A compact and tunable size-based flow fractionation microchip using negative dielectrophoresis (DEP) is presented in this paper. In the microchip, a sample containing a mixture of particles is hydrodynamically focused in a contraction sectionand then sorted by size after flowing over planar interdigitated electrodes. The electrodes and flow chamber were aligned at an angle of 45 to produce effective sorting. 1, 2.5 and 4.8 m polystyrene (PS) particles were successfully separated into three distinct streams in a short distance (1 mm) and collected in different outlet channels. The sorting was subjected to flow rates and electric potential. The experimental sorting efficiencies of 1, 2.5 and 4.8 m particles reached 97.2%, 79.6% and 99.8%, respectively. With the same device, lipid vesicle sorting was demonstrated. 86.9% of vesicles larger than 10 m were effectively extracted from the sample stream. Likewise, sorting of other biological particles can be achieved in the same fashion.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Mechanics of Materials
- Mechanical Engineering
- Electrical and Electronic Engineering