel. Polystyrene particles (positive acoustic contrast particles) and in-house synthesized polydimethylsiloxane (PDMS) particles (negative acoustic contrast particles) were encapsulated inside water-in-oil droplets either individually or in a mixture. At acoustic actuation of the system at the fundamental resonance frequency, the polystyrene particles were moved to the center of the droplet (pressure node), while the PDMS particles were moved to the sides of the droplet (pressure anti-nodes). The acoustic particle manipulation step was combined in series with a trifurcation droplet splitter, and as the original droplet passed through the splitter and was divided into three daughter droplets, the polystyrene particles were directed into the center daughter droplet, while the PDMS particles were directed into the two side daughter droplets. The presented method expands the droplet microfluidics tool-box and offers new possibilities to perform binary particle separation in droplet microfluidic systems.


External organisations
  • Uppsala University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Fluid Mechanics and Acoustics
Original languageEnglish
Article number063701
JournalApplied Physics Letters
Issue number6
Publication statusPublished - 2018 Feb 5
Publication categoryResearch

Related research output

Anna Fornell, 2018 Jun 5, Lund: Department of Biomedical Engineering, Lund university. 134 p.

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