Analyte Distribution at Channel Intersections of Electro-Fluid-Dynamic Devices

摘要

Mass conservation is the guiding principle for analyte distribution at channel intersections of microfluidic devices, where analyte migration is mainly driven by an applied electric field, and in electro-fluid-dynamic (EFD) devices, where multiple fields and pressures can be applied simultaneously on the same channel network. This paper introduces another type of conservation, the conservation of effective volumetric flow rate, at channel intersections when the conductivity of the solution in the intersecting channels is maintained constant. This conservation principle provides an additional criterion needed to describe analyte migration in channels connecting to a common intersection and to predict how analyte is distributed into individual channels in the channel network of EFD devices, when multiple voltages and pressures are applied. The theoretical bases of effective volumetric flow rate balance are discussed, and the potential use of this principle in conjunction with the principle of mass conservation to predict the migration behavior of analytes is demonstrated. Junctions of different geometry in EFD devices are used to demonstrate the validity of these equations, and the measured velocities and numbers of microbeads in each channel agree with the predicted values.