Eur. Phys. J. E (2018) 41: 19
https://doi.org/10.1140/epje/i2018-11627-6

Regular Article

Brownian motion near an elastic cell membrane: A theoretical study

¹ Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
² Biofluid Simulation and Modeling, Fachbereich Physik, Universität Bayreuth, Universitätsstraße 30, 95440, Bayreuth, Germany

^* e-mail: ider@thphy.uni-duesseldorf.de
^** e-mail: stephan.gekle@uni-bayreuth.de

Received: 7 December 2017
Accepted: 18 January 2018
Published online: 8 February 2018

Abstract

Elastic confinements are an important component of many biological systems and dictate the transport properties of suspended particles under flow. In this paper, we review the Brownian motion of a particle moving in the vicinity of a living cell whose membrane is endowed with a resistance towards shear and bending. The analytical calculations proceed through the computation of the frequency-dependent mobility functions and the application of the fluctuation-dissipation theorem. Elastic interfaces endow the system with memory effects that lead to a long-lived anomalous subdiffusive regime of nearby particles. In the steady limit, the diffusional behavior approaches that near a no-slip hard wall. The analytical predictions are validated and supplemented with boundary-integral simulations.