(142ay) Hybrid Field Regulation of Long DNA Configurations and Dynamics in Flows

Polymer flows are important to a variety of chemical, polymer, and petroleum practices. Many existing non-Newtonian effects are still not well understood, partially due to the unclear individual macromolecule dynamics. The introduction of direct visualization and manipulation of single long DNA molecule provides a wealth of physical insights in complex flow study. However, the diversity and stochastical tumbling of macromolecules causes large fluctuations of their configurations when measuring individual molecule dynamics, which impedes its wide adoption in polymer flow research. Here we report a hybrid field microfluidics (HFM) approach to overcome these issues. In HFM, a desired electric bias is imposed in appropriate moments and locations to effectively regulate the concentration and molecular configurations of DNA molecules as well as their dynamics in flows. With lambda DNA as the model molecules, we systematically studied the trapping, the chain relaxation, the coil-stretch dynamics, and the accumulation of macromolecules under different flow conditions for both Newtonian and non-Newtonian fluids. Our observations are further compared to other pioneer work and further correlated with bulk phenomena to establish connections with macromolecular dynamics and interactions at microscopic level.