An Improved Escherichia Coli Bacterium Detection in Microchannel Based on Dielectrophoresis Impedance Measurements

In this study, a bacterial detection technique utilizing benefits of both positive and negative dielectrophoresis has been simulated with COMSOL Multiphysics. The two dimensional proposed model has six microelectrodes across microfluidic channel. Four of them were positioned on the upper side and the rest were positioned on the bottom side of the microchannel, which serve as a bacteria concentrator using negative dielectrophoresis and as a bacteria detector using positive dielectrophoresis, respectively. In this simulation, the target particle is Escherichia coli that was flowing into the microchannel and repelled under negative dielectrophoretic force exerted by the upper side microelectrodes, and were pushed toward the bottom side microelectrodes situated at the downstream. Finally, concentrated bacteria have been captured and detected by dielectrophoretic impedance measurement method. The numerical simulation proved that negative dielectrophoretic force could increase sensitivity with respect to the absence of the negative dielectrophoretic force and eventually, results represented that 80 percent of releasing E. coli bacteria trapped near bottom side microelectrodes.