Droplet Manipulation Using Acoustic Streaming Induced by a Vibrating Membrane

Hoang Van Phan, Tuncay Alan, Adrian Neild

Research output: Contribution to journalArticleResearchpeer-review

17 Citations (Scopus)


We present a simple method for on-demand manipulation of aqueous droplets in oil. With numerical simulations and experiments, we show that a vibrating membrane can produce acoustic streaming. By making use of this vortical flow, we manage to repulse the droplets away from the membrane edges. Then, by simply aligning the membrane at 45° to the flow, the droplets can be forced to follow the membrane's boundaries, thus steering them across streamlines and even between different oil types. We also characterize the repulsion and steering effect with various excitation voltages at different water and oil flow rates. The maximum steering frequency we have achieved is 165 Hz. The system is extremely robust and reliable: the same membrane can be reused after many days and with different oils and/or surfactants at the same operating frequency.

Original languageEnglish
Pages (from-to)5696-5703
Number of pages8
JournalAnalytical Chemistry
Issue number11
Publication statusPublished - 7 Jun 2016

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