Sensitive and predictable separation of microfluidic droplets by size using in-line passive filter

Ruihua Ding; W Lloyd Ung; John A Heyman; David A Weitz

doi:10.1063/1.4976723

Sensitive and predictable separation of microfluidic droplets by size using in-line passive filter

Biomicrofluidics. 2017 Feb 21;11(1):014114. doi: 10.1063/1.4976723. eCollection 2017 Jan.

Authors

Ruihua Ding¹, W Lloyd Ung², John A Heyman, David A Weitz²

Affiliations

¹ Department of Chemistry and Chemical Biology, Harvard University , Cambridge, Massachusetts 02138, USA.
² John A. Paulson School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, USA.

Abstract

Active manipulation of droplets is crucial in droplet microfluidics. However, droplet polydispersity decreases the accuracy of active manipulation. We develop a microfluidic "droplet filter" that accurately separates droplets by size. The droplet filter has a sharp size cutoff and is capable of distinguishing droplets differing in volume by 20%. A simple model explains the behavior of the droplets as they pass through the filter. We show application of the filter in improving dielectric sorting efficiency.