Dual sequentially addressable dielectrophoretic array for high-throughput, scalable, multiplexed droplet sorting

Abstract

Droplet microfluidics is a powerful tool for a diverse range of biomedical and industrial applications such as single-cell biology, synthetic biology, digital PCR, biosafety monitoring, drug screening, and food, feed, and cosmetic industries. As an integral part of droplet microfluidics, on-chip multiplexed droplet sorting has recently gained enthusiasm, since it enables real-time sorting of single droplets containing cells with different phenotypes into multiple bins. However, conventional sorting methods are limited in throughput and scalability. Here, we present high-throughput, scalable, multiplexed droplet sorting by employing a pair of sequentially addressable dielectrophoretic arrays (SADAs) across a microchannel on a microfluidic chip. A SADA is an on-chip array of electrodes, each of which is sequentially activated and deactivated in synchronization to the position and speed of a flowing droplet of interest. The dual-SADA (dSADA) structure enables high-throughput deflection of droplets in multiple directions in a well-controlled manner. For proof-of-concept demonstration and characterization of the dSADA, we performed fluorescence-activated droplet sorting (FADS) with a 3-way dSADA at a high throughput of 2450 droplets/s. Furthermore, to show the scalability of the dSADA, we also performed FADS with a 5-way dSADA at a high throughput of 473 droplets/s.