title: Velocity profiles in pores with undulating opening diameter and their importance for resistive-pulse experiments.
abstract: Pores with undulating opening diameters have emerged as an analytical tool enhancing the speed of resistive-pulse experiments, with a potential to simultaneously characterize size and mechanical properties of translocating objects. In this work, we present a detailed study of the characteristics of resistive-pulses of charged and uncharged polymer particles in pores with different aspect ratios and pore topography. Although no external pressure difference was applied, our experiments and modeling indicated the existence of local pressure drops, which modified axial and radial velocities of the solution. As a consequence of the complex velocity profiles, pores with undulating pore diameter and low-aspect ratio exhibited large dispersion of the translocation times. Distribution of the pulse amplitude, which is a measure of the object size, was not significantly affected by the pore topography. The importance of tuning pore geometry for the application in resistive-sensing and multipronged characterization of physical properties of translocating objects is discussed.
authors.affiliation: Department of Physics and Astronomy, University of California , Irvine, California 92697, United States.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Innes
authors.forename: Chin-Hsuan
authors.initials: CH
authors.lastname: Chen
authors.forename: Matthew
authors.initials: M
authors.lastname: Schiel
authors.forename: Matthew
authors.initials: M
authors.lastname: Pevarnik
authors.forename: Florian
authors.initials: F
authors.lastname: Haurais
authors.forename: Maria Eugenia
authors.initials: ME
authors.lastname: Toimil-Molares
authors.forename: Ivan
authors.initials: I
authors.lastname: Vlassiouk
authors.forename: Luke
authors.initials: L
authors.lastname: Theogarajan
authors.forename: Zuzanna S
authors.initials: ZS
authors.lastname: Siwy
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004586:Electrophoresis; D051379:Mice; D008962:Models, Theoretical; D058608:Nanopores; D009995:Osmosis; D010316:Particle Size; D055585:Physical Phenomena; D011108:Polymers / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry; D016062:Porosity
chemical_list: D011108:Polymers; D011137:Polystyrenes