Real-time size modulation and synchronization of a microfluidic dropmaker with pulsed surface acoustic waves (SAW)

Schmid, L. and Franke, T. (2018) Real-time size modulation and synchronization of a microfluidic dropmaker with pulsed surface acoustic waves (SAW). Scientific Reports, 8, 4541. (doi: 10.1038/s41598-018-22529-w) (PMID:29540848) (PMCID:PMC5852020)

157387.pdf - Published Version
Available under License Creative Commons Attribution.



We show that a microfluidic flow focusing drop maker can be synchronized to a surface acoustic waves (SAW) triggered by an external electric signal. In this way droplet rate and volume can be controlled over a wide range of values in real time. Using SAW, the drop formation rate of a regularly operating water in oil drop maker without SAW can be increased by acoustically enforcing the drop pinch-off and thereby reducing the volume. Drop makers of square cross-sections (w = h = 30 µm, with width w and height h) that produce large drops of length l = 10 w can be triggered to produce drops as short as l ~ 2w, approaching the geometical limit l = w without changing the flow rates. Unlike devices that adjust drop size by changing the flow rates the acoustic dropmaker has very short transients allowing to adjust the size of every single drop. This allows us to produce custom made emulsions with a defined size distribution as demonstrated here not only for a monodisperse emulsion but also for binary emulsions with drops of alternating size. Moreover, we show that the robustness and monodispersity of our devices is enhanced compared to purely flow driven drop makers in the absence of acoustic synchronization.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Franke, Professor Thomas and Schmid, Mr Lothar
Authors: Schmid, L., and Franke, T.
College/School:College of Science and Engineering > School of Engineering
College of Science and Engineering > School of Engineering > Biomedical Engineering
Journal Name:Scientific Reports
Publisher:Nature Publishing Group
ISSN (Online):2045-2322
Copyright Holders:Copyright © 2018 The Authors
First Published:First published in Scientific Reports 8:4541
Publisher Policy:Reproduced under a Creative Commons License

University Staff: Request a correction | Enlighten Editors: Update this record

Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
690991Thin Film Platform Technologies for Conformable and Mechanically Flexible BiosensorsThomas FrankeEngineering and Physical Sciences Research Council (EPSRC)EP/P018882/1ENG - BIOMEDICAL ENGINEERING