Simulation of a microfluidic device employing dielectrophoresis for liquid biopsy.

This article details simulation based study of cell separation in a dielectrophoretic microfluidic device. The device consists of a narrow microchannel connected to a wide microchannel with several finite sized planar interdigitated transducer electrodes protruding into the narrow microchannel from one of its sidewalls. In the narrow microchannel, the circulating tumor cells are subjected to positive dielectrophoresis while the regular cells are subjected to negative dielectrophoresis to achieve separation and as all cells move in to the wide microchannel, the physical distance between the two types of cells increases thereby making their collection from the device easier. Equations describing motion, fluid field, electric field, and electric potential form the mathematical model and accounts for forces related to inertia, drag, and dielectrophoresis. Applied electric potential, electrode/gap length, and tumor cell diameter have a positive effect on the performance metrics while velocity of the medium and microchannel width have negative effect on the performance metrics. The model presented in this article is beneficial in realizing liquid biopsy with the desired performance metrics using the proposed microfluidic device.