Study of DNA Dynamics In Micro/Nanofluidic De-Wetting Free Surface Flows and Pulsatory Electric Fields

A hybrid micro/nanochannel fluidic device was recently developed in our laboratory to achieve dosage controlled delivery of DNA to single cell using electric pulse induced electrophoresis through the nanochannel, i.e. nanoelectroporation (NEP). The fabrication of circular nanochannel embedded between two microchannels is realized by a DNA combing and imprinting (DCI) technique where large DNA molecules are stretched across a microridge array to form DNA nanowires in a de-wetting process. A molecular imprinting process is then carried out to convert the DNA nanowires to naochannels and microridges to microchannels. In NEP, DNA electrophoresis dynamics in pulsatory electric fields determines the transport of DNA from one microchannel to the other microchannel through the connecting nanochannel. In this work, Brownian dynamics based finite element simulation and nanofluidic experiments are carried out to study both hydrodynamic and electrophoretic DNA dynamics in the aforementioned DNA combing and NEP processes. The detailed DNA dynamics obtained from the Brownian dynamics simulation can explain the experimentally observed DNA nanowire formation and DNA electrophoresis under electric pulses.