Highly efficient in-droplet particle concentration and separation by twDEP and EWOD for digital microfluidics

Abstract

This paper describes highly efficient in-droplet particle concentrations/separations (over 92% efficiency), where target particles are concentrated/separated within a droplet by traveling wave dielectrophoresis (twDEP) and a subsequent EWOD (electrowetting-on-dielectric) actuation physically splits target-rich regions into individual droplets. This in-droplet method will provide a new functionality of separation/concentration for digital (droplet-based) microfluidics [1], thereby possibly eliminating the necessity of adopting the conventional continuous-flow-based separation methods.