Tunable particle separation in a hybrid dielectrophoresis (DEP)- inertial microfluidic device

Particle separation is indispensable in many microfluidic systems and holds a broad range of biomedical applications. Inertial microfluidic devices that work solely on intrinsic hydrodynamic forces and inertial effects can offer label-free, high throughput and high efficiency separation performance. However, the working range of the current inertial microfluidic systems is obtained by tailoring the inertial lift forces and secondary flow drag through flow speed. Each channel design is normally effective for specific target particles, which inevitably lacks the flexibility for various particle mixtures. Redesigning the structure and dimension of microchannels for new sets of particle mixtures is often time-consuming and expensive. In this work, by introducing an external dielectrophoretic force field and coupling it with inertial forces, we proposed here an innovative hybrid DEP-inertial microfluidic platform for particle tunable separation. The working principle of the device was explained and its functionality was validated by experiments. In addition, the dimension of target particle mixture can be varied by adjusting the electrical voltage without redesigning the channel structure or dimensions. It is expected that the proposed DEP-inertial concept can work as a flexible platform for a wide range of biomedical applications.