Geometry and dynamics of lipid membranes: The Scriven--Love number

Autor: Sahu, Amaresh, Glisman, Alec, Tchoufag, Joël, Mandadapu, Kranthi K.
Rok vydání: 2019
Předmět:
Zdroj: Phys. Rev. E 101, 052401 (2020)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevE.101.052401
Popis: The equations governing lipid membrane dynamics in planar, spherical, and cylindrical geometries are presented here. Unperturbed and first-order perturbed equations are determined and non-dimensionalized. In membrane systems with a nonzero base flow, perturbed in-plane and out-of-plane quantities are found to vary over different length scales. A new dimensionless number, named the Scriven--Love number, and the well-known F\"oppl--von K\'arm\'an number result from a scaling analysis. The Scriven--Love number compares out-of-plane forces arising from the in-plane, intramembrane viscous stresses to the familiar elastic bending forces, while the F\"oppl--von K\'arm\'an number compares tension to bending forces. Both numbers are calculated in past experimental works, and span a wide range of values in various biological processes across different geometries. In situations with large Scriven--Love and F\"oppl--von K\'arm\'an numbers, the dynamical response of a perturbed membrane is dominated by out-of-plane viscous and surface tension forces---with bending forces playing a negligible role. Calculations of non-negligible Scriven--Love numbers in various biological processes and in vitro experiments show in-plane intramembrane viscous flows cannot generally be ignored when analyzing lipid membrane behavior.
Comment: 16 pages, 7 figures, 5 tables
Databáze: arXiv