Numerical Simulation Study of the Motion of Single-Chain Polymers in Microchannels

The rapid progress in microfluidic technology for viscoelastic fluids offers great potential in biomedical applications and beyond. Exploring macromolecular motion and conformation in microchannels is vital for understanding viscoelastic fluids at a microscopic level and enhancing microfluidic manipulation precision. Using the dissipative particle dynamics (DPD) method, this study investigates the influence of flow parameters, molecular properties, and microchannel structures on macromolecular motion and conformation. Findings include the center of mass distribution of macromolecules in straight-channel Poiseuille flow shifting toward the channel center with increasing confinement. In lower confinement, macromolecules exhibit symmetric probabilities of being coiled or stretched, whereas higher confinement favors coiling. Tapering channels exhibit similar conformational changes to straight channels but with increased stretch length. T-shaped channels display an entropic trapping mechanism favoring shorter chains, while longer chains exhibit a “hairpin escape” phenomenon. This study enhances the understanding of macromolecular motion at a microscopic level and contributes to the advancement of efficient microfluidic technologies.