title: Generation of mechanical force by grafted polyelectrolytes in an electric field: application to polyelectrolyte-based nano-devices.
abstract: We analyse theoretically and by means of molecular dynamics (MD) simulations the generation of mechanical force by a polyelectrolyte (PE) chain grafted to a plane. The PE is exposed to an external electric field that favours its adsorption on the plane. The free end of the chain is linked to a deformable target body. By varying the field, one can alter the length of the non-adsorbed part of the chain. This entails variation of the deformation of the target body and hence variation of the force arising in the body. Our theoretical predictions for the generated force are in very good agreement with the MD data. Using the theory developed for the generated force, we study the effectiveness of possible PE-based nano-vices, composed of two clenching planes connected by PEs and exposed to an external electric field. We exploit the Cundall-Strack solid friction model to describe the friction between a particle and the clenching planes. We compute the diffusion coefficient of a clenched particle and show that it drastically decreases even in weak applied fields. This demonstrates the efficacy of the PE-based nano-vices, which may be a possible alternative to the existing nanotube nano-tweezers and optical tweezers.This article is part of the themed issue 'Multiscale modelling at the physics-chemistry-biology interface'.
authors.affiliation: Department of Mathematics, University of Leicester, Leicester LE1 7RH, UK nb144@le.ac.uk.
authors.forename: N V
authors.identifier: http://orcid.org/0000-0002-7107-0693
authors.initials: NV
authors.lastname: Brilliantov
authors.affiliation: National Research University Higher School of Economics, Department of Applied Mathematics, Moscow, Russia.
authors.forename: Yu A
authors.initials: YA
authors.lastname: Budkov
authors.affiliation: Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Seidel
mesh_terms: D003198:Computer Simulation; D004574:Electromagnetic Fields; D017276:Friction / Q000528:radiation effects; D008956:Models, Chemical; D056004:Molecular Dynamics Simulation; D053758:Nanoparticles / Q000737:chemistry* / Q000528:radiation effects* / Q000648:ultrastructure; D000071228:Polyelectrolytes / Q000737:chemistry* / Q000528:radiation effects*; D013314:Stress, Mechanical
chemical_list: D000071228:Polyelectrolytes
keywords: diffusion; nano-mechanics; polyelectrolytes