Surface Accumulating E. coli in Water Flow Using a Bypass Mini-Channel Based Device

The objective of this research is to design and optimize a bypass mini/micro-channel based surface accumulator of E. coli which could be easily integrated with an acoustic wave biosensor. A computational research has been carried out using the state of the art computational software, CFD-ACE with water as bacteria bearing fluid. E. coli bacteria have been modeled as random discrete particles tracked by solving the Lagrangian equations. The design challenges are to achieve high particle to water ratio in a bypass channel and accumulation of particles on a surface of the channel, high enough Reynolds number to avoid bacteria swimming, and various particle boundary conditions. The optimized designs have achieved accumulation concentration of more than an order of magnitude higher than the inlet concentration at a flow velocity much higher than the bacteria swimming speed under various particle-boundary interactions. A bypass channel has been used in this design to separate concentrated water-particle mixture and accumulate particles on a surface of the channel where the biosensor can be installed safely and precisely.